1. New Technologies—Research Centre, University of West Bohemia, Univerzitni 8, 306 14 Pilsen, Czech Republic
2. Center of Excellence Geopolymer and Green Technology, School of Material Engineering, University Malaysia Perlis, 01007 Kangar, Perlis, Malaysia
3. School of Materials Science and Technology, China University of Geosciences, Beijing 100083, People's Republic of China
4. Council of Scientific and Industrial Research—National Physical Laboratory, Dr. K S Krishnan Marg, New Delhi 110012, India and Physics Department, Indian Institute of Technology - Delhi, Hauz Khas, New Delhi 110016, India