TY - JOUR TI - Ammonia Fate and Transport Mechanisms in Broiler Litter AU - Liang, Wei-zhen AU - Classen, John J. AU - Shah, Sanjay B. AU - Sharma-Shivappa, Ratna T2 - Water, Air, & Soil Pollution DA - 2013/12/3/ PY - 2013/12/3/ DO - 10.1007/s11270-013-1812-x VL - 225 IS - 1 J2 - Water Air Soil Pollut LA - en OP - SN - 0049-6979 1573-2932 UR - http://dx.doi.org/10.1007/s11270-013-1812-x DB - Crossref ER - TY - CONF TI - Fruit and Vegetable AU - Simmons, O.D., III AU - Jaykus, L.A. T2 - International Association for Food Protection Annual Meeting C2 - 2013/// CY - Charlotte, NC DA - 2013/// PY - 2013/// ER - TY - CONF TI - Experimental and numerical evaluation of a UV-LED point of use device AU - Jenny, R.M. AU - Simmons, O.D., III AU - Ducoste, J.J. T2 - 93rd Annual Conference American Water Works Association and the Association of the Water Environment Federation, North Carolina Section C2 - 2013/11/10/ CY - Concord, NC DA - 2013/11/10/ PY - 2013/11/10/ ER - TY - SOUND TI - Viruses in Shellfish and other Foods: Are they really that important?? AU - Simmons, O.D., III AU - Jaykus, L.A. DA - 2013/// PY - 2013/// M3 - Webinar ER - TY - SOUND TI - Food Safety in the United States: Current Trends AU - Simmons, O.D., III DA - 2013/// PY - 2013/// ER - TY - SOUND TI - Viruses in Shellfish: What all Commercial Fishermen Should Know!” AU - Simmons, O.D., III AU - Jaykus, L.A. DA - 2013/1/18/ PY - 2013/1/18/ ER - TY - SOUND TI - Viruses in Fresh Produce: What Every Producer Should Know! AU - Simmons, O.D., III AU - Jaykus, L.A. DA - 2013/1/10/ PY - 2013/1/10/ ER - TY - SOUND TI - What’s that in your pomegranate seeds?? Recent microbial threats linked to fresh fruits and vegetables. AU - Simmons, O.D., III DA - 2013/// PY - 2013/// ER - TY - CONF TI - The Cysticidal Activity of Bromine on Cryptosporidium parvum Oocysts AU - Kim, J.J. AU - Simmons, O.D., III AU - Sobsey, M.D. T2 - American Water Works Association, Water Quality and Technology Conference C2 - 2013/11/3/ CY - Long Beach, CA DA - 2013/11/3/ PY - 2013/11/3/ ER - TY - CONF TI - The Cysticidal Activity of Bromine on Cryptosporidium parvum Oocysts AU - Kim, J.J. AU - Simmons, O.D., III AU - Sobsey, M.D. T2 - 113th American Society for Microbiology General Meeting C2 - 2013/5/18/ CY - Denver, CO DA - 2013/5/18/ PY - 2013/5/18/ ER - TY - CONF TI - Seafood Safety AU - Simmons, O.D., III AU - Jaykus, L.A. T2 - International Association for Food Protection Annual Meeting C2 - 2013/7/28/ CY - Charlotte, NC DA - 2013/7/28/ PY - 2013/7/28/ ER - TY - SOUND TI - Seafood Safety AU - Simmons, O.D., III AU - Jaykus, L.A. DA - 2013/7/28/ PY - 2013/7/28/ UR - https://www.foodprotection.org/annualmeeting/archive/2013/ ER - TY - CONF TI - Prevalence and diversity of Salmonella associated with North Carolina tomato growing environments AU - Ducharme, D. AU - Zheng, J. AU - Allard, S.E. AU - Burrows, W. AU - Wang, C.Y. AU - Arce, G.C. AU - Muruvanda, T. AU - Keys, C.E. AU - Melka, D. AU - Simmons, O.D., III AU - Perkins-Veazie, P. AU - Brown, E.W. AU - Bell, R.L. AU - Gunter, C.G. T2 - 113th American Society for Microbiology General Meeting C2 - 2013/5/18/ CY - Denver, CO DA - 2013/5/18/ PY - 2013/5/18/ ER - TY - CONF TI - Water Safety and Quality AU - Simmons, O.D., III AU - Jaykus, L.A. T2 - International Association for Food Protection Annual Meeting C2 - 2013/7/28/ CY - Charlotte, NC DA - 2013/7/28/ PY - 2013/7/28/ ER - TY - CONF TI - Incidence and Persistence of Salmonella and Escherichia coli in Environmental Samples from North Carolina Tomato Production Systems AU - Ducharme, D. AU - Gunter, C. AU - Jaykus, L. AU - Perkins-Veazie, P. AU - Simmons, O.D., III AU - Zheng, J. AU - Burrows, E. AU - Wang, C. AU - Arce, G.C. AU - Muruvanda, T. AU - Bell, R. AU - Brown, E. T2 - International Association for Food Protection Annual Meeting C2 - 2013/7/28/ CY - Charlotte, NC DA - 2013/7/28/ PY - 2013/7/28/ ER - TY - CONF TI - Updates on NoroCORE activities for IAFP Professional Development Groups (PDGs)” AU - Simmons, O.D., III AU - Jaykus, L.A. T2 - International Association for Food Protection Annual Meeting C2 - 2013/7/28/ CY - Charlotte, NC DA - 2013/7/28/ PY - 2013/7/28/ ER - TY - SOUND TI - Enhancing Food Security through Pre-Harvest Food Safety: Current Research and Outreach for Practical Solutions AU - Simmons, O.D., III DA - 2013/11/5/ PY - 2013/11/5/ ER - TY - SOUND TI - Incidence and Persistence of Salmonella and Escherichia coli in Environmental Samples from North Carolina Tomato Production Systems. AU - Ducharme, D. AU - Gunter, C. AU - Jaykus, L.A. AU - Perkins-Veazie, P. AU - Simmons, O.D., III AU - Zheng, J. AU - Burrows, E. AU - Wang, C. AU - Arce, G.C. AU - Muruvanda, T. AU - Bell, R. AU - Brown, E. DA - 2013/8/8/ PY - 2013/8/8/ ER - TY - JOUR TI - Advanced rainwater harvesting and stormwater AU - Hunt, William T2 - Journal of Chemical Health and Safety DA - 2013/5// PY - 2013/5// DO - 10.1016/J.JCHAS.2013.03.407 VL - 20 IS - 3 SP - 42 J2 - Journal of Chemical Health and Safety LA - en OP - SN - 1871-5532 UR - http://dx.doi.org/10.1016/J.JCHAS.2013.03.407 DB - Crossref ER - TY - CONF TI - Partitioning Pre-Development Hydrology in Order to Mimic Pre-Development Water Quality AU - Cizek, Adrienne R. AU - Hunt, III, William F. T2 - World Environmental and Water Resources Congress 2013 AB - The primary objective of Low Impact Development (LID) is to maintain pre-development hydrology. This has been achieved by matching the magnitude and duration of pre- and post-development hydrographs. Research on undeveloped watersheds show that stream storm hydrographs are composed of water from one of three pathways: 1) surface runoff, 2) shallow interflow, or 3) groundwater surge. Each of these pathways offers different treatment benefits and is thus essential for optimal nutrient reduction. Stormwater Control Measures (SCMs) providing opportunities for each of these pathways may be better able to mimic pre-development hydrology, particularly in terms of water quality. This research aims to partition the pre-development hydrograph and estimate pre-development water quality. Previous studies on forested watersheds are referenced to establish target hydrograph fractions. Ultimately, this research better defines the goal of pre-development hydrology, while suggesting SCM characteristics to provide opportunities to best mimic pre-development conditions. C2 - 2013/5/28/ C3 - World Environmental and Water Resources Congress 2013 DA - 2013/5/28/ DO - 10.1061/9780784412947.025 PB - American Society of Civil Engineers SN - 9780784412947 UR - http://dx.doi.org/10.1061/9780784412947.025 DB - Crossref ER - TY - CONF TI - Using temperature as a tracer for analyzing the response of a capillary barrier in waste rock AU - Broda, S. AU - Sayde, C. AU - Selker, J. AU - Aubertin, M. AU - Blessent, D. T2 - 66th Canadian Geotechnical Conference C2 - 2013/// C3 - 66th Canadian Geotechnical Conference CY - Montreal, Quebec, Canada DA - 2013/// PY - 2013/9/29/ VL - 29 ER - TY - RPRT TI - Dune infiltration systems for reducing stormwater discharge to coastal recreational beaches AU - Burchell, M.R. AU - Hunt, W.F. AU - Price, W.D. A3 - North Carolina Cooperative Extension Publication DA - 2013/// PY - 2013/// M1 - AG-781 M3 - NC State Extension Publications PB - North Carolina Cooperative Extension Publication SN - AG-781 ER - TY - RPRT TI - Field Evaluation of Restored Wetlands in North Carolina Using Floristic Indices, Rapid Assessments, and Environmental Parameters AU - Fernandez, M.B. AU - Burchell, M.R. AU - Jennings, G. A3 - Environmental Law Institute DA - 2013/// PY - 2013/// M3 - Final Report PB - Environmental Law Institute ER - TY - CONF TI - Investigating Whether or Not Constructed Stormwater Wetlands Need Maintenance to Sustain Performance and the Effect of Vegetation Occupancy in the Designed Storage Volume AU - Merriman, L. S. AU - Hunt, W. F. T2 - World Environmental and Water Resources Congress 2013 AB - Stormwater wetlands (CSWs) have become one of the more popular SCMs, offering a hybrid between larger detention technologies such as wet ponds and newer green infrastructure technologies. A well-functioning stormwater wetland will be a resilient, diverse ecosystem that includes many plant and animal species. This research looks to investigate whether or not wetlands need regular maintenance to sustain their treatment capacity. The research site is located in River Bend, NC. Flow-weighted samples, rainfall, and hydrologic data are being collected at both the inlet and outlet from April 2012 - April 2013, aiming a minimum of 15 storms spaced throughout the year. Monitoring of phosphorus deposition consists of taking soil samples and analyzing for Soil Test Phosphorous. These monitoring results will be compared with the results of a study that was conducted at the same site for a one-year period immediately following construction completion. This will allow researchers to see the effects of no maintenance plan (or activity) and time on wetland performance in removing phosphorus and achieving other wetland performance goals. Vegetation in a CSW is essential for nutrient removal and thermal pollution reduction. However, a portion of the storage volume designed to retain the water quality event is occupied by vegetation, which may result in the CSW being undersized from a hydrologic perspective - especially in unmaintained, mature systems. The fraction of the volume associated with vegetation mass was unknown, and designers have been unsure as to (1) how they should account for volume occupied by vegetation and (2) whether this was a significant design issue. Twelve stormwater wetlands and one hybrid wet pond in North Carolina were sampled to assess their percent vegetative occupancy by volume. A conservative recommended factor of safety is 1.025. Species-specific factors of safety (FOS) were also calculated; at the 30 cm temporary pool elevation, the Iris (Iris spp.) FOS was highest at 1.020 and the mixed vegetation FOS was lowest at 1.005. When designing a wetland, a more specific FOS may be calculated using a weighted average of the FOS for each species in the planting plan. The outcomes of this research allow designers to account for the volume taken up by emergent wetland vegetation; however, the uncertainty in other factors such as discrepancies between designed and as-built bathymetry probably have a greater impact on the design volume loss when compared with vegetation occupancy (<2%). C2 - 2013/5/28/ C3 - World Environmental and Water Resources Congress 2013 DA - 2013/5/28/ DO - 10.1061/9780784412947.293 PB - American Society of Civil Engineers SN - 9780784412947 UR - http://dx.doi.org/10.1061/9780784412947.293 DB - Crossref ER - TY - CONF TI - A decision support system (DSS) for biomass-to-biofuel supply chain AU - Acharya, A. AU - Gonzales, D. AU - Eksioglu, S. T2 - 1st International Symposium on Computing in Informatics and Mathematics. C2 - 2013/// C3 - Proceedings of the 1st International Symposium on Computing in Informatics and Mathematics CY - Tirana-Durres, Albania DA - 2013/// PY - 2011/6/2/ ER - TY - CONF TI - Carbon Sequestration by Roadside Filter Strips and Swales: A Field Study AU - Winston, R. J. AU - Bouchard, N. R. AU - Hunt, W. F. T2 - Second Conference on Green Streets, Highways, and Development AB - As legislation continues to focus on greenhouse gas (GHG) and carbon dioxide (CO2) emissions and reductions, the terrestrial biome offers an attractive possibility to sequester carbon. Currently, the terrestrial pool is regarded as a CO2 sink, but scientists are unsure to what extent this trend will continue. Urbanization modifies the existing landscape, and little study has focused on the carbon (C) dynamics of specific urban land uses. In this research, the roadway environment, specifically the grassed right of way (ROW), was studied for carbon sequestration potential, an important ecosystem service. Transportation corridors exist worldwide, and the vegetated filter strip and swale (VFS/VS), two common stormwater control measures (SCMs), often constitute the grassed right of way adjacent to roadways. Carbon pools within roadway VFS/VS soils of North Carolina were specifically examined in this study. This research was conducted in two North Carolina physiographic regions: the Piedmont (characterized by clay-influenced soils) and the Coastal Plain (predominantly sandy soils). Approximately 700 soil samples were collected in VFS/VSs and wetland swales alongside major highways and analyzed for percent total soil C (% total C) and bulk density, which aided in obtaining the C density. Mean soil C densities were 2.55 ± 0.13 kg C m-2 (mean ± standard error, n=160, 0.2 m depth) in the Piedmont and 4.14 ± 0.15 kg C m-2 (n=160, 0.2 m depth) in Coastal Plain highway VFS/VSs. Because grasslands were reported to have similar carbon density values, they could be used as a surrogate land use for roadway VFS/VSs if no specific roadside data were available. Using a 37-year soil chronosequence, the carbon sequestration rate using a simple linear regression within Piedmont VFS/VSs was calculated at 0.053 kg C m-2 yr-1. Utilizing segmented linear regression models, the sequestration rate was calculated to be 0.155 kg C m-2 yr-1 for 15 years and 0.099 kg C m-2 yr-1 for the remaining 21.5 years. The roadside grass sequestration rate assumed by the Federal Highway Administration Carbon Sequestration Pilot Program (0.17 kg C m-2 yr-1) overestimates carbon accumulation by a factor of 3 in the linear model, and by a factor of 1.1 to 1.7 with the segmented linear models. Carbon density did not differ between dry and wetland swales, although % total C was significantly greater in wetland swales. Because C density and % total C in swales were not well defined by age, it appeared more appropriate to assess wetland swales and dry swales using a range of carbon values, rather than a rate of carbon sequestration. The mean VS C density was 3.05 ± 0.13 kg C m-2 (n=40, 0.2 m depth), while that for wetland swales was 5.04 ± 0.73 kg C m-2 (n=44, 0.2 m depth). If promoting C sequestration becomes a factor in ROW management, wetland swales would be more desirable than dry swales. While the VFS/VS sequestration rate is comparable to other grassed systems, the estimated 320-480 tons C per lane-mile expelled during roadway construction (Cass and Mukherjee 2011) is marginally offset through terrestrial sequestration in roadside VFS/VSs. Per kilometer of roadway constructed, Piedmont VFS/VSs would offset between 4% and 7% of C emitted during construction, depending on predictive model of C sequestration rate was used. C2 - 2013/11/2/ C3 - Green Streets, Highways, and Development 2013 DA - 2013/11/2/ DO - 10.1061/9780784413197.028 PB - American Society of Civil Engineers SN - 9780784413197 UR - http://dx.doi.org/10.1061/9780784413197.028 DB - Crossref ER - TY - CONF TI - Catchment Scale Hydrologic and Water Quality Impacts of Residential Stormwater Street Retrofits in Wilmington, North Carolina AU - Winston, R. J. AU - Page, J. L. AU - Hunt, W. F. T2 - Second Conference on Green Streets, Highways, and Development AB - Low impact development (LID) is a design approach that utilizes stormwater control measures (SCMs) to maintain and restore the natural hydrologic regime of an urban watershed through infiltration, runoff treatment at the source, and minimization of impervious surfaces. This paired watershed study evaluated the impacts of LID SCMs on hydrology and water quality at a catchment scale. In February 2012, a pair of bioretention cell (BRC) bumpouts, two permeable pavement parking stalls, and a tree filter device were installed to treat residential street runoff in Wilmington, North Carolina. In the LID-retrofit catchment, SCMs treated 52% of the directly connected impervious area (DCIA) and 69% of the total drainage area for potential mitigation of peak discharge and runoff volume. For water quality improvement, 94% of the DCIA and 91% of the total drainage area was retrofitted. Underlying soils in the study area were Baymeade Urban and Leon Urban sands. Mean peak discharge significantly decreased 28% post-retrofit and lag times in the catchment remained unchanged, while mean runoff depth significantly decreased 52%. When compared with the control catchment, runoff depths in the LID-retrofit catchment were significantly less for storms with low hourly storm intensities (<2.7 mm/hr), but significantly greater for storms with high intensities (>7.4 mm/hr). Runoff thresholds in the LID-retrofit and control catchments were 5.2 mm and 3.5 mm, respectively. The LID runoff coefficient significantly decreased by 47% from 0.22 to 0.13 and is substantially less than other runoff coefficients reported for traditional residential development. Post-retrofit concentrations of TKN, TP, TSS, Cu, Pb, and Zn significantly decreased by 62%, 38%, 82%, 55%, 89%, and 76%, respectively. Concentrations of NO2,3-N and TAN did not change. Mass exports of TKN, TAN, O-PO4-3, TP, TSS, Cu, Pb, and Zn significantly decreased by 78%, 61%, 55%, 73%, 91%, 53%, 88%, and 77%, respectively. NO2,3-N load decreased by 46%, although this was not significant. Most improvements in water quality were due to dramatic decreases of particulate and particulate-bound pollutant loads. This was attributed to first flush retention of runoff by the BRC and permeable pavement that treated 52% of the DCIA and treatment by the tree filter unit that serviced 42% of the DCIA. This study has shown that a limited number of LID SCMs installed within a medium density residential street right-of-way over sandy soils can mitigate some hydrologic and water quality impacts of existing development. C2 - 2013/11/2/ C3 - Green Streets, Highways, and Development 2013 DA - 2013/11/2/ DO - 10.1061/9780784413197.014 PB - American Society of Civil Engineers SN - 9780784413197 UR - http://dx.doi.org/10.1061/9780784413197.014 DB - Crossref ER - TY - CONF TI - Water Quality and Hydrologic Performance of a Permeable Pavement-Modular Bioretention Treatment Train and a Stormwater Filter Box in Fayetteville, North Carolina AU - Anderson, A. R. AU - Hunt, W. F. AU - Smolek, A. P. T2 - World Environmental and Water Resources Congress 2013 AB - Impervious land cover in urban developments is commonly responsible for degraded water quality and potentially erosive flow rates on downstream water bodies. Many environmental products have recently been developed to satisfy the niche in the market for easy-to-retrofit stormwater practices; however, data on the field performance of these novel stormwater control measures to reduce runoff and improve water quality are limited. Given tight site constraints, retrofitting traditional pavement with pervious pavement provides numerous water quality and hydrologic benefits. This, coupled with other treatment devices as part of a "treatment train," is becoming a valuable option to reduce a site's stormwater footprint. A permeable interlocking concrete paver (PICP) system that drains to a 1.2 m by 1.2 m Filterra® bioretention retrofit was installed at an AmtrakTM parking lot in Fayetteville, North Carolina. With a catchment-to-footprint ratio of 2.5:1, the system is designed to mitigate the 10-year storm and filter any runoff that does not infiltrate into the sandy-loam subsoil of the PICP. Additionally, a standalone, conventional Filterra® modular bioretention cell was installed on the property to mitigate impervious runoff through a curb throat. Water quality, flow, and ponding level will be monitored at five locations, including (1) impervious asphalt before the PICP, (2) underdrain leaving the PICP and entering the Filterra, (3) underdrain leaving the Filterra, (4) impervious asphalt before the conventional Filterra, and (5) the underdrain pipe leaving the conventional Filterra. Using flow-paced automatic sampling, the above locations will be monitored for total phosphorus, ortho phosphorus, total soluble phosphorus, nitrate and nitrite, Total Kjeldahl Nitrogen, total ammoniated nitrogen, total nitrogen, particle size distribution, total suspended solids, suspended sediment concentration, specific gravity, copper (Cu), zinc (Zn), and total petroleum hydrocarbons. The goal of this study is to assess the pollutant-removal performance and hydrologic mitigation ability of both proprietary treatment devices and to use these data to model PICP dynamics. C2 - 2013/5/28/ C3 - World Environmental and Water Resources Congress 2013 DA - 2013/5/28/ DO - 10.1061/9780784412947.300 PB - American Society of Civil Engineers SN - 9780784412947 UR - http://dx.doi.org/10.1061/9780784412947.300 DB - Crossref ER - TY - CONF TI - A Comparison of Runoff Quality and Quantity from a Urban Commercial Infill Low Impact Development and a Conventional Development AU - Wilson, C. E. AU - Hunt, W. F. AU - Winston, R. J. AU - Smith, P. K. T2 - World Environmental and Water Resources Congress 2013 AB - Urbanization and its associated increased impervious footprint lead to stream impairment through erosion, flooding, and augmented pollutant loads. Low Impact Development (LID) focuses on disconnecting impervious areas, increasing infiltration and evapotranspiration, and reusing stormwater on site through the use of stormwater control measures (SCMs). SCMs, such as bioretention, rainwater harvesting, and permeable pavement, can be used independently or in series to mimic pre-development hydrology. In this study, a conventional development (centralized stormwater management) and a nearby infiltration-based LID commercial site in Raleigh, North Carolina, were compared with respect to stormwater quality and quantity. The conventional development (2.76 ha, 61% directly connected impervious area (DCIA)) and the LID (2.53 ha, 84% DCIA) have underlying hydrologic soil group B soils. A dry detention basin, designed to mitigate peak flow rate, was the conventional development SCM. The LID site consisted of a 44,300-liter aboveground cistern used for indoor toilet flushing, two underground cisterns (57,900 liters and 60,600 liters used for landscape irrigation), and an underground detention system, which overflowed into a series of infiltration galleries beneath the parking lot of the shopping center. The LID shopping center was intended to mimic pre-development hydrology from a runoff perspective for the 10-year return period, 24-hour duration storm. For the 50 hydrologic storms monitored, a mean runoff reduction of 98.1% at the LID site, and a 48.9% mean runoff reduction at the conventional site, when normalized by DCIA. The conventional development had a 9x higher peak flow value, on average, than the LID site when normalized by DCIA. Flow-proportional, composite water quality samples were analyzed for total nitrogen (TN), total phosphorus (TP), total Kjeldahl nitrogen (TKN), ammonia (NH3-N), nitrite-nitrate (NO2+3-N), orthophosphate (PO4-3) and total suspended solids (TSS). For the 19 water quality storms sampled, the LID site pollutant loadings for all species studied were less than 9% of pollutant loadings of the conventional site. Results from this innovative combined detention, stormwater reuse, and infiltration LID system will provide space-saving solutions for areas where aboveground SCMs, such as bioretention and constructed stormwater wetlands, are not feasible due to high land costs and constricted spaces. C2 - 2013/5/28/ C3 - World Environmental and Water Resources Congress 2013 DA - 2013/5/28/ DO - 10.1061/9780784412947.288 PB - American Society of Civil Engineers SN - 9780784412947 UR - http://dx.doi.org/10.1061/9780784412947.288 DB - Crossref ER - TY - CONF TI - Monitoring of Representative Particle Size Distributions and Gross Solids from Roadways and Application to SCM Design AU - Winston, R. J. AU - Hunt, W. F. T2 - World Environmental and Water Resources Congress 2013 AB - Road runoff treatment is a challenge due to lack of space in the right of way. Therefore, it is imperative to understand the quality of runoff from roadways so that efficient stormwater control measures (SCMs) may be designed. In terms of TSS control, the particle size distribution of sediment in the runoff controls the amount of sediment (based on Stokes' Law) that may be removed through settling in a typical SCM. For best treatment of TSS, the flow depth in vegetated SCMs during the design storm should be limited to the height of the vegetation. Typical roadside stormwater controls (vegetated filter strips and swales) could be designed for water quality by calculating a hydraulic retention time for a particular removal of sediment. To do so, an understanding of average particle size distributions (PSDs) was needed for roads across North Carolina (NC). A field-monitoring study was conducted during May-November 2012 to obtain PSDs from roads in the three ecoregions of NC: mountains, piedmont, and coastal plain. Two sites in the mountains, six in the piedmont, and four in the coastal plain were monitored for TSS concentrations and PSDs for a minimum of six storms apiece. Roadway types were distributed across Interstate highways (six sites), four lane divided highways (one site), four lane primary roads (three sites), and secondary roads (two sites) to determine the effects that annual average daily traffic have on runoff PSDs. At the Interstate highway sites, two monitoring locations had a permeable friction course (PFC) overlay and one site had a NovaChip overlay, which may modify the expected PSD from a highway. Because nutrients are a concern in NC, nutrient concentrations (TN and TP) were monitored at four sites both in the stormwater and sorbed to the sediment. This will allow for modelling of nutrient removal performance for typical roadway SCMs by estimation of TSS removal from Stokes' Law. Gross solids (trash, debris, and particles greater than 5 mm in diameter) are often overlooked in loading of nutrients to waterways. Automated stormwater samplers are not able to capture most gross solids, and total maximum daily loads (TMDLs) for these pollutants have been established for some watersheds. Monitoring for gross solids was undertaken at four sites: one in the mountains, two in the piedmont, and one in the coastal plain. Three sites were Interstate highways while one was a divided four lane highway. Dry mass of gross solids and nitrogen and phosphorus content were determined in the laboratory. It was determined that gross solids are a substantial portion of the nutrient load, and that they cannot be disregarded in stormwater sampling for nutrient load estimation. C2 - 2013/5/28/ C3 - World Environmental and Water Resources Congress 2013 DA - 2013/5/28/ DO - 10.1061/9780784412947.023 PB - American Society of Civil Engineers SN - 9780784412947 UR - http://dx.doi.org/10.1061/9780784412947.023 DB - Crossref ER - TY - CONF TI - Catchment-Scale Evaluation of the Hydrologic and Water Quality Impacts of Residential Street Retrofits in Wilmington, NC AU - Page, J. L. AU - Winston, R. J. AU - Hunt, W. F. T2 - World Environmental and Water Resources Congress 2013 AB - Many urban watersheds suffer from degraded water quality caused by stormwater runoff from rooftops, parking lots, streets, and other impervious surfaces. Low Impact Development (LID) is a design approach that utilizes stormwater control measures (SCMs) to maintain and restore the natural hydrologic features of an urban watershed through infiltration, runoff treatment at the source, and minimization of impervious surfaces. Limited peer-reviewed literature is available on impacts of multiple LID SCMs at a catchment or watershed scale. A paired watershed study with calibration and treatment monitoring periods has been designed to evaluate the hydrologic and water quality impacts of residential street SCMs at a catchment scale in Wilmington, North Carolina. Calibration monitoring of the control (0.35 ha) and retrofit (0.53 ha) catchments was completed from May 2011 to October 2011 (nine water quality samples, 14 rainfall events). In February 2012 bioretention bumpouts, permeable pavement parking stalls, and a tree filter device were installed in the retrofit catchment. Treatment monitoring commenced in June 2012 and will continue through February 2013 (10 water quality samples, 15 rainfall events through November 2012). Water quality, peak discharge, and flow volume are being recorded at the catchment outlets (existing catch basins). Water quality samples will be analyzed for TSS, TKN, NH4-N, NO2-3-N, TP, Ortho-P, Cu, Pb, and Zn. Preliminary results indicate a 14% reduction in mean runoff volume. TSS, TN, and TP mass loads at the retrofit outlet decreased by 83%, 49%, and 63%, respectively, during treatment monitoring. Preliminary water quality and runoff volume results are promising, and results from this project will help refine street retrofit design standards to meet runoff volume reduction and water quality goals. C2 - 2013/5/28/ C3 - World Environmental and Water Resources Congress 2013 DA - 2013/5/28/ DO - 10.1061/9780784412947.013 PB - American Society of Civil Engineers SN - 9780784412947 UR - http://dx.doi.org/10.1061/9780784412947.013 DB - Crossref ER - TY - JOUR TI - Assessing the Importance of Temporary Storage Volume Occupied by Emergent Vegetation in Constructed Storm Water Wetlands AU - Merriman, Laura S. AU - Wilson, Corinne Eileen AU - Winston, Ryan J. AU - Hunt, William F. T2 - Journal of Hydrologic Engineering AB - Vegetation in a constructed storm water wetland (CSW) is essential for nutrient removal and thermal pollution reduction. However, a portion of the storage volume designed to retain the water quality event is occupied by vegetation, which may result in the CSW being undersized from a hydrologic perspective. The fraction of the volume associated with vegetation mass was unknown and designers have been unsure as to (1) how they should account for volume occupied by vegetation and (2) whether this was a significant design issue. Twelve storm water wetlands and one hybrid wet pond in North Carolina were sampled to assess their percent vegetative occupancy by volume. Vegetation was harvested from randomly selected 0.1 m2 grids at the normal pool elevation, and displacement tests were used to calculate the volume added by vegetation at elevations of 30 and 45 cm. Combining these data with observed vegetative cover, a water quality volume factor of safety accounting for vegetative occupancy was calculated for use in CSW design. Of the thirteen practices sampled, the highest factor of safety calculated for temporary pool elevations of 30 and 45 cm are 1.019 and 1.018, respectively. Therefore, a conservative recommended factor of safety is 1.025. Species-specific factors of safety (FOS) were also calculated; at the 30-cm temporary pool elevation, the Iris (Iris spp.) FOS was highest at 1.020, and the mixed vegetation FOS was lowest at 1.005. When designing a wetland, a more specific FOS may be calculated using a weighted average of the FOS for each species in the planting plan. The outcomes of this research allow designers to account for the volume taken up by emergent wetland vegetation; however, the uncertainty in other factors such as discrepancies between designed and as-built bathymetry probably have a greater impact on the design volume loss when compared with vegetation occupancy (<2%). DA - 2013/10// PY - 2013/10// DO - 10.1061/(ASCE)HE.1943-5584.0000713 VL - 18 IS - 10 SP - 1372-1376 J2 - J. Hydrol. Eng. LA - en OP - SN - 1084-0699 1943-5584 UR - http://dx.doi.org/10.1061/(ASCE)HE.1943-5584.0000713 DB - Crossref KW - Stormwater management KW - Wetlands KW - Hybrid methods KW - Vegetation KW - North Carolina KW - Design KW - Water storage KW - Stormwater wetlands KW - Hybrid wet ponds KW - Vegetation KW - Design volume KW - North Carolina ER - TY - CONF TI - Evaluation of the Conservational Channel Evolution and Pollutant Transport System (CONCEPTS) Applied to Composite Streambanks in the Ozark Highlands Ecoregion AU - Daly, Erin R AU - Storm, Daniel E AU - Fox, Garey A AU - Langendoen, Eddy J T2 - 2013 ASABE Annual International Meeting AB - Abstract. Hydraulic models are often employed to predict the response of a stream to a proposed restoration design. The shortfall of many currently used models is that they only look at the site where stabilization will occur without considering upstream and downstream effects. The one-dimensional (1D) computer model Conservational Channel Evolution and Pollutant Transport System (CONCEPTS) addresses this shortcoming by modeling streambank stabilization on a reach scale. The capability of this model is attractive to basin managers; however, CONCEPTS is still an emerging model and has not been applied to a wide variety of composite streambanks. The objectives of this study were to perform an evaluation of the Conservational Channel Evolution and Pollutant Transport System (CONCEPTS) applied to composite streambanks in the Ozark Highlands ecoregion, and to demonstrate CONCEPTS’s ability to predict the long-term stability of streambank stabilization. CONCEPTS was used to simulate a 9.25 km reach along the Barren Fork Creek in northeastern Oklahoma. A sensitivity analysis was first performed to identify input parameters with the greatest effect on bank erosion predictions in CONCEPTS. Model results were most sensitive to (1) the correction factor that accounts for increased shear stresses in a meandering stream that cannot be simulated by 1D models and (2) the internal angle of friction of the bank soils followed by the critical shear stress, effective cohesion, erodibility coefficient and the permeability. Next, CONCEPTS was calibrated using ground-based and aerial bank retreat measurements to produce realistic predictions. Model calibration was conducted by reducing the critical shear stress of the noncohesive soils until the predicted retreat matched the observed data. Using the calibrated model, two streambank stabilization techniques were simulated at two highly unstable cross sections. Fluvial erosion was reduced by simulating the application of riprap at the bank toe, and geotechnical failure was reduced by simulating a slope stabilization technique. In general, CONCEPTS predicted a high percent reduction of cumulative fines yield, bank retreat at the bank top and toe, and cumulative change in thalweg elevation for both stabilization techniques. Due to CONCEPTS limitations, a two or three-dimensional model may be needed to perform a comprehensive analysis of streambank stability for the composite streambanks in the Ozark Highlands ecoregion. Additional research is needed on the use of the internal angle of friction as a lumped calibration parameter for cohesionless soils. However, with the proper calibration and caution, CONCEPTS is a useful tool to guide the design and prioritization of streambank stabilization projects. C2 - 2013/// CY - Kansas City, Missouri DA - 2013/// PY - 2013/7/21/ DO - 10.13031/aim.20131620552 M1 - 131620552 PB - American Society of Agricultural and Biological Engineers UR - http://dx.doi.org/10.13031/aim.20131620552 ER - TY - JOUR TI - Special Section on Interconnection of Atmospheric Water, Surface Water, and Groundwater AU - Sheng, Zhuping AU - Fox, Garey AU - Abudu, Shalamu T2 - Journal of Hydrologic Engineering AB - As the climate changes, conjunctive use and management of water resources, or integrated water resources management, has become critically important for water resource planners and managers. Climate variability has resulted in irregular precipitation and temperature patterns, and, in turn, extreme storm events causing floods and frequent droughts. Such extreme events have raised stakeholders’ concerns for water availability. Conjunctive uses of multiple water resources are best management practices/ strategies to address this change in water availability. To implement such strategies, an important aspect gaining a better understanding of the hydrological interconnections among atmospheric water, surface water, and groundwater (three waters) as well as their trends or patterns with climate variations. The Earth’s hydrologic cycle is defined as “the pathway of water as it moves in its various phase through the atmosphere, to the Earth, over and through the land, to the ocean, and back to the atmosphere” (National Research Council 1991). Water in this hydrologic cycle (Chow et al. 1988) may be divided into atmospheric water, surface water, and groundwater (subsurface water). Surface water and atmospheric water transfer to each other through water surface evaporation, evapotranspiration by aquatic plants, and precipitation; groundwater and atmospheric water transfer to each other through near-surface evaporation, evapotranspiration through plants, and deep percolation of precipitation. Surface water and groundwater transfer to each other through seepage when they are hydraulically connected or by infiltration when they are hydraulically disconnected. This three-water transfer has been recognized since the latter part of the seventeenth century (Todd and Mays 2005). The three-water interactions mainly occur on the water’s surface, the land’s surface, and in the vadose zone above the groundwater table, as well as in the hyporheic zone between surface water and groundwater. Along with this water transfer, bio-chemical, physical, and kinetic interactions occur between atmospheric water, surface water, and groundwater. The threewater interactions involve multiple disciplines such as meteorology, surface hydrology, subsurface hydrology, geology, agronomy, pedology, and bio-ecology, to name just a few. Significant advances in understanding three-water interactions have been made over the last several decades. For example, advances in interactions between groundwater and surface water have been overviewed (Winter 1995, 1999; Sophocleous 2002; Diiwu 2003) since the growth in research related to surface-subsurface exchange processes mushroomed during the 1990s (Stanley and Jones 2000). Winter (1995) reviewed advances in understanding the interaction of groundwater and surface water in different landscapes: mountain, riverine, coastal, hummocky, and karst terrains. Winter (1999) proposed three general theoretical considerations regarding the interaction of groundwater with surface water. This interaction is affected by (1) different-scale groundwater flow systems, (2) local soil and geologic controls on seepage distribution, and (3) the magnitude of transpiration directly from groundwater around a surface-water perimeter since this transpiration intercepts potential groundwater inflows or draws water from surface-water bodies. Sophocleous (2002) synthesized and exemplified the interactions between groundwater and surface water in relation to climate, landform, geology, and biotic factors. Diiwu (2003) reviewed fundamental concepts of the ecohydrology of the interaction between groundwater and surface water, and discussed the relevance of this interaction to the sustainable management of water resources in semi-arid regions. A task committee (see subsequent information) was established within the Groundwater Council to promote scientific exchange and share experiences by inviting scientists and researchers to prepare articles and presentations focusing on the state of science relative to the interaction of atmospheric water, surface water, and groundwater, and on the impacts of climate change on water resources, as well as their conjunctive management and uses. This special section includes a collection of invited and peer-reviewed papers including field investigations, numerical simulations, and practical case studies on the following topics: physical/hydrological characterization of interactions; analytical and numerical models for simulating interactions; conjunctive uses and management of the three waters; climate change impacts on interaction of the three waters, including extreme events such as floods and drought; and water quality issues related to such interactions. In this special section, authors present their recent research findings on the interactions of the three waters and their associated processes. It is anticipated that this collection will promote further scientific exchange and further advances of our knowledge in this research area. We are very appreciative of the authors’ contribution and efforts and of the constructive comments and timely reports by reviewers and editors. DA - 2013/10// PY - 2013/10// DO - 10.1061/(asce)he.1943-5584.0000880 VL - 18 IS - 10 SP - 1191-1192 J2 - J. Hydrol. Eng. LA - en OP - SN - 1084-0699 1943-5584 UR - http://dx.doi.org/10.1061/(asce)he.1943-5584.0000880 DB - Crossref ER - TY - JOUR TI - Divergence and flow direction as indicators of subsurface heterogeneity and stage-dependent storage in alluvial floodplains AU - Heeren, D. M. AU - Fox, G. A. AU - Fox, A. K. AU - Storm, D. E. AU - Miller, R. B. AU - Mittelstet, A. R. T2 - Hydrological Processes AB - Assuming homogeneity in alluvial aquifers is convenient, but limits our ability to accurately predict stream-aquifer interactions. Research is needed on (i) identifying the presence of focused, as opposed to diffuse, groundwater discharge/recharge to streams and (ii) the magnitude and role of large-scale bank and transient storage in alluvial floodplains relative to changes in stream stage. The objective of this research was to document and quantify the effect of stage-dependent aquifer heterogeneity and bank storage relative to changes in stream stage using groundwater flow divergence and direction. Monitoring was performed in alluvial floodplains adjacent to the Barren Fork Creek and Honey Creek in northeastern Oklahoma. Based on results from subsurface electrical resistivity mapping, observation wells were installed in high and low electrical resistivity subsoils. Water levels in the wells were recorded real time using pressure transducers (August to October 2009). Divergence was used to quantify heterogeneity (i.e. variation in hydraulic conductivity, porosity, and/or aquifer thickness), and flow direction was used to assess the potential for large-scale (100 m) bank or transient storage. Areas of localized heterogeneity appeared to act as divergence zones allowing stream water to quickly enter the groundwater system, or as flow convergence zones draining a large groundwater area. Maximum divergence or convergence occurred with maximum rates of change in flow rates or stream stage. Flow directions in the groundwater changed considerably between base and high flows, suggesting that the floodplains acted as large-scale bank storage zones, rapidly storing and releasing water during passage of a storm hydrograph. During storm events at both sites, the average groundwater direction changed by at least 90° from the average groundwater direction during baseflow. Aquifer heterogeneity in floodplains yields hyporheic flows that are more responsive and spatially and temporally complex than would be expected compared to more common assumptions of homogeneity. Copyright © 2012 John Wiley & Sons, Ltd. DA - 2013/1/4/ PY - 2013/1/4/ DO - 10.1002/hyp.9674 VL - 28 IS - 3 SP - 1307-1317 J2 - Hydrol. Process. LA - en OP - SN - 0885-6087 UR - http://dx.doi.org/10.1002/hyp.9674 DB - Crossref KW - alluvial floodplains KW - direction KW - divergence KW - groundwater flow KW - heterogeneity KW - hydraulic gradient ER - TY - JOUR TI - Bank undercutting and tension failure by groundwater seepage: predicting failure mechanisms AU - Fox, Garey A. AU - Felice, Rachel G. T2 - Earth Surface Processes and Landforms AB - ABSTRACT Groundwater seepage can lead to the erosion and failure of streambanks and hillslopes. Two groundwater instability mechanisms include (i) tension failure due to the seepage force exceeding the soil shear strength or (ii) undercutting by seepage erosion and eventual mass failure. Previous research on these mechanisms has been limited to non‐cohesive and low cohesion soils. This study utilized a constant‐head, seepage soil box packed with more cohesive (6% and 15% clay) sandy loam soils at prescribed bulk densities (1.30 to 1.70 Mg m −3 ) and with a bank angle of 90° to investigate the controls on failure mechanisms due to seepage forces. A dimensionless seepage mechanism (SM) number was derived and evaluated based on the ratio of resistive cohesion forces to the driving forces leading to instability including seepage gradients with an assumed steady‐state seepage angle. Tension failures and undercutting were both observed dependent primarily on the saturated hydraulic conductivity, effective cohesion, and seepage gradient. Also, shapes of seepage undercuts for these more cohesive soils were wider and less deep compared to undercuts in sand and loamy sand soils. Direct shear tests were used to quantify the geotechnical properties of the soils packed at the various bulk densities. The SM number reasonably predicted the seepage failure mechanism (tension failure versus undercutting) based on the geotechnical properties and assumed steady‐state seepage gradients of the physical‐scale laboratory experiments, with some uncertainty due to measurement of geotechnical parameters, assumed seepage gradient direction, and the expected width of the failure block. It is hypothesized that the SM number can be used to evaluate seepage failure mechanisms when a streambank or hillslope experiences steady‐state seepage forces. When prevalent, seepage gradient forces should be considered when analyzing bank stability, and therefore should be incorporated into commonly used stability models. Copyright © 2013 John Wiley & Sons, Ltd. DA - 2013/10/17/ PY - 2013/10/17/ DO - 10.1002/esp.3481 VL - 39 IS - 6 SP - 758-765 J2 - Earth Surf. Process. Landforms LA - en OP - SN - 0197-9337 UR - http://dx.doi.org/10.1002/esp.3481 DB - Crossref KW - factor of safety KW - undercutting KW - bank failure KW - seepage KW - streambank stability KW - pore-water pressure ER - TY - CHAP TI - Effects of climate change on fisheries and aquaculture in the Southeast USA AU - Anderson, J.A. AU - Baker, S.M. AU - Graham, G.L. AU - Haby, M.G. AU - Hall, S.G. AU - Swann, L. AU - Walton, W.C. AU - Wilson, C.A. T2 - Climate of the Southeast United States: Variability, Change, Impacts, and Vulnerability PY - 2013/// DO - 10.5822/978-1-61091-509-0_9 SP - 190-209 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85025151905&partnerID=MN8TOARS ER - TY - JOUR TI - Cost analysis for high-volume and long-haul transportation of densified biomass feedstock AU - Gonzales, Daniela AU - Searcy, Erin M. AU - Ekşioğlu, Sandra D. T2 - Transportation Research Part A: Policy and Practice AB - Using densified biomass to produce biofuels has the potential to reduce the cost of delivering biomass to biorefineries. Densified biomass has physical properties similar to grain, and therefore, the transportation system in support of delivering densified biomass to a biorenery is expected to emulate the current grain transportation system. By analyzing transportation costs for products like grain and woodchips, this paper identifies the main factors that impact the delivery cost of densified biomass and quantifies those factors’ impact on transportation costs. This paper provides a transportation-cost analysis which will aid the design and management of biofuel supply chains. This evaluation is very important because the expensive logistics and transportation costs are one of the major barriers slowing development in this industry. Regression analysis indicates that transportation costs for densified biomass will be impacted by transportation distance, volume shipped, transportation mode used, and shipment destination, just to name a few. Since biomass production is concentrated in the Midwestern United States, a biorefinery’s shipments will probably come from that region. For shipments from the Midwest to the Southeast US, barge transportation, if available, is the least expensive transportation mode. If barge is not available, then unit trains are the least expensive mode for distances longer than 161 km (100 miles). For shipments from the Midwest to the West US, unit trains are the least expensive transportation mode for distances over 338 km (210 miles). For shorter distances, truck is the least expensive transportation mode for densified biomass. DA - 2013/3// PY - 2013/3// DO - 10.1016/j.tra.2013.01.005 VL - 49 SP - 48-61 J2 - Transportation Research Part A: Policy and Practice LA - en OP - SN - 0965-8564 UR - http://dx.doi.org/10.1016/j.tra.2013.01.005 DB - Crossref KW - Densified biomass KW - Barge transportation KW - Rail transportation KW - Truck transportation KW - Regression analysis ER - TY - JOUR TI - Genome Sequence of the Autotrophic Acetogen Clostridium autoethanogenum JA1-1 Strain DSM 10061, a Producer of Ethanol from Carbon Monoxide AU - Bruno-Barcena, J. M. AU - Chinn, M. S. AU - Grunden, A. M. T2 - Genome Announcements AB - ABSTRACT Clostridium autoethanogenum is an anaerobic, autotrophic acetogen that is capable of converting CO and CO 2 into ethanol and acetate. Here we report the draft genome sequence of C. autoethanogenum JA1-1 strain DSM 10061 (4.5 Mbp; G+C content, 37.5%) and the findings obtained from annotation of the genome sequence. DA - 2013/8/15/ PY - 2013/8/15/ DO - 10.1128/genomeA.00628-13 VL - 1 IS - 4 J2 - Genome Announcements LA - en OP - SN - 2169-8287 UR - http://dx.doi.org/10.1128/genomeA.00628-13 DB - Crossref ER - TY - JOUR TI - Development of a Mechanical Undercutting System to Minimize Sweetpotato Skinning during Harvest AU - Hayes, Bradley H. AU - Ward, Jason K. AU - Lowe, John W. AU - Davis, Jeremiah D. AU - Shankle, Mark W. AU - Arancibia, Ramon A. T2 - 2013 Kansas City, Missouri, July 21 - July 24, 2013 AB - Abstract. Sweetpotatoes have been an important high-value crop in Mississippi and future growth is expected. Industry growth has created the need for a continuous supply of sweetpotatoes throughout the year. Therefore, managing the harvest process and postharvest storage environment is critical to maintaining a year-round supply of quality sweetpotato roots. This has been a challenge in Mississippi and growers have been experiencing post-harvest losses due to excessive root shrinkage (weight loss) and bacterial and fungal rots. Studies indicate that 20% to 25% of sweetpotatoes are lost to moisture loss and decay during postharvest storage. This is directly related to skinning at harvest procedures that cause cuts and abrasions (skinning) to the delicate skin of the sweetpotato root is. These wounds provide a way-of-entry for diseases to infect the root, as well as moisture loss that results in root shrinkage. De-vining sweetpotatoes prior to harvest is a commonly used method to halt root growth and to begin toughening the skin. This method is viable for producers using manually-assisted harvesting for the fresh market. Producers using bulk harvesting prefer to leave vines on to reduce the amount of foreign material going into storage. A new method of halting plant growth and allowing the root to cure in the ground prior to harvest is needed. The objective of this study was to design and test a mechanical root pruning blade to halt plant growth and initiate skin set prior to harvest of sweetpotatoes and to quantify the effects of undercutting sweetpotatoes on skin strength relative to de-vining. It was hypothesized that cutting the deep root of the sweetpotato plant would allow this process to begin. Therefore, two different undercutting implements were designed and fabricated. One was assembled from currently available off-the-shelf components and the other was a modified commercially available sweetpotato digger. These implements were tested in experimental plots and the skin strength was directly measured. Root skin strength was measured at three days and six days after treatment. There was a significant rainfall event on the fifth day after treatment, meaning that no comparison between the time periods can be made. One of the tested varieties responded to undercutting. Results indicated that at three days after treatment, undercutting had no significant effect on skin strength for both vine conditions (vine-on and de-vined). At six days after treatment, undercutting with the newly developed implement significantly increased skin strength for roots in which the vine had been left on. There was no difference between using the modified digger and no treatment. Additionally, there was no treatment effect on roots which were de-vined. These results indicate that in a bulk harvesting system, undercutting with the new implement will increase skin strength after the roots have cured in the ground. DA - 2013/// PY - 2013/// DO - 10.13031/aim.20131596108 ER - TY - JOUR TI - Seepage-Induced Streambank Erosion and Instability: In Situ Constant-Head Experiments AU - Midgley, T. L. AU - Fox, G. A. AU - Wilson, G. V. AU - Heeren, D. M. AU - Langendoen, E. J. AU - Simon, A. T2 - Journal of Hydrologic Engineering AB - The effects of seepage on streambank erosion and failure are less understood compared to fluvial processes, especially the linkage between surface water and groundwater mechanisms. Field data are needed to validate laboratory seepage erosion and instability conclusions and to understand how engineering tools and methods may be applied to field conditions. An innovative trench injection system was utilized to provide a constant head on a near-streambank groundwater system when filled with stream water. This research was performed on a streambank of Dry Creek, a deeply incised stream with near-vertical banks located in Mississippi. Experiments included installing a trench (2.8 m from the bank and 2 m below ground surface) and a network of tensiometers and observation wells to measure soil-water pressures and water table elevations. Bank stratigraphy consisted of a sloping, conductive loamy sand layer between cohesive streambank layers. Groundwater conditions were monitored during a series of induced-seepage experiments. The bank face was outfitted with a seepage collection device to measure seep flow rates and sediment concentrations. Seepage flow rates (as high as 0.4 L/min) and corresponding erosion rates (as high as 0.86 kg/min) were proportional to estimated hydraulic gradients in the near-streambank region and followed an excess flow rate equation. However, flow paths and hydraulic gradients were largely nonuniform due to local variability in streambank stratigraphy, suggesting difficulty when attempting to apply engineering analyses of bank erosion and stability for seepage processes without accounting for this heterogeneity. Seepage flow and erosion became restricted when small-scale bank failures due to undercutting blocked flow pathways and limited particle mobilization, termed temporary self-healing. Seepage erosion was shown to be an important mechanism of streambank failure, especially when acting in concert with fluvial erosion processes that prevent permanent self-healing of seeps. DA - 2013/10// PY - 2013/10// DO - 10.1061/(ASCE)HE.1943-5584.0000685 VL - 18 IS - 10 SP - 1200-1210 J2 - J. Hydrol. Eng. LA - en OP - SN - 1084-0699 1943-5584 UR - http://dx.doi.org/10.1061/(ASCE)HE.1943-5584.0000685 DB - Crossref KW - Seepage KW - River bank erosion KW - Subsurface flow KW - Experimentation KW - Seepage erosion KW - Streambank erosion KW - Streambank failure KW - Streambank stability KW - Subsurface flow KW - Surface KW - groundwater interaction ER - TY - CONF TI - Sediment and phosphorus loading from protected and unprotected streambanks in Eastern Oklahoma AU - Miller, R. AU - Fox, G.A. AU - Penn, C.J. AU - Lovern, S. AU - Purvis, R. C2 - 2013/// C3 - American Society of Agricultural and Biological Engineers Annual International Meeting 2013, ASABE 2013 DA - 2013/// VL - 3 SP - 2584-2594 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84881631367&partnerID=MN8TOARS ER - TY - JOUR TI - Pore-water pressures associated with clogging of soil pipes: Numerical analysis of laboratory experiments AU - Wilson, G.V. AU - Fox, G.A. T2 - Soil Science Society of America Journal AB - Clogging of soil pipes due to excessive internal erosion has been hypothesized to cause extreme erosion events such as landslides, debris flows, and gullies, but confirmation of this phenomenon has been lacking. Laboratory and field measurements have failed to measure pore‐water pressures within pipes and models of pipe flow have not addressed internal erosion or pipe clogging. The objective of this study was to model laboratory experiments of pipe flow in which clogging was observed in order to understand the clogging process. Richards' equation was used to model pipe flow, with the soil pipe represented as a highly conductive, low‐retention porous medium. The modeling used two contrasting boundary conditions, constant flux (CF) and constant head (CH), to quantify pressure buildups due to pipe clogging and differences in simulated pressures between the two imposed boundary conditions. Unique to these simulations was inclusion of pipe enlargement with time due to internal erosion, representation of partially full flow conditions, and inclusion of pipe clogging. Both CF and CH boundary conditions confirmed the concept of pressure buildup as a result of pipe clogging. Pressure jumps of around 54 m for CF and 18 cm for CH occurred in <0.1 s, while soil water pressures 4 cm radially outward from the pipe had not responded. These findings demonstrate the need to measure pressures within soil pipes due to hydraulic nonequilibrium between the pipe and soil matrix. Pore water pressures within the pipe below the clog rapidly (<0.25 s) drained to unsaturated conditions, indicating the ability of soil pipes to drain hillslopes and rapidly recover when clogs are flushed from the soil pipe. These dynamic processes need to be incorporated into stability models to properly model hillslope processes. DA - 2013/// PY - 2013/// DO - 10.2136/sssaj2012.0416 VL - 77 IS - 4 SP - 1168-1181 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84880722808&partnerID=MN8TOARS ER - TY - CONF TI - Quantifying the Erodibility and Geotechnical Strength of Cohesive Alluvial Soils Following Streambank Reconstruction AU - Lovern, S. B. AU - Fox, G. A. AU - Miller, R. B. T2 - World Environmental and Water Resources Congress 2013 AB - Post-construction data following streambank restoration and stabilization projects are currently lacking relative to the resistance of cohesive streambanks to geotechnical failure and fluvial erosion. This research sought to quantify differences in erodibility and geotechnical properties of natural and restored banks after construction. The streambank environments varied with respect to the presence or type of construction and resulting bank slopes. Streambank conditions included modified fill bank plots, modified cut bank plots, and nonmodified control bank plots. Geotechnical resistance to failure was quantified using the Iowa borehole shear test (BST) to measure the in-situ drained shear strength of soils. Fluvial resistance to erosion was measured using an in-situ "mini" jet erosion test ("mini" JET) to estimate the erodibility coefficient and critical shear stress. Bulk densities were affected by construction activities with a general trend toward higher bulk densities with greater construction modification. Geotechnical strength, in terms of the soil's effective cohesion for the modified fill bank plots, differed between the modified cut bank plots and the nonmodified control plots but additional samples are needed for statistical relevance. Surprisingly, fluvial resistance to erosion may not be influenced by streambank modification based on "mini" JETs conducted to date. Variability in fluvial resistance parameters within each treatment was as large as differences between treatments. These modifications to the streambank fluvial and geotechnical resistance properties should be considered when modeling the impact of stabilization practices on streambanks. C2 - 2013/5/28/ C3 - World Environmental and Water Resources Congress 2013 DA - 2013/5/28/ DO - 10.1061/9780784412947.196 SP - 2000-2008 PB - American Society of Civil Engineers SN - 9780784412947 UR - http://dx.doi.org/10.1061/9780784412947.196 DB - Crossref ER - TY - CONF TI - Modified excess shear stress model parameters based on mechanistic predictions from a detachment rate model AU - Al-Madhhachi, A.-S.T. AU - Fox, G.A. C2 - 2013/// C3 - American Society of Agricultural and Biological Engineers Annual International Meeting 2013, ASABE 2013 DA - 2013/// VL - 3 SP - 2565-2583 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84881650740&partnerID=MN8TOARS ER - TY - JOUR TI - Sediment and Phosphorus Loading from Protected and Unprotected Streambanks in Eastern Oklahoma AU - Fox, Garey A AU - Miller, Ronald B AU - Lovern, Sharla AU - Purvis, Rebecca AU - Penn, Chad J T2 - 2013 Kansas City, Missouri, July 21 - July 24, 2013 AB - Abstract. Nutrients and excessive sediment are two main nonpoint source pollutants in the United States. In some watersheds, the majority of the total sediment load to streams and rivers is from streambank erosion. The presence of riparian vegetation can significantly decrease streambank erosion in some locations. Streambank erosion and failure may be one pathway for phosphorus (P) loading to streams, but insufficient data exists on actual loading from this source and the potential protective effect of riparian vegetation in most watersheds. The objective of this research was to characterize the distribution of soil phosphorus concentrations in streambanks both with and without implemented riparian protection in the Barren Fork Creek watershed in eastern Oklahoma and to estimate P loading due to bank erosion. Barren Fork Creek is a state-designated Scenic River in Oklahoma where soil phosphorus (P) levels are potentially high due to historic poultry litter application. Streambank soil samples were collected at three transects and at four vertical locations at six different reaches. The core samples were collected up to 50 cm into the bank at each location, and were analyzed for water-soluble phosphorus (WSP), pH, and electrical conductivity (EC). Contour plots of streambank phosphorus concentrations illustrated considerable differences among reaches relative to adjacent land use. Lateral bank erosion over a seven year period (2003-2010) was estimated using NAIP aerial imagery. Average streambank migration rates were approximately 8 m for the three sites with riparian protection compared to 45 m for the three sites without riparian protection over the seven year period. A helicopter video reconnaissance of the Barren Fork Creek watershed in Oklahoma estimated the percent of the banks that were failing to be approximately 38% of the total length (considering left and right banks). Consequently, streambank erosion represents a significant source of phosphorus entering Barren Fork Creek and eventually impacting water supply reservoirs. Total water soluble phosphorus from streambanks on the Barren Fork Creek from unprotected and failing banks is approximately 1540 kg per year, which represents approximately 10% of the estimated total dissolved phosphorus load. DA - 2013/// PY - 2013/// DO - 10.13031/aim.20131596591 ER - TY - JOUR TI - Measuring soil erodibility using a laboratory "mini" jet AU - Al-Madhhachi, A.T. AU - Hanson, G.J. AU - Fox, G.A. AU - Tyagi, A.K. AU - Bulut, R. T2 - Transactions of the ASABE AB - <italic>Abstract.</italic> Typically soil erodibility is quantified using an excess shear stress equation, dependent on two major soil parameters: the critical shear stress (τc) and the erodibility coefficient (kd). A submerged jet test (JET, Jet Erosion Test) is one method that has been developed and methodology of use established in the literature for measuring these parameters. In this study, a new miniature version of the JET device (“mini” JET), with the advantage of being easier to use in the field, was used to measure τc and kd for two soils (silty sand and clayey sand), and results were compared to the larger original laboratory JET. The objective of this research was to determine if the “mini” JET measured equivalent values for τc and kd compared to the original JET device. In-order to compare the performance and repeatability of both JET devices, tests were performed on paired samples prepared in the same way and tested at the same time. Samples of the soils tested were prepared at different water contents with a standard compaction effort of 600 kN-m/m3 (ASTM). Some variability in measuring τc and kd was observed between paired samples due to variability in the soil texture of the soil samples and differences in soil moisture levels. The kd values measured by the two JET devices for both soils were not significantly different. The τc values measured by the “mini” JET were consistently lower than those measured by the original JET. This was hypothesized to be due to the structure of the soil sample due to the compaction method and the procedure utilized to determine τc. Adjustment of the equilibrium depth of the “mini” JET resulted in small differences in the estimated τc between both JET devices. Both JET devices also demonstrated consistent performance in measuring τc-kd relationships, which were compared with those observed in previous field research. DA - 2013/// PY - 2013/// DO - 10.13031/trans.56.9742 VL - 56 IS - 3 SP - 901-910 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84884175110&partnerID=MN8TOARS ER - TY - JOUR TI - Formation of Manganese Oxide Coatings onto Sand for Adsorption of Trace Metals from Groundwater AU - Tilak, A. S. AU - Ojewole, S. AU - Williford, C. W. AU - Fox, G. A. AU - Sobecki, T. M. AU - Larson, S. L. T2 - Journal of Environmental Quality AB - Manganese oxide (MnOx(s)) occurs naturally in soil and has a high affinity for trace metals adsorption. In this work, we quantified the factors (pH; flow rate; use of oxidants such as bleach, H2O2, and O3; initial Mn(II) concentrations; and two types of geologic media) affecting MnOx(s) coatings onto Ottawa and aquifer sand using batch and column experiments. The batch experiments consisted of manual and automated titration, and the column experiments mimicked natural MnOx(s) adsorption and oxidation cycles as a strategy for in situ adsorption. A Pb solution of 50 mg L−1 was passed through MnOx(s)–coated sand at a flow rate of 4 mL min−1 to determine its adsorption capacity. Batch experimental results showed that MnOx(s) coatings increased from pH 6 to 8, with maximum MnOx(s) coating occurring at pH 8. Regarding MnOx(s) coatings, bleach and O3 were highly effective compared with H2O2. The Ottawa sand had approximately twice the MnOx(s) coating of aquifer sand. The sequential increase in initial Mn(II) concentrations on both sands resulted in incremental buildup of MnOx(s). The automated procedure enhanced MnOx(s) coatings by 3.5 times compared with manual batch experiments. Column results showed that MnOx(s) coatings were highly dependent on initial Mn(II) and oxidant concentrations, pH, flow rate, number of cycles (h), and the type of geologic media used. Manganese oxide coating exceeded 1700 mg kg−1 for Ottawa sand and 130 mg kg−1 for aquifer sand. The Pb adsorption exceeded 2200 mg kg−1 for the Ottawa sand and 300 mg kg−1 for the aquifer sand. DA - 2013/11// PY - 2013/11// DO - 10.2134/jeq2013.04.0142 VL - 42 IS - 6 SP - 1743-1751 J2 - J. Environ. Qual. LA - en OP - SN - 0047-2425 UR - http://dx.doi.org/10.2134/jeq2013.04.0142 DB - Crossref ER - TY - JOUR TI - In situ soil pipeflow experiments on contrasting streambank soils AU - Midgley, T.L. AU - Fox, G.A. AU - Wilson, G.V. AU - Felice, R.M. AU - Heeren, D.M. T2 - Transactions of the ASABE DA - 2013/// PY - 2013/// VL - 56 IS - 2 SP - 479-488 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84878571859&partnerID=MN8TOARS ER - TY - CONF TI - Impact of measurement scale on infiltration and phosphorus leaching in Ozark floodplains AU - Heeren, D.M. AU - Fox, G.A. AU - Storm, D.E. AU - Haggard, B.E. AU - Penn, C.J. AU - Halihan, T. C2 - 2013/// C3 - American Society of Agricultural and Biological Engineers Annual International Meeting 2013, ASABE 2013 DA - 2013/// VL - 6 SP - 4991-5006 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84881628532&partnerID=MN8TOARS ER - TY - JOUR TI - Impact of Measurement Scale on Infiltration and Phosphorus Leaching in Ozark Floodplains AU - Heeren, Derek M. AU - Fox, Garey A. AU - Storm, Daniel E. AU - Haggard, Brian E. AU - Penn, Chad J. AU - Halihan, Todd T2 - 2013 Kansas City, Missouri, July 21 - July 24, 2013 AB - Abstract. Increased nutrient loads have resulted in several adverse impacts on surface water quality, including excessive algal growth, fish kills, and drinking water taste and odor issues across the United States and especially in the Ozark ecoregion of northeastern Oklahoma and northwestern Arkansas. The significance of this problem has been highlighted by litigation, with one case even reaching the U.S. Supreme Court (Arkansas et al. v. Oklahoma et al., 503 U.S. 91) which required the upstream state to meet downstream water quality standards. The overarching objective of this line of research was to characterize phosphorus leaching to alluvial aquifers in the coarse gravel floodplains of the Ozark ecoregion, while the specific objective of this paper was to quantify infiltration and hydraulic conductivity across a range of scales (point to 100 m2) to evaluate the effect of the scale of measurement. It is hypothesized that hydrologic heterogeneities (e.g., macropores and gravel outcrops) in the subsurface play an integral role in impacting flow and contaminant transport between the soil surface and alluvial aquifers. Innovative field studies, including plot scale injection experiments, were performed across a range of soil types at each of three floodplain sites in the Ozark ecoregion. Solutes in the injection water included phosphorus, P (highly sorptive), Rhodamine WT (slightly sorptive), and chloride (conservative). Plots maintained a constant head of 2 to 9 cm for up to 52 hours. Effective saturated hydraulic conductivity (Keff) data, based on plot scale infiltration rates, were high (0.6 to 68 cm hr-1) and varied greatly, even within a single floodplain. The Keff was also measured with a double ring infiltrometer and estimated at the point scale using Retention Curve (RETC) along with particle size distribution data. Point scale estimates were significantly lower than plot scale Keff, and also failed to capture the variability of Keff within a field site. The estimated permeability of the limiting layer reported by the U.S. Natural Resources Conservation Service (NRCS) Soil Survey was consistent with point scale estimates of Keff, but was lower than plot scale Keff at most sites. Plot scale infiltration tests are recommended over double ring infiltrometer tests or point scale estimates, although only small plots (1 m by 1 m) are necessary. DA - 2013/// PY - 2013/// DO - 10.13031/aim.20131621213 ER - TY - CONF TI - Flume experiments to determine the erodibility of gravel streambank soils AU - Criswell, D.T. AU - Fox, G.A. AU - Al-Madhhachi, A.-S.T. AU - Miller, R. AU - Daly, E. C2 - 2013/// C3 - American Society of Agricultural and Biological Engineers Annual International Meeting 2013, ASABE 2013 DA - 2013/// VL - 6 SP - 4913-4923 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84881625740&partnerID=MN8TOARS ER - TY - JOUR TI - Modified Excess Shear Stress Model Parameters based on Mechanistic Predictions from a Detachment Rate Model AU - Al-Madhhachi, Abdul-Sahib T AU - Fox, Garey A T2 - 2013 Kansas City, Missouri, July 21 - July 24, 2013 AB - Abstract. The excess shear stress approach is commonly used to quantify the erosion rate of cohesive soils due to fluvial forces, dependent on two major soil parameters: the critical shear stress (τc) and the erodibility coefficient (kd). The excess shear stress equation is commonly used in streambank, hillslope, and runoff models. However, mechanistic approaches are currently unavailable for incorporating multiple forces, such as localized groundwater seepage, into these parameters. A more mechanistically-based detachment model, the “Modified Wilson Model,” was recently developed based on two soil parameters (b0 and b1) for modeling the erosion rate of soils using the hydraulic analysis of an open channel or a jet erosion test (JET). The objective of this study was to mathematically derive relationships for modifying the excess shear stress parameters (τc and kd) based on parameter predictions by the mechanistic detachment rate model (b0 and b1). Therefore, a more mechanistic determination of erodibility parameters can be achieved without altering the structure of many sediment transport models constructed on the basis of the excess shear stress approach. Expressions for the modified τc and kd were based on equating two detachment rate models and assuming that the power term in the excess shear stress equation was 0.5. Data from previous laboratory and in-situ JET devices and flume tests performed on two cohesive soils (silty sand and clayey sand) for a case with a single force (fluvial only) and a case with multiple forces (fluvial and seepage) were utilized to derive the original excess stress model parameters along with the modified τc and kd parameters. The modified parameters in the excess shear stress equation allowed improved predictions of the observed data for both the flume tests and JETs. DA - 2013/// PY - 2013/// DO - 10.13031/aim.20131596581 ER - TY - JOUR TI - Internal Erosion during Soil Pipeflow: State of the Science for Experimental and Numerical Analysis AU - Wilson, Glenn V. AU - Nieber, John L. AU - Sidle, Roy C. AU - Fox, Garey A. T2 - Transactions of the ASABE AB - Keywords: Ephemeral gully erosion Erodibility Internal erosion Landslides Pipeflow Soil pipes. Abstract. Many field observations have led to speculation on the role of piping in embankment failures, landslides, and gully erosion. However, there has not been a consensus on the subsurface flow and erosion processes involved, and inconsistent use of terms have exacerbated the problem. One such piping process that has been the focus in numerous field observations, but with very limited mechanistic experimental work, is flow through a discrete macropore or soil pipe. Questions exist as to the conditions under which preferential flow through soil pipes results in internal erosion, stabilizes hillslopes by acting as drains, destabilizes hillslopes via pore-pressure buildups, and results in gully formation or reformation of filled-in ephemeral gullies. The objectives of this article are to review discrepancies in terminology in order to represent the piping processes better, to highlight past experimental work on the specific processes of soil pipeflow and internal erosion, and to assess the state-of-the-art modeling of pipeflow and internal erosion. The studies reviewed include those that examined the process of slope stability as affected by the clogging of soil pipes, the process of gullies forming due to mass failures caused by flow into discontinuous soil pipes, and the process of gully initiation by tunnel collapse due to pipes enlarging by internal erosion. In some of these studies, the soil pipes were simulated with perforated tubes placed in the soil, while in others the soil pipes were formed from the soil itself. Analytical solutions of the excess shear stress equation have been applied to experimental data of internal erosion of soil pipes to calculate critical shear stress and erodibility properties of soils. The most common numerical models for pipeflow have been based on Richards’ equation, with the soil pipe treated as a highly conductive porous medium instead of a void. Incorporating internal erosion into such models has proven complicated due to enlargement of the pipe with time, turbulent flow, and episodic clogging of soil pipes. These studies and modeling approaches are described, and gaps in our understanding of pipeflow and internal erosion processes and our ability to model these processes are identified, along with recommendations for future research. DA - 2013/// PY - 2013/// DO - 10.13031/2013.42667 VL - 56 IS - 2 SP - 465-478 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84878537147&partnerID=MN8TOARS ER - TY - JOUR TI - Flume Experiments to Determine the Erodibility of Gravel Streambank Soils AU - Criswell, David T AU - Fox, Garey A AU - Miller, Ron B AU - Daly, Erin AU - Al-Madhhachi, Abdul-Sahib T2 - 2013 Kansas City, Missouri, July 21 - July 24, 2013 AB - Abstract. Fluvial erosion in streambank stability models is typically modeled using an excess shear stress equation based on two soil parameters: the erodibility coefficient (kd) and critical shear stress (τc). For cohesive soils, methods exist such as jet erosion tests (JETs) for measuring kd and τc. For noncohesive bank materials such as sands and gravels, τc is commonly estimated using the Shields diagram based on the median particle diameter. However, no universally accepted relationship exists for estimating kd for noncohesive soils. Also, recent research has proposed the use of more fundamentally-based mechanistic detachment models in place of the excess shear stress equation, but limited research has been performed in deriving the parameters of these alternative detachment models. One such model investigated in this research is the Wilson Model, which is based on two parameters: b0 and b1. The objectives of this research included the following: (i) conduct flume experiments on noncohesive gravels to quantify detachment rates relative to the imposed shear stress, (ii) derive kd and τc and b0 and b1 for these gravels, (iii) determine if relationships can be developed relating kd versus τc and b0 versus b1, (iv) compare the kd-τc relationship to previously proposed relationships, and (v) compare the relative performance of the models in being able to fit the scour data. Flume experiments were conducted at the USDA-ARS Hydraulics Laboratory. Samples of gravels were extracted from streambanks on the Barren Fork Creek in eastern Oklahoma. The samples were sieved into particle size classes and then at least triplicate flume experiments were performed with average gravel sizes of 0.45, 0.60, 1.30, and 1.90 cm (0.18, 0.25, 0.50, and 0.75 inches, respectively). Scour depth was measured using a point gage during the flume experiment. The kd-τc relationships derived from the laboratory experiments followed a power law relationship with the form: kd=2.23τc-0.50 (R2 = 0.65). The Wilson Model parameters b0 and b1 derived from this research appeared to have a similar relationship but different magnitude than kd and τc. The kd-τc or b0-b1 relationships can be used to model fluvial erosion of the noncohesive gravel and therefore the resulting streambank failure of composite banks. DA - 2013/// PY - 2013/// DO - 10.13031/aim.20131620973 ER - TY - JOUR TI - Behavior of sandy slopes remediated by EPS-block geofoam under seepage flow AU - Akay, Onur AU - Özer, A. Tolga AU - Fox, Garey A. AU - Bartlett, Steven F. AU - Arellano, David T2 - Geotextiles and Geomembranes AB - Expanded polystyrene (EPS) geofoam (geofoam block) is commonly used as a lightweight fill for many civil engineering applications. However, when used for slope remediation, the behavior of geofoam block for slope systems undergoing seepage flow is not well known. In this study, a total of 36 laboratory lysimeter experiments (dimensions of 60 cm height, 20 cm width, and 200 cm length) were conducted to investigate the behavior of sandy slopes containing geofoam blocks as a lightweight fill material. These experiments were conducted with three different values of constant water pressure in the water reservoir located at one end of the lysimeter. In addition, three different configurations of geofoam block were tested with geofoam blocks placed on the face of the packed sandy slope. The dimensions of the geofoam blocks were 2.5 cm high, 5 cm wide, and 15 cm long to achieve a 1:20 scale corresponding to actual block size that is commonly manufactured. Laboratory physical test results were quantified by coupled seepage flow and slope stability models showing the adverse effect of seepage on the factor of safety (FS). Geofoam block configurations were found to be stable against seepage conditions which would cause a shallow-seated failure of the slope in the absence of the geofoam blocks. This is due to the fact that the geofoam blocks could completely fill the mass of the existing slope material subjected to failure. However, the geofoam block configurations were unstable against seepage conditions that resulted in deep-seated failures of marginally stable, sand slopes. DA - 2013/4// PY - 2013/4// DO - 10.1016/j.geotexmem.2013.02.005 VL - 37 SP - 81-98 J2 - Geotextiles and Geomembranes LA - en OP - SN - 0266-1144 UR - http://dx.doi.org/10.1016/j.geotexmem.2013.02.005 DB - Crossref KW - EPS-block geofoam KW - Slope stability KW - Seepage ER - TY - JOUR TI - Empirical model for quantifying total phosphorus reduction by vegetative filter strips AU - Fox, G.A. AU - Penn, C.J. T2 - Transactions of the ASABE DA - 2013/// PY - 2013/// DO - 10.13031/trans.56.100133 VL - 56 IS - 4 SP - 1461-1469 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84885461477&partnerID=MN8TOARS ER - TY - JOUR TI - Distinct influence of filter strips on acute and chronic pesticide aquatic environmental exposure assessments across U.S. EPA scenarios AU - Sabbagh, George J. AU - Muñoz-Carpena, Rafael AU - Fox, Garey A. T2 - Chemosphere AB - Vegetative filter strips (VFS) are proposed for protection of receiving water bodies and aquatic organisms from pesticides in runoff, but there is debate regarding the efficiency and filter size requirements. This debate is largely due to the belief that no quantitative methodology exists for predicting runoff buffer efficiency when conducting acute and/or chronic environmental exposure assessments. Previous research has proposed a modeling approach that links the U.S. Environmental Protection Agency's (EPA's) PRZM/EXAMS with a well-tested process-based model for VFS (VFSMOD). In this research, we apply the modeling framework to determine (1) the most important input factors for quantifying mass reductions of pesticides by VFS in aquatic exposure assessments relative to three distinct U.S. EPA scenarios encompassing a wide range of conditions; (2) the expected range in percent reductions in acute and chronic estimated environmental concentrations (EECs); and (3) the differential influence of VFS when conducting acute versus chronic exposure assessments. This research utilized three, 30-yr U.S. EPA scenarios: Illinois corn, California tomato, and Oregon wheat. A global sensitivity analysis (GSA) method identified the most important input factors based on discrete uniform probability distributions for five input factors: VFS length (VL), organic-carbon sorption coefficient (K(oc)), half-lives in both water and soil phases, and application timing. For percent reductions in acute and chronic EECs, VL and application timing were consistently the most important input factors independent of EPA scenario. The potential ranges in acute and chronic EECs varied as a function of EPA scenario and application timing. Reductions in acute EECs were typically less than percent reductions in chronic EECs because acute exposure was driven primarily by large individual rainfall and runon events. Importantly, generic specification of VFS design characteristics equal across scenarios should be avoided. The revised pesticide assessment modeling framework offers the ability to elucidate the complex and non-linear relationships that can inform targeted VFS design specifications. DA - 2013/1// PY - 2013/1// DO - 10.1016/j.chemosphere.2012.06.034 VL - 90 IS - 2 SP - 195-202 J2 - Chemosphere LA - en OP - SN - 0045-6535 UR - http://dx.doi.org/10.1016/j.chemosphere.2012.06.034 DB - Crossref KW - Exposure assessment KW - Pesticides KW - Sensitivity analysis KW - Vegetative filter strips KW - VFSMOD ER - TY - CONF TI - Application of isothermal calorimetry to the study of phosphorus sorption onto soils in a flow-through system AU - Penn, C.J. AU - Hereen, D.M. AU - Fox, G.A. C2 - 2013/// C3 - American Society of Agricultural and Biological Engineers Annual International Meeting 2013, ASABE 2013 DA - 2013/// VL - 6 SP - 4963-4976 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84881624253&partnerID=MN8TOARS ER - TY - CONF TI - Finite element modeling of phosphorus leaching through floodplain soils dominated by preferential flow pathways AU - Freiberger, R.P. AU - Heeren, D.M. AU - Fox, G.A. C2 - 2013/// C3 - American Society of Agricultural and Biological Engineers Annual International Meeting 2013, ASABE 2013 DA - 2013/// VL - 1 SP - 340-348 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84881642124&partnerID=MN8TOARS ER - TY - JOUR TI - Finite element modeling of phosphorus leaching through floodplain soils dominated by preferential flow pathways AU - Freiberger, Ryan P AU - Heeren, Derek M. AU - Fox, Garey A. T2 - 2013 Kansas City, Missouri, July 21 - July 24, 2013 AB - Abstract. Phosphorus is a critical nutrient in soils, providing both positive and negative effects to different systems. While optimum crop growth requires a range of P above 0.2 mg/L, preventing surface water enrichment generally requires P to be below 0.03 mg/L. Proper application and control of phosphorus is important to increase farming efficiency and to protect freshwater systems from toxic algal growth. While the movement of phosphorus through many soil types has been well-documented, the presence of highly conductive, gravel outcrops and macropores in soil can have a significant, poorly-documented effect on phosphorus movement. In the Ozark ecoregion, for example, the erosion of carbonate bedrock (primarily limestone) by slightly acidic water has left a large residuum of chert gravel in Ozark soils, with floodplains generally consisting of coarse chert gravel overlain by a mantle (1 to 300 cm) of gravelly loam or silt loam. Highly conductive gravel outcrops and macropores may create preferential flow pathways for water moving through the soil column, along with any solutes in solution. In previous research, floodplain sites in Oklahoma and Arkansas were chosen due to the presence of cherty gravel outcrops that reached near the soil surface. Soil properties were evaluated, and two-dimensional electrical resistivity data were collected and correlated to hydraulic conductivity. Water was then applied to several plots (1, 10, and 100 m2) with known concentrations of phosphorus, Rhodamine WT, and chloride for up to 52 hours, and flow towards a nearby stream was monitored with observation wells. The objective of this research was to use finite element modeling to develop a long-term model for this phenomenon for future predictions. Results from the previous research were modeled with HYDRUS-3D, a three-dimensional, finite-element model for flow and contaminant transport (both equilibrium and physical/chemical nonequilibrium transport) through soils. HYDRUS-3D was setup to simulate the 1 m2 infiltration plot at the Barren Fork Creek site, with initial hydraulic conductivity data calculated from the plot scale infiltration experiment for the upper silt loam soil and from 2D geophysical data for the underlying gravel. The mobile-immobile (MIM) phase model within HYDRUS was also utilized, and MIM solute transport parameters were found iteratively using chloride tracer data taken from two wells. Results from this research will be used to predict phosphorus transport parameters and solve for long-term phosphorus transport through these soil profiles. DA - 2013/// PY - 2013/// DO - 10.13031/aim.20131583250 ER - TY - CONF TI - Application of isothermal calorimetry to the study of phosphorus sorption onto soils in a flow-through system AU - Penn, C.J. AU - Heeren, D.M. AU - Fox, G.A. T2 - 2013 ASABE Annual International Meeting AB - Abstract. The degree, mechanisms, and kinetics of phosphorus (P) sorption onto soils can have a significant influence on leaching losses of P from soil. The objectives of this study were to measure the impact of retention time (RT) on P sorption in a flow-through system intended to simulate downward movement of a P solution through two different riparian soils, and determine if isothermal titration calorimetry (ITC) can provide useful information reflective of flow-through results. Topsoil from two riparian/alluvial soils was sampled and characterized for P concentrations and parameters related to P sorption. Flow-through P sorption experiments were conducted in order to examine the effect of RT and inflow P concentration on P sorption; this was compared to results of ITC experiments where the heat of reaction was measured with the addition of P to soils. Results of ITC experiments were reflective of both soil characterization and flow-through sorption in that the Barren Fork soil sorbed less P, but at a faster rate, compared to Clear Creek. Based on thermograms, the dominant P sorption reaction was ligand exchange onto Al/Fe oxides/hydroxides, with a lesser degree of precipitation. Phosphorus removal for both soils was limited by physical nonequilibrium instead of chemical nonequilibrium (sorption kinetics). For the Clear Creek soil, the ITC analysis illustrated that P sorption was limited more by physical diffusion of P through micropores to sorption sites rather than chemical kinetics. For the Barren Fork soil, results indicated that the limiting process was pore scale transport from bulk flow to sorption sites, which was a function of flow rate. The calorimetry approach presented can help provide soil-specific information on the risk of P inputs to leaching (degree of P sorption) under different conditions (flow rate or RT), and potential for desorption (P sorption mechanisms). C2 - 2013/// C3 - 2013 Kansas City, Missouri, July 21 - July 24, 2013 CY - Kansas City, Missouri DA - 2013/// PY - 2013/7/21/ DO - 10.13031/aim.20131621201 M1 - 131621201 PB - American Society of Agricultural and Biological Engineers ER - TY - CONF TI - Application of excess shear stress and mechanistic detachment rate models for the erodibility of cohesive soils AU - Daly, E.R. AU - Fox, G.A. AU - Al-Madhhachi, A.-S.T. C2 - 2013/// C3 - American Society of Agricultural and Biological Engineers Annual International Meeting 2013, ASABE 2013 DA - 2013/// VL - 3 SP - 2540-2550 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84881643806&partnerID=MN8TOARS ER - TY - JOUR TI - Deriving Parameters of a Fundamental Detachment Model for Cohesive Soils from Flume and Jet Erosion Tests AU - Al-Madhhachi, Abdul-Sahib T. AU - Hanson, Gregory J. AU - Fox, Garey A. AU - Tyagi, Avdhesh K. AU - Bulut, Rifat T2 - Transactions of the ASABE AB - <italic>Abstract.</italic> The erosion rate of cohesive soils is commonly quantified using the excess shear stress model, which is dependent on two major soil parameters: the critical shear stress (τc) and the erodibility coefficient (kd). A submerged jet test (jet erosion test, or JET) is one method that has been developed for measuring these parameters. The disadvantage of using the excess shear stress model is that parameters τc and kd change according to erosion conditions, such as soil structure, soil orientation, type of clay, presence of roots, and seepage forces. A more mechanistically based detachment model, called the Wilson model, is proposed in this article for modeling the erosion rate of soils using hydraulic analysis of a JET. The general framework of the Wilson model is based on two soil parameters (b0 and b1). The objectives of this study were to: (1) develop methods of analysis of the JET to determine parameters b0 and b1 for the Wilson model in a similar fashion to the previous methodology developed for open-channel flow, and (2) compare the excess stress model parameter (kd) and the Wilson model parameters (b0 and b1) determined from the flume tests and JETs for two cohesive soils. Flume tests, treated as the standard test method, and original and “mini” JETs were conducted on two soils to independently measure the excess shear stress model parameter (kd) and the Wilson model parameters (b0 and b1). Soil samples of two cohesive soils (silty sand and clayey sand soils) were packed in a soil box for the flume tests and the JETs at water contents ranging from 8.7% to 18.1%. No statistically significant differences were observed for the excess shear stress model parameter (kd) and for the Wilson model parameters (b0 and b1) when determined from the flume tests and JET devices, except for b1 with the original JET. The Wilson model is advantageous in being a more mechanistic, fundamentally based erosion equation as compared to the excess shear stress model. The Wilson model can be used in place of the excess shear stress model with parameters that can be estimated using existing JET techniques. DA - 2013/// PY - 2013/// DO - 10.13031/2013.42669 VL - 56 IS - 2 SP - 489-504 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84878551266&partnerID=MN8TOARS ER - TY - JOUR TI - A scour depth approach for deriving erodibility parameters from jet erosion tests AU - Daly, E.R. AU - Fox, G.A. AU - Al-Madhhachi, A.T. AU - Miller, R.B. T2 - Transactions of the ASABE AB - Abstract. Typically the erosion rate of cohesive soils is modeled using the excess shear stress equation, which includes two soil parameters: the erodibility coefficient (kd) and the critical shear stress (τc). A jet erosion test (JET) is a standardized method available for deriving the erodibility of cohesive soils. The JET data are typically analyzed using a Blaisdell solution approach. A second solution approach based on direct parameter optimization to the measured scour depth data has recently been proposed but with limited evaluation. Therefore, the objectives of this research were to: (1) develop a new spreadsheet tool that simultaneously solves for the erodibility parameters using both solution approaches, (2) evaluate the solutions in terms of their ability to predict the observed scour depth data, and (3) quantify differences in the predicted erodibility parameters from the two approaches. A series of JETs conducted across the Illinois River watershed in eastern Oklahoma were used to evaluate the performance of the spreadsheet and the solution methodologies. The new scour depth solution provided improved fits to the original scour depth data along with being more stable in converging to a solution as a function of the initial parameter estimates. The automated spreadsheet provides an easy-to-use tool for deriving erodibility parameters from JETs. DA - 2013/// PY - 2013/// DO - 10.13031/trans.56.10350 VL - 56 IS - 6 SP - 1343-1351 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84891467711&partnerID=MN8TOARS ER - TY - CONF TI - A Mechanistic Detachment Rate Model to Predict Soil Erodibility due to Fluvial and Seepage Forces AU - Al-Madhhachi, A. T. AU - Fox, G. A. AU - Hanson, G. J. T2 - World Environmental and Water Resources Congress 2013 AB - The erosion rate of cohesive soils is typically computed using an excess shear stress model based on the applied fluvial shear stress. However, no mechanistic approaches are available for incorporating additional forces such as localized groundwater seepage forces into the excess shear stress model parameters. Seepage forces are known to be significant contributors to streambank erosion and failure. The objective of this research was to incorporate seepage forces into a mechanistic fundamental detachment rate model to improve predictions of the erosion rate of cohesive soils. The new detachment model, which is referred to as the "Modified Wilson Model," was based on two modified dimensional soil parameters (b0 and b1) that included seepage forces due to localized groundwater flow gradients. The proposed model provided a general framework for studying the impact of soil properties, fluid characteristics, and seepage forces on cohesive soil erodibility. The proposed model will be described and methods of analysis will be presented for deriving the material parameters from flume tests and jet erosion tests (JETs). To investigate the influence of seepage on erodibility, innovative submerged JETs and larger-scale flume experiments were conducted including cases with and without seepage. Seepage forces influenced the erodibility parameters (b0 and b1) and the corresponding predicted erosion rates. As expected, increased seepage gradients or forces decreased b1 and increased b0 for both flume tests and JETs. The influence of seepage on erosion can be predicted using the "Modified Wilson Model" parameters with a priori flume and/or JET experiments without seepage. Erodibility parameters with or without seepage from flume experiments were statistically equivalent to those derived using JETs. The "Modified Wilson Model" is advantageous in being a more mechanistic, fundamentally based erosion equation that can replace the more commonly used empirical detachment models such as the excess shear stress model. C2 - 2013/5/28/ C3 - World Environmental and Water Resources Congress 2013 DA - 2013/5/28/ DO - 10.1061/9780784412947.158 SP - 1608-1618 PB - American Society of Civil Engineers SN - 9780784412947 UR - http://dx.doi.org/10.1061/9780784412947.158 DB - Crossref ER - TY - JOUR TI - Application of Excess Shear Stress and Mechanistic Detachment Rate Models for the Erodibility of Cohesive Soils AU - Fox, Garey A AU - Al-Madhhachi, Abdul-Sahib AU - Daly, Erin R T2 - 2013 Kansas City, Missouri, July 21 - July 24, 2013 AB - Abstract. Typically the erosion rate of cohesive soils is modeled using the excess shear stress equation, which includes two soil parameters: the erodibility coefficient (kd) and the critical shear stress (τc). Alternatively, a mechanistic detachment rate model (“Wilson Model”) was recently developed to predict the erosion rate of cohesive soils. The general framework of the “Wilson Model” was based on two soil parameters: b0 and b1. The “Wilson Model” is advantageous in being a more mechanistic, fundamentally based erosion equation as compared to the more commonly utilized excess shear stress model. The objective of this research was to derive the excess shear stress model parameters (kd and τc) from field jet erosion tests (JETs) on numerous streambanks across the Illinois River watershed to further investigate the erodibility parameters relative to parameter uniformity, correlations between the derived parameters and soil texture, and the applicability of predictive relationships between kd and τc. The second objective was to demonstrate the applicability of the “Wilson Model” using field JET data. If a shift to the more fundamentally based “Wilson Model” is expected, similar investigations into parameter uniformity and correlations are needed. This study also investigated correlations between the excess shear stress model parameters, kd and τc, and the “Wilson Model” parameters, b0 and b1. A new miniature version of JET device (“mini” JET) was performed on streambanks of varying soil texture within the Illinois River Watershed in northeastern Oklahoma. Soil samples were acquired at locations of the JETs to measure the particle size distribution, average particle size (d50) and bulk density. When considering correlations between the derived parameters and soil texture, no significant relationships existed between kd or τc and bulk density, d50, percent clay, silt, or sand, or percent clay-silt. Existing empirical relationships should be used with caution considering the variability between the results observed in this research and previous relationships proposed in the literature. Strong correlations were observed between b0 and kd (R2 = 0.90) and between b1 and τc (R2 = 0.93). Therefore, the Wilson Model parameters closely resemble the empirical excess shear stress parameters, but can be mechanistically defined to account for multiple forces acting during the erosion process. DA - 2013/// PY - 2013/// DO - 10.13031/aim.20131596568 ER - TY - JOUR TI - In Situ Soil Pipeflow Experiments on Contrasting Streambank Soils AU - Midgley, Taber L. AU - Fox, Garey A. AU - Wilson, Glenn V. AU - Felice, Rachel AU - Heeren, Derek T2 - Transactions of the ASABE AB - Abstract. Soil piping has been attributed as a potential mechanism of instability of embankments and streambanks. Limited field work has been conducted on quantifying and modeling pipeflow and internal erosion processes in the field with either natural or artificially created soil pipes. This research utilized an innovative constant-head trench system to conduct constant-head soil pipe experiments in two contrasting streambanks: Dry Creek in northern Mississippi and Cow Creek in northern Oklahoma. Experiments included open pipes, in which the soil pipe was directly connected to the constant-head trench and open at the streambank face, and clogged pipes, which involved plugging the outlet of the soil pipe using soil excavated adjacent to the pipe. A tensiometer network was used to measure soil water pressures surrounding open and clogged pipe outlets on the streambank face. When pipeflow occurred, flow and sediment samples were collected using flow collection pans to quantify sediment concentrations. Flow and sediment data were used with an existing turbulent pipeflow and internal erosion model to estimate erodibility and critical shear stress properties of the soils, which were subsequently compared to similar properties derived from jet erosion tests. Clogged soil pipes resulted in pore water pressure increases in the soil adjacent to the pipe, which generally remained below saturation during these experimental periods, except at locations close to the plug. Depending on the density of the plugged soil material, the clogged soil pipes either burst, resulting in turbulent pipeflow, or were manually punctured to establish pipeflow. Calibrated critical shear stress from the turbulent pipeflow and internal erosion model matched that observed from jet erosion tests for the less erodible soils on the Dry Creek streambank, where sediment concentrations were consistently below 2 g L-1 even with fairly large hydraulic gradients on the pipe (0.3 m m-1). Calibrated erodibility coefficients were much smaller than those measured with jet erosion tests. For the more erodible streambank soils of Cow Creek, sediment concentrations approached 40 g L-1. There is a need for improved pipeflow modeling that accounts for rapidly changing pipe geometries, partially filled soil pipes, and pipeflow/soil matrix interactions. DA - 2013/// PY - 2013/// DO - 10.13031/2013.42685 VL - 56 IS - 2 SP - 479-488 ER - TY - JOUR TI - Reducing uncertainty in the calibration and validation of the INCA-N model by using soft data AU - Randall Etheridge, J. AU - Lepistö, Ahti AU - Granlund, Kirsti AU - Rankinen, Katri AU - Birgand, François AU - Burchell, Michael R., II T2 - Hydrology Research AB - Process-based nutrient models are increasingly used to determine the impact of future changes in land use, agriculture production practices and climate on the quantity and timing of nutrients reaching surface waters. Calibration of catchment-scale models to observed conditions can be difficult due to parameter uncertainty and the heterogeneity of catchment processes. Soft data, i.e. knowledge of processes gained through experimentation, have been suggested as one method of reducing uncertainty and producing a more accurate model of the processes that occur in a catchment. In this work, the Integrated Catchment model for Nitrogen was calibrated and validated for the Yläneenjoki catchment in south-western Finland by incorporating soft data. The calibration for 2003–2008 produced an adequate model of the in-stream nitrate concentrations (R2 = 0.45, NS = 0.42). However, model validation using data from 1997–2002 showed that the simulated in-stream nitrate concentrations were above the observed concentrations throughout the entire period (R2 = 0.34, NS &lt; 0). These results show that soft data can be used to constrain model parameters, resulting in a more accurate model of the catchment, but do not guarantee the best validation results as the simulated processes may not occur at the same time and rate as they did in the catchment. DA - 2013/6/25/ PY - 2013/6/25/ DO - 10.2166/nh.2013.039 VL - 45 IS - 1 SP - 73-88 LA - en OP - SN - 0029-1277 2224-7955 UR - http://dx.doi.org/10.2166/nh.2013.039 DB - Crossref KW - catchment KW - modeling KW - nitrogen KW - soft data ER - TY - BOOK TI - Techniques for characterization of particulate matter emitted from animal feeding operations AU - Wang-Li, L. AB - In agricultural air quality studies, characterization of particulate matter (PM) emitted from animal feeding operations (AFOs) are of growing interest. Due to a lack of reference methods for AFO PM studies, significant variations in PM measurements exist among studies. Moreover, due to inherent limitations, different PM measurement techniques may give different results when used to sample PM in the same environment. A given technique may also demonstrate different magnitudes of sampling errors when exposed to different environmental conditions (e.g., humidity, etc.) or to PM with different characteristics (e.g. particle size, volatility, etc.). This chapter examines the scientific principles of various PM measurement techniques such that strengths and limitations of the techniques are revealed. Knowledge about causative factors associated with the limitations will lead to the appropriate selection of specific techniques to achieve the research goals for different sampling scenarios. DA - 2013/// PY - 2013/// DO - 10.1021/bk-2013-1126.ch002 VL - 1126 SE - 15-39 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84905409194&partnerID=MN8TOARS ER - TY - JOUR TI - Organic and elemental carbons in atmospheric fine particulate in an animal agriculture intensive area in North Carolina: estimation of secondary organic carbon concentration T2 - Open Journal of Air Pollution DA - 2013/2/15/ PY - 2013/2/15/ ER - TY - ER - TY - JOUR TI - Reliability and discriminatory testing of a client-based metrology instrument, feline musculoskeletal pain index (FMPI) for the evaluation of degenerative joint disease-associated pain in cats AU - Benito, J. AU - DePuy, V. AU - Hardie, E. AU - Zamprogno, H. AU - Thomson, A. AU - Simpson, W. AU - Roe, S. AU - Hansen, B. AU - Lascelles, B.D.X. T2 - The Veterinary Journal AB - The objective of this study was to test the readability, reliability, repeatability and discriminatory ability of an owner-completed instrument to assess feline degenerative joint disease (DJD)-associated pain (feline musculoskeletal pain index, FMPI). Readability was explored using four different formulas (Flesch, Fry, SMOG and FOG) and the final FMPI instrument was produced. To assess the instrument, client-owned cats that were defined as normal (normal group) or as having DJD-associated pain and mobility impairment (pain-DJD group) were recruited. A total of 32 client-owned cats were enrolled in the study (normal, n=13; pain-DJD, n=19). Owners completed the FMPI on two occasions, 14days apart. Internal consistency (reliability) and repeatability (test-retest) were explored using Cronbach's α and weighted κ statistic, respectively. Data from the two groups were compared using analysis of covariance (controlling for age) to evaluate discriminatory ability. The FMPI was constructed with 21 questions covering activity, pain intensity and overall quality of life. It had a 6th grade readability score. Reliability of the FMPI was excellent (Cronbach's α>0.8 for all groupings of questions in normal and pain-DJD cats) and repeatability was good (weighted κ statistic >0.74) for normal and pain-DJD cats. All components of the FMPI were able to distinguish between normal cats and cats with DJD (P<0.001 for all components). This initial evaluation of the FMPI suggests that this instrument is worthy of continued investigation. DA - 2013/6// PY - 2013/6// DO - 10.1016/j.tvjl.2012.12.015 VL - 196 IS - 3 SP - 368-373 J2 - The Veterinary Journal LA - en OP - SN - 1090-0233 UR - http://dx.doi.org/10.1016/j.tvjl.2012.12.015 DB - Crossref KW - Assessment KW - Degenerative joint disease KW - Feline KW - Pain ER - TY - RPRT TI - Composting at NC residential and summer camps AU - Sherman, R. AU - Caldwell, E. DA - 2013/// PY - 2013/// M1 - AG‐773. SN - AG‐773. ER - TY - JOUR TI - Effects of surface texturing on micro algal cell attachment to solid carriers AU - Cui, Y. AU - Yuan, W. Q. AU - Cao, J. T2 - International Journal of Agricultural and Biological Engineering DA - 2013/// PY - 2013/// VL - 6 IS - 4 SP - 44-54 ER - TY - JOUR TI - Synthesis of solid acid catalyst from tobacco stalk for esterification of oleic acid AU - Jairam, S. AU - Kolar, P. AU - Sharma-Shivappa, R. S. AU - Osborne, J. A. T2 - Applied Engineering in Agriculture DA - 2013/// PY - 2013/// VL - 29 IS - 3 SP - 385-389 ER - TY - JOUR TI - Effects of drainage water management on crop yields in North Carolina AU - Poole, C. A. AU - Skaggs, R. W. AU - Cheschier, G. M. AU - Youssef, M. A. AU - Crozier, C. R. T2 - JOURNAL OF SOIL AND WATER CONSERVATION AB - Research studies on a wide range of soils, crops, locations, and climates have shown that drainage water management (DWM), or controlled drainage (CD), can be used to substantially reduce the loss of nitrogen (N), and in some cases, phosphorus (P) from drained agricultural lands to surface waters. The adoption and widespread application of DWM depends on a variety of factors including its impact on crop yields. This paper presents results from a long term field study on the effect of DWM or CD on crop yields in a three-crop, two-year corn/wheat–soybean rotation. Yields were measured on replicated field scale plots under CD and conventional or free drainage (FD) treatments for a total of 18 crops on two experimental sites during the period from 1990 to 2011. Data were collected on 7 corn (Zea mays L.) crops, 5 wheat (Triticum aestivum L.) crops, and 6 soybean (Glycine max L.) crops. Controlled drainage had no significant effect on yields of winter wheat, which in North Carolina is grown in the wettest, coolest part of the year. Controlled drainage increased corn yields compared to FD in all seven years. The average yield increase for corn was 11%. Controlled drainage also increased soybean yield in all years with an average increase of 10% compared to FD. Such yield responses will promote the application of DWM, which will result in both economic and environmental benefits. DA - 2013/// PY - 2013/// DO - 10.2489/jswc.68.6.429 VL - 68 IS - 6 SP - 429-437 SN - 1941-3300 KW - controlled drainage KW - corn KW - drainage water management KW - soybean KW - wheat KW - yield ER - TY - JOUR TI - A centrifuge-based procedure for suspended solids measurements in lagoon sludge AU - Classen, J. J. AU - Chandler, W. J. AU - Huie, R. S. AU - Osborne, J. A. T2 - Transactions of the ASABE DA - 2013/// PY - 2013/// VL - 56 IS - 2 SP - 747-752 ER - TY - JOUR TI - Review of nitrogen fate models applicable to forest landscapes in the southern US AU - Amatya, D. M. AU - Rossi, C. G. AU - Saleh, A. AU - Dai, Z. AU - Youssef, M. A. AU - Williams, R. G. AU - Bosch, D. D. AU - Chescheir, G. M. AU - Sun, G. AU - Skaggs, R. W. AU - Trettin, C. C. AU - Vance, E. D. AU - Nettles, J. E. AU - Tian, S. T2 - Transactions of the ASABE AB - <italic>Abstract.</italic> Assessing the environmental impacts of fertilizer nitrogen (N) used to increase productivity in managed forests is complex due to a wide range of abiotic and biotic factors affecting its forms and movement. Models developed to predict fertilizer N fate (e.g., cycling processes) and water quality impacts vary widely in their design, scope, and potential application. We review the applicability of five commonly used eco-hydrologic models (APEX, MIKESHE-DNDC, DRAINMOD-FOREST, REMM, and SWAT) in assessing N fate and transport in southern forest landscapes (<50 km2) because of their comprehensiveness and multi-scale predictions. The field-scale models DRAINMOD-FOREST and REMM contain process-level components characterizing hydrology, forest growth, and N dynamics, but they have limited capability to describe transport processes at the landscape scale. APEX can describe hydrology, forest growth, N fate processes, and plant competition at the landscape and small watershed scales mostly for upland. SWAT is best suited to hydrologic simulations at watershed scale (>50 km2), although N routing below the subbasin level does not yet exist. Similarly, the distributed MIKESHE-DNDC model has been used to assess N cycles across different spatial scales, on both uplands and lowlands, but was not intended to model lateral N transport. However, MIKESHE alone is capable of describing the hydrology and N transport. The strengths of each of the models reflect their original design and scope intent. Based on this review, none of the five models that we considered is independently adequate to address the fate of N fertilizers applied to forest stands at both small and large scales, including uplands and lowlands. While efforts are underway to extend these tools’ capabilities and address their various limitations, the models must be validated using experimental data before using their outputs, together with uncertainty analysis, for developing forest fertilization guidelines and the fate and transport of N. DA - 2013/// PY - 2013/// DO - 10.13031/trans.56.10096 VL - 56 IS - 5 SP - 1731-1757 ER - TY - JOUR TI - Measuring flow in non-ideal conditions for short-term projects: Uncertainties associated with the use of stage-discharge rating curves AU - Birgand, François AU - Lellouche, Guillaume AU - Appelboom, T.W. T2 - Journal of Hydrology AB - The vast majority of hydrological stations are set up such that discharge can be estimated from the sole measurement of water height or stage above a local datum. Hydraulics laws show that in the right conditions there may be a unique and stable relationship between stage and discharge, which can be described by a rating curve. For short-term projects where there may be little choice for station location and time to construct a detailed rating curve, conditions for the use of rating curves may be less than ideal, potentially yielding high uncertainties on hydrologic measurements. This article evaluates uncertainties induced on instantaneous flow rates and cumulative annual flow volumes by the use of one-segmented rating curves in small streams. Uncertainty distributions were obtained by simulating rating curves calculated from random sampling of reference flow and stage data obtained with Doppler flowmeters. Factors tested included the number of manual gauged points, the type of rating curve (power vs polynomial), the use or not of the observed stage-of-zero flow, the spread of gauged points along flow range, and the measurement errors during gauging. Results could vary widely depending on the scenarios tested and sometimes yielded very high uncertainties. The best scenario yielded significant uncertainties on annual cumulative flow volume included between −13% and +14% for the low gradient streams and between −5% and +7% for the higher gradient streams, and for 22 manual gauged points per year. Our results show that, even in the best scenario, very significant uncertainty can result from using one-segmented rating curve in non-ideal situations in the field. DA - 2013/10// PY - 2013/10// DO - 10.1016/j.jhydrol.2013.09.007 VL - 503 SP - 186-195 J2 - Journal of Hydrology LA - en OP - SN - 0022-1694 UR - http://dx.doi.org/10.1016/j.jhydrol.2013.09.007 DB - Crossref KW - Hydrometry KW - Uncertainties KW - Rating curves KW - Stage-discharge relationship ER - TY - JOUR TI - Live performance of roasters raised in houses receiving different acidifier application rates AU - Oviedo-Rondon, E. O. AU - Shah, S. B. AU - Grimes, J. L. AU - Westerman, P. W. AU - Campeau, D. T2 - JOURNAL OF APPLIED POULTRY RESEARCH AB - The reutilization of litter is currently a common practice in broiler production due to several environmental and economic factors. The application of litter amendments in broiler houses is a popular practice that can reduce ammonia emissions from recycled litter by converting them to nonvolatile ammonium. Sodium bisulfate (SBS) is one of the acidifiers frequently used in broiler houses. Broilers raised to 9 wk may require higher acidifier application rates to prevent unhealthy NH3 levels throughout the flock than broilers raised to smaller sizes. A study with 6 flocks of roasters was conducted under commercial conditions to evaluate 4 levels of SBS. In a farm with 8 houses, 4 treatments were evaluated. In the control treatment 0.49 kg/m2 of SBS was applied to the brood chamber, whereas the low, medium, and high treatments received 0.49, 0.73, and 1.46 kg/m2, respectively, in the whole house. Data were obtained as the average of 2 houses with approximately 21,000 broilers per house in each of the 6 flocks evaluated. Results indicated no significant differences due to treatments on final average BW, FCR, mortality, or the majority of condemnation parameters. The significant reductions in NH3 levels observed in the whole flock across all 6 flocks receiving SBS treatments did not significantly improve broiler live performance or affect condemnations at the processing plant. DA - 2013/12// PY - 2013/12// DO - 10.3382/japr.2012-00716 VL - 22 IS - 4 SP - 922-928 SN - 1537-0437 KW - ammonia KW - roaster KW - litter amendment KW - sodium bisulfate ER - TY - JOUR TI - Development of an Incurred Cornbread Model for Gluten Detection by Immunoassays AU - Sharma, Girdhari M. AU - Khuda, Sefat E. AU - Pereira, Marion AU - Slate, Andrew AU - Jackson, Lauren S. AU - Pardo, Christopher AU - Williams, Kristina M. AU - Whitaker, Thomas B. T2 - JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY AB - Gluten that is present in food as a result of cross-contact or misbranding can cause severe health concerns to wheat-allergic and celiac patients. Immunoassays, such as enzyme-linked immunosorbent assay (ELISA) and lateral flow device (LFD), are commonly used to detect gluten traces in foods. However, the performance of immunoassays can be affected by non-assay-related factors, such as food matrix and processing conditions. Gluten (0-500 ppm) and wheat flour (20-1000 ppm) incurred cornbread was prepared at different incurred levels and baking conditions (204.4 °C for 20, 27, and 34 min) to study the accuracy and precision of gluten measurement by seven immunoassay kits (three LFD and four ELISA kits). The stability and immunoreactivity of gluten proteins, as measured by western blot using three different antibodies, were not adversely affected by the baking conditions. However, the gluten recovery varied depending upon the ELISA kit and the gluten source used to make the incurred cornbread, affecting the accuracy of gluten quantification (BioKits, 9-77%; Morinaga, 91-137%; R-Biopharm, 61-108%; and Romer Labs, 113-190%). Gluten recovery was reduced with increased baking time for most ELISA kits analyzed. Both the sampling and analytical variance increased with an increase in the gluten incurred level. The predicted analytical coefficient of variation associated with all ELISA kits was below 12% for all incurred levels, indicative of good analytical precision. DA - 2013/12/11/ PY - 2013/12/11/ DO - 10.1021/jf404072x VL - 61 IS - 49 SP - 12146-12154 SN - 1520-5118 KW - Gluten KW - ELISA KW - immunoassay KW - incurred food KW - thermal processing ER - TY - JOUR TI - Conducting an Agricultural Life Cycle Assessment: Challenges and Perspectives AU - Caffrey, Kevin R. AU - Veal, Matthew W. T2 - SCIENTIFIC WORLD JOURNAL AB - Agriculture is a diverse field that produces a wide array of products vital to society. As global populations continue to grow the competition for natural resources will increase pressure on agricultural production of food, fiber, energy, and various high value by-products. With elevated concerns related to environmental impacts associated with the needs of a growing population, a life cycle assessment (LCA) framework can be used to determine areas of greatest impact and compare reduction strategies for agricultural production systems. The LCA methodology was originally developed for industrial operations but has been expanded to a wider range of fields including agriculture. There are various factors that increase the complexity of determining impacts associated with agricultural production including multiple products from a single system, regional and crop specific management techniques, temporal variations (seasonally and annually), spatial variations (multilocation production of end products), and the large quantity of nonpoint emission sources. The lack of consistent methodology of some impacts that are of major concern to agriculture (e.g., land use and water usage) increases the complexity of this analysis. This paper strives to review some of these issues and give perspective to the LCA practitioner in the field of agriculture. DA - 2013/// PY - 2013/// DO - 10.1155/2013/472431 SP - SN - 1537-744X ER - TY - JOUR TI - CHARACTERIZING RAINWATER HARVESTING PERFORMANCE AND DEMONSTRATING STORMWATER MANAGEMENT BENEFITS IN THE HUMID SOUTHEAST USA AU - DeBusk, K. M. AU - Hunt, W. F. AU - Wright, J. D. T2 - JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION AB - Abstract Rainwater harvesting ( RWH ) has traditionally been implemented in areas with (semi) arid climates or limited access to potable water supplies; however, recent droughts in the humid southeastern United States have led to increased implementation of RWH systems. The objectives of this study were twofold: (1) present usage characteristics and performance results for four RWH systems installed in humid North Carolina ( NC ) as compared with systems located in arid/semiarid regions and (2) identify system benefits and modifications that could help improve the performance of RWH systems installed in humid regions of the world. For this study four RWH systems were installed in NC . Their usage was monitored for at least one year and compared with similar studies. Results revealed that dedicated water uses and usage characteristics for RWH systems in NC differed from those previously reported in the literature. Two of the systems studied met 100 and 61% of the potable water demand with designated uses of animal kennel flushing and greenhouse irrigation, respectively. The designated uses yielding the greatest potable water replacement were often seasonal or periodic, thus necessitating the need for identifying and implementing secondary objectives for these systems, namely, stormwater management. Otherwise, the expense and effort required to implement RWH systems in humid areas will most likely preclude their use. DA - 2013/12// PY - 2013/12// DO - 10.1111/jawr.12096 VL - 49 IS - 6 SP - 1398-1411 SN - 1752-1688 KW - stormwater management KW - rainwater harvesting KW - water conservation KW - water use KW - best management practices ER - TY - JOUR TI - Thermodynamic modeling of algal cell-solid substrate interactions AU - Cui, Yan AU - Yuan, Wenqiao T2 - APPLIED ENERGY AB - The process of microalgal cell attachment to solid-carrier surfaces was simulated through a thermodynamic model. The modeling results showed that, for most microbes, when the polar surface energy of the cell is smaller than that of water, cellular attachment would be more favorable on materials with higher dispersive surface energy but lower polar surface energy. If the polar surface energy of the cell is greater than that of water, more cell attachment would be expected on materials that are higher in both dispersive and polar surface energies. Modeling results qualitatively matched experimental data in the attachment of a freshwater alga, Scenedesmus dimorphus, and a marine alga, Nannochloropsis oculata, on five materials (nylon, stainless steel, polycarbonate, polypropylene, and glass). The model was also validated by published literature data on a wider variety of microbes and materials, indicating that the model developed can be applicable in designing, selecting, and matching algal strains and solid carrier materials to enhance cell attachment. DA - 2013/12// PY - 2013/12// DO - 10.1016/j.apenergy.2013.03.036 VL - 112 SP - 485-492 SN - 1872-9118 KW - Biofuel KW - Microalgae KW - Cell attachment KW - Thermodynamic model KW - Surface energy ER - TY - JOUR TI - River flux uncertainties predicted by hydrological variability and riverine material behaviour AU - Moatar, Florentina AU - Meybeck, Michel AU - Raymond, Sebastien AU - Birgand, Francois AU - Curie, Florence T2 - HYDROLOGICAL PROCESSES AB - Abstract Data on riverine fluxes are essential for calculating element cycles (carbon, nutrients, pollutants) and erosion rates from regional to global scales. At most water‐quality stations throughout the world, riverine fluxes are calculated from continuous flow data ( q ) and discrete concentration data ( C ), the latter being the main cause of sometimes large uncertainties. This article offers a comprehensive approach for predicting the magnitude of these uncertainties for water‐quality stations in medium to large basins (drainage basin area > 1000 km²) based on the commonly used discharge‐weighted method. Uncertainty levels – biases and imprecisions – for sampling intervals of 3 to 60 days are correlated first through a nomograph with a flux variability indicator, the quantity of riverine material discharged in 2% of time ( M 2% ). In turn, M 2% is estimated from the combination of a hydrological reactivity index, W 2% (the cumulative flow volume discharged during the upper 2% of highest daily flow) and the truncated b 50sup exponent, quantifying the concentration versus discharge relationship for the upper half of flow values ( C = a q b 50sup , for q > q 50 , where q 50 is the median flow): M 2% = W 2% + 27.6 b 50sup . W 2% can be calculated from continuous flow measurements, and the b 50sup indicator can be calculated from infrequent sampling, which makes it possible to predict a priori the level of uncertainty at any station, for any type of riverine material either concentrated ( b 50sup > 0) or diluted ( b 50sup > 0) with flow. A large data base of daily surveys, 125 station variables of suspended particulate matter (SPM), total dissolved solids (TDS) and dissolved and particulate nutrients, was used to determine uncertainties from simulated discrete surveys and to establish relationships between indicators. Results show, for example, that for the same relatively reactive basin ( W 2% > 25%), calculated fluxes from monthly sampling would yield uncertainties approaching ±100% for SPM ( b 50sup > 1.4) fluxes and ±10% for TDS ( b 50sup = −0.2). The application to the nitrate survey of the river Seine shows significant trends for the 1972–2009 records. Copyright © 2012 John Wiley & Sons, Ltd. DA - 2013/12/15/ PY - 2013/12/15/ DO - 10.1002/hyp.9464 VL - 27 IS - 25 SP - 3535-3546 SN - 1099-1085 KW - riverine fluxes KW - flux duration indicators KW - uncertainties KW - suspended particulate matter KW - total dissolved solids KW - nutrients ER - TY - JOUR TI - Effects of Biomass Feedstocks and Gasification Conditions on the Physiochemical Properties of Char AU - Qian, Kezhen AU - Kumar, Ajay AU - Patil, Krushna AU - Bellmer, Danielle AU - Wang, Donghai AU - Yuan, Wenqiao AU - Huhnke, Raymond L. T2 - ENERGIES AB - Char is a low-value byproduct of biomass gasification and pyrolysis with many potential applications, such as soil amendment and the synthesis of activated carbon and carbon-based catalysts. Considering these high-value applications, char could provide economic benefits to a biorefinery utilizing gasification or pyrolysis technologies. However, the properties of char depend heavily on biomass feedstock, gasifier design and operating conditions. This paper reports the effects of biomass type (switchgrass, sorghum straw and red cedar) and equivalence ratio (0.20, 0.25 and 0.28), i.e., the ratio of air supply relative to the air that is required for stoichiometric combustion of biomass, on the physiochemical properties of char derived from gasification. Results show that the Brunauer-Emmett-Teller (BET) surface areas of most of the char were 1–10 m2/g and increased as the equivalence ratio increased. Char moisture and fixed carbon contents decreased while ash content increased as equivalence ratio increased. The corresponding Fourier Transform Infrared spectra showed that the surface functional groups of char differed between biomass types but remained similar with change in equivalence ratio. DA - 2013/8// PY - 2013/8// DO - 10.3390/en6083972 VL - 6 IS - 8 SP - 3972-3986 SN - 1996-1073 KW - biomass char KW - biochar KW - gasification KW - fluidized bed KW - switchgrass KW - sorghum KW - eastern red cedar ER - TY - JOUR TI - ESTIMATING SUSPENDED SOLIDS FROM TURBIDITY IN THE ROBESON CREEK, NC WATERSHED AU - Line, D. E. AU - Hall, K. R. AU - Blackwell, J. D. T2 - JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION AB - Abstract The purpose of this project was to assess the effect of estimating total suspended solids ( TSS ) concentrations from turbidity on TSS loads for streams in the R obeson C reek watershed. Discharge was monitored continuously and base‐flow grab and storm event composite samples were collected and analyzed for TSS and turbidity from five sites during five years of monitoring. For base‐flow samples, the TSS ‐turbidity relationship for all five sites was poor indicating that TSS concentrations in base flow cannot be estimated from a TSS ‐turbidity relationship. To test the effect of analyzing fewer samples, TSS from every third and the first 20 samples collected from each site was used to develop TSS ‐turbidity relationships. In addition, the TSS ‐turbidity relationship developed from the most downstream site was used to estimate TSS concentrations from turbidity measured at the other four sites. For four of the five sites, analyzing every third sample for TSS and using the TSS ‐turbidity relationship to estimate the missing TSS concentrations would result in mean TSS loads that were not significantly different from the observed. Using the TSS ‐turbidity relationship from the outlet to estimate TSS from turbidity measured at the other four sites resulted in significantly different mean TSS loads at three of the four sites. These results indicate that estimating TSS concentrations from turbidity using a TSS ‐turbidity relationship developed from a subset of the overall dataset should be done with great caution. DA - 2013/12// PY - 2013/12// DO - 10.1111/jawr.12094 VL - 49 IS - 6 SP - 1412-1420 SN - 1752-1688 KW - turbidity KW - environmental sampling KW - nonpoint source pollution KW - total suspended solids ER - TY - JOUR TI - Comparative phenotypic analysis and genome sequence of Clostridium beijerinckii SA-1, an offspring of NCIMB 8052 AU - Sandoval-Espinola, Walter J. AU - Makwana, Satya T. AU - Chinn, Mari S. AU - Thon, Michael R. AU - Andrea Azcarate-Peril, M. AU - Bruno-Barcena, Jose M. T2 - MICROBIOLOGY-SGM AB - Production of butanol by solventogenic clostridia is controlled through metabolic regulation of the carbon flow and limited by its toxic effects. To overcome cell sensitivity to solvents, stress-directed evolution methodology was used three decades ago on Clostridium beijerinckii NCIMB 8052 that spawned the SA-1 strain. Here, we evaluated SA-1 solventogenic capabilities when growing on a previously validated medium containing, as carbon- and energy-limiting substrates, sucrose and the products of its hydrolysis d-glucose and d-fructose and only d-fructose. Comparative small-scale batch fermentations with controlled pH (pH 6.5) showed that SA-1 is a solvent hyper-producing strain capable of generating up to 16.1 g l(-1) of butanol and 26.3 g l(-1) of total solvents, 62.3 % and 63 % more than NCIMB 8052, respectively. This corresponds to butanol and solvent yields of 0.3 and 0.49 g g(-1), respectively (63 % and 65 % increase compared with NCIMB 8052). SA-1 showed a deficiency in d-fructose transport as suggested by its 7 h generation time compared with 1 h for NCIMB 8052. To potentially correlate physiological behaviour with genetic mutations, the whole genome of SA-1 was sequenced using the Illumina GA IIx platform. PCR and Sanger sequencing were performed to analyse the putative variations. As a result, four errors were confirmed and validated in the reference genome of NCIMB 8052 and a total of 10 genetic polymorphisms in SA-1. The genetic polymorphisms included eight single nucleotide variants, one small deletion and one large insertion that it is an additional copy of the insertion sequence ISCb1. Two of the genetic polymorphisms, the serine threonine phosphatase cbs_4400 and the solute binding protein cbs_0769, may possibly explain some of the observed physiological behaviour, such as rerouting of the metabolic carbon flow, deregulation of the d-fructose phosphotransferase transport system and delayed sporulation. DA - 2013/12// PY - 2013/12// DO - 10.1099/mic.0.069534-0 VL - 159 SP - 2558-2570 SN - 1465-2080 ER - TY - JOUR TI - Addressing the Fouling of In Situ Ultraviolet-Visual Spectrometers Used to Continuously Monitor Water Quality in Brackish Tidal Marsh Waters AU - Etheridge, J. Randall AU - Birgand, François AU - Burchell, Michael R. AU - Smith, Brad T. T2 - Journal of Environment Quality AB - The introduction of portable in situ ultraviolet-visual spectrometers has made possible the collection of water quality parameters at a high frequency in dynamic systems such as tidal marshes. The usefulness of this technology is inhibited by fouling of the instrument's optics. In this study, a spectrometer fitted with manufacturer-recommended compressed air optical cleaning was installed in a brackish marsh to determine if fouling interfered with measurements between bi-weekly servicing. During a 2-wk period, the absorbance measured in air at 220 nm increased from 9 to 549 m, indicating major fouling. An antifouling system was developed that reduced the time of exposure of the optics to stream water and used a pressurized fresh water cleaning. After implementation of the system, the absorbance in air increased to at most 63 m after 2 wk of data collection. The dramatic reduction in fouling will allow quality long-term data to be collected using this technology. DA - 2013/// PY - 2013/// DO - 10.2134/jeq2013.02.0049 VL - 42 IS - 6 SP - 1896 LA - en OP - SN - 0047-2425 UR - http://dx.doi.org/10.2134/jeq2013.02.0049 DB - Crossref ER - TY - JOUR TI - Potential of ozonolysis as a pretreatment for energy grasses AU - Panneerselvam, Anushadevi AU - Sharma-Shivappa, Ratna R. AU - Kolar, Praveen AU - Ranney, Thomas AU - Peretti, Steven T2 - BIORESOURCE TECHNOLOGY AB - This study investigated the effect of ozonolysis on Miscanthus × giganteus, Miscanthus sinensis 'Gracillimus', Saccharum arundinaceum and Saccharum ravennae, collectively referred to as 'energy grasses'. Studies were conducted at three different ozone concentrations (40, 50 and 58 mg/l) using two ozone flow configurations - uni-directional and reversed flow. Pretreatment conditions for each variety were optimized based on lignin content and glucan recovery in ozonated solids. Results showed that ozonolysis was effective in removing up to 59.9% lignin without cellulose degradation. However, subsequent hydrolysis of pretreated solids with Cellic® CTec2 at 0.06 g/g raw biomass provided glucan conversion lower than untreated samples suggesting enzyme inhibition by lignin degradation products formed during ozonolysis. Future studies investigating hydrolysis efficiency of washed pretreated solids with higher enzyme loadings are therefore warranted to optimize the hydrolysis process and make it functionally feasible. DA - 2013/11// PY - 2013/11// DO - 10.1016/j.biortech.2013.08.129 VL - 148 SP - 242-248 SN - 1873-2976 KW - Miscanthus KW - Saccharum KW - Optimization KW - Flow configuration KW - Enzymatic hydrolysis ER - TY - JOUR TI - Hydrolysis of ozone pretreated energy grasses for optimal fermentable sugar production AU - Panneerselvam, Anushadevi AU - Sharma-Shivappa, Ratna R. AU - Kolar, Praveen AU - Clare, Debra A. AU - Ranney, Thomas T2 - BIORESOURCE TECHNOLOGY AB - Ozonated energy grass varieties were enzymatically hydrolyzed to establish process parameters for maximum fermentable sugar production. Conditions for ozonolysis were selected on the basis of maximum delignification and glucan retention after pretreatment. To study the effect of lignin degradation products generated during ozonolysis on cellulolytic enzymes, hydrolysis was carried out for washed and unwashed pretreated solids. Washing the solids significantly (p < 0.05) enhanced glucan conversion from 34.3% to 100% while delivering glucose yields of 146.2–431.9 mg/g biomass. Highest fermentable sugars were produced when grasses were ozonated for maximum delignification and washed solids were hydrolyzed using 0.1 g/g Cellic® CTec2. In a comparative study on alkaline pretreatment with 1% NaOH for 60 min, Saccharum arundinaceum exhibited the highest glucan conversion with maximum sugar production of 467.9 mg/g. Although ozonolysis is an effective and environmentally friendly technique for cellulosic sugar production, process optimization is needed to ascertain economic feasibility of the process. DA - 2013/11// PY - 2013/11// DO - 10.1016/j.biortech.2013.08.119 VL - 148 SP - 97-104 SN - 1873-2976 KW - Miscanthus KW - Saccharum KW - Optimization KW - Enzymatic hydrolysis KW - Alkali pretreatment ER - TY - JOUR TI - Source and magnitude of error in an inexpensive image-based water level measurement system AU - Gilmore, Troy E. AU - Birgand, François AU - Chapman, Kenneth W. T2 - Journal of Hydrology AB - Recent technological advances have opened the possibility to use webcams and images as part of the environmental monitoring arsenal. The potential sources and magnitude of uncertainties inherent to an image-based water level measurement system are evaluated in an experimental design in the laboratory. Sources of error investigated include image resolution, lighting effects, perspective, lens distortion and water meniscus. Image resolution and meniscus were found to weigh the most in the overall uncertainty of this system. Image distortion, although largely taken into account by the software developed, may also significantly add to uncertainty. Results suggest that “flat” images with little distortion are preferable. After correction for the water meniscus, images captured with a camera (12 mm or 16 mm focal lengths) positioned 4–7 m from the water level edge have the potential to yield water level measurements within ±3 mm when using this technique. DA - 2013/7// PY - 2013/7// DO - 10.1016/j.jhydrol.2013.05.011 VL - 496 SP - 178-186 J2 - Journal of Hydrology LA - en OP - SN - 0022-1694 UR - http://dx.doi.org/10.1016/j.jhydrol.2013.05.011 DB - Crossref KW - Water level KW - Water stage KW - Machine vision KW - Edge detection KW - Instrument comparison KW - Uncertainty ER - TY - JOUR TI - Sophia title AU - Merriman, L. S. AU - Wilson, C. E. AU - Winston, R. J. AU - Hunt, W. F. T2 - Journal of Hydrologic Engineering DA - 2013/// PY - 2013/// VL - 18 IS - 10 SP - 1372-1376 ER - TY - JOUR TI - Product sampling during transient continuous countercurrent hydrolysis of canola oil and development of a kinetic model AU - Wang, Wei-Cheng AU - Natelson, Robert H. AU - Stikeleather, Larry F. AU - Roberts, William L. T2 - COMPUTERS & CHEMICAL ENGINEERING AB - A chemical kinetic model has been developed for the transient stage of the continuous countercurrent hydrolysis of triglycerides to free fatty acids and glycerol. Departure functions and group contribution methods were applied to determine the equilibrium constants of the four reversible reactions in the kinetic model. Continuous countercurrent hydrolysis of canola oil in subcritical water was conducted experimentally in a lab-scale reactor over a range of temperatures and the concentrations of all neutral components were quantified. Several of the rate constants in the model were obtained by modeling this experimental data, with the remaining determined from calculated equilibrium constants. Some reactions not included in the present, or previous, hydrolysis modeling efforts were identified from glycerolysis kinetic studies and may explain the slight discrepancy between model and experiment. The rate constants determined in this paper indicate that diglycerides in the feedstock accelerate the transition from “emulsive hydrolysis” to “rapid hydrolysis”. DA - 2013/11/11/ PY - 2013/11/11/ DO - 10.1016/j.compchemeng.2013.06.003 VL - 58 SP - 144-155 SN - 1873-4375 KW - Hydrolysis KW - Triglycerides KW - Diglycerides KW - Free fatty acids ER - TY - JOUR TI - Enhanced allelopathy and competitive ability of invasive plant Solidago canadensis in its introduced range AU - Yuan, Yongge AU - Wang, Bing AU - Zhang, Shanshan AU - Tang, Jianjun AU - Tu, Cong AU - Hu, Shuijin AU - Yong, Jean W. H. AU - Chen, Xin T2 - JOURNAL OF PLANT ECOLOGY AB - Why invasive plants are more competitive in their introduced range than native range is still an unanswered question in plant invasion ecology. Here, we used the model invasive plant Solidago canadensis to test a hypothesis that enhanced production of allelopathic compounds results in greater competitive ability of invasive plants in the invaded range rather than in the native range. We also examined the degree to which the allelopathy contributes increased competitive ability of S. canadensis in the invaded range. We compared allelochemical production by S. canadensis growing in its native area (the USA) and invaded area (China) and also by populations that were collected from the two countries and grown together in a ‘common garden’ greenhouse experiment. We also tested the allelopathic effects of S. canadensis collected from either the USA or China on the germination of Kummerowia striata (a native plant in China). Finally, we conducted a common garden, greenhouse experiment in which K. striata was grown in monoculture or with S. canadensis from the USA or China to test the effects of allelopathy on plant–plant competition with suitable controls such as adding activated carbon to the soil to absorb the allelochemicals and thereby eliminating any corresponding allopathic effects. Allelochemical contents (total phenolics, total flavones and total saponins) and allelopathic effects were greater in S. canadensis sampled from China than those from the USA as demonstrated in a field survey and a common garden experiment. Inhibition of K. striata germination using S. canadensis extracts or previously grown in soil was greater using samples from China than from the USA. The competitive ability of S. canadensis against K. striata was also greater for plants originating from China than those from the USA. Allelopathy could explain about 46% of the difference. These findings demonstrated that S. canadensis has evolved to be more allelopathic and competitive in the introduced range and that allelopathy significantly contributes to increased competitiveness for this invasive species. DA - 2013/6// PY - 2013/6// DO - 10.1093/jpe/rts033 VL - 6 IS - 3 SP - 253-263 SN - 1752-993X KW - allelopathy KW - biogeographical approach KW - common garden experiment KW - competition KW - invasion species ER - TY - JOUR TI - Characterization of temperature and light effects on the defense response phenotypes associated with the maize Rp1-D21 autoactive resistance gene AU - Negeri, Adisu AU - Wang, Guan-Feng AU - Benavente, Larissa AU - Kibiti, Cromwell M AU - Chaikam, Vijay AU - Johal, Guri AU - Balint-Kurti, Peter T2 - BMC Plant Biology AB - Rp1 is a complex locus of maize, which carries a set of genes controlling race-specific resistance to the common rust fungus, Puccinia sorghi. The resistance response includes the "Hypersensitive response" (HR), a rapid response triggered by a pathogen recognition event that includes localized cell death at the point of pathogen penetration and the induction of pathogenesis associated genes. The Rp1-D21gene is an autoactive allelic variant at the Rp1 locus, causing spontaneous activation of the HR response, in the absence of pathogenesis. Previously we have shown that the severity of the phenotype conferred by Rp1-D21 is highly dependent on genetic background.In this study we show that the phenotype conferred by Rp1-D21 is highly dependent on temperature, with lower temperatures favoring the expression of the HR lesion phenotype. This temperature effect was observed in all the 14 genetic backgrounds tested. Significant interactions between the temperature effects and genetic background were observed. When plants were grown at temperatures above 30°C, the spontaneous HR phenotype conferred by Rp1-D21 was entirely suppressed. Furthermore, this phenotype could be restored or suppressed by alternately reducing and increasing the temperature appropriately. Light was also required for the expression of this phenotype. By examining the expression of genes associated with the defense response we showed that, at temperatures above 30°C, the Rp1-D21 phenotype was suppressed at both the phenotypic and molecular level.We have shown that the lesion phenotype conferred by maize autoactive resistance gene Rp1-D21 is temperature sensitive in a reversible manner, that the temperature-sensitivity phenotype interacts with genetic background and that the phenotype is light sensitive. This is the first detailed demonstration of this phenomenon in monocots and also the first demonstration of the interaction of this effect with genetic background. The use of temperature shifts to induce a massive and synchronous HR in plants carrying the Rp1-D21 genes will be valuable in identifying components of the defense response pathway. DA - 2013/// PY - 2013/// DO - 10.1186/1471-2229-13-106 VL - 13 IS - 1 SP - 106 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84880860512&partnerID=MN8TOARS KW - Maize KW - Hypersensitive response KW - Disease resistance KW - Temperature sensitive KW - Light dependent KW - Rp1 KW - Autoactive R gene ER - TY - JOUR TI - Analysis of Consecutive Events for Nutrient and Sediment Treatment in Field-Monitored Bioretention Cells AU - Brown, Robert A. AU - Birgand, Francois AU - Hunt, William F. T2 - Water, Air, & Soil Pollution DA - 2013/5/5/ PY - 2013/5/5/ DO - 10.1007/s11270-013-1581-6 VL - 224 IS - 6 SP - J2 - Water Air Soil Pollut LA - en OP - SN - 0049-6979 1573-2932 UR - http://dx.doi.org/10.1007/s11270-013-1581-6 DB - Crossref KW - Bioretention KW - Stormwater KW - Nutrients KW - Nitrogen KW - Phosphorus KW - Water quality sampling ER - TY - JOUR TI - Tritrophic effects of plant growth regulators in an aphid-parasitoid system AU - Prado, Sara G. AU - Frank, Steven D. T2 - BIOLOGICAL CONTROL AB - Plant growth regulators (PGRs) have the potential to negatively affect the outcome of biological control via plant architectural changes and plant chemical changes. Despite studies demonstrating the negative effects of PGRs on herbivore survival and development, to date, no studies have investigated the tritrophic effects of PGRs on parasitoid life history traits. In this study we investigated the effect of four commonly used PGRs on Myzus persicae abundance and suppression, and Aphidius colemani fitness in a greenhouse experiment. None of the PGRs reduced aphid abundance alone or affected aphid suppression by A. colemani. However, paclobutrazol reduced the number of mummies that developed on plants. PGRs had a range of negative effects on parasitoid fitness. No adult parasitoids eclosed from mummies on ancymidol treated plants. Paclobutrazol reduced parasitoid size, and paclobutrazol and uniconazole reduced female:total ratio. This study shows that PGRs can negatively affect parasitoid fitness, and reduce parasitism, suggesting the potential for negative long-term effects on the efficacy of biological control. DA - 2013/7// PY - 2013/7// DO - 10.1016/j.biocontrol.2013.03.019 VL - 66 IS - 1 SP - 72-76 SN - 1090-2112 KW - Aphidius colemani KW - Biological control KW - Fitness KW - Myzus persicae KW - Percent emergence KW - Sex ratio KW - Size ER - TY - JOUR TI - The national air emissions monitoring study's southeast layer site: Part iv. Effects of farm management AU - Li, Q.-F. AU - Wang-Li, L. AU - Bogan, B.W. AU - Wang, K. AU - Chai, L. AU - Ni, J.-Q. AU - Heber, A.J. T2 - Transactions of the ASABE AB - <italic>Abstract.</italic> The effects of house lighting, forced molting, manure removal, and flock replacement on air pollutant concentrations and emissions from high-rise tunnel-ventilated layer houses were evaluated. Air pollutants included ammonia (NH3), carbon dioxide (CO2), and particulate matter (PM, including PM10, PM2.5, and total suspended particulate, TSP). Emission rates were determined based on ventilation rates and pollutant concentrations, which were monitored for two years. House lighting schedules, molting, manure removal, and flock replacement activities were documented by the producer. Hen activity was monitored continuously using commercial motion detectors and was observed to be much higher during light periods as compared with dark periods. The TSP and PM10 emissions during light periods were about five times greater than during dark periods, whereas NH3 and CO2 emissions during light periods were about 20% higher. The NH3 and CO2 concentrations and emission rates decreased during molting and then increased afterward. Ammonia emission was directly proportional to hen body weight and feed consumption. Compared with NH3, CO2 concentrations and emissions showed more variations during molting. During manure pit cleanouts, NH3 and CO2 emissions decreased from 0.62 to 0.21 g d-1 hen-1 and from 78 to 64 g d-1 hen-1, respectively. After the manure pits were emptied, NH3 and CO2 emissions increased steadily during the first 3 to 7 d of manure accumulation and then remained relatively constant. Manure pit cleanout activities caused high PM emission. Particulate matter emission decreased gradually after the pits were cleaned. No significant changes in egg production, mortality, water consumption, or feed consumption were observed during manure removals. When compared with occupied houses, empty house emission rates of PM10, TSP, and NH3 each decreased by more than 90%, and CO2 decreased by more than 70%. DA - 2013/// PY - 2013/// DO - 10.13031/trans.56.9674 VL - 56 IS - 3 SP - 1199-1209 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84884185668&partnerID=MN8TOARS ER - TY - JOUR TI - The national air emissions monitoring study's Southeast Layer Site: Part III. Ammonia concentrations and emissions AU - Wang-Li, L. AU - Li, Q.-F. AU - Chai, L. AU - Cortus, E.L. AU - Wang, K. AU - Kilic, I. AU - Bogan, B.W. AU - Ni, J.-Q. AU - Heber, A.J. T2 - Transactions of the ASABE AB - <italic>Abstract.</italic> This article reports two years of quality-assured measurements of concentrations and baseline emissions of ammonia (NH3) at two tunnel-ventilated high-rise houses (houses 3 and 4) located at an egg production facility in North Carolina. The study was conducted as part of the National Air Emissions Monitoring Study (NAEMS). The inside NH3 concentrations, as represented by the exhaust air, were characterized by significant diurnal and seasonal variations. The lowest exhaust concentrations (17.0 ±14.0 ppm in house 3; 15.8 ±13.0 ppm in house 4) were observed in early afternoon (i.e., 2:00 p.m. to 3:00 p.m.) at the maximum diurnal ventilation rate. The highest concentrations (29.5 ±22.7 ppm in house 3; 28.8 ±22.2 ppm in house 4) occurred in early morning (i.e., 2:00 a.m. to 3:00 a.m.) when the ventilation rate was the lowest. Similarly, the concentrations were lowest during summer and maximum ventilation rates, and highest during winter and minimum ventilation rates. The average NH3 concentrations were 0.7, 22.9, and 20.7 ppm for inlet air and the exhausts of houses 3 and 4, respectively. The average daily mean NH3 emission rate of house 3 (fully occupied and active) was 0.599 ±0.200 g d-1 hen-1 (197 ±66.3 g d-1 AU-1, 18.2 ±6.04 g d-1 m-2) at an average ambient temperature of 16.7°C and that of house 4 was 0.600 ±0.250 g d-1 hen-1 (197 ±82.3 g d-1 AU-1, 18.2 ±7.53 g d-1 m-2) at an average ambient temperature of 16.3°C. Ammonia emission rates exhibited less daily and seasonal variation than inside NH3 concentrations. Slightly elevated NH3 emission rates were observed in early afternoon (12:00 noon to 2:00 p.m.), when house temperatures were relatively high. No significant differences in emissions between summer and winter were observed. Factors significantly affecting hen-specific NH3 emissions included house ventilation rate, ambient and exhaust air temperatures, exhaust air humidity ratio, hen population, hen activity, feed and water consumption rates, and manure accumulation time. Among all these factors, house exhaust temperature had the greatest effect on NH3 emission rate, followed by manure accumulation time. DA - 2013/// PY - 2013/// DO - 10.13031/trans.56.9673 VL - 56 IS - 3 SP - 1185-1197 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84884174071&partnerID=MN8TOARS ER - TY - JOUR TI - The national air emissions monitoring study's Southeast Layer Site: Part II. Particulate matter AU - Li, Q.-F. AU - Wang-Li, L. AU - Wang, K. AU - Chai, L. AU - Cortus, E.L. AU - Kilic, I. AU - Bogan, B.W. AU - Ni, J.-Q. AU - Heber, A.J. T2 - Transactions of the ASABE AB - <italic>Abstract. </italic> The National Air Emissions Monitoring Study (NAEMS) was established by the U.S. EPA and the U.S. livestock and poultry industries to address the lack of scientific air emission data needed for properly assessing compliance with federal air laws and regulations. A North Carolina egg layer farm (NC2B) was one of 20 NAEMS monitored farms. Emission rates of particulate matter (PM2.5, PM10, and TSP) from two high-rise layer houses at NC2B were determined based on continuous measurements of PM concentrations and house ventilation rates over a two-year period. The overall average PM2.5 emission rate of both houses combined was 0.37 ±3.06 mg d-1 hen-1 with no significant difference between houses. The average PM10 emission rates were 16.2 ±13.7 and 19.3 ±15.9 mg d-1 hen-1 from houses 3 and 4, respectively, and 17.8 ±14.9 mg d-1 hen-1 for both houses combined. The average TSP emission rates were 39.1 ±32.8 and 47.1 ±37.6 mg d-1 hen-1 for houses 3 and 4, respectively, and 43.1 ±35.5 mg d-1 hen-1 for both houses combined. The median hourly mean emission rates were 0.61, 14.7, and 31.7 mg d-1 hen-1 from house 3 and 0.72, 17.1, and 42.4 mg d-1 hen-1 from house 4 for PM2.5, PM10, and TSP, respectively. Significant temporal variations in PM concentrations and emissions were observed. Significant differences in PM concentrations were also observed between the manure pit and layer room. The PM emissions exhibited significant correlations with hen activity and house exhaust air temperature. An empirical PM emissions model was developed based on multiple regression analysis to predict PM emissions from this monitoring site. DA - 2013/// PY - 2013/// DO - 10.13031/trans.56.9571 VL - 56 IS - 3 SP - 1173-1184 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84884188730&partnerID=MN8TOARS ER - TY - JOUR TI - The national air emissions monitoring study's Southeast Layer Site: Part I. Site characteristics and monitoring methodology AU - Wang-Li, L. AU - Li, Q.-F. AU - Wang, K. AU - Bogan, B.W. AU - Ni, J.-Q. AU - Cortus, E.L. AU - Heber, A.J. T2 - Transactions of the ASABE AB - Abstract. Air emissions from animal feeding operation (AFO) facilities have been of increasing concern. While the EPA was pressured to put more stringent regulations on the AFO industry, there was an absence of suitable emission data to support regulatory decisions for different AFOs due to limitations of past studies and the absence of standard measurement protocols that link an emission rate to the different activities responsible for the emissions. In 2005, the EPA announced the AFO Air Quality Compliance Agreement, under which a two-year National Air Emissions Monitoring Study (NAEMS) was initiated. The NAEMS Southeast Layer Site was designed to collect baseline air emissions from high-rise tunnel-ventilated layer houses. The target emissions at this site were ammonia (NH 3 ), hydrogen sulfide (H 2 S), carbon dioxide (CO 2 ), volatile organic compounds (VOCs), and particulate matter (PM), including PM 2.5 , PM 10 , and total suspended particulate (TSP). In addition, operational and environmental variables (e.g., animal activity, room temperature and relative humidity (RH), house ventilation rate, ambient temperature and RH, wind speed and direction, and solar radiation) were monitored to address their impacts on the emissions. Information about house inventory and major farm management activities was also collected. This article documents site characteristics and monitoring methods for the NAEMS at the Southeast Layer Site. Baseline emissions of PM and gaseous pollutants, house ventilation rates, and apparent impacts of farm management activities are reported in parts II through VI of this series. DA - 2013/// PY - 2013/// DO - 10.13031/trans.56.9570 VL - 56 IS - 3 SP - 1157-1161 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84884184545&partnerID=MN8TOARS ER - TY - CONF TI - Techniques for characterization of particulate matter emitted from animal feeding operations AU - Lingjuan, W. L. C2 - 2013/// C3 - Evaluating veterinary pharmaceutical behavior in the environment DA - 2013/// VL - 1126 SP - 15-39 ER - TY - JOUR TI - Producing biodiesel from cottonseed oil using Rhizopus oryzae ATCC #34612 whole cell biocatalysts: Culture media and cultivation period optimization AU - Athalye, Sneha AU - Sharma-Shivappa, Ratna AU - Peretti, Steven AU - Kolar, Praveen AU - Davis, Jack P. T2 - Energy for Sustainable Development AB - The effect of culture medium composition and cultivation time on biodiesel production by Rhizopus oryzae ATCC #34612 whole cell catalysts, immobilized on novel rigid polyethylene biomass supports, was investigated. Supplementation of the medium with carbon sources led to higher lipase activity and increased the biomass immobilized on the BSPs. Statistical analysis indicates that a cultivation period of 72 h in a basal medium supplemented with both cottonseed oil and glucose is optimal for biodiesel production by R. oryzae, resulting in a fatty acid methyl ester (FAME) yield of 27.9 wt.% (228.2 g/L). DA - 2013/8// PY - 2013/8// DO - 10.1016/j.esd.2013.03.009 VL - 17 IS - 4 SP - 331-336 J2 - Energy for Sustainable Development LA - en OP - SN - 0973-0826 UR - http://dx.doi.org/10.1016/J.ESD.2013.03.009 DB - Crossref KW - Rhizopus oryzae KW - Biodiesel KW - Cottonseed oil KW - Whole cell biocatalysts KW - Fungal catalysis ER - TY - JOUR TI - Impact of biochar application on nitrogen nutrition of rice, greenhouse-gas emissions and soil organic carbon dynamics in two paddy soils of China AU - Xie, Zubin AU - Xu, Yanping AU - Liu, Gang AU - Liu, Qi AU - Zhu, Jianguo AU - Tu, Cong AU - Amonette, James E. AU - Cadisch, Georg AU - Yong, Jean W. H. AU - Hu, Shuijin T2 - PLANT AND SOIL DA - 2013/9// PY - 2013/9// DO - 10.1007/s11104-013-1636-x VL - 370 IS - 1-2 SP - 527-540 SN - 1573-5036 KW - Biochar KW - Greenhouse gases KW - Carbon sequestration KW - Nitrogen use efficiency KW - Rice ER - TY - JOUR TI - Defining predevelopment hydrology to mimic predevelopment water quality in stormwater control measures (SCMs) AU - Cizek, Adrienne R. AU - Hunt, William F. T2 - ECOLOGICAL ENGINEERING AB - As part of Low Impact Development, stormwater control measures (SCMs) are expected to mimic pre-development hydrology. This generally results in a comparison between outflow volumes discharged from SCMs and a target condition annual runoff. Such a simplistic evaluation overlooks multiple pathways of water present in target watersheds and SCMs, namely shallow interflow and groundwater surge. This discussion suggests a more refined means of evaluating cognate conditions for SCMs in terms of hydrology and effluent water quality by discretizing SCM discharge into three pathways: runoff, shallow interflow, and groundwater surge. Preliminary evidence using deuterium isotopes from bioretention outflow supports this concept, and future research routes are suggested. DA - 2013/8// PY - 2013/8// DO - 10.1016/j.ecoleng.2013.04.016 VL - 57 SP - 40-45 SN - 1872-6992 KW - Stormwater KW - Predevelopment hydrology KW - Low impact development ER - TY - JOUR TI - An evaluation of solid waste capture from recirculating aquaculture systems using a geotextile bag system with a flocculant-aid AU - Guerdat, Todd C. AU - Losordo, Thomas M. AU - DeLong, Dennis P. AU - Jones, Richard D. T2 - AQUACULTURAL ENGINEERING AB - Two separate geotextile bag systems were evaluated as a means for capturing and dewatering bio-solids in the effluent stream from recirculating aquaculture systems (RAS). Each geotextile bag system used a high molecular weight cationic polyacrylamide (PAM) polymer as a flocculant-aid. The two systems were operated under freshwater and brackish water conditions. A complete analysis including water quality and agronomic sludge analysis was conducted at the North Carolina State University Fish Barn – a large-scale, freshwater RAS demonstration and growout facility. An evaluation of water quality and performance of a similar geotextile bag system was also conducted at the Marine Aquaculture Research Center near Marshallberg, North Carolina, USA, under brackish conditions (15 PPT). Results indicated that performance of each of the systems was similar with TSS, COD, TN, and TP removal greater than 95%, 65%, 50%, and 38%, respectively, for both systems. Analysis of the sludge collected in the freshwater system after 70 days in a dewatering, inactive mode, showed a moisture content (MC) of 86%, or 14% dry matter (DM), indicating the system was effective at passively dewatering the bio-solids. Nutrient removal efficiency may be system specific based on the geotextile bag size and influent flow rate. Geotextile bag systems using flocculant-aids are an efficient means for capturing and dewatering waste solids from RAS effluents. Optimized geotextile bag system designs depend on flow rate, feed rate, and solids dewatering time, and fate of the treated effluent. This evaluation will aid in predicting the expected performance and determining the appropriate size of a geotextile bag system. The type of treatment required downstream from the geotextile bag system used for solids capture in a RAS wastewater treatment system will depend on the intended fate of the treated effluent. DA - 2013/5// PY - 2013/5// DO - 10.1016/j.aquaeng.2012.10.001 VL - 54 SP - 1-8 SN - 0144-8609 KW - Geotextile bag KW - Recirculating aquaculture systems KW - Solids capture KW - Flocculant aid KW - Wastewater treatment ER - TY - JOUR TI - Species-specific escape behaviour in grasshoppers AU - Butler, Eric M. T2 - BEHAVIOUR AB - A number of vertebrate species have been shown to flee at species-specific distances when approached by a predator but data on invertebrate escape behaviour are few. Grasshoppers are visually-orienting invertebrates that switch between walking when undisturbed to flying or jumping to flee from predators, thereby allowing the beginning and end of an escape attempt to be clearly defined. I studied the approach distances, escape distances, and angles of escape of nine sympatric species of acridid grasshoppers. Both approach distance and escape distance were correlated with each other and differed among species. Angle of escape showed no discernible trends. Within species some variation in escape behaviour was seen among sexes and colour morphs. The variation in escape behaviour among species was correlated with phylogeny but not with body size. DA - 2013/// PY - 2013/// DO - 10.1163/1568539x-00003108 VL - 150 IS - 13 SP - 1531-1552 SN - 0005-7959 KW - escape behaviour KW - defensive behaviour KW - grasshoppers ER - TY - JOUR TI - Interactive irrigation tool for simulating smart irrigation technologies in lawn turf AU - Dobbs, N. A. AU - Migliaccio, K. W. AU - Dukes, M. D. AU - Morgan, K. T. AU - Li, Y. C. T2 - Journal of Irrigation and Drainage Engineering DA - 2013/// PY - 2013/// VL - 139 IS - 9 SP - 747-754 ER - TY - JOUR TI - Induction of lipids and resultant FAME profiles of microalgae from coastal waters of Pearl River Delta AU - Daroch, Maurycy AU - Shao, Congcong AU - Liu, Ying AU - Geng, Shu AU - Cheng, Jay J. T2 - BIORESOURCE TECHNOLOGY AB - This article presents a study on identification, cultivation and characterisation of microalgal strains from the coastal waters of the Pearl River Delta in Guangdong, China. Thirty-seven identified strains belong to the families: Chlorellaceae, Scotiellocystoidaceae, Scenedesmaceae,Selenastraceae,Micractiniaceae, Coccomyxaceae, Trebouxiaceae and Chlorococcaceae. Of isolated strains, Hindakia PKUAC 169 was selected for lipid induction using two methods: nitrogen starvation and salt stress. After derivatisation of algal lipids through in situ transesterification, lipid profiles of the alga under the two methods were analysed. The results have shown that both lipid yield and fatty acid profiles vary with the methods. Of the two tested methods of inducing lipid production, salt stress yielded three-fold higher lipid productivity than nitrogen starvation. The lipids are predominantly composed of C14-C18 fatty acids, which are favourable for biodiesel production. Moreover, the content of polyunsaturated fatty acids was below the limit of 12% set by EN14214 biodiesel standard. DA - 2013/10// PY - 2013/10// DO - 10.1016/j.biortech.2013.07.048 VL - 146 SP - 192-199 SN - 1873-2976 KW - Microalgae KW - Diversity KW - Cultivation KW - Oil accumulation KW - Algal biodiesel ER - TY - JOUR TI - Comparison of the performances of DRAINMOD-NII and ADAPT models in simulating nitrate losses from subsurface drainage systems AU - Ale, Srinivasulu AU - Gowda, Prasanna H. AU - Mulla, David J. AU - Moriasi, Daniel N. AU - Youssef, Mohamed A. T2 - AGRICULTURAL WATER MANAGEMENT AB - Adequate knowledge on the movement of nitrate-nitrogen (NO3-N) under different subsurface (tile) drain configurations and management practices in the U.S. Midwest is essential for developing remedial measures for reducing hypoxic conditions in the Gulf of Mexico. In this study, DRAINMOD-NII, a daily time-step soil carbon (C) and N model, was calibrated and validated for subsurface drainage and associated NO3-N losses, and crop yield. Long term (1983–1996) monitoring data measured on three experimental plots under continuous corn (Zea mays L.) with conventional tillage practice at the University of Minnesota's Southern Research and Outreach Center near Waseca, southern Minnesota was used for this purpose. Nash-Sutcliffe efficiency (NSE), Percent Error (PE) and Index of agreement (d) were used for assessing the model performance. DRAINMOD-NII predicted monthly subsurface drainage matched well with measured data during calibration (NSE = 0.81, PE = −7.8% and d = 0.94) and validation (NSE = 0.67, PE = −0.7% and d = 0.88) periods. Performance of DRAINMOD-NII for predicting monthly NO3-N losses in subsurface drainage was also good for both calibration (NSE = 0.64, PE = 0.8%, and d = 0.85) and validation (NSE = 0.62, PE = −5.3%, and d = 0.83) periods. DRAINMOD-NII predicted average (1983–1992) annual corn relative yield (93%), a ratio of crop yield in a year to the long-term average crop yield, was close to the observed relative yield (92.5%). DRAINMOD-NII simulation results were also compared and contrasted with those obtained by the Agricultural Drainage and Pesticide Transport (ADAPT) model with the same dataset. Both models performed equally well in predicting monthly subsurface drainage. However, DRAINMOD-NII performed slightly better in predicting monthly NO3-N losses and annual N budget, in addition to showing potential to simulate the effects of excess and deficit water stresses on crop yield. Studies comparing performances of different drainage models in the U.S. Midwest are useful to select an appropriate model for devising various strategies for reducing NO3-N losses from subsurface drainage systems, and thereby minimizing hypoxic conditions in the Gulf of Mexico. DA - 2013/11// PY - 2013/11// DO - 10.1016/j.agwat.2013.07.008 VL - 129 SP - 21-30 SN - 1873-2283 KW - DRAINMOD KW - Hydrology KW - Nitrate losses KW - Tile drainage KW - Water quality ER - TY - JOUR TI - Application of an integrated framework for estimating nitrate loads from a coastal watershed in south-east Sweden AU - Salazar, Osvaldo AU - Wesstrom, Ingrid AU - Joel, Abraham AU - Youssef, Mohamed A. T2 - AGRICULTURAL WATER MANAGEMENT AB - Nitrate-nitrogen (NO3-N) loading from a 734 ha coastal watershed draining into the Baltic Sea off south-east Sweden was simulated using a simple modelling approach in which the nitrogen model DRAINMOD-N II and a temperature-dependent NO3-N removal equation were incorporated into the Arc Hydro-DRAINMOD framework. Hydrology and water quality data collected during six periods between 2003 and 2007 were used to test Arc Hydro-DRAINMOD and its performance was evaluated by considering uncertainty in model parameters using GLUE methodology. The GLUE estimates (5th and 95th percentiles) and calculated monthly NO3-N loads were in satisfactory agreement. There are some sources of errors that may affect the performance of the framework, such as NO3-N load calculations, soil denitrification and in-stream removal of NO3-N. Although additional measurements may help to improve the understanding of these processes and reduce uncertainty, they cannot completely eliminate the uncertainty in framework predictions. These uncertainties must be evaluated by some methodology, such as the GLUE procedure. Sensitivity analysis showed the framework to be most sensitive to changes in stream baseflow and N removal processes in the stream network. These results show that the Arc Hydro-DRAINMOD framework can be an effective tool to support water stakeholders in managing NO3-N loading from small tile-drained watersheds at monthly time step. DA - 2013/11// PY - 2013/11// DO - 10.1016/j.agwat.2013.07.020 VL - 129 SP - 56-68 SN - 1873-2283 KW - Distributed model KW - Hydrological modelling KW - Non-point pollution KW - Parameter calibration KW - Prediction uncertainty KW - Water quality ER - TY - JOUR TI - Advancing water resource management in agricultural, rural, and urbanizing watersheds: Why land-grant universities matter AU - Gold, A. J. AU - Parker, D. AU - Waskom, R. M. AU - Dobrowolski, J. AU - M. O'Neill, AU - Groffman, P. M. AU - Addy, K. AU - Barber, M. AU - Batie, S. AU - Benham, B. AU - Bianchi, M. AU - Blewett, T. AU - Evensen, C. AU - Farrell-Poe, K. AU - Gardner, C. AU - Graham, W. AU - Harrison, J. AU - Harter, T. AU - Kushner, J. AU - Lowrance, R. AU - Lund, J. AU - Mahler, R. AU - McClaran, M. AU - McFarland, M. AU - Osmond, D. AU - Pritchett, J. AU - Prokopy, L. AU - Rock, C. AU - Shober, A. AU - Silitonga, M. AU - Swackhather, D. AU - Thurston, J. AU - Todey, D. AU - Turco, R. AU - Vellidis, G. AU - Morton, L. Wright T2 - JOURNAL OF SOIL AND WATER CONSERVATION AB - Federally funded university water programs have had limited success in halting the degradation of water resources in agricultural, rural, and urbanizing watersheds for the past five decades.USDA-funded university water programs have advanced our understanding of watershed processes and the development of best management practices (BMPs; e.g., conservation tillage, nutrient management, alternative and innovative septic systems, and riparian buffers) to mitigate environmental risks from anthropogenic activities, in particular from agriculture, to our water resources; yet water degradation persists and has worsened in many watersheds (Howarth et al. 2000;Mueller and Spahr 2006).The National Research Council (2012) stresses the need for sustainable agricultural practices to reduce changes in flow regimes and water quality.In this research editorial, we make four points relative to solving water resource issues: (1) they are complex problems and difficult to solve; (2) some progress has been made on solving these issues; (3) external nonstationary drivers such as land use changes, climate change and variability, and shifts in markets, policies, and regulations warrant constant vigilance to assure that presumed improvements are being attained; and (4) we are poised to make substantial progress on these challenges over the next 10 to 20 years if critical steps are taken.Our discussion is framed by identifying and describing four grand challenges that we face in agricultural, rural, and urbanizing watersheds: nutrient management, food DA - 2013/// PY - 2013/// DO - 10.2489/jswc.68.4.337 VL - 68 IS - 4 SP - 337-348 SN - 1941-3300 ER - TY - JOUR TI - The impact of manipulating surface topography on the hydrologic restoration of a forested coastal wetland AU - Jarzemsky, Robert D. AU - Burchell, Michael R., II AU - Evans, Robert O. T2 - ECOLOGICAL ENGINEERING AB - A wetland, converted to agriculture in the mid-1970s, was restored to re-establish a non-riverine wet hardwood forest community in eastern North Carolina. Three surface techniques were implemented during construction to determine their effect on successfully restoring target wetland hydrology. The surface treatments, replicated within a randomized complete block design, were: plugging field ditches without altering the land surface (PLUG), plugging the field ditches and roughening the surface (ROUGH), and plugging the field ditches and removing the field crown (CR). Hydrologic conditions for the restoration and a nearby reference site were evaluated based on three years of monitoring data. Daily water table depths between the restoration and reference were within 11 cm on average. An initial evaluation found inconsistencies of treatment effect between blocks, and an as-built survey later confirmed surface elevations within Block 3 deviated from the intended design and was excluded from further analysis. Water table and outflow conditions for the remaining treatment plots and the reference were evaluated using several hydrologic criteria. The CR treatment was found to produce the wettest surface conditions and exported the lowest volume of outflow. For the majority of criterion considered, CR also produced significantly wetter conditions than the reference. The PLUG and ROUGH treatments produced similar hydrologic conditions and tracked closely with the median hydrologic conditions in the reference. Based on the results of this study and several others in low lying coastal areas, plugging pre-existing field ditches may be adequate to restore jurisdictional wetland hydrology and match reference hydrologic conditions. However, surface roughening is low cost method to increase surface storage and introduce microtopographic diversity. For many areas, the removal of existing field crown may be cost-prohibitive and produce wetter than desired conditions. Crown removal should be reserved for sites which have borderline historic wetland hydrologic characteristics. DA - 2013/9// PY - 2013/9// DO - 10.1016/j.ecoleng.2013.06.002 VL - 58 SP - 35-43 SN - 1872-6992 KW - Wetland hydrology KW - Restoration KW - Microtopography ER - TY - JOUR TI - Predicting the carbon footprint of urban stormwater infrastructure AU - Moore, Trisha L. C. AU - Hunt, William F. T2 - ECOLOGICAL ENGINEERING AB - Due to increased regulations concerning urban stormwater runoff, stormwater control measures (SCMs) such as bioretention, ponds, and constructed stormwater wetlands, are becoming a more common feature of urban and periurban landscapes. The water quality and hydrologic benefits of SCMs are generally well-documented, and planning tools are available to optimize water quality benefits with economic costs of SCM construction and maintenance. Given rising interest in and potential for regulation of carbon emissions, a planning tool that allows for estimation of carbon emissions associated with SCM construction and maintenance is also a relevant pursuit. The objective of this work was to present a framework by which carbon emissions attributable to SCMs and conveyances could be predicted. This method was then applied to present a comparison of the carbon footprint of eight common SCMs and three stormwater conveyance types. The carbon embodied in construction materials represented a prominent part of the carbon footprint for green roofs, permeable pavement, sand filters, rainwater harvesting systems, and reinforced concrete pipes while material transport and construction dominated that of bioretention systems, ponds, wetlands, level spreader-grassed filter strips and concrete-lined swales. Despite accounting for sequestration by vegetation in these systems, only stormwater wetlands and grassed swales were predicted to store more carbon than what was released through construction and maintenance. DA - 2013/9// PY - 2013/9// DO - 10.1016/j.ecoleng.2013.06.021 VL - 58 SP - 44-51 SN - 1872-6992 KW - Carbon KW - Stormwater KW - BMPs KW - SCMs KW - Carbon sequestration KW - Carbon footprint KW - Carbon emissions KW - Stormwater wetlands KW - Bioretention KW - Swales ER - TY - JOUR TI - Nitrogen mass balance in commercial roaster houses receiving different acidifier application rates AU - Shah, S. B. AU - Grimes, J. L. AU - Oviedo-Rondon, E. O. AU - Westerman, P. W. AU - Campeau, D. T2 - JOURNAL OF APPLIED POULTRY RESEARCH AB - Broiler production has the potential to cause water and air pollution. Acidifiers such as sodium bisulfate (SBS) can reduce ammonia (NH3) emissions from broiler houses; NH3 is an important air pollutant that also affects bird health. Due to their longer grow-outs, roasters may require higher acidifier application rates to prevent unhealthy NH3 levels during the flock than ordinary broilers. Changes in NH3 emission with acidifier use may affect the partitioning of the input nitrogen (N) among the different N output pathways. Accounting for these output pathways through N mass balance provides a complete picture of N as it cycles through the roaster house. In a 2-yr study involving 9 flocks of roasters, 4 levels of SBS were applied to the litter in commercial roaster houses. Whereas the control treatment received up to 0.49 kg/m2 to the brood chamber, the high, medium, and low treatments received up to 1.46, 0.73, and 0.49 kg/m2, respectively, to the whole house. Ammonia-N emission decreased and N removed in cake and litter increased with SBS application rate. Nitrogen output components were averaged over the 4 treatments and expressed as percent of total N input or per unit mass of live weight (LW). Ammonia-N emission during grow-out, bird N exported, and cake and litter N removed accounted for 17.3% or 11.2 g/kg of LW, 38.9% or 25.1 g/kg of LW, and 22.4% or 14.4 g/kg of LW, respectively. We accounted for 79.1% of the total N inputs, with NH3-N losses during layout probably constituting the bulk of the unaccounted N. In addition to uncertainties in measurements of inputs and outputs, other factors that limited the ability to close the N mass balance were exclusion of feathers during cake and litter sampling, soil N leaching, and nitrous oxide emissions. DA - 2013/9// PY - 2013/9// DO - 10.3382/japr.2012-00704 VL - 22 IS - 3 SP - 539-550 SN - 1537-0437 KW - ammonia emission KW - cake KW - litter KW - feed KW - tissue KW - sodium bisulfate ER - TY - JOUR TI - In vitro biomechanical comparison of the flexion/extension mobility of the canine lumbosacral junction before and after dorsal laminectomy and partial discectomy AU - Early, P. AU - Mente, P. AU - Dillard, S. AU - Roe, S. T2 - VETERINARY JOURNAL AB - The purpose of this canine cadaver study was to evaluate the range of flexion and extension of the canine lumbosacral spine before and after dorsal laminectomy and partial discectomy. Using a cantilever biomechanical system, a 3 Nm bending moment was applied to flex and extend the lumbosacral segment. Motion in L7 (total range of motion [ROM] and neutral zone motion [NZ]) was recorded via a rotational potentiometer. There was a significant increase in NZ and ROM after the decompressive procedures (NZ before decompression 6.0 ± 1.2°; NZ after decompression 7.6 ± 2.1°; ROM before decompression 32.8 ± 6.4°; ROM after decompression 40.2 ± 5.6°). It is unknown whether dorsal laminectomy and partial discectomy will induce the same increased motion in clinical cases. Dogs with lumbosacral subluxation, active dogs with little radiographic degenerative changes and working dogs could benefit from lumbosacral stabilization. This cadaver study demonstrated that dorsal laminectomy and partial discectomy at the lumbosacral junction does lead to significant spinal instability. DA - 2013/6// PY - 2013/6// DO - 10.1016/j.tvjl.2012.11.006 VL - 196 IS - 3 SP - 533-535 SN - 1090-0233 KW - Lumbosacral KW - Biomechanics KW - Dog KW - Intervertebral disc KW - Laminectomy ER - TY - JOUR TI - Effect of physical and inhaled euthanasia methods on hormonal measures of stress in pigs AU - Meyer, R. E. AU - Whitley, J. T. AU - Morrow, W. E. M. AU - Stikeleather, L. F. AU - Baird, C. L. AU - Rice, J. M. AU - Halbert, B. V. AU - Styles, D. K. AU - Whisnant, C. S. T2 - Journal of Swine Health and Production DA - 2013/// PY - 2013/// VL - 21 IS - 5 SP - 261-269 ER - TY - JOUR TI - Ancillary effects of different acidifier application rates in roaster houses AU - Shah, S. B. AU - Westerman, P. W. AU - Grimes, J. L. AU - Oviedo-Rondon, E. O. AU - Campeau, D. T2 - JOURNAL OF APPLIED POULTRY RESEARCH AB - High ammonia levels in broiler houses can reduce bird performance. Broiler producers commonly use acidifiers to reduce ammonia build-up. In addition to improving broiler performance, acidifiers can also provide other ancillary benefits such as reducing propane and electricity use and increasing cake (caked litter) N content. In this 2-yr study involving 9 flocks, 4 levels of an acidifier (sodium bisulfate) were applied to commercial roaster houses in eastern North Carolina. The control treatment had a sodium bisulfate application rate of up to 0.1 lb/ft2 to the brood chamber, whereas the high, medium, and low treatments had application rates of up to 0.3, 0.15, and 0.1 lb/ft2, respectively, to the whole house. No treatment effect was observed on propane or electricity use. However, compared with published studies involving smaller broilers, roasters required lesser amounts of propane and electricity. Linear regressions of propane and electricity use as a function of ambient temperature may help with decision making in roaster production. Brooding accounted for 88% of propane consumption. Reduced pH in the high treatment compared with the other treatments led to significantly higher ammonium concentration in the cake. DA - 2013/9// PY - 2013/9// DO - 10.3382/japr.2012-00693 VL - 22 IS - 3 SP - 565-573 SN - 1537-0437 KW - propane KW - electricity KW - ammonia KW - nitrogen KW - fertilizer value KW - sodium bisulfate ER - TY - JOUR TI - Acidifier dosage effects on inside ammonia concentrations in roaster houses AU - Shah, Sanjay AU - Oviedo-Rondon, E. O. AU - Grimes, J. L. AU - Westerman, P. W. AU - Campeau, D. T2 - Applied Engineering in Agriculture AB - <italic>Abstract. </italic> Ammonia (NH3) in broiler houses can degrade bird performance. Acidifier such as, sodium bisulfate (SBS) applied to litter inside broiler houses can reduce NH3 release and thus improve bird performance. While there are multiple studies on acidifier effects on inside NH3 concentrations in broiler houses, there are no studies in roaster houses where big broiler birds are grown for 8 to 12 wk. The impact of different SBS application rates - High (1.46 kg/m2, whole house), Medium (0.73 kg/m2, whole house), Low (0.49 kg/m2, whole house), and Control (0.49 kg/m2, brood chamber) on inside NH3 concentrations was evaluated over six flocks of roaster chickens (~4 kg ea.). Ammonia concentrations were measured with acid scrubbers that sampled air at two locations (mid-house, end-house) 0.15 m above the litter. Inside NH3 concentrations were much higher in the cool-season versus warm-season flocks. Generally, higher acidifier application rates provided better NH3 suppression. Ammonia concentrations were ≤10 ppm during brooding, as well as for the entire duration of most warm-weather flocks with the High and Medium treatments. In the Low treatment, NH3 concentrations were ≤25 ppm during brooding but approached or exceeded 25 ppm with the Control treatment. During brooding, the High, Medium, and Low treatments resulted in significantly lower mid-house NH3 concentrations of 3, 6, and 14 ppm, respectively, versus the Control treatment (24 ppm). For a 62-d flock, mid-house NH3 concentrations were significantly lower in the High and Medium treatments versus the Control treatment; concentrations in the High, Medium, and Low treatments were reduced by 47%, 32%, and 20%, respectively, versus the Control treatment. DA - 2013/// PY - 2013/// DO - 10.13031/aea.29.9904 VL - 29 IS - 4 SP - 573–580 ER - TY - JOUR TI - Physical Properties of Gluten-Free Donuts AU - Melito, Helen AU - Farkas, Brian E. T2 - JOURNAL OF FOOD QUALITY AB - Abstract Gluten intolerance and wheat allergy are becoming more prevalent in the A merican population. Treatment for either condition is complete avoidance of wheat‐ and gluten‐containing products. Little work has been performed on gluten‐free ( GF ) fried foods, such as donuts. Thus, this study examined instrumental and sensory properties of GF yeast donuts in comparison to wheat yeast donuts. Eight different GF donut formulations were evaluated via instrumental and sensory analysis. Statistical analysis ( α = 0.05) showed that most GF donuts had significantly lower fat content (26.3–32.2%) than the wheat control (33.7%). A higher ratio of commercial GF flour to rice flour resulted in higher fat content and mechanical properties closer to those of the wheat control compared with a lower ratio. Although GF donuts had significantly lower sensory acceptance scores than wheat donuts, several formulations yielded GF donuts with similar instrumental properties and lower fat content than the wheat control. Practical Applications This work yielded a gluten‐free donut formulation that produced donuts with similar mechanical properties to wheat donuts, but with a lower fat content. These results show that gluten‐free flours may be used in combination with wheat flour to produce donuts with lower fat content without adversely affecting the mechanical properties of the donuts. In addition, a commercial gluten‐free donut product is not currently available, and this work makes strides toward a final formulation for this type of product. DA - 2013/2// PY - 2013/2// DO - 10.1111/jfq.12008 VL - 36 IS - 1 SP - 32-40 SN - 1745-4557 ER - TY - JOUR TI - Compact plants reduce biological control of Myzus persicae by Aphidius colemani AU - Prado, Sara Guiti AU - Frank, Steven D. T2 - BIOLOGICAL CONTROL AB - Common horticultural practices, such as the use of plant growth regulators, may negatively influence the outcome of biological control programs. Plant growth regulators are applied to many ornamental and agricultural crops and can result in compact plants that have more branches and are bushier than untreated plants. Since plant architectural complexity can have strong effects on natural enemy foraging efficiency and pest suppression, our hypothesis was that the use of plant growth regulators would reduce aphid suppression by the parasitoid Aphidius colemani. In this study we investigated how the plant growth regulator paclobutrazol and the parasitic wasp A. colemani interact to affect the abundance and behavior of Myzus persicae. We found that paclobutrazol alone reduced aphid abundance compared to untreated plants. However, when parasitoids were present, paclobutrazol and associated changes in plant architecture reduced parasitism and increased aphid abundance compared to untreated plants. A likely mechanism for this result is that significantly more M. persicae fed in concealed locations on paclobutrazol-treated plants than on untreated plants. This study demonstrates that paclobutrazol reduced the efficacy of biological control by A. colemani and suggests that plant growth regulators could also affect biological control of other organisms. DA - 2013/5// PY - 2013/5// DO - 10.1016/j.biocontrol.2013.03.004 VL - 65 IS - 2 SP - 184-189 SN - 1090-2112 KW - Foraging efficiency KW - Paclobutrazol KW - Plant growth regulator KW - Prey behavior ER - TY - JOUR TI - Alteration of soil hydraulic properties during the construction of mitigation wetlands in the Virginia Piedmont AU - Petru, Bradley J. AU - Ahn, Changwoo AU - Chescheir, George T2 - ECOLOGICAL ENGINEERING AB - Wetland hydrology is a critical component to the success of mitigation projects. The alteration of soil hydraulic properties during the construction may influence the hydrology of the wetland, thus affecting the mitigation success. We studied disturbed (i.e. by construction) and nondisturbed areas of two wetland mitigation banks (Blackjack, BJ and Peters Farm, PF), both located in the piedmont region of Virginia, for a variety of soil hydraulic and physicochemical properties. The surface soil horizon at BJ showed an increase in clay content from 18.6 to 40%, decrease in bulk density (Db) from 1.56 to 1.45 g/cm3, decrease the drained volume (Dv) of water in the soil profile from 0.67 to 0.36 cm, decrease in available water content (AWC) from 22.7 to 15.8%, and a reduction in the ratio of AWC to TPS from 66 to 40%. Soil at PF showed an increase in clay content in the surface horizon from 20 to 30%, increase TPS from 37.2 to 40.0%, increase Db from 1.52 to 1.67 g/cm3, increase the Dv in the soil profile from 3.5 to 6.6 cm, increase in AWC from 37.2 to 40.2%, and a decrease in the ratio of AWC to TPS from 58 to 44% in the surface horizon. The outcome showed that the impacts of common construction practices for mitigation wetlands affected drainable and plant available subsurface water storage, more so in fine grained soils. Key soil hydraulic properties should be considered in the disturbed or ameliorated state before water budgets are constructed to model wetland hydrology. Further studies are needed to investigate how the plant available and drainable water contents can be affected by construction practices in various soil textures, and how these properties might change in the long term. DA - 2013/2// PY - 2013/2// DO - 10.1016/j.ecoleng.2012.12.073 VL - 51 SP - 140-150 SN - 1872-6992 KW - Created wetlands KW - Soil disturbance KW - Wetland mitigation KW - Soil water physics KW - Water budgets KW - Plant available water KW - Drainable water ER - TY - JOUR TI - Riparian buffer located in an upland landscape position does not enhance nitrate-nitrogen removal AU - Johnson, Sara R. AU - Burchell, Michael R., II AU - Evans, Robert O. AU - Osmond, Deanna L. AU - Gilliam, J. Wendell T2 - Ecological Engineering AB - Relatively narrow (<50 m) riparian buffers strategically reestablished in correct landscape positions have been shown to significantly reduce agricultural non-point source pollution to streams. Because of this, conservation programs have been established to encourage landowners to enroll lands near surface waters to improve water quality. Former cropland enrolled in a conservation program was evaluated to determine its effectiveness in reducing nitrate-nitrogen (NO3−-N) in shallow groundwater. This conservation buffer (CB) was up to 80 m wide and was planted with loblolly pine (Pinus taeda). It was situated upslope of an existing 30–60 m wide riparian hardwood forest buffer (EHB) located within the floodplain of an intermittent stream. Shallow groundwater NO3−-N, groundwater hydrology, total organic carbon, and soil redox potential were measured throughout both the CB and the EHB for 18 months. Groundwater NO3−-N concentrations, often 5–15 mg L−1 within the CB, were not significantly reduced from concentrations that entered from the agricultural field edge. However, a decrease in NO3−-N concentration was observed within the EHB (17–83%). The hydrology of the CB coupled with relatively low organic carbon contributed to a low denitrification potential and lack of NO3−-N reduction compared with the EHB. While the CB enrollment likely provided additional habitat benefits it did not appear to provide treatment of groundwater NO3−-N. It is our conclusion that landscape position is a more important defining variable for buffer site selection than buffer width if NO3−-N reduction is a primary goal. DA - 2013/3// PY - 2013/3// DO - 10.1016/j.ecoleng.2012.11.006 VL - 52 SP - 252-261 J2 - Ecological Engineering LA - en OP - SN - 0925-8574 UR - http://dx.doi.org/10.1016/j.ecoleng.2012.11.006 DB - Crossref KW - Riparian buffer KW - Conservation programs KW - Groundwater KW - Hydrology KW - Nitrate KW - NO3--N ER - TY - JOUR TI - Long-term study of dune infiltration systems to treat coastal stormwater runoff for fecal bacteria AU - Price, W.D. AU - Burchell, M.R., II AU - Hunt, W.F. AU - Chescheir, G.M. T2 - Ecological Engineering AB - Abstract The discharge of untreated stormwater runoff into recreational waters places swimmers at risk of contracting various illnesses and often results in beach closures or swimming advisories. In an effort to safeguard the public, two experimental Dune Infiltration Systems were installed beneath the sand dunes in Kure Beach, NC. The systems diverted stormwater from two existing beach outfalls, which drained 1.9 ha (4.7 ac) and 3.2 ha (8.0 ac) watersheds, into subsurface chambers for temporary storage and infiltration into the existing sand dunes. A 3-year study examined the long-term performance of the two systems during which 14,584 m 3 (515,046 ft 3 ) of stormwater was diverted into the dunes, with only 438 m 3 (15,457 ft 3 ) bypassing the systems, a nearly 97% capture rating. Enterococci concentrations in stormwater runoff from the watersheds exceeded the state's single sample maximum for Tier I waters (104 MPN/100 mL) in >70% of samples, with geometric means ≥278 MPN/100 mL. Groundwater enterococci concentrations tended to remain below the state limit (≤11% exceedance), with geometric means ≤7 MPN/100 mL. Groundwater monitoring in the control dune, with no direct input of stormwater, had a geometric mean of 5 MPN/100 mL and a 6% exceedance rate. The influences on the local water tables were temporary, as the water table would mound around the systems during infiltration events and dissipate to within pre-storm variations from the control within hours or up to approximately 2 weeks. The Dune Infiltration System appears appropriate for installation in small watersheds ( DA - 2013/3// PY - 2013/3// DO - 10.1016/j.ecoleng.2012.12.008 VL - 52 SP - 1-11 J2 - Ecological Engineering LA - en OP - SN - 0925-8574 UR - http://dx.doi.org/10.1016/j.ecoleng.2012.12.008 DB - Crossref KW - Fecal bacteria KW - Infiltration KW - Sand filter KW - Coastal stormwater KW - Sand dunes KW - Ocean outfalls ER - TY - JOUR TI - Hydrologic Effects of Size and Location of Fields Converted from Drained Pine Forest to Agricultural Cropland AU - Kim, Hyun Woo AU - Amatya, Devendra M. AU - Chescheir, George M. AU - Skaggs, Wayne R. AU - Nettles, Jami E. T2 - JOURNAL OF HYDROLOGIC ENGINEERING AB - Hydrological effects of land-use change are of great concern to ecohydrologists and watershed managers, especially in the Atlantic coastal plain of the southeastern United States. The concern is attributable to rapid population growth and the resulting pressure to develop forested lands. Many researchers have studied these effects in various scales, with varying results. An extended watershed-scale forest hydrologic model, calibrated with 1996–2000 data, was used to evaluate long-term hydrologic effects of conversion to agriculture (corn–wheat–soybean cropland) of a 29.5-km2 intensively managed pine-forested watershed in Washington County in eastern North Carolina. Fifty years of weather data (1951–2000) from a nearby weather station were used for simulating hydrology to evaluate effects on outflows, evapotranspiration, and water table depth compared with the baseline scenario. Other simulation scenarios were created for each of five different percentages (10, 25, 50, 75, and 100%) of land-use conversion occurring at upstream and downstream locations in the pine-forest watershed. Simulations revealed that increased mean annual outflow was significant (α=0.05) only for 100% conversion from forest (261 mm) to agricultural crop (326 mm), primarily attributed to a reduction in evapotranspiration. Although high flow rates >5 mm day−1 increased from 2.3 to 2.6% (downstream) and 2.6 to 4.2% (upstream) for 25 to 50% conversion, the frequency was higher for the upstream location than the downstream. These results were attributed to a substantial decrease in soil hydraulic conductivity of one of the dominant soils in the upstream location, which is expected after land-use conversion to agriculture. As a result, predicted subsurface drainage decreased, and surface runoff increased as soil hydraulic conductivity decreased for the soil upstream. These results indicate that soil hydraulic properties resulting from land-use conversion have a greater influence on hydrologic components than the location of land use conversion. DA - 2013/5// PY - 2013/5// DO - 10.1061/(asce)he.1943-5584.0000566 VL - 18 IS - 5 SP - 552-566 SN - 1943-5584 KW - DRAINWAT KW - Land-use change KW - Soil hydraulic conductivity KW - Outflow KW - Peak flow rate KW - Evapotranspiration ER - TY - JOUR TI - Adsorbents from pine wood via K2CO3-assisted low temperature carbonization for adsorption of p-cresol AU - Das, Lalitendu AU - Kolar, Praveen AU - Classen, John J. AU - Osborne, Jason A. T2 - INDUSTRIAL CROPS AND PRODUCTS AB - A low-temperature carbonization process was evaluated to synthesize an inexpensive adsorbent from pine wood to mitigate p-cresol from aqueous system. Surface response experiments using carbonization time, impregnation ratio (IR), and carbonization temperature as variables indicated that optimum adsorbent yield and adsorption were 63.22% and 5.40 mg g−1, respectively at carbonization temperature of 266 °C, IR of 2, and carbonization time of 2 h. The equilibrium adsorption data agreed with Langmuir's model and maximum theoretical adsorption of 6.97 mg g−1 was obtained at temperature 25 °C, unadjusted pH and adsorbent dose of 10 g L−1. The kinetic analysis combined with desorption study revealed that p-cresol chemisorbed on the adsorbent surface. Additionally, adsorption of p-cresol was found to be exothermic and inhibited by presence of surface acidic oxygen groups. DA - 2013/2// PY - 2013/2// DO - 10.1016/j.indcrop.2012.12.010 VL - 45 SP - 215-222 SN - 1872-633X KW - Adsorption KW - p-Cresol KW - Pine wood KW - Kinetics KW - Isotherms KW - RSM ER - TY - JOUR TI - Water Application Efficiency and Adequacy of ET-Based and Soil Moisture-Based Irrigation Controllers for Turfgrass Irrigation AU - Grabow, G. L. AU - Ghali, I. E. AU - Huffman, R. L. AU - Miller, G. L. AU - Bowman, D. AU - Vasanth, A. T2 - JOURNAL OF IRRIGATION AND DRAINAGE ENGINEERING AB - Increasing competition for water and the desire for high-quality turfgrass require sound irrigation water management. The main objective of this study was to evaluate two types of commercially available irrigation control technologies: one based on evapotranspiration (ET) estimates and the other based on feedback from a soil-moisture sensor (SMS). Irrigation treatments were combinations of controller technology: a timer-based standard controller system (TIM), an add-on (1 set point) SMS system (SMS1), and an evapotranspiration (ET)-based system (ETB), and watering frequency: weekly, twice per week, and daily (1, 2, and 7 days per week, respectively) plus a 10th treatment of an on-demand (2 set point) SMS system (SMS2). Both irrigation efficiency and adequacy were best for the SMS2 treatment when averaged over all three years. The SMS1 treatment provided good irrigation efficiency, but irrigation adequacy suffered, most noticeably with the twice per week treatment. The ET treatment provided good irrigation adequacy, but had the poorest irrigation efficiency. SMS treatments resulted in average water savings of 39% in SMS1 treatments and 24% in the SMS2 treatment compared to the timer-based treatments, whereas the ET treatments applied 11% more water, on average, than the timer-based treatments. The weekly SMS1 treatment applied the least amount of water (10 mm week−1), whereas the twice per week ET treatment applied the most water (26 mm week−1). DA - 2013/2// PY - 2013/2// DO - 10.1061/(asce)ir.1943-4774.0000528 VL - 139 IS - 2 SP - 113-123 SN - 1943-4774 KW - Water management KW - Irrigation KW - Scheduling KW - Soil water KW - Automation ER - TY - JOUR TI - Uncertainty analysis of the recovery of hollow-fiber ultrafiltration for multiple microbe classes from water: A Bayesian approach AU - Wu, Jianyong AU - Simmons, Otto D., III AU - Sobsey, Mark D. T2 - JOURNAL OF MICROBIOLOGICAL METHODS AB - In this study, we introduce a Bayesian approach to address uncertainty of microbial recoveries from hollow-fiber ultrafilters (HFUF) and to determine any sources of uncertainty. Microbial recoveries were measured under twenty conditions, including two types of water, two types of ultrafilters, and five types of microorganisms. The probability distributions of the recoveries were approximated using Bayesian statistics with Markov chain Monte Carlo sampling after integrating the likelihood function of the recovery data and prior information about the data. Then a variance-decomposition method was used for examining influential factors on microbial recovery by HFUF. The results revealed that HFUF efficiently recovered Escherichia coli KO11, E. coli O157:H7 and bacteriophage MS2, but recoveries for Bacillus atrophaeus spores and adenovirus 41 were markedly different between source and treated waters. The uncertainty analysis indicated that the probability distributions for recoveries had dissimilar patterns under different conditions. Among these test factors, the type of microorganisms and associated interaction effects had great impacts on the recovery. To sum up, the Bayesian approach to uncertainty analysis shows advantages in evaluating the recovery of HFUF by providing its full probability distribution. DA - 2013/6// PY - 2013/6// DO - 10.1016/j.mimet.2013.03.005 VL - 93 IS - 3 SP - 161-167 SN - 1872-8359 KW - Hollow-fiber ultrafilter KW - Recovery KW - Bayesian statistics KW - Uncertainty analysis KW - Drinking water KW - Microorganisms ER - TY - JOUR TI - The capacity of roadside vegetated filter strips and swales to sequester carbon AU - Bouchard, Natalie R. AU - Osmond, Deanna L. AU - Winston, Ryan J. AU - Hunt, William F. T2 - ECOLOGICAL ENGINEERING AB - Carbon capture and storage within vegetation and soil is impacted by changing land uses, which results in either a net source or sink of greenhouse gases (GHGs) to the atmosphere. Transportation corridors are present world-wide, and the vegetated filter strip and vegetated swale (VFS/VS), a common stormwater control measure, often constitutes the right-of-way (ROW) adjacent to roadways. The roadway environment, specifically carbon pools in North Carolina highway ROWs, were studied for carbon sequestration potential, an important ecosystem service. The study was conducted in two North Carolina physiographic regions: the Piedmont (characterized by clay-influenced soils) and the Coastal Plain (predominantly sandy soils). Approximately 700 soil samples were collected in VFS/VSs and wetland swales alongside major highways and analyzed for percent total soil C (% total C) and bulk density to obtain the C density. Mean soil C densities (per unit area) were 2.55 ± 0.13 kg C m−2 (mean ± standard error, n = 160, 0.2 m sample depth) in the Piedmont and 4.14 ± 0.15 kg C m−2 (n = 160, 0.2 m depth) in Coastal Plain highway VFS/VSs. Previous studies on grasslands had similar C density values to those observed in this study; thus, grasslands could be a surrogate land use for highway VFS/VSs. A thirty-seven year soil chronosequence characterized C accumulation in Piedmont VFS/VSs. Carbon density increases showed an association with age in Piedmont VFS/VSs only, which were calculated to reach maximum C density of 3.34 kg C m−2, at age = 21.5 years. Previous studies on grasslands show similar C density and accumulation values to those observed in this study; thus, again grasslands could be a surrogate land use for highway VFS/VSs. Carbon density did not differ between dry or wetland swales, although % total C was significantly greater in wetland swales. The mean VS C density was 3.05 ± 0.13 kg C m−2 (n = 40, 0.2 m depth), while that for wetland swales was 5.04 ± 0.73 kg C m−2 (n = 44, 0.2 m depth). To promote C sequestration in the vegetated ROW, wetland swales appear preferable to dry swales. DA - 2013/5// PY - 2013/5// DO - 10.1016/j.ecoleng.2013.01.018 VL - 54 SP - 227-232 SN - 1872-6992 KW - Carbon sequestration KW - Vegetated filter strip KW - Swale KW - Highway KW - Ecosystem service KW - Stormwater control measure KW - Right-of-way KW - Transportation KW - Wetland ER - TY - JOUR TI - Side-by-side evaluation of four level spreader-vegetated filter strips and a swale in eastern North Carolina AU - Knight, E. M. P. AU - Hunt, W. F., III AU - Winston, R. J. T2 - JOURNAL OF SOIL AND WATER CONSERVATION AB - Level spreader–vegetated filter strips (LS–VFSs) and swales are versatile, low cost stormwater control measures (SCMs). The purpose of this study was to determine the runoff volume and pollutant reductions of four LS–VFSs and a swale in eastern North Carolina (NC). Two vegetated filter strips (VFSs) of 8 m long by 6 m wide (26 ft long by 20 ft wide), two VFSs of 20 m by 6 m (66 ft by 20 ft), and a trapezoidal swale with 3:1 side slopes (0.15 m [0.5 ft] bottom width and 10.4 m [34 ft] long) were constructed. One VFS of each size was amended with a mixture of sand and ViroPhos, a proprietary phosphorus (P) sorptive aggregate. Hydrologic data were collected for rainfall events during the 11-month sampling period. Influent and effluent samples were collected from select rainfall events and analyzed for concentrations of nitrogen (N) and P species, total suspended solids (TSS), cadmium (Cd), copper (Cu), and zinc (Zn). Significant runoff volume reductions averaging 36%, 59%, 42%, 57%, and 23% were found for the small and large unamended VFSs, the small and large amended VFSs, and the swale, respectively (n = 30). In general, concentrations of total nitrogen (TN) and TSS were reduced, while total phosphorus (TP) increased in nearly all treatments. The reductions in TN concentrations were significant in the amended VFSs and the swale, and TN was found to be irreducible at influent concentrations <1 mg L−1 (<1 ppm). TN load reductions in all treatments exceeded the 30% reduction credit assigned by NC, while only the amended VFSs and the swale exceeded the 35% load reduction credit assigned for TP.TN and TP load reductions were not significantly different between the VFSs and the swale. All treatments exceeded 75% TSS load reduction, far exceeding the 40% TSS removal credit that these systems receive in NC. In general, swale and VFS performance was similar in terms of TN and TP load reduction, while the VFSs significantly outperformed the swale in average volume and TSS load reduction. DA - 2013/// PY - 2013/// DO - 10.2489/jswc.68.1.60 VL - 68 IS - 1 SP - 60-72 SN - 0022-4561 KW - best management practice KW - nutrients KW - particle size distribution KW - sediment KW - stormwater KW - stormwater control measure ER - TY - JOUR TI - Predicting dissolved organic nitrogen export from a drained loblolly pine plantation AU - Tian, Shiying AU - Youssef, Mohamed A. AU - Skaggs, R. Wayne AU - Chescheir, G. M. AU - Amatya, Devendra M. T2 - WATER RESOURCES RESEARCH AB - Key Points A mechanistic model was developed to predict DON losses from terrestrial system The model accounts production, sorption, transport, leaching losses of DON The new model successfully simulated DON losses from three drained forests DA - 2013/4// PY - 2013/4// DO - 10.1002/wrcr.20157 VL - 49 IS - 4 SP - 1952-1967 SN - 1944-7973 KW - dissolved organic matter KW - modeling KW - forest ecosystems KW - leaching KW - DRAINMOD-NII KW - DRAINMOD-FOREST ER - TY - JOUR TI - Modeling Ammonium Adsorption on Broiler Litter and Cake AU - Liang, Wei-zhen AU - Shah, Sanjay B. AU - Classen, John J. AU - Sharma-Shivappa, Ratna T2 - WATER AIR AND SOIL POLLUTION DA - 2013/2// PY - 2013/2// DO - 10.1007/s11270-012-1405-0 VL - 224 IS - 2 SP - SN - 0049-6979 KW - Desorption KW - Langmuir isotherm KW - Freundlich isotherm KW - Temkin isotherm KW - Linear isotherm KW - Redlich-Peterson isotherm KW - Toth isotherm KW - Linear regression KW - Nonlinear regression KW - Error functions ER - TY - JOUR TI - Internal Water Storage Enhances Exfiltration and Thermal Load Reduction from Permeable Pavement in the North Carolina Mountains AU - Wardynski, Brad J. AU - Winston, Ryan J. AU - Hunt, William F. T2 - JOURNAL OF ENVIRONMENTAL ENGINEERING AB - Thermally-enriched stormwater runoff can negatively impact coldwater streams and their associated ecosystem services. The introduction of local and federal guidelines specifically targeting urban runoff temperature in the United States and Canada promulgate the use of practices that reduce thermal pollutant load from a catchment. Several stormwater control measures (SCM) have been shown to buffer thermal impacts to waterways by passing water through cooler subsurface media or by reducing overall discharge volume. Permeable pavement exposes stormwater to these mechanisms, which makes it a promising practice for thermal mitigation. A newly constructed permeable interlocking concrete paver (PICP) parking lot was monitored for 1 year in the mountain region of North Carolina to quantify runoff reduction, temperature buffering, and thermal load export. The effects on hydrology caused by internal water storage (IWS) in the pavement profile were also investigated by dividing the 239-m2 lot into three cells with varying aggregate depths and drainage configurations. Results showed substantial stormwater volume reductions from all permeable pavement configurations, with the most pronounced reductions (99.6 and 100%) experienced in the shallow and deep IWS cells, respectively. Thermal loads from the conventionally drained cell, deep IWS cell, and shallow IWS cell were consequently reduced proportionally to rates of runoff reduction. Median stormwater effluent temperature from the conventionally drained cell (78% runoff reduction) exceeded the critical trout threshold temperature of 21°C; however, outflow only occurred during eight storm events (out of the 54 recorded) and exceeded 21°C for 10.5 h of the stream temperature monitoring period (4.7 h more than ambient stream conditions). Effluent from the two cells with IWS never exceeded trout threshold temperatures because of retention and exfiltration of virtually all incoming stormwater. Temperature differentials between the top and bottom of the PICP profiles suggest that buffering of extreme runoff temperatures can occur. The subsoil interface never reached freezing temperatures during the unseasonably cold winter months, suggesting that frost heaving of permeable pavement systems is not expected in similar climes. These results merit the use of PICP and perhaps other forms of permeable pavement, particularly with the incorporation of IWS, where thermal impact to streams is of concern. DA - 2013/2// PY - 2013/2// DO - 10.1061/(asce)ee.1943-7870.0000626 VL - 139 IS - 2 SP - 187-195 SN - 1943-7870 KW - Permeable pavement KW - Stormwater KW - PICP KW - Permeable interlocking pavers KW - Runoff reduction KW - Temperature KW - Trout KW - Thermal mitigation KW - Field monitoring KW - Freezing ER - TY - JOUR TI - Flocculation Optimization of Microalga Nannochloropsis oculata AU - Shen, Y. AU - Cui, Y. AU - Yuan, W. T2 - APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY DA - 2013/4// PY - 2013/4// DO - 10.1007/s12010-013-0123-4 VL - 169 IS - 7 SP - 2049-2063 SN - 1559-0291 KW - Algae KW - Aluminum sulfate KW - Ferric chloride KW - Nannochloropsis oculata KW - Flocculation KW - RSM ER - TY - JOUR TI - Evaluation of floating treatment wetlands as retrofits to existing stormwater retention ponds AU - Winston, Ryan J. AU - Hunt, William F. AU - Kennedy, Shawn G. AU - Merriman, Laura S. AU - Chandler, Jacob AU - Brown, David T2 - Ecological Engineering AB - Thousands of existing wet retention ponds have been built across the United States, primarily for the mitigation of peak flow and removal of sediment. These systems struggle to mitigate soluble nutrient loads from urban watersheds. A simple retrofit for improvement of pond performance for nitrogen and phosphorus removal could become popular. Floating treatment wetlands (FTWs), one such retrofit, are a hydroponic system that provides a growing medium for hydrophytic vegetation, which obtain nutrients from the stormwater pond. Installation of FTWs does not require earth moving, eliminates the need for additional land to be dedicated to treatment, and does not detract from the required storage volume for wet ponds (because they float). To test whether FTWs reduce nutrients and sediment, two ponds in Durham, NC, were monitored pre- and post-FTW installation. At least 16 events were collected from each pond during both monitoring periods. The distinguishing characteristic between the two ponds post-retrofit was the fraction of pond surface covered by FTWs; the DOT pond and Museum ponds had 9% and 18%, respectively, of their surface area covered by FTWs. A very small fraction of N and P was taken up by wetland plants, with less than 2% and 0.2%, respectively, of plant biomass as N and P. Temperature measurements at three depths below FTWs and at the same depths in open water showed no significant difference in mean daily temperatures, suggesting little shading benefit from FTWs. The two ponds produced effluent temperatures that exceeded trout health thresholds. Both the pre- and post-FTW retrofit ponds performed well from a pollutant removal perspective. One pond had extremely low total nitrogen (TN) effluent concentrations (0.41 mg/L and 0.43 mg/L) during both pre- and post-FTW retrofit periods, respectively. Floating treatment wetlands tended to improve pollutant capture within both ponds, but not always significantly. Mean effluent concentrations of TN were reduced at the DOT pond from 1.05 mg/L to 0.61 mg/L from pre- to post-retrofit. Mean total phosphorus (TP) effluent concentrations were reduced at both wet ponds from pre- to post-retrofit [0.17 mg/L to 0.12 mg/L (DOT pond) and 0.11 mg/L to 0.05 mg/L (Museum pond)]. The post-retrofit effluent concentrations were similar to those observed for bioretention cells and constructed stormwater wetlands in North Carolina. The DOT pond showed no significant differences between pre- and post-retrofit effluent concentrations for all nine analytes. The Museum pond had a statistically significant improvement post-retrofit (when compared to the pre-retrofit period) for both TP and total suspended solids (TSS). Wetland plant root length was measured to be approximately 0.75 m, which had the benefit of stilling water flow, thereby increasing sedimentation. Results suggested that greater percent coverage of FTWs produced improved pollutant removal. DA - 2013/5// PY - 2013/5// DO - 10.1016/J.ECOLENG.2013.01.023 VL - 54 SP - 254-265 J2 - Ecological Engineering LA - en OP - SN - 0925-8574 UR - http://dx.doi.org/10.1016/J.ECOLENG.2013.01.023 DB - Crossref KW - Retention basin KW - Nutrients KW - Sediment KW - Urban KW - Floating wetland island KW - Stormwater runoff KW - Ponds KW - Wetland treatment KW - Nitrogen KW - Phosphorus KW - Temperature KW - Salmonids KW - Trout KW - FTW ER - TY - JOUR TI - Effect of infrared finishing process parameters on physical, mechanical, and sensory properties of par-fried, infrared-finished gluten-free donuts AU - Melito, Helen S. AU - Farkas, Brian E. T2 - JOURNAL OF FOOD ENGINEERING AB - Infrared radiation (IR) can simulate the heat flux created during the frying process, yielding products with fried-like textures but lower fat content. The objective of this study was to determine the process parameters needed to produce partially-fried, infrared-finished gluten-free (GF) donuts having similar instrumental and sensorial properties to fully-fried wheat and GF donuts but lower fat content. Eight different IR oven parameter settings were tested. All GF donuts had significantly lower (p ⩽ 0.05) fat content (23.7–28.2%) than the wheat control (33.7%). Several IR oven parameters yielded donuts that were instrumentally similar to the wheat and GF controls. All IR-finished GF donuts received significantly lower overall acceptance scores (3.81–3.44) than the wheat control (6.94), although they had similar sensory scores to the GF control (4.54). Infrared radiation may be used to finish-fry partially-fried GF donuts to produce donuts significantly lower in fat, yet instrumentally and sensorially similar to fully-fried GF donuts. DA - 2013/8// PY - 2013/8// DO - 10.1016/j.jfoodeng.2013.03.012 VL - 117 IS - 3 SP - 399-407 SN - 1873-5770 KW - Frying KW - Infrared KW - Donut KW - Gluten-free KW - Fat content KW - Process ER - TY - JOUR TI - Techniques for measuring particle size distribution of particulate matter emitted from animal feeding operations AU - Wang-Li, Lingjuan AU - Cao, Zihan AU - Buser, Michael AU - Whitelock, Derek AU - Parnell, Calvin B. AU - Zhang, Yuanhui T2 - ATMOSPHERIC ENVIRONMENT AB - While various techniques for measuring particle size distributions (PSD) of particulate matter (PM) exist, there is no a single agreed upon standard or reference method for PM with different characteristics. This study investigated differences in the PSD measurements by four PSD analyzers: LS13 320 multi-wave length laser diffraction particle size analyzer, LS230 laser diffraction particle size analyzer, LA-300 laser scattering particle size analyzer, and Coulter Counter Multisizer3 (CCM3). Simultaneously collected total suspended particulate (TSP) samples in a commercial egg production house were analyzed by the four analyzers for PSDs. In addition, four types of testing powders (limestone, starch, No.3 micro aluminum, and No.5 micro aluminum) were also analyzed by these four PSD analyzers. The results suggest when comparing measured mass median diameters (MMDs) and geometric standard deviations (GSD) of the PSDs, the laser diffraction method (LS13 320, LS230 and LA-300) provided larger MMDs and broader distributions (GSDs) than the electrical sensing zone method (CCM3) for all samples. When comparing mass fractions of PM10 and PM2.5 between the measured values and the lognormal fitting values derived from the measured MMDs and GSDs, lognormal fitting method produced reasonably accurate PM10 mass fraction estimations (within 5%), but it failed to produce accurate PM2.5 mass fraction estimations. The measured PM2.5 mass fractions significantly differed from the lognormal fitting PM2.5 fractions and the mean differences reached as high as 95%. It is strongly recommended that when reporting a PSD of certain PM samples, in addition to MMD and GSD, the mass fractions of PM10 and PM2.5 should also be reported. DA - 2013/2// PY - 2013/2// DO - 10.1016/j.atmosenv.2012.08.051 VL - 66 SP - 25-32 SN - 1873-2844 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84871086020&partnerID=MN8TOARS KW - Particulate matter KW - Animal feeding operation KW - Particle size distribution analyzer KW - Laser diffraction KW - Electrical sensing zone KW - PM10 mass fraction KW - PM25 mass fraction ER - TY - JOUR TI - Potential of Potassium Hydroxide Pretreatment of Switchgrass for Fermentable Sugar Production AU - Sharma, Rajat AU - Palled, Vijaykumar AU - Sharma-Shivappa, Ratna R. AU - Osborne, Jason T2 - APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY DA - 2013/2// PY - 2013/2// DO - 10.1007/s12010-012-0009-x VL - 169 IS - 3 SP - 761-772 SN - 1559-0291 KW - Switchgrass KW - Lignocelluloses KW - KOH KW - Enzymatic hydrolysis KW - AIL KW - Fermentable sugars ER - TY - JOUR TI - Operating condition optimization of corncob hydrothermal conversion for bio-oil production AU - Gan, Jing AU - Yuan, Wenqiao T2 - APPLIED ENERGY AB - The effect of reaction temperature, retention time, biomass content, and catalyst loading on bio-oil yield, carbon content, and carbon recovery of corncob hydrothermal conversion was investigated and optimized via response surface methodology (RSM). The four variables ranged from 280 to 340 °C for temperature, 12–48 min for retention time, 9–21% for biomass solid content, and 0.76–2.25% for catalyst loading. It was found from RSM modeling that higher bio-oil yield and higher carbon recovery could be achieved at relatively low temperatures and short retention times with high biomass solid contents and moderate alkaline catalyst loadings in the test ranges. A maximum bio-oil yield of 41.3% and maximum carbon recovery of 47.1% were obtained at 280 °C, 12 min, and 21% biomass solid content with 1.03–1.56% catalyst loading. Bio-oil carbon content was found affected only by the reaction temperature and biomass solid content in the RSM model. Higher temperature and lower biomass solid content were favored. The highest bio-oil carbon content of 74.8% was achieved at 340 °C with 9% biomass solid content. The predicted bio-oil yield, carbon content and carbon recovery were in close agreement with validation experiment results, indicating that the RSM models were accurate in designing and optimizing the hydrothermal conversion of corncobs. DA - 2013/3// PY - 2013/3// DO - 10.1016/j.apenergy.2012.09.053 VL - 103 SP - 350-357 SN - 1872-9118 KW - Bio-oil KW - Carbon recovery KW - Corncobs KW - Hydrothermal conversion KW - Liquefaction KW - Response surface methodology ER - TY - JOUR TI - Generalized Markov graph model: Application to social network analysis AU - Schuster, B. G. AU - Chinn, M. S. T2 - Bioenergy Research DA - 2013/// PY - 2013/// VL - 6 IS - 2 SP - 416-435 ER - TY - JOUR TI - Feline Musculoskeletal Pain Index: Responsiveness and Testing of Criterion Validity AU - Benito, J. AU - Hansen, B. AU - DePuy, V. AU - Davidson, G. S. AU - Thomson, A. AU - Simpson, W. AU - Roe, S. AU - Hardie, E. AU - Lascelles, B. D. X. T2 - JOURNAL OF VETERINARY INTERNAL MEDICINE AB - Progress in establishing if therapies provide relief to cats with degenerative joint disease (DJD)-associated pain is hampered by a lack of validated owner-administered assessment methods.That an appropriately developed subjective owner-completed instrument (Feline Musculoskeletal Pain Index-FMPI) to assess DJD-associated impairment would have responsiveness and criterion validity.Twenty-five client-owned cats with DJD-associated pain.FMPI responsiveness (ability to detect the effect of an analgesic treatment) and validity (correlation with an objective measure) were explored through a stratified, randomized, double blinded, placebo-controlled, crossover 10-week clinical study. Meloxicam was administered to effect pain relief. A linear mixed model, backward stepwise regression, and Pearson correlations were used to assess responsiveness and criterion validity with the assumption that the NSAID would increase activity.Positive responses of cats to placebo (P = .0001) and meloxicam treatment (P = .0004) were detected; however, the instrument did not detect any difference between placebo and meloxicam (linear mixed model), even for the high impairment cases. Percent meloxicam target dose administered, temperament, and total baseline FMPI score were covariates that most affected FMPI scores. Controlling for significant covariates, most positive effects were seen for placebo treatment. Positive treatment effects on activity were detected, but only for the cases designated as most highly impaired.Neither responsiveness nor criterion validity were detected by the inclusion criteria for cases in this study. The data suggest that further work is indicated to understand factors affecting activity in cats to optimize inclusion criteria. DA - 2013/// PY - 2013/// DO - 10.1111/jvim.12077 VL - 27 IS - 3 SP - 474-482 SN - 0891-6640 KW - DJD KW - Chronic pain KW - Feline KW - FMPI KW - Meloxicam ER - TY - JOUR TI - Factors controlling nitrate concentrations in surface waters of an artificially drained agricultural watershed AU - Billy, Claire AU - Birgand, François AU - Ansart, Patrick AU - Peschard, Julien AU - Sebilo, Mathieu AU - Tournebize, Julien T2 - Landscape Ecology DA - 2013/3/17/ PY - 2013/3/17/ DO - 10.1007/s10980-013-9872-2 VL - 28 IS - 4 SP - 665-684 J2 - Landscape Ecol LA - en OP - SN - 0921-2973 1572-9761 UR - http://dx.doi.org/10.1007/s10980-013-9872-2 DB - Crossref KW - Nitrate KW - Land use KW - Isotopic nitrogen KW - Retention KW - Subsurface drainage KW - Forested area ER - TY - JOUR TI - Concentration and particle size distribution of particulate matter inside tunnel-ventilated high-rise layer operation houses AU - Wang-Li, Lingjuan AU - Cao, Zihan AU - Li, Qianfeng AU - Liu, Zifei AU - Beasley, David B. T2 - ATMOSPHERIC ENVIRONMENT AB - Particulate matter (PM) is a criteria pollutant emitted from animal feeding operation (AFO) facilities, especially from poultry operation buildings. Fundamental data regarding AFO PM either do not exist, or are not representative of different animal production systems or housing types. This field study investigated particle size distributions (PSDs) and concentrations of total suspended particulate (TSP) in a tunnel ventilated high-rise layer house under different operational conditions. Six low-volume (1 m3 h−1) TSP samplers were used to collect PM samples on two floors of the high-rise layer houses across four seasons through day/night sampling protocols. The day/night sampling design was to examine animal activity impact. The PM samples were analyzed by a multi-wave length laser diffraction particle size analyzer (LS13 320) for PSDs characterized by mass median diameters (MMDs) and geometric standard deviations (GSDs). It was discovered that the mean TSP concentrations ranged from 1.0 ± 0.5 mg m−3 to 5.33 ± 0.36 mg m−3 (mean ± SD). TSP concentrations in winter were higher than in summer; concentrations on the 2nd floor were higher than that on the 1st floor; concentrations of daytime samples were higher than those of nighttime samples. Animal activity (represented by day/night samples) had the highest impact on TSP concentration as compared to other influential factors (spatial, seasonal, ventilation). No significant seasonal variations of MMD and GSD were observed in most of samples. Majority of day/night MMDs and GSDs demonstrated no significant differences. Thus the impact of animal activity (day vs. night) on MMD and GSD were not significant. Mean MMDs ± SDs ranged from 16.81 ± 1.57 μm to 20.26 ± 3.53 μm, whereas means ± SDs of GSDs ranged from 2.38 ± 0.20 to 2.81 ± 0.30. Mean PM2.5 fractions ± SDs ranged from 5.03 ± 1.60% to 8.93 ± 0.97%, whereas mean PM10 fractions ± SDs ranged from 23.25 ± 5.18% to 38.55 ± 2.96%. Significant seasonal variation in both PM10 and PM2.5 mass fractions were observed. DA - 2013/2// PY - 2013/2// DO - 10.1016/j.atmosenv.2012.03.064 VL - 66 SP - 8-16 SN - 1873-2844 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84871094175&partnerID=MN8TOARS KW - Animal feeding operations KW - Hen layer operation KW - Particulate matter KW - TSP KW - Particle size distribution ER - TY - JOUR TI - Calibration and validation of DRAINMOD to model bioretention hydrology AU - Brown, R.A. AU - Skaggs, R.W. AU - Hunt, W.F., III T2 - Journal of Hydrology AB - Previous field studies have shown that the hydrologic performance of bioretention cells varies greatly because of factors such as underlying soil type, physiographic region, drainage configuration, surface storage volume, drainage area to bioretention surface area ratio, and media depth. To more accurately describe bioretention hydrologic response, a long-term hydrologic model that generates a water balance is needed. Some current bioretention models lack the ability to perform long-term simulations and others have never been calibrated from field monitored bioretention cells with underdrains. All peer-reviewed models lack the ability to simultaneously perform both of the following functions: (1) model an internal water storage (IWS) zone drainage configuration and (2) account for soil–water content using the soil–water characteristic curve. DRAINMOD, a widely-accepted agricultural drainage model, was used to simulate the hydrologic response of runoff entering a bioretention cell. The concepts of water movement in bioretention cells are very similar to those of agricultural fields with drainage pipes, so many bioretention design specifications corresponded directly to DRAINMOD inputs. Detailed hydrologic measurements were collected from two bioretention field sites in Nashville and Rocky Mount, North Carolina, to calibrate and test the model. Each field site had two sets of bioretention cells with varying media depths, media types, drainage configurations, underlying soil types, and surface storage volumes. After 12 months, one of these characteristics was altered – surface storage volume at Nashville and IWS zone depth at Rocky Mount. At Nashville, during the second year (post-repair period), the Nash–Sutcliffe coefficients for drainage and exfiltration/evapotranspiration (ET) both exceeded 0.8 during the calibration and validation periods. During the first year (pre-repair period), the Nash–Sutcliffe coefficients for drainage, overflow, and exfiltration/ET ranged from 0.6 to 0.9 during both the calibration and validation periods. The bioretention cells at Rocky Mount included an IWS zone. For both the calibration and validation periods, the modeled volume of exfiltration/ET was within 1% and 5% of the estimated volume for the cells with sand (Sand cell) and sandy clay loam (SCL cell) underlying soils, respectively. Nash–Sutcliffe coefficients for the SCL cell during both the calibration and validation periods were 0.92. DA - 2013/4// PY - 2013/4// DO - 10.1016/J.JHYDROL.2013.02.017 VL - 486 SP - 430-442 J2 - Journal of Hydrology LA - en OP - SN - 0022-1694 UR - http://dx.doi.org/10.1016/J.JHYDROL.2013.02.017 DB - Crossref KW - Bioretention KW - DRAINMOD KW - Hydrology KW - Long-term model KW - Internal water storage zone KW - Modeling ER - TY - JOUR TI - A Connected Set of Genes Associated with Programmed Cell Death Implicated in Controlling the Hypersensitive Response in Maize AU - Olukolu, Bode A. AU - Negeri, Adisu AU - Dhawan, Rahul AU - Venkata, Bala P. AU - Sharma, Pankaj AU - Garg, Anshu AU - Gachomo, Emma AU - Marla, Sandeep AU - Chu, Kevin AU - Hasan, Anna AU - Ji, Jiabing AU - Chintamanani, Satya AU - Green, Jason AU - Shyu, Chi-Ren AU - Wisser, Randall AU - Holland, James AU - Johal, Guri AU - Balint-Kurti, Peter T2 - GENETICS AB - Abstract Rp1-D21 is a maize auto-active resistance gene conferring a spontaneous hypersensitive response (HR) of variable severity depending on genetic background. We report an association mapping strategy based on the Mutant Assisted Gene Identification and Characterization approach to identify naturally occurring allelic variants associated with phenotypic variation in HR. Each member of a collection of 231 diverse inbred lines of maize constituting a high-resolution association mapping panel were crossed to a parental stock heterozygous for Rp1-D21, and the segregating F1 generation testcrosses were evaluated for phenotypes associated with lesion severity for 2 years at two locations. A genome-wide scan for associations with HR was conducted with 47,445 SNPs using a linear mixed model that controlled for spurious associations due to population structure. Since the ability to identify candidate genes and the resolution of association mapping are highly influenced by linkage disequilibrium (LD), we examined the extent of genome-wide LD. On average, marker pairs separated by &gt;10 kbp had an r2 value of &lt;0.1. Genomic regions surrounding SNPs significantly associated with HR traits were locally saturated with additional SNP markers to establish local LD structure and precisely identify candidate genes. Six significantly associated SNPs at five loci were detected. At each locus, the associated SNP was located within or immediately adjacent to candidate causative genes predicted to play significant roles in the control of programmed cell death and especially in ubiquitin pathway-related processes. DA - 2013/2// PY - 2013/2// DO - 10.1534/genetics.112.147595 VL - 193 IS - 2 SP - 609-+ SN - 0016-6731 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84876366651&partnerID=MN8TOARS ER - TY - JOUR TI - Production of polyhydroxybutyrate (PHB) by Alcaligenes latus using sugarbeet juice AU - Wang, Bingqing AU - Sharma-Shivappa, Ratna R. AU - Olson, Jonathan W. AU - Khan, Saad A. T2 - INDUSTRIAL CROPS AND PRODUCTS AB - The practicality of using sugarbeet juice as medium to grow Alcaligenes latus (ATCC 29714) for production of polyhydroxybutyrate (PHB), a biodegradable plastic, was explored in this study. Dilute sugarbeet juice, sugarbeet juice with partial and complete addition of nutrients other than sugar were used as culture media. Media with partial nutrient addition was shown to be optimal for PHB production, with final dry cell weight (DCW) 10.30 ± 1.01 g/L, PHB concentration 4.01 ± 0.95 g/L, PHB content 38.66 ± 7.28%, Yp/x (g PHB produced per g dry cell weight) 0.39 ± 0.07 and a maximum PHB productivity of 0.22 ± 0.01 g/L h. The melting temperature of PHB extracted from sugarbeet juice-grown cells supplemented with partial nutrients was measured to be 151.46 °C with crystallinity of 43.12% and the corresponding crystallinity temperature of 45.42 °C. Thermal degradation of extracted PHB occurred from 255.14 to 283.69 °C with the degradation peak at 273.86 °C. DA - 2013/5// PY - 2013/5// DO - 10.1016/j.indcrop.2012.08.011 VL - 43 SP - 802-811 SN - 1872-633X KW - Biodegradable plastics KW - Polyhydroxyalkanoate (PHA) KW - Sucrose KW - Two-stage batch fermentation ER - TY - JOUR TI - Identification of Bioaerosols Released from an Egg Production Facility in the Southeast United States AU - Wang-Li, Lingjuan AU - Li, Qianfeng AU - Byfield, Grace E. T2 - ENVIRONMENTAL ENGINEERING SCIENCE AB - This field study investigated biological characteristics of aerosols emitted from a commercial egg production farm (layer operation). Bioaerosol samples were taken on this farm at five sampling locations covering emission source (inside a layer barn) and four ambient surrounding stations at four wind directions. All-glass impingers (AGI) were used for the field sampling. AGI fluid samples were plated in duplicate on Trypticase Soy Agar for growth of bacteria and Sabouraud Dextrose Agar for growth of fungi. The most prominent bacterial colony types were identified using a combination of methods that include recording characteristics of colony morphology; performing a Gram staining method and metabolic analyses using the Biolog system. Results from thirty-five AGI samples taken at the five stations through seven sampling events over four seasons indicate that there were significantly lower total bacterial concentrations in the samples collected from ambient stations as compared with the samples collected in the layer house; the mean bacterial concentration at the in-house sampling station was 3.86×10(5)±1.74×10(5) cfu/m(3), whereas the mean bacterial concentrations at four ambient stations in the vicinity of the farm ranged from 1.3×10(3) to 6.2×10(3) cfu/m(3) with no significant differences in mean among ambient stations. There were also no significant differences in fungi concentrations among all sampling stations. Mean fungi concentrations at the in-house station was 3.0×10(3)±4.45×10(3) cfu/m(3), whereas the mean concentrations at the ambient stations ranged from 7.4×10(3) to 1.7×10(4) cfu/m(3). The most prominent bacterial species differed among all five stations. Three of the most prominent bacteria from samples taken at all five stations were gram positive. Fungal type also differed from station to station. DA - 2013/1// PY - 2013/1// DO - 10.1089/ees.2011.0517 VL - 30 IS - 1 SP - 2-10 SN - 1557-9018 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-84874096303&partnerID=MN8TOARS ER - TY - JOUR TI - Aromatization of n-octane over Pd/C catalysts AU - Yin, Mengchen AU - Natelson, Robert H. AU - Campos, Andrew A. AU - Kolar, Praveen AU - Roberts, William L. T2 - FUEL AB - Abstract Gas-phase aromatization of n-octane was investigated using Pd/C catalyst. The objectives were to: (1) determine the effects of temperature (400–600 °C), weight hourly space velocity (WHSV) (0.8–∞), and hydrogen to hydrocarbon molar ratio (MR) (0–6) on conversion, selectivity, and yield (2) compare the activity of Pd/C with Pt/C and Pt/KL catalysts and (3) test the suitability of Pd/C for aromatization of different alkanes including n-hexane, n-heptane, and n-octane. Pd/C exhibited the best aromatization performance, including 54.4% conversion and 31.5% aromatics yield at 500 °C, WHSV = 2 h−1, and a MR of 2. The Pd/C catalyst had higher selectivity towards the preferred aromatics including ethylbenzene and xylenes, whereas Pt/KL had higher selectivity towards benzene and toluene. The results were somewhat consistent with adsorbed n-octane cyclization proceeding mainly through the six-membered ring closure mechanism. In addition, Pd/C was also capable of catalyzing aromatization of n-hexane and n-heptane. DA - 2013/1// PY - 2013/1// DO - 10.1016/j.fuel.2012.06.095 VL - 103 SP - 408-413 SN - 1873-7153 KW - Aromatization KW - Dehydrocyclization KW - Catalyst KW - Pd/C KW - Alkanes ER - TY - JOUR TI - Hydrolysis and fermentation of sweetpotatoes for production of fermentable sugars and ethanol AU - Duvernay, William H. AU - Chinn, Mari S. AU - Yencho, G. Craig T2 - INDUSTRIAL CROPS AND PRODUCTS AB - Liquefaction, saccharification, and fermentation of FTA-94 industrial sweetpotatoes (ISPs) were examined using α-amylase and glucoamylase for the production of ethanol. Starch degradation and sugars produced over time were examined for (1) α-amylase (Liquozyme SC) at different loading rates (0.045, 0.45, and 4.5% KNU-S/g dry ISP) during liquefaction; and (2) three glucoamylases (Spirizyme Fuel, Spirizyme Plus Tech, and Spirizyme Ultra) at different loading rates (0.5, 1.0, and 5.0 AGU/g dry ISP) during saccharification. The majority of starch, 47.7 and 65.4% of dry matter, was converted during liquefaction of flour and fresh sweetpotato preparations, respectively, with the addition of 0.45 KNU-S/g dry ISP of Liquozyme SC after 2 h (66.4 and 80.1% initial starch in dry matter, respectively). The enzymes used during saccharification increased starch breakdown, but was more effective in conversion of short chain carbohydrates to fermentable sugars. The addition of 5.0 AGU/g of Spirizyme Ultra after 48 h produced 795.4 and 685.3 mg glucose/g starch with flour and fresh preparations, respectively. Yeast fermentation on hydrolyzed starch was examined over time with and without the addition of salt nutrients. Yeast converted all fermentable sugar (e.g. glucose, fructose, maltose) and produced 62.6 and 33.6 g ethanol/L of hydrolysate for flour (25% w/v, substrate loading) and fresh (12.5% w/v, substrate loading) ISP, respectively, after 48 h without salt addition. DA - 2013/3// PY - 2013/3// DO - 10.1016/j.indcrop.2012.06.028 VL - 42 SP - 527-537 SN - 1872-633X KW - Industrial sweet potatoes KW - Enzymes KW - Hydrolysis KW - Fermentation KW - Glucose KW - Ethanol ER -