José Manuel Díaz-Rasero, B. Ledesma, María Alonso, Silvia Román
This study investigated the fuel potential and combustion behavior of hydrochars derived from a unique precursor: Carthamus pomace. Initially, the hydrothermal carbonization process of this novel feedstock was examined across various temperature ranges (180–240 °C) and durations (15–180 min). The impact of these processing conditions was analyzed in terms of degradation mechanisms and their correlation with the resulting properties of the hydrochars (HCs) produced. Then, the combustion performance of these materials was studied by means of thermogravimetry, and the differences in reactivity and activation energy were analyzed and associated with preparation processes. Finally, the most promising HTC parameters were identified and a thermoeconomic study on the use of selected HCs on a thermal plant devoted to the production of electricity was evaluated including energy savings associated with the implementation of heat exchangers using the heat of the flue gases to partially supply the energy needs associated with HTC.
{"title":"Upgrading Carthamus by HTC: Improvement of Combustion Properties","authors":"José Manuel Díaz-Rasero, B. Ledesma, María Alonso, Silvia Román","doi":"10.3390/fire7040106","DOIUrl":"https://doi.org/10.3390/fire7040106","url":null,"abstract":"This study investigated the fuel potential and combustion behavior of hydrochars derived from a unique precursor: Carthamus pomace. Initially, the hydrothermal carbonization process of this novel feedstock was examined across various temperature ranges (180–240 °C) and durations (15–180 min). The impact of these processing conditions was analyzed in terms of degradation mechanisms and their correlation with the resulting properties of the hydrochars (HCs) produced. Then, the combustion performance of these materials was studied by means of thermogravimetry, and the differences in reactivity and activation energy were analyzed and associated with preparation processes. Finally, the most promising HTC parameters were identified and a thermoeconomic study on the use of selected HCs on a thermal plant devoted to the production of electricity was evaluated including energy savings associated with the implementation of heat exchangers using the heat of the flue gases to partially supply the energy needs associated with HTC.","PeriodicalId":12279,"journal":{"name":"Fire","volume":"111 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140386973","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The effectiveness of fireproof sealing systems in preventing the spread of fire in high-rise building cable shafts relies on the properties of various sealing materials and the construction process. Therefore, a comprehensive evaluation is necessary. The authors of this paper propose a comparative test method based on an entity test platform for a performance evaluation of cable shaft fireproof sealing systems in high-rise buildings. The test platform measures changes in temperature, humidity, and smoke mass during fire tests to compare the performance of four sets of fireproof sealing systems in terms of thermal insulation, smoke sealing capacity, and overall integrity. In addition, a fire dynamics simulation (FDS) of fireproof sealing systems was carried out on the entity test platform, and the sealing failure process in the case of cracking in the fireproof sealing system was revealed. The simulation results for the temperature trends in the lower space align with the fire test results. Furthermore, as the gap size increases, the diffusion of smoke and flame accelerates. Consequently, the performance of cable shaft fireproof sealing systems depends not only on the sealing material but also on the construction process.
{"title":"Performance Evaluation of Cable Shaft Fireproof Sealing System in High-Rise Buildings: A Comparative Test Method","authors":"Bizhen Zhang, Shengwen Shu, Zhicong Zheng, Bo Qu, Xin Li, Xingyao Xiang, Shuai Xia","doi":"10.3390/fire7030102","DOIUrl":"https://doi.org/10.3390/fire7030102","url":null,"abstract":"The effectiveness of fireproof sealing systems in preventing the spread of fire in high-rise building cable shafts relies on the properties of various sealing materials and the construction process. Therefore, a comprehensive evaluation is necessary. The authors of this paper propose a comparative test method based on an entity test platform for a performance evaluation of cable shaft fireproof sealing systems in high-rise buildings. The test platform measures changes in temperature, humidity, and smoke mass during fire tests to compare the performance of four sets of fireproof sealing systems in terms of thermal insulation, smoke sealing capacity, and overall integrity. In addition, a fire dynamics simulation (FDS) of fireproof sealing systems was carried out on the entity test platform, and the sealing failure process in the case of cracking in the fireproof sealing system was revealed. The simulation results for the temperature trends in the lower space align with the fire test results. Furthermore, as the gap size increases, the diffusion of smoke and flame accelerates. Consequently, the performance of cable shaft fireproof sealing systems depends not only on the sealing material but also on the construction process.","PeriodicalId":12279,"journal":{"name":"Fire","volume":"136 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140222981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hongpeng Qiu, Xuanwen Liang, Qian Chen, Eric W.M. Lee
The cellular automata (CA) model has been a meaningful way to study pedestrian evacuation during emergencies, such as fires, for many years. Although the time step used in the CA model is one of the most essential elements, there is a lack of research on its impact on evacuation time. In this paper, we set different time step sizes in an extended cellular automaton model and discuss the effect of time step size on the overall evacuation time under different emergency types and levels. For a fixed step time mode, the larger the time step, the longer the evacuation time. In each time step size, the evacuation time gradually increases with the increase of emergency level, and there is a sharp increase when the time for pedestrians to move one step is exactly an integer multiple of the time step. When there is no friction between pedestrians, the evacuation time at each time step first decreases slightly with the increase of emergency level and then remains unchanged; the larger the time step, when the evacuation time remains unchanged, the lower the emergency level and the greater the evacuation time. For the variable time step model, when the friction between pedestrians approaches infinity, the total evacuation time does not change with the emergency level; when the friction between pedestrians is reduced, the total evacuation time slightly decreases with the increase of the emergency level. The less friction there is, the more significant the reduction. The results of previous actual experiments are also reflected in the simulation at a lower emergency level. The result shows that the time step size significantly impacts the evacuation simulation results of the CA model, and researchers should choose carefully to obtain more realistic simulation results.
多年来，细胞自动机（CA）模型一直是研究火灾等紧急情况下行人疏散的有效方法。虽然 CA 模型中使用的时间步长是最基本的要素之一，但目前还缺乏关于时间步长对疏散时间影响的研究。本文在扩展的蜂窝自动机模型中设置了不同的时间步长，并讨论了在不同紧急情况类型和级别下，时间步长对整体疏散时间的影响。在固定步长时间模式下，时间步长越大，疏散时间越长。在每种时间步长下，疏散时间随着紧急情况级别的增加而逐渐增加，当行人移动一步的时间正好是时间步长的整数倍时，疏散时间会急剧增加。当行人之间没有摩擦时，每个时间步长的疏散时间先是随着紧急程度的增加而略有减少，然后保持不变；当疏散时间保持不变时，时间步长越大，紧急程度越低，疏散时间越长。对于可变时间步长模型，当行人之间的摩擦力接近无穷大时，总疏散时间不随紧急程度的变化而变化；当行人之间的摩擦力减小时，总疏散时间随紧急程度的增加而略有减少。摩擦力越小，缩短的时间越明显。之前的实际实验结果也反映在较低紧急程度下的模拟中。结果表明，时间步长对 CA 模型的疏散模拟结果有很大影响，研究人员应谨慎选择，以获得更真实的模拟结果。
{"title":"Effect of Different Time Step Sizes on Pedestrian Evacuation Time under Emergencies Such as Fires Using an Extended Cellular Automata Model","authors":"Hongpeng Qiu, Xuanwen Liang, Qian Chen, Eric W.M. Lee","doi":"10.3390/fire7030100","DOIUrl":"https://doi.org/10.3390/fire7030100","url":null,"abstract":"The cellular automata (CA) model has been a meaningful way to study pedestrian evacuation during emergencies, such as fires, for many years. Although the time step used in the CA model is one of the most essential elements, there is a lack of research on its impact on evacuation time. In this paper, we set different time step sizes in an extended cellular automaton model and discuss the effect of time step size on the overall evacuation time under different emergency types and levels. For a fixed step time mode, the larger the time step, the longer the evacuation time. In each time step size, the evacuation time gradually increases with the increase of emergency level, and there is a sharp increase when the time for pedestrians to move one step is exactly an integer multiple of the time step. When there is no friction between pedestrians, the evacuation time at each time step first decreases slightly with the increase of emergency level and then remains unchanged; the larger the time step, when the evacuation time remains unchanged, the lower the emergency level and the greater the evacuation time. For the variable time step model, when the friction between pedestrians approaches infinity, the total evacuation time does not change with the emergency level; when the friction between pedestrians is reduced, the total evacuation time slightly decreases with the increase of the emergency level. The less friction there is, the more significant the reduction. The results of previous actual experiments are also reflected in the simulation at a lower emergency level. The result shows that the time step size significantly impacts the evacuation simulation results of the CA model, and researchers should choose carefully to obtain more realistic simulation results.","PeriodicalId":12279,"journal":{"name":"Fire","volume":"175 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140222626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nuclear power fire protection is an important part of nuclear safety, and strengthening fire protection technology research is essential for improving nuclear safety and fire protection. The operating platform inside a containment structure is one important element in fire risk evaluation in nuclear power plants. In this paper, a combustible nuclear-grade cable in a fire scenario was firstly selected as the research object, and then the nuclear-grade cable was separately subjected to a combustion test as well as a thermogravimetric test in order to obtain the relevant thermal parameters, which provide more accurate data support for the establishment of a cable fire development and spread model. The nuclear-grade cable material data obtained from the test were compared with a civil PVC cable in order to conduct a specific analysis of the fire risk of nuclear-grade cables. This study shows that the effects of different heating rates and heating atmospheres on the thermal decomposition behavior of cable materials are meaningful and helpful in understanding whether the materials will undergo combustion processes at high temperatures and whether fire spread will occur.
{"title":"An Experimental Analysis of a Nuclear-Grade Cable Based on Fire Combustion Characteristics and Pyrolysis Behavior","authors":"Qiang Shi, Jiaxu Zuo, Wei Song, Fang Jing","doi":"10.3390/fire7030101","DOIUrl":"https://doi.org/10.3390/fire7030101","url":null,"abstract":"Nuclear power fire protection is an important part of nuclear safety, and strengthening fire protection technology research is essential for improving nuclear safety and fire protection. The operating platform inside a containment structure is one important element in fire risk evaluation in nuclear power plants. In this paper, a combustible nuclear-grade cable in a fire scenario was firstly selected as the research object, and then the nuclear-grade cable was separately subjected to a combustion test as well as a thermogravimetric test in order to obtain the relevant thermal parameters, which provide more accurate data support for the establishment of a cable fire development and spread model. The nuclear-grade cable material data obtained from the test were compared with a civil PVC cable in order to conduct a specific analysis of the fire risk of nuclear-grade cables. This study shows that the effects of different heating rates and heating atmospheres on the thermal decomposition behavior of cable materials are meaningful and helpful in understanding whether the materials will undergo combustion processes at high temperatures and whether fire spread will occur.","PeriodicalId":12279,"journal":{"name":"Fire","volume":"84 s371","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140223459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Relative to conventional coal pillar retention mining technology (the 121 mining method), gob-side entry retaining by cutting roof (the 110 mining method), a non-pillar mining technique, efficiently addresses issues like poor coal resource recovery and significant rock burst damage. Nonetheless, the open-type goaf created by 110 mining techniques suffers from complex and significant air leaks, increasing the likelihood of coal spontaneous combustion (CSC) within the gob area. To address the CSC problem caused by complex air leakage within the goaf of gob-side entry retaining by roof cutting, this study takes the 17202 working face of Dongrong Second Coal Mine as the object of study. Field tests and simulation calculations are conducted to research the features of air leakage and the distribution of the oxidation zone within the goaf. Subsequently, plugging technology with varying plugging lengths is proposed and implemented. The tests and simulations reveal that the airflow migration within the goaf follows an L-shaped pattern, while air leakage primarily originates from gaps found in the gob-side entry retaining wall. The amount of air leaking into the gob-side entry retaining section is 171.59 m3/min, which represents 7.3% of the overall airflow. The maximum oxidation zone within the goaf ranges from 58.7 m to 151.8 m. After the air leakage is blocked, the airflow migration route within the goaf is transformed into a U-shaped distribution, and the maximum oxidation zone range changes from 42.8 m to 80.7 m. Engineering practice demonstrates that after air leakage plugging, the total air leakage volume within the gob-side entry retaining section significantly reduces to 20.59 m3/min, representing only 0.78% of the total airflow volume. This research provides reference on how to prevent the occurrence of CSC in similar mine goafs.
{"title":"Mitigating Coal Spontaneous Combustion Risk within Goaf of Gob-Side Entry Retaining by Roof Cutting: Investigation of Air Leakage Characteristics and Effective Plugging Techniques","authors":"Zhipeng Zhang, Xiaokun Chen, Zhijin Yu, Hao Sun, Dewei Huang, Jiangle Wu, Hao Zhang","doi":"10.3390/fire7030098","DOIUrl":"https://doi.org/10.3390/fire7030098","url":null,"abstract":"Relative to conventional coal pillar retention mining technology (the 121 mining method), gob-side entry retaining by cutting roof (the 110 mining method), a non-pillar mining technique, efficiently addresses issues like poor coal resource recovery and significant rock burst damage. Nonetheless, the open-type goaf created by 110 mining techniques suffers from complex and significant air leaks, increasing the likelihood of coal spontaneous combustion (CSC) within the gob area. To address the CSC problem caused by complex air leakage within the goaf of gob-side entry retaining by roof cutting, this study takes the 17202 working face of Dongrong Second Coal Mine as the object of study. Field tests and simulation calculations are conducted to research the features of air leakage and the distribution of the oxidation zone within the goaf. Subsequently, plugging technology with varying plugging lengths is proposed and implemented. The tests and simulations reveal that the airflow migration within the goaf follows an L-shaped pattern, while air leakage primarily originates from gaps found in the gob-side entry retaining wall. The amount of air leaking into the gob-side entry retaining section is 171.59 m3/min, which represents 7.3% of the overall airflow. The maximum oxidation zone within the goaf ranges from 58.7 m to 151.8 m. After the air leakage is blocked, the airflow migration route within the goaf is transformed into a U-shaped distribution, and the maximum oxidation zone range changes from 42.8 m to 80.7 m. Engineering practice demonstrates that after air leakage plugging, the total air leakage volume within the gob-side entry retaining section significantly reduces to 20.59 m3/min, representing only 0.78% of the total airflow volume. This research provides reference on how to prevent the occurrence of CSC in similar mine goafs.","PeriodicalId":12279,"journal":{"name":"Fire","volume":"29 13","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140226408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kinga Łysień, Tomasz Jarosz, Karolina Głosz, A. Stolarczyk
Identification of the mechanism of changes taking place in energetic materials (EMs) is one of the most important issues in the rational design and use of EMs. Due to the extremely rapid nature of these changes, reliable monitoring and real-time analysis are extremely difficult. Hence, analysis of the mechanism of such processes often has to rely on adaptation of classical methods or on comparison of the initial and final states of the EM. In this critical review, we focus on current approaches to the methodology of investigating the mechanisms of processes taking place in EMs, showcasing viable experimental strategies, points of uncertainty, and adaptations of classical instrumental methods.
{"title":"Elucidating the Mechanisms of Reactions in Energetic Materials: A Critical Methodology Review","authors":"Kinga Łysień, Tomasz Jarosz, Karolina Głosz, A. Stolarczyk","doi":"10.3390/fire7030099","DOIUrl":"https://doi.org/10.3390/fire7030099","url":null,"abstract":"Identification of the mechanism of changes taking place in energetic materials (EMs) is one of the most important issues in the rational design and use of EMs. Due to the extremely rapid nature of these changes, reliable monitoring and real-time analysis are extremely difficult. Hence, analysis of the mechanism of such processes often has to rely on adaptation of classical methods or on comparison of the initial and final states of the EM. In this critical review, we focus on current approaches to the methodology of investigating the mechanisms of processes taking place in EMs, showcasing viable experimental strategies, points of uncertainty, and adaptations of classical instrumental methods.","PeriodicalId":12279,"journal":{"name":"Fire","volume":"14 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140226431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thuy Tien Nguyen Thanh, Ziya Yusifov, Bence Tóth, K. Bocz, Péter Márton, Zoltán Hórvölgyi, György Marosi, B. Szolnoki
Polypropylene (PP) shows no charring ability in burning due to the lack of hydroxyl functional groups; thus, the flame retardant system needs an additional amount of carbonizing agent. An ammonium polyphosphate (APP)-based all-in-one intumescent flame-retardant system was prepared by the in situ polymerization of polymeric methylene diphenyl diisocyanate (pMDI) with a glycerol-based and a glycerol–sorbitol-based polyol of high OH value. The microencapsulated APP with a polyurethane shell (MCAPP) of different polyols was characterized. The MCAPP with speculated improved flame retardant performance was selected for further evaluation in the PP matrix at different loadings by means of standard flammability tests.
{"title":"Preparation and Characterization of Microencapsulated Ammonium Polyphosphate with Polyurethane Shell and Its Flame Retardance in Polypropylene","authors":"Thuy Tien Nguyen Thanh, Ziya Yusifov, Bence Tóth, K. Bocz, Péter Márton, Zoltán Hórvölgyi, György Marosi, B. Szolnoki","doi":"10.3390/fire7030097","DOIUrl":"https://doi.org/10.3390/fire7030097","url":null,"abstract":"Polypropylene (PP) shows no charring ability in burning due to the lack of hydroxyl functional groups; thus, the flame retardant system needs an additional amount of carbonizing agent. An ammonium polyphosphate (APP)-based all-in-one intumescent flame-retardant system was prepared by the in situ polymerization of polymeric methylene diphenyl diisocyanate (pMDI) with a glycerol-based and a glycerol–sorbitol-based polyol of high OH value. The microencapsulated APP with a polyurethane shell (MCAPP) of different polyols was characterized. The MCAPP with speculated improved flame retardant performance was selected for further evaluation in the PP matrix at different loadings by means of standard flammability tests.","PeriodicalId":12279,"journal":{"name":"Fire","volume":"64 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140230114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Klink, S. Lednev, I. Semenkov, M. Konyushkova, A. Karpachevskiy, M. M. Chemidov, Svetlana S. Ulanova, Natal’ya L. Fedorova, A. Sharapova, Sergey A. Bogun, Tatyana V. Koroleva
Understanding the rate and direction of pyrogenic succession in arid ecosystems, which depends on many factors, including the intensity of grazing and the frequency of pyrogenic expo-sure, will allow for more accurate predictions of the consequences of fire onplant communities, and will assist with better fire management. We studied the vegetation on 55 sites in and near the “Chernye Zemli” Natural Biosphere Reserve that burned at different times or were not affected by fires over the past 35 years and characterized the changes in vegetation cover associated with the impact of wildfire and grazing. The descriptions were grouped into chronological stages according to the time elapsed since the last fire, or into groups according to the frequency of fires. In pairwise comparison of the projective cover of plant species between chronological stages, it correlated most strongly between successive initial stages (for stages 1 and 2, p = 0.003, r = 0.73; for stages 2 and 3, p < 0.001, r = 0.78). Species with an initially higher projective cover were more likely to grow on plots in the first year after the fire: p < 0.03. Plots with rare and frequent fires had similar projective cover of individual species (r = 0.64, p < 0.001). We conclude that in the course of pyrogenic succession, communities are gradually replaced over at least ten years. At the same time, the composition of a plant community at the initial point of succession depends on the prevalence of species in the community before the fire. No fundamental effect of the frequency of fires on the composition of plant communities has been revealed.
{"title":"Influence of Fires on Desert Plant Communities at the Chernye Zemli (SW Russia)","authors":"G. Klink, S. Lednev, I. Semenkov, M. Konyushkova, A. Karpachevskiy, M. M. Chemidov, Svetlana S. Ulanova, Natal’ya L. Fedorova, A. Sharapova, Sergey A. Bogun, Tatyana V. Koroleva","doi":"10.3390/fire7030096","DOIUrl":"https://doi.org/10.3390/fire7030096","url":null,"abstract":"Understanding the rate and direction of pyrogenic succession in arid ecosystems, which depends on many factors, including the intensity of grazing and the frequency of pyrogenic expo-sure, will allow for more accurate predictions of the consequences of fire onplant communities, and will assist with better fire management. We studied the vegetation on 55 sites in and near the “Chernye Zemli” Natural Biosphere Reserve that burned at different times or were not affected by fires over the past 35 years and characterized the changes in vegetation cover associated with the impact of wildfire and grazing. The descriptions were grouped into chronological stages according to the time elapsed since the last fire, or into groups according to the frequency of fires. In pairwise comparison of the projective cover of plant species between chronological stages, it correlated most strongly between successive initial stages (for stages 1 and 2, p = 0.003, r = 0.73; for stages 2 and 3, p < 0.001, r = 0.78). Species with an initially higher projective cover were more likely to grow on plots in the first year after the fire: p < 0.03. Plots with rare and frequent fires had similar projective cover of individual species (r = 0.64, p < 0.001). We conclude that in the course of pyrogenic succession, communities are gradually replaced over at least ten years. At the same time, the composition of a plant community at the initial point of succession depends on the prevalence of species in the community before the fire. No fundamental effect of the frequency of fires on the composition of plant communities has been revealed.","PeriodicalId":12279,"journal":{"name":"Fire","volume":"71 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140235000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to study the effect of hydrated phase change materials on the suppression of spontaneous combustion in coal, a thermogravimetric experiment and a reaction activation energy analysis experiment were conducted to explore the changes in the combustion characteristic parameters, characteristic temperature, and activating energy of gas coal, long-flame coal, meagre coal, and lean coal before and after adding hydrated phase change materials. The research results indicated that hydrated phase change materials increased the characteristic temperature point of the coal samples and had effective inhibitory effects on different stages of the oxidation process. However, the effect was best at low temperatures, as hydrated phase change materials undergo phase change and absorb heat when heated at low temperatures, isolating coal from contact with oxygen. The activating energy increased by 1.138–23.048 KJ·mol−1 and the mass loss was reduced by 1.6%–9.3% after inhibition of the coal samples, indicating that the oxidation rate of the various coal samples was slowed down and, thus, spontaneous combustion can be suppressed through the use of hydrated phase change materials. At the same time, this material reduced the combustibility indices of meagre coal and lean coal, as well as the comprehensive combustion indices of long-flame coal and gas coal.
{"title":"Research on the Inhibitory Effect of Hydrated Phase Change Materials on Spontaneous Combustion in Coal","authors":"Fanghua Wu, Shiliang Shi, Shuzhen Shao, Yi Lu, Wangxin Gu, Youliang Wang, Xindi Yuan","doi":"10.3390/fire7030095","DOIUrl":"https://doi.org/10.3390/fire7030095","url":null,"abstract":"In order to study the effect of hydrated phase change materials on the suppression of spontaneous combustion in coal, a thermogravimetric experiment and a reaction activation energy analysis experiment were conducted to explore the changes in the combustion characteristic parameters, characteristic temperature, and activating energy of gas coal, long-flame coal, meagre coal, and lean coal before and after adding hydrated phase change materials. The research results indicated that hydrated phase change materials increased the characteristic temperature point of the coal samples and had effective inhibitory effects on different stages of the oxidation process. However, the effect was best at low temperatures, as hydrated phase change materials undergo phase change and absorb heat when heated at low temperatures, isolating coal from contact with oxygen. The activating energy increased by 1.138–23.048 KJ·mol−1 and the mass loss was reduced by 1.6%–9.3% after inhibition of the coal samples, indicating that the oxidation rate of the various coal samples was slowed down and, thus, spontaneous combustion can be suppressed through the use of hydrated phase change materials. At the same time, this material reduced the combustibility indices of meagre coal and lean coal, as well as the comprehensive combustion indices of long-flame coal and gas coal.","PeriodicalId":12279,"journal":{"name":"Fire","volume":"13 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140235237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abigail R. Croker, Adriana E. S. Ford, Y. Kountouris, Jay Mistry, Amos Chege Muthiuru, Cathy Smith, Elijah Praise, David O. Chiawo, Veronica Muniu
In many landscapes worldwide, fire regimes and human–fire interactions were reorganised by colonialism and continue to be shaped by neo-colonial processes. The introduction of fire suppression policies and state-centric property-rights systems across conservation areas and the intentional erasure of Indigenous governance systems and knowledge have served to decouple Indigenous fire-dependent communities from culturally mediated fire regimes and fire-adapted landscapes. This has driven a decline in anthropogenic fires while simultaneously increasing wildfire risk where Indigenous people have been excluded, resulting in widespread social–ecological vulnerabilities. Much contemporary fire research also bears colonial legacies in its epistemological traditions, in the global geographical distribution of research institutions, and the accessibility of research outputs. We report on a two-day workshop titled ‘Fire Management Across Contested Landscapes’ convened concurrently in Nairobi, Kenya, and London, UK. The workshop formed part of a series of workshops on ‘Decolonising Fire Science’ held by the Leverhulme Centre for Wildfires, Environment and Society, UK. The workshop in Nairobi invited diverse Kenyan stakeholders to engage in participatory activities that facilitate knowledge sharing, aiming to establish an inclusive working fire network. Activities included rich pictures, world café discussions, participatory art, and the co-development of a declaration to guide fire management in Kenya. Meanwhile, in London, Leverhulme Wildfires researchers explored participatory research methodologies including rich pictures and participatory video, and developed a declaration to guide more equitable research. There were opportunities throughout the workshop for participants in Nairobi and London to engage in dialogue with one another, sharing their experiences and understandings of complex fire challenges in Kenya and globally.
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