Partial Viscosity Research Articles

The impact of thermophysical properties on eflornithine drug solute in acetone and ethyl acetate solvent interactions at varying concentrations and temperatures

The study was conducted on the impact of thermophysical properties on eflornithine drug solute–solvent interactions in aqueous ethyl acetate and acetone at different concentrations and temperatures. The aim of this study is to enhance the understanding of eflornithine’s behavior in different solvents, which is crucial for its effective use in pharmaceutical applications. The density, molar volume, viscometric, and conductometric characteristics of the eflornithine drug solutions (0.025, 0.05, 0.075, 0.1, and 0.125 mol/kg) in acetone and 25% (v/v) aqueous ethyl acetate were measured within a temperature range of 298.15 K–318.15 K. Based on the determined density parameters, the following parameters were assessed: viscosity (η), equivalent molar conductance, limiting apparent molar volume (V0φ), apparent molar volume of transfer (V0φtr), and apparent molar volume (Vφ). The Masson empirical relationship and the viscosity-to-Jones-Dole (JD) equation were used to evaluate the partial molar volume (Vφ), experimental slope (SV), viscosity, and density data. Temperature and concentration were used to determine each parameter. For each set of dilutions, conductometric studies were conducted in both study solvents. The gathered data was analyzed in order to evaluate the ion–solvent interactions. The Walden product Λomηo’s positive temperature coefficient values indicate that the drug eflornithine functions as a structural modifier in acetone and aqueous acetyl acetate systems. The structure-making and breaking characteristics of the polar solvents acetone and ethyl acetate were identified.

Stability and decay estimates of the 2D incompressible magneto-micropolar fluid system with partial viscosity on a flat strip

Stability and decay estimates of the 2D incompressible magneto-micropolar fluid system with partial viscosity on a flat strip

Excess properties, spectral analyses, and CO2 capture performance of N-methyldiethanolamine + polyethylene glycol 300 binary system

Density (ρ) and viscosity (η) data of polyethylene glycol 300 (PEG300) + N-methyldiethanolamine (MDEA) binary system at T = (298.15–318.15) K with a step of 5 K were measured at P = 1005 hPa. After that, the experimental ρ and η values were correlated and predicted by several semi-empirical models. Meanwhile, the Jouyban-Acree model presented a better fitting for the density, and the McAllister four-body equation presented a better fitting for the kinematic viscosity. Based on the ρ and η values, excess molar volume (VmE), partial molar volume (V1¯ and V2¯), viscosity deviation (Δη), and excess Gibbs energy of activation of viscous flow (ΔG∗E) of PEG300 (1) + MDEA (2) binary system were systematically calculated and analyzed. These excess properties showed the predominance of intermolecular self-conjugation in PEG300 (1) + MDEA (2) binary system, and it was further demonstrated by various spectral characterizations. Importantly, the PEG300 + MDEA aqueous system was used for 5 CO2 absorption (room temperature)-desorption (371.15 K) cycles at a CO2 flow rate of 200 mL/min, with the average CO2 capture performance of 0.65 mol CO2/mol MDEA of per cycle, demonstrating excellent absorption capability, and remained stable throughout the entire cycle.

Volumetric and viscometric properties of aqueous choline chloride + methyldiethanolamine deep eutectic solvents

Amine-based deep eutectic solvents have the advantages of easy preparation, extremely low vapor pressure, stable biodegradation and high CO2 loading, which has become the most potential CO2 absorbent. In this work, the amine-based functionalized DES of choline chloride + methyldiethanolamine with different molar ratios were successfully prepared, and the densities and viscosities of DES aqueous solutions were measured from 303.15 K to 333.15 K. The effects of DES composition, water content and temperature on the excess molar volume, partial molar volume, apparent molar volume, limiting partial molar volume and viscosity deviation were investigated. The hydration and intermolecular interaction in DES solution were analyzed. The critical concentration of water in solution was determined under the premise of maintaining DES hydrogen bond network.

Effect of water or ethanol on the excess properties of deep eutectic solvents (tetrabutylammonium bromide + formic acid/propionic acid)

The density and viscosity of binary mixtures of [tetrabutylammonium bromide + formic acid/propionic acid] with water or ethanol were determined in the entire molar fraction range of 288.15–318.15 K. The influences of temperature, deep eutectic solvents (DESs) composition and molar fraction, as well as different solvents on the excess molar volume, apparent molar volume, partial molar volume, viscosity deviation and excess viscous flow activation Gibbs free energy of the binary mixed system were investigated in detail. The interaction of DESs with solvent molecules in binary system mixtures is discussed. It demonstrated the existence of hydrogen bonding between DESs and solvent molecules, and that the interaction between DESs and ethanol was stronger than DESs-water. By introducing the concepts of relative volume and relative viscosity, the viscosity values of the binary mixed system were predicted by combining the Redlich-Kister equation. This study is expected to provide a theoretical reference for the future application of DESs.

Stability and large time decay for the three-dimensional magneto-micropolar equations with mixed partial viscosity

Stability and large time decay for the three-dimensional magneto-micropolar equations with mixed partial viscosity

Global Regularity of 2D Incompressible Magneto-Micropolar Fluid Equations with Partial Viscosity

Global Regularity of 2D Incompressible Magneto-Micropolar Fluid Equations with Partial Viscosity

Stability and large‐time behavior of the 3D Boussinesq equations with mixed partial kinematic viscosity and thermal diffusivity near one equilibrium

In this paper, we study the stability problem and large‐time behavior for the 3D Boussinesq equations with mixed partial kinematic viscosity and thermal diffusivity near one equilibrium, i.e., with (where is chosen to be large, e.g., satisfying the well‐known Miles‐Howard criterion). These problems can be extremely difficult due to the equations lack of full dissipation. Our results are twofold. In the first place, we establish the global and stability for the nonlinear system with seven different partially dissipated systems of Boussinesq equations. In the second place, we derive precise large‐time behavior for the linearized system.

Global regularity for 2D Boussinesq equations with partial viscosity in the half plane

In this paper, we study the initial‐boundary value problem of two‐dimensional Boussinesq equations with either zero viscosity or zero thermal dissipation in the half plane . We show the global regularity for these two cases with initial data and corresponding boundary conditions, based on the existence of global weak solutions. Our result can be regarded as a complement to the works of Chae in 2006, Lai, Pan and Zhao in 2011, and Zhao in 2010.

Impact of [formula omitted] on the thermophysical and FTIR properties of protein model compounds in aqueous solutions

Ionic liquids (ILs) have gained popularity in recent years due to their wide range of applications in chemical synthesis. They can be used in advancing technologies such as protein solubilization, increased protein activity, biocatalysis replication, and enzyme stability. Because of this, ILs can shed light on the ability of proteins to maintain stability. The present paper outlines the impact of IL on the thermophysical and FTIR properties of specific protein model compounds in aqueous solutions. Thus, densities ρand viscosities ηof some protein model compounds in aqueous solutions of ionic liquid, 1-butyl-3-methylimidazolium chloride, BMImCl, at various temperatures have been carried out at atmospheric pressure. These studies are aimed at gaining new insights into the ability of biomolecules to interact with IL, which is critical for understanding protein behaviour in solutions.Various parameters such as apparent molar volumes (V∅), partial molar volumes (V2O), viscosity B-coefficients, temperature coefficients (dB/dT), transfer parameters, i.e.,ΔtrV2o and ΔtrB, interaction parameters,YAB and YABB, hydration number i.e.nH and Nh, partial molar expansibilities ∂V2O/∂TP, their second-order derivatives ∂2V2O/∂T2P, and isobaric thermal expansion coefficients (αIL) have been calculated from density and viscosity data. In aqueous BMImCl, partial molar expansibilities and temperature coefficients are used to predict the structure maker/breaker behaviour of amino acids. Volume transfer values indicate the dominance of ionic-hydrophilic interactions. Thermodynamic parameters suggest that the formation of the transition state is less favoured in the presence of BMImCl solutions. Also, the effects of the hydrophilic ionic liquid, 1-butyl-3-methylimidazolium chloride,BMImCl on the ion-hydrophilic, hydrophobic-hydrophilic, and hydrophobic-hydrophobic interactions present in ternary systems, as well as the effects of temperature and alkyl chain length, have been discussed. FTIR spectra were measured to analyze the structural changes that occurred in the system. The current work provides some important fundamental experimental data and theoretical support for further exploring the interactions of various amino acids with ILs.

Global well-posedness for the 2D micropolar Bénard convection system with mixed partial viscosity

The micropolar Bénard system is derived from the convective motions in a heated and incompressible fluid. When there is only partial dissipation or no dissipation at all, the problem of whether the 2D micropolar Bénard convection system possesses a global classical solution is difficult to be solved. In this paper, we study the Cauchy problem of the two-dimensional micropolar Bénard problem with mixed partial viscosity. More precisely, the global regularity and some conditional regularity of strong solutions are obtained for 2D micropolar Bénard problem with mixed partial viscosity.

Well-posedness of the 3D Boussinesq-MHD equations with partial viscosity and damping

The three-dimensional Boussinesq-MHD equations with partial viscosity and damping are investigated in this paper. Existence and uniqueness of a global solution of the three-dimensional Boussinesq-MHD equations with partial viscosity and damping are proved for β≥4.

Global Existence and Time-decay Rates of Solutions to 2D Magneto-micropolar Fluid Equations with Partial Viscosity

Global Existence and Time-decay Rates of Solutions to 2D Magneto-micropolar Fluid Equations with Partial Viscosity

Regularity criterion for the 3D Boussinesq equations with partial viscous terms in the limiting cases

By means of Fourier analysis and the structure of the equation, for the 3D Boussinesq system with partial viscosity, we show the blow-up criterion of the smooth solution via a Beale–Kato–Majda type of supj∈Z∫0T‖Δ̇j∇×u‖∞dt and a Serrin type of ‖u‖C([0,T),B∞,∞−1) or especially its oscillation in the B∞,∞−1 norm with small amplitude.

Thermophysical and conductometric study of lithium perchlorate in binary aqueous mixture of polyethylene glycol (PEG-400)

In the present study apparent molar volume, partial molar volume, viscosity and conductance parameters of lithium perchlorate (LiClO4) in 0.01m, 0.03m and 0.05m aqueous polyethylene glycol (PEG-400) have been determined by using density, viscosity and conductance data at five equidistant temperatures 298.15K, 303.15K, 308.15K, 313.15K and 318.15K. Data is analysed in terms of various molecular interactions by using Masson’s and Jones-Dole equations. The structure making/breaking behaviour of LiClO4 is interpreted from 2 the sign of [∂2 ϕv°/∂T2], dB/dT and temperature coefficient of Walden product i.e., d(Λm°η°)/dT values. In the present study LiClO4 has been found as structure-maker in 0.01 m, 0.03m and 0.05m aqueous polyethylene glycol (PEG-400).

Total and Partial Shear Viscosity in Heavy-Ion Collisions at Energies of BES, FAIR and NICA

We calculated the shear viscosity of hot and dense nuclear matter produced in a symmetric system of central gold–gold collisions at energies of BES RHIC, FAIR and NICA. For calculations of the collisions, the transport model UrQMD was employed. The shear viscosity was obtained within the Green–Kubo formalism. The hadron resonance gas model was used to determine temperature and chemical potentials of baryon charge and strangeness out of microscopic model calculations. In contrast to our previous works, we determined the partial viscosity of the main hadron species, such as nucleons, pions, kaons and Lambdas, via the nucleon–nucleon, pion–pion and so forth, correlators. A decrease in the beam energy from Elab=40 to 10 AGeV leads a to rise in baryon shear viscosity accompanied by a drop in the shear viscosity of mesons. The ratio of total shear viscosity to entropy density also decreases.

Remarks on Liouville-Type Theorems for the Steady MHD and Hall-MHD Equations

In this note we investigate Liouville type theorems for the steady three dimensional MHD and Hall-MHD equations, and show that the velocity field $u$ and the magnetic field $B$ are vanishing provided that $B\in L^{6,\infty}(\mathbb{R}^3)$ and $u\in BMO^{-1}(\mathbb{R}^3)$, which state that the velocity field plays an important role. Moreover, the similar result holds in the case of partial viscosity or diffusivity for the three dimensional MHD equations.

Effects of Plasma Treated Alumina Nanoparticles on Breakdown Strength, Partial Discharge Resistance, and Thermophysical Properties of Mineral Oil-Based Nanofluids.

Mineral oil has been chosen as an insulating liquid in power transformers due to its superior characteristics, such as being an effective insulation medium and a great cooling agent. Meanwhile, the performance of mineral oil as an insulation liquid can be further enhanced by dispersing nanoparticles into the mineral oil, and this composition is called nanofluids. However, the incorporation of nanoparticles into the mineral oil conventionally causes the nanoparticles to agglomerate and settle as sediment in the base fluid, thereby limiting the improvement of the insulation properties. In addition, limited studies have been reported for the transformer oil as a base fluid using Aluminum Oxide (Al2O3) as nanoparticles. Hence, this paper reported an experimental study to investigate the significant role of cold plasma treatment in modifying and treating the surface of nano-alumina to obtain a better interaction between the nano-alumina and the base fluid, consequently improving the insulation characteristics such as breakdown voltage, partial discharge characteristics, thermal conductivity, and viscosity of the nanofluids. The plasma treatment process was conducted on the surface of nano-alumina under atmospheric pressure plasma by using the dielectric barrier discharge concept. The breakdown strength and partial discharge characteristics of the nanofluids were measured according to IEC 60156 and IEC 60270 standards, respectively. In contrast, the viscosity and thermal conductivity of the nanofluids were determined using Brookfield DV-II + Pro Automated viscometer and Decagon KD2-Pro conductivity meter, respectively. The results indicate that the 0.1 wt% of plasma-treated alumina nanofluids has shown the most comprehensive improvements in electrical properties, dispersion stability, and thermal properties. Therefore, the plasma treatment has improved the nanoparticles dispersion and stability in nanofluids by providing stronger interactions between the mineral oil and the nanoparticles.

Global Existence of Smooth Solutions to Three Dimensional Hall-MHD System with Mixed Partial Viscosity

Global Existence of Smooth Solutions to Three Dimensional Hall-MHD System with Mixed Partial Viscosity

Global classical large solutions to the 2D liquid crystal flows with partial viscosity

In this paper, we investigate the initial value problem for the two dimensional liquid crystal flows with partial viscosity. Global classical large solutions are proved by using the energy estimate, the anisotropic type Sobolev inequality and the tricky interpolation techniques.