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photochemistry

(Encyclopedia)photochemistry, study of chemical processes that are accompanied by or catalyzed by the emission or absorption of visible light or ultraviolet radiation. A molecule in its ground (unexcited) state can...

Rogers, Richard George, Baron Rogers of Riverside

(Encyclopedia)Rogers, Richard George, Baron Rogers of Riverside, 1933–2021, British architect, b. Florence, Italy, Architectural Association, London (A.A. Dipl....

die-casting

(Encyclopedia)die-casting, process by which molten metal is forced by a plunger or compressed air into a metallic die and the pressure maintained until the metal has solidified. Die castings are accurate, are sharp...

Parsons, Sir Charles Algernon

(Encyclopedia)Parsons, Sir Charles Algernon, 1854–1931, British engineer. He invented a revolutionary steam turbine that bears his name. His first turbines were constructed to drive generators to produce electric...

bioluminescence

(Encyclopedia)bioluminescence bīˌōlo͞oˌmĭnĕsˈəns [key], production of light by living organisms. Organisms that are bioluminescent include certain fungi and bacteria that emit light continuously. The dinof...

Meghna

(Encyclopedia)Meghna mĕgˈnə [key], river, c.130 mi (210 km) long, formed at the outlet of the Surma valley, NE Bangladesh, by the branches of the Surma River. It flows south, receiving arms of the Ganges and Bra...

nucleosynthesis

(Encyclopedia)nucleosynthesis or nucleogenesis, in astronomy, production of all the chemical elements from the simplest element, hydrogen, by thermonuclear reactions within stars, supernovas, and in the big bang at...

optics

(Encyclopedia)optics, scientific study of light. Physical optics is concerned with the genesis, nature, and properties of light; physiological optics with the part light plays in vision; and geometrical optics with...

Heiden, Eric

(Encyclopedia)Heiden, Eric hīˈdən [key], 1958–, American speed skater, b. Madison, Wis. After competing in the 1976 Winter Olympics, he won three consecutive World Speedskating Championships (1977–79). In 19...

Raman effect

(Encyclopedia)Raman effect räˈmən [key], appearance of additional lines in the spectrum of monochromatic light that has been scattered by a transparent material medium. The effect was discovered by C. V. Raman i...