,

,

,

where is time; , , , , and are parameters; and is a cubic equation with , . The solution to these equations allows both positive and negative values of the variables. A linear transformation of variables can convert this electrical system into a dynamically related chemical scheme that allows only positive state variables [2].

Thus with , , , the system becomes:

,

,

,

where , , represent concentrations of chemical species, with , . The chemical reaction scheme that leads to these equations is detailed in Table 1 of [2].