I am deeply grateful and indebted to Prof. Dr. Jürgen Hahn, Professor of Agricultural Engineering, Faculty of Agriculture and Horticulture, Humboldt University, Berlin, Germany, for his kind academic supervision, valuable advice and suggestions contributing to the success of this work.

My sincere thanks, full respect and deep gratitude go to Dr.-Ing. Volkhard Scholz, responsible for New and Renewable Energy at the Institute of Agricultural Engineering (ATB), Bornim, Germany, for his patient supervision, inspiring guidance, critical comments, suggestions, and the never-ending support he displayed throughout this study. Additionally, I wish not only to acknowledge his outstanding academic supervision, but also to express my grateful appreciation of his contributions and his support in various private matters during my stay in Germany.

Many deep thanks are due to Prof. Dr.-Ing. Klaus Nendel and Dr.-Ing. Brit Clauß of the Institute of Mechanical Engineering and Plastic Technology, Technological University Chemnitz, for their valuable academic advice and support.

My deepest thanks and appreciation also go to the energy team in the Department of Post-Harvest Technology at the ATB for their tremendous assistance and efforts, especially to Dipl.- Ing. (FH) Peter Kaulfuß, Dipl.-Ing. (FH) Ralf Zitzmann and Mr. Erhard Brand.

This work has been successfully completed thanks to the family-like and friendly atmosphere created by all the members of the ATB. In this connection my gratitude extends especially to Prof. Dr.-Ing. Jürgen Zaske, Director of the Institute, Prof. Dr. habil Christian Fürll, Head of the Department of Post-Harvest Technology, Dr. Philip Grundmann, Doctor of Agricultural Economics, and Dipl.-Ing. Wolfgang Schwarz, computer administrator in the Department of Post-Harvest Technology at ATB for their fruitful cooperation.

I am also grateful to Prof. Dr. Gamal Abo El Ghar, Department of Insects, Faculty of Agriculture, El Menoufiya University, Egypt, for his academic suggestions and support.

My sincere thanks, and deep gratitude are due to Mrs. Renate Lauterborn, Diabetics Adviser, Charité Hospital Berlin (Campus Virchow-Klinikum) for her continuous help and strong and never-ending support through and after the illness of my daughter.

My sincere thanks and gratitude to Prof. Dr. Nagiba El Ghamrawy, Ex-Culture Consul and Prof. Dr. Alya Khattab, Culture Consul of the Egyptian Embassy in Germany, for their encouragement and support throughout my studies in Germany. Thanks are also extended to all the Egyptian and German members of the Culture Department and students mission of the Egyptian Embassy in Germany for their friendly cooperation and support.

Last but not the least, I would like to express my deep thanks and appreciation to my great parents, my dear wife and my lovely daughters Radwa and Rowaida, the source of my happiness, encouragement and motivation. I therefore, dedicate this thesis to them.

Ehab Abd El Aziz El Seaidy