1. Departament de Mineralogia, Petrologia i Geologia Aplicada, Universitat de Barcelona, 08007 Barcelona, Spain
2. Department of Physics, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
3. Graduate School of Human and Environmental Studies, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
4. Faculty of Applied Biological Science, Hiroshima University, Higashi-Hiroshima 739-8528, Japan
5. Graduate School of Advanced Science and Engineering, Hiroshima University, Higashi-Hiroshima 739-8521, Japan