Thermodynamic Relations Research Articles

Nuclear reactions in gaseous stars: Perspectives from kinetic theory and thermodynamics

In the Standard Model of gaseous stars, temperature is primary both in the initiation of thermonuclear reactions to form heavier elements and the emission of radiation. These processes have been described using thermodynamic expressions. However, within any given thermodynamic relation, not only must units balance on each side, but so must thermodynamic character. Temperature, whether or not equilibrium conditions are established, must always be intensive in macroscopic thermodynamics, and mass must be extensive. This ensures that the laws of thermodynamics are respected. The theory of temperatures and nuclear reactions within gaseous stars is constructed from the kinetic theory of an ideal gas, by which temperature is introduced, in combination with gravitational and Coulomb forces. The resulting thermodynamic relations impart a nonintensive character to temperature and a nonextensive character to mass. Consequently, the theory of nuclear reactions in gaseous stars is invalid. Deprived of the only theoretical means by which the Standard Model justifies stellar nuclear reactions, the theory of gaseous stars is not viable. The most reasonable alternative rests in lattice confinement fusion and the recognition that the stars are comprised of condensed matter, namely metallic hydrogen.

Thermodynamics of Pickup Ions in the Heliosphere

The paper shows the thermodynamic nature of the evolution of the pickup ion (PUI) distributions through their incorporation and subsequent expansion as the solar wind moves outward through the heliosphere. In particular, the PUI expansive cooling is connected to thermodynamic polytropic processes and the thermodynamic kappa parameter. Previously, the characterization of the cooling was phenomenologically given by a “cooling index” α, which is the exponent involved in the power-law relationship between PUI speed and position. Here, we develop the relationship between the cooling and polytropic indices. Then, we show the connection between the cooling index and the thermodynamic parameter kappa. Finally, we verify the derived thermodynamic relations with direct heliospheric observations over varying distances from the Sun. Going forward, we suggest that studies of PUIs seeking to understand the underlying physics of these important particles rely on the thermodynamic parameter of kappa, and its association with the polytropic index, and not on an ad hoc cooling index.

Enhancing economic and performance effectiveness of a geo-solar system using multi aspect artificial neural network

Geo-solar systems, comprising ground-source heat pumps (GSHP) and solar thermal collectors, offer promising solutions for sustainable space heating and hot water provision in residential buildings. However, optimizing these systems for maximum energy efficiency and cost-effectiveness remains a challenge. In this context, this study presents a comprehensive approach to enhancing the performance and cost-effectiveness of geo-solar systems. The proposed methodology integrates artificial neural network (ANN) techniques and multi-aspect optimization to optimize system parameters. The detailed of building mathematical model incorporating energy and exergy equations, thermodynamic, and economic relations for all system components. The neural network model inputs to the include five neurons represents Geothermal temperature, Solar radiation levels, System pressure levels, Ambient temperature, and Operational time, and the model outputs represent Energy efficiency and Exergy destruction rate. Through the training of ANN using simulation data and the application of a multi-objective genetic algorithm, the system is optimized for energy efficiency, cost, and environmental impact simultaneously. The results of analysis show that the exergy efficiency of system is 22.02 % and turbine generates 1963 kW. Changes in P10, ranging from 2000 to 3400 kPa leads to the exergy destruction reduction from 8350 kW to 8000 kW, while the other parameters exhibit an increasing trend.

Study of shear Alfve’n waves with Landau quantization effect in degenerate relativistic plasma

In a ground breaking endeavor, we investigate a fundamental quantum property of fermions, specifically electrons, within a non-uniform quantized magnetic field, unveiling novel insights into shear Alfve’n waves in the relativistic realm of quantum plasma, particularly within the context of a degenerate Fermi gas. Employing the quantum magnetohydrodynamic model, we delve into the profound implications of the Landau quantization effect. This quantum phenomenon holds paramount importance across diverse fields such as condensed matter physics, astrophysics, and quantum information. Our study focuses on a plasma composed of degenerate relativistic electrons coexisting with cold fluid ions, which are non-degenerate particles. The findings of this research reveal substantial modifications in the thermodynamic, kinetic, and dispersion relation characteristics of shear Alfve’n waves when subjected to a non-uniform quantized magnetic field. This exploration offers a pioneering perspective on the intricate interplay between quantum physics and plasma dynamics, with implications for a wide array of scientific disciplines.

Uncertainty relation for symmetric Petz-Rényi relative entropy.

Holevo introduced a fidelity between quantum states that is symmetric and as effective as the trace distance in evaluating their similarity. This fidelity is bounded by a function of the trace distance, a relationship to which we will refer as Holevo's inequality. More broadly, Holevo's fidelity is part of a one-parameter family of symmetric Petz-Rényi relative entropies, which in turn satisfy a Pinsker's-like inequality with respect to the trace distance. Although Holevo's inequality is tight, Pinsker's inequality is loose for this family. We show that the symmetric Petz-Rényi relative entropies satisfy a tight inequality with respect to the trace distance, improving Pinsker's and reproducing Holevo's as a specific case. Additionally, we show how this result emerges from a symmetric Petz-Rényi uncertainty relation, a result that encompasses several relations in quantum and stochastic thermodynamics.

Cleaner reactive dyeing with the recycled dyeing wastewater

In order to recycle water and inorganic salts, sodium persulphate (SPS) was used to degrade the C.I. Reactive Red 195 (RR195) dyeing wastewater. The thermodynamic and kinetic relationships of RR195 dyeing in cleaner and conventional dyeing processes were analyzed and compared. The feasibility of the one-bath cyclic dyeing in the recycled dyeing wastewater was confirmed through the properties of dye utilization, color parameters and energy conservation. The appropriate conditions were 0.3 g/L of SPS and treatment at 95 °C for 30 min, which resulted in a decolorization rate of 99.7% for the dyeing wastewater, mainly due to the action of radical sulfate. When cotton fabric was dyed with the cleaner dyeing, the kinetic was pseudo-second-order and the thermodynamic was Freundlich adsorption. There was a 47.5% reduction in half dyeing time, a greater diffusion coefficient and standard affinity, and lower entropy and enthalpy values when dyeing in reused wastewater. Cotton fabrics were dyed with the proposed cleaner dyeing process, which reduced the amount of water and inorganic salt by 95.8% and 89.8%, respectively. The total organic carbon (TOC), biochemical oxygen demand (BOD5) and chemical oxygen demand (COD) were 53.6%, 69.8% and 42.6% lower than the conventional dyeing process, respectively. The recommended technology not only reduces the amount of dyeing wastewater but also enables the recycling of inorganic salts and water, which makes great progress in the textile industry.

A comparative study of surfactant-treated natural latex foam morphology, thermodynamic relationships and energy absorption: Talalay vs. dunlop processing

This study investigates the relationships between the morphology, energy absorption, and thermodynamic parameters of natural latex foams (NLFs) processed by the Dunlop and in-house Talalay methods, using different surfactant blends. Both methods involved mixing, moulding, and heating; the additional steps for the Talalay method involved cooling and gelation, a gel-freezing technique wherein the frozen foam is exposed to CO2 gas, inducing its transformation into a gel. The morphology of the internal structure of the NLFs was studied using 2D scanning electron micrographs and 3D micro- computerised tomography images. Two different surfactants, potassium laurate and pluronic, were used. Adding the blended surfactants reduced the porosity and increased the foam density of the NLF samples, improving mechanical properties. The cell size distribution of the NLF samples prepared using the Talalay method was broader than that of those prepared using the Dunlop method. In terms of the mechanical properties and energy absorption capabilities, the Talalay process resulted in samples with 20% lower compressive strength and 7% lower energy absorption than the control sample. A power-law relationship between the energy absorption per unit volume and the compression speed of the different foam samples was also observed. The ratio of the internal energy to the total compression force of the NLF samples prepared using the Talalay process was also lower than those prepared using the Dunlop process. The empirical insights derived from this study show how the mechanical properties and process technology associated with the producing of material foams could be improved.

A Multiphysics Thermoelastoviscoplastic Damage Internal State Variable Constitutive Model including Magnetism.

We present a macroscale constitutive model that couples magnetism with thermal, elastic, plastic, and damage effects in an Internal State Variable (ISV) theory. Previous constitutive models did not include an interdependence between the internal magnetic (magnetostriction and magnetic flux) and mechanical fields. Although constitutive models explaining the mechanisms behind mechanical deformations caused by magnetization changes have been presented in the literature, they mainly focus on nanoscale structure-property relations. A fully coupled multiphysics macroscale ISV model presented herein admits lower length scale information from the nanoscale and microscale descriptions of the multiphysics behavior, thus capturing the effects of magnetic field forces with isotropic and anisotropic magnetization terms and moments under thermomechanical deformations. For the first time, this ISV modeling framework internally coheres to the kinematic, thermodynamic, and kinetic relationships of deformation using the evolving ISV histories. For the kinematics, a multiplicative decomposition of deformation gradient is employed including a magnetization term; hence, the Jacobian represents the conservation of mass and conservation of momentum including magnetism. The first and second laws of thermodynamics are used to constrain the appropriate constitutive relations through the Clausius-Duhem inequality. The kinetic framework employs a stress-strain relationship with a flow rule that couples the thermal, mechanical, and magnetic terms. Experimental data from the literature for three different materials (iron, nickel, and cobalt) are used to compare with the model's results showing good correlations.

Thermodynamic Geometry of Nonequilibrium Fluctuations in Cyclically Driven Transport.

Nonequilibrium thermal machines under cyclic driving generally outperform steady-state counterparts. However, there is still lack of coherent understanding of versatile transport and fluctuation features under time modulations. Here, we formulate a theoretical framework of thermodynamic geometry in terms of full counting statistics of nonequilibrium driven transports. We find that, besides the conventional dynamic and adiabatic geometric curvature contributions, the generating function is also divided into an additional nonadiabatic contribution, manifested as the metric term of full counting statistics. This nonadiabatic metric generalizes recent results of thermodynamic geometry in near-equilibrium entropy production to far-from-equilibrium fluctuations of general currents. Furthermore, the framework proves geometric thermodynamic uncertainty relations of near-adiabatic thermal devices, constraining fluctuations in terms of statistical metric quantities and thermodynamic length. We exemplify the theory in experimentally accessible driving-induced quantum chiral transport and Brownian heat pump.

Thermodynamic analysis of energy coupling by determination of the Onsager phenomenological coefficients for a 3×3 system of coupled chemical reactions and transport in ATP synthesis and its mechanistic implications

The nonequilibrium coupled processes of oxidation and ATP synthesis in the fundamental process of oxidative phosphorylation (OXPHOS) are of vital importance in biosystems. These coupled chemical reaction and transport bioenergetic processes using the OXPHOS pathway meet >90% of the ATP demand in aerobic systems. On the basis of experimentally determined thermodynamic OXPHOS flux-force relationships and biochemical data for the ternary system of oxidation, ion transport, and ATP synthesis, the Onsager phenomenological coefficients have been computed, including an estimate of error. A new biothermokinetic theory of energy coupling has been formulated and on its basis the thermodynamic parameters, such as the overall degree of coupling, q and the phenomenological stoichiometry, Z of the coupled system have been evaluated. The amount of ATP produced per oxygen consumed, i.e. the actual, operating P/O ratio in the biosystem, the thermodynamic efficiency of the coupled reactions, η, and the Gibbs free energy dissipation, Φ have been calculated and shown to be in agreement with experimental data. At the concentration gradients of ADP and ATP prevailing under state 3 physiological conditions of OXPHOS that yield Vmax rates of ATP synthesis, a maximum in Φ of ∼0.5J(hmgprotein)−1, corresponding to a thermodynamic efficiency of ∼60% for oxidation on succinate, has been obtained. Novel mechanistic insights arising from the above have been discussed. This is the first report of a 3 × 3 system of coupled chemical reactions with transport in a biological context in which the phenomenological coefficients have been evaluated from experimental data.

Fundamental heat and entropy transfer mechanisms of convection underlying the first and second laws for an unsteady multiport system and their applications in parallel flow heat exchangers

Although thermal convection is ubiquitous in nature and technology, it has long been argued whether convection can be considered as an independent mode of heat transfer. Here, we show that pure convection mode is generally recognized from the classical first and second laws via mass flow by rooting the unsteady mass conservation relation through an equivalent multiport system. The fundamental distinction is made between convection driven by the thermal and entropy potential differences and mass flow accompanied by zero potential difference. The constitutive relations of the convective heat and entropy fluxes and their thermodynamic relationship are developed in terms of their potential differences with the exponential distribution of temperature difference in a compressible flow. In the absence of work transfer, the first and second laws are simply expressed by the standard Maxwell’s electromagnetic type equations via the total heat and entropy flux vectors. The pure convection theory is applied to a parallel-flow heat exchanger and the linear temperature difference distribution is obtained for both streams via the first-law definitions of the convective and overall heat transfer coefficients in an internal flow. The entropy generation rate inside a heat exchanger is recalculated and indicated to be driven by the difference between the reciprocal of outlet temperatures of two streams, from which the entropy generation number between outlets is developed to eliminate the entropy generation paradox. The present linear temperature difference profiles agree well with the experimental data, and the outlet entropy generation number is also justified by comparing with the previous nondimensionalizing entropy generation numbers.

Out-of-Equilibrium Fluctuation-Dissipation Bounds.

We prove a general inequality between the charge current and its fluctuations valid for any weakly interacting coherent electronic conductor and for any stationary out-of-equilibrium condition, thereby going beyond established fluctuation-dissipation relations. The developed fluctuation-dissipation bound saturates at large temperature bias and reveals additional insight for heat engines, since it limits the output power by power fluctuations. It is valid when the thermodynamic uncertainty relations break down due to quantum effects and provides stronger constraints close to thermovoltage.

Compound-choking theory and artificial neural networks-based hybrid modeling for supersonic ejectors

As the core component of ejector refrigeration systems, the research of ejector mechanisms has always been a hot topic. Based on the compound-choking theory, this paper studies the relationship between the entrainment ratio and critical back pressure and designs a neural network-based online error compensation mechanism for supersonic ejectors. Firstly, a thermodynamic model of the ejector is developed by combining the ideal gas model, the compound-choking theory, and the constant-pressure mixing theory. Then, the thermodynamic relationship between the entrainment ratio and critical back pressure is derived by introducing the idea of a hypothetical mixing cross section. Compared with the existing results, our method is able to improve critical back pressure prediction accuracy by virtue of the actual entrainment ratio. Therefore, a new adaptive error compensation algorithm is proposed for supersonic ejectors based on neural networks. Thus, the proposed scheme can be regarded as a hybrid modeling method for supersonic ejectors, which combines thermodynamic laws and data-driven artificial intelligence algorithms. Experimental data from ejector refrigeration systems with R141b, R245fa, water vapor and R134a are used in this paper to verify the validity of the model. The simulation results show that our method can effectively predict the critical back pressure, and all the prediction errors are less than 10%.

Kinetic investigation of sulfur corrosion: First principles calculations

The expressions of two important kinetic parameters (chemical activation energy of electrode reaction and absolute potential of equilibrium state) that determine the reaction rate during the anodic dissolution reaction are derived from the thermodynamic and kinetic relationships of the anodic dissolution reaction, the relationship between absolute potential and current density in the anode dissolution process is constructed. Under the framework of first principles, the calculation model of the electrochemical corrosion anodic dissolution reaction is proposed. Density functional theory study of the process of dissolving Fe atoms from the surface of Fe(111) alloy models in vacuum and explicit water molecules. The addition of water molecules and sulfur atoms promotes charge transfer during dissolution and increases the corrosion rate, while water molecules reduce the work function, while S goes increases the work function. Through the corrosion current density model of activation energy, the role of alloy dissolution kinetics with different alloys added was explored. The analysis shows that the addition of Mn and Cr can greatly reduce the anodic corrosion rate and increase the corrosion resistance of Fe.

Energieflexibilisierung von Kälteversorgungssystemen

Abstract In order to reduce the energy-related operating costs of industrial cooling supply systems, demand side management becomes more and more economically attractive in the face of increasing electricity price fluctuations. However, the realization of this potential usually fails due to implementation. In order to reduce the impediments to implementation, this paper presents a rule-based model predictive approach to operational optimization based on thermodynamic relationships and logical decision criteria. The optimization approach is finally validated on a simulation model as well as on a real climate room and leads to realized operating cost savings of up to 21 %.

Coordination Variations within Binuclear Copper Dioxygen-Derived (Hydro)Peroxo and Superoxo Species; Influences upon Thermodynamic and Electronic Properties.

Copper ion is a versatile and ubiquitous facilitator of redox chemical and biochemical processes. These include the binding of molecular oxygen to copper(I) complexes where it undergoes stepwise reduction-protonation. A detailed understanding of thermodynamic relationships between such reduced/protonated states is key to elucidate the fundamentals of the chemical/biochemical processes involved. The dicopper(I) complex [CuI2(BPMPO-)]1+ {BPMPOH = 2,6-bis{[(bis(2-pyridylmethyl)amino]methyl}-4-methylphenol)} undergoes cryogenic dioxygen addition; further manipulations in 2-methyltetrahydrofuran generate dicopper(II) peroxo [CuII2(BPMPO-)(O22-)]1+, hydroperoxo [CuII2(BPMPO-)(-OOH)]2+, and superoxo [CuII2(BPMPO-)(O2•-)]2+ species, characterized by UV-vis, resonance Raman and electron paramagnetic resonance (EPR) spectroscopies, and cold spray ionization mass spectrometry. An unexpected EPR spectrum for [CuII2(BPMPO-)(O2•-)]2+ is explained by the analysis of its exchange-coupled three-spin frustrated system and DFT calculations. A redox equilibrium, [CuII2(BPMPO-)(O22-)]1+ ⇄ [CuII2(BPMPO-)(O2•-)]2+, is established utilizing Me8Fc+/Cr(η6-C6H6)2, allowing for [CuII2(BPMPO-)(O2•-)]2+/[CuII2(BPMPO-)(O22-)]1+ reduction potential calculation, E°' = -0.44 ± 0.01 V vs Fc+/0, also confirmed by cryoelectrochemical measurements (E°' = -0.40 ± 0.01 V). 2,6-Lutidinium triflate addition to [CuII2(BPMPO-)(O22-)]1+ produces [CuII2(BPMPO-)(-OOH)]2+; using a phosphazene base, an acid-base equilibrium was achieved, pKa = 22.3 ± 0.7 for [CuII2(BPMPO-)(-OOH)]2+. The BDFEOO-H = 80.3 ± 1.2 kcal/mol, as calculated for [CuII2(BPMPO-)(-OOH)]2+; this is further substantiated by H atom abstraction from O-H substrates by [CuII2(BPMPO-)(O2•-)]2+ forming [CuII2(BPMPO-)(-OOH)]2+. In comparison to known analogues, the thermodynamic and spectroscopic properties of [CuII2(BPMPO-)] O2-derived adducts can be accounted for based on chelate ring size variations built into the BPMPO- framework and the resulting enhanced CuII-ion Lewis acidity.

Determination of operating temperature in main generator of a two-stage absorption refrigeration machine working on an aqueous solution of lithium bromide

This paper examines the thermal characteristics of a two-stage absorption refrigeration machine. When carrying out a numerical analysis, it turned out that the secondary generator’s temperature was not constant, and it was also found that the coefficient of thermal performance of this cycle increased significantly at the beginning, then stabilized at a certain value for the temperature degree of the primary generator. But this result is not the right value for calculating the absorption refrigeration cycle; it might cause crystallization inside the cycle and This was verified based on the thermodynamic relationship chart (h-X-T) for LiBr-water solution. In addition, the decisive point for determining the appropriate temperature is to study the change in refrigeration capacity in the process when the temperature of the generator changes. In this case, the design temperature for the primary generator should be in the range between the temperature corresponding to the highest refrigeration capacity and the temperature far from the crystallization phenomenon.

New Findings on the Crystal Polymorphism of Imepitoin.

Scientific and industrial reasons dictate the study of the solid state of imepitoin, a highly safe and tolerable anticonvulsant drug used in the therapy of epileptic dogs that was approved in the Europe Union in 2013. Our investigations allowed us to discover the existence of a new polymorph of imepitoin, which finds itself in a monotropic relationship with the crystalline form (polymorph I) already known and present on the market. This form (polymorph II), obtained by crystallization from xylene, remains metastable under ambient conditions for at least 1 year. Both solid forms were characterized by thermal (DSC and TGA), spectroscopic (FT-IR and Raman), microscopic (SEM and HSM), and diffractometric techniques. The thermodynamic relationship between the two polymorphs (monotropic) is such that it is not possible to study the melting of polymorph II, not even by adopting appropriate experimental strategies. Our measurements highlighted that the melting peak of imepitoin actually also includes an onset of melt decomposition. The ab initio structure solution, obtained from synchrotron X-ray powder diffraction data collected at room temperature, allowed us to determine the crystal structure of the new polymorph (II). It crystallizes in the monoclinic crystal structure, P21/c space group (#14), with a = 14.8687(6) Å, b = 7.2434(2) Å, c = 12.5592(4) Å, β = 107.5586(8)°, V = 1289.61(8) Å3, and Z = 4.

Exact solution to quantum dynamical activity.

The quantum dynamical activity constitutes a thermodynamic cost in trade-off relations such as the quantum speed limit and the quantum thermodynamic uncertainty relation. However, calculating the quantum dynamical activity has been a challenge. In this paper, we present the exact solution for the quantum dynamical activity by deploying the continuous matrix product state method. Moreover, using the derived exact solution, we determine the upper bound of the dynamical activity, which comprises the standard deviation of the system Hamiltonian and jump operators. We confirm the exact solution and the upper bound by performing numerical simulations.

Current Fluctuations in Open Quantum Systems: Bridging the Gap Between Quantum Continuous Measurements and Full Counting Statistics

Continuously measured quantum systems are characterized by an output current, in the form of a stochastic and correlated time series, which conveys crucial information about the underlying quantum system. The many tools used to describe current fluctuations are scattered across different communities: quantum opticians often use stochastic master equations, while a prevalent approach in condensed-matter physics is provided by full counting statistics. These, however, are simply different sides of the same coin. Our goal with this tutorial is to provide a unified toolkit for describing current fluctuations. This not only provides novel insights, by bringing together different fields in physics, but also yields various analytical and numerical tools for computing quantities of interest. We illustrate our results with various pedagogical examples and connect them with topical fields of research, such as waiting-time statistics, quantum metrology, thermodynamic uncertainty relations, quantum point contacts, and Maxwell’s demons. Published by the American Physical Society 2024