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Accurate Rayleigh and Raman scattering cross sections, tensor components, depolarization ratios, and reversal coefficients for all rovibrational transitions within the X 1 Σ g + ground electronic state of H2 have been calculated. Raman spectra have been generated using these data. A method for calculating Raman scattering cross sections is formulated that is valid below the ionization threshold and in the region containing resonances, which explicitly accounts for all bound and dissociative vibrational levels of the bound intermediate electronic states and approximately accounts for the ionization continuum. A representative set of cross sections is presented for incident photon energies below 15 eV and compared with existing results in the literature where possible. Convergence of our results with an increasing number of bound intermediate electronic states is demonstrated. The accuracy of the Placzek–Teller approximation is discussed. The effect of accounting for the intermediate ionization continuum is investigated. Local thermal equilibrium cross sections are calculated for Rayleigh and Raman scattering. This work represents the most accurate and complete treatment of Raman scattering for molecular hydrogen to date. A total of 9582 Rayleigh and Raman scattering cross sections have been generated and are openly available on Zenodo under an open-source Creative Commons Attribution license at https://zenodo.org/doi/10.5281/zenodo.13441471. [ABSTRACT FROM AUTHOR]

Point defects are thermodynamically stabilized in all crystalline materials, with increased densities negatively impacting the properties and performance of transition metal dichalcogenides (TMDs). While recent point defect reduction methods have led to considerable improvements in the optoelectronic properties of TMDs, there is a clear need for theoretical work to establish the lower limit of defect densities, as represented by thermal equilibrium. To that end, an ab initio and thermodynamic analysis of the equilibrium densities of intrinsic point defects in MoSe2 and WSe2 is presented. The intrinsic defect formation energies at the limits of the selenium and metal-rich regimes are determined by density functional theory (DFT) and then augmented with elemental chemical potential functions to determine temperature- and pressure-dependent formation energies. Equilibrium defect densities are determined for MSe, SeM, vM, and vSe, where M and v, respectively, represent the metal and the vacancy, as a function of synthesis temperature and pressure. The effects of vibrational free energy contributions and treatment of the DFT exchange–correlation potential are found to be non-negligible. Calculated equilibrium densities are several orders of magnitude below reported defect densities in TMDs made by chemical vapor deposition, chemical vapor transport, and flux methods, thereby establishing that current synthesis methods are either kinetically limited or impurity dominated. [ABSTRACT FROM AUTHOR]

Monte Carlo simulations are widely employed to measure the physical properties of glass-forming liquids in thermal equilibrium. Combined with local Monte Carlo moves, the Metropolis algorithm can also be used to simulate the relaxation dynamics, thus offering an efficient alternative to molecular dynamics. Monte Carlo simulations are, however, more versatile because carefully designed Monte Carlo algorithms can more efficiently sample the rugged free energy landscape characteristic of glassy systems. After a brief overview of Monte Carlo studies of glass-formers, we define and implement a series of Monte Carlo algorithms in a three-dimensional model of polydisperse hard spheres. We show that the standard local Metropolis algorithm is the slowest and that implementing collective moves or breaking detailed balance enhances the efficiency of the Monte Carlo sampling. We use time correlation functions to provide a microscopic interpretation of these observations. Seventy years after its invention, the Monte Carlo method remains the most efficient and versatile tool to compute low-temperature properties in supercooled liquids. [ABSTRACT FROM AUTHOR]

In past decades, enormous effort has been expended to develop algorithms and even to construct special-purpose computers in order to efficiently evaluate total energies and forces for long-range-interacting particle systems, with the particle-mesh Ewald and the fast multipole methods as well as the "Anton" series of supercomputers serving as examples for biomolecular simulations. Cutoffs in the range of the interaction have also been used for large systems. All these methods require extrapolations. Within Markov-chain Monte Carlo, in thermal equilibrium, the Boltzmann distribution can, however, be sampled natively without evaluating the total energy. Using as an example the Lennard-Jones interaction, we review past attempts in this direction and then discuss in detail the class of cell-veto algorithms that allow for the fast, native sampling of the Boltzmann distribution without any approximation, extrapolation, or cutoff even for the slowly decaying Coulomb interaction. The computing effort per move remains constant with increasing system size, as we show explicitly. We provide worked-out illustrations and pseudocode representations of the discussed algorithms. Python scripts are made available in an associated open-source software repository. [ABSTRACT FROM AUTHOR]

In this contribution, we investigate the formation and dissociation of boron–hydrogen (BH) pairs in crystalline silicon under thermal equilibrium conditions. Our samples span doping concentrations of nearly two orders of magnitude and are passivated with a layer stack consisting of thin aluminum oxide and hydrogen-rich silicon nitride (Al 2 O 3 /SiN x :H). This layer stack acts as a hydrogen source during a following rapid thermal annealing. We characterize the samples using low-temperature Fourier-transform infrared spectroscopy and four-point-probe resistivity measurements. Our findings show that the proportion of hydrogen atoms initially bound to boron (BH pairs) rises with increasing boron concentration. Upon isothermal dark annealing at (163 ± 2) °C, hydrogen present in molecular form, H 2 , dissociates at a rate directly proportional to the concentration of boron atoms, ∝ [ B − ], leading to the formation of BH pairs. With prolonged annealing, an unknown hydrogen complex is formed at a rate that is inversely proportional to the square of the boron concentration, ∝ 1/[B − ] 2 , resulting in the disappearance of BH pairs. Based on experimental observations, we derive a kinetic model in which we describe the formation of the unknown complex through neutral hydrogen H 0 binding to a sink. Additionally, we investigate the temperature dependence of the reaction rates and find that the H 2 dissociation process has an activation energy of (1.11 ± 0.05) eV, which is in close agreement with theoretical predictions. [ABSTRACT FROM AUTHOR]

Recent studies including our own report (I) have revealed that heavily phosphorus (P) doped Czochralski-silicon (HP-Cz-Si) exhibits peculiar defect behaviors during crystal growth. HP-Cz-Si crystals with a low resistivity of around 0.6 mΩ cm (P concentration of 1.3 × 1020 P cm−3) have interstitial-type stacking faults (SFs) and dislocations, which degrade device characteristics. The purpose of this paper is to clarify what causes the defect behavior in HP-Cz-Si through theoretical calculations. The thermal equilibrium concentrations of substitutional P (Ps), interstitial P (Pi), and (Ps)n-vacancy (V) clusters (n = 1−4) were determined by using density functional theory (DFT) calculations. The concentrations of Pi ([Pi]) and (Ps)nV ([(Ps)nV]) balanced with the given Ps concentration ([Ps]) were obtained as a function of the total P concentration ([P]) and the temperature. On the basis of the calculated results those can quantitatively explain our experimental results in the report (I), we propose a defect model that accurately represents HP-Cz-Si crystal growth. The main feature of the model is that the incorporated Pi atoms at the solid/liquid interface around [Pi] = 1017 Pi cm−3 cause the formation of SFs and dislocations during the HP-Cz-Si crystal growth with around [P] = 1020 P cm−3. Furthermore, DFT calculations were performed for Pi segregation on the SF and for the photoelectron spectra of P 1s measured by hard x-ray photoelectron spectroscopy to explain the other experimental results in the report (I). [ABSTRACT FROM AUTHOR]

We report the two-photon absorption laser-induced fluorescence rotational spectrum of the CO B 1Σ+ ← X 1Σ+ Hopfield–Birge system (v′ = 0, v″ = 0) Q-branch in an ∼4850 K, atmospheric pressure plasma torch plume at thermal equilibrium in both the quenching-dominated (low laser intensity) and photoionization-dominated (high laser intensity) regimes. We provide a detailed analysis of the photophysics in these two regimes using a rate equation approach and propose modeling considerations for them as well. In the experimental spectra, distinct rotational transitions up to J″ = 83 are observed, allowing analysis over a very large range of rotational states. Evidence of predissociation is observed for J′ ≥ 64 and is likely due to the interaction with the D′1Σ+ electronic state, which has been proposed in the literature but never observed in the v′ = 0 state. The line positions of higher rotational states show disagreement with line positions calculated from molecular constants in the available literature, suggesting the need for modifications to the constants, which are reported here. A shift in the B 1Σ+ ← X 1Σ+ absorption spectrum toward higher two-photon energy as a result of the second-order Stark shift was observed in the photoionization-dominated spectrum, and the second-order Stark shift cross section was estimated to be 7 ± 3 × 10−18 cm2. The mean photoionization cross section of the excited upper state was inferred by comparing the line broadening of the two spectra and was estimated to be 11 ± 7 × 10−18 cm2. In addition, weak J′-dependent variations of the photoionization cross section were observed and are reported here. [ABSTRACT FROM AUTHOR]

Several types of dynamics at stationarity can be described in terms of a Markov jump process among a finite number N of representative sites. Before dealing with the dynamical aspects, one basic problem consists in expressing the a priori steady-state occupation probabilities of the sites. In particular, one wishes to go beyond the mere black-box computational tools and find expressions in which the jump rate constants appear explicitly, therefore allowing for a potential design/control of the network. For strongly connected networks admitting a unique stationary state with all sites populated, here we express the occupation probabilities in terms of a formula that involves powers of the transition rate matrix up to order N − 1. We also provide an expression of the derivatives with respect to the jump rate constants, possibly useful in sensitivity analysis frameworks. Although we refer to dynamics in (bio)chemical networks at thermal equilibrium or under nonequilibrium steady-state conditions, the results are valid for any Markov jump process under the same assumptions. [ABSTRACT FROM AUTHOR]

The effects of carbon in heavily phosphorus-doped Czochralski (HP-Cz) silicon (Si) substrates, with the concentrations across an order of magnitude from 1016 to 1017 cm−3, on the out-diffusion of phosphorus impurities within n/n+ epitaxial Si (Epi-Si) wafers have been investigated. It is found that the increase in the carbon concentration ([C]) from 1.0 × 1016 to 1.0 × 1017 cm−3 leads to the enhanced phosphorus out-diffusion within the n/n+ Epi-Si wafer when subjected to anneal at 1100 °C in an N2 or an O2 ambient or to anneal at 1150 °C in an N2 ambient, but hardly affects the phosphorus out-diffusion within the n/n+ Epi-Si wafer when subjected to anneal at 1150 °C in an O2 ambient. Based on the density functional theory calculations, it is derived that the increase in the [C] from 1.0 × 1016 to 1.0 × 1017 cm−3 in the HP-Cz Si substrate results in a significantly increased thermal equilibrium concentration of self-interstitial silicon (SiI) atoms at 1100 or 1150 °C, which, in turn, leads to the increased concentration of the SiI atoms that out-diffuse from the substrate to the epitaxial layer because the SiI atoms diffuse extremely fast in Si. Such a carbon-induced increase in the concentration of SiI atoms is believed to be responsible for the aforementioned enhanced phosphorus out-diffusion, which is predominantly dictated by the interstitialcy mechanism. In the case of anneal in the O2 ambient at sufficiently high temperatures such as 1150 °C, a large number of excessive SiI atoms injected into the Epi-Si wafer substantially mask the carbon enhancement effect on the phosphorus out-diffusion. Of technological significance, it is deduced that the [C] should be not higher than 1.0 × 1016 cm−3 in the HP-Cz Si wafers as the substrates of n/n+ Epi-Si wafers used for power devices. [ABSTRACT FROM AUTHOR]

The photovoltaic signal is an important characteristic of photodetectors, including but not limited to those that are based on p–n or p–i–n photodiodes. In an open-circuit configuration, pulsed excitation of the detector with ultrafast (femto or nanosecond) pulses leads to a photovoltaic signal that decays slowly (micro-second time scale). If the physics in the detector is dominated by the recombination of the photo-excited charge carriers, one expects the signal to decay without changing its sign. However, some experiments using short-pulse excitation have found that photovoltaic signals can undergo a sign change as a function of time following excitation, with positive signals immediately following the excitation, turning to negative signals several microseconds later. Here, we study various physical effects (density, temperature, electrostriction, pressure, photostriction, and bandgap renormalization) and determine their effect on photovoltaic signals. If, following ultrafast excitation, the carrier density and temperature are increased, and during relaxation the system reaches a state sufficiently close to the quasi-thermal equilibrium in which the carrier density is still elevated, but smaller than the intrinsic thermal equilibrium density at the elevated temperature, then the signal can become negative. [ABSTRACT FROM AUTHOR]

Fcc‐TixAl1–xN (TiAlN) coatings synthesized via chemical vapor deposition (CVD) reduce cutting tool wear. Although CVD conditions reportedly influence coating quality, no quantitative guidelines are yet available. To quantitatively study the film‐forming mechanism of TiAlN CVD, the gas composition over the surface must be known. Therefore, we developed a gas‐phase elementary reaction model for TiAlN CVD derived from TiCl4/AlCl3/NH3. First, we constructed a novel thermodynamic dataset including molecules that contained both Ti and Al, and calculated the equilibrium composition. Thermal equilibrium calculations in the gas phase showed that the most stable species were AlCl3 and TiCl3 rather than TiCl4. An elementary reaction model was constructed based on the kinetics of the gas‐phase species that were generated. Kinetic analysis revealed that gas‐phase reactions were largely absent under our reactor conditions. The thermal equilibrium calculations indicated that TiCl4 may have given rise to TiCl3. Thus, other reaction pathways of TiCl4 to TiCl3 were explored. We calculated the reaction rate constants of 12 reactions of Ti species and added them to the model, which revealed that TiCl4 decomposed to TiCl3 via TiCl3NH2. Under our conditions, TiCl4 and TiCl3NH2 are the major Ti species and AlCl3 and AlCl2NH2 are the major Al species, which suggests that some of these species may form films. Unlike in the earlier reaction model, NH2 and H radicals were produced, which may have contributed to the surface reactions. For reactors with large Surface/Volume ratio of reactor, the effects of gas‐phase reactions should be considered. Our reaction model enables estimation of the partial pressures of reactor gas species and will therefore aid study of the TiAlN deposition mechanism. [ABSTRACT FROM AUTHOR]

Fcc‐TixAl1–xN (TiAlN) coatings synthesized via chemical vapor deposition (CVD) reduce cutting tool wear. Although CVD conditions reportedly influence coating quality, no quantitative guidelines are yet available. To quantitatively study the film‐forming mechanism of TiAlN CVD, the gas composition over the surface must be known. Therefore, we developed a gas‐phase elementary reaction model for TiAlN CVD derived from TiCl4/AlCl3/NH3. First, we constructed a novel thermodynamic dataset including molecules that contained both Ti and Al, and calculated the equilibrium composition. Thermal equilibrium calculations in the gas phase showed that the most stable species were AlCl3 and TiCl3 rather than TiCl4. An elementary reaction model was constructed based on the kinetics of the gas‐phase species that were generated. Kinetic analysis revealed that gas‐phase reactions were largely absent under our reactor conditions. The thermal equilibrium calculations indicated that TiCl4 may have given rise to TiCl3. Thus, other reaction pathways of TiCl4 to TiCl3 were explored. We calculated the reaction rate constants of 12 reactions of Ti species and added them to the model, which revealed that TiCl4 decomposed to TiCl3 via TiCl3NH2. Under our conditions, TiCl4 and TiCl3NH2 are the major Ti species and AlCl3 and AlCl2NH2 are the major Al species, which suggests that some of these species may form films. Unlike in the earlier reaction model, NH2 and H radicals were produced, which may have contributed to the surface reactions. For reactors with large Surface/Volume ratio of reactor, the effects of gas‐phase reactions should be considered. Our reaction model enables estimation of the partial pressures of reactor gas species and will therefore aid study of the TiAlN deposition mechanism. [ABSTRACT FROM AUTHOR]

Taking inspiration from F. Bloch’s seminal work (PRA 7, 2187 (1973)), we investigate the quantum many-body states of superfluid 4He, unveiling a novel characteristic in the system’s energy levels. Below the transition temperature, the thermally active low-energy levels exhibit a distinctive grouping behavior, with each level belonging exclusively to a single group. In a superflow state, the system establishes thermal equilibrium with its surroundings on a group-specific basis. Specifically, the levels within a chosen group, initially populated, undergo thermal redistribution, while the remaining groups of levels stay vacant due to absence of transitions between groups. The macroscopic properties of the system, such as its superflow velocity and thermal energy density, are statistically determined by the thermal distribution of the occupied group. Additionally, we infer that the thermal energy of a superflow has an unusual relationship with flow velocity, such that the larger the flow velocity, the smaller the thermal energy. This relationship is responsible for a range of intriguing phenomena, including the mechano-caloric effect and the fountain effect, which demonstrate a fundamental coupling between the thermal motion and hydrodynamic motion of the system. Furthermore, we present experimental evidence of a self-heating effect in 4He superflows, confirming that a 4He superflow carries significant thermal energy related to its velocity. [ABSTRACT FROM AUTHOR]

ABSTRACT αβT cells protect vertebrates against many diseases, optimizing surveillance using mechanical force to distinguish between pathophysiologic cellular alterations and normal self‐constituents. The multi‐subunit αβT‐cell receptor (TCR) operates outside of thermal equilibrium, harvesting energy via physical forces generated by T‐cell motility and actin‐myosin machinery. When a peptide‐bound major histocompatibility complex molecule (pMHC) on an antigen presenting cell is ligated, the αβTCR on the T cell leverages force to form a catch bond, prolonging bond lifetime, and enhancing antigen discrimination. Under load, the αβTCR undergoes reversible structural transitions involving partial unfolding of its clonotypic immunoglobulin‐like (Ig) domains and coupled rearrangements of associated CD3 subunits and structural elements. We postulate that transitions provide critical energy to initiate the signaling cascade via induction of αβTCR quaternary structural rearrangements, associated membrane perturbations, exposure of CD3 ITAMs to phosphorylation by non‐receptor tyrosine kinases, and phase separation of signaling molecules. Understanding force‐mediated signaling by the αβTCR clarifies long‐standing questions regarding αβTCR antigen recognition, specificity and affinity, providing a basis for continued investigation. Future directions include examining atomistic mechanisms of αβTCR signal initiation, performance quality, tissue compliance adaptability, and T‐cell memory fate. The mechanotransduction paradigm will foster improved rational design of T‐cell based vaccines, CAR‐Ts, and adoptive therapies. [ABSTRACT FROM AUTHOR]

In this paper, we present a comprehensive simulation framework developed in MATLAB called HEMSim (Highly Energetic Materials Simulator) for modeling ideal detonations based on the fundamental principles of the Chapman-Jouguet (CJ) theory. The code efficiently computes the properties of an ideal detonation at the CJ point under the assumption of chemical, mechanical and thermal equilibrium, as well as the values of the isentropic expansion, while also enabling a fit of the parameters of the well-established JWL equation of state. Our code employs advanced equations of state (IMP EXPP 6 or BKWC for gaseous products and Birch–Murnaghan with thermal expansion for condensed products) to accurately model the behavior of a multiphase mixture of products coming from an ideal detonation. To our knowledge, there are no freely available codes capable of performing these complex calculations. Our implementation hence provides a robust framework for the accurate determination of ideal detonation parameters. [ABSTRACT FROM AUTHOR]

Hydrogen is the most dominant atom in the universe and is considered the main component of baryonic matter. Thus far, the quantum features of the unbounded hydrogen atoms in the background of the universe and the possibility of emerging unique quantum effects, such as entanglement on the cosmological scale, have not been considered. In this work, we demonstrate that the dynamical expansion of the universe leads to the emergence of natural entanglement in the hyperfine structure of atomic hydrogen. Our findings reveal that there exists a critical age for the universe where hydrogen atoms naturally build up entanglement, resulting from the expansion of the universe. More precisely, when the universe reaches the age of about 2.5 × 1018 seconds (about 80 billion years old), the hyperfine structure entanglement in hydrogen atoms naturally takes off, demonstrating a peculiar quantum phenomenon known as entanglement sudden birth. This expansion-induced entanglement becomes maximum at about 3.6 × 1018 seconds (about 115 billion years), after the Big Bang. By analyzing the fate of seed atoms formed in the early universe, this study underscores the significance of unique quantum mechanical features, such as entanglement, on cosmological scales. The authors investigate quantum entanglement in the hyperfine structure of the neutral hydrogen atom in thermal equilibrium with the cosmological microwave background radiation. They demonstrate that when the universe is around 80 billion years old, neutral hydrogen atoms begin to form entangled states, displaying a phenomenon known as entanglement sudden birth. [ABSTRACT FROM AUTHOR]

Exploring novel molecular photoswitches plays a crucial role in the field of photo‐functional materials chemistry. In this study, we synthesized aza‐diarylethenes with benzothiophene‐S,S‐dioxide as a part of the hexatriene structure and investigated their photochromic properties. Unlike previously reported aza‐diarylethenes, which exhibit fast thermally reversible photochromism, the compounds synthesized here exhibited pseudo‐photochemically reversible photochromism. Due to their thermal stability, we successfully isolated the colored isomer. X‐ray crystallographic analysis revealed for the first time that the colored isomer adopts a closed‐ring structure with a bond between carbon and nitrogen atoms. Remarkably, these aza‐diarylethenes exhibited not only photochemical ring‐closing and ring‐opening reactions but also thermal ring‐closing and ring‐opening reactions, driven by a thermal equilibrium between the open‐ and closed‐ring isomers. This behavior, unprecedented for common diarylethenes, was elucidated through kinetic analysis, revealing an energy‐level diagram for the thermal equilibrium between these isomers. Furthermore, 1H NMR spectroscopy revealed that both photochemically and thermally generated closed‐ring isomers adopt the same molecular structure, which was well explained based on the reaction mechanism of photochemical and thermal ring‐closing reactions. These findings not only advance the field of aza‐diarylethenes but also inspire future research in the development of new photoswitches. [ABSTRACT FROM AUTHOR]

In this paper, we numerically study the evolution of a classical real scalar field in (1 + 1) dimensions with initial conditions describing thermal fluctuations around a metastable vacuum. We track false vacuum decay in real time and compare several observables to the predictions of the standard Euclidean formalism. We find agreement for the shape of the critical bubble and the exponential suppression of the decay rate. However, the decay rate prefactor is almost an order of magnitude lower than the predicted value. We argue that this signals a breakdown of thermal equilibrium during the bubble nucleation. In addition, the inefficient thermalization in the system biases the properties of the statistical ensemble and leads to further decrease of the decay rate with time. We substantiate our interpretation with a suite of stochastic field simulations with controlled thermalization time. By varying this time, we find that the predictions of the standard equilibrium formalism are recovered when it is sufficiently short. We propose an upper bound on the thermalization time that must be satisfied in order to ensure the applicability of the Euclidean rate calculation. We discuss that this bound is unavoidably violated in common single-field models, irrespective of the number of space–time dimensions, implying that deviations from equilibrium in these models cannot be neglected. In theories with multiple fields, the bound may or may not hold, depending on the setup details. We investigate one more signature of nonequilibrium dynamics — coherent oscillonic precursors to the critical bubble nucleation. We show that they get suppressed in the stochastic dynamical simulations when the thermalization time is reduced. [ABSTRACT FROM AUTHOR]

A topology optimization-based design method for liquid cooling garments (LCGs) is proposed, aiming to enhance the heat flow performance of LCG systems by optimizing the internal microchannel structures. The primary objective is to improve flow and heat transfer characteristics in high-temperature environments, ensuring efficient heat dissipation. To achieve this, a novel liquid cooling film replaces traditional fixed hose structures and integrates with a water-cooled heat exchanger, forming a modular system that facilitates rapid assembly. A variable-density topology optimization model is applied to refine the microchannel configurations, examining the effects of fluid domain volume fractions and multi-objective weighting factors. The findings indicate that as the volume fractions increase, the microchannel designs become finer, leading to improved heat dissipation efficiency and reduced pressure drop. Numerical simulations and experimental validations reveal that the topology-optimized (TO) model outperforms traditional designs (TRA and TRB) in terms of heat flow performance, as observed in studies on flow fields, pressure distributions, temperature profiles, and Nusselt numbers. Specifically, the TO model reduces the average temperature by 30.96% compared to TRA and the maximum temperature by 19.46% compared to TRB at a flow rate of 240 ml/min. At a voltage of 8 V and a flow rate of 700 ml/min, the TO-designed LCGs achieve a steady-state temperature of 24 °C, exhibiting superior performance under high-flow scenarios. The TO design also demonstrates faster thermal equilibrium and a reduced temperature gradient, contributing to enhanced wearer comfort. This research confirms the efficacy of topology optimization, offering a theoretical basis and practical framework for developing high-performance LCG systems. [ABSTRACT FROM AUTHOR]

As a therapeutic approach for cancer, hyperthermia involves selectively increasing the temperature of affected tissues while preserving adjacent healthy tissues. This study explores the efficacy of pristine and coated silver, copper, and gold nanostructures such as nanorods, nanospheres, and nanoellipsoids for hyperthermia. This study performed finite element analysis to assess the relative performance of pristine nanostructures and those covered with different coating thicknesses. The metallic nanostructures were enclosed within the spherical zone of malignant tissue of 500 nm size, and the ambient temperature of these nanostructures was increased to 42–46 °C. Thermal equilibrium was reached after 0.1 μs of heating in the treatment region. Compared to other geometries, the nanorods quickly attained the required temperature in the treatment region. The nanorods with 1 nm coating thickness showed a fast heating response compared to 2 and 3 nm coatings. Silver, gold, and copper nanorods reached a temperature of 44.2, 43.6, and 43.5 °C, respectively, after 0.1 μs of heating. Gold-coated silver nanorods were discovered to be most efficient at achieving the highest temperature of 44.2 °C. [ABSTRACT FROM AUTHOR]

We study two harmonic oscillators with high quality factors, driven by equilibrium and off equilibrium thermal noise, the latter mimicked by establishing a temperature gradient. The two oscillators are coupled via a third reciprocal harmonic interaction. We deepen the case of a weak coupling between the two oscillators, and show the emergence of a "spike" in the displacement variance of the colder oscillator, when the respective elastic constants approach each other. Away from the peak, the displacement variance of each oscillator only reflects the value of the local temperature. We name this phenomenon the variance resonance, or alternatively covariance resonance, in the sense that it comes about as one element of the covariance matrix describing both oscillators. In fact, all of the elements of the covariance matrix show some distinctive behavior. The oscillator at the lower temperature, therefore, oscillates as if driven by a higher temperature, resonating with the other one. By converse, the variance of the hotter oscillator develops a deep dent, or depression, around the same region. We could not reproduce this behavior if either the coupling constant is not small compared to those of the two oscillators, or if the quality factors are not large enough. In fact, in such instances the system tends to resemble one which is in equilibrium at the average temperature, regardless of the relative strengths of the elastic constants of the two oscillators. Our results could have various applications including for example precision measurement systems, when not all parts of the apparatuses are at the same temperature. [ABSTRACT FROM AUTHOR]

Quantum heat engines (QHEs) are established by applying the principles of quantum thermodynamics to small−scale systems, which leverage quantum effects to gain certain advantages. In this study, we investigate the quantum Otto cycle by employing the dipole−dipole coupled polar molecules as the working substance of QHE. Here, the molecules are considered to be trapped within an optical lattice and located in an external electric field. We analyze the work output and the efficiency of the quantum Otto heat engine (QOHE) as a function of various physical parameters, including electric field strength, dipole−dipole interaction and temperatures of heat baths. It is found that by adjusting these physical parameters the performance of the QOHE can be optimized effectively. Moreover, we also examine the influences of the entanglement and relative entropy of coherence for the polar molecules in thermal equilibrium states on the QOHE. Our results demonstrate the potential of polar molecules in achieving QHEs. [ABSTRACT FROM AUTHOR]

Heat exchanger research is mainly exploited to develop and optimize new engineering systems with high thermal efficiency. Passive methods based on nanofluids, fins, wavy walls, and the porous medium are the most attractive ways to achieve this goal. This investigation focuses on heat transfer and entropy production in a nanofluid laminar flow inside a plate corrugated channel (PCC). The channel geometry comprises three sections, partially filled with a porous layer located at the intermediate corrugate channel section. The physical modeling is based on the laminar, two‐dimensional Darcy–Brinkman–Forchheimer formulation for nanofluid flow and the local thermal equilibrium model for the heat equation, including the viscous dissipation term. Numerical solutions were obtained using ANSYS Fluent software based on the finite volume technique and the appropriate meshed geometries. The numerical results are validated with theoretical, numerical, and experimental studies. The simulations are performed for CuO–water nanofluid and AISI 304 porous medium. The coupled effects of porous layer thickness (δ), Reynolds number (Re), and nanoparticle fraction (φ) on velocity, streamlines, isotherm contours, Nusselt number (Nu), and entropy generation (S) are analyzed and illustrated. The simulation results demonstrate that heat transfer enhancement in clear PCC can be achieved using a porous layer insert. For the porous thickness range of [0.1–0.6], the corresponding range of average Nusselt number increase is [35.7%–176.9%], and the average entropy generation is [105.4%–771.9%]. The effect of the Reynolds number is more important in a porous duct than in a clear one. For δ = 0.4 and φ = 5%, the increase of Re in the range of [200–500] induces an increase in average Nusselt number in the range of [80.9%–108.4%] and average entropy in [222.9%–309.1%] comparatively to clear PCC. The effect of φ is practically the same for porous and clear channels. For φ = 5%, the increase on average Nu is about 9%, and entropy generation is 5%. Accordingly, important improvements in heat transfer in PCC can be achieved through the combined effect of flow Reynolds number and porous layer thickness. [ABSTRACT FROM AUTHOR]

The onset of convection in a horizontal porous layer with chemical reaction and local thermal nonequilibrium is investigated. The nondimensional governing equations have been solved using the normal mode technique, which results in an eigenvalue problem. The analytical expressions for both stationary and oscillatory Rayleigh numbers are obtained. The effect of different parameters has been investigated and presented. The amplitude equation is derived using weakly nonlinear theory. Nusselt number is calculated using an amplitude equation to investigate heat transport. When modeling a fluid‐saturated porous medium, previous research on double‐diffusive convection has uniformly operated under the assumption of local thermal equilibrium (LTE) between the fluid and solid phases at all points within the medium. This standard practice assumes a minimal temperature gradient between the phases at any given location. However, in practical scenarios involving high‐speed flows or significant temperature differentials between the fluid and solid phases, the LTE assumption proves insufficient. [ABSTRACT FROM AUTHOR]

The temperature field variation of overhead conductors in the operating environment of the Qinghai-Tibet Plateau is significant, causing the stress on the conductor wires to fluctuate with climate changes, leading to fatigue and wire breakage. Conducting numerical simulation and analysis of the temperature field of overhead conductors in this environment is crucial for enhancing the safety of transmission lines. This paper establishes a numerical algorithm for solving the radial temperature distribution of overhead conductors in operation based on the two-dimensional steady-state heat balance theory. This method is applied to the numerical simulation of the temperature field of the heat-resistant aluminum alloy conductor NRLH58GJ630-55 in the Qinghai-Tibet Plateau environment, analyzing the effects of current load, wind speed, and ambient temperature on the radial temperature distribution of the overhead conductor. [ABSTRACT FROM AUTHOR]

In this paper, the aerodynamic performances including shock wave standoff distance (SSD) and heat flux of ELECTRE vehicle at 53.3 km and 4230 m/s for several types of numerical models are investigated. The numerical models include thermal equilibrium/nonequilibrium (1T/2T) assumption, three surface boundary conditions (no-slip/non-catalytic, slip/non-catalytic, slip/fully-catalytic), four chemical kinetic models (DK, Park, Gupta, and No Reaction (NR)) and two controlling temperatures (Ttr0.7Tve0.3, Ttr0.5Tve0.5). The results show that the chemical kinetic model significantly affects the SSD, and its value gradually decreases with the increase in chemical reaction rate. The SSD predicted by the NR model is 20.7% larger than that of the Park model. The SSD is also affected by the proportion of vibro-electronic temperature (Tve) in the controlling temperature, and the higher the proportion, the larger the SSD. Regarding the heat flux, the catalytic surface setting is crucial, where the value predicted by the fully-catalytic model is 62.2% higher than that by the non-catalytic model. As the chemical reaction rate of Gupta, DK, and Park models increases sequentially, the calculated heat flux decreases in turn. The heat flux predicted by the 2T model is lower than that by the 1T model, and the higher Tve proportion in the controlling temperature, the smaller the heat flux. The fundamental reason is that the trans-rotational convective heat flux of the 2T model is much lower than that of the 1T model, and the trans-rotational convective heat flux decreases with an increase in the Tve proportion. [ABSTRACT FROM AUTHOR]

For relaxor-ferroelectrics and relaxor-ferromagnets, the initial Ehrenfest-classification gives no phase-transition that contradicts the measured order-parameter, while the classification according to order-parameter and its derivatives raises the question about the relationships between the phase-transition and the specific-heat peak above and near the transition temperature. Here, based on the free-energy (F) of the thermodynamic limit systems when the external-field (h) tends 0, thermal equilibrium phase-transitions of thermodynamic limit systems with temperature (T) are reclassified into: (1) Discontinuous phase-transition. and have discontinuities in a T range; (2) Continuous phase-transition. and are continuous with T, while and have discontinuities at a T point; and (3) Diffuse phase-transition. and are continuous with T, while they are respectively equal to 0 at the transition-temperature (Td) and diffuse-temperature (Ts). The diffuse-region of the phase-transition is and the diffuse-degree , naturally giving the relation of the phase-transition to the specific-heat peak. [ABSTRACT FROM AUTHOR]

ABSTRACT To accurately characterize the heat dissipation behavior of LF6 aluminum alloy laser arc composite welded joint under low cycle fatigue, two fatigue life prediction methods based on dissipated energy were proposed. The experimental investigation has revealed four stages in the evolution of surface temperature increment, including initial temperature increase, subsequent decline, attainment of thermal equilibrium, and sudden temperature escalation leading to failure. Based on the energy dissipation method, two models predicting lifespan of welded joints have been formulated. Model I incorporates the effects of stress amplitude and mean stress, on lifetime demonstrating a strong linear correlation particularly under high‐stress level according to experimental comparisons. Model II introduces a relationship between plastic strain amplitude and inherent dissipated energy to assess fatigue life of welded joints. Digital imaging correction technique has been utilized to quantify plastic strain amplitude. The predicted results from Model II agree well with experimental data. [ABSTRACT FROM AUTHOR]

This study investigated the piezoelectric properties of BaTiO3 ceramics with different sizes through molecular dynamics simulations. The results show that all samples reached thermal equilibrium at 300 K and equilibrium in potential energy within 10 ns, confirming effective equilibration. As the size of the ceramics increased, the mean square displacement and diffusion coefficients decreased from 0.217 and 0.0034 to 0.1934 Å2 and 0.003 Å2/ns, attributed to a more uniform microstructure with fewer defects, resulting in reduced ion mobility. Furthermore, saturation polarization, residual polarization, and coercive field values increased from 0.35, 0.1, and 0.175 to 0.42 C/m2, 0.16 C/m2, and 0.282 MV/m, respectively, with increasing sample size, highlighting enhanced polarization responses due to a greater volume of ferroelectric material. Larger barium titanate (BaTiO3) crystals can have better polarization due to more domains aligning, but they may not deform as much (lower strain) because the walls among those domains can't move freely. While improved domain alignment contributed to higher polarization, the increased stress can restrict the mobility of the domain walls. These findings provided valuable insights into the size-dependent behavior of BaTiO3 ceramics, essential for optimizing their applications in electronic devices and sensors. The study underscored the importance of understanding microstructural effects on material properties for future advancements in ferroelectric technology. [ABSTRACT FROM AUTHOR]

We consider heat transport within a discontinuous domain by relying on the modeling approach proposed by Baioni et al. Such approach has been specifically designed to address diffusive processes in media with discontinuous physical properties and generalized boundary conditions at the discontinuities. Three algorithms are here applied to estimate the conductive heat transport in a bimaterial medium. The algorithms undergo testing using two test cases that share the same computational domain but differ in terms of their initial conditions. According to the numerical results all the algorithms ensure the conservation of thermal energy and preserve thermal equilibrium under steady state conditions. The Generalized Uffink Method (GUM) and Generalized HYMLA demonstrate sensitivity to the choice of the time step, whereas the Generalized Skew Brownian Motion appears to be unaffected by the value of Δ t . The GUM algorithm presents an optimal trade-off between accuracy and computational time. [ABSTRACT FROM AUTHOR]

We study the issue of temperature in a steady system around a black hole event horizon, contrasting it with the appearance of divergence in a thermal equilibrium system. We focus on a spherically symmetric system governed by general relativity, particularly examining the steady state with radial heat conduction. Employing an appropriate approximation, we derive exact solutions that illuminate the behaviors of number density, local temperature, and heat in the proximity of a black hole. We demonstrate that a carefully regulated heat inflow can maintain finite local temperatures at the black hole event horizon, even without considering the back-reaction of matter. This discovery challenges conventional expectations that the local temperature near the event horizon diverges in scenarios of thermal equilibrium. This implications shows that there's an intricate connection between heat and gravity in the realm of black hole thermodynamics. [ABSTRACT FROM AUTHOR]

The relationship between the thermodynamic and computational properties of physical systems has been a major theoretical interest since at least the 19th century. It has also become of increasing practical importance over the last half-century as the energetic cost of digital devices has exploded. Importantly, real-world computers obey multiple physical constraints on how they work, which affects their thermodynamic properties. Moreover, many of these constraints apply to both naturally occurring computers, like brains or Eukaryotic cells, and digital systems. Most obviously, all such systems must finish their computation quickly, using as few degrees of freedom as possible. This means that they operate far from thermal equilibrium. Furthermore, manycomputers, both digital and biological, are modular, hierarchical systems with strong constraints on the connectivity among their subsystems. Yet another example is that to simplify their design, digital computers are required to be periodic processes governed by a global clock. None of these constraints were considered in 20th-century analyses of the thermodynamics of computation. The new field of stochastic thermodynamics provides formal tools for analyzing systems subject to all of these constraints. We argue here that these tools may help us understand at a far deeper level just how the fundamental thermodynamic properties of physical systems are related to the computation they perform. [ABSTRACT FROM AUTHOR]

This work proposes an extended version of the quantum-kinetic chemistry models, aiming to accurately reproduce experimental measurements and high-fidelity calculations in both thermal equilibrium and non-equilibrium. The extension involves the development of new formulations, incorporating a set of tunable parameters obtained from a non-linear least squares fit on the dataset. The newly derived analytical expressions are implemented in a direct simulation Monte Carlo (DSMC) solver. These formulations are applied to the 19 most representative chemical reactions of an air mixture involving dissociation and exchange reactions. The DSMC reaction rates demonstrate excellent agreement with the newly derived analytical expressions, providing verification of the successful implementation in the DSMC solver. The study demonstrates excellent reproduction of the baseline dataset for both thermal equilibrium and non-equilibrium. Furthermore, the new formulations are applied to simulate the surface heat flux during the second space transport system (STS-II) mission at an altitude of 92.35 km. [ABSTRACT FROM AUTHOR]

Most engineering tools dealing with detonation waves in condensed explosives are based on the reactive Euler equations, which involve a thermodynamic closure based on temperature and pressure equilibrium conditions. Indeed, the reactant and the detonation products are assumed to evolve in mechanical and thermal equilibrium. Although the assumption of thermal equilibrium is physically questionable, the reactive Euler equations are used for convenience. This choice is supported by several reasons. When considering thermal equilibrium, the assessment of thermal exchanges between the reactant and the detonation products is simplified, as no exchange coefficient needs to be determined. Furthermore, the reactive Euler equations are in conservative form and the shock relations are well-defined. This model appears to be the simplest option for addressing detonations in condensed explosives. However, this simplicity has limitations and conceals a subtle difficulty that can lead to pathological detonations. The present contribution investigates this difficulty and presents a global exothermic condition to preserve exothermic detonations in the frame of temperature–pressure equilibrium flow models. This condition depends on the equations of state only. It is independent of the kinetics used to model the decomposition of the explosive. By meticulously selecting the thermodynamic parameters of the equations of state for the reactant and detonation products, pathological detonations are prevented, thereby maintaining a globally exothermic reaction consistent with the Zeldovich–von Neumann–Döring theory. [ABSTRACT FROM AUTHOR]

A numerical bifurcation analysis is presented for an industrial application where direct resistance heating through a DC is applied to a flat metallic plate, which is cooled by a turbulent boundary layer and radiation. The process is modeled with a conjugate heat transfer between the plate and the cooling air steam. The convective part of the heat transfer mechanism is formulated in the framework of an integral approach, considering a turbulent core based on power law velocity and temperature profiles and a thin laminar sublayer thermally coupled with axial conduction along the plate. The analysis reveals that the problem admits two solutions: one stable and one unstable, separated by a limit point. The existence of multiple solutions is a consequence of the nonlinear electric resistivity–temperature relationship, allowing thermal equilibrium between heat generation and heat dissipation in multiple points. The application of realistic boundary conditions at the wall–fluid interface shows that the thermal to the hydrodynamic boundary layer thicknesses ratio along the plate is no longer close to the value of 1.25, as it is the case with a constant wall temperature. Instead, significant deviations occur due to the thermal coupling between the wall and the cooling fluid. The multiplicity structure and, consequently, the limit points depend on the plate Reynolds number and on the conduction–convection parameter. The locus of the limit points defines an instability threshold beyond which any excess applied current will trigger a thermal runaway phenomenon. This is also an equivalent of the maximum current carrying capacity of the plate. [ABSTRACT FROM AUTHOR]

Droplet manipulation is a multidisciplinary field with broad applications across various industries. It holds significant potential in areas such as microfluidics, oil–water separation, water harvesting, and heat transfer. However, there is still a lack of comprehensive knowledge regarding droplet migration on restricted surfaces. In this study, we conducted a numerical simulation using the front-tracking method to investigate the heat transfer associated with droplet migration on a cold plate with a wettability gradient. We examined the effects of relative temperature differences, surface wettability, low initial impact velocities (W e ≤ 10), and wettability constraints (the width of the wettability stripe capable of driving droplet movement) on various droplet-related heat transfer characteristics and the resulting temperature field distribution. Our key findings indicate that as the temperature difference between the droplet and the surface increases, the heat flux experienced by the droplet after deposition also increases. Additionally, the decline in the heat flux curve during the descending phase becomes more significant. The surface contact angle plays a crucial role in the heat transfer dynamics during droplet migration. Droplets reach thermal equilibrium more quickly on hydrophilic surfaces with smaller contact angles. Higher initial impact velocities initially cause droplets to rebound on the surface, leading to more pronounced fluctuations in transient heat flux during the impact phase. However, as droplets transition from the rebound phase to the migration phase, the impact velocity's influence diminishes. Additionally, the restricted wettability ( W * ) affects the droplet-surface heat transfer through variations in the wetting area. We observed a fourfold difference in the relative wetting area between W * = 0. 4 and W * = 2. 5 in the final stage. [ABSTRACT FROM AUTHOR]

This review delves into the pivotal primordial stage of the universe, a period that holds the key to understanding its current state. To fully grasp this epoch, it is essential to consider three fundamental domains of physics: gravity, particle physics, and thermodynamics. The thermal history of the universe recreates the extreme high-energy conditions that are critical for exploring the unification of the fundamental forces, making it a natural laboratory for high-energy physics. This thermal history also offers valuable insights into how the laws of thermodynamics have governed the evolution of the universe's constituents, shaping them into the forms we observe today. Focusing on the Standard Cosmological Model (SCM) and the Standard Model of Particles (SM), this paper provides an in-depth analysis of thermodynamics in the primordial universe. The structure of the study includes an introduction to the SCM and its strong ties to thermodynamic principles. It then explores equilibrium thermodynamics in the context of the expanding universe, followed by a detailed analysis of out-of-equilibrium phenomena that were pivotal in shaping key events during the early stages of the universe's evolution. [ABSTRACT FROM AUTHOR]

Owing to a lack of methodology for rationally and selectively synthesizing twisted nanographenes, it is usually inevitable that we obtain nanographenes as a mixture with various geometries, such as unidirectionally twisted, alternatively twisted, randomly twisted, and even wavy structures, reflecting the high activation barriers among them. Otherwise, they are interconvertible if the barriers are low enough such that only averaged properties can be observed under a thermal equilibrium. Recently, we reported on a double-twisted nanographene containing four [6]helicene units within the skeleton. In this paper, we discuss the robust conformational stability of the nanographene, both experimentally and computationally. The results indicate that the nanographene could only be racemized at temperatures exceeding 200 °C, and the first flip of one of the four [6]helicene units is the rate-degerming step. [ABSTRACT FROM AUTHOR]

The accurate flux calibration of observational data is vital for astrophysics and cosmology because absolute flux uncertainties of stellar standards propagate into scientific results. With the ever higher precision achieved by telescopic missions (e.g. JWST) in the infrared (IR), suitable calibrators are required for this regime. The basis of the Hubble Space Telescope (HST) flux scale is defined by model fits of three hot (⁠|${T_\mathrm{eff}} > 30\, 000$|  K) hydrogen-atmosphere (DA) white dwarfs, which achieve an accuracy better than 1 per cent at optical wavelengths but falls below this level in the IR range. We present a network of 17 cooler DA white dwarfs with |${T_\mathrm{eff}} < 20\, 000$|  K as spectrophotometric flux standards that are equally, if not more, accurate at IR wavelengths. Cooler white dwarfs do not suffer from non-local thermal equilibrium effects in continuum flux or from ultraviolet metal line blanketing, have a larger sky density, are generally closer to Earth with little or negligible interstellar reddening, and have energy distributions peaking in the optical or near-IR. Using the latest grid of DA local thermal equilibrium atmosphere models with three-dimensional convection, the observed Space Telescope Imaging Spectrometer (STIS) and Wide Field Camera 3 (WFC3) fluxes of our network are accurate to 3 per cent over most of the range |$1450\!\! - \!\!16\, 000$|  Å, with a median standard deviation of 1.41 per cent. Fitting the HST STIS and WFC3 white dwarf spectral energy distributions (SEDs) and Balmer lines independently yields SEDs that agree within |$3\sigma$|⁠ , which demonstrates the precision of the models for our network. [ABSTRACT FROM AUTHOR]

The article discusses the use of Arduino in introductory thermal energy experiments, specifically focusing on thermal equilibrium. By utilizing Arduino Uno boards and DS18B20 temperature sensors, students can explore heat transfer between two objects at different temperatures. The experiment is suitable for high school or college students in nonmajor science courses and can be adapted for elementary or middle school students. The article emphasizes the advantages of using sensors in STEM education, making experiments engaging and accessible to all students, regardless of their prior knowledge or skills. [Extracted from the article]

The spatial distribution of the electrothermal field within molten salt electrolytic cells significantly influences the efficiency of the electrolysis process, the quality of the end products, and the overall stability of the system. Enhancing the design of chloride electrolysis cells can lead to marked improvements in both process efficiency and system stability, thereby yielding increased economic benefits. This study introduces a design for a chloride electrolysis cell and examines the thermal budget under elevated electrical current intensities across 16 electrode pairs. It further analyzes the degree to which various parameters affect thermal equilibrium. The findings indicate that the electrolytic cell maintains a small thermal budget discrepancy at a current intensity of 124 kA and is less than 5%, with substantial heat dissipation observed at the surface of the top area of anode exposure and considerable energy consumption at both the anode and the electrolyte. Dimensionless treatment of the different parameterized simulation results has been conducted to develop a nondimensional equation, describing the thermal equilibrium conditions within the electrolytic cell. This foundational work paves the way for further investigations into the interactions between the electrothermal field and other physical fields, as well as for the optimization of the electrolytic cell's geometry and design. [ABSTRACT FROM AUTHOR]

Electrical fires perennially rank first in fire occurrence types, with conductor overcurrent being one of the main inducements. This topic draws significant attention from scientific researchers and fire investigators. To understand the overcurrent fault and combustion characteristics of copper‐clad aluminum conductors, this paper examines 2.5 mm2 copper‐clad aluminum conductors that meet national standards, investigating morphological changes, temperature variations in the core and insulation layer, and flame propagation patterns under overcurrent conditions. Experiments using an electrical fault simulation device were conducted to study overcurrent failures of copper‐clad aluminum conductors under 52.5–105 A conditions. The results indicate that when the current exceeds 67.5 A, the conductor undergoes a series of changes during energization, including smoking, expanding, carbonizing, burning, and breaking; at 52.5 A, the insulation layer reaches thermal equilibrium at 150 s without combustion; for currents between 60–67.5 A, wire core temperature variations can be divided into three stages; at 75 A, the insulation layer reaches thermal equilibrium 10s before breaking; currents above 82.5 A see a sharp increase in temperature in both the core and insulation layer before the conductor breaks; above 97.5 A, the conductor first breaks and then burns. The research results have significant theoretical value in improving the scientific rigor of fire accident investigations and forensic evidence examinations. [ABSTRACT FROM AUTHOR]

Monolayer nanosheets of zirconium phosphate in aqueous suspension exhibit short-range repulsion and long-range attraction, producing, at overall volume fractions larger than about half a percent, phase separation into higher-concentration liquid crystal and lower-concentration isotropic regions. At high concentrations, this phase separation takes the form of an emulsion of condensed, liquid-crystalline droplets, which anneal to form lens-shaped tactoids. These tactoids provide an opportunity to study the liquid crystal ordering of inorganic nanosheets in the limit of large shape anisotropy (diameter/thickness~400) and high packing fraction (volume fraction ≳ 70%). The internal liquid crystal structure of the tactoids remains nematic even under conditions that would usually favor ordering into lamellar smectics. Local lamellar ordering is suggested by short-range, smectic-like layer correlations, but a full transition into a smectic phase appears to be inhibited by the nanosheet edges, which act as a perturbative population of dislocation loops in the system of layers. Under conditions of thermal equilibrium, the nanoplates organize positionally to enable bend deformation of the director, a hallmark of the nematic phase and its principal distinction from the smectic, where bend must be expelled. [ABSTRACT FROM AUTHOR]

Modeling environments that are not in local thermal equilibrium, such as protoplanetary disks or planetary atmospheres, with molecular spectroscopic data from space telescopes requires knowledge of the rate coefficients of rovibrationally inelastic molecular collisions. Here, we present such rate coefficients in a temperature range from 10 to 500 K for collisions of CO2 with He atoms in which CO2 is (de)excited in the bend mode. They are obtained from numerically exact coupled-channel (CC) calculations as well as from calculations with the less demanding coupled-states approximation (CSA) and the vibrational close-coupling rotational infinite-order sudden (VCC-IOS) method. All of the calculations are based on a newly calculated accurate ab initio four-dimensional CO2–He potential surface including the CO2 bend (ν2) mode. We find that the rovibrationally inelastic collision cross sections and rate coefficients from the CSA and VCC-IOS calculations agree to within 50% with the CC results at the rotational state-to-state level, except for the smaller ones and in the low energy resonance region, and to within 20% for the overall vibrational quenching rates except for temperatures below 50 K where resonances provide a substantial contribution. Our CC quenching rates agree with the most recent experimental data within the error bars. We also compared our results with data from Clary et al. calculated in the 1980s with the CSA [A. J. Banks and D. C. Clary, J. Chem. Phys. 86, 802 (1987)] and VCC-IOS [D. C. Clary, J. Chem. Phys. 78, 4915 (1983)] methods and a simple atom-atom model potential based on ab initio Hartree–Fock calculations and found that their cross sections agree fairly well with ours for collision energies above 500 cm−1, but that the inclusion of long range attractive dispersion interactions is crucial to obtain reliable cross sections at lower energies and rate coefficients at lower temperatures. [ABSTRACT FROM AUTHOR]

The thermal equilibrium of asphalt mixtures, when combined with reclaimed asphalt pavement (RAP), forms the foundation for high-quality hot pavement recycling. This study focuses on quantifying the thermal equilibrium process of recycled asphalt during mixing. To achieve this objective, a typical RAP content of 20% was utilized in preparing the recycled asphalt. In the experiments, three preheated RAP temperatures were considered to reflect different practical scenarios. Thermal images of recycled asphalt were captured throughout the entire mixing process from 10 s to 90 s in order to characterize the temperature evolution pattern of recycled asphalt mixtures. In addition to experiments, discrete element simulation was conducted to elucidate additional details regarding temperature exchange. The results indicated that the initial thermal equilibrium during mixing may have a significant impact on RAP dispersion and temperature variation, while the subsequent mixing period has limited influence on the final thermal state. Furthermore, it is observed that complete thermal equilibrium cannot be achieved due to the nonuniform distribution of RAP at the end of mixing. In addition, a model describing the temperature evolution of RAP is proposed in this study, which demonstrates a good fit with the data. [ABSTRACT FROM AUTHOR]

Phase equilibria in the ZrO2–YO1.5–NbO2.5 system were experimentally studied at 1300°C, and a comparison with the existing ZrO2–YO1.5–TaO2.5 (ZYTO) was conducted. Ternary fluorite phases on the Y:Nb > 1 side extend from binary ZrO2‐YO1.5 to YO1.5–NbO2.5 system, generating a continuous solid solution region. Furthermore, it was observed that three phases of M‐YNbO4, fluorite, and m‐ZrO2 were in equilibrium. On the Y:Nb < 1 side, two three‐phase equilibrium regions were measured, namely M‐YNbO4+m‐ZrO2+O‐Nb2Zr6O17 and h‐Nb2O5+O‐Nb2Zr6O17+M‐YNbO4. The tetragonal YNbO4 and ZrO2 phases both extend nearly along with Y:Nb = 1. The t‐ZrO2 phases with slightly lower stabilizer content were found to transform into their monoclinic polymorph during the cooling process. However, in the ZrO2–YNbO4 subsystem, the tetragonal ZrO2 was nontransformable due to larger YO1.5 and NbO2.5 co‐dopants, and the maximum solubility is about 18.1 mol%. Upon cooling, the tetragonal YNbO4 phase, even with the maximum ZrO2 content, is transformable to monoclinic form. The maximum solubility of ZrO2 in YNbO4 is determined to be about 20.7 mol%. Finally, the high‐temperature liquidus in the ZrO2–YNbO4 system was first determined based on the cooling traces, and a vertical section diagram was proposed for further speculation. A eutectic reaction of Liquid→YNbO4+ZrO2 was discovered, and the eutectic composition and temperature were measured as 39.2ZrO2–29.2YO1.5–31.6NbO2.5 and 1813°C. This study provides the basis for thermodynamic assessment of ZrO2–YO1.5–NbO2.5 and is valuable for the design and development of the ZrO2–YO1.5–NbO2.5‐based ceramic materials. [ABSTRACT FROM AUTHOR]