References of "Lebon, Georgy"
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See detailThe role of several heat transfer mechanisms on the enhancement of thermal conductivity in nanofluids
Machrafi, Hatim ULiege; Lebon, Georgy ULiege

in Continuum Mechanics & Thermodynamics (2016), 28(5), 1461-1475

A modelling of the thermal conductivity of nanofluids based on extended irreversible thermodynamics is proposed with emphasis on the role of several coupled heat transfer mechanisms: liquid interfacial ... [more ▼]

A modelling of the thermal conductivity of nanofluids based on extended irreversible thermodynamics is proposed with emphasis on the role of several coupled heat transfer mechanisms: liquid interfacial layering between nanoparticles and base fluid, particles agglomeration and Brownian motion. The relative importance of each specific mechanism on the enhancement of the effective thermal conductivity is examined. It is shown that the size of the nanoparticles and the liquid boundary layer around the particles play a determining role. For nanoparticles close to molecular range, the Brownian effect is important. At nanoparticles of the order of 1–100 nm, both agglomeration and liquid layering are influent. Agglomeration becomes the most important mechanism at nanoparticle sizes of the order of 100 nm and higher. The theoretical considerations are illustrated by three case studies: suspensions of alumina rigid spherical nanoparticles in water, ethylene glycol and a 50/50w% water/ethylene glycol mixture, respectively, good agreement with experimental data is observed. © 2016, Springer-Verlag Berlin Heidelberg. [less ▲]

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See detailEffect of volume-fraction dependent agglomeration of nanoparticles on the thermal conductivity of nanocomposites: Applications to epoxy resins, filled by SiO2, AlN and MgO nanoparticles
Machrafi, Hatim ULiege; Lebon, Georgy ULiege; Iorio, C. S.

in Composites Science & Technology (2016), 130

A thermodynamic model for transient heat conduction in ceramic-polymer nanocomposites is proposed. The model takes into account particle's size, particle's volume fraction, and interface characteristics ... [more ▼]

A thermodynamic model for transient heat conduction in ceramic-polymer nanocomposites is proposed. The model takes into account particle's size, particle's volume fraction, and interface characteristics with emphasis on the effect of agglomeration of particles on the effective thermal conductivity of the nanocomposite. The originality of the present work is its basement on extended irreversible thermodynamics, combining nano- and continuum-scales without invoking molecular dynamics. The model is compared to experimental data using the examples of SiO2, AlN and MgO nanoparticles embedded in epoxy resin. The analysis is limited to spherical nanoparticles. The dependence of the degree of agglomeration with respect of the volume fraction of particles is also discussed and a power-law relation is established through a kinetic mechanism and experiments performed in our laboratory. This relation is used in our theoretical model, resulting into a good agreement with experiments. It is shown that the effective thermal conductivity may either increase or decrease with the degree of agglomeration. © 2016 Elsevier Ltd. [less ▲]

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See detailThermal rectifier efficiency of various bulk-nanoporous silicon devices
Machrafi, Hatim ULiege; Lebon, Georgy ULiege; Jou, D.

in International Journal of Heat & Mass Transfer (2016), 97

Our objective is to calculate and to compare the rectifying thermal coefficient of various bulk-porous silicon configurations. We consider successively homogeneous devices involving two- and three ... [more ▼]

Our objective is to calculate and to compare the rectifying thermal coefficient of various bulk-porous silicon configurations. We consider successively homogeneous devices involving two- and three elements and several graded devices characterized by variable porosity and/or size of the pores along the system. The criterion is to obtain rectifying coefficients different from one in order that thermal rectification be as efficient as possible. In that respect, it turns out that the porous-bulk-porous configurations are of little interest, in contrast to the bulk-porous-bulk systems whose rectifying coefficients may be larger than two and comparable to the values of the simpler two-element bulk-porous devices. Graded systems with either a variable porosity or a variable pore size do not exhibit better results. However, when both porosity and pore size are varying along the device, the highest efficiency is obtained. © 2016 Elsevier Ltd. All rights reserved. [less ▲]

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See detailGeneral constitutive equations of heat transport at small length scales and high frequencies with extension to mass and electrical charge transport
Machrafi, Hatim ULiege; Lebon, Georgy ULiege

in Applied Mathematics Letters (2016), 52

A generalized heat transport equation applicable at small length and short time scales is proposed. It is based on extended irreversible thermodynamics with an infinite number of high-order heat fluxes ... [more ▼]

A generalized heat transport equation applicable at small length and short time scales is proposed. It is based on extended irreversible thermodynamics with an infinite number of high-order heat fluxes selected as state variables. Extensions of Fick's and Ohm's laws are also formulated. As a numerical illustration, heat conduction in a rigid body subject to fixed and oscillatory temperature boundary conditions is discussed. © 2015 Elsevier Ltd. [less ▲]

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See detailAn extended irreversible thermodynamic modelling of size-dependent thermal conductivity of spherical nanoparticles dispersed in homogeneous media
Lebon, Georgy ULiege; Machrafi, Hatim ULiege; Grmela, M.

in Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences (2015), 471(2182),

The effective thermal conductivity of nanocomposites constituted by nanoparticles and homogeneous host media is discussed from the point of view of extended irreversible thermodynamics. This formalism is ... [more ▼]

The effective thermal conductivity of nanocomposites constituted by nanoparticles and homogeneous host media is discussed from the point of view of extended irreversible thermodynamics. This formalism is particularly well adapted to the description of small length scales. As illustrations, dispersion of Si nanoparticles in Ge (respectively, SiO2 in epoxy resin) homogeneous matrices is investigated, the nanoparticles are assumed to be spherical with a wide dispersion. Four specific problems are studied: the dependence of the effective thermal conductivity on the volume fraction of particles, the type of phonon scattering at the interface particle-matrix, the radius of the nanoparticles and the temperature. © 2015 The Author(s) Published by the Royal Society. All rights reserved. [less ▲]

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See detailThermal conductivity of tubular nanowire composites based on a thermodynamical model
Lebon, Georgy ULiege; Machrafi, Hatim ULiege

in Physica E: Low-Dimensional Systems and Nanostructures (2015), 71

A formula for the effective heat conductivity of a nanocomposite with cylindrical nanowire inclusions is derived. Both transversal and longitudinal heating along the wires are investigated. Several ... [more ▼]

A formula for the effective heat conductivity of a nanocomposite with cylindrical nanowire inclusions is derived. Both transversal and longitudinal heating along the wires are investigated. Several effects are examined: the volume fraction and sizes of the nanowires, the type of scattering at the particle-matrix interface and temperature. As illustration, silicon nanowires inclusions in a germanium matrix is considered; the results are shown to be in good agreement with other models and numerical solutions of the Boltzmann transport equation. Our main contribution consists of using extended irreversible thermodynamics to cope with the nano dimensions of the wires. © 2015 Elsevier B.V. All rights reserved. [less ▲]

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See detailEarly history of extended irreversible thermodynamics (1953-1983): an exploration beyond local equilibrium and classical transport theory
Lebon, Georgy ULiege; Jou, david

in European Physical Journal H. Historical Perspectives on Contemporary Physics (2014), 5(23),

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See detailHeat conduction at micro and nanoscales: A review through the prism of Extended Irreversible Thermodynamics
Lebon, Georgy ULiege

in Journal of Non-Equilibrium Thermodynamics (2014), 39(1), 35-59

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See detailEffective heat conduction in dispersion of wires
Behrang, Arash; grmela, miroslav; Dubois, Charles et al

in Applied Physics Letters (2014), 104

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See detailBeyond the Fourier heat conduction law and the thermal no-slip boundary condition
Lebon, Georgy ULiege; Jou, D.; Dauby, Pierre ULiege

in Physics Letters A (2012), 376(45), 2842-2846

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See detailFrom ballistic to diffusive regimes in heat transport at nano-scales
Lebon, Georgy ULiege; Grmela, Miroslav; Dubois, Charles

in Comptes Rendus de l'Académie des Sciences. Série II, Mécanique, Physique, Chimie, Sciences de l'Univers, Sciences de la Terre (2011), 339

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See detailAn extended thermodynamic model of transient heat conduction at sub-continuum scales
Lebon, Georgy ULiege; Machrafi, Hatim ULiege; Grmela, M. et al

in Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences (2011), 467

A thermodynamic description of transient heat conduction at small length and timescales is proposed. It is based on extended irreversible thermodynamics and the main feature of this formalism is to ... [more ▼]

A thermodynamic description of transient heat conduction at small length and timescales is proposed. It is based on extended irreversible thermodynamics and the main feature of this formalism is to elevate the heat flux vector to the status of independent variable at the same level as the classical variable, the temperature. The present model assumes the coexistence of two kinds of heat carriers: diffusive and ballistic phonons. The behaviour of the diffusive phonons is governed by a Cattaneo-type equation to take into account the high-frequency phenomena generally present at nanoscales. To include non-local effects that are dominant in nanostructures, it is assumed that the ballistic carriers are obeying a Guyer–Krumhansl relation. The model is applied to the problem of transient heat conduction through a thin nanofilm. The numerical results are compared with those provided by Fourier, Cattaneo and other recent models. [less ▲]

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See detailExtended Irreversible Thermodynamics
Jou, david; Casas-Vazquez, jose; Lebon, Georgy ULiege

Book published by Springer (2010)

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See detailThermodynamics of suspensions of polymeric chains in dilute solutions
Palumbo, Annunziata; Valenti, Antonino; Lebon, Georgy ULiege

in Journal of Non-Equilibrium Thermodynamics (2010), 35

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See detailVariational principles for thermal transport in nanosystems with heat slip flow
Jou, David; Lebon, Georgy ULiege; Criado-Sancho, Manollo

in Physical Review. E : Statistical, Nonlinear, and Soft Matter Physics (2010), 82

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See detailUnderstanding Non-equilibrium Thermodynamics
Lebon, Georgy ULiege; Jou, david; Casas-Vazquez, jose

Book (2008)

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See detailSecond sound and shock waves in rigid crystals: an extended thermodynamic analysis
Lebon, Georgy ULiege; Dauby, Pierre ULiege; Desaive, Thomas ULiege et al

in Proceedings of CHT-08 ICHMT International Symposium on Advances in Computational Heat Transfer (2008)

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See detailAn Extended thermodynamic approach of suspensions
Lebon, Georgy ULiege; Lhuillier, D.; Dauby, Pierre ULiege et al

in 3rd International Meeting of IEEES (2007)

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