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fuzzy system fused-junction transistor See alloy-junction tran- fusion piercing [ ENG ] A method of producing vertical blastholes by virtually burning holes insistor. { ¦fyu ¨ zd ¦jəŋkиshən tranzisиtər} fused semiconductor [ ELECTR ] Junction rock. Also known as piercing. { fyu ¨ иzhən pirиsiŋ }formed by recrystallization on a base crystal from a liquid phase of one or more components and fusion-piercing drill [ ENG ] A machine designed to use the fusion-piercing mode of producingthe semiconductor. { ¦fyu ¨ zd semиiиkən dəkи tər } holes in rock. Also known as det drill; jet-pierc- ing drill; Linde drill. { fyu ¨ иzhən pirsиiŋdril } fuse gage [ ENG ] An instrument for slicing time fuses to length. { fyu ¨ z ga ¯ j} fuzzy controller [ CONT SYS ] An automatic con- troller in which the relation between the state fusehead [ ENG ] That part of an electric detona- tor consisting of twin metal conductors, bridged variables of the process under control and the action variables, whose values are computedby fine resistance wire, andsurrounded by a bead of igniting compound which burns when the fir- from observations of the state variables, is given as a set of fuzzy implications or as a fuzzy rela-ing current is passed through the bridge wire. { fyu ¨ zhed } tion. { ¦fəzиe ¯ kəntro ¯ lиər} fuzzy system [ SYS ENG ] A process that is too fuse lighter [ ENG ] A device for facilitating the ignition of the powder core of a fuse. { fyu ¨ z complex to be modeled by using conventional mathematical methods, and that gives rise tolı ¯ dиər} fusibility [ THERMO ] The quality or degree of be- data that are, in general, soft, with no precise boundaries; examples are large-scale engi-ing capable of being liquefied by heat. { fyu ¨ и zəbilиədиe ¯ } neering complex systems, social systems, eco- nomic systems, management systems, medical fusible plug See safety plug. { ¦fyu ¨ иzəиbəl pləg} fusing disk [ MECH ENG ] A rapidly spinning disk diagnostic processes, and human perception. { ¦fəzиe ¯ sisиtəm}that cuts metal by melting it. { fyu ¨ zиiŋdisk } 239 This page intentionally left blank. G a part in a jig, fixture, or qualifying gage. g See gram. { ga ¯ j po ˙ int } G [ ELEC ] See conductance. [ MECH ] A unit of gage pressure [ MECH ENG ] The amount by acceleration equal to the standard acceleration which the total absolute pressure exceeds the of gravity, 9.80665 meters per second per second, ambient atmospheric pressure. { ga ¯ j preshи or approximately 32.1740 feet per second per ər} second. Also known as fors; grav. gaging hatch [ ENG ] An opening in a tank or GaAs FET See gallium arsenide field-effect transis- other vessel through which measuring and sam- tor. { gasfet } pling can be performed. { ga ¯ jиiŋhach } gabion [ ENG ] A bottomless basket of wicker- gaging tape [ ENG ] A metal measuring tape work or metal iron filled with earth or stones; used to determine the depth of liquid in a tank. used in building fieldworks or as revetments in { ga ¯ jиiŋta ¯ p} mining. Also known as pannier. { ga ¯ иbe ¯ иən} gain [ ELECTR ] The increase in signal power that gableboard See vergeboard. { ga ¯ иbəlbo ˙ rd } is produced by an amplifier; usually given as Gabor trolley [ ENG ] A small three-wheel trolley the ratio of output to input voltage, current, or with knife-edge wheels, used in constructing tra- power, expressed in decibels. Also known as jectories of charged particles in an electric field. transmission gain. [ ENG ] A cavity in a piece { ga ¨ bo ˙ r tra ¨ иle ¯ } of wood prepared by notching or mortising so gage Also spelled gauge. [ CIV ENG ] The dis- that a hinge or other hardware or another piece tance between the inner faces of the rails of of wood can be placed on the cavity. { ga ¯ n} railway track; standard gage in the United States gain asymptotes [ CONT SYS ] Asymptotes to a is 4 feet 8 1 / 2 inches (1.44 meters). [ DES logarithmic graph of gain as a function of fre- ENG ] 1. A device for determining the relative quency. { ga ¯ n asиəmto ¯ ts } shape or size of an object. 2. The thickness gain-crossover frequency [ CONT SYS ] The fre- of a metal sheet, a rod, or a wire. [ ENG ] The quency at which the magnitude of the loop ratio minimum sieve size through which most (95% is unity. { ¦ga ¯ n ¦kro ˙ so ¯ иvər fre ¯ иkwənиse ¯ } or more) of an aggregate will pass. { ga ¯ j} gain margin [ CONT SYS ] The reciprocal of the gage block [ DES ENG ] A chrome steel block magnitude of the loop ratio at the phase cross- having two flat, parallel surfaces with the parallel over frequency, frequently expressed in decibels. distance between them being the size marked { ga ¯ n ma ¨ rиjən} on the block to a guaranteed accuracy of a few gain scheduling [ CONT SYS ] A method of elimi- millionths of an inch; used as the standard of nating influences of variations in the process precise lineal measurement for most manufac- dynamics of a control system by changing the turing processes. Also known as precision parameters of the regulator as functions of auxil- block; size block. { ga ¯ j bla ¨ k} iary variables which correlate well with those gage cock [ ENG ] A valve located on a water dynamics. { ga ¯ n skejиəиliŋ } column of a boiler drum. { ga ¯ j ka ¨ k} gal [ MECH ] 1. The unit of acceleration in the gage glass [ ENG ] A glass, plastic, or metal centimeter-gram-second system, equal to 1 cen- tube, usually equipped with shutoff valves, that timeter per second squared; commonly used in is connected by a suitable fitting to a tank or geodetic measurement. Formerly known as gali- vessel, for the measurement of liquid level. leo. Symbolized Gal. 2. See gallon. { gal } { ga ¯ j glas } Gal See gal. { gal } gage length [ ENG ] Original length of the por- Galilean transformation [ MECH ] A mathemati- tion of a specimen measured for strain, length cal transformation used to relate the space and changes, and other characteristics. { ga ¯ j time variables of two uniformly moving (inertial) leŋkth } reference systems in nonrelativistic kinematics. gage plate [ CIV ENG ] A plate inserted between { galиə¦le ¯ иən tranzиfərma ¯ иshən} the parallel rails of a railroad track to maintain galileo See gal. { galиəle ¯ иo ¯ } the gage. { ga ¯ j pla ¯ t} Galileo’s law of inertia See Newton’s first law. { galиəle ¯ иo ¯ z ¦lo ˙ əvinərиshə } gage point [ DES ENG ] A point used to position Copyright 2003 by The McGraw-Hill Companies, Inc. Click Here for Terms of Use. Galitzin pendulum Galitzin pendulum [ MECH ] A massive horizon- gamma camera [ ENG ] An instrument con- sisting of a large, thin scintillation crystal or arraytal pendulum that is used to measure variations in the direction of the force of gravity with time, of photomultiplier tubes, a multichannel colli- mator, and circuitry to analyze the pulses pro-and thus serves as the basis of a seismograph. {ga ¨ ¦litиsən penиjəиləm } duced by the photomultipliers; used to visualize the distribution of radioactive compounds in the galley [ ENG ] The kitchen of a ship, airplane, or trailer. { galиe ¯ } human body. { gamиəkamиrə } gamma counter [ ENG ] A device for detecting gallium arsenide field-effect transistor [ ELECTR ] A field-effect transistor in which current between gamma radiation, primarily through the detec- tion of fast electrons produced by the gammathe ohmic source and drain contacts is carried by free electrons in a channel consisting of n- rays; it either yields information about integrated intensity within a time interval or detects eachtype gallium arsenide, and this current is modu- lated by a Schottky-barrier rectifying contact photon separately. { gamиəkau ˙ ntиər} gamma logging [ ENG ] Obtaining, by means ofcalled the gate that varies the cross-sectional area of the channel. Abbreviated GaAs FET. a gamma-ray probe, a record of the intensities of gamma rays emitted by the rock strata pene-{ galиe ¯ иəm a ¨ rsиənı ¯ d fe ¯ ld i¦fekt tranzisиtər} gallon [ MECH ] Abbreviated gal. 1. A unit of trated by a borehole. { gamиəla ¨ gиiŋ } gamma-ray altimeter [ ENG ] An altimeter, usedvolume used in the United States for measure- ment of liquid substances, equal to 231 cubic at altitudes under several hundred feet, that measures the photon backscatter from the earthinches, or to 3.785 411 784 ϫ 10 Ϫ3 cubic meter, or to 3.785 411 784 liters; equal to 128 fluid resulting from the transmission of photons to earth from a cobalt-60 gamma source in theounces. 2. A unit of volume used in the United Kingdom for measurement of liquid and solid plane. { gamиəra ¯ altimиədиər} gamma-ray detector [ ENG ] An instrument thatsubstances, usually the former; equal to 4.54609 ϫ 10 Ϫ3 cubic meter, or to 4.54609 liters; equal registers the presence of gamma rays. { gamи əra ¯ ditekиtər}to 160 fluid ounces. Also known as imperial gallon. { galиən} gamma-ray level indicator [ ENG ] A level indica- tor in which the rising level of the liquid or other Galton whistle [ ENG ACOUS ] A short cylindrical pipe with an annular nozzle, which is set into material reduces the amount of radiation pass- ing from a gamma-ray source through the con-resonant vibration in order to generate ultra- sonic sound waves. { go ˙ lиtən wisиəl } tainer to a Geiger counter or other radiation de- tector. { gamиəra ¯ ¦levиəl inиdəka ¯ dиər} galvanic [ ELEC ] Pertaining to electricity flowing as a result of chemical action. { galvanиik } gamma-ray probe [ ENG ] A gamma-ray counter built into a watertight case small enough to be galvanic battery [ ELEC ] A galvanic cell, or two or more such cells electrically connected to pro- lowered into a borehole. { gamиəra ¯ pro ¯ b} gamma-ray tracking [ ENG ] Use of threeduce energy. { galvanиik badиəиre ¯ } galvanic cell [ ELEC ] An electrolytic cell that is tracking stations, located at the three corners of a triangle centered on a missile about to becapable of producing electric energy by electro- chemical action. { galvanиik sel } launched, to obtain accurate azimuthal tracking of a cobalt-60 gamma source in the tail. galvanic couple [ ELEC ] A pair of unlike sub- stances, such as metals, which generate a volt- { gramиəra ¯ trakиiŋ } gamma-ray well logging [ ENG ] Measurementage when brought in contact with an electrolyte. { galvanиik kəpиəl } of gamma-ray intensity versus depth down the wellbore; used to identify rock strata, their posi- galvanic current [ ELEC ] A steady direct current. { galvanиik kəиrənt } tion, and their thicknesses. { gamиəra ¯ wel la ¨ gиiŋ } galvanometer [ ENG ] An instrument for indicat- ing or measuring a small electric current by gammeter [ ENG ] A template fashioned of trans- parent material and marked with a calibratedmeans of a mechanical motion derived from electromagnetic or electrodynamic forces pro- scale; when positioned on a sensitometric curve it is used to determine the slope of the straight-duced by the current. { galиvəna ¨ mиədиər} galvanometer recorder [ ENG ACOUS ] A sound line portion. { game ¯ dиər} gang [ ELEC ] A mechanical connection of two orrecorder in which the audio signal voltage is applied to a coil suspended in a magnetic field; more circuit devices so that they can be varied at the same time. { gaŋ }the resulting movements of the coil cause a tiny attached mirror to move a reflected light beam gang chart [ IND ENG ] A multiple-activity proc- ess chart used for groups of men on materials-back and forth across a slit in front of a moving photographic film. { galиvəna ¨ mиədиərriko ˙ rdи handling operations. { gaŋcha ¨ rt } gang drill [ MECH ENG ] A set of drills operatedər} gambrel roof [ BUILD ] A roof with two sloping together in the same machine; used in rock dril- ling. { gaŋdril }sides stepped at different angles on each side of the center ridge; the lower slope is steeper gang milling [ ENG ] Rolling of material by means of a composite machine with numerousthan the upper slope. { gamиbrəl ru ¨ f} gamma [ MECH ] A unit of mass equal to 10 Ϫ6 cutting blades. { gaŋmilиiŋ } gang saw [ MECH ENG ] A steel frame in whichgram or 10 Ϫ9 kilogram. { gamиə } 242 GasFET thin, parallel saws are arranged to operate simul- material and designed for insertion into a pipe- line followed by inflation to halt the flow of gas. taneously in cutting logs. { gaŋso ˙ } { gas bag } gantlet [ CIV ENG ] A stretch of overlapping rail- gas bearing [ MECH ENG ] A journal or thrust road track, with one rail of one track being be- bearing lubricated with gas. Also known as gas- tween the two rails of another track; used over lubricated bearing. { gas berиiŋ } narrow bridges and passes. { go ˙ ntиlət} gas burner [ ENG ] A hole or a group of holes gantry [ ENG ] A frame erected on side supports through which a combustible gas or gas-air mix- so as to span an area and support and hoist ture flows and burns. { gas bərиnər} machinery and heavy materials. { ganиtre ¯ } gas cleaning [ ENG ] Removing ingredients, pol- gantry crane [ MECH ENG ] A bridgelike hoisting lutants, or contaminants from domestic and in- machine having fixed supports or arranged for dustrial gases. { gas kle ¯ nиiŋ } running along tracks on ground level. { ganи gas-compression cycle [ MECH ENG ] A refriger- tre ¯ kra ¯ n} ation cycle in which hot, compressed gas is gantry-type robot [ CONT SYS ] A continuous- cooled in a heat exchanger, then passes into a path, Cartesian-coordinate robot constructed in gas expander which provides an exhaust stream a bridge shape that uses rails to move along of cold gas to another heat exchanger that han- a single horizontal axis or along either of two dles the sensible-heat refrigeration effect and perpendicular horizontal axes. { ganиtre ¯ ¦tı ¯ p exhausts the gas to the compressor. { ¦gas ro ¯ ba ¨ t} kəm¦preshиən sı ¯ иkəl} Gantt chart [ IND ENG ] In production planning gas compressor [ MECH ENG ] A machine that and control, a type of bar chart depicting the increases the pressure of a gas or vapor by in- work planned and done in relation to time; each creasing the gas density and delivering the fluid division of space represents both a time interval against the connected system resistance. { gas and the amount of work to be done during that kəmpresиər} interval. { gant cha ¨ rt } gas constant [ THERMO ] The constant of pro- Gantt task and bonus plan [ IND ENG ] A wage portionality appearing in the equation of state incentive plan in which high task efficiency is of an ideal gas, equal to the pressure of the gas maintained by providing a percentage bonus as times its molar volume divided by its tempera- a reward for production in excess of standard. ture. Also known as gas-law constant; universal gas constant. { gas ka ¨ nиstənt } { gant ¦task ən bo ¯ иnəs plan } gas cycle [ THERMO ] A sequence in which a gas- gap [ ELEC ] The spacing between two electric eous fluid undergoes a series of thermodynamic contacts. { gap } phases, ultimately returning to its original state. gap-filler radar [ ENG ] Radar used to fill gaps in { gas sı ¯ иkəl} radar coverage of other radar. { gap filиər gas cylinder [ MECH ENG ] The chamber in which ra ¯ da ¨ r} a piston moves in a positive displacement en- gap-framepress [ MECH ENG ] A punch press gine or compressor. { gas silиənиdər} whose frame is open at bed level so that wide gas dehydrator [ CHEM ENG ] A device or system work or strip work can be inserted. { ¦ga ¯ p to remove moisture vapor from a gas stream, fra ¯ mpres } usually incorporates desiccant-type packed gap lathe [ MECH ENG ] An engine lathe with a towers. { gas de ¯ hı ¯ dra ¯ dиər} sliding bed providing enough space for turning gas-deviation factor See compressibility factor. large-diameter work. { gap la ¯ th } { ¦gas de ¯ иve ¯ a ¯ иshən fakиtər} gap scanning [ ENG ] In ultrasonic testing, a gas engine [ MECH ENG ] An internal combus- coupling technique in which a sound beam is tion engine that uses gaseous fuel. { gas projected through a short fluid column that flows enиjən} through a nozzle on an ultrasonic search unit. gaseous conduction analyzer [ ENG ] A device { gap skanиiŋ } to detect organic vapors in air by measuring the garnet hinge [ DES ENG ] A hinge with a vertical change in current that flows between a heated bar and horizontal strap. { ga ¨ rиnət hinj } platinum anode and a concentric platinum cath- garret [ BUILD ] The part of a house just under ode. { ¦gashиəskən¦dəkиshən anиəlı ¯ zиər} the roof. { garиət} gaseous diffusion [ CHEM ENG ] 1. Pressure-in- garter spring [ DES ENG ] A closed ring formed duced free-molecular transfer of gas through mi- of helically wound wire. { ga ¨ rdиər spriŋ } croporous barriers as in the process of making gas absorption operation [ CHEM ENG ] The re- fissionable fuel. 2. Selective solubility diffu- covery of solute gases present in gaseous mix- sion of gas through nonporous polymers by ab- tures of noncondensables; this recovery is gener- sorption and solution of the gas in the polymer ally achieved by contacting the gas stream with matrix. { ¦gashиəsdifyu ¨ иzhən} a liquid that offers specific or selective solubility gas etching [ ENG ] The removal of material from for the solute gas to be recovered, or with an a semiconductor circuit by reaction with a gas adsorbent (for example, synthetic or natural zeo- that forms a volatile compound. { gas echиiŋ } lite) that accepts only specific molecule sizes or GasFET [ ENG ] A gas sensor based on changes, shapes. { gas əbso ˙ rpиshən a ¨ pиəra ¯ иshən} upon exposure to hydrogen, in the surface part of the work function of a palladium component gas bag [ ENG ] A bag made of gas-impermeable 243 gas-filled thermometer that serves as the gate contact of a metal oxide a filter and a bed of adsorbent material. { gas mask } semiconductor field-effect transistor (MOS- gas meter [ ENG ] An instrument for measuring FET). { gasfet } and recording the amount of gas flow through a gas-filled thermometer [ ENG ] A thermometer pipe. { gas me ¯ dиər} which uses a gas (usually nitrogen or hydrogen), gasoline engine [ MECH ENG ] An internal com- that approximately follows the ideal gas law. bustion engine that uses a mixture of air and { gas fild thərma ¨ mиədиər} gasoline vapor as a fuel. { gasиəle ¯ n enиjən} gas filter [ CHEM ENG ] A device used to remove gasoline pump [ MECH ENG ] A device that liquid or solid particles from a flowing gas pumps and measures the gasoline supplied to stream. { gas filиtər} a motor vehicle, as at a filling station. { gasи gas furnace [ ENG ] An enclosure in which a gas- əle ¯ n pəmp } eous fuel is burned. { gas fərиnəs} gasometer [ ENG ] A piece of equipment that gas generator [ CHEM ENG ] A chemical plant for holds and measures gas; may be used in analyti- producing gas from coal, for example, water cal chemistry to measure the quantity of gas gas. [ MECH ENG ] An apparatus that supplies evolved in a reaction. { gasa ¨ mиədиər} a high-pressure gas flow to drive compressors, gas packing [ IND ENG ] Packing a material such airscrews, and other machines. { gas jenиə as food in an atmosphere consisting of an oxy- ra ¯ dиər} gen-free gas. { gas pakиiŋ } gas heater [ MECH ENG ] A unit heater designed gas pliers [ DES ENG ] Pliers for gripping round to supply heat by forced convection, using gas objects such as pipes, tubes, and circular rods. as a heat source. { gas he ¯ dиər} { gas plı ¯ иərz } gas holder [ ENG ] Gas storage container with gas producer [ CHEM ENG ] A device for com- vertically free top section that moves up or down plete gasification of coal by utilizing simultane- to adjust to the volume of gas held. { gas ously the air and water-gas reactions. { gas ho ¯ lиdər} prədu ¨ sиər} gas hole [ ENG ] A cavity formed in a casting as gas reversion [ CHEM ENG ] A process which a result of cavitation. { gas ho ¯ l} combines thermal cracking or reforming of naph- gasification [ CHEM ENG ] Any chemical or heat tha with thermal polymerization or alkylation of process used to convert a substance to a gas; hydrocarbon gases carried out in the same reac- coal is converted by the Hygas process to a gas- tion zone. { gas rivərиzhən} eous fuel. { gasиəиfəka ¯ иshən} gas scrubbing [ CHEM ENG ] Removal of gas- gasifier [ CHEM ENG ] A unit for producing gas, eous or liquid impurities from a gas by the action particularly synthesis gas from coal. { gasи of a liquid; the gas is contacted with the liquid əfı ¯ иər} which removes the impurities by dissolving or gas injection [ MECH ENG ] Injection of gaseous by chemical combination. { gas skrəbиiŋ } fuel into the cylinder of an internal combustion gas seal [ ENG ] A seal which prevents gas from engine at the appropriate part of the cycle. leaking to or from a machine along a shaft. { gas injekиshən} { gas se ¯ l} gasket [ ENG ] A packing made of deformable gassing [ ELEC ] The evolution of gas in the form material, usually in the form of a sheet or ring, of small bubbles in a storage battery when charg- used to make a pressure-tight joint between sta- ing continues after the battery has been com- tionary parts. Also known as static seal. pletely charged. [ ENG ] 1. Absorption of gas { gasиgit } by a material. 2. Formation of gas pockets in gas law [ THERMO ] Any law relating the pres- a material. 3. Evolution of gas from a material sure, volume, and temperature of a gas. during a process or procedure. { gasиiŋ } { gas lo ˙ } gas tank [ ENG ] A tank for storing gas or gaso- gas-law constant See gas constant. { gas lo ˙ line. { gas taŋk} ka ¨ nиstənt } gas thermometer [ ENG ] A device to measure gas lift [ CHEM ENG ] Solids movement opera- temperature by measuring the pressure exerted tion in which an upward-flowing gas stream in by a definite amount of gas enclosed in a con- a closed conduit or vessel is used to lift and stant volume; the gas (preferably hydrogen or move powdered or granular solid material. helium) is enclosed in a glass or fused-quartz { gas lift } bulb connected to a mercury manometer. Also gas making [ CHEM ENG ] Making water gas or known as constant-volume gas thermometer. air gas by the action of steam and air upon hot { ¦gas thərma ¨ mиədиər} coke. { gas ma ¯ kиiŋ } gas thermometry [ ENG ] Measurement of tem- gas manometer [ ENG ] A gage for determining peratures with a gas thermometer; used with the difference in pressure of two gases, usually helium down to about 1 K. { ¦gas thərma ¨ mи by measuring the difference in height of liquid əиtre ¯ } columns in the two sides of a U-tube. { ¦gas gas trap [ CIV ENG ] A bend or chamber in a drain məna ¨ mиədиər} or sewer pipe that prevents sewer gas from es- gas mask [ ENG ] A device to protect the eyes caping. { gas trap } and respiratory tract from noxious gases, vapors, gas-treating system [ CHEM ENG ] A process system to remove nonhydrocarbon impuritiesand aerosols, by removing contamination with 244 gear drive (such as water vapor, hydrogen sulfide, or carbon high-quality glass to be taken from the center. { gathиəиriŋriŋ } dioxide) from wellhead gas. { gas tre ¯ dиiŋ gating [ ELECTR ] The process of selecting those sisиtəm} portions of a wave that exist during one or more gas-tube boiler See waste-heat boiler. { gas selected time intervals or that have magnitudes tu ¨ b bo ˙ ilər} between selected limits. [ ENG ] A network of gas turbine [ MECH ENG ] A heat engine that connecting channels, including sprues, runners, converts the energy of fuel into work by using gates, and cavities, which conduct molten metal compressed, hot gas as the working medium and to the mold. { ga ¯ dиiŋ } that usually delivers its mechanical output gating waveform See gate. { ¦ga ¯ dиiŋwa ¯ vfo ˙ rm } power either as torque through a rotating shaft Gaussian weighing method [ ENG ] A method (industrial gas turbines) or as jet power in the used to determine the accuracy of equal-arm form of velocity through an exhaust nozzle (air- balances and to test standard weights in which craft jet engines). Also known as combustion the sample is placed on one pan and the compar- turbine. { gas tərиbən} ative weights on the other, and then the weights gas-turbine nozzle [ MECH ENG ] The compo- are interchanged in a second weighing. { gau ˙ sи nent of a gas turbine in which the hot, high- e ¯ иən wa ¯ иiŋmethиəd} pressure gas expands and accelerates to high gaussmeter [ ENG ] A magnetometer whose velocity. { gas tərиbən na ¨ zиəl} scale is graduated in gauss or kilogauss, and gas valve [ ENG ] An exhaust valve, held shut by usually measures only the intensity, and not the rubber springs, used to discharge gas from the direction, of the magnetic field. { gau ˙ sme ¯ dи extreme top of a balloon. { gas valv } ər} gas vent [ ENG ] A pipe or hole that allows gas Gauss method of weighing See double weighing. to pass off. { gas vent } { ¦gau ˙ s ¦methиəd əv wa ¯ иiŋ } gate [ CIV ENG ] A movable barrier across an Gauss’ principle of least constraint [ MECH ] opening in a large barrier, a fence, or a wall. The principle that the motion of a system of [ ELECTR ] 1. A circuit having an output and a interconnected material points subjected to any multiplicity of inputs and so designed that the influence is such as to minimize the constraint output is energized only when a certain combina- on the system; here the constraint, during an tion of pulses is present at the inputs. 2. A infinitesimal period of time, is the sum over the circuit in which one signal, generally a square points of the product of the mass of the point wave, serves to switch another signal on and times the square of its deviation from the posi- off. 3. One of the electrodes in a field-effect tion it would have occupied at the end of the transistor. 4. An output element of a cryotron. time period if it had not been connected to other 5. To control the passage of a pulse or signal. points. { gau ˙ s prinиsəиpəl əv ¦le ¯ st kənstra ¯ nt } 6. In radar, an electric waveform which is applied Gay-Lussac’s second law [ THERMO ] The law to the control point of a circuit to alter the mode that the internal energy of an ideal gas is inde- of operation of the circuit at the time when the pendent of its volume. { ga ¯ иlu ˙ sa ¨ ks sekиənd waveform is applied. Also known as gating lo ˙ } waveform. [ ENG ] 1. A device, such as a valve Gay-Lussac tower [ CHEM ENG ] A component or door, for controlling the passage of materials part in the chamber process for sulfuric acid pro- through a pipe, channel, or other passageway. duction that absorbs nitrogen oxides to form 2. A device for positioning the film in a camera, nitrous vitriol. { gaиlu ˙ sa ¨ k tau ˙ иər} printer, or projector. { ga ¯ t} g-cal See calorie. { je ¯ kal } gate-array device [ ELECTR ] An integrated logic g-cm See gram-centimeter. circuit that is manufactured by first fabricating gear [ DES ENG ] A toothed machine element a two-dimensional array of logic cells, each of used to transmit motion between rotating shafts which is equivalent to one or a few logic gates, when the center distance of the shafts is not too and then adding final layers of metallization that large. [ MECH ENG ] 1. A mechanism per- determine the exact function of each cell and forming a specific function in a machine. 2. An interconnect the cells to form a specific network adjustment device of the transmission in a motor when the customer orders the device. { ga ¯ t vehicle which determines mechanical advantage, əra ¯ divı ¯ s} relative speed, and direction of travel. { gir } Gates crusher [ MECH ENG ] A gyratory crusher gear case [ MECH ENG ] An enclosure, usually which has a cone or mantle that is moved eccen- filled with lubricating fluid, in which gears oper- trically by the lower bearing sleeve. { ga ¯ ts ate. { gir ka ¯ s} krəshиər} gear cutter [ MECH ENG ] A machine or tool for gate valve [ MECH ENG ] A valve with a disk- cutting teeth in a gear. { gir kədиər} shaped closing element that fits tightly over an gear cutting [ MECH ENG ] The cutting or form- opening through which water passes. { ga ¯ t ing of a uniform series of toothlike projections valv } on the surface of a workpiece. { gir kədиiŋ } gathering iron [ ENG ] A rod used to collect mol- gear down [ MECH ENG ] To arrange gears so the ten glass for glassblowing. { gathиəиriŋı ¯ иərn } driven part rotates at a slower speed than the gathering ring [ ENG ] A clay ring placed on mol- driving part. { ¦gir dau ˙ n} gear drive [ MECH ENG ] Transmission of motionten glass to collect impurities and thus permit 245 geared turbine or torque from one shaft to another by means complementary projections on another wheel to transmit force and motion. { gir te ¯ th } of direct contact between toothed wheels. gear train [ MECH ENG ] A combination of two or { gir drı ¯ v} more gears used to transmit motion between geared turbine [ MECH ENG ] A turbine con- two rotating shafts or between a shaft and a nected to a set of reduction gears. { ¦gird slide. { gir tra ¯ n} tərиbən} gear up [ MECH ENG ] To arrange gears so that gear forming [ MECH ENG ] A method of gear the driven part rotates faster than the driving cutting in which the desired tooth shape is pro- part. { ¦gir əp} duced by a tool whose cutting profile matches gear wheel [ MECH ENG ] A wheel that meshes the tooth form. { gir fo ˙ rиmiŋ } gear teeth with another part. { gir we ¯ l} gear generating [ MECH ENG ] A method of gear geepound See slug. { je ¯ pau ¨ nd } cutting in which the tooth is produced by the Geiger-Mu ¨ ller probe [ ENG ] A Geiger-Mu ¨ ller conjugate or total cutting action of the tool plus counter in a watertight container, lowered into the rotation of the workpiece. { gir jenиə a borehole to log the intensity of the gamma rays ra ¯ dиiŋ } emitted by radioactive substances in traversed gear grinding [ MECH ENG ] A gear-cutting rock. Also known as electronic logger; Geiger method in which gears are shaped by formed probe. { ¦gı ¯ иgər myu ¨ lиər pro ¯ b} grinding wheels and by generation; primarily a Geiger probe See Geiger-Mu ¨ ller probe. { gı ¯ иgər finishing operation. { gir grı ¯ ndиiŋ } pro ¯ b} gear hobber [ MECH ENG ] A machine that mills Geissler pump [ ENG ] A type of air pump that gear teeth; the rotational speed of the hob has uses the principle of the Torricellian vacuum, a precise relationship to that of the work. { gir and in which the vacuum is produced by the flow ha ¨ bиər} of mercury back and forth between a vertically gearing [ MECH ENG ] A set of gear wheels. adjustable and a fixed reservoir. { gı ¯ sиlər { girиiŋ } pəmp } gearing chain [ MECH ENG ] A continuous chain gelatinize [ ENG ] To coat or treat with a solution used to transmit motion from one toothed of gelatin. { jəlatиənı ¯ z} wheel, or sprocket, to another. { girиiŋcha ¯ n} gelation time [ CHEM ENG ] In the manufacture gearless traction [ MECH ENG ] Direct drive, of a thermosetting resin, the time interval be- without reduction gears. { ¦girиləs trakиshən} tween the addition of the catalyst into a liquid gear level [ MECH ENG ] To arrange gears so that adhesive system and the formation of a gel. the driven part and driving part turn at the same {jəla ¯ иshən tı ¯ m} speed. { gir levиəl} GEM See air-cushion vehicle. gear loading [ MECH ENG ] The power transmit- gender [ ELEC ] The classification of a connector ted or the contact force per unit length of a gear. as female or male. { jenиdər} { gir lo ¯ dиiŋ } gender changer [ ELEC ] A small passive device gear meter [ ENG ] A type of positive-displace- that is placed between two connectors of the ment fluid quantity meter in which the rotating same gender to enable them to be joined. Also elements are two meshing gear wheels. { gir known as cable matcher. { jenиdər cha ¯ nиjər} me ¯ dиər} generalized coordinates [ MECH ] A set of vari- gearmotor [ MECH ENG ] A motor combined with ables used to specify the position and orienta- a set of speed-reducing gears. { girmo ¯ dиər} tion of a system, in principle defined in terms gear pump [ MECH ENG ] A rotary pump in which of Cartesian coordinates of the system’s particles two meshing gear wheels contrarotate so that and of the time in some convenient manner; the the fluid is entrained on one side and discharged number of such coordinates equals the number on the other. { gir pəmp } of degrees of freedom of the system Also known gear ratio [ MECH ENG ] The ratio of the angular as Lagrangian coordinates. { jenиrəlı ¯ zd ko ¯ speed of the driving member of a gear train or o ˙ rdиənиəts } similar mechanism to that of the driven member; generalized force [ MECH ] The generalized specifically, the number of revolutions made by force corresponding to a generalized coordinate the engine per revolution of the rear wheels of is the ratio of the virtual work done in an infini- an automobile. { gir ra ¯ иsho ¯ } tesimal virtual displacement, which alters that gear shaper [ MECH ENG ] A machine that makes coordinate and no other, to the change in the gear teeth by means of a reciprocating cutter that coordinate. { jenиrəlı ¯ zd fo ˙ rs } rotates slowly with the work. { gir sha ¯ pиər} generalized momentum See conjugate momen- gear-shaving machine [ MECH ENG ] A finishing tum. { jenиrəlı ¯ zd məmentиəm} machine that removes excess metal from ma- generalized velocity [ MECH ] The derivative chined gears by the axial sliding motion of a with respect to time of one of the generalized straight-rack cutter or a circular gear cutter. coordinates of a particle. Also known as La- { gir sha ¯ vиiŋ məshe ¯ n} grangian generalized velocity. { jenиrəlı ¯ zd və gearshift [ MECH ENG ] A device for engaging la ¨ sиədиe ¯ } and disengaging gears. { girshift } general manager [ IND ENG ] The person of gen- gear teeth [ DES ENG ] Projections on the cir- eral authority who performs all reasonable tasks in conducting the usual and customary businesscumference or face of a wheel which engage with 246 get of the principal head or owner. { ¦jenиrəl manи conductive seawater by the magnetic field of the earth. { ¦je ¯ иo ¯ иmag¦nedиik i¦lekиtrəиkənedиəəиjər} generating magnetometer [ ENG ] A magnetom- graf } geomembrane [ CIV ENG ] Any impermeableeter in which a coil is rotated in the magnetic field to be measured with the resulting generated membrane (usually made of synthetic polymers in sheets) used with soils, rock, earth, or othervoltage being proportional to the strength of the magnetic field. { jenиəra ¯ dиiŋ magиnəta ¨ mиədи geotechnical material in order to block the mi- gration of fluids. { je ¯ иo ¯ membra ¯ n}ər} generating plant See generating station. { jenи geometric construction [ ENG ] Construction that employs only straightedge and compassesəra ¯ dиiŋplant } generating station [ MECH ENG ] A stationary or is carried out by drawing only straight lines and circles. { ¦je ¯ иə¦meиtrik kənstrəkиshən}plant containing apparatus for large-scale con- version of some form of energy (such as hydrau- geometric programming [ SYS ENG ] A nonlinear programming technique in which the relativelic, steam, chemical, or nuclear energy) into elec- trical energy. Also known as generating plant; contribution of each of the component costs is first determined; only then are the variables inpower station. { jenиəra ¯ dиiŋsta ¯ иshən} generation rate [ ELECTR ] In a semiconductor, the component costs determined. { ¦je ¯ иə¦meи trik pro ¯ gramиiŋ }the time rate of creation of electron-hole pairs. { jenиəra ¯ иshən ra ¯ t} geophysical engineering [ ENG ] A branch of en- gineering that applies scientific methods for lo- generator [ ELEC ] A machine that converts me- chanical energy into electrical energy; in its com- cating mineral deposits. { ¦je ¯ иə¦fizиəиkəl enи jənirиiŋ }monest form, a large number of conductors are mounted on an armature that is rotated in a geophysical prospecting [ ENG ] Application of quantitative concepts and principles of physicsmagnetic field produced by field coils. Also known as dynamo; electric generator. and mathematics in geologic explorations to dis- cover the character of and mineral resources in [ ELECTR ] 1. A vacuum-tube oscillator or any other nonrotating device that generates an alter- underground rocks in the upper portions of the earth’s crust. { ¦je ¯ иə¦fizиəиkəl pra ¨ spekиtiŋ }nating voltage at a desired frequency when ener- gized with direct-current power or low-frequency geosynthetic [ CIV ENG ] Any synthetic material used in geotechnical engineering, such as geo-alternating-current power. 2. A circuit that gen- erates a desired repetitive or nonrepetitive textiles and geomembranes. { je ¯ иo ¯ иsinthedи ik }waveform, such as a pulse generator. { jenи əra ¯ dиər} geotechnics [ CIV ENG ] The application of sci- entific methods and engineering principles to generator set [ ENG ] The aggregate of one or more generators together with the equipment civil engineering problems through acquiring, in- terpreting, and using knowledge of materials ofand plant for producing the energy that drives them. { jenиəra ¯ dиər set } the crust of the earth. { ¦je ¯ иo ¯ ¦tekиniks } geotechnology [ ENG ] Application of the meth- geochemical prospecting [ ENG ] The use of geochemical and biogeochemical principles and ods of engineering and science to exploitation of natural resources. { ¦je ¯ иo ¯ иtekna ¨ lиəиje ¯ }data in the search for economic deposits of min- erals, petroleum, and natural gases. { ¦je ¯ и geotextiles [ CIV ENG ] Woven or nonwoven fab- rics used with foundations, soils, rock, earth, oro ¯ ¦kemиəиkəl pra ¨ spekиting } geochemical well logging [ ENG ] Well logging other geotechnical material as an integral part of a manufactured project, structure, or system.dependent on geochemical analysis of the data. { ¦je ¯ иo ¯ ¦kemиəиkəl wel la ¨ gиiŋ } Also known as civil engineering fabrics; erosion control cloth; filter fabrics; support membranes. geodetic survey [ ENG ] A survey in which the figure and size of the earth are considered; it is { ¦je ¯ иo ¯ ¦tekstı ¯ lz } geothermal prospecting [ ENG ] Exploration forapplicable for large areas and long lines and is used for the precise location of basic points sources of geothermal energy. { ¦je ¯ иo ¯ ¦thərиməl pra ¨ spekиtiŋ }suitable for controlling other surveys. { ¦je ¯ и ə¦dedиik sərva ¯ } geothermal well logging [ ENG ] Measurement of the change in temperature of the earth by geographical mile [ MECH ] The length of 1 min- ute of arc of the Equator, or 6087.08 feet (1855.34 means of well logging. { ¦je ¯ иo ¯ ¦thərиməl wel la ¨ gиiŋ }meters), which approximates the length of the nautical mile. { ¦je ¯ иə¦grafиəиkəl mı ¯ l} geothermometer [ ENG ] A thermometer con- structed to measure temperatures in boreholes geologic thermometer See geothermometer. { ¦je ¯ и ə¦la ¨ jиik thərma ¨ mиədиər } or deep-sea deposits. { ¦je ¯ иo ¯ иthərma ¨ mиədиər} gerber beam [ CIV ENG ] A long, straight beam geolograph [ ENG ] A device that records the penetration rate of a bit during the drilling of a that functions essentially as a cantilevered beam by the insertion of two hinges in alternate spans.well. { je ¯ a ¨ lиəgraph } geomagnetic electrokinetograph [ ENG ] An in- { gərиbər be ¯ m} get [ IND ENG ] A combination of two or more ofstrument that can be suspended from the side of a ship to measure the direction and speed of the elemental motions of search, select, grasp, transport empty, and transport loaded; appliedocean currents while the ship is under way by measuring the voltage induced in the moving to time-motion studies. { get } 247 getter-ion pump getter-ion pump [ ENG ] A high-vacuum pump Gilbreth’s micromotion study [ IND ENG ] A time that employs chemically active metal layers and motion study based on the concept that all which are continuously or intermittently depos- work is performed by using a relatively few basic ited on the wall of the pump, and which chemi- operations in varying combinations and se- sorb active gases while inert gases are ‘‘cleaned quence; basic elements (therbligs) include grasp, up’’ by ionizing them in an electric discharge and search, move, reach, and hold. { gilиbrəths ¦mı ¯ и drawing the positive ions to the wall, where the kro ¯ ¦mo ¯ иshən stədиe ¯ } neutralized ions are buried by fresh deposits of gill [ MECH ] 1. A unit of volume used in the metal. Also known as sputter-ion pump. United States for the measurement of liquid sub- { ¦gedиər ¦ı ¯ a ¨ n pəmp } stances, equal to 1/4 U.S. liquid pint, or to getter sputtering [ ELECTR ] The deposition of 1.1829411825 ϫ 10 Ϫ4 cubic meter. 2. A unit of high-purity thin films at ordinary vacuum levels volume used in the United Kingdom for the by using a getter to remove contaminants re- measurement of liquid substances, and occa- maining in the vacuum. { gədиər spədиəиriŋ } sionally of solid substances, equal to 1/4 U.K. gewel hinge [ DES ENG ] A hinge consisting of a pint, or to approximately 1.420653125 ϫ 10 Ϫ4 hook inserted in a loop. { ju ¨ иəl hinj } cubic meter. { gil } gf See gram-force. Gilliland correlation [ CHEM ENG ] Approxima- Giaque’s temperature scale [ THERMO ] The in- tion method for distillation-column calculations; ternationally accepted scale of absolute temper- correlates reflux ratio and number of plates for ature, in which the triple point of water is defined the column as functions of minimum reflux and to have a temperature of 273.16 K. { ¦zhya ¨ ks minimum plates. { gəlilиənd ka ¨ иrəla ¯ иshən} temиprəиchər ska ¯ l} gill net [ ENG ] A net that entangles the gill cov- gib [ ENG ] A removable plate designed to hold ers of fish. { gil net } other parts in place or act as a bearing or wear Gilmour heat-exchange method [ ENG ] Ther- surface. { gib } mal design method for heat exchangers by solu- Gibbs apparatus [ ENG ] A compressed-oxygen tion of five unique equations containing a mini- breathing apparatus used by miners in the mum number of variables and involving tube- United States. { gibz apиəradиəs} side, shell-side, tube-wall, and dirt resistance. Gibbs diaphragm cell [ CHEM ENG ] A type of { gilиmo ˙ r he ¯ t ikscha ¯ nj methиəd} electrolytic diaphragm cell for chlorine produc- gimbal [ ENG ] 1. A device with two mutually per- tion, with graphite electrodes and a cylindrical pendicular and intersecting axes of rotation, thus shape. { gibz dı ¯ иəfram sel } giving free angular movement in two directions, Gibbs free energy [ THERMO ] The thermody- on which an engine or other object may be namic function G ϭ H Ϫ TS, where H is enthalpy, mounted. 2. In a gyro, a support which provides T absolute temperature, and S entropy. Also the spin axis with a degree of freedom. 3. To known as free energy; free enthalpy; Gibbs func- move a reaction engine about on a gimbal so as tion. { gibz ¦fre ¯ enиərиje ¯ } to obtain pitching and yawing correction mo- Gibbs function See Gibbs free energy. { gibz ments. 4. To mount something on a gimbal. fəŋkиshən} { gimиbəl} Gibbs-Helmholtz equation [ THERMO ] 1. Either gimbaled nozzle [ MECH ENG ] A nozzle sup- of two thermodynamic relations that are useful ported on a gimbal. { gimиbəld na ¨ zиəl} in calculating the internal energy U or enthalpy gimbal freedom [ ENG ] Of a gyro, the maximum H of a system; they may be written U ϭ angular displacement about the output axis of F Ϫ T(ѨF/ѨT) V and H ϭ G Ϫ T(ѨG/ѨT) P , where F a gimbal. { gimиbəl fre ¯ иdəm} is the free energy, G is the Gibbs free energy, T gimbal lock [ ENG ] A condition of a two-degree- is the absolute temperature, V is the volume, of-freedom gyro wherein the alignment of the and P is the pressure. 2. Any of the similar spin axis with an axis of freedom deprives the equations for changes in thermodynamic poten- gyro of a degree-of-freedom and therefore its tials during an isothermal process. { gibz hel- useful properties. { gimиbəl la ¨ k} mho ¯ lts ikwa ¯ иzhən} gimlet [ DES ENG ] A small tool consisting of a Giegy-Hardisty process [ CHEM ENG ] The pro- threaded tip, grooved shank, and a cross handle; duction of sebacic acid from castor oil or its acids used for boring holes in wood. { gimиlət} by reaction of the acid at a high temperature with gimlet bit [ DES ENG ] A bit with a threaded point caustic alkali. { ge ¯ иge ¯ ha ¨ rиdəиste ¯ pra ¨ sиəs} and spiral flute; used for drilling small holes in Giesler coal test [ ENG ] A plastometric method wood. { gimиlət bit } for estimating the coking properties of coals. gin [ MECH ENG ] A hoisting machine in the form { ge ¯ sиlər ko ¯ l test } of a tripod with a windlass, pulleys, and ropes. Gilbrethian variables [ IND ENG ] A system of { jin } three sets of variables that are considered to be gin pole [ MECH ENG ] A hand-operated derrick intrinsic to every task: variables involving the which has a nearly vertical pole supported by guy response of the worker to anatomic and psycho- ropes; the load is raised on a rope that passes logical factors, environmental variables, and through a pulley at the top and over a winch at variables of motion; used in analyzing and de- the foot. Also known as guyed-mast derrick; signing work systems. { gilbrethиe ¯ иən verиe ¯ и əиbəlz } pole derrick; standing derrick. { jin po ¯ l} 248 [...]... [BUILD] 1 The external angle formed by the junction of two sloping roofs or the sides of a roof 2 A rafter that is positioned at the junction of two sloping roofs or the sides of a roof [CIV ENG] See hip joint { hip } HIP See hot isostatic pressing { hip or ¦ach¦ı pe } ¯ ¯ ¯ hip joint [CIV ENG] The junction of an inclined head post and the top chord of a truss Also known as hip { hip joint } ˙ hi pot... əv i vapиə raиshən } ¯ ¯ heat of fusion [THERMO] The increase in enthalpy accompanying the conversion of 1 mole, or a unit mass, of a solid to a liquid at its melting point at constant pressure and temperature Also known as latent heat of fusion { het əv ¯ ¨ fyuиzhən } heat of mixing [THERMO] The difference between the enthalpy of a mixture and the sum of the enthalpies of its components at the same... heat of transformation [THERMO] The increase in enthalpy of a substance when it undergoes some phase change at constant pressure and temperature { het əv tranzиfər maиshən } ¯ ¯ heat of vaporization [THERMO] The quantity of energy required to evaporate 1 mole, or a unit mass, of a liquid, at constant pressure and temperature Also known as enthalpy of vaporization; heat of evaporation; latent heat of. .. } ¯ ¯ ¯ heat of wetting [THERMO] 1 The heat of adsorption of water on a substance 2 The additional heat required, above the heat of vaporization of free water, to evaporate water from a substance in which it has been absorbed { het ¯ əv wedиiŋ } heat pipe [ENG] A heat-transfer device consisting of a sealed metal tube with an inner lining of wicklike capillary material and a small amount of fluid in... specified datum level 2 In spirit leveling, the vertical distance from datum to line of sight of the instrument 3 In stadia leveling the height of center of transit above the station stake 4 In differential leveling, the elevation of the line of sight of the telescope when the instrument is leveled { hıt əv ¯ inиstrəиmənt } height of transfer unit [CHEM ENG] A dimensionless parameter used to calculate countercurrent... Metal flashing placed at the edge of a roof to prevent gravel from falling off { gravиəl stap } ¨ graveyard shift [IND ENG] The shift of workers that begins at or around midnight; the last shift of the day { grav yard shift } ¯ ¨ gravimeter [ENG] A highly sensitive weighing device used for relative measurement of the force of gravity by detecting small weight differences of a constant mass at different... making paper pulp by alkaline oxidation of extremely thin wood chips at low temperature and pressure and then solubilization of the lignin fraction { ¦halиo pəlиpiŋ prasиəs } ¨ ¯ ¨ Holzer’s method [MECH] A method of determining the shapes and frequencies of the torsional modes of vibration of a system, in which one imagines the system to consist of a number of flywheels on a massless flexible shaft... [MECH] A function of the generalized coordinates and momenta of a system, equal in value to the sum over the coordinates of the product of the generalized momentum corresponding to the coordinate, and the coordinate’s time derivative, minus the Lagrangian of the system; it is numerically equal to the total energy if the Lagrangian does not depend on time explicitly; the equations of motion of the system... ENG] 1 To prepare a roadway or other land surface of uniform slope 2 A surface prepared for the support of rails, a road, or a conduit 3 The elevation of the finished surface of an engineering project [ENG] The degree of strength of a high explosive { grad } ¯ gradeability [MECH ENG] The performance of earthmovers on various inclines, measured in percent grade { gradиə bilиədиe } ¯ ¯ grade beam [CIV... measure angle of inclination in terms of the tangent of the angle { gradи ¯ e enиtər } ¯ gradient microphone [ENG ACOUS] A microphone whose electrical response corresponds to some function of the difference in pressure between two points in space { gradиeиənt mıи ¯ ¯ ¯ krə fon } ¯ grading [IND ENG] Segregating a product into a number of adjoining categories which often form a spectrum of quality Also . logging [ ENG ] Measurement of the change in temperature of the earth by geographical mile [ MECH ] The length of 1 min- ute of arc of the Equator, or 60 87.08 feet (1855.34 means of well logging. { ¦je ¯ иo ¯ ¦thərиməl. response of audio equipment to be edge of a roof to prevent gravel from falling off. { gravиəl sta ¨ p}modified independently in several frequency bands through the use of a bank of slide controls graveyard. period of time, is the sum over the circuit in which one signal, generally a square points of the product of the mass of the point wave, serves to switch another signal on and times the square of