Figure 3.
Fourier transform methodology to obtain Dg(c0) from PER lipopolymer concentration profiles with corral length L = 250 µm and gradient diffusion coefficient Dg = 3(1 + 150c) µm2 s−1. (a) Concentration profiles from numerical solutions of the diffusion equation (A 1) with average mole fraction c0 = 0.03 and n = 1 (solid lines). Dashed lines are the first Fourier mode, whose exponentially decaying amplitude is plotted in panel (b) (circles) giving Dg ≈ 16.54 µm2 s−1. (c) Least-squares fitted values of Dg(c0) obtained from computations (to mimic experimental data) with various c0 and Dg = 3(1 + 150c) µm2 s−1 (circles). The solid line is a least-squares fit recovering Dg ≈ 3.01(1 + 149c) µm2 s−1.