Bulletin of the American Physical Society
APS April Meeting 2015
Volume 60, Number 4
Saturday–Tuesday, April 11–14, 2015; Baltimore, Maryland
Session L1: Poster Session II (14:00 - 17:00) |
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Sponsoring Units: APS Room: South Foyer |
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L1.00001: ASTROPHYSICS |
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L1.00002: MEST- there is a dark hole around solar system Dayong Cao According to Einstein's equation and a TaiJi model-a balance between the spacetime and massenergy, the paper supposes there is a dark hole around the solar system, and they build up a balance system. The dark hole is made up of dark matter-dark massenergy that is spacetime center, so it is difficult observed. The supposing of dark hole will try to explain below questions: 1. What is dark matter? 2. Why and how do dark matter around galaxies and star? 3. Are there have relationship between dark matter and ``Oort Cloud''? 4. Why are there Jovian planets and terrestrial planets? 5. Why do the Jovian planets of big mass is far away from sun? 6. Why do planets have elliptic orbits and the same direction of their revolution? 7. How did periodicity Mass Extinctions caused by seasonal impaction of dark hole or dark matter? 8. Why did the dark asteroid look like dark comet? Why is asteroid-1950 DA such low density and rock hull of 67P/Churyumov-Gerasimenko? 9. Did the dark matter made coal, oil and natural gas during the Mass Extinctions on our earth? 10. Could consciousness of life help lives to renew and evolve from the Mass Extinctions? http://meeting.aps.org/link/BAPS.2015.APR.T1.26 http://meeting.aps.org/link/BAPS.2015.MAR.Z23.14 http://meetings.aps.org/link/BAPS.2013.MAR.H1.267 http://meetings.aps.org/link/BAPS.2009.APR.E1.33 http://meetings.aps.org/link/BAPS.2010.APR.C1.37 http://meetings.aps.org/link/BAPS.2014.APR.L1.3 http://meetings.aps.org/link/BAPS.2014.APR.L1.2 [Preview Abstract] |
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L1.00003: Ammonia and HC7N Emission in Dense Cores Tierra Candelaria, Scott Schnee, Katie Devine Dense cores represent the transition between the turbulent, diffuse ISM and protostars. Thus, understanding dense cores' chemical and physical properties provides valuable information about the early stages of low mass star formation.~We present an analysis of 13 starless dense cores in the Taurus Molecular Cloud using new data taken with the Green Bank Telescope. Our observations consist of ammonia (NH$_{\mathrm{3}})$ (1,1) and (2,2) and HC$_{\mathrm{7}}$N (J$=$21-20) emission.~ We present new detections of HC$_{\mathrm{7}}$N (a carbon chain bearing species) in four cores and confirm detection in two cores. We also present temperature and velocity gradient maps. These results are the foundation of a more complete survey and illustrate an important relationship between ammonia and the carbon chain bearing species HC$_{\mathrm{7}}$N. [Preview Abstract] |
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L1.00004: Active Galactic Nuclei with Fermi-LAT Jeremy Perkins Since the launch of the Fermi satellite in 2008, the Large Area Telescope (LAT) has detected over 1500 active galactic nuclei (AGNs). The high sensitivity, large field-of-view and broad energy range of the LAT has provided new insights into AGN physics and enabled many discoveries. Highlights from 6 years of gamma-ray observations of AGN with the LAT will be presented. [Preview Abstract] |
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L1.00005: Leptonic cascade around Kerr BHs and the formation of relativistic jets Alex Ford, Brett Keenan, Mikhail Medvedev Relativistic jets from Active Galactic Nuclei (AGN), blazars, quasars and micro-quasars, radio-active galaxies and some other systems host rapidly spinning (Kerr) black holes (BHs). They are powered by Blandford-Znajek mechanism, which converts the BH rotational energy into Poynting flux. This process requires the presence of external magnetic fields brought by accreting gas and highly ionized plasma created {\it in situ}. Thus, plasma production in the so-called ``gap'' region of the BH magnetosphere is crucial for the jets to exist. Here we explored numerically the conditions (the ambient photon field, magnetic field strength, BH spin) needed for the cascade for be efficient, and discuss the properties of the astrophysical systems needed to exhibit powerful jets. [Preview Abstract] |
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L1.00006: A Study of u-Magnitude Dependence in the Spatial Orientation of Spin Vectors of SDSS Galaxies Amit Poudel, Binil Aryal We present a study of spatial orientation of 44\,749 $u$-magnitude SDSS (Sloan Digital Sky Survey) galaxies that have redshift 0.10 to 0.11. The $u$-magnitudes are observed through 355.1 nm CCD (charge coupled device) filter attached to SDSS telescope located at New Mexico, USA. These are the database of mostly Lymen emission lines emitted from distant galaxies. The two-dimensional observed data are converted into three dimensional rotation axes of the galaxy using the method developed by Flin \& Godlowski (1986). Our aim is to study the non-random effect and to check $u$-magnitude dependance in the spatial orientation of galaxies in the large scale structure. The expected isotropy distribution curves are obtained by removing the selection effects and performing a random simulation method as proposed by Aryal \& Saurar (2000). In general, our result supports Hierarchy model as proposed by Peebles (1969). A local anisotropy is observed in few samples suggesting a gravitational tidal interaction between neighbor galaxies, an early-merging process in which the angular momentum vector distort the initial alignment of nearby galaxy. [Preview Abstract] |
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L1.00007: The Dark Energy Survey: Redshifts, X-ray Temperatures and Luminosities for Galaxy CLusters within Science Verification Data Christopher Miller, Philip Rooney, Kathy Romer, Jeeseon Song, Yuanyuan Zhang We present a joint analysis of the Dark Energy Survey (DES) Science Verification data and the {\it XMM} Cluster Survey (XCS). We identify $\sim 200$ galaxy clusters covering a wide range of redshifts ($0.03 \le z \le 1.25$) and temperatures ($1 \le T_{\rm X} \le 11$ keV). The median redshift of the sample is $z \sim 0.4$ and the median temperature is $T_{\rm X} = \sim 3$ keV. A majority are newly discovered clusters. We use a combination of archival and new spectroscopy to calibrate photometric redshifts to 1\% precision and sub-percent accuracy. We examine a number of possible systematic effects which could bias the photometric redshift determinations including deblending in cluster cores, magnitude definitions, and photometric accuracy. We highlight the quality of the Dark Energy Survey data and the promise of large-area joint optical/X-ray galaxy cluster samples. [Preview Abstract] |
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L1.00008: Bright Central Galaxies (BCGs) in Dark Energy Survey Science Verification Data: Stellar Mass Growth in X-Ray Selected Clusters and Groups Since z=1.2 Yuanyuan Zhang, Christopher Miller, Timothy McKay We study the stellar mass of bright central galaxies and its evolution with time. We use a new sample of 106 $0 |
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L1.00009: Dark Energy may be the Graviton as a Quantum Spin Energy and May tell us how Galaxies are formed Richard Kriske If Neutron Stars break up, one has to surmise that there is a particle called the Neutron Crystal Particle (NCP) which gives the Energy of Crystallization of the Neutrons which are compacted to form the Neutron Star. We see this Particle in the Belt of Stability of Nucleons. The ``Belt of Stability'' has the form kx + b, with magic numbers such as 2, 8, 20, 28, etc. As we know from Quantum Mechanics an Harmonic Oscillator has the form kx. The Harmonic is telling us how the Particle is formed by the Graviton pressing Neutrons together is. This Author believes he knows what this particle is and how it is connected to both the Graviton and the Dark Energy. The Graviton has a Quantum Mechanical Component and is only partly revealed the Classical Form. In addition to this form there is a coupling that exists between Nucleons, and that is why the Neutron Star is a Character in this Cosmic Drama. When the Nucleons in the Neutron Star Break apart they are still connected to each other through the NCP which is how they know that they can only be stable if they are in the Belt of Stability. The Belt is the EPR version of the Graviton, and it is the Potential Energy which causes Nucleons to be connected no matter how far apart they are, similar to Pauli Electrons. [Preview Abstract] |
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L1.00010: Fallback Accretion in Core-Collapse Supernova Explosions Hannalore J. Gerling-Dunsmore, Christian D. Ott Core-collapse supernovae (CCSNe) are expected to result in one of two kinds remnants: neutron stars (NSs) and black holes (BHs). It is believed that if a CCSN explosion fails, a BH results, and if the explosion is successful, a NS results. This certainly is the case if there is a strong explosion that unbinds the entire stellar mantle. However, in the case of a weak or severely asymmetric explosion, a substantial quantity of material may fall back. This is commonly called fallback accretion, and it is a potential means of BH formation. We study fallback accretion in spherically-symmetric (1D) neutrino-driven CCSNe using the open-source GR1D code. We obtain explosions by artificially enchancing neutrino energy deposition and in this way also control the explosion energy. We present results on the mapping from progenitor structure and explosion energy to amount and rate of fallback accretion. [Preview Abstract] |
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L1.00011: The Needle in the 100 deg2 Haystack: From Fermi GRBs to LIGO Discoveries with the Palomar Transient Factory Leo Singer The Fermi satellite has greatly expanded the sample and energy window of gamma-ray bursts (GRBs), but the 10-100 deg$^2$ localizations from the onboard Gamma-ray Burst Monitor (GBM) have posed a formidable obstacle to locating their multiwavelength afterglows with narrow-field instruments. Wide-field, time-domain optical surveys are the key. We present the results of one year of target-of-opportunity searches with the intermediate Palomar Transient Factory (iPTF): the first eight afterglow discoveries based solely on Fermi GBM localizations. Two (GRBs 130702A and 140606B) were at low redshift ($z=$0.145 and 0.384 respectively) and had spectroscopically confirmed broad-line type Ic supernovae. Two are possibly consistent with mildly relativistic shocks breaking out from the progenitor stars, rather than the ultra-relativistic internal shock mechanism that powers standard cosmological bursts. Now that such targeted optical searches are becoming routine, we discuss our preparations to search for optical counterparts of binary neutron star mergers that should soon be detected by Advanced LIGO, scheduled to begin science operations in late 2015. We discuss the future of multimessenger observations with subsequent optical surveys, including the Zwicky Transient Facility (ZTF). [Preview Abstract] |
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L1.00012: GCN/TAN: A Status Report Scott Barthelmy The Gamma-ray Coordinates Network / Transient Astronomy Network (GCN/TAN) is your one-stop shopping place for all transient astronomy. It collects nearly all the astrophysical transients from the missions (space-based and ground-based), puts them into a standard format, and distributes them to whomever wishes to receive them. This is all done autonomously (completely autonomous within GCN/TAN, and almost always autonomously within the producer end of operations). This automation means minimal time delays (<0.1 sec within GCN for socket-based distribution methods, and up to 30 sec for email-based which is dependant on the internet email protocol and the number of hops (both of which are out of the control of GCN/TAN). A status report on the current set of sources of transient information, plus recently-added and soon-to-be-added source will be given. Also, a standing request for GCN/TAN to incorporate your transient data stream; plus instruction for customers to receive GCN/TAAN Notice and Circular information. [Preview Abstract] |
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L1.00013: Exotic Particle Production in Gamma Ray Burst Fireballs Ian Morgan, Ted Tao, Erin De Pree, Kevin Tennyson We consider the possible production of stable lightest Kaluza-Klein particles (LKP) in baryonic gamma ray bursts (GRB) out flows. We numerically computed the energy-dependent cross-sections of Kaluza-Klein excitations for the Standard Model gauge bosons, $\gamma$ and $Z$. Next, we determine the feasibility of producing these KK excitations in gamma-ray emitting regions of GRBs. We find that a GRB fireball that accelerates baryons to energies greater than $10^{14}\rm eV$ could produce Kaluza-Klein excitations out to approximately $10^{12} \rm cm$, indicating that GRBs may be a significant source of the LKP. Finally, we explore the potential observational consequences of our results. [Preview Abstract] |
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L1.00014: Investigation of Low Temperature Opacities in Simulations of V838 Monocerotis Stephen Milcarek, James C. Lombardi Jr. We present results of Smoothed Particle Hydrodynamics simulations of merging stars, motivated by the transient V838 Monocerotis. We use different models of the molecule and dust grain mixture present in the outflow of the object, which primarily affects the low temperature opacities and therefore the luminosity, photospheric temperature, and photospheric radius of the merger product. We also present results of simulations investigating the scenarios proposed by Tylenda et al.\ (2005) for the progenitor of V838 Mon. [Preview Abstract] |
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L1.00015: Kelvin-Helmholtz Instabilities in Massive Collapsar Jets Enrique Gomez, April Crawford Collapsars are theoretical class of supernovae, which are the most widely held model for the sources of ``long'' gamma ray bursts (LGRB). They produce LGRB's through anisotropic, beamed jet emission close to the observer's line of sight. These jets must penetrate a radiation-dominated medium of their progenitor and break through its atmosphere in order to produce a LGRB. Recently a new class of ultra long GRB's have been identified with GRB 101225A as its prototype. It is postulated that the progenitors of ULGRBs are likely failed supernovae from massive stars. The issue is whether such jets are hydrodynamically stable as they penetrate the star. We present a study of collapsar jet simulations for this model. Here we invoke the linearized, relativistic fluid equations to find the Kelvin-Helmholtz modes that are triggered by recollimation shocks within the jet. These will then grow as they propagate with the jet. Perturbations that couple to the jet body modes, with a spread of bulk Lorentz factors, may evolve into internal shocks, which may give rise to the light-curve structure of ULGRB's. [Preview Abstract] |
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L1.00016: Relation of the energy and pitch-angle diffusion of charged particles to the emitted radiation in small-scale astrophysical turbulence Brett Keenan, Alex Ford, Mikhail Medvedev Plasma turbulence in some energetic astrophysical objects, such as weakly magnetized collisionless shocks in GRBs and SN, has intense fluctuations at very small small scales. We investigate the relation of the characteristics of radiation produced by charged particles (relativistic through non-relativistic) moving in such turbulence and relate it to the diffusion of these particles in the velocity/energy space. We demonstrate that in contrast to the case of homogeneous B-field, radiation in the sub-Larmor-scale and rapidly fluctuating turbulence reflects statistical and temporal properties of the underlying electromagnetic fields. Both analytical estimates and the results of {\it ab initio} numerical simulations will be presented. We also confirm that particle propagation in such turbulence is diffusive. We evaluate the diffusion coefficients in the velocity space and demonstrate strong coupling of transport and radiation properties, which can be very valuable for remote diagnostics of astrophysical plasmas. [Preview Abstract] |
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L1.00017: Time Evolution of Pulsar Magnetosphere -- An Implicit Approach Sushilkumar Sreekumar, Eric Schlegel The Magnetosphere for a pulsar plays a very significant role in its evolution and is regarded as an ideal site for high energy emission. Understanding the structure, dynamics and evolution of the magnetosphere is important. Contopoulos et al. (CKF, 1999) were able to demonstrate numerically the importance of current sheets (CS) along with the Goldreich-Julian charge density (1969). In addition, Spitkovsky (2006) was also able to numerically solve the time dependent hyperbolic system of equations and validate the existence of CS within the Alfv\'{e}n radius and beyond. However the \textit{explicit }nature of the numerical approach restricts the size of the time step, which results in an unresolved current sheet. Currently the CKF type magnetosphere is the new benchmark in pulsar modelling and hence CS and its distribution plays a key role. Its contribution in pulsar spin down mechanism, high energy emissions, flux outflow, reconnection events, acceleration mechanisms and locations is currently not understood and as a result resolution of the CS is critical. It is with this motivation that our group has decided to develop a computationally challenging \textit{implicit} code under the \textit{force-free electrodynamics}. With \textit{implicit} approach the Courant number can be sufficiently large which will not only help to resolve the CS and spatial resolution but will also guide us within the high conductivity limit of resistive solutions, where the traditional \textit{explicit} method becomes too expensive. [Preview Abstract] |
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L1.00018: Observations of VHE from the Crab Pulsar with VERITAS Avery Archer The Crab pulsar has been closely studied across the electromagnetic spectrum from radio to TeV energies. Observations in recent years have challenged the favored models for the highest-energy emission. With 107 hours of observation, VERITAS first observed the Crab pulsar above 120 GeV, well above the expected cut-off of a few GeV. Pulsar modeling demonstrates that magnetosphere of the Crab is opaque to VHE photons, narrowing the possible emission regions within the magnetosphere given recent observations. As of fall 2014, the exposure has been increased to over 200 hours. These new VERITAS results help to further constrain the models, providing improved information about the origin of very high energy emission within the pulsar magnetosphere. Presented here are results of ongoing observations and analysis of the Crab pulsar from 100 GeV up to TeV energies with the VERITAS telescopes in the context of modeling viable emission region models. [Preview Abstract] |
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L1.00019: Spin Crystals may be commonly formed from Neutron Stars Richard Kriske Neutron Stars may be a Crystal of Neutrons. One has to consider what would happen to this matter if Neutron Stars do not commonly collapse into Black Holes, but rather tear apart. One idea is that the Neutrons would separate and become single Neutrons, or lose an Electron and become Hydrogen with one or more Neutrons or Heavy and Super Heavy water. Perhaps the Graviton plays a role in crushing and packing the matter together, and there is another particle that keeps track of the Crystal structure of the packed Neutrons. We could call this particle the Neutron Crystal Particle. We may know something about it already, in that the Nuclei as we know them have what are know as Magic Numbers of stability. Are there other series that occur but are very rare here? Magic Number series that occur around Black Holes and perhaps in Comets or other bodies that seem to be made of water. When the Neutrons from Neutron Stars break up perhaps they form Spin Crystals, which are like Crystals but are not localized, they fly off in all directions, but are connected through the NCP. One way to test this would be to irradiate a Comet with an X-ray laser since this sort of Crystal could be forced to Fission. Perhaps Comet tails are the result of a Nuclear Reaction with the Sun. [Preview Abstract] |
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L1.00020: New identifications of extended GeV gamma rays from Supernova Remnants with Fermi-LAT Pass 8 data John Hewitt, Micaela Caragiulo, Benjamin Condon, Francesco Giordano, Marianne Lemoine-Goumard Identifying gamma-ray emission from supernova remnants is crucial to test the paradigm for the origin of Galactic cosmic rays. Despite the excellent sensitivity and spatial resolution of the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope, it remains difficult to clearly identify cosmic ray sources buried within the diffuse Galactic background and possibly confused with other gamma-ray sources, such as pulsars. The LAT collaboration has developed a new Pass 8 event reconstruction with improved spatial resolution and acceptance that permits the first detection of extended emission in GeV gamma rays from several supernova remnants. These include the young TeV shell-type remnant RCW 86, and older supernova remnants that are interacting with molecular clouds, such as CTB 37A. The improvements with Pass 8 promise to rapidly grow the population of gamma-ray supernova remnants identified through their spatial extension. [Preview Abstract] |
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L1.00021: Densities of Galactic Center Clouds Jonathan Barnes, Elisabeth A.C. Mills, Mark R. Morris The central 300 parsecs of the Galaxy is full of giant molecular clouds containing 107 solar masses worth of gas. However, our Galactic center is not forming as many stars as we think it can, based on the amount of molecular gas in this region. By studying the densities of the Galactic center clouds we hope to better understand why there is not much star formation occurring. Using data from the Green Bank and MOPRA telescopes we have observed multiple rotation transitions of HC3N and its 13C isotopologues. By measuring the integrated intensity of the HC3N we are able to calculate the densities of these giant molecular clouds. The measured intensities are used with a radiative transfer code called RADEX, to determine volume densities. Our initial results suggest that there may be either less dense or cooler gas in these clouds that previously thought. If there is a significant quantity of gas less dense than 104 molecules/cm3, this could explain the lack of ongoing star formation in these clouds, and might also suggest a shorter timescale for dynamical disruption of theses clouds. In the future, we plan to improve these results by observing additional HC3N transitions, allowing us better to constrain the relative contributions of multiple temperature and density components in Galactic center clouds. [Preview Abstract] |
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L1.00022: Increase of Ionizing Radiation at the Pfotzer Maximum Enrique Gomez, Michele Carmichael-Coker Verso l'alto is a multi-disciplinary research and development project whose goal is to gain insight into the cosmic ray profile of the atmosphere and geolocation of terrestrial gamma-ray flashes (TGFs) over North Carolina, USA. This experiment is comprised of high-altitude weather balloons carrying radiation, pressure and temperature detectors. Eight successful balloon flights have been completed from October 2012-June 2014. Live tracking and telemetry of the flight is performed by an amateur radio communications payload, and beacon coordinates are uploaded to \texttt{aprs.fi} for real-time access online. We conclude that fluctuation peaks within the tropopause are due to the Pfotzer Maximum. Other statistically significant peaks within the time scale of minutes are observed. All data sets confirm peak counts within the Pfotzer Maximum, ranging from altitudes 13.4-22 km (44,146-72,441 feet). [Preview Abstract] |
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L1.00023: Estimating the Number of Cosmic Ray Air Showers a Long Duration EUSO-Balloon Flight would Record Jeremy Fenn, Lawrence Wiencke EUSO-Balloon is a prototype detector for the Extreme Universe Space Observatory (EUSO) planned for the Japanese Experiment Module (JEM) on the International Space Station (ISS). The EUSO-Balloon's initial flight in Timmons, Ontario (August 2014) lasted approximately four hours at float altitude. Since this was too short to detect cosmic rays a calibrated UV laser was fired across the field of view to simulate the extensive air showers caused by cosmic rays. The next logical step is a long duration EUSO-Balloon flight with the instrument optimized to record extensive air showers. In this presentation I will discuss the planned detector specifications and present the simulation methods used to estimate the expected detection rate of cosmic ray air showers by the EUSO-Balloon. [Preview Abstract] |
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L1.00024: Investigation of the Effect of Temperature and Light Emission from Silicon Photomultiplier Detectors Daniel Ruiz Castruita, Daniel Ramos, Victor Hernandez, Rommel Niduaza, Adrian Konx, Sewan Fan, Laura Fatuzzo, Stefan Ritt The silicon photomultiplier (SiPM) is an extremely sensitive light detector capable of measuring very dim light and operates as a photon-number resolving detector. Its high gain comes from operating at slightly above the breakdown voltage, which is also accompanied by a high dark count rate. At this conference poster session we describe our investigation of using SiPMs, the multipixel photon counters (MPPC) from Hamamatsu, as readout detectors for development in a cosmic ray scintillating detector array. Our research includes implementation of a novel design that automatically adjusts for the bias voltage to the MPPC detectors to compensate for changes in the ambient temperature. Furthermore, we describe our investigations for the MPPC detector characteristics at different bias voltages, temperatures and light emission properties. To measure the faint light emitted from the MPPC we use a photomultiplier tube capable of detecting single photons. Our data acquisition setup consists of a 5 Giga sample/second waveform digitizer, the DRS4, triggered to capture the MPPC detector waveforms. Analysis of the digitized waveforms, using the CERN package PAW, would be discussed and presented. [Preview Abstract] |
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L1.00025: Detectability of cosmic dark flow in the type Ia supernova redshift-distance relation Grant Mathews, Benjamin Rose, Peter Garnavich, Toshitaka Kajino, Dai Yamazaki We re-analyze the possibility of large scale dark (bulk) flow with respect the the CMB background based upon the redshift-distance relation for Type Ia Supernovae (SN Ia). We have made a Markov chain Monte Carlo analysis using both the Union.2.1 and SDSS-II data sets. We also utilized simulated data with a bulk flow is imposed to determine whether the difficulty in detecting a bulk flow at high redshift is due to uncertainty in the redshift-distance relation, confusion with peculiar velocities, or the absence of a bulk flow. We find a bulk flow velocity of $v_{\mathrm{bf}} = 270 \pm 50$ km s$^{-1}$ in the direction of galactic coordinates, $(l,b) = (295 \pm 30, 10 \pm 5)^{\circ}$, consistent with previous analyses. While in the redshift bin $z > 0.05$ we find only marginal evidence for a bulk flow velocity of $v_{\mathrm{bf}} = 1000 \pm 600$ km s$^{-1}$ in the direction of galactic coordinates $(l,b) = (120 \pm 80, -5 \pm 30)^{\circ}$. However, we find that the SDSS-II supernova data set has insufficient sky coverage to provide a meaningful result. Based upon simulated data, the uncertainty at high redshifts arises mostly from large distance errors, however, detection might be possible with the next generation of large surveys like LSST. [Preview Abstract] |
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L1.00026: Quantum Vacuum Instability of ``Eternal'' de Sitter Space Emil Mottola The Euclidean or Bunch-Davies state of quantum fields in global de Sitter space is shown to be unstable to small perturbations, even for a massive free field with no self-interactions. There are perturbations of this state with arbitrarily small energy density at early times that is exponentially blueshifted in the contracting phase of ``eternal'' de Sitter space, and becomes large enough to disturb the classical geometry through the semiclassical Einstein eqs. at later times. In the closely analogous case of a constant, uniform electric field, a time symmetric state equivalent to the de Sitter invariant one is constructed, which is also not a stable vacuum state under perturbations. The role of a quantum anomaly in the growth of perturbations and symmetry breaking is emphasized in both cases. The anomaly stress tensor shows that states invariant under the $O(4)$ subgroup of the de Sitter group are also unstable to perturbations of lower spatial symmetry, implying that both the $O(4)$ subgroup are broken by quantum fluctuations. Consequences of this result for cosmology and the problem of vacuum energy will be discussed. [Preview Abstract] |
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L1.00027: Four different animated sub-particles as the origins of the life and creator of different angular momentums of elementary particles Hassan Gholibeigian, Zeinab Gholibeigian Understanding the internal structure of the proton is crucial challenge for QCD, and one important aspect of this is to understand how the spin of the nucleon is build-up from the angular momentum of its quarks and gluons. In this way, what's the origin of differences between angular momentums of fundamental particles? It may be from their substructures. It seems there are four sub-particles of mater, plant, animal and human in substructure of each fundamental particle (string) as the origins of life and cause of differences between spins of those elementary particles. Material's sub-particle always is on and active. When the environmental conditions became ready for creation of each field of the plant, animal and human, sub-particles of their elementary particles became on and active and then, those elementary particles participated in processes of creation in their own field. God, as the main source of information, has been communicated with their sub-particles and transfers a package (bit) of information and laws (plus standard ethics for human sub-particles) to each of them for process and selection (mutation) of the next step of motion and interaction of their fundamental particles with each other in each Plank's time. This is causality for particles' motion in quantum area. [Preview Abstract] |
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L1.00028: Measurement of TeV-scale gamma-ray flux from M31 using data from HAWC-100 Isabella Brewer, Andrew Smith The High Altitude Water Cherenkov observatory (HAWC) is an air-shower array designed for detection of TeV-scale gamma rays. HAWC is located adjacent to the Sierra Negra volcano in Mexico, at an altitude of 4,100 meters. Andromeda Galaxy, M31, is a large nearby spiral galaxy and is a favorable candidate for dark matter detection by HAWC, but is also known to be a source of gamma-rays from cosmic accelerators. M31 has been detected by Fermi at the GeV scale with a flux consistent with that expected from a purely astrophysical origin. Many theories of dark matter predict gamma-ray emission up to the mass of the dark matter particle. For TeV-scale dark matter particles, HAWC may be well suited to indirectly detect a signal from M31 as the gamma-ray flux from astrophysical accelerators falls like a power-law with energy. The potential for detection of both diffuse emission and dark matter make M31 an interesting target. We will present the measurement of the TeV gamma-ray flux from M31 using data from the HAWC-100 detector. [Preview Abstract] |
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L1.00029: Characterization of the Omicron Trigger Generator and Transient Analysis of aLIGO Data Hunter Gabbard Omicron is a burst-type trigger generator. We performed coincidence tests between Omicron generated triggers of ER5 LIGO data and various types of injection wave forms (Sine-Gaussian, White-Noise-Burst, and String Cusp) using a Coincidence Finder program that we developed. Through these tests we determined the efficiency at which the Omicron trigger generator is able to detect specific transient events with varying sets of parameters. We tested and debugged a new version of Omicron and utilized Omicron to perform a close analysis of lock time data at the gravitational wave detector in Livingston, Louisiana. From this analysis we were able to classify noise events and determine several of their sources. [Preview Abstract] |
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L1.00030: Optical frequency standards for gravitational wave detection using satellite velocimetry Amar Vutha Satellite Doppler velocimetry, building on the work of Kaufmann [1] and Estabrook and Wahlquist [2], is a complementary technique to interferometric methods of gravitational wave detection [3]. This method is based on the fact that the gravitational wave amplitude appears in the apparent Doppler shift of photons propagating from an emitter to a receiver. This apparent Doppler shift can be resolved provided that a frequency standard, capable of quickly averaging down to a high stability, is available. We present a design for a space-capable optical atomic frequency standard, and analyze the sensitivity of satellite Doppler velocimetry for gravitational wave astronomy in the milli-hertz frequency band.\\[4pt] [1] Kaufmann, W. (1970). Redshift Fluctuations Arising from Gravitational Waves. Nature, 227, 157.\\[0pt] [2] Estabrook, F., \& Wahlquist, H. (1975). Response of Doppler spacecraft tracking to gravitational radiation. General Relativity and Gravitation, 5(5), 439-447.\\[0pt] [3] Armstrong, J. (2006). Low-frequency gravitational wave searches using spacecraft Doppler tracking. Living Rev. Relativity, (2006). [Preview Abstract] |
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L1.00031: A cross-correlation search for intermediate-duration gravitational waves from GRB magnetars Robert Coyne Since the discovery of the afterglow in 1997, the progress made in our understanding of gamma-ray bursts (GRBs) has been spectacular. Yet a direct proof of GRB progenitors is still missing. In the last few years, evidence for a long-lived and sustained central engine in GRBs has mounted. This has called attention to the so-called millisecond-magnetar model, which proposes that a highly magnetized, rapidly-rotating neutron star may exist at the heart of some of these events. The advent of advanced gravitational wave detectors such as LIGO and Virgo may enable us to probe directly, for the first time, the nature of GRB progenitors and their byproducts. In this context, we describe a novel application of a generalized cross-correlation technique optimized for the detection of long-duration gravitational wave signals that may be associated with bar-like deformations of GRB magnetars. The detection of these signals would allow us to answer some of the most intriguing questions on the nature of GRB progenitors, and serve as a starting point for a new class of intermediate-duration gravitational wave searches. [Preview Abstract] |
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L1.00032: Commissioning subsystems of the 10 meter prototype Nathan Prins, Tobin Fricke, Conor Mow-Lowry, Manuela Hanke The best attempts at detecting the elusive gravitational waves are with L-shaped interferometers. Over the summer of 2014, I helped install subsystems of the 10 meter prototype, a gravitational wave interferometer designed to reach the Standard Quantum Limit (SQL), at the Max Planck Institute for Gravitational Physics in Hannover, Germany through the University of Florida's International REU. While there, the frequency reference cavity was aligned and the mode matching the cavity began. We also worked on installing and testing the intensity stabilization servo, which consisted of an out-of-vacuum photodiode for each the in-loop and out-of-loop sensing that were being connected to the LIGO Control and Data System. [Preview Abstract] |
(Author Not Attending)
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L1.00033: Predicting Binary Black Hole Collisions Using Numerical Methods in Collaboration with LIGO Nousha Afshari, Geoffrey Lovelace Detecting astronomical gravitational waves will soon open a new window on the universe. The effects of gravitational waves have already been seen indirectly, but a direct observation of these waves will test Einstein's theory of general relativity under the most extreme conditions. The Laser Interferometer Gravitational-Wave Observatory, or LIGO, will soon begin searching for gravitational waves, and the first direct detections are likely in the next few years. To help LIGO detect as many gravitational waves as possible, a major research effort is underway to accurately predict the expected waves. In this presentation, I will discuss new supercomputer simulations of merging black holes---some of the brightest sources of gravitational waves---that I have completed using the Spectral Einstein Code (http://www.black-holes.org/SpEC.html). [Preview Abstract] |
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L1.00034: Structural and compositional characterization of carbonaceous meteorites for clues to planet formation Anal\'Ia Dall'As\'en, Sophia Dimas, Sean Vetsch, Jordan Gerton, Benjamin Bromley, Scott Kenyon In modern planet formation theory, the process of coagulation (solids glomming together to create larger bodies from micron-size grains) is responsible for most observed planets. Simulations of rocky, gaseous and icy planet formation strengthen this understanding showing how a sea of planetesimals (the precursors to planets) of 1-100 km in radius can grow into planets. However, the origin of these objects is still unknown, and hence a complete theory of planet formation remains elusive. To understand how planetesimals formed, we study carbonaceous chondritic meteorites, considered the most primitive surviving materials from the early Solar System. These meteorites are mainly composed of chondrules (micro/millimeter-sized inclusions) surrounding by a matrix of microparticles. Here we present a study of how the structure and composition vary in different regions of the chondrules/matrix of various carbonaceous meteorites by mapping the results obtained using high-resolution micro-Raman spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. Thus, we can capture details on small and large spatial scales. Finally we discuss possible interpretations of our results in terms of the astrophysical context in which the meteorites formed. [Preview Abstract] |
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L1.00035: Current Flowing In Accretion Disk and State Transition of Black Hole Binaries Ding-Xiong Wang The state transition of black hole binaries is discussed based on the evolution of magnetic field configuration, and the latter is related closely to the current flowing in an accretion disk around a black hole. It turns out that the main characteristics of the transition from low/hard state to high/soft state can be fitted by invoking the transportation of current from the outer region to the inner region in accretion process. [Preview Abstract] |
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L1.00036: Radiative ablation with two ionizing-fronts when opacity displays a sharp absorption edge Olivier Poujade, Max Bonnefille, Marc Vandenboomgaerde The interaction of a strong flux of photons with matter through an ionizing-front (I-front) is an ubiquitous phenomenon in the context of astrophysics (and inertial confinement fusion) where intense sources of radiation put matter into motion. When the opacity of the irradiated material varies continuously in the radiation spectral domain, only one single I-front is formed. In contrast, as numerical simulations tend to show, when the opacity of the irradiated material presents a sharp edge (around an electronic binding energy of the material) in the radiation spectral domain, a second I-front (an edge-front) can form. A full description of the mechanism behind the formation of this edge-front will be presented. This double ionizing front might have consequences in various domains of astrophysics where ablatively-driven flows play a significant role, such as star formation, acceleration of interstellar clouds, formation of Stromgren sphere in gaseous nebulae and supernovae remnant. [Preview Abstract] |
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L1.00037: Models for Examining Impact of Cosmic Rays on Integrated Circuits William Atkinson The Soft Error Rate (SER) produced by SEUs in microelectronic devices in near-earth orbits and in the atmosphere has been computed using a common model developed at Boeing, TSAREME. In space, TSAREME models protons, alphas, and heavy ions with atomic numbers up to 26 (iron) for GCR and peak solar flares. In the atmosphere, TSAREME computes the neutron flux fluxes produced by charged particles interacting with air molecules, accounting for magnetosphere variations with latitude. The devices include Complementary Metal on Oxide (CMOS) and Silicon on Insulator (SOI) transistors with feature sizes varying from a micron to 15 nm. Validation of model results to empirical data discussed. [Preview Abstract] |
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L1.00038: A new blackhole theorem and its applications to cosmology and astrophysics Shouhong Wang, Tian Ma We shall present a blackhole theorem and a theorem on the structure of our Universe, proved in a recently published paper, based on 1) the Einstein general theory of relativity, and 2) the cosmological principle that the universe is homogeneous and isotropic. These two theorems are rigorously proved using astrophysical dynamical models coupling fluid dynamics and general relativity based on a symmetry-breaking principle. With the new blackhole theorem, we further demonstrate that both supernovae explosion and AGN jets, as well as many astronomical phenomena including e.g. the recent reported are due to combined relativistic, magnetic and thermal effects. The radial temperature gradient causes vertical Benard type convection cells, and the relativistic viscous force (via electromagnetic, the weak and the strong interactions) gives rise to a huge explosive radial force near the Schwarzschild radius, leading e.g. to supernovae explosion and AGN jets. [Preview Abstract] |
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L1.00039: Possibility of vibrationally resolved cross section measurements for low energy charge transfer in H $+$ H$_{2}^{+}$ C.I. Guillen, R.A. Strom, J.A. Tobar, D.I. Panchenko, V.M. Andrianarijaona Charge transfer (CT) in H $+$ H$_{2}^{+}\to $ H$^{+} +$ H$_{2}$ has fundamental implications because it involves the smallest atomic ion, atom, molecular ion, and molecule possible. The current merged-beam apparatus at Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee, can reliably create and access low collision energies; the existing ion-atom merged beams apparatus there is currently able to benchmark the CT of these fundamental systems at energies below 0.1eV/u (Phys. Rev. A \textbf{84}, 062716, 2011). A strong contribution from v$_{i}=$2 is observed, however, the data analysis still suffers from the lack of information on the vibrational state distribution of H$_{2}^{+}$. We are exploring the possibility of inserting a three-dimensional imaging technique at the end station~of the ORNL apparatus in order to measure the vibrational state distribution of H$_{2}^{+}$ that are produced by the electron cyclotron resonance (ECR) ion source. Discussion of our initial design for the insertion of this technique in the aforementioned system will be presented here. [Preview Abstract] |
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L1.00040: 0. MATHEMATICAL-Universe-Hypothesis(MUH) BECOME SCENARIO(MUS)!!! (NOT YET A THEORY) VIA 10-DIGITS[0$\to $9] SEPHIROT CREATION AUTOMATICALLY from DIGITS AVERAGED-PROBABILITY Newcomb-Benford LOG-Law; UTTER-SIMPLICITY!!!: It's a Jack-in-the-Box Universe: Accidental?/Purposeful?; EMET/TRUTH!!! Edward Carl-Ludwig Siegel Siegel(2012) 10-DIGITS[0$\to $9] AVERAGE PROBABILITY LOG-Law SCALE-INVARIANCE UTTER-SIMPLICITY: Kabbala SEPHIROT SCENARIO AUTOMATICALLY CREATES a UNIVERSE: (1) a big-bang[bosons(BEQS) created from Newcomb[Am.J.Math.4(1),39(1881;THE discovery of the QUANTUM!!!)-Poincare[Calcul des Probabilites,313(12)]-Weyl[Goett.Nach.(14);Math.Ann.77,313(16)] DIGITS AVERAGE STATISTICS LOG-Law[\textless P(d)\textgreater $=$log(1$+$1/d)$=$log([d$+$1]/d)] algebraic-inversion, (2)[initial (at first space-time point created) c$=\infty $ elongating to timelike-pencil spreading into finite-c light-cone] hidden-dark-energy (HDE)[forming at every-spacetime-point], (3) inflation[logarithm algebraic-inversion-to exponential], (4) hidden[in Siegel(87) ``COMPLEX quantum-statistics in (Nottale-Linde)FRACTAL-dimensions'' expansion around unit-circle/roots-of-unity]-dark-matter(HDM), (4)null massless bosons(E)$\to $Mellin-(light-speed squared)-transform/Englert-Higgs ``mechanism''$\to $(timelike) massive fermions(m), (5) cosmic-microwave-background (CMB)[power-spectrum] Zipf-law HYPERBOLICITY, (6) supersymmetry(SUSY) [projective-geometry conic-sections/conics merging in ${\rm R}$/${\rm C}$ projective-plane point at $\infty $]. UTTER-SIMPLICITY!!! [Preview Abstract] |
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L1.00041: Locating Gravitational Waves with BayesWave Belinda Cheeseboro LIGO is the Laser Interferometer Gravitational Wave Observatory. Its mission is to detect gravitational waves that could be caused by the interaction of massive gravitating bodies such as coalescing black holes, in-spiraling neutron stars, etc. BayesWave is an algorithm that can analyze possible gravitational wave event data and determine the properties of candidate events such as sky location. This algorithm uses a combination of Bayesian probability theory and the Reverse Jump Markov Chain Monte Carlo (RJMcMC) method to accomplish this goal. BayesWave is able to simultaneously model the gravitational wave signal and the noise by using multi-component models. It uses the RJMcMC to simultaneously perform model selection and fully sample the posterior, to estimate model parameters. This study applies BayesWave to mock events in order to measure its efficacy and compare it with other parameter estimation methods. [Preview Abstract] |
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L1.00042: HISTORY OF PHYSICS |
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L1.00043: The gravitational analog of Faraday's induction law Daniel Zile, James Overduin Michael Faraday, the discoverer of electromagnetic induction, was convinced that there must also be a gravitational analog of this law, and he carried out drop-tower experiments in 1849 to look for the electric current induced in a coil by changes in gravitational flux through the coil. This work, now little remembered, was in some ways the first investigation of what we would now call a unified-field theory. We revisit Faraday's experiments in the light of current knowledge and ask what might be learned if they were to be performed today. We then review the gravitational analog for Faraday's law that arises within the vector (or gravito-electromagnetic) approximation to Einstein's theory of general relativity in the weak-field, low-velocity limit. This law relates spinning masses and induced ``mass currents'' rather than spinning charges and electric currents, but is otherwise remarkably similar to its electromagnetic counterpart. The predicted effects are completely unobservable in everyday settings like those envisioned by Faraday, but are thought to be relevant in astrophysical contexts like the accretion disks around collapsed stars, thus bearing out Faraday's remarkable intuition. [Preview Abstract] |
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L1.00044: Neutrino Mass Measurement Using a Directed Mono-Energetic Beam Vladimir Tsifrinovich, Lorcan Folan It was shown [1] that a directed mono-energetic neutrino beam can be generated by electron capture beta-decay in a sample with a strong hyperfine field at the radioactive nuclei. We study the conditions required to measure the neutrino rest mass using the recoil force produced by a directed neutrino beam. We consider the displacement of an atomic force microscope cantilever due to such a recoil force. We find the change in the cantilever displacement associated with the non-zero neutrino mass, as a function of nuclear half-life $T_{1/2}$, cantilever spring constant, and temperature. We consider the opportunity to increase the sensitivity of the neutrino mass measurement using averaging of the measurement signal. We show that the optimal time for the signal accumulation is, approximately, 1.8$T_{1/2}$. We compute the optimal signal-to-noise ratio for $^{119}Sb$ nuclei decaying to $^{119}Sn$ with a decrease in the nuclear spin from $I$ = 5/2 to $I$ = 3/2, and $T_{1/2}$ = 38.2 hours. Finally, we present the parameters values required for detection of sub-eV neutrino rest mass, and estimate the angular distribution of neutrino radiation as a function of temperature. \\[4pt] [1] C. DeAngelis et al., Phys. Rev. C86, 034615 (2012). [Preview Abstract] |
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L1.00045: COMPUTATIONAL PHYSICS |
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L1.00046: A Study into the Impact of Physical Structures on the Runway Velocity Field at the Atlantic City International Airport David King Jr., Russell Manson, Joseph Trout, Nicholas DeCicco, Manny Rios Wake vortices are generated by airplanes in flight. These vortices decay slowly and may persist for several minutes after their creation. These vortices and associated smaller scale turbulent structures present a hazard to incoming flights. It is for this reason that incoming flights are timed to arrive after these vortices have dissipated. Local weather conditions, mainly prevailing winds, can affect the transport and evolution of these vortices; therefore, there is a need to fully understand localized wind patterns at the airport-sized mircoscale. Here we have undertaken a computational investigation into the impacts of localized wind flows and physical structures on the velocity field at Atlantic City International Airport. The simulations are undertaken in OpenFOAM, an open source computational fluid dynamics software package, using an optimized geometric mesh of the airport. Initial conditions for the simulations are based on historical data with the option to run simulations based on projected weather conditions imported from the Weather Research \& Forcasting (WRF) Model. Sub-grid scale turbulence is modeled using a Large Eddy Simulation (LES) approach. The initial results gathered from the WRF Model simulations and historical weather data analysis are presented elsewhere. [Preview Abstract] |
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L1.00047: Frequency Domain Sampling Using Biomedical Imaging Physics Gun Ha Seo, Minji Chung, Richard Kyung In magnetic resonance image analysis using physical and computational method, the process of transformation from frequency domain to image domain requires significant amount time because Inverse Fourier Transformation (IFT) takes every frequency points to determine the final output image. This paper shows the mechanisms and~physics of image formation~using~the selectivity of proper k-space by removing different amounts of high or low frequencies to create the most optimal magnetic resonance image of a human tibial bone. Originally, square unit step function, N/2-N/10:N/2$+$N/10$=$1, was used during the Fourier Transformations. And Gaussian filter, y$=$ exp(-t$^{\mathrm{2}}$/40$^{\mathrm{n}})$, where t$=$h-L/2, h$=$[0,M], L$=$2*7*N/40, the size of frequency matrix (M, N) $=$ (365,557) was tested. Also circle equations as a filter, r $=$ sqrt((x-M/2)$^{\mathrm{2}}+$(y-N/2)$^{\mathrm{2}})$, were tested in creating the images of the human tibial bone to find an efficient filter. The best efficiency occurred when the exponent n in the proposed Gaussian filter equation is in between 3 and 8, and therefore, a new algorithm is needed to find the exact number since the number is not only an integer. [Preview Abstract] |
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L1.00048: A level set method for solid-liquid interface tracking in texturally equilibrated pore networks Soheil Ghanbarzadeh, Marc Hesse, Masa Prodanovic The properties of some porous media are determined by their evolution towards textural equilibrium. Melt drainage from temperate glacier ice and the accumulation of hydrocarbons beneath rock salt are two examples in natural systems. In these materials, pore geometry evolves to minimize the solid-liquid interfacial energy while maintaining dihedral angle, $\theta $, at solid-liquid contact lines. In this work we present the first computations of 3-D texturally equilibrated pore networks using a novel level set method. Interfacial energy minimization is achieved by evolving interface under surface diffusion to constant mean curvature surface. The porosity and dihedral angle constraints are added to the formulation using virtual velocity terms. A domain decomposition scheme is devised to restrict the computational domain and the coupling between the interfaces is achieved on the original computational domain. For the last 30 years, explicit representation of the interfaces limited the computations to highly idealized geometries. The presented model overcomes these limitations and opens the door to the exploration of the physics of these materials in realistic systems. For example, our results show that the fully wetted grain boundaries exist even for $\theta $\textgreater 0 which reconciles the theory with experimental observations. [Preview Abstract] |
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L1.00049: Investigating Anomalies in the Output Generated by the Weather Research and Forecasting (WRF) Model Nicholas DeCicco, Joseph Trout, J. Russell Manson, Manny Rios, David King The Weather Research and Forecasting (WRF) model is an advanced mesoscale numerical weather prediction (NWP) model comprised of two numerical cores, the Numerical Mesoscale Modeling (NMM) core, and the Advanced Research WRF (ARW) core. An investigation was done to determine the source of erroneous output generated by the NMM core. In particular were the appearance of zero values at regularly spaced grid cells in output fields and the NMM core's evident (mis)use of static geographic information at a resolution lower than the nesting level for which the core is performing computation. A brief discussion of the high-level modular architecture of the model is presented as well as methods utilized to identify the cause of these problems. Presented here are the initial results from a research grant, ``A Pilot Project to Investigate Wake Vortex Patterns and Weather Patterns at the Atlantic City Airport by the Richard Stockton College of NJ and the FAA'' [Preview Abstract] |
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L1.00050: Molecular Dynamic Simulations on Surface Tension of Methanol Abdalla Obeidat Molecular dynamic simulations have been performed to study the surface tension of methanol at low temperatures. Six different models of methanol have been studied to compute the surface tension of different models. The models have been used to predict the surface tensions are: OPLS, Gromos 96, H1, J1, J2, and van Leeuwen model. Our results show that the most accurate model compared to true methanol was van Leeuwen model. The results were fitted to a straight line to predict other data of surface tension at specific temperature. The simulation were performed using the Gromacs package at temperatures: 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, and 300 K. [Preview Abstract] |
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L1.00051: Stochastic coalescence in finite systems: an algorithm for the numerical solution of the multivariate master equation. Lester Alfonso, Jose Zamora, Pedro Cruz The stochastic approach to coagulation considers the coalescence process going in a system of a finite number of particles enclosed in a finite volume. Within this approach, the full description of the system can be obtained from the solution of the multivariate master equation, which models the evolution of the probability distribution of the state vector for the number of particles of a given mass. Unfortunately, due to its complexity, only limited results were obtained for certain type of kernels and monodisperse initial conditions. In this work, a novel numerical algorithm for the solution of the multivariate master equation for stochastic coalescence that works for any type of kernels and initial conditions is introduced. The performance of the method was checked by comparing the numerically calculated particle mass spectrum with analytical solutions obtained for the constant and sum kernels, with an excellent correspondence between the analytical and numerical solutions. In order to increase the speedup of the algorithm, software parallelization techniques with OpenMP standard were used, along with an implementation in order to take advantage of new accelerator technologies. Simulations results show an important speedup of the parallelized algorithms. [Preview Abstract] |
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L1.00052: Use of Hilbert Curves in Parallelized CUDA code: Interaction of Interstellar Atoms with the Heliosphere Anthony DeStefano, Jacob Heerikhuisen Fully 3Dparticle simulations can be a computationally and memory expensive task, especially when high resolution grid cells are required. The problem becomes further complicated when parallelization is needed. In this work we focus on computational methods to solve these difficulties. Hilbert curves are used to map the 3D particle space to the 1D contiguous memory space. This method of organization allows for minimized cache misses on the GPU as well as a sorted structure that is equivalent to an octal tree data structure. This type of sorted structure is attractive for uses in adaptive mesh implementations due to the logarithm search time. Implementations using the Message Passing Interface (MPI) library and NVIDIA's parallel computing platform CUDA will be compared, as MPI is commonly used on server nodes with many CPU's. We will also compare static grid structures with those of adaptive mesh structures. The physical test bed will be simulating heavy interstellar atoms interacting with a background plasma, the heliosphere, simulated from fully consistent coupled MHD/kinetic particle code. It is known that charge exchange is an important factor in space plasmas, specifically it modifies the structure of the heliosphere itself. [Preview Abstract] |
(Author Not Attending)
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L1.00053: A GPU Accelerated Simulation Program for Electron Cooling Process He Zhang, He Huang, Rui Li, Jie Chen, Li-Shi Luo Electron cooling is essential to achieve high luminosity in the medium energy electron ion collider (MIEC) project at Jefferson Lab. Bunched electron beam with energy above 50 MeV is used to cool coasting and/or bunched ion beams. Although the conventional electron cooling technique has been widely used, such an implementation in MEIC is still challenging. We are developing a simulation program for the electron cooling process to fulfill the need of the electron cooling system design for MEIC. The program simulates the evolution of the ion beam under the intrabeam scattering (IBS) effect and the electron cooling effect using Monte Carlo method. To accelerate the calculation, the program is developed on a GPU platform. We will present some preliminary simulation results. [Preview Abstract] |
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L1.00054: A Simple Pythagorean Interpretation of E$^{2} =$ p$^{2}$c$^{2} +$ (mc$^{2})^{2}$ J.A. Tobar, C.I. Guillen, E.L. Vargas, V.M. Andrianarijaona We are considering the relationship between the relativistic energy, the momentum, and the rest energy, $E^{2}=p^{2}c^{2} +$\textit{ (mc}$^{2})^{2},$ and using geometrical means to analyze each individual portion in a spatial setting. The aforementioned equation suggests that \textit{pc} and \textit{mc}$^{2}$ could be thought of as the two axis of a plane. According to de Broglie's hypothesis $\lambda =h/p$ therefore suggesting that the \textit{pc}-axis is connected to the wave properties of a moving object, and subsequently, the \textit{mc}$^{2}$-axis is connected to the particle properties such as its moment of inertia. Consequently, these two axes could represent the particle (matter) and wave properties of the moving object. An overview of possible models and meaningful interpretations, which agree with Dirac's prediction of the electron's magnetic moment, will be presented. [Preview Abstract] |
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L1.00055: ENERGY AND RESEARCH APPLICATIONS |
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L1.00056: Characteristics of Fluorine-doped tin oxide thin films grown by Streaming process for Electrodeless Electrochemical Deposition Gbadebo Yusuf, Farnood Khalilzadeh-Rezaie, Justin W. Cleary, Isaiah O. Oladeji, Koukou Suu, Winston V. Schoenfeld, Robert E. Peale, Ayodeji O. Awodugba This work investigated the characteristics of SnO$_{2}$: F films grown by Streaming Process for Electrodeless Electrochemical Deposition (SPEED). Stannic chloride (SnCl$_{4})$ and ammonium fluoride (NH$_{4}$F) was dissolved in a mixture of deionized water and organic solvents. The preheated substrate temperature was varied between 450 and 530$^{\circ}$ C. High quality SnO$_{2}$: F films were grown at all the substrate temperatures studied. The typical film thickness was 250 nm. XRD shows that the grown films are polycrystalline SnO2 with a tetragonal crystal structure. The average optical transmission of the films was around 93{\%} throughout the wavelength of 400 to 1000 nm. The lowest electrical resistivity achieved was 6 x 10$^{-4} \Omega$ cm. The Hall measurements showed that the film is an n-type semiconductor, with the highest carrier mobility of 8.3 cm$^{2}$/V.s, and concentration of 1 x 10$^{21}$ cm$^{-3}$. The direct band gap was determined to be 4 eV from the transmittance spectrum. [Preview Abstract] |
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L1.00057: Characterization and Development of BaZrO3/NiO Composites for use as Anodes in Proton Conducting SOFCs Islam Khan, Kelly Dillon, Amber Genau, Renato Camata Solid oxide fuel cells (SOFCs) are devices that convert chemical energy to electrical energy directly through oxidation of the fuel. The basic structure of SOFCs consists of three parts: an anode and a cathode that are separated by an electrolyte. The focus of this work is on developing and characterizing anode materials for proton-conducting SOFCs which use ceramic material BaZrO3 as the electrolyte. These anodes are made using a BaZrO3-Ni composite, known as a cermet (ceramic and metal), which has shown potential as anode materials for these devices. The conventional method for making BaZrO3-Ni cermets consist of an intermediate stage composite material BaZrO3-NiO that have a strong influence on the final properties of the anode. Composites consisting of the two phases, BaZrO3 and NiO, with different weight ratios were made into pellets (0.5-inch diameter) using a mechanical mixing method followed by sintering at high temperatures. Optical microscopy image analysis showed grain growth in both phases as well as presence of porosity. The effect of sintering temperature on the densification of the composite powders was analyzed and the results showed that higher temperature enabled higher densification of the composites. Electrochemical impedance spectroscopy indicated there are two factors that contribute to the impedance in the structure of the composite materials, and possible sources for each factor are discussed. [Preview Abstract] |
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