Diffusion convection concentration profile. The diffusion convection model concentration as a function of distance from the pyloric sphincter is shown at 20 (Figure 5
A), 100 (B) and 300 minutes (C) after administering the oral dose as a bolus to the stomach for an impermeable (P = 0) solute. The profile is shown for 4 different values of the dispersion time constant (TD): 2000 (red); 1000 (blue); 200 (green); and 20 minutes (black). For all profiles TF = 200 minutes; TG = 15 minutes; r = 1 cm; L = 600 cm and Dose = 1.