An Etymological Dictionary of Astronomy and Astrophysics
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فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory

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Number of Results: 8 Search : effective
effective
  ا ُسکرمند   
oskarmand

Fr.: effectif   

Actually in operation or in force; concrete; real.

M.E., from L. effectivus "practical," from effect(us), p.p. of efficere, → effect + -ivus "-ive."

Oskarmand, from oskar, → effect + -mand possession suffix.

effective aperture
  دهانه‌ی ِ ا ُسکرمند   
dahâne-ye oskarmand

Fr.: ouverture effective   

Of an antenna, the ratio of the extracted power by the antenna to the power per unit area (power density) in the incident wave.

effective; → aperture.

effective Eddington parameter
  پارامون ِ ادینگتون ِ اسکرمند   
pârâmun-e Eddington-e oskarmand

Fr.: paramètre d'Eddington effectif   

The effective value of the → Eddington parameter in a non-homogeneous system (porous opacity).

effective; → Eddington limit; → parameter.

effective focal length
  درازا‌ی ِ کانونی ِ ا ُسکرمند   
derâzâ-ye kânuni-ye oskarmand

Fr.: longueur focale effective   

The focal length of an imaging system, which consists of several lenses or mirrors.

effective; → focal length.

effective gravity
  گرانی ِ اُسکرمند   
gerâni-ye oskarmand

Fr.: gravité effective   

In a → rotating star, the sum of the → gravity and the → centrifugal acceleration. The effective gravity is a function of the rotation velocity (Ω) and the → colatitude (θ). At the pole (θ = 0°) and the equator (θ = 90°) the effective gravity is radial. See also → total gravity.

effective; → gravity.

effective radius
  شعاع ِ ا ُسکرمند   
šo'â'-e oskarmand

Fr.: rayon effectif   

Of a galaxy, the distance from its center within which half of the total luminosity is included.

effective; → radius.

effective temperature
  دمای ِ ا ُسکرمند   
damâ-ye oskarmand

Fr.: température effective   

A measure of the surface temperature of a star derived from the total emitted energy, assuming that the star is a → blackbody emitter (→ Stefan-Boltzmann law, → Planck's radiation law). See also → brightness temperature; → color temperature.

effective; → temperature.

effectiveness
  اسکرمندی   
oskarmandi

Fr.: effectivité   

The degree to which goals are achieved and the extent to which posed problems are solved. Compare → efficiency.

effective; → -ness.