Powe Award supports research to reduce vehicle emissions, create biofuel

Oak Ridge Associated Universities (ORAU) has selected Virginia Tech researchers who are working on automotive energy and environmental issues as two of only 25 recipients to receive the Ralph E. Powe Junior Faculty Enhancement Award.

Montasir Abbas, assistant professor of civil and environmental engineering in the College of Engineering, has developed and implemented successful traffic signal optimization programs to reduce delay and vehicle stops. The award will now allow him to create models to enhance these programs so even more efficient traffic signal timing will minimize vehicle emissions.

Y. H. Percival Zhang, assistant professor of biological systems engineering in the College of Agriculture and Life Sciences, has already earned patents for improved ethanol production processes. This award supports his work to understand and make the best use of the enzymes that work together in the hydrolysis of cellulose -- that is, to breakdown tough plant material into soluble compounds that are ultimately converted into biofuel and other products.

The Powe awards provides $5,000 from ORAU matched by the university to faculty members in their first two years of their tenure track as an investment in promising achievements in an important area. John C. Nemeth, ORAU vice president of partnership development, told the recipients that the award recognizes the quality and promise of their research.

The competition permits only two applications from each of ORAU's 115 university members. "This is the second year in a row that both our faculty members have been selected," said Jim Blair, associate vice president for research at Virginia Tech. "We are proud of this achievement."

Red light, green light

Traffic signals are intended to keep traffic moving and increase safety. Inefficient traffic signals cause delay, increase fuel consumption, and increase pollution. Many signal optimization programs address delay and stops, but vehicle emissions has received little emphasis. "Most signal optimization programs lack the ability to optimize multiple objectives," Abbas said.

But he has already developed signal optimization software based on multiple objectives, which has been successfully implemented in Texas, where he was an engineer with the Texas Transportation Institute. That system provides simultaneous reduction of delay and vehicle stops and allows traffic engineers to make informed and optimal decisions when designing their traffic signals.

Meanwhile, in the 1980s and 1990s, Oak Ridge National Laboratory (ORNL) researchers (Brian West, Ralph McGill, and others) developed data-based look-up tables for light-duty vehicle emissions as a function of vehicle speed and acceleration. Abbas' research will expand these look-up tables into models suitable for multi-objective optimization. He will work with John Storey at the ORNL Fuels, Engines, and Emissions Research Center to acquire new emission data, identify research priorities, develop an emission model suitable for optimization, and integrate it with the software he had developed in Texas.

"The goal is a signal timing operation plans that minimize emissions as well as other signal system objective functions," Abbas said. "In addition, the research will identify and guide needed data updates."

Abbas brings the resources of Virginia Tech's Via Department of Civil and Environmental Engineering, one of the largest programs in the United States. And he is in the process of developing an advanced signal system control lab, which will house state of the art traffic control equipment and simulation/optimization software.

Abbas received his bachelor’s degree from the University of Khartoum (Sudan); a master’s degree from the University of Nebraska-Lincoln; and his Ph.D. from Purdue University. He joined the faculty at Virginia Tech in 2005. His research interests are real-time traffic control, traffic flow theory, transportation modeling and safety, artificial intelligence, and systems optimization. He teaches traffic engineering and advanced signal system control.

Learn more about Abbas' work here.

Biofuel processing made easy

Cellulose – the primary component of plant cell wall material -- is the most abundant renewable resource. "Production of chemicals and energy from renewable cellulosic materials, such as agricultural waste and switchgrass, is vital to sustainable development because it reduces reliance on fossil fuels, decreases emission of greenhouse gases, and benefits national interests and security," Zhang said. "Cellulosic ethanol production involves three sequential steps: pretreatment/fractionation of lignocellulose -- the plant material that includes cellulose, enzymatic cellulose hydrolysis, and ethanol fermentation. However, there is insufficient information on the characteristics of cellulose after pretreatment and how these characteristics impact cellulase enzyme activities."

Different kinds of cellulase enzymes work together to digest cellulose. These processes are abundant in nature, such as when a fungus softens and digests a fallen tree. Zhang investigates hydrolysis of three types of cellulases that are produced by a fungi, Trichoderma reesei, which was discovered when it quickly degraded the cotton uniforms of marines fighting in the Pacific during the World War II. Zhang uses these enzymes to degrade cellulose in water, called de-polymerization, resulting in soluble sugars that can be converted to ethanol by wine yeasts.

"But the unidentified characteristics of heterogeneous cellulose, the complicated interaction between solid cellulose and soluble cellulase components, and the synergic/competitive relationship among various cellulase components limit the understanding of the de-polymerization process, one of the most important biological processes in nature, and also lag the development of lignocellulose pretreatment and cellulase improvement," Zhang said.

His new research, in collaboration with Mike Himmel at the National Renewable Energy Laboratory and Jonathan Mielenz at ORNL, Zhang will develop a new nano-scale tool to determine cellulose accessibility to the digesting enzymes and measure the fraction and concentration of the enzymes on the cellulose surface. The research will go on to quantitatively determine substrate characteristics and their impacts on the activities of the enzymes. "It will foster research on improvements in cellulase activity and biomass pretreatment to make bioethanol processes more efficient and economical," Zhang said.

Zhang received his undergraduate degree and his master of science degree in biochemical engineering at the East China University of Science and Technology in Shanghai, and his Ph.D. in biochemical and chemical engineering from the Thayer School of Engineering at Dartmouth College, where he was also a post-doctoral associate and a research scientist. He joined the Virginia Tech faculty in 2005. His research interests are bioenergy and biobased products, including production of ethanol and other chemicals, biocatalysis and protein engineering, environmental biotechnology, and bionanotechnology. He has established a basic molecular biology and bioprocess laboratory at Virginia Tech. He will teach thermodynamics in Fall 2006.

Learn more about Zhang's work here.