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ultrasonics

(Encyclopedia)ultrasonics, study and application of the energy of sound waves vibrating at frequencies greater than 20,000 cycles per second, i.e., beyond the range of human hearing. The application of sound energy...

urinalysis

(Encyclopedia)urinalysis yo͝orˌənălˈĭsĭs [key], clinical examination of urine for the purpose of medical diagnosis. Urine is initially examined for such characteristics as color, odor, and specific gravity. ...

ink

(Encyclopedia)ink, pigmented fluid used for writing and drawing, or a viscous compound used for printing, both of various colors but most frequently black. The oldest known variety, India ink or China ink, is still...

Buthelezi, Mangosuthu Gatsha

(Encyclopedia)Buthelezi, Mangosuthu Gatsha (Ashpenaz Nathan Mangosuthu Gatsha Buthelezi) äshˈpĕnäzˌ, mängˌgōso͞oˈto͞o gätˈshä bo͞otəlāˈzē [key], 1928–, South African political leader. A Zulu ch...

Western European Union

(Encyclopedia)Western European Union (WEU), European security and defense organization. It was set up in Brussels in 1955 as a defensive, economic, social, and cultural organization, consisting of Belgium, France, ...

clay

(Encyclopedia)clay, common name for a number of fine-grained, earthy materials that become plastic when wet. Chemically, clays are hydrous aluminum silicates, ordinarily containing impurities, e.g., potassium, sodi...

potassium

(Encyclopedia)potassium pətăsˈēəm [key], a metallic chemical element; symbol K [Lat. kalium=alkali]; at. no. 19; at. wt. 39.0983; m.p. 63.25℃; b.p. 760℃; sp. gr. .862 at 20℃; valence +1. Potassium is a s...

Gram's stain

(Encyclopedia)Gram's stain, laboratory staining technique that distinguishes between two groups of bacteria by the identification of differences in the structure of their cell walls. The Gram stain, named after its...

hydrogen chloride

(Encyclopedia)hydrogen chloride, chemical compound, HCl, a colorless, poisonous gas with an unpleasant, acrid odor. It is very soluble in water and readily soluble in alcohol and ether. It fumes in moist air. It is...

hydrolysis

(Encyclopedia)hydrolysis hīdrŏlˈĭsĭs [key], chemical reaction of a compound with water, usually resulting in the formation of one or more new compounds. The most common hydrolysis occurs when a salt of a weak ...