“…Of these, Squire (1970Squire ( , 1978 has eliminated the swollen molecular volume, V, by combining simultaneously the harmonic mean rotational relaxation time ratio, Th/ro, with the translational frictional ratio, f/fo: Perrin (1934Perrin ( , 1936 with a correction for the relaxation-time ratios given by Koenig (1975). The corresponding variation of as a function of axial ratio could thus be evaluated (Squire, 1970).…”