Dynamic NMR Microscopy of Gas Phase

In a Poiseuille flow of a Newtonian liquid the coherent motion gives rise to the dominant effect, rendering contributions from the stochastic dispersion term 

A second imaging gradient (Gy) is added in order to obtain a spatial map of the displacements. A notable feature of the stimulated echo protocol is that during the flow encoding time, A, the magnetization is stored along the z axis and is subject to the longitudinal 

The complete expression for the effective diffusion, under laminar flow conditions, has been derived by Van den Broeck [24] for both short (t a2/ D) time scales 

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