1. Universidade de São Paulo-Escola Politécnica, Department of Chemical Engineering, Av. Prof. Luciano Gualberto travessa 3, no. 380, Cidade Universitária, 05508-010 São Paulo, SP Brazil
2. Bio & Materials Laboratory, Polytechnic School, National University of Asuncion, 111421 San Lorenzo, P.O. Box 2111, SL Paraguay