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Hope for Sore Joints * Synthetic Rope Stronger than Steel * Acrobatic Helicopter * Alternatives to Landfilling * Long and Prosperous Career * Learning What Makes Cities Work
Hope for Sore Joints
Researchers at Rensselaer Polytechnic Institute are developing
computer models of joints that could lead to a diagnostic tool for osteoarthritis,
the natural wear and tear of joints, and could make many hip replacements
unnecessary. Robert Spilker, chair of biomedical engineering at RPI, heads
the effort to accurately model cartilage within joints such as the knee,
hip, shoulder, and spine. Spilker and his colleagues simulate a functional
environment, such as the knee, through computer modeling that can recreate
the mechanical environment and stresses seen by a tissue. They're collaborating
with researchers at the Orthopedic Research Laboratory at Columbia University.
"There is more to characterizing tissue than just looking at biological structure and function," Spilker explains. "The properties in bones and cartilage vary within themselves and from person to person. Growing tissues such as cartilage is a major development, but making it function as a load-carrying material requires significant new engineering research." Currently, osteoarthritis can be detected only after cartilage thinning has occurred. But by this time, the functional properties of the tissue have already deteriorated significantly, making effective treatment such as drug delivery more difficult.
Patient-specific cartilage modeling could help physicians predict cartilage thinning. In addition, more accurate joint models mean more accurate, less invasive surgeries, says Spilker. Physicians could choose cartilage replacement surgery over hip replacement when bone fracture isn't involved -- Spilker says the option might be 10 years down the road. The challenge lies in creating patient-specific models, which requires massive computer resources. Spilker's goal is to make the process quick and easy.
Synthetic Rope Stronger than Steel
If U.S. Navy sailors reach the end of their rope, at least
their hands won't have rope burns. The U.S. Navy has awarded a contract
to Advanced Design Consulting (ADC) to develop the slickest and strongest
synthetic rope fibers yet for bitts, bullards, blocks, and other rope-pathway
components. An engineering firm based in Lansing, New York, ADC conducts
engineering design, research and development, testing, and custom fabrication.
The research team also includes Leigh Phoenix, Cornell University professor
of theoretical and applied mechanics; Petru Petrina, Cornell senior research
associate in civil engineering; and Richard Chaplin, professor of engineering
at Reading University in Reading, England.
ADC will also examine the fibrous jackets of rope, develop friction-control treatments that enable rope to slide more easily, and seek ways to retrofit rope-pathway components to accommodate the new technology. "New ropes must be strong enough and stiff enough to match the steel-wire ropes the Navy currently uses," says Alex Deyhim, president of ADC and principle investigator on the project. "At the same time, the ropes must be light and flexible for easy handling."
Steel-wire rope, used in loading cargo on ships, offers consistent stiffness and strength, regardless of the direction it is pulled in. Synthetic-fiber rope can't yet compete with steel because it performs differently when strained from different directions. So why replace steel-wire rope? While it does feature the advantage of strength, it's costly to maintain, mechanically complex, relatively inflexible, and heavy. In time, the Navy hopes, synthetic-fiber rope can match its steel-wire counterpart, with the additional benefits of flexibility, lighter weight, and lower maintenance costs. "Very favorable gains -- by up to a factor of five -- can be achieved by developing synthetic ropes," says Deyhim. With new synthetic material development, the Navy can soon begin using it in less-critical, cost-effective applications, he says.
Acrobatic Helicopter
Engineers at MIT are building a small robotic helicopter with
the potential to go places no other helicopter has gone before, according
to a report in Engineering Times. The researchers say the craft
could aid in military missions, help rescuers survey disaster sites, and
even provide the entertainment with aerial shots. The craft is designed
to fly at low altitudes and fit into tight spaces.
Last year, the team achieved what it called the first autonomous acrobatic maneuver with a helicopter when its X-Cell 60 model, equipped with a seven-pound instrumentation box, performed a corkscrew-like 360-degree aileron roll. Professor Eric Feron, the team's leader, says the accomplishment involved a combination of advanced modeling techniques, innovative control strategies, and judicious hardware choices.
Surprisingly, the helicopter has proven relatively easy to operate. A person with no training could fly it most of the time, though a pilot would be needed to perform takeoffs and landings. And despite the complexity of helicopters, it comes with a reasonable price tag. Manufacturing a craft for military use, one of the more pricey versions, would cost an estimated $500,000. The researchers point out that this would be a substantial savings over the $2 million price of the Predator unmanned craft used in high-risk missions in Afghanistan.
Alternatives to Landfilling
With landfills filling up and closing and communities resisting
new landfills in their area, the need for solid waste disposal planning
has taken on new emphasis in recent years. Three researchers at North
Carolina State University, along with colleagues at the nearby Research
Triangle Institute, have set out to help communities identify solid waste
management alternatives that consider recycling and composting and their
impacts on the environment. The trio includes Morton Barlaz, professor
and associate head of civil engineering; Ranji Ranjithan, associate professor
of civil engineering; and Downey Brill, professor of civil engineering
and head of the department.
The research group applies a technique called life cycle analysis, by which energy consumed (or produced) and emissions are calculated. They look at the overall effects of alternatives for integrated solid waste handling -- from collection of waste, recyclables, and yard waste to recycling and composting to waste combustion and disposal in landfills. The group has created a comprehensive and flexible approach to studying alternative solutions tailored for each community, which consider costs and environmental benefits. A prototype software system implements this approach.
Barlaz and company recently developed a hypothetical case study to see how the model would work. They studied different levels of recycling and showed how, in many cases, recycling can reduce emissions of greenhouse gases while also reducing dependence on landfills. Barlaz also points out that when methane gas produced in landfills is recovered for energy, the landfill actually produces more energy than it consumes, reducing the consumption of fossil fuels and air emissions associated with power production.
"Using the hypothetical case study, we've demonstrated how to identify
a range of solid waste alternatives, including least-cost solutions that
meet a 25-percent recycling target and don't exceed a certain amount of
greenhouse gas emissions, for example," Ranjithan says. "You
can explore and identify solutions that meet the requirements you specify.
I think the model has a lot of potential to help communities."
Long and Prosperous Career
Known as "Mr. Refrigeration" throughout the worldwide ammonia
refrigeration industry, Milt Garland died in July, 2000, a month before
his 105th birthday. Honored by President Clinton in 1998 as the Oldest
Working American, Garland worked every day at the Frick plant of York
Refrigeration in Waynesboro, Pennsylvania until shortly before his death.
The town of Waynesboro had recently honored his 80th consecutive year
of employment.
Garland began his career at Frick in 1920, and by 1928, he had become
superintendent of field operations. He eventually served as vice president
of both engineering and technical services at Frick. Countless engineers
and technicians from around the world will remember him as their teacher.
Until just five years ago, Garland served as a regular instructor in the
training center that bears his name. During 2000, he actively engaged
in patent review for the company -- he held 37 patents of his own. In
1998, Garland became the first recipient of the prestigious Andy Ammonia
Award given by the International Institute of Ammonia Refrigeration. He
also earned several ASHRAE awards, including the society's highest engineering
achievement award, the F. Paul Anderson Medal.
Learning What Makes Cities Work
One afternoon, engineering students at Princeton piled into
a van for a field trip to the nearby Stony Brook Regional Sewerage Authority.
This came as part of How Cities Work, a freshman seminar that introduces
students to the infrastructure that makes cities work. Electrical engineering
professor Sigurd Wagner developed the course. "I want to use for
instruction the vast infrastructure of the campus and the knowledge of
its managers," Wagner says. "I want to open freshmen's eyes
to the breadth of the infrastructure of a city and the expertise needed
to run it."
Throughout the course, students examine how cities supply water, electricity, heat, information, and security for its inhabitants. Each lesson centers on one city service, with Princeton used as the model city. Students study the underlying scientific and engineering principles at work and then visit each facility for a firsthand view of its operations. In addition to the Stony Brook sewer plant, students in last year's class also visited Elizabethtown Water Company's plant as well as Princeton's DeNunzio swimming pool's mechanical room, chilled water plant, central control room for campus HVAC systems, cogeneration plant, and main campus telephone switching system.
Progressive
Engineer
Editor: Tom Gibson
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