1. a Department of Chemical Engineering—PLAPIQUI, Universidad Nacional del Sur—CONICET, Camino La Carrindanga, Km 7, (8000) Bahía Blanca, Argentina.
2. b Department of Chemical Engineering—PLAPIQUI, Universidad Nacional del Sur—CONICET, Camino La Carrindanga, Km 7, (8000) Bahía Blanca, Argentina. Tel: 54-291-4861700, Ext. 265; Fax: 54-291-4861600; email: vbucala@plapiqui.edu.ar