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perfluoroalkyl and polyfluoroalkyl substances

(Encyclopedia)perfluoroalkyl and polyfluoroalkyl substances (PFAS), a group of several thousand synthetic organic chemical compounds made up of a chain of carbon atoms bonded to fluorine atoms. PFAS, which resist w...

sapphire

(Encyclopedia)sapphire, precious stone. A transparent blue corundum, it is classified among the most valuable of gems. Sapphires are found chiefly in Madagascar, Sri Lanka, and Myanmar and also in Thailand, Tanzani...

umbrella

(Encyclopedia)umbrella, a small canopy used as a protection against the sun in China, Egypt, and elsewhere in remote antiquity. It was often an emblem of rank. During the Middle Ages the umbrella became almost exti...

tamoxifen

(Encyclopedia)tamoxifen təmŏkˈsĭfĕnˌ [key], synthetic hormone used in the treatment of breast cancer. Introduced in 1978, tamoxifen is used to prevent recurrences of cancer in women who have already undergone...

tagua

(Encyclopedia)tagua täˈgwä [key], fruit of the ivory, or ivory-nut, palms (Phytelephas species), which flourish in tropical America from Paraguay to Panama. The female palms bear large woody, burrlike fruits, ea...

Bergius, Friedrich Karl Rudolf

(Encyclopedia)Bergius, Friedrich Karl Rudolf, 1884–1949, German chemist, Ph.D. Univ. of Leipzig, 1907. In 1910, Bergius set up a laboratory to carry out his research and in 1914 transferred the operation to the E...

bark cloth

(Encyclopedia)bark cloth, primitive fabric made in tropical and subtropical countries from the soft inner bark of certain trees. It has been made and used in parts of Africa and India, the Malay Peninsula, Samoa, t...

Jhelum, town, Pakistan

(Encyclopedia)Jhelum jāˈlo͝om [key], town (1981 pop. 92,646), NE Pakistan, on the Jhelum River. Located on the main railroad and road on Punjab piedmont plain, it is an important market for timber, and has sawmi...

Kearny

(Encyclopedia)Kearny kärˈnē [key], town (1990 pop. 34,874), Hudson co., NE N.J.; inc. 1899. The town was formerly the site of textile mills that dated to the late 1800s and shipyards and dry docks that were of g...

Matanzas, city, Cuba

(Encyclopedia)Matanzas, city (1994 est. pop. 115,000), capital of Matanzas prov., W central Cuba. A port with a large, deep harbor, it exports sugar, fruits, and sisal. Industries in the city include sugar refineri...