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And Gate

A digital logic gate that must have all of its inputs high to produce an output.

Aneroid Bellows

An accordion-shaped temperature sensor charged with a small amount of volatile liquid. Temperature change causes the bellows to contract or expand, which, in turn, opens or closes a switch, such as a thermostat.

Angle Block

A cylinder block that does not have a deck at 90 degrees to the cylinder.

Angle Mill

A machining operation to mill the deck surface at a shallow angle on the exhaust side of the engine block in order to increase the compression ratio by decreasing the combustion chamber volume.

Angle Plug Head

A cylinder head having spark plugs that are angled toward the exhaust valves.

Angstrom (a0)

The unit used to depict the wavelength of light or other electromagnetic radiation. Two hundred and fifty million angstroms equal one inch.

Anion

A negative ion. Alkali, molten carbonate and solid oxide fuel cells are "anion-mobile" cells .

Anneal

1. A heating and cooling of steel in the solid state, usually requiring gradual cooling. 2. To heat aluminum to 640 degrees F (338 degrees C) and then cool it to 450 degrees F (232 degrees C) to soften it to make it ductile.

Annealing

A heat-treatment process to reduce hardness or brittleness, relieve stresses, improve machinability, facilitate cold working, or produce a desired microstructure or property.

Annual Percentage Rate (APR)

The cost of credit expressed as a yearly rate. The result is derived from an equation that calculates several figures, including the total amount financed, the finance charges, and the term of the loan. Usually not the same as the interest rate. Under federal law, all consumer loans must disclose the Annual Percentage Rate.

Annulus

Any type of ring gear, including the ring part of the ring and pinion in the rear end, and the gears in the planetary gear set of an automatic transmission.

Anode

[1] The positively charged electrode in an electrolytic cell toward which current flows.[2] In a fuel cell it is where the fuel reacts or "Oxidizes", and releases electrons.

Anodize

A protective oxide coating to a metal surface using the metal as the anode in an electrical cell and allowing an electrolyte to act upon it.

Ansi

An acronym for the American National Standards Institute.

Ant

An acronym for antenna.

Antenna

A wire or other conductive metallic structure used for radiating or receiving electromagnetic signals, such as those for radio, television, or radar.

Antenna Trimmer

A method used to calibrate the antenna for an AM radio.

Anti-Backfire Valve

A valve that is used in the air-injection system to prevent backfiring in the exhaust system during deceleration.

Anti-Drive

A suspension geometry that resists a vehicle's tendency to drop or dive on the front springs when braking.

Anti-Foam Agent

An additive that reduces foaming caused by the churning action of the crankshaft in the engine oil.