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Unformatted text preview: does / does not) change with time. Ficks 2 nd Law is ( steady / nonsteady) state diffusion. Concentration ( does / does not) change with time. 3. (8 pts) Ficks first law tells that Diffusion flux dx dC D J = . And the diffusion coefficient ) exp( RT d Q D D = , where Qd is the activation energy. As shown in the following graph, we plot the natural logarithm of D versus the reciprocal of temperature for two materials A and B. From the following graph, which line shows: a. Higher diffusion flux (at the same dC/dx ) (A / B) b. Higher activation energy (at the same temperature) (A / B) c. V a c a n c y d i f f u s i o n (A / B) d. Interstitial diffusion (A / B) A 1/T ln D B...
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 Spring '08
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