March 4, 2002
For more information on these science news and feature
story tips, please contact the public information
officer at the end of each item at (703) 292-8070.
Editor: Josh Chamot
Contents of this News Tip:
Scientists
Discover New, Self-Repairing Plastic
A team of chemists and engineers has developed a strong,
transparent plastic that can mend itself if fractured.
The discovery is expected to lead to the creation
of self-repairing products for industrial, military
and scientific applications.
Fractures in the new polymer, called Automend, can
be healed without adding catalysts or other chemicals
by heating the material to 240-250 degrees Fahrenheit
(about 120 degrees Celsius). The National Science
Foundation (NSF)-funded scientific team was led by
Fred Wudl, director of the Exotic Materials Institute
at the University of California, Los Angeles (UCLA),
and reported its findings in the Mar. 1 issue of Science.
The material was created while Wudl's team was attempting
to produce a material as hard as diamond. The scientists
obtained additional funds to branch off into this
separate but related area of research. The special
provision is reserved for rare occasions when an accomplished
scientist is given the opportunity to extend his or
her primary research goals to pursue an equally promising
objective.
According to Wudl, the self-healing plastic is potentially
useful for products such as electronic devices that
heat and cool frequently and large lenses that would
retain their shape if cracked and repaired. Because
the material is transparent to electromagnetic waves,
it could be used to house radar or communications
equipment. [Amber Jones]
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New Materials
Key to Shrinking Memory Devices
Scientists at the University of Minnesota recently
announced a new milestone in the miniaturization of
logic and memory components for computers and other
electronic devices.
As devices shrink, so too must the thin films of silicon
oxide at the heart of the machines. However, at some
point the insulating properties of silicon oxide films
diminish.
Chemist Wayne L. Gladfelter and his colleagues, with
support from NSF, have perfected a method to optimize
the physical properties of high-dielectric materials.
These electrically insulating materials are being
considered as replacements for silicon oxide.
Gladfelter’s team has developed a chemical vapor method
of depositing three metal oxides on a single wafer
in various combinations to achieve size and performance
objectives. The researchers reported their results
in the February 2002 issue of Chemistry of Materials.
[Amber Jones]
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Researcher
Catalogs Vast Database of Traditional Plants Used
by Native Americans
A scholar at the University of Michigan-Dearborn has
compiled information on plants used by Native Americans
for foods, drugs, dyes and fibers -- more than 47,000
uses for nearly 4,000 species of plants.
Through an NSF grant of $256,000, anthropology professor
Daniel E. Moerman analyzed the relationship of the
4,000 species with the entire collection of plant
species in North America (about 28,000) and also their
relationship to plant species with medicinal value
(about 2,800).
Pharmacologists are uncovering medical applications,
such as the uses of cattail for treating burns, while
native groups are using the data to reconstruct habitats
and build native medicinal herb gardens. A school
district in the Four Corners region of the U.S. is
also using the database to put together a bilingual
(English and Navajo) website that shows how local
native people used plants. [Bill Harms]
For more information, see: http://www.umd.umichgian.edu/cgi-bin/herb
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Algorithms
For Airlines: New Math Model Saves Time, Money
To plan flight schedules, airlines must match capacities
with demands, and weigh the costs of non-stops flights
and "through" connections against the prices passengers
are willing to pay. In research partially funded
by NSF, a team of operations researchers and industrial
engineers developed a mathematical model that efficiently
identifies the most profitable assignment of planes
to flight legs and "through" connections.
The research team, led by James Orlin of the Massachusetts
Institute of Technology and Ravindra Ahuja of the
University of Florida, also developed the software
for the model.
United Airlines is adopting the mathematical model
to improve the efficiency of flight scheduling and
allow planning decisions within seconds.
Previously, an airline's ability to assign flights
in an integrated manner was impractical because of
the large amounts of computer time needed. Using
the more efficient software and mathematical model,
the researchers estimate, could save the airline as
much as $25 million annually.
The researchers are now expanding the model to include
additional criteria such as crew costs, reliability,
and flexible flight departure times. [Amber Jones]
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