Fr.: glace sale
Interstellar ice grains with graphite, silicates, or other chemical compounds adsorbed on their surfaces.
dirty iceball model
model-e golule-ye yax
Fr.: modèle de la boule de glace sale
A model for a → cometary nucleus proposed by Fred Whipple (1950-51), according to which the nucleus is a solid body (a few kilometers across) made up of various → ices (→ frozen water, → methane, → ammonia, → carbon dioxide, and → hydrogen cyanide) in which → dust is embedded. Dust particles are liberated when the ices vaporize as the → comet approaches the → Sun, and they get blown away by → solar radiation pressure, often forming impressive, gently curved → dust tails.
A prefix meaning "lack of, not" (e.g. dishonest); "do the opposite of" (e.g. disallow); "apart, away" (e.g. discard); before f, dif-; before some consonants (b, d, l, m, n, r, s, v, and sometimes g and j) di-.
From O.Fr. des-, from L. dis- "apart," from PIE *dis- "apart, asunder" (cf. O.E. te-, O.S. ti-, O.H.G. ze-, Ger. zer-). The PIE root is a secondary form of *dwis- and is thus related to L. → bis "twice."
Vâ- prefix denoting "separation; repetition; open; reversal, opposition; off; away," variant of bâz-, from Mid.Pers. abâz-, apâc-; O.Pers. apa- [pref.] "away, from;" Av. apa- [pref.] "away, from," apaš [adv.] "toward the back;" cf. Skt. ápāñc "situated behind."
Computers: To cancel the assignment of a particular resource to a user.
The act of disallocating or the state of being disallocated.
The act or state of disapproving; a condemnatory feeling, look, or utterance.
To withhold approval from; decline to sanction.
The removal or transference of an electric charge, as by the
conversion of chemical energy to electrical energy.
From M.E. deschargen, from O.Fr. deschargier "unload," from L.L. discarricare, from → dis- "do the opposite of" + carricare "to load a cart," from carrus "cart."
The quality or state of being → disciplinary.
1) A branch of learning or instruction.
M.E., from M.Fr. discipline, descepline, from L. disciplina literally "teaching, instruction," from discipulus "pupil, student, follower," from dis- + cipere, combining form of capere "to take," → concept, + -ulus, → -ule.
Hâvešân, from hâveš "disciple, pupil," Mid.Pers. hâvišt "disciple, pupil;" Av. hāvišta- "disciple, pupil," + -ân a suffix denoting "group, order, system."
A break in sequence or continuity of anything. → Balmer discontinuity
padvâridan, kašf kardan
To find (something previously unseen or unknown) after study or search.
Padvâridan "to uncover," infinitive from padvâr, from prefix pad- "against, contrary, opposite to," variants pat-, pâd-, → anti-, + vâr- "to cover;" cf. Av. vār- "to cover;" Mid.Pers. (with prefix *uz-) uzvâr- "to interprete, uncover, grasp," Pers. hozvâr(eš) "interpretation;" Khotanese (+ *ui-) gvir- "to be revealed;" Choresmian (+ *apa-) bw'rg- "to uncover;" Pers. barg "cover, clothes;" šalvâr "trousers" (Cheung, 2007).
padvâr, padvâreš, kašf
The act or an instance of discovering. Something discovered.
Verbal noun of → discover.
Fr.: écart, désaccord
Divergence or disagreement, as between facts, claims, or calculations.
From L. discrepantia, from discrepantem, pr.p. of discrepare "sound differently, differ," from → dis- "apart, off" + crepare "to rattle, crack."
Nâhamxâni, from nâ- "non, un-," → a-, + hamxâni "siniging together," from ham- "together," → com-, + xâni, from xân stem of xândan "to sing; to read; to call," Mid.Pers. xwân- "to resound; to call," Av. xvan- "to sound," Proto-Iranian *huan- "to call;" cf. Skt. svan-, sváranti "to sound, make a sound, sing;" L. sonus "sound," sonare "to sound;" O.E. swinn "music, song," PIE base *suen- "to sound" (Cheung 2007).
gosasté, jodâ (#)
Apart or detached from others; separate; distinct. Composed of distinct or discontinuous elements.
Gosasté "broken, broken off," p.p. of gosastan "to break, split,"
Mid.Pers. wisistan "to break, split," Av. saed- "to split,"
asista- "unsplit, unharmed," Skt. chid- "to split, break, cut off,"
Gk. skhizein "to split," L. scindere "to split;"
PIE stem *skei- "to split, cut."
discrete absorption component (DAC)
hamne-ye daršami-ye gosasté
Fr.: composante d'absorption discrète
The rapid, systematic changes in the absorption parts of the → P Cygni profiles of the ultraviolet → resonance lines (Si IV, C IV, and N V) observed in a majority of massive → hot stars. DACs are typically seen to accelerate to the → blue wing of the profile over a few days, becoming narrower as they approach the → terminal velocity.
dâdehâ-ye gosasté (#)
Fr.: données discrètes
Data that can only take a small set of particular values, usually whole numbers. For instance, number of children in a family cannot be 2.4, since parents cannot actually have 2.4 children. → continuous data.
discrete radio source
xan-e râdioyi-ye jodâ
Fr.: radiosource discrète
A localized source on the celestial sphere that can be observationally separated at radio wavelengths from its background emission.
Fr.: spectre discret
A spectrum in which the component wavelengths (and wave numbers and frequencies) constitute a discrete sequence of values (finite or infinite in number) rather than a continuum of values.