1. Laboratoire des Matériaux et Environnement (LAME), Ecole Polytechnique de Ouagadougou, Ouaga 03 B.P. 7021, Burkina Faso
2. Laboratory of Mathematics and Computer Science (LAMI), Department of Mathematics and Computer Science, Université Joseph Ki-Zerbo & INSEM, Ouaga 03 B.P. 7021, Burkina Faso
3. Institut Jean Lamour, CNRS UMR 7198, Université de Lorraine, Campus Artem, 2 allée André Guinier, 54000 Nancy, France