It has taken me almost three years to complete this book. A series of this nature and scope can only be completed through the hard work and dedication of so many people. It is very difficult to mention all of them, but we would like to congratulate the authors for their valuable contribution and are grateful to all reviewers for graciously offering their invaluable comments that have enriched the quality of the chapters in this volume and also for making available to us their valuable time and efforts. We would also like to thank Inderscience Publishers, and most sincerely, Dr. M. Dorgham and his highly professional staff (Janet Marr, Sue Omara, Jim Corlett and Edward Issac) for giving us the opportunity to publish this book. Janet Marr, in particular, has been instrumental in the successful completion of the two volumes in the series.

Finally, I would like to thank my wife, Samar and daughter, Waad, for their patience and understanding as to why I spent many long nights editing this book and e-mailing contributors around the world.