First Author:   JOAO RICARDO FARIA UNIVERSITY OF TEXAS AT EL PASO rfaria2@utep.edu         http://jockafaria.googlepages.com/home Second Author: JOAO RICARDO FARIA IPED, UNIVERSITY OF TEXAS AT EL PASO rfaria2@utep.edu   500 West University Avenue EL PASO, 79968-0703, USA   915-747-8938(Phone) 915-747-7948(Fax) http://jockafaria.googlepages.com/home