Search Results (822)

In the campus planning of severe cold regions, indoor pedestrian corridors have emerged as an important strategy for mitigating harsh weather and maintaining pedestrian network continuity. These enclosed systems provide thermal comfort and physical convenience for faculty and students. However, reduced visual contact with outdoor natural environments may be associated with less favorable affective experiences. Existing research primarily emphasizes functional connectivity and spatial efficiency, with limited quantitative evidence on the visual characteristics of indoor corridors and their relationship with emotional perception. Drawing upon environmental psychology, this study examines the associations between corridor visual characteristics and five AI-predicted affective perception dimensions. Using deep-learning-based computer vision, semantic segmentation, and statistical analysis, environmental features and predicted perception scores were analyzed. A local human validation showed moderate overall agreement between human consensus ratings and AI-predicted scores, supporting their use as exploratory perception proxies. The findings indicate that indoor-corridor-related visual features were negatively associated with predicted beauty scores and positively associated with predicted depression scores, while predicted boringness was positively associated with wall enclosure. Predicted safety and liveliness showed weaker associations with individual visual features. These results provide exploratory evidence for balancing thermal protection, circulation efficiency, and psychological comfort in future campus corridor design. Full article

Highland pastures in Montenegro, known as katuns, are seasonal settlements without grid power or network coverage and which are located where conventional monitoring is unfeasible. This study presents a solar-powered, off-grid system for livestock and environmental monitoring. It integrates, into a single portable unit, a solar power station, an edge-AI computer, a camera, environmental sensors, a LoRaWAN gateway, and a cellular router for backhaul. All parts are pre-wired in a modular enclosure, deployable by one operator in under 30 min. Data are fed to the agroNET farm-management platform and a purpose-built mobile web application; livestock detection runs on-device using a model from our earlier work. The system was evaluated at three sites, including a highland katun near Žabljak (~1450 m), under a two-phase energy-measurement protocol. During field logging it drew ~75 W on average against ~125 W solar input—a measured surplus that is used to recharge the battery—with a daily monitoring load of ~1560 Wh. The four-panel array’s nameplate potential in summer is an estimated ~3700 Wh/day, indicating substantial headroom relative to the measured load. At 80% depth of discharge the battery gives ~20 h autonomy, and the detection pipeline ran continuously, processing ~10,000 frames at under 3 s latency. The results demonstrate the feasibility of off-grid precision livestock farming, reaching TRL 6. Full article

Traditional methods for wine bottle packaging leakage detection often suffer from low efficiency, high false-positive rates, or an inability to detect micro-leakages. This paper proposes a near-infrared laser leakage detection system based on tunable diode laser absorption spectroscopy at 1392 nm, combined with a LightGBM machine learning model. The system detects gaseous ethanol vapor escaping from leaking bottles, addressing the spectral interference caused by ambient water vapor. A total of 1410 samples were collected, and each raw 2000-point spectral contour was compressed into a 200-dimensional feature vector through baseline correction, Z-score normalization, and uniform down-sampling. A two-stage hyperparameter optimization strategy yielded the optimal LightGBM configuration with a 5-fold cross-validation. For the binary classification task, the model achieved an AUC of 0.9949 and an inference speed of 0.0058 ms per sample on a CPU, outperforming Random Forest, PLS, and four deep learning models. For the regression task, the model achieved an R² of 0.5854 ± 0.0919. An anti-interference experiment on 422 samples under varying flow rates, temperatures, and commercial wine types confirmed the model’s robustness, achieving an overall accuracy of 0.94 and an alcohol recall of 0.99. To further validate the system under realistic conditions, a simulated micro-leakage test was conducted using a negative-pressure extraction method: 320 samples were collected from artificially damaged commercial wine bottles placed in a custom-built acrylic vacuum chamber that replicates the production line enclosure. The model achieved an accuracy of 0.95 with zero false negatives. The complete detection cycle takes no more than 5 s per bottle, enabling non-destructive, rapid, and online packaging integrity assessment. The results demonstrate that the proposed system provides a low-cost and reliable solution for wine bottle leakage detection suitable for industrial deployment. Full article

Explosion venting is widely used to limit overpressure in confined systems, although its effectiveness depends on complex interactions between combustion, flow, geometry and external conditions. This review examines the phenomenology of vented hydrogen explosions, the main parameters governing their severity, recent experimental and numerical advances, and current design standards. The literature shows that hydrogen concentration, ignition position, vent characteristics, congestion, enclosure geometry and scale affect not only the maximum overpressure, but also the sequence and physical origin of the pressure peaks. Experimental studies highlight the importance of external cloud combustion, flame-acoustic coupling and obstacle-induced turbulence, while CFD models can reproduce overall pressure and flame-propagation trends but remain sensitive to modelling assumptions and validation conditions. Existing standards, particularly EN 14994:2007 and NFPA 68:2023, provide a valuable basis for preliminary design and engineering practice, although additional assessment may be required for highly reactive mixtures, congested layouts and non-standard geometries. Further large-scale testing, benchmark validation and integrated experimental-numerical approaches are needed to improve the reliability of explosion-venting design for hydrogen applications. Full article

With the acceleration of urbanization, wind environment problems in high-density blocks have become increasingly prominent. Most existing studies only focus on the identification of influencing factors, lacking a complete closed loop from “diagnosis” to “design verification”. This study takes 174 blocks along the Qingnian Street Metro Line in Shenyang as research objects, uses PHOENICS (2019) software, and clarifies the seasonal distribution characteristics of the wind environment in high-density blocks through field measurement and simulation verification. The XGBoost-Shap method is employed to identify key morphological factors and their nonlinear influence mechanisms. The K-means clustering method is adopted to construct the typology of calm wind zones, which are classified into three categories: Type A (narrow street canyon-comprehensive resistance type), Type B (high-density enclosed type), and Type C (high-rise obstruction type). Multi-scenario simulations are conducted for each type, and differentiated optimization schemes are designed accordingly. The results show that under specific CFD boundary conditions representing typical cold climate urban environments, eight indicators, including enclosure degree (ED), sky visibility (SVF), and windward area ratio (FAI), have significant seasonal sensitivity effects on wind environments. The effect of multi-strategy collaborative optimization is significantly superior to that of a single intervention. This study verifies the effectiveness of the typological approach in bridging wind environment mechanism identification and spatial optimization design. Thresholds for indicators such as enclosure degree (ED), sky visibility (SVF), and building density (BD) can be used as preliminary design-screening tools, providing a reference for ventilation improvement design ideas along high-density subway lines in actual urban construction. Full article

Hydrogen peroxide vaporization (HPV) is an established no-touch environmental disinfection technology; however, conventional systems require manual setup and may involve prolonged operating times. This study evaluated a newly developed HPV Smart Robot designed to automate hydrogen peroxide vapor distribution and aeration in a controlled clinical simulation environment. A comparative performance evaluation was conducted in a 48.7 m² clinical simulation enclosure. Four experimental cycles were performed, including one conventional HPV cycle and three robotic HPV cycles operated under different navigation modes and fan-angle configurations. Geobacillus stearothermophilus biological indicators (BIs) were used to assess sporicidal efficacy, while chemical indicators and hydrogen peroxide concentration measurements were used to evaluate vapor distribution. Complete biodecontamination was achieved at all 20 environmental sampling locations in every experiment. When four robot-internal sampling sites were included, biodecontamination rates ranged from 95% to 100%, with a single persistent positive biological indicator detected at a recessed fan–corner junction within the robotic platform. All experiments achieved hydrogen peroxide concentrations above the manufacturer-recommended target threshold (≥140 ppm). Although the robotic system demonstrated greater spatial variability in hydrogen peroxide concentration than the conventional system, effective sporicidal activity was maintained throughout the enclosure. The robotic platform reduced setup time from approximately 15 min to 5 min and shortened total cycle duration from approximately 285 min to 221–231 min. In this controlled simulation study, the HPV Smart Robot demonstrated high microbiological efficacy and improved operational efficiency compared with a conventional HPV workflow. These findings support the feasibility of robotic HPV biodecontamination systems while highlighting the importance of airflow optimization and internal component design to ensure consistent vapor penetration. Full article

Spacecraft electrostatic discharge (ESD) can generate transient electric-field disturbances, pulse currents, and electromagnetic coupling that threaten onboard electronics and mission reliability. Localizing discharge sources in confined spacecraft spaces remains difficult because conventional time-difference-of-arrival, radio-frequency, acoustic, and optical methods often require strict synchronization, large arrays, suitable propagation media, line-of-sight conditions, or explicit propagation models. This study develops a spacecraft-oriented, ground-validated electrostatic-induction sensor-array framework for three-dimensional localization of transient discharge events. Different from conventional received-signal-strength-based Apollonius localization, the proposed approach uses relative transient electrostatic-induction response features, including root-mean-square value, envelope energy, and integrated energy, and calibrates their feature ratios into distance-ratio constraints using a Power + offset mapping. These calibrated constraints are interpreted as Apollonius-sphere constraints, and the source coordinate is estimated by nonlinear residual minimization without relying on high-precision arrival-time picking. The method is evaluated on a controlled one-cubic-meter confined-space laboratory platform with known sensor geometry. Ten independent test positions show centimeter-level localization accuracy in the present calibration domain. The envelope-energy representation performs best, with a mean three-dimensional error of 7.01 cm, a median error of 6.94 cm, and a maximum error of 10.05 cm. These results demonstrate the feasibility of the sensing–calibration–inversion chain as a preliminary ground-based proof of concept. The reported accuracy should not be interpreted as direct on-orbit performance because the present experiment does not include vacuum, plasma, thermal gradients, spacecraft materials, metallic enclosures, or electronics integrated for spacecraft onboard operation; further environment-specific calibration and validation are required before practical spacecraft deployment. Full article

Thermal energy storage plays a crucial role in meeting human energy demands and is particularly essential for many solar energy applications. Among the various storage methods, phase change materials (PCMs) have attracted significant attention because their thermal performance can be greatly influenced by the material properties, physical characteristics, and the geometry of the encapsulating container. In this paper, the melting process of phase change materials (PCMs) within an elliptical enclosure using the finite volume method is analyzed. Gallium is selected as a PCM with a low Prandtl number. A physical model employing the enthalpy porosity formulation is elaborated to describe the coupling between natural convection and the melting process of PCMs. Numerical simulations are performed to examine the influence of the aspect ratio (n = b/a), ranging from 1 to 4, and inclination angles from 0° to 90° of the elliptical enclosure on the melting process. It has been found that the use of the elliptical capsule can reduce the melting process time. For a Rayleigh number of ${10}^6$, the melting time decreases as the aspect ratio increases from 1 (circle) to 4. The horizontal orientation (θ = 0°) is found to be the most efficient, with a melting rate higher than that observed for inclined positions (30°, 45°, 60°, and 90°). For a low Rayleigh number of ${10}^4$, the inclination angle has an imperceptible effect on the phase change. Empirical correlations are proposed to relate the Nusselt number to the Rayleigh number, with coefficients adapted to different Fourier numbers and geometric parameters. Full article

Autonomous driving sensor fusion housings (SFHs) integrate LiDAR, radar, camera, and computing modules within a shared mechanical and thermal enclosure. This review examines how coefficient of thermal expansion (CTE) mismatch among housing polymers, aluminum heat spreaders, substrates, and solder joints can contribute to interfacial delamination, solder joint fatigue, optical misalignment, and Thermomechanical Coupling Interference (TMCI). Using a structured narrative review of 99 publications and authoritative standards from primarily 2009 to 2026, the article organizes the evidence into a 4 × 4 taxonomy linking four failure mechanisms with experimental, computational, AI/ML, and qualification-oriented approaches. The review explicitly distinguishes direct literature evidence, transferred package-level evidence, model-based extrapolation, and author-derived conceptual estimates. Accordingly, TMCI temperature increments, sensor spacing values, optical drift estimates, and lifetime projections are discussed only as case-specific screening-level hypotheses unless directly validated in the cited literature. Five research gaps are identified: standardized multi-sensor TMCI validation, aging-corrected material and solder fatigue databases, long-term qualification of thermally conductive nanocomposites, SFH-specific validation of physics-informed digital twins, and integrated multi-failure testing. The contribution of this article is therefore primarily structural and agenda setting: it clarifies what is supported by direct evidence, what is transferred from adjacent domains, and what remains to be validated before robust SFH-level reliability guidance can be established. Full article

With the expansion of metro networks and the increasing integration of underground retail and transit facilities, metro-connected underground commercial spaces have become a common yet safety-sensitive urban form. In fire scenarios, evacuation in such environments is constrained not only by enclosure and limited egress capacity, but also by the interaction between smoke spread and strongly coupled pedestrian flows across connected zones. Existing studies have examined smoke propagation or evacuation performance in underground spaces, but fewer have explicitly addressed how smoke constraints reshape node-level safety and the relative effectiveness of different intervention strategies in metro-connected commercial environments. This study investigates smoke-constrained evacuation dynamics in a representative metro-connected underground commercial space in Nanjing, China. A coupled simulation framework integrating PyroSim and Pathfinder is employed to examine multiple fire-source scenarios. Available safe egress time (ASET) at critical evacuation nodes is assessed using tenability criteria including visibility, temperature, and CO concentration, and is then compared with evacuation performance to diagnose hazardous routes and node-level failures. On this basis, three intervention strategies—corridor widening, stair widening, and pedestrian diversion—are comparatively evaluated. The results show that, within the modeled case, visibility most frequently becomes the controlling tenability criterion, and stairway nodes tend to lose safety margins earlier than final exits. This indicates that smoke constraints in connected underground commercial environments can trigger an early node-failure process before overall exit capacity is exhausted. The comparison further shows that behavior-oriented pedestrian diversion is more effective than geometric enlargement alone in reducing critical-node pressure and improving system-level evacuation performance under the modeled conditions. Rather than proposing universally transferable design rules, this study provides case-grounded evidence on how smoke propagation and pedestrian convergence jointly shape evacuation vulnerability in metro-connected underground commercial spaces, and offers a structured basis for critical-node diagnosis and intervention comparison in similarly configured environments. Full article

Battery housings are critical structural and safety components in electric vehicles, fulfilling multiple functions related to mechanical protection, crashworthiness, thermal management, fire resistance, electromagnetic shielding, and integration of battery modules into the vehicle body. While metallic housings, particularly aluminum and steel, remain dominant in industrial applications, increasing attention is being given to composite materials as lightweight alternatives capable of improving energy efficiency and extending driving range. However, the growing use of composites in battery enclosures raises important questions regarding recyclability, end-of-life management, and compatibility with circular economy principles. This review critically examines the current state of the art in composite materials used for electric vehicle battery housings, with particular emphasis on glass- and carbon-fiber-reinforced thermoplastics, thermoset composites, sandwich structures, and hybrid multi-material systems. The paper discusses the functional requirements imposed on battery housings and analyzes how these requirements influence material selection and design strategies. Particular attention is devoted to recycling pathways applicable to composite battery enclosures, including mechanical recycling, thermal treatment, chemical recycling, and reuse-oriented approaches, as well as to the limitations associated with mixed-material assemblies, adhesives, coatings, and integrated functions. The review also addresses circular design strategies for battery housings, including design for disassembly, material traceability, modularity, and the incorporation of recycled polymers and secondary reinforcements into new housing systems. Current research gaps are identified in the integration of structural performance, fire safety, manufacturability, and recyclability within a single design framework. The analysis shows that thermoplastic composites currently offer the most promising route toward circular battery enclosures, while thermoset-based systems still face significant challenges in high-value recycling. The paper concludes by outlining future research directions required for the development of lightweight, safe and recyclable composite battery housings aligned with sustainable mobility and circular economy goals. Full article

Air pollution in Almaty, Kazakhstan, poses a critical public health challenge intensified by the city’s basin topography and seasonal thermal inversions that trap anthropogenic emissions. The sparse stationary network (~5 stations for ~2 million inhabitants) lacks the spatial and temporal resolution needed to capture intra-urban variability. We present the design, deployment, and field evaluation of a low-cost distributed Internet of Things (IoT) network of six custom nodes—Winsen ZPHS01B multi-parameter modules with Raspberry Pi Zero 2 W edge units, at an estimated principal-component cost of ~US$100 per node—operated during a winter-spring campaign (February–April 2025) and yielding over 70,000 measurements of PM_2.5, PM₁₀, CO₂, temperature, and relative humidity. The system’s novelty lies in three integrated engineering features: an Active Airflow Stabilization enclosure that decouples sampling from external wind, context-aware adaptive edge filtering that reduces transmitted data volume by ~40%, and a secure Edge-DMZ-Core telemetry pipeline. Node readings were cross-validated against a Qingping Air Monitor Pro with documented traceability to FEM-grade reference analyzers (R² = 0.89–0.95), and city-scale consistency was confirmed against the national monitoring dashboard; the network is therefore characterized as providing internally consistent low-cost observations rather than reference-equivalent concentrations. Daily mean PM_2.5 exceeded the WHO 24 h guideline (15 µg/m³) on 84% of monitored days, with February concentrations (54.4 µg/m³) significantly above March (21.9 µg/m³; p < 0.001). A high PM_2.5/PM₁₀ ratio (~0.96), measured at the physically consistent nodes, together with higher weekend concentrations, points to coal-based residential heating as the most likely dominant source. A coupled WRF-SILAM framework is configured for future model-observation integration. The system offers a reproducible, scalable, and cost-effective template for ambient particulate monitoring in resource-constrained cities with complex terrain. Full article

Background/Objectives: Healthy animals can harbor complex and diverse bacterial communities, including pathogenic taxa capable of causing disease and mortality, and individuals that are kept in zoos may act as asymptomatic carriers of a broad range of pathogens. Therefore, this study aimed to investigate the rectal bacterial microbiota of multiple animal classes (reptiles, birds, and mammals), maintained in enclosures, identify known or emerging bacterial pathogens, and characterize the antibiotic resistance profiles of the isolated strains. Methods: A total of 40 samples were collected by rectal swabbing for bacteriological analysis from 31 different animal species living in enclosures in four Algerian zoos. The isolated and identified bacterial strains were tested against certain antibiotics used in human and veterinary medicine. Statistical analyses were performed to assess differences in bacterial isolation among animal classes, sex, age categories, and zoological facilities, as well as the degree of similarity between isolated strains based on their antibiotic resistance profiles. Results: A total of 94 bacterial isolates were recovered from 40 fecal samples. Overall, the bacterial isolates belonged to seven families, 13 genera, and 16 taxa. The families identified were Enterobacteriaceae (50/94; 53.19%), Staphylococcaceae (28/94; 29.78%), Pseudomonadaceae (6/94; 6.38%), Brucellaceae (2/94; 2.12%), Morganellaceae (4/94; 4.25%), Yersiniaceae (3/94; 3.19%), and Erwiniaceae (1/94; 1.06%). Reptiles accounted for the highest number of isolates (37/94; 39.36%), followed by 31/94 isolates (32.97%) for birds and 26/94 isolates (27.65%) for mammals. The highest resistance rates were observed for ampicillin (AMP; 95.73%), followed by amoxicillin/clavulanic acid (AMC; 75.54%) and cephalothin (CEP; 44.90%). Lower resistance rates were detected for trimethoprim–sulfamethoxazole (SXT; 18.87%), cefotaxime (CTX; 17.41%), ceftazidime (CX; 13.67%), ciprofloxacin (CIP; 6.38%), and gentamicin (GEN; 1.05%). Conclusion: This study shows the first report that vertebrates in Algerian zoos can harbor a diverse range of cultivable bacteria, often with polymicrobial carriage. Antimicrobial resistance patterns were generally consistent with commonly used veterinary drugs. Overall, these findings contribute to a better understanding of the composition of rectal bacterial carriage in zoos. Full article

This work proposes guidelines for coding a grafcet on a microcontroller, following the specifications described in standard IEC 60848:2013. While previous works exist for coding a simple grafcet on platforms like Arduino or STM32, they overlook implementing timers, hierarchical structure, and other advanced resources included in the IEC 60848:2013. Throughout this study, procedures for implementing the majority of the resources described in the standard using pseudocode and C++ are presented. These resources include timers, stored actions, macrosteps, enclosures, and forcing orders, among others. Previously, it has been necessary to identify ambiguities, vagueness, inaccuracies, and the non-modular approach of the IEC 60848:2013 standard that impeded a proper and unequivocal implementation, proposing improvements and interpretations to make it more unequivocal and exportable. Examples are included to illustrate how to apply the proposed guidelines, and a template to assist in coding any grafcet is made available in a repository. As a result, this article provides designers with a complete set of tools and resources to unequivocally implement concurrent discrete-event processes. The implementation on several microcontrollers exhibits exceptional memory efficiency under scaled stress-testing conditions (100 steps and 25 timers): less than 2% of the RAM for STM32F411RE and ESP32, and less than a 1.5% increase in ROM when implementing the analysis of 100 transitions and the definition of 25 timers. This proves its scalability for complex discrete-event applications. Cycle times depend on whether there is access to macrostep expansions and enclosures but are around 80 microseconds for the STM32F411 and 20 microseconds for the ESP32. Full article

In Guangzhou’s Shangxiajiu Pedestrian Street, street segments with higher billboard densities exhibited greater proportions of both brief stops and extended dwell, while segments with higher densities of illuminated signage at night also showed greater proportions of extended dwell. Higher street width-to-height ratios and greater ground-floor façade transparency were associated with increased afternoon pedestrian activity and brief stopping, respectively. Using 13 street segments as the units of analysis, this study combined on-site measurements, synchronized behavioral observations, and correlation analysis to examine the associations of billboard density, illuminated signage density, street width-to-height ratio, and façade transparency with brief stopping, extended dwell, and through-movement behavior. The results showed that billboard density was strongly and positively correlated with both the mean proportion of brief stops and the mean proportion of extended dwell (r = 0.749, p = 0.003; r = 0.832, p < 0.001). Illuminated signage density was also strongly and positively correlated with the proportion of extended dwell at night (r = 0.823, p = 0.001). Street width-to-height ratio was positively correlated with both the afternoon proportion of brief stops and the afternoon proportion of total pedestrian activity, while façade transparency was positively correlated with the afternoon and mean proportions of brief stops. These findings indicate that, in the case of Shangxiajiu Pedestrian Street, pedestrian dwell was more concentrated in street segments characterized by richer commercial information, greater nighttime visibility, more open spatial configurations, or more legible storefront interfaces. The findings provide field-based quantitative evidence to inform signage layout, ground-floor interface optimization, the coordination of street enclosure, and the management of nighttime visual environments in historic commercial streets. Full article