1. Department of Chemical and Biological Engineering, ISEC; Polytechnic Institute of Coimbra; R. Pedro Nunes 3030-199 Coimbra Portugal
2. GEPSI, CIEPQPF, Department of Chemical Engineering; University of Coimbra; R. Sílvio Lima, Pólo II 3030-790 Coimbra Portugal
3. Department of Biostatistics; Fielding School of Public Health, UCLA; 10833 Le Conte Ave. Los Angeles CA 90095-1772 USA