To give blood you must: 1  Be in general good health.  Be at least 17 years old. (If you are 16 you can donate with a CBC consent form signed by your parent). There is no upper age limit as long as you have no health restrictions.
Specific radiative intensity. Specific (radiative) intensity is a quantity used in physics that describes electromagnetic radiation. It is a term used in much of the older scientific literature. The present-day SI term is spectral radiance, which can be expressed in base SI units as W mâ2 srâ1 Hzâ1.
In physics, intensity is the power transferred per unit area, where the area is an imagined surface that is perpendicular to the direction of propagation of the energy. In the SI system, it has units watts per square metre (W/m 2).