revised
PHYSICS COLLOQUIA: FALL
2009/SPRING 2010
Series
Directors: Sean Xing and Jay Hubisz
Administrative Questions : Ms. Penny Davis
Time :
Place: 202 Physics Building
Fall 2009
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- September 3 |
Dept. Welcoming Reception |
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- September 10 |
Prof. Liviu Movileanu (Syracuse University) Single-molecule Science with A Nanopore: Inspiration from Nature |
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A nanopore may act as an amazingly versatile single-molecule probe that can be employed to reveal several important features of nucleic acids and proteins. The underlying principle of nanopore probe techniques is simple: the application of a voltage bias across an electrically insulated membrane enables the measurement of a tiny picoamp-scale transmembrane current through a single hole of nanometer size, called a nanopore. Each molecule, translocating through the nanopore, produces a distinctive current blockade, the nature of which depends on its biophysical properties as well as the molecule-nanopore interaction. Such an approach proves to be quite powerful, because single small molecules and biopolymers are examined at very high spatial and temporal resolutions. I will discuss our recent work that provided a mechanistic understanding of the forces that drive protein translocation through a nanopore. These measurements facilitate the detection and exploration of the conformational fluctuations of single molecules and the energetic requirements for their transition from one state to another. I will also describe our recent strategies for engineering new functional nanopores, in organic and silicon-based materials, with properties that are not encountered in nature. From a practical point of view, this methodology shows promise for the integration of engineered nanopores into nanofluidic devices, which would provide a new generation of research tools in nanomedicine and high-throughput devices for molecular biomedical diagnosis. |
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- September 17 |
Kamesh C. Wali Lecture in the Sciences and Humanities Syracuse Symposium Professor Janna Levin (Barnard College) |
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Professor of Physics and Astronomy at Barnard College of Columbia University Levin's scientific research concerns the early universe. Her second book, a novel, A Madman Dreams of Turing Machines (2006) won the PEN/Bingham Fellowship for Writers that honors exceptionally talented fiction debuts. She is also the author of popular science book, How the Universe Got Its Spots: Diary of a Finite Time in a Finite Space . www.jannalevin.com/ |
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- September 24 |
Prof. Eric Schiff (Syracuse University) Science and Solar Cells: Physics old and physics new |
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There is a new urgency to the long quest for sustainable energy sources to replace fossil fuels. What roles do physics and physicists play? In this talk I'll describe two examples of how physics establishes fundamental limits for solar cells. Inexpensive solar absorbers are unlikely to be single crystals, but rather amorphous and polymeric materials that can be quite disordered. Disorder leads to "Anderson localization" of electronic states; we'll show how Anderson localization ultimately determines the useful thickness of the cells, and thus the fraction of sunlight that can be absorbed. Many scientists, including the Syracuse group, are now working on new "plasmonic" approaches intended to trap light inside solar schemes. Can these escape a fundamental physical limit for "stochastic light trapping" proposed in the 1980s? |
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- October 1 |
Prof. Brian DeMarco (University of Illinois, Urbana-Champaign) Experiments with Dirty Bosons |
Plourde | |
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Ultra-cold atom gases trapped in an optical lattice are now poised to make strong contributions to resolving outstanding questions in condensed matter physics. In these experiments, atom gases are cooled to temperatures below a millionth of a degree of absolute zero and confined in a crystal of light. I will talk about how we are using this system to simulate models relevant to dirty superconductors and highlight some recent results, including the first experiments in a fine-grained disordered lattice and the observation of a disorder-induced superfluid-to-insulator transition. |
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- October 8 |
Prof. Philippe Jacquod (University of Arizona) Mesoscopic physics in presence of superconductivity: what are the new rules of the game? |
LaHaye | |
Quantum coherence significantly affects the conductance of purely metallic mesoscopic systems, and leads to a number of deviations from the standard Drude theory of transport, such as Aharonov-Bohm conductance oscillations, anomalous magnetoconductance, universal conductance fluctuations and the apparent violation of macroscopic symmetries. |
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Prof. Dennis Discher (University of Pennsylvania) Soft Matter Physics approaches to Cell & Membrane Biology |
Forstner | |
Over the last few decades, a deeper understanding of how to make and measure synthetic soft materials has developed and now provides
both 'material tools' and concepts that can be applied to biological systems. This will be illustrated with two systems. Self assembled
block copolymer membranes will be shown to mimic cell membranes, but we exploit the robustness of the polymer systems in studies of
electrostatics-based phase separation. We also mimic the compliance |
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Dr. George Crabtree (Argonne National Laboratory) Superconductivity as an Energy Carrier |
Marchetti | |
Electricity, once produced, is a versatile, pervasive and environmentally friendly energy carrier, bringing clean, abundant power for a diversity of services at the flip of a switch. Yet by 2030 the demand for electricity will grow by 50% in the US and by 100% globally, challenging the grid to provide greater capacity, reliability, power quality and efficiency, especially in the urban and suburban areas that consume most of our electricity. Superconductivity carries high current with little or no resistance or energy loss, enabling dramatic increases in capacity and significant increases in efficiency; it switches suddenly from the lossless to the resistive state at a critical value of the current, enabling smart, self-healing power control for greater reliability. The challenges facing the grid as the backbone of our energy distribution system and the solutions that superconductivity provides will be described. |
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- November 5 |
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- November 12 |
Prof. Kara Hoffman (University of Maryland) South Pole Neutrino Telescopes |
Blusk | |
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Neutrinos are unique astronomical messengers which may provide critical information in identifying sources of cosmic rays and the physics processes out of which they are born. The search for astrophysical neutrinos has given rise to a new generation of neutrino telescopes of an unprecedented scale, including the IceCube Neutrino Observatory, which is under construction at the South Pole and will be world's the first kilometer scale neutrino telescope. The construction, which commenced in January 2005, is nearing completion, with 59 of the planned 86 strings of optical modules currently installed and operating in the clear deep polar ice. Even in its partially completed state, IceCube is already the largest operating neutrino telescope, and the results of the first analyses, along with some of the final results from its predecessor, AMANDA, offer a glimpse of IceCube's potential for discovery. However, even IceCube's unparalleled cubic kilometer of instrumented volume is not large enough to measure the flux of the so called GZK neutrinos produced by the interaction of the highest energy cosmic rays with the cosmic microwave background. Plans are already underway to follow the construction of IceCube with a 100 kilometer scale observatory designed to detect the GZK neutrinos via radio frequency emissions from the Askaryan effect. |
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Prof. Erik Luijten (Northwestern) Self-assembly of rod-like polyelectrolytes: from materials to cystic fibrosis |
Bowick | |
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Electrostatic interactions play an important role in many biological problems and can lead to counterintuitive phenomena. I will highlight a number of problems in this area that we have addressed by means of computational methods. Specifically, we have used Monte Carlo and molecular dynamics simulations to better understand the self-assembly of stiff polyelectrolytes (charged polymers). Such molecules, e.g. filamentous actin, form close-packed bundles in the presence of multivalent ions or proteins. We elucidate the physical mechanism of this self-assembly process and are able to make direct comparison to experimental results obtained via small-angle x-ray scattering. I will also demonstrate how these findings pertain to fighting bacterial infections in cystic fibrosis patients. References: |
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- November 26 |
THANKSGIVING BREAK | ||
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| - December 3 | |||
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| - January 21 | |||
| - January 28 | Prof. Adam Siepel (Cornell) TBA |
Hubisz | |
| - February 4 | RESERVED | ||
| - February 11 | Prof. Liam McAllister (Cornell) TBA |
Hubisz | |
| - February 18 | |||
| - February 25 | Prof. Nigel Goldenfeld (University of Illinois, Urbana-Champaign TBA |
Bowick | |
| - March 4 | Prof. Mark Trodden (University pf Pennsylvania) TBA |
Hubisz | |
| - March 11 |
Spring Break | ||
| - March 18 | Prof. Sacha Kopp (University of Texas) TBA |
Artuso | |
| - March 25 | RESERVED | ||
| - April 1 | Prof. Miles Blencowe (Darthmouth University) TBA |
LaHaye | |
| - April 8 | Prof. Jeevak Parpia (Cornell University) TBA |
Plourde | |
| - April 15 | Prof. Michael Brenner (Harvard) TBA |
Bowick | |
| - April 22 | |||
| - April 29 | Prof. Chris Jarzynski (University of Maryland) TBA |
Marchetti | |