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In this paper, we provide an account of analytical results related to the Tsallis thermodynamics that have been the subject matter of a lot of studies in the field of high-energy collisions. After reviewing the results for the classical case in the massless limit and for arbitrarily massive classical particles, we compute the quantum thermodynamic variables. For the first time, the analytical formula for the pressure of a Tsallis-like gas of massive bosons has been obtained. The study serves both as a brief review of the knowledge gathered in this area, and as original research that forwards the existing scholarship. The results of the present paper will be important in a plethora of studies in the field of high-energy collisions including the propagation of non-linear waves generated by the traversal of high-energy particles inside the quark-gluon plasma medium showing the features of non-extensivity.

The hypothesis of an increase in free energy (exergy) by ecosystems during evolution is tested on direct measurements. As a measuring system of thermodynamic parameters (exergy, information, entropy), a series of measurements of reflected solar radiation in bands of Landsat multispectral imagery for 20 years is used. The thermodynamic parameters are compared for different types of ecosystems depending on the influx of solar radiation, weather conditions and the composition of communities. It is shown that maximization of free energy occurs only in a succession series (time scale of several hundred years), and on a short evolutionary time scale of several thousand years, various strategies of energy use are successfully implemented at the same time: forests always maximize exergy and, accordingly, transpiration, meadows&mdash, disequilibrium and biological productivity in summer, and swamps, due to a prompt response to changes in temperature and moisture, maintaining disequilibrium and productivity throughout the year. On the basis of the obtained regularities, we conclude that on an evolutionary time scale, the thermodynamic system changes in the direction of increasing biological productivity and saving moisture, which contradicts the hypothesis of maximizing free energy in the course of evolution.

In this thesis we studied the thermodynamic variables pressure, chemical potential and surface tension for active Brownian particles (ABPs). The motivation comes largely from the motility-induced phase separation (MIPS) that purely repulsive particles at high enough density can undergo when they are made sufficiently active. MIPS was introduced in chapter 2. We presented phase diagrams, and explained its onset from a stability analysis of the homogeneous isotropic phase. The phenomenon of MIPS inspired two research questions that are central to this thesis. The first question is: can the coexisting densities be found by equating the pressure and chemical potentials of the two phases? Since ABPs are out of equilibrium, a pressure and chemical potential first need to be defined. Chapters 3, 4 and 5 studied the definition of pressure. While complications arise for particles that are anisotropic (chapter 3), or whose propulsion speed is spatially dependent (chapter 4), the situation is relatively straightforward for isotropic particles with homogeneous propulsion speed: the total pressure of the system is the sum of the ‘bare’ pressure, which has the same functional form as the equilibrium pressure, and the swim pressure, which is induced by the activity. If one takes into account the fact that the ABPs swim in a solvent (chapter 3), then the bare pressure is associated with the colloids, while the swim pressure is identified as the pressure of the solvent. Their sum is then indeed the total pressure of the suspension. For these isotropic particles with homogeneous propulsion speed, chapter 5 studied the definition of a chemical potential, and tested whether, together with the pressure, it could be used to predict the coexisting densities. While the densities could be accurately predicted for a coexistence of weakly active Lennard-Jones particles, this was not the case for the highly active MIPS. The discrepancy is a consequence of the fact that the chemical potential-like quantity is not a state function, and that its bulk value depends on the profiles in the interface. The second question concerns the interface of MIPS. In Ref. [26] it was found that its interfacial tension is negative. What does this precisely mean, and why is the interface nonetheless stable? These questions were studied in chapter 4. This chapter did not directly study the MIPS interface, but a simpler system that we showed to share important qualitative features: the interface formed by an active ideal gas in between two bulks with different propulsion speeds. We proposed two possible definitions of the interfacial tension, and investigated the stability of the interface. Remarkably, just like for MIPS, the normal force on a piece of perturbed interface acts in the same direction as the perturbation, and thus seems to have a destabilizing effect. Nonetheless, we found the interface to be stable. The reason is that the interfacial tension depends on the lateral position in the interface. This leads, by a Marangoni-like effect, to tangential currents that restore the interface to its original state.

In this thesis we studied the thermodynamic variables pressure, chemical potential and surface tension for active Brownian particles (ABPs). The motivation comes largely from the motility-induced phase separation (MIPS) that purely repulsive particles at high enough density can undergo when they are made sufficiently active. MIPS was introduced in chapter 2. We presented phase diagrams, and explained its onset from a stability analysis of the homogeneous isotropic phase. The phenomenon of MIPS inspired two research questions that are central to this thesis. The first question is: can the coexisting densities be found by equating the pressure and chemical potentials of the two phases? Since ABPs are out of equilibrium, a pressure and chemical potential first need to be defined. Chapters 3, 4 and 5 studied the definition of pressure. While complications arise for particles that are anisotropic (chapter 3), or whose propulsion speed is spatially dependent (chapter 4), the situation is relatively straightforward for isotropic particles with homogeneous propulsion speed: the total pressure of the system is the sum of the ‘bare’ pressure, which has the same functional form as the equilibrium pressure, and the swim pressure, which is induced by the activity. If one takes into account the fact that the ABPs swim in a solvent (chapter 3), then the bare pressure is associated with the colloids, while the swim pressure is identified as the pressure of the solvent. Their sum is then indeed the total pressure of the suspension. For these isotropic particles with homogeneous propulsion speed, chapter 5 studied the definition of a chemical potential, and tested whether, together with the pressure, it could be used to predict the coexisting densities. While the densities could be accurately predicted for a coexistence of weakly active Lennard-Jones particles, this was not the case for the highly active MIPS. The discrepancy is a consequence of the fact that the chemical potential-like quantity is not a state function, and that its bulk value depends on the profiles in the interface. The second question concerns the interface of MIPS. In Ref. [26] it was found that its interfacial tension is negative. What does this precisely mean, and why is the interface nonetheless stable? These questions were studied in chapter 4. This chapter did not directly study the MIPS interface, but a simpler system that we showed to share important qualitative features: the interface formed by an active ideal gas in between two bulks with different propulsion speeds. We proposed two possible definitions of the interfacial tension, and investigated the stability of the interface. Remarkably, just like for MIPS, the normal force on a piece of perturbed interface acts in the same direction as the perturbation, and thus seems to have a destabilizing effect. Nonetheless, we found the interface to be stable. The reason is that the interfacial tension depends on the lateral position in the interface. This leads, by a Marangoni-like effect, to tangential currents that restore the interface to its original state.

Interface energy and kinetic coefficient of crystal growth strongly depend on the face of the crystalline lattice. To investigate the kinetic anisotropy and velocity of different crystallographic faces we use the hyperbolic (modified) phase field crystal model which takes into account atomic density (as a slow thermodynamic variable) and atomic flux (as a fast thermodynamic variable). Such model covers slow and rapid regimes of interfaces propagation at small and large driving forces during solidification. In example of BCC crystal lattice invading the homogeneous liquid, dynamical regimes of advancing front propagating along the selected crystallographic directions are studied. The obtained velocity and the velocity sequences for different faces are compared with known results., Comment: Accepted manuscript to Journal of Crystal Growth

The main motivation and novel notion of this present communication is to implement the recently suggested fourth order with four stages embedded RKARMS(4,4) algorithm to examine its efficiency in reinvesting the structures of extrasolar protoplanets formed via disk instability which being presented in Paul et al. [1] (G.C. Paul, M.M. Rahman, D. Kumar, M.C. Barman, the radius spectrum of solid grains settling in gaseous giant protoplanets, Earth Sci. Inform. 6 (2013) 137–144) for the case of convective heat transfer using classical Runge-Kutta (RK) technique of order four. The results by the RKARMS(4,4) algorithm compared well with those obtained by the classical RK method of order four for any time length and found to be more suitable., Applied mathematics; Astrophysics; Computational mathematics; Planetary sciences; Extrasolar protoplanets; Instability; Thermodynamic variables; RKARMS(4,4) algorithm; Truncation errors.

[EN] The filling process in water pipelines produces pressure surges caused by the compression of air pockets. In this sense, air valves should be appropriately designed to expel sufficient air to avoid pipeline failure. Recent studies concerning filling maneuvers have been addressed without considering the behavior of air valves. This work shows a mathematical model developed by the authors which is capable of simulating the main hydraulic and thermodynamic variables during filling operations under the effect of the air valve in a single pipeline, which is based on the mass oscillation equation, the air¿water interface, the polytropic equation of the air phase, the air mass equation, and the air valve characterization. The mathematical model is validated in a 7.3-m-long pipeline with a 63-mm nominal diameter. A commercial air valve is positioned in the highest point of the hydraulic installation. Measurements indicate that the mathematical model can be used to simulate this phenomenon by providing good accuracy., This work is supported by Fundacao para a Ciencia e Tecnologia (FCT), Portugal (grant number PD/BD/114459/2016).

International audience; Poromechanics offers a consistent theoretical framework for describing the mechanical response of porous solids fully or partially saturated with a fluid phase. When dealing with fully saturated microporous materials, which exhibit pores of the nanometer size, effects due to adsorption and confinement of the fluid molecules in the smallest pores must be accounted for. From the mechanical point of view, these phenomena result into volumetric deformations of the porous solid, the so-called "swelling" phenomenon. The present work investigates how the poromechanical theory may be refined in order to describe such adsorption and confinement induced effects in microporous solids. Poromechanics is revisited in the context of isotropic microporous materials with generic pore size distributions. The new formulation introduces an effective pore pressure, defined as a thermodynamic variable at the representative volume element scale (mesoscale), which is related to the overall mechanical work of the confined fluid. Accounting for the thermodynamic equilibrium of the system, we demonstrate that the effective pore pressure depends on macroscopic variables, such as the bulk fluid pressure, the temperature and the total and excess adsorbed quantity of fluid. As an illustrating example, we apply the model to compute strains and variations of porosity in the case of the methane and carbon dioxide sorption on coal. Agreement with experimental data found in the literature is observed.

The morphology and the microscopic internal dynamics of a bidimensional gel formed by spontaneous aggregation of gold nanoparticles confined at the water surface are investigated by a suite of techniques, including grazing-incidence x-ray photon correlation spectroscopy (GI-XPCS). The range of concentrations studied spans across the percolation transition for the formation of the gel. The dynamical features observed by GI-XPCS are interpreted in view of the results of microscopical imaging; an intrinsic link between the mechanical modulus and internal dynamics is demonstrated for all the concentrations. Our work presents, to the best of our knowledge, the first example of a transition from stretched to compressed correlation function actively controlled by quasistatically varying the relevant thermodynamic variable. Moreover, by applying a model proposed time ago by Duri and Cipelletti [A. Duri and L. Cipelletti, Europhys. Lett. 76, 972 (2006)] we are able to build a novel master curve for the shape parameter, whose scaling factor allows us to quantify a 'long time displacement length'. This characteristic length is shown to converge, as the concentration is increased, to the 'short time localization length' determined by pseudo Debye-Waller analysis of the initial contrast. Finally, the intrinsic dynamics of the system are then compared with that induced by means of a delicate mechanical perturbation applied to the interface.

International audience; Poromechanics offers a consistent theoretical framework for describing the mechanical response of porous solids fully or partially saturated with a fluid phase. When dealing with fully saturated nanoporous materials, which exhibit pores of the nanometer size, effects due to adsorption and confinement of the fluid molecules in the smallest pores must be accounted for. From the mechanical point of view, these phenomena result into volumetric deformations of the porous solid, the so-called "swelling" phenomenon. The present work investigates how the poromechanical theory may be refined in order to describe such adsorption and confinement induced effects in nanoporous solids. The new formulation introduces an effective pore pressure, defined as a thermodynamic variable at the representative volume element scale (mesoscale), which is related to the overall mechanical work of the confined fluid. Accounting for the thermodynamic equilibrium of the system, we demonstrate that the effective pore pressure depends on measurable variables, such as the bulk fluid pressure, the temperature and the total and excess adsorbed mass of fluid. As an illustrating example, we compute the strains in the case of the methane and carbon dioxide sorption-induced swelling of an activated carbon. The fits provide a good agreement with material parameters (apparent and matrix compression moduli, porosity) available in the literature, with a close agreement with experimental data.

[EN] This paper presents a novel non-invasive technique to estimate the turbocharger shaft whirl motion. The aim of this article is to present a system for monitoring the shaft motion of a turbocharger, which will be used in turbocharger destructive testing. To achieve this, a camera and a light source were installed in a turbocharger test bench with a controlled lubrication circuit. An image recording methodology and a process algorithm have been developed, in order to estimate the shaft motion. This processing consists on differentiating specific zones of the image, in order to obtain their coordinates. Two reference points have been configured on the compressor side, which help to calculate the relative position of the shaft, avoiding the errors due to structural vibrations. Maximum eccentricity of the turbocharger has been determined and it has been compared with shaft motion when it is spinning in different conditions. A luminosity study has been also done, in order to improve the process and to obtain locus of shaft position in a picture exposition time period. The technique has been applied to diagnosis of a lubrication failure test and the main results will be presented in this article: like shaft motion figures; thermodynamic variables and pictures of the shaft while it is spinning at abnormal lubrication conditions. The measuring components used in this technique have the ability to withstand the catastrophic failure of the turbocharger in this type of test. © 2012 Elsevier Ltd.

A one-pot hemimicellar synthesis of oriented, amphiphilic, and fluorescent Janus gold clusters, establishing the Janus character in terms of ligand asymmetry and distribution, has been demonstrated. The method was based on the efficient Langmuir strategy, where the in situ two-dimensional (2D) reduction of Au3+ in the sprayed micellar electrostatic complex, TO A+-AuCl4 -, was accomplished by subphase tryptophan that acted as the hydrophilic protecting ligand on one hemisphere of the spherical gold cluster. In contrast to the reported micelle-assisted Janus cluster formation, here the cluster growth occurred inside the surface pressure driven hemimicelles, which rapidly formed 2D cluster arrays without any interfacial reorientation. The Janus structure was validated using angle dependent polarized Fourier Transform Infrared Reflection-Absorption Spectroscopy (FT-IRRAS), where orientation dependent vibrational changes in the adsorbed ligand functionalities were detected. Electrochemical impedance measurements of the transferred Janus layers onto hydrophobized ITO revealed the heterogeneous electron transfer rate constant kET to show a clear orientational odd-even parity effect with the odd layers showing much higher rates. Isobaric area relaxation investigations further evidenced toward a hemispherical instantaneous nucleation with edge growthmechanismof the nanoclusters formed at the tryptophan subphase. Surface pressure as a thermodynamic variable effectively controlled the interparticle separation; intercluster electron coupling exhibited insulator-metal transition in the Janus cluster monolayers through scanning electrochemical microscopy investigations. � 2010 American Chemical Society.

The standard picture of planet formation posits that giant gas planets are over-grown rocky planets massive enough to attract enormous gas atmospheres. It has been shown recently that the opposite point of view is physically plausible: the rocky terrestrial planets are former giant planet embryos dried of their gas "to the bone" by the influences of the parent star. Here we provide a brief overview of this "Tidal Downsizing" hypothesis in the context of the Solar System structure.