| NPP | Nernst-Planck and Poisson |
| SCB | Space charge breakdown |
| QEL | Quasi-equilibrium layer |
| CEM | Cation-exchange membrane |
| AEM | Anion exchange membrane |
| REN | Region of electrical neutrality |
| SCR | Space charge region |
| wQEL | Without Quasi-equilibrium boundary layer |
| QCD | Quasi-uniform charge distribution |