Mechanical and Aerospace Engineering - 1960 Smetana, F. O. (1960). Studies in the heating of a supersonic gas stream by a radio frequency discharge. Air Force Office of Scientific Research (AFOSR), TN 60-648(June). Epstein, M., Waiter, S. A., Smetana, F. O., & Williams, J. C., III. (1960). Properties of the plasma sheath and its effects on the transmission of electromagnetic waves. USCEC Report, 85-101(April).