国外热防护服装性能测试技术标准研究

热防护服是热环境下人体安全防护的主要装备,其标准的科学性和系统性对热环境下的人体安全防护具有重要的支持作用.国外对热防护服相关的技术标准予以充分重视,以性能测试技术方法为主体,建立了较为科学、完善的标准,并体现出新的发展趋势.通过对国外热防护服技术标准的调研,总结性能测试标准的共性内容,包括主要性能测试方法、实验设备、实验步骤、烧伤评估、人体模型和测试报告等.整套防护服装的性能测试技术及标准是研究的重点,出汗暖体假人将在防护服装性能测试领域被更为广泛的应用.最后,提出我国研制热防护服性能测试技术标准的建议.     

Safety of stationary grinding machines – impact resistance of work zone enclosures

Guards on machine tools are intended to protect persons from being injured by parts ejected with high kinetic energy from the work zone of the machine. Stationary grinding machines are a typical example. Generally such machines are provided with abrasive product guards closely enveloping the grinding wheel. However, many machining tasks do not allow the use of abrasive product guards. In such cases, the work zone enclosure has to be dimensioned so that, in case of failure, grinding wheel fragments remain inside the machine’s working zone. To obtain data for the dimensioning of work zone enclosures on stationary grinding machines, which must be operated without an abrasive product guard, burst tests were conducted with vitrified grinding wheels. The studies show that, contrary to widely held opinion, narrower grinding wheels can be more critical concerning the impact resistance than wider wheels although their fragment energy is smaller.     

2002年11月-2003年2月国内安全事故数据

统计了2002年11—2003年2月国内发生的各种安全事故1050起，包括矿业事故、交通事故、爆炸事故、毒物泄露和中毒、火灾及其他事故。统计表明，在这些事故中，矿业事故最多，占59．8％，平均每天5．2起事故，其次是交通事故(23．1％)、爆炸事故(5．6％)、其他事故(5．6％)、毒物泄露和中毒(3．1％)、火灾(2．7％)。1050起事故共死亡2733人，伤2248人，死亡人数的百分比分别为矿业事故43．O％、交通事故37．1％、其他事故7．2％、爆炸事故6．8％、火灾3．9％、泄露中毒1．9％；受伤人数的百分比分别为交通事故63．7％、爆炸事故10．5％、矿业事故9．9％、泄露中毒6．9％、其他事故6．6％、火灾2．4％。章最后对2002年我国发生的一些事故进行了讨论。     

水泥土搅拌桩复合地基静载试验检测法的安全度分析

在检测水泥土搅拌桩复合地基的承载力能否达到设计要求时 ,最常用的方法是单桩静载试验法和复合地基静载试验法。工程实践中发现 ,采用这两种静载试验方法得到的检测结果存在较大差异。笔者根据水泥土搅拌桩的基本特性 ,结合工程实例 ,对这两种静载试验检测结果存在的差异及其安全度进行比较分析 ,得出单桩静载试验法结果的安全度高于复合地基试验法结果的结论 ,因此 ,提出了一些合理化建议     

小样本感度试验方法

提出了一种用于炸药及火工品感度试验的小样本方法。此方法较之传统的Ｂｒｕｃｅｔｏｎ升降法（估计方差一般需要３０ 个以上的试件,而且估计出的方差往往偏小）,可以在少于３０ 个试件的小样本的条件下,对方差进行估计,而且估计精度高。建立了高置信度、高可靠度的Ｐ发火刺激量置信限公式,该公式可以综合利用当前试验数据和以往经验数据,从而仅需少量当前试验,便可达到Ｂｒｕｃｅｔｏｎ 升降法采用３０ 个以上试件方能达到的精度,大大节省了试验的费用及时间。大量的ＭｏｎｔｅＣａｒｌｏ 模拟试验及实例分析都进一步证明了上述结论。     

国内外氧气逃生呼吸器标准比较研究

为了给氧气逃生呼吸器国家标准的制定提供参考,对比分析了国内外相关氧气呼吸器标准。研究结果表明:在保证人员安全前提下,结合产品定位于逃生目的,建议吸入气体中氧气含量的最低值≥15%,均值＞19.5%;二氧化碳含量的均值≤1.5%,峰值≤4%;最高温度≤50℃;吸气阻力≤1.2 kPa,呼气阻力≤1.2 kPa,两者之和≤1.8 kPa;实用性能引用GB/T 23465-2009中的要求。     

Study of chest injuries to 3-year-old child occupants seated in impact shield and 5-point harness CRSs

Objective: The objective of this study was to investigate whether the 5-point harness or the impact shield child restraint system (CRS) or both have the potential to cause chest injuries to children. This is determined by examining whether the loading to the chest reaches the internal organ injury threshold for children.

Method: The chest injury risk to a child occupant in a CRS was investigated using Q3 dummy tests, finite element (FE) simulations (Q3 dummy and human models), and animal tests. The investigation was done for 2 types of CRSs (i.e., the impact shield CRS and 5-point harness CRS) based on the UN R44 dynamic test specifications.

Results: The tests using a Q3 dummy indicated that although the chest deflection of the dummy in the impact shield CRS was large, it was less than the injury threshold (40 mm). Computational biomechanics simulations (using finite element FE analysis) showed that the Q3 dummy's chest is loaded by the shield and deforms substantially under this load. To clarify whether chest injuries due to chest compression can occur with an impact shield or with the 5-point harness CRS, 7 experiments were performed using Tibetan miniature pigs with weights ranging from 9.7 to 13 kg. Severe chest and abdominal injuries (lung contusion, coronary artery laceration, liver laceration) were found in the tests using the impact shield CRS. No chest injuries were present when using the 5-point harness CRS.

Conclusion: When using the impact shield CRS, the chest deformed substantially in dummy tests and FE simulations, and chest and abdominal injuries were observed in pig tests. It is possible that these chest injuries could also occur to child occupants sitting in the impact shield CRS.     

Testing of dust clouds for the electrostatic-spark ignition hazard in industry. Need for a modified approach?

Current standard test methods for electric-spark minimum ignition energies (MIEs) of dust clouds in air require that a series inductance of at least 1–2 mH be included in the electric-spark discharge circuit. The reason is to prolong the spark discharge duration and thus minimize the spark energy required for ignition. However, when assessing the minimum electrostatic energy ½CU² for dust cloud ignition by accidental electrostatic-spark discharges, current testing standards require that the series inductance of at least 1–2 mH be removed from the spark discharge circuit. No other changes of apparatus and test procedure are required. The present paper questions whether this simple approach is always adequate. The reason is that in practice in industry accidental electrostatic-spark discharge circuits may contain large ohmic resistances due to corrosion, poor electrical grounding connections, poorly electrically conducting construction materials etc. The result is increased spark discharge durations and reduced mechanical disturbance of the dust cloud by the blast wave emitted by the spark. Therefore, testing for minimum ½CU² for ignition by accidental electrostatic spark discharges may not only require removal of the series inductance of 1–2 mH from the standard MIE spark discharge circuit. Additional tests may be needed with one or more quite large series resistances R_s inserted into the spark discharge circuit. The present paper proposes a modified standard test procedure for measurement of the minimum electrostatic-spark ignition energy of dust clouds that accounts for these effects.     

复配型表面活性剂协同无机盐润湿煤尘性能研究*

为有效提高雾化降尘效率,以长焰煤为例,从接触角、表面张力静态试验和粒径测定、喷雾降尘动态试验角度切入,探究不同类型表面活性剂与无机盐的协同关系,进而优选出降尘效果最佳的配比方案。研究结果表明:阴与阴、阴与非、非与非离子复配型表面活性剂与无机盐之间均存在显著协同效应,且通过正交试验可确定协同效果最优的3组配方及其最佳浓度;对比清水,3组配方的平均粒径均有所减小,降尘效率均有大幅提升。综合优选出的最佳配比为质量分数0.08%的仲烷基磺酸钠、0.04%的曲拉通X-100和0.04%的氯化钙复合配制的溶液,该方案的全尘降尘效率为92.55%,比清水提升79.95%;呼尘降尘效率为91.27%,比清水提升82.36%。     

Implied-consent laws: A review of the literature and examination of current problems and related statutes

Problem

A substantial proportion of drivers arrested for DUI refuse the BAC test, thereby reducing the likelihood that they will be convicted and potentially increasing the number of high-risk multiple offenders contributing to alcohol-related crashes.

Method

This paper reviews the information on the current status of implied-consent laws (which impose a sanction on offenders who refuse the BAC test) in the 50 states and the other relevant traffic safety laws and policies that may influence state refusal rates.

Results

Although there appears to be only a weak relationship between state refusal rates and crash rates, there is strong evidence that BAC test refusals significantly compromise the arrest, prosecution, and sentencing of DUI suspects and the overall enforcement of DUI laws in the United States.

Discussion

Laws and policies that may reduce the number of refusals are discussed.

Impact on industry

Alcohol-related crash injuries are an important cost problem for U.S. industry because of property damage from crashes, crash injuries to employees that raise health costs, or the reduction of time on the job resulting from a highway injury.