Square patch of length and with somm

$=lmn$ thic.

density of medication $=A_1{P}_n,p_{-1}=100k{g}_{1}k{m}^3$

partion coefficint of $Q=0\mathrm{.}5$

interphase rondition $)=(0)=(0$

$D_{AP}=0\mathrm{.}1{10}^{-12}\frac{m^2}{s}$

$D_{As}={0\mathrm{.}2110}^{-12}\frac{m^2}{s}$

a$)$ differential form of thomass tronsfor equatim at st$.$j$1$ for patch and skin side

b$)$ Fick's low and simplify.

C$)$ mass flux $n_{AP}$ it $)=(0$

d$)$ mass concontration $P_{A,S},lx=0l$

e$)$ total mass conc difference between the patch and the skin. $Q_{Ase}{P}_{A_1{P}_{1}i}-P_{\text{A}\text{i}\text{s}\text{i}}$ coefficient $D_{AP},D_{AS}$ ilP, LS if PAIsi is the uniform mass cenc. Of $A$ in the skin

F$)$ thickness of the skin that all the diug is consimed.