Baixe Dictionary of Engineering e outras Notas de estudo em PDF para Engenharia Mecânica, somente na Docsity! c - EDITION DICTIONARY OF ENGINEERING | : a 1 MORE THAN 18,000 ESSENTIAL TERMS COVERS EVERY DISCIPLINE OF ENGINEERING PROVIDES SYNONYMS, ACRONYMS, AND ABBREVIATIONS McGraw-Hill Dictionary of Engineering Second Edition McGraw-Hill New York Chicago San Francisco Lisbon London Madrid Mexico City Milan New Delhi San Juan Seoul Singapore Sydney Toronto This page intentionally left blank. Preface The McGraw-Hill Dictionary of Engineering provides a compendium of more than 18,000 terms that are central to the various branches of engineering and related fields of science. The coverage in this Second Edition is focused on building construction, chemical engineering, civil engineering, control systems, design engineering, electricity and electronics, engineering acoustics, industrial engi- neering, mechanics and mechanical engineering, systems engineering, and thermodynamics. Many new entries have been added since the previous edition with others revised as necessary. Many of the terms used in engineering are often found in specialized dictionaries and glossaries; this Dictionary, however, aims to provide the user with the convenience of a single, comprehensive reference. All of the definitions are drawn from the McGraw-Hill Dictionary of Scientific and Technical Terms, Sixth Edition (2003). Each definition is classified according to the field with which it is primarily associated; if it is used in more than one area, it is idenfified by the general label [ENGINEERING]. The pronunciation of each term is provided along with synonyms, acronyms, and abbreviations where appropriate. A guide to the use of the Dictionary appears on pages vii and viii, explaining the alphabetical organization of terms, the format of the book, cross referencing, and how synonyms, variant spellings, abbreviations, and similar information are handled. The Pronunciation Key is given on page xi. The Appendix provides conversion tables for commonly used scientific units as well as listings of usefulmathematical, engineering, and scientific data. It is the editors’ hope that the Second Edition of the McGraw-Hill Dictionary of Engineering will serve the needs of scientists, engineers, students, teachers, librarians, and writers for high-quality information, and that it will contribute to scientific literacy and communication. Mark D. Licker Publisher v Copyright 2003 by The McGraw-Hill Companies, Inc. Click Here for Terms of Use. Staff Mark D. Licker, Publisher—Science Elizabeth Geller, Managing Editor Jonathan Weil, Senior Staff Editor David Blumel, Staff Editor Alyssa Rappaport, Staff Editor Charles Wagner, Digital Content Manager Renee Taylor, Editorial Assistant Roger Kasunic, Vice President—Editing, Design, and Production Joe Faulk, Editing Manager Frank Kotowski, Jr., Senior Editing Supervisor Ron Lane, Art Director Thomas G. Kowalczyk, Production Manager Pamela A. Pelton, Senior Production Supervisor Henry F. Beechhold, Pronunciation Editor Professor Emeritus of English Former Chairman, Linguistics Program The College of New Jersey Trenton, New Jersey vi Copyright 2003 by The McGraw-Hill Companies, Inc. Click Here for Terms of Use. Fields and Their Scope building construction—The technology of assembling materials into a struc- ture, especially one designated for occupancy. chemical engineering—A branch of engineering which involves the design and operation of chemical plants. civil engineering—The planning, design, construction, and maintenance of fixed structures and ground facilities for industry, for transportation, for use and control of water, for occupancy, and for harbor facilities. control systems—The study of those systems in which one or more outputs are forced to change in a desired manner as time progresses. design engineering—The branch of engineering concerned with the design of a product or facility according to generally accepted uniform standards and procedures, such as the specification of a linear dimension, or a manufacturing practice, such as the consistent use of a particular size of screw to fasten covers. electricity—The science of physical phenomena involving electric charges and their effects when at rest and when in motion. electronics—The technological area involving the manipulation of voltages and electric currents through the use of various devices for the purpose of performing some useful action with the currents and voltages; this field is generally divided into analog electronics, in which the signals to be manipu- lated take the form of continuous currents or voltages, and digital electronics, in which signals are represented by a finite set of states. engineering—The science by which the properties of matter and the sources of power in nature are made useful to humans in structures, machines, and products. engineering acoustics—The field of acoustics that deals with the production, detection, and control of sound by electrical devices, including the study, design, and construction of such things as microphones, loudspeakers, sound recorders and reproducers, and public address sytems. industrial engineering—A branch of engineering dealing with the design, development, and implementation of integrated systems of humans,machines, and information resources to provide products and services. ix Copyright 2003 by The McGraw-Hill Companies, Inc. Click Here for Terms of Use. mechanical engineering—The branch of engineering concerned with energy conversion, mechanics, and mechanisms and devices for diverse applications, ranging from automotive parts through nanomachines. mechanics—The branch of physics which seeks to formulate general rules for predicting the behavior of a physical system under the influence of any type of interaction with its environment. systems engineering—The branch of engineering dealing with the design of a complex interconnection ofmany elements (a system) tomaximize an agreed- upon measure of system performance. thermodynamics—The branch of physics which seeks to derive, from a few basic postulates, relations between properties of substances, especially those which are affected by changes in temperature, and a description of the conver- sion of energy from one form to another. x Pronunciation Key Vowels Consonants a as in bat, that b as in bib, dribble ā as in bait, crate ch as in charge, stretch ä as in bother, father d as in dog, bad e as in bet, net f as in fix, safe ē as in beet, treat g as in good, signal i as in bit, skit h as in hand, behind ı̄ as in bite, light j as in joint, digit ō as in boat, note k as in cast, brick ȯ as in bought, taut k as in Bach (used rarely) u̇ as in book, pull l as in loud, bell ü as in boot, pool m as in mild, summer ə as in but, sofa n as in new, dent au̇ as in crowd, power n indicates nasalization of preced- ȯi as in boil, spoil ing vowel yə as in formula, spectacular ŋ as in ring, single yü as in fuel, mule p as in pier, slip r as in red, scar Semivowels/Semiconsonants s as in sign, post w as in wind, twin sh as in sugar, shoe y as in yet, onion t as in timid, cat th as in thin, breath Stress (Accent) th as in then, breathe precedes syllable with primary v as in veil, weave stress z as in zoo, cruise zh as in beige, treasure precedes syllable with secondary stress Syllabication Indicates syllable boundary¦ precedes syllable with variable when following syllable is or indeterminate primary/ unstressed secondary stress xi Copyright 2003 by The McGraw-Hill Companies, Inc. Click Here for Terms of Use. acceleration of free fall absorption cycle [MECH ENG] In refrigeration, the form of falling droplets. Also known as ab- the process whereby a circulating refrigerant, for sorption column. { əbsȯrpshən tau̇ər } example, ammonia, is evaporated by heat from absorption trench [CIV ENG] A trench con- an aqueous solution at elevated pressure and taining coarse aggregate about a distribution tile subsequently reabsorbed at low pressure, dis- pipe through which septic-tank effluent may placing the need for a compressor. { əbsȯrp move beneath earth. { əbsȯrpshən trench } shən sı̄kəl } absorptivity [THERMO] The ratio of the radia- absorption dynamometer [ENG] A device for tion absorbed by a surface to the total radiation measuring mechanical forces or power in which incident on the surface. { əbsȯrptivədē } the mechanical energy input is absorbed by fric- Abt track [CIV ENG] One of the cogged rails tion or electrical resistance. { əbsȯrpshən used for railroad tracking in mountains and so dı̄nəmämədər } arranged that the cogs are not opposite one an- absorption-emission pyrometer [ENG] A ther- other on any pair of rails. { apt trak } mometer for determining gas temperature from abutment [CIV ENG] A surface or mass provided measurement of the radiation emitted by a cali- to withstand thrust; for example, end supports brated reference source before and after this ra- of an arch or a bridge. { əbətmənt } diation has passed through and been partially abutting joint [DES ENG] A joint which connects absorbed by the gas. { əbsȯrpshən əmishən two pieces of wood in such a way that the direc- pı̄rämədər } tion of the grain in one piece is angled (usually absorption field [CIV ENG] Trenches containing at 90) with respect to the grain in the other. coarse aggregate about distribution pipes per- { əbətiŋ jȯint } mitting septic-tank effluent to seep into sur- abutting tenons [DES ENG] Two tenons inserted rounding soil. Also known as disposal field. into a common mortise from opposite sides so { əbsȯrpshən fēld } that they contact. { əbətiŋ tenənz } absorption hygrometer Also known as chemical ac See alternating current. hygrometer. [ENG] An instrument with which accelerated aging [ENG] Hastening the deteri- the water vapor content of the atmosphere is oration of a product by a laboratory procedure measured by means of the absorption of vapor in order to determine long-range storage andby a hygroscopic chemical. { əbsȯrpshən use characteristics. { akselərādəd ājiŋ }hı̄grämədər } accelerated life test [ENG] Operation of a de-absorption loss [CIV ENG] The quantity of water vice, circuit, or system above maximum ratingsthat is lost during the initial filling of a reservoir to produce premature failure; used to estimatebecause of absorption by soil and rocks. normal operating life. { akselərādəd lı̄f{ əbsȯrpshən lȯs } test }absorption meter [ENG] An instrument de- acceleratedweathering [ENG] A laboratory testsigned to measure the amount of light transmit- used to determine, in a short period of time,ted through a transparent substance, using a the resistance of a paint film or other exposedphotocell or other light detector. { əbsȯrp surface to weathering. { akselərādəd wethshən mēdər } əriŋ }absorption number [ENG] A dimensionless accelerating incentive See differential piece-rategroup used in the field of gas absorption in a system. { akselərādiŋ insentiv }wetted-wall column; represents the liquid side accelerating potential [ELECTR] The energy po-mass-transfer coefficient. { əbsȯrpshən tential in electron-beam equipment that impartsnəmbər } additional speed and energy to the electrons.absorption plant [CHEM ENG] A facility to re- { akselərādiŋ pətenshəl }cover the condensable portion of natural or refin- acceleration [MECH] The rate of change ofery gas. { əbsȯrpshən plant } velocity with respect to time. { akselərāabsorption process [CHEM ENG] A method in shən }which light oil is introduced into an absorption acceleration analysis [MECH ENG] A mathe-tower so that it absorbs the gasoline in the rising matical technique, often done graphically, bywet gas; the light oil is then distilled to separate which accelerations of parts of a mechanism arethe gasoline. { əbsȯrpshən präsəs } determined. { akselərāshən ənaləsəs }absorption refrigeration [MECH ENG] Refriger- acceleration-error constant [CONT SYS] The ra-ation in which cooling is effected by the expan- tio of the acceleration of a controlled variablesion of liquid ammonia into gas and absorption of a servomechanism to the actuating error whenof the gas by water; the ammonia is reused after the actuating error is constant. { akselərāthe water evaporates. { əbsȯrpshən rəfrij shən erər känstənt }ərāshən } acceleration measurement [MECH] The tech-absorption system [MECH ENG] A refrigeration nique of determining the magnitude and direc-system in which the refrigerant gas in the evapo- tion of acceleration, including translational andrator is taken up by an absorber and is then, with angular acceleration. { akselərāshən mezhthe application of heat, released in a generator. ərmənt }{ əbsȯrpshən sistəm } acceleration of free fall See acceleration of gravity.absorption tower [ENG] A vertical tube in which a rising gas is partially absorbed by a liquid in { akselərāshən əv frē fȯl } 3 acceleration of gravity acceleration of gravity [MECH] The accelera- acceptable quality level [IND ENG] The maxi- mum percentage of defects that has been deter-tion imparted to bodies by the attractive force mined tolerable as a process average for a sam-of the earth; has an international standard value pling plan during inspection or test of a productof 980.665 cm/s2 but varies with latitude and with respect to economic and functional require-elevation. Also known as acceleration of free ments of the item. Abbreviated AQL. { akfall; apparent gravity. { akselərāshən əv ¦septəbəl kwälədē levəl }gravədē } acceptable reliability level [IND ENG] The re-acceleration signature [IND ENG] A printed re- quired level of reliability for a part, system,cord that shows the pattern of acceleration and device, and so forth; may be expressed in a vari-deceleration of an anatomical reference point ety of terms, for example, number of failures in the performance of a task. { akselərāshən allowable in 1000 hours of operating life. Ab-signəchər } breviated ARL. { ak¦septəbəl rəlı̄əbilədē acceleration tolerance [ENG] The degree to levəl } which personnel or equipment withstands accel- acceptance criteria [IND ENG] Standards of eration. { akselərāshən tälərəns } judging the acceptability of manufactured items. acceleration voltage [ELECTR] The voltage be- { akseptəns krı̄tērēə } tween a cathode and accelerating electrode of acceptance number [IND ENG] The maximum an electron tube. { akselərāshən vōltəj } allowable number of defective pieces in a sample accelerator [MECH ENG] A device for varying of specified size. { akseptəns nəmbər } acceptance sampling [IND ENG] Taking a sam-the speed of an automotive vehicle by varying ple from a batch of material to inspect for de-the supply of fuel. { akselərādər } termining whether the entire lot will be acceptedaccelerator jet [MECH ENG] The jet through or rejected. { akseptəns sampliŋ }which the fuel is injected into the incoming air acceptance test [IND ENG] A test used to deter-in the carburetor of an automotive vehicle with mine conformance of a product to design specifi-rapid demand for increased power output. { ak cations, as a basis for its acceptance. { aksepselərādər jet } təns test }accelerator linkage [MECH ENG] The linkage acceptor [CHEM ENG] A calcined carbonateconnecting the accelerator pedal of an automo- used to absorb the carbon dioxide evolved dur-tive vehicle to the carburetor throttle valve or ing a coal gasification process. { akseptər }fuel injection control. { akselərādər liŋkij } access [CIV ENG] Freedom, ability, or the legalaccelerator pedal [MECH ENG] A pedal that op- right to pass without obstruction from a givenerates the carburetor throttle valve or fuel injec- point on earth to some other objective, such as tion control of an automotive vehicle. { aksel the sea or a public highway. { akses }ərādər pedəl } access door [BUILD] A provision for access to accelerator pump [MECH ENG] A small cylinder concealed plumbing or other equipment without and piston controlled by the throttle of an auto- disturbing the wall or fixtures. { akses dȯr } motive vehicle so as to provide an enriched air- access eye [CIV ENG] A threaded plug fitted fuel mixture during acceleration. { akselərād into bends and junctions of drain, waste, or soil ər pəmp } pipes to provide access when a blockage occurs. accelerogram [ENG] A record made by an ac- See cleanout. { akses ı̄ } celerograph. { akselərəgram } access flooring See raised flooring. { akses accelerograph [ENG] An accelerometer having floriŋ } access hole See manhole. { akses hōl }provisions for recording the acceleration of a accessory [MECH ENG] A part, subassembly, orpoint on the earth during an earthquake or for assembly that contributes to the effectivenessrecording any other type of acceleration. { ak of a piece of equipment without changing itsselərəgraf } basic function; may be used for testing, ad-accelerometer [ENG] An instrument which justing, calibrating, recording, or other purposes.measures acceleration or gravitational force ca- { aksesərē }pable of imparting acceleration. { akseləräm access road [CIV ENG] A route, usually paved,ədər } that enables vehicles to reach a designated facil-accelerometry [IND ENG] The quantitative de- ity expeditiously. { akses rōd }termination of acceleration and deceleration in access tunnel [CIV ENG] A tunnel provided for the entire human body or a part of the body in an access road. { akses tənəl } the performance of a task. { akselərämə accident-cause code [IND ENG] Sponsored by drē } the American Standards Association, the code accent lighting [CIV ENG] Directional lighting that classifies accidents under eight defective which highlights an object or attracts attention working conditions and nine improper working to a particular area. { aksent lı̄diŋ } practices. { aksədent ¦kȯz kōd } acceptability [ENG] State or condition of meet- accident frequency rate [IND ENG] The number ing minimum standards for use, as applied to of all disabling injuries per million worker-hours methods, equipment, or consumable products. of exposure. { aksədent frekwənsē rāt } accident severity rate [IND ENG] The number of{ akseptəbilədē } 4 acme screw thread worker-days lost as a result of disabling injuries acfm See actual cubic feet per minute. acid blowcase See blowcase. { asəd blōkās }per thousand worker-hours of exposure. { ak sədent səverədē rāt } acid cleaning [ENG] The use of circulating acid to remove dirt, scale, or other foreign matteraccommodation [CONT SYS] Any alteration in a robot’s motion in response to the robot’s envi- from the interior of a pipe. { asəd klēniŋ } acid conductor [CHEM ENG] A vessel designedronment; it may be active or passive. { əkäm ədāshən } for refortification of hydrolyzed acid by heating and evaporation of water, or sometimes by dis-accordion door [BUILD] A door that folds and unfolds like an accordion when it is opened and tillation of water under partial vacuum. { as əd kəndəktər }closed. { əkȯrdēən dȯr } accordion partition [BUILD] A movable, fabric- acid egg See blowcase. { asəd eg } acid gases [CHEM ENG] The hydrogen sulfidefaced partition which is fitted into an overhead track and folds like an accordion. { əkȯrdēən and carbon dioxide found in natural and refinery gases which, when combined with moisture,pərtishən } accordion roller conveyor [MECH ENG] A con- form corrosive acids; known as sour gases when hydrogen sulfide and mercaptans are present.veyor with a flexible latticed frame which permits variation in length. { əkȯrdēən rōlər kən { asəd gasəz } aciding [ENG] A light etching of a building sur-vāər } accretion [CIV ENG] Artificial buildup of land face of cast stone. { asədiŋ } acid lining [ENG] In steel production, a silica-due to the construction of a groin, breakwater, dam, or beach fill. { əkrēshən } brick lining used in furnaces. { asəd lı̄niŋ } acid number [ENG] A number derived from aaccumulated discrepancy [ENG] The sum of the separate discrepancies which occur in the standard test indicating the acid or base compo- sition of lubricating oils; it in no way indicatesvarious steps of making a survey. { əkyümyə lādəd dəskrepənsē } the corrosive attack of the used oil in service. Also known as corrosion number. { asədaccumulative timing [IND ENG] A time-study method that allows direct reading of the time ¦nəmbər } acid polishing [ENG] The use of acids to polishfor each element of an operation by the use of two stopwatches which operate alternately. a glass surface. { asəd pälishiŋ } acid process [CHEM ENG] In paper manufac-{ əkyümyəlādiv tı̄miŋ } accumulator [CHEM ENG] An auxiliary ram ex- ture, a pulp digestion process that uses an acidic reagent, for example, a bisulfite solution con-truder on blow-molding equipment used to store melted material between deliveries. [ENG] taining free sulfur dioxide. { asəd präsəs } acid recovery plant [CHEM ENG] In some refin-See air vessel. [MECH ENG] 1. A device, such as a bag containing pressurized gas, which acts eries, a facility for separating sludge acid into acid oil, tar, and weak sulfuric acid, with provi-upon hydraulic fluid in a vessel, discharging it rapidly to give high hydraulic power, after which sion for later reconcentration. { asəd rəkəv ərē plant }the fluid is returned to the vessel with the use of low hydraulic power. 2. A device connected acid sludge [CHEM ENG] The residue left after treating petroleum oil with sulfuric acid for theto a steam boiler to enable a uniform boiler output to meet an irregular steam demand. 3. removal of impurities. { asəd sləj } acid soot [ENG] Carbon particles that haveA chamber for storing low-side liquid refrigerant in a refrigeration system. Also known as surge absorbed acid fumes as a by-product of combus- tion; hydrochloric acid absorbed on carbon par-drum; surge header. { əkyümyəlādər } accustomization [ENG] The process of learning ticulates is frequently the cause of metal corro- sion in incineration. { asəd su̇t }the techniques of living with a minimum of dis- comfort in an extreme or new environment. acid treatment [CHEM ENG] A refining process in which unfinished petroleum products, such as{ əkəstəməzāshən } acetate process [CHEM ENG] Acetylation of gasoline, kerosine, and diesel oil, are contacted with sulfuric acid to improve their color, odor,cellulose (wood pulp or cotton linters) with ace- tic acid or acetic anhydride and sulfuric acid cata- and other properties. { asəd trētmənt } acid-water pollution [ENG] Industrial wastewa-lyst to make cellulose acetate resin or fiber. { asətāt präsəs } ters that are acidic; usually appears in effluent from the manufacture of chemicals, batteries,acetone-benzol process [CHEM ENG] A dewax- ing process in petroleum refining, with acetone artificial and natural fiber, fermentation proc- esses (beer), and mining. { asəd wȯdərand benzol used as solvents. { asətōn ben zȯl präsəs } pəlüshən } Ackerman linkage See Ackerman steering gear.acetylene cutting See oxyacetylene cutting. { əsedəlēn kətiŋ } { akərmən liŋkij } acme screw thread [DES ENG] A standardacetylene generator [ENG] A steel cylinder or tank that provides for controlled mixing of cal- thread having a profile angle of 29 and a flat crest; used on power screws in such devices ascium carbide and water to generate acetylene. { əsedəlēn jenərādər } automobile jacks, presses, and lead screws on lathes. Also known as acme thread. { akmēacetylene torch See oxyacetylene torch. { əsed əlēn tȯrch } skrü thred } 5 active area active area [ELECTR] The area of a metallic rec- activity [SYS ENG] The representation in a PERT tifier that acts as the rectifying junction and con- or critical-path-method network of a task that ducts current in the forward direction. { aktiv takes up both time and resources and whose erēə } performance is necessary for the system to move active-cord mechanism [MECH ENG] A slender, from one event to the next. { aktivədē } chainlike grouping of joints and links that makes activity chart [IND ENG] A tabular presentation active and flexible winding motions under the of a series of operations of a process plotted control of actuators attached along its body. against a time scale. { aktivədē chärt } { aktiv ¦kȯrd mekənizəm } activity duration [SYS ENG] In critical-path- active detection system [ENG] A guidance sys- method terminology, the estimated amount of tem which emits energy as a means of detection; time required to complete an activity. { aktiv for example, sonar and radar. { aktiv ditek ədē dərāshən } shən sistəm } activity sampling See work sampling. { aktivədactive earth pressure [CIV ENG] The horizontal ē sampliŋ }pressure that an earth mass exerts on a wall. actual cost [IND ENG] Cost determined by an{ aktiv ərth preshər } allocation of cost factors recorded during pro-active illumination [ENG] Lighting whose direc- duction. { akchəwəl kȯst }tion, intensity, and pattern are controlled by actual cubic feet per minute [CHEM ENG] Acommands or signals. { aktiv əlümənā measure of the volume of gas at operating tem-shən } perature and pressure, as distinct from volumeactive infrared detection system [ENG] An in- of gas at standard temperature and pressure.frared detection system in which a beam of infra- Abbreviated acfm. { akchəwəl kyübik fētred rays is transmitted toward possible targets, pər minət }and rays reflected from a target are detected. actual horsepower See actual power. { akchə{ aktiv infrəred ditekshən sistəm } wəl hȯrspau̇ər }active leaf [BUILD] In a door with two leaves, actual power [MECH ENG] The power deliveredthe leaf which carries the latching or locking at the output shaft of a source of power. Alsomechanism. Also known as active door. { ak known as actual horsepower. { akchəwəltiv lēf } pau̇ər }active material [ELEC] 1. A fluorescent material used in screens for cathode-ray tubes. 2. An actual time [IND ENG] Time taken by a worker energy-storing material, such as lead oxide, used to perform a given task. { akchəwəl tı̄m } in the plates of a storage battery. 3. A material, actuate [MECH ENG] To put into motion or such as the iron of a core or the copper of a mechanical action, as by an actuator. { ak winding, that is involved in energy conversion in chəwāt } a circuit. 4. In a battery, the chemically reactive actuated roller switch [MECH ENG] A centrifu- material in either of the electrodes that partici- gal sequence-control switch that is placed in pates in the charge and discharge reactions. contact with a belt conveyor, immediately pre- [ELECTR] Thematerial of the cathode of an elec- ceding the conveyor which it controls. { ak tron tube that emits electrons when heated. chəwādəd rōlər swich } { aktiv mətirēəl } actuating system [CONT SYS] An electric, hy- active sludge [CIV ENG] A sludge rich in de- draulic, or other system that supplies and trans- structive bacteria used to break down raw sew- mits energy for the operation of other mecha- age. { aktiv sləj } nisms or systems. { akchəwādiŋ sistəm } active solar system [MECH ENG] A solar heat- actuator [CONT SYS] A mechanism to activate ing or cooling system that operates by mechani- process control equipment by use of pneumatic, cal means, such as motors, pumps, or valves. hydraulic, or electronic signals; for example, a { aktiv sōlər sistəm } valve actuator for opening or closing a valve to active sonar [ENG] A system consisting of one control the rate of fluid flow. [ENG ACOUS] An or more transducers to send and receive sound, auxiliary external electrode used to apply a equipment for the generation and detection of known electrostatic force to the diaphragm of athe electrical impulses to and from the trans- microphone for calibration purposes. Alsoducer, and a display or recorder system for the known as electrostatic actuator. [MECH ENG]observation of the received signals. { aktiv A device that produces mechanical force bysōnär } means of pressurized fluid. { akchəwādər }active system [ENG] In radio and radar, a sys- adamantine drill [MECH ENG] A core drill withtem that requires transmitting equipment, such hardened steel shot pellets that revolve underas a beacon or transponder. { aktiv sistəm } the rim of the rotating tube; employed in rotaryactive vibration suppression [MECH ENG] The drilling in very hard ground. { adəmantēnprevention of undesirable vibration by tech- dril }niques involving feedback control of the vibra- Adam’s catalyst [CHEM ENG] Finely dividedtory motion, whereby the forces designed to re- plantinum(IV) oxide, made by fusing hexachloro-duce the vibration depend on the system dis- platinic(IV) acid with NaNO3. { adəmz kadplacements and velocities. { aktiv vı̄brāshən səpreshən } ələst } 8 adjustable base anchor ada mud [ENG] A conditioning material added harmonically related frequencies. { ¦adədiv sinthəsəs }to drilling mud to obtain satisfactory cores and adhesion [ENG] Intimate sticking together ofsamples of formations. { ādə məd } metal surfaces under compressive stresses byadapter [ENG] A device used to make electrical formation of metallic bonds. [MECH] Theor mechanical connections between items not force of static friction between two bodies, ororiginally intended for use together. { ədap the effects of this force. { adhēzhən }tər } adhesional work [THERMO] The work requiredadaptive branch [CONT SYS] A branch instruc- to separate a unit area of a surface at which twotion in the computer program controlling a robot substances are in contact. Also known as workthat may lead the robot to execute a series of of adhesion. { adhēzhənəl wərk }instructions, depending on external conditions. adhesive bond [MECH] The forces such as di-{ ədaptiv branch } pole bonds which attract adhesives and baseadaptive control [CONT SYS] A control method materials to each other. { adhēziv bänd }in which one or more parameters are sensed and adhesive bonding [ENG] The fastening to-used to vary the feedback control signals in order gether of two or more solids by the use of glue,to satisfy the performance criteria. { ədaptiv cement, or other adhesive. { adhēziv bändkəntrōl } iŋ }adaptive-control function [CONT SYS] That adhesive strength [ENG] The strength of an ad-level in the functional decomposition of a large- hesive bond, usually measured as a force re-scale control system which updates parameters quired to separate two objects of standardof the optimizing control function to achieve a bonded area, by either shear or tensile stress.best fit to current plant behavior, and updates { adhēziv streŋkth }parameters of the direct control function to adiabatic [THERMO] Referring to any change inachieve good dynamic response of the closed- which there is no gain or loss of heat. { ¦adē loop system. { ədaptiv kəntrōl fəŋkshən } ə¦badik }adaptive robot [CONT SYS] A robot that can al- adiabatic compression [THERMO] A reduction ter its responses according to changes in the in volume of a substance without heat flow, in environment. { ədaptiv rōbät } or out. { ¦adēə¦badik kəmpreshən } adaptive structure [ENG] A structure whose adiabatic cooling [THERMO] A process in which geometric and inherent structural characteristics the temperature of a system is reduced without can be changed beneficially in response to exter- any heat being exchanged between the system nal stimulation by either remote commands or and its surroundings. { ¦adēə¦badik küliŋ } automatic means. { ədaptiv strəkchər } adiabatic curing [ENG] The curing of concrete adaptive system [SYS ENG] A system that can or mortar under conditions in which there is no change itself in response to changes in its envi- loss or gain of heat. { ¦adēə¦badik kyu̇riŋ } ronment in such a way that its performance im- adiabatic engine [MECH ENG] A heat engine or proves through a continuing interaction with its thermodynamic system in which there is no gain surroundings. { ədaptiv sistəm } or loss of heat. { ¦adēə¦badik enjən } adaptometer [ENG] An instrument that meas- adiabatic envelope [THERMO] A surface en- ures the lowest brightness of an extended area closing a thermodynamic system in an equilib- that can barely be detected by the eye. rium which can be disturbed only by long-range { adaptämədər } forces or by motion of part of the envelope; intu- addendum [DES ENG] The radial distance be- itively, this means that no heat can flow through tween two concentric circles on a gear, one being the surface. { ¦adēə¦badik envəlōp } that whose radius extends to the top of a gear adiabatic expansion [THERMO] Increase in vol- tooth (addendum circle) and the other being that ume without heat flow, in or out. { ¦adēə¦bad which will roll without slipping on a circle on a ik ikspanchən } mating gear (pitch line). { ədendəm } adiabatic extrusion [ENG] Forming plastic ob- addendumcircle [DES ENG] The circle on a gear jects by energy produced by driving the plastic passing through the tops of the teeth. { əden mass through an extruder without heat flow. dəm sərkəl } { ¦adēə¦badik ikstrüzhən } adder [ELECTR] A circuit in which two or more adiabatic process [THERMO] Any thermody- signals are combined to give an output-signal namic procedure which takes place in a system amplitude that is proportional to the sum of the without the exchange of heat with the surround- input-signal amplitudes. Also known as adder ings. { ¦adēə¦badik präsəs } circuit. { adər } adiabatic vaporization [THERMO] Vaporization adding tape [ENG] A surveyor’s tape that is cali- of a liquid with virtually no heat exchange be- brated from 0 to 100 by full feet (ormeters) in one tween it and its surroundings. { ¦adēə¦badik direction, and has 1 additional foot (or meter) vāpərəzāshən } beyond the zero end which is subdivided in adit [CIV ENG] An access tunnel used for excava- tenths or hundredths. { adiŋ tāp } tion of the main tunnel. { adət } additive synthesis [ENG ACOUS] A method of adjustable base anchor [BUILD] An item which synthesizing complex tones by adding together holds a doorframe above a finished floor. { əjəstəbəl ¦bās aŋkər }an appropriate number of simple sine waves at 9 adjustable parallels adjustable parallels [ENG] Wedge-shaped iron block that is not completely cleared. { ədvans bars placed with the thin end of one on the thick signəl } end of the other, so that the top face of the upper advance slope grouting [ENG] A grouting tech- and the bottom face of the lower remain parallel, nique in which the front of the mass of grout is but the distance between the two faces is adjust- forced to move horizontally through preplaced able; the bars can be locked in position by a aggregate. { ədvans slōp grau̇diŋ } screw to prevent shifting. { əjəstəbəl par advance slopemethod [ENG] Amethod of con- əlelz } crete placement in which the face of the fresh adjustable square [ENG] A try square with an concrete, which is not vertical, moves forward arm that is at right angles to the ruler; the posi- as the concrete is placed. { ədvans slōp tion of the arm can be changed to form an L or methəd } a T. Also known as double square. { əjəstə adz [DES ENG] A cutting tool with a thin arched bəl skwer } blade, sharpened on the concave side, at right adjustable wrench [ENG] A wrench with one angles on the handle; used for rough dressing jaw which is fixed and another which is adjust- of timber. { adz } able; the size is adjusted by a knurled screw. adz block [MECH ENG] The part of a machine { əjəstəbəl rench } for wood planing that carries the cutters. adjusting [ENG] In measurement technology, { adz bläk } setting or compensating a measuring instrument aerated flow [ENG] Flowing liquid in which gas or a weight in such a way that the indicated value is dispersed as fine bubbles throughout the liq- deviates as little as possible from the actual uid. { erādəd flō } value. { əjəstiŋ } aeration [ENG] 1. Exposing to the action of air. adjutage [ENG] A tube attached to a container 2. Causing air to bubble through. 3. Introduc- of liquid at an orifice to facilitate or regulate ing air into a solution by spraying, stirring, or outflow. { ajətazh } similar method. 4. Supplying or infusing withadmittance [ELEC] A measure of how readily air, as in sand or soil. { erāshən } alternating current will flow in a circuit; the recip- aeration tank [ENG] A fluid-holding tank with rocal of impedance, it is expressed in siemens. provisions to aerate its contents by bubbling air{ ədmitəns } or another gas through the liquid or by sprayingadobe construction [BUILD] Wall construction the liquid into the air. { erāshən taŋk }with sun-dried blocks of adobe soil. { ədōbē aerator [DES ENG] A tool having a rollerkənstrəkshən } equipped with hollow fins; used to remove coresADP See automatic data processing. of soil from turf. [ENG] 1. One who aerates.ADR studio [ENG ACOUS] A sound-recording 2. Equipment used for aeration. 3. Any devicestudio used in motion-picture and television for supplying air or gas under pressure, as forproduction to allow an actor who did not intelli- fumigating, welding, or ventilating. [MECHgibly record his or her speech during the original ENG] Equipment used to inject compressedfilming or video recording to do so by watching air into sewage in the treatment process.himself or herself on the screen and repeating { erādər }the original speech with lip synchronism; it is aerial cableway See aerial tramway. { erēəlequipped with facilities for recreating the acous- kābəlwā }tical liveness and background sound of the envi- aerial photogrammetry [ENG] Use of aerialronment of the original dialog. Derived from photographs to make accurate measurements inautomatic dialog replacement studio. Also surveying and mapmaking. { erēəl fōtknown as postsynchronizing studio. { ¦ā¦dēär əgramətrē }stüdēō } aerial photographic reconnaissance See aerialadsorption system [MECH ENG] A device that photoreconnaissance. { erēəl fōdə¦grafikdehumidifies air by bringing it into contact with rikänəsəns }a solid adsorbing substance. { adsȯrpshən aerial photography [ENG] Themaking of photo-sistəm } graphs of the ground surface from an aircraft,advance [CIV ENG] In railway engineering, a spacecraft, or rocket. Also known as aeropho-length of track that extends beyond the signal tography. { erēəl fətägrəfē }that controls it. [MECH ENG] To effect the ear- aerial photoreconnaissance [ENG] The ob-lier occurrence of an event, for example, spark taining of information by air photography;advance or injection advance. { ədvans } the three types are strategic, tactical, and sur-advanced programmatic risk analysis [IND vey-cartographic photoreconnaissance. AlsoENG] A method for managing engineering pro- known as aerial photographic reconnaissance.grams with multiple projects and strict resource { erēəl fōdōrikänəsəns }constraints which balances both technical and aerial reconnaissance [ENG] The collection ofmanagement risks. { əd¦vanst prōgrə¦madik information by visual, electronic, or photo-risk ənaləsəs } graphic means while aloft. { erēəl rikänəadvanced sewage treatment See tertiary sewage səns }treatment. { əd¦vanst süij trētmənt } aerial ropeway See aerial tramway. { erēəladvance signal [CIV ENG] A signal in a block system up to which a train may proceed within a rōpwā } 10 air conditioner inflated with gas to provide cushioned protec- air cap [MECH ENG] A device used in thermal tion against the impact of a collision. { er spraying which directs the air pattern for pur- bag } poses of atomization. { er kap } air belt [MECH ENG] The chamber which equal- air casing [ENG] A metal casing surrounding a izes the pressure that is blasted into the cupola pipe or reservoir and having a space between to at the tuyeres. { er belt } prevent heat transmission. { er kāsiŋ } air bind [ENG] The presence of air in a conduit air cell [ELECTR] A cell in which depolarization or pump which impedes passage of the liquid. at the positive electrode is accomplished chemi- { er bı̄nd } cally by reduction of the oxygen in the air. airblasting [ENG] A blasting technique in which [MECH ENG] A small auxiliary combustion air at very high pressure is piped to a steel shell chamber used to promote turbulence and im- in a shot hole and discharged. Also known as prove combustion in certain types of diesel en- air breaking. { erblastiŋ } gines. { er sel } air bleeder [MECHENG] A device, such as a nee- air chamber [MECH ENG] A pressure vessel, dle valve, for removing air from a hydraulic sys- partially filled with air, for converting pulsating tem. { er blēdər } flow to steady flow of water in a pipeline, as with airborne collision warning system [ENG] A sys- a reciprocating pump. { er chāmbər } tem such as a radar set or radio receiver carried air change [ENG] A measure of the movement by an aircraft to warn of the danger of possible of a given volume of air in or out of a building collision. { erbȯrn kəlizhən wȯrniŋ sis or room in a specified time period; usually ex- təm } pressed in cubic feet per minute. { er chānj } airborne detector [ENG] A device, transported air check [ENG ACOUS] A recording made of a by an aircraft, whose function is to locate or live radio broadcast for filing purposes at the identify an air or surface object. { erbȯrn di broadcasting facility. { er chek } tektər } air classifier [MECH ENG] A device to separate airborne electronic survey control [ENG] The particles by size through the action of a stream airborne portion of very accurate positioning sys- of air. Also known as air elutriator. { er klas tems used in controlling surveys from aircraft. əfı̄ər } { erbȯrn ilektränik sərvā kəntrōl } air cleaner [ENG] Any of various devices de- airborne intercept radar [ENG] Airborne radar signed to remove particles and aerosols of spe- used to track and ‘‘lock on’’ to another aircraft cific sizes from air; examples are screens, settling to be intercepted or followed. { erbȯrn in chambers, filters, wet collectors, and electro- tərsept rādär } static precipitators. { er klēnər }airborne magnetometer [ENG] An airborne in- Airco-Hoover sweetening [CHEM ENG] Remo- strument used to measure the magnetic field of val of mercaptans from gasoline by caustic and the earth. { erbȯrn magnətämədər } water washes, then heating the dried gasolineairborne profile recorder [ENG] An electronic and passing it with some oxygen through a reac-instrument that emits a pulsed-type radar signal tor containing a slurry of diatomaceous earthfrom an aircraft to measure vertical distances impregnated with copper chloride; the oxygenbetween the aircraft and the earth’s surface. regenerates the catalyst. { erkō hüvərAbbreviated APR. Also known as terrain profile swētniŋ }recorder (TPR). { erbȯrn prōfı̄l rikȯrdər } air compressor [MECH ENG] A machine that in-airborne radar [ENG] Radar equipment carried creases the pressure of air by increasing its den-by aircraft to assist in navigation by pilotage, to sity and delivering the fluid against the con-determine drift, and to locate weather distur- nected system resistance on the discharge side.bances; a very important use is locating other { er kəmpresər }aircraft either for avoidance or attack. { er air-compressor unloader [MECH ENG] A devicebȯrn rādär } for control of air volume flowing through an airairborne waste [ENG] Vapors, gases, or particu- compressor. { er kəmpresər ənlōdər }lates introduced into the atmosphere by evapo- air-compressor valve [MECH ENG] A device forration, chemical, or combustion processes; a fre- controlling the flow into or out of the cylinderquent cause of smog and an irritant to eyes and of a compressor. { er kəmpresər valv }breathing passages. { erbȯrn wāst } air condenser [MECH ENG] 1. A steam con-air-bound [ENG] Of a pipe or apparatus, con- denser in which the heat exchange occurstaining a pocket of air that prevents or reduces through metal walls separating the steam fromthe desired liquid flow. { er bau̇nd } cooling air. Also known as air-cooled con-air brake [MECH ENG] An energy-conversion denser. 2. A device that removes vapors, suchmechanism activated by air pressure and used as of oil or water, from the airstream in a com-to retard, stop, or hold a vehicle or, generally, pressed-air line. { er kəndensər }any moving element. { er brāk } air conditioner [MECH ENG] A mechanism pri-air breaking See airblasting. { er brākiŋ } marily for comfort cooling that lowers the tem-air-breathing [MECHENG] Of an engine or aero- perature and reduces the humidity of air in build-dynamic vehicle, required to take in air for the purpose of combustion. { er brēthiŋ } ings. { er kəndishənər } 13 air conditioning air conditioning [MECH ENG] The maintenance deflecting vanes discharging supply air in various directions and planes, and arranged to promoteof certain aspects of the environment within a defined space to facilitate the function of that mixing of the supplied air with the air already in the room. { er difyüzər }space; aspects controlled include air tempera- ture and motion, radiant heat level, moisture, air-distributing acoustical ceiling [BUILD] A suspended acoustical ceiling in which the boardand concentration of pollutants such as dust, microorganisms, and gases. Also known as cli- or tile is provided with small, evenly distributed mechanical perforations; designed to provide amate control. { er kəndishəniŋ } air conveyor See pneumatic conveyor. { er desired flow of air from a pressurized plenum above. { er distribyədiŋ əküstikəl sēliŋ }kənvāər } air-cooled engine [MECH ENG] An engine air diving [ENG] A type of diving in which the diver’s breathing medium is a normal atmos-cooled directly by a stream of air without the interposition of a liquid medium. { er küld pheric mixture of oxygen and nitrogen; limited to depths of 190 feet (58 meters). { er dı̄viŋ }enjən } air-cooled heat exchanger [MECH ENG] A air drain [CIV ENG] An empty space left around the external foundation wall of a building tofinned-tube (extended-surface) heat exchanger with hot fluids inside the tubes, and cooling prevent the earth from lying against it and caus- ing dampness. { er drān }air that is fan-blown (forced draft) or fan-pulled (induced draft) across the tube bank. { er küld airdraulic [MECH ENG] Combining pneumatic and hydraulic action for operation. { erdrȯlhēt ikschānjər } air cooling [MECHENG] Lowering of air temper- ik } air drill [MECH ENG] A drill powered by com-ature for comfort, process control, or food preser- vation. { er küliŋ } pressed air. { ¦er dril } air drying [ENG] Removingmoisture fromama-air course See airway. { er kȯrs } aircraft detection [ENG] The sensing and dis- terial by exposure to air to the extent that no further moisture is released on contact with air;covery of the presence of aircraft; major tech- niques include radar, acoustical, and optical important in lumber manufacture. { ¦er drı̄iŋ } air duct See airflow duct. { ¦er dəkt }methods. { erkraft ditekshən } aircraft impactor [ENG] An instrument carried air ejector [MECH ENG] A device that uses a fluid jet to remove air or other gases, as from aby an aircraft for the purpose of obtaining sam- ples of airborne particles. { erkraft impak steam condenser. { ¦er ijektər } air eliminator [MECH ENG] In a piping system,tər } air-cure [CHEM ENG] To vulcanize at ordinary a device used to remove air from water, steam, or refrigerant. { ¦er ilimənādər }room temperatures, or without the aid of heat. { er kyür } air elutriator See air classifier. { ¦er ēlütrēādər } air engine [MECH ENG] An engine in whichair curtain [MECH ENG] A stream of high-veloc- ity temperature-controlled air which is directed compressed air is the actuating fluid. { ¦er enjən }downward across an opening; it excludes insects, exterior drafts, and so forth, prevents the transfer air entrainment [ENG] The inclusion of minute bubbles of air in cement or concrete through theof heat across it, and permits air-conditioning of a spacewith an open entrance. { er kərtən } addition of some material during grinding or mixing to reduce the surface tension of the water,air cushion [MECH ENG] A mechanical device using trapped air to arrest motion without shock. giving improved properties for the end product. { ¦er intrānmənt }{ er ku̇shən } air-cushion vehicle [MECH ENG] A transporta- air escape [DES ENG] A device that is fitted to a pipe carrying a liquid for releasing excess air;tion device supported by low-pressure, low- velocity air capable of traveling equally well over it contains a valve that controls air release while preventing loss of liquid. { er əskāp }water, ice, marsh, or relatively level land. Also known as ground-effect machine (GEM); hover- air-exhaust ventilator [MECH ENG] Any air- exhaust unit used to carry away dirt particles,craft. { er ku̇shən vēəkəl } air-cut [ENG] Referring to the inadvertent me- odors, or fumes. { er igzȯst ventəlādər } airfield [CIV ENG] The area of an airport for thechanical incorporation of air into a liquid system. { er kət } takeoff and landing of airplanes. { erfēld } air filter [ENG] A device that reduces the con-air cycle [MECHENG] A refrigeration cycle char- acterized by the working fluid, air, remaining as centration of solid particles in an airstream to a level that can be tolerated in a process or spacea gas throughout the cycle rather than being condensed to a liquid; used primarily in airplane occupancy; a component of most systems in which air is used for industrial processes, ventila-air conditioning. { er sı̄kəl } air cylinder [MECH ENG] A cylinder in which air tion, or comfort air conditioning. { er filtər } air flotation See dissolved air flotation. { eris compressed by a piston, compressed air is stored, or air drives a piston. { er siləndər } flōtāshən } airflow duct [ENG] A pipe, tube, or channelair density [MECH] The mass per unit volume of air. { er densədē } through which air moves into or out of an en- closed space. Also known as air duct. { erair diffuser [BUILD] An air distribution outlet, usually located in the ceiling and consisting of flō dəkt } 14 air lock airflow orifice [ENG] An opening through which air hp See air horsepower. air-injection reactor [MECH ENG] A unit in-air moves out of an enclosed space. { erflō ȯrəfəs } stalled in an automotive engine which mixes fresh air with hot exhaust gases in the exhaustairflow pipe [ENG] A tube through which air is conveyed from one location to another. { er manifold to react with any gasoline that has escaped unburned from the cylinders. Abbrevi-flō pı̄p } air-fuel mixture [MECH ENG] In a carbureted ated AIR. { er in¦jekshən rēaktər } air-injection system [MECH ENG] A device thatgasoline engine, the charge of air and fuel that is mixed in the appropriate ratio in the carbure- uses compressed air to inject the fuel into the cylinder of an internal combustion engine.tor and subsequently fed into the combustion chamber. { er fyül mikschər } Also known as thermactor. { er in¦jekshən sistəm }air gage [ENG] 1. A device that measures air pressure. 2. A device that compares the shape air inlet [MECH ENG] In an air-conditioning sys- tem, a device through which air is exhaustedof a machined surface to that of a reference sur- face by measuring the rate of passage of air be- from a room or building. { er ¦inlet } air-inlet valve [MECH ENG] In a heating/air-con-tween the surfaces. { er gāj } air gap [ELECTR] 1. A gap or an equivalent filler ditioning system of a motor vehicle, a valve in the plenum blower assembly that permits selec-of nonmagnetic material across the core of a choke, transformer, or other magnetic device. tion of either inside or outside air. { er ¦inlet valv }2. A spark gap consisting of two electrodes sepa- rated by air. 3. The space between the stator air knife [ENG] A device that uses a thin, flat jet of air to remove the excess coating from freshlyand rotor in a motor or generator. [ENG] 1. The distance between two components or coated paper. { er nı̄f } air-knife coating [ENG] An even film of coatingparts. 2. In plastic extrusion coating, the dis- tance from the opening of the extrusion die to left on paper after treatment with an air knife. { er ¦nı̄f kōdiŋ }the nip formed by the pressure and chill rolls. 3. The unobstructed vertical distance between air-lance [ENG] To direct a pressurized-air stream to remove unwanted accumulations, asthe lowest opening of a faucet (or the like) which supplies a plumbing fixture (such as a tank or in boiler-wall cleaning. { er lans } air leakage [MECH ENG] 1. In ductwork, airwashbowl) and the level at which the fixture will overflow. { er gap } which escapes from a joint, coupling, and such. 2. The undesired leakage or uncontrolled pas-air grating [BUILD] A fixed metal grille on the exterior of a building through which air is sage of air from a ventilation system. { er lēkəj }brought into or discharged from the building for purposes of ventilation. { er grādiŋ } airless spraying [ENG] The spraying of paint by means of high fluid pressure and special equip-air hammer See pneumatic hammer. { er ham ər } ment. Also known as hydraulic spraying. { erləs sprāiŋ }air-handling system [MECH ENG] An air-condi- tioning system in which an air-handling unit pro- air lift [MECH ENG] 1. Equipment for lifting slurry or dry powder through pipes by means ofvides part of the treatment of the air. { er ¦handliŋ sistəm } compressed air. 2. See air-lift pump. { ¦er ¦lift } air-lift hammer [MECH ENG] A gravity dropair-handling unit [MECH ENG] A packaged as- sembly of air-conditioning components (coils, hammer used in closed die forging in which the ram is raised to its starting point by means offilters, fan humidifier, and so forth) which pro- vides for the treatment of air before it is distrib- an air cylinder. { erlift hamər } air-lift pump [MECH ENG] A device composeduted. { er ¦handliŋ yünət } air heater See air preheater. { er hēdər } of two pipes, one inside the other, used to extract water from a well; the lower end of the pipes isair-heating system See air preheater. { er hēd iŋ sistəm } submerged, and air is delivered through the in- ner pipe to form a mixture of air and water whichair hoist [MECH ENG] A lifting tackle or tugger constructed with cylinders and pistons for recip- rises in the outer pipe above the water in the well; also used to move corrosive liquids, millrocating motion and air motors for rotary motion, all powered by compressed air. Also tailings, and sand. Also known as air lift. { er lift pəmp }known as pneumatic hoist. { er hȯist } air horn [MECH ENG] In an automotive engine, air line [ENG] A fault, in the form of an elon- gated bubble, in glass tubing. Also known asthe upper portion of the carburetor barrel through which entering air passes in quantities hairline. [MECH ENG] A duct, hose, or pipe that supplies compressed air to a pneumatic toolcontrolled by the choke plate and the throttle plate. { er hȯrn } or piece of equipment. { er lı̄n } air-line lubricator See line oiler. { er lı̄n lüair horsepower [MECH ENG] The theoretical (minimum) power required to deliver the speci- brəkādər } air lock [ENG] 1. A chamber capable of beingfied quantity of air under the specified pressure conditions in a fan, blower, compressor, or vac- hermetically sealed that provides for passage be- tween two places of different pressure, such asuum pump. Abbreviated air hp. { er hȯrs pau̇ər } between an altitude chamber and the outside 15 air-water jet moist air is cooled below its dew point by refrig- thermometer that uses ethyl alcohol as its work- ing substance. { alkəhȯl thərmämədər }erated water so that although the air leaves close alidade [ENG] 1. An instrument for topographicto saturation with water, it has less moisture per surveying and mapping by the plane-tableunit volume than when it entered. 2. Apparatus method. 2. Any sighting device employed forto wash particulates and soluble impurities from angular measurement. { alədād }air by passing the airstream through a liquid aligning drift [MECH ENG] A rod or bar that isbath or spray. { er washər } used for aligning parts during assembly. { əlı̄nair-water jet [ENG] A jet of mixed air and water iŋ drift }which leaves a nozzle at high velocity; used in alignment [CIV ENG] In a survey for a highway,cleaning the surfaces of concrete or rock. { ¦er railroad, or similar installation, a ground plan¦wȯdər jet } that shows the horizontal direction of the route.air-water storage tank [ENG] A water storage [ELECTR] The process of adjusting componentstank in which the air above the water is com- of a system for proper interrelationship, includ-pressed. { ¦er ¦wȯdər stȯrij taŋk } ing the adjustment of tuned circuits for properairway [BUILD] A passage for ventilation be- frequency response and the time synchroniza-tween thermal insulation and roof boards. tion of the components of a system. [ENG]{ erwā } Placing of surveying points along a straight line.air well See air shaft. { er wel } { əlı̄nmənt }Airy points [ENG] The points at which a hori- alignment correction [ENG] A correction ap-zontal rod is optionally supported to avoid its plied to the measured length of a line to allowbending. { ¦erē pȯins } for not holding the tape exactly in a vertical planeAiry stress function [MECH] A biharmonic func- of the line. { əlı̄nmənt kərekshən }tion of two variables whose second partial deriv- alignment pin [DES ENG] Pin in the center ofatives give the stress components of a body sub- the base of an octal, loctal, or other tube having a ject to a plane strain. { ¦erē stres fəŋkshən } single vertical projecting rib that aids in correctlyaisleway [CIV ENG] A passage or walkway within inserting the tube in its socket. { əlı̄nmənt a factory, storage building, or shop permitting pin } the flow of inside traffic. { ı̄lwā } alignment wire See ground wire. { əlı̄nmənt Aitken dust counter [ENG] An instrument for wı̄r } determining the dust content of the atmosphere. alkali ion diode [ENG] In testing for leaks, a de- Also known as Aitken nucleus counter. { ¦ātkən vice which senses the presence of halogen gasesdəst kau̇ntər } by the use of positive ions of alkali metal on the Aitken nucleus counter See Aitken dust counter. heated diode surfaces. { alkəlı̄ ı̄ən dı̄ōd } { ¦ātkən nüklēəs kau̇ntər } alkaline wash [CHEM ENG] The removal of im- alarm gage [ENG] A device that actuates a sig- purities from kerosine,used for illuminating pur- nal either when the steam pressure in a boiler poses, by caustic soda solution. { alkəlı̄n is too high or when the water level in a boiler wäsh } is too low. { əlärm gaj } Alkar process [CHEM ENG] Catalytic alkylation alarm system [ENG] A system which operates of aromatic hydrocarbons with olefins to pro- a warning device after the occurrence of a dan- duce alkylaromatics; for example, production of gerous or undesirable condition. { əlärm ethylbenzene from benzene and ethylene. sistəm } { alkar präsəs } alarm valve [ENG] A device that sounds an alkylate bottom [CHEM ENG] Residue from frac- alarm when water flows in an automatic sprinkler tionation of total alkylate which boils at a higher system. { əlärm valv } temperature than aviation gasolines. { al albedometer [ENG] An instrument used for the kəlāt bädəm } measurement of the reflecting power, that is, the alkylation [CHEM ENG] A refinery process for albedo, of a surface. { albədämədər } chemically combining isoparaffin with olefin Alberger process [CHEM ENG] A method of hydrocarbons. { alkəlāshən } manufacturing salt by heating brine at high pres- allège [BUILD] A part of a wall which is thinner sure and passing it to a graveler which removes than the rest, especially the spandrel under a calcium sulfate; the salt crystallizes as the pres- window. { alezh } sure is reduced and thus is separated from the Allen screw [DES ENG] A screw or bolt which brine. { älbərgər präsəs } has an axial hexagonal socket in its head. { al alcoholimeter See alcoholometer. { alkəhȯlim ən skrü } ədər } Allen wrench [DES ENG] A wrench made from alcoholmeter See alcoholometer. { alkəhȯl a straight or bent hexagonal rod, used to turn mēdər } an Allen screw. { alən rench } alcoholometer [ENG] A device, such as a form alligator shears [ENG] A cutting tool with a of hydrometer, that measures the quantity of an fixed lower blade and a movable upper blade alcohol contained in a liquid. Also known as (shearing arm) that moves in an arc around a alcoholimeter; alcoholmeter. { alkəhȯlä fulcrum pin; used mainly for shearing applica- mədər } tions that do not require great accuracy. { al əgādər shirz }alcohol thermometer [ENG] A liquid-in-glass 18 altitude-azimuth mounting alligator wrench [DES ENG] A wrench having alphatron See alpha-ray vacuum gage. { al fəträn }fixed jaws forming a V, with teeth on one or both jaws. { aləgādər rench } alt See altitude. altazimuth [ENG] An instrument equipped withallocate [IND ENG] To assign a portion of a re- source to an activity. { alōkāt } both horizontal and vertical graduated circles, for the simultaneous observation of horizontalallowable bearing value [CIV ENG] The maxi- mum permissible pressure on foundation soil and vertical directions or angles. Also known as astronomical theodolite; universal instrument.that provides adequate safety against rupture of the soil mass or movement of the foundation { altazəməth } alt-azimuth mounting See altitude-azimuth mount-of such magnitude as to impair the structure imposing the pressure. Also known as allow- ing. { alt azəməth mau̇ntiŋ } alternate energy [ENG] Any source of energyable soil pressure. { əlau̇əbəl beriŋ valyü } allowable load [MECH] The maximum force other than fossil fuels that is used for construc- tive purposes. { ȯltərnət enərjē }that may be safely applied to a solid, or is permit- ted by applicable regulators. { əlau̇əbəl lōd } alternating current [ELEC] Electric current that reverses direction periodically, usually manyallowable soil pressure See allowable bearing value. { əlau̇əbəl sȯil preshər } times per second. Abbreviated ac. { ¦ȯl tərnādiŋ ¦kərənt }allowable stress [MECH] The maximum force per unit area that may be safely applied to a alternating-current welder [ENG] A welding machine utilizing alternating current for weldingsolid. { əlau̇əbəl stres } allowance [DES ENG] An intentional difference purposes. { ¦ȯltərnādiŋ ¦kərənt weldər } alternating stress [MECH] A stress produced inin sizes of two mating parts, allowing clearance usually for a film of oil, for running or sliding a material by forces which are such that each force alternately acts in opposite directions.fits. { əlau̇əns } allowed hours See standard hour. { əlau̇d au̇ { ȯltərnādiŋ stres } altigraph [ENG] A pressure altimeter that has aərz } allowed time [IND ENG] Amount of time al- recording mechanism to show the changes in altitude. { altəgraf }lowed each employee for personal needs during a work cycle. { əlau̇d tı̄m } altimeter [ENG] An instrument which deter- mines the altitude of an object with respect toalloy junction [ELECTR] A junction produced by alloying one or more impurity metals to a semi- a fixed level, such as sea level; there are two common types: the aneroid altimeter and theconductor to form a p or n region, depending on the impurity used. Also known as fused junc- radio altimeter. { altimədər } altimeter corrections [ENG] Corrections whichtion. { alȯi jəŋkshən } alloy-junction diode [ELECTR] A junction diode must be made to the readings of a pressure al- timeter to obtain true altitudes; involve horizon-made by placing a pill of doped alloying material on a semiconductor material and heating until tal pressure gradient error and air temperature error. { altimədər kərekshənz }the molten alloy melts a portion of the semicon- ductor, resulting in a pn junction when the dis- altimeter setting [ENG] The value of atmos- pheric pressure to which the scale of an aneroidsolved semiconductor recrystallizes. Also known as fused-junction diode. { alȯi ¦jəŋk altimeter is set; after United States practice, the pressure that will indicate airport elevation whenshən dı̄ōd } all-translational system [CONT SYS] A simple the altimeter is 10 feet (3 meters) above the runway (approximately cockpit height). { alrobotic system in which there is no rotation of the robot or its components during movements timədər sediŋ } altimeter-setting indicator [ENG] A precisionof the robot’s body. { ¦ȯl tranzlāshənəl sis təm } aneroid barometer calibrated to indicate directly the local altimeter setting. { altimədər ¦sedall-weather airport [CIV ENG] An airport with facilities to permit the landing of qualified air- iŋ indəkādər } altimetry [ENG] The measurement of heights incraft and aircrewmen without regard to opera- tional weather limits. { ȯl ¦wethər erpȯrt } the atmosphere (altitude), generally by an altim- eter. { altimətrē }alpha [ELECTR] The ratio between the change in collector current and the change in emitter altitude Abbreviated alt. [ENG] 1. Height, measured as distance along the extended earth’scurrent of a transistor. { alfə } alpha cutoff frequency [ELECTR] The frequency radius above a given datum, such as average sea level. 2. Angular displacement above theat the high end of a transistor’s range at which current amplification drops 3 decibels below its horizon measured by an altitude curve. { al tətüd }low-frequency value. { alfə kədȯf frēkwən sē } altitude azimuth [ENG] An azimuth determined by solution of the navigational triangle with alti-alpha-ray vacuum gage [ENG] An ionization gage in which the ionization is produced by alpha tude, declination, and latitude given. { al tətüd azəməth }particles emitted by a radioactive source, instead of by electrons emitted from a hot filament; used altitude-azimuth mounting [ENG] A two-axis telescope mounting in which the azimuth of thechiefly for pressures from 103 to 10 torrs. Also known as alphatron. { alfə rā vakyüm gāj } direction in which the telescope is pointed is 19 altitude chamber determined by rotation about a vertical axis and of specified sizes established as a standard in the United States. Also known as Briggs pipethe corresponding altitude is determined by ro- tation about a horizontal axis; computer-con- thread. { əmerəkən standərd pı̄p thred } American standard screw thread [DES ENG]trolled motors must move the telescope in both altitude and azimuth to compensate for the Screw thread whose dimensions conform to those of a particular series of specified sizes es-earth’s rotation. Also known as alt-azimuth mounting. { ¦altətüd azəməth mau̇ntiŋ } tablished as a standard in the United States; used for bolts, nuts, and machine screws.altitude chamber [ENG] A chamber within which the air pressure, temperature, and so on { əmerəkən standərd skrü thred } American system drill See churn drill. { əmerəcan be adjusted to simulate conditions at differ- ent altitudes; used for experimentation and test- kən ¦sistəm dril } American Table of Distances [ENG] Publisheding. { altətüd chāmbər } altitude curve [ENG] The arc of a vertical circle data concerning the safe storage of explosives and ammunition. { əmerəkən tābəl əv disbetween the horizon and a point on the celestial sphere, measured upward from the horizon. tənsəz } ammeter [ENG] An instrument for measuring{ altətüd kərv } altitude datum [ENG] The arbitrary level from the magnitude of electric current flow. Also known as electric current meter. { amēdər }which heights are reckoned. { altətüd dad əm } ammonia absorption refrigerator [MECH ENG] An absorption-cycle refrigerator which uses am-altitude difference [ENG] The difference be- tween computed and observed altitudes, or be- monia as the circulating refrigerant. { əmōn yə əb¦sorpshən rifrijərādər }tween precomputed and sextant altitudes. Also known as altitude intercept; intercept. ammonia compressor [MECH ENG] A device that decreases the volume of a quantity of gas-{ altətüd difrəns } altitude intercept See altitude difference. { al eous ammonia by the amplification of pressure; used in refrigeration systems. { əmōnyətətüd intərsept } aluminize [ENG] To apply a film of aluminum kəmpresər } ammonia condenser [MECH ENG] A device into a material, such as glass. { əlümənı̄z } AM See amplitude modulation. an ammonia refrigerating system that raises the pressure of the ammonia gas in the evaporatingA-mast [ENG] An A-shaped arrangement of up- right poles for supporting amechanismdesigned coil, conditions the ammonia, and delivers it to the condensing system. { əmōnyə kəndensto lift heavy loads. { ā mast } ambient [ENG] Surrounding; especially, of or ər } ammonia liquor [CHEM ENG] Water solution ofpertaining to the environment about a flying air- craft or other body but undisturbed or unaffected ammonia, ammonium compounds, and impuri- ties, obtained from destructive distillation of bi-by it, as in ambient air or ambient temperature. { ambēənt } tuminous coal. { əmōnyə likər } ammonia meter [ENG] A hydrometer designedAmerican basement [BUILD] A basement lo- cated above ground level and containing the specifically to determine the density of aqueous ammonia solutions. { əmōnyə mēdər }building’s main entrance. { əmerəkən bās mənt } ammonia synthesis [CHEM ENG] Chemical combination of nitrogen and hydrogen gases atAmerican bond [CIV ENG] A bond in which ev- ery fifth, sixth, or seventh course of a wall con- high temperature and pressure in the presence of a catalyst to form ammonia. { əmōnyə sinsists of headers and the other courses consist of stretchers. Also known as common bond; thəsəs } ammonia valve [ENG] A valve that is resistantScotch bond. { əmerəkən bänd } American caisson See box caisson. { əmerə to corrosion by ammonia. { əmōnyə valv } ammonoxidation See ammoxidation. { akən kāsän } American filter See disk filter. { əmerəkən fil mənäksədāshən } ammoxidation [CHEM ENG] A process in whichtər } American melting point [CHEM ENG] A temper- mixtures of propylene, ammonia, and oxygen are converted in the presence of a catalyst, with acry-ature 3F (1.7C) higher than the American Soci- ety for Testing and Materials Method D87 paraf- lonitrile as the primary product. Also known as ammonoxidation; oxyamination. { amäksəfin-wax melting point. { əmerəkən meltiŋ pȯint } dāshən } amortize [IND ENG] To reduce gradually an obli-American standard beam [CIV ENG] A type of I beam made of hot-rolled structural steel. gation, such as a mortgage, by periodically pay- ing a part of the principal as well as the interest.{ əmerəkən standərd bēm } American standard channel [CIV ENG] A C- { amərtı̄z } amount limit [IND ENG] In a test for a fixedshaped structural member made of hot-rolled structural steel. { əmerəkən standərd quantity of work, the time required to complete the work or the total amount of work that canchanəl } American standard pipe thread [DES ENG] be completed in an unlimited time. { əmau̇nt limət }Taper, straight, or dryseal pipe thread whose di- mensions conform to those of a particular series amp See amperage; ampere. { amp } 20 angel echo through such devices as rods, cables, and chains. springs; an example is the Dines anemometer. { ¦anəməbı̄əgraf }{ aŋkər pı̄l } anchor plate [CIV ENG] Ametal or wooden plate anemoclinometer [ENG] A type of instrument which measures the inclination of the wind tofastened to or embedded in a support, such as a floor, and used to hold a supporting cable the horizontal plane. { ¦anəmōklə¦näm ədər }firmly. { aŋkər plāt } anchor rod See anchor bolt. { aŋkər räd } anemogram [ENG] A record made by an anemograph. { ənēməgram }anchor station See anchorage. { aŋkər stā shən } anemograph [ENG] 1. An instrument which re- cords wind velocities. 2. A recording anemom-anchor tower [CIV ENG] 1. A tower which is a part of a crane staging or stiffleg derrick and eter. { ənēməgraf } anemometer [ENG] A device which measuresserves as an anchor. 2. A tower that supports and anchors an overhead transmission line. air speed. { anəmämədər } anemoscope [ENG] An instrument for indicat-{ aŋkər tau̇ər } anchor wall See deadman. { aŋkər wȯl } ing the direction of the wind. { ənēməskōp } anemovane [ENG] A combined contact ane-AND circuit See AND gate. { and sərkət } AND gate [ELECTR] A circuit which has two or mometer and wind vane used in the Canadian Meteorological Service. { ¦anəmō¦vān }more input-signal ports and which delivers an output only if and when every input signal port is aneroid [ENG] 1. Containing no liquid or using no liquid. 2. See aneroid barometer. { anəsimultaneously energized. Also known as AND circuit; passive AND gate. { and gāt } rȯid } aneroid altimeter [ENG] An altimeter con-AND/NORgate [ELECTR] A single logic element whose operation is equivalent to that of two taining an aneroid barometer that actuates the indicator. { anərȯid altimədər }AND gates with outputs feeding into a NOR gate. { ¦and ¦nȯr gāt } aneroid barograph [ENG] An aneroid barome- ter arranged so that the deflection of the aneroidAND NOT gate [ELECTR] A coincidence circuit that performs the logic operation AND NOT, capsule actuates a pen which graphs a record on a rotating drum. Also known as aneroidograph;under which a result is true only if statement A is true and statement B is not. Also known as barograph; barometrograph. { anərȯid bar əgraf }A AND NOT B gate. { ¦and ¦nät gāt } AND-OR circuit [ELECTR] Gating circuit that aneroid barometer [ENG] A barometer which utilizes an aneroid capsule. Also known as an-produces a prescribed output condition when several possible combined input signals are ap- eroid. { anərȯid bərämədər } aneroid calorimeter [ENG] A calorimeter thatplied; exhibits the characteristics of the AND gate and the OR gate. { ¦and ¦ȯr sərkət } uses a metal of high thermal conductivity as a heat reservoir. { anərȯid kalərimədər }AND-OR-INVERT gate [ELECTR] A logic circuit with four inputs, a1, a2, b1, and b2, whose output aneroid capsule [ENG] A thin, disk-shaped box or capsule, usually metallic, partially evacuatedis 0 only if either a1 and a2 or b1 and b2 are 1. Abbreviated A-O-I gate. { ¦and ¦ȯr invərt gāt } and sealed, held extended by a spring, which expands and contracts with changes in atmos-Andrade’s creep law [MECH] A lawwhich states that creep exhibits a transient state in which pheric or gas pressure. Also known as bellows. { anərȯid kapsəl }strain is proportional to the cube root of time and then a steady state in which strain is propor- aneroid diaphragm [ENG] A thin plate, usually metal, covering the end of an aneroid capsuletional to time. { andrādz krēp lȯ } Andrews’s curves [THERMO] A series of iso- and moving axially as the ambient gas pressure increases or decreases. { anərȯid diəfram }therms for carbon dioxide, showing the depen- dence of pressure on volume at various tempera- aneroid flowmeter [ENG] A mechanism to measure fluid flow rate by pressure of the fluidtures. { andrüz kərvz } anechoic chamber [ENG] 1. A test room in against a bellows counterbalanced by a cali- brated spring. { anərȯid flōmēdər }which all surfaces are lined with a sound-ab- sorbing material to reduce reflections of sound aneroid liquid-level meter [ENG] A mechanism to measure fluid depth by pressure of the fluidto a minimum. Also known as dead room; free- field room. 2. A room completely lined with a against a bellows which in turn acts on amanom- eter or signal transmitter. { anərȯid ¦likwədmaterial that absorbs radio waves at a particular frequency or over a range of frequencies; used ¦levəl medər } aneroidograph See aneroid barograph. { anprincipally at microwave frequencies, such as for measuring radar beam cross sections. { ¦an ərȯidəgraf } aneroid valve [MECH ENG] A valve actuated orə¦kōik chāmbər } anelasticity [MECH] Deviation from a propor- controlled by an aneroid capsule. { anərȯid valv }tional relationship between stress and strain. { ¦anəlas¦tisədē } angel echo [ENG] A radar echo from a region where there are no visible targets; may be causedanemobiagraph [ENG] A recording pressure- tube anemometer in which the wind scale of the by insects, birds, or refractive index variations in the atmosphere. { ānjəl ekō }float manometer is linear through the use of 23 angle back-pressure valve angle back-pressure valve [MECHENG] A back- joint between two surfaces meeting at an angle pressure valve with its outlet opening at right of less than 180. { aŋgəl filət } angles to its inlet opening. { aŋgəl bak angle fishplates [CIV ENG] Plates which join the preshər valv } rails and prevent the rail joint from sagging angle bar [BUILD] An upright bar at themeeting where heavy cars and locomotives are used. of two faces of a polygonal window, bay window, Also known as angle; angle bar. { aŋgəl or bow window. { aŋgəl bär } fishplāts } angle bead [BUILD] A strip, usually of metal or angle float [ENG] A trowel having two edge sur- wood, set at the corner of a plaster wall to protect faces bent at 90; used to finish corners in freshly the corner or serve as a guide to float the plaster poured concrete and in plastering. { aŋgəl flush with it. { aŋgəl bēd } flōt } angle beam [ENG] Ultrasonic waves transmit- angle gauge [CIV ENG] A template used to set ted for the inspection of a metallic surface at an or check angles in building construction. { aŋ angle measured from the beam center line to a gəl gāj } normal to the test surface. { aŋgəl bēm } angle gear See angular gear. { aŋgəl gēr } angle blasting [ENG] Sandblasting, or the like, angle globe valve [ENG] A globe valve having at an angle of less that 90. { aŋgəl blastiŋ } an angular configuration that permits it to be angle block [ENG] A small block of wood used fitted at bends in pipework. { ¦aŋgəl ¦glōb to fasten adjacent pieces, usually at right angles, ¦valv } or glued into the corner of a wooden frame to angle hip tile See arris hip tile. { aŋgəl hip tı̄l } stiffen it. Also known as glue block. { aŋ angle iron [CIV ENG] 1. An L-shaped cleat or gəl bläk } brace. 2. A length of steel having a cross sec- angle board [DES ENG] A board whose surface tion resembling the letter L. { aŋgəl ı̄ərn } is cut at a desired angle; serves as a guide for angle joint [ENG] A joint between two pieces of cutting or planing other boards at the same lumber which results in a change in direction. angle. { aŋgəl bȯrd } { aŋgəl jȯint }angle bond [CIV ENG] A tie used to bond ma- angle lacing [CIV ENG] A system of lacing in sonry work at wall corners. { aŋgəl bänd } which angle irons are used in place of bars.angle brace [ENG] A brace across the interior { aŋgəl lāsiŋ }angle of two members that meet at an angle. angle method of adjustment [ENG] A methodAlso known as angle tie. { aŋgəl brās } of adjustment of observations which determinesangle brick [ENG] Any brick having an oblique corrections to observed angles. { aŋgəlshape to fit an oblique, salient corner. { aŋ methəd əv əjəsmənt }gəl brik } angle of action [MECH ENG] The angle of revo-angle clip [CIV ENG] A short strip of angle iron lution of either of two wheels in gear duringused to secure structural elements at right which any particular tooth remains in contact.angles. { aŋgəl klip } { aŋgəl əv akshən }angle closer [ENG] A specially shaped brick angle of advance See angular advance. { aŋgəlused to close the bond at the corner of a wall. əv ədvans }{ aŋgəl klōzər } angle of approach [CIV ENG] The maximumangle collar [DES ENG] A cast-iron pipe fitting angle of an incline ontowhich a vehicle canmovewhich has a socket at each end for joining with from a horizontal plane without interference.the spigot ends of two pipes that are not in [MECH ENG] The angle that is turned throughalignment. { aŋgəl kälər } by either of paired wheels in gear from the firstangle-control section See crossover. { aŋgəl contact between a pair of teeth until the pitchkən¦trōl sekshən } points of these teeth fall together. { aŋgəlangle divider [DES ENG] A square for setting or əv əprōch }bisecting angles; one side is an adjustable angle of bite See angle of nip. { aŋgəl əv bı̄t }hinged blade. { aŋgəl dəvı̄dər } angle of departure [CIV ENG] The maximumangle dozer [MECHENG] A power-operatedma- angle of an incline fromwhich a vehicle canmovechine fitted with a blade, adjustable in height onto a horizontal plane without interference,and angle, for pushing, sidecasting, and spread- such as from rear bumpers. [ELECTR] Seeing loose excavatedmaterial as for opencast pits, angle of radiation. { aŋgəl əv dipärchər }clearing land, or leveling runways. Also known angle of depression [ENG] The angle in a verti-as angling dozer. { aŋgəldōzər } cal plane between the horizontal and a descend-angle equation [ENG] A condition equation ing line. Also known as depression angle; de-which expresses the relationship between the scending vertical angle; minus angle. { aŋgəlsum of the measured angles of a closed figure əv dipreshən }and the theoretical value of that sum, the un- angle of elevation [ENG] The angle in a verticalknowns being the corrections to the observed plane between the local horizontal and an as-directions or angles, depending on which are cending line, as from an observer to an object;used in the adjustment. Also known as triangle used in astronomy, surveying, and so on. Alsoequation. { aŋgəl ikwāzhən } known as ascending vertical angle; elevationangle fillet [ENG] A wooden strip, triangular in cross section, which is used to cover the internal angle. { aŋgəl əv eləvāshən } 24 angular advance angle of external friction [ENG] The angle be- angle paddle [ENG] A hand tool used to finish a plastered surface. { aŋgəl padəl }tween the abscissa and the tangent of the curve representing the relationship of shearing resist- angle plate [DES ENG] An L-shaped plate or a plate having an angular section. { aŋgəl plāt }ance to normal stress acting between soil and the surface of another material. Also known as angle post [BUILD] A railing support used at a landing or other break in the stairs. { aŋgəlangle of wall friction. { aŋgəl əv ekstərnəl frikshən } pōst } angle press [MECH ENG] A hydraulic plastics-angle of fall [MECH] The vertical angle at the level point, between the line of fall and the base molding press with both horizontal and vertical rams; used to produce complex moldings withof the trajectory. { aŋgəl əv fȯl } angle of impact [MECH] The acute angle be- deep undercuts. { aŋgəl press } angle rafter [BUILD] A rafter, such as a hip rafter,tween the tangent to the trajectory at the point of impact of a projectile and the plane tangent at the angle of the roof. { aŋgəl raftər } angle section [CIV ENG] A structural steel mem-to the surface of the ground or target at the point of impact. { aŋgəl əv impakt } ber having an L-shaped cross section. { aŋgəl sekshən }angle of nip [MECH ENG] The largest angle that will just grip a lump between the jaws, rolls, or angle-stem thermometer [ENG] A device used to measure temperatures in oil-custody tanks;mantle and ring of a crusher. Also known as angle of bite; nip. { aŋgəl əv nip } the angle of the calibrated stem may be 90 or greater to the sensitive portion of the thermome-angle of obliquity See angle of pressure. { aŋgəl əv ōblikwədē } ter, as needed to fit the tank shell contour. { aŋgəl ¦stem thərmämədər }angle of orientation [MECH] Of a projectile in flight, the angle between the plane determined angle stile [BUILD] A narrow strip of wood used to conceal the joint between a wall and a verticalby the axis of the projectile and the tangent to the trajectory (direction of motion), and the wood surface which makes an angle with the wall, as at the edge of a corner cabinet. { aŋvertical plane including the tangent to the trajec- tory. { aŋgəl əv ȯrēəntāshən } gəl stı̄l } angle structure [CIV ENG] A method of buildingangle of pressure [DES ENG] The angle be- tween the profile of a gear tooth and a radial a tower for mechanical strength in which braces are placed at angles with respect to the verticalline at its pitch point. Also known as angle of obliquity. { aŋgəl əv preshər } support rods. { aŋgəl strəkchər } angle strut [CIV ENG] An angle-shaped struc-angle of recess [MECH ENG] The angle that is turned through by either of two wheels in gear, tural member which is designed to carry a com- pression load. { aŋgəl strət }from the coincidence of the pitch points of a pair of teeth until the last point of contact of the angle valve [DES ENG] A manually operated valve with its outlet opening oriented at rightteeth. { aŋgəl əv rēses } angle of repose [ENG] See angle of rest. angles to its inlet opening; used for regulating the flow of a fluid in a pipe. { aŋgəl valv }[MECH] The angle between the horizontal and the plane of contact between two bodies when angle variable [MECH] The dynamical variable w conjugate to the action variable J, defined onlythe upper body is just about to slide over the lower. Also known as angle of friction. { aŋ for periodic motion. { aŋgəl verēəbəl } angling dozer See angle dozer. { aŋgliŋ dōzər }gəl əv ripōz } angle of rest [ENG] The maximum slope at angstrom [MECH] A unit of length, 1010 meter, used primarily to express wavelengths of opticalwhich a heap of any loose or fragmented solid material will stand without sliding, or will come spectra. Abbreviated A; Å. Also known as tenthmeter. { aŋstrəm }to rest when poured or dumped in a pile or on a slope. Also known as angle of repose. { aŋ Ångström compensation pyrheliometer [ENG] A pyrheliometer consisting of two identical Man-gəl əv rest } angle of thread [DES ENG] The angle occurring ganin strips, one shaded, the other exposed to sunlight; an electrical current is passed throughbetween the sides of a screw thread, measured in an axial plane. { aŋgəl əv thred } the shaded strip to raise its temperature to that of the exposed strip, and the electric power re-angle of torsion [MECH] The angle through which a part of an object such as a shaft or wire quired to accomplish this is a measure of the solar radiation. { ȯŋstrəm kämpənsāshənis rotated from its normal position when a torque is applied. Also known as angle of twist. { aŋ ¦pı̄rhēlēämədər } angular acceleration [MECH] The time rate ofgəl əv tȯrshən } angle of twist See angle of torsion. { aŋgəl əv change of angular velocity. { aŋgyələr aksel ərāshən }twist } angle of wall friction See angle of external friction. angular accelerometer [ENG] An accelerome- ter that measures the rate of change of angular{ aŋgəl əv ¦wȯl frikshən } angle of wrap [DES ENG] On a band brake velocity between two objects under observation. { aŋgyələr akselərämədər }mechanism, the distance, expressed in degrees, that the brake band wraps around the brake angular advance [MECH ENG] The amount by which the angle between the crank of a steamflange. { aŋgəl əv rap } 25 antiskid plate [ENG] The condition for which the impedance apparent gravity See acceleration of gravity. of a given electric, acoustic, or dynamic system { əparənt gravədē } is very high, approaching infinity. { antērez apparent motion See relative motion. { əparənt ənəns } mōshən } antiskid plate [ENG] A sheet of metal roughed apparent source See effective center. { əparənt on both sides and placed between piled objects, sȯrs } such as boxes in a freight car, to prevent sliding. apparent weight [MECH] For a body immersed { ¦antē¦skid ¦plāt } in a fluid (such as air), the resultant of the gravi- antismudge ring [BUILD] A frame attached tational force and the buoyant force of the fluid around a ceiling-mounted air diffuser, to mini- acting on the body; equal in magnitude to the mize the formation of rings of dirt on the ceiling. true weight minus the weight of the displaced { ¦antē¦sməj riŋ } fluid. { əparənt wāt } antitheft device [MECH ENG] A piece of equip- appliance [ENG] A piece of equipment that ment installed on an automotive vehicle in order draws electric or other energy and produces a to prevent or slow down theft; designs include desired work-saving or other result, such as an mechanical locks on the steering wheel and igni- electric heater, a radio, or an electronic range. tion switch as well as other means of shutting { əplı̄əns } off the ignition system, shutting off fuel flow, or appliance panel [ENG] In electric systems, a sounding an alarm. { antētheft divı̄s } metal housing containing two or more devices anvil [ENG] 1. The part of a machine that ab- (such as fuses) for protection against excessive sorbs the energy delivered by a sharp force or current in circuits which supply portable electric blow. 2. The stationary end of a micrometer appliances. { əplı̄əns panəl } caliper. { anvəl } applied research [ENG] Research directed to- AOQL See average outgoing quality limit. ward using knowledge gained by basic research aperiodic waves [ELEC] The transient current to make things or to create situations that will wave in a series circuit with resistance R, induc- serve a practical or utilitarian purpose. tance L, and capacitance C when R2C 4L. { əplı̄d risərch } { ¦apirē¦ädik wāvz } applied strategic research [ENG] Researchaperture [ELECTR] An opening through which done to provide a basic understanding of a cur-electrons, light, radio waves, or other radiation rent applied project. { əplı̄d strətējik rican pass. { apəchər } sərch }aperture disk [ENG] A disk with a small round applied trim [BUILD] Supplementary and sepa-opening used in a densitometer to vary the rate decorative strips of wood or moldings ap-amount of light or the area to be measured. plied to the face or sides of a frame, such as a{ apəchər disk } doorframe. { əplı̄d trim }apex [ENG] In architecture or construction, the approach [MECH ENG] The difference betweenhighest point, peak, or tip of any structure. the temperature of the water leaving a cooling{ āpeks } tower and the wet-bulb temperature of the sur-apical angle [MECH] The angle between the rounding air. { əprōch }tangents to the curve outlining the contour of a approach signal [CIV ENG] A railway signalprojectile at its tip. { apikəl aŋgəl } warning an engineer of a signal ahead that dis-API scale [CHEMENG] The American Petroleum plays a restrictive indication. { əprōch sigInstitute hydrometer scale for the measurement nəl }of the specific gravity of liquids; used primarily approach vector [CONT SYS] A vector that de-in the American petroleum industry. { ¦ā¦pē¦ı̄ scribes the orientation of a robot gripper andskāl } points in the direction from which the gripperapophorometer [ENG] An apparatus used to approaches a workpiece. { əprōch vektər }identify minerals by sublimation. { apə apron [BUILD] 1. A board on an interior wallfərämədər } beneath a windowsill. 2. The vertical rear panelapothecaries’ dram See dram. { əpäthəkerēz of a sink attached to a wall. 3. A section of adram } concrete slab extending beyond the face of aapothecaries’ ounce See ounce. { əpäthəker building on adjacent ground. Also known asēz au̇ns } skirt; skirting. 4. A vertical panel installed be-apothecaries’ pound See pound. { əpäthəker hind a sink or lavatory. [CIV ENG] 1. A hard-ēz pau̇nd } surfaced area, usually paved, adjacent to a shipapparent expansion [THERMO] The expansion or the like, used to park, load, unload, or serviceof a liquid with temperature, as measured in a vehicles. 2. A covering of a material such asgraduated container without taking into account concrete or timber over soil to prevent erosionthe container’s expansion. { əparənt ikspan by flowing water, as at the bottom of a dam.shən } 3. A concrete or wooden shield that is situatedapparent force [MECH] A force introduced in a along the bank of a river, along a sea wall, orrelative coordinate system in order that New- below a dam. 4. In a railroad system, a bridgeton’s laws be satisfied in the system; examples structure that carries tracks and is hinged to landare the Coriolis force and the centrifugal force incorporated in gravity. { əparənt fȯrs } for connecting the deck of a railroad-car ferry 28 architectural engineering to the shore. [MECH ENG] A plate serving to readings obtained on that part of the arc begin- ning at zero and extending in the direction usu-protect or cover a machine. { āprən } ally considered positive are popularly said toapron conveyor [MECH ENG] A conveyor used be on the arc, and those beginning at zero andfor carrying granular or lumpy material and con- extending in the opposite direction are said tosisting of two strands of roller chain separated by be off the arc. { ärk }overlapping plates, forming the carrying surface, arc force [MECH] The force of a plasma arcwith sides 2–6 inches (5–15 centimeters) high. through a nozzle or opening. { ärk fȯrs }{ āprən kənvāər } arch [CIV ENG] A structure curved and so de-apron feeder [MECH ENG] A limited-length ver- signed that when it is subjected to vertical loads,sion of apron conveyor used for controlled-rate its two end supports exert reaction forces withfeeding of pulverized materials to a process or inwardly directed horizontal components; com-packaging unit. Also known as plate-belt mon uses for the arch are as a bridge, supportfeeder; plate feeder. { āprən fēdər } for a roadway or railroad track, or part of a build-apron flashing [BUILD] 1. The flashing that cov- ing. { ärch } ers the joint between a vertical surface and a arch band [CIV ENG] Any narrow elongated sur- sloping roof, as at the lower edge of a chimney. face forming part of or connected with an arch. 2. The flashing that diverts water from a vertical { ärch band } surface into a gutter. { āprən flashiŋ } arch bar [BUILD] 1. A curved chimney bar. apron lining [BUILD] The piece of boarding 2. A curved bar in a window sash. { ärch bar } which covers the rough apron piece of a stair- arch beam [CIV ENG] A curved beam, used in case. { āprən lı̄niŋ } construction, with a longitudinal section apron piece [BUILD] A beam that supports a bounded by two arcs having different radii and landing or a series of winders in a staircase. centers of curvature so that the beam cross sec- { āprən pēs } tion is larger at either end than at the center. apron rail [BUILD] A lock rail having a raised { ärch bēm } ornamental molding. { āprən rāl } arch brace [BUILD] A curved brace, usually apron wall [BUILD] In an exterior wall, a panel used in pairs to support a roof frame and give which extends downward from a windowsill to the effect of an arch. { ärch brās } the top of a window below. { āprən wȯl } arch bridge [CIV ENG] A bridge having arches as the main supports. { ärch brij }AQL See acceptable quality level. arch center [CIV ENG] A temporary structure foraqualung [ENG] A self-contained underwater support of the parts of a masonry or concretebreathing apparatus (scuba) of the demand or arch during its construction. { ärch ¦sentər }open-circuit type developed by J.Y. Cousteau. arch corner bead [BUILD] A corner bead which{ akwələŋ } is cut on the job; used to form and reinforce theaqueduct [CIV ENG] An artificial tube or chan- curved portion of arch openings. { ärch ¦kȯrnel for conveying water. { akwədəkt } nər bēd }arbitration [IND ENG] A semijudicial means of arch dam [CIV ENG] A dam having a curved facesettling labor-management disputes in which on the downstream side, the curve being roughlyboth sides agree to be bound by the decision of a portion of a cylinder whose axis is vertical.one or more neutral persons selected by some { ärch dam }method mutually agreed upon. { arbətrā arched construction [BUILD] A method of con-shən } struction relying on arches and vaults to supportarbor [MECH ENG] 1. A cylindrical device posi- walls and floors. { ¦ärcht kənstrəkshən }tioned between the spindle and outer bearing arch girder [CIV ENG] A normal H-section steelof a milling machine and designed to hold a girder bent to a circular shape. { ärch gərdər }milling cutter. 2. A shaft or spindle used to arch-gravity dam [CIV ENG] An arch dam stabi-hold a revolving cutting tool or the work to be lized by gravity due to great mass and breadth cut. { arbər } of the base. { ärch ¦gravədē dam }arbor collar [ENG] A cylindrical spacer that Archimedes’ screw [MECH ENG] A device for positions and secures a revolving cutter on an raising water by means of a rotating broad- arbor. { arbər kälər } threaded screw or spirally bent tube within an arbor hole [DES ENG] A hole in a revolving cut- inclined hollow cylinder. { ¦ärkə¦mēdēz skrü } ter or grinding wheel for mounting it on an arbor. arching [CIV ENG] 1. The transfer of stress from { ärbər hōl } a yielding part of a soil mass to adjoining less- arbor press [MECH ENG] A machine used for yielding or restrained parts of the mass. 2. A forcing an arbor or a mandrel into drilled or system of arches. 3. The arched part of a struc- bored parts preparatory to turning or grinding. ture. { ärchiŋ } Also known as mandrel press. { ärbər pres } architectural acoustics [CIV ENG] The science arbor support [ENG] A device to support the of planning and building a structure to ensure outer end or intermediate point of an arbor. the most advantageous flow of sound to all lis- { ärbər səpȯrt } teners. { ¦ärkə¦tekchərəl əküstiks } arc See electric arc.The graduated scale of an instru- architectural engineering [CIV ENG] The branch of engineering dealing primarily with buildingment for measuring angles, as a marine sextant; 29 architectural millwork materials and components and with the design area by aerial photography having parallel over- lapping flight lines and stereoscopic overlap be-of structural systems for buildings, in contrast tween exposures in the line of flight. { erēəto heavy construction such as bridges. { ¦är kəvrij }kə¦tekchərəl enjəniriŋ } area drain [CIV ENG] A receptacle designed toarchitectural millwork [CIV ENG] Ready-made collect surface or rain water from an open area.millwork especially fabricated to meet the speci- { erēə ¦drān }fications for a particular job, as distinguished area landfill [CIV ENG] A sanitary landfill opera-from standard or stock items or sizes. Also tion that takes care of the solid waste of moreknown as custom millwork. { ¦ärkə¦tekchərəl than one municipality in a region. { erēəmilwərk } landfil } architectural volume [CIV ENG] The cubic con- area light [CIV ENG] 1. A source of light with tent of a building calculated by multiplying the significant dimensions in two directions, such floor area by the height. { ¦ärkə¦tekchərəl as a windowor luminous ceiling. 2.A light used välyəm } to illuminate large areas. { erēə lı̄t } architecture [ENG] 1. The art and science of de- area meter [ENG] A mechanism to measure signing buildings. 2. The product of this art and fluid flow rate through a fixed-area conduit by science. { ärkətekchər } the movement of a weighted piston or float sup- arch press [MECH ENG] A punch press having ported by the flowing fluid; includes rotameters an arch-shaped frame to permit operations on and piston-type meters. { erēə mēdər } area of use [ENG] For a balance depending onwide work. { ärch pres } gravitational acceleration, an area that includesarch rib [CIV ENG] One of a set of projecting a sufficient number of locations providing amolded members subdividing the undersurface mean value for the gravitational acceleration ofof an arch. { ärch rib } the given balance. { erēə əv yüs }arch ring [CIV ENG] A curved member that pro- area survey [ENG] A survey of areas largevides the main support of an arched structure. enough to require loops of control. { erēə{ ärch riŋ } ¦sərvā }arch truss [CIV ENG] A truss having the form of area triangulation [ENG] A system of triangula-an arch or arches. { ärch trəs } tion designed to progress in every direction fromarc of action See arc of contact. { ¦ärk əv akshən } a control point. { erēə trı̄aŋgyəlāshən }arc of approach [DES ENG] In toothed gearing, area wall [CIV ENG] A retaining wall around anthe part of the arc of contact along which the areaway. { erēə wȯl }flank of the driving wheel contacts the face of areaway [CIV ENG] An open space at subsurface the driven wheel. { ¦ärk əv əprōch } level adjacent to a building, providing access to arc of contact [MECH ENG] 1. The angular dis- and utilities for a basement. { erēəwā } tance over which a gear tooth travels while it is Argand lamp [ENG] A gas lamp having a tube- in contact with its mating tooth. Also known as shaped wick, allowing a current of air inside as arc of action. 2. The angular distance a pulley well as outside the flame. { ärgän lamp } travels while in contact with a belt or rope. argentometer [ENG] A hydrometer used to find { ¦ärk əv käntakt } the amount of silver salt in a solution. { är arc of recess [DES ENG] In toothed gearing, the jəntämədər } part of the arc of contact wherein the face of the Arkansas stone [ENG] A whetstone made of driving wheel touches the flank of the driven Arkansas stone, for sharpening edged tools. { ärkənsȯ stōn }wheel. { ¦ärk əv rēses } ARL See acceptable reliability level.arcometer [ENG] A device for determining the arm [CONT SYS] A robot component consitingdensity of a liquid by measuring the apparent of an interconnected set of links and poweredweight loss of a solid of known mass and volume joints that move and support the wrist socketwhen it is immersed in the liquid. { ärkäm and end effector. [ELEC] See branch. [ENGədər } ACOUS] See tone arm. { ärm }arc process [CHEM ENG] A former process that arm conveyor [MECH ENG] A conveyor in theused electric arcs for fixation (oxidation) of form of an endless belt or chain to which areatmospheric nitrogen to manufacture nitric acid. attached projecting arms or shelves which carry{ ¦ärk ¦präsəs } the materials. { ¦ärm kənvāər } arcticization [ENG] The preparation of equip- arm elevator [MECH ENG] A chain elevator with ment for operation in an environment of ex- protruding arms to cradle fixed-shape objects, tremely low temperatures. { ¦ärdikı̄zāshən } such as drums or barrels, as they are moved arc triangulation [ENG] A system of triangula- upward. { ¦ärm eləvādər } tion in which an arc of a great circle on the armored faceplate [DES ENG] A tamper-proof surface of the earth is followed in order to tie in faceplate or lock front, mortised in the edge of two distant points. { ärk triaŋgyəlāshən } a door to cover the lock mechanism. { är are [MECH] A unit of area, used mainly in agri- mərd fāsplāt } culture, equal to 100 square meters. { är } armored front [DES ENG] A lock front used on mortise locks that consists of two plates, thearea coverage [ENG] Complete coverage of an 30 asynchronous control aspiration psychrometer [ENG] A psychrome- astatic governor See isochronous governor. { ā stadik gəvənər }ter in which the ventilation is provided by a suc- tion fan. { aspərāshən sikrämədər } astatic gravimeter [ENG] A sensitive gravimeter designed to measure small changes in gravity.aspiration thermograph [ENG] A thermograph in which ventilation is provided by a suction fan. { āstadik gravimədər } astatic magnetometer [ENG] A magnetometer{ aspərāshən thərməgraf } aspirator [ENG] Any instrument or apparatus for determining the gradient of a magnetic field by measuring the difference in reading from twothat utilizes a vacuum to draw up gases or granu- lar materials. { aspərādər } magnetometers placed at different positions. { āstadik magnətämədər }assay balance [ENG] A sensitive balance used in the assaying of gold, silver, and other precious astatic wattmeter [ENG] An electrodynamic wattmeter designed to be insensitive to uniformmetals. { asā baləns } assembling bolt [CIV ENG] A threaded bolt for external magnetic fields. { āstadik wätmēd ər }holding together temporarily the several parts of a structure during riveting. { əsembliŋ bōlt } astatized gravimeter [ENG] A gravimeter, sometimes referred to as unstable, where theassembly [MECH ENG] A unit containing the component parts of a mechanism, machine, or force of gravity is maintained in an unstable equilibrium with the restoring force. { assimilar device. { əsemblē } assembly line [IND ENG] Amass-production ar- tətı̄zd gravimədər } astern [ENG] To the rear of an aircraft, vehicle,rangement whereby the work in process is pro- gressively transferred from one operation to the or vessel; behind; from the back. { əstərn } astragal [BUILD] 1. A small convex moldingnext until the product is assembled. { əsem blē lı̄n } decorated with a string of beads or bead-and- reel shapes. 2. A plain bead molding. 3. Aassembly-line balancing [IND ENG] Assigning numbers of operators or machines to each oper- member, or combination of members, fixed to one of a pair of doors or casement windows toation of an assembly line so as to meet the required production rate with a minimum of idle cover the joint between the meeting stiles and to close the clearance gap. { astrəgəl }time. { əsemblē lı̄n balənsiŋ } assembly machine [MECH ENG] A machine in astragal front [DES ENG] A lock front which is shaped to fit the edge of a door with an astragala manufacturing facility that produces a configu- ration of some practical value from discrete com- molding. { astrəgəl ¦frənt } astral lamp [ENG] An Argand lamp designed soponents. { əsemblē məshēn } assembly method [IND ENG] The technique that its light is not prevented from reaching a table beneath it by the flattened annular reser-used to assemble a manufactured product, such as hand assembly, progressive line assembly, voir holding the oil. { astrəl lamp } astroballistics [MECH] The study of phenom-and automatic assembly. { əsemblē meth əd } ena arising out of the motion of a solid through a gas at speeds high enough to cause ablation;assembly time [ENG] 1. The elapsed time after the application of an adhesive until its strength for example, the interaction of a meteoroid with the atmosphere. { ¦astrōbəlistiks }becomes effective. 2. The time elapsed in per- forming an assembly or subassembly operation. astrolabe [ENG] An instrument designed to ob- serve the positions and measure the altitudes{ əsemblē tı̄m } assets [IND ENG] All the resources, rights, and of celestial bodies. { astrəlāb } astronomical instruments [ENG] Specific kindsproperty owned by a person or a company; the book value of these items as shown on the bal- of telescopes and ancillary equipment used by astronomers to study the positions, motions,ance sheet. { asets } assignable cause [IND ENG] Any identifiable and composition of stars and members of the solar system. { astrənäməkəl instrəfactor which causes variation in a process out- side the predicted limits, thereby altering qual- məns } astronomical theodolite See altazimuth. { asity. { əsı̄nəbəl kȯz } assize [CIV ENG] 1. A cylindrical block of stone trənäməkəl thēädəlı̄t } astronomical traverse [ENG] A survey traverseforming one unit in a column. 2. A layer of stonework. { əsı̄z } in which the geographic positions of the stations are obtained from astronomical observations,Assmann psychrometer [ENG] A special form of the aspiration psychrometer in which the ther- and lengths and azimuths of lines are obtained by computation. { astrənäməkəl trəvərs }mometric elements are well shielded from radia- tion. { äsmän sı̄krämədər } asymmetric rotor [MECH ENG] A rotating ele- ment for which the axis (center of rotation) isassumed plane coordinates [ENG] A local plane-coordinate system set up at the conve- not centered in the element. { ¦āsə¦metrik rōdər }nience of the surveyor. { əsümd ¦plān kōȯrdnəts } asymmetric top [MECH] A system in which all three principal moments of inertia are different.astatic galvanometer [ENG] A sensitive galva- nometer designed to be independent of the { ¦āsə¦metrik täp } asynchronous control [CONT SYS] A method ofearth’s magnetic field. { āstadik galvənäm ədər } control in which the time allotted for performing 33 asynchronous device an operation depends on the time actually re- atomic moisture meter [ENG] An instrument that measures the moisture content of coal in-quired for the operation, rather than on a prede- termined fraction of a fixed machine cycle. stantaneously and continuously by bombarding it with neutrons and measuring the neutrons{ āsiŋkrənəs kəntrōl } asynchronous device [CONT SYS] A device in which bounce back to a detector tube after strik- ing hydrogen atoms of water. { ətämik mȯiswhich the speed of operation is not related to any frequency in the system to which it is connected. chər mēdər } atomic power plant See nuclear power plant.{ āsiŋkrənəs divı̄s } asynchronous operation [ELECTR] An opera- { ətämik pau̇ər plant } atomization [MECH ENG] The mechanical sub-tion that is started by a completion signal from a previous operation, proceeds at the maximum division of a bulk liquid or meltable solid, such as certain metals, to produce drops, which varyspeed of the circuits until finished, and then generates its own completion signal. { āsiŋ in diameter depending on the process from un- der 10 to over 1000 micrometers. { adəkrənəs äpərāshən } asynchronous timing [IND ENG] A simulation məzāshən } atomizer [MECH ENG] A device that produces amethod for queues in which the system model is updated at each arrival or departure, resulting mechanical subdivision of a bulk liquid, as by spraying, sprinkling, misting, or nebulizing.in the master clock being increased by a variable amount. { āsiŋkrənəs tı̄miŋ } { adəmı̄zər } atomizer burner [MECH ENG] A liquid-fuelat See technical atmosphere. ata [MECH] A unit of absolute pressure in the burner that atomizes the unignited fuel into a fine spray as it enters the combustion zone.metric technical system equal to 1 technical atmosphere. { atə } { adəmı̄zər ¦bərnər } atomizer mill [MECH ENG] A solids grinder, theathermalize [ENG] To make independent of temperature or of thermal effects. { ¦āthər product from which is a fine powder. { ad əmı̄zər mil }məlı̄z } atm See atmosphere. atomizing humidifier [MECH ENG] A humidifier in which tiny particles of water are introducedatmidometer See atmometer. { atmədäməd ər } into a stream of air. { adəmı̄ziŋ hyümid əfı̄ər }atmometer [ENG] The general name for an in- strument which measures the evaporation rate atomprobe [ENG] An instrument for identifying a single atom or molecule on a metal surface; itof water into the atmosphere. Also known as atmidometer; evaporation gage; evaporimeter. consists of a field ion microscope with a probe hole in its screen opening into a mass spectrom-{ ətmämədər } atmosphere [MECH] A unit of pressure equal to eter; atoms that are removed from the specimen by pulsed field evaporation fly through the probe101.325 kilopascals, which is the air pressure measured at mean sea level. Abbreviated atm. hole and are detected in the mass spectrometer. { adəm prōb }Also known as standard atmosphere. { at məsfir } attached thermometer [ENG] A thermometer which is attached to an instrument to determineatmospheric cooler [MECHENG] A fluids cooler that utilizes the cooling effect of ambient air its operating temperature. { ətacht thərmäm ədər }surrounding the hot, fluids-filled tubes. { ¦at mə¦sfirik külər } attemperation [ENG] The regulation of the tem- perature of a substance. { ətempərāshən }atmospheric distillation [CHEM ENG] Distilla- tion operation conducted at atmospheric pres- attemperation of steam [MECH ENG] The con- trolled cooling, in a steam boiler, of steam atsure, in contrast to vacuum distillation or pres- sure distillation. { ¦atmə¦sfirik distəlā the superheater outlet or between the primary and secondary stages of the superheater to regu-shən } atmospheric impurity [ENG] An extraneous late the final steam temperature. { ətempərā shən əv stēm }substance that is mixed as a contaminant with the air of the atmosphere. { ¦atmə¦sfirik im attenuate [ENG ACOUS] To weaken a signal by reducing its level. { ətenyəwāt }pyürədē } atmospheric noise [ELECTR] Noise heard dur- attenuation [ELEC] The exponential decrease with distance in the amplitude of an electricaling radio reception due to atmospheric interfer- ence. { ¦atmə¦sfirik nȯiz } signal traveling along a very long uniform trans- mission line, due to conductor and dielectricatmospheric steam curing [ENG] The steam curing of concrete or cement products at atmo- losses. [ENG] A process by which a material is fabricated into a thin, slender configuration,spheric pressure, usually at a maximum ambient temperature between 100 and 200F (40 and such as forming a fiber from molten glass. { ətenyəwāshən }95C). { ¦atmə¦sfirik stēm kyu̇riŋ } atomic force microscope [ENG] A device for attic [BUILD] The part of a building immediately below the roof and entirely or partly within themapping surface atomic structure by measuring the force acting on the tip of a sharply pointed roof framing. { adik } attic tank [BUILD] An open tank which is in-wire or other object that is moved over the sur- face. { ə¦tämik ¦fȯrs mı̄¦krəskōp } stalled above the highest plumbing fixture in a 34 autogenous grinding building and which supplies water to the fixtures consisting of a plate or diaphragm that is placed against the teeth and transmits sound vibrationsby gravity. { adik taŋk } atticurge [BUILD] Of a doorway, having jambs to the inner ear. { ȯdəfōn } auger [DES ENG] 1. A wood-boring tool thatwhich are inclined slightly inward, so that the opening is wider at the threshold than at the consists of a shank with spiral channels ending in two spurs, a central tapered feed screw, andtop. { adəkərj } attic ventilator [BUILD] A mechanical fan lo- a pair of cutting lips. 2. A large augerlike tool for boring into soil. { ȯgər }cated in the attic space of a residence; usually moves large quantities of air at a relatively low auger bit [DES ENG] a A bit shaped like an auger but without a handle; used for wood boring andvelocity. { adik ventəlādər } attraction gripper [CONT SYS] A robot compo- for earth drilling. { ȯgər bit } auger boring [ENG] 1. The hole drilled by thenent that uses adhesion, suction, or magnetic forces to grasp a workpiece. { ətrakshən use of auger equipment. 2. See auger drilling. { ȯgər bȯriŋ }gripər } attribute sampling [IND ENG] A quality-control auger conveyor See screw conveyor. { ȯgər kənvāər }inspectionmethod in which the sampled articles are classified only as defective or nondefective. auger drilling [ENG] A method of drilling in which penetration is accomplished by the cut-{ atrəbyüt sampliŋ } attributes testing [ENG] A reliability test proce- ting or gouging action of chisel-type cutting edges forced into the substance by rotation ofdure in which the items under test are classified according to qualitative characteristics. { a the auger bit. Also known as auger boring. { ȯgər driliŋ }trəbyüts testiŋ } attrition mill [MECH ENG] A machine in which auger packer [MECH ENG] A feed mechanism that uses a continuous auger or screw inside amaterials are pulverized between two toothed metal disks rotating in opposite directions. cylindrical sleeve to feed hard-to-flow granulated solids into shipping containers, such as bags or{ ətrishən mil } Atwood machine [MECH ENG] A device com- drums. { ȯgər pakər } auget [ENG] A priming tube, used in blasting.prising a pulley over which is passed a stretch- free cord with a weight hanging on each end. Also spelled augette. { ȯzhet } augette See auget. { ȯzhet }{ atwu̇d məshēn } audible leak detector [ENG] A device used as auralization See virtual acoustics. { ȯrələzā shən }an auxiliary to the main leak detector for conver- sion of the output signal into audible sound. autoadaptivity [CONT SYS] The ability of an ad- vanced robot to sense the environment, accept{ ¦ȯdəbəl lēk ditektər } audio-frequency meter [ENG] One of a number commands, and analyze and execute operations. { ¦ȯdȯədaptivədē }of types of frequency meters usable in the audio range; for example, a resonant-reed frequency autoclave [ENG] An airtight vessel for heating and sometimes agitating its contents under highmeter. { ȯdēō ¦frēkwənsē mēdər } audiometer [ENG] An instrument composed of steam pressure; used for industrial processing, sterilizing, and cooking with moist or dry heatan oscillator, amplifier, and attenuator and used tomeasure hearing acuity for pure tones, speech, at high temperatures. { ȯdōklāv } autoclave curing [ENG] Steam curing of con-and bone conduction. { ȯdēämədər } audio-modulated radiosonde [ENG] A radio- crete products, sand-lime brick, asbestos cement products, hydrous calcium silicate insulationsonde with a carrier wave modulated by audio- frequency signals whose frequency is controlled products, or cement in an autoclave at maximum ambient temperatures generally between 340by the sensing elements of the instrument. { ¦ȯdēo¦mäjəlādəd ¦rādēōsänd } and 420F (170 and 215C). { ȯdōklāv kyu̇r iŋ }audio patch bay [ENG ACOUS] Specific patch panels provided to terminate all audio circuits autoclave molding [ENG] A method of curing reinforced plastics that uses an autoclave withand equipment used in a channel and technical control facility; this equipment can also be found 50–100 pounds per square inch (345–690 kilo- pascals) steam pressure to set the resin. { ȯdin transmitting and receiving stations. { ȯdē ō ¦pach bā } ōklāv ¦mōldiŋ } autocorrelation [ELECTR] A technique used toaudio spectrometer See acoustic spectrometer. { ȯdēō spekträmədər } detect cyclic activity in a complex signal. { ¦ȯd ōkärəlāshən }audio system See sound-reproducing system. { ȯdēō sistəm } autofrettage [ENG] A process formanufacturing gun barrels; prestressing the metal increases theaudio taper [ENG ACOUS] A special type of po- tentiometer used in a volume-control apparatus load at which its permanent deformation occurs. { ȯdōfredij }to compensate for the nonlinearity of human hearing and give the impression of a linear in- autogenous grinding [MECH ENG] The second- ary grinding of material by tumbling the materialcrease in audibility as volume is raised. Also known as linear taper. { ȯdēō tāpər } in a revolving cylinder, without balls or bars tak- ing part in the operation. { ȯtäjənəs grı̄ndaudiphone [ENG ACOUS] A device that enables persons with certain types of deafness to hear, iŋ } 35 automatic-type belt-tensioning device a telephone-type dial operated. { ¦ȯdə¦madik automotive frame [ENG] The basic structure of tüniŋ sistəm } all automotive vehicles, except tractors, which automatic-type belt-tensioning device [MECH is supported by the suspension and upon which ENG] Any device which maintains a predeter- or attached to which are the power plant, trans- mined tension in a conveyor belt. { ¦ȯdə¦mad mission, clutch, and body or seat for the driver. ik tı̄p belt ¦tenshəniŋ divı̄s } { ¦ȯdə¦mōdiv frām } automatic volume compressor See volume com- automotive ignition system [MECH ENG] A de- pressor. { ¦ȯdə¦madik välyəm kəmpresər } vice in an automotive vehicle which initiates the automatic volume expander See volume expander. chemical reaction between fuel and air in the { ¦ȯdə¦madik välyəm ikspandər } cylinder charge. { ¦ȯdə¦mōdiv ignishən sis automatic wet-pipe sprinkler system [ENG] A təm } sprinkler system, all of whose parts are filled automotive steering [MECH ENG] Mechanical with water at sufficient pressure to provide an means by which a driver controls the course of a immediate continuous discharge if the system moving automobile, bus, truck, or tractor. { ¦ȯdis activated. { ¦ȯdə¦madik ¦wet ¦pı̄p spriŋklər ə¦mōdiv stiriŋ }sistəm } automotive suspension [MECH ENG] Theautomatic zero setting [ENG] A system for au- springs and related parts intermediate betweentomatic correction of zero-point drifts or for com- the wheels and frame of an automotive vehiclepensation of soiling of load receivers on a bal- that support the frame on the wheels and absorbance by means of a special accessory compo- road shock caused by passage of the wheels overnent. { ¦ȯdə¦madik zirō sediŋ } irregularities. { ¦ȯdə¦mōdiv səspenchən }automation [ENG] 1. The use of technology to automotive transmission [MECH ENG] A deviceease human labor or extend the mental or physi- for providing different gear or drive ratios be-cal capabilities of humans. 2. Themechanisms, tween the engine and drive wheels of an automo-machines, and systems that save or eliminate tive vehicle, a principal function being to enablelabor, or imitate actions typically associated with the vehicle to accelerate from rest through a widehuman beings. { ȯdəmāshən } speed range while the engine operates within itsautomechanism [CONT SYS] A machine or most effective range. { ¦ȯdə¦mōdiv tranzother device that operates automatically or un- mishən }der control of a servomechanism. { ¦ȯdōmek ənizəm } automotive vehicle [MECH ENG] A self-pro- automobile [MECH ENG] A four-wheeled, track- pelled vehicle ormachine for land transportation less, self-propelled vehicle for land transporta- of people or commodities or for moving materi- tion of as many as eight people. Also known als, such as a passenger car, bus, truck, motorcy- as car. { ȯdəməbēl } cle, tractor, airplane, motorboat, or earthmover. automobile chassis [MECH ENG] The automo- { ¦ȯdə¦mōdiv vēəkəl } bile frame, together with the wheels, power train, autonomous robot [ENG] A robot that not only brakes, engine, and steering system. { ȯdə can maintain its own stability as it moves, but məbēl chasē } also can plan its movements. { ȯ¦tänəməs automotive air conditioning [MECH ENG] A sys- rōbät } tem for maintaining comfort of occupants of autonomous vehicle [ENG] A vehicle that is automobiles, buses, and trucks, limited to air able to plan its path and to execute its plan cooling, air heating, ventilation, and occasion- without human intervention. { ȯ¦tänəməs vē ally dehumidification. { ¦ȯdə¦mōdiv er kən əkəl } dishəniŋ } autopatrol [MECH ENG] A self-powered blade automotive body [ENG] An enclosure mounted grader. Also known as motor grader. { ȯdō on and attached to the frame of an automotive pətrōl } vehicle, to contain passengers and luggage, or autoradar plot See chart comparison unit. { ¦ȯd in the case of commercial vehicles the commodi- ō¦rādär plät } ties being carried. { ¦ȯdə¦mōdiv bädē } autoradiography [ENG] A technique for de-automotive brake [MECH ENG] A friction mech- tecting radioactivity in a specimen by producinganism that slows or stops the rotation of the an image on a photographic film or plate. Alsowheels of an automotive vehicle, so that tire known as radioautography. { ¦ȯdōrādēägtraction slows or stops the vehicle. { ¦ȯd rəfē }əmōdiv brāk } autorail [MECH ENG] A self-propelled vehicleautomotive engine [MECH ENG] The fuel-con- having both flange wheels and pneumatic tiressuming machine that provides the motive power to permit operation on both rails and roadways.for automobiles, airplanes, tractors, buses, and { ȯdōrāl }motorcycles and is carried in the vehicle. { ¦ȯd autoranging [ENG] Automatic switching of aə¦mōdiv enjən } multirange meter from its lowest to the nextautomotive engineering [MECH ENG] The higher range, with the switching process re-branch ofmechanical engineering concerned pri- peated until a range is reached for which themarily with the special problems of land trans- full-scale value is not exceeded. Also known asportation by a four-wheeled, trackless, automo- tive vehicle. { ¦ȯdə¦mōdiv enjəniriŋ } automatic ranging. { ȯdōrānjiŋ } 38 avalanche noise autoreducing tachymeter [ENG] A class of ta- availability [SYS ENG] The probability that a system is operating satisfactorily at any point inchymeter by which horizontal and height dis- tances are read simultaneously. { ¦ȯdōri¦düs time, excluding times when the system is under repair. { əvāləbilədē }iŋ təkimədər } autorotation [MECH] 1. Rotation about any axis availability ratio [IND ENG] The ratio of the amount of time a system is actually available forof a body that is symmetrical and exposed to a uniform airstream and maintained only by aero- use to the amount of time it is supposed to be available. { əvāləbilədē rāshō }dynamic moments. 2. Rotation of a stalled symmetrical airfoil parallel to the direction of available draft [MECH ENG] The usable differ- ential pressure in the combustion air in a fur-the wind. { ¦ȯdōrōtāshən } autosled [MECH ENG] A propeller-driven ma- nace, used to sustain combustion of fuel or to transport products of combustion. { əvāləchine equipped with runners and wheels and adaptable to use on snow, ice, or bare roads. bəl draft } available energy [MECHENG] Energy which can{ ȯdōsled } autostability [CONT SYS] The ability of a device in principle be converted to mechanical work. { əvāləbəl enərjē }(such as a servomechanism) to hold a steady position, either by virtue of its shape and propor- available heat [MECH ENG] The heat per unit mass of a working substance that could be trans-tions, or by control by a servomechanism. { ¦ȯdōstəbilədē } formed into work in an engine under ideal condi- tions for a given amount of heat per unit massauxanometer [ENG] An instrument used to de- tect and measure plant growth rate. { ȯg furnished to the working substance. { əvālə bəl hēt }zənämədər } auxiliary dead latch [DES ENG] A supplemen- available motions inventory [IND ENG] A list of all motions available to a human for performingtary latch in a lock which automatically dead- locks themain latch bolt when the door is closed. a specific task. { ə¦vāləbəl mōshənz inven tȯrē }Also known as auxiliary latch bolt; deadlocking latch bolt; trigger bolt. { ȯgzilyərē ded lach } avalanche [ELECTR] 1. The cumulative process in which an electron or other charged particleauxiliary latch bolt See auxiliary dead latch. { ȯg zilyərē lach bōlt } accelerated by a strong electric field collides with and ionizes gasmolecules, thereby releasing newauxiliary power plant [MECH ENG] Ancillary equipment, such as pumps, fans, and soot blow- electrons which in turn have more collisions, so that the discharge is thus self-maintained. Alsoers, used with the main boiler, turbine, engine, waterwheel, or generator of a power-generating known as avalanche effect; cascade; cumulative ionization; electron avalanche; Townsend ava-station. { ȯgzilyərē pau̇ər plant } auxiliary rafter [BUILD] A member strengthen- lanche; Townsend ionization. 2. Cumulative multiplication of carriers in a semiconductor asing the principal rafter in a truss. { ȯgzilyərē raftər } a result of avalanche breakdown. Also known as avalanche effect. { avəlanch }auxiliary reinforcement [CIV ENG] In a pre- stressed structural member, any reinforcement avalanche breakdown [ELECTR] Nondestruc- tive breakdown in a semiconductor diode whenin addition to that whose function is pre- stressing. { ȯgzilyərē rēənfȯrsmənt } the electric field across the barrier region is strong enough so that current carriers collideauxiliary rim lock [DES ENG] A secondary or ex- tra lock that is surface-mounted on a door to with valence electrons to produce ionization and cumulative multiplication of carriers. { avprovide additional security. { ȯgzilyərē rim läk } əlanch brākdau̇n } avalanche diode [ELECTR] A semiconductorauxiliary rope-fastening device [MECH ENG] A device attached to an elevator car, to a counter- breakdown diode, usually made of silicon, in which avalanche breakdown occurs across theweight, or to the overhead dead-end rope-hitch support, that automatically supports the car or entire pn junction and voltage drop is then essen- tially constant and independent of current; thecounterweight in case the fastening for the wire rope (cable) fails. { ȯgzilyərē rōp fasəniŋ two most important types are IMPATT and TRA- PATT diodes. { avəlanch dı̄ōd }divı̄s } auxiliary thermometer [ENG] A mercury-in- avalanche effect See avalanche. { avəlanch ifekt }glass thermometer attached to the stem of a reversing thermometer and read at the same avalanche impedance [ELECTR] The complex ratio of the reverse voltage of a device that under-time as the reversing thermometer so that the correction to the reading of the latter, resulting goes avalanche breakdown to the reverse cur- rent. { avəlanch impēdəns }from change in temperature since reversal, can be computed. { ȯgzilyərē thərmämədər } avalanche-induced migration [ELECTR] A tech- nique of forming interconnections in a field-pro-auxograph [ENG] An automatic device that re- cords changes in the volume of a body. { ȯk grammable logic array by applying appropriate voltages for shorting selected base-emitter junc-səgraf } auxometer [ENG] An instrument that measures tions. { avəlanch in¦düsd mı̄grāshən } avalanche noise [ELECTR] 1. A junction phe-the magnification of a lens system. { ȯksäm ədər } nomenon in a semiconductor in which carriers 39 avalanche oscillator in a high-voltage gradient develop sufficient en- and a downstream hole for the static pressure ergy to dislodge additional carriers through reference. { avrijiŋ pētō tüb } physical impact; this agitation creates ragged aviationmethod [ENG] Determination of knock- current flows which are indicated by noise. limiting power, under lean-mixture conditions, 2. The noise produced when a junction diode is of fuels used in spark-ignition aircraft engines. operated at the onset of avalanche breakdown. { āvēāshən methəd } { avəlanch nȯiz } avionics [ENG] The design and production of avalanche oscillator [ELECTR] An oscillator airborne electrical and electronic devices; term that uses an avalanche diode as a negative resist- is derived from aviation electronics. { ā ance to achieve one-step conversion from direct- vēäniks } current to microwave outputs in the gigahertz avogram [MECH] A unit of mass, equal to 1 range. { avəlanch ¦äsəlādər } gram divided by the Avogadro number. { a avalanche photodiode [ELECTR] A photodiode vəgram } operated in the avalanche breakdown region to avoidable delay [IND ENG] An interruption un- achieve internal photocurrent multiplication, der the control of the operator during the normal thereby providing rapid light-controlled switch- operating time. { əvȯidəbəl dilā } ing operation. { avəlanch fōdōdı̄ōd } avoirdupois pound See pound. { avərdəpȯiz avalanche protector [MECH ENG] Guard plates pau̇nd } installed on an excavator to prevent loose mate- avoirdupoisweight [MECH] The system of units rial from sliding into the wheels or tracks. { av which has been commonly used in English-əlanch prətektər } speaking countries for measurement of the mass avalanche transistor [ELECTR] A transistor that of any substance except precious stones, pre- utilizes avalanche breakdown to produce chain ciousmetals, and drugs; it is based on the pound generation of charge-carrying hole-electron (approximately 453.6 grams) and includes the pairs. { avəlanch tranzistər } short ton (2000 pounds), long ton (2240 pounds),avalanche voltage [ELECTR] The reverse volt- ounce (one-sixteenth pound), and dram (one- age required to cause avalanche breakdown in sixteenth ounce). { avərdəpȯiz wāt } a pn semiconductor junction. { avəlanch awl [DES ENG] A point tool with a short woodenvōltij } handle used to mark surfaces and to make smallaverage acoustic output [ENG ACOUS] Vibra- holes, as in leather or wood. { ȯl }tory energy output of a transducer measured by awning window [BUILD] A window consisting ofa radiation pressure balance; expressed in terms a series of vertically arranged, top-hinged rectan-of watts per unit area of the transducer face. gular sections; designed to admit air while ex-{ avrij əküstik au̇tpu̇t } cluding rain. { ȯniŋ windō }average noise figure [ELECTR] Ratio in a trans- ax [DES ENG] An implement consisting of aducer of total output noise power to the portion heavy metal wedge-shaped head with one or twothereof attributable to thermal noise in the input cutting edges and a relatively long wooden han-termination, the total noise being summed over dle; used for chopping wood and felling trees.frequencies from zero to infinity, and the noise { aks }temperature of the input termination being axed brick [ENG] A brick, shaped with an ax,standard (290 K). { avrij nȯiz figyər } that has not been trimmed. Also known asaverage outgoing quality limit [IND ENG] The rough-axed brick. { ¦akst ¦brik }average quality of all lots that pass quality in- axhammer [DES ENG] An ax having one cuttingspection, expressed in terms of percent defec- edge and one hammer face. { akshamər }tive. Abbreviated AOQL. { avrij au̇tgōiŋ axial fan [MECH ENG] A fan whose housing con-kwälədē limət } fines the gas flow to the direction along the rotat-average power output [ELECTR] Radio-fre- ing shaft at both the inlet and outlet. { aksēquency power, in an audio-modulation transmit- əl fan }ter, delivered to the transmitter output terminals, axial-flow compressor [MECH ENG] A fluidaveraged over a modulation cycle. { avrij compressor that accelerates the fluid in a direc-pau̇ər au̇tpu̇t } tion generally parallel to the rotating shaft.average sample number [IND ENG] An antici- { aksēəl flō kəmpresər }pated number of pieces that must be inspected axial-flow pump [MECHENG] A pump having anto determine the acceptability of a particular lot. axial-flow or propeller-type impeller; used when{ avrij ¦sampəl nəmbər } maximum capacity and minimum head are de-averaging [CONT SYS] The reduction of noise sired. Also known as propeller pump. { akreceived by a robot sensor by screening it over sēəl flō pəmp }a period of time. { av rijiŋ } axial force diagram [CIV ENG] In statics, aaveraging device [ENG] A device for obtaining graphical representation of the axial load actingthe arithmetic mean of a number of readings, as at each section of a structural member, plottedon a bubble sextant. { avrijiŋ divı̄s } to scale and with proper sign as an ordinate ataveraging pitot tube [ENG] A flowmeter that each point of the member and along a referenceconsists of a rod extending across a pipe with line representing the length of the member.several interconnected upstream holes, which simulate an array of pitot tubes across the pipe, { aksēəl ¦fȯrs diəgram } 40 B plate or strap which is screwed to the face ofbackacter See backhoe. { bakaktər } a shutter or door. Also known as flap hinge.backband [BUILD] A piece of millwork used { bakflap hinj }around a rectangular window or door casing as backflow [CIV ENG] The flow of water or othera cover for the gap between the casing and the liquids, mixtures, or substances into the distrib-wall or as a decorative feature. Also known as uting pipes of a potable supply of water frombackbend. { bakband } any other than its intended source. { bakflō }backbend [BUILD] 1. At the outer edge of a backflow connection [CIV ENG] Any arrange-metal door or window frame, the face which re- ment of pipes, plumbing fixtures, drains, and soturns to the wall surface. 2. See backband. forth, in which backflow can occur. { bakflō{ bakbend } kənekshən }back bias [ELECTR] 1. Degenerative or regener- backflow preventer See vacuum breaker. { bakative voltage which is fed back to circuits before flō priventər }its originating point; usually applied to a control backflow valve See backwater valve. { bakflōanode of a tube or other device. 2. Voltage ap- valv }plied to a grid of a tube (or tubes) or electrode backfurrow [CIV ENG] In an excavation proce-of another device to reduce a condition which dure, the first cut made on undisturbed land.has been upset by some external cause. { bak { bakfərō }bı̄əs } back gearing [MECH ENG] The technique of us-back boxing See backlining. { bak ¦bäksiŋ } ing gears on machine tools to obtain an increasebackbreak See overbreak. { bakbrāk } in the number of speed changes that can beback check [DES ENG] In a hydraulic door gotten with cone belt drives. { bak giriŋ }closer, a mechanism that slows the speed with background discrimination [ENG] The ability ofwhich a door may be opened. { bak chek } a measuring instrument, circuit, or other devicebackdigger See backhoe. { bak¦digər } to distinguish signal from background noise.back-draft damper [MECH ENG] A damper with { bakgrau̇nd diskrimənāshən }blades actuated by gravity, permitting air to pass background noise [ENG] The undesired signalsthrough them in one direction only. { bak that are always present in an electronic or otherdraft dampər } system, independent of whether or not the de-back edging [ENG] Cutting through a glazed sired signal is present. { bakgrau̇nd nȯiz }ceramic pipe by first chipping through the glaze background returns [ENG] 1. Signals on a radararound the outside and then chipping the pipe screen from objects which are of no interest.itself. { bak ejiŋ } 2. See clutter. { bakgrau̇nd ritərnz }back end See thrust yoke. { bak end } background signal [ENG] The output of a leakbackfill [CIV ENG] Earth refilling a trench or an detector caused by residual gas to which theexcavation around a building, bridge abutment, detector element reacts. { bakgrau̇nd sigand the like. { bakfil } nəl }back fillet [BUILD] The return of the margin of back gutter [BUILD] A gutter installed on thea groin, doorjamb, or window jamb when it proj- uphill side of a chimney on a sloping roof toects beyond a wall. { bak filət } backfire [CIV ENG] A fire that is started in order divert water around the chimney. { bak gəd ər }to burn against and cut off a spreading fire. [ELECTR] See arcback. [ENG] Momentary back hearth [BUILD] That part of the hearth (or floor) which is contained within the fireplacebackward burning of flame into the tip of a torch. Also known as flashback. [MECH ENG] In an itself. Also known as inner hearth. { bak härth }internal combustion engine, an improperly timed explosion of the fuel mixture in a cylinder, backhoe [MECH ENG] An excavator fitted with a hinged arm to which is rigidly attached a bucketespecially one occurring during the period that the exhaust or intake valve is open and resulting that is drawn toward the machine in operation. Also known as backacter; backdigger; dragshovel;in a loud detonation. { bakfı̄r } backflap hinge [DES ENG] A hinge having a flat pullshovel. { bak hō } Copyright 2003 by The McGraw-Hill Companies, Inc. Click Here for Terms of Use. backing backing [CIV ENG] 1. The unexposed, roughma- backlog [IND ENG] 1. An accumulation of or- ders promising future work and profit. 2. Ansonry surface of a wall that is faced with finer accumulation of unprocessed materials or un-work. 2. The earth backfill of a retaining wall. performed tasks. { bakläg }[ELECTR] Flexiblematerial, usually cellulose ac- back mixing [CHEM ENG] The tendency of re-etate or polyester, used on magnetic tape as the acted chemicals to intermingle with unreactedcarrier for the oxide coating. { bakiŋ } feed in reactors, such as stirred tanks, packedbacking board [BUILD] In a suspended acousti- towers, and baffled tanks. { bak miksiŋ }cal ceiling, a flat sheet of gypsum board to which back nailing [BUILD] Nailing the plies of a built-acoustical tile is attached by adhesive or me- up roof to the substrate to prevent slippage.chanical means. { bakiŋ bȯrd } { bak nāliŋ }backing brick [CIV ENG] A relatively low-quality back nut [DES ENG] 1. A threaded nut, one sidebrick used behind face brick or other masonry. of which is dished to retain a grommet; used in{ bakiŋ brik } forming a watertight pipe joint. 2. A lockingbacking off [ENG] Removing excessive body nut on the shank of a pipe fitting, tap, or valve.metal from badly worn bits. { bakiŋ ¦ȯf } { bak nət }backing plate [ENG] A plate used to support back off [ENG] 1. To unscrew or disconnect.the hardware for the cavity used in plastics injec- 2. To withdraw the drill bit from a borehole.tion molding. { bakiŋ plāt } 3. To withdraw a cutting tool or grinding wheelbacking pump [MECH ENG] A vacuum pump, in from contact with the workpiece. { bak ȯf }a vacuum system using two pumps in tandem, back order [IND ENG] 1.An order held for futurewhich works directly to the atmosphere and re- completion. 2. A new order placed for pre-duces the pressure to an intermediate value, viously unavailable materials of an old order.usually between 100 and 0.1 pascals. Also { bak ȯrdər }known as fore pump. { bakiŋ pəmp } backplastering [BUILD] A coat of plaster ap-backing ring [ENG] A strip of metal attached at plied to the back side of lath, opposite the fin- a pipe joint at the root of a weld to prevent ished surface. { bakplastriŋ } spatter and to ensure the integrity of the weld. backplate [BUILD] A plate, usually metal or { bakiŋ riŋ } wood, which serves as a backing for a structural backing space [ENG] Space between a fore member. { bakplāt } pump and a diffusion pump in a leak-testing backplate lamp holder [DES ENG] A lamp system. { bakiŋ spās } holder, integrally mounted on a plate, which is backing-space technique [ENG] Testing for designed for screwing to a flat surface. { bak leaks by connecting a leak detector to the back- plāt lamp hōldər } ing space. { bakiŋ spās teknēk } back pressure [MECH] Pressure due to a force backing up [CIV ENG] In masonry, the laying of that is operating in a direction opposite to that backing brick. { bakiŋ ¦əp } being considered, such as that of a fluid flow. back jamb See backlining. { bak jam } [MECH ENG] Resistance transferred from rock backjoint [CIV ENG] In masonry, a rabbet such into the drill stem when the bit is being fed at as that made on the inner side of a chimneypiece a faster rate than the bit can cut. { bak to receive a slip. { bakjȯint } preshər } backlash [DES ENG] The amount by which the back-pressure-relief port [ENG] In a plastics tooth space of a gear exceeds the tooth thickness extrusion die, an opening for the release of ex- of the mating gear along the pitch circles. cess material. { bak preshər rilēf pȯrt } [ELECTR] A small reverse current in a rectifier back rake [DES ENG] An angle on a single-point tube caused by the motion of positive ions pro- turning tool measured between the plane of the duced in the gas by the impact of thermoelec- tool face and the reference plane. { bak rāk } trons. [ENG] 1. Relativemotion ofmechanical back-run process [CHEM ENG] A process for parts caused by looseness. 2. The difference manufacturing water gas in which part of the run between the actual values of a quantity when a is made down, by passing steam through the dial controlling this quantity is brought to a superheater, thence up through the carburetor, given position by a clockwise rotation and when down through the generator, and direct to the it is brought to the same position by a counter- scrubbers. { bak rən präsəs } clockwise rotation. { baklash } backsaw [DES ENG] A fine-tooth saw with its backlining [BUILD] 1. A thin strip which lines a upper edge stiffened by a metal rib to ensure window casing, next to the wall and opposite straight cuts. { baksȯ } the pulley stile, and provides a smooth surface backscatter gage [ENG] A radar instrument for the working of the weighted sash. Also used to measure the radiation scattered at 180 known as back boxing; back jamb. 2. That piece to the direction of the incident wave. { bak of framing forming the back recess for boxing ¦skadər gaj } shutters. { baklı̄niŋ } backscattering thickness gage [ENG] A device back lintel [BUILD] A lintel which supports the that uses a radioactive source for measuring the backing of a masonry wall, as opposed to the thickness of materials, such as coatings, in which lintel supporting the facing material. { bak the source and the instrument measuring the radiation are mounted on the same side of thelintəl } 44 bag trap material, the backscattered radiation thus being (sewer) side of a trap to protect the trap against siphonage. { bak vent }measured. { bak¦skadəriŋ thiknəs gāj } backward-bladed aerodynamic fan [MECHbackset [BUILD] The horizontal distance from ENG] A fan that consists of several streamlinedthe face of a lock or latch to the center of the blades mounted in a revolving casing. { bakkeyhole, knob, or lock cylinder. { bakset } wərd blādəd erōdı̄namik fan }backsight [ENG] 1. A sight on a previously es- backward pass [IND ENG] The calculation oftablished survey point or line. 2. Reading a lev- late finish times (dates) for all uncompleted net-eling rod in its unchanged position after moving work activities for a specific project by sub-the leveling instrument to a different location. tracting durations of uncompleted activities{ baksı̄t } from the scheduled finish time of the final activ-backsight method [ENG] 1. A plane-table trav- ity. { bakwərd pas }ersing method in which the table orientation backwash [CHEM ENG] 1. In an ion-exchangeproduces the alignment of the alidade on an resin system, an upward flow of water throughestablished map line, the table being rotated a resin bed that cleans and reclassifies the resinuntil the line of sight is coincident with the cor- particles after exhaustion. 2. See blowback.responding ground line. 2. Sighting two pieces { bakwäsh }of equipment directly at each other in order to backwater valve [ENG] A type of check valve inorient and synchronize one with the other in a drainage pipe; reversal of flow causes the valveazimuth and elevation. { baksı̄t methəd } to close, thereby cutting off flow. Also knownback siphonage [CIV ENG] The flowing back of as backflow valve. { bakwȯdər valv }used, contaminated, or polluted water from a badger [DES ENG] See badger plane. [ENG]plumbing fixture or vessel into the pipe which A tool used inside a pipe or culvert to removefeeds it; caused by reduced pressure in the pipe. any excess mortar or deposits. { bajər }{ bak ¦sı̄fənij } badger plane [DES ENG] A hand plane whoseback solution [CONT SYS] The calculation of the mouth is cut obliquely from side to side, so that tool-coordinated positions that correspond to the plane can work close up to a corner. Also specified robotic joint positions. { bak səlü known as badger. { bajər plān } shən } baffle [ELEC] Device for deflecting oil or gas in a backspace [MECH ENG] To move a typewriter circuit breaker. [ELECTR] An auxiliary member carriage back one space by depressing a back- in a gas tube used, for example, to control the space key. { bakspās } flow of mercury particles or deionize the mercury backstay [ENG] 1. A supporting cable that pre- following conduction. [ENG] A plate that reg- vents a more or less vertical object from falling ulates the flow of a fluid, as in a steam-boiler forward. 2. A spring used to keep together the flue or a gasolinemuffler. [ENGACOUS] A cab- cutting edges of purchase shears. 3. A rod that inet or partition used with a loudspeaker to re- runs from either end of a carriage’s rear axle to duce interaction between sound waves produced the reach. 4. A leather strip that covers and simultaneously by the two surfaces of the dia- strengthens a shoe’s back seam. { bakstā } phragm. { bafəl } back sweetening [CHEM ENG] The controlled bag [ENG] 1. A flexible cover used in bag mold- addition of commercial-grade mercaptans to a ing. 2. A container made of paper, plastic, or petroleum stock having excess free sulfur in or- cloth without rigid walls to transport or store der to reduce free sulfur by forming a disulfide. material. { bag } { bak swētəniŋ } bag filter [ENG] Filtering apparatus with porous backup [BUILD] That part of a masonry wall be- cloth or felt bags throughwhich dust-laden gases hind the exterior facing. [CIV ENG] Overflow are sent, leaving the dust on the inner surfaces in a drain or piping system, due to stoppage. of the bags. { bag filtər } [ENG] 1. An item under development intended baghouse [ENG] The large chamber or room for to perform the same general functions that an- holding bag filters used to filter gas streams from other item also under development performs. a furnace. { baghau̇s } 2.A compressiblematerial used behind a sealant bag molding [ENG] A method of molding plas- to reduce its depth and to support the sealant tic or plywood-plastic combinations into curved against sag or indentation. { bakəp } shapes, in which fluid pressure acting through backupstrip [BUILD] Awood strip which is fixed a flexible cover, or bag, presses the material to at the corner of a partition or wall to provide a be molded against a rigid die. { bag mōldiŋ } nailing surface for ends of lath. Also known as Bagnold number [ENG] A dimensionless num- lathing board. { bakəp strip } ber used in saltation studies. { bagnəld backup system [SYS ENG] A system, normally nəmbər } redundant but kept available to replace a system bag plug [ENG] An inflatable drain stopper, which may fail in operation. { bakəp sistəm } located at the lowest point of a piping system, backup tong [ENG] A heavy device used on a that acts to seal a pipe when inflated. { bag drill pipe to loosen the tool joints. { bakəp pləg } täng } bag trap [ENG] An S-shaped trap in which the back vent [CIV ENG] An individual vent for a vertical inlet and outlet pipes are in alignment. { bag trap }plumbing fixture located on the downstream 45 ball grinder pointer adjacent to a calibrated scale in order ballistic measurement [MECH] Any measure- ment in which an impulse is applied to a deviceto measure the level of a liquid in a tank or other container. { bȯl flōt ¦likwəd ¦levəl mēdər } such as the bob of a ballistic pendulum, or the moving part of a ballistic galvanometer, and theball grinder See ball mill. { bȯl grindər } ballhead [MECH ENG] That part of the governor subsequent motion of the device is used to de- termine the magnitude of the impulse, and, fromwhich contains flyweights whose force is bal- anced, at least in part, by the force of compres- this magnitude, the quantity to be measured. { bəlistik mezhərmənt }sion of a speeder spring. { bȯlhed } Balling hydrometer [ENG] A type of saccharom- ballistic pendulum [ENG] A device which uses the deflection of a suspended weight to deter-eter used to determine the density of sugar solu- tions. { bȯliŋ hı̄drämədər } mine the momentum of a projectile. { bəlis tik penjələm }ballistic body [ENG] A body free to move, be- have, and be modified in appearance, contour, ballistics [MECH] Branch of applied mechanics which deals with the motion and behavior char-or texture by ambient conditions, substances, or forces, such as by the pressure of gases in a gun, acteristics of missiles, that is, projectiles, bombs, rockets, guided missiles, and so forth,by rifling in a barrel, by gravity, by temperature, or by air particles. { bəlistik bädē } and of accompanying phenomena. { bəlis tiks }ballistic coefficient [MECH] The numerical measure of the ability of a missile to overcome ballistic separator [CIV ENG] A device that takes out noncompostable material like stones, glass,air resistance; dependent upon the mass, diame- ter, and form factor. { bəlistik kōəfishənt } metal, and rubber, from solid waste by passing the waste over a rotor that has impellers to flingballistic conditions [MECH] Conditions which affect the motion of a projectile in the bore and the material in the air; the lighter organic (com- postable) material travels a shorter distancethrough the atmosphere, includingmuzzle veloc- ity, weight of projectile, size and shape of projec- than the heavier (noncompostable) material. { bəlistik sepərādər }tile, rotation of the earth, density of the air, tem- perature or elasticity of the air, and the wind. ballistics of penetration [MECH] That part of terminal ballistics which treats of the motion of{ bəlistik kəndishəns } ballistic curve [MECH] The curve described by a projectile as it forces its way into targets of solid or semisolid substances, such as earth,the path of a bullet, a bomb, or other projectile as determined by the ballistic conditions, by the concrete, or steel. { bəlistiks əv penətrā shən }propulsive force, and by gravity. { bəlistik kərv } ballistic table [MECH] Compilation of ballistic data from which trajectory elements such asballistic deflection [MECH] The deflection of a missile due to its ballistic characteristics. angle of fall, range to summit, time of flight, and ordinate at any time, can be obtained. { bəlis{ bəlistik diflekshən } ballistic density [MECH] A representation of tik tābəl } ballistic temperature [MECH] That temperaturethe atmospheric density encountered by a pro- jectile in flight, expressed as a percentage of (in F) which, when regarded as a surface temper- ature and used in conjunction with the lapsethe density according to the standard artillery atmosphere. { bəlistik densədē } rate of the standard artillery atmosphere, would produce the same effect on a projectile as theballistic efficiency [MECH] 1. The ability of a projectile to overcome the resistance of the air; actual temperature distribution encountered by the projectile in flight. { bəlistik temprədepends chiefly on the weight, diameter, and shape of the projectile. 2. The external effi- chər } ballistic trajectory [MECH] The trajectory fol-ciency of a rocket or other jet engine of a missile. { bəlistik ifishənsē } lowed by a body being acted upon only by gravi- tational forces and resistance of the mediumballistic entry [MECH] Movement of a ballistic body from without to within a planetary atmos- through which it passes. { bəlistik trəjektə rē }phere. { bəlistik entrē } ballistic instrument [ENG] Any instrument, ballistic uniformity [MECH] The capability of a propellant, when fired under identical conditionssuch as a ballistic galvanometer or a ballistic pendulum, that measures an impact or sudden from round to round, to impart uniform muzzle velocity and produce similar interior ballisticpulse of energy. { bəlistik instrəmənt } ballistic limit [MECH] The minimum velocity at results. { bəlistik yünəfȯrmədē } ballistic vehicle [ENG] A nonlifting vehicle; awhich a particular armor-piercing projectile is expected to consistently and completely pene- vehicle that follows a ballistic trajectory. { bəlistik vēəkəl }trate armor plate of given thickness and physical properties at a specified angle of obliquity. ballistic wave [MECH] An audible disturbance caused by compression of air ahead of a missile{ bəlistik limət } ballistic magnetometer [ENG] A magnetometer in flight. { bəlistik wāv } ballistic wind [MECH] That constant wind whichdesigned to employ the transient voltage in- duced in a coil when either the magnetized sam- would produce the same effect upon the trajec- tory of a projectile as the actual wind encoun-ple or coil are moved relative to each other. { bəlistik magnətämədər } tered in flight. { bəlistik wind } 48 band wheel ball mill [MECH ENG] A pulverizer that consists frictional force is applied by increasing the ten- of a horizontal rotating cylinder, up to three di- sion in a flexible band to tighten it around the ameters in length, containing a charge of tum- drum. { band brāk } bling or cascading steel balls, pebbles, or rods. band chain [ENG] A steel or Invar tape, gradua- Also known as ball grinder. { bȯl mil } ted in feet and at least 100 feet (30.5 meters) balloon framing [CIV ENG] Framing for a build- long, used for accurate surveying. { band ing in which each stud is one piece from roof to chān } foundation. { bəlün framiŋ } band clamp [DES ENG] A two-piece metal balloting [MECH] A tossing or bounding move- clamp, secured by bolts at both ends; used to ment of a projectile, within the limits of the bore hold riser pipes. { band klamp } diameter, while moving through the bore under band clutch [MECH ENG] A friction clutch inthe influence of the propellant gases. { bal which a steel band, lined with fabric, contractsədiŋ } onto the clutch rim. { band kləch }ball-peen hammer [ENG] A hammer with a ball band course See band. { band kȯrs }at one end of the head; used in riveting and banding [DES ENG] A strip of fabric which isforming metal. { bȯlpēn hamər } used for bands. hydIn a glacier, a structure ofball pendulum test [ENG] A test for measuring alternate ice layers of different textures andthe strength of explosives; consists of measuring appearance. { bandiŋ }the swing of a pendulum produced by the explo- band molding See band. { band mōldiŋ }sion of a weighed charge of material. { bȯl penjələm test } band-pass [ELECTR] A range, in hertz or kilo- ball race [DES ENG] A track, channel, or groove hertz, expressing the difference between the lim- in which ball bearings turn. { bȯl rās } iting frequencies at which a desired fraction ball screw [MECH ENG] An element used to (usually half power) of the maximum output is convert rotation to longitudinal motion, con- obtained. { band pas } sisting of a threaded rod linked to a threaded band-pass amplifier [ELECTR] An amplifier de- nut by ball bearings constrained to roll in the signed to pass a definite band of frequencies space formed by the threads, in order to reduce with essentially uniform response. { band pas friction. { bȯl skrü } ¦ampləfı̄ər } ball test [CIV ENG] In a drain, a test for freedom band-pass filter [ELECTR] An electric filter from obstruction and for circularity in which a which transmits more or less uniformly in a cer- ball (less than the diameter of the drain by a tain band, outside of which the frequency com- specified amount) is rolled through the drain. ponents are attenuated. { band pas filtər } { bȯl test } band-pass response [ELECTR] Response char-ball-up [ENG] 1. During a drilling operation, acteristics in which a definite band of frequen-collection by a portion of the drilling equipment cies is transmitted uniformly. Also known asof a mass of viscous consolidated material. flat top response. { band pas rispäns }2. Failure of an anchor to hold on a soft bottom, band-pass system [ENG ACOUS] A loudspeakerby pulling out with a large ball of mud attached. system, often used for subwoofers, in which the{ bȯl əp } speaker is mounted inside an enclosure on aball valve [MECHENG] A valve in which the fluid shelf that divides the enclosure into two parts,flow is regulated by a ball moving relative to a and one or both parts are coupled to the outsidespherical socket as a result of fluid pressure and by a vent; the frequency response of the systemthe weight of the ball. { bȯl valv } baluster [BUILD] A post which supports a hand- is that of a fourth-order band-pass filter (one rail and encloses the open sections of a stairway. vent) or an asymmetrical sixth-order band-pass { baləstər } filter (two vents). { bandpas sistəm } balustrade [BUILD] The railing assembly of a band-rejection filter See band-stop filter. { band stairway consisting of the handrail, balusters, rijekshən filtər } and usually a bottom rail. { baləstrād } band saw [MECH ENG] A power-operated band [BUILD] Any horizontal flat member or woodworking saw consisting basically of a flexi- molding or group of moldings projecting slightly ble band of steel having teeth on one edge, run- from a wall plane and usually marking a division ning over two vertical pulleys, and operated in the wall. Also known as band course; band under tension. { band sȯ } molding. [DES ENG] A strip or cord crossing band selector [ELECTR] A switch that selectsthe back of a book to which the sections are any of the bands in which a receiver, signal gener-sewn. { band } ator, or transmitter is designed to operate andbandage [BUILD] A strap, band, ring, or chain usually has two or more sections to make theplaced around a structure to secure and hold its required changes in all tuning circuits simultane-parts together, as around the springing of a ously. Also known as band switch. { banddome. [ELEC] Rubber ribbon about 4 inches səlektər }(10 centimeters) wide for temporarily protecting bandwheel [MECH ENG] In a drilling operation,a telephone or coaxial splice from moisture. a large wheel that transmits power from the en-{ bandij } band brake [MECH ENG] A brake in which the gine to the walking beam. { band wēl } 49 bang-bang control bang-bang control [CONT SYS] A type of auto- barefaced tenon [ENG] A tenon having a shoul- der cut on one side only. { berfāst ¦tenən }matic control system in which the applied con- bare tube [ENG] In a heat exchanger, a tubetrol signals assume either their maximum or whose inner and outer surfaces are both smooth.minimum values. { ¦baŋ ¦baŋ kəntrōl } { ¦ber tüb }bang-bang-off control See bang-zero-bang control. bargeboard See vergeboard. { bärjbȯrd }{ ¦baŋ ¦baŋ ȯf kəntrōl } barge couple [BUILD] 1. One of two rafters thatbang-bang robot [CONT SYS] A simple robot support that part of a gable roof which projectsthat canmake only two types of motions. { ¦baŋ beyond the gable wall. 2. One of the rafters¦baŋ rōbät } (under the barge course) which serve as groundsbang-zero-bang control [CONT SYS] A type of for the vergeboards and carry the plastering orcontrol in which the control values are at their boarding of the soffits. Also known as bargemaximum, zero, or minimum. Also known as rafter. { bärj kəpəl }bang-bang-off control. { ¦baŋ zirō baŋ barge course [BUILD] 1. The coping of a wall,kəntrōl } formed by a course of bricks set on edge. 2. Inbanister [BUILD] A handrail for a staircase. a tiled roof, the part of the tiling which projects{ banəstər } beyond the principal rafters where there is abank [CIV ENG] See embankment. [ELEC] 1. gable. { bärj kȯrs }A number of similar electrical devices, such as barge rafter See barge couple. { bärj raftər }resistors, connected together for use as a single barge spike See boat spike. { bärj spı̄k }device. 2. An assemblage of fixed contacts over barge stone [BUILD] One of the stones, gener-which one or more wipers or brushes move in ally projecting, which form the sloping top of aorder to establish electrical connections in auto- gable built of masonry. { bärj stōn }matic switching. [ENG] A pipework installa- bar hole [ENG] A small-diameter hole made intion in which the pipes are set parallel to each the ground along the route of a gas pipe in a other in proximity. [IND ENG] The amount of bar test survey. { bär hōl } material allowed to accumulate at a point on a Bari-Sol process [CHEM ENG] Removal of production line where it is not employed or waxes from liquid hydrocarbons by extraction worked upon, to permit reasonable fluctuations of the wax with a mixed ethylene dichloride- in line speed before and after the point. Also benzene solvent, followed by separation from known as float. { baŋk } the hydrocarbon in a centrifuge. { ¦bärē ¦säl banker [ENG] The bench or table upon which präsəs } bricklayers and stonemasons prepare and shape bar joist [BUILD] A small steel truss with wire or their material. { baŋkər } rod web lacing used for roof and floor supports. bank material [CIV ENG] Soil or rock in place { bär jȯist } before excavation or blasting. { baŋk mətir barker [DES ENG] See bark spud. [ENG] A ēəl } machine, used mainly in pulp mills, which re- bank measure [CIV ENG] The volume of a given moves the bark from logs. { bärkər } portion of soil or rock as measured in its original barkometer [CHEM ENG] A hydrometer cali- position before excavation. { baŋk mezhər } brated to test the strength of tanning liquors bar [MECH] A unit of pressure equal to 105 pas- used in tanning leather. { bärkämədər } cals, or 105 newtons per square meter, or 106 bark spud [DES ENG] A tool which peels off dynes per square centimeter. { bär } bark. Also known as barker. { bark spəd } Bárány chair [ENG] A chair in which a person bar linkage [MECH ENG] A set of bars joined is revolved to test his susceptibility to vertigo. together at pivots by means of pins or equivalent { bəränē cher } devices; used to transmit power and information. barb bolt [DES ENG] A bolt having jagged edges { bär liŋkij } to prevent its being withdrawn from the object Barlow’s equation [MECH] A formula, t into which it is driven. Also known as rag bolt. DP/2S, used in computing the strength of cylin- { bärb bōlt } ders subject to internal pressures, where t is the bar bending [CIV ENG] In reinforced concrete thickness of the cylinder in inches, D the outside construction, the process of bending reinforcing diameter in inches, P the pressure in pounds per bars to various shapes. { bär bendiŋ } square inch, and S the allowable tensile strength bar chair See bar support. { bär cher } in pounds per square inch. { bärlōz ikwā bar clamp [DES ENG] A clamping device con- zhən } sisting of a long bar with adjustable clamping barnacle [ENG] A nodelike deposit that occurs jaws; used in carpentry. { bär klamp } on the surface of a heat exchanger tube or an bare board [ELECTR] A printed circuit board evaporating device and has a semigranular outer with conductors but no electronic components. shell bonded to the fouled surface, enclosing a { ¦ber bȯrd } slurry of putrefying organisms. { bärnəkəl } bareboat charter [IND ENG] An agreement to barodynamics [MECH] The mechanics of heavy charter a ship without its crew or stores; the fee structures which may collapse under their own for its use for a predetermined period of time is weight. { barədı̄namiks } based on the price per ton of cargo handled. barogram [ENG] The record of an aneroid baro- graph. { barəgram }{ berbōt chärdər } 50 basic element base anchor [BUILD] The metal piece attached energy-absorbing materials. { bās ı̄sə¦lād to the base of a doorframe for the purpose of ərz } securing the frame to the floor. { bās aŋkər } base line Abbreviated BL. [ELECTR] The line base apparatus [ENG] Any apparatus designed traced on amplitude-modulated indicators for use in measuring with accuracy and precision which corresponds to the power level of the the length of a base line in triangulation, or the weakest echo detected by the radar; it is retraced length of a line in first- or second-order traverse. with every pulse transmitted by the radar but { bās apəradəs } appears as a nearly continuous display on the base bias [ELECTR] The direct voltage that is scope. [ENG] 1. A surveyed line, established applied to the majority-carrier contact (base) of with more than usual care, to which surveys are a transistor. { bās bı̄əs } referred for coordination and correlation. 2. A base block [BUILD] 1. A block of any material, cardinal line extending east and west along the generally with little or no ornament, forming the astronomic parallel passing through the initial lowest member of a base, or itself fulfilling the point, along which standard township, section, functions of a base, as a member applied to the and quarter-section corners are established. foot of a door or to window trim. 2. A rectangu- { bās lı̄n } lar block at the base of a casing or column which base-line check See ground check. { bās lı̄n the baseboard abuts. 3. See skirting block. chek } { bās bläk } basement [BUILD] A building story which is baseboard [BUILD] A finish board covering wholly or less than half below ground; it is gener- the interior wall at the junction of the wall and ally used for living space. { bāsmənt } the floor. Also known as skirt; skirting. basement wall [BUILD] A foundation wall which { bāsbȯrd } encloses a usable area under a building. { bās baseboard heater [BUILD] Heating elements mənt wȯl } installed in panels along the baseboard of a wall. basemolding [BUILD] Molding used to trim the { bāsbȯrd hēdər } upper edge of interior baseboard. Also knownbaseboard radiator [CIV ENG] A heating unit as base cap. { bās mōldiŋ } which is located at the lower portion of a wall base net [ENG] A system, in surveying, of quad-and to which heat is supplied by hot water, warm rilaterals and triangles that include and are quiteair, steam, or electricity. { bāsbȯrd rādē close to a base line in a triangulation system.ādər } { bās ¦net }base cap See base molding. { bās kap } base pin See pin. { bās pin }base circle [DES ENG] The circle on a gear such base plate [DES ENG] The part of a theodolitethat each tooth-profile curve is an involute of it. which carries the lower ends of the three foot{ bās sərkəl } screws and attaches the theodolite to the tripodbase correction [ENG] The adjustmentmade to for surveying. [ENG] A metal plate that pro-reduce measurements taken in field exploration vides support or a foundation. { bās plāt }to express them with reference to the base sta- base pressure [MECH] A pressure used as a ref-tion values. { bās kərekshən } erence base, for example, atmospheric pressure.base course [BUILD] The lowest course or first { bās ¦preshər }course of a wall. [CIV ENG] The first layer of base screed [ENG] A metal screed with ex-material laid down in construction of a pave- panded or short perforated flanges that servesment. { bās kȯrs } as a dividing strip between plaster and cementbase elbow [DES ENG] A cast-iron pipe elbow and acts as a guide to indicate proper thicknesshaving a baseplate or flange which is cast on it of cement or plaster. { bās skrēd }and by which it is supported. { bās ¦elbō } base sheet [BUILD] Saturated or coated feltbase electrode [ELECTR] An ohmic or majority sheeting which is laid as the first ply in a built-carrier contact to the base region of a transistor. up roofing membrane. { bās shēt }{ bās ilektrōd } base shoe [BUILD] A molding at the base of abase flashing [BUILD] 1. The flashing provided baseboard. { bās shü }by upturned edges of a watertight membrane on base shoe corner [BUILD] A molding piece ora roof. 2. Any metal or composition flashing at block applied in the corner of a room to eliminatethe joint between a roofing surface and a vertical the need for mitering the base shoe. { bās ¦shüsurface, such as a wall or parapet. { bās kȯrnər }flashiŋ } base station [ENG] The point from which a sur-base isolators [CIV ENG] Components placed vey begins. { bās stāshən }within a building (not always at the base) which base tee [DES ENG] A pipe tee with a connectedare relatively flexible in the lateral direction, yet baseplate for supporting it. { bās tē }can sustain the vertical load. When an earth- base tile [BUILD] The lowest course of tiles inquake causes ground motions, base isolators a tiled wall. { bās tı̄l }allow the structure to respondmuchmore slowly base time See normal element time; normal time.than it would without them, resulting in lower { bās tı̄m }seismic demand on the structure. Isolators may basic element See elementalmotion. { bāsik elbe laminated steel with high-quality rubber pads, sometimes incorporating lead or other əmənt } 53 basic feasible solution basic feasible solution [IND ENG] A basic solu- bastard thread [DES ENG] A screw thread that tion to a linear program model in which all the does not match any standard threads. { bas variables are nonnegative. { bāsik ¦fēzəbəl tərd thred } səlüshən } bastard tuckpointing [BUILD] An imitation tuck basic grasp [IND ENG] Any one of the funda- pointing in which the external face is parallel to mental means of taking hold of an object. { bā the wall, but projects slightly and casts a shadow. sik ¦grasp } Also known as bastard pointing. { bastərd ¦tək basic motion [IND ENG] A single, complete pȯintiŋ } movement of a body member; determined by bat bolt [DES ENG] A bolt whose butt or tang motion studies. { bāsik mōshən } is bashed or jagged. { bat bōlt } basic motion-time study [IND ENG] A system of batch [ENG] 1. The quantity of material re- predetermined motion-time standards for basic quired for or produced by one operation. motions. Abbreviated BMT study. { bāsik 2. An amount of material subjected to some unit mōshən tı̄m stədē } chemical process or physical mixing process to basic solution [IND ENG] A solution to a linear make the final product substantially uniform. program model, consisting of m equations in n { bach } variables, obtained by solving for m variables in batch box [ENG] A container of known volume terms of the remaining (n m) variables and used to measure and mix the constituents of a setting the (n m) variables equal to zero. batch of concrete, plaster, or mortar, to ensure { bāsik səlüshən } proper proportions. { bach bäks } basic truss [MECH] A framework of bars ar- batch distillation [CHEM ENG] Distillation ranged so that for any given loading of the bars where the entire batch of liquid feed is placed the forces on the bars are uniquely determined into the still at the beginning of the operation, by the laws of statics. { ¦bāsik trəs } in contrast to continuous distillation, where liq- basin [CIV ENG] 1. A dock employing floodgates uid is fed continuously into the still. { bach to keep water level constant during tidal varia- distəlāshən } tions. 2. A harbor for small craft. [DES ENG] batched water [ENG] The mixing water added An open-top vessel with relatively low sloping to a concrete or mortar mixture before or duringsides for holding liquids. { bāsən } the initial stages of mixing. { bacht wȯdər }basket [DES ENG] A lightweight container with batcher [MECH ENG] A machine in which theperforations. [MECH ENG] A type of single- ingredients of concrete are measured and com-tube core barrel made from thin-wall tubing with bined into batches before being discharged tothe lower end notched into points, which is in- the concrete mixer. { bachər }tended to pick up a sample of granular or plastic batching [ENG] Weighing or measuring the vol-rock material by bending in on striking the bot- ume of the ingredients of a batch of concrete ortom of the borehole or solid layer; may be used mortar, and then introducing these ingredientsto recover an article dropped into a borehole. into a mixer. { bachiŋ }Also known as basket barrel; basket tube; saw- batch manufacturing [IND ENG] The manufac-tooth barrel. { baskət } ture of parts in discrete runs or lots, generallybasket strainer [CHEM ENG] A porous-sided or interspersed with other production procedures.screen-covered vessel used to screen solid parti- { bach manəfakchəriŋ }cles out of liquid or gas streams. { baskət batch mixer [MECH ENG] A machine whichstrānər } mixes concrete or mortar in batches, as opposedbasket sub [ENG] A fishing tool run above a bit to a continuous mixer. { bach miksər }or a mill to recover small nondrillable pieces of batch plant [ENG] An operating installation ofmetal or debris in the well. { baskət səb } equipment including batchers and mixers as re-basket-weave [BUILD] A checkerboard pattern quired for batching or for batching and mixingof bricks, flat or on edge. { baskət wēv } concrete materials. { bach plant }bass reflex baffle [ENG ACOUS] A loudspeaker batch process [ENG] A process that is not inbaffle having an opening of such size that bass continuous or mass production; operations arefrequencies from the rear of the loudspeaker carried out with discrete quantities of materialemerge to reinforce those radiated directly for- or a limited number of items. { bach präsəs }ward. { ¦bas rēfleks bafəl } batch production See series production. { bachbass trap [ENG ACOUS] Any device used in a prədəkshən }sound-recording studio to absorb sound at fre- batch reactor [CHEM ENG] A chemical reactorquencies less than about 100 hertz. { bās in which the reactants and catalyst are intro-trap } duced in the desired quantities and the vesselbassy [ENG ACOUS] Pertaining to sound repro- is then closed to the delivery of additional mate-duction that overemphasizes low-frequency rial. { bach rēaktər }notes. { bāsē } batch rectification [CHEM ENG] Batch distilla-bastard-cut file [DES ENG] A file that has tion in which the boiled-off vapor is re-con-coarser teeth than a rough-cut file. { bastərd densed into liquid form and refluxed back into¦kət fı̄l } the still to make contact with the rising vapors.bastard pointing See bastard tuck pointing. { bastərd pȯintiŋ } { bach rektəfəkāshən } 54 bayonet socket batch treatment [CHEM ENG] A corrosion con- batten plate [CIV ENG] A rectangular plate used to connect two parallel structural steel memberstrol procedure in which chemical corrosion in- hibitors are injected into the lines of a produc- by riveting or welding. { batən plāt } batten roll [BUILD] In metal roofing, a roll jointtion system. { bach trētmənt } batch-type furnace [MECH ENG] A furnace used formed over a triangular-shaped wood piece. Also known as conical roll. { batən rōl }for heat treatment of materials, with or without direct firing; loading and unloading operations batten seam [BUILD] A seam in metal roofing which is formed around a wood strip. { batare carried out through a single door or slot. { bach tı̄p fərnəs } ən sēm } batter [CIV ENG] A uniformly steep slope in abathometer [ENG] A mechanism which meas- ures depths in water. { bəthämədər } retaining wall or pier; inclination is expressed as 1 foot horizontally per vertical unit (in feet).bathtub curve [IND ENG] An equipment failure- rate curve with an initial sharply declining failure { badər } batter board [CIV ENG] Horizontal boardsrate, followed by a prolonged constant-average failure rate, after which the failure rate again nailed to corner posts located just outside the corners of a proposed building to assist in theincreases sharply. { bathtəb kərv } bathyclinograph [ENG] A mechanism which accurate layout of foundation and excavation lines. { badər bȯrd }measures vertical currents in the deep sea. { ¦bathə¦klı̄nəgraf } batter brace [CIV ENG] A diagonal brace which reinforces one end of a truss. Also known asbathyconductograph [ENG] A device to meas- ure the electrical conductivity of sea water at batter post. { badər brās } batter level [ENG] A device for measuring thevarious depths from a moving ship. { ¦bathə kəndəktəgraf } inclination of a slope. { badər levəl } batter pile [CIV ENG] A pile driven at an inclina-bathygram [ENG] A graph recording the meas- urements of sonic sounding instruments. tion to the vertical to provide resistance to hori- zontal forces. Also known as brace pile; spur{ bathəgram } bathymetry [ENG] The science of measuring pile. { badər pı̄l } batter post [CIV ENG] 1. A post at one side of aocean depths in order to determine the sea floor topography. { bəthimətrē } gateway or at a corner of a building for protection against vehicles. 2. See batter brace. { badbathythermogram [ENG] The record that is made by a bathythermograph. { ¦bathəthər ər pōst } batter stick [CIV ENG] A tapered board which isməgram } bathythermograph [ENG] A device for ob- hung vertically and used to test the batter of a wall surface. { badər stik }taining a record of temperature against depth (actually, pressure) in the ocean from a ship battery [CHEM ENG] A series of distillation col- umns or other processing equipment operatedunderway. Abbreviated BT. Also known as bathythermosphere. { ¦bathəthərməgraf } as a single unit. [ELEC] A direct-current volt- age source made up of one or more units thatbathythermosphere See bathythermograph. { ¦bathəthərməsfir } convert chemical, thermal, nuclear, or solar en- ergy into electrical energy. { badərē }bating [CHEM ENG] Cleaning of depilated leather hides by the action of tryptic enzymes. battery limits [CHEM ENG] An area in a refinery or chemical plant encompassing a processing{ bādiŋ } batted work [ENG] A hand-dressed stone sur- unit or battery of units along with their related utilities and services. { badərē liməts }face scored from top to bottom in narrow parallel strokes (usually 8–10 per inch or 20–25 per centi- batting tool [ENG] A mason’s chisel usually 3–41/2 inches (7.6–11.4 centimeters) wide, usedmeter) by use of a batting tool. { badəd wərk } batten [BUILD] 1. A sawed timber strip of spe- to dress stone to a striated surface. { badiŋ tül }cific dimension-usually 7 inches (18 centimeters) broad, less than 4 inches (10 centimeters) thick, bauxite treating [CHEM ENG] A catalytic petro- leum process in which a vaporized petroleumand more than 6 feet (1.8 meters) long-used for outside walls of houses, flooring, and such. fraction is passed through beds of bauxite; con- version of many different sulfur compounds, par-2. A strip of wood nailed across a door or other structuremade of parallel boards to strengthen it ticularly mercaptans into hydrogen sulfide, takes place. { bȯksı̄t trēdiŋ }and prevent warping. 3. See furring. { batən } batten door [BUILD] A wood door without stiles b axis [MECH ENG] The angle that specifies the rotation of a machine tool about the y axis.which is constructed of vertical boards held to- gether by horizontal battens on the back side. { bē aksəs } bay [ENG] A housing used for equipment.Also known as ledged door. { batən dȯr } battened column [CIV ENG] A column con- { bā } bayonet coupling [DES ENG] A coupling insisting of two longitudinal shafts, rigidly con- nected to each other by batten plates. { bat which two or more pins extend out from a plug and engage in grooves in the side of a socket.ənd käləm } battened wall [BUILD] A wall to which battens { ¦bāənet ¦kəpliŋ } bayonet socket [DES ENG] A socket, havinghave been affixed. Also known as strapped wall. { batənd wȯl } J-shaped slots on opposite sides, into which a 55 Bedaux plan the unit is placed horizontally. 2. The layer of vacuum, holding gases, or covering objects. Also known as bell glass. { bel jär }mortar on which a masonry unit is set. [MECH bell-jar testing [ENG] A leak testing method inENG] The part of a machine having precisely which a vessel is filled with tracer gas and placedmachined ways or bearing surfaces which sup- in a vacuum chamber; leaks are evidenced byport or align other machine parts. { bed } gas drawn into the vacuum chamber. { bel järBedaux plan [IND ENG] A wage incentive plan testiŋ }in which work is standardized into man-minute bell-joint clamp [ENG] A clamp applied to aunits called bedaux (B); 60 B per hour is 100% bell-and-spigot joint to prevent leakage. { belproductivity, and earnings are based on work jȯint klamp }units per length of time. { bədō plan } Bellman’s principle of optimality [INDENG] Thebedding [CIV ENG] 1. Mortar, putty, or other principle that an optimal sequence of decisionssubstance used to secure a firm and even bear- in a multistage decision process problem hasing, such as putty laid in the rabbet of a window the property that whatever the initial state andframe, or mortar used to lay bricks. 2. A base decisions are, the remaining decisionsmust con-which is prepared in soil or concrete for laying stitute an optimal policy with regard to the statemasonry or concrete. { bediŋ } resulting from the first decisions. { belmənzbedding course [CIV ENG] The first layer ofmor- prinsəpəl əv äptəmalədē }tar at the bottom of masonry. { bediŋ kȯrs } bell mouth [DES ENG] A flared mouth on a pipebedding dot [BUILD] A small spot of plaster opening or other orifice. [ENG] A defect whichbuilt out to the face of a finished wall or ceiling; occurs during metal drilling in which a twist drillserves as a screed for leveling and plumbing in produces a hole that is not a perfect circle.the application of plaster. { bediŋ dät } { bel mau̇th }bed joint [CIV ENG] 1. A horizontal layer of mor- bellows [ENG] 1. A mechanism that expandstar on which masonry units are laid. 2. One of and contracts, or has a rising and falling top, to the radial joints in an arch. { bed jȯint } suck in air through a valve and blow it outbed molding [BUILD] 1. The lowest member of through a tube. 2.Any of several types of enclo- a band of moldings. 2. Any molding under a sures which have accordionlike walls, allowing projection, such as between eaves and sidewalls. one to vary the volume. 3. See aneroid capsule. { bed mōldiŋ } { belōz } beehive oven [ENG] An arched oven that car- bellows expansion joint [DES ENG] In a run of bonizes coal into coke by using the heat of com- piping, a joint formed with a flexible metal bel- bustion of gases that are formed, and of a small lows which compress or stretch to compensate part of the coke that is formed, with no recovery for linear expansion or contraction of the run of of by-products. { bēhı̄v əvən } piping. { belōz ikspanshən jȯint } beetle See rammer. { bēdəl } bellows gage [ENG] A device for measuring behavioral dynamics [IND ENG] 1. The behav- pressure in which the pressure on a bellows, with ioral operating characteristics of individuals and the end plate attached to a spring, causes a groups in terms of how these people are condi- measurable movement of the plate. { belōz tioned by their working environments. 2. The gāj } interactions between individuals or groups in bellows gas meter [ENG] A device for measur- the workplace. { bihāvyərəl dı̄namiks } ing the total volume of a continuous gas flow Belfast truss [CIV ENG] A bowstring beam for stream in which the motion of two bellows, alter- large spans, having the upper member bent and nately filled with and exhausted of the gas, actu- the lower member horizontal; constructed en- ates a register. { belōz ¦gas mēdər } tirely of timber components. { belfast trəs } bellows seal [MECH ENG] A boiler seal in the bell [ENG] 1. A hollow metallic cylinder closed form of a bellows which prevents leakage of air at one end and flared at the other; it is used or gas. { belōz sēl } as a fixed-pitch musical instrument or signaling bell-type manometer [ENG] A differential pres- device and is set vibrating by a clapper or tongue sure gage in which one pressure input is fed into which strikes the lip. 2. See bell tap. { bel } an inverted cuplike container floating in liquid, bell-and-spigot joint [ENG] A pipe joint in and the other pressure input presses down upon which a pipe ending in a bell-like shape is joined the top of the container so that its level in the to a pipe ending in a spigotlike shape. { ¦bel liquid is the measure of differential pressure. ən spikət jȯint } { beltı̄p mənämədər } bell cap [CHEM ENG] A hemispherical or trian- belt [CIV ENG] In brickwork, a projecting row gular metal casting used on distillation-column (or rows) of bricks, or an inserted row made of a trays to force upflowing vapors to bubble different kind of brick. [MECH ENG] A flexible through layers of downcoming liquid. { bel band used to connect pulleys or to convey mate- kap } rials by transmitting motion and power. { belt } belled caisson [CIV ENG] A type of drilled cais- belt conveyor [MECH ENG] A heavy-duty con- son with a flared bottom. { beld kāsän } veyor consisting essentially of a head or drive bell glass See bell jar. { bel glas } pulley, a take-up pulley, a level or inclined end- bell jar [ENG] A bell-shaped vessel, usually less belt made of canvas, rubber, or metal, and carrying and return idlers. { belt kənvāər }made of glass, which is used for enclosing a 58 bending brake belt course See string course. { belt kȯrs } whose elevation above or below an adopted da- tum—for example, sea level—is known. Ab-belt drive [MECH ENG] The transmission of breviated BM. [IND ENG] A standard of meas-power between shafts by means of a belt con- urement possessing sufficient identifiable char-necting pulleys on the shafts. { belt drı̄v } acteristics common to the individual units of abelted-bias tire See bias-belted tire. { ¦beltəd bı̄ population to facilitate economical and efficientəs tı̄r } comparison of attributes for units selected frombelt feeder [MECH ENG] A short belt conveyor a sample. { benchmärk }used to transfer granulated or powdered solids benchmark index [IND ENG] In manufacturingfrom a storage or supply point to an end-use andmining, an index designed to reflect changespoint; for example, from a bin hopper to a chemi- in output occurring between census years.cal reactor. { belt fēdər } { benchmärk indeks }belt guard [MECH ENG] A cover designed to benchmark job [IND ENG] A job that can be re-protect a belt as well as the pulleys it connects. lated or compared to other jobs in terms of com-{ belt gärd } mon characteristics and considered an accept-belt highway See beltway. { ¦belt hı̄wā } able gauge for other jobs without the need ofbelt sander [MECH ENG] A portable sanding direct measurements. { benchmärk jäb } tool having a power-driven abrasive-coated con- bench photometer [ENG] A device which uses tinuous belt. { belt sandər } an optical bench with the two light sources to belt shifter [MECH ENG] A device with fingerlike be comparedmounted one at each end; the com- projections used to shift a belt from one pulley parison between the two illuminations is made to another or to replace a belt which has slipped by a device moved along the bench until match- off a pulley. { belt shiftər } ing brightnesses appear. { bench fətäm belt slip [MECH ENG] The difference in speed ədər } between the driving drum and belt conveyor. bench plane [DES ENG] A plane used primarily { belt slip } in benchwork on flat surfaces, such as a block belt tightener [MECH ENG] In a belt drive, a de- plane or jack plane. { bench plān } vice that takes up the slack in a belt that has bench sander [MECH ENG] A stationary power become stretched and permanently lengthened. sander, usually mounted on a table or stand, { belt tı̄tnər } which is equipped with a rotating abrasive disk beltway [CIV ENG] A highway that encircles an or belt. { bench sandər } urban area along its perimeter. Also known as bench-scale testing [ENG] Testing of materials, belt highway; ring road. { beltwā } methods, or chemical processes on a small scale, bench assembly [ENG] A technique of fitting such as on a laboratory worktable. { bench and joining parts using a bench as a work surface. skāl testiŋ } { bench əsemblē } bench stop [ENG] A bench hook which is used bench check [INDENG] Aworkshop or servicing to fasten work in place, often by means of a screw. { bench stäp }bay check which includes the typical check or bench table [BUILD] A projecting course of ma-actual functional test of an item to ascertain sonry at the foot of an interior wall or around awhat is to be done to return the item to a service- column; generally wide enough to form a seat.able condition or ascertain the item’s temporary { bench tābəl }or permanent disposition. { bench chek } bench vise [ENG] An ordinary vise fixed to abench dog [ENG] A wood or metal peg, placed workbench. { bench vı̄s }in a slot or hole at the end of a bench; used to benchwork [ENG] Any work performed at akeep a workpiece from slipping. { bench dȯg } workbench rather than on machines or in thebench hook [ENG] Any device used on a car- field. { benchwərk }penter’s bench to keep work frommoving toward bend [DES ENG] 1. The characteristic of an ob-the rear of the bench. Also known as side hook. ject, such as a machine part, that is curved.{ bench hu̇k } 2. A section of pipe that is curved. 3. A knotbenching [CIV ENG] 1. Concrete laid on the side formed by a rope fastened to an object or another slopes of drainage channels where the slopes rope. { bend } are interrupted by manholes, and so forth. bend allowance [DES ENG] Length of the arc of 2. Concrete laid on sloping sites as a safeguard the neutral axis between the tangent points of against sliding. 3.Concrete laid along the sides a bend in any material. { bend əlau̇əns } of a pipeline to provide additional support. bender See bending machine. { bendər } { benchiŋ } bending [ENG] 1. The forming of a metal part, bench lathe [MECH ENG] A small engine or by pressure, into a curved or angular shape, or toolroom lathe suitable for attachment to a the stretching or flanging of it along a curved workbench; bed length usually does not exceed path. 2. The forming of a wooden member to 6 feet (1.8 meters) and workpieces are generally a desired shape by pressure after it has been small. { bench lāth } softened or plasticized by heat and moisture. benchmark [ENG] A relatively permanent natu- { bendiŋ } bending brake [MECH ENG] A press brake forral or artificial object bearing a marked point 59 bending iron making sharply angular linear bends in sheet dewaxing process in which a mixture of the sol- vent and oil containing wax is cooled until themetal. { bendiŋ brāk } wax solidifies and is then removed by filtration.bending iron [ENG] A tool used to straighten { benzȯl asətōn präsəs }or to expand flexible pipe, especially lead pipe. Bergius process [CHEM ENG] Treatment of car-{ bendiŋ ı̄ərn } bonaceous matter, such as coal or cellulosicbending machine [MECH ENG] A machine for materials, with hydrogen at elevated pressuresbending a metal or wooden part by pressure. and temperatures in the presence of a catalyst,Also known as bender. { bendiŋ məshēn } to form an oil similar to crude petroleum. Alsobending moment [MECH] Algebraic sum of all known as coal hydrogenation. { bergēəsmoments located between a cross section and präsəs }one end of a structural member; a bending mo- Berl saddle [CHEMENG] A type of column pack-ment that bends the beam convex downward is ing used in distillation columns. { bərl sadpositive, and one that bends it convex upward əl }is negative. { bendiŋ mōmənt } berm [CIV ENG] A horizontal ledge cut betweenbending-moment diagram [MECH] A diagram the foot and top of an embankment to stabilizeshowing the bending moment at every point the slope by intercepting sliding earth. { bərm }along the length of a beam plotted as an ordi- Bernoulli-Euler law [MECH] A law stating thatnate. { bendiŋ ¦mōmənt dı̄əgram } the curvature of a beam is proportional to thebending schedule [CIV ENG] A chart showing bending moment. { bernülē ¦ȯilər ¦lȯ }the shapes and dimensions of every reinforcing Berthelot method [THERMO] A method of mea-bar and the number of bars required on a particu- suring the latent heat of vaporization of a liquidlar job for the construction of a reinforced con- that involves determining the temperature risecrete structure. { bendiŋ skejəl } of a water bath that encloses a tube in which abending stress [MECH] An internal tensile or given amount of vapor is condensed. { ber compressive longitudinal stress developed in a təlō methəd } beam in response to curvature induced by an Berthondynamometer [ENG] An instrument for external load. { bendiŋ stres } measuring the diameters of small objects, con- Bendix-Weiss universal joint [MECH ENG] A sisting of two metal straightedges inclined at a universal joint that provides for constant angular small angle and rigidly joined together; a scale velocity of the driven shaft by transmitting the on one of the straightedges is used to read the torque through a set of four balls lying in the diameters of objects inserted between them. plane that contains the bisector of, and is per- { bərthän dı̄nəmämədər } pendicular to, the plane of the angle between beryllium detector [ENG] An instrument de- the shafts. { ¦bendiks ¦wı̄s yünəvərsəl jȯint } signed to detect and analyze for beryllium by bend radius [DES ENG] The radius correspond- gamma-ray activation analysis. Also known as ing to the curvature of a bent specimen or part, berylometer. { bərilēəm ditektər } as measured at the inside surface of the bend. berylometer See beryllium detector. { berəläm { bend rādēəs } ədər } bend wheel [MECH ENG] A wheel used to inter- best commercial practice [ENG] A manufactur- rupt and change the normal path of travel of ing standard for a process vessel which has not the conveying or driving medium; most generally been designed according to standard codes, used to effect a change in direction of conveyor such as the American Society of Mechanical travel from inclined to horizontal or a similar Engineers Boiler Code. { best kəmərshəl change. { bend wēl } praktəs } Benioff extensometer [ENG] A linear strain- beta [ELECTR] The current gain of a transistor meter for measuring the change in distance be- that is connected as a grounded-emitter ampli- tween two reference points separated by 60–90 fier, expressed as the ratio of change in collector feet (20–30 meters) or more; used to observe current to resulting change in base current, the earth tides. { benēȯf ekstensämədər } collector voltage being constant. { bādə } bent [CIV ENG] A framework support transverse beta-cutoff frequency [ELECTR] The frequency to the length of a structure. { bent } at which the current amplification of an amplifier bent bar [CIV ENG] A longitudinal reinforcing transistor drops to 3 decibels below its value at bar which is bent to pass from one face of a 1 kilohertz. { bādə kədȯf frēkwənsē } structural member to the other face. { bent Bethell process See full-cell process. { bethəl bär } präsəs } bent-tube boiler [MECH ENG] A water-tube Betterton-Kroll process [CHEM ENG] A method steam boiler in which the tubes terminate in for obtaining pure bismuth from softened and upper and lower steam-and-water drums. Also desilverized lead. { ¦bedərtən ¦krōl präsəs } known as drum-type boiler. { bent tüb bȯil Betti reciprocal theorem [MECH] A theorem in ər } the mathematical theory of elasticity which bentwood [ENG] Wood formed to shape by states that if an elastic body is subjected to two bending, rather than by carving or machining. systems of surface and body forces, then the { bentwu̇d } work that would be done by the first system acting through the displacements resulting frombenzol-acetone process [CHEMENG] A solvent 60 blackbody radiation by the thermal diffusivity equals the Laplacian bistable circuit [ELECTR] A circuit with two sta- ble states such that the transition between theof the temperature. { ¦byō ¦füryā ikwāzhən } states cannot be accomplished by self-triggering.biotron [ENG] A test chamber used for biologi- { ¦bı̄¦stābəl sarkət }cal researchwithin which the environmental con- bistable unit [ENG] A physical element that canditions can be completely controlled, thus be made to assume either of two stable states; aallowing observations of the effect of variations binary cell is an example. { ¦bı̄¦stābəl yünət }in environment on living organisms. { bı̄ bistatic radar [ENG] Radar system in which theəträn } receiver is some distance from the transmitter,bipolar amplifier [ELECTR] An amplifier capa- with separate antennas for each. { bı̄stadikble of supplying a pair of output signals corres- rādär }ponding to the positive or negative polarity of bit [DES ENG] 1. A machine part for drilling orthe input signal. { bı̄pōlər ampləfı̄ər } boring. 2. The cutting plate of a plane. 3. Thebipolar circuit [ELECTR] A logic circuit in which blade of a cutting tool such as an ax. 4. A re-zeros and ones are treated in a symmetric or movable tooth of a saw. 5. Any cutting devicebipolar manner, rather than by the presence or which is attached to or part of a drill rod or drillabsence of a signal; for example, a balanced string to bore or penetrate rocks. { bit }arrangement in a square-loop-ferrite magnetic bit blank [DES ENG] A steel bit in which dia-circuit. { bı̄pōlər sərkət } monds or other cutting media may be inset bybipolar electrode [ELEC] Electrode, without hand peening or attached by a mechanical proc-metallic connection with the current supply, one ess such as casting, sintering, or brazing. Alsoface of which acts as anode surface and the oppo- known as bit shank; blank; blank bit; shank.site face as a cathode surface when an electric { bit blaŋk }current is passed through a cell. { bı̄pōlər bit breaker [DES ENG] A heavy plate that fits inilektrōd } a rotary table for holding the drill bit while it isbipolar integrated circuit [ELECTR] An inte- being inserted or broken out of the drill stem. grated circuit in which the principal element is { bit brākər } the bipolar junction transistor. { bı̄pōlər in bit cone See roller cone bit. { bit kōn } təgrādəd sərkət } bit drag [DES ENG] A rotary-drilling bit that has bipolar junction transistor [ELECTR] A bipolar serrated teeth. Also known as drag bit. transistor that is composed entirely of one type { bit drag } of semiconductor, silicon. Abbreviated BJT. bite [ENG] In glazing, the length of overlap of Also known as silicon homojunction. { ¦bı̄pōl the inner edge of a frame over the edge of theər jəŋkshən tranzistər } glass. { bı̄t } bipolar magnetic driving unit [ENG ACOUS] bit matrix [ENG] The material, usually pow- Headphone or loudspeaker unit having twomag- dered and fused tungsten carbide, into which netic poles acting directly on a flexible iron diamonds are set in the manufacture of diamond diaphragm. { bı̄pōlər magnedik driviŋ yü bits. { bit mātriks } nət } bitrochanteric width [IND ENG] Ameasurement bipolar spin device Seemagnetic switch. { ¦bı̄pō corresponding to hip breadth that is used in lər spin divı̄s } seating design. { bı̄trəkan¦terik width } bipolar spin switch Seemagnetic switch. { ¦bı̄pō bit shank See bit blank. { bit shaŋk } lər spin swich } bittern [CHEM ENG] Concentrated sea water or bipolar transistor [ELECTR] A transistor that brine containing the bromides and magnesium uses both positive and negative charge carriers. and calcium salts left in solution after sodium { bı̄pōlər tranzistər } chloride has been removed by crystallization. birdcaged wire [ENG] Wire rope whose strands { bidərn } have been distorted into the shape of a birdcage bituminous distributor [MECH ENG] A tank by a sudden release of a load during a hoisting truck having a perforated spray bar and used operation. { bərdkājd wı̄r } for pumping hot bituminous material onto the Birkeland-Eyde process [CHEM ENG] An arc surface of a road or driveway. { bı̄¦tümənəs process of nitrogen fixation in which air passes distribyədər } through an alternating-current arc flattened by bivane [ENG] A double-jointed vane which a magnetic field to form about 1% nitric oxide. measures vertical as well as horizontal wind di- { ¦bərklənd ¦ı̄də präsəs } rection. { bı̄vān } Birmingham wire gage [DES ENG] A system of blackbody [THERMO] An ideal body which standard sizes of brass wire, telegraph wire, steel would absorb all incident radiation and reflect tubing, seamless tubing, sheet spring steel, strip none. Also known as hohlraum; ideal radiator. steel, and steel plates, bands, and hoops. Ab- { blak¦bädē } breviated BWG. { bərmiŋəm wı̄r gāj } blackbody radiation [THERMO] The emission of birth-death process [IND ENG] A simple queu- radiant energy which would take place from a ing model in which units to be served arrive blackbody at a fixed temperature; it takes place (birth) and depart (death) in a completely ran- at a rate expressed by the Stefan-Boltzmann law, dom manner. { ¦bərth ¦deth präsəs } with a spectral energy distribution described by Planck’s equation. { blak¦bädē rādēāshən }biscuit See preform. { biskət } 63 blackbody temperature blackbody temperature [THERMO] The temper- of a double-action power press; it is usually oper- ated by toggles or cams. { blaŋkhōldər slı̄d }ature of a blackbody that emits the same amount blanking [ENG] 1. The closing off of flowof heat radiation per unit area as a given object; through a liquid-containing process pipe by themeasured by a total radiation pyrometer. Also insertion of solid disks at joints or unions; usedknown as brightness temperature. { blak¦bäd during maintenance and repair work as a safetyē temprəchər } precaution. Also known as blinding. 2. Cut-black box [ENG] Any component, usually elec- ting of plastic or metal sheets into shapes bytronic and having known input and output, that striking with a punch. Also known as die cut-can be readily inserted into or removed from a ting. { blaŋkiŋ }specific place in a larger system without knowl- blast [ENG] The setting off of a heavy explosiveedge of the component’s detailed internal struc- charge. { blast }ture. { blak bäks } blast burner [ENG] A burner in which a con-black-bulb thermometer [ENG] A thermometer trolled burst of air or oxygen under pressure iswhose sensitive element has been made to ap- supplied to the illuminating gas used. Alsoproximate a blackbody by covering it with lamp- known as blast lamp. { blast bərnər }black. { blak bəlb thərmämədər } blast cleaning [ENG] Any cleaning process inblack smoke [ENG] A smoke that hasmany par- which an abrasive is directed at high velocityticulates in it from inefficient combustion; comes toward the surface being cleaned, for example,from burning fossil fuel, either coal or oil. sand blasting. { blast klēniŋ }{ ¦blak smōk } blast ditching [CIV ENG] The use of explosivesblack-surface enclosure [THERMO] An enclo- to aid in ditch excavation, such as for layingsure for which the interior surfaces of the walls pipelines. { blast dichiŋ }possess the radiation characteristics of a black- blaster [ENG] A device for detonating an explo-body. { blak sərfəs inklozhər } sive charge; usually consists of a machine byblacktop paver [MECH ENG] A construction ve- which an operator, by pressing downward or oth- hicle that spreads a specified thickness of bitu- erwisemoving a handle of the device, may gener- minous mixture over a prepared surface. ate a powerful transient electric current which is { blaktäp pāvər } transmitted to an electric blasting cap. Also bladder press [MECHENG] Amachine which si- known as blasting machine. { blastər } multaneously molds and cures (vulcanizes) a blast freezer [ENG] An upright freezer in which pneumatic tire. { bladər pres } very cold air circulated by blowers is used for blade [ELEC] A flat moving conductor in a rapid freezing of food. { blast frēzər } switch. [ENG] 1. A broad, flat arm of a fan, blast heater [MECH ENG] A heater that has a turbine, or propeller. 2. The broad, flat surface set of heat-transfer coils through which air is of a bulldozer or snowplow by which the material forced by a fan operating at a relatively high is moved. 3. The part of a cutting tool, such as velocity. { blast hēdər } a saw, that cuts. { blād } blasthole [ENG] 1. A hole that takes a heavy bladed-surface aerator [CIV ENG] A bladed, ro- charge of explosive. 2. The hole through which tating component of a water treatment plant; water enters in the bottom of a pump stock. used to infuse air into the water. { bladəd sər { blasthōl } fəs erādər } blasthole drilling [ENG] Drilling to produce a Blake jaw crusher [MECH ENG] A crusher with series of holes for placement of blasting charges. one fixed jaw plate and one pivoted at the top so { blasthōl driliŋ } as to give the greatest movement on the smallest blasting [ENG] 1. Cleaning materials by a blast lump. { blāk jȯ krəshər } of air that blows small abrasive particles against blank [DES ENG] See bit blank. [ELECTR] To the surface. 2. The act of detonating an explo- cut off the electron beam of a television picture sive. { blastiŋ } tube, camera tube, or cathode-ray oscilloscope blasting cap [ENG] A copper shell closed at one tube during the process of retrace by applying a end and containing a charge of detonating com- rectangular pulse voltage to the grid or cathode pound, which is ignited by electric current or during each retrace interval. Also known as the spark of a fuse; used for detonating high beam blank. [ENG] 1. The result of the final explosives. { blastiŋ kap } cutting operation on a natural crystal. 2. See blasting fuse [ENG] A core of gunpowder in the blind. { blaŋk } center of jute, yarn, and so on for igniting an blank bit See bit blank. { blaŋk bit } explosive charge in a shothole. { blastiŋ blanket gas [CHEM ENG] A gas phase intro- fyüz } duced into a vessel above a liquid phase to pre- blasting machine See blaster. { blastiŋ vent contamination of the liquid, reduce hazard mashēn } of detonation, or to exert pressure on the liquid. blastingmat [ENG] A heavy, flexible, tear-resist- Also known as cushion gas. { blaŋkət gas } ant covering that is spread over the surface dur- blank flange [DES ENG] A solid disk used to ing blasting to contain earth fragments. close off or seal a companion flange. { blaŋk { blastiŋ mat } flanj } blast lamp See blast burner; blowtorch. { blast lamp }blankholder slide [MECH ENG] The outer slide 64 block and tackle blast wall [ENG] A heavy wall used to isolate an added component (for example, tetraethyl- lead, isooctane, and aromatics) to affect the oc-buildings or areas which contain highly combus- tane rating of a base gasoline stock. { blentible or explosive materials or to protect a build- diŋ valyü }ing or area from blast damage when exposed to blendstock See blending stock. { blendstäk }explosions. { blast wȯl } blend stop [BUILD] A thin wood strip fastenedBlears effect [ENG] The dependence of the sig- to the exterior vertical edge of the pulley stilenal from an ionization gage on the geometry or jamb to hold the sash in position. { blendof the system being measured when an organic stäp }vapor is present in the vacuum; the effect can blind [ENG] A solid disk inserted at a pipe jointfalsify measurement results by up to an order of or union to prevent the flow of fluids throughmagnitude. { blirz ifekt } the pipe; used during maintenance and repairbleed [ENG] To let a fluid, such as air or liquid work as a safety precaution. Also known asoxygen, escape under controlled conditions from blank. { blı̄nd }a pipe, tank, or the like through a valve or out- blind controller system [CONT SYS] A processlet. { blēd } control arrangement that separates the in-plantbleeder [ELECTR] A high resistance connected measuring points (for example, pressure, tem-across the dc output of a high-voltage power perature, and flow rate) and control points (forsupply which serves to discharge the filter capac- example, a valve actuator) from the recorder oritors after the power supply has been turned indicator at the central control panel. { ¦blı̄ndoff, and to provide a stabilizing load. [ENG] A kəntrōlər sistəm }connection located at a low place in an air line blind drilling [ENG] Drilling in which the drillingor a gasoline container so that, by means of a fluid is not returned to the surface. { blı̄ndsmall valve, the condensed water or other liquid driliŋ }can be drained or bled off from the line or con- blind flange [DES ENG] A flange used to closetainer without discharging the air or gas. the end of a pipe. { ¦blı̄nd flanj }{ blēdər } blind floor See subfloor. { ¦blı̄nd flȯr }bleeder turbine [MECH ENG] A multistage tur- blind hole [DES ENG] A hole which does notbine where steam is extracted (bled) at pressures pass completely through a workpiece. [ENG]intermediate between throttle and exhaust, for A type of borehole that does not have the drillingprocess or feedwater heating purposes. { blēd mud or other circulating medium carry the cut-ər tərbən } tings to the surface. { ¦blı̄nd hōl }bleeding [CHEM ENG] The undesirable move- blinding [ENG] 1. A thin layer of lean concrete, ment of certain components of a plastic material fine gravel, or sand that is applied to a surface to to the surface of a finished article. Also known smooth over voids in order to provide a cleaner, as migration. [ENG] Natural separation of a drier, or more durable finish. 2. A layer of small liquid from a liquid-solid or semisolid mixture; rock chips applied over the surface of a freshly for example, separation of oil from a stored lubri- tarred road. 3. See blanking. { blı̄ndiŋ } cating grease, or water from freshly poured con- blind joint [ENG] A joint which is not visible crete. Also known as bleedout. { blēdiŋ } from any angle. { ¦blı̄nd joint } bleeding cycle [MECH ENG] A steam cycle in blind nipple [MECH ENG] A short piece of pip- which steam is drawn from the turbine at one ing or tubing having one end closed off; com- or more stages and used to heat the feedwater. monly used in boiler construction. { ¦blı̄nd Also known as regenerative cycle. { blēdiŋ nipəl } sı̄kəl } blind spot [ENG] An area on a filter screen bleedout See bleeding. { blēdau̇t } where no filtering occurs. Also known as dead bleed valve [ENG] A small-flow valve connected area. { blı̄nd spät } to a fluid process vessel or line for the purpose of blink [MECH] A unit of time equal to 105 day bleeding off small quantities of contained fluid. or to 0.864 second. { bliŋk } { blēd valv } blister [ENG] A raised area on the surface of a blended data [ENG] Q point that is the combi- metallic or plastic object caused by the pressure nation of scan data and track data to form a of gases developed while the surface was in a vector. { ¦blendəd dadə } partly molten state, or by diffusion of high-pres- blending problem [IND ENG] A linear program- sure gases from an inner surface. { blistər } ming problem in which it is required to find the blistering [ENG] The appearance of enclosed or least costly mix of ingredients which yields the broken macroscopic cavities in a body or in a desired product characteristics. { blendiŋ glaze or other coating during firing. { blistə präbləm } riŋ } blending stock [CHEM ENG] Any substance block [DES ENG] 1. A metal or wood case en- used for compounding gasoline, including natu- closing one or more pulleys; has a hook with ral gasoline, catalytically reformed products, and which it can be attached to an object. 2. See additives. Also known as blendstock. { blen cylinder block. { bläk } diŋ stäk } block and fall See block and tackle. { ¦bläk ən fȯl } block and tackle [MECH ENG] Combination ofblending value [ENG] Measure of the ability of 65 body force during Poinsotmotion. Also known as polhode boiler economizer [MECH ENG] A component of a steam-generating unit that transfers heatcone. { bädē kōn } body force [MECH] An external force, such as from the products of combustion after they have passed through the steam-generating and super-gravity, which acts on all parts of a body. { bäd ē fȯrs } heating sections to the feedwater, which it re- ceives from the boiler feed pump and deliversbody-load aggregate [IND ENG] A biomechani- cal unit that comprises the combined weight of to the steam-generating section of the boiler. { bȯilər ikänəmizər }the load being manipulated and the body seg- ments involved in the task. { ¦bädē ¦lōd a boiler efficiency [MECH ENG] The ratio of heat absorbed in steam to the heat supplied in fuel,grəgət } body motion [IND ENG] Motion of parts of a usually measured in percent. { bȯilər ifish ənsē }human body requiring a change of posture or weight distribution. { bädē mōshən } boiler feedwater [MECH ENG] Water supplied to a steam-generating unit. { bȯilər fēdbody rotation [CONT SYS] An axis of motion of a pick-and-place robot. { bäde rōtāshən } wȯdər } boiler feedwater regulation [MECH ENG] Ad-bogie Also spelled bogey; bogy. [ENG] 1. A sup- porting and aligning wheel or roller on the inside dition of water to the steam-generating unit at a rate commensurate with the removal of steamof an endless track. 2. A low truck or cart of solid build. 3. A truck or axle to which wheels from the unit. { bȯilər fēdwȯdər regyəlā shən }are fixed, which supports a railroad car, the lead- ing end of a locomotive, or the end of a vehicle boiler furnace [MECH ENG] An enclosed space provided for the combustion of fuel to generate(such as a gun carriage) and which is allowed to swivel under it. 4. A railroad car or locomotive steam in a boiler. Also known as steam-gener- ating furnace. { bȯilər fərnəs }supported by a bogie. [MECH ENG] The drive- wheel assembly and supporting frame compris- boiler heat balance [MECH ENG] Ameans of ac- counting for the thermal energy entering aing the four rear wheels of a six-wheel truck, mounted so that they can self-adjust to sharp steam-generating system in terms of its ultimate useful heat absorption or thermal loss. { bȯilcurves and irregularities in the road. { bōgē } boiler [MECH ENG] A water heater for generat- ər hēt baləns } boiler horsepower [MECH ENG] A measure-ing steam. { bȯilər } boiler air heater [MECH ENG] A component of ment of water evaporation rate; 1 boiler horse- power equals the evaporation per hour of 341/2a steam-generating unit that transfers heat from the products of combustion after they have pounds (15.7 kilograms) of water at 212F (100C) into steam at 212F. Abbreviated bhp. { bȯilpassed through the steam-generating and super- heating sections to combustion air, which recy- ər hȯrspau̇ər } boiler hydrostatic test [MECH ENG] A proce-cles heat to the furnace. { bȯilər er hēdər } boiler casing [MECH ENG] The gas-tight struc- dure that employs water under pressure, in a new boiler before use or in old equipment afterture surrounding the component parts of a steam generator. { bȯilər kāsiŋ } major alterations and repairs, to test the boiler’s ability to withstand about 11/2 times the designboiler circulation [MECH ENG] Circulation of water and steam in a boiler, which is required pressure. { bȯilər hı̄drəstadik test } boiler layup [MECH ENG] A significant length ofto prevent overheating of the heat-absorbing surfaces; may be provided naturally by gravita- time during which a boiler is inoperative in order to allow for repairs or preventive maintenance.tional forces, mechanically by pumps, or by a combination of both methods. { bȯilər sər { bȯilər lāəp } boiler setting [MECH ENG] The supporting steelkyəlāshən } boiler cleaning [ENG] A mechanical or chemi- and gastight enclosure for a steam generator. { bȯilər sediŋ }cal process for removal of grease, scale, and other deposits from steam boiler surfaces. boiler storage [MECH ENG] A steam-generating unit that, when out of service, may be stored wet{ bȯilər klēniŋ } boiler code [MECH ENG] A code, established by (filled with water) or dry (filled with protective gas). { bȯilər stȯrij }professional societies and administrative units, which contains the basic rules for the safe de- boiler superheater [MECH ENG] A boiler com- ponent, consisting of tubular elements, in whichsign, construction, and materials for steam-gen- erating units, such as the American Society of heat is added to high-pressure steam to increase its temperature and enthalpy. { bȯilər ¦süMechanical Engineers code. { bȯilər kōd } boiler controls [MECH ENG] Either manual or pərhēdər } boiler trim [MECH ENG] Piping or tubing closeautomatic devices which maintain desired boiler operating conditions with respect to variables to or attached to a boiler for connecting controls, gages, or other instrumentation. { bȯilərsuch as feedwater flow, firing rate, and steam temperature. { bȯilər kəntrōlz } trim } boiler tube [MECH ENG] One of the tubes in aboiler draft [MECH ENG] The difference be- tween atmospheric pressure and some lower boiler that carry water (water-tube boiler) to be heated by the high-temperature gaseous prod-pressure existing in the furnace or gas passages of a steam-generating unit. { bȯilər draft } ucts of combustion or that carry combustion 68 Bond’s law products (fire-tube boiler) to heat the boiler wa- bomb calorimeter [ENG] A calorimeter de- signed with a strong-walled container con-ter that surrounds them. { bȯilər tüb } structed of a corrosion-resistant alloy, called theboiler walls [MECH ENG] The refractory walls of bomb, immersed in about 2.5 liters of water inthe boiler furnace, usually cooled by circulating ametal container; the sample, usually an organicwater and capable of withstanding high tempera- compound, is ignited by electricity, and the heattures and pressures. { bȯilər wȯlz } generated is measured. { bäm kalərimədboiler water [MECH ENG] Water in the steam- ər }generating section of a boiler unit. { bȯilər bombproof [ENG] Referring to shelter, building,wȯdər } or other installation resistant or impervious toboil-off [THERMO] The vaporization of a liquid, the effects of bomb explosions. { bämprüf }such as liquid oxygen or liquid hydrogen, as its bomb shelter [CIV ENG] A bomb-proof structuretemperature reaches its boiling point under con- for protection of people. { bäm sheltər }ditions of exposure, as in the tank of a rocket bomb test [ENG] A leak-testing technique in being readied for launch. { bȯilȯf } which the vessel to be tested is immersed in a bollard [CIV ENG] A heavy post on a dock or pressurized fluid which will be driven through ship used in mooring ships. { bälərd } any leaks present. { bäm test } bolograph [ENG] Any graphical record made by bond [CIV ENG] A piece of building material a bolometer; in particular, a graph formed by that serves to unite or bond, such as an arrange- directing a pencil of light reflected from the gal- ment of masonry units. [ELEC] The connec- vanometer of the bolometer at a moving photo- tion made by bonding electrically. [ENG] 1. A graphic film. { bōləgraf } wire rope that fixes loads to a crane hook. bolometer [ENG] An instrument that measures 2. Adhesion between cement or concrete and the energy of electromagnetic radiation in cer- masonry or reinforcement. { bänd } tain wavelength regions by utilizing the change Bond and Wang theory [MECH ENG] A theory in resistance of a thin conductor caused by the of crushing and grinding from which the energy, heating effect of the radiation. Also known as in horsepower-hours, required to crush a short thermal detector. { bəlämədər } ton of material is derived. { ¦bänd ən waŋ thē bolster [ENG] A plate for maintaining a fixed ərē } space between stacked heat exchangers or heat- bond course [BUILD] A course of headers to bond the facingmasonry to the backingmasonry.exchanger shells. { bōlstər } { bänd kȯrs }bolster plate [MECH ENG] A plate fixed on the bonded strain gage [ENG] A strain gage inbed of a power press to locate and support the which the resistance element is a fine wire, usu-die assembly. { bōlstər plāt } ally in zigzag form, embedded in an insulatingbolt [DES ENG] A rod, usually of metal, with a backing material, such as impregnated paper orsquare, round, or hexagonal head at one end plastic, which is cemented to the pressure-sens-and a screw thread on the other, used to fasten ing element. { ¦bändəd strān gāj }objects together. { bōlt } bonded transducer [ENG] A transducer whichbolt blank [DES ENG] A threadless bolt with a employs a bonded strain gage for sensing pres-head that can be threaded for specific applica- sure. { ¦bändəd tranzdüsər }tions. Also known as screw blank. { bōlt bonder See bondstone. { bändər }blaŋk } bond header [BUILD] In masonry, a stone thatbolted joint [ENG] The assembly of two or more extends the full thickness of the wall. Alsoparts by a threaded bolt and nut or by a screw known as throughstone. { bänd hedər }that passes through one member and threads bonding [ELEC] The use of low-resistance ma-into another. { ¦bōltəd jȯint } terial to connect electrically a chassis, metalbolted rail crossing [CIV ENG] A crossing whose shield cans, cable shielding braid, and other sup-running surfaces are made of rolled rail and posedly equipotential points to eliminate unde- whose parts are joined with bolts. { ¦bōltəd rāl sirable electrical interaction resulting from high-krȯsiŋ } impedance paths between them. [ENG] 1. The bolting [ENG] A fastening system using screw- fastening together of two components of a device threaded devices such as nuts, bolts, or studs. by means of adhesives, as in anchoring the cop- { bōltiŋ } per foil of printed wiring to an insulating base- bolt sleeve [DES ENG] A tube designed to sur- board. 2. See cladding. { bändiŋ } round a bolt in a concrete wall to prevent the bonding strength [MECH] Structural effective- concrete from adhering to the bolt. { bōlt ness of adhesives, welds, solders, glues, or of slēv } the chemical bond formed between the metallic Boltzmann engine [THERMO] An ideal thermo- and ceramic components of a cermet, when sub- dynamic engine that utilizes blackbody radia- jected to stress loading, for example, shear, ten- tion; used to derive the Stefan-Boltzmann law. sion, or compression. { bändiŋ streŋkth } { bōltsmən enjən } Bond’s law [MECH ENG] A statement that re- bomb ballistics [MECH] The special branch of lates the work required for the crushing of solid ballistics concerned with bombs dropped from materials (for example, rocks and ore) to the product size and surface area and the lengthsaircraft. { bäm bəlistiks } 69 Bond’s third theory of cracks formed. Also known as Bond’s third radio-frequency amplifier that amplifies and re- broadcasts a received television or communica-theory. { bänz lȯ } tion radio carrier frequency for reception by theBond’s third theory See Bond’s law. { bänz thərd general public. [MECH ENG] A compressorthēərē } that is used as the first stage in a cascade refrig-bondstone [BUILD] A stone joining the coping erating system. { büstər }above a gable to the wall. [CIV ENG] A ma- booster brake [MECH ENG] An auxiliary airsonry stone set with its longest dimension per- chamber, operated from the intake manifold vac-pendicular to the wall face to bind the wall to- uum, and connected to the regular brake pedal,gether. Also known as bonder. { bändstōn } so that less pedal pressure is required for brak-bond strength [ENG] The amount of adhesion ing. { büstər brāk }between bonded surfaces measured in terms of booster ejector [MECH ENG] A nozzle-shapedthe stress required to separate a layer of material apparatus fromwhich a high-velocity jet of steamfrom the base to which it is bonded. { bänd is discharged to produce a continuous-flow vac-streŋkth } uum for process equipment. { büstər ējek bond timber [BUILD] A section of wood built tər } horizontally into a brick or stone wall in order booster fan [MECH ENG] A fan used to increase to strengthen it or to hold it together during either the total pressure or the volume of flow. construction. { bänd timbər } { büstər fan } boom [ENG] 1. A row of joined floating timbers booster pump [MECH ENG] A machine used to that extend across a river or enclose an area increase pressure in a water or compressed-air of water for the purpose of keeping saw logs pipe. { büstər pəmp } together. 2. A temporary floating barrier booster stations [ENG] Booster pumps or com- launched on a body of water to contain material, pressors located at intervals along a liquid-prod- for example, an oil spill. 3. A structure con- ucts or gas pipeline to boost the pressure of sisting of joined floating logs placed in a stream the flowing fluid to keep it moving toward its to retard the flow. [MECH ENG] A movable destination. { büstər stāshənz } steel arm installed on certain types of cranes or bootjack [ENG] A fishing tool used in drilling derricks to support hoisting lines that must carry wells. { bütjak } loads. { büm } bootstrap [ENG] A technique or device de- signed to bring itself into a desired state byboom cat [MECH ENG] A tractor supporting a means of its own action. { bütstrap }boom and used in laying pipe. { büm kat } bootstrap circuit [ELECTR] A single-stage am-boom dog [MECH ENG] A ratchet device in- plifier in which the output load is connectedstalled on a crane to prevent the boom of the between the negative end of the anode supplycrane from being lowered but permitting it to be and the cathode, while signal voltage is appliedraised. Also known as boom ratchet. { büm between grid and cathode; a change in grid volt-dȯg } age changes the input signal voltage with respectboomer [ENG] A device used to tighten chains to ground by an amount equal to the outputon pipe or other equipment loaded on a truck signal voltage. { bütstrap sərkət }to make the cargo secure. { bümər } bootstrap driver [ELECTR] Electronic circuitboomerang sediment corer [ENG] A device, de- used to produce a square pulse to drive themod-signed for nighttime recovery of a sediment core, ulator tube; the duration of the square pulse iswhich automatically returns to the surface after determined by a pulse-forming line. { büttaking the sample. { büməraŋ sedəmənt strap drı̄vər }kȯrər } bootstrap integrator [ELECTR] A bootstrapboom ratchet See boom dog. { büm rachət } sawtooth generator in which an integrating am-boom stop [MECH ENG] A steel projection on plifier is used in the circuit. Also known asa crane that will be struck by the boom if it is Miller generator. { bütstrap intəgrādər } raised or lowered too great a distance. bootstrapping [ELECTR] A technique for lifting { büm stäp } a generator circuit above ground by a voltage Boord synthesis [CHEM ENG] A method of pro- value derived from its own output signal. { büt ducing alpha olefins by the reduction of alpha strapiŋ } bromo ethers with zinc. { bȯrd sinthəsəs } bootstrap sawtooth generator [ELECTR] A cir- boost [ELECTR] To augment in relative inten- cuit capable of generating a highly linear positive sity, as to boost the bass response in an audio sawtooth waveform through the use of boot- system. [ENG] To bring about a more potent strapping. { ¦bütstrap ¦sȯtüth jenərādər } explosion of the main charge of an explosive by bore [DES ENG] Inside diameter of a pipe or using an additional charge to set it off. { büst } tube. [MECH ENG] 1. The diameter of a pis- booster [ELEC] A small generator inserted in ton-cylinder mechanism as found in reciprocat- series or parallel with a larger generator to main- ing engines, pumps, and compressors. 2. To tain normal voltage output under heavy loads. penetrate or pierce with a rotary tool. 3. To [ELECTR] 1. A separate radio-frequency ampli- machine a workpiece to increase the size of an fier connected between an antenna and a tele- existing hole in it. { bȯr } borehole See drill hole. { bȯrhōl }vision receiver to amplify weak signals. 2. A 70 branch transmittance bpd See barrels per day. brake [MECH ENG] A machine element for bpm See barrels per month. applying friction to a moving surface to slow it brace [DES ENG] A cranklike device used for (and often, the containing vehicle or device) turning a bit. [ENG] A diagonally placed struc- down or bring it to rest. { brāk } tural member that withstands tension and com- brake band [MECH ENG] The contracting ele- pression, and often stiffens a structure against ment of the band brake. { brāk band } wind. { brās } brake block [MECH ENG] A portion of the band brace and bit [DES ENG] A small hand tool to brake lining, shaped to conform to the curvature which is attached a metal- or wood-boring bit. of the band and attached to it with countersunk { ¦brās ən bit } screws. { brāk bläk } braced framing [CIV ENG] Framing a building brake drum [MECH ENG] A rotating cylinder with post and braces for stiffness. { ¦brāst attached to a rotating part of machinery, which frāmiŋ } the brake band or brake shoe presses against. braced-rib arch [CIV ENG] A type of steel arch, { brāk drəm } usually used in bridge construction, which has brake horsepower [MECH ENG] The power de- a systemof diagonal bracing. { ¦brāst ¦rib ärch } veloped by an engine as measured by the force brace head [ENG] A cross handle attached at applied to a friction brake or by an absorption the top of a column of drill rods by means of dynamometer applied to the shaft or flywheel. which the rods and attached bit are turned after Abbreviated bhp. { ¦brāk hȯrspau̇ər } each drop in chop-and-wash operations while brake line [MECH ENG] One of the pipes or sinking a borehole through overburden. Also hoses that connect the master cylinder and the known as brace key. { brās hed } wheel cylinders in a hydraulic brake system. brace key See brace head. { brās kē } { brāk lı̄n } brace pile See batter pile. { brās pı̄l } brake lining [MECH ENG] A covering, riveted or brachiating motion [CONT SYS] A type of ro- molded to the brake shoe or brake band, which botic motion that employs legs or other equip- presses against the rotating brake drum; made ment to help the manipulator move in its work- of either fabric or molded asbestos material. ing environment. { ¦brākēādiŋ mōshən } { brāk liniŋ }brachiating robot [CONT SYS] A robot that is brake mean-effective pressure [MECH ENG]capable of moving over the surface of an object. Applied to reciprocating piston machinery, the{ ¦brākēādiŋ rōbät } average pressure on the piston during the powerbrachistochrone [MECH] The curve along stroke, derived from the measurement of brakewhich a smooth-sliding particle, under the influ- power output. { brāk ¦mēn ifektiv preshər }ence of gravity alone, will fall from one point to brake shoe [MECH ENG] The renewable frictionanother in the minimum time. { brəkistə element of a shoe brake. Also known as shoe.krōn } { brāk shü }bracing [ENG] The act or process of strengthen- brake thermal efficiency [MECH ENG] The ratioing or making rigid. { brāsiŋ } of brake power output to power input. { brākbracket [BUILD] A vertical board to support the thərməl əfishənsē }tread of a stair. [CIV ENG] A projecting sup- branch [ELEC] A portion of a network con-port. { brakət } sisting of one or more two-terminal elements inbrad [DES ENG] A small finishing nail whose series. Also known as arm. [ENG] In a pipingbody either is of uniform thickness or is ta- system, a pipe that originates in or dischargespered. { brad } into another pipe. Also known as branchbradding [ENG] A distortion of a bit tooth line. { branch }caused by the application of excessive weight, branch-and-bound technique [IND ENG] Acausing the tooth to become dull so that its technique in nonlinear programming in whichsofter inner portion caves over the harder case all sets of feasible solutions are divided intoarea. { bradiŋ } subsets, and those having bounds inferior toBragg spectrometer [ENG] An instrument for x- others are rejected. { ¦branch ən ¦bau̇ndray analysis of crystal structure and measuring teknēk }wavelengths of x-rays and gamma rays, in which branch gain See branch transmittance.a homogeneous beam of x-rays is directed on { branch gān }the known face of a crystal and the reflected branch line [CIV ENG] A secondary line in a rail-beam is detected in a suitably placed ionization road system that connects to the main line.chamber. Also known as crystal spectrometer; [ENG] See branch. { branch lı̄n }crystal-diffraction spectrometer; ionization spec- branch sewer [CIV ENG] A part of a sewer sys-trometer. { brag spekträmədər } tem that is larger in diameter than the lateralbraiding [ENG] Weaving fibers into a hollow sewer system; receives sewage from both housecylindrical shape. { brādiŋ } connections and lateral sewers. { ¦branch ¦sübrainstorming [IND ENG] A procedure used to ər }find a solution for a problem by collecting all branch transmittance [CONT SYS] The amplifi-the ideas, without regard for feasibility, which cation of current or voltage in a branch of anoccur from a group of people meeting together. { brān stȯrmiŋ } electrical network; used in the representation of 73 brandy such a network by a signal-flow graph. Also breaker cam [MECH ENG] A rotating, engine- driven device in the ignition systemof an internalknown as branch gain. { ¦branch transmitəns } brandy [CHEM ENG] A potable alcoholic bever- combustion engine which causes the breaker points to open, leading to a rapid fall in theage distilled from wine or fermented fruit juice, usually after the aging of the wine in wooden primary current. { brākər kam } breaker plate [ENG] In plastics die forming, acasks; cognac is a brandy distilled from wines made from grapes from the Cognac region of perforated plate at the end of an extruder head; often used to support a screen to keep foreignFrance. { brandē } Brayton cycle [THERMO] A thermodynamic cy- particles out of the die. { brākər plāt } break-even analysis [IND ENG] Determinationcle consisting of two constant-pressure proc- esses interspersed with two constant-entropy of the break-even point. { brākēvən ənalə səs }processes. Also known as complete-expansion diesel cycle; Joule cycle. { brātən sı̄kəl } break-even point [IND ENG] The point at which a company neither makes a profit nor suffers abrazed shank tool [MECH ENG] A metal cutting tool made of a material different from the shank loss from the operations of the business, and at which total costs are equal to total sales volume.to which it is brazed. { ¦brāzd shaŋk tül } breaching [MECH ENG] The space between the { brākēvən pȯint } break frequency [CONT SYS] The frequency atend of the tubing and the jacket of a hot-water or steam boiler. { brēchiŋ } which a graph of the logarithm of the amplitude of the frequency response versus the logarithmbreadboard model [ENG] Uncased assembly of an instrument or other piece of equipment, such of the frequency has an abrupt change in slope. Also known as corner frequency; knee frequency.as a radio set, having its parts laid out on a flat surface and connected together to permit a check { brāk frēkwənsē } breaking load [MECH] The stress which, whenor demonstration of its operation. { bredbȯrd mädəl } steadily applied to a structural member, is just sufficient to break or rupture it. Also known asbreakaway wrist [CONT SYS] A robotic wrist that has a safety feature that guarantees its pro- ultimate load. { brākiŋ lōd } breaking pin device [ENG] A device designedtection from damage if too much force is exerted on the wrist or end effector. { brākəwā rist } to relieve pressure resulting from inlet static pressure by the fracture of a loaded part of abreak-bulk cargo [IND ENG] Miscellaneous goods packed in boxes, bales, crates, cases, bags, pin. { brākiŋ pin divı̄s } breaking strength [MECH] The ability of amate-cartons, barrels, or drums; may also include lum- ber, motor vehicles, pipe, steel, and machinery. rial to resist breaking or rupture from a tension force. { brākiŋ streŋkth }{ ¦brāk ¦bəlk kärgo } breakdown [ELEC] A large, usually abrupt rise breaking stress [MECH] The stress required to fracture a material whether by compression, ten-in electric current in the presence of a small increase in voltage; can occur in a confined gas sion, or shear. { brākiŋ stres } breakout [ELEC] A joint at which one or morebetween two electrodes, a gas tube, the atmos- phere (as lightning), an electrical insulator, and conductors are brought out from a multiconduc- tor cable. [ENG] Failure or collapse of a bore-a reverse-biased semiconductor diode. Also known as electrical breakdown. { brākdau̇n } hole wall due to stress anisotropy. { brākau̇t } breakout schedule [IND ENG] A schedule for abreakdown diode [ELEC] A semiconductor di- ode in which the reverse-voltage breakdown construction job site, generally in the form of a bar chart, that communicates detailed day-to-mechanism is based either on the Zener effect or the avalanche effect. { brākdau̇n ¦dı̄ōd } day activities to all working levels on the project. { brākau̇t skejəl }breakdown impedance [ELECTR] Of a semicon- ductor, the small-signal impedance at a specified breakover [ELECTR] In a silicon controlled rec- tifier or related device, a transition into forwarddirect current in the breakdown region. { brāk dau̇n impēdəns } conduction caused by the application of an ex- cessively high anode voltage. { brākōvər }breakdown potential See breakdown voltage. { brākdau̇n pətenshəl } breakover voltage [ELECTR] The positive anode voltage at which a silicon controlled recti-breakdown region [ELECTR] Of a semiconduc- tor diode, the entire region of the volt-ampere fier switches into the conductive state with gate circuit open. { brākōvər vȯltij }characteristic beyond the initiation of break- down for increasing magnitude of bias. { brāk breakpoint [CHEM ENG] See breakthrough. [IND ENG] In a time study, the end of an elementdau̇n rējən } breakdown voltage [ELEC] 1. The voltage in a work cycle and the point at which a reading is made. Also known as end point; readingmeasured at a specified current in the electrical breakdown region of a semiconductor diode. point. { brākpȯint } breakthrough [CHEM ENG] 1. A localized breakAlso known as Zener voltage. 2. The voltage at which an electrical breakdown occurs in a dielec- in a filter cake or precoat that permits fluid to pass through without being filtered. Alsotric. 3. The voltage at which an electrical break- down occurs in a gas. Also known as break- known as breakpoint. 2. In an ion-exchange system, the first appearance of unadsorbed ionsdown potential; sparking potential; sparking voltage. { brākdau̇n vȯltij } of the type which deplete the activity of the resin 74 bridge vibration bed; this indicates that the bed must be regener- window and the masonry into which the frame has been set. { ¦brik ¦mōldiŋ }ated. { brākthrü } brick seat [BUILD] A ledge on a footing or a wallbreakwater [CIV ENG] A wall built into the sea for supporting a course ofmasonry. { brik sēt }to protect a shore area, harbor, anchorage, or bridge [CIV ENG] A structure erected to spanbasin from the action of waves. { brākwȯdər } natural or artificial obstacles, such as rivers,breast boards [CIV ENG] Timber planks used to highways, or railroads, and supporting a foot-support the tunnel face when excavation is in path or roadway for pedestrian, highway, or rail-loose soil. { brest bȯrdz } road traffic. [ELEC] 1.An electrical instrumentbreast drill [DES ENG] A small, portable hand having four or more branches, by means of whichdrill customarily used by handsetters to drill the one or more of the electrical constants of anholes in bit blanks in which diamonds are to be unknown component may be measured. 2. Anset; it includes a plate that is pressed against electrical shunt path. { brij }the worker’s breast. { brest dril } bridge abutment [CIV ENG] The end foundationbreasting dolphin [CIV ENG] A pile or other upon which the bridge superstructure rests.structure against which a moored ship rests. { brij əbətmənt }{ ¦brestiŋ ¦dälfən } bridge bearing [CIV ENG] The support at abreast wall [CIV ENG] A low wall built to retain bridge pier carrying the weight of the bridge; maythe face of a natural bank of earth. { brest be fixed or seated on expansion rollers. { brijwȯl } beriŋ }breather pipe [MECH ENG] A pipe that opens bridge cable [CIV ENG] Cable from which ainto a container for ventilation, as in a crankcase roadway or truss is suspended in a suspensionor oil tank. Also known as crankcase breather. bridge; may be of pencil-thick wires laid parallel{ brēthər pı̄p } or strands of wire wound spirally. { brij kabreath-hold diving [ENG] A form of diving with- bəl } out the use of any artificial breathing mixtures. bridge crane [MECH ENG] A hoisting machine { breth hōld diviŋ } in which the hoisting apparatus is carried by abreathing [ENG] 1. Opening and closing of a bridgelike structure spanning the area over plastics mold in orderto let gases escape during which the crane operates. { brij krān } molding. Also known as degassing. 2. Move- bridge foundation [CIV ENG] The piers and ment of gas, vapors, or air in and out of a storage- abutments of a bridge, on which the superstruc- tank vent line as a result of liquid expansions and ture rests. { brij fau̇ndāshən } contractions induced by temperature changes. bridge hybrid See hybrid junction. { brij hı̄ { brēthiŋ } brəd } breathing apparatus [ENG] An appliance that bridge limiter [ELECTR] A device employed in enables a person to function in irrespirable or analog computers to keep the value of a variable poisonous gases or fluids; contains a supply of within specified limits. { ¦brij ¦limədər } oxygen and a regenerator which removes the car- bridge magnetic amplifier [ELECTR] A mag- bon dioxide exhaled. { brēthiŋ apəradəs } netic amplifier in which each of the gate windings breathing bag [ENG] A component of a sem- is connected in series with an arm of a bridge iclosed-circuit breathing apparatus that mixes rectifier; the rectifiers provide self-saturation and the gases to provide low breathing resistance. direct-current output. { ¦brij magnedik am { brēthiŋ bag } pləfı̄ər } breathing line [CIV ENG] A level of 5 feet (1.5 bridge oscillator [ELECTR] An oscillator using a meters) above the floor; suggested temperatures balanced bridge circuit as the feedback network. for various occupancies of rooms and other { brij äsəlādər } chambers are usually given at this level. bridge pier [CIV ENG] The main support for a { brēthiŋ lı̄n } bridge, upon which the bridge superstructure breeching [MECH ENG] A duct through which rests; constructed of masonry, steel, timber, or the products of combustion are transported from concrete founded on firm ground below river the furnace to the stack; usually applied in steam mud. { brij pir } boilers. { brēchiŋ } bridge rectifier [ELECTR] A full-wave rectifier Brennan monorail car [MECH ENG] A type of with four elements connected as a bridge circuit car balanced on a single rail so that when the with direct voltage obtained from one pair of car starts to tip, a force automatically applied at opposite junctions when alternating voltage is the axle end is converted gyroscopically into a applied to the other pair. { ¦brij rektəfı̄ər } strong rightingmoment which forces the car back bridge trolley [MECH ENG] Either of the into a position of lateral equilibrium. { ¦bren wheeled attachments at the ends of the bridge ən mänərāl kär } of an overhead traveling crane, permitting the Brewster process [CHEM ENG] Concentration bridge to move backward and forward on ele- of dilute acetic acid by use of an extraction sol- vated tracks. { brij trälē } vent (for example, isopropyl ether), followed by bridge vibration [MECH] Mechanical vibration distillation. { brüstər präsəs } of a bridge superstructure due to natural and brick molding [BUILD] A wooden molding ap- human-produced excitations. { brij vı̄brā shən }plied to the gap between the frame of a door or 75 bucket-ladder excavator known as bucket ladder; bucket-line dredge; buffing wheel [DES ENG] A flexible wheel with a surface of fine abrasive particles for buffingladder-bucket dredge; ladder dredge. { bəkət ladər drej } operations. { bəfiŋ wēl } bug [ELECTR] 1. A semiautomatic code-send-bucket-ladder excavator See trench excavator. { bəkət ladər ekskəvādər } ing telegraph key in which movement of a lever to one side produces a series of correctly spacedbucket-line dredge See bucket-ladder dredge. { bəkət lı̄n drej } dots and movement to the other side produces a single dash. 2. An electronic listening device,bucket loader [MECH ENG] A form of portable, self-feeding, inclined bucket elevator for loading generally concealed, used for commercial or mil- itary espionage. [ENG] 1. A defect or imper-bulk materials into cars, trucks, or other con- veyors. { bəkət lōdər } fection present in a piece of equipment. 2. See bullet. { bəg }bucket temperature [ENG] The surface temper- ature of ocean water as measured by a bucket buggy See concrete buggy. { bəgē } buhrstone mill [MECH ENG] A mill for grindingthermometer. { bəkət ¦temprəchər } bucket thermometer [ENG] A thermometer or pulverizing grain in which a flat siliceous rock (buhrstone), generally of cellular quartz, rotatesmounted in a bucket and used to measure the temperature of water drawn into the bucket from against a stationary stone of the same material. { bərstōn mil }the surface of the ocean. { bəkət thərmäm ədər } build [ELECTR] To increase in received signal strength. { bild }bucket-wheel excavator [MECH ENG] A contin- uous digging machine used extensively in large- building [CIV ENG] A fixed structure for human occupancy and use. { bildiŋ }scale stripping and mining. Abbreviated BWE. Also known as rotary excavator. { bəkət wēl building-block approach [IND ENG] A tech- nique for development of a set of standard dataekskəvādər } Buckingham’s equations [MECH ENG] by creating fixed groups or modules of work ele- ments that may be added together to obtainEquations which give the durability of gears and the dynamic loads to which they are subjected time values for elements and entire operations. { bildiŋ bläk əprōch }in terms of their dimensions, hardness, surface endurance, and composition. { bəkiŋəmz building code [CIV ENG] Local building laws to promote safe practices in the design and con-ikwāzhənz } buckle plate [CIV ENG] A steel floor plate which struction of a building. { bildiŋ kōd } building dock [CIV ENG] A type of graving dockis slightly arched to increase rigidity. { bəkəl plāt } or basin, usually built of concrete, in which ships are constructed and then floated out throughBuckley gage [ENG] A device that measures very low gas pressures by sensing the amount a caisson gate after flooding the dock. { bil diŋ däk }of ionization produced in the gas by a predeter- mined electric current. { bəklē gāj } building envelope [CIV ENG] The interior, en- closed space of a building. { bildiŋ enbuckling [ENG] Wrinkling or warping of fibers in a composite material. [MECH] Bending of vəlōp } building footprint See footprint. { bildiŋa sheet, plate, or column supporting a compres- sive load. { bəkliŋ } fu̇tprint } building line [CIV ENG] A designated line be-buckling stress [MECH] Force exerted by the crippling load. { bəkliŋ stres } yond which a building cannot extend. { bil diŋ lı̄n }buckstay [MECH ENG] A structural support for a furnace wall. { bəkstā } buildup index See fire-danger meter. { bildəp indeks }buffer [ELEC] An electric circuit or component that prevents undesirable electrical interac- built-in beam See fixed-end beam. { ¦biltin bēm } built-up beam [ENG] A structural steel membertion between two circuits or components. [ELECTR] 1. An isolating circuit in an electronic that is fabricated by welding or riveting rather than being rolled. { biltəp bēm }computer used to prevent the action of a driven circuit from affecting the corresponding driving built-up edge [ENG] Chip material adhering to the tool face adjacent to a cutting edge duringcircuit. 2. See buffer amplifier. [ENG] A de- vice, apparatus, or piece of material designed to cutting. { biltəp ej } built-up roof [BUILD] A roof constructed of sev-reduce mechanical shock due to impact. { bəfər } eral layers of felt and asphalt. { biltəp rüf } bulb angle [DES ENG] A steel angle iron en-buffered FET logic [ELECTR] A logic gate con- figuration used with gallium-arsenide field-effect larged to a bulbous thickening at one end. { bəlb aŋgəl }transistors operating in the depletion mode, in which the level shifting required to make the bulge forming [ENG] A process by which con- tours are formed on the sides of tubular work-input and output voltage levels compatible is achieved with Schottky barrier diodes. Abbrevi- pieces by exerting pressure inside the tube to force expansion into a die clamped around theated BFL. { bəfərd ¦ef¦ē¦tē läjik } buffing [ENG] The smoothing and brightening exterior. { bəlj fȯrmiŋ } bulk cargo [IND ENG] Cargo which is loadedof a surface by an abrasive compound pressed against it by a soft wheel or belt. { bəfiŋ } into a ship’s hold without being boxed, bagged, 78 Bulygen number or hand stowed, or is transported in large tank and other unique properties that depend on the semiconductor and doping materials used.spaces. { ¦bəlk kärgō } bulk density [ENG] The mass of powdered or { ¦bəlk ¦fōdōkən¦dəktər } bulk resistor [ELECTR] An integrated-circuit re-granulated solid material per unit of volume. { ¦bəlk densədē } sistor in which the n-type epitaxial layer of a semiconducting substrate is used as a noncriti-bulk diode [ELECTR] A semiconductor micro- wave diode that uses the bulk effect, such as cal high-value resistor; the spacing between the attached terminals and the sheet resistivity ofGunn diodes and diodes operating in limited space-charge-accumulation modes. { ¦bəlk dı̄ the material together determine the resistance value. { bəlk rizistər }ōd } bulk effect [ELECTR] An effect that occurs bulk strain [MECH] The ratio of the change in the volume of a body that occurs when the bodywithin the entire bulk of a semiconductor mate- rial rather than in a localized region or junction. is placed under pressure, to the original volume of the body. { balk strān }{ bəlk ifekt } bulk-effect device [ELECTR] A semiconductor bulk strength [MECH] The strength per unit vol- ume of a solid. { ¦bəlk streŋkth }device that depends on a bulk effect, as in Gunn and avalanche devices. { bəlk ifekt divı̄s } bulk transport [MECH ENG] Conveying, hoisting, or elevating systems for movement ofbulk factor [ENG] The ratio of the volume of loose powdered or granulated solids to the vol- solids such as grain, sand, gravel, coal, or wood chips. { ¦bəlk tranzpȯrt }ume of an equal weight of the material after consolidation into a voidless solid. { bəlk bulldozer [MECH ENG] A wheeled or crawler tractor equipped with a reinforced, curved steelfaktər } bulk-handling machine [MECH ENG] Any of a plate mounted in front, perpendicular to the ground, for pushing excavated materials. { bu̇ldiversified group of materials-handling ma- chines designed for handling unpackaged, di- dōzər } bullet [ENG] 1. A conical-nosed cylindricalvided materials. { bəlk handliŋ məshēn } bulkhead line [CIV ENG] The farthest offshore weight, attached to a wire rope or line, either notched or seated to engage and attach itself toline to which a structure may be constructed without interfering with navigation. { bəlk the upper end of a wire line core barrel or other retrievable or retractable device that has beenhed lı̄n } bulkhead wharf [CIV ENG] A bulkhead that may placed in a borehole. Also known as bug; go- devil; overshot. 2. A scraper with self-adjustingbe used as a wharf by addition of mooring appur- tenances, paving, and cargo-handling facilities. spring blades, inserted in a pipeline and carried forward by the fluid pressure, clearing away accu-{ bəlkhed wȯrf } bulking value [CHEM ENG] The relative ability mulations or debris from the walls of a pipe. Also known as go-devil. 3. A bullet-shapedof a pigment or other substance to increase the volume of paint. { bəlkiŋ valyü } weight or small explosive charge dropped to ex- plode a charge of nitroglycerin placed in a bore-bulk insulation [ENG] A type of insulation that retards the flow of heat by the interposition of hole. Also known as go-devil. 4. An electric lamp covered by a conical metal case, usually atmany air spaces and, in most cases, by opacity to radiant heat. { ¦bəlk insəlāshən } the end of a flexiblemetal shaft. 5. See torpedo. { bu̇lət }bulk material [IND ENG] Material purchased in uniform lots and in quantity for distribution as bullet drop [MECH] The vertical drop of a bullet. { bu̇lət dräp }required for a project. { ¦bəlk mə¦tirēəl } bulk micromachining [ENG] A set of processes bull gear [DES ENG] A bull wheel with gear teeth. { bu̇l gir }that enable the three-dimensional sculpting of single-crystal silicon to make small structures bulling bar [ENG] A bar for ramming clay into cracks containing blasting charges which arethat serve as components of microsensors. { ¦bəlk mı̄krōməshēniŋ } about to be exploded. { bu̇liŋ bär } bull nose [BUILD] A rounded external angle, asbulk modulus See bulk modulus of elasticity. { ¦bəlk mäjələs } one used at window returns and doorframes. { bu̇l nōz }bulk modulus of elasticity [MECH] The ratio of the compressive or tensile force applied to a bull-nose bit See wedge bit. { bu̇l nōz bit } bull-nose plane [DES ENG] A small rabbetsubstance per unit surface area to the change in volume of the substance per unit volume. Also plane used to smooth or shape joints or other places that cannot be reached by larger planes.known as bulk modulus; compression modulus; hydrostatic modulus; modulus of compression; { ¦bu̇l nōz plān } bull wheel [MECH ENG] 1. The main wheel ormodulus of volume elasticity. { ¦bəlk mäjləs əv ilastisədē } gear of a machine, which is usually the largest and strongest. 2. A cylinder which has a ropebulk rheology [MECH] The branch of rheology wherein study of the behavior of matter neglects wound about it for lifting or hauling. 3. A wheel attached to the base of a derrick boom whicheffects due to the surface of a system. { ¦bəlk rēäləjē } swings the derrick in a vertical plane. { bu̇l wēl }bulk photoconductor [ELECTR] A photocon- ductor having high power-handling capability Bulygen number [THERMO] A dimensionless 79 bump contact number used in the study of heat transfer during arrays are designed for telemetering. { bȯi evaporation. { büləjən nəmbər } sensər } bump contact [ELECTR] A large-area contact burden [ELEC] The amount of power drawn used for alloying directly to the substrate of a from the circuit connecting the secondary termi- transistor for mounting or interconnecting pur- nals of an instrument transformer, usually ex- poses. { bəmp käntakt } pressed in volt-amperes. [ENG] 1. The dis- bumper [ENG] 1. A metal bar attached to one tance from a drill hole to the more or less vertical or both ends of a powered transportation vehicle, surface of rock that has already been exposed especially an automobile, to prevent damage to by blasting or excavating. 2. The volume of the the body. 2. In a drilling operation, the support- rock to be removed by blasting in a drill hole. ing stay between the main foundation sill and { bərdən } the engine block. 3. In drilling, a fishing tool burglar alarm [ENG] An alarm in which inter- for loosening jammed cable tools. { bəmpər } ruption of electric current to a relay, caused, for bumping See chugging. { bəmpiŋ } example, by the breaking of a metallic tape bund [CIV ENG] An embankment or embanked placed at an entrance to a building, deenergizes thoroughfare along a body of water; the term is the relay and causes the relay contacts to operate used particularly for such structures in the Far the alarm indicator. Also known as intrusion East. { bənd } alarm. { bərglər ə¦lärm } bundling machine [MECH ENG] A device that buried set-point method [CONT SYS] A proce- automatically accumulates cans, cartons, or dure for guiding a robot manipulator along a glass containers for semiautomatic or automatic template, in which low-gain servomechanisms loading or for shipping cartons by assembling apply a force along the edge of the template, the packages into units of predetermined count while the manipulator’s tool is parallel to, and and pattern which are then machine-wrapped buried below, the template surface. { berēd in paper, film paperboard, or corrugated board. setpȯint methəd } { bəndliŋ məshēn } burn [ENG] To consume fuel. { bərn }bund wall [ENG] A retaining wall designed to burn cut See parallel cut. { bərn kət } contain the contents of a tank or a storage vessel burner [CHEM ENG] A furnace where sulfur orin the event of a rupture or other emergency. sulfide ore are burned to produce sulfur dioxide{ bənd wȯl } and other gases. [ENG] 1. The part of a fluid-bunker [CIV ENG] A bin, often elevated, that is burning device at which the flame is produced.divided into compartments for storing material 2. Any burning device used to soften old paintsuch as coal or sand. [MECHENG] A space in a to aid in its removal. 3. A worker who operatesrefrigerator designed to hold a cooling element. a kiln which burns brick or tile. 4. A worker who{ bəŋkər } alters the properties of a mineral substance bybunkering [ENG] Storage of solid or liquid fuel burning. 5. A worker who uses a flame-cuttingin containers from which the fuel can be continu- torch to cut metals. [MECH ENG] A unit of aously or intermittently withdrawn to feed a fur- steam boiler which mixes and directs the flownace, internal combustion engine, or fuel tank, of fuel and air so as to ensure rapid ignition andfor example, coal bunkering and fuel-oil bunker- complete combustion. { bərnər }ing. { bəŋkəriŋ } burner windbox [ENG] A chamber surroundingbunny suit [ENG] Protective clothing worn by a burner, under positive air pressure, for properan individual who works in a clean room to pre- distribution and discharge of secondary air.vent contamination of equipment and materials. { bərnər windbäks }{ bənē süt } burnettize [ENG] To saturate fabric or woodBunsen burner [ENG] A type of gas burner with with a solution of zinc chloride under pressurean adjustable air supply. { bənsən bərnər } to keep it from decaying. { bərnedı̄z }Bunsen ice calorimeter [ENG] Apparatus to burn-in [ELECTR] Operation of electronic com-gage heat released during the melting of a com- ponents before they are applied in order to stabi-pound by measuring the increase in volume of lize their characteristics and reveal defects.the surrounding ice-water solution caused by the [ENG] See freeze. { bərn in }melting of the ice. Also known as ice calorime- burning [ENG] The firing of clay productster. { bənsən ı̄s kalərimədər } placed in a kiln. { bərniŋ }buoy [ENG] An anchored or moored floating burning index See fire-danger meter. { bərniŋobject, other than a lightship, intended as an aid ¦indeks }to navigation, to attach or suspend measuring burning point [ENG] The lowest temperature atinstruments, or to mark the position of some- which a volatile oil in an open vessel will con-thing beneath the water. { bȯi } tinue to burn when ignited by a flame held closebuoyancy-type density transmitter [ENG] An to its surface; used to test safety of kerosine andinstrument which records the specific gravity of other illuminating oils. { bərniŋ pȯint }a flowing stream of a liquid or gas, using the burning quality [ENG] Rated performance for aprinciple of hydrostatic weighing. { bȯiənsē burning oil as determined by specified ASTMtı̄p densədē tranzmidər } (American Society for Testing and Materials)buoy sensor [ENG ACOUS] A hydrophone used as a sensor in buoy projects; some hydrophone tests. { bərniŋ kwal ədē } 80 C is driven by a stationary engine. { kābəlc See calorie. ¦rālwā }C See capacitance; capacitor; coulomb. cable release [ENG] A wire plunger to actuateC2 See command and control. { sē tü } the shutter of a camera, thus avoiding undesir-C3 See command, control, and communications. able camera movement. { kābəl rilēs }{ sē thrē } cable-stayed bridge [CIV ENG] A modificationcab [ENG] In a locomotive, truck, tractor, or of the cantilever bridge consisting of girders orhoisting apparatus, a compartment for the oper- trusses cantilevered both ways from a centralator. { kab } tower and supported by inclined cables attachedcabinet file [DES ENG] A coarse-toothed file to the tower at top or sometimes at severalwith flat and convex faces used for woodworking. levels. { kābəl stād brij }{ kabənət fı̄l } cable-system drill See churn drill. { kābəl ¦siscabinet hardware [DES ENG] Parts for the final təm dril }trim of a cabinet, such as fastening hinges, cable-tool drilling [ENG] A drilling procedure indrawer pulls, and knobs. { kabənət ¦härd which a sharply pointed bit attached to a cablewer } is repeatedly picked up and dropped on the bot-cabinet saw [DES ENG] A short saw, one edge tom of the hole. { kābəl ¦tül driliŋ }used for ripping, the other for crosscutting. cable vault [CIV ENG] A manhole containing{ kabənət sȯ } electrical cables. [ELEC] Vault in which thecabinet scraper [DES ENG] A steel tool with a outside plant cables are spliced to the tippingcontoured edge used to remove irregularities on cables. { kābəl vȯlt }a wood surface. { kabənət skrāpər } cableway [MECH ENG] A transporting systemcable [DES ENG] A stranded, ropelike assembly consisting of a cable extended between two orof wire or fiber. [ELEC] Strands of insulated more points on which cars are propelled to trans- electrical conductors laid together, usually port bulk materials for construction operations. around a central core, and surrounded by a heavy { kābəlwā } insulation. { kābəl } cableway carriage [MECH ENG] A trolley that cable buoy [ENG] A buoy used to mark one end runs on main load cables stretched between two of a submarine underwater cable during time of or more towers. { kābəlwā karij } installation or repair. { kābəl bȯi } caboose [ENG] A car on a freight train, often cable conveyor [MECH ENG] A powered con- the last car, usually for use by the train crew. veyor in which a trolley runs on a flexible, torque- { kəbüs } transmitting cable that has helical threads. cab signal [ENG] A signal in a locomotive that { kābəl kənvāər } informs the engine operator about conditions cable drilling [ENG] Rock drilling in which the affecting train movement. { kab signəl } rock is penetrated by percussion, at the bottom cadastral survey [CIV ENG] A survey made to of the hole, of a bit suspended from a wire line establish property lines. { kədastrəl } and given motion by a beam pivoted at the cen- cage [MECH ENG] A frame for maintaining uni- ter. { kābəl driliŋ } form separation between the balls or rollers in cable duct [ENG] A pipe, either earthenware or a bearing. Also known as separator. { kāj } concrete, through which prestressing wires or cage mill [MECH ENG] Pulverizer used to disin- electric cable are pulled. { kābəl dəkt } tegrate clay, press cake, asbestos, packing-house cable-laid [DES ENG] Consisting of three ropes by-products, and various tough, gummy, high- with a left-hand twist, each rope having three moisture-content or low-melting-point materi- twisted strands. { kābəl lād } als. { kāj mil } cableman [ENG] A person who installs, repairs, cairn [ENG] An artificial mound of rocks, or otherwise works with cables. { kābəlmən } stones, or masonry, usually conical or pyramidal, cable railway [MECH ENG] An inclined track on whose purpose is to designate or to aid in identi- which rail cars travel, with the cars fixed to an fying a point of surveying or of cadastral impor- tance. { kern }endless steel-wire rope at equal spaces; the rope Copyright 2003 by The McGraw-Hill Companies, Inc. Click Here for Terms of Use. caisson caisson [CIV ENG] 1. A watertight, cylindrical or or jaws that can be adjusted for measuring linear rectangular chamber used in underwater con- dimensions, thickness, or diameter. { kalə struction to protect workers from water pressure pər } and soil collapse. 2. A float used to raise a caliper gage [DES ENG] An instrument, such as sunken vessel. 3. See dry-dock caisson. { kā a micrometer, of fixed size for calipering. { kal sän } əpər gāj } caisson foundation [CIV ENG] A shaft of con- calk See caulk. { kȯk } crete placed under a building column or wall Callendar and Barnes’ continuous-flow calori- and extending down to hardpan or rock. Also meter [ENG] A calorimeter in which the heat known as pier foundation. { kāsän fou̇ndā to be measured is absorbed by water flowing shən } through a tube at a constant rate, and the quan- caking [ENG] Changing of a powder into a solid tity of heat is determined by the rate of flow mass by heat, pressure, or water. { kākiŋ } and the temperature difference between water at cal See calorie. ends of the tube. { ¦kaləndər ən bärnz kəntin Cal See kilocalorie. yəwəs flō kalərimədər } calandria [CHEM ENG] One of the tubes Callendar’s compensated air thermometer [ENG] through which the heating fluid circulates in an A type of constant-pressure gas thermometer in evaporator. { kəlandrēə } which errors resulting from temperature differ- calandria evaporator See short-tubevertical evapo- ences between the thermometer bulb and the rator. { kəlandrēə ivapərādər } connecting tubes and manometer used to main- calcimeter [ENG] An instrument for estimating tain constant pressure are eliminated by the con- the amount of lime in soils. { kalsimədər } figuration of the connecting tubes. { ¦kalən calcination [CHEM ENG] A process in which a dərz ¦kämpənsādəd er thərmämədər } material is heated to a temperature below its Callendar’s equation [THERMO] 1. An equation melting point to effect a thermal decomposition of state for steam whose temperature is well or a phase transition other than melting. { kal above the boiling point at the existing pressure, sənāshən } but is less than the critical temperature: (V b)calcine [ENG] 1. To heat to a high temperature (RT/p) (a/Tn), where V is the volume, R iswithout fusing, as to heat unformed ceramic the gas constant, T is the temperature, p is thematerials in a kiln, or to heat ores, precipitates, pressure, n equals 10/3, and a and b are con-concentrates, or residues so that hydrates, car- stants. 2. A very accurate equation relatingbonates, or other compounds are decomposed temperature and resistance of platinum, ac-and the volatile material is expelled. 2. To heat cording to which the temperature is the sum ofunder oxidizing conditions. { kalsı̄n } a linear function of the resistance of platinumcalcining furnace [ENG] A heating device, such and a small correction term, which is a quadraticas a vertical-shaft kiln, that raises the tempera- function of temperature. { kaləndərz ikwāture (but not to themelting point) of a substance zhən }such as limestone to make lime. Also known Callendar’s thermometer See platinum resistanceas calciner. { kalsiniŋ fərnəs } thermometer. { kaləndərz thərmämədər }calefaction [ENG] 1. Warming. 2. The condi- calorie [THERMO] Abbreviated cal; often desig-tion of being warmed. { ¦kalə¦fakshən } nated c. 1. A unit of heat energy, equal tocalender [ENG] 1. To pass a material between 4.1868 joules. Also known as Internationalrollers or plates to thin it into sheets or to make Table calorie (IT calorie). 2. A unit of energy,it smooth and glossy. 2. The machine which equal to the heat required to raise the tempera-performs this operation. { kaləndər } ture of 1 gram of water from 14.5 to 15.5C atcalibrating tank [ENG] A tank having known ca- a constant pressure of 1 standard atmosphere;pacity used to check the volumetric accuracy of equal to 4.1855 0.0005 joules. Also knownliquid delivery by positive-displacement meters. as fifteen-degrees calorie; gram-calorie (g-cal);Also known as meter-proving tank. { kal small calorie. 3. A unit of heat energy equaləbrādiŋ taŋk } to 4.184 joules; used in thermochemistry. Alsocalibration curve [ENG] A plot of calibration known as thermochemical calorie. { kalərē }data, giving the correct value for each indicated calorific value [ENG] Quantity of heat liberatedreading of a meter or control dial. { kaləbrā on the complete combustion of a unit weight orshən kərv } unit volume of fuel. { ¦kalə¦rifik valyü }calibration markers [ENG] On a radar display, calorifier [ENG] A device that heats fluids byelectronically generated marks which provide circulating them over heating coils. { kəlȯrnumerical values for the navigational parameters əfı̄ər }such as bearing, distance, height, or time. calorimeter [ENG] An apparatus for measuring{ kaləbrāshən märkərz } heat quantities generated in or emitted by mate-California polymerization [CHEM ENG] A poly- rials in processes such as chemical reactions,merization process for converting C3C4 olefins changes of state, or formation of solutions.to motor fuel by utilizing a catalyst of phosphoric { kalərimədər }acid on quartz chips. { ¦kalə¦fȯrnyə pəlimə calorimetric test [ENG] The use of a calorimeterrəzāshən } caliper [DES ENG] An instrument with two legs to determine the thermochemical characteristics 84 cantilever of propellants and explosives; properties nor- cam profile [DES ENG] The shape of the con- toured cam surface by means of which motionmally determined are heat of combustion, heat of explosion, heat of formation, and heat of reac- is communicated to the follower. Also known as pitch line. { kam prōfı̄l }tion. { kə¦lȯrə¦metrik test } calorimetry [ENG] The measurement of the camshaft [MECH ENG] A rotating shaft to which a cam is attached. { kamshaft }quantity of heat involved in various processes, such as chemical reactions, changes of state, can [DESENG] A cylindricalmetal vessel or con- tainer, usually with an open top or a removableand formations of solutions, or in the determina- tion of the heat capacities of substances; funda- cover. { kan } canal [CIV ENG] An artificial open waterwaymental unit of measurement is the joule or the calorie (4.184 joules). { kalərimətrē } used for transportation, waterpower, or irriga- tion. [DES ENG] A groove on the underside ofcalyx [ENG] A steel tube that is a guide rod and is also used to catch cuttings from a drill rod. a corona. { kənal } canalization [ENG] Any system of distributionAlso known as bucket; sludge barrel; sludge bucket. { kāliks } canals or conduits for water, gas, electricity, or steam. { kanələzāshən }calyx drill [ENG] A rotary core drill with hard- ened steel shot for cutting rock. Also known as cancellation circuit [ELECTR] A circuit used in providing moving-target indication on a planshot drill. { kāliks dril } cam [MECHENG] A plate or cylinder which com- position indicator scope; cancels constant- amplitude fixed-target pulses by subtraction ofmunicates motion to a follower by means of its edge or a groove cut in its surface. { kam } successive pulse trains. { kansəlāshən sər kət }cam acceleration [MECHENG] The acceleration of the cam follower. { kam akselərāshən } canister See charcoal canister. { kanəstər } canned motor [MECH ENG] A motor enclosedcamber [DES ENG] Deviation from a straight line; the term is applied to a convex, edgewise within a casing along with the driven element (that is, a pump) so that the motor bearingssweep or curve, or to the increase in diameter at the center of rolled materials. { kambər } are lubricated by the same liquid that is being pumped. { ¦kand mōdər }camber angle [MECHENG] The inclination from the vertical of the steerable wheels of an automo- canned pump [MECH ENG] A watertight pump that can operate under water. { ¦kand pəmp }bile. { kambər aŋgəl } cam cutter [MECHENG] A semiautomatic or au- cannibalize [ENG] To remove parts from one piece of equipment and use them to replace like,tomatic machine that produces the cam contour by swinging the work as it revolves; uses amaster defective parts in a similar piece of equipment in order to keep the latter operational. { kancam in contact with a roller. { kam kədər } cam dwell [DES ENG] That part of a cam surface əbəlı̄z } canonical equations of motion See Hamilton’sbetween the opening and closing acceleration sections. { kam dwel } equations of motion. { kənänəkəl ikwā zhənz əv mōshən }cam engine [MECH ENG] A piston engine in which a cam-and-roller mechanism seems to canonical form [CONT SYS] A specific type of dynamical system representation in which theconvert reciprocating motion into rotary motion. { kam enjən } associated matrices possess specific row-col- umn structures. { kənänəkəl fȯrm }camera study See memomotion study. { kamrə stədē } canonically conjugate variables [MECH] A gen- eralized coordinate and its conjugate momen-cam follower [MECH ENG] The output link of a cam mechanism. { kam fäləwər } tum. { kənänəklē ¦kanjəgət verēəbəlz } canonical momentum See conjugate momentum.cam mechanism [MECH ENG] A mechanical linkage whose purpose is to produce, by means { kənänəkəl məmentəm } canonical transformation [MECH] A transfor-of a contoured cam surface, a prescribed motion of the output link. { kam mekənizəm } mation which occurs among the coordinates and momenta describing the state of a classical dy-cam nose [MECH ENG] The high point of a cam, which in a reciprocating engine holds valves namical system and which leaves the form of Hamilton’s equations of motion unchanged.open or closed. { kam nōz } cam pawl [MECH ENG] A pawl which prevents a Also known as contact transformation. { kənänəkəl tranzfərmāshən }wheel from turning in one direction by a wedging action, while permitting it to rotate in the other cant file [DES ENG] A fine-tapered file with a triangular cross section, used for sharpening sawdirection. { kam pȯl } Campbell-Stokes recorder [ENG] A sunshine teeth. { kant fı̄l } cant hook [DES ENG] A lever with a hooklikerecorder in which the time scale is supplied by the motion of the sun and which has a spherical attachment at one end, used in lumbering. { kant hu̇k }lens that burns an image of the sun upon a specially prepared card. { ¦kaməl ¦stōks ri cantilever [ENG] 1. A beam or member securely fixed at one end and hanging free at the otherkȯrdər } camp ceiling [BUILD] A ceiling that is flat in the end. 2. In particular, in an atomic force micro- scope a very small beam that has a tip attachedcenter portion and sloping at the sides. { kamp sēliŋ } to its free end; the deflection of the beam is used 85