Determining the thermal properties of materials with complex structures is still a major engineering challenge today. The well-known heat pulse experiment can be used to determine the thermal diffusivity by measuring the temperature history as a thermal response for a fast excitation. However, the evaluation of the measurements can be challenging, especially when dealing with non-homogeneous samples. The thermal behavior of such heterogeneous materials may exhibit a response including two-time scales. Therefore, the Fourier equation is not necessarily applicable. The simplest possible alternatives are the 2-temperature models the Guyer–Krumhansl and Jeffreys heat equations. In the present paper, we focus on the interpretation of the Jeffreys heat equation; studying its analytical solution, we present a fitting method for determining the unknown parameters. We also discuss its relation with the other two heat equations, and we offer an interpretation of how to characterize the transient response of heterogeneous materials.
{"title":"On the dynamic thermal conductivity and diffusivity observed in heat pulse experiments","authors":"Anna Fehér, Róbert Kovács","doi":"10.1515/jnet-2023-0119","DOIUrl":"https://doi.org/10.1515/jnet-2023-0119","url":null,"abstract":"Determining the thermal properties of materials with complex structures is still a major engineering challenge today. The well-known heat pulse experiment can be used to determine the thermal diffusivity by measuring the temperature history as a thermal response for a fast excitation. However, the evaluation of the measurements can be challenging, especially when dealing with non-homogeneous samples. The thermal behavior of such heterogeneous materials may exhibit a response including two-time scales. Therefore, the Fourier equation is not necessarily applicable. The simplest possible alternatives are the 2-temperature models the Guyer–Krumhansl and Jeffreys heat equations. In the present paper, we focus on the interpretation of the Jeffreys heat equation; studying its analytical solution, we present a fitting method for determining the unknown parameters. We also discuss its relation with the other two heat equations, and we offer an interpretation of how to characterize the transient response of heterogeneous materials.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":"42 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140104673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We study the optimal performance of an endoreversible quantum dot heat engine, in which the heat transfer between the system and baths is mediated by qubits, operating under the conditions of a trade-off objective function known as the maximum efficient power function defined by the product of power and efficiency of the engine. First, we numerically study the optimization of the efficient power function for the engine under consideration. Then, we obtain some analytic results by applying a high-temperature limit and compare the performance of the engine at maximum efficient power function to the engine operating in the maximum power regime. We find that the engine operating at maximum efficient power function produces at least 88.89 % of the maximum power output while at the same time reducing the power loss due to entropy production by a considerable amount. We conclude by studying the stochastic simulations of the efficiency of the engine in maximum power and maximum efficient power regime. We find that the engine operating at maximum power is subjected to fewer power fluctuations as compared to the one operating at maximum efficient power function.
{"title":"Optimization analysis of an endoreversible quantum heat engine with efficient power function","authors":"Kirandeep Kaur, Anmol Jain, Love Sahajbir Singh, Rakesh Singla, Shishram Rebari","doi":"10.1515/jnet-2023-0082","DOIUrl":"https://doi.org/10.1515/jnet-2023-0082","url":null,"abstract":"We study the optimal performance of an endoreversible quantum dot heat engine, in which the heat transfer between the system and baths is mediated by qubits, operating under the conditions of a trade-off objective function known as the maximum efficient power function defined by the product of power and efficiency of the engine. First, we numerically study the optimization of the efficient power function for the engine under consideration. Then, we obtain some analytic results by applying a high-temperature limit and compare the performance of the engine at maximum efficient power function to the engine operating in the maximum power regime. We find that the engine operating at maximum efficient power function produces at least 88.89 % of the maximum power output while at the same time reducing the power loss due to entropy production by a considerable amount. We conclude by studying the stochastic simulations of the efficiency of the engine in maximum power and maximum efficient power regime. We find that the engine operating at maximum power is subjected to fewer power fluctuations as compared to the one operating at maximum efficient power function.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":"184 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139739500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study explored the capability of semi-empirical and neural network approaches for correlating and predicting some equilibrium and non-equilibrium thermophysical properties of liquid lubricants. The equilibrium properties, including the densities and several thermodynamic coefficients for 12 liquid lubricants, were correlated and predicted through a perturbed hard-chain equation of state (PHC EoS) by an attractive term of Yukawa tail. The molecular parameters of PHC EoS were obtained by correlating them with 935 data points for the densities and isothermal compressibilities of studied systems in the 278–353 K range and pressure up to 70 MPa with the average absolute relative deviations (AARDs) of 0.36 % and 5.25 %, respectively. Then, that EoS was employed to predict the densities of other literature sources (with an AARD of 0.81 %) along with several thermodynamic coefficients, including isobaric expansivities (with an AARD of 12.92 %), thermal pressure coefficients (with the AARD of 12.93 %), and internal pressure (with the AARD of 13.67 %), for which the reference values were obtained from Tait-type equations and available in literature. Apart from the equilibrium mentioned above properties, the PHC EoS was combined with a rough hard-sphere-chain (RHSC) model to correlate and predict the 548 data points for the viscosities of 7 selected liquefied lubricants in 283–353 K range and pressures up to 100 MPa with the AARD of 11.85 %. The accuracy of the results from the RHSC-based model has also been compared with an empirical PηT equation of Tammann-Tait type and an artificial neural network (ANN), both of which were developed in this work. The ANN of one hidden layer and 13 neurons was trained using the back-propagation algorithm. The results acquired from this approach were very promising and demonstrated the potential of the ANN approach for predicting the viscosity of lubricants, reaching an AARD of 0.81 % for the entire dataset.
本研究探索了半经验和神经网络方法在关联和预测液体润滑剂的一些平衡和非平衡热物理性质方面的能力。通过扰动硬链状态方程（PHC EoS），利用汤川尾的吸引力项对 12 种液体润滑剂的平衡特性（包括密度和若干热力学系数）进行了关联和预测。PHC EoS 的分子参数是通过与所研究体系在 278-353 K 范围内的密度和等温压缩性的 935 个数据点进行关联而获得的，这些数据点的平均绝对相对偏差（AARDs）分别为 0.36 % 和 5.25 %。然后，利用该 EoS 预测了其他文献来源的密度（平均绝对相对偏差为 0.81%）以及几个热力学系数，包括等压膨胀率（平均绝对相对偏差为 12.92%）、热压系数（平均绝对相对偏差为 12.93%）和内压（平均绝对相对偏差为 13.67%），这些系数的参考值均来自泰特方程，并可从文献中获得。除上述平衡特性外，PHC EoS 还与粗糙硬球链（RHSC）模型相结合，对 7 种选定液化润滑剂在 283-353 K 范围内的粘度和高达 100 MPa 的压力的 548 个数据点进行了关联和预测，AARD 为 11.85 %。基于 RHSC 模型的结果的准确性还与 Tammann-Tait 型经验 PηT 方程和人工神经网络（ANN）进行了比较，这两个模型都是在这项工作中开发的。采用反向传播算法训练了由一个隐层和 13 个神经元组成的人工神经网络。这种方法取得的结果非常理想，证明了人工神经网络方法在预测润滑油粘度方面的潜力，整个数据集的 AARD 值达到了 0.81%。
{"title":"Modeling equilibrium and non-equilibrium thermophysical properties of liquid lubricants using semi-empirical approaches and neural network","authors":"Sayed Mostafa Hosseini, Taleb Zarei, Mariano Pierantozzi","doi":"10.1515/jnet-2023-0062","DOIUrl":"https://doi.org/10.1515/jnet-2023-0062","url":null,"abstract":"This study explored the capability of semi-empirical and neural network approaches for correlating and predicting some equilibrium and non-equilibrium thermophysical properties of liquid lubricants. The equilibrium properties, including the densities and several thermodynamic coefficients for 12 liquid lubricants, were correlated and predicted through a perturbed hard-chain equation of state (PHC EoS) by an attractive term of Yukawa tail. The molecular parameters of PHC EoS were obtained by correlating them with 935 data points for the densities and isothermal compressibilities of studied systems in the 278–353 K range and pressure up to 70 MPa with the average absolute relative deviations (AARDs) of 0.36 % and 5.25 %, respectively. Then, that EoS was employed to predict the densities of other literature sources (with an AARD of 0.81 %) along with several thermodynamic coefficients, including isobaric expansivities (with an AARD of 12.92 %), thermal pressure coefficients (with the AARD of 12.93 %), and internal pressure (with the AARD of 13.67 %), for which the reference values were obtained from Tait-type equations and available in literature. Apart from the equilibrium mentioned above properties, the PHC EoS was combined with a rough hard-sphere-chain (RHSC) model to correlate and predict the 548 data points for the viscosities of 7 selected liquefied lubricants in 283–353 K range and pressures up to 100 MPa with the AARD of 11.85 %. The accuracy of the results from the RHSC-based model has also been compared with an empirical <jats:italic>PηT</jats:italic> equation of Tammann-Tait type and an artificial neural network (ANN), both of which were developed in this work. The ANN of one hidden layer and 13 neurons was trained using the back-propagation algorithm. The results acquired from this approach were very promising and demonstrated the potential of the ANN approach for predicting the viscosity of lubricants, reaching an AARD of 0.81 % for the entire dataset.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":"34 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139710707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vito Antonio Cimmelli, David Jou, Antonio Sellitto
Over the last twenty-five years, the search for generalized equations that allow us to better understand the phenomenon of heat conduction has become an active frontier both in transport theory, and in non-equilibrium thermodynamics, due to the growing interest in nanotechnologies, thermal metamaterials and fast devices. Here we review how some mathematical analogies between generalized heat-transport equations and well-known equations in hydrodynamics, electronics and optics have been helpful to infer new forms of heat transfer arising in extended thermodynamics and to inspire the consideration of new phenomena. We also examine in each case the thermodynamic basis of the respective formulation.
{"title":"Hydrodynamic, electronic and optic analogies with heat transport in extended thermodynamics","authors":"Vito Antonio Cimmelli, David Jou, Antonio Sellitto","doi":"10.1515/jnet-2023-0096","DOIUrl":"https://doi.org/10.1515/jnet-2023-0096","url":null,"abstract":"Over the last twenty-five years, the search for generalized equations that allow us to better understand the phenomenon of heat conduction has become an active frontier both in transport theory, and in non-equilibrium thermodynamics, due to the growing interest in nanotechnologies, thermal metamaterials and fast devices. Here we review how some mathematical analogies between generalized heat-transport equations and well-known equations in hydrodynamics, electronics and optics have been helpful to infer new forms of heat transfer arising in extended thermodynamics and to inspire the consideration of new phenomena. We also examine in each case the thermodynamic basis of the respective formulation.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":"35 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139567860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In recent years, great efforts are devoted to reducing the work cost of the bit operation, but it is still unclear whether these efforts are sufficient for resolving the temperature stabilization problem in computation. By combining information thermodynamics and a generalized constitutive model which can describe Fourier heat conduction as well as non-Fourier heat transport with nonlocal effects, we here unveil two types of the thermodynamic costs in the temperature stabilization problem. Each type imposes an upper bound on the amount of bits operated per unit time per unit volume, which will eventually limit the speed of the bit operation. The first type arises from the first and second laws of thermodynamics, which is independent of the boundary condition and can be circumvented in Fourier heat conduction. The other type is traceable to the third law of thermodynamics, which will vary with the boundary condition and is ineluctable in Fourier heat conduction. These thermodynamic costs show that reducing the work cost of the bit operation is insufficient for resolving the temperature stabilization problem in computation unless the work cost vanishes.
{"title":"Thermodynamic costs of temperature stabilization in logically irreversible computation","authors":"Shu-Nan Li, Bing-Yang Cao","doi":"10.1515/jnet-2023-0099","DOIUrl":"https://doi.org/10.1515/jnet-2023-0099","url":null,"abstract":"In recent years, great efforts are devoted to reducing the work cost of the bit operation, but it is still unclear whether these efforts are sufficient for resolving the temperature stabilization problem in computation. By combining information thermodynamics and a generalized constitutive model which can describe Fourier heat conduction as well as non-Fourier heat transport with nonlocal effects, we here unveil two types of the thermodynamic costs in the temperature stabilization problem. Each type imposes an upper bound on the amount of bits operated per unit time per unit volume, which will eventually limit the speed of the bit operation. The first type arises from the first and second laws of thermodynamics, which is independent of the boundary condition and can be circumvented in Fourier heat conduction. The other type is traceable to the third law of thermodynamics, which will vary with the boundary condition and is ineluctable in Fourier heat conduction. These thermodynamic costs show that reducing the work cost of the bit operation is insufficient for resolving the temperature stabilization problem in computation unless the work cost vanishes.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":"34 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139567837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Orazio Muscato, Giovanni Nastasi, Vittorio Romano, Giorgia Vitanza
The main aim of this work is to optimize a Quantum Drift Diffusion model (QDD) (V. Romano, M. Torrisi, and R. Tracinà, “Approximate solutions to the quantum drift-diffusion model of semiconductors,” J. Math. Phys., vol. 48, p. 023501, 2007; A. El Ayyadi and A. Jüngel, “Semiconductor simulations using a coupled quantum drift-diffusion schrödinger-Poisson model,” SIAM J. Appl. Math., vol. 66, no. 2, pp. 554–572, 2005; L. Barletti and C. Cintolesi, “Derivation of isothermal quantum fluid equations with Fermi-Dirac and bose-einstein statistics,” J. Stat. Phys., vol. 148, pp. 353–386, 2012) by comparing it with the Boltzmann-Wigner Transport Equation (BWTE) (O. Muscato, “Wigner ensemble Monte Carlo simulation without splitting error of a GaAs resonant tunneling diode,” J. Comput. Electron., vol. 20, pp. 2062–2069, 2021) solved using a signed Monte Carlo method (M. Nedjalkov, H. Kosina, S. Selberherr, C. Ringhofer, and D. K. Ferry, “Unified particle approach to Wigner-Boltzmann transport in small semiconductor devices,” Phys. Rev. B, vol. 70, pp. 115–319, 2004). A situation of high non equilibrium regime is investigated: electron transport in a Resonant Tunneling Diode (RTD) made of GaAs with two potential barriers in GaAlAs. The range of the suitable voltage bias applied to the RTD is analyzed. We find an acceptable agreement between QDD model and BWTE when the applied bias is low or moderate with a threshold of about 0.225 V over a length of 150 nm; it is found out that the use of a field dependent mobility is crucial for getting a good description of the negative differential conductivity in such a range. At higher bias voltages, we expect that QDD model loses accuracy.
这项工作的主要目的是优化量子漂移扩散模型（QDD）（V. Romano, M. Torrisi, and R. Tracinà, "Approximate solutions to the quantum drift-diffusion model of semiconductors," J. Math. Phys.48, p. 023501, 2007; A. El Ayyadi and A. Jüngel, "Semiconductor simulations using a coupled quantum drift-diffusion schrödinger-Poisson model," SIAM J. Appl.物理》，第 148 卷，第 353-386 页，2012 年）与玻尔兹曼-维格纳输运方程（BWTE）（O. Muscato，"Wigner ensemble Monte Carlo simulation without splitting error of a GaAs resonant tunneling diode," J. Comput.电子学》，第 20 卷，第 2062-2069 页，2021 年）使用签名蒙特卡罗方法求解（M. Nedjalkov、H. Kosina、S. Selberherr、C. Ringhofer 和 D. K. Ferry，《小型半导体器件中维格纳-玻尔兹曼传输的统一粒子方法》，《物理评论 B》，第 70 卷，第 115-319 页，2004 年）。研究了一种高非平衡态情况：由砷化镓（GaAs）制成的共振隧道二极管（RTD）中的电子传输，其中有两个砷化镓势垒。分析了应用于 RTD 的合适电压偏置范围。我们发现，当施加的偏压较低或适中时，QDD 模型与 BWTE 之间的一致性可以接受，阈值约为 0.225 V，长度为 150 nm。在更高的偏置电压下，我们预计 QDD 模型会失去准确性。
{"title":"Optimized quantum drift diffusion model for a resonant tunneling diode","authors":"Orazio Muscato, Giovanni Nastasi, Vittorio Romano, Giorgia Vitanza","doi":"10.1515/jnet-2023-0059","DOIUrl":"https://doi.org/10.1515/jnet-2023-0059","url":null,"abstract":"The main aim of this work is to optimize a Quantum Drift Diffusion model (QDD) (V. Romano, M. Torrisi, and R. Tracinà, “Approximate solutions to the quantum drift-diffusion model of semiconductors,” <jats:italic>J. Math. Phys.</jats:italic>, vol. 48, p. 023501, 2007; A. El Ayyadi and A. Jüngel, “Semiconductor simulations using a coupled quantum drift-diffusion schrödinger-Poisson model,” <jats:italic>SIAM J. Appl. Math.</jats:italic>, vol. 66, no. 2, pp. 554–572, 2005; L. Barletti and C. Cintolesi, “Derivation of isothermal quantum fluid equations with Fermi-Dirac and bose-einstein statistics,” <jats:italic>J. Stat. Phys.</jats:italic>, vol. 148, pp. 353–386, 2012) by comparing it with the Boltzmann-Wigner Transport Equation (BWTE) (O. Muscato, “Wigner ensemble Monte Carlo simulation without splitting error of a GaAs resonant tunneling diode,” <jats:italic>J. Comput. Electron</jats:italic>., vol. 20, pp. 2062–2069, 2021) solved using a signed Monte Carlo method (M. Nedjalkov, H. Kosina, S. Selberherr, C. Ringhofer, and D. K. Ferry, “Unified particle approach to Wigner-Boltzmann transport in small semiconductor devices,” <jats:italic>Phys. Rev. B</jats:italic>, vol. 70, pp. 115–319, 2004). A situation of high non equilibrium regime is investigated: electron transport in a Resonant Tunneling Diode (RTD) made of GaAs with two potential barriers in GaAlAs. The range of the suitable voltage bias applied to the RTD is analyzed. We find an acceptable agreement between QDD model and BWTE when the applied bias is low or moderate with a threshold of about 0.225 V over a length of 150 nm; it is found out that the use of a field dependent mobility is crucial for getting a good description of the negative differential conductivity in such a range. At higher bias voltages, we expect that QDD model loses accuracy.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":"156 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139544113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The modeling and understanding of micro- and nano-scale transport processes have raised increasing attention and extensive investigation during the past decades. In this mini-review, we aim to summarize our recent progress on the non-equilibrium thermodynamics of micro- and nano-scale flow and heat transfer. Special emphasis is put on the entropy generation at the interface, which plays a dominant role at small scale due to the strong non-equilibrium nature of particle-boundary interaction. We also prove the thermodynamic compatibility of both the macroscopic hydrodynamic equation and the non-equilibrium boundary conditions from the perspective of bulk and interfacial entropy generations respectively, as supported by the kinetic theory of microscopic particles. The present review will contribute to a clearer elaboration of thermodynamics at micro/nano-scale and its statistical mechanical demonstration, and thus will promote its further development in the future.
{"title":"Thermodynamics of micro- and nano-scale flow and heat transfer: a mini-review","authors":"Yangyu Guo, Moran Wang","doi":"10.1515/jnet-2023-0060","DOIUrl":"https://doi.org/10.1515/jnet-2023-0060","url":null,"abstract":"The modeling and understanding of micro- and nano-scale transport processes have raised increasing attention and extensive investigation during the past decades. In this mini-review, we aim to summarize our recent progress on the non-equilibrium thermodynamics of micro- and nano-scale flow and heat transfer. Special emphasis is put on the entropy generation at the interface, which plays a dominant role at small scale due to the strong non-equilibrium nature of particle-boundary interaction. We also prove the thermodynamic compatibility of both the macroscopic hydrodynamic equation and the non-equilibrium boundary conditions from the perspective of bulk and interfacial entropy generations respectively, as supported by the kinetic theory of microscopic particles. The present review will contribute to a clearer elaboration of thermodynamics at micro/nano-scale and its statistical mechanical demonstration, and thus will promote its further development in the future.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":"52 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139522556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The development of non-Fourier heat conduction models is encouraged by the invalidity of Fourier’s law to explain heat conduction in ultrafast or ultrasmall systems. The production of negative entropy will result from the combination of traditional nonequlibrium thermodynamics and non-Fourier heat conduction models. To resolve this paradox, extended irreversible thermodynamics (EIT) introduces a new state variable. However, real dynamics variables like force and momentum are still missing from nonequilibrium thermodynamics and EIT’s generalized force and generalized flux. Heat has both mass and energy, according to thermomass theory and Einstein’s mass-energy relation. The generalized heat conduction model containing non-Fourier effects was established by thermomass gas model. The thermomass theory reshapes the concept of the generalized force and flux, temperature, and entropy production in nonequilibrium thermodynamics and revisits the assumption for the linear regression of the fluctuations in Onsager reciprocal relation. The generalized heat conduction model based on thermomass theory has been used to study thermal conductivity, thermoelectric effect, and thermal rectification effect in nanosystems.
由于傅里叶定律无法解释超快或超小系统中的热传导，因此非傅里叶热传导模型的发展受到了鼓励。传统的非平衡热力学和非傅里叶热传导模型的结合将产生负熵。为了解决这一矛盾，扩展不可逆热力学（EIT）引入了一个新的状态变量。然而，非平衡热力学和 EIT 的广义力和广义通量中仍然缺少力和动量等实际动力学变量。根据热质理论和爱因斯坦的质能关系，热具有质量和能量。热质气体模型建立了包含非傅里叶效应的广义热传导模型。热质理论重塑了非平衡热力学中广义力和通量、温度和熵产生的概念，并重新审视了昂萨格倒易关系中波动线性回归的假设。基于热质理论的广义热传导模型已被用于研究纳米系统中的热导率、热电效应和热整流效应。
{"title":"Revisit nonequilibrium thermodynamics based on thermomass theory and its applications in nanosystems","authors":"Renjie Hua, Yuan Dong","doi":"10.1515/jnet-2023-0094","DOIUrl":"https://doi.org/10.1515/jnet-2023-0094","url":null,"abstract":"The development of non-Fourier heat conduction models is encouraged by the invalidity of Fourier’s law to explain heat conduction in ultrafast or ultrasmall systems. The production of negative entropy will result from the combination of traditional nonequlibrium thermodynamics and non-Fourier heat conduction models. To resolve this paradox, extended irreversible thermodynamics (EIT) introduces a new state variable. However, real dynamics variables like force and momentum are still missing from nonequilibrium thermodynamics and EIT’s generalized force and generalized flux. Heat has both mass and energy, according to thermomass theory and Einstein’s mass-energy relation. The generalized heat conduction model containing non-Fourier effects was established by thermomass gas model. The thermomass theory reshapes the concept of the generalized force and flux, temperature, and entropy production in nonequilibrium thermodynamics and revisits the assumption for the linear regression of the fluctuations in Onsager reciprocal relation. The generalized heat conduction model based on thermomass theory has been used to study thermal conductivity, thermoelectric effect, and thermal rectification effect in nanosystems.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":"28 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139522568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Energetic laser-accelerated ions can heat a small solid-density sample homogeneously to temperatures over 10,000 K in less than a nanosecond. During this brief heating time, the electron temperature of the sample rises first, and then the ion temperature increases owing to the heat transfer between the hot electrons and cold ions. Since energy deposition from the incident heavy ion beam continues concurrently with the electron-ion relaxation process within the heated sample, the electron and ion temperatures do not reach equilibrium until the end of the heating. Here we calculate the temperature evolutions of electrons and ions within a dense aluminum sample heated by a laser-accelerated gold ions using the two-temperature model. For these calculations, we use the published stopping power data, known electron-ion coupling factors, and the SESAME equation-of-state (EOS) table for aluminum. For the first time, we investigate the electron and ion temperature distributions within the warm dense aluminum sample and the heating uniformity throughout the entire heating period. We anticipate that knowledge of the temperature evolution during heating will allow for the study of the stopping power, thermal conductivity, EOS, and opacity of warm dense matter heated by an energetic heavy ion beam.
高能激光加速离子可在不到一纳秒的时间内将固体密度较小的样品均匀加热到 10,000 K 以上的温度。在这一短暂的加热时间内，样品的电子温度首先升高，然后由于热电子和冷离子之间的热传递，离子温度也随之升高。由于入射重离子束的能量沉积与加热样品内的电子-离子弛豫过程同时进行，电子和离子温度直到加热结束时才达到平衡。在这里，我们使用双温模型计算了在激光加速金离子加热的致密铝样品中电子和离子的温度变化。在计算过程中，我们使用了已公布的停止功率数据、已知的电子-离子耦合因子以及铝的 SESAME 状态方程（EOS）表。我们首次研究了暖致密铝样品内的电子和离子温度分布以及整个加热期间的加热均匀性。我们预计，了解加热过程中的温度演变将有助于研究被高能重离子束加热的暖致密物质的停止功率、热导率、EOS 和不透明度。
{"title":"Heat transfer within nonequilibrium dense aluminum heated by a heavy ion beam","authors":"Chiwan Song, Seongmin Lee, Woosuk Bang","doi":"10.1515/jnet-2023-0061","DOIUrl":"https://doi.org/10.1515/jnet-2023-0061","url":null,"abstract":"Energetic laser-accelerated ions can heat a small solid-density sample homogeneously to temperatures over 10,000 K in less than a nanosecond. During this brief heating time, the electron temperature of the sample rises first, and then the ion temperature increases owing to the heat transfer between the hot electrons and cold ions. Since energy deposition from the incident heavy ion beam continues concurrently with the electron-ion relaxation process within the heated sample, the electron and ion temperatures do not reach equilibrium until the end of the heating. Here we calculate the temperature evolutions of electrons and ions within a dense aluminum sample heated by a laser-accelerated gold ions using the two-temperature model. For these calculations, we use the published stopping power data, known electron-ion coupling factors, and the SESAME equation-of-state (EOS) table for aluminum. For the first time, we investigate the electron and ion temperature distributions within the warm dense aluminum sample and the heating uniformity throughout the entire heating period. We anticipate that knowledge of the temperature evolution during heating will allow for the study of the stopping power, thermal conductivity, EOS, and opacity of warm dense matter heated by an energetic heavy ion beam.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":"105 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139522654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The thermal and electrical properties of photovoltaic cell (PVC) under linear phenomenological heat transfer law between it and the environment is studied through finite time thermodynamics and the volt-ampere characteristic equation. The properties of PVC are affected by heat transfer between PVC and environment. There are optimal solar radiation intensity and PVC output voltage (OV), which make the photoelectric conversion efficiency (PECE) of PVC reach the highest value. When OV and solar radiation intensity are 28.50 V and 700 W/m2, the maximum PECE is 0.156. There is also the best solar radiation intensity, which makes the open-circuit voltage (OCV) reach the maximum. When solar radiant intensity is 669 W/m2, the maximum OCV is 33.14 V. The values of power output and short-circuit current (SCC) are monotonically increasing with solar radiation intensity. Given solar radiation intensity, the power output and OV exhibit a parabolic shape. The operating temperature falls first and then grows with the OV. However, the change of operating temperature with OV is not much. Band gap is a decreasing function of operating temperature. This article can give theoretical support for the design and use of PVCs.
通过有限时间热力学和伏安特性方程，研究了光伏电池（PVC）与环境之间线性现象传热规律下的热特性和电特性。聚氯乙烯的特性受聚氯乙烯与环境之间热传递的影响。存在最佳太阳辐射强度和聚氯乙烯输出电压（OV），使聚氯乙烯的光电转换效率（PECE）达到最高值。当 OV 和太阳辐射强度分别为 28.50 V 和 700 W/m2 时，PECE 最大，为 0.156。还有一个最佳的太阳辐射强度，它使开路电压（OCV）达到最大值。当太阳辐射强度为 669 W/m2 时，最大开路电压为 33.14 V。功率输出和短路电流（SCC）值随太阳辐射强度单调递增。在太阳辐射强度一定的情况下，功率输出和 OCV 呈现抛物线形状。工作温度先下降，然后随 OV 增长。不过，工作温度随 OV 的变化不大。带隙是工作温度的递减函数。本文可为聚氯乙烯的设计和使用提供理论支持。
{"title":"Thermal and electrical properties of photovoltaic cell with linear phenomenological heat transfer law","authors":"Jun Li, Lingen Chen","doi":"10.1515/jnet-2023-0056","DOIUrl":"https://doi.org/10.1515/jnet-2023-0056","url":null,"abstract":"The thermal and electrical properties of photovoltaic cell (PVC) under linear phenomenological heat transfer law between it and the environment is studied through finite time thermodynamics and the volt-ampere characteristic equation. The properties of PVC are affected by heat transfer between PVC and environment. There are optimal solar radiation intensity and PVC output voltage (OV), which make the photoelectric conversion efficiency (PECE) of PVC reach the highest value. When OV and solar radiation intensity are 28.50 V and 700 W/m<jats:sup>2</jats:sup>, the maximum PECE is 0.156. There is also the best solar radiation intensity, which makes the open-circuit voltage (OCV) reach the maximum. When solar radiant intensity is 669 W/m<jats:sup>2</jats:sup>, the maximum OCV is 33.14 V. The values of power output and short-circuit current (SCC) are monotonically increasing with solar radiation intensity. Given solar radiation intensity, the power output and OV exhibit a parabolic shape. The operating temperature falls first and then grows with the OV. However, the change of operating temperature with OV is not much. Band gap is a decreasing function of operating temperature. This article can give theoretical support for the design and use of PVCs.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":"3 1","pages":""},"PeriodicalIF":6.6,"publicationDate":"2024-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139110209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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