The Experts below are selected from a list of 132258 Experts worldwide ranked by ideXlab platform
Yuxiao Liu - One of the best experts on this subject based on the ideXlab platform.
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insight into the microscopic structure of an ads black hole from a Thermodynamical phase transition
Physical Review Letters, 2015Co-Authors: Shaowen Wei, Yuxiao LiuAbstract:Comparing with an ordinary Thermodynamic System, we investigate the possible microscopic structure of a charged anti-de Sitter black hole completely from the Thermodynamic viewpoint. The number density of the black hole molecules is introduced to measure the microscopic degrees of freedom of the black hole. We found that the number density suffers a sudden change accompanied by a latent heat when the black hole System crosses the small-large black hole coexistence curve, while when the System passes the critical point, it encounters a second-order phase transition with a vanishing latent heat due to the continuous change of the number density. Moreover, the Thermodynamic scalar curvature suggests that there is a weak attractive interaction between two black hole molecules. These phenomena might cast new insight into the underlying microscopic structure of a charged anti-de Sitter black hole.
Giazotto Francesco - One of the best experts on this subject based on the ideXlab platform.
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Thermodynamics of a phase-driven proximity Josephson junction
'MDPI AG', 2019Co-Authors: Vischi Francesco, Carrega Matteo, Aggio Alessandro, Virtane Pauli, Giazotto FrancescoAbstract:We study the Thermodynamic properties of a superconductor/normal metal/superconductor Josephson junction {in the short limit}. Owing to the proximity effect, such a junction constitutes a Thermodynamic System where {phase difference}, supercurrent, temperature and entropy are Thermodynamical variables connected by equations of state. These allow conceiving quasi-static processes that we characterize in terms of heat and work exchanged. Finally, we combine such processes to construct a Josephson-based Otto and Stirling cycles. We study the related performance in both engine and refrigerator operating mode.Comment: 32 pages, 16 figure
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Thermodynamics of a Phase-Driven Proximity Josephson Junction
'MDPI AG', 2019Co-Authors: Vischi Francesco, Carrega Matteo, Aggio Alessandro, Virtane Pauli, Giazotto FrancescoAbstract:We study the Thermodynamic properties of a superconductor/normal metal/superconductor Josephson junction in the short limit. Owing to the proximity effect, such a junction constitutes a Thermodynamic System where phase difference, supercurrent, temperature and entropy are Thermodynamical variables connected by equations of state. These allow conceiving quasi-static processes that we characterize in terms of heat and work exchanged. Finally, we combine such processes to construct a Josephson-based Otto and Stirling cycles. We study the related performance in both engine and refrigerator operating mode.peerReviewe
Shaowen Wei - One of the best experts on this subject based on the ideXlab platform.
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insight into the microscopic structure of an ads black hole from a Thermodynamical phase transition
Physical Review Letters, 2015Co-Authors: Shaowen Wei, Yuxiao LiuAbstract:Comparing with an ordinary Thermodynamic System, we investigate the possible microscopic structure of a charged anti-de Sitter black hole completely from the Thermodynamic viewpoint. The number density of the black hole molecules is introduced to measure the microscopic degrees of freedom of the black hole. We found that the number density suffers a sudden change accompanied by a latent heat when the black hole System crosses the small-large black hole coexistence curve, while when the System passes the critical point, it encounters a second-order phase transition with a vanishing latent heat due to the continuous change of the number density. Moreover, the Thermodynamic scalar curvature suggests that there is a weak attractive interaction between two black hole molecules. These phenomena might cast new insight into the underlying microscopic structure of a charged anti-de Sitter black hole.
Hal Tasaki - One of the best experts on this subject based on the ideXlab platform.
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universal trade off relation between power and efficiency for heat engines
Physical Review Letters, 2016Co-Authors: Naoto Shiraishi, Keiji Saito, Hal TasakiAbstract:For a general Thermodynamic System described as a Markov process, we prove a general lower bound for dissipation in terms of the square of the heat current, thus establishing that nonvanishing current inevitably implies dissipation. This leads to a universal trade-off relation between efficiency and power, with which we rigorously prove that a heat engine with nonvanishing power never attains the Carnot efficiency. Our theory applies to Systems arbitrarily far from equilibrium, and does not assume any specific symmetry of the model.
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quantum statistical mechanical derivation of the second law of Thermodynamics a hybrid setting approach
Physical Review Letters, 2016Co-Authors: Hal TasakiAbstract:: Based on quantum statistical mechanics and microscopic quantum dynamics, we prove Planck's and Kelvin's principles for macroscopic Systems in a general and realistic setting. We consider a hybrid quantum System that consists of the Thermodynamic System, which is initially in thermal equilibrium, and the "apparatus" which operates on the former, and assume that the whole System evolves autonomously. This provides a satisfactory derivation of the second law for macroscopic Systems.
Vijaysekhar Chellaboina - One of the best experts on this subject based on the ideXlab platform.
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Thermodynamic modeling energy equipartition and nonconservation of entropy for discrete time dynamical Systems
Advances in Difference Equations, 2005Co-Authors: Wassim M. Haddad, Sergey G. Nersesov, Qing Hui, Vijaysekhar ChellaboinaAbstract:We develop Thermodynamic models for discrete-time large-scale dynamical Systems. Specifically, using compartmental dynamical System theory, we develop energy flow models possessing energy conservation, energy equipartition, temperature equipartition, and entropy nonconservation principles for discrete-time, large-scale dynamical Systems. Furthermore, we introduce a new and dual notion to entropy; namely, ectropy, as a measure of the tendency of a dynamical System to do useful work and grow more organized, and show that conservation of energy in an isolated Thermodynamic System necessarily leads to nonconservation of ectropy and entropy. In addition, using the System ectropy as a Lyapunov function candidate, we show that our discrete-time, large-scale Thermodynamic energy flow model has convergent trajectories to Lyapunov stable equilibria determined by the System initial subSystem energies.
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Thermodynamic modeling energy equipartition and nonconservation of entropy for discrete time dynamical Systems
American Control Conference, 2005Co-Authors: Wassim M. Haddad, Sergey G. Nersesov, Qing Hui, Vijaysekhar ChellaboinaAbstract:In this paper we develop Thermodynamic models for discrete-time large-scale dynamical Systems. Specifically, using compartmental dynamical System theory, we develop energy flow models possessing energy conservation, energy equipartition, temperature equipartition, and entropy nonconservation principles for discrete-time, large-scale dynamical Systems. Furthermore, we introduce a new and dual notion to entropy, namely, ectropy, as a measure of the tendency of a dynamical System to do useful work and grow more organized, and show that conservation of energy in an isolated Thermodynamic System necessarily leads to nonconservation of ectropy and entropy. In addition, using the System ectropy as a Lyapunov function candidate we show that our discrete-time, large-scale Thermodynamic energy flow model has convergent trajectories to Lyapunov stable equilibria determined by the System initial subSystem energies.
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a System theoretic foundation for Thermodynamics energy flow energy balance energy equipartition entropy and ectropy
American Control Conference, 2004Co-Authors: Wassim M. Haddad, Vijaysekhar Chellaboina, Sergey G. NersesovAbstract:We develop a System-theoretic foundation for Thermodynamics using a large-scale dynamical Systems perspective. Specifically, using compartmental dynamical System energy flow models, we place the universal energy conservation, energy equipartition, temperature equipartition, and entropy nonconservation laws of Thermodynamics on a System-theoretic foundation. Furthermore, we introduce a new and dual notion to entropy; namely, ectropy, as a measure of the tendency of a dynamical System to do useful work and show that conservation of energy in an isolated Thermodynamic System necessarily leads to nonconservation of ectropy and entropy. In addition, using the System ectropy as a Lyapunov function candidate we show that our large-scale Thermodynamic energy flow model has convergent trajectories to Lyapunov stable equilibria determined by the large-scale System initial subSystem energies.
