With increasing of superficial gas velocities, the liquid flow regime was changed from homogeneous to transitional and radial gradient of axial liquid velocity was rather small.
Note that this is a radial gradient, whereas earlier you saw a linear gradient.
Controlling the source (s) of light in your designs (even if just with a linear or radial gradient) can help create atmosphere in your page designs.
One of my favorites is the good old gray to black (or darker gray) radial gradient.
