material removal
71native American — native American, adj. a person born in the United States. [1835 45, Amer.] * * * ▪ indigenous peoples of Canada and United States Introduction also called American Indian, Amerindian, Amerind, Indian, Aboriginal American, or First Nation… …
72Native American — Indian (def. 1). Usage. See Indian, Eskimo. * * * ▪ indigenous peoples of Canada and United States Introduction also called American Indian, Amerindian, Amerind, Indian, Aboriginal A …
73United States — a republic in the N Western Hemisphere comprising 48 conterminous states, the District of Columbia, and Alaska in North America, and Hawaii in the N Pacific. 267,954,767; conterminous United States, 3,022,387 sq. mi. (7,827,982 sq. km); with… …
74art conservation and restoration — Maintenance and preservation of works of art, their protection from future damage, deterioration, or neglect, and the repair or renovation of works that have deteriorated or been damaged. Research in art history has relied heavily on 20th and… …
75Asbestos — For other uses, see Asbestos (disambiguation). Fibrous asbestos on muscovite …
76Erosion — is the carrying away or displacement of solids (sediment, soil, rock and other particles) usually by the agents of currents such as, wind, water, or ice by downward or down slope movement in response to gravity or by living organisms (in the case …
77Drill bit — For the fictional character, see Drill Bit (Transformers). For the cancelled skyscraper nicknamed Drill bit, see Chicago Spire. For the types used in drilling wells, see Well drilling. From top to bottom: Spade, lip and spur (brad point), masonry …
78Dental amalgam controversy — Dental amalgam filling The dental amalgam controversy refers to the conflicting views over the use of amalgam as a filling material mainly because it contains the element mercury. The concern centers on the health effects of toxicity or allergy… …
79mining — /muy ning/, n. 1. the act, process, or industry of extracting ores, coal, etc., from mines. 2. the laying of explosive mines. [1250 1300; ME: undermining (walls in an attack); see MINE2, ING1] * * * I Excavation of materials from the Earth s… …
80separation and purification — ▪ chemistry Introduction in chemistry, separation of a substance into its components and the removal of impurities. There are a large number of important applications in fields such as medicine and manufacturing. General principles… …
