Search Results (7,719)

Accurate and fast junction-temperature estimation in Silicon Carbide (SiC) power modules is crucial for reliable operation, health monitoring and predictive control of power electronic converters in different applications. However, direct temperature measurement inside the module is difficult and high-fidelity thermal models are often very computationally expensive for real-time implementation. This paper proposes a digital twin development approach for fast and accurate temperature estimation in all three dimensions of a SiC MOSFET power module by a combination of finite element method (FEM) modelling and neural networks. The work is especially relevant in thermal monitoring and managing power electronics converters such as renewable energy systems, energy storage systems, Electric Vehicles (EV), etc. The model incorporates a neural network trained on data generated from an FEM model built in COMSOL Multiphysics. The developed digital twin can estimate the temperature distribution, including the ten junction temperatures of the Wolfspeed EAB450M12XM3 module, with an average estimation time of 0.063 s, enabling predictive control. In order to improve practical applicability and model synchronization with the physical system, NTC-based feedback techniques are discussed (single-Temperature Coefficient (NTC) and double-NTC approaches). The proposed framework is investigated in terms of prediction accuracy and computational performance related to the FEM-generated reference data. The approach improves model reliability by adjusting the parameters of the critical digital and physical modules. The combination of FEM-based modelling and machine learning can provide a foundation for accurate, real-time thermal monitoring in power electronic modules. Full article

In this study, we dissect the genetic effects of two major rice heading date genes, Heading date 1 (Hd1) and Grain number, plant height, and heading date 7 (Ghd7), in the regulation of six photosynthesis-related traits: the chlorophyll a/b contents, net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO₂ concentration (Ci), and transpiration rate (Tr). Using two sets of near-isogenic lines (Z43 and Z44) derived from a Zhenshan97/Milyang46 cross, functional Hd1 increased the chlorophyll contents but decreased the photosynthesis-related parameters; however, functional Ghd7 consistently inhibited all six traits. More importantly, there is a significant epistatic interaction between them: Hd1 only enhances the photosynthetic capacity under the non-functional background of ghd7 but intensifies its photosynthesis inhibition under the functional background of Ghd7. Transcriptome analysis showed that functional Ghd7 mainly down-regulated the expression of genes related to photosynthesis and chloroplast development, and the inhibitory effect was significantly enhanced in the presence of functional Hd1. GO enrichment analysis further confirmed that the chlorophyll synthesis, photosystem assembly, and electron transfer pathways were downregulated in the bifunctional allele combination. Although Hd1 promotes chlorophyll accumulation, it reduces the actual photosynthetic efficiency, indicating that it has different regulatory paths for chlorophyll synthesis and photosynthetic function. Both physiological and molecular evidence showed that the Hd1-Ghd7 module coordinated the regulation of the heading date and photosynthetic capacity, forming a trade-off relationship between “early heading–high photosynthesis” and “late heading–low photosynthesis”. This study reveals the pleiotropy of genes at the heading stage and provides a theoretical basis for the optimization of the source–sink balance in high-yield rice breeding. Full article

Wireless power transfer (WPT) systems have garnered significant market attention owing to their broad applicability in portable electronic devices, electric vehicles, unmanned aerial vehicles, biomedical implants, and related fields. In these systems, operating frequency and efficiency are critical factors affecting both transmission efficiency and transmission distance, making high-frequency operation an important trend for improving overall WPT performance. However, elevating the switching frequency also introduces notable challenges, including increased switching losses in power devices, limited load adaptability, and poor anti-misalignment capability, which in practice often lead to degraded system efficiency and unsatisfactory waveform quality. Accordingly, this paper proposes a high-frequency inverter power supply system capable of operating at a maximum output voltage frequency of 25 KHz. Under conditions of a 10 KHz output frequency and a 20 KΩ load, the system achieves a peak efficiency of 94.01%. A prototype was implemented through the integration of a software algorithm based on ARM Cortex-M3 core control with a hardware architecture consisting of a driving circuit, a full-bridge inverter, and a switchable filtering module. This work offers practical design insights for the development of future high-frequency, high-voltage inverter systems, while also providing valuable experimental data to support further research in this area. Full article

CaCO₃/BiO_2−x/CdS (CCO/BO/CS) ternary composite photocatalyst was synthesized via a hydrothermal method combined with chemical precipitation, and its performance in the photocatalytic reduction of hexavalent chromium (Cr(VI)) under visible light was systematically investigated. Compared with pure BiO_2−x, CdS, and binary BiO_2−x/CdS composites, the CCO/BO/CS system exhibited significantly enhanced Cr(VI) reduction activity. Specifically, the CCO/BO/CS (0.75:1:2 wt) composite achieved a Cr(VI) reduction efficiency of 94.53% within 30 min of visible light irradiation—approximately 94.6 times and 6.1 times higher than those of BiO_2−x (1.0%) and CdS (15.52%). Photoelectrochemical and trapping experiments revealed that the enhanced performance stems from improved charge separation, accelerated interfacial electron transfer, and the promotional role of CaCO₃—likely through lattice distortion—rather than direct photocatalytic participation. This study highlights the innovation of incorporating low-cost, eco-friendly calcium carbonate into semiconductor-based photocatalysts to induce lattice distortion for enhanced charge separation, as an effective strategy for improving the reduction efficiency of Cr(VI). Full article

Hydrogen-mediated microbial electrosynthesis (MES) of chemicals from CO₂ relies on effective gas–liquid transfer at the cathode interface, yet the extent to which cathode surface area regulates acetate productivity remains insufficiently quantified. In this study, three identical MES reactors equipped with stainless-steel cathodes of different geometric areas (8 × 1, 8 × 4, and 8 × 16 cm²) were operated at a constant electric current of 0.3 A. The largest cathode significantly accelerated hydrogen mass transfer (k_La = 0.592 h⁻¹), reaching dissolution equilibrium within 3 min, which was nearly twice as fast as the smallest electrode. Upon inoculation with enriched acetate-producing microbial consortia, the 8 × 16 cm²_cathode reactor fed with CO₂ achieved the highest steady-state acetate concentration of 32 g·L⁻¹ produced at a rate of 2.12 g·L⁻¹·d⁻¹, with 94% hydrogen utilization, and 59% coulombic efficiency. In contrast, smaller electrodes exhibited rapid bubble detachment and reduced residence time, thereby limiting microbial gas uptake, and resulting in low acetate productivity. These findings demonstrate that cathode surface area is a key engineering lever controlling both hydrogen availability and electron recovery efficiency in H₂-driven MES. The results provide practical guidance for electrode design and scale-up of CO₂-to-acetate bioconversion via the MES process. Full article

Calculation of heat transfer in granular materials is an important task for many applications, from thermal management in electronics to exploring celestial soils. Usually, an effective thermal-conductivity model is employed to predict heat flux in unstructured granular media, such as a packed bed. However, a more advanced approach, the discrete element method (DEM), can capture the complex effects of mechanical loading and material mixtures on thermal transport coefficients, which traditional models struggle with. Pivotal for this approach is knowing the heat transfer coefficient between two adjacent particles. Currently, in most DEM-capable software, only particles in direct surface contact are considered to have non-zero heat conduction. We propose considering particles that are close to each other but don’t have a contact area with a non-zero surface area. We perform numerical modeling of the conductive heat transfer coefficient between equal spherical particles separated by media, assuming the fluid’s thermal conductivity is at least an order of magnitude lower. We use numerical solutions of differential equations to account for both thermal resistance within particles and through the gap between them. We found a simple generalized correlation for the heat transfer coefficient between particles and a general formula for the angular distribution of heat flux density across the particle surface. By employing a non-dimensional approach, the obtained formulas are constructed using non-dimensional parameters: the ratio of the particle’s thermal conductivity to that of the medium, and the ratio of the gap width between particles to their radius. The resulting formula is simple and convenient for DEM heat transfer calculations in packed and fluidized beds. Full article

This study addresses the challenges associated with deep-well drilling mud cuttings, including large waste volumes, high transportation costs, and complex organic pollutants. A low-cost synergistic technology was developed for the resource utilization of pyrolyzed drilling waste residue (PDWR) and the in situ remediation of oil-contaminated drill cuttings. A ternary photocatalytic system consisting of PDWR, H₂O₂, and oxalic acid was proposed and demonstrated to effectively degrade total petroleum hydrocarbons (TPH) in drill cuttings under solar irradiation. Systematic optimization identified optimal dosages of PDWR, H₂O₂, and oxalic acid as 250 mg, 280 mg, and 90 mg, respectively. The addition of oxalic acid significantly enhanced photocatalytic oxidation performance, increasing H₂O₂ utilization by 63.8% and improving the TPH degradation rate by a factor of 3.03. Under optimal conditions and 7 days of solar irradiation, TPH degradation efficiencies of 65.19–88.66% were achieved for initial TPH concentrations ranging from 5000 to 12,000 mg kg⁻¹. Mechanistic analysis revealed that a Fenton-like reaction between transition metals in PDWR and H₂O₂ dominated the photocatalytic process, while oxalic acid facilitated metal redox cycling through coordination and electron transfer, promoting sustained generation of reactive oxygen species (·OH). This study demonstrates a feasible and sustainable approach for high-value utilization of drilling waste residue and solar-driven in situ remediation of oil-contaminated drill cuttings, highlighting its strong potential for practical application. Full article

L-glutamate (L-Glu) is the primary excitatory neurotransmitter in the mammalian central nervous system. Developing a real-time monitoring system is essential to understanding the onset and progression of related conditions. However, the absence of an L-Glu dehydrogenase that is insensitive to oxygen limits the development of oxygen-independent electrochemical enzymatic sensors. Additionally, the most commonly used L-Glu-specific oxidase requires site-specific proteolytic post-translational modifications in specific host microorganisms, which makes protein engineering difficult. To address these issues, L-Glu oxidase derived from Streptomyces mobaraensis (SmEOx), which does not require post-translational modifications, was engineered to function as a dehydrogenase. Residues crucial for the oxidative half reaction with oxygen in SmEOx were identified, and mutagenesis studies were conducted. Mutant SmEOx variants with suppressed oxidase activity and improved dye-mediated dehydrogenase activity compared to the wild-type enzyme were successfully obtained. The ratio of dehydrogenase activity to oxidase activity (Dh/Ox) increased ~2900-fold in mutant M117I and ~6700-fold in mutant M117F/K400N compared to wild-type recombinant SmEOx. The resulting virtually L-Glu dehydrogenases (vEDHs) were modified with a redox mediator and evaluated using transient open-circuit potential (OCP)-based L-Glu measurements. As a result, the vEDH (M117F/K400N mutant)-immobilized electrode enabled electrochemical L-Glu detection under ambient oxygen without the need for an external electron mediator, unlike the wild-type enzyme. The created vEDH, together with the OCP sensor developed using it, paves the way for future development of miniaturized, real-time L-Glu monitoring systems with high temporal and spatial resolution. Full article

Photocatalytic CO₂ reduction to high-value-added C₂+ products is a practical route from an economic viewpoint for advancing the industrialization of CO₂ conversion. Despite significant progress in catalyst modification in recent years (such as defect engineering, heterostructure construction, and single-atom modification), the generation of C₂+ products still faces challenges due to the slow kinetics of multi-electron reactions and the high thermodynamic barrier for C-C coupling. Moreover, the severely imbalanced molar ratio of CO₂ to H₂O in the traditional liquid-phase reaction systems exacerbated the challenge to the unfavorable situation. This article summarizes various strategies to improve the yield of C₂+ products through the regulation of reaction environments, including: (1) increasing the partial pressure of CO₂ to enhance its solubility; (2) using alternative solvents like ionic liquids to reduce water content; (3) transitioning the reaction system from liquid phase to gas phase; (4) designing a three-phase (gas–liquid–solid) interface or floating photocatalysts to optimize reactant transfer and local concentration; (5) utilizing photothermal synergistic effects to enhance the reaction temperature and efficiency under concentrated light. It also discusses the role of different reactor designs in improving the reaction environment. Finally, it emphasizes that future research should pay more attention to the optimization of the reaction environment engineering in addition to catalyst design, providing new perspectives for achieving efficient and highly selective C₂+ products in CO₂ photoreduction. Full article

Ochratoxin A (OTA) is a highly toxic mycotoxin commonly detected in food and agricultural products, requiring sensitive analytical methods for reliable monitoring. Herein, we report an ultrasensitive turn-on electrochemical aptasensor for OTA detection based on a target-induced displacement of an aptamer–complementary DNA (cDNA) duplex assembled on an electrochemically reduced graphene oxide (ERGO)-modified glassy carbon electrode (GCE). In the absence of OTA, a methylene blue (MB)-labeled aptamer hybridized with cDNA is immobilized on the ERGO surface via π–π stacking interactions, forming a rigid duplex that suppresses electron transfer and yields a low electrochemical signal. Upon OTA binding, the aptamer undergoes a conformational transition into a G-quadruplex structure, leading to dissociation of the cDNA strand. This target-induced folding brings the MB redox tag into close proximity to the ERGO surface, markedly accelerating electron transfer and enhancing the cathodic reduction current of MB, thereby producing a pronounced signal-on response in square-wave voltammetry (SWV). The ERGO-modified electrode provides a conductive and stable interface without chemical linkers. Under optimized conditions, the aptasensor shows a linear response to OTA from 10 fM to 100 pM with an ultralow LOD of 0.67 fM, together with high selectivity, good reproducibility, and satisfactory stability. This work demonstrates a simple and effective turn-on aptasensing strategy for sensitive electrochemical detection of OTA. Full article

This study evaluated the electrochemical and oxidative performance of titanium-supported RuO₂–SnO₂–Sb₂O₅ mixed metal oxide electrodes (hereafter denoted as RuO₂–SnO₂–Sb₂O₅/Ti) for degrading three aniline-based dyes and their mixture using electro-oxidation (EOx), electro-Fenton (EF), and photoelectron-Fenton (PEF) processes. Electrochemical characterization showed quasi-reversible redox behavior and fast electron-transfer kinetics, while SEM, AFM, and EDS analyses revealed a rough surface with fissures and agglomerates that increased the real electroactive area to 4.85 cm², supporting the high catalytic activity. Spectroscopic analyses confirmed the functional groups typical of azo dyes, and RNO assays verified sustained hydroxyl-radical production during electrolysis. Current density was the main operational factor: at 50 mA cm⁻², decolorization exceeded 90% due to enhanced ^•OH generation, whereas higher initial dye concentrations decreased reaction rates because of surface saturation and diffusion limitations. Among the oxidation processes, EF was most effective for Brown KK and Brown 5VR, EOx performed best for Brown NT, and PEF showed a slight advantage for the dye mixture owing to UV-assisted regeneration of reactive species. COD removal followed similar trends, with Brown KK mineralizing fastest and Brown 5VR showing the highest recalcitrance. Analysis of H₂O₂ and active chlorine indicated that EOx favors the accumulation of chlorine-derived oxidants, whereas PEF maximizes H₂O₂ conversion to ^•OH and reduces chlorinated by-products, positioning PEF as the most efficient and environmentally favorable option for treating chloride-containing wastewater. Full article

Extracellular vesicles (EVs) are lipid-enclosed particles secreted from a wide variety of cells, with the ability to transfer biologically active content from parent to recipient cells. Lung epithelial-derived EVs (LE-EVs) play an important role in the progression of pulmonary disease, but there is limited evidence regarding the impact of cigarette smoke (CS) and electronic cigarette aerosol (ECA) on epithelial-derived EVs. The aim of this systematic review was to evaluate the current published literature on the impact of cigarette smoke and electronic cigarette aerosol on LE-EVs. Original research studies and clinical data were included, but research involving microparticles or non-epithelial-derived EVs was excluded. A total of 29 articles were identified from three databases (EMBASE, Web of Science and PubMed), of which nine demonstrated that CS exposure leads to molecular changes in epithelial-derived EVs, whereas 21 reported that CS-induced LE-EVs can deliver their cargo to neighbouring cells. The results highlighted that LE-EVs secreted in response to cigarette or e-cigarette exposure presented altered EV cargo, associated with increased cellular damage, inflammation and disease development. The current literature suggests that conventional and electronic cigarettes can influence the secretion of EVs from lung epithelial cells, with these EVs potentially playing a role in the development of lung inflammation. Nonetheless, there is limited research studying the impact of ECA on LE-EVS. Further research examining the impact of electronic cigarettes on lung epithelial-derived EVs, using robust human in vitro models coupled with clinical studies, is required. Full article

Boron is a chemically distinctive bioelement whose electron-deficient structure enables reversible coordination with oxygen-rich functional groups such as diols and hydroxyls. This property allows boron to modulate molecular stability, conformation, and biological reactivity, giving rise to both beneficial pharmacological effects and toxicological outcomes. This review examines the dual biological role of boron through the framework of bioactive boron-containing natural products and natural compounds capable of forming reversible boron complexes. Particular attention is given to naturally occurring boron-containing antibiotics, including the polyketide macrodiolides boromycin, aplasmomycin, tartrolons, and hyaboron, where boron plays a direct structural and functional role in antimicrobial activity. These compounds demonstrate how boron coordination can influence ion transport, membrane interactions, and molecular assembly, contributing to potent antibacterial properties. Beyond intrinsically boron-containing metabolites, many natural antibiotics and toxins possess oxygen-rich architectures capable of forming transient borate complexes through vicinal 1,2-diol motifs. Examples include polyene macrolide antibiotics such as amphotericin B, fungichromin, and nystatin, as well as tetracyclines, rifamycins, and macrolides such as sorangicin A, where boron coordination may affect solubility, aggregation, ionophoric behavior, and biological selectivity. Similar chemistry is observed in marine neurotoxins and polyether toxins—including tetrodotoxin, saxitoxin derivatives, azaspiracids, pectenotoxins, ciguatoxins, and gambierones—whose hydroxyl-rich frameworks enable reversible interactions with boron species present in seawater. Such complexation may enhance aqueous stability and contribute to trophic transfer and bioaccumulation within marine ecosystems. By framing boron as a molecular “double edge,” this review integrates chemical, biological, and environmental perspectives to highlight how boron coordination can simultaneously enhance antimicrobial activity while influencing toxicity and ecological persistence. Recognizing the role of boron in shaping the activity of natural products provides new insight into antibiotic function, toxin behavior, and the broader impact of boron chemistry in biological systems. Full article

The rapid growth of polyethylene terephthalate (PET) waste and the limitations of conventional recycling methods for mixed waste streams emphasize the need for chemical recycling routes that deliver high-value monomers in a sustainable, resource-efficient manner. This work explores N-heterocyclic carbenes (NHCs) as organocatalysts for the glycolysis of PET with ethylene glycol to bis(hydroxyethyl)terephthalate (BHET), aiming for milder conditions and higher activity. A systematic catalyst screening links steric and electronic properties (percent buried volume, Tolman electronic parameter) of the NHCs to performance in the glycolysis process, resulting in a catalyst system with high PET conversion (up to 97%) and BHET yield (up to 65%). Mechanistic investigations (experimental and computational) support an anionic activation pathway for glycolysis. To lower the reaction temperature, selective cosolvent systems were explored, albeit with some loss of catalytic activity. Cooperative catalysis combining NHCs with Lewis acids enhances activity, leading to a high conversion (up to 90%) while maintaining lower temperatures than state-of-the-art glycolysis methods. The process was successfully transferred to post-consumer waste streams to validate the practicality. Full article

The bioconversion of propionate, a well-known intermediate of anaerobic digestion (AD), to methane is energetically unfavorable under standard conditions, which typically occurs in the syntrophy of bacteria and methanogens via methylmalonyl-CoA (MMC) and the dismutation pathway. Since the latter, which is reported only in Smithella, possessed a thermodynamic advantage over the former, enriching Smithella and promoting the syntrophic interaction and metabolism of the microbiota are important for improving AD efficiency. In this study, lysine-modified Fe₃O₄ (Lys@Fe₃O₄) significantly enhanced the bioconversion of propionate to methane. The methane yield and the maximum methane production rate (R_max) in a Lys@Fe₃O₄ reactor were 278.7% and 271.7% of Blank, and the corresponding values were 201.9% and 201.6% of bare Fe₃O₄, respectively. The metaproteomic results indicated that Lys@Fe₃O₄ increased not only the abundance of Smithella but also the expression of cell surface and adhesion proteins, thereby promoting syntrophic interaction between Smithella and methanogens and facilitating electron and acetate transfer from Smithella to methanogens. Moreover, the expression of quorum-sensing proteins was enhanced, benefiting the cooperation of Smithella and its associated bacterium (Syntrophomonas). Furthermore, the expressions of key enzymes related to metabolism and electron transfer in propionate oxidation, butyrate oxidation, CO₂-reductive methanogenesis and acetoclastic methanogenesis were all significantly upregulated. The results are of great significance for maintaining low propionate concentration and stability of AD. Full article