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Power losses in semiconductor devices present a significant impediment to advancing power electronics systems for achieving higher frequencies, improved efficiency, and greater integration. A major challenge lies in directly coupling power losses with various control strategies, considering the variations in manufacturers, packaging, and process structures within the power electronics field. This paper introduces a field‐circuit coupling simulation methodology of the insulated gate bipolar transistor (IGBT) within the Simulink/COMSOL environment, using a conventional three‐phase six‐switch voltage source inverter (VSI) IGBT module as a case study. A composite transfer function interconnects the electrical and thermal aspects, enabling bidirectional coupling between IGBT temperature and losses. This study aims to comprehensively compare the effects of various control strategies, namely, single‐vector, dual‐vector, and three‐vector current model predictive control (CMPC) and space vector pulse width modulation (SVPWM), on the losses and temperature of IGBT power modules. The findings emphasize that losses are significantly influenced by the selection of weighting factor coefficients and power factor settings under the same CMPC control strategy with a fixed switching frequency. Additionally, the selection of control strategies, such as CMPC and SVPWM, substantially impacts power losses in power electronic devices. [ABSTRACT FROM AUTHOR]

Summary: This paper presents a multiobjective optimal power prediction fault‐tolerant control (MO2PPC) approach for mitigating DC link neutral‐point voltage imbalance and current ripple problems in three‐level T‐type inverter (3LT2I). Additionally, an auxiliary thyristor is employed to isolate and reconstruct the faulty phase into an 8ST2I for ensuring uninterrupted operation during phase failure. A method called injected bias current‐MO2PPC (IBC‐MO2PPC) fault‐tolerant strategy is proposed for this structure. This approach eliminates the need for DC or AC current sensors to reconstruct the three‐phase current, thereby reducing neutral‐point oscillation caused by phase deficiency and ensuring full power output after failure. Additionally, nonfaulty phase power loss is compared and analyzed to verify the stability of this method following a phase fault. The internal losses and temperature distribution of an IGBT module in a bridge arm before and after a fault are verified through a multiphysics‐circuit model in COMSOL‐Simulink coupling simulation presented last. The model shows reduced conduction losses and overall lower temperature distribution in the IGBT module after fault reconstruction. Experiments and multiphysics simulations have demonstrated that this approach displays exceptional robustness and sustainability throughout the entire fault cycle. [ABSTRACT FROM AUTHOR]

Herein, a one-step co-pyrolysis protocol was adopted for the first time to prepare a novel pyrogenic carbon-Cu0/Fe 3 O 4 heteroatoms (FCBC) in CO 2 ambiance to discern the roles of each component in PDS activation. During co-pyrolysis, CO 2 catalyzed formation of reducing gases by biomass which facilitated reductive transformation of Fe3+ and Cu2+ to Cu0 and Fe 3 O 4 , respectively. According to the analysis, the resulting metal (oxide) catalyzed graphitization of biocharand decomposition of volatile substances resulting in an unprecedented surface area (1240 m2/g). The resulting FCBC showed greater structural defects and less electrical impedance. Batch experiments indicated that Rhodamine B (RhB) degradation by FCBC (100%) was superior to Fe 3 O 4 (50%) and Cu0/Fe 3 O 4 (76.4%) in persulfate (PDS) system, which maintained reasonable efficiency (75.6%-63.6%) within three cycles. The reactive oxygen species (ROS) associated with RhB degradation was identified by an electron paramagnetic resonance and confirmed by scavenging experiments. RhB degradation invoked both (sulfate and dominantly hydroxyl) radical and non-radical (singlet oxygen, 1O 2) pathways. Regarding FCBC, Cu0 can continuously react with Fe3+ in Fe 3 O 4 to generate larger quantities of Fe2+, and both Cu0 and Fe2+ activated PDS to yield sulfate radicals which was quickly converted to hydroxyl radical. Besides, Cu0/Cu2+ could complex with PDS to form a metastable complex, which particularly contributed to 1O 2 generation. These cascade reactions by FCBC were reinforced by carbonyl group of biochar and favorable electron transfer ability. This work highlighted a new approach to prepare a magnetic and environment-benign heterogonous catalyst to remove organic pollutants in water. [Display omitted] [ABSTRACT FROM AUTHOR]

There is a need to prepare a high-efficient sorbent to remove the recalcitrant tetracycline (TC) in wastewater. Herein, biochar-supported zerovalent iron (BC/ZVI) was fabricated in nitrogen ambience via one-step co-pyrolysis of hematite and pinewood. X-ray diffractometer pattern indicated pinewood catalyzed conversion of hematite to ZVI, which was otherwise transformed to FeO, Fe3O4 and ZVI without biomass. Batch sorption results indicated that TC removal capacities at pH 5 were 8.02, 177.70 and 301.39 mg g−1 by BC, ZVI and BC/ZVI, respectively. Overall, BC/ZVI showed excellent TC removal capacity through the complexation with Fe ions, surface adsorption and degradation. Thus, the agricultural and industrial wastes were converted via a one-step co-pyrolysis to a value-added product for highly efficient removal of TC in wastewater. [ABSTRACT FROM AUTHOR]

Bilayer swelling behavior of cationic and anionic surfactant mixtures in solution induced by adding glycerin was investigated. The measurements were performed a system, cationic tetradecyltrimetylammonium bromide (TTABr), and anionic sodium perfluorodecanoate (C9F19CO2Na) surfactant mixtures with their stoichiometric mole ratio being exactly 1 in aqueous solution. The non-precipitated phase of cationic and anionic hydro- and perfluoro-carbon surfactant mixtures being the mole ratio of 1:1 could be identified to be lamellar gel phase, which was characterized by freeze-fracture transmission electron microscopy (FF-TEM) and x-ray diffraction (XRD) measurements. Deuterium nuclear magnetic resonance (2H NMR) and rheology were used to characterize the phase transition from the lamellar gel to smaller vesicles. Phase transition from lamellar gel to smaller vesicles can be induced by adding glycerin to replace water. The addition of glycerin lowers the turbidity of the dispersion and swells the interlamellar distance between bilayers, which could be explained by matching of refractive index between solvent and bilayers. [ABSTRACT FROM AUTHOR]

In this work, pinewood and bamboo were pyrolyzed at 600 °C to prepare PBC and BBC-supported zerovalent iron (ZVI), respectively. Raman spectra suggested PBC was more intensively carbonized than BBC as indicated by higher I D /I G ratio. XRD and TEM confirmed nanoscaled ZVI was well dispersed in PBC but soldered in chain-structure in BBC. Maximal chromate (Cr(VI)) sorption capacity followed the order of PBC/ZVI (5.93 g kg−1)>BBC/ZVI (3.61 g kg−1)>BBC (3.55 g kg−1)>PBC (2.59 g kg−1). Desorption and XPS of four Cr-spent sorbents suggested reduction accounted for 79–88% of overall Cr(VI) detoxification. Greater Cr(VI) reduction of BBC than PBC indicated greater tendency of BBC to donate electrons. However, Cr(VI) reduction by PBC/ZVI was 1.7 times greater than BBC/ZVI, corresponding to greater electron transfer of PBC/ZVI (2.5 μA e−) than BBC/ZVI (0.5 μA e−). Thus, PBC is more conducible to transfer electrons as evidenced by Tafel and Amperometric analyses. Demineralization of pristine BC enhanced the difference between PBC/ZVI and BBC/ZVI regarding Cr(VI) reduction, suggesting the dominant role of biopolymers in biomass in terms of electron transfer capacity. Three model biopolymers were compared which indicated lignin-BC had lower electron transfer rates than cellulose-BC and hemicellulose-BC. BC prepared by lignin extracted from pinewood exhibited higher corrosion rate and lower electrical resistance than that from bamboo. Thus, unfavorable lignin in bamboo compromised electron transfer of BBC and Cr(VI) reduction by BBC/ZVI. Image 1 [ABSTRACT FROM AUTHOR]

Abstract Siderite as a Fe(II)-bearing mineral often be naturally weathered and oxidized into goethite, which would decrease the surface chemical activity of the siderite. The chemical activity of siderite is improved by decomposing weathering-formed goethite at low temperature (350 °C). The activated natural siderite (ANS) was utilized to remove U(VI) from aqueous solutions. Batch experiments revealed that ANS after thermal treatment at 350 °C (ANS350) exhibited excellent uptake performance toward U(VI) (14.65 mg/g) which was better than natural siderite (9.00 mg/g) at pH = 4.0 and T = 293 K. Meanwhile, the uptake percents of U(VI) on NS and the uptake process was involved electrostatic attraction on the surface of adsorbents. The characterization results illustrated that activated natural siderite at 350 °C presented the better uptake capacity due to its larger specific surface area and smaller average pore size compared to natural siderite, which was optimized to adsorb U(VI) from aqueous solutions. The spectroscopic analysis demonstrated that the abundant surface oxygenated functional groups of ANS facilitated the uptake process of U(VI). Meanwhile, reduction was also involved in the process. Additionally, the U(VI) reduction amount can be enhanced to some extent after calcination. These findings give insight into the further development of activated natural mineral obtained by heating in low temperature, for using as potential candidate in immobilization of uranium(VI) from contamination water in actual environmental management. Highlights • Natural siderite was activated by thermal treatment at low temperature. • ANS350 exhibited excellent uptake performance toward U(VI) (14.65 mg/g). • Abundant oxygenated functional groups facilitated the uptake process of U(VI). • Reduction was involved the U(VI) uptake and calcination at low temperature could enhance the reduction amount. [ABSTRACT FROM AUTHOR]

Herein, the major biochar properties were correlated with electron transfer of zerovalent iron (ZVI) and contribution of biomass constituents to biochar property was ascertained to optimize electron transfer of ZVI. To this end, five respective stalk-type and wood-type lignocellulosic biomasses were pyrolzed at 600 °C to prepare biochars to harbor ZVI (ZVI/BC). Thermogravimetric analysis demonstrated woody biomasses decomposed more intensively at higher temperature relative to stalky biomass. ZVI/BC were characterized with Raman, X-ray diffraction, and electrochemical analyses including electron donating capacity (EDC) and electron accepting capacity (EAC). Pearson correlation and partial least-squares (PLS) analyses confirmed that Cr(VI) reduction capacity was negatively related to Tafel corrosion potential and intensity ratio of I D /I G , but significantly positively-related to EDC of BC, in which EDC was a predominant attribute to contribute to reductive capacity toward Cr(VI) reduction. That is, greater EDC and higher graphitic carbon structure of biochar due to cellulose and hemicellulose components favor electron transfer of ZVI toward Cr(VI) reduction. [Display omitted] • Woody biomass loses more weight than stalky biomass at higher temperatures. • Tafel corrosion potential and I D /I G were negatively related to Cr(VI) reduction. • BC's electron donating capacity (EDC) is positively-related to Cr(VI) reduction. • EDC is a main attribute that contributes to reductive capacity of ZVI/BC. • (Hemi)cellulose components favor electron transfer of ZVI toward Cr(VI) reduction. [ABSTRACT FROM AUTHOR]

Effects of sewage sludge-derived biochar and its precursor on the accumulation of metals (Cd, Cu, Pb and Zn) in soil and their uptake by plants in a 1-year field experiment involving corn-radish rotation were comparatively studied. The human health risks were assessed, and the safe application period of biochar were estimated. The application of biochar, compares to sewage sludge, significantly enhanced the radish yield (p < 0.05; not corn yield) and significantly reduced the accumulation of metals in both plants (p < 0.05), especially the annual application at ≤15 t ha−1. The hazard quotient analyses of the metals showed there were no health risks to humans (Hazard Index < 1) in consuming the edible parts of the both plants. The application of sewage sludge at ≥15 t ha−1 resulted in Cd in radish exceeded the threshold for foodstuffs set by China (0.1 mg kg−1). The total contents of Cd, Cu, Pb and Zn in soil increased gradually as the application of sewage sludge or its biochar increased from 7.5 t ha−1 to 30 t ha−1. More metals were found to be introduced to soil by the land application of biochar than by its precursor at the same doses, because the metals were concentrated in biochar during the preparation process. The contamination risk assessment of soil based on the geo-accumulation index, the contamination factor and the pollution load index suggested the application of biochar on farmland should <15 t ha−1. Therefore, taking into account the yield of and metal concentrations in the radish and corn plants and the contamination risks in soil, it is recommended that the continuous safe application period at an application of 7.5 t ha−1 year−1 of biochar should not exceed 15 years, and that of its precursor sewage sludge should not exceed 17 years. Unlabelled Image • The soil-plant-human health risks by application of sludge biochar were assessed. • The safety application years of sludge biochar in farmland were estimated. • Metals in radish and corn were lowered by application of biochar than sludge. • More metals were loaded into soil by application of biochar than sludge. • The max safety application years for biochar was 15 y at a dose of 7.5 t ha−1 y−1. [ABSTRACT FROM AUTHOR]

In current study, the UASB reactor was enhanced by nitrogen-doped sewage sludge based activated carbon supported Fe 3 O 4 (Fe 3 O 4 /N-SBAC) for coal gasification wastewater treatment. The results showed that COD removal efficiency was increased to 64.4% with Fe 3 O 4 /N-SBAC assistance and the corresponding methane production rate achieved up to 1093.6 mL/d. Fe 3 O 4 /N-SBAC promoted microbial growth and enzymatic activity, leading to high extracellular polymeric substances and coenzyme F 420 concentrations. Fe 3 O 4 /N-SBAC also facilitated the sludge granulation process with high particle size, substantial interspecific signal molecules and low diffusible signal factor. Microbial community analysis revealed that Fe 3 O 4 /N-SBAC might support direct interspecies electron transfer process, in which the enriched Geobacter was likely to communicate with Methanothrix via electrical connection, improving anaerobic degradation of coal gasification wastewater. Total phenols shock and pH impact revealed that reactor stability was enhanced in the Fe 3 O 4 /N-SBAC-supplemented system. Unlabelled Image • Fe 3 O 4 /N-SBAC improved pollutant removal and methane production rate. • Fe 3 O 4 /N-SBAC facilitated microbial accumulation and sludge granulation. • Enriched Geobacter might perform DIET with Methanothrix. • Reactor with Fe 3 O 4 /N-SBAC assistance could resist Tph shock and acidic impacts. [ABSTRACT FROM AUTHOR]