First, I would like to thank my beloved family, especially my parents Rosa and Ednaldo, my brothers Alysson and Adrian, my grandparents Maria and Abel, my uncle Amauri (in memoriam), my aunts Socorro, Lúcia and Tânia, my cousins Emanuelle and Matheus, my sisters in law Rozalinda and Nara. They were always present in my life and taught me how the commitment to family and work make a person noble and dignified. I would deeply thank my advisor Luis Fernando (in memoriam) for given me the honor of working with him. I do not have words to truly express my immense gratitude and admiration. His excellent guidance inspired and shaped me into becoming a better researcher and person. I would like to thank my advisor Simone Barbosa for the guidance and patience. Moreover, I deeply appreciate the support she give me in a hard moment of my Phd and for suddenly accept me as an new student.