Search Results (1,473)

In padel, an emerging racket sport, evidence regarding competition demands in adolescent players remains limited. Therefore, this study aimed to analyze absolute external load during official competition in male and female U18 padel players. A total of 18 official matches from the Spanish Championship of Regional Teams were analyzed. Eighteen U18 players (9 females: age 15.1 ± 1.5 years, height 162.9 ± 8.2 cm, body mass 54.6 ± 9.1 kg; 9 males: age 15.4 ± 1.8 years, height 175.1 ± 9.4 cm, body mass 67.2 ± 11.0 kg), competing at the regional and national levels, were monitored using OLIVER™ inertial devices. External load variables included playing time, total distance, high-intensity accelerations and decelerations, changes of direction, time spent at high metabolic power, session volume, session intensity, and maximum speed. Statistical analysis was performed using linear mixed models to compare differences between sexes. Male players showed significantly higher values than female players in playing time (82.34 ± 23.95 vs. 51.03 ± 12.39 min; p < 0.001) and total distance (3958.50 ± 242.57 vs. 2225.54 ± 257.29 m; p < 0.001). They also presented significantly greater values in high-intensity external load variables, including accelerations, decelerations, changes of direction, time spent at high metabolic power, session volume, and session intensity (all p ≤ 0.009). No significant differences were found for maximum speed (p = 0.074). These findings suggest that official competition demands differ according to sex in U18 padel and may help inform more specific training prescriptions and load-monitoring strategies. Full article

Detecting the presence of carbonation is critical for monitoring structural safety and durability. Identifying the presence of carbonation reveals the risk of chemical changes within the concrete and the potential for reinforcement corrosion. This detection allows for a reliable and prioritized assessment of the structure’s current condition. Therefore, checking for the presence or absence of carbonation is a critical indicator in determining structural safety and maintenance priorities. This study explicitly addresses a critical gap in the literature, where existing carbonation research predominantly focuses on regression-based estimation of carbonation depth, while the problem of direct visual classification of carbonation presence for rapid decision-making currently remains underexplored. In this context, the study aims to fill this research gap through developing a robust and field-applicable deep learning-based classification framework for the automated detection of carbonation presence on concrete surfaces using images, while systematically comparing the performance of different YOLO architectures and assessing the suitability of a previously unused dataset (ConcreteCARB) for carbonation classification tasks. In this context, YOLOv8m, YOLOv11m, YOLOv12m, and YOLOv26m were compared for concrete carbonation classification, aiming to find the most suitable model. The results show that YOLOv8m and YOLOv11m achieve perfect accuracy (Accuracy = 0.9981, Precision = 1, Recall = 0.9964, Specificity = 1, AUC-ROC = 1). In inference efficiency analyses, the YOLOv11m model was identified as the fastest model with the lowest latency and highest FPS. While YOLOv8m and YOLOv26m offered balanced speed-performance results, YOLOv12m showed a relatively lower processing speed. The findings indicate that YOLOv11m is the most suitable option for real-time applications. Full article

Introduction: Vertical jump performance is linked to key performance indicators in rugby, including tackling success and ruck involvement. Although plyometric jump training (PJT) is known to enhance explosive qualities in various sports, its specific effects in rugby remain unclear. Objective: To synthesise evidence on the effects of PJT on vertical jump ability and other physical fitness components in adult rugby players. Methods: A systematic review was conducted in accordance with PRISMA 2020 guidelines. PubMed, EBSCO (SPORTDiscus), WoS, and Scopus were searched up to December 2025. Experimental and quasi-experimental studies involving rugby players undertaking PJT programmes of at least two weeks, with at least one vertical jump outcome, were included. Two reviewers independently performed study selection and data extraction. Risk of bias was assessed using the RoB 2.0 tool. Results: Seven studies involving 178 male players were included. PJT improved sprint speed, change of direction, anaerobic power, reactive strength, lower-limb stiffness, and isometric plantar flexion strength. Gains in countermovement jump power were noted in some conditions, such as training on softer surfaces. However, improvements in jump height were inconsistent. Conclusion: PJT enhances several important physical qualities in rugby players but shows variable effects on vertical jump height. Further high-quality research is needed. Full article

Buried natural gas pipeline leakage poses significant risks to public safety and environmental sustainability. A three-dimensional transient computational fluid dynamics model is established to investigate gas leakage and diffusion behavior, with a focus on quantifying the differences between standalone soil models and soil–atmosphere-coupled models. First danger time (FDT), farthest danger range (FDR), and ground danger range (GDR) are adopted as standardized safety metrics that translate complex concentration fields into actionable emergency response parameters. Simulation results indicate that the coupled model predicts an FDT 4.9% earlier and a GDR 39.7% smaller than the standalone soil model under no-wind conditions, highlighting the necessity of coupling. Increasing temperature reduces leakage mass flow rate by 8.4% but produces only marginal changes in FDT (6.01–6.47 s) and GDR (1.888–1.973 m) across the −10 °C to 40 °C envelope. Wind speed exhibits a non-monotonic, time-dependent effect: the shortest FDT occurs at 5 m/s (5.71 s), while the worst-case spatial hazard occurs at 2 m/s (FDR = 3.423 m at 60 s, 3.304 m at 100 s). A crosswind configuration reduces GDR by merely 1.6% when compared with an along-wind configuration, indicating weak directional sensitivity. Topography dominates hazard onset timing: a canyon shortens FDT to 0.33 s, while a hill delays it to 18.48 s—a 43-fold span. Offset obstacles with upwind configuration maximize FDT delay to 8.07 s (+30.6%) while enabling late-stage wake-driven GDR expansion. These findings provide quantitative guidance for risk assessment, emergency response, and monitoring layout of buried natural gas pipelines. Full article

Recycling end-of-life (EoL) photovoltaic (PV) modules is essential for resource recovery and pollution mitigation, yet weak incentives and non-standardized treatment continue to hinder the development of formal recycling systems. This paper develops a tripartite evolutionary game model involving the government, PV power generators, and third-party recyclers under a reward–penalty policy mechanism. Replicator dynamic equations, Jacobian stability analysis, and MATLAB R2023b (MathWorks, Natick, MA, USA) simulations are used to examine strategic interactions and evolutionary paths. The results show that: (1) under the baseline parameter setting, the system converges to a unique evolutionary stable strategy, (0, 1, 1), namely no government regulation, generator recycling, and recycler green technology innovation; (2) variations in initial strategy probabilities affect convergence speed but do not change the final equilibrium; (3) under the same total reward expenditure, increasing rewards to generators drives the system toward the desirable equilibrium faster than allocating the same amount mainly to recyclers; and (4) penalty policies also promote compliance, but their marginal effect is weaker than that of reward-based incentives. These findings suggest that appropriately designed incentives can accelerate generator recycling and recycler green innovation, while the government’s role may gradually shift from direct intervention to supervision and coordination. Full article

Selective laser melting (SLM) offers significant potential for fabricating lightweight 316L stainless steel lattice structures (LSs), while forming defects and microstructural heterogeneity remain challenging, especially in fine struts. In this study, response surface methodology (RSM) and analysis of variance (ANOVA) were employed to quantify the coupled effects of geometric parameters (forming angle, FA; rod diameter, RD) and processing parameters (laser power, LP; scanning speed, SS; hatch spacing, HS) on the mass deviation (MD) of fine struts. The results show that FA and RD are the dominant factors affecting MD within the investigated parameter range, whereas LP and SS exhibit comparatively weaker effects. Representative samples with different FA and RD were further characterized by SEM, XRD, and EBSD to examine the associated microstructural evolution. The observations indicate that changes in FA and RD are accompanied by variations in solidification morphology, defect distribution, crystallographic texture, and GND density. Higher FA is associated with lower MD and stronger texture alignment along the building direction, whereas larger RD tends to promote columnar growth and enhanced texture intensity. These results suggest that geometric parameters can serve as effective design variables for tailoring forming deviation and representative microstructural characteristics of fine struts in SLM-fabricated 316L lattice structures. Full article

Automated Speed Enforcement (ASE), a widely known speed management strategy, extends beyond its safety benefits and is shaped by public trust, broader governance, and policy frameworks. This study evaluated public opinions of the ASE program in school zones in Georgia, United States, which has recently undergone multiple policy changes. An online survey was conducted targeting Georgia drivers aged 18 years or older, which gathered 502 responses from a representative sample based on exposure, direct school connections, and sociodemographic factors. Respondents indicated their agreement levels on a Likert scale across multiple statements about ASE and their thoughts on enhancing the program’s transparency, trustworthiness, and fairness. Data analysis was conducted using descriptive statistical techniques and cross-classification. Among all respondents, 71 percent supported the program, and among individuals who had driven through speed-enforced school zones, 81 percent reported that ASE led them to reduce speeds. Issuing the citation to the actual driver at the time of violation, publicizing revenue allocation and utilization, publicizing safety benefits, and clearly posting the speed limits and the hours under evaluation were among the key concerns. These findings highlight the significance of integrating public perceptions into ASE policy, identifying areas needing improvement, and promoting community-endorsed traffic safety interventions. Full article

Background: Adolescent idiopathic scoliosis (AIS) alters postural control and movement coordination. This study investigated the dynamic biomechanical effects of Schroth therapy on AIS kinematics. Methods: Twelve young individuals with AIS completed a standardized Schroth therapy program, while twelve healthy participants served as controls. Three-dimensional gait kinematics were recorded using the Xsens MVN Awinda during walking at a self-selected speed. Pre- and post-intervention assessments were conducted for the analysis of trunk, pelvic, and lower-extremity kinematics. Results: Changes were observed primarily in proximal kinematic parameters. Pelvic obliquity and thorax–head flexion/extension demonstrated the largest differences (p = 0.004 and p = 0.002, respectively; Cohen’s d = 0.82–0.95). Moderate changes were detected in pelvis–thorax axial rotation and shoulder abduction/adduction patterns. Lower-extremity changes were limited and parameter-specific, with moderate changes observed in selected hip and knee rotational parameters, while other variables showed minimal or no change. Post-intervention comparisons with healthy controls showed that several upper-body kinematic patterns showed patterns that were more alike to those observed in the control group, although direct equivalence cannot be assumed. Conclusions: The findings suggest that Schroth therapy may be associated with changes in trunk and pelvic kinematics during gait in individuals with AIS. Full article

Objective: This study compared the acute effects of caffeine capsule ingestion and caffeine mouth rinsing on physical performance and volleyball-specific skills at different times of day in trained adolescent male volleyball players. Methods: Twenty-four well-trained male volleyball players (age: 16.9 ± 0.7 years) completed a randomized, double-blind, placebo-controlled crossover study involving three supplementation conditions, caffeine capsule (CAFcap, 3 mg·kg⁻¹), caffeine mouth rinse (CAFrinse, 3 mg·kg⁻¹), and placebo (PLA), administered via a double-dummy procedure (nine sessions per participant: 3 conditions × 3 times of day) at 08:00, 12:00, and 18:00. Participants completed squat jump (SJ), countermovement jump (CMJ), block jump, attack jump, 10 × 10 m t-test, spike accuracy, and serve accuracy assessments. Data were analyzed using two-way repeated-measures ANOVA. Results: Significant main effects of condition and time of day were observed for all outcomes. Significant condition × time-of-day interactions were found for SJ, CMJ, attack jump, and change-of-direction speed, indicating that caffeine-related ergogenic effects were most evident in the morning and at midday, whereas these benefits were attenuated in the evening when baseline performance was highest. At 08:00 and 12:00, both CAFcap and CAFrinse improved jump performance and agility compared with PLA, with capsule ingestion showing a small-to-moderate advantage over mouth rinsing for selected lower-limb power outcomes at midday (mean difference range: 0.51–0.57 cm; dz = 0.57–0.65). For block jump, spike accuracy, and serve accuracy, both caffeine conditions improved performance relative to placebo, while a progressive improvement across the day was observed under all conditions, including placebo, confirming a diurnal rhythm effect independent of supplementation. Overall, the data indicate that caffeine partially reduced the amplitude of diurnal variation in several physical performance measures. Conclusions: Both caffeine capsule ingestion and caffeine mouth rinsing enhanced physical and volleyball-specific performance in trained adolescent male volleyball players. The ergogenic effects were more pronounced earlier in the day, suggesting that caffeine may be particularly useful for attenuating morning and midday performance decrements, while mouth rinsing represents a practical non-ingestive alternative with meaningful efficacy. Full article

During the worldwide energy transition, wind power has become a leading development direction. Compared to large-scale horizontal-axis wind turbines (HAWTs), small-scale vertical-axis wind turbines (VAWTs) show potential, lack yaw mechanisms, adapt to wind direction changes, and are cost-effective. However, small-scale VAWTs operate in the near-surface atmospheric boundary layer and are sensitive to low-temperature and high-humidity climates, which cause blade icing. Ice buildup leads to fluctuations in aerodynamic loads, reduces power output, and diminishes stability. This study focuses on the NACA-0018 airfoil, using a low-temperature wind tunnel platform to simulate freezing durations to obtain ice characteristics on the blade surface. Based on ice profiles, numerical models were developed. Computational fluid dynamics (CFD) techniques were used to perform unsteady simulations of aerodynamic performance at various icing durations, investigating the influence on the power coefficient. The results indicate that the effect of icing duration on the average power coefficient depends on TSR. At the 5 min icing stage, the optimal tip-speed ratio decreases. Icing deteriorates aerodynamic performance at high tip-speed ratios, while producing positive optimization effects at low tip-speed ratios. This paper reveals the variation patterns of aerodynamic performance and differentiated mechanisms during the icing process of small vertical-axis wind turbine blades, providing a theoretical basis and data support for the development of surface anti-icing technologies and safe, efficient operation in low-temperature environments. Full article

Background: Wearable powered gait orthoses offer a clinically flexible alternative to treadmill-based robotic systems, yet evidence on different device configurations matched to the site of neuromuscular impairment remains limited. Methods: In this multicenter prospective pilot study, 75 participants with neurological gait impairment were allocated to a hip orthosis (HO; n = 39) or a knee–ankle–foot orthosis (KAFO; n = 36) group based on clinical assessment of predominant gait pattern. Both groups completed six overground gait-training sessions over three weeks. Primary outcomes were the Six-Minute Walk Test (6MWT) and Ten-Meter Walk Test (10MWT), assessed without (WO) and with (WITH) the device. Secondary outcomes were the Berg Balance Scale (BBS), Timed Up and Go Test (TUG), and Dynamic Gait Index (DGI), all assessed without the device. Wilcoxon signed-rank tests were used for pre-to-post comparisons. Results: Both groups demonstrated significant improvements in primary walking outcomes, with consistent gains in unassisted (WO) 6MWT and 10MWT performance across groups and in device-assisted (WITH) 10MWT speed; the one exception was a small statistically significant but clinically negligible decrease in device-assisted 6MWT in the KAFO group (−4.1 m, below established MCID). In the KAFO group, BBS improved by a median of 5.5 points (43.5 to 49.0, p = 0.0005), TUG decreased by 5.1 s (p < 0.001), and DGI improved by 6.0 points (p = 0.002); all three changes exceeded published minimum detectable change thresholds. In the HO group, pre-to-post differences in BBS (+1.0), TUG (+0.8 s; an unfavorable direction), and DGI (−2.0; an unfavorable direction) were statistically detectable but small in absolute magnitude, fell at or below published thresholds for minimum detectable change, and should not be interpreted as clinically meaningful improvement. The WO-WITH performance gap in the KAFO group narrowed substantially after training, with 10MWT time no longer differing significantly between conditions at post-training (p = 0.116). Conclusions: Six sessions of gait pattern-matched powered gait orthosis training produced clinically meaningful within-group improvements in walking outcomes in both groups. In the KAFO group, balance and functional mobility outcomes also showed clinically meaningful improvements; in the HO group, balance and functional mobility outcomes showed only statistically detectable but clinically non-meaningful fluctuations around near-ceiling baseline scores. Walking benefits generalized to unassisted ambulation in both groups. These findings support the feasibility of an individualized orthosis prescription framework and provide a basis for future randomized controlled trials. Full article

Aiming at the dual dilemma in high-resolution cropland change detection, where CNNs are constrained by limited local receptive fields and Transformers suffer from heavy computational costs, we propose LiteScan-Net, a lightweight and robust network architecture incorporating scanning principles from state-space modeling. The network innovatively introduces the Multi-Directional Global Scanning (MDGS) mechanism as an efficient engineering surrogate, which simulates the selective scanning process using large-kernel 1D convolutions. This achieves global context modeling with linear complexity while avoiding the hardware limitations imposed by recurrent computations. Based on this mechanism, a three-stage collaborative architecture is constructed: the Coordinate-Aware Feature Purification (CAFP) module is designed to mitigate shallow phenological noise via coordinate sensitivity; the Context Difference Verification (CDV) module aims to alleviate pseudo-changes caused by registration errors through global alignment; and the State-Space Guided Refinement (SSGR) module promotes the generation of change masks with precise boundaries and compact interiors. To verify the model generalization, we construct a Massive Specialized Cropland Change Detection dataset named MSCC, which exhibits significant cross-scale characteristics. Experimental results demonstrate that LiteScan-Net achieves state-of-the-art (SOTA) performance across the CLCD, Hi-CNA, and MSCC datasets, with F1-scores of 79.43%, 84.82%, and 89.62%, respectively. With a low computational cost of only 1.78 GFLOPs and a real-time inference speed of 37.9 FPS, LiteScan-Net demonstrates high potential for future deployment on resource-constrained edge devices. Full article

Understanding rate of change requires reasoning about measurable quantities and how one quantity changes relative to another. To support this kind of reasoning, teachers should develop the ability to notice students’ quantitative and covariational reasoning. This study examines how preservice teachers (PSTs) attend to, interpret, and respond to students’ quantitative and covariational reasoning in video-based analyses of water-filling rate-of-change tasks. Drawing on relevant research, professional noticing is examined through the lenses of quantitative reasoning and covariational reasoning. Using a design-based qualitative approach, secondary PSTs participated in structured analyses of students’ problem-solving discussions related to rate of change. Data were collected across eight semi-structured sessions. This study reports qualitative analyses from two sessions (Sessions 1 and 2) that focused on rate of change. Findings show that PSTs’ initial attending shifted from perceptual task features (e.g., pouring speed, references to time) toward identification of measurable quantities, recognition of coordination between height and volume, and comparison of equal volume increments. PSTs’ interpretations progressed from recognizing secondary-variable coordination to identifying direct covariation, and their instructional responses became more targeted and content-specific. However, challenges persisted in interpreting students’ informal and visually mediated covariational reasoning. This study contributes to research on professional noticing by integrating quantitative and covariational reasoning as analytic lenses and highlighting implications for teacher preparation in calculus education. Full article

The Kangaroo Escape Optimizer (KEO) is a recently proposed biomimetic metaheuristic inspired by the adaptive escape strategies of kangaroos in predator–prey interactions. Although effective, KEO-like algorithms based on many populations may suffer from premature convergence and loss of population diversity when addressing complex, multimodal, and constrained optimization problems. This paper proposes an Enhanced Kangaroo Escape Optimizer (EKEO) that integrates Differential Evolution Mutation (DEM) and Quasi-Oppositional Learning (QOL) to address fundamental limitations in exploration–exploitation balance. From a biomimetic perspective, DEM mimics the refined high-frequency muscular adjustments of a kangaroo during close-range evasion, enabling local refinement around promising solutions, while QOL emulates the animal’s sudden directional changes and scanning behavior to preserve population diversity and escape local optima. Their principled integration yields a robust optimization framework that consistently outperforms state-of-the-art and classical metaheuristics across benchmark functions and real-world engineering problems. The findings suggest a generalizable design principle for biomimetic hybrid metaheuristics, demonstrating that coupling directed exploitation with diversity-preserving exploration leads to reliable high-performance optimization. The performance of EKEO is rigorously evaluated in two phases. First, its optimization accuracy and convergence speed are benchmarked against 11 state-of-the-art and classical metaheuristics on 23 classical benchmark functions and the CEC 2019 test suite. Second, its practical applicability and constraint-handling effectiveness are validated on four real-world engineering design problems: step-cone pulley, gear system, tubular column, and pressure vessel design. The experimental results are supported by comprehensive statistical analyses (including Wilcoxon rank-sum tests) and convergence curves, showing that EKEO consistently outperforms its competitors in solution quality, convergence speed, and robustness. These findings establish EKEO as a competitive, reliable, and versatile biomimetic optimization tool suitable for solving complex continuous and constrained engineering optimization problems. Full article

This study investigates methane leakage and diffusion from a buried high-pressure natural gas pipeline (8 MPa, 1000 mm diameter) using CFD simulations with the DES turbulence model. Based on homogeneous and layered soil models, the influences of soil porosity (0.46 to 0.54), particle size (10 μm to 100 μm), and soil stratification on the spatial and temporal characteristics of methane diffusion are systematically explored. The simulation results show that (1) methane diffuses from the leak hole to the surrounding soil in an ellipsoidal pattern, with the fastest diffusion speed along the pipeline’s axial direction. (2) In homogeneous soil, within the range of soil parameter values considered in this study, the absolute changes in risk assessment indices (FDR, GDR) caused by soil particle size were more significant; whereas the relative percentage changes in risk assessment indicators caused by soil porosity were more pronounced. (3) In layered soil, the permeability contrast between adjacent layers creates the permeability discontinuity interface effect. When a fine-grained or low-porosity layer overlies a coarse-grained layer, the upper layer acts as a hydraulic barrier, prolonging FDT from 130 s to 354 s while promoting significant horizontal spread at the interface. Conversely, a coarse-grained or high-porosity upper layer accelerates vertical breakthrough. These findings provide a scientific basis for risk assessment, monitoring site optimization, and emergency response planning, particularly in regions with heterogeneous stratified soils. Full article