TY - JOUR TI - The need for a tighter particulate-matter air-quality standard AU - Frey, H.C. AU - Adams, P.J. AU - Adgate, J.L. AU - Allen, G.A. AU - Balmes, J. AU - Boyle, K. AU - Chow, J.C. AU - Dockery, D.W. AU - Felton, H.D. AU - Gordon, T. AU - Harkema, J.R. AU - Kinney, P. AU - Kleinman, M.T. AU - McConnell, R. AU - Poirot, R.L. AU - Sarnat, J.A. AU - Sheppard, L. AU - Turpin, B. AU - Wyzga, R. T2 - New England Journal of Medicine DA - 2020/// PY - 2020/// DO - 10.1056/NEJMsb2011009 VL - 383 IS - 7 SP - 680-683 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85089417407&partnerID=MN8TOARS ER - TY - CONF TI - Effect of changes since 2017 on the quality, credibility, and integrity of scientific review of national ambient air quality standards AU - Frey, H.C. C2 - 2020/// C3 - Proceedings of the Air and Waste Management Association's Annual Conference and Exhibition, AWMA DA - 2020/// VL - 2020-June UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85104833715&partnerID=MN8TOARS ER - TY - CONF TI - Locomotive fuel use and emission rates: Effects of transients and train consists AU - Rastogi, N. AU - Frey, H.C. C2 - 2020/// C3 - Proceedings of the Air and Waste Management Association's Annual Conference and Exhibition, AWMA DA - 2020/// VL - 2020-June UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85104863944&partnerID=MN8TOARS ER - TY - CONF TI - Fourier transform rheology of asphalt binders AU - Gulzar, S. AU - Underwood, S. C2 - 2020/// C3 - Advances in Materials and Pavement Performance Prediction II - Contributions to the 2nd International Conference on Advances in Materials and Pavement Performance Prediction, AM3P 2020 DA - 2020/// SP - 427-431 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85117414974&partnerID=MN8TOARS ER - TY - JOUR TI - Harmonizing across environmental nanomaterial testing media for increased comparability of nanomaterial datasets AU - Geitner, N.K. AU - Ogilvie Hendren, C. AU - Cornelis, G. AU - Kaegi, R. AU - Lead, J.R. AU - Lowry, G.V. AU - Lynch, I. AU - Nowack, B. AU - Petersen, E. AU - Bernhardt, E. AU - Brown, S. AU - Chen, W. AU - De Garidel-Thoron, C. AU - Hanson, J. AU - Harper, S. AU - Jones, K. AU - Von Der Kammer, F. AU - Kennedy, A. AU - Kidd, J. AU - Matson, C. AU - Metcalfe, C.D. AU - Pedersen, J. AU - Peijnenburg, W.J.G.M. AU - Quik, J.T.K. AU - Rodrigues, S.M. AU - Rose, J. AU - Sayre, P. AU - Simonin, M. AU - Svendsen, C. AU - Tanguay, R. AU - Tefenkji, N. AU - Van Teunenbroek, T. AU - Thies, G. AU - Tian, Y. AU - Rice, J. AU - Turner, A. AU - Liu, J. AU - Unrine, J. AU - Vance, M. AU - White, J.C. AU - Wiesner, M.R. T2 - Environmental Science: Nano AB - The chemical composition and properties of environmental media determine nanomaterial (NM) transport, fate, biouptake, and organism response. DA - 2020/// PY - 2020/// DO - 10.1039/c9en00448c VL - 7 IS - 1 SP - 13-36 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85078433067&partnerID=MN8TOARS ER - TY - ER - TY - ER - TY - ER - TY - ER - TY - ER - TY - CONF TI - A Case Study for Investigating Elevated Hydrogen Sulfide within a Wastewater Treatment Plant AU - Hsia, P.S. AU - Long, H.C. AU - Knapp, T. AU - Liu, M. AU - Melitas, N. T2 - Water Environment Federation Odors and Air Pollutants Conference 2020 C2 - 2020/// C3 - Water Environment Federation Odors and Air Pollutants Conference 2020 CY - Cincinnati, OH DA - 2020/// PY - 2020/3/15/ ER - TY - JOUR TI - Rapid Characterization of Per- and Polyfluoroalkyl Substances (PFAS) by Ion Mobility Spectrometry–Mass Spectrometry (IMS-MS) AU - Dodds, James N. AU - Hopkins, Zachary R. AU - Knappe, Detlef R. U. AU - Baker, Erin S. T2 - Analytical Chemistry AB - Per- and polyfluoroalkyl substances (PFAS) are an ensemble of persistent organic pollutants of global interest because of their associations with adverse health outcomes. Currently, environmental PFAS pollution is prolific as a result of the widespread manufacturing of these compounds and their chemical persistence. In this work, we demonstrate the advantages of adding ion mobility spectrometry (IMS) separation to existing LC-MS workflows for PFAS analysis. Using a commercially available drift tube IMS-MS, we characterized PFAS species and isomeric content in both analytical standards and environmental water samples. Molecular trendlines based on intrinsic mass and structural relationships were also explored for individual PFAS subclasses (e.g. PFSA, PFCA, etc.). Results from rapid IMS-MS analyses provided a link between mass and collision cross sections (CCS) for specific PFAS families and are linked to compositional differences in molecular structure. In addition, CCS values provide additional confidence of annotating prioritized features in untargeted screening studies for potential environmental pollutants. Results from this study show that the IMS separation provides novel information to support traditional LC-MS PFAS analyses and will greatly benefit the evaluation of unknown pollutants in future environmental studies. DA - 2020/3/17/ PY - 2020/3/17/ DO - 10.1021/acs.analchem.9b05364 VL - 92 IS - 6 SP - 4427-4435 UR - https://doi.org/10.1021/acs.analchem.9b05364 ER - TY - JOUR TI - Open source energy system modeling using break-even costs to inform state-level policy: A North Carolina case study AU - Li, B. AU - Thomas, J. AU - Queiroz, A.R. AU - DeCarolis, J.F. T2 - arXiv DA - 2020/// PY - 2020/// UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85093377128&partnerID=MN8TOARS ER - TY - JOUR TI - Wind energy investments facing uncertainties in the Brazilian electricity spot market: A real options approach AU - Aquila, G. AU - Queiroz, A.R. AU - Balestrassi, P.P. AU - Rotella Junior, P. AU - Rocha, L.C.S. AU - Pamplona, E.O. AU - Nakamura, W.T. T2 - Sustainable Energy Technologies and Assessments AB - This study proposes a Real Options approach to investigate the economic feasibility of a wind power plant investment with the option of abandoning along the project life cycle. This novel approach considers uncertainties representation concerning electricity sales revenue in the spot market, and the uncertainty represented by the settlements of energy trading differences. Our results show that when considering these uncertainties, the abandonment option adds 30.3% to the value of the project, and the chance of not abandoning it until the end of the useful life is equal to 70.9%. DA - 2020/// PY - 2020/// DO - 10.1016/j.seta.2020.100876 VL - 42 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85093981217&partnerID=MN8TOARS ER - TY - JOUR TI - Real-Time Stochastic Optimization of Energy Storage Management Using Deep Learning-Based Forecasts for Residential PV Applications AU - Hafiz, F. AU - Awal, M.A. AU - De Queiroz, A.R. AU - Husain, I. T2 - IEEE Transactions on Industry Applications AB - A computationally proficient real-time energy management method with stochastic optimization is presented for a residential photovoltaic (PV)-storage hybrid system comprised of a solar PV generation and a battery energy storage (BES). Existing offline energy management approaches for day-ahead scheduling of BES suffer from energy loss in real time due to the stochastic nature of load and solar generation. On the other hand, typical online algorithms do not offer optimal solutions for minimizing electricity purchase costs to the owners. To overcome these limitations, we propose an integrated energy management framework consisting of an offline optimization model concurrent with a real-time rule-based controller. The optimization is performed in receding horizon with load and solar generation forecast profiles using deep learning-based long short term memory method in rolling horizon to reduce the daily electricity purchase costs. The optimization model is formulated as a multistage stochastic program where we use the stochastic dual dynamic programming algorithm in the receding horizon to update the optimal set point for BES dispatch at a fixed interval. To prevent loss of energy during optimal solution update intervals, we introduce a rule-based controller underneath the optimization layer in finer time resolution at the power electronics converter control level. The proposed framework is evaluated using a real-time controller-hardware-in-the-loop test platform in an OPAL-RT simulator. The proposed real-time method is effective in reducing the net electricity purchase cost compared to other existing energy management methods. DA - 2020/// PY - 2020/// DO - 10.1109/TIA.2020.2968534 VL - 56 IS - 3 SP - 2216-2226 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85084192067&partnerID=MN8TOARS ER - TY - JOUR TI - Modelling and design of wind-solar hybrid generation projects in long-term energy auctions: A multi-objective optimisation approach AU - Aquila, G. AU - Queiroz, A.R. AU - Lima, L.M.M. AU - Balestrassi, P.P. AU - Marangon Lima, J.W. AU - Pamplona, E.O. T2 - IET Renewable Power Generation AB - This study proposes an approach to help the bidding processes of hiring wind-photovoltaic farms in long-term energy auctions. The proposed approach aims to define an optimal solution to configure wind-photovoltaic farms based on mixture design of experiments and the Lp method, as well as an efficiency metric designed to achieve diversification and to identify the Pareto dominant optimal portfolio. The proposed method is simple and flexible for practical applications. Moreover, its associated goals of choosing the Pareto dominant optimal solutions are aligned with the goals of the electricity regulators responsible to manage the hiring process for a new generation. To validate the method, wind-solar photovoltaic generation configurations in three Brazilian cities are analysed and the results are compared with other methods previously proposed in the literature. The results show that the proposed method has more intuitive criteria for the investor and regulator, without reducing the quality of the information provided to decision making. DA - 2020/// PY - 2020/// DO - 10.1049/iet-rpg.2020.0185 VL - 14 IS - 14 SP - 2612-2619 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85094890582&partnerID=MN8TOARS ER - TY - JOUR TI - Evaluating economic feasibility and maximization of social welfare of photovoltaic projects developed for the Brazilian northeastern coast: An attribute agreement analysis AU - Oliveira, L.G. AU - Aquila, G. AU - Balestrassi, P.P. AU - Paiva, A.P. AU - Queiroz, A.R. AU - Oliveira Pamplona, E. AU - Camatta, U.P. T2 - Renewable and Sustainable Energy Reviews AB - Recently, renewable energy projects, such as photovoltaic systems, have become interesting generation alternatives thanks to the incentive strategies developed by several countries. For the user of photovoltaic microgeneration, there is interest in the financial return of the investment, which is most often financed by public banks with a limited budget. Therefore, it is necessary to analyze variables related both to the point of view of the investor in microgeneration and to the public banks that subsidize them. However, defining the configuration of photovoltaic systems that guarantees the economic feasibility for those who invest without excessively burdening the public resource is a complex task and requires the analysis of different experts. To fill this gap, this paper proposes an innovative approach for evaluating photovoltaic projects based on Attribute Agreement Analysis. Experts on photovoltaic systems with different profiles and experience were asked about 16 scenarios, planned according to a factorial design with four factors: installed power capacity, PV cell type, debt ratio, and loan interest rate. The results demonstrated that the proposed approach fulfills the objective of simultaneously assessing the impact of investments in photovoltaic systems, considering the investors' and public banks’ viewpoints. In the case analyzed, although the evaluations are performed in a judicious way (Wwithin> 0.85), there is a low agreement between the experts (Woverall < 0.70). In addition, an expert bias was observed regarding loan interest for economic feasibility (W = 0.61), as well as a controversial perception of the maximization of social welfare (W = 0.2361). The Net Present Value profile, determined by the installed power capacity of the system, was used with these results to discuss the current Brazilian renewable energy financing policy. The results supported that experts tend to overestimate the impact of the financing interest rate on financial returns. DA - 2020/// PY - 2020/// DO - 10.1016/j.rser.2020.109786 VL - 123 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85079879120&partnerID=MN8TOARS ER - TY - JOUR TI - Contribution for bidding of wind-photovoltaic on grid farms based on NBI-EFA-SNR method AU - Aquila, G. AU - Queiroz, A.R. AU - Rotela Junior, P. AU - Rocha, L.C.S. AU - Pamplona, E.D.O. AU - Balestrassi, P.P. T2 - Sustainable Energy Technologies and Assessments AB - Methods for supporting the bidding processes of hybrid wind-photovoltaic (W-PV) farms are scarce, especially when numerous goals are included in the optimization problem. Therefore, the primary objective of this study is to develop a novel model that can help bidding of W-PV farms considering a range of objectives that maximize the environmental and welfare benefits. This new approach contributes to energy planning for any type of hybrid farm through multi-objective programming, even in cases where the optimization of several correlated outputs is desired. Using the proposed approach the optimal system configuration can be obtained in these cases with low computational costs. A non-linear multi-objective optimization (NL-MO) is proposed to optimize the area occupied by the W-PV farm, minimum feasibility price, electricity production expected, and standard-deviation of the electricity produced. The model has been elaborated from non-linear optimization using the normal-boundary intersection (NBI) method, exploratory factor analysis (EFA), and Taguchi signal-to-noise ratio (SNR). The optimal values for the response variables are an area of 132.92 km2, minimum price of 182.95 R$/MWh, annual electricity production of 72.17 GWh, with a standard deviation of 1.74 GWh and the ideal share is 41% wind power and 59% PV power. DA - 2020/// PY - 2020/// DO - 10.1016/j.seta.2020.100754 VL - 40 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85086744711&partnerID=MN8TOARS ER - TY - JOUR TI - Investigation on self-healing of neat and polymer modified asphalt binders AU - Wang, C. AU - Xue, L. AU - Xie, W. AU - Cao, W. T2 - Archives of Civil and Mechanical Engineering DA - 2020/3/6/ PY - 2020/3/6/ DO - 10.1007/s43452-019-0006-8 VL - 20 IS - 2 J2 - Archiv.Civ.Mech.Eng LA - en OP - SN - 1644-9665 UR - http://dx.doi.org/10.1007/s43452-019-0006-8 DB - Crossref ER - TY - JOUR TI - Drone Delivery of an Automated External Defibrillator AU - Rosamond, Wayne D. AU - Johnson, Anna M. AU - Bogle, Brittany M. AU - Arnold, Evan AU - Cunningham, Christopher J. AU - Picinich, Michael AU - Williams, Billy M. AU - Zègre-Hemsey, Jessica K. T2 - New England Journal of Medicine AB - Drone Delivery of an Automated External Defibrillator Delivery of an AED by drone was compared with on-the-ground retrieval of a fixed-location AED for simulated out-of-hospital cardiac arrest in s... DA - 2020/9/17/ PY - 2020/9/17/ DO - 10.1056/NEJMc1915956 UR - https://doi.org/10.1056/NEJMc1915956 ER - TY - JOUR TI - Alkali-Activated Hybrid Concrete Based on Fly Ash and Its Application in the Production of High-Class Structural Blocks AU - Rojas-Duque, Oriana AU - Espinosa, Lina Marcela AU - Robayo-Salazar, Rafael A. AU - Gutiérrez, Ruby Mejía T2 - Crystals AB - This article reports the production and characterization of a hybrid concrete based on the alkaline activation of a fly ash (FA) of Colombian origin, which was added with 10% Portland cement (OPC) in order to promote the compressive strength development at room temperature. The alkali-activated hybrid cement FA/OPC 90/10 was classified as a low heat reaction cement (type LH), according to American Society of Testing Materials, ASTM C1157; the compressive strength was of 31.56 MPa and of 22.68 MPa (28 days) at the levels of paste and standard mortar, respectively, with an initial setting time of 93.3 min. From this binder, a hybrid concrete was produced and classified as a structural type, with a compressive strength of 23.16 MPa and a flexural modulus of rupture of 5.32 MPa, at 28 days of curing. The global warming potential index (GWP 100), based on life cycle analysis, was 35% lower than the reference concrete based on 100% OPC. Finally, its use was validated in the manufacture of a solid block-type construction element, which reached a compressive strength of 21.9 MPa at 28 days, exceeding by 40.6% the minimum strength value established by the Colombia Technical Standard, NTC 4026 (13 MPa) to be classified as high class structural blocks. DA - 2020/10/17/ PY - 2020/10/17/ DO - 10.3390/cryst10100946 VL - 10 IS - 10 SP - 946 UR - https://doi.org/10.3390/cryst10100946 ER - TY - JOUR TI - Parameter estimation of synchronous machines considering field voltage variation during the sudden short-circuit test AU - Faria, V.A.D. AU - Bernardes, J.V. AU - Bortoni, E.C. T2 - International Journal of Electrical Power & Energy Systems AB - This work examines the influence of field voltage variation during a sudden short-circuit test and its direct impact on the parameter identification of synchronous machines. The test standards establish that field voltage must be kept constant during the short-circuit test. However, due to the presence of impedances in the voltage supply, control of the excitation system along with many other factors, field voltage may vary during this test. This work proposes a method to recover the machine parameters even when high amplitude field voltage variations are presented during the sudden short-circuit test. In addition, an algorithm capable of defining maximum field voltage variations along with its correspondent duration in order to respect a certain parameter estimation error is proposed. Finally, the models developed in this paper are investigated using data from a 140 MVA synchronous machine. DA - 2020/1// PY - 2020/1// DO - 10.1016/j.ijepes.2019.105421 VL - 114 UR - http://dx.doi.org/10.1016/j.ijepes.2019.105421 KW - Optimization models KW - Field voltage variation KW - Parameter identification KW - Sudden three-phase short-circuit test KW - Synchronous machines ER - TY - CONF TI - Neglecting compatibility torsions in the design of concrete structures AU - Proestos, G.T. AU - Bentz, E.V. AU - Collins, M.P. C2 - 2020/// C3 - American Concrete Institute, ACI Special Publication DA - 2020/// VL - SP-344 SP - 30-48 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85110322225&partnerID=MN8TOARS ER - TY - JOUR TI - Supplementary material to "Application of Low-Cost Fine Particulate Mass Monitors to Convert Satellite Aerosol Optical Depth Measurements to Surface Concentrations in North America and Africa" AU - Malings, Carl AU - Westervelt, Daniel AU - Hauryliuk, Aliaksei AU - Presto, Albert A. AU - Grieshop, Andrew AU - Bittner, Ashley AU - Beekmann, Matthias AU - Subramanian, R. DA - 2020/3/3/ PY - 2020/3/3/ DO - 10.5194/amt-2020-67-supplement VL - 3 UR - https://doi.org/10.5194/amt-2020-67-supplement ER - TY - JOUR TI - Application of Low-Cost Fine Particulate Mass Monitors to Convert Satellite Aerosol Optical Depth Measurements to Surface Concentrations in North America and Africa AU - Malings, Carl AU - Westervelt, Daniel AU - Hauryliuk, Aliaksei AU - Presto, Albert A. AU - Grieshop, Andrew AU - Bittner, Ashley AU - Beekmann, Matthias AU - Subramanian, R. AB - Abstract. Low-cost particulate mass sensors provide opportunities to assess air quality at unprecedented spatial and temporal resolutions. Established traditional monitoring networks have limited spatial resolution and are frequently absent in less-developed countries (e.g. in sub-Saharan Africa). Satellites provide snapshots of regional air pollution, but require ground-truthing. Low-cost monitors can supplement and extend data coverage from these sources worldwide, providing a better overall air quality picture. We demonstrate such a multi-source data integration using two case studies. First, in Pittsburgh, Pennsylvania, both traditional monitoring and dense low-cost sensor networks are present, and are compared with satellite aerosol optical depth (AOD) data from NASA's MODIS system. We assess the performance of linear conversion factors for AOD to surface PM2.5 using both networks, and identify relative benefits provided by the denser low-cost sensor network. In particular, with 10 or more ground monitors in the city, there is a two-fold reduction in worst-case surface PM2.5 estimation mean absolute error compared to using only a single ground monitor. Second, in Rwanda, Malawi, and the Democratic Republic of the Congo, traditional ground-based monitoring is lacking and must be substituted with low-cost sensor data. Here, we assess the ability of regional-scale satellite retrievals and local-scale low-cost sensor measurements to complement each other. In Rwanda, we find that combining local ground monitoring information with satellite data provides a 40 % improvement (in terms of surface PM2.5 estimation accuracy) with respect to using ground monitoring data alone. Overall, we find that combining ground-based low-cost sensor and satellite data can improve and expand spatio-temporal air quality data coverage in both well-monitored and data-sparse regions. DA - 2020/3/3/ PY - 2020/3/3/ DO - 10.5194/amt-2020-67 VL - 3 UR - https://doi.org/10.5194/amt-2020-67 ER - TY - JOUR TI - Sorption of Polyfluoroalkyl Surfactants on Surface Soils: Effect of Molecular Structures, Soil Properties, and Solution Chemistry AU - Mejia-Avendaño, S. AU - Zhi, Y. AU - Yan, B. AU - Liu, J. T2 - Environmental Science and Technology AB - Zwitterionic, cationic, and anionic per- and polyfluoroalkyl substances (PFASs) are identified in aqueous film-forming foam (AFFF) concentrates and AFFF-impacted sites. However, the mobility potential of zwitterionic and cationic PFASs is poorly understood, preventing reliable site assessment. The study aimed to elucidate the mobility behaviors of PFASs of various charge states in saturated soil–water systems and assess critical influencing factors. Five anionic, three zwitterionic, and one cationic PFASs were investigated in five soils through batch sorption experiments. Pairwise comparison revealed that the quaternary ammonium group imparted a strong affinity of cationic perfluorooctaneamide ammonium compound (PFOAAmS) for soils. The influence of the quaternary ammonium group is mitigated in polyfluoroalkyl betaines, yet perfluorooctane sulfonamidoalkyl betaine (PFOSB) showed strong sorption in selected soils. Two soil bulk properties showed some correlations with the soil–water distribution coefficient (Kd). A positive correlation with the fraction of soil organic carbon was found only for anionic PFASs, whereas cation exchange capacity had an approximate positive correlation with Kd only for PFOAAmS. Water chemistry (Ca2+ and pH) influences the sorption of nonanionic PFASs in very distinct fashions or even in opposite trends to what was known for anionic PFASs. Sorption was insensitive to pH changes except for PFOSB; PFOSB underwent profound sorption reduction because its speciation occurs around neutral pH, while the two other betaines and PFOAAmS have pKa values that are outside of the environmentally relevant range. The lack of correlations suggests that the transport potential of PFASs is probably highly site-specific. It remains a challenge in deciphering PFAS sorption mechanisms and predicting how AFFF plumes migrate. DA - 2020/// PY - 2020/// DO - 10.1021/acs.est.9b04989 VL - 54 IS - 3 SP - 1513-1521 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85079020881&partnerID=MN8TOARS ER - TY - CONF TI - Does the inoculum source improve anaerobic digestion of marine microalgae Dunaliella viridis? AU - Lai, Y.-C. AU - Ducoste, J.J. AU - de los Reyes, F.L. T2 - 10th International Conference on Algal Biomass, Biofuels and Bioproducts C2 - 2020/6/15/ CY - Pittsburgh, PA (Conference postponed) DA - 2020/6/15/ PY - 2020/6/15/ ER - TY - CONF TI - Dynamic and functional modeling of carbon metabolism in photosynthetic microalgae AU - Wang, D. AU - Lai, Y.C. AU - Karam, A. AU - de los Reyes, F.L., III AU - Ducoste, J.J. T2 - 10th Algal Biomass Biofuels and Bioproducts Conference C2 - 2020/// CY - Pittsburgh, PA (Conference postponed) DA - 2020/// PY - 2020/6/15/ ER - TY - CONF TI - Evaluation of Fly Ash as a cement replacement to reduce sewer collection system infrastructure maintenance and enhance sustainability AU - Kusum, S. AU - Pour-Ghaz, M. AU - Ducoste, J. T2 - Water Resource Research Institute (WRRI) Annual Conference C2 - 2020/3/18/ CY - Raleigh, NC (Conference Cancelled) DA - 2020/3/18/ PY - 2020/3/18/ ER - TY - SOUND TI - Explaining the Formation of Elevated Temperatures in Municipal Solid Waste Landfills AU - Ducoste, J.J. DA - 2020/2/12/ PY - 2020/2/12/ ER - TY - SOUND TI - Successfully Obtaining Tenure and Promotion at an R1 University AU - Ducoste, J.J. DA - 2020/5/14/ PY - 2020/5/14/ ER - TY - SOUND TI - Changing the Tide of Post Tenure Review AU - Ducoste, J.J. DA - 2020/6/24/ PY - 2020/6/24/ ER - TY - SOUND TI - Improving Diversity in Environmental Engineering and Science AU - Ducoste, J.J DA - 2020/8/6/ PY - 2020/8/6/ ER - TY - CONF TI - Clearing the Haze from Grease Interceptor Design AU - Ducoste, J.J. T2 - Water Environment Association of Texas (WEAT) Capacity, Management, Operation & Maintenance (CMOM) Virtual Conference C2 - 2020/8/27/ CY - (Virtual) DA - 2020/8/27/ PY - 2020/8/27/ ER - TY - CONF TI - Potential for subway energy savings and emissions reductions based on inter-run variability in speed trajectories: A case study of Baltimore subway AU - Yuan, W. AU - Frey, H.C. C2 - 2020/// C3 - Proceedings of the Air and Waste Management Association's Annual Conference and Exhibition, AWMA DA - 2020/// VL - 2020-June UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85104829385&partnerID=MN8TOARS ER - TY - CONF TI - Application of transit bus emissions model to emission estimation: Case study for a wolfline transit bus line at North Carolina State University AU - Wei, T. AU - Frey, H.C. AU - Yuan, W. C2 - 2020/// C3 - Proceedings of the Air and Waste Management Association's Annual Conference and Exhibition, AWMA DA - 2020/// VL - 2020-June UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85104853939&partnerID=MN8TOARS ER - TY - CONF TI - Effects of Aging on Asphalt Mixture and Pavement Performance AU - Saleh, N.F. AU - Keshavarzi, B. AU - Rad, F.Yousefi AU - Mocelin, D. AU - Elwardany, M. AU - Castorena, C. AU - Underwood, B.S. AU - Kim, Y.R. T2 - Transportation Research Board (TRB) 99th Annual Meeting C2 - 2020/// CY - Washington, DC DA - 2020/// PY - 2020/1/12/ ER - TY - CONF TI - Refinement of Climate-, Depth-, and Time-Based Laboratory Aging Procedure for Asphalt Mixtures AU - Braswell, E. AU - Saleh, N.F. AU - Elwardany, M. AU - Rad, F.Yousefi AU - Castorena, C. AU - Underwood, B.S. AU - Kim, Y.R. T2 - Transportation Research Board (TRB) 99th Annual Meeting C2 - 2020/// CY - Washington, DC DA - 2020/// PY - 2020/1/12/ ER - TY - CONF TI - A Predictive Framework for Modeling Changes in Asphalt Mixture Moduli with Oxidative Aging AU - Saleh, N.F. AU - Mocelin, D. AU - Rad, F.Yousefi AU - Castorena, C. AU - Underwood, B.S. AU - Kim, Y.R. T2 - Transportation Research Board (TRB) 99th Annual Meeting C2 - 2020/// CY - Washington, DC DA - 2020/// PY - 2020/1/12/ ER - TY - CHAP TI - Modeling changes in asphalt mixture properties with RAP content AU - Saleh, N. F. AU - Mocelin, D. AU - Castorena, C. AU - Kim, Y.R. T2 - Advances in Materials and Pavement Performance Prediction II AB - This paper investigates whether an existing framework that predicts the changes of asphalt mixture properties as a result of changes in asphalt binder modulus caused by oxidative aging can be expanded to predict changes caused by the inclusion of recycled asphalt pavements (RAP). This study stipulates that mastercurves of mixtures of similar gradation and component material sources but with different RAP contents can coincide if shifted horizontally along the log frequency axis, such that the shift factor can be related to the change in binder modulus. Changes in mixture fatigue properties are also shown to be a result of changes in asphalt binder properties. Under the right conditions, this study shows that the properties of a mixture containing a certain RAP content and of a certain age level can be predicted from the short-term aged properties of a mixture containing no RAP, or vice-versa. PY - 2020/12/8/ DO - 10.1201/9781003027362-78 SP - 334-338 OP - PB - CRC Press SN - 9781003027362 UR - http://dx.doi.org/10.1201/9781003027362-78 DB - Crossref ER - TY - JOUR TI - Agent-Based Model of a Blockchain Enabled Peer-to-Peer Energy Market: Application for a Neighborhood Trial in Perth, Australia AU - Monroe, Jacob G. AU - Hansen, Paula AU - Sorell, Matthew AU - Berglund, Emily Zechman T2 - SMART CITIES AB - The transfer of market power in electric generation from utilities to end-users spurred by the diffusion of distributed energy resources necessitates a new system of settlement in the electricity business that can better manage generation assets at the grid-edge. A new concept in facilitating distributed generation is peer-to-peer energy trading, where households exchange excess power with neighbors at a price they set themselves. However, little is known about the effects of peer-to-peer energy trading on the sociotechnical dynamics of electric power systems. Further, given the novelty of the concept, there are knowledge gaps regarding the impact of alternative electricity market structures and individual decision strategies on neighborhood exchanges and market outcomes. This study develops an empirical agent-based modeling (ABM) framework to simulate peer-to-peer electricity trades in a decentralized residential energy market. The framework is applied for a case study in Perth, Western Australia, where a blockchain-enabled energy trading platform was trialed among 18 households, which acted as prosumers or consumers. The ABM is applied for a set of alternative electricity market structures. Results assess the impact of solar generation forecasting approaches, battery energy storage, and ratio of prosumers to consumers on the dynamics of peer-to-peer energy trading systems. Designing an efficient, equitable, and sustainable future energy system hinges on the recognition of trade-offs on and across, social, technological, economic, and environmental levels. Results demonstrate that the ABM can be applied to manage emerging uncertainties by facilitating the testing and development of management strategies. DA - 2020/9// PY - 2020/9// DO - 10.3390/smartcities3030053 VL - 3 IS - 3 SP - 1072-1099 SN - 2624-6511 KW - peer-to-peer energy trading KW - distributed generation KW - electricity markets KW - energy storage KW - sociotechnical systems KW - agent-based modeling KW - blockchain KW - distributed ledger technology KW - smart contracts ER - TY - JOUR TI - Use of Social Media to Seek and Provide Help in Hurricanes Florence and Michael AU - DiCarlo, Morgan Faye AU - Berglund, Emily Zechman T2 - SMART CITIES AB - During hazardous events, communities can use existing social media networks to share information in real time and initiate a local disaster response. This research conducted a web-based survey to explore two behaviors around the use of social media during hurricanes: seeking help and responding to help requests. Through the survey, we sampled 434 individuals across several counties affected by 2018 hurricanes Florence and Michael, which were both designated by the National Oceanic and Atmospheric Administration as billion-dollar weather disasters. The survey questions collected data about demographics, social media use habits, perceptions towards social media, hurricane damages, and actions taken during a hurricane to seek and provide help. The Theory of Planned Behavior (TPB) was used to conceptualize and frame parameters that affect intentions and behaviors regarding the use of social media during hurricanes to seek and provide help. Survey responses are analyzed using statistical regression to evaluate hypotheses about the influence of factors on seeking help and responding to help requests. Regression analyses indicate that attitude and perceived behavioral control predict intention to access social media during a hurricane, partially supporting the TPB. Intention and experiencing urgent damages predict help-seeking behaviors using social media. Posting frequency to social media under normal conditions and the number of help requests seen during the event predict help-responding behaviors. Linear regression equations governing intention and behavior were parameterized using survey results. The factors underlying social media behavior during hurricanes as identified in this research provide insight for understanding how smart information technologies, such as personal devices and social media networks, support community self-sufficiency and hazard resilience. DA - 2020/12// PY - 2020/12// DO - 10.3390/smartcities3040059 VL - 3 IS - 4 SP - 1187-1218 SN - 2624-6511 KW - hurricanes KW - social media KW - Theory of Planned Behavior KW - survey KW - path analysis KW - regression ER - TY - CONF TI - Turning Disaster into Knowledge: Geotechnical Aspects of the 2018 Mw 7.1 Anchorage Alaska Earthquake AU - Cabas, A. AU - Beyzaei, C. AU - Franke, K. AU - Koehler, R. AU - Pierce, I. AU - Stuedlein, A. AU - Yang, J. AU - Christie, S. T2 - ASCE GeoCongress 2020 AB - The moment magnitude (Mw) 7.1 Anchorage, Alaska, earthquake on November 30, 2018 is one of the largest earthquakes to strike near a major U.S. city since the 1994 Northridge earthquake. No fatalities were reported, but the earthquake caused widespread power outages, structural damage to residential buildings, damage to roadways and railways, and ground failures. This paper presents a summary of preliminary findings by the NSF-sponsored Geotechnical Extreme Events Reconnaissance (GEER) team. Damage was characterized using a combination of on-ground site mapping and aerial reconnaissance with state-of-art geomatics technology and photogrammetry. Recorded peak ground accelerations (PGA) at most stations range between 0.2 g and 0.3 g, with a few sites in the central and southeastern vicinities of Anchorage with PGA greater than 0.5 g. The duration of strong shaking from the M 7.1 event may not have been enough to initiate substantial movements on the majority of the historic landslides from the 1964 M 9.2 earthquake, including the slides at the Turnagain Heights and 4th Avenue. However, liquefaction appeared to have contributed to re-mobilization of the 1964 Potter Hill (Rabbit Creek) landslide. While the majority of the damage observed in Anchorage and surrounding communities appeared to be non-structural, the isolated cases of structural damage seemed to be caused by geotechnical issues, particularly settlement of the foundation and/or slope deformations. C2 - 2020/2/25/ C3 - ASCE Geotechnical Special Publication: Proceedings from ASCE GeoCongress CY - Minneapolis, MN DA - 2020/2/25/ PY - 2020/2/25/ DO - 10.1061/9780784482810.020 ER - TY - JOUR TI - The Occurrence of Escherichia coli in Groundwater of Bekasi City (Case Study: Jatiluhur, Sumur Batu, and Jatirangga Urban Villages) AU - Maysarah, S. AU - Putri, G. L. AU - Pratama, M. A. AU - Zulkarnain, F. AU - Willetts, J. AU - Foster, T. AU - Genter, F. AU - Harris, A. AU - Priadi, C. R. T2 - 2020 2ND INTERNATIONAL CONFERENCE ON ENVIRONMENT, RESOURCES AND ENERGY ENGINEERING AB - Abstract The self-supply of groundwater at the household level, and especially in densely populated areas, is vulnerable to fecal contamination. The aim of this study was to assess the level of fecal contamination in groundwater of three urban villages in Bekasi City that depend greatly on groundwater: Jatiluhur, Sumur Batu, and Jatirangga. Water samples were taken from 255 households with various types of water sources in the rainy season from February-March 2020. Escherichia coli ( E. coli ) concentration was quantified with Colilert-18 using IDEXX Quanti-Tray/2000 based on Most Probable Number (MPN) method. E. coli levels were beyond the WHO standard and found in 60% of the sources; 24% were above 100 MPN/100 mL. The presence of E. coli in groundwater indicated a requirement for further treatment prior to the point of consumption and an urgent need to replace the water supply infrastructure for improved water sources. DA - 2020/// PY - 2020/// DO - 10.1088/1755-1315/566/1/012008 VL - 566 SP - SN - 1755-1307 ER - TY - CONF TI - Per- and Polyfluoroalkyl Substances (PFAS) in Landfill Leachate and Municipal Wastewater AU - Barlaz, M.A. AU - Thelusmond, J.R. AU - Levis, J.W. AU - DeStafano, N. T2 - Global Waste Management Symposium C2 - 2020/// CY - Indian Wells, CA DA - 2020/// PY - 2020/2/23/ ER - TY - JOUR TI - Field Testing of Municipal Waste Combustor Ash for Heat Generation Potential AU - Van Brundt, M.E. AU - Barlaz, M.A. AU - Castaldi, M.J. AU - Green, R. AU - Lewis, T. AU - Dottellis, J. DA - 2020/// PY - 2020/// ER - TY - CONF TI - Development of methods to measure heat released from ash hydration and carbonation in landfills AU - Narode, A. AU - Pour-Ghaz, M. AU - Ducoste, J. AU - Barlaz, M.A. T2 - Global Waste Management Symposium C2 - 2020/// CY - Indian Wells, CA DA - 2020/// PY - 2020/2/23/ ER - TY - CONF TI - Evaluation of Alternate Inocula for biochemical Methane Potential Testing AU - Schupp, S.L. AU - Barlaz, M.A. AU - De La Cruz, F.B. T2 - Global Waste Management Symposium C2 - 2020/// CY - Indian Wells, CA DA - 2020/// PY - 2020/2/23/ ER - TY - CONF TI - The effect of temperature on methane generation from solid waste excavated from landfills experiencing elevated temperatures AU - Schupp, S.L. AU - De la Cruz, F.B. AU - Barlaz, M.A. T2 - Global Waste Management Symposium C2 - 2020/// CY - Indian Wells, CA DA - 2020/// PY - 2020/2/23/ ER - TY - CONF TI - A Finite Element Model Describes Heat Generation, Transport, and Accumulation in Elevated Temperature Landfills AU - Hao, Z. AU - Ducoste, J. AU - Barlaz, M.A. T2 - Global Waste Management Symposium C2 - 2020/// CY - Indian Wells, CA DA - 2020/// PY - 2020/2/23/ ER - TY - CONF TI - Experimental Measurement of Heat Production from Al Corrosion under Landfill-Relevant Conditions AU - Hao, Z. AU - Ducoste, J. AU - Barlaz, M.A. T2 - Global Waste Management Symposium C2 - 2020/// CY - Indian Wells, CA DA - 2020/// PY - 2020/2/23/ ER - TY - CONF TI - Comparative Study on the Nature and Characteristics of Dissolved Organic Matter in Leachate from Two Landfills AU - Cruz, F.B. AU - Nelson, J. AU - Barlaz, M.A. T2 - Global Waste Management Symposium C2 - 2020/// CY - Indian Wells, CA DA - 2020/// PY - 2020/2/23/ ER - TY - CONF TI - Multimodal Inversion for Shear Modulus and Thickness of Arteries AU - Roy, T. AU - Urban, M.W. AU - Greenleaf, J.F. AU - Guddati, M.N T2 - IEEE International Ultrasonics Symposium C2 - 2020/// DA - 2020/// PY - 2020/9/6/ UR - https://api.ltb.io/show/BHQIA ER - TY - CONF TI - Guided wave inversion for arterial stiffness AU - Roy, Tuhin AU - Urban, Matthew W. AU - Greenleaf, James AU - Guddati, Murthy T2 - 179th Meeting of the Acoustical Society of America AB - Shear Wave Elastography (SWE) has been used to estimate arterial stiffness, an important biomarker for early cardiovascular diseases. In arterial SWE, the carotid artery is excited with acoustic radiation force and the observed wave propagation characteristics are used to estimate the arterial stiffness. We present an efficient guided wave inversion procedure, where the elastic modulus of the arterial wall is estimated by matching wave dispersion from experiments and simulation. Central to the proposed approach is an efficient forward model that computes the dispersion relation for the incompressible, immersed cylindrical tube; the model achieves high efficiency by combining semi-analytical finite element methods, selective reduced integration, and perfectly matched discrete layers. We utilize this forward model in an optimization framework to develop a streamlined methodology to estimate the modulus of the arterial wall. In this talk, we present the formulation of the method as well as validation using phantom experiments on 10 rubber tubes (VytaFlex-10), followed by preliminary work on inverting for the viscoelastic modulus. C2 - 2020/10// C3 - The Journal of the Acoustical Society of America DA - 2020/10// PY - 2020/12/7/ DO - 10.1121/1.5146760 VL - 148 SP - 2450–2450 M1 - 4 PB - Acoustical Society of America (ASA) UR - http://dx.doi.org/10.1121/1.5146760 ER - TY - CONF TI - Reopening Research Labs AU - Barlaz, M.A. T2 - Environmental Engineering Program Leaders Annual Meeting, Association of Environmental Engineering And Science Professors C2 - 2020/// DA - 2020/// PY - 2020/6/23/ ER - TY - BLOG TI - COVID-19: Are we safe from our own trash? AU - Barlaz, M.A. AU - De Los Reyes, F.L., III T2 - The Hill DA - 2020/8// PY - 2020/8// UR - https://thehill.com/opinion/healthcare/510717-covid-19-are-we-safe-from-our-own-trash?rnd=1596662526 ER - TY - CONF TI - PFAS Research and Solid Waste Management AU - Barlaz, M.A. AU - DeSilva, V. AU - Staley, B. T2 - Solid waste Association of North America, SWANApalooza C2 - 2020/6/24/ DA - 2020/6/24/ PY - 2020/6/24/ ER - TY - SOUND TI - PFAS 101: Impacts on Solid Waste Management AU - Barlaz, M.A. AU - DeSilva, V. AU - Staley, B. DA - 2020/// PY - 2020/// M3 - webinar ER - TY - CONF TI - Effect of Food Waste Diversion on Leachate Quality AU - Cruz, F.B. AU - Barlaz, M.A. T2 - Global Waste Management Symposium C2 - 2020/// CY - Indian Wells, CA DA - 2020/// PY - 2020/2/24/ ER - TY - CONF TI - The Contribution of Abiotic Cellulose Hydrolysis to Heat Accumulation in Landfills AU - Charania, K.A. AU - Barlaz, M.A. T2 - Global Waste Management Symposium C2 - 2020/// CY - Indian Wells, CA DA - 2020/// PY - 2020/2/24/ ER - TY - JOUR TI - Comment on “Release of Volatile Per- and Polyfluoroalkyl Substances from Aqueous Film-Forming Foam” AU - Titaley, Ivan A. AU - Cruz, Florentino B. De AU - Field, Jennifer A. T2 - Environmental Science & Technology Letters AB - ADVERTISEMENT RETURN TO ISSUEPREVCorrespondenceNEXTComment on “Release of Volatile Per- and Polyfluoroalkyl Substances from Aqueous Film-Forming Foam”Ivan A. Titaley*Ivan A. TitaleyDepartment of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon 97331, United States*Email: [email protected]. Phone: (541) 737-9208. Fax: (541) 737-0497.More by Ivan A. Titaleyhttp://orcid.org/0000-0003-4683-1160, Florentino B. De la CruzFlorentino B. De la CruzDepartment of Civil, Construction, and Environmental Engineering, North Carolina State University, Campus Box 7908, Raleigh, North Carolina 27695-7908, United StatesMore by Florentino B. De la Cruzhttp://orcid.org/0000-0002-0936-3778, and Jennifer A. Field*Jennifer A. FieldDepartment of Environmental and Molecular Toxicology, Oregon State University, Corvallis, Oregon 97331, United States*Email: [email protected]. Phone: (541) 737-2265. Fax: (541) 737-0497.More by Jennifer A. Fieldhttp://orcid.org/0000-0002-9346-4693Cite this: Environ. Sci. Technol. Lett. 2020, 7, 11, 866–868Publication Date (Web):September 2, 2020Publication History Received30 July 2020Accepted25 August 2020Revised6 August 2020Published online2 September 2020Published inissue 10 November 2020https://doi.org/10.1021/acs.estlett.0c00591Copyright © 2020 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views1858Altmetric-Citations1LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (914 KB) Get e-AlertsSUBJECTS:Chromatography,Degradation,Desorption,Fragmentation,Mixtures Get e-Alerts DA - 2020/11/10/ PY - 2020/11/10/ DO - 10.1021/acs.estlett.0c00591 VL - 7 IS - 11 SP - 866-868 UR - https://doi.org/10.1021/acs.estlett.0c00591 ER - TY - JOUR TI - Evaluation of the Temperature Range for Biological Activity in Landfills Experiencing Elevated Temperatures AU - Schupp, Sierra AU - De la Cruz, Florentino B. AU - Cheng, Qiwen AU - Call, Douglas F. AU - Barlaz, Morton A. T2 - ACS ES&T Engineering AB - There have been reports of municipal solid waste landfills with waste and gas wellhead temperatures of at least 80–100 °C, which is in excess of temperatures reported at typical landfills. Landfills experiencing heat accumulation over a broad area present a number of challenges involving leachate and gas quality and quantity, and the associated collection infrastructure. The objectives of this research were to evaluate the impact of temperature on methanogenesis and fermentation in landfills, and to evaluate the extent to which microbial populations acclimate when perturbed to either lower or higher temperatures relative to their in situ temperature. Samples excavated from two landfills exhibiting elevated temperatures were utilized as inocula for small- and reactor-scale experiments. The optimum temperature for methane generation in the thermophilic range was 47.5–57.5 °C, with yields reduced by ∼37 and 75% at 62.5 and 67.5 °C, respectively. While microbial populations did not acclimate above 67.5 °C, methanogenic activity resumed when waste was cooled. 16S rRNA sequencing revealed that Methanothermobacter likely plays a key role in facilitating methane production in landfills operating in the thermophilic range and that microbial community diversity decreased at higher incubation temperatures. There was evidence that fermentation occurs up to 77.5 °C, well above the upper limit for methanogens measured in this study. Model simulations predict that fermentation reactions contribute a ∼3–10 °C rise in waste temperature. DA - 2020/10/1/ PY - 2020/10/1/ DO - 10.1021/acsestengg.0c00064 VL - 1 IS - 2 SP - 216-227 J2 - ACS EST Eng. LA - en OP - SN - 2690-0645 UR - http://dx.doi.org/10.1021/acsestengg.0c00064 DB - Crossref KW - methane KW - inhibition KW - methanogenesis KW - archaea KW - fermentation ER - TY - JOUR TI - Experimental Study for Crowdsourced Ride Quality Index Estimation Using Smartphones AU - Medina, Jose R. AU - Salim, Ramadan AU - Underwood, B. Shane AU - Kaloush, Kamil T2 - JOURNAL OF TRANSPORTATION ENGINEERING PART B-PAVEMENTS AB - The use of smartphones to collect roughness measurements or ride quality has become popular in recent years, owing to the potential for substantial cost savings in data collection. Hurdles to widespread adoption of these techniques include the quality, uncertainty, and variability of the measurements. The objective of this paper is to evaluate the multifactor effects of collecting ride quality measurements from smartphones and how crowdsourcing using measurements from a population of different vehicles can be used to overcome or mitigate the effects of less resolute and more variable measurements. This investigation was carried out using two experiments. First, a full factorial design of experiment (DOE) was developed to evaluate the multifactor effects on ride quality measurements using the average rectified slope (ARS). Second, a custom DOE with the objective of analyzing the ARS from a population of vehicles from different classifications was carried out. The results from the first experiment suggested that individual factors contribute to statistical differences in ARS measurements. However, the second experiment showed that when looking into a population of vehicles with randomly sampled factors, the ARS measurements converge, and the statistical analysis showed no significance. This approach can be successfully implemented using a crowdsourcing approach where the focus is to analyze a population of vehicles instead of individual measurements. DA - 2020/12// PY - 2020/12// DO - 10.1061/JPEODX.0000225 VL - 146 IS - 4 SP - SN - 2573-5438 KW - Accelerometer KW - International roughness index (IRI) KW - Smartphones KW - Pavement condition KW - Pavement management KW - Crowdsourcing ER - TY - JOUR TI - Comparison of Treatment Timing between Aggregate Base and Full-Depth Asphalt Roads AU - Wang, Yizhuang David AU - Jeong, Jaehoon AU - Kim, Youngsoo Richard T2 - JOURNAL OF TRANSPORTATION ENGINEERING PART B-PAVEMENTS AB - Aggregate base-course (ABC) pavements and full-depth asphalt (FDA) pavements are the two most commonly used types of asphalt pavements. During pavement design and pavement management, engineers need to know the expected performance of the two types of pavements. To this end, this paper compares the performance of ABC and FDA pavements in North Carolina. Pavement condition data for 34 ABC sections and 17 FDA pavement sections were obtained from the Pavement Management System database at the North Carolina Department of Transportation and used for analysis. An index parameter is developed that accounts for the effects of pavement structure, asphalt thickness, and traffic volume and is correlated to the appropriate time to apply maintenance and rehabilitation treatments. Life cycle cost analysis examples, with adjustments based on the developed treatment time prediction model results, also are presented. Although the prediction model is developed based on pavement conditions in North Carolina, the same method and philosophy can be applied in other states. DA - 2020/12// PY - 2020/12// DO - 10.1061/JPEODX.0000216 VL - 146 IS - 4 SP - SN - 2573-5438 UR - https://doi.org/10.1061/JPEODX.0000216 KW - Aggregate base KW - Full-depth asphalt pavement KW - Treatment timing KW - Maintenance and rehabilitation KW - Pavement management KW - Pavement preservation KW - Life cycle cost analysis (LCCA) ER - TY - JOUR TI - Chip Seal Construction Variability and Its Impact on Performance AU - Jeong, Jaehoon AU - Adams, Javon M. AU - Kim, Y. Richard T2 - JOURNAL OF TRANSPORTATION ENGINEERING PART B-PAVEMENTS AB - This paper presents findings obtained from field and laboratory tests that were designed to assess chip seal construction variability in comparison to the targeted design, and to investigate the impact of any variability on the performance of chip seal treatments. The research approach involved three double-seal pavements in North Carolina. Granite 78M and No. 14 aggregate and CRS-2L emulsion were used in the construction. Chip seal specimens were sampled from each of the three test sections, and the aggregate application rate (AAR) and emulsion application rate (EAR) were determined using ignition oven tests. Chip seal performance was evaluated in terms of aggregate loss and bleeding using a third-scale model mobile load simulator (MMLS3). In addition, the fresh emulsions used in the test sections and the residue were tested using a rotational viscometer and dynamic shear rheometer, respectively. The construction variability reflected in the AARs and EARs and the emulsion residue properties were used to describe the aggregate loss and bleeding performance as determined by the MMLS3. DA - 2020/12// PY - 2020/12// DO - 10.1061/JPEODX.0000218 VL - 146 IS - 4 SP - SN - 2573-5438 UR - https://doi.org/10.1061/JPEODX.0000218 KW - Chip seal KW - Construction variability KW - Application rate KW - Third-scale model mobile load KW - Simulator model mobile load simulator (MMLS3) KW - Aggregate loss KW - Bleeding KW - Multiple stress creep and recovery (MSCR) ER - TY - SOUND TI - Water Security under changing climate: Stressors, Opportunities and Challenges AU - Arumugam, S. DA - 2020/10// PY - 2020/10// ER - TY - SOUND TI - Climate and Water Management: Opportunities and Challenges” by the Government of India (Invited talk) AU - Arumugam, S. DA - 2020/10// PY - 2020/10// ER - TY - CONF TI - COREGS: An optimization framework to analyze water and power systems together under a changing climate AU - Ford, L.C. AU - Queiroz, A. AU - DeCarolis, J. AU - Arumugam, S. T2 - American Geophysical Union Fall Meeting C2 - 2020/12/15/ DA - 2020/12/15/ PY - 2020/12/1/ ER - TY - CONF TI - Understanding the food-energy-water nexus through hydroeconomic modeling under near-term climate change and regional development portfolios AU - Kumar, H. AU - Arumugam, S. AU - Zhu, T. T2 - American Geophysical Union Fall Meeting C2 - 2020/12/15/ DA - 2020/12/15/ PY - 2020/12/1/ ER - TY - CONF TI - The Urban Flooding Open Knowledge Network: Delivering Flood Information to AnyOne, AnyTime AnyWhere AU - Merwade, V. AU - Yeghiazarian, L. AU - Arumugam, S. AU - Cai, X. AU - Shepherd, A. AU - Johnson, M. AU - Riasi, M.S. T2 - American Geophysical Union Fall Meeting C2 - 2020/12/15/ DA - 2020/12/15/ PY - 2020/12/1/ ER - TY - CONF TI - America's Water: Multiscale Forecasting and Innovation in Infrastructure Design & Management Instruments is critical for Climate Adaptation AU - Lall, U. AU - Arumugam, S. AU - Cioffi, F. AU - Devineni, N. AU - Doss-Gollin, J. AU - Kwon, H. AU - Rajagopalan, B. T2 - American Geophysical Union Fall Meeting C2 - 2020/12/15/ DA - 2020/12/15/ PY - 2020/12/1/ ER - TY - CONF TI - A framework for ecological flow allocation in multiple reservoir operation AU - Chalise, D. AU - Arumugam, S. AU - Mahinthakumar, G. AU - Ranjithan, R.S. AU - Eaton, Mi AU - Vidal, A.Ruhi T2 - American Geophysical Union Fall Meeting C2 - 2020/12/15/ DA - 2020/12/15/ PY - 2020/12/1/ ER - TY - JOUR TI - Developing the hydrological dependency structure between streamgage and reservoir networks AU - Mukhopadhyay, Sudarshana AU - Sankarasubramanian, A. AU - Awasthi, Chandramauli T2 - Scientific Data AB - Abstract Reliable operation of physical infrastructures such as reservoirs, dikes, nuclear power plants positioned along a river network depends on monitoring riverine conditions and infrastructure interdependency with the river network, especially during hydrologic extremes. Developing this cascading interdependency between the riverine conditions and infrastructures for a large watershed is challenging, as conventional tools (e.g., watershed delineation) do not provide the relative topographic information on infrastructures along the river network. Here, we present a generic geo-processing tool that systematically combines three geospatial layers: topographic information from the National Hydrographic Dataset (NHD Plus V2), streamgages from the USGS National Water Information System, and reservoirs from the National Inventory of Dams, to develop the interdependency between reservoirs and streamgages along the river network for upper and lower Colorado River Basin (CRB) resulting in River and Infrastructure Connectivity Network (RICON) that shows the said interdependency as a concise edge list for the CRB. Another contribution of this study is an algorithm for developing the cascading interdependency between infrastructure and riverine networks to support their management and operation. DA - 2020/10/1/ PY - 2020/10/1/ DO - 10.1038/s41597-020-00660-6 VL - 7 IS - 1 SP - 319 SN - 2052-4463 UR - http://dx.doi.org/10.1038/s41597-020-00660-6 ER - TY - CHAP TI - Incentivar el aprendizaje significativo con el uso de tutores virtuales AU - Coronell, Garis AU - Calle, Marie AU - Goenaga, Boris T2 - Buenas prácticas de assessment en programas de ingeniería A2 - Diaz, Amparo Camacho A2 - Gonzalez Araujo, Luis Alberto PY - 2020/// PB - Asociacion Colobiana de Facultades de Ingenieria / Universidad del Norte SN - 9789586800877 ER - TY - JOUR TI - A performance‐based multi‐model combination approach to reduce uncertainty in seasonal temperature change projections AU - Das Bhowmik, Rajarshi AU - Sankarasubramanian, Arumugam T2 - International Journal of Climatology AB - Abstract Future changes in climate variable exhibit prominent impact on flood magnitudes, crop yields, and freshwater withdrawal. Researchers typically ignore the large degree of uncertainty translated from climate projections to the estimated climate change magnitudes while applying pre‐processing approaches on climate change projections. General Circulation Models (GCM) exhibit substantial uncertainty in projecting future changes in the seasonal temperature, which is evaluated by estimating the shift in either the mean or variance. Bias between the observed changes (1950–1999) and GCM simulated changes vary across models, climate regions, seasons, and under emission scenarios. The simplest approach to reduce model structural uncertainty, equal weighting of GCMs, does not consider superiority of one or multiple GCMs compared to the rest. The current study adopts a performance‐based model combination approach that has shown efficiency in streamflow and weather forecasting, and GCM precipitation simulation. The optimal model combination approach has been modified to combine multi‐model climate change information, while yielding the spatial correlation in climate change information within a geographic region. The optimal model combination approach, along with a simple bias‐correction, is applied on 10 GCMs over nine climate regions across the coterminous United States (CONUS). We found that the optimal combination exhibits lower RMSE values as compared to the equal combination. Correlations between the model combined projections under optimal combination and the observed changes are strong and positive (>0.5). Future (2000–49) model combined projections exhibit an increase in the mean seasonal temperature by 2°C for winter and by 1°C for summer over almost all climate regions. DA - 2020/10/20/ PY - 2020/10/20/ DO - 10.1002/joc.6870 VL - 41 IS - S1 J2 - Int J Climatol LA - en OP - SN - 0899-8418 1097-0088 UR - http://dx.doi.org/10.1002/joc.6870 DB - Crossref KW - climate change KW - equal weighting KW - GCM KW - genetic algorithm KW - model combination KW - seasonal temperature ER - TY - JOUR TI - Reimagining Ride Sharing: Efficient, Equitable, Sustainable Public Microtransit AU - Bardaka, E. AU - Hajibabai, L. AU - Singh, M.P. T2 - IEEE Internet Computing AB - This article approaches ride sharing from the perspectives of equity and sustainability. A lack of transportation access exacerbates the challenges faced by transportation-disadvantaged individuals and communities, reducing opportunities for employment and civic engagement. This article presents a vision for public microtransit geared toward addressing today's disparities in transportation access. Through a methodology focused on user requirements and values, a user experience promoting cooperation, and an equity-based optimal resource allocation, it shows how cooperative ride sharing can realize an efficient, equitable, and sustainable public microtransit system. DA - 2020/// PY - 2020/// DO - 10.1109/MIC.2020.3018038 VL - 24 IS - 5 SP - 38-44 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85096235730&partnerID=MN8TOARS KW - Automobiles KW - Internet KW - Sustainable development KW - Ethics KW - Employment KW - User experience ER - TY - JOUR TI - The Roles of Climate Forcing and Its Variability on Streamflow at Daily, Monthly, Annual, and Long‐Term Scales AU - Yao, Lili AU - Libera, Dominic A. AU - Kheimi, Marwan AU - Sankarasubramanian, A. AU - Wang, Dingbao T2 - Water Resources Research AB - Abstract The temporal variability of precipitation and potential evapotranspiration affects streamflow from daily to long‐term scales, but the relative roles of different climate variabilities on streamflow at daily, monthly, annual, and mean annual scales have not been systematically investigated in the literature. This paper developed a new daily water balance model, which provides a unified framework for water balance across timescales. The daily water balance model is driven by four climate forcing scenarios (observed daily climate and observed daily climate with its intra‐monthly, intra‐annual, and inter‐annual variability removed) and applied to 78 catchments. Daily streamflow from the water balance model is aggregated to coarser timescales. The relative roles of intra‐monthly, intra‐annual, and inter‐annual climate variability are evaluated by comparing the modeled streamflow forced with the climate forcings at two consecutive timescales. It is found that daily, monthly, and annual streamflow is primarily controlled by the climate variability at the same timescale. Intra‐monthly climate variability plays a small role in monthly and annual streamflow variability. Intra‐annual climate variability has significant effects on streamflow at all the timescales, and the relative roles of inter‐annual climate variability are also significant to the monthly and mean annual streamflow, which is often disregarded. The quantitative evaluation of the roles of climate variability reveals how climate controls streamflow across timescales. DA - 2020/7// PY - 2020/7// DO - 10.1029/2020WR027111 VL - 56 IS - 7 J2 - Water Resour. Res. LA - en OP - SN - 0043-1397 1944-7973 UR - http://dx.doi.org/10.1029/2020WR027111 DB - Crossref KW - streamflow KW - climate variability KW - intra-monthly KW - intra-annual KW - inter-annual KW - Budyko ER - TY - JOUR TI - Changing Seasonality of Annual Maximum Floods over the Conterminous US AU - Basu, B. AU - Bhowmik, R. D. AU - Sankarasubramanian, A. T2 - Earth and Space Science Open Archive ESSOAr; AB - Earth and Space Science Open Archive This preprint has been submitted to and is under consideration at Water Resources Research. ESSOAr is a venue for early communication or feedback before peer review. Data may be preliminary.Learn more about preprints preprintOpen AccessYou are viewing the latest version by default [v1]Changing Seasonality of Annual Maximum Floods over the Conterminous USAuthorsBidrohaBasuRajarshiDas BhowmikSankarasubramanianArumugamiDSee all authors Bidroha BasuUniversity College Dublinview email addressThe email was not providedcopy email addressRajarshi Das BhowmikIndian Institute of Scienceview email addressThe email was not providedcopy email addressSankarasubramanian ArumugamiDCorresponding Author• Submitting AuthorNorth Carolina State UniversityiDhttps://orcid.org/0000-0002-7668-1311view email addressThe email was not providedcopy email address DA - 2020/// PY - 2020/// DO - 10.1002/essoar.10504706.1 UR - https://doi.org/10.1002/essoar.10504706.1 ER - TY - JOUR TI - The Roles of Climate Variability on Runoff at Daily, Monthly, Annual, and Long-term Scales AU - Yao, Lili AU - Libera, Dominic AU - Kheimi, Marwan Mustafa A. AU - Arumugam, Sankarasubramanian AU - Wang, Dingbao AB - Climate variability, in terms of the climatic fluctuations in precipitation and potential evapotranspiration, impacts the variability of runoff at different timescales. This paper developed a new daily water balance model which unifies the probability distributed model and the SCS curve number method, and provides a unified framework for water balances across different timescales. The model uses a daily step but can be forced with climate inputs varying at different timescales. The model is applied to 82 MOPEX catchments, and the runoff at a coarser timescale is aggregated from the daily runoff. For runoff at each timescale, the relative role of each climate variability (daily, monthly, or inter-annual variability) is evaluated by comparing the modeled runoff forced with the climate variability at two consecutive timescales. It is found that the runoff variability at the daily, monthly, and annual scale is primarily controlled by the climate variability at the same timescale. The monthly climate variability significantly contributes to both the daily and inter-annual runoff variability. However, both daily and inter-annual climate variability play much smaller roles in monthly runoff variability. Besides monthly climate variability, mean annual runoff receives considerable contribution from the inter-annual climatic variability, which is often disregarded in previous studies. The quantitative evaluation of the roles of climate variability reveals how climate controls runoff across different timescales. DA - 2020/1/29/ PY - 2020/1/29/ DO - 10.1002/essoar.10501784.1 VL - 1 UR - https://doi.org/10.1002/essoar.10501784.1 ER - TY - JOUR TI - Willingness to pay for freight travel time savings: contrasting random utility versus random valuation AU - Goenaga, Boris AU - Cantillo, Victor T2 - Transportation DA - 2020/// PY - 2020/// VL - 47 IS - 2 SP - 705-736 ER - TY - JOUR TI - Exploring alternative solid waste management strategies for achieving policy goals AU - Jaunich, Megan K. AU - Levis, James W. AU - DeCarolis, Joseph F. AU - Barlaz, Morton A. AU - Ranjithan, S. Ranji T2 - Engineering Optimization AB - The authors previously analysed a real-world solid waste management (SWM) system using the solid waste optimization life-cycle framework (SWOLF) to identify optimal SWM strategies that meet modelled objectives (e.g. cost, environmental impacts, landfill diversion). While mathematically optimal strategies can support SWM decision making, they may not be readily implementable because of unmodelled objectives (e.g. practical limitations, social preferences, political and management considerations). A mathematical programming technique extending SWOLF is used to systematically identify, for several scenarios, different ‘optimal’ SWM strategies that are maximally different from each other in terms of waste flows, while meeting modelled objectives and constraints. The performance with respect to unmodelled issues was analysed to demonstrate the flexibility in potential strategies. Practitioner feedback highlighted implementation challenges due to existing practices; however, insights gained from this exercise led to more plausible and acceptable strategies by incrementally modifying the initial SWM alternatives generated. DA - 2020/6/19/ PY - 2020/6/19/ DO - 10.1080/0305215X.2020.1759578 VL - 6 SP - 1-14 J2 - Engineering Optimization LA - en OP - SN - 0305-215X 1029-0273 UR - http://dx.doi.org/10.1080/0305215X.2020.1759578 DB - Crossref KW - Modelling to generate alternatives (MGA) KW - solid waste management (SWM) KW - life-cycle assessment (LCA) KW - solid waste optimization life-cycle framework (SWOLF) KW - solid waste policy analysis ER - TY - JOUR TI - Enhancement of biogas yield during anaerobic digestion of Jatropha curcas seed by pretreatment and co-digestion with mango peels AU - Haq, A. AU - Khan, A. AU - Haji, K. AU - Khan, S. AU - Shah, A. A. AU - Hasan, F. AU - Ahmed, Safia AU - Reyes, F. L. AU - Badshah, M. T2 - BIOMASS CONVERSION AND BIOREFINERY DA - 2020/// PY - 2020/// DO - 10.1007/s13399-020-01064-7 VL - 10 UR - http://dx.doi.org/10.1007/s13399-020-01064-7 KW - Mono-digestion KW - Anaerobic digestion KW - Pretreatment KW - C/N ratio KW - Methane KW - Mango peels ER - TY - JOUR TI - Bending response of lap welded steel pipeline joints AU - Sarvanis, Gregory C. AU - Chatzopoulou, Giannoula AU - Fappas, Dimitris AU - Karamanos, Spyros A. AU - Keil, Brent D. AU - Lucier, Gregory AU - Gobler, Fritz AU - Mielke, Richard D. T2 - THIN-WALLED STRUCTURES AB - The paper presents a combined experimental and numerical investigation of the bending response of lap welded joints in pressurized steel water pipelines. It is motivated by the structural performance of large-diameter steel pipelines used for water transmission in seismic and geohazard areas, where the pipeline may be subjected to severe permanent ground-induced actions. A series of large-scale four-point bending experiments on lap welded joints has been performed, and rigorous finite element numerical models have been developed for conducting extensive numerical simulations. The numerical models account for the bell forming process and the corresponding residual stresses, as well as the presence of initial geometric imperfections on the pipeline wall. A very good comparison has been found between experimental results and numerical simulations in terms of both global response and local strains developed at the vicinity of the weld. The finite element models are also employed for elucidating some interesting features of lap welded joint behavior under severe bending deformation, towards determining the joint strength, its deformation capacity and the evolution of strain at different deformation stages. The experimental and numerical results indicate that lap welded joints, can sustain a significant level of bending deformation and strain, without loss of pressure containment, and can be used in geohazard areas, where severe permanent ground-induced strains on the pipeline wall are expected to develop. • Seven 24-inch-size internally-pressurized specimens were tested in bending. • All specimens sustained significant deformation without loss of containment. • Predicted values of force and strain are in excellent agreement with test data. • Resistance of buckled specimens to cyclic pressure and burst has been excellent. • Maximum bending moment of lap welded joints is about 80% of that of plain pipe. DA - 2020/12// PY - 2020/12// DO - 10.1016/j.tws.2020.107065 VL - 157 SP - SN - 1879-3223 KW - Lap welded joint KW - Seismic resistance KW - Water pipeline KW - Geohazards KW - Steel pipeline ER - TY - JOUR TI - A Bayesian Inference driven computational framework for seismic risk assessment using large-scale nonlinear finite element analyses AU - Tadinada, Sashi Kanth AU - Gupta, Abhinav T2 - PROGRESS IN NUCLEAR ENERGY AB - Nuclear engineers are increasingly relying on large-scale simulations particularly for seismic risk assessment. Experimentally validated simulation models are used to consider the effects of uncertainties and evaluate fragilities by conducting multiple nonlinear analyses. However, such an approach becomes computationally prohibitive and care is needed to achieve desired degree of accuracy with a reasonable amount of computational effort. In this paper, a statistical framework is presented to minimize the total computational effort needed in conducting large-scale simulations for seismic risk assessment. The salient features of the framework are: (i) use of Bayesian inference to allow consideration of data from diverse sources like experiments, field data, existing or simplified approaches, and data from large-scale simulations, and (ii) embedment of Bayesian methods within an iterative process to plan and allocate adequate computing resources such that the desired accuracy is achieved using minimum possible simulations. The applicability and efficiency of the proposed framework is illustrated using the example of a box-shaped reinforced concrete shear wall. DA - 2020/12// PY - 2020/12// DO - 10.1016/j.pnucene.2020.103556 VL - 130 SP - SN - 0149-1970 KW - Bayesian inference KW - Risk-assessment KW - Simulation based risk assessment ER - TY - JOUR TI - Leveraging Open-Source Tools for Collaborative Macro-energy System Modeling Efforts AU - DeCarolis, Joseph F. AU - Jaramillo, Paulina AU - Johnson, Jeremiah X. AU - McCollum, David L. AU - Trutnevyte, Evelina AU - Daniels, David C. AU - Akin-Olcum, Gokce AU - Bergerson, Joule AU - Cho, Soolyeon AU - Choi, Joon-Ho AU - Craig, Michael T. AU - Queiroz, Anderson R. AU - Eshraghi, Hadi AU - Galik, Christopher S. AU - Gutowski, Timothy G. AU - Haapala, Karl R. AU - Hodge, Bri-Mathias AU - Hoque, Simi AU - Jenkins, Jesse D. AU - Jenn, Alan AU - Johansson, Daniel J. A. AU - Kaufman, Noah AU - Kiviluoma, Juha AU - Lin, Zhenhong AU - MacLean, Heather L. AU - Masanet, Eric AU - Masnadi, Mohammad S. AU - McMillan, Colin A. AU - Nock, Destenie S. AU - Patankar, Neha AU - Patino-Echeverri, Dalia AU - Schively, Greg AU - Siddiqui, Sauleh AU - Smith, Amanda D. AU - Venkatesh, Aranya AU - Wagner, Gernot AU - Yeh, Sonia AU - Zhou, Yuyu T2 - JOULE AB - The authors are founding team members of a new effort to develop an Open Energy Outlook for the United States. The effort aims to apply best practices of policy-focused energy system modeling, ensure transparency, build a networked community, and work toward a common purpose: examining possible US energy system futures to inform energy and climate policy efforts. Individual author biographies can be found on the project website: https://openenergyoutlook.org/. The authors are founding team members of a new effort to develop an Open Energy Outlook for the United States. The effort aims to apply best practices of policy-focused energy system modeling, ensure transparency, build a networked community, and work toward a common purpose: examining possible US energy system futures to inform energy and climate policy efforts. Individual author biographies can be found on the project website: https://openenergyoutlook.org/. Many nations have committed to mitigating climate change by designing and implementing policy solutions that enable deep decarbonization of their energy systems. Due to global reliance on fossil fuels, appropriate action requires fundamental and coordinated changes in the way societies generate and use energy. Policy makers face the monumental challenge of crafting effective energy and climate policy in the face of a highly uncertain future. The stakes are high because energy infrastructure often involves large, up-front investments in long-lived assets. Macro-energy system models, which are distinguished from other energy models by their energetic, temporal, and spatial scales,1Levi P.J. Kurland S.D. Carbajales-Dale M. Weyant J.P. Brandt A.R. Benson S.M. Macro-Energy Systems: Toward a New Discipline.Joule. 2019; 3: 2282-2286Abstract Full Text Full Text PDF Scopus (29) Google Scholar provide a systematic way to examine future decarbonization pathways, evaluate technology choices, test the effects and consequences of proposed policies, and explore decisions under future uncertainty. Analyses using these models yield critical insights that inform energy and climate policymaking around the world and underpin influential reports, including the World Energy Outlook by the International Energy Agency,2International Energy AgencyWorld Energy Outlook 2019.https://www.iea.org/reports/world-energy-outlook-2019Date: 2019Google Scholar the Annual Energy Outlook by the US Energy Information Administration,3US Energy Information AdministrationAnnual Energy Outlook 2020.https://www.eia.gov/outlooks/aeo/Date: 2020Google Scholar the Special Report on Global Warming of 1.5°C by the Intergovernmental Panel on Climate Change,4Hoegh-Guldberg, O., Jacob, D., Bindi, M., Brown, S., Camilloni, I., Diedhiou, A., Djalante, R., Ebi, K., Engelbrecht, F., Guiot, J., and Hijioka, Y. (2018). Impacts of 1.5 C global warming on natural and human systems. Global warming of 1.5°C. An IPCC Special Report. https://www.ipcc.ch/sr15/.Google Scholar and many others. It is an ongoing challenge for macro-energy system modeling teams to meet the universal and unprecedented policy needs associated with climate change mitigation. We envision a paradigm shift in the process of conducting model-based analysis from single-institution modeling teams to distributed, collaborative teams, allowing access to a much wider array of disciplinary and domain expertise to inform a given analysis. While some European efforts are already moving in this direction, the potential for collaborative, model-based analysis has yet to be realized. Energy system models vary considerably in their scope and complexity, and the choice of model should always be based on the research questions driving the analysis.5DeCarolis J. Daly H. Dodds P. Keppo I. Li F. McDowall W. Pye S. Strachan N. Trutnevyte E. Usher W. Winning M. Formalizing best practice for energy system optimization modelling.Appl. Energy. 2017; 194: 184-198Crossref Scopus (159) Google Scholar Here, we focus attention on employing macro-energy system models that cover the whole energy system and are used to inform policy at scales ranging from national to global. In this broadest macro-scale context, the boundaries of the modeled systems present numerous challenges for modeling deep decarbonization pathways. First, many supply- and demand-side technologies at varying stages of development could help decarbonize energy systems. Many of these technologies are novel (e.g., direct air capture and hydrogen-based steel production), have rapidly changing costs (e.g., solar photovoltaics, lithium-ion batteries, and electrolyzers), or have location-specific attributes (e.g., heat pumps and wind farms). These qualities make the projection of technology cost and performance characteristics over the multi-decade timescale of deep decarbonization very challenging. Second, the many decision makers across the energy system, each with their own objectives and preferences, make it difficult to model technology uptake, behavioral change, and public acceptance. Third, there is a need for modeling with high spatiotemporal resolution and multiple years of weather data in order to properly represent high penetrations of renewables with energy storage and other options for flexibility, since the modeled spatial variation in resource availability and temporal variation in supply and demand can have a significant impact on results. Fourth, policy-relevant insights should account for key underlying uncertainties affecting the modeled energy system. Neglecting any of these four challenges can lead to oversimplified model representations of the energy system with misleading conclusions; yet, including them increases model complexity, data requirements, and computational burden. Resolving this tension, given available resources, is difficult. Addressing the technical challenges of modeling decarbonization pathways requires considerable coordination of effort and broad domain expertise. When the effort is centralized at a single institution, institutional and governance structures can limit its effectiveness. Energy system modeling efforts housed within a single research group can suffer from a limited breadth of expertise. At the other extreme, some of the oldest and most established energy system models have been produced by government agencies and intergovernmental organizations that have the scale to draw on deep internal expertise across the energy system, but model-based analyses produced by these organizations can be subject to political considerations that limit the range of technologies or policies they will consider. In addition, commercial modeling efforts often rely on proprietary models and data that are not available to the broader expert community or interested stakeholders and therefore result in outcomes that cannot be easily reproduced and scientifically verified. To help address these shortcomings, distributed modeling teams can utilize existing open-source models, datasets, and tools to conduct collaborative, model-based analysis. Open-source efforts in the macro-energy space have proliferated over the last decade, and the resultant models, tools, and datasets serve as an important foundation for distributed modeling efforts because they enable transparency, accessibility, and replicability among team members and with the broader modeling community. Distributed efforts focused on model-based analysis allow for the flexible arrangement of teams to conduct different macro-energy modeling exercises, with each team configured to meet project-specific research objectives. The flexible arrangement of teams, in turn, means that specific modeling efforts can include participants with different disciplinary backgrounds and domain expertise who contribute to the diversity of ideas that can be explored in the analysis. The collective consideration of those ideas better reflects the system being modeled. For example, participants with a background in public policy, public administration, or economics can assist with the formulation, execution, and interpretation of more realistic policy scenarios, informed by debates and discussions in their respective communities. Modeling teams with collectively broad expertise across a range of issues and disciplines permit a more comprehensive analysis of the technical, social, economic, and policy features of deep decarbonization pathways, which are difficult to encode in models. In fact, all team members need not write code—the purposeful inclusion of non-modelers can lead to new insights and approaches associated with the model-based analysis.6Trutnevyte E. Hirt F.L. Bauer N. Cherp A. Hawkes A. Edelenbosch O.Y. Pedde S. van Vuuren D.P. Societal transformations in models for energy and climate policy: The ambitious next step.One Earth. 2019; 1: 423-433Abstract Full Text Full Text PDF Scopus (52) Google Scholar Diverse teams participating across the full project life cycle—from the formulation of key research questions, to the decision on how to represent a particular concept quantitatively, and then to the interpretation of model results as policy-relevant insights—can more effectively capture and assimilate novel ideas compared to conventional system modeling approaches that seek feedback at the end of the project or at discrete points during the project life cycle. These insights and ideas can range widely and may include the identification and proper use of a new dataset, a new model feature that captures a system dynamic critical to the issue under analysis, or the use of more efficient algorithms or methods that improve computational performance. Modeling teams that lack the appropriate depth and breadth are less able to effectively search, select, and incorporate new ideas from the broader macro-energy idea space into the analysis. Model parsimony should also be a design objective in order to avoid needless complexity,5DeCarolis J. Daly H. Dodds P. Keppo I. Li F. McDowall W. Pye S. Strachan N. Trutnevyte E. Usher W. Winning M. Formalizing best practice for energy system optimization modelling.Appl. Energy. 2017; 194: 184-198Crossref Scopus (159) Google Scholar and thus, distributed modeling teams must judiciously filter new ideas for incorporation into the analysis. Furthermore, the expanding scope enabled by distributed teams must be balanced with limited time, funding, and computational resources. The European Union is already pioneering a distributed and collaborative approach under the €80 billion Horizon 2020 research and innovation program. Projects such as SET-NAV (https://www.set-nav.eu/), openENTRANCE (https://openentrance.eu/), SENTINEL (https://sentinel.energy/), Spine (http://www.spine-model.org/), and EMP-E (http://www.energymodellingplatform.eu/) involve large teams variously working to integrate different models into larger frameworks, solicit input from a wide array of stakeholders, and perform model-based analysis that informs European energy and climate policy. The European Union is uniquely positioned to lead such efforts, given its ambitious energy-climate policy portfolio, well-funded scientific research programs, and ambitions for pan-national integration. While many other nations and regions—including the US—cannot easily replicate the top-down European approach without a significant change in policy priorities, we nonetheless assert that it is possible for researchers to organize similar efforts from the bottom up by leveraging existing resources within the scientific community. While distributed efforts focused on model-based analysis present unique logistical challenges, they also provide the flexibility to organize teams that capture diverse domain expertise and disciplinary approaches. All of the necessary elements exist to coordinate distributed model-based analysis: open-source energy models, well-established software development tools, a wide range of collaborative communication tools, and an increasing number of publicly available datasets on which to build. First, the open energy modeling initiative (“openmod”), an active and vibrant community of energy modelers committed to open-source practices, has cataloged a large array of open-source models7Openmod InitiativeOpen Models.https://wiki.openmod-initiative.org/wiki/Open_ModelsDate: 2020Google Scholar and helped to promulgate best practice standards for model developers that include licensing, documentation, reproducibility, and user support.8DeCarolis J.F. Hunter K. Sreepathi S. The case for repeatable analysis with energy economy optimization models.Energy Econ. 2012; 34: 1845-1853Crossref Scopus (82) Google Scholar, 9Pfenninger S. Hirth L. Schlecht I. Schmid E. Wiese F. Brown T. Davis C. Gidden M. Heinrichs H. Heuberger C. Hilpert S. Opening the black box of energy modelling: Strategies and lessons learned.Energy Strategy Reviews. 2018; 19: 63-71Crossref Scopus (129) Google Scholar, 10Pfenninger S. DeCarolis J. Hirth L. Quoilin S. Staffell I. The importance of open data and software: Is energy research lagging behind?.Energy Policy. 2017; 101: 211-215Crossref Scopus (192) Google Scholar, 11Morrison R. Energy system modeling: Public transparency, scientific reproducibility, and open development.Energy Strategy Reviews. 2018; 20: 49-63Crossref Scopus (52) Google Scholar Second, many energy modelers are using modern software development tools, which enable distributed control of code and data, with changes archived in publicly accessible web repositories. Third, a variety of communication options, including traditional email, cloud-based collaboration platforms, and videoconferencing software, make it possible for distributed teams to collaborate on highly technical issues in near-real time and at low cost. These modes of communication have indeed become an increasingly familiar part of our lives given how the coronavirus disease (COVID-19) pandemic has disrupted normal meeting patterns. In addition, social media represents a particularly effective way to crowdsource new ideas and approaches from the broader stakeholder community. Fourth, the volume of available data to populate energy models has grown over time and can be used to better parameterize models. The challenge, however, is that modelers are not aware of all relevant datasets, particularly those curated outside of the energy modeling community, nor do they always understand the underlying assumptions and limitations. Diversity in expertise among the modeling team can help ensure the proper identification and use of such datasets. In the long run, by using open-source tools and drawing on the expertise of non-modelers who are typically disconnected from the modeling process, distributed modeling teams may counteract the “incumbency advantage” of “long-lived and dominant” energy models12Strachan N. Fais B. Daly H. Reinventing the energy modelling–policy interface.Nat. Energy. 2016; 1: 1-3Crossref Google Scholar by helping redefine the way energy models operate. We view this approach as a critical element in the reinvention of the modeling-policy interface.12Strachan N. Fais B. Daly H. Reinventing the energy modelling–policy interface.Nat. Energy. 2016; 1: 1-3Crossref Google Scholar As with any new approach, there will be attendant challenges. Macro-energy modeling efforts face the same funding and coordination challenges confronted by other large scientific endeavors. Funding challenges are more logistically difficult with teams spanning multiple institutions. There is no single solution: financial arrangements will necessarily be a product of the funding agency, team composition, and objectives of the analysis. While there may be circumstances where funding can be equitably distributed among all participants, there might be other times when one or two lead organization(s) take the bulk of the responsibility, with smaller support grants and in-kind contributions from other members of the distributed team. Furthermore, funding need not always be a requirement for participation: limited but strategic input from a broad constellation of team members delivered at the right time in the process can have a large, positive impact on the direction of the project. While the Stanford Energy Modeling Forum (https://emf.stanford.edu/) is focused on inter-model comparison, its long-term success demonstrates that participants are willing to contribute their time, often without financial compensation, in return for the opportunity to collaborate with others and produce new scholarly research. Another challenge is the incentive structure within academia. It takes significant upfront effort to establish a common language and align project goals among team members from different academic disciplines. In addition, receiving credit for work completed is an important aspect of scholarly work. Credit often takes the form of co-authorship on reports and journal articles, and it is important to track the contributions of team members to ensure their efforts are recognized in an appropriate way, commensurate with their own institutional and disciplinary incentive structures. Furthermore, academic institutions should formally recognize the effort required to develop the open-source models, tools, and datasets that underpin the model-based analysis. The CRediT taxonomy, used by this publisher (https://www.cell.com/pb/assets/raw/shared/guidelines/CRediT-taxonomy.pdf), provides an excellent way to track the various contributions to distributed macro-energy modeling efforts. New modeling efforts that leverage these emerging opportunities can fulfill a unique niche within the global energy modeling community. We have begun to see the benefits of such an approach in our own effort to develop an Open Energy Outlook for the US (https://openenergyoutlook.org/). In addition to using an open-source modeling platform to perform the analysis (https://temoacloud.com/), we have established an interdisciplinary and inter-sectoral team of experts who are working collaboratively on the project with a unified vision. Our international team involves a number of experts drawn from academia, non-profits, and government labs and includes both experienced macro-energy system modelers and domain experts. Funding is distributed across two institutions that have primary responsibility for the deliverables, while participants from the remaining 20+ institutions make in-kind contributions of their time to the effort. Our project has a fraction of the funding associated with the large European efforts referenced above, and thus relies heavily on our collective interest in the project objectives and the opportunity to collaboratively produce scholarly work. Because participants are already working in related areas, they are able to leverage ongoing research activities and resources for this project. Our current team is meant to be a starting point for this long-term effort. Just as open-source tools foster collaborative development, democratization of the team building process can ensure a greater diversity of perspectives and make the effort more adaptable to new challenges. To this end, we are currently working on a formal and open nomination process for team membership. In addition, we are building a broader network of contributors to the project, and have sought input through a variety of online outlets, including social media, virtual workshops, and mailing lists. While still in the early stages, the project has already benefited from the diverse perspectives of the participants. For example, the electricity experts have pushed for a novel approach to increase the model’s temporal resolution while maintaining computational tractability and also identified opportunities to leverage existing open-source tools (https://github.com/gschivley/PowerGenome) and datasets (https://github.com/catalyst-cooperative/pudl). Likewise, the building experts are pushing the project to consider building thermodynamics more explicitly in order to better represent building thermal performance. The value here is bidirectional: systems modelers gain more familiarity with tools and data within particular sectors, while domain experts gain a better understanding of how their expertise can influence long-term energy scenarios. If done well, such an approach allows us to rethink and redefine common modeling approaches, potentially leading to innovative methods that result in new insights that are rigorously grounded by careful consideration of how the energy system—and all its myriad connections and feedbacks—is modeled. We would like to thank the Alfred P. Sloan Foundation for supporting this work. We also thank the two anonymous reviewers whose detailed and insightful feedback significantly strengthened the manuscript. Leveraging Open-Source Tools for Collaborative Macro-energy System Modeling EffortsDeCarolis et al.JouleFebruary 17, 2021In Brief(Joule 4, 2523–2531; December 16, 2020) Full-Text PDF Open Access DA - 2020/12/16/ PY - 2020/12/16/ DO - 10.1016/j.joule.2020.11.002 VL - 4 IS - 12 SP - 2523-2526 SN - 2542-4351 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85097654384&partnerID=MN8TOARS ER - TY - JOUR TI - Does the potential safety risk affect whether particular construction hazards are recognized or not? AU - Albert, Alex AU - Pandit, Bhavana AU - Patil, Yashwardhan AU - Louis, Joseph T2 - JOURNAL OF SAFETY RESEARCH AB - Introduction: Evidence from the global construction industry suggests that an unacceptable number of safety hazards remain unrecognized in construction workplaces. Unfortunately, there isn’t a sufficient understanding of why particular safety hazards remain unrecognized. Such an understanding is important to address the issue of poor hazard recognition and develop remedial interventions. A recent exploratory effort provided anecdotal evidence that workers often fail to recognize safety hazards that are expected to impose relatively lower levels of safety risk. In other words, the research demonstrated that the underlying risk imposed by a safety hazard can affect whether a hazard will be recognized or not. Method: The presented research focused on empirically testing this preliminary finding. More specifically, the study tested the proposition that Construction workers are more likely to recognize safety hazards that impose higher levels of safety risk than those that impose relatively lower levels of safety risk. The research goals were accomplished through a number of steps. First, a set of 16 construction case images depicting a variety of construction operations that included a number of known safety hazards was presented to a panel of four construction safety experts. The experts were tasked with examining each of the known safety hazards and providing a rating of the relative safety risk that the individual hazards impose. Having obtained an estimate of the underlying safety risk, a hazard recognition activity was administered to 287 workers recruited from 57 construction workplaces in the United States. The hazard recognition activity involved the examination of a random sample of two construction case images that were previously examined by the expert panel and reporting relevant safety hazards. Results: The results of the study provided support for the proposition that workers are more likely to recognize hazards that impose relatively higher levels of safety risk. Practical Applications: The findings of the study can be leveraged to improve existing hazard recognition methods and develop more robust interventions to address the issue of poor hazard recognition levels. DA - 2020/12// PY - 2020/12// DO - 10.1016/j.jsr.2020.10.004 VL - 75 SP - 241-250 SN - 1879-1247 KW - Safety and health KW - Construction safety, Injury prevention KW - Hazard recognition KW - Hazard identification KW - Safety risk ER - TY - JOUR TI - Limitations of traditional tools for beyond design basis external hazard PRA AU - Vaishanav, Pragya AU - Gupta, Abhinav AU - Bodda, Saran Srikanth T2 - NUCLEAR ENGINEERING AND DESIGN AB - Probabilistic risk assessment (PRA) is being used increasingly by the nuclear industry for safety during normal operations as well as for the protection against external hazards. Computation of total risk in an external hazard PRA is dependent on hazard assessment, fragility assessment, and systems analysis. A systems analysis for propagation of component fragilities is conducted using event and fault trees. The event and fault trees for an actual power plant can be fairly large in size, which imposes computational challenges. Hence, certain assumptions are employed for computational efficiency. These assumptions typically represent the conditions imposed during the design basis (DB) scenario. The traditional PRA tools based on these assumptions are also widely applied to perform risk assessment in the context of beyond design basis (BDB) scenarios. However, some of these assumptions may not be valid for certain BDB scenarios. In addition, the probability of dependent failures also increases in BDB scenarios due to common cause failures (CCF) which usually results from design modifications, human errors, etc. In this manuscript, a simple and a relatively more complex illustrative examples are used to show the limitation of these assumptions in the numerical quantification of risk for the case of BDB conditions. Case studies with CCF events across multiple fault trees are also presented to illustrate the effect of these assumptions when traditional approach is used in BDB risk assessment. It is shown that the assumptions are valid for the case of DB conditions but may lead to excessively conservative risk estimates in the case of BDB conditions. A Bayesian network based top-down algorithm is proposed as an alternative tool for accurate numerical quantification of total risk in systems analysis. DA - 2020/12/15/ PY - 2020/12/15/ DO - 10.1016/j.nucengdes.2020.110899 VL - 370 SP - SN - 1872-759X KW - Probabilistic risk assessment KW - Beyond design basis accidents KW - Common cause failure KW - Bayesian network KW - Event tree KW - Fault tree KW - Logic tree KW - PRA ER - TY - JOUR TI - Application of time-temperature superposition principle to pull-off tensile strength of asphalt tack coats AU - Sudarsanan, Nithin AU - Fonte, Benjamin Robert AU - Kim, Youngsoo Richard T2 - CONSTRUCTION AND BUILDING MATERIALS AB - Flexible pavements are multilayered structures that are designed to withstand vehicular traffic and thermal loading. Tack coat provides the bonding between these multilayers, which is a critical mechanism to provide a pavement with the monolithic action of asphalt layers to resist traffic and thermal loading, thereby dictating the pavement’s service life. Asphalt binder bond strength (BBS) is an indicator that can be used to evaluate the interlayer bonding ability of tack coat and changes as a function of temperature and loading rate. The focus of this paper is to prove that the time-temperature superposition principle is applicable to the BBS of various tack coat materials. In order to achieve this goal, BBS and dynamic shear rheometer (DSR) tests were conducted on four different tack coats, CRS-2, CRS-1h, NTCRS-1hM, and Ultrafuse. The Pneumatic Adhesion Tensile Testing Instrument (PATTI) was used to determine the BBS at 13 different temperatures ranging from 5 °C to 53 °C. The BBS data showed that adhesive failures between the binder and pull stub of PATTI caused the drop of BBS below 5 °C to 15 °C for hard (CRS-1h) and Non-tracking (NTCRS-1hM, Ultrafuse) tack coat. In addition to the BBS test, DSR tests were performed on the emulsion residue to measure the time-temperature shift factors at the reference temperature of 20 °C. It was found that the time-temperature shift factors determined from the DSR tests could be successfully used to shift the BBS vs. stress rate curves to construct the mastercurve for all four tack coat materials at a residual application rate of 0.14 L/m2 (0.03 Gal/yd2) as long as the BBS test exhibited cohesive failure between the binder and pull-off stubs. A simple method based on the BBS values at two temperatures is proposed to predict the mastercurve for routine characterization of the BBS mastercurve. No definite trend in the BBS mastercurve emerged among the different tack coat application rates for the different tack coats. DA - 2020/11/30/ PY - 2020/11/30/ DO - 10.1016/j.conbuildmat.2020.120798 VL - 262 SP - SN - 1879-0526 KW - Pneumatic Adhesion Tensile Testing KW - Instrument (PATTI) KW - Binder bond strength KW - Shear strength KW - Debonding KW - Tack coat KW - Emulsion KW - Time-temperature superposition ER - TY - JOUR TI - Emerging lanthanum (III)-containing materials for phosphate removal from water: A review towards future developments AU - Zhi, Yue AU - Zhang, Chuhui AU - Hjorth, Rune AU - Baun, Anders AU - Duckworth, Owen W. AU - Call, Douglas F. AU - Knappe, Detlef R. U. AU - Jones, Jacob L. AU - Grieger, Khara T2 - ENVIRONMENT INTERNATIONAL AB - The last two decades have seen a rise in the development of lanthanum (III)-containing materials (LM) for controlling phosphate in the aquatic environment. >70 papers have been published on this topic in the peer-reviewed literature, but mechanisms of phosphate removal by LM as well as potential environmental impacts of LM remain unclear. In this review, we summarize peer-reviewed scientific articles on the development and use of 80 different types of LM in terms of prospective benefits, potential ecological impacts, and research needs. We find that the main benefits of LM for phosphate removal are their ability to strongly bind phosphate under diverse environmental conditions (e.g., over a wide pH range, in the presence of diverse aqueous constituents). The maximum phosphate uptake capacity of LM correlates primarily with the La content of LM, whereas reaction kinetics are influenced by LM formulation and ambient environmental conditions (e.g., pH, presence of co-existing ions, ligands, organic matter). Increased La solubilization can occur under some environmental conditions, including at moderately acidic pH values (i.e., < 4.5–5.6), highly saline conditions, and in the presence of organic matter. At the same time, dissolved La will likely undergo hydrolysis, bind to organic matter, and combine with phosphate to precipitate rhabdophane (LaPO4·H2O), all of which reduce the bioavailability of La in aquatic environments. Overall, LM use presents a low risk of adverse effects in water with pH > 7 and moderate-to-high bicarbonate alkalinity, although caution should be applied when considering LM use in aquatic systems with acidic pH values and low bicarbonate alkalinity. Moving forward, we recommend additional research dedicated to understanding La release from LM under diverse environmental conditions as well as long-term exposures on ecological organisms, particularly primary producers and benthic organisms. Further, site-specific monitoring could be useful for evaluating potential impacts of LM on both biotic and abiotic systems post-application. DA - 2020/12// PY - 2020/12// DO - 10.1016/j.envint.2020.106115 VL - 145 SP - SN - 1873-6750 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85090951095&partnerID=MN8TOARS KW - Lanthanum KW - Lanthanum-containing materials KW - Phosphate KW - Surface water restoration KW - Eutrophication control KW - Phosphorus inactivation ER - TY - JOUR TI - Assessing the impact of closely-spaced intersections on traffic operations and pollutant emissions on a corridor level (vol 54, pg 304, 2017) AU - Fernandes, P. AU - Coelho, M. G. AU - Rouphail, N. M. T2 - TRANSPORTATION RESEARCH PART D-TRANSPORT AND ENVIRONMENT DA - 2020/10// PY - 2020/10// DO - 10.1016/j.trd.2020.102557 VL - 87 SP - SN - 1361-9209 ER - TY - JOUR TI - Treating water containing elevated bromide and iodide levels with granular activated carbon and free chlorine: impacts on disinfection byproduct formation and calculated toxicity AU - Zhang, Chuhui AU - Maness, J. Clark AU - Cuthbertson, Amy A. AU - Kimura, Susana Y. AU - Liberatore, Hannah K. AU - Richardson, Susan D. AU - Stanford, Benjamin D. AU - Sun, Mei AU - Knappe, Detlef R. U. T2 - ENVIRONMENTAL SCIENCE-WATER RESEARCH & TECHNOLOGY AB - Granular activated carbon effectively controlled disinfection byproduct formation and calculated toxicity, especially at high influent bromide levels. DA - 2020/12/1/ PY - 2020/12/1/ DO - 10.1039/d0ew00523a VL - 6 IS - 12 SP - 3460-3475 SN - 2053-1419 UR - https://doi.org/10.1039/D0EW00523A ER - TY - JOUR TI - The effect of laboratory compaction method on the resilient behaviour and fabric of aggregate base course materials AU - Bozorgi, A. AU - Fried, A. AU - Montoya, B.M. AU - Castorena, C. T2 - Road Materials and Pavement Design AB - Aggregate base course (ABC) layer is a key structural component of most pavements. The compaction of ABC is a crucial procedure affecting its mechanical performance. There are two different methods commonly used in the lab to compact ABC specimens: impact and vibratory. Past studies have demonstrated that the compaction method can affect the resilient deformation behaviour of ABC. However, the reasons for these differences in terms of the constituent ABC particle properties and the resultant compacted aggregate fabric remains unclear. This study evaluates the influence of the laboratory compaction method on the resilient behaviour and fabric of two ABC materials with differing mineralogies. Resilient modulus tests performed on the specimens compacted with the two methods result in different behaviours. A series of subsequent laboratory tests were performed to explain the observed resilient behaviour by assessing changes in aggregate morphology and fabric. The study presented herein incorporates digital imaging analyses using a novel specimen preparation technique. The results demonstrate that impact compaction can degrade ABC materials that are susceptible to crushing. This, in turn, increases the resilient modulus of the ABC by increasing the number of contact points between particles. It is recommended that the compaction method used in the laboratory match the compaction processes in the field as best as possible to obtain the most representative resilient modulus test results. DA - 2020/// PY - 2020/// DO - 10.1080/14680629.2019.1580606 VL - 21 IS - 7 SP - 1955-1967 KW - aggregate base course KW - resilient modulus KW - compaction KW - fabric KW - digital image analysis KW - particle contacts ER - TY - JOUR TI - Hazard Recognition Patterns Demonstrated by Construction Workers AU - Uddin, S. M. Jamil AU - Albert, Alex AU - Alsharef, Abdullah AU - Pandit, Bhavana AU - Patil, Yashwardhan AU - Nnaji, Chukwuma T2 - INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH AB - Construction workers fail to recognize a large number of safety hazards. These unrecognized safety hazards can lead to unintended hazard exposure and tragic safety incidents. Unfortunately, traditional hazard recognition interventions (e.g., job hazard analyses and safety training) have been unable to tackle the industry-wide problem of poor hazard recognition levels. In fact, emerging evidence has demonstrated that traditional hazard recognition interventions have been designed without a proper understanding of the challenges workers experience during hazard recognition efforts. Interventions and industry-wide efforts designed based on a more thorough understanding of these challenges can yield substantial benefits—including superior hazard recognition levels and lower injury rates. Towards achieving this goal, the current investigation focused on identifying hazard categories that workers are more proficient in recognizing and others that they are less proficient in recognizing (i.e., hazard recognition patterns). For the purpose of the current study, hazards were classified on the basis of the energy source per Haddon’s energy release theory (e.g., gravity, motion, electrical, chemical, etc.). As part of the study, 287 workers representing 57 construction workplaces in the United States were engaged in a hazard recognition activity. Apart from confirming previous research findings that workers fail to recognize a disproportionate number of safety hazards, the results demonstrate that the workers are more proficient in recognizing certain hazard types. More specifically, the workers on average recognized roughly 47% of the safety hazards in the gravity, electrical, motion, and temperature hazard categories while only recognizing less than 10% of the hazards in the pressure, chemical, and radiation hazard categories. These findings can inform the development of more robust interventions and industry-wide initiatives to tackle the issue of poor hazard recognition levels in the construction industry. DA - 2020/11// PY - 2020/11// DO - 10.3390/ijerph17217788 VL - 17 IS - 21 SP - SN - 1660-4601 UR - http://dx.doi.org/10.3390/ijerph17217788 KW - construction safety KW - hazard recognition KW - occupational safety KW - worker safety KW - hazard recognition pattern KW - construction hazards KW - safety risks ER - TY - JOUR TI - Pavement performance predictions using performance-volumetric relationship and evaluation of construction variability: Example of MaineDOT shadow project for the development of performance-related specifications AU - Jeong, Jaehoon AU - Wang, Yizhuang David AU - Ghanbari, Amir AU - Nash, Casey AU - Nener-Plante, Derek AU - Underwood, Benjamin Shane AU - Kim, Y. Richard T2 - CONSTRUCTION AND BUILDING MATERIALS AB - This paper describes the process chain for a shadow project of the Federal Highway Administration’s Asphalt Mixture Performance-Related Specifications (PRS) by the MaineDOT. Eleven mixture samples were acquired from a field project selected by MaineDOT and were performance-tested for calibration (a ‘four corners’ procedure) and verification to develop the performance-volumetric relationship (PVR) for the selected mixture. The PVR function for the selected mixture worked reasonably well to predict pavement performance at the volumetric conditions that were not included in the PVR development and reflected reasonable trends with regard to various field densities. DA - 2020/12/10/ PY - 2020/12/10/ DO - 10.1016/j.conbuildmat.2020.120150 VL - 263 SP - SN - 1879-0526 KW - Construction variability KW - Asphalt pavement KW - Performance volumetric relationship (PVR) KW - Asphalt Mixture Performance Tester (AMPT) KW - FlexMAT (TM) KW - FlexPAVE (TM) ER - TY - JOUR TI - Suitability of fly ash and cement for fabrication of compressed stabilized earth blocks AU - Elahi, Tausif E. AU - Shahriar, Azmayeen Rafat AU - Islam, Mohammad Shariful AU - Mehzabin, Farzana AU - Mumtaz, Nashid T2 - CONSTRUCTION AND BUILDING MATERIALS AB - This study is aimed at utilizing industrial waste Fly ash (FA) in combination with cement for production of environment friendly and economically viable Compressed Stabilized Earth Blocks (CSEBs). CSEBs are prepared with four cement contents (4%, 6%, 8% and 10%) and four FA contents (0%, 10%, 20%, 30%) and its performance are assessed in terms of strength and durability. Strength was measured using unconfined compression test, and consolidated undrained (CU) triaxial test; and durability was assessed in terms of water absorption test, wet compressive strength test, and accumulated loss of mass (ALM). Unconfined compression test shows that with the increase of cement, strength of the blocks increases for a definite FA content, however, for a fixed amount of cement, strength increases with addition of certain amount of FA, which is defined as the optimum FA content beyond which strength begins to drop. For 4% and 6% cement, optimum FA content was found 10%, for 8% cement, 20% FA was found to be the optimum content, whereas for 10% cement the optimum FA content is 30%. Deformation characteristics of CSEBs with different cement-FA combinations are analyzed in terms of stress-strain response and modulus of elasticity. Addition of proper amount of FA is found to improve modulus of elasticity, peak and failure strain response for a definite cement content. Moreover, microstructural investigation is carried out to investigate the arrangement of soil matrix for different contents of stabilizers. Optimum content of cement-FA obtained from unconfined compressive strength provide wet-to-dry strength ratio >0.33 which is an indicator of better durability performance. CU triaxial test results show that at a confining stress of 200 kPa and 300 kPa, maximum stress ratio and secant modulus occurs at a mix composition of 8% cement and 20% fly ash, which was considered optimum from compressive strength test scheme. Finally, test results were compared with the specifications of various existing standards and it can be concluded that with addition of optimum amount of cement-FA, CSEBs with acceptable strength and durability response can be produced. DA - 2020/12/10/ PY - 2020/12/10/ DO - 10.1016/j.conbuildmat.2020.120935 VL - 263 SP - SN - 1879-0526 KW - Compressed stabilized earth blocks KW - Unconfined compressive strength KW - Cement KW - Fly ash KW - Dry density KW - Durability KW - Porosity KW - Stress-strain response ER - TY - JOUR TI - Application of LCA modelling in integrated waste management AU - Christensen, T. H. AU - Damgaard, A. AU - Levis, J. AU - Zhao, Y. AU - Bjorklund, A. AU - Arena, U. AU - Barlaz, M. A. AU - Starostina, V AU - Boldrin, A. AU - Astrup, T. F. AU - Bisinella, V T2 - WASTE MANAGEMENT AB - Life cycle assessment (LCA) has been used in waste management for the last two decades and hundreds of journal papers have been published. The use of LCA in waste management has provided a much-improved holistic view of waste management including waste flows and potential environmental impacts. Although much knowledge has been obtained from LCA studies, there is still a need to use LCA models in integrated waste management. This paper describes six areas where LCA is expected to play a role in waste management in the future: 1) understanding an existing waste management system; 2) improving existing waste management systems; 3) comparing alternative technologies/ technology performance; 4) technology development/prospective technologies; 5) policy development/strategic development; and 6) reporting. Illustrative examples are provided for each application area. DA - 2020/12// PY - 2020/12// DO - 10.1016/j.wasman.2020.08.034 VL - 118 SP - 313-322 SN - 1879-2456 KW - LCA KW - Waste management KW - Modelling ER - TY - JOUR TI - Emerging investigator series: bacterial opportunistic pathogen gene markers in municipal drinking water are associated with distribution system and household plumbing characteristics AU - Haig, Sarah-Jane AU - Kotlarz, Nadine AU - Kalikin, Linda M. AU - Chen, Thomas AU - Guikema, Seth AU - LiPuma, John J. AU - Raskin, Lutgarde T2 - ENVIRONMENTAL SCIENCE-WATER RESEARCH & TECHNOLOGY AB - Municipally-treated drinking water (DW) is a potential source of exposure to bacterial opportunistic pathogens (OPs), which can cause infection in susceptible individuals. DA - 2020/11/1/ PY - 2020/11/1/ DO - 10.1039/d0ew00723d VL - 6 IS - 11 SP - 3032-3043 SN - 2053-1419 ER - TY - JOUR TI - Laboratory testing and numerical modeling of geomembrane electrical leak detection surveys AU - Cen, W. J. AU - Du, X. H. AU - He, H. N. AU - Yan, J. AU - Rahman, M. S. T2 - GEOSYNTHETICS INTERNATIONAL AB - Laboratory tests were conducted to evaluate the influence of the positions of positive and negative electrodes on the electrical response of a leak in the geomembrane. A numerical evaluation was performed to model the laboratory conditions and to investigate the effect of dipole spacing, excitation voltage, and impoundment resistivity on the leak detection sensitivity. The results of laboratory tests show that leaks cannot be identified when the positive electrode is very close to the leak and the electrical response of a leak in the geomembrane is independent of the position of the negative electrode. The results from the 3D finite element model indicate that leak detection sensitivity improves nonlinearly as the dipole spacing increases, and it tends to be stable after the dipole spacing exceeds 5% of the length of the survey line. The results also indicate that there is an almost linear increase in the leak detection sensitivity with increasing excitation voltage. Substantial improvement was obtained in the leak detection sensitivity for a greater impoundment resistivity. The numerical results indicate that 90% of leaks in a geomembrane liner can be effectively detected and accurately located for the 3D finite element model of a geomembrane lined earth-rock dam. DA - 2020/10// PY - 2020/10// DO - 10.1680/jgein.20.00012 VL - 27 IS - 5 SP - 490-502 SN - 1751-7613 KW - Geosynthetics KW - geomembranes KW - electrical leak detection KW - laboratory test KW - numerical modeling ER - TY - JOUR TI - A real-time network-level traffic signal control methodology with partial connected vehicle information AU - Islam, S.M.A. Bin Al AU - Hajbabaie, Ali AU - Aziz, H.M. Abdul T2 - Transportation Research Part C: Emerging Technologies AB - This paper presents two algorithms to estimate traffic state in urban street networks with a mixed traffic stream of connected and unconnected vehicles and incorporates them in a real-time and distributed traffic signal control methodology. The first algorithm integrates connected vehicles (CV) and loop detector data to estimate the trajectory of unconnected vehicles based on car-following concepts. The second algorithm converts the temporal point vehicle detections to a spatial vehicle distribution on a link. The signal control methodology utilizes either algorithm to estimate traffic state on all network links at a time, optimizes the signal timing parameters over a prediction period constituting several time steps, implements the optimal decisions in the next time step, and continues this process until the end of the study period. We applied the methodology to a real-world case study network simulated in Vissim. The results show that both algorithms are effective under a wide range of CV market penetration rates in all tested demand patterns: at 0% market penetration rate, the proposed methodology reduced travel time by 2% to 10% and average delay by 7% to 20% compared to the existing signal timing parameters and traffic demand. At a 40% penetration rate, the proposed algorithms reduced travel time by 27% to 33% and average delay by 50% to 61% compared to the existing signal and demand pattern in the case study network. Similar trends were found for all other demand patterns tested in this study. DA - 2020/12// PY - 2020/12// DO - 10.1016/j.trc.2020.102830 VL - 121 SP - 102830 UR - http://dx.doi.org/10.1016/j.trc.2020.102830 KW - Traffic signal control KW - Traffic state estimation KW - Connected vehicles KW - Distributed optimization and coordination algorithm KW - Market penetration rate ER - TY - JOUR TI - Wildfire and prescribed burning impacts on air quality in the United States T2 - Journal of the Air & Waste Management Association DA - 2020/10/2/ PY - 2020/10/2/ DO - 10.1080/10962247.2020.1813217 VL - 70 IS - 10 SP - 961-970 UR - http://dx.doi.org/10.1080/10962247.2020.1813217 ER - TY - JOUR TI - GRAPS: Generalized Multi-Reservoir Analyses using probabilistic streamflow forecasts AU - Xuan, Yi AU - Ford, Lucas AU - Mahinthakumar, Kumar AU - De Souza Filho, Assis AU - Lall, Upmanu AU - Sankarasubramanian, A. T2 - Environmental Modelling & Software AB - A multi-reservoir simulation-optimization model GRAPS, Generalized Multi-Reservoir Analyses using Probabilistic Streamflow Forecasts, is developed in which reservoirs and users across the basin are represented using a node-link representation. Unlike existing reservoir modeling software, GRAPS can handle probabilistic streamflow forecasts represented as ensembles for performing multi-reservoir prognostic water allocation and evaluate the reliability of forecast-based allocation with observed streamflow. GRAPS is applied to four linked reservoirs in the Jaguaribe Metropolitan Hydro-System (JMH) in Ceará, North East Brazil. Results from the historical simulation and the zero-inflow policy over the JMH system demonstrate the model's capability to support monthly water allocation and reproduce the observed monthly releases and storages. Additional analyses using streamflow forecast ensembles illustrate GRAP's abilities in developing storage-reliability curves under inflow-forecast uncertainty. Our analyses show that GRAPS is versatile and can be applied for 1) short-term operating policy studies, 2) long-term basin-wide planning evaluations, and 3) climate-information based application studies. DA - 2020/11// PY - 2020/11// DO - 10.1016/j.envsoft.2020.104802 VL - 133 SP - 104802 J2 - Environmental Modelling & Software LA - en OP - SN - 1364-8152 UR - http://dx.doi.org/10.1016/j.envsoft.2020.104802 DB - Crossref KW - Reservoir modeling KW - Software development KW - Simulation KW - Optimization KW - Water resources management ER - TY - JOUR TI - Analysis of travel characteristics and access mode choice of elderly urban rail riders in Denver, Colorado AU - Liu, Chang AU - Bardaka, Eleni AU - Palakurthy, Ravikumar AU - Tung, Li-Wei T2 - TRAVEL BEHAVIOUR AND SOCIETY AB - This paper investigates the potential impacts of congestion pricing and reward policies on migrant and resident millennial car travelers’ morning commute mode shift responses in China. A stated-preference survey developed for this study was conducted in 2017 among millennial car travelers living or working in Beijing’s inner district, from which approximately 2000 responses were collected. Separate random parameters bivariate ordered probit models were estimated for migrant and resident millennial car travelers to capture the differences between their mode shift responses, unobserved heterogeneity, and correlation between their mode shift responses to congestion pricing and reward policies. Sociodemographic characteristics, travel behavior and needs, residential location accessibility to and by transit, attitudes towards travel and congestion pricing and reward policies were found to affect millennial car travelers’ mode shift responses. In addition, the impacts of the contributing factors on the mode shift responses were very different between the congestion pricing and reward policies and between the migrant and resident millennial car travelers. The findings from the model estimation and descriptive statistics suggest that the implementation of pricing and reward policies, along with other unique regional (e.g., rapid increase in residential property price) and institutional (e.g., household registration system) characteristics, may potentially bring new challenges to migrant car travelers that may add to their economic burden and reduce their quality of life, particularly under congestion pricing policies. This study also provided insights for the design of future congestion pricing and reward policies and complementary measures that could address the travel needs of all travelers. DA - 2020/// PY - 2020/// DO - 10.1016/j.tbs.2020.11.004 VL - 19 SP - 194–206 KW - Congestion pricing policy KW - Reward policy KW - Mode shift response KW - Millennials KW - Migrants ER - TY - JOUR TI - A Smart Water Grid for Micro-Trading Rainwater: Hydraulic Feasibility Analysis AU - Ramsey, Elizabeth AU - Pesantez, Jorge AU - Fasaee, Mohammad Ali Khaksar AU - DiCarlo, Morgan AU - Monroe, Jacob AU - Berglund, Emily Zechman T2 - Water AB - Water availability is increasingly stressed in cities across the world due to population growth, which increases demands, and climate change, which can decrease supply. Novel water markets and water supply paradigms are emerging to address water shortages in the urban environment. This research develops a new peer-to-peer non-potable water market that allows households to capture, use, sell, and buy rainwater within a network of water users. A peer-to-peer non-potable water market, as envisioned in this research, would be enabled by existing and emerging technologies. A dual reticulation system, which circulates non-potable water, serves as the backbone for the water trading network by receiving water from residential rainwater tanks and distributing water to households for irrigation purposes. Prosumer households produce rainwater by using cisterns to collect and store rainwater and household pumps to inject rainwater into the network at sufficiently high pressures. The smart water grid would be enabled through an array of information and communication technologies that provide capabilities for automated and real-time metering of water flow, control of infrastructure, and trading between households. The goal of this manuscript is to explore and test the hydraulic feasibility of a micro-trading system through an agent-based modeling approach. Prosumer households are represented as agents that store rainwater and pump rainwater into the network; consumer households are represented as agents that withdraw water from the network for irrigation demands. An all-pipe hydraulic model is constructed and loosely coupled with the agent-based model to simulate network hydraulics. A set of scenarios are analyzed to explore how micro-trading performs based on the level of irrigation demands that could realistically be met through decentralized trading; pressure and energy requirements at prosumer households; pressure and water quality in the pipe network. DA - 2020/11/2/ PY - 2020/11/2/ DO - 10.3390/w12113075 UR - https://doi.org/10.3390/w12113075 KW - rainwater harvesting KW - water trading KW - dual reticulation KW - decentralized water supply KW - water distribution system KW - agent-based modeling KW - urban water management KW - smart city ER - TY - JOUR TI - Preliminary study on transit-induced residential gentrification in Nagoya, Japan AU - Wang, Lisha AU - Jiang, Meilan AU - Miwa, Tomio AU - Bardaka, Eleni AU - Morikawa, Takayuki T2 - Asian Transport Studies AB - The transit-induced residential gentrification caused by two urban rail transit lines in Nagoya, Japan is investigated individually. The difference-in-differences model, a quasi-experimental model, is used to explore the possible causal relationship between rail investments and residential gentrification. Two rail transit lines, which consist of subway and elevated railways, began operation in the same year and during a period of economic downturn. Investigations reveal that these rail transit lines located in different areas have achieved their own geographic scales of influence. Furthermore, the results show that the rail transit line located at the center of Nagoya causes a significant change in the household income of nearby neighborhoods, while evidence of transit-induced residential gentrification is not found for the suburb of Nagoya. DA - 2020/// PY - 2020/// DO - 10.1016/j.eastsj.2020.100022 VL - 6 SP - 100022 UR - http://dx.doi.org/10.1016/j.eastsj.2020.100022 ER - TY - JOUR TI - A multivariate, stochastic, climate-based wave emulator for shoreline change modelling AU - Cagigal, Laura AU - Rueda, Ana AU - Anderson, Dylan AU - Ruggiero, Peter AU - Merrifield, Mark A. AU - Montano, Jennifer AU - Coco, Giovanni AU - Mendez, Fernando J. T2 - OCEAN MODELLING AB - Coastal hazards often result from the combination of different simultaneous oceanographic processes that occur at multiple spatial and temporal scales. To predict coastal flooding and erosion, it is necessary to accurately represent hydrodynamic conditions. For this reason, here we present a stochastic, climate based wave emulator that provides the hydrodynamic conditions needed for these predictions. The emulator can generate an infinitely long data series maintaining its statistical properties at different time scales, from intra-storm to inter-annual variability, and its link to large scale climate patterns. The proposed methodology relies on the use of weather types and an autoregressive logistic regression model forced with different variables to simulate daily scale chronology. Considering the dependencies of wave conditions on the different weather types, the intra-storm chronology is solved by means of shuffling and stretching historical wave sequences. To demonstrate the replicability of this emulator worldwide, we have applied the model to 3 different locations and found good agreement when compared to the historical data. Furthermore, to illustrate and explain the strengths and limitations of the emulator, we present a different application for each of the different locations. DA - 2020/10// PY - 2020/10// DO - 10.1016/j.ocemod.2020.101695 VL - 154 SP - SN - 1463-5011 KW - Weather types KW - Emulator KW - Chronology KW - Coastal hazards KW - Shoreline ER - TY - JOUR TI - Tensile strength of sands treated with microbially induced carbonate precipitation AU - Nafisi, Ashkan AU - Mocelin, Douglas AU - Montoya, Brina M. AU - Underwood, Shane T2 - CANADIAN GEOTECHNICAL JOURNAL AB - During large earthquake events where bending moments within soil cements are induced, the tensile strength of cemented soil may govern the deformational behavior of improved ground. Several studies have been conducted to assess the tensile strength of artificially cemented sands that use Portland cement or gypsum; however, the tensile strength of microbially induced carbonate precipitation (MICP)-treated sands with various particle sizes measured through direct tension tests has not been evaluated. MICP is a biomediated improvement technique that binds soil particles through carbonate precipitation. In this study, the tensile strength of nine specimens were measured by conducting direct tension tests. Three types of sand (coarse, medium, and fine) were cemented to reach a heavy level of cementation (e.g., shear wave velocity of ∼900 m/s or higher). The results show that the tensile strength varies between 210 and 710 kPa depending on sand type and mass of carbonate. Unconfined compressive strength (UCS) tests were performed for each sand type to assess the ratio between tensile strength and UCS in MICP-treated sands. Scanning electron microscopy (SEM) images and surface energy measurements were used to determine the predominant failure mode at particle contacts under tensile loading condition. DA - 2020/10// PY - 2020/10// DO - 10.1139/cgj-2019-0230 VL - 57 IS - 10 SP - 1611-1616 SN - 1208-6010 KW - bio-cementation KW - MICP KW - tensile strength KW - unconfined compressive strength (UCS) ER - TY - JOUR TI - Assessment of the breakthrough of micropollutants in full-scale granular activated carbon adsorbers by rapid small-scale column tests and a novel pilot-scale sampling approach AU - Merle, Tony AU - Knappe, Detlef R. U. AU - Pronk, Wouter AU - Vogler, Bernadette AU - Hollender, Juliane AU - Gunten, Urs T2 - ENVIRONMENTAL SCIENCE-WATER RESEARCH & TECHNOLOGY AB - This study aimed to compare three approaches for predicting the service life of full-scale GAC adsorbers for the removal of micropollutants. DA - 2020/10/1/ PY - 2020/10/1/ DO - 10.1039/d0ew00405g VL - 6 IS - 10 SP - 2742-2751 SN - 2053-1419 UR - https://doi.org/10.1039/D0EW00405G ER - TY - JOUR TI - Multihazard Hurricane Fragility Model for Wood Structure Homes Considering Hazard Parameters and Building Attributes Interaction AU - Massarra, Carol C. AU - Friedland, Carol J. AU - Marx, Brian D. AU - Dietrich, J. Casey T2 - FRONTIERS IN BUILT ENVIRONMENT AB - Predicting building damage as a function of hurricane hazards, building attributes, and the interaction between hazard and building attributes is a key to understanding how significant interaction reflect variation hazard intensity effect on damage based on building attribute levels. This paper develops multi-hazard hurricane fragility models for wood structure homes considering interaction between hazard and building attributes. Fragility models are developed for ordered categorical damage states (DS) and binary collapse/no collapse. Exterior physical damage and building attributes from rapid assessment in coastal Mississippi following Hurricane Katrina (2005), high-resolution numerical hindcast hazard intensities from the Simulating WAves Nearshore and ADvanced CIRCulation (SWAN+ADCIRC) models, and base flood elevation values are used as model input. Leave-one-out cross-validation (LOOCV) is used to evaluate model prediction accuracy. Eleven and forty-nine combinations of global damage response variables and main explanatory variables, respectively, were investigated and evaluated. Of these models, one DS and one collapse model met the rejection criteria. These models were refitted considering interaction terms. Maximum 3-second gust wind speed and maximum significant wave height were found to be factors that significantly affect damage. Interaction between maximum significant wave height and number of stories was the significant interaction term for the DS and collapse models. For every 0.3 m (0.98 ft) increase in maximum significant wave height, the estimated odds of being in a higher damage state rather than lower damage state for DS model were found to be 1.95 times greater for one-story buildings rather than two-story buildings. For every 0.3 m (0.98 ft) increase in maximum significant wave height, the estimated odds of collapse were found to be 2.23 times greater for one-story buildings rather than two-story buildings. Model prediction accuracy was 84% and 91% for DS and collapse models, respectively. This paper does not consider the full hazard intensity experienced in Hurricane Katrina; rather, it focuses on single-family homes in a defined study area subjected to wind, wave, and storm surge hazards. Thus, the findings of this paper are not applicable for events with hazards that exceed those experienced in the study area, from which the models were derived. DA - 2020/9/22/ PY - 2020/9/22/ DO - 10.3389/fbuil.2020.00147 VL - 6 SP - SN - 2297-3362 KW - hurricane KW - predictive fragility models KW - interaction KW - multi-hazard KW - wood framed structure ER - TY - JOUR TI - Effectiveness of saw dust ash and cement for fabrication of compressed stabilized earth blocks AU - Elahi, Tausif E. AU - Shahriar, Azmayeen Rafat AU - Alam, Md Kausar AU - Abedin, Md Zoynul T2 - CONSTRUCTION AND BUILDING MATERIALS AB - This study focuses on investigating the effectiveness of Saw Dust Ash (SDA) and cement for fabricating strong and durable Compressed Stabilized Earth Block (CSEB) using coarse-grained soil. CSEB is a viable alternative to traditional Fired Clay Brick (FCB) as warranted by reduced associated pollution and increased energy efficiency. Four different cement contents (4%, 6%, 8% and 10%) and different SDA contents (0–10%) are considered to discern optimum combination to fabricate satisfactory CSEB in terms of compressive strength, shear strength, deformation behavior and durability. For a particular cement content, addition of SDA increases the compressive strength gradually, reaches a maximum value which is identified as optimum content and thereafter begins to drop. Optimum amount of SDA was found 4% for 4% cement, 6% for 6–8% cement and 8% for 10% cement. Addition of cement-SDA is found to increase the compressive strength of the blocks by 21–147% compared to that of unstabilized earth blocks. Moreover, optimum combination of cement-SDA provides CSEBs with maximum density and minimum porosity. Inclusion of cement-SDA is found effective in increasing angle of internal friction, ϕ of the stabilized mix. With addition of optimum SDA (4–8%) with cement, mixtures were found to exhibit ϕ>58o. CSEBs with optimum amount of cement-SDA is found to provide maximum modulus of elasticity, peak strain and failure strain. Addition of 6–8% SDA with 6–10% cement is found durable in terms of water absorption (<15%), wet compressive strength (>700 kPa) and wet-to-dry strength ratio (>0.33). Based on all the parameters and obtained test results, it can be concluded that cement-SDA stabilized earth blocks can be efficiently considered as a suitable construction material. DA - 2020/10/30/ PY - 2020/10/30/ DO - 10.1016/j.conbuildmat.2020.120568 VL - 259 SP - SN - 1879-0526 KW - Compressed stabilized earth blocks KW - Compressive strength KW - Cement KW - Saw dust ash KW - Durability KW - Porosity KW - Deformation behavior KW - Angle of internal friction ER - TY - JOUR TI - Asymmetrical removal of sodium and chloride in flow-through capacitive deionization AU - Algurainy, Yazeed AU - Call, Douglas F. T2 - WATER RESEARCH AB - Capacitive deionization (CDI) is an electrochemical method of removing salt ions from brackish water. A common assumption in CDI is that monovalent ions (e.g., Na+, Cl−) are removed in a 1:1 symmetry on the electrodes. Validation of this assumption with techniques such as ion chromatography is not commonly performed, but is important to better understand how parasitic process, such as faradaic reactions, affect ion removals. In this study, we quantified the removals of Na+ and Cl− as a function of electrode orientation in flow-through CDI. When the cathode was positioned upstream, Na+ and Cl− removals approached a 1:1 symmetry, but when the anode was located upstream, we observed a significant drop in Na+, but not Cl−, removals. We attributed this drop to oxygen reduction reactions at the cathode that competed with Na+ adsorption. Oxidation of carbon in the upstream anode yielded H+ that enhanced the reduction of oxygen to H2O2 at the downstream cathode, which in turn diverted electrons from Na+ adsorption. In the absence of oxygen, Na+ removals increased in the upstream anode orientation and were comparable to Cl− removals, confirming that competition with oxygen reduction reactions was the primary reason for decreased Na+ removal. In the upstream cathode orientation, we show that H2O2 generated at the cathode can be oxidized at the downstream anode, possibly enhancing Na+ removals via internal electron recycling. Salt adsorption capacities calculated using actual ion removals did not always agree with those estimated using changes in solution conductivity, with the largest disagreement observed when conductivity data were corrected for pH changes. Our results highlight that faradaic reactions, particularly oxygen reduction reactions, can contribute to asymmetrical removals of monovalent ions in flow-through CDI. DA - 2020/9/15/ PY - 2020/9/15/ DO - 10.1016/j.watres.2020.116044 VL - 183 SP - SN - 1879-2448 KW - Desalination KW - Capacitive deionization KW - Faradaic reactions ER - TY - JOUR TI - Effects of aging on asphalt mixture and pavement performance AU - Saleh, Nooralhuda F. AU - Keshavarzi, Behrooz AU - Rad, Farhad Yousefi AU - Mocelin, Douglas AU - Elwardany, Michael AU - Castorena, Cassie AU - Underwood, B. Shane AU - Kim, Y. Richard T2 - CONSTRUCTION AND BUILDING MATERIALS AB - This study investigates the effects of long-term aging on pavement performance under realistic traffic and thermal conditions. Using the NCHRP 09-54 aging procedure, a systematic study of the effects of aging on asphalt mixture linear viscoelastic and fatigue properties was conducted. The computational engine of FlexPAVE™ V1.1was modified to run more realistic pavement performance simulations. Results suggest that the effect of aging on pavement performance is evident only when simulations employ more realistic traffic and climatic conditions. In the absence of thermal conditions, the effect of changes in mixture properties on pavement performance is not significant. DA - 2020/10/20/ PY - 2020/10/20/ DO - 10.1016/j.conbuildmat.2020.120309 VL - 258 SP - SN - 1879-0526 KW - Aging KW - Fatigue KW - Pavement life KW - FlexPAVE (TM) ER - TY - JOUR TI - Search for Campylobacter spp. Reveals High Prevalence and Pronounced Genetic Diversity of Arcobacter butzleri in Floodwater Samples Associated with Hurricane Florence in North Carolina, USA T2 - Applied and Environmental Microbiology AB - Climate change and associated extreme weather events can have massive impacts on the prevalence of microbial pathogens in floodwaters. However, limited data are available on foodborne zoonotic pathogens such as Campylobacter or Arcobacter in hurricane-associated floodwaters in rural regions with intensive animal production. With a high density of intensive animal production as well as pronounced vulnerability to hurricanes, eastern North Carolina presents unique opportunities in this regard. Our findings revealed widespread incidence of the emerging zoonotic pathogen Arcobacter butzleri in floodwaters from Hurricane Florence. We encountered high and largely unexplored diversity while also noting the potential for regionally abundant and persistent clones. We noted pronounced partitioning of the floodwater genotypes into two source-associated clades. The data will contribute to elucidating the poorly understood ecology of this emerging pathogen and highlight the importance of surveillance of floodwaters associated with hurricanes and other extreme weather events for Arcobacter and other zoonotic pathogens. DA - 2020/8/7/ PY - 2020/8/7/ DO - 10.1128/aem.01118-20 UR - http://dx.doi.org/10.1128/aem.01118-20 KW - Arcobacter KW - Arcobacter butzleri KW - Campylobacter KW - Campylobacter jejuni KW - floodwaters KW - hurricane KW - MLST KW - genotype ER - TY - JOUR TI - The increasing district heating energy consumption of the building sector in China: Decomposition and decoupling analysis AU - Zhang, Linghui AU - Ma, Xin AU - Wang, Yixuan AU - Song, Rui AU - Li, Jiaojiao AU - Yuan, Weichang AU - Zhang, Shushen T2 - JOURNAL OF CLEANER PRODUCTION AB - The district heating system accounts for 40% energy consumption of the building sector in China and still has tremendous growth potential due to the urbanisation. However, few studies have conducted explicit quantification on the drivers and the sustainable development of the district heating energy consumption of the building sector (DHEB) in China, although previous aggregation analysis on whole building energy service could convey implications on the district heating systems. This study investigates the driving factors of the DHEB in China between 2004 and 2016 using a decomposition analysis that incorporates effects of energy mix, heat production technology structure, energy intensity, heating area, and population. The decoupling status between the DHEB and gross domestic product (GDP) in China is then analyzed based on the Tapio decoupling index, along with the contributions of each driving factor to the decoupling. The results show that the effects of district heating area and population dominate the increase in the DHEB, while the heating energy intensity is the strongest factor reducing the DHEB. In addition, the shares of coal and heating boilers positively contribute to the increase in 2004–2008, and have a negative effect in 2008–2016. The complete reverse trend is found in the shares of gas and combined heat and power (CHP) during the same period. These results are largely associated with the implementation of “coal to gas” and the “elimination of old boilers” pushed by the Chinese government. Furthermore, a weak decoupling effect is mainly found between China’s DHEB and GDP from 2004 to 2016. The heating energy intensity is the strongest factor promoting the decoupling, while the growth of the district heating area and population leads to a weak decoupling. DA - 2020/10/20/ PY - 2020/10/20/ DO - 10.1016/j.jclepro.2020.122696 VL - 271 SP - SN - 1879-1786 KW - District heating KW - Energy consumption KW - Building KW - Decomposition KW - Decoupling KW - China ER - TY - JOUR TI - Study of nanoscale deformation mechanisms in bulk hexagonal hydroxyapatite under uniaxial loading using molecular dynamics AU - Snyder, Alexander D. AU - Salehinia, Iman T2 - JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS AB - Hydroxyapatite (HAP) is a natural bioceramic which is currently used in scaffolds and coatings for the regrowth of osseous tissue but offers poor load-bearing capacity compared to other biomaterials. The deformation mechanisms responsible for the mechanical behavior of HAP are not well understood, although the advent of multiscale modeling offers the promise of improvements in many materials through computational materials science. This work utilizes molecular dynamics to study the nanoscale deformation mechanisms of HAP in uniaxial tension and compression. It was found that deformation mechanisms vary with loading direction in tension and compression leading to significant compression/tension asymmetry and crystal anisotropy. Bond orientation and geometry relative to the loading direction was found to be an indicator of whether a specific bond was involved in the deformation of HAP in each loading case. Tensile failure mechanisms were attributed to stretching and failure in loading case-specific ionic bond groups. The compressive failure mechanisms were attributed to coulombic repulsion in each case, although loading case-specific bond group rotation and displacement were found to affect specific failure modes. The elastic modulus was the highest for both tension and compression along the Z direction (i.e. normal to the basal plane), followed by Y and X. DA - 2020/10// PY - 2020/10// DO - 10.1016/j.jmbbm.2020.103894 VL - 110 SP - SN - 1878-0180 KW - Hexagonal hydroxyapatite KW - Nanoscale deformation mechanisms KW - Uniaxial loading KW - Molecular dynamics KW - Interface force field ER - TY - JOUR TI - Life-cycle modeling framework for electronic waste recovery and recycling processes AU - Jaunich, Megan Kramer AU - DeCarolis, Joseph AU - Handfield, Robert AU - Kemahlioglu-Ziya, Eda AU - Ranjithan, S. Ranji AU - Moheb-Alizadeh, Hadi T2 - RESOURCES CONSERVATION AND RECYCLING AB - Policies and regulations such as Extended Producer Responsibility (EPR) have been implemented to potentially increase the recycling rate of electronic waste (e-waste), but the cost and environmental impacts of associated collection, transportation, material recovery, material re-processing, and disposal could outweigh the benefits of recycling if the e-waste management system is not effectively designed and implemented. This paper presents a quantitative, holistic framework to systematically estimate life-cycle impacts and costs associated with e-waste management. This new framework was tested using data from the state of Washington's EPR program to represent e-waste collection, transportation, processing and disposal. Sensitivity of process-level life-cycle model outputs to parameter and input variability was also conducted. Drop-off using fossil-fuel-powered personal vehicles was found to be a key contributor to cost and carbon dioxide emissions. Decision-makers must account for drop-off and consider the feasibility of alternate e-waste aggregation strategies to ensure life-cycle benefits of e-waste recycling are maximized. DA - 2020/10// PY - 2020/10// DO - 10.1016/j.resconrec.2020.104841 VL - 161 SP - SN - 1879-0658 KW - life-cycle model KW - end-of-life management KW - life cycle assessment KW - electronic waste KW - waste management KW - producer responsibility ER - TY - JOUR TI - Fusion-Based Hypoxia Estimates: Combining Geostatistical and Mechanistic Models of Dissolved Oxygen Variability AU - Matli, Venkata Rohith Reddy AU - Laurent, Arnaud AU - Fennel, Katja AU - Craig, Kevin AU - Krause, Jacob AU - Obenour, Daniel R. T2 - Environmental Science & Technology AB - The need to characterize and track coastal hypoxia has led to the development of geostatistical models based on in situ observations of dissolved oxygen (DO) and mechanistic models based on a representation of biophysical processes. To integrate the benefits of these two distinct modeling approaches, we develop a space–time geostatistical framework for synthesizing DO observations with hydrodynamic–biogeochemical model simulations and meteorological time series (as covariates). This fusion-based approach is used to estimate hypoxia in the northern Gulf of Mexico across summers from 1985 to 2017. Deterministic trends with dynamic covariates explain over 35% of the variability in DO. Moreover, cross-validation results indicate that 58% of DO variability is explained when combining these trends with spatiotemporal interpolation, which is substantially better than mechanistic or conventional geostatistical hypoxia modeling alone. The fusion-based approach also reduces hypoxic area uncertainties by 11% on average and up to 40% in months with sparse sampling. Moreover, our new estimates of mean summer hypoxic area changed by >10% in a majority of years, relative to previous geostatistical estimates. These fusion-based estimates can be a valuable resource when assessing the influence of hypoxia on the coastal ecosystem. DA - 2020/10/20/ PY - 2020/10/20/ DO - 10.1021/acs.est.0c03655 VL - 54 IS - 20 SP - 13016-13025 UR - https://doi.org/10.1021/acs.est.0c03655 ER - TY - JOUR TI - Finite-Element Modeling of Landfills to Estimate Heat Generation, Transport, and Accumulation AU - Hao, Zisu AU - Barlaz, Morton A. AU - Ducoste, Joel J. T2 - Journal of Geotechnical and Geoenvironmental Engineering AB - In North America, temperatures nearing 100°C have been reported in several municipal solid waste landfills. However, the temporal and spatial-dependent processes that result in excessive heat accumulation are not well understood. The objective of this study was to develop a transient finite-element three-dimensional model that incorporates gas-liquid-heat reactive transfer in a landfill with biotic and abiotic reactions and spatially dependent heat transfer processes to better understand heat generation, accumulation, and propagation. The model incorporates gas-liquid-heat reactive transfer with aerobic and anaerobic biological reactions, anaerobic metal corrosion, and ash hydration and carbonation. Increasing boundary temperature, biological reaction rates, and landfill height increase the maximum temperature in the central region of a landfill, whereas the impact of thermal properties of municipal solid waste (MSW) is small. Simulation results predict that placement of ash near the corner of a landfill reduces the size of the elevated temperature region relative to placement in the landfill center. Mixing heat-generating wastes (ash or Al) with MSW decreases maximum temperatures but results in elevated temperatures over a larger fraction of the landfill volume relative to segregated ash disposal. DA - 2020/12// PY - 2020/12// DO - 10.1061/(ASCE)GT.1943-5606.0002403 VL - 146 IS - 12 SP - 04020134 J2 - J. Geotech. Geoenviron. Eng. LA - en OP - SN - 1090-0241 1943-5606 UR - http://dx.doi.org/10.1061/(ASCE)GT.1943-5606.0002403 DB - Crossref ER - TY - JOUR TI - Accounting for erroneous model structures in biokinetic process models AU - Villez, Kris AU - Del Giudice, Dario AU - Neumann, Marc B. AU - Rieckermann, Jorg T2 - RELIABILITY ENGINEERING & SYSTEM SAFETY AB - In engineering practice, model-based design requires not only a good process-based model, but also a good description of stochastic disturbances and measurement errors to learn credible parameter values from observations. However, typical methods use Gaussian error models, which often cannot describe the complex temporal patterns of residuals. Consequently, this results in overconfidence in the identified parameters and, in turn, optimistic reactor designs. In this work, we assess the strengths and weaknesses of a method to statistically describe these patterns with autocorrelated error models. This method produces increased widths of the credible prediction intervals following the inclusion of the bias term, in turn leading to more conservative design choices. However, we also show that the augmented error model is not a universal tool, as its application cannot guarantee the desired reliability of the resulting wastewater reactor design. DA - 2020/11// PY - 2020/11// DO - 10.1016/j.ress.2020.107075 VL - 203 SP - SN - 1879-0836 KW - Bias description KW - Kinetic model KW - Process design KW - Wastewater treatment KW - Uncertainty ER - TY - JOUR TI - Effect of cross-chamber flow electrode recirculation on pH and faradaic reactions in capacitive deionization AU - Liu, Fei AU - Coronell, Orlando AU - Call, Douglas F. T2 - DESALINATION AB - Mitigating faradaic reactions is critical for improving charge efficiency, reducing energy consumption, and protecting electrodes from degradation during desalination in capacitive deionization (CDI). In this study, we examined the influence of recirculating flow electrodes (FEs) within their respective anode and cathode chambers [within-chamber (WC)] or across them [cross-chamber (CC)] on pH, faradaic reactions, and energy demand under constant current operation. By changing from WC to CC (without FEs), the difference in pH between the anode and cathode chambers decreased from 10 to 4.5 units. Adding FEs to CC recirculation further reduced the pH gradient between anode and cathode chambers and resulted in the most stable pH (10.4 ± 0.08) of all treatments. We attributed the improvements in CC recirculation to faradaic consumption of anode-generated H+ at the cathode and neutralization of H+ and OH− via water formation. The capacitive behavior of FEs reduced several faradaic reactions by decreasing the whole-cell voltage. The energy consumption by the electrodes was reduced by 25% for the anode and 35% for the cathode when FEs were operated in CC instead of WC recirculation. These findings indicate that continuously recirculating FEs across the anode and cathode chambers can minimize detrimental faradaic reactions and pH changes in FE-CDI. DA - 2020/10/15/ PY - 2020/10/15/ DO - 10.1016/j.desal.2020.114600 VL - 492 SP - SN - 1873-4464 KW - Desalination KW - Capacitive deionization KW - Faradaic reactions KW - Flow electrodes ER - TY - JOUR TI - Characterization of Limit State for Seismic Fragility Assessment of T-Joints in Piping System AU - Dubey, Ankit R. AU - Gupta, Abhinav AU - Cho, Sung Gook T2 - JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME AB - Abstract Fragility assessment requires characterization of a component or system's performance through a performance function/limit-state equation. The exceedance of limit-state is representative of failure or damage state. For the purposes of evaluating piping fragility, characterizing the behavior of T-joints through an appropriate performance function is critical, as failures in piping are generally localized at the location of T-joints, elbows, and nozzles. Past studies have utilized a monotonic rotation-based performance function. However, the existing criteria does not account for the effect of cyclic behavior. As observed during prior experimental studies, the T-joint behavior under cyclic loading is different from that under monotonic loading, and therefore, it is important to include the effects of cyclic behavior while characterizing a performance function. Moreover, the monotonic rotation-based performance function could not replicate all the leakage locations observed during experimental studies on a full-scale two-story piping system. Therefore, it is important to develop a new limit-state for accurate piping fragility assessment. This paper presents the development of a new limit state which considers the cyclic behavior of a T-joint and quantifies the number of cycles to failure. DA - 2020/10/1/ PY - 2020/10/1/ DO - 10.1115/1.4047041 VL - 142 IS - 5 SP - SN - 1528-8978 KW - seismic fragility KW - piping KW - threaded T-joint KW - limit-state ER - TY - JOUR TI - Simulation of the asphalt concrete stiffness degradation using simplified viscoelastic continuum damage model AU - Hernandez-Fernandez, Noe AU - Underwood, B. Shane AU - Ossa-Lopez, Alexandra T2 - INTERNATIONAL JOURNAL OF FATIGUE AB - A procedure based on the simplified viscoelastic continuum damage model is developed to simulate asphalt concrete stiffness degradation caused by the application of cyclic loads. Several tests are performed to characterize the linear viscoelastic and fatigue damage properties of four asphalt mixtures. It was found that the piecewise approach proposed to simulate the stiffness evolution successfully describes the damage growth under loads applications. It was also found that the exponential model used to fit the characteristic curves best describes the stiffness evolution for the entire load history. Finally, stiffness evolution simulations showed higher fatigue resistance for polymer-modified mixtures. DA - 2020/11// PY - 2020/11// DO - 10.1016/j.ijfatigue.2020.105850 VL - 140 SP - SN - 1879-3452 KW - Asphalt concrete KW - Linear viscoelastic KW - Cyclic fatigue KW - Damage growth KW - Stiffness evolution ER - TY - JOUR TI - Low-temperature performance grade characterisation of asphalt binder using the dynamic shear rheometer AU - Underwood, B. Shane AU - Castorena, Cassie T2 - INTERNATIONAL JOURNAL OF PAVEMENT ENGINEERING AB - Currently, the bending beam rheometer (BBR) test is the standard method for evaluating the low-temperature performance grade (PG) of asphalt binders. Despite its use, there are limitations with the BBR test with respect to the amount of asphalt binder needed for test specimens, the relative difficulty in preparing specimens, and the overall testing efficiency. On the contrary, the dynamic shear rheometer (DSR) is an efficient test method that is widely used to determine the PG at intermediate and high temperatures. In this study, DSR temperature-frequency sweep tests using the 8-mm parallel plate is proposed as an alternative to the BBR. The method takes advantage of the time-temperature superposition principle and linear viscoelastic interconversion to predict the BBR creep stiffness and m-values at 60 s from the modulus and phase angle measured by the DSR at intermediate temperatures. Two conversion methods were used to verify the ability to predict BBR properties using DSR testing based on 45 binders of diverse PG. The DSR-based method yields good agreement with measured BBR data. On average, the continuous low-temperature PG predicted using the DSR method is within 2.7°C of that measured using the BBR. DA - 2020/// PY - 2020/// DO - 10.1080/10298436.2020.1774766 KW - Asphalt binder KW - linear viscoelasticity KW - dynamic shear rheometer KW - bending beam rheometer KW - time-temperature superposition ER - TY - JOUR TI - Scientific Basis for Managing PFAS as a Chemical Class AU - Kwiatkowski, Carol F. AU - Andrews, David Q. AU - Birnbaum, Linda S. AU - Bruton, Thomas A. AU - DeWitt, Jamie C. AU - Knappe, Detlef R. U. AU - Maffini, Maricel V AU - Miller, Mark F. AU - Pelch, Katherine E. AU - Reade, Anna AU - Soehl, Anna AU - Trier, Xenia AU - Venier, Marta AU - Wagner, Charlotte C. AU - Wang, Zhanyun AU - Blum, Arlene T2 - ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS AB - This commentary presents a scientific basis for managing as one chemical class the thousands of chemicals known as PFAS (per- and polyfluoroalkyl substances). The class includes perfluoroalkyl acids, perfluoroalkylether acids, and their precursors; fluoropolymers and perfluoropolyethers; and other PFAS. The basis for the class approach is presented in relation to their physicochemical, environmental, and toxicological properties. Specifically, the high persistence, accumulation potential, and/or hazards (known and potential) of PFAS studied to date warrant treating all PFAS as a single class. Examples are provided of how some PFAS are being regulated and how some businesses are avoiding all PFAS in their products and purchasing decisions. We conclude with options for how governments and industry can apply the class-based approach, emphasizing the importance of eliminating non-essential uses of PFAS, and further developing safer alternatives and methods to remove existing PFAS from the environment. DA - 2020/8/11/ PY - 2020/8/11/ DO - 10.1021/acs.estlett.0c00255 VL - 7 IS - 8 SP - 532-543 SN - 2328-8930 UR - https://doi.org/10.1021/acs.estlett.0c00255 ER - TY - JOUR TI - P92 steel creep-fatigue interaction responses under hybrid stress-strain controlled loading and a life prediction model AU - Zhang, Tianyu AU - Wang, Xiaowei AU - Ji, Yunnan AU - Zhang, Wei AU - Hassan, Tasnim AU - Gong, Jianming T2 - INTERNATIONAL JOURNAL OF FATIGUE AB - In contrast to conventional strain-controlled creep-fatigue interaction (CCFI) loadings, a novel hybrid stress- and strain-controlled creep-fatigue interaction (HCFI) loadings were developed on P92 steel. Dwell stresses ranging from 140 MPa to 170 MPa, and dwell periods of 300 s, 600 s and 1800 s were employed at 625 °C. The test responses demonstrate that cyclic softening and hardening effects lead to complicated cyclic responses. In addition, the failure life under HCFI loading is observed to be reduced with the dwell stress and dwell period. Finally, a viscosity-based model is proposed to predict the lifetime of both HCFI and CCFI tests. DA - 2020/11// PY - 2020/11// DO - 10.1016/j.ijfatigue.2020.105837 VL - 140 SP - SN - 1879-3452 KW - Hybrid stress- and strain-controlled creep-fatigue interaction loading KW - Cyclic responses KW - Life prediction ER - TY - JOUR TI - Predictive Framework for Modeling Changes in Asphalt Mixture Moduli with Oxidative Aging AU - Saleh, Nooralhuda F. AU - Mocelin, Douglas AU - Yousefi Rad, Farhad AU - Castorena, Cassie AU - Underwood, B. Shane AU - Kim, Y. Richard T2 - TRANSPORTATION RESEARCH RECORD AB - This paper presents a predictive framework for asphalt mixture moduli as a function of aging time with two levels of sophistication. This work is built on the method currently implemented in Pavement mechanistic-empirical (ME) that uses an effective time/frequency concept based on time-aging superposition to model the effect of aging on a mixture’s modulus. Time-aging superposition implies that an asphalt mixture’s modulus mastercurves, corresponding to different aging levels, coincide when they are shifted horizontally on the log-frequency axis. This study improves the accuracy of the existing model by decoupling the time-temperature and time-aging shifts. The new framework also uses the binder dynamic shear modulus | G*| as an aging index instead of the viscosity, which is used in Pavement ME. The | G*| aging index is used to calculate an effective frequency at short-term aging (STA), which is then used in the asphalt mixture sigmoidal model to calculate the corresponding asphalt mixture modulus with aging. The pavement aging model introduced by NCHRP 09-54 predicts log | G*| at 64°C and 10 rad/s for a specific field-aged condition and pavement depth. The proposed framework can use the predicted log | G*| to predict the mixture’s corresponding dynamic modulus (| E*|) at that aging level and pavement depth. Level 1 of this framework requires characterizing the | G*| at STA and calibrating the NCHRP 09-54 pavement aging model as well as measuring the mixture | E*| at STA. Level 2 does not require any binder testing, providing relatively less accurate predictions but relieving some testing requirements. DA - 2020/10// PY - 2020/10// DO - 10.1177/0361198120938775 VL - 2674 IS - 10 SP - 79-93 SN - 2169-4052 ER - TY - JOUR TI - The Network Coordination Office of NHERI (Natural Hazards Engineering Research Infrastructure) AU - Blain, Cheryl Ann AU - Bobet, Antonio AU - Browning, JoAnn AU - Edge, Billy L. AU - Holmes, William AU - Johnson, David R. AU - LaChance, Marti AU - Ramirez, Julio AU - Robertson, Ian AU - Smith, Tom AU - Thompson, Chris AU - Vielma, Karina AU - Zehner, Dan AU - Zuo, Delong T2 - FRONTIERS IN BUILT ENVIRONMENT AB - NHERI, or the Natural Hazards Engineering Research Infrastructure, is supported by the United States National Science Foundation (NSF) as a distributed, multi-user national facility that provides the natural hazards research community with access to a powerful research infrastructure. NHERI is comprised of separate research infrastructure awards for a Network Coordination Office (NCO), Cyberinfrastructure, a Computational Modeling and Simulation Center, eight Experimental Facilities, and CONVERGE (an initiative to advance social sciences and interdisciplinary research). Awards made for NHERI contribute to NSF's role in the National Earthquake Hazards Reduction Program and the National Windstorm Impact Reduction Program of the United States. The mission of NHERI is to provide the earthquake, wind, coastal engineering, and social sciences communities with access to research infrastructure, education, and community outreach activities focused on improving the resilience and sustainability of the civil infrastructure against earthquakes, windstorms, and associated natural events such as tsunami and coastal storm surge. In this paper, the role and key NHERI activities are described for the NCO, which is led by Purdue University, along with partner institutions—the University of Texas at San Antonio, North Carolina State University, Texas Tech University, the U.S. Naval Research Laboratory, and the University of Hawaii at Manoa. The NHERI NCO serves as a focal point and leader of a multi-hazards research community, and maintains a community-based NHERI science plan. It manages scheduling of our partner NHERI Experimental Facilities and coordinates all components to ensure effective and fair governance, efficient testing and user support within a safe environment. Another important role of the NCO is to lead NHERI-wide educational and outreach activities. The NCO works to develop strategic national and international partnerships and to coordinate NHERI activities with other awardee components to form a cohesive and fully-integrated global natural hazards engineering research infrastructure that fosters collaboration in new ways. DA - 2020/7/28/ PY - 2020/7/28/ DO - 10.3389/fbuil.2020.00108 VL - 6 SP - SN - 2297-3362 KW - natural hazards KW - network coordination KW - NHERI KW - earthquake KW - storm surge KW - tsunami KW - wind ER - TY - JOUR TI - Recent increases of rainfall and flooding from tropical cyclones (TCs) in North Carolina (USA): implications for organic matter and nutrient cycling in coastal watersheds AU - Paerl, Hans W. AU - Hall, Nathan S. AU - Hounshell, Alexandria G. AU - Rossignol, Karen L. AU - Barnard, Malcolm A. AU - Luettich, Richard A., Jr. AU - Rudolph, Jacob C. AU - Osburn, Christopher L. AU - Bales, Jerad AU - Harding, Lawrence W., Jr. T2 - BIOGEOCHEMISTRY AB - Coastal North Carolina experienced 36 tropical cyclones (TCs), including three floods of historical significance in the past two decades (Hurricanes Floyd-1999, Matthew-2016 and Florence-2018). These events caused catastrophic flooding and major alterations of water quality, fisheries habitat and ecological conditions of the Albemarle-Pamlico Sound (APS), the second largest estuarine complex in the United States. Continuous rainfall records for coastal NC since 1898 reveal a period of unprecedented high precipitation storm events since the late-1990s. Six of seven of the “wettest” storm events in this > 120-year record occurred in the past two decades, identifying a period of elevated precipitation and flooding associated with recent TCs. We examined storm-related freshwater discharge, carbon (C) and nutrient, i.e., nitrogen (N) and phosphorus (P) loadings, and evaluated contributions to total annual inputs in the Neuse River Estuary (NRE), a major sub-estuary of the APS. These contributions were highly significant, accounting for > 50% of annual loads depending on antecedent conditions and storm-related flooding. Depending on the magnitude of freshwater discharge, the NRE either acted as a “processor” to partially assimilate and metabolize the loads or acted as a “pipeline” to transport the loads to the APS and coastal Atlantic Ocean. Under base-flow, terrestrial sources dominate riverine carbon. During storm events these carbon sources are enhanced through the inundation and release of carbon from wetlands. These findings show that event-scale discharge plays an important and, at times, predominant role in C, N and P loadings. We appear to have entered a new climatic regime characterized by more frequent extreme precipitation events, with major ramifications for hydrology, cycling of C, N and P, water quality and habitat conditions in estuarine and coastal waters. DA - 2020/9// PY - 2020/9// DO - 10.1007/s10533-020-00693-4 VL - 150 IS - 2 SP - 197-216 SN - 1573-515X KW - Tropical cyclones KW - Flooding KW - Organic carbon KW - Nutrient cycling KW - Phytoplankton KW - Estuarine KW - Coastal KW - North carolina ER - TY - JOUR TI - Toxicity of Balb-c mice exposed to recently identified 1,1,2,2-tetrafluoro-2-[1,1,1,2,3,3-hexafluoro-3-(1,1,2,2-tetrafluoroethoxy)propan-2-yl]oxyethane-1-sulfonic acid (PFESA-BP2) AU - Lang, Johnsie R. AU - Strynar, Mark J. AU - Lindstrom, Andrew B. AU - Farthing, Amy AU - Huang, Hwa AU - Schmid, Judith AU - Hill, Donna AU - Chernoff, Neil T2 - TOXICOLOGY AB - 1,1,2,2-tetrafluoro-2-[1,1,1,2,3,3-hexafluoro-3-(1,1,2,2-tetrafluoroethoxy)propan-2-yl]oxyethane-1-sulfonic acid (PFESA-BP2) was first detected in 2012 in the Cape Fear River downstream of an industrial manufacturing facility. It was later detected in the finished drinking water of municipalities using the Cape Fear River for their water supply. No toxicology data exist for this contaminant despite known human exposure. To address this data gap, mice were dosed with PFESA-BP2 at 0, 0.04, 0.4, 3, and 6 mg/kg-day for 7 days by oral gavage. As an investigative study, the final dose groups evolved from an original dose of 3 mg/kg which produced liver enlargement and elevated liver enzymes. The dose range was extended to explore a no effect level. PFESA-BP2 was detected in the sera and liver of all treated mice. Treatment with PFESA-BP2 significantly increased the size of the liver for all mice at 3 and 6 mg/kg-day. At the 6 mg/kg-day dose, the liver more than doubled in size compared to the control group. Male mice treated with 3 and 6 mg/kg-day and females treated with 6 mg/kg-day demonstrated significantly elevated serum markers of liver injury including alanine aminotransferase (ALT), glutamate dehydrogenase (GLDH), and liver/body weight percent. The percent of PFESA-BP2 in serum relative to the amount administered was similar in male and female mice, ranged from 9 to 13 %, and was not related to dose. The percent accumulation in the liver of the mice varied by sex (higher in males), ranged from 30 to 65 %, and correlated positively with increasing dose level. DA - 2020/8// PY - 2020/8// DO - 10.1016/j.tox.2020.152529 VL - 441 SP - SN - 0300-483X KW - NBP2 KW - PFESA-BP2 KW - PFASs KW - In vivo KW - Bioaccumulation KW - 1,1,2,2-Tetrafluoro-2-[1,1,1,2,3,3-hexafluoro-3-(1,1,2,2-tetrafluoroethoxy)propan-2-yl]oxyethane-1-sulfonic acid ER - TY - JOUR TI - Least cost energy system pathways towards 100% renewable energy in Ireland by 2050 AU - Yue, Xiufeng AU - Patankar, Neha AU - Decarolis, Joseph AU - Chiodi, Alessandro AU - Rogan, Fionn AU - Deane, J. P. AU - O'Gallachoir, Brian T2 - ENERGY AB - Studies focusing on 100% renewable energy systems have emerged in recent years; however, existing studies tend to focus only on the power sector using exploratory approaches. This paper therefore undertakes a whole-system approach and explores optimal pathways towards 100% renewable energy by 2050. The analysis is carried out for Ireland, which currently has the highest share of variable renewable electricity on a synchronous power system. Large numbers of scenarios are developed using the Irish TIMES model to address uncertainties. Results show that compared to decarbonization targets, focusing on renewable penetration without considering carbon capture options is significantly less cost effective in carbon mitigation. Alternative assumptions on bioenergy imports and maximum variability in power generation lead to very different energy mixes in bioenergy and electrification levels. All pathways suggest that indigenous bioenergy needs to be fully exploited and the current annual deployment rate of renewable electricity needs a boost. Pathways relying on international bioenergy imports are slightly cheaper and faces less economic and technical challenges. However, given the large future uncertainties, it is recommended that further policy considerations be given to pathways with high electrification levels as they are more robust towards uncertainties. DA - 2020/9/15/ PY - 2020/9/15/ DO - 10.1016/j.energy.2020.118264 VL - 207 SP - SN - 1873-6785 KW - 100% Renewable energy KW - Electrification KW - Energy system optimization model KW - Uncertainty analysis ER - TY - JOUR TI - Measurement of Novel, Drinking Water-Associated PFAS in Blood from Adults and Children in Wilmington, North Carolina AU - Kotlarz, Nadine AU - McCord, James AU - Collier, David AU - Lea, C. Suzanne AU - Strynar, Mark AU - Lindstrom, Andrew B. AU - Wilkie, Adrien A. AU - Islam, Jessica Y. AU - Matney, Katelyn AU - Tarte, Phillip AU - Polera, M. E. AU - Burdette, Kemp AU - DeWitt, Jamie AU - May, Katlyn AU - Smart, Robert C. AU - Knappe, Detlef R. U. AU - Hoppin, Jane A. T2 - ENVIRONMENTAL HEALTH PERSPECTIVES AB - Vol. 128, No. 7 ResearchOpen AccessMeasurement of Novel, Drinking Water-Associated PFAS in Blood from Adults and Children in Wilmington, North Carolinais corrected byErratum: “Measurement of Novel, Drinking Water-Associated PFAS in Blood from Adults and Children in Wilmington, North Carolina” Nadine Kotlarz, James McCord, David Collier, C. Suzanne Lea, Mark Strynar, Andrew B. Lindstrom, Adrien A. Wilkie, Jessica Y. Islam, Katelyn Matney, Phillip Tarte, M.E. Polera, Kemp Burdette, Jamie DeWitt, Katlyn May, Robert C. Smart, Detlef R.U. Knappe, and Jane A. Hoppin Nadine Kotlarz Department of Civil, Construction, and Environmental Engineering, North Carolina State University (NCSU), Raleigh, North Carolina, USA Department of Biological Sciences, NCSU, Raleigh, North Carolina, USA Center for Human Health and the Environment, NCSU, Raleigh, North Carolina, USA Search for more papers by this author , James McCord Center for Environmental Measurement and Modeling, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA Search for more papers by this author , David Collier Center for Human Health and the Environment, NCSU, Raleigh, North Carolina, USA Department of Pediatrics, Brody School of Medicine, East Carolina University (ECU), Greenville, North Carolina, USA Search for more papers by this author , C. Suzanne Lea Center for Human Health and the Environment, NCSU, Raleigh, North Carolina, USA Department of Public Health, ECU, Greenville, North Carolina, USA Search for more papers by this author , Mark Strynar Center for Environmental Measurement and Modeling, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA Search for more papers by this author , Andrew B. Lindstrom Center for Environmental Measurement and Modeling, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA Search for more papers by this author , Adrien A. Wilkie Department of Biological Sciences, NCSU, Raleigh, North Carolina, USA Department of Epidemiology, UNC Gillings School of Global Public Health, Chapel Hill, North Carolina, USA Search for more papers by this author , Jessica Y. Islam Department of Biological Sciences, NCSU, Raleigh, North Carolina, USA Department of Epidemiology, UNC Gillings School of Global Public Health, Chapel Hill, North Carolina, USA Search for more papers by this author , Katelyn Matney New Hanover County Health Department, Wilmington, North Carolina, USA Search for more papers by this author , Phillip Tarte New Hanover County Health Department, Wilmington, North Carolina, USA Search for more papers by this author , M.E. Polera Cape Fear River Watch, Wilmington, North Carolina, USA Search for more papers by this author , Kemp Burdette Cape Fear River Watch, Wilmington, North Carolina, USA Search for more papers by this author , Jamie DeWitt Center for Human Health and the Environment, NCSU, Raleigh, North Carolina, USA Department of Pharmacology and Toxicology, ECU, Greenville, North Carolina, USA Search for more papers by this author , Katlyn May Center for Human Health and the Environment, NCSU, Raleigh, North Carolina, USA Search for more papers by this author , Robert C. Smart Department of Biological Sciences, NCSU, Raleigh, North Carolina, USA Center for Human Health and the Environment, NCSU, Raleigh, North Carolina, USA Search for more papers by this author , Detlef R.U. Knappe Department of Civil, Construction, and Environmental Engineering, North Carolina State University (NCSU), Raleigh, North Carolina, USA Center for Human Health and the Environment, NCSU, Raleigh, North Carolina, USA Search for more papers by this author , and Jane A. Hoppin Address correspondence to Jane A. Hoppin, Department of Biological Sciences, Campus Box 7633, NC State University, Raleigh, NC 27695-7633 USA. Telephone: (919) 515-2918. Email: E-mail Address: [email protected] Department of Biological Sciences, NCSU, Raleigh, North Carolina, USA Center for Human Health and the Environment, NCSU, Raleigh, North Carolina, USA Search for more papers by this author Published:22 July 2020CID: 077005https://doi.org/10.1289/EHP6837Cited by:26AboutSectionsPDF Supplemental Materials ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmail AbstractBackground:From 1980 to 2017, a fluorochemical manufacturing facility discharged wastewater containing poorly understood per- and polyfluoroalkyl substances (PFAS) to the Cape Fear River, the primary drinking water source for Wilmington, North Carolina, residents. Those PFAS included several fluoroethers including HFPO-DA also known as GenX. Little is known about the bioaccumulation potential of these fluoroethers.Objective:We determined levels of fluoroethers and legacy PFAS in serum samples from Wilmington residents.Methods:In November 2017 and May 2018, we enrolled 344 Wilmington residents ≥6 years of age into the GenX Exposure Study and collected blood samples. Repeated blood samples were collected from 44 participants 6 months after enrollment. We analyzed serum for 10 fluoroethers and 10 legacy PFAS using liquid chromatography–high-resolution mass spectrometry.Results:Participants’ ages ranged from 6 to 86 y, and they lived in the lower Cape Fear Region for 20 y on average (standard deviation: 16 y). Six fluoroethers were detected in serum; Nafion by-product 2, PFO4DA, and PFO5DoA were detected in >85% of participants. PFO3OA and NVHOS were infrequently detected. Hydro-EVE was present in a subset of samples, but we could not quantify it. GenX was not detected above our analytical method reporting limit (2 ng/mL). In participants with repeated samples, the median decrease in fluoroether levels ranged from 28% for PFO5DoA to 65% for PFO4DA in 6 months due to wastewater discharge control. Four legacy PFAS (PFHxS, PFOA, PFOS, PFNA) were detected in most (≥97%) participants; these levels were higher than U.S. national levels for the 2015–2016 National Health and Nutrition Examination Survey. The sum concentration of fluoroethers contributed 24% to participants’ total serum PFAS (median: 25.3 ng/mL).Conclusion:Poorly understood fluoroethers released into the Cape Fear River by a fluorochemical manufacturing facility were detected in blood samples from Wilmington, North Carolina, residents. Health implications of exposure to these novel PFAS have not been well characterized. https://doi.org/10.1289/EHP6837IntroductionPer- and polyfluoroalkyl substances (PFAS) are a broad class of synthetic chemicals used to manufacture fluoropolymers, stain repellents, paper coatings, and fire-fighting foams (Kissa 2001). In addition to the PFAS produced for commercial purposes, other PFAS can be formed as by-products or impurities of fluorochemical production (Dinglasan et al. 2004; James and Franklin 1966; Liang et al. 1998; Moore et al. 1966). Many PFAS have high aqueous solubility and are persistent in the environment. As a result, PFAS are stable in water and can travel over long distances in freshwater and marine ecosystems (Banzhaf et al. 2017; Möller et al. 2010). PFAS releases into the environment can therefore impact drinking water sources both near and far from the source of contamination (Hu et al. 2016; Ingelido et al. 2018; Mak et al. 2009; Pan et al. 2018; Sharma et al. 2016; Sun et al. 2016).PFAS are not substantially removed by most conventional drinking-water treatment processes, including coagulation, flocculation, sedimentation, filtration, and disinfection (Rahman et al. 2014). Elevated concentrations of PFAS have been reported in the finished drinking water of community water systems that source water from areas with industrial facilities producing or using PFAS (Graber et al. 2019; Hu et al. 2016). Notably, perfluorooctanoic acid (PFOA) releases from a fluorochemical plant near Parkersburg, West Virginia, resulted in parts-per-billion levels of PFOA in drinking water sourced from contaminated wells; in the community, tap water consumption was a significant predictor of serum PFOA levels (Emmett et al. 2006; Hoffman et al. 2011). Human exposure to PFAS [PFOA and perfluorooctane sulfonate (PFOS) are the most studied to date] has been associated with thyroid disease, ulcerative colitis, elevated cholesterol levels, developmental delays, liver disease, kidney and testicular cancer, and immunosuppression (ATSDR 2018; DeWitt et al. 2009; Steenland et al. 2010; Sunderland et al. 2019).In North Carolina, a 2,150-acre fluorochemical manufacturing facility (i.e., Fayetteville Works) (Figure 1) discharged process wastewater to the Cape Fear River as early as 1980 (Wagner and Buckland 2017). Several poorly understood PFAS, including hexafluoropropylene oxide dimer acid (HFPO-DA or GenX), have been detected in water samples collected downriver of the facility’s effluent discharge point (Hopkins et al. 2018; McCord and Strynar 2019; McCord et al. 2018; Strynar et al. 2015; Sun et al. 2016; Zhang et al. 2019). These PFAS are collectively referred to as fluoroethers because they have the traditional perfluoroalkyl carbon chains characteristic of legacy PFAS, such as PFOA, but the chains are interrupted by ether oxygen(s) (see Figure S1) (Strynar et al. 2015). The released fluoroethers, including GenX, were generated as by-products of fluoropolymer production at Fayetteville Works facility (Hopkins et al. 2018; McCord and Strynar 2019). Human exposure to by-products of fluorochemical manufacturing has not been studied to date.Figure 1. Cape Fear River Basin, North Carolina, United States. Note: PFAS, per- and polyfluoroalkyl substances.Approximately 80 miles downriver of Fayetteville Works is the raw water intake for the Cape Fear Public Utility Authority (CFPUA), which provides drinking water to approximately 200,000 people in New Hanover County, home to Wilmington, North Carolina. Raw water concentrations of the fluoroethers were similar to treated water concentrations because the fluoroethers were not measurably removed by CFPUA’s water treatment processes, which included several advanced steps (i.e., raw and settled water ozonation, biofiltration, and ultraviolet light disinfection) (Hopkins et al. 2018). In early June 2017, the public became aware of the presence of GenX in their drinking water (Hagerty 2017). Community concern and subsequent action by the North Carolina Department of Environmental Quality (NC DEQ) resulted in the fluorochemical manufacturer reducing its wastewater discharges to the Cape Fear River on 21 June 2017, and by September 2017, the facility stopped discharging process wastewater containing PFAS into the Cape Fear River (NC DEQ 2017). As a result, the GenX concentration in Wilmington’s drinking water source dropped from approximately 700 ng/L before discharge control to approximately 100 ng/L 1 week later (Hopkins et al. 2018; Sun et al. 2016; Zhang et al. 2019).We initiated The GenX Exposure Study in November 2017 to answer community members’ questions about their exposure to GenX and other PFAS. We included in our analysis fluoroethers that were by-products of fluorochemical manufacturing at Fayetteville Works as well as legacy PFAS historically used throughout the Cape Fear River Basin. We report here the initial findings for serum PFAS levels measured in a Wilmington, North Carolina, population.MethodsStudy PopulationIn November 2017 and May 2018, we recruited individuals from New Hanover County, North Carolina, to participate in the GenX Exposure Study. We partnered with Cape Fear River Watch, a local nongovernmental organization focusing on water quality in the region; the New Hanover County Health Department; the New Hanover County NAACP; and informal community partners to inform the public about the study. Press releases, news stories, public service announcements, recruitment flyers, social media platforms, and the study website ( https://genxstudy.ncsu.edu/) were used to promote the study.CFPUA distributes drinking water to the City of Wilmington and unincorporated areas of New Hanover County not served by privately owned systems. CFPUA operates three treatment plants with separate distribution systems: One plant sources water from the lower Cape Fear River, and the other two from various groundwater sources (CFPUA 2020b). Most (153,200 or 80%) of the 190,500 people served by CFPUA receive water from the lower Cape Fear River (NC Drinking Water Watch 2020). The Richardson and Monterey Heights groundwater treatment plants serve 37,250 people collectively.Study participants were required to be current residents of New Hanover County, ≥6 years of age, and to have lived in a home served with CFPUA drinking water for at least 12 months prior to November 2017 (the start of enrollment). Up to four individuals per household were allowed to participate. We excluded pregnant women and people who were human immunodeficiency virus- or hepatitis C-positive. Individuals were recruited in both English and Spanish. The majority of our participants were recruited in November 2017, with a smaller, targeted recruitment in May 2018. In November, interested individuals contacted the study office to be screened for eligibility. Eligible individuals were scheduled for a clinic visit at the New Hanover County Health Department during the weekend of 10–12 November 2017. We conducted a second recruitment of participants in May 2018, aimed at increasing participation of African Americans. We joined the annual health fair at the MLK Center in Wilmington, hosted by the New Hanover County NAACP. Recruitment, enrollment, and biological sample collection took place at the MLK Center on 5 May 2018. We also scheduled repeat blood and urine collection from a random sample of the November 2017 participants.All study participants provided written informed consent to participate. All phases of the study were conducted in compliance with the North Carolina State University Institutional Review Board.Data CollectionDuring clinic visits, we consented participants, administered a questionnaire, collected biological samples (blood and urine), and measured height and weight. Study staff administered a questionnaire to each participant at the clinic visit to collect information on demographics, drinking water habits, residential history, health history, and PFAS exposures other than drinking water. Children completed a shortened version of the adult questionnaire. Parents provided the residential history for their children.Trained phlebotomists collected nonfasting blood samples from participants. For participants who were ≥11 years of age, four tubes of blood (two red-top tubes for serum, two ethylenediaminetetraacetic acid (EDTA) tubes for whole blood or plasma) were collected. For children 6–10 years of age, two red-top tubes for serum were collected. Serum tubes were spun at 1,300×g for 10 min in a Sorvall RT 600D centrifuge at room temperature. Serum was aliquoted into transfer tubes. One EDTA tube was processed for plasma; the remainder was saved as whole blood. Spot urine samples were provided by study participants during the clinic visit. Urine and blood samples were stored on dry ice and transported to East Carolina University (Greenville, NC) and stored at −80°C. A 2-mL aliquot of serum was shipped on dry ice to the U.S. Environmental Protection Agency (EPA) in Research Triangle Park, North Carolina, where they were stored at −80°C until analysis.PFAS Analysis in BloodAnalytical standards.Native standards for GenX, perfluorobutanoic acid (PFBA), perfluoropentanoic acid (PFPeA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), PFOA, perfluorononanoic acid (PFNA), perfluorobutane sulfonic acid (PFBS), perfluorohexane sulfonic acid (PFHxS), PFOS, and 6:2 fluorotelomer sulfonate (6:2 FTS) and mass-labeled standards for GenX, PFBA, PFHxA, PFOA, PFNA, PFHxS, PFOS, and 6:2 FTS were purchased dissolved in methanol from Wellington Laboratories (see Table S1). Analytical standards for perfluoro-2-methoxyacetic acid (PFMOAA), perfluoro-2-methoxypropanoic acid, 2,3,3,3-tetrafluoro-2-(pentafluoroethoxy)propanoic acid, perfluoro-2-ethoxypropanoic acid (PEPA), perfluoro-3,5-dioxahexanoic acid (PFO2HxA), perfluoro-3,5,7-trioxaoctanoic acid (PFO3OA), perfluoro-3,5,7,9-tetraoxadecanoic acid (PFO4DA), perfluoro-3,5,7,9,11-pentaoxadodecanoic acid (PFO5DoA), and 1,1,2,2-tetrafluoro-2-(1,2,2,2-tetrafluoroethoxy)ethanesulfonic acid (NVHOS) and for perfluoro-3,6-dioxa-4-methyl-7-octene-1-sulfonic acid (Nafion by-product 1), and perfluoro-2-{[perfluoro-3-(perfluoroethoxy)-2-proanyl]oxy}ethanesulfonic acid (Nafion by-product 2) were acquired as aqueous solutions (1,000 ng/μL) from the Chemours Company because there were no commercial sources. The identity of each standard was confirmed by high-resolution mass spectrometry (HRMS). A mixed PFAS standard stock solution was prepared in methanol at 0.1 ng/μL.Sample preparation.Fifty microliters of serum was transferred into 2-mL polypropylene tubes and 100μL0.1M formic acid containing mass-labeled standards (6.25 ng/mL) was added to denature serum proteins. Each sample was then vortex mixed and 450μL cold (−20°C) acetonitrile was added to precipitate proteins. The sample was vortex mixed again and centrifuged at 12,500×g for 5 min in an IEC CL31R Multispeed Centrifuge (Thermo Scientific) at room temperature. Finally, a 100-μL aliquot of the acetonitrile supernatant was placed into a liquid chromatography (LC) vial with 100μL0.4 mM ammonium formate buffer (1:1 mixture).Sample analysis.Measurements for 20 PFAS, 10 fluoroethers, and 10 legacy PFAS (Table 1) in serum were conducted using LC-HRMS. Each serum sample was analyzed using a Thermo Vanquish ultra-performance liquid chromatograph coupled to a Thermo Orbitrap Fusion mass spectrometer. Using a 25-μL injection volume, PFAS were separated on an Accucore Vanquish C18+LC column (100×2.1mm, 1.5μL particle diameter). The mobile phases were 95:5% vol/vol water:acetonitrile with 0.4 mM ammonium formate (Eluent A) and 5:95% vol/vol water:acetonitrile with 0.4 mM ammonium formate (Eluent B), with a flow rate of 300μL/min. The LC method used a 3-min pre-equilibration time at 10% B followed by a linear gradient from 10% to 100% over 10 min with a 3-min hold at 100% B. The mass spectrometer was run in full scan mode with a mass range of 100–700 Da and 120,000 resolving power at m/z 200.Table 1 Ten fluoroethers and 10 legacy PFAS measured for in serum samples in the GenX exposure study.Table 1 has eight columns, namely, Short name, U.S. EPA registry name, Formula, CAS number (hyperlinked to U.S. EPA Chemicals Dashboard superscript a), DTXSID superscript b, Monoisotopic mass, deprotonated, number of fluorinated carbons, and Chain length superscript c.Short nameU.S. EPA registry nameFormulaCASN (hyperlinked to U.S. EPA Chemicals Dashboarda)DTXSIDbMonoisotopic mass, deprotonated# of fluorinated carbonsChain lengthcFluoroethers HFPO-DA (GenX)Hexafluoropropylene oxide dimer acidC6HF11O3 13252-13-670880215328.967757 PMPAPerfluoro-2-methoxypropanoic acidC4HF7O3 13140-29-980528474228.974135 PEPAPerfluoro-2-ethoxypropanoic acidC5HF9O3 267239-61-260896486278.970946 PFO2HxAPerfluoro-3,5-dioxahexanoic acidC4HF7O4 39492-88-150892351244.969136 PFO3OAPerfluoro-3,5,7-trioxaoctanoic acidC5HF9O5 39492-89-220892348310.960848 PFO4DAPerfluoro-3,5,7,9-tetraoxadecanoic acidC6HF11O6 39492-90-590723993376.9525510 PFO5DoAPerfluoro-3,5,7,9,11-pentaoxadodecanoic acidC7HF13O7 39492-91-650723994442.9442612 NVHOS1,1,2,2-Tetrafluoro-2-(1,2,2,2-tetrafluoroethoxy)ethanesulfonic acidC4H2F8O4S 801209-99-480904754296.947346 Nafion by-product 1Perfluoro-3,6-dioxa-4-methyl-7-octene-1-sulfonic acidC7HF13SO5 29311-67-930892354442.9264710 Nafion by-product 2Perfluoro-2-{[perfluoro-3-(perfluoroethoxy)-2-propanyl]oxy}ethanesulfonic acidC7H2F14SO5 749836-20-210892352462.9327710Legacy PFAS PFBAPerfluorobutanoic acidC4HF7O2 375-22-44059916212.979234 PFPeAPerfluoropentanoic acidC5HF9O2 2706-90-36062599262.976045 PFHxAPerfluorohexanoic acidC6HF11O2 307-24-43031862312.972856 PFHpAPerfluoroheptanoic acidC7HF13O2 375-85-91037303362.969667 PFOAPerfluorooctanoic acidC8HF15O2 335-67-18031865412.966478 PFNAPerfluorononanoic acidC9HF17O2 375-95-18031863462.963289 PFBSPerfluorobutane sulfonic acidC4HF9SO3 375-73-55030030298.942945 PFHxSPerfluorohexane sulfonic acidC6HF13SO3 355-46-47040150398.936667 PFOSPerfluorooctane sulfonic acidC8HF17SO3 1763-23-13031864498.930289 6:2 FTS6:2 fluorotelomer sulfonateC8H5F13SO3 27619-97-26067331426.967969Note: CASN, Chemical Abstracts Services Number; EPA, Environmental Protection Agency; GenX, hexafluoropropylene oxide dimer acid.aU.S. EPA CompTox Chemistry Dashboard ( https://comptox.epa.gov/dashboard).bDTXSID is a unique substance identifier used in the U.S. EPA CompTox Chemistry Dashboard (Williams et al. 2017).cIncludes carbon, oxygen, and sulfur atoms in the fluoroalkyl chain but does not include oxygen atoms in the anionic group (i.e., does not include O in carboxylic acid).Extracted ion chromatograms for 6:2 FTS (426.9679±5 ppm) yielded a doublet peak that was selected for follow-up MS/MS investigation with higher-energy C-trap dissociation (HCD) normalized collision energy of 45. Standards of 6:2 FTS (Schultz et al. 2004) and a polyfluoroalkyl ether carboxylic acid 2,2,3,3-tetrafluoro-3-((1,1,1,2,3,3-hexafluoro-3-(1,2,2,2-tetrafluoroethoxy)propan-2-yl)oxy)propanoic acid (known as Hydro-EVE) (Chemical Abstracts Services Number 773804-62-9) (U.S. EPA 2020) were prepared and analyzed by LC-HRMS/MS; annotated MS/MS spectra were compared with spectra collected from 10 serum samples randomly selected from our Wilmington cohort samples.Calibration standards ranging in concentration from 0.1 ng/mL to 25 ng/mL were prepared in newborn calf serum (ThermoFisher Scientific) by spiking PFAS standard stock solution into the serum; calibration standards were processed using the protocol for human serum samples described above. Compounds were quantified using a relative response ratio of the native standard and isotopically labeled internal standard; the [M-H]− or [M-H-CO2]− ions were used. Integration of PFAS isomers was consistent with U.S. EPA Method 537.1 (U.S. EPA 2018); that is, for compounds with branched and linear isomers (PFOA, PFOS, PFHxS), peaks for the branched and linear isomers were integrated together to report total concentration.Serum samples were run in batches of approximately 50 samples. Each batch contained in-house spiked newborn calf serum samples for continuing calibration checks. National Institutes of Standards and Technology (NIST) standard reference material (SRM) 1957 human serum was analyzed for calibration verification (acceptance criteria were ≤30% difference from consensus value). Mean concentrations of legacy PFAS (PFHpA, PFHxS, PFOA, PFOS, and PFNA) in SRM 1957 were within 10% difference of reference values determined by an interlaboratory analysis (see Table S2). We calculated the precision between replicate analyses by taking the difference divided by the average. Intrarun replicate analysis precision for duplicate analyses was less than 30% for most PFAS (see Table S3). As expected, lower replicate precision was observed at lower concentrations.The study sera were run in batches across eight analytical runs. Each analyte was assigned a batch-specific method reporting limit (MRL) defined as the first point of the standard curve for which the regression equation yielded a calculated value within 30% of the true value. For analytes with significant background signal in calf serum blanks, the MRL was designated as three times the maximum response in newborn calf serum blanks (i.e., in the 0-ng/mL standard), if higher than the MRL from the calibration curve. Higher instrument background levels for PFPeA, PFO2HxA, and GenX were observed on some analytical runs and resulted in higher batch-specific MRLs for those PFAS (see Table S4). In addition, the mass spectrometer had a high background response for the mass corresponding to PFMOAA, making it difficult to distinguish PFMOAA standards. We prioritized the method development for PFAS with longer alkyl (ether) chain length (e.g., PFO5DoA), which we suspected were more likely to be detected in blood (Ng and Hungerbühler 2014). Thus, we moved forward without measuring samples for PFMOAA.Statistical MethodsTo calculate summary statistics, we used the first blood sample collected from each participant (i.e., the blood sample collected when the participant was enrolled; that is, the November 2017 sample for most participants and the May 2018 sample for new enrollees in May). We present results for PFAS detected in 60% or more of 344 serum samples. For samples analyzed in duplicate, average values were used in the analyses. Sample results below the MRL were assigned a fill value of the MRL divided by the square root of 2 (Calafat et al. 2007; Daly et al. 2018). However, when we summed the mass concentration of all detectable PFAS to determine total PFAS in serum, we added 0 to the total for PFAS that were below the MRL so that we did not bias the sum upward because of multiple nondetected chemicals. We assessed correlation of PFAS serum concentrations using Spearman correlation coefficients; values greater than or equal to 0.70 were considered highly correlated.To compare differences between participants served with treated Cape Fear River water or another drinking water source, we used a Wilcoxon rank sum test. Two study participants who were enrolled in the early stages of the recruitment effort and who shared the same residence did not meet the study eligibility criterion of residing in the CFPUA service area. Their residence, however, was in Wilmington, and their drinking water source was not the Cape Fear River. Therefore, we included these two participants as part of the group with drinking water not sourced from the Cape Fear River.For participants who provided repeat samples, we calculated percentage change over time using serum PFAS concentrations in November 2017 and May 2018. Percentage change was calculated as ConcentrationNovember 2017−ConcentrationMay 2018ConcentrationNovember 2017×100% [1] We also used a Wilcoxon test for paired samples to evaluate differences in serum PFAS concentrations between November 2017 and May 2018. All statistical analyses were conducted in R (version 3.5.1; R Development Core Team). The significance level for all statistical analyses was p<0.05.Comparison DataTo determine whether fluoroethers were detectable in people living remote from the fluorochemical manufacturing site, we analyzed 20 stored serum samples collected in 2008–2009 from 30- to 44-y-old women participating in an unrelated research study, and living in the Raleigh, Durham, and Chapel Hill, North Carolina, area (Crawford et al. 2017) (Figure 1).ResultsStudy PopulationIn November 2017 and May 2018, we enrolled 344 participants, including 289 adults and 55 children; 310 enrolled in November 2017 and 34 enrolled in May 2018. We collected repeat blood samples from 44 participants (Table 2, Figure 2). Participants ranged in age from 6 to 86 y, with a median age of 50 y. The average years lived in the lower Cape Fear Region was 20 y [standard deviation (SD): 16 y], and 72% of participants reported residing in the region for >10y. In 75 of the 231 participating households (32%), at least 2 household members participated in the study. Most participants (97%) had drinking water sourced from the lower Cape Fear River, but 9 participants had another drinking water source.Table 2 Demographic characteristics of the 344 Wilmington, North Carolina, GenX exposure study participants.Table 2 has four columns, namely, Characteristic, November 2017 (n equals 310) (n, percentage), November 2017 Resampled May 2018 (n equals 44) (n, percentage), and May 2018 (n equals 34) (n, percentage).CharacteristicNovember 2017 (n=310) [n (%)]November 2017 (resampled May 2018) (n=44) [n (%)]May 2018 (n=34) [n (%)]Adult/child Adult (≥18y)256 (82.6)42 (95.5)33 (97.1) Child54 (17.4)2 (4.6)1 (2.94)Age group (y)a 6–1754 (17.5)2 (4.6)1 (3.1) 18–2912 (3.9)1 (2.3)2 (6.3) 30–3937 (12.0)4 (9.1)2 (6.3) 40–4957 (18.4)10 (22.7)2 (6.3) 50–5951 (16.5)9 (20.5)4 (12.5) 60–6962 (20.1)9 (20.5)13 (40.6) 70–8636 (11.7)9 (20.5)8 (25.0)Gender Female189 (61.0)28 (63.6)27 (79.4) Male120 (38.7)16 (36.4)7 (20.6) Transgender1 (0.3)00Race/ethnicityb Black, non–Hispanic8 (2.6)027 (79.4) Hispanic, regardless of race33 (10.7)3 (7.0)0 White, non–Hispanic261 (84.7)40 (93.0)4 (11.8) Otherc6 (2.0)03 Spanish speaker17 (5.5)00Residence in lower Cape Fear Region (y)d 1–988 (28.5)10 (22.7)6 (18.8) 10–19112 (36.3)18 (40.9)7 (21.9) 20–3976 (24.6)6 (13.6)6 (18.8) 40–4916 (5.2)5 (11.4)3 (9.4) 50–7317 (5.5)5 (11.4)10 (31.3)Drinking water sourcee CFPUA groundwater5 (1.6)1 (2.3)2 (5.9) CFPUA Cape Fear River301 (97.7)42 (97.7)32 (94.1) Not served by CFPUA2 (0.7)00Number of households2013530Participants per household 1130 (64.7)28 (80.0)26 (86.7) 246 (22.9)6 (17.4)4 (13.3) 312 (6.0)00 413 (6.5)1 (2.9)0Note: CFPUA, Cape Fear Public Utility Authority; GenX, hexafluoropropylene oxide dimer acid.aMissing age for three participants.bMissing race/ethnicity for two participants.cOther includes mixed-race individuals Native American/Pacific Islander, black or African American and Native American/Pacific Islander and white and other, Native American/Pacific Islander and white. May 2018: Other includes: American Indian/Alaska Native and Black or African American, black or African American and Native American/Pacific Islander and white, black or African American and white.dMissing years lived in lower Cape Fear River Region for 1 participant for the November 2017/May 2018 repeaters and 2 participants for the May 201 DA - 2020/7// PY - 2020/7// DO - 10.1289/EHP6837 VL - 128 IS - 7 SP - SN - 1552-9924 ER - TY - JOUR TI - Past and Present Design Practices and Uncertainty in Climate Projections are Challenges for Designing Infrastructure to Future Conditions AU - Underwood, B. Shane AU - Mascaro, Giuseppe AU - Chester, Mikhail V AU - Fraser, Andrew AU - Lopez-Cantu, Tania AU - Samaras, Constantine T2 - JOURNAL OF INFRASTRUCTURE SYSTEMS AB - Designing infrastructure for a changing climate remains a major challenge for engineers. In popular discourse a narrative has emerged that infrastructures are likely underdesigned for the future. Weather-related hazards are directly embedded in the infrastructure design process. Yet the codes and standards that engineers use for this risk analysis have been changing for decades, sometimes increasing and other times decreasing design values. Further complicating the issue is that climate projections show increasing or decreasing intensities depending on the hazard and region. Thus, it is not clear that infrastructure is universally underdesigned. Here, analyses are developed at both regional and national scales using precipitation and roadway drainage systems to answer this question. First, it is shown that modeling uncertainty can pose challenges for using future projections to update region-specific standards. Second, the results show that depending on the historical design conditions and the direction of projections, roadway drainage infrastructures may be designed appropriately in some regions while in others they are possibly underdesigned. Given these uncertainties, the authors believe that there is a need for alternative design paradigms, and these needs are discussed. DA - 2020/9// PY - 2020/9// DO - 10.1061/(ASCE)IS.1943-555X.0000567 VL - 26 IS - 3 SP - SN - 1943-555X KW - Climate change KW - Infrastructure KW - Resilience KW - Failure KW - Uncertainty ER - TY - JOUR TI - Retrieval of the saturated hydraulic conductivity of cement-based materials using electrical capacitance tomography AU - Voss, Antti AU - Pour-Ghaz, Mohammad AU - Vauhkonen, Marko AU - Seppanen, Aku T2 - CEMENT & CONCRETE COMPOSITES AB - Moisture transport properties have an important part in the durability of cement-based materials, because water plays a major role in the majority of degradation mechanisms and can carry other agents that are detrimental. One of the key transport properties is the permeability, or saturated hydraulic conductivity (SHC), which is a function of porosity, pore size distribution, and pore connectivity. Therefore, information on the SHC is very useful in predicting the durability; however measuring SHC is often difficult due to required experimental setup and the low SHC of cement-based materials. In this paper, we propose an electrical capacitance tomography (ECT) -based approach to estimate the SHC of cement-based materials. The proposed technique is applied to capillary absorption experiments, where specimens are imaged with ECT during water absorption, and the time-series of ECT reconstructions are used for tracing the water front propagation. The water front data, in turn, is used for estimating the SHC of the material. Here, we make a simplifying approximation for the moisture ingress and use (a 1D) sharp front model for estimating the SHC from the ECT-based data. The proposed SHC estimation scheme is tested both numerically and experimentally. The results of the numerical studies support the feasibility of the SHC retrieval both in ideal cases of 1D moisture flow and also in more realistic cases where the flows are not 1D. In the experimental part, the ECT-based estimates for the SHCs of mortars are in good agreement with the values determined using the falling-head method measured independently. DA - 2020/9// PY - 2020/9// DO - 10.1016/j.cemconcomp.2020.103639 VL - 112 SP - SN - 1873-393X KW - Cement-based materials KW - Mortar KW - Transport properties KW - Saturated hydraulic conductivity KW - Electrical capacitance tomography KW - Unsaturated flow ER - TY - JOUR TI - Implementation of the AASHTO M 332 Specification: A Case Study AU - Gundla, Akshay AU - Salim, Ramadan AU - Shane Underwood, B. AU - Kaloush, Kamil E. T2 - TRANSPORTATION RESEARCH RECORD AB - Over the past 20 years, changes in asphalt binders, the widespread adoption of polymer modified asphalts, and the need to bump asphalt binder grades to consider traffic conditions have exposed the gaps in the AASHTO M 320 specification, and subsequently led to the AASHTO M 332 specification. The State of Arizona initiated an experimental study to explore the possibility of adopting AASHTO M 332 into its binder specifications. In this paper, the specific challenges, technical implications of some key differences in the current Arizona standard compared with the AASHTO M 332 standard, and the approach taken to overcome the differences are explored and documented. Some of the key issues include the shortcomings of the J nr difference parameter, uncertainty of the pressurized aging vessel (PAV) temperature to be used, effect on the intermediate temperature parameter, |G*|sin δ, and the prospective distribution of asphalt binder grades if the new specification is adopted. Overall, the AASHTO M 332 specification is promising for the State of Arizona with minor changes recommended to prevent changes in binder formulations and influx of asphalt binders inferior to those currently available. DA - 2020/9// PY - 2020/9// DO - 10.1177/0361198120933266 VL - 2674 IS - 9 SP - 959-971 SN - 2169-4052 ER - TY - JOUR TI - Temporal variation of power production via reverse electrodialysis using coastal North Carolina waters and its correlation to temperature and conductivity AU - Hossen, Elvin H. AU - Gobetz, Zoe E. AU - Kingsbury, Ryan S. AU - Liu, Fei AU - Palko, Hannah C. AU - Dubbs, Lindsay L. AU - Coronell, Orlando AU - Call, Douglas F. T2 - DESALINATION AB - Global estimates of electricity generation from coastal salinity gradient energy resources rely on the underlying assumption that these gradients are spatially and temporally stable. Refining these estimates requires a better understanding of coastal variations in water properties and their impact on power production. This study investigated power output in reverse electrodialysis (RED) cells by coupling seawater samples collected from three different sites along coastal North Carolina at five different sampling dates between 2016 and 2017 with wastewater effluent from a wastewater treatment facility as the dilute solution. We found that power density did not vary substantially across the sampling dates except for one notable drop in power for a sample collected during an approaching hurricane. For all sites, power output peaked during the summer season. Using our experimental results, we developed a semi-empirical predictive model of RED power output as a function of temperature and conductivity. The model was able to predict power density within approximately 20% of the experimental power densities for the seawater samples used in this study and others in the literature. Combining our modeling approach with temporal conductivity and temperature data may help identify promising sites for coastal salinity gradient energy installations. DA - 2020/10/1/ PY - 2020/10/1/ DO - 10.1016/j.desal.2020.114562 VL - 491 SP - SN - 1873-4464 KW - Salinity gradient energy KW - Reverse electrodialysis KW - Temporal variation KW - Predictive model ER - TY - JOUR TI - Reducing fat, oil, and grease (FOG) deposits formation and adhesion on sewer collection system structures through the use of fly ash replaced cement-based materials AU - Kusum, Samrin A. AU - Pour-Ghaz, Mohammad AU - Ducoste, Joel J. T2 - Water Research AB - The accumulation of fat, oil, and grease (FOG) deposits in sewer pipes reduces their conveyance and results in Sanitary Sewer Overflows (SSOs). Previous research has shown that concrete used in sewer lines is a significant source for calcium ion, which participates in the FOG deposit formation mechanism. However, no research has been conducted to understand the effect of calcium leaching from cement on FOG deposits formation and adhesion. This study quantifies the reduction in FOG deposit formation when Fly Ash (FA), a Supplementary Cementitious Material (SCM), is used to replace cement in the production of High Volume Fly Ash (HVFA) concrete materials. Results show that after 90 days of leaching test under controlled pH conditions, 75% and 86% reduction in calcium release were achieved from 50% and 75% FA replacement, respectively. After 30 days of FOG deposits formation tests on HVFA samples, 58% and 81% reduction in FOG deposit formation was found for 50% and 75% FA replacement, respectively. FTIR analyses of FOG deposits formed on concrete samples without FA replacement exhibited high calcium soap content (48%), while, FOG deposit formed on HVFA concrete materials showed low calcium soap percentage (22~29%). Furthermore, FTIR analyses report the first spatial variation found in FOG deposits that includes a surface layer of hard FOG deposits with high calcium soap absorbance and an outer layer of soft FOG deposits consisting of a low calcium absorbance. FTIR analyses revealed that the FOG deposit formation mechanism is affected by the availability of calcium and pH near the concrete surface. Finally, HVFA concrete materials were tested for compressive strength and durability against microbially induced concrete corrosion (MICC). After 180 days of sealed curing, HVFA concrete exhibited adequate compressive strength necessary for the sewer line construction and 50% FA replacement revealed satisfactory durability against MICC. DA - 2020/11// PY - 2020/11// DO - 10.1016/j.watres.2020.116304 VL - 186 SP - 116304 J2 - Water Research LA - en OP - SN - 0043-1354 UR - http://dx.doi.org/10.1016/j.watres.2020.116304 DB - Crossref ER - TY - JOUR TI - Guidelines for Robust Adaptation to Environmental Regulations in Infrastructure Projects AU - Chowdhury, Sudipta AU - Zhu, Jin AU - Rasoulkhani, Kambiz AU - Mostafavi, Ali AU - Jaselskis, Edward AU - Stoa, Ryan AU - Li, Qingchun AU - Banerjee, Siddharth AU - Alsharef, Abdullah AU - Brannen, Laura T2 - JOURNAL OF CONSTRUCTION ENGINEERING AND MANAGEMENT AB - Environmental regulations can greatly affect the operation of new and existing infrastructure projects. In fact, the economic performance of infrastructure projects is closely related to environmental regulations whose landscape is extremely dynamic. To assist infrastructure project sectors in better coping with environmental regulatory changes, this study proposes guidelines for the robust adaptation to environmental regulations through information collected from an exploratory research process. As part of these guidelines, a process map model was developed that details the different stages in the environmental regulation development process, including prerulemaking, proposed rule development and publication, commenting period, final rule development and publication, and post-promulgation. Five adaptation subprocesses (i.e., regulatory horizon scanning, stakeholder engagement, risk and opportunity assessment, response strategy development, and compliance implementation) are examined to help regulated entities better adapt to regulatory changes across different regulatory stages. This information has the potential to provide companies with a structured stage-by-stage approach for dealing with uncertainties arising from environmental regulation changes. DA - 2020/// PY - 2020/// DO - 10.1061/(ASCE)CO.1943-7862.0001908 VL - 146 IS - 10 SP - 04020121 UR - https://doi.org/10.1061/(ASCE)CO.1943-7862.0001908 ER - TY - JOUR TI - Application of low-cost fine particulate mass monitors to convert satellite aerosol optical depth to surface concentrations in North America and Africa AU - Malings, Carl AU - Westervelt, Daniel M. AU - Hauryliuk, Aliaksei AU - Presto, Albert A. AU - Grieshop, Andrew AU - Bittner, Ashley AU - Beekmann, Matthias AU - Subramanian, R. T2 - ATMOSPHERIC MEASUREMENT TECHNIQUES AB - Abstract. Low-cost particulate mass sensors provide opportunities to assess air quality at unprecedented spatial and temporal resolutions. Established traditional monitoring networks have limited spatial resolution and are simply absent in many major cities across sub-Saharan Africa (SSA). Satellites provide snapshots of regional air pollution but require ground-truthing. Low-cost monitors can supplement and extend data coverage from these sources worldwide, providing a better overall air quality picture. We investigate the utility of such a multi-source data integration approach using two case studies. First, in Pittsburgh, Pennsylvania, both traditional monitoring and dense low-cost sensor networks are compared with satellite aerosol optical depth (AOD) data from NASA's MODIS system, and a linear conversion factor is developed to convert AOD to surface fine particulate matter mass concentration (as PM2.5). With 10 or more ground monitors in Pittsburgh, there is a 2-fold reduction in surface PM2.5 estimation mean absolute error compared to using only a single ground monitor. Second, we assess the ability of combined regional-scale satellite retrievals and local-scale low-cost sensor measurements to improve surface PM2.5 estimation at several urban sites in SSA. In Rwanda, we find that combining local ground monitoring information with satellite data provides a 40 % improvement in surface PM2.5 estimation accuracy with respect to using low-cost ground monitoring data alone. A linear AOD-to-surface-PM2.5 conversion factor developed in Kigali, Rwanda, did not generalize well to other parts of SSA and varied seasonally for the same location, emphasizing the need for ongoing and localized ground-based monitoring, which can be facilitated by low-cost sensors. Overall, we find that combining ground-based low-cost sensor and satellite data, even without including additional meteorological or land use information, can improve and expand spatiotemporal air quality data coverage, especially in data-sparse regions. DA - 2020/7/17/ PY - 2020/7/17/ DO - 10.5194/amt-13-3873-2020 VL - 13 IS - 7 SP - 3873-3892 SN - 1867-8548 UR - https://doi.org/10.5194/amt-13-3873-2020 ER - TY - JOUR TI - Exploring Instrumentation and Sensor Technologies for Highway Design and Construction Projects AU - Harper, Christofer M. AU - Tran, Daniel AU - Jaselskis, Edward T2 - TRANSPORTATION RESEARCH RECORD AB - With the infusion of emerging technologies into highway construction practices, state departments of transportation (DOTs) can make better informed decisions that positively influence cost, schedule, quality, and safety. DOTs are increasingly using instrumentation and sensor technologies for delivering highway projects across the U.S.A. Instrumentation devices and sensors include such technologies as remote sensing, real-time kinematics, global positioning systems, digital handheld devices, ground penetrating radar, and intelligent compaction/thermal profiling. These technologies are becoming commonplace in highway construction because of their capabilities to improve the construction process by making activities more efficient and more productive. However, the practices in using instrumentation and sensor technologies for highway construction vary among state DOTs. Therefore, this study investigates how DOTs employ the use of instrumentation and sensor technologies for highway construction. This study engaged a research methodology that included an extensive literature review, survey questionnaire, and case studies of state DOTs. Results show that 31 state DOTs use instrumentation and sensor technologies for monitoring work progress, conducting quality control and quality assurance, performing construction inspections, identifying optimal conditions and recording the placement of work, and locating utilities. The main barriers to using instrumentation and sensor technologies include analyzing the large amount of data, verifying the accuracy of the data, ensuring staff have the skills and knowledge to use the technologies efficiently, and assisting smaller contractors to gain the knowledge to use these technologies. The findings from this study provide recommendations and strategies for DOTs to implement instrumentation and sensor technologies effectively for highway construction. DA - 2020/9// PY - 2020/9// DO - 10.1177/0361198120930718 VL - 2674 IS - 9 SP - 593-604 SN - 2169-4052 ER - TY - JOUR TI - Developing hazard recognition skill among the next-generation of construction professionals AU - Albert, Alex AU - Jeelani, Idris AU - Han, Kevin T2 - CONSTRUCTION MANAGEMENT AND ECONOMICS AB - Globally, a large number of safety hazards remain unrecognised in construction workplaces. These unrecognised safety hazards are also likely to remain unmanaged and can potentially cascade into unexpected safety incidents. Therefore, the development of hazards recognition skill – particularly among the next-generation of construction professionals – is vital for injury prevention and safe work-operations. To foster the development of such skill, the current investigation examined the effect of administering a hazard recognition intervention to students seeking to enter the construction workforce. First, prior to introducing the intervention, the pre-intervention hazard recognition skill of the participating students was measured. Next, the intervention that included a number of programme elements was introduced. The programme elements included (1) visual cues to promote systematic hazard recognition, (2) personalised hazard recognition performance feedback, (3) visual demonstration of common hazard recognition search weaknesses, and (4) diagnosis of hazard search weaknesses using metacognitive prompts. Finally, the post-intervention skill demonstrated by the student participants was measured and compared against their pre-intervention performance. The results suggest that the intervention was effective in improving the hazard recognition skill demonstrated by the next-generation of construction professionals. The observed effect was particularly prominent among those that demonstrated relatively lower levels of skill in the pre-intervention phase. The research also unveiled particular impediments to hazards recognition that the participants experienced. DA - 2020/11/1/ PY - 2020/11/1/ DO - 10.1080/01446193.2020.1797133 VL - 38 IS - 11 SP - 1024-1039 SN - 1466-433X KW - Construction safety KW - safety management KW - hazard identification KW - hazard recognition KW - Injury prevention ER - TY - JOUR TI - Effect of Speed Bumps on Pavement Condition AU - Goenaga, Boris AU - Underwood, Shane AU - Fuentes, Luis T2 - Transportation Research Record AB - Speed bumps are efficient traffic calming devices that allow transport authorities to control vehicle speeds and improve safety in specific locations. Though frequently used in residential areas, they have become increasing prevalent in other higher volume roadways (particularly in developing countries), because of their effectiveness, low-cost of implementation, and easy installation process. However, in these countries there is no proper technical guidance for speed bump design and implementation, which is why one can often find these devices placed on an arterial highway or on roads where the proportion of trucks is high. The most important consequence of placing a speed bump on a road with large numbers of trucks is that the pavement deterioration process will accelerate as a result of the induced vibrations and bouncing of a truck’s suspension. In this paper the relationship between the bump geometry—length and height—and the dynamic load transmitted to the pavement is studied. A full truck model has been used to simulate the vehicle dynamics while passing over the bump, to estimate the demand imposed over the pavement. Damage was calculated for each simulation scenario using a combination of linear-elastic analysis and empirical damage functions. The geometry that leads to less damage is the circular, with a minimum length of two meters and a maximum height of ten centimeters. DA - 2020/// PY - 2020/// DO - 10.1177/0361198120927005 VL - 2674 IS - 9 SP - 66-82 ER - TY - JOUR TI - Application of packed bed reactor theory and Bayesian inference to upweller culture of juvenile oysters AU - Campbell, Matthew D. AU - Hall, Steven G. AU - Obenour, Daniel R. T2 - AQUACULTURAL ENGINEERING AB - The use of upweller culture units in bivalve nurseries is widely practiced as a technique that enhances the ability to rear large quantities in a semi-controlled environment. However, guidance has varied for optimal flow rates, and thus there is a need to develop a more mechanistic assessment. The application of packed bed reactor theory, including axial diffusion models, would improve optimization of these culture methods. The following paper presents a series of controlled experiments to determine the hydrodynamic properties of a packed bed of oysters. The data gained from these experiments was used to develop mechanistic models calibrated through Bayesian inference. Specifically, the Ergun equation and the axial diffusion model were used to predict the experimental data. The Ergun equation was able to predict the hydrodynamic equivalent diameter distribution of oyster shells (μ = 3.18 mm, σ = 0.74 mm). This oyster shell diameter and void ratio distribution gained through the Ergun equation were used in the relationship of axial diffusion and superficial velocity. The mean axial diffusion coefficient in the oyster bed was estimated 1.65 × 104 m2/s at 0.01 m/s and 7.26 × 104 m2/s at 0.08 m/s. The use of Bayesian inference allows for greater understanding of the credibility of individual parameter distributions (i.e., rates and physical attributes) within these mechanistic formulations. This work establishes a baseline methodology to systematically evaluate and optimize bivalve upweller culture systems. DA - 2020/8// PY - 2020/8// DO - 10.1016/j.aquaeng.2020.102098 VL - 90 SP - SN - 1873-5614 KW - Oysters KW - Upweller KW - Packed bed KW - Axial diffusion KW - Bayesian inference ER - TY - JOUR TI - Wind and tide effects on the Choctawhatchee Bay plume and implications for surface transport at Destin Inlet T2 - Regional Studies in Marine Science AB - Multiple river-dominated estuaries line the northern Gulf coast and introduce substantial density variations. Their plumes have been shown to be highly sensitive to wind and tide effects, but in studies with limited observations and idealized wind forcing. This study explores these effects with a dynamic model that can represent the full behavior from river through estuary to shelf, and for a period with extensive observations. The inner shelf adjacent to Choctawhatchee Bay, a micro tidal estuary situated along the Florida Panhandle, is subject to buoyant, brackish outflows during the ebb-phase of the tidal cycle. In December 2013, experiments were performed in this region to study mechanisms that influence near-shore surface transport. Satellite imagery showed a visible brackish surface plume at Destin during low tide. The goal of the present study is to quantify variability in the plume signature due to changes in tidal and wind forcing. Density-driven flows near Destin Inlet are modeled with the recently-enhanced, three-dimensional, baroclinic capabilities of the ADvanced CIRCulation (ADCIRC) model. Modeled tides, salinities and plume signature are validated against in-situ observations and satellite imagery. Model results reveal substantial changes in the length, width and orientation of the plume as the wind direction varied on consecutive days due to winter cold fronts. During a period of near-constant winds and variability in tidal amplitude, the model predicted a larger plume during spring tides than during neap conditions. Coriolis effects on the plume are minimized due to its small scale nature. Therefore, when the wind forcing is weak, the plume signature spreads radially from the inlet with slight preference to the down-shelf. The Choctawhatchee Bay plume is representative of other small-scale plumes formed in river-dominated and micro-tidal environments, and this work demonstrates the sensitivity of these plumes to changing environmental conditions. DA - 2020/3// PY - 2020/3// DO - 10.1016/j.rsma.2020.101131 UR - http://dx.doi.org/10.1016/j.rsma.2020.101131 KW - ADCIRC KW - Plume dynamics KW - Cold fronts KW - Florida Panhandle KW - SCOPE KW - CARTHE ER - TY - JOUR TI - Fat, oil, and grease (FOG) deposits yield higher methane than FOG in anaerobic co-digestion with waste activated sludge AU - Hao, J. T2 - Journal of Environmental Management AB - The formation of fat, oil, and grease (FOG) deposits in sewers is a global challenge for the maintenance of sewer collection systems. Tons of FOG deposits (FDs) are removed from sewer systems every year and present an opportunity for increased methane production via anaerobic co-digestion with waste activated sludge (WAS) at water resource recovery facilities with existing anaerobic digesters. We hypothesized that FDs have higher biomethane potential than that of FOG (e.g., FOG collected in grease interceptors), because of the reduction of inhibition of long chain fatty acids due to saponification. In this study, substantially enhanced methane production was found in anaerobic co-digestion of WAS with FDs within the substrate to inoculum (S/I) ratio range of 0.25–1.2, and the maximum ultimate methane production (685.7 ± 24.1 mL/gVSadded, at S/I = 0.5) was 4.0 times higher than in the control (with WAS only) after 42 days of incubation. Although the lag phase period was longer in FD co-digestion (S/I = 0.5) than in FOG co-digestion (S/I = 0.5) under the same organic loading (gVS) and two times the COD loading, the daily methane production rate became higher after Day 15 in FD co-digestion. Significantly higher cumulative methane production (10.2%, p < 0.05) was obtained in FD co-digestion than in FOG co-digestion after 42-days. Microbial community analysis revealed higher levels of Geobacter in FD co-digestion, possibly suggesting a role for direct interspecies electron transfer (DIET) between Methanosaeta and Geobacter. This work provides fundamental insights supporting anaerobic co-digestion of FDs with WAS, demonstrating the advantages of FDs compared to FOG as co-substrate for enhanced biomethane recovery. DA - 2020/8// PY - 2020/8// DO - 10.1016/j.jenvman.2020.110708 VL - 268 SP - 110708 UR - http://dx.doi.org/10.1016/j.jenvman.2020.110708 KW - FOG deposits KW - Anaerobic co-digestion KW - Methane production KW - Microbial community KW - DIET ER - TY - JOUR TI - Wastewater-Based Epidemiology: Global Collaborative to Maximize Contributions in the Fight Against COVID-19 AU - Bivins, Aaron AU - North, Devin AU - Ahmad, Arslan AU - Ahmed, Warish AU - Alm, Eric AU - Been, Frederic AU - Bhattacharya, Prosun AU - Bijlsma, Lubertus AU - Boehm, Alexandria B. AU - Brown, Joe AU - Buttiglieri, Gianluigi AU - Calabro, Vincenza AU - Carducci, Annalaura AU - Castiglioni, Sara AU - Gurol, Zeynep Cetecioglu AU - Chakraborty, Sudip AU - Costa, Federico AU - Curcio, Stefano AU - Reyes, Francis L. AU - Vela, Jeseth Delgado AU - Farkas, Kata AU - Fernandez-Casi, Xavier AU - Gerba, Charles AU - Gerrity, Daniel AU - Girones, Rosina AU - Gonzalez, Raul AU - Haramoto, Eiji AU - Harris, Angela AU - Holden, Patricia A. AU - Islam, Md. Tahmidul AU - Jones, Davey L. AU - Kasprzyk-Hordern, Barbara AU - Kitajima, Masaaki AU - Kotlarz, Nadine AU - Kumar, Manish AU - Kuroda, Keisuke AU - Rosa, Giuseppina La AU - Malpei, Francesca AU - Mautus, Mariana AU - McLellan, Sandra L. AU - Medema, Gertjan AU - Meschke, John Scott AU - Mueller, Jochen AU - Newton, Ryan J. AU - Nilsson, David AU - Noble, Rachel T. AU - Nuijs, Alexander AU - Peccia, Jordan AU - Perkins, T. Alex AU - Pickering, Amy J. AU - Rose, Joan AU - Sanchez, Gloria AU - Smith, Adam AU - Stadler, Lauren AU - Stauber, Christine AU - Thomas, Kevin AU - Voorn, Tom AU - Wigginton, Krista AU - Zhu, Kevin AU - Bibby, Kyle T2 - Environmental Science & Technology AB - ADVERTISEMENT RETURN TO ISSUEPREVViewpointNEXTWastewater-Based Epidemiology: Global Collaborative to Maximize Contributions in the Fight Against COVID-19Aaron BivinsAaron BivinsDepartment of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, Indiana 46556, United StatesMore by Aaron Bivins, Devin NorthDevin NorthDepartment of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, Indiana 46556, United StatesMore by Devin North, Arslan AhmadArslan AhmadDepartment of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 10B, SE-10044 Stockholm, SwedenKWR Water Research Institute, Groningenhaven 7 3433 PE Nieuwegein, The NetherlandsMore by Arslan Ahmad, Warish AhmedWarish AhmedCSIRO Land and Water, Ecosciences Precinct, 41 Boggo Road, Dutton Park, Queensland 4102, AustraliaMore by Warish Ahmed, Eric AlmEric AlmDepartment of Biological Engineering, Massachusetts Institute of Technology, 21 Ames St, Cambridge, Massachusetts 02142, United StatesMore by Eric Alm, Frederic BeenFrederic BeenKWR Water Research Institute, Water Quality and Heath, Groningenhaven 7 3433 PE Nieuwegein, The NetherlandsMore by Frederic Been, Prosun BhattacharyaProsun BhattacharyaDepartment of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 10B, SE-10044 Stockholm, SwedenKWR Water Research Institute, Groningenhaven 7 3433 PE Nieuwegein, The NetherlandsMore by Prosun Bhattacharyahttp://orcid.org/0000-0003-4350-9950, Lubertus BijlsmaLubertus BijlsmaAnalytical Chemistry in Public Health and the Environment, University Jaume I, Av. Vicent Sos Baynat, s/n 12071 Castellón de la Plana, SpainMore by Lubertus Bijlsmahttp://orcid.org/0000-0001-7005-8775, Alexandria B. BoehmAlexandria B. BoehmDepartment of Civil and Environmental Engineering, Stanford University, 473 Via Ortega, Stanford, California 94305, United StatesMore by Alexandria B. Boehm, Joe BrownJoe BrownSchool of Civil and Environmental Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30332, United StatesMore by Joe Brownhttp://orcid.org/0000-0002-5200-4148, Gianluigi ButtiglieriGianluigi ButtiglieriCatalan Institute for Water Research (ICRA), Emili Grahit 101, E-17003 Girona, SpainMore by Gianluigi Buttiglieri, Vincenza CalabroVincenza CalabroLaboratory of Transport Phenomena & Biotechnology, Department of Computer Engineering, Modeling, Electronics and Systems, University of Calabria, Via P. Bucci, Cubo 42/a 87036 Rende, Cosenza, ItalyMore by Vincenza Calabro, Annalaura CarducciAnnalaura CarducciDepartment of Biology, University of Pisa, Via Volta 4 bis, 13 56126 Pisa, ItalyMore by Annalaura Carducci, Sara CastiglioniSara CastiglioniDepartment of Environmental Health Sciences, Instituto di Richerche Farmacologiche Mario Negri IRCCS, Via Mario Negri, 2, 20156 Milan, ItalyMore by Sara Castiglioni, Zeynep Cetecioglu GurolZeynep Cetecioglu GurolDepartment of Chemical Engineering, KTH Royal Institute of Technology, Teknikringen 42, SE-11428 Stockholm, SwedenMore by Zeynep Cetecioglu Gurol, Sudip ChakrabortySudip ChakrabortyLaboratory of Transport Phenomena & Biotechnology, Department of Computer Engineering, Modeling, Electronics and Systems, University of Calabria, Via P. Bucci, Cubo 42/a 87036 Rende, Cosenza, ItalyMore by Sudip Chakraborty, Federico CostaFederico CostaInstituto de Saúde Coletiva, Universidade Federal da Bahia, Salvador, Bahia, Brazil. 40110-040More by Federico Costa, Stefano CurcioStefano CurcioLaboratory of Transport Phenomena & Biotechnology, Department of Computer Engineering, Modeling, Electronics and Systems, University of Calabria, Via P. Bucci, Cubo 42/a 87036 Rende, Cosenza, ItalyMore by Stefano Curcio, Francis L. de los Reyes IIIFrancis L. de los Reyes, IIIDepartment of Civil, Construction, and Environmental Engineering, North Carolina State University, 2501 Stinson Dr, Raleigh, North Carolina 27607, United StatesMore by Francis L. de los Reyes, IIIhttp://orcid.org/0000-0002-3593-0932, Jeseth Delgado VelaJeseth Delgado VelaDepartment of Civil and Environmental Engineering, Howard University, 2300 Sixth Street, NW #1026, Washington, D.C. 20059, United StatesMore by Jeseth Delgado Velahttp://orcid.org/0000-0001-6171-4400, Kata FarkasKata FarkasSchool of Ocean Sciences, Bangor University, Menai Bridge, Anglesey, LL59 5AB, U.K.More by Kata Farkas, Xavier Fernandez-CasiXavier Fernandez-CasiLaboratory of Environmental Chemistry, School of Architecture, Civil and Environmental Engineering (ENAC), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, SwitzerlandMore by Xavier Fernandez-Casi, Charles GerbaCharles GerbaDepartment of Environmental Science, University of Arizona, 2959 W Calle Agua Nueva, Tucson, Arizona 85745, United StatesMore by Charles Gerba, Daniel GerrityDaniel GerrityApplied Research and Development Center, Southern Nevada Water Authority, 100 S City Pkwy Suite 700, Las Vegas, Nevada 89106, United StatesMore by Daniel Gerrity, Rosina GironesRosina GironesDepartment of Genetics, Microbiology and Statistics, University of Barcelona, Diagonal, 643 08028 Barcelona, SpainMore by Rosina Girones, Raul GonzalezRaul GonzalezHampton Roads Sanitation District, 1434 Air Rail Ave, Virginia Beach, Virginia 23455, United StatesMore by Raul Gonzalezhttp://orcid.org/0000-0002-8115-7709, Eiji HaramotoEiji HaramotoInterdisciplinary Center for River Basin Environment, University of Yamanashi, 4-3-11 Takeda, Kofu, Yamanashi 400-8511, JapanMore by Eiji Haramotohttp://orcid.org/0000-0002-0126-0651, Angela HarrisAngela HarrisDepartment of Civil, Construction, and Environmental Engineering, North Carolina State University, 2501 Stinson Dr, Raleigh, North Carolina 27607, United StatesMore by Angela Harris, Patricia A. HoldenPatricia A. HoldenBren School of Environmental Science & Management, University of California, 3508 Bren Hall, Santa Barbara, California 93106, United StatesMore by Patricia A. Holdenhttp://orcid.org/0000-0002-6777-5359, Md. Tahmidul IslamMd. Tahmidul IslamDepartment of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 10B, SE-10044 Stockholm, SwedenMore by Md. Tahmidul Islam, Davey L. JonesDavey L. JonesSchool of Natural Sciences, Bangor University, Gwynedd, Wales LL57 2UW, United KingdomMore by Davey L. Jones, Barbara Kasprzyk-HordernBarbara Kasprzyk-HordernDepartment of Chemistry, University of Bath, Claverton Down Bath, BA2 7AY, United KingdomMore by Barbara Kasprzyk-Hordernhttp://orcid.org/0000-0002-6809-2875, Masaaki KitajimaMasaaki KitajimaDivision of Environmental Engineering, Hokkaido University, North 13 West 8, Kita-ku, Sapporo, Hokkaido 060-8628, JapanMore by Masaaki Kitajimahttp://orcid.org/0000-0002-8142-511X, Nadine KotlarzNadine KotlarzDepartment of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695, United StatesMore by Nadine Kotlarzhttp://orcid.org/0000-0002-7302-9176, Manish KumarManish KumarDiscipline of Earth Science, Indian Institute of Technology, Gandhinagar, Gujarat 382 355, IndiaMore by Manish Kumarhttp://orcid.org/0000-0002-3351-7298, Keisuke KurodaKeisuke KurodaDepartment of Environmental & Civil Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu-city, Toyama 9390398 JapanMore by Keisuke Kuroda, Giuseppina La RosaGiuseppina La RosaDepartment of Environment and Health, Italian National Institute of Health, Viale Regina Elena, 299, 00161, Roma RM, ItalyMore by Giuseppina La Rosa, Francesca MalpeiFrancesca MalpeiDipartimento di Ingegneria Civile e Ambientale, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milano MI, ItalyMore by Francesca Malpei, Mariana MautusMariana MautusBiobot Analytics, LLC, Somerville, Massachusetts 02143, United StatesMore by Mariana Mautushttp://orcid.org/0000-0002-2880-0339, Sandra L. McLellanSandra L. McLellanSchool of Freshwater Sciences, University of Wisconsin-Milwaukee, 600 E Greenfield Ave, Milwaukee, Wisconsin 53204, United StatesMore by Sandra L. McLellanhttp://orcid.org/0000-0003-3283-1151, Gertjan MedemaGertjan MedemaKWR Water Research Institute, Water Quality and Heath, Groningenhaven 7 3433 PE Nieuwegein, The NetherlandsDelft University of Technology, Stevinweg 1, 2628 CN Delft, The NetherlandsMichigan State University, Natural Resources, 1405 S Harrison Rd, East Lansing, Michigan 48823, United StatesMore by Gertjan Medemahttp://orcid.org/0000-0003-0475-6465, John Scott MeschkeJohn Scott MeschkeDept. Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Seattle Washington 98105-6099, United StatesMore by John Scott Meschke, Jochen MuellerJochen MuellerQueensland Alliance for Environmental Health Sciences (QAEHS), University of Queensland, 20 Cornwall Street, Brisbane, Queensland 4102 AustraliaMore by Jochen Mueller, Ryan J. NewtonRyan J. NewtonSchool of Freshwater Sciences, University of Wisconsin-Milwaukee, 600 E Greenfield Ave, Milwaukee, Wisconsin 53204, United StatesMore by Ryan J. Newtonhttp://orcid.org/0000-0001-8946-0035, David NilssonDavid NilssonDepartment of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 10B, SE-10044 Stockholm, SwedenMore by David Nilsson, Rachel T. NobleRachel T. NobleUNC Chapel Hill Institute of Marine Sciences, Morehead City, North Carolina 28557, United StatesMore by Rachel T. Noble, Alexander van NuijsAlexander van NuijsToxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, BelgiëMore by Alexander van Nuijs, Jordan PecciaJordan PecciaDepartment of Chemical and Environmental Engineering, Yale University, 17 Hillhouse Avenue, New Haven, Connecticut 06520-8292, United StatesMore by Jordan Pecciahttp://orcid.org/0000-0002-6482-2084, T. Alex PerkinsT. Alex PerkinsDepartment of Biological Sciences and Eck Institute for Global Health, University of Notre Dame, Notre Dame, Indiana 46556, United StatesMore by T. Alex Perkins, Amy J. PickeringAmy J. PickeringCivil and Environmental Engineering, Tufts University, Medford, Massachusetts 02155, United StatesMore by Amy J. Pickeringhttp://orcid.org/0000-0001-6193-2221, Joan RoseJoan RoseDepartment of Fisheries and Wildlife, Michigan State University, East Lansing, Michigan 48824, United StatesMore by Joan Rose, Gloria SanchezGloria SanchezInstitute of Agrochemistry and Food Technology (IATA-CSIC), Catedratico Agustin Escardino Benlloch, 7 46980 Paterna − Valencia, SpainMore by Gloria Sanchez, Adam SmithAdam SmithAstani Department of Civil and Environmental Engineering, University of Southern California, 3620 S Vermont Ave, Los Angeles, California 90089, United StatesMore by Adam Smithhttp://orcid.org/0000-0002-3964-7544, Lauren StadlerLauren StadlerDepartment of Civil and Environmental Engineering, Rice University, 6100 Main St, Houston, Texas 77005, United StatesMore by Lauren Stadlerhttp://orcid.org/0000-0001-7469-1981, Christine StauberChristine StauberSchool of Public Health, Georgia State University, 100 Piedmont Avenue, NE Atlanta, Georgia 30302, United StatesMore by Christine Stauber, Kevin ThomasKevin ThomasQueensland Alliance for Environmental Health Sciences (QAEHS), University of Queensland, 20 Cornwall Street, Brisbane, Queensland 4102 AustraliaMore by Kevin Thomashttp://orcid.org/0000-0002-2155-100X, Tom van der VoornTom van der VoornInstitute of Environmental Systems Research, University of Osnabrück, Barbarastr. 12, D49069, Osnabrück, GermanyMore by Tom van der Voorn, Krista WiggintonKrista WiggintonDepartment of Civil and Environmental Engineering, University of Michigan, 1351 Beal Avenue, EWRE 181 Ann Arbor, Michigan 48109-2125, United StatesMore by Krista Wiggintonhttp://orcid.org/0000-0001-6665-5112, Kevin ZhuKevin ZhuSchool of Civil and Environmental Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30332, United StatesMore by Kevin Zhu, and Kyle Bibby*Kyle BibbyDepartment of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, 156 Fitzpatrick Hall, Notre Dame, Indiana 46556, United States*Email: [email protected]More by Kyle Bibbyhttp://orcid.org/0000-0003-3142-6090Cite this: Environ. Sci. Technol. 2020, 54, 13, 7754–7757Publication Date (Web):June 12, 2020Publication History Received16 April 2020Published online12 June 2020Published inissue 7 July 2020https://doi.org/10.1021/acs.est.0c02388Copyright © 2020 American Chemical SocietyRequest reuse permissions This publication is Open Access under the license indicated. Learn MoreArticle Views26744Altmetric-Citations245LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (2 MB) Get e-AlertscloseSUBJECTS:COVID-19,Genetics,Immunology,Infectious diseases,SARS-CoV-2,Sewage,Wastewater Get e-Alerts DA - 2020/7/7/ PY - 2020/7/7/ DO - 10.1021/acs.est.0c02388 VL - 54 IS - 13 SP - 7754-7757 UR - http://dx.doi.org/10.1021/acs.est.0c02388 N1 - Adam Smith, Lauren Stadler, Christine Stauber, Kevin Thomas, Tom van der Voorn, Krista Wigginton, Kevin Zhu, Kyle Bibby. Wastewater-Based Epidemiology of COVID-19: Global Collaborative to Maximize Impact. Environmental Science and Technology. RN - Adam Smith, Lauren Stadler, Christine Stauber, Kevin Thomas, Tom van der Voorn, Krista Wigginton, Kevin Zhu, Kyle Bibby. Wastewater-Based Epidemiology of COVID-19: Global Collaborative to Maximize Impact. Environmental Science and Technology. ER - TY - JOUR TI - Quantification of Sources of Variability of Air Pollutant Exposure Concentrations Among Selected Transportation Microenvironments AU - Frey, H. Christopher AU - Gadre, Disha AU - Singh, Sanjam AU - Kumar, Prashant T2 - TRANSPORTATION RESEARCH RECORD AB - The National Research Council has identified the lack of sufficient microenvironmental air pollution exposure data as a significant barrier to quantification of human exposure to air pollution. Transportation microenvironments, including pedestrian, transit bus, car, and bicycle, can be associated with higher exposure concentrations than many other microenvironments. Data are lacking that provide a systematic basis for comparing exposure concentrations in these transportation modes that account for key sources of variability, such as time of day, season, and types of location along a route such as bus stops and intersections. The objectives of this work are: to quantify and compare particulate matter (PM 2.5 ), CO, and O 3 exposure concentrations in selected active and passive transportation microenvironments; and to quantify the effect of season, time of day, and location with respect to variability in transportation mode exposure concentrations. Measurements were made with an instrumented backpack and were repeated for multiple days in each season to account for the effect of inter-run variability. Results include mean trends, spatial variability, and contribution to variance. Pedestrian and cycle mode exposure concentrations were approximately similar to each other and were substantially higher than for bus and car cabins for both PM 2.5 and O 3 . Based on over 30 days of field measurements conducted over three seasons and for two times of day on weekdays, transportation mode and season were the largest contributors to variability in exposure for PM 2.5 and O 3 , whereas location type alone and in combination with transport mode helped explain variability in CO exposures. DA - 2020/9// PY - 2020/9// DO - 10.1177/0361198120929336 VL - 2674 IS - 9 SP - 395-411 SN - 2169-4052 ER - TY - JOUR TI - A skid resistance prediction model for an entire road network AU - Pérez-Acebo, Heriberto AU - Gonzalo-Orden, Hernán AU - Findley, Daniel J. AU - Rojí, Eduardo T2 - Construction and Building Materials AB - This article predicts the available minimum skid resistance in the road network of Biscay (Spain) with data collected in the summer season when friction values are at a minimum. Firstly, it was observed that pavement structure does not influence skid resistance. Therefore, roadway segments with available data about the surface layer of single or double carriageway roads were analyzed. Two models were developed: 1) short model with only the surface material, average annual daily traffic, and number of lanes (no pavement history required) and 2) a long model which adds the required Polished Stone Value to improve the prediction. These models can help road agencies to identify the roads where lower skid resistance values are more probable to be obtained to focus their attention and efforts. DA - 2020/11// PY - 2020/11// DO - 10.1016/j.conbuildmat.2020.120041 VL - 262 SP - 120041 UR - https://doi.org/10.1016/j.conbuildmat.2020.120041 KW - Skid resistance KW - Friction KW - Pavement performance model KW - Pavement deterioration KW - Pavement management system KW - Deterministic model KW - Deterioration model KW - Surface layer KW - Pavement management ER - TY - JOUR TI - PRAISE -HK: A personalized real-time air quality informatics system for citizen participation in exposure and health risk management AU - Che, Wenwe AU - Frey, H. Christopher AU - Fung, Jimmy C. H. AU - Ning, Zhi AU - Qu, Huamin AU - Lo, Hong Kam AU - Chen, Lei AU - Wong, Tze-Wai AU - Wong, Michelle K. M. AU - Lee, Ophelia C. W. AU - Carruthers, David AU - Cheung, Freeman AU - Chan, Jimmy W. M. AU - Yeung, David W. AU - Fung, Yik Him AU - Zhang, Xuguo AU - Stocker, Jenny AU - Hood, Christina AU - Hohenberger, Tilman Leo AU - Leung, King Wai AU - Louie, Phillip Y. K. AU - Li, Alison T. Y. AU - Sun, Li AU - Wei, Peng AU - Li, Zhiyuan AU - Zhang, Yumiao AU - Wang, Meilan AU - Shen, Qiaomu AU - Huang, Wei AU - Lee, Enoch AU - Patwary, Ashraf AU - Lei, Xiayu AU - Cheng, Steven AU - Hossain, Md Shakhaoat AU - Tang, Kimberly Tasha Jiayi AU - Lao, XiangQian AU - Leung, Rae AU - Chan, Denise AU - Li, Ying AU - Yuan, Zibing AU - Lau, Alexis K. H. T2 - SUSTAINABLE CITIES AND SOCIETY AB - Exposure to air pollutants causes a range of adverse health effects. These harmful effects occur whenever and wherever people come into direct contact with air pollution. Therefore, individual actions that reduce the frequency, duration, and severity of personal contact with air pollution can reduce health risks. We developed a system that empowers the public with personalized information on air quality and exposure health risk. This system, the Personalised Real-Time Air Quality Informatics System for Exposure – Hong Kong (PRAISE-HK, http://praise.ust.hk/), is embodied in an interactive mobile application. PRAISE-HK is based on real-time data on emissions, high resolution urban morphology, meteorology, physical and chemical processes affecting pollutant transport and transformations, extensive measurements of air pollution concentrations in typical locations such as homes, schools, offices, and transportation, and big data integration of sensor monitoring to accurately estimate current and short-term forecasted street-level air quality. The street-level air quality simulation has been validated against reference monitoring data. Ongoing and planned future enhancements to PRAISE-HK include prediction of personal exposure and health response. PRAISE-HK is an example of the use of collective intelligence in a smart city to engage citizens in learning about and managing their own exposure to air pollution. DA - 2020/3// PY - 2020/3// DO - 10.1016/j.scs.2019.101986 VL - 54 SP - SN - 2210-6715 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85078175966&partnerID=MN8TOARS KW - Air pollution KW - Personalized exposure KW - Individual health sensitivity KW - Citizen engagement ER - TY - JOUR TI - Evaluation of the Precision and Accuracy of Cycle-Average Light Duty Gasoline Vehicles Tailpipe Emission Rates Predicted by Modal Models AU - Wei, Tongchuan AU - Frey, H. Christopher T2 - TRANSPORTATION RESEARCH RECORD AB - A vehicle specific power (VSP) modal model and the MOtor Vehicle Emission Simulator (MOVES) Operating Mode (OpMode) model have been used to evaluate and quantify the fuel use and emission rates (FUERs) for on-road vehicles. These models bin second-by-second FUERs based on factors such as VSP, speed, and others. The validity of binning approaches depends on their precision and accuracy in predicting variability in cycle-average emission rates (CAERs). The objective is to quantify the precision and accuracy of the two modeling methods. Since 2008, North Carolina State University has used portable emission measurement systems to measure tailpipe emission rates for 214 light duty gasoline vehicles on 1,677 driving cycles, including 839 outbound cycles and 838 inbound cycles on the same routes. These vehicles represent a wide range of characteristics and emission standards. For each vehicle, the models were calibrated based on outbound cycles and were validated based on inbound cycles. The goodness-of-fit of the calibrated models was assessed using linear least squares regression without intercept between model-predicted versus empirical CAERs for individual vehicles. Based on model calibration and validation, the coefficients of determination ( R 2 ) typically range from 0.60 to 0.97 depending on the vehicle group and pollutant, indicating moderate to high precision, with precision typically higher for higher-emitting vehicle groups. The slopes of parity plots for each vehicle group and all vehicles typically range from 0.90 to 1.10, indicating good accuracy. The two modeling approaches are similar to each other at the microscopic and macroscopic levels. DA - 2020/7// PY - 2020/7// DO - 10.1177/0361198120924006 VL - 2674 IS - 7 SP - 566-584 SN - 2169-4052 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85094930128&partnerID=MN8TOARS ER - TY - JOUR TI - Utilization Management of Highway Operations Equipment AU - Mirheli, Amir AU - Tajalli, Mehrdad AU - Mohebifard, Rasool AU - Hajibabai, Leila AU - Hajbabaie, Ali T2 - TRANSPORTATION RESEARCH RECORD AB - This paper presents fleet utilization management processes for highway operations equipment based on actual tracked and reported usage data obtained from transportation agencies. The objective is to minimize total fleet utilization costs, including operational, purchase, and relocation expenses that yield the optimal utilization values and fleet composition of specific equipment types within each region in a year. The framework includes utilization prediction and optimization models, rather than relying on pre-determined utilization thresholds in existing strategies, to avoid under-utilization, over-utilization, or both. The prediction models are structured using equipment explanatory variables with their significant contributing factors, for example, annual equipment usage, annual fuel cost, downtime hours, age, and class code, to predict operational costs. The optimization model is formulated as a set of mathematical formulations, with embedded predictive models, that minimizes the total costs of (i) keeping an asset in-service using predictive annual operational cost functions, (ii) purchasing new assets in a region in the following year, and (iii) relocating assets by capturing the distance between regions. The costs include equipment purchase, operation, maintenance, and transportation expenses. The proposed framework captures the remedial actions to balance under-/over-utilized assets in the fleet in a cost-efficient manner. The proposed methodology is applied to utilization management of a set of operations equipment, and the findings of the dump trucks are presented. Several scenarios are designed to analyze the sensitivity of the costs to various decisions and parameters. The numerical experiments reveal that the proposed framework can facilitate the utilization prediction and management of highway operations equipment and save up to 16.6% in operational costs considering different demand scenarios. DA - 2020/9// PY - 2020/9// DO - 10.1177/0361198120927400 VL - 2674 IS - 9 SP - 202-215 SN - 2169-4052 ER - TY - JOUR TI - The Influence of Prescribed Fire on Fine Particulate Matter Pollution in the Southeastern United States AU - Afrin, Sadia AU - Garcia‐Menendez, Fernando T2 - Geophysical Research Letters AB - Abstract Prescribed fire is the largest source of fine particulate matter emissions in the Southeastern United States, yet its air quality impacts remain highly uncertain. Here, we assess the influence of prescribed fire on observed pollutant concentrations in the region using a unique fire data set compiled from multiyear digital burn permit records. There is a significant association between prescribed fire activity and concentrations recorded at Southeastern monitoring sites, with permitted burning explaining as much as 50% variability in daily PM 2.5 concentrations. This relationship varies spatially and temporally across the region and as a function of burn type. At most locations, the association between PM 2.5 concentration and permitted burning is stronger than that with satellite‐derived burn area or meteorological drivers of air quality. These results highlight the value of bottom‐up data in evaluating the contribution of prescribed fire to regional air pollution and reveal a need to develop more complete burn records. DA - 2020/8/16/ PY - 2020/8/16/ DO - 10.1029/2020GL088988 VL - 47 IS - 15 UR - https://doi.org/10.1029/2020GL088988 KW - prescribed fire KW - air quality KW - smoke ER - TY - JOUR TI - Fatigue Performance of Geosynthetic-Reinforced Asphalt Concrete Beams AU - Sudarsanan, Nithin AU - Arulrajah, Arul AU - Karpurapu, Rajagopal AU - Amirthalingam, Veeraragavan T2 - JOURNAL OF MATERIALS IN CIVIL ENGINEERING AB - One of the common distresses observed in asphalt concrete (AC) pavements under repeated vehicular and thermal loadings is cracking. Overlay placement is a quick remedy to rehabilitate these distressed surfaces. Unfortunately, this practice without treating the cracks will not resolve the cracking issue because the existing cracked surface soon propagates the cracks through the new layer, resulting in a phenomenon known as reflective cracking. Different types of geosynthetic interlayers have been used to retard the reflective cracks, thereby enhancing the overlay’s service life. The preliminary step in quantifying the service life improvement is measuring the fatigue life enhancement in the laboratory. This paper developed a test procedure to conduct four-point beam (4PB) fatigue tests, adapted a permanent deformation evolution model (PDEM) to predict the fatigue life of the 4PB specimens under laboratory testing conditions, and compared the fatigue life of beam specimens reinforced with three types of geosynthetics at 10°C, 20°C, and 30°C. The improvement factor measured using the PDEM model indicated that the geosynthetic reinforcement in AC beams increased the fatigue life on the order of 1.2–12 times depending upon the temperature at which the test was performed and the choice of the geosynthetic type. The best fatigue life outcome is expected when the improvement factor calculated for the geosynthetic-reinforced asphalt concrete’s bond strength and fracture energy meets the right combination of threshold values. The limitation of the study is that the improvement factors evaluated from the laboratory fatigue life require calibration factors to predict the field performance. Further field studies of the geosynthetic-reinforced pavements will help establish these calibration factors. DA - 2020/8/1/ PY - 2020/8/1/ DO - 10.1061/(ASCE)MT.1943-5533.0003267 VL - 32 IS - 8 SP - SN - 1943-5533 KW - Geosynthetics KW - Paving fabric KW - Four-point beam fatigue test KW - Fatigue life KW - Bond strength KW - Fracture energy KW - Geosynthetic interlayers KW - Natural geotextiles ER - TY - JOUR TI - Abrasion Resistance of Concrete Exposed to Organic Acids AU - Park, Sungwoo AU - Castellano, Lisa AU - Barlaz, Morton A. AU - Pour-Ghaz, Mohammad T2 - JOURNAL OF MATERIALS IN CIVIL ENGINEERING AB - The objective of this study is to investigate how exposure of concrete to organic acids affects its resistance to mechanical abrasion and to identify the most important factors contributing to its abrasion resistance under acid exposure. The abrasion resistance of both cement pastes and concrete materials with different water-to-cement ratios (w/c), coarse aggregate type, and proportions of aggregate were experimentally measured after exposure to organic acids. In addition, the effect of silica fume, latex, fibers, and chemical surface hardeners on the abrasion resistance of cement paste and concrete materials were investigated. The results indicate that in the absence or presence of an organic acid attack, the abrasion resistance of concrete is primarily a function of the hardness of the coarse aggregates and w/c plays a secondary role. While a secondary factor, the effect of w/c on the abrasion resistance is more significant in the presence of an organic acid attack. DA - 2020/8/1/ PY - 2020/8/1/ DO - 10.1061/(ASCE)MT.1943-5533.0003251 VL - 32 IS - 8 SP - SN - 1943-5533 ER - TY - JOUR TI - Geospatial Variation of Real-World Tailpipe Emission Rates for Light-Duty Gasoline Vehicles AU - Khan, Tanzila AU - Frey, H. Christopher AU - Rastogi, Nikhil AU - Wei, Tongchuan T2 - Environmental Science & Technology AB - Spatial variability in real-world on-road tailpipe light-duty gasoline vehicle nitrogen oxides, hydrocarbon, carbon monoxide, and carbon dioxide emission rates, the locations of emissions hotspots, and factors that explain spatial variability are quantified. A sample of 205 vehicles were measured on four predefined round-trip study routes using Portable Emission Measurement Systems. The trips on each route were divided into segments, averaging 1/4 mile in length. Segment-average emission rates were estimated based on measured 1 Hz emission rates. Emission hotspots are defined as segments with ≥90th percentile of segment-average emission rates. The hotspots have average emission rates 2-4 times greater, depending on the pollutant, than other segments. Hotspots are of heterogeneous characteristics including road attributes and vehicle activity metrics. For example, some hotspots were on arterial roads with an upstream signalized intersection and positive road grade, whereas some hotspots were on interstates with positive grade. Vehicle activity metrics, including average vehicle specific power and relative positive acceleration, help identify the hotspots. To reliably identify a fleet-average hotspot, data are needed for at least 36-130 vehicles, depending on the pollutant. DA - 2020/7/21/ PY - 2020/7/21/ DO - 10.1021/acs.est.0c00489 VL - 54 IS - 14 SP - 8968-8979 UR - https://doi.org/10.1021/acs.est.0c00489 ER - TY - JOUR TI - The Effect of Gas Solubility on the Secondary Sorption in a Portland Cement Mortar Observed by X-ray CT AU - Dalton, Laura E. AU - Jarvis, Karl AU - Pour-Ghaz, Mohammad T2 - TRANSPORT IN POROUS MEDIA DA - 2020/7// PY - 2020/7// DO - 10.1007/s11242-020-01429-6 VL - 133 IS - 3 SP - 397-411 SN - 1573-1634 KW - Air-entrained mortar KW - Air voids KW - Secondary sorptivity KW - X-ray computed tomography KW - Carbon dioxide KW - Methane KW - Water absorption ER - TY - JOUR TI - Crash Classification by Congestion Type for Highways AU - Song, Tai-Jin AU - Kim, Sangkey AU - Williams, Billy M. AU - Rouphail, Nagui M. AU - List, George F. T2 - APPLIED SCIENCES-BASEL AB - Effective management of highway networks requires a thorough understanding of the conditions under which vehicular crashes occur. Such an understanding can and should inform related operational and resource allocation decisions. This paper presents an easily implementable methodology that can classify all reported crashes in terms of the operational conditions under which each crash occurred. The classification methodology uses link-based speed data. Unlike previous secondary collision identification schemes, it neither requires an a priori identification of the precipitating incident nor definition of the precipitating incident’s impact area. To accomplish this objective, the methodology makes use of a novel scheme for distinguishing between recurrent and non-recurrent congestion. A 500-crash case study was performed using a 274 km section of the I-40 in North Carolina. Twelve percent of the case study crashes were classified as occurring in non-recurrent congestion. Thirty-seven percent of the crashes in non-recurrent congestion classified were identified within unreported primary incidents or crashes influence area. The remainder was classified as primary crashes occurring in either uncongested conditions (84%) or recurrent congestion (4%). The methodology can be implemented in any advanced traffic management system for which crash time and link location are available along with corresponding archived link speed data are available. DA - 2020/4// PY - 2020/4// DO - 10.3390/app10072583 VL - 10 IS - 7 SP - SN - 2076-3417 UR - https://doi.org/10.3390/app10072583 KW - collision classification KW - recurrent and non-recurrent congestion KW - link speed data KW - traffic safety KW - advanced traffic management system ER - TY - JOUR TI - Regulatory Adaptation in the Construction Industry: Case Study of the OSHA Update to the Respirable Crystalline Silica Standard AU - Li, Qingchun AU - Brannen, Laura AU - Rasoulkhani, Kambiz AU - Mostafavi, Ali AU - Stoa, Ryan AU - Chowdhury, Sudipta AU - Alsharef, Abdullah AU - Banerjee, Siddharth AU - Zhu, Jin AU - Jaselskis, Edward T2 - JOURNAL OF LEGAL AFFAIRS AND DISPUTE RESOLUTION IN ENGINEERING AND CONSTRUCTION AB - This paper presents a case study of a proposed regulatory future-proofing framework for the construction industry. The update to the crystalline silica standard by the Occupational Safety and Health Administration (OSHA) was selected and reviewed. The standard applies uniformly to the entire construction industry and experienced typical areas of regulatory uncertainties during the rulemaking process. The case study presents the organizational responses to the standard by two construction companies and a trade association. The study results demonstrate the importance of each process of regulatory future-proofing (i.e., horizon scanning, stakeholder engagement, risk and opportunity assessment, response strategy development, and compliance implementation) in proactive adaptation to regulatory uncertainties during the rulemaking process. Additionally, the results highlight several practices (such as robust communication with all relevant parties and allocating right-sizing resources) for effectively achieving implementation of regulatory future-proofing. DA - 2020/11// PY - 2020/11// DO - 10.1061/(ASCE)LA.1943-4170.0000424 VL - 12 IS - 4 SP - SN - 1943-4170 UR - http://dx.doi.org/10.1061/(asce)la.1943-4170.0000424 ER - TY - JOUR TI - Effectiveness of fly ash and cement for compressed stabilized earth block construction AU - Islam, Mohammad Shariful AU - Elahi, Tausif E. AU - Shahriar, Azmayeen Rafat AU - Mumtaz, Nashid T2 - CONSTRUCTION AND BUILDING MATERIALS AB - For saving natural resources, reducing pollution and increasing energy efficiency, Compressed Stabilized Earth Block (CSEB) can serve as a suitable alternative to conventional Fired Clay Brick (FCB). In this study, suitability of industrial waste, Fly Ash (FA) is assessed along with cement as stabilizers for producing CSEBs with coarse grained soil. Different combination of cement and FA (5–10% cement and 5–25% FA; by weight of dry soil) was considered to prepare CSEBs for finding the optimum mix composition in terms of strength, durability, deformation characteristics and cost effectiveness. Furthermore, strength and durability test results are compared to the design criteria reported in Indian Standard, Sri Lankan Standard, Standard Australia, British Standard and Malaysian Standard for assessing its viability as construction material. With the increase in cement content, strength of the blocks gradually increases; however, at a definite cement content, addition of FA increases strength up to a certain limit and then begins to drop. Inclusion of 7–8% cement and 15–20% FA is found to provide adequate dry compressive strength (>5 MPa), wet-to-dry compressive strength (>0.33) and enough durability in terms of water absorption (<20%) as recommended by British Standard and Standards Australia. The behavior of the CSEBs were also analyzed through microstructural investigation, where SEM images were taken to ascertain the morphologic and anatomic changes that occurred at different fly ash contents. At a definite cement content, with the increase of FA, peak strain and failure strain increase; thereby indicating an improved straining capacity of the blocks due to inclusion of FA. Moreover, modulus of elasticity improves with increasing amount of cement and FA for both dry and wet state. Furthermore, economic analysis of a typical house constructed with CSEBs and FCBs was performed and compared with literature. Considering all the parameters it can be concluded that CSEBs prepared with cement and fly ash as stabilizers can be used as a sustainable construction material. DA - 2020/9/20/ PY - 2020/9/20/ DO - 10.1016/j.conbuildmat.2020.119392 VL - 255 SP - SN - 1879-0526 KW - Cement KW - Fly ash KW - Compressed stabilized earth block KW - Compressive strength KW - Durability KW - Stress-strain behavior ER - TY - JOUR TI - Factors affecting variability in fossil-fueled transit bus emission rates AU - Wei, Tongchuan AU - Frey, H. Christopher T2 - ATMOSPHERIC ENVIRONMENT AB - Globally, there are over 10 million transit buses. Exhaust emissions from transit buses include carbon dioxide (CO2), carbon monoxide (CO), total hydrocarbons (THC), nitrogen oxides (NOx), and particulate matter (PM). Key factors affecting bus emission rates have been evaluated separately or in limited combinations in prior studies, including bus size, fuel and powertrain, passenger load, driving cycle, and model year. However, bus emission rates are jointly affected by all of these factors. To systematically evaluate these factors, a transit bus emissions model (TBEM) was developed. TBEM is calibrated based on generic compressed natural gas (CNG) and diesel bus types represented in the U.S. Environmental Protection Agency MOtor Vehicle Emission Simulator and empirical cycle average emission rates from the Integrated Bus Information System. The importance of the factors varies depending on the pollutant. For emission rates per vehicle-kilometer, model year is an important factor for NOx and PM, fuel and powertrain is an important factor for CO and THC, and driving cycle and bus size are important factors for CO2. For emission rates per passenger-kilometer, passenger load is generally an important factor for each pollutant. For a given fuel and powertrain and pollutant, smaller buses have lower emission rates per vehicle-kilometer than larger buses. However, a full large bus has lower emission rates per passenger-kilometer than a full small bus. There are tradeoffs among bus types regarding emission rates, especially for THC and PM. The comparison of bus emission rates is dependent on interactions between these key factors. For example, the effect of bus size and passenger load on emission rates is larger for lower speed driving cycles. For 2010 and newer model year buses and for moderate to high speed driving cycles, diesel buses have the lowest NOx emission rates whereas for low speed cycles, CNG buses have the lowest NOx emission rates. However, for 2007 to 2009 model year buses, CNG buses have the lowest NOx emission rates regardless of driving cycle. The study will be useful in helping transit planners and policy makers to develop strategies to reduce transit bus fleet emissions and in providing accurate emission factors for use in bus life cycle inventories and emission inventories. DA - 2020/7/15/ PY - 2020/7/15/ DO - 10.1016/j.atmosenv.2020.117613 VL - 233 SP - SN - 1873-2844 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85084988997&partnerID=MN8TOARS KW - Transit bus KW - Exhaust emissions KW - Bus size KW - Passenger load ER - TY - JOUR TI - Joint optimization of vehicle-group trajectory and signal timing: Introducing the white phase for mixed-autonomy traffic stream AU - Niroumand, Ramin AU - Tajalli, Mehrdad AU - Hajibabai, Leila AU - Hajbabaie, Ali T2 - Transportation Research Part C: Emerging Technologies AB - This study develops a novel mixed-integer non-linear program to control the trajectory of mixed connected-automated vehicles (CAVs) and connected human-driven vehicles (CHVs) through signalized intersections. The trajectory of CAVs is continuously optimized via a central methodology, while a new “white” phase is introduced to enforce CHVs to follow their immediate front vehicle. The movement of CHVs is incorporated in the optimization framework utilizing a customized linear car-following model. During the white phase, CAVs lead groups of CHVs through an intersection. The proposed formulation determines the optimal signal indication for each lane-group in each time step. We have developed a receding horizon control framework to solve the problem. The case study results indicate that the proposed methodology successfully controls the mixed CAV-CHV traffic under various CAV market penetration rates and different demand levels. The results reveal that a higher CAV market penetration rate induces more frequent white phase indication compared to green-red signals. The proposed program reduces the total delay by 19.6%–96.2% compared to a fully-actuated signal control optimized by a state-of-practice traffic signal timing optimization software. DA - 2020/7// PY - 2020/7// DO - 10.1016/j.trc.2020.102659 VL - 116 SP - 102659 J2 - Transportation Research Part C: Emerging Technologies LA - en OP - SN - 0968-090X UR - http://dx.doi.org/10.1016/j.trc.2020.102659 DB - Crossref KW - Connected and automated vehicle KW - White phase KW - Mixed-autonomy traffic KW - Selfdriving vehicles ER - TY - JOUR TI - Flood Flow Frequency Analysis to Estimate Potential Floodplain Nitrogen Treatment during Overbank Flow Events in Urban Stream Restoration Projects T2 - Water AB - Stream restoration for mitigation purposes has grown rapidly since the 1980s. As the science advances, some organizations (Chesapeake Bay Program, North Carolina Department of Environmental Quality) have approved or are considering providing nutrient credits for stream restoration projects. Nutrient treatment on floodplains during overbank events is one of the least understood processes that have been considered as part of the Chesapeake Bay Program’s Stream Restoration Nutrient Crediting program. This study analyzed ten years of streamflow and water quality data from five stations in the Piedmont of North Carolina to evaluate proposed procedures for estimating nitrogen removal on the floodplain during overbank flow events. The volume of floodplain flow, the volume of floodplain flow potentially treated, and the nitrogen load retained on the floodplain were calculated for each overbank event, and a sensitivity analysis was completed. On average, 9% to 15% of the total annual streamflow volume accessed the floodplain. The percentage of the average annual volume of streamflow potentially treated ranged from 1.0% to 5.1%. Annually, this equates to 0.2% to 1.0% of the total N load retained/removed on the floodplain following restoration. The relatively low nitrogen retention/removal rates were due to a majority of floodplain flow occurring during a few large events each year that exceeded the treatment capacity of the floodplain. On an annual basis, 90% of total floodplain flow occurred during half of all overbank events and 50% of total floodplain flow occurred during two to three events each year. Findings suggest that evaluating only overbank events may lead to undervaluing stream restoration because treatment is limited by hydrologic controls that restrict floodplain retention time. Treatment is further governed by floodplain and channel size. DA - 2020/5/30/ PY - 2020/5/30/ DO - 10.3390/w12061568 UR - http://dx.doi.org/10.3390/w12061568 KW - floodplain reconnection KW - flow frequency KW - flow separation KW - nutrient retention ER - TY - JOUR TI - Can the Stream Quantification Tool (SQT) Protocol Predict the Biotic Condition of Streams in the Southeast Piedmont (USA)? AU - Donatich, Sara AU - Doll, Barbara AU - Page, Jonathan AU - Nelson, Natalie T2 - Water AB - In some states, the Stream Quantification Tool (SQT) has been adopted to quantify functional change of stream mitigation efforts. However, the ability of the SQT protocol to predict biological function and uphold the premise of the Stream Functions Pyramid (Pyramid) remains untested. Macroinvertebrate community metrics in 34 headwater streams in Piedmont, North Carolina (NC, USA) were related to NC SQT protocol (version 3.0) factors and other variables relevant to ecological function. Three statistical models, including stepwise, lasso, and ridge regression were used to predict the NC Biotic Index (NCBI) and Ephemeroptera, Plecoptera, and Trichoptera (EPT) richness using two datasets: 21 SQT variables and the SQT variables plus 13 additional watershed, hydraulic, geomorphic, and physicochemical variables. Cross-validation revealed that stepwise and ridge outperformed lasso, and that the SQT variables can reasonably predict biology metrics (R2 0.53–0.64). Additional variables improved prediction (R2 0.70–0.88), suggesting that the SQT protocol is lacking metrics important to macroinvertebrates. Results moderately support the Pyramid: highly predictive ridge models included metrics from all levels, while highly predictive stepwise models included metrics from higher levels, and not watershed hydrology. Reach-scale metrics were more important than watershed hydrology, providing encouragement for projects limited by watershed condition. DA - 2020/5// PY - 2020/5// DO - 10.3390/w12051485 UR - https://www.mdpi.com/2073-4441/12/5/1485 KW - streams KW - rivers KW - restoration KW - ecological KW - stream function KW - benthic macroinvertebrates KW - stream quantification tool (SQT) KW - stream functions pyramid framework KW - compensatory mitigation ER - TY - JOUR TI - A Framework for Planning and Evaluating the Role of Urban Stream Restoration for Improving Transportation Resilience to Extreme Rainfall Events AU - Doll, Barbara AU - Kurki-Fox, J. Jack AU - Line, Daniel E. T2 - Water AB - Recent extreme rainfall events produced severe flooding across North Carolina’s Coastal Plain, revealing deep vulnerabilities in many communities. Climate change is expected to exacerbate these problems by further increasing rainfall intensity and the frequency of extreme rainfall events. Due to the risks posed by these changing rainfall patterns, a shift in the approach to infrastructure planning and management is needed for many floodprone communities, particularly in regard to managing streams and floodplains in urban areas. This study proposes a framework for systematically evaluating stream restoration in combination with engineered improvements to culvert and bridge crossings to identify and optimize options for mitigating extreme events in urban areas. To illustrate the methodology, extensive hydraulic modeling was conducted to test four different strategies for reducing flooding along a channelized and armored stream, Big Ditch, located in Goldsboro, North Carolina, USA. The results indicate that neither floodplain restoration nor infrastructure modification alone could alleviate flooding along Big Ditch. Rather, a combination approach would be required to mitigate flooding, which could result in substantial benefits for storms in excess of the 100-year event. The results suggest that shifting to a multi-faceted approach to improve resiliency to extreme events could improve public safety and reduce future damages due to flooding. DA - 2020/6// PY - 2020/6// DO - 10.3390/w12061620 UR - https://www.mdpi.com/2073-4441/12/6/1620 KW - stream restoration KW - flooding KW - climate change KW - extreme events KW - transportation resilience ER - TY - JOUR TI - Within station variability in kappa: evidence of directionality effects AU - Ji, C. AU - Cabas Mijares, A. AU - Cotton, F. AU - Pilz, M. AU - Bindi, D. T2 - Bulletin of the Seismological Society of America AB - ABSTRACT One of the most commonly used parameters to describe seismic attenuation is the high-frequency spectral decay parameter Kappa (κr), yet the physics behind it remain little understood. A better understanding of potential factors that lead to large scatter in estimated values of κr constitutes a critical need for ground-motion modeling and seismic hazard assessment at large. Most research efforts to date have focused on studying the site-to-site and model-to-model variability of κ, but the uncertainties in individual κr estimations associated with different events at a selected site (which we refer to as the within-station variability of κr) remain uncharacterized. As a direct corollary, obtaining robust estimates of the site-specific component κ0, and their corresponding interpretation become a challenge. To understand the sources of the variability observed in κr (and κ0) at a single site, we select 10 Japanese Kiban–Kyoshin network (KiK-net) downhole arrays and investigate the systematic contributions from ground-motion directionality. We observe that κr estimated from a single horizontal component is orientation dependent. In addition, the influence of ground-motion directionality is a function of local site conditions. We propose an orientation-independent κr-value, which is not affected either by ground-motion directionality or by the events’ azimuths. In addition, we find that focal depth of events used in κr calculations affects the estimation of the regional attenuation component κR, which, in turn, influences the within-station variability in the κ0 model. DA - 2020/4/21/ PY - 2020/4/21/ DO - 10.1785/0120190253 VL - 110 IS - 3 SP - 1247–1259 SN - 1943-3573 ER - TY - JOUR TI - Potential for metro rail energy savings and emissions reduction via eco-driving AU - Yuan, Weichang AU - Frey, H. Christopher T2 - APPLIED ENERGY AB - Metro rail energy efficiency needs to be improved to compensate for growing capacity demand. Eco-driving aims to reduce energy consumption without affecting safety and passenger comfort. Estimates of energy savings from train eco-driving are typically based on theoretical speed trajectory optimization models. However, achievable energy savings from eco-driving should be assessed based on realistic trajectories. A Markov chain speed trajectory simulator calibrated to measured trajectories was used to simulate realistic inter-run variability in 1 Hz trajectories. The simulator was calibrated and applied to the Washington Metropolitan Area Transit Authority Metrorail system. Estimated energy consumption for each trajectory includes auxiliary loads and tractive effort to overcome resistive forces. Inter-run variability in estimated energy consumption implies opportunities for energy savings via eco-driving. Energy savings was quantified by comparing the lowest and average segment energy consumption. A segment is the one-way rail track between adjacent stations of each line. Simulated trajectories are similar to measured trajectories based on mean absolute error and coefficient of determination (R2) for the same operation mode sequence. Based on 100 simulations per segment, energy savings ranging from 5% to 50% among segments and from 14% to 18% at the system level can be achieved without modifying travel time. Energy savings lead to reduced electricity consumption and, therefore, reduced power generation emissions. The method demonstrated here to quantify opportunities for metro train energy conservation and emissions mitigation is broadly applicable to electric metro and commuter trains and rail segments. Implications for energy-efficient passenger rail planning and operation are discussed. DA - 2020/6/15/ PY - 2020/6/15/ DO - 10.1016/j.apenergy.2020.114944 VL - 268 SP - SN - 1872-9118 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85083432807&partnerID=MN8TOARS KW - Public transport KW - Automatic train operation KW - Energy efficiency KW - Eco-driving KW - Electricity KW - Markov chain ER - TY - JOUR TI - Synthesis of Irrigation Water Use in the United States: Spatiotemporal Patterns AU - Das Bhowmik, Rajarshi AU - Seo, Seung Beom AU - Das, Priyam AU - Sankarasubramanian, A. T2 - JOURNAL OF WATER RESOURCES PLANNING AND MANAGEMENT AB - The role of large-scale drivers—climate, population, and adaption of efficient irrigation practices—in controlling irrigation water use efficiency has rarely been addressed. The primary objectives of our study are to (1) investigate the long-term changes in irrigation water use over the contiguous United States using a nationwide, multidecadal database created by USGS; and (2) understand the role of large-scale drivers in the water application rate, an indicator of irrigation efficiency. The authors find that the eastern states are currently withdrawing more surface water than in the past, while groundwater withdrawal has increased across all states. An increase in efficient irrigation schemes is leading to a decrease in traditional flood irrigation schemes. Spatiotemporal analyses confirm that the eastern states are presently withdrawing more irrigation water per acreage than in the past. While the choice of efficient irrigation practices (sprinkler and drip) is the major driver influencing the application rate, other factors such as cost and type of crops predominantly determine the type of irrigation system chosen for improving the application rate. DA - 2020/7/1/ PY - 2020/7/1/ DO - 10.1061/(ASCE)WR.1943-5452.0001249 VL - 146 IS - 7 SP - SN - 1943-5452 KW - Water use KW - Irrigation KW - Water application rate KW - Agricultural management ER - TY - JOUR TI - The impact of pressure, moisture and temperature on pyrolysis of municipal solid waste under simulated landfill conditions and relevance to the field data from elevated temperature landfill AU - Tupsakhare, Swanand AU - Moutushi, Tasnuva AU - Castaldi, Marco J. AU - Barlaz, Morton A. AU - Luettich, Scott AU - Benson, Craig H. T2 - SCIENCE OF THE TOTAL ENVIRONMENT AB - Experiments were conducted with simulated Municipal Solid Waste (MSW) to understand the impact of pressure, moisture, and temperature on MSW decomposition under simulated landfill conditions. Three experimental phases were completed, where the first two phases provided baseline results and assisted in fine tuning parameters such as pressure, temperature, gas composition, and moisture content for phase three. The manuscript focuses on the results from third phase. In the third phase, the composition of the gases evolved from representative MSW samples was tested over time in two pressure conditions, 101 kilopascals (kPa) (atmospheric pressure) and 483 kPa, with varying moisture contents (38 to 55 wt%) and controlled temperatures (50 to 200 °C) in the presence of biological inhibitors. The headspace in the reactor in phase three was pressurized with gas mixture of 50/50 (vol%) of methane (CH4) and carbon dioxide (CO2) setting the initial CH4/CO2 gas composition ratio to 1.0 at time t = 0 days. The results established moisture ranges that affect hydrogen (H2) production and the CH4/CO2 ratio at different temperature and pressure conditions. Results show that at 85 °C, there was a change in the CH4/CO2 ratio from 1.0 to 0.3. Additionally, moisture contents from 47 to 43.5 wt% caused the CH4/CO2 ratio to increase from 1.0 to 1.2, yet from 43.5 to 38 wt%, the ratio reversed and declined to 0.3, returning to 1.0 for moisture levels below 38 wt%. Thus, moisture levels above 47 wt% and below 38 wt%, for the system tested, allow thermal reactions to proceed without a measured change in CH4/CO2 ratio. H2 generation rates follow a similar trend with moisture, yet definitively increase with increased pressure from 101 kPa to 483 kPa. The observed change in solid MSW and gas composition under controlled pressure, moisture, and temperature suggests the presence of thermal reactions in the absence of oxygen. DA - 2020/6/25/ PY - 2020/6/25/ DO - 10.1016/j.scitotenv.2020.138031 VL - 723 SP - SN - 1879-1026 KW - Municipal solid waste KW - Landfill KW - Pyrolysis KW - Elevated temperature landfills KW - Solid waste management KW - Thermal reactions ER - TY - JOUR TI - How Does Experience with Delay Shape Managers' Making-Do Decision: Random Forest Approach AU - Zhang, YuXiang AU - Javanmardi, Ashtad AU - Liu, YanChun AU - Yang, ShuJuan AU - Yu, XiuXia AU - Hsiang, Simon M. AU - Jiang, ZhiHao AU - Liu, Min T2 - JOURNAL OF MANAGEMENT IN ENGINEERING AB - Making-do, a decision to start a construction task despite knowing that its preconditions are not fully ready, is a complex dilemma for construction managers. Managers’ previous making-do decisions and the resulting consequence, delay, can have a significant impact on future making-do decisions. To understand how managers’ experience with delay impacts their making-do decision and how it is handled differently in different countries, two surveys were administered, one in China and one in the United States (US), and 260 usable responses were collected. This study used: (1) the Mann–Whitney U test to examine whether delaying task starting time, when lacking precondition readiness, pays off with shorter delays; (2) a random forest approach to find important causes of delay that contribute to a making-do decision; and (3) an entropy-based decision tree to determine how much uncertainty in making-do decisions can be reduced by knowing managers’ experience with delays in past projects. Results showed that in the United States, managers who preferred the making-do approach experienced up to 60% less task duration delay; whereas Chinese managers who preferred making-do experienced up to 100% more task duration delay due to lack of readiness in labor, equipment, material, management, and information flow. The contributions to the body of knowledge are the development of a random forest approach to quantitatively examine the relative importance of the causes of delay to the making-do decision and to reveal the fundamental differences in culture and management traditions that cause the difference between the two countries. The methods presented in this study will enable others to use a similar random forest approach repetitively for classification, prediction, and variable selection problems in civil engineering. The findings of this study will help project managers better understand underlying factors that trigger making-do decisions in China and the United States, and have more efficient collaboration and communication when they work on projects located in a foreign country. DA - 2020/7/1/ PY - 2020/7/1/ DO - 10.1061/(ASCE)ME.1943-5479.0000776 VL - 36 IS - 4 SP - SN - 1943-5479 KW - Making-do KW - Random forest KW - Decision tree KW - Information theory KW - China KW - United States KW - Construction ER - TY - JOUR TI - A novel gripper for multiaxial mechanical testing of microtubes at elevated temperatures AU - Li, Lin AU - Chan, Yu-Chin AU - Ngaile, Gracious AU - Hassan, Tasnim T2 - REVIEW OF SCIENTIFIC INSTRUMENTS AB - The success of a microtube hydroforming (μTHF) process heavily depends on the material properties of microtubes, which can reveal the material response under multiaxial stress and influence the formability of hydroformed products. However, these material properties are not well understood because of the limited availability of material testing apparatus that would permit control of axial force and internal pressure simultaneously to mimic realistic μTHF loading. The main purpose of this study is to develop a set of grippers that can transfer required testing loads under fully coupled combinations of axial force and internal pressure. The grippers are designed so that they may be kept at the safe working temperature even when tests are carried out at higher temperatures. The grippers are also designed to fit in a load frame that is integrated in a scanning electron microscope for in situ material testing. The capabilities of the grippers are demonstrated by performing uniaxial and multiaxial material tests on SS304 microtubes with 1 mm outside diameter and 0.15 mm nominal tube wall thickness. The finite element simulations and experimental results show that the designed grippers can firmly hold the specimen and thus enable tensile, compression, torsion, and microtube bulge material tests to be accurately performed. DA - 2020/5/1/ PY - 2020/5/1/ DO - 10.1063/5.0007150 VL - 91 IS - 5 SP - SN - 1089-7623 ER - TY - JOUR TI - Review of Modeling Methodologies for Managing Water Distribution Security AU - Berglund, Emily Zechman AU - Pesantez, Jorge E. AU - Rasekh, Amin AU - Shafiee, M. Ehsan AU - Sela, Lina AU - Haxton, Terranna T2 - Journal of Water Resources Planning and Management AB - Water distribution systems are vulnerable to hazards that threaten water delivery, water quality, and physical and cybernetic infrastructure. Water utilities and managers are responsible for assessing and preparing for these hazards, and researchers have developed a range of computational frameworks to explore and identify strategies for what-if scenarios. This manuscript conducts a review of the literature to report on the state of the art in modeling methodologies that have been developed to support the security of water distribution systems. First, the major activities outlined in the emergency management framework are reviewed; the activities include risk assessment, mitigation, emergency preparedness, response, and recovery. Simulation approaches and prototype software tools are reviewed that have been developed by government agencies and researchers for assessing and mitigating four threat modes, including contamination events, physical destruction, interconnected infrastructure cascading failures, and cybernetic attacks. Modeling tools are mapped to emergency management activities, and an analysis of the research is conducted to group studies based on methodologies that are used and developed to support emergency management activities. Recommendations are made for research needs that will contribute to the enhancement of the security of water distribution systems. DA - 2020/8// PY - 2020/8// DO - 10.1061/(ASCE)WR.1943-5452.0001265 VL - 146 IS - 8 UR - https://doi.org/10.1061/(ASCE)WR.1943-5452.0001265 ER - TY - JOUR TI - Natural and anthropogenic-induced changes in a tidal inlet: Morphological evolution of Oregon Inlet AU - Velasquez-Montoya, Liliana AU - Overton, Margery F. AU - Sciaudone, Elizabeth J. T2 - GEOMORPHOLOGY AB - Natural processes driving the dynamics of tidal inlets have been studied in length, however, as human influence in the coastal environment persists, there is a need to comprehend how both natural and human-induced processes drive different aspects of tidal inlet morphological evolution. An effort to understand the combined effects of natural and anthropogenic-induced processes in a tidal inlet is pursued by studying Oregon Inlet, considered one of the most dynamic inlets in the Outer Banks of North Carolina, USA. The temporal and spatial scales of the anthropogenic processes driving the morphological evolution of this tidal inlet are studied by means of remotely sensed data and in-situ observations gathered from 2005 until 2015. Effects of natural process that cannot be gathered from observations are studied via a morphological model based on Delft3D. Evolutional trends include the cyclical response of the main channel of the inlet to dredging, a 13° northward rotation of the main channel, and frequent sediment transport reversal in the southern shoulder. Simulations indicate a net sediment transport rate into the inlet of 205,000 m3/yr. Tidal currents are responsible for 55% of such transport, while waves account for the remaining 45%. After a 2-year non-dredging modeling scenario, sediments from the subaqueous spit form a detached shoal in the north side of the flood delta and the main channel remains open branching into two dominant channels. Observations and model results indicate that Oregon Inlet has been in a state of stable equilibrium in the past decade. Natural and human-induced processes contribute to such equilibrium. This study exemplifies the decadal behavior of a tidal inlet influenced by natural processes, infrastructure, and dredging. DA - 2020/2/1/ PY - 2020/2/1/ DO - 10.1016/j.geomorph.2019.106871 VL - 350 SP - SN - 1872-695X KW - Nearshore processes KW - Coastal morphodynamics KW - Numerical modeling KW - Dredging KW - Human impacts KW - Outer Banks of North Carolina ER - TY - JOUR TI - Shear Strength Envelopes of Biocemented Sands with Varying Particle Size and Cementation Level AU - Nafisi, Ashkan AU - Montoya, Brina M. AU - Evans, T. Matthew T2 - JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING AB - Microbial-induced calcium carbonate precipitation (MICP) is a bio-mediated technique that may be used to improve the strength and stiffness of soils. Various parameters affect the behavior of MICP-cemented sand, and their effects must be explored before upscaling the MICP treatment technique. The study presented herein investigates the shear response of three types of sand (Ottawa 20-30, Ottawa 50-70, and Nevada) sheared in drained triaxial compression under three effective confining pressures (10, 100, and 400 kPa) at four levels of cementation (untreated, light, moderate, and heavy). Measurements of shear wave velocity were used for process monitoring throughout biotreatment. Shear wave velocity was used as an index to represent the cementation levels. After shearing, the calcium carbonate content was measured directly. Treated specimens showed similar shear responses at a given cementation level, although the number of treatments and the mass of precipitated calcium carbonate varied widely. Bilinear and nonlinear failure envelopes are proposed based on the obtained results to estimate the shear strength of MICP-treated sand. The shear strength parameters are estimated based on the developed bilinear failure envelope. SEM images were used to visually track the evolution of cementation at different cement contents. The predominant crystal phase of precipitated calcium carbonate was visually identified to be calcite. DA - 2020/3// PY - 2020/3// DO - 10.1061/(ASCE)GT.1943-5606.0002201 VL - 146 IS - 3 SP - SN - 1943-5606 KW - Microbial-induced calcium carbonate precipitation (MICP) KW - Shear response KW - Shear wave velocity KW - Failure envelope ER - TY - JOUR TI - Storm-driven erosion and inundation of barrier islands from dune-to region-scales AU - Gharagozlou, Alireza AU - Dietrich, Joel Casey AU - Karanci, Ayse AU - Luettich, Richard A. AU - Overton, Margery F. T2 - COASTAL ENGINEERING AB - Barrier islands are susceptible to erosion, overwash, and breaching during intense storms. However, these processes are not represented typically in large-domain models for storm surge and coastal inundation. In this study, we explore the requirements for bridging the gap between dune-scale morphodynamic and region-scale flooding models. A high-resolution XBeach model is developed to represent the morphodynamics during Hurricane Isabel (2003) in the North Carolina (NC) Outer Banks. The model domain is extended to more than 30km of Hatteras Island and is thus larger than in previous studies. The predicted dune erosion is in good agreement with post-storm observed topography, and an ‘‘excellent’’ Skill Score of 0.59 is obtained on this large domain. Sensitivity studies show the morphodynamic model accuracy is decreased as the mesh spacing is coarsened in the cross-shore direction, but the results are less sensitive to the alongshore resolution. A new metric to assess model skill, Water Overpassing Area (WOA), is introduced to account for the available flow pathway over the dune crest. Together, these findings allow for upscaled parameterizations of erosion in larger-domain models. The updated topography, obtained from XBeach prediction, is applied in a region-scale flooding model, thus allowing for enhanced flooding predictions in communities along the Outer Banks. It is found that, even using a fixed topography in region-scale model, the flooding predictions are improved significantly when post-storm topography from XBeach is implemented. These findings can be generalized to similar barrier island systems, which are common along the U.S. Gulf and Atlantic coasts. DA - 2020/6// PY - 2020/6// DO - 10.1016/j.coastaleng.2020.103674 VL - 158 SP - SN - 1872-7379 UR - http://dx.doi.org/10.1016/j.coastaleng.2020.103674 KW - XBeach KW - Hurricane Isabel KW - Outer banks KW - Coastal morphodynamics KW - ADCIRC plus SWAN ER - TY - JOUR TI - Enabling Organic Micropollutant Removal from Water by Full-Scale Biochar and Activated Carbon Adsorbers Using Predictions from Bench-Scale Column Data AU - Kearns, Joshua AU - Dickenson, Eric AU - Knappe, Detlef T2 - ENVIRONMENTAL ENGINEERING SCIENCE AB - Organic micropollutants (MPs), such as pesticides, pharmaceuticals, industrial compounds, and waste breakdown products occurring in waters at ng/L-μg/L levels are a threat to ecosystems and human health. Adsorption of MPs using granular activated carbon (GAC) is an increasingly common treatment process. Biochar is a promising low-cost, environmentally sustainable surrogate for GAC in diverse water quality applications. Challenges remain, however, for accurately simulating real-world biochar and GAC adsorbers in laboratory experiments. The goal of this research was to develop a scale-up procedure for predicting the adsorption of organic MPs from water containing background dissolved organic matter (DOM) by GAC and biochar using bench-scale column tests. The removal of 11 native MPs in wastewater effluent by GAC and biochar was quantified using pilot-scale adsorbers and rapid small-scale column tests (RSSCTs). Batch isotherm studies were conducted and RSSCT data were fit with two different surface and pore diffusion models to obtain equilibrium and kinetic parameters for each MP-adsorbent combination. The diffusion models were used to predict MP breakthrough at full scale, and predictions compared with pilot column data. A third scale-up approach was applied using a fouling index to account for the effects of DOM competition and pore blockage on MP uptake. A fourth approach was applied using direct empirical correlation between early MP breakthrough in RSSCT and pilot columns. The criterion for comparison of the ability of model-based and empirical scale-up approaches to accurately simulate pilot-scale adsorption was the number of bed volumes treated until MP breakthrough at 10% of the influent concentration (BV10%). Data obtained in this study as well as from the literature were used to develop an empirical regression based on RSSCT BV10% values to provide a user-oriented, conservative approach to predicting full-scale MP breakthrough that can be used for the design and operation of biochar and GAC treatment systems. DA - 2020/7/1/ PY - 2020/7/1/ DO - 10.1089/ees.2019.0471 VL - 37 IS - 7 SP - 459-471 SN - 1557-9018 KW - activated carbon KW - adsorption modeling KW - biochar KW - contaminants of emerging concern KW - rapid small-scale column testing KW - wastewater ER - TY - JOUR TI - Focus on the fatal-four: Implications for construction hazard recognition AU - Albert, Alex AU - Pandit, Bhavana AU - Patil, Yashwardhan T2 - SAFETY SCIENCE AB - Much effort has been devoted to improving hazard recognition in the construction industry. One such effort is the training outreach program pioneered and promoted by the Occupational Safety and Health Administration (OSHA) – commonly known as the Construction Focus Four or the Construction Fatal Four program. This program which is integrated in much of the training efforts offered in the construction industry seeks to promote hazard recognition and management by focusing on the four leading causes of fatal incidents – namely falls, caught-in/between, struck-by, and electrocution (i.e., fatal-four) hazards. Given the emphasis of these hazards in most training efforts, the objective of the current research was to explore if there are any performance disparities among workers in recognizing hazards that fall under the fatal-four and the non-fatal-four hazard categories. To accomplish this research goal, more than 280 workers were recruited from 57 construction workplaces in the United States to participate in a hazard recognition activity. The results of the study reveal that workers fail to recognize a disproportionate number of safety hazards in both the fatal-four and the non-fatal-four hazard categories. However, workers are relatively more proficient in recognizing hazards in the fatal-four hazard category than the non-fatal-four hazard category. More specifically, on average, the participating workers roughly recognized 57% of the fatal-four safety hazards while only recognizing 18% of the non-fatal-four safety hazards. Collectively, these findings suggest that apart from focusing on the fatal-four hazards, training efforts must also focus on the non-fatal-four safety hazards – given the relative poor performance. DA - 2020/8// PY - 2020/8// DO - 10.1016/j.ssci.2020.104774 VL - 128 SP - SN - 1879-1042 KW - Construction safety KW - Hazard recognition KW - Hazard identification KW - Occupational safety KW - Fatal injuries KW - Injury prevention KW - Hazard management ER - TY - JOUR TI - Fatigue-Creep Interaction of P92 Steel and Modified Constitutive Modelling for Simulation of the Responses AU - Zhang, Tianyu AU - Wang, Xiaowei AU - Zhang, Wei AU - Hassan, Tasnim AU - Gong, Jianming T2 - METALS AB - Fatigue–creep interaction (FCI) responses of P92 steel are investigated experimentally and numerically. A series of isothermal FCI experiments with tensile dwell time ranging from 60 to 600 s were conducted at two temperatures under strain-controlled trapezoidal waveform. The experimental responses demonstrate that the peak stress is influenced by temperature and dwell time. In other words, creep-mechanism-influenced stress relaxation during dwell time influences the peak stress and fatigue life (Nf). In addition, effects of strain range on peak stress and fatigue life under fatigue–creep loading are evaluated. Towards developing a simulation-based design methodology for high temperature components, first a conventional unified constitutive model is evaluated against the P92 steel experimental responses. Based on the simulation deficiency of the conventional model, a modified static recovery term incorporated in the kinematic hardening rule is proposed and satisfactory simulations of the P92 steel FCI responses are demonstrated. The experimental responses of P92 steel and strengths and deficiencies of the conventional and modified Chaboche models are elaborated identifying the important FCI phenomena and progress in constitutive model development for FCI response simulation. DA - 2020/3// PY - 2020/3// DO - 10.3390/met10030307 VL - 10 IS - 3 SP - SN - 2075-4701 KW - P92 steel KW - fatigue-creep interaction KW - unified constitutive model KW - static recovery KW - stress relaxation ER - TY - JOUR TI - Flexural performance of pretensioned ultra-high performance fibre reinforced concrete beams with CFRP tendons AU - Sturm, A. B. AU - Visintin, P. AU - Seracino, R. AU - Lucier, G. W. AU - Oehlers, D. J. T2 - COMPOSITE STRUCTURES AB - In this paper, the mechanical performance of pretensioned concrete girders manufactured with ultra-high performance fibre reinforced concrete (UHPFRC) and carbon fibre reinforced polymer (CFRP) tendons is explored both experimentally and analytically. For the experimental investigation, four UHPFRC beams with either steel or CFRP tendons are tested under four point bending to failure. Digital image correlation is used to monitor the development of cracks. These results are then used to validate a rational analysis technique based on the modelling of concrete cracking and crushing through the application of partial interaction mechanics which is then compared to that suggested by codes of practice DA - 2020/7/1/ PY - 2020/7/1/ DO - 10.1016/j.compstruct.2020.112223 VL - 243 SP - SN - 1879-1085 ER - TY - JOUR TI - Geospatial and Hydraulic Simulation to Design District Metered Areas for Large Water Distribution Networks AU - Pesantez, Jorge E. AU - Berglund, Emily Zechman AU - Mahinthakumar, G. T2 - Journal of Water Resources Planning and Management AB - Water distribution systems can be divided into district metered areas (DMAs) to improve their management. DMAs are individual service regions within a distribution system that have a defined set of supply sources, and hydraulic and quality parameters can be controlled at their entrances. Designing DMA configurations to meet management goals, such as pressure or demand uniformity, is challenging because of the unique topological conditions of each water system, the variability in water demand required by each geographic zone, and the high interconnection of pipes within water systems. This research couples geospatial analysis with a hydraulic simulator to design DMAs for a highly constrained large water network. Solutions specify modifications of valve settings and tank operations and the addition of new pipes to the network. The performance of the DMA design is evaluated based on objectives to minimize implementation cost, demand similarity, pressure uniformity, and water age and constraints related to pressure and number of entrances per district. The methodology is applied to design DMAs for E-Town, a large water system that was presented at the Battle of Water Networks District Metered Areas. The coupled approach identifies DMA designs that satisfy constraints with satisfactory performance for multiple objectives. DA - 2020/7// PY - 2020/7// DO - 10.1061/(ASCE)WR.1943-5452.0001243 UR - https://doi.org/10.1061/(ASCE)WR.1943-5452.0001243 KW - Urban water systems KW - District metered areas (DMAs) KW - Hydraulic modeling KW - Geospatial tools ER - TY - JOUR TI - HESS Opinions: Beyond the long-term water balance: evolving Budyko's supply–demand framework for the Anthropocene towards a global synthesis of land-surface fluxes under natural and human-altered watersheds AU - Sankarasubramanian, A. AU - Wang, Dingbao AU - Archfield, Stacey AU - Reitz, Meredith AU - Vogel, Richard M. AU - Mazrooei, Amirhossein AU - Mukhopadhyay, Sudarshana T2 - Hydrology and Earth System Sciences AB - Abstract. Global hydroclimatic conditions have been substantially altered over the past century by anthropogenic influences that arise from the warming global climate and from local/regional anthropogenic disturbances. Traditionally, studies have used coupling of multiple models to understand how land-surface water fluxes vary due to changes in global climatic patterns and local land-use changes. We argue that because the basis of the Budyko framework relies on the supply and demand concept, the framework could be effectively adapted and extended to quantify the role of drivers – both changing climate and local human disturbances – in altering the land-surface response across the globe. We review the Budyko framework, along with these potential extensions, with the intent of furthering the applicability of the framework to emerging hydrologic questions. Challenges in extending the Budyko framework over various spatio-temporal scales and the use of global datasets to evaluate the water balance at these various scales are also discussed. DA - 2020/4/17/ PY - 2020/4/17/ DO - 10.5194/hess-24-1975-2020 VL - 24 IS - 4 SP - 1975–1984 SN - 1607-7938 UR - http://dx.doi.org/10.5194/hess-24-1975-2020 ER - TY - JOUR TI - Poultry Ownership Associated with Increased Risk of Child Diarrhea: Cross-Sectional Evidence from Uganda T2 - The American Journal of Tropical Medicine and Hygiene AB - Domestic animals have been associated with enteric infections in young children and can also be carriers of respiratory viruses. We conducted a cross-sectional assessment of health outcomes in children aged < 5 years associated with animal presence among 793 rural households in Uganda. We recorded the 2-week prevalence of diarrhea and respiratory infections in children, and the number of cows, poultry, sheep/goats, and pigs in the household. We used generalized linear models with robust standard errors to estimate the prevalence ratio (PR) for diarrhea and respiratory infections associated with households owning the above- versus below-median number of animals. We conducted unadjusted and adjusted analyses controlling for socioeconomic, water, sanitation, and hygiene indicators. Children in households with the above-median number (> 5) of poultry had 83% higher diarrhea prevalence than those with ≤ 5 poultry (adjusted PR = 1.83 [1.04, 3.23], P = 0.04). Children in households with the above-median number (> 2) of cows had 48% lower prevalence of respiratory infection than those with ≤ 2 cows (adjusted PR = 0.52 [0.35, 0.76], P < 0.005). There were no other significant associations between domestic animals and child health. Studies should assess if barring chickens from indoor living quarters and sanitary disposal of chicken and other animal feces can reduce childhood zoonotic infections. DA - 2020/3/5/ PY - 2020/3/5/ DO - 10.4269/ajtmh.19-0012 UR - http://dx.doi.org/10.4269/ajtmh.19-0012 ER - TY - JOUR TI - Pilot scale removal of per- and polyfluoroalkyl substances and precursors from AFFF-impacted groundwater by granular activated carbon AU - Rodowa, Alix E. AU - Knappe, Detlef R. U. AU - Chiang, Sheau-Yun Dora AU - Pohlmann, Dirk AU - Varley, Catharine AU - Bodour, Adria AU - Field, Jennifer A. T2 - ENVIRONMENTAL SCIENCE-WATER RESEARCH & TECHNOLOGY AB - The US military, municipal fire stations, airports, and the petroleum-processing industry have used aqueous film forming foam (AFFF) to extinguish hydrocarbon-based fires. DA - 2020/4/1/ PY - 2020/4/1/ DO - 10.1039/c9ew00936a VL - 6 IS - 4 SP - 1083-1094 SN - 2053-1419 ER - TY - JOUR TI - Uncertainty Quantification of Simplified Viscoelastic Continuum Damage Fatigue Model using the Bayesian Inference-Based Markov Chain Monte Carlo Method AU - Ding, Jing AU - Wang, Yizhuang David AU - Gulzar, Saqib AU - Kim, Youngsoo Richard AU - Underwood, B. Shane T2 - TRANSPORTATION RESEARCH RECORD AB - The simplified viscoelastic continuum damage model (S-VECD) has been widely accepted as a computationally efficient and a rigorous mechanistic model to predict the fatigue resistance of asphalt concrete. It operates in a deterministic framework, but in actual practice, there are multiple sources of uncertainty such as specimen preparation errors and measurement errors which need to be probabilistically characterized. In this study, a Bayesian inference-based Markov Chain Monte Carlo method is used to quantify the uncertainty in the S-VECD model. The dynamic modulus and cyclic fatigue test data from 32 specimens are used for parameter estimation and predictive envelope calculation of the dynamic modulus, damage characterization and failure criterion model. These parameter distributions are then propagated to quantify the uncertainty in fatigue prediction. The predictive envelope for each model is further used to analyze the decrease in variance with the increase in the number of replicates. Finally, the proposed methodology is implemented to compare three asphalt concrete mixtures from standard testing. The major findings of this study are: (1) the parameters in the dynamic modulus and damage characterization model have relatively strong correlation which indicates the necessity of Bayesian techniques; (2) the uncertainty of the damage characteristic curve for a single specimen propagated from parameter uncertainties of the dynamic modulus model is negligible compared to the difference in the replicates; (3) four replicates of the cyclic fatigue test are recommended considering the balance between the uncertainty of fatigue prediction and the testing efficiency; and (4) more replicates are needed to confidently detect the difference between different mixtures if their fatigue performance is close. DA - 2020/4// PY - 2020/4// DO - 10.1177/0361198120910149 VL - 2674 IS - 4 SP - 247-260 SN - 2169-4052 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85083645522&partnerID=MN8TOARS ER - TY - JOUR TI - Development of virtual reality and stereo-panoramic environments for construction safety training AU - Jeelani, Idris AU - Han, Kevin AU - Albert, Alex T2 - Engineering, Construction and Architectural Management AB - Purpose Workers and construction professionals are generally not proficient in recognizing and managing safety hazards. Although valuable, traditional training experiences have not sufficiently addressed the issue of poor hazard recognition and management in construction. Since hazard recognition and management are cognitive skills that depend on attention, visual examination and decision-making, performance assessment and feedback in an environment that is realistic and representative of actual working conditions are important. The purpose of this paper is to propose a personalized safety training protocol that is delivered using robust, realistic and immersive environments. Design/methodology/approach Two types of virtual environments were developed: (1) Stereo-panoramic environments using real construction scenes that were used to evaluate the performance of trainees accurately and (2) A virtual construction site, which was used to deliver various elements of instructional training. A training protocol was then designed that was aimed at improving the hazard recognition and management performance of trainees. It was delivered using the developed virtual environments. The effectiveness of the training protocol was experimentally tested with 53 participants using a before–after study. Findings The results present a 39% improvement in hazard recognition and a 44% improvement in hazard management performance. Originality/value This study combines the benefits of using a virtual environment for providing instructional training along with realistic environments (stereo-panoramic scenes) for performance assessment and feedback. The training protocol includes several new and innovative training elements that are designed to improve the hazard recognition and hazard management abilities of the trainees. Moreover, the effectiveness of training in improving hazard recognition and hazard management is measured using specific outcome variables. DA - 2020/4/25/ PY - 2020/4/25/ DO - 10.1108/ECAM-07-2019-0391 VL - ahead-of-print IS - ahead-of-print UR - https://doi.org/10.1108/ECAM-07-2019-0391 KW - Construction safety KW - Safety training KW - Hazard recognition KW - Personalized training KW - VR ER - TY - JOUR TI - Establishing a Future-Proofing Framework for Infrastructure Projects to Proactively Adapt to Complex Regulatory Landscapes AU - Rasoulkhani, K. AU - Brannen, L. AU - Zhu, J. AU - Mostafavi, A. AU - Jaselskis, E. AU - Stoa, R. AU - Li, Q. AU - Alsharef, A. AU - Banerjee, S. AU - Chowdhury, S. T2 - Journal of Management in Engineering AB - Infrastructure projects experience different regulatory impacts during permitting, operations, and decommissioning. However, no framework is in place to provide a foundation for infrastructure operators and administrators to take advantage of the opportunities (e.g., gain competitive advantage) and cope with the risks (e.g., risk of noncompliance) related to regulatory requirements. This study aimed to identify the existing methodologies and emerging practices to proactively identify, evaluate, and respond to the impact of regulatory changes. To this end, an exploratory research approach was adopted, through which multiple field studies were conducted with interviewees from various functions and units of regulated entities as well as from regulatory agencies. Accordingly, this study established a future-proofing framework that enables companies operating in infrastructure sectors to more proactively respond to and comply with regulations during their projects. In general, the regulatory future-proofing framework encompasses two main components: (1) core subprocesses, which distinguish job sharing and specific responsibilities in dealing with regulatory changes; and (2) influencing factors, which represent overarching areas that make the subprocesses work more effectively. The framework was validated by experts and would enable companies to more effectively and proactively prepare for regulatory adaptation and response in infrastructure projects. DA - 2020/4/20/ PY - 2020/4/20/ DO - 10.1061/(asce)me.1943-5479.0000794 VL - 36 IS - 4 UR - http://dx.doi.org/10.1061/(asce)me.1943-5479.0000794 ER - TY - JOUR TI - Design For Six Sigma (DFSS) Approach for Creating CLEAR Lessons Learned Database T2 - Periodica Polytechnica Architecture AB - Project personnel working in construction sites fail to transfer invaluable experiences gained mostly due to the absence of a formalized process to record such information. Construction projects are seldom repetitive in nature and this highlights the need for organizations to have in place robust data repositories to facilitate knowledge sharing. This paper describes an effort in creating a new internal-only web-based lessons learned database named Communicate Lessons, Exchange Advice, Record (CLEAR) for the North Carolina Department of Transportation (NCDOT). A Design For Six Sigma (DFSS) approach of Identify, Define, Develop, Optimize, and Verify (IDDOV) model was used. Findings from this study will help NCDOT to institutionalize knowledge and improve project cost variations and schedule predictability. In conjunction with this database, a data dashboard is envisioned to provide effective visualizations for the upper management to make informed decisions based on the lessons information in the database. The dashboard will include success metrics such as detecting reduced numbers of claims and claims amounts, witnessing periodical increase in lessons uploaded into the database, and enhanced communication among specialized staff. This approach is a significant contribution to the existing body of knowledge in lessons learned database implementation for construction applications. The anticipated outcome of this new application will be a more efficient and effective public organization through reduced claims, improved designs, and construction workflows, and improved policies and standards. Future researchers can make use of information presented in this paper to build new robust lessons learned systems to improve organizational efficiency. DA - 2020/2/14/ PY - 2020/2/14/ DO - 10.3311/ppar.15442 UR - http://dx.doi.org/10.3311/ppar.15442 ER - TY - JOUR TI - A dissipated pseudo strain energy-based failure criterion for thermal cracking and its verification using thermal stress restrained specimen tests AU - Keshavarzi, Behrooz AU - Kim, Y. Richard T2 - CONSTRUCTION AND BUILDING MATERIALS AB - Low-temperature cracking is one of the most prevalent types of distress in asphalt concrete pavements in regions where the air temperature undergoes a significant daily drop. This paper proposes a failure criterion that correlates the dissipated pseudo strain energy (DPSE) at the time of failure with the reduced strain rate. Uniaxial direct tension monotonic tests, axial compression dynamic modulus tests, and direct tension cyclic fatigue tests were performed using the Asphalt Mixture Performance Tester (AMPT) for a wide range of asphalt mixtures with different reclaimed asphalt pavement (RAP) contents, binder contents, virgin binder performance grades, and aging levels. The results show that the simplified viscoelastic continuum damage (S-VECD) model, which is characterized by the dynamic modulus and cyclic fatigue test results, can predict the stress-strain behavior of a given mixture subjected to monotonic tests at different temperatures and loading rates. This finding allows the prediction of DPSE in monotonic tension tests using the S-VECD model. The thermal stress restrained specimen test (TSRST) was then used to verify the DPSE-based failure criterion and the ability of the S-VECD model to predict thermal fracture behavior. The study results show that the predicted fracture temperatures match the measured ones for the study mixtures with reasonable accuracy. The study also used data from mixtures whose RAP contents, binder contents, virgin binder grades, and aging levels were systematically altered to verify the reasonableness of the proposed procedure to evaluate the differences in thermal fracture performance that are due to changes in these factors. The ability to predict the fracture stress and fracture temperature measured via the TSRST using the S-VECD model and the suggested DPSE failure criterion is of substantial practical and technical importance because it allows the prediction of both fatigue cracking and thermal cracking using a single set of tests, i.e., AMPT dynamic modulus and cyclic fatigue tests. DA - 2020/2/10/ PY - 2020/2/10/ DO - 10.1016/j.conbuildmat.2019.117199 VL - 233 SP - SN - 1879-0526 KW - Thermal cracking KW - Low temperature KW - Failure criterion KW - Dissipated pseudo strain energy KW - Simplified viscoelastic continuum damage (S-VECD) KW - Asphalt Mixture Performance Tester (AMPT) KW - Thermal stress restrained specimen test (TSRST) KW - Reclaimed asphalt pavement (RAP) ER - TY - JOUR TI - An Assessment of the Dynamic Global Warming Impact Associated with Long-Term Emissions from Landfills AU - Wang, Yixuan AU - Levis, James W. AU - Barlaz, Morton A. T2 - ENVIRONMENTAL SCIENCE & TECHNOLOGY AB - Landfills are a major contributor of anthropogenic CH4 emissions. Since the greenhouse gas (GHG) emissions associated with landfilling waste can occur over decades to centuries, the standard static approach to estimating global warming impacts may not accurately represent the global warming impacts of landfills. The objective of this study is to assess the implications of using 100 yr and 20 yr static and dynamic global warming potential (GWP) approaches to estimate the global warming impacts from municipal solid waste landfills. A life-cycle model was developed to estimate GHG emissions for three gas treatment cases (passive venting, flare, CH4 conversion to electricity) and four decay rates. For the 100 yr GWP, other model uncertainties (e.g., static GWP values, decay rate, moisture content, or gas collection efficiency) generally had a larger effect on the estimated global warming impact than the choice of static versus dynamic GWP methods. This shows that when comparing single-point GWP values, the choice of static versus dynamic is relatively unimportant for most landfills. While dynamic GWPs consider temporal variance and provide useful estimates for the warming over a set time horizon, for most comparative analyses, static values provide reasonable bounds for the actual 100 yr warming impact. DA - 2020/2/4/ PY - 2020/2/4/ DO - 10.1021/acs.est.9b04066 VL - 54 IS - 3 SP - 1304-1313 SN - 1520-5851 ER - TY - JOUR TI - Analytical solutions for material line and plane in triple slip, with inverse solutions for the slips from a finite deformation experiment on iron crystals AU - Havner, Kerry S. T2 - INTERNATIONAL JOURNAL OF PLASTICITY AB - Triple-slip analytical solutions are derived for rotation and extension of crystal material lines and planes relative to the underlying lattice, applicable to any crystal class. An algebraic inverse solution is then developed for the amounts of slip on the three systems (two collinear) in terms of initial and final positions of material line and plane. The solutions are applied to a finite deformation experiment (from the recent literature) on a bcc iron crystal in uniaxial compression, considering both {110} and {112} slip-planes. The respective slips and areal and length changes are determined from the initial and final experimental positions of the compression plane and an edge line. Such analyses can assist in assessment of relative hardening rates of the slip systems. DA - 2020/2// PY - 2020/2// DO - 10.1016/j.ijplas.2019.08.018 VL - 125 SP - 280-293 SN - 1879-2154 KW - Triple slip KW - Finite deformation KW - Line and plane rotations KW - Analytical solutions KW - Iron crystals ER - TY - JOUR TI - Role of the air-water interface in removing perfluoroalkyl acids from drinking water by activated carbon treatment AU - Meng, Pingping AU - Jiang, Xiangzhe AU - Wang, Bin AU - Huang, Jun AU - Wang, Yujue AU - Yu, Gang AU - Cousins, Ian T. AU - Deng, Shubo T2 - JOURNAL OF HAZARDOUS MATERIALS AB - Contamination of drinking water by per- and polyfluoroalkyl substances (PFASs) is a worldwide problem. In this study, we for the first time revealed the role of the air-water interface in enhancing the removal of long-chain perfluoroalkyl carboxylic (PFCAs; CnF2n+1COOH, n ≥ 7) and perfluoroalkane sulfonic (PFSAs; CnF2n+1SO3H, n ≥ 6) acids, collectively termed as perfluoroalkyl acids (PFAAs), through combined aeration and adsorption on two kinds of activated carbon (AC). Aeration was shown to enhance the removal of long-chain PFAAs through adsorption at the air-water interface and subsequent adsorption of PFAA-enriched air bubbles to the AC. The removal of selected long-chain PFAAs was increased by 50–115 % with the assistance of aeration, depending on the perfluoroalkyl chain length. Aeration is more effective in enhancing long-chain PFAA removal as air-water interface adsorption increases with PFAA chain length due to higher surface activity. After removing adsorbed air bubbles by centrifugation, up to 80 % of the long-chain PFAAs were able to desorb from the sorbent, confirming the contribution of the air-water interface to the adsorption of PFAAs on AC. Aeration during AC treatment of water could enhance the removal of long-chain PFAAs, and improve the performance of AC during water treatment. DA - 2020/3/15/ PY - 2020/3/15/ DO - 10.1016/j.jhazmat.2019.121981 VL - 386 SP - SN - 1873-3336 KW - PFAAs KW - Air-water interface KW - Activated carbon KW - Aeration KW - Adsorption ER - TY - JOUR TI - Schedules and Schedulers: A Study in the US Construction Industry AU - Alves, Thais da C. L. AU - Liu, Min AU - Scala, Natalie M. AU - Javanmardi, Ashtad T2 - ENGINEERING MANAGEMENT JOURNAL AB - This research examines how the construction industry addresses the roles of schedulers and schedules, with the goal of improving current practices. We use a mixed-mode approach of qualitative and quantitative data regarding the use of schedules and the role of schedulers in construction. Through influence diagrams and statistical analyses, we discover seven themes in the data and identify corresponding industry challenges related to each theme. Themes include the dynamic nature of schedules, changes in schedule level of detail throughout the life cycle, differences between planning and scheduling, and the evolving roles of schedulers. Based on in-depth discussions with a focus group and examining a large cross section of professionals in a nationwide survey, we propose recommendations to increase collaboration when developing schedules and to improve the roles of schedulers. DA - 2020/7/2/ PY - 2020/7/2/ DO - 10.1080/10429247.2020.1738878 VL - 32 IS - 3 SP - 166-185 SN - 2377-0643 KW - Scheduling KW - Construction KW - Planning KW - Schedulers KW - US Construction Industry KW - Project Management KW - Operations Management ER - TY - JOUR TI - Safety effects of parking maneuvers AU - Findley, Daniel J. AU - Nye, Timothy S. AU - Lattimore, Elizabeth AU - Swain, Graham AU - Bhat, Sharath Kumar Parameshwar AU - Foley, Burke T2 - TRANSPORTATION RESEARCH PART F-TRAFFIC PSYCHOLOGY AND BEHAVIOUR AB - Parking maneuvers, particularly a vehicle’s maneuver for entering and leaving a parking space, have varying rates of use and safety impacts. In this effort, crash data were collected for parking lots in the vicinity of a university campus and compared to observational parking position data. The campus was selected for this study because a change in the parking enforcement process was expected to (and did) change parking maneuver choices. When entering and leaving a parking space, three maneuver options exist for drivers: (1) forward, (2) reverse, and (3) pulling through an adjacent parking space. When specifically entering a parking space, the maneuver options become: (1) pull-in, (2) back-in, and (3) pull-through. When leaving the parking space, the maneuver options become: (1) pull-out, (2) back-out, and (3) pull-through. This study found that the pull-in/back-out vehicle maneuver’s percentage of total crashes was greater than the percentage of vehicles that were actually observed to use the same maneuver. The analysis from this study implies that the pull-in/back-out parking maneuver is more likely to result in a collision and therefore, is associated with a higher crash risk. Further analysis of North Carolina’s parking related fatal and serious injury crashes found that vehicles backing out of parking spaces was overwhelmingly the main cause for these serious injuries. 90% of North Carolina’s parking related fatal and serious injuries occurred during a back-out maneuver. Overall, this study concludes that the back-in/pull-out parking maneuver is safer than the pull-in/back-out maneuver and is the recommended approach to 90° parking. DA - 2020/2// PY - 2020/2// DO - 10.1016/j.trf.2020.02.002 VL - 69 SP - 301-310 SN - 1873-5517 KW - Parking KW - Policy KW - Driver behavior KW - Urban design KW - Backover KW - Parking maneuver ER - TY - JOUR TI - Strength and Durability Characteristics of Cement-Sand Stabilized Earth Blocks AU - Islam, Mohammad Shariful AU - Tausif-E-Elahi AU - Shahriar, Azmayeen Rafat AU - Nahar, Kamrun AU - Hossain, Tahsin Reza T2 - JOURNAL OF MATERIALS IN CIVIL ENGINEERING AB - Conventional building materials like fired clay brick (FCB) and concrete blocks are expensive and, in some cases, have detrimental effect on environment. Compressed stabilized earth block (CSEB) can be an effective alternative that can be easily prepared from locally available clays with little addition of stabilizers. This study is carried out to assess the performance of CSEBs prepared of highly fine-grained soils as a suitable construction material. As such, both stabilized and unstabilized earth blocks were tested and a comparative assessment is made in terms of compressive strength, unit weight, durability, and load-deformation characteristics. Varying proportions of cement, coarse sand (CS), and fine sand (FS) were used in a quest to find an optimum combination for producing CSEB that meet the design criteria outlined in several standards. Inclusion of 50%–60% CS is found to provide maximum density and compressive strength, and beyond 60% CS content, strength begins to drop. CSEBs made with cement ≥6% with proper amount of sand showed better durability. Although addition of mixed sand (CS and FS) was found to be more effective in increasing strength; however, durability was poor. With the increase of cement, water absorption was found to decrease. CSEBs with cement content ≥6% and coarse sand >40% showed water absorption of less than 15%. Moreover, with the increase of cement content, peak stress increases and failure strain decreases, resulting in brittle nature of the material. Some interesting stress–strain response was observed for different cement content at a constant CS content, directing to a conclusive solution. Taking the aforementioned parameters into consideration, optimum proportions of cement, CS, and FS to achieve considerable strength and durability was suggested. Finally, a cost analysis was performed and the prospect of CSEBs as an eco-friendly, and sustainable alternative to conventional masonry units like FCBs was presented. DA - 2020/5/1/ PY - 2020/5/1/ DO - 10.1061/(ASCE)MT.1943-5533.0003176 VL - 32 IS - 5 SP - SN - 1943-5533 KW - Cement stabilized earth block KW - Compressive strength KW - Durability KW - Clayey soil KW - Unit weight KW - Stress-strain response ER - TY - JOUR TI - Relations between colloidal indices and low-temperature properties of reclaimed binder modified with softer binder, oil-rejuvenator and polybutadiene rubber AU - Mansourkhaki, Ali AU - Ameri, Mahmoud AU - Habibpour, Mandi AU - Underwood, B. Shane T2 - CONSTRUCTION AND BUILDING MATERIALS AB - Asphalt binder properties play an important role in the behavior of asphalt concrete pavements at low temperature and should be studied using laboratory tests. This research investigates the relationship between chemical properties and low-temperature performance of asphalt binders at RAP contents of 15%, 30%, 50 and 100% by weight. The asphalt is also modified with a softer binder, oil rejuvenator and polybutadiene rubber (PBR 1220) modified binder. Binder testing includes penetration test, softening point, bending beam rheometer (BBR) and Fraass breaking point. Moreover, saturate, aromatic, resin, and asphaltene (SARA) fractionation is used to study the induced changes in the chemical composition of binders after adding RAP. The results show that binders modified with oil-rejuvenator have better resistance to low temperature cracking in comparison with softer binder and polymer modified binder (PMB), particularly at high percentages of RAP. Using a softer virgin binder also demonstrates improvements in the low-temperature performance of RAP binder. Moreover, PBR 1220 blended with RAP binder showed poor resistance to low-temperature cracking, it means that having a low Tg (for polymer) would not necessarily lead to a good low temperature cracking of the polymer-modified binder. Finally, some promising statistical correlations are found between colloidal indices and low-temperature performance of samples with RAP content. DA - 2020/4/10/ PY - 2020/4/10/ DO - 10.1016/j.conbuildmat.2019.117800 VL - 239 SP - SN - 1879-0526 KW - Binder KW - Low-temperature performance KW - Bending beam rheometer KW - Fraass breaking point KW - Fractionation ER - TY - JOUR TI - An Integrated UGV-UAV System for Construction Site Data Collection T2 - Automation in Construction AB - There have been recent efforts to increase the degree of automation and frequency of data collection for construction applications using Unmanned Aerial/Ground Vehicles (UAV/UGV). However, the current practice of data collection is traditionally performed, which is manual, costly, time-consuming, and error-prone. Developing vision-based mobile robotic systems that are aware of its surrounding and capable of autonomous navigation are becoming essential to many construction applications, namely surveying, monitoring, and inspection. Nevertheless, the systems above suffer from a series of performance issues. One major problem is inefficient navigation in indoor and cluttered scenes with many obstacles and barriers, where some places are inaccessible by a UGV. To provide a solution to this problem, this paper designs a UAV-UGV team that integrates two custom-built mobile robots. The UGV autonomously navigates through space, leveraging its sensors. The UAV acts as an external eye for the UGV, observing the scene from a vantage point that is inaccessible to the UGV. The relative pose of the UAV is estimated continuously, which allows it to maintain a fixed location that is relative to the UGV. The key aspects for the development of this system that is capable of autonomous navigation are the localization of both UAV and UGV, mapping of the surrounding environment, and efficient path planning using multiple sensors. The proposed system is tested in an indoor and cluttered construction-like environment. The performance of the system demonstrates the feasibility of developing and deploying a robust and automated data collection system for construction applications in the near future. DA - 2020/4// PY - 2020/4// DO - 10.1016/j.autcon.2019.103068 UR - http://dx.doi.org/10.1016/j.autcon.2019.103068 ER - TY - JOUR TI - Development of environmentally friendly flame retardant to achieve low flammability for asphalt binder used in tunnel pavements AU - Sheng, Yanping AU - Wu, Yongchang AU - Yan, Yu AU - Jia, Haichuan AU - Qiao, Yunyan AU - Underwood, B. Shane AU - Niu, Dongyu AU - Kim, Y. Richard T2 - JOURNAL OF CLEANER PRODUCTION AB - This paper reports the development of an environmentally friendly flame retardant, referred to as FRC-Si, to improve the fire resistance of asphalt binder without compromising mixture performance. This flame-retardant composite (FRC) contains four halogen-free flame-retardant components: expandable graphite (EG), magnesium hydroxide (MH), calcium hydroxide (CH), and ammonium polyphosphate (APP). These four components have different ranges of thermal reaction temperature so they can effectively absorb heat throughout the entire process of binder combustion. An orthogonal experiment with six binder properties as the influential factors was designed for this study. Then, a multi-criteria decision analysis method was employed to find the optimal proportion of the combined EG, MH, CH, and APP to be 5:5:4:9, respectively. A silane coupling agent was added to modify the surface properties and improve stability of the asphalt binder, thereby transforming the preliminary FRC to FRC-Si. Based on activation index values and oil absorption of the binder, the optimum content of the silane coupling agent was determined to be 1.2% by mass of FRC. In addition, the rheological properties and flammability of styrene-butadiene-styrene (SBS) binder with various dosages of FRC-Si were obtained and the optimum content of FRC-Si was determined to be 8% by mass of binder. Finally, cone calorimeter tests were performed to evaluate the flame retardancy of asphalt mixtures with SBS, FRC, and FRC-Si binders. Results indicate that FRC-Si not only reduced the amounts of heat and carbon monoxide (CO) released, but also delayed the release of CO, thereby supporting the application of FRC-Si as a flame retardant for asphalt pavements in tunnels. DA - 2020/6/1/ PY - 2020/6/1/ DO - 10.1016/j.jclepro.2020.120487 VL - 257 SP - SN - 1879-1786 KW - Asphalt binder KW - Halogen-free KW - Flame-retardant KW - Orthogonal experiment KW - Heat release rate KW - Carbon monoxide KW - Silane coupling agent ER - TY - JOUR TI - Incorporating Worker Awareness in the Generation of Hazard Proximity Warnings AU - Chan, Kelsey AU - Louis, Joseph AU - Albert, Alex T2 - SENSORS AB - Proximity warning systems for construction sites do not consider whether workers are already aware of the hazard prior to issuing warnings. This can generate redundant and distracting alarms that interfere with worker ability to adopt timely and appropriate avoidance measures; and cause alarm fatigue, which instigates workers to habitually disable the system or ignore the alarms; thereby increasing the risk of injury. Thus, this paper integrates the field-of-view of workers as a proxy for hazard awareness to develop an improved hazard proximity warning system for construction sites. The research first developed a rule-based model for the warning generation, which was followed by a virtual experiment to evaluate the integration of worker field-of-view in alarm generation. Based on these findings, an improved hazard proximity warning system incorporating worker field-of-view was developed for field applications that utilizes wearable inertial measurement units and localization sensors. The system’s effectiveness is illustrated through several case studies. This research provides a fresh perspective to the growing adoption of wearable sensors by incorporating the awareness of workers into the generation of hazard alarms. The proposed system is anticipated to reduce unnecessary and distracting alarms which can potentially lead to superior safety performance in construction. DA - 2020/2// PY - 2020/2// DO - 10.3390/s20030806 VL - 20 IS - 3 SP - SN - 1424-8220 KW - construction safety KW - hazard proximity KW - sensors KW - worker awareness KW - automated warnings ER - TY - JOUR TI - Statistical Validation of Crowdsourced Pavement Ride Quality Measurements from Smartphones AU - Medina, Jose R. AU - Noorvand, Hossein AU - Underwood, B. Shane AU - Kaloush, Kamil T2 - JOURNAL OF COMPUTING IN CIVIL ENGINEERING AB - Advances in computing capabilities, image processing, and sensing technologies have permitted the development of specialized vehicles equipped with the capability to assess pavement condition at normal operating speeds. This has greatly improved engineers’ ability to assess and manage pavements, but the equipment is costly, and not all agencies can afford to purchase it. Recently, researchers have developed smartphone applications to address this data collection problem, but most of this work focused on a restricted setup, or calibration. This paper presented a methodology to estimate a ride quality index (RQI) from crowdsourced smartphone measurements and validated this approach with the use of statistical methods. This investigation was divided into three phases. First, a mechanical model to assess ride quality was developed. Second, the Monte Carlo method and the probabilistic point estimate were adopted to simulate RQI measurement responses to different longitudinal profiles from different vehicle traffic spectra. Third, the effects of wander and multilane effects in estimating the minimum required sample size for RQI measurements to converge were evaluated. Once the mechanical model was developed, the results from the Monte Carlos simulations showed that in 83% of cases, the RQI measurements showed no statistical significance. The results from the effect of multilane and wandering effects showed that the sample size for RQI measurements to converge adopting a coefficient of variation of 2% is 400 samples considering a single lane and wander, and 435 samples considering two lanes and wander. The use of the Monte Carlo method successfully validated the crowdsourced smartphone-based RQI measurements as an alternative method to evaluate pavement condition. This approach has the potential to save transportation agencies millions of dollars in pavement condition surveys and to give a better sense of pavement condition in real time. DA - 2020/5/1/ PY - 2020/5/1/ DO - 10.1061/(ASCE)CP.1943-5487.0000891 VL - 34 IS - 3 SP - SN - 1943-5487 KW - International roughness index (IRI) KW - Smartphones KW - Pavement condition KW - Monte Carlo method KW - InfoPave KW - Crowdsourcing ER - TY - JOUR TI - Binary Building Attribute Imputation, Evaluation, and Comparison Approaches for Hurricane Damage Data Sets AU - Massarra, Carol C. AU - Friedland, Carol J. AU - Marx, Brian D. AU - Dietrich, J. Casey T2 - Journal of Performance of Constructed Facilities AB - Missing building attributes are problematic for development of data-based fragility models. Relative to other disciplines, the application of imputation techniques is limited in the field of engineering. Current imputation techniques to replace missing building attributes lack evaluations of imputation model performance, which ensure accuracy and validity of the imputed data. This paper presents two imputation approaches, along with imputation diagnostic and comparison approaches, for binary building attribute data with missing observations. Predictive mean matching (PMM) and multiple imputation (MI) are used to impute foundation type and number of stories attributes. The diagnostic approach, based on the logistic regression goodness-of-fit test, is used to evaluate the imputation model fit. The comparison approach, based on the percentage of correctly imputed observations, is used to evaluate the imputation model performance. A data set of single-family homes damaged by the 2005 Hurricane Katrina is used to demonstrate implementation of the methodology. Based on the comparison approach, PMM models showed 9% and 2% greater accuracy than MI models in imputing foundation type and number of stories, respectively. DA - 2020/6// PY - 2020/6// DO - 10.1061/(ASCE)CF.1943-5509.0001433 VL - 34 IS - 3 SP - 04020036 UR - https://doi.org/10.1061/(ASCE)CF.1943-5509.0001433 KW - Imputation techniques KW - Binary missing data KW - Diagnostic approach KW - Comparison approach ER - TY - JOUR TI - Smart Infrastructure: A Vision for the Role of the Civil Engineering Profession in Smart Cities AU - Berglund, Emily Zechman AU - Monroe, Jacob G. AU - Ahmed, Ishtiak AU - Noghabaei, Mojtaba AU - Do, Jinung AU - Pesantez, Jorge E. AU - Khaksar Fasaee, Mohammad Ali AU - Bardaka, Eleni AU - Han, Kevin AU - Proestos, Giorgio T. AU - Levis, James T2 - Journal of Infrastructure Systems AB - Smart city programs provide a range of technologies that can be applied to solve infrastructure problems associated with ageing infrastructure and increasing demands. The potential for infrastructure and urban improvement remains unrealized, however, due to technical, financial, and social constraints and criticisms that limit the implementation of smart cities concepts for infrastructure management. The discussion presented here provides a review of smart technologies including sensors, crowdsourcing and citizen science, actuators, data transmission, Internet of Things, big data analytics, data visualization, and blockchain, which can be used for infrastructure management. Smart infrastructure programs are reviewed to explore how enabling technologies have been applied across civil engineering domains, including transportation systems, water systems, air quality, energy infrastructure, solid waste management, construction engineering and management, structures, and geotechnical systems. Gaps in the application of smart technologies for infrastructure systems are identified, and we highlight how the civil engineering profession can adopt new roles toward the development of smart cities applications. These roles are: (1) master designer: civil engineers can identify ready applications of enabling technologies to improve the delivery of urban resources and services; (2) steward: civil engineers must account for both the environmental and societal impacts of smart infrastructure applications; (3) innovator and integrator: civil engineers should integrate across diverse sectors and groups of experts to develop smart infrastructure programs; (4) manager of risk: civil engineers should manage existing and growing risks of natural disasters, emergencies, and climate change; they should also manage new vulnerabilities in the privacy and security of individuals and households that are introduced through smart technologies; and (5) leader and decision maker: civil engineers can take a lead in smart infrastructure discussions and policy development. DA - 2020/6// PY - 2020/6// DO - 10.1061/(ASCE)IS.1943-555X.0000549 VL - 26 IS - 2 SP - 03120001 J2 - J. Infrastruct. Syst. LA - en OP - SN - 1076-0342 1943-555X UR - http://dx.doi.org/10.1061/(ASCE)IS.1943-555X.0000549 DB - Crossref ER - TY - JOUR TI - Ruminant Fecal Contamination of Drinking Water Introduced Post-Collection in Rural Kenyan Households AU - Hamzah, Latifah AU - Boehm, Alexandria B. AU - Davis, Jennifer AU - Pickering, Amy J. AU - Wolfe, Marlene AU - Mureithi, Maryanne AU - Harris, Angela T2 - INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH AB - In sub-Saharan Africa, many families travel to collect water and store it in their homes for daily use, presenting an opportunity for the introduction of fecal contamination. One stored and one source water sample were each collected from 45 households in rural Kenya. All 90 samples were analyzed for fecal indicator bacteria (E. coli and enterococci) and species-specific contamination using molecular microbial source tracking assays. Human (HF183), avian (GFD), and ruminant (BacR) contamination were detected in 52, two, and four samples, respectively. Stored water samples had elevated enterococci concentrations (p < 0.01, Wilcoxon matched pairs test) and more frequent BacR detection (89% versus 27%, p < 0.01, McNemar’s exact test) relative to source water samples. fsQCA (fuzzy set qualitative comparative analysis) was conducted on the subset of households with no source water BacR contamination to highlight combinations of factors associated with the introduction of BacR contamination to stored water supplies. Three combinations were identified: (i) ruminants in the compound, safe water extraction methods, and long storage time, (ii) ruminants, unsafe water extraction methods, and no soap at the household handwashing station, and (iii) long storage time and no soap. This suggests that multiple pathways contribute to the transmission of ruminant fecal contamination in this context, which would have been missed if data were analyzed using standard regression techniques. DA - 2020/1/2/ PY - 2020/1/2/ DO - 10.3390/ijerph17020608 VL - 17 IS - 2 SP - SN - 1660-4601 KW - microbial source tracking KW - fuzzy set qualitative comparative analysis KW - stored water KW - source water KW - fecal bacteria KW - ruminant contamination ER - TY - JOUR TI - Effect of repeated rise and fall of water level on seepage-induced deformation and related stability analysis of Princeville levee AU - Jadid, Rowshon AU - Montoya, Brina M. AU - Bennett, Victoria AU - Gabr, Mohammed A. T2 - ENGINEERING GEOLOGY AB - The Princeville levee, and flooding associated with Hurricanes Floyd and Matthew, is used as a case study in which the analyses are focused on the effect of repeated rise and fall of water levels (representing severe storm cycles) on the stability of the levee and the risk of failure. The analyses included strain-based and strength reduction approaches and are conducted using the finite element program Plaxis 2D. The limit equilibrium stability software “Slope/W” was also used for comparative study. The strain-based limit state approach considers the uncertainty of soil properties and is used to characterize the levee performance under repeated storm loading in terms of damage levels (or limit states). The strain-based analyses results show a progressive development of plastic shear strain zone within the levee as the number of storm cycles is increased. The accumulation of such shear strain leads to increasing the probability of exceeding a given performance limit state. As more flooding cycles are introduced, the shear strain values increase by a factor of 3.5 from cycle 1 to 6, and therefore reflect the increasing level of failure risk. In parallel, the deterministic stability factor of safety obtained from limit equilibrium method remains unchanged and slightly changes for strength reduction method with an increased number of rises and falls of the water level. The consideration of “rapid” drawdown conventionally used in limit equilibrium stability analyses (where no consideration for time is included), instead of more realistic rate based on drawdown hydrograph leads to conservative estimate of factor of safety. The analyses results demonstrate the increase in risk with repeated hydraulic loading. DA - 2020/3/5/ PY - 2020/3/5/ DO - 10.1016/j.enggeo.2019.105458 VL - 266 SP - SN - 1872-6917 KW - Slope stability KW - Limit state KW - Levee KW - Embankment dam KW - Probability of failure KW - Rapid drawdown ER - TY - JOUR TI - Technical Note: Evaluation of the skill in monthly-to-seasonal soil moisture forecasting based on SMAP satellite observations over the southeastern US AU - Mazrooei, Amirhossein AU - Sankarasubramanian, Arumugam AU - Lakshmi, Venkat T2 - Hydrology and Earth System Sciences AB - Abstract. Providing accurate soil moisture (SM) conditions is a critical step in model initialization in weather forecasting, agricultural planning, and water resources management. This study develops monthly-to-seasonal (M2S) top layer SM forecasts by forcing 1- to 3-month-ahead precipitation forecasts with Noah3.2 Land Surface Model. The SM forecasts are developed over the southeastern US (SEUS), and the SM forecasting skill is evaluated in comparison with the remotely sensed SM observations collected by the Soil Moisture Active Passive (SMAP) satellite. Our results indicate potential in developing real-time SM forecasts. The retrospective 18-month (April 2015–September 2016) comparison between SM forecasts and the SMAP observations shows statistically significant correlations of 0.62, 0.57, and 0.58 over 1-, 2-, and 3-month lead times respectively. DA - 2020/3/5/ PY - 2020/3/5/ DO - 10.5194/hess-24-1073-2020 VL - 24 IS - 3 SP - 1073-1079 J2 - Hydrol. Earth Syst. Sci. LA - en OP - SN - 1607-7938 UR - http://dx.doi.org/10.5194/hess-24-1073-2020 DB - Crossref ER - TY - JOUR TI - A Framework for Simulation-Based Internal Flooding Risk Assessment AU - Dubey, Ankit R. AU - Gupta, Abhinav AU - Coleman, Justin T2 - JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME AB - Abstract Internal flooding due to pipe breaks can interfere with a plant's ability to safely shut down or maintain the decay heat removal. Flooding simulation tools require information on location of pipe breaks and the degree of damage at each location as input for assessing the flooding risk. This can be especially challenging as the number of potential leakage locations are quite large and the state-of-the-art simulation tools cannot determine the degree of damage at a location. This paper presents a novel simulation-based framework that can be used to determine seismically induced flooding scenarios including the potential locations of leakage and the degree of leakage at each location. The proposed framework builds upon a few recent experimental and simulation-based studies on piping fragilities. This research identifies that a direct use of piping fragility information by flooding simulation tools is not appropriate. This paper presents a new approach that creates mutually exclusive and collectively exhaustive events to characterize the complete sample space at each location and employs the total probability theorem to characterize the probabilities for each event in this space. This paper also identifies the importance of including the temporal effects in the piping fragilities in order to allow a more realistic simulation of internal flooding scenarios. DA - 2020/2/1/ PY - 2020/2/1/ DO - 10.1115/1.4045028 VL - 142 IS - 1 SP - SN - 1528-8978 KW - internal flooding KW - piping fragility KW - threaded T-joint ER - TY - JOUR TI - Assessing the Effectiveness of Point-of-Use Residential Drinking Water Filters for Perfluoroalkyl Substances (PFASs) AU - Herkert, Nicholas J. AU - Merrill, John AU - Peters, Cara AU - Bollinger, David AU - Zhang, Sharon AU - Hoffman, Kate AU - Ferguson, P. Lee AU - Knappe, Detlef R. U. AU - Stapleton, Heather M. T2 - ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS AB - Per- and polyfluoroalkyl substances (PFASs) have come under increased scrutiny due to concerns about their potential toxicity and prevalence in the environment, particularly drinking water. PFASs are difficult to remove in full-scale water treatment systems because of their physicochemical properties. Here we evaluated the effectiveness of point-of-use (POU) and point-of-entry (POE) residential drinking water filters in removing a suite of three perfluoroalkyl sulfonic acids, seven perfluoroalkyl carboxylic acids, and six per- and polyfluoroalkyl ether acids in homes in central (n = 61) and southeastern (n = 12) North Carolina. POU systems included countertop and pitcher filters, faucet-mounted filters, activated carbon block refrigerator filters, activated carbon block under-sink filters, under-sink dual-stage filters, and under-sink reverse osmosis filters. All under-sink dual-stage and reverse osmosis filters tested showed near complete removal for all PFASs evaluated. In contrast, all other filters containing activated carbon exhibited variable PFAS removal. In these filters, PFAS removal efficiency was dependent on chain length, with long-chain PFASs (∼60–70% removal) being more efficiently removed than short-chain PFASs (∼40% removal). A few whole-house activated carbon POE systems (n = 8) were also evaluated; however, results were variable, and in some cases (four of eight systems), increased PFAS levels were observed in the filtered water. DA - 2020/3// PY - 2020/3// DO - 10.1021/acs.estlett.0c00004 VL - 7 IS - 3 SP - 178-184 SN - 2328-8930 UR - https://doi.org/10.1021/acs.estlett.0c00004 ER - TY - JOUR TI - Nondestructive length estimation of an embedded pile through combined analysis of transverse and longitudinal waves AU - Samu, Vivek AU - Guddati, Murthy T2 - NDT & E INTERNATIONAL AB - This paper presents an important modification of the recently developed nondestructive testing method for estimating embedded depth of pile foundations – EDAR – effective dispersion analysis of reflections. The original EDAR method is based on processing dispersive bending wave signals in the frequency-effective wavenumber domain, thus eliminating the need to perform time-domain peak picking that is difficult due to over-distortion of reflected signals. While EDAR was successful in laboratory settings, preliminary field validation resulted in significant errors. After careful examination of the wave physics, it is discovered that both longitudinal and transverse waves need to be carefully included in EDAR analysis. Specifically, it is shown that the initial arrival is dominated by transverse waves, while the reflections are dominated by longitudinal waves, owing to significant attenuation of transverse waves due to compacted soil around the pile. This observation led to a refined EDAR methodology and accurate estimation of embedded pile depth in field settings. DA - 2020/3// PY - 2020/3// DO - 10.1016/j.ndteint.2019.102203 VL - 110 SP - SN - 1879-1174 KW - Lateral impact KW - Attenuation KW - Unknown foundation KW - Reflection KW - Soil ER - TY - JOUR TI - GAC to BAC: Does it make chloraminated drinking water safer? AU - Cuthbertson, Amy A. AU - Kimura, Susana Y. AU - Liberatore, Hannah K. AU - Knappe, Detlef R. U. AU - Stanford, Benjamin AU - Summers, R. Scott AU - Dickenson, Eric R. AU - Maness, J. Clark AU - Glover, Caitlin AU - Selbes, Meric AU - Richardson, Susan D. T2 - WATER RESEARCH AB - Biological activated carbon (BAC) is widely used as a polishing step at full-scale drinking water plants to remove taste and odor compounds and assimilable organic carbon. BAC, especially with pre-ozonation, has been previously studied to control regulated disinfection by-products (DBPs) and DBP precursors. However, most previous studies only include regulated or a limited number of unregulated DBPs. This study explored two full-scale drinking water plants that use pre-chloramination followed by BAC and chloramine as the final disinfectant. While chloramine generally produces lower concentrations of regulated DBPs, it may form increased levels of unregulated nitrogenous and iodinated DBPs. We evaluated 71 DBPs from ten DBP classes including haloacetonitriles, haloacetamides, halonitromethanes, haloacetaldehydes, haloketones, iodinated acetic acids, iodinated trihalomethanes, nitrosamines, trihalomethanes, and haloacetic acids, along with speciated total organic halogen (total organic chlorine, bromine and iodine) across six different BAC filters of increasing age. Most preformed DBPs were well removed by BAC with different ages (i.e., operation times). However, some preformed DBPs were poorly removed or increased following treatment with BAC, including chloroacetaldehyde, dichloronitromethane, bromodichloronitromethane, N-nitrosodimethylamine, dibromochloromethane, tribromomethane, dibromochloroacetic acid, and tribromoacetic acid. Some compounds, including dibromoacetaldehyde, bromochloroacetamide, and dibromoacetamide, were formed only after treatment with BAC. Total organic halogen removal was variable in both plants and increases in TOCl or TOI were observable on one occasion at each plant. While calculated genotoxicity decreased in all filters, decreases in overall DBP formation did not correlate with decreases in calculated cytotoxicity. In three of the six filters, calculated toxicity increased by 4-27%. These results highlight that DBP concentration alone may not always provide an adequate basis for risk assessment. DA - 2020/4/1/ PY - 2020/4/1/ DO - 10.1016/j.watres.2019.115432 VL - 172 SP - SN - 0043-1354 KW - Biological activated carbon KW - Drinking water KW - Disinfection by-products KW - GAC KW - Total organic halogen KW - Calculated cytotoxicity & genotoxicity ER - TY - JOUR TI - Nonlinear Viscoelastic Response of Crumb Rubber Modified Asphalt Binder Under Large Strains AU - Gulzar, Saqib AU - Underwood, B. Shane T2 - TRANSPORTATION RESEARCH RECORD AB - Agencies have been increasing their use of polymer modified asphalt binders in recent years to address performance issues and lengthen the useful life of their pavements. When deployed these materials likely experience strain levels exceeding their linear viscoelastic (LVE) limits. The same situation exists in non-polymer modified asphalt binders as well, but the effect may be more pronounced in polymer modified systems because of their bi-phasic nature. In this study, terminally blended crumb rubber (CR-TB) modified asphalt is studied to understand and quantify the nonlinear viscoelastic response under large strains. The CR-TB binders are extensively used in pavements subjected to high vehicular loads and extreme climatic conditions; thereby, their response under large strains becomes more critical. The current standard characterization techniques are based on LVE response using small amplitude oscillatory shear rheology only and do not consider the behavior of binders under large strains. In this study, large amplitude oscillatory shear (LAOS) rheology is used as a framework to more thoroughly investigate the complete response of the CR-TB modified asphalt binder under large strains at 30°C, 40°C, 50°C, and 60°C and at the frequencies of 0.5, 1, and 5 Hz. The LAOS response is analyzed using Fourier-transform rheology and the orthogonal stress decomposition method involving Chebyshev polynomial representation. It is found that nonlinearity manifests greatly in this study material as strain levels increase and frequencies decrease. The relative nonlinearity increases with increasing strain amplitude and is more significant towards lower end of the tested temperature range. The CR-TB binder shows strain-stiffening/softening and shear-thinning/thickening behavior depending upon a specific temperature, strain level, and frequency. DA - 2020/3// PY - 2020/3// DO - 10.1177/0361198120907097 VL - 2674 IS - 3 SP - 139-149 SN - 2169-4052 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85085990773&partnerID=MN8TOARS ER - TY - JOUR TI - Chemical Composition and Rheological Characteristics of Binders Containing RAP and Rejuvenator AU - Mansourkhaki, A. AU - Ameri, M. AU - Habibpour, M. AU - Underwood, B.S. T2 - Journal of Materials in Civil Engineering AB - One of the most important concerns in using different additives for improving fatigue and low-temperature cracking resistance is the diminishing rutting resistance of pavement. In this research, saturates, aromatics, resins, and asphaltenes (SARA)-separation, dynamic shear rheometer (DSR), multiple stress creep recovery (MSCR), and bending beam rheometer (BBR) tests were conducted to study the interaction between chemical components and rheological behavior of binders with 25, 50, and 100 percentages of reclaimed asphalt pavement (RAP) binder modified with a softer binder and rejuvenator. The results show that the use of general guidelines for RAP content that do not consider the specific properties of all component materials in use has major limitations. The parameters obtained from rheological tests correlate positively with the asphaltene content. Using just asphaltene content as an index is more reliable than using Gastel and Asphaltene indices for investigating the effect of aging or adding an aged binder because its correlation with MSCR parameters is stronger. In this research, it also discovered that 100% of RAP content could be replaced in the case of an oil rejuvenator addition. DA - 2020/4// PY - 2020/4// DO - 10.1061/(ASCE)MT.1943-5533.0003016 VL - 32 IS - 4 SP - 04020026 SN - 1943-5533 KW - Asphaltenes KW - SARA-separation KW - Rheological properties KW - Chemical properties KW - Asphalt binder ER - TY - JOUR TI - Improving Effectiveness of Constraints Removal in Construction Planning Meetings: Information-Theoretic Approach AU - Javanmardi, Ashtad AU - Abbasian-Hosseini, S. Alireza AU - Liu, Min AU - Hsiang, Simon M. T2 - JOURNAL OF CONSTRUCTION ENGINEERING AND MANAGEMENT AB - Timely identification and removal of constraints is critical for improving workflow reliability. Construction project managers need to spend a significant amount of working time in various types of planning meetings to discuss, analyze, and remove constraints. However, the amount of uncertainty associated with each constraint, mutual information shared among constraints, and any information gained by addressing those constraints are not necessarily known with any great accuracy or precision. This research used a bridge construction project as a case study to collect empirical data on detailed weekly meeting minutes over 18 weeks and the planned and actual starting and finish times of 475 activities. An information-theoretic approach was used to develop a framework to measure the amount of uncertainty and information sharing among constraint discussions. A Chow–Liu tree was then developed to help project managers optimize the sequence of topics discussed so that meeting time may be spent more productively. Results from this particular study indicate that weekly planning meetings need to strategically address issues of equipment availability, design and working method clarification, and prerequisite work readiness since removing those constraints could improve workflow reliability by 5.6%, 4.9%, and 3.6%, respectively. The contribution to the body of knowledge of this research was the development of a framework to utilize an information theoretic–based approach to measure information exchange, uncertainty, and sharing in construction planning meetings. The method can be applied to other construction projects, and the findings can help project managers plan and run meetings more effectively. DA - 2020/4/1/ PY - 2020/4/1/ DO - 10.1061/(ASCE)CO.1943-7862.0001790 VL - 146 IS - 4 SP - SN - 1943-7862 ER - TY - JOUR TI - Trend Analysis on Adoption of Virtual and Augmented Reality in the Architecture, Engineering, and Construction Industry AU - Noghabaei, Mojtaba AU - Heydarian, Arsalan AU - Balali, Vahid AU - Han, Kevin T2 - Data AB - With advances in Building Information Modeling (BIM), Virtual Reality (VR) and Augmented Reality (AR) technologies have many potential applications in the Architecture, Engineering, and Construction (AEC) industry. However, the AEC industry, relative to other industries, has been slow in adopting AR/VR technologies, partly due to lack of feasibility studies examining the actual cost of implementation versus an increase in profit. The main objectives of this paper are to understand the industry trends in adopting AR/VR technologies and identifying gaps within the industry. The identified gaps can lead to opportunities for developing new tools and finding new use cases. To achieve these goals, two rounds of a survey at two different time periods (a year apart) were conducted. Responses from 158 industry experts and researchers were analyzed to assess the current state, growth, and saving opportunities for AR/VR technologies for the AEC industry. The findings demonstrate that older generations are significantly more confident about the future of AR/VR technologies and they see more benefits in AR/VR utilization. Furthermore, the research results indicate that Residential and commercial sectors have adopted these tools the most, compared to other sectors and institutional and transportation sectors had the highest growth from 2017 to 2018. Industry experts anticipated a solid growth in the use of AR/VR technologies in 5 to 10 years, with the highest expectations towards healthcare. Ultimately, the findings show a significant increase in AR/VR utilization in the AEC industry from 2017 to 2018. DA - 2020/3/13/ PY - 2020/3/13/ DO - 10.3390/data5010026 VL - 5 IS - 1 SP - 26 UR - https://doi.org/10.3390/data5010026 KW - virtual reality KW - augmented reality KW - building information modeling KW - industry trend KW - virtual environment ER - TY - JOUR TI - Slope Stability Analysis Using Genetic Simulated Annealing Algorithm in Conjunction with Finite Element Method AU - Cen, Weijun AU - Luo, Jiarui AU - Yu, Jishun AU - Shamin Rahman, M. T2 - KSCE JOURNAL OF CIVIL ENGINEERING DA - 2020/1// PY - 2020/1// DO - 10.1007/s12205-020-2051-5 VL - 24 IS - 1 SP - 30-37 SN - 1976-3808 KW - Slope stability KW - Genetic simulated annealing algorithm KW - Finite element method KW - Factor of safety KW - Slip surface ER - TY - JOUR TI - Degradation Model for the Tensile Strength of PVC and Rubber Gasket Materials Exposed to Benzene and PCE-Saturated Aqueous Solutions AU - Hosseini, Payam AU - Alhomair, Sultan AU - Faeli, Zahra AU - Pour-Ghaz, Mohammad AU - Gabr, Mohammed AU - Knappe, Detlef AU - Parker, Cyrus T2 - TRANSPORTATION RESEARCH RECORD AB - In this paper, a tensile strength degradation model is developed for polyvinyl chloride (PVC) pipe and three rubber gasket materials commonly used in stormwater drains and wet utilities; the degradation model considers exposure to a single contaminant at its saturation level. The contaminant considered included benzene and tetrachloroethylene (PCE) because of their prevalence. The materials considered are unplasticized Polyvinyl chloride (u-PVC) utilized as the pipe material, and three types of rubber gaskets: Polychloroprene (Neoprene-CR), Acrylonitrile (nitrile) butadiene rubber (Buna-N), and fluoroelastomer rubber (FKM—Grade A Viton TM ). First, the degradation rates of these materials are experimentally quantified using accelerated testing; then using the experimental results and Williams–Landel–Ferry (WLF) method a degradation model is developed. Finally, a simplified method is introduced to relate the tensile strength degradation of PVC to the penetration rate of the contaminants. DA - 2020/2// PY - 2020/2// DO - 10.1177/0361198120906126 VL - 2674 IS - 2 SP - 274-283 SN - 2169-4052 ER - TY - JOUR TI - Smart meters data for modeling and forecasting water demand at the user-level AU - Pesantez, J.E. AU - Berglund, E.Z. AU - Kaza, N. T2 - Environmental Modelling and Software AB - Smart meters installed at the user-level provide a new data source for managing water infrastructure. This research explores the use of machine learning methods, including Random Forests (RFs), Artificial Neural Networks (ANNs), and Support Vector Regression (SVR) to forecast hourly water demand at 90 accounts using smart-metered data. Demands are predicted using lagged demand, seasonality, weather, and household characteristics. Time-series clustering is applied to delineate data based on the time of day and day of the week, which improves model performance. Two modeling approaches are compared. Individual models are developed separately for each meter, and a Group model is trained using a data set of multiple meters. Individual models predict demands at meters in the original data set with lower error than Group models, while the Group model predicts demands at new meters with lower error than Individual models. Results demonstrate that RF and ANN perform better than SVR across all scenarios. DA - 2020/// PY - 2020/// DO - 10.1016/j.envsoft.2020.104633 VL - 125 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85078400063&partnerID=MN8TOARS KW - Smart water meters KW - AMI KW - Forecasting model KW - Hourly water demand KW - User-level data KW - Water demand management KW - Machine learning KW - Urban water systems ER - TY - JOUR TI - Demand-side Management of Peak Water Demands using Advanced Metering Infrastructure and Persuasive Games AU - Pesantez, Jorge AU - Berglund, Emily Zechman AB - &lt;p&gt;Residential water demands vary with a diurnal pattern, and peak hour demands lead to inefficiencies in the operation and management of urban water distribution systems. Peak demands generate immediate costs due to the energy requirements of pumping large volumes of water. If peak demands are not mitigated, large investments in infrastructure expansion are needed to support urban growth and economic development. Through data collection and communication approaches available through advanced metering infrastructure (AMI), demand-side management approaches could reduce peak demands. AMI data can be disaggregated to identify end uses that contribute to peak demands, and feedback about hourly use can be used to encourage demand shifting behaviors. Demand-side management implements technical approaches, such as retrofitting households with smart and water-efficient devices, and social approaches, such as dynamic water pricing, mandatory restrictions, and persuasive games that encourage voluntary participation. A community of households that shift demands can distribute the volume of water provision evenly over the hours of a day and reduce peak demands. While demand-side management strategies can reduce energy requirements associated with water supply and the need for new infrastructure development, demand management relies on the behaviors and decision-making of individuals, creating uncertainty in the emergent cost savings and infrastructure impacts. This research develops an agent-based modeling methodology to simulate the performance of demand-management approaches to reduce peak water demands. A persuasive game is simulated that implements a leaderboard to encourage cooperation and competition within and among neighborhoods of water users. Household agents receive points for shifting end-uses, based on the difficulty and water savings associated with end-user behaviors. Opinion dynamics simulate agents&amp;#8217; information exchange using a leaderboard, which provides motivation for agents to increase individual and team scores. The methodology is applied for AMI data to test the effects of persuasive games on reducing peak demands.&lt;/p&gt; DA - 2020/3/23/ PY - 2020/3/23/ DO - 10.5194/egusphere-egu2020-5876 VL - 3 UR - https://doi.org/10.5194/egusphere-egu2020-5876 ER - TY - JOUR TI - Assessing within-lake nutrient cycling through multi-decadal Bayesian mechanistic modeling AU - Obenour, Daniel AU - Giudice, Dario Del AU - Aupperle, Matthew AU - Sankarasubramanian, Arumugam AB - &lt;p&gt;Nutrient recycling from bottom sediments can provide substantial internal loading to eutrophic lakes and reservoirs, potentially exceeding external watershed loads. However, measurements of sediment nutrient fluxes are rare for most waterbodies in the United States, causing many modeling studies to parameterize these fluxes in simplistic ways or else make assumptions about complex sediment diagenetic rates. Here we propose an alternative approach to understanding internal cycling, using a mass-balance model combined with Bayesian inference to rigorously update prior information on nutrient flux parameters. The approach is applied to Jordan Lake, a major water supply reservoir in North Carolina (USA) that has been highly eutrophic since impoundment in the early 1980s, with chlorophyll a concentrations occasionally exceeding 100 &amp;#181;g/L. We simulate monthly nitrogen and phosphorus dynamics in the water column and sediment layer of four longitudinal reservoir segments, forced by watershed flows, nutrient loads, and meteorology. The model is calibrated within the Bayesian framework and validated using a multi-decadal record of surface nutrient concentration data. We compare multiple versions of the model to assess the importance of prior knowledge from previous literature, the multi-decadal calibration period, and the mechanistic formulation for obtaining accurate and robust predictive performance. Overall, the model explains from 40-60% of the variability in observed nutrient concentrations. Model results indicate that a large fraction (&gt;40%) of phosphorus is lost in the upstream reaches of the reservoir, likely due to rapid settling and burial of particulate material. Within the main body of the reservoir, phosphorus recycling rates were found to be higher than expected a priori, particularly in the summer season. Results show how nutrients stored in lacustrine sediment have been an important source of internal loading to the reservoir for multiple decades, and will dampen the effects of external watershed loading reductions, at least in the near term. To better understand potential time scales for reservoir recovery, we perform future simulations over a multi-decadal period and characterize forecast uncertainties.&lt;/p&gt; DA - 2020/3/23/ PY - 2020/3/23/ DO - 10.5194/egusphere-egu2020-4232 UR - https://doi.org/10.5194/egusphere-egu2020-4232 ER - TY - JOUR TI - Variability in Measured Real-World Operational Energy Use and Emission Rates of a Plug-In Hybrid Electric Vehicle AU - Frey, H. Christopher AU - Zheng, Xiaohui AU - Hu, Jiangchuan T2 - Energies AB - Compared to comparably sized conventional light duty gasoline vehicles (CLDGVs), plug-in hybrid electric vehicles (PHEVs) may offer benefits of improved energy economy, reduced emissions, and the flexibility to use electricity as an energy source. PHEVs operate in either charge depleting (CD) or charge sustaining (CS) mode; the engine has the ability to turn on and off; and the engine can have multiple cold starts. A method is demonstrated for quantifying the real-world activity, energy use, and emissions of PHEVs, taking into account these operational characteristics and differences in electricity generation resource mix. A 2013 Toyota Prius plug-in was measured using a portable emission measurement system. Vehicle specific power (VSP) based modal average energy use and emission rates are inferred to assess trends in energy use and emissions with respect to engine load and for comparisons of engine on versus engine off, and cold start versus hot stabilized running. The results show that, compared to CLDGVs, the PHEV operating in CD mode has improved energy efficiency and lower CO2, CO, HC, NOx, and PM2.5 emission rates for a wide range of power generation fuel mixes. However, PHEV energy use and emission rates are highly variable, with periods of relatively high on-road emission rates related to cold starts. DA - 2020/3/4/ PY - 2020/3/4/ DO - 10.3390/en13051140 VL - 13 IS - 5 UR - https://doi.org/10.3390/en13051140 KW - light duty gasoline vehicle KW - portable emission measurement system KW - carbon dioxide emissions KW - carbon monoxide emissions KW - nitrogen oxides emissions KW - hydrocarbon emissions KW - cold start ER - TY - JOUR TI - Elevated levels of per- and polyfluoroalkyl substances in Cape Fear River Striped Bass (Morone saxatilis) are associated with biomarkers of altered immune and liver function AU - Guillette, T. C. AU - McCord, James AU - Guillette, Matthew AU - Polera, M. E. AU - Rachels, Kyle T. AU - Morgeson, Clint AU - Kotlarz, Nadine AU - Knappe, Detlef R. U. AU - Reading, Benjamin J. AU - Strynar, Mark AU - Belcher, Scott M. T2 - ENVIRONMENT INTERNATIONAL AB - Per- and polyfluoroalkyl substances (PFAS) are anthropogenic chemicals of concern that persist in the environment. Environmental monitoring revealed high concentrations of hexafluoropropylene oxide dimer acid (HFPO-DA) and other novel PFAS in the lower Cape Fear River; however, there is limited information on PFAS exposures and effects of this contamination on aquatic biota. Serum concentrations of 23 PFAS in Striped Bass (Morone saxatilis) from the Cape Fear River (n = 58) and a reference population from an aquaculture laboratory on the Pamlico/Tar watershed (n = 29) were quantified using liquid chromatography and high-resolution mass spectrometry, and correlations between PFAS concentrations and health-related serum biomarkers were evaluated. Perfluorooctane sulfonate, the predominant PFAS in Cape Fear River Striped Bass serum, was detectable in every sample with serum concentrations reaching 977 ng/mL. Perfluorononanoic and perfluorodecanoic acid were also detected in all samples, with perfluorohexanesulfonic acid present in >98% of the samples. HFPO-DA (range <0.24-5.85 ng/mL) and Nafion byproduct 2 (range <0.2-1.03 ng/mL) were detected in 48% and 78% of samples, respectively. The mean total PFAS concentration found in domestic Striped Bass raised in well-water under controlled aquaculture conditions was 40 times lower, with HPFO-DA detected in 10% of the samples, and Nafion byproduct 2 was not detected. The elevated PFAS concentrations found in the Cape Fear River Striped Bass were associated with biomarkers of alterations in the liver and immune system. DA - 2020/3// PY - 2020/3// DO - 10.1016/j.envint.2019.105358 VL - 136 SP - SN - 1873-6750 ER - TY - JOUR TI - A unified constitutive model in simulating creep strains in addition to fatigue responses of Haynes 230 AU - Barrett, Paul R. AU - Hassan, Tasnim T2 - INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES AB - • Evaluation of modeling features in simulating creep and fatigue responses. • Need of coupling continuum damage model to unified constitutive model (UCM). • Issues in simulating creep strains at low temperatures by the modified UCM. • Issues in simulating fatigue responses at high temperatures by the modified UCM. • Challenges of UCM in simulating elevated temperature creep and fatigue responses. A unified constitutive model (UCM) specifies that its flow rule for inelasticity computes both the plastic and creep strains as a single state variable. A Chaboche framework based UCM with the modeling features of strain range-dependence, strain rate-dependence, static recovery and mean stress evolution was developed and experimentally validated against a broad set of fatigue and fatigue-creep responses of Haynes 230 (HA 230) under isothermal and anisothermal temperature conditions. This article demonstrates that this advanced Chaboche-based UCM can simulate the secondary minimum creep strain rates reasonably, but is unable to predict the tertiary creep strain responses. To simulate the tertiary creep strain responses a continuum damage model is needed to be coupled to the UCM. This study also evaluated three different unified flow rules, Norton's power law, exponential Norton and sine-hyperbolic Norton for calculating the inelastic strain rates. It is found that the choice of flow rule is important in simulating the stress amplitude saturation rate of fatigue responses, but has minimal effect in simulating the tertiary creep strains. However, the damage coupled UCM independent to the unified flow rules listed above can adequately simulate fatigue, fatigue-creep including the stress relaxation during strain dwell, and creep strain up to the tertiary range for HA 230. The drawbacks of the damage coupled UCM are the hysteresis loop softening at very high temperatures and asymptotic simulation at low creep temperatures, which are identified as challenges to be overcome towards developing a universal UCM for robust design and analysis of high temperature components. DA - 2020/3/1/ PY - 2020/3/1/ DO - 10.1016/j.ijsolstr.2019.09.001 VL - 185 SP - 394-409 SN - 1879-2146 KW - Viscoplasticity KW - Unified constitutive model KW - Damage model KW - Creep KW - Fatigue-creep ER - TY - JOUR TI - Reducing error in water distribution network simulations with field measurements AU - Ricca, Henry AU - Patskoski, Jason AU - Mahinthakumar, Gnanamanikam T2 - JOURNAL OF APPLIED WATER ENGINEERING AND RESEARCH AB - Reduction of error in water distribution network (WDN) models leads to simulations that are more representative of actual network conditions and allows for more realistic system responses. Technological improvements have resulted in data collection becoming more prevalent in WDNs. This study quantifies the reduction in model error when considering demand uncertainty by incorporating pressure reducing valve (PRV) monitoring, operational monitoring, and supervisory control and data acquisition (SCADA) system data. Model implementation procedures were developed for each of these data types. For this study, outputs obtained by the modeling software EPANET for a WDN model built with hourly measured demands were treated as actual network observations. Pressures simulated by the network model that incorporated all three types of data had less error than pressures simulated by a base model representative of what water managers would use without access to this data. Model improvement varies both spatially and temporally. DA - 2020/1/2/ PY - 2020/1/2/ DO - 10.1080/23249676.2020.1719218 VL - 8 IS - 1 SP - 15-27 SN - 2324-9676 KW - Boundary condition KW - data collection KW - uncertainty reduction KW - water distribution modeling ER - TY - JOUR TI - Developing construction hazard recognition skill: leveraging safety climate and social network safety communication patterns AU - Pandit, Bhavana AU - Albert, Alex AU - Patil, Yashwardhan T2 - CONSTRUCTION MANAGEMENT AND ECONOMICS AB - Poor hazard recognition skill is a widespread issue in the construction industry. Therefore, an understanding of factors that influence the development of hazard recognition skill among workers is fundamental to effective safety management. Based on social learning theory which suggests that individuals learn efficiently by observing, interacting, and emulating others in workplaces, the current article reports findings from a larger study that examined the effect of safety climate and social-network safety communication patterns on the hazard recognition skill demonstrated by workers. More specifically, building upon previously reported findings presented in Pandit et al. which suggests that maintaining a more positive safety climate can lead to superior hazard recognition levels, the current article presents additional results examining the effect of safety climate and social-network safety communication patterns—maintained by workers—on the demonstrated hazard recognition skill. The study involved recruiting construction crews from 57 projects in the United States where safety climate and social-network safety communication data were gathered using questionnaire surveys—which was then followed by a hazard recognition activity. The results suggest that, apart from the safety climate, social-network safety communication patterns are positively related to the demonstrated hazard recognition skill. In addition, evidence of an interaction effect was found—suggesting that establishing a positive safety climate and maintaining higher levels of safety communication can yield synergistic benefits. DA - 2020/7/2/ PY - 2020/7/2/ DO - 10.1080/01446193.2020.1722316 VL - 38 IS - 7 SP - 640-658 SN - 1466-433X KW - Safety management KW - construction safety KW - occupational safety KW - safety culture KW - safety climate KW - safety communication KW - social networks ER - TY - JOUR TI - Open Source Energy System Modeling Using Break-Even Costs to Inform State-Level Policy: A North Carolina Case Study AU - Li, Binghui AU - Thomas, Jeffrey AU - Queiroz, Anderson Rodrigo AU - DeCarolis, Joseph F. T2 - ENVIRONMENTAL SCIENCE & TECHNOLOGY AB - Rigorous model-based analysis can help inform state-level energy and climate policy. In this study, we utilize an open-source energy system optimization model and publicly available data sets to examine future electricity generation, CO2 emissions, and CO2 abatement costs for the North Carolina electric power sector through 2050. Model scenarios include uncertainty in future fuel prices, a hypothetical CO2 cap, and an extended renewable portfolio standard. Across the modeled scenarios, solar photovoltaics represent the most cost-effective low-carbon technology, while trade-offs among carbon constrained scenarios largely involve natural gas and renewables. We also develop a new method to calculate break-even costs, which indicate the capital costs at which specific technologies become cost-effective within the model. Significant variation in break-even costs are observed across different technologies and scenarios. We illustrate how break-even costs can be used to inform the development of an extended renewable portfolio standard in North Carolina. Utilizing the break-even costs to calibrate a tax credit for onshore wind, we find that the resultant wind deployment displaces other renewables, and thus has a negligible effect on CO2 emissions. Such insights can provide crucial guidance to policymakers weighing different policy options. This study provides an analytical framework to conduct similar analyses in other states using an open source model and freely available data sets. DA - 2020/1/21/ PY - 2020/1/21/ DO - 10.1021/acs.est.9b04184 VL - 54 IS - 2 SP - 665-676 SN - 1520-5851 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85078394675&partnerID=MN8TOARS ER - TY - JOUR TI - Critical Role of Polymer Aggregation and Miscibility in Nonfullerene-Based Organic Photovoltaics AU - Yi, Xueping AU - Peng, Zhengxing AU - Xu, Bing AU - Seyitliyev, Dovletgeldi AU - Ho, Carr Hoi Yi AU - Danilov, Evgeny O. AU - Kim, Taesoo AU - Reynolds, John R. AU - Amassian, Aram AU - Gundogdu, Kenan AU - Ade, Harald AU - So, Franky T2 - ADVANCED ENERGY MATERIALS AB - Abstract Understanding the correlation between polymer aggregation, miscibility, and device performance is important to establish a set of chemistry design rules for donor polymers with nonfullerene acceptors (NFAs). Employing a donor polymer with strong temperature‐dependent aggregation, namely PffBT4T‐2OD [poly[(5,6‐difluoro‐2,1,3‐benzothiadiazol‐4,7‐diyl)‐ alt ‐(3,3″′‐di(2‐octyldodecyl)‐2,2′;5′,2″;5″,2″′‐quaterthiophen‐5,5‐diyl)], also known as PCE‐11 as a base polymer, five copolymer derivatives having a different thiophene linker composition are blended with the common NFA O‐IDTBR to investigate their photovoltaic performance. While the donor polymers have similar optoelectronic properties, it is found that the device power conversion efficiency changes drastically from 1.8% to 8.7% as a function of thiophene content in the donor polymer. Results of structural characterization show that polymer aggregation and miscibility with O‐IDTBR are a strong function of the chemical composition, leading to different donor–acceptor blend morphology. Polymers having a strong tendency to aggregate are found to undergo fast aggregation prior to liquid–liquid phase separation and have a higher miscibility with NFA. These properties result in smaller mixed donor–acceptor domains, stronger PL quenching, and more efficient exciton dissociation in the resulting cells. This work indicates the importance of both polymer aggregation and donor–acceptor interaction on the formation of bulk heterojunctions in polymer:NFA blends. DA - 2020/2// PY - 2020/2// DO - 10.1002/aenm.201902430 VL - 10 IS - 8 SP - SN - 1614-6840 KW - charge generation KW - charge transport KW - morphology KW - nonfullerene acceptors KW - polymer aggregation ER - TY - CHAP TI - Climate Model Response Uncertainty in Projections of Climate Change Impacts on Air Quality T2 - Springer Proceedings in Complexity AB - Uncertainties in climate simulations can strongly propagate to estimates of climate change impacts, including its effects on air pollution. Here we use a coupled modeling framework to evaluate the role of climate model response in projections of climate-induced impacts on air quality. Within integrated economic, climate, and air pollution projections, climate model response is altered by modifying the climate sensitivity of the framework’s Earth system component. We find that variations in climate sensitivity ranging from 2.0 to 4.5 °C per doubling of CO2 can change projections of the climate penalty on O3 and PM2.5 pollution in the U.S. by more than 2 ppb and 0.5 µg m−3. The impact of uncertainty due to climate model response can be as important as that related to greenhouse gas emissions scenario or natural variability. PY - 2020/// DO - 10.1007/978-3-030-22055-6_69 UR - http://dx.doi.org/10.1007/978-3-030-22055-6_69 ER - TY - JOUR TI - Analysis of travel characteristics and access mode choice of elderly urban rail riders in Denver, Colorado AU - Liu, C. AU - Bardaka, E. AU - Palakurthy, R. AU - Tung, L.-W. T2 - Travel Behaviour and Society AB - With the proportion of the elderly increasing worldwide, significant research efforts have been devoted to understanding the travel characteristics of the ageing population. Our research contributes to a limited number of studies that have investigated how the elderly (65+) access urban rail in comparison to younger adults (19–64). Using descriptive and econometric analyses of on-board survey data from Denver, Colorado, we respond to the following two research questions: (1) How do trip characteristics, including access and egress mode, trip purpose, choice of station, and travel time of elderly urban rail riders differ from those of their younger counterparts? (2) Do the determinants of access mode choice, such as built environment and individual characteristics, impact differently the choices of elderly and younger adult riders? Our results indicate that the elderly urban rail users differ from the average elderly population in the US in terms of their employment status (46% of the elderly Denver rail riders are employed). Consequently, dissimilarities in travel behavior between elderly and younger adult riders are on average lower than expected, although important differences are still observed. Results from a multinomial probit model on access mode choice for trips between home and a rail station show that younger adults and employed elderly travelers place higher importance on travel time when choosing a mode to access a station compared to non-employed elderly travelers. On the other hand, the built environment and vehicle ownership have a significantly higher influence on access mode choice for elderly compared to younger adult travelers. DA - 2020/// PY - 2020/// DO - 10.1016/j.tbs.2019.11.004 VL - 19 SP - 194-206 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85078658149&partnerID=MN8TOARS ER - TY - JOUR TI - Investigation of seismic rehabilitation of steel buildings with semi-rigid connections AU - Kazem, Hamid AU - Kazem, Hossein AU - Ghahremannejad, Masoud AU - Vosoughi, Payam AU - Hosseini, Farshid AU - Ghafory-Ashtiany, Mohsen T2 - PROCEEDINGS OF THE INSTITUTION OF CIVIL ENGINEERS-STRUCTURES AND BUILDINGS AB - The Khorjinee connection is a special connection that was widely used in the construction of low-rise steel structures in Iran before the national seismic code was established. However, catastrophic experiences from recent earthquakes have shown that these connections are highly vulnerable to seismic loads. In fact, it is recognised that such connections should be classified as non-seismic, semi-rigid connections with unknown rotational stiffness. As a result of this issue, many structures with these connections may need to be rehabilitated to ensure their safety in future earthquakes. In this study the dynamic properties of a half-scale model of a four-storey steel structure with Khorjinee connections were determined by a forced vibration test. The structure was then separately rehabilitated by means of four different bracing configurations (X bracing, chevron bracing, eccentrically braced frames (EBFs) and knee braces) and the structural responses were investigated. The results, which include the natural frequencies, mode shapes and damping ratios for each case, present a realistic approach to enable engineers to select the best way of strengthening steel structures with Khorjinee connections according to diverse structural limitations. The structural displacement ratios were found to be significantly larger in structures with EBFs and knee bracing systems when the number of braced spans is high compared with the first mode. DA - 2020/2// PY - 2020/2// DO - 10.1680/jstbu.17.00192 VL - 173 IS - 2 SP - 99-108 SN - 1751-7702 KW - buildings, structures & design KW - rehabilitation, reclamation & renovation KW - seismic engineering ER - TY - JOUR TI - Correcting Power Leakage Equation for Improved Leakage Modeling and Detection AU - Kabaasha, A. M. AU - Zyl, J. E. AU - Mahinthakumar, G. ''Kumar'' T2 - JOURNAL OF WATER RESOURCES PLANNING AND MANAGEMENT AB - Fluid pressure influences leakage flow rate in water distribution pipe networks. Significant progress has been made in the use of pressure management techniques to control leakage. An empirical power equation (known as the N1 power equation) is widely used to model the pressure–leakage relationship in practice. However, recent research has shown that this equation is not able to accurately model leakage under various conditions. When estimating the N1 leakage exponent for a system, the power equation assumes that leakage is located at a point in the network that is representative of the average system pressure, which is rarely true. In addition, parameters of the power equation are not constant but vary with pressure, which is a problem especially for water distribution pipe networks where pressure varies with time, for example, due to diurnal demand variation. These factors result in significant errors when the power equation is used to model leakage in real water distribution networks. This technical note analyzes the factors that introduce errors in the power equation and proposes methods to improve its accuracy. The performance of the methods is demonstrated using a case study. DA - 2020/3/1/ PY - 2020/3/1/ DO - 10.1061/(ASCE)WR.1943-5452.0001172 VL - 146 IS - 3 SP - SN - 1943-5452 KW - Leakage modeling KW - Leakage detection KW - Leakage power equation KW - Modified orifice equation KW - Water distribution system ER - TY - JOUR TI - Modeling Framework for Capacity Analysis of Freeway Segments: Application to Ramp Weaves AU - Xu, Dezhong AU - Rouphail, Nagui M. AU - Aghdashi, Behzad AU - Ahmed, Ishtiak AU - Elefteriadou, Lily T2 - TRANSPORTATION RESEARCH RECORD AB - This research proposes a new modeling framework for the analysis of freeway segments. The framework provides a continuum from the operation of ramp weave segments to an equivalent basic segment serving the same traffic with the same number of lanes and free-flow speed. This approach distinguishes between congestion effects caused by high v/c ratios from turbulence caused by merging, diverging, and weaving traffic, thus greatly simplifying the model form, and its extensibility to other freeway segment types. The paper presents an application of this new framework to the analysis of ramp weaves, which were not sufficiently sampled in the development of the HCM6 methodology. The proposed model is shown to be superior to the HCM6 method both in relation to explaining field observations of speeds and in its simplicity in application. The results include a new formula for capacity estimation that is highly sensitive to segment length, and a speed estimation model that converges for low weaving volumes or at very high weaving segment lengths to that observed at a basic segment. Because the proposed model is calibrated with data mostly from North Carolina, it is recommended that data at additional sites be included in a larger calibration effort to ensure its applicability to a broader set of weaving segment configurations. DA - 2020/1// PY - 2020/1// DO - 10.1177/0361198119900157 VL - 2674 IS - 1 SP - 148-159 SN - 2169-4052 ER - TY - JOUR TI - Seismic Performance of Circular Concrete Columns Reinforced with High-Strength Steel AU - Barcley, L.B. AU - Kowalsky, M.J. T2 - Journal of Structural Engineering AB - In modern seismic design of reinforced concrete structures, areas designed to form plastic hinges are reinforced with ASTM A706 steel because of its ability to sustain large elongations, as well as its tightly controlled specifications on yield and ultimate strength. The A706 standard now includes reinforcing steel with a nominal yield strength of 550 MPa (80 ksi), but its use in seismic applications is limited given the lack of experimental data on its behavior in members forming plastic hinges. In this paper, the results of four circular Grade 80 (550) reinforced columns tested under reverse cyclic loading are discussed and compared with companion Grade 60 (420) reinforced columns. The results showed that columns reinforced with Grade 80 (550) steel exhibited rebar fracture at lower levels of column deformation, although the onset of bar buckling, plastic hinge lengths, and energy dissipation were similar to columns reinforced with Grade 60 (420) steel. DA - 2020/2// PY - 2020/2// DO - 10.1061/(ASCE)ST.1943-541X.0002452 VL - 146 IS - 2 SP - 04019198 SN - 1943-541X KW - Reinforced concrete KW - High-strength steel KW - Seismic design KW - Performance-based design KW - Critical bending strain ER - TY - JOUR TI - Improving Safety, Efficiency, and Productivity: Evaluation of Fall Protection Systems for Bridge Work Using Wearable Technology and Utility Analysis AU - Zuluaga, Carlos M. AU - Albert, Alex AU - Winkel, Munir A. T2 - JOURNAL OF CONSTRUCTION ENGINEERING AND MANAGEMENT AB - The construction industry is experiencing a number of challenges. For example, construction workplaces report poor safety performance, widespread inefficiencies, and stagnant productivity rates. These challenges often translate into higher-order issues including cost overruns, schedule growths, and project failure. Accordingly, much of construction research has focused on identifying best practices to improve safety, efficiency, and productivity. However, the majority of these efforts focus on resolving one of these challenges (e.g., safety) rather than holistically addressing safety, efficiency, and productivity in unison. Unfortunately, such an approach can yield unintended consequences in certain circumstances. For example, a narrow focus on productivity may adversely affect safety performance, and vice versa. One nationwide safety issue that has received much recent attention is the protection of highway and bridge workers from falls to lower levels when working on bridge decks. In these circumstances, highway and bridge workers largely rely on existing bridge guardrails for their protection against falls. However, most bridge guardrails do not offer a barrier height of 107±8 cm (42±3 in.) for sufficient protection as per regulatory requirements. To protect these workers, a few transportation agencies are beginning to adopt passive fall protection systems that can be attached to the guardrails to temporarily increase the barrier height. The purpose of the current research was to support these efforts by evaluating four fall protection systems that are actively being considered for adoption based on the expected safety, efficiency, and productivity benefits they offer. The study objectives were accomplished through 96 field trials where physiological responses, postural demands, activity rates, and the associated utility were gathered from participating workers using wearable technology and a questionnaire survey. The research effort identified fall protection systems that offer the most advantages in terms of safety, efficiency, and productivity. The adoption of the recommended systems can yield substantial benefits in terms of safety, efficiency, and productivity, apart from reducing the risk of falls. DA - 2020/2/1/ PY - 2020/2/1/ DO - 10.1061/(ASCE)CO.1943-7862.0001764 VL - 146 IS - 2 SP - SN - 1943-7862 KW - Fall protection KW - Construction safety KW - Wearable technology KW - Productivity KW - Efficiency ER - TY - JOUR TI - Simulation-Based Analysis of Sign Blanket Replacement Strategies AU - Rasdorf, William AU - Machado, Patricia T2 - TRANSPORTATION RESEARCH RECORD AB - Transportation agencies are responsible for maintaining traffic signs, a critical part of any transportation network, in a satisfactory condition. This is achieved by the implementation of sign maintenance and replacement strategies. This paper presents the results of a sign replacement simulation model based on the Blanket Replacement method. Although the case study described here was based on North Carolina (NC) sign data, its results provide insights for all transportation agencies about effective practices that result in cost-efficient sign replacement strategies. The authors found that daytime inspections reduce the number of unsatisfactory signs while having little effect on cost. Grace periods were found to be efficient in reducing costs. Longer replacement cycles (e.g., 20 years) that consider daytime inspections and a grace period resulted in more cost-efficient strategies than those with shorter replacement cycles (e.g., 10 years). DA - 2020/1// PY - 2020/1// DO - 10.1177/0361198119898110 VL - 2674 IS - 1 SP - 57-67 SN - 2169-4052 ER - TY - JOUR TI - Review of wearable thermoelectric energy harvesting: From body temperature to electronic systems AU - Nozariasbmarz, Amin AU - Collins, Henry AU - Dsouza, Kelvin AU - Polash, Mobarak Hossain AU - Hosseini, Mahshid AU - Hyland, Melissa AU - Liu, Jie AU - Malhotra, Abhishek AU - Ortiz, Francisco Matos AU - Mohaddes, Farzad AU - Ramesh, Viswanath Padmanabhan AU - Sargolzaeiaval, Yasaman AU - Snouwaert, Nicholas AU - Ozturk, Mehmet C. AU - Vashaee, Daryoosh T2 - APPLIED ENERGY AB - Global demand for battery-free metrics and health monitoring devices has urged leading research agencies and their subordinate centers to set human energy harvesting and self-powered wearable technologies as one of their primary research objectives. After an overview of wearables market trends, different active and passive methods of body energy harvesting for powering low-consumption electronic devices are introduced, and challenges of device fabrication are discussed. The discussion continues with the primary emphasis on thermoelectric generators for body heat harvesting. The physiological aspects of the human body involved in heat generation are elaborated. System requirements and the influence of different parameters on the performance of thermoelectric generators are studied at the material, device, and system levels. Finally, the advancements in the development of rigid and flexible thermoelectric generators for wearable and textile integration are presented. DA - 2020/1/15/ PY - 2020/1/15/ DO - 10.1016/j.apenergy.2019.114069 VL - 258 SP - SN - 1872-9118 KW - Self-powered devices KW - Body heat harvesting KW - Wearable technology KW - Thermoelectric generators KW - Flexible harvester ER - TY - JOUR TI - Risk informed validation framework for external flooding scenario AU - Bodda, Saran Srikanth AU - Gupta, Abhinav AU - Dinh, Nam T2 - NUCLEAR ENGINEERING AND DESIGN AB - Safety of nuclear plants against external flooding has gained significant attention following the accident at Fukushima Daiichi nuclear power station. In United States, Oyster Creek nuclear plant was safely shutdown when high storm surge during hurricane Sandy caused a potential flooding threat. Subsequently, the nuclear energy industry experienced a significant activity in Probabilistic Risk Assessment (PRA) for external flooding. Increasingly, methods of computational fluid dynamics including advanced simulation codes are being considered to evaluate the sequence of events during different scenarios of flooding at a plant. One of the key limitations in the use of advanced codes for external flooding is related to a lack of credibility of such simulations. The motivation of this study is to develop a formal validation approach that provides a basis to quantify credibility of risk assessments that are based on advanced simulation codes. In this study, we illustrate the application of existing performance based risk-informed validation framework to an external flooding event. However, it is determined that a direct application of this approach to flooding is restricted due to a lack of relevant data to evaluate experimental fragilities for flooding failures. Therefore, we take a simple synthetic example to evaluate the applicability of the proposed framework to validation of flooding PRA scenario and update the proposed framework as needed. DA - 2020/1// PY - 2020/1// DO - 10.1016/j.nucengdes.2019.110377 VL - 356 SP - SN - 1872-759X KW - Risk-informed validation KW - External flooding KW - PRA KW - Bayesian inference KW - Uncertainty quantification ER - TY - JOUR TI - Assessment of alternative herbicides for residential sewer root treatment and their effects on downstream treatment plant nitrification AU - Eslamiamirabadi, M. AU - Burton, J.D. AU - de los Reyes, F.L., III AU - Ducoste, J.J. T2 - Journal of Environmental Management AB - The conveyance of wastewater in sewer pipes can be severely limited by the growth of plant roots, which can be controlled with herbicides. However, adding herbicides in sewer lines may affect downstream biological wastewater treatment processes. The effects of three herbicides (Dithiopyr, Penoxsulam, and Triclopyr) on the mortality of cottonwood tree roots and on downstream biological nitrification were determined. The results showed that Triclopyr achieved the highest root mortality (96%) followed by Penoxsulam (77%) and Dithiopyr (75%). At concentrations used at the point of application in sewer pipes, all herbicides caused nitrification inhibition and reduction in organic carbon removal in activated sludge. However, no inhibition was observed at the more diluted concentrations approximately equal to levels that may reach the wastewater treatment facility. Overall, Triclopyr appears to be the best performing herbicide with the highest root kill. DA - 2020/3// PY - 2020/3// DO - 10.1016/j.jenvman.2019.110058 VL - 258 SP - 110058 J2 - Journal of Environmental Management LA - en OP - SN - 0301-4797 UR - http://dx.doi.org/10.1016/j.jenvman.2019.110058 DB - Crossref ER - TY - JOUR TI - Response of High-Density Polyethylene Geomembrane-Sand Interfaces under Cyclic Shear Loading: Laboratory Investigation AU - Cen, W. J. AU - Wang, H. AU - Yu, L. AU - Rahman, M. S. T2 - INTERNATIONAL JOURNAL OF GEOMECHANICS AB - Geomembranes are thin polymeric sheets used as barriers to liquid or gas intrusion in earth structures due to their low permeability. The mechanical behavior of geomembrane-soil interfaces plays an important role in the stability analysis of geomembrane structures under cyclic loading caused by an earthquake or traffic. In this study, a series of cyclic shear tests were conducted using a large-scale direct shear apparatus to observe the cyclic shear response of geomembrane-sand interfaces, with emphasis on vertical displacement and cyclic shear stiffness. The influences of vertical pressure, geomembrane texture, and cyclic shear loading form on the cyclic shear behavior of geomembrane-sand interfaces were examined. The cyclic shear stiffness showed an increasing trend with increasing vertical pressure, but significantly decreased with increasing shear-displacement amplitude. Textured geomembranes can effectively improve the cyclic shear strength of geomembrane-sand interfaces. The volumetric behavior of geomembrane-sand interfaces is evidently dependent on the form of cyclic shear loading and the magnitude of applied vertical pressure. The cyclic shear behavior of pure sand was also compared with that of geomembrane-sand interfaces. DA - 2020/2/1/ PY - 2020/2/1/ DO - 10.1061/(ASCE)GM.1943-5622.0001540 VL - 20 IS - 2 SP - SN - 1943-5622 KW - Geomembrane-sand interface KW - Cyclic shear test KW - Volumetric behavior KW - Cyclic shear stiffness ER - TY - JOUR TI - Assessing Vertical Diffusion and Cyanobacteria Bloom Potential in a Shallow Eutrophic Reservoir AU - Han, Yue AU - Smithheart, Jeremy W. AU - Smyth, Robyn L. AU - Aziz, Tarek N. AU - Obenour, Daniel R. T2 - LAKE AND RESERVOIR MANAGEMENT AB - Han Y, Smithheart JW, Smyth RL, Aziz TN, Obenour CR. 2019. Assessing vertical diffusion and cyanobacteria bloom potential in a shallow eutrophic reservoir. Lake Reserv Manage. 36:169–185.Harmful blooms of cyanobacteria are an increasing threat to many lakes and reservoirs. While vertical mixing has been shown to be an important control on cyanobacteria dominance in some lakes, the relevance of mixing in relatively shallow turbid systems remains unclear. To explore mixing and its impact on cyanobacteria bloom potential, we leveraged data from a multiyear field campaign of a central North Carolina reservoir where artificial circulators were installed to (1) implement a parsimonious one-dimensional (1D) turbulent diffusion model with an artificial circulation term, (2) introduce a novel multi-objective calibration approach considering both water column temperature and stability, and (3) explore how mixing affects cyanobacteria bloom potential through changes in cyanobacteria light exposure relative to other algal taxa. Our multi-objective calibration approach is shown to realistically simulate both water temperature (R2 = 0.99) and water column stability (R2 = 0.62) throughout the year. Analysis of artificial mixing demonstrates the relative insignificance of the circulator deployment in our study area and suggests that at least eight times the implemented circulation rate would be required to substantially reduce the ability of buoyant cyanobacteria to outcompete other algal taxa for light. Overall, this study demonstrates an efficient and systematic approach for characterizing vertical mixing in lakes and reservoirs, which can be used to assess the viability of artificial circulation prior to deployment. DA - 2020/4/2/ PY - 2020/4/2/ DO - 10.1080/10402381.2019.1697402 VL - 36 IS - 2 SP - 169-185 SN - 2151-5530 UR - http://dx.doi.org/10.1080/10402381.2019.1697402 KW - Algal bloom KW - artificial mixing KW - cyanobacteria KW - diffusion KW - turbid lake ER - TY - JOUR TI - Molecular weight distribution of asphalt binders from Laser Desorption Mass Spectroscopy (LDMS) technique and its relationship to linear viscoelastic relaxation spectra AU - Gundla, Akshay AU - Underwood, B. Shane T2 - FUEL AB - Asphalt binder is a complex viscoelastic hydrocarbon, whose performance depends upon interaction between its physical and chemical properties, both of which are equally important to the successful understanding of the material. In this research effort, a physico-chemical relationship is developed by utilizing the technique of Laser Desorption Mass Spectroscopy (LDMS) to relate the molecular structure of asphalt binders to its viscoelastic properties. The molecular weight distribution (MWD) data obtained from the LDMS technique is used to develop a relationship between number average molecular weight and width of relaxation spectrum of asphalt binders obtained from linear viscoelastic characterization using dynamic shear rheometer. The relationship shows that as the molecular weight of asphalt binders increase, they require more time to relax the developed stresses. Also, the shape descriptors of the molecular weight distribution suggest that asphalt binders possessing greater asymmetry and kurtosis require more time to relax the developed stresses. DA - 2020/2/15/ PY - 2020/2/15/ DO - 10.1016/j.fuel.2019.116444 VL - 262 SP - SN - 1873-7153 KW - Asphalt binder KW - Molecular weight distribution KW - Physico-chemical relationship KW - Linear viscoelasticity KW - Relaxation spectra KW - Laser Desorption Mass Spectroscopy ER - TY - JOUR TI - Bayesian mechanistic modeling characterizes Gulf of Mexico hypoxia: 1968-2016 and future scenarios AU - Del Giudice, Dario AU - Matli, V. R. R. AU - Obenour, Daniel R. T2 - ECOLOGICAL APPLICATIONS AB - Abstract The hypoxic zone in the northern Gulf of Mexico is among the most dramatic examples of impairments to aquatic ecosystems. Despite having attracted substantial attention, management of this environmental crisis remains challenging, partially due to limited monitoring to support model development and long‐term assessments. Here, we leverage new geostatistical estimates of hypoxia derived from nearly 150 monitoring cruises and a process‐based model to improve characterization of controlling mechanisms, historic trends, and future responses of hypoxia while rigorously quantifying uncertainty in a Bayesian framework. We find that November–March nitrogen loads are important controls of sediment oxygen demand, which appears to be the major oxygen sink. In comparison, only ~23% of oxygen in the near‐bottom region appears to be consumed by net water column respiration, which is driven by spring and summer loads. Hypoxia typically exceeds 15,600 km 2 in June, peaks in July, and declines below 10,000 km 2 in September. In contrast to some previous Gulf hindcasting studies, our simulations demonstrate that hypoxia was both severe and worsening prior to 1985, and has remained relatively stable since that time. Scenario analysis shows that halving nutrient loadings will reduce hypoxia by 37% with respect to 13,900 km 2 (1985–2016 median), while a +2°C change in water temperature will cause a 26% hypoxic area increase due to enhanced sediment respiration and reduced oxygen solubility. These new results highlight the challenges of achieving hypoxia reduction targets, particularly under warming conditions, and should be considered in ecosystem management. DA - 2020/3// PY - 2020/3// DO - 10.1002/eap.2032 VL - 30 IS - 2 SP - SN - 1939-5582 KW - Bayesian inference KW - climate change KW - dead hypoxic zones KW - eutrophication KW - Gulf of Mexico KW - hindcasts and projections KW - process-based modeling KW - riverine nitrogen KW - uncertainty quantification ER - TY - JOUR TI - Simulation of containment and wireless emergency alerts within targeted pressure zones for water contamination management AU - Strickling, Hayden AU - DiCarlo, Morgan Faye AU - Shafiee, M. Ehsan AU - Berglund, Emily T2 - Sustainable Cities and Society AB - A sustainably managed city should implement strategies to mitigate water distribution contamination events and warn consumers. A modeling framework is developed to assess management strategies for issuing warnings via wireless emergency alerts (WEA) and isolating a contaminant by manipulating pumps and hydrants. A pressure zone-based paradigm divides a service area into sub-sections of similar pressures and is used to target WEA messages and contain and flush contaminant within affected zones. The framework couples a hydraulic model of a pipe network with an agent-based model of utility operators, who implement management strategies, and of consumers, who receive messages, comply with alerts, reduce water use, and communicate about the hazard. The framework is applied for a hypothetical city to test management strategies for two water contamination events. Targeted messages mitigate the loss of access to water supplies and perform similar to citywide messages in reducing the number of exposed consumers, when combined with containment operations. When warnings are used alone, citywide warnings protect more consumers compared with targeted broadcasts. Warnings may perform better than containment alone at times when critical social dynamics, such as ingestion of water and travel among pressure zones, coincide with the movement of a contaminant plume. DA - 2020/1// PY - 2020/1// DO - 10.1016/j.scs.2019.101820 VL - 52 SP - 101820 J2 - Sustainable Cities and Society LA - en OP - SN - 2210-6707 UR - http://dx.doi.org/10.1016/j.scs.2019.101820 DB - Crossref KW - SMS text KW - Wireless emergency alerts KW - Pressure zones KW - Water distribution system management KW - Security ER - TY - JOUR TI - Modeling cell aggregate morphology during aerobic granulation in activated sludge processes reveals the combined effect of substrate and shear AU - Wu, Jun AU - Reyes, , III AU - Ducoste, Joel J. T2 - Water Research AB - Past research on AGS (aerobic granular sludge technology) has mainly focused on macro-environment factors, such as settling time, feeding pattern, OLR (organic loading rate), SRT (sludge retention time), among others, and their effects on the granulation process. The biomass granulation process, however, is significantly affected by the micro-environment surrounding these biomass aggregates. In this research, an in silico computational approach was adopted to study the impact of the micro-environment on the biomass granulation process. A 2-D biofilm model based on the cellular automata algorithm and computational fluid dynamics was used to simulate the development of an individual biomass aggregate under specific hydrodynamic and substrate availability conditions. The simulation results indicated that shear and bulk substrate concentration combined to create the optimal conditions for aerobic granule formation. This process can be characterized by the RT (reversed Thiele) modulus value, which is the ratio of the maximum substrate transport over the maximum substrate reaction rate and an indicator of substrate availability. For AGS formation, the RT value should be greater than 0.1. Many common strategies, such as the application of batch reactors, selection for slow-growing microorganism, F/M (food/mass) ratio adjustment, feast and famine condition, and short settling time, for biomass granulation production can be explained by the RT value. The results suggest that rethinking unit process configurations in wastewater treatment facilities will be required to achieve reliable AGS formation. DA - 2020/3// PY - 2020/3// DO - 10.1016/j.watres.2019.115384 VL - 170 IS - 115384 SP - 115384 UR - https://doi.org/10.1016/j.watres.2019.115384 KW - Aerobic granular sludge KW - Computational fluid dynamics KW - Substrate transport KW - Activated sludge KW - Biofilm modelling ER - TY - JOUR TI - Critical Factors for Improving Reliability of Project Control Metrics throughout Project Life Cycle AU - Orgut, Resulali E. AU - Batouli, Mostafa AU - Zhu, Jin AU - Mostafavi, Ali AU - Jaselskis, Edward J. T2 - JOURNAL OF MANAGEMENT IN ENGINEERING AB - A lack of consistent, reliable, and objective metrics and indicators for project controls poses major challenges for effectively measuring project progress and performance in the construction industry. Often, project managers are misled in their perceptions of project performance until the project nears its end. This lack of accurate project progress and performance information is a major issue that causes performance shortcomings and resource shortfalls. This study investigated critical factors for improving the reliability of project control systems throughout the construction project life cycle. Through conducting a survey and 10 in-depth case studies, this research identified 15 critical reliability improvement factors and 85 indicators with specific application timing and milestones. This robust framework for improving the reliability of project controls throughout the life cycle of a project was then validated by a panel of experts. The results of this study address an important gap related to the understanding of the key factors and indicators that contribute to the reliability of project control metrics and methods. Findings of this research may provide construction industry stakeholders with a tool to significantly improve the reliability of project progress and performance assessment practices. DA - 2020/1/1/ PY - 2020/1/1/ DO - 10.1061/(ASCE)ME.1943-5479.0000710 VL - 36 IS - 1 SP - SN - 1943-5479 KW - Project controls KW - Reliability improvement KW - Cost and schedule assessment ER - TY - JOUR TI - Improved interpretation of asphalt binder parallel plate dynamic shear rheometer fatigue tests AU - Safaei, Farinaz AU - Castorena, Cassie T2 - INTERNATIONAL JOURNAL OF PAVEMENT ENGINEERING AB - The time sweep test, consisting of cyclic, torsional loading in the dynamic shear rheometer (DSR), has been employed for the fatigue characterisation of asphalt binders. The parallel plate geometry imposes radially inhomogeneous strain field, which results in a radial inhomogeneous stress field. Past efforts have inferred fatigue damage in DSR tests based on monitoring the apparent edge stress, which is calculated using linear radial mapping to the total torque. The assumption of linear variation in the shear stress response with radial distance from the specimen centre is erroneous of material or geometric nonlinearities such as cracking. To improve the interpretation of parallel plate fatigue tests, a means to account for the non-linear radial gradient in stress response is derived using simplified viscoelastic continuum damage (S-VECD) modelling. The developed methodology is validated through comparison to cone and plate results where the stress state is uniform. The results demonstrate that the developed methodology allows for accurate determination of S-VECD model coefficients using parallel plate testing alone. DA - 2020/1/2/ PY - 2020/1/2/ DO - 10.1080/10298436.2018.1438611 VL - 21 IS - 1 SP - 74-87 SN - 1477-268X KW - Asphalt binder KW - fatigue KW - dynamic shear rheometer KW - modelling KW - nonlinearity ER - TY - JOUR TI - Towards an improved understanding of greenhouse gas emissions and fluxes in tropical peatlands of Southeast Asia T2 - Sustainable Cities and Society AB - At present, there is insufficient data to understand the processes driving emissions and fluxes of greenhouse gases (GHGs) from tropical peatlands in Southeast Asia (SEA). In this review, we discuss fundamental factors controlling emissions of major GHGs (CO2, CH4, and N2O) from tropical peatlands and their contribution to global climate change. Classifying peatlands in tropical and subtropical regions can aid in understanding their emission characteristics. The applicability of existing GHG emission factors to land use categories in SEA is discussed. We find that rewetting peatland can increase CH4 emissions, and therefore more studies are needed to establish whether peatlands act as a net sink or net sources of GHGs. Few studies have investigated the effectiveness of liming towards reducing peat soil acidity. The review also finds that there is limited data on CO2 concentrations in drainage and wildfire areas, N2O fluxes in agriculture areas, and the impact and reduction of CH4 in tropical peatlands. Addressing these research gaps could support the development of a framework for GHG emission measurements and abatement in tropical peatlands. DA - 2020/2// PY - 2020/2// DO - 10.1016/j.scs.2019.101881 UR - http://dx.doi.org/10.1016/j.scs.2019.101881 KW - Peatsoil KW - Water management system KW - Greenhouse gases KW - Emission fluxes KW - Global climate change ER - TY - JOUR TI - Increased loading stress leads to convergence of microbial communities and high methane yields in adapted anaerobic co-digesters AU - Wang, Ling AU - Hossen, Elvin H. AU - Aziz, Tarek N. AU - Ducoste, Joel J. AU - de los Reyes, Francis L., III T2 - Water Research AB - Enhancing biogas production, while avoiding inhibition of methanogenesis during co-digestion of grease interceptor waste (GIW), can help water resource recovery facilities reduce their carbon footprint. Here we used pre-adapted and non-adapted digesters to link microbial community structure to digester function. Before disturbance, the pre-adapted and non-adapted digesters showed similar methane production and microbial community diversity but dissimilar community composition. When exposed to an identical disturbance, the pre-adapted digester achieved better performance, while the non-adapted digester was inhibited. When re-exposed to disturbance after recovery, communities and performance of both digesters converged, regardless of the temporal variations. Co-digestion of up to 75% GIW added on a volatile solids (VS) basis was achieved, increasing methane yield by 336% from 0.180 to 0.785 l-methane/g-VS-added, the highest methane yield reported to date for lipid-rich waste. Progressive perturbation substantially enriched fatty acid-degrading Syntrophomonas from less than 1% to 24.6% of total 16S rRNA gene sequences, acetoclastic Methanosaeta from 2.3% to 11.9%, and hydrogenotrophic Methanospirillum from less than 1% to 6.6% in the pre-adapted digester. Specific hydrolytic and fermentative populations also increased. These ecological insights demonstrated how progressive perturbation can be strategically used to influence methanogenic microbiomes and improve co-digestion of GIW. DA - 2020/2// PY - 2020/2// DO - 10.1016/j.watres.2019.115155 VL - 169 SP - 115155 J2 - Water Research LA - en OP - SN - 0043-1354 UR - http://dx.doi.org/10.1016/j.watres.2019.115155 DB - Crossref KW - Anaerobic co-digestion KW - Grease interceptor waste KW - Fat, oil and grease (FOG) KW - Perturbation KW - Adaptation history KW - Microbial community dynamics ER - TY - JOUR TI - Advancements in the characterisation and design of asphalt materials AU - Underwood, Shane AU - Caro, Silvia AU - Varveri, Aikaterini T2 - INTERNATIONAL JOURNAL OF PAVEMENT ENGINEERING AB - "Advancements in the characterisation and design of asphalt materials." International Journal of Pavement Engineering, 21(8), p. 955 DA - 2020/7/2/ PY - 2020/7/2/ DO - 10.1080/10298436.2019.1650928 VL - 21 IS - 8 SP - 955-955 SN - 1477-268X ER - TY - JOUR TI - Environmental and economic impacts of solar-powered integrated greenhouses AU - Hollingsworth, Joseph A. AU - Ravishankar, Eshwar AU - O'Connor, Brendan AU - Johnson, Jeremiah X. AU - DeCarolis, Joseph F. T2 - JOURNAL OF INDUSTRIAL ECOLOGY AB - Abstract Greenhouse vegetable production plays a vital role in providing year‐round fresh vegetables to global markets, achieving higher yields, and using less water than open‐field systems, but at the expense of increased energy demand. This study examines the life cycle environmental and economic impacts of integrating semitransparent organic photovoltaics (OPVs) into greenhouse designs. We employ life cycle assessment to analyze six environmental impacts associated with producing greenhouse‐grown tomatoes in a Solar PoweRed INtegrated Greenhouse (SPRING) compared to conventional greenhouses with and without an adjacent solar photovoltaic array, across three distinct locations. The SPRING design produces significant reductions in environmental impacts, particularly in regions with high solar insolation and electricity‐intensive energy demands. For example, in Arizona, global warming potential values for a conventional, adjacent PV and SPRING greenhouse are found to be 3.71, 2.38, and 2.36 kg CO 2 eq/kg tomato, respectively. Compared to a conventional greenhouse, the SPRING design may increase life cycle environmental burdens in colder regions because the shading effect of OPV increases heating demands. Our analysis shows that SPRING designs must maintain crop yields at levels similar to conventional greenhouses in order to be economically competitive. Assuming consistent crop yields, uncertainty analysis shows average net present cost of production across Arizona to be $3.43, $3.38, and $3.64 per kg of tomato for the conventional, adjacent PV and SPRING system, respectively. DA - 2020/2// PY - 2020/2// DO - 10.1111/jiec.12934 VL - 24 IS - 1 SP - SN - 1530-9290 KW - food systems KW - greenhouse KW - industrial ecology KW - life cycle assessment (LCA) KW - organic solar cells KW - sustainable agriculture ER - TY - JOUR TI - Analysis of Three Sign Management Program Case Studies AU - Machado, Patricia AU - Rasdorf, William T2 - PUBLIC WORKS MANAGEMENT & POLICY AB - Traffic signs play a major role on the national highway system because they provide users with important information such as warnings, regulations, and directions. To ensure sign visibility at night, the Manual on Uniform Traffic Control Devices (MUTCD) requires transportation agencies to meet minimum sign retroreflectivity levels through a sign maintenance program. To better understand current trends, the researchers conducted an extensive literature search that showed that expected sign life and nighttime inspection are the most used methods, followed by blanket replacement. The literature does not typically discuss how these methods are implemented. Thus, the research team also contacted three of the four largest state-maintained highway systems in the United States (North Carolina, Virginia, and South Carolina) to discuss sign maintenance programs, implementation issues, and best practices. The authors describe in this article the findings and conclusions drawn from these case studies that may help other agencies improve their sign maintenance practices. DA - 2020/1// PY - 2020/1// DO - 10.1177/1087724X19862285 VL - 25 IS - 1 SP - 51-74 SN - 1552-7549 KW - sign maintenance KW - sign service life KW - blanket replacement KW - sign management practices KW - transportation asset management ER - TY - CHAP TI - A simple Hybrid Event-B model of an active control system for earthquake protection AU - Banach, Richard AU - Baugh, John T2 - From Astrophysics to Unconventional Computation A2 - Adamatzky, Andrew A2 - Kendon, Vivien AB - In earthquake-prone zones of the world, severe damage to buildings and life endangering harm to people pose a major risk when severe earthquakes happen. In recent decades, active and passive measures to prevent building damage have been designed and deployed. A simple model of an active damage prevention system, founded on earlier work, is investigated from a model based formal development perspective, using Hybrid Event-B. The non-trivial physical behaviour in the model is readily captured within the formalism. However, when the usual approximation and discretization techniques from engineering and applied mathematics are used, the rather brittle refinement techniques used in model based formal development start to break down. Despite this, the model developed stands up well when compared via simulation with a standard approach. The requirements of a richer formal development framework, better able to cope with applications exhibiting non-trivial physical elements are discussed. PY - 2020/// DO - 10.1007/978-3-030-15792-0_7 VL - 35 SP - 157-194 PB - Springer ER -