Bulletin of the American Physical Society
2005 7th Annual Meeting of the Northwest Section
Friday–Saturday, May 13–14, 2005; Victoria, BC, Canada
Session A1: Plenary I |
Hide Abstracts |
Chair: Larry Hall, Boeing Corp. Room: MacLaurin 144 |
Friday, May 13, 2005 8:30AM - 8:35AM |
A1.00001: Introduction J. Michael Roney |
Friday, May 13, 2005 8:35AM - 8:40AM |
A1.00002: Welcoming Remarks Tom Pedersen |
Friday, May 13, 2005 8:40AM - 9:16AM |
A1.00003: Sizing up the Universe Invited Speaker: The Wilkinson Microwave Anisotropy Probe (WMAP) has delivered our sharpest view yet of the early Universe. The WMAP data has ushered in a new era of precision cosmology, yielding tight constraints on the age, composition and curvature of the Universe. But the WMAP data was not without it surprises: it appears that the first stars formed much earlier than expected, and there are a number of puzzling features to be found in the large scale anisotropies. It has been suggested that these strange features are a sign that the Universe is spatially finite. We are able to test this hypothesis by looking for a tell-tale signature in the WMAP data. Turning the search around, the absence of such a signature can be used to place a lower bound on the size of the Universe. I will describe recent progress in our search for topological signatures in the WMAP data, and announce some new results. [Preview Abstract] |
Friday, May 13, 2005 9:16AM - 9:52AM |
A1.00004: Improving the Performance and Durability of Solid Oxide Fuel Cells Invited Speaker: Fuel cells are highly efficient devices that cleanly and quietly convert chemical energy into electricity. Indeed, certain types of fuel cells have theoretical fuel-to-electricity conversion efficiencies close to 100{\%} and have realizable efficiencies approaching 50{\%}. There are a number of types of fuel cells that are currently in various stages of development, but it is generally accepted that proton exchange membrane fuel cells (PEMFCs) and solid oxide fuel cells (SOFCs) offer the most promise of flexibility of application, fuel options, and the potential to realize high fuel conversion efficiencies. However, PEMFCs are hindered by their need for ultra-high purity ($<$50 ppm CO) H$_{2}$, while SOFCs can operate on CO/H$_{2}$-based reformates. As a consequence, SOFCs are ideally suited for less costly, readily accessible fuel supplies. However, the SOFC anode performance can be compromised by such factors as exposure to certain sulfur-containing fuels and the deposition of coke when using hydrocarbon fuels. In terms of the cathode, its performance is limited primarily by the slow kinetics of the oxygen reduction reaction, while its lifetime can be negatively affected by factors related to the corrosion of currently used stainless steel interconnect materials. This talk will present an overview of these challenges and some possible solutions to these problems. This presentation will also explain how electrochemical methods can be used to evaluate and improve the performance of SOFC anodes, cathodes, and interconnect materials. [Preview Abstract] |
Friday, May 13, 2005 9:52AM - 10:28AM |
A1.00005: The International Linear Collider Invited Speaker: The worldwide particle physics community has agreed that the next large facility required to advance the field is a linear electron-positron collider, which should operate, in the first phase, at the centre-of-mass energy of 500 GeV. This facility would provide essential information to understand the way the symmetry between the electromagnetic and weak forces is broken and point to a more complete theory of particle physics. This talk will review the main physics goals, discuss some of the interesting technical challenges for the International Linear Collider and its detectors, and present the current status and outlook for the future. [Preview Abstract] |
Friday, May 13, 2005 10:28AM - 10:48AM |
A1.00006: COFFEE BREAK
|
Friday, May 13, 2005 10:48AM - 11:24AM |
A1.00007: Physics education research as a guide to professional development of teachers K-20 Invited Speaker: It is by now well known that many students emerge from traditional physics courses without having developed a functional understanding of important basic concepts. Moreover, there is evidence that conceptual and reasoning difficulties similar to those identified among undergraduates are also found among K-12 teachers and graduate teaching assistants, and sometimes even among college and university faculty who may not remember their own struggles with the material. Examples from programs conducted by the Physics Education Group at the University of Washington will be used to illustrate how teachers of physics at all levels can be helped to deepen their understanding of the subject matter, become familiar with the difficulties it presents to students, and develop skill in using types of instructional strategies that have proved to be effective in promoting intellectual engagement. [Preview Abstract] |
Friday, May 13, 2005 11:24AM - 12:00PM |
A1.00008: Mapping the Neutrino Mixing Matrix with Long Baseline Neutrino Experiments Invited Speaker: Measurements of solar and atmospheric neutrinos have demonstrated neutrino oscillations between two pairs of the three neutrino mass eigenstates. However, the full 3x3 neutrino mixing matrix remains unexplored. Open questions include how strongly electron neutrinos couple to the third mass eigenstate, what the form is of the neutrino mass hierarchy, and whether neutrino mixings can produce CP symmetry violation. In this talk I will describe how current and future long baseline neutrino oscillation experiments can probe the neutrino mixing matrix by shooting high intensity neutrino beams produced at accelerators towards distant detectors located hundred of kilometers away. [Preview Abstract] |
Friday, May 13, 2005 12:00PM - 12:36PM |
A1.00009: Optical Properties of Silicon Nanoclusters Invited Speaker: Silicon nanoparticles have been intensively investigated since the well-known 1990 report [1] on photoluminescence in porous silicon (this original reference in Applied Physics Letters now has over 3,500 citations!). Much of the current interest stems from the myriad applications for light emitting silicon in opto-electronics and photonics, but porous silicon tends to be mechanically and chemically fragile. One of the most exciting materials instead consists of well-passivated silicon nanocrystals embedded in a matrix of silicon dioxide -- these nanocomposites emit a broad and relatively intense luminescence spectrum in the red to near infrared. When silicon nanocomposites are doped with erbium or other rare earth elements, the rare earth luminescence achieves some remarkable properties that are currently of significant technical interest. In this talk, I will briefly discuss the historical background of the work on light emitting silicon, the physics involved in the emission mechanism, the effects of doping silicon nanoclusters with rare earth ions, and the potential applications for these materials. Finally I will outline our own research group's progress in the last year toward extensive emission color control from silicon nanoclusters that can now be tuned throughout the visible spectrum and into the fiber transparency windows in the near infrared. [1] L.T. Canham, Silicon quantum wire array fabrication by electrochemical and chemical dissolution of wafers, Appl. Phys. Lett. 57, 1046 (1990). [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700