Mean time of diffusion- and reaction-limited loading and unloading

Abstract Direct determination of mean diffusion times from the Laplace transform spatial average diffusing species for $$p=0$$ p = 0 offers advantage yielding closed-form expressions rather than sum-type ones obtained otherwise time-dependent solution. This is made use in present work to determine time diffusion- and reaction-limited loading unloading a into or out bodies different shape (plate, cylinder, sphere) important type boundary condition fixed concentration surrounding. approach particularly pays off more complex cases when calculation inverse becomes laborious. As an example such type, concomitant trapping untrapping within object during considered. The solutions are quantitatively discussed with examples literature. concept compared other constants, e.g., action lag.