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We have developed a thermodynamic theory in the non-equilibrium regime, which we describe as a thermodynamic system–bath model [Koyanagi and Tanimura, J. Chem. Phys. 160, 234112 (2024)]. Based on the dimensionless (DL) minimum work principle, non-equilibrium thermodynamic potentials are expressed in terms of non-equilibrium extensive and intensive variables in time derivative form. This is made possible by incorporating the entropy production rate into the definition of non-equilibrium thermodynamic potentials. These potentials can be evaluated from the DL non-equilibrium-to-equilibrium minimum work principle, which is derived from the principle of DL minimum work and is equivalent to the second law of thermodynamics. We thus obtain the non-equilibrium Massieu–Planck potentials as entropic potentials and the non-equilibrium Helmholtz–Gibbs potentials as free energies. Unlike the fluctuation theorem and stochastic thermodynamics theory, this theory does not require the assumption of a factorized initial condition and is valid in the full quantum regime, where the system and bath are quantum mechanically entangled. Our results are numerically verified by simulating a thermostatic Stirling engine consisting of two isothermal processes and two thermostatic processes using the quantum hierarchical Fokker–Planck equations and the classical Kramers equation derived from the thermodynamic system–bath model. We then show that, from weak to strong system–bath interactions, the thermodynamic process can be analyzed using a non-equilibrium work diagram analogous to the equilibrium one for given time-dependent intensive variables. The results can be used to develop efficient heat machines in non-equilibrium regimes. [ABSTRACT FROM AUTHOR]

Scaffolded molecular networks are important building blocks in biological pigment–protein complexes, and DNA nanotechnology allows analogous systems to be designed and synthesized. System–environment interactions in these systems are responsible for important processes, such as the dissipation of heat and quantum information. This study investigates the role of nanoscale molecular parameters in tuning these vibronic system–environment dynamics. Here, genetic algorithm methods are used to obtain nanoscale parameters for a DNA-scaffolded chromophore network based on comparisons between its calculated and measured optical spectra. These parameters include the positions, orientations, and energy level characteristics within the network. This information is then used to compute the dynamics, including the vibronic population dynamics and system–environment heat currents, using the hierarchical equations of motion. The dissipation of quantum information is identified by the system's transient change in entropy, which is proportional to the heat currents according to the second law of thermodynamics. These results indicate that the dissipation of quantum information is highly dependent on the particular nanoscale characteristics of the molecular network, which is a necessary first step before gleaning the systematic optimization rules. Subsequently, the I-concurrence dynamics are calculated to understand the evolution of the vibronic system's quantum entanglement, which are found to be long-lived compared to these system–bath dissipation processes. [ABSTRACT FROM AUTHOR]

Recognizing that conventional understanding of animal and human locomotion is based on a dated and reductionist machine modeling of organisms, we set out to create a theory of locomotion by reasoning from first principles. We center on the constraints necessitated by 1) the 2nd law of thermodynamics, 2) the theory of evolution, 3) a systems science view of organisms, and 4) the laws of motion, but we also look for compatibility these constraints might find in emerging areas of scientific inquiry (ecological psychology, processual biology, soft matter, biotensegrity), and in the wisdom embedded in various movement traditions and ancient philosophy. Applying and synthesizing these, we propose an updated “bouncing bones” (BB) model for walking and running, which corresponds with maximum efficiency and conservation of energy. [ABSTRACT FROM AUTHOR]

Motivated by the notion that the mathematics of gravity can be reproduced from a statistical requirement of maximal entropy, the consequences of introducing an entropic source term in the Einstein–Hilbert action are studied. For a spatially homogeneous cosmological system driven by this entropic source and enveloped by a time‐evolving apparent horizon, a modified version of the second law of thermodynamics is formulated. An explicit differential equation governing the internal entropy profile is found. Using a Hessian matrix analysis of the internal entropy, the author checked the thermodynamic stability for three categorically different toy models describing (i) a ΛCDM$\Lambda{\rm CDM}$ cosmology, (ii) a unified cosmic expanson, and (iii) a non‐singular ekpyrotic bounce. The mathematical condition for a second order phase transition during these evolutions from the divergence of specific heat at constant volume is found. The new‐found condition is purely kinematic and quadratic in nature, relating the deceleration parameter and the jerk parameter that chalks out an interesting curve on the parameter space. This condition is valid even without the entropic source term and may be treated as a general property of any phase transition. [ABSTRACT FROM AUTHOR]

In this study, the performance of a micro-combustor with an exhaust gas recirculation (EGR) channel was analyzed based on the second law of thermodynamics. Effects of the inlet velocity (V in), equivalence ratio (ϕ), separating wall length (L 1) and nozzle diameter (d in) on entropy generation and exergy efficiency of the micro-combustor were investigated. In general, chemical reaction contributes most to the total exergy destruction (>60%), followed by heat conduction, mass diffusion, and viscous dissipation. Meanwhile, all parts of the entropy generation rate increase with the increase of V in and ϕ. However, the entropy generation rates caused by chemical reaction and heat conduction decrease with the increase of L 1. The entropy generation rates due to chemical reaction and heat conduction show opposite variation trends respect to d in. An increase of V in and ϕ results in higher exergy destruction and exergy loss of the micro-combustor, the largest exergy destruction and exergy loss are 3.06 W and 5.94 W under V in = 200 m/s and ϕ = 1.0, respectively. While a longer separating plate length leads to a decrease in the exergy destruction and exergy loss. Exergy destruction and exergy loss change a little with d in and their values are around 1.6 W and 3.4 W, respectively. Exergy efficiency of the micro-combustor increases with the increase of V in and L 1 , but exhibits a non-monotonic variation with ϕ. A maximum exergy efficiency of 51.3% is achieved at V in = 200 m/s under ϕ = 1.0, d in = 0.20 mm and L 1 = 4 mm. In addition, the exergy efficiency decreases from 38.5% to 37.5% as d in increases from 0.20 mm to 0.30 mm under the same mass flow rate. [Display omitted] • The primary contributor to combustion irreversibility is chemical reaction. • Entropy generation by reaction rises with V in and ϕ , but reduces with L 1 and d in. • Entropy generation by heat conduction rises with V in and d in , but reduces with L 1. • Exergy loss from outer walls surpasses exergy destruction in the micro-combustor. • Exergy efficiency varies non-monotonically with equivalence ratio. [ABSTRACT FROM AUTHOR]

The aim of this paper is twofold. From the practical point of view, an enhanced model for the description of thermoelectric effects at nanoscale is proposed. From the theoretical point of view, instead, in the particular case of the proposed model, the equivalence between two classical techniques for the exploitation of the second law of thermodynamics is shown, i.e., Onsager's method and Liu's technique. An analysis of the heat-wave propagation is performed as well. [ABSTRACT FROM AUTHOR]

This article explores the relationship between the spontaneity of chemical reactions and time travel. It explains the concept of spontaneity in chemical reactions and its connection to the Second Law of Thermodynamics. The article also discusses the Gibbs free energy and how it determines the spontaneity of chemical reactions. Additionally, it delves into the concept of chemical potential and its relationship to Gibbs free energy and the Second Law of Thermodynamics. The author concludes by discussing the limitations of time travel and the potential for future scientific discoveries. [Extracted from the article]

Hybrid nanofluids provide several advantages over conventional fluids, including improved thermal characteristics, increased stability, customizable features, multifunctionality, and environmental advantages. Hybrid nanofluids are an appealing alternative for a variety of applications due to these benefits. This study aims to compute the non-similar solution of single-multi wall carbon nanotubes (SWCNTs-MWCNTs)-based hybrid nanofluid flow over an inclined extending surface. Heat transmission and flow are observed under the effects of quadratic convection, Darcy-Forchheimer quadratic drag forces, viscous dissipation, and non-linear thermal radiative heat flux. The velocity and thermal slip constraints are imposed at the inclined surface. For the model-based comparison, Xue, and Modified Hamilton Crosser thermal conductivity models for carbon nanotubes (CNTs) are adopted. The irreversibility of the system is also investigated using the second law of thermodynamics for the distinct CNTs-based thermal conductivity models. Non-similarity variables are adopted to convert nonlinear partial differential equations into dimensionless PDEs. Analytical modeling of non-similar systems is done by adopting non-similarity transformations up to second-level truncation, and the bvp4c technique is then used to compute the results numerically. The research found that at 75° of plate inclination, the Modified Hamilton Crosser model for CNTs outperforms the Xue model in terms of heat transfer rate. Further, entropy generation is significantly larger for the Xue model than for the Modified Hamilton Crosser model for CNTs against higher values of viscous dissipation and porosity parameters. It is also revealed that for opposing buoyancy force GR < 0, the temperature of the fluid escalates. This study possesses multiple applications including petroleum engineering, heat exchangers, environmental remediation, and biomedical applications. [ABSTRACT FROM AUTHOR]

In this paper, we present a model of inflation in the original form of Brans–Dicke (BD) theory without any modification and without adding any dark energy candidate. We consider a log function of the scale factor in the BD scalar field to discuss the inflationary era of the universe. We obtain the expressions for the deceleration parameter and the equation of state parameter, and plot their graphs against the cosmic scale factor. We observe that the universe starts with decelerated expansion and experiences an early time phase transition from a decelerated phase to an accelerated phase. After a very short period, the accelerated expansion ends in a decelerated expansion, showing the inflationary era of the cosmic evolution. To analyze the model on thermodynamic ground, we consider generalized second law of thermodynamics and observe that the law is satisfied within the model. Further, we study the stability of the model using the squared sound speed method. We plot the squared sound speed against cosmic time t and discuss the effects of the parameters on the stability of the model. We observe that for suitable values of the model parameters our model is stable. [ABSTRACT FROM AUTHOR]

This paper provides the groundwork for the most efficient design of freshwater generating systems that take advantage of waste heat from the main engines. In the desalination process, freshwater generators, whether in the form of shell and tube-type or plate-type, are employed. Merchant vessels primarily utilize submerged shell and tube-type evaporators to generate fresh water. The foundation for comprehending separation processes, energetics, and economics lies in the quantitative interpretation of the second law of thermodynamics, with a specific focus on exergy and its dissipation. This research suggests employing exergy analysis to utilize waste heat as a valuable resource in a single-effect desalination process to meet freshwater needs, considering practical aspects. The study involves analyzing a freshwater generator of the Shell and tube type situated at the Tolani Maritime Institute in Pune, India. Thermal properties are calculated and visually represented through a flow diagram using a C++ program. The assessment of exergy unveils the extent and distribution of unattainable work within a freshwater generator employing a shell and tube design, particularly concentrated in its key components: the evaporator, condenser, and brine section. These findings are contrasted with those from a Plate Type Heat Exchanger (PTHE) freshwater generator. The rate of exergy destruction in Plate Type Heat Exchanger freshwater generators is 29.33%, whereas in shell and tube-type freshwater generators, it is higher at 44.88%. [ABSTRACT FROM AUTHOR]

Lignite‐fired boilers usually encounter the insufficient drying capacity of the pulverizer due to the inherent drawback of high moisture content in fuel. In this study, four schemes of heat sources for temperature boosting of hot primary air are proposed for an ultra‐supercritical large‐scale single reheat lignite‐fired power plant according to heat sources such as inlet flue gas of air preheater (Scheme 1), the third stage extraction steam (Scheme 2), outlet steam of low‐temperature reheater (Scheme 3), and inlet flue gas of economizer (Scheme 4). The thermodynamic system models are built by using EBSILON Professional software. The thermodynamic performance of the four schemes is analyzed and compared from the perspectives of the first and second laws of thermodynamics. First law analysis indicates that the power generation standard coal consumption of Scheme 3 is reduced by 0.87, 0.42, and 0.04 g·kW−1·h−1 compared with Schemes 1, 2, and 4, respectively. Second law analysis indicates that the exergy loss of Schemes 2–4 is 3.7, 7.6, and 7.5 MW lower than that of Scheme 1. The present study may provide guidance for the energy efficiency improvement of lignite‐fired power plants. [ABSTRACT FROM AUTHOR]

We provide a short review of the recent developments in entropic cosmology based on two thermodynamic laws of the apparent horizon, namely the first and the second laws of thermodynamics. The first law essentially provides the change in entropy of the apparent horizon during the cosmic evolution of the universe; in particular, it is expressed by T d S = − d (ρ V) + W d V (where W is the work density and other quantities have their usual meanings). In this way, the first law actually links various theories of gravity with the entropy of the apparent horizon. This leads to a natural question—"What is the form of the horizon entropy corresponding to a general modified theory of gravity?". The second law of horizon thermodynamics states that the change in total entropy (the sum of horizon entropy + matter fields' entropy) with respect to cosmic time must be positive, where the matter fields behave like an open system characterised by a non-zero chemical potential. The second law of horizon thermodynamics importantly provides model-independent constraints on entropic parameters. Finally, we discuss the standpoint of entropic cosmology on inflation (or bounce), reheating and primordial gravitational waves from the perspective of a generalised entropy function. [ABSTRACT FROM AUTHOR]

This study presents numerical findings on the flow and heat transfer irreversibility when metal foams are partially filled in a horizontal pipe. A heater is embedded in the pipe's circumference with a known heat input. Aluminum metal foam, characterized by a pore density of 10 and porosity of 0.95, is placed next to the inner wall of the pipe to enhance heat transfer. To determine the optimal thickness of the metal foam for thermodynamic performance enhancement, metal foams of five different thicknesses (10–80 mm) are examined under forced convection heat transfer conditions. The study integrates the Darcy Extended Forchheimer and local thermal nonequilibrium models to predict flow and heat transfer characteristics through the metal foams. Validation of the numerical methodology is conducted by comparing the results with experimental data available in the literature. A novel aspect of this investigation is the application of the second law of thermodynamics to analyze the thermodynamic performance of metal foams. Exergy and irreversibility analyses are used to evaluate the thermodynamic performance, revealing that a pipe filled with metal foams up to a thickness of 40 mm exhibits superior thermodynamic performance compared to other cases examined in the study. [ABSTRACT FROM AUTHOR]

Why do we remember the past, and plan the future? We introduce a toy model in which to investigate emergent time asymmetries: the causal multibaker maps. These are reversible discrete-time dynamical systems with configurable causal interactions. Imposing a suitable initial condition or "Past Hypothesis", and then coarse-graining, yields a Pearlean locally causal structure. While it is more common to speculate that the other arrows of time arise from the thermodynamic arrow, our model instead takes the causal arrow as fundamental. From it, we obtain the thermodynamic and epistemic arrows of time. The epistemic arrow concerns records, which we define to be systems that encode the state of another system at another time, regardless of the latter system's dynamics. Such records exist of the past, but not of the future. We close with informal discussions of the evolutionary and agential arrows of time, and their relevance to decision theory. [ABSTRACT FROM AUTHOR]

We propose new implicit constitutive relations for the heat fluxes of a two-temperature mixture of fluids. These relations are frame-indifferent forms. However, classical explicit forms of the stress tensors and the interaction forces (specified as explicit forms of constitutive relations) as given in mixture theory are used. The focus here is to establish constraints imposed on the implicit terms in the heat fluxes due to the Second Law of Thermodynamics. Our analysis establishes that the magnitude of the explicit entropy production is equal to or greater than that of the implicit entropy production. [ABSTRACT FROM AUTHOR]

In the literature, one can find numerous modifications of Fourier's law, the first of which is the Maxwell–Cattaneo–Vernotte heat equation. Although this model has been known for decades and successfully used to model low-temperature damped heat wave propagation, its nonlinear properties are rarely investigated. This paper aims to present the functional relationship between the transport coefficients and the consequences of their temperature dependence, particularly focusing on thermal conductivity. These are the consequences of the second law of thermodynamics. Furthermore, we introduce a particular implicit numerical scheme in order to solve such nonlinear heat equations reliably, free from artificial numerical errors. We investigate the scheme's stability, dissipation, and dispersion attributes. We demonstrate the effect of temperature-dependent thermal conductivity on two different initial-boundary value problems, including time-dependent boundaries and heterogeneous initial conditions, for which we discuss the nontrivial constraints following irreversible thermodynamics. [ABSTRACT FROM AUTHOR]

This article reconsiders Hans Driesch's vitalism, as articulated in his English book The Science and Philosophy of the Organism, from a novel perspective. The central thesis posits that Driesch's vitalism was intricately intertwined with contemporary physical sciences, particularly the version of energy physics prevalent in the energetics movement at the turn of the twentieth century. More specifically, based on the conceptual framework provided by energeticists like Wilhelm Ostwald and Georg Helm, Driesch offered an intriguing treatment of the relationship between entelechy and energy within an updated Kantian philosophy of nature. This article reconstructs Driesch's approach by elucidating four points. First, Driesch asserted that an entelechy strictly adhered to the conservation of energy. Second, he posited that the entelechy was not a form of energy and thus did not constitute a special kind of bio-specific vital energy. Third, he identified the entelechy's most critical characteristic as its ability to suspend certain physico-chemical changes. Fourth, Driesch suggested that the entelechy influenced mechanical systems in a manner akin to Maxwell's demon, raising the possibility of contravening the second law of thermodynamics. This article also contextualizes Driesch's treatment within the broader development of energy physics in the latter half of the nineteenth century. In conclusion, this article offers some critical remarks on the peculiar historical phenomenon of chronic vitalism as identified by Driesch and others. [ABSTRACT FROM AUTHOR]

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We proposed the finite-time cycle model of a measurement-based quantum cooler, where the invasive measurement provides the power to drive the cooling cycle. Such a cooler may be regarded as an alternative thought experiment of Maxwell's demon. The measurement-feedback information is capable of moving heat from the cold to hot bath without any work input and even making the maximum coefficient of performance larger than the Carnot limit. The causes that this seemingly paradoxical result does not violate the laws of thermodynamics can be clearly explained through the derivation of a generalized Clausius inequality including the mutual information. [ABSTRACT FROM AUTHOR]

The regulation of energy associated with heat transfer is the most important problem in the food processing, chemical and biomedical engineering industries. Therefore, this investigation explores the heat transfer qualities of micropolar hybrid-nanofluid also considering entropy generation which has recently become central focus of research in the field of heat transfer processes. The purpose of this analysis is to explore the influence of magnetohydrodynamics (MHD), viscous dissipation, and heat radiation on the flow of hybrid-nanofluid with micropolar properties above an exponentially shrinking/stretching sheet. A mathematical model is constructed and the solution is acquired by utilizing numerical technique bvp-4c in MATLAB. The befitting usage of the second law of thermal physics helped in conducting the entropy production analysis. The study obtains numerical results for the governing equations, which reveal dual solutions when analyzing a shrinking sheet, contrary to a stretching sheet. The paper presents graphical depictions of the influence of different attributes upon micro-rotation, velocity, surface-friction, temperature, Nusselt number and also the entropy generation plus the Bejan number. Moreover, a comparison of heat transfer rates between conventional nanomaterial and hybrid-nanofluid is provided. The study concludes that dual solutions appear and the wall shear stress coefficient decreases as the values of micropolar parameter R 1 increase with critical values of λ being λ c = − 1. 2 8 , − 1. 3 4 and − 1. 3 7. Also thermal irreversibility, which results from fluid friction near the sheet rather than far from it, is more dominant than total entropy generation. [ABSTRACT FROM AUTHOR]

The second law of thermodynamics asserts that energy diffuses from hot to cold. The resulting temperature gradients drive the efficiencies and failures in a plethora of technologies. However, as the dimensionalities of materials shrink to the nanoscale regime, proper heat dissipation strategies become more challenging since the mean free paths of phonons become larger than the characteristic length scales. This leads to temperature gradients that are dependent on interfaces and boundaries, which ultimately can lead to severe thermal bottlenecks. Herein, we uncover a phenomenon which we refer to as 'phonon funneling', that allows the control of phonon transport to preferentially direct phonon energy away from geometrically confined interfacial thermal bottlenecks and into localized colder regions. This phenomenon supersedes heat diffusion based on the macroscale temperature gradients, thus introducing a nanoscale regime in which boundary scattering increases the phonon thermal conductivity of thin films, an opposite effect than what is traditionally realized. This work advances the fundamental understanding of phonon transport at the nanoscale and the role of efficient scattering methods for enhancing thermal transport. [ABSTRACT FROM AUTHOR]

We show that a set of thermally weakly coupled geometrically frustrated systems (GFSs), each of which is constraint to reside at negative Boltzmann temperatures, is in equilibrium cooler than its constituents. It may even exhibit positive temperatures at low energies. The challenge for the second law of thermodynamics arising from potential heat flow related to the gradient of temperatures between a GFS and its environment is resolved by considering the energy fluctuations above the ground state. They are comprised in the canonical temperature, derived from information theory. Whereas the gradient of Boltzmann temperatures gives the direction of the stochastic drift of the most probable state of a GFS within its environment, the canonical temperature gradient defines that of heat flow. [ABSTRACT FROM AUTHOR]

The design of a microchannel heat exchanger can be achieved using various approaches. The design includes various materials, such as ceramics, silicon, metals, and polymers, that are used to make microchannels, depending on their specific requirements. Polymers such as silicon, glass, and other polymeric materials are utilized on metallic substrates. The current study includes microchannels fabricated from metallic copper. Further, the design solutions do not consider the implications of the second law of thermodynamics. Hence, performing an energetic analysis of microchannels is imperative to design and assess thermodynamic systems that use them efficiently. One technique to improve a thermodynamic system's efficiency is using a well-designed microchannel heat exchanger with excellent energetic performance. This can be achieved by creating a thermodynamic system that eliminates energetic losses and limits only unavoidable losses. The use of high-conductivity material like copper also achieves this. To identify possible reasons for exergy loss and perhaps address them, a thorough energetic analysis of an existing heat exchanger is necessary. A microchannel heat exchanger with 19 microchannels in a flat tube is considered for this study. The study finds the energetic losses, which are useful for the thermal design of the heat exchanger. [ABSTRACT FROM AUTHOR]

Although violation of Kirchhoff's Law of Thermal Radiation has been claimed in a magneto-optic structure, it is shown that Kirchhoff's Law of Thermal Radiation has not been violated, noting that violation of Kirchhoff's Law of Thermal Radiation would imply that the Second Law of Thermodynamics has also been violated. [ABSTRACT FROM AUTHOR]

Through energy and exergy analysis, the present work revisits the combustion processes generated using different fuels (CH4, C3H8, H2, LPG, Natural gas and Biogas) under the same operating conditions. First, numerical computations, in which the turbulent dynamic k-ϵ model coupled with a probability density function (PDF) approach together with different sub-models that ensure the reliability of the results, are used. Then, the First and Second Laws of thermodynamics are applied to all fuel combustion cases considered previously to predict the energy loss, exergy destruction and their corresponding efficiencies. Next, variations in the air factor, the air inlet temperature and the fuel inlet temperatures are considered to analyse the response of combustion system performance as well as energy and exergy losses for the different fuels under investigation. The results show an amelioration of combustion parameters for the mixture of fuel and air using values of λ greater than 1. Also, the preheating of the inlet air temperature has a positive effect on energetic parameters. However, preheating the inlet fuel does not take a considerable role in the efficiency amelioration and loss reduction of the combustion system. It further turns out that biogas features higher energy efficiency compared to other fuels, at approximately 89.64%, while hydrogen fuel exhibits higher exergy efficiency at around 78.70% followed by biogas with 74.96%. [ABSTRACT FROM AUTHOR]

This investigation outlines the significance of MHD Falkner–Skan flow of non‐Newtonian fluid flow over a wedge. To study the non‐Newtonian flow, Casson fluid is taken. Additionally, this study explores heat and mass transport under the influence of viscous dissipation, Joule heating, and thermal radiation. This heat and mass transport investigation is carried out under the influence of thermal and concentration slip factors. Moreover, the entropy generation is also computed using the second law of thermodynamics. A set of nonlinear partial differential equations arises from the mathematical formulation of the problem. Similarity variables are then introduced to achieve a similarity solution. The leading differential equations are solved numerically using the Runge–Kutta‐4 method in conjunction with shooting techniques. Graphical representations are employed to demonstrate the physical significance of relevant parameters. The investigation presents and discusses the impact of various parameters on velocity, temperature, concentration and entropy profiles for three different positions of the wedge: stationary, forward‐moving, and backward‐moving. The main conclusions of the study are as follows: (1) Enhancing the magnetic parameter and wedge angle parameter leads to higher fluid velocity, (2) elevating both the Eckert and magnetic number results in a rapid escalation of fluid energy, (3) Skin friction coefficient increases gradually with an increase in the power law Falkner–Skan parameter. [ABSTRACT FROM AUTHOR]

The present investigation focuses on enhancing the efficiency of a vapor compression refrigeration system (VCRS) by proposing a Multiple Input Multiple Output (MIMO) control strategy based on the evaporator's two-phase length and superheat temperature. A moving boundary dynamic model for the VCRS is implemented using the Thermosys Matlab Toolbox. The study analyzes the influence of actuation parameters, specifically compressor speed and expansion valve opening, on control parameters, namely two-phase length and superheat temperature. A comprehensive analysis based on the first and second laws of thermodynamics is conducted across a wide range of operating conditions. Simulation results demonstrate that two-phase length can be effectively utilized as a control parameter by selecting operating points that maximize the system efficiency. Additionally, the study reveals that extending the evaporator's two-phase length to 80–90% of its limit increases system efficiency, enabling a reduction in compressor speed while maintaining the cooling capacity. [ABSTRACT FROM AUTHOR]

This paper explores how a reinterpretation of the generalized uncertainty principle as an effective variation of Planck's constant provides a physical explanation for a number of fundamental quantities and couplings. In this context, a running fine structure constant is naturally emergent and the cosmological constant problem is solved, yielding a novel connection between gravitation and quantum field theories. The model could potentially clarify the recent experimental observations by the DESI Collaboration that could imply a fading of dark energy over time. When applied to quantum systems and their characteristic length scales, a simple geometric relationship between energy and entropy is disclosed. Lastly, a mass–radius relation for both quantum and classical systems reveals a phase transition-like behavior similar to thermodynamical systems, which we speculate to be a consequence of topological defects in the universe. [ABSTRACT FROM AUTHOR]

Numerical modeling of immiscible two‐phase flow in deformable porous media has become increasingly significant due to its applications in oil reservoir engineering, geotechnical engineering and many others. The coupling between two‐phase flow and geomechanics gives rise to a major challenge to the development of physically consistent mathematical models and effective numerical methods. In this article, based on the concept of free energies and guided by the second law of thermodynamics, we derive a thermodynamically consistent mathematical model for immiscible two‐phase flow in poro‐viscoelastic media. The model uses the fluid and solid free energies to characterize the fluid capillarity and solid skeleton elasticity, so that it rigorously follows an energy dissipation law. The thermodynamically consistent formulation of the pore fluid pressure is naturally derived for the solid mechanical equilibrium equation. Additionally, the model ensures the mass conservation law for both fluids and solids. For numerical approximation of the model, we propose an energy stable and mass conservative numerical method. The method herein inherits the energy dissipation law through appropriate energy approaches and subtle treatments for the coupling between two phase saturations, the effective pore pressure and porosity. Using the locally conservative cell‐centered finite difference methods on staggered grids with the upwind strategies for saturations and porosity, we construct the fully discrete scheme, which has the ability to conserve the masses of both fluids and solids as well as preserve the energy dissipation law at the fully discrete level. In particular, the proposed method is an unbiased algorithm, that is, treating the wetting phase, the non‐wetting phase and the solid phase in the same way. Numerical results are also given to validate and verify the features of the proposed model and numerical method. [ABSTRACT FROM AUTHOR]

Thermodynamics is a vast area of knowledge with a debatable role in explaining the evolution of ecosystems. In the case of soil ecosystems, this role is still unclear due to difficulties in determining the thermodynamic functions that are involved in the survival and evolution of soils as living systems. The existing knowledge is largely based on theoretical approaches and has never been applied to soils using thermodynamic functions that have been experimentally determined. In this study, we present a method for the complete experimental thermodynamic characterization of soil organic matter. This method quantifies all the thermodynamic functions for combustion and formation reactions which are involved in the thermodynamic principles governing the evolution of the universe. We applied them to track the progress of soil organic matter with soil depth in mature beech forests. Our results show that soil organic matter evolves to a higher degree of reduction as it is mineralized, yielding products with lower carbon but higher energy content than the original organic matter used as reference. These products have higher entropy than the original one, demonstrating how the soil ecosystem evolves with depth, in accordance with the second law of thermodynamics. The results were sensitive to soil organic matter transformation in forests under different management, indicating potential applicability in elucidating the energy strategies for evolution and survival of soil systems as well as in settling their evolutionary states. [ABSTRACT FROM AUTHOR]

In this paper, we reconsider the concept of bulk viscosity in Brans–Dicke theory to study accelerated expansion of the universe in a flat Friedmann–Robertson–Walker metric. In recent works on bulk viscosity in Brans–Dicke theory, the power-law form of Brans–Dicke scalar field has been taken to explain recent phase transition of the universe, however, power-law form confronts constant deceleration parameter problem. Therefore, we consider recently proposed well-motivated logarithmic form of Brans–Dicke scalar field to discuss bulk viscous model in Brans–Dicke theory. We obtain the values of deceleration parameter and equation of state parameter for the model, and plot their graphs against the redshift parameter z. The plots show that the model is able to explain the recent phase transition of the universe and equation of state parameter shows the behavior of dark energy. Further, we apply two important analysis, namely, w − w ′ analysis and thermodynamic analysis to examine our model. The w − w ′ analysis shows that our model belong to thawing region and shows similarities with quintessence model. All the trajectories start from the point w ′ = 0 with different negative values of w having quintessence behavior. The thermodynamic analysis shows that the model satisfies generalized second law of thermodynamics. [ABSTRACT FROM AUTHOR]

Due to the widespread use of multi-generation systems utilizing renewable energy sources and the growing global demand for such systems from both economic and environmental considerations, numerous researchers have focused on the design and evaluation of their performance. To this end, this research presents a biomass-based multi-generation system with an innovative and practical design that can generate electricity, heat, and hydrogen. This system includes a modified gas turbine cycle, a supercritical CO 2 (SCO 2) cycle, a transcritical CO 2 (TCO 2) cycle, a proton exchange membrane (PEM) electrolyzer, and a PEM fuel cell unit. This study aims to evaluate the impact of various biomass sources (paper, wood, paddy husk, and municipal solid waste) on the system performance. The proposed system has been analyzed using the first and second laws of thermodynamics. This system uses the maximum capacity to produce power, heat and hydrogen. A fuel cell unit has been used to consume hydrogen and generate more electricity. In the basic mode, the system has energy and exergy efficiencies of 47.89% and 32.26%, respectively, and can produce 2.74 kg/h of hydrogen. The biomass fuel consumption rate within the system is 0.055 kg/s. The overall exergy destruction of the system amounts to 1240 kW, with the biomass boiler and the condenser being the components that experience the greatest exergy destruction, registering values of 535.5 kW and 432.3 kW, respectively. Notably, employing municipal waste as biomass increases the system's exergy efficiency to 33.16%. • To investigate a biomass-driven system for producing power, hydrogen, and heating. • To evaluate the impact of various biomass sources on the system performance. • To use PEME for hydrogen and PEMFC for power and heat production. [ABSTRACT FROM AUTHOR]

In this work, the flow of a hybrid Mo S 2 − Si O 2 /water nanofluid across a porous exponentially diminishing Riga surface with the effects of quadratic heat radiation is taken into account. We also considered the effects of mixed convection, slip velocity, and convective thermal boundary conditions. Before numerically solving the governing partial differential equations, the MATLAB function bvp4c was used to get a comprehensive description of all relevant flow characteristics. The ramifications of physical characteristics concerning fluid flow and thermal profile are investigated using graphs and tables. The primary objective of this study is to investigate the Nusselt number, skin friction coefficient, and entropy production. Using the second law of thermodynamics, the irreversibility factor is computed. For a given value of the mass suction parameter, the findings also indicate the occurrence of dual-nature solutions in the shrinking sheet area, with a stable upper solution branch and unstable bottom solution branch. In addition, the first solution produces a positive minimum eigenvalue, whereas the second solution produces a negative eigenvalue, showing the stability of the first solution. For heat transfer enhancement, the existence of quadratic thermal radiative parameter impacts is more advantageous. With a larger value for the modified Hartman number, the velocity field has expanded. Also, recent research demonstrates that raising the thermal Biot number enhances the thermal gradient. Increases in nanoparticle volume fraction and thermal radiation parameters lead to a commensurate rise in entropy production. Because of these findings, we can better regulate the temperature of various environments by controlling the flow of heat. [ABSTRACT FROM AUTHOR]

This research presents an exergy analysis of a gas turbine power plant situated in Assiut, Egypt, operating under high-temperature conditions. The aim of the study is to assess the performance of the simple gas turbine cycle and identify the sources of thermodynamic inefficiencies using the second law of thermodynamics as a basis for analysis. To accomplish this, a model was developed in EES software utilizing real operational data obtained from the plant's control system. The investigation focused on the impact of varying ambient temperature on the exergy efficiency, exergy destruction, and net power output of the cycle. The results revealed that the combustion chamber accounted for the highest exergy destruction, amounting to 85.22%. This was followed by the compressor at 8.42% and the turbine at 6.36%. The overall energy and exergy efficiencies of the system were determined to be 28.8% and 27.17%, respectively. Furthermore, the study examined the effects of increasing ambient temperature from 0 to 45°C on the system's performance. It was observed that as the temperature rose, the overall exergy efficiency decreased from 27.91 to 26.63%. Simultaneously, the total exergy destruction increased from 126,407 to 138,135 kW. Additionally, the net power output exhibited a decline from 88,084 to 84,051 kW across the same ambient temperature range. These findings highlight the significant influence of ambient temperature on the thermodynamic performance of gas turbine power plants. As temperature rises, a greater amount of exergy is lost, resulting in reduced efficiency and diminished net power output. Therefore, optimizing the design of the combustion chamber is crucial for mitigating the adverse effects of hot weather conditions. The insights obtained from this study can be utilized to enhance the design and operation of gas turbine plants operating in hot climates. [ABSTRACT FROM AUTHOR]

Living cells have spontaneous ultraweak photon emission derived from metabolic reactions associated with physiological conditions. The ORCA-Quest CMOS camera (Hamamatsu Photonics, Japan) is a highly sensitive and essential tool for photon detection; its use with a microscope incubator (Olympus) enables the detection of photons emitted by embryos with the exclusion of harmful visible light. With the application of the second law of thermodynamics, the low-entropy energy absorbed and used by embryos can be distinguished from the higher-entropy energy released and detectable in their environment. To evaluate higher-entropy energy data from embryos, we developed a unique algorithm for the calculation of the entropy-weighted spectral fractal dimension, which demonstrates the self-similar structure of the energy (photons) released by embryos. Analyses based on this structure enabled the distinction of living and degenerated mouse embryos, and of frozen and fresh embryos and the background. This novel detection of ultra-weak photon emission from mouse embryos can provide the basis for the development of a photon emission embryo control system. The ultraweak photon emission fingerprints of embryos may be used for the selection of viable specimens in an ideal dark environment. [ABSTRACT FROM AUTHOR]

We have now identified two thermodynamically distinct types (A and B) of energetic processes naturally occurring on Earth. Type-A energy processes, such as classical heat engines, apparently well follow the second law of thermodynamics; Type-B energy processes, such as the newly discovered thermotrophic function that isothermally utilizes environmental heat energy to perform useful work in driving ATP synthesis, follow the first law of thermodynamics (conservation of mass and energy) but do not have to be constrained by the second law, owing to their special asymmetric functions. Several Type-B energy processes such as asymmetric function-gated isothermal electricity production and epicatalysis have been created through human efforts. The innovative efforts in Type-B processes to enable isothermally utilizing endless environmental heat energy could help to liberate all peoples from their dependence on fossil fuel energy, thus helping to reduce greenhouse gas CO2 emissions and control climate change towards a sustainable future for humanity on Earth. In addition to the needed support for further research, development, and commercialization efforts, currently, better messaging and education on Type-B energetic processes are also highly needed to achieve the mission. [ABSTRACT FROM AUTHOR]

This study uses an equal proportion of two different biodiesels obtained from waste cooking, neem oil and blended with diesel fuel to investigate the diesel engine's combustion, emission, and exergetic performance. Al2O3 nano additive of 50ppm and 100ppm is used in diesel-biodiesel blends of B10 and B20 to improve the overall performance of the engine. The experimentations are conducted on a single-cylinder, four-stroke diesel engine at a fixed speed. The results reveal that 50ppm in the B10 blend improves the combustion with high exergetic efficiency and low exergy destruction. The various heat loss factors like exhaust, cooling, and radiation from the engine are determined using the second law of thermodynamics and the loss factor results reveal that the blend B10 with 50ppm shows high useful work of 32.84% with low radiation losses of 32.05% at 75% load. At 100% load, the blend B20 with 50ppm dominate the other blends. Finally, the addition of Al2O3 in biodiesel blends refines the combustion as a result, low exhaust emissions of NOx, CO, UHC, and smoke are reported. [ABSTRACT FROM AUTHOR]

We present a partition of quantum observables in an open quantum system that is inherited from the division of the underlying Hilbert space or configuration space. It is shown that this partition leads to the definition of an inhomogeneous continuity equation for generic, non-local observables. This formalism is employed to describe the local evolution of the von Neumann entropy of a system of independent quantum particles out of equilibrium. Crucially, we find that all local fluctuations in the entropy are governed by an entropy current operator, implying that the production of entanglement entropy is not measured by this partitioned entropy. For systems linearly perturbed from equilibrium, it is shown that this entropy current is equivalent to a heat current, provided that the system-reservoir coupling is partitioned symmetrically. Finally, we show that any other partition of the coupling leads directly to a divergence of the von Neumann entropy. Thus, we conclude that Hilbert-space partitioning is the only partition of the von Neumann entropy that is consistent with the laws of thermodynamics. [ABSTRACT FROM AUTHOR]

Entropy generation analysis is a useful method for studying the relationship between heat transfer and pressure drop in flow boiling. The flow boiling process in an actual refrigeration system is inevitably affected by oil. Therefore, the effect of oil on entropy generation needs to be investigated. A new non-azeotropic ternary refrigerant mixture, R447A, was selected as working fluid. Subsequently, flow boiling entropy generation models of R447A with and without oil were established. The effects of individual parameters on entropy generation were investigated. The entropy generation per unit tube length under different conditions was proposed as the benchmark for comparison. The results show that there is an optimal mass flux corresponding to minimum entropy generation per unit tube length at a specific oil concentration, and optimal mass flux decreases with increasing oil concentration. The tube diameter also affects the optimal mass flux of the fluid with oil, which increases with decreasing tube diameter and is smaller than that without oil for the same diameter tube. When the oil concentration is 0–4.95%, the total entropy generation exhibits a decreasing trend. Therefore, within the scope of this research, the addition of oil is beneficial for reducing the entropy generation of heat exchangers. [ABSTRACT FROM AUTHOR]

In this article, by developing the net radiation method, the entropy generation of surface radiation in an inclined enclosure with natural convection has been investigated. The governing equations are solved by the streamvorticity function with the finite difference method and the surface radiation equations are solved with the net spectral radiation method. Surface radiation entropy generation includes radiation entropy in the field and in the matter. In this method, by solving the equations of net radiation in a spectral form, the intensity of the incoming and outgoing radiation from the surfaces is obtained, then the radiation entropy in the matter and the intensity of the spectral radiation entropy are calculated, and finally, the radiation entropy in the field is calculated using the intensity of the spectral radiation entropy. In order to accurately calculate the entropy generation of surface radiation, the developed net radiation method has been validated with the second law of thermodynamics. The effect of Rayleigh number, emissivity and enclosure angle on entropy generation is investigated. The results show that the surface radiation entropy generation decreases with the increase of the enclosure angle. The lowest entropy generation occurs at an angle of 90 degrees, when the hot wall is the lower wall of the enclosure. Also, 85% of the total entropy generation is due to surface radiation. So that the entropy generation due to the effect of surface radiation increases by 520% compared to the case where surface radiation is ignored [ABSTRACT FROM AUTHOR]

This study conducts the thermodynamics analysis of creeping viscous nanofluid influenced by metachronical waves in an inclined ciliated tube and investigates the effects of magnetic field, porous medium and Hall current. Moreover, heat transport analysis is performed to consider the viscous dissipation phenomena. Thermal conductivity of the fluid is made more effective by adopting water-based titanium dioxide nanoparticles. TiO 2 is chosen as it has many remarkable implications in nanobio-sensing, medical implants, drug delivery and antibacterial fields. The governing equations are formulated which are converted into ordinary differential system by taking into account the similarity variables. The analytical solution are obtained for momentum, pressure gradient and energy profiles. It is found that the entropy generation is an increasing function of the Eckert number, Prandtl number and dimensionless temperature difference. Both Darcy and Eckert numbers enhance the energy of flow system. The fluid velocity drops quickly with increasing magnetic parameter. [ABSTRACT FROM AUTHOR]

Einstein's gravity in AdS space coupled to nonlinear electrodynamics (NED) with two parameters is studied. We investigate magnetically charged black holes. The metric and mass functions and their asymptotic are obtained showing that black holes may have one or two horizons. Thermodynamics in extended phase space was studied and it was proven that the first law of black hole thermodynamics and the generalized Smarr relation hold. The magnetic potential and the vacuum polarization conjugated to coupling (NED parameter), are computed and depicted. We calculate the Gibbs free energy and heat capacity. [ABSTRACT FROM AUTHOR]

The paper investigates the problem of the time arrow in terms of artistic creation. The statistical model of artwork signal processing is established in order to identify a duality relation between psychological and intrinsic time. The intrinsic time is linked to the time operator of wavelets, and the psychological one is metaphorically related to the spatial domain of an artwork. The increase of irreducible randomness along the timeline is formulated by the second law of thermodynamics. The dual statement concerns an increase in statistical complexity, which is the definition of self-organization. In that manner, two arrows of time which are opposed and dual to each other are recognized. The authors have indicated a link to the theory of musical forms, the originality issue, and the perspective problem. Some repercussions for art theory, neuroaesthetics, and psychophysics have also been implied. [ABSTRACT FROM AUTHOR]

Within the scope of this study, a thermoeconomic analysis was carried out for Akkuyu Nuclear Power Plant (ANPP), the first nuclear power plant of Türkiye. As a result of the analysis, it is aimed to reduce the cost of energy production and prevent thermal pollution at the same time by converting the heat discharged into the environment into useful heat due to the working principle of NPP. Thermodynamic analysis was performed in the Engineering Equation Solver (EES) program using equipment values equivalent to ANPP. Cost analysis was performed using the specific exergy costing (SPECO) method, which is based on the second law of thermodynamics and is the most widely used cost analysis method. The study concludes that the energy efficiency is 35%, while the economic analysis shows that the best case has an exergy efficiency of 68% with a payback period of 7–8 years, and an electricity cost of $0.0196 per kWh. It is possible to use the heat discharged from the plant indirectly in district heating (heating, hot water needs of the lodgings, guesthouses in the facility), greenhouse heating, agricultural drying and heating, considering the geographical conditions and livelihood of the region. Thus, 68% of the waste heat was utilized, the unit cost of the energy produced was reduced and at the same time thermal pollution was reduced at the same rate. The results of the study can contribute to the efforts preventing energy waste, thermal environmental pollution, and reducing greenhouse gas emissions. Additionally, it could aid in the development of more energy-efficient and environmentally friendly power generation systems, including pioneering nuclear power plants in developing countries. [ABSTRACT FROM AUTHOR]