I would like to thank my supervisors A and B. This thesis would not have been completed without their support and guidance. A has always been encouraging my research. His insightful advice and ideas about my research and scientific writing have been invaluable. B has also been very supportive and provided insightful discussions and suggestions about the research. I am lucky to have them as my mentors.

I also thank my thesis committees for serving my committee members.

I am deeply grateful to my family, for their remarkable and unconditional support. I am veryextremely lucky to have them in my life.

My graduate research has received financial supportssupport from many sources, including
NSERC and OGS. I am grateful for having thesethis funding during my graduate program.