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Unformatted text preview: Name:_____________________________________________________ Section 2 Quiz 3 MTE 208 Fall 2008 20 Minutes This figure shows a portion of a concentration profile c(x) for a species A somewhere within the interior of a block of material B Use Ficks First and Second Laws of diffusion to answer the following questions. 1) What is the direction of the flux of A at point x 1 ? Place a check mark in the box that corresponds to the best answer. The flux of A at x 1 is to the right (increasing x) 2) What is the magnitude of the flux at point x 2 compared to the flux at point x 1 ? J 2 &lt; J 1 3) What is happening over time to the concentration of A at point x 2 ? The concentration of A is increasing 4) Write down the Arrhenius equation that shows how the diffusion coefficient (D) depends on temperature: &amp; - = kT E D D a o exp or &amp; - = RT E D D a o exp or &amp; - = kT Q D D o exp or &amp; - = RT Q D D o exp 5) Which generally has a larger activation energy for diffusion, interstitial impurity diffusion or...
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- Spring '08