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Tunnel Reception * Monitoring Air Quality * Alternative Parking Lot * Alleviating Wood Damage * Cans for a Cause * New Circuit Board Research Center

Tunnel Reception
Pittsburgh commuter Brian Stancil noticed that his FM radio cut out when he drove through Squirrel Hill Tunnels near the city. One night, as the radio faded, he decided to do something about it. When he got home, he asked his father, Carnegie Mellon University professor of electrical and computer engineering Dan Stancil, "Don't you do something with wireless?" And what began as a young man's quest for music evolved into an interdisciplinary engineering project involving 11 students from Carnegie Mellon and three other schools.

The elder Stancil, who teaches wireless communications and conducts research aimed at improving radio frequency coverage in buildings, quickly pointed out to his son that he could expect "lots of red tape" when working on such a highway project. Undaunted, Brian, a computer science major at Virginia Tech, called the Federal Communications Commission, which explained that setting up FM radio reception inside the tunnels was permissible as long as it didn't interfere with radio reception outside the tunnels. Next, he made a number of calls to the Pennsylvania Department of Transportation (PennDOT), who "went out of their way to help," according to Dan Stancil.

After receiving the official go-ahead, the volunteers headed to the inbound side of the tunnels. They could work only from Sunday through Thursday after 11 p.m. One lane was closed, and a PennDOT truck was positioned in front of the students to protect them from traffic. They measured signal strength to see how far signals could propagate into the tunnel with various antenna arrangements.

After the data was collected, the students considered different antenna systems. Calculations proved that installing antennas on both ends of the tunnels required too much power -- 35 megawatts, enough to supply a small town. Another option was to run a cable with repeaters (devices that repeat radio signals) through the air ducts above the tunnels. PennDOT nixed that idea because if a repeater went bad, it would require maintenance. Finally, the students decided to run a wire through the ducts that would replicate the strength of the received signals. Armed with flashlights and braving gale-force air driven by giant ventilation fans, they crept through the unlit air ducts above the tunnels to complete measurements.

PennDOT approved the plan, and they installed the wire antenna, supported by PVC pipe, in the inbound and outbound sides of the tunnel. The project saved PennDOT thousands of dollars over having it done by a private company, and the new FM radio reception could prove important during an emergency.

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Monitoring Air Quality
The collapse of the World Trade Center towers in New York City on September 11 resulted in massive amounts of dust and other pollutants such as asbestos. Waste Management, Inc. became concerned about the safety of its workers at five locations in New York, including areas at Ground Zero, and wondered if they should provide employees with dust respirators or other special protective equipment. They enlisted the services of Camp Dresser & McKee (CDM), a civil and environmental engineering firm headquartered in Cambridge, Massachusetts, to conduct air monitoring to determine the concentration of air contaminants at facilities where their workers were present.

CDM performed air sampling at four transfer stations in the boroughs of New York and the work areas of two waste-hauling trucks within Ground Zero to determine levels of asbestos, dust, and silica within the breathing zone of the employees. The company placed sampling equipment on truck workers loading solid waste around the perimeter of Ground Zero, and at the transfer station, they put sampling equipment on traffic controllers and heavy equipment operators within the tipping floor areas.

Samples showed that traffic controllers were exposed to higher levels of dust and asbestos than the heavy machine operators at all the transfer stations. However, all asbestos concentrations were well below the OSHA permissible exposure limit and the NIOSH guideline limit. The dust and silica concentrations were all also below the OSHA exposure limit.

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Alternative Parking Lot
The honeycomb design of some new parking lots in eastern North Carolina is proving easier on the environment than conventional asphalt. North Carolina State University researchers William Hunt III, extension specialist in urban stormwater in the Department of Biological and Agricultural Engineering, and John Stone, professor in the Department of Civil Engineering, are investigating parking lots built of permeable pavement. This allows storm water to drain naturally through the soil rather than become runoff, which has the potential to contaminate soil and water with oil and other pollutants.

The technique involves layering materials to create a parking lot permeable to water and sturdy enough to support heavy vehicles. A geotextile fabric is spread on a base layer of gravel to keep it stable but allow water to pass through it, after which a layer of sand and a concrete or plastic lattice grid complete the pavement. The next step is to plant a spreading variety of grass such as Bermuda to add stability and texture. Such a lot costs more than conventional types to construct, but Hunt says, "The total costs could be less because permeable pavement may reduce the amount of money put into infrastructure such as ponds and storm drains."

North Carolina State civil engineering students designed a 26-space permeable parking lot for employees at the Hannibal Building in Kinston, North Carolina, and since it was installed two years ago, the research group has been observing it. So far, it has held up and performed well, with no runoff contaminating the surrounding area.

As their senior project, civil engineering students Jamey Westmoreland, Jason Houston, and Eric Taylor chose to design a similar parking lot at Wilmington, North Carolina's Legion Stadium, which lies near Greenfield Lake nature preserve. The students proposed a combination conventional and permeable lot that would enable researchers to compare the two types of pavement. Half the lot is standard asphalt, and the other half is Grasspave2, a set of interlocking plastic rings patented by Invisible Structures, Inc. of Aurora, Colorado. The researchers hope to observe this lot for several years to study its performance, as they have with the Kinston lot.

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Alleviating Wood Damage
Stevens Institute of Technology professor Dimitri Donskoy and a company he has formed, Intelligent Sensing Technologies (IST), have developed a breakthrough non-destructive method of detecting infestation by wood-destroying insects such as termites and carpenter ants. Through Stevens' Technology Ventures Incubator (TVI) and lab facilities, Donskoy has actually developed a variety of sensing technologies, including a revolutionary acoustical landmine detection system and technology for diagnosing deterioration in urban infrastructure. TVI aids start-up high-tech businesses with funding, expertise, and facilities at the Stevens campus.

The breakthrough technology is called the Total Wood Inspection system, or TwiN, and involves a magnetic wave sensor system capable of detecting both voids in wood and movements of active insects. IST plans to fabricate a prototype that Donskoy will develop and market to a wide cross-section of homeowners and businesses. When brought to market, each unit will cost an estimated several hundred dollars. But as Donskoy states, "Wood-destroying insects cause about $3.8 billion worth of damage a year. As it becomes commercialized, this reliable detection method should help reduce that figure significantly."

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Cans for a Cause
Last October, engineering and architecture firms joined forces in one of the most imaginative ways possible to fight hunger in Boston. They participated in CANSTRUCTION, a community service project sponsored by the non-profit Society of Design Administration. Teams of engineers, architects, and contractors designed and built enormous structures made entirely of canned goods. With the competition taking place at the Museum of Science in Boston, they competed in categories such as "Best Meal," "Best Use of Labels," and "Spirit of Boston." This year's entries included a bridge, buildings, a fire truck, a rubber ducky, and a replica of the USS Constitution.

Competing firms purchased the raw materials needed to build their sculptures and built them in a ten-foot square space up to eight feet high, after which they were left on public display for a month. After the creations were dismantled, the cans were donated to the Greater Boston Food Bank. By participating in the project, the firms donated a total of 70,600 pounds of non-perishable food.

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New Circuit Board Research Center
Richmond, Virginia soon will become home to a research center for the design of leading-edge printed circuit-board technology, according to a story in Inside Business. Anaheim, California-based DDi Corporation is spearheading the Center for Advanced Printed Circuit Board Design and Manufacturing Technology, being formed in collaboration with Virginia Commonwealth University and the University of Virginia. The $3 million center is believed to be the first university-industry center for printed circuit-board design.

Printed circuit boards (PCBs) form the basic platforms used to interconnect electronics, and they're found in most electronic products, including computers, cell phones and automotive, medical, and defense devices. As high-end processors in cell phones and personal data assistants continue to get faster, the need arises for PCB technology to keep up, says Bob Klenke, associate professor of electrical engineering at VCU who helped bring the center here. "It's really been a neglected problem. Everybody has been concentrating on the integrated circuit side of the business . . . The high-speed PCB is becoming a requirement in those types of products." He adds, "These are research problems that are interesting to us, and we're always trying to make sure the research we do has industrial relevance."

DDi has 10 PCB design centers in the U.S. and four facilities that manufacture PCBs, including one in Sterling, Virginia. The company hopes to enhance the engineering and design aspect of its business with help from research engineers at VCU and UVA as well as undergraduate and graduate students who can get hands-on experience working in the PCB field.

The center will employ about a half dozen people in the first year and a dozen the second year. It could grow to more than 50 employees down the road, says Klenke.

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Progressive Engineer
Editor: Tom Gibson
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©2004 Progressive Engineer