An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

Same as → stream tube.

→ flow; → tube.

A device for amplifying faint images by electronic means. Electrons, released when the incident radiation forms a pattern on a photocathode, are accelerated by a magnetic field so that they form a second, brighter image when they strike a phosphor screen.

→ image; → tube.

A → device used to → measure the → velocity of a flowing → fluid. The Pitot tube is used on → aircrafts to determine their → speed. It is also used to meaure water speed of a boat as well as liquid, air, and gas velocities in industrial applications. It is a small tube that has two holes on it. The front hole is placed in the airstream to measure the → stagnation pressure. The side hole measures the → static pressure. The difference between these pressures gives the → dynamic pressure, which can be used to calculate airspeed. See also the → Bernoulli equation.

Named after the French inventor Henri Pitot (1695-1771), a hyraulic engineer; → tube.

A pipe-shaped volume obtained by drawing → streamlines through every point of a closed curve in the fluid. Since the stream tube is bounded on all sides by streamlines and since, by definition, there can be no velocity across a streamline, no fluid may enter or leave a stream tube, except through its ends. See also → stream filament.

→ stream; → tube.

1) A long hollow cylinder of metal, glass, rubber, or other material used to transport or contain liquids or gases.
2) An electronic device in which electrons operate in a gas or in vacuo inside a closed envelope.

M.E., from M.Fr. tube, from L. tubus "tube, pipe," of unknown origin.

Lulé "tube, pipe; roll," dialectal Lori, Laki lil, Laki lul "wanderer;" Hamadâni lul "spiral, coil."

Same as → flow tube.

→ tube; → tube.

Bundles of lines of electrical intensity into which the vector field of electrical force can be divided. Same as tube of force, field tube.

→ tube; → flux.

A → device used to → measure the → quantity of → fluid  → flowing through a → pipe.

Named after Italian physicist Giovanni Battista Venturi (1746-1822); → tube