A synchrotron light monitor is an essential tool for operating a storage ring. For SPEAR3, the upgrade of the SPEAR storage ring, the light monitor was designed not only for monitoring the beam presence but also to measure beam parameters. To minimize diffraction effects, UV light around 200 nm is used to image the electron source rather than visible light. At 200 nm, the rms diffraction spot i...

Rabbit skin treated for a few minutes with ultra-violet light and then inoculated at once with vaccine virus is less susceptible to the action of the virus than is untreated skin. If 24, 48, or 72 hours elapse between the time of irradiation and inoculation, the treated skin appears to be more susceptible than is untreated skin. Skin repeatedly exposed to ultra-violet light is less susceptible ...

Typhoid bacilli are about one two-hundredth as sensitive to ultraviolet light of wave-lengths 2100 to 2800 Angström units as is the photographic plate. This sensitivity then falls off, decreasing rapidly to almost zero sensitivity at about 2970, the beginning of the sun's spectrum.