Hello everyone. My name is Stephen D. Klotz. I reside in Dayton, OH. Currently, I work as a physics / math instructor and tutor. My physics specialty areas are mathematical physics, fluid dynamics, gas dynamics, thermodynamics. My mathematics specialty areas mathematical modeling, applied mathematics, partial differential equations, delayed differential equations. In addition, I am active in Science Olympiad and district, regional, state and national science fairs. I am also a freelance mathematics writer.