Fr.: éclairement énergétique
A unit of angular measure; one radian is that angle with an intercepted arc on a circle equal in length to the radius of the circle.
From radi(us) + -an an originally adj. suffix.
1) Generally, the → radiant energy
per unit → solid angle per unit of
→ projected area of the → source.
It is usually expressed in → watt per
→ steradian per → square
→ meter (W m-2 sr-1). Same as
Tâbešmandi, noun from tâbešmand "possessing radiation," from tâbeš, → radiation, + -mand a suffix denoting possession; Mid.Pers. -ômand suffix forming adjectives of quality.
1) tâbandé, tâbeši; 2) tâbsar
1) Sending out rays of light; bright; shining.
M.E., from M.Fr. radiant, from L. radiantem (nominative radians) "shining," pr.p. of radiare "to shine, radiate," → radiation.
Fr.: dérive de radiant
Fr.: énergie radiative
šâr-e tâbeši (#)
Fr.: flux radiatif
Rate of flow of energy as → radiation.
Fr.: intensité de rayonnement
A measure of the amount of radiation emitted from a point expressed as the radiant flux per unit solid angle leaving this source.
Fr.: irradiation solaire
The radiative power per unit area in all wavelengths from the Sun received by the Earth at its average distance from the Sun. Its mean value is called the → solar constant. The solar irradiance changes over a year by about 6.6% due to the variation in the Earth/Sun distance. Moreover, solar activity variations cause irradiance changes of up to 1%.
The solid angle subtended at the center of a sphere by an area on its surface numerically equal to the square of the radius. → square degree.