Joel P. Clark

Life‐Cycle Assessment and Temporal Distributions of Emissions: Developing a Fleet‐Based Analysis

Although the product‐centered focus of life‐cycle assessment has been one of its strengths, this analytical perspective embeds assumptions that may conflict with the realities of environmental problems. This article demonstrates, through a series of mathematical derivations, that all the products in use, rather than a single product, frequently should be the appropriate unit of analysis. Such a “fleet‐centered” approach supplies a richer perspective on the comparative emissions burdens generated by alternative products, and it eliminates certain simplifying assumptions imposed upon the analysis by a product‐centered approach. A sample numerical case, examining the comparative emissions of steel‐intensive and aluminum‐intensive automobiles, is presented to contrast the results of the two approaches. The fleet‐centered analysis shows that the “crossover time” (i.e., the time required before the fuel economy benefits of the lighter aluminum vehicle offset the energy intensity of the processes used to manufacture the aluminum in the first place) can be dramatically longer than that predicted by a product‐centered life‐cycle assessment. The fleet‐centered perspective explicitly introduces the notion of time as a critical element of comparative life‐cycle assessments and raises important questions about the role of the analyst in selecting the appropriate time horizon for analysis. Moreover, with the introduction of time as an appropriate dimension to life‐cycle assessment, the influences of effects distributed over time can be more naturally and consistently treated.

Materials selection and multi-attribute utility analysis

SummaryMulti-attribute utility analysis (MAUA) has emerged as a powerful tool for materials selection and evaluation. An operations research technique, MAUA has been used in a wide range of engineering areas, of which materials science and engineering is one of the more recent. Utility analysis affords a rational method of materials selection which avoids many of the fundamental logical difficulties of many widely used alternative approaches. However, MAUA has traditionally been used in materials selection problems only, in which there is certainty regarding the attribute levels of the alternatives. For many new technologies this is not the case. Another operations research technique, subjective probability assessment (SPA), can be used to address this issue. SPA makes it possible to measure a probabilistic distribution describing the confidence of the decision maker in the levels of attributes for which there is a high degree of uncertainty. These probability distributions can be used in conjunction with MAUA to provide a consistent framework for making materials selection decisions. Furthermore, the use of these techniques extends beyond the problem of materials selection into the more speculative areas of materials competitiveness and market demand in cases involving new, unproven technologies.

Market model simulation: The impact of increased automotive interest in magnesium

Due to increasing energy and environmental concerns automakers have recently become more interested in lightweight alternatives to traditional component designs. Magnesium, the lightest standard engineering metal, has often been cited as showing potential in the automotive world, but has been resisted by automakers due to high prices and limited availability. Small production resources of magnesium limit the potential of magnesium in the automotive arena if growth in interest leads to material shortages and price volatility. To investigate the dynamics of the magnesium market, a system dynamics simulation model of the market was created. The model, which simulates supply, demand, and price interactions, was used to investigate market stability strategies that will benefit all market players

Life-cycle analysis of automobiles: A critical review of methodologies

Life-cycle analysis (LCA) has been described by its proponents as an environmental panacea, capable of providing engineers, designers, and managers with everything that they need to make environmentally correct decisions. Unfortunately, the goals of the technique and the reality of its application are very different. Like any analytical technique, its application requires the imposition of assumptions to accommodate limitations in budgets, resources, and know-how. Furthermore, the evaluation of the analytical results introduces questions of strategy and priority that are currently unresolved. Thus, while the concepts underlying LCA are readily understandable, the practical application of the method has substantial problems.

Defining markets for new materials: Developing a utility methodology with case application

Abstract A utility methodology to identify profitable market segments for the use of new materials is presented and illustrated by application to the automobile industry. The method has three parts: empirical, statistical and analytical. The first measures company preferences for the important attributes of a use of a material, applying single-attribute utility functions. The second identifies market segments, by determining significant differences between measured preferences with t -tests. The third estimates the premium these market segments would pay for a product made of a new material, using multiattributable utilities, and thus determines profitable market segments. The case study of valve trains containing ceramic components defined two market segments: companies with either a broad world market or a narrow speciality. The immediate buyers of these valve trains are likely to be producers of high-value, six-cylinder automobiles, who seem prepared to pay a significant premium for this product.

The potential for advanced ceramics in automotive engine applications

Although the progress in industrial application of structural ceramics was over-forecast in the last decade, the materials appear to be on the cusp of application in certain automotive components. This article reports on a study of the economics of replacing certain metallic automobile valve-train components with ceramic components. Because of the costs of the materials and the associated processes, ceramic parts are most competitive in new designs and when used as valve-train systems.

Automobile recycling: Environmental policymaking in a constrained marketplace

Rising interest in legislated recycling initiatives has brought increased attention to the recyclability of the automobile. Recycling itself is one of a series of environmental initiatives that have gained momentum in recent years. However, recycling is also an industrial process, and as such is subject to technological realities and market pressures. In that light, this article presents an economic picture of the materials cycle in automobile recycling.

Mining manganese nodules : Potential economic and environmental effects ag]

Abstract This article examines the economic implications of mining or of not mining manganese nodules and summarizes potential ecological consequences. Apart from possible net economic benefits to certain countries, mining the nodules is not regarded as an economic or strategic necessity. It is concluded that expansion of basic research on oceanfloor ecosystems must be granted high priority. It is in the best interest of developed countries to become signatories of the LOS Convention in order to participate in the development of the regulatory framework and to avoid the antagonism of the international community.

US copper supply : An economic/engineering analysis of cost—supply relationships

Abstract The authors present short- and long-term supply schedules for the primary US copper industry. These schedules are based on the economic theory of supply, and are derived from site- and input-specific cost data. Cost figures are arrived at by a combination of engineering process analysis and statistical cost estimation. The supply functions can be used to evaluate the effects of changes in market, policy, or other variables on US copper supply.

Markets for advanced structural ceramics

Abstract The potential market for advanced structural ceramics is large but also uncertain. In this paper a quantitative framework is used to investigate the production economics and potential markets for ceramic materials in four representative applications, ie cutting tool inserts, turbocharger rotors, automotive valve guides and mechanical seals. The economic and technical conditions necessary for growth to be demonstrated in these ceramic markets are identified and estimates are made of feasible market size values, both in dollars and pounds of powder consumed.