The special issue of the journal Thermal Science is dedicated to fifty anniversary of the Faculty of Mechanical Engineering in Kragujevac (MFKG), Serbia. We cannot miss this opportunity to point out that Faculty owe its existence, development and today high and internationally recognized rating to its founders from the industry, government, local community, and especially to the Faculty of Mechanical Engineering in Belgrade. Professors of the Faculty of Mechanical Engineering in Belgrade with their attitude towards science and education have implemented highly sensitive gyroscope into their ancestors which is moving them toward quality and creation of well accepted results in every social and R&D context. For development of thermal science, energy and energy efficiency science at MFKG twenty years ago, and for creation of conditions for education of experts in these areas, special tribute should be made to our dear professors: Academician Zoran Zarić, Ph. D. (science advisor at Vinča Institute of Nuclear Sciences), Zoran Protić, Ph. D. (professor at Faculty of Mechanical Engineering in Belgrade), and Svetislav Stojković, Ph. D. (professor at Faculty of Mechanical Engineering in Kragujevac). Their work, humanistic and creative power have made a lift that we as their followers are using to rise and glide on science and university dome which I hope is visible in this special issue of the journal Thermal Science. In this special issue of the journal Thermal Science have been published 25 papers of the researchers from the MFKG and also from other faculties with which the Faculty, especially Department for Energy and Process Engineering, has long term successful research and educational co-operation. All the paper have been revised according to high standards of the journal Thermal Science which have brought the journal to the list of world famous journals in the area of thermal science, energy and energy efficiency science. It may be out of the ordinary, but I would like to use this occasion to emphasize that for successful development and international appearance of the Serbian researchers in the area of thermal science, energy and energy efficiency science we owe a lot to Professor Simeon Oka, Ph. D. (chief and executive editor of the journal Thermal Science) and professor Milan Radovanović, Ph. D. (president of the Society of Thermal Engineers of Serbia). Gratitude that we have is not only for their effort as researchers and creative and challenging education, but also for the founding and guidance of Thermal Science, today internationally known and appreciated science journal. This long term editing work that professor Oka and professor Radovanović nurse within the Society of Thermal Engineers of Serbia became window to world for Serbian researchers. Publishing the scientific article in the journal Thermal Science today is not only the major research event for domestic scientists but for the researchers all over the world. About excellent science and nurture characters of professor Oka and professor Radovanović is saying a lot the decision to dedicate this special issue of the journal Thermal Science to fifty anniversary of Faculty of Mechanical Engineering in Kragujevac. This decision was greeted by the employees of MFKG as a special and dear acknowledgment for their effort during fifty years long research work.