Simple example for photoreactions in viscous media

In Section 3.2 the relationship for the local rate of a simple photoreaction 

A combination of the last two equations allows the elimination of the exponential function 

An integration of this partial differential equation with respect to t yields 

The intention is to determine the functions G(z) and H t) in such a way that eq. (3.102) fulfils the boundary conditions, which are given by 

This means that the component A is homogeneously distributed within the cell at the beginning of the irradiation. On the other hand, at the limit z = 0 one finds using eq. (3.101) that 

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