1. 1 Research Lab TEMI, Faculty of Science , University of Gafsa , cité Sidi Ahmed Zarroug , Gafsa Tunisia
2. 2 National Engineering School of Gabes , University of Gabes , V432+8QR Zrig Eddakhlania 6029 , Tunisia
3. 3 Institut Superieur of Technological Studies of Gafsa , University of Gafsa , Gafsa , Tunisia