1. Trang chủ
  2. » Kỹ Thuật - Công Nghệ

Dictionary of Engineering Episode 2 Part 7 potx

25 409 0

Đang tải... (xem toàn văn)

Tài liệu hạn chế xem trước, để xem đầy đủ mời bạn chọn Tải xuống

THÔNG TIN TÀI LIỆU

Thông tin cơ bản

Định dạng
Số trang 25
Dung lượng 273,41 KB

Nội dung

oxo process oxo process [ CHEM ENG ] Catalytic process for atomized kerosine for combustion. { a ¨ kиsəиjən kerиəse ¯ n bərnиər}production of alcohols, aldehydes, and other ox- ygenated organic compounds by reaction of ole- oxygen mask [ ENG ] A mask that covers the fin vapors with carbon monoxide and hydrogen. nose and mouth and is used to administer oxy- { a ¨ kиso ¯ pra ¨ иsəs} gen. { a ¨ kиsəиjən mask } oxyacetylene cutting [ ENG ] The flame cutting oxygen point [ THERMO ] The temperature at of ferrous metals in which the preheating of the which liquid oxygen and its vapor are in equilib- metal is accomplished with a flame produced by rium, that is, the boiling point of oxygen, at an oxyacetylene torch. Also known as acetylene standard atmospheric pressure; it is taken as a cutting. { ¦a ¨ kиse ¯ иəsedиəle ¯ n ¦kədиiŋ } fixed point on the International Practical Temper- oxyacetylene torch [ ENG ] A torch that mixes ature Scale of 1968, at Ϫ182.962ЊC. { a ¨ kиsəи acetylene and oxygen to produce a hot flame for jən po ˙ int } the welding or cutting of metal. Also known as oxyl process [ CHEM ENG ] Modified Fischer- acetylene torch. { ¦a ¨ kиse ¯ иəsedиəle ¯ n ¦to ˙ rch } Tropsch process used to make alcohols, other oxyamination See ammoxidation. { ¦a ¨ kиse ¯ amи oxygenated compounds, paraffins, and olefin hy- əna ¯ иshən} drocarbons from carbon monoxide and hydro- oxygen bomb calorimeter [ ENG ] Device to gen. { a ¨ kиsəl pra ¨ иsəs} measure heat of combustion; the sample is oz See ounce. burned with oxygen in a closed vessel, and the oz ap See ounce. temperature rise is noted. { a ¨ kиsəиjən ba ¨ m oz apoth See ounce. kalиərimиədиər} ozone generator [ ENG ] Apparatus that con- oxygen cutting [ ENG ] Any of several types of verts oxygen, O 2 , into ozone, O 3 , by subjecting cutting processes in which metal is removed with the oxygen to an electric-brush discharge. Also or without a flux by a chemical reaction of the known as ozonizer. { o ¯ zo ¯ n jenиəra ¯ dиər} base metal with oxygen at high temperatures. ozonizer See ozone generator. { o ¯ zo ¯ nı ¯ zиər} { a ¨ kиsəиjən kədиiŋ } oz t See ounce. oxygen-kerosine burner [ ENG ] Liquid-fuel de- oz tr See ounce. vice using a mixture of oxygen and vaporized or 388 P hole being grouted to prevent return of the grout Pa See pascal. around the injection pipe. { pakиər} pace rating See effort rating. { pa ¯ s ra ¯ dиiŋ } packing [ ENG ] See stuffing. [ ENG ACOUS ] pachimeter [ ENG ] An instrument for measuring Excessive crowding of carbon particles in a car- the limit beyond which shear of a solid ceases bon microphone, produced by excessive pres- to be elastic. { pəkimиədиər} sure or by fusion particles due to excessive cur- Pachuca tank [ CHEM ENG ] Air-agitated, solid- rent, and causing lowered resistance and sensi- liquid mixing vessel in which the air is injected tivity. { pakиiŋ } into the bottom of a center draft tube; air and packing density [ ELECTR ] The number of de- solids rise through the tube, with solids exiting vices or gates per unit area of an integrated cir- the top of the tube and falling through the bulk cuit. { pakиiŋdenиsədиe ¯ } of the liquid. { pəchu ¨ иkətaŋk} packing ring See piston ring. { pakиiŋriŋ } pachymeter [ ENG ] An instrument used to pad [ ELECTR ] 1. An arrangement of fixed resis- measure the thickness of a material, for example, tors used to reduce the strength of a radio-fre- a sheet of paper. { pəkimиədиər} quency or audio-frequency signal by a desired pack [ IND ENG ] To provide protection for an ar- fixed amount without introducing appreciable ticle or group of articles against physical damage distortion. Also known as fixed attenuator. during shipment; packing is accomplished by 2. See terminal area. [ ENG ] 1. A layer of mate- placing articles in a shipping container, and rial used as a cushion or for protection. 2. A blocking, bracing, and cushioning them when projection of excess metal on a casting forging, necessary, or by strapping the articles or contain- or welded part. 3. An area within an airstrip or ers on a pallet or skid. { pak } airway that is used for warming up the motors packaged circuit See rescap. { pakиijd ¦sərиkət} of an airplane before takeoff. 4. A block of stone package freight [ IND ENG ] Freight shipped in or masonry set on a wall to distribute a load lots insufficient to fill a complete car; billed by that is concentrated at that portion of the wall. the unit instead of by the carload. { pakиij Also known as padstone. 5. That portion of an fra ¯ t} airstrip or airway from which an airplane leaves packaging [ ELEC ] The process of physically the ground on takeoff or first touches the ground locating, connecting, and protecting devices or on landing. 6. See helipad. { pad } components. { pakиəиjiŋ } paddle [ DES ENG ] Any of various implements packaging density [ ELECTR ] The number of consisting of a shaft with a broad, flat blade or components per unit volume in a working system bladelike part at one or both ends. { padиəl} or subsystem. { pakиəиjiŋdenиsədиe ¯ } paddle wheel [ MECH ENG ] 1. A device used to packed bed [ CHEM ENG ] A fixed layer of small propel shallow-draft vessels, consisting of a particles or objects arranged in a vessel to pro- wheel with paddles or floats on its circumfer- mote intimate contact between gases, vapors, ence, the wheel rotating in a plane parallel to liquids, solids, or various combinations thereof; the ship’s length. 2. A wheel with paddles used used in catalysis, ion exchange, sand filtration, to move leather in a processing vat. { padиəl distillation, absorption, and mixing. { pakt we ¯ l} bed } padlock [ DES ENG ] An unmounted lock with a packed tower [ CHEM ENG ] A fractionating or shackle that can be opened and closed; the absorber tower filled with small objects (pack- shackle is usually passed through an eye, then ing) to bring about intimate contact between closed to secure a hasp. { padla ¨ k} rising fluid (vapor or liquid) and falling liquid. pail [ DES ENG ] A cylindrical or slightly tapered { pakt tau ˙ иər} container. { pa ¯ l} packed tube [ CHEM ENG ] A pipe or tube filled pair [ ELEC ] Two like conductors employed to with high-heat-capacity granular material; used form an electric circuit. [ MECH ENG ] Two to heat gases when tubes are externally heated. parts in a kinematic mechanism that mutually { pakt tu ¨ b} constrain relative motion; for example, a sliding pair composed of a piston and cylinder. { per } packer [ ENG ] A device that is inserted into a Copyright 2003 by The McGraw-Hill Companies, Inc. Click Here for Terms of Use. pairing element pairing element [ MECH ENG ] Either of two ma- wall panels of the space which is to be heated. { panиəl he ¯ dиiŋ } chine parts connected to permit motion. { perи panel length [ CIV ENG ] The distance between iŋelиəиmənt } adjacent joints on a truss, measured along the palladium barrier leak detector [ ENG ] A type of upper or lower chord. { panиəl leŋkth } leak detector in which hydrogen is diffused panel point [ CIV ENG ] The point in a framed through a barrier of hot palladium into an evacu- structure where a vertical or diagonal member ated vacuum gage. { pəla ¯ dиe ¯ иəm barиe ¯ иər le ¯ k and a chord intersect. { panиəl po ˙ int } ditekиtər} panel system [ BUILD ] A wall composed of fac- pallet [ BUILD ] A flat piece of wood laid in a wall tory-assembled units connected to the building to which woodwork may be securely fastened. frame and to each other by means of anchors. [ ENG ] 1. A lever that regulates or drives a { panиəl sisиtəm} ratchet wheel. 2. A hinged valve on a pipe panel wall [ BUILD ] A nonbearing partition be- organ. 3. A tray or platform used in conjunction tween columns or piers. { panиəl wo ˙ l} with a fork lift for lifting and moving materials. pan head [ DES ENG ] The head of a screw or rivet [ MECH ENG ] One of the disks or pistons in a in the shape of a truncated cone. { pan hed } chain pump. { palиət} panic exit device [ ENG ] A locking device in- palletize [ IND ENG ] To package material for con- stalled on an exit door to release the latch when venient handling on a pallet or lift truck. the crash bar is pushed. Also known as fire- { palиətı ¯ z} exit bolt; panic hardware. { ¦panиik ¦egиzit pall ring [ CHEM ENG ] A specially shaped steel divı ¯ s} ring used as packing for distillation columns. panic hardware See panic exit device. { panиik { po ˙ l riŋ } ha ¨ rdwer } palpable coordinate [ MECH ] A generalized co- pannier See gabion. { panиyər} ordinate that appears explicitly in the Lagran- panoramic radar [ ENG ] Nonscanning radar gian of a system. { palиpəиbəlko ¯ o ˙ rdиənиət} which transmits signals over a wide beam in the pan bolt [ DES ENG ] A bolt with a head resem- direction of interest. { ¦panиə¦ramиik ra ¯ da ¨ r} bling an upside-down pan. { pan bo ¯ lt } pan tank See rundown tank. { pan taŋk} pancake auger [ DES ENG ] An auger having one pantograph [ ENG ] A device that sits on the top spiral web, 12 to 15 inches (30 to 38 centimeters) of an electric locomotive or cars in an electric in diameter, attached to the bottom end of a train and picks up electricity from overhead wires slender central shaft; used as removable dead- to run the train. { panиtəgraf } man to which a drill rig or guy line is anchored. pantography [ ENG ] System for transmitting { panka ¯ k ¦o ˙ gиər} and automatically recording radar data from an pancake engine [ MECH ENG ] A compact engine indicator to a remote point. { panta ¨ gиrəиfe ¯ } with cylinders arranged radially. { panka ¯ k pantometer [ ENG ] An instrument that meas- ¦enиjən} ures all the angles necessary for determining pan conveyor [ MECH ENG ] A conveyor con- distances and elevations. { panta ¨ mиədиər} sisting of a series of pans. { pan kənva ¯ иər} paper cutter [ DES ENG ] A hand-operated device pan crusher [ MECH ENG ] Solids-reduction de- to cut and trim paper, consisting of a cutting vice in which one or more grinding wheels or blade bolted at one end to a ruled board; when mullers revolve in a pan containing the material the blade is drawn flush with the board, which to be pulverized. { pan krəshиər} has a metal strip at the cutting edge, a shearing pane [ BUILD ] A sheet of glass in a window or action takes place which cuts the paper cleanly door. [ DES ENG ] One of the sides on a nut or and evenly. { pa ¯ иpər kədиər} on the head of a bolt. { pa ¯ n} paper machine [ MECH ENG ] A synchronized se- panel [ CIV ENG ] 1. One of the divisions of a ries of mechanical devices for transforming a lattice girder. 2. A sheet of material held in a dilute suspension of cellulose fibers into a dry frame. 3. A distinct, usually rectangular, raised sheet of paper. { pa ¯ иpərməshe ¯ n} or sunken part of a construction surface or a paper mill [ IND ENG ] A building or complex of material. [ DES ENG ] See frog. [ ENG ] A me- buildings housing paper machines. { pa ¯ иpər tallic or nonmetallic sheet on which operating mil } controls and dials of an electronic unit or other parabolic microphone [ ENG ACOUS ] A micro- equipment are mounted. { panиəl} phone used at the focal point of a parabolic panel board [ ELEC ] See control board. [ ENG ] sound reflector to give improved sensitivity and A drawing board with an adjustable outer frame directivity, as required for picking up a band that is forced over the drawing paper to hold marching down a football field. { ¦parиə¦ba ¨ lиik and strain it. { panиəl bo ˙ rd } mı ¯ иkrəfo ¯ n} panel coil See plate coil. { panиəl ko ˙ il } paraboloid [ ENG ] A reflecting surface which is panel cooling [ CIV ENG ] A system in which the a paraboloid of revolution and is used as a reflec- heat-absorbing units are in the ceiling, floor, or tor for sound waves and microwave radiation. wall panels of the space which is to be cooled. {pərabиəlo ˙ id } { panиəl ku ¨ lиiŋ } parabomb [ ENG ] An equipment container with panel heating [ CIV ENG ] A system in which the a parachute which is capable of opening auto- matically after a delayed drop. { parиəba ¨ m}heat-emitting units are in the ceiling, floor, or 390 parametrized voice response system paracentric [ DES ENG ] Pertaining to a key and to another in an electric network over multiple paths, in accordance with Kirchhoff’s laws.keyway with longitudinal ribs and grooves that project beyond the center, as used in pin-tumbler 2. In particular, the flow of electric current through electric power systems over paths othercylinder locks to deter lockpicking. { ¦parи ə¦senиtrik } than the contractual path. { parиəlel flo ¯ } parallel gripper [ CONT SYS ] A robot end effector parachute flare [ ENG ] Pyrotechnic device attached to a parachute and designed to provide made up of two jawlike components that grasp objects. { parиəlel gripиər}intense illumination for a short period; it may be discharged from aircraft or from the surface. parallel linkage [ MECH ENG ] An automotive steering system that has a short idler arm{ parиəshu ¨ t fler } parachute radiosonde See dropsonde. { ¦parи mounted parallel to the pitman arm. { ¦parиəlel liŋиkij }əshu ¨ t ra ¯ dиe ¯ sa ¨ nd } parachute weather buoy [ ENG ] A general-pur- parallel-plate reactor [ ENG ] A type of plasma reactor in which a process gas is introduced intopose automatic weather station which can be air-dropped; it is 10 feet (3 meters) long and the space between two closely spaced parallel plane electrodes, and a plasma, generated by a22 inches (56 centimeters) in diameter, and is designed to operate for 2 months on a 6-hourly radio-frequency excitation applied to the elec- trodes, acts directly on substrates placed onschedule, transmitting station identification, wind speed, wind direction, barometric pressure, either electrode. { ¦parиəlel pla ¯ tre ¯ akиtər} parallel reliability [ SYS ENG ] Property of a sys-air temperature, and sea-water temperature. { parиəshu ¨ t wethиər bo ˙ i } tem composed of functionally parallel elements in such a way that if one of the elements fails, paracrate [ ENG ] Rigid equipment container for dropping equipment from an airplane by para- the parallel units will continue to carry out the system function. { parиəlel rilı ¯ иəbilиədиe ¯ }chute. { parиəkra ¯ t} paraffin press [ ENG ] A filter press used during parallels [ ENG ] 1. Spacers located between steam plate and press platen of the mold topetroleum refining for the separation of paraffin oil and crystallizable paraffin wax from distil- prevent bending of the middle section. 2. Spac- ers or pressure pods located between steamlates. { parиəиfən pres } parallel [ ELEC ] Connected to the same pair of plates of a mold to regulate height and prevent crushing of mold parts. { parиəlelz }terminals. Also known as multiple; shunt. { parиəlel } parallel series [ ELEC ] Circuit in which two or more parts are connected together in parallel to parallel axis theorem [ MECH ] A theorem which states that the moment of inertia of a body about form parallel circuits, and in which these circuits are then connected together in series so thatany given axis is the moment of inertia about a parallel axis through the center of mass, plus both methods of connection appear. [ ENG ] See multiple series. { parиəlel sirиe ¯ z}the moment of inertia that the body would have about the given axis if all the mass of the body parallel shot [ ENG ] In seismic prospecting, a test shot which is made with all the amplifierswere located at the center of mass. Also known as Steiner’s theorem. { parиəlel ¦akиsəs thirи connected in parallel and activated by a single geophone so that lead, lag, polarity, and phasingəm} parallel baffle muffler [ DES ENG ] A muffler con- in the amplifier-to-oscillograph circuits can be checked. { parиəlel sha ¨ t}structed of a series of ducts placed side by side in which the duct cross section is a narrow but parameter identification [ SYS ENG ] The prob- lem of estimating the values of the parameterslong rectangle. { parиəlel ¦bafиəl məfиlər} parallel circuit [ ELEC ] An electric circuit in that govern a dynamical system from data on the observed behavior of the system. { pəramиwhich the elements, branches (having elements in series), or components are connected between ədиərı ¯ dentиəиfəka ¯ иshən} parametric equalizer [ ENG ACOUS ] A devicetwo points, with one of the two ends of each component connected to each point. { parи that allows control over the center frequencies, bandwidths, and amplitudes (parameters) ofəlel sərиkət} parallel compensation See feedback compensa- band-pass filters that determine the frequency response of audio equipment. { ¦parиə¦meиtriktion. { parиəlel ka ¨ mиpənsa ¯ иshən} parallel cut [ ENG ] A group of parallel holes, not e ¯ иkwəlı ¯ zиər} parametric excitation [ ENG ] The method of ex-all charged with explosive, to create the initial cavity to which the loaded holes break in blasting citing and maintaining oscillations in either an electrical or mechanical dynamic system, ina development round. Also known as burn cut. { parиəlel kət } which excitation results from a periodic variation in an energy storage element in a system such as parallel drum [ DES ENG ] A cylindrical form of drum on which the haulage or winding rope is a capacitor, inductor, or spring constant. { ¦parи ə¦meиtrik ekиsita ¯ иshən}coiled. { parиəlel drəm} parallel firing [ ENG ] A method of connecting to- parametrized voice response system [ ENG ACOUS ] A voice response system which first ex-gether a number of detonators which are to be fired electrically in one blast. { parиəlel fı ¯ rиiŋ } tracts informative parameters from human speech, such as natural resonant frequencies parallel flow [ ELEC ] Also known as loop flow. 1. The flow of electric current from one point (formants) of the speaker’s vocal tract and the 391 parapack fundamental frequency (pitch) of the voice, and steam turbine having a reaction-type stage in which later reconstructs speech from such stored which the pressure drop occurs partially across parameters. { pəramиətrı ¯ zd vo ˙ is rispa ¨ ns the stationary nozzles and partly across the rotat- sisиtəm} ing blades. { pa ¨ rиsənz ¦sta ¯ j ste ¯ m tərиbən} parapack [ ENG ] A package or bundle with a part [ ENG ] An element of a subassembly, not parachute attached for dropping from an aircraft. normally useful by itself and not amenable to { parиəpak } further disassembly for maintenance purposes. parasitic [ ELECTR ] An undesired and energy- {pa ¨ rt } wasting signal current, capacitance, or other pa- part classification [ IND ENG ] A coding scheme rameter of an electronic circuit. { ¦parиə¦sidиik } employed in automated manfacturing processes parasitic current [ ELEC ] An eddy current in a that uses four or more digits to assign discrete piece of electrical machinery; gives rise to energy products to families of parts. { pa ¨ rt klasиəи losses. { ¦parиə¦sidиik kəиrənt } fəka ¯ иshən} paravane [ ENG ] A torpedo-shaped device with part detection [ IND ENG ] The recognition of sawlike teeth along its forward end, towed with parts and workpieces by a robot or a computer a wire rope underwater from either side of the vision system. { pa ¨ rt ditekиshən} bow of a ship to cut the cables of anchored part family [ IND ENG ] In the group technology mines. Also known as otter. { parиəva ¯ n} concept, a set of related parts that can be Pareto diagram [ IND ENG ] A histogram of de- produced by the same sequence of machining fects or quality problems, classified by type and operations because of similarity in shape and sorted in the order of descending frequency, that geometry or similarity in production operation is used to focus on the major sources of prob- processes. { pa ¨ rt famиle ¯ } lems. { pa ¨ reиto ¯ diиəgram } partial condensation [ CHEM ENG ] The cooling Pareto’s law [ IND ENG ] The principle that in (or pressurization) of a saturated vapor until a most activities a small fraction (around 20%) of part of it is condensed out as liquid. { pa ¨ rиshəl the total activity accounts for a large fraction ka ¨ ndиənsa ¯ иshən} (around 80%) of the result. Also known as rule particle See material particle. { pa ¨ rdиəиkəl} of 80-20. { pəre ¯ dиo ¯ z lo ˙ } particle dynamics [ MECH ] The study of the de- parging [ CIV ENG ] A thin coating of mortar or pendence of the motion of a single material par- plaster on a brick or stone surface. { pa ¨ rjиiŋ } ticle on the external forces acting upon it, partic- paring [ MECH ENG ] A method of wood turning ularly electromagnetic and gravitational forces. in which the piece is trimmed or reduced in size { pa ¨ rdиəиkəldı ¯ namиiks } by cutting or shaving thin sections from the sur- particle energy [ MECH ] For a particle in a po- face. { perиiŋ } tential, the sum of the particle’s kinetic energy paring chisel [ DES ENG ] A long-handled chisel and potential energy. { pa ¨ rdиəиkəl enиərиje ¯ } used to pare wood manually. { perиiŋchizиəl} particle image velocimetry [ ENG ] A method of paring gouge [ DES ENG ] A long, thin concave measuring local fluid velocities at thousands of woodworker’s gouge with the cutting edge bev- locations in a fluid flow by optically observing eled on the inside of the blade. { perиiŋgau ˙ j} large numbers of particles that are suspended parison [ ENG ] A hollow plastic tube from which in the fluid and move with it, using a photograph a bottle or other hollow object is blow-molded. of the flow illuminated by two or more successive { parиəиsən} pulses of light or continuously for a known time parison swell [ ENG ] In blow molding, the ratio interval. Also known as particle tracking velo- of the cross-sectional area of the parison to that cimetry. { pa ¨ rdиiиkəl imиij velиəsa ¨ mиəиtre ¯ } of the die opening. { parиəиsən swel } particle mechanics [ MECH ] The study of the parking apron [ CIV ENG ] A hard-surfaced area motion of a single material particle. { pa ¨ rdиəи used for parking aircraft. { pa ¨ rkиiŋa ¯ иprən} kəlmikanиiks } parking brake [ MECH ENG ] In an automotive particle-size analysis [ ENG ] Determination of vehicle, a brake that functions independently of the proportion of particles of a specified size in the service brake and is set after the vehicle has a granular or powder sample. { pa ¨ rdиəиkəl ¦sı ¯ z been brought to a stop. { pa ¨ rkиiŋbra ¯ k} ənalиəиsəs} parking lot [ CIV ENG ] An outdoor lot for parking particle-size distribution [ ENG ] The percent- automobiles. { pa ¨ rkиiŋla ¨ t} ages of each fraction into which a granular or parkway [ CIV ENG ] A broad landscaped ex- powder sample is classified, with respect to par- pressway which is not open to commercial vehi- ticle size, by number or weight. { pa ¨ rdиəиkəl cles. { pa ¨ rkwa ¯ } ¦sı ¯ z diиstrəbyu ¨ иshən} parquet flooring [ BUILD ] Wood flooring made particle tracking velocimetry See particle image of strips laid in a pattern to form designs. velocimetry. { ¦pa ¨ rdиəиkəl ¦trakиiŋvelиəsimиəи {pa ¨ rka ¯ flo ˙ rиiŋ } tre ¯ } Parshall flume [ ENG ] A calibrated device for particulate mass analyzer [ ENG ] A unit which measuring the flow of liquids in open conduits measures dust concentrations in emissions from by measuring the upper and lower beads at a furnaces, kilns, cupolas, and scrubbers. { pa ¨ r specified distance from an obstructing sill. tikиyəиlət mas anиəlı ¯ zиər} { pa ¨ rиshəl flu ¨ m} Parsons-stage steam turbine [ MECH ENG ] A parting stop [ BUILD ] A thin strip of wood that 392 patent separates the sashes in a double-hung window. bending or deforming of the manipulator com- ponents in response to forces exerted on the{ pa ¨ rdиiŋsta ¨ p} parting tool [ DES ENG ] A narrow-bladed hand robot. { pasиiv əka ¨ mиəda ¯ иshən} passive AND gate [ ELECTR ] See AND gate.tool with a V-shaped gouge used in woodworking for cutting grooves and in wood turning for cut- [ ENG ] A fluidic device which achieves an output signal, by stream interaction, only when bothting a piece in two. Also known as V-tool. { pa ¨ rdиiŋtu ¨ l } of two control signals appear simultaneously. { pasиiv and ga ¯ t} partition [ BUILD ] An interior wall having a height of one story or less, which divides a struc- passive component See passive element. { pasи iv kəmpo ¯ иnənt }ture into sections. [ IND ENG ] A slotted sheet of paperboard that can be assembled with simi- passive earth pressure [ CIV ENG ] The maxi- mum value of lateral earth pressure exerted bylar sheets to form cells for holding goods during shipment. { pa ¨ rtishиən } soil on a structure, occurring when the soil is compressed sufficiently to cause its internal part programming [ CONT SYS ] The planning and specification of the sequence of steps or shearing resistance along a potential failure sur- face to be completely mobilized. { pasиiv ərthevents in the operation of a numerically con- trolled machine tool. { pa ¨ rt pro ¯ gramиiŋ } preshиər} passive element [ ELEC ] An element of an elec- parts kit [ ENG ] A group of parts, not all having the same basic name, used for repair or replace- tric circuit that is not a source of energy, such as a resistor, inductor, or capacitor. Also knownment of the worn broken parts of an item; it may include instruction sheets and material, as passive component. { pasиiv elиəиmənt } passive method [ CIV ENG ] A constructionsuch as sandpaper, tape, cement, and gaskets. { pa ¨ rts kit } method in permafrost areas in which the frozen ground near the structure is not disturbed or parts list [ ENG ] One or more printed sheets showing a manufacturer’s parts or assemblies of altered, and the foundations are provided with additional insulation to prevent thawing of thean end item by illustration or a numerical listing of part numbers and names; it does not outline underlying ground. { pasиiv methиəd} passive radar [ ENG ] A technique for detectingany assembly, maintenance, or operating in- structions, and it may or may not have a price objects at a distance by picking up the microwave electromagnetic energy that is both radiated andlist cover sheet. { pa ¨ rts list } party wall [ BUILD ] A wall providing joint service reflected by all bodies. { pasиiv ra ¯ da ¨ r} passive radiator [ ENG ACOUS ] A loudspeakerbetween two buildings. { pa ¨ rdиe ¯ wo ˙ l} pascal [ MECH ] A unit of pressure equal to the driver with no voice-coil or magnet assemblies that is mounted in a box with a woofer and exhib-pressure resulting from a force of 1 newton acting uniformly over an area of 1 square meter. Sym- its a resonance that can be used to improve the low-frequency response of the system. { ¦pasиbolized Pa. { paskal } pass [ MECH ENG ] 1. The number of times that iv ra ¯ dиe ¯ a ¯ dиər} passive solar system [ MECH ENG ] A solar heat-combustion gases are exposed to heat transfer surfaces in boilers (that is, single-pass, double- ing or cooling system that operates by using gravity, heat flows, or evaporation rather thanpass, and so on). 2. In metal rolling, the pas- sage in one direction of metal deformed between mechanical devices to collect and transfer en- ergy. { pasиiv so ¯ иlər sisиtəm}rolls. 3. In metal cutting, transit of a metal cut- ting tool past the workpiece with a fixed tool passive sonar [ ENG ] Sonar that uses only un- derwater listening equipment, with no transmis-setting. { pas } passband [ ELECTR ] A frequency band in which sion of location-revealing pulses. { pasиiv so ¯ na ¨ r}the attenuation of a filter is essentially zero. { pasband } passive transducer [ ELECTR ] A transducer con- taining no internal source of power. { pasиiv pass-by [ ENG ] The double-track part of any sin- gle-track system of rail transport. { pasbı ¯ } tranzdu ¨ иsər} paste mixer [ ENG ] Device for the blending to- passenger car [ ENG ] 1. A railroad car in which passengers are carried. 2. An automobile for gether of solid particles and a liquid, with the final formation of a single paste phase. { pa ¯ stcarrying as many as nine passengers. { pasи ənиjər ka ¨ r} mikиsər} paste-up See mechanical. { pa ¯ stəp} passing track [ ENG ] A sidetrack with switches at both ends. { pasиiŋtrak } pasteurizer [ ENG ] An apparatus used for pas- teurization of fluids. { pasиchərı ¯ zиər} passivation [ ELECTR ] Growth of an oxide layer on the surface of a semiconductor to provide patch [ ELEC ] A temporary connection between jacks or other terminations on a patch board.electrical stability by isolating the transistor sur- face from electrical and chemical conditions in { pach } patch bolt [ DES ENG ] A bolt with a countersunkthe environment; this reduces reverse-current leakage, increases breakdown voltage, and raises head having a square knob that twists off when the bolt is screwed in tightly; used to repair boil-power dissipation rating. { pasиəva ¯ иshən} passive accommodation [ CONT SYS ] The alter- ers and steel ship hulls. { pach bo ¯ lt } patent [ IND ENG ] A certificate of grant by a gov-ation in the positioning or motion of the end point of a robot manipulator that results from ernment of an exclusive right with respect to 393 path computation an invention for a limited period of time. Also of solid substances, equal to 8 dry quarts, or 1/4 bushel, or 537.605 cubic inches, orknown as letters patent. { patиənt } path computation [ CONT SYS ] The calculations 0.00880976754172 cubic meter. 2. A unit of vol- ume used in the United Kingdom for measure-involved in specifying the trajectory followed by a robot. { path ka ¨ mиpyəta ¯ иshən } ment of solid and liquid substances, although usually the former, equal to 2 gallons, or pattern [ ENG ] A form designed and used as a model for making things. { padиərn } 0.00909218 cubic meter. { pek } Peclet number [ CHEM ENG ] Dimensionless pattern shooting [ ENG ] In seismic prospecting, firing of explosive charges arranged in geometric group used to determine the chemical reaction similitude for the scale-up from pilot-plant datapattern. { padиərn shu ¨ dиiŋ } pavement [ BUILD ] A hard floor of concrete, to commercial-sized units; incorporates heat ca- pacity, density, fluid velocity, and other pertinentbrick, tiles, or other material. [ CIV ENG ] A paved surface. { pa ¯ vиmənt } physical parameters. { pəkla ¯ nəmиbər} pedal [ DES ENG ] A lever operated by foot. pavement light [ CIV ENG ] A window built into the surface of a pavement to admit daylight to { pedиəl} pedestal [ CIV ENG ] 1. The support for a column.a space below ground level. { pa ¯ vиmənt lı ¯ t} paver [ MECH ENG ] Any of several machines 2. A metal support carrying one end of a bridge truss or girder and transmitting any load to thewhich, moving along the road, carry and lay pav- ing material. { pa ¯ vиər } top of a pier or abutment. [ ELECTR ] See blank- ing level. [ ENG ] A supporting part or the base pawl [ MECH ENG ] The driving link or holding link of a ratchet mechanism, permits motion in of an upright structure, such as a radar antenna. { pedиəstиəl}one direction only. { po ˙ l} payback period [ IND ENG ] The amount of time pedestal design [ MECH ENG ] A robot design centered on the vertical axis of a central pedestal,required for achieving an amount in profits to offset the cost of a capital expenditure, such as in which the motion of any workpiece is confined to a spherical working envelope. { pedиəstиəlthe cost of investment in modifications in an industrial facility for the purpose of conserving dizı ¯ n} pedestal flooring See raised flooring. { pedиəиenergy. { pa ¯ bak pirиe ¯ иəd} payout time [ IND ENG ] A measurement of prof- stəl flo ˙ rиiŋ } pedestal pile [ CIV ENG ] A concrete pile with aitability or liquidity of an investment, being the time required to recover the original investment bulbous enlargement at the bottom. { pedи əstиəl pı ¯ l}in depreciable facilities from profit and deprecia- tion; usually, but not always, calculated after in- pedometer [ ENG ] 1. An instrument for measur- ing and weighing a newborn child. 2. An instru-come taxes. { pa ¯ au ˙ t tı ¯ m} p-channel metal-oxide semiconductor See PMOS. ment that registers the number of footsteps and distance covered in walking. { pəda ¨ mиədиər}{ ¦pe ¯ chanиəl medиəl ¦a ¨ ksı ¯ d semиiиkəndəkиtər} p chart [ IND ENG ] A chart of the fraction defec- peel-back [ ENG ] The separation of two bonded materials, one or both of which are flexible, bytive, either observed in the sample or in some production period. { pe ¯ cha ¨ rt } stripping or pulling the flexible material from the mating surface at a 90 or 180Њ angle to the pdl-ft See foot-poundal. PDM See precedence diagram method. plane in which it is adhered. { pe ¯ l bak } peel-off time [ ENG ] In seismic prospecting, the PDR See precision depth recorder. peak load [ ELEC ] The maximum instantaneous time correction applied to observed data to ad- just them to a depressed reference datum.load or the maximum average load over a desig- nated interval of time. Also known as peak { pe ¯ l o ˙ f tı ¯ m} peel test [ ENG ] A test to ascertain the adhesivepower. [ ENG ] The maximum quantity of a specified material to be carried by a conveyor strength of bonded strips of metals by peeling or pulling the metal strips back and recordingper minute in a specified period of time. { pe ¯ k lo ¯ d } the adherence values. { pe ¯ l test } peen [ DES ENG ] The end of a hammer head with peak power See peak load. { pe ¯ k pau ˙ иər} Peaucellier linkage [ MECH ENG ] A mechanical a hemispherical, wedge, or other shape; used to bend, indent, or cut. { pe ¯ n}linkage to convert circular motion exactly into straight-line motion. { po ˙ selиya ¯ liŋиkij } peepdoor [ MECH ENG ] A small door in a fur- nace with a glass opening through which com- pebble heater [ CHEM ENG ] Gas-heating device (for air, hydrogen, methane, and steam) in which bustion may be observed. { pe ¯ pdo ˙ r} peg [ ENG ] 1. A small pointed or tapered piece,heat is transferred to the gas via a countercurrent movement of preheated pebbles. { pebиəl often cylindrical, used to pin down or fasten parts. 2. A projection used to hang or supporthe ¯ dиər} pebble mill [ MECH ENG ] A solids size-reduction objects. { peg } peg count meter [ ENG ] A meter or register thatdevice with a cylindrical or conical shell rotating on a horizontal axis, and with a grinding medium counts the number of trunks tested, the number of circuits passed busy, the number of test fail-such as balls of flint, steel, or porcelain. { pebи əl mil } ures, or the number of repeat tests completed. { peg kau ˙ nt me ¯ dиər} peck [ MECH ] Abbreviated pk. 1. A unit of vol- ume used in the United States for measurement PEL See permissible exposure limit. { pel } 394 Penning trap pellet cooler [ CHEM ENG ] Gas-cooled, gravity- pendulum press [ MECH ENG ] A punch press ac- tuated by a swinging treadle operated by the bed device for the cooling and drying of extruded foot. { penиjəиləm pres } pellets and briquets. { pelиət ku ¨ lиər} pendulum saw [ MECH ENG ] A circular saw that pelleting [ ENG ] Method of accelerating solidifi- swings in a vertical arc for crosscuts. { penиjəи cation of cast explosive charges by blending pre- ləm so ˙ } cast pellets of the explosives into the molten pendulum scale [ ENG ] Weight-measurement charge. { pelиədиiŋ } device in which the load is balanced by the move- pelletizer [ CHEM ENG ] A machine for cutting ment of one or more pendulums from vertical bulk plastic into pellets, suitable for use as feed- (zero weight) to horizontal (maximum weight). stock, either from solidified polymer at the end { penиjəиləm ska ¯ l} of the manufacturing process or from the molten pendulum seismograph [ ENG ] A seismograph polymer as it emerges from the die. { pelи that measures the relative motion between the ətı ¯ zиər} ground and a loosely coupled inertial mass; in pellet mill [ MECH ENG ] Device for injecting par- some instruments, optical magnification is used ticulate, granular or pasty feed into holes of a whereas others exploit electromagnetic trans- roller, then compacting the feed into a continu- ducers, photocells, galvanometers, and elec- ous solid rod to be cut off by a knife at the tronic amplifiers to achieve higher magnifica- periphery of the roller. { pelиət mil } tion. { penиjəиləm sı ¯ zиməgraf } Pelton turbine See Pelton wheel. { pelиtən tərи penetration ballistics [ MECH ] A branch of ter- bən} minal ballistics concerned with the motion and Pelton wheel [ MECH ENG ] An impulse hydrau- behavior of a missile during and after penetrat- lic turbine in which pressure of the water supply ing a target. { penиətra ¯ иshənbəlisиtiks } is converted into velocity by a few stationary penetration depth [ ELEC ] In induction heating, nozzles, and the water jets then impinge on the the thickness of a layer, extending inward from buckets mounted on the rim of a wheel; usually a conductor’s surface, whose resistance to direct limited to high head installations, exceeding 500 current equals the resistance of the whole con- feet (150 meters). Also known as Pelton tur- ductor to alternating current of a given frequency. bine. { pelиtən we ¯ l} [ ENG ] The greatest depth in an ultrasonic test pen [ ENG ] 1. A small place for confinement, piece at which indications can be measured. storage, or protection. 2. A device for writing { penиətra ¯ иshən depth } with ink. { pen } penetration number [ ENG ] The consistency of pencil [ ENG ] An implement for writing or mak- greases, waxes, petrolatum, and asphalt or other ing marks with a solid substance; the three basic bituminous materials expressed as the distance kinds are graphite, carbon, and colored. that a standard needle penetrates the sample { penиsəl} under specified American Society for Testing and pencil cave [ ENG ] A driller’s term for hard, Materials test conditions. { penиətra ¯ иshən closely jointed shale that caves into a well in nəmиbər} pencil-shaped fragments. { penиsəl ka ¯ v} penetration rate [ MECH ENG ] The actual rate of pendant atomizer See hanging-drop atomizer. penetration of drilling tools. { penиətra ¯ иshən { penиdənt adиəmizиər} ra ¯ t} pendant post [ BUILD ] A post on a solid support penetration speed [ MECH ENG ] The speed at and set against a wall to support a collar beam which a drill can cut through rock or other mate- or other part of a roof. { penиdənt po ¯ st } rial. { penиətra ¯ иshən spe ¯ d} pendulous gyroscope [ MECH ] A gyroscope penetration test [ ENG ] A test to determine the whose axis of rotation is constrained by a suit- relative values of density of noncohesive sand able weight to remain horizontal; it is the basis or silt at the bottom of boreholes. { penиətra ¯ и of one type of gyrocompass. { penиjəиləs jı ¯ и shən test } rəsko ¯ p} penetrometer [ ENG ] 1. An instrument that pendulum anemometer [ ENG ] A pressure-plate measures the penetrating power of a beam of x- anemometer consisting of a plate which is free rays or other penetrating radiation. 2. An in- to swing about a horizontal axis in its own plane strument used to determine the consistency of above its center of gravity; the angular deflection a material by measurement of the depth to which of the plate is a function of the wind speed; this a standard needle penetrates into it under stand- instrument is not used for station measurements ard conditions. { penиətra ¨ mиədиər} because of the false reading which results when Penex process [ CHEM ENG ] A continuous, the frequency of the wind gusts and the natural nonregenerative petroleum-refinery process for frequency of the swinging plate coincide. isomerization of C 5 or C 6 fractions in the pres- { penиjəиləm anиəma ¨ mиədиər} ence of hydrogen and a platinum catalyst. pendulum level [ ENG ] A leveling instrument in { peneks pra ¨ иsəs} which the line of sight is automatically kept hori- Penning trap [ ENG ] A device for trapping elec- zontal by a built-in pendulum device (such as a trons and isolating single electrons, consisting horizontal arm and a plumb line at right angles of a large, homogeneous magnetic field plus a superimposed weak parabolic electric potentialto the arm). { penиjəиləm levиəl} 395 Penning-trap mass spectrometer created by a positive charge ϩQ on a ring elec- the suitability of a soil for the installation of a trode and two negative charges ϪQ/2 each on domestic sewage-disposal system, in which a two cap electrodes. { penиiŋtrap } hole is dug and filled with water and the rate Penning-trap mass spectrometer [ ENG ] A de- of water-level decline is measured. { pərиkəla ¯ и vice for making highly accurate comparisons of shən test } the masses of charged atoms and molecules by percussion bit [ MECH ENG ] A rock-drilling tool comparing the cyclotron frequencies of single with chisellike cutting edges, which when driven ions in a Penning trap. { ¦penиiŋtrap mas spek by impacts against a rock surface drills a hole tra ¨ mиədиər} by a chipping action. { pərkəshиən bit } Pennsylvania truss [ CIV ENG ] A truss character- percussion drill [ MECH ENG ] A drilling ma- ized by subdivided panels, curved top chords on chine usually using compressed air to drive a through trusses, and curved bottom chords on piston that delivers a series of impacts to the deck spans; used on long bridge spans. { ¦penи shank end of a drill rod or steel and attached səl¦va ¯ иnyətrəs} bit. { pərkəshиən dril } pennyweight [ MECH ] A unit of mass equal to percussion drilling [ MECH ENG ] A drilling 1/20 troy ounce or to 1.55517384 grams; the term method in which hammer blows are transmitted is employed in the United States and in England by the drill rods to the drill bit. { pərkəshиən for the valuation of silver, gold, and jewels. Ab- drilиiŋ } breviated dwt; pwt. { penиe ¯ wa ¯ t} perfect dielectric See ideal dielectric. { pərиfikt pen recorder [ ENG ] A device in which the vary- dı ¯ иəlekиtrik } ing inputs (electrical, pneumatic, mechanical) perfect gas See ideal gas. { pərиfikt gas } are marked by a signal-controlled pen onto a perfect lubrication [ ENG ] A complete, unbro- continuous recorder chart (circular or roll chart). ken film of liquid formed over each of two metal { pen riko ˙ rdиər} surfaces moving relatively to one another with Pensky-Martens closed tester [ CHEM ENG ] De- no contact. { pərиfikt lu ¨ иbrəka ¯ иshən} vice to determine the American Society for Test- perforated-pipe distributor [ CHEM ENG ] Liquid ing and Materials flash point of fuel oils and distribution device consisting of a length of pip- cutback asphalts and other viscous materials ing or tubing with holes at spaced intervals along and suspensions of solids. { penиske ¯ ma ¨ rtиənz the length; used in spray columns, liquid-vapor klo ¯ sd tesиtər} penstock [ CIV ENG ] A valve or sluice gate for contactors, and spray driers. Also known as a regulating water or sewage flow. [ ENG ] A sparger. { pərиfəra ¯ dиəd ¦pı ¯ pdistribиyədиər} closed water conduit controlled by valves and perforated plate [ CHEM ENG ] Flat plate with se- located between the intake and the turbine in a ries of holes used to control fluid distribution, hydroelectric plant. { pensta ¨ k} as in a perforated-plate (distillation) column. pentane lamp [ ENG ] A pentane-burning lamp { pərиfəra ¯ dиəd pla ¯ t} formerly used as a standard for photometry. perforated-plate column [ CHEM ENG ] Distilla- { penta ¯ n lamp } tion column in which vapor-liquid contact is pro- penthouse [ BUILD ] 1. An enclosed space built vided by perforated plates instead of bubble-cap on a flat roof to cover a stairway, elevator, or trays. { pərиfəra ¯ dиəd ¦pla ¯ t ka ¨ lиəm} other equipment. 2. A dwelling built on top of perforated-plate distributor [ CHEM ENG ] 1. A the main roof. 3. A sloping shed or roof perforated plate or screen used to even out liq- attached to a wall or building. { penthau ˙ s} uid-flow fluctuations through flow channels. percentage log [ ENG ] A sample log in which 2. A perforated plate as used in a distillation the percentage of each type of rock (except obvi- column or liquid-liquid extraction column. ous cavings) present in each sample of cuttings { pərиfəra ¯ dиəd ¦pla ¯ tdistribиyədиər} is estimated and plotted. { pərsenиtij la ¨ g} perforated-plate extractor [ CHEM ENG ] A liq- percent compaction [ ENG ] The ratio, expressed uid-liquid extraction vessel in which perforated as a percentage, of dry unit weight of a soil to plates are used to bring about contact between maximum unit weight obtained in a laboratory the two or more liquid phases. { pərиfəra ¯ dиəd compaction test. { pərsent kəmpakиshən} ¦pla ¯ tikstrakиtər} percent defective [ IND ENG ] The ratio of defec- performance bond [ ENG ] A bond that guaran- tive pieces per lot or sample, expressed as a tees performance of a contract. { pərfo ˙ rи percentage. { pərsent difekиdiv } məns ba ¨ nd } perch [ MECH ] Also known as pole; rod. 1. A performance characteristic [ ENG ] A character- unit of length, equal to 5.5 yards, or 16.5 feet, istic of a piece of equipment, determined during or 5.0292 meters. 2. A unit of area, equal to its test or during its operation. { pərfo ˙ rиməns 30.25 square yards, or 272.25 square feet, or karиikиtərisиtik } 25.29285264 square meters. { pərch } performance chart [ ENG ] A graph used in eval- percolation filtration [ CHEM ENG ] A continuous uating the performance of any device, for exam- petroleum-refinery process in which lubricating ple, the performance of an electrical or electronic oils and waxes are percolated through a clay device, such as a graph of anode voltage versus bed to improve color, odor, and stability. { pərи anode current for a magnetron. { pərfo ˙ rи kəla ¯ иshən filtra ¯ иshən} percolation test [ CIV ENG ] A test to determine məns cha ¨ rt } 396 permeameter performance curves [ ENG ] Graphical represen- subsoil and rocks in which the contained water is permanently frozen. { pərиməfro ˙ st drilиiŋ }tations showing the abilities of rotating equip- ment at various operating conditions; for exam- permanent axis [ MECH ] The axis of the greatest moment of inertia of a rigid body, about whichple, the performance curve for a compressor would include rotor speed for various intake and it can rotate in equilibrium. { pərиməиnənt akиsəs}outlet pressures versus gas flow rate adjusted for temperature, density, viscosity, head, and other permanent benchmark [ ENG ] A readily identifi- able, relatively permanent, recoverable bench-factors. { pərfo ˙ rиməns kərvz } performance data [ ENG ] Data on the manner mark that is intended to maintain its elevation without change over a long period of time within which a given substance or piece of equipment performs during actual use. { pərfo ˙ rиməns reference to an adopted datum, and is located where disturbing influences are believed to bedadиə } performance evaluation [ IND ENG ] The analy- negligible. { pərиməиnənt benchma ¨ rk } permanent gas [ THERMO ] A gas at a pressuresis in terms of initial objectives and estimates, and usually made on site, of accomplishments and temperature far from its liquid state. { pərи məиnənt gas }using an automatic data-processing system, to provide information on operating experience permanent-magnet dynamic loudspeaker See per- manent-magnet loudspeaker. { pərиməиnəntand to identify corrective actions required, if any. {pərfo ˙ rиməns ivalиyəwa ¯ иshən} ¦magиnətdı ¯ ¦namиik lau ˙ dspe ¯ kиər} permanent-magnet loudspeaker [ ENG ACOUS ] performance index [ IND ENG ] The ratio of standard hours to the hours of work actually A moving-conductor loudspeaker in which the steady magnetic field is produced by a perma-used; a ratio exceeding 1.00 (or 100) indicates standard output is being exceeded. { pərfo ˙ rи nent magnet. Also known as permanent-mag- net dynamic loudspeaker. { pərиməиnənt ¦magиməns indeks } performance measurement baseline [ IND ENG ] nət lau ˙ dspe ¯ kиər} permanent-magnet moving-coil instrument A time-phased budget plan developed for use in measuring contract performance; includes the [ ENG ] An ammeter or other electrical instru- ment in which a small coil of wire, supported onbudgets assigned to scheduled work elements and the related indirect budgets. { pər¦fo ˙ rmи jeweled bearings between the poles of a perma- nent magnet, rotates when current is carried toəns ¦mezhиərиmənt ba ¯ slı ¯ n} performance number [ ENG ] One of a series of it through spiral springs which also exert a re- storing torque on the coil; the position of thenumbers (constituting the PN, or performance- number, scale) used to convert fuel antiknock coil is indicated by an attached pointer. { pərи məиnənt ¦magиnət ¦mu ¨ vиiŋ ¦ko ¯ il inиstrəиmənt }values in terms of a reference fuel into an index which is an indication of relative engine perfor- permanent-magnet moving-iron instrument [ ENG ] A meter that depends for its operationmance; used mostly to rate aviation gasolines with octane values greater than 100. { pərfo ˙ rи on a movable iron vane that aligns itself in the resultant magnetic field of a permanent magnetməns nəmиbər} performance rating See effort rating. { pərfo ˙ rи and adjacent current-carrying coil. { pərиməи nənt ¦magиnət ¦mu ¨ vиiŋ ¦ı ¯ иərn inиstrəиmənt }məns ra ¯ dиiŋ } performance sampling [ IND ENG ] A technique permanent set [ MECH ] Permanent plastic de- formation of a structure or a test piece afterin work measurement used to determine the lev- eling factor to be applied to an operator or a removal of the applied load. Also known as set. { pərиməиnənt set }group of operators by short, randomly spaced observations of the performance index. permanent stop [ IND ENG ] In a flexible manu- facturing system a type of controlled stop where{pərfo ˙ rиməns samиpliŋ } peridynamic loudspeaker [ ENG ACOUS ] Box- an automated guided vehicle will always halt, regardless of programming. { pərиməиnənttype loudspeaker baffle designed to give good bass response by minimizing acoustic standing. sta ¨ p} permeability number [ ENG ] A numbered value{ ¦perиəиdənamиik lau ˙ dspe ¯ kиər} periodic kiln [ ENG ] A kiln in which the cycle of assigned to molding materials indicating the rel- ative ease of passage of gases through them.setting ware in the kiln, heating up, ‘‘soaking’’ or holding at peak temperature for some time, { pərиme ¯ иəbilиədиe ¯ nəmиbər} permeameter [ ENG ] 1. A laboratory device forcooling, and removing or ‘‘drawing’’ the ware is repeated for each batch. { ¦pirиe ¯ ¦a ¨ dиik kil } measurement of permeability of materials, for example, soil or rocks; consists of a powder bed periodic motion [ MECH ] Any motion that re- peats itself identically at regular intervals. of known dimension and degree of packing through which the particles are forced; pressure{ ¦pirиe ¯ ¦a ¨ dиik mo ¯ иshən} peripheral speed See cutting speed. { pərifиəи drop and rate of flow are related to particle size, and pressure drop is related to surface area.rəl ¦spe ¯ d} peristaltic pump [ MECH ENG ] A device for mov- 2. A device for measuring the coefficient of per- meability by measuring the flow of fluid throughing fluids by the action of multiple, equally spaced rollers, which rotate and compress a flexi- a sample across which there is a pressure drop produced by gravity. 3. An instrument for mea-ble tube. { perиəstalиtik pəmp } permafrost drilling [ ENG ] Boreholes drilled in suring the magnetic flux or flux density produced 397 [...]... pint (liq pt) 2 A unit of volume used in the United States for measurement of solid substances, equal to 1/64 U.S bushel, or 1 07, 521 / 320 0 cubic inches, or approximately 5.50610 ϫ 10Ϫ4 cubic meter Also known as dry pint (dry pt) 3 A unit of volume, used in the United Kingdom for measurement of liquid and solid substances, although usually the former, equal to 1/8 imperial gallon, or 5.6 826 125 ϫ 10Ϫ4 cubic... plan lamи ¯ əиnə } plane of departure [MECH] Vertical plane containing the path of a projectile as it leaves the muzzle of the gun { plan əv di parиchər } ¨ ¯ plane of fire [MECH] Vertical plane containing the gun and the target, or containing a line of site { plan əv fır } ¯ ¯ plane of maximum shear stress [MECH] Either of two planes that lie on opposite sides of and at angels of 45Њ to the maximum principal... an orifice of 0.030 inch (0 .76 millimeter) or less in diameter through which molten resin enters a mold cavity { pin point gat } ˙ ¯ pin rod [DES ENG] A rod designed to connect two parts so they act as one { pin rad } ¨ pint [MECH] Abbreviated pt 1 A unit of volume, used in the United States for measurement of liquid substances, equal to 1/8 U.S gallon, or 23 1/8 cubic inches, or 4 .73 176 473 ϫ 10Ϫ4 cubic... determine the flow properties of a thermoplastic resin by forcing molten resin through a specified die opening or orifice at a given pressure and temperature { pla stamиədиər } ¨ plate [BUILD] 1 A shoe or base member, such as of a partition or other kind of frame 2 The top horizontal member of a row of studs used in a frame wall [DES ENG] A rolled, flat piece of metal of some arbitrary minimum thickness... ENG] A cone representing the pitch surface of a bevel gear { pich kon } ¯ pitch cylinder [DES ENG] A cylinder representing the pitch surface of a spur gear { pich silи ənиdər } pitch diameter [DES ENG] The diameter of the pitch circle of a gear { pich dı amиədиər } ¯ pitched roof [BUILD] 1 A roof that has one or more surfaces with a slope greater than 10Њ 2 A roof that has two slopes meeting at a central... bearing piles with a pile cap forming that part of a trestle which carries the adjacent ends of timber stringers or concrete slabs { pıl bent } ¯ pile cap [CIV ENG] A mass of reinforced concrete cast around the head of a group of piles to ensure that they act as a unit to support the imposed load { pıl kap } ¯ pile dike [CIV ENG] A dike consisting of a group of piles braced and lashed together along... main face of the bit { pıиlət bit } ¯ pilot channel [CIV ENG] One of a series of cutoffs for converting a meandering stream into a straight channel of greater slope { pıиlət ¯ chanиəl } pilot drill [MECH ENG] A small drill to start a hole to ensure that a larger drill will run true to center { pıиlət dril } ¯ piloted ignition [ENG] The accidental initiation of combustion by means of contact of gaseous... piston, and operates at 3000 revolutions per minute, with hot-chamber temperature of 120 0ЊF (650ЊC), maximum pressure of 50 atmospheres (5. 07 megapascals), and mean effective pressure of 14 atmospheres (1. 42 megapascals) { filи əps hat ¦er enиjən } ¨ Phillips screw [DES ENG] A screw having in its head a recess in the shape of a cross; it is inserted or removed with a Phillips screwdriver that automatically... picoamperes { peиko am edиər } ¯ ¯ ¯ picosecond [MECH] A unit of time equal to 10Ϫ 12 second, or one-millionth of a microsecond Abbreviated ps; psec { peиko sekиənd } ¯ ¯ picowatt [MECH] A unit of power equal to 10Ϫ 12 watt, or one-millionth of a microwatt Abbreviated pW { peиkə wat } ¨ ¯ picture element [ELECTR] 1 That portion, in facsimile, of the subject copy which is seen by the scanner at any instant;... about an axis parallel to the lateral axis of the vehicle 2 The rising and falling motion of the bow of a ship or the tail of an airplane as the craft oscillates about a transverse axis { pich } pitch acceleration [MECH] The angular acceleration of an aircraft or missile about its lateral, or Y, axis { pich ik selиə raиshən } ¯ pitch attitude [MECH] The attitude of an aircraft, rocket, or other flying . equal to its test or during its operation. { pərfo ˙ rиməns 30 .25 square yards, or 27 2 .25 square feet, or karиikиtərisиtik } 25 .29 28 526 4 square meters. { pərch } performance chart [ ENG ] A graph. 0.00880 976 7541 72 cubic meter. 2. A unit of vol- ume used in the United Kingdom for measure-involved in specifying the trajectory followed by a robot. { path ka ¨ mиpyəta ¯ иshən } ment of solid. characteristic [ ENG ] A character- unit of length, equal to 5.5 yards, or 16.5 feet, istic of a piece of equipment, determined during or 5. 029 2 meters. 2. A unit of area, equal to its test or during

Ngày đăng: 21/07/2014, 15:20

TỪ KHÓA LIÊN QUAN