Michigan Tech Research Magazine 2006

Slamming Through the Universe?

The Pierre Auger Observatory: Exploring Secrets of the Extreme Universe

How do you catch a glimpse of some of the fastest, rarest particles slamming through the universe? Build a really, really big window.

Scientists at the Pierre Auger (pronounced oh-ZHAY) Cosmic Ray Observatory are doing just that on the high plains of Argentina. Their goal is to unmask the mysteries of ultra-high-energy cosmic rays.

Michigan Tech's David Nitz, a professor of physics, is among the 300-plus scientists from fifteen countries participating in the project, which is managed by the Department of Energy's Fermi National Accelerator Laboratory. At Tech, he is joined in the effort by Associate Professor Brian Fick and postdoctoral research associate Johana Chirinos Diaz, along with a team of graduate students. Michigan Tech's participation in the project is funded by the US Department of Energy.

Nitz is site spokesperson for the northern hemisphere observatory, a twin of the Auger facility to be built in Colorado. He initially led design of the Auger microwave communication system, which was ultimately finalized and implemented in Argentina by scientists from the University of Leeds.

Infinitely Renewable: Imagining a World Without Waste

There's a dirty little open secret about recycling: Often as not, the more times you recycle a material, the lower the value of the final product-think twenty-pound bond, newsprint, and blown in insulation

It doesn't have to be that way, says Michigan Tech's Tom Van Dam, an associate professor of civil and environmental engineering. It especially doesn't have to be that way with the biggest products America produces: the highways, bridges, and other massive edifices that make up the nation's infrastructure.

Van Dam and his colleagues want to recycle industrial residuals-detritus, such as slag, that's the inevitable result of the production process-and use it to make the building blocks of infrastructure: first-rate asphalt, concrete, and aggregate. Industrial residuals have long been incorporated into these products, but some applications have been more successful than others.

That's because we don't know enough about industrial residuals, according to Van Dam. "Our current way of classifying residuals is inadequate," he says. "For example, every fly ash is different. It can be the best or the worst choice for an application."

If those industrial residuals could be thoroughly studied, then engineers could pick the perfect . . . 

Nanotubes: Tubular Technology!

Yoke Khin Yap dreams of sensors that could detect any known toxin and fit in a soldier's shirt pocket. Of a supercomputer the size of your credit card. Of a cable that's long, strong, and light enough to lasso the moon.

To build them, he says, you have to start small. And in his lab, Yap, an assistant professor of physics at Michigan Tech, is doing just that.

Yap and his research team are constructing nanotubes as small as a billionth of a meter across and a few hundred micrometers long. It's not as easy as it sounds. Inside a small, airtight chamber, a special laser blasts the raw material (carbon and, more recently, a mix of boron and nitrogen) and blows it through a plasma cloud. It crystallizes on a silicon substrate, atom by atom, ring upon ring, forming impossibly tiny, infinitely perfect tubes.

What these tubes may be capable of is anybody's guess. As the carbon in a No. 2 pencil is not the same as the carbon in the Hope diamond, so the properties of carbon nanotubes are vastly different from those of naturally occurring forms of the element.

"The bonding in the tubes is as strong as the bond inside a diamond," Yap said. "With this, you could make a cable five times lighter and one hundred times stronger than steel.

Of Running in Place and Resurrections: Kerfoot Chases the Red Queen Hypothesis

"Well, in our country," said Alice, still panting a little, "You'd generally get to somewhere else-if you ran very fast for a long time as we've been doing."

"A slow sort of country!" said the Queen. "Now, here, you see, it takes all the running you can do, to keep in the same place. If you want to get somewhere else, you must run at least twice as fast as that."

—Lewis Carroll, Alice in Wonderland

You don't have to go back to the Jurassic to see evolution in action. Biological sciences Professor W. Charles Kerfoot has tracked changes that have occurred since Lewis Carroll began writing Alice in Wonderland.

And unlike paleontologists, Kerfoot doesn't have to make inferences from the fossil record. He just hatches some eggs.

Don't Blame the Big Bad Wolf

In the ten years since gray wolves were introduced to Yellowstone National Park, elk numbers have dropped by over 40 percent. But don't be too quick to blame the big, bad wolf, cautions a Michigan Tech scientist. Years of drought and pressure from the elk's primary predator, the human hunter, appear to have had a far greater impact on the region's elk population.

A statistical analysis of data from the Yellowstone region shows that drought conditions and hunting pressure alone would be expected to cut in half the number of elk from 1995 to 2005. In reality, the elk population fell 44 percent, from about 17,000 to 9,500 during the same time period.

"You don't need wolves in the picture at all to explain the population drop," said John Vucetich, an assistant professor in the School of Forest Resources and Environmental Science.

Vucetich built a number of computer models using 1961-95 data on the Yellowstone elk population, before wolves were introduced. The models incorporated three variables: the region's harvest rate, snowfall, and precipitation.

Using the best of these models, he applied it to population figures from 1995 to 2004. It predicted that, given the hunting pressure and the region's climate, the elk population would drop . . .