TY - JOUR TI - Robust and Scalable Game-theoretic Security Investment Methods for Voltage Stability of Power Systems AU - An, Lu AU - Shukla, Pratishtha AU - Chakrabortty, Aranya AU - Duel-Hallen, Alexandra T2 - 2023 62ND IEEE CONFERENCE ON DECISION AND CONTROL, CDC DA - 2023/// PY - 2023/// DO - 10.1109/CDC49753.2023.10383722 SP - 7061-7066 SN - 2576-2370 KW - Power Systems KW - Voltage stability KW - Load attacks KW - Game Theory KW - Security investment KW - Robust defense ER - TY - JOUR TI - Game-Theoretic Mixed H2/H Control with Sparsity Constraint for Multi-Agent Control Systems AU - Lian, Feier AU - Chakrabortty, Aranya AU - Duel-Hallen, Alexandra T2 - 2023 62ND IEEE CONFERENCE ON DECISION AND CONTROL, CDC DA - 2023/// PY - 2023/// DO - 10.1109/CDC49753.2023.10384040 SP - 5526-5531 SN - 2576-2370 ER - TY - JOUR TI - Reinforcement Learning based Approximate Optimal Control of Nonlinear Systems using Carleman Linearization AU - Kar, Jishnudeep AU - Bai, He AU - Chakrabortty, Aranya T2 - 2023 AMERICAN CONTROL CONFERENCE, ACC AB - We develop a policy iteration-based model-free reinforcement learning (RL) control for nonlinear systems with single input. First, Carleman linearization, a commonly used linearization technique in the Hilbert space, is applied to express the nonlinear system as an infinite-dimensional Carleman state-space model, followed by derivation of an online state-feedback RL controller using state and input data in this infinite-dimensional space. Next, the practicality of using any finite-order truncation of this controller, and the corresponding closed-loop stability of the nonlinear plant is established. Results are validated using two numerical examples, where we show how our proposed method provides solutions close to the optimal control resulting from the model-based Carleman controllers. We also compare our controller to alternative data-driven methods, showing its advantage in terms of shorter learning time. DA - 2023/// PY - 2023/// DO - 10.23919/ACC55779.2023.10156057 SP - 3362-3367 SN - 2378-5861 ER - TY - JOUR TI - High-Performance Hybrid MPPT Algorithm Based Single-Stage Solar PV Fed Induction Motor Drive for Standalone Pump Application AU - Jain, Sachin AU - Kumar Ch, S. V. S. Phani AU - Sonti, Venu AU - Keskar, Aditya AU - Johnson, Jeremiah X. AU - Ghosh, Subhojit AU - Patel, R. N. T2 - IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS AB - The article presents a high-performance hybrid sample-based perturb and observe (P&O) maximum power point tracking (MPPT) algorithm for a single-stage solar photovoltaic (SPV) fed open-end winding induction motor (OEWIM) driven standalone pumping system. Traditionally, the P&O algorithm utilizes slow sample-based computation for MPPT to avoid high oscillations near MPP. The slow sample-based algorithm has the drawback of poor tracking speed and loss of MPPT for the environmental change corresponding to the decrement in the PV power (i.e., step decrement in irradiance). Conversely, the algorithm designed for a faster sample rate faces the drawback of poor MPPT performance due to high oscillations near MPP. The proposed algorithm integrates the advantages of both fast and slow sample-based P&O MPPT algorithms. It switches to the fast sample-based MPPT when the PV operating point is away from MPP or there is a change in environmental conditions. It switches back to slow sample-based MPPT algorithms when the operating point reaches near MPP. The complete details of the proposed hybrid sample-based MPPT algorithm for the SPV pump application system are given in the article. Further, a comparative analysis of the proposed algorithm performance with both fast and slow sample-based algorithms is also carried out using MATLAB/Simulink simulation environment. The simulation results demonstrate the superior performance of the proposed algorithm in terms of MPPT speed and accuracy. The enhanced MPP accuracy further improves the pump performance by minimizing torque and speed ripple. The robustness of the proposed strategy is also elucidated experimentally. DA - 2023/11// PY - 2023/11// DO - 10.1109/TIA.2023.3310490 VL - 59 IS - 6 SP - 7103-7115 SN - 1939-9367 KW - Maximum power point tracking (MPPT) KW - open end winding induction motor KW - solar photovoltaic (SPV) KW - voltage source inverter (VSI) ER - TY - JOUR TI - Effect of composition of volatile fatty acids on yield of polyhydroxyalkanoates and mechanisms of bioconversion from activated sludge AU - Zhang, Ziying AU - Lin, Yan AU - Wu, Shaohua AU - Li, Xiang AU - Cheng, Jay J. AU - Yang, Chunping T2 - BIORESOURCE TECHNOLOGY AB - Polyhydroxyalkanoates (PHA) is green biodegradable natural polymer. Here PHA production from volatile fatty acids (VFAs) was investigated in sequential batch reactors inoculated with activated sludge. Single or mixed VFAs ranging from acetate to valerate were evaluated, and the dominant VFA concentration was 2 times of that of the others in the tests. Results showed that mixed substrates achieved about 1.6 times higher yield of PHA production than single substrate. The butyrate-dominated substrates maximized PHA content at 72.08% of VSS, and the valerate-dominated substrates were followed with PHA content at 61.57%. Metabolic flux analysis showed the presence of valerate in the substrates caused a more robust PHA production. There was at least 20% of 3-hydroxyvalerate in the polymer. Hydrogenophaga and Comamonas were the main PHA producers. As VFAs could be produced in anaerobic digestion of organic wastes, the methods and data here could be referred for efficient green bioconversion of PHA. DA - 2023/10// PY - 2023/10// DO - 10.1016/j.biortech.2023.129445 VL - 385 SP - SN - 1873-2976 KW - Biomass KW - Volatile fatty acid KW - Polyhydroxyalkanoate KW - Butyrate ER - TY - JOUR TI - Redefining exposure science to advance research supporting cumulative impacts, environmental justice, and decision-making AU - Tulve, N.S. AU - Guiseppi-Elie, A. AU - Geller, A.M. AU - Ward-Caviness, C.K. AU - Paul, S.J. AU - Lavoie, E.T. AU - Rivers, L. AU - Frey, H.C. T2 - Journal of Exposure Science and Environmental Epidemiology DA - 2023/// PY - 2023/// DO - 10.1038/s41370-023-00610-5 VL - 33 IS - 6 SP - 843-845 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85176085804&partnerID=MN8TOARS ER - TY - JOUR TI - Spatial and Temporal Variation of Subseasonal-to-Seasonal (S2S) Precipitation Reforecast Skill Across CONUS AU - Levey, Jessica Rose AU - Sankarasubramanian, Arumugam AB - Precipitation forecasts, particularly at subseasonal-to-seasonal (S2S) time scale, are essential for informed and proactive water resources management. Although S2S precipitation forecasts have been evaluated, no systematic decomposition of the skill, Nash-Sutcliffe Efficiency (NSE) coefficient, has been analyzed towards understanding the forecast accuracy. We decompose the NSE of S2S precipitation forecast into its three components – correlation, conditional bias, and unconditional bias – by four seasons, three lead times (1–12-day, 1-22 day, and 1-32 day), and three models (ECMWF, CFS, NCEP) over the Conterminous United States (CONUS). Application of dry mask is critical as the NSE and correlation are lower across all seasons after masking areas with low precipitation values. Further, a west-to-east gradient in S2S forecast skill exists and forecast skill was better during the winter months and for areas closer to the coast. Overall, ECMWF’s model performance was stronger than both ECCC and NCEP CFS’s performance, mainly for the forecasts issued during fall and winter months. However, ECCC and NCEP CFS performed better for the forecast issued during the spring months, and also performed better in in-land areas. Post-processing using simple Model Output Statistics could reduce both unconditional and conditional bias to zero, thereby offering better skill for regimes with high correlation. Our decomposition results also show efforts should focus on improving model parametrization and initialization schemes for climate regimes with low correlation values. DA - 2023/9/13/ PY - 2023/9/13/ DO - 10.22541/essoar.169461965.53386198/v1 UR - https://doi.org/10.22541/essoar.169461965.53386198/v1 ER - TY - JOUR TI - Regionalization of Climate Elasticity Preserves Dooge's Complementary Relationship AU - Awasthi, Chandramauli AU - Vogel, Richard M. AU - Sankarasubramanian, Arumugam AB - Climate elasticity of streamflow represents a nondimensional measure of the sensitivity of streamflow to climatic factors. Estimation of such elasticities from observational records has become an important alternative to scenario-based methods of evaluating streamflow sensitivity to climate. Nearly all previous elasticity studies have used a definition of elasticity known as arc elasticity, which measures changes in streamflow about mean values of streamflow and climate. Using observational records in western U.S., our findings reveal that elasticity definitions based on power law models lead to both regional and basin specific estimates of elasticity which are physically more realistic than estimates based on arc elasticity. Evaluating the ability of arc and power law elasticity estimators in reproducing Dooge’s complementary relationship (DCR) between potential evapotranspiration and precipitation elasticities reveal that power law elasticities estimated from at-site, panel and hierarchical statistical models reproduce DCR, whereas corresponding estimators based on arc elasticity cannot reproduce DCR. Importantly, our regional elasticity formulations using either panel and/or hierarchical formulations led to estimates of both regional and basin specific estimates of elasticities, enabling and contrasting streamflow sensitivity to climate across both basins and regions. DA - 2023/11/8/ PY - 2023/11/8/ DO - 10.22541/essoar.169947261.16344787/v1 UR - https://doi.org/10.22541/essoar.169947261.16344787/v1 ER - TY - JOUR TI - Generalizing Reservoir Operations Using a Piecewise Classification and Regression Approach AU - Ford, Lucas AU - Sankarasubramanian, A. T2 - Water Resources Research AB - Abstract Inflow anomalies at varying temporal scales, seasonally varying storage mandates, and multipurpose allocation requirements contribute to reservoir operational decisions. The difficulty of capturing these constraints across many basins in a generalized framework has limited the accuracy of streamflow estimates in land‐surface models for locations downstream of reservoirs. We develop a Piecewise Linear Regression Tree to learn generalized daily operating policies from 76 reservoirs from four major basins across the coterminous US. Reservoir characteristics, such as residence time and maximum storage, and daily state variables, such as storage and inflow, are used to group similar observations across all reservoirs. Linear regression equations are then fit between daily state variables and release for each group. We recommend two models—Model 1 (M1) that performs the best when simulating untrained records but is complex and Model 2 (M2) that is nearly as performant as M1 but more parsimonious. The simulated release median root mean squared error is 49.7% (53.2%) of mean daily release with a median Nash‐Sutcliffe efficiency of 0.62 (0.52) for M1 (M2). Long‐term residence time is shown to be useful in grouping similar operating reservoirs. Release from low residence time reservoirs can be mostly described using inflow‐based variables. Operations at higher residence time reservoirs are more related to previous release variables or storage variables, depending on the current inflow. The ability of the models presented to capture operational dynamics of many types of reservoirs indicates their potential to be used for untrained and limited data reservoirs. DA - 2023/9// PY - 2023/9// DO - 10.1029/2023WR034890 UR - https://doi.org/10.1029/2023WR034890 ER - TY - JOUR TI - One‐Parameter Analytical Derivation in Modified Budyko Framework for Unsteady‐State Streamflow Elasticity in Humid Catchments AU - Han, Peng‐Fei AU - Sankarasubramanian, Arumugam AU - Wang, Xu‐Sheng AU - Wan, Li AU - Yao, Lili T2 - Water Resources Research AB - Abstract The changes in climate and catchment properties have altered the hydrological processes significantly at different spatiotemporal scales around the world. In particular for finer time scales, changes in water storage, which has been commonly neglected for long‐term temporal scales, may play an important role on hydrological processes. Nevertheless, few studies addressed this question in modifying the Budyko framework, with most of them remaining a steady‐state assumption on catchment characteristics. Here, we derive new analytical formulas of unsteady‐state streamflow elasticity in a modified Budyko framework, incorporating both storage change and one specific parameter for catchment properties. We study 78 humid catchments in the USA with simulation data of daily hydrological processes from a probability‐distribution‐based hydrological model (the modified HyMOD). As indicated by results, the annual storage change ratio is linearly correlated with the annual aridity index, and this relationship can be used to estimate elasticity coefficients with our formulas. The estimated elasticity coefficients perform well in simulating the annual streamflow with the power‐law model. For different catchments, variability of the unsteady‐state elasticity is higher than that of the steady‐state elasticity. Unsteady‐state streamflow coefficients show significant linear correlation with catchment properties, such as the average slope, average elevation, and catchment area. This study provides a new analytical approach to investigate the interannual stability of catchments with varying climate and catchment properties. DA - 2023/9// PY - 2023/9// DO - 10.1029/2023WR034725 UR - https://doi.org/10.1029/2023WR034725 ER - TY - JOUR TI - Comprehensive Analysis of the NOAA National Water Model: A Call for Heterogeneous Formulations and Diagnostic Model Selection AU - Johnson, J. Michael AU - Fang, Shiqi AU - Sankarasubramanian, Arumugam AU - Rad, Arash Modaresi AU - Cunha, Luciana Kindl AU - Jennings, Keith S. AU - Clarke, Keith C. AU - Mazrooei, Amir AU - Yeghiazarian, Lilit T2 - Journal of Geophysical Research: Atmospheres AB - Abstract With an increasing number of continental‐scale hydrologic models, the ability to evaluate performance is key to understanding uncertainty and making improvements to the model(s). We hypothesize that any model, running a single set of physics, cannot be “properly” calibrated for the range of hydroclimatic diversity as seen in the contenintal United States. Here, we evaluate the NOAA National Water Model (NWM) version 2.0 historical streamflow record in over 4,200 natural and controlled basins using the Nash‐Sutcliffe Efficiency metric decomposed into relative performance, and conditional, and unconditional bias. Each of these is evaluated in the contexts of meteorologic, landscape, and anthropogenic characteristics to better understand where the model does poorly, what potentially causes the poor performance, and what similarities systemically poor performing areas share. The primary objective is to pinpoint traits in places with good/bad performance and low/high bias. NWM relative performance is higher when there is high precipitation, snow coverage (depth and fraction), and barren area. Low relative skill is associated with high potential evapotranspiration, aridity, moisture‐and‐energy phase correlation, and forest, shrubland, grassland, and imperviousness area. We see less bias in locations with high precipitation, moisture‐and‐energy phase correlation, barren, and grassland areas and more bias in areas with high aridity, snow coverage/fraction, and urbanization. The insights gained can help identify key hydrological factors underpinning NWM predictive skill; enforce the need for regionalized parameterization and modeling; and help inform heterogenous modeling systems, like the NOAA Next Generation Water Resource Modeling Framework, to enhance ongoing development and evaluation. DA - 2023/12/27/ PY - 2023/12/27/ DO - 10.1029/2023JD038534 UR - https://doi.org/10.1029/2023JD038534 ER - TY - JOUR TI - Beyond Simple Trend Tests: Detecting Significant Changes in Design‐Flood Quantiles AU - Awasthi, C. AU - Archfield, S. A. AU - Reich, B. J. AU - Sankarasubramanian, A. T2 - Geophysical Research Letters AB - Abstract Changes in annual maximum flood (AMF), which are usually detected using simple trend tests (e.g., Mann‐Kendall test (MKT)), are expected to change design‐flood estimates. We propose an alternate framework to detect significant changes in design‐flood between two periods and evaluate it for synthetically generated AMF from the Log‐Pearson Type‐3 (LP3) distribution due to changes in moments associated with flood distribution. Synthetic experiments show MKT does not consider changes in all three moments of the LP3 distribution and incorrectly detects changes in design‐flood. We applied the framework on 31 river basins spread across the United States. Statistically significant changes in design‐flood quantiles were observed even without a significant trend in AMF and basins with statistically significant trend did not necessarily exhibit statistically significant changes in design‐flood. We recommend application of the framework for evaluating changes in design‐flood estimates considering changes in all the moments as opposed to simple trend tests. DA - 2023/7/16/ PY - 2023/7/16/ DO - 10.1029/2023GL103438 UR - https://doi.org/10.1029/2023GL103438 ER - TY - JOUR TI - Impacts of COVID-19 pandemic policies on timber markets in the Southern United States AU - Bruck, Sonia R. AU - Parajuli, Rajan AU - Chizmar, Stephanie AU - Sills, Erin O. T2 - Journal of Forest Business Research AB - The global pandemic, due to SARS-CoV-2 (COVID-19), disrupted global commodity markets and individual consumption patterns. Various COVID-19-related policies were put in place by state and local governments to limit the virus outbreak, which disrupted the production and supply chains of manufacturing industries. The forest sector was not an exception. Using the Time Regression Discontinuity (T-RD) approach, we quantified the effect of various COVID-19 policies on standing timber prices in the Southern United States. We found an overall significant decrease in prices across all timber products (7%-30%) soon after COVID-19 lockdowns were implemented in early 2020. Findings from the fixed effects (FE) estimators suggest mandatory lockdowns for all individuals in certain areas of the jurisdiction had a decreasing price effect on pine pulpwood but an increasing effect on hardwood sawtimber. We expect that the findings from this study may help to set expectations for future market shocks if policies are implemented that impact the timber supply chain and consumer behavioral changes. DA - 2023/5/11/ PY - 2023/5/11/ DO - 10.62320/jfbr.v2i1.25 UR - https://doi.org/10.62320/jfbr.v2i1.25 ER - TY - JOUR TI - The challenge of non-reactive phosphorus: Mechanisms of treatment and improved recoverability using electrooxidation AU - Mallick, Synthia Parveen AU - Hossain, Mohammad Shakhawat AU - Takshi, Arash AU - Call, Douglas F. AU - Mayer, Brooke K. T2 - JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING AB - Recalcitrant phosphorus (P) species, i.e., soluble non-reactive phosphorus (sNRP), are generally not effectively removed or recovered in conventional wastewater treatment processes. This was substantiated in our meta-analysis, which showed that nearly one-third of wastewater facilities’ effluent P was primarily in the non-reactive form. Transformation of sNRP to more readily removable/recoverable soluble reactive phosphorus (sRP) may offer a viable pathway to enhance P removal and recovery. Electrooxidation (EO) may offer one route for sNRP to sRP transformation. During EO, different sNRP transformation pathways may occur, influencing the extent and efficiency of sNRP transformations as a function of water quality. To explore these mechanisms, we conducted oxidant quenching tests as well as cyclic voltammetry and chronoamperometry experiments using a synthetic water matrix spiked with the sNRP compound beta-glycerol phosphate (BGP). We found that direct electron transfer was responsible for BGP transformation. To assess the applicability of EO for wastewater sNRP to sRP transformation and improved recoverability, EO was used to treat municipal wastewater centrate, followed by tests of sNRP recoverability using the P-selective LayneRT™ ion exchanger. Complete transformation of centrate sNRP to sRP was not achieved with EO, but subsequent removal of sNRP using ion exchange increased after 2 hr of EO treatment. Longer periods of EO treatment did not improve sNRP removal. Improved sNRP adsorption after EO was likely due to decreased competing organics in the centrate after EO treatment. Overall, this study showed that EO can improve sNRP removal using subsequent ion exchange and facilitate enhanced P recovery. DA - 2023/10// PY - 2023/10// DO - 10.1016/j.jece.2023.110295 VL - 11 IS - 5 SP - SN - 2213-3437 KW - Ion exchange KW - Transformation KW - Nutrient removal KW - Wastewater KW - Advanced oxidation process (AOP) KW - Direct electron transfer ER - TY - JOUR TI - Modular Hybrid Transformers Toward Grid Resilience: Efficiency Analysis and Operation AU - Prabowo, Yos AU - Iyer, Vishnu Mahadeva AU - Agarwal, Apoorv AU - Bhattacharya, Subhashish AU - Aeloiza, Eddy T2 - IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS AB - This article proposes modular hybrid transformer architectures to improve grid resilience. The conventional line-frequency transformer is augmented with a partially rated power electronics converter to realize a hybrid transformer system. The proposed modular approach is envisioned to replace a single large power low-frequency transformer with multiple smaller rated hybrid transformer systems during disasters and emergencies. A hybrid transformer system enables controlled current sharing between the modular system. The efficiency analysis and operational aspects of a modular hybrid transformer architecture are thoroughly discussed in this article. The proposed efficiency analysis combines empirical data and numerical analysis of the overall modular hybrid transformer system. The optimum current sharing ratio to achieve maximum efficiency operation is presented for the proposed architectures. One of the proposed architectures (Configuration B) also offers load voltage regulation in case of grid voltage sag/swell occurrence. The proposed concept and analyses are experimentally validated through a scaled-down hardware prototype. The total ownership cost of the proposed system is also presented to emphasize the potential cost-benefits. Supplementary video files accompany this article to showcase the extensive experimental validation cases. DA - 2023/12/27/ PY - 2023/12/27/ DO - 10.1109/TIE.2023.3340215 VL - 12 SP - SN - 1557-9948 UR - https://doi.org/10.1109/TIE.2023.3340215 KW - Current sharing KW - energy efficiency KW - hybrid transformer (HT) KW - line-frequency transformer (LFT) KW - load voltage regulation KW - parallel architecture KW - power grids KW - resilience ER - TY - JOUR TI - Identifying emissions hotspots and strategies to reduce real-world fuel use and emissions for passenger rail: A spatially resolved approach AU - Rastogi, Nikhil AU - Frey, H. Christopher AU - Wei, Tongchuan T2 - SCIENCE OF THE TOTAL ENVIRONMENT AB - The objectives of this work are to model spatially resolved passenger locomotive fuel use and emission rates, locate emissions hotspots, and identify strategies to reduce trip train fuel use and emissions. Train fuel use and emission rates, speed, acceleration, track grade, and track curvature were quantified based on over-the-rail measurements, using portable emission measurement systems, for diesel and biodiesel passenger rail service on the Amtrak-operated Piedmont route. Measurements included 66 one-way trips and 12 combinations of locomotives, consists, and fuels. A locomotive power demand (LPD) based emissions model was developed based on the physics of resistive forces opposing train motion, taking into account factors such as speed, acceleration, track grade, and curvature. The model was applied to locate spatially-resolved locomotive emissions hotspots on a passenger rail route, and also identify train speed trajectories with low trip fuel use and emissions. Results show that acceleration, grade, and drag are the major resistive forces affecting LPD. Hotspot track segments have 3 to 10 times higher emission rates than non-hotspot segments. Real-world trajectories are identified that reduce trip fuel use and emissions by 13 % to 49 % compared to the average. Strategies for reducing trip fuel use and emissions include dispatching energy-efficient and low-emitting locomotives, using a 20 % blend of biodiesel, and operating on low-LPD trajectories. Implementing these strategies will not only decrease trip fuel use and emissions but reduce the number and intensity of hotspots and, thus, lowering the potential for exposure to train-generated pollution near railroad tracks. This work provides insights on reducing railroad energy use and emissions, which would lead to a more sustainable and environmental-friendly rail transportation system. DA - 2023/10/20/ PY - 2023/10/20/ DO - 10.1016/j.scitotenv.2023.165110 VL - 896 SP - SN - 1879-1026 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-85164224998&partnerID=MN8TOARS KW - Emission hotspots KW - Locomotive power demand KW - Passenger train KW - Spatial variability ER - TY - JOUR TI - Tuning the Aggregates of Thiophene-based Trimers by Methyl Side-chain Engineering for Photocatalytic Hydrogen Evolution AU - Yuan, Xiaojiao AU - Yang, Kunran AU - Grazon, Chloe AU - Wang, Cong AU - Vallan, Lorenzo AU - Isasa, Jean-David AU - Resende, Pedro M. AU - Li, Fanxing AU - Brochon, Cyril AU - Remita, Hynd AU - Hadziioannou, Georges AU - Cloutet, Eric AU - Li, Jian T2 - ANGEWANDTE CHEMIE-INTERNATIONAL EDITION AB - Abstract Organic π‐conjugated semiconductors (OCSs) have recently emerged as a promising alternative to traditional inorganic materials for photocatalysis. However, the aggregation of OCSs in photocatalytic aqueous solution caused by self‐assembly, which closely relates to the photocatalytic activity, has not yet been studied. Here, the relationship between the aggregation of 4,7‐Bis(thiophen‐2‐yl) benzothiadiazole (TBT) and the photocatalytic activity was systematically investigated by introducing and varying the position of methyl side chains on the two peripheral thiophene units. Experimental and theoretical results indicated that the introduction of ‐CH 3 group at the 3‐position of TBT resulted in the smallest size and best crystallinity of aggregates compared to that of TBT, 4‐ and 5‐positions. As a result, TBT‐3 exhibited an excellent photocatalytic activity towards H 2 evolution, ascribed to the shorten charge carrier transport distance and solid long‐range order. These results suggest the important role of aggregation behavior of OCSs for efficient photocatalysis. DA - 2023/12/1/ PY - 2023/12/1/ DO - 10.1002/anie.202315333 VL - 12 SP - SN - 1521-3773 KW - Aggregation KW - Hydrogen Production KW - Intramolecular Packing KW - Photocatalysis KW - Thiophene ER - TY - JOUR TI - Opportunities for wave energy in bulk power system operations AU - Akdemir, Kerem Ziya AU - Robertson, Bryson AU - Oikonomou, Konstantinos AU - Kern, Jordan AU - Voisin, Nathalie AU - Hanif, Sarmad AU - Bhattacharya, Saptarshi T2 - APPLIED ENERGY AB - Wave energy resources have high, yet largely untapped potential as candidate generation technology. In this paper, we perform a data-driven analysis to characterize the impact of wave energy integration on bulk-scale power systems and market operations. Through data-driven sensitivity studies centered on an optimization-based production cost modeling formulation, our work characterizes the inflection point beyond which wave integration starts impacting power system operations, considering present day transmission infrastructure. Furthermore, our analysis also considers the joint effects of wave energy integration and system-wide transmission expansion. Finally, potential resilience scenarios such as wildfire-driven transmission contingencies and heat wave events are investigated, whereby the contributions of grid-integrated wave energy in alleviating the effects of the resilience events are analyzed. As our demonstration test bed, we consider a reduced-order network topology for the U.S. Western Interconnection with wave energy generation integrated at carefully selected sites across the coastal areas of Washington, Oregon, and northern California. Our results indicate that over a representative year of operations, wave energy integration systematically reduces locational marginal prices (LMPs) of energy and price volatility, especially during periods of high wave resource availability (winter months for the U.S. west coast). Average, maximum, and minimum of hourly LMPs over a typical year of operation was reduced by 2.95, 51.28, and 1.13 $/MWh respectively (over a baseline scenario with no wave energy integration), when the selected network model had a total of 5000 MW wave power installed capacity during the representative year of study. The effects of wave energy integration can remain localized with existing transmission infrastructure (identified to be most pronounced in the Pacific Northwest region in the example we studied). However, with concurrent transmission expansion, the impacts of wave energy integration are likely to have a higher geographical spread. Our results also indicate that wave energy may be able to assist power system operations during resilience events such as major transmission contingencies and heat wave events, although such benefits might be dependent on factors such as proximity of affected area to wave resources, availability of adequate resource potential and adequate transmission capacity. DA - 2023/12/15/ PY - 2023/12/15/ DO - 10.1016/j.apenergy.2023.121845 VL - 352 SP - SN - 1872-9118 KW - Production cost modeling KW - Marine renewable energy KW - Wave energy KW - Electricity market KW - Power system operations KW - Contingency analysis ER - TY - JOUR TI - The Impact of Wind Energy on Air Pollution and Emergency Department Visits AU - Fell, Harrison AU - Morrill, Melinda Sandler T2 - ENVIRONMENTAL & RESOURCE ECONOMICS DA - 2023/11/29/ PY - 2023/11/29/ DO - 10.1007/s10640-023-00825-y VL - 11 SP - SN - 1573-1502 KW - Renewable energy KW - Wind energy KW - Air pollution KW - Morbidity KW - Emergency department visits ER - TY - JOUR TI - Correction to “Techno-Economic and Life Cycle Assessment of Enhanced Rock Weathering: A Case Study from the Midwestern United States” AU - Zhang, Bingquan AU - Kroeger, Jennifer AU - Planavsky, Noah AU - Yao, Yuan T2 - Environmental Science & Technology AB - ADVERTISEMENT RETURN TO ISSUEPREVAddition/CorrectionNEXTORIGINAL ARTICLEThis notice is a correctionCorrection to “Techno-Economic and Life Cycle Assessment of Enhanced Rock Weathering: A Case Study from the Midwestern United States”Bingquan ZhangBingquan ZhangMore by Bingquan Zhang, Jennifer KroegerJennifer KroegerMore by Jennifer Kroeger, Noah PlanavskyNoah PlanavskyMore by Noah Planavsky, and Yuan Yao*Yuan Yao*[email protected]More by Yuan Yaohttps://orcid.org/0000-0001-9359-2030Cite this: Environ. Sci. Technol. 2023, 57, 50, 21483–21484Publication Date (Web):December 4, 2023Publication History Received4 November 2023Published online4 December 2023Published inissue 19 December 2023https://doi.org/10.1021/acs.est.3c09200Copyright © 2023 American Chemical SocietyRequest reuse permissions This publication is free to access through this site. Learn MoreArticle Views294Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail PDF (1 MB) Get e-Alertsclose Get e-Alerts DA - 2023/12/19/ PY - 2023/12/19/ DO - 10.1021/acs.est.3c09200 UR - https://doi.org/10.1021/acs.est.3c09200 ER - TY - JOUR TI - Vapor phase synthesis of metal-organic frameworks on a nanofibrous aerogel creates enhanced functionality AU - Rahmanian, Vahid AU - Ebrahim, Muhammed Ziauddin Ahmad AU - Razavi, Seyedamin AU - Abdelmigeed, Mai AU - Barbieri, Eduardo AU - Menegatti, Stefano AU - Parsons, Gregory N. AU - Li, Fanxing AU - Pirzada, Tahira AU - Khan, Saad A. T2 - JOURNAL OF MATERIALS CHEMISTRY A AB - Vapor-phase synthesis of metal–organic frameworks (MOFs) on nanofibrous aerogels provides a hierarchically porous and mechanically robust material platform for use in a multitude of applications, from carbon dioxide capture to heavy metal removal. DA - 2023/11/6/ PY - 2023/11/6/ DO - 10.1039/d3ta05299k VL - 11 SP - SN - 2050-7496 ER - TY - JOUR TI - Forest-Based Employment in the Southern United States amidst the COVID-19 Pandemic: A Causal Inference Analysis AU - Chizmar, Stephanie AU - Parajuli, Rajan AU - Bruck, Sonia AU - Frey, Gregory AU - Sills, Erin T2 - FOREST SCIENCE AB - Abstract In response to the COVID-19 pandemic, some governments instituted mandatory stay-at-home policies. As these policies made exceptions for essential industries such as the forest sector, it is not clear a priori whether and how these policies would affect forest-based employment. This study examined the effect of mandatory stay-at-home orders on employment in the forest sector in forest dependent counties in eleven southern states in the United States. We estimated panel event study models in addition to difference-in-difference models to evaluate the policy effects with respect to initial treatment as well as average effects to the treated counties during treatment. We found that employment in wood product manufacturing was lower on average in counties under a lockdown order compared with employment in counties without an active order. We also found that employment in the aggregate forest sector in counties that implemented the policy was significantly lower than employment in counties without the policy up to 9 months following initial enactment compared with the underlying difference between treated and control counties one month prior to treatment. Overall, our findings suggest that lockdown policies had a limited effect on employment in essential industries such as wood-based manufacturing sectors in the southern states. Study Implications: This study uses causal inference techniques to assess the effect of lockdown orders on forest-based employment in 11 southern states. Results suggest effects of lockdown orders were limited to the aggregate forest sector and wood product manufacturing, likely due to the rapid designation of the sector as essential and the reduced production of sawmills. The other industries within the sector were not significantly affected, implying that industries designated as essential may be more resilient to short-term shocks. These findings can be used to inform discussions on potential policy responses to future disasters, including how different interventions interact with one another. DA - 2023/11/1/ PY - 2023/11/1/ DO - 10.1093/forsci/fxad042 VL - 11 SP - SN - 1938-3738 KW - stay-at-home orders KW - difference-in-difference KW - two-way fixed effect KW - panel event study KW - forest-dependent counties ER - TY - JOUR TI - Vulnerability of wells in unconfined and confined aquifers to modern contamination from flood events AU - Rudd, Hayden AU - Neal, Andy AU - Genereux, David P. AU - Shea, Damian AU - Nichols, Elizabeth Guthrie T2 - SCIENCE OF THE TOTAL ENVIRONMENT AB - Groundwater is a primary potable water supply for coastal North Carolina (NC), but the increased intensity of extreme rainfall events and floods may exacerbate surface and subsurface processes that contribute anthropogenic chemicals to wells in the major confined aquifers of this region. We evaluated groundwater for organic chemicals of emerging concern (CEC) and the presence of tritium using flooded and not-flooded wells in the NC Department of Environmental Quality well monitoring network across the NC Coastal Plain. Flooded wells experienced standing water around the well casing at least once during the study period. Tritium concentrations, which indicate modern water presence (water recharged after 1953), were significantly greater in groundwater from flooded wells than not-flooded wells. In confined aquifers, modern water was detected at greater depths in flooded wells (206 m) than not-flooded wells (100 m). Suspect-screening high resolution mass spectrometry (HRMS) analysis of 150 groundwater samples yielded a total of 382 unique organic chemicals. Each groundwater sample contained, on average, 19 tentatively identified chemicals from the NIST 20 mass spectral database (M1) and 9 USEPA ToxCast chemicals. The number of tentatively-identified chemicals per sample was not significantly different among aquifers demonstrating the pervasive presence of the detected CECs in unconfined and confined aquifers. The presence of modern water in groundwater from flooded wells coincided with higher detection frequencies of certain organic contaminant classes, particularly pharmaceuticals, food additives, and regulated aromatic hydrocarbons. These results indicate that wells in both unconfined and confined aquifers are susceptible to modern water contamination during flood events; this finding has critical public health implications for coastal communities. DA - 2023/11/25/ PY - 2023/11/25/ DO - 10.1016/j.scitotenv.2023.165729 VL - 901 SP - SN - 1879-1026 KW - HRMS KW - Tritium KW - Groundwater KW - Flood KW - Confined aquifers KW - Chemicals of emerging concern ER - TY - JOUR TI - Interlaboratory study assessing the analysis of supercapacitor electrochemistry data AU - Gittins, Jamie W. AU - Chen, Yuan AU - Arnold, Stefanie AU - Augustyn, Veronica AU - Balducci, Andrea AU - Brousse, Thierry AU - Frackowiak, Elzbieta AU - Gomez-Romero, Pedro AU - Kanwade, Archana AU - Koeps, Lukas AU - Jha, Plawan Kumar AU - Lyu, Dongxun AU - Meo, Michele AU - Pandey, Deepak AU - Pang, Le AU - Presser, Volker AU - Rapisarda, Mario AU - Rueda-Garcia, Daniel AU - Saeed, Saeed AU - Shirage, Parasharam M. AU - Slesinski, Adam AU - Soavi, Francesca AU - Thomas, Jayan AU - Titirici, Maria-Magdalena AU - Wang, Hongxia AU - Xu, Zhen AU - Yu, Aiping AU - Zhang, Maiwen AU - Forse, Alexander C. T2 - JOURNAL OF POWER SOURCES AB - Supercapacitors are fast-charging energy storage devices of great importance for developing robust and climate-friendly energy infrastructures for the future. Research in this field has seen rapid growth in recent years, therefore consistent reporting practices must be implemented to enable reliable comparison of device performance. Although several studies have highlighted the best practices for analysing and reporting data from such energy storage devices, there is yet to be an empirical study investigating whether researchers in the field are correctly implementing these recommendations, and which assesses the variation in reporting between different laboratories. Here we address this deficit by carrying out the first interlaboratory study of the analysis of supercapacitor electrochemistry data. We find that the use of incorrect formulae and researchers having different interpretations of key terminologies are major causes of variability in data reporting. Furthermore we highlight the more significant variation in reported results for electrochemical profiles showing non-ideal capacitive behaviour. From the insights gained through this study, we make additional recommendations to the community to help ensure consistent reporting of performance metrics moving forward. DA - 2023/11/30/ PY - 2023/11/30/ DO - 10.1016/j.jpowsour.2023.233637 VL - 585 SP - SN - 1873-2755 KW - Data analysis KW - Electrochemical energy storage KW - Supercapacitors ER - TY - JOUR TI - A Novel Real-Time Control Approach for Sparse and Safe Frequency Regulation in Inverter Intensive Microgrids AU - Zhang, Junhui AU - Ding, Lizhi AU - Lu, Xiaonan AU - Tang, Wenyuan T2 - IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS AB - This article developed a novel real-time control approach for the sparse and safe frequency regulation in inverter intensive microgrids (MGs). In the scenario, the inverters and external grids are expected to be synchronized with a desired frequency. To this end, the active power set-point acting as a control from a high-level controller is designed while considering two important performance metrics, namely “sparsity” and “safety”, which are to reduce the information exchange between controllers and ensure that the frequency remains in safe regions during the whole operation process. Our proposed control design framework allows the sparse linear feedback controller (SLFC) to be unified with a family of conditions for safe control using control barrier functions. A quadratic programming (QP) problem is then constructed, and the real-time control policy is obtained by solving the QP problem. Further, we also found that the proposed real-time control depends on the cross-layer communication network topology, which is the union of the one between controllers from SLFC and that determined by the power flow network. The proposed control approach has been validated through extensive case studies. DA - 2023/9// PY - 2023/9// DO - 10.1109/TIA.2023.3291353 VL - 59 IS - 5 SP - 5550-5558 SN - 1939-9367 KW - Control barrier function KW - frequency regulation KW - inverter intensive microgrid KW - quadratic programming KW - sparse control ER - TY - JOUR TI - Determination of Parameters of Symmetrical Six-Phase Permanent Magnet Synchronous Machines AU - Das, Partha Pratim AU - Satpathy, Subhransu AU - Bhattacharya, Subhashish AU - Veliadis, Victor AU - Deshpande, Uday AU - Bhargava, Brij T2 - 2023 IEEE INTERNATIONAL ELECTRIC MACHINES & DRIVES CONFERENCE, IEMDC AB - This paper presents offline methods to determine different parameters of Symmetrical Six-Phase (SSP) Permanent Magnet Synchronous Machines (PMSMs). Accurate estimations of different parameters are crucial for proper machine modeling, control, and performance estimations. This paper discusses two offline methods to accurately determine different inductances and the stator resistance of SSP-PMSMs using a single-phase AC source. A method to calculate the Permanent Magnet (PM) flux linkage is also discussed. Machine parameters of a high-speed, low-inductance SSP-PMSM are determined using both methods. The determined parameters are compared with Finite Element Analysis (FEA)-based simulation results and the results are presented in this paper. DA - 2023/// PY - 2023/// DO - 10.1109/IEMDC55163.2023.10238906 SP - KW - Six-phase PMSM KW - symmetrical six-phase KW - multiphase machines KW - inductance measurement KW - parameter determination KW - high-speed PMSM KW - equivalent circuit ER - TY - JOUR TI - Vector-Based Open-Circuit Fault Diagnosis Technique for a Three-Phase DAB Converter AU - Rastogi, Sagar Kumar AU - Shah, Suyash Sushilkumar AU - Singh, Brij N. AU - Bhattacharya, Subhashish T2 - IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS AB - A three-phase dual active bridge (DAB3) has become a popular topology for high-power dc–dc conversion. An open-circuit fault in DAB3 can produce a dc bias in its phase currents, which can saturate the transformer, resulting in the device overcurrents and catastrophic failure. This letter proposes a robust fault diagnosis technique to detect the fault and identify the faulty transistor within three to four switching cycles with high noise immunity. The technique requires low-bandwidth current sensing only on one side of the transformer, providing a cost and design benefit, especially in the case of a high-gain high-power converter, where the currents can be sensed on the low-current side. Moreover, in dual-active-bridge circuits, where current sensing is a norm for control and protection purposes, the proposed algorithm can be deployed as a software update on the existing hardware and does not require any hardware modifications. Experimental verification results of the proposed technique on a 5-kW DAB3 hardware prototype are also presented. DA - 2023/9/18/ PY - 2023/9/18/ DO - 10.1109/TIE.2023.3312430 VL - 9 SP - SN - 1557-9948 KW - Circuit faults KW - Fault diagnosis KW - Transistors KW - Sensors KW - Bridge circuits KW - Switches KW - Hardware KW - DC-DC converter KW - detection KW - diagnosis KW - dual active bridge (DAB) KW - fault KW - open-circuit fault KW - three phase KW - vector ER - TY - JOUR TI - A Distributed Control Method With Seamless Hot Swap Capability for Generic DC Microgrids AU - Sharma, Shrivatsal AU - Iyer, Vishnu Mahadeva AU - Bhattacharya, Subhashish T2 - IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS AB - This article proposes a distributed secondary control method for droop-controlled dc microgrid (MG) systems with ring or mesh configurations. The control method achieves accurate current sharing and improved load voltage regulation than the conventional droop method by using the bus voltage information of any bus of the dc MG system. The secondary controllers are implemented locally at each converter, thus ensuring a distributed control. The proposed method requires communication of only one signal per communication link and it needs less number of communication links than the state-of-the-art distributed secondary control methods. The method also offers a seamless hot swap capability of a converter as there is no interdependence between the secondary controllers of the converters. The effectiveness of the proposed method is validated using switching simulations and hardware-based experiments on different configurations of dc MG systems. DA - 2023/9/28/ PY - 2023/9/28/ DO - 10.1109/TIE.2023.3317835 VL - 9 SP - SN - 1557-9948 KW - DC microgrid KW - distributed control KW - droop control KW - secondary control KW - stability KW - current sharing accuracy ER - TY - JOUR TI - Tapping the Unused Energy Potential of Solar Water Pumps in India AU - Keskar, Aditya AU - Soni, Vivek AU - Shukla, Jaya AU - Jain, Sachin AU - Ghosh, Subhojit AU - Patel, Ramnarayan AU - Johnson, Jeremiah X. T2 - ENVIRONMENTAL SCIENCE & TECHNOLOGY AB - India seeks to deploy millions of solar water pumps to farmers who often lack access to electricity or face an unreliable power supply. Improving the use of this technology can bolster sustainable agriculture and expand clean energy services. We investigate farm-level impacts and opportunities with primary survey data (n = 292 farmers) and a large real-time pump operational data set (n = 1106 pumps). By modeling the potential solar generation of off-grid solar water pumps, we estimate 300-400 kWh/month of unutilized solar energy per pumping system, representing up to 95% of potential generation. While farmers report increased revenues and ease of pump operation, unsolved challenges concerning the lack of panel cleaning and tracking remain. Pump operational data show pump usage in the summer and monsoon seasons and an expansion of irrigation to grow crops in the winter. Relative to emissions associated with the use of diesel pumps, solar pumps that are highly utilized reduced life cycle CO2-eq emissions by 93% on average, while the pumping systems with the lowest use result in a net increase of 26% relative to the diesel alternatives. Based on observed usage rates, approximately 70% of pumps had positive environmental benefits. The high share of unutilized solar energy provides a significant opportunity to use the energy for nonpumping purposes. DA - 2023/9/12/ PY - 2023/9/12/ DO - 10.1021/acs.est.3c02378 VL - 57 IS - 38 SP - 14173-14181 SN - 1520-5851 KW - solar water pumps KW - sustainable development KW - life cycle emissions KW - South Asia KW - food-energy-waternexus KW - irrigation KW - solar energy ER - TY - JOUR TI - Adopting Dynamic VAR Compensators to Mitigate PV Impacts on Unbalanced Distribution Systems AU - Lee, Han Pyo AU - Dsouza, Keith AU - Chen, Ke AU - Lu, Ning AU - Baran, Mesut E. T2 - IEEE ACCESS AB - The growing integration of distributed energy resources into distribution systems poses challenges to voltage regulation. Dynamic VAR Compensators (DVCs) are a new generation of power electronics-based Volt/VAR compensation devices designed to address voltage issues in distribution systems with a high penetration of renewable generation resources. Currently, the IEEE Std. 1547 based Volt/VAR Curve (VV-C) is widely used as the local control scheme for controlling a DVC. However, the effectiveness of this scheme is not well documented, and there is limited literature on alternative control and placement schemes that can maximize the effective use of a DVC. In this paper, we propose an optimal dispatch and control mechanism to enhance the conventional Volt/VAR Curve (VV-C) based localized DVC control. First, we establish a multi-objective optimization framework to identify the optimal dispatch strategy and suitable placement for the DVC. Next, we introduce two supervisory control strategies to determine the appropriate instances for adjusting the VV-C when the operating condition changes. The outlined scheme comprises two primary stages: time segmentation and VV-C fitting.Within this framework, each time segment aims to produce optimized Q-V trajectories. The proposed method is tested on a modified IEEE 123-bus test system using OpenDSS for a wide range of operating scenarios, including sunny and cloudy days. Simulation results demonstrate that the proposed scheme effectively reduces voltage variations compared to the standard VV-C specified in IEEE Std. 1547. DA - 2023/// PY - 2023/// DO - 10.1109/ACCESS.2023.3315601 VL - 11 SP - 101514-101524 SN - 2169-3536 KW - DER impact mitigation KW - distribution system KW - dynamic VAR compensator (DVC) KW - high penetration PV KW - smart inverter KW - Volt/VAR control ER - TY - JOUR TI - Should we invest in nuclear? AU - Fell, Harrison T2 - JOULE AB - In this issue of Joule, Haywood, Leroutier, and Pietzcker outline reasons why investing in nuclear is counterproductive for meeting decarbonization goals. I review these arguments against nuclear and provide some possible explanations as to why we do, and should, see a relatively small amount of investment in new nuclear generation. In this issue of Joule, Haywood, Leroutier, and Pietzcker outline reasons why investing in nuclear is counterproductive for meeting decarbonization goals. I review these arguments against nuclear and provide some possible explanations as to why we do, and should, see a relatively small amount of investment in new nuclear generation. Why investing in new nuclear plants is bad for the climateHaywood et al.JouleJuly 21, 2023In BriefInvestments in new nuclear power plants are bad for the climate due to high costs and long construction times. Given the urgency of climate change mitigation, which requires reducing emissions from the EU electricity grid to almost zero in the 2030s, preference should be given to the cheapest technology that can be deployed fastest. On both costs and speed, renewable energy sources beat nuclear. Every euro invested in new nuclear plants delays decarbonization compared to investments in renewable power. Full-Text PDF DA - 2023/8/16/ PY - 2023/8/16/ DO - 10.1016/j.joule.2023.07.007 VL - 7 IS - 8 SP - 1679-1681 SN - 2542-4351 ER - TY - JOUR TI - Accelerating China's power sector decarbonization can save lives: integrating public health goals into power sector planning decisions AU - Luo, Qian AU - Garcia-Menendez, Fernando AU - Lin, Jiang AU - He, Gang AU - Johnson, Jeremiah X. T2 - ENVIRONMENTAL RESEARCH LETTERS AB - Abstract China, the world’s largest greenhouse gas emitter in 2022, aims to achieve carbon neutrality by 2060. The power sector will play a major role in this decarbonization process due to its current reliance on coal. Prior studies have quantified air quality co-benefits from decarbonization or investigated pathways to eliminate greenhouse gas emissions from the power sector. However, few have jointly assessed the potential impacts of accelerating decarbonization on electric power systems and public health. Additionally, most analyses have treated air quality improvements as co-benefits of decarbonization, rather than a target during decarbonization. Here, we explore future energy technology pathways in China under accelerated decarbonization scenarios with a power system planning model that integrates carbon, pollutant, and health impacts. We integrate the health effects of power plant emissions into the power system decision-making process, quantifying the public health impacts of decarbonization under each scenario. We find that compared with a reference decarbonization pathway, a stricter cap (20% lower emissions than the reference pathway in each period) on carbon emissions would yield significant co-benefits to public health, leading to a 22% reduction in power sector health impacts. Although extra capital investment is required to achieve this low emission target, the value of climate and health benefits would exceed the additional costs, leading to $824 billion net benefits from 2021 to 2050. Another accelerated decarbonization pathway that achieves zero emissions five years earlier than the reference case would result in lower net benefits due to higher capital costs during earlier decarbonization periods. Treating air pollution impacts as a target in decarbonization can further mitigate both CO 2 emissions and negative health effects. Alternative low-cost solutions also show that small variations in system costs can result in significantly different future energy portfolios, suggesting that diverse decarbonization pathways are viable. DA - 2023/10/1/ PY - 2023/10/1/ DO - 10.1088/1748-9326/acf84b VL - 18 IS - 10 SP - SN - 1748-9326 KW - power systems KW - decarbonization KW - air quality KW - health impacts ER - TY - JOUR TI - Bidirectional Three-phase Current Source Converter based Buck-boost AC/DC System using Bidirectional Switches AU - Narwal, Ramandeep AU - Bhattacharya, Subhashish AU - Baliga, B. Jayant AU - Hopkins, Douglas C. T2 - 2023 IEEE TRANSPORTATION ELECTRIFICATION CONFERENCE & EXPO, ITEC AB - The 1.2 kV 4H-SiC BiDirectional Field Effect Transistor (BiDFET) is the first monolithic SiC bidirectional switch, which offers a lower voltage drop and semiconductor devices count alternative to the reverse-voltage-blocking (RB) switch used in the current-source converters (CSC). The bidirectional switch based CSC also allows DC-link current reversal for bidirectional power flow and provides multiple system-level benefits in a buck-boost AC/DC system consisting of buck-type DC/DC converter and CSC. This paper discusses the selection of buck converter duty cycle and CSC modulation index for the system's buck-boost operation with a wide variation in DC voltage. CSC modulation schemes categorized based on the number of hard-turn-on transitions per switching cycle are also analyzed along with the three-step and four-step commutation schemes that are essential for the CSC commutation cells. Finally, the different schemes are evaluated and compared through the experimental results of a 10 kW, 480 $\mathbf{V}_{\mathbf{RMS},\mathbf{LL}}/$ (400 - 800) V AC/DC system. DA - 2023/// PY - 2023/// DO - 10.1109/ITEC55900.2023.10186945 SP - SN - 2473-7631 KW - Bidirectional switches KW - four-quadrant switches KW - current source inverter KW - interleaved buck converter KW - modulation KW - commutation KW - SiC bidirectional FET KW - BiDFET KW - CSI KW - CSC ER - TY - JOUR TI - Dual-Band Electrochromism in Hydrous Tungsten Oxide AU - Fortunato, Jenelle AU - Zydlewski, Benjamin Z. AU - Lei, Ming AU - Holzapfel, Noah P. AU - Chagnot, Matthew AU - Mitchell, James B. AU - Lu, Hsin-Che AU - Jiang, De-en AU - Milliron, Delia J. AU - Augustyn, Veronica T2 - ACS PHOTONICS AB - The independent modulation of visible and near-infrared light by a single material, termed dual-band electrochromism, is highly desirable for smart windows to enhance the energy efficiency of buildings. Tungsten oxides are commercially important electrochromic materials, exhibiting reversible visible and near-infrared absorption when electrochemically reduced in an electrolyte containing small cations or protons. The presence of structural water in tungsten oxides has been associated with faster electrochromic switching speeds. Here, we find that WO3·H2O, a crystalline hydrate, exhibits dual-band electrochromism unlike the anhydrous WO3. This provides a heretofore unexplored route to tune the electrochromic response of tungsten oxides. Absorption of near-infrared light is achieved at low Li+/e– injection, followed by the absorption of visible light at higher Li+/e– injection as a result of an electrochemically induced phase transition. We propose that the dual-band modulation is possible due to the more open structure of WO3·H2O as compared to WO3. This facilitates a more extended solid-solution Li+ insertion regime that benefits the modulation of near-infrared radiation via plasmon absorption. Higher degrees of Li+/e– insertion lead to polaronic absorption associated with localized charge storage. These results inform how structural factors influence the electrochemically induced spectral response of transition-metal oxides and the important role of structural water beyond optical switching speed. DA - 2023/9/1/ PY - 2023/9/1/ DO - 10.1021/acsphotonics.3c00921 SP - SN - 2330-4022 KW - electrochromism KW - tungsten oxide KW - structuralwater KW - spectroelectrochemistry KW - plasmon absorption ER - TY - JOUR TI - Methodologies of Cascading to Realize High Voltage Cascaded Super Cascode Power Switch AU - Mehrotra, Utkarsh AU - Hopkins, Douglas C. T2 - IEEE Journal of Emerging and Selected Topics in Power Electronics AB - Development of high-voltage (HV) high-current (HC) power semiconductor devices is limited due to relatively low yield, expensive material and fabrication costs, and retracted dynamic performance from paralleling many HV, low-current (LC) devices. An alternative is a serial connection of low-voltage (LV) HC devices to create a supercascode power switch (SCPS). This article describes a methodology of cascading SCPSs to realize an even higher voltage cascaded supercascode power switch (CSCPS), which optimizes switching through multilayered cascades of normally-on devices, e.g., JFETs or depletion-mode GaN HEMTs. The method provides a topology optimization of cascaded cells dependent on switching losses, net charge reduction in network capacitors, and avalanche energy management. Simulation and test results are provided for a single-layer “2S-3C” 6-kV CSCPS. The 6-kV JFET CSCPS showed 408- $\text{m}\Omega $ ON-resistance, leakage current of 0.7 mA at 4.8 kV, and 40-ns rise with 30-ns fall in current at 4 kV/20 A. DA - 2023/// PY - 2023/// DO - 10.1109/JESTPE.2023.3314025 VL - 11 IS - 6 SP - 5853-5862 SN - 2168-6785 UR - https://doi.org/10.1109/JESTPE.2023.3314025 KW - JFET circuits KW - medium voltage (MV) KW - SiC device applications KW - supercascode structure KW - voltage balancing ER - TY - JOUR TI - Energy savings and life cycle cost analysis of advanced double skin facade system applied to old apartments in South Korea AU - Yoon, Yeobeom AU - Seo, Byeongmo AU - Mun, Junghyun AU - Cho, Soolyeon T2 - JOURNAL OF BUILDING ENGINEERING AB - South Korea is one of the most densely populated countries in the world, and the population density in urban areas is much higher among others. Apartments are the most common form of residential buildings due to their high population density. More than 60% of domestic residential buildings are apartments, with more than 10 million households. The high population density is a problem that has long plagued South Korea because more than 45% of apartments are old apartments that are more than 20 years old. Old apartment buildings have low thermal performance that results in lots of energy consumption. Balconies, which worked as a thermal buffer, are also being removed by residents to expand indoor space. According to the green remodeling project supported by the Korean government, the typical retrofitting method is replacing external windows with the high-efficiency window in old apartments in South Korea. This paper proposes a retrofitting method using an extended double-skin façade (DSF) system that replaces exterior windows and acts as a thermal buffer. The simulation model is developed with the EnergyPlus simulation program to conduct energy performance analyses. The simulation model has been calibrated using actual experimental data collected between October 1, 2019, and January 15, 2020. Results show that the cooling, heating, and lighting energy can be reduced up to 44.1% by fully utilizing electric energy generated by solar PV panels integrated with the DSF system. The payback period is about 15 years based on the energy price provided by the utility company. Although the payback period is long, it has great potential of energy savings and CO2 emission reductions. The DSF system should be considered as a way of renovation, considering other factors such as increased real estate values and energy cost increases in the future. DA - 2023/7/15/ PY - 2023/7/15/ DO - 10.1016/j.jobe.2023.106535 VL - 71 SP - SN - 2352-7102 KW - Double skin facade system KW - Retrofitting KW - Energy savings KW - Carbon dioxide emission KW - Life cycle cost analysis ER - TY - JOUR TI - Techno-Economic and Life Cycle Assessment of Enhanced Rock Weathering: A Case Study from the Midwestern United States AU - Zhang, Bingquan AU - Kroeger, Jennifer AU - Planavsky, Noah AU - Yao, Yuan T2 - Environmental Science & Technology AB - Enhanced rock weathering (ERW) is a carbon dioxide removal (CDR) strategy for combating climate change. The CDR potentials of ERW have been assessed at the process and national/global levels, but the environmental and economic implications of ERW have not been fully quantified for U.S. applications with real-world supply chain considerations. This study develops an optimization-based, integrated life cycle assessment and techno-economic analysis framework for ERW, which is demonstrated by a case study applying mining waste to croplands in the Midwestern U.S. The case study explores maximum transportation distances for intermodal transportation at varied mineral CDR yields and costs, informing supply chain design for economically viable ERW. ERW costs (US$45 to 472/tonne of net CO2e captured) and cradle-to-farm gate GHG emissions (41 to 359 kg CO2e/tonne of CO2e captured) are estimated based on a range of CDR yields and by transportation distances to and from two Midwest port destinations: Chicago and Duluth. Our sensitivity analysis identifies CDR yields, and transportation modes and distances as driving factors for result variations. Our study reveals the importance of ERW supply chain design and provides an example of U.S. CDR implementation. Our framework and findings can be applied to other regional ERW projects. DA - 2023/9/19/ PY - 2023/9/19/ DO - 10.1021/acs.est.3c01658 UR - https://doi.org/10.1021/acs.est.3c01658 ER - TY - JOUR TI - Environmental impacts of cotton and opportunities for improvement AU - Zhang, Zhenggui AU - Huang, Jing AU - Yao, Yuan AU - Peters, Gregory AU - Macdonald, Ben AU - Rosa, Angela Daniela La AU - Wang, Zhanbiao AU - Scherer, Laura T2 - Nature Reviews Earth & Environment DA - 2023/9/5/ PY - 2023/9/5/ DO - 10.1038/s43017-023-00476-z UR - https://doi.org/10.1038/s43017-023-00476-z ER - TY - JOUR TI - Design Considerations of a 3.3 kV SiC-based Reverse Voltage Blocking Module for Current Source Inverter Application AU - Narasimhan, Sneha AU - Sisson, Colton AU - Leslie, Scott AU - Parmar, Keval AU - Rastogi, Sagar Kumar AU - Bhattacharya, Subhashish T2 - 2023 IEEE APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION, APEC AB - This paper presents the design and development of a 3.3 kV silicon carbide (SiC) based reverse voltage blocking half-bridge module for the first time. This low inductance module can build a single-phase or a three-phase current source inverter (CSI). The module comprises of a SiC-MOSFET (3.3 kV/50 A die) and a SiC-MPS diode (3.3 kV/50 A die) to form a 3.3 kV SiC-based current switch in the half-bridge configuration. The static characterization of the current switch (CS) is performed, and a double pulse test circuit is used to verify the switching performance of the developed module. Additionally, the inverter efficiency is estimated for a 30 kW three-phase CSI for a motor drive application, using the obtained static and dynamic characterization results. The impact of the module inductances on the switch voltage and currents is discussed, thus illustrating the importance of a module-based design for CSI applications. DA - 2023/// PY - 2023/// DO - 10.1109/APEC43580.2023.10131381 SP - 350-357 SN - 1048-2334 KW - Current source inverter (CSI) KW - current switch KW - half-bridge KW - module KW - packaging KW - reverse-voltage blocking switch KW - three-phase inverter ER - TY - JOUR TI - A Novel Transformer Leakage Energy Recovery Active Clamp Control Technique for High Power AC/DC Flyback Converters AU - Kokkonda, Raj Kumar AU - Beddingfield, Richard AU - Bhattacharya, Subhashish AU - Carsten, Bruce AU - Varga, Bo T2 - 2023 IEEE APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION, APEC AB - A novel twin-pulse active clamp has been proposed for flyback converters that can efficiently recover the transformer leakage energy and route it to the output with reduced clamp current ratings and clamp capacitance compared to existing active clamp methods. This extends the application power range for ac/dc flyback converters by enabling a cost-effective leakage energy recovery method for high-power applications. In the case of a 2.5 kW flyback converter, the proposed clamp offers a potential reduction of the required clamp capacitance by 500x and the clamp current by more than 2x at the expense of a higher peak switch voltage stress when compared to an equivalent conventional active clamp. The operating principle and the design criteria for the proposed clamp method are discussed. Experimental results for a 2.5 kW ac/dc flyback converter prototype with the proposed clamp have been presented, validating the clamp operation. Its performance and efficiency improvement compared to a dissipative clamp with active discharge has also been evaluated over the entire operating region. DA - 2023/// PY - 2023/// DO - 10.1109/APEC43580.2023.10131320 SP - 1238-1245 SN - 1048-2334 KW - Active clamp KW - PFC KW - flyback converter KW - ac/dc KW - leakage energy recovery KW - non-complementary control ER - TY - JOUR TI - Performance Comparison of 10 kV and Series-connected 3.3 kV SiC MOSFETs based VSCs for MV Grid Interfacing Applications AU - Kokkonda, Raj Kumar AU - Parashar, Sanket AU - Bhattacharya, Subhashish T2 - 2023 IEEE APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION, APEC AB - The latest HV SiC devices can significantly improve the efficiency and power density of MV grid interfacing converters. A VSC (Voltage Source Converter) with 7.2 kV dc bus can directly interface with a 4160 V grid which can be realized in a 2-level configuration using a 10 kV blocking switch. HV SiC devices such as 6.5 kV and 10 kV SiC MOSFETs are still in their nascency and being used in research applications, whereas 3.3 kV SiC MOSFETs have already been qualified for commercial applications by multiple vendors. In this regard, an equivalent 10 kV switch formed by series connection of three 3.3 kV SiC MOSFETs has been proposed as a potential alternative, and it has been quantitatively compared to a single 10 kV SiC MOSFET. Normalized device parameters have been considered in both cases for a fair comparison. Two types of 10 kV $120\ \mathrm{m}\Omega$ switching cells have been realized through series connected 3.3 kV $40\ \mathrm{m}\Omega$ SiC MOSFETs and parallel connected 10 kV $350\ \mathrm{m}\Omega$ SiC MOSFETs for effective power loss comparison. Experimentally determined device conduction and switching losses have been employed for further efficiency and loss modeling of 3-phase VSCs using both switching cells. The power loss and efficiency trends with load and switching frequency variation have been presented for both cases. The converter power processing capability dependence on the switching frequency has also been compared for both cases. DA - 2023/// PY - 2023/// DO - 10.1109/APEC43580.2023.10131385 SP - 995-1002 SN - 1048-2334 KW - SiC MOSFET KW - medium voltage KW - series connection KW - 3.3 kV KW - 10 kV KW - loss comparison KW - voltage balancing ER - TY - JOUR TI - Control of a Dual-Active-Bridge DC-DC Converter in a MV Grid-Compliant Solid-State Transformer Based DC Fast Charger AU - Sharma, Shrivatsal AU - Prabowo, Yos AU - Bhattacharya, Subhashish T2 - 2023 IEEE APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION, APEC AB - A solid-state transformer (SST) system comprising cascaded H-bridge (CHB) and dual-active bridge (DAB) converters is a promising solution for a DC fast charger. This paper primarily focuses on the control design of the DAB converters for this system and utilizes a dual-loop based control scheme. The dual-loop consists of central voltage and inner current control loops. The inner current loops are needed to achieve current sharing between the paralleled DABs. In this paper, the inner current loop uses the DC output current of each DAB as the feedback signal. Thus, the control structure implemented in this paper is more cost-effective and computationally less intensive than the traditional approach of using a high-frequency current as the feedback signal. To provide a well-regulated output DC bus voltage, the control design considers the input disturbance due to the double-line frequency component in the DC-link voltage and the output disturbance due to load throw-off scenarios. An analytical model is derived for the complete dual-loop control structure of the DAB converter. The model evaluates the impact of disturbances due to the double-line frequency component and load throw-off scenarios on output DC bus voltage for different bandwidth combinations of the central voltage and inner current loops. Experimental results validating the analytical model are shown and discussed using a prototype of an SST system. DA - 2023/// PY - 2023/// DO - 10.1109/APEC43580.2023.10131314 SP - 3147-3153 SN - 1048-2334 KW - Cascaded H-Bridge KW - DC Fast charger KW - Dual-Active-Bridge KW - Dual-loop control KW - SST ER - TY - JOUR TI - Switching Loss Analysis of Three-Phase Three-Level Neutral Point Clamped Converter Pole Enabled by Series-Connected 10 kV SiC MOSFETs AU - Kolli, Nithin AU - Parashar, Sanket AU - Kokkonda, Raj Kumar AU - Bhattacharya, Subhashish AU - Veliadis, Victor T2 - 2023 IEEE APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION, APEC AB - The recent advancement in the technology of SiC MOSFETs has spurred interest in designing compact and high switching frequency (10–20 kHz) power converters. However, grid-integration of these power converters at medium voltage (MV) scale would require a conventional transformer. With the development of new high voltage (HV) 10 kV and 15 kV SiC MOSFETs, these converters can directly interface with medium voltage (MV) grids without the need for line-frequency transformers, using simple two-level and three-level topologies. The application of these devices is currently being explored in all MV Applications (8 kV to 30 kV) like Solid State Transformer, MV Drives, Power Conditioning Systems, and MVDC isolators. This paper discusses application of 10 kV SiC MOSFETs and JBS Diodes for enabling Asynchronous Microgrid Power Conditioning System (AMPCS). This medium voltage power converter is enabled by series-connection of devices, in a Three-Level Neutral Point Clamped (3L-NPC) configuration. The voltage balancing of these series-connected devices is achieved by using R C-snubbers. This paper addresses the different conduction modes and switching sequences of a 3L-NPC pole, which is used as building block for the three-phase converter. The switching loss analysis, for various snubber values, is presented for the MOSFETs and the clamping diodes along with experimental results. This research helps in providing an overview of switching losses that are disspated through the device (and heatsink) and through the snubber resistor in a 3L-NPC convertor pole. DA - 2023/// PY - 2023/// DO - 10.1109/APEC43580.2023.10131392 SP - 2353-2360 SN - 1048-2334 KW - SiC MOSFETs KW - JBS Diodes KW - Medium Voltage KW - Active Front End Convertrer KW - Microgrid KW - Series connection KW - Grid Forming Converter KW - Voltage Source Converter KW - series connection KW - snubbers KW - voltage balancing ER - TY - JOUR TI - Novel Control for Active Power Compensation using DSCC-MMC based ES-STATCOM AU - Nath, Harshit AU - Isik, Semih AU - Burugula, Vasishta AU - Bhattacharya, Subhashish T2 - 2023 IEEE APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION, APEC AB - In recent years, modular multilevel converters (MMC) have gained popularity for high-power applications such as in flexible AC transmission systems (FACTS) and High Voltage DC (HVDC) applications, due to their scalability and modularity along with high efficiency in handling high-power and high voltage needs of the power grid. In the same domain of applications, one such usage of the MMC-based system is the integration of energy storage with static synchronous compensator (STATCOM) technology (known as ES-STATCOM) for providing active power compensation along with reactive power support to the grid. This paper introduces a novel dynamic model-based control approach to the MMC-based ES-STATCOM for the integration of energy sources with the power grid. The design of various controller elements is based on detailed harmonic evaluations for both dynamic and steady-state operation modes. The design of the circulating current control adds second-harmonic computation of the modulation indexes for the suppression of second-harmonic circulating current. This approach further improves the converter's performance by reducing the fluctuation in the capacitor voltages and eventually the losses. Finally, the operating range of the MMC-based ES-STATCOM system is being discussed, which lays down the operating limit for active power compensation with reactive power compensation given the priority. The functionality of the proposed control architecture is validated through a Real-Time Digital Simulator (RTDS) and Virtex 7-based FPGA controller in a Controller Hardware-in-Loop (C-HIL) environment. DA - 2023/// PY - 2023/// DO - 10.1109/APEC43580.2023.10131288 SP - 1102-1108 SN - 1048-2334 KW - Modular Multilevel Converter (MMC) KW - Static Synchronous Compensator (STATCOM) KW - Energy Sources (ES) KW - Controller hardware-in-loop (C-HIL) and Real-time digital simulator (RTDS) ER - TY - JOUR TI - Carbon-Assisted, Continuous Syngas Production in a Chemical Looping Scheme AU - Tian, Yuan AU - Benedict, Zoe AU - Li, Fanxing AU - Yang, Yingchao AU - Maiti, Debtanu AU - Wang, Yixiao AU - Fushimi, Rebecca T2 - TOPICS IN CATALYSIS AB - In the current energy and environment scenario, it is imperative to develop energy efficient routes for chemical manufacturing that also pave the way for mitigation of greenhouse gas emissions. This work presents an efficient pathway for continuous syngas production via a chemical looping conversion of the two most potent greenhouse gases—CH4, and CO2. The well-known dry-reforming process of converting CH4, and CO2 to syngas is energy-intensive and suffers from catalyst deactivation. The chemical looping approach, on the other hand, provides avenues for mitigating catalyst deactivation and enabling improved energy efficiency. The key to such process enhancements lies in the intricate structure–function relationships of the catalyst and its correlation to the process variables. We present the reduction and oxidation characteristics of 5 wt.% Ni/Ce1−xZrxO2-based catalysts (x = 0, 0.4, and 0.625). We demonstrate low temperature CH4 activation over Ni-promoted samples as opposed to pure Ce1−xZrxO2. Moreover, our results depict an optimum regeneration of these catalysts when oxidized by CO2, and H2O, which allows for chemical looping operation of steam reforming of methane as well. Process variables were tuned to optimize the CH4 conversion (over 80%), and H2/CO ratio at 650 °C. The critical surface reactions—carbon accumulation and gasification, and thermocatalytic CO2 splitting were investigated to elucidate the dynamic nature of the catalyst surface. The impact of this work lies in showcasing the opportunities to design chemical looping reactors for energy efficient syngas production from waste greenhouse gases. DA - 2023/8/16/ PY - 2023/8/16/ DO - 10.1007/s11244-023-01840-5 VL - 8 SP - SN - 1572-9028 KW - Chemical looping KW - Syngas KW - Nickel KW - ceria-zirconia KW - Decarbonization KW - CO2 and CH4 conversion ER - TY - JOUR TI - Catalytic activity and reaction mechanisms of single-atom metals anchored on nitrogen-doped carbons for peroxymonosulfate activation AU - Wu, Shaohua AU - Yang, Zhongwen AU - Zhou, Ziyang AU - Li, Xiang AU - Lin, Yan AU - Cheng, Jay J. AU - Yang, Chunping T2 - JOURNAL OF HAZARDOUS MATERIALS AB - Single-atom catalysts have attracted tremendous interests in peroxymonosulfate (PMS)-based advanced oxidation processes due to their maximum atom utilization and high reactivity, however the role of nitrogen-coordinated metal (MNx) sites with different metal centers remain blurred. Herein, a series of single-atom metals anchored on nitrogen-doped carbons (denoted as M-N/C, M = Fe, Co, Cu, and Mn) using zeolitic imidazolate frameworks as precursors are constructed for PMS activation. Their catalytic activity order follows Fe > Co > undoped N/C > Cu > Mn, especially the degradation rates of the eight model pollutants for Fe-N/C and Co-N/C are 2.5-22.4 and 1.5-19.5 times higher than those for undoped N/C, respectively. Moreover, the nature of catalytic metal center can govern the degradation behaviors in the coexisting water constituents. Experimental and theoretical results reveal that singlet oxygen (1O2) is the main oxidant responsible for pollutant degradation and its evolution path over FeN4 or CoN4 sites (PMS→OH*→*O→1O2) is elucidated, between which FeN4 with lower energy barrier is more conducive to 1O2 generation. This study can not only provide guidance for the development of highly active atomic M-N/C catalysts, but also lead to a better molecular-level understanding of PMS activation mechanism over MN4 sites. DA - 2023/10/5/ PY - 2023/10/5/ DO - 10.1016/j.jhazmat.2023.132133 VL - 459 SP - SN - 1873-3336 KW - Single-atom catalyst KW - Peroxymonosulfate KW - Advanced oxidation process KW - Zeolitic imidazolate framework KW - Singlet oxygen ER - TY - JOUR TI - Hydrogenation of bio-oil-derived oxygenates at ambient conditions via a two-step redox cycle AU - Ruan, Chongyan AU - Akutsu, Ryota AU - Yang, Kunran AU - Zayan, Noha M. AU - Dou, Jian AU - Liu, Junchen AU - Bose, Arnab AU - Brody, Leo AU - Lamb, H. Henry AU - Li, Fanxing T2 - CELL REPORTS PHYSICAL SCIENCE AB - A key challenge in upgrading bio-oils to renewable fuels and chemicals resides in developing effective and versatile hydrogenation systems. Herein, a two-step solar thermochemical hydrogenation process that sources hydrogen directly from water and concentrated solar radiation for furfural upgrading is reported. High catalytic performance is achieved at room temperature and atmospheric pressure, with up to two-orders-of-magnitude-higher hydrogen utilization efficiency compared with state-of-the-art catalytic hydrogenation. A metal or reduced metal oxide provides the active sites for furfural adsorption and water dissociation. The in situ-generated reactive hydrogen atoms hydrogenate furfural and biomass-derived oxygenates, eliminating the barriers to hydrogen dissolution and the subsequent dissociation at the catalyst surface. Hydrogenation selectivity can be conveniently mediated by solvents with different polarity and metal/reduced metal oxide catalysts with varying oxophilicity. This work provides an efficient and versatile strategy for bio-oil upgrading and a promising pathway for renewable energy storage. DA - 2023/7/19/ PY - 2023/7/19/ DO - 10.1016/j.xcrp.2023.101506 VL - 4 IS - 7 SP - SN - 2666-3864 UR - https://doi.org/10.1016/j.xcrp.2023.101506 ER - TY - JOUR TI - Action needed to make carbon offsets from forest conservation work for climate change mitigation AU - West, Thales A. P. AU - Wunder, Sven AU - Sills, Erin O. AU - Boerner, Jan AU - Rifai, Sami W. AU - Neidermeier, Alexandra N. AU - Frey, Gabriel P. AU - Kontoleon, Andreas T2 - SCIENCE AB - Carbon offsets from voluntary avoided-deforestation projects are generated on the basis of performance in relation to ex ante deforestation baselines. We examined the effects of 26 such project sites in six countries on three continents using synthetic control methods for causal inference. We found that most projects have not significantly reduced deforestation. For projects that did, reductions were substantially lower than claimed. This reflects differences between the project ex ante baselines and ex post counterfactuals according to observed deforestation in control areas. Methodologies used to construct deforestation baselines for carbon offset interventions need urgent revisions to correctly attribute reduced deforestation to the projects, thus maintaining both incentives for forest conservation and the integrity of global carbon accounting. DA - 2023/8/25/ PY - 2023/8/25/ DO - 10.1126/science.ade3535 VL - 381 IS - 6660 SP - 873-+ SN - 1095-9203 UR - https://doi.org/10.1126/science.ade3535 ER - TY - JOUR TI - Performance Evaluation of 3.3 kV SiC MOSFET and Schottky Diode Based Reverse Voltage Blocking Switch for Medium Voltage Current Source Inverter Application AU - Narasimhan, Sneha AU - Kanale, Ajit AU - Bhattacharya, Subhashish AU - Baliga, Jayant B. T2 - IEEE ACCESS AB - SiC power devices are used for medium-voltage (MV) motor drive and traction applications due to their higher temperature operation, switching frequencies, and higher efficiencies than Si-based devices. This article investigates three 3.3 kV reverse blocking or current switch configurations for their suitability in MV current-source inverter (CSI) applications. The three configurations are (1) Type I - SiC MOSFET and series Schottky diode, (2) Type II - SiC MOSFETs connected in common-source (CS), and (3) Type - III SiC MOSFETs connected in common-drain (CD) configuration. The switch configurations are characterized by comparing their on-state and switching performance at different junction temperatures varying from 25°C to 125°C. The results are used to evaluate three-phase CSI losses with three different switch configurations and choose the preferred switch configuration for MV-based CSI applications based on inverter efficiency while considering a wide range of operating points. The permissible limits of a 3.3 kV Type I switch-based CSI are presented, thus providing a safe operating area (SOA) of the switch configuration for a CSI application. Finally, the CSI is built using Type I switch configuration and is experimentally validated with an R-L load. DA - 2023/// PY - 2023/// DO - 10.1109/ACCESS.2023.3302916 VL - 11 SP - 89277-89289 SN - 2169-3536 UR - https://doi.org/10.1109/ACCESS.2023.3302916 KW - 3.3 kV SiC diode KW - 3.3 kV SiC MOSFET KW - common-source (CS) KW - common-drain (CD) KW - current source inverter (CSI) KW - current switch KW - medium-voltage (MV) KW - reverse-voltage blocking (RVB) switch KW - wide-bandgap devices KW - GaN KW - SiC ER - TY - JOUR TI - US West Coast droughts and heat waves exacerbate pollution inequality and can evade emission control policies AU - Zeighami, Amir AU - Kern, Jordan AU - Yates, Andrew J. AU - Weber, Paige AU - Bruno, August A. T2 - NATURE COMMUNICATIONS AB - Droughts reduce hydropower production and heatwaves increase electricity demand, forcing power system operators to rely more on fossil fuel power plants. However, less is known about how droughts and heat waves impact the county level distribution of health damages from power plant emissions. Using California as a case study, we simulate emissions from power plants under a 500-year synthetic weather ensemble. We find that human health damages are highest in hot, dry years. Counties with a majority of people of color and counties with high pollution burden (which are somewhat overlapping) are disproportionately impacted by increased emissions from power plants during droughts and heat waves. Taxing power plant operations based on each plant's contribution to health damages significantly reduces average exposure. However, emissions taxes do not reduce air pollution damages on the worst polluting days, because supply scarcity (caused by severe heat waves) forces system operators to use every power plant available to avoid causing a blackout. DA - 2023/3/23/ PY - 2023/3/23/ DO - 10.1038/s41467-023-37080-0 VL - 14 IS - 1 SP - SN - 2041-1723 ER - TY - JOUR TI - Quantum computing for power systems: Tutorial, review, challenges, and prospects AU - Liu, Hualong AU - Tang, Wenyuan T2 - ELECTRIC POWER SYSTEMS RESEARCH AB - As a large number of renewable energy resources are connected to power systems, the operation, planning, and optimization of power systems have been becoming more and more complex. Power flow calculation, unit commitment, economic dispatch, energy pricing, and power system planning are essentially computation problems. A lot of computing resources are required for these problems, which are non-trivial, especially for large-scale power systems with the high penetration of renewable energy. Traditionally, the calculation and optimization of power systems are completed by classical computers based on the classical computing theory and the von Neumann architecture. However, with Moore’s law getting closer and closer to the limit, the importance of quantum computing has become increasingly prominent. Quantum computing has been applied to some fields to a certain extent, yet the applications of quantum computing in power systems are rare. As the power industry is the foundation of the national economy, introducing quantum computing into the power system has far-reaching and crucial significance, such as improving the penetration of renewable energy, enhancing the computing efficiency, and helping in achieving the goal of net zero and climate neutrality by 2050. This paper first introduces the core concepts, essential ideas and theories of quantum computing, and then reviews the existing literature on the applications of quantum computing in power systems, and puts forward our critical thinking about the applications of quantum computing in power systems. In brief, this paper is dedicated to a tutorial on quantum computing targeting power system professionals and a review of its applications in power systems. The main contributions of this paper are: (1) introduce quantum computing into the field of power engineering in a thoroughly detailed way and delineate the analysis methodologies of quantum circuits systematically without losing mathematical rigor; (2) based on Dirac’s notation, the related formulae are derived meticulously with sophisticated schematic diagrams; (3) elaborate and derive some critical quantum algorithms in depth, which play an important role in the applications of quantum computing in power systems; (4) critically summarize and comment on the existing literature on the applications of quantum computing in power systems; (5) the future applications and challenges of quantum computing in power systems are prospected and remarked. DA - 2023/10// PY - 2023/10// DO - 10.1016/j.epsr.2023.109530 VL - 223 SP - SN - 1873-2046 KW - Quantum computing KW - Optimization KW - Power systems KW - Renewable energy KW - Climate neutrality ER - TY - JOUR TI - Conservation motivations and willingness to pay for wildlife management areas among recreational user groups AU - Casola, William R. AU - Peterson, M. Nils AU - Pacifici, Krishna AU - Sills, Erin O. AU - Moorman, Christopher E. T2 - LAND USE POLICY AB - Conservation agencies routinely evaluate the costs and benefits of land management and land acquisition options for wildlife management areas (WMAs). Non-market values, for example visitors’ consumer surplus, are often absent from these comparisons. Better estimates of willingness to pay (WTP) for WMAs will allow managers to quantify consumer surpluses for different user groups, identify opportunities to generate additional conservation funding, and improve communication with users. We used the contingent valuation method to estimate the WTP for conservation of WMAs by different user groups. We used interval censored regression to estimate WTP for each user group and modeled how WTP varied with visitation frequency, demographics, and type of use. Dual users, those who participated in both licensed (hunting, angling, or trapping) and non-licensed (all other) activities, had greater WTP ($200.07, 95% CI [$161.18, $238.95]) than users who exclusively participated in either a single non-licensed ($74.74, 95% CI [$50.45, $99.02]) or a single licensed activity ($68.21, 95% CI [$48.41, $88.00]). Willingness-to-pay increased with the number of visits to WMAs per year, college education, and income. The most popular donation motivations were that respondents cared about WMA conservation (72%), wanted WMAs to be around for future generations (70%) and personally benefited from the conservation of WMAs (64%). Similar to a scope test, this study demonstrated greater WTP by users who participate in more diverse recreation types on WMAs. Additionally, our findings show that WMA users, particularly users who engage in multiple activities including at least one that does not require a license, enjoy large consumer surpluses and thus could be drawn on for additional financial support for WMA conservation. DA - 2023/9// PY - 2023/9// DO - 10.1016/j.landusepol.2023.106801 VL - 132 SP - SN - 1873-5754 KW - Wildlife management areas KW - Willingness to pay KW - Contingent valuation KW - Recreation KW - Hunting ER - TY - JOUR TI - Stress of cupric ion and oxytetracycline in Chlorella vulgaris cultured in swine wastewater AU - Luo, Yun AU - Li, Xiang AU - Lin, Yan AU - Wu, Shaohua AU - Cheng, Jay J. AU - Yang, Chunping T2 - SCIENCE OF THE TOTAL ENVIRONMENT AB - Chlorella culturing has the advantages in treatment of wastewater including swine wastewater from anaerobic digesters due to the product of biolipids and the uptake of carbon dioxide. However, there often exist high concentrations of antibiotics and heavy metals in swine wastewater which could be toxic to chlorella and harmful to the biological systems. This study examined the stress of cupric ion and oxytetracycline (OTC) at various concentrations on the nutrient removal and biomass growth in Chlorella vulgaris culturing in swine wastewater from anaerobic digesters, and its biochemical responses were also studied. Results showed that dynamic hormesis of either OTC concentration or cupric ion one on Chlorella vulgaris were confirmed separately, and the presence of OTC not only did not limit biomass growth and lipids content of Chlorella vulgaris but also could mitigate the toxicity of cupric ion on Chlorella vulgaris in combined stress of Cu2+ and OTC. Extracellular polymeric substances (EPS) of Chlorella vulgaris were used to explain the mechanisms of stress for the first time. The content of proteins and carbohydrates in EPS increased, and the fluorescence spectrum intensity of tightly-bound EPS (TB-EPS) of Chlorella vulgaris decreased with increasing concentration of stress because Cu2+ and OTC may be chelated with proteins of TB-EPS to form non-fluorescent characteristic chelates. The low concentration of Cu2+ (≤1.0 mg/L) could enhance the protein content and promote the activity of superoxide dismutase (SOD) while these parameters were decreased drastically under 2.0 mg/L of Cu2+. The activity of adenosine triphosphatase (ATPase) and glutathione (GSH) enhanced with the increase of OTC concentration under combined stress. This study helps to comprehend the impact mechanisms of stress on Chlorella vulgaris and provides a novel strategy to improve the stability of microalgae systems for wastewater treatment. DA - 2023/10/15/ PY - 2023/10/15/ DO - 10.1016/j.scitotenv.2023.165120 VL - 895 SP - SN - 1879-1026 KW - Antibiotic KW - Heavy metal KW - Wastewater treatment KW - Microalgae KW - Biodiesel KW - EPS ER - TY - CONF TI - Finite Element Analysis and Fatigue Life Prediction of A Laterally Conducting Gan-Based Power Package Under Thermal CyclingASME 2023 Int’l Mechanical Eng. Congress and Exposition C2 - 2023/10/29/ C3 - ASME 2023 Int’l Mechanical Eng. Congress and Exposition DA - 2023/10/29/ UR - https://event.asme.org/IMECE ER - TY - JOUR TI - Perspective: Phosphorus monitoring must be rooted in sustainability frameworks spanning material scale to human scale AU - McLamore, Eric AU - Duckworth, Owen AU - Boyer, Treavor H. AU - Marshall, Anna-Maria AU - Call, Douglas F. AU - Bhadha, Jehangir H. AU - Guzman, Sandra T2 - WATER RESEARCH X AB - Phosphorus (P) is a finite resource, and its environmental fate and transport is complex. With fertilizer prices expected to remain high for years and disruption to supply chains, there is a pressing need to recover and reuse P (primarily as fertilizer). Whether recovery is to occur from urban systems (e.g., human urine), agricultural soil (e.g., legacy P), or from contaminated surface waters, quantification of P in various forms is vital. Monitoring systems with embedded near real time decision support, so called cyber physical systems, are likely to play a major role in the management of P throughout agro-ecosystems. Data on P flow(s) connects the environmental, economic, and social pillars of the triple bottom line (TBL) sustainabilty framework. Emerging monitoring systems must account for complex interactions in the sample, and interface with a dynamic decision support system that considers adaptive dynamics to societal needs. It is known from decades of study that P is ubiquitous, yet without quantitative tools for studying the dynamic nature of P in the environment, the details may remain elusive. If new monitoring systems (including CPS and mobile sensors) are informed by sustainability frameworks, data-informed decision making may foster resource recovery and environmental stewardship from technology users to policymakers. DA - 2023/5/1/ PY - 2023/5/1/ DO - 10.1016/j.wroa.2023.100168 VL - 19 SP - SN - 2589-9147 KW - Phosphate KW - Cyber-physical systems KW - Sensor KW - Decision support ER - TY - JOUR TI - Hydrous Transition Metal Oxides for Electrochemical Energy and Environmental Applications AU - Mitchell, James B. AU - Chagnot, Matthew AU - Augustyn, Veronica T2 - ANNUAL REVIEW OF MATERIALS RESEARCH DA - 2023/// PY - 2023/// DO - 10.1146/annurev-matsci-080819-1249550 VL - 53 SP - 1-23 SN - 1545-4118 KW - transition metal oxides KW - energy storage KW - energy conversion KW - insertion KW - electrochemistry KW - structural water ER - TY - JOUR TI - One-Step Synthesis of a High Entropy Oxide-Supported Rhodium Catalyst for Highly Selective CO Production in CO2 Hydrogenation AU - Zhu, Siyuan AU - Chen, Yufeng AU - Somayaji, Vasishta AU - Novello, Peter AU - Chacko, Dennis AU - Li, Fanxing AU - Liu, Jie T2 - ACS APPLIED MATERIALS & INTERFACES AB - High entropy oxide (HEO) has shown to be a new type of catalyst support with tunable composition–function properties for many chemical reactions. However, the preparation of a metal nanoparticle catalyst supported on a metal oxide support is time-consuming and takes multiple complicated steps. Herein, we used a one-step glycine–nitrate-based combustion method to synthesize highly dispersed rhodium nanoparticles on a high surface area HEO. This catalyst showed high selectivity to produce CO in CO2 hydrogenation with 80% higher activity compared to rhodium nanoparticle-based catalysts. We also studied the effect of different metal elements in HEO and demonstrated that high CO selectivity was achieved if one of the metals in the metal oxide support favored CO production. We identified that copper and zinc were responsible for the observed high CO selectivity due to their low *CO binding strength. During hydrogenation, a strong metal-support interaction was created through charge transfer and formed an encapsulated structure between rhodium nanoparticles and the HEO support to lower the *CO binding strength, which enabled high CO selectivity in the reaction. By combining different metal oxides into HEO as a catalyst support, high activity and high selectivity can be achieved at the same time in the CO2 hydrogenation reaction. DA - 2023/6/21/ PY - 2023/6/21/ DO - 10.1021/acsami.3c02829 VL - 15 IS - 26 SP - 31384-31392 SN - 1944-8252 UR - https://doi.org/10.1021/acsami.3c02829 KW - high entropy oxide KW - CO2 hydrogenation KW - strong metal-support interaction KW - one-step synthesis KW - rhodium-based catalyst ER - TY - JOUR TI - Combined effects of oxytetracycline concentration and organic loading rate on semi-continuous anaerobic digestion of swine wastewater AU - Huang, Zhiwei AU - Niu, Qiuya AU - Nie, Wenkai AU - Lin, Yan AU - Wu, Shaohua AU - Li, Xiang AU - Cheng, Jay J. AU - Yang, Chunping T2 - BIORESOURCE TECHNOLOGY AB - High concentrations of antibiotics in swine wastewater raises concerns about the potential adverse effects of anaerobic digestion (AD). Current studies mainly focused on the effects of various antibiotic concentrations. However, these studies didn't take into account the fluctuation of swine wastewater quality and the change of reactor operating conditions in practical engineering applications. In this study, it was found that in the operating systems with COD of 3300 mg/L and hydraulic retention time (HRT) of 4.4 days, the continuous addition of oxytetracycline for 30 days had no effect on the AD performance. Nevertheless, when COD and HRT were changed to 4950 mg/L and 1.5 days respectively, oxytetracycline at 2 and 8 mg/L increased the cumulative methane yield by 27% and 38% at the cost of destroying cell membrane, respectively, while oxytetracycline at 0.3 mg/L improved the performance and stability of AD. These results could be referred for practical engineering applications. DA - 2023/8// PY - 2023/8// DO - 10.1016/j.biortech.2023.129179 VL - 382 SP - SN - 1873-2976 KW - Methane KW - Extracellular polymeric substance KW - Microbial activity KW - Antibiotic KW - Biological treatment ER - TY - JOUR TI - Scenario generation and risk-averse stochastic portfolio optimization applied to offshore renewable energy technologies AU - Faria, Victor A. D. AU - Queiroz, Anderson Rodrigo AU - DeCarolis, Joseph F. T2 - ENERGY AB - This work proposes an analytical decision-making framework considering scenario generation using artificial neural networks and risk-averse stochastic programming to define renewable offshore portfolios of wind, wave, and ocean current technologies. For the scenario generation, a generative adversarial neural network is developed to generate synthetic energy scenarios considering resources distributed over large geographic regions. These scenarios are then fed to a stochastic model, which objective to determine the optimal location and number of turbines for each technology. In the stochastic model formulation, a representation of the limits in the portfolio Levelized Cost of Energy and the maximization of the five percent lower energy generation conditions, also known as Conditional Value at Risk, is presented. The framework proposed here is tested considering data from a portion of the U.S. East coast, where the generative model was successful in creating energy scenarios statistically consistent with the historical data for wind, wave, and ocean current resources at more than 500 sites. Furthermore, the Conditional Value at Risk portfolio optimization model was used to construct efficient frontiers for a combination of different technologies, showing the significance of resource diversification as a tool to improve system security. DA - 2023/5/1/ PY - 2023/5/1/ DO - 10.1016/j.energy.2023.126946 VL - 270 SP - SN - 1873-6785 KW - Generative adversarial neural networks KW - Portfolio optimization KW - Risk assessment KW - Optimal site selection KW - Renewable energy ER - TY - JOUR TI - CaMn0.9Ti0.1O3 based redox catalysts for chemical looping-Oxidative dehydrogenation of ethane: Effects of Na2MoO4 promoter and degree of reduction on the reaction kinetics AU - Tian, Yuan AU - Westmoreland, Phillip R. AU - Li, Fanxing T2 - CATALYSIS TODAY AB - Reduction kinetics and stability of 20 wt% Na2MoO4-promoted CaMn0.9Ti0.1O3 were investigated for its applications in Chemical Looping – Oxidative Dehydrogenation (CL-ODH) of ethane, a potential alternative for ethylene production with higher efficiency and lower emissions. The present work reports a kinetics model and parameters for a Na2MoO4-promoted, Ti-doped CaMnO3 (CaMn0.9Ti0.1O3) redox catalyst under H2 and C2H4. A first-order reaction model provides the best fit for the reduction of Na2MoO4/CaMn0.9Ti0.1O3 under H2, while the C2H4 reduction is well described by an Avrami–Erofe’ev model. The activation energy for C2H4 oxidation is approximately three times higher than that for H2 conversion, showing that the activation of C2H4 is significantly more difficult on the surface of the redox catalyst. The reduction rate of Na2MoO4/CaMn0.9Ti0.1O3 under H2 at 750 °C is more than two orders of magnitude greater than that under C2H4, while the reduction rate of unpromoted CaMn0.9Ti0.1O3 is comparable under H2 and C2H4, showing that the addition of Na2MoO4 effectively suppresses C2H4 combustion relative to H2 oxidation. The kinetics results for Na2MoO4/CaMn0.9Ti0.1O3 confirm its excellent selectivity towards hydrogen combustion, making it a promising candidate under CL-ODH. Additionally, the stability of the CaMn0.9Ti0.1O3@ Na2MoO4 core-shell structure, which was the underlying reason for the excellent selectivity, was examined under both shallow and deep reductions. It was determined that deep reduction of the redox catalyst, e.g. higher than 80% solid conversion, would lead to loss of sodium and hence to decreased selectivity for hydrogen combustion. In contrast, the core-shell structure was well-maintained, exhibiting excellent performance after 50 redox cycles when deep reduction of the redox catalyst was avoided. This study offers a basis for both the CL-ODH reactor design and redox catalyst optimizations. DA - 2023/5/1/ PY - 2023/5/1/ DO - 10.1016/j.cattod.2022.04.026 VL - 417 SP - SN - 1873-4308 KW - redox catalyst KW - oxidative dehydrogenation KW - chemical looping KW - selective hydrogen combustion KW - ethylene ER - TY - JOUR TI - Comparative Analysis of ANN and LSTM Prediction Accuracy and Cooling Energy Savings through AHU-DAT Control in an Office Building AU - Seo, Byeongmo AU - Yoon, Yeobeom AU - Lee, Kwang Ho AU - Cho, Soolyeon T2 - BUILDINGS AB - This paper proposes the optimal algorithm for controlling the HVAC system in the target building. Previous studies have analyzed pre-selected algorithms without considering the unique data characteristics of the target building, such as location, climate conditions, and HVAC system type. To address this, we compare the accuracy of cooling load prediction using ANN and LSTM algorithms, widely used in building energy research, to determine the optimal algorithm for HVAC control in the target building. We develop a simulation model calibrated with actual data to ensure data reliability and compare the energy consumption of the existing HVAC control method and the two algorithms-based methods. Results show that the ANN algorithm, with a CV(RMSE) of 12.7%, has a higher prediction accuracy than the LSTM algorithm, CV(RMSE) of 17.3%, making it a more suitable algorithm for HVAC control. Furthermore, implementing the ANN-based approach results in a 3.2% cooling energy reduction from the optimal control of Air Handling Unit (AHU) Discharge Air Temperature (DAT) compared to the fixed DAT at 12.8 °C in a representative day. This study demonstrates that ML-based HVAC system control can effectively reduce cooling energy consumption in HVAC systems, providing an effective strategy for energy conservation and improved HVAC system efficiency. DA - 2023/6// PY - 2023/6// DO - 10.3390/buildings13061434 VL - 13 IS - 6 SP - SN - 2075-5309 KW - EnergyPlus KW - artificial neural network KW - long short-term memory KW - discharged air temperature KW - optimal control ER - TY - CONF TI - Design & Integration of Solid-State Circuit Protection AU - Hopkins, Douglas C. AU - Sinha, Sourish S. T2 - IEEE Applied Power Electronics Conference C2 - 2023/3/19/ C3 - IEEE Applied Power Electronics Conference CY - Orange County Convention Center, Orlando, FL DA - 2023/3/19/ PY - 2023/3/19/ ER - TY - CONF TI - Analysis and Characterization of Four-quadrant Switches based Commutation Cell AU - Narwal, Ramandeep AU - Rawat, Shubham AU - Kanale, Ajit AU - Cheng, Tzu-Hsuan AU - Agarwal, Aditi AU - Bhattacharya, Subhashish AU - Baliga, B. Jayant AU - Hopkins, Douglas C. T2 - 2023 IEEE Applied Power Electronics Conference and Exposition (APEC) AB - A four-quadrant switch (FQS) blocks either polarity voltage and controls current flow in both directions. Unlike voltage-source converters, in which two-quadrant switches operate over a narrow voltage range, four-quadrant switches are required to operate over a wide range of both voltage and current in applications such as matrix converters and current-source converters. Furthermore, matrix converters require multi-step commutation schemes compared to two-step schemes for current-bidirectional switch based voltage-source converters and voltage-bidirectional switch based current-source converters. This paper provides a generalized overview of commutation schemes used for two and four quadrant switches based two-level commutation cells, identifies comparison indices for FQS commutation schemes, and discusses the need for adaptive commutation-step times for wide voltage and current variation applications. Also, the static and dynamic characteristics of 1.2 kV rated FQS implementations utilizing commercial SiC MOSFETs from four different manufacturers and novel monolithic SiC BiDirectional Field Effect Transistor (BiDFET) have been reported. C2 - 2023/3/19/ C3 - 2023 IEEE Applied Power Electronics Conference and Exposition (APEC) DA - 2023/3/19/ DO - 10.1109/APEC43580.2023.10131312 SP - 209-216 PB - IEEE UR - http://dx.doi.org/10.1109/apec43580.2023.10131312 KW - Commutation cell KW - four quadrant switch KW - SiC Bidirectional FET KW - BiDFET KW - characterization KW - switching loss KW - dead time KW - overlap time KW - commutation scheme KW - matrix converter ER - TY - CONF TI - Advanced GaN IPM for High-Frequency Converter Applications Enabled with Thin-Substrates AU - Sinha, Sourish S. AU - Cheng, Tzu-Hsuan AU - Parmar, Keval AU - Hopkins, Douglas C. T2 - 2023 IEEE Applied Power Electronics Conference and Exposition (APEC) AB - Extracting the potential of Wide Bandgap (WBG) semiconductor devices needs enhanced electrical and thermal packaging. This paper presents a half-bridge GaN-based Integrated Power Module (IPM) with inclusive gate drivers, driver caps, and decoupling caps for a 500kHz/0.8kW converter application. Presented are the design, fabrication, and experimental characterization of a dense, double-side cooled IPM utilizing an advanced epoxy-resin insulated metal substrate (eIMS) with 120µm thin dielectric for 400V/ 8.3ns high edge-rate switching (i.e. with $dv/dt$ of highest frequency of interest (HFI)). The common mode (CM) capacitance has been optimized. The thermal performance of the module was validated through ANSYS simulation, and the symmetry of the sandwiched substrate structure ensured for symmetric temperature distribution and stress management. An experimental Double Pulse Test (DPT) board with low isolation capacitance was developed to characterize the maximum dynamic performance. Finally, the CM effects on a full-bridge converter application are evaluated to show the efficacy of thin-substrate packaging for application at industrial power levels. C2 - 2023/3/19/ C3 - 2023 IEEE Applied Power Electronics Conference and Exposition (APEC) DA - 2023/3/19/ DO - 10.1109/apec43580.2023.10131488 SP - 2596-2603 PB - IEEE UR - http://dx.doi.org/10.1109/apec43580.2023.10131488 KW - GaN power module KW - thin substrate KW - substrate current KW - Double Pulse Test KW - Full Bridge Converter ER - TY - CONF TI - Thermal Cycling and Fatigue Life Analysis of a Laterally Conducting GaN-based Power Package AU - Zaghari, Pouria AU - Sinha, Sourish S. AU - Ryu, Jong Eun AU - Franzon, Paul D. AU - Hopkins, Douglas C. T2 - 2023 IEEE International 3D Systems Integration Conference (3DIC) AB - Thermal reliability is a critical factor in ensuring the performance and efficiency of GaN-based electronic devices. In this paper, the fatigue life assessment of a laterally conducting GaN power package that uses a two-solder hierarchy of SAC305 and Sn63/Pb37 on a 120μm thick dielectric for device attach was conducted using an FEA. The double-sided package structure also introduced thick Cu as integrated baseplate layers for mechanical mounting into higher packaging levels while providing surfaces for double-sided cooling. The internal structure varied spacer thicknesses for planarization and inclusion of package-integrated decoupling capacitors. The solder materials were simulated by using the Anand viscoplastic constitutive model. Coffin-Manson, Engelmaier, and Solomon empirical strain-based models were utilized to predict the cyclic life of the package. Based on the results, the critical solder joint location was predicted in the Sn63/Pb37 solder layer between the GaN and Cu spacer, with a strain range of 0.02797. The worst-case life prediction for the module was 150 cycles using the Coffin-Manson model. C2 - 2023/5/10/ C3 - 2023 IEEE International 3D Systems Integration Conference (3DIC) DA - 2023/5/10/ DO - 10.1109/3dic57175.2023.10154901 SP - PB - IEEE UR - http://dx.doi.org/10.1109/3dic57175.2023.10154901 KW - GaN power module KW - thermal reliability KW - mechanical stress KW - fatigue life prediction KW - finite element analysis ER - TY - JOUR TI - Choice of Electrolyte Impacts the Selectivity of Proton-Coupled Electrochemical Reactions on Hydrogen Titanate AU - Fortunato, Jenelle AU - Shin, Yun Kyung AU - Spencer, Michael A. A. AU - Duin, Adri C. T. AU - Augustyn, Veronica T2 - JOURNAL OF PHYSICAL CHEMISTRY C AB - Proton-coupled electron transfer (PCET) reactions involving transition metal oxides are prevalent in aqueous electrochemical systems used for energy storage and conversion. Here, we elucidate the role of electrolyte on PCET mechanisms in transition metal oxides in aqueous acidic electrolytes using layered hydrogen titanate (H2Ti3O7) as an example. We identify three processes by which electrolyte protons interact with hydrogen titanate at the electrochemical interface: (1) adsorption at the surface and/or insertion into the bulk, (2) adsorption as part of the hydrogen evolution reaction (HER) at the surface, and (3) dissolution of the hydrogen titanate. We utilize a combined experimental and computational (ReaxFF) approach to probe how the competition for protons and electrons among these processes influences electrochemical properties, including the energy storage, Coulombic efficiency (CE), rate capability, and lifetime. In an acidic buffered electrolyte (1 M H3PO4), the CE increases from an average of 48% to 71% and the specific capacity increases from 83 to 90 mAh g–1 as compared to a strong acid electrolyte (1 M H2SO4). We propose that H3PO4 mitigates the HER and hydrogen titanate dissolution, thereby increasing the operating potential window for proton adsorption/insertion for charge storage in hydrogen titanate. Material characterization and computational results indicate that adsorption of phosphate species onto the surface of hydrogen titanate may decrease its dissolution upon reduction, thereby improving electrode performance. We offer a preliminary solution to improve energy storage performance via electrolyte tuning by decreasing the prevalence of the HER and electrode dissolution. DA - 2023/6/14/ PY - 2023/6/14/ DO - 10.1021/acs.jpcc.3c01057 SP - SN - 1932-7455 ER - TY - JOUR TI - Understanding the Food-Energy-Water Nexus in Mixed Irrigation Regimes Using a Regional Hydroeconomic Optimization Modeling Framework AU - Kumar, Hemant AU - Zhu, Tingju AU - Sankarasubramanian, A. T2 - WATER RESOURCES RESEARCH AB - Abstract Understanding the nexus between food, energy, and water systems (FEW) is critical for basins with intensive agricultural water use as they face significant challenges under changing climate and regional development. We investigate the food, energy, and water nexus through a regional hydroeconomic optimization (RHEO) modeling framework. The crop production in RHEO is estimated through a hierarchical regression model developed using a biophysical model, AquaCropOS, forced with daily climatic inputs. Incorporating the hierarchical model within the RHEO also reduces the computation time by enabling parallel programming within the AquaCropOS and facilitates mixed irrigation—rainfed, fully irrigated and deficit irrigation—strategies. To demonstrate the RHEO framework, we considered a groundwater‐dominated basin, South Flint River Basin, Georgia, for developing mixed irrigation strategies over 31 years. Our analyses show that optimal deficit irrigation is economically better than full irrigation, which increases the groundwater pumping cost. Thus, considering deficit irrigation in a groundwater‐dominated basin reduces the water, carbon, and energy footprints, thereby reducing FEW vulnerability. The RHEO also could be employed for analyzing FEW nexus under potential climate change and future regional development scenarios. DA - 2023/6// PY - 2023/6// DO - 10.1029/2022WR033691 VL - 59 IS - 6 SP - SN - 1944-7973 UR - https://doi.org/10.1029/2022WR033691 KW - food-energy-water nexus KW - hydroeconomic model KW - positive mathematical programming ER - TY - JOUR TI - Mechanistic understanding of microstructure formation during synthesis of metal oxide/carbon nanocomposites AU - Elmanzalawy, Mennatalla AU - Innocenti, Alessandro AU - Zarrabeitia, Maider AU - Peter, Nicolas J. AU - Passerini, Stefano AU - Augustyn, Veronica AU - Fleischmann, Simon T2 - JOURNAL OF MATERIALS CHEMISTRY A AB - In situ analysis of physicochemical processes occurring during pyrolysis synthesis of a TMO/C nanocomposite, including microstructure analysis via (S)TEM. Characterization of materials as electrodes for lithium intercalation and conversion reactions. DA - 2023/6/13/ PY - 2023/6/13/ DO - 10.1039/d3ta01230a SP - SN - 2050-7496 ER - TY - JOUR TI - Effect of Electrode/Electrolyte Coupling on Birnessite (delta-MnO2) Mechanical Response and Degradation AU - Tsai, Wan-Yu AU - Pillai, Shelby B. B. AU - Ganeshan, Karthik AU - Saeed, Saeed AU - Gao, Yawei AU - Duin, Adri C. T. AU - Augustyn, Veronica AU - Balke, Nina T2 - ACS APPLIED MATERIALS & INTERFACES AB - Understanding the deformation of energy storage electrodes at a local scale and its correlation to electrochemical performance is crucial for designing effective electrode architectures. In this work, the effect of electrolyte cation and electrode morphology on birnessite (δ-MnO2) deformation during charge storage in aqueous electrolytes was investigated using a mechanical cyclic voltammetry approach via operando atomic force microscopy (AFM) and molecular dynamics (MD) simulation. In both K2SO4 and Li2SO4 electrolytes, the δ-MnO2 host electrode underwent expansion during cation intercalation, but with different potential dependencies. When intercalating Li+, the δ-MnO2 electrode presents a nonlinear correlation between electrode deformation and electrode height, which is morphologically dependent. These results suggest that the stronger cation-birnessite interaction is the reason for higher local stress heterogeneity when cycling in Li2SO4 electrolyte, which might be the origin of the pronounced electrode degradation in this electrolyte. DA - 2023/5/18/ PY - 2023/5/18/ DO - 10.1021/acsami.3c02055 VL - 15 IS - 21 SP - 26120-26127 SN - 1944-8252 KW - Operando AFM KW - Mechanical cyclic voltammetry KW - Electrode microstructure KW - Electro-chemo-mechanical coupling KW - Pseudocapacitors ER - TY - JOUR TI - Droop-Based Distributed Secondary Control Method With Reduced Communication Complexity for Radial DC Microgrids AU - Sharma, Shrivatsal AU - Iyer, Vishnu Mahadeva AU - Bhattacharya, Subhashish AU - Zou, Ke AU - Kikuchi, Jun T2 - IEEE Journal of Emerging and Selected Topics in Industrial Electronics AB - This article proposes a distributed secondary control method for radial dc microgrid systems with reduced communication complexity. The proposed method utilizes the bus voltage information of the dc microgrid, which is communicated to the individual converters. The proposed method is distributed in nature as the secondary controllers are implemented locally at each converter. The proposed method does not require communication channels between individual converters. Thus, it achieves accurate current sharing and good load voltage regulation with reduced complexity compared to state-of-the-art control methods. The proposed method is robust, and its performance gracefully degrades in the event of a failure of a communication channel. Also, the addition or removal of a converter is seamless with the proposed method. The effectiveness of the proposed method is validated using circuit simulations and hardware-based experiments on different configurations of radial dc microgrid systems. DA - 2023/7// PY - 2023/7// DO - 10.1109/JESTIE.2023.3246932 UR - https://doi.org/10.1109/JESTIE.2023.3246932 ER - TY - JOUR TI - Sorption-enhanced steam reforming of toluene using multifunctional perovskite phase transition sorbents in a chemical looping scheme AU - Brody, Leo AU - Rukh, Mahe AU - Cai, Runxia AU - Bosari, Azin Saberi AU - Schomaecker, Reinhard AU - Li, Fanxing T2 - JOURNAL OF PHYSICS-ENERGY AB - Abstract Sorption-enhanced steam reforming (SESR) of toluene (SESRT) using catalytic CO 2 sorbents is a promising route to convert the aromatic tar byproducts formed in lignocellulosic biomass gasification into hydrogen (H 2 ) or H 2 -rich syngas. Commonly used sorbents such as CaO are effective in capturing CO 2 initially but are prone to lose their sorption capacity over repeated cycles due to sintering at high temperatures. Herein, we present a demonstration of SESRT using A- and B-site doped Sr 1− x A’ x Fe 1− y B’ y O 3− δ (A’ = Ba, Ca; B’ = Co) perovskites in a chemical looping scheme. We found that surface impregnation of 5–10 mol% Ni on the perovskite was effective in improving toluene conversion. However, upon cycling, the impregnated Ni tends to migrate into the bulk and lose activity. This prompted the adoption of a dual bed configuration using a pre-bed of NiO/ γ –Al 2 O 3 catalyst upstream of the sorbent. A comparison is made between isothermal operation and a more traditional temperature-swing mode, where for the latter, an average sorption capacity of ∼38% was witnessed over five SESR cycles with H 2 -rich product syngas evidenced by a ratio of H 2 : CO x > 4.0. XRD analysis of fresh and cycled samples of Sr 0.25 Ba 0.75 Fe 0.375 Co 0.625 O 3- δ reveal that this material is an effective phase transition sorbent—capable of cyclically capturing and releasing CO 2 without irreversible phase changes occurring. DA - 2023/7/1/ PY - 2023/7/1/ DO - 10.1088/2515-7655/acdbe9 VL - 5 IS - 3 SP - SN - 2515-7655 UR - https://doi.org/10.1088/2515-7655/acdbe9 KW - syngas KW - perovskite oxide KW - sorption-enhanced steam reforming KW - chemical looping KW - phase transition sorbents ER - TY - JOUR TI - Numerical modeling of chemical looping oxidative dehydrogenation of ethane in parallel packed beds AU - Cai, Runxia AU - Brody, Leo AU - Tian, Yuan AU - Neal, Luke AU - Bose, Arnab AU - Li, Fanxing T2 - CHEMICAL ENGINEERING JOURNAL AB - Chemical looping oxidative dehydrogenation (CL-ODH) of ethane has the potential to be a highly efficient alternative to steam cracking for ethylene production. Accurate reactor modeling is of critical importance to efficiently scale up and optimize this new technology. This study reports a one-dimensional, heterogeneous packed bed model to simulate the CL-ODH of ethane to ethylene with a Na2MoO4-promoted CaTi0.1Mn0.9O3 redox catalyst. The overall reaction kinetics was well-described by coupling the gas-phase steam cracking of ethane with the reduction kinetics of the redox catalyst by H2 and C2H4. The impact of H2 on the formation rate of CO2 byproduct from C2H4 conversion was also thoroughly investigated to validate the applicability of the kinetic model under operational environments. The temperature variation within the different CL-ODH steps and the temperature distribution along the bed were also carefully considered. The accuracy of the model was validated by experiments conducted in a large lab-scale packed bed reactor (200 g catalyst loading), with an average deviation of 2.8% in terms of ethane conversion and ethylene yield. The model was subsequently used to optimize the operating parameters of the CL-ODH reactor, indicating that up to 63.7% single-pass C2 + olefin yield can be achieved with the current redox catalyst bed whereas further optimization of the redox catalyst to inhibit C2H4 activation can result in 69.4% single-pass C2 + yield while maintaining low CO2 selectivity. DA - 2023/8/1/ PY - 2023/8/1/ DO - 10.1016/j.cej.2023.143930 VL - 469 SP - SN - 1873-3212 UR - https://doi.org/10.1016/j.cej.2023.143930 KW - Chemical looping KW - Oxidative dehydrogenation KW - Modeling KW - Redox catalyst KW - Ethylene ER - TY - JOUR TI - The promise of coupling geologic CO2 storage with sedimentary basin geothermal power generation AU - Bielicki, Jeffrey M. AU - Leveni, Martina AU - Johnson, Jeremiah X. AU - Ellis, Brian R. T2 - ISCIENCE AB - Achieving ambitious greenhouse gas mitigation targets will require technological advances and cost reductions in dispatchable carbon-free power generation sources that can provide load following flexibility to integrate high penetrations of variable wind and solar power. Several other sectors may be difficult to decarbonize and a net-zero or net-negative carbon economy may require the deployment of geologic carbon dioxide (CO2) storage. Utilizing CO2 as a working fluid for geothermal energy production and energy storage can achieve both goals: isolating CO2 from the atmosphere and providing valuable power system services to enable high penetrations of variable carbon-free electricity production. The use of CO2 as a working fluid facilitates access to low-grade heat in sedimentary basins, which are widely available and could allow for strategic citing near CO2 sources or where power system flexibility is needed. In this perspective piece, we summarize the state of knowledge for sedimentary basin CO2-geothermal, sometimes referred to as CO2 plume geothermal, and explore how it could support decarbonization of the energy sector. We also present the potential for using geologically stored CO2 for bulk energy storage which could provide valuable time-shifting and other services to the power grid. We explore the promise and challenges of these technologies, identify key research gaps, and offer a critical appraisal of the role that policy for a technology at the intersection of renewable energy, energy storage, and geologic CO2 storage may play in achieving broad deployment. DA - 2023/2/17/ PY - 2023/2/17/ DO - 10.1016/j.isci.2022.105618 VL - 26 IS - 2 SP - SN - 2589-0042 ER - TY - JOUR TI - Potential Cooling Energy Savings of Economizer Control and Artificial-Neural-Network-Based Air-Handling Unit Discharge Air Temperature Control for Commercial Building AU - Yoon, Yeobeom AU - Seo, Byeongmo AU - Cho, Soolyeon T2 - BUILDINGS AB - Heating, ventilation, and air-conditioning (HVAC) systems play a significant role in building energy consumption, accounting for around 50% of total energy usage. As a result, it is essential to explore ways to conserve energy and improve HVAC system efficiency. One such solution is the use of economizer controls, which can reduce cooling energy consumption by using the free-cooling effect. However, there are various types of economizer controls available, and their effectiveness may vary depending on the specific climate conditions. To investigate the cooling energy-saving potential of economizer controls, this study employs a dry-bulb temperature-based economizer control approach. The dry-bulb temperature-based control strategy uses the outdoor air temperature as an indicator of whether free cooling can be used instead of mechanical cooling. This study also introduces an artificial neural network (ANN) prediction model to optimize the control of the HVAC system, which can lead to additional cooling energy savings. To develop the ANN prediction model, the EnergyPlus program is used for simulation modeling, and the Python programming language is employed for model development. The results show that implementing a temperature-based economizer control strategy can lead to a reduction of 7.6% in annual cooling energy consumption. Moreover, by employing an ANN-based optimal control of discharge air temperature in air-handling units, an additional 22.1% of cooling energy savings can be achieved. In conclusion, the findings of this study demonstrate that the implementation of economizer controls, especially the dry-bulb temperature-based approach, can be an effective strategy for reducing cooling energy consumption in HVAC systems. Additionally, using ANN prediction models to optimize HVAC system controls can further increase energy savings, resulting in improved energy efficiency and reduced operating costs. DA - 2023/4/28/ PY - 2023/4/28/ DO - 10.3390/buildings13051174 VL - 13 IS - 5 SP - SN - 2075-5309 KW - EnergyPlus KW - artificial neural network KW - economizer KW - discharged air temperature KW - optimal control ER - TY - JOUR TI - LaNixFe1_xO3 as flexible oxygen or carbon carriers for tunable syngas production and CO2 utilization AU - Iftikhar, Sherafghan AU - Martin, William AU - Gao, Yunfei AU - Yu, Xinbin AU - Wang, Iwei AU - Wu, Zili AU - Li, Fanxing T2 - CATALYSIS TODAY AB - The current study reports LaFe1−xNixO3−δ redox catalysts as flexible oxygen or carbon carriers for CO2 utilization and tunable production of syngas at relatively low temperatures (∼700 °C), in the context of a hybrid redox process. Specifically, perovskite-structured LaFe1−xNixO3−δ with seven different compositions (x = 0.4–1) were prepared and investigated. Cyclic experiments under alternating methane and CO2 flows indicated that all the samples exhibited favorable reactive performance: CH4 and CO2 conversions varied between 85% and 98% and 70–88%, respectively. While H2/CO ratio from Fe-rich redox catalysts was ~2.3:1 in the methane conversion step, Ni-rich catalysts produced a concentrated (~ 93.7 vol%) hydrogen stream via methane cracking. The flexibility of LaFe1−xNixO3−δ to produce syngas (or hydrogen) with tunable compositions was found to be governed by the iron/nickel (Fe/Ni) ratio. Redox catalysts with higher Fe contents act as a lattice oxygen carrier via chemical looping partial oxidation (CLPOx) of methane whereas those with higher Ni contents function as a carbon carrier via chemical looping methane cracking (CLMC) scheme. XRD analysis and temperature-programmed reactions revealed that both types of catalysts involve the formation of La2O3 and Ni0 /Ni-Fe phases under the methane environment. The ability to re-incorporate La2O3 and Ni/Fe into a perovskite structure gives rise to oxygen-carrying capacity whereas stable Ni0 or Ni/Fe phases would catalyze methane cracking without lattice oxygen exchange in the reaction cycles. Temperature programmed oxidation and Raman spectroscopy indicated the presence of graphitic and amorphous carbon species, which were effectively gasified by CO2 to produce concentrated CO. Stability tests over LaFe0.5Ni0.5O3 and LaNiO3 revealed that the redox performance was stable over a span of 50 cycles. DA - 2023/4/1/ PY - 2023/4/1/ DO - 10.1016/j.cattod.2022.07.022 VL - 416 SP - SN - 1873-4308 KW - CO2 utilization KW - Syngas KW - Methane KW - Chemical looping KW - Redox catalyst KW - Hydrogen ER - TY - PCOMM TI - Credit credibility threatens forests AU - Balmford, Andrew AU - Brancalion, Pedro H. S. AU - Coomes, David AU - Filewod, Ben AU - Groom, Ben AU - Guizar-Coutino, Alejandro AU - Jones, Julia P. G. AU - Keshav, Srinivasan AU - Kontoleon, Andreas AU - Madhavapeddy, Anil AU - Malhi, Yadvinder AU - Sills, Erin O. AU - Strassburg, Bernardo B. N. AU - Venmans, Frank AU - West, Thales A. P. AU - Wheeler, Charlotte AU - Swinfield, Tom DA - 2023/5/5/ PY - 2023/5/5/ DO - 10.1126/science.adh3426 SP - 466-467 ER - TY - JOUR TI - Robust Controller for Community Microgrids for Stability Improvement in Islanded Mode AU - Chen, Ke AU - Baran, Mesut T2 - IEEE TRANSACTIONS ON POWER SYSTEMS AB - Many utilities are developing microgrids to improve power reliability and grid resiliency for customers. One critical challenge in microgrid design is maintaining system stability with changing operating conditions in the microgrid. The technical and contractual constraints of accessibility and controllability to customer-owned resources limit available control options. This paper details a single-phase community microgrid model and illustrates the stability challenges. It further proposes adopting an optimal controller using predictive current control (PCC) and robust control mu-synthesis to improve microgrid stability in islanded operating mode. Incorporating the mu-synthesis in the controller design assures the microgrid's robust stability. The proposed method facilitates the incorporation of main uncertainties in the microgrid: change in resources, uncertainties in their modeling, and load variation. The proposed method overcomes the constraints and does not impact the customer's resources normal operation. Furthermore, the controller has a simple structure and is easy to implement. The simulation results validate that the designed controller can maintain the system stability and achieve optimal performance against various changes in the microgrid. This paper presents a practical solution to the challenges utilities are facing in microgrid development. DA - 2023/5// PY - 2023/5// DO - 10.1109/TPWRS.2022.3192459 VL - 38 IS - 3 SP - 2472-2484 SN - 1558-0679 KW - Microgrids KW - Power system stability KW - Load modeling KW - Impedance KW - Uncertainty KW - Inverters KW - Voltage control KW - Control design KW - distributed energy resources KW - microgrids KW - parameter uncertainty KW - robust control KW - robust stability KW - small-signal modeling ER - TY - JOUR TI - Health-Aware Energy Management Strategy Toward Internet of Storage AU - Yin, Chen AU - Wang, Jianxiao AU - Tang, Wenyuan AU - Li, Gengyin AU - Zhou, Ming T2 - IEEE INTERNET OF THINGS JOURNAL AB - The rapid development of the Internet of Things (IoT) has given rise to a novel business model, i.e., Internet of Storage (IoS), in which distributed in-home storage systems can be shared and equivalently aggregated as a utility-scale storage. While the existing literature has focused on the scheduling of distributed storage, few studies have quantified the accelerated degradation induced by storage sharing or incorporated State of Health (SoH) into storage sharing management. Therefore, we propose a health-aware energy management strategy in the environment of IoS, enabling distributed storage systems to cooperate through information and communication technology. To evaluate the SoH of storage, we design a health-aware framework based on equivalent circuit model (ECM), in which SoH can be derived from the charging behavior of battery. Consequently, the internal resistance, capacity, efficiency, and state of power can be inferred by SoH. To demonstrate the effectiveness of the proposed strategy, three benchmarks, i.e., local health-unaware model, local health-aware model, and Health-unaware Sharing (HuS) model are designed. Case studies based on 600 residential customers in Texas, USA reveal that IoS will cause additional SoH degradation, and the life of energy storage is reduced by 3.01 years. The proposed strategy can extend the energy storage’s service life by 43.13% and has better economic benefits compared with traditional HuS. DA - 2023/5/1/ PY - 2023/5/1/ DO - 10.1109/JIOT.2022.3173488 VL - 10 IS - 9 SP - 7545-7553 SN - 2327-4662 KW - Battery management system KW - energy sharing KW - Internet of Storage (IoS) KW - State of Health (SoH) ER - TY - JOUR TI - Power Flow Optimization Redesign for Transient Stability Enhancement AU - Chakraborty, Rahul AU - Chakrabortty, Aranya AU - Osipov, Denis AU - Chow, Joe H. T2 - 2023 IEEE POWER & ENERGY SOCIETY INNOVATIVE SMART GRID TECHNOLOGIES CONFERENCE, ISGT AB - We develop an optimization program referred to as the $H_{2}$ -power flow modification $(H_{2}$ -pfm) that utilizes the potential of inverter-based resources (IBRs) for improving damping of the electro-mechanical dynamics of a power system, and, in turn, enhances its transient stability radius as well. The method tunes the active and reactive power setpoints of the IBRs generated from the standard AC-OPF solution to optimize the $\mathbf{H}_{2}$ -norm of the transfer function of the grid model considering any incoming disturbance as the input and the generator rotor speeds as the outputs. Power transfer distribution factors (PTDFs) are used to identify the most relevant sets of tunable setpoints to reduce the search space, thereby making the problem solvable online. Simulation results are shown using a 16-machine, 68-bus New York power system model integrated with 7 wind farms. Results indicate that $H_{2}$ - PFM leads to notable improvement in transient stability compared to that for nominal AC-OPF. DA - 2023/// PY - 2023/// DO - 10.1109/ISGT51731.2023.10066339 SP - SN - 2167-9665 KW - Inverter-based resources KW - optimal power flow KW - stability index KW - transient stability KW - wind farms ER - TY - JOUR TI - Climate-smart forestry through innovative wood products and commercial afforestation and reforestation on marginal land AU - Zhang, Bingquan AU - Lan, Kai AU - Harris, Thomas B. AU - Ashton, Mark S. AU - Yao, Yuan T2 - Proceedings of the National Academy of Sciences AB - Afforestation and reforestation (AR) on marginal land are nature-based solutions to climate change. There is a gap in understanding the climate mitigation potential of protection and commercial AR with different combinations of forest plantation management and wood utilization pathways. Here, we fill the gap using a dynamic, multiscale life cycle assessment to estimate one-century greenhouse gas (GHG) mitigation delivered by (both traditional and innovative) commercial and protection AR with different planting density and thinning regimes on marginal land in the southeastern United States. We found that innovative commercial AR generally mitigates more GHGs across 100 y (3.73 to 4.15 Giga tonnes of CO2 equivalent (Gt CO2e)) through cross-laminated timber (CLT) and biochar than protection AR (3.35 to 3.69 Gt CO2e) and commercial AR with traditional lumber production (3.17 to 3.51 Gt CO2e), especially in moderately cooler and dryer regions in this study with higher forest carbon yield, soil clay content, and CLT substitution. In a shorter timeframe (≤50 y), protection AR is likely to deliver higher GHG mitigation. On average, for the same wood product, low-density plantations without thinning and high-density plantations with thinning mitigate more life cycle GHGs and result in higher carbon stock than that of low-density with thinning plantations. Commercial AR increases the carbon stock of standing plantations, wood products, and biochar, but the increases have uneven spatial distributions. Georgia (0.38 Gt C), Alabama (0.28 Gt C), and North Carolina (0.13 Gt C) have the largest carbon stock increases that can be prioritized for innovative commercial AR projects on marginal land. DA - 2023/6/6/ PY - 2023/6/6/ DO - 10.1073/pnas.2221840120 UR - https://doi.org/10.1073/pnas.2221840120 ER - TY - JOUR TI - Electrode-Potential-Driven Dissociation of N-Heterocycle/BF3 Adducts: A Possible Manifestation of the Electro-Inductive Effect AU - Hossain, Md. Sazzad AU - Romo, Adolfo I. B. AU - Putnam, Seth T. AU - Dawlaty, Jahan AU - Augustyn, Veronica AU - Rodriguez-Lopez, Joaquin T2 - ANGEWANDTE CHEMIE-INTERNATIONAL EDITION AB - Recently, non-Faradaic effects were used to modify the electronic structure and reactivity of electrode-bound species. We hypothesize that these electrostatic perturbations could influence the chemical reactivity of electrolyte species near an electrode in the absence of Faradaic electron transfer. A prime example of non-Faradaic effects is acid-base dissociation near an interface. Here, we probed the near-electrode dissociation of N-heterocycle-BF3 Lewis adducts upon electrode polarization, well outside of the redox potential window of the adducts. Using scanning electrochemical microscopy and confocal fluorescence spectroscopy, we detected a potential-dependent depletion of the adduct near the electrode. We propose an electro-inductive effect where a more positive potential leads to electron withdrawal on the N-heterocycle. This study takes a step forward in the use of electrostatics at electrochemical interfaces for field-driven electrocatalytic and electro-synthetic processes. DA - 2023/5/4/ PY - 2023/5/4/ DO - 10.1002/anie.202304218 SP - SN - 1521-3773 KW - Adduct KW - Electro-Inductive Effect KW - Electrostatics KW - Fluorescence KW - Scanning Electrochemical Microscopy ER - TY - JOUR TI - Institutional stability and change in environmental governance AU - Galik, Christopher S. AU - Ba, Yuhao AU - Bobbitt, Christopher T2 - POLICY AND POLITICS AB - Efforts to better understand what prevents institutions from changing to meet contemporary demands – or what facilitates the evolution of existing constructs to address new challenges – are of particular import and relevance to environmental governance. While the existing literature provides valuable conceptualisation and empirical evaluation of institutional stability and change, the lack of a consistent and holistic typology complicates the evaluation of institutions over time. In this article, we use a combined stability–change typology to assess the dominant modes of institutional change and stability over a multi-decadal timespan across three environmental governance systems – air quality governance in the US and China, and climate governance in the European Union. Across cases, we find that these modes are not mutually exclusive but can occur simultaneously, in concert or in conflict. We also find that observed patterns of change and stability are reflective of the social and political context in which systems operate, as well as the focus of the system itself (for example, localised air quality versus global climate change). Apart from providing a proof-of-concept analysis of institutional change and stability, our findings raise questions about the mechanisms underlying spatial and temporal patterns across identified modes. Indirectly, our findings also further highlight challenges to designing systems both resilient to exogenous stressors and capable of adapting to new situations. Our combined stability–change typology may help to advance understanding of whether and how such balancing has occurred in the past, thus facilitating future efforts to address contemporary challenges. DA - 2023/5/8/ PY - 2023/5/8/ DO - 10.1332/030557321X16806127945591 VL - 5 SP - SN - 1470-8442 KW - environmental policy KW - climate policy KW - climate governance KW - institutional change KW - air pollution KW - Clean Air Act KW - Emission Trading System ER - TY - JOUR TI - Tiger protection brings carbon benefits AU - Sills, Erin O. AU - Kramer, Randall A. T2 - NATURE ECOLOGY & EVOLUTION DA - 2023/5/25/ PY - 2023/5/25/ DO - 10.1038/s41559-023-02062-4 VL - 5 SP - SN - 2397-334X UR - https://doi.org/10.1038/s41559-023-02062-4 ER - TY - JOUR TI - Frameworks, methods and evidence connecting modern domestic energy services and gender empowerment AU - Das, Ipsita AU - Klug, Thomas AU - Krishnapriya, P. P. AU - Plutshack, Victoria AU - Saparapa, Rajah AU - Scott, Stephanie AU - Sills, Erin AU - Kara, Njeri AU - Pattanayak, Subhrendu K. AU - Jeuland, Marc T2 - NATURE ENERGY DA - 2023/4/6/ PY - 2023/4/6/ DO - 10.1038/s41560-023-01234-7 VL - 4 SP - SN - 2058-7546 ER - TY - JOUR TI - Analysis and Design Considerations of Input Parallel Output Series-Phase Shifted Full Bridge Converter for a High-Voltage Capacitor Charging Power Supply System AU - Agarwal, Apoorv AU - Prabowo, Yos AU - Bhattacharya, Subhashish T2 - IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS AB - Capacitor charging power supply (CCPS) is used for impulse-power applications such as electromagnetic rail guns, flash lamps, medical sterilization, and rock crushing, among many other application fields. This article describes the design and analysis of an Input Parallel Output Series-Phase Shifted Full Bridge converter for CCPS. The proposed system has a low output current ripple to improve the lifetime of the high-voltage pulsed capacitor. Design considerations of topology's electrical parameters such as HF transformer's leakage inductor and output inductor for the CCPS application are presented. The intermediate DC-link capacitance is provided as an energy storage element to minimize the disturbances (power variation) on the source for the CCPS application. Analysis and sizing of the capacitance for two different charging methods are analyzed and compared. A controller design procedure for the Active Front End Converter (AFEC) is also included to ensure near-constant power drawn, rejecting the load disturbances. Finally, a complete design procedure for the whole CCPS system is presented. Design and simulation results are presented for a rated system, followed by experimental results from a scaled-down hardware prototype to validate the design. DA - 2023/9// PY - 2023/9// DO - 10.1109/TIA.2023.3276353 VL - 59 IS - 5 SP - 6037-6050 SN - 1939-9367 UR - https://doi.org/10.1109/TIA.2023.3276353 KW - Capacitor charging power supply KW - constant current KW - constant power KW - HV capacitor KW - intermediate DC-link capacitor KW - input parallel output series-phase shifted full bridge (IPOS-PSFB) ER - TY - JOUR TI - The Health and Climate Benefits of Economic Dispatch in China?s Power System AU - Luo, Qian AU - Garcia-Menendez, Fernando AU - Yang, Haozhe AU - Deshmukh, Ranjit AU - He, Gang AU - Lin, Jiang AU - Johnson, Jeremiah X. T2 - ENVIRONMENTAL SCIENCE & TECHNOLOGY DA - 2023/2/9/ PY - 2023/2/9/ DO - 10.1021/acs.est.2c056632898 VL - 57 IS - 7 SP - 2898-2906 SN - 1520-5851 KW - power system in China KW - air pollution KW - public health ER - TY - JOUR TI - Chitosan-Fe3O4 composites enhance anaerobic digestion of liquor wastewater under acidic stress AU - Nie, Wenkai AU - Lin, Yan AU - Wu, Xin AU - Wu, Shaohua AU - Li, Xiang AU - Cheng, Jay J. AU - Yang, Chunping T2 - BIORESOURCE TECHNOLOGY AB - Acid stress in the anaerobic digestion process of liquor wastewater leads to low anaerobic treatment efficiency. Herein, chitosan-Fe3O4 was prepared, and its effects on anaerobic digestion processes under acid stress were studied. Results showed that chitosan-Fe3O4 increased the methanogenesis rate of anaerobic digestion of acidic liquor wastewater by 1.5-2.3 times and accelerated the restoration of acidified anaerobic systems. The analysis of sludge characteristics showed that chitosan-Fe3O4 promoted the secretion of proteins and humic substances in extracellular polymeric substances and increased the electron transfer activity of the system by 71.4%. Microbial community analysis indicated that chitosan-Fe3O4 enriched the abundance of Peptoclostridium, and Methanosaeta participated in direct interspecies electron transfer. Chitosan-Fe3O4 could promote the direct interspecies electron transfer pathway to maintain stable methanogenesis. These methods and results regarding the use of chitosan-Fe3O4 could be referred to for improving the efficiency of anaerobic digestion of high concentration organic wastewater under acid inhibition. DA - 2023/6// PY - 2023/6// DO - 10.1016/j.biortech.2023.128927 VL - 377 SP - SN - 1873-2976 KW - Anaerobic digestion KW - Acid inhibition KW - Biogas KW - Liquor wastewater KW - Volatile fatty acid ER - TY - JOUR TI - Designing Optimal Key Lengths and Control Laws for Encrypted Control Systems Based on Sample Identifying Complexity and Deciphering Time AU - Teranishi, Kaoru AU - Sadamoto, Tomonori AU - Chakrabortty, Aranya AU - Kogiso, Kiminao T2 - IEEE TRANSACTIONS ON AUTOMATIC CONTROL AB - In the state-of-the-art literature on cryptography and control theory, there has been no systematic methodology of constructing cyber–physical systems that can achieve the desired control performance while being protected against eavesdropping attacks. In this article, we tackle this challenging problem. We first propose two novel notions referred to as sample identifying complexity and sample deciphering time in an encrypted control framework. The former explicitly captures the relation between the dynamical characteristics of control systems and the level of identifiability of the systems while the latter shows the relation between the computation time for the identification and the key length of a cryptosystem. Based on these two tractable new notions, we propose a systematic method for designing both of an optimal key length to prevent system identification with a given precision within a given life span of systems and of an optimal controller to maximize both of the control performance and the difficulty of the identification. The efficiency of the proposed method in terms of security level and realtime-ness is investigated through numerical simulations. To the best of our knowledge, this article first connects the relationship between the security of cryptography and dynamical systems from a control-theoretic perspective. DA - 2023/4// PY - 2023/4// DO - 10.1109/TAC.2022.3174691 VL - 68 IS - 4 SP - 2183-2198 SN - 1558-2523 KW - Cryptography KW - Security KW - Control systems KW - Eavesdropping KW - Complexity theory KW - Homomorphic encryption KW - Estimation KW - Cyber-physical system KW - cyber-security KW - eavesdropping attack KW - encrypted control KW - homomorphic encryption KW - system identification ER - TY - JOUR TI - A Secure and Adaptive Hierarchical Multi-Timescale Framework for Resilient Load Restoration Using a Community Microgrid AU - Shirsat, Ashwin AU - Muthukaruppan, Valliappan AU - Hu, Rongxing AU - Paduani, Victor Daldegan AU - Xu, Bei AU - Song, Lidong AU - Li, Yiyan AU - Lu, Ning AU - Baran, Mesut AU - Lubkeman, David AU - Tang, Wenyuan T2 - IEEE TRANSACTIONS ON SUSTAINABLE ENERGY AB - Distribution system integrated community microgrids (CMGs) can partake in restoring loads during extended duration outages. At such times, the CMGs are challenged with limited resource availability, absence of robust grid support, and heightened demand-supply uncertainty. This paper proposes a secure and adaptive three-stage hierarchical multi-timescale framework for scheduling and real-time (RT) dispatch of CMGs with hybrid PV systems to address these challenges. The framework enables the CMG to dynamically expand its boundary to support the neighboring grid sections and is adaptive to the changing forecast error impacts. The first stage solves a stochastic extended duration scheduling (EDS) problem to obtain referral plans for optimal resource rationing. The intermediate near-real-time (NRT) scheduling stage updates the EDS schedule closer to the dispatch time using new obtained forecasts, followed by the RT dispatch stage. To make the decisions more secure and robust against forecast errors, a novel concept called delayed recourse is designed. The approach is evaluated via numerical simulations on a modified IEEE 123-bus system and validated using OpenDSS and hardware-in-loop simulations. The results show superior performance in maximizing load supply and continuous secure distribution network operation under different operating scenarios. DA - 2023/4// PY - 2023/4// DO - 10.1109/TSTE.2023.3251099 VL - 14 IS - 2 SP - 1057-1075 SN - 1949-3037 KW - Active distribution networks KW - community microgrids KW - hybrid PV systems KW - load restoration KW - high-impact low-frequency events KW - secure operation KW - uncertainty KW - resiliency ER - TY - JOUR TI - Simple Diesel Train Fuel Consumption Model for Real-Time Train Applications AU - Ahn, Kyoungho AU - Aredah, Ahmed AU - Rakha, Hesham A. AU - Wei, Tongchuan AU - Frey, H. Christopher T2 - ENERGIES AB - This paper introduces a simple diesel train energy consumption model that calculates the instantaneous energy consumption using vehicle operational input variables, including the instantaneous speed, acceleration, and roadway grade, which can be easily obtained from global positioning system (GPS) loggers. The model was tested against real-world data and produced an error of −1.33% for all data and errors ranging from −12.4% to +8.0% for energy consumption of four train datasets amounting to a total of 5854 km trips. The study also validated the proposed model with separate data that were collected between Valencia and Cuenca, Spain, which had a total length of 198 km and found that the model was accurate, yielding a relative error of −1.55% for the total energy consumption. These results show that the proposed model can be used by train operators, transportation planners, policy makers, and environmental engineers to evaluate the energy consumption effects of train operational projects and train simulation within intermodal transportation planning tools. DA - 2023/4// PY - 2023/4// DO - 10.3390/en16083555 VL - 16 IS - 8 SP - SN - 1996-1073 UR - https://doi.org/10.3390/en16083555 KW - diesel train KW - energy consumption model KW - train simulation ER - TY - JOUR TI - Passive CM Filter Configuration for a Multistage Grid-Tied Solid State Transformer AU - Gulur, Srinivas AU - Iyer, Vishnu Mahadeva AU - Bhattacharya, Subhashish T2 - IEEE Journal of Emerging and Selected Topics in Industrial Electronics AB - This work proposes a common mode (CM) filter configuration for a grid-tied two-stage ac/dc solid state transformer (SST). The proposed CM filter utilizes passive components along with the heat-sinks of the individual power converter stages to mitigate the overall conducted emissions (CE) injected by the SST system into the grid. The working principle of the proposed CM filter is analyzed and elucidated using CM equivalent circuit models. In addition to CE reduction with the proposed CM filter, it is also demonstrated that the heat-sinks of the SST system can be closer to ground-potential while being impedance grounded. The effectiveness of the proposed CM filter is validated by experimentally measuring the CE of the grid-tied SST system using a line impedance stabilization network. DA - 2023/7// PY - 2023/7// DO - 10.1109/JESTIE.2023.3268623 UR - https://doi.org/10.1109/JESTIE.2023.3268623 ER - TY - JOUR TI - Mechanically robust, thermally insulating and photo-responsive aerogels designed from sol-gel electrospun PVP-TiO2 nanofibers AU - Rahmanian, Vahid AU - Pirzada, Tahira AU - Barbieri, Eduardo AU - Iftikhar, Sherafghan AU - Li, Fanxing AU - Khan, Saad A. T2 - APPLIED MATERIALS TODAY AB - We present a robust approach for fabricating polyvinylpyrrolidone (PVP)-titania (TiO2) nanofibrous aerogels (NFA) with multifunctional and triggered performances. These low density (∼ 10 mg cm−3) 3D self-supported aerogels having an intrinsically lamellar porous structure (> 99% porosity) are created via solid templating of sol-gel electrospun PVP-TiO2 hybrid nanofibers. The photocatalytic activity of TiO2 allows for on-demand application wherein the aerogel exhibits antibacterial properties upon UV exposure to bacteria such as Escherichia coli and Salmonella enterica. Significantly, while the aerogel sorbs common volatile organic components (VOCs) or oil due to its innate porosity, exposure of the aerogel to ultraviolet (UV) radiation leads to their decomposition. The PVP-TiO2 NFA exhibits a low thermal conductivity (0.062 W m−1 K−1) together with considerable mechanical flexibility up to strains of 50% with >90% recovery, without the need for post-processing. The photo-responsive attributes combined with mechanical resilience, oleophilicity and thermal insulation properties render these aerogels viable candidates for a diverse range of applications. We discuss such property enhancements in terms of the interaction between PVP and TiO2 and aerogel microstructure. DA - 2023/6// PY - 2023/6// DO - 10.1016/j.apmt.2023.101784 VL - 32 SP - SN - 2352-9407 KW - Hybrid aerogel KW - Titania KW - Antibacterial KW - VOC decomposition KW - Thermal insulation KW - Oil-water separation ER - TY - JOUR TI - Nitrogen Fixation and Ammonium Assimilation Pathway Expression of Geobacter sulfurreducens Changes in Response to the Anode Potential in Microbial Electrochemical Cells AU - Ortiz-Medina, Juan F. AU - Poole, Mark R. AU - Grunden, Amy M. AU - Call, Douglas F. T2 - APPLIED AND ENVIRONMENTAL MICROBIOLOGY AB - Biological nitrogen fixation coupled with ammonium recovery provides a sustainable alternative to the carbon-, water-, and energy-intensive Haber-Bosch process. Aerobic biological nitrogen fixation technologies are hindered by oxygen gas inhibition of the nitrogenase enzyme. DA - 2023/3/28/ PY - 2023/3/28/ DO - 10.1128/aem.02073-22 SP - SN - 1098-5336 KW - electromicrobiology KW - Geobacter KW - nitrogen fixation ER - TY - JOUR TI - Solid-State Transformer Based on Naturally Cell Balanced Series Resonant Converter With Cascaded H-Bridge Cells Switched at Grid Frequency AU - Bhawal, Shekhar AU - Patel, Himanshu AU - Hatua, Kamalesh AU - Vasudevan, Krishna AU - Bhattacharya, Subhashish T2 - IEEE TRANSACTIONS ON POWER ELECTRONICS AB - This article proposes a closed-loop control architecture for a three-stage [medium-voltage (MV), isolated dc/dc, low-voltage (LV)] solid-state transformer (SST) system and a modulation technique for the MV stage that shows better performance over existing solutions in terms of control simplicity, semiconductor loss, and cost. A simple and effective closed-loop control architecture is proposed for the entire SST system using the natural cell balancing ability of the series resonant dual-active bridge converters in the dc/dc stage. In order to reduce semiconductor losses and cost, Si insulated-gate bipolar transistor and SiC mosfet devices are introduced properly in the MV stage of the SST power architecture, and the proposed modulation technique switches these devices appropriately according to their merits. The proposed modulation scheme ensures more than 50% semiconductor loss reduction in the MV stage. A circulating logic is proposed to achieve equal power sharing among cells in the MV stage and associated components. Detailed dynamic modeling, closed-loop control architecture, and modulation scheme are discussed in this article. The proposed control technique and modulation scheme are verified experimentally in a 600-/100-V, 5-kW SST system. DA - 2023/7// PY - 2023/7// DO - 10.1109/TPEL.2023.3263754 VL - 38 IS - 7 SP - 8208-8222 SN - 1941-0107 UR - https://doi.org/10.1109/TPEL.2023.3263754 KW - Cascaded H-bridge (CHB) KW - circulating logic KW - line-frequencymode KW - series resonant dual active bridge (SRDAB) KW - solid-state transformer (SST) ER - TY - JOUR TI - Generalizing Reservoir Operations using a Piecewise Classification and Regression Approach AU - Ford, Lucas AU - Sankarasubramanian, Arumugam AB - Inflow anomalies at varying temporal scales, seasonally varying storage mandates, and multi-purpose allocation requirements contribute to reservoir operational decisions. The difficulty of capturing these constraints across many basins in a generalized framework has limited the accuracy of streamflow estimates in Land Surface Models for locations downstream of reservoirs. We develop a Piece Wise Linear Regression Tree to learn generalized daily operating policies from 76 reservoirs from four major basins across the coterminous US. Reservoir characteristics, such as residence time and maximum storage, and daily state variables, such as storage and inflow, are used to group similar observations across all reservoirs. Linear regression equations are then fit between daily state variables and release for each group. We recommend two models – Model 1 (M1) that performs the best when simulating untrained records but is complex, and Model 2 (M2) that is nearly as performant as M1 but more parsimonious. The simulated release median root mean squared error is 49.7% (53.2%) of mean daily release with a median Nash-Sutcliffe Efficiency of 0.62 (0.52) for M1 (M2). Long-term residence time is shown to be useful in grouping similar operating reservoirs. Release from low residence time reservoirs can be mostly described using inflow-based variables. Operations at higher residence time reservoirs are more related to previous release variables or storage variables, depending on the current inflow. The ability of the models presented to capture operational dynamics of many types of reservoirs indicates their potential to be used for untrained and limited data reservoirs. DA - 2023/3/26/ PY - 2023/3/26/ DO - 10.22541/essoar.167979630.09661764/v1 UR - https://doi.org/10.22541/essoar.167979630.09661764/v1 ER - TY - JOUR TI - Accelerated Perovskite Oxide Development for Thermochemical Energy Storage by a High-Throughput Combinatorial Approach AU - Cai, Runxia AU - Bektas, Hilal AU - Wang, Xijun AU - McClintock, Kyle AU - Teague, Lauren AU - Yang, Kunran AU - Li, Fanxing T2 - ADVANCED ENERGY MATERIALS AB - Abstract The structural and compositional flexibility of perovskite oxides and their complex yet tunable redox properties offer unique optimization opportunities for thermochemical energy storage (TCES). To improve the relatively inefficient and empirical‐based approaches, a high‐throughput combinatorial approach for accelerated development and optimization of perovskite oxides for TCES is reported here. Specifically, thermodynamic‐based screening criteria are applied to the high‐throughput density functional theory (DFT) simulation results of over 2000 A/B‐site doped SrFeO 3− δ . 61 promising TCES candidates are selected based on the DFT prediction. Of these, 45 materials with pure perovskite phases are thoroughly evaluated. The experimental results support the effectiveness of the high‐throughput approach in determining both the oxygen capacity and the oxidation enthalpy of the perovskite oxides. Many of the screened materials exhibit promising performance under practical operating conditions: Sr 0.875 Ba 0.125 FeO 3− δ exhibits a chemical energy storage density of 85 kJ kg ABO3 −1 under an isobaric condition (with air) between 400 and 800 °C whereas Sr 0.125 Ca 0.875 Fe 0.25 Mn 0.75 O 3− δ demonstrates an energy density of 157 kJ kg ABO3 −1 between 400 °C/0.2 atm O 2 and 1100 °C/0.01 atm O 2 . An improved set of optimization criteria is also developed, based on a combination of DFT and experimental results, to improve the effectiveness for accelerated development of redox‐active perovskite oxides. DA - 2023/3/22/ PY - 2023/3/22/ DO - 10.1002/aenm.202203833 VL - 3 SP - SN - 1614-6840 UR - https://doi.org/10.1002/aenm.202203833 KW - energy storage KW - high-throughput screening KW - mixed oxides KW - perovskites KW - redox ER - TY - JOUR TI - The Health and Climate Benefits of Economic Dispatch in China's Power System AU - Luo, Qian AU - Garcia-Menendez, Fernando AU - Yang, Haozhe AU - Deshmukh, Ranjit AU - He, Gang AU - Lin, Jiang AU - Johnson, Jeremiah X. T2 - ENVIRONMENTAL SCIENCE & TECHNOLOGY AB - China's power system is highly regulated and uses an "equal-share" dispatch approach. However, market mechanisms are being introduced to reduce generation costs and improve system reliability. Here, we quantify the climate and human health impacts brought about by this transition, modeling China's power system operations under economic dispatch. We find that significant reductions in mortality related to air pollution (11%) and CO2 emissions (3%) from the power sector can be attained by economic dispatch, relative to the equal-share approach, through more efficient coal-powered generation. Additional health and climate benefits can be achieved by incorporating emission externalities in electricity generation costs. However, the benefits of the transition to economic dispatch will be unevenly distributed across China and may lead to increased health damage in some regions. Our results show the potential of dispatch decision-making in electricity generation to mitigate the negative impacts of power plant emissions with existing facilities in China. DA - 2023/2/9/ PY - 2023/2/9/ DO - 10.1021/acs.est.2c05663 SP - SN - 1520-5851 KW - power system in China KW - air pollution KW - public health ER - TY - JOUR TI - The BiDFET Device and Its Impact on Converters AU - Baliga, B. Jayant AU - Hopkins, Douglas AU - Bhattacharya, Subhashish AU - Agarwal, Aditi AU - Cheng, Tzu-Hsuan AU - Narwal, Ramandeep AU - Kanale, Ajit AU - Shah, Suyash Sushilkumar AU - Han, Kijeong T2 - IEEE POWER ELECTRONICS MAGAZINE AB - The matrix converter topology for direct ac-to-ac conversion offers elimination of the bulky and unreliable d.c. link capacitors used in the popular voltage-source inverter (VSI) with a front-end rectifier. The resulting more compact and higher efficiency implementation is a desirable solution for a wide variety of applications, such as photovoltaic energy generation, motor drives, and energy storage systems. DA - 2023/3// PY - 2023/3// DO - 10.1109/MPEL.2023.3237059 VL - 10 IS - 1 SP - 20-27 SN - 2329-9215 UR - https://doi.org/10.1109/MPEL.2023.3237059 KW - Photovoltaic systems KW - Motor drives KW - Capacitors KW - Rectifiers KW - Inverters KW - Topology KW - Matrix converters ER - TY - JOUR TI - Power Conversion Systems Enabled by SiC BiDFET Device AU - Bhattacharya, Subhashish AU - Narwal, Ramandeep AU - Shah, Suyash Sushilkumar AU - Baliga, B. Jayant AU - Agarwal, Aditi AU - Kanale, Ajit AU - Han, Kijeong AU - Hopkins, Douglas C. AU - Cheng, Tzu-Hsuan T2 - IEEE POWER ELECTRONICS MAGAZINE AB - The BiDirectional Field-Effect Transistor (BiDFET) can enable circuit topologies requiring four-quadrant switches, that were earlier designed using discrete combinations of MOSFETs, IGBTs, GaN HEMTs, and PiN diodes. The monolithic nature of the BiDFET allows lower device count, smaller switch volume, lower inductance, and simpler packaging, and hence more reliable and commercially viable implementation in power electronics converters. The matrix converter topologies, now feasible using BiDFETs, can eliminate the bulky and unreliable dc link capacitors or inductors required for conventional voltage-source or current-source converters in ac–ac and ac–dc applications. The 1.2 kV BiDFET has the potential to disrupt all the applications utilizing 1.2 kV switches, including electric vehicle (EV) drivetrain, bidirectional EV chargers, industrial motor drives, solid-state transformers, datacenter power supplies, elevator drives, dc microgrids, energy storage grid integration, solid-state breakers, etc. DA - 2023/3// PY - 2023/3// DO - 10.1109/MPEL.2023.3237060 VL - 10 IS - 1 SP - 39-43 SN - 2329-9215 UR - https://doi.org/10.1109/MPEL.2023.3237060 KW - Motor drives KW - Silicon carbide KW - Power supplies KW - PIN photodiodes KW - Switches KW - Packaging KW - Transformers ER - TY - JOUR TI - Cupric ions inducing dynamic hormesis in duckweed systems for swine wastewater treatment: Quantification, modelling and mechanisms AU - Li, Chengxi AU - Lin, Yan AU - Li, Xiang AU - Cheng, Jay J. AU - Yang, Chunping T2 - SCIENCE OF THE TOTAL ENVIRONMENT AB - Hormesis has attracted close attention of environmental and toxicological communities over the past decades. Most studies focused on the hormesis induced by stressors in the aspect of their biotoxicity to organisms, while little research was conducted on hormesis in the aspect of biological wastewater treatment process. In this study, removal of NH4+-N and Cu2+ by S. polyrrhiza under long-term Cu2+ exposure at environmentally relevant concentrations in swine wastewater was investigated. Removal efficiencies of NH4+-N by duckweeds at 0.0, 0.1, 0.5, 1.0, 2.0 and 4.0 mg/L Cu2+ were 81.6 %, 83.7 %, 89.4 %, 74.9 %, 61.8 % and 45.1 % on day 28, however, during the initial period of cultivation (0-4 days), such hormetic effect was not observed, indicating time-dependent feature of hormesis in NH4+-N removal. The modified logistic growth model was applied to describe long-term hormesis induced by Cu2+ on NH4+-N removal and it suggested that the optimal copper exposure for ammonium removal was 0.48 mg/L. More importantly, it was found that previous exposure to low doses of Cu2+ (0-1 mg/L) could enhance NH4+-N removal performance under the second exposure. Cu2+ above 1 mg/L could switch copper bioaccumulation pattern from the Langmiur-irreversible type to reversible one, indicating risk of secondary pollution. Six components including freshly-produced humic-like substances, lignin, fulvic acid-protein complex, free amino acid-like substances, tyrosine-like substance and soluble amino acid-like substances in duckweeds were detected by parallel factor (PARAFAC) model detected. Principle component analysis (PCA) conducted on PARAFAC components suggested that enhanced synthesis of protein and growth factors intracellularly at low dose stimulation improved ammonia uptake from the environment. This study provided a novel strategy to improve treatment performance of duckweeds for copper contaminated wastewater and helped understand biochemical responses and their roles in evolutionary adaptive strategies to stresses. DA - 2023/3/25/ PY - 2023/3/25/ DO - 10.1016/j.scitotenv.2023.161411 VL - 866 SP - SN - 1879-1026 KW - Copper KW - Phytoremediation KW - Hormesis KW - Duckweed KW - Antioxidant defense ER - TY - JOUR TI - Blade element momentum theory for a skewed coaxial turbine AU - Elfering, Kelsey AU - Metoyer, Rodney AU - Chatterjee, Punnag AU - Mazzoleni, Andre AU - Bryant, Matthew AU - Granlund, Kenneth T2 - OCEAN ENGINEERING AB - A coaxial turbine under skew with significant rotor spacing has the potential for increased power output compared to a flow-aligned turbine due to a portion of the downstream rotor experiencing freestream velocity, referred to as a fresh flow region. A lab-scale prototype was designed and built to investigate the skew-to-power relationship of a coaxial turbine system as it compared to a blade element momentum theory model with multiple, sheared streamtubes representing the downstream rotor fresh flow region. The inclusion of the downstream rotor fresh flow region in the theoretical analysis is compared to the experimental data. The results support that the torque and power performance of the downstream rotor and overall skewed coaxial turbine system are predicted more accurately. DA - 2023/2/1/ PY - 2023/2/1/ DO - 10.1016/j.oceaneng.2022.113555 VL - 269 SP - SN - 1873-5258 KW - Skew KW - Hydrokinetic energy KW - Coaxial turbines KW - Counter-rotating turbines KW - Blade element momentum theory ER - TY - JOUR TI - A Control Method to Reduce Overshoots in High-Frequency Link Current and Voltages at Load Transients of a Dual-Active-Bridge Series-Resonant Converter AU - Chakraborty, Surja Sekhar AU - Hatua, Kamalesh AU - Bhattacharya, Subhashish T2 - IEEE Journal of Emerging and Selected Topics in Industrial Electronics AB - A dual-active-bridge (DAB) series-resonant converter is well researched in the literature to find out a suitable pulsewidth modulation (PWM) technique that can achieve voltage regulation, zero-voltage switching, and minimum root-mean-square current in the high-frequency (HF) link. Although the advanced PWM techniques achieve desired performance at steady state, the HF link current and voltages suffer from huge overshoots during load transients, which can damage semiconductor devices and can cause the saturation of the high-frequency transformer. Therefore, in this article, a relationship between the pole positions and the percentage overshoot is derived, so that any design with the tradeoff between fast dynamics and overshoot can be done analytically. As the system involves multiple state and input variables, which are also closely coupled, a multivariable state-feedback controller design is proposed to control the dynamics of all the HF link state variables simultaneously. In any DAB-based topology, the peak volt-ampere rating of the passive components can increase by 80% due to these overshoots. The proposed control successfully restricts the overshoots below 25% with a settling time of 5 ms for the output voltage. The experimental verification is carried out in a 2.25-kW hardware prototype. DA - 2023/4// PY - 2023/4// DO - 10.1109/JESTIE.2023.3243844 UR - https://doi.org/10.1109/JESTIE.2023.3243844 ER - TY - JOUR TI - Improved National-Scale Flood Prediction for Gauged and Ungauged Basins using a Spatio-temporal Hierarchical Model AU - Fang, Shiqi AU - Johnson, J. Michael AU - Yeghiazarian, Lilit AU - Sankarasubramanian, Arumugam AB - Floods cause hundreds of fatalities and billions of dollars of economic loss each year in the United States. To mitigate these damages, accurate flood prediction is needed for issuing early warnings to the public. This situation is exacerbated in larger model domains for high flows, particularly in ungauged basins. To improve flood prediction for both gauged and ungauged basins, we propose a spatio-temporal hierarchical model (STHM) to improve high flow estimation using a 10-day window of modeled National Water Model (NWM) streamflow and a variety of catchment characteristics as input. The STHM is calibrated (1993-2008) and validated (2009-2018) in controlled, natural, and coastal basins over three broad groups, and shows significant improvement for the first two basin types. A seasonal analysis shows the most influential predictors are the previous 3-day average streamflow and the aridity index for controlled and natural basins, respectively. To evaluate the STHM in improving streamflow in ungauged basins, 20-fold cross-validation is performed by leaving 5% of sites. Results show that the STHM increases predictive skill in over 50% of sites by 0.1 Nash-Sutcliffe efficiency (NSE) and improves over 65% of sites’ streamflow prediction to an NSE>0.67, which demonstrates that the STHM is one of the first of its kind and could be employed for flood prediction in both gauged and ungauged basins. DA - 2023/2/9/ PY - 2023/2/9/ DO - 10.22541/essoar.167590827.70275868/v1 UR - https://doi.org/10.22541/essoar.167590827.70275868/v1 ER - TY - JOUR TI - Contribution of Cold Starts to Real-World Trip Emissions for Light-Duty Gasoline Vehicles AU - Hu, Jiangchuan AU - Frey, H. Christopher AU - Boroujeni, Behdad Yazdani T2 - ATMOSPHERE AB - For catalytic converter-equipped light-duty gasoline vehicles (LDGV), the hot-stabilized tailpipe emissions for pollutants such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) are well controlled. However, there are few reported real-world measurements of cold starts. Idling cold start and hot-stabilized trip exhaust emissions were measured for 37 LDGVs using a portable emissions measurement system (PEMS). Five vehicles were also measured for transient driving cold starts. On average, it took approximately 400, 150, 330, and 120 s to accumulate 90 percent of the idle cold start increments for fuel use, CO, HC, and NOx, respectively. Driving cold start increments were substantially higher than idling cold start increments, whereas cold start duration was typically shorter. For example, driving cold start contributed approximately 64%, 68%, 58%, and 4.5% of the trip total CO, HC, NOx, and carbon dioxide (CO2), respectively. This study is unique in quantifying the cold start contribution on a trip basis with real-world data. Although the cold start increment is sensitive to driving compared to idling, in either case, cold starts contribute substantially to total exhaust mass emissions. Furthermore, driver decisions regarding driving versus idle can substantially affect the contribution of cold starts, especially for CO and NOx. DA - 2023/1// PY - 2023/1// DO - 10.3390/atmos14010035 VL - 14 IS - 1 SP - SN - 2073-4433 KW - vehicle KW - emissions KW - measurement KW - exhaust KW - cold start KW - air pollution KW - gasoline ER - TY - JOUR TI - Aspen Plus simulation of Chemical Looping Combustion of syngas and methane in fluidized beds AU - Jasper, Micah AU - Shahbazi, Abolghasem AU - Schimmel, Keith AU - Li, Fanxing AU - Wang, Lijun T2 - Discover Chemical Engineering AB - Abstract Chemical Looping Combustion (CLC) is a technology that efficiently combines power generation and CO 2 capture. In CLC, the fuel is oxidized by a metal oxide called an oxygen carrier (OC). CLC uses two reactors: a fuel reactor and an air reactor. The fuel reactor oxidizes the fuel and reduces the OC. The air reactor oxidizes the OC using air and then the OC is cycled back to the fuel reactor. It is typical for both the fuel and the air reactors to be fluidized beds (FBs). In this research, an Aspen Plus model was developed to simulate a CLC system. Aspen Plus has recently included a built-in FB unit operation module. To our knowledge, no literature has been reported using this FB module for simulating fluidized bed combustion or gasification. This FB unit process was investigated in Aspen Plus and a kinetic based model was used and compared the simulation results to experimental data and the commonly used Gibbs equilibrium model. The FB unit and the kinetic model well fit the experimental data for syngas and methane combustion within 2% of the molar composition of syngas combustion and within 4% for the methane combustion. An advantage of this model over other kinetic models in literature is that the core shrinking model kinetic rate equations have been converted into a power law form. This allows Aspen Plus to use a calculator instead of an external Fortran compiler. This greatly simplifies the modeling process. The reaction rate equations are given for all reactions. A sensitivity analysis of the reaction kinetics was conducted. All data, code, and simulation files are given. DA - 2023/2/4/ PY - 2023/2/4/ DO - 10.1007/s43938-023-00020-x UR - https://doi.org/10.1007/s43938-023-00020-x ER - TY - JOUR TI - Mode Analysis, Transformer Saturation, and Fault Diagnosis Technique for an Open-Circuit Fault in a Three-Phase DAB Converter AU - Rastogi, Sagar Kumar AU - Shah, Suyash Sushilkumar AU - Singh, Brij N. AU - Bhattacharya, Subhashish T2 - IEEE TRANSACTIONS ON POWER ELECTRONICS AB - The three-phase dual active bridge (DAB3) is a popular dc–dc converter topology for high-power applications, capable of high-efficiency bidirectional power transfer with galvanic isolation. A single point of failure in power converters is the open-circuit fault (OCF) due to failure in a semiconductor device or its gate drive circuit. This study presents detailed waveform analyses for the normal- and the fault-mode operation. A novel logic-based fault diagnosis scheme is proposed based on the unique pattern in the dc bias of phase currents. Unlike previous schemes, the proposed scheme requires low-bandwidth current sensing only one side of the transformer to detect faults on either side, providing a cost and design benefit. Experimental results verify the analyses and the proposed identification scheme, detecting the fault within a few switching cycles. An in-depth study of the transformer under fault mode is presented for the first time, setting a guideline of time available for fault diagnosis and response. Experimental B–H curves and magnetizing currents of the three-phase transformer illustrate the cycle-by-cycle progression toward core saturation under fault mode. The study also reveals a new potential benefit of the three-phase DAB over the single-phase DAB; i.e., even in the presence of a secondary-side OCF, the DAB3 may continue to operate normally at full load. DA - 2023/6// PY - 2023/6// DO - 10.1109/TPEL.2023.3241654 VL - 38 IS - 6 SP - 7644-7660 SN - 1941-0107 UR - https://doi.org/10.1109/TPEL.2023.3241654 KW - DAB KW - dc-dc converter KW - detection KW - diagnosis KW - dual active bridge KW - fault KW - magnetization KW - mode analysis KW - open circuit fault (OCF) KW - saturation KW - three phase KW - transformer ER - TY - JOUR TI - Planning for winter peaking power systems in the United States AU - Keskar, Aditya AU - Galik, Christopher AU - Johnson, Jeremiah X. T2 - Energy Policy AB - Most regions in the United States experience peak electricity demand during the summer months. Several regions, however, are dual peaking with distinct summer and winter peaks of roughly equal magnitude. Deep decarbonization of our energy system could lead to greater instances of dual or winter peaking power systems across the country. This seasonal shift has important implications for grid operations. Furthermore, the compounding impacts of decarbonization strategies and climate change could introduce new challenges in ensuring sufficient generator availability during peak demand. This paper provides policy recommendations to plan for a shift to dual or winter peaking power systems. We first analyze the seasonal peak demand trends between 2016 and 2021 at the regional and subregional levels. We provide key examples of how regulators and system operators plan for winter resource adequacy, focusing on the measures undertaken by different stakeholders, post-Winter Storm Uri. We then detail challenges posed by the multilevel regulation framework in planning for winter peaking power systems for both extreme cold events and a gradual shift due to electrification. Finally, we provide our policy recommendations for utilities and regulators on how they can robustly meet the challenges of winter peaking systems. DA - 2023/2// PY - 2023/2// DO - 10.1016/j.enpol.2022.113376 VL - 173 SP - 113376 J2 - Energy Policy LA - en OP - SN - 0301-4215 UR - http://dx.doi.org/10.1016/j.enpol.2022.113376 DB - Crossref KW - Electricity regulation KW - Peak demand KW - Power system planning KW - Reliability ER - TY - JOUR TI - Historical industrial transitions influence local sustainability planning, capability, and performance AU - Ba, Yuhao AU - Galik, Christopher S. T2 - Environmental Innovation and Societal Transitions AB - We evaluate the influence of long-term industrial transitions on local sustainability action. We construct two aspects of historical industrial transitions—direction and magnitude—along with three aspects of local government sustainability action: planning, capabilities, and performance. Using a national survey of local sustainability practice and nearly five decades of historical manufacturing employment data in the U.S., we find local communities with more substantial swings in manufacturing jobs to be less likely to engage in sustainability planning, cultivate sustainability-related capabilities, and make progress towards meeting sustainability-related objectives, underscoring the potential challenges associated with top-down programs and the importance of decentralized solutions. DA - 2023/3// PY - 2023/3// DO - 10.1016/j.eist.2022.100690 VL - 46 SP - 100690 J2 - Environmental Innovation and Societal Transitions LA - en OP - SN - 2210-4224 UR - http://dx.doi.org/10.1016/j.eist.2022.100690 DB - Crossref KW - Sustainability transitions KW - Subnational governance KW - Manufacturing KW - County government KW - Historical institutionalism ER - TY - JOUR TI - Spectral Signatures of Flow Regime Alteration by Dams Across the United States AU - Chalise, Dol Raj AU - Sankarasubramanian, A. AU - Olden, Julian D. AU - Ruhi, Albert T2 - Earth's Future AB - Abstract River scientists strive to understand how streamflow regimes vary across space and time because it is fundamental to predicting the impacts of climate change and human activities on riverine ecosystems. Here we tested whether flow periodicity differs between rivers that are regulated or unregulated by large dams, and whether dominant periodicities change over time in response to dam regulation. These questions were addressed by calculating wavelet power at different timescales, ranging from 6 hr to 10 years, across 175 pairs of dam‐regulated and unregulated USGS gages with long‐term discharge data, spanning the conterminous United States. We then focused on eight focal reservoirs with high‐quality and high‐frequency data to examine the spectral signatures of dam‐induced flow alteration and their time‐varying nature. We found that regulation by dams induces changes not only in flow magnitude and variability, but also in the dominant periodicities of a river's flow regime. Our analysis also revealed that dams generally alter multi‐annual and annual periodicity to a higher extent than seasonal or daily periodicity. Based on the focal reservoirs, we illustrate that alteration of flow periodicity is time varying, with dam operations (e.g., daily peaking vs. baseload operation), changes in dam capacity, and environmental policies shifting the relative importance of periodicities over time. Our analysis demonstrates the pervasiveness of human signatures now characterizing the U.S. rivers' flow regimes, and may inform the restoration of environmental periodicity downstream of reservoirs via controlled flow releases—a critical need in light of new damming and dam retrofitting for hydropower globally. DA - 2023/2// PY - 2023/2// DO - 10.1029/2022EF003078 UR - https://doi.org/10.1029/2022EF003078 ER - TY - JOUR TI - Comprehensive analysis of the NOAA National Water Model: A call for heterogeneous formulations and diagnostic model selection AU - Johnson, J. Michael AU - Fang, Shiqi AU - Sankarasubramanian, Arumugam AU - Rad, Arash Modaresi AU - Cunha, Luciana Kindl AU - Clarke, Keith C AU - Mazrooei, Amirhossein AU - Yeghiazarian, Lilit AB - With an increasing number of continental-scale hydrologic models, the ability to evaluate performance is key to understanding uncertainty in prediction and making improvements to the model(s). In 2016, the NOAA National Water Model (NWM) was put into operations to improve the spatial and temporal resolution of hydrologic prediction in the U.S. Here, we evaluate the NWM 2.0 historical streamflow record in natural and controlled basins using the Nash Sutcliffe Efficiency metric decomposed into relative error, conditional, and unconditional bias. Each of these is evaluated in the contexts of categorized meteorologic, landscape, and anthropogenic characteristics to assess model performance and diagnose error types. Broadly speaking greater rainfall and snow coverage leads to improved performance while larger potential evapotranspiration (PET), aridity, and phase correlation reduce performance. More rainfall and phase correlation reduce overall bias, while increasing PET, aridity, snow coverage/fraction increase model bias. With respect to landscape traits, more barren and agricultural land yeild improved performance while more forest, shrubland, grassland and imperviousness tend to decrease performance. Lastly, more barren and herbaceous land tend to decrease bias, while greater imperviousness, urban, forest, and shrubland cover increase bias. The insights gained can help identify key hydrological factors in NWM predictions; enforce the need for regionalized physics and modeling; and help develop hybid post-processing methods to improve prediction. Finally, we demonstrate how the NOAA Next Generation Water Resource Modeling Framework can help reduce the structural bias through the application of heterogenous model processes and highlight opportunities for ongoing development and evaluation. DA - 2023/1/19/ PY - 2023/1/19/ DO - 10.22541/essoar.167415214.45806648/v1 UR - https://doi.org/10.22541/essoar.167415214.45806648/v1 ER - TY - JOUR TI - Contrasting Annual and Summer Phosphorus Export Using a Hybrid Bayesian Watershed Model AU - Karimi, K. AU - Miller, J. W. AU - Sankarasubramanian, A. AU - Obenour, D. R. T2 - Water Resources Research AB - Abstract Nutrient pollution is a widespread environmental problem that degrades water quality worldwide. Addressing this issue calls for characterizing nutrient sources and retention rates, especially in seasons when water quality problems are most severe. Hybrid (statistical‐mechanistic) watershed models have been used to quantify nutrient loading from various source categories. However, these models are generally developed for long‐term average conditions, limiting their ability to assess temporal drivers of nutrient loading. They also have not been calibrated for season‐specific estimates of loading and retention rates. To address these issues, we developed a hybrid watershed model that incorporates interannual variability in land use and precipitation as temporal drivers of phosphorus loading and transport. We calibrate the hybrid watershed model within a Bayesian hierarchical framework on both an annual and summer basis over a multi‐decadal period (1982–2017). For our study area in the North Carolina Piedmont region (USA), we find that urban lands developed before 1980 are the largest contributor of phosphorus (per unit area), especially under dry conditions. Seasonally, summer phosphorus export rates are generally found to be lower than corresponding annual rates (kg/ha/mo), while in‐stream retention is found to be elevated in summer. In addition, we find that precipitation has a substantially larger influence on phosphorus export from agricultural lands than other source types, especially in summer, and that antecedent (May) precipitation significantly influences summer phosphorus export. Overall, our approach provides a data‐driven and probabilistic line of evidence to support watershed phosphorus management across different sources and seasons. DA - 2023/1// PY - 2023/1// DO - 10.1029/2022WR033088 UR - https://doi.org/10.1029/2022WR033088 ER - TY - JOUR TI - Machine learning for sustainable development and applications of biomass and biomass-derived carbonaceous materials in water and agricultural systems: A review AU - Wang, Hannah Szu-Han AU - Yao, Yuan T2 - Resources, Conservation and Recycling AB - Biomass-derived materials (BDM) have broad applications in water and agricultural systems. As an emerging tool, Machine learning (ML) has been applied to BDM systems to address material, process, and supply chain design challenges. This paper reviewed 53 papers published since 2008 to understand the capabilities, current limitations, and future potentials of ML in supporting sustainable development and applications of BDM. Previous ML applications were classified into three categories based on their objectives – material and process design, end-use performance prediction, and sustainability assessment. These ML applications focus on identifying critical factors for optimizing BDM systems, predicting material features and performances, reverse engineering, and addressing data challenges for sustainability assessments. BDM datasets show large variations, and ∼75% of them possess < 600 data points. Ensemble models and state-of-the-art neural networks (NNs) perform and generalize well on such datasets. Limitations for scaling up ML for BDM systems lie in the low interpretability of the ensemble and NN models and the lack of studies in sustainability assessment that consider geo-temporal dynamics. A workflow is recommended for future ML studies for BDM systems. More research is needed to explore ML applications for sustainable development, assessment, and optimization of BDM systems. DA - 2023/3// PY - 2023/3// DO - 10.1016/j.resconrec.2022.106847 UR - https://doi.org/10.1016/j.resconrec.2022.106847 ER - TY - JOUR TI - Pareto Optimal and Dual-Objective Geometric and Structural Design of an Underwater Kite for Closed-Loop Flight Performance AU - Naik, Kartik AU - Beknalkar, Sumedh AU - Reed, James AU - Mazzoleni, Andre AU - Fathy, Hosam AU - Vermillion, Chris T2 - JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME AB - Abstract This paper presents the formulation and results for a control-aware optimization of the combined geometric and structural design of an energy-harvesting underwater kite. Because kite-based energy-harvesting systems, both airborne and underwater, possess strong coupling between closed-loop flight control, geometric design, and structural design, consideration of all three facets of the design within a single codesign framework is highly desirable. However, while prior literature has addressed one or two attributes of the design at a time, this work constitutes the first comprehensive effort aimed at addressing all three. In particular, focusing on the goals of power maximization and mass minimization, we present a codesign formulation that fuses a geometric optimization tool, structural optimization tool, and closed-loop flight efficiency map. The resulting integrated codesign tool is used to address two mathematical optimization formulations that exhibit subtle differences: a Pareto optimal formulation and a dual-objective formulation that focuses on a weighted power-to-mass ratio as the techno-economic metric of merit. Based on the resulting geometric and structural designs, using a mediumfidelity closed-loop simulation tool, the proposed formulation is shown to achieve more than three times the powerto-mass ratio of a previously published, unoptimized benchmark design. DA - 2023/1/1/ PY - 2023/1/1/ DO - 10.1115/1.4055978 VL - 145 IS - 1 SP - SN - 1528-9028 ER - TY - JOUR TI - ZVS Boundary Analysis and Design Guideline of MV Grid-Compliant Solid-State Transformer for DC Fast Charger Applications AU - Prabowo, Yos AU - Sharma, Shrivatsal AU - Bhattacharya, Subhashish AU - Tripathi, Awneesh Kumar AU - Bhavaraju, Vijay T2 - IEEE TRANSACTIONS ON TRANSPORTATION ELECTRIFICATION AB - A solid-state transformer comprising a cascaded H-bridge and a dual-active bridge converter is a promising solution for a megawatt medium voltage DC fast charger application. The new IEEE Std 1547.9-2022 comprehensively discusses extending the minimum reactive power capability to electric vehicle chargers. This paper analyzes the impact of operating the grid compliant single-phase solid-state transformer on the overall system. The impact of the DC-link voltage due to the single-phase implementation of the H-bridges on the dual-active bridge converter zero-voltage switching mode at light-load operation is highlighted. The system’s operational boundary is analyzed, which defines the reactive power capability limit while ensuring the dual-active bridge converter zero-voltage switching mode operation for the defined operating points. This zero-voltage switching mode boundary analysis is then used to develop a design guideline as part of the solid-state transformer design process. The proposed guideline allows a simultaneous design of a DC-link capacitor and dual active bridge inductance to ensure zero-voltage switching mode for the defined operating points. It leads to DC-link capacitance reduction that offers cost-and footprint-savings. The proposed concept is validated through simulations and experimental results. Further, a potential benefit analysis is provided to emphasize the effectiveness of the proposed concept. A supplementary video is included to showcase the system’s dynamic active and reactive power operation. DA - 2023/12// PY - 2023/12// DO - 10.1109/TTE.2022.3229223 VL - 9 IS - 4 SP - 4964-4980 SN - 2332-7782 UR - https://doi.org/10.1109/TTE.2022.3229223 KW - Cascaded H-bridge (CHB) KW - dc fast charger (DCFC) KW - dc-link capacitance KW - double-line frequency component KW - dual active bridge (DAB) KW - IEEE Std 1547 KW - light load operation KW - reactive power capability KW - single-phase solid-state transformer (SST) KW - zero-voltage switching (ZVS) ER - TY - JOUR TI - CexZr1–xO2-Supported CrOx Catalysts for CO2-Assisted Oxidative Dehydrogenation of Propane─Probing the Active Sites and Strategies for Enhanced Stability AU - Dou, Jian AU - Funderburg, Joey AU - Yang, Kunran AU - Liu, Junchen AU - Chacko, Dennis AU - Zhang, Kui AU - Harvey, Adam P. AU - Haribal, Vasudev P. AU - Zhou, S. James. AU - Li, Fanxing T2 - ACS Catalysis AB - CO2-assisted oxidative dehydrogenation of propane (CO2-ODH) represents an attractive approach for propylene production and CO2 utilization. As a soft oxidant, CO2 can minimize overoxidation of the hydrocarbons to enhance the propylene selectivity while increasing the equilibrium yield. However, a major challenge of CO2-ODH is the rapid deactivation of the catalysts. The current study focuses on designing CexZr1–xO2-mixed oxide-supported CrOx catalysts for CO2-ODH with enhanced product selectivity and catalyst stability. By doping 0–30% Ce in the CexZr1–xO2 mixed oxide support, propane conversion of 53–79% was achieved at 600 °C, with propylene selectivity up to 82%. Compared to the pure ZrO2-supported catalyst (i.e., 5 wt %Cr/ZrO2), 20–30 %Ce doped catalysts (i.e., 5 wt %Cr/Ce0.2Zr0.8O2 and 5 wt %Cr/Ce0.3Zr0.7O2) inhibited the formation of CH4 and ethylene and improved propylene selectivity from 57 to 77–82%. Detailed characterizations of the 5%Cr/Ce0.2Zr0.8O2 catalyst and density functional theory (DFT) calculations indicated that Cr3+ is the active species during the CO2-ODH reaction, and the reaction follows a non-redox dehydrogenation pathway. Coke formation was determined to be the primary reason for catalyst deactivation, and the addition of Ce to the ZrO2 support greatly enhanced the coke resistance, leading to superior stability. Coke removal by oxidizing the catalyst in air is effective in restoring its activity. DA - 2023/1/6/ PY - 2023/1/6/ DO - 10.1021/acscatal.2c05286 UR - https://doi.org/10.1021/acscatal.2c05286 KW - oxidative dehydrogenation KW - CO 2 conversion KW - stability enhancement KW - propylene KW - dehydrogenation ER - TY - JOUR TI - Mixed oxides as multi-functional reaction media for chemical looping catalysis AU - Liu, Junchen AU - Li, Fanxing T2 - Chemical Communications AB - Over the past two decades, chemical looping combustion (CLC) has been extensively investigated as a promising means to produce electric power while generating a concentrated carbon dioxide stream for sequestration. We note that the chemical looping strategy can be extended well outside of combustion-based carbon capture. In fact, application of the chemical looping strategy in areas beyond combustion can result in somewhat unexpected energy and carbon dioxide savings without producing a concentrated CO2 stream at all. Furthermore, it allows the looping-based technologies to tap into applications such as chemical production - a $4 trillion per year industrial sector with high energy and carbon intensities. The key resides in the design of effective oxygen carriers, also known as redox catalysts in the context of selective chemical conversion through chemical looping catalysis (CLCa). This contribution focuses on the design and applications of mixed oxides as multi-function reaction media in CLCa. Since typical mixed oxide oxygen carriers tend to be nonselective for hydrocarbon conversion, the first part of this article presents generalized design principles for surface modification of mixed oxides to improve their selectivity and catalytic activity. Applications of these redox catalysts in chemical looping - oxidative dehydrogenation (CL-ODH) of a variety of light alkanes and alkyl-benzenes are presented. This is followed with a discussion of computation assisted mixed oxide design based upon thermodynamic criteria. Finally, a few new directions for the chemical looping technologies are introduced. DA - 2023/// PY - 2023/// DO - 10.1039/D2CC05502C UR - https://doi.org/10.1039/D2CC05502C ER - TY - JOUR TI - Emerging Engineered Wood for Building Applications AU - Ding, Yu AU - Pang, Zhenqian AU - Lan, Kai AU - Yao, Yuan AU - Panzarasa, Guido AU - Xu, Lin AU - Ricco, Marco Lo AU - Rammer, Douglas R. AU - Zhu, J. Y. AU - Hu, Ming AU - Pan, Xuejun AU - Li, Teng AU - Burgert, Ingo AU - Hu, Liangbing T2 - Chemical Reviews AB - The building sector, including building operations and materials, was responsible for the emission of ∼11.9 gigatons of global energy-related CO2 in 2020, accounting for 37% of the total CO2 emissions, the largest share among different sectors. Lowering the carbon footprint of buildings requires the development of carbon-storage materials as well as novel designs that could enable multifunctional components to achieve widespread applications. Wood is one of the most abundant biomaterials on Earth and has been used for construction historically. Recent research breakthroughs on advanced engineered wood products epitomize this material's tremendous yet largely untapped potential for addressing global sustainability challenges. In this review, we explore recent developments in chemically modified wood that will produce a new generation of engineered wood products for building applications. Traditionally, engineered wood products have primarily had a structural purpose, but this review broadens the classification to encompass more aspects of building performance. We begin by providing multiscale design principles of wood products from a computational point of view, followed by discussion of the chemical modifications and structural engineering methods used to modify wood in terms of its mechanical, thermal, optical, and energy-related performance. Additionally, we explore life cycle assessment and techno-economic analysis tools for guiding future research toward environmentally friendly and economically feasible directions for engineered wood products. Finally, this review highlights the current challenges and perspectives on future directions in this research field. By leveraging these new wood-based technologies and analysis tools for the fabrication of carbon-storage materials, it is possible to design sustainable and carbon-negative buildings, which could have a significant impact on mitigating climate change. DA - 2023/3/8/ PY - 2023/3/8/ DO - 10.1021/acs.chemrev.2c00450 UR - https://doi.org/10.1021/acs.chemrev.2c00450 ER - TY - JOUR TI - Hierarchical frequency and voltage control using prioritized utilization of inverter based resources AU - Chakraborty, Rahul AU - Chakrabortty, Aranya AU - Farantatos, Evangelos AU - Patel, Mahendra AU - Hooshyar, Hossein AU - Darvishi, Atena T2 - INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS AB - We propose a novel hierarchical frequency and voltage control design for multi-area power system integrated with inverter-based resources (IBRs). The design is based on the idea of prioritizing the use of IBRs over conventional generator-based control in compensating for sudden and unpredicted changes in loads and generations, and thereby mitigate any undesired dynamics in the frequency or the voltage by exploiting their fast actuation time constants. A new sequential optimization problem, referred to as Area Prioritized Power Flow (APPF), is formulated to model this prioritization. It is shown that compared to conventional power flow APPF not only leads to a fairer balance between the dispatch of active and reactive power from the IBRs and the synchronous generators, but also limits the impact of any contingency from spreading out beyond its respective control area, thereby guaranteeing a better collective dynamic performance of the grid. This improvement, however, comes at the cost of adding an extra layer of communication needed for executing APPF in a hierarchical way. Results are validated using simulations of a 9-machine, 6-IBR, 33-bus, 3-area power system model, illustrating how APPF can mitigate a disturbance faster and more efficiently by prioritizing the use of local area-resources. DA - 2023/1// PY - 2023/1// DO - 10.1016/j.ijepes.2022.108527 VL - 144 SP - SN - 1879-3517 KW - Hierarchical control KW - Frequency control KW - Voltage control KW - Renewable energy KW - Inverter-based resources ER - TY - JOUR TI - An integrated techno-economic and environmental assessment for carbon capture in hydrogen production by biomass gasification AU - Wu, Na AU - Lan, Kai AU - Yao, Yuan T2 - Resources, Conservation and Recycling AB - Bioenergy with carbon capture and storage (BECCS) is a potential solution addressing climate change andregional wildfires, and supporting circular economy. This study investigates the economic and environmental performance of a BECCS pathway implementing carbon capture (CC) in hydrogen production via gasifying forest residues in the American West, by developing a framework that integrates process simulations, techno-economic analysis (TEA), and life cycle assessment (LCA). The results show that forest residue-derived hydrogen is economically competitive ($1.52– 2.92/kg H2) compared with fossil-based hydrogen. Incorporating CC increases environmental impact due to additional energy and chemical consumption, which can be mitigated by the energy self-sufficiency design that reduces CC cost to $75/tonne of CO₂ for a 2,000 dry short ton/day plant, or by using renewable energy such as solar and wind. Compared to electrolysis and fossil-based routes with CC, only BECCS can provide carbon-negative hydrogen and is more favorable regarding human health impact and near-term economics. DA - 2023/1// PY - 2023/1// DO - 10.1016/j.resconrec.2022.106693 UR - https://doi.org/10.1016/j.resconrec.2022.106693 KW - Carbon capture KW - Hydrogen KW - Biomass gasification KW - Techno-economic analysis KW - Life cycle assessment KW - BECCS ER - TY - JOUR TI - An Optimized Nonlinear Droop Control Method Using Load Profile for DC Microgrids AU - Sharma, Shrivatsal AU - Iyer, Vishnu Mahadeva AU - Bhattacharya, Subhashish T2 - IEEE Journal of Emerging and Selected Topics in Industrial Electronics AB - Paralleling of power electronic converters to achieve current sharing is a critical aspect of a dc microgrid. Droop control is a popular technique to parallel converters. This article presents a novel perspective of different practically realizable nonlinear droop characteristics. Using the probability distribution function of the load current, a methodology is proposed to optimize the characteristics of nonlinear droop control. In a stand-alone dc microgrid system, the load current information used in the proposed control method is typically known using historical data or can be estimated using load forecasting methods. The advantages of the proposed nonlinear droop control method over several state-of-the art nonlinear droop control methods are discussed and shown. The effectiveness of the proposed nonlinear droop control method is validated using circuit simulations and hardware-based experiments on a multiconverter system for different load profiles. DA - 2023/1// PY - 2023/1// DO - 10.1109/JESTIE.2022.3208513 UR - https://doi.org/10.1109/JESTIE.2022.3208513 ER - TY - JOUR TI - Spinel oxides as coke-resistant supports for NiO-based oxygen carriers in chemical looping combustion of methane AU - Mishra, Amit AU - Dudek, Ryan AU - Gaffney, Anne AU - Ding, Dong AU - Li, Fanxing T2 - CATALYSIS TODAY AB - Due to their high activity for methane conversion under a cyclic redox scheme, supported nickel oxides are among the most extensively investigated oxygen carrier materials for chemical looping combustion (CLC) and reforming (CLR) of methane. However, coke formation remains as a key challenge for Ni-containing oxygen carriers. The current study investigates the effect of reducible, spinel-structured supports to enhance coke resistance of NiO-based oxygen carriers. It was hypothesized that reducible supports capable of continued yet slow lattice oxygen donation in the presence of methane can actively retard coke formation on the surface of the oxygen carriers. To evaluate such effects, NiFe2O4, MgFe2O4, and BaFe2O4 are investigated as coke-resistant, reducible supports for NiO using mass spectrometry (MS) and thermogravimetric analysis (TGA) during chemical looping cycles. All three reducible supports were capable of continuous oxygen donation over an extended period of time (>40 min) without signs of coke formation. When used as supports for NiO, the resulting oxygen carriers showed no sign of carbon deposition under typical methane CLC environments. In comparison, NiO supported on inert MgAl2O4 exhibited significant coke formation after only 2.5 min. Moreover, NiO supported on NiFe2O4 and BaFe2O4 exhibited faster redox activity and higher oxygen carrying capacity when compared to the inert MgAl2O4-supported NiO. Detailed investigation of the reduction behavior of NiFe2O4-supported NiO revealed extensive solid-state reactions and Ni/Fe exchanges among the support, NiO, and newly formed phases. Specifically, initial weight loss in NiFe2O4-supported NiO was associated with reduction of the oxygen carrier to metallic Ni and Fe3O4 phases. Subsequent coke inhibition was attributed to the slow reduction of Fe3O4 and FeO phases. Multi-cyclic redox studies indicated that NiFe2O4-supported NiO gradually lost its redox activity. In comparison, both MgFe2O4- and BaFe2O4-supported NiO exhibited satisfactory redox stability, activity, and coke resistance. DA - 2023/12/1/ PY - 2023/12/1/ DO - 10.1016/j.cattod.2019.09.010 VL - 424 SP - SN - 1873-4308 UR - https://doi.org/10.1016/j.cattod.2019.09.010 KW - Chemical looping KW - Coke inhibition KW - Methane KW - Nickel oxide KW - Spinel oxides KW - Carbon capture ER -