Plugs in Viscometric Flows of Simple Semi-liquids

Here we apply the theory of simple semi-liquids in order to analyze all the viscometric flows treated in the book Viscometric Flows of Non-Newtonian Fluids by B.D.Coleman, H. Markovitz, and W. Noll, Springer-Verlag, 1966. Only simple liquids are treated in this book. When dealing with simple semi-liquids, plugs can occur. This paper gives a detailed analysis of such plugs.