Influence of seat foam and geometrical properties on BioRID P3 kinematic response to rear impacts

As the primary interface with the human body during rear impact, the automotive seat holds great promise for mitigation of Whiplash Associated Disorders (WAD). Recent research has chronicled the potential influence of both seat geometrical and constitutive properties on occupant dynamics and injury potential. Geometrical elements such as reduced head to head restraint, rearward offset, and increased head restraint height have shown strong correlation with reductions in occupant kinematics. The stiffness and energy absorption of both the seating foam and the seat infrastructure are also influential on occupant motion; however, the trends in injury mitigation are not as clear as for the geometrical properties. It is of interest to determine whether, for a given seat frame and infrastructure, the properties of the seating foam alone can be tailored to mitigate WAD potential. Rear impact testing was conducted using three model year 2000 automotive seats (Chevrolet Camaro, Chevrolet S-10 pickup, and Pontiac Grand Prix), using the BioRID P3 anthropometric rear impact dummy. Each seat was distinct in construction and geometry. Each seat back was tested with various foams (i.e., standard, viscoelastic, low or high density). Seat geometries and infrastructures were constant so that the influence of the seating foams on occupant dynamics could be isolated. Three tests were conducted on each foam combination for a given seat (total of 102 tests), with a nominal impact severity of Delta V = 11 km/h (nominal duration of 100 msec). The seats were compared across a host of occupant kinematic variables most likely to be associated with WAD causation. No significant differences (p < 0.05) were found between seat back foams for tests within any given seat. However, seat comparisons yielded several significant differences (p < 0.05). The Camaro seat was found to result in several significantly different occupant kinematic variables when compared to the other seats. No significant differences were found between the Grand Prix and S-10 seats. Seat geometrical characteristics obtained from the Head Restraint Measuring Device (HRMD) showed good correlation with several occupant variables. It appears that for these seats and foams the head-to-head restraint horizontal and vertical distances are overwhelmingly more influential on occupant kinematics and WAD potential than the local foam properties within a given seat.     

Head injuries in airbag-equipped motor vehicles with special emphasis on AIS 1 and 2 facial and loss of consciousness injuries

OBJECTIVES: Safety of the airbag supplemental restraint system (airbag) is a well-known concern. Although many lives are saved each year through airbag use, injuries continue to occur, especially to the head. Airbag safety research has focused primarily on severe injuries, while minor and moderate injuries have been largely ignored. METHODS: In this study, 205,977 injury cases from the 1995 to 2001 National Automotive Sampling System (NASS)/ Crashworthiness Data System (CDS) were surveyed to determine the prevalence of AIS 1 and 2 facial and brain loss of consciousness (LOC) injuries and determine if these injuries are a concern. The query was focused on frontal impacts in vehicles equipped with airbags. Only occupants wearing appropriate seatbelts were included in this study so that the airbag would provide occupant protection under optimal conditions. Of the 205,977 injury cases studied, 2.4% met this criterion. RESULTS: From the data gathered, the trends seem to indicate an increase in these specific injuries, both in terms of the total number and the proportion to all injury cases. In 1995, AIS 1 and 2 head injuries accounted for 96.5% of all head injuries caused by airbags. By 2001, the percentage had risen 3.0% to 99.5%. Injuries occurring in vehicles equipped with first-generation versus second generation airbags were compared, and data seem to suggest that there is a higher rate of minor and moderate head injuries when occupants are in second-generation airbag-equipped vehicles, even when appropriate lap and shoulder belts are used. CONCLUSIONS: The short timeframe surveyed prevents drawing meaningful conclusions about statistical significance, but the graphical representations of the data in this study underscore an urgent need for further investigation based on current trends in order to understand the issue of minor and moderate head injury prevention in regard to airbags.     

Influence of age-related stature on the frequency of body region injury and overall injury severity in child pedestrian casualties

OBJECTIVE: The current study aims to evaluate the influence of age-related stature on the frequency of body region injury and overall injury severity in children involved in pedestrian versus motor vehicle collisions (PMVCs). METHODS: A trauma registry including the coded injuries sustained by 1,590 1- to 15-year-old pedestrian casualties treated at a level-one trauma center was categorized by stature-related age (1-3, 4-6, 7-9, 10-12, and 13-15 years) and body region (head and face, neck, thorax, abdomen and pelvic content, thoracic and lumbar spine, upper extremities, pelvis, and lower extremities). The lower extremity category was further divided into three sub-structures (thigh, leg, and knee). For each age group and body region/sub-structure the proportion of casualties with at least one injury was then determined at given Abbreviated Injury Scale (AIS) severity levels. In addition, the average and distribution of the Maximum Abbreviated Injury Score (MAIS) and the average Injury Severity Score (ISS) were determined for each age group. The calculated proportions, averages, and distributions were then compared between age groups using appropriate significance tests. RESULTS: The overall outcome showed relatively minor variation between age groups, with the average +/- SD MAIS and ISS ranging from 2.3 +/- 0.9 to 2.5 +/- 1.0 and 8.2 +/- 7.2 to 9.4 +/- 8.9, respectively. The subjects in the 1- to 3-year-old age group were more likely to sustain injury to the head, face, and torso regions than the older subjects. The frequency of AIS 2+ lower extremity injury was approximately 20% in the 1- to 3-year-old group, but was twice as high in the 4- to 12-years age range and 2.5 times as high in the oldest age group. The frequency of femur fracture increased from 10% in the youngest group to 26% in the 4- to 6-year-old group and then declined to 14% in the 10- to 15-years age range. The frequency of tibia/fibula fracture increased monotonically with group age from 8% in the 1- to 3-year-old group to 31% in the 13- to 15-year-old group. CONCLUSIONS: While the overall outcome of child pedestrian casualties appears to be relatively constant across the pediatric stature range considered ( approximately 74-170 cm), subject height seems to affect the frequency of injury to individual body regions, including the thorax and lower extremities. This suggests that vehicle safety designers need not only account for the difference in injury patterns between adult and pediatric pedestrian casualties, but also for the variation within the pediatric group.     

地铁换乘车站客流疏运模拟及风险分析（1）-T型车站

地铁系统日常运行时承载着大规模客流,特别是地铁换乘车站,应对的是两条或者更多条线路客流的集聚和换乘,突发大客流容易造成运营安全事故。文章针对地铁客流疏运的宏观疏运组织和微观个体行为的耦合过程。分析提出了换乘车站大客流疏运风险分析的基本要素和步骤,并给出了疏运风险分析方法及需要关注的主要指标。基于智能个体和矢量空间模拟技术,建立了地铁大客流疏运模拟方法。结合某T型地铁换乘车站,对地铁换乘的客流运动过程进行了模拟仿真,分析了空间使用率、乘客滞留情况、空间人员瞬时密度、换乘时间和换乘距离等指标,辨识了客流高风险位置。文章提出的模拟方法和结论可为国内外类似车站制定客流组织方案及通道设计提供参考。     

钙钛矿型复合氧化物用于汽车尾气催化净化的研究进展(一)

综述了钙钛矿型汽车催化剂的研究进展.和过渡金属简单氧化物相比,钙钛矿型复合氧化物(ABO3)在热稳定性、化学稳定性和结构稳定性方面具有一定的优越性,因而表现出更高的催化活性.在满足容限因子的条件下,有多种元素可以形成钙钛矿结构的化合物.通常,B位离子决定了钙钛矿型化合物的催化活性,A位离子是影响化合物结构和B位离子价态的重要因素.当A位离子或B位离子被不同价态的离子取代时,通过形成氧离子空穴或者形成混合价态来保持化合物的电中性.氧空穴的形成或B位离子价态的变化使得化合物具有更高的活性.贵金属和钙钛矿型化合物结合,不仅可以有效防止贵金属的烧结,同时也提高了钙钛矿型化合物的催化活性.     

基于GM（1，N）灰模型预测企业主动性安全投入

本文基于GM（1,N）灰模型对企业主动性安全投入总量进行预测,研究把企业安全整体情况或整体表现作为一个“灰系统”对待时,依据该系统的特征量,来对企业主动性安全投入进行预测,为我国企业进行安全投入时提供决策依据。     

从南方雪灾谈我国应急管理的未来发展

2008年新年伊始,我国南方大部分地区出现了建国以来罕见的低温、雨雪和冰冻天气,给人民群众的生产、生活造成了极大的影响。这场灾害导致灾区基础设施遭受严重的破坏,对中国煤电油运的综合保障能力提出了严峻的挑战,打乱了社会经济的正常运行秩序。我们必须科学地认识此次灾害的性质与特点,认真汲取经验和教训,提高我国应急管理的能力和水平。     

优化GM(1,N)模型在交通噪声预测中的应用和精度分析

背景值是影响GM(1,N)模型模拟精度和预测精度的重要因素.传统灰色系统多因素GM (1,N)模型对背景值采用梯形法求积,误差较大.为了提高GM(1,N)模型的精度,基于数值分析中的逼近思想,采用数值积分中的Newton-Cores公式和Gauss-Legendre公式对背景值进行修正求积.理论分析表明该方法能够有效地提高模型的预测精度.然后将经过优化的GM(1,N)模型应用到城市道路交通噪声的预测上,模型预测值的平均误差从2.913％降低到了1.108％.应用实例表明优化后的GM(1,N)模型精度比原始GM(1,1)模型精度有较大提高,验证了该优化方法的实用性和有效性,且该方法为提高模型的预测精度提供了新的途径.     

Influence of new generic frequencies on the QRA calculations for land use planning purposes in Walloon region (Belgium)

In Europe, the article 12 of the “Seveso” Directive focuses on land use planning (LUP) around major hazard plants and imposes to keep a sufficient distance between a major hazard plant and populated areas. In Belgium, the LUP is treated at the regional level. The regional authority defines the policy and manages the LUP according to the quantified risk. The quantified external risk, around each Seveso company in the Walloon Region, is assessed by a unique technical expert, the Faculté Polytechnique de Mons, by means of a full probabilistic approach (QRA). This QRA methodology uses accident generic frequencies published by the Flemish Region (Aminal, 2004). In 2009-2010, the quantification of the external risk of the 90 walloon Seveso plants will be completed, based on this set of generic frequencies. However, the Flemish Region recently published a new set of generic frequencies (LNE, 2009), which, in some cases, are quite different of the previous ones for some equipment. This paper discusses the influence of the new frequency data on the quantified risk. An overview of the changes induced by the new set of data will be presented, as well as their impact on the already defined "consultation zones" in which decisions are made concerning the compatibility of the land use and the intensity of risk.     

煤矿事故预测的马尔可夫SCGM(1,1)c模型的建立与应用

煤矿安全是煤矿生产的重要保障,煤矿事故预测是煤矿安全评价和决策的基础。结合灰色SCGM(1,1)_c预测模型和马尔可夫链理论的优点,根据煤矿生产的特殊条件,提出了基于马尔可夫链的SCGM(1,1)_c预测模型。首先利用灰色SCGM(1,1)_c预测模型对我国1990—2010年的煤矿事故百万t死亡率进行初次预测,然后根据初次预测结果,利用残差模型对SCGM(1,1)_c模型预测结果进行修正。最后在修正模型的基础上,运用马尔可夫SCGM(1,1)_c模型对我国2011—2013年煤矿事故百万t死亡率进行了预测,并对两种模型的预测误差进行了对比分析。结果表明,马尔可夫SCGM(1,1)_c预测模型既能揭示煤矿事故百万t死亡率变化的总体趋势,又能克服随机波动性数据对预测精度的影响,具有较强的工程实用性。     

基于灰色系统GM(1,N)模型的高炉炉尘量的预测

应用灰色系统GM(1,N)模型对高炉冶炼时产生的炉尘量进行预报,以等维新息建模方式建模,同时结合GM(1,N)残差模型对预测值进行修正,以提高预测精度,使相对误差小于3％的命中率达到83．6％,给生产提供相关技术支持,以通过具体操作来达到固体废物减量化的目的。     

Fe2(SO4)3对稻秆和猪粪混合厌氧发酵产气的影响

为了探究不同剂量Fe_2(SO_4)_3对混合厌氧发酵产气的影响,以猪粪和稻秆为发酵原料,添加初始剂量分别为0.5%、1%、3%、6%、9%(基于发酵原料总固体质量)的Fe_2(SO_4)_3,采用中温((35±1)℃)厌氧发酵,发酵周期为30 d。结果表明,添加3%Fe_2(SO_4)_3处理总产气量和产甲烷量最高,相比对照分别提高了32.01%和51.48%;而Fe_2(SO_4)_3添加量过高会抑制产气,6%、9%添加量处理的总产气量相比对照分别降低了10.50%、11.73%。其中,9%的Fe_2(SO_4)_3添加组出现了挥发性脂肪酸(VFA)累积和发酵液p H值偏低的现象。对产气组分分析发现,不同添加量的Fe_2(SO_4)_3对N_2等主要气体含量影响无明显差异,但硫酸根的引入提高了各试验组沼气中的H_2S含量。通过对沼渣的XRD分析发现,铁源的添加促进了纤维素的分解,并刺激了体系中的硫与多种重金属元素生成矿物沉淀。     

A comparative study on the autoxidation of dimethyl ether (DME) comparison with diethyl ether (DEE) and diisopropyl ether (DIPE)

The Japanese government is planning to introduce DME as a substituted energy for oil and LNG. Introduction of DME could contribute greatly to both the prevention of global warming and the formation of resource-recycling societies. In these circumstances, a safety assessment of DME is very important when DME is used on a large scale. There is a possibility that prolonged exposure in air induces autoxidation to produce explosive organic peroxides during transportation and storage of DME. Therefore, the reactivity of DME with oxygen and the mechanism of the autoxidation were investigated. Accelerating Rate Calorimetry (ARC) was used to evaluate the thermal stability of DME and DIPE, a known peroxide producers, under adiabatic and various atmospheric conditions. In ARC studies of DME under oxygen, exothermic decompositions were detected although its self-heating rate was low in comparison with DIPE. Oven storage tests were carried out and iodimetry was used to measure the concentration of peroxides produced from DME in comparison with DIPE and DEE. However, no products could be found for DME either by GC/MS or by iodimetry, while some evidence of autoxidation of both DEE and DIPE were obtained from these experiments.     

聚叠氮缩水甘油醚嵌段聚叠氮乙酸乙烯酯的合成及热稳定性研究

以聚叠氮缩水甘油醚(GAP)和4,4'-偶氮(4-氰基戊酸)(ACVA)为原料合成大分子引发剂(MI-GAP),用其引发氯乙酸乙烯酯自由基聚合,得到聚叠氮缩水甘油醚嵌段聚氯乙酸乙烯酯(GAP-bPVCA),最后将其叠氮化得到含能聚合物——聚叠氮缩水甘油醚嵌段聚叠氮乙酸乙烯酯(GAP-b-PVAA)。采用傅里叶变换红外光谱(FT-IR)、紫外-可见光谱(UV-Vis)、核磁共振氢谱(1H NMR)对GAPb-PVAA的结构进行了表征。利用差热分析(DTA)、热重分析(TG)和微分热重分析(DTG)对GAP-b-PVAA的热稳定性进行了研究。结果表明,GAP-b-PVAA在空气中200℃未见分解;GAP-b-PVAA具有两个热失重过程,其中最大质量损失发生在228~243℃范围内,失重率为68.74%。GAP-b-PVAA热分解动力学参数由不同升温速率下的DTA表征数据,通过Kissinger方法和Ozawa方法计算得到,两种方法得到的表观活化能Ea数值相近,表明GAP-b-PVAA热稳定性良好,有望用于熔铸炸药中作为一种含能黏结剂。     

面包酵母菌对Pb2+和Cd2+单双重金属离子体系的吸附效果

为了探讨灭活面包酵母菌对Pb2+、Cd2+的单、双重金属离子体系(以下简称双离子体系)的吸附效果及影响机制,选择灭活面包酵母菌为吸附剂,对Pb2+、Cd2+的单离子体系和Pb2+-Cd2+双离子体系吸附动力学过程和等温吸附效果进行研究.结果表明,不同离子体系中,在相同初始浓度情况下,面包酵母菌对Pb2+的吸附量总是大于对Cd2+的吸附量.试验条件下,面包酵母菌对Pb2+、Cd2+的单离子体系和Pb2+-Cd2+双离子体系等温吸附符合Langmuir模型,最大吸附量qmax分别为0.414 9 mmol/g、0.346 8 mmol/g和0.488 5 mmol/g.SEM/EDS分析表明,Pb2+、Cd2+被吸附到菌体上,造成菌体变形或出现破裂,并使内部物质外泄,这可能是吸附进行一定时间后出现二次吸附过程的主要原因.灭活面包酵母对Pb2+和Cd2+具有良好的吸附效果,对Pb2+-Cd2+双离子体系的吸附,离子间的点位竞争和联合毒性作用是影响体系总体吸附效果的重要因素.     

Evaluative comparison of two methods for SADT determination (UN H.1 and H.4)

We present our results on the comparison of two methods for the SADT determination. Both methods, UN test H.1 and UN test H.4 are recommended by the international transport regulations from the UN. But during the last years the applicability of the UN test H.4 has been questioned for solid substances. Therefore, three organic peroxides and one self-reactive substance have been investigated in 5 kg and 20 kg packages as well as in the UN test H.4 in a 500 mL Dewar vessel. The SADT values determined with the different methods match. The UN test H.4 seems to be well suited for solid organic peroxides and self-reactive substances of at least 20 kg or 60 L.     

以DMCS为硅源的新型聚硅氯化铁铝的形态分布与混凝性能

采用二甲基二氯硅烷(DMCS)为硅源,与氯化铁、氯化铝聚合制备新型聚硅氯化铁铝絮凝剂(PAFSC).其形态分布和处理含藻水的混凝性能结果表明,该混凝剂的最优技术指标为nFe/nAl=0.4,nSi/n(Al Fe)=0.1,碱化度B=1.5,C(Al Fe):0.1 mol/L,pH=2.898,熟化时间为24h的条件下,有效成分Feb、Alb的含量最高,絮凝效果最好,PAFSc对浊度的净化效率可达98.6%.研究表明,二甲基二氯硅烷会产生很强的协同效应,使无机高分子絮凝剂PAFSC有效成分高,絮凝效果好.     

管道燃气火灾爆炸事故树分析(续)

4　预防事故的对策及安全检查表[1,2 ]从上述的求解可知 ,由于燃气火灾爆炸事故树比较复杂 :最小割集 1386 0组 ,最小径集为 2 4 3组。因而在制定燃气火灾、爆炸事故的预防措施时 ,应以最小径集为依据。根据最小径集的定义 ,只要事故树中的这些基本原因事件不发生 ,顶上事件就不会发生。综合考察所有 2 4 3组最小径集 ,要使燃气火灾、爆炸事故不发生 ,可以考虑下面 3个方案 :(1)杜绝Ｐ1的发生。要使Ｐ1不发生 ,则需使ｘ1不发生。(2 )杜绝Ｐ4的发生。要使Ｐ4不发生 ,则需使Ｐ4中的ｘ2 ,… ,ｘ14 ,ｘ16,ｘ17共 15个基本原因事件不发生。(3)杜…     

生物净化挥发性有机化合物(VOCs)的研究进展

有机废气中大多含有低浓度的苯、甲苯、苯乙烯、多环芳烃等挥发性有机化合物(VOCs)。这类挥发性有机化合物会对人体健康和生态环境造成危害。治理VOCs污染是大气污染治理的重要部分。生物法处理有机废气具有运行费用低、没有二次污染等优点。常用的生物处理技术主要有生物过滤池、生物滴滤池和生物洗涤塔。20世纪80年代生物法在欧洲得到快速发展,我国于90年代以后也开始了生物处理VOCs废气的研究,并取得了一定的成就。     

Cd和Cr(VI)单一及复合污染对鲫鱼组织过氧化物酶同工酶的影响

用聚丙烯酰胺凝胶电泳的方法研究了Cd和Cr(VI)的单一及复合污染对鲫鱼组织过氧化物酶(POD)同工酶的影响.结果表明,随着Cd、Cr(VI)中毒浓度的升高,Cd对肝POD同工酶起激活作用,对肾、脑则起抑制作用;Cr(VI)对肝POD同工酶和肾POD同工酶起激活作用,对脑POD同工酶影响不明显;Cd、Cr(VI)复合污染则均显示出协同效应的趋势.另外,Cd、Cr(VI)对鲫鱼主要器官POD同工酶的影响具有组织差异性.