Acknowledgement

I would like to take this opportunity to express my sincere gratitude to my advisor Dr. Mashood Olawale Fadeyi for the continuous support, motivation and patience. This master’s dissertation would not have been possible without his guidance, dedication, and unsurpassed knowledge. Another special thank you to my mom for the ongoing courage and motivation. Last, but by no mean least, I thank all my relatives, friends, and colleagues for all the encouragement and the support.