[1] Univ Puerto Rico, Dept Chem, Rio Piedras Campus, Rio Piedras, PR 00925 USA
[2] Univ Sonora, Dept Ingn Quim & Met, Hermosillo 83000, Sonora, Mexico
[3] Texas A&M Univ, Dept Nucl Engn, College Stn, TX 77843 USA
[4] Univ Texas El Paso, Dept Chem & Biochem, El Paso, TX 79968 USA