Abstracts of papers for

Previous issue vol. 47, no. 1 (2006)

vol. 47, no. 2 (2006)

Next issue vol. 47, no. 3 (2006)

Contents of issue 2, vol. 47

1. S.K. Roy Choudhuri: Magneto-thermo-elastic waves in an infinite perfectly conducting solid without energy dissipation
2. D. Rogula and M. Sztyren: Long-range Josephson couplings in superconducting systems
3. Z. Śloderbach and Z. Rechul: A thermodynamic approach to the stored energy concept
4. Z.J. Zawistowski: Invariance of integro-differential equations with moving region of integration

S.K. Roy Choudhuri: Magneto-thermo-elastic waves in an infinite perfectly conducting solid without energy dissipation

The generalized theory of Thermoelasticity II without energy dissipation is employed to study the propagation of time-harmonic plane waves in an unbounded, perfectly electrically conducting elastic medium subjected to a primary uniform magnetic field. A more general dispersion equation for coupled magneto-thermoelastic waves is derived. It reveals that the coupled magneto-thermoelastic waves correspond to modified dilatational and thermal waves propagation with finite speeds modified by finite thermal wave speed, thermoelastic coupling and the external magnetic field. The waves propagate without attenuation and dispersion in contrast to the magneto-thermoelastic waves in classical thermoelasticity and in other generalized thermoelastic theories where the coupled waves undergo both attenuation and dispersion. Numerical results for a copper-like material are presented.

Key words: magneto-thermoelastic waves, thermoelasticity without dissipation.

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D. Rogula and M. Sztyren: Long-range Josephson couplings in superconducting systems

Microstructured superconductors with long-range Josephson couplings are considered. The higher-grade hybrid model of layered superconductors is generalized to other microstructural geometries. The effects of broken symmetry with respect to the time reversal are described with the aid of complex Josephson coupling constants. This formalism is applied to the discussion of stability of the uniform, alternating, and phase-modulated states of a layered superconductor.

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Z. Śloderbach and Z. Rechul: A thermodynamic approach to the stored energy concept

The paper presents a generalized thermodynamic model of a medium with isotropic hardening characteristics. A special form of the free energy was derived for a thermoplastic material undergoing isotropic hardening. The classical thermodynamics of irreversible processes with the involved material being characterized by macroscopic internal parameters was used in the derivation. The energy form mentioned may be used for practical determining the level of stored energy accumulated during plastic-working processes applied to power industry components. The existing models of energy storage are critically discussed and compared with the latest experimental evidence.

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Z.J. Zawistowski: Invariance of integro-differential equations with moving region of integration

General criterion of invariance of integro-differential equations under the Lie symmetry group of point transformations is derived. It is a generalization of the previous form of the criterion to the case of a moving range of integration. This is the situation when a region of integration depends on external, with respect to integration, variables what leads to its explicit dependence on a group parameter, so the region of integration moves under symmetry transformations. General case of dependence on independent and dependent variables and their derivatives is considered.

Key words: symmetry, integro-differential equations, Lie groups.

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