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phosphorescence

(Encyclopedia)phosphorescence fŏsˌfərĕsˈəns [key], luminescence produced by certain substances after absorbing radiant energy or other types of energy. Phosphorescence is distinguished from fluorescence in th...

Phyfe, Duncan

(Encyclopedia)Phyfe, Duncan fīf [key], c.1768–1854, American cabinetmaker, b. Scotland. He emigrated to America c.1783, settling at Albany, N.Y., where he was apprenticed to a cabinetmaker. In the early 1790s he...

chromatography

(Encyclopedia)chromatography krōˌmətŏgˈrəfē [key], resolution of a chemical mixture into its component compounds by passing it through a system that retards each compound to a varying degree; a system capabl...

sulfur

(Encyclopedia)CE5 Sulfur crystals sulfur or sulphur sŭlˈfər [key], nonmetallic chemical element; symbol S; at. no. 16; interval in which at. wt. ranges 32.059–32.076; m.p. 112.8℃ (rhombic), 119.0℃ (mon...

solution

(Encyclopedia)CE5 Solubility curves solution, in chemistry, homogeneous mixture of two or more substances. The dissolving medium is called the solvent, and the dissolved material is called the solute. A solutio...

environmentalism

(Encyclopedia)environmentalism, movement to protect the quality and continuity of life through conservation of natural resources, prevention of pollution, and control of land use. The philosophical foundations for ...

analytic geometry

(Encyclopedia)analytic geometry, branch of geometry in which points are represented with respect to a coordinate system, such as Cartesian coordinates, and in which the approach to geometric problems is primarily a...

dimension, in mathematics

(Encyclopedia)dimension, in mathematics, number of parameters or coordinates required locally to describe points in a mathematical object (usually geometric in character). For example, the space we inhabit is three...

Correa Delgado, Rafael Vicente

(Encyclopedia)Correa Delgado, Rafael Vicente räfäālˈ vēsānˈtā kōrāˈä delgäˈᵺō [key], 1963–, Ecuadorian economist and political leader, president of Ecuador (2007–2017), b. Guayaquil. A leftist ...

cire perdue

(Encyclopedia)cire perdue sēr pĕrdüˈ [key] [Fr.,=lost wax], sculptural process of metal casting that may be used for hollow and solid casting. The sculptor makes a model in plaster or clay that is then coated w...