I ACKNOWLEDGMENTS
Firstly, I would like to express my sincere gratitude my supervisor Prof. Fernando Secco for his supports, advises and valuable guidance
throughout my PhD study.I am greatful to Prof. Marcella Venturini who has been always very kind and supportive in all matters. This thesis would not have been possible unless them.
I also would like to thank Dr. Tarita Biver for being always friendly and her valuable helps during this work.
I must also acknowledge Prof. Hunay Evliya for her concern and encouragement.
I am also greatful to following colleagues for their friendship : Maria Rosa, Nurettin, Clara, Luisa, Elisa, Elia, Marina, Natalia and Tommaso.They never let me fell alone.
I would like to thank also Antonio for his positive energy and encouragement.
Finally, a special thanks to my family, my mother, my father and my sisters Neslihan and Fatma for always being beside me without their constant supports i would not have been able do nothing. I appreciate of their uncondutional love and their presence.
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