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chemical industry

(Encyclopedia)chemical industry, the business of using chemical reactions to turn raw materials, such as coal, oil, and salt, into a variety of products. During the 19th and 20th cent. technological advances in the...

Khyber Pakhtunkhwa

(Encyclopedia)Khyber Pakhtunkhwa, formerly North-West Frontier Province, province and historic region (2017 provisional pop. 35,525,047), c.51,510 sq mi (133,410 sq km), NW Pakistan, bounded on the N and W by Afgha...

pyramid, structure

(Encyclopedia)pyramid. The true pyramid exists only in Egypt and Sudan, though the term has also been applied to similar structures in other countries. Egyptian pyramids are square in plan and their triangular side...

Gujarat

(Encyclopedia)Gujarat go͝ojərätˈ [key], state (2001 provisional pop. 50,596,992), c.75,686 sq mi (196,077 sq km), W India, on the Arabian Sea. It is comprised of almost all of the Kathiawar peninsula, the desol...

Jurassic period

(Encyclopedia)Jurassic period jərăsˈĭk [key] [from the Jura Mts.], second period of the Mesozoic era of geologic time, lasting from 213 to 144 million years ago. At the start of the Jurassic most of the contine...

metamorphism

(Encyclopedia)metamorphism, in geology, process of change in the structure, texture, or composition of rocks caused by agents of heat, deforming pressure, shearing stress, hot, chemically active fluids, or a combin...

lithography

(Encyclopedia)lithography lĭthŏgˈrəfē [key], type of planographic or surface printing. It is distinguished from letterpress (relief) printing and from intaglio printing (in which the design is cut or etched in...

Precambrian

(Encyclopedia)Precambrian, name of a major division of geologic time (see Geologic Timescale, tablegeologic timescale, table), from c.5 billion to 570 million years ago. It is now usually divided into the Archean a...

Pyrenees

(Encyclopedia)Pyrenees pĭrˈənēz [key], Span. Pirineos, Fr. Pyrénées, mountain chain of SW Europe, 21,380 sq mi (55,374 sq km), between France and Spain, a formidable barrier between the Iberian Peninsula and ...

Alps

(Encyclopedia)Alps, great mountain system of S central Europe, c.500 mi (800 km) long and c.100 mi (160 km) wide, curving in a great arc from the Riviera coast on the Mediterranean Sea, along the borders of N Italy...