Dictionary of Engineering

path computationan invention for a limited period of time. Also of solid substances, equal to 8 dry quarts, orknown as letters patent. { patənt }1/4 bushel, or 537.605 cubic inches, orpath computation [CONT SYS] The calculations 0.00880976754172 cubic meter. 2. A unit of volumeinvolved in specifying the trajectory followed byused in the United Kingdom for measureinvolveda robot. { path kämpyətāshən } ment of solid and liquid substances, althoughpattern [ENG] A form designed and used as a usually the former, equal to 2 gallons, ormodel for making things. { padərn } 0.00909218 cubic meter. { pek }pattern shooting [ENG] In seismic prospecting, Peclet number [CHEM ENG] Dimensionlessfiring of explosive charges arranged in geometric group used to determine the chemical reactionpattern. { padərn shüdiŋ }similitude for the scale-up from pilot-plant datapavement [BUILD] A hard floor of concrete, to commercial-sized units; incorporates heat capacity,density, fluid velocity, and other pertinentbrick, tiles, or other material. [CIV ENG] Apaved surface. { pāvmənt } physical parameters. { pəklā nəmbər }pavement light [CIV ENG] A window built into pedal [DES ENG] A lever operated by foot.the surface of a pavement to admit daylight to { pedəl }a space below ground level. { pāvmənt līt } pedestal [CIV ENG] 1. The support for a column.paver [MECH ENG] Any of several machines 2. A metal support carrying one end of a bridgewhich, moving along the road, carry and lay pavingtruss or girder and transmitting any load to thematerial. { pāvər } top of a pier or abutment. [ELECTR] See blank-pawl [MECH ENG] The driving link or holding ing level. [ENG] A supporting part or the baselink of a ratchet mechanism, permits motion in of an upright structure, such as a radar antenna.one direction only. { pȯl }{ pedəstəl }payback period [IND ENG] The amount of time pedestal design [MECH ENG] A robot designrequired for achieving an amount in profits to centered on the vertical axis of a central pedestal,offset the cost of a capital expenditure, such as in which the motion of any workpiece is confinedthe cost of investment in modifications in an to a spherical working envelope. { pedəstəlindustrial facility for the purpose of conserving dizīn }energy. { pābak pirēəd }pedestal flooring See raised flooring. { pedəpayout time [IND ENG] A measurement of prof- stəl flȯriŋ }itability or liquidity of an investment, being the pedestal pile [CIV ENG] A concrete pile with atime required to recover the original investment bulbous enlargement at the bottom. { pedin depreciable facilities from profit and depreciation;əstəl pīl }usually, but not always, calculated after in- pedometer [ENG] 1. An instrument for measur-come taxes. { pāau˙ t tīm }ing and weighing a newborn child. 2. An instru-p-channel metal-oxide semiconductor See PMOS. ment that registers the number of footsteps and{ ¦pē chanəl medəl ¦äksīd semikəndəktər } distance covered in walking. { pədämədər }p chart [IND ENG] A chart of the fraction defec- peel-back [ENG] The separation of two bondedtive, either observed in the sample or in some materials, one or both of which are flexible, byproduction period. { pē chärt } stripping or pulling the flexible material frompdl-ft See foot-poundal.the mating surface at a 90 or 180 angle to thePDM See precedence diagram method. plane in which it is adhered. { pēl bak }PDR See precision depth recorder.peel-off time [ENG] In seismic prospecting, thepeak load [ELEC] The maximum instantaneous time correction applied to observed data to adjustload or the maximum average load over a designatedthem to a depressed reference datum.interval of time. Also known as peak { pēl ȯf tīm }power. [ENG] The maximum quantity of a peel test [ENG] A test to ascertain the adhesivespecified material to be carried by a conveyor strength of bonded strips of metals by peelingper minute in a specified period of time. or pulling the metal strips back and recording{ pēk lōd } the adherence values. { pēl test }peak power See peak load. { pēk pau˙ ər } peen [DES ENG] The end of a hammer head withPeaucellier linkage [MECH ENG] A mechanical a hemispherical, wedge, or other shape; used tolinkage to convert circular motion exactly into bend, indent, or cut. { pēn }straight-line motion. { pȯselyā liŋkij } peepdoor [MECH ENG] A small door in a furnacepebble heater [CHEM ENG] Gas-heating devicewith a glass opening through which compebble(for air, hydrogen, methane, and steam) in which bustion may be observed. { pēpdȯr }heat is transferred to the gas via a countercurrent peg [ENG] 1. A small pointed or tapered piece,movement of preheated pebbles. { pebəl often cylindrical, used to pin down or fastenhēdər }parts. 2. A projection used to hang or supportpebble mill [MECH ENG] A solids size-reduction objects. { peg }device with a cylindrical or conical shell rotating peg count meter [ENG] A meter or register thaton a horizontal axis, and with a grinding medium counts the number of trunks tested, the numbersuch as balls of flint, steel, or porcelain. { peb of circuits passed busy, the number of test fail-əl mil }ures, or the number of repeat tests completed.peck [MECH] Abbreviated pk. 1. A unit of volume{ peg kau˙ nt mēdər }used in the United States for measurement PEL See permissible exposure limit. { pel}394