The aqueous solution of 2-butoxyethanol (2-BE) represents a prototypical amphiphilic binary system that exhibits a well-defined liquid–liquid (L-L) critical point. Owing to its molecular structure, 2-BE acts as a hydrotrope and weak surfactant, participating in extensive hydrogen-bonding networks with water while simultaneously promoting hydrophobic association and microheterogeneous clustering. The mixture displays both lower and upper critical solution temperature (LCST and UCST) behavior, with the critical point located at approximately 322.15 K and a solute mass fraction of 0.25–0.33. This unique phase behavior, coupled with strong composition- and temperature-dependent structural reorganization, makes the system an excellent model for investigating phase transition and critical phenomena in associating liquids and for probing the crossover from mean-field to Ising-like critical behavior in hydrogen-bonded mixtures. In the present work, we report ultrasonic velocity data for pure 2-BE and the binary water + 2-BE system along the l-L saturation curve at temperatures from room (298.15 K) to 453.15 K. The temperature and concentration dependences of ultrasonic velocity in the mixture were measured above the UCST for eight concentrations: 0.1839, 0.2405, 0.271, 0.3014, 0.3206, 0.3666, 0.4723, 0.702, and 0.8488 wt fraction of 2-BE. Most measurements were focused near the lower (LCST) and upper (UCST) critical solution temperatures. Because the strong interactions between 2-BE and water are complex, predicting the thermodynamic behavior of the system is difficult. The presence of an LCST is characteristic of hydrogen-bonding mixtures, and the value of the LCST reflects the relative magnitude of hydrophobic/hydrophilic interactions in solution. A higher LCST value indicates a system with greater hydrophilic character.

Bio-jet fuel represents a key strategy for the aviation industry to reduce both operating costs and environmental impacts. It is a complex mixture of hydrocarbons, primarily n-alkanes, isoalkanes, cycloalkanes, and aromatics. Ethylcyclohexane is one of the representative components of bio-jet fuel. In the present work, the isochoric heat capacity (CV) of ethylcyclohexane has been measured in both the two-phase and single-phase regions along 10 liquid isochores (553.89, 657.08, 680.93, 687.84, 707.71, 733.07, 747.37, 751.18, 754.59, and 770.69) kg·m⁻3 as a function of temperature. Measurements were performed in the temperature range from (314 to 468) K at pressures up to 5.1 MPa. For each measured isochore (except 553.89 kg·m⁻3), the liquid–vapor phase transition temperatures (TS) were determined at the point where (CV) exhibits abrupt (discontinuous) behavior. The contributions of the chemical potential and vapor- pressure, quantified via the Yang–Yang strength parameter (Rμ) to the measured two-phase CV2 were evaluated. Vapor − pressures (PS-TS) of the same ethylcyclohexane sample were simultaneously measured over the temperature range (313.15–466.15) K, considerably extending available vapor-pressure data to higher temperatures. The measured saturated liquid density (ρS), vapor − pressure (PS-TS), and two-phase CV2 data were used to calculate key thermodynamic properties at saturation, including heat capacity at saturation (CS), isobaric heat capacity (CP), speed of sound (W), and adiabatic compressibility (kS) over the temperature range (321–457) K. The combined expanded uncertainties (at a 95% confidence level, k = 2) for temperature, density, pressure, and isochoric heat capacity measurements are estimated to be 15 mK, 0.15%, 0.15%, and 3%, respectively.

New high-temperature and high-pressure PVTx measurements for the binary system 1-propanol +n-octane were conducted to characterize phase behavior and thermodynamic properties in the sub-, near-, and super-critical regions (363-623 K, up to 59 MPa). The TC - x projection of the critical curve exhibits a temperature minimum at an n-octane mole fraction of x= 0.175. The experimental data reveal a continuous critical locus connecting the critical points of the pure components. To accurately determine the type of phase diagram (Type I or Type II) for this binary associating + non-associating mixture, additional phase behavior measurements at lower temperatures are required. The Krichevskii parameter was quantified as 7.40 MPa with 1-propanol as the solvent and 3.396 MPa with n-octane as the solvent. These positive values indicate that repulsive solute-solvent interactions dominate near the critical point. Analysis of critical singularities in thermodynamic properties demonstrates that the mixture exhibits non-classical scaling behavior, consistent with the isomorphism principle (Fisher's renormalization of the critical behavior of binary mixtures). Consistent with the Fisher renormalization principle, weakly singular properties (isochoric heat capacity) exhibit pure-fluid-like behavior at the 0.175 composition, whereas strongly singular properties (isothermal compressibility and isobaric heat capacity) retain mixture-like divergence across the entire composition range. The mixture with composition x= 0.175 mol fraction of n-octane displays pure-fluid-like behavior in the isochoric heat capacity, whereas strongly divergent properties such as isothermal compressibility, isobaric heat capacity, retain mixture-like behavior along the critical isochore for all compositions in the range 0 1. The cross-term (interaction) second virial coefficientsB12, characterizing 1-propanol-n-octane molecular interactions, were derived from the experimental data: B12 = -590.04 cm3 center dot mol-1 at T= 543.15 K and B12= -490.11 cm3 center dot mol-1 at T= 623.15 K. Furthermore, excess molar volumes exhibit significant negative deviations in the vicinity of the pure component critical points, reflecting the extreme sensitivity of solvent molar volume under near-critical conditions. This is universal feature of binary mixtures containing a component under near-critical conditions. These results provide reliable reference data for validating the equations of state used in modeling supercritical separation processes of alcohols and hydrocarbons.

The isochoric heat capacity of supercritical fluids is a key thermodynamic property for investigating the asymptotic behavior of the Widom line in the vicinity of the critical point. In this wrk, the experimentally determined loci of the isochoric heat capacity maxima along supercritical isotherms are analyzed for a variety of molecular fluids. The experimental results show that the Widom line originates at the critical point, initially shifts toward lower densities with increasing temperature, subsequently reverses direction, and finally approaches the critical density again. Consequently, the Widom line crosses the critical isochore twice. The observed behavior is compared with the predictions of complete and incomplete scaling theories. It is demonstrated that the experimental data are accurately described by the asymptotic relation derived from complete scaling theory, for which the leading coefficient ($\propto t^{2\beta}$, complete scaling term) is negative, $D_{\mathrm{CS}} < 0$. This prediction is in excellent agreement with the experimental observations. In contrast, incomplete scaling predicts a different asymptotic behavior ($\propto t^{1-\alpha}$) along supercritical isotherms and therefore fails to reproduce the experimentally observed evolution of the Widom line over a wide temperature range. The predictive capability of widely used multiparameter reference equations of state (NIST/REFPROP) is also examined. Although these equations of state accurately represent thermodynamic properties over broad regions of the fluid phase diagram, they fail to reproduce the correct asymptotic behavior of the Widom line in the immediate vicinity of the critical point. This deficiency arises because conventional non-scaling equations of state do not correctly capture the critical anomalies associated with long-range density fluctuations. The present results provide the first experimental confirmation of the asymptotic behavior of the Widom line predicted by complete scaling theory and demonstrate the necessity of incorporating scaling behavior into equations of state intended for accurate description of critical and supercritical fluids thermodynamic behavior.

Backgrounds: Accurate vapor-liquid equilibrium (VLE) data are indispensable for the design and optimization of processes involving supercritical-fluid extraction. Such data prevent excessive equipment sizing, enhance energy efficiency, and support reliable modeling of separation systems-particularly in oil sludge treatment, where light alkanes like propane serve as effective supercritical solvents. Propane is especially favorable due to its moderate critical parameters (TC = 369.89 K, PC = 4.25 MPa), which allow operation under milder conditions than COQ while retaining strong solvating power for heavy hydrocarbons. Methods: Isothermal VLE measurements (Pxy) for the binary mixture of supercritical propane (CsH0) and 1-phe-nylethanol were carried out at (403.15, 423.15, and 443.15) K, with pressures ranging from (1.03 to 8.76) MPa, using a high-pressure optical cell equipped with gravimetric phase sampling. Significant Findings: Critical point data and the critical locus for the CsH0 + 1-phenylethanol system were determined based on the measured PTxy data using the analytical extrapolating technique. Critical point data and the critical locus for the CsH0 + 1-phenylethanol system were extracted from the experimental VLE results. The Krichevskii parameter, a thermodynamically rigorous quantity with microscopic relevance, was evaluated from the initial slope of the critical curve. The predictive and correlative capabilities of three equations of state-Peng-Robinson (PR), PC-SAFT, and CP-PC-SAFT-were assessed against both pure-component properties and mixture VLE behavior. While PR showed an inferior performance in predicting the 1-phenylethanol's pure-compound properties and the investigated VLE in CsH0 + 1-phenylethanol system without applying binary adjustable paramteres, it provided the most accurate prediction of the reported critical points. Besides that, PR with optimized binary parameters was the most accurate model in correlating VLE. CP-PC-SAFT was found to be superior in predicting the VLE without the binary parameters, while their optimization resulted in comparable performance of both SAFT models. It was also demonstrated that PC-SAFT's overestimation of the pure-component critical temperatures and pressures leads to improvement of its accuracy in estimating critical points in the investigated temperature range.

Photovoltaic (PV) power generation is a pivotal pathway to achieve global carbon neutrality and mitigate climate change, yet its large-scale grid integration is severely hindered by two critical bottlenecks. First, the conversion efficiency of conventional PV cells is fundamentally limited by the Shockley-Queisser limit, far below the Landsberg thermodynamic limit, with massive spectral energy wasted via sub-bandgap transmission and abovebandgap thermalisation, which also accelerates cell degradation. Second, the inherent intermittency of solar radiation causes worldwide PV curtailment, while state-of-the-art energy storage technologies suffer from geographical constraints, low round-trip efficiency (RTE), high cost and environmental risks. Furthermore, existing research on compressed CO2 energy storage (CCES) focuses on cycle optimisation alone, lacking deep coupling with full-spectrum solar utilisation technologies and clarification of the system's solar harvesting efficiency limit. To address these gaps, this work proposes a novel concentrated spectral-splitting (SS) photovoltaic-thermal (PV-T) system integrated with CCES. The system leverages SS optics to separate sub-bandgap spectrum for thermal storage to elevate turbine inlet temperature, adopts multi-junction (MJ) cells to reduce thermalization loss, and integrates a closed CO2 cycle with waste heat recovery for full-spectrum solar cascade utilisation. A validated thermoelectric model is established to systematically investigate key parameters' impacts on system performance. Results show that discharging output power can exceed charging PV input at bandgap Eg >= 1.81 eV under ideal thermodynamic boundaries. The system achieves a theoretical limit RTE over 92% with MJ cells under ideal assumptions, and overall solar utilisation efficiency exceeding 70% under optimal conditions, with superior techno-economic performance for junction number <= 3.

The paper presents the results of the phase-equilibrium (VLE) study of the supercritical binary (n-butane/pro-pane) mixture (as a supercritical solvent) with the main component (heavy n-alkane, n-tricosane, n-C23H48) of asphaltene-resin-paraffin (ARP) deposits. The isothermal VLE measurements were performed at three selected temperatures of (403.15, 423.15, and 443.15) K and at pressures of up to 7.3 MPa. The results have been used to study the process of cleaning oil wells of ARP deposits using a supercritical extraction process. The sample of ARP deposits was taken from the Orenburg oil field, characterized by a high content of paraffins (33.7 %), resins (30.55 %), and asphaltene (3.9 %). Heavy hydrocarbon extraction from ARP deposition was performed using a supercritical ready-to-use binary propane/n-butane mixture solvent in the temperature range of (398-433) K and at a pressure of (5-13) MPa. The kinetics of the propane/n-butane supercritical extraction process of hydrocarbons from ARP deposits under different thermodynamic conditions were studied. The present results can be used to prevent heavy oil component deposition in production oil wells.

Bio-jet fuels are considered as promising alternatives to conventional aviation fuels due to their sustainability and environmental friendliness. The acoustic properties (speed of sound) are of great significance to the optimization of the aeroengine design and production process of bio-jet fuels. In the present work the speed of sound in pure n-octane and n-propylbenzene and their binary mixtures of n-octane + n-propylbenzene, as main components of the bio-jet fuel, has been measured at saturation in the temperature ranges from (277 to 473) K using the pulse method with a constant (acoustic) sounding base. The measurements for the binary mixture were performed for three selected compositions of (0.2, 0.5, and 0.8) mol/mol of n-propylbenzene. The combined expanded absolute and relative uncertainties (0.95 level of confidence, k = 2) of the temperature, concentration, and speed of sound measurements are estimated to be 20 mK, 0.0006 mol/mol, and 0.2 %, respectively. The measured speed of sound data for the mixture together with the values for the pure components were used to calculate the speed of sound deviations from the linear additive law as a function of temperature and mol/mol concentration of n-propylbenzene.

The effect of pressure on thermal conductivity is an important for understanding the heat transfer processes in modeling applications in geothermal reservoirs and for optimization of the technology of geothermal energy extraction processes. The primary factors affecting the economics of any geothermal energy recovery process are the amount of heat present in the geothermal reservoir and rate of heat extraction, which strongly depend on the thermal properties of the reservoir rocks, which are functions of both temperature and pressure. The present paper aims to study the variation of thermal conductivity of five sandstone samples from the Germany Geothermal Field with various total (open and close) porosities of (6.8, 13.0, 15.44, 21.3, and 21.5%) with pressure up to 203 MPa, to overcome the existing lack of thermal conductivity data for the geothermal reservoir modeling. The improved steady-state heat-flow technique (contact method) was used to precisely (with an uncertainty of 4%) measure the thermal conductivity of the sandstone samples. Unlike previous studies, in the present work the effect of the contact thermal resistance on the measured values of thermal conductivity has been taken into account using a calibration procedure to increase the accuracy and reliability of the measured data. The results show that with the increase of the pressure at a fixed temperature of 293.15 K, the thermal conductivity of sandstone is linearly increasing with pressure from 0.52 to 1.73 GPa(-1) depending on sandstone structural and mineralogical composition, porosity, and other characteristics, which falls in the same range reported by other authors for rock samples from different geothermal fields. The derived values of the thermal conductivity pressure coefficient are crucial for geothermal studies in order to effectively use the geothermal resources of the region, and are useful for scientific applications such as the development and testing of the accuracy, reliability, and predictive capability of existing thermal models of geothermal reservoirs. Based on the present experimental results, statistical analysis (correlation analysis) was revealed between the measured thermal conductivity of sandstone samples and open and close porosities. The role of closed and open porosities on the pressure dependence of thermal conductivity and elastic moduli is discussed. For the first time, we experimentally observed the difference of the influence of the open and closed porosities on the thermal conductivity and elastic properties of sandstones. It was experimentally confirmed that the effect of closed porosity on the thermal conductivity of sandstones is significantly greater than that of open porosity by 15 to 20%. The obtained results show that it is of great importance to study the changes in the thermal properties of the sandstones under pressure at realistic reservoir conditions for geothermal studies.

In the present work thermal atomic layer deposition (ALD) of aluminum-molybdenum oxide films (AlxMoyOz) using trimethylaluminum (TMA, Al(CH3)3), molybdenum dichloride dioxide (MoO2Cl2) and water was studied. The possibility of ALD molybdenum oxide (MoO3) film using MoO2Cl2 and water was also examined. The film growth process was studied in situ using a quartz crystal microbalance (QCM) technique and ex situ using various spectroscopic methods. ALD of AlxMoyOz was carried out using supercycles consisting of TMA/H2O and MoO2Cl2/H2O subcycles. The subcycle ratios were 1 : 1 and 1 : 7, which are designated as 1Al1MoO and 1Al7MoO, respectively. At 150°C, film growth is linear with a growth rate of 5.39 and 7.62 Å per supercycle for 1Al1MoO and 1Al7MoO, respectively. The density of the films were 3.44 and 3.80 g/cm3 for 1Al1MoO and 1Al7MoO, respectively. The 1Al1MoO film with a thickness of 215.8 Å had a roughness of 10–12 Å, and the film obtained from the 1Al7MoO process with a thickness of 228.7 Å had a roughness of 16–18 Å. The synthesized thin films were characterized with XPS, XRR, SE, and XRD. The oxidation state of molybdenum in the AlxMoyOz films is +6, +5, and +4. X-ray diffraction analysis showed that the films had an amorphous structure.

Based on the hypothesis of scale invariance (scaling), the review describes the main provisions of the modern nonclassical theory of critical phenomena in pure fluids. A detailed description is given to the main types (parametric and six-term or renormalized Landau expansion) of theoretically substantiated crossover equations of state (EoSs) of pure fluids and their application to describe the anomalous behavior of thermodynamic properties in sub- and supercritical fluids. It is shown that the crossover EoS model covers all the characteristic features of the scaling behavior of the thermodynamic properties of pure fluids in the asymptotic region of the critical point in the form of simple power laws with universal critical exponents and transforms into the classical EoSs (in particular, the Landau expansion) with distance from the critical (fluctuation) region. A detailed comparison is made between the predictions of the crossover EoS model and experimental data on the thermodynamic properties for a representative set of supercritical fluids in a wide range of temperatures and pressures. The crossover EoSs of pure fluids are used to quantitatively estimate the boundary of the region of influence of critical fluctuations on the thermodynamic properties, i.e., to evaluate the contribution of the fluctuation component to the experimentally observed anomalous enhancement of the thermodynamic properties of supercritical fluids. An interpretation of supercritical phase transitions (Widom lines) is given based on the concept of large-scale critical fluctuations and crossover theory. Dynamic crossover phenomena are also considered to describe the influence of fluctuations on the critical enhancement of transport properties (thermal conductivity, thermal diffusivity, and viscosity) in sub- and supercritical fluids.

Bio-jet fuel is a key element in the aviation industry to reduce operating costs and environmental impacts. Bio-jet fuel is a complex mixture of four hydrocarbons (n-alkanes, isoalkanes, cycloalkanes and aromatics). In the present work, the speed of sound in pure n-octane, ethylcyclohexane, and their mixtures with six selected compositions of (0.3004, 0.4191, 0.4999, 0.5538, 0.6991, and 0.7852 mole fraction of ethylcyclohexane) has been measured along the l-G saturation curve in the temperature ranges from (286 to 443) K using the pulse method with a constant (acoustic) sounding base. The combined expanded absolute and relative uncertainties (0.95 level of confidence, k = 2) of the temperature, concentration, and speed of sound measurements are estimated to be 20 mK, 0.0006 mole fraction, and 0.2 %, respectively. The measured speed of sound data together with our previous reported density data for the pure component (ethylcyclohexane) and the mixture were used to calculate derived thermodynamic properties, such as isentropic compressibility kS and heat capacity ratios CPCV as a function of temperature along the l-G saturation curve for the pure components and the mixture for selected concentration of x = 0.8 mole fraction of ethylcyclohexane. The deviation of the measured speed of sound data for the mixture from the linear additive rule has been determined using the pure component data.

Isothermal vapor–liquid equilibrium (VLE) data (PTxy) for the binary supercritical propane (C₃H₈) + pyridine system were measured at three isotherms, T = (403.15, 423.15, and 443.15) K, and pressures ranging from (0.89 to 7.05) MPa, using a high-temperature, high-pressure optical cell apparatus. From the measured VLE data, the vapor–liquid critical point parameters (PC, TC, xC) of the mixture were determined. The initial slope of the critical lines, together with the slope of the vapor pressure curve of pure C₃H₈ at the critical point, was employed to evaluate the Krichevskii parameter ∂P∂xTCVC∞, a theoretically significant parameter with rigorous microscopic foundations. The predictive performance of three theoretically based models with universal, system-independent binary parameters, namely PC-SAFT (with two alternative sets of pyridine molecular parameters) and CP-PC-SAFT, was assessed against the new VLE data, as well as available critical, liquid–liquid equilibrium (LLE), and excess enthalpy data for n-alkane + pyridine mixtures. The results demonstrate that CP-PC-SAFT provides superior overall reliability compared with both PC-SAFT approaches.

The isothermal VLE properties ( PTxy relationship) of a binary supercritical (SC) C3H8 3 H 8 + o-toluidine mixture was measured by means of static-analytic method with fluid phase sampling at equilibrium conditions. The measurements were made at three temperatures of (393.15, 433.15, and 473.15) K and pressures up to 10.41 MPa. An experimental VLE apparatus, a high-temperature and high-pressure optical cell, has been used to measure the phase equilibrium properties ( PTxy ) of the binary SC C3H8 3 H 8 + o-toluidine mixture. The combined expanded absolute and relative uncertainties of the temperature, pressure, and the phase concentration measurements at 0.95 confidence level with a coverage factor of k = 2 is estimated at 0.15 K, 0.5 %, 4.2 % (for x ) and 4.8 % (for y ), respectively. The critical curve data, T C- x , P C- x , and P C- T C projections, have been derived based on the measured VLE data. The measured VLE and the derived critical curve data were used to estimate the theoretically ( ) infinity important and physical meaning of Krichevskii parameter, partial derivative P partial derivative x . Thermodynamic (partial molar properties, TCVCV2 infinity, C V C V 2 infinity , H infinity 2 , C infinity P 2 , and distribution equilibrium constant K D ), and microstructural (cluster's size, N infinity exc ) properties of infinite-dilute C3H8 3 H 8 + o-toluidine mixture near the critical point of pure solvent (C3H8) 3 H 8 ) were calculated based on the derived Krichevskii parameter and pure solvent (SC C3H8) 3 H 8 ) properties. CP-PC-SAFT and mg-SAFT equation of state (EoS), with zero interaction parameter, k 12 = 0, for both models (pure prediction models, no adjustable parameters) were successfully applied to the present PTxy phase equilibria for the SC C3H8 3 H 8 + o-toluidine mixture. The present measured VLE data for C3H8 3 H 8 + o-toluidine system along with the reported pure compound properties of pure propane and o-toluidine have been used to examine the predictive capabilities of the theoretically based CP-PC-SAFT and mg-SAFT models of EoS. It was demonstrated that mg-SAFT is superior in predicting VLE of the C3H8 3 H 8 + o-toluidine system with k 12 = 0.

In this work, quantum chemical modeling was applied to study the surface reactions of molecular layering of molybdenum (VI) oxide on the surface of β-cristobalite and amorphous monolayers of MoOx and AlOx on β-cristobalite using gaseous MoOCl4, MoO2Cl2, and H2O as reagents. Using the generalized gradient approximation method of density functional theory, the Gibbs energy changes of the molecular layering reactions (ΔG°) in the temperature range from 273.15 to 650.15 K were calculated. The calculations were carried out considering the aggregate state of the reacting substances — in the approximation of an ideal gas for gaseous substances and excluding the translational and rotational contributions for the solid phase components. According to the obtained data, the highest reactivity of the surface of the amorphous aluminum oxide monolayer on β-cristobalite is predicted in the considered temperature range. Additionally, it was found that the MoOCl4 compound has greater chemical activity compared to MoO2Cl2 towards the studied substrates. An explanation is provided for the absence of molybdenum oxide structure growth on the surface of β-cristobalite and the possible reasons for the higher reactivity of the aluminum oxide monolayer compared to the β-cristobalite surface and the amorphous MoOx monolayer. Our computational approach can generally aid in understanding the fundamental aspects of nucleation and growth of MoO3 films and mixed oxide materials like AlxMoyOz on various surfaces. Additionally, the vibrational mode frequencies in molybdenum-containing structures on the substrate surfaces were calculated in the anharmonic approximation: vSi-O-Mo = 901-1002 cm⁻1, vAl-O-Mo = 921-1015 cm⁻1, vMo-O-Mo = 716-889 cm⁻1, vMo=O = 972-1010 cm⁻1. For citation: Gadjimuradov S.G., Suleymanov S.I., Maksumova A.M., Drozdov Ye.O., Abdulagatov I.M., Abdulagatov A.I. Thermodynamic modeling of the processes of molecular layering of MoO3 on β-cristobalite and monolayers of MoOx and AlOx by the DFT method: comparative evaluation of the reactions of MoOCl4 and MoO2Cl2 with H2O. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2025. V. 68. N 3. P. 50-63. DOI: 10.6060/ivkkt.20256803.7132.

In the present work, the thermal conductivity of composite materials based on glass, ceramic, and polystyrene microspheres, as well as fiberglass, bonded with a styrene-acrylic emulsion has been reported. The measurements were performed using a commercial SKZ1061C instrument manufactured by SKZ Industrial based on the transient plane source (TPS) method at room temperature and atmospheric pressure. The reliability of the measurements was confirmed through validation of two reference samples of extruded polystyrene foam with well-known thermal conductivity. The measured thermal conductivity values range between (0.0581 and 0.0905) W/(m⋅K) with an uncertainty of 2.5

The phase equilibrium properties (isothermal VLE, PTxy behavior) of the CO2 and pyridine binary mixture were studied. The measurements were carried out using a high-temperature and high-pressure optical cell. The measurements were performed at three selected supercritical isotherms of 313.15, 333.15, and 353.15 K and at pressures of up to 12.35 MPa. The liquid-vapor critical curve properties (P C, T C, x C) of the CO2 + pyridine system have been estimated using the measured VLE data. Based on the derived critical curve data, the value of the physically meaningful and theoretically important Krichevskii parameter of the mixture was estimated. The derived value of the Krichevskii parameter, together with reference thermodynamic property data of the pure supercritical solvent (CO2), can be used to calculate all thermodynamic properties of the dilute mixture near the critical point of pure CO2. The new measured VLE data were successfully calculated with the Peng-Robinson, 1978 (E-PPR78) model of the equation of state (EoS). The EoS accurately predicts the critical curve behavior of the CO2 + pyridine mixture and determines its vapor-liquid equilibrium properties across the temperature range of (313.15 to 353.15) K.

The two-phase isochoric heat capacity ( C_V2 VT), liquid–gas phase transition ( T_S , ρ_s^' ), vapor-pressure ( P_S , T_S ), and thermal -pressure coefficient ( dP_S /dT) of methyl dodecanoate, a key biofuels component, have been measured along nine liquid isochores between (180.90 and 845.31) kg·m−3 and three near-critical liquid and vapor (180.90, 234.52, and 374.11) kg·m−3 isochores. The temperature range covers the liquid–vapor phase transition temperature T_S( ρ) for each measured isochore to near the thermal decomposition temperature, 450 K. The measurements were performed using a high-temperature and high-pressure, nearly constant-volume adiabatic calorimeter previously used for the measurements of the C_V VT relationship of biofuel components in the two- and single-phase region. The combined expanded uncertainty of the density (ρ), temperature (T), and isochoric heat capacity ( C_V2 ) measurements at the 95 T_S . For each experimental liquid isochore, most measurements were concentrated in the immediate vicinity of the liquid–gas phase transition temperature ( T_S ) to precisely determine the phase boundary properties ( ρ_S , T_S , C_V1 , and C_V2 ) using an isochoric heat -capacity abrupt-behavior technique. For nine liquid isochores between (745.16 and 845.31) kg·m−3 the phase transition temperatures ( T_S ) were experimentally determined. For two vapor (180.90 and 234.52) kg·m−3 and liquid near-critical (374.11) kg·m−3 isochores, for which the transition temperatures are very high (above the thermal decomposition temperature, 473 K), we failed to reach the phase-transition temperatures, T_S , because for these isochores the thermal decomposition of methyl dodecanoate occurs before reaching the phase transition temperature (above 673 K). The measured two-phase ( C_V2 ) isochoric heat capacities as a function of specific volume (V) along the various isotherms (below 473 K) were used to accurately estimate the values of the second temperature derivatives of chemical potential, d^2μ/dT^2 , and vapour-pressure, d^2 P_S/dT^2 , based on the Yang–Yang theoretical relation. The contributions of the vapour-pressure, C_VP = VTd^2 P_S/dT^2 , and the chemical potential, C_Vμ = - Td^2μ/dT^2 , to the heat capacities of the measured total two-phase C_V2 were estimated as a function of temperature. In addition, measured C_V2 and phase boundary ( ρ_S , T_S , P_S ) property data were used to calculate key thermodynamic property data C_P , C_sat , K_TS , W_S , Δ H_V , ( ∂ P/∂ T)_V^sat. , ( ∂ V/∂ T)_P^sat. along the saturation curve. The measured vapor-pressure ( P_S − T_S ) and saturated liquid densities ( ρ_S − T_S ) were used to develop extended theoretically based scaling -type correlations and to estimate the critical property data ( T_C , P_C , and ρ_C ), asymptotical critical amplitudes, and asymmetric parameter.

This work involves the ex situ characterization of molybdenum oxide (MoO 3 ) and titanium molybdenum oxide (Ti x Mo y O z ) thin films grown by atomic layer deposition (ALD) at 150°C using titanium tetrachloride (TiCl 4 ), molybdenum oxytetrachloride (MoOCl 4 ), and water. Atomic layer deposition of Ti x Mo y O z was carried out in supercycles consisting of TiCl 4 /H 2 O and MoOCl 4 /H 2 O subcycles. Two types of Ti x Mo y O z films were prepared, where the ratio of subcycles was 1 : 1 (1Ti1MoO) and 1 : 7 (1Ti7MoO). The film growth rate was determined by spectroscopic ellipsometry (SE) and X-ray reflectivity (XRR). The density and root-mean-square roughness of the films were also determined from XRR. The composition of the films was determined by X-ray photoelectron spectroscopy (XPS). The degree of oxidation of molybdenum in the MoO 3 and 1Ti7MoO films was +6, and in the 1Ti1MoO film, molybdenum was found in the oxidation states of +5 and +6. X-Ray diffraction analysis (XRD) showed that the films were amorphous.