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.
Rare earth metal that proved to be a mixture of the elements holmium and samarium. Rf: Rutherfordium: 106 Proposed name for seaborgium. The symbol and name were instead used for element 104. Sa: Samarium: 62 Current symbol is Sm. So: Sodium: 11 Current symbol is Na. Sp: Spectrium: 70 Suggested name for ytterbium. St: Antimony: 51 Current symbol is Sb. Tn