Cynthia F. Murphy

Energy-water nexus for mass cultivation of algae.

Microalgae are currently considered a potential feedstock for the production of biofuels. This work addresses the energy needed to manage the water used in the mass cultivation of saline, eukaryotic algae grown in open pond systems. Estimates of both direct and upstream energy requirements for obtaining, containing, and circulating water within algae cultivation systems are developed. Potential productivities are calculated for each of the 48 states within the continental U.S. based on theoretical photosynthetic efficiencies, growing season, and total available land area. Energy output in the form of algal biodiesel and the total energy content of algal biomass are compared to energy inputs required for water management. The analysis indicates that, for current technologies, energy required for water management alone is approximately seven times greater than energy output in the form of biodiesel and more than double that contained within the entire algal biomass. While this analysis addresses only currently identified species grown in an open-pond system, the water management requirements of any algae system will be substantial; therefore, it is critical that an energy assessment of water management requirements be performed for any cultivation technology and algal type in order to fully understand the energy balance of algae-derived biofuels.

A GLOBAL PERSPECTIVE ON THE ENVIRONMENTAL CHALLENGES FACING THE AUTOMOTIVE INDUSTRY: STATE-OF-THE-ART AND DIRECTIONS FOR THE FUTURE

With support from the US National Science Foundation and Department of Energy, a global benchmarking study of the status of Environmentally Benign Manufacturing (EBM) has recently been completed. The study, completed under the aegis of the World Technology Evaluation Center at Loyola College in Maryland, gathered information on research and development around the world aimed at developing alternative methods for materials processing with the purpose of minimising toxic material generation and optimising products and by-products for sustainability and reuse characteristics. The study reviewed the current status of EBM research, development, and applications in the United States, Japan, and Europe with a view towards evaluating the competitive status of US efforts. Information was acquired from the technical literature as well as through visits to industry, national laboratories, universities, etc. One area of focus within the study was the automotive industry. This paper summarises many of the key findings from the global benchmarking study that relate to the automotive industry and identifies areas that require attention for the future. (A)

A model for optimizing the assembly and disassembly of electronic systems

This paper presents a methodology that incorporates simultaneous consideration of economic and environmental merit during the virtual prototyping phase of electronic product design. A model that allows optimization of a product life cycle, which includes primary assembly, disassembly, and secondary assembly using a mix of new and salvaged components, is described. Optimizing this particular life cycle scenario is important for products that are leased to customers or subject to product take-back laws. Monte Carlo simulation is used to account for uncertainty in the data, and demonstrates that high-level design and process decisions may be made with a few basic metrics and without highly specific data sets for every material and component used in a product. A web-based software tool has been developed that implements this methodology.

High level test economics advisor (Hi-TEA)

To produce high-quality and cost-effective multichip systems, they must be designed with test and fault diagnosis as critical design requirements. However, deciding on where and when to test and whether to apply Design For Test DFT) and Built-In Self-Test (BIST) at the IC, multichip module (MCM) or board level requires considerable study and evaluation to determine the economics of the various solutions and the payback. In this article we describe a tool called High Level Test Economics Advisor (Hi-TEA) that analyzes the economics of various test strategies for multichip designs at an early stage of the design cycle. The tool also allows the user to perform trade-off analysis on the impact of various cost, yield, or test effectiveness parameter on the final cost and quality of multichip designs. Experimental trade-off analysis data that were generated using the tool for some leading-edge multichip designs will also be presented.

The tradeoff between peripheral and area array bonding of components in multichip modules

This paper examines the tradeoff between peripheral I/O format die (for wirebonding, tape automated bonding (TAB), or peripheral flip chip bonding) and area array I/O format die (for flip chip bonding), as a function of partitioning a fixed functionality into a variable number of die. The comparison in this study has been made in the context of a multichip module (MCM). The analysis approach used concurrently considers module size, thermal and electrical performance, and cost (including module-level test and rework) to assess the overall applicability of one bonding format over the other. >

Life cycle inventory development for wafer fabrication in semiconductor manufacturing

Process-based, generic, parametric modules are used to manage wafer fabrication life-cycle inventory data in order to stream-line life cycle analysis activities, accommodate rapidly changing technologies, and accurately reflect the highly significant role that wafer fabrication processes have in the life cycle of an integrated circuit.

Sustainable Engineering: A Model for Engineering Education in the Twenty-First Century?

How do we design a sustainable built environment for ten billion people? What policies, economic structures and social structures will move us in this direction? These are questions that challenge contributors to and readers of this journal. They are also questions that challenge engineering educators, training the designers who will create the built environment of the twenty-first century. Engineering educators often describe their curricula with the metaphor of a toolbox. Engineering principles of mass conservation, energy conservation, and thermodynamics, to name just a few, can be viewed as powerful tools for solving problems and designing processes and products. An engineering education makes students proficient users of these tools. Yet if the toolbox is too limited, the designs created using those tools can be ineffective. To repeat an overused cliche, if the only tool you have is a hammer, everything looks like a nail. An engineering education also teaches our future designers to focus. From the earliest stages of an engineering education, students are taught to draw a ‘‘box’’ around the system to be analyzed, and to limit their attention to that boxed system. This is a necessary and powerful concept in engineering education, yet there is an increasing need to teach students to consider factors that are ‘‘out of the box’’. Engineering education needs new approaches that enlarge the box, and that give students the tools to effectively treat more complex problems, like the design of sustainable systems. How can engineering educators, practicing engineers and designers of all sorts, enlarge the box and create new tools? There are no simple answers, but offered here are some basic thoughts, using tools needed for the design of sustainable technologies as an example. As a case study of the process of enlarging the box and creating new tools for engineering design, consider the decisions surrounding how to provide personal mobility. In most of North America, personal mobility is achieved through the automobile. The choice of the automobile as the provider of personal mobility necessitates other decisions involving land use, fuel infrastructures, industrial supply chains, and societal investments in roadways. These levels of impact, associated with mobility decisions, are shown conceptually in Fig. 1. A first set of design questions (represented by the innermost layer of Fig. 1) are the choices faced by a parts engineer. In selecting the materials for a bumper/ front end, for example, the engineer could select galvanized steel or a composite, glass-reinforced plastic. Which bumper is better? Like many engineering decisions, this decision can be viewed from environmental, economic and social perspectives. The galvanized steel can be far more effectively recycled, yet the plastic composite will lead to greater fuel efficiency over the life of the vehicle. The steel bumper may be less costly to repair, resulting in different costs of ownership than the glass composite bumper. And, there may be different levels of passenger safety offered by the two materials. New analysis tools, such as environmental life cycle assessments (Curran 1996), have emerged to allow designers to address some of the multifaceted attributes of their designs. These types of analysis methods should become part of the engineer’s toolbox. The next level of questions and tools, represented by the second layer from the center in Fig. 1, considers supply chain impacts. For automobiles, how are parts manufacturers, automotive repair shops, coal producers, The authors have jointly formed the Center for Sustainable Engineering (http://www.csengin.org), which is dedicated to the development and dissemination of educational materials for incorporating concepts of sustainability into engineering curricula.

Implementation of DFE in the electronics industry using simple metrics for cost, quality, and environmental merit

This paper presents a methodology that uses simple-to-apply, narrowly-bounded (within the walls) environmental metrics and that incorporates simultaneous consideration of cost, performance, and environmental merit during the design phase of an electronic product. The examples presented demonstrate that design and process decisions may be made with only a few basic metrics and without highly specific data sets for every material and component used in a product. The benefits of using Monte Carlo simulation to account for uncertainty in the data are also shown. A web-based software tool has been developed for implementation of this methodology.

Progress on Internet-based educational material development for electronic products and systems cost analysis

The objective of this project is to build Internet-based educational materials that address the economic impact of electronic packaging technology, specifically the process of predicting the manufacturing and life cycle cost of electronic systems during their design and development process. This paper reports progress on: (1) the development and dissemination of Web-based instructional materials for use in cost analysis courses and as supplemental materials for a broad cross-section of other courses in the electronics and electronic packaging areas; and (2) the expansion of the elements within the course that address life cycle costs, particularly the concepts of life cycle assessment and design for environment. Six Internet-based modules are being developed. The modules developed include a mixture of lecture materials (in textual and video format), case studies, on-line computational tools, bibliographies, links, and discussion/homework problems. The modules are Internet-based and could be hosted by a central organization such as the IEEE.

New course development in electronic products and systems cost analysis

This paper presents a new graduate level cost analysis course that has been taught in the Mechanical Engineering Department at the University of Maryland. The objective of this course is to provide students with an in-depth understanding of the process of predicting the cost of systems. Elements of traditional engineering economics are melded with manufacturing process modeling, life cycle cost management concepts, and selected concepts from environmental life cycle cost assessment to form a practical foundation for predicting the real cost of electronic products. Various manufacturing cost analysis methods are included in the course: process-flow, parametric, cost-of-ownership, and activity based costing. The effects of learning curves, data uncertainty, test and rework processes, and defects are considered in conjunction with these methodologies. In addition to manufacturing processes, the product life cycle costs associated with design, procurement, manufacturing waste, sustainment, and end-of-life are also addressed. This course uses real life design scenarios from integrated circuit fabrication, electronic systems assembly, substrate fabrication, and testing at various levels. As a next step in the development of these educational materials, we propose to expand the involvement of industry in the course and create a set of web-based modules for use in this course, and as supplements to other courses. In addition, we will expand the elements the course addressing environmental costs, particularly the concepts of environmental life-cycle assessment (LCA) and design for environment (DFE). Simplified methodologies and metrics that demonstrate the economic impact environmental issues will be incorporated.