Moriah Bischann Wins SURF Speaking Competition
Material science undergraduate student Moriah Bischann, mentored by aerospace postdoctoral scholar, Dr. Owen Kingstedt, is the winner of the Doris S. Perpall Summer Undergraduate Research Fellowships (SURF) Speaking Competition. She was recognized as the best speakers-out of the 200 students who presented their SURF research. Her summer research focused on exploring the next generation of structural materials. During her ten week SURF project she studied the effects of alloying and processing on the dynamic behavior of magnesium (Mg). This work was done to address the larger question of whether Mg is a useful material for the automotive, aerospace, energy, and defense industries where a material is needed that has low density, but also the strength to withstand high impact forces.
Atomic Fractals in Metallic Glasses
Julia R. Greer, Professor of Materials Science and Mechanics, and colleagues including graduate student David Chen have shown that metallic glasses has an atomic-level structure although it differs from the periodic lattices that characterize crystalline metals. "Our group has solved this paradox by showing that atoms are only arranged fractally up to a certain scale," Greer says. "Larger than that scale, clusters of atoms are packed randomly and tightly, making a fully dense material, just like a regular metal. So we can have something that is both fractal and fully dense." [Caltech story]
Heat Transfer Sets the Noise Floor for Ultrasensitive Electronics
Austin Minnich, Assistant Professor of Mechanical Engineering and Applied Physics, and colleagues have identified a source of electronic noise that could affect the functioning of instruments operating at very low temperatures, such as devices used in radio telescopes and advanced physics experiments. The team's findings also suggest that it may be possible to develop engineering strategies to make phonon heat transfer more efficient at low temperatures. For example, one possibility might be to change the design of transistors so that phonon generation takes place over a broader volume. "If you can make the phonon generation more spread out, then in principle you could reduce the temperature rise that occurs," Professor Minnich says. "We don't know what the precise strategy will be yet, but now we know the direction we should be going. That's an improvement." [Caltech release]