degree of coherence
Fr.: degré de cohérence
The extent of → coherence of an → electromagnetic wave, as indicated by a → dimensionless number. Since interference takes place when waves are → coherent, using a → Young's experiment, the degree of coherence is measured from the → fringe → visibility, V. It is defined as the ratio V = (Imax - Imin) / (Imax + Imin), where Imax is the intensity at a maximum of the → interference pattern, and Imin is the intensity at a minimum of the interference pattern. The electromagnetic wave is considered to be highly coherent when the degree of coherence is about 1, incoherent for nearly zero values, and partially coherent for values between 0 and 1.
degree of freedom
daraje-ye âzâdi (#)
Fr.: degré de liberté
degree of ionization
daraje-ye yoneš (#)
Fr.: degré d'ionisation
The number of electrons a neutral atom has lost in an ionizing physical process (radiation, shock, collision). In spectroscopy, the degree of ionization is indicated by a Roman numeral following the symbol for the element. A neutral atom is indicated by the Roman numeral I, a singly ionized atom, one which has lost one electron, is indicated by II, and so on. Thus O VI indicates an oxygen atom which has lost five electrons.
degree of polarization
Fr.: degré de polarisation
The ratio of the intensity of polarized portion of light to the total intensity at a point in the beam.
degree of stability
Fr.: degré de stabilité
degree of vertex
Fr.: degré de vertex
The act or process or an instance of dehumanizing.
Verbal noun of → dehumanize.
To deprive of → human qualities or personality.
The smaller and outermost of Mars' two satellites. It measures 12.6 km in size, and orbits Mars every 30.2 hours at a distance of about 23,500 km. It was discovered by the American astronomer Asaph Hall in 1877.
In Gk. mythology, Deimos, meaning "fear, terror," is one of the sons of Ares (Mars) and Aphrodite (Venus).
Chemistry: A process in which all charged species are removed from
dâdâr-bâvari (#), izad-bâvari
1) Belief in the existence of a → God on the evidence of
→ reason and → nature only,
with rejection of supernatural revelation (distinguished from
dâdâr-bâvar (#), izad-bâvar
A person who believes in → deism.
1) izad (#); 2) izadgân
Fr.: 1) dieu, déesse; 2) divinité
1) A god or goddess.
M.E. deite, from O.Fr., from L.L. deitat- (nominative deitas), from L. dei- (combining form of deus "god") + -tat- "-ty," formed after L. divinitas "divinity."
Izad "god;" from Mid.Pers. yazêt "god; angel," izišn "performance of the religious rites, worship," yašt "worship, religious ceremony," yaštan "to venerate, to perform the religious ceremony;" O.Pers. yad- "to worship;" Av. yaz- "to sacrifice, worship, venerate," yazata- "deities," yasna- "religious rite" (Mod.Pers. jašn "feast"); Proto-Ir. *iaz- "to sacrifice, worship, venerate."
Fr.: opérateur del
In → vector calculus,
a vector → partial derivative represented by the symbol
→ nabla and defined in three dimensions to be:
From Gk. alphabet letter delta.
The amount of time by which an event is retarded.
From O.Fr. délaier, from dé-→ de- "away, from" + laiier, from laiss(i)er "to leave," from L. laxare "to loosen, release, set free."
Derang, from Mid.Pers. dirang, drang "delay, lateness; long, lasting," Av. drənj- "to fix, fasten, hold," Proto-Iranian *dra(n)j- "to fix, fasten, hold."
Fr.: temps de retard, délai
Same as → delay.
Fr.: neutrons retardés
Neutrons resulting from nuclear fission which are emitted with a measurable time delay. Delayed neutrons are responsible for the ability to control the rate at which power can rise in a reactor. → prompt neutrons.
delayed supernova explosion
oskaft-e bâderang-e abar-novâ, ~ ~ abar-now-axtar
Fr.: explosion retardée de supernova
A mechanism predicted by theoretical models of → supernova explosion that operates after the → supernova shock fails to deliver a → prompt supernova explosion. The delayed supernova explosion mechanism assumes that a few tenth of a second after the → iron core collapse, the supernova shock is stalled due to energy dissipation. The material between the → protoneutron star and the stalled shock is mainly disintegrated into neutrons and protons due to the high temperatures (a few MeV) in this region. As the → neutrinos coming from the protoneutron star run through this material, a fraction of the neutrinos are captured by the → nucleons, and their energy is deposited in the material. As a result, the material behind the shock is heated by the neutrinos. If this neutrino heating is efficient enough, the stalled shock can be reinvigorated to bring about a supernova explosion.
Fr.: barrer, rayer
To strike out or remove (something written or printed); cancel; erase.
L. deletus, p.p. of delere "destroy, blot out, efface," from delevi, fro delinere "to erase by smudging," from → de- "from, away" + linere "to smear, wipe."
Rušidan, from Kurd. rušê "to be wiped off through rubbing;" cf. Av. fra.uruxti- "destruction;" Wakhi riz-, rəz-/rəzd- "to tear apart, rip up a seam;" Yaghnobi ruc/ructa, rušta "to shave off the skin, skin off;" Proto-Ir. *rauj- "to break, bust" (Cheung 2007).
1) An act or instance of deleting. The state of being deleted. A deleted word, passage, etc.
Verbal noun from → delete.