Search Results (2,020)

Swimming is one of the most popular forms of recreational sport worldwide, recommended for people of all ages as a healthy activity. While numerous studies have focused on the impact of indoor air quality on the health of pool users, relatively few have addressed how specific airborne parameters in indoor swimming facilities affect the durability of construction materials. This article analyzes the current state of knowledge on the influence of the pool indoor environment on structural reliability, with trichloramine (NCl₃) emphasized as a degradation factor. Indoor pool environments are classified as chemically aggressive, due to elevated air temperature (~30 °C), high humidity (often exceeding 60%), and the presence of volatile chlorine compounds released from disinfected water. Our case study demonstrates that during swimming competitions, the average concentration of airborne NCl₃ reached a value of 900 µg/m³, with peaks up to 1200 µg/m³, i.e., about ten times higher than on typical usage days. The median trichloramine concertation during the competition was 1071 µg/m³. Such exposure conditions accelerate corrosion processes in stainless steels and other building materials, reducing service life and requiring targeted monitoring and preventive maintenance. Based on the findings, recommendations are provided regarding material selection, highlighting the importance of surface texture, ventilation strategies, and protective measures tailored to periods of intensive facility use. Full article

Silica fume (SF) is extensively utilized for enhancing concrete properties. This study examines the impact of SF dosage on concrete frost resistance. Specimens were produced by replacing cement with SF at 5%, 10%, 20%, and 30% ratios. Mechanical testing and microscopic characterization measured variations in mass loss, relative dynamic elastic modulus, flexural strength, hydration products, and pore structure. Digital image correlation tracked failure development during flexural tests. Results indicated that SF-modified concrete showed lower mass loss, better elastic modulus retention, and improved flexural strength maintenance compared to plain concrete after identical freeze–thaw (F-T) cycles. Additionally, SF-modified concrete demonstrated reduced crack widths and slower crack expansion during bending. The 10% SF mixture, after 300 cycles, achieved optimal results characterized by 2.83% mass loss, 88.1% relative dynamic modulus, and only a 17% flexural strength reduction. Microscopic studies confirm that SF addition increases calcium silicate hydrate formation, decreases calcium hydroxide levels, and refines pore structure with higher density. These modifications enhance frost resistance. A service-life prediction model using gray model approach methodology projected that 10% SF concrete would last 2.01 times longer than unmodified concrete under F-T exposure. Full article

With the widespread deployment of high-voltage and ultra-high-voltage transmission lines, composite insulators play a vital role in modern power systems. However, prolonged service leads to material aging, and the current lack of standardized, quantitative methods for evaluating silicone rubber degradation poses significant challenges for condition-based maintenance. To address this measurement gap, we propose a novel aging assessment framework that integrates Fourier Transform Infrared (FTIR) spectroscopy with a measurement-oriented ensemble learning model. FTIR is utilized to extract absorbance peak areas from multiple aging-sensitive functional groups, forming the basis for quantitative evaluation. This work establishes a measurement-driven framework for aging assessment, supported by information-theoretic feature selection to enhance spectral relevance. The dataset is augmented to 4847 samples using linear interpolation to improve generalization. The proposed model employs k-nearest neighbor (KNN), Support Vector Machine (SVM), Random Forest (RF), and Gradient-Boosting Decision Tree (GBDT) within a two-tier ensemble architecture featuring dynamic weight allocation and a class-balanced weighted cross-entropy loss. The model achieves 96.17% accuracy and demonstrates strong robustness under noise and anomaly disturbances. SHAP analysis confirms the resistance to overfitting. This work provides a scalable and reliable method for assessing silicone rubber aging, contributing to the development of intelligent, data-driven diagnostic tools for electrical insulation systems. Full article

As an advanced form of community development, Future Communities (Weilai Shequ) is a policy-led urban initiative launched in Zhejiang, China, that prioritizes human-centered development. However, it is currently confronted with an inherent contradiction: the expansion of technological rationality is encroaching upon humanistic values. Centering on the core “technology–human” relationship, this study is dedicated to exploring development measures for Future Community that synergistically integrate technological empowerment and humanistic care. Using natural language processing techniques (LDA topic modeling), we conducted an exploration and analysis of the thematic characteristics and evolution of 40 policy documents related to future communities issued by the central and local governments of China from 2014 to 2024. The study identifies six core topics: Quality Enhancement, Technical Foundation, Intelligent Operations and Maintenance, Green and Low-Carbon, All-Age Friendliness, and Community Services. Analysis revealed that each theme embodies a dual connotation of both technological and humanistic dimensions. Furthermore, the study revealed that the evolution of policy semantics follows a three-stage developmental pattern: technology dominance and nascent human-centered values; human-centered rise and technology empowerment; and human-centered deepening and technological embeddedness. Based on the above findings, and grounded in a phenomenological perspective, this study integrates Alexander’s human-centered architectural philosophy with Ihde’s theory of technological mediation to propose a future community construction pathway jointly driven by “technological mediation” and “human presence.” Theoretically, this research transcends the binary narrative of technology versus humanism. In practice, it provides policymakers with tools to avoid technological pitfalls. It establishes fundamental principles for planners and designers to implement humanistic values, ultimately aiming to realize, at the community level, the vision of technology serving humanity’s aspiration for a better life. Full article

A new criticality indicator for Water Distribution Networks (WDNs) is presented. The new indicator is based on the minimum pressure (MP) model, which relies on the assumption that air can enter the pipes, e.g., when failure occurs in water scarcity scenarios, and maintain a minimum pressure equal to zero in the whole network. The proposed indicator properly integrates topological features, provided by structural hole theory, with the hydraulic constraints provided by the WDN steady-state solution, with a particular focus on pipes where occurring free surface flow leads to a serious reduction in the quality of the network service. The new indicator leads to a new criterion for the prioritized maintenance of pipes in existing networks, as well as for the design and planning of new ones, which is different from the one derived from other popular indicators. Three real-life WDNs are selected as test cases. Full article

Punta Carola beach, located on San Cristóbal Island in the Galápagos Archipelago, exemplifies how island environments of recent human settlement can rapidly acquire cultural significance. Drawing on a survey of 201 residents, this study examines perceptions of the ecosystem services provided by Punta Carola, their relationship to subjective wellbeing, and attitudes toward alternative tourism and governance strategies. The findings reveal that the inhabitants of San Cristóbal recognize a wide range of tangible and intangible benefits that the natural environment of Punta Carola contributes to their quality of life, sense of belonging, and cultural identity, as well as recreational and aesthetic values. Life satisfaction was positively associated with perceptions of nature’s contribution, the maintenance of local ecological knowledge, and household income, while formal education correlated negatively. Residents identified freshwater and artisanal fishing as the most critical ecosystem services, reflecting their centrality to local livelihoods and wellbeing. The results also underscore widespread criticism of large-scale tourism projects perceived as exclusionary or unsustainable and highlight the importance of participatory governance schemes that legitimize local values. Punta Carola thus emerges as a “cultural landscape of resistance”, where external pressures catalyze identity construction and territorial rootedness. This case contributes to academic debates on socio-ecological resilience in fragile island contexts and offers actionable insights for inclusive planning in the Galápagos. Full article

Lithium is the first-line treatment for bipolar disorders and a first-line augmentation option for treatment-resistant unipolar depression. Due to its narrow therapeutic window and risk of toxicity, people taking lithium require regular blood testing to monitor lithium levels in the body. However, studies have reported that only half of lithium-treated patients receive adequate lithium monitoring. This protocol describes a trial that will test the feasibility and acceptability of a point-of-care (POC) lithium blood testing programme in patients with unipolar or bipolar affective disorders taking lithium as a maintenance treatment. The primary objectives are to establish whether testing the effectiveness of POC testing is feasible, by assessing recruitment, attrition, and adherence to monitoring guidelines compared to participants randomised to testing as usual; to test whether the programme is acceptable to patients; and to measure potential contamination bias. The secondary objectives are to examine changes in health-related quality of life, the use of healthcare services, and depressive and manic symptoms to inform the design of a larger multi-site randomised controlled trial (RCT). This feasibility RCT will recruit 80 participants with affective disorders who are taking lithium. Participants will be 1:1 randomised to either POC monitoring or monitoring as usual where they will be followed up at three research visits over 30 weeks. The proportion of patients meeting guidelines for lithium monitoring will be examined, alongside measures of acceptability, wellbeing, and health economic data. POC testing has the potential to significantly improve patient safety and satisfaction with lithium treatment. Full article

High nature value (HNV) grasslands in mountain areas are important ecosystems for biodiversity maintenance and offer a multitude of ecosystem services, but they are constantly threatened by abandonment or intensive fertilization. The aim of this study was to assess the effects of organic and mineral fertilization, under mulching and abandonment scenarios, on the floristic composition and diversity of Nardus stricta-dominated grasslands located in the North-Eastern Carpathians (Romania). The field experiment included 11 variants (control, low, moderate, and high inputs), analyzed as communities with cluster, ordinations, indicator species, and α indices. The results showed a clear separation of communities along the input gradient, from the oligotrophic grassland dominated by Nardus stricta (control variant) to mesotrophic/eutrophic communities dominated by Dactylis glomerata, Festuca pratensis, and Trifolium pratense at moderate and high inputs. Moderate fertilization (10–20 t ha⁻¹ manure; N₅₀P₅₀K₅₀–N₁₀₀P₁₀₀K₁₀₀) maximized species richness (37–38 species), Shannon diversity (H′ = 2.5–2.6), and evenness (E = 0.70–0.75). High inputs reduced diversity and favored competitive grasses. Indicator species analysis highlighted a multitude of species that show the plant communities’ response to adaptive management. Moderate fertilization provides a viable trade-off between productivity and biodiversity, while abandonment or overfertilization accelerates biodiversity loss. Full article

This study evaluates the applicability of Sentinel-1 Persistent Scatterer Interferometry (PSI) data from the Ground Motion Service Germany (BBD) for monitoring dams by comparing it with terrestrial measurements at dams of the Ruhrverband in North Rhine-Westphalia (NRW), Germany. The analysis focuses on the accuracy and reliability of BBD data in detecting movements, considering two observation periods and two satellite observation geometries (Ascending and Descending orbit). BBD data showed high correlations with in situ measurements, particularly for long-term deformation trends. However, weak correlations are observed, especially in the Ascending direction. These inconsistencies highlight the influence of structural characteristics of the dams, observation conditions like incidence angles and changes of the study period on data reliability. Key findings show that BBD data provides valuable insights for observing long-term deformation trends (r up to 0.7) but has limitations in capturing short-term deformations due to its annual update rate. A clear difference was observed when extending the observation period by one year, from 2015–2020 to 2015–2021: although the number of PS (Persistent Scatterers) decreased by up to 60%, the PS showed an improved agreement with in situ measurements, indicating higher data quality (r up to 0.8). However, the precision of BBD data depends on inherent factors from the PSI method such as the satellites’ observation geometry, observation period, and site-specific conditions, underscoring the importance of tailored feasibility assessments. The BBD offers a complementary tool to support the maintenance and safety of dam infrastructures. The study follows an observational multi-site design with predefined, DIN-aligned evaluation criteria and statistical tests and is intended as an assessment of operational support rather than a full operational qualification, outlining conditions under which BBD PSI can complement standards-aligned monitoring. Full article

Objective: To identify facilitating and hindering factors for implementing a care transition strategy for adult patients undergoing elective colorectal cancer surgery, within a primary health care (PHC) context, addressing gaps in the literature on implementation challenges and contextual factors influencing such strategies. Methods: This complex mixed methods study combined a randomized clinical trial (RCT) and a qualitative component within an Implementation Research framework. The RCT enrolled adult patients with colorectal cancer, while the qualitative phase included a multilevel sample of participants. Iterative data integration occurred throughout the planning, implementation, and evaluation phases. The intervention was assessed using the RE-AIM (Reach, Efficacy, Adoption, Implementation, Maintenance) framework. Statistical analyses were conducted using IBM SPSS Statistics 22.0, applying descriptive and inferential methods. Results: Our findings revealed that the adoption of the intervention was satisfactory; however, Reach, Efficacy, and Implementation were not achieved. Facilitating factors included recognition of the potential of the care transition strategy to improve patient outcomes, and the intervention’s feasibility, replicability, and low cost. The main hindering factors identified included poor communication between care levels, inadequate material resources, and high workload. Integration of qualitative insights helped explain the limited quantitative impact, highlighting contextual challenges during the COVID-19 pandemic. Conclusions: The care transition strategy was well accepted by participants and health care providers, demonstrating potential to strengthen continuity of care between hospital and PHC services. Nonetheless, significant organizational and resource-related barriers hindered its effectiveness. Future studies are required to adapt transitional care models to overcome communication gaps, optimize resource allocation, and enhance implementation in similar settings. Full article

In the context of increasing demands for the reliability and efficiency of electrical complexes and systems, the problem of assessing and monitoring the technical condition (TC) of electrical equipment is becoming particularly relevant. This review is devoted to a comprehensive analysis of the factors affecting the performance of electrical equipment and modern methods for diagnosing its TC. The review article examines in detail the impact of various operational factors, including climatic conditions (temperature fluctuations, humidity, contamination) and electrical equipment operating modes. Special attention is paid to modern methods of technical diagnostics, such as thermographic diagnostics, vibration diagnostics, and chromatographic analysis of dissolved gases, which make it possible to identify defects and predict failures at early stages of their development. A significant part of the review is devoted to modern approaches to predicting the durability indicators of electrical equipment using mathematical modeling and neural networks. The advantages of a condition-based maintenance (CBM) and repair strategy, based on assessing the actual TC of the equipment, are analyzed in detail and compared with the strategy of scheduled preventive maintenance. This review particularly emphasizes the importance of integrating digital technologies, including the internet of things (IoT), digital twins (DT), and intelligent diagnostic monitoring systems, to create effective systems for predicting and managing TC. The review demonstrates that a comprehensive consideration of the actual TC of electrical equipment and its operating conditions can significantly increase the reliability of power systems, optimize maintenance and repair costs, and extend the service life of electrical equipment under various intensities of impacting operational factors. Full article

The Baltic Sea has become a strategic energy corridor for Poland and Central and Eastern Europe. It illustrates the dual challenge of maintaining short-term energy security while advancing long-term decarbonization. This paper investigates the role of Polish ports as critical nodes in this transformation. Using a qualitative and exploratory research design that combines policy analysis, secondary data, and case studies of oil, gas, and offshore wind facilities, the study shows how large ports consolidate their roles as gateways for fossil fuel diversification, while smaller ports are integrated into the offshore wind supply chain as service and maintenance bases. The analysis highlights the interdependence between European and national policy frameworks (REPowerEU, TEN-E, PEP2040) and port development, demonstrating how institutional conditions shape infrastructural resilience. At the same time, geopolitical risks and subsea vulnerabilities underline the necessity of treating ports as critical infrastructure requiring reinforced protection. The paper concludes that Polish ports act simultaneously as guarantors of immediate energy resilience and enablers of renewable transition, positioning the Baltic Sea as a cornerstone of Europe’s evolving energy architecture. Full article

The building and municipal facility sectors in many countries are shifting from rapid construction to a balanced focus on construction and operation & maintenance (O&M). However, O&M practices remain largely manual, with poor digital integration, fragmented data management, and inconsistent performance standards. The absence of a unified theoretical and standardization framework for intelligent O&M represents a critical research and practice gap. To address this, this paper proposes a comprehensive framework for intelligent O&M standards, grounded in operations management theory and supported by extensive research. The framework is structured across three dimensions: (a) functional services, including perception, data fusion, decision-making, and disaster prevention; (b) system hierarchy, ranging from perception layer and algorithm layer to human–computer interaction layer; and (c) intelligence characteristics, spanning presentation and monitoring to autonomous maintenance. In addition, existing standards and representative applications are reviewed to provide valuable references for the future development of intelligent O&M standard systems. Full article

Gas station canopy grid structures develop local damage during service life, necessitating regular inspection and maintenance to prevent structural collapse. However, conventional field inspection remains inefficient and highly dependent on manual operation. This paper proposes a time domain response sensitivity methodology for damage assessment of structural members in gas station canopy grid structures. The proposed methodology advances time-domain sensitivity analysis to handle spatially complex grid structures with dense spectral characteristics, while proposing a calculation method for implementing intelligent sensing technology in field inspections that enables automated damage localization in practical canopy structures. Through analyzing time domain response sensitivity matrix, an optimal sensor placement method for spatial grid structures is presented. A double-layer spatial grid structure model is constructed to validate the time domain response sensitivity damage identification method and the optimal sensor placement method based on sensitivity analysis. The results show that the time domain response sensitivity damage identification method identifies the member damage in gas station canopy grid structural numerical model with satisfactory accuracy and efficiency, the optimal sensor placement methodology is suitable for damage identification of structural members. Full article

Recirculating Aquaculture Systems (RAS) represent a high-density, controlled-environment fish farming method that requires constant monitoring of critical water quality parameters to ensure high water quality and fish stock health. Manual monitoring is labor-intensive and prone to error, creating a significant risk of catastrophic loss. This work presents the design and implementation of an automated monitoring system built on a Raspberry Pi platform that integrates multiple sensors (temperature, pH, conductivity, water level, and pumps’ functionality) to provide continuous, real-time data acquisition. A key feature is a software-based outlier rejection algorithm that enhances data integrity, and the code is freely available on the GitHub platform for further development. The collected data has been published on the ThingsBoard IoT platform for visualization and historical analysis via the HTTPS protocol. Furthermore, the system implements a proactive alerting mechanism using the Pushover notification service to deliver instant mobile alerts when parameters deviate from predefined thresholds. Commercial solutions cost in the order of thousands of euros, have high maintenance and operational costs, and pose integration and compatibility challenges. This solution provides a reliable, scalable, and cost-effective method for maintaining optimal conditions in a RAS, with hardware costs of less than EUR 150. Full article