Search Results (1,979)

Air-penetrating and noise-canceling constructions are required for numerous noise control issues. High ventilation performance conflicts with effective sound insulation, and vice versa. For this reason, ventilated noise barriers are currently being intensively researched and developed. One of the most popular solutions is the louvered-type barrier, whose acoustic efficiency depends on its geometric parameters as well as the acoustic properties of the louvers. One of the main challenges is optimizing the acoustic impedance of louver surfaces in order to achieve maximum reflection, absorption, or minimum transmission of sound waves. This paper proposes an analytical solution to the diffraction problem of a plane sound wave incident on a periodic array of similar thin screens with arbitrary impedance surfaces. An infinite system of linear equations is derived, and its numerical solution allows us to find the reflection and transmission coefficients. It has been shown that screens with reactive impedance are necessary to achieve maximum sound reflection. On the other hand, dissipative screens are required for minimal sound transmission. Additionally, the absorption properties of the array have been studied. It has been found that there is an optimal impedance value that provides the maximum absorption coefficient. Full article

Glass wool waste constitutes a rapidly increasing fraction of construction and demolition residues, yet it remains one of the most challenging insulation materials to recycle. Its non-combustible nature, extremely low bulk density, and high fibre elasticity preclude energy recovery and severely limit conventional mechanical recycling routes, resulting in long-term landfilling and loss of mineral resources. Converting glass wool waste into a fine mineral powder represents a potentially viable pathway for its integration into low-carbon construction materials, provided that industrial scalability, particle-size control, and chemical compatibility with cementitious binders are ensured. This study investigates the industrial-scale milling of end-of-life glass wool waste in a ventilated horizontal ball mill. It compares two grinding routes: a corundum-free route (BK) and an abrasive-assisted route (ZK) employing α-Al₂O₃ corundum to intensify fibre fragmentation. Particle size distribution was quantified by laser diffraction using cumulative and differential analyses, as well as characteristic diameters. The results confirm that abrasive-assisted milling significantly enhances fragmentation efficiency and reduces the coarse fibre fraction. However, the study demonstrates that this gain in fineness is inherently coupled with the incorporation of α-Al₂O₃ into the milled powder, introducing a chemically foreign crystalline phase that cannot be removed by post-processing. From a cement-oriented perspective, this contamination represents a critical limitation, as α-Al₂O₃ may interfere with hydration reactions, aluminate–sulfate equilibria, and microstructural development in Portland and calcium sulfoaluminate binders. In contrast, the corundum-free milling route yields a slightly coarser, chemically unmodified powder, offering improved process robustness, lower operational complexity, and greater compatibility with circular economy objectives. The study establishes that, for the circular reuse of fibrous insulation waste in cementitious systems, particle fineness alone is insufficient as an optimization criterion. Instead, the combined consideration of fineness, chemical purity, and binder compatibility governs the realistic and sustainable reuse potential of recycled glass wool powders. Full article

Civil defence shelters constitute an essential component of safety systems in emergency situations. The aim of this article is to assess the modernization potential of existing civil defence shelters in Poland, using a representative facility located in Olsztyn (Poland) as a case study. The analysis is based on a review of the current legal framework and identification of legislative gaps that affect the implementation of effective protective solutions. Within the case study, a detailed technical assessment of the protective structure was carried out, focusing on construction, protection against radiation and contamination, fire safety, and user ergonomics. Based on this assessment, a comparative analysis was performed between the surveyed facility and current as well as proposed technical requirements. The results revealed partial compliance with regulations while identifying significant deficiencies. To address these issues, measures such as replacing ventilation units with modern systems featuring automatic control, installing EI120-certified doors, improving emergency exit dimensions, and adding emergency lighting were proposed. Subsequently, risks associated with modernization were identified in accordance with ISO 31000. The findings highlight the need for systematic modernization of existing protective structures, clarification of legal regulations, and increased investment, which are key conditions for improving civilian safety. Full article

Introduction: Rectal colonization by carbapenemase-producing carbapenem-resistant Enterobacterales (CP-CRE) is a risk factor for subsequent infections, which are associated with high mortality rates. Methods: A cross-sectional study was conducted. Rectal swabs were collected from 297 patients within 48 h of admission to eight high-prevalence CP-CRE hospital departments, with follow-up swabs taken weekly for up to 4 weeks. Species identification, antimicrobial susceptibility testing, and genetic detection of carbapenemases were performed. The genetic relationship among isolates was assessed using ERIC-PCR, combined with epidemiological data, to investigate subsequent infections. Results: Fecal carriage of CP-CRE was detected in 15.5% (46/297) of patients- All carbapenemases were metallo-betalactamases, with dominance of NDM-producing Klebsiella pneumoniae. NDM + VIM-producing Escherichia coli were also detected. Among carriers, 26.1% were colonized by two different CRE species, and 86.9% had a history of prior hospitalization. Molecular analysis revealed clonal expansion, suggesting outbreaks among colonized patients. Additionally, 17.4% (8/46) of colonized patients developed an infection, which was significantly associated with urinary catheter use (p = 0.040), mechanical ventilation (p = 0.044), and surgical procedures (p = 0.040). Conclusions: rectal colonization by CP-CRE in hospitalized patients is a serious epidemiological concern, with evidence of clonal spread and subsequent infection in colonized patients. NDM-producing K. pneumoniae was also predominant, detecting co-production of NDM + VIM in E. coli. These findings underscore the urgent need to implement epidemiological surveillance cultures to improve the prevention and control of CP-CRE infections in Cuban hospitals. Full article

Background: Veno-venous extra-corporeal membrane oxygenation (ECMO) cannulations are mostly performed while patients are heavily sedated and mechanically ventilated. For patients with acute respiratory distress syndrome (ARDS), cannulating for ECMO while awake and spontaneously breathing, as well as treating without sedation and mechanical ventilation, has potential advantages. This study aimed to compare clinical outcomes between patients cannulated for ECMO while awake and patients cannulated while sedated and mechanically ventilated. Methods: A retrospective multicenter study. Data were accessed from the Israeli ECMO registry of patients with COVID-19-induced ARDS treated at eight ECMO centers in Israel. The study group comprised 24 patients who were cannulated while awake and spontaneously breathing. A control group comprised 96 patients who were cannulated after sedation and mechanical ventilation, matched 1:4 by age, sex, and body mass index. The primary outcome was six-month survival. Secondary outcomes were: the duration of ECMO therapy, the duration of invasive mechanical ventilation-free ECMO therapy, and the duration of invasive mechanical ventilation. Results: The mean age was 52 + 11 years; 78% were males. Fifteen patients (63%) in the study group were eventually intubated. The mean durations on ECMO and in the intensive care unit did not differ between the groups. The study group had a higher six-month survival (75% vs. 49%, p = 0.02) and fewer infectious complications such as pneumonia or bacteremia (21% vs. 40%, p < 0.001) compared to the control group. After adjusting for PO₂/FiO₂ ratio and for the COVID-19 variant, the hazard ratio was 0.45 (C.I 0.19–1.06, p = 0.069). Conclusions: Awake VV-ECMO cannulation in COVID-19-induced ARDS is feasible in selected patients and was associated with higher survival in unadjusted analyses. However, after adjustment for key covariates, this association was attenuated and did not reach statistical significance. Full article

To address the bottlenecks of low water and fertilizer utilization efficiency and limited yield potential inherent in Henan Province’s traditional winter wheat cultivation model of “furrow irrigation + conventional row seeding”, this study delved into the synergistic regulatory mechanisms of drip irrigation combined with wide-row precision seeding. It focused on their effects on the physiological ecology and yield-quality traits of winter wheat. A two-factor experiment, encompassing “sowing method × irrigation method” will be carried out during the 2024–2025 wheat growing season, featuring four treatments: furrow irrigation + conventional row seeding (QT), drip irrigation + conventional row seeding (DT), furrow irrigation + wide-row precision seeding (QK), and drip irrigation + wide-row precision seeding (DK). Results reveal that wide-row precision seeding optimized the canopy structure, raising the leaf area index (LAI) at the heading stage by 20.19% compared to QT, thereby enhancing ventilation and light penetration and reducing plant competition. Drip irrigation, with its precise water delivery, boosted the net photosynthetic rate of the flag leaf 35 days after flowering by 62.99% relative to QT, stabilizing root water uptake and significantly delaying leaf senescence. The combined effect of the two treatments (DK treatment) synergistically improved the canopy structure and photosynthetic performance of winter wheat, prolonging the functional period of green leaves by 29.41%. It established a highly efficient photosynthetic cycle, marked by “high stomatal conductance-low intercellular CO₂ concentration-high net photosynthetic rate”. The peak net photosynthetic rate (P_n) 13 days post-flowering rose by 23.9% compared to QT. Moreover, while reducing total water consumption by 21.4%, it substantially increased water use efficiency (WUE) and irrigation water use efficiency (IWUE) by 43.2% and 14.2%, respectively, compared to the QT control. Ultimately, the DK treatment achieved a synergistic enhancement in both yield and quality: grain yield increased by 14.7% compared to QT, wet gluten content reached 35.5%, and total protein yield per unit area rose by 13.1%. This study demonstrates that coupling drip irrigation with wide-row precision seeding is an effective strategy for achieving water-saving, high-yield, and high-quality winter wheat cultivation in the Huang-Huai-Hai region. This is achieved through the synergistic optimization of canopy structure, enhanced photosynthetic efficiency, and improved WUE. These findings provide a mechanistic basis and a scalable agronomic solution for sustainable intensification of winter wheat production under water-limited conditions in major cereal-producing regions. Full article

The increasing role of automation systems in energy-efficient buildings creates a need for simulation approaches that support standardized assessment already at the design stage. This paper presents a digital twin-based simulation framework that integrates building information modeling (BIM)-derived building data with MATLAB/Simulink models to enable regulation-oriented evaluation of building automation and control strategies. The proposed approach targets scenario-based analysis of automation maturity levels, covering conventional, advanced, and predictive configurations aligned with EN ISO 52120 and the Smart Readiness Indicator (SRI). A representative academic building model is used to demonstrate how the framework supports reproducible modeling of heating, ventilation, and air conditioning (HVAC), lighting, and shading control functions and enables consistent comparison of their energy-related behavior under unified boundary conditions. The results show that the framework effectively captures performance trends associated with increasing automation sophistication and reveals interaction effects between control subsystems that are not accessible in conventional energy simulation tools. The proposed methodology provides a practical and extensible foundation for early-stage, regulation-aligned evaluation of smart building solutions and for the further development of predictive and artificial intelligence (AI)-assisted control concepts. Full article

Background/Objectives: Pseudomonas aeruginosa is an opportunistic pathogen frequently implicated in healthcare-associated infections, particularly ventilator-associated pneumonia and other device-related infections. The global emergence of carbapenem-resistant P. aeruginosa (CRPA) represents a major clinical challenge due to its limited therapeutic options and high mortality rates. Methods: Relevant clinical data were obtained from medical records. Isolates were identified via 16S PCR, and antimicrobial susceptibility testing was performed using the Vitek2 Compact system following CLSI guidelines. Carbapenemase genes (blaGES, blaKPC, blaIMP, blaNDM, blaVIM) were detected via PCR. Clonal relationships were determined via RAPD-PCR, and some sequence types were assigned according to the global P. aeruginosa MLST database. Results: In this study, 40 non-duplicate CRPA isolates were collected from 35 patients in a tertiary-care hospital in Mexico. Most isolates originated from adult patients, predominantly from tracheal aspirates (32.5%) and urine cultures (25.0%). Mechanical ventilation was the most common invasive device associated with infection, and the overall mortality rate reached 14.3%. Antimicrobial susceptibility testing showed that 95% of isolates exhibited a multidrug-resistant phenotype, with high resistance rates to ciprofloxacin (70.0%) and β-lactams. Carbapenemase genes were detected in 55% of isolates, mainly bla_IMP, bla_GES, and bla_VIM, either alone or in combination. Notably, this is the first report of ST309 (bla_IMP), ST411 (bla_GES + bla_IMP), and ST167 (bla_GES + bla_VIM) carrying carbapenemase genes in Mexico. Conclusions: These findings highlight the persistence and genetic diversity of CRPA circulating in hospital settings and emphasize the urgent need for strengthened genomic surveillance and infection control programs to prevent the spread of these high-risk multidrug-resistant clones. Full article

Background/Objectives: The long-term impact of intubation during infancy or early childhood on later childhood or adolescence remains unclear. This study investigates the association between early-life intubation and subsequent mental health outcomes. Methods: We conducted a retrospective cohort study using nationwide data on children born in Korea between 2002 and 2005. Those who underwent intubation (exposed cohort) were compared with 1:10 matched unexposed controls who did not undergo intubation. Results: The exposed cohort (n = 18,799) had a significantly higher incidence rate of mental health disorders than controls (28.2 vs. 13.9 per 1000 person-years; HR 1.82, 95% CI 1.74–1.93). Autism spectrum disorder (HR 3.09) and attention-deficit/hyperactivity disorder (HR 1.61) increased in early childhood, while bipolar disorders (HR 2.36), schizophrenia spectrum disorders (HR 2.27), depressive disorders (HR 1.94) and anxiety disorders (HR 1.84) increased in adolescence. Higher incidence was noted in females, children not admitted to intensive care units, and those without congenital heart disease or bronchopulmonary dysplasia (p < 0.05). Hospitalization length correlated with mental health outcomes (p < 0.001), but ventilator duration did not (p = 0.694). Conclusions: Early-life intubation is associated with an increased risk of mental health disorders, highlighting the need for long-term follow-up and support for these children. In particular, increased clinical awareness is needed during follow-up care for patients at higher risk, such as females, children without congenital heart disease or bronchopulmonary dysplasia, those intubated at an older age, and those with longer hospitalizations. Full article

This study develops an explainable reinforcement learning (RL) control framework for hybrid ventilation in Mediterranean office buildings to enhance thermal comfort, energy efficiency, and long-term climate resilience. A working environment was created Using EnergyPlus to represent an office test cell equipped with natural ventilation and air conditioning. The RL controller, based on Proximal Policy Optimization (PPO), was trained exclusively on present-day Typical Meteorological Year (TMY) data from Beirut and subsequently evaluated, without retraining, under future 2050 and 2080 climate projections (SSP1-2.6 and SSP5-8.5) generated using the Belcher morphing technique, in order to quantify robustness under projected climate stressors. Results showed that the RL control achieved consistent, though moderate, annual HVAC energy reductions (6–9%), and a reduction in indoor overheating degree (IOD) by about 35.66% compared to rule-based control, while maintaining comfort and increasing natural ventilation hours. The Climate Change Overheating Resistivity (CCOR) improved by 24.32%, demonstrating the controller’s resilience under warming conditions. Explainability was achieved through Kernel SHAP, which revealed physically coherent feature influences consistent with thermal comfort logic. The findings confirmed that physics-informed RL can autonomously learn and sustain effective ventilation control, remaining transparent, reliable, and robust under future climates. This framework establishes a foundation for adaptive and interpretable RL-based hybrid ventilation control, enabling long-lived office buildings in Mediterranean climates to reduce cooling energy demand and mitigate overheating risks under future climate change. Full article

Heating, ventilation, and air-conditioning (HVAC) systems dominate energy consumption in hot-climate buildings, where maintaining occupant comfort under extreme outdoor conditions remains a critical challenge, particularly under emerging time-of-use (TOU) electricity pricing schemes. While deep reinforcement learning (DRL) has shown promise for adaptive HVAC control, existing approaches often suffer from comfort violations, myopic decision making, and limited robustness to uncertainty. This paper proposes a comfort-first hybrid control framework that integrates Soft Actor–Critic (SAC) with a Cross-Entropy Method (CEM) refinement layer, referred to as SACEM. The framework combines data-efficient off-policy learning with short-horizon predictive optimization and safety-aware action projection to explicitly prioritize thermal comfort while minimizing energy use, operating cost, and peak demand. The control problem is formulated as a Markov Decision Process using a simplified thermal model representative of commercial buildings in hot desert climates. The proposed approach is evaluated through extensive simulation using Saudi Arabian summer weather conditions, realistic occupancy patterns, and a three-tier TOU electricity tariff. Performance is assessed against state-of-the-art baselines, including PPO, TD3, and standard SAC, using comfort, energy, cost, and peak demand metrics, complemented by ablation and disturbance-based stress tests. Results show that SACEM achieves a comfort score of 95.8%, while reducing energy consumption and operating cost by approximately 21% relative to the strongest baseline. The findings demonstrate that integrating comfort-dominant reward design with decision-time look-ahead yields robust, economically viable HVAC control suitable for deployment in hot-climate smart buildings. Full article

This study explores the intersection of sociocultural factors, particularly privacy, with energy consumption patterns in residential buildings in Riyadh, Saudi Arabia. While cultural values around privacy have long been recognised as influential in residential design, the impact of these values on energy consumption is underexplored. This research aims to fill this gap by examining how privacy needs, residents’ preferences, and open layouts affect energy efficiency, particularly in terms of natural light and ventilation. A mixed-methods approach was employed, including semi-structured interviews with engineers, data collected from 108 respondents via an online survey, a case study of a residential building in Riyadh, and building performance simulations using IES software. The study also assessed actual energy consumption data and indoor lighting as potential implications of privacy concerns, causing changes in behavioural control of systems (e.g., windows, blinds, lighting, etc.). It focuses on the relationship between privacy needs, energy use, and natural daylight distribution. The IES simulation results for the studied residential building show an annual energy consumption of 24,000 kWh, primarily due to cooling loads and artificial lighting caused by privacy measures applied by the residents. The findings reveal that privacy-driven design choices and occupant behaviours, such as the use of full window shutters, frosted glazing and limited window operation, significantly reduce daylight availability and natural ventilation, leading to increased reliance on artificial lighting and air conditioning. This study highlights the need for human-centric design approaches that address the interplay between sociocultural factors, particularly reinforcing cultural sensitivity, and building performance, offering insights for future sustainable housing developments in Riyadh and similar contexts. Full article

Mosque buildings have symbolic significance, which makes them ideal candidates for implementing energy-efficient building design strategies. Mosques located in hot climates face several challenges in achieving thermal comfort while meeting energy efficiency requirements due to their distinct architectural features and intermittent occupancy patterns. Addressing these challenges requires integrating innovative energy-efficient retrofit strategies that cater to the characteristics of existing contemporary mosque buildings. Thus, this study provides a review of these approaches, considering both passive and active strategies. Passive strategies include thermal insulation, glazing upgrades, and shading improvements, while active ones include Heating, Ventilation, and Air Conditioning (HVAC) zoning and smart control, lighting upgrades, and the integration of photovoltaic panels. The findings highlight the potential of combining both passive and active retrofitting measures to achieve substantial energy performance improvements while addressing the thermal comfort needs of mosque buildings in hot climates. However, more research is needed on smart control systems and advanced building materials to further enhance energy performance in mosque buildings. By adopting these strategies, mosques can serve as models of energy-efficient design, promoting sustainability and resilience in their communities. Full article

Fire accidents in road tunnels can cause a significant number of fatalities and severe damage to tunnel structures. The tunnel European directive applies to the trans-European road network and requires the use of active smoke control systems in most tunnels longer than 1000 m. Research has investigated whether shorter tunnels without active smoke control systems are safe. If smoke contaminates the lower layer where people evacuate, it can impair visibility. This disturbs egress and may cause intoxication and, eventually, death. The FireFoam computer code was applied to the Memorial Tunnel fire ventilation tests for validation. This work investigates the effect of varying the heat release rate (HRR), ranging from 6 to 100 MW, under a wind velocity of 0.77 m/s and in the absence of wind. Results show that high HRR moves the start of lower layer smoke contamination closer to the fire source, reducing the distance from 390 m at 14 MW to as close as 210 m at 100 MW. An analytical model was developed to predict the distance from the fire source where smoke can contaminate the lower layer and was subsequently improved to account for HRR variation. Full article

Existing office buildings in Australia contribute to 24% of the nation’s electricity consumption and 10% of greenhouse gas emissions, with energy use projected to rise by 84%. Meeting the 2050 sustainability target and United Nations (UN) 17 Sustainable Development Goals (SDGs) requires improving sustainability within existing office buildings. This systematic review examines net zero energy and climate resilience strategies in these buildings by analysing 74 studies from scholarly literature, government reports, and industry publications. The literature search was conducted across Scopus, Google Scholar, and Web of Science databases, with the final search in early 2025. Studies were selected based on keywords and research parameters. A narrative synthesis identified key technologies, evaluating the integration of net zero principles with climate resilience to enhance energy efficiency through HVAC modifications. Technologies like heat pumps, energy recovery ventilators, thermal energy storage, and phase change materials (PCMs) have been identified as crucial in reducing HVAC energy usage intensity (EUI). Lighting control and plug load management advancements are examined for reducing electricity demand. This review highlights the gap between academic research and practical applications, emphasising the need for comprehensive field studies to provide long-term performance data. Current regulatory frameworks influencing the net zero transition are discussed, with recommendations for policy actions and future research. This study links net zero performance with climate adaptation objectives for existing office buildings and provides recommendations for future research, retrofit planning, and policy development. Full article