| R | resistance | D | pore diameter |
| ρ | solution resistivity/conductivity | L | pore length |
| A(z) | cross sectional area perpendicular to z | z | length coordinate |
| R | resistance | D | pore diameter |
| ρ | solution resistivity/conductivity | L | pore length |
| A(z) | cross sectional area perpendicular to z | z | length coordinate |