Acknowledgements Acknowledgments:
(First Edition, 1989): While working on this project, the author visited several institutions abroad, including Institut fuer Prozesssteuerung in der Schweissstechnik (Aachen), Institut fuer Medizinische Physik (Muenster), Institut fuer Wissenschaftliche Mikroskopie (Tuebingen), Department of Materials Science and Metallurgy (Cambridge, UK), and I wish to record my appreciation to their directors and staff for their help and collaboration. I specially want to thank Prof. Paul Drews (Aachen) and Dr. Jim Charles (Cambridge) for their kindness and hospitality during my stay and their institutions, and Dr. Ian LeMay for his help in arranging for publication.
Acknowledgment is gratefully made to Conselho Nacional de Pesquisas (Brazil), Bundesministerium fuer Forschung und Technologie (Germany) and the British Council for partial financial support of this work.
(Second Edition, 1996): In addition to those which helped for the first edition, the author acknowledges the contribution from many who have written with additional entries. I have again visited many libraries, and thank them for their hospitality. But I would like to mention particularly my appreciation to the many librarians and computer people who have made available their catalogues on the Internet. Through their very useful efforts, I have been able to visit virtually libraries all over the world. Support from the Brazilian National Research Council (CNPq) is also gratefully acknowledged.

I thank Prof.J.Pontes and P.A.Pinto Pires (UFRJ) and Dr.H.Kaker (Slovenia) (2000), and L.Ferreira and Abreu (UFRJ) (2005) for their assistance in setting up the Internet version.