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

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 1279
scale height
  بلندی ِ مرپل   
bolandi-ye marpel

Fr.: hauteur d'échelle   

The height within which some parameter, such as pressure or density, decreases by a factor of e. For example, an atmospheric scale height of 100 km means that the value at 100 km is 1/e the value at the surface.

scale; → height.

scale in
  درون-مرپلیدن   
darun-marpelidan

Fr.:   

In computer science, to reduce the number of nodes (servers), as opposed to → scale out. Scale-in is a type of → horizontal scaling. See also → scale up, → scale down.

scale; → in.

scale out
  برون-مرپلیدن   
borun-marpelidan

Fr.:   

In computer science, to upgrade a system by increasing the number of nodes. For example, instead of going from a CPU of X and memory of Y to a CPU with 4X and 4Y memory, use 4 machines with CPU of X and memory of Y. This is a type of → horizontal scaling. See also → scale in, → scale up, → scale down.

scale; → out.

scale up
  فراز-مرپلیدن   
farâz-marpelidan

Fr.:   

In computer science, to increase the processing power of the same node/system by increasing its resources (CPU, RAM, etc.). This is a type of → vertical scaling opposite to → scale down. For example, instead of a machine with a CPU running at speed of X and having Y gigabytes of memory, use a machine with a CPU running at speed of 4X and a memory of 4Y gigabytes. See also → scale in, → scale out.

scale; → up.

scalene triangle
  سه‌بر ِ ناجور-پهلو   
sebar-e nâjur-pahlu

Fr.: triangle scalène   

A triangle no two sides of which are equal.

From L.L. scalenus, from Gk. skalenos "uneven, unequal, rough," from skallein "chop, hoe," related to skolios "crooked," from PIE base *(s)qel- "crooked, curved, bent;" → triangle.

Sebar, → triangle; nâjur-pahlu "dissimilar sides," from nâjur "dissimilar, ill-matched" + pahlu "side, flank" (Mid.Pers. pahlug "side, rib," Av. pərəsu- "rib," Ossetic fars "side, flank," cf. Skt. párśu- "rib," Lith. piršys (pl.) "horse breast").

scaler
  مرپل‌گر   
marpelgar

Fr.:   

An electronic circuit devised to give a single pulse after a prescribed number of input pulses have been received.

Agent noun from → scale.

scaling
  مرپلش   
marpeleš

Fr.:   

1) Altering original variable values (according to a specific function or an algorithm) into a range that meet particular criteria.
2) The ability of a system, or process, to handle a growing load in regards to capacity. It has two types: → vertical scaling and → horizontal scaling.

scale; → -ing.

scan
  ۱) رجروب کردن، رجروفتن ۲) رجروب   
1) rajrub kardan, rajruftan; 2) rajrub

Fr.: 1) balayer; 2) balayage   

1) (v.) To sweep a surface with a beam of light or electrons in order to reproduce or transmit a picture.
In radar, to sweep an airspace or region with a succession of directed beams from a radar aerial system.
2) (n.) An act or instance of scanning. The image or display so obtained.

M.E. scannen, from L.L. scandere "to read or mark so as to show metrical structure," originally, in classical L., "to climb" (the connecting notion is of the rising and falling rhythm of poetry), from PIE *skand- "to spring, leap" (cf. Skt. skandati "he jumps;" Gk. skandalon "a snare, trap, stumbling block;" O.Ir. scendim "I jump").

Rajrub, literally "sweeping along rows," from raj "row, line" + rub "to sweep." The first component raj, variants raž, rak, râk, rezg (Lori), ris, risé, radé, rasté, râsté, related to râst "right, true; just, upright, straight," → row, → right. The second component rub stem of rubidan, ruftan "to sweep," related to robudan "to rub, carry off;" Mid.Pers. rôb- "to rub, sweep, attract;" Av. urūpaiieinti "to cause racking pain(?);" cf. Skt. rop- "to suffer from abdominal pain," rurupas "to cause violent pain," ropaná- "causing racking pain," rópi- "racking pain;" L. rumpere "to break;" O.E. reofan "to break, tear."

scanner
  رجروبگر   
rajrubgar

Fr.: scanneur   

Any device for exposing an image on film, a sensitized plate, etc., by tracing light along a series of many closely spaced parallel lines.

Agent noun of → scan.

scanning
  رجروب   
rajrub

Fr.: balayage   

The process of analyzing or synthetizing successively the light values of the elements making up a picture area, according to a pre-determined method.

Verbal noun of → scan.

scaphe
     

Fr.: scaphe   

A → sundial consisting of an inverted half sphere and a central vertical → gnomon used by ancient Greeks. See also → Eratosthenes experiment.

Gk. skaphe "boat, skiff; a bowl."

scarp
  تنده   
tondé (#)

Fr.: escarpe   

Geology: A line of cliffs produced by faulting, erosion, or landslides. → cliff.

From It. scarpa.

Tondé "a steep slope of a mountain," from tond "swift, rapid, brisk; fierce, severe" (Mid.Pers. tund "sharp, violent;" Sogdian tund "violent;" cf. Skt. tod- "to thrust, give a push," tudáti "he thrusts;" L. tundere "to thrust, to hit" (Fr. percer, E. pierce, ultimately from L. pertusus, from p.p. of pertundere "to thrust or bore through;" PIE base *(s)teud- "to thrust, to beat"); cf. dialectal Anzali tin, Laki den, Tâleši teš "steep rock."

scatter
  ۱) پراکندن؛ ۲) پراکنش   
1) parâkandan; 2) parâkaneš

Fr.: 1) diffuse; 2) diffusion, dispersion   

1) To cause → electromagnetic waves or a → beam of → particles to be irregularly → deflected, → dispersed, or → reflected, or be turned aside in the process of → scattering.
2) The act of → scattering; something that is → scattered.

M.E. scateren, schateren "to disperse, break up, destroy;" cf. M.Du. schaderen "to scatter."

Parâkandan "to scatter, to disperse;" Mid.Pers. parakandan "to scatter" (cf. apakandan "to throw"), from Proto-Iranian *pari-kan-, from *pari, *par- "around" (cf. Pers. pirâ-, variant par- "around, about," from Mid.Pers. pêrâ; O.Pers. pariy "around, about," Av. pairi "around, over," per- "to pass over, beyond;" cf. Skt. pari; PIE base *per- "through, across, beyond;" cf. Gk. peri "around, about, beyond;" L. per "through") + *kan- "to throw, place, put" (cf. Pers. afgandan "to throw; to lay, place;" kandan "to dig; to extract;" Mid.Pers. kan-, kandan "to dig;" O.Pers. kan- "to dig," akaniya- "it was dug;" Av. kan- "to dig," uskən- "to dig out;" cf. Skt. khan- "to dig," khanati "he digs," kha- "cavity, hollow, cave, aperture").

scattered
  پراکنده   
parâkandé (#)

Fr.: diffus   

1) Occurring or distributed over widely spaced and irregular intervals in time or space.
2) The quality of a particle that has undergone → scattering.

Past participle of → scatter.

scatterer
  پراکننده   
parâkanandé

Fr.: diffuseur   

A → particle that causes → scattering of another particle through interaction with it.

scatter; → -er.

scattering
  پراکنش   
parâkaneš (#)

Fr.: diffusion   

The process in which the direction of motion of → particles or → waves is changed randomly because of their → interactions (→ collisions) with other particles of the → medium transversed.
Two parameters govern scattering: 1) the wavelength (λ) of the incident radiation, and 2) the size of the scattering particle (r), usually expressed as the nondimensional size parameter, x = 2πr / λ. The size parameter defines three types of scattering:
1) x much less than 1 (or r much smaller than λ), → Rayleigh scattering;
2) x ~ 1 (or rλ), → Mie scattering; and
3) x much larger than 1 (or r much larger than λ), → geometric scattering.
See also: → atmospheric scattering, → backscattering, → Brillouin scattering, → coherent scattering, → Compton scattering, → elastic scattering, → forward scattering, → last scattering, → last scattering surface, → multiple scattering, → noncoherent scattering, → quasi-single-scattering approximation, → Raman scattering, → scattering angle, → scattering coefficient, → scattering of stars, → selective scattering, → single scattering, → spin-flip scattering, → surface of last scattering, → Thomson scattering.
Related terms: → diffraction; → diffusion; → dispersion; → distribution.

Verbal noun of → scatter.

scattering angle
  زاویه‌ی ِ پراکنش   
zâvie-ye parâkaneš

Fr.: angle de diffusion   

The angle between the → incident radiation on a → particle (such as a water droplet in a rainbow) and the scattered radiation (such as the light ray leaving the droplet). Scattering angle is a function of → impact parameter. In other words, The angle along which the change of direction has taken place, irrespective whether radiation is scattered by particles or reflected (refracted) by a surface.

scattering; → angle.

scattering coefficient
  همگر ِ پراکنش   
hamgar-e parâkaneš

Fr.: coefficient de diffusion   

The fraction of light scattered per unit distance in a medium.

scattering; → coefficient.

scattering of stars
  پراکنش ِ ستارگان   
parâkaneš-e setâregân

Fr.: diffusion des étoiles   

The progressive increase of random motions of → disk stars with increasing stellar → ages. While some initial random motion seems likely in the disturbed conditions of disks when the oldest stars formed, the observation is generally attributed to scattering processes. Both massive gas → clumps and → spiral waves are considered as scattering agents (J. A. Sellwood & J. J. Binney, 2002, astro-ph/0203510 and references therein).

scattering; → star.

Schönberg-Chandrasekhar limit
  حدّ ِ شونبرگ-چاندراسکهار   
hadd-e Schönberg-Chandrasekhar

Fr.: limite de Schönberg-Chandrasekhar   

During the → main sequence stage, a star burns the hydrogen in its core and transforms it into helium. When the helium mass amounts to about 10% of the initial stellar mass, the star can no longer maintain the → hydrostatic equilibrium in its core; the star increases its volume and leaves the main sequence in order to become a → red giant.

Named after the Brazilian astrophysicist Mario Schönberg (1914-1990) and Subramahmanyan Chandrasekhar, → Chandrasekhar limit, who were the first to point out this limit and derive it (1942, ApJ 96, 161).

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