Ing. Kristína Gerulová, PhD., Ing. Ondrej Tatarka, Ing. Tomáš Štefko, Ing. Tomáš Škulavík, PhD. Slovak University of Technology in Bratislava, Faculty of Materials Science and Technology in Trnava, Institute of Safety, Environment and Quality, Paulínska 16, 917 24 Trnava, Slovak Republic