Fire

14 pages, 9532 KiB

Open AccessArticle

Analysis of Fire Resistance Performance of Double Swing Fire Doors Using Thermo-Mechanical Model Depending on Gap Size

by Bohyuk Lim, Bongki Bae, Mingyu Jang, Heedu Lee, Changjun Lee, Minkoo Kim and Changyong Yi

Fire 2025, 8(6), 238; https://doi.org/10.3390/fire8060238 - 19 Jun 2025

Abstract

Fire doors are installed between compartments to prevent the spread of fire. During a fire, the temperature difference between the exposed and unexposed surfaces induces bending deformation of the door, thereby reducing its fire resistance performance. Excessive deformation may further compromise the structural [...] Read more.

Fire doors are installed between compartments to prevent the spread of fire. During a fire, the temperature difference between the exposed and unexposed surfaces induces bending deformation of the door, thereby reducing its fire resistance performance. Excessive deformation may further compromise the structural integrity of the door. This study presents a thermo-mechanical model that idealizes the bending behavior of double swing fire doors based on the deflection equation of a simply supported beam subjected to a thermal gradient between the tensile and compressive sides. A criterion of deformation, quantifying the relationship between the meeting stile gap and the resulting maximum deflection, is introduced and compared with the predicted values. The validity of the proposed model was confirmed through fire resistance tests conducted on both insulated and non-insulated fire door specimens, demonstrating strong agreement with experimental results. Furthermore, by comparing the predicted deformation with the deformation criterion, the impact of increasing gap sizes on the service life of fire doors on their fire resistance performance was evaluated. Based on this analysis, appropriate gap size limits for different door specifications are proposed to ensure reliable fire performance. Full article

(This article belongs to the Special Issue Current Advances in the Assessment and Mitigation of Fire Risk in Buildings and Urban Areas: 2nd Edition)

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19 pages, 3138 KiB

Open AccessArticle

FireCLIP: Enhancing Forest Fire Detection with Multimodal Prompt Tuning and Vision-Language Understanding

by Shanjunxia Wu, Yuming Qiao, Sen He, Jiahao Zhou, Zhi Wang, Xin Li and Fei Wang

Fire 2025, 8(6), 237; https://doi.org/10.3390/fire8060237 - 19 Jun 2025

Abstract

Forest fires are a global environmental threat to human life and ecosystems. This study compiles smoke alarm images from five high-definition surveillance cameras in Foshan City, Guangdong, China, collected over one year, to create a smoke-based early warning dataset. The dataset presents two [...] Read more.

Forest fires are a global environmental threat to human life and ecosystems. This study compiles smoke alarm images from five high-definition surveillance cameras in Foshan City, Guangdong, China, collected over one year, to create a smoke-based early warning dataset. The dataset presents two key challenges: (1) high false positive rates caused by pseudo-smoke interference, including non-fire conditions like cooking smoke and industrial emissions, and (2) significant regional data imbalances, influenced by varying human activity intensities and terrain features, which impair the generalizability of traditional pre-train–fine-tune strategies. To address these challenges, we explore the use of visual language models to differentiate between true alarms and false alarms. Additionally, our method incorporates a prompt tuning strategy which helps to improve performance by at least 12.45% in zero-shot learning tasks and also enhances performance in few-shot learning tasks, demonstrating enhanced regional generalization compared to baselines. Full article

(This article belongs to the Special Issue Intelligent Forest Fire Prediction and Detection)

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19 pages, 11717 KiB

Open AccessArticle

Effects of Rectangular Obstacles on the Flow Characteristics of Ultrafine Dry Powder Fire Extinguishing Agent in Confined Spaces

by Quanwei Li, Qingshan Liu, Cheng Lu, Lulin Tang, Dan Wu and Xin Huang

Fire 2025, 8(6), 236; https://doi.org/10.3390/fire8060236 - 18 Jun 2025

Abstract

This study establishes a transient numerical model for the gas–solid two-phase flow of ultrafine dry powder fire extinguishing agents released in the confined space based on the Fluent software platform. The model investigates the spatial flow and diffusion characteristics of ultrafine dry powder [...] Read more.

This study establishes a transient numerical model for the gas–solid two-phase flow of ultrafine dry powder fire extinguishing agents released in the confined space based on the Fluent software platform. The model investigates the spatial flow and diffusion characteristics of ultrafine dry powder under different obstacle volumes and relative positions. The results show that when an obstacle is present, two recirculation zones are formed by the upper surface of the obstacle, and a low-concentration unfavorable region is created around the obstacle. The concentration difference in ultrafine dry powder between the upper and lower recirculation zones increases monotonically with the obstacle volume. When the obstacle volume increases from 8 dm³ to 15.7 dm³, the concentration difference between the upper and lower zones increases by 5 times at 3.2 s. The time required for the average concentration in both zones to reach the minimum extinguishing concentration, as well as the reduction rate of the normalized characteristic dimension of the adverse region, follows an approximately exponential trend with changes in obstacle volume. The concentration difference between the upper and lower recirculation zones decreases as the distance between the obstacle and the nozzle increases. Compared to the upper position, the concentration difference decreases by 89% and 108% when the obstacle is positioned in the middle and lower parts at 3.2 s, respectively. And the reduction rate of the normalized characteristic dimension increases by 12% and 60% when the obstacle is positioned in the middle and lower parts, respectively. Full article

(This article belongs to the Special Issue Building Fire Prediction and Suppression)

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15 pages, 4123 KiB

Open AccessArticle

Characterizing Risks for Wildfires and Prescribed Fires in the Great Plains

by Zifei Liu, Izuchukwu Oscar Okafor and Mayowa Boluwatife George

Fire 2025, 8(6), 235; https://doi.org/10.3390/fire8060235 - 18 Jun 2025

Abstract

Increasing wildfire activities across the Great Plains has raised concerns about the effectiveness and safety of prescribed fire as a land management tool. This study analyzes wildfire records from 1992 to 2020 to assess spatiotemporal patterns in wildfire risk and evaluate the role [...] Read more.

Increasing wildfire activities across the Great Plains has raised concerns about the effectiveness and safety of prescribed fire as a land management tool. This study analyzes wildfire records from 1992 to 2020 to assess spatiotemporal patterns in wildfire risk and evaluate the role of prescribed fires through the combined analysis of wildfire and prescribed fire data. Results show a threefold increase in both wildfire frequency and area burned, with fire size increasing from east to west and frequency rising from north to south. Wildfire seasons are gradually occurring earlier due to climate change. Negative correlation between prescribed fires in spring and wildfires in summer indicated the effectiveness of prescribed fire in mitigating wildfire risk. Drought severity accounted for 51% of the interannual variability in area burned, while grass curing accounted for 60% of monthly variability of wildfires in grasslands. The ratio of wildfire area burned to total area burned (dominated by prescribed fires) declined from over 20% in early March to below 1% by early April. The results will lay a foundation for the development of a localized fire risk assessment tool that integrates various long-term, mid-term, and short-term risk factors, and support more effective fire management in this region. Full article

(This article belongs to the Special Issue Firefighting Approaches and Extreme Wildfires)

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23 pages, 5175 KiB

Open AccessArticle

Risk Assessment of Sudden Coal and Gas Outbursts Based on 3D Modeling of Coal Seams and Integration of Gas-Dynamic and Tectonic Parameters

by Vassiliy Portnov, Adil Mindubayev, Andrey Golik, Nurlan Suleimenov, Alexandr Zakharov, Rima Madisheva, Konstantin Kolikov and Sveta Imanbaeva

Fire 2025, 8(6), 234; https://doi.org/10.3390/fire8060234 - 17 Jun 2025

Abstract

Sudden coal and gas outbursts pose a significant hazard in deep-seated coal seam extraction, necessitating reliable risk assessment methods. Traditionally, assessments focus on gas-dynamic parameters, but experience shows they must be supplemented with tectonic factors such as fault-related disturbances, weak interlayers, and increased [...] Read more.

Sudden coal and gas outbursts pose a significant hazard in deep-seated coal seam extraction, necessitating reliable risk assessment methods. Traditionally, assessments focus on gas-dynamic parameters, but experience shows they must be supplemented with tectonic factors such as fault-related disturbances, weak interlayers, and increased fracturing. Even minor faults in the Karaganda Basin can weaken the coal massif and trigger outbursts. The integration of 3D modeling enhances risk evaluation by incorporating both dynamic (gas-related) and static (tectonic) parameters. Based on exploratory drilling and geophysical studies, these models map coal seam geometry, fault positioning, and high-risk structural zones. In weakened coal areas, stress distribution changes can lead to avalanche-like gas releases, even under normal gas-dynamic conditions. An expert scoring system was used to convert geological and gas-dynamic data into a comprehensive risk index guiding preventive measures. An analysis of Karaganda Basin incidents (1959–2021) shows all outbursts occurred in geological disturbance zones, with 43% linked to fault proximity, 30% to minor tectonic shifts, and 21% to sudden coal seam changes. Advancing 3D modeling, geomechanical analysis, and microseismic monitoring will improve predictive accuracy, ensuring safer coal mining operations. Full article

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30 pages, 5560 KiB

Open AccessReview

Post-Earthquake Fires (PEFs) in the Built Environment: A Systematic and Thematic Review of Structural Risk, Urban Impact, and Resilience Strategies

by Fatma Kürüm Varolgüneş and Sadık Varolgüneş

Fire 2025, 8(6), 233; https://doi.org/10.3390/fire8060233 - 13 Jun 2025

Abstract

Post-earthquake fires (PEFs) represent a complex, cascading hazard in which seismic damage creates ignition conditions that can overwhelm urban infrastructure and severely compromise structural integrity. Despite growing scholarly attention, the literature on PEFs remains fragmented across disciplines, lacking a consolidated understanding of structural [...] Read more.

Post-earthquake fires (PEFs) represent a complex, cascading hazard in which seismic damage creates ignition conditions that can overwhelm urban infrastructure and severely compromise structural integrity. Despite growing scholarly attention, the literature on PEFs remains fragmented across disciplines, lacking a consolidated understanding of structural vulnerabilities, urban-scale impacts, and response strategies. This study presents a systematic and thematic synthesis of 54 peer-reviewed articles, identified through a PRISMA-guided screening of 151 publications from the Web of Science Core Collection. By combining bibliometric mapping with thematic clustering, the review categorizes research into key methodological domains, including finite element modeling, experimental testing, probabilistic risk analysis, multi-hazard frameworks, urban simulation, and policy approaches. The findings reveal a dominant focus on structural fire resistance, particularly of seismically damaged concrete and steel systems, while highlighting emerging trends in sensor-based fire detection, AI integration, and urban resilience planning. However, critical research gaps persist in multi-hazard modeling, firefighting under partial collapse, behavioral responses, and the integration of spatial, infrastructural, and institutional factors. This study proposes an interdisciplinary research agenda that connects engineering, urban design, and disaster governance to inform adaptive, smart-city-based strategies for mitigating fire risks in seismic zones. This work contributes a comprehensive roadmap for advancing post-earthquake fire resilience in the built environment. Full article

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21 pages, 2506 KiB

Open AccessArticle

Innovative Approaches to the Use of Artillery in Wildfire Suppression

by Daniel Korec, Martin Blaha, Jiří Barta and Jaroslav Varecha

Fire 2025, 8(6), 232; https://doi.org/10.3390/fire8060232 - 12 Jun 2025

Abstract

The increasing frequency and intensity of wildfires in hard-to-reach and hazardous areas represents a significant challenge for traditional firefighting methods. Wildfires pose a growing threat to the environment, property, and human lives. In many cases, conventional suppression techniques prove ineffective, highlighting the need [...] Read more.

The increasing frequency and intensity of wildfires in hard-to-reach and hazardous areas represents a significant challenge for traditional firefighting methods. Wildfires pose a growing threat to the environment, property, and human lives. In many cases, conventional suppression techniques prove ineffective, highlighting the need for innovative and efficient solutions. Recent fires in the Bohemian Switzerland National Park in the Czech Republic; the Los Angeles area in California, USA; and the southeastern region of South Korea have underscored the necessity for alternative wildfire mitigation strategies. This article explores the potential of employing military technologies, such as artillery systems and specialized munitions, in wildfire suppression. The analysis includes a review of previous experiments, the research into non-standard methods, and an assessment of the risks and limitations associated with these approaches. Based on the research and simulations, it was found that one salvo (eight rounds) of fire-suppressant shells can cover up to 650 m² of terrain with suppressant. Finally, this article proposes a direction for further research aimed at integrating military and civilian technologies to enhance the effectiveness of wildfire response. This work contributes to the ongoing discussion on the integration of artillery capabilities into crisis management and provides a foundation for the future research in this field. Full article

(This article belongs to the Section Fire Research at the Science–Policy–Practitioner Interface)

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23 pages, 3341 KiB

Open AccessArticle

Experimental Study on Working Characteristics of Microwave-Assisted Spark Plug Igniter

by Hao Zeng, Changqin Fu, Zhiyu Zhao, Nan Jiang and Zhihao Liu

Fire 2025, 8(6), 231; https://doi.org/10.3390/fire8060231 - 12 Jun 2025

Abstract

In this paper, a study on the working characteristics of microwave-assisted spark plug igniter was carried out. Experiments were carried out in a vacuum chamber to investigate the effects of microwave feeding with different parameters on the spark plug discharge process, breakdown voltage, [...] Read more.

In this paper, a study on the working characteristics of microwave-assisted spark plug igniter was carried out. Experiments were carried out in a vacuum chamber to investigate the effects of microwave feeding with different parameters on the spark plug discharge process, breakdown voltage, average power, discharge spectral intensity, and characteristic temperature of the discharge plasma under different ambient pressures (0.1 MPa at atmospheric pressure and 0.05 MPa at low pressure). The results show that the breakdown voltage decreased by 15.2% and the average power of discharge increased by 49% when the microwave pulse peak power increased from 0 W to 200 W under a low-pressure environment; meanwhile, the breakdown voltage decreased by 10.8% and the average power increased by 23% under an atmospheric-pressure environment. When the microwave pulse frequency was increased from 1 kHz to 10 kHz, the breakdown voltage further decreased by 15.2% in a low-voltage environment, but there was no significant effect on the average power. The plasma characteristic temperature rose significantly with the peak power: the electron temperature rose from 1.961 eV to 2.154 eV with the power at atmospheric pressure, and the vibrational and rotational temperatures also increased significantly. Full article

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20 pages, 7291 KiB

Open AccessArticle

Mapping Delayed Canopy Loss and Durable Fire Refugia for the 2020 Wildfires in Washington State Using Multiple Sensors

by Anika M. Anderson, Meg A. Krawchuk, Flavie Pelletier and Jeffrey A. Cardille

Fire 2025, 8(6), 230; https://doi.org/10.3390/fire8060230 - 11 Jun 2025

Abstract

Fire refugia are unburned and low severity patches within wildfires that contribute heterogeneity that is important to retaining biodiversity and regenerating forest following fire. With increasingly intense and frequent wildfires in the Pacific Northwest, fire refugia are important for re-establishing populations sensitive to [...] Read more.

Fire refugia are unburned and low severity patches within wildfires that contribute heterogeneity that is important to retaining biodiversity and regenerating forest following fire. With increasingly intense and frequent wildfires in the Pacific Northwest, fire refugia are important for re-establishing populations sensitive to fire and maintaining resilience to future disturbances. Mapping fire refugia and delayed canopy loss is useful for understanding patterns in their distribution. The increasing abundance of satellite data and advanced analysis platforms offer the potential to map fire refugia in high detail. This study uses the Bayesian Updating of Land Cover (BULC-D) algorithm to map fire refugia and delayed canopy loss three years after fire. The algorithm compiles Normalized Burn Ratio data from Sentinel-2 and Landsat 8 and 9 and uses Bayes’ Theorem to map land cover changes. Four wildfires that occurred across Washington State in 2020 were mapped. Additionally, to consider the longevity of ‘durable’ fire refugia, the fire perimeters were analyzed to map delayed canopy loss in the years 2021–2023. The results showed that large losses in fire refugia can occur in the 1–3 years after fire due to delayed effects, but with some patches enduring. Full article

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29 pages, 2096 KiB

Open AccessArticle

Dual-GRU Perception Accumulation Model for Linear Beam Smoke Detector

by Zhuofu Wang, Boning Li, Li Wang, Zhen Cao and Xi Zhang

Fire 2025, 8(6), 229; https://doi.org/10.3390/fire8060229 - 11 Jun 2025

Abstract

Due to the complex structure of high-rise space buildings, traditional point fire detectors are not effective in terms of detection range and installation difficulty. Although linear beam smoke detectors are widely adopted, they still face problems such as low accuracy and false alarms [...] Read more.

Due to the complex structure of high-rise space buildings, traditional point fire detectors are not effective in terms of detection range and installation difficulty. Although linear beam smoke detectors are widely adopted, they still face problems such as low accuracy and false alarms caused by interference. To address these limitations, we constructed a 120 m experimental platform for analyzing smoke–light interactions. Through systematic investigation of spectral scattering phenomena, optimal operational wavelengths were identified for beam-type detection. By improving the gated recurrent unit (GRU) neural network, an algorithm combining dual-wavelength information fusion and an attention mechanism was designed. The algorithm integrates dual-wavelength information and introduces the cross-attention mechanism into the GRU network to achieve collaborative modeling of microscale scattering characteristics and macroscale concentration changes of smoke particles. The alarm strategy based on time series accumulation effectively reduces false alarms caused by instantaneous interference. The experiment shows that our method is significantly better than traditional algorithms in terms of accuracy (96.8%), false positive rate (2.1%), and response time (6.7 s). Full article

(This article belongs to the Special Issue Advances in Industrial Fire and Urban Fire Research: 2nd Edition)

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18 pages, 569 KiB

Open AccessReview

Integrating Virtual Reality, Augmented Reality, Mixed Reality, Extended Reality, and Simulation-Based Systems into Fire and Rescue Service Training: Current Practices and Future Directions

by Dusan Hancko, Andrea Majlingova and Danica Kačíková

Fire 2025, 8(6), 228; https://doi.org/10.3390/fire8060228 - 10 Jun 2025

Cited by 1

Abstract

The growing complexity and risk profile of fire and emergency incidents necessitate advanced training methodologies that go beyond traditional approaches. Live-fire drills and classroom-based instruction, while foundational, often fall short in providing safe, repeatable, and scalable training environments that accurately reflect the dynamic [...] Read more.

The growing complexity and risk profile of fire and emergency incidents necessitate advanced training methodologies that go beyond traditional approaches. Live-fire drills and classroom-based instruction, while foundational, often fall short in providing safe, repeatable, and scalable training environments that accurately reflect the dynamic nature of real-world emergencies. Recent advancements in immersive technologies, including virtual reality (VR), augmented reality (AR), mixed reality (MR), extended reality (XR), and simulation-based systems, offer promising alternatives to address these challenges. This review provides a comprehensive overview of the integration of VR, AR, MR, XR, and simulation technologies into firefighter and incident commander training. It examines current practices across fire services and emergency response agencies, highlighting the capabilities of immersive and interactive platforms to enhance operational readiness, decision-making, situational awareness, and team coordination. This paper analyzes the benefits of these technologies, such as increased safety, cost-efficiency, data-driven performance assessment, and personalized learning pathways, while also identifying persistent challenges, including technological limitations, realism gaps, and cultural barriers to adoption. Emerging trends, such as AI-enhanced scenario generation, biometric feedback integration, and cloud-based collaborative environments, are discussed as future directions that may further revolutionize fire service education. This review aims to support researchers, training developers, and emergency service stakeholders in understanding the evolving landscape of digital training solutions, with the goal of fostering more resilient, adaptive, and effective emergency response systems. Full article

(This article belongs to the Special Issue Firefighting Approaches and Extreme Wildfires)

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29 pages, 14072 KiB

Open AccessArticle

Performance Assessment of Fire-Damaged and CFRP-Repaired Bridge Columns Under Single Unit Truck Impact and Blast

by Qusai A. Alomari and Daniel G. Linzell

Fire 2025, 8(6), 227; https://doi.org/10.3390/fire8060227 - 9 Jun 2025

Abstract

Recent catastrophic bridge fire incidents have highlighted the critical need for effective post-fire assessment of bridges, thereby challenging the dominant practice of complete replacement following these destructive events. This study investigates the post-fire performance of bare, isolated, and Carbon Fiber Reinforced Polymer (CFRP)-repaired [...] Read more.

Recent catastrophic bridge fire incidents have highlighted the critical need for effective post-fire assessment of bridges, thereby challenging the dominant practice of complete replacement following these destructive events. This study investigates the post-fire performance of bare, isolated, and Carbon Fiber Reinforced Polymer (CFRP)-repaired Reinforced Concrete (RC) bridge columns under single-unit truck impact followed by air blast. This extreme loading scenario was deliberately selected given the increased vulnerability of bridge columns to this loading scenario in the recent few years. Three-dimensional Finite Element (FE) models of the structural system and surrounding environment were developed and validated in LS-DYNA. The effectiveness of two in-situ retrofitting schemes in mitigating damage and enhancing structural integrity of three column diameters under the selected multi-hazards was assessed. Results demonstrated that wrapping the bottom half of the column height prevents shear failure and significantly reduces the damage under the coupled impact and blast. In contrast, employing a combination of CFRP bars and externally bonded sheets showed limited enhancement on post-fire impact and blast performance. This study provides critical insights into the feasibility and efficacy of retrofitting bridge columns that have experienced fire, thus laying the groundwork for the reconsideration of current design and rehabilitation protocols. Full article

(This article belongs to the Special Issue Current Advances in the Assessment and Mitigation of Fire Risk in Buildings and Urban Areas: 2nd Edition)

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18 pages, 9341 KiB

Open AccessArticle

Oxidation Mechanisms of Electrolyte and Fire Gas Generation Laws During a Lithium-Ion Battery Thermal Runaway

by Yao Tian, Xia Zhang, Qing Xia and Zhaoyang Chen

Fire 2025, 8(6), 226; https://doi.org/10.3390/fire8060226 - 9 Jun 2025

Abstract

Lithium-ion batteries (LIBs) have come to hold ever greater significance across diverse fields. However, thermal runaway and associated fire incidents have undeniably constrained the application and development of LIBs. Consequently, gaining a profound understanding of the reaction mechanisms of LIB electrolytes during thermal [...] Read more.

Lithium-ion batteries (LIBs) have come to hold ever greater significance across diverse fields. However, thermal runaway and associated fire incidents have undeniably constrained the application and development of LIBs. Consequently, gaining a profound understanding of the reaction mechanisms of LIB electrolytes during thermal runaway is of critical importance for ensuring the fire protection of LIBs. In this study, quantum chemical calculations were employed to construct oxidation reaction models of electrolytes, and a comprehensive summary of the sources of fire gas generation during the thermal runaway of LIBs is presented. During the sequence of oxidation reactions, the -COH functional group emerged as the most critical intermediate product. Under conditions of low oxygen availability, it was prone to decompose into CO, whereas in the presence of sufficient oxygen, it could undergo further oxidation to form -COOH and subsequently decompose into CO₂. Moreover, the reaction chains associated with electrolyte oxidation were found to be highly intricate, characterized by multiple branches and a wide variety of intermediate products. Furthermore, an in-depth analysis was carried out on the generation mechanisms of several typical fire gases. The analysis revealed that CH₃OH and C₂H₅OH could be considered as the characteristic products of the oxidation reactions of DMC and DEC, respectively. It is anticipated that this research will provide a robust theoretical foundation for elucidating the complex reactions involved in LIB fires and offer reaction models for fire simulation purposes, thereby contributing to the enhancement of the safety and reliability of LIBs in various applications. Full article

(This article belongs to the Special Issue Advances in New Energy Materials and Fire Safety)

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11 pages, 1273 KiB

Open AccessArticle

Effects of Bioturbation by Earthworms on Litter Flammability in Young and Mature Afforested Stands

by Aneta Martinovská, Ondřej Mudrák and Jan Frouz

Fire 2025, 8(6), 225; https://doi.org/10.3390/fire8060225 - 6 Jun 2025

Abstract

The quantity, quality, and accumulation rate of plant litter play a key role in forest floor flammability and, by extension, fire regimes. The varying foliage properties of different tree species also determine litter’s decomposition and its accumulation on the forest floor. The removal [...] Read more.

The quantity, quality, and accumulation rate of plant litter play a key role in forest floor flammability and, by extension, fire regimes. The varying foliage properties of different tree species also determine litter’s decomposition and its accumulation on the forest floor. The removal of litter by soil fauna, i.e., bioturbation, depends on both the dominant tree species and the successional stage of the forest stand. This research involved laboratory mesocosm experiments aiming to determine the effects of litter quality and earthworm activity on the flammability of the forest floor material at different successional ages. The mesocosms simulated the planting of four tree species (the broadleaf species Alnus glutinosa (L.) Gaertn. (Black alder) and Quercus robur L. (English oak) and the conifers Picea omorika (Pančić) Purk. (Serbian spruce) and Pinus nigra J.F. Arnold (Austrian pine)) at a reclamation site near Sokolov (NW Czechia). The mesocosms contained litter from these different tree species, placed directly on overburden soil (immature soil) or on well-developed Oe and A layers (mature soil), inoculated or not inoculated with earthworms, and incubated for 4 months. The surface material in the mesocosms was then subjected to simulated burn events, and the fire path and soil temperature changes were recorded. Burn testing showed that litter type (tree species) and soil maturity significantly influenced flammability. Pine had longer burning times and burning paths and higher post-burn temperatures than those of the other tree species. The immature soil with earthworms had significantly shorter burning times, whereas in the mature soil, earthworms had no effect. We conclude that earthworms have a significant, immediate effect on the litter flammability of immature soils. Full article

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22 pages, 6584 KiB

Open AccessArticle

Fire Test Study and FDS Verification of Spray Water Volume for Small-Sized Bookstores in the Revitalization of Historical Buildings

by Peng Du, Jing Liu, Cheng Zhang, Zhixin Zheng, Guangyue Gu, Jiaming Zhao, Feng Yan, Songtao Liu, Rutian Li and Jun Zhang

Fire 2025, 8(6), 224; https://doi.org/10.3390/fire8060224 - 3 Jun 2025

Abstract

Small bookstores constructed before the 1970s have a high fire risk in the context of the revitalization of historical buildings; while the setup of simple sprinklers is an effective and cheap method of extinguishing fires, the parameters of the sprinklers are uncertain. In [...] Read more.

Small bookstores constructed before the 1970s have a high fire risk in the context of the revitalization of historical buildings; while the setup of simple sprinklers is an effective and cheap method of extinguishing fires, the parameters of the sprinklers are uncertain. In this study, small bookstores in Beijing were selected, and physical combustion experiments with/without a sprinkler system were carried out following the provisions of the Code for the Design of Sprinkler Systems. After the experiments, an FDS model was set up using fire dynamics software. The results show that the total heat release rate (HRR) of books and desks is related to the square of time, with a coefficient of 2.528 × 10⁻⁶, and the maximum heat release rate is 40 KW. Unlike the standard test, the physical combustion experiment is significantly affected by the space. According to numerical simulations, when the sprinkler flow velocity is 60~100 L/min, the water consumption of the sprinkler is 195~218 L. This study lays the foundation for the analysis of the combustion characteristics of small bookstores and provides data support for the installation of simple sprinkler systems in small bookstores. Full article

(This article belongs to the Special Issue Confined Space Fire Safety and Alternative Fuel Fire Safety)

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36 pages, 2962 KiB

Open AccessReview

Safety Methods for Mitigating Thermal Runaway of Lithium-Ion Batteries—A Review

by Jun Deng, Zhen Hu, Jian Chen, Jingyu Zhao and Zujin Bai

Fire 2025, 8(6), 223; https://doi.org/10.3390/fire8060223 - 31 May 2025

Abstract

Lithium-ion batteries (LIBs) are widely used as energy storage units in electric vehicles, mobile phones, and other electric devices due to their high voltage, large capacity, and long cycle life. Lithium-ion batteries are prone to thermal runway (TR), resulting in fires and explosions, [...] Read more.

Lithium-ion batteries (LIBs) are widely used as energy storage units in electric vehicles, mobile phones, and other electric devices due to their high voltage, large capacity, and long cycle life. Lithium-ion batteries are prone to thermal runway (TR), resulting in fires and explosions, which can seriously hinder the commercial development of LIBs. A series of safety methods has been studied to prevent TR of LIBs. The safety methods for suppressing TR in LIBs were reviewed, including safety equipment method, material modification method, thermal management method, and cooling method. The mechanism, advantages and disadvantages, and future applications of the TR suppression method are discussed. The effectiveness of the proposed safety method was evaluated through technical analysis and experimental testing, and the inhibitory effects of different safety methods on battery TR were summarized. The future trend of suppressing TR is discussed by summarizing and generalizing existing technologies for suppressing thermal runaway. This study provides a reference for exploring more effective methods to mitigate TR in the future. Full article

(This article belongs to the Special Issue Advances in Thermal Energy Storage in Fire Prevention and Control)

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13 pages, 2673 KiB

Open AccessArticle

Longitudinal Ceiling Temperature Profile in an Inclined Channel Induced by a Wall-Attached Fire

by Xubo Huang, Yongfeng Zhang, Wei Wang and Zhenxiang Tao

Fire 2025, 8(6), 222; https://doi.org/10.3390/fire8060222 - 31 May 2025

Abstract

Channel fire poses a great threat to personnel safety and structural strength, in which the temperature profile is worthy of attention. In this paper, the longitudinal temperature profile of a ceiling jet induced by a wall-attached fire with different channel slopes was experimentally [...] Read more.

Channel fire poses a great threat to personnel safety and structural strength, in which the temperature profile is worthy of attention. In this paper, the longitudinal temperature profile of a ceiling jet induced by a wall-attached fire with different channel slopes was experimentally investigated using a 1:8 reduced-scale channel. The results show the following: (1) For channel fire with a horizontal ceiling, the influence of the burner aspect ratio and source-ceiling height on the temperature profile is monotonous in the cases considered in this work. With a larger burner aspect ratio and larger source-ceiling distance, more ambient air could be entrained; hence, the longitudinal temperature under the ceiling decays faster. (2) For channel fire with an inclined ceiling, when the burner aspect ratio and source-ceiling distance remain constant, the asymmetric entrainment induced by the flame under larger channel slope leads to more hot smoke being transported upstream. Consequently, the temperature profile is not symmetric, with higher temperatures upstream and lower temperatures downstream. (3) Combining the influence of the burner aspect ratios, source-ceiling distance, and burner aspect ratio, the characteristic length scale was modified. Based on this, a model describing the ceiling temperature profile was proposed and then verified with previous data. Full article

(This article belongs to the Special Issue Advances in Fire Science and Fire Protection Engineering)

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20 pages, 3652 KiB

Open AccessArticle

Hydroclimatic and Land Use Drivers of Wildfire Risk in the Colombian Caribbean

by Yiniva Camargo Caicedo, Sindy Bolaño-Diaz, Geraldine M. Pomares-Meza, Manuel Pérez-Pérez, Tionhonkélé Drissa Soro, Tomás R. Bolaño-Ortiz and Andrés M. Vélez-Pereira

Fire 2025, 8(6), 221; https://doi.org/10.3390/fire8060221 - 31 May 2025

Abstract

Fire-driven land cover change has generated a paradox: while habitat fragmentation from agriculture, livestock, and urban expansion has reduced natural fire occurrences, human-induced ignitions have increased wildfire frequency and intensity. In northern Colombia’s Magdalena Department, most of the territory faces moderate to high [...] Read more.

Fire-driven land cover change has generated a paradox: while habitat fragmentation from agriculture, livestock, and urban expansion has reduced natural fire occurrences, human-induced ignitions have increased wildfire frequency and intensity. In northern Colombia’s Magdalena Department, most of the territory faces moderate to high wildfire risk, especially during recurrent dry seasons and periods of below-average precipitation. However, knowledge of wildfire spatiotemporal occurrence and its drivers remains scarce. This work addresses this gap by identifying fire-prone zones and analyzing the influence of climate and vegetation in the Magdalena Department. Fire-prone zones were identified using the Getis–Ord Gi* method over fire density and burned area data from 2001 to 2023; then, they were analyzed with seasonally aggregated hydroclimatic indices via logistic regression to quantify their influence on wildfires. Vegetation susceptibility was assessed using geostatistics, obtaining land cover types most affected by fire and their degree of fragmentation. Fire-prone zones in the Magdalena Department covered ~744.35 km² (3.21%), with a weak but significant (τ = 0.20, p < 0.01) degree of coincidence between classification based on fire density, as pre-fire variable, and burned area, as a post-fire variable. Temporally, fire probability increased during the dry season, driven by short-lagged precursors such as Dry Spell Length and precipitation from the preceding wet season. Fire-prone zones were dominated by pastures (62.39%), grasslands and shrublands (19.61%) and forests (15.74%), and exhibited larger, more complex high-risk patches, despite similar spatial connectedness with non-fire-prone zones. These findings enhance wildfire vulnerability understanding, contributing to risk-based territorial planning. Full article

(This article belongs to the Section Fire Science Models, Remote Sensing, and Data)

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17 pages, 420 KiB

Open AccessArticle

Volunteer Motivation in Firefighting Organisations: A Case of the Slovenian Firefighters Association

by Tatjana Kozjek, Uroška Zorec Klemenčič and Lan Umek

Fire 2025, 8(6), 220; https://doi.org/10.3390/fire8060220 - 30 May 2025

Abstract

Volunteer firefighters play an important role in the provision of emergency services in Slovenia, where most of firefighters work on a voluntary basis. In many countries, however, volunteering is in decline due to demographic, social and organisational constraints. To maintain this important function, [...] Read more.

Volunteer firefighters play an important role in the provision of emergency services in Slovenia, where most of firefighters work on a voluntary basis. In many countries, however, volunteering is in decline due to demographic, social and organisational constraints. To maintain this important function, it is important to understand the motivations that drive individuals to join and stay in the volunteer fire service. This study examines the motivational factors that influence Slovenian volunteer firefighters, with a particular focus on fire service support, leadership practices and demographic differences. A quantitative survey was conducted among 244 volunteer firefighters from 22 fire brigades. The data were analysed using descriptive statistics, t-tests, Spearman’s rank correlation and binary logistic regression. The results show that many volunteer firefighters are motivated by the challenge of working under stress and in situations of controlled risk. However, this motivation decreases with age, as older members show less interest in adrenaline-driven tasks. Men show a greater preference for action-oriented tasks, including emergency response, equipment handling and physical engagement. In contrast, women place slightly more emphasis on social connections within the brigade. Volunteers who feel included in decision-making processes and experience cooperative, participative leadership are more likely to remain engaged. Those who are motivated by physical activity are more likely to stay, while those who are primarily motivated by social recognition or status are more likely to leave. These findings contribute to the literature on volunteering in high-risk contexts. Tailored recruitment and retention strategies that take into account age, gender and leadership dynamics can help fire services build more engaged and sustainable volunteer teams. Full article

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