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fireproofing

(Encyclopedia)fireproofing, method of making normally combustible materials as nearly noncombustible as possible. Fireproofing generally applies to textiles and construction materials that are treated with a soluti...

fault

(Encyclopedia)CE5 Types of faults fault, in geology, fracture in the earth's crust in which the rock on one side of the fracture has measurable movement in relation to the rock on the other side. Faults on othe...

pearl, gem

(Encyclopedia)pearl, hard, rounded secretion formed inside the shell of certain mollusks, used as a gem. It is secreted by the epithelial cells of the mantle, a curtain of tissue between the shell and body mass, an...

data encryption

(Encyclopedia)data encryption, the process of scrambling stored or transmitted information so that it is unintelligible until it is unscrambled by the intended recipient. Historically, data encryption has been used...

Roman roads

(Encyclopedia)Roman roads, ancient system of highways linking Rome with its provinces. Their primary purpose was military, but they also were of great commercial importance and brought the distant provinces in touc...

semiconductor

(Encyclopedia)CE5 N-type and P-type crystals: In a pure silicon crystal each silicon atom (Si) is surrounded by four valence electrons. In the N-doped semiconductor, illustrated in the left-hand figure, some sil...

potato

(Encyclopedia)potato or white potato, common name for a perennial plant (Solanum tuberosum) of the family Solanaceae (nightshade family) and for its swollen underground stem, a tuber, which is one of the most widel...

plate tectonics

(Encyclopedia)CE5 Plate tectonics: Map of the world showing major plates and plate boundaries CE5 Plate tectonics: Schematic model of the oceanic crust, showing the three types of plate boundaries plate tect...

Platyhelminthes

(Encyclopedia)CE5 A. Planaria, representative of the phylum Platyhelminthes B. Internal anatomy of Planaria Platyhelminthes plătˌēhĕlmĭnˈthēz [key], phylum containing about 20,000 species of soft-bodied,...

Pinophyta

(Encyclopedia)Pinophyta pīˌnŏfˈətə [key], division of the plant kingdom consisting of those organisms commonly called gymnosperms. The gymnosperms, a group that includes the pine, have stems, roots and leaves...