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marine engine

(Encyclopedia)marine engine, machine for the propulsion of watercraft. The earliest marine power plants, reciprocating steam engines, were used almost exclusively until the early 1900s. In later ship construction t...

Tymoshenko, Yulia Volodymyrivna

(Encyclopedia)Tymoshenko, Yulia Volodymyrivna, 1960–, Ukrainian political leader, prime minister of Ukraine (2005, 2007–10), b. Dnipro (Dnipropetrovsk). She studied economics and cybernetics at Dnipropetrovsk S...

galaxy

(Encyclopedia)CE5 Hubble classification of galaxies: Elliptical galaxies (E) are classified according to the degree of flattening of the ellipse. Spiral galaxies (S) and barred spiral galaxies (SB) are classifie...

sulfuric acid

(Encyclopedia)sulfuric acid, chemical compound, H2SO4, colorless, odorless, extremely corrosive, oily liquid. It is sometimes called oil of vitriol. Although sulfuric acid is now one of the most widely used c...

thermodynamics

(Encyclopedia)thermodynamics, branch of science concerned with the nature of heat and its conversion to mechanical, electric, and chemical energy. Historically, it grew out of efforts to construct more efficient he...

periodic table

(Encyclopedia)CE5 periodic table, chart of the elements arranged according to the periodic law discovered by Dmitri I. Mendeleev and revised by Henry G. J. Moseley. In the periodic table the elements are arrange...

Allegheny

(Encyclopedia)Allegheny ălˈəgāˌnē, ălˈəgäˌnē [key], river, 325 mi (523 km) long, rising in N central Pa., and flowing NW into N.Y., then SW through Pa. to the Monongahela, with which it forms the Ohio R...

color index

(Encyclopedia)color index, in astronomy, difference in an object's brightness as recorded between any two well-defined bands of the electromagnetic spectrum by using optical filters of different colors. If blue and...

Haber process

(Encyclopedia)Haber process häˈbər [key], commercial process for the synthesis of ammonia, NH3. Pure hydrogen and nitrogen gases are mixed in the appropriate proportion, heated to between 450℃ and 600℃, comp...

Groningen, province, Netherlands

(Encyclopedia)Groningen grōˈnĭng-ən [key], province, c.900 sq mi (2,330 sq km), NE Netherlands, bordering on ...