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 radiometry, radiant intensity is the radiant flux emitted, reflected, transmitted or received, per unit solid angle, and spectral intensity is the radiant intensity per unit frequency or wavelength, depending on whether the spectrum is taken as a function of frequency or of wavelength. These are directional quantities.