A macroscopic description of geometrical pore structure of porous solids

Kubik, J.

doi:10.1016/0020-7225(86)90029-7

Cited by 31 publications

(13 citation statements)

References 4 publications

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“…1 The geometrical definition of tortuosity given above, although largely used in the literature, is not universally accepted. Discussion of the tortuosity concept, however, lays beyond the scope of this article, and we address the interested reader to the following basic papers Carman (1937), Carman (1956), Kubik (1986), Adler (1992) and Cieszko (2009).…”

Section: Introductionmentioning

confidence: 98%

Simple Expression for the Tortuosity of Porous Media

Pisani

2011

Transp Porous Med

192

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In this article, we derive a simple expression for the tortuosity of porous media as a function of porosity and of a single parameter characterizing the shape of the porous medium components. Following its value, a very large range of porous materials is described, from non-tortuous to high tortuosity ones with percolation limits. The proposed relation is compared with a widely used expression derived from percolation theory, and its predictive power is demonstrated through comparison with numerical simulations of diffusion phenomena. Application to the tortuosity of hydrated polymeric membranes is shown.

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Section: Introductionmentioning

confidence: 98%

Simple Expression for the Tortuosity of Porous Media

Pisani

2011

Transp Porous Med

192

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“…The tensor a ij , introduced by Maruszewski in [15], models the local structure of dislocations lines, which form a network of very thin lines, having the same geometrical structure of porous channels, disturbing the otherwise perfect periodicity of the crystal lattice [16] (see Fig.1). Their existence should not be omitted in the analysis of kinetic processes as diffusion of mass or charges, transport of heat and so on.…”

Section: Dislocation Dynamics Energy Flux and Non-equilibrium Thermomentioning

confidence: 99%

“…We assume that such quantity is zero in the solid-space Ω s and on the solid-area Γ s . In such a medium Maruszewski defines the so called dislocation tensor, R ij , as follows [15] (see also [16])…”

Section: Dislocation Dynamics Energy Flux and Non-equilibrium Thermomentioning

confidence: 99%

“…In [16] Kubik gives for a structure with thin channels an interpretation of R ij , considering the flux of a quantityᾱ(x) on a bulk-volume as a superposition of three one-dimensional fluxes (along three mutually perpendicular channels) having average values * α i (x, µ) on the orthogonal section areas of these channels. In [15] a new tensor, that refers R ij to the surface Γ, is defined in the following way…”

Section: Dislocation Dynamics Energy Flux and Non-equilibrium Thermomentioning

confidence: 99%

“…In Sections 3 and 4, in the framework of extended irreversible thermodynamics with internal variables (see [7], [8], [9] and [10]), a model, developed by the author, is presented for defective nanosystems (crystals with dislocations or porous channels, carbon nanotubes in a solid matrix and so on) [11], [12], [13] and [14], submitted to an external energy flux, where the internal structure is described by a dislocation tensorà la Maruszewski (see [15] and [16]) and its gradient.…”

Section: Introductionmentioning

confidence: 99%

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Non-equilibrium temperatures and heat transport in nanosystems with defects, described by a tensorial internal variable

Restuccia

2016

Communications in Applied and Industrial Mathematics

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The paper deals with the meaning of non-equilibrium temperatures in nanosystems with an internal variable, describing defects inside them, and implications on heat transport. In equilibrium all definitions of temperature lead to the same value, but in nonequilibrium steady states they lead to different values, giving information on different degrees of freedom. We discuss the caloric and entropic non-equilibrium temperatures and the relations among them, in defective nanosystems (crystals with dislocations or porous channels, carbon nanotubes in a solid matrix and so on), crossed by an external energy flux. Here, we present a model for nanocrystals with dislocation defects submitted to an external energy flux. The dislocations may have a strong influence on the effective thermal conductivity, and their own dynamics may be coupled in relevant way to the heat flux dynamics. In the linear case the constitutive relations, the rate equations for the internal variable and the heat flux are worked out and a generalized telegraphic heat equation is derived in the anisotropic and isotropic case, describing the thermal disturbances with finite velocity.

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On a Dislocation Core Tensor

Maruszewski¹

1991

Physica Status Solidi (b)

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An attempt is made that may lead to a new definition of the dislocation density field. The idea is based on the fact that dislocation cores form a kind of network of infinitesimally thin pores or capillary tubes in the crystal lattice. The main aim of the new description of the dislocation density field is focused on a way which differs from the definition based on alocal distortion field coming from lattice line defects.Es wird versucht, eine neue Definition fur das Versetzungsdichtefeld zu finden. Die Idee beruht auf der Tatsache, daR die Versetzungskerne eine Art Netzwerk von infinitesimal dunnen Poren oder Kapillarrohren im Kristallgitter bilden. Der Hauptzweck der neuen Beschreibung des Versetzungsdichtefeldes ist auf einen Weg gerichtet, der sich von der Definition auf der Grundlage eines lokalen Verzerrungsfeldes, das von Gitterliniendefekten herruhrt, unterscheidet.

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A macroscopic description of geometrical pore structure of porous solids

Cited by 31 publications

References 4 publications

Simple Expression for the Tortuosity of Porous Media

Simple Expression for the Tortuosity of Porous Media

Non-equilibrium temperatures and heat transport in nanosystems with defects, described by a tensorial internal variable

On a Dislocation Core Tensor

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