For decades, researchers have been trying to make a material harder than a normal diamond, which industry could use for grinding and cutting tools. Sturdier diamond films should also benefit chips when silicon bumps into its physical limits around 2015. The heat that now plagues computers from ever-faster transistors would be of scant concern, since diamond chips could function at temperatures up to 1,000C.
A team led by scientists at Carnegie Institution of Washington created the new diamonds, which are grown from carbon vapors, then heated to 2,000C under extreme pressures for 10 minutes. They knew they had something special when the diamonds broke the hardness-measuring device. The wastewater that homes and businesses flush away may soon be more than just a drain on municipal budgets. Engineers at Pennsylvania State University have developed a fuel cell that uses sewage to generate electricity. Called a microbial fuel cell (MFC), the prototype is a glass tube no bigger than a king-size beer can. While the juice it generates wouldn't light even a mini Christmas-tree bulb, project head Bruce E. Logan says that will improve. For removing the organic matter in sewage, it's already 78% efficient.
Ordinary fuel cells produce power by harnessing the electrons from a chemical reaction between hydrogen and oxygen. With the new design, the electrons come from bacteria normally found in sewage while they consume its organic matter as food. Logan hopes MFCs will trim the $25 billion annual bill for wastewater treatment in the U.S. Synthetic-aperture radar (SAR) has revolutionized reconnaissance by peering through clouds and darkness to create photo-quality images. Compared with old clock hands sweeping around a screen and showing blips, SAR is like jumping from a flashlight to sunlight.
But it's too heavy for the small robot planes the Pentagon provides to ground troops for speedy surveillance. Now, Sandia National Laboratories has slashed the weight of a prototype SAR by 75%, down to 30 pounds. That's light enough to be carried by AAI Corp.'s Shadow 200, with a wingspan of 13 feet, which used to make do with video cameras. (Using video to spot suspicious people or vehicles is like hunting for a football by scanning the stadium through a drinking straw.)
Consumer uses could be next. California Institute of Technology's Ali Hajimiri recently unveiled a cheap radar chip, which could lead to car radar that pierces fog and blinding rain to show what's ahead on a windshield display. -- Skeptics of global warming assert that the dire effects attributed to greenhouse gases are largely the result of the imperfect computer models used by researchers. But a growing body of empirical data is harder to deny. In the Mar. 5 Science, University of Bern researchers show that average summer temperatures in Europe from 1994 to 2003 made up one of the hottest spells in five centuries. And the 30-year average from 1973 to 2002, for both winter and annual temperatures, also topped the 500-year record.
-- In the U.S., meanwhile, North Carolina State University scientists are marking the steady northward march of a rapacious, non-native vine called kudzu. Its unchecked expansion could bode ill for crops, they say. Kudzu is familiar in the South, but the weed recently spread to Massachusetts, where it formerly couldn't survive the winter. Warmer winters, says horticulturist Mary M. Peet, also mean southern fruit trees won't produce as many flowers. And since North Carolina's killing frost now doesn't come until November, more bugs survive to prey on trees and crops.