The Earth’s natural cycles and the built environment impact and are impacted by mankind. As researchers in the College of Engineering study these environments … from the atomic to the planetary scale … they develop unique perspectives of these systems and how they work together. Researchers observe, measure, and analyze air, water, soil, and rock formations to make recommendations on how best to preserve the environment. They further use their knowledge to design and monitor waste disposal sites, safeguard water supplies, reclaim contaminated soil, and help develop building codes for stronger, safer structures. They also study the composition and structure of the physical aspects of the Earth in order to make predictions about its future.
Carl Sandburg wrote, “By day the skyscraper looms in the smoke and sun and has a soul.” While a skyscraper’s soul may be in question, skyscrapers definitely move or are buffeted by winds and other loads in the city. Since 2001, professors Ahsan Kareem and Tracy Kijewski-Correa have been active in developing sensing and virtual data acquisition technologies and cyber infrastructure to enable full-scale, in-situ observations of structures in their natural environments. What it amounts to is recording the “health” of a structure in real-time as a building reacts to various loads acting upon it.
These faculty have been executing the first full-scale systematic validation of the performance of tall buildings using three signature skyscrapers in Chicago. Their efforts earned the 2008 State-of-the-Art of Civil Engineering Award from the American Society of Civil Engineers (ASCE). Their work has also been showcased in magazines such as Engineering News Record, ASCE’s Civil Engineering Magazine, and GPS World. The program has now grown to include signature structures in South Korea, Canada, and Dubai, as well as archival data collected from the infamous Boston Hancock.
Many people are asking if better materials can be designed for the safe, permanent disposal of nuclear waste? Perhaps the question that should be addressed is not “How can society safely store the dangerous radioactive waste generated by nuclear power plants?” but “Can much of the radioactive waste be recycled into useful fuel, so that storage is less of an issue?” This is one of the basic questions that faculty in the Center for Materials Science of Actinides, a national Energy Frontier Research Center, have been actively pursuing. More specifically, they are seeking ways to control the behavior of uranium and other actinides at the nano-scale to achieve greener and more efficient nuclear energy.
All matter is composed of building blocks. The structures and shapes are different depending on the intended purpose and the materials being used. Uranium, the heaviest abundant element, is the current fuel used in almost all commercial nuclear reactors, but the nuclear waste produced is environmentally troubling. Peter C. Burns, the Massman Professor of Civil Engineering and Geological Sciences and Director of the Center for Materials Science of Actinides, and a team of University researchers have been focusing their efforts on uranium-based building blocks, specifically uranyl peroxide polyoxometalates, to provide a foundation of knowledge for a future advanced nuclear energy system.
Centuries old, polyoxometalates are metal oxide clusters. They are often studied as a model for nano-structured materials and are useful as catalysts in several chemical systems. The structures that Burns’ team is creating are important because they hold promise for being able to change the behavior of uranium and other actinides used in the nuclear fuel recycling system. They could also be used to manufacture new nuclear fuels with nano-scale precision.
Actinides, such as uranium and neptunium, are ideal candidates for self-assembly into polyoxometalates. In fact, many of the clusters the Burns’ group has discovered exhibit fullerene topologies, meaning they are cage structures that feature 12 pentagons and an even number of hexagons. It is the structure of the cage and, most important, its symmetry that appears to determine the behavior of these clusters. Uranyl peroxide clusters can self-assemble in aqueous solutions. They can be maintained in the solution for several months, and they readily crystalize into extended structures that permit detailed structure characterization. Control of uranium behavior in water by cluster formation may be used to significantly reduce the amount of waste that will actually need to be stored, i.e., a greener fuel cycle that produces more energy without a proportional increase in waste production.
Sigmon, Gintry Versus Minimal Pentagonal Adjacencies in Uranium-based Polyoxometalate Fullerene Topologies” Angewandte Chemie International Edition, 2009, 48, 2737-2740ger E.; Unruh, Daniel K.; Ling, Jie; Weaver, Brittany; Ward, Matthew; Pressprich, Laura; Simonetti, Antonio; and Burns, Peter C., “Symme.
Sigmon, Ginger; Ling, Jie; Unruh, Daniel K.; Moore-Shay, Laura; Ward, Matthew; Weaver, Brittany; and Burns, Peter C., “Uranyl-Peroxide Interactions Favor Nanocluster Self-assembly” Journal of the American Chemical Society, 2009, 131 (46), 16648-16649.
Soderholm, L.; Almond, Philip M.; Skanthakumar, S.; Wilson, Richard E.; and Burns, Peter C., “The Structure of the Plutonium Oxide Nanocluster [Pu38O56Cl54(H2O)8]14-” Angewandte Chemie International Edition, 2008, 47, 298-302.
Forbes, Tori Z.; McAlpin, J. Gregory; Murphy, Rachel; and Burns, Peter C., “Metal-oxygen Isopolyhedra Assembled into Fullerene Topologies” Angewandte Chemie International Edition, 2008, 47, 2824-2827.