Institution: | 1.Institute of Geosciences and Exact Sciences (IGCE), S?o Paulo State University (Unesp), 1515 24-A Avenue, Rio Claro, SP, 13506-900, Brazil ;2.Observatório do Valongo, Universidade Federal do Rio de Janeiro, Ladeira do Pedro Ant?nio 43, 20080-090, Rio de Janeiro, Brazil ;3.Physics Program - IGCE/Unesp, Rio Claro, Brazil ; |