Analysis Of Mass Transfer Phenomena Research Articles

Moment analysis method for determination of rate constants of solute permeation across interface of spherical molecular aggregates by means of high-performance liquid chromatography

A moment analysis method was developed for the study of solute permeation at the interface of spherical molecular aggregates. At first, new moment equations were developed for determining the partition equilibrium constant (Kp) and permeation rate constants (kin and kout) of solutes from the first absolute (μ1A) and second central (μ2C) moments of elution peaks measured by using high-performance liquid chromatography (HPLC). Then, the method was applied to the analysis of mass transfer phenomena of three solutes, i.e., hydroquinone, resorcinol, and catechol, at the interface of sodium dodecylsulfate (SDS) micelles. HPLC data were measured by using an ODS column and an aqueous phosphate buffer solution (pH = 7.0) as the mobile phase solvent. Pulse response experiments were conducted while changing SDS concentration (5 - 20 mmol dm−3) in the mobile phase under the conditions that the surface of ODS stationary phase was dynamically coated by SDS monomers. In order to demonstrate the effectiveness of the moment analysis method using HPLC, the values of Kp, kin, and kout were determined for the three solutes as 35 - 69, 2.4 × 10−8 - 1.4 × 10−6 m s−1, and 7.0 × 10−10 - 2.1 × 10−8 m s−1, respectively. Their values increase with an increase in the hydrophobicity of the solutes. The method has some advantages for the study of interfacial solute permeation of molecular aggregates. For example, neither immobilization nor chemical modification of both solute molecules and molecular aggregates is required when elution peaks are measured by using HPLC. Interfacial solute permeation takes place in the mobile phase without any chemical reaction or physical action on molecular aggregates. The values of Kp, kin, and kout were analytically determined from those of μ1A and μ2C by using the moment equations. The results of this study must contribute to the dissemination of an opportunity for studying the interfacial solute permeation of molecular aggregates to many researchers because of extremely high versatility of HPLC.

A mathematical analysis of mass transfer phenomena with chemical reaction over the flow of Sisko ferronanofluid across a permeable surface

Mathematically study mass transfer phenomena involving chemical reactions in the flow of Sisko Ferro nanofluids through the porous surface. Three ferronano particles, manganese-zinc ferrite (Mn1/2Zn1/2Fe2O4), cobalt ferrite (CoFe2O4), and nickel–zinc ferrite (Ni–Zn Fe2O4) are considered with water (H2O) and ethylene glycol (C2H6O2) as base liquids. Appropriate resemblance transitions are used to convert the governing system of a nonlinear PDE to a linear ODE. The Runge–Kutta method, as extended by the shooting technique, is used to accomplish the reduction governing equations. The effects of various associated parameters on fluid concentration and mass transfer rate are investigated: magnetic criterion (M), Siskofluid material factor (A), Solid volume fraction (ϕ) for nanofluids, permeability parameter (Rp), Chemical reaction criterion (γ), Brownian motion factor (Nb), and Thermophoretic parameters (Nt). The current findings indicate that the diffusion proportion of Sisko Ferronanofluid Ni–Zn Fe2O4–H2O and CoFe2O4–H2O is higher than that of Ni–Zn Fe2O4–C2H6O2 and CoFe2O4–C2H6O2 respectively but it is opposite in the case of Mn–Zn ferrite. The comparison study was carried out to validate the precision of the findings.

Analysis of mass-transfer phenomena in the dendritic net of solidifying steel ingots. 2. Convective diffusion of the impurity in the dendritic net of solidifying ingots

An analysis of the interaction of the melt flow with the surface of dendritic crystallites has been performed using the concept of a diffusion boundary layer, and the regularities of the impurity distribution over the cross section of ingots and castings in the process of their solidification have been revealed.

Analysis of mass-transfer phenomena in the dendritic net of solidifying steel ingots. 1. Formulation of the problem. Analysis of melt flow in the dendritic net

Based on the solution of the problem of mass transfer in a dendritic net, an analysis of the motion of a melt in the interdendritic space and of mass-transfer phenomena in the moving melt has been performed with the aim of determining the growth in the concentration of a soluble impurity in the axial zone of solidifying continuous castings.

Heat transfer in polymer composites containing thermally active fillers: Mathematical modeling

AbstractThe heat transfer data recently presented by Migliaresi, et al. are used as the basis for developing two models of the coupled heat transfer‐phase transition phenomena in polymeric composites containing thermally active fillers. Both models represent an extension to heat transfer of ideas which have originated in the analysis of mass transfer phenomena in polymeric materials. The second model is able to correlate all the available data within 0.5°C.