Fr.: ligne d'écoulement
Same as → streamline.
Fr.: tube d'écoulement
Same as → stream tube.
Fr.: aptitude à s'écouler, coulabilité
The ability of a body of matter (liquid, gas, loose particulate solid) to flow.
Tacandegi, from tacandé (originally tacandag), agent noun of tacidan, → flow, + noun suffix -i.
oftâxizidan, oftâxiz kardan (#)
To change continually; to shift back and forth; vary irregularly; to rise and fall in or as if in waves.
From L. fluctuationem (nom. fluctuatio), from fluctuare "to undulate," from fluctus "wave," from p.p. of fluere "to flow."
Verbal form of oftâxiz, → fluctuation.
Continual rise and fall.
Verbal noun of → fluctuate.
Oftâxiz "fall and rise," from oft "fall" stem of oftâdan "to fall" (Mid.Pers. opastan "to fall," patet "falls;" Av. pat- " to fly, fall, rush," patarəta- "winged;" cf. Skt. patati "he flies, falls," pátra- "wing, feather, leaf;" Gk. piptein "to fall," pterux "wing;" L. penna "feather, wing;" O.E. feðer "feather;" PIE base *pet- "to fly, rush") + -â- interfix + xiz present stem of xâstan, xizidan "to rise, get up" (Mid.Pers. xyz- "to stand up, rise;" Proto-Iranian *xiz- "to rise, ascend; increase").
1) Light, downy particles, as of cotton.
Apparently a variant of floow "wooly substance, down, nap," perhaps from Flemish vluwe, from Fr. velu "shaggy, hairy," from L. vellus "fleece," or L. villus "tuft of hair" (Online Etymology Dictionary).
Kork "down, soft wool, fluff," of unknown etymology.
Fr.: duveteux, bouffant
Of, resembling, or covered with fluff.
Korkvâr "resembling fluff," with -vâr, a suffix of possession, similarity, and aptitude (e.g., omidvâr, sezâvâr, sugvâr, šâhvâr, gušvâr), → -oid; korki adj. with -i.
fluffy dust grain
dâne-ye qobâr-e korkvâr
Fr.: grain de poussière duveteux
An aggregate of small particles loosely stuck together. Same as → porous dust grain.
A continuous, amorphous substance whose molecules move freely past one another and that has the tendency to assume the shape of its container; collective term for liquids and gases.
From L. fluidus "fluid, flowing," from fluere "to flow;" → flux.
Šârré, from šârr, → flux.
Fr.: dynamique des fluides
The branch of → fluid mechanics that deals with the movement of gases and liquids.
Fr.: mécanique des fluides
The ability of a substance to flow; reciprocal of → viscosity.
A type of → luminescence in which photons of lower energy are emitted as the result of absorption of energy by an atom or molecule from other radiation. The phenomenon lasts as long as the stimulus responsible for it is present.
Coined by English mathematician and physicist Sir George G. Stokes (1819-1903) from fluor-, from → fluorspar, + → -escence, a suffix of nouns denoting action or process, change, state or condition, etc.
Possessing the property of → fluorescence.
Fr.: ampoule fluorescente
A compound (salt of hydrofluoric acid) containing → fluorine.
Gaseous chemical element; symbol F. It is the most reactive of all chemical elements. It is a yellowish, corrosive gas, which reacts with most organic and inorganic substances. → Atomic number 9; → atomic weight 18.9984; → melting point -219.62 °C; → boiling point -188.14 °C; → density 1.696 grams per liter at STP; → valence -1. Fluorine and its compounds are used in producing uranium (from the → hexafluoride) and more than 100 commercial fluorochemicals, including many high-temperature plastics.
From L. fluere "flow, → flux," since fluorspar (CaF2) was used as a flux in metallurgy because of its low melting point. It was discovered in hydrofluoric acid by the Swedish pharmacist and chemist Carl-Wilhelm Scheele in 1771 but it was not isolated until 1886 by the French pharmacist and chemist Ferdinand Moisson.
Fr.: fluorite, fluorine
Same as → fluorite.
From fluor-, → fluorine, + spar "a crystalline mineral."