[1] LSCP, Department of Chemical Engineering, Polytech. Sch. of Univ. of Sao Paulo, Av. Prof. Luciano Gualberto, trav. 3, São Paulo, SP CEP 05508-900, Brazil
[2] Laboratory of Automation and Control, Dept. Telecommunications/Contr. Eng., Polytech. Sch. of Univ. of Sao Paulo, Av. Prof. Luciano Gualberto, trav. 3, São Paulo, SP CEP 05508-900, Brazil