Search Results (441)

The crashworthiness of stiffened hull plates is essential for improving ship safety under collision and grounding loads. In this study, the impact resistance and energy-absorption mechanism of a U-shaped stiffened hull plate subjected to a wedge-shaped impact are investigated through drop-weight tests, nonlinear finite-element simulations, and analytical derivations. The experimental results show that the specimen experiences local indentation of the face plate, folding of the U-shaped stiffener webs, and crack propagation along the stiffener direction. The maximum residual deformation reaches 112 mm, and the failure mode is governed by the combined effect of face-plate stretching, web folding, and tearing near the contact or welded region. A finite-element model is established in ABAQUS and validated against the experimental deformation mode and force–indentation response. Furthermore, an analytical model based on the plastic upper-bound theorem is proposed to predict the instantaneous structural resistance. The total resistance is decomposed into contributions from the face plate, inclined webs, cap plate, and the tearing correction term. The analytical prediction agrees reasonably with the experimental and numerical results, with a peak collision force of approximately 620 kN at an indentation depth of about 124.5 mm. The proposed method provides a practical reference for rapid resistance prediction and crashworthy design of U-shaped stiffened hull plates. Full article

Single-electron capture in the collisions of carbon ions, ${\mathrm{C}}^{q+}$ (q = 1–6), with water molecules is theoretically investigated using the continuum distorted wave-eikonal initial state (CDW-EIS) formalism. The projectile–electron interaction is modeled using three different approaches to account for screening effects: (i) the Green–Sellin–Zachor (GSZ) potential, which combines long-range Coulomb and short-range screening terms; (ii) a modified GSZ-$Z_P^r$ variant employing an effective radius-dependent nuclear charge; and (iii) the binding energy screening (BES) approximation, which treats the projectile as a rigid Coulomb core. Total cross-sections for single-electron capture are computed over the energy range of 40 keV/u to 10 MeV/u. A detailed analysis is presented as a function of the initial molecular orbital, the final bound state of the captured electron, and the projectile charge state q. The results reveal strong dependencies on orbital binding energies and the degree of projectile ionization. Additionally, of radiobiological interest, the average binding energy for the different projectiles are computed using the presented cross-sections and reported. Full article

Public discussion in Australia often presents pet cats as a major cause of wildlife decline, and cat management is frequently promoted as a major conservation response. However, this focus may draw attention away from other common and preventable recorded causes of threatened species rescue. Using the NSW Wildlife Rehabilitation Data Dashboard, we present the first statewide analysis of NSW wildlife rehabilitation records to specifically examine threatened species, rather than pooling threatened and non-threatened wildlife together. This dataset represented 52,475 individuals and 158 threatened species rescued from 2013 to 2024 in NSW. Rehabilitation data represent only animals that are found, reported, and brought into care, mostly in human-frequented environments, and should not be interpreted as estimates of total wildlife mortality, predation pressure, or ecological impact beyond the rehabilitation dataset. Outcomes were often poor: 24.1% were released, 58.5% died, and 17.5% had other recorded outcomes. The largest recorded category was Unknown (21.9%), which should not be interpreted as absence of cause, but as cases where a specific cause could not be assigned at the time of reporting to the dashboard. Among identified recorded causes, the most common were Entanglement (11.6%), Weather Event (11.4%), Abandoned/Orphaned (10.1%), Unsuitable Environment (7.3%), and Motor-Vehicle Collision (5.8%). Together, Unknown and these five identified causes accounted for 68.1% of recorded threatened species rescues. By comparison, all animal attacks combined accounted for 4.4%; dog-related rescues were more than three times as frequent as cat-related rescues, with cat-related rescues comprising 0.6%. These findings show that cat attacks formed a small proportion of recorded rescues, although overall ecological impact cannot be determined from these data. Prevention efforts targeting common and preventable recorded causes may help reduce the number of threatened animals entering care. Full article

Circulating tumor cells (CTCs) are tumor cells that break away from the origin tumors and disseminate in the bloodstream and lymphatic circulation systems. CTCs originate from the original tumor with a similar bimolecular source. This makes CTCs play a vital status in cancer prognosis and diagnosis. However, CTC separation is highly challenging due to rarity and heterogeneity. In the present work, we designed a double-array petal flower-shaped microfluidic chip, a multifunctional capturing and isolation chip combining affinity and physical properties. The chip is composed of three arrays of microfluidic barriers organized one after the other. For the first array, six convex structures are set in each narrow channel. The first structure has a total of 12 such channels, which can increase collision frequency between cancer cells and convex structures in the channel. The second capture structure is one composed of an S-shaped array of concave triangle microcolumns and parabolic circular microcolumns. The advantage of this setting is that it can capture CTCs in the blood flowing into the first structure in 12 directions from multiple angles and multiple times, so as to improve capture efficiency. The third capture structure is composed of elliptical microposts and cylinders. The treated blood is captured for the last time. Because of the round or elliptical shape, it can retain the cell viability to a great extent, which is convenient for later pathological analysis of tumor cells. Simulation of velocity influence, pressure effects, streamline tendency, and shear rates is carried out for each structure. Therefore, theoretical validation has been illustrated to achieve high capture rate and purity. These delicate designs and numerical analysis clarify feasibility for further experiments of CTC enumeration, clinical analysis, and evaluation of cancer therapy. Full article

Against the backdrop of the advancing Transportation Power Strategy, long and large tunnels face critical challenges in ensuring the safety and efficiency of transportation scheduling due to their harsh environment, complex traffic network, and the need for coordination among multiple types of vehicles. Addressing the shortcomings of existing research—such as the disconnection between path planning and dynamic environments, insufficient coordination between timetables and paths, and incomplete conflict management—this paper constructs a comprehensive optimization model for the scheduling of construction vehicles in tunnel traffic networks. Firstly, integrating the improved social force model with the BPR function, an adaptive social force-BPR path planning model with a collision compensation mechanism is proposed, and the weights of sub-items are optimized using the improved AHP algorithm. Secondly, a constraint system covering paths, spatio-temporal logic, and three types of conflicts (crossing conflicts, head-on conflicts, and congestion conflicts) is established, and a bi-objective function of “minimum total scheduling time” and “minimum number of conflicts” is designed. Combined with the improved NSGA-II algorithm, the collaborative optimization of departure intervals and paths is realized. In particular, a conflict entropy repair operator is introduced to quantify the conflict chaos through node conflict entropy and vehicle conflict entropy, and the scheduling strategy is accurately adjusted based on the logic of “priority ranking-dynamic delay” to balance conflict resolution and efficiency loss. Finally, a case verification is carried out relying on a tunnel topological network with 30 nodes and 41 edges. The experimental results show that the optimal repulsion coefficient k_f of the social force model is 20, and the maximum departure interval of 8 min is the best configuration after introducing the repair operator. At this time, the total scheduling time is 136 min, and the total number of conflicts is only 2, completely avoiding high-risk head-on conflicts and congestion conflicts. The research outputs a vehicle scheduling scheme, enriches the theory of tunnel traffic scheduling, and provides scientific and feasible technical support for the coordinated scheduling of construction vehicles in long and large tunnels. Full article

To address the problems of closed-loop task organization, strong corridor constraints, and path failure after local disturbances in unmanned aerial vehicle (UAV) inspection of gas-insulated switchgear (GIS) rooms, this paper proposes a topology-and-corridor-guided bias-suppressed D* (TCG-BS-D*) method for closed-loop three-dimensional (3D) path planning and local replanning. The proposed method constructs a structured guidance model based on the inspection-corridor topology, generates local 3D path segments according to a predetermined inspection sequence, and forms a nominal closed-loop inspection path through bias suppression and path regularization. Meanwhile, for local maintenance blockage and dynamic disturbance scenarios, an alternative local replanning strategy is applied to the affected path segments. Simulation results show that, under the static closed-loop inspection condition, the proposed method achieves a total path length of 700.22 m, a total inspection time of 269.32 s, an average safety clearance of 8.18 m, 37 large-angle turns, a corridor adherence rate of 80.73%, and a task completion rate of 100%, showing superior performance in inspection efficiency, safety margin, trajectory regularity, and corridor consistency. Under the local blockage condition, the replanned path introduces path-length and time increments of 71.29 m and 25.88 s, respectively, while maintaining the minimum safety clearance at 1.52 m and increasing the corridor adherence rate to 83.91%. Under dynamic disturbance conditions, the minimum dynamic safety clearance is improved from −2.71 m to 17.84 m, effectively eliminating the local dynamic collision risk. The results demonstrate that the proposed method can balance closed-loop path-generation efficiency, corridor-structure consistency, safety margin, and adaptability to local disturbances, providing an effective solution for UAV inspection path planning in GIS rooms. Full article

Introduction: Pedestrians lying on the road—collapsed through medical emergency, intoxication, or displacement following a prior collision—represent a disproportionately lethal and underaddressed category in road traffic safety. Forensic database analyses derived from Japan’s national police records document a fatality rate of 33.0% for collisions involving pedestrians lying on the road, more than double the rate for upright pedestrian collisions. Standard Advanced Driver-Assistance Systems (ADAS) yield a True Positive Rate (TPR) of only 21.4% for detecting pedestrians lying on the road under night conditions—a classification gap of 73.3 percentage points. Methods: In simulation trials, we evaluated the Advanced Falling Object Detection System (AFODS—where “falling object” denotes the low-profile human form at road level, distinguishing the prone pedestrian from the upright postures addressed by conventional ADAS) on a composite dataset of 3200 annotated fall events and 12,000 negative samples (training/validation), with 320 independent controlled simulation trials used for performance evaluation, spanning real-world, forensic-reconstruction, and Total Human Body Model for Safety (THUMS)-validated synthetic scenarios. No physical prototype has been evaluated; all performance data are derived from simulation, and 37.5% of positive samples are synthetically generated. These simulation conditions represent a first feasibility demonstration pending real-world hardware validation. This paper introduces three original contributions absent from prior work: a three-stage quantitative injury-risk model, a formal ISO 26262 Hazard Analysis and Risk Assessment (HARA), and a medicolegal SHAP interpretability framework. The injury-risk model translated detection latency via impact velocity to Head Injury Criterion (HIC) and estimated fatal injury probability (AIS ≥ 5); these model outputs should be interpreted as exploratory estimates pending ATD validation. Reporting follows principles consistent with the TRIPOD statement. Results: Under clear daytime conditions, AFODS demonstrated a TPR of 98.2% (95% CI: 97.4–98.8%) in simulation, decreasing to 95.6% under night dry-road conditions and 89.4% under night rain. The system achieved an AUC of 0.981 and a mean end-to-end latency of 46.5 ms, representing a 76.8 percentage-point improvement in simulation over the monocular RGB baseline (p < 0.001). The injury-risk model projects a reduction in estimated fatal head injury probability from 66.2% (Monte Carlo mean) (no detection, 50 km/h full-speed impact) to 0.7% under AFODS worst-case night/rain conditions, and to ≈0% under clear daytime simulation conditions. Conclusions: A 73.3 percentage-point classification gap places pedestrians lying on the road outside the effective detection envelope of current ADAS, compounded by the systematic exclusion of non-upright postures from regulatory test protocols and benchmark datasets. AFODS supports proof-of-concept feasibility under simulation conditions. Three translational steps are required: prototype validation on real-world hardware using instrumented Anthropomorphic Test Devices (ATDs); prone-posture biomechanical injury modelling using HIC and BrIC criteria; and regulatory extension of pedestrian AEB test standards to non-upright scenarios. Full article

Background Although cycling has definite health benefits, it is certainly not a risk-free activity; its increasing use is associated with a rise in accidents. This study aims to characterize cycling injuries and their associated factors in a tertiary trauma center, including injury severity, accident circumstances, and in-hospital costs. Methods: A retrospective observational study was conducted on patients over 15 years of age hospitalized after a cycling accident. Collected variables included the characteristics of the accident, the epidemiology of musculoskeletal injuries, helmet use, injury severity as assessed using the Abbreviated Injury Scale (AIS), the Injury Severity Score (ISS), and costs. Results: A total of 131 patients were included, of whom 90.8% were male, with a mean age of 43.2 ± 14.1 years. Most accidents were due to falls (83.7%). Accidents occurred in urban areas (56.3%), inter-urban roads (28.1%), and rural areas (15.6%). Upper limb fractures, particularly clavicle fractures (13.7%), were the most frequent injuries (31.0%). Traumatic brain injury (TBI) was present in 30.0% of patients, and 17.6% were polytraumatized. Injury severity was higher in males (p = 0.009) and in collisions compared with falls (p = 0.033). It was also correlated with length of hospital stay (r = 0.376). Patients with TBI exhibited significantly higher ISSs (p < 0.001). Helmet use was reported in 71.1% of patients and was more frequent in rural areas (p < 0.001) and associated with lower neurological AIS scores (p = 0.031). The mean cost per patient was €8545 ± 15,298, increasing with severity of injury (p < 0.001), and was higher in polytraumatized patients (p < 0.001) and in those with TBI. Conclusions: Cycling accidents most frequently resulted in upper limb fractures. Helmet use was more common where mandatory and was associated with less severe neurological injuries but not with a lower incidence of TBI. Costs increased with injury severity, particularly in patients with TBI and longer hospital stays. Full article

This study investigates the relationship between cardiorespiratory fitness and driving behavior in a highway environment using a driving simulator. A total of 46 young drivers aged 19 to 27 years participated in the experiment. Cardiorespiratory fitness was assessed through the Queen’s College Step Test and heart rate monitoring, allowing participants to be classified into high-fitness and low-fitness groups based on estimated maximum oxygen consumption. Each participant completed three simulated highway driving scenarios under varying traffic and lighting conditions. Driving performance data were continuously recorded, while additional individual and behavioral characteristics were collected through a structured questionnaire. The analysis focused on key performance indicators, including headway distance variability, average speed, and time to collision. Statistical analysis was conducted using regression models. The results indicate that higher physical fitness is associated with greater adaptability in driving behavior, reflected in increased headway variability and slightly higher driving speeds. At the same time, high-fitness drivers exhibited longer time to collision, suggesting improved anticipation and more effective management of traffic conditions. Environmental factors, particularly traffic volume and lighting conditions, remained dominant in shaping driving behavior. Overall, the findings suggest that physical fitness contributes to a more adaptive driving style on highways. By integrating physiological condition into the analysis of driver behavior, this study highlights the importance of considering health-related factors in road safety research and provides insights for developing preventive strategies targeting young drivers. Full article

This study investigates the growth and evolution of SiO₂-based inclusions in Si-killed steel under stagnant conditions and varying oxygen levels. Deoxidation experiments were conducted in a high-temperature furnace using commercial FeSi, with systematic variations in holding time and total oxygen content. Automated SEM–EDS analysis was employed to quantify inclusion size, number density, and chemical composition. Under stagnant conditions, SiO₂ inclusions were observed to grow and coarsen in the absence of melt agitation, following a t^1/3 scaling law. In high-oxygen melts, rapid inclusion growth was dominated by Stokes collision mechanisms, resulting in the formation of inclusions in the size range of 1–5 μm, which were subsequently removed by flotation. In contrast, low-oxygen melts exhibited slower growth kinetics governed primarily by Brownian motion and Ostwald ripening, producing smaller inclusions with characteristic sizes of 1–2 μm. These results demonstrate that the initial oxygen content plays a decisive role in controlling the dominant growth mechanisms and the extent of inclusion coarsening in non-agitated steel. Full article

Optically pumped magnetometers (OPM) are core quantum payloads for geomagnetic remote sensing. Among them, the spin-exchange relaxation-free (SERF) OPM with aT-level ultimate sensitivity stands as mainstream. While enlarging the alkali-metal vapor cell of the SERF OPM enhances sensitivity, it triggers complex atomic spin relaxation, notably intensified magnetic field gradient relaxation. To address the dilemma of atomic spin relaxation regulation and the engineering requirements of ultra-high-sensitivity SERF magnetometers, this paper constructs an analytical model of the total relaxation rate that comprehensively considers wall-collision relaxation, spin-destruction collision relaxation, and longitudinal/transverse magnetic field gradient relaxation, etc. The analytical relationship between buffer gas pressure and total relaxation rate for a commonly used spherical vapor cell is derived, revealing the intrinsic correlation among cell size, atomic spin relaxation, and optimal pressure. Based on the theoretical model, the filling parameters of the vapor cell are optimized, and experimental measurements are carried out. The theoretical relaxation results are highly consistent with the experimental ones, realizing the precise optimization of buffer gas pressure. The optimization method proposed in this paper provides a theoretical basis and parameter guidance for the engineering preparation of alkali-metal vapor cells for high-sensitivity SERF magnetometers in remote sensing applications. Full article

In a steel continuous casting mold, argon bubbles injected through the submerged entry nozzle undergo transport, coalescence, and turbulent breakup, producing a polydisperse bubble swarm that affects flow stability and defect formation. In this study, an Euler–Lagrange model coupled with bubble collision coalescence and turbulence-induced breakup sub-models was established and validated using water model observations. Three daughter-bubble volume distribution models were compared in terms of bubble-cloud morphology, number-fraction distribution, and median-diameter evolution at different gas flow rates. For the median bubble diameter at different gas flow rates, the M-type model gives the lowest mean absolute error of 0.0349 mm. Large bubbles with diameters greater than 2.5 mm accounted for about 4% of the total number and were mainly concentrated near the SEN, whereas small bubbles with diameters of 1.0–1.5 mm accounted for about 60% and were dispersed throughout the upper recirculation region. Mechanism analysis further shows that bubble transport is drag-dominated in the high-velocity jet region, while buoyancy becomes more important in weaker flow regions; turbulent breakup is localized mainly in high-dissipation regions. Full article

The determination of soluble elemental contaminants in tattoo inks is challenged by the lack of standardized extraction procedures, limiting the comparability of analytical results and the assessment of exposure-relevant fractions under the European REACH framework. In this study, artificial sweat extraction was applied as a mild and physiologically relevant approach to evaluate elements potentially released from tattoo inks under sweat-simulated skin-contact conditions. Seventy-eight commercial tattoo inks of different colors were extracted with artificial sweat at 37 °C for 1 h and analyzed by inductively coupled plasma mass spectrometry. Optimization of collision/reaction cell conditions, dilution strategy, and internal standard correction effectively reduced matrix-related interferences caused by the high salt and chloride content of artificial sweat, ensuring reliable quantification. Matrix-matched calibration was required due to significant signal suppression for several analytes. Method accuracy and precision, assessed using NIST 1643f and spiked samples, were generally satisfactory. Elemental release showed marked color-dependent trends, particularly for Cu, Zn, Ba, Al, Ga, Si, Sr, and Zr, reflecting differences in pigment composition and formulation. Soluble Ba, Cu, and Zn remained below EU regulatory limits. While total digestion remains essential for complete characterization, the proposed methodology provides a simple and transferable tool for exposure-oriented assessment of potentially bioaccessible elements in tattoo inks. Full article

A comprehensive and systematic study was conducted to address a series of key technical challenges encountered in the grinding process at a copper mine. These issues included the complex mechanical properties of the feed ore, which led to low grinding efficiency, difficulty in achieving the required grinding fineness for flotation, uneven particle size distribution in the grinding products, and severe occurrences of overgrinding and undergrinding. Based on the semi-theoretical ball diameter formula, the optimal initial ball size distribution for the ball mill was precisely calculated as Φ70:Φ50:Φ40:Φ30 = 15:25:35:25. Through laboratory-scale grinding tests and Discrete Element Method (DEM) simulations, a systematic analysis of multiple indicators under three different ball loading schemes was performed, including the motion state of particles inside the mill, the collision behavior of the grinding media, and the energy distribution. This analysis confirmed the rationality and effectiveness of the literature scheme. Industrial trial results showed the following: the yield of the +0.20 mm fraction decreased by 4.15 percentage points, and the yield of the −0.010 mm fraction and its proportion relative to the −0.074 mm fraction decreased by 10.17 and 19.10 percentage points, respectively. Conversely, the yields of the intermediate separated fraction (−0.20 + 0.010 mm), the easily separated fraction (−0.074 + 0.018 mm) and the −0.074 mm qualified fraction increased by 14.32, 14.13, and 7.29 percentage points, respectively. The grinding technical efficiency improved by 19.55 percentage points. Furthermore, the specific steel ball consumption decreased by 46 g/t, a reduction of 5.07%. The copper concentrate recovery increased by 0.65 percentage points, resulting in an annual increase of 40.51 tons of copper metal, additional revenue of CNY 3.2483 million, and steel ball cost savings of CNY 603,500. Collectively, this optimization generated a total economic benefit of CNY 3.8518 million. By optimizing the ball size distribution, the particle size composition of the grinding products was significantly improved, the flotation indicators were enhanced, and the grinding media consumption cost was reduced, achieving quality improvement and efficiency increase in the mineral processing. This study provides a valuable reference for solving similar grinding problems. Full article

Electric vehicles introduce new considerations for pedestrian safety because their lower operating noise at low speeds may reduce pedestrian detectability in urban traffic environments. This study proposes a simulation-based integrated active–passive pedestrian protection framework for electric vehicles by linking automatic emergency braking, active hood deployment, and post-crash head injury assessment. A total of 688 valid pedestrian–vehicle crash records from the National Highway Traffic Safety Administration database were analyzed, and 5 representative pedestrian crash scenarios were constructed through clustering-informed scenario screening and a benchmark pedestrian AEB scenario. The scenarios were reconstructed in a PreScan–Simulink co-simulation environment to evaluate a time-to-collision-based AEB strategy, while the active hood system was assessed using multi-body dynamics simulation and finite element head impact analysis. The AEB results showed that three scenarios were avoided before pedestrian contact, whereas two remained unavoidable, with residual impact speeds of approximately 31.5 km/h and 46 km/h. The hood reached a stable deployed posture within approximately 0.1 s under the modeled conditions. The HIC₁₅ results at eight selected impact points showed that speed reduction and hood deployment generally reduced head injury metrics, but full compliance with the reference HIC₁₅ threshold of 1000 was not achieved at all points. These findings suggest that the proposed strategy can improve simulated pedestrian head protection performance under selected electric vehicle crash scenarios, while further structural optimization, experimental validation, and cost–benefit assessments are still required. Full article