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Study on smoke propagation in tunnel construction of a hydropower station: A full-scale fire experiment

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Journal of Safety Science and Resilience 2023年第2期4卷 188-202页

作者： Chang Liu Huihang Cheng Wenjun Nie Senlin Jiang Junfeng Chen Peng Lin Maohua Zhong Institute of Public Safety Research Departnent of Engineering PhysicsTsinghua UniverstyBeijing 100084China China Electric Power Research Institute Beijing 100192China Sinohydro Bureau 6 Co. LTDShenyang 110179China Department of Hydraulic Engineering Tsinghua UniversityBeijing 100084China

In this study,full-scale fire experiments were conducted in a hydropower station to investigate smoke propagation during tunnel construction.The flame height,smoke temperature and stratification,smoke descent and spread velocity were analyzed via measurements and on-site observations.The initial combustion stage was largely affected by ignition source during tunnel construction for diesel pool fire,and the average flame height in the fully developed stage could reach 1.4-2.1 m in experimental fire scenarios.The gradient of the smoke temperature evolution near the fire was the opposite for the upstream and downstream regions.The longitudinal temperature distribution was concentrated in a small range at the heights of the smoke layer,and gradually decreased by air entrainment as the height decreased,while further increasing in the lower half of the tunnel height in the near-fire region under heat radiation from the fire source.Moreover,distinct and stable smoke stratification formed during the fully developed combustion stage,and the smoke layer interface was at approximately half the tunnel height.Smoke descent was aggravated in the decay stage of combustion,and the fire risk remained high after the fully developed period.The smoke front spread velocity was empirically determined for the full-scale tunnel fire scenarios.Conclusions from full-scale experiments can support smoke control design and on-site fire emergency response plans for hydropower stations.

关键词： Full-scale experiment fire Smoke propagation Construction tunnel Hydropowerstation

Toxicity and horizontal transfer of bifenthrin and dimefluthrin against the red imported fire ant, Solenopsis invicta Buren(Hymenoptera: Formicidae), and the efficacy of their dust applications in the field

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Journal of Integrative Agriculture 2023年第5期22卷 1465-1476页

作者： LIANG Ming-rong SHUANG You-ming DENG Jie-fu PENG Li-ya ZHANG Sen-quan ZHANG Chen XU Yi-juan LU Yong-yue WANG Lei Red Imported fire Ant Research Center South China Agricultural UniversityGuangzhou 510642P.R.China Shenzhen Agricultural Science and Technology Promotion Center Shenzhen Administration for Market RegulationShenzhen 518057P.R.China

The red imported fire ant,Solenopsis invicta Buren,poses a significant threat to biodiversity,agriculture,and public health in its introduced ranges.While chemicals such as toxic baits and dust are the main methods for S.invicta control,toxic baits are slow,requiring approximately one or two weeks,but dust can eliminate the colony of fire ants rapidly in just three to five days.To explore more active ingredients for fire ant control using dusts,the toxicity of bifenthrin and dimefluthrin,the horizontal transfer of bifenthrin and dimefluthrin dust and their efficacy in the field were tested.The results showed that the LD50(lethal dose) values of bifenthrin and dimefluthrin were 3.40 and 1.57 ng/ant,respectively.The KT50(median knockdown time) and KT95(95%knockdown time) values of a 20μg mL^(–1)bifenthrin dose were 7.179and 16.611 min,respectively.The KT50and KT95of a 5μg mL^(–1)dimefluthrin dose were 1.538 and 2.825 min,respectively.The horizontal transfers of bifenthrin and dimefluthrin among workers were effective.The mortality of recipients (secondary mortality) and secondary recipients (tertiary mortality) were both over 80%at 48 h after 0.25,0.50 and 1.00%bifenthrin dust treatments.The secondary mortality of recipients was over 99%at 48 h after 0.25,0.50 and 1.00% dimefluthrin dust treatments,but the tertiary mortality was below 20%.The field trial results showed that both bifenthrin and dimefluthrin exhibited excellent fire ant control effects,and the comprehensive control effects of 1.00%bifenthrin and dimefluthrin dusts at 14 d post-treatment were 95.87 and 85.70%,respectively.

关键词： red imported fire ant pyrethroids secondary transfer tertiary mortality contact toxic dust

fire behaviour of multiple fires in a mine drift with longitudinal ventilation

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International Journal of Mining Science and Technology 2019年第2期29卷 245-254页

作者： Rickard Hansen Sustainable Minerals Institute The University of Queensland

The fire behaviour involving multiple fires in a mine drift with longitudinal ventilation was analysed. The conditions and fire phenomena occurring were described. The analysis was based upon experimental data from model-scale fire experiments. A fire involving several fuel items may lead to flames tilted horizontally and filling up the entire cross section, leading to earlier ignition, higher fire growth rates, higher fire spread rate and severe fire behaviour. Longer flame lengths will also result due to decreased air entrainment. A correlation for the continuous flame length was proposed. The results of the analysis will help identifying and preventing potentially dangerous fire situations with several large combustible items distributed along a mine drift.

关键词： Multiple fires Mine drift fire spread Flame length fire growth

fire sensitivity of broadleaf tree species in plantations of Kurdistan,Iran

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Journal of Forestry Research 2021年第3期32卷 1167-1176页

作者： Sabri Baqer Rasooli Shiva Rashidi Naghi Shabanian Department of Geography College of EducationUniversity of GarmianKalarKurdistan RegionIraq Department of Forestry Faculty of Natural ResourcesUniversity of KurdistanSanandajIran

To better manage wildfires and plantations in Kurdistan,native tree species commonly used in planting and reviving forests such as Quercus brantii Lindl.,Q.infectoria Olivier,Q.libani Olivier,Pistachio atlantica Desf.,Fraxinus rotundifolia Vahl,and Robinia pseudoacacia L.were evaluated and compared in terms of fire sensitivity and fire resistance.To determine fire sensitivity,indices such as the fl ammability index,ignition time,fl ame durability,moisture content,carbonized surface,mass reduction,bulk density,as well as dry weight of wood,bark,and leaves were used.The data were subjected to ANOVA.The means obtained,after examining homogeneity or heterogeneity of the variances,were compared using parametric and nonparametric comparison tests.There was a significant difference at the level of 5%.Based on the analysis of these indices,the species could be divided into three groups:species sensitive to fire such as Robinia pseudoacacia,species moderately sensitive to fire such as F.rotundifolia,and species relatively resistant to fire,including Q.brantii,Q.libani,Q.infectoria,and P.atlantica.

关键词： fire Flammability index Time to ignition Flame durability Moisture content

fire blight disease, a fast-approaching threat to apple and pear production in China

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Journal of Integrative Agriculture 2019年第4期18卷 815-820页

作者： ZHAO Yu-qiang TIAN Yan-li WANG Li-min GENG Guo-min ZHAO Wen-jun HU Bai-shi ZHAO You-fu Jiangsu Key Laboratory for the Research and Utilization of Plant Resources Institute of Botany Jiangsu Province and Chinese Academy of Sciences (Nanjing Botanical Garden Mem. Sun Yat-Sen) College of Plant Protection Nanjing Agricultural University/Key Laboratory of Integrated Management of Crop Diseases and Pests Ministry of Education Chinese Academy of Inspection and Quarantine Department of Crop Sciences University of Illinois at Urbana-Champaign

fire blight, caused by Erwinia amylovora, is a devastating disease of apples and pears, causing enormous economic losses around the world. The disease is indigenous to North America and has spread to more than 50 countries since its discovery in 1870 s. Recent reports of the disease in China's neighboring countries, including South Korea, Kyrgyzstan, and Kazakhstan, pose great threat to the world's leading producer of apples and pears. This mini-review intends to provide an update on the disease, pathogen biology, epidemiology, and control. It will also provide some perspectives and suggestions for the apple and pear industry and growers in China, which will face the imminent threat of this devastating disease.

关键词： fire blight Erwinia amylovora biology epidemiology disease control

Efficacy of a Community-Based Trauma Recovery Program after a fire Disaster

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International Journal of Mental Health Promotion 2022年第1期24卷 85-94页

作者： Yun-Jung Choi Mi-Ra Won Dong-Hee Cho Red Cross College of Nursing Chung-Ang UniversitySeoulKorea Department of Nursing Daewon University CollegeJecheonKorea

As industries develop,fire disasters and their associated damage are increasing.Investigating the mental health of victims is imperative because this is an essential issue for community recovery after a disaster.This study was conducted to determine the efficacy of a program implemented by a community mental health center based on the investigation of the victims’depression and post-traumatic stress disorder(PTSD)levels immediately after the disaster and at one-year follow-up.As a result,victims’depression and PTSD recovered over time,and more changes were confirmed.In particular,the high-risk group for PTSD showed a high program participation rate,and there was significant recovery over time compared with the group without PTSD.Based on these results,community mental health programs are an effective way to increase community mental health after disasters.In the future,community-based recovery programs after disasters should be expanded,and administrative support for them should be developed.

关键词： fire disaster victims post-traumatic stress disorder depression community mental health services

An innovative model for predicting the displacement and rotation of column-tree moment connection under fire

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Frontiers of Structural and Civil Engineering 2021年第1期15卷 194-212页

作者： Mohammad Ali NAGHSH Aydin SHISHEGARAN Behnam KARAMI Timon RABCZUK Arshia SHISHEGARAN Hamed TAGHAVIZADEH Mehdi MORADI Department of Civil Engineering Isfahan University of TechnologyIsfahan 84156-83111Iran School of Civil Engineering School of Civil EngineeringIran University of Science and TechnologyTehran 13114-16846Iran Department of Civil Engineering International Institute of Earthquake Engineering and SeismologyTehran 19539-14453Iran Division of Computational Mechanics Ton Duc Thang UniversityHo Chi Minh CityVietnam Faculty of Civil Engineering Ton Duc Thang UniversityHo Chi Minh CityVietnam Department of Civil Engineering Islamic Azad UniversityTehran 16511-53311Iran Department of Civil Engineering Isfahan UniversityIsfahan 81746-73441Iran

In this study,we carried out nonlinear finite element simulations to predict the performance of a columntree moment connection(CTMC)under fire and static loads.We also conducted a detailed parameter study based on five input variables,including the applied temperature,number of flange bolts,number of web bolts,length of the beam,and applied static loads.The first variable is changed among seven levels,whereas the other variables are changed among three levels.Employing the Taguchi method for variables 2-5 and their levels,9 samples were designed for the parameter study,where each sample was exposed to 7 different temperatures yielding 63 outputs.The related variables for each output are imported for the training and testing of different surrogate models.These surrogate models include a multiple linear regression(MLR),multiple Ln equation regression(MLnER),an adaptive network-based fuzzy inference system(ANFIS),and gene expression programming(GEP).44 samples were used for training randomly while the remaining samples were employed for testing.We show that GEP outperforms MLR,MLnER,and ANFIS.The results indicate that the rotation and deflection of the CTMC depend on the temperature.In addition,the fire resistance increases with a decrease in the beam length;thus,a shorter beam can increase the fire resistance of the building.The numbers of flanges and web bolts slightly affect the rotation and displacement of the CTMCs at temperatures of above 400℃.

关键词： column-tree moment connection Finite element model parametric study fire regression models gene expression programming

Impacts of fire suppression on above‐ground carbon stock and soil properties in Borana rangelands,southern Ethiopia

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Grassland Research 2023年第1期2卷 1-14页

作者： Kenea Feyisa Sheleme Beyene Ayana Angassa School of Plant and Horticultural Sciences College of AgricultureHawassa UniversityHawassaEthiopia Department of Range and Forest Resources Botswana University of Agriculture and Natural ResourcesGaboroneBotswana

Background:fire is a natural disturbance that releases carbon back into the atmosphere.Pastoralists have used fire for many thousands of years for rangeland management.The use of fire in the Borana rangelands of southern Ethiopia was a common practice to improve the productivity of the rangelands.However,the use of fire as a tool to manage rangeland was prohibited by government policy in the early 1970s.Methods:In this study,we assessed the long‐term impacts of fire suppression on aboveground carbon stocks of woody and herbaceous biomass,soil organic carbon stocks,and total nitrogen stocks at burned versus adjacent unburned areas in the Borana rangelands of southern Ethiopia.The investigation was conducted in two locations:Dikale and Sanke.The upland location was represented by Dikale,while the bottomland location was represented by Sanke.Each study site was replicated three times,with burned versus adjacent unburned areas representing each replicate.Soil samples were collected in three soil depths(0–5,5–15,and 15–30 cm),while vegetation attributes were collected from 60 plots within three burned and three adjacent unburned sites in each landscape.Results:The soil organic carbon stock and pooled carbon stock between burned and unburned sites across the two landscapes showed minimal variation.The above‐ground carbon biomass accumulation for woody and herbaceous plants did not show any significant difference between burned and unburned sites both at the bottomland and upland areas.The total nitrogen contents recorded at uplands in burned sites were significantly(p<0.05)higher than the total nitrogen stocks for the unburned adjacent sites.Conclusions:Burned areas accumulated relatively more carbon stocks in terms of herbaceous biomass(3.27±0.43 Mg ha^(−1))than the adjacent unburned areas(0.98±0.43 Mg ha^(−1)).The results of the current study suggest that burning improved the carbon sequestration potential of herbaceous plants in arid savanna ecosystems.

关键词： aboveground biomass carbon carbon sequestration fire soil nitrogen

Rapid on-site identification of hazardous organic compounds at fire scenes using person-portable gas chromatography-mass spectrometry(GC-MS)—part 1:air sampling and analysis

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Forensic Sciences Research 2020年第2期5卷 134-149页

作者： Rylee Lam Chris Lennard Graham Kingsland Paul Johnstone Andrew Symons Laura Wythes Jeremy Fewtrell David O’Brien Val Spikmans School of Science and Health Western Sydney UniversityPenrithAustralia fire&Rescue NSW Fire Investigation and Research UnitGreenacreAustralia Operations Capability Directorate Fire&Rescue NSWGreenacreAustralia Environment Protection Science Branch Office of Environment and HeritageLidcombeAustralia Hazardous Incidents and Environmental Health Branch New South Wales Environment Protection AuthoritySydneyAustralia Strategic Capability Fire&Rescue NSWGreenacreAustralia

Recent advancements in person-portable instrumentation have resulted in the potential to provide contemporaneous results through rapid in-field analyses.These technologies can be utilised in emergency response scenarios to aid first responders in appropriate site risk assessment and management.Large metropolitan fires can pose great risk to human and environmental health due to the rapid release of hazardous compounds into the atmosphere.Understanding the release of these hazardous organics is critical in understanding their associated risks.Person-portable gas chromatography-mass spectrometry(GC-MS)was evaluated for its potential to provide rapid on-site analysis for real-time monitoring of hazardous organic compounds at fire scenes.Air sampling and analysis methods were developed for scenes of this nature.Controlled field testing demonstrated that the portable GC-MS was able to provide preliminary analytical results on the volatile organic compounds present in air samples collected from both active and extinguished fires.In-field results were confirmed using conventional laboratory-based air sampling and analysis procedures.The deployment of portable instrumentation could provide first responders with a rapid on-site assessment tool for the appropriate management of scenes,thereby ensuring environmental and human health is proactively protected and scientifically informed decisions are made for the provision of timely advice to stakeholders.

关键词： Forensic sciences gas chromatography-mass spectrometry portable GC-MS air pollution fire volatile organic compounds field analysis needle trap