Author(s):
1. Vladimir Čavić, Banjalučka pivara, Republic of Srpska, Bosnia and Herzegovina
2. Mirko Dobrnjac, Faculty of Mechanical Engineering, Republic of Srpska, Bosnia and Herzegovina
3. Jela Burazer, Institut Goša, Milana Rakića 35, Beograd, Serbia
4. Milan Lečić, Univeristy of Belgrade, Faculty of Mechanical Engineering, Serbia

Final paper