turned nuclide transport into mass balance in the intro.
contaminant containment in the component
reduced references to bcs and radionuclide transport in mass balance discussion.
Now emphasizing mass transfer and mass balance.
sifting and winnowing.
moving mass transfer to its own file
moved mass transfer out of lumped nuclide model
intro cleanup.
fixing intro
didn't need subsection heading
simplified deg_rate.
cleaned up mixed cell
added placeholder
brenner approximation.
moved number.
brackets
removed 1d bc ref
capital D
removed mass transfer from one dim ppm
moved implications for whatever modeling bit
fixed date.