1. Subscript 0 is used for the conditions in the undisturbed gas ahead of the shock, subscript 1 indicates the conditions in the hot gas immediately behind the shock front where excitation and ionization have not yet occurred, and subscript 2 is used for the conditions in the quasi-equilibrium region.
2. Obtained by extrapolation of the curve given in T. Wentink, “High Temperature Behavior of Teflon,” Avco Research Rept. 55 (1959).