Affiliation: | Departmento de Física, Universidade Federal de Santa Catarina, Trindade, 88040-900, Florianópolis, SC, Brazil; Department of Physics and Astronomy, The Open University, Walton Hall, Milton Keyes MK7 6AA; St John's College, 1160 Camino Cruz Blanca, Santa Fe, NM 87505, USA |