[1] IPICYT, Adv Mat Dept, Camino Presa San Jose 2055,Col Lomas 4a Secc, San Luis Potosi 78216, Mexico
[2] Univ Autonoma San Luis Potosi, Inst Invest Comunicac Opt, Alvaro Obregon 64, San Luis Potosi 78000, Mexico
[3] IPICYT, Environm Sci Dept, Camino Presa San Jose 2055,Col Lomas 4a Secc, San Luis Potosi 78216, Mexico