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Food and Drug Administration

(Encyclopedia)Food and Drug Administration (FDA), agency of the Public Health Service division of the U.S. Department of Health and Human Services. It is charged with protecting public health by ensuring that foods...

stellar structure

(Encyclopedia)stellar structure, physical properties of a star and the processes taking place within it. Except for that of the sun, astronomers must draw their conclusions regarding stellar structure on the basis ...

Waxman, Henry Arnold

(Encyclopedia)Waxman, Henry Arnold, 1939–, U.S. congressman, b. Los Angeles, grad. Univ. of California, Los Angeles. (B.A., 1961; J.D., 1964). After serving (1969–74) in the California state assembly, he won (1...

sun, in astronomy

(Encyclopedia)CE5 Structure of the sun sun, intensely hot, self-luminous body of gases at the center of the solar system. Its gravitational attraction maintains the planets, comets, and other bodies of the sola...

genetic engineering

(Encyclopedia)CE5 Genetic engineering: Gene-splicing techniques genetic engineering, the use of various methods to manipulate the DNA (genetic material) of cells to change hereditary traits or produce biologica...

perpetual-motion machine

(Encyclopedia)perpetual-motion machine, device that would be able to operate continuously and supply useful work, in violation of the laws of thermodynamics. A machine that would produce more energy in the form of ...

proton

(Encyclopedia)proton, elementary particle having a single positive electrical charge and constituting the nucleus of the ordinary hydrogen atom. The positive charge of the nucleus of any atom is due to its protons....

voltaic cell

(Encyclopedia)voltaic cell, a simple device with which chemical energy is converted into electrical energy. Two dissimilar metals (e.g., copper and zinc) are immersed in an electrolyte (e.g., a dissolved sulfate). ...

breakwater

(Encyclopedia)breakwater, offshore structure to protect a harbor from wave energy or deflect currents. When it also serves as a pier, it is called a quay; when covered by a roadway it is called a mole. In the Unite...

Higgins, William

(Encyclopedia)Higgins, William, b. 1762 or 1763, d. 1825, Irish chemist. After study at Oxford he became supervisor of the Royal Dublin Society's mineralogical collection and in 1800 the Society's professor of chem...