Special Issue "Selected Papers from 15th Joint European Thermodynamics Conference"

A special issue of Entropy (ISSN 1099-4300). This special issue belongs to the section "Thermodynamics".

Deadline for manuscript submissions: closed (31 October 2019).

Special Issue Editors

Prof. Dr. Miguel Rubi
E-Mail Website
Guest Editor
University of Barcelona, Department of Condensed Matter Physics, Diagonal 647, 08028 Barcelona, Spain
Interests: non-equilibrium thermodynamics; non-equilibrium statistical physics; thermodynamics of small systems; heat exchange at the nanoscale; Casimir forces; diffusion in confined systems; small biological systems; non-equilibrium self-assembly
Special Issues and Collections in MDPI journals
Dr. F. Xavier Alvarez
E-Mail Website
Guest Editor
Universitat Autònoma de Barcelona, Physics Department, Edifici C, Campus Bellaterra, 08193 Bellaterra, Spain
Interests: non-equilibrium thermodynamics; nanoscale heat transport; phonon transport; thermoelectricity
Dr. Daniel Campos
E-Mail
Guest Editor
Universitat Autònoma de Barcelona, Physics Department, Edifici C, Campus Bellaterra, 08193 Bellaterra, Spain
Interests: stochastic processes; reaction diffusion systems; biological systems; movement ecology

Special Issue Information

Dear Colleague,

The JETC conferences were established in 1989 under the name “Journées Européennes de Thermodynamique Contemporaine”, by ECAST, the European Center for Advanced Studies in Thermodynamics.

As it was desirable to enlarge the scope of the conferences, and in order to unite thermodynamics across Europe, the conferences changed its name in 2007 to the “Joint European Thermodynamics Conference”, while the acronym remained the same.

The scope of the conference is rather broad, and covers the methods and concepts of equilibrium and non-equilibrium thermodynamics in all branches of physics, engineering, sciences, and humanities.

Prof. Miguel Rubi
Dr. F. Xavier Alvarez
Dr. Daniel Campos
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Entropy is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • quantum thermodynamics
  • thermodynamics of small systems
  • biothermodynamics
  • engineering thermodynamics
  • gravitation and thermodynamics
  • thermodynamics of turbulence
  • thermodynamics and networks
  • theories of nonequilibrium thermodynamics

Published Papers (7 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Open AccessArticle
Fractal-Like Flow-Fields with Minimum Entropy Production for Polymer Electrolyte Membrane Fuel Cells
Entropy 2020, 22(2), 176; https://doi.org/10.3390/e22020176 - 04 Feb 2020
Cited by 1 | Viewed by 895
Abstract
The fractal-type flow-fields for fuel cell (FC) applications are promising, due to their ability to deliver uniformly, with a Peclet number Pe~1, the reactant gases to the catalytic layer. We review fractal designs that have been developed and studied in experimental prototypes and [...] Read more.
The fractal-type flow-fields for fuel cell (FC) applications are promising, due to their ability to deliver uniformly, with a Peclet number Pe~1, the reactant gases to the catalytic layer. We review fractal designs that have been developed and studied in experimental prototypes and with CFD computations on 1D and 3D flow models for planar, circular, cylindrical and conical FCs. It is shown, that the FC efficiency could be increased by design optimization of the fractal system. The total entropy production (TEP) due to viscous flow was the objective function, and a constant total volume (TV) of the channels was used as constraint in the design optimization. Analytical solutions were used for the TEP, for rectangular channels and a simplified 1D circular tube. Case studies were done varying the equivalent hydraulic diameter (Dh), cross-sectional area (DΣ) and hydraulic resistance (DZ). The analytical expressions allowed us to obtain exact solutions to the optimization problem (TEP→min, TV=const). It was shown that the optimal design corresponds to a non-uniform width and length scaling of consecutive channels that classifies the flow field as a quasi-fractal. The depths of the channels were set equal for manufacturing reasons. Recursive formulae for optimal non-uniform width scaling were obtained for 1D circular Dh -, DΣ -, and DZ -based tubes (Cases 1-3). Appropriate scaling of the fractal system providing uniform entropy production along all the channels have also been computed for Dh -, DΣ -, and DZ -based 1D models (Cases 4-6). As a reference case, Murray’s law was used for circular (Case 7) and rectangular (Case 8) channels. It was shown, that Dh-based models always resulted in smaller cross-sectional areas and, thus, overestimated the hydraulic resistance and TEP. The DΣ -based models gave smaller resistances compared to the original rectangular channels and, therefore, underestimated the TEP. The DZ -based models fitted best to the 3D CFD data. All optimal geometries exhibited larger TEP, but smaller TV than those from Murray’s scaling (reference Cases 7,8). Higher TV with Murray’s scaling leads to lower contact area between the flow-field plate with other FC layers and, therefore, to larger electric resistivity or ohmic losses. We conclude that the most appropriate design can be found from multi-criteria optimization, resulting in a Pareto-frontier on the dependencies of TEP vs TV computed for all studied geometries. The proposed approach helps us to determine a restricted number of geometries for more detailed 3D computations and further experimental validations on prototypes. Full article
(This article belongs to the Special Issue Selected Papers from 15th Joint European Thermodynamics Conference)
Show Figures

Figure 1

Open AccessArticle
Ballistic-Diffusive Model for Heat Transport in Superlattices and the Minimum Effective Heat Conductivity
Entropy 2020, 22(2), 167; https://doi.org/10.3390/e22020167 - 31 Jan 2020
Cited by 5 | Viewed by 685
Abstract
There has been much interest in semiconductor superlattices because of their low thermal conductivities. This makes them especially suitable for applications in a variety of devices for the thermoelectric generation of energy, heat control at the nanometric length scale, etc. Recent experiments have [...] Read more.
There has been much interest in semiconductor superlattices because of their low thermal conductivities. This makes them especially suitable for applications in a variety of devices for the thermoelectric generation of energy, heat control at the nanometric length scale, etc. Recent experiments have confirmed that the effective thermal conductivity of superlattices at room temperature have a minimum for very short periods (in the order of nanometers) as some kinetic calculations had anticipated previously. This work will show advances on a thermodynamic theory of heat transport in nanometric 1D multilayer systems by considering the separation of ballistic and diffusive heat fluxes, which are both described by Guyer-Krumhansl constitutive equations. The dispersion relations, as derived from the ballistic and diffusive heat transport equations, are used to derive an effective heat conductivity of the superlattice and to explain the minimum of the effective thermal conductivity. Full article
(This article belongs to the Special Issue Selected Papers from 15th Joint European Thermodynamics Conference)
Show Figures

Figure 1

Open AccessArticle
Thermodynamics of Tower-Block Infernos: Effects of Water on Aluminum Fires
Entropy 2020, 22(1), 14; https://doi.org/10.3390/e22010014 - 20 Dec 2019
Cited by 1 | Viewed by 980
Abstract
We review the thermodynamics of combustion reactions involved in aluminum fires in the light of the spate of recent high-profile tower-block disasters, such as the Grenfell fire in London 2017, the Dubai fires between 2010 and 2016, and the fires and explosions that [...] Read more.
We review the thermodynamics of combustion reactions involved in aluminum fires in the light of the spate of recent high-profile tower-block disasters, such as the Grenfell fire in London 2017, the Dubai fires between 2010 and 2016, and the fires and explosions that resulted in the 9/11 collapse of the World Trade Center twin towers in New York. These fires are class B, i.e., burning metallic materials, yet water was applied in all cases as an extinguisher. Here, we highlight the scientific thermochemical reasons why water should never be used on aluminum fires, not least because a mixture of aluminum and water is a highly exothermic fuel. When the plastic materials initially catch fire and burn with limited oxygen (O2 in air) to carbon (C), which is seen as an aerosol (black smoke) and black residue, the heat of the reaction melts the aluminum (Al) and increases its fluidity and volatility. Hence, this process also increases its reactivity, whence it rapidly reacts with the carbon product of polymer combustion to form aluminum carbide (Al4C3). The heat of formation of Al4Cl3 is so great that it becomes white-hot sparks that are similar to fireworks. At very high temperatures, both molten Al and Al4C3 aerosol react violently with water to give alumina fine dust aerosol (Al2O3) + hydrogen (H2) gas and methane (CH4) gas, respectively, with white smoke and residues. These highly inflammable gases, with low spontaneous combustion temperatures, instantaneously react with the oxygen in the air, accelerating the fire out of control. Adding water to an aluminum fire is similar to adding “rocket fuel” to the existing flames. A CO2–foam/powder extinguisher, as deployed in the aircraft industry against aluminum and plastic fires by smothering, is required to contain aluminum fires at an early stage. Automatic sprinkler extinguisher systems should not be installed in tower blocks that are at risk of aluminum fires. Full article
(This article belongs to the Special Issue Selected Papers from 15th Joint European Thermodynamics Conference)
Show Figures

Figure 1

Open AccessArticle
Nonlinear Heat Transport in Superlattices with Mobile Defects
Entropy 2019, 21(12), 1200; https://doi.org/10.3390/e21121200 - 06 Dec 2019
Cited by 1 | Viewed by 737
Abstract
We consider heat conduction in a superlattice with mobile defects, which reduce the thermal conductivity of the material. If the defects may be dragged by the heat flux, and if they are stopped at the interfaces of the superlattice, it is seen that [...] Read more.
We consider heat conduction in a superlattice with mobile defects, which reduce the thermal conductivity of the material. If the defects may be dragged by the heat flux, and if they are stopped at the interfaces of the superlattice, it is seen that the effective thermal resistance of the layers will depend on the heat flux. Thus, the concentration dependence of the transport coefficients plus the mobility of the defects lead to a strongly nonlinear behavior of heat transport, which may be used in some cases as a basis for thermal transistors. Full article
(This article belongs to the Special Issue Selected Papers from 15th Joint European Thermodynamics Conference)
Show Figures

Figure 1

Open AccessArticle
Thermodynamics of Gas–Liquid Colloidal Equilibrium States: Hetero-Phase Fluctuations
Entropy 2019, 21(12), 1189; https://doi.org/10.3390/e21121189 - 03 Dec 2019
Cited by 2 | Viewed by 936
Abstract
Following on from two previous JETC (Joint European Thermodynamics Conference) presentations, we present a preliminary report of further advances towards the thermodynamic description of critical behavior and a supercritical gas-liquid coexistence with a supercritical fluid mesophase defined by percolation loci. The experimental data [...] Read more.
Following on from two previous JETC (Joint European Thermodynamics Conference) presentations, we present a preliminary report of further advances towards the thermodynamic description of critical behavior and a supercritical gas-liquid coexistence with a supercritical fluid mesophase defined by percolation loci. The experimental data along supercritical constant temperature isotherms (T ≥ Tc) are consistent with the existence of a two-state mesophase, with constant change in pressure with density, rigidity, (dp/dρ) T, and linear thermodynamic state-functions of density. The supercritical mesophase is bounded by 3rd-order phase transitions at percolation thresholds. Here we present the evidence that these percolation transitions of both gaseous and liquid states along any isotherm are preceded by pre-percolation hetero-phase fluctuations that can explain the thermodynamic properties in the mesophase and its vicinity. Hetero-phase fluctuations give rise to one-component colloidal-dispersion states; a single Gibbs phase retaining 2 degrees of freedom in which both gas and liquid states with different densities percolate the phase volume. In order to describe the thermodynamic properties of two-state critical and supercritical coexistence, we introduce the concept of a hypothetical homo-phase of both gas and liquid, defined as extrapolated equilibrium states in the pre-percolation vicinity, with the hetero-phase fractions subtracted. We observe that there can be no difference in chemical potential between homo-phase liquid and gaseous states along the critical isotherm in mid-critical isochoric experiments when the meniscus disappears at T = Tc. For T > Tc, thermodynamic states comprise equal mole fractions of the homo-phase gas and liquid, both percolating the total phase volume, at the same temperature, pressure, and with a uniform chemical potential, stabilised by a positive finite interfacial surface tension. Full article
(This article belongs to the Special Issue Selected Papers from 15th Joint European Thermodynamics Conference)
Show Figures

Figure 1

Open AccessArticle
Entropic Divergence and Entropy Related to Nonlinear Master Equations
Entropy 2019, 21(10), 993; https://doi.org/10.3390/e21100993 - 11 Oct 2019
Cited by 2 | Viewed by 798
Abstract
We reverse engineer entropy formulas from entropic divergence, optimized to given classes of probability distribution function (PDF) evolution dynamical equation. For linear dynamics of the distribution function, the traditional Kullback–Leibler formula follows from using the logarithm function in the Csiszár’s f-divergence construction, while [...] Read more.
We reverse engineer entropy formulas from entropic divergence, optimized to given classes of probability distribution function (PDF) evolution dynamical equation. For linear dynamics of the distribution function, the traditional Kullback–Leibler formula follows from using the logarithm function in the Csiszár’s f-divergence construction, while for nonlinear master equations more general formulas emerge. As applications, we review a local growth and global reset (LGGR) model for citation distributions, income distribution models and hadron number fluctuations in high energy collisions. Full article
(This article belongs to the Special Issue Selected Papers from 15th Joint European Thermodynamics Conference)
Open AccessArticle
Efficiencies and Work Losses for Cycles Interacting with Reservoirs of Apparent Negative Temperatures
Entropy 2019, 21(8), 749; https://doi.org/10.3390/e21080749 - 31 Jul 2019
Viewed by 1046
Abstract
Inverted quantum states of apparent negative temperature store the work required for their creation [Struchtrup. Phys. Rev. Lett. 2018, 120, 250602]. Thermodynamic cycles operating between a classical reservoir and an inverted state reservoir seem to have thermal efficiencies at or even [...] Read more.
Inverted quantum states of apparent negative temperature store the work required for their creation [Struchtrup. Phys. Rev. Lett. 2018, 120, 250602]. Thermodynamic cycles operating between a classical reservoir and an inverted state reservoir seem to have thermal efficiencies at or even above unity. These high efficiencies result from inappropriate definition adopted from classical heat engines. A properly defined efficiency compares the work produced in the cycle to the work expended in creating the reservoir. Due to work loss to irreversible processes, this work storage based efficiency always has values below unity. Full article
(This article belongs to the Special Issue Selected Papers from 15th Joint European Thermodynamics Conference)
Show Figures

Figure 1

Back to TopTop