1. Faculty of Engineering, May University in Cairo, Cairo 14531, Egypt
2. Laboratory of Organic Matter Physics, University of Nova Gorica, SI-5000 Nova Gorica, Slovenia
3. Department of Physics, The American University in Cairo, Cairo 11835, Egypt
4. Karst Research Institute, Research Centre of the Slovenian Academy of Sciences and Arts, SI-6230 Postojna, Slovenia
5. UNESCO Chair on Karst Education, University of Nova Gorica, SI-5000 Nova Gorica, Slovenia
6. Materials Research Laboratory, University of Nova Gorica, SI-5000 Nova Gorica, Slovenia