Air bag effectiveness as function of impact speed

An investigation was conducted to estimate the effectiveness of air bags as a function of velocity. The study consisted of three parts: a theoretical idealization, an analysis of National Automotive Sampling System/Crashworthiness Data System (NASS/CDS), and a reanalysis of previously published Fatality Analysis Reporting System (FARS) data. The theoretical analysis looked at idealized risk curves as a function of velocity; assuming that the air bag offers a benefit for both belted and unbelted occupants. Analysis of the NASS/CDS data looked at the effectiveness of air bags as a function of velocity for Maximum Abbreviated Injury Scale (MAIS) 3+ injuries. The reanalysis of the previously published FARS data looked at the effectiveness of the air bag as a function of velocity for fatalities. The theoretical analysis indicates that the air bag effectiveness should be greatest at the low velocities. The field data analysis of both NASS/CDS and FARS were consistent with the theoretical analysis, indicating that air bags are most effective at the lower velocities, below 40 kph (25 mph), for both belted and unbelted occupants. Although it was not possible to estimate a different effect for belted and unbelted for fatalities using FARS, it was possible for MAIS 3+ using NASS/CDS. For unbelted occupants the effectiveness goes to zero or becomes negative above 40 kph (25 mph) for MAIS 3+, and for belted occupants the effectiveness stays positive but with significantly lower magnitude for speeds above 40 kph (25 mph).     

Benefit–cost analysis of lane departure warning and roll stability control in commercial vehicles

Introduction: This paper presents the cost benefits of two different onboard safety systems (OSS) installed on trucks as they operated during normal revenue deliveries. Using a formal economic analysis approach, the study quantified the costs and benefits associated with lane departure warning (LDW) systems and roll stability control (RSC) systems. Methods: The study used data collected from participating carriers (many of these crashes were not reported to state or Federal agencies), and the research team also reviewed each crash file to determine if the specific OSS would have mitigated or prevented the crash. The deployment of each OSS was anticipated to increase the safety of all road users, but impact different sectors of society in different ways. Benefits that were inherent in each group (e.g., industry, society) were considered, and different benefit–cost analyses (BCAs) were performed. Results: This paper presents two BCAs: a BCA focused on the costs and benefits in the carrier industry by implementing each OSS, and a BCA that measured the societal benefits of each OSS. In addition, a BCA for a theoretical mandatory deployment option for each OSS is presented. Conclusions: BCA results for LDW and RSC clearly showed their benefits outweighed their costs for the carrier and society. Practical applications: Cost information is a crucial factor in purchasing decisions in carriers; similarly, regulators must consider the cost burden prior to mandating technologies. The results in this study provide carrier decision makers and regulators with information necessary to make an informed decision regarding RSC and LDW.     

柴油环卫车电动化替代环境效益分析及可行性评估

以环卫车为研究对象,通过使用阶段柴油环卫车和电动环卫车污染排放强度对比,分析电动化替代所产生的环境效益。应用模糊数学模型方法从技术、经济、配套设施、污染减排效益方面,综合评估环卫车电动化替代可行性。结果表明:电动环卫车较柴油环卫车具有显著的减排效果,主要大气污染物排放可减少95.5%。影响柴油环卫车电动化替代的关键因素在电池动力性能、续航能力、经济成本和配套设施充电时长等方面。模糊数学模型的评估结果表明,50%柴油环卫车进行电动化替代是最佳方案,能较好地平衡经济性和大气环境保护的公共利益。未来提高电动化替代比例,还需依靠科技创新改进电动环卫车电池技术和动力等性能,降低购置成本,加强充电桩等配套基础设施的完善。     

人车碰撞中行人大腿保护研究

研究提高人车碰撞中行人大腿的保护性能的方法。首先对大腿伤害机理,伤害评价指标以及车辆自身结构进行阐述和研究,总结车辆前端结构的关键参数;对某车型的前大灯进行结构改进,按照欧洲新车安全评鉴协会(Euro NCAP)行人大腿保护的试验评价方法,改进后进行碰撞试验;建立装有发动机罩安全气囊的整车仿真模型,验证安全气囊对行人大腿的保护性能。经过试验和仿真可以得出:车辆前大灯结构刚度改进和发动机罩安全气囊可以改善行人大腿的保护性能。     

Railroad injury: Causes, costs, and comparisons with other transport modes

Safety regulators in the railroad industry need comprehensive injury costs by cause, and cost comparisons to other modes of transport to gain policy insights. This study links case-level data from the Federal Railroad Administration to monetary costs and consequences of specific injuries. Lost quality of life was estimated from physicians' ratings of injury impairment and the value of fatal risk reduction. Railroad injuries and illnesses cause an average of $3 billion in fatality costs and $650 million in nonfatal incident costs annually. Impacts at rail-highway crossings impose three times as much cost as the next highest cause. Commercial air travel is the safest per passenger mile. Trains, second lowest, have injury costs six times higher, but only one-fifth as high as cars. The relative safety of trains and airplanes in transport means highway modes enjoy implicit price subsidies. Better injury cost recovery through taxation or insurance would make the subsidies explicit. More informed modal choices and thus enhanced economic efficiency would result.     

Ergonomics and safety of manual bag sealing.

A variety of seals is used to close bags. Each seal has advantages and disadvantages. For shop assistants sealing bags could be a repetitive physically demanding action. Opening and closing the bags again can cause some discomfort or annoyance for consumers. Besides, it is an activity which can endanger safety, i.e., knives being used in opening, children swallowing the systems of sealing. To prevent these problems a new sealing system was developed. In this paper the opinion of shop assistants, consumers and experts on several bag sealing systems was studied. It appeared that for sealing plastic bags, adhesive tape with paper is the best out of 4 systems, closely followed by adhesive tape. It is discussed that for the elderly, there is still room for improvement in opening bag seals.     

滤筒式除尘器的改进及在白云石除尘中的应用

反吹风袋式除尘器存在运行阻力高、滤袋寿命短、排放浓度高等缺点.论述了利用改进滤筒、增设导流装置等一系列技术措施,提高滤筒式除尘器技术性能,从而用滤筒除尘技术对反吹风除尘器进行改造达到节能减排的效果.     

Thoracic Response and Trauma in Air Bag Deployment Tests with Out-of-Position Small Female Surrogates

The Hybrid III 5th percentile female dummy and seven small female cadavers were instrumented and tested as out-of-position drivers in static air bag deployment tests. Tank test pressure profiles were used to characterize inflator peak pressures and pressure onset rates of two production air bags and a prototype dual-stage system prior to their use in the static deployments. In the out-of-position tests, the chest of die surrogate was positioned in direct contact with the air bag module in an effort to create a worst-case loading environment for the thorax. For the cadavers, post-test radiographs and autopsy investigations identified rib fractures as the most common injury and showed that the number of fractures correlated well with maximum chest compression. The Viscous Criteria exceeded 1.0 m/s in nearly all dummy and cadaver tests but did not correlate well with the severity level of observed cadaver injury which was largely determined by hard-tissue rather than soft-tissue trauma. Statistical analysis of the injury, severity relative to the air bag and test parameters suggests that the pressure onset rate of the inflator is more important than peak pressure in determining the severity of out-of-position injuries and should be given primary consideration in inflator depowering efforts. Statistical comparison of dummy and cadaver responses indicates acceptable biofldelity of the Hybrid III small female dummy.     

Major accident management in the process industry: An expert tool called CESMA for intelligent allocation of prevention investments

A tool (called CESMA) was developed to carry out cost–benefit analyses and cost-effectiveness analyses of prevention investments for avoiding major accidents. A wide variety of parameters necessary to calculate both the costs of the considered preventive measures and the benefits related with the avoidance of accidents were identified in the research. The benefits are determined by estimating the difference in (hypothetical) major accident costs without and with the implementation of a preventive measure. As many relevant costs and benefits as possible were included into the tool, based on literature and expert opinion, in order to be able to deliver an all-embracing cost–benefit analysis and cost-effectiveness analysis to assist in the investment decision process. Because major accidents are related to extremely low frequencies, the tool takes the uncertainty of the unwanted occurrence of a major accident into account through the usage of a so-called ‘disproportion factor’. Compared with existing software, the CESMA tool is innovative by striving for an as-accurate-as-possible picture of costs and benefits of major accident prevention, and taking the uncertainties accompanying disastrous events into consideration. Furthermore, an illustrative example of CESMA is presented in the paper.     

Development of a mitigation system against hydrogen-air deflagrations in nuclear power plants

A novel mitigation system against hydrogen-air deflagrations in nuclear power plant buildings is proposed and developed through a series of field experiments using explosion vessels of different volume sizes. The mitigation system is installed on the outer surface of the vessels, and it comprises flame arrester and explosion air bag. The flame arrester is made by stacking 10–20 sheets of fine-mesh wire screens, and the air bag is connected for holding explosion gas. The successful mitigation mechanism is the sequence of pressure-rise reduction by the air bag expansion, flame quenching by the flame arrester, and the slow burning of the gas mixture sucked from the air bag back into the vessel due to the negative pressure caused by the rapid condensation of water vapor inside the vessel. Necessary conditions for the successful mitigation system are discussed, and the practical unit size of flame arrester sheet is recommended.     

How future trends in societal aging, air bag availability, seat belt use, and fleet composition will affect serious injury risk and occurrence in the United States

The objective of this study was to quantify the importance of societal aging relative to other factors that are known to affect injury risk. An aging population's effect on Maximum Abbreviated Injury Scale (MAIS) 3+ injury trends for passenger car drivers in frontal crashes was projected and compared to the effects of projected changes in fleet composition, changes in seat belt usage, and changes in air bag availability. It was determined that increased frailty due to an aging population will result in 19,816 to 43,568 additional injuries to passenger car drivers in frontal crashes from 1996 to 2012. Aging was shown to have an effect similar to the increased presence of light trucks in the fleet (a cumulative increase of approximately 47,428 injuries). Aging and changing fleet composition were shown to have a smaller effect than the projected increases in seat belt use or air bag availability, though the effect of increased belt use is not much greater than the effect of aging. After 2012, however, air bag availability and seat belt use will plateau, while societal aging will continue.     

Potential effects of lowering the BAC limit on injuries,fatalities, and costs

IntroductionPotential health and cost impacts of lowering the BAC limit for U.S. drivers below .08% were explored through analyses of reductions in crash incidence, injury severity, and costs based on five scenarios with varying assumptions about how the change to a .05% BAC limit might affect alcohol-impaired driving.MethodsDistribution of crashes by injury level and highest driver or non-occupant BAC levels for 2010, together with unit crash costs provided a base for comparison. Scenario 1 assumed all alcohol-impaired driving ceased; scenario 2 assumed all drivers obeyed the law, and scenario 3 assumed decreases in driver BAC levels would be limited to those who had been driving near the legal limit before the change. Scenario 4 was based on changes in driver BAC levels associated with a 08% to .05% BAC limit change in Australia, and scenario 5 was based on changes in alcohol-related crashes associated with the change to the .08% BAC limit in the United States. The number of casualties prevented in each scenario was estimated using relative risks of crash involvement, and changes in societal costs were estimated using the unit costs.ResultsReductions ranging from 71% to 99% in fatalities, injuries, and costs related to alcohol-impaired driving were estimated in scenarios 1 and 2. Scenarios 3–5 produced smaller reductions ranging from 4% to 16% for alcohol-impaired fatalities, injuries, and costs.ConclusionThe wide difference between the outcomes of the two sets of scenarios reflects the sensitivity of BAC policy benefits to driver compliance behavior.Practical applicationThe quantification of the reduction in the number and costs of traffic crash casualties in the set of behavioral scenarios explored in this research can inform policymakers about the extent and limits of benefits achievable by lowering the BAC limits as they consider strategies to reduce alcohol-impaired driving.     

Fewer workers' compensation claims and lower claim costs if employers with high injury rates achieved the rates of their safer peers

Introduction: Employers engaged in similar business activities demonstrate a range of workers' compensation claim rates. Workplace injuries and illnesses could be prevented if employers with high claim rates achieved the claim rates of their safer peers. Methods: We used Washington workers' compensation claims data for years 2013–2015 to calculate rates of compensable claims (eligible for disability or time loss benefits, if unable to work four days after injury) and total accepted claims (compensable plus medical-aid only claims) for each employer. We estimated the number and cost of claims to occur if employers with high claim rates reduced them to the rates of employers at the 25th percentile, adjusted for insurance risk class, employer size, and injury type. To evaluate the impact of setting more or less ambitious goals, we also estimated reductions based on claim rates at the 10th and 50th percentiles. Results: Over 43% of claims and claim costs would be prevented if employers with higher claim rates lowered them to the 25th percentile using either total accepted or compensable claim rates as the benchmark outcome. The estimated claim cost savings from benchmarking to compensable claims was nearly as great as the estimate based on benchmarking to total accepted claims ($308.5 mil annually based on compensable claims vs. $332.4 mil based on total accepted claims). Restaurants and Taverns had the greatest number of potentially prevented compensable claims. Colleges and Universities and Wood Frame and Building Construction had the greatest potential reduction in compensable claim costs among larger and smaller employers, respectively. Conclusion: Substantial reductions in workers' compensation claims and costs are possible if employers achieve the injury rates experienced by their safer peers. Practical application: Evaluating the range of workplace injury rates among employers within industry groups identifies opportunities for injury prevention and offers another approach to resource allocation.     

Assessment of Integrated Pedestrian Protection Systems with Autonomous Emergency Braking (AEB) and Passive Safety Components

Objective: Autonomous emergency braking (AEB) systems fitted to cars for pedestrians have been predicted to offer substantial benefit. On this basis, consumer rating programs—for example, the European New Car Assessment Programme (Euro NCAP)—are developing rating schemes to encourage fitment of these systems. One of the questions that needs to be answered to do this fully is how the assessment of the speed reduction offered by the AEB is integrated with the current assessment of the passive safety for mitigation of pedestrian injury. Ideally, this should be done on a benefit-related basis.

The objective of this research was to develop a benefit-based methodology for assessment of integrated pedestrian protection systems with AEB and passive safety components. The method should include weighting procedures to ensure that it represents injury patterns from accident data and replicates an independently estimated benefit of AEB.

Methods: A methodology has been developed to calculate the expected societal cost of pedestrian injuries, assuming that all pedestrians in the target population (i.e., pedestrians impacted by the front of a passenger car) are impacted by the car being assessed, taking into account the impact speed reduction offered by the car's AEB (if fitted) and the passive safety protection offered by the car's frontal structure. For rating purposes, the cost for the assessed car is normalized by comparing it to the cost calculated for a reference car.

The speed reductions measured in AEB tests are used to determine the speed at which each pedestrian in the target population will be impacted. Injury probabilities for each impact are then calculated using the results from Euro NCAP pedestrian impactor tests and injury risk curves. These injury probabilities are converted into cost using “harm”-type costs for the body regions tested. These costs are weighted and summed. Weighting factors were determined using accident data from Germany and Great Britain and an independently estimated AEB benefit. German and Great Britain versions of the methodology are available. The methodology was used to assess cars with good, average, and poor Euro NCAP pedestrian ratings, in combination with a current AEB system. The fitment of a hypothetical A-pillar airbag was also investigated.

Results: It was found that the decrease in casualty injury cost achieved by fitting an AEB system was approximately equivalent to that achieved by increasing the passive safety rating from poor to average. Because the assessment was influenced strongly by the level of head protection offered in the scuttle and windscreen area, a hypothetical A-pillar airbag showed high potential to reduce overall casualty cost.

Conclusions: A benefit-based methodology for assessment of integrated pedestrian protection systems with AEB has been developed and tested. It uses input from AEB tests and Euro NCAP passive safety tests to give an integrated assessment of the system performance, which includes consideration of effects such as the change in head impact location caused by the impact speed reduction given by the AEB.     

Dust collector explosions: A quantitative hazard evaluation method

A methodology is presented to evaluate the explosion hazard of typical bag and cartridge dust collectors. The evaluation accounts for the expected development of suspended dust concentrations greater than the dust MEC during the normal pulsing of the bags or cartridges to remove part of the attached dust. Equations are presented to calculate these concentrations and also the associated partial volume explosion pressures resulting from the ignition of these dust clouds. Five quantitative examples are presented. The methodology also includes considerations of potential upset condition full volume explosions associated with the detachment of about half the dust on the bags or cartridges. A flow chart is offered to implement this hazard evaluation method for special situations in which the need for dust explosion protection may not be obvious.     

On-board safety monitoring systems for driving: review, knowledge gaps, and framework

IntroductionFatal highway incidents remain the leading type of fatal work-related event, carrying tremendous personal, social, and economic costs. While employers with a fixed worksite can observe and interact directly with workers in an effort to promote safety and reduce risk, employers with workers who operate a motor vehicle as part of their job have fewer options. New technologies such as on-board safety monitoring systems offer the potential to further improve safety. These technologies allow vehicle owners to collect safety-specific information related to a driver's on-the-road behavior and performance. While many such devices are being developed and implemented in both commercial fleets and private vehicles, the scientific examination of these devices has lagged by comparison.MethodIn the current paper, we: (a) describe the general features and functionality of current generations of on-board monitoring devices and how they might impact various driver behaviors; (b) review the current state of scientific knowledge specific to on-board devices; (c) discuss knowledge gaps and potential areas for future research, borrowing from the related domain of computer-based electronic performance monitoring (EPM); and (d) propose a framework that can be used to explore some of the human-system interactions pertaining to monitoring systems.Impact on IndustryMotor vehicle crashes can carry tremendous costs for employers, in terms of injury, disability, and loss of potentially productive work years. New technologies can offer tremendous benefits in terms of promoting safer on-the-road behaviors.     

某卷烟厂卷接机组集中风力与除尘系统的应用

结合贵州某卷烟厂技术改造实践，采用集中工艺风力和除尘技术，对PASSIM和SUPER9卷接机组的工艺风力供给方式和除尘系统进行了改进。对于系统的结构、可靠性、调节性、稳定性进行了分析，改造后集中风力系统较常规风力系统在经济效益和工作环境上具有显著优势，降低了运行成本。     

Strategic accident reduction in an energy company and its resulting financial benefits

This study provides a case example of an energy company that prioritized occupational safety and health and accident reduction as long-term, strategic development targets. Furthermore, this study describes the monetary benefits of this strategic decision. Company-specific accident indicators and monetary costs and benefits are evaluated. During the observation period (2010–2016), strategic investments in occupational safety and health cost the company EUR 0.8 million. However, EUR 1.8 million were saved in the same period, resulting in a 2.20 cost–benefit ratio. The trend in cost savings is strongly positive. Annual accident costs were EUR 0.4 million lower in 2016 compared to costs in 2010. This study demonstrates that long-term, strategic commitment to occupational safety and health provides monetary value.     

袋式除尘器滤袋接缝方法对PM_(2.5)过滤效率的影响

针对袋式除尘器超低排放及对PM_(2.5)细颗粒物的捕集控制问题,选用分别经缝合、热熔两种制袋工艺制作的滤袋进行试验,探讨不同袋身接缝方法对袋式除尘器滤袋PM_(2.5)过滤效率的影响。结果表明:1 m/min过滤风速时,清洁状态下热熔滤袋对PM_(2.5)的过滤效率要比缝合滤袋高12.59%,而集尘状态下随滤袋表面粉尘负荷的不同,热熔滤袋对PM_(2.5)的过滤效率要比缝合滤袋高8.68%~11.18%;随过滤风速增加,缝合滤袋对PM_(2.5)过滤效率的衰减幅度要远大于热熔滤袋;滤袋表面尘饼的形成和分布的均匀性是缩小缝合滤袋与热熔滤袋间过滤效率差距的重要因素。     

烧结机尾“电改袋”除尘器数值模拟

针对现有"电改袋"除尘器不易实现在运行中更换滤袋且内部气流分布不均匀等问题,结合某烧结厂190 m2"电改袋"工程实例,提出一种可以在运行中更换滤袋的分室式"电改袋"除尘器结构,并利用CFX软件模拟其流场。结果表明,烟气由进气烟道进入袋室时速度大小和方向均发生突变,大颗粒粉尘受惯性力和重力作用易被中间灰斗捕集,有效减缓粉尘对滤袋的磨损;滤袋底部附近区域和两侧灰斗内的烟气速度分别小于5 m/s和6 m/s,可有效防止滤袋间的碰撞磨损和灰斗二次扬尘;各袋室的烟气流量分布比较均匀,标准差为0.152。