Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Institution
-
- University of Massachusetts Amherst (21)
- Embry-Riddle Aeronautical University (19)
- University of Texas Rio Grande Valley (14)
- Brigham Young University (12)
- Clemson University (12)
-
- Dartmouth College (11)
- Tennessee State University (10)
- University of Kentucky (7)
- Florida Institute of Technology (6)
- University of New Hampshire (6)
- Munster Technological University (4)
- Selected Works (4)
- University of South Carolina (4)
- Old Dominion University (3)
- SelectedWorks (3)
- Swarthmore College (3)
- Kennesaw State University (2)
- San Jose State University (2)
- Smith College (2)
- Technological University Dublin (2)
- University of Northern Iowa (2)
- University of Tennessee, Knoxville (2)
- Andrews University (1)
- City University of New York (CUNY) (1)
- Claremont Colleges (1)
- East Tennessee State University (1)
- Eastern Illinois University (1)
- Illinois Math and Science Academy (1)
- The University of San Francisco (1)
- University of Arkansas, Fayetteville (1)
- Keyword
-
- White dwarfs (8)
- Spectroscopic binaries (6)
- 1.3 PHYSICAL SCIENCES (4)
- Astronomy (4)
- Pdf (4)
-
- Stars: abundances (4)
- Acoustic (3)
- Astronautics (3)
- Department of physical sciences (3)
- Extinction (3)
- Gamma rays: observations (3)
- Magnetospheric physics (3)
- Science (3)
- Space plasma physics (3)
- Stars: evolution (3)
- Starspots (3)
- Stellar activity (3)
- Supernova remnants (3)
- Technology (3)
- Atomic Processes (2)
- Atomic data (2)
- Circumstellar matter (2)
- Cosmic Rays (2)
- Cosmology (2)
- Diffusion (2)
- Dust (2)
- Emission line (2)
- Galaxies (2)
- Galaxies : formation (2)
- Galaxies: Active (2)
- Publication
-
- Publications (30)
- Astronomy Department Faculty Publication Series (19)
- Physics and Astronomy Faculty Publications and Presentations (14)
- Dartmouth Scholarship (11)
- Information Systems and Engineering Management Research Publications (10)
-
- Faculty Publications (7)
- Physics and Astronomy Faculty Publications (7)
- Aerospace, Physics, and Space Science Faculty Publications (6)
- Space Science Center (6)
- Theses and Dissertations (6)
- Journal of the South Carolina Academy of Science (4)
- John Cannon (3)
- Physical Sciences Publications (3)
- Physics & Astronomy Faculty Works (3)
- Richard Ignace (3)
- Astronomy: Faculty Publications (2)
- Cross Sections (2)
- Faculty and Research Publications (2)
- Todd M. Tripp (2)
- Alejandro Garcia (1)
- All Physics Faculty Publications (1)
- Articles (1)
- Blackrock Castle Observatory Publications (1)
- ETSU Faculty Works (1)
- IMSA Great Minds Program ® (1)
- Journal of the Adventist Theological Society (1)
- Journal of the Arkansas Academy of Science (1)
- Joy Cole Corning Distinguished Leadership Lecture Series (1)
- Masters (1)
- Masters Theses (1)
- Publication Type
Articles 121 - 150 of 160
Full-Text Articles in Physical Sciences and Mathematics
Radial Gas Flows In Colliding Galaxies: Connecting Simulations And Observations, D Iono, Min Yun, Jc Mihos
Radial Gas Flows In Colliding Galaxies: Connecting Simulations And Observations, D Iono, Min Yun, Jc Mihos
Astronomy Department Faculty Publication Series
We investigate the detailed response of gas to the formation of transient and long-lived dynamical structures induced in the early stages of a disk-disk collision and identify observational signatures of radial gas inflow through a detailed examination of the collision simulation of an equal-mass bulge-dominated galaxy. Our analysis and discussion mainly focuses on the evolution of the diffuse and dense gas in the early stages of the collision, when the two disks are interacting but have not yet merged. Stars respond to the tidal interaction by forming both transient arms and long-lived m = 2 bars, but the gas response …
High-Density Molecular Gas In The Infrared-Bright Galaxy System Vv 114, D Iono, Ptp Ho, Min Yun, S Matsushita, Ab Peck, K Sakamoto
High-Density Molecular Gas In The Infrared-Bright Galaxy System Vv 114, D Iono, Ptp Ho, Min Yun, S Matsushita, Ab Peck, K Sakamoto
Astronomy Department Faculty Publication Series
The new high-resolution CO (3-2) interferometric map of the IR-bright interacting galaxy system VV 114 observed with the Submillimeter Array reveals a substantial amount of warm and dense gas in the IR-bright but optically obscured galaxy, VV 114E, and the overlap region connecting the two nuclei. A 1.8 × 1.4 kpc concentration of CO (3-2) emitting gas with a total mass of 4 × 109 M coincides with the peaks of near-IR, mid-IR, and radio continuum emission found previously by others, identifying the dense fuel for the active galactic nucleus and/or the starburst activity there. Extensive CO (2-1) emission …
Water Absorption From Line-Of-Sight Clouds Toward W49a, R Plume, Mj Kaufman, Da Neufeld, Ronald L. Snell, Dj Hollenbach, Pf Goldsmith, J Howe, Ea Bergin, Gj Melnick, F Bensch
Water Absorption From Line-Of-Sight Clouds Toward W49a, R Plume, Mj Kaufman, Da Neufeld, Ronald L. Snell, Dj Hollenbach, Pf Goldsmith, J Howe, Ea Bergin, Gj Melnick, F Bensch
Astronomy Department Faculty Publication Series
We have observed six clouds along the line of sight toward W49A using the Submillimeter Wave Astronomy Satellite and several ground-based observatories. The ortho-H2O 110 → 101 and OH (1665 and 1667 MHz) transitions are observed in absorption, whereas the low-J CO, 13CO, and C18O lines, as well as the [C I] 3P1-3P0 transition, are seen in emission. The emission lines allow us to determine the gas density (n ~ 1500-3000 cm-3) and CO column densities [N(CO) ~ 7.9 …
The Nature Of Radio Continuum Emission In The Dwarf Starburst Galaxy Ngc 625, John M. Cannon, E. D. Skillman
The Nature Of Radio Continuum Emission In The Dwarf Starburst Galaxy Ngc 625, John M. Cannon, E. D. Skillman
John Cannon
No abstract provided.
Hi Observations Of The Local Group Dwarf Wlm, D. Jackson, E. D. Skillman, John M. Cannon, S. Cote
Hi Observations Of The Local Group Dwarf Wlm, D. Jackson, E. D. Skillman, John M. Cannon, S. Cote
John Cannon
No abstract provided.
Rectification Of Thermal Fluctuations In Ideal Gases, Alejandro Garcia, P. Meurs, C. Van De Broeck
Rectification Of Thermal Fluctuations In Ideal Gases, Alejandro Garcia, P. Meurs, C. Van De Broeck
Faculty Publications
We calculate the systematic average speed of the adiabatic piston and a thermal Brownian motor, introduced by C. Van den Broeck, R. Kawai and P. Meurs [Phys. Rev. Lett. 93, 090601 (2004)], by an expansion of the Boltzmann equation and compare with the exact numerical solution.
President's Message, David J. Stroup
President's Message, David J. Stroup
Journal of the South Carolina Academy of Science
No abstract provided.
Senior Thesis Work, Corey Jansen
Senior Thesis Work, Corey Jansen
Presidential Scholars Theses (1990 – 2006)
In closing, it is important to remember, as stated earlier, that no one can prove exactly what it was that the authors of Genesis were trying to get across to us. It is valid to note, however, that the stories they were trying to get across were intended for and more properly understood by the people at that time and place. While they form the basis of many of our beliefs in Christianity, they weren't written with the realization that thousands of years later there would be great scientific discoveries that would teach us more about the world and about …
The Host Of Grb 030323 At Z=3.372: A Very High Column Density Dla System With A Low Metallicity, P. M. Vreeswijk, S. L. Ellison, C. Ledoux, R. A. M. J. Wijers, J. P. U. Fymbo, P. Møller, A. Henden, J. Hjorth, G. Masi
The Host Of Grb 030323 At Z=3.372: A Very High Column Density Dla System With A Low Metallicity, P. M. Vreeswijk, S. L. Ellison, C. Ledoux, R. A. M. J. Wijers, J. P. U. Fymbo, P. Møller, A. Henden, J. Hjorth, G. Masi
Publications
We present photometry and spectroscopy of the afterglow of GRB 030323. VLT spectra of the afterglow show damped Lyα(DLA) absorption and low- and high-ionization lines at a redshift z =3.3718 ±0.0005. The inferred neutral hy-drogen column density, log N(H i) =21.90±0.07, is larger than any (GRB- or QSO-) DLA H column density inferred directly from Lyαin absorption. From the afterglow photometry, we derive a conservative upper limit to the host-galaxy extinction: AV <0.5 mag. The iron abundance is [Fe/H] =−1.47 ±0.11, while the metallicity of the gas as measured from sulphur is [S/H] =−1.26 ±0.20. We derive an upper limit on the H2 molecular fraction of 2N(H2)/(2N(H2) +N(H i)) <∼10−6.In the Lyαtrough, a Lyαemission line is detected, which corresponds to a star-formation rate (not corrected for dust extinction) of roughly 1 Myr−1. All these results are consistent with the host galaxy of GRB 030323 consisting of a low metallicity gas with a low dust content. We detect fine-structure lines of silicon, Si*, which have never been clearly detected in QSO-DLAs; this suggests that these lines are produced in the vicinity of the GRB explosion site. Under the assumption that these fine-structure levels are populated by particle collisions, we estimate the H volume density to be nH i =102−104 cm−3.HST/ACS imaging 4 months after the burst shows an extended AB(F606W) =28.0 ±0.3 mag object at a distance of 0.14 (1 kpc) from the early afterglow location, which presumably is the host galaxy of GRB 030323.
Single-Sided Czt Strip Detectors, John R. Macri, L A. Hamel, Manuel Julien, R S. Miller, B Donmez, Mark L. Mcconnell, James M. Ryan, Mark Widholm
Single-Sided Czt Strip Detectors, John R. Macri, L A. Hamel, Manuel Julien, R S. Miller, B Donmez, Mark L. Mcconnell, James M. Ryan, Mark Widholm
Space Science Center
We report progress in the study of thick CZT strip detectors for 3-D imaging and spectroscopy and discuss two approaches to device design. Unlike double-sided strip detectors, these devices feature both row and column contacts implemented on the anode surface. This electron-only approach circumvents problems associated with poor hole transport in CZT that normally limit the thickness and energy range of double-sided strip detectors. The work includes laboratory and simulation studies aimed at developing compact, efficient, detector modules for 0.05 to 1 MeV gamma radiation measurements while minimizing the number and complexity of the electronic readout channels. These devices can …
Nucleosynthesis, Reionization, And The Mass Function Of The First Stars, Jason Tumlinson, Aparna Venkatesan, J Shull
Nucleosynthesis, Reionization, And The Mass Function Of The First Stars, Jason Tumlinson, Aparna Venkatesan, J Shull
Physics and Astronomy
We critique the hypothesisthat the first starswere very massive stars(VMSs; M > 140 M).We review the twomajor lines of evidencefor the existence ofVMSs: (1) that therelative metal abundances ofextremely metal-poor Galactic halostars show evidence ofVMS enrichment and (2)that the high electron-scatteringoptical depth (e) tothe cosmic microwave backgroundfound by the Wilkinson Microwave Anisotropy Probe(WMAP) requires VMSs forreionization in a concordanceCDM cosmology. The yieldpatterns of VMSs explodingas pair-instability supernovae areincompatible with the Fe-peakand r-process abundances inhalo stars. Models includingType II supernovae and/or"hypernovae" from zero-metallicity progenitorswith M = 840 Mcan better explain theobserved trends. We usethe …
The Faith Factor: New Testament Cosmology In Its Historical Context, Keith A. Burton
The Faith Factor: New Testament Cosmology In Its Historical Context, Keith A. Burton
Journal of the Adventist Theological Society
No abstract provided.
Table Of Contents
Journal of the South Carolina Academy of Science
No abstract provided.
Scas Officers And Council Members 2004 - 2005
Scas Officers And Council Members 2004 - 2005
Journal of the South Carolina Academy of Science
No abstract provided.
A Two Micron All Sky Survey View Of The Sagittarius Dwarf Galaxy. Ii. Swope Telescope Spectroscopy Of M Giant Stars In The Dynamically Cold Sagittarius Tidal Stream, Sr Majewski, We Kunkel, Dr Law, Rj Patterson, Aa Polak, Hj Rocha-Pinto, Jd Crane, Pm Frinchaboy, Cb Hummels, Kv Johnston, J Rhee, Mf Skrutskie, M Weinberg
A Two Micron All Sky Survey View Of The Sagittarius Dwarf Galaxy. Ii. Swope Telescope Spectroscopy Of M Giant Stars In The Dynamically Cold Sagittarius Tidal Stream, Sr Majewski, We Kunkel, Dr Law, Rj Patterson, Aa Polak, Hj Rocha-Pinto, Jd Crane, Pm Frinchaboy, Cb Hummels, Kv Johnston, J Rhee, Mf Skrutskie, M Weinberg
Astronomy Department Faculty Publication Series
We have obtained moderate resolution (~6 km s-1) spectroscopy of several hundred M giant candidates selected from Two Micron All Sky Survey photometry. Radial velocities are presented for stars mainly in the southern Galactic hemisphere, and the primary targets have Galactic positions consistent with association to the tidal tail system of the Sagittarius (Sgr) dwarf galaxy. M giant stars selected from the apparent trailing debris arm of Sgr have velocities showing a clear trend with orbital longitude, as expected from models of the orbit and destruction of Sgr. A minimum 8 kpc width of the trailing stream about the Sgr …
A Study Of Co Emission In High-Redshift Qsos Using The Owens Valley Millimeter Array, Lj Hainline, Nz Scoville, Min Yun, Dw Hawkins, Dt Frayer, Kg Isaak
A Study Of Co Emission In High-Redshift Qsos Using The Owens Valley Millimeter Array, Lj Hainline, Nz Scoville, Min Yun, Dw Hawkins, Dt Frayer, Kg Isaak
Astronomy Department Faculty Publication Series
Searches for CO emission in high-redshift objects have traditionally suffered from the accuracy of optically derived redshifts for lack of bandwidth in correlators at radio observatories. This problem has motivated the creation of the new COBRA continuum correlator with 4 GHz available bandwidth at the Owens Valley Radio Observatory Millimeter Array. Presented here are the first scientific results from COBRA. We report detections of redshifted CO (J = 3 → 2) emission in the QSOs SMM J04135+10277 and VCV J140955.5+562827, as well as a probable detection in RX J0911.4+0551. At redshifts of z = 2.846, 2.585, and 2.796, we …
Multiwavelength Observations Of The Gas-Rich Host Galaxy Of Pds 456: A New Challenge For The Ulirg-To-Qso Transition Scenario, Min Yun, Na Reddy, Nz Scoville, Dt Frayer, Ei Robson, Rpj Tilanus
Multiwavelength Observations Of The Gas-Rich Host Galaxy Of Pds 456: A New Challenge For The Ulirg-To-Qso Transition Scenario, Min Yun, Na Reddy, Nz Scoville, Dt Frayer, Ei Robson, Rpj Tilanus
Astronomy Department Faculty Publication Series
We report new K-band, radio continuum, and CO (1-0) imaging observations and 850 μm photometric observations of PDS 456, the most luminous QSO in the local universe (z < 0.3). The 06 resolution K-band image obtained using the Keck Telescope shows three compact mK ~ 16.5 (MK ~ -21) sources at a projected distance of ~10 kpc to the southwest, and the host galaxy of PDS 456 may be interacting or merging with one or more companions. Observations using the Owens Valley Radio Observatory millimeter array have revealed a narrow CO (1-0) line (FWHM = 181 km s-1 …
Radio And Far-Infrared Emission As Tracers Of Star Formation And Active Galactic Nuclei In Nearby Cluster Galaxies, Na Reddy, Min Yun
Radio And Far-Infrared Emission As Tracers Of Star Formation And Active Galactic Nuclei In Nearby Cluster Galaxies, Na Reddy, Min Yun
Astronomy Department Faculty Publication Series
We have studied the radio and far-infrared (FIR) emission from 114 galaxies in the seven nearest clusters (<100 Mpc) with prominent X-ray emission to investigate the impact of the cluster environment on the star formation and active galactic nucleus (AGN) activity in the member galaxies. The X-ray selection criterion is adopted to focus on the most massive and dynamically relaxed clusters. A large majority of cluster galaxies show an excess in radio emission over that predicted from the radio-FIR correlation, the fraction of sources with radio excess increases toward cluster cores, and the radial gradient in the FIR/radio flux ratio is a result of radio enhancement. Of the radio-excess sources, 70% are early-type galaxies, and the same fraction host an AGN. The galaxy density drops by a factor of 10 from the composite cluster center out to 1.5 Mpc, yet galaxies show no change in FIR properties over this region and show no indication of mass segregation. We have examined in detail the physical mechanisms that might impact the FIR and radio emission of cluster galaxies. While collisional heating of dust may be important for galaxies in cluster centers, it appears to have a negligible effect on the observed FIR emission for our sample galaxies. The correlations between radio and FIR luminosity and radius could be explained by magnetic compression from thermal intracluster medium pressure. We also find that simple delayed harassment cannot fully account for the observed radio, FIR, and mid-IR properties of cluster galaxies.
Dense, Ionized, And Neutral Gas Surrounding Sagittarius A*, H Shukla, Min Yun, Nz Scoville
Dense, Ionized, And Neutral Gas Surrounding Sagittarius A*, H Shukla, Min Yun, Nz Scoville
Astronomy Department Faculty Publication Series
We present high-resolution H41α hydrogen recombination line observations of the 12 (3 pc) region surrounding Sagittarius A* (Sgr A*) at 92 GHz using the Millimeter Array at the Owens Valley Radio Observatory (OVRO) with an angular resolution of 7'' × 3'' and velocity resolution of 13 km s-1. New observations of H31α, H35α, H41α, and H44α lines were obtained using the NRAO 12 m telescope, and their relative line strengths are interpreted in terms of various possible emission mechanisms. These NRAO 12 m measurements are the most extensive recombination line survey of this region to date. These OVRO …
Correction For The Flux Measurement Bias In X-Ray Source Detection, Qd Wang
Correction For The Flux Measurement Bias In X-Ray Source Detection, Qd Wang
Astronomy Department Faculty Publication Series
With a high spatial resolution imaging instrument such as the Chandra ACIS, one can confidently identify an X-ray source with only a few detected counts. The detection threshold of such sources, however, varies strongly across the field of view of the instrument. Furthermore, the low-detection counting statistics, together with a typical steep source number-flux relation, causes more intrinsically faint sources to be detected at apparently higher fluxes than the other way around. We quantify this "X-ray Eddington bias" as well as the detection threshold variation and devise simple procedures for their corrections. To illustrate our technique, we present results from …
X-Raying A2125: A Large-Scale Hierarchical Complex Of Galaxies And Hot Gas, Qd Wang, F Owen, M Ledlow
X-Raying A2125: A Large-Scale Hierarchical Complex Of Galaxies And Hot Gas, Qd Wang, F Owen, M Ledlow
Astronomy Department Faculty Publication Series
We present an 82 ks Chandra ACIS-I observation of a large-scale hierarchical complex, which consists of various clusters/groups of galaxies and low surface brightness X-ray emission at z = 0.247. This high-resolution Chandra observation allows us for the first time to separate unambiguously the X-ray contributions from discrete sources and large-scale diffuse hot gas. We detect 99 X-ray sources in a 17' × 17' field. Ten of these sources are identified as members of the complex and are mostly radio-bright. Whereas unresolved X-ray sources tend to be associated with galaxies in intermediate density environments, extended X-ray emission peak at bright …
Be Star Spectroscopy Using The Uca Fiber-Fed Spectrograph, Scott Austin
Be Star Spectroscopy Using The Uca Fiber-Fed Spectrograph, Scott Austin
Journal of the Arkansas Academy of Science
Beginning in June 2003, undergraduate students and the author have spectroscopically monitored bright Be stars using a custom built fiber-fed spectrograph attached to the UCA Observatory 11-inch Schmidt-Cassegrain telescope. We have obtained 0.8 Angstrom/pixel resolution spectra of the H-alpha line for over forty Be-Stars. Some have been observed on multiple dates in order to detect any temporal changes. Line profiles, velocities, and observed variations for some of these stars will be presented.
Riemann Tensor Of The Ambient Universe, The Dilaton, And Newton’S Constant, Rossen Ivanov, Emil Prodanov
Riemann Tensor Of The Ambient Universe, The Dilaton, And Newton’S Constant, Rossen Ivanov, Emil Prodanov
Articles
We investigate a four-dimensional world, embedded into a five-dimensional spacetime, and find the five-dimensional Riemann tensor via generalisation of the Gauss (--Codacci) equations. We then derive the generalised equations of the four-dimensional world and also show that the square of the dilaton field is equal to the Newton's constant. We find plausable constant and non-constant solutions for the dilaton. Comment: 5 pages, revtex
Measurement Of Beam-Spin Asymmetries For Π⁺ Electroproduction Above The Baryon Resonance Region, K. V. Dharmawardane, G. E. Dodge, C. E. Hyde-Wright, S. E. Kuhn, L. M. Qin, F. Sabatié, L. B. Weinstein, J. Yun, Et Al., Clas Collaboration
Measurement Of Beam-Spin Asymmetries For Π⁺ Electroproduction Above The Baryon Resonance Region, K. V. Dharmawardane, G. E. Dodge, C. E. Hyde-Wright, S. E. Kuhn, L. M. Qin, F. Sabatié, L. B. Weinstein, J. Yun, Et Al., Clas Collaboration
Physics Faculty Publications
We report the first evidence for a nonzero beam-spin azimuthal asymmetry in the electroproduction of positive pions in the deep-inelastic kinematic region. Data for the reaction e→pe'π+X have been obtained using a polarized electron beam of 4.3 GeV with the CEBAF Large Acceptance Spectrometer at the Thomas Jefferson National Accelerator Facility. The amplitude of the sin ᵠ modulation increases with the momentum of the pion relative to the virtual photon, z. In the range z = 0.5-0.8 the average amplitude is 0.038 ± 0.005 ± 0.003 for a missing mass Mx > 1.1 GeV and 0.037 …
Observations Of The Pulsating White Dwarf G 185-32, Bárbara Garcia Castanheira, Matt A. Wood
Observations Of The Pulsating White Dwarf G 185-32, Bárbara Garcia Castanheira, Matt A. Wood
Aerospace, Physics, and Space Science Faculty Publications
We observed the pulsating hydrogen atmosphere white dwarf G 185-32 with the Whole Earth Telescope in 1992. We report on a weighted Fourier transform of the data detecting 18 periodicities in its light curve. Using the Hubble Space Telescope Faint Object Spectrograph time resolved spectroscopy, and the wavelength dependence of the relative amplitudes, we identify the spherical harmonic degree (ℓ) for 14 pulsation signals. We also compare the determinations of effective temperature and surface gravity using the excited modes and atmospheric methods, obtaining Teff = 11960 ± 80 K, log g = 8.02 ± 0.04 and M = 0.617 ± …
Lisa Time-Delay Interferometry Zero-Signal Solution: Geometrical Properties, Massimo Tinto, Shane L. Larson
Lisa Time-Delay Interferometry Zero-Signal Solution: Geometrical Properties, Massimo Tinto, Shane L. Larson
All Physics Faculty Publications
Time-delay interferometry (TDI) is the data processing technique needed for generating interferometric combinations of data measured by the multiple Doppler readouts available onboard the three Laser Interferometer Space Antenna (LISA) spacecraft. Within the space of all possible interferometric combinations TDI can generate, we have derived a specific combination that has zero response to the gravitational wave signal, and called it the zero-signal solution (ZSS). This is a two-parameter family of linear combinations of the generators of the TDI space, and its response to a gravitational wave becomes null when these two parameters coincide with the values of the angles of …
Rectification Of Thermal Fluctuations In Ideal Gases, Alejandro Garcia, P. Meurs, C. Van De Broeck
Rectification Of Thermal Fluctuations In Ideal Gases, Alejandro Garcia, P. Meurs, C. Van De Broeck
Alejandro Garcia
We calculate the systematic average speed of the adiabatic piston and a thermal Brownian motor, introduced by C. Van den Broeck, R. Kawai and P. Meurs [Phys. Rev. Lett. 93, 090601 (2004)], by an expansion of the Boltzmann equation and compare with the exact numerical solution.
Generation Of The Transient Electrical And Spontaneous Magnetic Fields By Solid State Combustion, Karen S. Martirosyan, J. R. Claycomb, J. H. Miller Jr., D. Luss
Generation Of The Transient Electrical And Spontaneous Magnetic Fields By Solid State Combustion, Karen S. Martirosyan, J. R. Claycomb, J. H. Miller Jr., D. Luss
Physics and Astronomy Faculty Publications and Presentations
Experiments revealed that transient electric field intensities up to 2.5 V/cm were generated during the initial period of combustion synthesis of the ferromagnetic products before the maximum temperature was reached. This occurred when the iron particles were partially oxidized and the reaction product was mainly magnetite sFe3O4d. The electromagnetic field caused spontaneous magnetization of the product in the postcombustion zone. Magnetic field values up to 4 µT formed after the sample temperature fell below the Curie temperature and the initial reactants were completely converted to the ferromagnetic phase PbFe12O19. Increasing the volume of the samples increases the absolute residual magnetic …
Setting Upper Limits On The Strength Of Periodic Gravitational Waves From Psr J1939+2134 Using The First Science Data From The Geo 600 And Ligo Detectors, B. P. Abbott, R. Abbott, Mario C. Diaz, Wm. R. Johnston, Joseph D. Romano, Cristina V. Torres
Setting Upper Limits On The Strength Of Periodic Gravitational Waves From Psr J1939+2134 Using The First Science Data From The Geo 600 And Ligo Detectors, B. P. Abbott, R. Abbott, Mario C. Diaz, Wm. R. Johnston, Joseph D. Romano, Cristina V. Torres
Physics and Astronomy Faculty Publications and Presentations
Data collected by the GEO 600 and LIGO interferometric gravitational wave detectors during their first observational science run were searched for continuous gravitational waves from the pulsar J1939+2134 at twice its rotation frequency. Two independent analysis methods were used and are demonstrated in this paper: a frequency domain method and a time domain method. Both achieve consistent null results, placing new upper limits on the strength of the pulsar’s gravitational wave emission. A model emission mechanism is used to interpret the limits as a constraint on the pulsar’s equatorial ellipticity.
Probing Molecular Free Energy Landscapes By Periodic Loading, Oliver Braun, Andreas Hanke, Udo Seifert
Probing Molecular Free Energy Landscapes By Periodic Loading, Oliver Braun, Andreas Hanke, Udo Seifert
Physics and Astronomy Faculty Publications and Presentations
Single molecule pulling experiments provide information about interactions in biomolecules that cannot be obtained by any other method. However, the reconstruction of the molecule’s free energy profile from the experimental data is still a challenge, in particular, for the unstable barrier regions. We propose a new method for obtaining the full profile by introducing a periodic ramp and using Jarzynski’s relation for obtaining equilibrium quantities from nonequilibrium data. Our simulated experiments show that this method delivers significant more accurate data than previous methods, under the constraint of equal experimental effort.