Figure 6.

Simulation of effect of osmolality on diffusion curves

Because electrode spacing, transport number and clearance vary slightly between experiments, the original curves cannot be easily compared so values of λ and α were derived from eqns (12) and (13). These values were then inserted in eqn (1) to generate the curves shown in this figure. Equation (2) was used with a bias current of 20 nA to give the baseline for the first 10 s, then a main current of 100 nA was applied in the interval 10–60 s. A constant clearance of k’ = 0.02 s⁻¹ was used, the electrode spacing was 100 μm and the transport number was n_t = 0.3. The shape of the concentration surface changes dramatically as osmolality increases as seen when every fourth concentration curve is projected on the [TMA⁺]-Time plane (cf. Figs 2 and 3).