Opening the Gravitational Wave Window
Gabriela Gonzalez, Professor of Physics and Astronomy Louisiana State University and Spokesperson LIGO Scientific Collaboration
Gravitational waves are "ripples in space time'' produced by violent astrophysical events such as core-collapse supernova and collisions of neutron stars and black holes, as well as by other continuous phenomena as rotating stars and the early Universe. These waves have never been directly detected on Earth yet, but a network of ground-based interferometric detectors including the LIGO detectors in the US is expected to do this very soon. These detectors have operated with record sensitivity in the recent past, and are now being upgraded to begin operating with good prospects of observations in a few years. I will present a brief introduction to the nature and detection of gravitational waves, and present the current status of the international network of detectors.
Physics: A Life-Rewarding Career
Denise Caldwell, Division Director for the Physics Division at the National Science Foundation
Each person in the course of his or her undergraduate and graduate studies elects a major subject. The choice of topic is driven by many forces. But at the top of the list should be a liking for the area, a feeling of excitement that comes with just learning the material. The university years are also the time when one secures a solid foundation on which to build a future career. This presentation will make the argument that the study of physics can fulfill both of these requirements. The discipline itself represents one of the most intellectually stimulating explorations a student can undertake. And the rigorous training that physics demands, particularly the approach to problem-solving, prepares the student for multiple choices of career as various opportunities become available over the course of a lifetime. There is a potential future in academia in various settings, in the private sector in industrial laboratories or individual entrepreneurial ventures, in government laboratories engaged in cutting-edge research, in science policy, and in careers outside of physics per se. This combination of intellectual stimulation plus multiple opportunities for professional satisfaction is open to those who are about to take the next step. ______________________________________________________________________________________________________________________________________________________________________
Listening to Einstein's Universe
Katherine Dooley, Assistant Professor of Physics University of Mississippi
Einstein predicted in his Theory of General Relativity that the motion of massive and asymmetric astrophysical objects should generate gravitational waves as they stir up spacetime. Gravitational waves travel at the speed of light, virtually undisturbed by matter. Their effect is an oscillating strain in the curvature of spacetime, which can be observed by making an ultra-high precision measurement of the distance between two inertial masses. The Laser Interferometer Gravitational-wave Observatory (LIGO) has set out to do just that. I will share the story of my path in getting to work on this exciting project and present some new work on using squeezed light to improve the detector's sensitivity to gravitational waves.
Competencies for Success as a Physicist in Industry
Zelda Gills, Lockheed Martin Aeronautics Company
Through telling her personal story, Dr. Gills will share technical and functional soft skills that have given her career resilience and growth in industry. In doing so, she will also elucidate guides to success and make recommendations for preparing for a career in industry.
Iron in the Body
Claudia Hillenbrand, Associate Member of the Department of Radiological Sciences St. Jude Children's Research Hospital and Adjunct Faculty Member of Biomedical Engineering University of Memphis, TN
Iron overload (IO) is a serious medical condition resulting from increased dietary gastro-intestinal iron absorption, multiple blood transfusions, or both. IO in pediatric patients mainly results from repeated blood transfusions. Because there is no physiologic mechanism for iron elimination, signs of IO can be detected after 15–20 transfusions. Excess iron accumulates in nearly all tissues, but most notably in the liver and heart, causing organ dysfunction, substantial morbidity, and increased mortality. Accurate assessment of iron burden is essential to manage IO patients properly by initiating and monitoring iron chelation therapy or therapeutic phlebotomy. The chemical analysis of liver specimens obtained through needle biopsy is the reference method to evaluate iron burden. Liver biopsy is an invasive procedure that carries risks such as pain, bleeding, and infection. Non-invasive methods to estimate IO with magnetic resonance imaging (MRI) as an alternative to biopsies are on the rise. MRI is sensitive to tissue iron concentration because the magnetic properties of iron change the tissue specific transverse relaxation times T2 and T2*. This presentation reviews the etiology of IO, organ involvement, why and how we monitor iron deposition in the body, and specifically the assessment of IO by MRI. It further investigates confounding factors of MR iron quantification, accuracy and precision measurements, and discusses ongoing research to optimize MR data acquisition for accurate iron assessment.
Fun, Family, and Flexibility in Materials Physics
Veerle Keppens, Professor of Materials Science and Engineering and Associate Dean for Faculty Affairs University of Tennessee and Knoxville
Using ultrasound to study basic properties of materials has been the cornerstone of my research efforts over the past 2 decades. However, the technique of choice, the research environment, and the materials to be studied have certainly changed over the years, some more dramatically than others. In this talk, I will address my current research emphasis, while also talking about my -at times unconventional- career path from an undergraduate physics student in Leuven (Belgium) to the associate dean in the college of engineering at The University of Tennessee.
GRADUATE AND UNDERGRADUATE STUDENT TALKS
Acoustical Memory in Lithium Niobate
University of Mississippi
The acoustical memory (AM) effect is observed in a yz cut Lithium niobate (LiNbO3) plate at a frequency of 4.26 MHz. The AM signal consists of a non-exponential echo pattern, in which the echo amplitude decreases at first and then increases at a later time. The internal microstructure of LiNbO3 may be involved in the AM effect. To study the defects in the crystal, photoluminescence spectra are investigated. Photoluminescence spectra are taken from different positions along the z-axis of the sample. Some of the defects like Barium, Iron oxide are not evenly distributed along the z-axis. The location of the defects are in agreement with the frequency at which AM is observed.
Shear Waves in Viscoelastic Wormlike Micellar Fluids
E.G. Sunethra K. Dayavansha
University of Mississippi
Wormlike micellar fluids consist of an aqueous solution of a surfactant and a salt and the surfactant molecules can assume varying topologies depending various physical properties such as temperature and concentration. In this work, the variation of shear speed with temperature of a micellar fluid was studied. The fluid studied here is an aqueous solution of hexadecyltrimethylammonium bromide (CTAB, C19H42BrN) and sodium salicylate (NaSaI) in a 5:3 ratio.This fluid is viscoelastic and can support shear waves to depths of the order of ten centimeters depending on concentration. The shearing of the fluid as the shear wave propagates through the fluid can be observed as a time varying birefringence pattern by using a high speed camera. The variation of shear speed with temperature will be presented.
Suspensions Thermal Propagation Study
Louisiana State University
In order to detect gravitational waves, LIGO detectors are extremely sensitive. A test mass is hanging from blade springs that are so sensitive to heat that a temperature fluctuation of less than a degree could cause the suspension to sag. This could lead to a locking problem and a lock loss. In my talk I will be presenting the study of how temperature change outside the vacuum chamber affects the suspension, and how we could use the suspension itself as an in-chamber temperature indicator since LIGO does not have temperature sensors installed inside every chamber.
Acousto-electric Impedance of Ferroelectric Phonic Superlattice
University of Mississippi
The Ferroelectric Phononic Superlattice (FPS) crystal has a number of important solid-state applications. The acousto-electric impedance, which is a fundamental physics property of FPS under considerations, is an important parameter for acoustical transduction. The results of the theoretical and experimental investigations of Z in a periodically poled LiNbO3 are presented. The findings may be used for developing new acoustic sensors and transducers.
Computing of Ultrasonic Pressure Fields in Feline Brain
University of Mississippi
The overall goal of this project is to determine the actual acoustic pressure present during experiments performed in the brains of anesthetized cats. The project involved calculation of the acoustic pressure waveform in cat brain produced by a spherically focused transducer given the source pressure amplitude,frequency,transducer diameter and focal length. For low source pressure,the focal intensity is matched to experimentally determined values,and the computed wave forms are the same as those determined using linear theory. For higher source pressures,the intensities may still match,but the pressure waveforms must be computed using nonlinear theory.
Radiated Quantities in Binary Black Hole Collisions
Lorena Magana Zertuche, James Healy, Deirdre Shoemaker
Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology, USA
One of the more interesting and exotic systems in the universe is a system of two black holes. Once black holes start to orbit each other, they will collide, forming a single black hole with a mass almost equal to the sum of the two initial masses. This missing “mass,” up to ten percent, is converted into gravitational waves making these systems one of the most energetic in the universe. I present work toward modeling the radiated energy as functions of the binary system’s initial parameters for generic binaries in precessing and non-precessing systems.