1:00     Welcome and Introductions  - Charles Schulz, Physics Dept., Knox College and Roger Taylor, President of Knox College.

1:15 - 1:30 - A1

A New Model Course in Quantum Mechanics. Tom Carter, College of Dupage, Glen Ellyn, IL 60134. I will review the use of the material from the New Model Course in quantum mechanics as part of a sophomore level Modern Physics course. The New Model Course is the result of a joint physics education research project on the part of the University of Maryland, Maine University and the City University of New York. The College of Dupage is currently a field test site for the initial version of this course. The course emphasizes interactive learning techniques and practical applications of quantum mechanics that may be of interest to engineering students. Some of the tutorials and educational software involved will be briefly presented.

1:30 - 1:45 - A2

*Physics and Sociology: Neighborhood Racial Segregation. Alexander J. Laurie and Narendra K. Jaggi, Illinois Wesleyan University, Bloomington, IL 61702. We have extended the Schelling model of neighborhood racial segregation to include agents who can authentically 'see' their neighbors up to a distance R, called 'vision'. By exploring the consequences of systematically varying R, we have developed an understanding of how vision interacts with racial preferences and minority concentrations and leads to novel, complex segregation behavior. We have discovered three regimes: an unstable regime, where societies invariably segregate; a stable regime, where integrated societies are essentially stable; and an intermediate regime where a complex behavior suggestive of a first order phase transition is observed.

1:45 - 2:00 - A3

*MFM Study of Magnetic Domains in Heat-Treated Magnetoelastic Torque Sensors. Jason Wilson, Doug Franklin, and Mark S. Boley, Department of Physics, Western Illinois University, Macomb, IL 61455. In this study, we created two distinct portions of the torque sensor ring or shaft in which a high degree of oppositely polarized circumferential magnetization was maintained with a saturated alignment of the magnetic domains due to the high circumferential coercive force. This sensory area produces a field signal linearly proportional to the applied torque. The ring sample was constructed of a steel alloy of 18% nickel in iron (known as C250, while the two shafts used were steel alloys, of 0.5% chromium and 0.3% nickel, and of 12% chromium and 0.3% nickel (known as O-1 and D-2 respectively). Previously unknown has been the exact nature of the interface between the regions of opposing circumferential magnetization. In this study, we have used the magnetic force probe of our AFM, in an imaging technique known as MFM, to determine the width and sharpness of the domain wall transition region between the two oppositely polarized regions of both types of sensors and their relative depth of magnetic alignment. We found the domain wall transition region to be much wider and to change in a more gradual manner in the shaft sensors. However, following the heat treatment of the shaft-type sensors, the width of their domain walls began to approach that of the ring-type sensor. We also found that the relative height of the domain wall signals compared to the background signals was in direct correlation with the torque load sensitivity numbers measured for each of the samples.

2:00 - 2:15 - A4

*Raman Spectral Peak Shifts Across the Superconducting Transition of MgB₂.  Matthew Edd Tillman and Mark S. Boley, Department of Physics, Western Illinois University, Macomb, IL 61455. The recently discovered magnesium diboride (MgB₂) polycrystalline superconductor has again stimulated the interest in conventional BCS superconductors that, as opposed to most high-temperature superconductors, can possess the high levels of critical current density so essential for magnetic field applications of superconducting materials. However, much remains to be learned about the structural mechanisms behind the magnesium diboride superconducting system. One of the most useful tools for an analysis of the structural features most involved in phonon-mediated superconductivity is the technique of Raman spectroscopy. In this study, we have collected the Raman spectra of a magnesium diboride polycrystalline superconductor over a large range of wavenumber shifts at temperatures ranging from 18K - 300K. We have observed the conventional gradual softening of the major Raman-active phonon mode with an increase in sample temperature. Immediately above and below the critical temperature (measured as around 38 K onset for our sample) we collected the spectra at a finer grid of temperatures in order to more accurately observe the specific phonon mode shifts as the sample passed through the superconducting transition. The Raman spectra were collected over multiple averaged scans with a GaAs PMT and a Triax 550 spectrometer equipped with a holographic Super-Notch Plus filter and were excited with 150 mW of 4880 Å argon ion laser radiation at the sample surface. These spectra have provided us with further insight into the specific phonons responsible for the mediation of the Cooper pairing of the electrons on which BCS superconductors are inherently dependent.

2:15 - 2:30 - A5

*The Effects of Chromium Concentration on Heat-Treated Steel Torque Transducer Shafts. Jason T. Orris and Mark S. Boley, Department of Physics, Western Illinois University, Macomb, IL 61455. In many applications where a sensory transducer ring would be impractical, a hollow ferromagnetic high-speed steel "shaft type" torque sensor can be constructed. This requires the creation of two distinct portions of the shaft in which a high degree of oppositely polarized circumferential magnetization can be maintained with a saturated alignment of the magnetic domains due to the high circumferential coercive force in the material. In a related work, we have found that increasing nickel concentrations improve transducer sensitivities (field signal per applied torque) but also cause the shafts to become too brittle for most torque transfer applications. In this work, we have discovered that a similar or even larger improvement in transducer sensitivity can be gained by increasing the chromium concentration (with nickel concentrations under 0.30 %) of the steel, yet without the degradation of any of its mechanical properties. The three steel shafts we investigated had respective chromium concentrations of 0.15%, 3.5%, and 12.0%, and are known as steel types W-1, S-7, and D-2. Their transducer sensitivities were found as 1.5, 4.0, and 12.5 mG/N-m, respectively, while the latter two steel shafts also exhibited still further increases in their sensitivity following their standard heat treatments, especially for the D-2 sample. The area of the axial hysteresis curves for these three steels was also found to dramatically decrease as the chromium concentration and the transducer sensitivity increased. However, relatively little change was observed in the already broad circumferential hysteresis curves, which implies that sensor integrity can be maintained.

2:30 - 2:45 - A6

Using Astronomy to Teach Physics.  Lee Carkner, Augustana College, Rock Island , IL 61201. Astronomy based problems and examples can be used as an effective means of teaching physical concepts to students of all ability levels. Astronomy is a useful topic for discussions and problems because it stimulates student interest and often can be accompanied by engaging images and multimedia. Examples of astronomy and space science based problems on topics such as motion, gravity, optics, thermodynamics and electromagnetic radiation will be presented with suggestions of how they can be best used in classes and homework assignments

3:00 - 4:15         Session C  -  Room A110
                                    Session Chair:  TBA

3:00 - 3:15 - C1

*Modeling Electromagnetic Problems Using Finite Element Analysis. James C. Gumbart and James Rabchuk, Western Illinois University, Macomb, IL 61455. Finite element analysis is a numerical approach to solving both homogeneous and inhomogeneous differential equations such as Laplace’s and Poisson’s equations. It is especially suited for problems involving complex geometries and/or inhomogeneous media. The method involves dividing the problem domain into simple elements connected together at nodes and then solving the associated equations for each element iteratively. Electricity and magnetism is one area where this method can be of great use. The effects of magnetic materials (not just permanent magnets) complicate matters greatly yet are often key to many problems. Finite element analysis is often the only sufficiently accurate recourse available for solving such problems. In applying the method, we took two approaches: using freely available software and writing our own computer program. With the software, FEMM 3.3, we analyzed a diamagnetic-assisted levitating magnet. This problem is especially challenging due to the fact that the diamagnetic materials used to produce the levitation differ in their magnetic properties from air by one part in ten thousand. Nevertheless, finite element analysis was successful in reproducing the observed sensitivity to the plate spacing as well as the upper magnet placement. As for our own code, we have seen agreement with more exact methods for various simple problems.

3:15 - 3:30 - C2

Gibbs, Feynman and the Refractive Index.  James E. Clark, Northern Illinois University, DeKalb, IL 60115. It is possible to build a bridge between Gibbs' classical 19th century thermodynamics and Feynman's 20th century presentations of electrodynamics, if the refractive index of a simple substance like liquid water is considered. Gibbs (1875) stipulates that a thermodynamic fluid phase in equilibrium must be homogeneous. This is true not only for liquid water, but for any liquid phase that can be represented by thermodynamics.  By means of the refractive index n, a connection is made between homogeneity in optics and homogeneity in thermodynamics. For liquid water the index n, is a function of the wavelength, temperature and pressure. The optical wavelength establishes a natural length scale where the pressure, temperature and the classical concept of thermodynamic homogeneity is valid. Neither Gibbs (1875-1878) nor Feynman (1963-1965, 1988) ever considered this simple but fundamental relation between thermodynamic homogeneity and optical homogeneity in their works.

3:30 - 3:45 - C3

*Static and Flowing Soap Films. Greg Sollenberger and James Rabchuk, Western Illinois University, Macomb, IL 61455. Soap films are admired for their beautiful colors that arise from the interference between the reflections off of their front and back surfaces. Because the colors seen are a function of the thickness of the soap film, they present a sort of topographical map of the soap film thickness. This effect is exploited in order to make observations of thickness variations in flowing soap films. Thickness variations (and corresponding velocity variations) can be introduced into the flow by the presence of barriers. This allows one to visualize vorticity and turbulence in the flowing film. An experiment for characterizing the turbulence in two-dimensional flows as a function of distance away from the barrier is also proposed. In addition, static soap films have the well-known property of having a minimum surface area when spanning a closed boundary, due to the surface tension in the film. This property is used to illustrate first and second order thermodynamic phase transitions. As the physical boundaries for the film are changed continuously, the configuration of the film undergoes a discontinuous change. In the second order phase transition, the phenomenon of hysteresis can demonstrated and explained in terms of the underlying thermodynamics.

3:45 - 4:00 - C4

The Effects of Nickel Concentration on Heat-Treated Steel Torque Transducer Shafts.  Laurie A. Pichla, Jason T. Orris, and Mark S. Boley, Department of Physics, Western Illinois University, Macomb, IL 61455. We have previously determined that a ferromagnetic high-speed maraging steel alloy of 18% nickel in iron (known as C250) is one of the best materials for use in the construction of a "ring type" torque sensor on a non-ferromagnetic shaft used for power transmission applications. We created two distinct portions of the ring in which a high degree of oppositely polarized circumferential magnetization was maintained with a saturated alignment of the magnetic domains due to the high circumferential coercive force. However, in many applications where a sensory ring would be impractical, the same type of magnetic arrangement can also be produced in a hollow ferromagnetic high-speed steel "shaft type" torque sensor. However, much lower nickel concentrations are required to prevent the shafts from being too brittle for most torque transfer applications; the downside of this is that we have found the transducer sensitivities to dramatically decrease with the nickel concentration. The three steel shafts we investigated had respective nickel concentrations of 0.20%, 0.30%, and 4.00%, and are known as steel types W-1, O-1, and Kapstar. Their transducer sensitivities were found as 1.5, 5.5, and 8.5 mG/N-m, respectively, while the Kapstar sample also exhibited a significant enhancement in sensitivity following the standard heat treatment of the steels. The area of the axial hysteresis curves for these three steels was found to decrease with nickel concentration, which shows a correlation between smaller axial coercive forces and larger sensitivities. There was little change in the circumferential hysteresis curves, but the values of circumferential coercive force remained large enough to maintain sensor integrity.

8:30 - 8:45 - D1

The Bridge Between Physics and Sports.  Paul Robinson and Lee Suarez, Principia College, Elsah, IL 62028. The Bridge between Physics and Sports The Athletic Director and I got together and planned a course that we hoped would form a bridge between Physics and athletics. Using texts like Adair's "The Physics of Baseball" or Hay, "The Biomechyanics of Sports Techniques." we have found a number of ways to do excellent physics with full mathematical rigor, and have all of the labs be athletic activities. Four class hours a week are spent in PE type activities modified to emphasize the physics, and six hours of class time are spent developing Mathematica or spread sheet programs modeling sports. We have even worked it out so that students get both science lab credit and PE credit for completing the course. We typically end the course with student projects including written, oral, poster and demonstration parts that center on a physical activity of the student's choice.

8:45 - 9:00 - D2

*Pretransitional Light Scattering in Isotropic Liquid Crystals.  Jason Reeves, Knox College, Galesburg, IL 61401. Fluctuations in molecular orientation, called nematic fluctuations, in the isotropic phase of cyanobiphenyls near the isotropic liquid-to-crystal phase transition were investigated experimentally using light scattering. Experiments were done on short-chain cyanobiphenyls which exhibit no stable liquid crystalline (nematic) phase, and the results compared with pretransitional fluctuations in longer-chain liquid crystalline cyanobiphenyls. Experimental results suggest that nematic fluctuations exist above the isotropic-crystal transition despite the absence of a nematic phase in these materials. The theoretical description of the temperature-dependence of the fluctuations in liquid crystals (Landau-de Gennes theory) is in qualitative agreement with the experimental data. Estimates of the minimum supercooling temperatures were in approximate accord with other experiments.

9:00 - 9:15 - D3

Physics of Sailing. Benjamin L. Brown, Principia College, Elsah, IL 62028.  Many principles of physics are demonstrated in the design and operation of a modern sailing vessel. A typical sloop with a “Marconni rig” can make forward progress against the wind, something that can seem baffling to the uninitiated. In addition to this application of Bernoulli’s principle, the buoyancy of the boat itself, the center of mass, center of buoyancy, stability, center of effort, and center of lateral resistance provide grist for a physics teacher's mill. Vector representation is necessary for simple navigation and a mechanical advantage is often obtained on-board with winches, block and tackle, or a simple lever. Considering these examples, and many more that could be conjured, one might conclude that the best way to teach introductory mechanics is to go sailing.

9:15 - 9:30 - D4

*Model Equations for Chaotic Plasma Synchronization. Kent Schonert, Epaminondas Rosa, Jr. and George Rutherford, Illinois State University, Normal, IL 61761.  Certain chaotic oscillators are able to have their phases synchronized with the phase of periodic forcing oscillator. In this phase synchronized state, the phase of the two oscillators are in step with each other while their amplitudes remain uncorrelated. The phenomenon has been demonstrated numerically and also has been observed experimentally. In further research, we intend to phase synchronize a chaotic oscillator with a signal from another chaotic oscillator instead of a periodic one. In particular, we would like to phase synchronize two experimental chaotic systems: a Chua and Plasma circuit oscillator. Each of these systems can be represented by three coupled equations representing an experimental setup. We show our simulation in preparation to compare with a possible future experimental setup.

9:30 - 9:45 - D5

*Evidence of Dark Cone in Backscattered Light off Turbid Media.  Allen Lewis, Rainer Grobe and Qichang Su, Illinois State University, Normal, IL 61790-4560. Using a Monte Carlo approach we study the propagation of light through a two-dimensional random medium. We observe a cone-shaped region in space close to the location where the input light is injected into the medium where the diffusively reflected light for points close to the axis of the incoming light is much weaker than for points further away. We investigate this dark cone formation numerically and show that this effect can be directly related to the width of the scattering phase function and the scattering coefficient. [1] * Supported by grants of the NSF, Research Corporation, Illinois State URG and Honors Program. [1] A.F. Lewis, M.S. Bell, R.E. Wagner, Q. Su and R. Grobe, Laser Phys., in press.

10:00 - 10:15 - E1

*Wave Theory for Light Scattering in Random Media.  Matthew Narter and Sunish Menon, Illinois State University, Normal, IL 61790-4560. We study the usefulness of transfer matrix theory for randomly arranged plane parallel dielectric slabs. Using a computer generated random number sequence, the dielectric slabs are assigned a random refractive index, width and position in a specified range, thus simulating a random medium. We will show how the effective transmission and reflection coefficient of such media can be calculated using the transfer matrix theory. In contrast to the crystal, we will show that the response of the random media is characterized by highly oscillatory, irregular, resonance structures. These resonance structures are not present in a macroscopic response and, we will discuss procedures that can be used to find the macroscopic response of the random media. Finally, we will discuss some applications of this study. * Supported by grants of the NSF, Research Corporation, Illinois State URG and Honors Program.

10:15 - 10:30 - E2

*Fractional Cycloatom States.  John Henderson, Rainer Grobe and Qichang Su, Illinois State University, Normal, IL 61790-4560. The cycloatom state has been realized classically in the Liouville phase space as well as quantum mechanically by analyzing the solution of the time dependent Schrödinger equation. A simple two-vector diffusion equation has been successful in recovering the ring shaped cycloatom state. To understand the more complicated circumstances when cyclotron frequency of the applied magnetic field is only a fraction of the laser frequency we systematically analyze the effect of (a) kinematic relativity, (b) the magnetic component of the laser field, and (c) the electric component of the laser field on the fractional cycloatom resonance. [1] The understanding here is crucial in generalizing the model to two electron systems and making better suggestions for any experimental verifications. [2] * Supported by grants of the NSF, Research Corporation, Illinois State URG and Honors Program. [1] R. E. Wagner, S. Radovich, J. Gillespie, Q. Su and R. Grobe, Phy. Rev. A 66, 043412 (2002). also published in Virtual Journal of Ultrafast Science, Vol.1 Issue 6, November 2002. [2] H. Henderson, T. Faust, Q. Su and R. Grobe, in preparation.

10:30 - 10:45 - E3

*Ionization and Stabilitzation of Atoms in Magnetic Fields. Travis Faust, Rainer Grobe and Qichang Su, Illinois State University, Normal, IL 61790-4560. Using a Monte Carlo approach we study the laser field induced ionization of hydrogen atoms in very intense static magnetic fields. [1] Compared to the zero-magnetic field case, we find an increase or decrease of the total ionization probability depending on the strength of the magnetic field and the details of how the atom is subjected to the magnetic field. This is part of our systematic investigations of atomic stabilization in the absence of strong magnetic field and the resonant states in the presence of strong magnetic fields which have been carried out previously. * Supported by grants of the NSF, Research Corporation, Illinois State URG and Honors Program. [1] R.E. Wagner, Q. Su and R. Grobe, Laser Phys., in press.

10:45 - 11:00 - E4

*Laser Propagation in Milk. Michael Bell, Rainer Grobe and Qichang Su, Illinois State University, Normal, IL 61790-4560. We discuss experimental set ups aimed at confirming theoretical predictions of non-diffusive behaviors in light scattering in turbid media such as milk. The propagation of a light pulse in a heterogeneous medium can be modeled by assuming that the laser photons perform random walk type motion. We have developed a Monte-Carlo algorithm [1] to simulate a laser pulse in a time-dependent turbid medium such as milk. The computer simulations are designed to get a better understanding of how spatial in-homogeneities that are embedded inside the milk modify the propagation dynamics and how they can be detected. We focus our attention to the study of the unusual dip in the reflection signal that can not be predicted by the well-known photon diffusion model published in the literature. [2] * Supported by grants of the NSF, Research Corporation, Illinois State URG and Honors Program. [1] For related work see omlc.ogi.edu/software/mc/index.html [2] A.F. Lewis, M.S. Bell, R.E. Wagner, Q. Su and R. Grobe, Laser Phys., in press.