Events at Physics |
Events During the Week of February 7th through February 14th, 2010
Monday, February 8th, 2010
- Plasma Physics (Physics/ECE/NE 922) Seminar
- Nonlinear Evolution of Resistive Tearing Mode with Sub-Alfvenic Shear Flow
- Time: 12:05 pm
- Place: 2241 Chamberlin Hall
- Speaker: Zheiwei Ma, Zhejiang University
- Plasma Theory Seminar
- An Update on Two-fluid Single-Helicity Tearing Mode Relaxation in a Cylindrical Pinch: Larger Lindquist Number and Helical Flow Visualization
- Time: 4:00 pm
- Place: 514 ERB
- Speaker: Jake King, UW-Madison, Dept of Physics/CPTC
Tuesday, February 9th, 2010
- Chaos & Complex Systems Seminar
- Elegant Chaos: Algebraically Simple Chaotic Flows
- Time: 12:05 pm
- Place: 4274 Chamberlin Hall
- Speaker: Clint Sprott, UW-Madison, Dept of Physics/Plasma
- Abstract: The quest for algebraically simple chaotic systems began fifty years ago when Ed Lorenz discovered chaos in a simple model of atmospheric convection. By now, dozens of chaotic systems, some even simpler than the celebrated Lorenz attractor, have been identifed and studied. This talk will describe a 20-year effort to find even simpler chaotic systems as summarized in a soon-to-be-published book by the same title in which 280 examples, most of which have never been previously published, are cataloged. Some new chaotic electrical circuits will also be described and demonstrated.
Ref: http://www.worldscibooks.com/chaos/7183.html
This talk is available as a PowerPoint Presentation. Wednesday, February 10th, 2010
- No events scheduled
Thursday, February 11th, 2010
- R. G. Herb Condensed Matter Seminar
- Biomimetic Color Detection Using Chromophore-Nanotube Hybrid Devices
- Time: 10:00 am
- Place: 5310 Chamberlin
- Speaker: Dr. Francois Leonard & Dr. Andy Vance, Sandia National Laboratory, CA
- Abstract: Phototransduction plays a central role in key natural processes such as vision and photosynthesis. For these processes, natural evolution has found exquisite solutions that optimize efficiency, compactness, and self-healing. While researchers have long tried to supplant nature's successes using solid-state approaches, our ability to convert optical radiation to electrical signals with nanoscale precision still remains in its infancy. An alternative to solid-state approaches is one that more closely mimics natural processes by integrating chemical or biological materials with solid-state materials. To this end, we present a nanoscale color detector based on a single-walled carbon nanotube functionalized with azobenzene chromophores, where the chromophores serve as photoabsorbers and the nanotube as the electronic read-out. By synthesizing chromophores with specific absorption windows in the visible spectrum and anchoring them to the nanotube surface, we demonstrate the controlled detection of visible light of low intensity in narrow ranges of wavelengths. Our measurements suggest that upon photoabsorption, the chromophores isomerize from the ground state trans configuration to the excited state cis configuration, accompanied by a large change in dipole moment, changing the electrostatic environment of the nanotube. We will also present our all-electron ab initio calculations that are used to study the chromophore-nanotube hybrids and show that the chromophores bind strongly to the nanotubes without disturbing the electronic structure of either species. Calculated values of the dipole moments support the notion of dipole changes as the optical detection mechanism.
- Host: Mark Eriksson
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Electroweak Baryogenesis in Supersymmetric U(1)' Models
- Time: 4:00 pm
- Place: 4274 Chamberlin
- Speaker: Tao Liu, University of Chicago
- Abstract: I will discuss electroweak baryogenesis (EWBG) in supersymmetric
U(1)' models. Unlike the usual wisdom, a spontaneous CP violation
plays a key role in this picture. This makes the EWBG in the U(1)'
models be very different from what happens in the minimal
supersymmetric standard model. I will also show that a successful
EWBG and an acceptable neutralino dark matter relic density can be
simultaneously achieved in our models. - Host: Michael Ramsey-Musolf
Friday, February 12th, 2010
- Theory/Phenomenology Seminar
- Boosting BSM Higgs Discovery with Jet Substructure
- Time: 2:30 pm
- Place: 5280 Chamberlin Hall
- Speaker: Adam Martin, Fermilab
- Host: Neil Christensen
- Physics Department Colloquium
- Magnetohydrodynamic Turbulence
- Time: 4:00 pm
- Place: 2241 Chamberlin Hall (coffee at 3:30 pm)
- Speaker: Stanislav Boldyrev, University of Wisconsin, Department of Physics
- Abstract: Magnetic fields are ubiquitous in the universe. Their interaction with an electrically conducting fluid gives rise to a complex system - a magnetofluid - whose dynamics is quite distinct from that of either a non conducting fluid, or that of a magnetic field in a vacuum. The scales of these interactions vary in nature from meters to megaparsecs and in most situations, the dissipative processes occur on small enough scales that the resulting flows are turbulent.
There are significant differences between regular fluid turbulence and magnetohydrodynamic turbulence. We are constantly immersed in regular turbulence. We have a direct experience of it in our everyday life. Thus our development of models and theories of regular turbulence is strongly guided by experimental data and intuitions. Not so for magnetohydrodynamic (MHD) turbulence. Even though MHD turbulence is very widespread in the universe, we have practically no direct experience of it in our daily pursuits. Rather, we have to rely on numerical simulations and, to a lesser extent, observations and experiments. The purpose of this talk is to discuss what is currently known about the properties of magnetohydrodynamic turbulence. Saturday, February 13th, 2010
- Wonders of Physics
- Wonders of Physics Public Presentations
- Time: 1:00 pm
- Place: 2103 Chamberlin Hall
- Speaker: Clint Sprott, University of Wisconsin - Madison
- Abstract: In 1984, the University of Wisconsin - Madison, Department of Physics began a program called The Wonders of Physics aimed at generating interest in physics among people of all ages and backgrounds. The heart of the program is a fast-paced presentation of physics demonstrations carefully chosen to be entertaining as well as educational.
Free tickets are recommended and are available using the On-Line Ticket Form. Alternately, you may call (608) 262-2927 or e-mail wonders@physics.wisc.edu - Host: Clint Sprott
- Wonders of Physics
- Wonders of Physics Public Presentations
- Time: 4:00 pm
- Place: 2103 Chamberlin Hall
- Speaker: Clint Sprott, University of Wisconsin - Madison
- Abstract: In 1984, the University of Wisconsin - Madison, Department of Physics began a program called The Wonders of Physics aimed at generating interest in physics among people of all ages and backgrounds. The heart of the program is a fast-paced presentation of physics demonstrations carefully chosen to be entertaining as well as educational.
Free tickets are recommended and are available using the On-Line Ticket Form. Alternately, you may call (608) 262-2927 or e-mail wonders@physics.wisc.edu - Host: Clint Sprott
- Wonders of Physics
- Wonders of Physics Public Presentations
- Time: 7:00 pm
- Place: 2103 Chamberlin Hall
- Speaker: Clint Sprott, University of Wisconsin - Madison
- Abstract: In 1984, the University of Wisconsin - Madison, Department of Physics began a program called The Wonders of Physics aimed at generating interest in physics among people of all ages and backgrounds. The heart of the program is a fast-paced presentation of physics demonstrations carefully chosen to be entertaining as well as educational.
Free tickets are recommended and are available using the On-Line Ticket Form. Alternately, you may call (608) 262-2927 or e-mail wonders@physics.wisc.edu - Host: Clint Sprott
Sunday, February 14th, 2010
- Wonders of Physics
- Wonders of Physics Public Presentations
- Time: 1:00 pm
- Place: 2103 Chamberlin Hall
- Speaker: Clint Sprott, University of Wisconsin - Madison
- Abstract: In 1984, the University of Wisconsin - Madison, Department of Physics began a program called The Wonders of Physics aimed at generating interest in physics among people of all ages and backgrounds. The heart of the program is a fast-paced presentation of physics demonstrations carefully chosen to be entertaining as well as educational.
Free tickets are recommended and are available using the On-Line Ticket Form. Alternately, you may call (608) 262-2927 or e-mail wonders@physics.wisc.edu - Host: Clint Sprott
- Wonders of Physics
- Wonders of Physics Public Presentations
- Time: 4:00 pm
- Place: 2103 Chamberlin Hall
- Speaker: Clint Sprott, University of Wisconsin - Madison
- Abstract: In 1984, the University of Wisconsin - Madison, Department of Physics began a program called The Wonders of Physics aimed at generating interest in physics among people of all ages and backgrounds. The heart of the program is a fast-paced presentation of physics demonstrations carefully chosen to be entertaining as well as educational.
Free tickets are recommended and are available using the On-Line Ticket Form. Alternately, you may call (608) 262-2927 or e-mail wonders@physics.wisc.edu - Host: Clint Sprott