Population genetics. Population genetics is a subfield of genetics that deals with genetic differences within and between populations, and is a part of evolutionary biology. Studies in this branch of biology examine such phenomena as adaptation, speciation, and population structure.
In the fluid-filled case, the wellbore is presumed to be full of either all liquid or gas which gets compressed as afterflow continues into the wellbore. The wellbore storage constant (C) is a function of the wellbore volume (Vw) and the wellbore fluid compressibility (cwb) as shown below: For a fluid-filled wellbore:
Quicksand and other non-Newtonian fluids share properties with both liquids and solids. Non-Newtonian fluids consist of tiny grains suspended in liquid, with the appearance of a solid or gel. Stand on quicksand and you will sink (though not as rapidly as movies and cartoons suggest). But strike it quickly and it will briefly harden.