sealPurdue Business and Technology Briefs

October 1999

New institute to begin research into quiet highways

WEST LAFAYETTE, Ind. – Engineers at Purdue University have formed the first center in the nation dedicated to understanding the precise physics behind highway noise, a prerequisite for reducing the nuisance.

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The numerous buffers installed between freeways and residential neighborhoods attest to the problem, says Bob Bernhard, director of the new Institute of Safe, Quiet and Durable Highways, which was dedicated Aug. 27.

"Residents rarely complain about being able to see a highway, but they often complain about highway noise," he says, noting that barriers built to wall out the road racket can cost as much as $1 million per mile.

Bernhard says most of the acoustical pollution from cars doesn't come from engine noise but from the interface of tires and road surfaces. Engineers suspect that several mechanisms are to blame, including:

• Air that is trapped and compressed between a tire's tread pattern and the road surface eventually bursts from the confining spaces, causing pops and whistles.

• Block-like shapes in the tread design that smack against the road surface like tiny hammers.

• Those tread blocks and underlying belts vibrate and radiate energy outward, producing sound much like the vibrating cones in stereo speakers.

Purdue engineers propose to attack the problem by studying both tires and road surfaces. The results will then be used to design tires and road surfaces that make less noise.

Research will include the use of lasers and sound waves to analyze noise-producing mechanisms in rotating tires. Engineers will study porous pavements that have been used in Europe to build quieter roads.

The institute is a joint project of Purdue's schools of civil and mechanical engineering in collaboration with researchers from the Pennsylvania Transportation Institute at Penn State University, where researchers will make a database of sound produced by transit buses in efforts to reduce bus-related noise pollution, he says.

The institute is funded by a $3.6 million grant from the U.S. Department of Transportation and an equal amount from other government and private sources. It will expand later to include research dealing with other sources of transportation-related noise, such as truck engines, as well as issues involving highway safety and durability, Bernhard says.

CONTACT: Bernhard, (765) 494-2141; home (765) 463-5463;

Super size is not a super deal, economists' study finds

WEST LAFAYETTE, Ind. – Consumers who buy "economy-size" packages thinking that they are saving money may be in for a rude awakening.

A Purdue University study has found that consumers are so convinced that larger sizes mean cheaper prices that they don't bother to compare the per-ounce prices. Certain products at the grocery store prey on this inattention by charging more per ounce – sometimes as much as twice as much per ounce – for the larger sizes.

Economists call this practice "surcharging." James Binkley, professor of agricultural economics at Purdue, says that surcharging happens frequently in grocery stores.

"We don't really know how many products have a surcharge," Binkley says. "It happens with flour, and I've seen it with toilet paper, canned chili, peanut butter and tomato products such as ketchup."

Binkley, together with John Bejnarowicz, a former graduate student at Purdue, studied surcharging in tuna because surveys have consistently found that it has surcharges on larger sizes. For example, two six-ounce cans of tuna are usually cheaper than one 12-ounce can.

"This isn't just a slight difference either," Binkley says. "Often the larger sizes are 20 percent more per ounce. There are even reports of times when the surcharge is a full 50 percent to 100 percent.

The study used sales information from 54 wholesale grocery regions in the United States. It compared sales volume and prices of cans of tuna, along with consumer demographics, to determine why consumers buy larger sizes even when they are more expensive.

The results indicated that many consumers who buy the large sizes have a mistaken belief that these sizes are always cheaper per ounce and don't bother to examine the prices.

The study found that people with higher incomes were more likely to fall victim to the surcharging gambit. "These people have high time demands, and they are less likely to take the time to closely examine the prices. They just grab something and go," Binkley says.

He says it's hard to find out how surcharges arise. "The grocery store retailers claim that it's the manufacturers' pricing, and I think they're probably right," he says. "But it's hard to get a straight answer on this. I've called tuna companies several times and asked about surcharging, but they almost never call me back."

CONTACTS: Binkley, (765) 494-4261;;
Bejnarowicz, (847) 267-4880;

New aviation lab lands at Purdue

WEST LAFAYETTE, Ind. – United Airlines has donated a second commercial aircraft to Purdue University's aviation technology department.

The Boeing 737-200, repainted in Boilermaker gold and black, arrived at the Purdue Airport last spring and was dedicated as a life-sized learning lab in a special ceremony in September. It joins the Boeing 727-100 that United gave to the university in 1993.

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Like the 727, the aircraft will be used as an on-the-ground laboratory for the 600 students in the three aviation-related majors offered at Purdue; aeronautical technology, aviation administration and flight technology.

"We're delighted with the gift, not only because the 737 has newer technology than the 727, but also because having two large aircraft will allow more students to work simultaneously," said Michael Kroes, head of the aviation technology department. "It will be particularly useful to aeronautical technology students while learning heavy aircraft systems, operations, maintenance and engineering."

The 737 is the most widely used transport aircraft in the world. This particular plane was delivered to United in March 1969 and retired from service last July after completing 57,582 hours of flight time.

Fred Mohr, general manager of United's Indiana Maintenance Center in Indianapolis, said the donation continues the tradition of the airline's commitment to aviation education.

"Purdue's aviation technology department is a primary source of interns and employees for United, so it makes good business sense for the company to contribute to new learning opportunities for students," he said.

Purdue, which in 1930 became the first university to establish an airport and which was the first university to offer a flight training program for college credit, is one of three universities to receive a retired 737 from United this year. In March, the company gave a 737-222 to Southern Illinois University, and on Sept. 3 a similar plane was dedicated at Lewis University in Romeoville, Ill.

Employee training reduces levels of styrene pollution

WEST LAFAYETTE, Ind. – Engineers at Purdue University have shown in preliminary findings that pollution associated with styrene could be reduced by more than 40 percent by instructing workers on the best techniques for applying styrene-based materials.

The research at Purdue is part of an effort to help companies comply with federal environmental guidelines for emissions of styrene, a chemical compound used to make fiber-reinforced plastics for products such as recreational vehicles, boats and shower stalls.

The U.S. Environmental Protection Agency has changed how it estimates the annual quantity of styrene that a company emits, in effect doubling its estimates of emission levels. That could make it more difficult to meet federal and state air pollution requirements, says James R. Noonan, assistant director for education and technical assistance of the Indiana Clean Manufacturing Technology and Safe Materials Institute at Purdue.

The emission statistics for 1998 will be the first to reflect the higher levels. They will be released by state, federal and industry sources over the next year.

The employee-training program was conceived by a national organization called the Composites Fabricators Association, but its pollution-reduction benefits had not been documented until the Purdue engineers conducted tests using specialized equipment built at the institute.

Workers who use spray guns to coat molds with a liquid that contains styrene are taught techniques to cut down on styrene emissions. For example, they are schooled in different ways of setting up their work to minimize the amount of spraying needed for the job. They also learn new approaches to spraying in which the individual droplets of styrene are larger, ultimately reducing the overall quantity exposed to the air, and, consequently, decreasing emissions, says Jean Hall, a Purdue engineer involved in the work.

The Purdue institute has been gathering data and conducting tests since March to analyze just how effective the training program is. The preliminary data showed that using these techniques reduced styrene emissions by 21.7 percent, and reduced the overall quantity of styrene needed to do the job by 19 percent.

The combined effect of both reductions is a 42.4 percent decrease in emissions, Noonan says.

Purdue engineers will conduct further tests at the institute's Coating Applications Research Laboratory before issuing a final report.

Styrene, a suspected carcinogen, has been used for decades to manufacture everything from drinking cups to lightweight auto and boat parts. It has been classified by EPA as a volatile organic compound, meaning it tends to combine with other chemicals to form entirely new compounds. One result is the creation of ozone, a molecule that contains three atoms of oxygen instead of the environmentally friendly two-atom form of the gas. Ozone is a pollutant that is unhealthy to breathe and is thought to be harmful to vegetation and wildlife.

It should not be confused with naturally occurring atmospheric ozone, contained in the stratosphere, which acts as a filter for harmful ultraviolet radiation.

CONTACT: Noonan. (765) 463-4749,

Compiled by Frank Koontz, (765) 494-2080,

Purdue News Service: (765) 494-2096;


Jacob Klos, left, a Purdue graduate student in mechanical engineering, and Bob Bernhard, an engineering professor and director of the university's Institute of Safe, Quiet and Durable Highways, use a laser to study how noise is generated by a smooth tire on a textured surface. The tire, painted white to better reflect laser light, is rotated on a motor-driven roller. The laser measures vibration, and the data are relayed to a "signal analyzer" for interpretation. (Purdue News Service Photo by David Umberger)

A publication-quality, downloadable photo is available at the News Service Web site and at the ftp site. Photo ID: Bernhard.roads

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Purdue students line up for a good look at the aviation technology department's newest laboratory, a retired Boeing 737 aircraft donated by United Airlines. The plane arrived in West Lafayette on May 8 and was dedicated today (Friday, Sept. 10) for educational use. (Purdue News Service Photo by David Umberger)

A publication-quality, downloadable photo is available at the News Service Web site and at the ftp site. Photo ID: Kroes.newplane

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