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Studying the macroscopic‐phenomenological behavior of amorphous polymers at glass transition is often subject to limitations because the ordinary differential equations that describe the material behavior require numerical solution. To avoid these limitations, ad‐hoc‐formulated models of the glass transition have been proposed. However, their scope of application is expected to be limited due to insufficient theoretical foundation. This work establishes a theoretical framework for models that use the logistic function to approximate the macroscopic‐phenomenological behavior of amorphous polymers at glass transition. For this purpose, an exactly‐solvable Riccati equation is derived within thermodynamics with internal state variables. A closed‐form expression in terms of mathematical functions for the temperature derivative of a single internal state variable is the result. This closed‐form expression contains the logistic function thus featuring a continuous transition region centered around a pressure and cooling‐rate dependent transition temperature. Based on comparison of existing models with the exact solution derived from the Riccati equation, generalized models that approximate the thermal expansion coefficient and heat capacity at glass transition are proposed. This work thus demonstrates the validity of the logistic function in glass transition models of amorphous polymers and provides suggestions as to how existing models can be extended in their applicability. [ABSTRACT FROM AUTHOR]

The chemical potential of a component in a solution is defined as the free energy change as the amount of that component changes. Computing this fundamental thermodynamic property from atomistic simulations is notoriously difficult because of the convergence issues involved in free energy methods and finite size effects. This Communication presents the so-called S0 method, which can be used to obtain chemical potentials from static structure factors computed from equilibrium molecular dynamics simulations under the isothermal–isobaric ensemble. This new method is demonstrated on the systems of binary Lennard-Jones particles, urea–water mixtures, a NaCl aqueous solution, and a high-pressure carbon–hydrogen mixture. [ABSTRACT FROM AUTHOR]

The high-pressure and high-temperature thermodynamic properties of rhodium (up to 2000 K and 300 GPa) are presented using the first principle approach within the quasi-harmonic approximation. The thermal Helmholtz free energy includes the contribution of both phonon vibrations and electronic excitations. The performance of three popular exchange-correlation functionals—local density approximation [Perdew et al., Phys. Rev. B 23, 5048 (1981)], Perdew–Burke–Ernzerhof generalized gradient approximation (PBE) [Perdew et al., Phys. Rev. Lett. 77, 3865 (1996)], PBE modified for dense solids [Perdew et al., Phys. Rev. Lett. 100, 136406 (2008)] are shown. The simulated thermal expansion coefficient, isobaric heat capacity, mode-Grüneisen parameter, thermodynamic average Grüneisen parameter, and bulk modulus are compared with the available experimental and theoretical reports. The contribution of thermal electronic excitations to the obtained thermodynamic parameters is significant at low pressure and high temperatures, except in bulk modulus, where it is small. The pressure-dependent elastic constant coefficient (Cij) and the Debye temperature are computed at 0 K. The Pugh ratio calculated from Cij indicates that rhodium undergoes brittle to ductile transitions at an average pressure of 7.45 GPa. [ABSTRACT FROM AUTHOR]

The entropy change that occurs upon mixing two fluids has remained an intriguing topic since the dawn of statistical mechanics. In this work, we generalize the grand-isobaric ensemble to mixtures and develop a Monte Carlo algorithm for the rapid determination of entropy in these systems. A key advantage of adiabatic ensembles is the direct connection they provide with entropy. Here, we show how the entropy of a binary mixture A–B can be readily obtained in the adiabatic grand-isobaric (μA, μB, P, R) ensemble, in which μA and μB denote the chemical potential of components A and B, respectively, P is the pressure, and R is the heat (Ray) function, that corresponds to the total energy of the system. This, in turn, allows for the evaluation of the entropy of mixing and the Gibbs free energy of mixing. We also demonstrate that our approach performs very well both on systems modeled with simple potentials and with complex many-body force fields. Finally, this approach provides a direct route to the determination of the thermodynamic properties of mixing and allows for the efficient detection of departures from ideal behavior in mixtures. [ABSTRACT FROM AUTHOR]

Densities of pure furan, toluene, 1-octanol, n-hexane and of binary liquid mixtures containing furan, have been measured from 303.15 to 383.15 K at pressures up to 1.6 MPa, using a vibrating tube densimeter. Excess molar volumes have been calculated from the densities with an average standard uncertainty 0.02 cm3⋅mol−1. Excess molar enthalpies of the binary mixtures were measured at temperatures ranging from 313.15 to 383.15 K at 0.5 MPa and/or 1.0 MPa, using flow mixing calorimeter. The average standard uncertainty on the whole measurements is less than 1%. The excess molar properties derived from experimental data were correlated using Redlich–Kister polynomial functions and NRTL activity coefficient model and Prigogine–Flory–Patterson modelling is described and used to correlate the data. [ABSTRACT FROM AUTHOR]

We present an experimental investigation of surface tension–driven sintering and associated densification of glassy rhyolitic ash and crystals under shallow volcanic conduit conditions. Rhyolitic glass (< 45 μm) and quartz were run in suites of hydrothermal experiments for 30 min to 9 h. Fluid pressure was isobaric ( P H 2 O = 40 M P a ) for all runs, and temperature was held constant at a value between 675 and 850 °C. Three size populations of quartz were used: 45–76 µm (fine), 90–125 µm (medium), and 250–500 µm (coarse). All samples evolved from loose, cohesion-less particles to a friable, agglutinated framework of glass with an interconnected network of pores of ≥ 15 vol.%. Samples sintered more slowly at cooler temperatures and with finer crystals relative to higher temperatures or coarser crystals. Compared with previous experiments on glass-only samples, all crystal-bearing samples reached a higher final porosity, and those containing fine and medium crystals also sintered more slowly. Permeability was determined via numerical simulation for one sample and was found to be similar to natural samples with equivalent porosity. Our results suggest that solid particles inhibit the sintering process by holding porous networks open. Sintered magma in the shallow conduit that contains crystal (and lithic) particles can thus experience more sustained degassing and outgassing than crystal-free systems. [ABSTRACT FROM AUTHOR]

A fundamental equation of state expressed explicitly in the Helmholtz energy is presented for R-1224yd(Z), an environmentally friendly refrigerant for centrifugal chillers, high-temperature heat pumps, and organic Rankine cycles. The equation of state is based on consistent experimental data for the critical parameters, vapor pressures, saturated liquid and vapor densities, (p , ρ , T) behavior, vapor-phase sound speeds, liquid-phase sound speeds, and ideal-gas isobaric heat capacities. The equation is valid at temperatures from the triple-point temperature (157.8 K) to 473 K and pressures up to 35 MPa. In the valid range, expected relative uncertainties ( k = 2 ) of the equation are 0.04 % for vapor pressures, 0.1 % for saturated liquid densities, 2 % for saturated vapor densities, 0.05 % for liquid densities, 0.3 % for vapor densities, 0.02 % for vapor-phase sound speeds, and 0.04 % for liquid-phase sound speeds, except in the critical region, where more significant uncertainties of up to 2 % are sometimes observed in densities. The equation exhibits reasonable behavior in the critical and extrapolated regions; this is demonstrated by several plots of derived properties over wide ranges of temperature and pressure. [ABSTRACT FROM AUTHOR]

The pressure-volume-temperature-entropy equations of state, P-V-T-S Eos, of polyethylene (PE) for its isothermal, isobaric, isochoric and isoentropic ensembles and the correlation between the P-V-T-S Eos in the various ensembles were reported in our previous reports. The three dimensional plane plot, 3D plane plot, for the various ensembles, such as the 3D (PV-V-SV) isochoric plane plot, and the three dimensional list point plot, 3D list point plot, for the ensemble, such as the 3D (PT, VT, ST) isothermal list point plot, were determined based on the P-V-T-S Eos of PE where the subscripts, T, P, V, and S meaning for the isothermal, isobaric, isochoric and isoentropic ensembles, respectively. In this paper a projection of the 3D list point plot on the 3D plane plot for an appropriate pair of the planes gave a new 3D plot where the list points in the 3D list point plot were found on the surface of the 3D plane plot. [ABSTRACT FROM AUTHOR]

Platinum-based chemotherapy is commonly used in the treatment of various cancers, including epithelial ovarian cancer (EOC). However, in EOC, chemotherapy failure is mainly caused by platinum resistance. In this present study, we aimed to identify novel biomarkers for predicting platinum chemosensitivity. Fresh specimens of 16 serous high-grade ovarian cancer (HGSC) cases were collected during cytoreductive surgery. Isobaric tags were used to identify differentially expressed proteins in platinum-resistant samples (n = 8) and platinum-sensitive samples (n = 8). Compared to platinum-sensitive samples, 741 significantly differentially expressed proteins were detected, of which 325 were upregulated and 416 were downregulated. To validate the isobaric tags for relative and absolute quantification (iTRAQ) method, western blotting was performed on two upregulated proteins, angiomotin-like protein 1 (AMOTL1) and Lumican. The results showed that platinum-resistant tumor samples expressed significantly higher levels of AMOTL1 and Lumican than platinum-sensitive tumor samples. Altogether, we identified candidate proteins related to platinum resistance in ovarian cancer. Both AMOTL1 and Lumican seem to be promising biomarkers that could distinguish between platinum-resistant and platinum-sensitive EOC. [ABSTRACT FROM AUTHOR]

Evolutionary crystal structure prediction searches have been employed to explore the ternary Li–F–H system at 300 GPa. Metastable phases were uncovered within the static lattice approximation, with LiF3H2, LiF2H, Li3F4H, LiF4H4, Li2F3H, and LiF3H lying within 50 meV/atom of the 0 K convex hull. All of these phases contain H n F n + 1 − (n = 1, 2) anions and Li+ cations. Other structural motifs such as LiF slabs, H 3 + molecules, and Fδ− ions are present in some of the low enthalpy Li–F–H structures. The bonding within the H n F n + 1 − molecules, which may be bent or linear, symmetric or asymmetric, is analyzed. The five phases closest to the hull are insulators, while LiF3H is metallic and predicted to have a vanishingly small superconducting critical temperature. Li3F4H is predicted to be stable at zero pressure. This study lays the foundation for future investigations of the role of temperature and anharmonicity on the stability and properties of compounds and alloys in the Li–F–H ternary system. [ABSTRACT FROM AUTHOR]

In this work, the isothermal vapor–liquid equilibrium (VLE) of trans-1,3,3,3-tetrafluoropropene (HFO-1234ze(E)) and 1,1,1,3,3-pentafluoropropane (HFC245fa) binary system, along with the saturated vapor pressures HFO-1234ze(E) and HFC-245fa, were measured by static-analytic apparatus. The VLE measurements of HFO-1234ze(E) + HFC-245fa binary system are performed at temperatures from (293.28 to 333.09) K, while the measurements for vapor pressures of HFO1234ze(E) and HFC-245fa were conducted in the temperature range of (263.08 to 363.01) K. The vapor pressures were correlated by the Peng-Robinson (PR) equation of state (EoS) associated with the Mathias-Copeman (MC) alpha function, and the VLE data were correlated to the PRMC-vdW model where the MC alpha function and the van der Waals (vdW) mixing rules were combined with the PR EoS. The experimental VLE data were compared with the predictive E-PPR78 model. The modeling results of the PRMC-vdW model had good agreement with the experimental VLE data, while the E-PPR78 model shows negative bias in the prediction of equilibrium pressures. The experimental VLE data were also compared with literature data for consistency checks. The two sets of VLE data were basically consistent, while a discrepancy was found when analyzing the relationship between binary interaction parameter kij and temperature. [ABSTRACT FROM AUTHOR]

The relevance of research into the thermophysical properties of lead is associated with the implementation of a BREST-300 reactor project. The enthalpy of solid and liquid lead in the range of 432–1327 K was measured by the mixing method using a massive isothermal calorimeter. The enthalpy of melting was determined. Approximation equations for the temperature dependence of enthalpy in the range of 298.15–1325 K were obtained to determine the isobaric heat capacity. The existence of a heat capacity minimum for liquid lead in the region of 830 K was established. An analysis of existing recommended and experimental data on the caloric properties of lead was performed. The need for new measurements of the enthalpy and heat capacity of a melt at temperatures above 1050 K is substantiated. [ABSTRACT FROM AUTHOR]

This work presents a fundamental equation of state for the thermodynamic properties of R-1336mzz(E). The equation of state is expressed explicitly in the Helmholtz energy with temperature and density as the independent variables, and is based on consistent experimental datasets, including the critical parameters, vapor pressure, saturated liquid and vapor densities, (p , ρ , T) behavior, vapor phase sound speed, and ideal-gas isobaric heat capacity. The equation of state is valid for temperatures from 200.15 K to 410 K and pressures up to 5.7 MPa. In this range, expected relative uncertainties at the 95 % confidence interval ( k = 2 ) are 0.1 % for vapor pressures, 1 % for saturated liquid densities, 1 % for saturated vapor densities, 0.15 % for liquid densities, 0.5 % for vapor densities, and 0.05 % for vapor phase sound speeds, except in the critical region where larger uncertainties of up to 2 % are sometimes observed in densities. The equation exhibits reasonable behavior in the critical and extrapolated regions; this is demonstrated by several plots of derived properties over wide ranges of temperature and pressure. Through the use of the new equation of state, this work also formulates an extended corresponding states (ECS) model for the viscosity and thermal conductivity of R-1336mzz(E) to represent recent experimental data for these properties mostly within their uncertainties. [ABSTRACT FROM AUTHOR]

A dual-capillary apparatus was developed for highly accurate measurements of density of liquids, including the supercooled liquid region. The device was used to determine the density of supercooled heavy water in the temperature range from 254 K to 298 K at pressures ranging from atmospheric to 100 MPa, relative to density at reference isotherm 298.15 K. The measurements of relative density were reproducible within 10 ppm, and their expanded (k = 2) uncertainty was within 50 ppm. To obtain absolute values of density, thermodynamic integration was performed using recent accurate speed of sound measurements in the stable liquid region. An empirical equation of state (EoS) was developed, giving specific volume as a rational function of pressure and temperature. The new experimental data are represented by EoS within their experimental uncertainty. Gibbs energy was obtained by EoS integration allowing computation of all thermodynamic properties of heavy water using Gibbs energy derivatives. Although based on data in relatively narrow temperature and pressure ranges, the developed EoS shows an excellent agreement with literature data for densities, isothermal compressibilities, and isobaric expansivities of deeply supercooled heavy water. The curvature of the thermodynamic surface steeply increases toward low temperatures and low pressures, thus supporting the existence of the hypothesized liquid-liquid coexistence boundary in a close vicinity of existing experimental data. [ABSTRACT FROM AUTHOR]

The process of inserting/deleting a particle during grand-canonical Monte-Carlo (MC) simulations is investigated using a novel, original technique: the trial event is made of a short nonequilibrium molecular dynamics (MD) trajectory during which a coordinate w along a 4th dimension is added to the particle in the course of insertion/deletion and is forced to decrease from large values down to zero (for insertion) or increased from 0 up to large values (for extraction) at imposed vw velocity. The probability of acceptation of the whole MC move is controlled by the chemical potential and the external work applied during the trajectory. Contrary to the standard procedures which create/delete suddenly a particle, the proposed technique gives time to the fluid environment to relax during the gradual insertion/extraction before the acceptation decision. The reward for this expensive trial move is a gain of many orders of magnitude in the success rate. The power and wide domain of interest of this hybrid "H4D" algorithm which marries stochastic MC and nonequilibrium deterministic MD flavors are briefly illustrated with hard sphere, water, and electrolyte systems. The same approach can be easily adapted in order to measure the chemical potential of a solute particle immersed in a fluid during canonical or isobaric simulations. It then becomes an efficient application of the Jarzynski theorem for the determination of solvation free energy. [ABSTRACT FROM AUTHOR]

The energetic molecular crystal cyclotrimethylene trinitramine (HMX) is a key constituent in common plastic bonded explosives. Its plastic deformation under shock conditions is important in reaction initiation and detonation. Here, we study the effect of high pressure on dislocation slip using isothermal-isobaric atomistic simulations. We consider two slip planes, (011) and (101) , that are reported to be most active under ambient conditions. For all slip systems considered, the effect of pressure is to increase the critical resolved shear stress for dislocation slip. Pressure may fully inhibit dislocation-based plasticity if the resolved shear stress is not increased in proportion. On the other hand, at sufficiently high shear stresses, the crystal loses shear stability. Therefore, in a broad range of shock conditions, plastic deformation takes place by a combination of dislocation glide in some slip systems and localization in some other systems, with dislocation activity being gradually inhibited as the shock pressure increases. This provides new data on the physical basis of plastic deformation in HMX, indicating that mesoscale representations of plasticity must include shear localization, which is more important under these conditions than dislocation plasticity. [ABSTRACT FROM AUTHOR]

We introduce a molecular simulation method to compute the interfacial properties of model systems within the isothermal-isobaric ensemble. We use a free-energy-based approach in which Monte Carlo simulations are employed to obtain an interface potential associated with the growth of a fluid film from a solid substrate. The general method is implemented within "spreading" and "drying" frameworks. The interface potentials that emerge from these calculations provide direct access to spreading and drying coefficients. These macroscopic properties are then used to compute the liquid-vapor surface tension and the contact angle of a liquid droplet in contact with the substrate. The isothermal-isobaric ensemble provides a means to change the thickness of the fluid film adjacent to the substrate by modifying the volume of the simulation box. Molecular insertions and removals are not necessary. We introduce a framework for performing local volume change moves wherein one attempts to modify the density of a narrow region of the simulation box. We show that such moves improve the sampling efficiency of inhomogeneous systems. The approach is applied to a model system consisting of a monatomic Lennard-Jones fluid in the vicinity of a structureless substrate. Results are provided for direct spreading and drying interface potential calculations at several temperatures and substrate strengths. Expanded ensemble techniques are used to evaluate interfacial properties over a wide range of temperatures and substrate strengths. The results obtained using the isothermal-isobaric approach are compared with those previously obtained via a grand canonical approach. [ABSTRACT FROM AUTHOR]

In the Western Gneiss Region in Norway, mafic eclogites form lenses within granitoid orthogneiss and contain the best record of the pressure and temperature evolution of this ultrahigh‐pressure (UHP) terrane. Their exhumation from the UHP conditions has been extensively studied, but their prograde evolution has been rarely quantified although it represents a key constraint for the tectonic history of this area. This study focused on a well‐preserved phengite‐bearing eclogite sample from the Nordfjord region. The sample was investigated using phase‐equilibrium modelling, trace‐element analyses of garnet, trace‐ and major‐element thermobarometry and quartz‐in‐garnet barometry by Raman spectroscopy. Inclusions in garnet core point to crystallization conditions in the amphibolite facies at 510–600°C and 11–16 kbar, whereas chemical zoning in garnet suggests growth during isothermal compression up to the peak pressure of 28 kbar at 600°C, followed by near‐isobaric heating to 660–680°C. Near‐isothermal decompression to 10–14 kbar is recorded in fine‐grained clinopyroxene–amphibole–plagioclase symplectites. The absence of a temperature increase during compression seems incompatible with the classic view of crystallization along a geothermal gradient in a subduction zone and may question the tectonic significance of eclogite facies metamorphism. Two end‐member tectonic scenarios are proposed to explain such an isothermal compression: Either (1) the mafic rocks were originally at depth within the lower crust and were consecutively buried along the isothermal portion of the subducting slab or (2) the mafic rocks recorded up to 14 kbar of tectonic overpressure at constant depth and temperature during the collisional stage of the orogeny. [ABSTRACT FROM AUTHOR]

Solubility of CO 2 in ionic liquids (ILs) is of great importance in absorption refrigeration system as new working pairs. Vapor-liquid equilibrium (VLE) of CO 2 in [BMP][Tf 2 N] (1-butyl-1-methyl-pyrrolidine bis(trifluoromethylsulfonyl)imide) is carried out experimentally using the experiment system at temperature range 303.15 K-363.15 K. The experimental results show that the solubility of CO 2 in [BMP][Tf 2 N] can reach up to 0.1235–0.5324 (molar fraction) within temperature range 283.15∼363.15 K and pressure range of 0.2∼5 MPa. The solubility of CO 2 in [BMP][Tf 2 N] increases with increase of temperature and pressure. The VLE data of CO 2 -[BMP][Tf 2 N] binary system is correlated with two models (SRK equation of state +WS mixing rule +UNIFAC activity coefficient model and PR equation of state +WS mixing rule +UNIFAC activity coefficient model). The excess Gibbs free energy (GE), excess enthalpy (HE) and excess entropy (SE) of the system are obtained and the interaction parameters k ij is regressed based on the VLE of CO 2 -[BMP][Tf 2 N] binary system. The variation trend of GE, HE and SE are obtained with temperature, pressure and molar fraction of CO 2. The calculation results show that the accuracy of SRK equation of state is slightly higher than that of PR equation of state in CO 2 -[BMP][Tf 2 N] binary system. The accuracy of SRK equation of state and PR equation of state decreases with increase of temperature and pressure. [ABSTRACT FROM AUTHOR]

In the article, the real and optimal hourly thermal energy balance of the helical compressor was designed. Through a technically feasible measure, the specific consumption of the helical compressor was reduced, and the effective heat recovered was then calculated. [ABSTRACT FROM AUTHOR]

Elastic properties of strongly anisotropic hard cyclic tetramers are studied in the isobaric–isothermal ensemble using Monte Carlo simulations. The tetramers are model molecules consisting of four hard disks of diameter σ with centers forming a square of side d. Recently, it was shown that 2D crystals of hard cyclic tetramers (with anisotropy parameter α=d/σ=1.7) can form a chiral phase, which is (completely) auxetic, that is, its Poisson's ratio is negative in all directions. Herein, the complete pressure dependence of the Poisson's ratio of the tetramer crystalline phase is presented. These studies show that the auxetic properties occur over a wide pressure range, but the tetramer system is only partially auxetic at low pressures. The Poisson's ratio of the system varies with pressure between −0.597(3) and 0.500(3). [ABSTRACT FROM AUTHOR]

At ambient conditions two liquids, bromoethane, C2H5Br (MBE, m.p. 154.6 K) and iodoethane, C2H5I (MIE, m.p. 162.1 K), have been crystallized under both isobaric and isochoric conditions using in situ low‐temperature and high‐pressure techniques. The single‐crystal X‐ray diffraction studies, supported by the isothermal compressibility and isobaric differential scanning calorimetry measurements, allowed the monitoring and analysis at low temperature and high pressure of the effects of externally induced changes in MBE and MIE. The monoclinic MBE and MIE crystals are found to be isostructural. They are stable, in the investigated regimes, i.e. down to 100 K/0.1 MPa and up to ∼295 K/3.7 GPa, without undergoing any symmetry or phase change. Both the contraction and compression is mainly noted for the intermolecular separation distances. The Hirshfeld surface analysis of intermolecular contacts clearly shows the nature of occurrence and hierarchy of interactions pointing out the role played by Br/I...Br/I contacts, in particular at ambient temperature and high‐pressure conditions. The preferences for the formation of intermolecular contacts in MIE are more pronounced and do not require such extreme conditions as in the case of MBE. It is notable that the Br/I...Br/I and Br/I...H contacts could be basically classified as type‐I interactions. [ABSTRACT FROM AUTHOR]

Pressure and temperature induced valence changes in the Kondo insulator SmB 6 have been investigated using x-ray absorption spectroscopy (XAS) along several isobaric cooling runs and one isothermal compression. The average valence of Sm at various pressure and temperature conditions is extracted from high quality XAS data by peak fitting procedures. The temperature dependence of the Sm valence at ambient pressure shows changes of slope near the known characteristic temperatures of gap formation (120 K) and the in-gap state (50 K). At higher pressures the average valence also shows similar temperature dependent trends upon cooling but the slope changes are less pronounced. This behavior is discussed in relation to the possible existence of an underlying first order valence transition and its critical end point. At constant temperature (T = 20 K), the Sm valence increases rapidly with pressure; however, it remains far below the expected integer value (3+) near the onset of the magnetic ordering and gap closure. In addition, the local structure of SmB 6 at ambient conditions has been analyzed using extended x-ray absorption fine structure. • Pressure effects on the temperature dependence of Sm valence have been investigated. • Indications of a possible correlation between Kondo insulating behavior and critical valence fluctuations in SmB 6 have been observed. • Local structure of SmB 6 has been investigated using EXAFS refinements. [ABSTRACT FROM AUTHOR]

• Density measurements were conducted for the mixture of 1-butanol and two biodiesels under high-pressure conditions (up to 100 MPa). • Excess volumes were calculated for the blend of 1-butanol + biodiesel. • Correlation with the Tammann-Tait equation was performed, and derived properties were calculated. • Thermodynamic modeling was carried out using the PC-SAFT equation of state. Biodiesel, derived from renewable sources, offers advantages like biodegradability and compatibility with diesel engines. However, high production costs and low-temperature viscosity issues must be addressed. This could be mitigated by blending biodiesel with medium-chain alcohols. This study aims to assess the volumetric properties of the 1-butanol + biodiesel system under high-pressure conditions (0.1 – 100 MPa) and various temperatures (293.15 – 373.15 K) using a DMA HPM device from Anton Paar. Integrating experimental and modeling approaches, we applied equations to obtain derived properties and correlate density data. Equations such as Tammann-Tait and PC-SAFT were applied to the experimental data, yielding maximum mean absolute percentage deviations (DMRA Max.) of 0.011 % and 0.439 %, respectively, indicating satisfactory fits to the experimental data. The excess volumes were calculated, revealing minimal deviation from ideal behavior, with a maximum deviation of 0.15 % of the total volume. This suggests that the volumetric behavior of the 1-butanol + methyl biodiesel system closely resembles that of an ideal solution. We used both equations to obtain derived properties, such as the compressibility (κ T) and the isobaric thermal expansivity (α P). It was observed that the PC-SAFT equation has some limitations in its prediction. From these results, a crossing point in isobaric thermal expansivity (α P) was observed; this could be attributed to increasing biodiesel content, potentially linked to the effects of intermolecular forces. [ABSTRACT FROM AUTHOR]

Isothermal-isobaric path integral centroid molecular dynamics simulations were conducted for fluid 4He at more than 600 state points in the proximity of the critical point to reveal the detailed states and relevant quantumness underlying the supercritical state. Through intensive analyses of the thermodynamic, dynamic, and quantum properties, we revealed the hidden state boundaries that separate the liquid-like and gas-like states in the supercritical region of this fluid. The Widom line, defined as the locus of the maxima of isobaric heat capacity CP, is also the quantum boundary at which there are changes in the isobaric temperature-dependence of the quantum wavelength, λquantum, i.e., maximum amplitude of the Feynman imaginary-time paths (necklaces) of individual atoms. The Frenkel line, the famous dynamic state boundary, was observed to start from nearly the same point, 0.73-0.76 Tc, on the P-T plane as observed for classical fluids. Several state boundaries based on the new criteria were found to emanate from the critical point or its vicinity on the P-T plane and are discussed in comparison with these boundaries. The quantumness of this fluid was expressed as (a) non-classical significant depression of CP observed in the liquid-like state; (b) the depression of the slopes dP/dT of the Widom line and the liquid-gas coexistence line near the critical point; and (c) the depression of the heat of pseudo-boiling across the Widom line. This is explained in terms of the decreasing kinetic energy with temperature observed in the liquid-like state below the Widom temperature TWidom, or alternatively in terms of the lattice model heat capacity, including the λquantum. [ABSTRACT FROM AUTHOR]

Murphy and Koop's 2005 equation is used as a standard for vapor pressure in supercooled water. Recently, however, new measurements of molar heat capacity of supercooled water have emerged that both show a more rapid increase in isobaric heat capacity in the supercooled region and penetrate well below the homogeneous nucleation limit. These new data lead to the need to recalculate the saturation vapor pressure in the supercooled region. An equation describing the temperature dependence of the saturation vapor pressure in the temperature interval from 150 K to 273.16 K is presented. [ABSTRACT FROM AUTHOR]

As part of the work the high-pressure sorptomat - a novel apparatus for sorption tests under conditions of high gas pressure was developed. The sorption measurement is carried out using the volumetric method, and the precise gas flow pressure regulator is used in the device to ensure isobaric conditions and regulate the sorption pressure in the range of 0-10 MPa. The uniqueness and high precision of sorption measurements with the constructed apparatus are ensured by the parallel use of many pressure sensors with a wide measurement range as well as high precision of measurement - due to the use of precise pressure sensors. The obtained results showed, i.a. that the time of reaching the isobaric conditions of the measurement is about 6-7 seconds and it is so short that it can be considered a quasi-step initiation of sorption processes. Moreover, the results of the measurement pressure stabilization tests, during the CO2 sorption test on activated carbon, have shown that the built-in pressure regulator works correctly and ensures isobaric sorption measurement conditions with the precision of pressure stabilization of ±1% of the measurement pressure. The maximum range of sorption measurement using the high-pressure sorptomat is 0-86 400 cm3/g, and the maximum measurement uncertainty is ±2% of the measured value. The activated carbon sample used for the tests was characterized by a high sorption capacity, reaching 104.4 cm³/g at a CO2 pressure of 1.0 MPa. [ABSTRACT FROM AUTHOR]

In our previous report, an empirical partition function, f , for polyethylene (PE) was determined based on a pressure (PV) – temperature (TV) – volume (V) – entropy (SV) equation of state where the variables, PV, TV and SV, were isochoric variables with V = const. evaluated by using the experimental P-V-T data and the isobaric heat capacity, CP, at 1 atm. In this work we describe the proposal of a modified, reformed partition function of the Debye model, l n f m − R D , where the l n f m − R D is expressed by the summation of the terms of T, T−1 and T3 and the Boltzmann factors of e − i θ 1 T for i = 1, 2, 3 and 6. The modified reformed pressure, P m − R D , at constant volume calculated based on the l n f m − R D showed that the Boltzmann factors, e − i θ 1 T , for i = 3 and 6 were dominant and increased with increasing temperature and the T 2 and T 4 terms were negative and decreased with increasing temperature, while the modified reformed entropy, S m − R D , showed that the Boltzmann factors of e − i θ 1 T for i = 3 and 6 were also dominant and increased with increasing temperature and the T 3 term increased rapidly over a higher temperature range. All Boltzmann factors of e − i θ 1 T for i = 1, 2, 3 and 6 in the modified reformed isochoric heat capacity, CV,m-RD, calculated based on the l n f m − R D , were positive, which was different from that in the previous work where one negative Boltzmann factor was observed. [ABSTRACT FROM AUTHOR]

Equations of state for n-hexadecane (C16H34) and n-docosane (C22H46) have been developed as functions of the Helmholtz energy with independent variables of temperature and density. The equations were developed based on experimental values of density, speed of sound, isobaric heat capacity, and vapor pressure. With these equations, all thermodynamic properties of n-hexadecane and n-docosane can be calculated. For n-hexadecane, the uncertainty in vapor pressure is 0.5 %. The uncertainty of the saturated liquid density is 0.05 % from the triple point up to 400 K, and 0.2 % at higher temperatures. The uncertainty in densities is within 0.5 %. The speed of sound and isobaric heat capacity can be calculated within 0.25 %. The uncertainties of the properties calculated with the equation for n-docosane are 5 % for vapor pressure, 0.1 % for saturated liquid density, 1 % for density, 0.5 % and 1 % for speed of sound at atmospheric pressure and higher pressures, respectively, and within 3 % for heat capacity. [ABSTRACT FROM AUTHOR]

• Physico-chemical parameters are involved through the grand canonical ensemble. • The internal energy of the WPT-AC/ethanol and M-AC/ethanol systems are calculated. • The enthalpy and entropy functions of the adsorption cooling cycles are derived. • The COP is calculated by means of statistical physics treatment • Discussion of the obtained COP for different two cycles was showed. Thermodynamic analysis of two different adsorption cooling cycles was presented; the first cycle is based on an isobaric adsorption process and the second one projects an isothermal adsorption instead of an isobaric adsorption. These cooling cycles are carried out by employing the grand canonical ensemble of the statistical physics formalism. This investigation is done for two different adsorbate/adsorbent pairs i.e. Ethanol/Waste Palm Trunk (WPT-AC) and Ethanol/Mangrove wood (M-AC). The corresponding adsorption isotherms have been fitted by statistical physics models to give a description of the adsorption process through interpretations of the evolution of the involved physico-chemical parameters, specific for this process. The results showed that the ethanol molecules have been mainly adsorbed with a multimolecular process and non-parallel to the adsorbent surface involving an aggregation process before molecules adsorption. Their adsorption energies are varying from 1.40 to 3.64 kJ/mol for WPT-AC and from 3.2 to 3.81 kJ/mol for the M-AC. These values reflected a physisorption process. The calculated internal energy values suggested the exothermicity and the spontaneity of the ethanol adsorption process. The investigation aims providing a methodology of calculation of the COP for an adsorption cooling cycle by using the statistical physics treatment. The entropy and the enthalpy functions are calculated and used to perform the thermodynamic evaluation and to calculate the coefficient of performance (COP). This parameter was found to be in the interval [0.12–0.69] for ethanol/WPT-AC and [0.11-0.6] for ethanol/M-AC for the first cycle and for the second cycle [0.15-0.81] and [0.15-0.74] respectively. [ABSTRACT FROM AUTHOR]

The pressure–volume–temperature–entropy equations of state, P–V–T–S Eos, of polyethylene (PE) for its isothermal, isobaric and isochoric ensembles were reported in our previous report (Part 1). In this report the correlation between the P–V–T–S Eos in the various ensembles was analyzed quantitatively where it was found that the three dimensional P–T–V plane for the PT–T–VT Eos in the isothermal ensemble was almost the same as that for the P–TP–VP Eos in the isobaric ensemble, while the 3D T–P–S plane for the T–PT–ST Eos in the isothermal ensemble was almost the same as that for the TP–P–SP Eos in the isobaric ensemble where the subscript of T and P mean isothermal and isobaric ensembles, respectively. The isothermal bulk modulus, κ T , and its first and second pressure derivatives ( ∂ κ T ∂ P ) T , and ( ∂ 2 κ T ∂ P 2 ) T , were calculated and it was found that the 3D T–PT– κ T plane in the isothermal ensemble was almost the same as that for the TP–P– κ T in the isobaric ensemble, and the 3D T–PT– ( ∂ K T ∂ P ) T plane in the isothermal ensemble was different only slightly from the 3D TP–P– ( ∂ K T ∂ P ) T plane in the isobaric ensemble, while a considerable difference was observed between the 3D T–P– ( ∂ 2 K T ∂ P 2 ) T planes for the isothermal and isobaric ensembles. [ABSTRACT FROM AUTHOR]

A review of recent advances in the study of the energy splitting between excited isobaric analogue states is presented. Some of the experimental developments, and new approaches, associated with spectroscopy of the most proton-rich members of isobaric multiplets, are discussed. The review focuses on the immense impact of the shell-model in the analysis of energy differences and their interpretation in terms of nuclear structure phenomena. [ABSTRACT FROM AUTHOR]

A new fundamental equation of state is presented for 2,3,3,3-tetrafluoroprop-1-ene (R1234yf). The equation is valid from the triple point temperature (121.6 K) to 410 K at pressures up to 100 MPa, where typical expanded uncertainties (k = 2) in calculated properties from the equation are 0.1 % for vapor pressures at temperatures above 270 K and 0.3 % at lower temperatures, 0.1 % for liquid densities at pressures below 40 MPa and 0.25 % at higher pressures, 0.2 % for vapor densities, 0.02 % for vapor phase sound speeds, 0.05 % for liquid phase sound speeds, 1 % for vapor phase isobaric heat capacities, 2 % for liquid phase isobaric heat capacities, and 2 % for liquid phase isochoric heat capacities. At very low temperatures around 200 K, uncertainties for vapor pressures may be larger than 0.5 %. Various plots of constant-property lines demonstrate that not only does the equation exhibit correct behavior over all temperatures and pressures within the range of validity, but also that it shows reasonable extrapolation behavior at extremely low and high temperatures, and at high pressures and densities. The equation of state is the best currently available property representation for R1234yf, and has been adopted as an international standard by the ISO working group, which recently revised ISO/DIS 17584 (Refrigerant properties). [ABSTRACT FROM AUTHOR]

Due to the advantages of high temperature stability, low corrosion, and good heat transfer performance, potassium nitrate aqueous solution holds application potential in absorption systems. In order to further improve its absorption ability, ionic liquids (ILS) such as [Emim]Cl, [Emim]Ac, and [Emim]Br were selected as additives. In this paper, vapor pressures of four {KNO3 + ILS + H2O} ternary systems were measured by a dynamic boiling point method, including {KNO3 + [Emim]Cl + H2O}, {KNO3 + [Emim]Ac + H2O}, {KNO3 + [Emim]NO3 + H2O}, and {KNO3 + [Emim]Br + H2O}. Molar ratios between KNO3 and ILs were 1:1 for these systems, and the total absorbent mass fractions were in the range of 0.20 to 0.70. Experimental data were regressed by Antoine-type equations, and the average absolute relative deviations (AARD%) between the experimental and calculated values were no more than 0.78%, which showed good consistency of these experiments. Vapor–liquid equilibrium behavior of these different ionic liquid ternary systems were compared and [Emim]Ac showed best performance in reducing vapor pressure at relatively higher mass fractions. [ABSTRACT FROM AUTHOR]

This work aims to present results of density (ρL), isobaric thermal expansivity coefficient (αP,L) and isothermal compressibility coefficient (kT,L) correlations for n-dodecane and n-nonane as a function of temperature and pressure, able to obtain these properties at any temperature and pressure in the range of 4 °C to 40 °C and 0.1 MPa to 15.0 MPa, with low uncertainties (in the case of n-dodecane: 0.00025 g⋅cm−3 for ρL; 0.00020 °C−1 for αP,L and 0.00022 MPa−1 for kT,L and in the case of n-nonane: 0.00026 g⋅cm−3 for ρL; 0.00006 °C−1 for αP,L and 0.00032 MPa−1 for kT,L). The density measurements were performed using a pycnometer that was calibrated which presents a volume uncertainty of 0.020 cm3. [ABSTRACT FROM AUTHOR]

The present study was carried out in the frame of the optimization of the synthesis process of 1,1,4,4-tetramethyl-2-tetrazene (TMTZ), a prospective liquid propellant. The liquid–liquid (LL) equilibria of the TMTZ + H2O binary system were studied under atmospheric pressure and in the temperature range from 278.15 up to 348.15 K. These results established the conditions leading to a spontaneous demixing of TMTZ from the aqueous synthesis solutions. The experimental study of the liquid–vapor (LV) equilibria of the TMTZ + H2O system using DSC, under atmospheric pressure, highlighted the various equilibrium domains involved in the distillation step. Besides, a heteroazeotropic invariant was identified at TH = 366.3 K for x (TMTZ) = 0.254. Lastly, the thermodynamic modeling of those equilibria, using various models (Van Laar, NRTL, Wilson), enabled to improve the experimental results in order to enhance the extraction conditions leading to the production of ultra-pure TMTZ. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulations of an embedded atom copper system in the isobaric-isenthalpic ensemble are used to study the effective solid-liquid interfacial free energy of quasi-spherical solid crystals within a liquid. This is within the larger context of molecular dynamics simulations of this system undergoing solidification, where single individually prepared crystallites of different sizes grow until they reach a thermodynamically stable final state. The resulting equilibrium shapes possess the full structural details expected for solids with weakly anisotropic surface free energies (in these cases, ~5% radial flattening and rounded [111] octahedral faces). The simplifying assumption of sphericity and perfect isotropy leads to an effective interfacial free energy as appearing in the Gibbs-Thomson equation, which we determine to be ~177 erg/cm², roughly independent of crystal size for radii in the 50-250 Å range. This quantity may be used in atomistically informed models of solidification kinetics for this system. [ABSTRACT FROM AUTHOR]

First principles molecular dynamics simulation protocol is established using revised functional of Perdew-Burke-Ernzerhof (revPBE) in conjunction with Grimme's third generation of dispersion (D3) correction to describe the properties of water at ambient conditions. This study also demonstrates the consistency of the structure of water across both isobaric (NpT) and isothermal (NVT) ensembles. Going beyond the standard structural benchmarks for liquid water, we compute properties that are connected to both local structure and mass density fluctuations that are related to concepts of solvation and hydrophobicity. We directly compare our revPBE results to the Becke-Lee-Yang-Parr (BLYP) plus Grimme dispersion corrections (D2) and both the empirical fixed charged model (SPC/E) and many body interaction potential model (MB-pol) to further our understanding of how the computed properties herein depend on the form of the interaction potential. [ABSTRACT FROM AUTHOR]

Particles confined to a single file, in a narrow quasi-one-dimensional channel, exhibit a dynamic crossover from single file diffusion to Fickian diffusion as the channel radius increases and the particles begin to pass each other. The long time diffusion coefficient for a system in the crossover regime can be described in terms of a hopping time, which measures the time it takes for a particle to escape the cage formed by its neighbours. In this paper, we develop a transition state theory approach to the calculation of the hopping time, using the small system isobaric-isothermal ensemble to rigorously account for the volume fluctuations associated with the size of the cage. We also describe a Monte Carlo simulation scheme that can be used to calculate the free energy barrier for particle hopping. The theory and simulation method correctly predict the hopping times for a two-dimensional confined ideal gas system and a system of confined hard discs over a range of channel radii, but the method breaks down for wide channels in the hard discs' case, underestimating the height of the hopping barrier due to the neglect of interactions between the small system and its surroundings. [ABSTRACT FROM AUTHOR]

Although the structure and dynamics of metallic glass-forming liquids have been extensively investigated, studies of the pressure effects are rare. In the present study, the structural and dynamical properties of a ternary metallic liquid are systematically studied via extensive molecular dynamics simulations. Our results clearly show that, like isobaric cooling, isothermal compression could also slow down the dynamics of metallic liquid, leading to glass formation. However, the temperature- and pressure-induced glass transitions differ in the formation of local coordination structures and the variation of fragility. The increase of the kinetic fragility with increasing pressure is also accompanied by a monotonic structural fragility change. These findings may suggest a link between dynamics and structure. In addition, with increasing pressure, the dynamics becomes more heterogeneous, as revealed by the non-Gaussian parameter and dynamic correlation length. Here the length scales of both slow and fast domains are examined and discussed by analyzing the four-point dynamic structure factor associated with spatial correlations of atomic mobility. These correlation lengths coexist in the metallic liquids and grow comparatively in the considered temperature and pressure ranges. Finally, the scaling relation between the relaxation times and correlation lengths is discussed, which is found to be consistent with the spirit of Adam-Gibbs and random first-order transition theories. [ABSTRACT FROM AUTHOR]

[Display omitted] • Presents a new semiempirical adsorbed phase activity coefficient model. • Proves thermodynamic consistency through model derivation and end-behavior analysis. • Model validated using over 25 systems after thoroughly testing data quality. • Binary and ternary adsorption predicted using Real Adsorbed Solution Theory. • Presents new binary adsorption data obtained using the Integral Mass Balance Method. The following study introduces a new adsorbed phase activity coefficient model, the SPLINT model, for describing nonideal multicomponent systems. The derivation is presented and simplification to the thermodynamically robust ABC model in the low‑coverage limit is shown. Both the SPLINT and ABC models are fit to 25 binary systems. Thermodynamic consistency of the data is established through multiple consistency tests including the intersection rule, closed‑loop reduced spreading pressure integration, the Gibbs‑Duhem integral equality, and alignment of pure and binary data. Regressed parameters are used in Real Adsorbed Solution Theory to predict both binary and ternary adsorption. The ABC and SPLINT models accurately describe systems with considerable nonideality when the activity coefficients are symmetric; however, the SPLINT model is required for accurate description of systems with complex, asymmetric activity coefficient behavior. The new model includes one more fitting parameter than the ABC model for a single binary system, but less across multiple data sets and higher‑order systems due to the theoretical basis. The importance of capturing activity coefficient asymmetry is demonstrated with a highly nonideal system across various pressures and temperatures measured by the present authors using the Integral Mass Balance method with HFC‑125 (pentafluoroethane), HFC‑32 (difluoromethane), and zeolite H‑ZSM‑5. The theoretical basis of the SPLINT model is further enforced by presenting two methods for predicting activity coefficients with the SPLINT model: correlating the fitting parameters individually and simultaneously regressing pure isosteric heat data to extract SPLINT fitting parameters. The study concludes with a discussion of pure and binary HFC‑125/HFC‑32 data with zeolite H‑ZSM‑5. A possible binary adsorption mechanism is proposed based on isosteric heat and excess enthalpy predictions and observed system irreversibility. [ABSTRACT FROM AUTHOR]

We present a simultaneous broad-band analysis of X-ray data obtained with the XMM – Newton and the Nuclear Spectroscopic Telescope Array (NuSTAR) for the asynchronous polar source, CD Ind. The spin-folded light curve in the soft 0.3–3.0 keV band shows a single broad hump-like structure superimposed with occasional narrow dips, indicating a single-pole accretion model with a complex intrinsic absorber. Lack of strong modulation in the folded light curve above 3 keV reveals that emission from the corresponding zone of the post-shock region (PSR) remains in view throughout the spin phase. The broad-band spectrum is modelled with a three-component absorbed plasma emission model and absorbed isobaric cooling flow model, both of which fit the data well with similar statistical significance. The presence of a partial covering absorber is evident in the spectra with equivalent column density |${\sim}7\times 10^{22}\, \text{cm}^{-2}$| and a covering fraction of ~25 per cent. Strong ionized oxygen Kα line emission is detected in the spectra. We notice spectral variability during the spin phase 0.75–1.05, when there is a considerable increase in the column density of the overall absorber (from |${\sim}1 \times 10^{20}\, \text{cm}^{-2}$| to |${\sim}9 \times 10^{20}\, \text{cm}^{-2}$|⁠). We required at least three plasma temperatures to describe the multitemperature nature of the PSR. The shock temperature |${\sim}43.3_{-3.4}^{+3.8}$| keV, represented by the upper temperature of the cooling flow model, implies a white dwarf mass of |${\sim}0.87^{+0.04}_{-0.03}\, \mathrm{M}_{\odot }$|⁠. The iron Kα line complex show strong He-like and weak neutral fluorescence lines. We could not unambiguously detect the presence of Compton reflection in the spectra, which is probably very small and signifies a tall shock height. [ABSTRACT FROM AUTHOR]

The internal energy, U, of polyethylene (PE) was determined by the relations that d U = C V d T + ( γ V T − P) d V and the pressure-volume-temperature-entropy equation of state (P-V-T-S Eos) evaluated by the experimental P-V-T data and Cp at 1 atm for PE where CV is the isochoric heat capacity, γ V is the thermal pressure coefficient and CP is the isobaric heat capacity. The 3-dimensional (3D) plot, 3D plot, with the three axes, x = VU, y = SU, z = TU expressed by the 3D (VU, SU, TU), the 3D (TU, PU. SU) or the 3D (TU, VU, PU) at constant U in PE were determined where the four variables, PU, VU, TU, and SU were determined under U being constant. The P-V-T-S behaviors under the iso-internal energy process where U is constant were monitored by the 3D (VU, SU, TU). The 3D (V, T, P) plot for PE under γ V T − P = 0 were expressed by a line not a plane . [ABSTRACT FROM AUTHOR]

The Kohistan island arc represents a >50 km thick and completely exposed Late Cretaceous–Eocene Neo‐Tethyan island arc sequence between the Indian and Eurasian plates in the western Himalaya. At the base of the Kohistan Arc, the Jijal Complex exposes a continuous sequence from ultramafic upper mantle rocks to mafic rocks of the lower crust across the Moho transition zone. In the shallower mafic section of the Jijal Complex, widespread garnet–clinopyroxene gabbros are uniform in assemblage but show a spectrum of microstructural variation involving two distinguishable styles of garnet growth. Uncertainty surrounds the genetic origin of these equilibria across the sequence which have been variably proposed to derive either from (a) dehydration melting of amphibole‐bearing precursor rocks, (b) subsolidus recrystallization of gabbronorite, or (c) primary magmatic crystallization. Owing to extensive high‐T re‐equilibration, compositional records of magmatic precursors and the pre‐peak evolution across the complex have been erased. However, quantitative textural analysis evidences a progressively increasing departure from microstructural randomness from deep to shallow levels of the upper Jijal Complex. This is interpreted to reflect the increased propensity for shallow garnet–clinopyroxene gabbros to have been derived from solid‐state recrystallization of a cumulate gabbronorite precursor, resulting in the development of coronitic garnet microstructures. In the deepest portions of the mafic sequence, both cumulate textures and thermodynamic modelling attest to the basal levels of the Kohistan arc crust at ~10–14 kbar crystallizing primary magmatic garnet and clinopyroxene from low H2O (<6 wt%) basaltic–andesitic melts. Granulite facies metamorphism and re‐equilibration across the whole upper Jijal Complex—shown via phase equilibrium modelling to be associated with over‐accretion in the mid‐arc crust and a pressure increase of 2–3 kbar to 850–1,050℃ and 11–14 kbar—was followed by a period of approximately isobaric cooling across ~200℃ and amphibolitization. Compositions of low‐volume leucosome‐hosted garnet indicate melting occurred prior to, or during, this re‐equilibration period and melt reintegration simulations suggest that dehydration melting of amphibole‐bearing precursors played only a minor role in the genesis of the Jijal garnet–clinopyroxene gabbros. By combining field relationships, petrological and textural analysis, interpretations of mineral compositions, and phase equilibrium modelling, we therefore provide detailed constraints on crustal thickening and the thermal evolution of the lowermost arc crust. [ABSTRACT FROM AUTHOR]