a novel computational fluid dynamics and molecular kinetic theory (cfd-mk) method was developed to simulate the impingement of a nanodroplet onto a solid surface. a numerical solution of the navier–stokes equation using a volume-of-fluid (vof) technique was used to model nanodroplet deformation. dynamic contact angle during droplet impact was obtained by molecular kinetic theory. this dynamic c...

the numerical method presented by safaiy et al. [1] is reformulated with finite volume method in its most general form and tested on non-orthogonal flow problems. navier-stokes equations are solved for the solution of stream function and vorticity. numerical solutions of the driven skewed cavity flow, solved using a fine grid (513×513) mesh, are presented for reynolds number of 100 and 1000 for...

a method based on the ultrasound-assisted solidification of floating drop microextraction technique was developed for the spectrophotometric and spectrofluorimetric determination of curcumin in turmeric powder. in this work a small volume of an organic solvent was floated on the surface of an aqueous solution. after sonication the organic solvent is solidified and separated. the effect of extra...

In the paper, in order to pre-concentrate and measure the low values of Cu ions, the new, simple,quick and very sensitive method of Dispersed Liquid-Liquid Micro Extraction (DLLME) coupledwith flame Atomic Absorption spectrometry (AA) has been utilized. The DLLME techniquecoupled with AA )AA-DLLME) was run inside one narrow tube which constitute aqueous samples.In this m...

in this paper, the possibility of using a new ordered nanoporous carbon as a new fiber in headspace solid phase microextraction (hs-spme) to determine of mononitrotoluenes (mnts) in waste water is demonstrated. the structural order and textural properties of the ordered nanoporous carbon were studied by x ray diffraction (xrd), scanning electron microscopy (sem) images and nitrogen adsorption i...

Barium sulfate (barite) is one of the widely used weighting materials in the preparation of drilling fluid for deep oil and gas wells. Barite is not soluble in the regular solvents; such as, hydrochloric acid (HCl) and other acids. Therefore, in this study, we focused on evaluating the dissolution of the industrial barite particles in different chelating agents. Chelating agents; such as, dieth...

In this paper a new macroscopic k-ε model is developed and validated for turbulent flow through porous media for a wide range of porosities. The morphology of porous media is simulated by a periodic array of square cylinders. In the first step, calculations based on microscopic v2 − f model are conducted using a Galerkin/Least-Squares finite element formulation, employing equalorder bilinear ve...

In this paper a novel numerical approach is presented for solving the transient incompressible fluid flow problems with free surfaces in generalized two-dimensional curvilinear coordinate systems. Solution algorithm is a combination of implicit real-time steps and explicit pseudo-time steps. Governing fluid flow equations are discretized using a collocated finite-volume mesh. Convective terms a...

We study a colloidal suspension confined between two quasiparallel walls as a model system for glass transitions in confined geometries. The suspension is a mixture of two particle sizes to prevent wall-induced crystallization. We use confocal microscopy to directly observe the motion of colloidal particles. This motion is slower in confinement, thus producing glassy behavior in a sample which ...