thermodynamic quantity
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Author(s):  
Umberto Lucia ◽  
Debora Fino ◽  
Giulia Grisolia

AbstractThe United Nations action plan Agenda 21 has represented a milestone toward Sustainable Development. On its 40th Chapter, it is introduced the requirement to dispose of an accurate and continuous collection of information, essential for decision-making. Besides bridging the data gap and improving the information availability, it is highlighted the need to dispose of sustainable development indicators, in order to assess and monitor the performances of countries toward sustainability. In this paper, we develop an improvement of a new indicator, recently introduced linking environmental anthropic footprint and social and industrial targets. Here, we suggest a link with the Income Index, in order to consider also a condition of people well-being. Our results consists in an improvement of the present approaches to sustainability; indeed, we link the socio-economic considerations, quantified by the Income Index and the Human Development Index, to the engineering approach to optimization, introducing the thermodynamic quantity entropy generation, related to irreversibility. In this way, two different new indicators are introduced, the Thermodynamic Income Index and the Thermodynamic Human Development Index, which quantitatively express a new viewpoint, which goes beyond the dichotomy between socio-economic considerations on one hand and engineering and scientific approach to sustainability on the other one. So, the result leads to a unified tool useful for the designing of new policies and interventions for a sustainable development for the next generations.



Entropy ◽  
2021 ◽  
Vol 23 (5) ◽  
pp. 573
Author(s):  
Alexey V. Melkikh

Quantum entanglement can cause the efficiency of a heat engine to be greater than the efficiency of the Carnot cycle. However, this does not mean a violation of the second law of thermodynamics, since there is no local equilibrium for pure quantum states, and, in the absence of local equilibrium, thermodynamics cannot be formulated correctly. Von Neumann entropy is not a thermodynamic quantity, although it can characterize the ordering of a system. In the case of the entanglement of the particles of the system with the environment, the concept of an isolated system should be refined. In any case, quantum correlations cannot lead to a violation of the second law of thermodynamics in any of its formulations. This article is devoted to a technical discussion of the expected results on the role of quantum entanglement in thermodynamics.



2020 ◽  
Author(s):  
Michael Mercer ◽  
Chao Peng ◽  
Cindy Soares ◽  
Harry Hoster ◽  
Denis Kramer

Abstract Cell voltage is a fundamental quantity used to monitor and control Li-ion batteries. The open circuit voltage (OCV) is of particular interest as it is believed to be a thermodynamic quantity, free of kinetic effects and history and, therefore, "simple" to interpret. Here we show that the OCV characteristics of graphite show hysteresis between charge and discharge that does not solely originate from Li dynamics and that the OCV is in fact history dependent. Combining First Principles calculations with temperature-controlled electrochemical measurements, we identify a residual hysteresis that persists even at elevated temperatures of greater than 50°C due to differences in the phase succession between charge and discharge. Experimental entropy profiling, as well as energies and volume changes determined from First Principles calculations, suggest that the residual hysteresis is associated with different host lattice stackings of carbon and is related to Li disorder across planes in stage II configurations.



Author(s):  
S. S. Kurovets ◽  
E. O. Chornyi

The prediction of the phase state of hydrocarbons at great depths in the area of high temperatures and pressures is of particular relevance today. The peculiarity of the current forecasts is that the pressure-and-temperature conditions of the occurrence and the physical parameters of the reservoir oils are considered as combined average values in a single, integral Inner Zone of the Pre-Carpathian Depression. The specificity of changing each of them is also the same and is forced to extend to the entire territory of the zone. The article considers an important issue of substantiation of a new, more detailed forecast. It is necessary to be able to pre-dict the basic characteristics and phase state of reservoir oils depending on the depth of occurrence in different parts of the Inner Zone. The article considers the possibility of determining the physical parameters of formation hydrocarbon fluids by grapho-analytical method only when there are results of the research of wells at steady and unstable regimes. The developed method allows to quickly determine the set of physical parameters of reservoir oils: saturation pressure, overpressure value, gas content, average gas solubility coefficient, reservoir density, volume factor and oil shrinkage, conversion shrinkage factor, compressibility and thermal expansion factor, the distribution of fluid mass into liquid and gas phases under standard surface conditions and under the condition of fluid evaporation. The calculated equations are based on the use of universal thermodynamic quantity – the molecular weight of the hydrocarbon system. Being the function of only this component composition of the system, the molecular weight does not depend on pressure and temperature. This method allows to estimate the opera-tional stocks of fluids immediately after receiving industrial inflows in the first well, i.e. before the complex of laboratory studies.



2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Yaakov Kleeorin ◽  
Holger Thierschmann ◽  
Hartmut Buhmann ◽  
Antoine Georges ◽  
Laurens W. Molenkamp ◽  
...  

AbstractEntropy is a fundamental thermodynamic quantity indicative of the accessible degrees of freedom in a system. While it has been suggested that the entropy of a mesoscopic system can yield nontrivial information on emergence of exotic states, its measurement in such small electron-number system is a daunting task. Here we propose a method to extract the entropy of a Coulomb-blockaded mesoscopic system from transport measurements. We prove analytically and demonstrate numerically the applicability of the method to such a mesoscopic system of arbitrary spectrum and degeneracies. We then apply our procedure to measurements of thermoelectric response of a single quantum dot, and demonstrate how it can be used to deduce the entropy change across Coulomb-blockade valleys, resolving, along the way, a long-standing puzzle of the experimentally observed finite thermoelectric response at the apparent particle-hole symmetric point.



Materia Japan ◽  
2019 ◽  
Vol 58 (11) ◽  
pp. 641-644
Author(s):  
Nobuyuki Takahira


Author(s):  
Ikechukwu Iloh Udema ◽  
Abraham Olalere Onigbinde

Background: There seems to be a mathematical or a conceptual error in an equation whose substitution into other equations for the determination of an apparent hydrated molar volume (V1) of a cosolute leads to an incorrect answer. Objectives: The objectives are 1) To show theoretically that the preferential interaction parameter (PIP) is an extensive thermodynamic quantity, 2) rederive new equations and reexamine various equations related to solution structure, 3) apply derived equation for the determination of V1, and 4) determine m-values and cognate preferential interaction parameter (PIP). Methods: The research is mainly theoretical and partly experimental. Bernfeld method of enzyme assay was adopted for the generation of data. Results and Discussion: The investigation showed that equation linking chemical potential of osmolyte to solution structure is dimensionally invalid; PIP was seen as a thermodynamically extensive quantity. Equations for the graphical determination of V1 of the osmolyte were derived. With ethanol alone, there were  - m-value and + PIP; with aspirin alone, there were  + m-value and - PIP. There was a change in sign in m-value with sucrose and ethanol/aspirin mixture, and a change in sign in PIP when the latter is taken as function of [ethanol]/[aspirin] and [sucrose](c3). Conclusion: A solution structure is as usual determined by either a relative excess or a deficit of the solution component either in the bulk or around the macromolecular surface domain; the PIP remains thermodynamically an extensive quantity. To be valid there is a need to introduce a reference standard molar concentration or activity to some equations in literature. The slope   from one of the equations seems to give a valid value for V1 (V1 is «1;  is activity coefficient). A known destabiliser may behave as a stabiliser being excluded. Like ethanol, aspirin as cosolute is destabilising and opposed by sucrose.



2019 ◽  
Vol 100 (5) ◽  
pp. 873-895 ◽  
Author(s):  
Carl M. Thomas ◽  
David M. Schultz

AbstractFronts can be computed from gridded datasets such as numerical model output and reanalyses, resulting in automated surface frontal charts and climatologies. Defining automated fronts requires quantities (e.g., potential temperature, equivalent potential temperature, wind shifts) and kinematic functions (e.g., gradient, thermal front parameter, and frontogenesis). Which are the most appropriate to use in different applications remains an open question. This question is investigated using two quantities (potential temperature and equivalent potential temperature) and three functions (magnitude of the horizontal gradient, thermal front parameter, and frontogenesis) from both the context of real-time surface analysis and climatologies from 38 years of reanalyses. The strengths of potential temperature to identify fronts are that it represents the thermal gradients and its direct association with the kinematics and dynamics of fronts. Although climatologies using potential temperature show features associated with extratropical cyclones in the storm tracks, climatologies using equivalent potential temperature include moisture gradients within air masses, most notably at low latitudes that are unrelated to the traditional definition of a front, but may be representative of a broader definition of an airmass boundary. These results help to explain previously published frontal climatologies featuring maxima of fronts in the subtropics and tropics. The best function depends upon the purpose of the analysis, but Petterssen frontogenesis is attractive, both for real-time analysis and long-term climatologies, in part because of its link to the kinematics and dynamics of fronts. Finally, this study challenges the conventional definition of a front as an airmass boundary and suggests that a new, dynamically based definition would be useful for some applications.



2019 ◽  
Vol 28 (07) ◽  
pp. 1950091 ◽  
Author(s):  
Clifford V. Johnson

We present a new type of generalization of the Rényi entropy that follows naturally from its representation as a thermodynamic quantity. We apply it to the case of [Formula: see text]-dimensional conformal field theories (CFTs) reduced on a region bounded by a sphere. It is known how to compute their Rényi entropy as an integral of the thermal entropy of hyperbolic black holes in [Formula: see text]-dimensional anti-de Sitter spacetime. We show how this integral fits into the framework of extended gravitational thermodynamics, and then point out the natural generalization of the Rényi entropy that suggests itself in that light. In the field theory terms, the new generalization employs aspects of the physics of Renormalization Group (RG) flow to define a refined version of the reduced vacuum density matrix. For [Formula: see text], it can be derived directly in terms of twist operators in field theory. The framework presented here may have applications beyond this context, perhaps in studies of both quantum and classical information theoretic properties of a variety of systems.



Particles ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 150-165
Author(s):  
Yuri G. Rudoy ◽  
Yuri P. Rybakov

The problem of pressure fluctuations in the thermal equilibrium state of some objects is discussed, its solution being suggested via generalizing the Bogoliubov–Zubarev theorem. This theorem relates the thermodynamic pressure with the Hamilton function and its derivatives describing the object in question. It is shown that unlike to other thermodynamic quantities (e.g., the energy or the volume) the pressure fluctuations are described not only by a purely thermodynamic quantity (namely, the corresponding thermodynamic susceptibility) but also by some non-thermodynamic quantities. The attempt is made to apply these results to the relativistic ideal gases, with some numerical results being valid for the limiting ultra-relativistic or high-temperature case.



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