Ad

AD
Abbreviation of Anno Domini.
Ada
A large, complex, block-structured computer language aimed primarily at embedded applications.
Adakane 12
Another name for Dodecane.
Adamantane

C10H16

A colourless, crystalline compound with a camphor-like odour. It is a cycloalkane and also the simplest diamondoid.

Adaptation
The way living things have changed in order for them to live and survive in their environment.
Adapter
Any device or contrivance used or designed primarily to fit or adjust one thing to another.
Adaptive Differential Pulse Code Modulation
A compression technique which encodes the predictive residual instead of the original waveform signal so that the compression efficiency is improved by a predictive gain.
Adaptive Learning
Learning where a system programs itself by adjusting weights or strengths until it produces the desired output.
Adaptive Optics
A technique that uses deformable mirrors on a telescope to correct the blurring caused by turbulence in the atmosphere.
Adaptive Transform Acoustic Coding
A lossy audio coding system based on psychoacoustic principles.
ADC
Abbreviation of Analogue to Digital converter.
Adcock Aerial
An Adcock aerial is a radio aerial system consisting of two vertical open-spaced dipoles with screened horizontal connections.
Addendum
That portion of a gear tooth that extends from the pitch circle to the outside diameter.
Addition
The operation of finding the sum of two or more quantities.
Addition Compound
Compound contains two or more simpler compounds that can be packed in a definite ratio into a crystal.
Addition of Ordinates
A graphing technique where two or more functions are independently plotted on the same graph, then their y-coordinates are added together at each point to form the new graph.
Addition Reaction
A chemical reaction in which two atoms or groups of atoms are added across a double bond.
Additive
A material added to another, usually in small amounts, to impart or enhance desirable properties or to suppress undesirable properties.
Additive Colour System
An additive colour system is a colour reproduction system in which an image is displayed by mixing appropriate amounts of red, green and blue light, as for example in a cathode-ray tube.
Additive Identity
The additive identity is the number zero, because zero will not change a number when added to it: a + 0 = a for all a.
Additive Inverse
The addition of number and it′s additive inverse is zero. The additive inverse of a number a is -a, also known as the opposite of a, such that a + (-a) = 0. For example, 1 + (-1) = 0.
Additive Primaries
Red, green, and blue are the primary colours of light from which all other colours can be made.
Address
The binary number that represents the collection of binary signals used by memory hardware to determine which memory register to access.
Address Mask
A bit mask used to select bits from an Internet address for subnet addressing.
Address Resolution
Conversion of an IP Address to the corresponding low-level physical address.
Adenosine Diphosphate

C10H16N5O13P3

An important organic compound in metabolism and is essential to the flow of energy in living cells.

Adenosine Triphosphate

C10H15N5O10P2

A nucleoside triphosphate used in cells as a coenzyme.

Adhere
To stick or be glued to something.
Adherence Index
Measure of the adherence of porcelain enamel and ceramic coatings to sheet metal.
Adhesion
The state in which two surfaces are held together by interfacial forces which may consist of valence forces or interlocking action.
Adhesive
A substance capable of holding material together by surface attachment.
Adhesive Failure
A rupture of adhesive bond that appears to be a separation at the adhesive-adherend interface.
Adhesive Force
The attractive force exerted on a liquid molecule by the molecules in the surface of the solid.
Adhesive Tape
A tape with a sticky substance on one side.
Adhesive Wear
Often referred to as galling, scuffing, scoring, or seizing.
Adiabat
A line on an indicator diagram that represents an adiabatic process.
Adiabatic Compression
Compressing a gas without removing or adding heat.
Adiabatic Cooling
A method in which paramagnetic salts are pre-cooled, and then demagnetized, thereby producing further cooling.
Adiabatic Efficiency
The efficiency with which work is done with respect to heat gains or losses.
Adiabatic Expansion
The expansion of a gas, vapour, or liquid stream from a higher pressure to a lower pressure, with no change in enthalpy.
Adiabatic Ionization Energy
The lowest energy required to remove an electron from an atom, ion, or molecule in the gas phase.
Adiabatic Line
A line on an indicator diagram that represents an adiabatic process.
Adiabatic Plasma
Part of plasma confinement system which involves particles where the orbit radius and orbit period are small compared to the characteristic scales of length and time.
Adiabatic Process
A process in which the system does not exchange heat with the surroundings.
Adiabatic Saturation Process
A process to determine absolute or relative humidity.
Adipic Acid
White crystalline solid used in the manufacture of nylon.
Adipocyte
An animal cell specialized for the storage of triacylglycerols.
Adipoyl Chloride

C6H8Cl2O2

A hazardous chemical that evolves HCl when reacted with water. Can be reacted with hexamethylene diamine to form nylon.

Adipoyl Dichloride
Alternative name for Adipoyl Chloride.
Adjacent Angles
Two angles are adjacent if they share a common vertex and have a common side between them.
Adjacent Signal
A signal whose fundamental frequency falls outside the 3 dB IF bandpass of a receiver, but whose spectral sidebands have the potential of being linearly transferred into the baseband of a receiver and causing interference.
Adjustable Bevel
A hand tool for marking angles.
Adjustable Resistor
A resistor whose value can be mechanically changed, usually by the use of a sliding contact.
Adjustable Rocker Arm
A type of rocker arm with an adjusting nut that can be tightened or loosened to adjust the valve to rocker arm gap.
Adjustable Shock Absorbers
Shocks with adjustable bump and rebound characteristics.
Adjustable Spanner
A tool which has a fixed jaw and a movable jaw which is controlled by a spiral gear.
Admiralty Mile
Equal to 1852m.
Admittance
The ratio of current to voltage, the reciprocal of impedance.
Adobe
Sun-dried brick used in places with warm, dry climates, such as Egypt and Mexico.
ADP
Abbreviation of Adenosine Diphosphate.
ADPCM
A compression technique which encodes the predictive residual instead of the original waveform signal so that the compression efficiency is improved by a predictive gain.
ADSL
Abbreviation of Asymmetric Digital Subscriber Line.
Adsorb
To collect molecules of a substance on a surface.
Adsorbate
A material that is adsorbed.
Adsorbent
A substance that collects molecules of another substance on its surface.
Adsorbent Filter
A filter medium primarily intended to hold soluble and insoluble contaminants on its surface by molecular adhesion.
Adsorbtion Chromatography
A technique for separating or analyzing mixtures that contain at least one component that is preferentially adsorbed by the stationary phase as it moves over it.
Adsorbtion Indicator
A substance that indicates an excess of a reactant in a precipitation reaction.
Adsorption
The adhesion of a thin film of liquid or gas to the surface of a solid substance.
Adulterants
Chemical impurities or substances that by law do not belong in a food, or pesticide.
Advanced Graphics Port
Slot on the PC motherboard for graphics cards, and the format of the cards themselves - more commonly known by its abbreviation AGP.
Advanced Research Projects Agency Network
More commonly known by it′s abbreviation ARPANET. Was the first operational packet switching network, and one of the networks that came to comprise the global Internet.
Advection
The transfer of matter such as water vapour or heat through the atmosphere as a result of horizontal movement of an air mass.
Adze
A woodworking tool with a sloping steel or iron blade square off a wooden handle.