1. Centre de Recherche Scientifique et Technique en Analyses Physico‐Chimiques BP 384, Zone Industrielle, Bou‐Ismail CP 42004 Tipaza Algeria
2. Macromolecular Research Laboratory, Faculty of Sciences Abou Bekr Belkaid University P.O. Box 119 Tlemcen Chetouane Algeria
3. Laser Department/Nuclear Research Centre of Algiers (CRNA) 02 Boulevard Frantz Fanon, P.O. Box. 399 Algiers Algeria