Margin of safety for the human back: a probable consensus based on published studies

Despite numerous efforts to control occurrences of work-related low back pain, it continues to be a significant problem. Since the causation of low back pain is under multifactorial control, it is suggested that the factor most vulnerable at any given time will determine the safety. Epidemiological, biomechanical, physiological, and psychophysical information presented in published literature has been analysed. The data available are related to injuries and the projected margin of safety. This paper therefore, is an integrative, inferential synthesis of the published work to discern the margin of safety. An attempt has been made to conclude, on the basis of objective evidence, an all encompassing criterion to ensure the safety of the back. The psychophysical approach appears to integrate biomechanical and physiological variables on a short term basis in the studies surveyed. However, it remains to be proven that the sensory conditioning due to prolonged and repetitive occupational tasks will remain responsive to cumulative load and fatigue failures.     

Aggregate nonparametric safety analysis of traffic zones

Exploring the significant variables related to specific types of crashes is vitally important in the planning stage of a transportation network. This paper aims to identify and examine important variables associated with total crashes and severe crashes per traffic analysis zone (TAZ) in four counties of the state of Florida by applying nonparametric statistical techniques such as data mining and random forest. The intention of investigating these factors in such aggregate level analysis is to incorporate proactive safety measures in transportation planning. Total and severe crashes per TAZ were modeled to provide predictive decision trees. The variables which carried higher weight of importance for total crashes per TAZ were – total number of intersections per TAZ, airport trip productions, light truck productions, and total roadway segment length with 35 mph posted speed limit. The other significant variables identified for total crashes were total roadway length with 15 mph posted speed limit, total roadway length with 65 mph posted speed limit, and non-home based work productions. For severe crashes, total number of intersections per TAZ, light truck productions, total roadway length with 35 mph posted speed limit, and total roadway length with 65 mph posted speed limit were among the significant variables. These variables were further verified and supported by the random forest results.     

GB5226.1-2008新版国家强制性标准综述

针对新版GB5226.1-2008国家强制性标准,本文介绍了该标准的基本情况、制修订背景、主要差异等方面内容,并讨论了标准的关键问题和使用指南等。     

阀瓣类型对安全阀动作性能影响的试验研究

以升力传感器作为统一的衡量标准,对其进行静态标定,建立升力传感器输出信号与安全阀整定压力的关系;然后分析了安全阀全启排放现场实验的大量实测数据,通过对比传统刚性阀瓣与各种柔性阀瓣动作性能的差异,讨论了不同类型阀瓣对开启时间、回座时间、开启压力、排放压力、回座压力和排放稳定性等主要动作性能的影响,为合理地设计阀瓣提供了一些准则和依据。     

Speed choice by drivers: The issue of driving too slowly

Quite correctly, the majority of road safety speeding initiatives focus on drivers travelling at excessive speeds. This study, however, focused on the potential problem of driving too slowly. Six thousand, four hundred and eighty vehicles from around the Perth metropolitan area in Western Australia had their speeds recorded; observations were also made of these vehicles to identify characteristics of the driver and vehicle. In addition, a community survey with 240 members of the public was conducted to examine their attitudes towards slow drivers. As expected, results showed that older drivers drove more slowly than the other age brackets, women drove more slowly than men, and that heavily laden vehicles drove more slowly than other types of vehicles. Additionally, the slowest days were weekdays and the quickest were Saturdays. Community attitudes, generally mirrored the observational findings, and indicated that the public believed that slow driving was sometimes a safety problem causing some accidents. These data are discussed, and some possible countermeasures are briefly introduced to address the problem.     

Critical Time Intervals for Taking in Flight Information in a Ball-Catching Task

A ball-catching task in which the ball was caused to enter on a parabolic flight path by means of a mechanical apparatus was administered to 36 male students between the ages of 18 and 40 years. An electronic device enabled the ball to be illuminated for predetermined temporal intervals during its flight. Results indicated that in this relatively unpredictable task opportunity to watch the ball for longer periods of time resulted in increased catching success. Results are discussed in relation to previous experimental work in which the ball was on a more predictable trajectory (since output information was available) and are related to the perceptual moment hypothesis.     

The development of railway safety in Finland

This study reviews the development of railway safety in Finland from 1959 to 2008. The results show that the level of safety has greatly improved over the past five decades. The total number of railway fatalities did not show any obvious decreasing or increasing trend during the first decade, but since the early 1970s the annual number of fatalities has decreased from about 100 to 20. The estimated overall annual reduction per year from 1970 to 2008 was 5.4% (with a 95% confidence interval from −8.2% to −2.6%). The reduction in subcategories per million train-kilometres from 1959 to 2008 was 4.4% per year for passengers, 8.3% for employees, 5.0% for road users at level crossings and 3.6% for others (mainly trespassers). The safety improvement for passengers and staff was probably influenced by the introduction of central locking of doors in passenger cars and improved procedures to protect railway employees working on the tracks. The number of road users killed at level crossings has fallen due to the installation of barriers and the construction of overpasses and underpasses at crossings with dense traffic, removal of level crossings, and an improvement of conditions such as visibility at crossings. The number of trespasser fatalities has seen the least decline. Key plans for the future include further reduction of the number of level crossings on the state railway network from the current roughly 3500–2200 by 2025, and involving communities in safety work related to railway trespassers.     

Developing historical technical basis for material and package classification and package test requirements of international transport safety regulations

Abstract

In a companion PATRAM 2013 paper, C. Bajwa et al. provide an overview of international level efforts that began in 2010 to develop a comprehensive and detailed Technical Basis Document (TecBasDoc) to support the current International Atomic Energy Agency (IAEA) Transport Regulations (SSR-6, 2012) and future revisions thereto. The draft TecBasDoc that has so far resulted from efforts by a large number of IAEA staff and international experts exceeds 300 pages in length using, to the greatest extent possible, historical documents dating as far back as the 1950s as reference material. The intent is to capture, for those Member States new to transport and for future generations, the scientific and technical heritage of the several decades of development that has occurred in transport safety, preserving this knowledge for future reference. The latest effort, in December 2012, involved consultants to the IAEA adapting the draft to reflect guidance from the IAEA’s Transport Safety Standards Committee and delving into the IAEA’s archives searching out many long sought, older supporting documents. This paper elaborates on Chaps. 8–10 of the TecBasDoc, dealing with respectively Classification of Materials, Classification of Packages and Package Design and Testing. Chapter 8 elaborates on the many decisions resulting in an initial nine material classifications, which focused more on the physical and not the radioactive characteristics of the materials, to the current, significantly different classifications that focus more on the material’s radioactive properties. Chapters 9 and 10 combine to provide extensive, detailed elaboration on why decisions were made concerning the various package classifications and the associated design, testing and acceptance requirements associated with each package type. Chapter 10 cites two extensive supporting appendices. These three chapters and two appendices currently cite and elaborate on >200 historical documents. Efforts are underway to make this extensive document base more complete and to make as many documents as possible available electronically. In this paper, each of these three drafted chapters and the two supportive appendices are overviewed, providing insight into key and typical findings that have been uncovered and incorporated into the draft document. The many experts who have contributed to the current draft are appropriately acknowledged.     

Out-of-plane constraint effect on local fracture resistance of a dissimilar metal welded joint

An experimental investigation on effect and mechanism of out-of-plane constraint induced by specimen thickness on local fracture resistance of two cracks (A508 heat-affected-zone (HAZ) crack and A508/Alloy52Mb interface crack) located at the weakest region in an Alloy52M dissimilar metal welded joint (DMWJ) between A508 ferritic steel and 316L stainless steel in nuclear power plants has been carried out. The results show with increasing out-of-plane constraint (specimen thickness), the fracture mechanism of the two cracks changes from ductile fracture through mixed ductile and brittle fracture to brittle fracture, and the corresponding crack growth resistance decreases. The crack growth path in the specimens with different out-of-plane constraints deviates to low-strength material side, and is mainly controlled by local strength mismatch. For accurate and reliable safety design and failure assessment of the DMWJ structures, it needs to consider the constraint effect on local fracture resistance. The new safety design and failure assessment methods incorporating both in-plane and out-of-plane constraint effects need to be developed for the DMWJ structures.     

Regulations and research on RC&S for hydrogen storage relevant to transport and vehicle issues with special focus on composite containments

Developers interested in high pressure storage of hydrogen for mobile use increasingly rely on composite cylinders for onboard storage or transport of dangerous goods. Thus, composite materials and systems deserve special consideration. History gives interesting background information important to the understanding of the current situation as to regulations, codes and standards.