The effect of pore surface roughness on Knudsen diffusion in nanoporous media is investigated by dynamic Monte-Carlo simulations and analytical calculations. A conceptual difference is found between the roughness dependence of the macroscopic, transport diffusivity and the microscopic, selfdiffusivity, which is reminiscent of diffusion in zeolites, where a similar difference arises due to adsor...

Dissolved water is known to dramatically enhance oxygen diffusion in silicate melts, glasses and minerals. A quantitative theory has been developed to explain this phenomenon by transport via molecular H2O diffusion [Y. Zhang, E.M. Stolper, G.J. Wasserburg, Diffusion of a multi-species component and its role in the diffusion of water and oxygen in silicates, Earth Planet. Sci. Lett., 103 (1991)...

We investigate the question of whether ambipolar diffusion (ion-neutral drift) determines the smallest length and mass scale on which structure forms in a turbulent molecular cloud. We simulate magnetized turbulence in a mostly neutral, uniformly driven, turbulent medium, using a three-dimensional, two-fluid, magnetohydrodynamics (MHD) code modified from Zeus-MP. We find that substantial struct...

Inspired by ideas from NMR, we have developed Infrared Diffusion-Ordered Spectroscopy (IR-DOSY), which simultaneously characterizes molecular structure and size. We rely on the fact that diffusion coefficient of a molecule is determined its size through Stokes-Einstein relation, achieve sensitivity to creating concentration gradient tracking equilibration in an IR-frequency resolved manner. Ana...

in this paper, the role of molecular diffusion in mobilization of waterflood residual oil is examined. a moving mesh method is applied to solve the moving interface problem of residual oil blobs swelling by co2 diffusion through a blocking water phase. the results of this modeling are compared with experimental results of a 2d glass micromodel experiment. although, the solution method is applie...

Two multiscale (hybrid) stochastic reaction-diffusion models of actin dynamics in a filopodium are investigated. Both hybrid algorithms combine compartment-based and molecular-based stochastic reaction-diffusion models. The first hybrid model is based on the models previously developed in the literature. The second hybrid model is based on the application of a recently developed two-regime meth...