Diffusion equation: time for an element to diffuse at set distance

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To calculate the time for an element to diffuse a set distance in microns, the appropriate equation depends on the context of the diffusion process. The equations X = sqrt(DT) and X = sqrt(2DT) are used in different scenarios; the latter is typically applied for one-dimensional diffusion in a medium. Clarification on the specific situation or conditions of the diffusion is necessary to determine which equation is suitable. Understanding the parameters involved, such as boundary conditions and the nature of the diffusion, is crucial for accurate calculations. Proper application of these equations will yield the time required for diffusion over the specified distance.
jblakes
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Good morning,

I'm trying to workout the time for an element to diffuse at set distance in microns.

I have the distance, the diffusion coefficient, just unsure which equation I actually use.

X= sqrt DT or the other one x= sqrt 2DT.

I can't seem to figure out when you use one and not the other.

Thanks in advance
James
 
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jblakes said:
Good morning,

I'm trying to workout the time for an element to diffuse at set distance in microns.

I have the distance, the diffusion coefficient, just unsure which equation I actually use.

X= sqrt DT or the other one x= sqrt 2DT.

I can't seem to figure out when you use one and not the other.

Thanks in advance
James
What is the exact situation you are looking at?
 

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