Erlangung des akademischen Grades

I wish to express my deep sense of thanks and gratitude to all who contributed in some way to the successful completion of this thesis. I am particularly grateful to:- First and foremost, Prof. Dr.-Ing. habil. Dr. h. c. Peter Offermann, who gave me the great honor to work my doctoral thesis under his supervision, for many fruitful discussions, ideas and his invaluable guidance and help during this research. I am very grateful for his strong interest and steady encouragement. I benefit a lot not only from his intuition and readiness for discussing problems, but also his way of approaching problems in a structured way had a great influence on me.- Prof. Dr. rer. nat. habil. Dr. h. c. Karl-Heinz Modler, Owner of the Professorship o