DICTIONARY OF AUTOMOTIVE TERMS (A - E)
A: Abbreviation or symbol for absolute temperature, absorption
coefficient, acceleration, adenine, ampere, amplitude, angular
acceleration, area, attenuation coefficient, fine-structure
constant, helium nucleus, Helmhotz free energy, magnetic vector
potential, relative atomic mass, a stereoisomer of a sugar,
substitution on a carbon atom next to one common to two condensed
aromatic nuclei, substitution on the carbon atom next to the
hetero-atom in ahetero-cyclic compound, and substitution on the
carbon atom of a chain next to the functional group. A-2 tire: A
term used for tire sizes 16.00 and larger in nominal cross section.
Also called earthmover or off-the-road tire. AA: Abbreviation for
"Automobile Association" a term used in Great Britain. aa: A term
of Hawaiian origin for lava flows with a rough, jagged surface.
AAA: Acronym for "American Automobile Association" or "Alberta
Automobile Association." AABM: Acronym for "Association of American
Battery Manufacturers, Inc." AAE: Acronym for "Association of
Automotive Employers" (Poland).
AAIA: Acronym for "Automotive Aftermarket Industry Association".
AALA: Acronym for "American Automobile Labelling Act." aalenian:
The oldest stage of the Middle-Jurassic. AAM: Acronym for "Alliance
of Automobile Manufacturers". AAP: Acronym for "auxiliary
acceleration pump". A arm:See A-arm
A-arm: A suspension linkage formed in the shape of an "A" or "V"
found commonly on the front suspension. The sides of the two legs
of the A-arm are connected to the chassis by rubber bushings and
the peak of the A-arm is attached to the wheel assembly. In this
way, the wheel can freely move up and down. Sometimes there is an
upper A-arm, a lower A-arm, or both upper and lower A-arms. The
British call it a "wishbone."Also see double wishbone
A-arm suspension:See double wishbone
AAS:
Acronym for "air aspirator system". abacus: [1] The uppermost
part of a column capital or pilaster, on which the architrave
rests. [2] A bead frame. Used as an arithmetic calculating aid.
abampere: A unit of electric current in the CGS electromagnetic
system of units. One abampere equals 10A. abamurus: A supporting
wall or buttress, built to add strength to another wall.
abandonment: A voluntary surrender of legal rights or title to a
mining claim. abatjour: An opening to admit light and generally to
deflect it downwards; a skylight. abaxial: Rays of light which do
not coincide with the optical axis of a lens system. ABC: [1]
Acronym for "aerial bunched conductors" [2] Acronym for "automatic
beam control". ABDC: Acronym for after bottom dead center. A term
used in timing the relation of the spark and the crankshaft. Abel
flashpoint apparatus:
A petroleum-testing apparatus for determining the flash-point.
Abelian group: A group in which the group operation is commutative.
It is important in the study of rings and vector spaces.
aberration: [1] An apparent change of position of a heavenly body,
due to the speed of light having a finite ratio to the relative
velocity of the source and the observer. [2] In an image-forming
system, e.g., an optical or electronic lens, failure to produce a
true image, e.g., a point object as a point image. Geometrical
aberrations include spherical aberration, coma, astigmatism,
curvature of the field, and distortion.See chromatic aberration
abhesive: A substance which prevents two materials sticking
together, e.g., Teflon on frying pans. ability:See climbing ability
cold cranking ability
ABL: Acronym for "atmospheric boundary layer" panel. ablation:
[1] Any one of the processes by which snow and ice are lost from a
glacier, mainly by melting and evaporation (sublimation). [2]
Removal of surface layers of a meteorite and tektites during
flight. ablative polymer: A material which degrades controllably in
an aggressive environment, especially on re-entry space-craft.
Extreme temperatures are reached on heat shield, so it is protected
with ablation shield made of e.g., silicone polymer. The same
principle is used in intumescent paints for fire
resistance. Abney law: A rule stating that if a spectral color
is desaturated by the addition of white light, and if its wave
length is less than 570 nm, its hue then moves towards the red end
of the spectrum, while if the wavelength is more than 570 nm its
hue moves towards the blue. Abney level: Hand-held instrument in
which angles of steep sights are measured while simultaneously
viewing a spirit-level bubble. Abney mounting: A form of mounting
for a concave diffraction grating, in which the eyepiece (or
photographic plate holder) is fixed at the center of curvature of
the grating and the slit can move around the circumference of the
Rowland circle, to bring different orders of spectrum into view.
abnormal glow discharge: A discharge carrying current in excess of
that which is required to cover the cathode completely with visible
radiation. abnormal reflection: Reflection from the ionosphere of a
radio wave whose frequency is greater than the critical frequency.
aboard:See lighter aboard ship
aboard ship:See lighter aboard ship
A-bomb:See atomic bomb
A bone:
Nickname for a Ford Model "A". abort: To terminate a vehicle's
flight either by failure or deliberate action to prevent dangerous
consequences; if manned, a predetermined sequence of events is
followed to ensure the safety of the crew. ABPV: Acronym for "air
bypass valve". abradant: A substance, usually in powdered form,
used for grinding.Also see abrasive
abrade: To scratch or tear away two surfaces in contact by
relative motion. Abram's law: A rule that the ratio of water to
cement for chemical action to impart strength to concrete is
0.85:1. abrasion: [1] Wearing or rubbing away some surface because
of friction. [2] Mechanical wearing away of rocks by rubbing during
movement. abrasion hardness: Resistance to abrasive wear, under
specified conditions, of metal or mineral. abrasive: A hard grit
used for sanding or grinding. It is usually in powdered form, used
for the removal of material by scratching and grinding, e.g.,
silicon carbide powder (carborundum).Also see bonded abrasive
coated abrasive non-woven abrasive
abrasive blast cleaning: A method for preparing steel for
painting whereby abrasive particles, e.g., copper slag, are
projected under pressure through a nozzle. Very effective in
removing rust and mill scale, leaving an anchor pattern (a pattern
of minute projections) on the substrate affording good paint
adhesion. abrasive cleaner: A cleanser with some hard grit used to
remove the grime and oils from a surface. abrasive disc: A circular
plate (often made of plastic with hard grit embedded into it) used
for grinding or sanding.
abrasive paper: Sandpaper (a paper upon which sand or hard grit
has been glued) used for sanding or grinding. abrasive wear: A
mechanism of wear due to the presence in one or both surfaces of
hard particles (e.g., carbide in steels), or to hard particles
trapped between them. A/B roll editing: Video editing using two
source players (A and B) enabling dubbing from both. Necessary if
scenes are to be superimposed. A/B roll printing: A method of film
printing with alternate scenes assembled in two rolls, each having
black spacing equivalent in length to the omitted scene; double
printing from the two allows the inclusion of fade and dissolve
effects and avoids visible splice marks between scenes in 16 mm
printing.
ABS: [1] Acronym for "anti-lock brakes. The acronym ABS comes
from the German anti blockier system. [2] Acronym for
"acylonitrile-butadiene-styrene."Also see copolymer
abscissa: For rectilineal axes of coordinates, the distance of a
point from the axis of ordinates measured in a direction parallel
to the axis of abscissae, which is usually horizontal. The sign
convention is that measurements to the right from the axis of
ordinates are positive, measurements to the left negative.
absolute: A conic (a quadric in three dimensions) formed by the
assemblage of the points at infinity on a line (in general two
points). Its form determines the metrical properties of the
geometrical system being operated. Thus in Euclidean geometry, the
absolute is the degenerate conic comprising the line at infinity
taken twice, while in non-Euclidean geometry, the absolute is
either a real conic (hyperbolic geometry) or an imaginary conic
(elliptic geometry).Also see manifold absolute pressure sensor POA
suction throttling valve
absolute address: A computer code designation of a specific
memory location as determined by the hardware. absolute age: The
geological age of a fossil, mineral, rock or event, generally given
in years. absolute ampere: The standard MKS unit of electric
current; replaced the international ampere in 1948.
absolute ceiling: The height at which the rate of climb of an
aircraft, in standard atmosphere, would be zero; the maximum height
attainable under standard conditions. absolute electrometer: A
high-grade attracted-disk electrometer in which an absolute
measurement of potential can be made by weighing the attraction
between two charged disks against gravity. absolute filter: A
filter which removes most particulate matter from gases. absolute
humidity: The mass (actual amount) of water vapor present in a unit
of volume of moist air. absolute instrument: An instrument which
measures a quantity directly in absolute units, without the
necessity for previous calibration. absolute permeability:See
permeability
absolute pressure: Pressure measured from a starting point of
zero in perfect vacuum. When measured by the absolute pressure
scale, atmospheric pressure is 14.7 psi or 29.92 inches of mercury
(in-Hg).Also see manifold absolute pressure sensor
absolute pressure sensor:See manifold absolute pressure sensor
barometric absolute pressure sensor
absolute reaction rate: The reaction rate determined from
statistical thermodynamics; uses the assumption of the theory of
absolute reaction rates that the rate of a
chemical reaction is governed by the rate of crossing an energy
barrier or of forming an activated complex. absolute temperature:
Temperature measured with respect to absolute zero, i.e., the zero
of the kelvin thermodynamic scale of temperature, a scale which
cannot take negative values. absolute temperature scale: Also
called the absolute scale temperature as measured on a scale in
which the hypothetical lowest limit of physical temperature is
assigned the value zero. The Kelvin scale is an example of the
absolute temperature scale. absolute units: Units derived directly
from the fundamental units of a system and not based on arbitrary
numerical definitions. The differences between absolute and
international units were small; both are now superseded by the
definitions of SI units. absolute wavemeter: A wavemeter in which
the frequency of the injected radio-frequency signal is by
calculation of physical properties (circuit elements or dimensions)
of a resonant circuit line or cavity. absolute weight: The weight
(or mass) of a body in a vacuum. absolute zero: The point at which
there is a total absence of heat, minus 459.67F (-273.15C).
absorbance: [1] The logarithm of the ratio of the intensity of
light incident on a sample to that transmitted by it. It is usually
directly proportional to the concentration of the absorbing
substance in a solution.
[2] The capacity of materials such as textile fibers and paper
to absorb liquids. absorbed dose: Quantity of energy imparted by
ionizing radiation to a unit mass of biological tissue. Unit is the
gray. absorbent: Substance with the ability to take up or absorb
another substance. absorber: Any material which converts energy of
radiation or particles into another form, generally heat. Energy
transmitted is not absorbed. Scattered energy is often classed with
absorbed energy.Also see direct-acting shock impact absorber
absorber lever-type shock double-tube shock absorber absorber
monotube shock friction shock absorber absorber self-levelling
shock gas shock absorber absorber shock absorber single-tube shock
absorber. telescopic shock absorber UV absorber
air shock absorber arc absorber adjustable shock absorbers
damper
absorber rod:See control rod
absorber tower:See shock absorber tower
absorbing:See energy absorbing steering column energy absorbing
bumper
absorbing bumper:See energy absorbing bumper
absorbing material: Any medium used for absorbing energy from
radiation of any type.
absorbing steering:See energy absorbing steering column
absorbing steering column:See energy absorbing steering
column
absorptance: A measure of the ability of a body to absorb
radiation; the ratio of the radiant flux absorbed by the body to
that incident on the body. absorption: The use of reagents to
remove unwanted antibodies or antigens from a mixture.Also see
acoustic absorption air absorption atmospheric absorption sound
absorption
absorption band: A dark gap in the continuous spectrum of white
light transmitted by a substance which exhibits selective
absorption. absorption capacitor: A capacitor connected across a
spark gap to damp the discharge. absorption coefficient: [1] The
volume of gas, measured at stp, dissolved by unit volume of a
liquid under normal pressure (i.e., one atmosphere). [2] The
fraction of the energy which is absorbed. [3] The reduction of
amplitude, for a beam of radiation or other wave system incident on
a discontinuity in the medium through which it is propagated, or in
the path along which it is transmitted. [4] In a medium, the
natural logarithm of the ratio of incident and emergent energy or
amplitude for a beam of radiation passing through unit thickness of
a medium.Also see acoustic absorption coefficient
absorption discontinuity:See absorption edge
absorption dynamometer: A dynamometer which absorbs and
dissipates the power which it measures, e.g., the ordinary rope
brake and the Froude hydraulic brake. absorption edge: The
wavelength at which there is an abrupt discontinuity in the
intensity of an absorption spectrum for electromagnetic waves,
giving the appearance of a sharp edge in its photograph. The
transition is due to one particular energy-dissipating process.
absorption factor:See acoustic absorption factor
absorption hygrometer: An instrument by which the quantity of
water vapor in air may be measured. absorption inductor:See
interphase transformer
absorption lines: Dark lines in a continuous spectrum caused by
absorption by a gaseous element. The positions (i.e., wavelengths)
of the dark absorption lines are identical to those of the bright
lines given by the same element in emission. absorption nebula:See
dark nebula
absorption plant: Plant where oils are removed from natural gas
by absorption in suitable oil. absorption refrigerator:
[1] A plant in which ammonia is continuously evaporated from an
aqueous solution under pressure, condensed, allowed to evaporate,
and then reabsorbed. [2] A refrigerator which creates low
temperatures by using the cooling effect formed when a refrigerant
is absorbed by chemical substance. absorption spectrum: The system
of absorption bands or lines seen when a selectively absorbing
substance is placed between a source of white light and a
spectroscope. absorption wavemeter: A wavemeter which depends on a
resonance absorption in a tuned circuit, constructed with very
stable inductance and capacitance. absorptive power:See
absorptance
absorptivity:See absorptance
ABS override button: A button or switch which disengages the
automatic anti-lock braking system so that the driver can operate
the brakes himself. ABS relay valve: An electrically controlled
valve which modulates the air pressure in the ABS. abundance:See
relative abundance frequency
abundance ratio: For a naturally occurring element, the
proportion or percentage of one isotope to the total. abundant
number:
A natural number for which the sum of the proper factors is
greater than the number itself, e.g., 18 is abundant since
1+2+3+6+9>18. Compare deficient number and perfect number. abut:
The action of two gear teeth making contact. abutment: [1] A part
which stops the motion of another part from proceeding any farther.
[2] A cement raised shoulder secured to the side of the road to
prevent a vehicle from going over the edge. [3] The contact made
between opposing teeth of two gears. abutment load: In stopping or
other deep-level excavation, weight transferred to the adjacent
solid rock by unsupported roof. abutting edge: The side or edge of
a panel which joins another panel. abutting joint: a timber joint
whose plane is at right angles to the fibers, the fibers of both
joining pieces being in the same straight line. ABV: Acronym for
"air bypass valve". abyssal: term describing the ocean floor
environment between ca4000 and 6000 m. abyssal deposits: Pelagic
marine sediments, accumulating in depths of more than 2000 m
including, with increasing depth, calcareous oozes, siliceous oozes
and red clay (500 m).
abyssal plain: a flat region of the deep ocean floor with a
slope of less than 1:1000. abyssopelagic: relating to the open
waters of the abyssal zone. A/C: [1] An abbreviation for air
conditioning or air conditioner. [2] An abbreviation for "across
corners" which indicates the distance on a nut (for instance) from
one corner to the opposite corner rather than the distance from one
flat surface (A/F) to the opposite (which would be the size of
wrench needed to install or remove the nut). The purpose of the A/C
dimension is to know how large a hole might be needed to insert a
recessed nut. AC: [1] A vehicle brand of which the 1925-48 models
are classic cars. [2] Acronym for "alternating current." [3]
Acronym for "air conditioning" or "air conditioner." [4] Symbol for
actinium [5] The transformation temperature on heating of the phase
changes of iron or steel, subscripts indicating the designated
change, e.g., Ac1 is the eutectoid (723C) and Ac3 the
ferrite/austenite phase boundary. AC-3: Trade name for the digital
audio coding used in 35 mm motion picture film to provide
six-channel surround sound. It uses data blocks recorded optically
between the perforations, leaving room for a conventional
soundtrack. It is also suitable for multi-channel TV audio, as well
as video software and home cinema. AC Ace: A vehicle brand of which
the 1954-61 Ace models are milestone cars.
AC Aceca: (pronounced ah-SEEK-uh) A vehicle brand of which the
1955-61 Aceca models are milestone cars.
acanthite: An ore of silver, Ag2S, crystallizing in the
monoclinic system. ACAP: Acronym for "Associao do comrcio
automovvel de Portugal". ac balancer: An arrangement of
transformers or reactors used to equalize the voltages between the
wires of a multiple-wire system. Also called static balancer. ac
bias: A high-frequency signal applied to a magnetic tape recording
head along with the signal to be recorded. This stabilizes magnetic
saturation and improves frequency response, at the same time
reducing noise and distortion. The bias signal frequency has to be
many times the highest recording frequency. AC Buckland: A vehicle
brand of which the 1949 Buckland Open Tourer is a milestone
car.
ac-boundary layer:See stokes layer
acc:
Abbreviation for "accessories." ACC: [1] Acronym for "Automatic
Cruise Control." [2] A term found on a cruise control switch which
indicates the direction the switch needs to be moved to increase
the speed (accelerate) of the vehicle. ACCC: Acronym for "air
conditioner clutch compressor" signal. accelerate: [1] To increase
the speed of a vehicle. Opposite of decelerate. [2] To accelerate
an adhesive is to speed up a chemical reaction or a curing process.
For example, you can speed up the drying time of an adhesive or
sealer by increasing the temperature. Also, by adding a chemical
curing agent, or accelerator, to a base compound. accelerated aging
test: A stability test for cables using twice normal working
voltage. It is claimed this give quick results that correlate with
service records. accelerated fatigue test: Test which applies a
cyclic loading schedule, which can be of varying frequency and/or
amplitude, to a machine or component simulating its loading in
service, but at a higher rate, to determine its safe fatigue life
before it is reached in service. accelerate-stop distance: The
total distance, under specified conditions, in which an aircraft
can be brought to rest after accelerating to critical speed for an
engine failure at take-off. accelerating chain: The section of an
electron beam tube or system, e.g., cathode-ray tube or electron
microscope, in which electrons are accelerated by voltages on
accelerating electrodes. Also used in particle accelerators.
accelerating electrode: An electrode in a thermionic valve or
cathode-ray tube maintained at a high positive potential with
respect to the electron source. It accelerates electrons in their
flight to the anode but does not collect a high proportion of them.
accelerating machine:See accelerator
accelerating potential: The potential applied to an electrode to
accelerate electrons from a cathode. accelerating-well ports: These
ports prevent momentary leanness during the period that occurs
between the opening of the air valve and the actual discharge of
fuel from the secondary nozzles. acceleration: The rate of change
of velocity or speed. Velocity is steady and is measured in
distance per time (e.g., feet per second, miles per hour,
kilometers per hour). Acceleration keeps increasing and is measured
in velocity per time (e.g., feet (or meters) per second per second
or feet (or meters) per second squared). It is a vector quantity
and has both magnitude and direction.Also see angular acceleration
lateral acceleration sluggish acceleration yaw acceleration
acceleration due to gravity: (g) Acceleration with which a body
would fall freely under the action of gravity in a vacuum. This
varies according to the distance from the Earth's center, but the
internationally adopted value is 9.80665ms-2.Also see Helmert's
formula
acceleration enrichment:
The action of increasing the fuel/air mixture during
acceleration in order to improve the vehicle's speed and its smooth
response. acceleration error: The error in an airborne magnetic
compass due to maneuvering; caused by the vertical component of the
Earth's magnetic field when the center of gravity of the magnetic
element is displaced from normal. acceleration pump:See auxiliary
acceleration pump
acceleration slip regulation: (ASR) The Bosch term for traction
control. acceleration stress: The influence of acceleration (or
deceleration) on certain physiological parameters of the human
body. Man can withstand transverse accelerations better than
longitudinal ones, which have a profound effect on the
cardiovascular system. The degree of tolerance also depends on the
magnitude and duration of the acceleration. acceleration tolerance:
The maximum acceleration force that a person can withstand before
"blacking out" or otherwise losing control. accelerator: [1] In
automobiles, this is the "gas pedal" which is attached by linkage
to the throttle in the carburetor or to the fuel injection system.
It regulates the amount of fuel which is sent to the engine. In
motorcycles, the accelerator is located on the right-hand twist
grip or an actuating lever. [2] A device, similar to a catapult,
but generally
mounted below deck level, for assisting the acceleration of
aircraft flying off aircraft carriers. Land versions have been
tried experimentally. [3] A chemical which is added to something to
make a process happen more quickly. For example, a chemical may be
added to paint to cause it to dry faster. The opposite is
"retarder." A material added to an adhesive to speed up its cure or
to chemically convert the whole mass to a solid. Accelerators
differ from catalysts in that they are a part of the chemical
reaction and lose their chemical identity as a result. [4] A
substance which increases the efficient action of an enzyme [5] Any
substance increasing the speed of the vulcanization process of
rubber. The principal types are aldehyde derivatives of Schiff's
bases: butyraladehyde-butylideneaniline, di-orthotolylguanidine,
diphenylguanidine, benzthiazyl disulphide, tetramethylthiuran
disulphide and zinc dimethyl-dithiocarbamate. [6] A special circuit
board which is placed within a computer to speed up some aspect of
its operation. [7] Machine used to accelerate charged particles to
very high energies such as betatron, cyclotron, linear
accelerator, synchrocyclotron, and synchrotron. [8] A chemical
used to increase the rate of development, e.g., sodium carbonate or
borax [9] Any muscle or nerve which increases rate of action.Also
see depress the accelerator ease up on the accelerator step on the
accelerator take foot off the accelerator
accelerator board: A circuit board plugged into a computer
motherboard to increase the operating speed of a computer.
accelerator interlock: A connection between the gas pedal and the
automatic transmission. accelerator pedal: The accelerator, gas
pedal, or throttle pedal. accelerator pump: A small cylinder and
piston usually located inside the carburetor that sprays an extra
amount of fuel into the engine during acceleration. It improves
acceleration by giving more boost and reducing a momentary lag in
power. It is actuated by depressing the pedal. accelerometer: [1] A
transducer used to provide a signal proportional to the rate of
acceleration of a vibrating or other body, usually employing the
piezoelectric principle. [2] An instrument which measures the
amount of acceleration in a specific direction.Also see impact
accelerometer vertical-gust recorder
acceptable quality level: (AQL) A manufactured good that may not
be perfect but does reach a level of shape, size, and performance,
etc. that will make it work and last as long as the manufacturer
expects. acceptance angle: The solid angle within which all
incident light reaches the photocathode of a phototube. acceptance
test: An examination of a part or its assembly to determine if it
meets a prescribed standard. acceptor: [1] The reactant in an
induced reaction whose rate of reaction with a third substance is
increased by the presence of the inductor. [2] The atom which
accepts electrons in a co-ordinate bond. [3] Impurity atoms
introduced in small quantities into a crystaline semiconductor and
having a lower valency than the semiconductor, from which they
attract electrons. In this way holes are produced, which
effectively become positive charge carriers; the phenomenon is
known as p-type conductivity.Also see donor impurity
acceptor level:See energy levels
access: A way of reaching something that is usually hidden or
covered.Also see access panel
Access Cab: A type of pickup truck (by Toyota) which as a second
row of seating; but unlike a crew cab (which has four full size
doors) it has a "half-door" that can be opened only after the main
door is opened. The seating is usually a
little more cramped than in a crew cab. Also called club Cab,
extended Cab, king Cab, xtracab, supercab, or cab Plus access
charge: A financial charge for access to a computer or
telecommunications network. access eye: A screwed plug provided in
soil, waste and drain pipes at bends and junctions, to clear a
stoppage. access hole: An opening through which you can reach
something. It is usually covered with a panel. accessible hermetic:
Assembly of motor and compressor inside a single bolted housing
unit. accessories: Items and packages of equipment which are beyond
the standard equipment supplied in a new vehicle. accessory:See
accessories
accessory gearbox: A gearbox, driven remotely from an
aero-engine, on which aircraft accessories, e.g., hydraulic pump
and electrical generator, are mounted. accessory minerals: Minerals
which occur in small, often minute, amounts in igneous rocks; their
presence or absence makes no difference to classification and
nomenclature. accessory package:
A set of features or appointments which may be ordered at extra
cost on a new vehicle. accessory plates: Quartz-wedge, gypsum plate
and mica plate. Used with petrological microscope to help determine
the optical character of a mineral as an aid in its examination.
accessory shoe: A mounting bracket on the body of a camera to which
separate units such as a flash or range-finder may be fitted.
access panel: The cover which conceals the engine on a mid-engine
vehicle. Also called engine cover.Also see hood
access time: The time interval between the instant at which data
are called from memory and the instant at which the data can be
used. It can vary from microseconds with fast store to minutes with
magnetic tape. access to store: Entry or extraction of data from a
memory location. The method and speed of access depends on the type
of memory.Also see backing store fast store random access memory
serial access memory
accident:See car accident
accident damage: The destruction caused to a vehicle's bodywork
when it is involved in an accident.
ac circuit: A circuit which passes alternating current as
opposed to direct current, e.g., it may have a capacitor in series,
which blocks direct current. ac commutator motor: An ac motor which
embodies a commutator as an essential part of its construction.Also
see ac series motor compensated induction motor repulsion motor
Schrage motor
Accord: A model of automobile manufactured by Honda
. Click for books on Honda Accord
accordion: The method of folding a leaflet or insert so that it
opens out and closes in a zig-zag fashion. The British term is
concertina fold. accretion: [1] The process in which a celestial
body, particularly an evolved star in a binary system, is enlarged
by the accumulation of extraneous matter falling in under gravity
[2] The process of enlargement of a continent by the tectonic
coalescences of exotic crustal fragments. accretion disc: The disc
of material at the edge of a black hole, which has been attracted
from a neighboring star and which emits X-rays as its inner edge
disappears into the gravitational field of the hole.
accumulation point: A mathematical term which says that of a set
of points, one such that every neighborhood of it includes at least
one point of the set. accumulator: [1] A storage battery for an
electric car. [2] A pressurized container for an automatic leveling
suspension system. [3] A part of the hydraulic system which is
charged by the fluid pump, absorbs fluctuating fluid delivery,
stores fluid at pressure, and can provide a rapid flow of fluid
under pressure. [4] A vessel that stores hydraulic fluid under
pressure. [5] A storage tank which receives liquid refrigerant from
evaporator and prevents it from flowing into the suction line
before vaporizing. [6] A refrigerant storage device used on General
Motors and Ford systems that receives vapor and liquid refrigerant
from the evaporator. The accumulator, which contains "desiccant,"
performs a function similar to that of a receiver-drier: it
separates liquid from the vapor, retains the liquid and releases
the vapor to the compressor. Always located on the low side of the
system. [7] A special storage register associated with the
arithmetic logic unit, used for holding the results of a
computation or data transferAlso see accumulator piston fuel
accumulator hydraulic accumulator pressure accumulator
accumulator battery: A storage battery (i.e., the main battery
in your vehicle). accumulator box: A vessel usually made of plastic
which contains the plates and electrolyte of an accumulator.
accumulator drier: A device which is part of the air conditioning
system. It is made up of a tank, filter, drying agent, and a vapor
return tube. It is usually found on the
evaporator outlet. It stores the excess refrigerant and removes
the moisture from the refrigerant (thus the name "drier").Also see
receiver drier
accumulator grid: The lead grid which forms one of the plates of
a lead-acid accumulator having pasted plates. accumulator piston: A
unit found in the automatic transmission to assist the servo to
apply the brake band quickly and smoothly. accumulator system: In
an automatic transmission, it includes a hydraulic accumulator
piston which is controlled by a valve. accumulator traction:See
battery traction
accumulator valve: A device which operates the hydraulic
accumulator piston in an automatic transmission. accumulator
vehicle:See battery traction
AC current sine wave: Wave form of single frequency alternating
current; wave whose displacement is sine of angle proportional to
time or distance. Ace: An American trucker's colloquial term for
someone with a class "A" licence.Also see AC Ace
ACEA: Acronym for "Association des Constructeurs europens
dAutomobiles" (i.e., European Automakers Association). Aceca:See AC
Aceca
acet-: Prefix from the Latin acetum meaning vinegar. acetate
film: Film with its photographic emulsion coated on a base of
cellulose triacetate, of low flammability. aceto-: Prefix from the
Latin acetum meaning vinegar. acetylene: [1] Ethyne HCCH. A
colorless, poisonous gas, owing its disagreeable odor to
impurities; soluble in ethanol, in acetone (25 times its volume at
standard temperature and pressure) and in water. Boiling point
-84C, relative density 0.91. Prepared by the action of water on
calcium carbide and catalytically from naphtha. [2] A gas composed
of two parts of carbon and two parts of hydrogen. When burned in an
atmosphere of oxygen, it produces one of the highest flame
temperatures obtainable for welding. [3] Also used for
illuminating, acetic acid synthesis and for manufacturing
derivativesAlso see oxygen acetylene cutting
acetylene bottle:See acetylene cylinder
acetylene cutting:See oxygen acetylene cutting
acetylene cylinder: A specially built container manufactured
according to I.C.C. Standards. Used to store and ship acetylene.
Also called acetylene tank or acetylene bottle
acetylene hose: A flexible medium used to carry gases from
regulators to the torch. It is made of fabric and rubber. acetylene
regulator: An automatic valve used to reduce acetylene cylinder
pressures to torch pressures and to keep the pressures constant.
acetylene tank: acetylene cylinder. acetyl group: Ethanoyl group
CH3CO-. The radical of acetic acid. aceval: Abbreviation for air
combat evaluation.
AC generator: [1] An electromagnetic generator for producing
alternating emf and delivering ac to an outside circuit. [2] A
generator produces direct current (DC) while an alternator produces
alternating current (AC). Because alternators were introduced to
automobile electrical systems after generators had been in use for
some time, some people referred to the new alternator as "AC
generator." ache:See head ache rack
ache rack:See head ache rack
achromatic lens: A lens designed to minimize chromatic
aberration. The simplest form consists of two component lenses, one
convergent, the other divergent, made of glasses having different
dispersive powers, the ratio of their focal lengths being equal to
the ratio of the dispersive powers. achromatic prism: An optical
prism with a minimum of dispersion but a maximum of deviation.
achromatic sensation: A visual perception of grey. Represented by
the equal energy point on a chromaticity diagram. achromatic
stimulus: Stimulus which produces an achromatic sensation.
acid:Also see battery acid chromic acid
oxalic acid
acid brittleness: The brittleness developed in steel in pickling
bath, through evolution of hydrogen. acid condition in system:
Condition in which refrigerant or oil in system is mixed with
fluids that are acid in nature. acid cure: In extraction of uranium
from its ores, lowering of gangue carbonates by puddling with
sulphuric acid before leach treatment. acid deposition: Acid
compounds emitted into the atmosphere which then return to the
surface either in the form in which they were discharged or as new
compounds formed by reaction in the atmosphere. Includes dry
deposition, usually of sulphur and nitrogen oxides near the source,
and wet deposition which follows when acids are washed from the
atmosphere by precipitation (i.e., acid rain and occult deposition.
acid drift: The process by which ores, pulps, and products become
acidic through pick-up of atmospheric oxygen through standing. acid
dyes: Dyes which have their color associated with the negative ion
or radical. acid egg: A pump for sulphuric acid, of simple and
durable construction, with few moving parts. The acid is run into a
pressure vessel, usually egg-shaped, from which it can be forcibly
expelled by compressed air. acid fixer: Fixing solution (hypo) with
the addition of an acid (sodium bisulphite or potassium
metabisulphite) to prevent staining.
acidizing: Improving the flow of oil from a limestone formation
by pumping acid into it. acid mine water: Water containing
sulphuric acid as a result of the breakdown of the sulphide
minerals in rocks. Acid mine water causes corrosion of mining
equipment, and may contaminate water supplies into which it drains.
acid process: [1] A steel-making process in which the furnace is
lined with a siliceous refractory, and for which iron low in
phosphorous is required, as this element is not removed. [2] Any
pulp digestion process utilizing an acid regent, e.g., a bisulphite
liquor with some free sulphur dioxide. acid rain: [1] When the
smoke created by factories and vehicle exhausts is taken by the
wind and joined with rain clouds, the mixture is often acidic. As a
result the rain that falls to the ground (and even on your car) may
damage whatever it strikes. [2] A form of wet deposition in which
acid molecules or particles in the atmosphere are returned to the
surface having been washed out by rain or snow as it falls. The
unnatural acidity (pH 3-5.5) is caused mainly by the oxides of
sulphur and nitrogen from the burning of coal and oil. acid
refractory:See silica
acid resist foils: Blocking foils for use in etching metal. The
foil is stamped on to paper and the excess foil blocked on to the
metal rule or other object which is then exposed to an acidic
etching fluid such as ferric chloride. acid rock:
An igneous rock with more than 63% quartz. acid slag: Furnace
slag in which silica and alumina exceed lime and magnesia. acid
smut:See acid soot
acid soot: A pollutant, consisting of particles of carbon bound
together by water containing sulphuric acid, formed as a by-product
of the incomplete combustion of carbon-based fuel. Also called acid
smut. acid steel: Steel made by an acid process. acid stop: Weak
acid photography processing solution used immediately after the
developer to halt its chemical activity and neutralize it before
fixing. AC Ignition System:See continuous AC Ignition System
Ackermann:See Ackermann steering
Ackermann steering: [1] A double-pivoting steering system where
the outer ends of the steering arms are bent slightly inward so
that when the vehicle is making a turn, the inside wheel will turn
more sharply than the outer wheel. This is done to compensate for
the greater distance the outside wheel must travel. Notice 20
degrees on left wheel and 30 degrees on right wheel [2] Arrangement
whereby a line extended from the track-arms, when the wheels are
set straight ahead, should meet on the chassis centerline at 2/3 of
the wheelbase from the front, allowing the inner stub-axle to move
through a greater angle than the outer. Ackermann angle: The
toe-out or toe-in of a vehicle with Ackermann steering when the
wheels are positioned straight ahead. Ackermann axle: In a vehicle
with Ackermann steering (at the front of the vehicle), it is a
non-rotating axle that is steerable and has two pivot points (one
on each end of the axle) with vertical kingpins. acknowledgement
signal: A signal transmitted along a circuit from B to A when
triggered by a signal from A to B. A-class insulation: Insulating
material which will withstand temperatures up to 105C. ACL BI-MET:
Acronym for "air cleaner bi-metal sensor". ACL DV: Acronym for "air
cleaner duct and valve vacuum" motor.
ACM: Abbreviation for Association for Computing Machinery, a US
professional association. ac magnet: Electromagnet excited by
alternating current having normally a laminated magnetic
circuit.Also see shaded pole
acme screw-thread: A thread having a profile angle of 29 and a
flat crest and root, used for example for lathe lead screw for easy
engagement by a split nut. acmite: A variety of aegirine; also used
for the NaFe+3Si2 O6 end-member. ac motor: An electric motor which
operates from a single or polyphase alternating current supply.Also
see capacitor motor induction motor synchronous motor
acnode:See double point
acoustic absorption: Transfer of energy into thermal energy when
sound is incident at an interface. acoustic absorption coefficient:
The ratio of the acoustic energy absorbed by a surface to that
which is incident on the surface. For an open window this can be
1.00, for painted plaster 0.02. The value varies with the frequency
of the incident sounds, e.g., for 2 cm glass fiber it is 0.04 at
125 Hz, 0.80 at 4000 Hz. Also called acoustic absorption
factor.
acoustic absorption factor: The ratio of the acoustic energy
absorbed by a surface to that which is incident on the surface. For
an open window this can be 1.00, for painted plaster 0.02. The
value varies with the frequency of the incident sounds, e.g., for 2
cm glass fiber it is 0.04 at 125 Hz, 0.80 at 4000 Hz. Also called
acoustic absorption coefficient. acoustical inertia: The quantity
M, where M is the part of the acoustical reactance which
corresponds to the inductance of an electrical reactance: is the
pulstance, given by 2f is the frequency in hertz. Also called
acoustical mass. acoustical mass: The quantity M, where M is the
part of the acoustical reactance which corresponds to the
inductance of an electrical reactance: is the pulstance, given by
2f is the frequency in hertz. Also called acoustical inertia.
acoustical stiffness: For an enclosure of volume V, the quantity
given by S-pc/V, where c is velocity of propagation of sound and p
is density. It is assumed that the dimensions of the enclosure are
small compared with the sound wavelength and that the walls around
the volume do not deflect. acoustic amplifier: An amplifier of
mechanical vibrations. acoustic branch: A branch of the dispersion
curve (frequency against wavenumber q) for crystal lattice
vibrations for which is proportional to q for small q. For a
crystal containing n atoms per unit cell, the dispersion curve has
3n branches of which three are acoustic branches. The branches are
characterized by different patterns of movement of the atoms.Also
see optic branch
acoustic center:
The effective source point of the spherically divergent wave
system observed at distinct points in the radiation field of an
acoustic transducer. acoustic compliance: The reciprocal of the
acoustic stiffness. acoustic construction: Building construction
which aims at the control of transmission of sound, or of
mechanical vibration giving rise to sound, particularly unwanted
noises. The parts of the structure are separated by air-spaces or
acoustic absorbing material and can be decoupled by the interposing
of springs. acoustic coupler: A device which enables a digital
signal to be transmitted over the telephone network using an
ordinary telephone handset. acoustic delay line: A device,
magnetostrictive or piezoelectric, e.g., a quartz bar or plate of
suitable geometry, which reflects an injected sound pulse many
times within the body. acoustic distortion: Distortion in
sound-reproducing systems. acoustic emission: Non-destructive
testing method of investigating deformation and failure processes
in materials by the signals generated when the elastic waves
released by them are detected at the materials' surfaces. acoustic
feedback: Instability or oscillation in a second reproduction
system caused by the microphone or pick-up receiving vibrations
from the loudspeaker. acoustic filter: Filter which uses tubes and
resonating boxes in shunt and series as reactance elements,
providing frequency cut-offs in acoustic wave
transmission, as in an electric wave filter. acoustic grating: A
diffraction grating for production of directive sound. Spacings are
much larger than in optical gratings due to the longer wavelength
of sound waves. Both transmission and reflection grating are used.
acoustic impedance: the complex ratio of sound pressure on surface
to sound flux through surface, having imaginary (reactance) and
real (resistance) components, respectively. Unit is the acoustic
ohm. acoustic interferometer: Instrument in which measurements are
made by study of interference pattern set up by two sound or
ultrasonic waves generated at the same source. acoustic lens: A
system of slats or disks to spread or converge sound waves.
acoustic microscope: Microscope based on acoustic waves
(longitudinal compressions and rarefactions of density) at
microwave frequencies the interaction of an acoustic wave with a
material is sensitive to its elastic properties. Images can be
created by modulating a display with the intensity received by a
detector/specimen system scanned synchronously (ultrasonic
imaging). Coupling between electrical signals and acoustic
vibrations exploits the piezoelectric effect. acoustic model: A
scale model of a room (e.g., concert hall) or structure which is
used to measure qualities important for architectural acoustics and
noise control (e.g., sound distribution). The scale is typically
between 1:10 and 1:20. In order to adjust the wavelength, the
frequency has to be increased by a factor of 10-20. acoustic
ohm:
Unit of acoustic resistance, reactance, and impedance, equal to
105Pasm-3. acoustic perspective: The quality of depth and
localization inherent in a pair of ears, which is destroyed in a
single channel for sound reproduction. It is transferable with two
microphones and two telephone ear-receivers with matched channels,
and more adequately realized with three microphones and three
radiating receivers with three matched channels. acoustic plaster:
Rough or flocculent plaster which has good acoustic absorbing
properties and which can be used for covering walls. Added to the
mix is fine aluminum, which evolves gas on contact with water and
so aerates the mass. These tiny holes lower the acoustic impedance
and so reduce the reflection of incidence sound waves. acoustic
pressure:See sound pressure
acoustic radiator: Device to generate and radiate sound. The
more common radiators are (1) vibrating elastic systems (membrane,
string, vocal cord) which cause a fluctuating pressure in the
surrounding medium; (2) electrically driven membranes and plates
(loudspeaker, sonar transducer); (3) vortices in turbulent fluid
flow. acoustic ratio: The ratio between the directly radiated sound
intensity from a source, at the ear of a listener (or a
microphone), and the intensity of the reverberant sound in the
enclosure. The ratio depends on the distance from the source, the
polar distribution of the radiated sound power, and the period of
reverberation of the enclosure. acoustic reactance:See acoustic
impedance
acoustic resistance:See acoustic impedance
acoustic resonance: Enhancement of response to an acoustic
pressure of a frequency equal or close to the eigenfrequency of the
responding system. When a system is at resonance, the imaginary
part of its impedance is zero. Prominent in Helmholtz resonators,
organ, and other pipes and vibrating strings. acoustics: [1] The
science of sound waves including production and propagation
properties. [2] The characteristics of a room which determine the
quality of sound transmission inside.Also see architectural
acoustics atmospheric acoustics
acoustic saturation: The aural effectiveness of a source of
sound amid other sounds; it is low for a violin, but high for a
triangle. The relative saturation of instruments indicates the
number required in an auditorium of given acoustic properties.
acoustic scattering: Irregular and multi-directional reflection and
diffraction of sound waves produced by multiple reflecting surfaces
the dimensions of which are small compared to the wavelength; or by
certain discontinuities in the medium through which the wave is
propagated. acoustic spectrometer: An instrument designed to
analyze a complex sound signal into its wavelength components and
measure their frequencies and relative intensities.Also see
real-time analyzer
acoustic spectrum: Graph showing frequency distribution of sound
energy emitted by source. acoustic streaming:
Generation of constant flows by a strong sound wave. Acoustic
streaming is a non-linear effect. It is responsible for the motion
of the light particles (lycopodium spores) in a Kundt's tube.Also
see quartz wind
acoustic survey: Determination of the porosity of a rock by
measuring the time required for a sonic impulse to travel through a
given distance. acoustic suspension: Sealed-cabinet system of
loudspeakers in which the main restoring force of the diaphragm is
provided by the acoustic stiffness of the enclosed air. acoustic
telescope: An array of microphones. The signals of the microphones
are added with certain phase-delays so as to generate desired
directions.Also see directional microphone
acoustic tile: A tile made of soft, sound-absorbing substance.
acousto-optic modulator: A telecommunication device in which
acoustic waves in an optical medium from a grating used to diffract
an optical signal and thus effectively turn it on or off.
acquisition fee: A charge for processing a lease and is probably
not negotiable. On a shorter term lease, the acquisition fee can
have a large impact on the cost of the lease. ACR: Abbreviation for
approach control radar. acro-:
Prefix from Greek akros (), topmost, farthest, terminal.
Acrobat: Trade name for a computer application which converts text,
line drawings, and half-tones into a stream of alphanumeric text
while retaining the format of the original. Such a page description
file (PDF) is an extension of the Adobe PostScript language and can
be read by any type of computer. acronical rising: The rising of a
star at nightfall. acronical setting: The setting of a star at
nightfall. acronychal: British term for "acronical". across
corners: (A/C) The distance on a nut (for instance) from one corner
to the opposite corner rather than the distance from one flat
surface (A/F) to the opposite (which would be the size of wrench
needed to install or remove the nut). The purpose of the A/C
dimension is to know how large a hole might be needed to insert a
recessed nut. across flats: (A/F) The distance on a nut (for
instance) from one flat surface to the opposite flat surface, i.e.,
this is the size of the wrench needed to install or remove the
nut.Also see across corners.
acroterium: A base or mounting on the apex and/or extremities of
a pediment, for the support of an ornamental figure or
statuary.
ACR tubing: Tubing used in air conditioners and refrigerators.
The ends are sealed to keep tubing clean and dry. acrux: A bright
white supergiant star in the constellation Crux. A visual binary
consisting of two spectroscopic binary components. Distance 80 pc.
Also called Alpha Crucis. acrylate: A polymer used to strengthen
rubber (e.g., ethyl acrylate). acrylic: A term relating to a type
of paint made by polymerizing acrylonitrile. acrylic fibers:
Continuous filaments or, more fibers from linear polymers which are
synthesized from several monomers containing at least 85% by weight
of acrylonitrile. acrylic finish: A final coating of paint which
uses acrylic paint, often where the pigment and an acrylic paint
are mixed together.Also see two-pack paint.
acrylic paint: A type of paint made by polymerizing
acrylonitrile. acrylic resin: A thermoplastic synthetic polymer
made by polymerizing an acrylic derivative such as acrylonitrile,
acrylic acid, ethyl acrylate, and methacrylate. It is used for
adhesives, protective coatings, and paint finishes. ACS:
[1] Abbreviation for active control system [2] Abbreviation for
attitude control system [3] Abbreviation for air conditioning
system . ac series motor: A series motor which operates from an ac
supply with laminated field construction and usually a compensating
winding. AC Shelby Cobra: A vehicle brand of which the 1962-67
Shelby Cobra models are milestone cars. ACT: [1] Acronym for "air
charge temperature." [2] Acronym for active control technology.Also
see active control system
act:See Motor Vehicle Safety Act
acting:See double-acting dual-acting single-acting
actinic radiation: Ultraviolet waves, which have enhanced
biological effect by inducing chemical change; basis of the science
of photochemistry. actinic rays: Electromagnetic waves of
wavelength that can cause a latent image, potentially able to be
developed, in a photographic emulsion. They include an extension at
each end of the visible spectrum and X-rays. actino-:
Prefix from Greek aktis (). actinolite: A monoclinic calcium
magnesium iron member of the amphibole group, green in color and
usually showing an elongated or needle-like habit; occurs in
metamorphic and altered basic igneous rocks. action: [1] The
performance of a scene to be recorded on camera [2] The film record
of this performance as picture only, separate from the sound record
[3] The time integral of kinetic energy (E) of a conservative
dynamic system undergoing a change, given by this formula:Also see
capillary action caster action mist action oscillating action
parallel action locking pliers reciprocating action
action brakes:See servo action brakes
action locking:See parallel action locking pliers
action locking pliers:See parallel action locking pliers
activate: To change an adhesive film from a dry or inactive
state to a useful, sticky state. activated:See cable activated
activated alumina:
Chemical which is a form of aluminum oxide. it is used as a
drier or desiccant. activated carbon: [1] A highly porous carbon
which is able to absorb gases and fluids. It is usually found in
small pellets so that the surface area is greater than a large
chunk of it. Also it has a number of pores on each pellet to
increase the surface area more. Thus the greater surface area means
greater ability to absorb. Used to clean air. Also called activated
charcoal. [2] Carbon obtained from vegetable matter by
carbonization in the absence of air, preferably in a vacuum.
Activated carbon has the property of absorbing large quantities of
gasses. Important for gas masks, adsorption of solvent vapors,
clarifying of liquids, and in medicine. activated carbon canister:
An automotive filter in which activated carbon has been placed so
that gas tank fuel vapors, which have accumulated when the vehicle
is not running, are trapped in the filter. When the engine is
running, hot air is forced into the filter and push out the vapors
into the engine. In this way, pollution is reduced and conservation
of the fuel is maintained. Also called activated charcoal trap or
charcoal canister. activated cathode: Emitter in thermionic devices
comprising a filament of basic tungsten metal, alloyed with
thorium, which is brought to the surface by process of activation,
such as heating without electric field. activated charcoal:
Charcoal treated with acid to increase its adsorptive powerAlso see
activated carbon charcoal
activated charcoal trap:See activated carbon canister
activated sintering: Sintering of a compact in the presence of a
gaseous reactant. Also called reaction sintering.
activating agent:See activator
activation: [1] Alteration of the surface of a metal to a
chemically active state. Compare passivation [2] Induction of
radioactivity in otherwise non-radioactive atoms, e.g., in a
cyclotron or reactor. activation cross-section: The effective
cross-sectional area of a target nucleus undergoing bombardment by
e.g., neutrons for radioactivation analysis. Measured in barns.Also
see cross-section
activator: [1] A substance which is used to speed up the process
of curing a tire. [2] Surface-active chemical used in a flotation
process to increase the attraction to a specific mineral in an
aqueous pulp of collector ions from the ambient liquid and increase
in aerophilic quality. Also called activating agent. active array:
An antenna array in which the individual elements are separately
excited by integrated circuit or transistor amplifiers. active
braking time: The length of time (excluding the driver's reaction
time) a vehicle takes to come to a complete stop after the brakes
are applied. active component: The component of the vector
representing an alternating quantity which is in phase with some
reference vector; e.g., the active component of the current,
commonly called the active current.Also see
active current active voltage active volt-amperes
active control: Modern technique of noise or vibration control
using one or more sources that generate signals with the aim of
making the resulting total signal smaller. Used for example for the
control of low-frequency airborne noise and vibration of
machinery.Also see antisound
active control system: (ACS) An advanced automatic flight
control system designed to provide several special features, for
example activation of flight control surfaces to minimize gust
loads and bending stresses in the wing by detection and response to
normal accelerations, provision of stability to a naturally
unstable aircraft and implementation of pilot maneuver demands. All
these characteristics improve aircraft behavior and performance,
but the active control system demands extensive integration between
aerodynamics, structure, and electronic system design to achieve
these advantages with reliability and safety. active current: The
component of a vector representing the ac in a circuit which is in
phase with the voltage of the circuit. The product of this and the
voltage gives power. active device: A component capable of
controlling voltages or currents, to produce gain or switching
action in a circuit, valves, diodes, and transistors, and
integrated circuits are all classed as active devices or
components. active electrode: The electrode of an electrical
precipitator which is kept at a high potential. Also called
discharge electrode.. active filter:
A filter which combines amplification with conventional passive
filter components (capacitance, inductance, resistance) to enhance
fixed or tunable passband or rejection characteristics. active
galaxy: A galaxy which emits unusually large amounts of radiation
from a compact central source, such as Seyfert galaxy, N galaxy,
quasar, or BL Lac object. active homing: A guidance system where
the missile contains the transmitter for illuminating the target
and the receiver for the reflected energy. active lattice: The
regular pattern of arrangement of fissionable and non-fissionable
materials in the core of a lattice reactor. active lines: Lines
which are effective in establishing a picture. active material: In
a storage battery, peroxide of lead (brown) in positive plates and
metallic lead (gray) in negative plates upon which sulphuric acid
acts. active materials: [1] General term for essential materials
required for the functioning of a device, e.g., iron or copper in a
relay or machine, electrode materials in a primary or secondary
cell, emitting surface material in a valve, or photocell,
phosphorescent and fluorescent material forming a phosphorescent
and fluorescent material forming a phosphor in a cathoderay tube,
or that on the signal plate of a TV camera. [2] Term applied to all
types of radioactive isotopes. active noise control system:See
anti-noise system
active power:
The time average over one cycle of the instantaneous input
powers at the points of entry of a polyphase circuit.Also see
active volt-amperes
active safety: The opposite of passive safety. Passive safety
involves seat belts, airbags, bumpers, etc. so that in the event of
an accident the passengers are protected. Active safety involves
factors which will assist the driver in avoiding an accident. They
include brakes, steering, handling response, acceleration, etc.
active satellite: A satellite equipped for sending out probing
signals and receiving returned information. A passive satellite
receives information only on the state of the target. active sun:
The Sun during periods of intense sunspot activity. active
suspension: While conventional suspension uses springs and shock
absorbers to isolate the vehicle from the bouncing movement of the
wheels when it contacts rough roads, active suspension uses power
actuators which are controlled by a computer. These actuators place
the wheels of the vehicle in the best position to accommodate rough
roads as well as compensate for different load levels. active
transducer: Any transducer in which the applied power controls or
modulates locally supplied power, which becomes the transmitted
signal, as in a modulator, a radio transmitter or a carbon
microphone. active voltage: The component of a vector representing
the voltage which is in phase with the current in a circuit.
active volt-amperes: The product of the active voltage and the
amperes in a circuit, or of the active current (amperes) and the
voltage of the circuit; equal to the power in watts. Also called
active power. activities:See Kaizen Activities
activity: [1] The magnitude of the oscillations of a
piezoelectric crystal relative to the exciting voltage [2] The rate
at which transformations occur in a radionuclide. Unit is the
becquerelAlso see catalytic activity low temperature activity
specific activity
activity factor:See blade activity factor
ac transformer: an electromagnetic device which alters the
voltage and current of an ac supply in inverse ratio to one
another. It has no moving parts and is very efficient. ACTS:
Acronym for "air charge temperature sensor". actual cash value:
(ACV) The amount of money a dealer has invested in the purchase of
a used vehicle and any additional costs to repair the unit in order
to get it ready for resale. actual throat: A welding term which
describes the distance from the face of a weld to the root of the
weld.
actuate: The action of bringing a part or assembly into
operation. actuating lever: A triggering device used to bring a
part or assembly into operation. actuating switch: A triggering
device used to bring a part or assembly into operation.
actuation:See variable valve actuation
actuator: [1] A Device which controls or operates another
device. [2] The portion of a regulating valve which converts
mechanical fluid, thermal energy, or electrical energy into
mechanical motion to open or close the valve seatsAlso see
hydraulic actuators
actuator arm: An arm connecting the diaphragm to the contact
breaker platform in an advance mechanism. Also called diaphragm
link.. Acura: A vehicle brand from the Honda manufacturers. Click
for books on Acura
acutance: Objective formulation of the sharpness of a
photographic image, expressed as where . "N" is the number of
increments between "A" and "B", DB-DA is the average gradient of
density curve, and D/x is the maximum gradient curve.
ACV: [1] Acronym for "actual cash value." [2] Acronym for "air
control valve" [3] Acronym for air cushion vehicle (i.e.,
hovercraft). ad:See classified ad
A-D: Analogue-to-digital, referring to the conversion of
signals. adamantine:See lustre
adaptation layer:See ATM adaptation layer
adapter: [1] A device used to connect two different types or
sizes of electrical terminals [2] An arrangement for using types of
photographic material in a camera different from that for which it
was designed; e.g., filmpack in a plate camera, or a smaller plate
than normal [3] A device for the interchange of lenses between
different types of camera [4] A connector which links two items
usually of dissimilar structure or size. (Also spelled
"adaptor")Also see bit adapter bit adapter caliper mounting bracket
carburetor adapter engine adapter increasing adapter ratchet
adapter reducing adapter transmission adapter wheel adapter.
adaptive array: A radar antenna (either a phased array or an
active array) whose gain, directivity and side lobes can be
adjusted automatically to optimize the radar's performance under
specific operating conditions. adaptive control: The ability of a
control unit to adapt its closed-loop operation to changing
operating conditions -- such as engine wear, fuel quality or
altitude -- to maintain proper air-fuel mixture control, ignition
timing or idle rpm. Also referred to as self-learning. adaptive
differential pulse code modulation: A form of differential pulse
code modulation in which the basic step size is varied continually
to suit the rate of change of the signal. A further refinement is
to transmit only differences from a continually adjusted prediction
of the signal. These measures greatly reduce the required
bandwidth. adaptive radiation: Evolutionary diversification of
species from a common ancestral stock, filling available ecological
niches. Also called divergent adaptation. adaptor carburetor: A
device attached to a gasoline carburetor which permits an internal
combustion engine to run either on gas or liquefied petroleum gas
(LP gas). adapter plate: A plate which is placed between two
different parts in order to link them. (Also spelled "adaptor
plate")Also see transfer plate
Adcock antenna: A directional antenna consisting of pairs of
vertical wires, spaced by one half wavelength or less, and fed in
phase opposition; a figure-of-eight radiation pattern results, and
arrays of Adcock antennas can be used for direction-finding.
ADD: Acronym for "airstream direction detector" which is used
for aircraft stall protection. add-drop multiplexer: Equipment used
to add data originating from a particular source or group of
sources to a synchronous digital hierarchy data stream, or
conversely to extract data destined for a particular source or
group of sources. addendum: [1] The radial distance between the
major and pitch cylinders of an external thread. [2] The radial
distance between the minor and pitch cylinders of an internal
thread the height from the pitch circle to the tip of the tooth on
a gearwheel. addition agent: A substance added to the electrolyte
in an electro deposition process in order to improve the character
of the deposit formed. The agent does not take part in the main
electrochemical reaction. additive: A substance (liquid or powder)
which is added to gasoline or oil and is intended to improve the
characteristics of the original product.Also see anti-knock
additive fuel additive oil additive
additive constant: A survey term used in the computation of
distance by tacheometric methods. It is that length (usually
constant and small) which must be added to the product of staff
intercept and multiplying constant to give the true distance of the
object.Also see anallatic lens
additive printer: Photographic or motion picture printer or
enlarger in which the intensity and color of the exposing light is
controlled by the separate variation of its red, green, and blue
components. additive process: Color reproduction in which the
picture is presented by the combination (addition) of red, green,
and blue light representing these three components in the original
subject; it is effectively obsolete for general photography and
cinematography but is the basis for color TV display. ADEFA:
Acronym for "Asociacion de Fabricas de Automotores" (Argentina).
adenine: (A) One of the five bases in nucleic acids. It pairs with
thymine in DNA and uracil in RNA. ADF: Abbreviation for automatic
direction finding. adhara: Avery bright blue-white giant star in
the constellation Canis Major, which is a visual binary. Distance
200 pc. Also called Epsilon Canis Majoris. adhere: To stick or be
glued to something. adherend: [1] Each surface that is to adhere to
another [2] A material which is bonded by an adhesive. adhesion:
[1] The force which causes two surfaces to adhere, the sticking
together of surfaces in contact with each other
[2] The bonding of materials with adhesives (glues, cements,
binders, etc), in which the intermolecular forces between adhesive
and adherend provide the bonds. [3] The intimate sticking together
of metallic surfaces under compressive stresses by bonds which form
as a function of stress, time, and temperature. The speed of
formation is related to dislocation, and may occur virtually
instantaneously under high shear stresses.Also see cold welding
[4] The ability of paint, primer, or glue to stick to the
surface to which it is applied. [5] The ability of a tire to grip
the surface of the road. [6] Mutual forces between two magnetic
bodies linked by magnetic flux, or between two charged
non-conducting bodies which keeps them in contact [7]
Intermolecular forces which hold matter together, particularly
closely contiguous surfaces of neighboring media, e.g., liquid in
contact with a solid.Also see intercoat adhesion failure limits of
adhesion
adhesion failure:See intercoat adhesion failure
adhesive: [1] A substance (like glue) that is used to join two
substances. An adhesive must bond both mating surfaces through
specific adhesion (molecular attraction), through mechanical
anchoring (by flowing into holes in porous surfaces), or through
fusion (partial solution of both surfaces in the adhesive or its
solvent vehicle). Various descriptive adjectives are used with the
term adhesive to indicate types, such as: a. physical form liquid
adhesive, film adhesive, etc. b. composition resin adhesive, rubber
adhesive, silicone based, mastic, etc. c. end use metal-to-metal
adhesive, plastic adhesive, rubber adhesive d. application
sprayable adhesive, hot melt adhesive, etc.
[2] Agent for joining materials by adhesion, usually polymeric
material. May be based on thermoplastic resin (e.g., polystyrene
cement) or thermoset (e.g., epoxy resin). Viscosity is important
for gap filling (high, as in epoxies) or surface penetration (low,
as in cyano-acrylates). Also called binder, cement, or glueAlso see
automotive adhesive air drying adhesives impact adhesive
separate-application adhesive
adhesive binding: Unsewn binding in which the back of the
sections are trimmed and roughened before adhesive is applied to
bind the leaves and the cover. adhesive film: A thin layer of dried
adhesive. Also describes a class of adhesives provided in dry film
form with or without reinforcing fabric and which are cured by
means of heat and pressure. adhesive tape: A tape with a sticky
substance on one side. It usually comes in a roll of various
widths. Sometimes used to insulate electrical wires (e.g.,
electrical tape) or to wrap a larger object (e.g., duct tape).
Often the non-sticky side is shiny (but not always). adhesive wear:
Mechanism of wear due to the welding together and subsequent
shearing off of the contact areas between two surfaces sliding over
one another. adhesive weight: Lead wheel weights which have a
sticky backing. It comes in strips and is applied to a wheel rim.
Also called tape weight.. adiabatic: A property of being able to
maintain heat evenly. It does not gain any heat or lose it.Also
see
thermal efficiency
adiabatic change: A change in the volume and pressure of the
contents of an enclosure without exchange of heat between the
enclosure and its surroundings. adiabatic compression: Compressing
refrigerant gas without removing or adding heat. adiabatic curve:
The curve obtained by plotting pressure against volume in the
adiabatic equation. adiabatic demagnetization: A method of
obtaining very low temperatures. A paramagnetic salt is cooled to
1K by liquid helium. The salt is magnetized under isothermal
conditions and then magnetized under adiabatic conditions. As a
result the temperature falls. Temperatures below 10-2K can be
obtained this way. adiabatic efficiency: [1] Of a steam engine or
turbine, the ratio of the work done per unit mass of steam to the
available energy represented by adiabatic heat drop. [2] Of a
compressor, the ratio of that work required to compress a gas
adiabatically to the work actually done by the compressor piston or
impeller. adiabatic engine: An engine which is very efficient in
transferring combustion heat to those parts of the engine which are
being cooled by the flow of anti-freeze coolant -- thus maintaining
an even temperature of the engine. In this way the engine is warm
enough for efficient running and it does not overheat. adiabatic
equation: The equation PV = constant, expressing the law of
variation of pressure (P) with the volume (V) of a gas during an
adiabatic change, being the ratio of the specific heat of the gas
at constant pressure to that at constant volume. The value of is
approximately 1.4 for air at standard temperature
and pressure. adiabatic expansion: An adiabatic change in which
a substance expands. adiabatic heating: Self-heating effect which
occurs in extruder or injection molding barrel from action of
rotating screw on polymer melt. Attributed to dissipation of
mechanical shear forces as heat. Important in injection molding of
rubbers. Also called shear heating.Also see damping
adiabatic lapse rate: The rate of decrease of temperature which
occurs when a parcel of air rises adiabatically through the
atmosphere. adiabatic process: A process which occurs without
interchange of heat with surroundings. adiactinic: Said of a
substance which does not transmit photochemically active radiation,
e.g., safelights for darkroom lamps. adinole: An argillaceous rock
that has undergone albitization during contactmetamorphism. adipo-:
Prefix from Latin adeps "fat". A-display: Co-ordinate display on a
cathode-ray tube in which a level time base represents distance and
vertical deflections of beam indicate echoes. adit:
A horizontal passage or tunnel into a mine. adjacent channel: A
channel whose frequency is immediately above or below that of the
required signal. adjust: The action of putting something into its
proper alignment or position. It may involve one component (e.g.,
He adjusted the gasket to fit properly.) or a series of components
(e.g., He adjusted the poor idle -- might mean he set the ignition
timing, adjusted the carburetor screws, changed the choke setting,
cleaned or replaced the spark plugs, etc.)Also see tweak
adjustable: A characteristic of something that can be changed,
removed, or give different properties.Also see height adjustable
steering column
adjustable bottom bracket: [1] A component of a bicycle through
which the crank fits. It has two bearing cups on either side. One
cup is fixed in place while the other is removable or adjustable.
[2] This is the older type of bottom bracket before sealed
cartridge bottom brackets became prevalent. The adjustable bottom
bracket requires fixed and adjustable cup tools to properly tension
the bearings. The bearings are not sealed, but they're easily
accessible for cleaning and lubrication.Also see bottom bracket
adjustable cup: The left-hand cup in a bottom bracket of a
bicycle, used in adjusting the bottom bracket bearings and removed
during bottom bracket overhaul. The other cup is the fixed cup.
adjustable off-idle air bleed:
Some emissions-era Rochester carburetors have a separate air
passage to bleed air past an adjustment screw into the idle system.
this screw is preset by the factory to produce precise off-idle
air/fuel mixture ratios to meet emission-control requirements.
adjustable part throttle: (APT) a supplementary circuit on some
carburetors that can be adjusted to control part-throttle mixtures
more accurately than a fixed orifice. The APT detours around the
main jet, going directly from the float bowl to the discharge
nozzle feed well. adjustable-pitch propeller:See propeller
adjustable-port proportioning valve: Air and fuel valves for oil
or gas burners, motor operated in unison by automatic
temperature-control equipment. adjustable rocker arm: A type of
rocker arm with an adjusting nut that can be tightened or loosened
to adjust valve lash. adjustable shock:See adjustable shocks
adjustable shock absorbers: Shocks with adjustable jounce and
rebound characteristics can be stiffened to compensate for wear or
to fine tune a suspension for a particular application such as
rough roads, heavy loads, or racing. adjustable shocks: Shock
absorbers which can compensate for varying needs of stiffness or
softness. Manual types (especially on motorcycles) require that you
physically make the adjustment from one level to another. Automatic
types are controlled by a computer as it senses particular changes
in road
condition.
adjustable spanner: British term for adjustable wrench.
adjustable steering:See height adjustable steering column
adjustable steering column:See height adjustable steering
column
adjustable variable exhaust port: A device used on two-stroke
engines which automatically alters or varies the exhaust port size.
adjustable wrench: A crescent wrench or pipe wrench. A tool which
has a fixed jaw and a movable jaw which is controlled by a spiral
gear. It is used to install or remove bolts and nuts of various
sizes. The wrench itself comes in a variety of lengths and jaw
sizes. A crescent wrench has smooth jaws while a pipe wrench has
serrated jaws. British term is "adjustable spanner." adjusted:See
factory adjusted
adjuster: A device for moving something into the correct
position or into a different position such as a seat adjuster.Also
see automatic adjuster
automatic wear adjuster brake adjuster horizontal adjuster jet
adjuster ride-height adjuster
adjuster cam: A device for moving the shoes on drum brakes
closer to the drum itself so that there is less travel when the
brakes are applied. adjusting:Also see electrode adjusting tool
headlight adjusting screw self-adjusting
adjusting gage:See adjusting gauge
adjusting gauge: A tool used to determine the small distance
between two parts so that they can be brought within
specifications. adjusting screw: A small screw usually found on
carburetors, brakes, or headlights which change the way something
operates, such as increasing or decreasing the amount of fuel
entering the engine; or changing the idle speed; or tightening up
the brakes; or changing the setting on rocker arms; or the level of
the headlights.Also see headlight adjusting screw tappet adjusting
screw valve adjusting screw
adjusting shim: A thin washer or plate which reduces or
increases the clearance between two components (depending upon
where they are placed). While some valves are adjusted by screws on
the rocker arm, others are set by inserting a shim to make the same
adjustment.
adjusting sleeve: A small threaded cylinder on the end of the
tie rod which shortens or lengthens the rod to make changes in the
toe-in and toe-out. adjusting spanner:See brake adjusting
spanner
adjusting tool:Also see brake adjusting tool electrode adjusting
tool
adjusting wrench:See brake adjusting wrench
adjustment: [1] Changing or modifying the position or alignment
of two components. [2] The distance of travel that a component
has.Also see fore and aft adjustment idle mixture adjustment screw
idle speed adjustment
adjustment screw:See idle mixture adjustment screw
Adler: The brand name of a vehicle. With required application
the 1925-48 models are classic cars. admiralty brass:See Tobin
bronze
admission: The point in the working cycles of a steam or
internal-combustion engine at which the intake valve allows entry
of the working fluid into the cylinder. admittance:
Property which permits the flow of current under the action of a
potential difference. The reciprocal of impedance. a-dos:See
dos-a-dos
Adrastea: A tiny natural satellite of Jupiter, discovered in
1979 by the Voyager 2 mission. Distance from the planet 129,000 km;
diameter 24 km. A-drier:See a-dryer
ADS: Abbreviation for air data system. A-dryer: A paint dryer
which has the heating elements below the paint drying line. ADS:
Acronym for "Association of Diesel Specialists". adsorbent:
Substance with the property to hold molecules of fluids without
causing a chemical or physical change. adsorption: The bonding that
takes place when a gas or vapor comes into contact with a solid.
The opposite is desorption. adsorption canister:See activated
carbon canister
adularescence:
A milky or bluish sheen shown by moonstone. advance: [1] The act
of changing the ignition timing so that the spark occurs earlier in
the cycle. The opposite is retard. [2] It may refer to the device
which makes this adjustment. [3] The length of railway track beyond
a signal which is covered by that signalAlso see angle of advance
automatic advance centrifugal advance electronic spark advance
ignition advance mechanical advance ported vacuum advance spark
advance speed control vacuum advance vacuum advance
advance capsule:See vacuum advance
advance curve: As the speed of the engine increases the ignition
advance also increases. On paper, a pattern is drawn as a curve to
represent this relationship. advanced: [1] A condition in which
something occurs early. [2] A product which is on the cutting edge
of technology and shows the latest in new ideas and concepts.
advanced gas-cooled reactor: (AGR) Carbon-dioxide-cooled,
graphite-moderated reactor using slightly enriched uranium oxide
fuel clad in stainless steel, in use in the UK. advanced
intelligent network: A form of intelligent network, developed in
the US from 1987 onward, in which signalling, software, and
accounting procedures are designed to allow service providers to
compete freely for network users' business.
advanced mobile phone system: (AMPS) The American forerunner of
the UK total access communications system. Developed by Bell in
1978, AMPS like TACS, is an analog cellular system using frequency
modulation. advanced rim taper: A rim where both bead seats are
tapered 5. advance mechanism:See vacuum advance mechanism
advance metal: Copper-base alloy with 45% nickel. advance
spring: A small spring which pulls the advance weight back.See
picture in advance weight
advance unit:See vacuum advance unit
advance weight: One of two small weights located in a
centrifugal advance assembly.
advance workings:
In flat seams, mining in which the whole face is carried
forward, no support pillars being left. advantage ratio: Ratio
between the radiation dosage received at any point in a nuclear
reactor and that of a reference position. advection: The
transference of any quantity by horizontal motion of the air.
advection fog: Fog produced by the advection of warm moist air
across cold ground. advection layer: The region immediately
adjacent to the event horizon where matter is being continuously
pulled into the black hole. advertising: A colloquial term for a
police car with its emergency lights flashing. Ae: The
transformation temperature at equilibrium of the phase changes in
iron and steel, subscripts indicating the designated change. Also
called A. AE: Abbreviation for automatic exposure. AEA: Acronym for
"Automotive Electric Association" or "Automotive Electronic
Association". aeolian tone: A musical note set up by vortex action
on a stretched string when it is placed in a stream of air.Also
see
Strouhal number
aeolotropic: Having physical properties which vary with
direction or position.Also see anisotropic
AERA: Acronym for "Automotive Engine Rebuilders Association."
aeration: A foaming of a liquid because air has been introduced
into the fluid. When it occurs in certain liquids, it decreases the
efficiency of the liquid. aeration test burner: (ATB) Burner for
measuring the combustion characteristics of commercial gases.
aerial: British term for antenna.Also see retractable aerial whip
aerial
aerial bunched conductors: (ABC) Method of power transmission
where the three conductors are twisted into a thicker insulated
cable. More expensive but better at surviving blizzard conditions
than normal separate conductors. aerial fog: Fog caused by exposure
of portions of the film to air in the processing machine. aerial
radiometric surveying: Use of low-flying aircraft to measure
gamma-ray intensity due to natural radioactive emissions or
radioactive contamination over large areas. Scintillators are used
with photomultipliers whose signals are fed to multichannel
analyzers to distinguish the energies of the gamma rays
received from a wide area; typically 90% of the gamma rays can
be recorded from an area with linear dimensions about five times
the aircraft's height above the ground. Also called airborne
radiometric surveying. aerial ropeway: An apparatus for the
overhead transport of materials in carriers running along an
overhead cable or cables supported on towers. aerial surveying: A
process of surveying by photographs taken from the air, the
photographs being of two types: 1. those giving a vertical or plan
view; 2. those giving an oblique or bird's-eye view.Also see
vertical aerial photograph oblique aerial photograph
AERO: Abbreviation for "Air Education and Recreation
Organization" in the UK. aero-: Prefix from Greek aer () indicating
"air". aero-acoustics: Branch of acoustics that treats sound
generation and transmission by fluid flow. aerobar: An extension to
bicycle handlebars which project forward to give the rider an
alternate riding position and a lower, more aerodynamic position.
His elbows rest in the pads while he grabs the upright ends of the
bars. Aerobars were popularized by triathletes and Greg LeMond.
aerobars: Sometimes referred to as Tri bars. Aerobars
popularized by triathletes and Greg LeMond, are attached to
handlebars in order to provide a rider with a lower, more
aerodynamic position. aerobic sealer: A substance (such as room
temperature vulcanizing (RTV), a common silicone rubber sealing
compound) that requires the presence of oxygen to hold parts
together.Also see anaerobic sealer
aerodynamic: The efficient flow of air around an object.
aerodynamic balance: [1] A balance, usually but not necessarily in
a wind tunnel, designed for measuring aerodynamic forces or
moments. [2] Means for balancing air loads on flying control
surfaces, so that the pilot need not exert excessive force,
particularly as speed increases. The principle is to use
aerodynamic forces, either directly on a portion of the control
surface ahead of the hinge line or indirectly through a small
auxiliary surface with a powerful moment arm, to counterbalance the
main airloads. An example of the first is the horn balance, and of
the second the balance tab. aerodynamic braking: Use of a planet's
atmosphere to reduce the speed of space vehicles. aerodynamic
center: The point about which the pitching moment coefficient is
constant for a range of airfoil incidence. aerodynamic coefficient:
A non-dimensional measure of aerodynamic force, pressure, or moment
that expresses the characteristics of a particular shape at a given
incidence to the airflow. Typically the lift coefficient is given
by CL=L/VS, where L is the lift, is the air density, V is the air
speed, and S is a typical area of
the body (e.g., wing area). Similarly for drag coefficient.
aerodynamic damping: The suppression of oscillations by the
inherent stability of a aircraft or of its control surfaces.
aerodynamic drag: The resistance of the air to forward movement,
sometimes called "air resistance." This is a factor of the shape of
the vehicle (drag coefficient and frontal area), the objects which
stick out (i.e., mirrors, mufflers, bumpers), the amount of
turbulence at the rear of the vehicle, the nature of the vehicle's
skin surface, and the amount of air going through the vehicle for
cooling and ventilation. The faster you go, the greater the air
friction (air friction = velocity x velocity). The faster you go,
the greater the amount of power needed to overcome this drag (power
= velocity x velocity x velocity). aerodynamic heating: The heating
of a vehicle passing through the atmosphere, caused by friction and
compression of air (or other gas). aerodynamics: The study of the
flow of air as it passes over and around a moving object as well as
the forces which the air makes on the object. An airplane, for
instance, needs positive lift to get it airborne and negative lift
to help it land. Thus the shape of a land vehicle (car, bicycle,
etc.) either promotes positive or negative lift. Race cars may use
spoilers and wings (air foils) to control lift. In vehicle design,
the airflow is monitored in a wind tunnel. As well, aerodynamics
also studies the most efficient shapes for increased speed and fuel
economy. aerodynamic sound:See fl