Computer simulations help determine safe vertical boom speeds for roof bolting in underground coal mines

PROBLEM: Incident investigation reports do not usually contain enough information to aid in studying boom arm vertical speed for roof bolting machines to determine the impact that appendage speed had on an operator's risk of experiencing a contact. Laboratory experiments with human subjects are also not feasible because of safety and ethical issues. METHOD: Researchers successfully developed a three-dimensional computer model that uses virtual human simulation software as the primary means to gather contact data when the boom arm touches the operator's hand, arm, head, or leg. RESULTS: Data analysis of roof bolter simulations shows that the speed of the boom arm is the most important factor in determining the risk of an operator making contact. Regardless of other variables, contact incidents were always greater when the bolter arm was moving up, greater on the hand, and greater for the boom arm part of the machine. The reason why the subject experiences more contacts when the boom arm is moving up rather than down is that more risky behaviors occur during drilling and bolting when the boom arm is ascending. Based on the data collected, boom speeds greater than 13 in/sec result in a substantial increase in risk to the roof bolter operator of making contact. Speeds less than or equal to 13 in/sec are associated with a more modest relative risk of making contact, which represents a decrease in potential hazard. IMPACT ON INDUSTRY: The use of such information can be quite helpful in making recommendations to machine design and task procedures to reduce the likelihood that roof bolter operators will experience injury due to contact with a moving roof bolting machine's boom arm.     

高耸构筑物地基变形和风振对爆破拆除安全性的影响

本文对高耸构筑物控爆前的倾斜、失稳的诱发因素(地基变形、风振)进行了探讨,当高耸构筑物向倾斜相反方向倒塌时,必须从地基、基础、上部结构三者之间的变形协调条件和静力平衡条件综合考虑进行爆破设计,施爆时必须采取一定的技术措施.     

广州城市人工水系统中军团菌的发生和分布

综合运用平板分离法、半巢式PCR和EnviroAmp PCR反向杂交检测试剂盒，对广州市部分人工水系统中条件致病菌军团菌属细菌进行分离和检测．结果表明，虽然阳性率随着采样时间和地点的不同而有所差异，但总体来说，广州市人工水系统中存在较高程度的军团菌的污染，中央空调冷却塔水中军团菌阳性率平均为84％，个别路段甚至达到了100%，自来水池中则达到了35％，，但在后者的水样中没有检测到最常见的致病菌嗜肺军团菌．对各种培养方法的优劣及军团菌的季节性发生和分布进行了初步讨论．图2表2参16     

Enumeration of Legionella pneumophila in cooling tower water systems

Legionella pneumophila, the causative agent of Legionnaires disease, is known to colonise and frequently grow in cooling tower waters. Disease is acquired by inhaling aerosol contaminated by legionellae. Determination of the count of Legionella pneumophila in cooling tower waters may, therefore, be useful for risk assessment. In our survey, 103 water samples from 50 cooling towers were examined over a five-year period to indicate the seasonal distribution and the ecology of L. pneumophila, as regards temperature and pH. L. pneumophila serogroup 1 was found in 44% of the isolated strains, which is primarily responsible for the majority of Legionnaires disease. The large majority of examined towers had levels of L. pneumophila in the high-risk category. These cooling towers have been linked to many outbreaks of Legionnaires disease.     

喷雾增湿设备的数学模拟设计

系统论述了喷雾增湿塔内水滴的运动状态与含尘气体的流动特性,建立了一个能反映喷雾增湿操作过程的数学模型,有助于确定该设备生产操作中的最佳控制参数.     

对开好单塔污水汽提粗氨精制系统的论述

介绍开好单塔污水汽提粗氨精制系统的必要性，以及技术改造和技术分析，通过技术改造后，产品液氨的质量得到了明显提高。     

循环冷却水中军团菌的控制

随着我国社会经济的不断发展,循环冷却水系统在工业、商业和民用设施以及大型公共设施中的应用日益广泛。然而,这些水系统在给人们生活带来便利的同时,也为一种严重危害人类健康的细菌——军团菌创造了滋生的场所。国外对军团菌的研究报道已经很多,有些国家甚至已经开始为控制军团菌进行立法,然而国内在这方面的报道很少,研究也不多。因此,通过对军团菌、军团病以及控制军团菌的方法的介绍,唤起全社会对军团菌的关注。     

逆流式冷却塔噪声污染防治

该文介绍了逆流式冷却塔运行原理及噪声扰民治理的实例。并提出相应的措施。     

湿法吸收法处理氮氧化物废气

介绍了湿法吸收氮氧化物工业废气的方法，并对吸收液和吸收塔进行了深入的探讨和研究。     

冷却塔改造

在冷却塔改造中，淋水填料和配水喷头的选择是提高热力性能的关键。本文详细介绍了淋水填料与配水喷头的选择