director of the Institute of Radium. He also continued
to oversee the construction of the 160-MeV synchrocy-
clotron at the new center for nuclear physics in Orsay,
a project she commenced before dying.
Jones reductor A column packed with amalgamated
zinc and used for prereduction of an analyte.
Josephson junction A type of electronic circuit
capable of switching at very high speeds when operated
at temperatures approaching absolute zero. Composed
of two superconductors that are separated by a thin
nonsuperconducting layer in which electrons can cross
through the insulating barrier, it was discovered by
Brian David Josephson, who won the Nobel Prize in
physics in 1973 with Leo Esaki and Ivar Giaever.joule The international unit of energy or work. The
amount of work done when a force of 1 Newton is
applied through a distance of 1 meter. One joule is 1
kg·m^2 /s^2 or 0.2390 calorie.Joule-Thompson effect The physical process in
which the temperature of a gas is changed by allowing
the gas to expand. Depending on the gas, the pressure,
and the temperature, the change can be positive or
negative.152 Jones reductor