Potential use for plastics in automobiles

Before looking into the future to determine the potential for polymeric materials within the vehicle of tomorrow, an evaluation of the factors behind the use of plastic components in today's car is required. Once identified an examination of their importance on tomorrow's vehicle together with key new issues, which are likely to play a decisive role in vehicle design can be made. A study of the developements within the plastic material and process environments to overcome current limitations can then lead to an idea of the future potential of polymers within the vehicle.     

Plane-disturbance propagation in elastic nonhomogeneous media. General solution

This paper deals with the problem of uniaxial propagation of disturbances in continuous axiallynonhomogeneous media. The general mathematical solution obtained is applicable to physical problems dealing with media with longitudinally-variable parameters.Solution of the resulting differential equations is based on symmetry of their space and time variables. This symmetry leads to transformation of boundary problems into their initial and terminal counterparts. By working out a special version of Fourier's transform, a law for uniaxial propagation in nonhomogeneous media is derived. It is shown that D'Alembert's well-known solution for propagation in a homogeneous thin bar or string is a particular case of this law.The significance of such a general theory lies in the fact that most dynamic phenomena in nature occur in nonhomogeneous media, and the solution presented here may contribute to their physical evaluation. As an example, we solve the propagation of a pulse in a heated thin bar.     

The effects of driving experience on responses to a static hazard perception test

Novice drivers exhibit deficits in hazard perception that are likely to increase their risk of collisions. We developed a static hazard perception test that presents still images to observers and requires them to indicate the presence of a traffic conflict that would lead to a collision. Responses to these scenes were obtained for young adult novice (N = 29) and experienced drivers (N = 27). Additionally, participants rated the hazard risk and clutter of each scene. Novice drivers rated traffic conflicts as less hazardous and responded more slowly to them. Using a subset of 21 scenes, we were able to discriminate novice and experienced young adult drivers with a classification accuracy of 78% and a scale reliability (Cronbach's alpha) of .91. The potential applications of this research include the development of standardized hazard perception tests that can be used for driver evaluation, training and licensure.     

Meaning and contextualisation in risk assessment

This paper presents an analysis of the construction of risk as a social process. It provides a critique of Jasanoff's ‘two cultures’ model of the risk assessment community, arguing that corresponding rhetorics serve to obscure the hybrid nature of risk. It is argued that a new perspective, based on the contextualisation of expert scientific knowledge is needed, which transcends reductionist tendencies that view risk assessment as simply about either material artefacts or social constructions. Such approaches have the potential, it is suggested, to address not only the complexity but also the moral and political dilemmas associated with a wide range of risk management problems.     

New vistas for technology and risk assessment? The OECD Programme on Emerging Systemic Risks and beyond

This paper presents a framework for understanding risk from the perspective of technological innovation and change. Special focus is put on systemic technological change, which tends to affect several dimensions of society at the same time. By drawing on innovation theory, and exemplifying by reference to the OECD futures project on Emerging Systemic Risk, the article elaborates a framework for technology assessment where the central elements are ubiquitous technological change and risk. Several key dimensions for technology assessment of this kind are identified, including increased mobility of people and goods, magnitude and concentration of humans, the speed and depth of change in the risk landscape, public to private shifts in the ‘ownership’ of risk, and the role played by expectations and perception to risk. The article ends with suggesting a number of new norms for risk and technology assessment coupled with new risk methodologies for further investigation.     

Development co-operation training seminar at The Hague—‘Technical information as an aid to industrial development’

The main objective of the seminar for developing country nationals, the third of which took place at The Hague in September 1981, is to provide an introduction to the use of patent documents and patent office documentation centres as sources of technical information, thus promoting awareness of their potential value to users, which is all too often not appreciated.This article describes the programme for the seminar and presents the participants' assessment of the extent of its success.     

Models of mechanisms for the vapor phase emission of hazardous chemicals from landfills

Quantities of hazardous chemicals have been placed in sanitary landfills in conjunction with solid waste. This paper presents three vapor phase transport mechanisms: molecular diffusion, bio-gas convection, and barometric pressure pumping. These mechanisms are incorporated into a dynamic model that simulates the emission flux rate of chemicals, as a function of landfill and environmental variables. The simulation model is driven by time-varying atmospheric pressure fluctuations. Darcy's law is used to simulate gas movement through the landfill cap material to and from the landfill cells. With all mechanisms operative, a rate of 290 g benzene/m² d was obtained from the model using benzene as a test chemical. Atmospheric pressure fluctuations pump toxic vapors and gases from the storage cells of hazardous waste landfills to the air above. This pumping enhances the vapor phase molecular diffusion process. The calculated benzene flux rate with diffusion and atmosphere pumping was 13 g/m² d. Uncertainties and limitations of the model are considered which include: vapor and gas circulation in and between cells, adsorption onto solids and multi-cell landfills. The model presented is a practical tool for initial evaluation studies of volatile chemical emissions from landfills and provides a basis upon which to construct more realistic simulation models.     

Generalized railway tank car safety design optimization for hazardous materials transport: addressing the trade-off between transportation efficiency and safety

North America railways offer safe and generally the most economical means of long distance transport of hazardous materials. Nevertheless, in the event of a train accident releases of these materials can pose substantial risk to human health, property or the environment. The majority of railway shipments of hazardous materials are in tank cars. Improving the safety design of these cars to make them more robust in accidents generally increases their weight thereby reducing their capacity and consequent transportation efficiency. This paper presents a generalized tank car safety design optimization model that addresses this tradeoff. The optimization model enables evaluation of each element of tank car safety design, independently and in combination with one another. We present the optimization model by identifying a set of Pareto-optimal solutions for a baseline tank car design in a bicriteria decision problem. This model provides a quantitative framework for a rational decision-making process involving tank car safety design enhancements to reduce the risk of transporting hazardous materials.     

Sustainable and safe design of footwear integrating ecological footprint and risk criteria

The ecodesign of a product implies that different potential environmental impacts of diverse nature must be taken into account considering its whole life cycle, apart from the general design criteria (i.e. technical, functional, ergonomic, aesthetic or economic). In this sense, a sustainability assessment methodology, ecological footprint (EF), and environmental risk assessment (ERA), were combined for the first time to derive complementary criteria for the ecodesign of footwear. Four models of children's shoes were analyzed and compared. The synthetic shoes obtained a smaller EF (6.5 gm(2)) when compared to the leather shoes (11.1 gm(2)). However, high concentrations of hazardous substances were detected in the former, even making the Hazard Quotient (HQ) and the Cancer Risk (CR) exceed the recommended safety limits for one of the synthetic models analyzed. Risk criteria were prioritized in this case and, consequently, the design proposal was discarded. For the other cases, the perspective provided by the indicators of different nature was balanced to accomplish a fairest evaluation. The selection of fibers produced under sustainable criteria and the reduction of the materials consumption was recommended, since the area requirements would be minimized and the absence of hazardous compounds would ensure safety conditions during the use stage.     

Organizational processes and nuclear power plant safety

This paper describes an integrated effort to define and measure organizational factors related to nuclear power plant safety. The research began by reviewing previously conducted studies looking at nuclear power operations and operations in other high reliability industries for indications of common safety-related, performance dimensions. Having established a list of 20 common dimensions, the project went on to fully define these dimensions and develop methods for their assessment. The methods of assessment developed for this application were employee survey—a series of self report questions answered by employees, behavioral checklist—sets of statements about the plant and its operations that observers respond to by answering yes or no, structured interview—a set of questions and interviewer asks of an employee and built around the 20 dimensions identified, and behaviorally anchored rating scales—an extension of the methodology used for assessing the performance of individuals to the process of assessing a nuclear power plant. Each of the methodologies is described as it applies to the assessment within the nuclear power environment and examples of each method are presented. Pilot tests of the feasibility of using these assessment methods were conducted in two nuclear power plants and the results are encouraging both in terms of the immediate identification of potential safety issues and as valuable additions to probabilistic risk assessment. Implications of this work for the future assessment of organizational factors related to nuclear power safety are discussed.     

SCAP: a new methodology for safety management based on feedback from credible accident-probabilistic fault tree analysis system

As it is conventionally done, strategies for incorporating accident--prevention measures in any hazardous chemical process industry are developed on the basis of input from risk assessment. However, the two steps-- risk assessment and hazard reduction (or safety) measures--are not linked interactively in the existing methodologies. This prevents a quantitative assessment of the impacts of safety measures on risk control.We have made an attempt to develop a methodology in which risk assessment steps are interactively linked with implementation of safety measures. The resultant system tells us the extent of reduction of risk by each successive safety measure. It also tells based on sophisticated maximum credible accident analysis (MCAA) and probabilistic fault tree analysis (PFTA) whether a given unit can ever be made 'safe'. The application of the methodology has been illustrated with a case study.     

Technical diagnostics in accident risk assessment

For a comprehensive assessment of safety of hazardous facilities, an accident risk ratio is used. Existing methodologies of risk assessment do not account for technical conditions of the facility and the degree of its defectiveness. This work demonstrates the possibility and necessity of a broader use of nondestructive testing (NDT) and technical diagnostics (TD) to estimate the probability of an accident, formulates the requirements for analyzing the risk, and establishes the line of development for these approaches. We consider the issues related to introducing new requirements for NDT and TD, which deal with representing the quantitative values of NDT, i.e., reliable data on the size of defects and measurement errors. We prove the necessity of using the methods of probabilistic fracture mechanics for assessing the real values of accident probability.     

A systematic approach to the search for variational principles for plane steady flows

Using Vainberg's theorem of nonlinear potential operators, alternate potential principles associated with the differential equations governing the gasdynamics of plane steady irrotational diabatic flow and isoenergetic rotational adiabatic flow are formulated and their equivalence with Bateman's principle is established. Further, the advantage usefulness of treating a single nonlinear equation for the existence and hence formulation of a functional over the equivalent system for the same problem is brought into sharper focus.     

Safety risk assessment and management—the ESA approach

The European Space Agency ESA aims at minimizing the safety risks of their space flight projects. Hazard and risk reduction is supported by hazard analysis and probabilistic risk assessment. In hazard analysis hazardous conditions and accident scenarios are identified. Risk assessment is the probabilistic evaluation of accident scenarios and is the basis for risk management. The risk assessment method involves the determination and propagation of event probability. Expert judgement is used in a structured way. In risk management the risk assessment results are used to prioritize and optimize risk reduction efforts and to support risk acceptance evaluations.     

Overall strategy for risk evaluation and priority setting of risk regulations

This paper presents the framework of an approach to support planning and priority setting for risk control. Such an approach could assist government/regulatory authorities in their allocation of resources among different sectors. The term risk will here be used in a very wide sense, and it will include, but not restrict to, the traditional HES (Health, Environment and Safety) concept. An overall classification of risk (‘loss categories’), to be used across sectors and directorates is suggested. The risk evaluation includes a number of factors not accounted for in a standard risk assessment, but should be taken into account when authorities set priorities regarding risk control. Sociological, psychological and ethical perspectives are included, and the need for a discourse during the decision process is pinpointed. The paper also discusses the potential inclusion of cost benefit analyses in such an approach. The indicated approach is denoted Risk Across Sectors (RAS), and suggestions regarding the process to implement it are given. Such an implementation process will by itself increase the knowledge and competence of the involved parties.     

Methodological framework for developing decision support systems (DSS) for hazardous materials emergency response operations

The production, storage, and transportation of hazardous materials are processes of vital economic importance for any advanced and technologically complex society. Although the production and distribution of hazardous materials is associated with economic development, there is a significant potential danger to the natural and social environment in the event of their accidental release, a fact that prompts for the development and implementation of methods and techniques that aim to improve hazardous materials risk management decisions. The objective of this paper is to present a unified framework for developing a Decision Support System (DSS) for supporting a vital function of risk management, namely the management of emergency response operations. The proposed framework recognizes the peculiarities of the hazardous materials decision-making environment which is characterized by: (i) multiple stakeholders, i.e., persons and organizations involved in and affected by hazardous materials risk management decisions; (ii) lack of a formal management structure for monitoring and controlling in a unified manner all Emergency Response Resources; (iii) lack of clear distinction and fragmentation of responsibilities of the actors involved in risk management operations; and (iv) dynamic/real-time decisions, i.e., risk determinants change over time. The proposed framework was used in order to develop a DSS for managing emergency response operations for large scale industrial accidents in Western Attica, Greece.     

Using transportation accident databases to investigate ignition and explosion probabilities of flammable spills

Risk assessment of hazardous material spill scenarios, and quantitative risk assessment in particular, make use of event trees to account for the possible outcomes of hazardous releases. Using event trees entails the definition of probabilities of occurrence for events such as spill ignition and blast formation. This study comprises an extensive analysis of ignition and explosion probability data proposed in previous work. Subsequently, the results of the survey of two vast US federal spill databases (HMIRS, by the Department of Transportation, and MINMOD, by the US Coast Guard) are reported and commented on. Some tens of thousands of records of hydrocarbon spills were analysed. The general pattern of statistical ignition and explosion probabilities as a function of the amount and the substance spilled is discussed. Equations are proposed based on statistical data that predict the ignition probability of hydrocarbon spills as a function of the amount and the substance spilled. Explosion probabilities are put forth as well. Two sets of probability data are proposed: it is suggested that figures deduced from HMIRS be used in land transportation risk assessment, and MINMOD results with maritime scenarios assessment. Results are discussed and compared with previous technical literature.     

Integrated risk analysis for acute and chronic exposure to toxic chemicals

The traditional practice to assess and evaluate different types of risk in isolation to each other are liable to give erroneous results. Integrated risk assessment is an answer to overcome this problem. This paper presents the cumulative or integrated assessment of acute risk posed by accidental release of hazardous chemical (e.g. chlorine) and chronic risk induced by toxic chemicals (e.g. cadmium, chromium and nickel) present in the ambient environment. The present study has been carried out in a most simplified way to demonstrate and appreciate the broader context of integrated risk analysis (IRA). It has been observed that the inclusion of background risk factors (BRF) in individual risk factors (IRF) related to an industry may significantly alter the siting and planning strategies of that industry.     

Anisotropic constitutive equations and schur's lemma

The symmetry properties of a material impose restrictions on the form of the constitutive expressions employed to describe the response of the material. We employ the methods of group representation theory and Schur's lemma to obtain the general form of the constitutive expression which is consistent with the restrictions imposed by material symmetry.