Page 318 - Electrical Engineering Dictionary

automatically reclaimed and reused. Rely- a consumable filler metal electrode and the
ing on garbage collection to manage mem- parts to be joined. The process is used with
ory simplifies the interfaces between pro- shielding gas and without the application of
gram components. Two main methods used pressure.
to implement garbage collection are refer-
ence counting and mark-and-sweep. gas substation an electric power substa-
tion in which the conductors are insulated
garbage collector a software run-time from each other and the ground by a high-
system component that periodically scans pressure gas, generally sulfur hexaflouride.
dynamically allocated storage and reclaims
allocated storage that is no longer in use gas tungsten arc welding (GTAW) a
(garbage). welding process that produces coalescence of
metals by heating them with an arc between
gas cable an electric power cable which a nonconsumable tungsten electrode and the
is pressurized with an insulating gas, typi- parts to be joined. The process is used with
cally sulfur hexaflouride, for its primary in- shielding gas and without the application of
sulation. pressure. Filler may or may not be used.

gas capacitor a capacitor whose dielec- gate (1) a logical or physical entity
tric is composed of a high-pressure gas, of- that performs one logical operation, such as
ten nitrogen or an electronegative gas such as AND, NOT, or OR.
sulfur hexaflouride. (2) the terminal of a FET to which controls
the flow of electrons from source to drain. It
gas circuit breaker a circuit breaker in is usually considered to be the metal contact
which the arc between the contacts is extin- at the surface of the die. The gate is usually
guished by immersion in or a blast of an elec- so thin and narrow that if any appreciable
tronegative gas. current is allowed to flow, it will rapidly heat
up and self-destruct due to I-R loss. This
gas discharge excitation electron impact same resistance is a continuing problem in
excitation or pumping of a laser medium oc- low noise devices, and has resulted in the cre-
curring as a result of collisions between the ation of numerous methods to alter the gate
lasing atoms or molecules and the discharge structure and reduce this effect.
electrons.
gate array a semicustom integrated cir-
gas dynamic excitation excitation or cuit (IC) consisting of a regular arrangement
pumping of a laser medium occurring as a re- of gates that are interconnected through one
sult of heating followed by rapid expansion or more layers of metal to provide custom
and cooling of a gaseous laser medium. functions. Generally, gate arrays are pre-
processed up to the first interconnect level
gas insulated switchgear circuit break- so they can be quickly processed with final
ers and switches whose primary insulation is metal to meet customer’s specified function.
compressed gas.
gate length the length in microns of that
gas laser laser in which the amplifying portion of the FET channel, as measured in
medium is a gas. the direction of channel current flow, that can
be pinched off by application of the proper
gas metal arc welding (GMAW) a weld- control bias. Gate lengths are usually on the
ingprocessthatproducescoalescenceofmet- order of 0.1 to 2 microns. The f max of a FET
als by heating them with an arc between is inversely proportional to the gate length.

c
2000 by CRC Press LLC