基于能位测定和示踪检测法的地下煤火漏风状态研究

应用能位测定法和示踪检测技术联合检测了鸡西老二井火区地下漏风状态。通过测试计算相对总压值得出了火区范围内井巷系统与采空区的风流关系,进而定性确定了火区内老二井与胜利井之间存在的可能漏风路径。在此基础上,利用瞬时释放示踪气体法确定了胜利井和老二井间的漏风方向和漏风速度,计算得出了火区下采空区内平均直线漏风风速为0.13m/s,漏风量为776m3/min。研究结果为矿区采取针对性的防灭火措施提供依据,并为同类问题的解决提供参考。     

车用环向缠绕气瓶原型选型分析与建议

针对业内对车用环向缠绕气瓶设计文件鉴定和型式试验工作中存在选型分歧这一实际问题,通过综合分析气瓶设计规则、型式试验规则和产品标准的要求,对该产品的原型选择进行讨论,提出一个能够符合国家标准、合理体现制造厂家诉求、且能与设计鉴定、型式试验工作相适应的选型建议。     

一起钢质无缝气瓶爆炸事故技术分析

文章简要描述了一起消防气体灭火钢质气瓶爆炸事故,对爆炸气瓶进行了断口分析、金相试验和理化试验,并分析了事故的原因,提醒制造厂家规范制造工艺,对预防类似事故的发生具有一定的参考意义。     

Validation of the UN test method N.5

Many substances react with water in such a way that flammable gases are formed. For transport issues this reaction may possess a considerable hazard especially if the cargo is wetted by rain or by water from other sources. In the UN Recommendations on the Transport of Dangerous Goods these kinds of problems are addressed. The UN test N.5 “Test method for substances which in contact with water emit flammable gases” corresponds to this hazard. Classification according to the test method is done by measurement of the gas evolution rate of the flammable gas by any suitable procedure. At BAM a gravimetric approach is used to measure the gas evolution rate. In this paper we present the evaluation of the apparatus by means of an absolute calibration routine utilizing a reaction where a known amount of gas is produced as well as the evaluation of important parameters influencing the gas evolution rate using different substances. It can be shown that the apparatus is capable of measuring absolute gas volumes as low as 6 mL with an acceptable error of about 17% as determined from the reaction of Mg with demineralized water.     

氧化沟工艺处理火车站废水的运行与调试

以信阳市火车北站污水处理工程为例．介绍了以一体化氧化沟工艺为主的处理工艺及其主要构筑物如：泵井、平流沉砂池、氧化沟以及接触消毒池的结构特点和设计水力负荷条件等。针对火车站废水特有的含油污量高、可生化性差的特点．指出了其运行与调试过程中应注意的问题。     

DMF降解菌MBYD-1的分离、鉴定及降解特性

从农药厂污水处理池的活性污泥中分离得到一株能以二甲基甲酰胺(DMF)为唯一碳、氮源生长的菌株MBYD-1.经形态观察、生理生化实验及16S rRNA基因序列分析,将菌株初步鉴定为假单胞菌属 (Pseudomonas sp.).菌株MBYD-1降解DMF的最适条件为:pH 7.0,30℃.当DMF浓度为400mg/L,接种量为2%时,菌株能在72h内将DMF完全矿化.底物广谱性实验表明,菌株MBYD-1能在甲酸盐和甲醛中很好地生长,在甲酰胺中的生长情况优于二甲胺.     

Leaching characteristics of bisphenol A from epoxy-resin pavement materials

We investigated the leaching characteristics of bisphenol A (BPA) from two kinds of epoxy-resin pavement materials, one containing epoxy resins (EPs) and the other containing epoxy-acrylate resins (EPAs). Both samples contained residual BPA monomer, at levels of 9.0?µg?g^?1 for the EP resin sample and 4.4?µg?g^?1 for the EPA resin sample. These amounts were larger than amounts previously measured for polycarbonate samples. The amount of BPA leached from the samples increased with temperature. The leaching of BPA from EP was more strongly affected by temperature than the leaching from EPA. The pH also affected the amount of leached BPA. The maximum leached amount was observed under alkaline conditions (pH 10.8) for both sample types. The amounts of BPA that might leach from pavement materials during 1?h of heavy rain were estimated to be 0.9?µg?m^?2 for EP and 3.5?µg?m^?2 for EPA. Our results indicate that EPs disposed of in waste landfills without any treatment may be a source of BPA in leachate at landfill sites.     

Effects of repeated pesticide exposure on the peripheral and central nervous systems

This study was designed to compare organic farmers (comparison group) and pesticide-using farmers (pesticide group) in terms of neurobehavioral performance and sensorimotor function. The subjects were recruited in October 2004 from Chungnam Province and the neighboring Jeolla Province in western South Korea. Psychological assessment was carried out using the Wechsler Adult Intelligence Scale, the Mini-Mental State Examination, and the Bender Gestalt test. Neuroselective sensory nerve conduction threshold was measured at both left and right middle fingers by using an electrodiagnostic device to determine current perception thresholds (CPTs). Three independent CPT measurements were obtained from each test site by using sinusoidal stimuli at three frequencies. CPT testing showed no difference between the two groups. No significant differences were found in the large myelinated (2000?Hz stimulation; cutaneous touch, pressure), small myelinated (250?Hz stimulation; mechanoreceptive, pressure, temperature, fast pain) and small unmyelinated (5?Hz stimulation; polymodal nociceptive, temperature, slow pain, postganglionic sympathetic) C-fibers. Furthermore, there was no difference found between the pesticide and comparison groups in psychological variables, including intelligence quotient, orientation, memory, calculation, similarities, visual sensitivity, and psychomotor speed. In conclusion, chronic pesticide exposure has no apparent effect on either the peripheral or central nervous system in Korean farmers.     

Mutagenicity of diesel engine exhaust in the Ames / Salmonella assay using a direct exposure method

The aim of this study was to investigate the potential mutagenic activity of diesel engine exhaust in the Ames/Salmonella assay using a direct aerosol exposure system. So, TA 98 and TA 100 strains, with or without added S9 mix, were exposed to diesel emissions after varying degrees of filtration. Variants of these two strains, deficient in nitroreductase (TA 98NR and TA 100NR) or over-expressing O-Acetyl Transferase (YG 1024 and YG 1029), were also exposed to total (unfiltered) diesel exhaust to highlight the putative mutagenicity of any nitro-PAHs present in these emissions. Mutagenic activity of the diesel exhaust was demonstrated on Salmonella typhimurium, strains TA 100 and variants TA 100 NR and YG1029. The use of a particle filter did not modify the genotoxicity of the diesel emissions, indicating a major contribution of the gas phase to the mutagenicity of these diesel emissions. The prominent role of the particulate-associated nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) claimed by some authors working on diesel exhaust organic extracts was not confirmed by our results with native diesel exhaust exposure. Our results show that the gas phase is potentially more mutagenic than the particles alone.     

Genotoxic effects of two different classes of insecticide in developing chick embryos

Pesticides provide considerable protection against pest population; however, rampant accumulation of these chemicals into varied habitats across the globe necessitates the need for a careful screening of each chemical due to toxic manifestations. In the current study, the genotoxic potential of two different classes of commercial insecticides – chlorpyrifos and cypermethrin combination and Spinosad, a naturalyte were compared. Rhode Island Red chick embryos were exposed to different doses of either of these insecticides individually, by in ovo treatment. Genotoxicity was then evaluated through micronucleus (MN) test and Comet assay. The combination insecticide exposure at low doses of 0.05 and 0.1 μg/egg induced DNA damage as evidenced by an increased tail moment in the Comet assay. Further, the presence of micronucleated erythrocytes and also various abnormal cells including dacryocytes, microcytes, erythroplastids, squashed/notched nuclei, and spindle-shaped erythrocytes in the blood smear consolidates indicate the presence of insecticide-induced genotoxicity. Spinosad, however, was found only mildly genotoxic but at a high dose of 1.5 mg/egg. The results indicate that usage of naturalyte insecticide may be a better option to minimize the harmful effects of chemical insecticides.