Doctoral Committee:

To my parents Sanku and Shobha, and my grandmothers Prabhavathi and Subhadra Devi for teaching me the way of life. ii ACKNOWLEDGEMENTS There are several people who have guided and supported me over the course of my journey towards a doctoral degree. I am grateful to everyone of them. I would like to thank my co-advisor Professor Dennis Assanis who has been a source of support and inspiration throughout my graduate student career. His en-gines class, ME 438, is probably the best course I have ever taken at the University of Michigan. He introduced me to engine aftertreatment catalysis through the General Motors Collaborative research labs, and I will be ever grateful for his support, trust and friendship. I would like to thank Dr. Edward Bissett, my co-advisor, for being a father away from home. I do not have enough words to describe my gratitude towards him for teaching me how to not only be a better researcher and but also a better person.