An improved model of mud dispersion has been introduced in this work. The advantages of this model consist of a new analytical correlation for dispersivity by using resistivity log data and using a new aspect of capacitance dispersion model. Mathematical formulations were expressed, solved by numerical model taking advantage of actual log and formation data. Achieved results yielded r...

The objective is estimated the concentration of air pollution, by solving the atmospheric diffusion equation (ADE) using Adomain decomposition method. The solution depends on eddy diffusivity profile (K) and wind speed at the released point (u). We solve the ADE numerically in two dimensions using Adomain decomposition method, then, compared our results with observed data.

A new formulation for eddy diffusivity is derived from Taylor’s statistical theory on turbulence and from a generalized turbulent spectral equation for energy in the inertial subrange. The latter aspect is taken into account for considering the intermittency phenomenon within turbulence model. The approach is used for a stable atmospheric boundary layer parameterization. r 2005 Elsevier B.V. Al...

This study was concerned about an estimation of molecular diffusivity (D(m)) in liquid phase systems. An equation based on the absolute rate theory of diffusion was derived by considering the aggregation of not only solvent molecules, but also solute molecules. It was also studied how the replacement of the molar volume of a solvent with its molecular weight influences the accuracy in estimatin...

The concept of a protein diffusing in its free-energy folding landscape has been fruitful for both theory and experiment. Yet the choice of the reaction coordinate (RC) introduces an undesirable degree of arbitrariness into the problem. We analyze extensive simulation data of an alpha-helix in explicit water solvent as it stochastically folds and unfolds. The free-energy profiles for different ...

We consider the drift-diffusion equation ut???u+??(u?K?u)=0 in whole space with global-in-time bounded solutions. Mass concentration phenomena for radially symmetric solutions of this small diffusivity are studied.

We present a straightforward method to solve gas damping problems for perforated structures in two dimensions (2D) utilising a Perforation Profile Reynolds (PPR) solver. The PPR equation is an extended Reynolds equation that includes additional terms modelling the leakage flow through the perforations, and variable diffusivity and compressibility profiles. The solution method consists of two ph...

In this work, we combine our earlier proposed empirical potential based quasi-continuum theory, (EQT) [A. V. Raghunathan, J. H. Park, and N. R. Aluru, J. Chem. Phys. 127, 174701 (2007)], which is a coarse-grained multiscale framework to predict the static structure of confined fluids, with a phenomenological Langevin equation to simulate the dynamics of confined fluids in thermal equilibrium. A...

The magnetic Reynolds number RM , is defined as the product of a characteristic scale and associated flow speed divided by the microphysical magnetic diffusivity. For laminar flows, RM also approximates the ratio of advective to dissipative terms in the total magnetic energy equation, but for turbulent flows this latter ratio depends on the energy spectra and approaches unity in a steady state....