The difference is, they are exposed to a moving fluid for an extended period of time.
Chromatography, technique for separating the components, or solutes, of a mixture on the basis of the relative amounts of each solute distributed between a moving fluid stream, called the mobile phase, and a contiguous stationary phase.
If, for a particular solute, the distribution favours the moving fluid, the molecules will spend most of their time migrating with the stream and will be transported away from other species whose molecules are retained longer by the stationary phase.
The driving force for solute migration is the moving fluid, and the resistive force is the solute affinity for the stationary phase; the combination of these forces, as manipulated by the analyst, produces the separation.
Invented by Henri Pitot (1695 1771), it consists of a tube with a short, right-angled bend, which is placed vertically in a moving fluid with the mouth of the bent part directed upstream; the pressure, measured with an attached device, depends on the fluid flow and can be used to calculate the velocity.
Convection occurs when heat travels along with a moving fluid.
Moving fluid back and forth will greatly enhance mixing.
Increasing aiding buoyancy generates faster moving fluid flow as is evident in Figure 6(b).
The model problem is considered for a subsonic flow in a moving fluid.
