A practical use of fast rotors can be found in centrifuging. Beams developed an "ultracentrifuge" which could develop forces equivalent to a billion times that of gravity. Centrifuges are useful in chemistry for separating solutions. Beams' new centrifuge found immediate use in medical research, and was instrumental in the isolation of the yellow fever virus. The ultracentrifuge can also be used to separate the isotopes of an element from each other. Beams was the first to use centrifugation to separate Uranium isotopes needed for nuclear power.