First Author:   Essosinam Franck Karabou University of Kara kfranck2008@gmail.com   kfranck2008@gmail.com GLEKODZI, Togo   +22893973912(Phone) +22893973912(Fax) Second Author: Komlan Ametowoyo Adeve University of Kara fadeve@yahoo.fr     +22890138857(Phone)