Search Results (1,592)

Schottky barrier diodes (SBDs) based on low-dimensional materials are of interest for high-speed electronics due to their intrinsic nonlinear transport characteristics. In this work, aligned carbon nanotube Schottky barrier diodes (ACNT-SBDs) were systematically studied through electrical characterization, small-signal modeling, and large-signal nonlinear measurements. Devices with channel widths ranging from 50 to 500 µm were fabricated to examine size-dependent direct-current and high-frequency behavior. Clear Schottky rectification and pronounced geometry-dependent characteristics were observed, with the widest device achieving an intrinsic cutoff frequency of up to 282 GHz. Based on measured S-parameters, a refined small-signal model incorporating a parallel resistance–constant phase element (CPE) branch was developed, providing substantially improved agreement with measured S- and Y-parameters and phase response compared with the classical model. The extracted CPE parameters exhibit systematic dependence on channel width, indicating distributed junction charge dynamics associated with carbon nanotube interfaces. Furthermore, the large-signal nonlinear behavior was evaluated using an anti-parallel diode configuration, achieving a third-harmonic output power of −22.58 dBm at 30 GHz under zero-bias operation. This work provides a comprehensive experimental and modeling framework for understanding the high-frequency and nonlinear behavior of ACNT-SBDs. Full article

Microplastics (MPs) are pervasive contaminants that enter the food chain and cause health issues. However, the size-dependent effects of MPs on lipid metabolism remain inadequately characterized. Using Caenorhabditis elegans (C. elegans), we investigated the size-dependent toxicity of polystyrene (PS)-MPs as model contaminants with sizes of 100 nm and 1 μm, respectively. We evaluated multiple phenotypic endpoints, including lifespan, growth (body length and width), locomotion (head thrashes and body bends), reproduction, and intestinal lipofuscin. The expression of representative lipid metabolism-related transcripts was validated by quantitative PCR. Untargeted metabolomics profiling detected 831 differential metabolites (451down-regulated and 380 up-regulated) across both PS particle exposure groups, with over-representation of lipid metabolic pathways. Integration of multi-omics (transcriptomics and metabolomics) highlighted acdh-1, ech-6, hach-1, and sur-5 as core lipid-metabolism genes; RNA interference confirmed that knockdown of these target genes abolished the size-dependent differences in fat accumulation induced by MPs. Notably, it revealed elevated linoleic acid and taurocholic acid, signature metabolites indicative of disrupted lipid turnover by our metabolomic profiling. Collectively, our findings demonstrate that exposure to PS-MPs disrupts lipid homeostasis in C. elegans by perturbing mitochondrial function and key metabolic pathways, which in turn impairs growth, development, feeding, and reproductive capacity. Critically, these disruptive effects exhibit a strong size dependency, with 100 nm PS particles inducing more severe perturbations than the 1 μm particles, and provide novel mechanistic insight into MP-induced metabolic abnormalities, underscoring the importance of considering particle size in assessing the environmental and health risks of MP contamination. Full article

The development of multifunctional smart packaging materials capable of simultaneously monitoring temperature and suppressing microbial contamination is critical for next-generation food and pharmaceutical safety systems. In this study, we report the design and characterization of a polymeric film integrating a spin crossover (SCO)-based thermochromic sensor with zinc oxide (ZnO) nanoparticles serving as an antimicrobial agent. Beyond the individual functionalities, we demonstrate a synergistic effect between SCO and ZnO components. Notably, the SCO transition of the pristine SCO complex is broadened, and the hysteresis width of the transition is decreased (i.e., from 6 K to 1.5 K, 2 K, and 1.5 K for ZnO loading of 0.5%, 1%, and 2%, respectively), in the polysulfone–SCO–ZnO composites. Migration studies reveal that the co-existence of SCO and ZnO does not disrupt the low release profile of active agents, which remains low across ZnO loadings. The polymeric film exhibited dose-dependent antiproliferative activity against MCF-7 breast cancer cells, with a significant reduction in cell viability observed only at the highest tested concentration, indicating cytotoxic potential. This multifunctional platform represents a promising advancement in smart packaging design, enabling real-time thermal indication combined with the integration of ZnO as a literature-established antimicrobial component, within a non-toxic, and visually transparent system. Collectively, the material’s properties offer promising scalability for both food and pharmaceutical packaging applications where visual clarity, antimicrobial integrity, and temperature monitoring are imperative. Full article

Background and Objectives: Anastomotic leak following total gastrectomy and Roux-en-Y reconstruction remains a challenging and potentially morbid clinical scenario. Systemic support and resuscitation with simultaneous local sepsis control remain pillars of treatment. The therapeutic strategy may vary among different centers depending on the severity of clinical presentation, the degree of contamination and the hospital resources. The aim of this study is to introduce the rendezvous stenting technique, which combines washout of the abdominal cavity and endoscopic stenting under direct vision in selected patients who require reoperation. Materials and Methods: A retrospective descriptive analysis of severely ill patients suffering an anastomotic leak from an esophagojejunal anastomosis, who had been operated on in our department during the last five years was performed. Patient demographics, perioperative data and surgical outcomes were collected. Results: Since 2018, six anastomotic leak patients underwent stenting of anastomotic leak using the rendezvous technique during reoperation. Stenting was effective in controlling local contamination in five out of six patients (83.3%). One patient required repeat stent placement due to improper stent width. Conclusions: Anastomotic stenting using the rendezvous technique is a safe and feasible technique. Combining drainage of the abdominal cavity and stent fixation allows for control of the contaminated field as well as minimizing the risk of stent migration. Full article

Accurate prediction of network-wide delay is crucial for air traffic management and passenger service. However, the inherent complexity of large-scale air traffic networks, with their dense interconnectivity and multi-dimensional operational dynamics such as flight connectivity, makes this task highly challenging. While Graph Neural Networks (GNNs) offer a promising framework, prevailing models are constrained by a “node → edge → node” representation paradigm, which fails to preserve the high-fidelity, edge-centric operational data that encodes delay propagation paths. To overcome this limitation, we propose a novel edge-based GNN. Our approach begins with a flight-connectivity-informed delay characterization, introducing delay width and delay strength as core metrics. The model implements an “edge → node” message-passing mechanism that explicitly encodes inbound and outbound flights, enabling direct learning of delay diffusion dynamics along air routes. Extensive experiments on real-world datasets demonstrate that our method outperforms state-of-the-art benchmarks, achieving the lowest RMSE, MAE, and MSE. A layered performance analysis reveals a key strength: the model delivers superior accuracy at major hub airports—which are critical to network performance—while maintaining robust precision at small-to-medium-sized airports. This balanced capability underscores the model’s practical utility and its enhanced capacity to capture the essential spatial–temporal dependencies governing delay propagation across diverse airport tiers. Full article

Quinoa germ meal (QGM) is a protein-rich by-product with potential as an alternative protein source; however, its effects on growth performance and intestinal health in marine carnivorous fish remain unclear. Juvenile turbot (Scophthalmus maximus) were fed five isonitrogenous (45.6% crude protein) and isolipidic (9.8% crude lipid) diets for 8 weeks: a fishmeal-based control diet (C) and four experimental diets in which fishmeal was replaced with QGM at 10% (Q10), 20% (Q20), 30% (Q30), and 40% (Q40). Growth performance, muscle proximate composition, intestinal histomorphology, and intestinal transcriptomic profiles were analyzed. Growth performance parameters, including final body weight, weight gain rate, specific growth rate, daily feed intake, and condition factor, decreased significantly with increasing QGM inclusion levels compared with the control (p < 0.05). Feed conversion ratio increased significantly only when replacement exceeded 30% (p < 0.05), while survival rate was unaffected (p > 0.05). Muscle crude lipid content was significantly reduced in all QGM-fed groups (p < 0.05), whereas crude protein, moisture, and ash contents were unchanged. Intestinal mucosal fold height increased in the Q30 and Q40 groups, while submucosal width decreased in the Q40 group (p < 0.05). Transcriptomic analysis revealed a dose-dependent increase in differentially expressed genes, mainly enriched in ribosome-related pathways, linoleic acid metabolism, and protein digestion and absorption. High dietary inclusion of QGM (>30%) impaired growth performance in juvenile turbot, whereas low inclusion levels (≤20%) exerted minimal adverse effects. Quinoa germ meal represents a potential alternative protein source, yet its effective utilization requires further optimization to maintain growth performance. Full article

Pavement maintenance programs rely on timely and accurate crack assessment to preserve roadway quality and reduce long-term rehabilitation costs. Manual inspection remains the prevailing practice, yet it is slow, subjective, and exposes crews to safety risks. Automating crack detection under real-world roadway conditions remains challenging due to inconsistent lighting, shadows, stains, and surface textures that obscure distress features. This study examines the applicability of an integrated, vehicle-mounted framework for automated pavement crack segmentation and width-based severity estimation under practical roadway operating conditions. Data were collected from a moving vehicle using a custom camera–GPS system operating under diverse conditions, capturing the variability encountered in practical surveys. The proposed approach employs a state-of-the-art segmentation model and a calibrated width estimation tool that converts pixel-level crack measurements into physical units using a position-dependent regression model. The key contribution of this work is a unified segmentation and severity evaluation pipeline supported by a novel pixel-to-inch calibration surface and validated using images acquired during normal driving operations and manual field crack measurements. By combining advanced computer vision techniques with practical field-oriented data collection, the proposed system provides a deployable solution for roadway crack assessment, enabling safer, faster, and more scalable network-level pavement monitoring. Full article

The VDA 238-100 tight radius bend test has gained widespread acceptance for plane strain fracture characterization of sheet metals in proportional loading without necking. The VDA test features a 60 × 60 mm² square blank with a 0.2 mm or 0.4 mm radius punch to provide plane strain bending where the fracture limit of the material is lowest. However, the through-thickness gradients that suppress necking and promote fracture on the convex surface in tension can be exploited to efficiently characterize the fracture strain from uniaxial to plane strain tension by varying the sample width. In this study, V-bend tests were conducted for various sample widths for four advanced high-strength steels: 980GEN3, DP1180, MP800-V1, and MP800-V2 with the local fracture strains measured using digital image correlation. Reducing the width-to-thickness ratio below five altered the stress state at the failure location, with an aspect ratio of one providing edge fractures under uniaxial tension. This aspect ratio was then applied to 980GEN3 and MP800 steel samples with punched edges as it provides an efficient method for sheared edge fracture characterization that is not susceptible to necking as with common sheared edge tensile tests. To mitigate strain averaging inherent in DIC near surfaces, a geometric-based arc length methodology was proposed. The sheared edge fracture limits from the V-bend tests were then compared with the results from conical hole expansion and in-plane bend tests. The sheared edge formability was observed to have a material-dependent sensitivity to the test method. MP800-V2, with centerline segregation, exhibited a pronounced sensitivity to the applied deformation mode with absolute differences in fracture strains of 0.13 while the MP800-V1 and 980GEN3 did not. Full article

Velocity, pressure, and density fields computed in earlier three-dimensional direct numerical simulations of a statistically stationary, planar, one-dimensional, low-Mach-number hydrogen–air flame propagating in small-scale, moderately intense, spatially decaying turbulence are filtered out using top-hat filters of four different widths. Certain source/sink filtered terms in the transport equations for resolved and subfilter-scale kinetic energies are analyzed. These are (i) the rate of inertial transfer of kinetic energy between resolved and subfilter scales, (ii) baropycnal work, (iii) subfilter-scale velocity–pressure–gradient term, and (iv) subfilter-scale pressure–dilatation term. These filtered terms are averaged over transverse planes and time or conditioned to the filtered combustion progress variable. Results show that terms (i) and (ii) work to transfer kinetic energy from smaller to larger scales (backscatter) and from larger to smaller scales, respectively, with the baropycnal work dominating the former term. These trends are observed for mean and conditional terms. The mean velocity–pressure–gradient term is positive and works to increase subfilter-scale kinetic energy due to combustion-induced thermal expansion. The pressure–dilatation term changes its sign from negative to positive at the leading and trailing edges, respectively, of the turbulent flame brush. Under conditions of the present study, the magnitudes of the mean velocity–pressure–gradient and pressure–dilatation terms are smaller when compared to the baropycnal work. Probability Density Functions (PDFs) for the explored filtered terms exhibit long tails, are highly skewed, and are characterized by a large kurtosis, thus implying significant intermittency of inter-scale energy transfer and energy exchange between internal and kinetic energy in the flame. These PDFs indicate that the intermittency of the inter-scale energy transfer and energy exchange depends substantially on mechanisms and scales of energy injection. Full article

Sowing represents one of the most critical technological processes in grain production, where seed distribution uniformity directly impacts crop yield by determining plant nutrition area efficiency. Conventional sowing methods with varying row spacings often fail to ensure optimal area utilization. This study enhances subsoil-broadcast sowing quality through a novel trough-profile seed guide that ensures uniform seed distribution across the sweep opener’s working width. The research employed a combined methodology of theoretical analysis, DEM simulation, and experimental studies. Theoretical analysis demonstrated that sowing parameters depend mainly on seeder forward speed and the rotational speed of the seed-metering device’s rollers. DEM simulations visually confirmed the mechanism of ordered seed flow formation within the guide. Experiments simulated drill seeder operation, evaluating forward speed (1.2–2.4 m/s) and fluted roller rotational speed (20–25 rpm) effects on distribution uniformity and sowing instability. The results at 20 rpm with 2.0–3.0 grains per cell showed a standard deviation reaching 0.2–0.5 pcs. (CV: 13.0–24.2%). At 25 rpm, the deviation increased to 0.5–1.0 pcs. (CV: 18.2–39.4%). For total sowing instability at 20 rpm with 10.0–15.0 grains per opener, the standard deviation measured 0.3–3.3 pcs. (CV: 2.8–22.4%), while at 25 rpm, with 15.0–19.0 grains, values reached 0.5–3.9 pcs. (CV: 3.5–19.8%). All parameters conform to agrotechnical requirements, confirming solution effectiveness and addressing the literature gap in uniform seed distribution across the sweep opener’s working width. Full article

This study presents an integrated modeling and optimization framework for laser transmission welding (LTW) of transparent polymethyl methacrylate (PMMA) joints using single- and multi-core copper wires as energy absorbers. The highly nonlinear relationships between laser power, welding speed, and spot diameter and the resulting shear force and weld width were modeled using a hybrid neuro-regression strategy combining data-driven learning with physically interpretable analytical formulations. A wide range of candidate mathematical models were systematically evaluated based on training and testing performance, residual behavior, and physical consistency. The results demonstrate that models exhibiting near-perfect training accuracy frequently suffered from severe overfitting and poor generalization, whereas intermediate-complexity formulations provided a more reliable balance between accuracy and robustness. Comparative analysis further showed that multi-core absorbers consistently produced higher shear strength and more uniform weld seams than single-core configurations. The selected robust models were subsequently integrated into a two-level ensemble meta-optimization framework employing Differential Evolution, Nelder–Mead, Random Search, and Simulated Annealing algorithms under multiple design scenarios. The meta-optimization process successfully eliminated model- and algorithm-dependent extreme solutions and identified stable consensus parameter regions. For the multi-core system, an optimal combination of 30 W laser power, 20 mm/s welding speed, and 0.7 mm spot diameter was obtained, achieving improved mechanical performance while remaining within experimentally validated limits. The proposed framework provides a physically grounded and reliable strategy for surrogate-based optimization of nonlinear welding processes. Full article

This study evaluates 10 bar water aging effects on reciprocating tribology of FDM-printed PLA and PLA with 10 and 15 wt.% glass fiber (GF). Water uptake was Fickian, and saturation mass rose from 0.0845 g (PLA) to 0.1625 g and 0.295 g (10 and 15 wt.% GF). Reciprocating tests at 40 N over 100 m at 0.5 and 1 Hz showed immersion time drives coefficient of friction (COF) and wear. At 0.5 Hz, neat PLA stabilized at COF 0.65 to 0.70 but increased to about 0.75 to 0.80 after 7-day; PLA + 10 wt.% GF reached about 0.80 to 0.82 after 14-day to 28-day. GF reduced unaged wear depth from about 125 µm to about 85 to 96 µm, yet 28-day aging increased depths to about 129 to 132 µm for both GF levels at 0.5 Hz. At 1 Hz, neat PLA peaked at about 235 to 240 µm depth after 7-day, whereas 15 wt.% GF reached about 160 µm after 28-day. Factorial analysis showed that wear scar width was primarily influenced by immersion time, accounting for 76.02% of the variation in the data, clearly evidencing strong dependence on the environment. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), glass transition temperature (Tg), and the melting temperature (Tm) support the occurrence of a transition from volume to interface-dominated damage with aging, while Tg and Tm remain unaffected. Full article

This study investigates the flow and heat transfer mechanisms of high-temperature air flowing across staggered lined fine tubes in a SABRE-type precooler. Large-Eddy Simulation (LES) was employed to model three-dimensional unsteady flow under constant-property and variable-property air models at inlet temperatures of 400–800 K. The results show that increasing temperature substantially enhances vorticity, turbulent kinetic energy, heat flux, and Nusselt number, while flow separation and pressure drop are intensified. However, when temperature-dependent air properties are incorporated, the wake width increases and the separated shear layers become thicker, while the turbulence/unsteadiness intensity decreases. Consequently, the near-wall shear is reduced and the heat transfer coefficients are lower. Compared with variable-property predictions, constant-property models overestimate the average Nusselt number by 20–40% and the local pressure drop by 40–65%, and they underestimate the air-side temperature drop along the tube rows. These findings demonstrate that real-gas effects significantly alter both aerodynamic resistance and thermal performance. Overall, accurate representation of temperature-dependent air properties is essential for the reliable design, evaluation, and optimization of micro-tube precoolers. Full article

Electric Water Pumps (EWPs) are being adopted more widely to improve thermal management in internal combustion engines and electrified powertrain systems. In this context, the drive motor must deliver high efficiency and reliability despite a strict volume constraint. This paper addresses a key drawback of coreless printed circuit board (PCB) stator axial-flux permanent-magnet machines for EWP use: the PCB traces are directly exposed to the magnet flux, which increases AC loss, while the required phase resistance also leads to non-negligible DC copper loss. To mitigate both loss components within the same conductor design space, a pyramid trace concept is introduced. A magnetic equivalent circuit (MEC) based model is first used to estimate the baseline performance as the number of PCB stator modules changes, and the resulting scalability is examined in terms of module commonality. The final design then applies the pyramid trace layout with a layer-dependent trace width that is narrower on the layers closer to the magnets and wider on the layers farther away—the trade-off between AC loss and DC loss is optimized using 3D finite element analysis. Torque predictions from the simplified MEC model are cross-checked against 3D finite element analysis (FEA), and finally, a prototype is built to validate the analysis with experimental measurements; for the final selected model, the torque prediction error is 2.37% compared with the validation result. Full article

Background/Objectives: Facial and intraoral parameters are important guidelines in prosthetic planning and rehabilitation. This study aimed to analyze and determine the relationship between facial parameters and measurements on the upper anterior teeth using digital photography of the participants. Methods: This cross-sectional observational study included 82 student participants. Digital images (front facial and dental view) were taken of each participant, and then standardized images were used to measure facial and dental parameters. Results: The width of the maxillary anterior teeth and facial parameters were greater in males than in females, except for the medial canthus of the eye, which was slightly larger in females. A significant positive correlation was found between all facial parameters and the widths of the central and lateral incisors, as well as their combined sum. The strongest correlation was observed between the lateral canthus of the eye and the total width of the maxillary anterior teeth (r = 0.546; p < 0.001). In regression analysis, it was shown that the bizygomatic width had a statistically significant contribution to the prediction of the central incisor width (p = 0.045). It was also shown that the intraoral parameters, such as the height of the interdental papilla and interpapillary angle, are shape-dependent. Interincisal angles between the central incisors in all participants are significantly lower (p < 0.05) than the angles between incisal edges in other anterior teeth. Conclusions: Facial parameters cannot be used independently to predict dental parameters; nevertheless, when integrated with basic esthetic principles, they provide complementary information relevant to analytical procedures in restorative and prosthetic dentistry. Full article