The present work has two purposes. The first one is didactic. It intend to present many versions of the Continuun Thermodynamics discussing their resemblances and diferences. Many forms of the second law are presented and in some cases their supposed generalities are questioned. The second purpose lies on the basic research. It is carried out applying the Serrin s version the concepts of Thermodynamic Stability and Availability in the studied of the Carnot s and Rankine s cycles. By meaning of the accumulation function concept a newform to determine the efficience of the above cycles is introduced. On the other hand in the Serrin s version the theory of transition processes can be applied in the study of the Joule-Thomson effect. The working fluids are an ideal gas which is characterized by the convexity of it s state space and the Van der Waals fluid which is not provided of such characteristic. Finally in the context of the Irreversible Thermodynamics is made a comparison between the solutions of heat conduction problems in rigid and linear isotropic elastic continuum.