The U.S. Army Corps of Engineers is organized geographically into eight permanent divisions, one provisional division, one provisional district, and one research command reporting directly to the HQ. Within each division, there are several districts.
Laser Safety Glasses - Holmium Laser. 1  On this page you will find our range of Holmium laser safety glasses , Ruby laser safety glasses, Dye and Erbium Laser Safety Glasses. 2  Important: Australian laser safety standards AS/NZS 2211.3:2002 require L-Ratings to be clearly marked on the laser glasses.
It is also used in nuclear reactors for nuclear control rods. Holmium oxide is used as yellow gas colouring. Holmium in the environment. Holmium is one of the rarer of the rare-earth elements but is, nevertheless, 20 times more abundant than silver.