absorption tower: A vertical tube in which a rising gas is partially absorbed by a liquid in the form of falling droplets. Also known as absorption column.
absorption trench: A trench containing coarse aggregate about a distribution tile pipe through which septic-tank effluent may move beneath earth.
absorption-emission pyrometer: A thermometer for determining gas temperature from measurement of the radiation emitted by a calibrated reference source before and after this radiation has passed through and been partially absorbed by the gas.
absorptivity: The ratio of the radiation absorbed by a surface to the total radiation incident on the surface.
Abt track: One of the cogged rails used for railroad tracking in mountains and so arranged that the cogs are not opposite one another on any pair of rails.
abutment: A surface or mass provided to withstand thrust, for example, end supports of an arch or a bridge.
abutting joint: A joint which connects two pieces of wood in such a way that the direction of the grain in one piece is angled (usually at 90°) with respect to the grain in the other.
abutting tenons: Two tenons inserted into a common mortise from opposite sides so that they contact.
accelerated aging: Hastening the deterioration of a product by a laboratory procedure in order to determine long-range storage and use characteristics.
accelerated life test: Operation of a device, circuit, or system above maximum ratings to produce premature failure, used to estimate normal operating life.
accelerated weathering: A laboratory test used to determine, in a short period of time, the resistance of a paint film or other exposed surface to weathering.
accelerating incentive: NULL
acceleration: The rate of change of velocity with respect to time.
acceleration analysis: A mathematical technique, often done graphically, by which accelerations of parts of a mechanism are determined.