This book is the fruit of the author¿s six years of research and fieldwork undertaken while at the Centre for Sustainable Development Research and Interdisciplinary Studies¿Troyes University of Technology. The research and field work were concentrated on material and energy flow loops, the principal tool that industrial ecology puts forward in order to limit environmental and economic impacts caused by the abuse of natural resources. The book is aimed at those responsible for providing a bit of substance to the objective of sustainable development. It also aims to disseminate this information towards future caretakers of the planet who today occupy seats at universities.