Diffusion, Flow and Velocity Imaging

1 Diffusion. - Distribution of the diffusivitity of fluid in a horizontally oriented cylinder was demonstrated by NMR imaging in two papers on a granular flow system and in the earth s magnetic field. Correlation time (ic) and diffusion coefficient (D = u Xc) imaging (CTDCI) was applied to a granular flow system of 2 mm oil-filled sphere rotated in a half-filled horizontal cylinder, ie. to an Omstein-Uhlenbeck process with a velocity autocorrelation function. Time dependent apparent diffusion coefficients are measured, and Tc 

Molecular motion in the polar organic solvent nitrobenzene, induced by both continuous and pulsed electronic fields, was studied by magnetic resonance imaging. The resultant image correlation spectra indicate that the time scale of motion in a 9.6 kV cm electric field is tens of milliseconds. The data were analyzed by the Fokker-Planck probability function for one-dimensional bounded diffusion. 

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