title: Comment on "Maximum or minimum entropy production? How to select a necessary criterion of stability for a dissipative fluid or plasma".
abstract: In a recent paper, Phys. Rev. E 81, 041137 (2010), the author attempts to derive ten necessary conditions for the stability of dissipative fluids and plasmas. Assuming the validity of the local equilibrium principle, these criteria have been obtained solely from the first and second laws of thermodynamics. The Onsager reciprocity relations have not been invoked, and the author's results are supposed to be valid independent of the choice of the boundary conditions. In the present Comment, in agreement with the general theory established by Glansdorff-Prigogine in 1954 and 1970, we show that there is no variational principle expressing the necessary conditions for the stability of dissipative systems involving convective effects when the system is out of the Onsager region. In particular, we prove that the basic equations constituting the starting point of the analysis of the author, attempting to derive ten necessary conditions for the stability involving magnetohydrodynamical effects, are incorrect and in contradiction with the laws of the thermodynamics of irreversible processes.
authors.affiliation: Department of Theoretical Physics and Mathematics, Université Libre de Bruxelles (ULB), Campus de la Plaine Code Postal 231, Boulevard du Triomphe, Brussels 1050, Belgium. gsonnino@ulb.ac.be
authors.forename: Giorgio
authors.initials: G
authors.lastname: Sonnino
authors.forename: Mustapha
authors.initials: M
authors.lastname: Tlidi
authors.forename: Jarah
authors.initials: J
authors.lastname: Evslin