ISU Physics Teacher Education on the World Wide Web. Carl J. Wenning, Illinois State University, Normal, IL 61790-4560. The World Wide Web is having a significant impact on the way that some of us teach and make information available to our students. The majority of the faculty members of the Illinois State University Physics Department use the Web to assist with teaching, testing, grading, advisement, recruitment, and retention. ISU’s Physics Teacher Education Program has a major presence on the Web at http://www.phy.ilstu.edu/pte.html. The presenter will demonstrate the uses of the physics teacher education website at ISU.
Equipment needs: computer with Internet access/video projector
Comments: I would prefer to present the talk on Friday. I'd like to have 15 min + 5 for Q&A.
Using Superconductivity Research as a Teaching Tool. David K. Rigsbee and Mark S. Boley, Western Illinois University, Macomb, IL 61455. To involve students in research is to teach them the very process of discovery; and at the same time how to apply their observation, measurement and creative thinking skills. At the WIU Physics Department in Macomb, Dr. Boley's students develop these traits in the context of his high temperature superconductivity research program. Students benefit from a close student-professor relationship, and working together from experiment design and sample preparation, through building and maintaining the test equipment, collecting and analyzing data, and finally reporting results. A master's degree thesis student, three graduate research assistants, several undergraduate students, and even a high school student are involved in this program. This is a very effective method of adding depth to the standard physics curriculum.
Equipment needs: overhead projector
Comments: Saturday morning preferred / about 15 minutes
Investigation of the Effects of Cobalt Doping on Copper Oxide Superconductors. Amul Tevar and Mark S. Boley, Department of Physics, Western Illinois University, Macomb, IL 61455. Cobalt (Co) substitutions for Copper (Cu) atoms in molar proportions of 0.1%, 0.2%, and 0.3% in the crystalline lattice of the cuprate oxide superconductor YBa2Cu3O7-x produced marked enhancement effects in the magnetic field and temperature dependence of the transport critical current density in bulk polycrystalline samples. These samples, along with a control sample, were sintered in pellet form using conventional ceramic processing techniques, and then subjected to four-wire probe critical state investigations at temperatures from 44K to 90K and magnetic fields up to 1.2 Tesla. The 0.2% dopant level demonstated the most pronounced weakening in field dependence of the critical current without noticeable degradation of the resistivity versus temperature curve for the sample. On the other hand, by the 0.3% Co dopant level, a small normal state resistivity persisted below 60K, causing a severe reduction in any critical current sustained by the sample.
Equipment needs: overhead projector
Comments: prefer Saturday morning (about 15 minutes) / presented as part of the Student Research Symposium
Investigation of the Effects of Neutron Irradiation on In-field Critical Current Density in Superconductor Ho-Ba-Cu-O. Doug Franklin, Nobuyuki Tsuchiya, Matt Walker, and Mark S. Boley, Department of Physics, Western Illinois University, Macomb, IL 61455. The use of neutron irradiation to introduce structural defects in the crystalline lattice leads to enhanced critical current behavior in the presence of a magnetic field in the cuprate superconductor HoBa2Cu3O7-x. Utilizing a one Curie Am-Be neutron source for the sample irradiation is preferable to a large neutron flux as from a reactor, not only because of cost and availability, but also due to minimal residual radioactivity and more controlled defect production in irradiated samples. After a two week irradiation, the sample radioactivity only slightly exceeds background levels, while critical state measurements at 77K and 67K indicate a significant weakening of the magnetic field dependence of the transport critical current density in most of our samples. Mechanical spring-loaded contacts in a four-wire probe configuration were used on pelletized polycrystalline samples in all measurements.
Equipment needs: overhead projector, laser pointer
Comments: prefer Saturday morning/ about 20 minutes
Enhancements in High Temperature Superconductivity Data Acquisition Techniques. Clay D. Nall, Benjamin D. Murphy, and Mark S. Boley, Department of Physics, Western Illinois University, Macomb, IL 61455. Most conventional transport critical current density measurements for bulk superconducting samples required continuous multiple user adjustments and monitoring. In our laboratory, a customized C++ program allows the computer to control data acquisition equipment via automated task control with single user-set parameters. This greatly decreases the amount of time between consecutive measurements, thus also reducing any errors produced by sample heating. Additionally, a uniquely designed spring-loaded mechanical contact assembly in a four-wire probe configuration allows for constant contact pressure on a bulk pelletized polycrystalline sample even during large temperature changes, thus minimizing the undesirable contact voltage fluctuations often generated by thermal expansion and contraction in solder joints or painted leads.
Equipment needs: overhead projector
Comments: 15 minutes/ prefer Saturday morning/ part of Undergraduate StudentResearch Symposium
More Physics From Toys-R-Us. Ann Brandon & Deborah Lojkutz, Joliet West High School, Joliet, IL 60435. We will use a Push 'N' Go to demonstrate Newton's Laws of Motion. Fun in Physics for less than $5 per setup.
Equipment needs: Overhead Projector
Comments: Whenever. 20 minutes needed
Two-Liter Physics. Vickie Frohne, Western Illinois University, Macomb, IL 61455. Many lecture demonstrations can be performed using apparatus made from recycled two-liter and 0.24 liter (20 oz.) soft-drink bottles. Several of these will be described, including the two-liter "return" bottle, the laser fountain, the pressure fountain, the accelerometer, the hydrostatic balance, the thermal sand shaker, and others. Many of these pieces of apparatus are simple enough to be made by students in a classroom setting.
Equipment needs: overhead projector
Comments: Sat. morning, length 15 mins., might possibly bring apparatus to demonstrate (please advise if room has water & sink)
The Freedericksz transition in liquid crystals: an experiment for the advanced laboratory. Thomas Moses and Brian Jensen, Knox College, Galesburg, IL 61401. The Freedericksz transition is a magnetically-induced reorientation of the molecules of a liquid crystal. We describe here an experimental investigation of the Freedericksz effect in liquid crystals for the advanced undergraduate laboratory. Besides introducing students to the novel and fascinating liquid crystalline state of matter, the experiment serves as a valuable introduction to light propagation in an optically anisotropic medium and to the use of the calculus of variations in a somewhat unusual context. All components for the experiments are readily available and reasonably inexpensive.
Equipment needs:
Comments: Sat. morning preferred, 15 minutes
An NMR Investigation of Hydrogen Motion in Quasicrystalline TiZrNi. Nick Stojanovich, N.L.Adolphi, A.McDowell, Knox College, Galesburg, IL 61401. Hydrogen motion in quasicrystalline TiZrNiH has been studied using nuclear magnetic resonance to measure spin-lattice (T1) and spin-spin (T2) relaxation times as a function of temperature and frequency. T1 measurements at 15.8, 38.5, and 85 MHz from 100K to 500K indicate that the model relating T1 to the rate of hydrogen motion (which assumes a single activation energy for hopping) does not adequately describe the data. A Gaussian distribution of activation energies with an average activation energy of 0.35eV and an rms width of 0.04eV was employed to account for the asymmetry of the 1/T1 vs. T peaks. Over the course of the experiment, the electronic contribution to the relaxation decreased, suggesting that some hydrogen may have been lost due to heating of the sample. Further experiments will investigate the effects of hydrogen concentration on the spin-lattice relaxation at low temperatures.
Equipment needs: Overhead projector
Comments: For Student Research Symposium. 15 minutes for the presentation.
Introduction to Nuclear Magnetic Resonance: An Inter-Disciplinary Laboratory Course. Natalie L. Adolphi and Andrew F. McDowell, Knox College, Galesburg, IL 61401. Nuclear Magnetic Resonance (NMR) has become a standard experimental and diagnostic technique in Physics, Chemistry, Biology, and Medicine. Unfortunately, many of the practitioners of NMR don't have a clear understanding of the physical basis of the experiment and often treat the NMR spectrometer as a "black box." In the introductory course we are currently devoloping and teaching, we aim to demystify NMR through a series of short, hands-on exercises using a simple, homebuilt NMR spectrometer. The topic also affords one the opportunity to bring together science students from different disciplines, some of whom have encountered NMR in a course or in research, and many of whom will use NMR at some point in their scientific careers.
Equipment needs: overhead
Comments: 20 minutes will be fine. In addition to the talk, I could do a quick tour of the NMR teaching lab as a take-5.