An Etymological Dictionary of Astronomy and Astrophysics

فرهنگ ریشه شناختی اخترشناسی-اخترفیزیک

M. Heydari-Malayeri    -    Paris Observatory



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Number of Results: 647
elastic collision
  همکوبش ِ کشایند   
hamkubš-e kešâyand

Fr.: collision élastique   

A collision between two particles which conserves the total kinetic energy and momentum of the system.

elastic; → collision.

elastic deformation
  وادیسش ِ کشایند   
vâdiseš-e kešâyand

Fr.: déformation élastique   

A deformation of a → solid body in which the change (→ strain) in the relative position of points in the body disappears when the deforming stress is removed. See also → elastic limit.

elastic; → deformation.

elastic limit
  حد ِ کشایند   
hadd-e kešâyand

Fr.: limite d'élasticité, ~ élastique   

The smallest → stress beyond which a → solid body can no longer return to its original shape. The material ceases to obey → Hooke's law. Also called → yield point.

elastic; → limit.

elastic scattering
  پراکنش ِ کشایند   
parâkaneš-e kešâyand

Fr.: diffusion élastique   

In a → collision between two → particles, the reaction in which the total → kinetic energy of the system, projectile plus target, is the same before the collision as after.
In the interaction of → electromagnetic waves with particles, the scattering when the → wavelength (→ frequency) of the → scattered light is the same as the → incident light (→ Rayleigh scattering, → Mie scattering).

elastic; → scattering.

elastic wave
  موج ِ کشایند   
mowj-e kešâyand (#)

Fr.: onde élatique   

A wave that propagates by → elastic deformation of the medium. The → propagation takes place by a change in shape that disappears when the forces are removed. In other words, the displaced particles transfer momentum to adjoining particles, and are themselves restored to their original position. A → seismic wave is a type of elastic wave.

elastic; → wave.

kešâyandi (#)

Fr.: élasticité   

The ability of a body which has been → deformed by an applied → force to return to its original shape when the force is removed. Up to a certain point the material obeys → Hooke's law. See also → ductility, → plasticity.

elastic + → -ity.

barqi (#)

Fr.: électrique   

Pertaining to, derived from, produced by, or associated with electricity.

Term coined in by the English physicist William Gilbert (1540-1603) in treatise De Magnete (1600), from L. electrum "amber," from Gk. elektron "amber."

Barqi, adj. of barq, → electricity.

electric arc
  کمان ِ برقی   
kamân-e barqi

Fr.: arc électrique   

A luminous and extremely hot electrical → discharge between two → electrodes when an ionized → plasma is created in the air or gas across the electrodes.

electric; → arc.

electric charge
  بار ِ برقی   
bâr-e barqi (#)

Fr.: charge électrique   

The intrinsic property of matter responsible for all electric phenomena, occurring in two forms arbitrarily designated → negative and → positive.

electric; → charge.

electric circuit
barqrâh (#)

Fr.: circuit électrique   

Physics: A closed path followed by an → electric current; a number of → conductors interconnected for the purpose of carrying an electric current.

electric; → circuit.

electric current
  جریان ِ برق   
jarayân-e barq (#)

Fr.: courant électrique   

The → rate at which → electric charge → flows past a given point through a → conductor, measured in → amperes.

electric; → current.

electric dipole
  دوقطبه‌ی ِ برقی   
doqotbe-ye barqi

Fr.: dipole électrique   

1) Two equal and opposite charges separated by a very small distance.
2) A simple antenna consisting of a pair of oppositely charged conductors capable of radiating an electromagnetic wave in response to the movement of an electric charge from one conductor to the other.

electric; → dipole.

electric discharge
  وابار ِ برقی   
vâbâr-e barqi

Fr.: décharge électrique   

The flow of electricity through a gas, resulting in the emission of radiation that is characteristic of the gas and of the intensity of the current.

electric; → discharge.

electric field
  میدان ِ برقی   
meydân-e barqi (#)

Fr.: champ électrique   

The effect produced by the existence of an → electric charge in the volume of space that surrounds it. The direction of the field is taken to be the direction of the force it would exert on a positive test charge. The electric field is radially outward from a positive charge and radially in toward a negative point charge.

electric; → field.

electric intensity
  درتنویی ِ برقی   
dartanuyi-e barqi (#)

Fr.: intensité électrique   

The strength of an electric field at any point as measured by the force exerted upon a unit positive charge placed at that point.

electric; → intensity.

electric potential
  توند ِ برقی   
tavand-e barqi

Fr.: potentiel électrique   

The amount of → work required to move a unit → electric charge from → infinity to a specific point against an → electric field. The → SI unit of electric potential is → joules per → coulomb, otherwise known as → volt.

electric; → potential.

electric scalar potential
  توند ِ مرپلی ِ برقی   
tavand-e marpeli-ye barqi

Fr.: potentiel électrique scalaire   

A potential φ defined so that the → electric field  E is expressed by a combination of its → gradient and the variation of the → magnetic vector potential over time: E = -∇φ -∂A/∂t.

electric; → scalar; → potential.

barqi (#)

Fr.: électrique   

Of, relating to, or concerned with electricity; electric.

electric + → -al.

electrical conductivity
  هازندگی ِ برقی   
hâznadegi-e barqi

Fr.: conductivité électrique   

A measure of a material's ability to conduct an electrical current. It is the reciprocal of the → resistivity. Conductivity is expressed by σ = ne2l/(2mv), where n is the number of electrons per cm3 volume of the → conductor, e is the → electron charge, l is the → mean free path, m is the → electron mass, and v is the arithmetic mean velocity of thermal motion of electrons at a given temperature.

electrical; → conductivity.

electrical network
  توربست ِ برقی   
turbast-e barqi

Fr.: réseau électrique   

An arrangement of the various electrical energy sources with interconnected electrical devices.

electric; → network.

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