Category Materials and the Environment: Eco-Informed Material Choice

Exercises

E.1.1. Use Google to research the history and uses of one of the follow­ing materials:

■ Tin

■ Glass

■ Cement

■ Bakelite

■ Titanium

■ Carbon fiber

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Exercises

 

Present the result as a short report of about 100-200 words (roughly half a page). Imagine that you are preparing it for schoolchildren. Who used the material first? Why? What is exciting about the material? Do we now depend on it, or could we, with no loss of engineering performance or great increase in cost, live without it?

E.1.2. There is international agreement that it is desirable (essential, in the view of some) to reduce global energy consumption. Producing mate­rials from ores and feedstocks requires energy (its "embodied energy")...

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Further reading

Delmonte, J. (1985), "Origins of materials and processes", Technomic Publishing Co. ISBN 87762-420-8. (A compendium of information about materials in engineering, documenting its history.)

Kent, R. www. tangram. co. uk. TL-Polymer_Plastics_Timeline. html/. (A Website devoted to the long and full history of plastics.)

Malthus, T. R. (1798), "An essay on the principle of population", Printed for

Johnson, St. Paul’s Church-yard, London. www. ac. wwu. edu/~stephan/malthus/ malthus. (The originator of the proposition that population growth must ultimately be limited by resource availability.)

Meadows, D. H., Meadows, D. L., Randers, J. and Behrens, W. W (1972), "The limits to growth", Universe Books...

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Summary and conclusion

Homo sapiens—that means us—differ from all other species in its competence in making things out of materials. We are not alone in the ability to make: termites build towers, birds build nests, beavers build dams; all creatures, in some way, make things. The difference lies in the competence demonstrated by humans and in their extraordinary (there can be no other word) ability to expand and adapt that competence through research and development.

The timeline of Figure 1.1 illustrates this expansion. There is a ten­dency to think that progress of this sort started with the Industrial Revolu­tion, but knowledge about and development of materials have a longer and more continuous history than that...

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Materials and the environment

All human activity has some impact on the environment in which we live. The environment has some capacity to cope with this impact so that a certain level of impact can be absorbed without lasting damage. But it is clear that current human activities exceed this threshold with increas­ing frequency, diminishing the quality of the world in which we now live and threatening the well-being of future generations. Part of this impact, at least, derives from the manufacture, use, and disposal of products, and products, without exception, are made from materials.

Materials consumption in the United States now exceeds 10 tonnes per person per year. The average level of global consumption is about eight times smaller than this but is growing twice as fast...

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Learned dependency: the reliance on nonrenewable materials

Now back to the main point: the environmental aspects of the way we use materials. Use is too weak a word; it sounds as though we have a choice: use, or perhaps not use? We don’t just "use" materials, we are totally dependent on them. Over time this dependence has progressively changed from a reliance on renewable materials—the way mankind existed for thousands of years—to one that relies on materials that consume resources that cannot be replaced.

As little as 300 years ago, human activity subsisted almost entirely on renew­ables: stone, wood, leather, bone, natural fibers. The few nonrenewables— iron, copper, tin, zinc—were used in such small quantities that the resources from which they were drawn were, for practical purposes, inexhaustible...

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Materials: a brief history

Materials have enabled the advance of mankind from its earliest begin­nings; indeed, the ages of mankind are named after the dominant mate­rial of the day: the Stone Age, the Age of Copper, the Bronze Age, the Iron Age (see Figure 1.1). The tools and weapons of prehistory, 300,000 or more years ago, were bone and stone. Stones could be shaped into tools, particu­larly flint and quartz, which could be flaked to produce a cutting edge that was harder, sharper, and more durable than any other material that could be found in nature. Simple but remarkably durable structures could be built from the materials of nature: stone and mud bricks for walls, wood for beams, rush and animal skins for weather protection.

Gold, silver, and copper, the only metals that occur in native form, must have bee...

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. Introduction: material dependence

1.1 Introduction and synopsis

This book is about materials: the environmental aspects of their produc­tion, their use, their disposal at end of life, and ways to choose and design with them to minimize adverse influence. Environmental harm caused by industrialization is not new. The manufacturing midlands of 18th-century

Renewable and nonrenewable construction. Above: Indian village reconstruction. (Image courtesy of Kevin Hampton, www. wm. edu/niahd/journals.) Below: Tokyo at night. (Image courtesy of www. photoeverywhere. co. uk index.)

England acquired the nickname the "Black Country" with good reason; to evoke the atmosphere of 19th-century London, Sherlock Holmes movies show scenes of thick fog, known as "pea-soupers," swirling round the gas lamps of Baker Street...

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The CES software

The audit and selection tools developed in the text are implemented in the CES Edu 09 software, a powerful materials information system that is widely used for both teaching and design. The book is self-contained; access to the software is not a prerequisite. The software is a useful adjunct to the text, enhancing the learning experience and providing access to data for a much wider range of materials. It allows realistic selection studies that properly combine multiple constraints and the construction of tradeoff plots in the same format as those of the text.

Acknowledgments

Подпись: Xi

No book of this sort is possible without advice, constructive criticism, and ideas from others. Numerous colleagues have been generous with their time and thoughts...

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Materials and the. Environment

Michael F. Ashby

The environment is a system. Human society, too, is a system. The sys­tems coexist and interact, weakly in some ways, strongly in others. When two already complex systems interact, the consequences are hard to pre­dict. One consequence has been the damaging impact of industrial society on the environment and the ecosystem in which we live and on which we depend. Some impacts have been evident for more than a century, prompt­ing remedial action that, in many cases, has been successful. Others are emerging only now; among them, one of the most unexpected is changes in global climate that, if allowed to continue, could become very damaging.

These and many other ecoconcerns derive from the ways in which we use energy and materials...

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