Temperature Dependence Of Coefficient Research Articles

ОСОБЛИВОСТІ АНІЗОТРОПНОГО БІПОЛЯРНОГО ТЕРМОЕЛЕМЕНТА

Modern information communication networks include monitoring subsystems. The operation of monitoring subsystems is based on the operation of various sensors. Among the sensors used in the monitoring subsystems, thermoelectric sensors occupy an insignificant share. In order for thermoelectric sensors to become more widespread, it is necessary to solve the problem of a small value of thermoelectric efficiency. It is proposed to solve this problem by switching to sensors based on anisotropic bipolar thermoelement. In the presented work, the influence of thermoelectric vortices with turbulent flow on the sensitivity of sensors based on anisotropic bipolar thermoelements was studied. The dependence of the value of the transverse thermal-EMF of this structure on the anisotropy coefficient K of the anisotropic bipolar thermoelectric material was determined. Corresponding singular points and limits of their existence are revealed. The dependence of the directions of rotation of vortices with a turbulent nature of the flow on the direction of approach to these points was established. The temperature sensitivity of the sensor based on an anisotropic bipolar thermoelement made of single crystals of cadmium antimonide with both unipolar and bipolar characteristics was evaluated. Research results show a significant increase in the temperature sensitivity of such sensors based on anisotropic bipolar thermoelements, which can be used as thermal sensors for monitoring individual elements of the information communication system. Such thermoelements will have an improved coefficient of temperature dependence of volt-watt sensitivity compared to anisotropic unipolar thermoelements. The conducted numerical calculations show the prospects of using anisotropic bipolar thermoelements as sensors for monitoring modern information and communication systems for collecting information, both about the system itself and the environment.

Carbon solute drag effect on the growth of carbon supersaturated bainitic ferrite: Modeling and experimental validations

The carbon partitioning and lengthening rate of bainitic ferrite (αb) are excellent experimental parameters to estimate our level of understanding of the mechanism of bainitic transformation from a continuum perspective and our ability to capture it in analytical expressions. For Fe-C alloys and relatively simple steels the classical Zener-Hillert theory captures the bainitic transformation rather well but mispredicts the level of carbon in solution in the bainite and overestimates the lengthening rates for transformations at lower temperatures. To address this issue, this paper presents a new thermo-kinetic model based on the Zener-Hillert theory and the Gibbs energy balance concept to simulate the lengthening behavior of αb in the Fe-C and low alloyed steels. The model incorporates the effect of the temperature dependent carbon diffusion within the migrating interface via a temperature dependent ferrite/austenite interfacial energy and a temperature dependent diffusion coefficient but does not impose local equilibrium across the interface. The good agreement between the model predictions and nine sets of published experiments indicates that both the carbon supersaturation in αb and the slower lengthening rate are caused by carbon diffusion within the migrating interface. It is found that the degree of carbon supersaturation in αb increases significantly with decreasing temperature. Consequently, the enhanced carbon solute drag effect, resulting from carbon diffusion within the interface, strongly retards the lengthening rates of αb at lower temperatures. Transformation strain is shown to have a modest effect on the lengthening rates but to lower the degree of carbon supersaturation.

Coupled 3D (J ≥ 0) Time-Dependent Wave Packet Calculation for the F + H2 Reaction on Accurate Ab Initio Multi-State Diabatic Potential Energy Surfaces.

We had calculated adiabatic potential energy surfaces (PESs), nonadiabatic, and spin-orbit (SO) coupling terms among the lowest three electronic states (12A', 22A', and 12A″) of the F + H2 system using the multireference configuration interaction (MRCI) level of theory, and the adiabatic-to-diabatic transformation equations were solved to formulate the diabatic Hamiltonian matrix [J. Chem. Phys. 2020, 153, 174301] for the entire region of the nuclear configuration space. The accuracy of such diabatic PESs is explored by performing scattering calculations to evaluate integral cross sections (ICSs) and rate constants. The nonadiabatic and SO effects are studied by utilizing coupled 3D time-dependent wave packet formalism with zero and nonzero total angular momentum on multiple adiabatic/diabatic surfaces calculation. We depict the convergence profiles of reaction probabilities for the reactive as well as nonreactive processes on various electronic states at different collision energies with respect to total angular momentum including all helicity quantum numbers. Finally, total ICSs are calculated as functions of collision energies for the initial rovibrational state (v = 0, j = 0) of the H2 molecule along with the temperature-dependent rate coefficient, where those quantities are compared with previous theoretical and experimental results.

Temperature-Corrected Calibration of GS3 and TEROS-12 Soil Water Content Sensors

The continuous monitoring of soil water content is commonly carried out using low-frequency capacitance sensors that require a site-specific calibration to relate sensor readings to apparent dielectric bulk permittivity (Kb) and soil water content (θ). In fine-textured soils, the conversion of Kb to θ is still challenging due to temperature effects on the bound water fraction associated with clay mineral surfaces, which is disregarded in factory calibrations. Here, a multi-point calibration approach accounts for temperature effects on two soils with medium to high clay content. A calibration strategy was developed using repacked soil samples in which the Kb-θ relationship was determined for temperature (T) steps from 10 to 40 °C. This approach was tested using the GS3 and TEROS-12 sensors (METER Group, Inc. Pullman, WA, USA; formerly Decagon Devices). Kb is influenced by T in both soils with contrasting T-Kb relationships. The measured data were fitted using a linear function θ = aKb + b with temperature-dependent coefficients a and b. The slope, a(T), and intercept, b(T), of the loam soil were different from the ones of the clay soil. The consideration of a temperature correction resulted in low RMSE values, ranging from 0.007 to 0.033 cm3 cm−3, which were lower than the RMSE values obtained from factory calibration (0.046 to 0.11 cm3 cm−3). However, each experiment was replicated only twice using two different sensors. Sensor-to-sensor variability effects were thus ignored in this study and will be systematically investigated in a future study. Finally, the applicability of the proposed calibration method was tested at two experimental sites. The spatial-average θ from a network of GS3 sensors based on the new calibration fairly agreed with the independent area-wide θ from the Cosmic Ray Neutron Sensor (CRNS). This study provided a temperature-corrected calibration to increase the accuracy of commercial sensors, especially under dry conditions, at two experimental sites.

Electronic transparency of internal interfaces in metallic nanostructures comprising light, heavy and ferromagnetic metals measured by terahertz spectroscopy

Abstract We investigate the electronic transport at the internal interface within a selection of metallic bilayer nanostructures using the contact-free, all-optical method of THz time-domain spectroscopy. The Ru/Co, Ru/Pt, and Ru/Al bilayer nanostructures and their individual constituent metals are studied, with Ru representing an archetypal d-band metal, Co an archetypal ferromagnet, and Pt and Al archetypal heavy and light metals, respectively. The THz conductivity data were analyzed in terms of Drude and Bloch–Grüneisen models, and the interface current coefficient of the internal nanointerface was determined. Strong temperature dependency of the interface current coefficient in the Ru/Co nanostructure is revealed.

Reaction rate coefficient study of the perfluoroalkyl and ω-Perfluoroalkyloic acid radicals

Temperature-dependent rate coefficients of perfluoroalkyl and ω-perfluoroalkyloic acid radicals at 500 to 2500 K were determined using previously reported potential energy surfaces characterized by the density functional theory ωB97xD/6–311+G(d,p) method. The rate coefficients were evaluated for the degradation pathways and their Arrhenius parameters were obtained. This study shows a preference for β-scission in most radicals considered, especially at high temperatures, or collisional stabilization of isomers produced via 1,2-F-shifts. The most important products of the thermal degradation of the radicals are found to be tetrafluoroethylene, trifluoromethyl, atomic fluorine, HOCO and its decomposition products, and a resonantly stabilized perfluoroethyloic •CF2C(O)OH radical.

Kinetics of the reaction of OH with methyl nitrate (223-343 K).

Rate coefficients (k4) for the reaction of hydroxyl radicals (OH) with methyl nitrate (CH3ONO2) were measured over the temperature range 232-343 K using pulsed laser photolysis to generate OH and pulsed laser-induced fluorescence to detect it in real-time and under pseudo-first-order conditions. In order to optimize the accuracy of the rate coefficients obtained, the concentration of CH3ONO2 (the reactant in excess) was measured on-line by absorption spectroscopy at 213.86 nm for which the absorption cross-section was also measured (σ213.86 = 1.65 ± 0.09 × 10-18 cm2 molecule-1). The temperature-dependent rate coefficient is described by k4(T) = 7.5 × 10-13 exp[(-1034 ± 40)/T] cm3 molecule-1 s-1 with a room temperature rate coefficient of k4(296 ± 2 K) = (2.32 ± 0.12) × 10-14 cm3 molecule-1 s-1 where the uncertainty includes the statistical error of 2σ and an estimation of the potential systematic bias of 5%. This new dataset helps to consolidate the database for this rate coefficient and to reduce uncertainty in the atmospheric lifetime of CH3ONO2. As part of this study, an approximate rate coefficient for the reaction of H-atoms with CH3ONO2 (k9) was also derived at room temperature: k9(298 K) = (1.68 ± 0.45) × 10-13 cm3 molecule-1 s-1.

On global solutions to the inhomogeneous, incompressible Navier–Stokes equations with temperature-dependent coefficients

On global solutions to the inhomogeneous, incompressible Navier–Stokes equations with temperature-dependent coefficients

Theoretical investigation of the OH-initiated atmospheric degradation mechanism of CX2CHX (X = H, F, Cl) by advanced quantum chemical and transition state theory methods.

Halogenated olefins are anthropogenic compounds with many industrial applications but at the same time raising many environmental and health concerns. Gas-phase electrophilic addition of the OH radical to the olefinic CC bond represents the primary sink for these chemicals in the atmosphere, with the degree and type of halogenation playing a significant role in their overall reactivity. In this work, we present a theoretical investigation of the reaction mechanisms and kinetics for the reactions between the OH radical and CH2CH2 (ethylene, ETH), CF2CHF (trifluoroethylene, TFE) and CCl2CHCl (trichloroethylene, TCE), simulated by state-of-the-art protocols and methods, with the aim of providing a detailed interpretation of the available experimental results, as well as new data of relevance to tropospheric chemistry. Specifically, potential energy surfaces (PESs) are obtained using the jun-Cheap (jChS) composite scheme, whereas temperature and pressure dependent rate coefficients and product distributions in the 100-600 K temperature range are calculated within the Rice-Ramsperger-Kassel-Marcus/master equation (RRKM/ME) framework. The rates for barrierless channels are obtained from variable reaction coordinate-variational transition state theory (VRC-VTST) combined with the two transition state model. While the reactions with ETH and TFE proceed mainly via the formation of addition adducts at P = 1 atm and T = 298 K, the dominant channel for TCE is the Cl-elimination reaction. Global rate constants for the two halogenated olefins, TFE and TCE, are found to be pressure-independent, contrary to the case of ETH. The computed rate constants, as well as their temperature and pressure dependence, are in remarkable agreement with the available experimental data, and they are used to derive atmospheric lifetimes (τ) for both TFE and TCE as a function of altitude (h) in the atmosphere, by taking into account variations in the rate coefficients (k (T, P)) and [OH] concentration.

Analysis of static Wilson line correlators from lattice QCD at finite temperature with T-matrix approach

The thermodynamic T-matrix approach is used to study Wilson line correlators (WLCs) for a static quark-antiquark pair in the quark-gluon plasma (QGP). Selfconsistent results that incorporate constraints from the QGP equation of state can approximately reproduce WLCs computed in 2+1-flavor lattice-QCD (lQCD), provided the input potential exhibits less screening than in previous studies. Utilizing the updated potential to calculate pertinent heavylight T-matrices we evaluate thermal relaxation rates of heavy quarks in the QGP. We find a more pronounced temperature dependence for low-momentum quarks than in our previous results (with larger screening), which turns into a weaker temperature dependence of the (temperature-scaled) spatial diffusion coefficient, in fair agreement with the most recent lQCD data.

Low thermal conductivity in a new mixed metal telluride Mn1.8(1)In0.8(1)Si2Te6.

The design of new complex mixed metal tellurides (containing low toxicity cations) with intrinsic ultralow thermal conductivity is of paramount importance in the field of thermoelectrics. Herein, we report the synthesis and characterization of polycrystalline and single crystals of a new mixed-metal quaternary telluride Mn1.8(1)In0.8(1)Si2Te6. The structural aspects and chemical formula of this phase at room temperature have been established using single crystal X-ray diffraction and EDX studies. The trigonal centrosymmetric (space group: P3̄1m) structure of the title phase has cell constants of a = b = 7.0483(7) Å and c = 7.1277(8) Å. The structure has three independent cationic sites, one mixed (In1/Mn1), one partially filled Mn2, and one Si1, which are bonded with Te1 atoms. Each metal atom (In and Mn) in the structure is octahedrally coordinated with six neighboring Te1 atoms. The structure also features dimers of Si atoms, and each Si atom is bonded to three Te1 atoms to form ethane-like Si2Te6 units. The optical absorption study of a polycrystalline Mn1.8In0.8Si2Te6 sample shows a narrow optical bandgap of 0.6(2) eV. Temperature-dependent resistivity and Seebeck coefficient studies confirmed the p-type semiconducting nature of the sample with high values of S (301 μV K-1 to 444 μV K-1). The total thermal conductivity (ktot) study of the polycrystalline sample shows a decreasing trend on heating with an extremely low value of 0.28 W m-1 K-1 at 773 K. Magnetic measurements indicate a glassy magnetic behavior for the sample below 8 K.

Global existence and exponential stability of planar magnetohydrodynamics with temperature-dependent transport coefficients

Global existence and exponential stability of planar magnetohydrodynamics with temperature-dependent transport coefficients

Generating Predictive Chemical Kinetic Models for Quaternary Ammonium Monomers Chemical Degradation in Anion Exchange Membrane

It is widely accepted that the high cost of Proton Exchange Membrane (PEM) fuel cells (FC) is a major inhibitor of the transition to extensive commercialization of hydrogen-fueled FCs. One known alternative to this technology is Anion Exchange Membrane (AEM), greatly reducing the need for precious metals, e.g., platinum, and allowing a wider choice of lower cost polymeric materials1. Although research in the field of AEM has greatly evolved recently, AEM-FCs still lack sufficient durability and cell longevity. The current major challenge revolves around the chemical and structural stability of polymers constructing the membrane, which undergo different degradation reactions under cell operating conditions. A widely investigated AEM monomer is Benzyl trimethylammonium (BTMA), a quaternary ammonium (QA) cation, in which the positively charged nitrogen atom enables the selective transfer of hydroxide ions through the membrane2. BTMA degradation occurs in several reaction paths, the main one involving a nucleophilic attack of the hydroxide at the benzylic carbon atom, resulting in complete displacement of the functional group (Fig. 1a). Recently, it has also been shown that low hydration levels of hydroxide, evidently more relevant to the FC’s environment, have an immense impact on the reduced stability of BTMA3,4. Despite the elaborate research done on BTMA degradation, as well as on other QA monomers, complete understanding of the chemical mechanisms affecting the stability of AEM-FCs is still lacking. Modeling these mechanisms can assist in facilitating practical implementation of this promising technology, discovering novel chemically-stable ionomers, while saving time and resources in trial-and-error efforts.The goal of this research is to develop an automated workflow for generating and refining predictive chemical kinetic models describing chemical degradation of AEM monomers, by combining several computational tools, and tailoring them to suit our specific needs. The first is the Reaction Mechanism Generator (RMG) software, which automatically generates chemical kinetic models by utilizing a basic comprehension of chemical reactions5. RMG derives its data from “libraries” of kinetic and thermodynamic parameters based on the literature, and from estimations schemes based on group or decision trees. Since RMG currently does not support ion chemistry, it is required to add this feature to the software, along with solvation corrections, while extending its estimation schemes. To achieve this, accurate kinetic and thermodynamic parameters of the species and reactions of interest are necessary.The present work focuses on describing BTMA degradation. Preliminary results for the temperature-dependent rate coefficient and thermodynamic properties were obtained using the Automated Rate Calculator (ARC) software6. This tool facilitates electronic structure calculations relevant for chemical kinetic modeling, by automatically spawning, tracking, and analyzing relevant computations. We computed the BTMA + OH– reaction rate coefficient at a low hydration level (λ=1) at the ωB97xD/Def2-TZVP level of theory, and compared it to the experimental results obtained at three different temperatures (Fig. 1b). The calculations were performed using the SMD solvation model with DMSO as the solvent, in accordance with the experimental conditions. Our preliminary results show some agreement with experimental measurements, and we expect this agreement to improve by calculating single-point energies using the more accurate coupled-cluster (CC) theory.The methods developed to generate a chemical kinetic model for BTMA, can then be applied for other potential QA monomers. Furthermore, an additional software called The Tandem Tool (T3), can be used to perform model refinement, through a process of iterations between RMG and ARC, creating the desired automated model generation workflow. This process is designed to obtain quantum mechanics-based calculated parameters for significant species and reactions in the model, chosen using sensitivity analysis. Altogether, this work can create a powerful tool, providing insights on known AEM ionomers, as well as the flexibility to investigate additional polymeric materials, with minimal experimental resources.

Assessing Climate Sensitivity and Mechanisms in a One-Dimensional Climate Energy Balance Model

Addressing the pressing concerns surrounding climate sensitivity, particularly within the context of Earth's changing climate, remains a pivotal endeavor. In this paper, the earth global temperature variation modeled by a one-dimensional climate energy balance model (EBM) is studied using a variance-based sensitivity analysis. The outcomes of this study offer a comprehensive analysis on each parameter that govern Earth's climate dynamics. Specifically, the analyses highlight that land albedo possesses the most substantial First-Order Sobol indices; the solar multiplier and the constant coefficient in the linearized Stefan-Boltzmann Law emerge as the second and third-largest contributor to Sobol indices, while the sensitivity of albedo of ice, temperature dependent coefficient of linearized Stefan-Boltzmann Law, and Transfer Coefficient remain insignificance. The analysis also suggests the non-negligible role of ice-albedo feedback and supports the hypothesis of the "Snowball Earth". This research holds significance as it uniquely addresses Earth's climate sensitivity using a one-dimensional Energy Balance Model, offering fundamental yet essential insights into the dynamics of earth's climate system, particularly its temperature variations.

The Soret coefficient of human low-density lipoprotein in solution: a thermophilic behavior.

Thermodiffusion, or Soret effect, is the physical phenomenon of matter gradients originated by the migration of chemical species induced by thermal gradients. Thermodiffusion has been widely applied in the study of colloidal suspensions. In this study, we investigate the termodiffusion behavior of low-density lipoprotein (LDL) particles, by the Soret coefficient measurement. It is a new approach to studies of plasma lipoproteins. The experimental work was based on thermal- and Soret-lens effects. These effects were induced by laser irradiation of the samples, at two different time scales, in a Z-scan setup. LDL samples were analyzed under physiological conditions, notedly, ionic strength and pH, and at different temperatures. Temperature dependence of Soret coefficient showed a slight decrease in the absolute value of this coefficient, as a function of temperature increasing. However, its sign does not change at the temperatures investigated (15, 22.5 and 37.5°C). The results show that LDL particles exhibit thermophilic behavior. The origin of this thermophilic behavior is not yet completely understood. We discuss some aspects that can be related with the Soret effect in LDL samples.

Numerical analysis of thermoelectric power generation coupled with temperature-dependent material properties

Thermoelectric generator (TEG) with improved performance is a promising technology in power supply and energy harvesting. Existing studies primarily adopt constant material properties to investigate TEG performance. However, thermoelectric (TE) material properties are subjected to considerable variations with temperature. Thus, reasonable doubts have risen concerning the influence level of temperature-dependent material properties on TEG performance. To solve this problem, an efficient and a comprehensive one-dimensional numerical model is developed to fully consider the third-order polynomial temperature-dependent thermal conductivity, Seebeck coefficient, and electrical resistivity. Control volume and finite difference algorithms are compared, and experiments are conducted to verify the developed numerical model. The temperature distribution along the TE leg obviously differs from the parabolic shape, which is a classic temperature distribution under the assumption of constant material properties. Insights find that the local change rate of thermal conductivity and Thomson effect are the essential reasons for the abovementioned phenomenon. It has been found that Thomson heat is released in the part of the leg near the cold-end, whereas it is absorbed in the remaining parts of the leg near the hot-end. The electric power on the basis of constant material properties is confirmed to be accurate enough by the developed numerical model, but the parabolic shape of the TE efficiency can be only obtained when temperature-dependent material properties are considered. Furthermore, it is wise to improve the TE efficiency by structural optimization. The present work provides an efficient and a comprehensive one-dimensional numerical model to include temperature-dependent material properties. New insights into the temperature and heat flux distribution, Thomson influence, and structural optimization potential are also presented for the in-depth understanding of the TE conversion process.

Temperature-Dependent Line-Broadening Effects in CO2 Caused by Ar.

This computational study of line-broadening effects is based on an accurate, analytical representation of the intermonomer potential energy surface (PES) of the CO2 ⋅ Ar van der Waals (vdW) complex. The PES is employed to compute collisional broadening coefficients for rovibrational lines of CO2 perturbed by Ar. The semiclassical computations are performed using the modified Robert-Bonamy approach, including real and imaginary terms, and the exact trajectory model. The lines investigated are in the 10001←00011, 01101←00001, 00011←00001, and 00031←00001 vibrational bands and the computations are repeated at multiple temperatures. The computed results are in good agreement with the available experimental values, validating both the intermonomer PES developed and the methodology used. For lines in the 01101←00001 band of CO2 , temperature-dependent Ar-broadening coefficients are reported for the first time. The parameters presented should prove useful, among other applications, for the accurate experimental determination of CO2 and Ar abundances in planetary atmospheres.

Modeling of CO Oxidation by Diffusion of Oxygen Atoms in Ceria-Zirconia Particulates in a Three-Way Catalyst Particle Membrane Filter

In order to design a microporous membrane filter comprising Three-way Catalyst (TWC) particles with a size distribution of 1 to 2 microns, isothermal CO oxidation experiments and numerical simulations were conducted to investigate the transport of oxygen atoms within primary Ceria-Zirconia (CZ) particulates. These spherical TWC particles were fabricated through the agglomeration of primary CZ and alumina particulates, incorporating Pd and Rh catalysts. By comparing experimental CO2 emissions with simulation results over time, a temperature-dependent diffusion coefficient was determined. The simulation results reveal that the effective distance of oxygen atom transport within CZ particulates, heterogeneously distributed in the spherical TWC particle, is limited to approximately 100 nm from the surface of agglomerated spherical TWC particles within a temperature range of 175 to 225°C.

Machine Learning Approach to Analyze the Heavy Quark Diffusion Coefficient in Relativistic Heavy Ion Collisions.

The diffusion coefficient of heavy quarks in a deconfined medium is examined in this research using a deep convolutional neural network (CNN) that is trained with data from relativistic heavy ion collisions involving heavy flavor hadrons. The CNN is trained using observables such as the nuclear modification factor RAA and the elliptic flow v2 of non-prompt J/ψ from the B-hadron decay in different centralities, where B meson evolutions are calculated using the Langevin equation and the instantaneous coalescence model. The CNN outputs the parameters, thereby characterizing the temperature and momentum dependence of the heavy quark diffusion coefficient. By inputting the experimental data of the non-prompt J/ψ(RAA,v2) from various collision centralities into multiple channels of a well-trained network, we derive the values of the diffusion coefficient parameters. Additionally, we evaluate the uncertainty in determining the diffusion coefficient by taking into account the uncertainties present in the experimental data (RAA,v2), which serve as inputs to the deep neural network.

Thermodynamic consideration of dissolution and distribution behavior of carvedilol in pharmaceutical significant media

The key physico-chemical properties for pharmaceutical design as solubility and distribution coefficients of cardiovascular carvedilol (CVD) in modeling solvents and biphasic systems were determined using the classic shake flask method in the temperature range (293.15–313.15) K. The drug solubility in 1-octanol and hexane was measured at first time. The equilibrium mole fraction solubility of CVD at reference temperature was changed in following order: 1-octanol (2.79∙10-3) > hexane (4.56∙10-6) > buffer pH 2.0 (3.39∙10-6) > buffer pH 7.4 (1.53∙10-7). Solubility pH-profile was characterized a weak solubility in acidic media and very poor solubility in neutral. The experimental lipophilic values logDO/B (1.83 and 2.36 at buffer solution pH 2.0 and 7.4, respectively) were shown the excellent penetration power into both the circulatory system and the entire intestinal tract. The temperature dependences of the CVD distribution coefficients in 1-octanol/buffer and hexane/buffer two-phase systems at pH two values (2.0 and 7.4) were considered from the thermodynamic view point. Thermodynamic functions of solubility and transfer processes were calculated and analyzed. Thermophysical parameters of the compound were used for estimation of the ideal solubility and activity coefficients. Moreover partial excess thermodynamic functions of CVD dissolution in saturated solutions, demonstrating the positive deviation real solvents from ideality, are also evaluated in detail. The data obtained will be in demand both for the creation of conceptually new dosage forms of carvedilol with improved bioavailability, and for constructing structure–property correlations in a number of structure-like compounds.