diffusion gradient

diffusion gradient

[də′fyü·zhən ‚grād·ē·ənt]
(physics)
The graphed distance of penetration (diffusion) versus concentration of the material (or effect) diffusing through a second material; applies to heat, liquids, solids, or gases.
References in periodicals archive ?
In this system the calcium and phosphate concentrations decrease along a diffusion gradient between the reservoir and the precipitation band forms near the center of the gel.
we aimed to test whether the geographic diffusion gradient evident for prazosin prescribing reflected regional variations in the delivery of other PTSD pharmacotherapy care as measured by three quality prescribing indicators: (1) SSRI/SNRI use, (2) benzodiazepine use, or (3) minimal threshold prazosin daily dosing.
Contract notice: Delivery: 1 piece petrofizycznego mri scanner; diffusion gradient system; set to simulate the conditions of deposit; system and the mri scanner; imaging gradient system; imaging software for 1d, 2d and 3d, and to analyze the petrophysical parameters.
The b-value used in DTI experiments is determined by the square of the diffusion gradient strength and the diffusion time.
3) Essentially, DWI uses the application of a diffusion gradient to make the MRI signal sensitive to the amount of diffusion that occurs parallel to the direction of the diffusion gradient.
A cross flow/secondary force is applied to the channel that creates a diffusion gradient, which moves larger particles toward the wall.
Plasma imbibition is the passive exchange of nutrients across a diffusion gradient.
The following 13 diffusion gradient b values were used: 0, 20, 40, 60, 80, 100, 140, 180, 240, 300, 500, 1000 and 1500 s/mm [sup]2 , the gradients were applied in three orthogonal directions and subsequently averaged to minimize the effects of diffusion anisotropy.
First, the influence of molecular diffusion gradients on stem cell signaling pathways is described in detail, including a summary of recent discoveries in how gas and nutrient concentrations can influence stem cell potency, differentiation, and metabolism.
Restricted diffusion appears as an area of increased signal on DWI and reduced signal on ADC maps which are calculated from a matrix of tensor vectors obtained in three planes without and with application of diffusion gradients.
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