News & Ideas is a guide to research in science, technology, management, architecture, and humanities and social sciences at Rensselaer. For details or photos, contact Marketing and Media Relations, Rensselaer Polytechnic Institute, Troy, NY 12180, (518) 276-6532, or e-mail us at nasons@rpi.edu.

LEAD POLLUTION
More Garbage than Gasoline

ELECTRONICS MANUFACTURING
Virtual Designer Environment

BIOMATERIALS
Durable Hip Replacements

COMPUTER NETWORKS
In-time Predictions of Failures

APOLLO ANNIVERSARY
Celebrating Space Exploration

LEAD POLLUTION:
More Garbage than Gasoline

Despite popular belief, leaded gasoline wasn't the main contributor to high atmospheric lead levels in New York City during the 20th century, says Richard Bopp, associate professor of earth and environmental sciences at Rensselaer.
Lead pollution has become a major health concern because of its link to neurological damage. But most of the lead that entered the NYC atmosphere came from incineration of municipal solid waste, not from the use of leaded gasoline, says Bopp.
The study, which was published in the March issue of Environmental Science and Technology, is the work of researchers at Rensselaer, Columbia University, and the New York State Department of Environmental Conservation. It was funded through a Superfund Basic Research Grant to Mount Sinai Medical Center.
Analysis and dating of sediment layers at the bottom of Central Park Lake show maximum levels of lead deposition in the 1930s. This was well before the peak use of leaded gasoline, but coincident with a peak in municipal solid-waste incineration, says Bopp.
The presence of tin, zinc, and other heavy metals supports the conclusion that the atmospheric lead came from the incineration of municipal waste that contained such things as paint and solder.
The findings are vitally important in assessing the impact of unregulated incineration of solid waste in many countries of the world, Bopp says.
Lead deposition in NYC and blood lead levels have decreased significantly since about 1970, matching a decline both in municipal solid-waste incineration and in the use of leaded gasoline.

Contact: Richard Bopp 518-276-3075, boppr@rpi.edu

ELECTRONICS MANUFACTURING
Virtual Designer Environment

The Electronics Agile Manufacturing Research Institute (EAMRI) at Rensselaer is patenting a Virtual Designer Environment that has demonstrated its ability to cut the design and manufacturing cycle from months to days for printed circuit board assemblies.
At the same time, the system enhances quality and reliability, according to Robert Graves, EAMRI director.
The EAMRI was established at Rensselaer in 1994 by the National Science Foundation (NSF) to find solutions to problems created by a shift in the electronics industry to more distributed design and manufacturing. Where design, manufacture, and testing of printed circuit boards once took place in the homogeneous environment of a large company, these processes now are more likely to occur in widely distributed settings.
A major company may design the electronics for a particular system, and then buy the circuit boards from one manufacturer and the components from another, relying on a third to assemble the board. Such outsourcing can improve quality and cut costs, as companies compete to win contracts in their area of expertise. But the distributed environment presents major challenges for information systems.
In response, the EAMRI created the Virtual Designer Environment, which bases critical design and manufacturing decisions on agile intelligent autonomous agents that gather up-to-date information from locations in the distributed network. The system integrates disparate databases on different computer systems, creating a model that supports the fastest possible throughput cycle at the lowest cost for printed circuit board assemblies.
In demonstrations in 1997 and 1998, the system produced an optimal design for an actual Pitney Bowes controller board by accessing via the network component supplier databases from Pitney Bowes, Vermont Circuits, and Lucent Technologies, cost profile and design rules databases from Hughes Missile Systems, and board fabrication and assembly cost databases from Lucent Technologies. Now the Virtual Design Environment is being patented.

Contact: Robert Graves (518) 276-6955, graver@rpi.edu

BIOMATERIALS
Durable Hip Replacements

Changes in a sterilizing process for the materials used in hip replacement surgery could substantially increase the life expectancy of these implants, according to a Rensselaer researcher.
Thierry Blanchet, associate professor of mechanical engineering, will report in April to the annual meeting of the Society for Biomaterials that his preliminary results show that tying up free radicals in the polyethylene can reduce wear by a factor of three. He has now received funding from the Whitaker Foundation to confirm the preliminary findings and to explore new approaches.
In the half-million total hip replacements performed worldwide each year, surgeons ream out the hipbone socket and cement in a polyethylene cup. They also insert a metal shaft in the femur. A ball on the end of the shaft rides in the cup.
Life expectancy of the surgery is about 15 years. One major cause of failures, explains Blanchet, is a "cascading chain of events" that begins when the polyethylene cup is irradiated during manufacture to sterilize it.
The radiation strips hydrogen from the hydrocarbon chains, creating free radicals that react with oxygen from the surrounding environment. These aging reactions cut the polymer chains, and the polymer abrades, releasing debris. The bone reacts, and the implant loosens.
Blanchet and doctoral student Brian Burroughs showed that during radiation, or directly after, they could force the free radicals to react with hydrogen, ethylene gas, or even with each other, tying them up so they couldn't react later with oxygen.
As part of the research, Burroughs served an internship with the orthopedics biomechanics lab at Massachusetts General Hospital last summer, and he continues to collaborate with this group. Blanchet also has been consulting with Dr. Dana Mears, chief of orthopedic surgery, at Albany Medical Center.

Contact: Thierry Blanchet (518) 276-8697, blanct@rpi.edu

If you see that a truck is about to pull in front of you in time to step on your brakes, it is an annoyance. If you get the information seconds later, it can be a disaster.
Chuanyi Ji, associate professor of electrical, computer, and systems engineering at Rensselaer, builds "intelligent agents," computerized systems that may one day warn of impending failures on communications networks. With sufficient warning, a network could correct itself or a human manager could intercede.
Ji is working to move from a reactive response - looking for a problem once it occurs - to a proactive one in which problems may be anticipated and avoided.
"We also want to automate the process," she says. "At present, it takes a lot of human intervention to find and fix a problem."
Already, she and her students have tested an agent on a router on a Local Area Network (LAN) and found that it successfully predicted some faults before they occurred. In one case, the agent predicted a failure, caused by a buildup of abnormally high traffic, minutes in advance.
This initial test was completed on the LAN used by the computer science department at Rensselaer and on a corporate network. But Ji, whose work is funded by the National Science Foundation and the Defense Advanced Project Research Agency, is also looking beyond such current Internet systems to next-generation networks that will carry far more data on complex combinations of wired and wireless systems.

Contact: Chuanyi Ji (518) 276-6534, chuanyi@ecse.rpi.edu

APOLLO ANNIVERSARY
Celebrating Space Exploration

As part of its 175th anniversary observance, Rensselaer Polytechnic Institute is inviting the entire community to Space Week - a gigantic celebration observing the 30th anniversary of the Apollo Moon Landing, the 40th anniversary of NASA, and the Institute's own strong connections to the space program.
From April 5 to 11, Rensselaer students, faculty, staff, and alumni as well as residents from throughout the region are invited to learn more about space exploration. The focus will be on education with speakers, technical experts, and visiting astronauts and cosmonauts offering views of NASA's past and future. The Houston Field House, home of Rensselaer's Division 1 hockey team, will be transformed into a Space Week Museum, featuring NASA, corporate, and Rensselaer exhibits.
More than 3,0000 schoolchildren, teachers, and chaperones have signed up for visits to the museum during Space Week. Local science teachers have gathered and written curriculum to focus on space exploration. Astronauts and cosmonauts will guide many of the school groups through the museum.
NASA is furnishing displays for the museum, including a moon rock, a Skylab space suit, and models of Saturn 5 and Mercury Redstone rockets. The Low family is loaning items for an exhibit on George Low, manager of the Apollo space program and Rensselaer's 14th president. Major corporate exhibits are coming from Lockheed Martin, United Technologies, and Boeing.
Keynote speakers will include Dan Goldin (April 5), NASA administrator; Hans Mark (April 7), director of defense research and engineering at the Pentagon and former deputy director of NASA, with recollections of George Low; Arthur Johnson (April 8), president and COO of Lockheed Martin Information & Services sector; and Lawrence Krauss (April 9), chairman, Department of Physics, Case Western Reserve, and author of The Physics of Star Trek.
In evening presentations, John Young, astronaut and associate director (technical), NASA, will talk on space today and tomorrow, and Russian Cosmonauts Evgenij Khrunov and Aleksey Yeliseyev will discuss the Russian space program. Grace Corrigan will speak April 9 about her daughter, Christa McCauliffe, and the Challenger flight. The committee also is arranging a series of more technical speeches for luncheon seminars.