1. Department of Applied Mathematics and Informatics, Faculty of Mechanical Engineering, Technical University in Košice, Letná 9, 042 00 Košice, Slovakia
2. Institute of Physics, Faculty of Sciences, P.J. Šafárik University, Park Angelinum 9, 041 54 Košice, Slovakia
3. Department of Engineering Technologies and Materials, Faculty of Mechanical Engineering, Technical University in Košice, Mäsiarská 74, 040 01 Košice, Slovakia
4. Institute of Materials Research, Slovak Academy of Sciences, Watsonova 47, 043 53 Košice, Slovakia