Search Results (675)

This review provides a comprehensive and critical analysis of geopolymers, focusing on structure–property relationships and functionalization strategies for sustainable applications. A structured narrative review methodology was adopted, following PRISMA principles, based on literature retrieved from Web of Science, Scopus, ScienceDirect, and MDPI databases, primarily covering the period 2015–2025. The influence of precursor type, alkaline activators, and Si–Al ratio on reaction kinetics, microstructure, porosity, and mechanical performance is systematically discussed. Functionalization approaches using additives are critically reviewed with respect to durability, fire resistance, photocatalytic activity, and antibacterial performance. The analysis highlights that the geopolymer matrix primarily acts as stable and versatile support, while functional performance is governed by the controlled integration of active particles. Key limitations related to the variability of raw materials, lack of standardization, and long-term durability are identified. Future research directions are outlined, emphasizing the need for standardized processing protocols and the application-oriented design of multifunctional geopolymer systems. Full article

Sok Chan Forest, located in Lao Suea Kok District, Ubon Ratchathani Province, Thailand, is frequently affected by wildfires during the dry season, resulting in significant environmental degradation and adverse impacts on the livelihoods of local communities. In this study, we outline the development of a prototype wildfire early warning system utilizing LoRa technology to address the long-distance data transmission limitations that are commonly encountered when using conventional Internet of Things (IoT) solutions. The proposed system comprises sensor nodes that communicate from peer to peer with a central node, which subsequently relays the collected data to a remote database server via the internet. Real-time alerts are disseminated through both a smartphone application and a web-based platform, thereby facilitating timely notification of authorities and community members. Field experiments in Sok Chan Forest demonstrated reliable single-hop communication with a 100% packet delivery ratio at distances up to 1500 m, positive SNR, and RSSI levels above receiver sensitivity, as well as sub-second end-to-end detection latency in both single- and two-hop configurations. A controlled alarm accuracy evaluation yielded an overall classification accuracy of 91.7%, with perfect precision for the Fire class, while a user study involving five software development experts and fifteen firefighters yielded an average effectiveness score of 3.84, reflecting a high level of operational efficacy. Full article

Large-eddy simulation (LES) within a weather research and forecasting (WRF) model coupled with an active scalar transport equation was used to simulate Atmospheric Boundary Layer conditions during the Mosquito fire, the largest wildland fire in California during September 2022. The simulations were conducted with realistic boundary conditions derived from the National Oceanic and Atmospheric Administration (NOAA) High Resolution Rapid Refresh (HRRR) model, with the aim of better understanding the two-way coupling between the ABL and plume dynamics. The terrain was extremely inhomogeneous, and the topography varied significantly within the numerical domain. Initially, LES of the smoke-free ABL was conducted on nested domains, and detailed ABL data were gathered from 8 to 9 September 2022. LES simulations were validated using four Automated Surface Observing System (ASOS) stations and NOAA meteorological (MET) observations, as well as NOAA met Twin Otter measurements, and the desired accuracy was established. The smoke plume was then released into the ABL at noon on 9 September 2022, and the plume simulations were conducted for a period of one hour following the release. During this period, the ABL transitioned from convective to buoyancy-shear-driven regimes. Late-night and early-morning conditions are influenced by the complex topography and low-level jet, whereas buoyancy and shear control the ABL dynamics during the morning and afternoon hours. The plume vertical transport is influenced by the ABL depth and the size of the vertical turbulence structures during that time, whereas the wind conditions and turbulent kinetic energy within the ABL dictate the horizontal transport scales of the plume. In addition, the results demonstrate that the plume modifies the microclimate along its path. Full article

Refuse-derived fuel (RDF) presents a viable strategy to concurrently address the challenges of municipal solid waste management and the need for alternative energy. In this context, the present review systematically synthesizes recent advances in RDF preparation, combustion behavior, and efficient utilization technologies. The study examines the full chain of RDF production—including waste selection, mechanical/optical/magnetic sorting, granulation, briquetting, and chemical modification—highlighting how pretreatment technologies influence fuel homogeneity, calorific value, and emissions. The thermochemical conversion characteristics of RDF are systematically analyzed, covering the mechanism differences among slow pyrolysis, fast pyrolysis, flash pyrolysis, pyrolysis mechanisms, catalytic pyrolysis, fragmentation behavior, volatile release patterns, and kinetic modeling using Arrhenius and model-free isoconversional methods (e.g., FWO). Special attention is given to co-firing and high-efficiency combustion technologies, including ultra-supercritical boilers, circulating fluidized beds, and rotary kilns, where fuel quality, ash fusion behavior, slagging, bed agglomeration, and particulate emissions determine operational compatibility. Integrating recent findings, this review identifies the key technical bottlenecks—feedstock variability, chlorine/sulfur release, heavy-metal contaminants, ash-related issues, and the need for standardized RDF quality control. Emerging solutions such as AI-assisted sorting, catalytic upgrading, optimized co-firing strategies, and advanced thermal conversion systems (oxy-fuel, chemical looping, supercritical steam cycles) are discussed within the broader context of carbon reduction and circular economy transitions. Overall, RDF represents a scalable, flexible, and high-value waste-to-energy pathway, and the review provides insights into future research directions, system optimization, and policy frameworks required to support its industrial deployment. Full article

Pheromone-mediated chemical communication plays a central role in shaping the social organization and ecological success of S. invicta, a globally invasive eusocial insect characterized by a highly developed semiochemical signaling system. This review summarizes recent advances in the chemical ecology of S. invicta, with emphasis on the putative ecological roles of major pheromone classes, current understanding of the molecular and neurobiological basis of pheromone perception and signal processing, and the associations between chemical cues and colony-level social behavior dynamics. Furthermore, we evaluate progress in pheromone-based management approaches, including pheromone-enhanced baits and trail disruption techniques, highlighting both their potential to improve the specificity and efficacy of fire ant management and the current practical limitations for large-scale field applications. Finally, current significant knowledge gaps and challenges are discussed, particularly the partial characterization of pheromone identity, the ambiguous and biological significance of chemical cues, and challenges in applying laboratory research in pest management under field conditions. By linking chemical ecology, neurobiology, and invasion biology to pest management, this review outlines priority directions for future research and provides a theoretical foundation for developing more sustainable, targeted pest control approaches for fire ant management. Full article

Particulate Matter (PM) is a type of air pollution that poses risks to human health, the environment, and property. Among the various PM types, PM₁₀ is particularly significant, as it acts as a vector for numerous hazardous trace elements that can negatively impact human health and the ecosystem. Identifying potential sources of PM₁₀ and quantifying their impact on ambient concentrations is crucial for developing efficient control strategies to meet threshold values. Receptor modeling, which identifies sources using chemical species information derived from PM samples, has been widely used for source apportionment. In this study, PM₁₀ samples were collected over three periods (April, May, and June 2021), each lasting 16 days, using semi-automatic dust sampling systems at two sites in Biga, Canakkale, Turkiye. The relative contributions of different source types were quantified using EPA PMF (Positive Matrix Factorization) based on 35 elements comprising PM₁₀. As a result of the analysis, five source types were identified: crustal elements/limestone/calcite quarry (64.9%), coal-fired power plants (11.2%), metal industry (9%), sea salt and ship emissions (8.5%), and road traffic emissions and road dust (6.3%). The distribution of source contributions aligned with the locations of identified sources in the region. Full article

To improve the fire safety performance of fire protection renovation projects for existing public buildings, this paper systematically sorts out and analyzes relevant research studies, accident reports, and fire protection renovation codes and guidelines. It constructs a fire performance evaluation system for such projects, including 4 first-level indicators—”Building Characteristics”, “Building Fire Protection and Rescue”, “Fire Facilities and Equipment”, and “Heating, Ventilation, Air Conditioning (HVAC) and Electrical Systems”—and 19 second-level indicators such as “Building Usage Function”. The subjective–objective combined weighting method of Analytic Hierarchy Process (AHP)-CRITIC is adopted to determine the weights of indicators at all levels. Four high-weight second-level indicators are selected as core remediation objects: average fire load density, floor layout, automatic fire alarm and linkage control system, and electrical systems. Meanwhile, the evaluation system is converted into a Bayesian Network model, with an empirical verification analysis carried out on a shopping mall in Chaoyang District, Beijing, as a case study. Results show that the approach of combining partial codes with the rectification of high-weight indicators can reduce the fire occurrence probability of the mall from 78%, before renovation, to 24%. Therefore, the constructed evaluation system and Bayesian Network model can realize the accurate quantification of fire risks, provide scientific and feasible technical schemes for the fire protection renovation of existing public buildings, and lay a foundation for enriching and improving fire protection assessment theories. Full article

The issue of overpressure at fire doors in escape passage is often overlooked in traditional tunnel design. Current design approaches tend to overemphasize maintaining positive pressure inside the passage for smoke prevention, which results in excessive resistance when opening fire doors. This can hinder emergency evacuation efficiency and pose a threat to personnel safety. This study focused on a typical 1000-m-long straight escape passage to investigate the overpressure problem of fire doors in highway tunnels from both theoretical and empirical perspectives. Traditional pressure calculations for tunnel escape passages adopt relevant guiding designs from the building category, which may lead to certain errors. Therefore, on this basis, this paper employs pressure calculation equations based on the specific pipeline characteristics of smoke control systems. By solving the pressure calculation equations for the fire doors in escape passages, the thrust required to open the doors in the closed state was analyzed. Results show that the force needed to open a fire door can reach up to 168 N under fire conditions, which far exceeds the allowable limits stipulated in relevant design standards. Furthermore, the results indicate that the maximum allowable length of the escape passage should not exceed 3200 m within acceptable pressure limits through numerical simulation. A mathematical relationship between passage length and fire door pressure was also established, confirming the accuracy of the maximum allowable passage length. This study analyzed the hazards of overpressure in escape passages and proposes a method for determining the maximum permissible passage length, aiming to balance the requirements of smoke control with the safety of personnel evacuation. Full article

During the diesel engine start-up phase, low rotational speed and coolant temperature result in poor fuel atomization and prolonged ignition delay. This impedes the in-cylinder combustion process and directly impacts the engine’s emission performance. As the first combustion cycle during the starting process, the initial starting cycle significantly influences subsequent combustion cycles and overall starting performance. This paper proposes a target-torque-based control strategy for fuel injection quantity during the starting process. It optimally determines the target acceleration curve for the starting process, thereby calculating the optimal fuel injection quantity for the initial starting cycle. Based on this, a combustion system simulation model of the diesel engine was established using the 3D CFD software AVL FIRE v2010. The simulation investigated the impact of first injection speed on the combustion process and performance of the first firing cycle under different ambient temperatures: normal temperature (20 °C), low temperature (5 °C), and cold start (−10 °C). The results indicate that the optimal first cycle injection quantities under normal, low, and cold start conditions are 17.3 mg, 18.5 mg, and 20.4 mg, respectively. The impact of first injection speed on the first firing cycle combustion process primarily manifests in the mixture formation rate and time, and higher speeds do not necessarily yield better results. The optimal first injection speeds at normal temperature (20 °C), low temperature (5 °C), and cold start (−10 °C) were 220 r/min, 240 r/min, and 220 r/min, respectively. Corresponding indicated thermal efficiencies were 30.74%, 28.67%, and 28.7%, with relatively low emissions of pollutants such as CO, NOx, and HC. 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

Cropland fires are an important source of air pollution emissions and have a significant impact on regional air quality and human health. Although straw-burning ban policies have been implemented to mitigate emissions, the dynamics of PM_2.5 emissions from cropland fires under such stringent regulations are still not fully understood. This study utilizes PM_2.5 emission data from the Global Fire Assimilation System (GFAS), land-cover data from CLCD, and PM_2.5 concentration data from ChinaHighAirPollutants (CHAP) to examine the dynamic evolution of PM_2.5 emissions from cropland fires under straw-burning ban policies across China and to assess their environmental impacts. The results show that the 2013 Air Pollution Prevention and Control Action Plan initiated the development of provincial straw-burning ban policies. These policies resulted in a drastic reduction in PM_2.5 emissions from cropland fires in North China (NC), with a 65% decrease in 2022 compared to the 2012 peak. In contrast, a notable lagged effect was observed in Northeast China (NEC), where the increasing trend of PM_2.5 emissions was not reversed until 2017. By 2022, emissions in this region had declined by 53% and 45% compared to the 2015 peak and 2017 sub-peak, respectively. Moreover, significant regional differences were found in the environmental impacts of PM_2.5 emissions from cropland fires, with strong effects during summer in NC and during spring and autumn in NEC. This study provides empirical support for understanding the environmental impacts of cropland fires in key regions of China and offers critical insights to inform and refine related pollution control policies. 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

Northern Thailand experiences recurrent seasonal haze driven by biomass burning (BB), which results in hazardous PM2.5 exposure and elevated environmental health risks. To address the need for timely and spatially resolved emission information, this study developed and evaluated an operational near-real-time (NRT) biomass-burning PM2.5 emission estimation system using the Fire INventory from NCAR version 2.5 (FINNv2.5). The objectives of this study are threefold: (1) to construct a high-resolution (≤1 km) NRT biomass-burning PM2.5 emission inventory for Northern Thailand; (2) to assess its temporal and spatial consistency with ground-based PM2.5 measurements and satellite fire observations; and (3) to examine its potential utility for informing environmental health risk management. The developed system captured short-lived, high-intensity burning episodes that defined the haze crisis, revealing a distinct peak period from late February to early April. Cumulative emissions from January to April 2024 exceeded 250,000 tons, dominated by Chiang Mai (25.8%) and Mae Hong Son (25.5%), which together contributed 51.3% of regional emissions. Strong correspondence with MODIS/VIIRS FRP (r = 0.79) confirmed the reliability of the NRT emission signal, while regression against observed PM2.5 concentrations indicated a substantial background burden (intercept = 40.41 μg m⁻³) and moderate explanatory power (R² = 0.448), reflecting additional meteorological and transboundary influences. Translating these relationships into operational metrics, an Emission Control Threshold of 1518 tons day⁻¹ was derived to guide targeted burn permitting and reduce population exposure during peak-risk periods. This NRT biomass-burning PM2.5 emission estimation framework offers timely emissions information that may support decision makers in environmental health risk management, including the development of early warnings, adaptive burn-permit strategies, and more coordinated responses across Northern Thailand. Full article

A portable and integrated monitoring device was developed to digitally assess both water levels and surrounding fire-related conditions in forest firefighting water buckets using multi-sensor fusion. The system integrates a hydrostatic liquid-level sensor with temperature–humidity and smoke sensors. Validation was performed through field-oriented experiments conducted under semi-controlled conditions. Water-level measurements were collected over a three-month period under simulated forest conditions and benchmarked against conventional steel-ruler readings. Early-stage fire monitoring experiments were carried out using dry wood and leaf litter under varying wind speeds, wind directions, and representative extreme weather conditions. The device achieved a mean water-level bias of −0.60%, a root-mean-square error of 0.64%, and an overall accuracy of 99.36%. Fire monitoring reached a maximum detection distance of 7.30 m under calm conditions and extended to 16.50 m under strong downwind conditions, with performance decreasing toward crosswind directions. Stable operation was observed during periods of strong winds associated with typhoon events, as well as prolonged high-temperature exposure. The primary novelty of this work lies in the conceptualization of a Collaborative Forest Resource–Hazard Monitoring Architecture. Unlike traditional isolated sensors, our proposed framework utilizes a dual-domain decision-making model that simultaneously assesses water-bucket storage stability and micro-scale fire threats. By implementing a robust ‘sensing–logic–alert’ framework tailored for rugged environments, this study offers a new methodological reference for the intelligent management of forest firefighting resources. Full article

To achieve more precise and regionally adaptive emission control, this study develops a dual-control framework that simultaneously constrains both total carbon emissions and pollutant concentration levels. Regional environmental heterogeneity is incorporated into the dispatch of generating units to balance emission reduction and operational efficiency. Based on this concept, a regional carbon emission allowance allocation model is constructed by integrating ecological pollutant concentration thresholds. A multi-source Gaussian plume dispersion model is further developed to characterize the spatial and temporal distribution of pollutants from coal-fired power units. These pollutant concentration constraints are embedded into an environmental–economic dispatch model of a coupled electricity–hydrogen–carbon system supported by hybrid storage. By optimizing resource use and minimizing environmental damage at the energy-supply stage, the proposed model provides a low-carbon foundation for the entire industrial production cycle. This approach aligns with the sustainable development paradigm by integrating precision environmental management with circular economy principles. Simulation results reveal that incorporating pollutant concentration control can effectively reduce localized environmental pressure while maintaining overall system economy, highlighting the importance of region-specific environmental capacity in enhancing the overall environmental friendliness of the industrial chain. Full article