I would like to express my humble thanks to ALLAH S.W.T. for the strength, inspiration and encouragement given to me through out the completion of this thesis without any obstacles. A lot of experiences and knowledge were gained along the way.
I wished to express my sincere appreciation to my supervisors, Puan Siti Kholijah Bt Abdul Mudalip for her critics, advices, motivation, friendship and input of ideas, relentless support, guidance and endless encouragement. I also like to express my heartfelt thanks to technical staff in laboratory Puan Idayu, Encik Zulhabri, Encik Anuar, and Encik Razak, as helping to make my friends and I stay on the task concerning to the preparation and the thesis progress after all.
I am very thankful to my father, Wan Abdul Jalil Bin Wan Idris, my mother, Hashimah Bt Yusuf, family members, and all my friends for their advice and motivation. Without their endless support and interest, this thesis would not have been same as presented here. I am also indebted to University Malaysia Pahang (UMP) for giving the facilities for my research.
Lastly, I am grateful to everybody that involved directly or indirectly in helping me completing this thesis.