text: :See entrainment for other types.
  In engineering, entrainment is the entrapment of one substance by another substance. For example:
  * The entrapment of liquid droplets or solid particulates in a flowing gas, as with smoke.
  * The entrapment of gas bubbles or solid particulates in a flowing liquid, as with aeration.
  * Given two mutually insoluble liquids, the emulsion of droplets of one liquid into the other liquid, as with margarine.
  * Given two gases, the entrapment of one gas into the other gas.
  * "Air entrainment" – The intentional entrapment of air bubbles into concrete.
  * Entrainment defect in metallurgy, as a result of folded pockets of oxide inside the melt.