Mitigation performance of the process protection system on the accident consequences of H2S-containing natural gas release and explosion

Toxic loads and explosion overpressure loads pose grave threats to the offshore oil and gas industry. Many safety measures are adopted to prevent and mitigate the adverse impacts caused by toxic loads and explosion overpressure loads. As a general safety barrier, the process protection system has been widely used but rarely evaluated. In order to assess the barrier ability, the mitigation performance of the process protection system is concerned in this study. Firstly, several chain accidents of H₂S-containing natural gas leakage and explosion are simulated by varying the response time of the process protection system with CFD code FLACS. Qualitative assessment is conducted based on the variation of the dangerous load profiles. Furthermore, the quantitative assessment of the mitigation performance is accomplished by considering its ability in reducing the probability of fatality. Emergency evacuation and no emergency evacuation are considered respectively in the quantitative assessment. The results prove that the process protection system takes effect on mitigating the toxic impact and explosion overpressure impact. The results also demonstrate that although the emergency evacuation may result in a severer explosion load to the operator, the process protection system can mitigate the adverse impacts regardless of whether the emergency evacuation is conducted or not.     

BLEVE: A new approach to the superheat limit temperature

Several methods proposed for calculating the value of the superheat limit temperature were analysed. The results obtained indicate that the procedures based on the thermodynamic stability approach introduce a significant uncertainty into the final values, depending on which equation of state is used. We propose a new approach based on the energy balance in the initial liquid mass just before the explosion. The temperature obtained using this method, T_sl−E, corresponds to the situation in which the energy transferred adiabatically between the cooling liquid and the vaporising liquid fractions is at its maximum. This leads to a minimum content of energy in the remaining liquid. Although these two approaches are equivalent—the procedures based on the thermodynamic stability approach use also the minimum energy state as a criterion—the new proposed method only uses the properties of the substance to obtain T_sl−E. Thus, T_sl−E represents the behaviour of each substance as a function of its molecular structure, while this influence is lost if a simple equation of state is used. Finally, some considerations are made on the limitations of the superheat limit temperature as a criterion for establishing whether an explosion is or is not a BLEVE.     

Methods of Assessing Efficiency of UV-Protecting Products

A few aspects of skin protection against ultraviolet (UV) light and methods of assessing efficacy of UV-protecting cream or gels have been discussed. UV-protection in cream and gels is not only a strategy of the cosmetic industry but a necessity because of human occupational activity and daily habits.     

基于人体皮肤热模型的热防护服评价方法研究

在热防护服热防护性能测试装置基础上,用自行研制的新型耐高温模拟皮肤传感器代替铜片热流计测量通过应急热防护服装面料的热流量,将热流量作为热波皮肤模型边界条件,得到人体皮肤表层下80μm处的温度值,从而得到一定条件下人体真实皮肤达到二级烧伤所需时间,用其评价热防护服用织物的热防护性能,并将热波皮肤模型(TWMBT)的测试值与Pennes模型以及铜片热流计的测试结果进行分析比较。采用热波皮肤模型分析织物层下的"皮肤"防热时间更接近实际皮肤达到二级烧伤时间值,可较为精确的量化织物热防护性能,为应急救援热防护服装的热设计提供理论依据。     

Application of machine learning technique for optimizing roadside design to decrease barrier crash costs,a quantile regression model approach

Introduction: In-transport vehicles often leave the travel lane and encroach onto natural objects on the roadsides. These types of crashes are called run-off the road crashes (ROR). Such crashes accounts for a significant proportion of fatalities and severe crashes. Roadside barrier installation would be warranted if they could reduce the severity of these types of crashes. However, roadside barriers still account for a significant proportion of severe crashes in Wyoming. The impact of the crash severity would be higher if barriers are poorly designed, which could result in override or underride barrier crashes. Several studies have been conducted to identify optimum values of barrier height. However, limited studies have investigated the monetary benefit associated with adjusting the barrier heights to the optimal values. In addition, few studies have been conducted to model barrier crash cost. This is because the crash cost is a heavily skewed distribution, and well-known distributions such as linear or poison models are incapable of capturing the distribution. A semi-parametric distribution such as asymmetric Laplace distribution can be used to account for this type of sparse distribution. Method: Interaction between different predictors were considered in the analysis. Also, to account for exposure effects across various barriers, barrier lengths and traffic volumes were incorporated in the models. This study is conducted by using a novel machine-learning-based cost-benefit optimization to provide an efficient guideline for decision makers. This method was used for predicting barrier crash costs without barrier enhancement. Subsequently the benefit was obtained by optimizing traffic barrier height and recalculating the benefit and cost. The trained model was used for crash cost prediction on barriers with and without crashes. Results: The results of optimization clearly demonstrated the benefit of optimizing the heights of road barriers around the state. Practical Applications: The findings can be utilized by the Wyoming Department of Transportation (WYDOT) to determine the heights of which barriers should be optimized first. Other states can follow the procedure described in this paper to upgrade their roadside barriers.     

Skin reactions to latex in dental professionals – first Croatian data

Purpose. To determine the prevalence of undesirable skin reactions to latex in dental professionals and students of the School of Dental Medicine in Zagreb, Croatia. Methods. Our research included 444 participants, of which 200 agreed to undergo a skin prick test (SPT). All participants answered a questionnaire in which we asked about incidence of skin lesions, duration of occupational exposure to latex, localization of skin lesions and symptoms. Statistical analysis of the questionnaire and test results was then carried out. Results. Of the total 444 participants surveyed, 249 (56.1%) reported lesions on their skin (professionals 64.8%, students 6.1–58.5%). From the questionnaire, 239 (96.0%) respondents reported lesions on the hands and fingers, mostly in the form of erythema (37.0%) and occasional dryness of skin (29.0%). Positive SPT results were found in 14 (7.0%) out of the 200 respondents who underwent the test. Conclusions. While a large number of subjects (56.1%) reported skin lesions when using latex products at their workplace, the SPT test was positive only in 7.0%. The results show that the prevalence of self-reported skin lesions was significantly related to the length of occupational exposure, with a substantial effect size (p?<?0.001; V?=?0.334).     

外军皮肤防护器材化学防护性能测试与评价用标准物质研究进展

本文简迷了皮肤防护器材--化学防护服(衣)化学防护性能试验与评价用标准物质的重要性,系统地概述了外军化学防护服(衣)化学防护性能试验与评价用标准物质的研究现状,并提出了我国化学防护服(衣)防护性能试验与评价用标准物质研制过程中应注意的一些问题.     

Examining crash injury severity and barrier-hit outcomes from cable barriers and strong-post guardrails on Alabama’s interstate highways

Introduction: This study investigates the impact of several risk factors (i.e., roadway, driver, vehicle, environmental, and barrier-specific characteristics) on the injury severity resulting from barrier-related crashes and also on barrier-hit outcomes (i.e., vehicle containment, vehicle redirection, and barrier penetration). A total of 1,685 barrier-related crashes, which occurred on three major interstate highways (I-65, I-85, and I-20) in the state of Alabama, were collected for a seven-year period (2010–2016), and all relevant information from the police reports was reviewed. Features that were rarely explored before (e.g., median width, barrier length, barrier offset or lateral position, left shoulder width, blockout type, and number of cables) were also collected and examined. Two types of longitudinal barriers were analyzed: high-tension cable barriers installed on medians and strong-post guardrails installed on medians and/or roadsides. Method: Two separate mixed logit (MXL) models were used to analyze crash injury severity in median and roadside barrier-related crashes. Two additional MXL models were separately adopted for median and roadside barrier-related crashes to estimate the probability of three barrier-hit outcomes (vehicle containment, vehicle redirection, and barrier penetration). Results: The results of crash injury severity MXL models showed that, for both median and roadside barrier crashes, barrier penetration, female drivers, and driver fatigue were associated with a higher probability of injury or fatal crashes. The results of barrier-hit MXL models showed that longer barrier length, Brifen cable barrier system, and barrier lateral position were significant predictors of median barrier-hit outcomes, whereas dark lighting condition, driving under the influence (DUI), presence of curved freeway sections, and right shoulder width significantly contributed to roadside barrier-hit outcomes. Conclusions: The MXL model succeeded in identifying several contributing factors of crash severity and barrier-hit outcomes along Alabama’s interstate highways. Practical applications: One study application is to design longer barrier run length (greater than 1230 feet or 0.2 miles) to reduce the barrier penetration likelihood.     

Non-equilibrium phenomena in carbon dioxide expansion

Release of liquid and supercritical carbon dioxide is a fundamental research topic in CCS. Traditional approach is largely based on HEM and, in general, assumes equilibrium from the outlet to the Mach disc. Experimental results have shown that this approach is not always effective in describing the expansion phenomenon; therefore a significant lack of knowledge exists about CO₂ properties at the under-expanded jet zone boundary, which is a main focus in process safety. Here, solid formation, vapour quality, sonic velocity and final temperature are generally calculated according to equilibrium saturation condition, and this is generally incorrect. This article deals with non-equilibrium thermodynamics of liquid and supercritical CO₂ expansion, illustrating relaxation dynamics through the HRM models, and discussing the very specific singularities of CO₂ phase transitions, vapour to liquid and liquid to solid, that result away from the equilibrium condition, due to the rapid phase changes and to the specific properties of CO₂ multi phase thermodynamics, including nucleation and particle growth. Statistical rate theory has been applied with the aim at identifying the phase transition energy barrier, resulting in a significant entropy increase. A case study based on HEM conservation equations integrated with the statistical rate approach has been presented, which covers the gap of the equilibrium hypothesis. The objective of the article is to provide a more accurate method to predict the properties of carbon dioxide following an expansion.     

Examination of the severity of two-lane highway traffic barrier crashes using the mixed logit model

IntroductionVehicles in transport sometimes leave the travel lane and encroach onto natural or artificial objects on the roadsides. These types of crashes are called run-off the road crashes, which account for a large proportion of fatalities and severe crashes to vehicle occupants. In the United States, there are about one million such crashes, with roadside features leading to one third of all road fatalities. Traffic barriers could be installed to keep vehicles on the roadways and to prevent vehicles from colliding with obstacles such as trees, boulder, and walls. The installation of traffic barriers would be warranted if the severity of colliding with the barrier would be less severe than colliding with other fix objects on the sides of the roadway. However, injuries and fatalities do occur when vehicle collide with traffic barriers. A comprehensive analysis of traffic barrier features is lacking due to the absence of traffic barrier features data. Previous research has focused on simulation studies or only a general evaluation of traffic barriers, without accounting for different traffic barrier features.MethodThis study is conducted using an extensive traffic barrier features database for the purpose of investigating the impact of different environmental and traffic barrier geometry on this type of crash severity. This study only included data related to two-lane undivided roadway systems, which did not involve median barrier crashes. Crash severity is modeled using a mixed binary logistic regression model in which some parameters are fixed and some are random.ResultsThe results indicated that the effects of traffic barrier height, traffic barrier offset, and shoulder width should not be separated, but rather considered as interactions that impact crash severity. Rollover, side slope height, alcohol involvement, road surface conditions, and posted speed limit are some factors that also impact the severity of these crashes. The effects of gender, truck traffic count, and time of a day were found to be best modeled with random parameters in this study. The effects of these risk factors are discussed in this paper.Practical applicationsResults from this study could provide new guidelines for the design of traffic barriers based upon the identified roadway and traffic barrier characteristics.     

Abstracts

Cancer mortality of art glass workers in Tuscany, Italy. R. Pirastu, D. Bartoli, G. Battista, M. DeSantis, T. Iaia, D. Orsi, M. Tarchi, M. Valiani. Scand J Work Environ Health, 24(5): 386-391.Objectives: This study considers the cause-specific mortality from cancer among art glass workers employed in 17 industrial facilities in Tuscany, Italy.Methods: A cohort of 3390 workers, 3180 men and 210 women, employed at least 1 year, was taken from December 1993. The cause-specific expected mortality from cancer was computed for men relative to Tuscany rates, specified for gender, 5-year age groups, and calendar year. Separate analyses were carried out for the job title of maker and former and for batch mixers.Results: For 3180 men, the observed mortality was above the expected for larynx [standardized mortality ratio (SMR) 166, 90% confidence interval (90% CI) 90 —282], lung (SMR 123, 90% CI 100—151), stomach (SMR 105, 90% CI 76 —142), and brain (SMR 150, 90% CI 71—282) cancer. Increases for these causes were also found for the makers and formers. Mortality from larynx and lung cancer increased with latency, and significantly increased SMR values were observed for ≥21 years since first exposure. The increasing pattern was also present after adjustment for smoking.Conclusions: The results showed consistently increased mortality from larynx and lung cancer in the overall cohort and among makers and formers. Stomach and brain cancer was also increased in the overall cohort and among the makers and formers.Occupational skin and respiratory diseases among hairdressers. T. Leino, L. Tammilehto, M. Hytönen, E. Sala, H. Paakkulainen, L. Kanerva. Scand J Work Environ Health, Vol. 24, No. 5, 398-406.Objectives: The occurrrence and causes of hairdressers' occupational skin and respiratory diseases were studied.Methods: Of a random sample of 500 female hairdressers aged 15-54 years, 355 were available for study. Of the 189 reporting work-related skin and respiratory symptoms in a computer-aided telephone interview on exposure and health, 130 underwent a physical examination, lung funtion tests, prick and patch testing, and nasal and lung provocation tests. An occupational disease was diagnosed when the causality between exposure and disease was probable and the clinical tests supported the diagnosis.Results: The telephone interview revealed a life-time prevalence of 16.9% for hand dermatoses, 16.9% for allergic rhinitis, and 4.5% for asthma among the hairdressers. In the clinical investigations, the prevalence was 2.8% for occupational dermatoses, 1.7% for occupational rhinitis, and 0.8% for occupational asthma. Ammonium perfulfate caused 90% of the respiratory diseases and 27% of the hand dermatoses. Paraphenylenediamine, natural rubber latex, and skin irritation were also causes of hand dermatitis. Allergy to human dandruff (8.6%) and Pityrosporum ovale (12.2%) was common. Previously diagnosed atopic diseases increased the risk for occupational skin or respiratory disease 3-fold (odds ratio 2.9, 95% confidence interval 1.1—7.9). Of the cases, 37.5% (6 of 16 persons) had to change occupations during a 3-year follow-up.Conclusions: Work-related skin and respiratory symptoms are common among hairdressers. Often a specific cause (e.g., ammonium persulfate) can be found if occupational diseases are suspected and diagnosed. Hairdressers with atopic diseases are at risk of developing occupational skin and respiratory diseases.Job demands, muscle activity and musculoskeletal symptoms in relation to work with the computer mouse. C. Jensen, V. Borg, L. Finsen, K. Hansen, B. Juul-Kristensen, H. Christensen. Scand J Work Environ Health, Vol. 24, No. 5, 418-424.Objectives: This study assessed work postures, movements, psychosocial job demands, and shoulder and wrist extensor muscle activity and registered the prevalence of musculoskeletal symptoms of computer-aided design (CAD) operators.Methods: A questionnaire survey was used to study the use of the computer mouse, psychosocial work factors, and musculoskeletal symptoms among 149 CAD operators. A workplace study was performed using observations electrogoniometers on the wrists, and electromyography to measure exposures and physiological responses during CAD work among a subgroup of the CAD operators.Results: Musculoskeletal symptoms were far more prevalent for the arm or hand operating the mouse than for the other arm or hand, and women were more affected than men. The symptoms may be related to such risk factors as repetitive movements, static postures (e.g., ulnar-deviated and extended wrist on the mouse side), and static muscular activation patterns. The risk factors were present due to continuous mouse use and possible also due to high demands for mental attentiveness, precision, and information processing.Conclusions: Exposure during work with a computer mouse may present a risk for devloping musculoskeletal symptoms. Improvements should focus on introducing more variation.Driver behavior at rail-highway crossings. J. Abraham, T. Datta, & S. Datta. Transportation Research Record, 1648. Paper No. 98-0632.A study of driver behavior at 37 rail-highway crossings in Michigan revealed the possible associations between past crash histories and violations. Data collection included recording license plate numbers for violating vehicles, driver gender, approximate age of the driver, and the vehicle make and model. Driver violations were categorized into five different levels of severity ranging from routine to critical. The 37 study sites were subdivided into four groups based on crossing geometry and traffic control. The number of sites in the groups ranged from 5 to 18. Seven years of crash data on the study sites were considered for significance testing. Observed violation data for the same groups were calculated, and tests for statistical significance were performed on them. The results of this study indicated promise for the use of the violation data in determining the relative hazardousness of rail-highway crossings in combination with crash histories. The violation data may also be used to develop countermeasures that would help alleviate violations and eventually traffic crash problems at rail-highway crossing sites. Targeted enforcement as well should assist in driver behavioral modifications. Additionally, the timely arrival of trains after the warning devices are triggered is an essential element that motorists assess when considering taking risks.Airbags: an exploratory survey of public knowledge and attitudes. T. Nelson, D. Sussman, J. Graham. Accident Analysis and Prevention, 31(4), 371-379.The present study examines public knowledge and opinion in the United States on issues related to airbag safety. Data were obtained through a national random digit-dial telephone survey of 1005 people living in the contiguous 48 United States. A majority of respondents (1) know that airbags can harm drivers seated too close to the steering wheel; (2) know that rear-facing infant seats should not be placed in the front seat of a car with passenger-side airbags; and (3) know that airbags are saving more lives of women drivers than are being lost. However, most respondents did not know the (1) airbags are killing more children than they are saving; (2) airbags can injure properly belted drivers; and (3) the majority of the lives saved by airbags have been among people who were not wearing safety belts. Knowledge of airbag risks to children and properly belted drivers was significantly associated with a less favorable attitude toward airbags, and with opposition toward the law mandating airbags on all new cars. Drivers of vehicles equipped with airbags held more favorable attitudes toward airbag technology. Further analysis suggest that as the public begins to understand the risks associated with airbags, the current high level of public support for the technology and the mandatory regulation may decline.The relationship of traffic accidents with personality traits. B. Alparslan, C. Dereboy, S. Savk, H. Kaynak, I. Dereboy, E. Cullu, I. Ozkan, S. Ayaz. J. Traffic Me 27(1-2), 25-30.Objective: This study aims to compare traffic accident involved drivers with non-involved drivers in terms of various personality traits and socioeconomic variables.Methods: Ninety-eight drivers consecutively involved in motor accidents within the first four months of 1997 comprised the study group, whereas 88 non-involved drivers served as the control group. The self-report inventory of SCID-II (Structural Clinical Interview for DSM-III-R) was administered to each subject. In addition, we collected data representing the subjects' sociodemographic characteristics, driving experience, and driver license types.Results: No significant difference was found between the two groups in terms of age, socioeconomic level, marital status, and driving experience. In contrast, there were more males and heavy vehicle drivers in the accident group as compared with the control group. In addition, the accident group received significantly higher scores in half of the SCID-II personality scales, namely, schizotypal, histrionic, borderline, antisocial, dependent and passive-aggressive.Conclusions: Our findings suggest that the accident involved drivers as a group display asocial behaviors, difficulty in impulse control, alertness and aggressive behaviors.Snowboarder's wrist: Its severity compared with Alpine skiing. K. Sasaki, M. Takagi, Y. Kiyoshige, T. Ogino. The Journal of Trauma: Injury, Infection, and Critical Care. 46(6), 1059-1061.Background: Although the upper extremity, especially the wrist, has been reported to be the most commonly injured site in snowboarding, the severity of these injuries is still unknown. The purpose of this study is to compare the severity of wrist injuries in snowboarding with those in alpine skiing for insight into the treatment of snowboarder's wrist.Materials and methods: The cases of 11,598 patient injured while snowboarding and skiing who presented to the Zao clinic during the past 7 seasons were reviewed and compared. Demographics were studied, focusing on fractures around the wrist joint. Roentgenographically precise assessment of the distal radial fracture was performed according to AO classification.Results: Snowboarders were more likely to injure the wrist than were skiers (18.7% vs. 2.5%, p < 0.01). In the wrist injuries, distal radial fractures occurred at a rate of 0.28 per 1000 snowboarders and 0.008 per 1000 skiers. Comminuted and articular fractures classified as AO type A3, B and C, which required surgical treatment, were 49.4% of distal radial fractures in snowboarders and 23.8% in skiers.Conclusion: Wrist injury sustained while snowboarding is characterized as a severe and complex injury. Thus, we call attention to its severity in the treatment of snowboarder's wrist.Children's fractures: a population based study. R.A. Lyons, A.M. Delahunty, D. Kraus, M. Heaven, M. McCabe, H. Allen, P. Nash. Injury Prevention, 5(2), 129-132.Objective: To measure the incidence of childhood fractures in a defined population.Setting: Accident and emergency (A & E) departments covering the Swansea and North Port Talbot areas of South Wales in 1996.Methods: Linkage of data from A & E departments with population data to produce fracture incidence rates by anatomical site and cause in children aged 0-14 years.Results: During 1996, 2463 new fractures occurred in 2399 residents yielding a fracture rate of 35.1/1000 children. Fractures were more common in boys than girls and increased with age in both groups. Sports and leisure activities accounted for 36% of fractures, assaults for 3.5%, and road traffic accidents 1.4%. Fractures of the radius/ulna were most frequent (36%).Conclusions: The fracture rate in South Wales children is twice the rate reported in previous studies. Further research is required to elucidate the reasons behind this high rate. Many fractures could be prevented by the use of safer surfaces in school playgrounds, and wrist protection in in-line skaters and possibly in soccer players.Elevator Accidents. P. Magnus. Elevator World, 47(6), 112-115.The compilation and analysis of accident data involving elevators is of great importance in efforts to eliminate or at least reduce such accidents. The data can clearly show what priorities should be set. This article analyzes the accident data for Israel during a 23-year period (1975-1998), and the results show that the dominant cause for these accidents was the “absence of a car door.” This led to a regulatory demand to install car doors retroactively. The second dominant cause was “falling into the elevator shaft,” stressing the importance of inspection and maintenance of the door locks. Furthermore, the data point to the need to train elevator technicians on a periodic basis to emphasize the importance of correct and safe work methods, for their own good and for the benefit of the passengers. The intervention of untrained and unauthorized personnel is dangerous and must be forbidden. This should be enforced vigorously.     

A framework for definition of logical scenarios for safety assurance of automated driving

Abstract

Objective: In order to introduce automated vehicles on public roads, it is necessary to ensure that these vehicles are safe to operate in traffic. One challenge is to prove that all physically possible variations of situations can be handled safely within the operational design domain of the vehicle. A promising approach to handling the set of possible situations is to identify a manageable number of logical scenarios, which provide an abstraction for object properties and behavior within the situations. These can then be transferred into concrete scenarios defining all parameters necessary to reproduce the situation in different test environments.

Methods: This article proposes a framework for defining safety-relevant scenarios based on the potential collision between the subject vehicle and a challenging object, which forces the subject vehicle to depart from its planned course of action to avoid a collision. This allows defining only safety-relevant scenarios, which can directly be related to accident classification. The first criterion for defining a scenario is the area of the subject vehicle with which the object would collide. As a second criterion, 8 different positions around the subject vehicle are considered. To account for other relevant objects in the scenario, factors that influence the challenge for the subject vehicle can be added to the scenario. These are grouped as action constraints, dynamic occlusions, and causal chains.

Results: By applying the proposed systematics, a catalog of base scenarios for a vehicle traveling on controlled-access highways has been generated, which can directly be linked to parameters in accident classification. The catalog serves as a basis for scenario classification within the PEGASUS project.

Conclusions: Defining a limited number of safety-relevant scenarios helps to realize a systematic safety assurance process for automated vehicles. Scenarios are defined based on the point of the potential collision of a challenging object with the subject vehicle and its initial position. This approach allows defining scenarios for different environments and different driving states of the subject vehicle using the same mechanisms. A next step is the generation of logical scenarios for other driving states of the subject vehicle and for other traffic environments.     

Relationship between frontal car-to-car test result and vehicle crash compatibility evaluation in mobile progressive deformable barrier test

Abstract

Objective: In 2020, the world’s first crash compatibility rating test will be introduced in the European mobile progressive deformable barrier (MPDB) test. In this research, the quantitative change in partner protection performance of large vehicles in car-to-car (C2C) impacts was studied if these large vehicles were designed in future based on MPDB tests addressing crash compatibility ratings.

Methods: Representative vehicles of the European fleet were selected and a Computer Aided Engineering (CAE) parameter study was conducted. In particular, by changing an indicator of structural interaction performance (SD; i.e., the degree of uniformity of barrier deformation)/mass/stiffness of large vehicles systematically in a step-by-step approach, the compatibility evaluation results of large vehicles in MPDB and the occupant injury score of small vehicles in C2C impacts were compared. The CAE result was evaluated compared to that of C2C physical impact tests.

Results: The CAE parameter study showed that in the C2C impact condition, the effects on occupant injury in a small vehicle due to changes in the large vehicle were as follows: (1) SD change: The effect was minor except for small overlap condition. (2) Mass and stiffness change: The effect was relatively major.

On the other hand, compatibility evaluation in the MPDB showed a tendency to overestimate the effect of SD change in comparison with the above-mentioned C2C impact condition.

In addition, physical impact tests showed that, based on SD evaluation, the large vehicle with a relatively inferior compatibility rating compared to those with superior compatibility ratings showed a contradicting trend of better compatibility performance in the C2C test.

Conclusions: The currently proposed compatibility evaluation method of the MPDB test showed some tendency to overestimate the effect of SD change and resulted in quantitatively inconsistent outcomes regarding occupant injury in the partner car in C2C impact conditions.     

CAERvest® – a novel endothermic hypothermic device for core temperature cooling: safety and efficacy testing

Introduction. Cooling of the body is used to treat hyperthermic individuals with heatstroke or to depress core temperature below normal for neuroprotection. A novel, chemically activated, unpowered cooling device, CAERvest®, was investigated for safety and efficacy. Methods. Eight healthy male participants (body mass 79.9?±?1.9?kg and body fat percentage 16.1?±?3.8%) visited the laboratory (20 °C, 40% relative humidity) on four occasions. Following 30-min rest, physiological and perceptual measures were recorded. Participants were then fitted with the CAERvest® proof of concept (PoC) or prototype 1 (P1), 2 (P2) or 3 (P3) for 60 min. Temperature, cardiovascular and perceptual measures were recorded every 5 min. After cooling, the CAERvest® was removed and the torso checked for cold-related injuries. Results. Temperature measures significantly (p?Conclusion. This study demonstrates that the CAERvest® is an effective device for reducing body temperature in healthy normothermic individuals without presence of cold injury. Further research in healthy and clinical populations is warranted.     

A Simulation Study on the Efficacy of Advanced Belt Restraints to Mitigate the Effects of Obesity for Rear-Seat Occupant Protection in Frontal Crashes

Objective: Recent field data analyses have shown that the safety advantages of rear seats relative to the front seats have decreased in newer vehicles. Separately, the risks of certain injuries have been found to be higher for obese occupants. The objective of this study is to investigate the effects of advanced belt features on the protection of rear-seat occupants with a range of body mass index (BMI) in frontal crashes.

Methods: Whole-body finite element human models with 4 BMI levels (25, 30, 35, and 40 kg/m²) developed previously were used in this study. A total of 52 frontal crash simulations were conducted, including 4 simulations with a standard rear-seat, 3-point belt and 48 simulations with advanced belt features. The parameters varied in the simulations included BMI, load limit, anchor pretensioner, and lap belt routing relative to the pelvis. The injury measurements analyzed in this study included head and hip excursions, normalized chest deflection, and torso angle (defined as the angle between the hip–shoulder line and the vertical direction). Analyses of covariance were used to test the significance (P <.05) of the results.

Results: Higher BMI was associated with greater head and hip excursions and larger normalized chest deflection. Higher belt routing increased the hip excursion and torso angle, which indicates a higher submarining risk, whereas the anchor pretensioner reduced hip excursion and torso angle. Lower load limits decreased the normalized chest deflection but increased the head excursion. Normalized chest deflection had a positive correlation with maximum torso angle. Occupants with higher BMI have to use higher load limits to reach head excursions similar to those in lower BMI occupants.

Discussion and Conclusion: The simulation results suggest that optimizing load limiter and adding pretensioner(s) can reduce injury risks associated with obesity, but conflicting effects on head and chest injuries were observed. This study demonstrated the feasibility and importance of using human models to investigate protection for occupants with various BMI levels. A seat belt system capable of adapting to occupant size and body shape will improve protection for obese occupants in rear seats.     

Validity and consistency assessment of accident analysis methods in the petroleum industry

Background. Accident analysis is the main aspect of accident investigation. It includes the method of connecting different causes in a procedural way. Therefore, it is important to use valid and reliable methods for the investigation of different causal factors of accidents, especially the noteworthy ones. Objective. This study aimed to prominently assess the accuracy (sensitivity index [SI]) and consistency of the six most commonly used accident analysis methods in the petroleum industry. Methods. In order to evaluate the methods of accident analysis, two real case studies (process safety and personal accident) from the petroleum industry were analyzed by 10 assessors. The accuracy and consistency of these methods were then evaluated. The assessors were trained in the workshop of accident analysis methods. Results. The systematic cause analysis technique and bowtie methods gained the greatest SI scores for both personal and process safety accidents, respectively. The best average results of the consistency in a single method (based on 10 independent assessors) were in the region of 70%. Conclusion. This study confirmed that the application of methods with pre-defined causes and a logic tree could enhance the sensitivity and consistency of accident analysis.     

Assessment of Bilateral Thoracic Loading on the Near-Side Occupant Due to Occupant-to-Occupant Interaction in Vehicle Crash Tests

Objective: This study aims, by means of the WorldSID 50th percentile male, to evaluate thoracic loading and injury risk to the near-side occupant due to occupant-to-occupant interaction in combination with loading from an intruding structure.

Method: Nine vehicle crash tests were performed with a 50th percentile WorldSID male dummy in the near-side (adjacent to the intruding structure) seat and a THOR or ES2 dummy in the far-side (opposite the intruding structure) seat. The near-side seated WorldSID was equipped with 6 + 6 IR-Traccs (LH and RH) in the thorax/abdomen enabling measurement of bilateral deflection. To differentiate deflection caused by the intrusion, and the deflection caused by the neighboring occupant, time history curves were analyzed. The crash tests were performed with different modern vehicles, equipped with thorax side airbags and inflatable curtains, ranging from a compact car to a large sedan, and in different loading conditions such as car-to-car, barrier, and pole tests. Lateral delta V based on vehicle tunnel acceleration and maximum residual intrusion at occupant position were used as a measurement of crash severity to compare injury measurements.

Result: In the 9 vehicle crash tests, thoracic loading, induced by the intruding structure as well as from the far-side occupant, varied due to the size and structural performance of the car as well as the severity of the crash. Peak deflection on the thoracic outboard side occurred during the first 50 ms of the event. Between 70 to 150 ms loading induced by the neighboring occupant occurred and resulted in an inboard-side peak deflection and viscous criterion. In the tests where the target vehicle lateral delta V was below 30 km/h and intrusion less than 200 mm, deflections were low on both the outboard (20–40 mm) and inboard side (10–15 mm). At higher crash severities, delta V 35 km/h and above as well as intrusions larger than 350 mm, the inboard deflections (caused by interaction to the far-side occupant) were of the same magnitude or even higher (30–70 mm) than the outboard deflections (30–50 mm).

Conclusion: A WorldSID 50th percentile male equipped with bilateral IR-Traccs can detect loading to the thorax from a neighboring occupant making injury risk assessment feasible for this type of loading. At crash severities resulting in a delta V above 35 km/h and intrusions larger than 350 mm, both the inboard deflection and VC resulted in high risks of Abbreviated Injury Scale (AIS) 3+ injury, especially for a senior occupant.     

Polish adaptation of three self-report measures of job stressors: the Interpersonal Conflict at Work Scale,the Quantitative Workload Inventory and the Organizational Constraints Scale

Aim. The objective of the present study was to test the psychometric properties, reliability and validity of three job stressor measures, namely, the Interpersonal Conflict at Work Scale, the Organizational Constraints Scale and the Quantitative Workload Inventory. Method. The study was conducted on two samples (N?=?382 and 3368) representing a wide range of occupations. The estimation of internal consistency with Cronbach's α and the test–retest method as well as both exploratory and confirmatory factor analyses were the main statistical methods. Results. The internal consistency of the scales proved satisfactory, ranging from 0.80 to 0.90 for Cronbach's α test and from 0.72 to 0.86 for the test–retest method. The one-dimensional structure of the three measurements was confirmed. The three scales have acceptable fit to the data. The one-factor structures and other psychometric properties of the Polish version of the scales seem to be similar to those found in the US version of the scales. It was also proved that the three job stressors are positively related to all the job strain measures. Conclusions. The Polish versions of the three analysed scales can be used to measure the job stressors in Polish conditions.     

Efficiency of Filtering Materials Used in Respiratory Protective Devices Against Nanoparticles

The basic aim of this research was to establish the efficiency of filtering materials widely used in respiratory protection devices with particular interest in their porosity, degree of electric and changeable process parameters, such as the flow rate of the test nanoaerosol and the size range of nanoparticles. Tests were carried out with an NaCl solid aerosol of 3.2 × 10⁵ particles/cm³ for the range of particle size of 7–270 nm, at aerosol flow rate of 1800, 2700, 3600, 4500 and 5400 L/h. The tests showed that electrospun nonwovens were the most effective filtering materials for nanoparticles over 20 nm. Melt-blown electret nonwovens with lower porosity than electrospun nonwovens had higher values of penetration of 1%–4%. Those materials provided very efficient protection against nanoparticles of certain sizes only.     

Health impact and noise exposure assessment in the cricket bat industry of Kashmir,India

Aim. The aim of the present study was to identify and evaluate predominant noise sources in the cricket bat industry of Kashmir, India. Methods. Sound levels were measured at operator’s ear level in the working zone of the workers of seven cricket bat factories. The impact assessment was made through personal interviews with each worker separately during their period of rest. Results. On average, 62.5% of the workers reported difficulty in hearing and 24.1% of the workers have become patients for hypertension. Only 58.1% of the workers complained of headache due to high noise level. Conclusions. The workers engaged in the cricket bat industry of Kashmir are exposed to high noise levels. It is suggested that personal protective equipment like ear plugs and ear muffs be used by these workers as a protection against this hazard.