When Hitler came into power, his further career in Germany was blocked, and he accepted in 1934 the position of an associate professor at the University of Belgrade.
However, continuing political disagreement with the communist régime in Yugoslavia made him decide to accept one of the research offers in post-war Germany.
In 1953, he started lecturing at the Technische Hochschule (Technical University) in Braunschweig in Germany, becoming the head of the Department for thermodynamics and director of the Thermotechnical institute.
His research covered a very wide area: problems of exergy, evaporation, binary and multi-component systems, heat and mass transfer, combustion and gasification, high temperature plasma, solar collectors and irreversibility of energy conversion in thermodynamic processes.
His textbook Technische Thermodynamik, published in 1935 in Dresden, had seven improved and extended editions in Germany, and was translated into English (Technical Thermodynamics) and Russian (Tehnicheskaya termodinamika).