THE CUTTING EDGE: COMPUTING / TECHNOLOGY / INNOVATION : Something for Eggheads to Cluck About

Many of life’s culinary indulgences--raw chocolate chip cookie dough, eggs fried sunny side up, hollandaise sauce, mayonnaise and fresh eggnog--have become forbidden pleasures since it was discovered that raw and undercooked eggs sometimes can carry salmonella enteritis, which causes food poisoning. While only one out of every 20,000 eggs is believed to be contaminated with salmonella, that was enough to put shell eggs on the Department of Agriculture’s hazardous food list in 1991.

But these forbidden foods may return to favor thanks to researchers at Purdue University. They have come up with a method of pasteurizing eggs in the shell. The slow, low-temperature process heats the yolk, which is where salmonella lurks, and kills the bacteria without solidifying the white. And these pasteurized eggs act exactly like their unpasteurized counterparts when used in cakes, cookies or eggnog.

Local producers of pasteurized liquid eggs are also interested in the process, because starting with already pasteurized shell eggs could extend the one-week shelf life of their product. This would allow them to ship liquid eggs nationwide in refrigeration. Several Indiana egg companies are already working with the Purdue researchers to scale up for commercial production.

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Reinventing the Wheel: Mountain bikes are the fastest-growing segment of the bicycle market, with more than 4 million sold last year alone. But hard-core mountain bikers put a lot of wear and tear on the two lightweight aluminum rims of their bicycles as they pedal over rocks, roots and stumps. But a better bicycle rim is being developed by two University of Wisconsin at Madison engineering professors working with TREK Bicycle Co. of Waterloo, Wis., one of the nation’s top mountain bike manufacturers.

The researchers are looking at materials such as titanium and stainless steel to bolster the strength of the rims. And they are exploring a design change by creating rims with a solid cross-section rather than the current hollow-box design. This could lead to more precise rim alignment and make it possible to connect spokes directly to the rim, rather than to the connectors known as ferrules. Other innovations include a laser welding technique to create stronger and cleaner welds.

Finally, Thermal Spray Technologies of Sun Prairie, Wis., will apply plasma coatings to the surfaces of completed rims to provide better stopping power for bikes slathered in water and mud. TREK anticipates a prototype rim will be ready for production in about a year.

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Better Than a Beep: Anyone who has visited an airport recently knows that security has been stepped up in the wake of the Unabomber: Metal detectors beep more frequently and more luggage is being hand searched. Researchers at Massachusetts Institute of Technology are developing a new security technique using a beam of neutrons that could help detect bombs and drugs smuggled aboard aircraft.

When a beam of fast neutrons is shone into an object such as a suitcase, the neutrons react with the nuclei of materials in the object. These reactions produce byproducts--gamma rays--that are distinctive for any given material. By analyzing these rays, researchers can identify the elemental composition of the materials inside a suitcase.

The technique can show, for example, that a certain area within an object has a very high amount of nitrogen and oxygen, which could indicate explosives. The technology, which utilizes a small particle accelerator, was originally developed for high-energy physics and the Defense Department’s Star Wars program. The work is being sponsored by the Federal Aviation Administration Technical Center in Atlantic City, N.J.

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Another Kind of Ozone Problem: The hole in the ozone layer isn’t the only reason scientists are worried about ozone these days. Following warnings from the Environmental Protection Agency about excessive use of chlorine to disinfect water comes a caution from the University of Illinois at Urbana-Champaign concerning ozone gas, which water utilities have begun using as a chlorine replacement.

Ozone is a powerful disinfectant, and it’s now being used by more than 140 water utilities and is being considered by many others. But a three-year project at the University of Colorado and the University of Illinois details how ozone combines with the bromine ion, a harmless particulate commonly found in drinking-water sources, to ultimately form bromate--which is a suspected carcinogen.

The EPA has proposed a maximum level for bromate in drinking water at 10 micrograms per liter. That level could be exceeded when ozone is used because the average bromide level in most U.S. drinking-water sources is almost 100 micrograms per liter. Unless bromate formation can be controlled, EPA mandates on it could sharply curtail ozone’s use for water sources with high levels of bromide. While the researchers believe there are some good control strategies, they warn that water utilities should move slowly before substituting ozone for chlorine.