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News Service

News Service:

Annette Hacker, director, (515) 294-3720

Office: (515) 294-4777

Research news from Iowa State

March 2004

AMES LABORATORY

Think thin

Researchers at the U. S. Department of Energy's Ames Laboratory and Iowa State University have found an unusual growth mode -- never before observed -- that may prove critical in developing atomic structures of unusual uniformity for nanotechnology applications.

The new frontier of nanotechnology deals with thin films, fine particles or chemical syntheses that can be measured in nanometers, or one-billionth of a meter. Such a minute scale means that the thinner you can make the film, the smaller you can make components such as switches, lasing materials and semiconductors. And packing more into a computer chip helps it to run faster. The findings at the Ames Laboratory may allow the further miniaturization of silicon-based electronic devices, a major undertaking in light of the silicon industry's huge role in technological innovation and production.

Typically, when materials "grow" on a silicon film, the deposited metal atoms stack up in "islands" of widely varying height. Using scanning tunneling microscopy and quantitative electron diffraction, Ames Lab researchers, led by physicist Michael C. Tringides, have discovered that lead (Pb) atoms seem to be "intelligent" and make only one height choice, depending on the temperature (185 Kelvin to 220 Kelvin). This ability to achieve exact control of layer thickness and atomic uniformity of thin films and nanostructures, according to Tringides, is the "Holy Grail of nanotechnology."

The fundamental research effort, supported by the Department of Energy s Office of Basic Energy Sciences, is providing significant information about the microscopic processes that control the growth of custom-made materials.

For more information, contact Tringides at (515) 294-6439, or Saren Johnston, Ames Laboratory Public Affairs, at (515) 294-3474. An image of Pb/Si(111) islands can be found at http://www.ameslab.gov/news/release/2004rel/leadsiliconimage.htm.)

COLLEGE OF EDUCATION

A measure of success

An Iowa State University faculty member is creating monitoring tools that will measure the learning progress for students with disabilities.

Anne Foegen, ISU associate professor of curriculum and instruction, is working with Midwestern schools to create a system of assessment tools that will provide educators with invaluable information about students' progress in mathematics. The tools are designed to help teachers make more informed instructional decisions and increase students' achievements in mathematics.

"The goal of the research is to help students with disabilities have better access to the challenging curriculum that their peers study," Foegen said. "The research will cut across disability types, content areas and grade levels. The result will be a seamless transition in monitoring progress across grade levels for individual district and school programs. There is little research of this type in mathematics at the middle-school level and even less at the high-school level. In practice, the research will help teachers more efficiently identify students who are not experiencing success, track the effects of efforts to assist these students, and improve decision making regarding the effectiveness of instruction."

The U.S. Department of Education's Office of Special Education Programs has awarded Foegen $375,000 for five years to support her research.

In addition, Foegen is working with central Iowa teachers on a different project to study the alignment of algebra curriculum, instruction and assessment for students with and without disabilities. Foegen's projects also will develop and test algebra proficiency assessment tools for measuring the achievement of students. According to the ISU faculty member, mathematics achievement for these students is often two grade levels or more below that of non-disabled students. This disparity can limit college or career choices for students with disabilities.

Foegen will study the algebra curricula, teaching strategies and current evaluation tools used for algebra I students in the Ballard, South Tama and Fort Dodge community school districts. She also will create new tools to monitor the learning progress of all students. "The assessment tools could serve as an early warning system for teachers, to help them identify any students who are struggling early in the semester," Foegen said. "The sooner teachers can identify a problem, the sooner they can initiate instruction to overcome the problem and get the student back on track," she said.

This research project also is funded by the U.S. Department of Education's Office of Special Education. Foegen will receive $473,400 for three years.

For more information on either of her research projects, contact Foegen at (515) 294-8373; Cathy Curtis, College of Education, (515) 294-8175; or Kevin Brown, ISU News Service, (515) 294-8986.

When class affects the class

According to one Iowa State University professor, contemporary educational research is remiss when it fails to address how lifestyle hardships affect learning in poor children.

Sarah Lubienski, an ISU assistant professor of curriculum and instruction, speaks from experience. Raised in a lower socio-economic family, she understands the challenges of families facing physical abuse, child neglect and other social issues that impact learning, either subtly or directly.

Yet Lubienski, an assistant professor of curriculum and instruction, contends that much of current educational research prefers to ignore how the social struggles of some students may directly affect their classroom performances.

"Researchers since the 1970s have moved away from viewing disadvantaged families as 'deficient' and instead have emphasized strictly positive aspects of cultural diversity," she said. "Despite its good intentions, the movement toward celebrating diversity has diverted attention from socio-economic inequities. Researchers have made it taboo to study negative aspects of life among the lower classes. By avoiding the difficult issues that marginalized parents, students and their teachers face every day, educational research is becoming less useful and credible."

Lubienski's comments appear in a journal article she published in the recent Educational Researcher. She stresses that the inclusion of challenges faced by lower socio-economic households doesn't create "excuses" for teachers, but ultimately can help more effectively educate all students by making teachers aware of the special strengths and needs of disadvantaged children.

"Talking in-depth about class-related disparities involves acknowledging problems, such as malnutrition, parental substance abuse, domestic violence and childhood trauma," Lubienski said. "Though these problems occur in all social classes, they occur more often among families with low socio-economic status."

For more information, contact Lubienski at (515) 294-3351; Cathy Curtis, College of Education, (515) 294-8175; or Kevin Brown, News Service, (515) 294-8986.

COLLEGE OF ENGINEERING

You can run, but you can't hide

Tom Daniels, assistant professor of electrical and computer engineering, and two colleagues have received a $1.2 million, 30-month contract from Advanced Research and Development Activity (ARDA) to develop software that will serve to "fingerprint" and track down computer criminals. The contract, the largest awarded to a research effort in this area at Iowa State, supports Daniels' work, as well as that of department team members Julie Dickerson and Yong Guan.

"Computer crime has skyrocketed," says Daniels, "and the ability to secure systems hasn't kept up. The motives of the perpetrators are difficult to guess. Sometimes they are politically or socially driven. Sometimes people do it just because they can. But there is nothing benign about it. The threat is real. It's costing us millions."

The "whodunit" software that Daniels and his team are developing will identify just the right amount of clues and red flags to track down perpetrators. Existing programs have fallen short, he says, because either too many or too few clues are identified. "If the program is too simple, sophisticated attackers can get around it. And if a program is too broad, there are too many false alarms and wrong guesses."

The team's work will be valuable to a wide range of E-traders. "Let's say you try to log on to e-Trade, to trade stock. But a denial of service is being launched and you can't log on. The market changes and you lose thousands of dollars. Who do you sue? Who does the federal trade commission sue? Who does e-Trade go after?"

"We will develop techniques that postmark traffic at every point," Daniels says. "Computer traffic needs the equivalent of a Federal Express tracking number, not a post card with a wrong address."

For more information on Daniels' research, contact him at (515) 294-8375, or Karol Crosbie, Engineering Communications and Marketing, at (515) 294-4881.

From grass to gas?

While the automobile industry races to put fuel-cell vehicles on the market, Iowa State University researchers are working to produce hydrogen-rich gas from a native Iowa prairie grass to power the new vehicles. The research team, directed by Robert C. Brown, the Bergles Professor in Thermal Science in mechanical engineering and professor of chemical engineering, has developed a process for converting switchgrass into hydrogen.

Biomass is injected into a high-temperature, oxygen-starved reactor, known as an indirectly heated gasifier. There it is converted into a flammable gas. "Energy in the biomass drives chemical reactions that release hydrogen from steam that has been added to the gasifier," explains Brown. While conventional gasification produces a fuel gas with only 8 percent hydrogen, the Iowa State researchers have increased the yield to 60 percent with a goal of reaching 90 to 95 percent hydrogen in this final year of a three-year grant. Vehicles powered by fuel cells require this high level of hydrogen concentration.

Funded through a $1.23 million grant from the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy and with support from the Iowa Energy Center, the project bodes well for Iowa's bioeconomy. "Nature has determined that switchgrass is the most suitable plant to grow in this part of the country," Brown explains. "But, until now, there hasn't been a market for it."

For more information, contact Brown at (515) 294-7934, or Mary Jo Glanville, Engineering Communications and Marketing, (515) 294-8787.

Engineer lauded for lights-out research

The research of an Iowa State University faculty member has been included in MIT's recent list of "10 Emerging Technologies That Will Change The World."

Vijay Vittal, Harpole Professor of Electrical and Computer Engineering, was cited in the MIT Technology Review article for his work in the simulation of large-scale power systems. As aging and stressed electrical power systems break down and precipitate massive blackouts or brownouts, Vittal and colleagues are researching and designing methods of warding off these power disturbances and making the systems more reliable.

Vittal, a native of India, focuses his research on several electrical and power system issues, including power system dynamics, the dynamic security assessment of power systems, power system operation and control, and application of robust control techniques to power systems. He is an internationally recognized leader in his field, and he has authored two textbooks on power system analysis.

Vittal currently directs the Electric Power Research Center at Iowa State. He has received many honors and awards for his work, and recently was inducted into the National Academy of Engineering. For more information, contact Vittal at (515) 294-8963, or Debra Gibson, News Service, (515) 294-4917.

COLLEGE OF LIBERAL ARTS AND SCIENCES

It takes a village

It plays out like a Spielberg epic: Bands of soldiers are driven from their native lands by Communist forces. Driven from one hiding place to another, they eventually flee into hill country, where they forage for food and in time, grow their own corn and potatoes. Today, they are successful fruit and nut farmers and dominate the marketplace in their corner of the world.

Indeed, when Shu-min Huang was a teen in his native Taiwan, he read a novel depicting these very events. It wasn't until years later that that the social scientist began studying this group of Nationalist Chinese soldiers and their spectacular recovery in Thailand.

Huang, professor and chair of anthropology, is in the midst of a two-year study, funded by the Wenner-Gren Foundation, to examine these refugee soldiers' communities and their rapid economic growth. He's investigating how these two groups of 1,000 refugees each expanded their hillside holdings from two to 40 villages, now populated by 300,000 residents.

"These refugees developed social networks that proved useful in the globalization process," Huang said. "Very often, you will see that these people will use their connections with other ethnic Chinese and other Chinese refugees to help raise capital and become commercially viable."

To learn more about Huang's discoveries, contact him at (515) 294-7348, David Gieseke, College of Liberal Arts and Sciences, (515) 294-7742 or Kevin Brown, News Service, (515) 294-8986.

The shell game

ISU researcher Donna Surge talks trash when discussing how to reconstruct the past climate in Florida. That's because the important component to her research exists in ancient trash heaps, called "middens."

Surge, assistant professor of geological and atmospheric sciences, and her colleagues in Florida hope to develop a new method to reconstruct Southwest Florida's past climate using shells of the native Florida clam, the southern quahog.

"Climate has played a major role in human history, which is well documented in Europe," Surge said. "We're trying to get a handle on past climates at low latitudes."

The Florida clamshells were discarded over centuries prior to Spanish occupation into trash heaps by the Calusa Indians. The shells contain chemical signatures of past water data, which Surge hopes to translate into paleoclimate information.

The shells also have growth bands (like a tree ring), which will allow Surge to decipher annual and seasonal cycles to help determine temperature, precipitation patterns and how salty the water was.

For more information, contact Surge at (515) 294-7584, or Debra Gibson, News Service, at (515) 294-4917.

Quote

"Computer crime has skyrocketed and the ability to secure systems hasn't kept up. The motives of the perpetrators are difficult to guess. Sometimes they are politically or socially driven. Sometimes people do it just because they can. But there is nothing benign about it. The threat is real. It's costing us millions."

-- Tom Daniels, assistant professor of electrical and computer engineering (Story.)

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