University of Tennessee researchers among world's most highly cited scientists
Seven faculty members from the University of Tennessee, Knoxville—five from the Tickle College of Engineering and two from the College of Arts and Sciences— have been named to Clarivate's Highly Cited Researchers list for 2024. The honor is bestowed on only one in 1,000 of the world's scientists and social scientists.
"One indication of the importance and relevance of a researcher's contributions to their field is the number of times their work is cited by other researchers around the world," said Deb Crawford, UT's vice chancellor for research. "We couldn't be more proud of these faculty who, working with UT students, are generating discoveries at the very forefront of knowledge—another example of how UT research is making life and lives better."
Sheng Dai
Sheng Dai, a chemistry professor who holds a joint faculty appointment at Oak Ridge National Laboratory and serves as the section head overseeing four research groups in the Chemical Sciences Division at ORNL, has been named to the Highly Cited Researchers list nine times. His work focuses on developing advanced materials for energy-related applications, particularly in areas like ionic liquids and molten salts, advanced separation processes, high-entropy materials, electrochemical processes and sustainable carbon transformations.
Dai is currently working on creating porous liquids that can be used for separating different substances, storing energy and speeding up chemical reactions. He is also developing ways to turn plant-based carbon into graphite, which can be used for storing energy.
"Being included on the Highly Cited Researchers list is deeply meaningful to me," Dai said. "It reflects not only the impact of my work but also the incredible collaborations I've had with colleagues, postdocs and students at UT and beyond. I truly enjoy working with UT's vibrant research community and contributing to solving global challenges in energy and sustainability."
Dai was named a U.S. Department of Energy Distinguished Scientist Fellow in 2022 for pioneering advances in development of functional materials. Other honors include the Max Bredig Award for Ionic Liquids and Molten Salts, the ACS Award in Separation Science and Technology, the International Mesostructured Materials Association's IMMA Award, the Battelle Distinguished Inventor Award and seven R&D100 Awards.
Easo George
Easo George, an emeritus faculty member in materials science and engineering who retired in 2021 as UT-ORNL Governor's Chair for Advanced Alloy Theory and Development, continues his research on developing improved scientific understanding of alloy chemistry and structure. Alloys are substances made by mixing two or more metals or combining a metal with nonmetallic elements.
Recently he's been interested in the behavior of high- and medium-entropy alloys—metallic materials comprising three or more primary elements mixed in near-equal atomic proportions.
"Some of the alloys we have discovered and investigated have exceptional strength, ductility and fracture toughness, all of which increase with decreasing temperature down to approximately -250 degrees Celsius (-420 degrees Fahrenheit)," George explained. "These are the toughest materials on Earth and have the potential for structural applications in extremely cold conditions."
George and his colleagues have also started investigating refractory high-entropy alloys for applications at extremely high temperatures.
George has been honored with awards including the Humboldt Prize; the NASA Group Achievement Award, as part of the Radioisotope Thermoelectric Generator and Heater Unit Team, for contributions to the Cassini mission to Saturn; and the U.S. Department of Energy's Sustained Outstanding Research Award for Metals and Ceramics Sciences. He was selected as a TMS Fellow by the Minerals, Metals and Materials Society.
David Mandrus
David Mandrus, the Jerry and Kay Henry Professor of Materials Science and Engineering, holds a joint faculty appointment at ORNL and a courtesy faculty position in UT's Department of Physics. His primary research interest is the discovery and investigation of new quantum materials.
"Typically we grow single crystals of new materials, investigate their basic properties, and then collaborate with other scientists on in-depth and specialized studies of the materials," Mandrus said. "High-impact modern science, especially in physics, often involves teams of investigators working together."
Since 2006, Mandrus has been a fellow of the American Physical Society. He is most proud of being selected twice by the Gordon and Betty Moore Foundation as one of just a few EPiQS Materials Synthesis Investigators. (EPiQS stands for Emergent Phenomena in Quantum Systems.)
"In 1995, at the end of my postdoctoral fellowship, I asked my advisor, Zachary Fisk, for any advice he had for me. "'Always work with good people,' he said. I have always tried to take this advice to heart," Mandrus said. "The effort of the many students and postdocs who have been in my group over the years needs to be recognized. Highly cited lists like this one primarily recognize sustained scientific productivity over many years as well as working on problems that lots of people care about."
Richard Norby
Richard Norby, a research professor of ecology and evolutionary biology, is an ecosystem ecologist with over 40 years of experience investigating ecosystem responses to atmospheric and climatic change. He is particularly interested in the response of trees and forests to elevated atmospheric carbon dioxide.
Norby retired from ORNL in 2020 as a corporate research fellow, but he continues his research activities at UT and the University of Birmingham in the United Kingdom. It is through his work at the University of Birmingham that Norby participates in free-air CO2 enrichment experiments in an old oak forest in England and the Amazon rain forest in Brazil, continuing the research he led at ORNL.
"I have enjoyed conducting field research in diverse ecosystems including temperate forests, tropical forests, the arctic tundra and a boreal bog," he said. "Providing relevant field data to inform ecosystem models is an important priority."
Norby has been included on the Highly Cited Researchers list six times. He counts among his most gratifying recognitions being named a fellow of both the American Geophysical Union and the Ecological Society of America and receiving the Distinguished Career Service Award from the U.S. Department of Energy upon his retirement. He is an editor of New Phytologist and a trustee of the New Phytologist Foundation.
Stephen J. Pennycook
Stephen J. Pennycook, an adjunct professor of materials science and engineering, is also an adjoint professor of physics at Vanderbilt University. He previously served at ORNL as a corporate fellow in the Materials Science and Technology Division and leader of the Scanning Transmission Electron Microscopy Group at ORNL.
Pennycook is a world-leading microscopist and a pioneer of scanning transmission electron microscopy, which uses a finely focused beam of electrons rather than a broad beam to illuminate the sample. The image is formed by scanning point by point and detecting a signal generated by the sample.
Pennycook has developed the foundations of both theoretical and experimental modern microscopy, contributing to the development of the Z-contrast technique that led to the first images of single atoms of boron, carbon, nitrogen and oxygen. Scanning transmission electron microscopy can have many different imaging modes, meaning any signal that can be detected can be used to form an image as the beam is scanned. Those images directly show where the atoms are, and the amount of scattering reflects the atomic number Z.
"When it became possible to compensate for the aberrations of the electron lenses, the resolution improved, revolutionizing materials science by providing direct images of atoms in materials," Pennycook said. "These help scientists understand the true atomic origin of materials properties and also to develop new and better computer chips, detectors, catalysts, sensors, devices and ceramics."
Pennycook was named to the Highly Cited Researchers list in 2019, 2020 and 2021. Among his many honors are U.S. Department of Energy awards for Outstanding Achievement in Solid State Sciences and in Metallurgy and Ceramics.
Art Ragauskas
Art Ragauskas, UT-ORNL Governor's Chair for Biorefining and head of UT's Department of Chemical and Biomolecular Engineering, holds a complementary appointment in the UT Institute of Agriculture and serves in the Energy and Environmental Sciences Directorate at ORNL.
Ragauskas works at the interfaces of chemical engineering and chemistry and of chemical engineering and biology, directing his research at biorefining and the circular economy. Biorefining is the process of converting biomass into value-added chemicals, materials, energy and fuels, while the circular economy is an integrated systems approach to production and consumption that involves sharing, leasing, reusing, repairing, refurbishing and recycling existing materials and products for as long as possible.
Ragauskas' research program is directed at understanding and using innovative sustainable bioresources, including developing new and improved applications for nature's premier renewable biopolymers for biofuels, biopower and bio-based materials and chemicals. For example, Ragauskas and his team are converting renewable bioresources to marine and aviation biofuels, advancing the use of cellulose fibers for superwood, and developing bio-based biodegradable food packaging as well as nature-based water-grease repellent coatings for textiles. Recently his research team has begun to examine the upcycling of waste plastics.
Ragauskas has received many honors including a Fulbright Distinguished Chair in Alternative Energy, an American Chemical Society Award for Affordable Green Chemistry, and the Albert Nelson Marquis Lifetime Achievement Award. He has been named to the Highly Cited Researcher list five times since 2018, and he was included on Stanford University's list of the world's top 2% of most cited scientists in 2022 and 2024.
"I believe a professor can only be as successful as the students he educates, mentors and graduates," Ragauskas said. "My career objectives include recruiting, educating and developing the next generation of scientists who will be nationally and internationally recognized leaders in green chemical engineering as well as developing a nationally and internationally recognized research center for sustainable green chemical engineering of biorefining."
Jiaquiang Yan
Jiaquiang Yan, a joint faculty research professor of materials science and engineering, also serves as a senior staff scientist in the Correlated Electron Materials Group at ORNL. He focuses his research on novel materials—newly developed substances engineered through advanced scientific techniques to achieve specific functionalities like enhanced strength, conductivity or reactivity. Specifically, Yan concentrates on the design, growth and characterization of novel materials with unusual electrical, magnetic or thermal properties.
"My work involves rational synthesis of novel materials, mainly in single crystal form, and investigation of the structure-function relationships," he said. "The goal is to understand how to design new materials with desired functionalities."
He has received several ORNL awards and has been named to the Highly Cited Researchers list every year since 2019.
Provided by University of Tennessee at Knoxville