Search Results (391)

Wildfire risks are increasing due to climate change, which poses a challenge to conventional firefighting strategies. In the wildland–urban interface (WUI), people and their infrastructure are increasingly vulnerable to fire. Strategic planting of low-flammable vegetation as green firebreaks has emerged to support wildfire management in the WUI. However, under extreme heat and drought, even low-flammability plants become fuel, contributing to fire spread and intensity. This paper presents a conceptual design framework for irrigated green firebreaks (iGFBs), which does not seek fine detail, or transferability, but rather it provides the initial concept for integrating vegetation design with supplemental irrigation to maintain fuel moisture and enhance fire-regulating ecosystem services. The framework is structured around landscape contexts, priority ecosystem services, integrated design solutions, and implementation considerations. A case study in Noosa Shire, Queensland, Australia, demonstrates how urban water reuse, including greywater and rainwater, can provide the needed irrigation in a WUI landscape. The iGFB concept highlights the potential to reduce fire intensity and slow fire spread while delivering co-benefits such as localised cooling and enhanced biodiversity. While the framework is site-responsive, its underlying principles are transferable to other WUI settings. Further research is required to evaluate the effectiveness of iGFBs under different fire and climate scenarios. Full article

To address the resource utilization of waste tires and the fire-safety concerns in engineering applications of rubber concrete (RC), this study systematically investigates the residual static and dynamic mechanical properties of RC after exposure to elevated temperatures and subsequent cooling to room temperature. Specimens are prepared by replacing fine aggregate with rubber particles at equal volume replacement ratios of 0%, 5%, 15%, and 30%. After undergoing gradient heating to target temperatures ranging from 20 °C to 300 °C, the specimens are naturally cooled to room temperature prior to testing. Subsequently, static compressive and splitting tensile tests, along with dynamic impact tests using a Split Hopkinson Pressure Bar (SHPB), are performed. These experiments are supplemented by scanning electron microscopy (SEM) to elucidate the microscale mechanisms. The results show that the residual static strength decreases monotonically with increasing rubber content and temperature. For the 30% rubber content mixture, the compressive strength decreased by approximately 40.6% from ambient temperature to 300 °C, and its strength is 64.6% lower than that of NC at 300 °C. Dynamic strength exhibits a pronounced strain-rate effect, with the strain-rate sensitivity of DIF being enhanced by higher rubber content. Energy dissipation increases substantially with strain rate; rubberized mixtures generally exhibit higher energy dissipation than NC at lower strain rates, though this effect becomes less evident at higher strain rates. These findings provide a theoretical foundation for the application of RC in complex thermo-mechanical loading scenarios, particularly in evaluating its post-fire residual load-bearing capacity. Full article

Mitigating structural failure and improving the fire safety of concrete infrastructure during severe thermal events depends critically on the high-temperature resilience of Portland cement paste. Given the increasing production of Portland blended cements, understanding their high-temperature behavior is crucial for ensuring the safety of building structures. This study investigates the effects of exposure to high temperatures (up to 1200 °C) on Portland cement pastes containing ground granulated blast furnace slag and quartz powder, focusing on their thermal stability and the chemical reactions occurring under these conditions. In situ X-ray diffraction (XRD) with a heating module was employed to observe real-time phase transformations as the temperature increased, supported by ex situ scanning electron microscopic analysis. The results showed changes in the mineralogical composition, with particular attention to the decomposition of calcium hydroxide and the formation of melilite above 900 °C. These transformations suggest thermal reactions between cement hydrate products (calcium silicates and aluminates) in the presence of slag and quartz powder. Mixtures containing quartz powder exhibited increased porosity and phase transformation shifts at lower temperatures, reflecting the combined effects of quartz addition, reduced reactive binder content, and an increased effective water-to-binder ratio. Notably, lower strength-grade cements containing fly ash (additional alumina source) show higher degrees of formation of calcium–aluminate silicate phases such as melilite upon heating. Compared to conventional studies, the novelty of this study lies in the use of an in situ experimental setup, which uniquely identifies the temperature thresholds of chemical changes and the formation of new phases such as melilite in cement–selected slag mixes, while also capturing their recrystallization upon cooling. Full article

Subway tunnels exacerbate fire hazards, revealing a critical lacuna regarding the spatio-temporal coupling of fire progression and human egress. To address this, this study proposes and validates an Integrated Spatio-Temporal Risk Assessment Model to explicitly quantify survivability thresholds under complex fire dynamics. The framework synergizes Large-Eddy Simulation (LES) based Computational Fluid Dynamics with agent-based pedestrian trajectory modeling within a 3D tunnel featuring a 2% longitudinal gradient. Evaluating 9.5 MW and 12 MW fire energies, the model assessed Single-Sided Evacuation (SSE), Double-Sided Evacuation (DSE), and Sprinkler-Assisted Single-Sided Evacuation (SSE-S) across 2160 agents. Hazards were quantified by continuously resolving Fractional Effective Dose (FED) indices, 60 °C boundaries, and 500 ppm CO fronts. Simulations reveal the gradient induces a severe stack effect, accelerating toxic dispersion and yielding temperatures exceeding 1200 °C. Consequently, SSE engendered fatal bottlenecks (FED: 15.33), whereas DSE optimized pedestrian flux, capping peak FED at 0.52. Crucially, while active suppression (SSE-S) extinguished flames within 105 s, thermodynamic cooling induced a paradoxical loss of smoke buoyancy, causing toxic layers to stratify at the breathing zone. Ultimately, while DSE and SSE-S are paramount for survivability, water-based suppression generates localized toxicological risks, necessitating the integration of low-level smoke detection and extraction architectures in future subterranean designs. Full article

To address the challenge of balancing flame retardancy and dust suppression in conventional coal mine treatment materials, a multi-component synergistic flame-retardant dust-suppressant gel was fabricated using carboxymethyl cellulose (CMC) as the matrix, compounded with ammonium polyphosphate (APP), zinc borate (ZB), and polycarbodiimide (PCDI) as a cross-linking agent. The optimal formulation was determined via orthogonal experimental design combined with performance characterization, yielding a composition of 1 wt% CMC, 8 wt% APP, 2 wt% ZB, and 0.5 wt% PCDI. Systematic evaluations—including wettability tests, thermogravimetric analysis, and fire-extinguishing trials—demonstrated that the resultant CMC-based composite gel exhibits excellent structural stability and environmental tolerance. Specifically, the contact angle on the coal surface decreased sharply from 72.8° to 17.2°, and the mass loss rate after 30 min of wind erosion was merely 4.16%. Treatment with the gel elevated the critical temperature of the coal–oxygen reaction from 70 °C to 80 °C and reduced CO emissions by 40% at 170 °C. Furthermore, the temperatures corresponding to the maximum weight loss rate, ignition, and burnout increased by 12.9 °C, 16.8 °C, and 28.9 °C, respectively. Fire suppression tests revealed that the gel rapidly cools high-temperature coal seams and effectively prevents reignition. Mechanistic investigations indicate that the CMC-PCDI cross-linked network synergizes with the APP-ZB phosphorus–boron flame-retardant system: the three-dimensional gel architecture provides physical encapsulation and water retention, while the intumescent char layer formed by APP-ZB offers efficient oxygen barrier protection. This study provides a reliable gel-based technical solution for the integrated prevention and control of coal dust pollution and spontaneous combustion disasters in underground mines. Full article

This study introduces a novel class of architected foam structures based on triply periodic minimal surface (TPMS) geometries for passive battery thermal management. Unlike conventional cold plates that rely on active pumping or high-conductivity solid materials, the proposed TPMS-like foams leverage convective fluid transport within a lightweight, electrically insulating polymer matrix. We present the design, fabrication, and experimental characterization of Schwarz Primitive TPMS structures manufactured via injection molding using silicone rubber, which has a comparable quality to additively manufactured polymer cold plates but with significantly lower manufacturing complexity and cost. The TPMS cold plates achieve passive fluid circulation without external pumps, reducing parasitic power consumption while maintaining thermal resistance values of approximately 23.5 K/W. Although its thermal resistance is higher than that of an aluminum plate of the same size (2.7 K/W), the TPMS cold plate is electrically insulating and offers additional safety benefits. Additionally, it can be fabricated from and filled with fire-retardant materials to prevent thermal propagation while maintaining a relatively low temperature gradient. Mechanical compression testing of TPMS foam samples with about 30% solid volume fraction showed a compressive strength of 86.2 kPa at 0.2 strain, equivalent to 30.5% of the compressive modulus of solid silicone (282.6 kPa). Compared to solid silicone plates (thermal resistance is 1420 K/W), the TPMS fluid-filled structures reduce thermal resistance by more than two orders of magnitude. This work establishes design rules, fabrication protocols, and performance benchmarks for TPMS-based passive cooling devices, offering a scalable pathway toward safer, lighter, and more energy-dense battery packs. Full article

Effective thermal management is a cornerstone of safe, long-life lithium-ion battery operation, especially under high-rate charge–discharge and dynamic driving conditions. Conventional active cooling technologies face inherent trade-offs between heat dissipation efficiency, system complexity, and temperature uniformity, while phase change materials (PCMs) provide a promising passive alternative by absorbing latent heat during phase transition to buffer temperature spikes, improve temperature uniformity, and delay thermal runaway propagation. This paper presents a comprehensive review of recent advances in PCM-based lithium-ion battery thermal management, systematically covering the full scope from fundamental battery heat generation mechanisms to material synthesis optimization and hybrid system integration. At the material level, we analyze state-of-the-art strategies to address the intrinsic drawbacks of organic PCMs—low thermal conductivity, mismatched phase transition temperatures, and high flammability—including the construction of carbon/metal conductive skeletons, compositional tuning of phase change behavior, and flame-retardant modifications. These approaches have yielded composite PCMs with significantly improved heat transport capability and fire safety, while preserving high latent heat storage capacity. At the system level, we evaluate the thermal performance of pure passive PCM configurations, which excel at peak temperature suppression and inter-cell temperature uniformity, as well as hybrid designs that combine PCMs with air or liquid cooling to resolve heat accumulation issues and maintain stable performance under prolonged, demanding operating cycles. Despite these advances, key challenges remain: balancing high thermal conductivity with high latent heat capacity, developing climate-adaptable phase transition temperatures, and integrating multiple functionalities without compromising core thermal storage properties. Looking forward, future research directions include multifunctional integrated composites, smart adaptive PCMs, cost-effective scalable manufacturing, and precision structural engineering. This review also summarizes quantified performance trade-offs and provides actionable design guidelines for both material development and system-level integration. Full article

The Smart Readiness Indicator (SRI) provides a European framework for assessing the capacity of buildings to optimise operation, respond to occupants and interact with energy grids. Its current catalogue covers nine domains: heating, cooling, domestic hot water, ventilation, lighting, dynamic envelope, electricity, electric vehicle charging, and monitoring and control. This Perspective argues that this boundary is too narrow for complex buildings, where services such as lifts, security, fire safety, swimming pools, irrigation, outdoor lighting, kitchens, laundries, refrigeration, laboratories, and information and communication technology (ICT) rooms may significantly affect energy use, water use, safety, resilience, maintenance and user experience. The paper proposes five additional service families for SRI 2.0: mobility and accessibility; safety and security; water and outdoor environmental services; outdoor and site infrastructure; and special energy-intensive and facility services. These should be introduced as optional, building-type-specific modules assessed through familiar SRI functionality levels. This would make the SRI more realistic, actionable and relevant. Full article

In response to the significant seasonal fluctuations in heating and cooling loads in greenhouses for high-value fruit trees in northern China, as well as issues such as heat accumulation on the ground-source side and high carbon emissions from coal-fired heating, this paper proposes a coupled energy supply system comprising a PVT system, a mine pit seasonal thermal storage unit, a ground-source heat pump and a cooling tower. Taking a 30,000 m² cherry greenhouse and an existing 15,000 m³ mine pit thermal storage reservoir in Weifang, Shandong Province, as the research objects, annual design-stage simulations with a 0.125 h time step were conducted using SketchUp-TRNBuild and TRNSYS. Discrete sensitivity analyses and engineering constraints were used to determine the PVT area and cooling tower outlet temperature. Heating demand mainly occurred from November to February, whereas cooling demand was concentrated from June to September. The selected 2452 m² PVT system supplied direct heating for 34 days, covered 23.05% of the seasonal heating demand, and achieved a storage efficiency of 69.17%. Without a cooling tower, the first-year soil temperature increased by 1.1 °C. With a 26 °C cooling tower outlet temperature, the soil thermal imbalance ratio decreased to 2.4%, and the 15-year soil temperature rise was limited to 0.28 °C. The recommended system required 1.3239 million kWh of net purchased electricity annually, reduced operating costs by approximately CNY 802,800 (USD 118,243) and operational emissions by 2027.8 tCO₂-eq per year relative to the baseline, and had a static payback period of 6.4 years. The annual operational emission reduction was linearly extrapolated over a 20-year assessment period under fixed weather, load, equipment performance, and grid emission assumptions, resulting in a scenario-based carbon reduction threshold of 40,556 tCO₂-eq. Net life cycle carbon savings would be possible if the additional emissions from construction, equipment replacement, and end-of-life treatment remained below this threshold. Full article

Water-mist curtains act as thermal barriers to longitudinal smoke propagation in confined-space fires, but their downstream cooling remains difficult to predict with reduced-order models. This study develops a calibrated semi-analytical model that uses the incident temperature at the curtain’s upstream face and combines a one-dimensional droplet residence-time solution with a Stefan-flow heat-transfer reduction. A lumped closure coefficient, k = Aeq/A0, collectively accounts for the simplified initial velocity and trajectory, spray nonuniformity, ensemble shielding, representative properties, and boundary inputs. The coefficient is inferred from 5 MW FDS cases with D₃₂ = 400–700 μm and is not interpreted as breakup or coalescence, which were absent from the monodisperse simulations. Cases at 2, 4, and 6 MW provide within-domain blind tests, whereas 1, 3, and 7 MW provide supplementary assessment; the maximum reconstructed relative deviation in exit temperature is 13.4%. A 1:5 experiment supplies a cross-scale trend comparison, but its geometry differs from the full-scale FDS domain, and only the 3 MW-equivalent fire has an archived mass-loss calibration. The model is therefore limited to the present calibration domain and should not be transferred directly across geometries, nozzles, or ventilation conditions. Full article

Battery electric vehicle (BEV) fires in road tunnels can intensify thermal, smoke transport, visibility, and CO exposure hazards under confined ventilation. This study evaluated the combined mitigation performance of water mist and semi-transverse mechanical ventilation. A three-dimensional PyroSim/FDS model of a 200 m × 10 m × 5 m tunnel was established with a 7 MW BEV design fire at the midpoint. The prescribed-source model was assessed against a reduced-scale lithium-ion battery tunnel experiment; at the representative monitoring location, the simulated temperature history reproduced the main trend, with deviations of approximately 7% and 10% at the first and second peaks. Thirty-six coupled cases examined ventilation mode, nominal opening velocity, nozzle arrangement and spacing, flow rate input, droplet diameter, and spray cone angle. Supply ventilation improved hot-smoke-layer cooling and visibility, whereas exhaust ventilation more effectively reduced the local CO volume fraction. Under the baseline weighting scheme, the highest-ranked case reduced the peak local ceiling-region and near-fire gas temperatures by 77.8% and 82.2%, increased average visibility during 200–500 s by 42.9%, and achieved a comprehensive relative mitigation index (CRMI) of 56.6%. Two supplementary nominal 10 MW simulations showed that this case retained substantial thermal control, reducing the two peak temperatures by 65.7% and 74.1%, but did not improve local visibility or CO. Thus, the thermal-mitigation trend persisted at the higher nominal input, whereas the full multi-hazard ranking was not transferable across fire sizes. Full article

The coal gangue waste dumps formed by open-pit coal mining are prone to low-temperature oxidation and heat storage, creating deep hidden high-temperature abnormal areas, continuously releasing toxic gases, and causing complex disasters such as slope instability and water and soil pollution. At present, self-ignition prevention and control technology is only applicable to the shallow treatment of small and flat gangue mountains. For large, deep, high-temperature waste dumps with significant height differences, multiple steps, and large areas, there is a lack of an integrated, complete set of technologies. The multi-field coupling mechanism of grouting fire extinguishing lacks engineering verification, and there is no quantitative evaluation system combining long and short periods. This paper takes the deep spontaneous-combustion high-temperature area of the No. 5 spoil dump of Lutian Coal Mine of Wuhai Energy as the research object. With the core goals of precisely delineating the fire zone space, revealing the multi-field coupling fire extinguishing mechanism of grouting, and establishing a long-term quantitative evaluation system, this study proposes a multi-process joint governance technology, along with a standardized hole filling and zoned differentiated grouting parameter system. The research systematically demonstrated technical feasibility through on-site drilling, large-scale grouting construction, and full-process quality control and error analysis. The results show that the 50 m interval geothermal gradient boreholes can accurately identify high-temperature distributions in the deep part of the dump from 0 to 34 m. The maximum combustion depth of the fourth-level and fifth-level platforms is 34 m and 20 m, respectively. A total of 1578 grouting boreholes have been constructed, with a total grouting volume of 139,289.3 cubic meters. After the treatment, the concentrations of toxic gases were all below the detection limits of the equipment, and the single cooling range reached 43% to 87%. This research refined relevant theories on the spontaneous combustion control of large-scale multi-step waste dumps, established standardized engineering processes, and provided theoretical and engineering references for the prevention and control of spontaneous combustion of solid waste in similar mines. It holds significant value for the ecological safety of mines and regional pollution control. Full article

Lithium-ion battery fires are governed by continuous heat release during thermal runaway, flammable gas venting, and thermal coupling between adjacent cells. Even after visible flames are extinguished, post-extinguishment temperature rise, thermal runaway propagation, and reignition may still occur. This review establishes a full-process control framework linking flame suppression, sustained cooling, thermal runaway propagation mitigation, and reignition control. Within this framework, water-based agents, clean gaseous agents, dry powder agents, foams, cryogenic media, and hybrid suppression methods are not only compared by their flame extinguishment performance but also by their cooling capability, thermal runaway propagation/reignition control, scenario applicability, and environmental impacts. Evaluation metrics and standardization requirements are further integrated to support cross-study comparison and practical suppressant selection. Existing studies indicate that a single suppressant is generally unable to achieve both rapid flame extinguishment and post-extinguishment thermal stability. Multi-mechanism synergy, realistic scenario validation, and standardized evaluation protocols are therefore essential for improving the full-process control of lithium-ion battery fires. Full article

Western Siberia is one of the largest high-latitude lowland peatland regions on Earth and stores vast amounts of organic carbon in landscapes where vegetation, hydrology and fire are strongly regulated by permafrost. However, the long-term interactions among fire disturbance, permafrost dynamics, peatland development and forest–mire vegetation change remain insufficiently resolved. Here, we reconstructed regional vegetation dynamics, local mire succession, permafrost evolution and fire activity in the subarctic Pur–Taz interfluve, Western Siberia, during the Early to Middle Holocene from 11.2 to 4.4 cal kyr BP. The study combines pollen, non-pollen palynomorphs, microcharcoal records, principal component analysis and comparison with modern surface-sample analogues. The record documents a transition from Early Holocene larch–birch forest-tundra with no close modern analogue to increasingly heterogeneous forest–mire and shrub-tundra landscapes. After 9.5 cal kyr BP, Betula pubescens declined and Picea obovata pollen increased, with the strongest spruce signal between ca. 5.5 and 4.7 cal kyr BP. However, this pattern did not necessarily reflect a uniform regional expansion of spruce. Integrated fire reconstruction, based on microcharcoal peaks, Gelasinospora-type and declines in Betula pubescens-type pollen, indicates that recurrent fires after 8.0 cal kyr BP preferentially affected well-drained birch–larch uplands, whereas wetter riparian habitats acted as refugia for spruce. This landscape contrast increased the relative contribution of Picea pollen from fire-protected valleys, producing an apparent, partly artefactual spruce expansion signal. Locally, an open lake present at 11.2 cal kyr BP was transformed into a peatland after ca. 9.7 cal kyr BP. Cooling associated with the 8.2 cal kyr BP event promoted permafrost aggradation and polygonal mire initiation, whereas subsequent thaw and subsidence favoured waterlogging and mesotrophic fen development. Repeated alternation between permafrost aggradation, oligotrophication, degradation and renewed waterlogging culminated in polygonal microrelief by 6.1–5.3 cal kyr BP. These results show that Holocene vegetation change in the Pur–Taz interfluve was not controlled by climate alone, but by spatially heterogeneous feedbacks among permafrost state, peatland hydrology, fire disturbance and pollen-source structure. The West Siberian record provides a palaeoecological analogue for anticipating nonlinear vegetation and fire-regime responses in permafrost lowlands under ongoing Arctic warming. Full article

This study presents a screening-level conceptual, stoichiometric, and scenario assessment of a pathway linking sulfur dioxide (SO₂) capture from coal-fired flue gas to sulfuric acid production and the downstream reaction of sulfuric acid with pretreated scrap aluminum. A regenerable sodium sulfite (Wellman–Lord) capture route, followed by gas polishing and drying, catalytic SO₂ oxidation, controlled SO₃ absorption, acid conditioning, and an Al–H₂SO₄ reactor, is used as the reference configuration. The sulfur balance distinguishes sulfur in coal, ash retention, gaseous SO_x, SO₃/acid mist, absorber inlet and stack slip, captured sulfur, regenerated sulfur, and sulfate purge. Under the central assumptions, 1 t of sulfur in coal yields 0.849 t of recovered sulfur equivalent, 2.599 t of H₂SO₄, 0.477 t of aluminum feed, 2.419 t of anhydrous-equivalent Al₂(SO₄)₃, 4.240 t of commercial aluminum sulfate on a 17 wt% Al₂O₃ basis, and 42.4 kg of H₂ at 80% aluminum conversion. The upstream base-energy screen is 3.3–7.2 GJth and 0.18–0.45 MWhe per tonne of sulfur in coal. Diluting the acid to the selected 0.5–1.0 M aluminum-reaction window and subsequently producing a 17 wt% Al₂O₃ product creates a minimum water-removal load of 21.6–47.6 t and a latent-heat floor of approximately 49–108 GJth/t S. Retail prices are replaced by 2024 customs unit values, and internal-acid-production and sulfuric-acid-opportunity-cost boundaries are evaluated separately. In the central opportunity-cost case, the H₂ value must reach approximately 6.9 USD/kg merely to balance material values before CAPEX, OPEX, energy, purification, transport, and environmental-compliance costs. The Afşin–Elbistan A case is treated as a full-design-throughput illustration based on an historical 18 Mt/y coal requirement, not as a measured current operating average; coal sulfur is tested over 1.0–2.5 wt%. The aluminum step is restricted to cooled and diluted 0.5–1.0 M H₂SO₄ at 40–60 °C, and direct H₂ production from 96 to 98 wt% acid is not assumed. Plant-specific capacity factor, time-matched coal assays, flue-gas flow, oxygen-corrected stack data, reaction kinetics, gas purity, and product quality remain to be verified. The integrated sustainability screening indicates conditional circular-economy potential rather than a demonstrated sustainability advantage: sulfur recovery must be weighed against energy and water demand, sulfate purge and wastewater, diversion of recyclable aluminum from remelting, hydrogen purification, and market-scale product offtake. The pathway therefore remains a research hypothesis requiring experimental validation, process simulation, techno-economic assessment, comparative life-cycle assessment, safety analysis, and market verification. Full article