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Parametryczne badanie fenomenologicznego modelu histerezy magnetycznej

Chwastek K.

Prace Instytutu Elektrotechniki

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2011

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Z. 252

41-54

PL

Przedstawiono koncepcję fenomenologicznego modelu pętli histerezy magnetycznej, spójnego z zasadami termodynamiki procesów nieodwracalnych. Poddano krytyce opis Jilesa-Athertona. Przeanalizowano wpływ zmian wartości parametrów zaproponowanego modelu na kształt pętli histerezy.

EN

A concept of a phenomenological model of hysteresis loop, compliant with the principles of non-equilibrium thermodynamics, has been presented. The Jiles-Atherton description has been criticized. An analysis of the influence of variations of model parameters on the shape of the hysteresis loop has been carried out.

2

Sound velocity and parameter of nonlinearity in the two-component relaxing mixtures

Perelomova A.

Archives of Acoustics

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2007

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Vol. 32, No. 4

871--881

EN

General formulae on small-signal sound velocity and parameter of nonlinearity B=A of a two-component relaxing mixture in the two limiting cases of very low and very high periods of sound (when the thermal equilibrium between components has enough time to establish or not) are derived. Sound parameters are expressed in the terms of partial derivatives of individual equations of state. For the two cases: the mixture of van der Waals gases and the suspension consisting of the ideal gas and tiny solid or liquid inclusions, sound velocity and parameter of nonlinearity B=A are evaluated as functions of mass concentration of one of the parts. The rst example concerns to the mixtures consisting of oxygen and helium, and the second one to the suspension of air and graphite and the water fog. General conclusions about acoustic features of the two-component mixtures under very high and low frequencies are drawn out.

3

Transverse diffraction of weakly nonlinear waves for a first order quasi-linear system involving source-like terms

Conforto F., Giambo S., Valenti G.

Journal of Technical Physics

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2004

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Vol. 45, no 1

55-69

EN

Making use of the ray theory and the method of asymptotic expansion of multiple scales, a study of the diffraction of weakly nonlinear waves in a direction transverse to the rays, through media described by dissipative or dispersive hyperbolic systems, is proposed. It is shown that the wave amplitude satisfies a generalized Zabolotskaya-Khokhlov equation in the dissipative case, or a generalized Kadomtsev-Petviashvili equation in the dispersive case. Moreover, plane, cylindrical and spherical waves are also investigated. The present approach is used to study wave diffraction in a heat-conducting fluid.

4

Analysis of Membrane Selectivity in the Pressure Driven Transport in terms of the solution-diffusion Models and Irreversible Thermodynamics

Koter S., Kujawski W.

Polish Journal of Chemistry

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2002

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Vol. 76 / nr 11

1637-1647

EN

A comparison of different models has been presented for the pressure driven stationary transport of the mixture of two liquids (1,2) through a membrane. The following models have been discussed: the solution-diffusion model (SD), modified solution-diffusions models (SDI and SDIY) and the "black-box" approach (BB) based on linear irreversible thermodynamics. The set of general equations describing separation factor (SF1/2) has been derived for each model. It has been found that if SF1/2(SD) > 1, then SF1/2(SD) > SF1/2(SDI) > SF1/2(SDIY). For the moderate pressure differences (_p = 10 bar) the SD model and its modifications (SDI, SDIY) yield SF1/2 very close to unity and cannot describe the experimental results. Contrary to them the BB approach is able to predict the experimental SF1/2. SF1/2(BB) increases with the increase of coupling between fluxes, however, its upper limit is determined by the conditions of the positive entropy production and of the positive fluxes.