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New York, New Haven, and Hartford RR

(Encyclopedia)New York, New Haven, and Hartford RR, commonly called the New Haven RR; inc. 1872. Between 1872 and 1920, when dozens of small railroads were completed under the direction of financier John P. Morgan ...

Nernst, Walther Hermann

(Encyclopedia)Nernst, Walther Hermann välˈtər hĕrˈmän nĕrnst [key], 1864–1941, German physicist and chemist, a founder of modern physical chemistry. After doing outstanding research on osmotic pressure and...

Ohm's law

(Encyclopedia)Ohm's law ōm [key] [for G. S. Ohm], law stating that the electric current i flowing through a given resistance r is equal to the applied voltage v divided by the resistance, or i=v/r. For general app...

waveguide

(Encyclopedia)waveguide, device that controls the propagation of an electromagnetic wave so that the wave is forced to follow a path defined by the physical structure of the guide. Waveguides, which are useful chie...

Wood, Robert Williams

(Encyclopedia)Wood, Robert Williams, 1868–1955, American physicist, b. Concord, Mass., grad. Harvard (B.A., 1891). After studying abroad he became associated with Johns Hopkins as professor of experimental physic...

Birkeland, Kristian

(Encyclopedia)Birkeland, Kristian or Olaf Christian krĭsˈtyän bērˈkəlän, ōˈläv [key], 1867–1917, Norwegian physicist. From 1898 Birkeland was a professor at the Univ. of Christiania (now Oslo). Noted fo...

Saratov

(Encyclopedia)Saratov səräˈtəf [key], city (1991 est. pop. 910,000), capital of Saratov region, E European Russia, on the Volga River. It is a major industrial, transportation, and cultural center of the lower ...

corrosion

(Encyclopedia)corrosion, atmospheric oxidation of metals (see oxidation and reduction). By far the most important form of corrosion is the rusting of iron. Rusting is essentially a process of oxidation in which iro...

lead, chemical element

(Encyclopedia)lead, metallic chemical element; symbol Pb [Lat. plumbum]; at. no. 82; at. wt. 207.2; m.p. 327.502℃; b.p. about 1,740℃; sp. gr. 11.35 at 20℃; valence +2 or +4. One of the oldest metals used by h...

energy, sources of

(Encyclopedia)energy, sources of, origins of the power used for transportation, for heat and light in dwelling and working areas, and for the manufacture of goods of all kinds, among other applications. The develop...