Rapid situation assessment in disaster affected locations and harmful environments is important, as direct human access to these locations can be dangerous and alarming. In order to provide live visual feedback and on-site environmental data collection, this paper presents a low-cost, mobile environmental monitoring system based on the ESP32-CAM module. The system combines live video streaming with gas monitoring using an MQ-135 sensor and temperature-humidity measurement using a DHT22 sensor. Temperature values ranging from 31.0 to 56.5 °C and humidity levels ranging from 94
Access to healthcare in Cameroon is constrained not only by limited supply continuity but also by site-dependent power-quality (PQ) exposure affecting sensitive biomedical and hospital electrical loads. In this context, this paper presents a field-based, multi-site PQ assessment conducted in four Cameroonian hospitals (Djoum, Obala, Ad Lucem Bafang, and Biyem-Assi), combining steady-state PQ indicators (frequency, voltage unbalance VUF, total harmonic distortion THD, voltage fluctuations) with event-based analysis of voltage dips. Each dip is characterized in the magnitude–duration plane and interpreted using the ITIC tolerance envelope. Beyond standard reporting (event counts, severity classes, and threshold exceedances), we introduce a distinct site-level metric: the ITIC-Severity Exposure Index (ITIC-SEI). Unlike generic sag indices that compress events into a single number without preserving the ITIC-based tolerance meaning, ITIC-SEI is derived directly from the dip magnitude–duration class matrix and uses a simple monotone weighting to quantify cumulative exposure to ITIC-relevant severity. We also report an out of tolerance rate (pout) as the fraction of dips falling outside the ITIC tolerance region, and we assess robustness through sensitivity tests on thresholds and monotone weight variants. Results show strong spatial variability, with Djoum exhibiting orders-of-magnitude more disturbances than Biyem-Assi, and multiple indicators exceeding commonly used guideline ranges (EN 50160, IEC 61000-2-2, IEEE 519-2014). The proposed ITIC-SEI and pout provide an interpretable severity mapping to support hospital-level prioritization of mitigation and maintenance actions.
Hydrogen is widely promoted as a low-carbon energy carrier; however, leakage from production, transport, and storage infrastructure can undermine its environmental benefits through indirect and cumulative effects. Unlike conventional pollutants, hydrogen does not exhibit toxicity or environmental persistence. Nevertheless, hydrogen leakage results in energy losses, increased hydrogen production requirements, accelerated infrastructure repair and replacement, and additional emissions arising from system-level interactions. This study develops a probabilistic framework to quantify the carbon footprint associated with hydrogen leakage by integrating leak occurrence frequency, released hydrogen mass, and multiple environmental impact pathways. Leak scenarios are classified by size and equipment type, and operational factors such as detection and isolation performance are explicitly represented. A numerical case study shows that small leaks, while individually insignificant, can dominate the expected annual carbon footprint due to their high frequency, whereas rare large leaks contribute less overall because of their lower probability of occurrence. The results indicate that conventional life-cycle assessment approaches may underestimate the environmental impacts of hydrogen systems by neglecting probabilistic leakage behavior and operational inefficiencies. The proposed framework provides a practical method for incorporating hydrogen leakage into environmental assessments and highlights the importance of design, inspection, maintenance, and operational management in achieving genuinely low-carbon hydrogen systems.
In many real-world networks, complete structural information is often unavailable due to privacy, data collection limits, or constant changes. This makes it challenging to identify important nodes using standard centrality measures, which usually assume full network knowledge. In this study, we evaluate the robustness of seven widely-used centrality methods–Betweenness, Closeness, K-shell, Katz, Eigenvector, PageRank, and VoteRank–as representatives from different categories: global, local, meso-scale, iterative path-based, and voting-based centrality. We simulate incomplete networks using snowball sampling with varying diameters, creating sub-networks of differing degrees of completeness, and compare node rankings with the original networks using Kendall’s rank correlation, Spearman’s rank correlation and Jaccard Similarity. Our results show which centrality measures remain reliable under partial visibility and how incompleteness affects their effectiveness. These insights can guide the choice of centrality metrics in areas such as epidemiology, infrastructure planning, and social network analysis. Moreover, in scenarios where approximate rankings are sufficient, our findings allow for reduced computational effort with minimal loss in accuracy.
The principal cause of many moment-resisting frame buildings' collapse during recent earthquakes is the shear failure of exterior beam-column joints (BCJ). Nowadays, significant research has been conducted to promote and understand the fibre-reinforced polymer application externally. The main objective is to investigate the effectiveness of glass fibre polymeric material use in reinforced concrete BCJs to enhance their performance. This study combines experimental investigation and finite element analysis to evaluate the effectiveness of GFRP wrapping configurations. In the testing program, Chopped Strand Mat (CSM) (Emulsion) and Woven Rovings (WR) were the two glass fibre polymer materials used to strengthen BCJs. Four different types of enhancing patterns were used in this strengthening protocol. These are Single Wrapping (SW), Single Wrapping Diagonal (SWD), Double Wrapping (DW), and Double Wrapping Diagonal (DWD) patterns. The diagonal wrapping pattern enhanced the load-carrying capacity more effectively, as demonstrated by the experimental results. A similar trend was observed in the experimental and finite element (FE) analyses for damage prediction and load–deflection behaviour. Hence, this hybrid approach with a conventional steel bar and Diagonal wrapping CSM (Emulsion) can be used to improve the structural performance under monotonic loading of RC BCJs with excellent ductile behaviour.
