0 2 4 6 8 10 12 14 r/R$_{1}$ 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 k$_{c}$R$^{2}$$_{1}$/D$_{2}$=600 k$_{c}$R$^{2}$$_{1}$/D$_{2}$=480 k$_{c}$R$^{2}$$_{1}$/D$_{2}$=300 k$_{c}$R$^{2}$$_{1}$/D$_{2}$=180 k$_{c}$R$^{2}$$_{1}$/D$_{2}$=60 k$_{c}$R$^{2}$$_{1}$/D$_{2}$=6 k$_{c}$R$^{2}$$_{1}$/D$_{2}$=0.6 Figure 4: “Volume fraction” φ ≡ (4 / 3) πR 3 $_{2}$c (where c is concentration) of solute particles surrounding the chucker ( R$_{1}$/R$_{2}$ = 10 ) as a function of the distance from the centre of the chucker (expressed in units of R$_{1}$ ). The corresponding values of the dimensionless ratio k$_{c}$R 2 $_{1}$/D$_{2}$ are given in the legend (note that the solute particles can overlap). 24