El Ninyo (#)
Fr.: El Niño
El Niño. A significant warming of the ocean surface over the eastern and central equatorial Pacific that occurs at irregular intervals, generally ranging between two and seven years. El Niño conditions, which are often characterized by "warm events," most often develop after late December during the early months of the year and decay during the following year. → La Nina.
From Sp. El Niño "the child," i.e. "the Christ Child," alluding to the appearance of the current near Christmas. The term was originally applied by fishermen of northern Peru.
Elara (Jupiter VII)
The thirteenth known moon of Jupiter, discovered in 1905 by Charles Perrine.
In Gk. mythology, Elara was the mother by Zeus of the giant Tityus.
From Fr., from Gk. elastos "ductile, flexible," related to elaunein "to strike, beat out."
Kešâyand, from keš stem of kešidan/kašidan "to pull, drag, draw" (Av. karš- "to draw, to plough," karša- "furrow;" cf. Skt. kars-, kársati "to pull, drag, plough," Gk. pelo, pelomai "to be busy, to bustle") + âyand agent form of âmadan "to come; to become," from Mid.Pers. âmatan (O.Pers. gam- "to come; to go," Av. gam- "to come; to go," jamaiti "goes;" O.Iranian *āgmatani; Skt. gamati "goes;" Gk. bainein "to go, walk, step;" L. venire "to come;" Tocharian A käm- "to come;" O.H.G. queman "to come;" E. come; PIE root *gwem- "to go, come").
Fr.: collision élastique
A collision between two particles which conserves the total kinetic energy and momentum of the system.
Fr.: déformation élastique
Fr.: limite d'élasticité, ~ élastique
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.
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.
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.
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.
Fr.: arc électrique
bâr-e barqi (#)
Fr.: charge électrique
Fr.: circuit électrique
jarayân-e barq (#)
Fr.: courant électrique
dipol-e barqi, diqotbe-ye ~
Fr.: dipôle électrique
1) A type of → charge distribution
consisting of two charges, a
positive and a negative charge of the same magnitude separated by a
distance s, which is small compared to the distance r to
the point P at which the → electric potential
is V and the → electric field
intensity is E.The potential falls as the
square of the distance (1/r2) and the electric
field intensity decreases as
the cube of the distance (1/r3).
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.
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.
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.
Fr.: multipôle électrique
An electric → charge distribution consisting of more than four → positive and → negative → electric charges located at a small distance from each other. The multipole concept is an extension of the → electric quadrupole. For the generalized multipole characterized by the letter l, the potential at a distance r varies as 1/rl + 1 and the field intensity as 1/rl + 2.
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.