Note that the product of the translational stream
variable (velocity, φ) and the flow
variable (current, Ṅ) is only conserved among species with the same specific mass.
This connector is not directly connected among different species. It is first converted to the
Reaction connector using the
ChemicalReaction adapter,
which reconciles the different specific masses.
For more information, please see the documentation of the Connectors package.