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Home / Undergraduate Research Highlights / Physics / Astronomy
 
Physics and Astronomy Highlights
Total Listing: 117    (Listed by the order of record adding time, Descending)
( 1 )   Recorded at: 1/13/2010      
Title Electron Affinity of Arsenic and the Fine Structure of As^– Measured using Infrared Threshold Photodetachment Spectroscopy
Journal Phys Rev A., 2009;80:014501-1 - 014501-4, Walter CW, Gibson ND, Field RL, Snedden AP, Shapiro JZ, Janczak CM, Hanstorp D.
Description This article reports an experimental study of the negative ion of arsenic, i.e. an arsenic atom with one additional electron attached to it. We used a variable wavelength laser to measure the minimum energy required to detach the added electron from the negative ion, thus determining how strongly arsenic binds electrons. Our measurement improved the accuracy of the electron affinity of arsenic by a factor 40 over the previous best measurement, thus providing precise information for this fundamental thermochemical property. Our results will be of use for testing state-of-the-art atomic structure theories and for controlling chemical reactions involving arsenic.
Faculty Wes Walter and Dan Gibson are professors of physics. Prof. Dag Hanstorp from Gothenburg University, Sweden, participated in the project as a visitor to our lab.
Student Four undergraduate students participated in the research over the summers of 2007 and 2008: Richard Field, Ali Snedden, Jacob Shapiro, and Corey Janczak. Richard and Ali are now in graduate school in physics at the Univ. of Michigan and Univ. of Notre Dame, respectively, Jacob is a senior double-majoring in physics, and Corey is employed after graduating with a physics major.
Fund The research was supported by grants from the National Science Foundation and by Denison University’s Anderson Summer Research and Bowen Funds, which provided some student summer stipends; Prof. Hanstorp received support from the Swedish Research Council and Denison University.
 
( 2 )   Recorded at: 12/16/2009      
Title The peculiar periodic YSO WL 4 in Rho Ophiuchus
Journal The Astrophysical Journal, 2008;684(1):L37-L40, Plavchan P, Gee AH, Stapelfeldt K, Becker A
Description We present the discovery of 131-day periodic near-infrared flux variability for the Class II T Tauri star WL 4. Our data are from the 2MASS Calibration Point Source Working Database and constitute 1580 observations in J, H, and Ks of a field in Rho Ophiuchus used to calibrate the 2MASS All-Sky Survey. We identify a light curve for WL 4 with eclipse amplitudes of ~0.4 mag lasting more than one-quarter the period and color variations in J-H and H-Ks of ~0.1 mag. We propose that WL 4 is a triple YSO system, with an inner binary orbital period of 131 days. We postulate that we are observing each component of the inner binary alternately being eclipsed by a circumbinary disk with respect to our line of sight. This system will be useful in investigating terrestrial-zone YSO disk properties and dynamics at ~1 Myr
Faculty Peter Plavchan is a Staff Scientist at the new NASA Exoplanet Science Institute at Caltech
Student Alan Gee is currently a junior undergraduate at Caltech, and participated in this research as part of the Summer Undergraduate Research Program at Caltech after his freshman year in 2007. Parts of the research described in this publication were carried out at JPL
 
( 3 )   Recorded at: 12/7/2009      
Title Influence of architecture, concentration, and thermal history on the poling of nonlinear optical chromophores in block copolymer domains
Journal Macromolecules, 2008;41:4651-4660, Leolukman M, Paoprasert P, Wang Y, Makhija V, McGee DJ, Gopalan P
Description Factors affecting the electric-field-induced poling of nonlinear optical chromophores in block copolymer domains were investigated by encapsulating the chromophores in a linear-diblock copolymer and linear-dendritic block copolymer via hydrogen bonding. Chromophore encapsulation in the majority domain produced the most favorable conditions for poling as measured by in situ second harmonic generation. It was also observed that the linear-dendron/chromophore system presented the most effective architecture for spatially dispersing chromophores, suggesting that polymer chains end functionalized with chromophores is an effective approach for maximizing nonlinear optical activity
Faculty David McGee is professor of physics at Drew University and a former CUR councilor. Padma Gopalan is a professor of materials science and engineering at UW-Madison
Student Varun Makhija was a physics undergraduate at Drew whose independent study and honors thesis work formed the basis for this publication. He is now a graduate student at Kansas State University. Melvina Leolukman, Peerasak Paoprasert, and Yao Wang are graduate students at the University of Wisconsin-Madison
Fund This work was supported by the Drew Summer Science Institute and an NSF-RUI grant from the Division of Materials Research
 
( 4 )   Recorded at: 12/7/2009      
Title Anticorrelated electrons from weak recollisions in non-sequential double ionization
Journal J Phys B: At Mol Opt Phys, 2008;41:211002, Haan SL, Smith ZS, Shomsky KN, and Plantinga PW
Description This work used 3d classical modeling to examine double ionization in helium by lasers. It considered the question of how ionization at intensities below the so-called “recollision threshold” could produce electron pairs that travel in opposite directions from each other. The study revealed that the laser would ionize one electron, then impel it back to the core to form a doubly excited state from which electrons ionized sequentially
Faculty Stan Haan is a Professor of Physics
Student Zach Smith is a senior physics major, presently applying to graduate schools in physics. Katie Shomsky a junior, and Peter Plantinga a sophomore
Fund Work was supported by a National Science Foundation RUI award (Grant No. 0653526) and by the Calvin College Physics and Astronomy Department. It was all performed in summer 2008 and published as a Fast Track Communication
 
( 5 )   Recorded at: 12/7/2009      
Title The LSC glitch group: monitoring noise transients during the fifth LIGO science run
Journal Classical Quantum Gravity, 2008;25(18):184004, Blackburn L, Caride S, Christensen N, Ely G, Isogai T, et al
Description Goals of the glitch group during the fifth LIGO science run (S5) included (1) offline assessment of the detector data quality, with focus on noise transients, (2) veto recommendations for astrophysical analysis and (3) feedback to the commissioning team on anomalies seen in gravitational wave and auxiliary data channels. Other activities included the study of auto-correlation of triggers from burst searches, stationarity of the detector noise and veto studies. The group identified causes for several noise transients that triggered false alarms in the gravitational wave searches; the times of such transients were identified and vetoed from the data generating the LSC astrophysical results
Faculty Nelson Christensen is a Professor of Physics at Carleton College
Student Santiago Caride and Gregory Ely were undergraduate physics majors who worked on the NSF funded research from 2005-2008. Santiago is currently a graduate student in physics at the University of Michigan and Gregory is currently employed at Lincoln Laboratory, MIT. Tomoki Isogai is currently an undergraduate physics major at Carleton who worked on the study in 2007-2008
 
( 6 )   Recorded at: 12/7/2009      
Title All-sky search for periodic gravitational waves in LIGO S4 data
Journal Phys Rev D, 2008;77:022001, Abbott B, Bantilan H, Christensen N, et al
Description The study reports on an all-sky search with the LIGO detectors for periodic gravitational waves in the frequency range 50-1000 Hz and with the frequency's time derivative in the range -1.0E-8 Hz/s to zero. Data from the fourth LIGO science run (S4) were used in this search. Three different semicoherent methods of transforming and summing strain power from Short Fourier Transforms (SFTs) of the calibrated data have been used, known as StackSlide, “weighted Hough” scheme, and PowerFlux. The respective advantages and disadvantages of these methods are discussed. Observing no evidence of periodic gravitational radiation, we report upper limits; we interpret these as limits on this radiation from isolated rotating neutron stars. The best population-based upper limit with 95% confidence on the gravitational-wave strain amplitude, found for simulated sources distributed isotropically across the sky and with isotropically distributed spin-axes, is 4.28E-24 (near 140 Hz). Strict upper limits are also obtained for small patches on the sky for best-case and worst-case inclinations of the spin axes
Faculty Nelson Christensen is a Professor of Physics at Carleton College
Student B. Hans Bantilan was an undergraduate mathematics and physics major who worked on the project during the academic terms and summers from 2004-2007. He is currently a graduate student in physics at Princeton
Fund The research was supported by a grant from NSF
 
( 7 )   Recorded at: 12/7/2009      
Title Beating the spin-down limit on gravitational wave emission from the Crab pulsar
Journal Astrophys J Lett, 2008;683;49, Abbott B, Bantilan H, Christensen N, et al
Description The paper presents direct upper limits on gravitational wave emission from the Crab pulsar using data from the first 9 months of the fifth science run of the Laser Interferometer Gravitational-wave Observatory (LIGO). These limits are based on two searches. In the first we assumed that the gravitational wave emission follows the observed radio timing, giving an upper limit on gravitational wave emission that beats indirect limits inferred from the spin-down and braking index of the pulsar and the energetics of the nebula. In the second we allowed for a small mismatch between the gravitational and radio signal frequencies and interpret our results in the context of two possible gravitational wave emission mechanisms
Faculty Nelson Christensen is a Professor of Physics at Carleton College
Student Hans Bantilan was an undergraduate mathematics and physics major who worked on the project during the academic terms and summers from 2004-2007. He is currently a graduate student in physics at Princeton
Fund The research was supported by a grant from NSF
 
( 8 )   Recorded at: 12/7/2009      
Title Search of S3 LIGO data for gravitational wave signals from spinning black hole and neutron star binary inspirals
Journal Phys Rev D, 2008;78:042002, Abbott B, Bantilan H, Christensen N, et al
Description This paper reported on the methods and results of the first dedicated search for gravitational waves emitted during the inspiral of compact binaries with spinning component bodies. We analyze 788 hours of data collected during the third science run (S3) of the LIGO detectors. We searched for binary systems using a detection template family specially designed to capture the effects of the spin-induced precession of the orbital plane. We present details of the techniques developed to enable this search for spin-modulated gravitational waves, highlighting the differences between this and other recent searches for binaries with non-spinning components
Faculty Nelson Christensen is a Professor of Physics at Carleton College
Student Hans Bantilan was an undergraduate mathematics and physics major who worked on the project during the academic terms and summers from 2004-2007. He is currently a graduate student in physics at Princeton
Fund The research was supported by a grant from NSF
 
( 9 )   Recorded at: 12/7/2009      
Title Implications for the origin of GRB 070201 from LIGO observations
Journal Astrophys J, 2008;681:1419, Abbott B, Bantilan H, Christensen N, et al
Description We analyzed the available LIGO data coincident with GRB 070201, a short-duration, hard-spectrum gamma-ray burst (GRB) whose electromagnetically determined sky position is coincident with the spiral arms of the Andromeda galaxy (M31). Possible progenitors of such short, hard GRBs include mergers of neutron stars or a neutron star and a black hole, or soft gamma-ray repeater (SGR) flares. These events can be accompanied by gravitational-wave emission. No plausible gravitational-wave candidates were found within a 180 s long window around the time of GRB 070201
Faculty Nelson Christensen is a Professor of Physics at Carleton College
Student Hans Bantilan was an undergraduate mathematics and physics major who worked on the project during the academic terms and summers from 2004-2007. He is currently a graduate student in physics at PrincetonThe research was supported by a grant from NSF
 
( 10 )   Recorded at: 12/7/2009      
Title Search for gravitational waves associated with 39 gamma-ray bursts using data from the second, third, and fourth LIGO runs
Journal Phys Rev D, 2008;77:062004, Abbott B, Bantilan H, Christensen N, et al
Description We present the results of a search for short-duration gravitational-wave bursts associated with 39 gamma-ray bursts (GRBs) detected by gamma-ray satellite experiments during LIGO's S2, S3, and S4 science runs. The search involves calculating the cross correlation between two interferometer data streams surrounding the GRB trigger time. We search for associated gravitational radiation from single GRBs, and also apply statistical tests to search for a gravitational-wave signature associated with the whole sample. For the sample examined, we find no evidence for the association of gravitational radiation with GRBs, either on a single-GRB basis or on a statistical basis. Finally, we discuss prospects for the search sensitivity for the ongoing S5 run, and beyond for the next generation of detectors
Faculty Nelson Christensen is a Professor of Physics at Carleton College
Student Hans Bantilan was an undergraduate mathematics and physics major who worked on the project during the academic terms and summers from 2004-2007. He is currently a graduate student in physics at Princeton
Fund The research was supported by a grant from NSF
 
( 11 )   Recorded at: 12/7/2009      
Title Search for gravitational waves from binary inspirals in S3 and S4 LIGO data
Journal Phys Rev D, 2008;77:062002, Abbott B, Bantilan H, Christensen N, et al
Description This study reported on a search for gravitational waves from the coalescence of compact binaries during the third and fourth LIGO science runs. The search focused on gravitational waves generated during the inspiral phase of the binary evolution. We considered three categories of compact binary systems, ordered by mass. Although the detectors could probe to distances as far as tens of Mpc, no gravitational-wave signals were identified in the 1364 hours of data we analyzed. Assuming a binary population with a Gaussian distribution around 0.75 - 0.75M center dot, 1.4 - 1.4M center dot, and 5.0 - 5.0M center dot, we derived 90%- confidence upper limit rates of 4.9 yr(-1)L(10)(-1) for primordial black hole binaries, 1.2 yr(-1)L(10)(-1) for binary neutron stars, and 0: 5 yr(-1)L(10)(-1) for stellar mass binary black holes, where L-10 is 10(10) times the blue-light luminosity of the Sun
Faculty Nelson Christensen is a Professor of Physics at Carleton College
Student Hans Bantilan was an undergraduate mathematics and physics major who worked on the project during the academic terms and summers from 2004-2007. He is currently a graduate student in physics at Princeton
Fund The research was supported by a grant from NSF
 
( 12 )   Recorded at: 12/7/2009      
Title Einstein@Home search for periodic gravitational waves in LIGO S4 data
Journal Phys Rev D, 2008:http://arxiv.org/abs/0804.1747, Abbott B, Bantilan H, Christensen N, Ely G, Vigeland S, et al
Description A search for periodic gravitational waves, from sources such as isolated rapidly-spinning neutron stars, was carried out using 510 hours of data from the fourth LIGO science run (S4). The search was for quasi-monochromatic waves in the frequency range from 50 Hz to 1500 Hz, with a linear frequency drift f-dot (measured at the solar system barycenter) in the range -f/tau < f-dot < 0.1 f/tau, where the minimum spin-down age tau was 1000 years for signals below 300 Hz and 10000 years above 300 Hz. The main computational work of the search was distributed over approximately 100000 computers volunteered by the general public. This large computing power allowed the use of a relatively long coherent integration time of 30 hours, despite the large parameter space searched. No statistically significant signals were found. The sensitivity of the search is estimated, along with the fraction of parameter space that was vetoed because of contamination by instrumental artifacts. In the 100 Hz to 200 Hz band, more than 90% of sources with dimensionless gravitational wave strain amplitude greater than 1e-23 would have been detectedNelson Christensen is a Professor of Physics at Carleton College
Faculty Hans Bantilan, Sarah Vigeland, and Gregory Ely were undergraduate students who worked on the NSF funded research during the academic year and summers from 2004-2008. Hans is currently a graduate student in physics at Princeton, Sarah is currently a graduate student in physics at MIT, and Gregory is currently employed at Lincoln Laboratory, MIT
Student
 
( 13 )   Recorded at: 12/7/2009      
Title Electrodynamics on the grid
Journal Am J Phys, 2008;76:464-469, Sipos M, Thompson B
Description Maxwell's curl equations lead to energy transport via electric and magnetic fields because spatial variations of one field lead to a temporal change in the other. The finite difference time domain method of calculating electromagnetic fields takes advantage of the interplay of the fields by using a suitable grid and time stepping method. The method is simple and instructive for understanding the genesis of electromagnetic transport phenomena. Reflection, refraction, interference, and diffraction result directly from the linked first-order derivatives of the fields. Extension of the method to include permittivity and permeability tensors with extreme values of these properties allows a wave to be bent around a central region thus cloaking (rendering invisible) any object inside
Faculty Bruce Thompson is an associate professor of physics at Ithaca College
Student Maksim Sipos was an Ithaca College Dana Research Fellow during the 2007-2008 academic year when he worked on this project. He is currently a graduate student in physics at the University of Illinois Urbana-Champaign
 
( 14 )   Recorded at: 12/7/2009      
Title Soil hydraulic properties influenced by agroforestry and grass buffers for grazed pasture systems
Journal J. Soil Water Conserv, 2008;63:224-232, Kumar S, Anderson SH, Bricknell LG, Udawatta RP, Gantzer CJ
Description The project study evaluated soil hydraulic properties as affected by agroforestry and grass buffers compared to rotationally and continuously grazed pasture systems. Saturated hydraulic conductivity values for buffer treatments were over 15 times higher compared to values in grazed pastures. These differences were attributed to a larger amount of soil macropores (> 1 mm diam.) present in the buffers. Agroforestry and grass buffers maintained higher values for the selected soil hydraulic properties compared to grazed pasture systems
Faculty Steve Anderson is a professor of environmental soil physics in the Department of Soil, Environmental and Atmospheric Sciences at the University of Missouri
Student Laura Bricknell, senior environmental science major, participated in the study while pursuing a research internship during the summer of 2006. Laura was employed as a research assistant by the University of Missouri Center for Agroforestry which also supported the research study. Laura is currently a Soil Scientist working for the USDA-Natural Resources Conservation Service in Hayes, Kansas
 
( 15 )   Recorded at: 12/7/2009      
Title Recollision excitation, electron correlation, and the production of high-momentum electrons in double ionization
Journal Phys Rev Lett, 2008;101:113001, Haan SL, Smith ZS, and VanDyke JS
Description This work used 3d classical modeling to consider the production of high-momentum electrons in double ionization. It revealed that the laser would ionize one electron, then propel it back to the core where collision would result in one electron free and the other in a highly excited state, from which it would subsequently ionize. The highest momentum electrons were formed by scattering of the free electron off the nucleus
Faculty Stan Haan is a Professor of Physics
Student Zach Smith is a senior physics major, presently applying to graduate schools. John VanDyke is an ’08 graduate with majors in physics and philosophy, presently attending graduate school in philosophy. Zach and John worked fulltime on the project in summer 2007, and part-time through the academic year
Fund The work was supported by a National Science Foundation RUI award (Grant No. 0653526).
 
( 16 )   Recorded at: 12/7/2009      
Title PAH emission from Herbig Ae/Be stars
Journal Astrophysical Journal, 2008;684:411- 430, Keller LD, Sloan GC, Forrest WJ, Ayala S, D’Alessio P, Shah S, Calvet N, Hartmann L, Najita J, Sargent B, Li A, Watson DM, Chen CH
Description Over half of the intermediate-mass young stars in the Milky Way Galaxy (e.g. Herbig Ae/Be stars or HAeBe) have high-contrast emission in the mid-infrared spectral features of polycyclic aromatic hydrocarbons (PAHs) above the continuum produced by thermal emission from dust in the circumstellar disks. In this paper we examined the PAH emission in detail for 30 HAeBe stars observed with the Spitzer Space Telescope. We identified some trends that will allow us to infer large-scale disk geometry and the degree of photo-processing of organic molecular material by starlight illuminating HAeBe disks. These disks of dusty material, which surround the stars, are the material from which planets may be forming or may already have formed
Faculty Luke Keller is an assistant professor of physics at Ithaca College
Student Sweta Shah participated in the research as a summer intern before she graduated from Ithaca College with a BA in physics (2007). Sweta is currently a graduate student in astronomy at Leiden University, The Netherlands
Fund The research was supported by a grant from Research Corporation and by an Ithaca College Dana Internship award to Sweta Shah
 
( 17 )   Recorded at: 11/24/2009      
Title The elusive memristor: properties of basic electrical circuits
Journal Eur. J. Phys, 2009; 30: 661-675, Joglekar YN and Wolf SJ
Description The project focused on properties of the long-elusive and recently discovered memristor, the forth basic circuit element that complements a resistor, a capacitor, and an inductor. We theoretically and numerically investigated properties of electrical circuits with a memristor, and showed how its nontrivial characteristics are determined by the dynamics of dopant ions inside it. (According to the Publishing Editor for the Journal, this paper was downloaded 250 times in 20 days from the date of its publication.)
Faculty Yogesh Joglekar is an assistant professor of physics at IUPUI.
Student Stephen Wolf is an undergraduate student in electrical engineering at Purdue University. He was an IUPUI UROP Summer Fellow in 2008.
Fund This research was supported by IUPUI UROP (SJW) and by the Aspen Center for Physics (YNJ).
 
( 18 )   Recorded at: 9/14/2009      
Title Ultrasonic characterization of human cancellous bone in vitro using three different apparent backscatter parameters in the frequency range 0.6-15.0 MHz
Journal IEEE Trans. on Ultrasonics, Ferroelectrics, and Frequency Control, 2008;55:1442-1452, Hoffmeister BK, Johnson DB, Janeski JA, Keedy DA, Steinert BW, Viano AM, Kaste SC
Description This study correlates new ultrasonic backscatter measurements of human bone with the density and mechanical properties of bone. The goal is to develop new ultrasonic techniques for diagnosing bone diseases such as osteoporosis. Good correlations were obtained for all three ultrasonic measurements for specific frequency ranges
Faculty Brent Hoffmeister and Ann Viano are associate professors of physics
Student Sue Kaste, D.O. is a full member of the Department of Radiological Sciences at St. Jude Children’s Research Hospital. David Johnson, a double major in physics and biology, participated in this work as a senior honors project. Daniel Keedy, a biology major, John Janeski, a physics major, and Brian Steinert, a physics-biology bridge major, also participated for independent study credit and as summer researchers. David is currently a medical student at Vanderbilt University. Daniel is currently a graduate student in biochemistry at Duke University. John is pursuing a Ph.D. in mechanical engineering at Virginia Polytechnic Institute and State University, and Brian has received an MS degree from the department of materials science and engineering at the University of Alabama at Birmingham
Fund The research was conducted in 2005-2007 and supported in part by a Major Research Instrumentation grant from the National Science Foundation
 
( 19 )   Recorded at: 9/11/2009      
Title PALASS: A portable application for a location-aware social system
Journal Lect. Notes Comput. Sc, 2008;5333:499–508, Press MT, Goodwin D, Flores RA
Description Our paper presents PALASS, a location-aware framework for portable hand-held devices in the Google Android platform. PALASS was developed as a web service application supporting a social dimension where events are shared among users of social groups. In this framework, a web portal centralizes the registration and communication of events, which are displayed using maps in Android-enabled hand-held devices according to the group affiliation of its users. The framework defines user roles, each with clearly defined tasks and functionalities in their groups that simplify the overall organization and management of information
Faculty Both of these students developed PALASS for their Senior Capstone project under the supervision of Roberto Flores, who is an Assistant Professor of Computer Science at CNU
Student Martin Press is a senior at Christopher Newport University and has been accepted to CNU's graduate program in Computer Science. Daniel Goodwin is a CNU alumni and currently works as an IT software developer
Fund Funding for the project was provided by the Department of Physics, Computer Science & Engineering at CNU
 
( 20 )   Recorded at: 9/11/2009      
Title Programmable logic arrays in single-electron transistor technology
Journal International Conference on Signals and Electronic Systems, September 2008; 81-84. ISBN 978-83-88309-47-2. IEEE Catalog Number CFP0857D-PRT, Gerousis CP, Grepiotis AT
Description The goal of this work was to investigate the use of nano-electronic transistors in Programmable Logic Arrays suitable for implementing ultra-dense and ultra low-power architectures. It is currently predicted that semiconductor device scaling will end at the 22-nm device feature size (7 nm physical channel length) according to the International Technology Roadmap for Semiconductors. The main challenge is then to develop innovative technologies that will extend the scaling beyond roadmap projection. Nano-electronics will become an appealing option for developing devices for integrated circuits with dimensions and performances well beyond roadmap predictions
Faculty C. Gerousis is an Associate Professor in the Department of Physics, Computer Science and Engineering (PCSE) at Christopher Newport University (CNU), Newport News, VA.
Student Arthur Thomas Grepiotis was a student is the department of PCSE at CNU majoring in computer engineering (CE). He participated in this research for the CE capstone project credit. Arthur is currently employed as a software engineer
 
( 21 )   Recorded at: 9/11/2009      
Title Permutation Codes
Journal Proceedings of the Midstates Conference for Undergraduate Research in Computer Science and Mathematics, 2008;44-50, Eteri Svanidze, Meral Arnavut
Description Data storage is one of the most concerning issues nowadays with an increasing dependence on real-time data accessibility and availability. Data compression is used to reduce size of documents, data and images so that the amount of time and cost necessary for transmitting the data is smaller. A possible way to compress given data is to use permutation codes. In this work, we study perfect codes since they may yield relatively good data compression when permutation codes are used
Faculty Meral Arnavut, Associate Professor, SUNY Fredonia, Department of Mathematical Sciences
Student Eteri Svanidze is currently a senior student at SUNY Fredonia, graduating in May 2009 with double majors in math and physics. She is applying to graduate schools for her future studies. Eteri participated in this project as Honor Thesis
Fund The SUNY Fredonia, OSCAR travel funding was used to support Eteri Svanidze’s travel to the College of Wooster in Ohio for the Midwest Conference in Undergraduate Research in Computer Science and Mathematics
 
( 22 )   Recorded at: 9/11/2009      
Title Electromagnetically induced transparency in rubidium
Journal Am J Phys, 2009;77:116-121, Olson AJ, Mayer SK
Description This work describes the theory and experiment for investigating ladder-type electromagnetically induced transparency (EIT) in rubidium gas. In EIT, the absorption of a weak, resonant laser field can be reduced due to the presence of a strong, non-resonant laser field, provided the fields are coherently coupled by a common state. Because EIT provides for active control of the response a medium has to resonant light, it offers a unique means of coherently controlling photons and holds great promise for fields such as quantum computing and telecommunications. In this experiment, the theoretical absorption profile of a weak probe laser beam at 780.2 nm (5S1/2 ? 5P3/2) is modeled in the presence of a strong pump laser beam at 776.0 nm (5P3/2 ? 5D3/2) and the absorption transparency window is characterized. Using two grating-feedback diode lasers, EIT is observed experimentally in rubidium and the results are compared to the theory. This experiment, published in the American Journal of Physics, brings the contemporary field of quantum optics into the advanced undergraduate laboratory
Faculty Shannon Mayer is an associate professor of physics at the University of Portland
Student Abraham Olson completed this research for his senior thesis in physics while he was an undergraduate student at the University of Portland. Abraham is now a Ph.D. student in the Department of Physics at Purdue University
Fund The research was supported by the M. J. Murdock Charitable Trust
 
( 23 )   Recorded at: 1/6/2009      
Title A discourse on Mary
Journal Prolegomena, 2007:11, Sayball, M
Description This study examines a problem in the philosophy of mind that argues against a classical thought-experiment in philosophy of mind which attempts to prove that physicalism, the view that complete knowledge of the physical aspects of the world is equivalent to complete knowledge of the world, and that there is nothing which is non-physical. Matt argues that this thought-experiment is not conclusive, and does not disprove physicalism. Mary would not have complete knowledge of the world, because she would lack knowledge of what colors looked like
Faculty The research was begun at UNCW in as an independent research project in philosophy directed by Dr. Ferenc Altrichter
Student Matt's work in logic and semantics was highlighted in the Spring 2007 UNCW College of Arts & Sciences magazine. He is currently a student in the masters program in philosophy at Virginia Tech, and in the process of applying to Ph.D. programs
 
( 24 )   Recorded at: 1/6/2009      
Title Cosmic-ray-induced ship-effect neutron measurements and implications for cargo scanning at borders
Journal Nucl Instr Meth A, 2008;587:89–100, Kouzes RT, Ely JH, Seifert A, Siciliano ER, Weier DR, Windsorm LK, Woodring ML, Borgardt JD, Buckley E, Flumerfelt E, Oliveri A, Salvitti M
Description Neutron measurements are used as part of the interdiction process for illicit nuclear materials at border crossings. Variation in the low natural neutron background, arising almost entirely from cosmic-ray-induced cascades in the atmosphere and the surrounding environment, can impact the sensitivity of detection systems. One significant source of variation in the observed neutron background is produced by the ‘‘ship effect’’ in large quantities of cargo that transit past detection instruments. This research measured the occurance of ship effect neutrons in various materials. One significant result from this work is the ‘‘neutron shadow shielding’’ effect seen with some low neutron density materials
Faculty Dr. James D Borgardt is an Associate Professor of Physics
Student Elise Buckley, a senior math/secondary education major, Eric Flumerfelt a senior physics major, Anna Oliveri a senior chemistry major, and Matt Salvitti, a senior physics/digital media major participated in the research as a summer internship. All students are entering their senior year at Juniata College
Fund The source of funding for the work was the DOE (Dept of Energy), PNNL (Pacific NW National Laboratories). Matt and Eric received a mini-grant from with The William J. von Liebig Foundation (Juniata College) and Elise and Eric received a mini-grant from the APS-FPS (American Physical Society - Forum on Physics and Society)
 
( 25 )   Recorded at: 1/6/2009      
Title High-resolution polarimetry of Parsamian 21: revealing the structure of an edge-on FUOri disc
Journal MNRAS, 2008;383:1015-1028, Ko'spa'l A', A'braha'm P, Apai D, Ardila DR, Grady CA, Henning Th, Juha'sz A, Miller DW, Moo'r A
Description We present the first high spatial resolution near-infrared direct and polarimetric observations of the young stellar object Parsamian 21, obtained with a high resolution imaging adaptive optics system at the European Southern Observatory's Very Large Telescope. We complemented these measurements with archival infrared observations from the NASA/ESA Hubble Space Telescope, the NASA Spitzer SpaceTelescope and the ESA Infrared Space Observatory. Their main conclusions are: (1) Parsamian 21 is probably an FUOrionis-type object, which is a unique class of about-to-form stars that have flared up by a factor of 40 or more; (2) Parsamian 21 is not associated with any rich cluster of young stars; (3) our measurements reveal a circumstellar envelope, a polar cavity and an edge-on disc; the disc seems to be flat and extends from approximately 48 to 360 astronomical units from the star; (4) Parsamian 21 can be classified as an intermediate-aged object
Faculty
Student Recent UL graduate Wes Miller worked on independent study in 2006-2008 with Dr. Carol Grady, a contractor at NASA Goddard Space Flight Center and UL adjunct in Physics & Astronomy, and astronomers from Hungary, Germany and the US on an investigation of a young stellar object, Parsamian 21, to determine its nature in the context of star and proto-planetary disk formation. Miller subsequently a Fulbright to continue with a year of astronomy research at Konkoly Observatory in Budapest. He was mentored by UL associate professor of astronomy Gerard Williger
Fund The work was funded in part by a NASA Spitzer grant Williger held at Catholic University of America
 
( 26 )   Recorded at: 1/6/2009      
Title Poisson equation for weak gravitational lensing
Journal Phys Rev D, 2008;77:123012, Kling TP, Campbell B
Description This paper examined weak gravitational lensing via the Bianchi identity of general relativity expressed in the Newman & Penrose spin coefficient formalism. The Bianchi identity was shown to provide a Poisson equation for the projected matter density (Ricci curvature) given the observed shear (Weyl curvature)
Faculty Thomas Kling is an associate professor of Physics
Student Bryan Campbell, a 2007 Bridgewater State College graduate in Physics and Philosophy, and a 2006 Bridgewater State College Adrian Tinsley Program Summer Research Grant award winner, participated in deriving the basic equations and integrating them by writing C++ computer code in his summer research and senior thesis. Bryan continued his research after graduation until the paper was submitted in January, 2008. Bryan Campbell will pursue graduate studies in physics at the University of New Hampshire, beginning in the fall of 2008
 
( 27 )   Recorded at: 1/6/2009      
Title Concentration of 137Cs in soil across Nebraska
Journal Health Phys, 2008;94:574-580, Palenksy Weesner A, Fairchild RW
Description Atmospheric nuclear weapons testing from 1945 through 1980 and the Chernobyl accident in 1986 resulted in 137Cs being deposited around the world. Soil samples from across the state of Nebraska were collected and analyzed for the 137Cs activity concentration as a function of depth. Results were consistent with published deposition amounts
Faculty Robert Fairchild is Professor and Chair of Physics at Nebraska Wesleyan University and a Certified Health Physicist.
Student Alexandrea Palensky Weesner conducted this research to complete work started as an independent study project. Alexandrea has completed her Bachelor of Science degree in Physics and a Bachelor of Science degree in Environmental Engineering at Washington University in St. Louis. She is currently employed in St. Louis
Fund The research was supported by the Nebraska Wesleyan University Physics Department
 
( 28 )   Recorded at: 1/6/2009      
Title FUSE observations of the Loop I/local Bubble interaction region
Journal Astrophys J, 2008;681:1310-1317, Sallmen SM, Korpela EK, Yamashita H
Description We used the FUSE (Far Ultraviolet Spectroscopic Explorer) satellite to observe interstellar OVI & CIII emission along two sightlines towards the edge of the interaction zone (IZ) between the Loop I superbubble and the Local Bubble. One sightline was chosen because material in the interaction zone blocks distant emission. Analysis of the results suggests that OVI emission within Loop I arises at interfaces rather than on the near side of the IZ, while the CIII emission likely arises on the near side of the IZ. These results support a model in which the Local Bubble is cooler than the interior of Loop I
Faculty Shauna Sallmen is an associate professor of physics
Student Eric Korpela is a research astronomer at the Space Sciences Laboratory of UC Berkeley. Hiroki Yamashita worked on this project beginning in his junior year (Sep. 2003) until shortly after his graduation (July 2005). Hiroki obtained a Master of Science in Physics from McGill University in 2007
Fund The research was supported by a NASA FUSE grant and the UW-L Science and Health Dean's Distinguished Summer Fellowship
 
( 29 )   Recorded at: 1/6/2009      
Title Photoionization of atomic thulium in the region of the 5p excitations
Journal J Phys [B], 2008;41:1-13, Whitfield SB, Caspary K, Wehlitz R, Martins M
Description The partial cross sections, s, and the angular distribution parameters, ß, of the photoelectrons originating from the 4f and 6s subshells of atomic thulium have been measured in the region of the 5p excitations (23 eV–38 eV) using monochromatized synchrotron radiation. The ß curves show considerable variation between the allowed extremes of -1.0 and 2.0 for many of the 4f photolines. In addition, the 6s photoline shows very marked deviations from ß = 2.0 which is indicative of an open-shell atom. We also compare our experimental results with our calculated 4f partial cross sections. This study examines the dynamical effects of electron correlation in an atomic system involving high angular momentum states (the 4f electrons) and sheds light on the quantum mechanical interaction of light and matter
Faculty Scott Whitfield is an associate professor of physics
Student Physics major Kyle Caspary (now a graduate student in physics at the University of Wisconsin-Madison) participated in collecting the data as part of a summer research project and analyzed the bulk of this data the following fall as a continuing part of this research project. Ralf Wehlitz is a staff scientist at the synchrotron radiation facility where the experiment was done and Michael Martins, a staff scientist from the BESSY facility in Germany, carried out the theoretical calculations
Fund This research was sponsored by a National Science Foundation Research at an Undergraduate Institution grant (grant No. 0244812).
 
( 30 )   Recorded at: 12/29/2008      
Title Infrared photodetachment of Ce_ : threshold spectroscopy and resonance structure
Journal Physical Review A, 2007;76:1-8, Walter CW, Gibson ND, Janczak CM, Starr KA, Snedden AP, Field RL III, Andersson P
Description This experimental study investigated the negative ion of cerium using a laser to detach the weakly bound extra electron. The electron affinity of the cerium atom was accurately measured, helping to resolve a significant discrepancy between previous experiments and theoretical calculations for this fundamental atomic property. In addition, the structure of short-lived excited states of the Ce_ negative ion was observed for the first time
Faculty Wes Walter and Dan Gibson are professors of physics
Student Corey Janczak, Keith Starr, Ali Snedden, and Richard Field are all physics majors who participated in the project as summer research assistants. Pontus Andersson is a graduate student from Gothenburg University, Sweden. Corey is in graduate school in physics at Northeastern University, Keith is a high school physics teacher in Teach for America, Ali plans to attend graduate school next year in physics at the University of Notre Dame, and Richard is a rising senior at Denison
Fund The research was supported by grants from the National Science Foundation and by Denison University’s Anderson Summer Research Fund
 
( 31 )   Recorded at: 6/25/2008      
Title Adrenergic receptor activation inhibits hippocampal CA3 epileptiform activity
Journal Mol Pharmacol, 2007;71:1572-1581, Jurgens CW, Hammad HM, Lichter JA, Boese SJ, Nelson BW, Goldenstein BL, Davis KL, Xu K, Hillman KL, Porter JE, Doze VA. a2A
Description The present study examined the role of norepinephrine (NE) in reducing rat hippocampal CA3 epileptiform activity. We utilized single-cell real-time RT-PCR, construction of concentration response curves for adrenergic receptor (AR) agonists, and functional determination of equilibrium dissociation constants of aAR antagonists. Results indicate that the antiepileptic response of NE is mediated by a2AARs, and suggest that the activation of a2AARs may provide a new pharmacotherapeutic strategy for treating epilepsy
Faculty Van Doze is an associate professor of Pharmacology, Physiology & Therapeutics
Student Sarah Boese, Kristin Hillman, Chris Jurgens and Jessica Lichter became involved with this project as undergraduate students. A newly credentialed high school science teacher, Sarah is currently employed as the lab’s technician, Kristin and Chris are doctoral students, and Jessica is in medical school at UND. Brian Nelson and Brianna Goldenstein received research fellowships from the UND School of Medicine & Health Sciences and are both currently applying to graduate school. Kylie Davis, who first joined the lab as an REU student and later continued her research experience with an American Physiological Society Explorations in Biomedicine Undergraduate Summer Research Fellowship for Native Americans, is still an undergraduate. Ke Xu began working with this lab group as a high school senior and is now an undergraduate student at Harvard; he plans to apply to graduate school
Fund The research was supported by the American Epilepsy Society, North Dakota EPSCoR through NSF Grant EPS-0447679, NSF REU Site Grant 0639227, and NIH Grants P20RR017699 and P20RR016471 from the COBRE and INBRE programs, respectively
 
( 32 )   Recorded at: 2/14/2008      
Title Detection of charged particles with charge injection devices
Journal Rev Sci Instrum, 2007;78:063301-1, Fletcher KA, Apker B, Hammond S, Punaro J, Marshall FJ, Laine J, Forties R
Description A method for using charge injection devices (CIDs) for detection of high energy charged particles from inertial confinement fusion reactions was described. Because of the relatively small depletion region of the CID camera (depletion depth of ~7 mm), aluminum foils were placed in front of the device to reduce the energy of the charged particles and maximize the energy deposited in the CID. Simultaneous measurements of 2H(d,p)3H protons with a CID and a surface barrier detector indicated that the CID is an efficient detector of charged fusion products. Tests using high energy alpha particles emitted from a radium-226 source were also reported
Faculty Kurt Fletcher is a professor of physics
Student Ben Apker, Samantha Hammond, and John Punaro participated in this work during their junior and senior years. Apker is currently employed for a small technology company, Hammond is a graduate student in physics at UNC-Chapel Hill, and Punaro is a graduate student in the engineering program at Buffalo. Frederic Marshall is a senior researcher at the University of Rochester's Laboratory for Laser Energetics. Jonathan Laine and Robert Forties were both undergraduate researchers at LLE
Fund This work was supported by the U.S. Department of Energy and the University of Rochester – Laboratory for Laser Energetics
 
( 33 )   Recorded at: 2/14/2008      
Title Linear and branched fluoroazo-benzene chromophores with increased compatibility in semifluorinated polymers
Journal J Polym Sci Part A: Polym Chem, 2007;45:3166-3177, Campbell VE, Paoprasert P, Mykietyn JD, In I, McGee DJ, Gopalan P
Description A family of fluorinated azobenzene-based push-pull chromophores with one, two, and three trifluorovinyl ether groups in linear and branched architecture was synthesized and utilized as active materials in low optical loss electro-optic composites. The composites showed excellent optical clarity, low birefringence, and optical loss less than 0.5 dB/cm, while giving electro-optic coefficients of 3-7 pm/V at the telecommunications wavelength of 1550 nm
Faculty David McGee is professor of physics at Drew. Padma Gopalan is a professor in the materials science and engineering department at UWisconsin-Madison
Student Victoria Campbell, Peerasak Paoprasert, and Insik In are graduate students in the department of materials science and engineering at the University of Wisconsin-Madison. Justin Mykietyn was a chemistry major at Drew University and participated in this research as an NSF-REU student at the University of Wisconsin. He is now in the chemistry graduate program at Yale University
Fund This research was supported by NSF-REU, NSF-RUI and NSF-CAREER awards.
 
( 34 )   Recorded at: 2/14/2008      
Title Photoinduced phase-separation in Bi0.4Ca0.6MnO3 thin films
Journal Phys Rev B, 2007;76:104423, Smolyaninova VN, Talanova E, Kennedy R, Kolagani RM, Overby M, Aldaco L, Yong G, Karki K
Description In this paper we report a study of photoinduced and current-induced resistivity changes in Bi0.4Ca0.6MnO3 thin films. The magnitude of the energy barrier separating metastable conducting phase and charge-ordered insulating phase estimated from the temperature dependence of the lifetime of the photoinduced conducting phase was found to be large, of the order of the charge ordering temperature. The possibility of coexistence of two phases with high refractive index contrast on a sub-micron scale makes these materials interesting for potential photonic device applications.
Faculty VN Smolyaninova and Rajeswari M Kolagani are associate professors at the Department of Physics, Astronomy, and Geosciences
Student R. Kennedy participated in this research in his junior year and continued as a senior thesis project. He is a high school science teacher now. M. Overby participated in this research in his senior year. Overby is in graduate school at present. L. Aldaco is employed by the US Government. K. Karki contributed to this research during his junior year. He is continuing to participate in research working on his senior thesis project now
Fund This work is supported by the NSF grants DMR-0348939, DMR-0453342 and DMR-04221141, and Research Corporation Grant #CC 629
 
( 35 )   Recorded at: 2/14/2008      
Title Enhancement of photoinduced effects in Bi1-xCaxMnO3 thin films
Journal Appl Phys Lett, 2007;90:222501, Smolyaninova VN, Talanova E, Kolagani RM, Yong G, Kennedy R, Steger M, Schaefer D, Wall K
Description We have found a considerable increase of the photoinduced resistivity changes and the lifetime of these changes in the Bi0.4Ca0.6MnO3 thin films after depositing gold nanoparticles on the surface. A possible interpretation of this effect may be the enhancement of local electromagnetic field at the interface between the film and the metal nanoparticles due to the plasmon resonance. This phenomenon is interesting from the point of view of potential optoelectronic switching and memory device applications
Faculty VN Smolyaninova, RM Kolagani and D Schaefer are professors at the Department of Physics, Astronomy, and Geosciences
Student R. Kennedy participated in this research the summer of his senior year. He is a high school science teacher now. M. Steger participated in this work as REU student. K. Wall participated in this research in her senior year. Steger and K. Wall are in graduate schools at present.
Fund This work is supported by the NSF grants DMR-0348939, DMR-0453342, and DMR-04221141.
 
( 36 )   Recorded at: 2/14/2008      
Title Period-color and amplitude-color relations in classical Cepheid variables - V: The Small Magellanic Cloud Cepheid models
Journal Mon Not R Astron Soc, 2007;380:819-827, Kanbur SM, Ngeow C, Feiden G
Description Period-color and amplitude-color relations at maximum, mean and minimum light are constructed from a large grid of full amplitude hydrodynamic models of Cepheids with a composition appropriate for the Small Magellanic Cloud (SMC). We compare these theoretical relations with those found from observations. The theoretical relations are, in general, in good agreement with their observational counterparts, although there exist some discrepancy from short period (log P < 1) Cepheids. We outline a physical mechanism which can, in principle, be one factor to explain observed PC/AC relations for the long and short period Cepheids in the Galaxy, Large Magellanic Cloud (LMC) and SMC. Our explanation relies on the hydrogen ionization front (HIF)-photosphere interaction and the way this interaction changes with pulsation period, phase and metallicity. Since the PC relation is connected with the period-luminosity (PL) relation, it is postulated that such a mechanism can also explain observed properties of the PL relation in these three galaxies
Faculty Shashi M. Kanbur is assistant professor in the Department of Physics
Student Greg Feiden is a Physics senior. He did this work while supported for the summer by a grant from the Dean of Arts and Sciences, SUNY Oswego. He hopes to go to graduate school in 2008.
 
( 37 )   Recorded at: 2/14/2008      
Title Structural and chemical changes in ultra-high-molecular-weight polyethylene due to gamma radiation-induced crosslinking and annealing in air
Journal Bio-Med Mater Eng, 2007;17:257-268, Viano AM, Spence KE, Shanks MA, Scott MA, Redfearn RD, Carlson CW, Holm TA, Ray AK
Description The crystalline features of ultra-high-molecular-weight polyethylene, the material most commonly used in the role of cartilage in human joint prostheses, were examined as a function of sterilization and aging in air. Structural changes were correlated with chemical measurements of cross-linking in the polymer, and the results suggest two different cross-linking pathways; one with positive effects on the mechanical properties of the material and one implicating less desirable mechanical performance
Faculty Ann Viano is a professor of physics. Richard Redfearn is a former professor of chemistry. Asit Ray is a professor of chemical and biochemical engineering at Christian Brothers University
Student Karyn Spence, Matthew Shanks, and Drew Scott participated as undergraduate physics majors, and Carl Carlson and Terese Holm participated as undergraduate chemistry majors. All of these students were involved in this project as summer research associates for one or more summers in their undergraduate careers. Spence is currently pursuing a doctorate in physics at Washington University. Scott is currently pursuing an MD at the University of Tennessee Health Sciences Center. Shanks and Holm are currently employed in industry, and Carlson is employed in education
Fund The research was supported through a Merck-AAAS Undergraduate Science Research Program Award
 
( 38 )   Recorded at: 2/14/2008      
Title Investigations of the nonlinear LMC Cepheid period-luminosity relation with testimator and Schwarz Information Criterion methods
Journal Publ Astron Soc Pac, 2007;119:512-522, Kanbur SM, Ngeow C, Nanthakumar A, Stevens R
Description In this paper, we investigate the linearity versus nonlinearity of the Large Magellanic Cloud (LMC) Cepheid period-luminosity (PL) relation using two statistical approaches not previously applie to this problem: the testimator method andSchwarz Information Criterion (SIC). The testimator method as extended to multiple stages for the first time and is shown to be unbiased, and the variance of the estimated slope can be proven to be smaller than the standard slope estimated from linear regression theory. The Schwarz Information Criterion (also known as the Bayesian Information Criterion) is more conservative than the Aikake Information Criterion and tends to prefer lower order models. By using simulated datasets, we verify that these statistical techniques can be used to detect intrinsically linear and nonlinear PL relations. These methods are then applied to independent LMC Cepheid data sets from the OGLE and MACHO projects. Our results imply that there is a change of slope in longer period ranges for all of the data sets. This strongly supports previous results obtained from independent statistical tests, which show that the observed LMC P-L relation is nonlinear with a break period at or around 10 days
Faculty Shashi M. Kanbur is assistant professor in the Department of Physics and A. Nanthakumar is professor in the Department of Mathematics
Student Richard Stevens graduated in Mathematics and is currently working for a Power Company in the North East
Fund Richard Stevens was a Math senior who contributed significantly to this work. as volunteer who was paid a nominal grant for the work which was supplied from the PI's existing Space Telescope grant
 
( 39 )   Recorded at: 11/19/2007      
Title An upgraded high-velocity dust particle accelerator at Concordia College in Moorhead, Minnesota
Journal Int J Impact Eng, 2006;33:402-409, Manning HLK, Gregoire JM
Description Concordia College is home to a 2MeV dust particle accelerator originally developed at NASA's Goddard Space Flight Center in the mid-1960's. This is the only dust particle accelerator in the United States and one of three operational dust particle accelerators in the world. Updates to the electronics system and vacuum system were made to this facility to keep it operational and available for use by scientists around the world.
Faculty Heidi Manning is an associate professor of physics.
Student John Gregoire participated in this research the summer after his sophomore and junior years. He is currently a graduate student at Cornell University
Fund The research was supported through a grant from the Minnesota Space Grant Consortium
 
( 40 )   Recorded at: 11/19/2007      
Title Connecting structure and dynamics in glass forming materials by photon correlation spectroscopy
Journal Phys Rev B., 2007;75:132201-04, Sidebottom DL, Rodenburg BV, Changstrom JC
Description Photon correlation spectroscopy measurements of the a-relaxation in a series of glass forming liquids of widely varying fragility demonstrate a correlation between the non-ergodic level of the liquid and its fragility. This correlation, when combined with a previous correlation established between fragility and the stretching exponent that characterizes the non-exponentiality of the a-relaxation, implies that the a-relaxation should in general conform to scaling that is described by just two parameters: the non-ergodic level and the glass transition temperature
Faculty David Sidebottom is assistant professor of physics
Student Jessica Changstrom is a second year graduate student pursuing a MS. Brandon Rodenburg participated in this research beginning during his sophomore year and has recently graduated with a BS in physics
Fund The research was funded by grants from Research Corporation and from the Petroleum Research Fund
 
( 41 )   Recorded at: 11/19/2007      
Title Lattice thermal conductivity of nanoscale AlN/GaN/AlN heterostructures: Effects of partial phonon spatial confinement
Journal J Appl Phys., 2006;100:104309-1-104309-8, Zou J, Lange X, Richardson C
Description A detailed theoretical modeling of thermal conductivity in a nanoscale AlN/GaN/AlN heterostructure was reported. Thermal conductivity in a heterostructure was shown to be higher than that in a single GaN thin film due to partial confinement of phonons. The thermal conductivity could also be tuned by adjusting the thickness of the GaN core layer. The obtained results are important for thermal management in nanodevices
Faculty Jie Zou is an assistant professor of physics
Student Xavier Lange and Chris Richardson enrolled in Research in Physics course in spring and summer 2006 and participated in this research as their course project. Xavier Lange is a junior pre-engineering student and will continue his study in the Department of Electrical and Computer Engineering at the University of Illinois at Urbana-Champaign, starting fall 2007. Chris Richardson is currently a junior physics major at the department.
Fund The research was supported through an internal grant from Eastern Illinois University-the Council on Faculty Research grant
 
( 42 )   Recorded at: 11/19/2007      
Title Global profiles of compressional ultralow frequency wave power at geosynchronous orbit and their response to the solar wind
Journal J Geophys Res., 2007;A05224:1-8, Sanny J, Judnick D, Moldwin MB, Berube D, Sibeck DG
Description The global profiles of compressional wave power in three ULF frequency bands using geosynchronous magnetic field data were investigated. For high and low geomagnetic activity, the greatest power is located in the afternoon sector and around midnight respectively. A summer power minimum in all three frequency bands is observed. The enhancement of ULF power by high solar wind velocity and pressure is greater for the lower-frequency waves, and solar wind plasma parameters have a significantly greater influence on ULF wave power than IMF parameters
Faculty Jeff Sanny is a professor of physics Loyola Marymount University; Mark Moldwin is associate professor of earth and space sciences at UCLA; David Berube is a visiting professor of physics at Loyola Marymount University; David Sibeck is a space physicist at NASA
Student Daniel Judnick participated in this research in the summer of his junior year and during his senior year. He is currently an engineer in the aerospace industry
Fund The research was supported by an NSF Magnetospheric Physics grant.
 
( 43 )   Recorded at: 10/24/2007      
Title . Inflaton fragmentation after lambda phi4 inflation
Journal J Cosmol Astropart P, 2007;2:014, Felder GN, Navros O
Description We used computer simulations to examine the development of spatial inhomogeneities during reheating after inflation in a quartic chaotic inflation model. We confirmed that the process of production of inhomogeneities in this model is qualitatively similar to what had been found for a quadratic model, but we were able to continue our simulations much longer and determine the time scale on which these fluctuations remain non-Gaussian. This information is crucial for attempts to analytically model the subsequent evolution of the fields
Faculty Gary Felder is an assistant professor of physics
Student Olga Navros participated in this work during the summer after her first year at the University of North Carolina, Chapel Hill, where she is an undergraduate
Fund This research was supported by NSF grant PHY-0456631
 
( 44 )   Recorded at: 10/24/2007      
Title Equation of state and high-pressure stability of Fe3P-schreibersite: Implications for phosphorus storage in planetary cores
Journal Geophys Res Lett, 2007;34:L06302, doi:10.1029/2006GL029160, Scott HP, Huggins S, Frank MR, Maglio SJ, Martin CD, Meng Y, Santillan J, Williams Q
Description Synchrotron X-ray diffraction and Diamond Anvil Cells (DACs) were used to measure the crystalline structure of Fe3P-schreibersite as a function of pressure. It is well-established that Earth's core is about 10% less dense than pure iron; furthermore, schreibersite inclusions in iron meteorites suggest that the presence of phosphorus may partially explain this density deficit. However, the results of this study indicate that the structure of schreibersite is not stable at the pressures of Earth's core
Faculty Henry Scott is an assistant professor of physics
Student Sabrina Huggins is an undergraduate senior in the same department. Sabrina completed this work during summer 2006. Sabrina will graduate this May and will pursue a master's degree in Earth science beginning next year, but she has not yet made a final decision regarding the school.
Fund This work was funded by the IUSB SMART Summer Fellowship Program. This work was also supported by an ACS PRF Starter Grant.
 
( 45 )   Recorded at: 10/24/2007      
Title Linear growth of spiral SASI modes in core-collapse supernovae
Journal Astrophys J, 2007;656:366-371, Blondin JM, Shaw S
Description We investigated the growth of spiral modes of the recently discovered spherical accretion shock instability using two-dimensional simulations of the post-bounce accretion flow of a core-collapse supernova. We measured linear growth rates of one, two, and three-armed spiral modes, and studied the process by which the distorted accretion shock can efficiently separate angular momentum in the post-shock flow leading to a spin-up of the underlying accreting proto-neutron star
Faculty John Blondin is professor of physics
Student Samantha Shaw began this project during the summer after her junior year and continued throughout her senior year. She is now in the graduate program in mechanical engineering at NC State University
Fund The research was supported through the Terascale Supernova Initiative, funded by a SciDAC grant from the US Department of Energy
 
( 46 )   Recorded at: 4/18/2007      
Title Infrared spectroscopy for the identification of modes of vibration in a temporary HeNe molecule
Journal J Phys Pt B: Atom M P, 2006;39:4683-4700, Bahrim C, Hunt J
Description A quantum model based on a Morse potential was developed for proving the formation of a temporary HeNe molecule during a thermal collision between Helium and Neon atoms. This model reveals the existence of molecular interactions between two rare gas atoms, through the discovery of several modes of vibration within various electronic potential wells of a HeNe* system at interatomic distances less than 6 atomic units. For experimental testing of our results, an infrared laser spectroscopy method is proposed and the abundance of Neon atoms after collision and successful vibrational-electronic excitation is predicted. This study enriches the understanding of the fundamental interactions between rare gas atoms, which are considered chemical inert by the standard models of chemical physics. This finding could improve the efficiency of HeNe lasers, which are widely used in industry and research, today
Faculty Cristian Bahrim is assistant professor of physics
Student Joseph Hunt participated in this research project as McNair Scholar during summer and fall of 2005 after his junior year, and as a senior honors thesis project. He is currently in a master’s program at University of Texas at Austin
Fund The research was supported by the McNair Program of the Department of Education and by Lamar University through a Research Enhancement Grant.
 
( 47 )   Recorded at: 4/18/2007      
Title Deducing the 237U(n,f) cross section using the surrogate ratio method.
Journal Phys. Rev. C, 2006:73, 054604, Burke TJ, Bernstein LA, Escher J, Ahle L, Church JA, Dietrich FS, Moody KJ, Norman EB, Phair L, Fallon P, Clark R, Deleplanque MA, Descovich M, Cromaz M, Lee IY, Macchiavelli AO, McMahan MA, Moretto LA, Rodriguez-Vieitez E, Stephens FS, Ai H, Plettner C., Beausang CW, Crider B
Description The cross section for 237U(n,f) has been deduced over an equivalent neutron energy range from 0 to 20 MeV using the surrogate ratio method. A 55 MeV 4He beam from the 88 inch cyclotron at Lawrence Berkeley National Laboratory was used to induce fission in the following reactions: 238U(a,a'f) and 236U(a,a'f). The 238U reaction was a surrogate for 237U(n,f), and the 236U reaction was used as a surrogate for 235U(n,f). Scattered a particles were detected in a fully depleted segmented silicon telescope array over an angle range of 35° to 60° with respect to the beam axis. The fission fragments were detected in a third independent silicon detector located at backward angles between 106° and 131
Faculty Jason Burke, Lee Bernstein, Jutta Escher, Larry Ahle, Jennifer Church, Frank Dietrich, Ken Moody and Eric Norman are scientists at Lawrence Livermore National Laboratory. Larry Phair, Paul Fallon, rod Clark, Marie-Agnes Deleplanque, Martina Descovich, Mario Cromaz, I-Yang Lee, Augusto Macchiavelli, Peggy McMahon, Luciano Moretto, E. Rodriguez-Vieitez and Frank Stephens are scientists at Lawrence Berkeley National Laboratory
Student John Ai is a graduate student and Cristina Plettner a postdoctoral fellow at Yale University. Cornelius Beausang is an associate professor at the University of Richmond. Ben Crider participated in this research during his junior year and then continued it as part of his senior project. Ben is currently attending graduate school in physics at the University of Kentucky.
 
( 48 )   Recorded at: 4/18/2007      
Title The role of shock waves in expansion tube accelerators
Journal Am J Phys, 2006;74(12):1071-1076, Olson G, Peterson R, Pulford B, Seaberg M, Stein K, Stelter C, Weber R
Description A recently popular physics classroom demonstration (the “ping pong cannon”) has led to a research effort involving a variety of optical measurements and a numerical simulation of the highly transient fluid dynamics. Only be utilizing the numerical simulation, combined with optical interferometry and schlieren, has it been possible to determine what serves to drive the ball explosively from the cannon at near the speed of sound
Faculty Peterson and Stein are professors of physics at Bethel UniversityPulford and Weber are now graduate fellows in optical physics at the U of NM, while Stelter, Seaberg and Olson are seniors graduating in 2007
Student Research supported by the MN NASA Space Grant and the Carlsen-Lewis endowment at Bethel University
 
( 49 )   Recorded at: 2/22/2007      
Title Variable time lag and backward ejection in full-dimensional analysis of strong-field double ionization
Journal Phys Rev Lett, 2006;97:103008:1-4, Haan SL, Breen L, Karim A, Eberly JH
Description The work employed classical ensembles to do computer modeling of double ionization of atoms by intense laser fields. It was discovered that in most of the double ionizations there was a time lag of a portion of a laser cycle between a recollision event and the actual ionization of the struck electron. This time lag was shown to be crucial to explaining existing experimental results regarding final electron momenta
Faculty Stan Haan is a professor of physics. J.H. Eberly is professor of physics at the University of Rochester
Student Llian Breen was a student worker on the project from January 2004 - December 2005, including two summers fulltime. He has graduated and is working for NOAA. Armin Karim started working on the project in summer 2005. He worked fulltime in summer and part-time during the academic year, and is presently a senior at Calvin College
Fund Student research was supported by an NSF-RUI grant and by Calvin College
 
( 50 )   Recorded at: 2/21/2007      
Title The Absolute Dimensions of the Overcontact Binary FI Bootis
Journal Astron J, 2006;32:1153-1157, Terrell D, Osborn WH, Smolinski JP, Gross J
Description UBVRI photometry of the eclipsing binary FI Bootis was obtained and analyzed simultaneously with previously published photometry and radial velocities. The analysis of the light and radial velocity curves shows that the system is an A-type W UMa system consisting of stars of 0.82 and 0.31 solar masses.
Faculty Wayne Osborn is a professor of physics
Student Jason Smolinski participated in the observations as part of class project in his junior year and assisted with the data analysis as a senior. He is currently a graduate student in astronomy at Michigan State University. John Gross is an observer at the Sonoita Research Observatory, AZ. Dirk Terrell is an astronomer with the Southwest Research Institute
 
( 51 )   Recorded at: 2/21/2007      
Title Measurement of double stars with a CCD camera: Two methods. Revista Mexicana de Astronomía y Astrofísica (Serie de Conferencias
Journal , 2006; 25:65-68, Smolinski, JP, Osborn WH
Description This research investigated using equatorial coordinates to determine separation ? and position angle ? for double stars rather than the traditional approach of computing them from rectangular coordinates. A comparison of the derived values from both methods for the same stellar images showed the two methods are equivalent. Measures for 62 neglected double stars were obtained
Faculty Wayne Osborn is professor of physics
Student He is currently a graduate student in astronomy at Michigan State University
 
( 52 )   Recorded at: 12/8/2006      
Title Effect of electrically insulating materials on magnetically induced electrical currents in a tissue-like medium
Journal Am J Phys, 2006;74(4):260-266, Hoffmeister BK, Shores AR, Banerjee S, Malkin RA
Description This study explored how the presence of plastic medical implants in a patient’s body can interact with electric fields produced by the time varying magnetic fields that occur during a magnetic resonance imaging (MRI) scan. We developed an analytical model based on Coulomb’s Law and Faraday’s Law that describes the influence of electrically insulating materials on the magnetically induced electric fields. In addition, we performed experimental measurements using Helmholtz coils to produce time varying magnetic fields in a volume of physiologic saline solution that served as a tissue-like medium. Pieces of plastic with different geometries were placed in the saline solution, and electric fields were measured in the saline using an inexpensive homemade probe. Predictions of the theoretical model compared well to experimental measurements
Faculty Brent Hoffmeister and Shubho Banerjee are physics professors at Rhodes College. Robert Malkin is a professor of biomedical engineering at Duke University
Student Andrew Shores participated in this research through his junior and senior years. He is currently a graduate student in electrical engineering at Duke University.
 
( 53 )   Recorded at: 12/8/2006      
Title Nonreactive molecular dynamics force field for crystalline hexahydro-1,3,5-trinitro-1,3,5 triazine
Journal J Chem Phys, 2006:124;104508-104517, Boyd S, Gravelle M, Politzer P
Description A classical force field for the use in Molecular Dynamics and Monte Carlo simulations of defect behavior in the explosive substance RDX has been developed extensively tested. Point defects play a crucial role during detonation initiation. This force field will allow us to proceed in the study of the properties of topological defects
Faculty Sylke Boyd is a physics professor at the University of Minnesota - Morris; Peter Politzer is a chemistry professor emeritus at the University of New Orleans
Student Matthew Gravelle tested the force field on vacancies and rotational defects during his junior year, and is working toward a teaching licensure.
Fund The research was funded by a Grant in Aid of Undergraduate Research from the Dean of the Graduate School of the University of Minnesota
 
( 54 )   Recorded at: 12/8/2006      
Title In search of a new molecule
Journal Intnatl J Schol AcadIntellect Div, 2006;8:1-18, Hunt J, Bahrim C
Description A quantum model was developed to prove the formation of a temporary HeNe molecule during a thermal collision between Helium and Neon atoms. This model reveals the existence of molecular interactions between two rare gas atoms, and indicates several electronic potential wells at distances less than 6 atomic units between Helium and Neon atoms. Using a Morse potential model, several modes of vibration within each potential well are identified, as a clear signature for the formation of a HeNe molecule. For experimental testing our results, an infrared laser spectroscopy method is proposed, and the abundance of Neon atoms after collision and successful vibrational-electronic excitation is predicted. This study enriches the understanding of the fundamental interactions between rare gas atoms and also, it could improve the efficiency of HeNe lasers, which are widely used in industry and research, today
Faculty Cristian Bahrim is assistant professor of physics at Lamar University
Student Joseph Hunt participated in this research project as McNair Scholar in the summer after his junior year and then continued it as a senior honors thesis project. This fall, he will start a Master Thesis at University of Texas at Austin
Fund The research was supported through the Research Enhancement Grant at Lamar University.
 
( 55 )   Recorded at: 12/8/2006      
Title Thermally stable Schottky contacts on n-type GaN using ZrB2
Journal Appl Phys Lett, 2006;88:183505-1 – 183505-3, Oder TN, Martin P, Lin J, Jiang H, Williams JR, Isaacs-Smith T
Description The electrical properties and thermal stability of ZrB2 Schottky contacts deposited on n-type GaN were studied. As-deposited contacts had a barrier height of 0.80 eV, which decreased to 0.7 eV after annealing at 300 °C, and to 0.6 eV after additional annealing at 400 °C in nitrogen for 20 min. However, the barrier height remained at about 0.6 eV even when the contacts were annealed at 600 °C for 20 min. The Rutherford backscattering spectra of the annealed contacts showed no reaction at the ZrB2/GaN interface. These results indicate excellent thermal stability of ZrB2/GaN Schottky contacts and therefore make them attractive for fabricating electronic devices for high temperature applications
Faculty Tom N. Oder is a professor of physics at Youngstown State University. Jingyu Lin and Hongxing Jiang are professors of physics at Kansas State University. John R. Williams is a professor of physics at Auburn University. Tami Isaacs-Smith is a research associate at Auburn University
Student Pamela Martin participated in this research in her junior and senior years as a physics undergraduate student at Youngstown State University. She graduated in May 2006 with a B.S. in Physics and is starting her PhD program in materials science and engineering at the University of Illinois at Urbana-Champaign
Fund This research was supported by funds from Youngstown State University.
 
( 56 )   Recorded at: 12/8/2006      
Title Exact analytical and numerical calculation of the radiative recombination cross sections of fully stripped ions
Journal J Electro Waves Appl, 2006;20(11):1495-1501, Zerrad E, Charlot D, Hahn Y
Description Radiative recombination (RR) is one of the fundamental processes of importance in the studies of astrophysics and plasma physics. In this process, free electrons are captured into one of the infinite number of vacant orbitals of a target ion of charge Z and the excess of energy is emitted as a photon, Analytical expressions for the direct RR cross section are derived within a non-relativistic treatment in the dipole approximation for hydrogenic systems with one electron at any given incident energy
Faculty Essaid Zerrad is an associate professor, Department of Physics/Pre-Engineering at Delaware State University; Yukap Hahn, consultant
Student David Charlot participated in this research in his junior and senior years. Currently, he is a PhD student at University of California San Diego
Fund This research was supported by the Army Research Office
 
( 57 )   Recorded at: 12/8/2006      
Title Ultrasonic characterization of cancellous bone using apparent integrated backscatter
Journal Phys Med Biol, 2006;51:2715-2727, Hoffmeister BK, Jones III CI, Caldwell GJ, Kaste SC
Description This study tested the utility of an ultrasonic backscatter technique called “Apparent Integrated Backscatter” for diagnosing degenerative bone diseases such as osteoporosis. Measurements were performed on specimens of bovine cancellous (i.e., spongy) bone using two different broadband ultrasonic transducers with center frequencies of 1 and 5 MHz. The sensitivity of the technique was found to be strongly frequency dependent, with the 5 MHz transducer exhibiting much better sensitivity to changes in bone density than the 1 MHz transducer
Faculty Brent Hoffmeister is a professor of physics at Rhodes College. Sue Kaste is a member of the faculty at Saint Jude Children’s Research Hospital
Student Charles Jones and Garnet Caldwell participated in this research the summer after their junior and sophomore years, respectively. Jones completed a maters degree in biomedical engineering at Ohio State University and plans to enter medical school
Fund The research was supported through a NSF-RUI grant
 
( 58 )   Recorded at: 7/20/2006      
Title Two-photon spectroscopy of rubidium using a grating-feedback diode laser.
Journal Am J Phys., 2006;74:218-223, Olson AJ, Carlson EJ, Mayer SK
Description Two-photon spectroscopy was used to investigate the transition in rubidium using a single grating-feedback diode laser operating at 778.1 nm (385 THz). Continuous tuning of the laser frequency over 4 GHz allowed for clear resolution of the Doppler-free spectral features and gave rise to accurate measurement of the hyperfine ground-state splitting in rubidium. A direct comparison between Doppler-broadened and Doppler-free spectral features was possible since both were distinctly evident in the two-photon spectra. By independently modifying the polarization state of the two laser fields, the impact of electric dipole selection rules on the two-photon transition spectra were investigated.
Faculty Shannon Mayer is an associate professor of physics at the University of Portland.
Student Abraham Olson and Evan Carlson participated in this research the summer after their sophomore years. Both students are currently juniors at the University of Portland
Fund The research was supported by the M. J. Murdock Charitable Trust
 
( 59 )   Recorded at: 7/20/2006      
Title Chromophore orientation dynamics, phase stability, and photorefractive effects in branched azobenzene chromophores
Journal Macromol, 2006;39:957-961, Campbell VE, In I, McGee DJ, Woodward N, Caruso A, Gopalan P
Description The increased solubility and uniform dispersal of branched azobenzed chromophores over their monomeric analogues have been shown to improve the nonlinear optical performance of high glass transition temperature polymers. We investigated the application of these branched chromophores as guest nonlinear optical molecules in the plasticized polymer host polyvinylcarbazole and demonstrated the presence of photorefractive index gratings
Faculty David McGee is associate professor of physics at Drew University, Padma Gopalan is assistant professor of materials science at University of Wisconsin-Madison
Student Victoria Campbell and Insik In are graduate students in materials science at University of Wisconsin-Madison. Nathaniel Woodward and Anthony Caruso participated in this research as undergraduate physics and chemistry majors, respectively, at Drew. Both students started as summer researchers and continued the work as independent study projects for two years. Nathaniel is currently a graduate student in physics at Lehigh University and Anthony is applying to graduate school for chemistry.
Fund McGee, Woodward, and Caruso were supported by a NSF-RUI grant
 
( 60 )   Recorded at: 7/20/2006      
Title Stratosphere-troposphere evolution during polar vortex intensification
Journal J Geophys Res–Atmos, 2005:110: D24101, Limpasuvan V, Hartmann DL, Thompson DWJ, Jeev K, Yung YL
Description The coupled dynamics between the stratosphere and troposphere were examined during polar vortex intensification events. Anomalous wave activities (originating in the stratosphere) penetrated across the tropopause and significantly influenced the near-surface circulation. These occurrences are prevalent during La Nina climate conditions. Understanding of such coupling mechanisms potentially holds a key to improving mid-range weather forecasting and understanding climate evolution
Faculty Varavut Limpasuvan is an associate professor of applied physics at Coastal Carolina University (CCU). Dennis L. Hartmann is a professor of atmospheric science at the University of Washington. David W. J. Thompson is an assistant professor of atmospheric science at Colorado State University. Yuk L. Yung is a professor of geological and planetary sciences at the California Institute of Technology
Student Starting as a CCU junior, Kumar Jeev participated in this research for two years through independent study and summer projects. He is currently completing his master’s degree in computer science and atmospheric sciences at the Johns Hopkins University
Fund The research was supported through a NSF-RUI grant
 
( 61 )   Recorded at: 7/20/2006      
Title Lightcurve and rotation period determination for minor planet 4006 Sandler.
Journal Minor Planet Bulletin, 2006;33:1,1, Vonk MT, Kopchinski DJ, Pittman AR, Taubel S
Description Minor planet 4006 Sandler was observed during January and February of 2005. The synodic period was measured and determined to be 3.40 ± 0.01 hours with an amplitude of 0.16 magnitude
Faculty Matthew Vonk is assistant professor of physics
Student Daniel Kopshinski, Amanda Pittman and Stephen Taubel are upper-class physics majors who undertook this project as an independent study opportunity in the spring of 2005
Fund This project was funded by the UWRF Foundation.
 
( 62 )   Recorded at: 7/19/2006      
Title Chiral symmetry and signature splitting in odd-odd neutron deficient Pr nuclei
Journal European Physical Journal A direct, 2005, DOI: 10.1140/epjad/i2005-06-175-0, Fetea MS, Nikolova V, Crider B
Description The features of the electromagnetic transitions in the chiral 132Pr and 134Pr were investigated within the framework of particle rotor model, to understand why, at low spins, the measured B(M1)/B(E2) ratios for the yrare band are almost an order of magnitude larger than the corresponding ratios for the yrast band
Faculty Mirela Fetea is an assistant professor of physics
Student Veronika Nikolova and Benjamin Crider participated in this research in the summer between their sophomore and junior years, and continued it during their junior years. They are currently seniors at the University of Richmond
Fund This work was supported by the NSF Grant PHY 0204811 and Research Corporation Grant CC5494
 
( 63 )   Recorded at: 7/19/2006      
Title Localization of Floquet states along a continuous line of periodic orbits
Journal Physical Review E., 2005:016208, Timberlake TK, Petruzielo FR, Reichl LE
Description A periodically driven particle in an infinite square well is shown to exhibit quantum localization due to a continuous line of periodic orbits in the classical system. Individual Floquet eigenstates localized along this line of periodic orbits are identified. The enhanced localization persists for field strengths beyond that at which the continuous line of orbits is destroyed in the classical dynamics. These results may be relevant to experiments involving trapping potentials with flat regions
Faculty Todd K. Timberlake is an assistant professor of physics at Berry College. Linda E. Reichl is a professor of physics at the University of Texas at Austin.
Student Frank R. Petruzielo participated in this research as part of the Summer Work Program at Berry College during the summer after his sophomore year, and continued his work during the Fall of his junior year. Frank will graduate from Berry in 2006 and plans to begin graduate work in physics that Fall
Fund This work was supported by the Berry College Office of Student Work.
 
( 64 )   Recorded at: 7/19/2006      
Title A maskless photolithographic prototyping system using a low-cost consumer projector and a microscope
Journal American Journal of Physics, 2005(73):980-984, Musgraves JD, Close BT, Tanenbaum DM
Description Lithographic processing has been the key technology responsible for the rapid advances in microelectronics, but is typically not accessible to undergraduates. We have developed a maskless photolithographic system that can be assembled from a consumer projector and a trinocular microscope. This system allows students to design and print custom patterns into photoresist in less than 30 min, without using a clean room, a mask facility, or a chrome-etch bath. The entire system can be assembled for less than $5000
Faculty David M. Tanenbaum is an associate professor of physics and astronomy
Student J. David Musgraves worked on this project during the summer following his junior year as well as for his senior thesis at Pomona College, and is now a graduate student in Materials Science at the University of Arizona. Brett Close ('07) worked on the project as an undergraduate during the summer following his freshman year
Fund The work was supported by both an external NSF grant and Pomona College.
 
( 65 )   Recorded at: 7/19/2006      
Title Closed orbits about a massive thin ring
Journal European Journal of Physics, 2006(27):215 – 223, Tobin RW, West J
Description A study of the gravitational interaction of a unit point mass and a very thin ring was conducted. The work focused on finding closed orbits (trajectories), and these display a surprisingly wide range of patterns. Figures showing 11 distinct families are in the paper, while more than 20 are available online. One of the programs used for the calculations is also available for download so that other undergraduate and high school research groups can extend the studies. Their results will be posted on the website as well, once they are confirmed. http://physics.indstate.edu/west/zoorings/indexnewOrbits.htm
Faculty Joe West is currently the Interim Chair of the department of physics
Student R Wesley Tobin is currently in his first year of graduate studies in physics at Iowa State University. Tobin started this project in the spring of his third year at Indiana State, and continued to work on it for a year and a half, some of the time for academic credit, some of the time for pay, and some of the time for the sheer joy of working on an interesting problem
Fund This work was supported by the Department of Physics, and by the John C. Cook Memorial Observatory, Department of Geography, Geology and Anthropology, of Indiana State University
 
( 66 )   Recorded at: 7/19/2006      
Title Two-field description of chaos synchronization in diode lasers with incoherent optical feedback and injection
Journal Physical Review A, 2005(72):043818, Sukow DW, Gavrielides A, Erneux T, Baracco MJ, Parmenter ZA, Blackburn KL
Description Chaos synchronization in edge-emitting diode lasers with polarization-rotated optical feedback was investigated experimentally and theoretically. High-quality synchronization was observed by use of polarization-resolved measurements of the lasers. In these devices only one polarization state is normally active, and the orthogonal mode is suppressed. However, it was found that a mathematical model including both modes of both lasers is required to accurately capture the observed synchronization dynamics.
Faculty David W. Sukow is an associate professor of physics and engineering at Washington and Lee University. Athanasios Gavrielides is a senior scientist at the Air Force Research Laboratory in Albuquerque, New Mexico. Thomas Erneux is a professor in the theoretical nonlinear optics group at the Universite Libre de Bruxelles, Belgium
Student Michael Baracco, Zachary Parmenter, and Karen Blackburn participated in this research at Washington and Lee University in the summer of 2004. Michael is now working as a systems engineer for Lockheed-Martin. Karen is completing her senior year as a physics major
Fund This research was supported by National Science Foundation CAREER grant #0239413
 
( 67 )   Recorded at: 7/19/2006      
Title Chiral degeneracy in mass 130 region
Journal Journal of Physics G: Nuclear and Particle Physics, . 2005(31):S1847- S1850, MS Fetea, V Nikolova, B Crider
Description The theoretical understanding of transition rates in chiral nuclei poses a challenge for many model-calculations. Particle Rotor Model calculations have been performed in the mass 130 region, to elucidate the salient features of chiral rotation. The laboratory frame description yields the splitting between bands and follows the transition probabilities evolution from planar to chiral and then axial regions
Faculty Mirela Fetea is an assistant professor of physics
Student Veronika Nikolova and Benjamin Crider participated in this research in the summer between their sophomore and junior years, and continued it during their junior years. They are currently seniors at the University of Richmond
Fund This work was supported by the NSF Grant PHY 0204811 and Research Corporation Grant CC5494
 
( 68 )   Recorded at: 1/6/2006      
Title More on the Asymmetric Infinite Square Well: Energy Eigenstates with Zero-curvature
Journal European Journal of Physics, 2005, 26, 815-825, Laura P. Gilbert, Mario Belloni, Michael A. Doncheski, Richard W. Robinett (Davidson College).
Description The standard treatment of the asymmetric infinite square well was extended to include solutions that have zero curvature over part of the well. The general mathematical condition was developed, focusing on zero-curvature solutions as represented by energy eigenstates in position and momentum space.
Faculty Mario Belloni is an associate professor of physics at Davidson College. Michael A. Doncheski is an associate professor of physics at Pennsylvania State University. Richard W. Robinett is a professor of physics at Pennsylvania State University.
Student Davidson College physics major Laura P. Gilbert participated in this research the summer after her sophomore year and is currently a senior continuing this and related work as an Honors thesis.
Fund The research was supported through grants from the Research Corporation and Davidson College.
 
( 69 )   Recorded at: 1/6/2006      
Title Response of CR-39 to Medium Energy Electron Irradiation
Journal Radiation Measurements, 2005, 40, 43-49, Christopher G. Wahl, James G. McLean (SUNY Geneseo).
Description The effect of 5–15 keV electron irradiation on the etch rate of CR-39 nuclear track detectors was investigated for surface doses from 0.09 to 13.85 J/cm2. Etch rate enhancement was observed in the surface region (about 4um deep) and was well approximated by a Gaussian function of depth. No signs of a saturated response were found in the etch rate. This enhanced etching rate may significantly affect nuclear track identification in situations with an electron background.
Faculty James McLean is a professor of physics at SUNY Geneseo.
Student Christopher Wahl participated in this research the summers after his freshman and sophomore years and within a faculty research assistantship during the spring of his sophomore year. He is currently a senior at SUNY Geneseo.
Fund The research was supported through grants from the NY Space Grant Consortium and SUNY.
 
( 70 )   Recorded at: 9/29/2005      
Title The Metallic Nature of Boron Layers in Magnesium Diboride
Journal International Journal of Modern Physics B, 2003, 17, 5905-5910, G. L. Zhao, A. Pullen, D. Bagayoko (Southern University and A&M College).
Description We performed ab initio, local density functional calculations of the electronic structure and mechanical properties of magnesium diboride (MgB2). The calculations revealed the metallic nature of the boron layers in MgB2; they showed the dominance of the boron p in the narrow bands that cross the Fermi level. They also indicated, in light of the light atomic mass of boron and calculated, strong covalent bonds, a strong electron-phonon interaction with a significant contribution to the relatively high critical temperature (Tc) for superconductivity.
Faculty G. L. Zhao and D. Bagayoko are associate professor and distinguished professor of physics, respectively, at Southern University and A&M College in Baton Rouge (SUBR), Louisiana.
Student A. Pullen participated in this research in his sophomore year as an undergraduate research assistant. He is pursuing his Ph.D. degree at the California Institute of Technology in Astro-particle Physics.
Fund This work was funded in part by NASA (Award No. NCC2-1344) and by the Department of the Navy, Office of Naval Research (Award No. N00014-98-1-0748).
 
( 71 )   Recorded at: 9/29/2005      
Title Electron Impact Excitation of Argon and Krypton: Improved R-ratios
Journal Journal of Physics B: Atomic, Molecular and Optical Physics, 2005, 38, 929-937, Stephanie Proctor, Murtadha A. Khakoo (California State University, Fullerton).
Description Recently repeated measurements of differential cross-section ratios (termed r-ratios) for electron impact excitation of the two metastable states of argon and krypton (ratio of the J=3D2 : J=3D0 levels as excited from the ground state) were carried out using a novel moveable target source that was developed in our laboratory. Our results show that, for argon, r stays close to its statistical weight ratio value of 5, in disagreement with earlier measurements. In krypton we not only confirmed our r-ratios taken in previous measurements, but also improved the errors of these ratios by almost half, showing r-ratios that deviate far from the statistical weight value.
Faculty
Student . Stephanie Proctor was a double major at CSUF in Physics and Mathematics. She participated in this work in the year 2003-2004 and is now doing a Mathematics PhD at UC Riverside.
Fund The research was supported through a NSF-RUI grant.
 
( 72 )   Recorded at: 9/29/2005      
Title Preheating in New Inflation
Journal Physics Review D, 2005, 71, 103516:1-10, Mariel Desroche (Smith College), Gary Felder (Smith College), Jan Kratochvil (Stanford University), Andrei Linde (Stanford University).
Description It's known that shortly after the big bang the universe underwent a period of extremely rapid expansion known as inflation. At the end of this inflationary epoch all of the energy in the universe was in the form a single, nearly homogeneous field called the inflaton field. We investigated the decay of the inflaton field into other forms of energy in a class of inflationary models known collectively as "new inflation." We found that inflaton decay in these models occurs through a combination of two highly efficient, non-perturbative field effects known as parametric resonance and tachyonic preheating.
Faculty Andrei Linde is a professor at Stanford University and Jan Kratochvil is a graduate student working with Linde. Gary Felder is a professor at Smith College
Student Mariel Desroche, an undergraduate physics major there, did the work for this project during her sophomore year and the following summer. She will be a senior this coming year.
Fund Her work was supported by a Schultz Foundation Fellowship.
 
( 73 )   Recorded at: 9/29/2005      
Title Magnetite: Raman study of the High-Pressure and Low-Temperature Effects
Journal Journal of Applied Physics, 2005, 97, 10A922-1-10A922-3, L.V. Gasparov, D. Arenas, K.-Y. Choi, G. Guenthrodt, H. Berger, L. Forro, G. Margaritondo, V. V. Struzhkin, R. Hemley (University of North Florida).
Description We use additional Raman modes below the Verwey transition to determine how the transition temperature changes with the hydrostatic pressure. Increase of the hydrostatic pressure results in the linear decrease of the Verwey transition temperature, with no discontinuity. Corresponding pressure coefficient dTV/dP is found to be -5.16±1.19 K/GPa. Such decrease is substantially larger than one predicted by the mean-field Coulomb interaction model of the transition.
Faculty Lev Gasparov is an assistant professor of physics at UNF. Gernot Güntherodt is a professor of physics Kwang-Yong Choi is a graduate student at the 2.Physikalisches Institut RWTH Aachen., Helmut Berger is a stuff scientist, László Forró and Giorgio Margaritondo are professors of physics at EPFL Viktor Struzhkin and Russ Hemley are senior stuff scientists at the Geophysical Laboratory of the Carnegie Institution in Washington DC.
Student Daniel Arenas participated in this research in summer of his senior year and he is currently a graduate student at the Department of Physics in the University of Florida, Gainesville.
Fund The research was supported through the Research Corporation grant and ACS Petroleum Research grant.
 
( 74 )   Recorded at: 9/12/2005      
Title Infrastructure in the Electric Sense: Admittance Data from Shark Hydrogels
Journal , Journal of Comparative Physiology A, 2005, 191, 115-123, Brandon R. Brown, Mary E. Hughes, Clementina Russo (University of San Francisco).
Description In this biophysics effort, electrical admittance spectra were collected for gel samples extracted from the electrosensors of both white sharks and white-tip reef sharks in order to better understand the function of the odd electrosensor morphology. In addition, collagen-based samples were synthesized to various ion contents and measured for comparison to shark gels. The results suggest that the infrastructure promotes potential differences between a shark's skin and its electrosensitive cells instead of providing equipotential contacts between them.
Faculty Brandon R. Brown is an associate professor of physics and the associate dean for sciences at the University of San Francisco
Student Mary E. Hughes and Clementina Russo participated in this research in their junior and senior years as research assistants at USF. Hughes is now in the Applied Physics PhD program at Harvard University, and Russo is in the Physics PhD program at the University of Maine.
Fund The authors acknowledge funding from the Fletcher Jones Foundation, NSF grant CHE-0216617, and the faculty development fund of the University of San Francisco.
 
( 75 )   Recorded at: 9/12/2005      
Title Frequency Measurements of Optically Pumped Laser Emissions from the CHD2OH Methanol Isotope
Journal IEEE Journal of Quantum Electronics,, 2005, 41, 224 – 226, Toby Garrod, Sarah Petersen, Andy Stokes, Michael Theisen, Lyndon Zink, Michael Jackson (University of Wisconsin-La Crosse).
Description A three-laser heterodyne system was used to measure the frequencies of eleven previously observed optically pumped far-infrared (FIR) laser emissions generated by the CHD2OH methanol isotope. These newly measured frequencies have fractional uncertainties of ± 2 ´ 10-7 and correspond to laser wavelengths ranging from 47.8 to 238.0 mm. The pump laser offset frequency was also measured for the first time for fifteen CHD2OH FIR laser emissions.
Faculty Michael Jackson is an associate professor and Lyndon Zink is an academic staff lecturer in the Department of Physics at the University of Wisconsin-La Crosse.
Student Toby Garrod, Sarah Petersen, Andy Stokes and Michael Theisen participated in this research the summer after their sophomore year and then continued it as an upper-division research project.
Fund This research was supported through the National Science Foundation (Grant No. 0114450 – MRI, 0406556 – RUI: Two Year Extension for Special Creativity), the Wisconsin Space Grant Consortium (Undergraduate Research Award and Faculty Seed Grant) and the University of Wisconsin-La Crosse (Dean’s Undergraduate Research Fellowship and Faculty Research Grant).
 
( 76 )   Recorded at: 6/3/2005      
Title Effects of Metallicity on the Rotational Velocities of Massive Stars
Journal The Astrophysical Journal, 2004, 116,1316, Laura R. Penny, Amanda J. Sprague, George Seago (College of Charleston), Douglas R. Gies (Georgia State University)
Description We analyzed 39 archival Hubble Space Telescope Imaging Spectrograph (STIS), high resolution, ultraviolet spectra of O-type stars in the Magellanic Clouds to determine their projected rotational velocities V sin i. Our methodology is based on our previous study of the projected rotational velocities of Galactic O-type stars, which resulted in a catalog of V sin i values for 177 O stars. Here we present complementary V sin i values for 21 Large Magellanic Cloud and 22 Small Magellanic Cloud O-type stars based on STIS and IUE UV spectroscopy. Despite the theoretical predictions and indirect observational evidence for high rotation at low Z, the O type stars in the Magellanic Clouds do not appear to rotate faster than their Galactic counterparts.
Faculty Laura Penny is an associate professor of physics & astronomy at the College of Charleston. Douglas Gies is a professor of physics & astronomy at Georgia State University.
Student Amanda Sprague and George Seago participated in this research the summer after their junior years and then continued as senior projects during their final year at the College of Charleston. The data presented in this paper were obtained from the Multimission Archive at the Space Telescope Science Institute.
Fund Support for this project was provided by NASA.
 
( 77 )   Recorded at: 6/3/2005      
Title 209Bi(6He,alpha) Reaction Mechanism Studied Near the Coulomb Barrier Using n-alpha Coincidence Measurements
Journal Physics Letters B, 2004, 596, 26-31, J. Bychowski, P.A. DeYoung, B.B. Hilldore, J.D. Hinnefeld, A. Vida, F.D. Becchetti, J. Lupton, T.W. O'Donnell, J.J. Kolata, G. Rogachev, M. Hencheck (Hope College)
Description This measurement looked at the way 6He interacts with other nuclei and breaks up by using a low-rate radioactive beam and by measuring coincidences between alpha particles and neutrons. It was found that 20% of the time the 6He breaks up it does so by transfering one neutron to the heavy nucleus.
Faculty P.A. DeYoung is a professor of physics.
Student J.P. Bychowski started research during his sophomore year and continued until graduatation. He is currently a second-year graduate student at the University of Notre Dame. B.B. Hilldore started research during his sophomore year and worked several terms and one summer. He is currently a first year graduate student at the University of Illinois. The other co-authors are collaborators from The University of Notre Dame, the Universtiy of Michigan, and Indiana University at South Bend.
Fund The research was supported by an NSF-RUI grant.
 
( 78 )   Recorded at: 1/5/2005      
Title Effect of Random and Block Copolymer Additives on a Homopolymer Blend Studied by Small Angle Neutron Scattering
Journal Journal of Polymer Science, Part B: Polymer Physics, 2004, 42, 3191-3203, Gretchen Voge, Kari Fosser, Dean Waldow, Robert Briber, Adel Halasa (Pacific Lutheran University)
Description Two random copolymers and one diblock copolymer were studied by small angle neutron scattering (SANS) to assess their effect on the thermodynamics of a polystyrene / polybutadiene polymer blend. The data was analyzed using the Random Phase Approximation for multicomponent blends. The copolymer additives produced shifts in the thermodynamic interaction parameters and in the spinodal decomposition temperatures depending on the copolymer structure and monomer composition. The results helped clarify the effect the various copolymers had on the phase separation behavior of the compatibilized blends and previously published light scattering data
Faculty . Dean Waldow is a professor of chemistry
Student Gretchen Voge conducted research during the summers after her sophomore and junior years and is now in medical school. Kari Fosser conducted research during the summer after her junior year and recently completed her Ph.D. The collaborators, Adel Halasa and Robert Briber, are from Goodyear Tire and Rubber Company and the University of Maryland, College Park, respectively.
Fund The research was supported by NSF-RUI and by instrument time from the Reactor Division at the National Institute of Standards and Technology.
 
( 79 )   Recorded at: 1/5/2005      
Title An Experimental Study of Micron-scale Droplet Aerosols Produced via Ultrasonic Atomization
Journal Physics of Fluids, 2004, 16, 2843-2851, T.D. Donnelly, J. Hogan, A. Mugler, N. Schommer, M. Schubmehl, Andrew J. Bernoff, B. Forrest (Harvey Mudd College)
Description In the last ten years, laser-driven fusion experiments performed on atomic clusters of deuterium have shown a surprisingly high neutron yield per joule of input laser energy. Results indicate that the optimal cluster size for maximizing fusion events should be in the 0.01 to 1 micron diameter range, but an appropriate source of droplets of this size does not exist. In an attempt to meet this need, we use ultrasonic atomization to generate micron-scale droplet aerosols of high average density, and we have developed and refined a reliable droplet sizing technique based on Mie scattering. Harmonic excitation of the fluid in the MHz range yields an aerosol of droplets with diameters of a few microns. The droplet diameter distribution is well-peaked and the relationship between average droplet-size and forcing frequency follows an inviscid scaling law, predictable by dimensional analysis and consistent with the linear theory for Faraday excitation of an infinitely deep fluid.
Faculty T. D. Donnelly is an associate professor of physics. Andrew Bernoff is a professor of mathematics.
Student J. Hogan. A. Mugler, and B. Forrest did the work as a summer project and senior thesis and are currently in graduate school at Stanford, Columbia and Cornell respectively. A. Mugler did the work as a summer project and senior thesis and is currently in graduate school at Columbia. N. Schommer and M. Schubmehl completed summer projects and senior thesis and are currently employed
Fund The work was funded by the Beckman Research Fund and Harvey Mudd College.
 
( 80 )   Recorded at: 1/5/2005      
Title Spectroscopic Method of Strain Analysis in Semiconductor, Quantum-Well Devices
Journal Journal of Applied Physics, 2004, 96, 4056-4065, Mark L. Biermann, Steven Duran, Kelsey Peterson, Axel Gerhardt, Jens W. Tomm, Artem Bercha, Witold Trzeciakowski (U. S. Naval Academy)
Description A description of a generalized, spectroscopically-based technique for analyzing strain in quantum-well-based, opto-electronic devices is provided. Comparison of experimental and theoretical results indicate that this technique provides an excellent means of analyzing packaging-induced strain in commercially available, high-power diode lasers and similar devices, providing a basis for device improvement.
Faculty Mark Biermann a professor of physics and astronomy at Eastern Kentucky University.
Student Axel Gerhardt and Jens Tomm are at the Max Born Institute, Berlin, Germany. Artem Bercha and Witold Trzeciakowski are at the High Pressure Research Center, UNIPRESS, in Warsaw, Poland. Steven Duran and Kelsey Peterson participated in this research through a research course taken during their senior year. Both are currently active duty officers in the U. S. Navy.
Fund The research was supported in part by the U. S. Naval Academy.
 
( 81 )   Recorded at: 1/5/2005      
Title Spectral Broadening in a Microdroplet Dye Laser
Journal Chemical Physics Letters, 2004, 390, 130 - 135, Anders G. Knospe, Alfred S. Kwok (Pomona College)
Description We have observed broadening of the lasing spectrum of 60- m diameter micrdroplet dye lasers. The spectral width of microdroplet dye lasers consisting of Rhodamine 6G or Pyrromethene 597 is essentially constant when water is used as a solvent but broaden by >30% at high input-laser intensities when ethanol is used as solvent. Spectral broadening is preceded by stimulated Raman scattering of ethanol in the microdroplets as the input-laser intensity increases.
Faculty Alfred Kwok is an assistant professor of physics.
Student Anders Knopse graduates in 2006.
 
( 82 )   Recorded at: 11/1/2004      
Title Cavity-Enhanced Emission from a Dye-Coated Microsphere
Journal Optics Express, 2004, 12, 2857-2863, Perry G. Schiro, Alfred S. Kwok (Pomona College)
Description We have observed whispering gallery modes in the inelastic emission from a 9.8 µm polystyrene bead coated with a monolayer of AlexaFluor 488 dye. Using a separate near-IR trapping laser and an Ar+ excitation laser enables us to isolate and study a single dye-coated bead in a colloidal suspension without causing any bead damage.
Faculty Alfred Kwok is an assistant professor of physics.
Student Perry Schiro is currently a graduate student in chemistry at the University of Washington
 
( 83 )   Recorded at: 11/1/2004      
Title Temperature-dependent Scattering of Hyperthermal Energy K+ Ions
Journal Physical Review B, 2004, 70, 115413, Judson Powers, Joseph R. Manson, Chad E. Sosolik(Clemson University), Jennifer R. Hampton, Andone C. Lavery, Barbara H. Cooper (Cornell University).
Description Experimental and theoretical results were obtained for the scattering of potassium ions from a copper surface. Individual scattering events that involved single potassium ions striking one or more surface atoms were identified in the experimental data and examined as a function of surface temperature variations. Modeling of the scattered ion intensity and energy distributions was performed using a classical mechanical theory. The theory successfully reproduced the trends seen for those scattering events that involved single ion-surface atom collisions.
Faculty Joseph Manson and Chad Sosolik are both professors of physics at Clemson University.
Student Judson Powers performed the extensive modeling work for this project during his junior and senior years. Judson is currently a graduate student in physics at Cornell University.
Fund The research was supported by DOE and NSF.
 
( 84 )   Recorded at: 5/5/2004      
Title Star-Shaped Azo-Based Dipolar Chromophores: Design, Synthesis, Matrix Compatibility, and Electro-optic Activity
Journal Journal of the American Chemical Society, 2004, 126, 1741-1747, Padma Gopalan, Howard E. Katz, David J. McGee, Chris Erben, Thomas Zielinski, Danielle Bousquet, David Muller, John Grazul, Ylva Olsson (Drew University)
Description Three new azo-benzene-based push-pull chromophores with dendritic architecture were synthesized as active materials for electro-optic applications. The electro-optic coefficient was measured to be 25 pm/Volt at 1550 nm wavelength, making these chromophores suitable for applications in active photonic devices such as optical modulators.
Faculty David McGee is an associate professor of physics at Drew University. Padma Gopalan, Howard Katz, Chris Erben, David Muller, John Grazul, and Ylva Olsson are with the Materials Research group at Lucent Technologies Bell Labs.
Student Danielle Bousquet is a senior biochemistry major and Thomas Zielinski is a senior physics major at Drew University. Both students began work on this project the summer following their sophomore years and continued for one additional summer. During the academic year, Thomas Zielinski continued the project through Independent Study courses. In Fall 2004, Danielle Bousquet will begin her Ph.D. studies in the biomedical sciences at the University of Connecticut and Thomas Zielinski will attend Brown University for a Ph.D. in physics.
Fund This research was funded by an NSF-RUI grant and Lucent Technologies Bell Labs.
 
( 85 )   Recorded at: 5/5/2004      
Title Geometric Phase Associated with Mode Transformations of Optical Beams Bearing Orbital Angular Momentum
Journal Physical Review Letters, 2003, 90, 203901-1-4, E.J. Galvez, P.R. Crawford, H.I. Sztul, M.J. Pysher, P.J. Haglin, R.E. Williams (Colgate University)
Description Optical beams in high-order modes can propagate containing a phase singularity or vortex in their profile. This singularity gives rise to "orbital" angular momentum, in addition to the well-known spin angular momentum associated to circular polarization. A new geometric (Berry) phase associated with these optical beams, which manifests as a topological phase shift in the light wave, was measured by transforming optical modes in a space where the light acquires topological phases.
Faculty Enrique Galvez is a professor in the Department of Physics and Astronomy.
Student H.I. Sztul worked on this project in the summer after his second year and in the spring semesters of his junior and senior years and is currently in graduate school at City College of New York. P.J. Haglin worked in the summer after his junior year and currently teaches high school physics. P.R. Crawford and M.J. Pysher did this work in the summer after their second year. M.J. Pysher will go to graduate school at University of Virginia next year.
Fund The work was funded by Research Corporation, NSF-RUI, and Colgate University.
 
( 86 )   Recorded at: 9/8/2003      
Title Incorporation of a Fluoroscopic X-ray Modality in a Small Animal Imaging System
Journal IEEE Transactions on Nuclear Science, 2003, 50, 333-338, M. S. Saha, E. L. Bradley, P. Brewer, K. K. Gleason, B. Kross, S. Majewski, V. Popov, J. Qian, A. Ranck, K. Smith, M. F. Smith, A. G. Weisenberger, R. Wojcik, R. E. Welsh. (College of William and Mary)
Description We describe the incorporation of a small fluoroscopic x-ray device into our system for nuclear imaging of small animals. This imaging project makes use primarily of the relatively long-lived (60 days) isotope Iodine-125 which is available commercially attached to a variety of interesting biological ligands. The imaging system is thus ideally suited to use in research laboratories that are not near a source of the short-lived isotopes often used in other imaging systems. The paper also describes a test project in which the blocking of thyroid uptake of radioactive iodine is effected by ingestion of normal potassium iodide.
Faculty William and Mary faculty members included Margaret Saha, biology; Eric Bradley, biology; Robert Welsh, physics.
Student Undergraduate authors in physics included Paul Brewer, Kevin Smith and Amoreena Ranck. Both Brewer and Smith are planning graduate work. Ranck is attending medical school at the University of Virginia. The undergraduate author in biology was Kris Gleason who is now a graduate student in biology at William and Mary.
Fund The work was funded by the Thomas F. and Kate Miller Jeffress Memorial Trust, the American Diabetes Association, the Department of Energy, HHMI, NSF, and the Commonwealth Health Research Board.
 
( 87 )   Recorded at: 8/27/2003      
Title Temperature Dependence of Nonradiative Recombination in Low-band Gap InGaAs/InAsP Double Heterostructures Grown on InP Substrates
Journal Journal of Applied Physics, 2003, 94, 1738-1743, Tim Gfroerer, Patten Priestley, Malu Fairley, and Mark Wanlass (Davidson College)
Description Temperature dependence is used to discern the mechanisms for nonradiative recombination in InGaAs/InAsP heterostructures. We find that defect-related recombination generally increases slowly with temperature due to wider carrier diffusion, which augments the capture rate, and thermally activated escape, which reduces the occupation of shallow traps. The band gap and temperature dependence of Auger recombination demonstrate that the conduction to heavy hole band/splitoff to heavy hole band mechanism dominates in undoped low-band gap InGaAs. Our analysis yields the first experimental determination of the spin-orbit valence split-off band effective mass in this alloy.
Faculty Tim Gfroerer is an assistant professor of physics at Davidson College.
Student Mark Wanlass is a crystal grower at the National Renewable Energy Laboratory. Patten Priestley and Malu Fairley participated in this research during the summer of 2001 and Patten continued working on the project the following summer. Malu graduated from Spelman College and is now employed as a high school librarian. Patten graduated from Davidson College and is working as a high school physics teacher.
Fund The research was supported by grants from Research Corporation and the ACS-PRF.
 
( 88 )   Recorded at: 8/27/2003      
Title Observed Landau Structure in Photodetachment from Trapped O-
Journal Physical Review A, 2003, 67, 062721-1 to 062721-5, John N. Yukich, Diana M. Pendergrast (Davidson College)
Description We observed a frequency-domain photodetachment spectrum from O- in a magnetic field. The observed structure showed clear modulation of the relative detachment cross section due to the departing electron's discrete cyclotron levels. The results were shown to corroborate experimental results from a previous time-domain investigation, and a new value for the O- electron affinity was reported.
Faculty John Yukich is an assistant professor of physics.
Student Diana Pendergrast participated in this research as part of an independent study in her senior year, and is now pursuing research in renewable energy sources.
Fund This research was supported by Research Corporation.
 
( 89 )   Recorded at: 8/20/2003      
Title Hypervelocity Microparticle Impact Studies Using a Novel Cosmic Dust Mass Spectrometer
Journal Journal of Geophysical Research, 2003, 108, E5, 5038, doi:10.1029/2002JE001947, Heidi L. K. Manning, Carl L. Bailey, and James E. Farnsworth, Daniel E. Austin, Ronald L. Grimm, Thomas J. Ahrens, J. L. Beauchamp (Concordia College)
Description Micron-sized iron and copper particles accelerated to 2-20 km/s in a 2 MV van de Graaff electrostatic accelerator were used to test the performance of our recently developed cosmic dust mass spectrometer. This compact in situ dust analyzer, known as the Dustbuster, is designed to determine the elemental composition of cosmic dust particles through impact ionization and subsequent time-of-flight mass spectrometry.
Faculty Heidi Manning is an assistant professor and Carl Bailey a professor emeritus of physics at Concordia College. Ronald Grimm and J. L. Beauchamp are in the Division of Chemistry and Chemical Engineering at the California Institute of Technology. Thomas Ahrens is in the Division of Geological and Planetary Sciences at the California Institute of Technology.
Student James Farnsworth participated in this work as a summer project the summer after his sophomore year at Concordia College. Daniel Austin works for Sandia National Laboratories.
Fund The work was supported by the Minnesota Space Grant Consortium.
 
( 90 )   Recorded at: 8/20/2003      
Title Molecular Dynamics Simulation of Reactive Compatibilization of Polymer Blends
Journal Macromolecules, 2003, 36, 229-237, Chuck Yeung, Kim Herrmann (The Pennsylvania State University at Erie)
Description Polymer blends can be compatibilized by placing complementary functional groups at the end of the polymers. Molecular dynamics simulations of reactive compatibilization of polymer blends are performed for a wide range of chain lengths and densities of reactive groups. The density of the copolymer layer as a function of time was studied and different regimes predicted theoretically were observed. A model to study the limit of very dilute reactive density was introduced. The results agree with theoretical predictions at this limit.
Faculty Chuck Yeung is an associate professor of physics.
Student Kim Herrmann participated in this project for three years beginning in the summer after her freshman year and is presently a graduate student in astronomy and astrophysics at Pennsylvania State University at University Park.
Fund The research was supported through a NSF-RUI grant and funds from Penn State Erie.
 
( 91 )   Recorded at: 5/27/2003      
Title Selective Photothermal Interaction Using an 805-nm Diode Laser and Indocyanine Green in Gel Phantom and Chicken Breast Tissue
Journal Lasers in Medical Science, 2002, 17, 272-279, Liu, V. G., T. M. Cowan, S-W. Jeong (University of Central Oklahoma/Oregon Graduate Institute)
Description Selective photothermal effect was investigated using gel phantom and chicken breast tissue. An 805-nm diode laser and indocyanine green (ICG) were used. An ICG-containing gelatin phantom was constructed to simulate targeted tumor tissue. The target gel was buried inside chicken breast tissue and the tissue-gel construct was irradiated by the laser. Temperatures at different locations in the construct were measured during the laser irradiation. For comparison, the thermal effect of an Nd:YAG laser on the tissue-gel construct was also investigated. Selective heating of target gel containing 0.27% ICG and buried 1 cm below the chicken tissue surface was achieved with the 805-nm diode laser using a power of 0.85 watt and beam radius of 1 cm. The target gel experienced a temperature increase of more then six degrees Celsius while the surrounding chicken breast tissue experienced only a minor temperature increase. The feasibility of this experimental set-up has been shown. It could be used in the future to optimize treatment parameters such as laser power, laser beam radius, and dye concentration.
Faculty Steven Jacques is a professor at the Oregon Graduate Institute. Evan Lemley and Wei Chen are faculty members at the University of Central Oklahoma.
Student Vincent Guangyu Liu and Thomas Cowan participated in the research during the summer. Liu is currently at the Johns Hopkins University and Cowan at the Medical School of the Case Western Reserve University. Sang-Won Jeong is a graduate student, working toward his Master¹s degree in Engineering Physics at the University of Central Oklahoma.
Fund The research was funded by grants from the University of Central Oklahoma and the Oklahoma Center for Advancement of Science and Technology.
 
( 92 )   Recorded at: 5/27/2003      
Title Search for Common Characteristics in the Glow Curves of Quartz of Various Origins
Journal Radiation Protection Dosimetry, 2002, 100, 373-376, V. Pagonis, E. Tatsis, G. Kitis, C. Drupieski. (McDaniel College)
Description The thermoluminescence properties of 13 different types of natural and synthetic quartz have been studied, in order to identify common characteristics of importance to archeological and geological dating. Several common characteristics in the glow curves and the kinetic parameters of the materials are identified, both for annealed and non-annealed samples. The results of this paper will be used to improve the dating techniques for archaeological materials.
Faculty Vasilis Pagonis is professor of physics.
Student Christopher Drupieski participated in this research the summer of his sophomore year, and will continue it as an honors senior project. He is currently finishing his junior year at McDaniel College.
Fund The research was supported by McDaniel College.
 
( 93 )   Recorded at: 5/27/2003      
Title Self-Propagating Reaction Induced by Ball Milling in a Mixture of Cu2O and Al Powders
Journal Metallurgical and Materials Transactions A, 2002, 33A, 3521-3526, A. Bakhshai, R. Pragani, L. Takacs (Goucher College)
Description The mechanochemical reduction of Cu2O with Al was induced via ball milling. A self-propagating reaction took place in two distinctly different ways. If the mass of the reactant powder mixture was large enough, ignition happened within a few seconds after starting the mill. Neither the activation of the reactants nor the formation of a powder layer covering the surfaces of the milling tools were necessary. If the mass of the charge is smaller than a critical value, the self-propagating reaction is ignited only after several minutes of mechanical activation.
Faculty Ali Bakhshai is a professor of physics, Lasso Takacs is an associate professor of physics at UMBC.
Student Rajan Pragani is currently enrolled as a senior at Goucher College and intends to enter graduate school next year. Rajan participated in this research as a full-time research assistant during the summer.
Fund This research was supported by Goucher College.
 
( 94 )   Recorded at: 5/27/2003      
Title Origin of Correlated Electron Emission in Double Ionization of Atoms
Journal Physical Review A, 2002, 66, 1-4, S.L Haan, P.S. Wheeler, R. Panfili, J.H. Eberly (Calvin College)
Description We investigated the mechanism of double ionization of atoms by intense laser fields. The paper provides a numerical solution of the time-dependent Schroedinger Equation for a simplified model of the helium atom and introduces a new technique of "quantum masking." The paper confirms that the double ionization originates primarily from recollision, a process in which one electron is ionized but then returns to the core for energy sharing with the second electron. We also showed that recollision events that occur in opposition to the laser force (i.e., while the returning electron is being slowed down) are most important.
Faculty Stan Haan is professor of physics and Chair of the Physics and Astronomy Department.
Student R. Panfili was a graduate student at the University of Rochester, and J.H. Eberly a Professor of Physics at UR. P. Scott Wheeler participated fulltime in this research during summer 2000 after his junior year at Calvin. Scott is presently living in Hamburg, Germany, and is employed in the computer industry.
Fund This research was funded through a NSF RUI Grant.
 
( 95 )   Recorded at: 5/16/2003      
Title Enhanced Optical Polarization Anisotropy in Quantum Wells Under Anisotropic Tensile Strain
Journal IEEE Journal of Quantum Electronics, 2003, 39, 401-403, Mark L. Biermann, James Diaz-Barriga, W. S. Rabinovich (U. S. Naval Academy)
Description Anisotropic in-plane strain in quantum wells leads to a polarization-based optical anisotropy in opto-electronic devices, which employ quantum wells. Previous work has focused on quantum wells under compressive, anisotropic strain. Systems under tensile, anisotropic strain were analyzed and exhibited optical polarization anisotropies 2 to 5 times larger than arise for the same magnitude of compressive strain. The relationship between the strain and polarization anisotropies is much more complicated in the tensile strain case than in the compressive strain case.
Faculty Mark Biermann is an assistant professor of physics.
Student W. S. Rabinovich is a research physicist at the Naval Research Laboratory. James Diaz-Barriga participated in this research as a part of an independent research course during his senior year, and during the summer after his graduation. He is currently a Surface Warfare Officer in the U. S. Navy.
Fund The research was supported by the Office of Naval Research.
 
( 96 )   Recorded at: 5/16/2003      
Title Effect of Optical Feedback on Beam Patterns of a Photorefractive Oscillator
Journal Optics Communications, 2003, 216, 209-215, Hong Lin, Endri Trajani, Ryan C. Williamson (Bates College)
Description The output of a unidirectional photorefractive oscillator with a stabilized cavity length is sent to a feedback arm in which two lenses form a 4f system. Spatial filtering is implemented in the Fourier plane of the feedback arm. The phase shift of the feedback signal is changed by varying the voltage applied on a piezo-driven mirror. This phase sensitive feedback is used to select beam patterns belonging to the same oscillating family or to drive the oscillator from one family to another.
Faculty Hong Lin is a professor of physics.
Student Endri Trajani participated in this research for two summers and then continued it as an honors thesis. Ryan Williamson took part in the research the summer after his junior year. Both students will graduate this May.
Fund The research was supported through a NSF-RUI grant.
 
( 97 )   Recorded at: 10/21/2002      
Title New Short-Wavelength Laser Emissions From Optically Pumped 13CD3OD
Journal IEEE Journal of Quantum Electronics, 2002, 38, 429-431, M. Jackson, H. Hockel, M. Lauters, E. C. C. Vasconcellos, M. D. Allen, K. M. Evenson (University of Wisconsin – La Crosse)
Description A recently designed optically pumped molecular laser system was used to discover fifteen new laser emissions from 57.5 to 135.2 nm using the 13CD3OD methanol isotope. The frequencies of twelve optically pumped laser emissions from this methanol isotope for lines ranging from 65.7 to 151.8 nm were measured using the three-laser heterodyne technique and were reported with fractional uncertainties up to 2 x 10-7 along with their polarization relative to the CO2 pump.
Faculty Michael Jackson is an assistant professor of physics.
Student Heidi Hockel and Michael Lauters performed research during their junior and senior years and are currently pursuing their Ph.D. at the School of Optics/CREOL, University of Central Florida and the Optical Sciences Center, University of Arizona, respectively.
Fund This work was supported with funding from the NSF (CRIF and RUI), the Wisconsin Space Grant Consortium/NASA, Sigma Xi and the University of Wisconsin-La Crosse.
 
( 98 )   Recorded at: 10/21/2002      
Title Defect-related Density of States in Low-bandgap InGaAs/InAsP Double Heterostructures Grown on InP Substrates
Journal Applied Physics Letters, 2002, 80, 4570-4572, T.H. Gfroerer, L.P. Priestley, F.E. Weindruch, M.W. Wanlass (Davidson College)
Description Novel semiconductor structures that may be useful for future photovoltaic cells were found to have superior performance even when severe lattice-mismatch exists between the substrate and the device. Excitation-dependent radiative efficiency measurements on these structures contain a unique feature that cannot be explained by simple defect-related recombination models. Analysis reveals that this special behavior can be attributed to a redistribution of defect levels toward the band edges where they are less likely to facilitate nonradiative recombination.
Faculty Tim Gfroerer is an assistant professor of physics.
Student Emmett Weindruch worked on a summer research assistantship and now teaches high school physics. Patten Priestley worked during the summer and continues the project as a rising senior. Mark Wanlass, Infrared Photovoltaic Materials and Devices Team Leader at the National Renewable Energy Laboratory, provided the samples for this study.
Fund The work was supported by Research Corporation and ACS-PRF.
 
( 99 )   Recorded at: 10/21/2002      
Title Quasiparticle Thermal Conductivities in a Type-II Superconductor at High Magnetic Fields
Journal Physical Review B, 2002, 66, 014517, 1-7, Sasha Dukan, T. Paul Powell, Zlatko Tesanovic (Goucher College)
Description This theoretical and numerical work examines the quasiparticle contribution to the longitudinal thermal transport of an extreme type-II superconductor in a high magnetic field and at low temperatures. The agreement with recent experimental data on borocarbide superconductor LuNi2B2C is excellent.
Faculty Sasha Dukan is an assistant professor of physics. Zlatko Tesanovic is a Professor of Physics at Johns Hopkins University.
Student T. Paul Powell conducted a computational part of this physics project during the summer after his sophomore year. He developed mathematical models and C++ computer programs for the project. He is now a junior math major.
Fund This work was supported by grants from Research Corporation and NSF.
 
( 100 )   Recorded at: 10/1/2002      
Title Negative Group Velocity Pulse Tunneling Through a Coaxial Photonic Crystal
Journal Applied Physics Letters, 2002, 81 2127-2129, J. N. Munday, W. M. Robertson (Middle Tennessee State University)
Description An easily configurable experimental system was constructed in which negative group velocity tunneling of electrical pulses can be studied. Negative group velocity corresponds to the case in which the peak of a tunneled pulse exits before the peak of the incident pulse has entered the sample. Experiments demonstrated that the tunneling occurs through the forbidden transmission region of a quarter-wavelength interference filter created from alternating segments of two different impedance coaxial cables.
Faculty Bill Robertson is a member of the physics and astronomy department.
Student Jeremy worked on this project one semester and is currently in his senior year at MTSU.
 
( 101 )   Recorded at: 10/1/2002      
Title Gravitational Lensing by Charged Black Holes
Journal General Relativity and Gravitation, 2002, 34, 1221-1230, Sharmanthie Fernando, Sean Roberts (Northern Kentucky University)
Description Black Holes are one of the most profound predictions of Einstein's general theory of relativity. There is strong evidence that the center of most galaxies host massive black holes. The phenomenon of the deflection of light due to a strong gravitational field is referred to as gravitational lensing. Here we formulated the lensing effects of a spherically electrically charged black hole using thing lens equations. The charged black hole leads to three images and could lead to three Einstein rings provided the parameters such as the mass, charge and the distances satisfy certain constraints. We have computed the exact positions of images and magnification properties for a super-massive black hole with the electric charge.
Faculty
Student
 
( 102 )   Recorded at: 10/1/2002      
Title Large Force Fluctuations in Flowing Granular Medium
Journal Physical Review Letters, 2002, 89, 045501-1, E. Longhi, N. Easwar (Smith College) and N. Menon (University of Massachusetts)
Description Force fluctuations at the boundary of a flowing granular material were studied using a hopper that allows 3mm steel balls to flow under gravity in a 2-dimensional geometry. The opening at the bottom could be varied from ~3 to ~16 ball diameters, which corresponds to increasing flow rates from about 10cm/s to 140cm/s. We found that the forces on the walls are mainly impulsive at all flow velocities. The probability distribution of impulses decays exponentially at large forces, as do the forces in a static granular medium. This feature could suggest the presence of dynamic force chains in flow. At lower flow velocities, the approach to jamming was not evident in the impulse distributions but rather in the dynamic quantity represented by the time interval between collisions.
Faculty
Student
 
( 103 )   Recorded at: 10/1/2002      
Title Factorized Time Correlation Diagram Analysis of Paired Causal Systems Excited by Twin Stochastic Driving Functions
Journal Physical Review E, 2002, 65, 1-12, Daniel P. Biebighauser, Daniel B. Turner, Darin J. Ulness (Concordia College)
Description The properties and mathematical structure of factorized time correlation (FTC) diagram analysis in a general context was examined. The goal is to extract general principles and analytic behavior that are not tied to any particular phenomenon in physics. It is hoped that this will provide a basis for expanded use of FTC diagram analysis beyond its current employment in the study of noisy light-based nonlinear optical spectroscopy. Furthermore, the concept of indirect correlation in a two-channel system driven by twin stationary circular Gaussian stochastic inputs is defined and discussed both analytically and through FTC diagram analysis.
Faculty
Student
 
( 104 )   Recorded at: 10/1/2002      
Title New Short-Wavelength Laser Emissions From Partially Deuterated Methanol Isotopes
Journal Applied Physics B, 2002, 74, 613-614, K. M. Evenson, Q. Sanford, C. Smith, J. Sullivan, D. Sutton, E. Vershure, M. Jackson (University of Wisconsin - La Crosse)
Description The partially deuterated isotopes of methanol, CHD2OH and CH2DOH, have been reinvestigated as sources of far-infrared (FIR) laser emissions using an optically pumped molecular laser (OPML) system recently designed for wavelengths below 150 mm. With this system, ten FIR laser emissions from these isotopes ranging from 32.8 to 174.6 mm have been discovered. This includes the discovery of the shortest known OPML emission from CHD2OH at 32.8 mm. Polarizations for three previously observed FIR laser lines from CHD2OH were measured for the first time.
Faculty Michael Jackson is an assistant professor of physics.
Student Quinn Sanford and John Sullivan are graduate students at the University of Arizona. Eric Vershure is a graduate student at the University of Dayton. Dan Sutton and Christian Smith will be entering their senior year at UW-L.
Fund This work was supported by NSF (CRIF and RUI), the Wisconsin Space Grant Consortium/NASA, Sigma Xi and the University of Wisconsin-La Crosse.
 
( 105 )   Recorded at: 10/1/2002      
Title Calculation of the Positronium Hyperfine Interval using the Bethe-Salpeter Formalism
Journal Physical Review A, 2002, 65, 42103 (1-32), Gregory S. Adkins, Richard N. Fell, Plamen M. Mitrikov (Franklin & Marshall College)
Description We used a variation of the Bethe-Salpeter equation to complete the calculation of the one-photon annihilation contribution to the hyperfine interval of positronium of order m*alpha^6. Our results are in accord with a quite different calculation independently done using an effective field theory approach. This completes the evaluation of all the m*alpha^6 terms. We give the total theoretical value for this interval and compare with experiment.
Faculty Greg Adkins is a professor of physics.
Student Richard Fell is at Brandeis University. Plamen Mitrikov was an undergraduate student at Franklin and Marshall and participated in this project during two school years and two summers. He is currently working for a securities firm.
Fund This work was supported by NSF and F&M.
 
( 106 )   Recorded at: 10/1/2002      
Title Breaking the Sound Barrier: Tunneling of Acoustic Waves Through the Forbidden Transmission Region of a One-dimensional Acoustic Band Gap
Journal American Journal of Physics, 2002, 70, 689-693, W. M. Robertson, J. Ash, J. M. McGaugh. (Middle Tennessee State University)
Description The tunneling of audio pulses through the forbidden region zone of an acoustic band gap array was demonstrated. The band gap was created in a waveguide with a periodically spaced series of dangling side branches. Tunneling pulses, whose frequency content lay completely within the forbidden transmission region, were used to explore the concepts of tunneling time and group velocity. The group velocity of the tunneling pulse was shown to be considerably larger than the speed of sound.
Faculty Bill Robertson is a member of the physics and astronomy department.
Student John McGaugh worked on this research for one summer and is completing his studies at MTSU. John Ash worked on the project for one summer and is in graduate school at Vanderbilt University.
Fund The work was supported by NSF and MTSU.
 
( 107 )   Recorded at: 6/26/2002      
Title Brownian Motion Using Video Capture
Journal European Journal of Physics, 2002, 23, 249-253, K. Forinash, Reese Salmon, Candice Robbins. (Indiana Southeast University)
Description A modern version of Jean Perrin's famous 1908 verification of Einstein's 1905 calculation of Brownian motion (the random motion of tiny particles seen under a microscope) is provided. Einstein's paper along with Perrin's experimental verification consitute the foundations of the modern discipline of statistical mechanics and was considered to be the first direct proof of the physical existence of molecules. Our version of this important experiment simplifies and modernizes Perrin's work by using video techniques and computer video analysis.
Faculty K. Forinash is a professor of Physics.
Student Reese Salmon, a biology major and physics minor, and Candice Robbins, a secondary science education major, undertook the project in a junior level lab course. Candice is now teaching high school chemistry and biology.
 
( 108 )   Recorded at: 6/26/2002      
Title Effect of Collagen and Mineral Content on the High Frequency Ultrasonic Properties of Human Cancellous Bone
Journal Osteoporosis International, 2002, 13, 26-32, B. K. Hoffmeister, S. A. Whitten, S. C. Kaste, J. Y. Rho. (Rhodes College)
Description Certain diseases such as osteoporosis or osteogenesis imperfecta (brittle bone disease) can affect the collagen and/or mineral content of bone. Ultrasonic techniques may offer a noninvasive means to detect and monitor these diseases. This study investigated the sensitivity of three ultrasonic parameters to changes in the collagen and mineral content of human cancellous bone.
Faculty B. K. Hoffmeister is a member of the Physics Department.
Student Andy Whitten worked on the project through his junior and senior years, including the summer, and is currently employed.
Fund The work was primarily supported by Rhodes College.
 
( 109 )   Recorded at: 6/26/2002      
Title Sensitivity to the KARMEN Timing Anomaly at MiniBooNE
Journal Physical Review D, 2002, 077701, 1-3, Sarah C. Case, Sally Koutsoliotas, Melanie L. Novak. (Bucknell University)
Description Results from the KARMEN neutrino-nucleon experiment at the Rutherford Appleton Laboratory revealed an anomaly in the timing spectrum of neutrino interactions. A possible explanation of these excess events is the decay of a massive, neutral particle, not predicted by the standard model of particle physics. An investigation of the sensitivity of the MiniBooNE experiment at Fermi National Accelerator Laboratory to this particle is presented. It was shown that MiniBooNE will be able to investigate an unexplored region of the KARMEN signal.
Faculty Sally Koutsoliotas is associate professor of physics.
Student Sarah Case, currently a graduate student in physics at the University of Chicago, performed this work both during the summer and academic year as a Columbia University undergraduate. Melanie Novak is a junior physics major at Bucknell University, and performed this work during a summer internship.
Fund This work was supported by the NSF-REU and NSF-RUI programs.
 
( 110 )   Recorded at: 6/26/2002      
Title Phase Transitions in a Nematic Binary Mixture
Journal Journal of Chemical Physics, 2002, 116, 2213-2218, A., Christine Rauch, Shila Garg, Donald T. Jacobs. (The College of Wooster)
Description Mixtures of nematic liquid crystals with dissimilar dielectric anisotropies but similar phase properties were studied. Using light scattering and microscopy, the phase boundaries and transition widths of mixtures of 4'-n-pentyl-4-cyanobiphenyl (5CB) and 4'-methoxybenzylidene-4-butylaniline (MBBA) were established. In addition to the isotropic-nematic transition, there is a second induced phase for certain concentrations, which we conclude is an induced smectic B phase. Recent theoretical works provide a model for nematic to induced smectic A transition. We conclude that there is a possibility of strong interaction between the two mesogens that produces the smectic B phase.
Faculty Shila Garg and Don Jacobs are in the Physics Department.
Student Christine Rauch conducted the work as her senior independent study project, and has spent the past two years as a community environmental education volunteer with Peace Corps in Panama.
Fund This project was funded by an NSF-RUI grant and the College of Wooster.
 
( 111 )   Recorded at: 3/25/2002      
Title Electron Scattering from the 2p53s configuration of Neon
Journal Differential, in Correlations, Polarization, and Ionization in Atomic Systems, Proceedings of the International Symposium on (e,2e), Double Photoionization and Related Topics, Ed. Don H. Madison and Michael Schulz, 2001, 162-165, M. A. Khakoo, J. Wrkich and M. Larsen. (California State University, Fullerton)
Description High resolution electron scattering data from neon was unfolded and analyzed into cross sections for the individual levels constituting the 2p53s configuration of neon. In addition, the method of mixtures was used with atomic hydrogen to obtain high accuracy absolute summed cross-sections for the 2p53s configuration of neon.
Faculty Murtadha Khakoo is a member of the Physics Department.
Student J. Wrkich and M. Larsen carried out this work as independent study projects and through an REU program. J. Wrkich is now studying patent law at William and Mary. M. Larsen is a graduate student at the University of Wisconsin-Madison.
Fund The work was funded through NSF-RUI grants.
 
( 112 )   Recorded at: 3/25/2002      
Title Proton Impact Excitation of SO2, Journal of Geophysical Research
Journal Space Physics, 2001, 106, 26147-25154, Jennifer E. Kiehling, Thomas F. Ammirati, Matthew D. Moore, Michael N. Monce, Elizabeth F. Hansel. (Connecticut College)
Description Because of the interest in atomic emissions observed from the Io plasma torus, we have investigated the spectrum produced by proton impact on SO2 in the wavelength region of 380-800nm. The proton energy was varied from 50 to 225 keV. The spectrum shows numerous S, O, S+, and O+ lines as well as a strong Balmer series. Preliminary absolute emission cross-sections have been measured for the most dominant line in the spectrum, an oxygen triplet at 777nm.
Faculty Michael Monce and Thomas Ammirati are Professors of Physics.
Student Jennifer Kiehling, who now works in industry, undertook the work as an honors thesis. Matthew Moore also contributed optics design while a student and now works for W. Barr Associates. Elizabeth Hansel is currently a senior physics major at Connecticut College.
 
( 113 )   Recorded at: 3/25/2002      
Title Supernumerary spacings of rainbows produced by an elliptical cross-section cylinder II: Experiment
Journal Applied Optics, 2001, 40, 2535-45, Charles L. Adler, David Phipps, Kirk W. Saunders, Justin K. Nash. (Saint Mary’s College of Maryland)
Description A problem in inverse scattering: can the shape and composition of an object be determined by examining the light scattered by it?, was examined. The particular problem we studied: the spacing of the interference fringes produced when light is rainbow scattered by a cylinder with a nearly-circular cross-section, had never been investigated. We found that, for reasons still unknown, the spacing of the interference pattern varied chaotically when the cylinder was rotated about its center.
Faculty Charles Adler is an Assistant Professor of Physics.
Student David Phipps and Justin Nash are currently working at the Naval Research Laboratory. Kirk Saunders is still a student at SMC. The work was completed by the students as summer research and senior thesis projects.
Fund The work was supported by an NSF-RUI grant and funds from St. Mary’s College of Maryland.
 
( 114 )   Recorded at: 3/25/2002      
Title Testing Gravity in Space and at Ultrashort Distances
Journal Classical and Quantum Gravity, 2001, 18, 2427-2434, E. Fischbach, S. W. Howell, Suniti Karunatillake, Dennis. E. Krause, R. Reifenberger, Michael West. (Wabash College)
Description The equivalence principle is applied to the weak interaction using the proposed Satellite Test of the Equivalence Principle (STEP) experiment, and a search for new short range forces using an atomic force microscope (AFM). Suniti and Michael calculated the limits on new forces that could be extracted from an AFM experiment performed at Purdue. The calculations show that the limits obtained are comparable to the best current limits in the 1??4 nanometer range.
Faculty Dennis Krause is an Assistant Professor of Physics.
Student Suniti and Michael performed this work as summer interns at Wabash College. Suniti is now a graduate student in Physics at Cornell University, and Michael is currently a senior physics major.
Fund Salary and housing was provided by Wabash College.
 
( 115 )   Recorded at: 3/25/2002      
Title Maximum-entropy muon-spin-rotation study of PrxY1-xBCO
Journal Physica C, 2001, 364-365, 582-586, Helen H. Aslanian, Magnolia Tun, Margie M. Abdelrazek, Sean X. Cavanaugh, Carolus Boekema (San Jose State University)
Description Muon-spin-rotation data of PrxY1-xBa2Cu3O7-d (PrxY1-xBCO) recorded at room temperature have been analyzed by a Maximum-Entropy technique. For different Pr doping, the obtained magnetic field distributions show distinct differences. The field distributions have been fitted using two Lorentzians, affirming trends seen for the (x < 0.5) superconductors. These trends are consistent with increasing Pr presence in BaO layers. Well below Tc superconductivity may occur in the CuO-chain layers (besides the CuO2 planes) in these cuprates.
Faculty Carolus Boekema is a Professor of Physics.
Student Helen Aslanian and Magnolia Tun participated in an REU program at SJSU and the National High Magnetic Field. Helen is now a graduate student at UCLA. Magnolia is employed. Sean X. Cavanaugh participated in an REU project at SJSU.
Fund The work was supported through an NSF-REU award, LANL-DOE grant, and by the SJSU College of Science.
 
( 116 )   Recorded at: 3/25/2002      
Title A Statistical Study of Transient Event Motion at Geosynchronous Orbit
Journal Journal of Geophysical Research, 2001, 106, 21, 217-21,229, Jeff Sanny, David Berube, David G. Sibeck. (Loyola Marymount University)
Description This research was a study of the transfer of energy from the solar wind to the earth's magnetosphere. This transfer is commonly exhibited by "transient events", brief fluctuations in magnetic and plasma parameters commonly observed by spacecraft in the vicinity of the magnetopause. Through a cross-correlation analysis of a large number of observations from two spacecraft along with solar wind data, we discovered that most transient events move antisunward at speeds of hundreds of kilometers per second and that they are caused by pressure pulses originating in the bow shock region. The study of such events is important because they are an integral part of the sun?earth connection, a primary focus of NASA's space program.
Faculty Jeff Sanny is a member of the Physics Department. David Sibeck is a member of the Applied Physics Laboratory at Johns Hopkins University.
Student David Berube worked on this research for two summers. He is currently a Ph. D. student in the Department of Earth and Space Science at the University of California, Los Angeles.
Fund The work was supported through a grant from NASA.
 
( 117 )   Recorded at: 3/25/2002      
Title Turbulent Conductivity Measurements in a Spherical Liquid Sodium Flow
Journal Physics Review Letters, 2001, 86, 2794-2797, Amy B. Reighard, Michael. R. Brown. (Swarthmore College)
Description The research investigated aspects of solar magnetism and heating of the solar corona. The paper reports laboratory measurements that pertain to these solar and astrophysical problems.
Faculty Michael Brown is an Associate Professor of Physics.
Student Amy Reighard did the research for her senior thesis project. Amy is now at graduate student at the University of Michigan.
Fund The work was supported through grants from NSF and the Department of Energy.
 
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