Search Results (76)

Sustainable development in cities has gained popularity due to the emergence of numerous urban challenges in harsh environments. Selecting an accurate turbulence model in CFD is crucial for assessing the outdoor environment. Among the widely used microclimate simulation tools, ENVI-met stands out for its convenience and its proven effectiveness in urban microclimate studies. Elevated design, often referred to as ‘lifted up design,’ is standard in architectural practice, serving both as recreational spaces and corridors, potentially improving thermal comfort. To ensure reliable microclimate modeling, assessments in such areas should be validated against empirical data. This study compares the microclimatic conditions in open space beneath an elevated building using ENVI-met with on-site meteorological data collected in Xi’an, China, across three days with varying weather conditions. The results show that ENVI-met can reasonably reproduce air temperature (R² = 0.80–0.96, RMSE = 0.67–1.42 °C), relative humidity (R² = 0.85–0.99, RMSE = 2.83–9.32%), and mean radiant temperature (R² = 0.87–0.90, RMSE = 4.11–7.23 °C) under different conditions, though some deviations exist—especially with diffuse radiation, which ENVI-met tends to underestimate beneath elevated structures. Despite these discrepancies, the model performance was evaluated by comparing field measurements with ENVI-met outputs, and the results indicate that ENVI-met can provide useful insights for simulating microclimate conditions in open spaces beneath elevated buildings under different weather conditions. Full article

Fiber-reinforced polymer (FRP)-reinforced concrete beams are increasingly used in infrastructure, yet their flexural behavior under fatigue and harsh environmental conditions remains insufficiently studied. This study investigates the fatigue response and structural behavior of 12 glass-FRP (GFRP)-reinforced concrete beams under four environmental regimes: indoor control, continuous alkaline immersion, cyclic wet–dry alkaline immersion, and outdoor exposure in Montreal. Four pre-cracked beams were subjected to up to one million load cycles, while deflection and crack mouth opening displacement (CMOD) were monitored. Structural behavior was evaluated in terms of flexural capacity, load–deflection response, crack development (CMOD), stiffness degradation, and serviceability limit state (SLS) performance before and after fatigue loading. Results show that W&D and Immersion beams exhibited the largest deflections (δ_exp/δc_ode = 158% and 92%, respectively), whereas Outdoor and Control beams maintained robust load capacity with minimal fatigue effect. Flexural toughness indices varied from 8.61 to 18.45 across specimens, highlighting environmental influence on energy absorption. Serviceability limit state criteria were reached between 400,000 and 850,000 cycles, depending on conditioning. Overall, GFRP-RC beams demonstrated strong residual strength and predictable degradation patterns, providing quantitative insight into fatigue performance under combined environmental and cyclic loading. Full article

People living in India are experiencing some of the hottest summers on the planet. Conditions are particularly harsh in Indian cities, like Kolkata, where high temperatures are combined with high humidity. Understanding how conditions in Kolkata have evolved could provide an important addition to the growing study of the problems facing megacities in the hot, humid tropics. Yet in Kolkata, this understanding is obscured by different, often incompatible, methods of assessing the intensity of heat stress. This narrative review considers the problems encountered when attempting to develop a clear understanding of past increases or even to quantify current conditions using conventional meteorological or remote sensing data. Rather than trying to arrive at a precise quantification of how much hotter it is now in Kolkata than in the past, we argue for more fine-grained, individual-level understanding of how heat is experienced. An example of this approach is provided by a study that used telemetric devices to continuously monitor the temperature and humidity to which elderly residents of slum areas in Kolkata were exposed during 24h periods as they went about their daily lives. This study indicates that individuals experience a diversity of heat conditions that are inadequately represented by outdoor temperatures. Living in dwellings where indoor temperatures are often hotter than outdoor temperatures, the daily heat stress experienced by this vulnerable group varies between conditions that are stressful but endurable to those that approach the limits of human heat tolerance. Given the likelihood of even hotter environments in the future, urban planners will need access to more comprehensive heat studies, focusing on continual monitoring of heat stress and physiological responses of individuals from different walks of life. Full article

To address poor wear resistance of surface metal grids for optical windows and low efficiency and poor uniformity of traditional embedded technologies, this study fabricates ultra-wear-resistant embedded metal grids on 180 mm × 180 mm × 8 mm sapphire via photolithography and large-area plasma etching. Etching grooves (depth about 300 nm) and depositing 135 nm silver (Ag) + 170 nm alumina (Al₂O₃) films, the grids exhibit transmittance 80.2%~80.9% (2~5 μm), wear resistance without damage, and reliable EMI shielding (Electromagnetic Interference Shielding) (3~18 GHz), offering a scalable solution for harsh-environment optoelectronic windows. The embedded structure integrates high transmittance, ultra-wear resistance, and reliable EMI shielding, addressing the core demands of optoelectronic windows in aerospace, outdoor monitoring, and other harsh environments where durability and stability are critical. The key innovation lies in the optimized integration of large-area plasma etching and low-temperature electron beam deposition, achieving precise control of groove depth uniformity (<4%) and transmittance uniformity (<1%) on high-hardness sapphire substrates, which overcomes the trade-off between efficiency and uniformity in traditional embedded technologies. Future applications include high-performance optical windows for airborne surveillance systems, space-borne optoelectronic devices, and harsh-environment industrial monitoring equipment, with potential extension to other high-hardness dielectric substrates. Full article

Ensuring food security requires innovative, sustainable pest management solutions. The Solar Insecticidal Lamp Internet of Things (SIL-IoT) represents such an advancement, yet its reliability in harsh, variable outdoor environments is compromised by frequent component and sensor faults, threatening effective pest control and data integrity. This paper presents a comprehensive survey on fault detection (FD) for SIL-IoT systems, systematically analyzing their unique challenges, including electromagnetic interference, resource constraints, data scarcity, and network instability. To address these challenges, we investigate countermeasures, including blind source separation for signal decomposition under interference, lightweight model techniques for edge deployment, and transfer/self-supervised learning for low-cost fault modeling across diverse agricultural scenarios. A dedicated case study, utilizing sensor fault data of SIL-IoT, demonstrates the efficacy of these approaches: an empirical mode decomposition-enhanced model achieved 97.89% accuracy, while a depthwise separable-based convolutional neural network variant reduced computational cost by 88.7% with comparable performance. This survey not only synthesizes the state of the art but also provides a structured framework and actionable insights for developing robust, efficient, and scalable FD solutions, thereby enhancing the operational reliability and sustainability of SIL-IoT systems. Full article

This study developed high-performance anti-flashover silicone coatings using sol–gel-synthesized CaCO₃/SiO₂ hierarchical fillers optimized via L₁₆(4⁵) orthogonal design. The optimal filler (Sample 5) was prepared under 70 vol% ethanol, with nTEOS:nCaCO₃ = 1:1 and 0.2 mol/L NH₃·H₂O, at 45 °C, for 18 h, featuring covalent Si-O-Ca bonding, a dual-scale microstructure (2–4 μm CaCO₃ cores + 20–40 nm SiO₂ nodules), a 14.44 m²/g specific surface area, and bimodal porosity (8–80 nm). Composite C7 (30 wt% filler, 3 wt% KH-570, 1:2 resin-to-filler ratio) achieved superhydrophobicity (a 153° contact angle via Cassie-Baxter stabilization), ultrahigh electrical insulation (3.20 × 10¹⁴ Ω·cm volume resistivity, 1.60 × 10¹³ Ω surface resistivity), and robust mechanical properties (Shore 3H hardness, 5B adhesion). Standardized IEC 60507:2020 tests showed that C7’s flashover voltages (14.8 kV for KMnO₄, 14.3 kV for NaCl/KMnO₄, 13 kV for NaCl) exceeded that of neat silicone resin (NSR) and conventional CaCO₃-filled composite (SR-CC) by >135%. Additionally, C7 retained superhydrophobicity after 500 h UV aging and maintained a 124° contact angle after 12 months of outdoor exposure. The superior performance stems from synergistic hierarchical topology, tortuous discharge paths, and interfacial passivation. This work establishes a microstructure-driven design paradigm for grid protection materials in harsh environments. Full article

The human skin microbiome plays a crucial role in maintaining skin health by acting as a barrier against pathogens and modulating immune regulation. This case study investigates the skin microbiome of two healthy Korean male individuals in their 20s during Antarctic expeditions, focusing on microbial changes, reversion to pre-expedition states, and the influence of environmental and lifestyle factors. Notable microbial alterations were observed, including increases in Pseudomonadota and decreases in Actinomycetota, indicating pronounced microbial shifts in response to harsh environmental factors such as low temperature and humidity. Post-expedition revealed incomplete recovery to pre-expedition states, with Host A showing a higher resilience index, suggesting faster microbial recovery. Correlation analyses revealed associations between microbial changes and environmental factors (e.g., temperature, humidity, atmospheric pressure) as well as lifestyle factors (e.g., sunblock usage, outdoor activities), highlighting complex interactions between host behaviors and microbiome dynamics. Despite the study’s limited sample size, these findings offer insights into the adaptability and resilience of the skin microbiome under extreme environments, with potential implications for health management and skincare strategies during isolated and prolonged expeditions. Full article

This paper investigates the reliability of a dual-axis solar tracking system using Failure Mode and Effects Analysis (FMEA), Fault Tree Analysis (FTA), and Reliability Block Diagrams (RBD). The system’s control and data transfer subsystems are evaluated under indoor and outdoor conditions using failure rate data. Key vulnerabilities—particularly sensor degradation—are modeled through probabilistic analysis. Results show a significant drop in reliability (to 15.02%) in harsh environments, primarily due to light sensor failures. However, mitigation strategies such as Built-In Self-Test (BIST) architectures improve test coverage, thereby increasing the chance of fault detection. The findings highlight the need for reliability-focused design in solar trackers to ensure long-term energy efficiency and fault resilience. Full article

The phenomenon of global population aging poses considerable mobility challenges for older adults, particularly in cold climate regions, where the accessibility and configuration of street elements exert a significant impact on social participation and safety during severe winter conditions. Employing a combination of non-participatory observation, behavior mapping, and spatial analysis across different winter periods, this study investigates three residential streets in Harbin, China. The research systematically documents the types, frequencies, and spatial distributions of both social activities and street infrastructure utilized by the elderly. Subsequently, kernel density overlays of elderly social activity and street element distributions enable a nuanced analysis of the influence of environmental features on older adults’ social engagement throughout the three delineated winter phases. The findings reveal the following: (1) There is persistent demand for outdoor social interaction among the elderly, with participation rates inversely proportional to the severity of winter, peaking in early winter and declining through late and harsh winter stages; (2) Variations in activity types and durations are closely associated with spatial configurations: dynamic activities are predominantly observed along linear street segments, whereas passive behaviors cluster at intersections and broader street expanses; (3) There are several key aspects of street design and street furniture provision that help to support the use of streets in winter by the elderly. However, the influence of seating and fitness elements on mobile activities is limited. This study contributes to promoting inclusive urban design for older people in cold climates. Full article

The hybridization of cellular networks and GNSS systems has gained increasing attention, especially in urban canyons and indoor environments where GNSS performance degrades significantly. Hybrid localization is part of the 3rd Generation Partnership Project (3GPP) standard, offering an effective solution when satellite visibility is limited. Additional cellular measurements can enhance the accuracy and reliability of standalone UE. Hybrid methods offer multiple benefits: an improved availability, continuity, and integrity; better signal penetration due to proximity; a lower power consumption; and, in harsh environments, potentially more accurate positioning than a GNSS. Moreover, GNSS chipsets in mobile phones or smartwatches are typically power-intensive. This work presents a user-level hybridization method that enables UE to receive both GNSS and 4G/5G data and autonomously determine whether to apply hybrid positioning. The developed algorithms improve the precision and reliability, allowing user-driven decisions based on data quality. The system was tested under static conditions across various scenarios: outdoors, in urban canyons, and indoors. The results show that, while hybridization enhances positioning, the 4G-only solution often performs in terms of vertical accuracy. Standard deviation metrics help guide the selection of the most precise option in real time. Full article

The coastal regions of Fujian, characterized by a subtropical maritime monsoon climate, experience a high frequency of windy days throughout the year, which significantly impacts residents’ lives. Local traditional villages, through long-term practical exploration, have developed a unique “maze-like” spatial layout adapted to withstand harsh wind conditions. This study aims to quantitatively analyze the climatic adaptability advantages of this traditional layout, providing theoretical support for the protection of historical cultural heritage and guidance for modern village construction. The methodology includes field wind measurement for data acquisition, construction of current and regularized divergent models, and comparative numerical simulations under scenarios of strong winter winds and typhoons. The results indicate that wind speeds within traditional villages are generally lower. The layout’s nonlinear roads and clusters of buildings form multiple buffer zones that effectively reduce wind speeds. In contrast, areas in the divergent model experience excessively high wind speeds, impacting outdoor activity safety and comfort. The traditional “maze-like” layout encapsulates the climate adaptation wisdom of ancestors, enhancing wind environment regulation, thermal comfort, and disaster resilience. This layout concept merits promotion and innovative application in the new era to construct livable, green, and sustainable human environments. Full article

Construction activities are often conducted in outdoor and harsh environments and involve long working hours and physical and mental labor, which can lead to significant mental fatigue among workers. This study introduces a novel and non-invasive method for monitoring and assessing mental fatigue in construction workers. Based on cognitive neuroscience theory, we analyzed the neurophysiological mapping of spontaneous mental fatigue and developed multimodal in-ear sensors specifically designed for construction workers. These sensors enable real-time and continuous integration of neurophysiological signals. A cognitive experiment was conducted to validate the proposed mental fatigue assessment method. Results demonstrated that all selected supervised classification models can accurately identify mental fatigue by using the recorded neurophysiological data, with evaluation metrics exceeding 80%. The long short-term memory model achieved an average accuracy of 92.437%. This study offers a theoretical framework and a practical approach for assessing the mental fatigue of on-site workers and provides a basis for the proactive management of occupational health and safety on construction sites. Full article

High-density polyethylene (HDPE) waste poses a significant environmental challenge due to its non-biodegradable nature and the vast quantities generated annually. However, conventional recycling methods are energy-intensive and often yield low-quality products. Herein, HDPE waste is upcycled into anti-aging, superhydrophobic thin films suitable for outdoor applications. A two-layer spin-casting method combined with heating-induced crosslinking is utilized to produce an exceptionally rough superhydrophobic surface, featuring a root mean square (RMS) roughness of 50 nm, an average crest height of 222 nm, an average trough depth of −264 nm, and a contact angle (CA) of 148°. To assess durability, weathering tests were conducted, revealing the films’ susceptibility to degradation under harsh conditions. The films’ resistance to environmental factors is improved by incorporating a UV absorber, maintaining their hydrophobic properties and mechanical strength. Our research demonstrates a sustainable method for upcycling waste into high-performance, weather-resistant, superhydrophobic films. Full article

Urban residential areas significantly influence outdoor thermal comfort through architectural morphology. This study concentrates on the multi-objective optimization of the thermal comfort environment in residential areas, with a focus on Yulin—a city in the cold, inland region of Northwestern China. Yulin is characterized by its distinctly defined seasons, particularly harsh and windy conditions in the spring, which significantly impact thermal comfort. Utilizing field surveys, characteristics of scale and layout from high-rise residential areas in Yulin were extracted to formulate design strategies adapted to local climates. The Universal Thermal Climate Index (UTCI) served as the optimization criterion, and genetic algorithms, integrated with parametric modeling software, generated multiple layout schemes. These were refined through the Pareto evolutionary algorithm II to optimize thermal comfort across seasons. Furthermore, the Sobol’ sensitivity analysis method was employed to assess the impact of key parameters on outdoor thermal comfort, identifying crucial layout design elements. The optimization improved UTCI values for different seasons, ensuring year-round comfort. Specifically, summer UTCI improved to 25.51, while winter and spring values reached optimal values of −14.02 and −6.41, demonstrating enhanced thermal retention and reduced wind exposure. Sobol’ sensitivity analysis identified building length, orientation, and density as key parameters, highlighting their critical impact on thermal comfort. This study offers practical guidelines for urban residential area design in similar climatic zones, aligning architectural planning with environmental sustainability and enhancing thermal comfort effectively. This study provides practical guidelines for the design of residential areas in cold inland—seasonal windy—regions and other similar climatic zones, aligning building morphology design with environmental sustainability and enhancing thermal comfort effectively. Full article

LEDs (Light-Emitting Diodes) are widely applied not only in decorative illumination but also in everyday lighting in buildings, flats, public areas, and automotive fields. These application areas often mean harsh environments, for example, regarding the humidity content of the surrounding air: besides outdoor and automotive illumination, even the household use cases (kitchen, bathroom, cellar) may represent extreme temperature and humidity variations (often reaching relative humidity levels close to 100%) for these devices; thus, their reliability behaviour in such circumstances should be better understood. Thermally activated processes were studied in several previous publications, but less information is available regarding high-humidity environmental tests. Moisture and temperature ageing tests with appropriate environmental parameter settings were performed as accelerated lifetime tests to investigate not only the effect of temperature but also that of humidity on the ageing and reliability of LED packages containing RGB (red green blue) chips and phosphor-converted white (pcW) LEDs. The ageing was followed not only through monitoring optical/electrical/spectral parameters but also with material analysis. Moisture–material interaction models were proposed and set up. It was found that humidity-accelerated ageing processes are more severe than expected from previous assumptions. RGB and pcW LEDs showed strongly different behaviour. Full article