Several people are involved in the process of elaborating on this thesis, and each one has a unique contribution. First of all, I would like to thanks my advisor Prof. Márcio Garcia, for the excellent guidance, friendship, and advice, which were very important in my formation. I also thank Prof. Marcelo Medeiros and Marcos Chamon for important comments, suggestions, and insights. During my time at PUC, I appreciated the classes of the professors Marcelo Medeiros, Fábio Miessi, Ruy Ribeiro, Eduardo Zilberman, and Marcelo de Paiva Abreu. It was a privilege to spend some time listening and absorbing part of your knowledge. This project would not be possible without the support of my family, my parents Mauro and Rita, my sister Sofia, and my grandparents, Mauro and Maria. Finally, I am very grateful to all my friends and my classmates. My period in Rio would not be the same without your friendship. This study was partially financed by the Coordenação de Aperfeiçoamento Pessoal de Nível Superior-Brasil (CAPES)-Código de Financiamento 001. I also thanks the CNPq for the financial support.