“…At this point, we should note that since the interphase is an altered matrix and thus there is no addition of other materials in our final model, the radii a,b,c,d of the 4 -phase model introduced in the previous Section, also appear in the proposed 7 -phase model and now have just been renamed as 1 r 3 r 5 r 7 r respectively. Hence, in the above relations we have expressed the interphase radii of the 7 -phase cylindrical model in terms of the radii b,c,d of the 4 -phase one, which does not contain any intermediate phase.…”