Maintenance-related major accidents: Classification of causes and case study

The potential for major accidents is inherent in most industries that handle or store hazardous substances, for e.g. the hydrocarbon and chemical process industries. Several major accidents have been experienced over the past three decades. Flixborough Disaster (1974), Seveso Disaster (1976), Alexander Kielland Disaster (1980), Bhopal Gas Tragedy (1984), Sandoz Chemical Spill (1986), Piper Alpha Disaster (1988), Philips 66 Disaster (1989), Esso Longford Gas Explosion (1998), Texas City Refinery Explosion (2005), and most recently the Macondo Blowout (2010) are a few examples of accidents with devastating consequences.Causes are being exposed over time, but in recent years maintenance influence tends to be given less attention. However, given that some major accidents are maintenance-related, we intend to concentrate on classifying them to give a better insight into the underlying and contributing causes.High degree of technological and organizational complexity are attributes of these industries, and in order to control the risk, it is common to deploy multiple and independent safety barriers whose integrity cannot be maintained without adequate level of maintenance. However, maintenance may have a negative effect on barrier performance if the execution is incorrect, insufficient, delayed, or excessive. Maintenance can also be the triggering event.The objectives of this article are: (1) To investigate how maintenance impacts the occurrence of major accidents, and (2) To develop classification schemes for causes of maintenance-related major accidents.The paper builds primarily on model-based and empirical approaches, the latter being applied to reports on accident investigation and analysis. Based on this, the Work and Accident Process (WAP) classification scheme was proposed in the paper.     

污水排海扩散器的数值模拟与模型试验

在污水排海工程的设计工作中,采用数值模拟与模型试验相结合的方法是一种有效的设计手段。本文结合某污水排海整治工程,首先采用HydroInfo-1D管网模型对该工程排污扩散器进行数值模拟,得到相应各喷口的流量、流速和弗劳德数,然后设计水工模型试验对数值模拟结果进行验证。模拟结果显示,两种排放流量工况下该扩散器各喷口出流均具有很好的均匀性,且弗劳德数均大于1,满足设计规范的要求。此外,通过将实验结果与计算结果对比,发现两种工况下流量的计算值与实验值的最大误差分别为2.18%和2.42%,流速的最大误差分别为2.19%和2.43%,说明该模型的计算结果具有较高的精度。研究结果表明:该模型可以准确的对污水排海扩散器进行模拟,且管道的设计结构参数满足实际运行要求。     

Location and PCR analysis of catabolic genes in a novel Streptomyces sp. DUT AHX capable of degrading nitrobenzene

A novel strain of Streptomyces sp.DUT_AHX was isolated from sludge contaminated with nitrobenzene and identified on the basis of physiological and biochemical tests and 16S ribosomal DNA (rDNA) sequence analysis.The optimal degradation conditions were as follows:temperature 30℃,pH 7.0-8.0,shaking speed 150-180 r/min,and inocula 10%(V/V).The strain,which possessed a partial reductive pathway with the release of ammonia,was also able to grow on mineral salts basal (MSB) medium plates with 2-aminophenol, ph...     

层次分析法在新疆民丰县地质灾害空间预测中的应用

通过野外调查分析了新疆民丰县地质灾害发育规律,运用层次分析法(AHP)建立地质灾害易发性评价结构模型及判断矩阵,用以确定影响地质灾害易发程度的各因素权重,建立区域地质灾害易发性评价的数学模型,并得出基于GIS平台的区域地质灾害易发性预测分区图.通过对比野外调查灾害隐患点分布情况,证明该方法比较合理,预测结果与实际地质灾害发育区的拟合率大于80%.     

无机膜除尘器烟气脱硫的试验研究

采用自动烟气分析,通过试验分析无机膜除尘器的脱硫机理和影响因素,试验结果表明在本试验的工况下无机膜除尘器有2.0%～5.7%的脱硫效率,无机膜除尘器在脱硫的过程中起到固定床反应器的作用,同时蒸汽活化粉尘使其中的碱性物质的释放是无机膜除尘器脱硫的关键.     

碳中和视域下的垃圾精细化治理：日本吸收性卫生用品回收体系的构建经验及启示

通过循环利用，减少吸收性卫生用品产量和废弃量的陡增所带来的碳排放量，将加速碳中和进程。日本提供了吸收性卫生用品回收体系构建的先行经验，即以“政府引导—企业运作—社会团体协作”为顶层架构，明确制度、完备设施、完善渠道、宣传到户等。建议我国取长补短，在夯实法律法规和优化主体协同机制的基础上，重点着眼于突破技术壁垒、推动智慧化监管、深化绿色理念，以点带面推进吸收性卫生用品的回收循环试点，进一步推动垃圾分类精细化治理的进程。