Affiliation: | 1. Applied Physics Section of Environ. Sci. Dept., Universitat de Lleida, Av. Jaume II, 69, 25001 Lleida, Spain;2. Departament de Matemàtica, Universitat de Lleida, Av. Jaume II, 69, 25001 Lleida, Catalonia, Spain;1. Department of Physics, Indian Institute of Technology Roorkee, Roorkee 247667, Uttarakhand, India;2. School of Physical Sciences, Indian Association for Cultivation of Science, Kolkata 700032, West Bengal, India |