Rohlin flows on the Cuntz algebra O2

We prove that a quasi-free flow on O-2 has the Rohlin property if and only if the associated crossed product is purely infinite and simple and that the quasi-free flows on O-2 with the Rohlin property are cocycle conjugate with each other. The latter result also holds for any Cuntz algebra O-m with m < infinity. We also give some remarks on Rohlin Rows on a unital separable nuclear purely infinite simple C*-algebra.