in the News
Two-Pronged Attack on Bioterrorism
Optics Sharpen the View from Earth
Re-Create X Rays from Comets
50 Years of Exploring the Material World
in the News
treatment by wire
A springy plastic wire that
changes shape at the flick of a switch could provide a safer treatment
for strokes caused by blood clots. Developed by engineers at Livermore,
the wire, made from shape-memory polymer, will allow surgeons to
remove blood clots from the brain without using potentially dangerous
The shape-changing wire is
made from two types of polyurethane bundled into one. One type is
harder than the other. Team member Duncan Maitland explains that
the wires main body is constructed from the softer material,
with chunks of the harder material distributed though it.
The wire is first heated
to allow both its hard and soft components to become malleable.
The end of the wire is then twisted into a coil and cooled, fixing
the shape of the coil into the polymer. Next, the wire is reheated
but to a lower temperature
than it was initially, so that only the softer part is deformed.
The coil is pulled to straighten it and then cooled again to harden
it. It becomes too rigid to spring back into the coiled shape. However,
when heated again to 60°C, the plastic softens sufficiently
for the end of the wire to spring back into a coil.
Maitland and his colleagues
have tested their invention by conducting in vitro experiments using
pigs blood. They fixed the wire to the end of an optical fiber
and inserted both into a narrow catheter. They speared a clot with
the wire, withdrew the catheter, and heated the wire with infrared
light transmitted through the fiber. The wire changed into
a coil in a fraction of a second, says Maitland. It grips
the clot from behind, and the clot is pulled out with the wire.
Contact: Duncan Maitland (925) 423-6697 (firstname.lastname@example.org).
combustion method lowers power plant emissions
Livermore engineers have
developed a unique combustion method that combines staged combustion
with nitrogen-enriched air to lower power plant pollutant emissions.
The new technology, called
staged combustion with nitrogen-enriched air (SCNEA), could help
power plants comply with strict Environmental Protection Agency
(EPA) requirements for decreasing power plant emissions. As
EPA requirements become tighter and tighter on emissions, most solutions
become more difficult and more expensive to implement, says
Larry Fischer, principal investigator for SCNEA. With our
technology, consumers will see cleaner air at a miniscule increase
in their utility bills.
Before concerns about oxides
of nitrogen (NO and NO2, often called NOx) and their relationship
to photochemical smog and acid rain arose in the late 1980s, power
plants typically burned fuel in boilers and furnaces with single-stage
combustion using air as the oxidant. Today, NOx emissions are regulated
under provisions of the Clean Air Act and its amendments. Those
regulations will become tougher by 2005, which means that the technologies
used to lower NOx emissions must be improved.
SCNEA lowers NOx emissions
with a combustion method that burns fuels in two or more stages.
In the first stage, fuel is combusted with nitrogen-enriched air.
The fuel remaining after the first stage is combusted in the remaining
stage(s) with air or nitrogen-enriched air. This method substantially
reduces NOx emissions without significantly reducing power plant
efficiency and is applicable to many types of combustion equipment
and many types of fuels.
Livermore is working to form
a consortium of representatives from the U.S. EPA, utility companies,
boiler manufacturers, emission control equipment companies, and
a company that produces nitrogen-enriched air to further develop
SCNEA. The next stage is a small-scale pilot program.
Contact: Larry Fischer (925) 423-0159 (email@example.com).
A Livermore team has completed
a 28-kilometer, high-capacity laser communication link between the
Laboratory and Mount Diablo. This represents one of the longest
terrestrial high-capacity air-optics links in existence, says
Tony Ruggiero, principal investigator on the project to develop
an optical wireless testbed for evaluating new laser communication
Laser communication consists
of an optical system in which information is encoded on a laser
beam and transmitted to a receiver telescope. Functionally similar
to radiofrequency or microwave communications, lasers use the optical
part of the electromagnetic spectrum. The laser communication beam
not visible or harmful in any way.
The initial LaboratoryMount
Diablo link transmitted data at a single-channel data rate of 2.5
gigabits per secondthe equivalent to the transmission of 1,600
conventional T1 data lines, 400 TV channels, or 40,000 simultaneous
The experiments are being
conducted as part of the Secure Air-Optic Transport and Routing
Network (SATRN) program, which is cosponsored by the Nonproliferation,
Arms Control, and International Security Directorate and Laboratory
Directed Research and Development to provide advanced technologies
for long-range laser communications.
counterproliferation, arms control, counterterrorism, and warfighting
all require the timely and secure communication of information in
situations where fiber-optic cable is physically or economically
impractical and data requirements exceed radiofrequency or microwave
Ruggiero says that the next
challenge for the SATRN team is transmitting data long distances
for longer periods of time to establish a solid baseline for the
availability, accessibility, and acceptability of the systems
single-channel long-range link performance.
Contact: Tony Ruggiero (925) 423-1020 (firstname.lastname@example.org).
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June 14, 2002