When a temperature gradient is applied to a polymer solution, the polymer typically migrates to the colder regions of the fluid as a result of thermal diffusion ~Soret effect!. However, in recent thermodiffusion experiments on poly~ethylene-oxide! ~PEO! in a mixed ethanol/water solvent it is observed that for some solvent compositions the polymer migrates to the cold side, while for other compo...

In this paper, a simplified model of an incompressible fluid flow along with heat and mass transfer past a porous flat plate embedded in a Darcy type porous medium is investigated. The velocity, thermal and mass slip conditions are utilized that has not been discussed in the literature before. The similarity transformations are used to transform the governing partial differential equations (PDE...

We investigate how a horizontal plane Poiseuille shear flow changes linear convection properties in binary fluid layers heated from below. The full linear field equations are solved with a shooting method for realistic top and bottom boundary conditions. Relevant characteristic growth exponents and the spatial structure of their associated eigenfunctions are evaluated for different perturbation...

Thermal diffusion forced Rayleigh scattering measurements on binary mixtures of carbon tetrabromide (CBr(4)), tetraethylsilane, and di-tert-butylsilane in carbon tetrachloride (CCl(4)) are reported at different temperatures and concentrations. The Soret coefficient of CBr(4) in CCl(4) is positive and S(T) of both silanes in CCl(4) is negative, which implies that the heavier component always mov...

A theoretical analysis of linear and non-linear (two-photon absorption) electronic spectroscopy of all known porphyrinic pigments has been performed using linear and quadratic density functional response theory, with the long-range corrected CAM-B3LYP functional. We found that higher Soret transitions often contain non-Gouterman contributions and that each chlorophyll has the possibility for re...

Thermophoresis, also termed thermal diffusion or the Soret effect, moves particles along temperature gradients. For particles in liquids, the effect lacks a theoretical explanation. We present experimental results at moderate thermal gradients: (i) Thermophoretic depletion of 200 nm polystyrene spheres in water follows an exponential distribution over 2 orders of magnitude in concentration; (ii...

The aim of this paper is to study the impact of Soret and Sherwood number on stretching sheet in presence of magnetic field in a porous medium. Using stream function, partial differential equations corresponding to the momentum energy and mass transfer are converted into non-linear coupled ordinary differential equations. Approximate solutions of these equations are obtained by using Homotopy a...

We have computed the Soret coefficient in aqueous mixtures using a boundary driven nonequilibrium molecular dynamics algorithm and standard molecular force fields. The choice of this specific approach is justified by the nature of the mixtures studied here. Four aqueous solutions, including methanol, ethanol, acetone, and dimethyl-sulfoxide (DMSO) have been studied at ambient conditions for dif...

The current study used a novel Casson model to investigate hybrid Al2O3-Cu/Ethylene glycol nanofluid flow over moving thin needle under MHD, Dufour–Soret effects, and thermal radiation. By utilizing the appropriate transformations, governing partial differential equations are transformed into ordinary equations. solved analytically using HAM. Furthermore, we discuss velocity profiles, temperatu...