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`San Francisco
`New York Chicago
`Lisbon London Madrid Mexico City
`Milan New Delhi
`San Juan Seoul Singapore Sydney Toronto
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`1
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`APPLE 1014
`
`

`
`I
`
`On the cover: Representation of a fullerene molecule with a noble gas atom trapped
`inside. At the Permian· Triassic sedimentary boundary the noble gases helium and argon
`have been found trapped inside fullerenes. They exhibit isotope ratios quite similar to
`those found in meterorites, suggesting that a fireball meteorite or asteroid exploded
`when it hit the Earth, causing major changes in the environment. (Image copyright©
`Dr. Luann Becker. Reproduced with pel'mission.)
`
`Over the six editions of the Dictionary, material has been drawn from the following references: G. M. Garrity
`et al., Taxonomic Outline of the Procaryo(es, Release 2, Springer-Verlag, January 2002; D. W. Linzey, Vertebrate
`Biology, McGraw-Hill, 2001; J. A. Pechenik, Biology of the Invertebrates, 4th ed., McGraw-Hill, 2000; U.S.
`Air Force Glossary of Standardized Terms, AF lvlanual 11-1, vol. 1, 1972; F. Casey, ed., Compilation a/Terms
`ill Information Sciences Technology, Federal Council for Science and Technology, 1970; Comm1111ications(cid:173)
`Electmnics Terminology, AF Manual 11-1, vol. 3, 1970; P. W. Thrush, comp. and ed., A Dictionary of Mining,
`Minernl, and Related Terms, Bureau of Mines, 1968; A DOD Glossary of Mapping, Charting and Geodetic
`Terms, Department of Defense, 1967; J. M. Gilliland, Solar-Terrestrial P/1ysics: A Glossary of Terms and
`Abbreviations, Royal Aircraft Establishment Technical Report 67158, 1967; W. H. Allen, ed., Dictionary of
`Technical Terms/or Aerospace Use, National Aeronautics mu! Space Administrntion, 1965; Glossary of Sti11fo
`Ter111i110/ogy, Office of Aerospace Research, U.S. Air Force, 1963; Naval Dictionary of Electronic, Technical,
`and !111pemtive Terms, Bureau of Naval Personnel, 1962; R. E. lluschkc, Glossary of i'l/eteorology, American
`Meteorological Society, 1959; ADP Glossary, Department of the Navy, NAVSO P-3097; Glossary of Air Traffic
`Control Terms, Federal Aviation Agency;/\. Glo.1·s01)' of Rauge Ter111i1wlogy, While Sands Missile Range, New
`Mexico, National Bureau of Standanls, AD 467-424; Nuclear Terms: A Glossa1y, 2d ed., Atomic Energy
`Commission.
`
`McGRAW-HILL DIC'flONARY OF SCIENTIFIC AND TECHNICAL TERMS,
`Sixth Edition
`Copyright © 2003, 1994, 1989, 1984, 1978, 1976, 1974 by Tl1e McGraw-Hill Companies, Inc. All rights
`reserved. Printed in the United States of America. Except as permitted under the United States Copyright Act
`of 1976, no part of this publication may I.Jc reproduced or distributed in any form or by any means, or stored
`in a database or retrieval system, without the prior written permission of the publisher.
`
`234567890
`
`DOW/DOW
`
`0876543
`
`ISBN 0-07-0,12313-X
`
`Library of Congress Cataloging·in·Publication Oata
`
`McGraw-Hill dictionary of scientific and technical terms--6lh ed.
`cm.
`p.
`ISBN 0-07-042313-X (alk. paper)
`1. Science--Dictionaries. ? .. Technology--Dictionaries.
`and technical terms.
`
`I. Title: Dictionary of scientific
`
`Ql23.Ml5
`503-dc21
`
`2002
`
`2002026436
`
`2
`
`

`
`534
`
`cycle stealing
`
`cyclic voltammetry
`
`[coMPUT sci] A technique for memory shar(cid:173)
`cycle stealing
`ing whereby a memory may serve two autonomous masters,
`commonly a central processing unit and an input-output channel
`or device controller, and in effect provide service to each simul(cid:173)
`taneously.
`( 'sf· k;:il ,stel-itJ }
`cycle stock
`[CHEM ENG] The unfinished product taken from
`a stage of a refinery process and recharged to the process at
`an earlier stage in the operation.
`( 'sT·bl ,stl\k}
`[oRGCHEM] C21H280 3 A viscous, brown liquid,
`cyclethrin
`soluble in organic solvents; used as an insecticide.
`[ sI'kle·
`thr;:in}
`[COMPUT scI] The shortest time elapsed between
`cycle time
`one store (or fetch) and the next store (or fetch) in the same
`memory unit. Also known as memory cycle.
`[PETRO ENG]
`In a drilling operation, the time needed for the pump to move the
`drilling fluid in a bore hole.
`[scITECH] The time required to
`carry out a sequence of activities repeated in each performance
`of an operation.
`( 'sT·k;:il ,tTm}
`cycle timer
`[ELECTR] A timer that opens or closes circuits
`according to a predetermined schedule.
`( 'sT·k;:il ,tTm·;:ir }
`cycle timing diagram
`[COMPUTSCI] A diagram showing the
`activity that occurs in each clock cycle of a computer during the
`execution of a machine-language instmction. { 'sI·k;:il :mn·itJ
`,dT·;i,gram }
`cyclic
`[scrTECH] 1. Pe1taining to some cycle. 2. Repeating
`itself in some manner in space or time.
`( 'sik·lik}
`[B!OCHEM] C 10H 12N50 6P An isomer
`cyclic adenylic acid
`of adenylic acid; crystal platelets with a melting point of219-
`220"C; a key regulator which acts to control the rate of a
`number of cellular processes in bacteria, most animals, and
`some higher plants. Abbreviated cAMP. Also known as
`adenosine 3',5'-eyclic monophosphate; adenosine 3',5'-cyclic
`phosphate; adenosine 3',5'-monophosphate; 3',5'-AMP; cyclic
`AMP.
`( 'sik·lik :ad·an:il·ik 'as·ad}
`cyclic amide
`[ORG CHEM] An amide arranged in a ring of
`carbon atoms.
`( 'sfk·lik 'a,mTd }
`cyclic AMP See cyclic adenylic acid. { 'sTk·lik :a:em:pe }
`cyclic AMP-dependent protein kinase
`[BIOCHEM] A ser(cid:173)
`ine/threonine protein kinase that phosphorylates a variety of
`substrates and regulates many important processes such as cell
`growth and differentiation and the flow of ions across the cell
`membrane. Also known as protein kinase A; PKA. { :sr·
`klik :a:em:pe di:pen·d;:int ,pro,ten 'kf,nas )
`[MOL mo]
`cyclic AMP-responsive element binding protein
`A deoxyribonucleic acid-binding
`transcription factor
`that
`becomes modified in response to an extracellular signal.
`Abbreviated CREB.
`( :s1·klik :a:em:pe ri:sptin·siv :el·a·m;:int
`:b111d·iu 'pro,ten J
`[ORG CHEM] A ring compound formed by
`cyclic anhydride
`the removal of water from a compound; an example is phthalic
`( 'sik·lik an'hI,drTd }
`anhydride.
`[CHEM ENG] A method
`cyclic catalytic reforming process
`for the production of low-Btu reformed gas consisting of the
`conversion of carbureted water-gas set~ by installing a bed of
`nickel catalyst in the superheater and using the carburetor as
`a combustion chamber and process steam superheater. Abbre(cid:173)
`{ 'sTk·lik :kad·;:i:licl-ik ri'for-mil) ,pras·
`viated CCR process.
`gs)
`[ANALY CHEM] An analytic
`cyclic chronopotentiometry
`electrochemical method in which instantaneous current reversal
`is imposed at the working electrode, and its potential is moni(cid:173)
`( 'sik·lik :kran·o·p;:i,ten·che'iim·:i·tre}
`tored with time.
`cyclic code
`[COMPUT sci] A code, such as a binary code,
`that changes only in one digit when going from one number
`to the number immediately following, and in that digit by only
`one unit.
`( 'sik·lik 'kod}
`cyclic coil See random coil.
`( 'sTk·lik 'koil)
`cyclic compound
`[ORG CHEM] A compound Lhat contains
`a ring of atoms. { 'sTk·lik 'kiim,paund )
`cyclic coordinate
`[MECH] A generalized coordinate on
`which the Lagrangian of a system does not depend explicitly.
`Also known as ignorable coordinate. { 'sTk·lik ko'ord·;:in·;:it}
`cyclic currents See mesh currents. { 'sik·lik :k;:ir·;:ints }
`cyclic curve
`[MATH] 1. A curve (such as a cycloid, cardioid,
`or epicycloid) generated by a point of a circle that rolls (without
`slipping) on a given curve. 2. The intersection of a quadric
`surface with a sphere. Also known as spherical cyclic curve.
`3. The stereographic projection of a spherical cyclic curve.
`Also known as plane cyclic curve.
`( 'sTk·lik 'k;:irv }
`
`[IND ENG] An element of an operation or
`cyclic element
`( 'srk·lik 'el·a·mant}
`process that occurs in each of its cycles.
`cyclic extension
`[MATH] A Galois extension whose Galois
`group is cyclic. { 'sTk·lik ik'sten·ch;in}
`In character recognition, a sys(cid:173)
`cyclic feeding
`[COM PUT SCI]
`tem employed by character readers in which each input docu(cid:173)
`ment is issued to the document transpmt in a predetermined
`and constant period of time. { 'sTk·lik 'red·i!J )
`cyclic GMP
`[BIOCHEM] A 3',5'-cyclic ester of guanosine
`monophosphate that is involved in vision transduction through
`its direct effects on Na• and Ca2+ channels in the plasma mem(cid:173)
`( /sT·klik Ue/em'pe}
`brane of rod cells.
`cyclic graph
`[MATH] A graph whose vertices correspond to
`the vertices of a regular polygon and whose edges correspond
`to the sides of the polygon.
`[ :sHdik 'graf }
`[MATH] A group that has an element a such
`cyclic group
`that any element in the group can be expressed in the form a'',
`[ 'sik·lik ,griip J
`where n is an integer.
`cyclic identity
`[MATH] The principle that the sum of any
`component of the Riemann-Christoffel tensor and two other
`components obtained from it by cyclic permutation of any three
`indices, while the fourth is held fixed, is zero.
`( 'sTk·likI,den·
`t;:id·e J
`cyclic ion See bridged ion. { 'sTk· lik 'T·;:in }
`[MATH] A left module over a ring A that
`cyclic left module
`has a member x such that any member of the module has the
`form ax, where a is a member of A.
`( :s1·klik ,left 'miij·al }
`cyclic magnetization
`[ELECTROMAG] A magnetizing force
`varying between two specific limits long enough so that the
`magnetic induction has the same value for corresponding points
`in successive cycles. { 'sTk·lik mag·na·ta'za·sh;:in }
`cyclic mining See conventional mining. { 'sTk·lik ,min·il) }
`cyclic nucleotide phosphodiesterase
`[B!OCHEM] Any of
`a group of enzymes that degrade cyclic nucleotides.
`[ :sTk·
`lik ,n!Hde·;:i,Ud ,fiis·fa·dT'es·t;:i,ras }
`cyclic permeability See normal permeability. { 'sik·lik ,par·
`me·;:i'biJ.::id·e J
`[MATH] A permutation of an ordered set
`cyclic permutation
`of symbols which sends the first to the second, the second to
`the third, ... , the last to the first. Also known as cycle.
`[ 's!k·lik p;ir·my;:i'ta·shan }
`[MATH] A polygon whose vertices are
`cyclic polygon
`located on a common circle.
`( :sHdik 'paH,gan }
`cyclic redundancy check
`[COMPUT sci] A block check
`character in which each bit is calculated by adding the first bit
`of a specified byte to the second bit of the next byte, and
`so forth, spiraling through the block. { 'slk·lik ri'dan·d;:in·
`se ,chek}
`[OCEANOGR] Salt removed from the sea as spray,
`cyclic salt
`hlown inland, and returned to its source by land drainage.
`{ 'sfk· lik 'solt )
`[GEOL] Deposition of various kinds
`cyclic sedimentation
`of sediment in a repeated regular sequence.
`( 'sTk·lik ,sed·a·
`m;:in'ta·sh;:in ]
`cyclic shift
`[ COiv!PUT SCI] A computer shift in which the
`digits dropped off at one end of a word are returned at the
`other end of the word. Also known as circuit shift; circular
`shift; end-around shift; nonarithmetic shift; ring shift.
`[ 'sTk·
`lik 'shift }
`[ COMPUT SC!] A computer storage device,
`cyclic storage
`such as a magnetic drum, whose storage medium is arranged
`in such a way that information can be read into or extracted
`from individual locations at only certain fixed times in a basic
`[ 'sTk· lik 'st6r·ij }
`cycle.
`cyclic testing
`[ENO] The repeated testing of a device or
`system at regular intervals to be assured of its reliability.
`( 'sik· lik 'test-il) }
`cyclic train
`[MECH ENG] A set of gears, such as an epicyclic
`gear system, in which one or more of the gear axes rotates
`[ 'sTk· lik 'tran }
`around a fixed axis.
`[COMPUT sc1] The automatic transfer of data
`cyclic transfer
`from some medium to memory or from memory to some
`( 'sTk·lik 'tranz·far }
`medium until all the data are read.
`cyclic twinning
`[CRYSTAL] Repeated twinning of three or
`more individuals in accordance with the same twinning law
`but without parallel twinning axes. { 'sTk·lik 'twin·il)}
`cyclic voltammetry
`[PHYS CHEM] An electrochemical tech-
`nique for studying variable potential at an electrode involving
`application of a triangular potential sweep, allowing one to
`
`I
`.. _,_--~~-~-·-*"""'"'·"""' """'.-"'""""""'"'"""'"""'"-*""~rw!!lil.lJ!,Wilfllll' •'1!li!"'*~#··GW\'J!ll:iffil1P:!!i\l@tlllMiliiiliir"~#l&ilijkij'ii\"ljO"~-··Ji!l~
`
`-··
`
`3
`
`

`
`396
`
`circle of Willis
`
`circular cylinder
`
`-~ '
`
`position and as its radius the probable error of the position;
`the percent of the probable error must be specified e1Tor; it is
`a circle within which a craft is considered to be located.
`[ 's;i1 ..
`k;il ;;iv ;;in's;irt·:m·te )
`[ANAT] A ring of arteries at the base of the
`circle of Willis
`{ 's;ir·k:il ::iv 'wil·;is )
`cerebrum.
`[MECH ENG] A shearing machine that cuts cir(cid:173)
`circle shear
`cular disks from a metal sheet rolling between the cutting
`wheels.
`{ 's~r· k;;il ,sher )
`[NAY] A chart with curves enabling a graphical
`circle sheet
`solution of a three-point problem rather than using a three-mm
`protractor.
`{ 's;;ir·k:il ,shet )
`circling approach area
`[NAY] The area in which aircraft
`circle to land under visual conditions after completing an instru(cid:173)
`ment approach.
`{ 's:wklil) ;i'priich ,er·e·;i )
`[ELECTROMAG) A
`See electric circuit.
`circuit
`[ELEC]
`complete wire, radio, or carrier communications channel.
`See cycle. { 's:ir·k:it ]
`[MATH)
`circuital field See rotational field.
`{ s::.:kyil·:id·Gl 'feld )
`circuit analyzer See volt-ohm-milliammeter.
`{ 's;ir·k::.t ,an·
`;i,llz·::.r )
`circuit board See printed circuit board.
`{ 's;ir·k::it ,bard)
`circuit breaker
`[ELEC] An electromagnetic device
`that
`opens a circuit automatically when the current exceeds a prcde(cid:173)
`tenninecl value.
`{ 's::ir·k:it ,brak·:ir )
`circuit capacity
`[COMMUN] Number of communications
`channels which can be handled by a given circuit at the same
`time.
`{ 's:;ir·k:it k;i'pas·;;id·c)
`circuit conditioning
`[ELEC..'TR] Test, analysis, engineering,
`and installation actions to upgrade a c01nmunications circuit
`to meet an operational requirement; includes the reduction of
`noise, the equalization of phase and level stability and frequency
`response, and the correction of impedance discontinuities, but
`does not include normal maintenance and repair activities.
`[ 's::ir-k::it k:m'dish·;i·nil) )
`circuit design
`[ELEC] The art of specifying the components
`and interconnections of an electrical network.
`{ 's;:ir· k;:it
`d::i'zin)
`[ELEC] A drawing, using standardized sym(cid:173)
`circuit diagram
`bols, of the arrangement and interconnections of the conductors
`and components of an electrical or electronic device or installa(cid:173)
`tion. Also known as schematic circuit diagram; wiling dia(cid:173)
`gram.
`[ 's::ir-k:it ,dI·:J,gram )
`circuit efficiency
`[ELECTR] Of an electron tube, the power
`delivered to a load at the output terminals of the output circuit
`at a desired frequency divided by the power delivered by the
`[ 's:ir(cid:173)
`electron stream to the output circuit at that frequency.
`k::it i'fish·:m·se)
`circuit element See component.
`( 's:ir·k:it :el·;i·m:int)
`circuit grade
`[COMMUN] A circuit rating defining the ability
`to carry information; grades include telegraph, voice, and
`{ 's:Jr·k:it ,grad )
`broad-band.
`circuit interrupter
`[ELEC] A device in a circuit breaker to
`remove energy from an arc in order to extinguish it.
`{ 's;ir·
`k::it ,in-t;;i,r:ip·t;ir l
`circuit loading
`[ELEC] Power drawn from a circuit by an
`electric measuring instrument, which may alter appreciably the
`quantity being measured.
`( 'sm·k;it ,!Od·ilJ )
`circuit noise
`[COMMUN]
`In telephone practice, the noise
`which is brought to the receiver electrically from a telephone
`system, excluding noise picked up acoustically by telephone
`transmitters.
`{ 's:ir·bt ,noiz }
`circuit noise level
`[COMMUN] Ratio of the circuit noise at
`that point to some arbitrary amount of circuit noise chosen as
`a reference; usually expressed in decibels above reference noise,
`signifying the reading of a circuit noise meter, or in adjusted
`decibels, signifying circuit noise meter reading adjusted to rep(cid:173)
`resent interfering effect under specified conditions.
`{ 's:ir· k::it
`,noiz ,lcv·:il )
`[ELECTR] Provision for automatically
`circuit protection
`preventing excess or dangerous temperatures in a conductor
`and limiting the amount of energy liberated when an electrical
`failure occurs.
`{ 's::ir·k;;it prn'tek·sh;in }
`circuit reliability
`[COMMUN] The percent of time a circuit
`was available to the user during a specified period of time.
`{ 's:ir·k:it ri,!I·:i'bil·::id·e)
`circuitron
`[ELECTR] Combination of active and passive
`components mounted in a single envelope like that used for
`
`CIRCUIT BREAKER
`
`Bulk oil circuit breaker for
`138-kilovolt application.
`
`CIRCUIT INTERRUPTER
`
`current out
`
`\
`
`flexible bn:iid
`
`Cross section of interrupter for a
`typical medium-voltage circuit
`breaker.
`
`tubes, to serve as one or more complete operating stages.
`{ 's:wky:i,trlin}
`circuitry
`[ELEC] The complete combination of circuits used
`in an electrical or electronic system or piece of equipment.
`{ 's:Jr·k;i·tre )
`circuit shift See cyclic shift.
`{ 's:ir·kdt ,shift )
`[COMMUN] 1. The method of providing
`circuit switching
`communication service through a switching facility, either from
`local users or from other switching facilities. 2. A method of
`transmitting messages through a communications network in
`which a path from the sender to the receiver of fixed bandwidth
`or speed is set up for the entire duration of a communication
`or call.
`{ 's:ir-k:it ,swich·ilJ )
`circuit testing
`[El.EC] The testing of electric circuits to
`determine and locate an open circuit, or a short circuit or
`leakage.
`{ 's:ir· k::it , tes ·ti!) }
`circuit theory
`[ELEC) The mathematical analysis of condi(cid:173)
`tions and relationships in an electric circuit. Also known as
`( 's:ir·k:it ,the·;i·re }
`electric circuit theory.
`[MATH] A determinant in which the
`circulant determinant
`elements of each row are the same as those of the previous
`row moved one place to the right, with the last element put
`[ 's::ir·ky:i·l:mt d:i't;ir·m;i·n:int}
`first.
`circulant matrix
`[MATH) A matrix in which the elements of
`each row are those of the previous row moved one place to
`the right.
`{ 's:ir·ky:i·l:int 'ma,triks }
`circular accelerator See circular particle accelerator.
`ky::i·l:ir ak'sel·;;i,rad·:ir)
`circular antenna
`[ELECTROMAG] A folded dipole that is
`bent into a circle, so the transmission line and the abutting
`folded ends m·e at opposite ends of a diameter.
`{ 's;ir·ky:i·l:Jr
`an 'ten-:i )
`[MATH) An argument that is not valid
`circular argument
`because it uses the theorem to be proved or a consequence of
`that theorem that is not proven.
`{ :s:ir·ky:i·lar 'ar-gya·m:Jnt)
`circular arc See arc.
`{ 's:ir· ky:J· l::ir 'ilrk )
`circular behavior
`[PSYCH] Behavior that stimulates similar
`behavior
`in another
`individual or group.
`{ 's:ir· ky:i· l:ir
`b::>'hl\v·y:ir }
`[ OPTrcs) The phenomenon in which
`circular birefringence
`an optically active substance transmits right circularly polarized
`light with a different velocity from left circularly polarized
`{ 's;;ir·ky:i·I;ir ,bI·r;i'frin-j:ms]
`light.
`circular buffering
`[COMPUT sct] A technique for receiving
`data in an input-output control system which uses a single
`buffer that appears to be organized in a circle, with data wrap(cid:173)
`ping around it.
`{ 's::ir·ky:i·l;:ir 'b;;if·:i·ril) )
`circular burner
`[ENG] A fuel burner having a round open(cid:173)
`ing.
`{ 's;ir·ky:i·l:ir 'b;;irn-::ir}
`circular channel
`[ENG] Continuous-length opening with
`circular cross section through which liquid or gas can be made
`{ 's::ir·ky:i·I;ir 'chaw::>! l
`to flow.
`pen-and-ink
`circular-chart
`recorder
`[ENG] Graphic
`recorder where measured values are drawn onto a rotating
`circular chart by the backward and forward movement of a
`pivoted pen actuated by the input signal (such as temperature,
`pressure, flow, or force) from an instrument transmitter.
`{ 's::ir·ky;i·br ,chiirt ri'kord·:ir)
`circular chromatography See radial chromatography.
`kyg·lar 1krO·m~ 1Uig·rd·fe}
`circular coal See eye coal.
`{ 's;;ir·ky::i·l:ir :kol )
`In eddy-current nondestructive
`circular coil
`[ELECrROMAG]
`tests, a type of test coil which surrounds an object.
`{ 's;ir(cid:173)
`ky:i· l;ir :!coil )
`[NUCLEO) A type of colliding-beam accel(cid:173)
`circular collider
`erator in which both beams are stored in large circular rings
`of magnets and are brought into collision repeatedly at several
`{ 's:ir·ky:J·lm k::i'IId·:ir )
`interaction points.
`circular cone
`[MATH] A cone whose base is a circle.
`{ 's:ir·ky::i·l:ir 'kon }
`[MATH] The lateral surface of a
`circular conical surface
`right circular cone.
`{ :s;ir·ky;;i·l;ir :kan·;;i·k:il 's:ir·fas)
`circular current
`[Et.EC) An electric current moving in a cir(cid:173)
`cular path.
`{ 's:ir·ky:i·l:ir 'k:ir-:Jnt)
`circular cutter
`[MECH ENG] A rotating blade with a square or
`knife edge used to slit or shear metal.
`{ 's:Jr·ky:J·l::ir 'k:Jd·:ir)
`circular cylinder LMATH] A solid bounded by two parallel
`planes and a cylindrical surface whose intersections with planes
`
`{ 's:ir·
`
`I
`
`{ 'sar·
`
`4
`
`

`
`circular deoxyribonucleic acid
`
`circulate~and-weight method
`
`397
`
`perpendicular to the straight lines fonning the surface are cir(cid:173)
`cles. { 's:ir·ky:i·l:ir 'sil·:in·d:ir)
`[B!OCHEM] A single- or
`circular deoxyribonucleic acid
`double-stranded ring of deoxyribonucleic acid found in certain
`bacteriophages and in human wart virus. Also known as ring
`deoxyribonucleic acid.
`[MOL mo] A deoxyribonucleic acid
`molecule that has no free 5' or 3' ends; characteristic of prokary(cid:173)
`otes but also found in mitochondria, chloroplasts, and some
`viral genomes.
`[ 's:ir·ky:i·l:ir de:iik·sc:rr,bo:nu:kle·ik 'as·:id )
`circular dichroism
`[OPTICS] A change from planar to ellip(cid:173)
`tic polarization when an initially plane-polarized light wave
`u·averses an optically active medium. Abbreviated CD.
`[ 's:ir·ky:i·l:ir 'dT·lcr6,iz·:im)
`circular electric wave
`[ELECTROMAG] A transverse electric
`wave for which the lines of electric force form concentric
`[ 's:ir·ky:i·br i:lek·trik 'wav )
`circles.
`circular error
`[ORD] 1. A bombing error measured by the
`radial distance of a point of bomb impact, or mean point of
`impact, from the center of the target, excluding gross errors.
`2. With an airburst atomic bomb, the bombing error measured
`from the point on the ground immediately below the bomb
`burst to the desired ground zero.
`{ 's:ir·ky:i·l:ir 'er·:ir)
`circular-error average
`[ORD] The bombing error in a given
`bombing attack, expressed as the average radial distance of the
`bomb impacts, or mean points of impact, from the center of
`the target
`[ 's:il"lcyo·l:ir :er·:ir 'av·rnj ]
`circular error probable See circle of equal probability. { 'sor·
`ky:i·l:ir :er·;ir 'prab·:i·b::il )
`circular file
`[coMPUT sci] An organized collection of
`records, generally with a high turnover, in which new records
`are inserted by replacing the oldest records.
`[ 's:ir·ky;i·l:ir
`'fil}
`[FL MECH] A method to determine
`circular flow method
`viscosities of Newto.nian fluids by measuring the torque from
`viscous drag of sample material between a closely spaced rotat(cid:173)
`,f!O
`ing plate-stationary cone assembly.
`[ 's:ir·ky:i·l:ir
`'meth·;id}
`[DES ENG] A round or disk-shaped tool
`circular form tool
`with the cutting edge on the periphery.
`[ 's:ir·ky:i·lor ,l'orm
`,tUl }
`circular functions See trigonometric functions.
`'fal)k·sh:inz J
`[MATH] A curve that lies on a right circular
`circular helix
`cylinder and intersects all the elements of the cylinder at the
`[ 's:ir·ky:i·l:ir 'he,liks l
`same angle.
`circular horn
`[ELECTROMAG] A circular-waveguide section
`that flares outward into the shape of a horn, to serve as a feed
`for a microwave reflector or lens.
`[ 's:ir·kyg·ior 'horn)
`[MECH] The area of a circle I inch (25.4 milli(cid:173)
`circular inch
`meters) in diameter. { 's:ir·ky:i·l:ir 'inch )
`circular magnetic wave
`[ELECTROMAG] A transverse mag(cid:173)
`netic wave for which the lines of magnetic force form concentric
`circles.
`[ 's;ir·ky:i·lm mag'ned·ik 'wav )
`circular magnetostriction See Wiedemann effect.
`l:ir mag'ned·:i,strik·sh;in )
`circular mil
`[MECII] A unit equal to the area of a circle
`whose diameter is l mil (0.001 inch); used chiefly in specilying
`cross-sectional areas of round conductors. Abbreviated cir
`[ 's;:ir·ky:i·br 'mil]
`mil.
`[MECH] 1. Motion of a particle in a circular
`circular motion
`path. 2. Motion of a rigid body in which all its pa1ticles move
`in circles about a common axis, fixed with respect to the body,
`[ 's:ir·kya·l;:ir 'mo·shan }
`with a common angular veiocity.
`circular nomograph
`[MATH] A chart with concentric circu-
`lar scales for three variables, laid out so that any straight line
`passes through values of the variables satisfying a given equa(cid:173)
`[ 's:ir-ky;:i·l:ir 'no·m:i,graf]
`tion.
`circular orbit
`[ASTRON] An orbit comprising a complete
`( 's:ir-ky:i·lar
`constant-altitude revolution around the earth.
`'6r·bot l
`[ANALY CHEM] A paper
`circular paper chromatography
`chromatographic technique in which migration from a spot in
`the sheet takes place in 360° so that zones separate as a series
`of concentric rings.
`( 'sar-lcy:i·l:ir 'pa·p:ir ,kro·mg'ttig·ro·fe ]
`circular particle accelerator
`[NUCLEO] A particle accelera-
`tor which utilizes a magnetic field to bend charged-particle
`orbits and confine the extent of particle motion. Also known
`'pard·:i·k:il ak'sel·
`as circular accelerator. { 's:ir·kyo·l:ir
`a,rad·:ir)
`
`{ 's:ir·kyg·lm
`
`[ 's:ir· ky:i·
`
`[MATH] An arrangement of objects
`circular permutation
`around a circle.
`[ :sm·ky;:i·l;:ir ,po1"myo'Ui·sh;:in )
`circular pitch
`[DES ENG] The linear measure in inches along
`the pitch circle of a gear between corresponding points of
`adjacent teeth.
`[ 's:ir· ky:i· l:ir 'pich }
`circular plane
`[DES ENG] A plane that can be adjusted for
`convex or concave surfaces.
`[ 'sor·kya·l:ir 'plan )
`[MATH] A point on a surface at which the
`circular point
`normal curvature is the same in all directions.
`( 's:ir·ky:i·
`l::ir 'point l
`In projective geometty, one
`circular point at infinity
`[MATH]
`of two points nt which every circle intersects the ideal line.
`[ :sgr·ky:i·br :point at in'fin·od·e )
`circular polarization
`[PHYS] Attribute of a transverse wave
`(either of electromagnetic radiation, or in an elastic medium)
`whose electric or displacement vector is of constant amplitude
`and, at a fixed point in space, rotates in a plane perpendicular
`to the propagation direction with constant angular velocity.
`[ 's:ir·ky:i·br ,po·lo·r:i'za·sh:in )
`circular polarized loop vee
`[ELECTROMAG] Airborne com(cid:173)
`munications antenna with an omnidirectional radiation pattern
`to provide optimum near-horizon communications coverage.
`[ 's:ir·ky:i·l:ir 'po·l;;i,rTzd '!Up ,ve)
`circular polling
`[COMMUN] A form of polling in which each
`terminal is interrogated exactly once in every pass, regardless
`[ 's;:ir·ky:i·J;;ir 'pol·ilJ j
`of its level of activity.
`circular reference
`[ COMPUT sci] A situation created by a
`programming error in which two or more entities each refer to
`the other so that the execution of the program is carried on
`endlessly with no resolution.
`[ 's:ir·ky:i·l:ir 'ref·r:ins}
`circular saw
`[MECH ENG] Any of several power tools for
`cutting wood or metal, having a thin steel disk with a toothed
`[ 'sgr· kya· l;;ir 'so )
`edge that rotates on a spindle.
`circular scanning
`[ENG] Radar scanning in which the direc(cid:173)
`tion of maximum radiation describes a right circular cone.
`[ 's:ir·ky:i·l:ir 'skan·ilJ )
`circular screen
`[GRAPHICS] A circular halftone screen
`designed to permit adjustments for correct angles for halftone
`color photography without disturbing the copy.
`[ 'sor·ky:i·
`l:ir 'slcren ]
`[MATH] Portion of circle cut off from the
`circular segment
`main body ol' the circle by a straight line (chord) through the
`circle.
`[ 's:ir·ky;i·l:ir 'seg·m:int ]
`circular shaft
`[MIN ENG] A shaft excavated in a round shape.
`[ 's:ir· ky::l'l:ir 'shaft )
`circular shift See cyclic shift.
`[ 'sor·ky;l'l;ir 'shift )
`circular slide rule
`[MATH] A slide rule in a circular form
`whose advantages over a straight slide rule are its precision,
`because it is equivalent to a straight slide rule many times
`longer than the circular slide rule's diameter, and ease of multi(cid:173)
`plication, because the scale is continuous.
`[ 's;ir· kya· l:ir
`'slTd ,rUl )
`[ENG} A metal timber connector fitted with
`circular spike
`a circular series of sharp teeth that dig into the wood, preventing
`lateral motion, as a bolt is tightened through the wood and the
`[ 'sgr·ky:i·l;ir 'spTk)
`spike.
`[ELECTR] The use of electronic
`circular sweep generation
`circuits to provide voltage or current which causes an electron
`beam in a device such as a cathode-ray tube lo move in a
`circular deflection path at constant speed.
`[ 's;ir· ky:i · l:ir 'swep
`,jen·:i,ra·sh:in )
`[MECH] At any specific distance from the
`circular velocity
`primary, the orbital velocity required to maintain a constanl(cid:173)
`[ 's:if'lcy:i·hr v:i'ltis·od·e)
`radius orbit.
`circular vortex
`[METEOROL] An atmospheric flow in paral(cid:173)
`lel planes in which streamlines and other isopleths are concen(cid:173)
`tric circles about a common axis; an atmospheric model of
`easterly and westerly winds is a circular vortex about the earth's
`polar axis.
`[ 's::ir·ky:i·l;ir 'v6r,teks )
`circular wait See mutual deadlock.
`[ 's;ir·ky:i·l:ir 'wat)
`circular waveguide
`[ELECTROMAG] A waveguide whose
`cross-sectional area is circular.
`[ 's:ir-ky:i·l::ir 'wav,gTd )
`circular word
`[MATH] A sequence of elements arranged
`[ :s:ir·ky8·lm· 'w;ird)
`clockwise around a circle.
`circulate-and-weight method
`[PETRO ENG] During drilling
`operations, a method of controlling well pressure in which
`circulation is begun immediately and mud weight is increased
`gradually on a predetermined schedule. Also known as con(cid:173)
`current method.
`[ :s:ir·ky:i,lat ;in :wat ,meth·;id )
`
`CIRCULAR
`DEOXYRIBONUCLEIC
`ACID
`
`Electron microg1·aph of circular
`deoxyribonucleic acid extracted
`from the human wart virus.
`(Courtesy of' E. A. C. Follett)
`
`CIRCULAR NOMOGRAPH
`
`1ao·
`
`cllamplc:
`
`0:;;; 30•
`r!i::::: 315°
`cut U ut2.l
`
`Circular nomograph which results
`from a trigonometric equation
`expressed in the form of a
`determinant.
`
`CIRCULAR SAW
`
`miter
`gaze
`
`rigid·typc splitter
`mounted gu::ird
`
`rubber cord
`
`cabinet
`
`Bench circular saw with tilting
`arbor is used for parting or
`slotting and can make cuts as long
`as working space permits. (Delta)
`
`CIRCULAR SPll<E
`
`An example of a circular spike.
`
`5