Fr.: gaz rare
A gaseous chemical element that does not readily enter into chemical combination with other elements. Examples are helium, argon, krypton, xenon, and radon. Same as → inert gas.
Noble, from O.Fr. noble, from L. nobilis "well-known, famous, of superior birth," earlier gnobilis, literally "knowable," from gnoscere "to come to know" (Fr. connaître; Sp. conocer); cognate with Pers. šenâxtan "to know, discern, distinguish, be acquainted with;" Mid.Pers. šnâxtan, šnâs- "to know, recognize," dânistan "to know;" O.Pers./Av. xšnā- "to know, learn, come to know, recognize;" cf. Skt. jñā- "to recognize, know," jānāti "he knows;" Gk. gignoskein "to know, think, judge;" P.Gmc. *knoeanan; O.E. cnawan; E. know; Rus. znat "to know;" PIE base *gno- "to know;" → gas.
Gâz, → gas; huped "noble," from Mid.Pers. hupid "noble," from hu- "good, well" (Mid.Pers. hu-; O.Pers. hu- "good, well" (ukāra- "having good people"); Av. hu-, hū- "well, good, beautiful" (hu-kərp- "well-shapen," hūxta- "well spoken," hu-manah- "good-minded"); cf. Skt. su- "good" (svasti "well-being, good luck," sumánas- "good-minded," sūktá- "well spoken"); L. from Gk. eu "well," combining form of eus "good" (hu-gies "healthy"); Gallic su-; O.S. su-; Welsh hy-; PIE base *su-) + pid "father," variant of pidar; Mod.Pers. pedar "father" (O.Pers. pitā- "father;" Av. patar-; Skt. pitár-; Gk. pater; L. pater, O.H.G. fater).
Fr.: entaille, encoche
The end part of an → arrow having a notch for holding the bowstring.
M.E. nok(ke); of uncertain origin; cf. Swedish nock "notch;" also M.L.G. nokk, Dutch nok "tip of a sail."
Sufâr "the notch in the arrow which receives the string," also "the eye of needle," related to softan, sombidan "to pierce;" Mid.Pers. sôftan "to pierce, bore;" cf. Pashtu suray, Wakhi sərv "hole, cavity," Munji surv "hole," Yidgha surv, Kurd. sontin; Proto-Ir. sup, sub, sump, sumb "to pierce."
Fr.: nuage nocturne lumineux
The highest clouds in the Earth's atmosphere, at altitudes between 75 and 90 km. They resemble thin cirrus clouds with a bluish or silverish color, and are visible only during twilight.
Relating to or of the nature of a node.
Fr.: ligne des noeuds
The line connecting the ascending and descending nodes of an orbit.
Fr.: point nodal
Any of the two points on the → axis of a → lens system, such that if the → incident ray passes through one, travelling in a given direction, the → emergent ray passes the other in a parallel direction.
Fr.: regression nodale
For a ring inclined to the planet's equator, the points at which the ring crosses the equator (nodes) slowly move around the planet (regress) in a direction opposite to that of the ring's orbital motion. (Ellis et al., 2007, Planetary Ring Systems, Springer).
1) A point of zero → amplitude in a system of
→ stationary waves. See also
From L. nodus "knot;" cognate with necto "I bind," Skt. nahyati "binds, ties," Av. naska-, "bundle," Old Irish nascim "to bind," Old Norse knutr, Norwegian knut, Icelandic hnutur, O.E. cnotta, Modern E. knot, O.H.G. knotto, Ger. Knoten; PIE root *ned- "to bind, tie."
Gereh "knot," from Mid.Pers. grih "knot;" Sogdian γr'nš "knot, bond, joining;" Khotanese grantha- "knot;" cf. Skt. granthi- "knot."
mâh-e gerehi (#), ~ gowzahri (#)
Fr.: mois draconitique
The time interval between two successive passages of the Moon through its ascending node (27.212220 days, i.e., 27 days 5 hours 5 minutes 35.8 seconds). Nodical month is important for predicting eclipses. Also called → draconic month.
1) A small node, knot, or knob.
Fr.: théorème de Noether
A → symmetry in a physical system leads to a → conserved quantity. For example, symmetry under → translation corresponds to conservation of → momentum, symmetry under → rotation to conservation of → angular momentum, and symmetry in → time to conservation of → energy. The Noether symmetry theorem is a fundamental tool of modern theoretical physics and the calculus of variations, allowing to derive conserved quantities from the existence of variational symmetries.
Named in honor of the German-American woman mathematician Amalie Emmy Noether (1182-1935), who published the theorem in 1918 ("Invariante Variationsprobleme," Nachr. D. König. Gesellsch. D. Wiss. Zu Göttingen, Math-phys. Klasse 1918: 235-257).
1) The → random → fluctuations
that are always associated with a measurement that is repeated many times over.
Any unwanted disturbance, random or → systematic,
which contaminates the → signal from an object under study.
Noise, of obscure origin; it has been related to O.Fr. noise "uproar, brawl," apparently from L. nausea "disgust, annoyance," literally "seasickness." Alternatively the O.Fr. word is traced to L. noxia "hurting, injury, damage."
Nufé "noise," related to Mod.Pers. noyidan "to cry loud, lament," navidan, nâvidan "to lament," noyé, nôyah "plaint, mown," navâ "sound, song," (with prefix *uz-) zenudan, zenav-, zonudan "to wail," Ossetic niwyn/newun "to howl," O.Khotanese nuva- "to make a noise," Yaqnâvi nuyok "crying, howling," novva "sound," Shahmirzâdi nâv- "to cry; cf. Skt. nav- "to sound loudly, roar," náva- "show of joy or triumph;" L. nuntius "messenger," adnuntiare "to annoince;" Tocharian AB nu- "to roar, PIE *neu- "to shout".
Fr.: source de bruit
An electronic device designed to generate known amounts of radio noise in order to test and calibrate the receivers of radio telescopes.
Fr.: température de bruit
A means for specifying the noise generated as unwanted → electromagnetic radiation in a receiver system or one of its components. It is usually measured in terms of the equivalent temperature in a → Rayleigh-Jeans spectrum. Noise temperature is used mainly in radio astronomy.
Fr.: voltage de bruit
Fluctuations of electric potential in a physical system due to spontaneous disturbances in the system.
tavân-e ham-arz-e nufé
Fr.: puissance équivalente de bruit
A measure of the sensitivity of an electronic detector, defined as the power input to the detector that will create a signal to noise ratio of one for an integration time of half a second.
A set or system of names or terms assigned to objects or items in a particular science or art.
From Fr. nomenclature, from L. nomenclatura "calling of names," from nomenclator, variant of nomenculator "one who announces names, namer," from nomen, → name, + calator "caller," from calare "to call."
Nâmgozâri, from nâm, → name, + gozâri, verbal noun of gozâštan "to place, put; to allow, let," related to gozaštan "to pass, proceed, go over;" Mid.Pers. vitar- "to let pass, lead; to pass;" O.Pers. vitar- "to go across," viytarrayam "I put across;" Av. tar- "to cross over," vī-tərəta- "taken away, isolated;" ultimately Proto-Ir. *ui-tar-.
1) Of, pertaining to, or constituting a name or names, a noun or nouns.
From L. nominalis "pertaining to a name or names," from nomen "name," cognate with Pers. nâm, as below.
Nâmenâl, from nâmen, from O.Pers./Av.nâman-, → name, + suffix -al.
nominal focal length
derâzâ-ye kânuni-ye nâmenâl
Fr.: distance focale nominale
An approximate value of the → focal length, used for the classification of lenses, mirrors, or cameras, as opposed to the measured one.
Fr.: valeur nominale
The assigned, specified, or intended value of a quantity.