安全评价方法在危险废物处置环境风险评价中的应用探讨

对安全评价方法在危险废物处置建设项目环境风险评价中的运用进行初步探索。主要用"工艺过程风险因素分析表"对工艺过程潜在风险性识别;用蒙德法进行源项分析;用池火灾模型、蒸气云爆炸伤害模型对易燃、易爆物质的火灾、爆炸等重大事故后果进行计算,得出人员的伤亡半径和财产损失半径等参数,以便于判断风险的可接受水平。分析结果表明:采用安全评价方法对危险废物处置建设项目进行环境风险评价是适用的、可行的。     

Random parameter models for accident prediction on two-lane undivided highways in India

Introduction

Generalized linear modeling (GLM), with the assumption of Poisson or negative binomial error structure, has been widely employed in road accident modeling. A number of explanatory variables related to traffic, road geometry, and environment that contribute to accident occurrence have been identified and accident prediction models have been proposed. The accident prediction models reported in literature largely employ the fixed parameter modeling approach, where the magnitude of influence of an explanatory variable is considered to be fixed for any observation in the population. Similar models have been proposed for Indian highways too, which include additional variables representing traffic composition. The mixed traffic on Indian highways comes with a lot of variability within, ranging from difference in vehicle types to variability in driver behavior. This could result in variability in the effect of explanatory variables on accidents across locations. Random parameter models, which can capture some of such variability, are expected to be more appropriate for the Indian situation.

Method

The present study is an attempt to employ random parameter modeling for accident prediction on two-lane undivided rural highways in India. Three years of accident history, from nearly 200 km of highway segments, is used to calibrate and validate the models.

Results

The results of the analysis suggest that the model coefficients for traffic volume, proportion of cars, motorized two-wheelers and trucks in traffic, and driveway density and horizontal and vertical curvatures are randomly distributed across locations.

Conclusions

The paper is concluded with a discussion on modeling results and the limitations of the present study.     

Highlights of LNG risk technology

The authors have recently undertaken a major review of LNG consequence modeling, compiling a wide range of historical information with more recent experiments and modeling approaches in a book entitled “LNG Risk-Based Safety: Modeling and Consequence Analysis”. All the main consequence routes were reviewed – discharge, evaporation, pool and jet fire, vapor cloud explosions, rollover, and Rapid Phase Transitions (RPT’s). In the book, experimental data bases are assembled for tests on pool spread and evaporation, burn rates, dispersion, fire and radiation and effects on personnel and structures. The current paper presents selected highlights of interest: lessons learned from historical development and experience, comparison of predictions by various models, varying mechanisms for LNG spread of water, a modeling protocol to enable acceptance of newer models, and unresolved technical issues such as cascading failures, fire engulfment of a carrier, the circumstances for a possible LNG BLEVE, and accelerated evaporation by LNG penetration into water.     

基于风险预控的煤矿安全管理长效机制构建

根据风险预控原理,指出煤矿企业应当正确区分隐患和危险源,遵循危险源辨识-监测-控制的基本思路,建立了煤矿风险预控的流程,并界定了危险源辨识、危险源监测和危险源控制的内容。在风险预控理论的基础上,从制度保证和体制支撑两个方面设计了煤矿安全管理的长效机制。分析认为：为保障煤矿的长治久安,应从理顺安全管理体制,落实安全责任制度;实施危险源闭环管理;加强安全培训,实施安全管理人员准入制度;健全安全考核制度,实行奖惩激励四个方面加强安全管理。     

市政建设项目危险源评价方法研究与应用

在市政建设行业的安全管理中,危险源辨识与评价一直处于非常重要的地位。本文比较了目前较常用的 LEC 评价法和 MES 评价法优缺点,借鉴 MLEC 评价法相关知识,得出危险源辨识难易程度及防护措施的不同对评价结果的影响,并利用评价得出的危险源危险性以及规范的防护措施来保障市政建设项目的施工安全。     

张集矿综采工作面瓦斯治理措施及效果分析

张集矿属于煤与瓦斯突出矿井,针对目前所开采的17266工作面地质构造条件复杂、瓦斯涌出量大、处于突出危险区等瓦斯治理难题,采取"风排瓦斯、高抽巷穿层钻孔抽采、运输巷、回风巷顺层钻孔抽采和上隅角埋管抽采"等瓦斯综合治理措施,用分源预测法得出工作面绝对瓦斯涌出量为30.3 m3/min。结果表明,工作面的主要瓦斯涌出来源为本煤层瓦斯涌出。工作面风排瓦斯量11.0 m3/min,工作面瓦斯抽采率达63.0%以上。     

隧道内偏置火源顶棚近壁面温度边界层效应研究

基于隧道火灾不同横向火源位置的非对称卷吸影响,通过模拟计算分析了中心火源和偏置火源产生的烟气沿纵向最大温升变化规律,研究了顶棚下方近壁面区域内的不同温度分布,提出偏置火源纵向空间最大顶棚温升公式。结果表明:在壁面黏性作用下,沿纵向蔓延的烟气最高温度在顶棚下方呈现“温度边界层”分布;随着火源位置的偏移,下游出现偏置距离起主导作用影响温度衰减的区域,衰减速度相较于中心火源逐渐降低;火源下游近壁面最高温度位置逐渐远离顶棚后趋于稳定。研究结果对于排烟方式的设计以及空间通风效果的提升有着重要意义。     

江苏淮河流域工业点源负荷空间分布特征研究

搞清流域工业点源的空间分异特征,可为水环境整治与工业规划提供参考依据。采用工业污染源普查数据建立污染源信息数据库,在GIS技术、密度分析法与ESDA方法支撑下,探析江苏淮河流域工业点源与工业污染负荷空间格局与特征。结果显示：工业点源集聚于城市、县城及专业乡镇,污染行业地域分异现象显著,其中,河流、港口及临湖地区成为高负荷工业点源集聚地区,化工、造纸、化纤与医药等行业的工业集中于临海、临河及临湖地区,饮料制造业、副食品加工业点源集中于工业化水平较低的北部流域的少数乡镇,工业氨氮多数来自化工业。在不同工业化水平下,工业污染负荷空间差异大,南部流域负荷整体水平高于北部,北部流域高负荷区分布于少数乡镇与城区     

Coupled radon, methane and nitrate sensors for large-scale assessment of groundwater discharge and non-point source pollution to coastal waters

We constructed a survey system of radon/methane/nitrate/salinity to find sites of submarine groundwater discharge (SGD) and groundwater nitrate input. We deployed the system in Waquoit Bay and Boston Harbor, MA where we derived SGD rates using a mass balance of radon with methane serving as a fine resolution qualitative indicator of groundwater. In Waquoit Bay we identified several locations of enhanced groundwater discharge, out of which two (Childs and Quashnet Rivers) were studied in more detail. The Childs River was characterized by high nitrate input via groundwater discharge, while the Quashnet River SGD was notable but not a significant source of nitrate. Our radon survey of Boston Harbor revealed several sites with significant SGD, out of these Inner Harbor and parts of Dorchester Bay and Quincy Bay had groundwater fluxes accompanied by significant water column nitrogen concentrations. The survey system has proven effective in revealing areas of SGD and non-point source pollution.     

太湖地区典型小流域非点源污染物流失规律 --以宜兴梅林小流域为例

由农业产生的非点源污染是湖泊的主要污染源。为了研究太湖流域非点源污染负荷流失规律,选择了宜兴梅林小流域为研究对象,对降雨过程中径流流量及其污染物浓度随降雨—径流变化过程进行监测研究。采用统计和系统分析方法,建立径流量和非点源污染负荷输出量之间的数学统计模型,得出该流域非点源污染物流失规律,此方法可以推广到与该流域相似的其它地区的非点源污染研究中,应用于太湖流域水污染综合治理。