If magnetic data-storage
devices for computers could be pushed into the wavelength limit of an electron moving
through a solid -- the nanometer scale -- storage capacity could be significantly
increased. The key is to confine the movement of the electron. Researchers have taken a
significant step toward that end, producing the first high quality images of "quantum wells"
-- an energy state in which an electron is sandwiched between two layers of atoms so that
its motion is confined to a single dimension.
Many unanswered questions remain
about how air pollution affects health. For instance, many pollutants exist in both
particle and gas phases, which are deposited differently in the lungs and have different
physiological effects. Difficulty in getting good measurements of these gas and solid
phases has complicated the EPA's effort to establish air quality standards. Lara Gundel
and colleagues have devised an air
sampler that is being used around the country to resolve these issues.
Scientists at the Lab's Center for Environmental Biotechnology have shown that underground
microbes can transform
toxic chromium pollutants into less toxic compounds. What's more, the process may be
accelerated by the presence of volatile organic wastes, compounds often found at
contaminated sites. These findings point the way toward new, environmentally benign
remediation techniques for cleaning up mixed waste sites.