Advances

Advances gives a glimpse of the many significant research projects at the university. Tell us about your discoveries. E-mail: wisweek@news.wisc.edu.

Research could lead to improved laxatives
Along with the aches and pains of aging often comes constipation. Though over-the-counter fiber supplements that contain psyllium seed husks can help keep us regular, many taste unpleasant. While the supplements mixed into drinks taste gritty, those incorporated into foods tend to gel in the mouth. A recent development made by nutritional scientists could lead to a more pleasing product.

Researchers Judith Marlett and Milton Fischer identified the active agent of psyllium seed husks — the main ingredient in supplements such as Metamucil — and developed a concentrated source of fiber. Their studies show that this concentrated form is just as effective at producing regularity.

The researchers’ concentrated form, which also lowers cholesterol levels, could lead to smaller doses, perhaps someday even in the form of tablets or capsules, says Marlett. “It’s really going to be a nice product once somebody develops it.”

Prof touts “superpave” specs
Longstanding asphalt specifications may fall by the wayside in light of a new report by civil and environmental engineering professor Hussain Bahia. The report highlights several changes to national standards that will result in better-performing asphalt that is more inclusive of new and emerging materials.

The report’s main finding is that current American Association of State Highway and Transportation Officials specifications for performance graded asphalt binders underestimate the potential performance of modified asphalt binders. The resulting report proposes changes to national specifications, including six new standard testing protocols, two new machines (one is under patent application) and a new asphalt grading system to be used nationally.

“For the last five years our group has studied the best methods of evaluating asphalts modified with additives such as plastics, polymers and recycled tires,” says Bahia, principal investigator. “We have developed new methods to study storage stability, workability and resistance of asphalt to heavy traffic conditions.”

The proposed standards include criteria to account for traffic volume, traffic speed and pavement structure.

The research and report was funded by $1 million from the National Cooperative Highway Research Program.

Process yields better alloy
By adding small quantities of elements such as lead to certain materials, scientists have discovered they can make a more versatile aluminum alloy that’s stronger by weight than steel.

The alloy’s strength originates from the effect of almost countless numbers of tiny pure-aluminum particles, called nanocrystals, dispersed uniformly throughout the material’s otherwise random, or amorphous, atomic structure. A miniature internal framework, the aluminum nanocrystals act as strengtheners by blocking the paths along which the amorphous alloy traditionally deforms.

The key is to produce and control the number and location of the nanocrystals, which have diameters about 10,000 times narrower than a human hair, says John Perepezko, materials science and engineering professor who conducted the research with then-graduate students Don Allen and James Foley. The strategy also can apply to other materials. The new materials, which manufacturers also can make in bulk form, could be used in everything from golf clubs and bicycles to transformers, airplane parts or other high-performance applications.