Search Results (1,772)

This paper proposes an Active Gate Driver (AGD) for a DC–DC boost converter based on Silicon Carbide (SiC) power devices, in which surge voltage and ringing arise from their fast-switching characteristics. In this work, a practical and simple 4-bit logic AGD was proposed to adjust the gate resistance during the Miller interval of the SiC MOSFET. This helps suppress these effects and lowers the surge voltage and ringing stress on the power device. Experimental results demonstrate that the voltage overshoot decreases from 52 V to 22 V, corresponding to a reduction from 52% to 22% under a 100 V output condition, while the peak drain–source voltage decreases from 152 V to 122 V. The turn-off energy increases from 60.2 µJ to 76.9 µJ due to the slightly reduced switching speed. This trade-off represents the improvement in the comparison between transient suppression and switching loss. In addition, the voltage ringing is significantly attenuated. Although the modified switching strategy slightly increases switching loss, it effectively improves waveform quality and reduces voltage stress. These results confirm that the proposed AGD provides a simple and effective solution for improving the switching robustness and reliability of SiC-based DC–DC boost converters. Full article

The purpose of this paper is to present a techno-economic methodology for assessing the economic sustainability of offshore wind energy development within the Romanian exclusive economic zone (EEZ) of the Black Sea. The methodology illustrates nine key cases in this area that are grouped into three classes, each positioned at a greater distance from the Romanian coast and thus generating different environments given the water depth and wind climate. The data used for the analysis came from the ERA5 database and covered a 20-year span. Six types of wind turbines with capacities ranging from 5 to 9.5 MW were considered. In determining the levelized cost of energy (LCOE), the turbine with the highest production was considered, which turned out to be the Seimens Gamesa 8 MW, and for the economic model, the components related to both capital and operating costs were considered. Following the analysis, it was observed that the B2 site presents the best wind resources, also leading to the highest energy production of x. Regarding the LCOE analysis, values between 66.86 EUR/MWh and 87.39 EUR/MWh were obtained if the entire energy production is considered. Following the simulation with losses, the LCOE increases to values between 92.19 EUR/MWh and 121.85 EUR/MWh. Finally, an optimization calculation was also performed for the site with the highest LCOE considering another foundation time, after which the LCOE decreased to approximately 111.09 EUR/MWh, if we refer to energy production with losses. The results contribute to the economic sustainability evaluation of offshore wind projects in the Romanian Black Sea and influence future investment plans, sustainable energy planning, and renewable energy infrastructure development. Full article

This research presents a continuous-time, deterministic model to address the problem of determining the order quantity and the dynamic pricing policy in scenarios where the quality of the product gradually decays over time. The decision variables include the order quantity as well as the pricing policy, which in turn consists of the initial price and the price reduction rate. Two conflicting objective functions are considered: maximizing profit and maximizing the average quality of the units sold. The paper examines the trade-offs between these two objectives across scenarios with different parameters, such as the price elasticity of the demand, the quality deterioration rate and the elasticity of the demand to quality. The results indicate that, in almost all scenarios, the optimal ordering policy is to order small quantities. Interestingly, in each scenario, there exists a maximum average quality compatible with positive profits. A higher average quality is only possible by incurring losses. Similarly, there is also a limit to the maximum rate of price discounting above which positive profits are not feasible. Full article

In high-step-up ratio converters for portable battery-powered devices, MOSFET switching loss limits efficiency and thermal design. This paper evaluates a multi-stage adaptive gate driver (MS-AGD) after transfer from a 900 V SiC MOSFET high-step-up converter to a 25 V Si MOSFET transformer-based boost circuit. The MS-AGD detects the Miller plateau by differential sensing and controls gate current in four stages through cascode current mirrors. The target-platform comparison combines measured switching waveforms with a temperature-based $\zeta$ coefficient and an apparent $R_{on-effective}$ indicator under a fixed device, load, fixture, pulse sequence, and thermal path. Total switching energy is not determined directly. Tests at 15 frequency points from 23.26 to 125 kHz show that drain-source voltage reaches its valley in about 500 ns with MS-AGD rather than about 1300–1450 ns with fixed-resistor drive and that the MOSFET package-temperature rise is reduced at all tested points by about 25% on average. The fitted apparent thermal-electrical indicator is also lower. These mutually consistent waveform and thermal results indirectly support a reduced turn-on switching-loss contribution while avoiding interpretation of $\zeta$ or apparent $R_{on-effective}$ as direct measurements of total switching loss or instantaneous channel resistance. Full article

During train operation, railway traction-returning current generates a power-frequency magnetic field around the rail, offering a potential energy source for self-powered trackside monitoring nodes. The H-shaped-core magnetic field energy harvester (MFEH) is attractive because it can be installed beneath the rail without enclosing the conductor, yet its output is strongly affected by the coupled rail-core-coil system. To clarify these effects, a three-dimensional electromagnetic-circuit-coupled finite-element model of an experimentally validated laminated-silicon-steel H-shaped-core MFEH was established to examine core and coil parameters. Increasing the center-leg and side-leg lengths weakens demagnetization but intensifies eddy-current losses, causing output power to approach saturation. Under a 50 Hz, 300 A current in a 54E1 rail and series-tuned matching, output power approaches 5.1 W beyond a center-leg length of 1000 mm and 3.25 W beyond a side-leg length of 700 mm. Within the investigated ranges, center-leg and side-leg lengths of approximately 800 and 400 mm provide the best power–volume performance, respectively. Increasing side-leg height or width also improves output. A larger coil span improves output by reducing internal resistance, whereas more turns yield diminishing gains because of higher winding and eddy-current losses. These findings provide a quantitative basis for parametric design of H-shaped-core MFEHs in railway environments. Full article

Therapeutic gardens are increasingly integrated into healthcare planning and design, supported by evidence showing that exposure to nature promotes health and well-being. As urbanisation and densification intensify, rooftop gardens offer a sustainable means of providing health-promoting green spaces in urban settings. This study aimed to deepen understanding of the EBD process behind a purpose-built rooftop garden at an urban Memory Clinic. It examined how the garden was experienced in terms of perceived successes and shortcomings and which design decisions or contextual factors were most influential. A POE was conducted through focus group interviews with healthcare professionals and an interview with the responsible landscape architect. Data were analysed using thematic analysis, producing five themes organised around three questions: How the garden turned out, why it turned out that way, and IF changes were desirable. Findings show that while the garden exceeded expectations regarding aesthetics, restorative qualities, and staff use, it was not used for patient-oriented therapeutic activities as intended. This divergence was linked less to physical design quality than to organisational change, the loss of key actors, insufficient documentation of design intentions, procurement disruptions, shifting clinical priorities, and maintenance arrangements. The study highlights “implementation drift” as a critical risk in EBD processes. Full article

This article examines Martha Graham’s radical reception of the women of Greek tragedy across her performing career, from the early 1930s to her retirement from the stage in 1969. I argue that Graham repeatedly turned to Greek tragic heroines—Electra, Medea, Jocasta, Clytemnestra, Alcestis, Phaedra, and Hecuba—with two interlocking aims: to stage archetypal human emotion, and to confront and make sense of her own personal experiences of love, jealousy, aging, and loss. Inspired by psychoanalysis, Jungian archetypes, and the abstract art of collaborator Isamu Noguchi, Graham was drawn to Greek tragedy’s direct engagement with human suffering. What makes her reception radical is its consistent relocation of tragic conflict from the civic sphere to the psyche: rather than framing female transgression through public judgment, Graham turns the drama inward, giving visible form to what ancient texts leave unstaged—Jocasta’s embodied reckoning with unbearable knowledge, Clytemnestra’s interior logic of injury and justice, Phaedra’s unruly desire brought into full view. The article also introduces the public-facing initiative “Martha Graham & Greek Myth,” which extends this scholarship to broader audiences through presentations that integrate live dance with scholarly discussion, making Graham’s reception of these tragic women accessible beyond the academy. Full article

Nitrous oxide (N₂O) is a greenhouse gas that has a global warming potential approximately 300 times that of carbon dioxide (CO₂). It is largely produced in agricultural soils through nitrification and denitrification processes driven by specific microbial functional genes (e.g., amoA, nirS, and nirK), which represent the main source of its emissions. The intensive use of nitrogen fertilizers increases nitrogen surplus in the ecosystem. This in turn accelerates the risk of nitrogen loss through leaching and volatilization, while also accelerating microbial pathways that drive N₂O emissions in the soil. This issue raises severe environmental concerns within the context of global climate change, particularly through the climate-driven escalation of soil salinity, which further alters the microbial community and increases these emissions. Microbial inoculants, including bacteria and arbuscular mycorrhizal fungi, provide eco-friendly biological solutions to mitigate N₂O emissions from agricultural soils. These inoculants could restore nitrogen balance in the soil by several strategies, such as improving nitrogen use efficiency, competing with native nitrifiers, and upregulating nosZ gene expression. This review highlights the current developments in the utilization of microbial inoculants for N₂O mitigation, focusing on key bacterial genera (e.g., Bradyrhizobium, Dyadobacter, Stutzerimonas, Paenibacillus, and Bacillus) and arbuscular mycorrhizal fungi (AMF, e.g., Rhizophagus and Funneliformis), as well as the mechanisms used by these microorganisms. It also discusses the potential of using microbial inoculants in saline-affected soils, as well as the link between salinity and N₂O emissions. Based on these insights, this review presents a thorough framework for the prospective use of microbial inoculants as an effective solution to sustainable agriculture while reducing the environmental hazards associated with N₂O emissions, which endanger global food and climate systems. Full article

We present FilterForge, a chat-driven VS Code environment that pulls the synthesis, analysis, simulation, and optimization stages of microwave bandpass filter design, normally coordinated by hand across tools written in different languages, into one workflow. A deployed Model Context Protocol (MCP) server exposes deterministic Python implementations of coupling-matrix synthesis, uniform predistortion, topology reconfiguration, a genetic-algorithm transmission-zero selector, a mode-matching engine for H-plane iris-coupled rectangular waveguide geometries, and a skill that generates PyAEDT/HFSS notebooks for various dimensioning design-curves. A language-model orchestrator turns natural-language requests into typed tool calls, while every reported quantity stays inside the deterministic kernels, so the numerics remain reproducible and model-agnostic. We evaluate the call layer on a 45-task benchmark across the five tool categories: gemini-3-flash reaches $96.3\%$ tool-selection and $94.8\%$ full-call accuracy with an $88.9\%$ pass³ rate, which an ablation traces to the curated tool-selection prompt rather than to raw model capability. The mode-matching engine is validated against full-wave HFSS on a six-pole 4 GHz Chebyshev filter tuned from the chat panel, and on an 8 GHz WR-112 counterpart taken end-to-end with no engineer in the loop, where a deterministic critique gates each round until a manufacturable geometry is reached. We then exercise the full workflow on two folded six-pole WR-90 cross-coupled filters at $10\mathrm{GHz}$, a high-selectivity design synthesized against a stop-band mask and a group-delay-equalized variant whose positive cross-coupling uses a pair of side-wall irises, the latter settling to a peak-to-peak in-band group-delay ripple below $1.5\mathrm{ns}$ while recovering the synthesized return loss. Full article

Pubertal initiation critically determines reproductive performance in female pigs. Histone H3 lysine 27 trimethylation (H3K27me3) has been implicated in ovarian development. However, its genome-wide regulatory landscape during the pubertal transition remains unexplored. Here, we obtained transcriptomes of GCs treated with the pharmacological H3K27me3 agonist GSK-J4 or H3K27me3 inhibitor EPZ005687. We found that H3K27me3 substantially remodels the transcriptomic landscape of porcine GCs, with differentially expressed genes significantly enriched in pathways governing cell proliferation and apoptosis. Mechanistically, H3K27me3 suppressed GC proliferation by downregulating the expression of PCNA and promoting apoptosis through upregulation of CASP3, thereby delaying pubertal initiation. Furthermore, genome-wide ChIP-seq analysis on porcine ovaries from pre-pubertal and in-pubertal gilts revealed higher H3K27me3 enrichment around transcription start sites in the In-puberty stage than in the Pre-puberty stage. Genes with promoters exhibiting reduced H3K27me3 occupancy during the pubertal transition were enriched in pathways related to sex differentiation and serine-type endopeptidase inhibitor activity. Notably, secretory leukocyte peptidase inhibitor (SLPI) was identified by ChIP-qPCR as a direct target repressed by H3K27me3. Functional validation demonstrated that SLPI promoted GC proliferation and inhibited GC apoptosis in vitro. Intraperitoneal injection of LV-Slpi or sh-Slpi into C57BL/6J mice showed that Slpi accelerated pubertal initiation of mice in vivo. Collectively, our findings confirmed that developmental stage-specific loss of H3K27me3 at the SLPI promoter derepressed SLPI transcription, which in turn promoted porcine GC proliferation, suppressed apoptosis, and facilitated pubertal initiation in mice. These results provided valuable insights into the epigenetic regulation of pubertal initiation in mammals. Full article

Spinocerebellar ataxia type 7 (SCA7) is a hereditary disorder characterized by degeneration of the cerebellum and retina. SCA7 is caused by the expansion of a polyQ tract in the ATXN7 gene, leading to protein misfolding, transcriptional dysregulation, and neuronal/glial degeneration. Recently, altered DNA damage response (DDR) was revealed in SCA7, which may contribute to disease pathogenesis. Impaired DDR causes DNA damage, which in turn triggers cellular senescence. Consistently, senescent cells were identified in the cerebellum Purkinje layer of an SCA7 mouse model. In this study a Müller glial model (MIO-M1) expressing normal (10Q) or expanded (64Q) ataxin-7 was utilized to ascertain whether mutant protein induces genomic instability and consequently the emergence of senescence. PolyQ ataxin-7 elicits nuclear lamina disorganization, γH2AX foci (DDR marker), micronuclei and telomere shortening, which indicate genomic instability. Furthermore, 64Q cells expressing polyQ ataxin-7 exhibited senescence hallmarks, including heterochromatin loss and increased senescence-associated β-galactosidase activity, but not p21 nor p53 expression. Instead of the senescence-associated enlargement of nucleoli, these cells exhibited nucleolar disaggregation. Together, these findings indicate that the expression of polyQ ataxin-7 disrupts the nuclear architecture, thereby inducing genomic instability. This, in turn, results in a senescence-like phenotype, a phenomenon that may contribute to glial pathogenesis. Full article

Real-time roadway surveillance now leans hard on automated detection. How a model trained in one geographic context actually behaves on another, though, is still underexplored for Southeast Asian deployments. We answer that question for Thai roadway closed-circuit television with a cross-domain validation framework. A YOLOv11n (Ultralytics v8.2.0; Ultralytics, Los Angeles, CA, USA) detector trained with focal loss feeds a confidence-aggregation step that turns per-detection scores into a per-frame accident score, and we put four aggregation operators head-to-head. Reliability comes from DeLong variance estimation paired with non-parametric bootstrap on 1245 Thai frames that carry 23 positive accident events. Under maximum-class aggregation the proposed configuration reaches a frame-level AUROC of 0.959 ± 0.020 across three random seeds. Under top-K aggregation it reaches 0.965 ± 0.018. Per-seed DeLong 95 percent intervals exclude chance performance throughout. We also evaluate three baseline configurations: YOLOv5su comes in at 0.738, YOLOv8n at 0.868, and a Chiang Mai-tuned YOLOv11n variant at 0.918. The architectural progression seen on standard benchmarks therefore carries cleanly into the cross-domain setting. The same Chiang Mai-tuned variant reached an in-domain mAP50 of 0.952 yet only 0.918 cross-region AUROC on a separate Thai region, which is a quiet but clear signal that geographic proximity within a country does not on its own remove distributional shift. Bounding-box localisation appears as a secondary diagnostic because the operational target here is frame-level alerting rather than pixel-precise annotation. Edge deployment optimisation falls outside the present scope. What the work leaves behind is a reproducible baseline and a statistical protocol that follow-up Southeast Asian roadway-safety research can build on. Full article

Surge reliability is a crucial aspect of silicon carbide (SiC) metal-oxide-semiconductor field-effect transistor (MOSFET) reliability. This study investigates the degradation behavior and mechanisms of switching characteristics in 1.2 kV planar-gate SiC MOSFETs under repetitive surge current. A surge current test platform is established to conduct surge tests on the device, while monitoring the evolution of its switching characteristics. The results indicate that after 4000 surge current cycles, the device’s turn-on delay time (t_d(on)), rise time (t_r), and turn-on loss (E_ON) show no significant changes. In contrast, the turn-off delay time (t_d(off)), fall time (t_f), and turn-off loss (E_OFF) increase by 9%, 7.5%, and 8.3%, respectively. Switching characteristics variations are closely linked to the reduction in threshold voltage (V_TH) and the increase in gate-source capacitance (C_GS) and gate-drain capacitance (C_GD). The degradation of these parameters stems from the accumulation of positive trapped charge in the gate oxide layer above the channel and junction field-effect transistor (JFET) region. The increase in charges results from the combined effects of negative gate bias and cyclic high temperature induced by repetitive surge current. This study provides a theoretical basis for the comprehensive understanding of the impact of surge current on SiC MOSFET performance. Full article

Background: In elderly patients with hypoalbuminaemia, hypoproteinaemia and advanced-stage PUs, chronic inflammation and wound-related protein loss contribute to a self-perpetuating circulus vitiosus, in which protein depletion drives deterioration of tissue repair processes, and in turn, ongoing wound-related catabolism further amplifies systemic protein loss. In this context, reduced serum albumin and total protein represent integrated indicators of systemic inflammatory and catabolic burden associated with delayed wound healing. Aim: This study evaluated the association between individualized nutritional replacement therapy and pressure ulcer healing in malnourished geriatric and palliative patients, using serum albumin, total protein, and PUSH score as longitudinal outcome indicators. Methods: A total of 78 malnourished geriatric and palliative patients with PUs, multiple comorbidities, and poor nutritional status (hypoalbuminemia and/or hypoproteinaemia) receiving patient-tailored nutritional replacement therapy participated in this study. PU assessment using the PUSH version 3.0 tool, as well as measurements of serum albumin and total protein concentrations, were performed on days 0, 30, 60, and 90. Results: Our study demonstrates significant improvement in the serum albumin levels, from 30.2 ± 6.19 at baseline to 42.1 ± 5.59 at day 90. Similarly, total protein concentrations increased from 57.8 ± 9.66 at baseline to 70.6 ± 7.03 at day 90. The improvement in protein status was accompanied by a significant reduction in the PUSH score, from 10.9 ± 2.94 at the first assessment to 2.9 ± 2.63 at the final assessment. Spearman’s rank-order correlation analysis between serum albumin, total protein, and PUSH score demonstrated a significant moderate inverse correlation at later assessment points (day 60 and 90). Conclusions: Individualized and targeted replacement therapy was associated with improved protein status and reduced pressure ulcer severity. Increases in serum albumin and total protein paralleled a marked reduction in PUSH scores, suggesting attenuation of the inflammatory-catabolic circulus vitiosus and a progressive shift toward wound healing in geriatric and palliative patients. Full article

This study investigates the effect of sintering temperature on the hot-corrosion behavior of Ti-6Al-4V alloy in a molten salt environment. Samples were sintered at 800 °C, 900 °C, 1000 °C and 1100 °C, then exposed to the Na₂SO₄—25%NaCl for 300 h at 650 °C. The corrosion kinetics were evaluated by measuring the mass change in the specimens, and the results were correlated with their corresponding corrosion rates. The results show that the sintering temperature drives corrosion kinetics by influencing the sample density and grain size. The sample sintered at 900 °C shows a low corrosion rate due to its refined microstructure. This refined microstructure provides a high grain boundary density, which serves as a diffusion path and enables the formation of a dense, protective Al₂O₃–TiO₂ layer, as confirmed by XPS. In contrast, the sample sintered at 800 °C exhibits high porosity, resulting in an initial weight loss due to molten-salt penetration and evaporation of volatile metal chlorides. The samples sintered at 1000 °C and 1100 °C exhibit coarsened grains, leading to a thicker, brittle oxide layer and severe delamination, which in turn result in high corrosion rates. The results show that optimizing the sintering temperature to around 900 °C would enhance hot-corrosion resistance in salt-contaminated environments. Full article