The infinite medium with a layer of uniform initial concentration

3 The infinite medium with a layer of uniform initial concentration 

With initial condition C=C0 for —X x +X and C=0 elsewhere, we can assume that the initial distribution is the sum of point sources uniformly distributed between —X and +X. Again, the amount of substance distributed per unit surface between x and x +dx is C0dx. Summing up the contribution of all the point sources such as — X x + 2f will give the concentration distribution 

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