gc

gas chromatography (GC)

Type of chromatography with a gas mixture as the mobile phase. In a packed column, the packing or solid support (held in a tube) serves as the stationary phase (vapour-phase chromatography, or VPC) or is coated with a liquid stationary phase (gas-liquid chromatography, or GLC). In capillary columns, the stationary phase coats the walls of small-diameter tubes. The sample of gas or volatile liquid to be analyzed is injected into the inlet; its components move through with a carrier gas (usually hydrogen, helium, or argon) at rates influenced by their degree of interaction with the stationary phase. The temperature, nature of the stationary phase, and column length can be varied to improve separation. The gas stream issuing from the column's end may pass through a thermal conductivity detector or a flame ionization detector, where its properties are compared with those of known reference substances. GC is used to measure air pollutants, essential oils, gases or alcohol in blood, and composition of industrial process streams.

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gc

(communications)

gigahertz

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1.		GC - garbage collection.
2.		GC - A storage allocator with garbage collection by Hans-J. Boehm and Alan J. Demers. Gc is a plug-in replacement for C's malloc. Since the collector does not require pointers to be tagged, it does not attempt to ensure that all inaccessible storage is reclaimed. Version 3.4 has been ported to Sun-3, Sun-4, Vax/BSD, Ultrix, Intel 80386/Unix, SGI, Alpha/OSF/1, Sequent (single threaded), Encore (single threaded), RS/600, HP-UX, Sony News, A/UX, Amiga, NeXT. ftp://parcftp.xerox.com/pub/russell/gc3.4.tar.Z.