Messanae Universitas Studiorum

Non equilibrium thermodynamics with internal variables in Kluitenberg's theory

Ciancio, Vincenzo (2005) Non equilibrium thermodynamics with internal variables in Kluitenberg's theory. In: Thermal theories of continua: survey and delelopments, 25-30 Sep 2005, Messina, Italy.

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    Abstract

    We show a method to verify experimentally some inequalities which occur for phenomenological coefficients in the thermodynamical model for dielectric relaxation and viscoanelastic media developed in the ambit of non-equilibrium thermodynamic Kluitenberg's theory. In particular, for dielectric relaxation we assume a sinusoidal form for induction vector (extensive variable: cause), the electric field (intensive variable: effect) inside the system, which depends on unknown phenomenological coefficients, has been obtained by integration. Then we compare it with a similar form of the electric field obtained by experimental considerations, where well known experimentally determinable coefficients appear. We carry out dielectric measurements on PMMA and PVC at different frequencies and fixed temperature in order to obtain the phenomenological coefficients as functions of the frequency. For viscoanelastic media we consider the relative rheological equation and we compare the solution of this equation with a well known expression of the stress obtained, by experimentally considerations, in the linear response theory. This comparison will be able to determine the phenomenological an state coefficients as function of frequency dependent quantities experimentally measurable. This method will be applied to polymeric materials as Polyisobutilene.

    Item Type: Conference or Workshop Item (Paper)
    Subjects: M.U.S. - Contributi Scientifici > 02 - Scienze fisiche
    M.U.S. - Miscellanea > Atti Accademia Peloritana > Classe di Scienze Fisiche, Matematiche e Naturali
    Divisions: UNSPECIFIED
    Depositing User: Mr Nunzio Femminò
    Date Deposited: 07 Aug 2008
    Last Modified: 13 Apr 2010 13:16
    URI: http://cab.unime.it/mus/id/eprint/484

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