Semen is produced and originates from the seminal vesicle, which is located in the pelvis. The process that results in the discharge of semen is called ejaculation. Semen is also a form of genetic material. In animals, semen has been collected for cryoconservation. Cryoconservation of animal genetic resources is a practice that calls for the collection of genetic material in efforts for conservation of a particular breed.
Luminance is a derived measure, expressed in Candela per square metre (\( cd / m^2 \)). An alias for the unit \( cd / m^2 \) (unofficial, but still commonly used) is Nit. Luminance and illumination (Lux) are related, in the sense that luminance is typically used for light-emitting surfaces and illumination for surfaces that are being lit.
If a light source emits one candela of luminous intensity uniformly across a solid angle of one steradian, the total luminous flux emitted into that angle is one lumen (1 cdÂ·1 sr = 1 lm). Alternatively, an isotropic one-candela light-source emits a total luminous flux of exactly 4Ï lumens.