The next generation of miniaturized satellites ('nanosats') feature dramatically reduced thrust and impulse requirements for purposes of spacecraft attitude control and maneuvering. Efforts at the University of Vermont have concentrated on developing a chemical micropropulsion system based on a rocket grade hydrogen peroxide (HTP) monopropellant fuel. The present study is a joint computational and experimental design effort at developing a new MEMS-based micro-reactor configuration for incorporation into a monopropellant micropropulsion system. Two-dimensional numerical models of the gas phase catalytic decomposition in microchannel configurations have been developed and used to obtain critical sizing requirements for the reactor design. The computational results show that the length scales necessary for complete decomposition are compatible with MEMSbased designs; however, it is also found that the results are highly sensitive to the mass diffusion characteristics within the flow at this scale. Experimentally, a micro-scale catalytic reactor has been designed and microfabricated using MEMS techniques. The reactor uses self-assembled ruthenium oxide nanorods grown on the wall surfaces as a catalyst. It is found during experimental testing that only partial decomposition of the hydrogen peroxide occurs. The combination of multiphase and thermal quenching effects in a micro-scale geometry are identified as likely obstacles to the process. © 2012 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
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Bongard's work focuses on understanding the general nature of cognition, regardless of whether it is found in humans, animals or robots. This unique approach focuses on the role that morphology and evolution plays in cognition. Addressing these questions has taken him into the fields of biology, psychology, engineering and computer science.
Danforth is an applied mathematician interested in modeling a variety of physical, biological, and social phenomenon. He has applied principles of chaos theory to improve weather forecasts as a member of the Mathematics and Climate Research Network, and developed a real-time remote sensor of global happiness using messages from Twitter: the Hedonometer. Danforth co-runs the Computational Story Lab with Peter Dodds, and helps run UVM's reading group on complexity.
Laurent studies the interaction of structure and dynamics. His research involves network theory, statistical physics and nonlinear dynamics along with their applications in epidemiology, ecology, biology, and sociology. Recent projects include comparing complex networks of different nature, the coevolution of human behavior and infectious diseases, understanding the role of forest shape in determining stability of tropical forests, as well as the impact of echo chambers in political discussions.
Hines' work broadly focuses on finding ways to make electric energy more reliable, more affordable, with less environmental impact. Particular topics of interest include understanding the mechanisms by which small problems in the power grid become large blackouts, identifying and mitigating the stresses caused by large amounts of electric vehicle charging, and quantifying the impact of high penetrations of wind/solar on electricity systems.
Bagrow's interests include: Complex Networks (community detection, social modeling and human dynamics, statistical phenomena, graph similarity and isomorphism), Statistical Physics (non-equilibrium methods, phase transitions, percolation, interacting particle systems, spin glasses), and Optimization(glassy techniques such as simulated/quantum annealing, (non-gradient) minimization of noisy objective functions).