Approved

m0 ^ ACKNOWLEDGMENTS This dissertation is the culmination of an effort begun several years ago. It represents the sum total of all the encouragement, assistance, advice and expertise provided by many people in helping me to attain this goal. My committee has been most helpful during the period when it sometimes appeared that success would not be attained. Dr. Ray Clay and Dr. Herschel Mann provided support and encouragement throughout the process, and went out of their way to assist me in reaching completion. Dr. Jim Courtney joined the committee late, but he provided valuable assistance in completing the project. Drs. John Sennetti and John Burnett have served as appointed readers from the beginning and have provided most valuable suggestions for improving the product. Finally, to my wife Gradine who has constantly given encouragement and support but who has also served as editor, typist and critic, I offer my sincerest appreciation. I could not have done it without her