1. Institute of Geotechnics, Slovak Academy of Sciences, Watsonova 45, 04001 Košice, Slovakia
2. Center of Physical–Chemical Methods of Research and Analysis, Al-Farabi Kazakh National University, Tole bi 96A, 050012 Almaty, Kazakhstan
3. Federal Research Institute for Materials Testing, Richard-Wiltstätter Strasse 11, 12489 Berlin, Germany
4. Institute of Materials Research, Slovak Academy of Sciences, Watsonova 47, 04001 Košice, Slovakia