Developments to Watch
A JET ENGINE THAT CAN RUN A DRYER
A NEW GENERATION OF MODified jet-airplane engines could soon be generating the electricity for your microwave oven.
General Electric Co. already sells an electricity-generating version of its CF6 jet engine, which is used on the Boeing 747. Such engines are good where electricity is needed on short notice, such as in developing nations--or currently in Connecticut. All four of that state's nuclear plants are shut down.
But a consortium based in Lafayette, Calif., called Collaborative Advanced Gas Turbine LLP aims to broaden the niche for jet turbines. The idea is to use versions of engines developed for the Boeing 777 by Pratt & Whitney, Rolls-Royce, and GE, such as the GE90 (photo). The group's president, George A. Hay III, says that efficiency for generation could be boosted by "intercooling"--cooling the incoming air between the engine's first and second compressor stages. Backed by the Electric Power Research Institute and the Gas Research Institute, among others, the consortium plans to work with one of the big jet-engine makers, which it won't name, to develop an intercooled engine.
The timing is right: Under deregulation, utilities are interested in power sources that they can turn on and off quickly to meet transitory demand.EDITED BY PETER COYReturn to top
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AND YOU THOUGHT `COLD-FILTERED' WAS FOR BEER
ILLINOIS SUPERCONDUCTOR Corp. is giving new meaning to "cold calling." It has developed a noise filter for cellular phone networks that operates at 320F. The filter suppresses the noise from airwave frequencies adjacent to cellular phone channels so that the radio receivers in the base stations get a cleaner signal.
Ordinary filters for cellular base stations look like long shoe boxes with up to a dozen finger-size rods inside. The rods--usually made of copper or aluminum and coated with silver--resonate at the frequencies of the cellular calls, letting those calls slip through easily. All other frequencies get bounced back or weakened by the rods. Silver is used because it conducts the calls' electrical energy well. But the company uses a superconducting compound of yttrium, barium, and copper oxide that conducts even better--as long as it's cooled with a special refrigerator that uses helium as its compressible gas.
The Mt. Prospect (Ill.) company claims its filter suppresses out-of-band noise 1,000 to 10,000 times as well as conventional filters. The price is about $8,000, which is anywhere from 2 to 10 times as much as other filters. Its first customer, Southwestern Bell Mobile Systems, is buying six sets for cellular antennas in areas where interference is especially troublesome.EDITED BY PETER COYReturn to top
BRAIN CELLS TO SPARE?
POPULAR WISDOM HOLDS that your brain cells die off in massive numbers as you get older and don't get replaced. The reality isn't quite so bleak. Neurons are constantly being born in several regions of the brain, including the hippocampus, which handles learning and memory. The neurons mature from versatile stem cells known as adult hippocampal progenitor cells, or AHPs. And one day it might be possible to transplant these cells to help out other parts of the brain, say neurobiologist Fred H. Gage and colleagues at the Salk Institute for Biological Studies in La Jolla, Calif.
In an experiment described in the Oct. 17 issue of Nature, the Salk team cultured AHP cells from the hippocampus of rats, then transplanted them into the olfactory region of the brain, which controls smell. The cells began acting as though they belonged there, expressing proteins appropriate to that region. If human stem cells behave similarly, the experiment could lead to treatments for brain injuries and neurological ills such as Parkinson's. The Salk team wants to understand--and later control--the signals that cause AHP cells to mature into different types of brain cells. Then they could create an unlimited supply of cells to produce chemicals the brain needs.EDITED BY PETER COY By Neil GrossReturn to top