One of the important aims of the editorial policy of the journal Thermal Science, is to present to worlds' scientific community the best scientific achievements in Serbian scientific institutions - faculties and institutes. Following this line, in the year 2016 with Mechanical Engineering Faculty, University of Nis, Serbia, we prepared this Supplement 5, in 20th year from foundation of the journal Thermal Science. Supplement 5, is devoted to 55th Anniversary of Mechanical Engineering Faculty in Nis. Besides papers presenting scientific achievements of the members of Faculty, in Supplement 5 are published best papers presented at the 17th Symposium of the Society of Thermal Engineers of Serbia (17th SIMTERM), organized successfully for the 6th time by Faculty. Prof. Mladen Stojiljković, as Guest Editor, and also as Chairman of the Organizing Committee of the 17th SIMTERM, made an excellent mix of the papers written specially for this issue by academic staff of the Faculty, and presented at the 17th SIMTERM. Selected papers give good insight in wide scope of scientific topics and engineering problems having been investigated in last 5 years at Mechanical Engineering Faculty in Nis. I am greatly thankful to Prof. Mladen Stojiljković, for excellent paper selection, showing that thermal processes are present and critical in different engineering devices and systems. Scope of the problems treated in papers published in this Supplement 5, show that it is possible to orient fundamental and applied research to solve important problems in industry and economy specific for each country, but important also to improve overall knowledge about physical and chemical processes in nature and engineering.