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potassium nitrate

(Encyclopedia)potassium nitrate, chemical compound, KNO3, occurring as colorless, prismatic crystals or as a white powder; it is found pure in nature as the mineral saltpeter, or niter. (The name saltpeter is also ...

solder

(Encyclopedia)solder sŏdˈər [key], metal alloy used in the molten state as a metallic binder. The type of solder to be used is determined by the metals to be united. Soft solders are commonly composed of lead an...

silver nitrate

(Encyclopedia)silver nitrate nīˈtrāt [key], chemical compound, AgNO3, a colorless crystalline material that is very soluble in water. The most important compound of silver, it is used in the preparation of silve...

Stein, William Howard

(Encyclopedia)Stein, William Howard, 1911–80, American biochemist, b. New York City, Ph.D. Columbia, 1937. Stein was a professor at the Rockefeller Institute for Medical Research (now Rockefeller Univ.) from 1937...

micromechanics

(Encyclopedia)micromechanics, the combination of minuscule electrical and mechanical components in a single device less than 1 mm across, such as a valve or a motor. Although micromechanical production processes an...

giraffe

(Encyclopedia)giraffe, African ruminant mammal, genus Giraffa, living in open savanna S of the Sahara. Giraffes have historically been considered to be one species, G. camelopardalis, with a number of subspecies, b...

interferon

(Encyclopedia)interferon ĭnˌtərfērˈŏn [key], any of a group of proteins produced by cells in the body in response to an attack by a virus. A cell infected by a virus releases minute amounts of interferons, wh...

Darwin's finches

(Encyclopedia)Darwin's finches or Galapagos finches gəläˈpəgōsˌ [key], species of small perching birds, constituting the subfamily Geospizinae of the tanager family. Not related to the true finches, this grou...

pharming

(Encyclopedia)pharming färˈmĭng [key], the use of genetically altered livestock, such as cows, goats, pigs, and chickens, to produce medically useful products. In pharming, researchers first create hybrid genes ...

nitrogen

(Encyclopedia)nitrogen nīˈtrəjən [key], gaseous chemical element; symbol N; at. no. 7; interval in which at. wt. ranges 14.00643–14.00728; m.p. −209.86℃; b.p. −195.8℃; density 1.25 grams per liter at ...