Developments to Watch
Edited by Adam Aston
Homemade Drinking Water, for a Pittance
Bottled water drinkers may soon get a lower-cost alternative. Ovation Products Corp. in Nashua, N.H., is testing a new home appliance that purifies water for about 1/4 cents per gallon. Ovation has figured out a way to conduct so-called vapor compression distillation (VCD) in a unit the size of a fire hydrant that can spew out 12 to 20 gallons of distilled water per hour.
Large VCD systems have been in service for decades, purifying water at offshore oil rigs and water bottling plants. Ovation's CEO William H. Zebuhr was able to scale-down the technology by using a super-efficient rotating heat exchanger. His patented design circulates steam from tainted water back around to help vaporize more incoming water. As it gives up its heat, the steam condenses into pure water. By getting the cost of the home unit down to around $1,000, Zebuhr hopes his design will become "the personal computer of the water-treatment business." Sales will begin next year.
By Aliya Sternstein
Can Frozen Atoms Predict Eruptions?
Scientists often try to predict volcanic eruptions by using lasers to study tiny gravitational changes in the surrounding earth. But using conventional light-based lasers, they have not been able to directly measure gravitational flux. That's because light waves spread out ever so slightly as they travel and are affected very little by gravity.
Now, researchers at Rice University in Houston and NASA's Jet Propulsion Laboratory in Pasadena, Calif., may have a solution. They freeze atoms and force them into tiny bundles of waves called solitons. Unlike light waves, soliton waves keep their shape as they travel. And because atoms have weight--unlike photons---solitons respond in an easily measured fashion to gravity shifts. "The degree of sensitivity with an atom-wave gravity meter would be a million times better," says Dr. Lute Maleki, principal investigator for the Quantum Gravity Gradient Project at JPL.
Atom-wave lasers may have uses away from volcanos. They could someday be used to create 3-D maps of caves or even of underground oceans on other planets. And they could play a role in hyper-accurate gyroscopes or help etch superfast computer chips.
By Arlene Weintraub
Generating Power with the World's Tallest Tower
Little grows in the arid flatlands of southeast Australia. But a 3,000-foot chimney could sprout there next year, becoming the world's tallest structure. By 2005, this concrete Solar Tower could start converting the desert's abundant heat into green power, relying simply on the fact that hot air rises. To be built by Melbourne-based EnviroMission Ltd., the tower will be surrounded by a 4.3-mile-wide glass-roofed enclosure. This huge greenhouse will preheat the desert air, which will rise in the enclosure and flow towards the base of the 420-foot-wide tower. There, a steady 35 mph updraft will drive 32 wind turbines, which will pump out 200 megawatts of power. The hot air will shoot up and out of the chimney's top, where the atmosphere is some 65F cooler. "We're well past the ideas stage," says Roger Davey, EnviroMission's CEO, who is negotiating with potential power buyers to help finance the project. At $380 million, the Solar Tower is twice the cost of a wind farm of a similar capacity. But the tower is more reliable, as it makes its own wind. And Davey says costs will fall once the first of five planned towers is built. Now, in a partnership with Energen Global Inc. in Westlake Village, Calif., EnviroMission is evaluating sun-baked sites in the southwestern U.S., which could be fertile ground for more solar towers.
Innovations
-- Pointing the way to a superstrong dry adhesive, researchers at Oregon's Lewis & Clark College and three California schools have duplicated the gecko lizard's wall-sticking ability by making artificial hairs just like those on the reptile's feet. Geckos can scamper up the slickest surfaces, or even hang upside down, using no adhesive or suction, thanks to these tiny hairs. That's because every hair sports a thousand pads--each only 200 billionths of a meter wide--so small that they bond to practically any surface using an esoteric physical reaction called van der Waals force.
-- Fuel cells will soon be giving birth to fuel cells. On Sept. 2, Celanese Ventures in Frankfurt will cut the ribbon on a new manufacturing line, powered by fuel cells, for cranking out modules containing proton exchange membranes. These are the guts of fuel cells being developed by Honda Motor, Plug Power, and others. The membrane is made from polybenzimidazole (PBI), a polymer now used in firefighters' protective garments because it can withstand high heat. The PBI modules will double fuel-cell operating temperatures to 200C, Celanese says, boosting both efficiency and longevity.
-- This year, of the roughly 600,000 Americans who will suffer a stroke, some 150,000 will die, and many others will experience brain damage. But Vallie Holloway, a researcher at Loyola University Medical Center in Maywood, Ill., may have found a way to lower this toll. In laboratory tests on rats, Holloway showed that lineoleic acid--produced by sunflowers and other plants--can lower stroke-causing high blood pressure. It also helps curb brain damage after a stroke.
By Otis Port
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Copyright 2002, by The McGraw-Hill Companies Inc. All rights reserved.
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