3.0 micron silica particles in 200 micron thickness cell, 2D
density is about 120%. (A): 3.0V, islands-labyrinth. At the
left-bottom corner, there is a 0.6mm diameter bubble. (B):
5.0V. (C): $7.0V$. (D): 9.0V, labyrinth. (E): 4.0V,
double-roll. (F): 6.0V, tornado. The fast movement of particles
blurred the image.
background: microscopic pattern (flower type): triangle convection cloud)