Figure 2.

Spatio-temporal evolution of the overall probability density $p(z,\theta )=\varphi (z,\theta )$ for increasing dimensionless time instants—namely, $\theta =0,0.2,0.4\dots$ up to $\theta =2$ (blue curves) and $\theta =4,6,8\dots$ up to $\theta =40$ (red curves). (A) $De=1$; (B) $De=0.1$; (C) $De=0.01$.