DEDICATION

This dissertation is dedicated to the following people:

• the memory of my mother, K. Visalakshy, who emphasized the importance of education and helped me with my lessons throughout her life.

• my father, G. Purushothaman, who has been my role-model for hard work, persistence and personal sacrifices, and who instilled in me the inspiration to set high goals and the confidence to achieve them.

• my sisters--Dr. P. V. Divya, Devi Vysala and Anupriya Vysala--who have been my emotional anchors through not only the vagaries of graduate school, but my entire life.

• my husband, Josyula R. Rao, who has been proud and supportive of my work and who has shared the many uncertainties, challenges and sacrifices for completing this dissertation.

• my son, Ananth J. Josyula, who has grown into a wonderful 3 year old in spite of his mother spending so much time away from him working on this dissertation.