Flammability estimation of 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide

Ionic liquids (ILs) are known as room temperature molten salts, which are considered green replacement to traditional organic solvents. The fire hazards of traditional organic solvents mainly depend on the combustibility of their vapors, thus ILs are generally regarded as nonflammable owing to their low volatility. However, recent studies show that ILs may combust due to the potential hazards of thermal decomposition, indicating the issue of fire and explosion of ILs are eager to be evaluated during the applications. In this study, the fire and explosion hazards of IL 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C₆mim][NTf₂]) are explored in different aspects. The traditional definition of the flammability for the common organic solvent is not thoroughly applicable to [C₆mim][NTf₂] due to the low volatility. Furthermore, the common definition of reactivity for traditional organic solvents also fails to apply, because the decomposition reaction is indeed an endothermic reaction. However, the auto-ignition of some decomposition products will result in fire and explosion hazards for [C₆mim][NTf₂]. Therefore the application of such data in safety purposes should be very careful.     

Graphical Presentation of 50/60 Hz Magnetic Field Contours as an Engineering Tool for Minimizing ELF Fields

Summary Since IARC classified ELF magnetic field as Possibly Carcinogenic to Human the fear from 50/60 Hz magnetic field exposure had been increased to the state of public “panic”. Subsequently, environment quality preservation organizations increased their pressure on their government to adopt the “precautionary principle” and to reduce the allowable ELF Magnetic Field exposure to much lower values than are recommended by ICNIRP-1998. As an example the present Environmental Ministry in Israel recommendation is to lower the ELF Field exposure to 10 mG averaged over 24 h. As a result of this stringent exposure guideline imposed by the government, electrical engineers who are involved in the deployment and installation of large and medium electrical utilities, such as overhead power lines, transformers, UPS systems, electrical public transportation, switching stations, etc., are much more aware to the need to employ special measures and methods for reducing the magnetic fields that might be emitted from such utilities. There are few computer codes that are capable of analyzing with great accuracy magnetic and electric fields surrounding single phase and three phase electrical utilities in a 3-D system. The best presentations of the analysis results are by equi-value contours depicting electric and magnetic fields. This graphical presentation is a powerful design tool that enables better deployment and installation design aided to reduce the magnetic field emissions from high-power electrical utilities. This paper describes the various types of graphical presentations available for ELF field contours, the dependent and independent variants and parameters, magnetic field animation for optimization of power line installation and routing, and finally an example that demonstrates the usefulness of the graphical presentation tools.     

Towards an Integrated Approach to Natural Hazards Risk Assessment Using GIS: With Reference to Bushfires

This paper develops a GIS-based integrated approach to risk assessment in natural hazards, with reference to bushfires. The challenges for undertaking this approach have three components: data integration, risk assessment tasks, and risk decision-making. First, data integration in GIS is a fundamental step for subsequent risk assessment tasks and risk decision-making. A series of spatial data integration issues within GIS such as geographical scales and data models are addressed. Particularly, the integration of both physical environmental data and socioeconomic data is examined with an example linking remotely sensed data and areal census data in GIS. Second, specific risk assessment tasks, such as hazard behavior simulation and vulnerability assessment, should be undertaken in order to understand complex hazard risks and provide support for risk decision-making. For risk assessment tasks involving heterogeneous data sources, the selection of spatial analysis units is important. Third, risk decision-making concerns spatial preferences and/or patterns, and a multicriteria evaluation (MCE)-GIS typology for risk decision-making is presented that incorporates three perspectives: spatial data types, data models, and methods development. Both conventional MCE methods and artificial intelligence-based methods with GIS are identified to facilitate spatial risk decision-making in a rational and interpretable way. Finally, the paper concludes that the integrated approach can be used to assist risk management of natural hazards, in theory and in practice.     

城市重大危险源免疫机制研究

为了更好地管理和控制城市重大危险源,在建立城市重大危险源的应急管理网络模型的基础上,利用生物免疫系统网络和城市重大危险源管理网络的相似性,采用生物免疫系统的相关理论和方法,对城市重大危险源的免疫机制进行了研究;根据城市重大危险源应急管理网络模型和城市重大危险源免疫机制,建立城市重大危险源应急网络的免疫模型,为加强对我国城市重大危险源的管理提供策略和方法。     

珠江三角洲地区人类活动造成的水土流失及其危害──以广州市为例

以广州市为例,重点分析人类活动造成的水土流失现状与危害。广州市的水土流失类型可分为自然侵蚀和人为侵蚀,其中自然侵蚀主要有面蚀、沟蚀两种形式,在广州市范围面积分布相对较广,但侵蚀强度内并不严重;而人为侵蚀突出,侵蚀类型和强度也更为复杂多样。人为侵蚀的成因主要有：采石取土、交通道路建设、开发区建设以及坡耕地。人为侵蚀已经成为广州市水土流失灾害的主要表现形式。     

危险化学品重大危险源辨识中存在问题的研究与探讨

根据对GB18218—2000《重大危险源辨识》和新标准GB18218—2009《危险化学品重大危险源辨识》以及国内外重大危险源辨识标准的对比分析,提出我国危险化学品重大危险源辨识中存在的四大问题。针对重大危险源涵盖种类仍不齐全的问题,提出将重大危险源从能量和物质两个角度划分,即标准涵盖的危险源种类应加入危险能量重大危险源;针对临界量不合理的问题,提出以死亡半径作为分界点,通过模拟计算确定危险物质的临界量的方法,使确定出的临界量符合相关法律法规规定量;针对重大危险源单元范围划分不合理的问题,提出采用模拟计算,以火灾爆炸事故破坏范围中的财产损失半径来定义单元覆盖距离的方法;针对缺少重大危险源危险性分级方法的问题,通过分析比较国内较为流行的几种重大危险源分级技术的优缺点及适用条件,提出多种分级方法结合的组合式分级方法。     

改进的专家评体系在长输管道风险评价中的应用

结合国内环境条件、运行状况和管理水平等实际情况,对长输气管道指数法风险评价体系进行修正,并举出了应用实例。     

Reaction hazards of triethylaluminum under closed conditions

We evaluate the reaction hazards of triethylaluminum (TEA) under closed conditions for safe treatment of aluminum alkyls. The explosive reactions of TEA are difficult to be estimated using thermal analysis because the estimate reactions are too slow under these conditions. The results of our closed vessel tests and chemical equilibrium calculations show that the TEA and water system mixture in closed conditions decomposes into lower-molecular-weight compounds than the products by using well-known hydrolysis of TEA. The present work also demonstrates that large temperature and pressure increases could occur because of the existence of TEA and aluminum hydroxide. Since aluminum hydroxide contains water as alumina hydrates, aluminum hydroxide could have been the source of water at high temperatures and could have contributed to the mixed reaction between TEA and water.     

Societal risk assessment of major hazard installations using QuickRisk

QuickRisk is a quantitative risk assessment tool developed at the Health and Safety Laboratory for use in assessing societal risk around onshore major hazard installations to inform land-use planning decisions. It uses release scenario information, parameterised consequence models, weather data, and population data from the National Population Database (NPD).This paper describes enhancements to the NPD methodology to include workplace populations. It describes the novel numerical, graphical and geographical representations of societal risk produced by QuickRisk. F–N data are analysed in terms of scenario FN curves and Delta PLL vs. N curves, where PLL is potential loss of life. The Delta PLL curves could be useful for comparison of FN curves against FN criterion lines or other FN data on a PLL basis. Geographical representations generated from PLL density maps show: the distribution of PLL dominating release scenarios or the percentage of risk contributed by the PLL-dominant release scenario, the maximum number of fatalities associated with the worst-case event, and the associated release scenario. Geographical representations are also generated of the maximum population that would meet a PLL density criterion, and the relative population change that would match a given PLL density criterion.These novel representations of societal risk could be useful for more effective communication between stakeholders on the risk levels in the vicinity of major hazard installations.