The effect of drainage front morphology on gaseous diffusion through partially saturated porous media is analyzed using the lattice Boltzmann method (LBM). Flow regimes for immiscible displacement in porous media have been characterized as stable displacement, capillary fingering, and viscous fingering. The dominance of a flow regime is associated with the relative magnitudes of gravity, viscou...

Microfluidic devices with a dual function containing both a solid-phase extractor and an enzymatic microreactor have been prepared, and their operation has been demonstrated. The devices were fabricated from a 25-mm-long porous poly(butyl methacrylate-co-ethylene dimethacrylate) monolith prepared within a 50-microm-i.d. capillary. This capillary with a pulled 9-12-microm needle tip was used as ...

A technique for the in-process measurement of polymer stationary phase growth inside fused silica capillaries during the fabrication of monolithic porous layer open tubular (monoPLOT) columns is presented. In this work, capacitively coupled contactless conductivity detection (C4D) was applied as an online measurement tool for porous polymer layer growth within fused silica capillaries. The rela...

A 3D lattice Boltzmann model is developed and used to calculate the water and gas permeabilities of model cement pastes at different degrees of water saturation. In addition to permeable micron-sized capillary pores and impermeable solid inclusions, the lattice Boltzmann model comprises weakly-permeable nano-porous calcium silicate hydrate (C-S-H). The multi-scale problem is addressed by using ...

This paper deals with the reflection and transmission of elastic waves from imperfect interface separating a micropolar elastic solid half-space and a fluid saturated porous solid half-space. Longitudinal and transverse waves impinge obliquely at the interface. Amplitude ratios of various reflected and transmitted waves are obtained and computed numerically for a specific model and results obta...

the esterification of free fatty acids (ffa) with methanol is studied using sulfonated porous carbon (spc) as catalyst. in compare to the amorphous sugar catalyst and protonated nafion, the proposed catalyst shows stability and high efficient performance in biodiesel production. the highest initial rate of oleic acid conversion is obtained at catalyst loading of 1 mmol h+ and mole ratio of meoh...

Pigmented coatings, used to improve optical and printing properties, are applied to fibrous paper substrates as slurry, which then dries. We have elucidated the mechanism of the shrinkage which occurs during drying. The void space of the dry coating layers and their effective solid skeletal elements were modelled using the porous network simulation software Pore-Cor. The water-filled porous str...

We discuss the problem of trapping and mobilization of nonwetting fluids during immiscible two-phase displacement processes in porous media. Capillary desaturation curves give residual saturations as a function of capillary number. Interpreting capillary numbers as the ratio of viscous to capillary forces the breakpoint in experimental curves contradicts the theoretically predicted force balanc...

Abstract The aim of this work is to design a high-productivity, continuously operating fiber producing device utilizing the centrifugal force yield polymeric nanofibers. requirements for were 1) provide capillary-to-collector distance 50–200 mm that could be adjusted automatically, 2) allow rotational speed spinneret changed in range 0–25000 1/min and have continuous feeding. equipment will for...