Resistivity unit conversions
The Sack and Frole formula is for hydraulic resistivity, which is related to fluidics, not electrical resistivity. They're different things so you can't convert.

In basic SI units, electrical resistivity \$\rho\$ is in units of:

\$\text{kg}\cdot \text{m}^2\cdot A^{-2} \cdot s^{-2}\$
or in derived units \$\Omega\cdot \text{m}\$ or \$V\cdot A^{-1}\cdot \text{m}\$

The hydraulic resistivity is analogous in that the pressure (analogous to voltage) is in Pascals, the length in m and the flow rate (analogous to current flow in A = coulombs/s) in mmol/s but they are completely different physical things.