Page 118 - Illustrated Pocket Dictionary of Chromatography

J

Johnson noise Generated in electrical circuitry because of the
presence of resistors and is proportional to the square root of the
resistance present: Noise (in V) µ÷R.

joule heating Conduction of electrical current through an elec-
trolytic solution generates heat due to the forced movement of ions
in opposing directions and results in Joule heating (also called Ohmic
heating). From a practical point of view this heating leads to alter-
ations in the solution viscosity and irreproducible profiles. In the
extreme, the solvent may actually boil, causing trapped air bubbles,
etc. Therefore, to avoid this the heat generated must be dissipated
from the system throughout the entire separation process.

Illustrated Pocket Dictionary of Chromatography, by Paul C. Sadek.
ISBN 0-471-20021-2 Copyright © 2004 John Wiley & Sons, Inc.
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