The 72-H Webt Microvariability Observation Of Blazar S5 0716+714 In 2009,
2013
Florida International University
The 72-H Webt Microvariability Observation Of Blazar S5 0716+714 In 2009, G Bhatta, Stéphane Vennes
Aerospace, Physics, and Space Science Faculty Publications
Context. The international Whole Earth Blazar Telescope (WEBT) consortium planned and carried out three days of intensive micro-variability observations of S5 0716+714 from February 22, 2009 to February 25, 2009. This object was chosen due to its bright apparent magnitude range, its high declination, and its very large duty cycle for micro-variations. Aims. We report here on the long continuous optical micro-variability light curve of 0716+714 obtained during the multi-site observing campaign during which the Blazar showed almost constant variability over a 0.5 mag range. The resulting light curve is presented here for the first time. Observations from participating observatories …
Modeling The X-Ray Light Curves Of Cygnus X-3 Possible Role Of The Jet,
2013
University of Helsinki
Modeling The X-Ray Light Curves Of Cygnus X-3 Possible Role Of The Jet, Osmi Vilhu, Diana Carina Hannikainen
Aerospace, Physics, and Space Science Faculty Publications
Context. We address the physics behind the soft X-ray light curve asymmetries in Cygnus X-3, a well-known microquasar. Aims. Observable eff ects of the jet close to the line-of-sight were investigated and interpreted within the frame of light curve physics. Methods. The path of a hypothetical imprint of the jet, advected by theWolf-Rayet-wind, was computed and its crossing with the line-of-sight during the binary orbit determined. We explored the possibility that physically this “imprint” is a formation of dense clumps triggered by jet bow shocks in the wind (“clumpy trail”). Models for X-ray continuum and emission line light curves were …
Azimuthal Anisotropy Of Π⁰ And Η Mesons In Au + Au Collisions At √Snn=200,
2013
University of Colorado, Boulder
Azimuthal Anisotropy Of Π⁰ And Η Mesons In Au + Au Collisions At √Snn=200, Andrew Marshall Adare, Gyöngyi Baksay, László A. Baksay, Marcus Hohlmann
Aerospace, Physics, and Space Science Faculty Publications
The azimuthal anisotropy coefficients v₂ and v₄ of π⁰ and η mesons are measured in Au + Au collisions at √sNN=200 GeV as a function of transverse momentum pT (1-14 GeV/c) and centrality. The extracted v₂ coefficients are found to be consistent between the two meson species over the measured pT range. The ratio of v₄/v₂² for π⁰ mesons is found to be independent of pT for 1-9 GeV/c, implying a lack of sensitivity of the ratio to the change of underlying physics with pT. Furthermore, the ratio of v₄/v₂² is systematically larger in central collisions, which may reflect the …
Visualizing And Understanding Tectonism And Volcanism On Earth And Other Terrestrial Bodies,
2013
Old Dominion University
Visualizing And Understanding Tectonism And Volcanism On Earth And Other Terrestrial Bodies, Mladen M. Dordevic
Physics Theses & Dissertations
This dissertation presents new methods of visualizing, teaching, assessing, modeling, and understanding tectonics on Earth and other celestial bodies. Tectonics is the study of planetary lithospheres and includes impact, plate, plume, cryo- and gravitational mechanisms. This dissertation is concerned with plate tectonics and plate/mantle plume interactions. Plate tectonics describes the mainly horizontal motion of lithospheric plates over the asthenosphere. Lithosphere is created at ridges and consumed at subduction zones. In addition to the plate tectonic system, mantle plumes also contribute to mass motions in the subsurface Earth. Both plate tectonics and plume upwelling processes help shape the present form of …
Practical Approach To Cosmological Perturbations In Modified Gravity,
2013
SISSA - International School for Advanced Studies
Practical Approach To Cosmological Perturbations In Modified Gravity, Alessandra Silvestri, Levon Pogosian, Roman V. Buniy
Mathematics, Physics, and Computer Science Faculty Articles and Research
The next generation of large scale surveys will not only measure cosmological parameters within the framework of general relativity, but will also allow for precision tests of the framework itself. At the order of linear perturbations, departures from the growth in the standard cosmological model can be quantified in terms of two functions of time and Fourier number k. We argue that in local theories of gravity, in the quasistatic approximation, these functions must be ratios of polynomials in k, with the numerator of one function being equal to the denominator of the other. Moreover, the polynomials are even and …
Unsolved Problems In Special And General Relativity,
2013
University of New Mexico
Unsolved Problems In Special And General Relativity, Florentin Smarandache, Fu Yuhua, Zhao Fengjuan
Branch Mathematics and Statistics Faculty and Staff Publications
This book includes 21 papers written by 23 authors and co-authors. All papers included herein are produced by scholars from People’s Republic of China, except two papers written by Prof. L. Sapogin, V. A. Dzhanibekov, Yu. A. Ryabov from Russia, and by Prof. Florentin Smarandache from USA. The editors hope that all these papers will contribute to the advance of scholarly research on several aspects of Special and General Relativity. This book is suitable for students and scholars interested in studies on physics. The first paper is written by Hua Di. He writes that Einstein’s general theory of relativity cannot …
Fuzzy Analysis Of School Dropouts And Their Life After,
2013
University of New Mexico
Fuzzy Analysis Of School Dropouts And Their Life After, Florentin Smarandache, W.B. Vasantha Kandasamy, K. Amal, K. Kandasamy
Branch Mathematics and Statistics Faculty and Staff Publications
In this book authors study and analyze the problem of school dropouts and their life after. The problems can by no means be analyzed by collecting the numerical data. For such data can only serve as information beyond that the data can be of no use, for the school dropouts suffer an environment change after becoming a school dropout. Thus the emotions of the school dropout; is technically involved. A school dropout can be a child labourer, a rag picker or a social miscreant or be in police custody or be in a rehabilitation home if he/she is a runaway. …
Study Of Dynamic Features Of Highly Energetic Reactions By Dsc And High-Speed Temperature Scanner (Hsts),
2013
The University of Texas Rio Grande Valley
Study Of Dynamic Features Of Highly Energetic Reactions By Dsc And High-Speed Temperature Scanner (Hsts), Mkhitar Hobosyan, Kh. G. Kirakosyan, S. L. Kharatyan, Karen S. Martirosyan
Physics & Astronomy Faculty Publications
The dynamic features of Al2O3 - polytetrafluoroethylene (PTFE) and Al - PTFE reactions in non-isothermal conditions are presented. The Differential Scanning Calorimetry (DSC) and High-Speed Temperature Scanner (HSTS) were used to characterize the Al2O3/Al – PTFE reactions at different heating rates. The study shows that the HSTS instrument can give more information about the reaction mechanism and kinetics than the conventional DSC measurements. In this work we show that high heating rates may reveal exothermic reaction between Al2O3 and PTFE that were previously unidentified. The PTFE can potentially remove the oxide layer from aluminum in the initial period of the …
Search For Long-Lived Gravitational-Wave Transients Coincident With Long Gamma-Ray Bursts,
2013
Texas Southern University
Search For Long-Lived Gravitational-Wave Transients Coincident With Long Gamma-Ray Bursts, J. Aasi, Daniel Bessis, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Malik Rakhmanov, Volker Quetschke, Joseph D. Romano, Robert Stone, Lappoon R. Tang, Cristina V. Torres
Physics & Astronomy Faculty Publications
Long gamma-ray bursts (GRBs) have been linked to extreme core-collapse supernovae from massive stars. Gravitational waves (GW) offer a probe of the physics behind long GRBs. We investigate models of long-lived (~10–1000 s) GW emission associated with the accretion disk of a collapsed star or with its protoneutron star remnant. Using data from LIGO’s fifth science run, and GRB triggers from the Swift experiment, we perform a search for unmodeled long-lived GW transients. Finding no evidence of GW emission, we place 90% confidence-level upper limits on the GW fluence at Earth from long GRBs for three waveforms inspired by a …
Parameter Estimation For Compact Binary Coalescence Signals With The First Generation Gravitational-Wave Detector Network,
2013
The University of Texas Rio Grande Valley
Parameter Estimation For Compact Binary Coalescence Signals With The First Generation Gravitational-Wave Detector Network, J. Aasi, J. Abadie, Matthew Benacquista, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, Robert Stone, Cristina V. Torres
Physics & Astronomy Faculty Publications
Compact binary systems with neutron stars or black holes are one of the most promising sources for ground-based gravitational-wave detectors. Gravitational radiation encodes rich information about source physics; thus parameter estimation and model selection are crucial analysis steps for any detection candidate events. Detailed models of the anticipated waveforms enable inference on several parameters, such as component masses, spins, sky location and distance, that are essential for new astrophysical studies of these sources. However, accurate measurements of these parameters and discrimination of models describing the underlying physics are complicated by artifacts in the data, uncertainties in the waveform models and …
Carbon Monoxide Adsorption On Platinum-Osmium And Platinum-Ruthenium-Osmium Mixed Nanoparticles,
2013
The University of Texas Rio Grande Valley
Carbon Monoxide Adsorption On Platinum-Osmium And Platinum-Ruthenium-Osmium Mixed Nanoparticles, Nicholas Dimakis, Nestor E. Navarro, Eugene S. Smotkin
Physics & Astronomy Faculty Publications
Density functional calculations (DFT) on carbon monoxide (CO) adsorbed on platinum, platinum-osmium, and platinum-ruthenium-osmium nanoclusters are used to elucidate changes on the adsorbate internal bond and the carbon-metal bond, as platinum is alloyed with osmium and ruthenium atoms. The relative strengths of the adsorbate internal bond and the carbon-metal bond upon alloying, which are related to the DFT calculated C–O and C–Pt stretching frequencies, respectively, cannot be explained by the traditional 5σ-donation/2π*-back-donation theoretical model. Using a modified π-attraction σ-repulsion mechanism, we ascribe the strength of the CO adsorbate internal bond to changes in the polarization of the adsorbate-substrate hybrid orbitals …
Galaxy Zoo : A Catalog Of Overlapping Galaxy Pairs For Dust Studies.,
2013
University of Alabama - Tuscaloosa
Galaxy Zoo : A Catalog Of Overlapping Galaxy Pairs For Dust Studies., William C. Keel, Anna M. Manning, Benne W. Holwerda, Massimo Mezzoprete, Chris J. Lintott, Kevin Schawinski, Pamela Gay, Karen L. Masters
Faculty and Staff Scholarship
Analysis of galaxies with overlapping images offers a direct way to probe the distribution of dust extinction and its effects on the background light. We present a catalog of 1990 such galaxy pairs selected from the Sloan Digital Sky Survey (SDSS) by volunteers of the Galaxy Zoo project. We highlight subsamples which are particularly useful for retrieving such properties of the dust distribution as UV extinction, the extent perpendicular to the disk plane, and extinction in the inner parts of disks. The sample spans wide ranges of morphology and surface brightness, opening up the possibility of using this technique to …
Testing Diagnostics Of Nuclear Activity And Star Formation In Galaxies At Z > 1,
2012
University of California - Santa Cruz
Testing Diagnostics Of Nuclear Activity And Star Formation In Galaxies At Z > 1, Jonathan R. Trump, Nicholas P. Konidaris, Guillermo Barro, David C. Koo, Dale D. Kocevski, Stéphanie Juneau, Benjamin J. Weiner, S. M. Faber, Ian S. Mclean, Renbin Yan, Pablo G. Pérez-González, Victor Villar
Physics and Astronomy Faculty Publications
We present some of the first science data with the new Keck/MOSFIRE instrument to test the effectiveness of different AGN/SF diagnostics at z ~ 1.5. MOSFIRE spectra were obtained in three H-band multi-slit masks in the GOODS-S field, resulting in 2 hr exposures of 36 emission-line galaxies. We compare X-ray data with the traditional emission-line ratio diagnostics and the alternative mass-excitation and color-excitation diagrams, combining new MOSFIRE infrared data with previous HST/WFC3 infrared spectra (from the 3D-HST survey) and multiwavelength photometry. We demonstrate that a high [O III]/Hβ ratio is insufficient as an active galactic nucleus (AGN) indicator …
The Central Molecular Gas Structure In Liners With Low-Luminosity Active Galactic Nuclei: Evidence For Gradual Disappearance Of The Torus,
2012
Instituto de Astrofísica de Canarias, Spain
The Central Molecular Gas Structure In Liners With Low-Luminosity Active Galactic Nuclei: Evidence For Gradual Disappearance Of The Torus, F. Müller-Sánchez, M. A. Prieto, M. Mezcua, R. I. Davies, M. A. Malkan, Moshe Elitzur
Physics and Astronomy Faculty Publications
We present observations of the molecular gas in the nuclear environment of three prototypical low-luminosity active galactic nuclei (LLAGNs), based on VLT/SINFONI AO-assisted integral-field spectroscopy of H2 1-0 S(1) emission at angular resolutions of ~0.''17. On scales of 50-150 pc, the spatial distribution and kinematics of the molecular gas are consistent with a rotating thin disk, where the ratio of rotation (V) to dispersion (σ) exceeds unity. However, in the central 50 pc, the observations reveal a geometrically and optically thick structure of molecular gas (V/σ < 1 and N H > 1023 cm–2 …
Kelt-1b: A Strongly Irradiated, Highly Inflated, Short Period, 27 Jupiter-Mass Companion Transiting A Mid-F Star,
2012
Swarthmore College
Kelt-1b: A Strongly Irradiated, Highly Inflated, Short Period, 27 Jupiter-Mass Companion Transiting A Mid-F Star, R. J. Siverd, T. G. Beatty, J. Pepper, J. D. Eastman, K. Collins, A. Bieryla, D. W. Latham, L. A. Buchhave, Eric L.N. Jensen, J. R. Crepp, R. Street, K. G. Stassun, B. S. Gaudi, P. Berlind, M. L. Calkins, D. L. Depoy, G. A. Esquerdo, B. J. Fulton, G. Fürész, J. C. Geary, A. Gould, L. Hebb, J. F. Kielkopf, J. L. Marshall, R. Pogge, K. Z. Stanek, R. P. Stefanik, A. H. Szentgyorgyi, M. Trueblood, P. Trueblood, A. M. Stutz, J. L. Van Saders
Physics & Astronomy Faculty Works
We present the discovery of KELT-1b, the first transiting low-mass companion from the wide-field Kilodegree Extremely Little Telescope-North (KELT-North) transit survey. A joint analysis of the spectroscopic, radial velocity, and photometric data indicates that the V = 10.7 primary is a mildly evolved mid-F star with T-eff = 6516 +/- 49 K, log g = 4.228(-0.021)(+0.014), and [Fe/H] = 0.052 +/- 0.079, with an inferred mass M* = 1.335 +/- 0.063M(circle dot) and radius R* = 1.471(-0.035)(+0.045) R-circle dot. The companion is a low-mass brown dwarf or a super-massive planet with mass M-P = 27.38 +/- 0.93 M-Jup and radius …
Tuning Of Alternative Splicing - Switch From Proto-Oncogene To Tumor Suppressor,
2012
The University of Texas Rio Grande Valley
Tuning Of Alternative Splicing - Switch From Proto-Oncogene To Tumor Suppressor, Aleksandra Shchelkunova, Boris Ermolinsky, Meghan Boyle, Ivan Mendez, Michael Lehker, Karen S. Martirosyan, Alexander V. Kazansky
Physics & Astronomy Faculty Publications
STAT5B, a specific member of the ST AT family, is intimately associated with prostate tumor progression. While the full form of STAT5B is thought to promote tumor progression, a naturally occurring truncated isoform acts as a tumor suppressor. We previously demonstrated that truncated STAT5 is generated by insertion of an alternatively spliced exon and results in the introduction of an early termination codon. Present approaches targeting ST AT proteins based on inhibition of functional domains of STAT's, such as DNA-binding, cooperative binding (protein-protein interaction), dimerization and phosphorylation will halt the action of the entire gene, both the proto-oncogenic and tumor …
Investigation Of Low-Stress Silicon Nitride As A Replacement Material For Beryllium X-Ray Windows,
2012
Brigham Young University - Provo
Investigation Of Low-Stress Silicon Nitride As A Replacement Material For Beryllium X-Ray Windows, David B. Brough
Theses and Dissertations
The material properties of low stress silicon nitride make it a possible replacement material for beryllium in X-ray windows. In this study, X-ray windows made of LPCVD deposited low stress silicon nitride are fabricated and characterized. The Young's modulus of the LPCVD low stress silicon nitride are characterized and found to be 226±23 GPa. The residual stress is characterized using two different methods and is found to be 127±25 MPa and 141±0.28 MPa. Two support structure geometries for the low stress silicon nitride X-ray windows are used. X-ray windows with thicknesses of 100 nm and 200 nm are suspended on …
Thin Films Of Carbon Nanotubes And Nanotube/Polymer Composites,
2012
Brigham Young University - Provo
Thin Films Of Carbon Nanotubes And Nanotube/Polymer Composites, Anthony D. Willey
Theses and Dissertations
A method is described for ultrasonically spraying thin films of carbon nanotubes that have been suspended in organic solvents. Nanotubes were sonicated in N-Methyl-2-pyrrolidone or N-Cyclohexyl-2-pyrrolidone and then sprayed onto a heated substrate using an ultrasonic spray nozzle. The solvent quickly evaporated, leaving a thin film of randomly oriented nanotubes. Film thickness was controlled by the spray time and ranged between 200-500 nm, with RMS roughness of about 40 nm. Also described is a method for creating thin (300 nm) conductive freestanding nanotube/polymer composite films by infiltrating sprayed nanotube films with polyimide.
Comparing Theory And Experiment For Analyte Transport In The First Vacuum Stage Of The Inductively Coupled Plasma Mass Spectrometer,
2012
Brigham Young University - Provo
Comparing Theory And Experiment For Analyte Transport In The First Vacuum Stage Of The Inductively Coupled Plasma Mass Spectrometer, Matthew R. Zachreson
Theses and Dissertations
The Direct Simulation Monte Carlo algorithm as coded in FENIX is used to model the transport of trace ions in the first vacuum stage of the inductively coupled plasma mass spectrometer. Haibin Ma of the Farnsworth group at Brigham Young University measured two radial trace density profiles: one 0.7 mm upstream of the sampling cone and the other 10 mm downstream. We compare simulation results from FENIX with the experimental results. We find that gas dynamic convection and diffusion are unable to account for the experimentally-measured profile changes from upstream to downstream. Including discharge quenching and ambipolar electric fields, however, …
Modeling Radial Bernstein Modes In A Finite-Length Axisymmetric Non-Neutral Plasma,
2012
Brigham Young University - Provo
Modeling Radial Bernstein Modes In A Finite-Length Axisymmetric Non-Neutral Plasma, Mark Andrew Hutchison
Theses and Dissertations
Axisymmetric radial Bernstein modes are known to exist in non-neutral plasmas and have been studied theoretically and computationally in 1D, but detection of these modes has still proven to be difficult due to self-shielding. To help advance the work on this front we created a 2D particle-in-cell (PIC) code that simulates a non-neutral plasma in a Malmberg-Penning trap. A detailed description of the PIC code itself has been included that highlights the benefits of using an $r^2$--$z$ grid and how it can be tested. The focus of the PIC simulation was to discover how best to drive and detect these …
