Search Results (18,763)

Nowadays, numerical simulation methods are advanced and widely used in industry, enabling the modeling of complex systems from printed circuit boards (PCBs) to full power converters. Among many isolated topologies, the phase-shift full-bridge (PSFB) topology is a well-established solution for isolated DC–DC conversion in electric vehicles. Therefore, this paper proposes a broadband electromagnetic compatibility (EMC) modeling methodology for a custom-designed 1 kW gallium nitride (GaN)-based PSFB converter intended for an electric vehicle (EV) DC powertrain. Moreover, the approach combines full-wave electromagnetic simulation with circuit-level simulation, including parasitic effects from PCB layout, power harnesses, and discrete components. Thus, the virtual prototype is assessed within a complete virtual test bench compliant with the standard Comité International Spécial des Perturbations Radioélectriques (CISPR) 25 over the 150 kHz–108 MHz range to capture common-mode (CM) and differential-mode (DM) conducted electromagnetic interference (EMI). Results show that the converter achieves efficiencies of 97.26% in standalone mode and 97.03% when integrated into the full DC powertrain. However, the conducted EMI assessment reveals that both CM and DM emissions exceed CISPR 25 Class 2 limits across the entire spectrum, with excess levels reaching up to 72 dBµV. Therefore, power harnesses significantly increase EMI levels at low frequencies due to the distributed inductance and stray capacitance. Finally, this study demonstrates the value of virtual prototyping for simulation-based EMI prediction in early-stage power converter design. Full article

High-resolution, long-term gridded meteorological datasets from in situ observations are crucial for ecosystem monitoring, soil diagnostics, hydrological modelling, and Earth system model evaluation. This study presents two enhanced real-time adaptations of Thornton’s Daymet V4 interpolation method. Daymet4-r1 uses a traditional calibration strategy with exhaustive parameter search, while Daymet4-r2 applies a global optimization algorithm (find_min_global from the dlib library) to adjust parameters automatically at each time step. Both methods were tested over Tuscany using high-resolution terrain and a dense observation network. Validation with leave-one-out method was carried out for the period 1995–2011 for both versions, while Daymet4-r2 underwent extended evaluation from 1991 to 2024 to assess seasonal dynamics and long-term variability. Results show that Daymet4-r2 outperforms Daymet4-r1 and the original Daymet V4 for all variables (mean absolute error of 1.24 mm, 1.06 °C, 1.29 °C, 6.26%, 0.78 m/s, and 2.04 hPa for precipitation, maximum and minimum temperature, relative humidity, wind speed, and sea level pressure, respectively). The largest improvement was observed in minimum temperature due to an enhanced approach for detecting and modelling thermal inversions. The high performance, flexibility, and ability of Daymet4-r2 to operate without prior calibration highlight its potential for model verification, real-time environmental monitoring, and integration into climate services. Full article

Background/Objectives: COPD patients often complain of severe dyspnea when walking uphill, even up a mild incline. This study aimed to determine whether the dyspnea experienced during uphill walking is disproportionate to the increased mechanical work required to overcome gravity. Methods: Fourteen COPD patients (FEV₁ 49 ± 11% predicted) and nine healthy participants performed three symptom-limited exercise tests on a treadmill, each at a fixed grade: 1%, 2.5%, and 4% for COPD patients; and 1%, 3%, and 5% for healthy participants. Treadmill speed was increased stepwise (3 min/stage). Inspiratory capacity (IC) maneuvers were performed during the last minute of each stage. Borg dyspnea scores (0–10) at the different inclines were compared at a uniform level of oxygen uptake (iso-$\dot{\mathrm{V}}$O₂). Results: Borg dyspnea scores by COPD patients at the highest iso-$\dot{\mathrm{V}}$O₂ attained were significantly higher at 4% treadmill grade compared to 2.5% and compared to 1% grade (7 ± 2 vs. 5 ± 2 vs. 5 ± 2, respectively; p < 0.001 for 4% vs. 1% grade, p < 0.005 for 4% vs. 2.5%). Dynamic hyperinflation worsened with grade, as reflected by decrease in inspiratory reserve volume (IRV) at the highest common iso-$\dot{\mathrm{V}}$O₂ attained: 798 ± 336 mL at 1% grade vs. 698 ± 325 mL at 2.5% (p < 0.004) vs. 564 ± 350 mL at 4% (p < 0.002 for 4% vs. 1%; p < 0.004 for 4% vs. 2.5%). In contrast, healthy participants showed no significant grade-dependent differences in dyspnea or IRV at iso-$\dot{\mathrm{V}}$O₂. Conclusions: Walking uphill in itself increases breathlessness of COPD subjects at iso-$\dot{\mathrm{V}}$O₂, suggesting that the increased dyspnea cannot be explained simply by the increased work. This phenomenon may be related to dynamic hyperinflation, which is worse at steeper inclines. Full article

Reliable spatial georeferencing of mobile mapping platforms is a fundamental prerequisite for high-fidelity urban remote sensing products such as 3D point clouds and digital twins. However, in deep urban canyons, severe signal occlusion and multipath effects reduce visible GNSS satellites, causing ambiguity resolution (AR) failure and degraded observation geometry for UGV-borne systems. Conventional Vehicle-to-Vehicle (V2V) cooperation offers limited improvement due to symmetric ground-level occlusion. To overcome this, we propose an asymmetric GNSS/UWB fusion method that introduces Unmanned Aerial Vehicles (UAVs) as high-altitude dynamic spatial anchors to reconstruct the 3D observation geometry. Two contributions are presented: (i) an asymmetric heterogeneous stochastic model coupling carrier-to-noise ratio (C/N0) and elevation angle to handle the quality disparity between air and ground sensor links, preventing multipath contamination of high-fidelity UAV observations; and (ii) a dynamic baseline constrained least-squares algorithm integrating Ultra-Wideband (UWB) ranging to stabilize GNSS positioning under high-dynamic relative motion. Validated through high-fidelity simulations and field experiments, the method achieves a 98.2% AR success rate and sub-decimeter 3D accuracy under extreme occlusion (≤3 visible satellites), while urban-canyon tests demonstrate 100% positioning availability across all evaluated epochs and reduce the 95th-percentile 3D error from 7.25 m to 0.19 m under the tested single-UAV/single-UGV configuration. The framework supports smart city modeling, 3D reconstruction, and infrastructure monitoring. Full article

Background: Oxidative stress contributes significantly to premature skin aging and inflammatory dermatological conditions. While plant-derived antioxidants have demonstrated considerable promise in topical applications, Bougainvillea glabra Choisy remains underexplored in standardized pharmaceutical dosage form development despite its documented phytochemical richness. Objective: This study aimed to develop, standardize, and characterize topical cold cream formulations incorporating B. glabra ethanolic leaf extract, with HPTLC-based quantification of marker compounds, validated antioxidant assessment, and preliminary dermal safety evaluation. Methods: The ethanolic leaf extract was prepared by maceration and characterized by preliminary phytochemical screening and HPTLC fingerprinting with quantitative densitometric analysis of quercetin and pinitol. Three cold cream formulations were developed at 10% (F1), 20% (F2), and 30% (w/w) (F3) extract loading. Formulations were evaluated for organoleptic properties, pH, homogeneity, spreadability, and viscosity. Antioxidant activity was assessed using a validated methanol extraction procedure followed by DPPH radical scavenging and potassium permanganate reduction assays. Ex vivo skin permeation was evaluated using Franz diffusion cells with freshly excised goat skin. Accelerated stability was conducted at 40 ± 2 °C/75 ± 5% RH for 90 days with HPTLC-based marker retention monitoring. Primary dermal safety was assessed in Wistar albino rats (n = 6) following OECD Test Guideline 404. Results: Quantitative HPTLC confirmed quercetin (4.82 ± 0.14 mg/g dry extract) and pinitol (2.31 ± 0.09 mg/g) as marker compounds, with linearly increasing content across F1–F3. All formulations demonstrated acceptable physicochemical properties (pH 5.7–5.9, viscosity 440,000–460,000 cP, spreadability 11.8 ± 0.3 cm·g/s). F3 exhibited the highest DPPH scavenging activity (56.68 ± 1.05%) with IC₅₀ of 1.3 ± 0.1% w/v, demonstrating a 3.2-fold improvement over F1. Extraction recovery from the cream matrix was 96.4–97.1%, validating the antioxidant data. Ex vivo quercetin permeation through goat skin reached 51.3 ± 2.8 μg/cm² at 24 h for F3, following Higuchi diffusion kinetics (R² > 0.99). No dermal irritation was observed (Primary Irritation Index = 0). Accelerated stability confirmed ≥98.3% retention of both marker compounds and antioxidant activity after 90 days. Conclusions: B. glabra leaf extract was successfully incorporated into a physicochemically stable, non-irritating cold cream with demonstrated dose-dependent antioxidant efficacy and cutaneous delivery capability. The study establishes preliminary dermal safety and in vitro antioxidant efficacy warranting further controlled clinical evaluation. Full article

Background: Digital exclusion remains a key barrier to equitable access to digital health services, particularly among individuals with visual impairment. Limited access to devices and digital literacy restricts participation in increasingly digital-first healthcare systems. This study aimed to evaluate the feasibility and exploratory service impact of a device recycling and digital inclusion pilot at a tertiary ophthalmic hospital. Materials and Methods: The six-month pilot at Moorfields Eye Hospital involved the refurbishment and distribution of donated electronic devices (laptops and mobile phones) alongside personalised digital literacy training delivered by trained volunteers. Twenty-two patients with visual impairment were enrolled; 18 completed the programme. Pre- and post-intervention questionnaires assessed digital engagement and confidence across key domains. Paired data were analysed using the Wilcoxon signed-rank test. Results: Across 216 item-level engagement responses, the number of responses indicating daily engagement increased from 31 to 49. Mean self-reported confidence scores improved from 3.1 to 5.1 out of 10 (Wilcoxon signed-rank test, V = 148, p = 0.0008; r = 0.81). Patients reported increased use of email, messaging, online forms, and General Practice (GP) appointment systems. Using secondary lifecycle data and modelled estimates, the reuse of refurbished laptops was associated with an indicative saving of approximately 5.3 tonnes of CO₂-equivalent emissions. Conclusions: This service evaluation suggests that a multi-component intervention combining device provision with tailored support may improve digital engagement and confidence among patients with visual impairment. These findings support the feasibility of integrating digital inclusion initiatives within ophthalmology services, with potential co-benefits for environmental sustainability. Full article

This study examined how duct inclination influences particle removal in a hybrid acoustic–electrostatic filtration system operating at low airflow velocities. The experiments were carried out in a 150 mm diameter air duct at airflow speeds of 0.50 and 0.75 m/s, with duct inclinations of 45° and 90°. Aerosol particles with properties similar to marine diesel exhaust, spanning a size range of 0.2–10 µm, were introduced at stable concentrations. Electrostatic voltages of 17.5 and 20 kV were applied, together with acoustic voltages between 100 and 200 V. Particle removal was evaluated using both size-resolved and overall collection efficiencies. The results show that duct inclination mainly affects the removal of fine and medium-sized particles. The largest differences were observed for particles around 1 µm in diameter, where the vertical duct increased collection efficiency by up to 27 percentage points at an airflow speed of 0.75 m/s. For larger particles in the 5–10 µm size range, high removal efficiency was achieved under all tested conditions, and duct orientation had a smaller influence on collection performance. Overall, the results confirm that duct inclination has a clear and measurable effect on the performance of hybrid acoustic–electrostatic filtration systems operating at low airflow velocities. Full article

The surface treatment of inner walls in large-aspect-ratio tubes plays a pivotal role in ensuring long-term stable operation of equipment. Although traditional methods like electroplating are widely used, they often suffer from limited protection, poor adhesion, and environmental drawbacks. Magnetron sputtering (MS) represents a promising alternative; however, few studies have successfully developed coatings that balance high hardness with strong adhesion on the inner walls of tubes featuring large length-to-diameter ratios. In this study, we deposited Cr coating on the inner wall of a tube with an aspect ratio of 13.3 using MS technology, and regulated the process to enhance the hardness and adhesion strength of the coating. By systematically varying the bias voltage, the microstructure and properties of the coating were effectively tailored. Results show that a bias voltage of −200 V promotes pronounced (110) preferred orientation in the Cr coating, yielding an optimal combination of high hardness (~11.54 GPa) and a low coefficient of friction (~0.4). Furthermore, scratch testing revealed robust coating–substrate adhesion strength, with initial failure loads exceeding 50 N under various bias conditions. These findings demonstrate that optimizing the bias voltage during MS deposition is an effective approach for fabricating high-performance Cr coatings, providing a viable strategy to improve the durability and reliability of high-end equipment. Full article

Denil fishways exhibit limited passage efficiency for weak-swimming and benthic species, partly due to severe near-bed hydrodynamics generated by the sharp V-notch apex of conventional baffles. Modifying bottom geometry is a promising optimization pathway, but previous studies often lack rigorous comparison under constrained baffle openness ratios. This study employed CFD with the RNG k – ε turbulence model to evaluate conventional V-shaped (TDF), equivalent U-shaped (SCDF), and rectangular (RDF) baffles under a unified openness ratio. A layered hydrodynamic evaluation framework demarcated by the effective blocking height was developed to distinguish flow responses in the upper jet-dominated and lower baffle-controlled layers. Results show that the upper-layer conveyance indicators remain broadly comparable across configurations, whereas the lower-layer indicators show configuration-related differences within the tested discharge range. The RDF and SCDF reduce lower-layer mean velocity and TKE relative to the TDF baseline across the tested discharge range, with the RDF achieving the larger velocity reduction and the SCDF the larger TKE reduction. The maximum relative reduction in lower-layer TKE, approximately 22%, occurs under intermediate discharge. These results suggest that bottom baffle geometry can provide a potential means of adjusting near-bed hydraulic conditions in Denil fishways, although the ecological consequences require further verification. Full article

To address the difficulty of real-time detection of seed-filling performance in pneumatic suction seed metering devices under high-speed operation—where seed targets are tiny, prone to adhesion, and affected by motion blur—this paper proposes a lightweight online detection algorithm, YOLOv8n-MA. First, according to the seed adsorption characteristics of the suction holes, the detection targets are divided into three categories: none, one, and two. Second, based on YOLOv8n, the backbone network is replaced with MobileNetV1 to reduce computational cost, and an ACmix attention module is integrated into the Neck to enhance feature representation for the three suction-hole states. Finally, to meet the demand for low-latency inference on resource-constrained devices, the model is deployed on an edge computing controller to achieve real-time detection. Experimental results show that, compared with the original YOLOv8n, the parameters and FLOPs of YOLOv8n-MA are reduced by 34.4% and 59.8%, respectively, while the mean average precision (mAP) is improved by 2.0% to 96.8%, achieving a superior trade-off between accuracy and efficiency over other detection models of the same category, such as YOLOv5n, YOLOv9n, and YOLOv10n. In field tests, the detection accuracy reaches 95.02% at 12 km/h and 92.65% at 15 km/h. The proposed method provides effective technical support for the intelligent monitoring and control of precision seeding under high-speed operation. Full article

Autonomous unmanned aerial vehicles (UAVs) must decide when to trust onboard perception, when to request edge support, and when to avoid acting under poor visual or communication conditions. This study develops a risk-aware edge-assisted UAV perception framework that combines calibrated visual confidence with next-window service-level agreement (SLA) feasibility. The local branch uses MobileNetV3-Small for fast onboard color recognition, while the edge branch uses ResNet-18 for stronger remote inference. Low-confidence samples are offloaded only when the SLA predictor estimates that the wireless link is feasible; otherwise, the system enters fallback, meaning that the current prediction is not treated as immediately actionable. The evaluation follows a hard cross-illumination split: indoor and fluorescent light samples are used for training and validation, and indoor night and sunlight samples are reserved for testing. Under this setting, the local model achieves 76.89% accuracy and 73.25% macro-F1, while the edge model achieves 81.26% accuracy and 77.58% macro-F1. The SLA predictor, trained on enhanced telemetry features while preserving the original target label, achieves 85.74% accuracy, 85.57% macro-F1, 0.9420 ROC-AUC, and 0.9585 PR-AUC on temporally held-out records. The joint policy achieves 93.23% coverage and 79.90% success over active decisions, using local inference for 82.76% of the samples, edge offloading for 10.47%, and fallback for 6.77%. These results indicate that the framework is best understood as a tunable risk management layer for UAV perception rather than a pure accuracy maximization classifier. It avoids blind offloading and reduces forced decisions when both visual confidence and communication feasibility are weak. Full article

Lactic acid bacteria (LAB) have been widely utilized in the production of fermented foods worldwide due to their well-established health-promoting benefits for both humans and animals. In addition to their nutritional value, LAB exhibit antagonistic activity against foodborne pathogens, particularly Salmonella spp., which are commonly associated with livestock and animal production systems. LAB exert a range of biological effects that can inhibit the growth of Salmonella and modulate its virulence. In the present study, the antagonistic potential of Weissella confusa WM36 was evaluated based on its ability to inhibit S. Typhimurium growth, disrupt biofilm formation, and suppress the expression of virulence-associated genes. A preliminary safety assessment of W. confusa WM36 was conducted through hemolytic activity and antibiotic susceptibility profiling. In addition, the biofunctional properties of its cell-free supernatant (CFS), herein referred to as postbiotic metabolites, were investigated with a particular focus on antioxidant activity. Experimental results demonstrated that W. confusa WM36 and its CFS at 40% (v/v) achieved a complete reduction (100%) of S. Typhimurium cell counts within 6 to 12 h of treatment. Furthermore, CFS at 20% and 40% (v/v) significantly impaired biofilm formation, while treatment with 20% (v/v) CFS markedly downregulated the expression of key virulence genes. The strain WM36 exhibited α-hemolytic activity and showed susceptibility to most of the antibiotics tested, although resistance to ceftriaxone and trimethoprim–sulfamethoxazole was observed. These findings provide preliminary information regarding its safety characteristics; however, further molecular and in vivo investigations are required to comprehensively evaluate its safety for practical applications. Additionally, the CFS exhibited notable antioxidant activity, with DPPH radical scavenging capacity of 8.90 ± 0.06 mM Trolox equivalents and ABTS radical scavenging power of 13.10 ± 1.42 mM Trolox equivalents. Collectively, these findings highlight the potential of W. confusa WM36 and its postbiotic metabolites as promising biocontrol and functional agents against S. Typhimurium, while further safety validation remains necessary. Full article

The increasing incidence of traffic accidents involving elderly pedestrians has highlighted the necessity for effective strategies to improve visibility in low-light environments. Conventional safety garments based on retroreflective materials or optical fibers exhibit limitations, including passive operation and low luminance. In this study, a textile-based organic light-emitting diode (OLED) safety garment with automatic light-sensing functionality is proposed to overcome these limitations. The OLED devices were fabricated on an ultrathin polyethylene terephthalate (PET) substrate and transferred onto a textile substrate to maintain flexibility and wearability. A light-emitting module incorporating a LilyPad Arduino and ambient light sensor was implemented to enable automatic illumination under low-light conditions. The fabricated textile-based OLED exhibited a luminance of 550 cd/m² at 4.5 V and maintained stable performance after transfer, with a T₅₀ lifetime of 485 h. Thermal analysis showed a minimal temperature increase of 2.9 °C after 5 h of operation, remaining below body temperature. Moreover, mechanical testing confirmed over 95% luminance retention after 2,000 bending cycles. The fabricated OLED-based luminous safety garment exhibited lightweight wearability with a total weight of 140 g and improved visibility at observation distances of up to 50 m under low-light conditions. These results indicate that the proposed OLED-based luminous safety garment can offer a viable solution for enhancing the safety of elderly pedestrians. Full article

Synthetic Aperture Radar (SAR) is widely used for marine oil spill surveillance due to its all-weather capabilities and sensitivity to sea surface roughness. However, oil slicks often appear as dark formations that can be confounded with visually similar “look-alikes”, making automated detection and boundary delineation challenging. This study proposes a two-stage deep learning framework for oil spill mapping in Sentinel-1 SAR imagery. First, a ConvNeXt-T classifier screens image patches for likely slick presence, reducing the search space for dense prediction. Second, spill boundaries are extracted with a domain-adapted Segment Anything Model (SAM) configured for prompt-free, single-shot segmentation. The input representation is enhanced by combining preprocessed Sentinel-1 VV backscatter with Gray-Level Co-occurrence Matrix (GLCM) texture measures (homogeneity and variance) to better separate oil from heterogeneous background sea at the segmentation level. Quantitative evaluation against established segmentation baselines demonstrates that our adapted SAM achieves the highest overall accuracy, reaching an F1-score of 0.86. This outperforms traditional models such as UNet and CBDNet (0.83), as well as DeepLabV3, SegNeXt, and OFCNet (all at 0.82). Furthermore, an analysis of the wind speed on the test set shows that wind speed affects detectability but does not by itself determine segmentation quality. The results indicate that combining transformer-based screening with efficient foundation-model adaptation can provide accurate and scalable oil spill mapping for operational SAR monitoring. Full article

The efficacy of plant-derived antimicrobials in meat systems is frequently limited by interactions with proteins, lipids, and other food matrix components that reduce the bioavailability and antimicrobial activity of phytochemicals. This study evaluated the antimicrobial effectiveness of Verbascum sinaiticum (V. sinaiticum) leaf extract encapsulated using maltodextrin (MD), gum arabic (GA), and a maltodextrin–gum arabic blend (MDGA, 8:2 w/w) through freeze-drying for application in raw beef during refrigerated storage (4 °C). The encapsulation systems exhibited process yields of 42.5–54.7%, encapsulation efficiencies of 78.3–92.5%, and loading capacities of 18.5–24.3 mg GAE/g DW, with MDGA showing the highest encapsulation efficiency. The effects of encapsulation on microbial inhibition, physicochemical properties, and sensory quality were investigated over 15 days of storage. Aerobic plate counts in the control increased from 3.04 to 8.26 log CFU/g, whereas encapsulated treatments showed significantly lower final counts (p < 0.05), reaching 7.89 log CFU/g (MD), 7.96 log CFU/g (MDGA), and 7.95 log CFU/g (GA). Similarly, encapsulated treatments reduced Escherichia coli counts during storage, with maltodextrin (MD) exhibiting the greatest inhibitory effect (6.23 × 10⁵ CFU/g) compared with the control (6.93 × 10⁵ CFU/g) on day 15. However, reductions in Staphylococcus aureus, E. coli, Candida albicans, and Bacillus cereus remained below 1 log CFU/g, indicating limited antimicrobial efficacy under the tested conditions. All encapsulated treatments slowed pH increases during storage (6.20–6.34) relative to the control (6.62) on day 15 and preserved aroma quality throughout the storage period. Overall, encapsulation improved the antimicrobial performance of V. sinaiticum extract compared with the free extract, particularly in MD-based systems; however, the antimicrobial effects in beef remained modest. These findings highlight both the potential and current limitations of encapsulated plant-derived antimicrobials for meat preservation and emphasize the need for optimized delivery systems to enhance efficacy in complex food matrices. Full article