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BY GAIL
HELGASON
Freelance Writer
A new boarding-pass analyzer may be able to identify an airline
passenger who has been handling explosives, reports the Engineering
News-Record (New York). About the size of a small copy machine,
the device uses spectrometry to detect as little as a billionth
of a gram of explosives such as TNT and nitroglycerine. These
substances linger on the body for days and are easily transferred
to things they touch - even a boarding pass.
Dr. Michael Kuliasha of the Oak Ridge National Laboratory
in Tennessee developed the device with Mass Spec Analytical
of England. Even if a person were wearing protective clothing
while handling explosives, he says, the analyzer would likely
make a detection. Although the scanners currently cost $250,000,
commercialization is expected to drive the price down.
Plastic on the Range
Chemical Engineering (Washington, D.C.) reports that plastic
has been produced in the leaves of alfalfa plants through
genetic manipulation. Scientists at the U.S. Department of
Agriculture Plant Science Research Unit in St. Paul, Minn.,
took several genes from Ralstonia, a bacterium that produces
the plastic naturally, and incorporated them into the plant's
tissues.
The biodegradable plastic, polyhydroxybutyrate, is quite
brittle but might be used as a copolymer in consumer products
and medical devices. Although yields so far are only 1.8 grams
of plastic per dry kilogram of alfalfa, researchers think
these can be improved.
The publication also reports that the first world-scale plant
to produce commercial-grade plastic resins from biomass has
opened in Blair, Neb. The Cargill Dow LLC plant uses a multi-step
process in which dextrose is produced from corn, then fermented
into lactic acid, converted to a lactide, purified by distillation,
and then formed into polylactide with a catalyst. The polymer
is used to make fibres, bottles and films.
Marketable Hydrogen Cells Developed
A fuel cell development company in New Jersey expects to
start shipping 500-watt commercial products, Mechanical Engineering
(New York) reports. The units, produced by H Power Corp. of
Belleville, N.J., can be mounted in a standard equipment rack
and have an output of 120 volts of alternating current at
60 Hz. The units use the standard compressed gas cylinders
found in welding stores. They are designed for use as backup
power for communications or industrial purposes.
Lightweight Composite Boosts Wind Turbines
A super-strong composite developed at Brigham Young University
in Utah might allow construction of wind turbine towers up
to three times the height of the steel towers typically installed
today, reports Power Engineering (Tulsa, Okla.). The increase
in turbine height could also increase the upper end of wind
turbine capacity to as much as five megawatts from the current
1.5 to two megawatts.
The composite, called Pyramatrix, is the result of seven
years of research by Dr. David Jensen and his civil engineering
students. The substance is 91 per cent lighter than steel
and 76 per cent lighter than aluminum. It owes its strength
to its carbon-fibreglass filaments and geometry, with the
composite woven into a variety of hollow lattices of reinforcing
pyramids. The professor says the lower weight could mean significantly
lower transportation and installation costs than those associated
with tubular steel towers.
Let's Talk Turkey Power
The first U.S. powerplant to be fueled by poultry manure
was expected to start construction by the end of 2002. The
Engineering News-Record (New York) reports that the proposed
$100-million plant, which recently received a draft air quality
permit, would burn up to 500,000 tons of turkey manure a year.
The 50-megawatt plant, developed by a subsidiary of the U.K.-based
Fibrowatt Group, will be designed and built by SNC Lavalin
of Vancouver. Fibrowatt sees a growing demand for biomass
plants due to concerns about runoff from large agricultural
operations.
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