Dietrich Luetzow is manager of the urea plant at BASF AG, Ludwigshafen, Germany. He joined BASF in 1955 after receiving M.S. and Ph.D. degrees in chemistry from Munich University. For the first fourteen years of his period of employment he worked in research and as manager of different fertilizer plants.
G. Hemmer is chemical engineer in the technical research and development division of BASF-Ludwigshafen (W.-Germany). He holds a B.S. in mechanical engineering. He is now specialized on combustion and safety engineering.