apertometer
An instrument designed to measure the numerical aperture of a lens or objective of a microscope.
Entries starting with A
381 entries.
aperture
A hole which restricts the diameter of the lightpath through one plane in an optical system.
apex
The highest or the greatest part of something, especially forming a point.
aphanite
Certain dark igneous rocks having grain so fine that the individual crystals cannot be seen with the naked eye.
aphanitic
adjectiveMining and extraction
Pertaining to aphanites, igneous rocks composed of microscopic mineral crystals (fine grains too small to be visible to the naked eye.
aphicide
Any pesticide intended to kill aphids
API donut
nounAutomotive
An information table found on cans of motor oil, conforming to U.S. standards, which indicates the weight (viscosity) and type of oil. The central circle provides the oil viscosity rating (ie. 10W50), while the upper annulus section provides the oil type (ie. SP).
apidictor
An instrument which measures and records the sounds in a beehive.
aplanat
A lens that has been corrected for spherical aberration and coma in order to produce a rectilinear image.
aplanatic
adjectiveOptics and imaging
Free from, or corrected for, spherical aberration and chromatic aberration
aplanatism
Lack of spherical aberration.
apochromat
A kind of lens corrected for chromatic and spherical aberration.
apochromatic
adjectiveOptics and imaging
Corrected for both chromatic aberration and spherical aberration
apochromatism
Freedom from both chromatic aberration and spherical aberration.
Apollo
A United States space program, and the vehicles it created, used for human travel to the moon.
app
An application (program), especially a small one designed for a mobile device.
apparatus
A vehicle used for emergency response.
Apperson
nameAutomotive
A former American motorcar manufacturer.
apple seed
The seed of the fruit of the Malus domestica (apple) tree or other tree of the genus Malus.
approach
The way an aircraft comes in to land at an airport.
AprilTag
nounRobotics
A type of tag consisting of a grid of black and white squares, used in robotics and computer vision applications.
apron
The paved area of an airport, especially the area where aircraft park away from a terminal.
apron flashing
nounConstruction
A flashing located at the juncture of the top of a sloped roof and a vertical wall, chimney or steeper-sloped roof.
aquacultural
adjectiveAgricultural equipment
Of or pertaining to aquaculture.
aquaculturist
A person involved in aquaculture.
aquafeed
Any feed for aquatic organisms as part of aquaculture.
aquaplane
verbAutomotive
Of a car or other road vehicle: to lose traction with the road due to the vehicle's tyres sliding on a film of water on the road.
aquaplaning
nounAutomotive
The loss of contact with the road because of surface water; the act of aquaplaning.
arability
The capacity for land to produce or support vegetation.
arable
adjectiveAgricultural equipment
Able to be plowed or tilled, capable of growing crops (traditionally contrasted with pasturable lands such as heaths).
Arago spot
A bright point that appears at the centre of a circular object's shadow due to Fresnel diffraction.
arbiter
A component in circuitry that allocates scarce resources.
arc blast
An explosion produced by the extreme heat of an uncontrolled high-energy electric arc.
arc fault
An undesired and uncontrolled electric arc from one conductor through the air (or other gas) to a conductor at ground potential or a different voltage phase.
arc flash
The extremely intense light and heat produced by a high-energy electric arc.
arc-fault circuit interrupter
A type of circuit breaker that detects signs of potentially-dangerous arcing on downstream wiring and shuts off power to the affected branch circuit to reduce the risk of a fire.
arch
An architecture; a computer architecture or instruction set architecture.
archaeometallurgy
nounMetallurgy
The study of the prehistory of metal extraction and working
architectural concrete
nounConstruction
Concrete that is exposed to view because it forms part of a surface, and may therefore need special attention given to its appearance.
architectural panel
nounConstruction
A metal roof panel, typically a double standing seam or batten seam; usually requires solid decking underneath and relies of slope to shed water
architectural shingle
nounConstruction
An asphalt shingle that provides a three-dimensional appearance.
arcover
The unwanted arcing of electricity from one component to another, caused for example by the presence of contaminants.
arcwall machine
A mobile cutting machine that can cut horizontally into walls.
area rule
A rule stating that an airplane designed with the same cross-sectional area distribution in the longitudinal direction as the Sears-Haack body generates the same wave drag as this body, largely independent of the actual shape; used in aerodynamics to reduce drag, typically by narrowing the fuselage at the wing roots.
arithmetic logic unit
The section of a CPU that performs calculations and logical operations.
Armstrong oscillator
An electronic oscillator circuit which uses an inductor and capacitor to generate an oscillation.
ARNK
An unknown or empty sector of an itinerary.
aromatization
The conversion of aliphatic components of petroleum into aromatic compounds as part of the refining process.
Artemis
A United States space program, and the associated vehicles, used for human travel to the Moon in the 2020s. (See Artemis program on Wikipedia.)
artery
A major transit corridor in a system of roads, rivers, or railway lines.
article of extraordinary value
A transported item with a value exceeding 100 USD per imperial pound.
artificial horizon
An instrument that displays the pitch and roll of an aircraft in flight by comparing its attitude to a gyroscopically-maintained indication of the flat horizon line.
as-built
nounConstruction
A drawing showing how a project was actually built as opposed to how it was intended to be built.
ashlaring
nounCarpentry
The short upright pieces between the floor beams and rafters in garrets.
Asian utility vehicle
Any of various motor vehicles that are tailored to East Asian and Southeast Asian markets and are variously similar to or identical with basic utility vehicles, sport utility vehicles, or minivans, depending on the instance.
ASIC
Acronym of application-specific integrated circuit.
aspect
nounRail equipment
The visual indication of railway signal as displayed to the driver. With three-aspect colour light signals this would be red, yellow or green, and on four-aspect signals, double-yellow also; a two-aspect signal displays red or green.
aspecular
adjectiveOptics and imaging
Subtended at the origin by the specular axis and the axis of the receiver.
asphalt emulsion
nounConstruction
A mixture of asphalt particles and emulsifying agent, such as bentonite clay and water.
asphalt shingle
A shingle manufactured by coating a reinforcing material (felt or fibrous glass mat) with asphalt and having mineral granules on the side exposed to the weather.