I would like to express my deep and sincere gratitude to many people who made this Ph.D. thesis possible. Special thanks are due to my advisor, Dr. Xiangyang Zhou, for accepting me as his Ph.D. student, for his insight resolving the problems encountered throughout research and thesis writing, and his invaluable comments during my graduate study. I would like to thank Dr Azzam Mansour and Naval Research Laboratory. In addition I would like to thank all of my Ph.D. committee members, Dr. Hongtan Liu, Dr. Na Li and Dr. Chenzhong Li. I would like to thank the Department of Mechanical and Aerospace Engineering and the Graduate school at University of Miami for financial support. I would like to thank my very good friend Juanjuan Zhou, who has been a great colleague through the last two years but an even better friend. The quality of my dissertation benefited greatly from our long thought provoking conversations as well as from our friendship. Many thanks to all the other group membersfrom clean energy Lab. I would like to thank all of my family and friends who have supported me for the last three years on this great journey that has been my Ph. D.