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holmium

(Encyclopedia)holmium hōlˈmēəm [key] [Lat.,=Stockholm], metallic chemical element; symbol Ho; at. no. 67; at. wt. 164.93032; m.p. about 1,474℃; b.p. about 2,425℃; sp. gr. 8.78 at 25℃; valence +3. Holmium ...

Holocaust Memorial Museum, United States

(Encyclopedia)Holocaust Memorial Museum, United States, in Washington, D.C. on the National Mall, memorial to the victims of the Holocaust. Designed by architect James Ingo Freed, it opened in 1993. Using a stark, ...

sodium hydroxide

(Encyclopedia)sodium hydroxide, chemical compound, NaOH, a white crystalline substance that readily absorbs carbon dioxide and moisture from the air. It is very soluble in water, alcohol, and glycerin. It is a caus...

speedometer

(Encyclopedia)speedometer, instrument that indicates speed. A cable from an automotive speedometer is attached to the rear of the transmission of an automobile; the cable turns at a rate proportional to the speed o...

radio-frequency identification

(Encyclopedia)radio-frequency identification (RFID), a technology that uses radio waves to transmit data and uniquely identify an animal, person, or thing. An RFID system typically consists of a tag and a reader. T...

steel

(Encyclopedia)steel, alloy of iron, carbon, and small proportions of other elements. Iron contains impurities in the form of silicon, phosphorus, sulfur, and manganese; steelmaking involves the removal of these imp...

water, desalination of

(Encyclopedia)water, desalination of, process of removing soluble salts from water to render it suitable for drinking, irrigation, or industrial uses. The principal methods used for desalination include distillatio...

cellular telephone

(Encyclopedia)cellular telephone or cellular radio, telecommunications system in which a portable or mobile radio transmitter and receiver, or “cellphone,” is linked via microwave radio frequencies to base tran...

martial arts

(Encyclopedia)martial arts, various forms of self-defense, usually weaponless, based on techniques developed in ancient China, India, and Tibet. In modern times they have come into wide use for self-protection, as ...

sandstone

(Encyclopedia)sandstone, sedimentary rock formed by the cementing together of grains of sand. The usual cementing material in sandstone is calcium carbonate, iron oxides, or silica, and the hardness of sandstone va...