Oklahoma State Physics Department

Seminars and Colloquia, July through December, 1998

• This Week's schedule.
• Earlier Semesters.
• Typical Week's schedule.
• August 17-21, 1998's schedule.
• August 24-28, 1998's schedule.
• August 31-September 4, 1998's schedule.
• September 7-11, 1998's schedule.
• September 14-18, 1998's schedule.
• September 21-25, 1998's schedule.
• September 28-October 2, 1998's schedule.
• October 5-9, 1998's schedule.
• October 12-16, 1998's schedule.
• October 19-23, 1998's schedule.
• October 26-30, 1998's schedule.
• November 2-6, 1998's schedule.
• November 9-13, 1998's schedule.
• November 16-20, 1998's schedule.
• November 23-27, 1998's schedule.
• November 30-December 4, 1998's schedule.
• December 7-11, 1998's schedule.
• December 14-18, 1998's schedule.

Seminars and Colloquia, Typical Week:

Laser and Photonics Research Seminar:

Physics Undergraduate Journal Club:

Physics Colloquium:

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Journal Club on Biophysics:

Journal Club on Statistical Mechanics and Condensed Matter Physics (Informal):

Oklahoma State Physics Department

Seminars and Colloquia, August 17-21, 1998

No Seminars: First Week of Classes

Oklahoma State Physics Department

Seminars and Colloquia, August 24-28, 1998

Journal Club on Statistical Mechanics and Condensed Matter Physics (Informal):

Oklahoma State Physics Department

Seminars and Colloquia, August 31-September 4, 1998

Center for Laser and Photonics Research Seminar:

Abstract:

Coherent THz radiation generated using femtosecond laser pulses has been a hot issue recently. In this talk, several topics related to the measurement and the manipulation of the THz radiation will be presented. These include the comparison of the THz wave forms measured by photoconductive and electro-optic sampling, THz pulseshaping using femtosecond optical pulseshaper, and the generation of high power narrowband THz generation using pulseshaper and photoconductive emitter.

Physics Undergraduate Journal Club:

Professor Peter Shull will lead a discussion of the article entitled GALAXIES IN THE YOUNG UNIVERSE which appears in the May 1997 issue of Scientific American.

"By comparing distant primeval galaxies with older ones nearby, astronomers hope to determine how many galaxies form and evolve."

Copies of this article may be picked up (free of charge) in PS 145, the General Physics office, anytime prior to the discussion.

The Physics Undergraduate Journal Club welcomes all who wish to expand their interests in science through reading and discussing articles in semi-popular journals such as Scientific American. Topics range from cosmology to biophysics. Each discussion will be led by a Physics faculty member. The meetings are held every other Monday at 4:30 pm in PS 147 beginning August 31. The discussions are anticipated to last approximately one hour, but some participants may wish to stay longer. Reading materials for the up-coming discussions will be available in PS 145. One hour academic credit may be obtained by signing up for PHYSC 4010.1. However, you need not be registered to participate. Watch for the announcements of articles to be discussed.

Physics Colloquium:

Abstract:

With the prospect of long-term space missions, nuclear fission reactors and nuclear waste storage issues, the behavior of crystalline ceramics in a radiation environment is gaining increasing interest. Heavy-ion beams with energies of about 100 keV are an excellent tool for studies of structural effects in crystals due to radiation arising from nuclear reactions or radioactive decay processes on laboratory time scales. An important task for the materials scientist is to identify ceramics that are particularly radiation tolerant, and to relate their radiation toughness to crystal structure, atomic composition and macroscopic materials parameters. The present talk addresses basic ion-induced damage processes and gives examples of recent ion-beam studies on ceramics carried out at Los Alamos.

Note:

Refreshments will be served at 3:30 PM, Room PS 147.

Dinner at Stillwater Bay, 6:15 PM (sign-up sheet in main office).

Journal Club on Statistical Mechanics and Condensed Matter Physics (Informal):

Oklahoma State Physics Department

Seminars and Colloquia, September 7-11, 1998

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Please note that this new time is for this week only. Our regular time is Friday, from 1:30-3:00pm.

Journal Club on Statistical Mechanics and Condensed Matter Physics (Informal):

Oklahoma State Physics Department

Seminars and Colloquia, September 14-18, 1998

Physics Undergraduate Journal Club:

Professor Bruce Ackerson will lead a discussion of the article entitled Laser Scissors and Tweezers which appears in the April 1998 issue of Scientific American.

"Researchers are using lasers to grasp single cells and tinier components in vices of light while delicately altering the held structures. These lasers offer new ways to investigate and manipulate cells."

Copies of this article may be picked up (free of charge) in PS 145, the General Physics office, anytime prior to the discussion.

The Physics Undergraduate Journal Club welcomes all who wish to expand their interests in science through reading and discussing articles in semi-popular journals such as Scientific American. Topics range from cosmology to biophysics. Each discussion will be led by a Physics faculty member. The meetings are held every other Monday at 4:30 pm in PS 147. The discussions are anticipated to last approximately on hour, but some participants may wish to stay longer. Reading materials for the up-coming discussions will be available in PS 145.

Physics Colloquium:

Abstract:

The transverse eigenmodes of optical resonators with circular symmetry and no apertures are the Gauss-Laguerre modes. They circulate around the cavity with no loss and a mode dependent frequency shift. When a hard aperture is introduced, these modes experience distortion, loss, and frequency shift. It will be shown that these effects depend only on the trace of the ray matrix and the aperture size. Three methods of calculating the distorted modes will be compared. Results will be presented that illustrate that some distorted modes suffer negligible loss in nearly unstable cavities.

Note:

Refreshments will be served at 3:00 PM, Room PS 147.

Dinner at Red Lobster, 6:00 PM (sign-up sheet in main office). Reception at Prof. Bandy's Residence, 8:00 pm.

OSU Biophysics Journal Club:

Abstract:

Proteins are able to perform an enormous variety of functions, while using only a limited number of underlying processes. One of these is proton transfer, which plays vital roles in biological signal transduction, energy transduction, and enzymatic catalysis. We will address proton transfer events occurring in a number of photoreceptors and biological energy transducers, including photoactive yellow protein, retinal proteins, and green fluorescence protein, and provide a coherent view of proton transfer processes in term of structure, driving forces, and dynamics. We will also discuss the roles of proton transfer in biological functions of proteins.

Center for Laser and Photonics Research Seminar:

Abstract:

IV-VI semiconductors such as PbTe, PbSe, PbS, and PbSnTe have been used for the fabrication of mid- and far-infrared lasers of 2.5 to 30µm range. IV-VI lasers are still the most favorable mid-IR lasers because of their high CW operation temperature. The worldwide IV-VI diode laser activities and their applications are reviewed. Results of PbSe-based quantum well lasers will be presented. A brief comparison of mid-IR lasers among IV-VI lasers, GaSb-based lasers and quantum cascade lasers suggests that for spectroscopic applications the best choice is to further develop lasers that have IV-VI semiconductors as the active material. Preliminary results of two new mid-IR laser structures will be discussed.

Refreshments will be served.

Oklahoma State Physics Department

Seminars and Colloquia, September 21-25, 1998

Physics Colloquium:

Abstract:

Not available

Note:

Refreshments will be served at 3:00 PM, Room PS 147.

Dinner at Stillwater Bay, 6:00 PM (sign-up sheet in main office). Reception at Prof. Bandy's Residence, 8:00 pm,
(call x7587 or contact main office to sign-up).

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Oklahoma State Physics Department

Seminars and Colloquia, September 28-October 2, 1998

Physics Undergraduate Journal Club:

Professor Larry Scott will lead a discussion on Computer Simulations in Biophysics: Unraveling the Mystery of Protein Folding.

Copies of the articles may be picked up (free of charge) in PS 145, the General Physics office, anytime prior to the discussion.

The Physics Undergraduate Journal Club welcomes all who wish to expand their interest in science through reading and discussing articles in semi-popular journals such as Scientific American. Topics range from cosmology to biophysics. Each discussion will be led by a Physics faculty member. The meetings are held every other Monday at 4:30 pm in PS 147. The discussions are anticipated to last approximately one hour, but some participants may wish to stay longer.

Physics Colloquium:

Abstract:

Bacteriorhodopsin is an integral protein in the plasma membrane of Halobacterium salinarium. Upon light absorption, it converts light energy into the electrochemical energy of protons via proton transports across the membrane. It is the simplest known active ion pump. Consequently, it is a prototype system to study basic concepts of biological energy conversion. The talk will discuss different aspects of the light induced reaction sequence of the molecule during which the proton transport takes place. Photoelectric experimental methods will be introduced by which the charge motions during function can be determined. A novel technique is described in detail that is able to determine all three spatial components of the charge displacements originating from the transported proton and from the motions of charged parts of the protein during conformational changes. The experimental data are compared to molecular dynamics simulations.

Dinner at Mexico Joe's, 6:00 PM (sign-up sheet in main office).

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Oklahoma State Physics Department

Seminars and Colloquia, October 5-9, 1998

No talks scheduled in view of Fall Break

Oklahoma State Physics Department

Seminars and Colloquia, October 12-16, 1998

Fall Break

Physics Undergraduate Journal Club:

The Journal Club will not meet on Monday October 12. There will be two meetings in October. One October 19, the other October 26.

Physics Colloquium:

Abstract:

Neutrinos are almost nothing because they are almost undetectable, but they are the focus of one of the hottest topics of particle physics research today. The "discovery" of neutrino mass was even reported this June by the world news media. In this talk, I will give an overview of the fundamental issues of neutrino mass and neutrino identity, and assess the present status of our understanding in the context of all existing experimental data.

Refreshments will be served at 3:00 PM, Room PS 147. Dinner at Stillwater Bay, 6:00 PM (sign-up sheet in main office).

There will also be a reception at Dr. Babu's. There is a sign-up sheet in the main office.

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Abstract:

Although it is almost certain that the top quark was discovered at Fermilab, a loophole exists that it may be something else. I discuss one contorted possibility which is somewhat motivated by the slight experimental discrepanacy in the decay of Z into b quarks and the theoretical desirability of neutrino masses.

OSU Biophysics Journal Club:

Abstract:

Until Gilbert Ling's invention of microelectrodes in the 1940's there was no direct way to measure the cell membrane potential between the cytoplasm and bath solution. Experiments with large neurons (squid axon) suggested membrane potentials for large cells but did not predict membrane potentials. Although microelectrodes are very efficient for measuring one cell, they are impractical for use in measuring multiple cells. Riding the rescue of electrophysiologists was Leslie Loew who developed a dye that has proved moderately successful in analyzing the membrane potential multiple cells in complex environments (that is tissues rather than isolated cells).

During the seminar I'll present some of my work and the models for membrane interaction with this dye and others. We'll then discuss how such a dye might be improved and how.

Oklahoma State Physics Department

Seminars and Colloquia, October 19-23, 1998

Physics Undergraduate Journal Club:

Professor Al Rosenberger will lead a discussion on Seth Putterman's article entitled Sonoluminescence: Sound into light, which appears in Scientific American.

Abstract: A bubble of air can focus acoustic energy a trillion fold to produce picosecond flashes of light. The mechanism eludes complete explanation.

Copies of the articles may be picked up (free of charge) in PS 145, the General Physics office, anytime prior to the discussion.

The Physics Undergraduate Journal Club welcomes all who wish to expand their interest in science through reading and discussing articles in semi-popular journals such as Scientific American. Topics range from cosmology to biophysics. Each discussion will be led by a Physics faculty member. The meetings are held every other Monday at 4:30 pm in PS 147. The discussions are anticipated to last approximately one hour, but some participants may wish to stay longer.

Oklahoma State Physics Department

Seminars and Colloquia, October 26-30, 1998

Physics Undergraduate Journal Club:

Professor Bruce Ackerson will lead a discussion on the article entitled Science versus Antiscience?, which appears in Scientific American.

Abstract: Movements lumped under the term "antiscience" have disparate causes, and not all pose as much a threat as has been claimed.

Copies of the articles may be picked up (free of charge) in PS 145, the General Physics office, anytime prior to the discussion.

The Physics Undergraduate Journal Club welcomes all who wish to expand their interest in science through reading and discussing articles in semi-popular journals such as Scientific American. Topics range from cosmology to biophysics. Each discussion will be led by a Physics faculty member. The meetings are held every other Monday at 4:30 pm in PS 147. The discussions are anticipated to last approximately one hour, but some participants may wish to stay longer.

Physics Colloquium:

Abstract:

Not available

Note:

Refreshments will be served at 3:00 PM, Room PS 147.

Dinner at Stillwater Bay, 6:00 PM (sign-up sheet in main office). Reception at Prof. Bandy's Residence, 8:00 PM.

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Oklahoma State Physics Department

Seminars and Colloquia, November 2-6, 1998

OSU Physics Department and Center for Sensors & Sensor Technologies Colloquium:

Abstract:

Chemical and biological sensor can be useful in the detection of hazardous and polluting chemicals; the detection of petroleum products in the bore-hole and drilling fluids; the detection of gases in the intake and exhaust of internal combustion engines; the detection harmful/toxic bacteria in hamburger, and many other areas. The CO detector in your house is a solid-state colorimetric detector.

In this presentation, I will discuss concepts in the design of chemical and biological sensing materials, including detection speed (real-time), physical construction (solid-state), dynamic range, and specificity. The use of ab initio and semi-empirical modeling of indicator-analyte complexes will be introduced.

Note:

Refreshments will be served at 3:00 PM, Room PS 147.

Oklahoma State Physics Department

Seminars and Colloquia, November 9-13, 1998

Physics Undergraduate Journal Club:

Professor Penger Tong will lead a discussion on the article entitled Tackling Turbulence with Supercomputers, which appears in Scientific American.

Abstract: Computers only recently became powerful enough to illuminate simple examples of this great classical problem. In some cases they will let engineers control it.

Copies of the articles may be picked up (free of charge) in PS 145, the General Physics office, anytime prior to the discussion.

The Physics Undergraduate Journal Club welcomes all who wish to expand their interest in science through reading and discussing articles in semi-popular journals such as Scientific American. Topics range from cosmology to biophysics. Each discussion will be led by a Physics faculty member. The meetings are held every other Monday at 4:30 pm in PS 147. The discussions are anticipated to last approximately one hour, but some participants may wish to stay longer.

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Physics Department Colloquium:

Abstract:

Ultrafast optical phenomena refers to dynamical processes that occur in various forms of matter on the time scale of picoseconds (10^-12 s, ps) or femtoseconds (10^-15 s, fs). These phenomena have been relegated to the optical domain, primarily because only lasers have been fast enough to probe many of these processes. Laser pulses as short as 4.5 fs have been generated and utilized to study various physical phenomena. Ultrashort pulses of light have been utilized in fundamental studies of disciplines as diverse as semiconductor physics, lightwave transmission systems, and biological systems. Recently, for example, a group at Lawrence Berkeley Laboratory reported that the initial steps in the process of vision occur in approximately 200 fs. On another research front, ultrashort pulses have led to the generation of extremely high peak power pulses of approximately 100 TW (TW=Terawatt=10¹² W) and intensities of nearly 10²⁰ W/cm². One application of these intense pulses is in the generation of soft X-rays, for use in X-ray lithography. Ultrafast optical phenomena continues to be a highly prolific field of fundamental and applied research. I will describe several of the techniques used by ultrafast opticists to measure events on this incredibly short time scale and review some of the latest advances in this field.

Refreshments will be served at 3:00 PM, Room PS 147.

Reception will be at Wicksted's Residence (Map in Office, PS II 145).

Oklahoma State Physics Department

Seminars and Colloquia, November 16-20, 1998

OSU Biophysics Journal Club:

Abstract:

Most enzymes of the major metabolic paths are found in the "soluble fraction" of cellular extracts and many attempts to demonstrate enzyme complexes failed. Hence the dogma for the last 50 years has considered these enzymes, and hence their metabolites, to be randomly distributed in their cellular organelles. However, compelling evidence has accumulated in the last 20 years showing that many if not most of these enzymes exist in enzyme-enzyme complexes or at least co-localized, and that the metabolites can be passed between the donor and acceptor enzymes in the path without mixing with the bulk phase ("substrate channeling"). This imbues the metabolic path with very different kinetic and equilibrium properties from that of the classical model. I will discuss research on these phenomena, namely spatial organization of enzymes in vivo and mechanisms of substrate channeling.

Oklahoma State Physics Department

Seminars and Colloquia, November 23-27, 1998

Physics Undergraduate Journal Club:

Abstract: A team of US and Japanese physicists has recently obtained convincing evidence that neutrinos have mass. The significance of this discovery will be the topic of discussions.

References:

1. Scientific American, August 1998; page 18
2. New York Times, June 5, 1998; page 1
3. Physics World, July 1998; page 17

Copies of the articles may be picked up (free of charge) in PS 145, the General Physics office, anytime prior to the discussion.

The Physics Undergraduate Journal Club welcomes all who wish to expand their interest in science through reading and discussing articles in semi-popular journals such as Scientific American. Topics range from cosmology to biophysics. Each discussion will be led by a Physics faculty member. The meetings are held every other Monday at 4:30 pm in PS 147. The discussions are anticipated to last approximately one hour, but some participants may wish to stay longer.

Thanksgiving

Oklahoma State Physics Department

Seminars and Colloquia, November 30-December 4, 1998

Prefinals Week

Physics Department Colloquium:

Abstract:

Superstring theory is an elegant theoretical framework providing a unified description of gravity, quantum mechanics, gauge forces, and matter. Until recently it was thought that the natural energy scale for superstring physics was set by the reciprocal square root of Newton's gravitational constant G. Since this energy scale is a factor of 10¹⁶ times the reach of current particle accelerators, it was thought that superstring theory could have no direct overlap with experiments. It is now believed that the fundamental energy scale of superstring physics may be far lower, perhaps as low as 1 to 10 TeV. In this case current and future particle colliders can probe or constrain a rich variety of new physical phenomena associated with superstrings. These new phenomena include effects from new dimensions of space, quantum gravity, and the vibrational modes of the superstring.

Refreshments will be served at 3:00 PM, Room PS 147.

Oklahoma High Energy Physics Seminar on Talk-Back Television:

Oklahoma State Physics Department

Seminars and Colloquia, December 7-11, 1998

Finals Week

Oklahoma State Physics Department

Seminars and Colloquia, December 14-18, 1998

No talks scheduled at this time.

Last Updated: by Helen Au-Yang and Jacques H.H. Perk.