Bless the Lord, O my soul: and all that is within me, bless his holy name. I give all glory to the Almighty God for the successful completion of the research programme, without HIM I am nothing. Many thanks to my supervisor, Prof. Karol Kalna for his valuable guidance and support throughout my research programme at Swansea University. Also, I would like to thank my second supervisor, Dr. Paul M. Holland, for his support and insightful discussions all through the research work. I thank my colleagues, most especially John Macaulay and members of the research group for making the research experience interesting and educative. Many thanks to the Federal Government of Nigeria and the Management of Moshood Abiola Polytechnic, Abeokuta for the opportunity availed me to undergo my research programme in Swansea University, UK. I thank especially Samson and Taiwo Folorunso, Waliu Okunade, Abiodun Olubanjo, Simeon Afonja, Gbekeleoluwa, auntie Bimple, auntie Iyabo, Taiwo and Tobi Okeneye; for all the support they have given to me throughout my period of studying in UK. I thank all my friends and siblings for your pleasant and encouraging words in the course of the research. I am very thankful to Akeem and Sola Durotoye, for your extremely support both morally and financially. My thanks also go to my parents, and my in-laws who supported me morally and spiritually. To my Kids, a big thank you for your sacrifices without complaint and keeping the flags flying while I pursued further education. Last of all, I would like to thank my wife, Oyeyinka, she has always been a blessing and a strong pillar of support. Many thanks for the words of courage during those hard moments of the research work; most importantly you freed me from family responsibilities so that I can achieve my desire goal. v To my wife and my jewel of inestimable value, Oyeyinka and my lovely kids, Oluwadarasimi, Oluwadamisi and Oluwadabira.