Coiling a ceramic superconductor.Coiling a ceramic superconductor A material that has little resistance to the flow of electricity. Traditional superconductors operate at absolute zero (-459.67 degrees Fahrenheit or -273.15 degrees Celsius). Experiments in the 1980s raised the temperature to -321 degrees Fahrenheit. Stretched end to end, the superconducting su·per·con·duct·ing adj. Having, exhibiting, or capable of superconductivity: "a revolutionary superconducting magnetic propulsion system" Colin Nickerson. wire in the coil shown below spans 30 feet. Though it can carry only a tenth of the current needed for building practical electrical motors, it represents a step toward such devices, says ceramics engineer Stephen E. Dorris, who helped develop the wire at Argonne (Ill.) National Laboratory. Reaching lengths of up to 50 feet, the Argonne wires may be the longest superconducting strands around, he asserts. Already, Reliance Electric Co. in Cleveland has used one of these coils in a small, experimental motor, with which the company hopes to study technical challenges to building larger superconducting motors for use by the electric utility industry. "Efficiency losses in a superconducting motor are less than half those in a conventional motor," notes research manager James S. Edmonds of the Electric Power Research Institute in Palo Alto Palo Alto, city, California Palo Alto (păl`ō ăl`tō), city (1990 pop. 55,900), Santa Clara co., W Calif.; inc. 1894. Although primarily residential, Palo Alto has aerospace, electronics, and advanced research industries. , Calif., which funds the work. Unlike coils made with copper and other normally conductive metals, which pose varying degrees of energy-sapping resistance to electrical current, the superconducting coils can carry current with no resistance whatsover so long as they are held at liquid nitrogen Noun 1. liquid nitrogen - nitrogen in a liquid state atomic number 7, N, nitrogen - a common nonmetallic element that is normally a colorless odorless tasteless inert diatomic gas; constitutes 78 percent of the atmosphere by volume; a constituent of all living temperatures (77 kelvins). The Argonne researchers made their coil out of the superconducting ceramic yttrium-barium-copper-oxide, also known as "1-2-3." The process involves mixing 1-2-3 powder with some acrylic resin and strength-giving silver and extruding the malleable malleable /mal·le·a·ble/ (mal´e-ah-b'l) susceptible of being beaten out into a thin plate. mal·le·a·ble adj. 1. Capable of being shaped or formed, as by hammering or pressure. mixture into a wire, which then gets a coating of "2-1-1" power -- 2 parts yttrium yttrium (ĭt`rēəm) [for Ytterby, a town in Sweden], metallic chemical element; symbol Y; at. no. 39; at. wt. 88.9059; m.p. about 1,522°C;; b.p. 3,338°C;; sp. gr. about 4.45; valence +3. Yttrium is a highly crystalline iron-gray metal. and 1 each of barium and the oxide. The scientists wind the preparation into a coil and then heat it. The heat treatment burns off the acrylic while sintering sintering, process of forming objects from a metal powder by heating the powder at a temperature below its melting point. In the production of small metal objects it is often not practical to cast them. the 1-2-3 powder into a continuous coil and the 2-1-1 into a green-colored insulating coat. "We used the 2-1-1 modification as an insulator because other materials interferred with the chemical properties of the superconducting wire when the coil was fired in a furnace," explains Argonne's Roger Poeppel. |
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