in this work, the precipitation and re-dissolution of asphaltenes were studied for an iranian relatively heavy crude oil. a series of experiments were designed and carried out to quantitatively examine the reversibility of asphaltenes precipitation upon the change in the solvent concentration along with the temperature. n-heptane was used as the precipitant, and a temperature range of 30 to 70°...

The Soret–driven ferro thermoconvective instability of multi–component fluid in a porous medium heated from below and salted from above in the presence of dust particles subjected to a transverse uniform magnetic field has been analyzed using Darcy model for various values of permeability of the porous medium. The salinity effect has been contained in magnetization and density of the ferrofluid...

For a two-phase swelling porous medium, two pressures have been previously defined thermodynamically in terms of intensive variables for each phase: one relating the change in energy with respect to specific volume, and the other relating the change in energy with respect to volume fraction. Within the framework of Hybrid Mixture Theory and hence the Coleman and Noll technique of exploiting the...

General e ective-stress rules are derived for various physical properties of inhomogeneous porous rocks. Some rigorous relations arising in the analysis show that the uid (pore) pressure pf is least e ective at counteracting the changes caused by con ning pressure for the solid (grain) volume; pf is more e ective for the total (solid plus pore) volume; pf is still more e ective for the pore vol...

We describe the imbibition process from a point source into a homogeneous semi-infinite porous material. When body forces are negligible, the advance of the wetting front is driven by capillary pressure and resisted by viscous forces. With the assumption that the wetting front assumes a hemispherical shape, our analytical results show that the absorbed volume flow rate is approximately constant...

Speckle correlation diagnostics was used to study non-stationary multiple scattering multi-phase systems with spatially separated components on the instance of porous media in the course of liquid-phase evaporation. We propose a phenomenological model in which the local interfaces between air-filled and liquid-filled spaces in the probed medium act as an ensemble of the elementary dynamic scatt...

a numerical study of 3d electrokinetic flows through micromixers was performed. the micromixers considered here consisted of heterogeneous rectangular microchannels with prescribed patterns of zeta-potential at their walls. numerical simulation of electroosmotic flows within heterogeneous channels requires solution of the navier-stokes, ernest-plank and species concentration equations. it is kn...