Development of injury criteria for pelvic fracture in frontal crashes

OBJECTIVE: This article assesses the position-dependent injury tolerance of the hip in the frontal direction based on testing of eight postmortem human subjects. METHODS: For each subject, the left and right hemipelvis complex was axially loaded using a previously developed test configuration. Six positions were defined from a seated femur neutral condition, combining flexed, neutral, and extended femur positions with abducted, neutral, and adducted positions. RESULTS: Axial injury tolerances based on peak force were found to be 6,850 +/- 840 N in the extended, neutral position and 4,080 +/- 830 N in the flexed, neutral position. From the flexed neutral orientation, the peak axial force increased 18% for 20 degrees abduction and decreased 6% for 20 degrees adduction. From the extended, neutral orientation, the peak axial force decreased 4% for 20 degrees abduction and decreased 3% for 20 degrees adduction. However, as there is evidence that increases in loading may occur after the initiation of fracture, the magnitude of the peak force is likely related to the extent of injury, not to the initial tolerance. Using the axial femur force at the initiation of fracture (assessed with acoustic crack sensors) as a potentially more relevant indicator of injury may lower the existing injury criteria. This fracture initiation force varied by position from 3,010 +/- 560 N in the flexed, neutral position to 5,470 N in the extended, abducted position. Further, there was a large position-dependent variation in the ratio of fracture initiation force to the peak axial force. The initiation of fracture was 83% of the peak axial force in the extended, abducted position, but the ratio was 34% in the extended, adducted position. CONCLUSIONS: This may have significant implications for the development of pelvic injury criteria by automobile designers attempting to mitigate pelvis injuries.     

The risk of whiplash injury in the rear seat compared to the front seat in rear impacts

One hundred ninety-five rear impacts with both front- and rear-seat occupants in the struck car, where at least one occupant sustained permanent disability, were selected for study. There was a significantly higher disability risk for the female rear-seat occupant compared with the male driver. Furthermore, a higher risk was found for female rear-seat occupants compared with female front-seat passengers. The disability risk for occupants of the driver's seat was three times higher for females than for males, and four times higher for females in the rear seat. In the future, test methods should consider the risk of whiplash injury in both the front and the rear seat.     

Effectiveness of high back belt positioning booster seats in side impacts

OBJECTIVE: The objective of this study is to evaluate the potential of high back booster seats to provide effective protection to children in side impacts. METHOD: This article presents a series of side impact sled tests at a velocity change of 30.5 km/h and a peak deceleration of 15.2 g, using the Hybrid III 6-year-old dummy in two styles of commonly used high-back booster seats: a conventional polystyrene booster seat and a convertible child restraint/booster seat. A series of tests were also performed using alternative anchorage systems in combination with the boosters. Simulated side impact tests were conducted at 90 degrees and 45 degrees. RESULTS: The booster seats tested were found to be too short for the 6-year-old dummy and head contact with the side door occurred in all 90 degree tests, resulting in high HIC values. The greatest potential for achieving effective protection in side impact in this test series was observed when the convertible child restraint/booster was used in combination with a rigid anchorage system. Using this system, the body of the dummy was kept farther away from the door which resulted in a softer head impact with the side door. CONCLUSIONS: Results from this work indicate that current booster seats offer poor torso containment and no head protection for children within the recommended age range. They also showed that the level of protection provided by belt positioning booster seats can be improved through the use of rigid anchorage systems. However, for this potential to be fully realized, belt positioning booster seats must offer better containment of the occupant during the impact.     

A study on chest injury mechanism and the effectiveness of a headform impact test for pedestrian chest protection from vehicle collisions

This study was aimed at investigating the injury mechanism of pedestrian chests in collisions with passenger vehicles of various frontal shapes and examining the influence of the local structural stiffness on the chest injury risk by using the headform impact test at the chest contact area of the vehicle. Three simulations of vehicle to pedestrian collisions were conducted using three validated pedestrian finite element (FE) models of three pedestrian heights of 177 (AM50th), 165 and 150 cm and three FE vehicles models representing a one-box vehicle, a minicar and a medium car. The validity of the vehicle models was evaluated by comparing the headform acceleration against the measured responses from headform impact tests. The chest impact kinematics and the injury mechanisms were analyzed in terms of the distribution of the von Mises stress of the ribcage and in terms of the chest deflections. The chest contact locations on the front panel and the bonnet top were identified in connection to the causation of rib fractures. The risk of rib fractures was predicted by using the von Mises stress distribution. The headform impact tests were carried out at the chest contact area on the front panel and bonnet to examine the safety performance with respect to pedestrian chest protection. In simulations of the one-box vehicle to pedestrian collisions, the chest was struck directly by the frontal structure at a high velocity and deformed substantially, since a shear force was generated by the stiff windshield frame. The acceleration of the headform was related to the rib deflections. The injury threshold of the ribcage deflection (42 mm) corresponded to the headform average acceleration of 68 G. In the minicar collision, the chest was struck with the bonnet top and cowl area at a low velocity, and the deformation was small due to the distributed contact force between the chest and the bonnet top. Besides, the ribcage deformation was too small for bridging a relation between the headform accelerations and rib deflections. In the medium car collision, the deformation mode of the chest was similar to that in the minicar collision. The chest collided with the bonnet top at a low velocity and deformed uniformly. The deflection of the ribs had an observable correlation with the headform accelerations measured in the headform impact tests. The frontal shape of a vehicle has a large influence on a pedestrian’s chest loadings, and the chest deformation depends on the size of the pedestrian and the stiffness of the vehicle. The one-box passenger vehicle causes a high chest injury risk. The headform impactor test can be utilized for the evaluation of the local stiffness of a vehicle’s frontal structure. The reduction of the headform acceleration is an effective measure for pedestrian chest protection for specific shapes of vehicles by efficacy in modifying the local structural stiffness.     

A new laboratory rig for evaluating helmets subject to oblique impacts

Current requirements and regulations governing motorcycle helmets around the world are based on test results of purely radial impacts, which are statistically rare in real accidents. This study presents a new impact rig for subjecting test helmets to oblique impacts, which therefore is able to test impacts of increased statistical relevance to real motorcycle accidents. A number of different head-helmet interfaces have been investigated. A test rig was constructed to produce oblique impacts to helmets simulating those occurring in real motorcycle accidents. A Hybrid III dummy head was fitted with accelerometers to measure the accelerations arising during impact testing. The equipment used for data collection was validated in both translational and rotational acceleration. In order to better resemble the human head, an artificial scalp was fitted to the hybrid dummy. The same test rig was used to investigate the performance of a number of different helmets. Impact velocities ranging from 7.3 to 9.9 m/s were tested using a number of different impact angles and impact areas. This study shows that the new test rig can be used to provide useful data at speeds of up to 50 km/h and with impact angles varying from purely tangential to purely radial. The rotational accelerations observed differ greatly depending on both helmet and scalp designs. For example, a helmet with a sliding outer shell placed on an experimental head fitted with an artificial scalp (made to resemble the human scalp) reduces rotational accelerations of the head by up to 56%, compared with those of an experimental head fitted with a fixed scalp and conventional helmet. The degree of slippage between the skull and the scalp, and between the scalp and the helmet, leads to considerable variation in the results. This innovative test rig appears to provide an accurate method for measuring accelerations in an oblique impact to a helmet. In order to obtain a good level of repeatability in oblique impact testing, it is crucial that the helmet be fixed to the head in the exact same way in each individual test. Both the position and the angle of impact must be reproduced identically in each test. The test rig used here has shown that this type of rig can be used to compare different helmet designs, and it therefore is able to contribute to achieving safer helmets.     

A framework for evaluating OSH program effectiveness using leading and trailing metrics

Introduction

Many employers and regulators today rely primarily on a few past injury/ illness metrics as criteria for rating the effectiveness of occupational safety and health (OSH) programs. Although such trailing data are necessary to assess program success, they may not be sufficient for developing proactive safety, ergonomic, and medical management plans.

Methods

The goals of this pilot study were to create leading metrics (company self-assessment ratings) and trailing metrics (past loss data) that could be used to evaluate the effectiveness of OSH program elements that range from primary to tertiary prevention. The main hypothesis was that the new metrics would be explanatory variables for three standard future workers compensation (WC) outcomes in 2003 (rates of total cases, lost time cases, and costs) and that the framework for evaluating OSH programs could be justifiably expanded. For leading metrics, surveys were developed to allow respondents to assess OSH exposures and program prevention elements (management leadership/ commitment, employee participation, hazard identification, hazard control, medical management, training, and program evaluation). After pre-testing, surveys were sent to companies covered by the same WC insurer in early 2003. A total of 33 completed surveys were used for final analysis. A series of trailing metrics were developed from 1999-2001 WC data for the surveyed companies. Data were analyzed using a method where each main 2003 WC outcome was dichotomized into high and low loss groups based on the median value of the variable. The mean and standard deviations of survey questions and 1999-2001 WC variables were compared between the dichotomized groups. Hypothesis testing was performed using F-test with a significance level 0.10.

Results/Discussion

Companies that exhibited higher musculoskeletal disorder (MSD) WC case rates from 1999-2001 had higher total WC case rates in 2003. Higher levels of several self-reported OSH program elements (tracking progress in controlling workplace safety hazards, identifying ergonomic hazards, using health promotion programs) were associated with lower rates of WC lost time cases in 2003. Higher reported exposures to noise and projectiles were also associated with higher rates of WC cases and costs in 2003.

Impact on Industry

This research adds to a growing body of preliminary evidence that valid leading and trailing metrics can be developed to evaluate OSH effectiveness. Both the rating of OSH efforts and the regular trending of past loss outcomes are likely useful in developing data-driven improvement plans that are reactive to past exposures and proactive in identifying system deficiencies that drive future losses.     

我矿童家院区通风系统的改造与评价

介绍了锡矿山矿务局北矿童家院区北风井通风系统建立的过程,对北风井通风系统投产运行的实际效果进行了评价.     

Factors affecting use and nonuse of child safety car seats in Gorgan,Iran

Objective: Motor vehicle accidents, which are among the main causes of child mortality in Iran and the Middle East, impose staggering costs for the community. Ignoring use of safety devices for children in most motor vehicle crashes will lead to death or serious injury. Because few studies have been performed on effective and predictive factors regarding use of child safety seats, the purpose of this study was to examine the factors affecting the use and nonuse of child safety seats, along with the factors that can facilitate how a child safety seat is used.

Method: This study was conducted in the urban area of Gorgan using a questionnaire. Through random selection, 204 parents with at least one child, aged 8?years or younger, reported their knowledge about the benefits of using a child safety seat.

Results: The results showed that 80% of parents never use a child safety seat, and 13% always use a child safety seat. More than 93% thought that it was necessary to make usage of the child safety seat obligatory. In addition, 80% of parents believed that a child safety seat prevents children from injury in crashes. In addition, 38% of parents were not aware of child safety devices and child safety, less than 20% said that they did not use a child safety seat because their spouse did not support its use, and 28% of them thought that a child safety seat does not affect the safety of the child. In general, 91% of parents reported that if child safety seat use were mandated, the frequency of use would increase. A law on the use of child safety seats is a very important variable in their use, which can enhance the chance of using a child safety seat by 6.5 times.

Conclusion: Special instructions should be developed to create incentive strategies for using a child safety seat. Mandating the use of a child safety seat, equipping cars with a child safety seat, encouraging children to use it, and providing continuous education and training are important factors for increasing the use of child safety seats.     

A methodology for assessing blast protection in explosive ordnance disposal bomb suits.

To reduce human casualties associated with explosive ordnance disposal, a wide range of protective wear has been designed to shield against the blast effects of improvised explosive devices and munitions. In this study, 4 commercially available bomb suits, representing a range of materials and armor masses, were evaluated against 0.227 and 0.567 kg of spherical C-4 explosives to determine the level of protection offered to the head, neck, and thorax. A Hybrid III dummy, an instrumented human surrogate [1], was tested with and without protection from the 4 commercially available bomb suits. 20 tests with the dummy torso mounted to simulate a kneeling position were performed to confirm repeatability and robustness of the dummies, as well as to evaluate the 4 suits. Correlations between injury risk assessments based on past human or animal injury model data and various parameters such as bomb suit mass, projected area, and dummy coverage area were drawn.     

论劳动保护监察的基本程序

简述了劳动保护及其监察过程 ,系统地分析了各类劳动保护监察过程的具体步骤 ,也就是监察准备、监督检查、监察处理、行政制裁和申请司法干预五个阶段     

A comparison of required coefficient of friction for both feet in level walking

The required coefficient of friction (RCOF) is one of the critical elements in determining whether a slip incident might occur. Most researchers, when measuring RCOF, do not differentiate between the two feet of the same participant under the same walking condition. Results from a recent study (Chang et al., 2010) indicated that the stochastic distributions of the RCOF of both feet were different in 76% of the cases. Using the previous data (Chang et al., 2010), this paper presents a comparison of the RCOF for both feet of 50 participants under four level walking conditions resulting from two footwear types and two walking speeds using a t-test, commonly used by safety professionals to compare two pools of data. The current results indicated that 78% of the RCOF data showed a statistically significant difference between the RCOF from two feet for the same participant under each walking condition. The results of the logistic regression analysis used to identify factors that contributed to the outcome of the t-test indicated that the walking speed was the only factor with a statistical significance (p = 0.044).     

The NIOSH program for evaluating biomechanical hazards in the workplace

Twenty evaluations of reported biomechanical hazards were performed by the National Institue for Occupational Safety and Health (NIOSH) at the request of industrial workers or management over an 8-year period. The evaluations were part of the Hazard Evaluation and Technical Assistance (HETA) program authorized under the Occupational Safety and Health Act of 1970. A number of these evaluations are described here. Principles drawn from the field of ergonomics were used to evaluate whether a certain work activity has caused an observed incidence of cumulative trauma to the neuro-musculo-skeletal system. Procedures for conducting these ergonomic evaluations are reviewed, and the results are summarized. Recommendations are made for implementing control procedures, and the problem of obtaining reliable follow-up information is discussed. Project results suggest an encouraging degree of success in accomplishing prevention and control of biochemical hazards in the workplaces studied.     

A comparison of three observational techniques for assessing postural loads in industry.

This study aims to compare 3 observational techniques for assessing postural load, namely, OWAS, RULA, and REBA. The comparison was based on the evaluation results generated by the classification techniques using 301 working postures. All postures were sampled from the iron and steel, electronics, automotive, and chemical industries, and a general hospital. While only about 21% of the 301 postures were classified at the action category/level 3 or 4 by both OWAS and REBA, about 56% of the postures were classified into action level 3 or 4 by RULA. The inter-method reliability for postural load category between OWAS and RULA was just 29.2%, and the reliability between RULA and REBA was 48.2%. These results showed that compared to RULA, OWAS, and REBA generally underestimated postural loads for the analyzed postures, irrespective of industry, work type, and whether or not the body postures were in a balanced state.     

A fairer examination of rating scales when used for performance appraisal in a real organizational setting

Fifty-seven managers in an aircraft plant who had received rater training, appraised their subordinates (n = 376) using both a BARS format and a graphic scale. Less leniency and halo effect occurred with the BARS format. In addition, the use of BARS resulted in higher interrater reliability than ratings obtained with the graphic scale. Finally, the overall (global) evaluation derived with the BARS form was significantly less susceptible to leniency effect. A tentative conceptual framework to explain this finding was suggested.     

A novel methodology for evaluating the change of existing operational staffing levels (MCSL) in the chemical industry

Operational manning levels in the chemical industry not reflecting real circumstances and/or not taking into account various possible accident scenarios can be financially adversarial and can even lead to (minor and major) accidents. This paper provides a methodology to assist chemical companies in analyzing changes of their existing operational staffing levels. The method can be implemented within the entire organization or within a part thereof (i.e., a business unit or an installation). The method has been applied in a major chemical company in Belgium. The Belgian case illustrates the user-friendliness of the suggested manning level risk analysis method.     

A comparison of pretreatment methods for bioethanol production from lignocellulosic materials

Lignocellulosic materials, which consist mainly of cellulose, hemicellulose and lignin, are among the most promising renewable feedstocks for the production of energy and chemicals. Bioethanol is a major biofuel that can be produced from lignocellulosic materials. Its production typically involves a hydrolysis-fermentation route, which has three main steps: pretreatment to get fermentable sugars, fermentation to produce bioethanol, and a separation process to obtain highly concentrated bioethanol. The pretreatment step has been recognized as a technological bottleneck for the cost-effective development of bioprocesses from lignocellulosic materials. In this work we analyze the potential of several pretreatment methods for bioethanol production from lignocellulosic materials. Simulations based on stoichiometric relations and yield data were conducted to evaluate the energy requirements of each pretreatment method. Other parameters were also considered such as the cost of chemicals, consumption of water, and constraints on the composition of inhibitors. Performance benchmarks were identifies using targeting techniques and these benchmarks were used to assess the actual performance of the alternatives. The combination of the evaluated parameters with target production values obtained from reported yields served as the basis for identifying the most promising pretreatment options and for defining areas of opportunities. This approach uses limited information, but it provides reliable results in order to reduce the number of pretreatment alternatives. The target production usage gives an estimation of the global process efficiency without the completed flowsheet defined.     

冶金企业环保设施管理

论述冶金企业搞好环保设施管理的意义,提出了一些管理的办法。