An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 22 Search : fine
adaptive mesh refinement (AMR)
  نازکش ِ نیاوشی ِ بانچه   
nâzokeš-e niyâveši-ye bâncé

Fr.: raffinement de maillage adaptatif   

A type of → algorithm that dynamically achieves high → resolution in localized regions of multidimensional → numerical simulations. AMR provides a higher → accuracy solution at lower costs, through an automatically → optimal distribution of → grid points for the computation region. It relies on locally refined mesh or mesh patches to increase the resolution of an underlying coarse mesh only where needed. It can alleviate some of the complexities of the generation of high quality grid and reduce the number of → iterations of "trial-and-error" between the grid generation and solution required for tailoring the grid to the specification of a problem. Thus, it can offer orders of magnitude saving in computational and storage costs over an equivalent uniformly refined mesh. AMR was originally developed for → inviscid, → compressible flow (Berger et al., 1984, Adaptive Mesh Refinement for Hyperbolic Partial Differential Equations. J. Comp. Phy., 53, 484). It has been extended to solve → Navier-Stokes equations, time dependent problems and more. Several AMR techniques have been developed and applied to compressible flow fields to capture characteristics at the strong gradient or discontinuous regions requiring higher space resolution, such as regions involving → shock waves, vortices (→ vortex), and → wakes (see, e.g., Qingluan Xue, "Development of Adaptive Mesh Refinement Scheme and Conjugate Heat Transfer Model for Engine Simulations" (2009), Iowa State Univ., Graduate Theses and Dissertations, Paper 10678).
See also → Smoothed Particle Hydrodynamics.

adaptive; → mesh; → refinement.


Fr.: affine   

Math.: Of or pertaining to the geometry of → affine transformations. See also: → affine combination, → affine geometry, → affine set, → affinity.

From Fr., from L. affinis "bordering on; neighboring; related."

Karvan, literally "bordering on; possessing border (with); related," from (Bašgard) ker "border, boundary," (Fin Bandar Abbas) karaq "border, edge;" classical Pers. karân, kenâr "boundary, side, edge;" + -van suffix of possession, relation.

affine combination
  میازش ِ کروَن   
miyâzeš-e karvan

Fr.: combinaison affine   

A linear combination of vectors in which all the vector coefficients add up to one.

affine; → combination.

affine geometry
  هندسه‌ی ِ کروَن   
hendese-ye karvan

Fr.: géométrie affine   

The study of the properties which are → invariant under → affine transformations.

affine; → geometry.

affine set
  هنگرد ِ کروَن   
hangard-e karvan

Fr.: ensemble affine   

A set → if and only if (iff) for any two points in the → set, the line through them is contained in the set. In other words, for any two points in the set, their → affine combinations are in the set itself.

affine; → set.

affine transformation
  ترادیس ِ کروَن   
tarâdis-e karvan

Fr.: transformation affine   

Any → transformation preserving → collinearity.

affine; → transformation.

  پربستن، پربست کردن   
parbastan (#), parbast kardan (#)

Fr.: confiner   

To enclose within bounds; to restrict.

M.E., from M.Fr. confins, confines, from L. confinis "boundary, border," from con-, → com- "with" + finis "end."

Parbastan, parbast kardan, literally "close around," from par- "around," → circum-, + bast, bastan "to close," → closed.

confined plasma
  پلاسمای ِ پربسته   
pelâsmâ-ye parbasté

Fr.: plasma confiné   

Plasma in which magnetic field lines forming closed surfaces confine the plasma.

Confined, p;p. of → confine; → plasma.

parbast (#)

Fr.: confinement   

General: The act of confining; the state of being confined. Physics: A property of quantum electrodynamics whereby quarks cannot exist as free particles, but are forever bound into protons, neutrons, etc.

Noun from → confine.


Fr.: définir   

1) To state or set forth the meaning of (a word, concept, etc.).
2) To explain or identify the nature or essential qualities of.
3) To fix or mark the boundaries or extent of.

From O.Fr. définir "to end, determine," from L. definire "to limit, determine, explain," from → de- + finire "to bound, limit," from finis "boundary."

Hedâridan, infinitive from Semnâni hedâr "boundary (between pieces of lands)," Tabari hedâri "boundary, border," may be related to Av. haêtav- "dam, dike," Skt. setu- "a ridge of earth, bank, dike, dam, bridge."


Fr.: défini   

1) Clearly characterized or fixed.
2) Showing clearly the outline or profile or boundary.
3) Computer science: A variable having received a value prior to a given point in a program.

P.p. of → define.

nâzok (#)

Fr.: fine   

Very thin or slender. → fine structure, → fine-structure constant.

M.E. fin, from O.Fr. fin "perfected, of highest quality," from L. finis "end, limit."

Nâzok "thin, slender, subtle," from Mid.Pers. nâzuk "tender, gentle," variant nâzik, from nâz "joy, pride, glory" + → -ik.

fine dust
  ریزگرد، غبار ِ نازک   
rizgard, qobâr-e nâzok

Fr.: poussière fine   

Meteorology: An → inhomogeneous  → mixture of tiny, part → solid, part → liquid or → gaseous  → particles that are, in average, smaller than ten → microns. The constituents are soot, heavy metals, organic substances, and dioxins. The smaller these dust particles, the deeper they penetrate into the lung. Larger particles are intercepted by mucous membrane in nose, mouth, and throat but smaller particles can penetrate the smallest lung bronchioles and may cause severe damage (various respiratory disorders, lung cancer) → particulate matter.

fine; → dust.

fine structure
  ساختار ِ نازک   
sâxtâr-e nâzok

Fr.: structure fine   

Closely spaced components seen at high resolution in a → spectral line. The phenomenon is explained by the fact that instead of a single → energy level corresponding to a given value of the → quantum number  n, there are actually a number of energy levels lying close to one another. → fine-structure constant, → fine-structure line.

fine; → structure.

fine-structure constant
  پایای ِ ساختار ِ نازک   
pâyâ-ye sâxtâr-e nâzok

Fr.: constante de la structure fine   

A measure of the strength of → interaction between a → charged particle and the → electromagnetic field. It is a → dimensionless number expressed (in → cgs units) by α = e2c, where e is the → electron charge, ħ is the → reduced Planck's constant, and c is the → speed of light. It is approximately equal to 1/137 or 7.3 × 10-3. The smallness of this number is of great importance since it determines the size of → atoms and the → stability of → matter. Same as → electromagnetic coupling constant.

fine structure; → constant.

fine-structure line
  خط با ساختار ِ نازک   
xatt bâ sâxtâr-e nâzok

Fr.: raie de structure fine   

A → spectral line whose → energy levels have a → fine structure. Examples are [C II] 157.7 μm (→ singly ionized carbon), [O III] 88 μm, and [Ne II] 12.8 μm.

fine; → structure; → line.


Fr.: hyperfine   

Extremely fine or thin, especially of a → spectral line split into two or more very thin components. → hyperfine structure; → hyperfine transition.

hyper-, → fine structure.

hyperfine structure
  ساختار ِ اَبَرنازک   
sâxtâr-e abar-nâzok (#)

Fr.: structure hyperfine   

In spectroscopy, the → splitting of a spectral line into a number of very thin components. It results from a small perturbation in the energy levels of atoms or molecules due to the magnetic dipole-dipole interaction arising from the interaction of the nuclear → magnetic moment with the → spin of the electron. It can be observed only at high spectral dispersion. → fine structure.

hyperfine; → structure.

hyperfine transition
  گذرش ِ اَبَرنازک   
gozareš-e abar-nâzok

Fr.: transition hyperfine   

An → atomic transition involving a → hyperfine structure.

hyperfine; → transition.

quark confinement
  پربست ِ کو‌آرک‌ها   
parbast-e kuârkhâ

Fr.: confinement des quarks   

The phenomenon wherein the → quarks are permanently bound together and can never be removed from the → hadrons they compose.

quark; → confinement.

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