I would like to express my sincere gratitude to my supervisor, Prof. Changcheng Huang, for his support, guidance, and encouragement. It is my privilege to have a great opportunity to work with him. His invaluable advice and patient guidance help me how to conduct a scientific research, and explore new research topics independently. He consistently motivates me to do my best, or encourages me when I have a challenging time during research. His profound supervision pushes me beyond my expectations. I would have never been able to accomplish my dissertation without his tremendous support.During the long journey of a PhD student, it has been a great pleasure to work with faculty, staff, alumni, colleagues and students at Carleton University. I would like to thank Qiao Lu, Steve Drew, Pei Jin, Hieu Le and other colleagues in laboratory for their support, precious advice and stimulating discussions on my work.Finally, I would like to appreciate the unconditional support, patience and encouragement from my wife Trang Pham, my daughter Helen Nguyen, our families, Tung Pham, Tin Vo and other friends throughout my PhD journey.