Each Spring, the department of Physics & Astronomy holds its Undergraduate Research Symposium. Our students get to show off what they have been doing in the lab for the past year. The event will be held this year on Saturday March 26 in the nTelos Room in the ISAT building. The symposium will feature 10 student talks. This year's keynote speaker is Andy Royston of Texas A&M University. Below is the program for the 2016 research symposium.
This research is a further investigation into the interaction between Infrared Radiation and matter with the main goal being new energy sources. Specifically, looking into the effect on standard capacitors and comparing results with the findings of our Thermal Electric device (TEC). The results support the assertion of previous research that the TEC behaves like a capacitor with a certain capacitance.
We research methods to harvest energy from Infrared radiation and transform it into usable electricity. In particular, infrared light incident on a capacitor conveys energy to it, and we are investigating the mechanism of this process. In my presentation, I will focus on our studies aiming to describe how infrared light displaces the charge density on the capacitor.
Weakness in intrinsic foot muscles (IFM) has been associated with development of foot deformities, plantar fasciitis, ulceration, and difficulty with balance and falls. Current techniques characterize IFM using flexion measurements, but functions and activation of entire IFM muscle groups have not been investigated in depth partially due to challenges in measuring muscle strength during toe abduction. To overcome this obstacle, we investigate the use of Polydimethylsiloxane (PDMS) gels as a suitable force transducer for characterization of IFM. For this purpose, soft solid gels are prepared by mixing commercially available PDMS precursors, at appropriate ratios, together with sub-millimeter glass particles. The mechanical properties of the gel, including its elastic modulus, are then characterized by precisely tracking the particles embedded in the gel during controlled mechanical deformation. Finally, the same image analysis method is used to measure pressure and stress during toe abduction while simultaneously measuring IFM activation using electromyography. Preliminary results show the technique to be very promising to probe new aspects of IFM functions/activation, which can directly lead to the development of strengthening techniques to improve function, prevent injury, and enhance performance. This project is a collaborative effort between the animal movement lab in Biology and the soft complex materials lab in Physics and Astronomy.
The anomalous magnetic moment of the muon is a quantity that can be calculated rigorously through the given parameters of the Standard Model. The experimental value is slightly off from the theoretical value and thus suggesting that the Standard Model is not completely correct and most likely needs to be modified. The measurement of the g of the muon has been done before at Brookhaven, NY and at LHC, but at Fermilab a repeat of the Brookhaven E821 experiment is being done with a greater care for detail and thus will get a more precise measurement. The new experiment at Fermilab is expected to get a value of g of the muon to 0.14 ppm. The signal amplification circuitry for the calorimeter is powered by the Low Voltage Power Supply box, a small component of the calorimeter cart. The main focus of our team is to design and construct the Low Voltage Power Supplies. Currently, the basic power supplies have been decided on and the rack mount box itself is in the development process. The power supplies are to feature a current readout and indicator lights for each of the power supplies. Furthermore, the boxes are to be designed as per the Fermilab safety requirements.
We examine a bubble raft system of soap bubbles floating on water with which a normal stress is applied from two plates. The bubbles in this system can deform and translate while the system oscillates. We examine the force network of this system. In particular, we analyze the orientation and deformation of these bubbles to understand how stress is distributed throughout the oscillation. While the system is at its most relaxed, the bubbles form an isotropic distribution of stress. As the system is compressed, the bubbles form a nonisotropic stress distribution with a semi-major axis most often occurring at 90 degrees.
Galaxy interactions are ubiquitous and are believed to play a pivotal role in the formation and evolution of galaxies via facilitating gas inflows toward the central region of galaxies. These interactions are expected to trigger accretion of matter onto the central supermassive black holes, i.e., AGN activity. Nevertheless, despite decades of searching, observationally confirmed dual AGNs remain extremely rare. We present here a thorough near-infrared characterization of six examples of interacting galaxies with unambiguous confirmation of on-going mergers that are optically quiescent but have red mid-infrared colors that are associated with extragalactic sources with powerful AGN. We show Large Binocular Telescope spectra of nuclear regions that reveal a rich variety of emission and absorption features which allow us to explore several diagnostic tests for the AGN activity as well as for properties of the underlying stellar population. We find strong evidence for AGN emission in five out of these six interacting systems, which provides strong support for the efficiency with which the mid-infrared pre-selection technique finds dual AGN, and thus could exponentially increase the population of dual accretion systems in advanced mergers.
Water megamaser disks detected in 22 GHz emission in galactic nuclear regions provide direct geometrical distances to galaxies and the most precise and accurate masses of supermassive black holes. Nevertheless, these systems are extremely rare. Improvements on their detection rates in future surveys rely on better understanding of their physical properties, in relation to those of their host galaxies. There is tentative evidence that the disk masing conditions are associated with accretion of matter onto supermassive black holes, which is usually detected as active galactic nucleus activity. In particular, megamaser disk emission appears to be associated with the active galactic nuclei that are obscured by cosmic dust in their host galaxies’ circumnuclear regions. Using data from the Wide-Field Infrared Survey Explorer we systematically study the mid-IR properties of the galaxies with and without nuclear water maser emission to better constrain the connection between water masing activity and the circumnuclear dust absorption and radiation reprocessing in galaxy centers.
Extrasolar planets, more commonly referred to as exoplanets, are planets that orbit stars other than the Sun. The sizes and compositions of these objects range from rocky Earth-like terrestrials to cloudy Jupiter-like gas giants. Since the first confirmed discovery of an exoplanet in 1992, space missions such as the Kepler Space Telescope and the Wide-Field InfraRed Survey Telescope (WFIRST) have successfully detected thousands of these exoplanets with more planetary systems being confirmed every day. There exists a variety of techniques for detecting extrasolar planets around their host stars, one of which is to study the effect of the planet on the total emission spectra and flux from the star-planet system. Specifically, due to their small sizes and low temperatures compared to their host stars, the exoplanets emit thermal radiation measured in the near- or far-infrared wavelengths. To model this thermal emission from the exoplanets, simple custom codes were developed using MATLAB R2016b programming software. Certain parameters for the star and planet are chosen and inputted by the user, including the temperature, apparent magnitude, and distance to the star as well as the semi-major axis, phase, and inclination angle of the planet and its orbit. The code then determines the average temperature of the planet, its day-side and night-side temperatures, and its resulting level of thermal emission, and then generates plots of the blackbody radiation and flux produced by the system. We present here our preliminary results, with multiple assumptions and constraints placed on our models for simplification. Our goal is to modify the MATLAB codes to be able to handle more advanced physics by implementing more complicated parameters such as the rotation and atmosphere of the planet or the period and location of the planet in its orbit.
We will discuss the dimensional reduction of anomalies in Conformal Field Theory. A Conformal Field Theory is a field theory that is invariant under a group of coordinate transformations called conformal transformations. An anomaly in such a theory is the violation of a classical symmetry due to quantum effects. We study the mode expansions of relevant operators, and the quantum mechanics of the coefficients in the mode expansions, as a first step in learning more about anomalies that occur in the CFTs we consider.
Congratulations to the 2014 graduating class! This year, the Department graduated 20 physics majors. JMU's Department of Physics & Astronomy remains as one of the top 5 primarily undergraduate programs in the country in terms of physics graduates. Some pictures from the May 10th College of Science and Mathematics Graduation are shown below.
Each year in the Spring semester, JMU honors its top performing students at the annual Honors Banquet. The department recognizes its Outstanding Senior and Junior, and the outstanding Research, Departmental Service, Planetarium Service and Teaching awards. Several scholarships available in the department are awarded and the department inducts its newest members into the JMU chapter of the physics honor society, Sigma Pi Sigma. The department also presents First, Second, and Third prizes for the best talks from its Spring undergraduate research symposium.