bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of VOCs on the auto-ignition of Mediterranean plants
Authors: Brudo Agathe , Coudour Bruno , Bruneau Lucas , Lemée Laurent , Dédaldéchamp Fabienne
Published: November 2024

In view of the increasing frequency of extreme fires, this work proposes to identify the compounds that promote the auto-ignition of plants and thus the spread of wildfires. The objective is to better understand the biochemical and thermochemical aspects of wildfire propagation in order to better anticipate extreme fires such as megafires and eruptive fires and then to size up the means of firefighting. This study supports another project which aims at developing a dispersion model to determine the relationship between the accumulation of VOCs and eruptive fires in confined topographies. The originality of this study lies in its interdisciplinary approach using chemical and biological analyses. In this work, emissions from dead Rosmarinus officinalis were studied. Preliminary results show an increase in oxygenated molecules and a decrease in non-oxygenated molecules in the emissions of dead plants compared to control living plants. In perspective, it is planned to study different living plants submitted to different levels of hydric stress: R. officinalis and C. albidus, representative of Mediterranean Basin and L. vulgare as a non-Mediterranean species to compare the compositions of the gases emitted at high temperature close to auto-ignition.
Characterisation of fire smoke emissions from fire retardant wood
Authors: Arinaitwe Evalyne , Rex Johannes , Wilkens Konrad , Malmborg Vilhelm , Pagels Joakim , McNamee Margaret
Published: November 2024

Fire retardants are extensively used to reduce the flammability (combustibility) of wood–based construction materials in an effort to improve fire safety of buildings. However, little is known of the composition and potential risks to human health of smoke emissions produced from combustion of fire retardant treated wood. To help understand the risk to human health, fire smoke emissions produced from three different wood materials; wood without fire retardant, fire retardant wood, and aged fire retardant wood were analysed. The materials were exposed to a heat flux of 50 kW/m2 in a cone calorimeter according to ISO standard 5660-1. The fire gases and soot, measured as equivalent black carbon (eBC), produced were quantified using Fourier Transform Infrared (FTIR) spectroscopy and an aethalometer, respectively. Our findings show that fire retardant wood produces substantially less soot mass than non-fire-retardant wood. However, the fire retardant wood produces more toxic gases, e.g. HCl, than both the wood without fire retardant and aged fire retardant wood.
Sensitivity Study of Decomposing Carbon Fiber Epoxy Composites Model
Authors: Bran Anleu Gabriela , Winters Caroline , Roybal Daniel , Scott Sarah N.
Published: November 2024

The high strength-to-weight ratio of carbon fiber epoxy composites makes these materials ideal for automotive and aeronautical applications. However, carbon fibers and epoxy in the composite are a source of fuel when exposed to a fire environment. To understand the safety risk of these materials, a numerical model that accounts for the thermal properties of each constituent in the composite was developed to simulate the decomposition process of carbon fiber epoxy composites in fire environments. The numerical model was then compared to experimental temperature measurements of composites materials subjected to a low and a high radiant heating rate. In addition, a sensitivity analysis was performed to understand the uncertainties associated with the model input parameters. These results will help further understand thermal behavior during the decomposition process and serve as a tool to improve future models that will enable the mitigation of any safety concerns associated with these materials.
Reaction to fire of decorative moss-imitating panels with moss, lichens and algae
Authors: Węgrzyński Wojciech , Węgrzyńska Monika , Miechówka Bartosz , Bielawski Jakub , Papis Bartłomiej
Published: November 2024

Moss-imitating panels for interior linings were tested with standard reaction-to-fire methods – three with Cone Calorimetry and all five with Single Burning Item (SBI). Different types of organisms were chosen, representing moss, lichen and algae. Panels with different species have exhibited vastly different fire behaviours. The moss was closest to the previously observed living wall behaviour, with rapid fire spread over the surface and a charred remnant layer formation. Algae burned only in the presence of the external flame source, but the shape (balls) allowed fire propagation to the sub-structure made of combustible MDF FR board. Lichens have not contributed to the fire and acted as an insulative layer between the fire and the sub-structure. Detailed measurements of the reaction to fire are presented and discussed. The research indicates potential challenges for architects and fire safety engineers, to whom the solutions with vastly different properties may be marketed under the same trade name, “moss panel”, as without experience in biology, distinguishing between the samples was difficult.
Numerical and experimental investigation of compartment fires
Authors: Mehaddi Rabah , Lafdal Bouaza , Boulet Pascal
Published: November 2024

The present study focuses on under-ventilated compartment fires, by analysing the results of an experimental and numerical study about fires issuing from heptane pools in a compartment with an open door. The key parameters in this case are the ventilation factor (based on the door height and its area) and the pool fire diameter. To analyse the combustion regimes, the fire Heat Release Rate (HRR) is split into two parts, namely, the heat released inside and outside the compartment. To quantify these quantities, two experimental methods have been combined. The first one is based on temperature measurements inside the compartment. The second one combines measurements for the heat fluxes outside the compartment and images taken with visible cameras that provide the flame shape outside the compartment and lead to the corresponding total released flux. The experimental data have been compared to dedicated numerical simulations carried out with the CFD code Fire Dynamics Simulator. These comparisons have revealed that in a well-ventilated or moderately under-ventilated regime, integral quantities such as mean temperature, fire heat release rate inside and outside the room appear to be well predicted by the simulations. However, under the same conditions, the temperature profiles show differences that can be locally significant. This observation might be explained by a difficulty in correctly reproducing the flame dynamics and the air flow entering through the door. Furthermore, in the severely under-ventilated case, the temporal evolution of the average quantities (HRR and mean temperatures) are very poorly estimated by the simulations, as well as the local distributions. In this case the simulations predict that the combustion of all the combustible vapours occurs at the door, which does not correspond to the physical observations. Therefore, modifications of the CFD code are required to improve the simulations, probably also involving dedicated efforts on the ignition and extinction sub-models.
Laminar smoke point-based analysis of soot production in liquid-fuelled laminar coflow non-premixed flames
Authors: Consalvi Jean-Louis , Nmira Fatiha
Published: November 2024

This article presents a smoke point-based (SP) analysis of experimental data of the literature in laminar coflow non-premixed flames fuelled by gaseous and pre-vaporized liquid fuels. As observed by Marstein and de Ris (Proc. Combust. Inst. 20 (1984) 1637) for gaseous fuels, the peak of radially-integrated soot volume fraction (SVF), Fv
, normalized by the ratio of flame length, Lf
, to the laminar SP flame height, Lsp
, is found to be a constant roughly independent of the fuel. For mixtures containing aromatics, this scaling is sensitive to the uncertainties on the very short Lsp
of aromatics, suggesting that a direct measurement is preferable rather than determining the mixture Lsp
from those of the mixture component fuels. The results obtained in this work support that that the current formulation of SP-based soot models, where the soot formation (SF) rate is calibrated for ethylene and extended to other fuels by considering that it scales with the inverse of Lsp
, can be directly applied to liquid fuels, despite different soot growth mechanisms.
An experimental study on the heating and burning of a binary liquid mixture in a pool fire
Authors: Xie En , Mehaddi Rabah , Terrei Lucas , Beji Tarek
Published: November 2024

The paper presents experimental measurements for the transient profiles of burning rates and liquid temperatures (at different depths below the surface) in pool fires. Steel square burners with two different side lengths are selected: 10.5 and 15.0 cm. The burner is 5 cm deep and the initial fuel height is about 4.6 cm. At 10°C, the fuel is a mixture of cyclohexane and methanol with a molar composition of about 50%-50%. Under these conditions, there is a top cyclohexane-rich layer and a bottom methanol-rich layer. In the initial transient and steady-state periods, the burning is slightly lower than that of pure cyclohexane due to the presence of methanol in the top layer. Then, a sudden more intense burning occurs due to the expansion of methanol vapor reaching the surface. A semi-empirical model is proposed to predict the onset of this event, assuming that it corresponds to the interface between the two layers reaching the azeotropic point of the blend. A second steady-state period is subsequently established, corresponding to the burning of a well-mixed blend of both liquids at the azeotropic point, as measured by the thermocouples immersed into the liquid.
Repeat Fire Tests of Upholstered Furniture: Influence of Experimental Conditions
Authors: Morrisset David , Reep Jonathan , Ojwang Ian , Hadden Rory M. , Law Angus
Published: November 2024

A series of experiments was conducted to illustrate the influence of different experimental conditions on the statistical variation observed for furniture-scale calorimetry. Commercially available upholstered chairs were independently assessed using different ignition techniques, both with or without the presence of a wall corner. For each experiment, heat release rate (HRR), gaseous emission yields (e.g., CO), and heat fluxes (HFs) from the fuel package were compared. Measurements made were used to link the burning behaviour to physical occurrence and identified the influence each experimental configuration had on the resulting behaviour. The time resolved HRR and CO yield were found to be largely unaffected by the presence of a wall corner, while the radiant heat flux from the item was increased with a wall corner. Both the HRR and CO yield in time showed a dependence on ignition location – however these differences can be contextualized by the use of key events that drive the burning process and global burning regimes.
Benchmarking an engineering model to estimate hot gas layer interface height
Authors: Johansson N
Published: November 2024

An engineering model for estimating hot gas layer height is presented. The model is based on several sub-models, thus necessitating benchmarking against experimental data. Results from the model are compared to data from three different series of enclosure fire tests. The results indicate a strong correlation between the proposed model and the experimental observations, with an average error of less than 5%. The model demonstrates robustness in estimating hot gas layer interface heights, presenting valuable applications for fire safety design and analysis.
Experimental study of fire propagation on sloped roof with building applied photovoltaics
Authors: Stølen Reidar , Siren Fjærestad Janne , Fjellgaard Mikalsen Ragni , Jomaas Grunde
Published: November 2024

Photovoltaic modules have been shown to influence how a fire propagates across a flat roof, but the circumstances for which building attached photovoltaic (BAPV) modules promote fire propagation on a sloped roof is not studied in detail. Therefore, a series of small-medium- and large-scale experiments on a sloped roof with a BROOF(t2)-rated bituminous roof membrane on a wood chipboard substrate has been performed. Steel plates mimicking non-combustible photovoltaic (PV) modules were placed at different distances above the roof. Different sized wood cribs placed in the gap between the roof and the PV module were used as the ignition source. Similarly to findings for flat roofs, the experiments showed that the gap distance and the size of the ignition source are key factors for how far the fire propagates from the starting point. This supports that BAPV installations affect the fire dynamics on roofs. As such, the complete system of roof composition and PV installation needs to be considered as a whole to ensure adequate fire safety levels.
Numerical assessment of smoke control systems in high-rack warehouses: the Spanish perspective
Authors: Rengel Borja , Dréan Virginie , Guillaume Eric
Published: November 2024

The smoke control systems in high-rack warehouses are conceived to assist in firefighting efforts, providing acceptable safety conditions for firefighter intervention. Although the Spanish standard proposes a system based on dividing the space into smoke reservoirs using smoke curtains, recently performance based studies are being carried out to justify alternative systems to the standard one without smoke curtains, with low-level air intake and a lower number of outlets. This study compares the performance of both systems against different growth rates and ventilation areas by conducting 12 numerical experiments performed with Fire Dynamics Simulator (FDS).
Relevance of the steady laminar flamelet model for the large-eddy simulation of a reactive plume
Authors: Boyer Germain , Chikkabikkodu Uday , Aguilera Javier , Richard Franck , Mura Arnaud
Published: November 2024

The relevance of the steady laminar flamelet model (SLFM) is analyzed and discussed on the basis of computational results issued from the large-eddy simulation (LES) of a 30 cm diameter methanol pool fire. In a first step of the analysis, the computational results are assessed versus available experimental data: a satisfactory level of agreement is obtained. Then, the computational database is used to analyze the combustion regimes and model response.
Repeatability Assessment in Tunnel Fire Experiments
Authors: Morales Mere J A , Madsen D , Johansson N , Ronchi E
Published: November 2024

A medium-scale experimental setup located in Revinge, Sweden, is used to generate new repeated experimental datasets focussed on measuring a set of key variables, including time-temperature curves and temperature profiles. A total of 6 repeated fire tests were conducted and are here used to exemplify typical issues associated with repeatability, uncertainty and variability in tunnel fire experiments. A key aspect considered in this work is the smoke stratification among repeated experiments and how fire behaviour can be affected by boundary conditions. This work is important to facilitate future efforts to collect high-quality tunnel fire data including a quantitative assessment of the experimental uncertainty, data that will be useful for validation of tunnel fire models.
Model scale exposed timber compartment fire experiments with wood crib fuel load
Authors: Karannagodage Chamith , Schmid Joachim , Klippel Michael , Kleinhenz Miriam , Fahrni Reto , Frangi Andrea , Viertel Martin
Published: November 2024

A series of model-scale compartment fire experiments were performed to investigate the influence of different exposed timber area and configurations on the compartment fire dynamics. The experimental setup and part of the instrumentation (temperature, mass loss) are presented. The main findings from the compartment fire experiments with exposed timber are discussed with the current compartment fire experimental knowledge. The experimental results showed that the presence of exposed timber surfaces except for the exposed timber ceiling appears to influence the temperature development in the compartment and the fire duration. The number of exposed timber surfaces alone was not the governing parameter of self-extinguishment and it appears to be a function of geometry, openings and moveable fuel load.
Large-scale experimental study of interaction between fallout of tempered glass façade and enclosure fire dynamics
Authors: Chen H N , Wang Y
Published: November 2024

This work presents several large-scale experiments on the interaction between fallout of tempered glass façade and enclosure fire dynamics. The experimental setup consisted of a compartment (1.8 × 1.4 × 1.4 m3) with a fixed glass frame on one side to install a glass façade, which can contain 4 pieces of 660 × 630 mm2 single-layer tempered glass at most. Some experiments were designed to investigate the influence of different glass positions on the framework on the breakage time, surface temperature, and heat flux. The flashover in all tests occurred before tempered glass breakage. Generally, the upper-installed glasses may lead to an earlier flashover but increase the breaking time. The first breakage normally occurred on the upper layer. The analysis indicated that with the lower opening on the framework, the critical time of flashover was 230 s, and the breakage occurred at 242 s. With the upper opening on the framework, the critical time of flashover was 148 s, but the breakage occurred at 296 s. Meanwhile, the maximum temperature differences between the central and shaded areas exceeded 150 ℃ in all cases, resulting in tempered glass breakage and fallout. The critical total heat flux was 88 kW/m2 but the radiative heat flux accounted for only 12.5% of the total heat flux before breakage.
Study of fire characteristics of forest vegetation in the Atlantic coastal region of Norway
Authors: Rosnes Magne , Synnøve Skilbred Ellen , Aamodt Edvard , Ståle Ertesvåg Ivar , Fjellgaard Mikalsen Ragni
Published: November 2024

Understanding of wildfire risk requires an understanding of the natural species’ fire dynamics. This study investigates fire characteristics of common wildland species in Norwegian forests – stair-step moss, lingonberry shrub, juniper, bilberry, and heather. Cone calorimetry experiments were conducted after conditioning samples to similar moisture content. Stair-step moss and bilberry stems exhibited longer burning times and lower peak heat release rates, suggesting a slower, more sustained combustion. Heather, despite age differences, showed similar fire behaviours, indicating moisture content’s role in wildfire risk. Evergreens displayed the most intense fire development, with juniper potentially acting as a ladder species for vertical fire spread.
Experimental investigations on ember- and radiation-coupled ignition in fuel beds
Authors: Duong Dana , Gomaa Islam
Published: November 2024

Experimental tests were conducted to examine the behaviour of ignition in ember and radiant heat-coupled ignition of common construction material fuel beds. Embers were deposited sequentially onto various fuel beds at an ember flux rate of ∼2.1 pcs/min at various heat fluxes. Results show that ember and radiant heat-coupled conditions without a pilot had a slightly lower heat flux to flaming ignition of plywood compared to the critical heat flux for piloted flaming ignition value of previous studies. Increasing the initial radiant energy exposure time further decreased the critical heat flux for materials such as plywood, but for others, such as polyisocyanurate, the sample thermally decomposed, leading to a decrease in ignition probability.
Who is Exposed to Nordic WUI Fires?
Authors: Vermina Plathner Frida
Published: November 2024

The impact of wildfire is not only determined by fire magnitude, but also by the predispositions of those who are affected, which is described by differences in social vulnerability. In this study, Swedish event reports on Wildland-Urban Interface fires that occurred between 1996 and 2022 were used to identify features of social vulnerability that are central to a Nordic setting. Results on both census tract scale and on household scale highlight that living in a sparsely populated area increases vulnerability to wildfire.
Prescribed Burns and UAV Drone Analysis: Towards A Coupled Wind-Fire Spread Model.
Authors: Gill Fearghal , Valencia Dr Andres , Baker Dr Greg
Published: November 2024

Wildfires present significant challenges globally, necessitating precise fire spread models to comprehend and mitigate their extensive impacts. Various ‘reduced’ physics simulators, such as FDS (Fire Dynamics Simulator) in level set mode, CAWFE, and WRF-Fire, offer promising capabilities for landscape-scale simulations through the parameterization of heat transfer to fuels using empirical/semi-empirical rate of spread (ESE-RoS) models. However, the introduction of heat/mass from the fire front in coupled systems alters wind patterns, which is not considered in the derivation of ESE-RoS models. This discrepancy presents a physical inconsistency when using ESE-RoS models in coupled simulators. To address this issue, this paper outlines preliminary progress towards developing an empirical rate of spread (RoS) model using UAV drone footage and experimental data from three prescribed burns on agricultural crop stubble. The analysis of the drone footage captures instantaneous RoS and links it to overhead wind speed to account for the coupled nature of wind/fire interactions and their subsequent influence on RoS. The completed model’s integration into FDS (in level set mode) is planned, focusing on assessing its accuracy and applicability in fire spread modelling
Analysis of the effectiveness of WUI shaded fuel breaks
Authors: Vacca Pascale , Dossi Simona , Planas Eulàlia , Pastor Elsa
Published: November 2024

The effectiveness of WUI fuel management practices aimed at protecting communities, infrastructures, and homes is analysed, specifically considering prescriptions for shaded fuel breaks of the regions of Catalonia (Spain) and Pyrénées-Orientales (France). Fire spread through fuel breaks is simulated under different environmental and wildfire exposure conditions in FDS (Fire Dynamics Simulator). The French regulated fuel breaks are simulated as 50 m wide areas with a density of 600 trees/ha, and the Catalan regulated breaks as 25 m wide areas with 300 trees/ha. The analysis allows a quantitative comparison of the fire protection provided by different fuel management regulations. Results show that the analysed shaded fuel breaks meet the objective of modifying fire behaviour and reducing emitted heat fluxes and temperatures, although, in some cases, not sufficiently, thus exposing assets to untenable environments, with possible direct flame contact or exposure to high heat fluxes and temperatures. Analysed scenarios also highlight that tree density within the fuel break can impact fire spread through surface fuels. Obtained results show that a 25 m wide break, as the one from the Catalan regulations, is not sufficient in several scenarios; additionally, when exposed to high wind speeds (7.8 m/s), a 50 m wide fuel break (French regulations) is also insufficient.
Modelling of wildland fire spread using empirical approach analysing the effect of moisture, wind, and slope
Authors: Zhang Enya , Bradford Tracy , Liu Weiming , Asimakopoulou Eleni
Published: November 2024

Due to rapid climate change, wildfires are an increasing risk to human life and economy. To prevent their occurrence and reduce their intensity, computational methods have been developed to study and simulate wildfire spread. Medium scale experiments and thermogravimetric analysis is conducted for Pinus Sylvestris Needle. Results from numerical analysis using level set model were validated using experimental data. And a parametric study was performed to study the effect of fuel moisture fraction, wind and slope to surface vegetation fire behaviour. Numerical data, including temperature and rate of spread, are analysed and limitations of model is also discussed.
Simulation of Thermal Infrared Images from Simulated Fire Scenes
Authors: Paugam Ronan , Bordbar Hadi , Àgueda Alba , Regaieg Omar , Chavanon Eric , Lauret Nicolas , Gastellu-Etchegorry Jean-Philippe , Wooster Martin
Published: November 2024

We summarize here the current development of a simulation strategy aiming at creating a 3D virtual fire lab that can model radiative transfer in simulated fire scenes, and render images in the infrared spectrum. While the end objective is to simulate open landscape scale vegetation fires to help improving fire monitoring Earth Observation products, this work presents a validation exercise performed using a small scale fire scene focusing on flame emission. The fire scene is simulated using the Fire Dynamics Simulator (FDS) model to generate 3D distribution of temperature, soot volume fraction, and CO2, CO and H2O gases molar fractions. It is then passed to the 3D Discrete Anisotropic Radiative Transfer (DART) model to simulate radiative transfer in multiple infrared bands at a spectral resolution of 0.25 μm, and render images or intensity spectrum in the infra red spectra that can be compared against direct measurements.
Estimation of 3D Shape and Volume of Fire Plumes from Multiple Views
Authors: Blanco J A , Pardàs M , Casas J R , Paugam R , Àgueda A , Wagner J , Parsons R A , Planas E
Published: November 2024

This study evaluates deep-learning and Shape from Silhouette (SfS) methods for 3D reconstruction of smoke plumes. It demonstrates the deep-learning method’s superiority in cases with limited camera views and calibration data, achieving high-quality reconstructions of semi-transparent smoke without precise calibration. The research emphasizes the significance of pre-processing and data appearance for neural network efficacy. By improving 3D reconstruction techniques, this work aids in advancing wildfire tracking and environmental analysis, offering a practical approach for real-world applications in fire science.
Wavelet analysis to reveal fluctuations in near-surface temperature and wind speed during the FireFlux I experimental fire
Authors: Antolin William P. , Rochoux Mélanie C. , Moigne Patrick Le
Published: November 2024

Field-scale wildland fire experiments are needed to validate coupled atmosphere/fire models and to assess their ability to represent wildland fire dynamics, including surface fire spread and perturbed local meteorology in the immediate vicinity of the spreading fire. These experiments provide access to the in situ turbulence observations needed to understand the local turbulent structures, which are impacted by the strong heat fluxes released by the fire and by the presence of forest canopies. In this paper, we present a wavelet analysis approach to extract turbulence information, based on frequency localization, from observed time series of temperature and wind speed during the FireFlux I experimental fire. Wavelets are used to robustly decompose the time series of interest into mean and fluctuation components by separating scales in the frequency space, where it is possible to identify the scales that contribute most to the energy spectrum. Fluctuations in temperature and wind speed are then used as input to a quadrant analysis to characterize the possible interactions between variables as the fire front passes, and to identify the most dominant events such as sweeps, puffing and local cooling. Wavelets therefore have great potential for observation-model comparison, i.e. for assessing the ability of coupled atmosphere-fire models to represent realistic turbulence patterns associated with atmosphere-canopy-fire interactions.
Particle Size Prediction Method for Fire or Nuisance Event using a Simple Photoelectric Detector
Authors: Özyurt Osman
Published: November 2024

This study demonstrates that a simple smoke detector with minimal components can be used to estimate the particle size of fires or nuisance incidents. Machine learning (ML) models were created using scattered light data. Various test materials such as wood, cotton, polyurethane foam, cigarette, N-heptane, printed circuit board (PCB), paraffin, polyalpha olefin (PAO), di-ethyl hexyl-sebacate (DEHS), plaster powder, and cement dust were used in the experiments. The proposed prediction method was tested against completely unknown particles of cigarette, PAO, PCB, and plaster powder, which were not used in the training. The particle size prediction capability of forward, backward, and side scattering of light at 980 nm was investigated using ML models with time correlation function (TCF) data. The prediction errors of the best ML model for particle median sizes ranged from 0.4% to 35.1%. Traditional simple smoke detectors using the proposed methodologies can measure the median particle size and volume concentration, thereby effectively suppressing false alarms.
CO – hazardous gas indicates hidden smoldering fires
Authors: Wegner S , Ruhe H , Klein K , Braun F , Lange J , Kampmeier B , Wellisch A , Neske M
Published: November 2024

The growing importance of wood construction presents new challenges for fire departments and leads to new areas of responsibility and research. In particular, hidden smoldering fires can damage building structures and release toxic gases if not detected. This study investigates the detection of cavity fires in modern wood construction using carbon dioxide (CO) gas measurement technology. For this purpose, the propagation within the compartment and to adjacent compartments is investigated. The measurement is performed both through the plaster layers and with copper tubes, allowing measurements directly on the insulation material. For gas measurement in this paper, only fire service gas meters have been used.
A Study on Domestic Metal Waste Fire Extinguishing Experiment Against Metal Fires
Authors: Park TH , Kim TS , Yang JH , Kwon JS
Published: November 2024

There are no test standards in Korea for effective suppression of metal fires. In addition, metal dust generated during the aluminium recycling process is easily exposed to fire. Experiments were conducted with the expended vermiculite and wetting agent selected according to ISO 7165 standards and samples collected from factories. In addition, additional experiments were conducted according to KS F 2271 standards to find out the hazards of field workers.
Limits of assisted evacuation considering the safety of caregivers and impact of smoke control at small-scale older people’s welfare facilities
Authors: Minegishi Yoshikazu
Published: November 2024

This study investigated the limits of caregivers’ assistance during evacuations in small-scale older people welfare facilities, considering their safety and the impact of smoke control. Using virtual reality experiments, caregivers’ behavior during assistive evacuation was examined across different smoke-controlled scenarios. The participants, fire safety professionals, performed two evacuation procedures: “Attend,” by guiding residents outside, and “Refuge,” by having the residents stay inside. Results showed successful evacuation when smoke control measures were implemented, emphasizing their necessity for ensuring caregiver and resident safety during emergencies. Difficulties included loss of a sense of direction, smoke visibility, and challenges in assisting residents, highlighting the complexity of real-life scenarios. Effective smoke control measures are crucial for facilitating successful evacuations in small-scale older people welfare facilities.
Using CO and HCN as surrogates for multiple gases in fire toxicity calculations
Authors: Hostikka Simo , Linna Antti
Published: November 2024

Engineering analyses of fire toxicity are often limited to the production and transport of carbon monoxide and hydrogen cyanide, despite the broader range of gases in the Purser’s formulation for the fractional effective dose (FED). In this work, we show how these two gases can be used as surrogates for the other gases. We validate the method by measuring the yields of asphyxiant and irritant gases for five fuels, assigning them to a source of a small room fire and carrying out CFD predictions of FED using full and simplified schemes of gas species. Results indicate that replacing the full list of species with surrogates leads to less than 6 % relative error while simplifying the user input considerably and saving computational resources.
De-gendering firefighting: exploring risk perception and psychological resilience
Authors: Cuesta Arturo , Alvear Daniel , Balboa Adriana , Ortiz Gemma
Published: November 2024

This study explores psychological differences between male and female firefighters. A convenience sample of 202 firefighters (62 females) filled out an anonymous web-based survey designed to capture self-repots on risk propensity, risk tolerance, resilience and coping resilience. Overall small differences were found suggesting that the hypothetical gender discrepancies may be reduced in firefighting occupational contexts. Further research is needed to confirm this.
Determinants of Response to Fire Incidents in the Informal Settlements: A Case of Jhuggi Jhonpdi Clusters in Delhi, India
Authors: Karmakar Satorupa , Sharma Upasna , Lange David
Published: November 2024

Urban fires are exacerbated by global urbanisation trends, as characterised by dense and unplanned settlements in the global south. The contribution of flammable building materials, narrow lanes and an inability/unwillingness to adhere to the building regulations as the primary drivers behind elevating fire risk in informal settlements is well studied. Considering the impact of human behaviour during and after fire, this study draws insights from informal settlements in Delhi. The primary aim is to understand the manifold impacts of demographic, social, economic, infrastructural factors on response patterns to fire. Based on household surveys in 31 Jhuggi Jhonpdi clusters and resettlement colonies, we conducted multiple linear regression to understand the impact of predictors on response to fire. Our findings suggest that prior experience to fire has the strongest impact on household response to fire, followed by familiarity to place. The scope of the research lies in unfolding the nuanced dynamics of human actions during fire in the informal settlements, which otherwise, lie outside the purview of formal policy regulations.
Examining the Effects of Deep Learning Model Structure on Model Interpretability for Time-Series Classifications in Fire Research
Authors: Cheong Tam Wai , Fan Linhao , Tong Qi , Fang Hongqiang
Published: November 2024

This present work utilizes an interpretability model to understand and explain the decisions of deep learning models. The use of DeepLIFT is proposed and attributions of a study case are obtained. Benchmarking against two other interpretability models, namely Grad-CAM and dCAM, is conducted. Results show that DeepLIFT can provide precise attributions to the model inputs in both temporal and spatial directions. A parametric study is also carried out to understand the effects of deep learning model structure on the attributions obtained from the interpretability model. Ten different convolutional neural network model structures are considered. Three important observations are made: 1) changes in the model structure have minor effects on the attributions in the temporal direction, but 2) they have negligible effects on attributions in the spatial direction, and 3) convolutional layers need to be fixed to avoid attribution discrepancies. By understanding the model decision and the resulting effects of the model structure, it is hoped that this work can contribute to the development of trustworthy deep learning models for the fire research community.
Evaluating impacts of a LFP battery fire within a subsurface train compartment
Authors: Mamgain Alankrita , Restuccia Francesco
Published: November 2024

The application of lithium-ion batteries is becoming progressively prominent in everyday applications due to their high energy density, high output power and more favourable ageing characteristics in comparison to alternatives such as nickel metal hydride and lead acid batteries. However, when exposed to abuse conditions, lithium-ion batteries may undergo a thermal runaway reaction, resulting in high temperatures and release of flammable and toxic gases. This paper evaluates the temperature and smoke distribution to determine tenability period within a subsurface train compartment in the event of a lithium iron phosphate (LFP) battery fire. The results concluded that within 17 minutes of the failure of lithium iron phosphate batteries, the critical temperature of 60°C was exceeded in the entire carriage whilst the visibility threshold of 10m was exceeded in the carriage in under 86 seconds. Consequently, for an effective evacuation in this scenario, all passengers should be able to reach a place of relative safety before the critical limit for visibility is reached.
Predicting the total wall time of CFD simulations of single-compartment fires
Authors: Veit Martin , Lucherini Andrea , Maragkos Georgios , Merci Bart
Published: November 2024

The total wall time is often difficult to predict a priori in compartment fire simulations due to dynamic phenomena that can occur, e.g., flame extinction. The wall time is dependent on multiple physical factors in the simulation, along with simulation factors and the system used to compute the model. Specifically, the CFL number of a simulation is highly influential to the wall time, as this restricts the time step size. In this paper, the prediction of the total wall time for a single-compartment fire is investigated considering varying fire heat release rates and compartment ventilation factors. It is shown that an increasing heat release rate increases the total wall time due to higher velocities inside the compartment. Furthermore, when the compartment becomes under-ventilated, the wall time becomes more difficult to predict early on in the simulation, as steady state conditions are reached later, compared to well-ventilated cases. The time at which the wall time can be accurately predicted changed from a few physical seconds in the well-ventilated case, to up to 60 physical seconds for the under-ventilated case.
Application of machine learning techniques to predict fire development in an ISO 9705 room
Authors: Nasar Lareb , Dixon Harriet , Drosopoulos Georgios , Asimakopoulou Eleni
Published: November 2024

Machine learning, a subset of artificial intelligence, shows potential for enhancing computational fire modelling compared to traditional methods such as computational fluid dynamics. This study explored using artificial neural networks to predict heptane fire development within a compartment, varying heat release rates from 100 to 3000 kW and ventilation areas from 0.16 to 4.8 m2. Artificial neural networks (ANNs) were trained using computational data from an ISO 9705 room. Network optimisation involved adjusting training-to-validation ratios and fine-tuning hidden layer neuron counts. Results indicate optimised ANNs achieved less than 7% error for heat release rate predictions and 1.5% for ventilation size predictions, with a notable computational cost reduction exceeding 104-fold. These findings suggest a promising future for integrating machine learning into fire engineering, significantly reducing analysis time therefore fostering safety improvements and innovation in the field.
Exploration of Trends and Characteristics in Malaysian Building Fires and Wildfires (2000-2019)
Authors: Noumeur A , Tohir M Z M , Said M S M , Baharudin M R , Yusoff H M
Published: November 2024

Efforts to reduce fire casualties are crucial, and fire statistics are considered an important element that provides vital insights for assessing future risks. In line with Malaysia’s development, this study conducts a comprehensive analysis of the 9 fire indicators in Malaysia from 2000 to 2019 with the aim to explore fire incident patterns, including causes, fatalities, injuries, and associated losses. A notable escalation in fire breakouts and associated risks during this period were observed. Arson emerges as the leading cause of these incidents, closely followed by electricity and smoking-related fires. This analysis facilitates the deeper comprehension of fires trends in Malaysia and open the door for future comparison with other countries offering valuable insights for the fire department to forecast future fire scenarios.
High-Intensity Fast-Response Electric radiant Panel (HIFREP) for increased accuracy on thermal boundary conditions during fire testing
Authors: Put Florian , Jovanović Balša , Symoens Evelien , Lucherini Andrea , Merci Bart , Van Coile Ruben
Published: November 2024

Fire resistance tests rely on the use of standardized furnaces to apply specific thermal boundary conditions to assess the performance of construction materials and systems in fire conditions. However, these tests are very expensive and encounter challenges related to repeatability and uncertainties in establishing thermal boundary conditions. Moreover, their incapacitance to tailor experiments hinders advancements in understanding structural behaviour during fire exposure. In this work, a novel type of radiant panel, that operates on electricity, is introduced: the High-Intensity Fast-Response Electric radiant Panel (HIFREP). This innovation offers enhanced sustainability performance while ensuring more precise control over thermal boundary conditions. By eliminating the need for gas combustion, the panel can be used in a traditional structural testing lab to investigate non-combustible materials (e.g. concrete), without requiring extraction hoods and other provisions. The presented electric radiant panel system represents a significant step forward from fire resistance furnace testing.
Evaluation of GPU-based Conductive Heat Transfer Algorithms
Authors: Döhle Daniele , Börger Kristian , Arnold Lukas
Published: November 2024

The one-dimensional heat transfer algorithm of the Fire Dynamics Simulator (FDS) is currently implemented to run on a CPU (Central Processing Unit). This study explores the potential advantages of adapting the algorithm for Graphics Processing Units (GPUs), which could offer significant computational benefits.

The motivation behind this work stems from the intention to speed up numerical fire simulations. Up to now, simplifications with regard to grid resolution and level of detail have been made, compromising accuracy for quicker results. Simulations, especially for heat transfer in solid objects such as walls, require computationally intensive resources. By leveraging the GPUs’ superior parallel processing capabilities, it is possible to conduct faster and more accurate simulations, avoiding these compromises.

Both a CPU and a GPU algorithm for computing the 1D heat transfer are developed, and the computation time is compared against each other. Both implementations are validated against a simple FDS simulation with identical boundary conditions. The investigations show that the GPU algorithm is promising above a certain number of wall elements, depending on the employed hardware. The results show that this is generally the case from 2048 elements.
Generalized Ramsey Methods in Precision Laser Spectroscopy: from Atomic Clocks to Interferometers
Authors: Taichenachev A.V. , Yudin V.I.
Published: November 2024

This paper provides an overview of methods for suppressing probe-field-induced shifts in atomic clocks and interferometers using various generalized Ramsey schemes.
Universal nature of quantum supremacy
Authors: Kocharovsky Vitaly
Published: November 2024

We disclose the universal nature of computational #P-hardness and quantum supremacy of quantum many-body systems. We do so by means of the new powerful technique (the hafnian master theorem) that allows one to address the #P-hard problems systematically. We consider a generic example of many-body interacting systems – a trapped BEC-gas of interacting Bose atoms, apply the hafnian master theorem and refer to the Toda’s theorem on a #P-complete oracle.
Two-mode squeezing and entanglement in atomic boson sampling
Authors: Shannon William , Kocharovsky Vitaly
Published: November 2024

Recently, atomic boson sampling of excited atom occupations in an equilibrium interacting gas with a Bose-Einstein condensate (BEC) has been suggested as a process that could be #P-hard for classical computing. Here we consider this process within the simplest possible model of a BEC trap – the box with the periodic boundary conditions. Remarkably, this model remains pertained to #P-hardness and quantum supremacy. We evince two-mode squeezing and entanglement in the statistics of sampling from (i) a single eigen-squeeze mode or (ii) two counter-propagating waves. Although not complex enough on its own to show #P-hard behavior, such a sampling reveals the basic mechanism of the #P-hardness – an interplay between two intrinsic entities existing in the BEC gas, the eigen-energy quasiparticles and eigen-squeeze modes, that causes the interference and squeezing of the sampled excited atom states.
Linear and Angular Momentum of Classical Particles Interacting with a Laguerre-Gauss Laser Pulse
Authors: Toma Petru-Vlad , Băran Virgil , Micluta-Campeanu Sebastian , Boca Madalina
Published: November 2024

We investigate the evolution of an ensemble of classical charged particles interacting with a Laguerre-Gauss laser pulse. We integrate numerically the relativistic equations of motion for the particles which at the initial moment (before the arrival of the laser pulse) are at rest, distributed uniformly in a disk in the focal plane of the laser. We study the evolution in time of the linear and the angular momentum of the particles, and its dependence on the laser parameters (radial and azimuthal indices of the LG mode, waist, duration, and intensity) and also on the initial position of the particle in the focal plane. We show that in the low-intensity regime, the net transfer of linear momentum is parallel to the focal plane, while at large intensities the dominant component of the momentum is along the laser propagation direction. We also identify scaling laws obeyed by the net transfer of linear and angular momentum to the particles as a function of the field intensity. We present the relativistic ponderomotive force approximation model and study its validity for different parameters of the laser field. The scaling laws mentioned above are discussed also in the context of this approximation.
Ultrabroad Band Collinear Mid-Infrared Optical Parametric Amplifier Driven by a Millijoule Femtosecond Tm:YAP Regenerative Amplifier
Authors: Fuji T , Rezvani S A
Published: November 2024

We present a comprehensive study on the development and performance of an ultra-broadband mid-infrared (MIR) optical parametric amplifier (OPA) pumped by a home-built solid-state amplification system. The intricate design encompasses a thulium-doped fluoride (Tm:ZBLAN) fiber oscillator, a two-stage Tm:ZBLAN fiber preamplifier, and a regenerative amplifier featuring a thermoelectrically cooled thulium-doped yttrium aluminium perovskite crystal (Tm:YAP). The amplifier yields 265 fs 1 mJ pulses at 1940 nm. A portion of the pulse is directed into a polarization-maintaining ZBLAN fiber, generating a multi-octave MIR supercontinuum through self-phase modulation process. This supercontinuum is then collinearly combined with the regenerative amplifier’s output pulse and further amplified within a 1-mm thick gallium selenide crystal through an optical parametric process. The resulting spectra of the signal pulse and the idler pulse span from 2.5 to 4 µm and from 4 to 9 µm, respectively. The combined power of the signal and idler waves reaches 10 mW, with an overall efficiency of 4%. Remarkably, the transform-limited pulse durations for the signal and idler are 22 fs and 17 fs, respectively. This work underscores the successful realization of an advanced collinear MIR OPA system, offering unprecedented capabilities in terms of spectral coverage.