3Rd International Symposium on Group Five Elements, Date: MAR 22-23, 1999, Location: RIO JANEIRO, BRAZIL, Sponsors: Brazilian Catalysis Soc, Brzilian Petr Inst, Conselho Nacl Desenvolvimento Cientifico Technol, Fundacao Coordenacao Aperfeicoamento Pessoal Nivel Superior, Fundacao Amparo Pesquisa Rio Janeiro, Inst Militar Engenharia, Companhia Brasileira Mineracao & Met, Nissho Iwai