`
`IIIC’I‘IIII‘AIIY 0F
`SCIIIN’I‘I‘IC AMI
`’I‘IAIINIL I’I‘IIIRMS
`t IIIII'III I]IlitiIIII
`
` RPX-1010, p.1
`
`\‘M
`
`RPX-1010, p.1
`
`
`
`
`
`
`
`McGraw-llill
`IIIC’I‘IIINAIH' III“
`SCIENTIFIC AMI!
`TECHNICAL
`
`TERMS
`
`
`
`
`'I’dmrtll liclifiun
`
`
`
`§\'llil I'. I'alrker
`EDITOR lN CHIEF
`
`McGRAW-Hlll BOOK COMPANY
`
`New York
`St. Louis
`San Francisco
`
`Toronto
`
`Auckland
`Caracas
`
`Hamburg
`London
`Mexico
`Montreal
`
`Oklahoma City
`Paris
`Séo Paulo
`
`Sydney
`
`Bogota
`Colorado Springs
`Lisbon
`Madrid
`Milan
`New Delhi
`Panama
`San Juan
`
`Singapore
`Tokyo
`
`
`
`RPX-1010, p.2
`
`RPX-1010, p.2
`
`
`
`
`
`On the cover: Pattern produced from white light by a computer-generated
`diffraction plate containing 529 square apertures arranged in a 23 x 23 array.
`(R. B. Hoover, Marshall Space Flight Center)
`On the title pages: Aerial photograph of the Sinai Peninsula made by Gemini
`spacecraft. (NASA)
`
`Included in this Dictionary are definitions which have been published previously in the following
`Works: P'. B. Jordain, Condensed Computer Encyclopedia, Copyright © 1969 by McGraw-Hill, Inc.
`All rights reserved. J. Markus, Electronics and Nucleonics Dictionary, 4th ed., Copyright © 1960,
`1966, 1978 by McGraw-Hill, Inc. All rights reserved. J. Quick, Artists’ and Illustrators’ Encyclopedia,
`Copyright © 1969 by McGraw-Hill, Inc. All rights reserved. Blakiston’s Gould Medical Dictionary,
`3d ed., Copyright © 1956, 1972 by McGraw-Hill, Inc. All rights reserved. T. Baumeister and
`L. S. Marks, eds., Standard Handboohfar Mechanical Engineers, 7th ed., Copyright © 1958, 1967
`by McGraw-Hill, Inc. All rights reserved.
`In addition, material has been drawn from the following references: R. E. Huschke, Glossary of
`Meteorology, American Meteorological Society, 1959;_ U.5. Air Farce Glossary ofStandardized Terms,
`AF Manual 11—1, vol. 1, 1972; Communicatians-Electronics Terminology, AF Manual 11-1, vol. 3,
`1970; W. H. Allen, ed., Dictionary of Technical Terms for Aerospace Use, Ist ed., National Aero-
`nautics and Space Administration, 1965; J. M. Gilliland, Solar-Terrestrial Physics: A Glossary of
`Terms and Abbreviations, Royal Aircraft Establishment Technical Report 67158, 1967; Glossary of
`Air Traffic Control Terms, Federal Aviation Agency; A Glossary ofRange Terminology, White Sands
`Missile Range, New Mexico, National Bureau of Standards, AD 467-424; A DOD Glossary ofMapping,
`Charting and Geodetic Terms, lst ed., Department of Defense, 1967; P. W. Thrush, comp. and ed.,
`A Dictionary of Mining, Mineral, and Related Terms, Bureau of Mines, 1968; Nuclear Terms: A
`Glossary, 2d ed., Atomic Energy Commission; F. Casey, ed., Compilation of Terms in Information
`Sciences Technology, Federal Council for Science and Technology, 1970; Glossary of Stinfo Termi-
`nology, Office of Aerospace Research, U.S. Air Force, 1963; Naval Dictionary of Electronic, Tech—
`nical, and Imperative Terms, Bureau of Naval Personnel, 1962; ADP Glossary, Department of the
`Navy, NAVSO P-3097.
`
`McGRAW-HILL DICTIONARY OF SCIENTIFIC AND TECHNICAL TERMS,
`Fourth Edition
`Copyright © 1989, 1984, 1978, 1976, 1974 by McGraw—Hill, 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 be reproduced or distributed in any form or by any means, or stored
`in a data base or retrieval system, without the prior written permission of the publisher.
`
`1234567890
`
`DOW/DOW
`
`8954321098
`
`ISBN U-DT-UHSEWJ-‘l
`
`Library of Congress Cataloging-in-Publication Data
`
`McGraw-Hill dictionary of scientific and technical terms.
`
`1. Science—Dictionaries.
`1. Parker, Sybil P.
`Q123.M34
`1989
`ISBN 0-07—045270-9
`
`2. Technology—Dictionaries.
`
`503721
`
`88-13490
`
`For more information about other McGraw-Hill materials, call 1-800-2-MCGRAW in the
`United States. In other countries, call your nearest McGraw-Hill office.
`
`RPX-1010, p.3
`
`RPX-1010, p.3
`
`
`
`TOGG LE
`drive
`rock being force
`crushed
`
`
`
`Toggle mechanism used in a rock
`crusher; relatively small drive
`force causes large force to be
`applied to rock.
`
`TOLUENE—2,4—
`DIISOCYANATE
`CH3
`
`NCO
`
`NCO
`Structural formula.
`
`[METEOROL]
`A violent spring storm common in the
`mountains of Indonesia.
`{ to'fan }
`to-from indicator
`[NAV] An indicator that shows whether
`an aircraft is flying toward or away from an omnirange station.
`Also known as sense indicator.
`{ 'tii 'fram ,in-do,kad-or }
`toggle
`[ELECTR] To switch over to an alternate state, as in a
`flip—flop.
`[MECH ENG] A form of jointed mechanism for the
`amplification of forces.
`{ 'tag'ol }
`toggle bolt
`[DES ENG] A bolt having a nut with a pair of
`pivotal wings that close against a spring; wings open after
`emergence through a hole or passage in a thin or hollow wall
`to fasten the unit securely.
`{ 'tag-al ,bolt }
`[ELECTR] Condition of a flip—flop circuit
`toggle condition
`in which the internal state of the flip-flop changes from 0 to 1
`or from 1 to 0.
`{ 'tag-ol kan,dishran }
`toggle press
`[MECH ENG] A mechanical press in which a
`toggle mechanism actuates the slide.
`{ 'tag-el Ipres }
`[ELEC] A small switch that is operated by
`toggle switch
`manipulation of a projecting lever that is combined with a spring
`to provide a snap action for opening or closing a circuit quickly.
`[ELECTR] An electronically operated circuit that holds either
`of two states until changed.
`{ ‘t‘ag‘al ,swich }
`toise
`[GEOD] A unit of length equal to about 6.4 feet (1.95
`meters); used in early geodetic surveys.
`{ 'toiz }
`tokamak
`[PL PHYS] A device for confining a plasma within
`a toroidal chamber, which produces plasma temperatures,
`densities. and confinement times greater than that of any other
`such device; confinement is effected by a very strong externally
`applied toroidal field, plus a weaker poloidal field produced by
`a toroidally directed plasma current, and this current causes
`ohmic heating of the plasma.
`{ 'tak-a,mak }
`token
`[COMMUN] A unique grouping of bits that is transmitted
`as a unit in a communications network and used as a signal to
`notify stations in the network when they have control and are
`free to send information.
`[COMPUT SCI]
`1. A distinguishable
`unit in a sequence of characters. 2. A single byte that is used
`to represent a keyword in a programming language in order to
`conserve storage space.
`{ 'to-kon }
`tokenization
`[COMPUT SCI] The conversion of keywords of
`a programming language to tokens in order to conserve storage
`space.
`{ ,té‘kan'a'za-shon}
`token passing protocol
`[COMMUN] The assignment of data
`communications channels to units which communicate accord—
`ing to a fixed priority sequence.
`{ ‘to-kon :pas-irj 'prod-o,kol }
`token sharing network [COMMUN] A communications net—
`work in which all the stations are linked to a common bus and
`control is determined by a group of bits (token) that is passed
`along the bus from station to station.
`{ 'to-kon :sher-irj
`'net,work }
`CloHnNz-HCI
`[ORG CHEM]
`tolazoline hydrochloride
`Water—soluble white crystals, and melting at 173°C; used as a
`sympatholytic and vasodilator. Also known as priscol.
`{ tal'az~9,lén [hi-dro'klorjd }
`tolbutamide
`[PHARM] C12H13N203S A hypoglycemic drug
`effective when administered orally.
`{ tal'byud-9,mid }
`toleragen
`[IMMUNOL] A substance which,
`in appropriate
`dosages, produces a state of specific immunological tolerance
`in humans or animals.
`{ 'tal-a-ra‘jan }
`tolerance
`[DEs ENG] The permissible variations in the di—
`mensions of machine parts.
`[ENG] A permissible deviation
`from a specified value, expressed in actual values or more often
`as a percentage of the nominal value.
`[PHARM]
`1. The ability
`Of enduring or being less responsive to the influence of a drug
`or poison, particularly when acquired by continued use of the
`substance. 2. The allowable deviation from a standard, as the
`range of variation permitted for the content of a drug in one of
`its dosage forms.
`{ 'tal-e-rons }
`tolerance chart
`[DES ENG] A chart indicating graphically the
`sequence in which dimensions must be produced on a part so
`that the finished product will meet the prescribed tolerance
`limits.
`{ 'tal-o-rans ,chart }
`{ 'tal-a-rons Idos }
`tolerance dose See permissible dose.
`tolerance limits
`[DES ENG] The extreme values (upper and
`lower) that are permitted by the tolerance.
`{ 't'al-a-rons ,lim‘
`ats }
`tolerance unit
`
`[DEs ENG] A unit of length used to express
`
`|yii-not}
`[C6H3(CH3)NH2] Lightse ,[
`[ORG CHEM]
`ortho-tolidine
`tive, combustible white to reddish crystals soluble in al‘
`and ether, slightly soluble in water, melts at 130°C; used: ‘1
`anlytical reagent and a curing agent for urethane resins
`tho 't'al-a,dén }
`1. Charge made for a connection beyOnd
`toll
`[COMMUN]
`exchange boundary.
`2. Any part of telephone plant, circ ‘"
`or services for which toll charges are made.
`toll call
`[COMMUN] Telephone call to points beyond the ..
`within which telephone calls are covered by a flat monthly 1
`or are charged for on a message unit basis.
`toll center
`[COMMUN]
`A telephone central office w .‘
`trunks from end offices are joined to the long-distance 5
`and operators are present; it is a class—4 office.
`toll enrichment
`[NUCLEO] Aproposed arrangementwhe
`privately owned uranium could be enriched in uranium. 1:
`content in government facilities upon payment of a so
`charge by the owners.
`{ 'tol in‘rich'mant }
`Tollen’s aldehyde test
`[ANALY CHEM] A test that uses J
`ammoniacal solution of silver oxides to test for aldehydes
`ketones.
`{ 'tal-anz 'al-da,hid Itest }
`toll Iine
`[COMMUN] A telephone line or channel that conn
`different telephone exchanges.
`toll office
`[COMMUN] Atelephone central office which se J
`mainly to terminate and interconnect toll lines and various 1
`of trunks.
`{ 'tol ,of‘os }
`toll television See subscription television.
`an }
`toll terminal loss
`[COMMUN] The part of the overall trzll‘
`mission loss on a toll connection that is attributable to i
`facilities from the toll center through the tributary office ll
`and including the subscriber’s equipment.
`I10S }
`ot-toluamide See a—phenylacetamide.
`toluene
`[ORG CHEM] Cgl-ISCH3 A colorless, aromatic llqll
`derived from coal tar or from the catalytic reforming of p J
`leum naphthas; insoluble in water, soluble in alcohol and e a"
`boils at 11 1°C; used as a chemical intermediate, for explosi
`and in high—octane gasolines. Also known as methylbcnz-J
`phenylmethane; toluol.
`{ 'tal-yolw6n }
`toluene 2,4-diisocyanate
`[ORG CHEM]
`A liquid (at room temperature) with a sharp, pungent oq
`miscible with ether, acetone, and benzene; used to make
`lyurethane foams and other elastomers, and also as a pro
`cross—linking agent.
`{ 'tal‘y9,wén :ti‘l {fOr diji-so'si-anial } [
`para-toluenesulfonic acid
`[ORG CHEM]
`Toxic, colorless, combustible crystals soluble in water, dim
`hol, and ether; melts at 107°C; used in dyes and as a chct
`intermediate and organic catalyst.
`ik 'as-od }
`{ :tal-y9,w6n'thi.ol }
`toluenethiol See thiocresol.
`a—toluic acid See phenylacetic acid.
`meta-toluic acid
`[ORG CHEM] C6H4CH3COOH Whitl
`yellow, combustible crystals soluble in alcohol and ct
`slightly soluble in water, melts at 109°C; USCd 35 a Che'
`intermediate and base for insect repellants. Also know]
`meta-toluylic acid.
`{ [med'a ta'li'i-ik 'as-od }
`ortho-toluic acid
`[ORG CHEM]
`combustible crystals soluble in alcohol and chloroform, sllgi,
`soluble in water, melts at 104°C; used as a bacterloslulr
`known as ortho—toluylic acid.
`para-toluic acid
`[ORG CHEM] C6H4CH3COOH Tr'
`ent, combustible crystals soluble in alcohol and ether, s
`soluble in water, melts at 180°C; used in agricultural clicmi ‘]
`and as an animal feed supplement. Also known as [3‘
`toluylic acid.
`{ {par-9 to'lii-ik 'aS'ad }
`OL'tOllch aldehyde See phenylacetaldehyde.
`lal'dglhid }
`[ORG CHEM] CH3C5H4NH1 ACO“
`meta'tOIUldine
`colorless,
`toxic liquid soluble in alco
`soluble in water, boils at 203°C; used for dyes an
`intermediate.
`{ [med-o t9'lii‘9.den}
`ortho-toluidine
`[ORG CHEM] CH3CgH4NH2 A "fwhbl
`light-sensitive, combustible, toxic liquid soluble 101°C ust‘d .
`ether, very slightly soluble in water, bOils at 20
`
`
`
`RPX-1010, p.4
`
`1
`
`RPX-1010, p.4
`
`