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pipe

(Encyclopedia)pipe, hollow structure, usually cylindrical, for conducting materials. It is used primarily to convey liquids, gases, or solids suspended in a liquid, e.g., a slurry. It is also used as a conduit for ...

radio-frequency identification

(Encyclopedia)radio-frequency identification (RFID), a technology that uses radio waves to transmit data and uniquely identify an animal, person, or thing. An RFID system typically consists of a tag and a reader. T...

polymer

(Encyclopedia)CE5 A. Addition polymerization: Two ethylene molecules, C2H4, combine to form two links in the polyethylene chain molecule (C2H4)n. B. Condensation polymerization: Two glycine molecules, NH2CH2COOH...

Venus, in astronomy

(Encyclopedia)Venus, in astronomy, 2d planet from the sun; it is often called the evening star or morning star and is brighter than any object in the sky except the sun and the moon. Because its orbit lies between ...

viscosity

(Encyclopedia)viscosity, resistance of a fluid to flow. This resistance acts against the motion of any solid object through the fluid and also against motion of the fluid itself past stationary obstacles. Viscosity...

cocaine

(Encyclopedia)cocaine kōkānˈ, kōˈkān [key], alkaloid drug derived from the leaves of the coca shrub. A commonly abused illegal drug, cocaine has limited medical uses, most often in surgical applications that ...

Eswatini

(Encyclopedia)CE5 Eswatini or eSwatini, formerly Swaziland swäˈzēlănd [key],...

molecule

(Encyclopedia)molecule mŏlˈəkyo͞ol [key] [New Lat.,=little mass], smallest particle of a compound that has all the chemical properties of that compound. A single atom is usually not referred to as a molecule, a...

chemistry

(Encyclopedia)chemistry, branch of science concerned with the properties, composition, and structure of substances and the changes they undergo when they combine or react under specified conditions. Organic chemi...

crater

(Encyclopedia)crater, circular, bowl-shaped depression on the earth's surface. (For a discussion of lunar craters, see moon.) Simple craters are bowl-shaped with a raised outer rim. Complex craters have a raised ce...