Answer:
a) D = 4.88 * 10^(-14) m^2 / s
b) <em>t </em>= 1.1 hr
Solution:
a) Magnesium in Aluminum diffusion:
D = Do * exp(-Qd / RT)
= (1.2 * 10^(-4) m^2 / s) * exp ( - 130,000 / 8.31 * 723.15)
= 4.88 * 10^(-14) m^2 / s
D = 4.88 * 10^(-14) m^2 / s
b) The composition remains same at say the distance Xo:
(Cx - Co) / (Cs - Co) = Constant
Xo^2 / D_{550} * <em>t </em>= Xo^2 / D_{450} * 15
D_{550} * <em>t </em>= D_{450} * 15
(1.2 * 10^(-4) m^2 / s) * exp ( - 130,000 / 8.31 * 723.15) * <em>t</em>
(4.88 * 10^(-14) m^2 / s) * 15
by, solving for <em>t </em>we get:
<em>t </em>= 1.1 hr
So, the time required is 1.1 hr.
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Answer:
Deny
Explanation:
Under the New Technology System, the Deny permission is applied when the administrator wants to overrule the permission given to members of a group. The Allow and Deny options help in regulating access to the components of the system. Only authorized groups are granted access to the files.
Most times, the Deny permission is considered before the Allow permission. If the user is denied access to some files and granted access to some, the deny permission is most times considered first.
C. is the answer to that question
