National Library of Energy BETA

Sample records for random chuck holes

  1. Micromachined silicon electrostatic chuck

    DOE Patents [OSTI]

    Anderson, Robert A. (Albuquerque, NM); Seager, Carleton H. (Albuquerque, NM)

    1996-01-01

    An electrostatic chuck is faced with a patterned silicon plate 11, created y micromachining a silicon wafer, which is attached to a metallic base plate 13. Direct electrical contact between the chuck face 15 (patterned silicon plate's surface) and the silicon wafer 17 it is intended to hold is prevented by a pattern of flat-topped silicon dioxide islands 19 that protrude less than 5 micrometers from the otherwise flat surface of the chuck face 15. The islands 19 may be formed in any shape. Islands may be about 10 micrometers in diameter or width and spaced about 100 micrometers apart. One or more concentric rings formed around the periphery of the area between the chuck face 15 and wafer 17 contain a low-pressure helium thermal-contact gas used to assist heat removal during plasma etching of a silicon wafer held by the chuck. The islands 19 are tall enough and close enough together to prevent silicon-to-silicon electrical contact in the space between the islands, and the islands occupy only a small fraction of the total area of the chuck face 15, typically 0.5 to 5 percent. The pattern of the islands 19, together with at least one hole 12 bored through the silicon veneer into the base plate, will provide sufficient gas-flow space to allow the distribution of the helium thermal-contact gas.

  2. Micromachined silicon electrostatic chuck

    DOE Patents [OSTI]

    Anderson, R.A.; Seager, C.H.

    1996-12-10

    An electrostatic chuck is faced with a patterned silicon plate, created by micromachining a silicon wafer, which is attached to a metallic base plate. Direct electrical contact between the chuck face (patterned silicon plate`s surface) and the silicon wafer it is intended to hold is prevented by a pattern of flat-topped silicon dioxide islands that protrude less than 5 micrometers from the otherwise flat surface of the chuck face. The islands may be formed in any shape. Islands may be about 10 micrometers in diameter or width and spaced about 100 micrometers apart. One or more concentric rings formed around the periphery of the area between the chuck face and wafer contain a low-pressure helium thermal-contact gas used to assist heat removal during plasma etching of a silicon wafer held by the chuck. The islands are tall enough and close enough together to prevent silicon-to-silicon electrical contact in the space between the islands, and the islands occupy only a small fraction of the total area of the chuck face, typically 0.5 to 5 percent. The pattern of the islands, together with at least one hole bored through the silicon veneer into the base plate, will provide sufficient gas-flow space to allow the distribution of the helium thermal-contact gas. 6 figs.

  3. Compliant layer chucking surface

    DOE Patents [OSTI]

    Blaedel, Kenneth L. (Dublin, CA); Spence, Paul A. (Pleasanton, CA); Thompson, Samuel L. (Pleasanton, CA)

    2004-12-28

    A method and apparatus are described wherein a thin layer of complaint material is deposited on the surface of a chuck to mitigate the deformation that an entrapped particle might cause in the part, such as a mask or a wafer, that is clamped to the chuck. The harder particle will embed into the softer layer as the clamping pressure is applied. The material composing the thin layer could be a metal or a polymer for vacuum or electrostatic chucks. It may be deposited in various patterns to affect an interrupted surface, such as that of a "pin" chuck, thereby reducing the probability of entrapping a particle.

  4. Chuck Kessel Wins the 2015 Fusion Technology Award | Princeton Plasma

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Physics Lab Chuck Kessel Wins the 2015 Fusion Technology Award By Raphael Rosen July 9, 2015 Tweet Widget Google Plus One Share on Facebook Chuck Kessel (Photo by Elle Starkman/ PPPL Office of Communications) Chuck Kessel Gallery: Chuck Kessel Chuck Kessel Chuck Kessel Chuck Kessel Chuck Kessel, a principal engineer at the U.S. Department of Energy's Princeton Plasma Physics Laboratory (PPPL), has won the 2015 Fusion Technology Award. The honor, from the Institute of Electrical and

  5. Electrostatically screened, voltage-controlled electrostatic chuck

    DOE Patents [OSTI]

    Klebanoff, Leonard Elliott (San Ramon, CA)

    2001-01-01

    Employing an electrostatically screened, voltage-controlled electrostatic chuck particularly suited for holding wafers and masks in sub-atmospheric operations will significantly reduce the likelihood of contaminant deposition on the substrates. The electrostatic chuck includes (1) an insulator block having a outer perimeter and a planar surface adapted to support the substrate and comprising at least one electrode (typically a pair of electrodes that are embedded in the insulator block), (2) a source of voltage that is connected to the at least one electrode, (3) a support base to which the insulator block is attached, and (4) a primary electrostatic shield ring member that is positioned around the outer perimeter of the insulator block. The electrostatic chuck permits control of the voltage of the lithographic substrate; in addition, it provides electrostatic shielding of the stray electric fields issuing from the sides of the electrostatic chuck. The shielding effectively prevents electric fields from wrapping around to the upper or front surface of the substrate, thereby eliminating electrostatic particle deposition.

  6. Chuck Kessel Wins the 2015 Fusion Technology Award | Princeton Plasma

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Physics Lab Chuck Kessel Wins the 2015 Fusion Technology Award By Raphael Rosen July 13, 2015 Tweet Widget Google Plus One Share on Facebook Chuck Kessel, a principal engineer at the U.S. Department of Energy's Princeton Plasma Physics Laboratory (PPPL), has won the 2015 Fusion Technology Award. The honor, from the Institute of Electrical and Electronics Engineers' (IEEE) Nuclear and Plasma Sciences Society, recognizes outstanding contributions to fusion engineering and technology.

  7. Defense Secretary Chuck Hagel visits Sandia | National Nuclear Security

    National Nuclear Security Administration (NNSA)

    Administration Secretary Chuck Hagel visits Sandia | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Countering Nuclear Terrorism About Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Library Bios Congressional Testimony Fact Sheets Newsletters Press Releases Photo Gallery Jobs Apply

  8. Charles "Chuck" Farrar to receive DeMichele Award

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Farrar to receive DeMichele Award Charles "Chuck" Farrar to receive DeMichele Award The award is presented for demonstrated "exemplary service and support of promoting the science and educational aspects of modal analysis technology." November 21, 2012 Charles "Chuck" Farrar Charles "Chuck" Farrar Charles "Chuck" Farrar, leader of LANL's Engineering Institute, will receive the 2013 DeMichele Award from the Society for Experimental Mechanics. The

  9. Dr. Chuck Ross gives final lecture of JLab Spring Science Series (Daily

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Press) | Jefferson Lab https://www.jlab.org/news/articles/dr-chuck-ross-gives-final-lecture-jlab-spring-science-series-daily-press For Lee, acoustics were sound of defeat An authority on "acoustic shadows" discusses the impact of sound on the Civil War. By David Macaulay, Daily Press March 28, 2008 NEWPORT NEWS - It won't be music to the ears of traditionalists, but Civil War Confederate Gen. Robert E. Lee might have owed some of his success - not to mention his demise - to

  10. Random array grid collimator

    DOE Patents [OSTI]

    Fenimore, E.E.

    1980-08-22

    A hexagonally shaped quasi-random no-two-holes touching grid collimator. The quasi-random array grid collimator eliminates contamination from small angle off-axis rays by using a no-two-holes-touching pattern which simultaneously provides for a self-supporting array increasng throughput by elimination of a substrate. The presentation invention also provides maximum throughput using hexagonally shaped holes in a hexagonal lattice pattern for diffraction limited applications. Mosaicking is also disclosed for reducing fabrication effort.

  11. On coupling impedances of pumping holes

    SciTech Connect (OSTI)

    Kurennoy, S.

    1993-04-01

    Coupling impedances of a single small hole in vacuum-chamber walls have been calculated at low frequencies. To generalize these results for higher frequencies and/or larger holes one needs to solve coupled integral equations for the effective currents. These equations are solved for two specific hole shapes. The effects of many holes at high frequencies where the impedances are not additive are studied using a perturbation-theory method. The periodic versus random distributions of the pumping holes in the Superconducting Super Collider liner are compared.

  12. Quasi-random array imaging collimator

    DOE Patents [OSTI]

    Fenimore, E.E.

    1980-08-20

    A hexagonally shaped quasi-random no-two-holes-touching imaging collimator. The quasi-random array imaging collimator eliminates contamination from small angle off-axis rays by using a no-two-holes-touching pattern which simultaneously provides for a self-supporting array increasing throughput by elimination of a substrate. The present invention also provides maximum throughput using hexagonally shaped holes in a hexagonal lattice pattern for diffraction limited applications. Mosaicking is also disclosed for reducing fabrication effort.

  13. BLACK HOLE FORAGING: FEEDBACK DRIVES FEEDING

    SciTech Connect (OSTI)

    Dehnen, Walter; King, Andrew, E-mail: wd11@leicester.ac.uk, E-mail: ark@astro.le.ac.uk [Theoretical Astrophysics Group, University of Leicester, Leicester LE1 7RH (United Kingdom)] [Theoretical Astrophysics Group, University of Leicester, Leicester LE1 7RH (United Kingdom)

    2013-11-10

    We suggest a new picture of supermassive black hole (SMBH) growth in galaxy centers. Momentum-driven feedback from an accreting hole gives significant orbital energy, but little angular momentum to the surrounding gas. Once central accretion drops, the feedback weakens and swept-up gas falls back toward the SMBH on near-parabolic orbits. These intersect near the black hole with partially opposed specific angular momenta, causing further infall and ultimately the formation of a small-scale accretion disk. The feeding rates into the disk typically exceed Eddington by factors of a few, growing the hole on the Salpeter timescale and stimulating further feedback. Natural consequences of this picture include (1) the formation and maintenance of a roughly toroidal distribution of obscuring matter near the hole; (2) random orientations of successive accretion disk episodes; (3) the possibility of rapid SMBH growth; (4) tidal disruption of stars and close binaries formed from infalling gas, resulting in visible flares and ejection of hypervelocity stars; (5) super-solar abundances of the matter accreting on to the SMBH; and (6) a lower central dark-matter density, and hence annihilation signal, than adiabatic SMBH growth implies. We also suggest a simple subgrid recipe for implementing this process in numerical simulations.

  14. ULTRAMASSIVE BLACK HOLE COALESCENCE

    SciTech Connect (OSTI)

    Khan, Fazeel Mahmood; Holley-Bockelmann, Kelly; Berczik, Peter E-mail: k.holley@vanderbilt.edu

    2015-01-10

    Although supermassive black holes (SMBHs) correlate well with their host galaxies, there is an emerging view that outliers exist. Henize 2-10, NGC4889, and NGC1277 are examples of SMBHs at least an order of magnitude more massive than their host galaxy suggests. The dynamical effects of such ultramassive central black holes is unclear. Here, we perform direct N-body simulations of mergers of galactic nuclei where one black hole is ultramassive to study the evolution of the remnant and the black hole dynamics in this extreme regime. We find that the merger remnant is axisymmetric near the center, while near the large SMBH influence radius, the galaxy is triaxial. The SMBH separation shrinks rapidly due to dynamical friction, and quickly forms a binary black hole; if we scale our model to the most massive estimate for the NGC1277 black hole, for example, the timescale for the SMBH separation to shrink from nearly a kiloparsec to less than a parsec is roughly 10Myr. By the time the SMBHs form a hard binary, gravitational wave emission dominates, and the black holes coalesce in a mere few Myr. Curiously, these extremely massive binaries appear to nearly bypass the three-body scattering evolutionary phase. Our study suggests that in this extreme case, SMBH coalescence is governed by dynamical friction followed nearly directly by gravitational wave emission, resulting in a rapid and efficient SMBH coalescence timescale. We discuss the implications for gravitational wave event rates and hypervelocity star production.

  15. Laser bottom hole assembly

    SciTech Connect (OSTI)

    Underwood, Lance D; Norton, Ryan J; McKay, Ryan P; Mesnard, David R; Fraze, Jason D; Zediker, Mark S; Faircloth, Brian O

    2014-01-14

    There is provided for laser bottom hole assembly for providing a high power laser beam having greater than 5 kW of power for a laser mechanical drilling process to advance a borehole. This assembly utilizes a reverse Moineau motor type power section and provides a self-regulating system that addresses fluid flows relating to motive force, cooling and removal of cuttings.

  16. Black hole magnetospheres

    SciTech Connect (OSTI)

    Nathanail, Antonios; Contopoulos, Ioannis

    2014-06-20

    We investigate the structure of the steady-state force-free magnetosphere around a Kerr black hole in various astrophysical settings. The solution Ψ(r, θ) depends on the distributions of the magnetic field line angular velocity ω(Ψ) and the poloidal electric current I(Ψ). These are obtained self-consistently as eigenfunctions that allow the solution to smoothly cross the two singular surfaces of the problem, the inner light surface inside the ergosphere, and the outer light surface, which is the generalization of the pulsar light cylinder. Magnetic field configurations that cross both singular surfaces (e.g., monopole, paraboloidal) are uniquely determined. Configurations that cross only one light surface (e.g., the artificial case of a rotating black hole embedded in a vertical magnetic field) are degenerate. We show that, similar to pulsars, black hole magnetospheres naturally develop an electric current sheet that potentially plays a very important role in the dissipation of black hole rotational energy and in the emission of high-energy radiation.

  17. Relativistic Random Phase Approximation At Finite Temperature

    SciTech Connect (OSTI)

    Niu, Y. F.; Paar, N.; Vretenar, D.; Meng, J.

    2009-08-26

    The fully self-consistent finite temperature relativistic random phase approximation (FTRRPA) has been established in the single-nucleon basis of the temperature dependent Dirac-Hartree model (FTDH) based on effective Lagrangian with density dependent meson-nucleon couplings. Illustrative calculations in the FTRRPA framework show the evolution of multipole responses of {sup 132}Sn with temperature. With increased temperature, in both monopole and dipole strength distributions additional transitions appear in the low energy region due to the new opened particle-particle and hole-hole transition channels.

  18. Thermal Gradient Holes | Open Energy Information

    Open Energy Info (EERE)

    Holes Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Thermal Gradient Holes Details Activities (67) Areas (48) Regions (4) NEPA(33) Exploration...

  19. Slim Holes | Open Energy Information

    Open Energy Info (EERE)

    are typically drilled using a diamond coated bit, core samples are often collected, and reservoir properties measured. Slim holes can range from 3-6'' in diameter and be...

  20. Close encounters of three black holes

    SciTech Connect (OSTI)

    Campanelli, Manuela; Lousto, Carlos O.; Zlochower, Yosef

    2008-05-15

    We present the first fully relativistic long-term numerical evolutions of three equal-mass black holes in a system consisting of a third black hole in a close orbit about a black-hole binary. These close-three-black-hole systems have very different merger dynamics from black-hole binaries; displaying complex trajectories, a redistribution of energy that can impart substantial kicks to one of the holes, distinctive waveforms, and suppression of the emitted gravitational radiation. In one configuration the binary is quickly disrupted and the individual holes follow complicated trajectories and merge with the third hole in rapid succession, while in another, the binary completes a half-orbit before the initial merger of one of the members with the third black hole, and the resulting two-black-hole system forms a highly elliptical, well separated binary that shows no significant inspiral for (at least) the first t{approx}1000M of evolution.

  1. Quantum Criticality and Black Holes

    ScienceCinema (OSTI)

    Sachdev, Subir [Harvard University, Cambridge, Massachusetts, United States

    2009-09-01

    I will describe the behavior of a variety of condensed matter systems in the vicinity of zero temperature quantum phase transitions. There is a remarkable analogy between the hydrodynamics of such systems and the quantum theory of black holes. I will show how insights from this analogy have shed light on recent experiments on the cuprate high temperature superconductors. Studies of new materials and trapped ultracold atoms are yielding new quantum phases, with novel forms of quantum entanglement. Some materials are of technological importance: e.g. high temperature superconductors. Exact solutions via black hole mapping have yielded first exact results for transport coefficients in interacting many-body systems, and were valuable in determining general structure of hydrodynamics. Theory of VBS order and Nernst effect in cuprates. Tabletop 'laboratories for the entire universe': quantum mechanics of black holes, quark-gluon plasma, neutrons stars, and big-bang physics.

  2. Woods Hole Research Center Wind Turbine | Open Energy Information

    Open Energy Info (EERE)

    Hole Research Center Wind Turbine Jump to: navigation, search Name Woods Hole Research Center Wind Turbine Facility Woods Hole Research Center Wind Turbine Sector Wind energy...

  3. From Pinholes to Black Holes

    SciTech Connect (OSTI)

    Fenimore, Edward E.

    2014-10-06

    Pinhole photography has made major contributions to astrophysics through the use of coded apertures. Coded apertures were instrumental in locating gamma-ray bursts and proving that they originate in faraway galaxies, some from the birth of black holes from the first stars that formed just after the big bang.

  4. High precision, rapid laser hole drilling

    DOE Patents [OSTI]

    Chang, Jim J.; Friedman, Herbert W.; Comaskey, Brian J.

    2007-03-20

    A laser system produces a first laser beam for rapidly removing the bulk of material in an area to form a ragged hole. The laser system produces a second laser beam for accurately cleaning up the ragged hole so that the final hole has dimensions of high precision.

  5. High precision, rapid laser hole drilling

    DOE Patents [OSTI]

    Chang, Jim J.; Friedman, Herbert W.; Comaskey, Brian J.

    2013-04-02

    A laser system produces a first laser beam for rapidly removing the bulk of material in an area to form a ragged hole. The laser system produces a second laser beam for accurately cleaning up the ragged hole so that the final hole has dimensions of high precision.

  6. High precision, rapid laser hole drilling

    DOE Patents [OSTI]

    Chang, Jim J.; Friedman, Herbert W.; Comaskey, Brian J.

    2005-03-08

    A laser system produces a first laser beam for rapidly removing the bulk of material in an area to form a ragged hole. The laser system produces a second laser beam for accurately cleaning up the ragged hole so that the final hole has dimensions of high precision.

  7. Detecting small holes in packages

    DOE Patents [OSTI]

    Kronberg, James W. (Aiken, SC); Cadieux, James R. (Aiken, SC)

    1996-01-01

    A package containing a tracer gas, and a method for determining the presence of a hole in the package by sensing the presence of the gas outside the package. The preferred tracer gas, especially for food packaging, is sulfur hexafluoride. A quantity of the gas is added to the package and the package is closed. The concentration of the gas in the atmosphere outside the package is measured and compared to a predetermined value of the concentration of the gas in the absence of the package. A measured concentration greater than the predetermined value indicates the presence of a hole in the package. Measuring may be done in a chamber having a lower pressure than that in the package.

  8. Detecting small holes in packages

    DOE Patents [OSTI]

    Kronberg, J.W.; Cadieux, J.R.

    1996-03-19

    A package containing a tracer gas, and a method for determining the presence of a hole in the package by sensing the presence of the gas outside the package are disclosed. The preferred tracer gas, especially for food packaging, is sulfur hexafluoride. A quantity of the gas is added to the package and the package is closed. The concentration of the gas in the atmosphere outside the package is measured and compared to a predetermined value of the concentration of the gas in the absence of the package. A measured concentration greater than the predetermined value indicates the presence of a hole in the package. Measuring may be done in a chamber having a lower pressure than that in the package. 3 figs.

  9. Down hole periodic seismic generator

    DOE Patents [OSTI]

    Hardee, Harry C. (Albuquerque, NM); Hills, Richard G. (Las Cruces, NM); Striker, Richard P. (Albuquerque, NM)

    1989-01-01

    A down hole periodic seismic generator system for transmitting variable frequency, predominantly shear-wave vibration into earth strata surrounding a borehole. The system comprises a unitary housing operably connected to a well head by support and electrical cabling and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a variable speed pneumatic oscillator and a self-contained pneumatic reservoir for producing a frequency-swept seismic output over a discrete frequency range.

  10. Submicron patterned metal hole etching

    DOE Patents [OSTI]

    McCarthy, Anthony M. (Menlo Park, CA); Contolini, Robert J. (Lake Oswego, OR); Liberman, Vladimir (Needham, MA); Morse, Jeffrey (Martinez, CA)

    2000-01-01

    A wet chemical process for etching submicron patterned holes in thin metal layers using electrochemical etching with the aid of a wetting agent. In this process, the processed wafer to be etched is immersed in a wetting agent, such as methanol, for a few seconds prior to inserting the processed wafer into an electrochemical etching setup, with the wafer maintained horizontal during transfer to maintain a film of methanol covering the patterned areas. The electrochemical etching setup includes a tube which seals the edges of the wafer preventing loss of the methanol. An electrolyte composed of 4:1 water: sulfuric is poured into the tube and the electrolyte replaces the wetting agent in the patterned holes. A working electrode is attached to a metal layer of the wafer, with reference and counter electrodes inserted in the electrolyte with all electrodes connected to a potentiostat. A single pulse on the counter electrode, such as a 100 ms pulse at +10.2 volts, is used to excite the electrochemical circuit and perform the etch. The process produces uniform etching of the patterned holes in the metal layers, such as chromium and molybdenum of the wafer without adversely effecting the patterned mask.

  11. Black hole mimickers: Regular versus singular behavior

    SciTech Connect (OSTI)

    Lemos, Jose P. S.; Zaslavskii, Oleg B.

    2008-07-15

    Black hole mimickers are possible alternatives to black holes; they would look observationally almost like black holes but would have no horizon. The properties in the near-horizon region where gravity is strong can be quite different for both types of objects, but at infinity it could be difficult to discern black holes from their mimickers. To disentangle this possible confusion, we examine the near-horizon properties, and their connection with far away asymptotic properties, of some candidates to black mimickers. We study spherically symmetric uncharged or charged but nonextremal objects, as well as spherically symmetric charged extremal objects. Within the uncharged or charged but nonextremal black hole mimickers, we study nonextremal {epsilon}-wormholes on the threshold of the formation of an event horizon, of which a subclass are called black foils, and gravastars. Within the charged extremal black hole mimickers we study extremal {epsilon}-wormholes on the threshold of the formation of an event horizon, quasi-black holes, and wormholes on the basis of quasi-black holes from Bonnor stars. We elucidate whether or not the objects belonging to these two classes remain regular in the near-horizon limit. The requirement of full regularity, i.e., finite curvature and absence of naked behavior, up to an arbitrary neighborhood of the gravitational radius of the object enables one to rule out potential mimickers in most of the cases. A list ranking the best black hole mimickers up to the worst, both nonextremal and extremal, is as follows: wormholes on the basis of extremal black holes or on the basis of quasi-black holes, quasi-black holes, wormholes on the basis of nonextremal black holes (black foils), and gravastars. Since in observational astrophysics it is difficult to find extremal configurations (the best mimickers in the ranking), whereas nonextremal configurations are really bad mimickers, the task of distinguishing black holes from their mimickers seems to be less difficult than one could think of it.

  12. Boson shells harboring charged black holes

    SciTech Connect (OSTI)

    Kleihaus, Burkhard; Kunz, Jutta; Laemmerzahl, Claus; List, Meike

    2010-11-15

    We consider boson shells in scalar electrodynamics coupled to Einstein gravity. The interior of the shells can be empty space, or harbor a black hole or a naked singularity. We analyze the properties of these types of solutions and determine their domains of existence. We investigate the energy conditions and present mass formulae for the composite black hole-boson shell systems. We demonstrate that these types of solutions violate black hole uniqueness.

  13. Black hole birth captured by cosmic voyeurs

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Black hole birth captured by cosmic voyeurs Black hole birth captured by cosmic voyeurs The RAPTOR system is a network of small robotic observatories that scan the skies for optical anomalies such as flashes emanating from a star in its death throes as it collapses and becomes a black hole. November 21, 2013 Los Alamos National Laboratory astrophysicist Tom Vestrand poses with a telescope array that is part of the RAPTOR (RAPid Telescopes for Optical Response) system. RAPTOR is an intelligent

  14. Charles "Chuck" Farrar to receive DeMichele Award

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    capabilities with novel sensing systems and information technology. It includes a formal international partnership, The Engineering Institute-Korea. Farrar's professional...

  15. Probing Core-Hole Localization in Molecular Nitrogen

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Probing Core-Hole Localization in Molecular Nitrogen Probing Core-Hole Localization in Molecular Nitrogen Print Wednesday, 25 February 2009 00:00 The behavior of the core hole...

  16. Two Electron Holes in Hematite Facilitate Water Splitting

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    been suspected that in hematite, two different holes are formed with different water-splitting power. The existence of different types of holes with disparate reactivity...

  17. Core Holes At Long Valley Caldera Geothermal Area (Urban, Et...

    Open Energy Info (EERE)

    Technique Core Holes Activity Date 1986 - 1986 Usefulness useful DOE-funding Unknown Exploration Basis After several temperature-gradient holes were drilled in 1982 to the...

  18. Category:Thermal Gradient Holes | Open Energy Information

    Open Energy Info (EERE)

    in category "Thermal Gradient Holes" This category contains only the following page. T Thermal Gradient Holes Retrieved from "http:en.openei.orgwindex.php?titleCategory:T...

  19. Category:Open-Hole Techniques | Open Energy Information

    Open Energy Info (EERE)

    Open-Hole Techniques Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermalpower.jpg Looking for the Open-Hole Techniques page? For detailed information on...

  20. Two Electron Holes in Hematite Facilitate Water Splitting

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Two Electron Holes in Hematite Facilitate Water Splitting Two Electron Holes in Hematite Facilitate Water Splitting Print Wednesday, 26 September 2012 00:00 Hydrogen is an...

  1. Thermal Gradient Holes At Tungsten Mountain Area (Kratt, Et Al...

    Open Energy Info (EERE)

    Gradient Holes Activity Date Usefulness useful DOE-funding Unknown Notes twenty-three gold exploration holes were drilled by Newcrest Resources, Inc. during 2005 and 2006 along...

  2. Compound and Elemental Analysis At Seven Mile Hole Area (Larson...

    Open Energy Info (EERE)

    Seven Mile Hole Area (Larson, Et Al., 2009) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Compound and Elemental Analysis At Seven Mile Hole...

  3. Slim Holes for Small Power Plants

    SciTech Connect (OSTI)

    Finger, John T.

    1999-08-06

    Geothermal research study at Sandia National Laboratories has conducted a program in slimhole drilling research since 1992. Although our original interest focused on slim holes as an exploration method, it has also become apparent that they have substantial potential for driving small-scale, off-grid power plants. This paper summarizes Sandia's slim-hole research program, describes technology used in a ''typical'' slimhole drilling project, presents an evaluation of using slim holes for small power plants, and lists some of the research topics that deserve further investigation.

  4. Radioactive hot cell access hole decontamination machine

    DOE Patents [OSTI]

    Simpson, William E.

    1982-01-01

    Radioactive hot cell access hole decontamination machine. A mobile housing has an opening large enough to encircle the access hole and has a shielding door, with a door opening and closing mechanism, for uncovering and covering the opening. The housing contains a shaft which has an apparatus for rotating the shaft and a device for independently translating the shaft from the housing through the opening and access hole into the hot cell chamber. A properly sized cylindrical pig containing wire brushes and cloth or other disks, with an arrangement for releasably attaching it to the end of the shaft, circumferentially cleans the access hole wall of radioactive contamination and thereafter detaches from the shaft to fall into the hot cell chamber.

  5. Spectral line broadening in magnetized black holes

    SciTech Connect (OSTI)

    Frolov, Valeri P.; Shoom, Andrey A.; Tzounis, Christos E-mail: ashoom@ualberta.ca

    2014-07-01

    We consider weakly magnetized non-rotating black holes. In the presence of a regular magnetic field the motion of charged particles in the vicinity of a black hole is modified. As a result, the position of the innermost stable circular orbit (ISCO) becomes closer to the horizon. When the Lorentz force is repulsive (directed from the black hole) the ISCO radius can reach the gravitational radius. In the process of accretion charged particles (ions) of the accreting matter can be accumulated near their ISCO, while neutral particles fall down to the black hole after they reach 6M radius. The sharp spectral line Fe α, emitted by iron ions at such orbits, is broadened when the emission is registered by a distant observer. In this paper we study this broadening effect and discuss how one can extract information concerning the strength of the magnetic field from the observed spectrum.

  6. Rotating black hole thermodynamics with a particle probe

    SciTech Connect (OSTI)

    Gwak, Bogeun; Lee, Bum-Hoon

    2011-10-15

    The thermodynamics of Myers-Perry black holes in general dimensions are studied using a particle probe. When undergoing particle absorption, the changes of the entropy and irreducible mass are shown to be dependent on the particle radial momentum. The black hole thermodynamic behaviors are dependent on dimensionality for specific rotations. For a 4-dimensional Kerr black hole, its black hole properties are maintained for any particle absorption. 5-dimensional black holes can avoid a naked ring singularity by absorbing a particle in specific momenta ranges. Black holes over 6 dimensions become ultraspinning black holes through a specific form of particle absorption. The microscopical changes are interpreted in limited cases of Myers-Perry black holes using Kerr/CFT correspondence. We systematically describe the black hole properties changed by particle absorption in all dimensions.

  7. Remote down-hole well telemetry

    DOE Patents [OSTI]

    Briles, Scott D.; Neagley, Daniel L.; Coates, Don M.; Freund, Samuel M.

    2004-07-20

    The present invention includes an apparatus and method for telemetry communication with oil-well monitoring and recording instruments located in the vicinity of the bottom of gas or oil recovery pipes. Such instruments are currently monitored using electrical cabling that is inserted into the pipes; cabling has a short life in this environment, and requires periodic replacement with the concomitant, costly shutdown of the well. Modulated reflectance, a wireless communication method that does not require signal transmission power from the telemetry package will provide a long-lived and reliable way to monitor down-hole conditions. Normal wireless technology is not practical since batteries and capacitors have to frequently be replaced or recharged, again with the well being removed from service. RF energy generated above ground can also be received, converted and stored down-hole without the use of wires, for actuating down-hole valves, as one example. Although modulated reflectance reduces or eliminates the loss of energy at the sensor package because energy is not consumed, during the transmission process, additional stored extra energy down-hole is needed.

  8. Optical orientation of holes in strained nanostructures

    SciTech Connect (OSTI)

    Averkiev, N. S.; Sablina, N. I.

    2008-03-15

    A theory describing the optical orientation and Hanle effect for holes in quantum wells or quantum dots based on cubic semiconductors is developed. It is demonstrated that the presence of internal or external strain in quantum-confinement heterostructures leads to the dependence of the Hanle effect on the orientation of the magnetic field with respect to the heterostructure growth axis.

  9. Thermal Gradient Holes At Chena Area (Erkan, Et. Al., 2008) ...

    Open Energy Info (EERE)

    Holes Activity Date Usefulness useful DOE-funding Unknown Notes MULTI-STAGE DRILLING Once a hole is drilled the natural-state pressure distribution with depth is essentially...

  10. V-193: Barracuda SSL VPN Input Validation Hole Permits Cross...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    3: Barracuda SSL VPN Input Validation Hole Permits Cross-Site Scripting Attacks V-193: Barracuda SSL VPN Input Validation Hole Permits Cross-Site Scripting Attacks July 5, 2013 -...

  11. Photodriving Water Oxidation Catalysts: Extending Hole Lifetimes | ANSER

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Center | Argonne-Northwestern National Laboratory Photodriving Water Oxidation Catalysts: Extending Hole Lifetimes Home > Research > ANSER Research Highlights > Photodriving Water Oxidation Catalysts: Extending Hole Lifetimes

  12. Thermal Gradient Holes At Long Valley Caldera Geothermal Area...

    Open Energy Info (EERE)

    consisting of several holes including: The CH8-10 thermal-gradient holes drilled by the U.S. Geological Survey prior to 1978 to relatively shallow depths ranging from about 55 to...

  13. Probing Core-Hole Localization in Molecular Nitrogen

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Probing Core-Hole Localization in Molecular Nitrogen Probing Core-Hole Localization in Molecular Nitrogen Print Wednesday, 25 February 2009 00:00 The behavior of the core hole created in molecular x-ray photoemission experiments has provided molecular scientists with a valuable window through which to probe the electronic structure and dynamics of molecules. But the answer to one fundamental quantum question-whether the core hole is localized or delocalized-has remained elusive for diatomic

  14. Gravitational waves found, black-hole models led the way

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Gravitational waves found, black-hole models led the way Gravitational waves found, black-hole models led the way Gravitational waves were predicted by Einstein's theory of general relativity in 1916, and now, almost exactly 100 years later, the faint ripples across space-time have been found. February 11, 2016 A simulation of two merging black holes, creating gravitational waves. Photo courtesy of LIGO. A simulation of two merging black holes, creating gravitational waves. Photo courtesy of

  15. Trumpet-puncture initial data for black holes

    SciTech Connect (OSTI)

    Immerman, Jason D.; Baumgarte, Thomas W.

    2009-09-15

    We propose a new approach, based on the puncture method, to construct black hole initial data in the so-called trumpet geometry, i.e. on slices that asymptote to a limiting surface of nonzero areal radius. Our approach is easy to implement numerically and, at least for nonspinning black holes, does not require any internal boundary conditions. We present numerical results, obtained with a uniform-grid finite-difference code, for boosted black holes and binary black holes. We also comment on generalizations of this method for spinning black holes.

  16. Astrophysical black holes in screened modified gravity

    SciTech Connect (OSTI)

    Davis, Anne-Christine; Jha, Rahul; Muir, Jessica; Gregory, Ruth E-mail: r.a.w.gregory@durham.ac.uk E-mail: jlmuir@umich.edu

    2014-08-01

    Chameleon, environmentally dependent dilaton, and symmetron gravity are three models of modified gravity in which the effects of the additional scalar degree of freedom are screened in dense environments. They have been extensively studied in laboratory, cosmological, and astrophysical contexts. In this paper, we present a preliminary investigation into whether additional constraints can be provided by studying these scalar fields around black holes. By looking at the properties of a static, spherically symmetric black hole, we find that the presence of a non-uniform matter distribution induces a non-constant scalar profile in chameleon and dilaton, but not necessarily symmetron gravity. An order of magnitude estimate shows that the effects of these profiles on in-falling test particles will be sub-leading compared to gravitational waves and hence observationally challenging to detect.

  17. Slant hole completion test. Final report

    SciTech Connect (OSTI)

    Mann, R.L.

    1993-07-01

    One of the Department of Energy`s (DOE) Strategies and Objectives in the Natural Gas Program is to conduct activities to transfer technology from R&D programs to potential users. The Slant Hole Completion Test has achieved exactly this objective. The Slant Hole site is essentially the same as the Multiwell site and is located in the southeastern portion of the Piceance Basin near Rifle, Colorado. The Piceance Basin is typical of the Western low permeability basins that contain thick sequences of sands, silts and coals deposited during the Cretaceous period. These sequences contain vast amounts of natural gas but have proven to be resistant to commercial production because of the low permeability of the host rocks. Using the knowledge gained from the DOE`s earlier Multiwell experiment, the SHCT-1 was drilled to demonstrate that by intersecting the natural fractures found in these ``tight rocks,`` commercial gas production can be obtained.

  18. Method and apparatus of assessing down-hole drilling conditions

    DOE Patents [OSTI]

    Hall, David R. (Provo, UT); Pixton, David S. (Lehl, UT); Johnson, Monte L. (Orem, UT); Bartholomew, David B. (Springville, UT); Fox, Joe (Spanish Fork, UT)

    2007-04-24

    A method and apparatus for use in assessing down-hole drilling conditions are disclosed. The apparatus includes a drill string, a plurality of sensors, a computing device, and a down-hole network. The sensors are distributed along the length of the drill string and are capable of sensing localized down-hole conditions while drilling. The computing device is coupled to at least one sensor of the plurality of sensors. The data is transmitted from the sensors to the computing device over the down-hole network. The computing device analyzes data output by the sensors and representative of the sensed localized conditions to assess the down-hole drilling conditions. The method includes sensing localized drilling conditions at a plurality of points distributed along the length of a drill string during drilling operations; transmitting data representative of the sensed localized conditions to a predetermined location; and analyzing the transmitted data to assess the down-hole drilling conditions.

  19. Articles which include chevron film cooling holes, and related processes

    DOE Patents [OSTI]

    Bunker, Ronald Scott; Lacy, Benjamin Paul

    2014-12-09

    An article is described, including an inner surface which can be exposed to a first fluid; an inlet; and an outer surface spaced from the inner surface, which can be exposed to a hotter second fluid. The article further includes at least one row or other pattern of passage holes. Each passage hole includes an inlet bore extending through the substrate from the inlet at the inner surface to a passage hole-exit proximate to the outer surface, with the inlet bore terminating in a chevron outlet adjacent the hole-exit. The chevron outlet includes a pair of wing troughs having a common surface region between them. The common surface region includes a valley which is adjacent the hole-exit; and a plateau adjacent the valley. The article can be an airfoil. Related methods for preparing the passage holes are also described.

  20. Down-hole periodic seismic generator

    DOE Patents [OSTI]

    Hardee, H.C.; Hills, R.G.; Striker, R.P.

    1982-10-28

    A down hole periodic seismic generator system is disclosed for transmitting variable frequency, predominantly shear-wave vibration into earth strata surrounding a borehole. The system comprises a unitary housing operably connected to a well head by support and electrical cabling and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a variable speed pneumatic oscillator and a self-contained pneumatic reservoir for producing a frequency-swept seismic output over a discrete frequency range.

  1. Probing Core-Hole Localization in Molecular Nitrogen

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Probing Core-Hole Localization in Molecular Nitrogen Print The behavior of the core hole created in molecular x-ray photoemission experiments has provided molecular scientists with a valuable window through which to probe the electronic structure and dynamics of molecules. But the answer to one fundamental quantum question-whether the core hole is localized or delocalized-has remained elusive for diatomic molecules in which both atoms are the same element. An international team of scientists

  2. Probing Core-Hole Localization in Molecular Nitrogen

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Probing Core-Hole Localization in Molecular Nitrogen Print The behavior of the core hole created in molecular x-ray photoemission experiments has provided molecular scientists with a valuable window through which to probe the electronic structure and dynamics of molecules. But the answer to one fundamental quantum question-whether the core hole is localized or delocalized-has remained elusive for diatomic molecules in which both atoms are the same element. An international team of scientists

  3. Probing Core-Hole Localization in Molecular Nitrogen

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Probing Core-Hole Localization in Molecular Nitrogen Print The behavior of the core hole created in molecular x-ray photoemission experiments has provided molecular scientists with a valuable window through which to probe the electronic structure and dynamics of molecules. But the answer to one fundamental quantum question-whether the core hole is localized or delocalized-has remained elusive for diatomic molecules in which both atoms are the same element. An international team of scientists

  4. Optoelectronic device with nanoparticle embedded hole injection/transport layer

    DOE Patents [OSTI]

    Wang, Qingwu (Chelmsford, MA); Li, Wenguang (Andover, MA); Jiang, Hua (Methuen, MA)

    2012-01-03

    An optoelectronic device is disclosed that can function as an emitter of optical radiation, such as a light-emitting diode (LED), or as a photovoltaic (PV) device that can be used to convert optical radiation into electrical current, such as a photovoltaic solar cell. The optoelectronic device comprises an anode, a hole injection/transport layer, an active layer, and a cathode, where the hole injection/transport layer includes transparent conductive nanoparticles in a hole transport material.

  5. Ultrafast Core-Hole Induced Dynamics in Water

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ultrafast Core-Hole Induced Dynamics in Water Ultrafast Core-Hole Induced Dynamics in Water Print Wednesday, 22 February 2006 00:00 A thorough understanding of the chemical processes that are initiated when radiation interacts with aqueous systems is essential for many diverse fields, from condensed matter physics to medicine to environmental science. An incoming photon with enough energy to produce a core hole in a water molecule sets off motions that can affect bonding configurations, which in

  6. Probing Core-Hole Localization in Molecular Nitrogen

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Probing Core-Hole Localization in Molecular Nitrogen Print The behavior of the core hole created in molecular x-ray photoemission experiments has provided molecular scientists with a valuable window through which to probe the electronic structure and dynamics of molecules. But the answer to one fundamental quantum question-whether the core hole is localized or delocalized-has remained elusive for diatomic molecules in which both atoms are the same element. An international team of scientists

  7. Core Holes At Steamboat Springs Area (Warpinski, Et Al., 2004...

    Open Energy Info (EERE)

    2004) Exploration Activity Details Location Steamboat Springs Area Exploration Technique Core Holes Activity Date Usefulness not indicated DOE-funding Unknown Notes Update to...

  8. Core Holes At Long Valley Caldera Geothermal Area (Benoit, 1984...

    Open Energy Info (EERE)

    Exploration Basis Several core holes were also drilled in the caldera's west moat by Phillips Petroleum Company in 1982, including: PLV-1, drilled to approximately 711 m depth...

  9. Thermal Gradient Holes At Kilauea Summit Area (Keller, Et Al...

    Open Energy Info (EERE)

    L. Trowbridge Grose, John C. Murray, Catherine K. Skokan (1979) Results Of An Experimental Drill Hole At The Summit Of Kilauea Volcano, Hawaii Additional References Retrieved...

  10. Temperature, heat flow maps and temperature gradient holes |...

    Open Energy Info (EERE)

    to library Report: Temperature, heat flow maps and temperature gradient holes Author T. G. Zacharakis Organization Colorado Geological Survey in Cooperation with the U.S....

  11. Slim Holes At Reese River Area (Henkle & Ronne, 2008) | Open...

    Open Energy Info (EERE)

    Technique Slim Holes Activity Date Usefulness useful DOE-funding Unknown Notes Well RR 56-4, was not successful in intersecting an exploitable geothermal resource. However, the...

  12. Thermal Gradient Holes At Chocolate Mountains Area (Alm, Et Al...

    Open Energy Info (EERE)

    Thermal Gradient Holes Activity Date Usefulness useful DOE-funding Unknown Notes "Shallow temperature gradient drilling began at the CMAGR in January of 2010. 13 temperature...

  13. Thermal Gradient Holes At Long Valley Caldera Geothermal Area...

    Open Energy Info (EERE)

    Long Valley Caldera Geothermal Area (Conservation, 2009) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Long Valley...

  14. Core Holes At Valles Caldera - Sulphur Springs Geothermal Area...

    Open Energy Info (EERE)

    Goff, Et Al., 1987) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Core Holes At Valles Caldera - Sulphur Springs Geothermal Area (Goff, Et Al.,...

  15. Thermal Gradient Holes At North Brawley Geothermal Area (Edmunds...

    Open Energy Info (EERE)

    Edmunds & W., 1977) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At North Brawley Geothermal Area (Edmunds & W., 1977)...

  16. Core Holes At Blue Mountain Geothermal Area (Fairbank & Niggemann...

    Open Energy Info (EERE)

    Activity Details Location Blue Mountain Geothermal Area Exploration Technique Core Holes Activity Date 2002 - 2004 Usefulness useful DOE-funding Unknown Exploration Basis Cores...

  17. Slim Holes At Blue Mountain Area (Warpinski, Et Al., 2002) |...

    Open Energy Info (EERE)

    navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At Blue Mountain Area (Warpinski, Et Al., 2002) Exploration Activity Details Location Blue...

  18. Thermal Gradient Holes At Blue Mountain Geothermal Area (Fairbank...

    Open Energy Info (EERE)

    Exploration Basis Thermal gradient holes were drilled in an effort to determine the feasibility of commercial geothermal energy generation at Blue Mountain Notes Ten temperature...

  19. Thermal Gradient Holes At Pilgrim Hot Springs Area (DOE GTP)...

    Open Energy Info (EERE)

    Pilgrim Hot Springs Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Pilgrim Hot Springs Area (DOE GTP)...

  20. Two Electron Holes in Hematite Facilitate Water Splitting

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Two Electron Holes in Hematite Facilitate Water Splitting Print Hydrogen is an attractive form of fuel because its only by-product is nonpolluting water vapor. The problem,...

  1. Thermal Gradient Holes At San Emidio Desert Area (DOE GTP) |...

    Open Energy Info (EERE)

    San Emidio Desert Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At San Emidio Desert Area (DOE GTP)...

  2. Thermal Gradient Holes At Tungsten Mountain Area (Shevenell,...

    Open Energy Info (EERE)

    Holes Activity Date Usefulness useful DOE-funding Unknown Notes Collaboration with the gold mining industry has brought two new geothermal discoveries to the attention of the...

  3. Thermal Gradient Holes At Spencer Hot Springs Area (Shevenell...

    Open Energy Info (EERE)

    Holes Activity Date Usefulness useful DOE-funding Unknown Notes Collaboration with the gold mining industry has brought two new geothermal discoveries to the attention of the...

  4. Slim Holes At Alum Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    Alum Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At Alum Area (DOE GTP) Exploration Activity Details Location Alum...

  5. Slim Holes At Maui Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    Maui Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At Maui Area (DOE GTP) Exploration Activity Details Location Maui...

  6. Thermal Gradient Holes At Newberry Caldera Area (DOE GTP) | Open...

    Open Energy Info (EERE)

    Newberry Caldera Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Newberry Caldera Area (DOE GTP)...

  7. Thermal Gradient Holes At Flint Geothermal Area (DOE GTP) | Open...

    Open Energy Info (EERE)

    Flint Geothermal Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Flint Geothermal Area (DOE GTP)...

  8. Holes Are a Positive Thing: Designing Conductors for Solar Photovoltai...

    Office of Science (SC) Website

    Holes Are a Positive Thing: Designing Conductors for Solar Photovoltaics Basic Energy Sciences (BES) BES Home About Research Facilities Science Highlights Benefits of BES Funding ...

  9. Thermal Gradient Holes At Mcgee Mountain Area (DOE GTP) | Open...

    Open Energy Info (EERE)

    Mcgee Mountain Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Mcgee Mountain Area (DOE GTP) Exploration...

  10. Thermal Gradient Holes At Hawthorne Area (Lazaro, Et Al., 2010...

    Open Energy Info (EERE)

    Unknown Notes The Navy recently completed a temperature gradient hole (TGH) drilling campaign. Results suggest multiple resources may exist on HAD lands. To further define the...

  11. Thermal Gradient Holes At Mccoy Geothermal Area (DOE GTP) | Open...

    Open Energy Info (EERE)

    Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Mccoy Geothermal Area (DOE GTP) Exploration Activity Details...

  12. Thermal Gradient Holes At Hot Springs Ranch Area (Szybinski,...

    Open Energy Info (EERE)

    Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Hot Springs Ranch Area (Szybinski, 2006) Exploration Activity...

  13. Thermal Gradient Holes At Lightning Dock Area (Warpinski, Et...

    Open Energy Info (EERE)

    Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Lightning Dock Area (Warpinski, Et Al., 2004) Exploration Activity...

  14. Thermal Gradient Holes At Kilauea East Rift Geothermal Area ...

    Open Energy Info (EERE)

    Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Kilauea East Rift Geothermal Area (Thomas, 1986) Exploration...

  15. Thermal Gradient Holes At Mt Princeton Hot Springs Geothermal...

    Open Energy Info (EERE)

    Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Mt Princeton Hot Springs Geothermal Area (Held & Henderson, 2012)...

  16. Thermal Gradient Holes At Glass Mountain Area (Cumming And Mackie...

    Open Energy Info (EERE)

    Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Glass Mountain Area (Cumming And Mackie, 2007) Exploration Activity...

  17. Thermal Gradient Holes At Crump's Hot Springs Area (DOE GTP)...

    Open Energy Info (EERE)

    Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Crump's Hot Springs Area (DOE GTP) Exploration Activity Details...

  18. Thermal Gradient Holes At Cove Fort Area - Vapor (Warpinski,...

    Open Energy Info (EERE)

    Gradient Holes Activity Date Usefulness not indicated DOE-funding Unknown Notes Update to Warpinski, et al., 2002 References N. R. Warpinski, A. R. Sattler, R. Fortuna, D....

  19. Thermal Gradient Holes At Cove Fort Area (Warpinski, Et Al.,...

    Open Energy Info (EERE)

    Gradient Holes Activity Date Usefulness not indicated DOE-funding Unknown Notes Update to Warpinski, et al., 2002 References N. R. Warpinski, A. R. Sattler, R. Fortuna, D....

  20. Slim Holes At Steamboat Springs Area (Warpinski, Et Al., 2004...

    Open Energy Info (EERE)

    Technique Slim Holes Activity Date Usefulness useful DOE-funding Unknown Notes Update to Warpinski, et al., 2002 References N. R. Warpinski, A. R. Sattler, R. Fortuna, D....

  1. Thermal Gradient Holes At Breitenbush Hot Springs Area (Ingebritsen...

    Open Energy Info (EERE)

    (1993) Heat Flow From Four New Research Drill Holes In The Western Cascades, Oregon, Usa Additional References Retrieved from "http:en.openei.orgwindex.php?titleThermalGr...

  2. Slim Holes At International Geothermal Area, Japan (Combs, Et...

    Open Energy Info (EERE)

    International Geothermal Area, Japan (Combs, Et Al., 1999) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At International Geothermal...

  3. Raft River Geothermal Exploratory Hole No. 1 (RRGE-1). Completion...

    Open Energy Info (EERE)

    report Jump to: navigation, search OpenEI Reference LibraryAdd to library Report: Raft River Geothermal Exploratory Hole No. 1 (RRGE-1). Completion report Abstract GEOTHERMAL...

  4. Hole-thru-laminate mounting supports for photovoltaic modules

    SciTech Connect (OSTI)

    Wexler, Jason; Botkin, Jonathan; Culligan, Matthew; Detrick, Adam

    2015-02-17

    A mounting support for a photovoltaic module is described. The mounting support includes a pedestal having a surface adaptable to receive a flat side of a photovoltaic module laminate. A hole is disposed in the pedestal, the hole adaptable to receive a bolt or a pin used to couple the pedestal to the flat side of the photovoltaic module laminate.

  5. Charged black holes in generalized teleparallel gravity

    SciTech Connect (OSTI)

    Rodrigues, M.E.; Houndjo, M.J.S.; Tossa, J.; Momeni, D.; Myrzakulov, R. E-mail: sthoundjo@yahoo.fr E-mail: d.momeni@yahoo.com

    2013-11-01

    In this paper we investigate charged static black holes in 4D for generalized teleparallel models of gravity, based on torsion as the geometric object for describing gravity according to the equivalence principle. As a motivated idea, we introduce a set of non-diagonal tetrads and derive the full system of non linear differential equations. We prove that the common Schwarzschild gauge is applicable only when we study linear f(T) case. We reobtain the Reissner-Nordstrom-de Sitter (or RN-AdS) solution for the linear case of f(T) and perform a parametric cosmological reconstruction for two nonlinear models. We also study in detail a type of the no-go theorem in the framework of this modified teleparallel gravity.

  6. Interface-induced heavy-hole/light-hole splitting of acceptors in silicon

    SciTech Connect (OSTI)

    Mol, J. A.; Salfi, J.; Simmons, M. Y.; Rogge, S.; Rahman, R.; Hsueh, Y.; Klimeck, G.; Miwa, J. A.

    2015-05-18

    The energy spectrum of spin-orbit coupled states of individual sub-surface boron acceptor dopants in silicon have been investigated using scanning tunneling spectroscopy at cryogenic temperatures. The spatially resolved tunnel spectra show two resonances, which we ascribe to the heavy- and light-hole Kramers doublets. This type of broken degeneracy has recently been argued to be advantageous for the lifetime of acceptor-based qubits [R. Ruskov and C. Tahan, Phys. Rev. B 88, 064308 (2013)]. The depth dependent energy splitting between the heavy- and light-hole Kramers doublets is consistent with tight binding calculations, and is in excess of 1?meV for all acceptors within the experimentally accessible depth range (<2?nm from the surface). These results will aid the development of tunable acceptor-based qubits in silicon with long coherence times and the possibility for electrical manipulation.

  7. Thermal Gradient Holes At Twenty-Nine Palms Area (Page, Et Al...

    Open Energy Info (EERE)

    gradient holes for the GPO. Samples taken from each hole were similar in nature; mixtures of sand and conglomerates with the occasional granite sections were...

  8. Fuel injector Holes (Fabrication of Micro-Orifices for Fuel Injectors...

    Office of Environmental Management (EM)

    injector Holes (Fabrication of Micro-Orifices for Fuel Injectors) Fuel injector Holes (Fabrication of Micro-Orifices for Fuel Injectors) 2009 DOE Hydrogen Program and Vehicle...

  9. Rock Sampling At Seven Mile Hole Area (Larson, Et Al., 2009)...

    Open Energy Info (EERE)

    Seven Mile Hole Area (Larson, Et Al., 2009) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Rock Sampling At Seven Mile Hole Area (Larson, Et...

  10. Isotopic Analysis At Seven Mile Hole Area (Larson, Et Al., 2009...

    Open Energy Info (EERE)

    Seven Mile Hole Area (Larson, Et Al., 2009) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Isotopic Analysis At Seven Mile Hole Area (Larson, Et...

  11. Field Mapping At Seven Mile Hole Area (Larson, Et Al., 2009)...

    Open Energy Info (EERE)

    Seven Mile Hole Area (Larson, Et Al., 2009) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Field Mapping At Seven Mile Hole Area (Larson, Et...

  12. Varying fine structure 'constant' and charged black holes

    SciTech Connect (OSTI)

    Bekenstein, Jacob D.; Schiffer, Marcelo

    2009-12-15

    Speculation that the fine-structure constant {alpha} varies in spacetime has a long history. We derive, in 4-D general relativity and in isotropic coordinates, the solution for a charged spherical black hole according to the framework for dynamical {alpha} J. D. Bekenstein, Phys. Rev. D 25, 1527 (1982).. This solution coincides with a previously known one-parameter extension of the dilatonic black hole family. Among the notable properties of varying-{alpha} charged black holes are adherence to a 'no hair' principle, the absence of the inner (Cauchy) horizon of the Reissner-Nordstroem black holes, the nonexistence of precisely extremal black holes, and the appearance of naked singularities in an analytic extension of the relevant metric. The exteriors of almost extremal electrically (magnetically) charged black holes have simple structures which makes their influence on applied magnetic (electric) fields transparent. We rederive the thermodynamic functions of the modified black holes; the otherwise difficult calculation of the electric potential is done by a shortcut. We confirm that variability of {alpha} in the wake of expansion of the universe does not threaten the generalized second law.

  13. TEST-HOLE CONSTRUCTION FOR A NEUTRONIC REACTOR

    DOE Patents [OSTI]

    Ohlinger, L.A.; Seitz, F.; Young, G.J.

    1959-02-17

    Test-hole construction is described for a reactor which provides safe and ready access to the neutron flux region for specimen materials which are to be irradiated therein. An elongated tubular thimble adapted to be inserted in the access hole through the wall of the reactor is constructed of aluminum and is provided with a plurality of holes parallel to the axis of the thimble for conveying the test specimens into position for irradiation, and a conduit for the circulation of coolant. A laminated shield formed of alternate layers of steel and pressed wood fiber is disposed lengthwise of the thimble near the outer end thereof.

  14. Back reaction on a Reissner-Nordstro''m black hole

    SciTech Connect (OSTI)

    Wang, Bobo; Huang, Chao-guang

    2001-06-15

    The perturbed (''dressed'') metric of the conformally invariant scalar field in a Reissner-Nordstroem (RN) black hole is given by solving the semiclassical Einstein and Maxwell equations according to York's back-reaction approach. Some properties of the ''dressed'' black hole are obtained, such as its ''dressed'' mass, the location of the event horizon, and its surface gravity. It will also be found that the hypersurfaces of r{sub +} and r{sub {minus}} which are the event and Cauchy horizons in the ''naked'' RN black hole, become spacelike in the perturbed geometry.

  15. Hole Localization in Molecular Crystals from Hybrid Density Functional Theory

    SciTech Connect (OSTI)

    Sai, Na; Barbara, Paul F.; Leung, Kevin

    2011-06-02

    We use first-principles computational methods to examine hole trapping in organic molecular crystals. We present a computational scheme based on the tuning of the fraction of exact exchange in hybrid density functional theory to eliminate the many-electron self-interaction error. With small organic molecules, we show that this scheme gives accurate descriptions of ionization and dimer dissociation. We demonstrate that the excess hole in perfect molecular crystals forms self-trapped molecular polarons. The predicted absolute ionization potentials of both localized and delocalized holes are consistent with experimental values.

  16. DOE - NNSA/NFO -- News & Views Big Hole Drilling

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Underground Testing Perfected Big-Hole Drilling Technology Photo - Rowan Drilling Company's On July 26, 1957, a safety experiment called "Pascal A" was detonated in an unstemmed hole. Although the test was not spectacular, it does hold the distinction of being the first nuclear test in the world to be detonated underground. From 1957 to 1992, 533 contained tests and nine unstemmed tests were conducted at the Nevada Test Site (NTS). If the depths of all the 36-inch diameter holes

  17. DOE - NNSA/NFO -- Photo Library Big Hole Drilling

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Big Hole Drilling NNSA/NFO Language Options U.S. DOE/NNSA - Nevada Field Office Photo Library - Big Hole Drilling The need to drill large-diameter holes at the Nevada National Security Site resulted from the Limited Test Ban Treaty (LTBT), signed by President John F. Kennedy in Moscow on August 5, 1963. The LTBT prohibited testing nuclear weapons in the atmosphere, underwater and in outer space. As a result, scientists from the U.S. Department of Energy weapons laboratories had to relocate all

  18. Thermodynamics of Sultana-Dyer black hole

    SciTech Connect (OSTI)

    Majhi, Bibhas Ranjan

    2014-05-01

    The thermodynamical entities on the dynamical horizon are not naturally defined like the usual static cases. Here I find the temperature, Smarr formula and the first law of thermodynamics for the Sultana-Dyer metric which is related to the Schwarzschild spacetime by a time dependent conformal factor. To find the temperature (T), the chiral anomaly expressions for the two dimensional spacetime are used. This shows an application of the anomaly method to study Hawking effect for a dynamical situation. Moreover, the analysis singles out one expression for temperature among two existing expressions in the literature. Interestingly, the present form satisfies the first law of thermodynamics. Also, it relates the Misner-Sharp energy (Ē) and the horizon entropy ( S-bar ) by an algebraic expression Ē = 2 S-bar T which is the general form of the Smarr formula. This fact is similar to the usual static black hole cases in Einstein's gravity where the energy is identified as the Komar conserved quantity.

  19. Bubbling supertubes and foaming black holes

    SciTech Connect (OSTI)

    Bena, Iosif; Warner, Nicholas P.

    2006-09-15

    We construct smooth BPS three-charge geometries that resolve the zero-entropy singularity of the U(1)xU(1) invariant black ring. This singularity is resolved by a geometric transition that results in geometries without any branes sources or singularities but with nontrivial topology. These geometries are both ground states of the black ring, and nontrivial microstates of the D1-D5-P system. We also find the form of the geometries that result from the geometric transition of N zero-entropy black rings, and argue that, in general, such geometries give a very large number of smooth bound-state three-charge solutions, parametrized by 6N functions. The generic microstate solution is specified by a four-dimensional hyper-Kaehler geometry of a certain signature, and contains a 'foam' of nontrivial two-spheres. We conjecture that these geometries will account for a significant part of the entropy of the D1-D5-P black hole, and that Mathur's conjecture might reduce to counting certain hyper-Kaehler manifolds.

  20. Fast radial flows in transition disk holes

    SciTech Connect (OSTI)

    Rosenfeld, Katherine A.; Andrews, Sean M.; Chiang, Eugene

    2014-02-20

    Protoplanetary 'transition' disks have large, mass-depleted central cavities, yet also deliver gas onto their host stars at rates comparable to disks without holes. The paradox of simultaneous transparency and accretion can be explained if gas flows inward at much higher radial speeds inside the cavity than outside the cavity, since surface density (and by extension optical depth) varies inversely with inflow velocity at fixed accretion rate. Radial speeds within the cavity might even have to approach free-fall values to explain the huge surface density contrasts inferred for transition disks. We identify observational diagnostics of fast radial inflow in channel maps made in optically thick spectral lines. Signatures include (1) twisted isophotes in maps made at low systemic velocities and (2) rotation of structures observed between maps made in high-velocity line wings. As a test case, we apply our new diagnostic tools to archival Atacama Large Millimeter Array data on the transition disk HD 142527 and uncover evidence for free-fall radial velocities inside its cavity. Although the observed kinematics are also consistent with a disk warp, the radial inflow scenario is preferred because it predicts low surface densities that appear consistent with recent observations of optically thin CO isotopologues in this disk. How material in the disk cavity sheds its angular momentum wholesale to fall freely onto the star is an unsolved problem; gravitational torques exerted by giant planets or brown dwarfs are briefly discussed as a candidate mechanism.

  1. Slim Holes At Steamboat Springs Area (Warpinski, Et Al., 2002...

    Open Energy Info (EERE)

    slim hole 12-33, was drilled to a total depth of 297 m during April 2001. Continuous core was taken from 152 m to total depth. Numerous open fractures were also observed in...

  2. Slant-hole collimator, dual mode sterotactic localization method

    DOE Patents [OSTI]

    Weisenberger, Andrew G. (Grafton, VA)

    2002-01-01

    The use of a slant-hole collimator in the gamma camera of dual mode stereotactic localization apparatus allows the acquisition of a stereo pair of scintimammographic images without repositioning of the gamma camera between image acquisitions.

  3. Core Lithology State of Hawaii Scientific Observation Hole 4...

    Open Energy Info (EERE)

    Abstract Summary lithological log for SOH-4 test hole Authors Frank A. Trusdell, Elizabeth A. Novak and Rene' S. Evans Published U.S. Dept. of the Interior, U.S. Geological...

  4. Black hole evaporation in a noncommutative charged Vaidya model

    SciTech Connect (OSTI)

    Sharif, M. Javed, W.

    2012-06-15

    We study the black hole evaporation and Hawking radiation for a noncommutative charged Vaidya black hole. For this purpose, we determine a spherically symmetric charged Vaidya model and then formulate a noncommutative Reissner-Nordstroem-like solution of this model, which leads to an exact (t - r)-dependent metric. The behavior of the temporal component of this metric and the corresponding Hawking temperature are investigated. The results are shown in the form of graphs. Further, we examine the tunneling process of charged massive particles through the quantum horizon. We find that the tunneling amplitude is modified due to noncommutativity. Also, it turns out that the black hole evaporates completely in the limits of large time and horizon radius. The effect of charge is to reduce the temperature from a maximum value to zero. We note that the final stage of black hole evaporation is a naked singularity.

  5. Core Holes At Valles Caldera - Sulphur Springs Geothermal Area...

    Open Energy Info (EERE)

    Dennis L. Nielson, Pisto Larry, C.W. Criswell, R. Gribble, K. Meeker, J.A. Musgrave, T. Smith, D. Wilson (1989) Scientific Core Hole Valles Caldera No. 2B (VC-2B), New Mexico:...

  6. Temperatures, heat flow, and water chemistry from drill holes...

    Open Energy Info (EERE)

    Temperatures, heat flow, and water chemistry from drill holes in the Raft River geothermal system, Cassia County, Idaho Jump to: navigation, search OpenEI Reference LibraryAdd to...

  7. Raft River Geothermal Exploratory Hole No. 2, RRGE-2. Completion...

    Open Energy Info (EERE)

    report Jump to: navigation, search OpenEI Reference LibraryAdd to library Report: Raft River Geothermal Exploratory Hole No. 2, RRGE-2. Completion report Abstract The Raft...

  8. Two Electron Holes in Hematite Facilitate Water Splitting

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Two Electron Holes in Hematite Facilitate Water Splitting Two Electron Holes in Hematite Facilitate Water Splitting Print Wednesday, 26 September 2012 00:00 Hydrogen is an attractive form of fuel because its only by-product is nonpolluting water vapor. The problem, however, is that the production of hydrogen-via the process of water splitting-currently requires the burning of traditional fossil fuels. Therefore, water splitting by photoelectrochemical cells (PECs) fueled by solar power has long

  9. Ultrafast Core-Hole Induced Dynamics in Water

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ultrafast Core-Hole Induced Dynamics in Water Print A thorough understanding of the chemical processes that are initiated when radiation interacts with aqueous systems is essential for many diverse fields, from condensed matter physics to medicine to environmental science. An incoming photon with enough energy to produce a core hole in a water molecule sets off motions that can affect bonding configurations, which in turn affect subsequent chemical-reaction pathways. However, it is a fundamental

  10. Ultrafast Core-Hole Induced Dynamics in Water

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ultrafast Core-Hole Induced Dynamics in Water Print A thorough understanding of the chemical processes that are initiated when radiation interacts with aqueous systems is essential for many diverse fields, from condensed matter physics to medicine to environmental science. An incoming photon with enough energy to produce a core hole in a water molecule sets off motions that can affect bonding configurations, which in turn affect subsequent chemical-reaction pathways. However, it is a fundamental

  11. Effective theories and black hole production in warped compactifications

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Effective theories and black hole production in warped compactifications Citation Details In-Document Search Title: Effective theories and black hole production in warped compactifications We investigate aspects of the four-dimensional (4D) effective description of brane world scenarios based on warped compactification on anti-de Sitter space. The low-energy dynamics is described by visible matter gravitationally coupled to a ''dark'' conformal field

  12. Ultrafast Core-Hole Induced Dynamics in Water

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ultrafast Core-Hole Induced Dynamics in Water Print A thorough understanding of the chemical processes that are initiated when radiation interacts with aqueous systems is essential for many diverse fields, from condensed matter physics to medicine to environmental science. An incoming photon with enough energy to produce a core hole in a water molecule sets off motions that can affect bonding configurations, which in turn affect subsequent chemical-reaction pathways. However, it is a fundamental

  13. Ultrafast Core-Hole Induced Dynamics in Water

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ultrafast Core-Hole Induced Dynamics in Water Print A thorough understanding of the chemical processes that are initiated when radiation interacts with aqueous systems is essential for many diverse fields, from condensed matter physics to medicine to environmental science. An incoming photon with enough energy to produce a core hole in a water molecule sets off motions that can affect bonding configurations, which in turn affect subsequent chemical-reaction pathways. However, it is a fundamental

  14. Ultrafast Core-Hole Induced Dynamics in Water

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ultrafast Core-Hole Induced Dynamics in Water Print A thorough understanding of the chemical processes that are initiated when radiation interacts with aqueous systems is essential for many diverse fields, from condensed matter physics to medicine to environmental science. An incoming photon with enough energy to produce a core hole in a water molecule sets off motions that can affect bonding configurations, which in turn affect subsequent chemical-reaction pathways. However, it is a fundamental

  15. Ultrafast Core-Hole Induced Dynamics in Water

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ultrafast Core-Hole Induced Dynamics in Water Print A thorough understanding of the chemical processes that are initiated when radiation interacts with aqueous systems is essential for many diverse fields, from condensed matter physics to medicine to environmental science. An incoming photon with enough energy to produce a core hole in a water molecule sets off motions that can affect bonding configurations, which in turn affect subsequent chemical-reaction pathways. However, it is a fundamental

  16. Low-lying dipole response in the stable {sup 40,48}Ca nuclei within the second random-phase approximation

    SciTech Connect (OSTI)

    Gambacurta, D.; Grasso, M.; Catara, F.

    2012-10-20

    The low-lying dipole strength distributions of {sup 40}CaCa and {sup 48}Ca, in the energy region between 5 and 10 MeV, are studied within the second random phase approximation (RPA) with Skyrme interaction. Standard RPA models do not usually predict any presence of strength in this energy region, while experimentally a significant amount of strength is found. The inclusion of the 2 particle -2 hole configurations allows to obtain a description in a rather good agreement with the experimental data. The properties of the most collective state are analyzed in terms of its 1 particle -1 hole nature and its transition densities.

  17. Microhole Coiled Tubing Bottom Hole Assemblies

    SciTech Connect (OSTI)

    Don Macune

    2008-06-30

    The original objective of the project, to deliver an integrated 3 1/8-inch diameter Measurement While Drilling (MWD) and Logging While Drilling (LWD) system for drilling small boreholes using coiled tubing drilling, has been achieved. Two prototype systems have been assembled and tested in the lab. One of the systems has been successfully tested downhole in a conventional rotary drilling environment. Development of the 3 1/8-inch system has also lead to development and commercialization of a slightly larger 3.5-inch diameter system. We are presently filling customer orders for the 3.5-inch system while continuing with commercialization of the 3 1/8-inch system. The equipment developed by this project will be offered for sale to multiple service providers around the world, enabling the more rapid expansion of both coiled tubing drilling and conventional small diameter drilling. The project was based on the reuse of existing technology whenever possible in order to minimize development costs, time, and risks. The project was begun initially by Ultima Labs, at the time a small company ({approx}12 employees) which had successfully developed a number of products for larger oil well service companies. In September, 2006, approximately 20 months after inception of the project, Ultima Labs was acquired by Sondex plc, a worldwide manufacturer of downhole instrumentation for cased hole and drilling applications. The acquisition provided access to proven technology for mud pulse telemetry, downhole directional and natural gamma ray measurements, and surface data acquisition and processing, as well as a global sales and support network. The acquisition accelerated commercialization through existing Sondex customers. Customer demand resulted in changes to the product specification to support hotter (150 C) and deeper drilling (20,000 psi pressure) than originally proposed. The Sondex acquisition resulted in some project delays as the resistivity collar was interfaced to a different MWD system and also as the mechanical design was revised for the new pressure requirements. However, the Sondex acquisition has resulted in a more robust system, secure funding for completion of the project, and more rapid commercialization.

  18. Organization of growing random networks

    SciTech Connect (OSTI)

    Krapivsky, P. L.; Redner, S.

    2001-06-01

    The organizational development of growing random networks is investigated. These growing networks are built by adding nodes successively, and linking each to an earlier node of degree k with an attachment probability A{sub k}. When A{sub k} grows more slowly than linearly with k, the number of nodes with k links, N{sub k}(t), decays faster than a power law in k, while for A{sub k} growing faster than linearly in k, a single node emerges which connects to nearly all other nodes. When A{sub k} is asymptotically linear, N{sub k}(t){similar_to}tk{sup {minus}{nu}}, with {nu} dependent on details of the attachment probability, but in the range 2{lt}{nu}{lt}{infinity}. The combined age and degree distribution of nodes shows that old nodes typically have a large degree. There is also a significant correlation in the degrees of neighboring nodes, so that nodes of similar degree are more likely to be connected. The size distributions of the in and out components of the network with respect to a given node{emdash}namely, its {open_quotes}descendants{close_quotes} and {open_quotes}ancestors{close_quotes}{emdash}are also determined. The in component exhibits a robust s{sup {minus}2} power-law tail, where s is the component size. The out component has a typical size of order lnt, and it provides basic insights into the genealogy of the network.

  19. Improvement of tap holes at Wakayama No. 5 blast furnace

    SciTech Connect (OSTI)

    Yamashita, M.; Kashiwada, M.; Shibuta, H.

    1995-12-01

    The service life of blast furnaces, as the result of various improvement measures, has been extended from the conventional 5 to 7 years to 15 to 20 years. Wakayama No. 5 blast furnace adopted SiC bricks. Though SiC brick excelled in strength and durability, it has raised problems such as tap hole inside temperature lowering attributable to its high thermal conductivity, insufficient mud burning and gas blow-out. Nevertheless, various countermeasures described within have been taken against such problems, and as the result it has now become possible to maintain tap holes in stable conditions.

  20. Potential Antiferromagnetic Fluctuations in Hole-Doped Iron-Pnictide

    Office of Scientific and Technical Information (OSTI)

    Superconductor Ba1-xKxFe2As2 Studied by 75As Nuclear Magnetic Resonance Measurement0.1143/JPSJ.81.054704 (Journal Article) | SciTech Connect Potential Antiferromagnetic Fluctuations in Hole-Doped Iron-Pnictide Superconductor Ba1-xKxFe2As2 Studied by 75As Nuclear Magnetic Resonance Measurement0.1143/JPSJ.81.054704 Citation Details In-Document Search Title: Potential Antiferromagnetic Fluctuations in Hole-Doped Iron-Pnictide Superconductor Ba1-xKxFe2As2 Studied by 75As Nuclear Magnetic

  1. Hole cleaning imperative in coiled tubing drilling operations

    SciTech Connect (OSTI)

    Rameswar, R.M.; Mudda, K.

    1995-09-01

    Annular flow modeling in coiled tubing applications is essential for optimizing mud rheology and keeping the hole clean. Cuttings transport in coiled tubing drilling must be optimized, particularly the modeling of hole cleaning capabilities. The effects of two different muds in contrasting geometries on hold cleaning efficiency are considered, with the simulation performed using Petrocalc 14. Coiled tubing is widely used to drill new vertical and horizontal wells, and in re-entry operations. Horizontal well problems are subsequently modeled, where annular eccentricities can range anywhere from concentric to highly offset, given the highly buckled or helically deflected states of many drill coils.

  2. Greybody factors for MyersPerry black holes

    SciTech Connect (OSTI)

    Boonserm, Petarpa; Chatrabhuti, Auttakit Ngampitipan, Tritos; Visser, Matt

    2014-11-15

    The MyersPerry black holes are higher-dimensional generalizations of the usual (3+1)-dimensional rotating Kerr black hole. They are of considerable interest in KaluzaKlein models, specifically within the context of brane-world versions thereof. In the present article, we shall consider the greybody factors associated with scalar field excitations of the MyersPerry spacetimes, and develop some rigorous bounds on these greybody factors. These bounds are of relevance for characterizing both the higher-dimensional Hawking radiation, and the super-radiance, that is expected for these spacetimes.

  3. Final Report Limited Soil Investigation of Project Chariot Test Holes

    Office of Legacy Management (LM)

    Limited Soil Investigation of Project Chariot Test Holes Cape Thompson, Alaska December 2010 Prepared for U.S. Department of Energy and U.S. Army Corps of Engineers, Alaska District Post Office Box 6898 Elmendorf AFB, Alaska 99506-6898 Contract W911KB-08-D-0003 Task Order 12, Mod 001 Prepared by Fairbanks Environmental Services 3538 International Street Fairbanks, Alaska 99701 (907) 452-1006 FES Project No. 5012-06 Final Report Limited Soil Investigation of Project Chariot Test Holes, Cape

  4. Low-lying dipole response in the stable {sup 40,48}Ca nuclei with the second random-phase approximation

    SciTech Connect (OSTI)

    Gambacurta, D.; Catara, F.

    2011-09-15

    Low-energy dipole excitations are analyzed for the stable isotopes {sup 40}Ca and {sup 48}Ca in the framework of the Skyrme-second random-phase approximation. The corresponding random-phase approximation calculations provide a negligible strength distribution for both nuclei in the energy region from 5 to 10 MeV. The inclusion and the coupling of 2 particle-2 hole configurations in the second random-phase approximation lead to an appreciable dipole response at low energies for the neutron-rich nucleus {sup 48}Ca. The presence of a neutron skin in the nucleus {sup 48}Ca would suggest the interpretation of the low-lying response in terms of a pygmy excitation. The composition of the excitation modes (content of 1 particle-1 hole and 2 particle-2 hole configurations), their transition densities and their collectivity (number and coherence of the different contributions) are analyzed. This analysis indicates that, in general, these excitations cannot be clearly interpreted in terms of oscillations of the neutron skin against the core with the exception of the peak with the largest B(E1) value, which is located at 9.09 MeV. For this peak the neutron transition density dominates and the neutron and proton transition densities oscillate out of phase in the internal part of the nucleus leading to a strong mixing of isoscalar and isovector components. Therefore, this state shows some features usually associated to pygmy resonances.

  5. Topological black holes in Lovelock-Born-Infeld gravity

    SciTech Connect (OSTI)

    Dehghani, M. H.; Alinejadi, N.; Hendi, S. H.

    2008-05-15

    In this paper, we present topological black holes of third order Lovelock gravity in the presence of cosmological constant and nonlinear electromagnetic Born-Infeld field. Depending on the metric parameters, these solutions may be interpreted as black hole solutions with inner and outer event horizons, an extreme black hole or naked singularity. We investigate the thermodynamics of asymptotically flat solutions and show that the thermodynamic and conserved quantities of these black holes satisfy the first law of thermodynamic. We also endow the Ricci flat solutions with a global rotation and calculate the finite action and conserved quantities of these class of solutions by using the counterterm method. We compute the entropy through the use of the Gibbs-Duhem relation and find that the entropy obeys the area law. We obtain a Smarr-type formula for the mass as a function of the entropy, the angular momenta, and the charge, and compute temperature, angular velocities, and electric potential and show that these thermodynamic quantities coincide with their values which are computed through the use of geometry. Finally, we perform a stability analysis for this class of solutions in both the canonical and the grand-canonical ensemble and show that the presence of a nonlinear electromagnetic field and higher curvature terms has no effect on the stability of the black branes, and they are stable in the whole phase space.

  6. Coiled tubing used for slim hole re-entry

    SciTech Connect (OSTI)

    Traonmilin, E. ); Newman, K. )

    1992-02-17

    A coiled tubing unit with slim hole tools successfully re-entered and cored an existing Elf Aquitaine vertical well in the Paris basin in France. This experiment proved that coiled tubing could be used to drill, core, and test a slim hole well. Elf Aquitaine studied the use of coiled tubing for drilling inexpensive exploration wells in the Paris basin. As a result of this study, Elf believed that coiled tubing exploration drilling could significantly reduce exploration costs. This paper reports on a number of questions raised by this study: Can coiled tubing be used effectively to drill slim open hole How would the drilling rate compare with that of a conventional drilling rig If the rate were too slow, coiled tubing might not be economical. Can a straight vertical well be drilled Coiled tubing pipe has a residual curvature from bending over the reel and gooseneck. Will this curvature make it impossible to drill straight Can the coiled tubing also be used to take cores Once the hole is drilled, can it be tested with coiled tubing

  7. Core Holes At Fort Bliss Area (Combs, Et Al., 1999) | Open Energy...

    Open Energy Info (EERE)

    hole, 4" diameter core) string. The lower percentage for the BSF string was primarily a fi,mctionof large voids encountered in the upper part of the hole, where the rock was more...

  8. Surface geometry of a rotating black hole in a magnetic field...

    Office of Scientific and Technical Information (OSTI)

    Surface geometry of a rotating black hole in a magnetic field Citation Details In-Document Search Title: Surface geometry of a rotating black hole in a magnetic field We study the ...

  9. 16 TAC, part 1, chapter 3, rule 3.100 Seismic Holes and Core...

    Open Energy Info (EERE)

    LibraryAdd to library Legal Document- RegulationRegulation: 16 TAC, part 1, chapter 3, rule 3.100 Seismic Holes and Core HolesLegal Abstract These rules outline definitions...

  10. Geology of Geothermal Test Hole GT-2 Fenton Hill Site, July 1974...

    Open Energy Info (EERE)

    Geothermal Test Hole GT-2 Fenton Hill Site, July 1974 Jump to: navigation, search OpenEI Reference LibraryAdd to library Report: Geology of Geothermal Test Hole GT-2 Fenton Hill...

  11. Entanglement entropy of two black holes and entanglement entropic force

    SciTech Connect (OSTI)

    Shiba, Noburo

    2011-03-15

    We study the entanglement entropy S{sub C} of the massless free scalar field on the outside region C of two black holes A and B whose radii are R{sub 1} and R{sub 2} and how it depends on the distance r(>>R{sub 1},R{sub 2}) between two black holes. If we can consider the entanglement entropy as thermodynamic entropy, we can see the entropic force acting on the two black holes from the r dependence of S{sub C}. We develop the computational method based on that of Bombelli et al. to obtain the r dependence of S{sub C} of scalar fields whose Lagrangian is quadratic with respect to the scalar fields. First, we study S{sub C} in (d+1)-dimensional Minkowski spacetime. In this case the state of the massless free scalar field is the Minkowski vacuum state, and we replace two black holes by two imaginary spheres and take the trace over the degrees of freedom residing in the imaginary spheres. We obtain the leading term of S{sub C} with respect to 1/r. The result is S{sub C}=S{sub A}+S{sub B}+(1/r{sup 2d-2})G(R{sub 1},R{sub 2}), where S{sub A} and S{sub B} are the entanglement entropy on the inside region of A and B, respectively, and G(R{sub 1},R{sub 2}){<=}0. We do not calculate G(R{sub 1},R{sub 2}) in detail, but we show how to calculate it. In the black hole case we use the method used in the Minkowski spacetime case with some modifications. We show that S{sub C} can be expected to be the same form as that in the Minkowski spacetime case. But in the black hole case, S{sub A} and S{sub B} depend on r, so we do not fully obtain the r dependence of S{sub C}. Finally, we assume that the entanglement entropy can be regarded as thermodynamic entropy and consider the entropic force acting on two black holes. We argue how to separate the entanglement entropic force from other forces and how to cancel S{sub A} and S{sub B} whose r dependences are not obtained. Then we obtain the physical prediction, which can be tested experimentally in principle.

  12. Dr. Charles (Chuck) Peden | U.S. DOE Office of Science (SC)

    Office of Science (SC) Website

    of several new catalytic technologies that are viable candidates for exhaust emission control from future fuel-efficient vehicles. Dr. Peden is the author of over 250 papers in...

  13. Dr. Chuck Ross gives final lecture of JLab Spring Science Series...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the Civil War. By David Macaulay, Daily Press March 28, 2008 NEWPORT NEWS - It won't be music to the ears of traditionalists, but Civil War Confederate Gen. Robert E. Lee might...

  14. 1,"Chuck Lenzie Generating Station","Natural gas","Nevada Power...

    U.S. Energy Information Administration (EIA) Indexed Site

    Co",522 9,"Apex Generating Station","Natural gas","Los Angeles Department of Water & Power",494.4 10,"Desert Star Energy Center","Natural gas","Desert Star Energy Center SDG&E",45

  15. Process and structures for fabrication of solar cells with laser ablation steps to form contact holes

    DOE Patents [OSTI]

    Harley, Gabriel; Smith, David D; Dennis, Tim; Waldhauer, Ann; Kim, Taeseok; Cousins, Peter John

    2013-11-19

    Contact holes of solar cells are formed by laser ablation to accomodate various solar cell designs. Use of a laser to form the contact holes is facilitated by replacing films formed on the diffusion regions with a film that has substantially uniform thickness. Contact holes may be formed to deep diffusion regions to increase the laser ablation process margins. The laser configuration may be tailored to form contact holes through dielectric films of varying thickness.

  16. SEARCH FOR SUPERMASSIVE BLACK HOLE BINARIES IN THE SLOAN DIGITAL SKY SURVEY

    Office of Scientific and Technical Information (OSTI)

    SPECTROSCOPIC SAMPLE (Journal Article) | SciTech Connect SEARCH FOR SUPERMASSIVE BLACK HOLE BINARIES IN THE SLOAN DIGITAL SKY SURVEY SPECTROSCOPIC SAMPLE Citation Details In-Document Search Title: SEARCH FOR SUPERMASSIVE BLACK HOLE BINARIES IN THE SLOAN DIGITAL SKY SURVEY SPECTROSCOPIC SAMPLE Supermassive black hole (SMBH) binaries are expected in a ΛCDM cosmology given that most (if not all) massive galaxies contain a massive black hole (BH) at their center. So far, however, direct

  17. Fuel injector Holes (Fabrication of Micro-Orifices for Fuel Injectors) |

    Office of Environmental Management (EM)

    Department of Energy injector Holes (Fabrication of Micro-Orifices for Fuel Injectors) Fuel injector Holes (Fabrication of Micro-Orifices for Fuel Injectors) 2009 DOE Hydrogen Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting, May 18-22, 2009 -- Washington D.C. PDF icon pm_03_fenske.pdf More Documents & Publications Fuel Injector Holes Fuel Injector Holes

  18. Fast generation of sparse random kernel graphs

    SciTech Connect (OSTI)

    Hagberg, Aric; Lemons, Nathan; Du, Wen -Bo

    2015-09-10

    The development of kernel-based inhomogeneous random graphs has provided models that are flexible enough to capture many observed characteristics of real networks, and that are also mathematically tractable. We specify a class of inhomogeneous random graph models, called random kernel graphs, that produces sparse graphs with tunable graph properties, and we develop an efficient generation algorithm to sample random instances from this model. As real-world networks are usually large, it is essential that the run-time of generation algorithms scales better than quadratically in the number of vertices n. We show that for many practical kernels our algorithm runs in time at most ο(n(logn)²). As an example, we show how to generate samples of power-law degree distribution graphs with tunable assortativity.

  19. Bayati Kim Saberi random graph sampler

    Energy Science and Technology Software Center (OSTI)

    2012-06-05

    This software package implements the algorithm from a paper by Bayati, Kim, and Saberi (first reference below) to generate a uniformly random sample of a graph with a prescribed degree distribution.

  20. Fast generation of sparse random kernel graphs

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hagberg, Aric; Lemons, Nathan; Du, Wen -Bo

    2015-09-10

    The development of kernel-based inhomogeneous random graphs has provided models that are flexible enough to capture many observed characteristics of real networks, and that are also mathematically tractable. We specify a class of inhomogeneous random graph models, called random kernel graphs, that produces sparse graphs with tunable graph properties, and we develop an efficient generation algorithm to sample random instances from this model. As real-world networks are usually large, it is essential that the run-time of generation algorithms scales better than quadratically in the number of vertices n. We show that for many practical kernels our algorithm runs in timemore » at most ο(n(logn)²). As an example, we show how to generate samples of power-law degree distribution graphs with tunable assortativity.« less

  1. Instability of black hole formation in gravitational collapse

    SciTech Connect (OSTI)

    Joshi, Pankaj S.; Malafarina, Daniele

    2011-01-15

    We consider here the classic scenario given by Oppenheimer, Snyder, and Datt, for the gravitational collapse of a massive matter cloud, and examine its stability under the introduction of small tangential stresses. We show, by offering an explicit class of physically valid tangential stress perturbations, that an introduction of tangential pressure, however small, can qualitatively change the final fate of collapse from a black hole final state to a naked singularity. This shows instability of black hole formation in collapse and sheds important light on the nature of cosmic censorship hypothesis and its possible formulations. The key effect of these perturbations is to alter the trapped surface formation pattern within the collapsing cloud and the apparent horizon structure. This allows the singularity to be visible, and implications are discussed.

  2. Electrodeposited cobalt sulfide hole collecting layer for polymer solar cells

    SciTech Connect (OSTI)

    Zampetti, Andrea; De Rossi, Francesca; Brunetti, Francesca; Reale, Andrea; Di Carlo, Aldo; Brown, Thomas M., E-mail: thomas.brown@uniroma2.it [CHOSE (Centre for Hybrid and Organic Solar Energy), Department of Electronic Engineering, University of Rome Tor Vergata, Via del Politecnico 1, 00133 Rome (Italy)

    2014-08-11

    In polymer solar cells based on the blend of regioregular poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester, the hole collecting layer has to be endowed with its ionization potential close to or greater than that of P3HT (?5?eV). Conductive polymer blends such as poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and metal oxides such as vanadium pentoxide (V{sub 2}O{sub 5}) and molybdenum trioxide (MoO{sub 3}) satisfy this requirement and have been the most common materials used so far in bulk heterojunction structures. We report here cobalt sulfide (CoS) to be a promising hole collecting material deposited by convenient and room temperature electrodeposition. By simply tuning the CoS electrodeposition parameters, power conversion efficiencies similar (within 15%) to a reference structure with PEDOT:PSS were obtained.

  3. Small drill-hole, gas mini-permeameter probe

    DOE Patents [OSTI]

    Molz, III, Fred J.; Murdoch, Lawrence C.; Dinwiddie, Cynthia L.; Castle, James W.

    2002-12-03

    The distal end of a basic tube element including a stopper device with an expandable plug is positioned in a pre-drilled hole in a rock face. Rotating a force control wheel threaded on the tube element exerts force on a sleeve that in turn causes the plug component of the stopper means to expand and seal the distal end of the tube in the hole. Gas under known pressure is introduced through the tube element. A thin capillary tube positioned in the tube element connects the distal end of the tube element to means to detect and display pressure changes and data that allow the permeability of the rock to be determined.

  4. Small drill-hole, gas mini-permeameter probe

    DOE Patents [OSTI]

    Molz, III, Fred J. (Seneca, SC); Murdoch, Lawrence C. (Clemson, SC); Dinwiddie, Cynthia L. (Central, SC); Castle, James W. (Clemson, SC)

    2002-01-01

    The distal end of a basic tube element including a stopper device with an expandable plug is positioned in a pre-drilled hole in a rock face. Rotating a force control wheel threaded on the tube element exerts force on a sleeve that in turn causes the plug component of the stopper means to expand and seal the distal end of the tube in the hole. Gas under known pressure is introduced through the tube element. A thin capillary tube positioned in the tube element connects the distal end of the tube element to means to detect and display pressure changes and data that allow the permeability of the rock to be determined.

  5. Selected stratigraphic data for drill holes located in Frenchman Flat, Nevada Test Site. Rev. 1

    SciTech Connect (OSTI)

    Drellack, S.L. Jr.

    1997-02-01

    Stratigraphic data are presented in tabular form for 72 holes drilled in Frenchman Flat, Nevada Test Site, between 1950 and 1993. Three pairs of data presentations are included for each hole: depth to formation tops, formation thicknesses, and formation elevations are presented in both field (English) and metric units. Also included for each hole, where available, are various construction data (hole depth, hole diameter, surface location coordinates) and certain information of hydrogeologic significance (depth to water level, top of zeolitization). The event name is given for holes associated with a particular nuclear test. An extensive set of footnotes is included, which indicates data sources and provides other information. The body of the report describes the stratigraphic setting of Frenchman Flat, gives drill-hole naming conventions and database terminology, and provides other background and reference material.

  6. Two Electron Holes in Hematite Facilitate Water Splitting

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Two Electron Holes in Hematite Facilitate Water Splitting Print Hydrogen is an attractive form of fuel because its only by-product is nonpolluting water vapor. The problem, however, is that the production of hydrogen-via the process of water splitting-currently requires the burning of traditional fossil fuels. Therefore, water splitting by photoelectrochemical cells (PECs) fueled by solar power has long been a primary goal of sustainable energy research. One roadblock to this goal is that the

  7. Two Electron Holes in Hematite Facilitate Water Splitting

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Two Electron Holes in Hematite Facilitate Water Splitting Print Hydrogen is an attractive form of fuel because its only by-product is nonpolluting water vapor. The problem, however, is that the production of hydrogen-via the process of water splitting-currently requires the burning of traditional fossil fuels. Therefore, water splitting by photoelectrochemical cells (PECs) fueled by solar power has long been a primary goal of sustainable energy research. One roadblock to this goal is that the

  8. Two Electron Holes in Hematite Facilitate Water Splitting

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Two Electron Holes in Hematite Facilitate Water Splitting Print Hydrogen is an attractive form of fuel because its only by-product is nonpolluting water vapor. The problem, however, is that the production of hydrogen-via the process of water splitting-currently requires the burning of traditional fossil fuels. Therefore, water splitting by photoelectrochemical cells (PECs) fueled by solar power has long been a primary goal of sustainable energy research. One roadblock to this goal is that the

  9. Two Electron Holes in Hematite Facilitate Water Splitting

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Two Electron Holes in Hematite Facilitate Water Splitting Print Hydrogen is an attractive form of fuel because its only by-product is nonpolluting water vapor. The problem, however, is that the production of hydrogen-via the process of water splitting-currently requires the burning of traditional fossil fuels. Therefore, water splitting by photoelectrochemical cells (PECs) fueled by solar power has long been a primary goal of sustainable energy research. One roadblock to this goal is that the

  10. Two Electron Holes in Hematite Facilitate Water Splitting

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Two Electron Holes in Hematite Facilitate Water Splitting Print Hydrogen is an attractive form of fuel because its only by-product is nonpolluting water vapor. The problem, however, is that the production of hydrogen-via the process of water splitting-currently requires the burning of traditional fossil fuels. Therefore, water splitting by photoelectrochemical cells (PECs) fueled by solar power has long been a primary goal of sustainable energy research. One roadblock to this goal is that the

  11. Two Electron Holes in Hematite Facilitate Water Splitting

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Two Electron Holes in Hematite Facilitate Water Splitting Print Hydrogen is an attractive form of fuel because its only by-product is nonpolluting water vapor. The problem, however, is that the production of hydrogen-via the process of water splitting-currently requires the burning of traditional fossil fuels. Therefore, water splitting by photoelectrochemical cells (PECs) fueled by solar power has long been a primary goal of sustainable energy research. One roadblock to this goal is that the

  12. COLLOQUIUM: Binary Black Hole and Neutron Star Collisions | Princeton

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Plasma Physics Lab December 16, 2015, 4:15pm to 5:30pm Colloquia MBG AUDITORIUM COLLOQUIUM: Binary Black Hole and Neutron Star Collisions Dr. Frans Pretorius Princeton University Binary compact object mergers are among the primary gravitational wave sources expected to be observed by the next generation of ground-based gravitational wave detectors. Mergers where one or both compact objects are neutron stars will further produce electromagnetic emission, and coincident observation of this

  13. Global solutions for higher-dimensional stretched small black holes

    SciTech Connect (OSTI)

    Chen, C.-M.; Gal'tsov, Dmitri V.; Ohta, Nobuyoshi; Orlov, Dmitry G.

    2010-01-15

    Small black holes in heterotic string theory have a vanishing horizon area at the supergravity level, but the horizon is stretched to the finite radius AdS{sub 2}xS{sup D-2} geometry once higher curvature corrections are turned on. This has been demonstrated to give good agreement with microscopic entropy counting. Previous considerations, however, were based on the classical local solutions valid only in the vicinity of the event horizon. Here we address the question of global existence of extremal black holes in the D-dimensional Einstein-Maxwell-Dilaton theory with the Gauss-Bonnet term introducing a variable dilaton coupling a as a parameter. We show that asymptotically flat black holes exist only in a bounded region of the dilaton couplings 0=}5 (but not for D=4) the allowed range of a includes the heterotic string values. For a>a{sub cr} numerical solutions meet weak naked singularities at finite radii r=r{sub cusp} (spherical cusps), where the scalar curvature diverges as |r-r{sub cusp}|{sup -1/2}. For D{>=}7 cusps are met in pairs, so that solutions can be formally extended to asymptotically flat infinity choosing a suitable integration variable. We show, however, that radial geodesics cannot be continued through the cusp singularities, so such a continuation is unphysical.

  14. Quenching of Excitons by Holes in Poly(3-hexylthiophene) Films

    SciTech Connect (OSTI)

    Ferguson, A. J .; Kopidakis, N.; Shaheen, S. E.; Rumbles, G.

    2008-01-01

    The generation of excitons and their interaction with holes in films of neat regioregular poly(3-hexylthiophene) and the polymer blended with 1 wt% of the electron-acceptor [6,6]-phenyl-C{sub 61}-butyric acid methyl ester (PCBM) have been studied using flash-photolysis time-resolved microwave conductivity. The sublinear relationship between the photogenerated hole density and the incident light intensity, in both the neat polymer and the donor-acceptor blend, can be attributed to the quenching of excitons by holes, at a rate characterized by a second-order rate constant ({gamma}{sub 2}) of 3 x 10{sup -8} cm{sup 3}/s. This value is larger than that found for other, luminescent conjugated polymers; the difference may be attributed to a greater collision probability, due to the higher mobility of the interacting species, or to an enhancement of the quenching rate once they are in close proximity. The phenomenon has consequences for the ultimate efficiency of organic photovoltaic solar cells that are based on the simple polymer:PCBM bulk heterojunction, especially under conditions of solar concentration.

  15. Quasiparticle random-phase approximation with interactions from...

    Office of Scientific and Technical Information (OSTI)

    Quasiparticle random-phase approximation with interactions from the Similarity Renormalization Group Citation Details In-Document Search Title: Quasiparticle random-phase ...

  16. Listening to the noise: random fluctuations reveal gene network...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Listening to the noise: random fluctuations reveal gene network parameters Citation Details In-Document Search Title: Listening to the noise: random fluctuations...

  17. 2015 Salishan Random Access (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Conference: 2015 Salishan Random Access Citation Details In-Document Search Title: 2015 Salishan Random Access You are accessing a document from the Department of Energy's (DOE) ...

  18. 2015 Salishan Random Access (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Conference: 2015 Salishan Random Access Citation Details In-Document Search Title: 2015 Salishan Random Access Authors: Vigil, Benny Manuel 1 ; Mattson, Tim 2 ; Coteus, Paul ...

  19. Stabilizing Topological Phases in Graphene via Random Adsorption...

    Office of Scientific and Technical Information (OSTI)

    Stabilizing Topological Phases in Graphene via Random Adsorption Prev Next Title: Stabilizing Topological Phases in Graphene via Random Adsorption Authors: Jiang, Hua ; Qiao,...

  20. Application of Random Vibration Theory Methodology for Seismic...

    Energy Savers [EERE]

    Application of Random Vibration Theory Methodology for Seismic Soil-Structure Interaction Analysis Application of Random Vibration Theory Methodology for Seismic Soil-Structure...

  1. A hole modulator for InGaN/GaN light-emitting diodes

    SciTech Connect (OSTI)

    Zhang, Zi-Hui; Kyaw, Zabu; Liu, Wei; Ji, Yun; Wang, Liancheng; Tan, Swee Tiam; Sun, Xiao Wei E-mail: VOLKAN@stanfordalumni.org; Demir, Hilmi Volkan E-mail: VOLKAN@stanfordalumni.org

    2015-02-09

    The low p-type doping efficiency of the p-GaN layer has severely limited the performance of InGaN/GaN light-emitting diodes (LEDs) due to the ineffective hole injection into the InGaN/GaN multiple quantum well (MQW) active region. The essence of improving the hole injection efficiency is to increase the hole concentration in the p-GaN layer. Therefore, in this work, we have proposed a hole modulator and studied it both theoretically and experimentally. In the hole modulator, the holes in a remote p-type doped layer are depleted by the built-in electric field and stored in the p-GaN layer. By this means, the overall hole concentration in the p-GaN layer can be enhanced. Furthermore, the hole modulator is adopted in the InGaN/GaN LEDs, which reduces the effective valance band barrier height for the p-type electron blocking layer from ?332?meV to ?294?meV at 80?A/cm{sup 2} and demonstrates an improved optical performance, thanks to the increased hole concentration in the p-GaN layer and thus the improved hole injection into the MQWs.

  2. FORMATION AND EVOLUTION OF CORONAL HOLES FOLLOWING THE EMERGENCE OF ACTIVE REGIONS

    SciTech Connect (OSTI)

    Wang, Y.-M.; Rouillard, A. P.; Sheeley, N. R.; Robbrecht, E.; Thernisien, A. F. R. E-mail: eva.robbrecht@oma.b E-mail: neil.sheeley@nrl.navy.mi

    2010-05-20

    The low level of solar activity over the past four years has provided unusually favorable conditions for tracking the formation and evolution of individual coronal holes and their wind streams. Employing extreme-ultraviolet images recorded with the Solar Terrestrial Relations Observatory during 2007-2009, we analyze three cases in which small coronal holes first appear at the edges of newly emerged active regions and then expand via flux transport processes, eventually becoming attached to the polar holes. The holes form gradually over timescales comparable to or greater than that for the active regions to emerge, without any obvious association with coronal mass ejections. The evolving hole areas coincide approximately with the footpoints of open field lines derived from potential-field source-surface extrapolations of the photospheric field. One of these coronal-hole systems, centered at the equator and maintained by a succession of old-cycle active regions emerging in the same longitude range, persists in one form or another for up to two years. The other two holes, located at midlatitudes and originating from new-cycle active regions, become strongly sheared and decay away after a few rotations. The hole boundaries and the small active-region holes, both of which are sources of slow wind, are observed to undergo continual short-term ({approx_lt}1 day) fluctuations on spatial scales comparable to that of the supergranulation. From in situ measurements, we identify a number of plasma sheets associated with pseudostreamers separating holes of the same polarity.

  3. Star formation and cosmic massive black hole formation, a universal process organized by angular momenta

    SciTech Connect (OSTI)

    Colgate, S. A.

    2004-01-01

    It is suggested that star formation is organized following the same principles as we have applied in a recent explanation of galaxy and massive black hole formation. In this scenario angular momentum is randomly distributed by tidal torquing among condensations, Lyman-{alpha} clouds or cores for star formation during the initial non-linear phase of collapse. This angular momentum is characterized by the parameter, {lambda}, the ratio of the angular momentum of the cloud to that of a Keplerian orbit with the same central mass and radius. This parameter is calculated in very many simulations of structure formation of the universe as well as core formation and appears to be universal and independent of any scale. The specific angular momentum during the collapse of every cloud is locally conserved and universally produces a near flat rotation curve M{sub hole, 10{sup 8} M{sub o}, ({sup -}10{sup -3} of the galactic disk mass) or 1 M{sub o} ({sup -}0.03 of the core or of the protostellar disk mass). The inviscid collapse of a protosteller core with the same average {lambda} = 0.05 leads to the formation of a flat rotation curve (protostellar) disk of mass M{sub dsk} {sup -}30 M{sub o} of radius R{sub dsk} {approx_equal} 1100 AU or 5.4 x 10{sup -3} pc. In such a disk {Sigma} {proportional_to} 1/R and reaches the RVI condition at R{sub crit} {approx_equal} 40 AU where M{sub

  4. Numerical renormalization-group study of a Kondo hole in a one-dimensional Kondo insulator

    SciTech Connect (OSTI)

    Yu, C.C.

    1996-12-01

    We have studied a Kondo hole in a one-dimensional Kondo insulator at half-filling using a density matrix formulation of the numerical renormalization group. The Kondo hole introduces midgap states. The spin density introduced by the hole is localized in the vicinity of the hole. It resides primarily in the {ital f} spins for small exchange coupling {ital J} and in the conduction spins for large {ital J}. We present results on the spin gap, charge gap, and neutral gap. The presence of the Kondo hole reduces the charge gap but not the spin gap relative to a Kondo insulator without defects. For small {ital J}, the spin gap is smaller than the charge gap, while for large {ital J}, the spin gap is larger than the charge gap. RKKY interactions are reduced by the Kondo hole as can be seen in the staggered susceptibility. {copyright} {ital 1996 The American Physical Society.}

  5. Black Holes in the Cosmos, the Lab, and in Fundamental Physics (2/3)

    ScienceCinema (OSTI)

    None

    2011-10-06

    Black holes present the extreme limits of physics. They are ubiquitous in the cosmos, and in some extra-dimensional scenarios they could be produced at colliders. They have also yielded a puzzle that challenges the foundations of physics. These talks will begin with an overview of the basics of black hole physics, and then briefly summarize some of the exciting developments with cosmic black holes. They will then turn to properties of quantum black holes, and the question of black hole production in high energy collisions, perhaps beginning with the LHC. I will then overview the apparent paradox emerging from Hawking's discovery of black hole evaporation, and what it could be teaching us about the foundations of quantum mechanics and gravity.

  6. Does the mass of a black hole decrease due to the accretion of phantom energy?

    SciTech Connect (OSTI)

    Gao Changjun; Chen Xuelei; Faraoni, Valerio; Shen Yougen

    2008-07-15

    According to Babichev et al., the accretion of a phantom test fluid onto a Schwarzschild black hole will induce the mass of the black hole to decrease, however the backreaction was ignored in their calculation. Using new exact solutions describing black holes in a background Friedmann-Robertson-Walker universe, we find that the physical black hole mass may instead increase due to the accretion of phantom energy. If this is the case, and the future universe is dominated by phantom dark energy, the black hole apparent horizon and the cosmic apparent horizon will eventually coincide and, after that, the black hole singularity will become naked in finite comoving time before the big rip occurs, violating the cosmic censorship conjecture.

  7. Black Holes in the Cosmos, the Lab, and in Fundamental Physics (3/3)

    ScienceCinema (OSTI)

    None

    2011-10-06

    Black holes present the extreme limits of physics. They are ubiquitous in the cosmos, and in some extra-dimensional scenarios they could be produced at colliders. They have also yielded a puzzle that challenges the foundations of physics. These talks will begin with an overview of the basics of black hole physics, and then briefly summarize some of the exciting developments with cosmic black holes. They will then turn to properties of quantum black holes, and the question of black hole production in high energy collisions, perhaps beginning with the LHC. I will then overview the apparent paradox emerging from Hawking's discovery of black hole evaporation, and what it could be teaching us about the foundations of quantum mechanics and gravity.

  8. Black Holes in the Cosmos, the Lab, and in Fundamental Physics (1/3)

    ScienceCinema (OSTI)

    None

    2011-10-06

    Black holes present the extreme limits of physics. They are ubiquitous in the cosmos, and in some extra-dimensional scenarios they could be produced at colliders. They have also yielded a puzzle that challenges the foundations of physics. These talks will begin with an overview of the basics of black hole physics, and then briefly summarize some of the exciting developments with cosmic black holes. They will then turn to properties of quantum black holes, and the question of black hole production in high energy collisions, perhaps beginning with the LHC. I will then overview the apparent paradox emerging from Hawking's discovery of black hole evaporation, and what it could be teaching us about the foundations of quantum mechanics and gravity.

  9. Minimum length, extra dimensions, modified gravity and black hole remnants

    SciTech Connect (OSTI)

    Maziashvili, Michael

    2013-03-01

    We construct a Hilbert space representation of minimum-length deformed uncertainty relation in presence of extra dimensions. Following this construction, we study corrections to the gravitational potential (back reaction on gravity) with the use of correspondingly modified propagator in presence of two (spatial) extra dimensions. Interestingly enough, for r?0 the gravitational force approaches zero and the horizon for modified Schwarzschild-Tangherlini space-time disappears when the mass approaches quantum-gravity energy scale. This result points out to the existence of zero-temperature black hole remnants in ADD brane-world model.

  10. Hole Blocking, Electron Transporting and Window Layer for Optimized

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Culn(1-x)GaxSe2 Solar Cells - Energy Innovation Portal Solar Photovoltaic Solar Photovoltaic Advanced Materials Advanced Materials Find More Like This Return to Search Hole Blocking, Electron Transporting and Window Layer for Optimized Culn(1-x)GaxSe2 Solar Cells Brookhaven National Laboratory Contact BNL About This Technology <br type="_moz" /> A schematic illustration of an exemplary embodiment of the disclosed CIGS based solar cell, with a quasi-2-dimensional electron

  11. Interacting spins and holes in zigzag edge nanographene

    SciTech Connect (OSTI)

    Dutta, Sudipta; Wakabayashi, Katsunori

    2013-12-04

    We have investigated charge and spin gap properties of zigzag edge graphene nanoribbons (ZGNRs) modeled within Hubbard Hamiltonian with onsite electron-electron interaction using semi-empirical many-body configuration interaction (CI) method. The charge gap behavior resembles the mean-field results, showing minima near Dirac point. We have observed unprecedented gap-less spin excitations over the flat band region. Moreover, doping the ZGNRs with holes reduces both the charge and spin gaps, inducing metallic and magnetic behavior, which can be exploited to fabricate spintronic devices.

  12. Black hole temperature: Minimal coupling vs conformal coupling

    SciTech Connect (OSTI)

    Fazel, Mohamadreza; Mirza, Behrouz; Mansoori, Seyed Ali Hosseini

    2014-05-15

    In this article, we discuss the propagation of scalar fields in conformally transformed spacetimes with either minimal or conformal coupling. The conformally coupled equation of motion is transformed into a one-dimensional Schrdinger-like equation with an invariant potential under conformal transformation. In a second stage, we argue that calculations based on conformal coupling yield the same Hawking temperature as those based on minimal coupling. Finally, it is conjectured that the quasi normal modes of black holes are invariant under conformal transformation.

  13. Quasilinear Carbon Transport In An Impurity Hole Plasma In LHD (Technical

    Office of Scientific and Technical Information (OSTI)

    Report) | SciTech Connect Technical Report: Quasilinear Carbon Transport In An Impurity Hole Plasma In LHD Citation Details In-Document Search Title: Quasilinear Carbon Transport In An Impurity Hole Plasma In LHD Comprehensive electrostatic gyrokinetic linear stability calculations for ion-scale microinstabilities in an LHD plasma with an ion-ITB and carbon "impurity hole" are used to make quasilinear estimates of particle flux to explore whether microturbulence can explain the

  14. High Temperature Tools and Sensors, Down-hole Pumps and Drilling |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy High Temperature Tools and Sensors, Down-hole Pumps and Drilling High Temperature Tools and Sensors, Down-hole Pumps and Drilling Below are the project presentations and respective peer review results for High Temperature Tools and Sensors, Down-hole Pumps and Drilling. Multiparameter Fiber Optic Sensing System for Monitoring Enhanced Geothermal Systems, Dr. Aaron J. Knobloch, GE Global Research High-Temperature-High-Volume Lifting for Enhanced Geothermal Systems, Norman

  15. Terahertz magneto-optical spectroscopy of a two-dimensional hole gas

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Terahertz magneto-optical spectroscopy of a two-dimensional hole gas Citation Details In-Document Search Title: Terahertz magneto-optical spectroscopy of a two-dimensional hole gas Two-dimensional hole gases (2DHGs) have attracted recent attention for their unique quantum physics and potential applications in areas including spintronics and quantum computing. However, their properties remain relatively unexplored, motivating the use of different techniques

  16. Two-hole bound states from a systematic low-energy effective field theory for magnons and holes in an antiferromagnet

    SciTech Connect (OSTI)

    Bruegger, C.; Kaempfer, F.; Moser, M.; Wiese, U.-J.; Pepe, M.

    2006-12-01

    Identifying the correct low-energy effective theory for magnons and holes in an antiferromagnet has remained an open problem for a long time. In analogy to the effective theory for pions and nucleons in QCD, based on a symmetry analysis of Hubbard and t-J-type models, we construct a systematic low-energy effective field theory for magnons and holes located inside pockets centered at lattice momenta ({+-}({pi}/2a),{+-}({pi}/2a)). The effective theory is based on a nonlinear realization of the spontaneously broken spin symmetry and makes model-independent universal predictions for the entire class of lightly doped antiferromagnetic precursors of high-temperature superconductors. The predictions of the effective theory are exact, order by order in a systematic low-energy expansion. We derive the one-magnon exchange potentials between two holes in an otherwise undoped system. Remarkably, in some cases the corresponding two-hole Schroedinger equations can even be solved analytically. The resulting bound states have d-wave characteristics. The ground state wave function of two holes residing in different hole pockets has a d{sub x{sup 2}-y{sup 2}}-like symmetry, while for two holes in the same pocket the symmetry resembles d{sub xy}.

  17. Slim Holes At Snake River Plain Region (DOE GTP) | Open Energy...

    Open Energy Info (EERE)

    Community Login | Sign Up Search Page Edit with form History Slim Holes At Snake River Plain Region (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home...

  18. Generalized uncertainty principle in f(R) gravity for a charged black hole

    SciTech Connect (OSTI)

    Said, Jackson Levi; Adami, Kristian Zarb

    2011-02-15

    Using f(R) gravity in the Palatini formularism, the metric for a charged spherically symmetric black hole is derived, taking the Ricci scalar curvature to be constant. The generalized uncertainty principle is then used to calculate the temperature of the resulting black hole; through this the entropy is found correcting the Bekenstein-Hawking entropy in this case. Using the entropy the tunneling probability and heat capacity are calculated up to the order of the Planck length, which produces an extra factor that becomes important as black holes become small, such as in the case of mini-black holes.

  19. Thermal Gradient Holes At Fish Lake Valley Area (DOE GTP) | Open...

    Open Energy Info (EERE)

    Fish Lake Valley Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Fish Lake Valley Area (DOE GTP)...

  20. Slim Holes At Fish Lake Valley Area (Deymonaz, Et Al., 2008)...

    Open Energy Info (EERE)

    Fish Lake Valley Area (Deymonaz, Et Al., 2008) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At Fish Lake Valley Area (Deymonaz, Et...

  1. Slim Holes At Salton Sea Area (Sabin, Et Al., 2010) | Open Energy...

    Open Energy Info (EERE)

    Salton Sea Area (Sabin, Et Al., 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At Salton Sea Area (Sabin, Et Al., 2010)...

  2. Thermal Gradient Holes At Twenty-Nine Palms Area (Sabin, Et Al...

    Open Energy Info (EERE)

    Sabin, Et Al., 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Twenty-Nine Palms Area (Sabin, Et Al., 2010)...

  3. Higgs production and decay from TeV scale black holes at the LHC (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Higgs production and decay from TeV scale black holes at the LHC Citation Details In-Document Search Title: Higgs production and decay from TeV scale black holes at the LHC We perform a detailed study of the Higgs production and decay, when Higgs is emitted from the black holes produced in proton-proton collisions at the Large Hadron Collider. We show that black hole production can significantly enhance the signal for the Higgs search at the LHC. We evaluate

  4. Core Holes At Lake City Hot Springs Area (Benoit Et Al., 2005...

    Open Energy Info (EERE)

    obtained from cuttings in this particular geologic setting. References Dick Benoit, Joe Moore, Colin Goranson, David Blackwell (2005) Core Hole Drilling And Testing At The Lake...

  5. Thermal Gradient Holes At Salt Wells Area (Bureau of Land Management...

    Open Energy Info (EERE)

    Salt Wells Area (Bureau of Land Management, 2009) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Salt Wells Area...

  6. Slim Holes At Salt Wells Area (Combs, Et Al., 1999) | Open Energy...

    Open Energy Info (EERE)

    Salt Wells Area (Combs, Et Al., 1999) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At Salt Wells Area (Combs, Et Al., 1999)...

  7. Terahertz magneto-optical spectroscopy of a two-dimensional hole...

    Office of Scientific and Technical Information (OSTI)

    DOE PAGES Search Results Accepted Manuscript: Terahertz magneto-optical spectroscopy of a two-dimensional hole gas Title: Terahertz magneto-optical spectroscopy of a...

  8. Microsoft Word - DOE-ID-13-053 Woods Hole EC B3-16.doc

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Uranium from Seawater: Studies under Real Ocean Conditions - Woods Hole Oceanographic ... and the best platform to expose, in high current regimes, these new fibers to the optimal ...

  9. Slim Holes At Gabbs Valley Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    Gabbs Valley Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At Gabbs Valley Area (DOE GTP) Exploration Activity...

  10. Slim Holes At Flint Geothermal Area (DOE GTP) | Open Energy Informatio...

    Open Energy Info (EERE)

    Flint Geothermal Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At Flint Geothermal Area (DOE GTP) Exploration...

  11. Slim Holes At Black Warrior Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    Black Warrior Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At Black Warrior Area (DOE GTP) Exploration Activity...

  12. Thermal Gradient Holes At Hot Pot Area (DOE GTP) | Open Energy...

    Open Energy Info (EERE)

    Pot Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Hot Pot Area (DOE GTP) Exploration Activity Details...

  13. Thermal Gradient Holes At Fort Bliss Area (DOE GTP) | Open Energy...

    Open Energy Info (EERE)

    Bliss Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Fort Bliss Area (DOE GTP) Exploration Activity...

  14. Slim Holes At Fort Bliss Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At Fort Bliss Area (DOE GTP) Exploration Activity Details Location Fort Bliss...

  15. Slim Holes At Silver Peak Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    Silver Peak Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At Silver Peak Area (DOE GTP) Exploration Activity Details...

  16. Thermal Gradient Holes At Alum Area (DOE GTP) | Open Energy Informatio...

    Open Energy Info (EERE)

    Alum Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Alum Area (DOE GTP) Exploration Activity Details...

  17. Slim Holes At Glass Buttes Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    Glass Buttes Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At Glass Buttes Area (DOE GTP) Exploration Activity...

  18. Slim Holes At Newberry Caldera Area (DOE GTP) | Open Energy Informatio...

    Open Energy Info (EERE)

    DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At Newberry Caldera Area (DOE GTP) Exploration Activity Details Location...

  19. Slim Holes At New River Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    New River Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At New River Area (DOE GTP) Exploration Activity Details...

  20. Slim Holes At Jemez Pueblo Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    Jemez Pueblo Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At Jemez Pueblo Area (DOE GTP) Exploration Activity...

  1. Slim Holes At Hot Pot Area (DOE GTP) | Open Energy Information

    Open Energy Info (EERE)

    Hot Pot Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At Hot Pot Area (DOE GTP) Exploration Activity Details Location...

  2. Thermal Gradient Holes At Silver Peak Area (DOE GTP) | Open Energy...

    Open Energy Info (EERE)

    Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Silver Peak Area (DOE GTP) Exploration Activity Details Location...

  3. Thermal Gradient Holes At Kilauea East Rift Area (Quane, Et Al...

    Open Energy Info (EERE)

    Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes At Kilauea East Rift Area (Quane, Et Al., 2000) Exploration Activity...

  4. Space X-ray Solves Mysteries of Black Holes | Department of Energy

    Energy Savers [EERE]

    Space X-ray Solves Mysteries of Black Holes Space X-ray Solves Mysteries of Black Holes March 13, 2013 - 3:57pm Addthis Space X-ray Solves Mysteries of Black Holes Anne M. Stark Senior Public Information Officer, Lawrence Livermore National Laboratory "We know that black holes have a strong link to their host galaxy." Astrophysicist Bill Craig, a member of the LLNL team An international team including Lawrence Livermore National Laboratory scientists has definitively measured the spin

  5. Core Holes At Kilauea East Rift Geothermal Area (Bargar, Et Al...

    Open Energy Info (EERE)

    Kilauea East Rift Geothermal Area (Bargar, Et Al., 1995) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Core Holes At Kilauea East Rift...

  6. GRAVITATIONAL WAVE SIGNATURES IN BLACK HOLE FORMING CORE COLLAPSE

    SciTech Connect (OSTI)

    Cerd-Durn, Pablo; DeBrye, Nicolas; Aloy, Miguel A.; Font, Jos A.; Obergaulinger, Martin

    2013-12-20

    We present general relativistic numerical simulations of collapsing stellar cores. Our initial model consists of a low metallicity rapidly-rotating progenitor which is evolved in axisymmetry with the latest version of our general relativistic code CoCoNuT, which allows for black hole formation and includes the effects of a microphysical equation of state (LS220) and a neutrino leakage scheme to account for radiative losses. The motivation of our study is to analyze in detail the emission of gravitational waves in the collapsar scenario of long gamma-ray bursts. Our simulations show that the phase during which the proto-neutron star (PNS) survives before ultimately collapsing to a black hole is particularly optimal for gravitational wave emission. The high-amplitude waves last for several seconds and show a remarkable quasi-periodicity associated with the violent PNS dynamics, namely during the episodes of convection and the subsequent nonlinear development of the standing-accretion shock instability (SASI). By analyzing the spectrogram of our simulations we are able to identify the frequencies associated with the presence of g-modes and with the SASI motions at the PNS surface. We note that the gravitational waves emitted reach large enough amplitudes to be detected with third-generation detectors such as the Einstein Telescope within a Virgo Cluster volume at rates ? 0.1yr{sup 1}.

  7. CALIBRATING C-IV-BASED BLACK HOLE MASS ESTIMATORS

    SciTech Connect (OSTI)

    Park, Daeseong; Woo, Jong-Hak; Shin, Jaejin [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of); Denney, Kelly D., E-mail: pds2001@astro.snu.ac.kr, E-mail: woo@astro.snu.ac.kr, E-mail: jjshin@astro.snu.ac.kr, E-mail: kelly@dark-cosmology.dk [Dark Cosmology Centre, Niels Bohr Institute, Juliane Maries Vej 30, DK-2100 Copenhagen O (Denmark)

    2013-06-20

    We present the single-epoch black hole mass estimators based on the C IV {lambda}1549 broad emission line, using the updated sample of the reverberation-mapped active galactic nuclei and high-quality UV spectra. By performing multi-component spectral fitting analysis, we measure the C IV line widths (FWHM{sub C{sub IV}} and line dispersion, {sigma}{sub C{sub IV}}) and the continuum luminosity at 1350 A (L{sub 1350}) to calibrate the C-IV-based mass estimators. By comparing with the H{beta} reverberation-based masses, we provide new mass estimators with the best-fit relationships, i.e., M{sub BH}{proportional_to}L{sub 1350}{sup 0.50{+-}0.07}{sigma}{sub C{sub IV}{sup 2}} and M{sub BH}{proportional_to}L{sub 1350}{sup 0.52{+-}0.09} FWHM{sub C{sub IV}{sup 0.56{+-}0.48}}. The new C-IV-based mass estimators show significant mass-dependent systematic difference compared to the estimators commonly used in the literature. Using the published Sloan Digital Sky Survey QSO catalog, we show that the black hole mass of high-redshift QSOs decreases on average by {approx}0.25 dex if our recipe is adopted.

  8. Effects of intermediate mass black holes on nuclear star clusters

    SciTech Connect (OSTI)

    Mastrobuono-Battisti, Alessandra; Perets, Hagai B.; Loeb, Abraham

    2014-11-20

    Nuclear star clusters (NSCs) are dense stellar clusters observed in galactic nuclei, typically hosting a central massive black hole. Here we study the possible formation and evolution of NSCs through the inspiral of multiple star clusters hosting intermediate mass black holes (IMBHs). Using an N-body code, we examine the dynamics of the IMBHs and their effects on the NSC. We find that IMBHs inspiral to the core of the newly formed NSC and segregate there. Although the IMBHs scatter each other and the stars, none of them is ejected from the NSC. The IMBHs are excited to high eccentricities and their radial density profile develops a steep power-law cusp. The stars also develop a power-law cusp (instead of the central core that forms in their absence), but with a shallower slope. The relaxation rate of the NSC is accelerated due to the presence of IMBHs, which act as massive perturbers. This in turn fills the loss cone and boosts the tidal disruption rate of stars both by the MBH and the IMBHs to a value excluded by rate estimates based on current observations. Rate estimates of tidal disruptions can therefore provide a cumulative constraint on the existence of IMBHs in NSCs.

  9. Resilience of complex networks to random breakdown

    SciTech Connect (OSTI)

    Paul, Gerald; Sreenivasan, Sameet; Stanley, H. Eugene

    2005-11-01

    Using Monte Carlo simulations we calculate f{sub c}, the fraction of nodes that are randomly removed before global connectivity is lost, for networks with scale-free and bimodal degree distributions. Our results differ from the results predicted by an equation for f{sub c} proposed by Cohen et al. We discuss the reasons for this disagreement and clarify the domain for which the proposed equation is valid.

  10. Random one-of-N selector

    DOE Patents [OSTI]

    Kronberg, J.W.

    1993-04-20

    An apparatus for selecting at random one item of N items on the average comprising counter and reset elements for counting repeatedly between zero and N, a number selected by the user, a circuit for activating and deactivating the counter, a comparator to determine if the counter stopped at a count of zero, an output to indicate an item has been selected when the count is zero or not selected if the count is not zero. Randomness is provided by having the counter cycle very often while varying the relatively longer duration between activation and deactivation of the count. The passive circuit components of the activating/deactivating circuit and those of the counter are selected for the sensitivity of their response to variations in temperature and other physical characteristics of the environment so that the response time of the circuitry varies. Additionally, the items themselves, which may be people, may vary in shape or the time they press a pushbutton, so that, for example, an ultrasonic beam broken by the item or person passing through it will add to the duration of the count and thus to the randomness of the selection.

  11. Random one-of-N selector

    DOE Patents [OSTI]

    Kronberg, James W. (353 Church Rd., Beech Island, SC 29841)

    1993-01-01

    An apparatus for selecting at random one item of N items on the average comprising counter and reset elements for counting repeatedly between zero and N, a number selected by the user, a circuit for activating and deactivating the counter, a comparator to determine if the counter stopped at a count of zero, an output to indicate an item has been selected when the count is zero or not selected if the count is not zero. Randomness is provided by having the counter cycle very often while varying the relatively longer duration between activation and deactivation of the count. The passive circuit components of the activating/deactivating circuit and those of the counter are selected for the sensitivity of their response to variations in temperature and other physical characteristics of the environment so that the response time of the circuitry varies. Additionally, the items themselves, which may be people, may vary in shape or the time they press a pushbutton, so that, for example, an ultrasonic beam broken by the item or person passing through it will add to the duration of the count and thus to the randomness of the selection.

  12. Electrokinetic transport in microchannels with random roughness

    SciTech Connect (OSTI)

    Wang, Moran [Los Alamos National Laboratory; Kang, Qinjun [Los Alamos National Laboratory

    2008-01-01

    We present a numerical framework to model the electrokinetic transport in microchannels with random roughness. The three-dimensional microstructure of the rough channel is generated by a random generation-growth method with three statistical parameters to control the number density, the total volume fraction, and the anisotropy characteristics of roughness elements. The governing equations for the electrokinetic transport are solved by a high-efficiency lattice Poisson?Boltzmann method in complex geometries. The effects from the geometric characteristics of roughness on the electrokinetic transport in microchannels are therefore modeled and analyzed. For a given total roughness volume fraction, a higher number density leads to a lower fluctuation because of the random factors. The electroosmotic flow rate increases with the roughness number density nearly logarithmically for a given volume fraction of roughness but decreases with the volume fraction for a given roughness number density. When both the volume fraction and the number density of roughness are given, the electroosmotic flow rate is enhanced by the increase of the characteristic length along the external electric field direction but is reduced by that in the direction across the channel. For a given microstructure of the rough microchannel, the electroosmotic flow rate decreases with the Debye length. It is found that the shape resistance of roughness is responsible for the flow rate reduction in the rough channel compared to the smooth channel even for very thin double layers, and hence plays an important role in microchannel electroosmotic flows.

  13. Realization of solid-state nanothermometer using Ge quantum-dot single-hole transistor in few-hole regime

    SciTech Connect (OSTI)

    Chen, I. H.; Lai, W. T.; Li, P. W.

    2014-06-16

    Semiconductor Ge quantum-dot (QD) thermometry has been demonstrated based on extraordinary temperature-dependent oscillatory differential conductance (G{sub D}) characteristics of Ge-QD single-hole transistors (SHTs) in the few-hole regime. Full-voltage width-at-half-minimum, V{sub 1/2}, of G{sub D} valleys appears to be fairly linear in the charge number (n) and temperature within the QD in a relationship of eV{sub 1/2}???(1???0.11n)??5.15k{sub B}T, providing the primary thermometric quantity. The depth of G{sub D} valley is also proportional to charging energy (E{sub C}) and 1/T via ?G{sub D}???E{sub C}/9.18k{sub B}T, providing another thermometric quantity. This experimental demonstration suggests our Ge-QD SHT offering effective building blocks for nanothermometers over a wide temperature range with a detection temperature as high as 155?K in a spatial resolution less than 10?nm and temperature accuracy of sub-kelvin.

  14. Hawking radiation of scalar particles from accelerating and rotating black holes

    SciTech Connect (OSTI)

    Gillani, Usman A.; Rehman, Mudassar; Saifullah, K. E-mail: mudassar051@yahoo.com

    2011-06-01

    Hawking radiation of uncharged and charged scalar particles from accelerating and rotating black holes is studied. We calculate the tunneling probabilities of these particles from the rotation and acceleration horizons of these black holes. Using this method we recover the correct Hawking temperature as well.

  15. X-ray technology behind NASA's black-hole hunter (NuSTAR)

    SciTech Connect (OSTI)

    Craig, Bill

    2013-09-10

    Livermore Lab astrophysicist Bill Craig describes his team's role in developing X-ray imaging technology for the NASA Nuclear Spectroscopic Telescope Array (NuSTAR) mission. The black-hole-hunting spacecraft bagged its first 10 supermassive black holes this week

  16. X-ray technology behind NASA's black-hole hunter (NuSTAR)

    ScienceCinema (OSTI)

    Craig, Bill

    2014-05-22

    Livermore Lab astrophysicist Bill Craig describes his team's role in developing X-ray imaging technology for the NASA Nuclear Spectroscopic Telescope Array (NuSTAR) mission. The black-hole-hunting spacecraft bagged its first 10 supermassive black holes this week

  17. Preliminary results and status report of the Hawaiian Scientific Observation Hole program

    SciTech Connect (OSTI)

    Olson, Harry J.; Deymonaz, John E.

    1992-01-01

    The Hawaii Natural Energy Institute (HNEI), an institute within the School of Ocean and Earth Science and Technology, at the University of Hawaii at Manoa has drilled three Scientific Observation Holes (SOH) in the Kilauea East Rift Zone to assess the geothermal potential of the Big Island of Hawaii, and to stimulate private development of the resource. The first hole drilled, SOH-4, reached a depth of 2,000 meters and recorded a bottom hole temperature of 306 C. Although evidence of fossil reservoir conditions were encountered, no zones with obvious reservoir potential were found. The second hole, SOH- 1, was drilled to a depth of 1,684 meters, recorded a bottom hole temperature of 206.1 C and effectively defined the northern limit of the Hawaii Geothermal Project-Abbott--Puna Geothermal Venture (HGP-A/PGV) reservoir. The final hole, SOH-2, was drilled to a depth of 2,073 meters, recorded a bottom hole temperature of 350.5 C and has sufficient indicated permeability to be designated as a potential ''discovery''. The SOH program was also highly successful in developing slim hole drilling techniques and establishing subsurface geological conditions.

  18. The electron beam hole drilling of silicon nitride thin films

    SciTech Connect (OSTI)

    Howitt, D. G.; Chen, S. J.; Gierhart, B. C.; Smith, R. L.; Collins, S. D.

    2008-01-15

    The mechanism by which an intense electron beam can produce holes in thin films of silicon nitride has been investigated using a combination of in situ electron energy loss spectrometry and electron microscopy imaging. A brief review of electron beam interactions that lead to material loss in different materials is also presented. The loss of nitrogen and silicon decreases with decreasing beam energy and although still observable at a beam energy of 150 keV ceases completely at 120 keV. The linear behavior of the loss rate coupled with the energy dependency indicates that the process is primarily one of direct displacement, involving the sputtering of atoms from the back surface of the specimen with the rate controlling mechanism being the loss of nitrogen.

  19. AnalyzeHOLE: An Integrated Wellbore Flow Analysis Tool

    SciTech Connect (OSTI)

    Keith J. Halford

    2009-10-01

    Conventional interpretation of flow logs assumes that hydraulic conductivity is directly proportional to flow change with depth. However, well construction can significantly alter the expected relation between changes in fluid velocity and hydraulic conductivity. Strong hydraulic conductivity contrasts between lithologic intervals can be masked in continuously screened wells. Alternating intervals of screen and blank casing also can greatly complicate the relation between flow and hydraulic properties. More permeable units are not necessarily associated with rapid fluid-velocity increases. Thin, highly permeable units can be misinterpreted as thick and less permeable intervals or not identified at all. These conditions compromise standard flow-log interpretation because vertical flow fields are induced near the wellbore. AnalyzeHOLE, an integrated wellbore analysis tool for simulating flow and transport in wells and aquifer systems, provides a better alternative for simulating and evaluating complex well-aquifer system interaction. A pumping well and adjacent aquifer system are simulated with an axisymmetric, radial geometry in a two-dimensional MODFLOW model. Hydraulic conductivities are distributed by depth and estimated with PEST by minimizing squared differences between simulated and measured flows and drawdowns. Hydraulic conductivity can vary within a lithology but variance is limited with regularization. Transmissivity of the simulated system also can be constrained to estimates from single-well, pumping tests. Water-quality changes in the pumping well are simulated with simple mixing models between zones of differing water quality. These zones are differentiated by backtracking thousands of particles from the well screens with MODPATH. An Excel spreadsheet is used to interface the various components of AnalyzeHOLE by (1) creating model input files, (2) executing MODFLOW, MODPATH, PEST, and supporting FORTRAN routines, and (3) importing and graphically displaying pertinent results.

  20. Recoiling supermassive black holes: a search in the nearby universe

    SciTech Connect (OSTI)

    Lena, D.; Robinson, A.; Axon, D. J.; Merritt, D.; Marconi, A.; Capetti, A.; Batcheldor, D.

    2014-11-10

    The coalescence of a binary black hole can be accompanied by a large gravitational recoil due to anisotropic emission of gravitational waves. A recoiling supermassive black hole (SBH) can subsequently undergo long-lived oscillations in the potential well of its host galaxy, suggesting that offset SBHs may be common in the cores of massive ellipticals. We have analyzed Hubble Space Telescope archival images of 14 nearby core ellipticals, finding evidence for small (? 10 pc) displacements between the active galactic nucleus (AGN; the location of the SBH) and the center of the galaxy (the mean photocenter) in 10 of them. Excluding objects that may be affected by large-scale isophotal asymmetries, we consider six galaxies to have detected displacements, including M87, where a displacement was previously reported by Batcheldor et al. In individual objects, these displacements can be attributed to residual gravitational recoil oscillations following a major or minor merger within the last few gigayears. For plausible merger rates, however, there is a high probability of larger displacements than those observed, if SBH coalescence took place in these galaxies. Remarkably, the AGN-photocenter displacements are approximately aligned with the radio source axis in four of the six galaxies with displacements, including three of the four having relatively powerful kiloparsec-scale jets. This suggests intrinsic asymmetries in radio jet power as a possible displacement mechanism, although approximate alignments are also expected for gravitational recoil. Orbital motion in SBH binaries and interactions with massive perturbers can produce the observed displacement amplitudes but do not offer a ready explanation for the alignments.

  1. RECOILING SUPERMASSIVE BLACK HOLES IN SPIN-FLIP RADIO GALAXIES

    SciTech Connect (OSTI)

    Liu, F. K.; Wang Dong; Chen Xian

    2012-02-20

    Numerical relativity simulations predict that coalescence of supermassive black hole (SMBH) binaries leads not only to a spin flip but also to a recoiling of the merger remnant SMBHs. In the literature, X-shaped radio sources are popularly suggested to be candidates for SMBH mergers with spin flip of jet-ejecting SMBHs. Here we investigate the spectral and spatial observational signatures of the recoiling SMBHs in radio sources undergoing black hole spin flip. Our results show that SMBHs in most spin-flip radio sources have mass ratio q {approx}> 0.3 with a minimum possible value q{sub min} {approx_equal} 0.05. For major mergers, the remnant SMBHs can get a kick velocity as high as 2100 km s{sup -1} in the direction within an angle {approx}< 40 Degree-Sign relative to the spin axes of remnant SMBHs, implying that recoiling quasars are biased to be with high Doppler-shifted broad emission lines while recoiling radio galaxies are biased to large apparent spatial off-center displacements. We also calculate the distribution functions of line-of-sight velocity and apparent spatial off-center displacements for spin-flip radio sources with different apparent jet reorientation angles. Our results show that the larger the apparent jet reorientation angle is, the larger the Doppler-shifting recoiling velocity and apparent spatial off-center displacement will be. We investigate the effects of recoiling velocity on the dust torus in spin-flip radio sources and suggest that recoiling of SMBHs would lead to 'dust-poor' active galactic nuclei. Finally, we collect a sample of 19 X-shaped radio objects and for each object give the probability of detecting the predicted signatures of recoiling SMBH.

  2. Geothermal reservoir assessment based on slim hole drilling. Volume 1, Analytical Method: Final report

    SciTech Connect (OSTI)

    Olson, H.J.

    1993-12-01

    The Hawaii Scientific Observation Hole (SOH) program was supplied by the State of Hawaii to drill six, 4,000 foot scientific observation holes on Maui and the Big Island of Hawaii to confirm and stimulate geothermal, resource development in Hawaii. After a lengthy permitting process, three SOHs, totaling 18,890 feet of mostly core drilling were finally drilled along the Kilauea East Rift Zone (KERZ) in the Puna district on the Big Island. The SOH program was highly successful in meeting the highly restrictive permitting conditions imposed on the program, and in developing slim hole drilling techniques, establishing subsurface geological conditions, and initiating an assessment and characterization of the geothermal resources potential of Hawaii - even though permitting specifically prohibited pumping or flowing the holes to obtain data of subsurface fluid conditions. The first hole, SOH-4, reached a depth of 2,000 meters, recorded a bottom hole temperature of 306.1 C, and established subsurface thermal continuity along the KERZ between the HGP-A and the True/Mid-Pacific Geothermal Venture wells. Although evidence of fossil reservoir conditions were encountered, no zones with obvious reservoir potential were found. The second hole SOH-1, was drilled to a depth of 1,684 meters, recorded a bottom hole temperature of 206.1 C, effectively doubled the size of the Hawaii Geothermal Project -- Abbott/Puna Geothermal Venture (HGP-A/PGV) proven/probable reservoir, and defined the northern limit of the HGP-A/PGV reservoir. The final hole, SOH-2, was drilled to a depth of 2,073 meters, recorded a bottom hole temperature of 350.5 C, and has sufficient indicated permeability to be designated as a potential ''discovery.''

  3. Geothermal reservoir assessment based on slim hole drilling. Volume 2: Application in Hawaii: Final report

    SciTech Connect (OSTI)

    Olson, H.J.

    1993-12-01

    The Hawaii Scientific Observation Hole (SOH) program was planned, funded, and initiated in 1988 by the Hawaii Natural Energy Institute, an institute within the School of Ocean and Earth Science and Technology, at the University of Hawaii at Manoa. Initial funding for the SOH program was $3.25 million supplied by the State of Hawaii to drill six, 4,000 foot scientific observation holes on Maui and the Big Island of Hawaii to confirm and stimulate geothermal resource development in Hawaii. After a lengthy permitting process, three SOHs, totaling 18,890 feet of mostly core drilling were finally drilled along the Kilauea East Rift Zone (KERZ) in the Puna district on the Big Island. The SOH program was highly successful in meeting the highly restrictive permitting conditions imposed on the program, and in developing slim hole drilling techniques, establishing subsurface geological conditions, and initiating an assessment and characterization of the geothermal resources potential of Hawaii - - even though permitting specifically prohibited pumping or flowing the holes to obtain data of subsurface fluid conditions. The first hole, SOH-4, reached a depth of 2,000 meters, recorded a/bottom hole temperature of 306.1 C, and established subsurface thermal continuity along the KERZ between the HGP-A and the True/Mid-Pacific Geothermal Venture wells. Although evidence of fossil reservoir conditions were encountered, no zones with obvious reservoir potential were found. The second hole SOH-1, was drilled to a depth of 1,684 meters, recorded a bottom hole temperature of 206.1 C, effectively doubled the size of the Hawaii Geothermal Project-Abbott/Puna Geothermal Venture (HGP-A/PGV) proven/probable reservoir, and defined the northern limit of the HGP-A/PGV reservoir. The final hole, SOH-2, was drilled to a depth of 2,073 meters, recorded a bottom hole temperature of 350.5 C, and has sufficient indicated permeability to be designated as a potential discovery.

  4. Investigation of high hole mobility In{sub 0.41}Ga{sub 0.59}Sb...

    Office of Scientific and Technical Information (OSTI)

    on hole mobility at different temperature range. The sheet hole density keeps almost constantly from 300 K to 77 K. This study shows great potential of Insub 0.41Gasub ...

  5. Livermore Random I/O Testbench

    Energy Science and Technology Software Center (OSTI)

    2012-09-01

    LRIOT is a test bench framework that is designed to generate sophisticated I/O rates that can stress high-performance memory and storage systems, such as non-volatile random access memories (NVRAM)and storage class memory. Furthermore, LRIOT provides the capabilities to mix multiple types of concurrency, namely threading and task parallelism, as well as distributed execution using Message Passing Interface (MPI) libraries. It will be used by algorithm designers to generate access patterns that mimic their application's behavior,more » and by system designers to test high-performance NVRAM storage.« less

  6. Statistical analysis of random duration times

    SciTech Connect (OSTI)

    Engelhardt, M.E.

    1996-04-01

    This report presents basic statistical methods for analyzing data obtained by observing random time durations. It gives nonparametric estimates of the cumulative distribution function, reliability function and cumulative hazard function. These results can be applied with either complete or censored data. Several models which are commonly used with time data are discussed, and methods for model checking and goodness-of-fit tests are discussed. Maximum likelihood estimates and confidence limits are given for the various models considered. Some results for situations where repeated durations such as repairable systems are also discussed.

  7. Experimental Analysis of a Piezoelectric Energy Harvesting System for Harmonic, Random, and Sine on Random Vibration

    SciTech Connect (OSTI)

    Cryns, Jackson W.; Hatchell, Brian K.; Santiago-Rojas, Emiliano; Silvers, Kurt L.

    2013-07-01

    Formal journal article Experimental analysis of a piezoelectric energy harvesting system for harmonic, random, and sine on random vibration Abstract: Harvesting power with a piezoelectric vibration powered generator using a full-wave rectifier conditioning circuit is experimentally compared for varying sinusoidal, random and sine on random (SOR) input vibration scenarios. Additionally, the implications of source vibration characteristics on harvester design are discussed. Studies in vibration harvesting have yielded numerous alternatives for harvesting electrical energy from vibrations but piezoceramics arose as the most compact, energy dense means of energy transduction. The rise in popularity of harvesting energy from ambient vibrations has made piezoelectric generators commercially available. Much of the available literature focuses on maximizing harvested power through nonlinear processing circuits that require accurate knowledge of generator internal mechanical and electrical characteristics and idealization of the input vibration source, which cannot be assumed in general application. In this manuscript, variations in source vibration and load resistance are explored for a commercially available piezoelectric generator. We characterize the source vibration by its acceleration response for repeatability and transcription to general application. The results agree with numerical and theoretical predictions for in previous literature that load optimal resistance varies with transducer natural frequency and source type, and the findings demonstrate that significant gains are seen with lower tuned transducer natural frequencies for similar source amplitudes. Going beyond idealized steady state sinusoidal and simplified random vibration input, SOR testing allows for more accurate representation of real world ambient vibration. It is shown that characteristic interactions from more complex vibrational sources significantly alter power generation and power processing requirements by increasing harvested power, shifting optimal conditioning impedance, inducing significant voltage supply fluctuations and ultimately rendering idealized sinusoidal and random analyses insufficient.

  8. Global temperature deviations as a random walk

    SciTech Connect (OSTI)

    Karner, O.

    1996-12-31

    Surface air temperature is the main parameter to represent the earth`s contemporary climate. Several historical temperature records on a global/monthly basis are available. Time-series analysis shows that they can be modelled via autoregressive moving average models closely connected to the classical random walk model. Fitted models emphasize a nonstationary character of the global/monthly temperature deviation from a certain level. The nonstationarity explains all trends and periods, found in the last century`s variability of global mean temperature. This means that the short-term temperature trends are inevitable and may have little in common with a currently increasing carbon dioxide amount. The calculations show that a reasonable understanding of the contemporary global mean climate is attainable, assuming random forcing to the climate system and treating temperature deviation as a response to it. The forcings occur due to volcanic eruptions, redistribution of cloudiness, variations in snow and ice covered areas, changes in solar output, etc. Their impact can not be directly estimated from changes of the earth`s radiation budget at the top of the atmosphere, because actual measurements represent mixture of the forcings and responses. Thus, it is impossible empirically to separate the impact of one particular forcing (e.g., that due to increase of CO{sub 2} amount) from the sequence of all existing forcings in the earth climate system. More accurate modelling involving main feedback loops is necessary to ease such a separation.

  9. Random unitary maps for quantum state reconstruction

    SciTech Connect (OSTI)

    Merkel, Seth T. [Institute for Quantum Computing, Waterloo, Ontario N2L 3G1 (Canada); Riofrio, Carlos A.; Deutsch, Ivan H. [Center for Quantum Information and Control (CQuIC), Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico, 87131 (United States); Flammia, Steven T. [Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5 (Canada); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States)

    2010-03-15

    We study the possibility of performing quantum state reconstruction from a measurement record that is obtained as a sequence of expectation values of a Hermitian operator evolving under repeated application of a single random unitary map, U{sub 0}. We show that while this single-parameter orbit in operator space is not informationally complete, it can be used to yield surprisingly high-fidelity reconstruction. For a d-dimensional Hilbert space with the initial observable in su(d), the measurement record lacks information about a matrix subspace of dimension {>=}d-2 out of the total dimension d{sup 2}-1. We determine the conditions on U{sub 0} such that the bound is saturated, and show they are achieved by almost all pseudorandom unitary matrices. When we further impose the constraint that the physical density matrix must be positive, we obtain even higher fidelity than that predicted from the missing subspace. With prior knowledge that the state is pure, the reconstruction will be perfect (in the limit of vanishing noise) and for arbitrary mixed states, the fidelity is over 0.96, even for small d, and reaching F>0.99 for d>9. We also study the implementation of this protocol based on the relationship between random matrices and quantum chaos. We show that the Floquet operator of the quantum kicked top provides a means of generating the required type of measurement record, with implications on the relationship between quantum chaos and information gain.

  10. Low-temperature random matrix theory at the soft edge

    SciTech Connect (OSTI)

    Edelman, Alan; Persson, Per-Olof; Sutton, Brian D.

    2014-06-15

    Low temperature random matrix theory is the study of random eigenvalues as energy is removed. In standard notation, ? is identified with inverse temperature, and low temperatures are achieved through the limit ? ? ?. In this paper, we derive statistics for low-temperature random matrices at the soft edge, which describes the extreme eigenvalues for many random matrix distributions. Specifically, new asymptotics are found for the expected value and standard deviation of the general-? Tracy-Widom distribution. The new techniques utilize beta ensembles, stochastic differential operators, and Riccati diffusions. The asymptotics fit known high-temperature statistics curiously well and contribute to the larger program of general-? random matrix theory.

  11. Chemical aspects of cylinder corrosion and a scenario for hole development

    SciTech Connect (OSTI)

    Barber, E.J.

    1991-12-31

    In June 1990, two cylinders in the depleted UF{sub 6} cylinder storage yards at Portsmouth were discovered to have holes in their walls at the valve-end stiffening ring at a point below the level of the gas-solid interface of the UF{sub 6}. The cylinder with the larger hole, which extended under the stiffening ring, was stacked in a top row 13 years ago. The cylinder with the smaller hole had been stacked in a bottom row 4 years ago. The lifting lugs of the adjacent cylinders pointed directly at the holes. A Cylinder Investigating Committee was appointed to determine the cause or causes of the holes and to assess the implications of these findings. This report contains a listing of the chemically related facts established by the Investigating Committee with the cooperation of the Operations and Technical Support Divisions at the Portsmouth Gaseous Diffusion Plant, the scenario developed to explain these findings and some implications of this scenario. In summary, the interrelated reactions of water, solid UF{sub 6} and iron presented by R. L. Ritter are used to develop a scenario which explains the observations and deductions made during the investigation. The chemical processes are intimately related to the course of the last three of the four stages of hole development. A simple model is proposed which permits semiquantitative prediction of such information as the HF loss rates as a function of time, the rate of hole enlargement, the time to hydrolyze a cylinder of UF{sub 6} and the approximate size of the hole. The scenario suggests that the environmental consequences associated with a developing hole in a depleted UF{sub 6} cylinder are minimal for the first several years but will become significant if too many years pass before detection. The overall environmental picture is presented in more detail elsewhere.

  12. General Nonextremal Rotating Black Holes in Minimal Five-Dimensional Gauged Supergravity

    SciTech Connect (OSTI)

    Chong, Z.-W.; Lue, H.; Pope, C.N.; Cvetic, M.

    2005-10-14

    We construct the general solution for nonextremal charged rotating black holes in five-dimensional minimal gauged supergravity. They are characterized by four nontrivial parameters: namely, the mass, the charge, and the two independent rotation parameters. The metrics in general describe regular rotating black holes, providing the parameters lie in appropriate ranges so that naked singularities and closed timelike curves (CTCs) are avoided. We calculate the conserved energy, angular momenta, and charge for the solutions, and show how supersymmetric solutions arise in a Bogomol'nyi-Prasad-Sommerfield limit. These have naked CTCs in general, but for special choices of the parameters we obtain new regular supersymmetric black holes or smooth topological solitons.

  13. T-546: Microsoft MHTML Input Validation Hole May Permit Cross-Site

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Scripting Attacks Arbitrary Code | Department of Energy 6: Microsoft MHTML Input Validation Hole May Permit Cross-Site Scripting Attacks Arbitrary Code T-546: Microsoft MHTML Input Validation Hole May Permit Cross-Site Scripting Attacks Arbitrary Code January 31, 2011 - 7:00am Addthis PROBLEM: Microsoft MHTML Input Validation Hole May Permit Cross-Site Scripting Attacks Arbitrary Code. PLATFORM: Microsoft 2003 SP2, Vista SP2, 2008 SP2, XP SP3, 7; and prior service packs ABSTRACT: A

  14. T-722: IBM WebSphere Commerce Edition Input Validation Holes Permit

    Energy Savers [EERE]

    Cross-Site Scripting Attacks | Department of Energy 2: IBM WebSphere Commerce Edition Input Validation Holes Permit Cross-Site Scripting Attacks T-722: IBM WebSphere Commerce Edition Input Validation Holes Permit Cross-Site Scripting Attacks September 21, 2011 - 8:15am Addthis PROBLEM: IBM WebSphere Commerce Edition Input Validation Holes Permit Cross-Site Scripting Attacks. PLATFORM: WebSphere Commerce Edition V7.0 ABSTRACT: A remote user can access the target user's cookies (including

  15. The mass of the black hole in LMC X-3

    SciTech Connect (OSTI)

    Orosz, Jerome A.; Steiner, James F.; McClintock, Jeffrey E.; Buxton, Michelle M.; Bailyn, Charles D.; Steeghs, Danny; Guberman, Alec; Torres, Manuel A. P. E-mail: jsteiner@cfa.harvard.edu E-mail: michelle.buxton@yale.edu E-mail: D.T.H.Steeghs@warwick.ac.uk E-mail: M.Torres@sron.nl

    2014-10-20

    We analyze a large set of new and archival photometric and spectroscopic observations of LMC X-3 to arrive at a self-consistent dynamical model for the system. Using echelle spectra obtained with the Magellan Inamori Kyocera Echelle instrument on the 6.5 m Magellan Clay telescope and the UVES instrument on the second 8.2 m Very Large Telescope, we find a velocity semiamplitude for the secondary star of K {sub 2} = 241.1 6.2 km s{sup 1}, where the uncertainty includes an estimate of the systematic error caused by X-ray heating. Using the spectra, we also find a projected rotational velocity of V {sub rot}sin i = 118.5 6.6 km s{sup 1}. From an analysis of archival B and V light curves as well as new B and V light curves from the SMARTS 1.3 m telescope, we find an inclination of i = 69.84 0.37 for models that do not include X-ray heating and an inclination of i = 69.24 0.72 for models that incorporate X-ray heating. Adopting the latter inclination measurement, we find masses of 3.63 0.57 M {sub ?} and 6.98 0.56 M {sub ?} for the companion star and the black hole, respectively. We briefly compare our results with earlier work and discuss some of their implications.

  16. Extraordinary optical transmission in nanopatterned ultrathin metal films without holes

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Peer, Akshit; Biswas, Rana

    2016-02-01

    In this study, we experimentally and theoretically demonstrate that a continuous gold film on a periodically textured substrate exhibits extraordinary optical transmission, even though no holes were etched in the film. Our film synthesis started by nanoimprinting a periodic array of nanocups with a period of ~750 nm on a polystyrene film over a glass substrate. A thin non-conformal gold film was sputter-deposited on the polystyrene by angle-directed deposition. The gold film was continuous with spatial thickness variation, the film being thinnest at the bottom of the nanocup. Measurements revealed an extraordinary transmission peak at a wavelength just smaller thanmore » the period, with an enhancement of ~2.5 compared to the classically expected value. Scattering matrix simulations model well the transmission and reflectance measurements when an ultrathin gold layer (~5 nm), smaller than the skin depth is retained at the bottom of the nanocups. Electric field intensities are enhanced by >100 within the nanocup, and ~40 in the ultrathin gold layer causing transmission through it. We show a wavelength red-shift of ~30 nm in the extraordinary transmission peak when the nanocups are coated with a thin film of a few nanometers, which can be utilized for biosensing. The continuous corrugated metal films are far simpler structures to observe extraordinary transmission, circumventing the difficult process of etching the metal film. Such continuous metal films with ultrathin regions are simple platforms for non-linear optics, plasmonics, and biological and chemical sensing.« less

  17. Fabrication and Characterization of a Single Hole Transistor in p-type GaAs/AlGaAs Heterostructures

    SciTech Connect (OSTI)

    Tracy, Lisa A; Reno, John L.; Hargett, Terry W.

    2015-09-01

    Most spin qubit research to date has focused on manipulating single electron spins in quantum dots. However, hole spins are predicted to have some advantages over electron spins, such as reduced coupling to host semiconductor nuclear spins and the ability to control hole spins electrically using the large spin-orbit interaction. Building on recent advances in fabricating high-mobility 2D hole systems in GaAs/AlGaAs heterostructures at Sandia, we fabricate and characterize single hole transistors in GaAs. We demonstrate p-type double quantum dot devices with few-hole occupation, which could be used to study the physics of individual hole spins and control over coupling between hole spins, looking towards eventual applications in quantum computing. Intentionally left blank

  18. Superradiance and black hole bomb in five-dimensional minimal ungauged supergravity

    SciTech Connect (OSTI)

    Aliev, Alikram N.

    2014-11-01

    We examine the black hole bomb model which consists of a rotating black hole of five-dimenensional minimal ungauged supergravity and a reflecting mirror around it. For low-frequency scalar perturbations, we find solutions to the Klein-Gordon equation in the near-horizon and far regions of the black hole spacetime. To avoid solutions with logarithmic terms, we assume that the orbital quantum number l takes on nearly, but not exactly, integer values and perform the matching of these solutions in an intermediate region. This allows us to calculate analytically the frequency spectrum of quasinormal modes, taking the limits as l approaches even or odd integers separately. We find that all l modes of scalar perturbations undergo negative damping in the regime of superradiance, resulting in exponential growth of their amplitudes. Thus, the model under consideration would exhibit the superradiant instability, eventually behaving as a black hole bomb in five dimensions.

  19. SUPER-CRITICAL GROWTH OF MASSIVE BLACK HOLES FROM STELLAR-MASS SEEDS

    SciTech Connect (OSTI)

    Madau, Piero; Haardt, Francesco; Dotti, Massimo

    2014-04-01

    We consider super-critical accretion with angular momentum onto stellar-mass black holes as a possible mechanism for growing billion-solar-mass black holes from light seeds at early times. We use the radiatively inefficient ''slim disk'' solutionadvective, optically thick flows that generalize the standard geometrically thin disk modelto show how mildly super-Eddington intermittent accretion may significantly ease the problem of assembling the first massive black holes when the universe was less than 0.8Gyr old. Because of the low radiative efficiencies of slim disks around non-rotating as well as rapidly rotating black holes, the mass e-folding timescale in this regime is nearly independent of the spin parameter. The conditions that may lead to super-critical growth in the early universe are briefly discussed.

  20. Thermodynamics of black holes in (n+1)-dimensional Einstein-Born-Infeld-dilaton gravity

    SciTech Connect (OSTI)

    Sheykhi, A.; Riazi, N.

    2007-01-15

    We construct a new class of (n+1)-dimensional (n{>=}3) black hole solutions in Einstein-Born-Infeld-dilaton gravity with Liouville-type potential for the dilaton field and investigate their properties. These solutions are neither asymptotically flat nor (anti)-de Sitter. We find that these solutions can represent black holes, with inner and outer event horizons, an extreme black hole, or a naked singularity provided the parameters of the solutions are chosen suitably. We compute the thermodynamic quantities of the black hole solutions and find that these quantities satisfy the first law of thermodynamics. We also perform a stability analysis and investigate the effect of dilaton on the stability of the solutions.

  1. Hidden symmetries, null geodesics, and photon capture in the Sen black hole

    SciTech Connect (OSTI)

    Hioki, Kenta; Miyamoto, Umpei

    2008-08-15

    Important classes of null geodesics and hidden symmetries in the Sen black hole are investigated. First, we obtain the principal null geodesics and circular photon orbits. Then, an irreducible rank-two Killing tensor and a conformal Killing tensor are derived, which represent the hidden symmetries. Analyzing the properties of Killing tensors, we clarify why the Hamilton-Jacobi and wave equations are separable in this spacetime. We also investigate the gravitational capture of photons by the Sen black hole and compare the result with those by the various charged/rotating black holes and naked singularities in the Kerr-Newman family. For these black holes and naked singularities, we show the capture regions in a two dimensional impact parameter space (or equivalently the 'shadows' observed at infinity) to form a variety of shapes such as the disk, circle, dot, arc, and their combinations.

  2. Thermodynamics of asymptotically flat charged black holes in third order Lovelock gravity

    SciTech Connect (OSTI)

    Dehghani, M.H.; Shamirzaie, M.

    2005-12-15

    We present a new class of asymptotically flat charge static solutions in third order Lovelock gravity. These solutions present black hole solutions with two inner and outer event horizons, extreme black holes, or naked singularities provided the parameters of the solutions are chosen suitable. We find that the uncharged asymptotically flat solutions can present black holes with two inner and outer horizons. This kind of solution does not exist in Einstein or Gauss-Bonnet gravity, and it is a special effect in third order Lovelock gravity. We compute temperature, entropy, charge, electric potential, and mass of the black hole solutions, and find that these quantities satisfy the first law of thermodynamics. We also perform a stability analysis by computing the determinant of the Hessian matrix of the mass with respect to its thermodynamic variables in both the canonical and the grand-canonical ensembles, and show that there exists only an intermediate stable phase.

  3. Results Of An Experimental Drill Hole At The Summit Of Kilauea...

    Open Energy Info (EERE)

    Results Of An Experimental Drill Hole At The Summit Of Kilauea Volcano, Hawaii Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Results Of An...

  4. BINARY DISRUPTION BY MASSIVE BLACK HOLES: HYPERVELOCITY STARS, S STARS, AND TIDAL DISRUPTION EVENTS

    SciTech Connect (OSTI)

    Bromley, Benjamin C.; Kenyon, Scott J.; Geller, Margaret J.; Brown, Warren R. E-mail: skenyon@cfa.harvard.edu E-mail: wbrown@cfa.harvard.edu

    2012-04-20

    We examine whether disrupted binary stars can fuel black hole growth. In this mechanism, tidal disruption produces a single hypervelocity star (HVS) ejected at high velocity and a former companion star bound to the black hole. After a cluster of bound stars forms, orbital diffusion allows the black hole to accrete stars by tidal disruption at a rate comparable to the capture rate. In the Milky Way, HVSs and the S star cluster imply similar rates of 10{sup -5} to 10{sup -3} yr{sup -1} for binary disruption. These rates are consistent with estimates for the tidal disruption rate in nearby galaxies and imply significant black hole growth from disrupted binaries on 10 Gyr timescales.

  5. A Statistical Analysis Of Bottom-Hole Temperature Data In The...

    Open Energy Info (EERE)

    Statistical Analysis Of Bottom-Hole Temperature Data In The Hinton Area Of West-Central Alberta Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article:...

  6. Physical-Property Measurements on Core Samples from Drill-Holes...

    Open Energy Info (EERE)

    Physical-Property Measurements on Core Samples from Drill-Holes DB-1 and DB-2, Blue Mountain Geothermal Prospect, North-Central Nevada Jump to: navigation, search OpenEI Reference...

  7. Effect of geometry and composition on the intraband transitions of holes in quantum dots

    SciTech Connect (OSTI)

    Singh, Satish Kumar Kumar, Jitendra

    2014-12-28

    The effect of shape and size anisotropy on unipolar intraband transitions of holes in quantum dots (QDs) is studied. The optical matrix elements are calculated for transitions of holes in valence band. To get the optical matrix elements, energy eigenvalues and eigenvectors are calculated using 4??4 Luttinger Hamiltonian in the effective mass approximation. The formulation is applied to InGaAs/GaAs QD with parabolic confinement potential in xy-plane. The optical matrix elements for intraband hole transitions are calculated for x and y polarised light. The transitions are considered from ground state to other excited states. The effect of In concentration on optical matrix elements is also investigated. It is important to note that the transitions of holes are governed by the character of initial and final states for different light polarisations that give specific transition selection rules. It is found that the polarisation is strongly dependent on the in-plane anisotropy of the QDs.

  8. Causal extraction of black hole rotational energy by various kinds of electromagnetic fields

    SciTech Connect (OSTI)

    Koide, Shinji; Baba, Tamon

    2014-09-10

    Recent general relativistic magnetohydrodynamics (MHD) simulations have suggested that relativistic jets from active galactic nuclei (AGNs) have been powered by the rotational energy of central black holes. Some mechanisms for extraction of black hole rotational energy have been proposed, like the Penrose process, Blandford-Znajek mechanism, MHD Penrose process, and superradiance. The Blandford-Znajek mechanism is the most promising mechanism for the engines of the relativistic jets from AGNs. However, an intuitive interpretation of this mechanism with causality is not yet clarified, while the Penrose process has a clear interpretation for causal energy extraction from a black hole with negative energy. In this paper, we present a formula to build physical intuition so that in the Blandford-Znajek mechanism, as well as in other electromagnetic processes, negative electromagnetic energy plays an important role in causal extraction of the rotational energy of black holes.

  9. Heat Flow From Four New Research Drill Holes In The Western Cascades...

    Open Energy Info (EERE)

    From Four New Research Drill Holes In The Western Cascades, Oregon, Usa Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Heat Flow From Four New...

  10. U.S. Average Depth of Dry Holes Developmental Wells Drilled ...

    Annual Energy Outlook [U.S. Energy Information Administration (EIA)]

    Developmental Wells Drilled (Feet per Well) U.S. Average Depth of Dry Holes Developmental Wells Drilled (Feet per Well) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 Year-6...

  11. U.S. Average Depth of Dry Holes Exploratory Wells Drilled (Feet...

    Annual Energy Outlook [U.S. Energy Information Administration (EIA)]

    Exploratory Wells Drilled (Feet per Well) U.S. Average Depth of Dry Holes Exploratory Wells Drilled (Feet per Well) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 Year-6 Year-7...

  12. Analysis of the Sultana-Dyer cosmological black hole solution of the Einstein equations

    SciTech Connect (OSTI)

    Faraoni, Valerio

    2009-08-15

    The Sultana-Dyer solution of general relativity representing a black hole embedded in a special cosmological background is analyzed. We find an expanding (weak) spacetime singularity instead of the reported conformal Killing horizon, which is covered by an expanding black hole apparent horizon (internal to a cosmological apparent horizon) for most of the history of the Universe. This singularity was naked early on. The global structure of the solution is studied as well.

  13. Groundwater Makes a Splash NNSS Groundwater Experts Meet at Devils Hole

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    May 15, 2013 Groundwater Makes a Splash NNSS Groundwater Experts Meet at Devils Hole Groundwater was a major topic at this year's Devils Hole Workshop at the Furnace Creek Ranch in Death Valley, CA, May 1-3, 2013. The annual event allows scientists working in and around Death Valley to share updates, innovations, and challenges associated with ecological study in the region. A special focus was placed on the extensive groundwater program at the Nevada National Security Site (NNSS) and

  14. Gravitational Waves from Coalescing Binary Black Holes: Theoretical and Experimental Challenges

    ScienceCinema (OSTI)

    None

    2011-10-06

    A network of ground-based interferometric gravitational wave detectors (LIGO/VIRGO/GEO/...) is currently taking data near its planned sensitivity. Coalescing black hole binaries are among the most promising, and most exciting, gravitational wave sources for these detectors. The talk will review the theoretical and experimental challenges that must be met in order to successfully detect gravitational waves from coalescing black hole binaries, and to be able to reliably measure the physical parameters of the source (masses, spins, ...).

  15. Listening to the noise: random fluctuations reveal gene network parameters

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Journal Article: Listening to the noise: random fluctuations reveal gene network parameters Citation Details In-Document Search Title: Listening to the noise: random fluctuations reveal gene network parameters The cellular environment is abuzz with noise. The origin of this noise is attributed to the inherent random motion of reacting molecules that take part in gene expression and post expression interactions. In this noisy environment, clonal populations

  16. Spin-Hall-assisted magnetic random access memory (Journal Article) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Spin-Hall-assisted magnetic random access memory Citation Details In-Document Search Title: Spin-Hall-assisted magnetic random access memory We propose a write scheme for perpendicular spin-transfer torque magnetoresistive random-access memory that significantly reduces the required tunnel current density and write energy. A sub-nanosecond in-plane polarized spin current pulse is generated using the spin-Hall effect, disturbing the stable magnetic state. Subsequent switching

  17. Linking the spin evolution of massive black holes to galaxy kinematics

    SciTech Connect (OSTI)

    Sesana, A.; Barausse, E.; Dotti, M.; Rossi, E. M. E-mail: barausse@iap.fr E-mail: emr@strw.leidenuniv.nl

    2014-10-20

    We present the results of a semianalytical model that evolves the masses and spins of massive black holes together with the properties of their host galaxies across the cosmic history. As a consistency check, our model broadly reproduces a number of observations, e.g., the cosmic star formation history; the black hole mass, luminosity, and galaxy mass functions at low redshift; the black hole-bulge mass relation; and the morphological distribution at low redshift. For the first time in a semianalytical investigation, we relax the simplifying assumptions of perfect coherency or perfect isotropy of the gas fueling the black holes. The dynamics of gas is instead linked to the morphological properties of the host galaxies, resulting in different spin distributions for black holes hosted in different galaxy types. We compare our results with the observed sample of spin measurements obtained through broad K? iron line fitting. The observational data disfavor both accretion along a fixed direction and isotropic fueling. Conversely, when the properties of the accretion flow are anchored to the kinematics of the host galaxy, we obtain a good match between theoretical expectations and observations. A mixture of coherent accretion and phases of activity in which the gas dynamics is similar to that of the stars in bulges (i.e., with a significant velocity dispersion superimposed to a net rotation) best describes the data, adding further evidence in support of the coevolution of massive black holes and their hosts.

  18. Observing the shadow of Einstein-Maxwell-Dilaton-Axion black hole

    SciTech Connect (OSTI)

    Wei, Shao-Wen; Liu, Yu-Xiao E-mail: liuyx@lzu.edu.cn

    2013-11-01

    In this paper, the shadows cast by Einstein-Maxwell-Dilaton-Axion black hole and naked singularity are studied. The shadow of a rotating black hole is found to be a dark zone covered by a deformed circle. For a fixed value of the spin a, the size of the shadow decreases with the dilaton parameter b. The distortion of the shadow monotonically increases with b and takes its maximal when the black hole approaches to the extremal case. Due to the optical properties, the area of the black hole shadow is supposed to equal to the high-energy absorption cross section. Based on this assumption, the energy emission rate is investigated. For a naked singularity, the shadow has a dark arc and a dark spot or straight, and the corresponding observables are obtained. These results show that there is a significant effect of the spin a and dilaton parameter b on these shadows. Moreover, we examine the observables of the shadow cast by the supermassive black hole at the center of the Milky Way, which is very useful for us to probe the nature of the black hole through the astronomical observations in the near future.

  19. Random-matrix approach to the statistical compound nuclear reaction...

    Office of Scientific and Technical Information (OSTI)

    nuclear reaction at low energies using the Monte-Carlo technique Citation Details In-Document Search Title: Random-matrix approach to the statistical compound nuclear ...

  20. Synthesis, Structure, and Properties of Alternating and Random...

    Office of Scientific and Technical Information (OSTI)

    Synthesis, Structure, and Properties of Alternating and Random Poly(styrene-b-butadiene) Multiblock Copolymers Citation Details In-Document Search Title: Synthesis, Structure, and...

  1. A population of relic intermediate-mass black holes in the halo of the Milky Way

    SciTech Connect (OSTI)

    Rashkov, Valery; Madau, Piero

    2014-01-10

    If 'seed' central black holes were common in the subgalactic building blocks that merged to form present-day massive galaxies, then relic intermediate-mass black holes (IMBHs) should be present in the Galactic bulge and halo. We use a particle tagging technique to dynamically populate the N-body Via Lactea II high-resolution simulation with black holes, and assess the size, properties, and detectability of the leftover population. The method assigns a black hole to the most tightly bound central particle of each subhalo at infall according to an extrapolation of the M {sub BH}-?{sub *} relation, and self-consistently follows the accretion and disruption of Milky Way progenitor dwarfs and their holes in a cosmological 'live' host from high redshift to today. We show that, depending on the minimum stellar velocity dispersion, ? {sub m}, below which central black holes are assumed to be increasingly rare, as many as ?2000 (? {sub m} = 3 km s{sup 1}) or as few as ?70 (? {sub m} = 12 km s{sup 1}) IMBHs may be left wandering in the halo of the Milky Way today. The fraction of IMBHs forced from their hosts by gravitational recoil is ? 20%. We identify two main Galactic subpopulations, 'naked' IMBHs, whose host subhalos were totally destroyed after infall, and 'clothed' IMBHs residing in dark matter satellites that survived tidal stripping. Naked IMBHs typically constitute 40%-50% of the total and are more centrally concentrated. We show that, in the ? {sub m} = 12 km s{sup 1} scenario, the clusters of tightly bound stars that should accompany naked IMBHs would be fainter than m{sub V} = 16 mag, spatially resolvable, and have proper motions of 0.1-10 mas yr{sup 1}. Their detection may provide an observational tool to constrain the formation history of massive black holes in the early universe.

  2. Refractory two-dimensional hole gas on hydrogenated diamond surface

    SciTech Connect (OSTI)

    Hiraiwa, Atsushi; Daicho, Akira; Kurihara, Shinichiro; Yokoyama, Yuki; Kawarada, Hiroshi

    2012-12-15

    Use of two-dimensional hole gas (2DHG), induced on a hydrogenated diamond surface, is a solution to overcoming one of demerits of diamond, i.e., deep energy levels of impurities. This 2DHG is affected by its environment and accordingly needs a passivation film to get a stable device operation especially at high temperature. In response to this requirement, we achieved the high-reliability passivation forming an Al{sub 2}O{sub 3} film on the diamond surface using an atomic-layer-deposition (ALD) method with an H{sub 2}O oxidant at 450 Degree-Sign C. The 2DHG thus protected survived air annealing at 550 Degree-Sign C for an hour, establishing a stable high-temperature operation of 2DHG devices in air. In part, this achievement is based on high stability of C-H bonds up to 870 Degree-Sign C in vacuum and above 450 Degree-Sign C in an H{sub 2}O-containing environment as in the ALD. Chemically, this stability is supported by the fact that both the thermal decomposition of C-H bonds and reaction between C-H bonds and H{sub 2}O are endothermic processes. It makes a stark contrast to the instability of Si-H bonds, which decompose even at room temperature being exposed to atomic hydrogen. In this respect, the diamond 2DHG devices are also promising as power devices expectedly being free from many instability phenomena, such as hot carrier effect and negative-bias temperature instability, associated with Si devices. As to adsorbate, which is the other prerequisite for 2DHG, it desorbed in vacuum below 250 Degree-Sign C, and accordingly some new adsorbates should have adsorbed during the ALD at 450 Degree-Sign C. As a clue to this question, we certainly confirmed that some adsorbates, other than those at room temperature, adsorbed in air above 100 Degree-Sign C and remained at least up to 290 Degree-Sign C. The identification of these adsorbates is open for further investigation.

  3. Random matrices and chaos in nuclear physics: Nuclear structure

    SciTech Connect (OSTI)

    Weidenmueller, H. A.; Mitchell, G. E. [Max-Planck-Institut fuer Kernphysik, D-69029 Heidelberg (Germany); North Carolina State University, Raleigh, North Carolina 27695 (United States) and Triangle Universities Nuclear Laboratory, Durham, North Carolina 27706 (United States)

    2009-04-15

    Evidence for the applicability of random-matrix theory to nuclear spectra is reviewed. In analogy to systems with few degrees of freedom, one speaks of chaos (more accurately, quantum chaos) in nuclei whenever random-matrix predictions are fulfilled. An introduction into the basic concepts of random-matrix theory is followed by a survey over the extant experimental information on spectral fluctuations, including a discussion of the violation of a symmetry or invariance property. Chaos in nuclear models is discussed for the spherical shell model, for the deformed shell model, and for the interacting boson model. Evidence for chaos also comes from random-matrix ensembles patterned after the shell model such as the embedded two-body ensemble, the two-body random ensemble, and the constrained ensembles. All this evidence points to the fact that chaos is a generic property of nuclear spectra, except for the ground-state regions of strongly deformed nuclei.

  4. Methods and apparatus of suppressing tube waves within a bore hole and seismic surveying systems incorporating same

    DOE Patents [OSTI]

    West, Phillip B.; Haefner, Daryl

    2004-08-17

    Methods and apparatus for attenuating waves in a bore hole, and seismic surveying systems incorporating the same. In one embodiment, an attenuating device includes a soft compliant bladder coupled to a pressurized gas source. A pressure regulating system reduces the pressure of the gas from the gas source prior to entering the bladder and operates in conjunction with the hydrostatic pressure of the fluid in a bore hole to maintain the pressure of the bladder at a specified pressure relative to the surrounding bore hole pressure. Once the hydrostatic pressure of the bore hole fluid exceeds that of the gas source, bore hole fluid may be admitted into a vessel of the gas source to further compress and displace the gas contained therein. In another embodiment, a water-reactive material may be used to provide gas to the bladder wherein the amount of gas generated by the water-reactive material may depend on the hydrostatic pressure of the bore hole fluid.

  5. Methods and apparatus of suppressing tube waves within a bore hole and seismic surveying systems incorporating same

    DOE Patents [OSTI]

    West, Phillip B.; Haefner, Daryl

    2005-12-13

    Methods and apparatus for attenuating waves in a bore hole, and seismic surveying systems incorporating the same. In one embodiment, an attenuating device includes a soft compliant bladder coupled to a pressurized gas source. A pressure regulating system reduces the pressure of the gas from the gas source prior to entering the bladder and operates in conjunction with the hydrostatic pressure of the fluid in a bore hole to maintain the pressure of the bladder at a specified pressure relative to the surrounding bore hole pressure. Once the hydrostatic pressure of the bore hole fluid exceeds that of the gas source, bore hole fluid may be admitted into a vessel of the gas source to further compress and displace the gas contained therein. In another embodiment, a water-reactive material may be used to provide gas to the bladder wherein the amount of gas generated by the water-reactive material may depend on the hydrostatic pressure of the bore hole fluid.

  6. Geology of the USW SD-7 drill hole Yucca Mountain, Nevada

    SciTech Connect (OSTI)

    Rautman, C.A.; Engstrom, D.A.

    1996-09-01

    The USW SD-7 drill hole is one of several holes drilled under Site Characterization Plan Study 8.3.1.4.3.1, also known as the Systematic Drilling Program, as part of the U.S. Department of Energy characterization program at Yucca Mountain, Nevada. The Yucca Mountain site has been proposed as the potential location of a repository for high-level nuclear waste. The SD-7 drill hole is located near the southern end of the potential repository area and immediately to the west of the Main Test Level drift of the Exploratory Studies Facility. The hole is not far from the junction of the Main Test Level drift and the proposed South Ramp decline. Drill hole USW SD-7 is 2675.1 ft (815.3 m) deep, and the core recovered nearly complete sections of ash-flow tuffs belonging to the lower half of the Tiva Canyon Tuff, the Pah Canyon Tuff, and the Topopah Spring Tuff, all of which are part of the Miocene Paintbrush Group. Core was recovered from much of the underlying Calico Hills Formation, and core was virtually continuous in the Prow Pass Tuff and the Bullfrog Tuff. The SD-7 drill hole penetrated the top several tens of feet into the Tram Tuff, which underlies the Prow Pass and Bullfrog Tuffs. These latter three units are all formations of the Crater Flat Group, The drill hole was collared in welded materials assigned to the crystal-poor middle nonlithophysal zone of the Tiva Canyon Tuff; approximately 280 ft (85 m) of this ash-flow sheet was penetrated by the hole. The Yucca Mountain Tuff appears to be missing from the section at the USW SD-7 location, and the Pah Canyon Tuff is only 14.5 ft thick. The Pah Canyon Tuff was not recovered in core because of drilling difficulties, suggesting that the unit is entirely nonwelded. The presence of this unit is inferred through interpretation of down-hole geophysical logs.

  7. Anomalous hole injection deterioration of organic light-emitting diodes with a manganese phthalocyanine layer

    SciTech Connect (OSTI)

    Lee, Hyunbok; Lee, Jeihyun; Yi, Yeonjin; Cho, Sang Wan; Kim, Jeong Won

    2015-01-21

    Metal phthalocyanines (MPcs) are well known as an efficient hole injection layer (HIL) in organic devices. They possess a low ionization energy, and so the low-lying highest occupied molecular orbital (HOMO) gives a small hole injection barrier from an anode in organic light-emitting diodes. However, in this study, we show that the hole injection characteristics of MPc are not only determined by the HOMO position but also significantly affected by the wave function distribution of the HOMO. We show that even with the HOMO level of a manganese phthalocyanine (MnPc) HIL located between the Fermi level of an indium tin oxide anode and the HOMO level of a N,N?-bis(1-naphthyl)-N,N?-diphenyl-1,1?-biphenyl-4,4?-diamine hole transport layer the device performance with the MnPc HIL is rather deteriorated. This anomalous hole injection deterioration is due to the contracted HOMO wave function, which leads to small intermolecular electronic coupling. The origin of this contraction is the significant contribution of the Mn d-orbital to the MnPc HOMO.

  8. Transition from adiabatic inspiral to plunge into a spinning black hole

    SciTech Connect (OSTI)

    Kesden, Michael

    2011-05-15

    A test particle of mass {mu} on a bound geodesic of a Kerr black hole of mass M>>{mu} will slowly inspiral as gravitational radiation extracts energy and angular momentum from its orbit. This inspiral can be considered adiabatic when the orbital period is much shorter than the time scale on which energy is radiated, and quasicircular when the radial velocity is much less than the azimuthal velocity. Although the inspiral always remains adiabatic provided {mu}<hole's spin changes following a test-particle merger, and can be extrapolated to help predict the mass and spin of the final black hole produced in finite-mass-ratio black-hole mergers. Our new contribution is particularly important for nearly maximally spinning black holes, as it can affect whether a merger produces a naked singularity.

  9. The role of screening of the electron-phonon interaction in relaxation of photoexcited electron-hole plasma in semiconductors

    SciTech Connect (OSTI)

    Kumekov, S. E.

    2008-08-15

    The role of screening of the interaction of the electron-hole plasma with optical phonons is analytically evaluated by the example of gallium arsenide.

  10. Geometrical and band-structure effects on phonon-limited hole mobility in rectangular cross-sectional germanium nanowires

    SciTech Connect (OSTI)

    Tanaka, H. Mori, S.; Morioka, N.; Suda, J.; Kimoto, T.

    2014-12-21

    We calculated the phonon-limited hole mobility in rectangular cross-sectional [001], [110], [111], and [112]-oriented germanium nanowires, and the hole transport characteristics were investigated. A tight-binding approximation was used for holes, and phonons were described by a valence force field model. Then, scattering probability of holes by phonons was calculated taking account of hole-phonon interaction atomistically, and the linearized Boltzmann's transport equation was solved to calculate the hole mobility at low longitudinal field. The dependence of the hole mobility on nanowire geometry was analyzed in terms of the valence band structure of germanium nanowires, and it was found that the dependence was qualitatively reproduced by considering an average effective mass and the density of states of holes. The calculation revealed that [110] germanium nanowires with large height along the [001] direction show high hole mobility. Germanium nanowires with this geometry are also expected to exhibit high electron mobility in our previous work, and thus they are promising for complementary metal-oxide-semiconductor (CMOS) applications.

  11. Violation of the first law of black hole thermodynamics in f(T) gravity

    SciTech Connect (OSTI)

    Miao, Rong-Xin; Li, Miao; Miao, Yan-Gang E-mail: mli@itp.ac.cn

    2011-11-01

    We prove that, in general, the first law of black hole thermodynamics, ?Q = T?S, is violated in f(T) gravity. As a result, it is possible that there exists entropy production, which implies that the black hole thermodynamics can be in non-equilibrium even in the static spacetime. This feature is very different from that of f(R) or that of other higher derivative gravity theories. We find that the violation of first law results from the lack of local Lorentz invariance in f(T) gravity. By investigating two examples, we note that f''(0) should be negative in order to avoid the naked singularities and superluminal motion of light. When f''(T) is small, the entropy of black holes in f(T) gravity is approximatively equal to f'(T)/4 A.

  12. Gravitational waves from the collision of tidally disrupted stars with massive black holes

    SciTech Connect (OSTI)

    East, William E.

    2014-11-10

    We use simulations of hydrodynamics coupled with full general relativity to investigate the gravitational waves produced by a star colliding with a massive black hole when the star's tidal disruption radius lies far outside of the black hole horizon. We consider both main-sequence and white-dwarf compaction stars, and nonspinning black holes, as well as those with near-extremal spin. We study the regime in between where the star can be accurately modeled by a point particle, and where tidal effects completely suppress the gravitational wave signal. We find that nonnegligible gravitational waves can be produced even when the star is strongly affected by tidal forces, as well as when it collides with large angular momentum. We discuss the implications that these results have for the potential observation of gravitational waves from these sources with future detectors.

  13. SPIN-PRECESSION: BREAKING THE BLACK HOLE-NEUTRON STAR DEGENERACY

    SciTech Connect (OSTI)

    Chatziioannou, Katerina; Cornish, Neil; Klein, Antoine; Yunes, Nicols

    2015-01-01

    Mergers of compact stellar remnants are prime targets for the LIGO/Virgo gravitational wave detectors. The gravitational wave signals from these merger events can be used to study the mass and spin distribution of stellar remnants, and provide information about black hole horizons and the material properties of neutron stars. However, it has been suggested that degeneracies in the way that the star's mass and spin are imprinted in the waveforms may make it impossible to distinguish between black holes and neutron stars. Here we show that the precession of the orbital plane due to spin-orbit coupling breaks the mass-spin degeneracy, and allows us to distinguish between standard neutron stars and alternative possibilities, such as black holes or exotic neutron stars with large masses and spins.

  14. INTEGRATED DRILLING SYSTEM USING MUD ACTUATED DOWN HOLE HAMMER AS PRIMARY ENGINE

    SciTech Connect (OSTI)

    John V. Fernandez; David S. Pixton

    2005-12-01

    A history and project summary of the development of an integrated drilling system using a mud-actuated down-hole hammer as its primary engine are given. The summary includes laboratory test results, including atmospheric tests of component parts and simulated borehole tests of the hammer system. Several remaining technical hurdles are enumerated. A brief explanation of commercialization potential is included. The primary conclusion for this work is that a mud actuated hammer can yield substantial improvements to drilling rate in overbalanced, hard rock formations. A secondary conclusion is that the down-hole mud actuated hammer can serve to provide other useful down-hole functions including generation of high pressure mud jets, generation of seismic and sonic signals, and generation of diagnostic information based on hammer velocity profiles.

  15. Multicanonical sampling of rare events in random matrices

    SciTech Connect (OSTI)

    Saito, Nen; Iba, Yukito; Hukushima, Koji

    2010-09-15

    A method based on multicanonical Monte Carlo is applied to the calculation of large deviations in the largest eigenvalue of random matrices. The method is successfully tested with the Gaussian orthogonal ensemble, sparse random matrices, and matrices whose components are subject to uniform density. Specifically, the probability that all eigenvalues of a matrix are negative is estimated in these cases down to the values of {approx}10{sup -200}, a region where simple random sampling is ineffective. The method can be applied to any ensemble of matrices and used for sampling rare events characterized by any statistics.

  16. Implications of access hole size on tank waste retrieval system design and cost

    SciTech Connect (OSTI)

    Babcock, S.M.; Kwon, D.S.; Burks, B.L.; Stoughton, R.S.; Evans, M.S.

    1994-05-01

    The DOE Environmental Restoration and Waste Management Robotics Technology Development Program has been investigating the application of robotics technology to the retrieval of waste from single-shell storage tanks for several years. The use of a large, ``long-reach`` manipulator to position and orient a variety of tools and other equipment has been recommended. The objective of this study is to determine the appropriate access hole size for the tank waste retrieval system installation. Previous reports on the impact of access hole size on manipulator performance are summarized. In addition, the practical limitation for access hole size based on structural limitations of the waste storage tanks, the state-of-the-art size limitations for the installation of new risers, the radiation safety implications of various access hole sizes, and overall system cost implications are considered. Basic conclusions include: (1) overall cost of remediation will; be dominated by the costs of the balance of plant and time required to perform the task rather than the cost of manipulator hardware or the cost of installing a riser, (2) the most desirable solution from a manipulator controls point of view is to make the manipulator as stiff as possible and have as high as possible a natural frequency, which implies a large access hole diameter, (3) beyond some diameter; simple, uniform cross-section elements become less advantageous from a weight standpoint and alternative structures should be considered, and (4) additional shielding and contamination control measures would be required for larger holes. Parametric studies summarized in this report considered 3,790,000 1 (1,000,000 gal) tanks, while initial applications are likely to be for 2,840,000 1 (750,000 gal) tanks. Therefore, the calculations should be somewhat conservative, recognizing the limitations of the specific conditions considered.

  17. Observation of the Kondo effect in a spin-3/2 hole quantum dot

    SciTech Connect (OSTI)

    Klochan, O.; Micolich, A. P.; Hamilton, A. R.; Trunov, K.; Reuter, D.; Wieck, A. D.

    2013-12-04

    We report the observation of the Kondo effect in a spin-3/2 hole quantum dot formed near pinch-off in a GaAs quantum wire. We clearly observe two distinctive hallmarks of quantum dot Kondo physics. First, the zero-bias peak in the differential conductance splits an in-plane magnetic field and the splitting is independent of gate voltage. Second, the splitting rate is twice as large as that for the lowest one-dimensional subband. We show that the Zeeman splitting of the zero-bias peak is highly anisotropic and attribute this to the strong spin-orbit interaction for holes in GaAs.

  18. Hidden conformal symmetry of rotating black holes in minimal five-dimensional gauged supergravity

    SciTech Connect (OSTI)

    Setare, M. R.; Kamali, V.

    2010-10-15

    In the present paper we show that for a low frequency limit the wave equation of a massless scalar field in the background of nonextremal charged rotating black holes in five-dimensional minimal gauged and ungauged supergravity can be written as the Casimir of an SL(2,R) symmetry. Our result shows that the entropy of the black hole is reproduced by the Cardy formula. Also the absorption cross section is consistent with the finite temperature absorption cross section for a two-dimensional conformal field theory.

  19. Next Generation Hole Injection/Transport Nano-Composites for High Efficiency OLED Development

    SciTech Connect (OSTI)

    King Wang

    2009-07-31

    The objective of this program is to use a novel nano-composite material system for the OLED anode coating/hole transport layer. The novel anode coating is intended to significantly increase not only hole injection/transport efficiency, but the device energy efficiency as well. Another goal of the Core Technologies Program is the optimization and scale-up of air-stable and cross-linkable novel HTL nano-composite materials synthesis and the development of low-cost, large-scale mist deposition processes for polymer OLED fabrication. This proposed technology holds the promise to substantially improve OLED energy efficiency and lifetime.

  20. Homogeneous versus spiral phases of hole-doped antiferromagnets: A systematic effective field theory investigation

    SciTech Connect (OSTI)

    Bruegger, C.; Kaempfer, F.; Wiese, U.-J.; Hofmann, C. P.; Pepe, M.

    2007-01-01

    Using the low-energy effective field theory for magnons and holes--the condensed matter analog of baryon chiral perturbation theory for pions and nucleons in QCD--we study different phases of doped antiferromagnets. We systematically investigate configurations of the staggered magnetization that provide a constant background field for doped holes. The most general configuration of this type is either constant itself or represents a spiral in the staggered magnetization. Depending on the values of the low-energy parameters, a homogeneous phase, a spiral phase, or an inhomogeneous phase is energetically favored. The reduction of the staggered magnetization upon doping is also investigated.

  1. Terrafore: Thermal Storage gets a "Hole in One" | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Terrafore: Thermal Storage gets a "Hole in One" Terrafore: Thermal Storage gets a "Hole in One" May 29, 2015 - 2:38pm Addthis TerraCaps provide a novel method of encapsulating molten salt for increased thermal heat storage. 10- to 15-millimeter capsules provide high heat transfer surface. A void in the capsule accommodates the expansion of salt as it melts. Image from Terrafore TerraCaps provide a novel method of encapsulating molten salt for increased thermal heat storage.

  2. EERE Success Story-Terrafore: Thermal Storage gets a "Hole in One" |

    Office of Environmental Management (EM)

    Department of Energy Terrafore: Thermal Storage gets a "Hole in One" EERE Success Story-Terrafore: Thermal Storage gets a "Hole in One" May 29, 2015 - 2:38pm Addthis TerraCaps provide a novel method of encapsulating molten salt for increased thermal heat storage. 10- to 15-millimeter capsules provide high heat transfer surface. A void in the capsule accommodates the expansion of salt as it melts. Image from Terrafore TerraCaps provide a novel method of encapsulating

  3. Random-matrix approach to the statistical compound nuclear reaction...

    Office of Scientific and Technical Information (OSTI)

    AC52-06NA25396 Resource Type: Conference Resource Relation: Conference: Random Matrix Theory, Integrable Systems, and Topology in Physics ; 2015-11-02 - 2015-11-02 ; Stony...

  4. Quasiparticle random-phase approximation with interactions from the

    Office of Scientific and Technical Information (OSTI)

    Similarity Renormalization Group (Journal Article) | SciTech Connect Quasiparticle random-phase approximation with interactions from the Similarity Renormalization Group Citation Details In-Document Search Title: Quasiparticle random-phase approximation with interactions from the Similarity Renormalization Group Authors: Hergert, H. ; Papakonstantinou, P. ; Roth, R. Publication Date: 2011-06-16 OSTI Identifier: 1099608 Type: Publisher's Accepted Manuscript Journal Name: Physical Review C

  5. Listening to the noise: random fluctuations reveal gene network parameters

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Journal Article: Listening to the noise: random fluctuations reveal gene network parameters Citation Details In-Document Search Title: Listening to the noise: random fluctuations reveal gene network parameters × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional

  6. Hole Trapping at Surfaces of m?ZrO2 and m?HfO2 Nanocrystals

    SciTech Connect (OSTI)

    Wolf, Matthew J.; Mckenna, Keith P.; Shlyuger, Alexander L.

    2012-12-03

    We investigate hole trapping at the most prevalent facets of monoclinic zirconia (m-ZrO2) and hafnia (m-HfO2) nanocrystals using first-principles methods. The localization of holes at surface oxygen ions is more favorable than in the bulk crystal by up to ?1 eV. This is caused mainly by the reduction of the absolute value of the electrostatic potential at the surface ions with respect to the bulk and by the significant surface distortion caused by the hole localization. The mobility of holes at surfaces is much lower than that found in the bulk and is fairly isotropic. Unlike in cubic oxides, such as MgO and CaO, we do not find a significant driving force for preferential trapping of holes at steps on the m-ZrO2 surface. These fundamental results are relevant to mechanisms of water oxidation, photocatalysis, contact charging, and photodesorption.

  7. Exchange-correlation energy from pairing matrix fluctuation and the particle-particle random phase approximation

    SciTech Connect (OSTI)

    Aggelen, Helen van; Department of Chemistry, Duke University, Durham, North Carolina 27708 ; Yang, Yang; Yang, Weitao

    2014-05-14

    Despite their unmatched success for many applications, commonly used local, semi-local, and hybrid density functionals still face challenges when it comes to describing long-range interactions, static correlation, and electron delocalization. Density functionals of both the occupied and virtual orbitals are able to address these problems. The particle-hole (ph-) Random Phase Approximation (RPA), a functional of occupied and virtual orbitals, has recently known a revival within the density functional theory community. Following up on an idea introduced in our recent communication [H. van Aggelen, Y. Yang, and W. Yang, Phys. Rev. A 88, 030501 (2013)], we formulate more general adiabatic connections for the correlation energy in terms of pairing matrix fluctuations described by the particle-particle (pp-) propagator. With numerical examples of the pp-RPA, the lowest-order approximation to the pp-propagator, we illustrate the potential of density functional approximations based on pairing matrix fluctuations. The pp-RPA is size-extensive, self-interaction free, fully anti-symmetric, describes the strong static correlation limit in H{sub 2}, and eliminates delocalization errors in H{sub 2}{sup +} and other single-bond systems. It gives surprisingly good non-bonded interaction energies competitive with the ph-RPA with the correct R{sup ?6} asymptotic decay as a function of the separation R, which we argue is mainly attributable to its correct second-order energy term. While the pp-RPA tends to underestimate absolute correlation energies, it gives good relative energies: much better atomization energies than the ph-RPA, as it has no tendency to underbind, and reaction energies of similar quality. The adiabatic connection in terms of pairing matrix fluctuation paves the way for promising new density functional approximations.

  8. Geology of the USW SD-12 drill hole Yucca Mountain, Nevada

    SciTech Connect (OSTI)

    Rautman, C.A.; Engstrom, D.A.

    1996-11-01

    Drill hole USW SD-12 is one of several holes drilled under Site Characterization Plan Study 8.3.1.4.3.1, also known as the {open_quotes}Systematic Drilling Program,{close_quotes} as part of the U.S. Department of Energy characterization program at Yucca Mountain, Nevada, which has been proposed as the potential location of a repository for high-level nuclear waste. The SD-12 drill hole is located in the central part of the potential repository area, immediately to the west of the Main Test Level drift of the Exploratory Studies Facility and slightly south of midway between the North Ramp and planned South Ramp declines. Drill hole USW SD-12 is 2166.3 ft (660.26 m) deep, and the core recovered essentially complete sections of ash-flow tuffs belonging to the lower half of the Tiva Canyon Tuff, the Pah Canyon Tuff, and the Topopah Spring Tuff, all of which are part of the Miocene Paintbrush Group. A virtually complete section of the Calico Hills Formation was also recovered, as was core from the entire Prow Pass Tuff formation of the Crater Flat Group.

  9. Cold black holes in the Harlow–Hayden approach to firewalls

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ong, Yen Chin; McInnes, Brett; Chen, Pisin

    2014-12-31

    Firewalls are controversial principally because they seem to imply departures from general relativistic expectations in regions of spacetime where the curvature need not be particularly large. One of the virtues of the Harlow–Hayden approach to the firewall paradox, concerning the time available for decoding of Hawking radiation emanating from charged AdS black holes, is precisely that it operates in the context of cold black holes, which are not strongly curved outside the event horizon. Here we clarify this point. The approach is based on ideas borrowed from applications of the AdS/CFT correspondence to the quark–gluon plasma. Firewalls aside, our workmore » presents a detailed analysis of the thermodynamics and evolution of evaporating charged AdS black holes with flat event horizons. We show that, in one way or another, these black holes are always eventually destroyed in a time which, while long by normal standards, is short relative to the decoding time of Hawking radiation.« less

  10. Overspinning a nearly extreme black hole and the weak cosmic censorship conjecture

    SciTech Connect (OSTI)

    Richartz, Mauricio; Saa, Alberto

    2008-10-15

    We revisit here the recent proposal for overspinning a nearly extreme black hole by means of a quantum tunneling process. We show that electrically neutral massless fermions evade possible backreaction effects related to superradiance, confirming the view that it would be indeed possible to form a naked singularity due to quantum effects.

  11. Time delay and magnification centroid due to gravitational lensing by black holes and naked singularities

    SciTech Connect (OSTI)

    Virbhadra, K. S.; Keeton, C. R.

    2008-06-15

    We model the massive dark object at the center of the Galaxy as a Schwarzschild black hole as well as Janis-Newman-Winicour naked singularities, characterized by the mass and scalar charge parameters, and study gravitational lensing (particularly time delay, magnification centroid, and total magnification) by them. We find that the lensing features are qualitatively similar (though quantitatively different) for Schwarzschild black holes, weakly naked, and marginally strongly naked singularities. However, the lensing characteristics of strongly naked singularities are qualitatively very different from those due to Schwarzschild black holes. The images produced by Schwarzschild black hole lenses and weakly naked and marginally strongly naked singularity lenses always have positive time delays. On the other hand, strongly naked singularity lenses can give rise to images with positive, zero, or negative time delays. In particular, for a large angular source position the direct image (the outermost image on the same side as the source) due to strongly naked singularity lensing always has a negative time delay. We also found that the scalar field decreases the time delay and increases the total magnification of images; this result could have important implications for cosmology. As the Janis-Newman-Winicour metric also describes the exterior gravitational field of a scalar star, naked singularities as well as scalar star lenses, if these exist in nature, will serve as more efficient cosmic telescopes than regular gravitational lenses.

  12. Black holes in an asymptotically safe gravity theory with higher derivatives

    SciTech Connect (OSTI)

    Cai, Yi-Fu; Easson, Damien A. E-mail: easson@asu.edu

    2010-09-01

    We present a class of spherically symmetric vacuum solutions to an asymptotically safe theory of gravity containing high-derivative terms. We find quantum corrected Schwarzschild-(anti)-de Sitter solutions with running gravitational coupling parameters. The evolution of the couplings is determined by their corresponding renormalization group flow equations. These black holes exhibit properties of a classical Schwarzschild solution at large length scales. At the center, the metric factor remains smooth but the curvature singularity, while softened by the quantum corrections, persists. The solutions have an outer event horizon and an inner Cauchy horizon which equate when the physical mass decreases to a critical value. Super-extremal solutions with masses below the critical value correspond to naked singularities. The Hawking temperature of the black hole vanishes when the physical mass reaches the critical value. Hence, the black holes in the asymptotically safe gravitational theory never completely evaporate. For appropriate values of the parameters such stable black hole remnants make excellent dark matter candidates.

  13. Entropy of near-extremal black holes in AdS5

    SciTech Connect (OSTI)

    Simon, Joan; Balasubramanian, Vijay; de Boer, Jan; Jejjala, Vishnu; Simon, Joan

    2007-07-24

    We construct the microstates of near-extremal black holes in AdS_5 x S5 as gases of defects distributed in heavy BPS operators in the dual SU(N) Yang-Mills theory. These defects describe open strings on spherical D3-branes in the S5, and we show that they dominate the entropy by directly enumerating them and comparing the results with a partition sum calculation. We display new decoupling limits in which the field theory of the lightest open strings on the D-branes becomes dual to a near-horizon region of the black hole geometry. In the single-charge black hole we find evidence for an infrared duality between SU(N) Yang-Mills theories that exchanges the rank of the gauge group with an R-charge. In the two-charge case (where pairs of branes intersect on a line), the decoupled geometry includes an AdS_3 factor with a two-dimensional CFT dual. The degeneracy in this CFT accounts for the black hole entropy. In the three-charge case (where triples of branes intersect at a point), the decoupled geometry contains an AdS_2 factor. Below a certain critical mass, the two-charge system displays solutions with naked timelike singularities even though they do not violate a BPS bound. We suggest a string theoretic resolution of these singularities.

  14. Summation over histories for a particle in spherical orbit around a black hole

    SciTech Connect (OSTI)

    Bernido, C.C.; Aguarte, G.

    1997-08-01

    An exact path integral treatment of a relativistic scalar particle in a spherical orbit around a Reissner-Nordstr{umlt o}m and Schwarzschild black hole is presented. A closed form for the Green function and the energy spectrum are obtained. {copyright} {ital 1997} {ital The American Physical Society}

  15. Hole-transport material variation in fully vacuum deposited perovskite solar cells

    SciTech Connect (OSTI)

    Polander, Lauren E.; Pahner, Paul; Schwarze, Martin; Saalfrank, Matthias; Koerner, Christian; Leo, Karl

    2014-08-01

    This work addresses the effect of energy level alignment between the hole-transporting material and the active layer in vacuum deposited, planar-heterojunction CH{sub 3}NH{sub 3}PbI{sub x?3}Cl{sub x} perovskite solar cells. Through a series of hole-transport materials, with conductivity values set using controlled p-doping of the layer, we correlate their ionization potentials with the open-circuit voltage of the device. With ionization potentials beyond 5.3 eV, a substantial decrease in both current density and voltage is observed, which highlights the delicate energetic balance between driving force for hole-extraction and maximizing the photovoltage. In contrast, when an optimal ionization potential match is found, the open-circuit voltage can be maximized, leading to power conversion efficiencies of up to 10.9%. These values are obtained with hole-transport materials that differ from the commonly used Spiro-MeO-TAD and correspond to a 40% performance increase versus this reference.

  16. Cold black holes in the HarlowHayden approach to firewalls

    SciTech Connect (OSTI)

    Ong, Yen Chin; McInnes, Brett; Chen, Pisin

    2014-12-31

    Firewalls are controversial principally because they seem to imply departures from general relativistic expectations in regions of spacetime where the curvature need not be particularly large. One of the virtues of the HarlowHayden approach to the firewall paradox, concerning the time available for decoding of Hawking radiation emanating from charged AdS black holes, is precisely that it operates in the context of cold black holes, which are not strongly curved outside the event horizon. Here we clarify this point. The approach is based on ideas borrowed from applications of the AdS/CFT correspondence to the quarkgluon plasma. Firewalls aside, our work presents a detailed analysis of the thermodynamics and evolution of evaporating charged AdS black holes with flat event horizons. We show that, in one way or another, these black holes are always eventually destroyed in a time which, while long by normal standards, is short relative to the decoding time of Hawking radiation.

  17. An analysis of weep holes as a product detection device for underground compensated LPG storage systems

    SciTech Connect (OSTI)

    Sarica, C.; Demir, H.M.; Brill, J.P.

    1996-09-01

    Weep holes have been used widely to detect the presence of Liquefied Petroleum Gases (LPG) in brine for underground compensated storage systems. When the brine level drops below the weep hole, LPG product enters the brine production system causing an increase in both tubing head pressure and flow rate. To prevent cavern overfill, a cavern shutdown is initiated upon detection of LPG in the surface brine system by pressure or flow instruments at the tubing head. In this study, we have investigated the multiphase flow characteristics of weep hole LPG detection systems to correctly estimate the operating limits. A simple and easy to use model has been developed to predict the tubing head pressure and flow rate increases. The model can be used to implement safer and more efficient operation procedures for underground compensated LPG storage systems. The model predictions for a typical field case are presented. An analysis of weep holes as product detection devices for LPG storage reservoirs has been carried out. It was found that the increases in pressure and flow rates at the tubing head change as a function of injection flow rate of the product. Therefore, a thorough consideration of cavern operating parameters is necessary to evaluate the use constant pressure and flow rate values to initiate emergency shut down of the cavern.

  18. Application of spectral hole burning to the study of in vitro cellular systems

    SciTech Connect (OSTI)

    Milanovich, Nebojsa

    1999-11-08

    Chapter 1 of this thesis describes the various stages of tumor development and a multitude of diagnostic techniques used to detect cancer. Chapter 2 gives an overview of the aspects of hole burning spectroscopy important for its application to the study of cellular systems. Chapter 3 gives general descriptions of cellular organelles, structures, and physical properties that can serve as possible markers for the differentiation of normal and cancerous cells. Also described in Chapter 3 are the principles of cryobiology important for low temperature spectroscopy of cells, characterization of MCF-10F (normal) and MCF-7 (cancer) cells lines which will serve as model systems, and cellular characteristics of aluminum phthalocyanine tetrasulfonate (APT), which was used as the test probe. Chapters 4 and 5 are previously published papers by the author pertaining to the results obtained from the application of hole burning to the study of cellular systems. Chapter 4 presents the first results obtained by spectral hole burning of cellular systems and Chapter 5 gives results for the differentiation of MCF-10F and MCF-7 cells stained with APT by an external applied electric (Stark) field. A general conclusion is presented in Chapter 6. Appendices A and B provide additional characterization of the cell/probe model systems. Appendix A describes the uptake and subcellular distribution of APT in MCF-10F and MCF-7 cells and Appendix B compares the hole burning characteristics of APT in cells when the cells are in suspension and when they are examined while adhering to a glass coverslip. Appendix C presents preliminary results for a novel probe molecule, referred to as a molecular thumbtack, designed by the authors for use in future hole burning applications to cellular systems.

  19. T-693: Symantec Endpoint Protection Manager Input Validation Hole Permits Cross-Site Scripting and Cross-Site Request Forgery Attacks

    Broader source: Energy.gov [DOE]

    Symantec Endpoint Protection Manager Input Validation Hole Permits Cross-Site Scripting and Cross-Site Request Forgery Attacks .

  20. Beowawe geothermal-resource assessment. Final report. Shallow-hole temperature survey geophysics and deep test hole Collins 76-17

    SciTech Connect (OSTI)

    Jones, N.O.

    1983-03-01

    Geothermal resource investigation field efforts in the Beowawe Geysers Area, Eureka County, Nevada are described. The objectives included acquisition of geotechnical data for understanding the nature and extent of the geothermal resource boundaries south of the known resource area. Fourteen shallow (<500 feet) temperature-gradient holes plus geophysics were used to select the site for a deep exploratory well, the Collins 76-17, which was completed to a total depth of 9005 feet. Maximum downhole recorded temperature was 311/sup 0/F, but no flow could be induced.

  1. The deterministic chaos and random noise in turbulent jet

    SciTech Connect (OSTI)

    Yao, Tian-Liang; Liu, Hai-Feng Xu, Jian-Liang; Li, Wei-Feng

    2014-06-01

    A turbulent flow is usually treated as a superposition of coherent structure and incoherent turbulence. In this paper, the largest Lyapunov exponent and the random noise in the near field of round jet and plane jet are estimated with our previously proposed method of chaotic time series analysis [T. L. Yao, et al., Chaos 22, 033102 (2012)]. The results show that the largest Lyapunov exponents of the round jet and plane jet are in direct proportion to the reciprocal of the integral time scale of turbulence, which is in accordance with the results of the dimensional analysis, and the proportionality coefficients are equal. In addition, the random noise of the round jet and plane jet has the same linear relation with the Kolmogorov velocity scale of turbulence. As a result, the random noise may well be from the incoherent disturbance in turbulence, and the coherent structure in turbulence may well follow the rule of chaotic motion.

  2. Random telegraph noise in metallic single-walled carbon nanotubes

    SciTech Connect (OSTI)

    Chung, Hyun-Jong; Woo Uhm, Tae; Won Kim, Sung; Gyu You, Young; Wook Lee, Sang; Ho Jhang, Sung; Campbell, Eleanor E. B.; Woo Park, Yung

    2014-05-12

    We have investigated random telegraph noise (RTN) observed in individual metallic carbon nanotubes (CNTs). Mean lifetimes in high- and low-current states, ?{sub high} and ?{sub low}, have been studied as a function of bias-voltage and gate-voltage as well as temperature. By analyzing the statistics and features of the RTN, we suggest that this noise is due to the random transition of defects between two metastable states, activated by inelastic scattering with conduction electrons. Our results indicate an important role of defect motions in the 1/f noise in CNTs.

  3. Doped hole transport layer for efficiency enhancement in planar heterojunction organolead trihalide perovskite solar cells

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wang, Qi; Bi, Cheng; Huang, Jinsong

    2015-05-06

    We demonstrated the efficiency of a solution-processed planar heterojunction organometallic trihalide perovskite solar cell can be increased to 17.5% through doping the hole transporting layer for reducing the resistivity. Doped Poly(triaryl amine) (PTAA) by 2,3,5,6-Tetrafluoro-7,7,8,8-Tetracyanoquinodimethane (F4-TCNQ) reduced device series resistance by three-folds, increasing the device fill factor to 74%, open circuit voltage to 1.09 V without sacrificing the short circuit current. As a result, this study reveals that the high resistivity of currently broadly applied polymer hole transport layer limits the device efficiency, and points a new direction to improve the device efficiency.

  4. Null geodesics and shadow of a rotating black hole in extended Chern-Simons modified gravity

    SciTech Connect (OSTI)

    Amarilla, Leonardo; Eiroa, Ernesto F.; Giribet, Gaston

    2010-06-15

    The Chern-Simons modification to general relativity in four dimensions consists of adding to the Einstein-Hilbert term a scalar field that couples to the first-class Pontryagin density. In this theory, which has attracted considerable attention recently, the Schwarzschild metric persists as an exact solution, and this is why this model resists several observational constraints. In contrast, the spinning black hole solution of the theory is not given by the Kerr metric but by a modification of it, so far only known for slow rotation and small coupling constant. In the present paper, we show that, in this approximation, the null geodesic equation can be integrated, and this allows us to investigate the shadow cast by a black hole. We discuss how, in addition to the angular momentum of the solution, the coupling to the Chern-Simons term deforms the shape of the shadow.

  5. Comparative analysis of hole transport in compressively strained InSb and Ge quantum well heterostructures

    SciTech Connect (OSTI)

    Agrawal, Ashish; Barth, Michael; Madan, Himanshu; Datta, Suman; Lee, Yi-Jing; Lin, You-Ru; Wu, Cheng-Hsien; Ko, Chih-Hsin; Wann, Clement H.; Loubychev, Dmitri; Liu, Amy; Fastenau, Joel; Lindemuth, Jeff

    2014-08-04

    Compressively strained InSb (s-InSb) and Ge (s-Ge) quantum well heterostructures are experimentally studied, with emphasis on understanding and comparing hole transport in these two-dimensional confined heterostructures. Magnetotransport measurements and bandstructure calculations indicate 2.5 lower effective mass for s-InSb compared to s-Ge quantum well at 1.9??10{sup 12}?cm{sup 2}. Advantage of strain-induced m* reduction is negated by higher phonon scattering, degrading hole transport at room temperature in s-InSb quantum well compared to s-Ge heterostructure. Consequently, effective injection velocity is superior in s-Ge compared to s-InSb. These results suggest s-Ge quantum well heterostructure is more favorable and promising p-channel candidate compared to s-InSb for future technology node.

  6. A study of the ignition processes in a center-hole-fired thermal battery

    SciTech Connect (OSTI)

    Guidotti, R.A.; Reinhardt, F.W.

    1998-04-01

    The ignition processes that take place during activation of a 16 cell, center hole fired thermal battery were examined by monitoring the voltage of each cell during activation. The average rise time of each cell to a voltage of 1.125 V was determined for the LiSi/LiCl-LiBr-LiF/FeS{sub 2} electrochemical system. The effects of heat pellet composition, center hole diameter, and the load on the activation parameters were examined for three different igniters. A large variability in individual cell performance was evident along with cell reversal, depending on the location of the cell in the stack. It was not possible to draw detailed statistical information of the relative ignition sequence due to the intrinsic large scatter in the data.

  7. Charged annular disks and Reissner-Nordstroem type black holes from extremal dust

    SciTech Connect (OSTI)

    Lora-Clavijo, F. D.; Ospina-Henao, P. A.; Pedraza, J. F.

    2010-10-15

    We present the first analytical superposition of a charged black hole with an annular disk of extremal dust. In order to obtain the solutions, we first solve the Einstein-Maxwell field equations for sources that represent disklike configurations of matter in confomastatic spacetimes by assuming a functional dependence among the metric function, the electric potential, and an auxiliary function, which is taken as a solution of the Laplace equation. We then employ the Lord Kelvin inversion method applied to models of finite extension in order to obtain annular disks. The structures obtained extend to infinity, but their total masses are finite and all the energy conditions are satisfied. Finally, we observe that the extremal Reissner-Nordstroem black hole can be embedded into the center of the disks by adding a boundary term in the inversion.

  8. Temperature sensibility of the birefringence properties in side-hole photonic crystal fiber filled with Indium

    SciTech Connect (OSTI)

    Reyes-Vera, Erick Gmez-Cardona, Nelson D.; Chesini, Giancarlo; Cordeiro, Cristiano M. B.; Torres, Pedro

    2014-11-17

    We report on the temperature sensitivity of the birefringence properties of a special kind of photonic crystal fiber containing two side holes filled with Indium metal. The modulation of the fiber birefringence is accomplished through the stress field induced by the expansion of the metal. Although the fiber was made at low gas pressures during the indium infiltration process, the birefringence showed anomalous property at a relatively low temperature value, which is completely different from those reported in conventional-like fibers with two holes filled with metal. By modeling the anisotropic changes induced by the metal expansion to the refractive index within the fiber, we are able to reproduce the experimental results. Our results have practical relevance for the design of devices based on this technology.

  9. Using a Semiconductor-to-Metal Transition to Control Optical Transmission through Subwavelength Hole Arrays

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Donev, E. U.; Suh, J. Y.; Lopez, R.; Feldman, L. C.; Haglund, R. F.

    2008-01-01

    We describe a simple configuration in which the extraordinary optical transmission effect through subwavelength hole arrays in noble-metal films can be switched by the semiconductor-to-metal transition in an underlying thin film of vanadium dioxide. In these experiments, the transition is brought about by thermal heating of the bilayer film. The surprising reverse hysteretic behavior of the transmission through the subwavelength holes in the vanadium oxide suggest that this modulation is accomplished by a dielectric-matching condition rather than plasmon coupling through the bilayer film. The results of this switching, including the wavelength dependence, are qualitatively reproduced by a transfer matrix model.more » The prospects for effecting a similar modulation on a much faster time scale by using ultrafast laser pulses to trigger the semiconductor-to-metal transition are also discussed.« less

  10. Plasmonic waves of a semi-infinite random nanocomposite

    SciTech Connect (OSTI)

    Moradi, Afshin

    2013-10-15

    The dispersion curves of the plasmonic waves of a semi-infinite random metal-dielectric nanocomposite, consisting of bulk metal embedded with dielectric inclusions, are presented. Two branches of p-polarized surface plasmon-polariton modes are found to exist. The possibility of experimentally observing the surface waves by attenuated total reflection is demonstrated.

  11. String loops in the field of braneworld spherically symmetric black holes and naked singularities

    SciTech Connect (OSTI)

    Stuchlk, Z.; Kolo, M. E-mail: martin.kolos@fpf.slu.cz

    2012-10-01

    We study motion of current-carrying string loops in the field of braneworld spherically symmetric black holes and naked singularities. The spacetime is described by the Reissner-Nordstrm geometry with tidal charge b reflecting the non-local tidal effects coming from the external dimension; both positive and negative values of the spacetime parameter b are considered. We restrict attention to the axisymmetric motion of string loops when the motion can be fully governed by an appropriately defined effective potential related to the energy and angular momentum of the string loops. In dependence on these two constants of the motion, the string loops can be captured, trapped, or can escape to infinity. In close vicinity of stable equilibrium points at the centre of trapped states the motion is regular. We describe how it is transformed to chaotic motion with growing energy of the string loop. In the field of naked singularities the trapped states located off the equatorial plane of the system exist and trajectories unable to cross the equatorial plane occur, contrary to the trajectories in the field of black holes where crossing the equatorial plane is always admitted. We concentrate our attention to the so called transmutation effect when the string loops are accelerated in the deep gravitational field near the black hole or naked singularity by transforming the oscillatory energy to the energy of the transitional motion. We demonstrate that the influence of the tidal charge can be substantial especially in the naked singularity spacetimes with b > 1 where the acceleration to ultrarelativistic velocities with Lorentz factor ? ? 100 can be reached, being more than one order higher in comparison with those obtained in the black hole spacetimes.

  12. THE TIDAL DISRUPTION OF GIANT STARS AND THEIR CONTRIBUTION TO THE FLARING SUPERMASSIVE BLACK HOLE POPULATION

    SciTech Connect (OSTI)

    MacLeod, Morgan; Guillochon, James; Ramirez-Ruiz, Enrico E-mail: jfg@ucolick.org

    2012-10-01

    Sun-like stars are thought to be regularly disrupted by supermassive black holes (SMBHs) within galactic nuclei. Yet, as stars evolve off the main sequence their vulnerability to tidal disruption increases drastically as they develop a bifurcated structure consisting of a dense core and a tenuous envelope. Here we present the first hydrodynamic simulations of the tidal disruption of giant stars and show that the core has a substantial influence on the star's ability to survive the encounter. Stars with more massive cores retain large fractions of their envelope mass, even in deep encounters. Accretion flares resulting from the disruption of giant stars should last for tens to hundreds of years. Their characteristic signature in transient searches would not be the t {sup -5/3} decay typically associated with tidal disruption events, but a correlated rise over many orders of magnitude in brightness on timescales of months to years. We calculate the relative disruption rates of stars of varying evolutionary stages in typical galactic centers, then use our results to produce Monte Carlo realizations of the expected flaring event populations. We find that the demographics of tidal disruption flares are strongly dependent on both stellar and black hole mass, especially near the limiting SMBH mass scale of {approx}10{sup 8} M{sub Sun }. At this black hole mass, we predict a sharp transition in the SMBH flaring diet beyond which all observable disruptions arise from evolved stars, accompanied by a dramatic cutoff in the overall tidal disruption flaring rate. Black holes less massive than this limiting mass scale will show observable flares from both main-sequence and evolved stars, with giants contributing up to 10% of the event rate. The relative fractions of stars disrupted at different evolutionary states can constrain the properties and distributions of stars in galactic nuclei other than our own.

  13. Hole in one: Technicians smoothly install the center stack in the NSTX-U

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    vacuum vessel | Princeton Plasma Physics Lab Hole in one: Technicians smoothly install the center stack in the NSTX-U vacuum vessel By John Greenwald November 10, 2014 Tweet Widget Google Plus One Share on Facebook Closeup of the center stack being lowered into position by an overhead crane. (Photo by Elle Starkman/PPPL Office of Communications) Closeup of the center stack being lowered into position by an overhead crane. Gallery: Technicians guide the unit into place. (Photo by Elle

  14. Megaparsec relativistic jets launched from an accreting supermassive black hole in an extreme spiral galaxy

    SciTech Connect (OSTI)

    Bagchi, Joydeep; Vivek, M.; Srianand, Raghunathan; Gopal-Krishna; Vikram, Vinu; Hota, Ananda; Biju, K. G.; Sirothia, S. K.; Jacob, Joe

    2014-06-20

    The radio galaxy phenomenon is directly connected to mass-accreting, spinning supermassive black holes found in the active galactic nuclei. It is still unclear how the collimated jets of relativistic plasma on hundreds to thousands of kiloparsec scales form and why they are nearly always launched from the nuclei of bulge-dominated elliptical galaxies and not flat spirals. Here we present the discovery of the giant radio source J23450449 (z = 0.0755), a clear and extremely rare counterexample where relativistic jets are ejected from a luminous and massive spiral galaxy on a scale of ?1.6 Mpc, the largest known so far. Extreme physical properties observed for this bulgeless spiral host, such as its high optical and infrared luminosity, large dynamical mass, rapid disk rotation, and episodic jet activity, are possibly the results of its unusual formation history, which has also assembled, via gas accretion from a disk, its central black hole of mass >2 10{sup 8} M {sub ?}. The very high mid-IR luminosity of the galaxy suggests that it is actively forming stars and still building a massive disk. We argue that the launch of these powerful jets is facilitated by an advection-dominated, magnetized accretion flow at a low Eddington rate onto this unusually massive (for a bulgeless disk galaxy) and possibly fast spinning central black hole. Therefore, J23450449 is an extremely rare, unusual galactic system whose properties challenge the standard paradigms for black hole growth and the formation of relativistic jets in disk galaxies. Thus, it provides fundamental insight into accretion disk-relativistic jet coupling processes.

  15. Metamaterial-based theoretical description of light scattering by metallic nano-hole array structures

    SciTech Connect (OSTI)

    Singh, Mahi R.; Najiminaini, Mohamadreza; Carson, Jeffrey J. L.; Balakrishnan, Shankar

    2015-05-14

    We have experimentally and theoretically investigated the light-matter interaction in metallic nano-hole array structures. The scattering cross section spectrum was measured for three samples each having a unique nano-hole array radius and periodicity. Each measured spectrum had several peaks due to surface plasmon polaritons. The dispersion relation and the effective dielectric constant of the structure were calculated using transmission line theory and Bloch's theorem. Using the effective dielectric constant and the transfer matrix method, the surface plasmon polariton energies were calculated and found to be quantized. Using these quantized energies, a Hamiltonian for the surface plasmon polaritons was written in the second quantized form. Working with the Hamiltonian, a theory of scattering cross section was developed based on the quantum scattering theory and Green's function method. For both theory and experiment, the location of the surface plasmon polariton spectral peaks was dependant on the array periodicity and radii of the nano-holes. Good agreement was observed between the experimental and theoretical results. It is proposed that the newly developed theory can be used to facilitate optimization of nanosensors for medical and engineering applications.

  16. Super massive black hole in galactic nuclei with tidal disruption of stars

    SciTech Connect (OSTI)

    Zhong, Shiyan; Berczik, Peter; Spurzem, Rainer

    2014-09-10

    Tidal disruption of stars by super massive central black holes from dense star clusters is modeled by high-accuracy direct N-body simulation. The time evolution of the stellar tidal disruption rate, the effect of tidal disruption on the stellar density profile, and, for the first time, the detailed origin of tidally disrupted stars are carefully examined and compared with classic papers in the field. Up to 128k particles are used in simulation to model the star cluster around a super massive black hole, and we use the particle number and the tidal radius of the black hole as free parameters for a scaling analysis. The transition from full to empty loss-cone is analyzed in our data, and the tidal disruption rate scales with the particle number, N, in the expected way for both cases. For the first time in numerical simulations (under certain conditions) we can support the concept of a critical radius of Frank and Rees, which claims that most stars are tidally accreted on highly eccentric orbits originating from regions far outside the tidal radius. Due to the consumption of stars moving on radial orbits, a velocity anisotropy is found inside the cluster. Finally we estimate the real galactic center based on our simulation results and the scaling analysis.

  17. The mass of the central black hole in the nearby Seyfert galaxy NGC 5273

    SciTech Connect (OSTI)

    Bentz, Misty C.; Horenstein, Daniel; Bazhaw, Craig; Manne-Nicholas, Emily R.; Ou-Yang, Benjamin J.; Anderson, Matthew; Jones, Jeremy; Norris, Ryan P.; Parks, J. Robert; Saylor, Dicy; Teems, Katherine G.; Turner, Clay

    2014-11-20

    We present the results of a reverberation-mapping program targeting NGC 5273, a nearby early-type galaxy with a broad-lined active galactic nucleus (AGN). Over the course of the monitoring program, NGC 5273 showed strong variability that allowed us to measure time delays in the responses of the broad optical recombination lines to changes in the continuum flux. A weighted average of these measurements results in a black hole mass determination of M {sub BH} = (4.7 1.6) 10{sup 6} M {sub ?}. An estimate of the size of the black hole sphere of influence in NGC 5273 puts it just at the limit of the resolution achievable with current ground-based large aperture telescopes. NGC 5273 is therefore an important future target for a black hole mass determination from stellar dynamical modeling, especially because it is the only nearby early-type galaxy hosting an AGN with a reverberation-based mass, allowing the best comparison for the masses determined from these two techniques.

  18. THE BLACK HOLE MASS-GALAXY LUMINOSITY RELATIONSHIP FOR SLOAN DIGITAL SKY SURVEY QUASARS

    SciTech Connect (OSTI)

    Salviander, S.; Shields, G. A.; Bonning, E. W. E-mail: shields@astro.as.utexas.edu

    2015-02-01

    We investigate the relationship between the mass of the central supermassive black hole, M {sub BH}, and the host galaxy luminosity, L {sub gal}, in a sample of quasars from the Sloan Digital Sky Survey Data Release 7. We use composite quasar spectra binned by black hole mass and redshift to assess galaxy features that would otherwise be overwhelmed by noise in individual spectra. The black hole mass is calculated using the photoionization method, and the host galaxy luminosity is inferred from the depth of the Ca II H+K features in the composite spectra. We evaluate the evolution in the M {sub BH}-L {sub gal} relationship by examining the redshift dependence of ? log M {sub BH}, the offset in M {sub BH} from the local M {sub BH}-L {sub gal} relationship. There is little systematic trend in ? log M {sub BH} out to z = 0.8. Using the width of the [O III] emission line as a proxy for the stellar velocity dispersion, ?{sub *}, we find agreement of our derived host luminosities with the locally observed Faber-Jackson relation. This supports the utility of the width of the [O III] line as a proxy for ?{sub *} in statistical studies.

  19. Self-similar cosmological solutions with dark energy. II. Black holes, naked singularities, and wormholes

    SciTech Connect (OSTI)

    Maeda, Hideki; Harada, Tomohiro; Carr, B. J.

    2008-01-15

    We use a combination of numerical and analytical methods, exploiting the equations derived in a preceding paper, to classify all spherically symmetric self-similar solutions which are asymptotically Friedmann at large distances and contain a perfect fluid with equation of state p=({gamma}-1){mu} with 0<{gamma}<2/3. The expansion of the Friedmann universe is accelerated in this case. We find a one-parameter family of self-similar solutions representing a black hole embedded in a Friedmann background. This suggests that, in contrast to the positive pressure case, black holes in a universe with dark energy can grow as fast as the Hubble horizon if they are not too large. There are also self-similar solutions which contain a central naked singularity with negative mass and solutions which represent a Friedmann universe connected to either another Friedmann universe or some other cosmological model. The latter are interpreted as self-similar cosmological white hole or wormhole solutions. The throats of these wormholes are defined as two-dimensional spheres with minimal area on a spacelike hypersurface and they are all nontraversable because of the absence of a past null infinity.

  20. UNIVERSAL BEHAVIOR OF X-RAY FLARES FROM BLACK HOLE SYSTEMS

    SciTech Connect (OSTI)

    Wang, F. Y.; Dai, Z. G.; Yi, S. X.; Xi, S. Q. E-mail: dzg@nju.edu.cn

    2015-01-01

    X-ray flares have been discovered in black hole systems such as gamma-ray bursts, the tidal disruption event Swift J1644+57, the supermassive black hole Sagittarius A* at the center of our Galaxy, and some active galactic nuclei. Occurrences of X-ray flares are always accompanied by relativistic jets. However, it is still unknown whether or not there is a physical analogy among such X-ray flares produced in black hole systems spanning nine orders of magnitude in mass. Here, we report observed data of X-ray flares and show that they have three statistical properties similar to solar flares, including power-law distributions of their energies, durations, and waiting times, which can be explained by a fractal-diffusive, self-organized criticality model. These statistical similarities, together with the fact that solar flares are triggered by a magnetic reconnection process, suggest that all of the X-ray flares are consistent with magnetic reconnection events, implying that their concomitant relativistic jets may be magnetically dominated.

  1. Inducing chaos by breaking axial symmetry in a black hole magnetosphere

    SciTech Connect (OSTI)

    Kopáček, O.; Karas, V.

    2014-06-01

    While the motion of particles near a rotating, electrically neutral (Kerr), and charged (Kerr-Newman) black hole is always strictly regular, a perturbation in the gravitational or the electromagnetic field generally leads to chaos. The transition from regular to chaotic dynamics is relatively gradual if the system preserves axial symmetry, whereas non-axisymmetry induces chaos more efficiently. Here we study the development of chaos in an oblique (electro-vacuum) magnetosphere of a magnetized black hole. Besides the strong gravity of the massive source represented by the Kerr metric, we consider the presence of a weak, ordered, large-scale magnetic field. An axially symmetric model consisting of a rotating black hole embedded in an aligned magnetic field is generalized by allowing an oblique direction of the field having a general inclination with respect to the rotation axis of the system. The inclination of the field acts as an additional perturbation to the motion of charged particles as it breaks the axial symmetry of the system and cancels the related integral of motion. The axial component of angular momentum is no longer conserved and the resulting system thus has three degrees of freedom. Our primary concern within this contribution is to find out how sensitive the system of bound particles is to the inclination of the field. We employ the method of the maximal Lyapunov exponent to distinguish between regular and chaotic orbits and to quantify their chaoticity. We find that even a small misalignment induces chaotic motion.

  2. Particle-Hole Symmetry Breaking in the Pseudogap State of Bi2201

    SciTech Connect (OSTI)

    Hashimoto, M.; He, R.-H.; Tanaka, K.; Testaud, J.P.; Meevasana1, W.; Moore, R.G.; Lu, D.H.; Yao, H.; Yoshida, Y.; Eisaki, H.; Devereaux, T.P.; Hussain, Z.; Shen, Z.-X.; /SIMES, Stanford /Stanford U., Geballe Lab.

    2011-08-19

    In conventional superconductors, a gap exists in the energy absorption spectrum only below the transition temperature (T{sub c}), corresponding to the energy price to pay for breaking a Cooper pair of electrons. In high-T{sub c} cuprate superconductors above T{sub c}, an energy gap called the pseudogap exists, and is controversially attributed either to pre-formed superconducting pairs, which would exhibit particle-hole symmetry, or to competing phases which would typically break it. Scanning tunnelling microscopy (STM) studies suggest that the pseudogap stems from lattice translational symmetry breaking and is associated with a different characteristic spectrum for adding or removing electrons (particle-hole asymmetry). However, no signature of either spatial or energy symmetry breaking of the pseudogap has previously been observed by angle-resolved photoemission spectroscopy (ARPES). Here we report ARPES data from Bi2201 which reveals both particle-hole symmetry breaking and dramatic spectral broadening indicative of spatial symmetry breaking without long range order, upon crossing through T* into the pseudogap state. This symmetry breaking is found in the dominant region of the momentum space for the pseudogap, around the so-called anti-node near the Brillouin zone boundary. Our finding supports the STM conclusion that the pseudogap state is a broken-symmetry state that is distinct from homogeneous superconductivity.

  3. Distinct oxygen hole doping in different layers of Sr₂CuO4-δ/La₂CuO₄ superlattices

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Smadici, S.; Lee, J. C. T.; Rusydi, A.; Logvenov, G.; Bozovic, I.; Abbamonte, P.

    2012-03-28

    X-ray absorption in Sr₂CuO4-δ/La₂CuO₄ (SCO/LCO) superlattices shows a variable occupation with doping of a hole state different from holes doped for x≲xoptimal in bulk La2-xSrxCuO₄ and suggests that this hole state is on apical oxygen atoms and polarized in the a-b plane. Considering the surface reflectivity gives a good qualitative description of the line shapes of resonant soft x-ray scattering. The interference between superlattice and surface reflections was used to distinguish between scatterers in the SCO and the LCO layers, with the two hole states maximized in different layers of the superlattice.

  4. Identification of the Active Species in Photochemical Hole Scavenging Reactions of Methanol on TiO2

    SciTech Connect (OSTI)

    Shen, Mingmin; Henderson, Michael A.

    2011-11-03

    Molecular and dissociative methanol adsorption species were prepared on rutile TiO2(110) surfaces to study photocatalytic oxidation of methanol in ultrahigh vacuum (UHV) using temperature-programmed desorption (TPD). Adsorbed methoxy groups (CH3O-) were found to be the photoactive form of adsorbed methanol converted to adsorbed formaldehyde and a surface OH group by hole-mediated C-H bond cleavage. These results suggest that adsorbed methoxy is the effective hole scavenger in photochemical reactions involving methanol.

  5. SWIFT OBSERVATIONS OF MAXI J1659-152: A COMPACT BINARY WITH A BLACK HOLE ACCRETOR

    SciTech Connect (OSTI)

    Kennea, J. A.; Romano, P.; Mangano, V.; Beardmore, A. P.; Evans, P. A.; Curran, P. A.; Markwardt, C. B.; Yamaoka, K.

    2011-07-20

    We report on the detection and follow-up high-cadence monitoring observations of MAXI J1659-152, a bright Galactic X-ray binary transient with a likely black hole accretor, by Swift over a 27 day period after its initial outburst detection. MAXI J1659-152 was discovered almost simultaneously by Swift and the Monitor of All-sky X-ray Image on 2010 September 25, and was monitored intensively from the early stages of the outburst through the rise to a brightness of {approx}0.5 Crab by the Swift X-ray, UV/Optical, and the hard X-ray Burst Alert Telescopes. We present temporal and spectral analysis of the Swift observations. The broadband light curves show variability characteristic of black hole candidate transients. We present the evolution of thermal and non-thermal components of the 0.5-150 keV combined X-ray spectra during the outburst. MAXI J1659-152 displays accretion state changes typically associated with black hole binaries, transitioning from its initial detection in the hard state, to the steep power-law state, followed by a slow evolution toward the thermal state, signified by an increasingly dominant thermal component associated with the accretion disk, although this state change did not complete before Swift observations ended. We observe an anti-correlation between the increasing temperature and decreasing radius of the inner edge of the accretion disk, suggesting that the inner edge of the accretion disk infalls toward the black hole as the disk temperature increases. We observed significant evolution in the absorption column during the initial rise of the outburst, with the absorption almost doubling, suggestive of the presence of an evolving wind from the accretion disk. We detect quasi-periodic oscillations that evolve with the outburst, as well as irregular shaped dips that recur with a period of 2.42 {+-} 0.09 hr, strongly suggesting an orbital period that would make MAXI J1659-152 the shortest period black hole binary yet known.

  6. Multi-bit quantum random number generation by measuring positions of arrival photons

    SciTech Connect (OSTI)

    Yan, Qiurong; Zhao, Baosheng; Liao, Qinghong; Zhou, Nanrun

    2014-10-15

    We report upon the realization of a novel multi-bit optical quantum random number generator by continuously measuring the arrival positions of photon emitted from a LED using MCP-based WSA photon counting imaging detector. A spatial encoding method is proposed to extract multi-bits random number from the position coordinates of each detected photon. The randomness of bits sequence relies on the intrinsic randomness of the quantum physical processes of photonic emission and subsequent photoelectric conversion. A prototype has been built and the random bit generation rate could reach 8 Mbit/s, with random bit generation efficiency of 16 bits per detected photon. FPGA implementation of Huffman coding is proposed to reduce the bias of raw extracted random bits. The random numbers passed all tests for physical random number generator.

  7. Network Randomization and Dynamic Defense for Critical Infrastructure Systems

    SciTech Connect (OSTI)

    Chavez, Adrian R.; Martin, Mitchell Tyler; Hamlet, Jason; Stout, William M.S.; Lee, Erik

    2015-04-01

    Critical Infrastructure control systems continue to foster predictable communication paths, static configurations, and unpatched systems that allow easy access to our nation's most critical assets. This makes them attractive targets for cyber intrusion. We seek to address these attack vectors by automatically randomizing network settings, randomizing applications on the end devices themselves, and dynamically defending these systems against active attacks. Applying these protective measures will convert control systems into moving targets that proactively defend themselves against attack. Sandia National Laboratories has led this effort by gathering operational and technical requirements from Tennessee Valley Authority (TVA) and performing research and development to create a proof-of-concept solution. Our proof-of-concept has been tested in a laboratory environment with over 300 nodes. The vision of this project is to enhance control system security by converting existing control systems into moving targets and building these security measures into future systems while meeting the unique constraints that control systems face.

  8. Doorway states in the random-phase approximation

    SciTech Connect (OSTI)

    De Pace, A.; Molinari, A.; Weidenmüller, H.A.

    2014-12-15

    By coupling a doorway state to a sea of random background states, we develop the theory of doorway states in the framework of the random-phase approximation (RPA). Because of the symmetry of the RPA equations, that theory is radically different from the standard description of doorway states in the shell model. We derive the Pastur equation in the limit of large matrix dimension and show that the results agree with those of matrix diagonalization in large spaces. The complexity of the Pastur equation does not allow for an analytical approach that would approximately describe the doorway state. Our numerical results display unexpected features: The coupling of the doorway state with states of opposite energy leads to strong mutual attraction.

  9. Charting an Inflationary Landscape with Random Matrix Theory

    SciTech Connect (OSTI)

    Marsh, M.C. David; McAllister, Liam; Pajer, Enrico; Wrase, Timm E-mail: mcallister@cornell.edu E-mail: timm.wrase@stanford.edu

    2013-11-01

    We construct a class of random potentials for N >> 1 scalar fields using non-equilibrium random matrix theory, and then characterize multifield inflation in this setting. By stipulating that the Hessian matrices in adjacent coordinate patches are related by Dyson Brownian motion, we define the potential in the vicinity of a trajectory. This method remains computationally efficient at large N, permitting us to study much larger systems than has been possible with other constructions. We illustrate the utility of our approach with a numerical study of inflation in systems with up to 100 coupled scalar fields. A significant finding is that eigenvalue repulsion sharply reduces the duration of inflation near a critical point of the potential: even if the curvature of the potential is fine-tuned to be small at the critical point, small cross-couplings in the Hessian cause the curvature to grow in the neighborhood of the critical point.

  10. Random lasing in organo-lead halide perovskite microcrystal networks

    SciTech Connect (OSTI)

    Dhanker, R.; Brigeman, A. N.; Giebink, N. C.; Larsen, A. V.; Stewart, R. J.; Asbury, J. B.

    2014-10-13

    We report optically pumped random lasing in planar methylammonium lead iodide perovskite microcrystal networks that form spontaneously from spin coating. Low thresholds (<200??J/cm{sup 2}) and narrow linewidths (???100??m and spatially overlap with one another, resulting in chaotic pulse-to-pulse intensity fluctuations due to gain competition. These results demonstrate this class of hybrid organic-inorganic perovskite as a platform to study random lasing with well-defined, low-level disorder, and support the potential of these materials for use in semiconductor laser applications.

  11. Intergranular degradation assessment via random grain boundary network analysis

    DOE Patents [OSTI]

    Kumar, Mukul (San Ramon, CA); Schwartz, Adam J. (Pleasanton, CA); King, Wayne E. (San Ramon, CA)

    2002-01-01

    A method is disclosed for determining the resistance of polycrystalline materials to intergranular degradation or failure (IGDF), by analyzing the random grain boundary network connectivity (RGBNC) microstructure. Analysis of the disruption of the RGBNC microstructure may be assess the effectiveness of materials processing in increasing IGDF resistance. Comparison of the RGBNC microstructures of materials exposed to extreme operating conditions to unexposed materials may be used to diagnose and predict possible onset of material failure due to

  12. Cryptographic synchronization recovery by measuring randomness of decrypted data

    DOE Patents [OSTI]

    Maestas, Joseph H. (Albuquerque, NM); Pierson, Lyndon G. (Albuquerque, NM)

    1990-01-01

    The invention relates to synchronization of encrypted data communication systems and a method which looks for any lack of pattern or intelligent information in the received data and triggers a resynchronization signal based thereon. If the encrypter/decrypter pairs are out of cryptographic synchronization, the received (decrypted) data resembles pseudorandom data. A method and system are provided for detecting such pseudorandom binary data by, for example, ones density. If the data is sufficiently random the system is resynchronized.

  13. Graphene materials having randomly distributed two-dimensional structural defects

    DOE Patents [OSTI]

    2013-10-08

    Graphene-based storage materials for high-power battery applications are provided. The storage materials are composed of vertical stacks of graphene sheets and have reduced resistance for Li ion transport. This reduced resistance is achieved by incorporating a random distribution of structural defects into the stacked graphene sheets, whereby the structural defects facilitate the diffusion of Li ions into the interior of the storage materials.

  14. Nonphotochemical Hole-Burning Studies of Energy Transfer Dynamics in Antenna Complexes of Photosynthetic Bacteria

    SciTech Connect (OSTI)

    Satoshi Matsuzaki

    2002-06-27

    This thesis contains the candidate's original work on excitonic structure and energy transfer dynamics of two bacterial antenna complexes as studied using spectral hole-burning spectroscopy. The general introduction is divided into two chapters (1 and 2). Chapter 1 provides background material on photosynthesis and bacterial antenna complexes with emphasis on the two bacterial antenna systems related to the thesis research. Chapter 2 reviews the underlying principles and mechanism of persistent nonphotochemical hole-burning (NPHB) spectroscopy. Relevant energy transfer theories are also discussed. Chapters 3 and 4 are papers by the candidate that have been published. Chapter 3 describes the application of NPHB spectroscopy to the Fenna-Matthews-Olson (FMO) complex from the green sulfur bacterium Prosthecochloris aestuarii; emphasis is on determination of the low energy vibrational structure that is important for understanding the energy transfer process associated within three lowest energy Q{sub y}-states of the complex. The results are compared with those obtained earlier on the FMO complex from Chlorobium tepidum. In Chapter 4, the energy transfer dynamics of the B800 molecules of intact LH2 and B800-deficient LH2 complexes of the purple bacterium Rhodopseudomonas acidophila are compared. New insights on the additional decay channel of the B800 ring of bacteriochlorophyll{sub a} (BChl{sub a}) molecules are provided. General conclusions are given in Chapter 5. A version of the hole spectrum simulation program written by the candidate for the FMO complex study (Chapter 3) is included as an appendix. The references for each chapter are given at the end of each chapter.

  15. INTERACTION OF RECOILING SUPERMASSIVE BLACK HOLES WITH STARS IN GALACTIC NUCLEI

    SciTech Connect (OSTI)

    Li Shuo; Liu, F. K.; Berczik, Peter; Spurzem, Rainer; Chen Xian E-mail: fkliu@bac.pku.edu.cn

    2012-03-20

    Supermassive black hole binaries (SMBHBs) are the products of frequent galaxy mergers. The coalescence of the SMBHBs is a distinct source of gravitational wave (GW) radiation. The detections of the strong GW radiation and their possible electromagnetic counterparts are essential. Numerical relativity suggests that the post-merger supermassive black hole (SMBH) gets a kick velocity up to 4000 km s{sup -1} due to the anisotropic GW radiations. Here, we investigate the dynamical coevolution and interaction of the recoiling SMBHs and their galactic stellar environments with one million direct N-body simulations including the stellar tidal disruption by the recoiling SMBHs. Our results show that the accretion of disrupted stars does not significantly affect the SMBH dynamical evolution. We investigate the stellar tidal disruption rates as a function of the dynamical evolution of oscillating SMBHs in the galactic nuclei. Our simulations show that most stellar tidal disruptions are contributed by the unbound stars and occur when the oscillating SMBHs pass through the galactic center. The averaged disruption rate is {approx}10{sup -6} M{sub Sun} yr{sup -1}, which is about an order of magnitude lower than that by a stationary SMBH at similar galactic nuclei. Our results also show that a bound star cluster is around the oscillating SMBH of about {approx}0.7% the black hole mass. In addition, we discover a massive cloud of unbound stars following the oscillating SMBH. We also investigate the dependence of the results on the SMBH masses and density slopes of the galactic nuclei.

  16. THE FAINT 'HEARTBEATS' OF IGR J17091-3624: AN EXCEPTIONAL BLACK HOLE CANDIDATE

    SciTech Connect (OSTI)

    Altamirano, D.; Van der Klis, M.; Wijnands, R.; Kalamkar, M.; Belloni, T.; Stiele, H.; Motta, S.; Munoz-Darias, T.; Linares, M.; Curran, P. A.; Krimm, H.

    2011-12-15

    We report on the first 180 days of Rossi X-Ray Timing Explorer observations of the outburst of the black hole candidate IGR J17091-3624. This source exhibits a broad variety of complex light curve patterns including periods of strong flares alternating with quiet intervals. Similar patterns in the X-ray light curves have been seen in the (up to now) unique black hole system GRS 1915+105. In the context of the variability classes defined by Belloni et al. for GRS 1915+105, we find that IGR J17091-3624 shows the {nu}, {rho}, {alpha}, {lambda}, {beta}, and {mu} classes as well as quiet periods which resemble the {chi} class, all occurring at 2-60 keV count rate levels which can be 10-50 times lower than observed in GRS 1915+105. The so-called {rho} class 'heartbeats' occur as fast as every few seconds and as slow as {approx}100 s, tracing a loop in the hardness-intensity diagram which resembles that previously seen in GRS 1915+105. However, while GRS 1915+105 traverses this loop clockwise, IGR J17091-3624 does so in the opposite sense. We briefly discuss our findings in the context of the models proposed for GRS 1915+105 and find that either all models requiring near Eddington luminosities for GRS 1915+105-like variability fail, or IGR J17091-3624 lies at a distance well in excess of 20 kpc, or it harbors one of the least massive black holes known (<3 M{sub Sun }).

  17. Biexcitons formed from spatially separated electrons and holes in quasi-zero-dimensional semiconductor nanosystems

    SciTech Connect (OSTI)

    Pokutnyi, S. I.

    2013-12-15

    A theory of biexcitons (formed from spatially separated electron and holes) in nanosystems that consist of zinc-selenide quantum dots synthesized in borosilicate glassy matrices is developed. The dependences of the total energy and the binding energy of the singlet ground biexciton state in such a system on the spacing between the quantum-dot surfaces and the quantum-dot radius are derived by the variational method. It is shown that biexciton formation is of the threshold character and possible in nanosystems, in which the spacing between the quantum-dot surfaces is larger than a certain critical spacing.

  18. Effects of Process Parameters on Ultrasonic Micro-Hole Drilling in Glass and Ruby

    SciTech Connect (OSTI)

    Schorderet, Alain; Deghilage, Emmanuel; Agbeviade, Kossi

    2011-05-04

    Brittle materials such as ceramics, glasses and oxide single crystals find increasing applications in advanced micro-engineering products. Machining small features in such materials represents a manufacturing challenge. Ultrasonic drilling constitutes a promising technique for realizing simple micro-holes of high diameter-to-depth ratio. The process involves impacting abrasive particles in suspension in a liquid slurry between tool and work piece. Among the process performance criteria, the drilling time (productivity) is one of the most important quantities to evaluate the suitability of the process for industrial applications.This paper summarizes recent results pertaining to the ultrasonic micro-drilling process obtained with a semi-industrial 3-axis machine. The workpiece is vibrated at 40 kHz frequency with an amplitude of several micrometers. A voice-coil actuator and a control loop based on the drilling force impose the tool feed. In addition, the tool is rotated at a prescribed speed to improve the drilling speed as well as the hole geometry. Typically, a WC wire serves as tool to bore 200 {mu}m diameter micro-holes of 300 to 1,000 {mu}m depth in glass and ruby. The abrasive slurry contains B4C particles of 1 {mu}m to 5 {mu}m diameter in various concentrations.This paper discusses, on the basis of the experimental results, the influence of several parameters on the drilling time. First, the results show that the control strategy based on the drilling force allows to reach higher feed rates (avoiding tool breakage). Typically, a 8 um/s feed rate is achieved with glass and 0.9 {mu}m/s with ruby. Tool rotation, even for values as low as 50 rpm, increases productivity and improves holes geometry. Drilling with 1 {mu}m and 5 {mu}m B4C particles yields similar productivity results. Our future research will focus on using the presented results to develop a model that can serve to optimize the process for different applications.

  19. Method and apparatus for drilling horizontal holes in geological structures from a vertical bore

    DOE Patents [OSTI]

    Summers, David A. (Rolla, MO); Barker, Clark R. (Rolla, MO); Keith, H. Dean (Rolla, MO)

    1982-01-01

    This invention is directed to a method and apparatus for drilling horizontal holes in geological strata from a vertical position. The geological structures intended to be penetrated in this fashion are coal seams, as for in situ gasification or methane drainage, or in oil-bearing strata for increasing the flow rate from a pre-existing well. Other possible uses for this device might be for use in the leaching of uranium ore from underground deposits or for introducing horizontal channels for water and steam injections.

  20. Bottom-hole contribution: ramifications of Revenue Ruling 80-153

    SciTech Connect (OSTI)

    Dickens, T.L.

    1981-12-01

    Revenue Ruling 80-53 departs from the previous treatment accorded the bottom-hole contribution (BHC), which had been one way for mineral owners to gauge the potential drilling horizons of mineral interests they owned. This analysis of Ruling 80-53 sets forth its direct and indirect implications for the taxpayers, and offers some tax-planning suggestions. It may not be as harsh as was first thought, but taxpayers should develop the necessary tax facts before using BHC in order to avoid its harsh results. 20 references.

  1. The effect of the hole injection layer on the performance of single layer organic light-emitting diodes

    SciTech Connect (OSTI)

    Wenjin, Zeng; Ran, Bi; Hongmei, Zhang E-mail: iamwhuang@njupt.edu.cn; Wei, Huang E-mail: iamwhuang@njupt.edu.cn

    2014-12-14

    Efficient single-layer organic light-emitting diodes (OLEDs) were reported based on a green fluorescent dye 10-(2-benzothiazolyl)-2,3,6,7-tetrahydro-1,1,7,7tetramethyl-1H,5H,11H-(1) benzopyropyrano (6,7-8-I,j)quinolizin-11-one (C545T). Herein, poly(3,4-ethylenedioxy thiophene) poly(styrene sulfonate) were, respectively, applied as the injection layer for comparison. The hole transport properties of the emission layer with different hole injection materials are well investigated via current-voltage measurement. It was clearly found that the hole injection layers (HILs) play an important role in the adjustment of the electron/hole injection to attain transport balance of charge carriers in the single emission layer of OLEDs with electron-transporting host. The layer of tris-(8-hydroxyquinoline) aluminum played a dual role of host and electron-transporting materials within the emission layer. Therefore, appropriate selection of hole injection layer is a key factor to achieve high efficiency OLEDs with single emission layer.

  2. Quantum Statistical Testing of a Quantum Random Number Generator

    SciTech Connect (OSTI)

    Humble, Travis S

    2014-01-01

    The unobservable elements in a quantum technology, e.g., the quantum state, complicate system verification against promised behavior. Using model-based system engineering, we present methods for verifying the opera- tion of a prototypical quantum random number generator. We begin with the algorithmic design of the QRNG followed by the synthesis of its physical design requirements. We next discuss how quantum statistical testing can be used to verify device behavior as well as detect device bias. We conclude by highlighting how system design and verification methods must influence effort to certify future quantum technologies.

  3. Random effects of fissile lumps in molten salt reactors

    SciTech Connect (OSTI)

    Dulla, S.; Ravetto, P.; Prinja, A. K.

    2013-07-01

    The problem of the effect of fissile lumps spatially appearing in a random fashion inside a fluid fuel reactor is addressed. The effect on reactivity is evaluated by means of first-order perturbation theory. The analysis is carried out in diffusion theory with the presence of delayed neutron emissions in one dimensional plane geometry. The estimation of the mean value and standard deviation of the reactivity inserted is performed by Monte Carlo simulations and a deterministic quadrature approach, to compare the methods in terms of computational effort and the accuracy of the results. The results presented show that the effects constitute an important issue in the assessment of these innovative systems. (authors)

  4. Alternating current response of carbon nanotubes with randomly distributed impurities

    SciTech Connect (OSTI)

    Hirai, Daisuke; Watanabe, Satoshi [Department of Materials Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); Yamamoto, Takahiro [Department of Electrical Engineering and Department of Liberal Arts (Physics), Tokyo University of Science, 6-3-1 Niijuku, Katsushika, Tokyo 125-8585 (Japan)

    2014-10-27

    The increasing need for nanodevices has necessitated a better understanding of the electronic transport behavior of nanomaterials. We therefore theoretically examine the AC transport properties of metallic carbon nanotubes with randomly distributed impurities. We find that the long-range impurity scattering increases the emittance, but does not affect the DC conductance. The estimated dwell time of electrons increases with the potential amplitudes. That is, multiple scattering by the impurities increases the kinetic inductance in proportion to the dwell time, which eventually increases the emittance. We believe that our findings can contribute significantly to nanodevice development.

  5. Random paths and current fluctuations in nonequilibrium statistical mechanics

    SciTech Connect (OSTI)

    Gaspard, Pierre

    2014-07-15

    An overview is given of recent advances in nonequilibrium statistical mechanics about the statistics of random paths and current fluctuations. Although statistics is carried out in space for equilibrium statistical mechanics, statistics is considered in time or spacetime for nonequilibrium systems. In this approach, relationships have been established between nonequilibrium properties such as the transport coefficients, the thermodynamic entropy production, or the affinities, and quantities characterizing the microscopic Hamiltonian dynamics and the chaos or fluctuations it may generate. This overview presents results for classical systems in the escape-rate formalism, stochastic processes, and open quantum systems.

  6. Plasmonic modes and extinction properties of a random nanocomposite cylinder

    SciTech Connect (OSTI)

    Moradi, Afshin

    2014-04-15

    We study the properties of surface plasmon-polariton waves of a random metal-dielectric nanocomposite cylinder, consisting of bulk metal embedded with dielectric nanoparticles. We use the Maxwell-Garnett formulation to model the effective dielectric function of the composite medium and show that there exist two surface mode bands. We investigate the extinction properties of the system, and obtain the dependence of the extinction spectrum on the nanoparticles shape and concentration as well as the cylinder radius and the incidence angle for both TE and TM polarization.

  7. Subsurface exploration using bucket auger borings and down-hole geologic inspection

    SciTech Connect (OSTI)

    Scullin, C.M. )

    1994-03-01

    The down-hole geologic inspection of 24 in. bucket auger borings has been a hands-on technique for collecting valuable geologic structural and lithologic detail in southern California investigations for over 35 yr. Although it has been used for all types of investigations for hillside urban development, it is of particular benefit in landslide investigations and evaluations. The benefits of down-hole geologic inspection during detailed mapping of large landslide complexes with multiple slide planes are discussed in this paper. Many of the geotechnical investigations of these massive landslide complexes have been very limited in their determinations of accurate landslide parameters and very deficient in proper engineering analysis while based upon this limited data. This has resulted in many cases where the geotechnical consultant erroneously concludes that ancient landslides don't move and it is all right to build upon them, even though they have neither justified the landslide parameters, nor the slope stability or safety. Because this author and the many consultants contacted during the preparation of this paper were not aware of other publications regarding this method of collecting detailed geologic data, this author included the safety considerations, safety equipment, the cost and the Cal OSHA requirements for entering exploration shafts.

  8. Nonphotochemical Hole-Burning Studies of Energy Transfer Dynamics in Antenna Complexes of Photosynthetic Bacteria

    SciTech Connect (OSTI)

    Satoshi Matsuzaki

    2002-08-01

    This thesis contains the candidate's original work on excitonic structure and energy transfer dynamics of two bacterial antenna complexes as studied using spectral hole-burning spectroscopy. The general introduction is divided into two chapters (1 and 2). Chapter 1 provides background material on photosynthesis and bacterial antenna complexes with emphasis on the two bacterial antenna systems related to the thesis research. Chapter 2 reviews the underlying principles and mechanism of persistent nonphotochemical hole-burning (NPHB) spectroscopy. Relevant energy transfer theories are also discussed. Chapters 3 and 4 are papers by the candidate that have been published. Chapter 3 describes the application of NPHB spectroscopy to the Fenna-Matthews-Olson (FMO) complex from the green sulfur bacterium Prosthecochloris aestuarii; emphasis is on determination of the low energy vibrational structure that is important for understanding the energy transfer process associated within three lowest energy Qy-states of the complex. The results are compared with those obtained earlier on the FMO complex from Chlorobium tepidum. In Chapter 4, the energy transfer dynamics of the B800 molecules of intact LH2 and B800-deficient LH2 complexes of the purple bacterium Rhodopseudomonas acidophila are compared. New insights on the additional decay channel of the B800 ring of bacteriochlorophyll a (BChl a) molecules are provided. General conclusions are given in Chapter 5.

  9. X-RAY CONSTRAINTS ON THE LOCAL SUPERMASSIVE BLACK HOLE OCCUPATION FRACTION

    SciTech Connect (OSTI)

    Miller, Brendan P.; Gallo, Elena; Baldassare, Vivienne; Greene, Jenny E.; Kelly, Brandon C.; Treu, Tommaso; Woo, Jong-Hak

    2015-01-20

    Distinct seed formation mechanisms are imprinted upon the fraction of dwarf galaxies currently containing a central supermassive black hole. Seeding by Population III remnants is expected to produce a higher occupation fraction than is generated with direct gas collapse precursors. Chandra observations of nearby early-type galaxies can directly detect even low-level supermassive black hole activity, and the active fraction immediately provides a firm lower limit to the occupation fraction. Here, we use the volume-limited AMUSE surveys of ?200 optically selected early-type galaxies to characterize simultaneously, for the first time, the occupation fraction and the scaling of L {sub X} with M {sub star}, accounting for intrinsic scatter, measurement uncertainties, and X-ray limits. For early-type galaxies with M {sub star} < 10{sup 10} M {sub ?}, we obtain a lower limit to the occupation fraction of >20% (at 95% confidence), but full occupation cannot be excluded. The preferred dependence of log L {sub X} upon log M {sub star} has a slope of ?0.7-0.8, consistent with the ''downsizing'' trend previously identified from the AMUSE data set, and a uniform Eddington efficiency is disfavored at ?2?. We provide guidelines for the future precision with which these parameters may be refined with larger or more sensitive samples.

  10. Out of the white hole: a holographic origin for the Big Bang

    SciTech Connect (OSTI)

    Pourhasan, Razieh; Afshordi, Niayesh; Mann, Robert B. E-mail: nafshordi@pitp.ca

    2014-04-01

    While most of the singularities of General Relativity are expected to be safely hidden behind event horizons by the cosmic censorship conjecture, we happen to live in the causal future of the classical Big Bang singularity, whose resolution constitutes the active field of early universe cosmology. Could the Big Bang be also hidden behind a causal horizon, making us immune to the decadent impacts of a naked singularity? We describe a braneworld description of cosmology with both 4d induced and 5D bulk gravity (otherwise known as Dvali-Gabadadze-Porati, or DGP model), which exhibits this feature: the universe emerges as a spherical 3-brane out of the formation of a 5D Schwarzschild black hole. In particular, we show that a pressure singularity of the holographic fluid, discovered earlier, happens inside the white hole horizon, and thus need not be real or imply any pathology. Furthermore, we outline a novel mechanism through which any thermal atmosphere for the brane, with comoving temperature of ?20% of the 5D Planck mass can induce scale-invariant primordial curvature perturbations on the brane, circumventing the need for a separate process (such as cosmic inflation) to explain current cosmological observations. Finally, we note that 5D space-time is asymptotically flat, and thus potentially allows an S-matrix or (after minor modifications) an AdS/CFT description of the cosmological Big Bang.

  11. THE MISSING GOLIATH'S SLINGSHOT: MASSIVE BLACK HOLE RECOIL AT M83

    SciTech Connect (OSTI)

    Dottori, Horacio; Diaz, Ruben J.; Facundo Albacete-Colombo, Juan

    2010-07-01

    The Fanaroff-Riley II radio source J133658.3-295105, which is also an X-ray source, appears to be projected onto the disk of the barred-spiral galaxy M83 at about 60'' from the galaxy's optical nucleus. J133658.3-295105 and its radio lobes are aligned with the optical nucleus of M 83 and two other radio sources, neither of which are supernova remnants or H II regions. Due to this peculiar on-the-sky projection, J133658.3-295105 was previously studied by Gemini+GMOS optical spectroscopy, which marginally revealed the presence of H{alpha} in emission receding at 130 km s{sup -1} with respect to the optical nucleus. In this Letter, we reanalyze the Chandra spectroscopy carried out in 2000. We show that J133658.3-295105 presents an Fe K{alpha} emission line at a redshift of z = 0.018. This redshift is compatible with a black hole at the distance of M 83. We discuss similarities to the recently reported micro-quasar in NGC 5408. This finding reinforces the kicked-off black hole scenario for J133658.3-295105.

  12. Gallium hole traps in irradiated KTiOPO{sub 4}:Ga crystals

    SciTech Connect (OSTI)

    Grachev, V.; Meyer, M.; Malovichko, G.; Hunt, A. W.

    2014-12-07

    Nominally pure and gallium doped single crystals of potassium titanyl phosphate (KTiOPO{sub 4}) have been studied by Electron Paramagnetic Resonance at low temperatures before and after irradiation. Irradiation with 20?MeV electrons performed at room temperature and liquid nitrogen temperature caused an appearance of electrons and holes. Gallium impurities act as hole traps in KTiOPO{sub 4} creating Ga{sup 4+} centers. Two different Ga{sup 4+} centers were observed, Ga1 and Ga2. The Ga1 centers are dominant in Ga-doped samples. For the Ga1 center, a superhyperfine structure with one nucleus with nuclear spin was registered and attributed to the interaction of gallium electrons with a phosphorus nucleus or proton in its surrounding. In both Ga1 and Ga2 centers, Ga{sup 4+} ions substitute for Ti{sup 4+} ions, but with a preference to one of two electrically distinct crystallographic positions (site selective substitution). The Ga doping eliminates one of the shortcomings of KTP crystalsionic conductivity of bulk crystals. However, this does not improve significantly the resistance of the crystals to electron and ?-radiation.

  13. Casingless down-hole for sealing an ablation volume and obtaining a sample for analysis

    DOE Patents [OSTI]

    Noble, Donald T. (Ames, IA); Braymen, Steven D. (Ames, IA); Anderson, Marvin S. (Ames, IA)

    1996-10-01

    A casing-less down hole sampling system for acquiring a subsurface sample for analysis using an inductively coupled plasma system is disclosed. The system includes a probe which is pushed into the formation to be analyzed using a hydraulic ram system. The probe includes a detachable tip member which has a soil point mad a barb, with the soil point aiding the penetration of the earth, and the barb causing the tip member to disengage from the probe and remain in the formation when the probe is pulled up. The probe is forced into the formation to be tested, and then pulled up slightly, to disengage the tip member and expose a column of the subsurface formation to be tested. An instrumentation tube mounted in the probe is then extended outward from the probe to longitudinally extend into the exposed column. A balloon seal mounted on the end of the instrumentation tube allows the bottom of the column to be sealed. A source of laser radiation is emitted from the instrumentation tube to ablate a sample from the exposed column. The instrumentation tube can be rotated in the probe to sweep the laser source across the surface of the exposed column. An aerosol transport system carries the ablated sample from the probe to the surface for testing in an inductively coupled plasma system. By testing at various levels in the down-hole as the probe is extracted from the soil, a profile of the subsurface formation may be obtained.

  14. Coiled tubing stimulations eliminate hole failures & condensate losses in Arun field

    SciTech Connect (OSTI)

    Bunnell, F.D.; Daud, M.M.

    1995-12-31

    Stimulation practices have evolved considerably over the life of the Arun Field. From the original HCl matrix treatments in the late 70`s to the organic matrix and acid fracture treatments through the early 90`s these techniques have proven effective. Beginning in recent years however, some problems have been observed. Problems include collapsing shales plugging one well and sharp drops in the condensate/gas ratio following stimulation in others. Open hole completions with a limited casing/cement barrier between the over pressured shale and the depleting Arun reservoir are subject to shale collapse and plugging when directly exposed to acid during conventional stimulations. Most Arun completions are subject to post stimulation condensate losses due to increasingly difficult conditions for effective diversion of acid treatment fluids. Acid stimulation using coiled tubing techniques effectively addresses these problems. In seven stimulations performed to date shale failures and condensate losses have been eliminated. Direct acid washing across deeper intervals helps protect the acid sensitive barrier in open hole completions and effectively treats the lower, condensate rich zones.

  15. UPDATED MASS SCALING RELATIONS FOR NUCLEAR STAR CLUSTERS AND A COMPARISON TO SUPERMASSIVE BLACK HOLES

    SciTech Connect (OSTI)

    Scott, Nicholas; Graham, Alister W.

    2013-02-15

    We investigate whether or not nuclear star clusters and supermassive black holes (SMBHs) follow a common set of mass scaling relations with their host galaxy's properties, and hence can be considered to form a single class of central massive object (CMO). We have compiled a large sample of galaxies with measured nuclear star cluster masses and host galaxy properties from the literature and fit log-linear scaling relations. We find that nuclear star cluster mass, M {sub NC}, correlates most tightly with the host galaxy's velocity dispersion: log M {sub NC} = (2.11 {+-} 0.31)log ({sigma}/54) + (6.63 {+-} 0.09), but has a slope dramatically shallower than the relation defined by SMBHs. We find that the nuclear star cluster mass relations involving host galaxy (and spheroid) luminosity and stellar and dynamical mass, intercept with but are in general shallower than the corresponding black hole scaling relations. In particular, M {sub NC}{proportional_to}M {sup 0.55{+-}0.15} {sub Gal,dyn}; the nuclear cluster mass is not a constant fraction of its host galaxy or spheroid mass. We conclude that nuclear stellar clusters and SMBHs do not form a single family of CMOs.

  16. Location Of Hole And Electron Traps On Nanocrystalline Anatase TiO2

    SciTech Connect (OSTI)

    Mercado, Candy C.; Knorr, Fritz J.; McHale, Jeanne L.; Usmani, Shirin M.; Ichimura, Andrew S.; Saraf, Laxmikant V.

    2012-05-17

    The defect photoluminescence from TiO2 nanoparticles in the anatase phase is reported for nanosheets which expose predominantly (001) surfaces, and compared to that from conventional anatase nanoparticles which expose mostly (101) surfaces. Also reported is the weak defect photoluminescence of TiO2 nanotubes, which we find using electron back-scattered diffraction to consist of walls which expose (110) and (100) facets. The nanotubes exhibit photoluminescence that is blue-shifted and much weaker than that from conventional TiO2 nanoparticles. Despite the preponderance of (001) surfaces in the nanosheet samples, they exhibit photoluminescence similar to that of conventional nanoparticles. We assign the broad visible photoluminescence of anatase nanoparticles to two overlapping distributions: hole trap emission associated with oxygen vacancies on (101) exposed surfaces, which peaks in the green, and a broader emission extending into the red which results from electron traps on under-coordinated titanium atoms, which are prevalent on (001) facets. The results of this study suggest how morphology of TiO2 nanoparticles could be optimized to control the distribution and activity of surface traps. Our results also shed light on the mechanism by which the TiCl4 surface treatment heals traps on anatase and mixed-phase TiO2 films, and reveals distinct differences in the trap-state distributions of TiO2 nanoparticles and nanotubes. The molecular basis for electron and hole traps and their spatial separation on different facets is discussed.

  17. Casingless down-hole for sealing an ablation volume and obtaining a sample for analysis

    DOE Patents [OSTI]

    Noble, D.T.; Braymen, S.D.; Anderson, M.S.

    1996-10-01

    A casing-less down hole sampling system for acquiring a subsurface sample for analysis using an inductively coupled plasma system is disclosed. The system includes a probe which is pushed into the formation to be analyzed using a hydraulic ram system. The probe includes a detachable tip member which has a soil point and a barb, with the soil point aiding the penetration of the earth, and the barb causing the tip member to disengage from the probe and remain in the formation when the probe is pulled up. The probe is forced into the formation to be tested, and then pulled up slightly, to disengage the tip member and expose a column of the subsurface formation to be tested. An instrumentation tube mounted in the probe is then extended outward from the probe to longitudinally extend into the exposed column. A balloon seal mounted on the end of the instrumentation tube allows the bottom of the column to be sealed. A source of laser radiation is emitted from the instrumentation tube to ablate a sample from the exposed column. The instrumentation tube can be rotated in the probe to sweep the laser source across the surface of the exposed column. An aerosol transport system carries the ablated sample from the probe to the surface for testing in an inductively coupled plasma system. By testing at various levels in the down-hole as the probe is extracted from the soil, a profile of the subsurface formation may be obtained. 9 figs.

  18. Milagro limits and HAWC sensitivity for the rate-density of evaporating primordial black holes

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abdo, A. A.; Abeysekara, A. U.; Alfaro, R.; Allen, B. T.; Alvarez, C.; Alvarez, J. D.; Arceo, R.; Arteaga-Velazquez, J. C.; Aune, T.; H. A. Ayala Solares; et al

    2015-04-01

    Primordial Black Holes (PBHs) are gravitationally collapsed objects that may have been created by density fluctuations in the early universe and could have arbitrarily small masses down to the Planck scale. Hawking showed that due to quantum effects, a black hole has a temperature inversely proportional to its mass and will emit all species of fundamental particles thermally. PBHs with initial masses of ~ 5.0 × 10¹⁴ g should be expiring in the present epoch with bursts of high-energy particles, including gamma radiation in the GeV – TeV energy range. The Milagro high energy observatory, which operated from 2000 tomore » 2008, is sensitive to the high end of the PBH evaporation gamma-ray spectrum. Due to its large field-of-view, more than 90% duty cycle and sensitivity up to 100 TeV gamma rays, the Milagro observatory is well suited to perform a search for PBH bursts. Based on a search on the Milagro data, we report new PBH burst rate density upper limits over a range of PBH observation times. In addition, we report the sensitivity of the Milagro successor, the High Altitude Water Cherenkov (HAWC) observatory, to PBH evaporation events.« less

  19. Quantum compositeness of gravity: black holes, AdS and inflation

    SciTech Connect (OSTI)

    Dvali, Gia; Gomez, Cesar E-mail: cesar.gomez@uam.es

    2014-01-01

    Gravitational backgrounds, such as black holes, AdS, de Sitter and inflationary universes, should be viewed as composite of N soft constituent gravitons. It then follows that such systems are close to quantum criticality of graviton Bose-gas to Bose-liquid transition. Generic properties of the ordinary metric description, including geodesic motion or particle-creation in the background metric, emerge as the large-N limit of quantum scattering of constituent longitudinal gravitons. We show that this picture correctly accounts for physics of large and small black holes in AdS, as well as reproduces well-known inflationary predictions for cosmological parameters. However, it anticipates new effects not captured by the standard semi-classical treatment. In particular, we predict observable corrections that are sensitive to the inflationary history way beyond last 60 e-foldings. We derive an absolute upper bound on the number of e-foldings, beyond which neither de Sitter nor inflationary Universe can be approximated by a semi-classical metric. However, they could in principle persist in a new type of quantum eternity state. We discuss implications of this phenomenon for the cosmological constant problem.

  20. NREL Improves Hole Transport in Sensitized CdS-NiO Nanoparticle Photocathodes (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-01-01

    Significantly improved charge-collection efficiencies result from a general chemical approach to synthesizing photocathodes. It has been reported that a dye-sensitized nickel oxide (NiO) photocathode, when coupled to a dye-sensitized photoanode, could significantly increase overall solar conversion efficiency. However, the conversion efficiencies of these cells are still low. There has been much effort to improve the conversion efficiency by fabricating films with improved properties and developing more effective sensitizing dyes for p-type NiO. One of the factors limiting the use of NiO for solar cell application is the low hole conductivity in p-NiO. A team of researchers from the National Renewable Energy Laboratory (NREL) developed a general chemical approach to synthesize NiO-cadmium sulfide (CdS) core-shell nanoparticle films as photocathodes for p-type semiconductor-sensitized solar cells. Compared to dye-sensitized NiO photocathodes, the CdS-sensitized NiO cathodes exhibited two orders of magnitude faster hole transport (attributable to the passivation of surface traps by the CdS) and almost 100% charge-collection efficiencies.

  1. Hole Burning Imaging Studies of Cancerous and Analogous Normal Ovarian Tissues Utilizing Organelle Specific Dyes

    SciTech Connect (OSTI)

    Satoshi Matsuzaki

    2004-12-19

    Presented in this dissertation is the successful demonstration that nonphotochemical hole burning (NPWB) imaging can be used to study in vitro tissue cellular systems for discerning differences in cellular ultrastructures due to cancer development. This has been accomplished with the surgically removed cancerous ovarian and analogous normal peritoneal tissues from the same patient and the application of a fluorescent mitochondrion specific dye, Molecular Probe MitoFluor Far Red 680 (MF680), commonly known as rhodamine 800, that has been proven to exhibit efficient NPHB. From the results presented in Chapters 4 and 5 , and Appendix B, the following conclusions were made: (1) fluorescence excitation spectra of MF680 and confocal microscopy images of thin sliced tissues incubated with MF680 confirm the site-specificity of the probe molecules in the cellular systems. (2) Tunneling parameters, {lambda}{sub 0} and {sigma}{sub {lambda}}, as well as the standard hole burning parameters (namely, {gamma} and S), have been determined for the tissue samples by hole growth kinetics (HGK) analyses. Unlike the preliminary cultured cell studies, these parameters have not shown the ability to distinguish tissue cellular matrices surrounding the chromophores. (3) Effects of an external electric (Stark) field on the nonphotochemical holes have been used to determine the changes in permanent dipole moment (f{Delta}{mu}) for MF680 in tissue samples when burn laser polarization is parallel to the Stark field. Differences are detected between f{Delta}{mu}s in the two tissue samples, with the cancerous tissue exhibiting a more pronounced change (1.35-fold increase) in permanent dipole moment change relative to the normal analogs. It is speculated that the difference may be related to differences in mitochondrial membrane potentials in these tissue samples. (4) In the HGK mode, hole burning imaging (HBI) of cells adhered to coverslips and cooled to liquid helium temperatures in the complete absence of cryopreservatives, shows the ability to distinguish between carcinoma and analogous normal cells on the single-cell level. In future applications, this system has the potential to be used with smears of tissue samples for single-layer HBI analysis. These conclusions demonstrate that HBI has the potential of providing detailed information about localized intracellular environments and for detecting changes in the physical characteristics (e.g., electrical properties) of cells which constitute the in vitro tissue samples. For the latter, the long-term goal will be to develop NPHB into a diagnostic technique for the early detection of cancer by exploiting the physical differences between normal and cancerous cells and tissues. Moreover, because of the aforementioned HBI's capability to detect cellular anomalies, it has the potential of being used in conjunction with studies involving photodynamic therapy, assuming the chromophore is carefully selected.

  2. Direct probing of electron and hole trapping into nano-floating-gate in organic field-effect transistor nonvolatile memories

    SciTech Connect (OSTI)

    Cui, Ze-Qun; Wang, Shun; Chen, Jian-Mei; Gao, Xu; Dong, Bin E-mail: chilf@suda.edu.cn Chi, Li-Feng E-mail: chilf@suda.edu.cn Wang, Sui-Dong E-mail: chilf@suda.edu.cn

    2015-03-23

    Electron and hole trapping into the nano-floating-gate of a pentacene-based organic field-effect transistor nonvolatile memory is directly probed by Kelvin probe force microscopy. The probing is straightforward and non-destructive. The measured surface potential change can quantitatively profile the charge trapping, and the surface characterization results are in good accord with the corresponding device behavior. Both electrons and holes can be trapped into the nano-floating-gate, with a preference of electron trapping than hole trapping. The trapped charge quantity has an approximately linear relation with the programming/erasing gate bias, indicating that the charge trapping in the device is a field-controlled process.

  3. Calculation of output characteristics of semiconductor quantum-well lasers with account for both electrons and holes

    SciTech Connect (OSTI)

    Sokolova, Z N; Tarasov, I S; Asryan, L V

    2014-09-30

    Using an extended theoretical model, which includes the rate equations for both electrons and holes, we have studied the output characteristics of semiconductor quantum-well lasers. We have found non-trivial dependences of electron and hole concentrations in the waveguide region of the laser on the capture velocities of both types of carriers from the waveguide region into the quantum well. We have obtained the dependences of the internal differential quantum efficiency and optical output power of the laser on the capture velocities of electrons and holes. An increase in the capture velocities has been shown to result in suppression of parasitic recombination in the waveguide region and therefore in a substantial increase in the quantum efficiency and output power. (lasers)

  4. UNLEASHING POSITIVE FEEDBACK: LINKING THE RATES OF STAR FORMATION, SUPERMASSIVE BLACK HOLE ACCRETION, AND OUTFLOWS IN DISTANT GALAXIES

    SciTech Connect (OSTI)

    Silk, Joseph

    2013-08-01

    Pressure-regulated star formation is a simple variant on the usual supernova-regulated star formation efficiency that controls the global star formation rate as a function of cold gas content in star-forming galaxies, and accounts for the Schmidt-Kennicutt law in both nearby and distant galaxies. Inclusion of active galactic nucleus (AGN) induced pressure, by jets and/or winds that flow back onto a gas-rich disk, can lead, under some circumstances, to significantly enhanced star formation rates, especially at high redshift and most likely followed by the more widely accepted phase of star formation quenching. Simple expressions are derived that relate supermassive black hole growth, star formation, and outflow rates. The ratios of black hole to spheroid mass and of both black hole accretion and outflow rates to star formation rate are predicted as a function of time. I suggest various tests of the AGN-triggered star formation hypothesis.

  5. Observation of a hole-size-dependent energy shift of the surface-plasmon resonance in Ni antidot thin films

    SciTech Connect (OSTI)

    Fang, H.; Akinoglu, E. M.; Fumagalli, P.; Caballero, B.; Garca-Martn, A.; Papaioannou, E. Th.; Cuevas, J. C.; Giersig, M.

    2015-04-13

    A combined experimental and theoretical study of the magneto-optic properties of a series of nickel antidot thin films is presented. The hole diameter varies from 869 down to 636?nm, while the lattice periodicity is fixed at 920?nm. This results in an overall increase of the polar Kerr rotation with decreasing hole diameter due to the increasing surface coverage with nickel. In addition, at photon energies of 2.7 and 3.3?eV, where surface-plasmon excitations are expected, we observe distinct features in the polar Kerr rotation not present in continuous nickel films. The spectral position of the peaks exhibits a red shift with decreasing hole size. This is explained within the context of an effective medium theory by a change in the effective dielectric function of the Ni thin films.

  6. A parallax distance to the microquasar GRS 1915+105 and a revised estimate of its black hole mass

    SciTech Connect (OSTI)

    Reid, M. J.; McClintock, J. E.; Steiner, J. F.; Narayan, R.; Steeghs, D.; Remillard, R. A.; Dhawan, V.

    2014-11-20

    Using the Very Long Baseline Array, we have measured a trigonometric parallax for the microquasar GRS 1915+105, which contains a black hole and a K-giant companion. This yields a direct distance estimate of 8.6{sub ?1.6}{sup +2.0} kpc and a revised estimate for the mass of the black hole of 12.4{sub ?1.8}{sup +2.0} M {sub ?}. GRS 1915+105 is at about the same distance as some H II regions and water masers associated with high-mass star formation in the Sagittarius spiral arm of the Galaxy. The absolute proper motion of GRS 1915+105 is 3.19 0.03 mas yr{sup 1} and 6.24 0.05 mas yr{sup 1} toward the east and north, respectively, which corresponds to a modest peculiar speed of 22 24 km s{sup 1} at the parallax distance, suggesting that the binary did not receive a large velocity kick when the black hole formed. On one observational epoch, GRS 1915+105 displayed superluminal motion along the direction of its approaching jet. Considering previous observations of jet motions, the jet in GRS 1915+105 can be modeled with a jet inclination to the line of sight of 60 5 and a variable flow speed between 0.65c and 0.81c, which possibly indicates deceleration of the jet at distances from the black hole ? 2000 AU. Finally, using our measurements of distance and estimates of black hole mass and inclination, we provisionally confirm our earlier result that the black hole is spinning very rapidly.

  7. Practical and fast quantum random number generation based on photon arrival time relative to external reference

    SciTech Connect (OSTI)

    Nie, You-Qi; Zhang, Jun Pan, Jian-Wei; Zhang, Hong-Fei; Wang, Jian; Zhang, Zhen; Ma, Xiongfeng

    2014-02-03

    We present a practical high-speed quantum random number generator, where the timing of single-photon detection relative to an external time reference is measured as the raw data. The bias of the raw data can be substantially reduced compared with the previous realizations. The raw random bit rate of our generator can reach 109 Mbps. We develop a model for the generator and evaluate the min-entropy of the raw data. Toeplitz matrix hashing is applied for randomness extraction, after which the final random bits are able to pass the standard randomness tests.

  8. Chandra spectroscopy of MAXI J1305704: Detection of an infalling black hole disk wind?

    SciTech Connect (OSTI)

    Miller, J. M.; Maitra, D.; Reynolds, M. T.; Degenaar, N.; King, A. L.; Raymond, J.; Kallman, T. R.; Fabian, A. C.; Proga, D.; Reynolds, C. S.; Cackett, E. M.; Kennea, J. A.; Beardmore, A.

    2014-06-10

    We report on a high-resolution Chandra/HETG X-ray spectrum of the transient X-ray binary MAXI J1305704. A rich absorption complex is detected in the Fe L band, including density-sensitive lines from Fe XX, Fe XXI, and Fe XXII. Spectral analysis over three wavelength bands with a large grid of XSTAR photoionization models generally requires a gas density of n ? 10{sup 17} cm{sup 3}. Assuming a luminosity of L = 10{sup 37} erg s{sup 1}, fits to the 10-14 band constrain the absorbing gas to lie within r = (3.9 0.7) 10{sup 3} km from the central engine, or about r = 520 90 (M/5 M {sub ?}) r{sub g} , where r{sub g} = GM/c {sup 2}. At this small distance from the compact object, gas in stable orbits should have a gravitational redshift of z = v/c ? (3 1) 10{sup 3} (M/5 M {sub ?}), and any tenuous inflowing gas should have a free-fall velocity of v/c ? (6 1) 10{sup 2} (M/5 M {sub ?}){sup 1/2}. The best-fit single-zone photoionization models measure a redshift of v/c = (2.6-3.2) 10{sup 3}. Models with two absorbing zones provide significantly improved fits, and the additional zone is measured to have a redshift of v/c = (4.6-4.9) 10{sup 2} (models including two zones suggest slightly different radii and may point to lower densities). Thus, the observed shifts are broadly consistent with those expected at the photoionization radius. The absorption spectrum revealed in MAXI J1305704 may be best explained in terms of a 'failed wind' like those predicted in some recent numerical simulations of black hole accretion flows. The robustness of the velocity shifts was explored through detailed simulations with the Chandra/MARX ray-tracing package and analysis of the zeroth-order ACIS-S3 spectrum. These tests are particularly important given the anomalously large angle between the source and the optical axis in this observation. The simulations and ACIS spectrum suggest that the shifts are not instrumental; however, strong caution is warranted. We discuss our results in the context of accretion flows in stellar-mass black holes and active galactic nuclei, as well as the potential role of failed winds in emerging connections between disk outflows and black hole state transitions.

  9. MEASUREMENTS OF ANISOTROPIC ION TEMPERATURES, NON-THERMAL VELOCITIES, AND DOPPLER SHIFTS IN A CORONAL HOLE

    SciTech Connect (OSTI)

    Hahn, M.; Savin, D. W.

    2013-02-15

    We present a new diagnostic allowing one to measure the anisotropy of ion temperatures and non-thermal velocities, as well as Doppler shifts with respect to the ambient magnetic field. This method provides new results, as well as an independent test for previous measurements obtained with other techniques. Our spectral data come from observations of a low-latitude, on-disk coronal hole. A potential field source surface model was used to calculate the angle between the magnetic field lines and the line of sight for each spatial bin of the observation. A fit was performed to determine the line widths and Doppler shifts parallel and perpendicular to the magnetic field. For each line width component we derived ion temperatures T {sub i,} and T {sub i, Parallel-To} and non-thermal velocities v {sub nt,} and v {sub nt, Parallel-To }. T {sub i,} was cooler than off-limb polar coronal hole measurements, suggesting increasing collisional cooling with decreasing height. T {sub i, Parallel-To} is consistent with a uniform temperature of (1.8 {+-} 0.2) Multiplication-Sign 10{sup 6} K for each ion. Since parallel ion heating is expected to be weak, this ion temperature should reflect the proton temperature. A comparison between our results and others implies a large proton temperature gradient around 1.02 R {sub Sun }. The non-thermal velocities are thought to be proportional to the amplitudes of various waves. Our results for v {sub nt,} agree with Alfven wave amplitudes inferred from off-limb polar coronal hole line width measurements. Our v {sub nt, Parallel-To} results are consistent with slow magnetosonic wave amplitudes inferred from Fourier analysis of time-varying intensity fluctuations. Doppler shift measurements yield outflows of Almost-Equal-To 5 km s{sup -1} for ions formed over a broad temperature range. This differs from other studies that found a strong Doppler shift dependence on formation temperature.

  10. Voltage measurements at the vacuum post-hole convolute of the ? pulsed-power accelerator

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Waisman, E.? M.; McBride, R. D.; Cuneo, M.? E.; Wenger, D.? F.; Fowler, W.? E.; Johnson, W.? A.; Basilio, L.? I.; Coats, R.? S.; Jennings, C.? A.; Sinars, D.? B.; et al

    2014-11-08

    Presented are voltage measurements taken near the load region on the Z pulsed-power accelerator using an inductive voltage monitor (IVM). Specifically, the IVM was connected to, and thus monitored the voltage at, the bottom level of the accelerators vacuum double post-hole convolute. Additional voltage and current measurements were taken at the accelerators vacuum-insulator stack (at a radius of 1.6 m) by using standard D-dot and B-dot probes, respectively. During postprocessing, the measurements taken at the stack were translated to the location of the IVM measurements by using a lossless propagation model of the Z accelerators magnetically insulated transmission lines (MITLs)moreand a lumped inductor model of the vacuum post-hole convolute. Across a wide variety of experiments conducted on the Z accelerator, the voltage histories obtained from the IVM and the lossless propagation technique agree well in overall shape and magnitude. However, large-amplitude, high-frequency oscillations are more pronounced in the IVM records. It is unclear whether these larger oscillations represent true voltage oscillations at the convolute or if they are due to noise pickup and/or transit-time effects and other resonant modes in the IVM. Results using a transit-time-correction technique and Fourier analysis support the latter. Regardless of which interpretation is correct, both true voltage oscillations and the excitement of resonant modes could be the result of transient electrical breakdowns in the post-hole convolute, though more information is required to determine definitively if such breakdowns occurred. Despite the larger oscillations in the IVM records, the general agreement found between the lossless propagation results and the results of the IVM shows that large voltages are transmitted efficiently through the MITLs on Z. These results are complementary to previous studies [R.D. McBride et al., Phys. Rev. ST Accel. Beams 13, 120401 (2010)] that showed efficient transmission of large currents through the MITLs on Z. Taken together, the two studies demonstrate the overall efficient delivery of very large electrical powers through the MITLs on Z.less

  11. Voltage measurements at the vacuum post-hole convolute of the Z pulsed-power accelerator

    SciTech Connect (OSTI)

    Waisman, E. M.; McBride, R. D.; Cuneo, M. E.; Wenger, D. F.; Fowler, W. E.; Johnson, W. A.; Basilio, L. I.; Coats, R. S.; Jennings, C. A.; Sinars, D. B.; Vesey, R. A.; Jones, B.; Ampleford, D. J.; Lemke, R. W.; Martin, M. R.; Schrafel, P. C.; Lewis, S. A.; Moore, J. K.; Savage, M. E.; Stygar, W. A.

    2014-12-08

    Presented are voltage measurements taken near the load region on the Z pulsed-power accelerator using an inductive voltage monitor (IVM). Specifically, the IVM was connected to, and thus monitored the voltage at, the bottom level of the accelerators vacuum double post-hole convolute. Additional voltage and current measurements were taken at the accelerators vacuum-insulator stack (at a radius of 1.6 m) by using standard D-dot and B-dot probes, respectively. During postprocessing, the measurements taken at the stack were translated to the location of the IVM measurements by using a lossless propagation model of the Z accelerators magnetically insulated transmission lines (MITLs) and a lumped inductor model of the vacuum post-hole convolute. Across a wide variety of experiments conducted on the Z accelerator, the voltage histories obtained from the IVM and the lossless propagation technique agree well in overall shape and magnitude. However, large-amplitude, high-frequency oscillations are more pronounced in the IVM records. It is unclear whether these larger oscillations represent true voltage oscillations at the convolute or if they are due to noise pickup and/or transit-time effects and other resonant modes in the IVM. Results using a transit-time-correction technique and Fourier analysis support the latter. Regardless of which interpretation is correct, both true voltage oscillations and the excitement of resonant modes could be the result of transient electrical breakdowns in the post-hole convolute, though more information is required to determine definitively if such breakdowns occurred. Despite the larger oscillations in the IVM records, the general agreement found between the lossless propagation results and the results of the IVM shows that large voltages are transmitted efficiently through the MITLs on Z. These results are complementary to previous studies [R. D. McBride et al., Phys. Rev. ST Accel. Beams 13, 120401 (2010)] that showed efficient transmission of large currents through the MITLs on Z. Altogether, the two studies demonstrate the overall efficient delivery of very large electrical powers through the MITLs on Z.

  12. Voltage measurements at the vacuum post-hole convolute of the Z pulsed-power accelerator

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Waisman, E. M.; McBride, R. D.; Cuneo, M. E.; Wenger, D. F.; Fowler, W. E.; Johnson, W. A.; Basilio, L. I.; Coats, R. S.; Jennings, C. A.; Sinars, D. B.; et al

    2014-12-08

    Presented are voltage measurements taken near the load region on the Z pulsed-power accelerator using an inductive voltage monitor (IVM). Specifically, the IVM was connected to, and thus monitored the voltage at, the bottom level of the accelerator’s vacuum double post-hole convolute. Additional voltage and current measurements were taken at the accelerator’s vacuum-insulator stack (at a radius of 1.6 m) by using standard D-dot and B-dot probes, respectively. During postprocessing, the measurements taken at the stack were translated to the location of the IVM measurements by using a lossless propagation model of the Z accelerator’s magnetically insulated transmission lines (MITLs)more » and a lumped inductor model of the vacuum post-hole convolute. Across a wide variety of experiments conducted on the Z accelerator, the voltage histories obtained from the IVM and the lossless propagation technique agree well in overall shape and magnitude. However, large-amplitude, high-frequency oscillations are more pronounced in the IVM records. It is unclear whether these larger oscillations represent true voltage oscillations at the convolute or if they are due to noise pickup and/or transit-time effects and other resonant modes in the IVM. Results using a transit-time-correction technique and Fourier analysis support the latter. Regardless of which interpretation is correct, both true voltage oscillations and the excitement of resonant modes could be the result of transient electrical breakdowns in the post-hole convolute, though more information is required to determine definitively if such breakdowns occurred. Despite the larger oscillations in the IVM records, the general agreement found between the lossless propagation results and the results of the IVM shows that large voltages are transmitted efficiently through the MITLs on Z. These results are complementary to previous studies [R. D. McBride et al., Phys. Rev. ST Accel. Beams 13, 120401 (2010)] that showed efficient transmission of large currents through the MITLs on Z. Altogether, the two studies demonstrate the overall efficient delivery of very large electrical powers through the MITLs on Z.« less

  13. Quantum of area {Delta}A=8{pi}l{sub P}{sup 2} and a statistical interpretation of black hole entropy

    SciTech Connect (OSTI)

    Ropotenko, Kostiantyn

    2010-08-15

    In contrast to alternative values, the quantum of area {Delta}A=8{pi}l{sub P}{sup 2} does not follow from the usual statistical interpretation of black hole entropy; on the contrary, a statistical interpretation follows from it. This interpretation is based on the two concepts: nonadditivity of black hole entropy and Landau quantization. Using nonadditivity a microcanonical distribution for a black hole is found and it is shown that the statistical weight of a black hole should be proportional to its area. By analogy with conventional Landau quantization, it is shown that quantization of a black hole is nothing but the Landau quantization. The Landau levels of a black hole and their degeneracy are found. The degree of degeneracy is equal to the number of ways to distribute a patch of area 8{pi}l{sub P}{sup 2} over the horizon. Taking into account these results, it is argued that the black hole entropy should be of the form S{sub bh}=2{pi}{center_dot}{Delta}{Gamma}, where the number of microstates is {Delta}{Gamma}=A/8{pi}l{sub P}{sup 2}. The nature of the degrees of freedom responsible for black hole entropy is elucidated. The applications of the new interpretation are presented. The effect of noncommuting coordinates is discussed.

  14. Recombination of polynucleotide sequences using random or defined primers

    DOE Patents [OSTI]

    Arnold, Frances H. (Pasadena, CA); Shao, Zhixin (Pasadena, CA); Affholter, Joseph A. (Midland, MI); Zhao, Huimin H (San Diego, CA); Giver, Lorraine J. (Sunnyvale, CA)

    2000-01-01

    A method for in vitro mutagenesis and recombination of polynucleotide sequences based on polymerase-catalyzed extension of primer oligonucleotides is disclosed. The method involves priming template polynucleotide(s) with random-sequences or defined-sequence primers to generate a pool of short DNA fragments with a low level of point mutations. The DNA fragments are subjected to denaturization followed by annealing and further enzyme-catalyzed DNA polymerization. This procedure is repeated a sufficient number of times to produce full-length genes which comprise mutants of the original template polynucleotides. These genes can be further amplified by the polymerase chain reaction and cloned into a vector for expression of the encoded proteins.

  15. RANDOM BALLISTIC INTERPRETATION OF NONLINEAR GUIDING CENTER THEORY

    SciTech Connect (OSTI)

    Ruffolo, D.; Pianpanit, T.; Matthaeus, W. H.; Chuychai, P. E-mail: th_ee@hotmail.com E-mail: p.chuychai@sci.mfu.ac.th

    2012-03-10

    Nonlinear guiding center (NLGC) theory has been used to explain the asymptotic perpendicular diffusion coefficient {kappa} of energetic charged particles in a turbulent magnetic field, which can be applied to better understand cosmic ray transport. Here we re-derive NLGC, replacing the assumption of diffusive decorrelation with random ballistic decorrelation (RBD), which yields an explicit formula for {kappa} . We note that scattering processes can cause a reversal of the guiding center motion along the field line, i.e., 'backtracking', leading to partial cancellation of contributions to {kappa}, especially for low-wavenumber components of the magnetic turbulence. We therefore include a heuristic backtracking correction (BC) that can be used in combination with RBD. In comparison with computer simulation results for various cases, NLGC with RBD and BC provides a substantially improved characterization of the perpendicular diffusion coefficient for a fluctuation amplitude less than or equal to the large-scale magnetic field.

  16. Surface wake in the random-phase approximation

    SciTech Connect (OSTI)

    Garcia de Abajo, F.J. ); Echenique, P.M. )

    1993-11-01

    The scalar-electric-potential distribution set up by an ion traveling in the vicinity of a plane solid-vacuum interface, that is, the surface-wake potential, is investigated with the specular-reflection model to describe the response of the surface and with the random-phase approximation for the dielectric function of the bulk material. This permits us to address the study of the low-velocity surface wake: the static potential is found to have a dip at the position of the ion; that dip is shifted towards the direction opposite to the velocity vector for velocities smaller than the threshold of creation of plasmons ([approx]1.3[ital v][sub [ital F

  17. Resonant spin tunneling in randomly oriented nanospheres of Mn?? acetate

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lendinez, S.; Billinge, S. J. L.; Zarzuela, R.; Tejada, J.; Terban, M. W.; Espin, J.; Imaz, I.; Maspoch, D.; Chudnovsky, E. M.

    2015-01-06

    We report measurements and theoretical analysis of resonant spin tunneling in randomly oriented nanospheres of a molecular magnet. Amorphous nanospheres of Mn?? acetate have been fabricated and characterized by chemical, infrared, TEM, X-ray, and magnetic methods. Magnetic measurements have revealed sharp tunneling peaks in the field derivative of the magnetization that occur at the typical resonant field values for the Mn?? acetate crystal in the field parallel to the easy axis.Theoretical analysis is provided that explains these observations. We argue that resonant spin tunneling in a molecular magnet can be established in a powder sample, without the need for amoresingle crystal and without aligning the easy magnetization axes of the molecules. This is confirmed by re-analyzing the old data on a powdered sample of non-oriented micron-size crystals of Mn?? acetate. Our findings can greatly simplify the selection of candidates for quantum spin tunneling among newly synthesized molecular magnets.less

  18. Local random potentials of high differentiability to model the Landscape

    SciTech Connect (OSTI)

    Battefeld, T.; Modi, C.

    2015-03-09

    We generate random functions locally via a novel generalization of Dyson Brownian motion, such that the functions are in a desired differentiability class C{sup k}, while ensuring that the Hessian is a member of the Gaussian orthogonal ensemble (other ensembles might be chosen if desired). Potentials in such higher differentiability classes (k≥2) are required/desirable to model string theoretical landscapes, for instance to compute cosmological perturbations (e.g., k=2 for the power-spectrum) or to search for minima (e.g., suitable de Sitter vacua for our universe). Since potentials are created locally, numerical studies become feasible even if the dimension of field space is large (D∼100). In addition to the theoretical prescription, we provide some numerical examples to highlight properties of such potentials; concrete cosmological applications will be discussed in companion publications.

  19. History dependent quantum random walks as quantum lattice gas automata

    SciTech Connect (OSTI)

    Shakeel, Asif E-mail: dmeyer@math.ucsd.edu Love, Peter J. E-mail: dmeyer@math.ucsd.edu; Meyer, David A. E-mail: dmeyer@math.ucsd.edu

    2014-12-15

    Quantum Random Walks (QRW) were first defined as one-particle sectors of Quantum Lattice Gas Automata (QLGA). Recently, they have been generalized to include history dependence, either on previous coin (internal, i.e., spin or velocity) states or on previous position states. These models have the goal of studying the transition to classicality, or more generally, changes in the performance of quantum walks in algorithmic applications. We show that several history dependent QRW can be identified as one-particle sectors of QLGA. This provides a unifying conceptual framework for these models in which the extra degrees of freedom required to store the history information arise naturally as geometrical degrees of freedom on the lattice.

  20. Recombination of polynucleotide sequences using random or defined primers

    DOE Patents [OSTI]

    Arnold, Frances H. (Pasadena, CA); Shao, Zhixin (Pasadena, CA); Affholter, Joseph A. (Midland, MI); Zhao, Huimin (Pasadena, CA); Giver, Lorraine J. (Pasadena, CA)

    2001-01-01

    A method for in vitro mutagenesis and recombination of polynucleotide sequences based on polymerase-catalyzed extension of primer oligonucleotides is disclosed. The method involves priming template polynucleotide(s) with random-sequences or defined-sequence primers to generate a pool of short DNA fragments with a low level of point mutations. The DNA fragments are subjected to denaturization followed by annealing and further enzyme-catalyzed DNA polymerization. This procedure is repeated a sufficient number of times to produce full-length genes which comprise mutants of the original template polynucleotides. These genes can be further amplified by the polymerase chain reaction and cloned into a vector for expression of the encoded proteins.

  1. Temporal evolution of solar wind ion composition and their source coronal holes during the declining phase of cycle 23. I. Low-latitude extension of polar coronal holes

    SciTech Connect (OSTI)

    Ko, Yuan-Kuen; Wang, Yi-Ming; Muglach, Karin; Young, Peter R.; Lepri, Susan T.

    2014-06-01

    We analyzed 27 solar wind (SW) intervals during the declining phase of cycle 23, whose source coronal holes (CHs) can be unambiguously identified and are associated with one of the polar CHs. We found that the SW ions have a temporal trend of decreasing ionization state, and such a trend is different between the slow and fast SW. The photospheric magnetic field, both inside and at the outside boundary of the CH, also exhibits a trend of decrease with time. However, EUV line emissions from different layers of the atmosphere exhibit different temporal trends. The coronal emission inside the CH generally increases toward the CH boundary as the underlying field increases in strength and becomes less unipolar. In contrast, this relationship is not seen in the coronal emission averaged over the entire CH. For C and O SW ions that freeze-in at lower altitude, stronger correlation between their ionization states and field strength (both signed and unsigned) appears in the slow SW, while for Fe ions that freeze-in at higher altitude, stronger correlation appears in the fast SW. Such correlations are seen both inside the CH and at its boundary region. On the other hand, the coronal electron temperature correlates well with the SW ion composition only in the boundary region. Our analyses, although not able to determine the likely footpoint locations of the SW of different speeds, raise many outstanding questions for how the SW is heated and accelerated in response to the long-term evolution of the solar magnetic field.

  2. High-performance ternary blend polymer solar cells involving both energy transfer and hole relay processes

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lu, Luyao; Chen, Wei; Xu, Tao; Yu, Luping

    2015-06-04

    The integration of multiple materials with complementary absorptions into a single junction device is regarded as an efficient way to enhance the power conversion efficiency (PCE) of organic solar cells (OSCs). However, because of increased complexity with one more component, only limited high-performance ternary systems have been demonstrated previously. Here we report an efficient ternary blend OSC with a PCE of 9.2%. We show that the third component can reduce surface trap densities in the ternary blend. Detailed studies unravel that the improved performance results from synergistic effects of enlarged open circuit voltage, suppressed trap-assisted recombination, enhanced light absorption, increasedmore » hole extraction, efficient energy transfer and better morphology. The working mechanism and high device performance demonstrate new insights and design guidelines for high-performance ternary blend solar cells and suggest that ternary structure is a promising platform to boost the efficiency of OSCs.« less

  3. Small black holes on branes: Is the horizon regular or singular?

    SciTech Connect (OSTI)

    Karasik, D.; Sahabandu, C.; Suranyi, P.; Wijewardhana, L.C.R.

    2004-09-15

    We investigate the following question: Consider a small mass, with {epsilon} (the ratio of the Schwarzschild radius and the bulk curvature length) much smaller than 1, that is confined to the TeV brane in the Randall-Sundrum I scenario. Does it form a black hole with a regular horizon, or a naked singularity? The metric is expanded in {epsilon} and the asymptotic form of the metric is given by the weak field approximation (linear in the mass). In first order of {epsilon} we show that the iteration of the weak field solution, which includes only integer powers of the mass, leads to a solution that has a singular horizon. We find a solution with a regular horizon but its asymptotic expansion in the mass also contains half integer powers.

  4. Radiating black holes in Einstein-Yang-Mills theory and cosmic censorship

    SciTech Connect (OSTI)

    Ghosh, Sushant G.; Dadhich, Naresh

    2010-08-15

    Exact nonstatic spherically symmetric black-hole solutions of the higher dimensional Einstein-Yang-Mills equations for a null dust with Yang-Mills gauge charge are obtained by employing Wu-Yang ansatz, namely, HD-EYM Vaidya solution. It is interesting to note that gravitational contribution of Yang-Mills (YM) gauge charge for this ansatz is indeed opposite (attractive rather than repulsive) that of Maxwell charge. It turns out that the gravitational collapse of null dust with YM gauge charge admits strong curvature shell focusing naked singularities violating cosmic censorship. However, there is significant shrinkage of the initial data space for a naked singularity of the HD-Vaidya collapse due to presence of YM gauge charge. The effect of YM gauge charge on structure and location of the apparent and event horizons is also discussed.

  5. Lithium fluoride injection layers can form quasi-Ohmic contacts for both holes and electrons

    SciTech Connect (OSTI)

    Bory, Benjamin F.; Janssen, Ren A. J.; Meskers, Stefan C. J.; Rocha, Paulo R. F.; Gomes, Henrique L.; De Leeuw, Dago M.

    2014-09-22

    Thin LiF interlayers are typically used in organic light-emitting diodes to enhance the electron injection. Here, we show that the effective work function of a contact with a LiF interlayer can be either raised or lowered depending on the history of the applied bias. Formation of quasi-Ohmic contacts for both electrons and holes is demonstrated by electroluminescence from symmetric LiF/polymer/LiF diodes in both bias polarities. The origin of the dynamic switching is charging of electrically induced Frenkel defects. The current densityelectroluminescencevoltage characteristics can qualitatively be explained. The interpretation is corroborated by unipolar memristive switching and by bias dependent reflection measurements.

  6. Harsh-Environment Solid-State Gamma Detector for Down-hole Gas and Oil Exploration

    SciTech Connect (OSTI)

    Peter Sandvik; Stanislav Soloviev; Emad Andarawis; Ho-Young Cha; Jim Rose; Kevin Durocher; Robert Lyons; Bob Pieciuk; Jim Williams; David O'Connor

    2007-08-10

    The goal of this program was to develop a revolutionary solid-state gamma-ray detector suitable for use in down-hole gas and oil exploration. This advanced detector would employ wide-bandgap semiconductor technology to extend the gamma sensor's temperature capability up to 200 C as well as extended reliability, which significantly exceeds current designs based on photomultiplier tubes. In Phase II, project tasks were focused on optimization of the final APD design, growing and characterizing the full scintillator crystals of the selected composition, arranging the APD device packaging, developing the needed optical coupling between scintillator and APD, and characterizing the combined elements as a full detector system preparing for commercialization. What follows is a summary report from the second 18-month phase of this program.

  7. MACHINING ELIMINATION THROUGH APPLICATION OF THREAD FORMING FASTENERS IN NET SHAPED CAST HOLES

    SciTech Connect (OSTI)

    Cleaver, Ryan J.; Cleaver, Todd H.; Talbott, Richard

    2012-05-02

    The ultimate objective of this work was to eliminate approximately 30% of the machining performed in typical automotive engine and transmission plants by using thread forming fasteners in as-cast holes of aluminum and magnesium cast components. The primary issues at the source of engineers???????????????¢???????????????????????????????? reluctance to implementing thread forming fasteners in lightweight castings are: * Little proof of consistency of clamp load vs. input torque in either aluminum or magnesium castings. * No known data to understand the effect on consistency of clamp load as casting dies wear. The clamp load consistency concern is founded in the fact that a portion of the input torque used to create clamp load is also used to create threads. The torque used for thread forming may not be consistent due to variations in casting material, hole size and shape due to tooling wear and process variation (thermal and mechanical). There is little data available to understand the magnitude of this concern or to form the basis of potential solutions if the range of clamp load variation is very high (> +/- 30%). The range of variation that can be expected in as-cast hole size and shape over the full life cycle of a high pressure die casting die was established in previous work completed by Pacific Northwest National Laboratory, (PNNL). This established range of variation was captured in a set of 12 cast bosses by designing core pins at the size and draft angles identified in the sited previous work. The cast bosses were cut into ???????????????¢????????????????????????????????nuts???????????????¢??????????????????????????????? that could be used in the Ford Fastener Laboratory test-cell to measure clamp load when a thread forming fastener was driven into a cast nut. There were two sets of experiments run. First, a series of cast aluminum nuts were made reflecting the range of shape and size variations to be expected over the life cycle of a die casting die. Taptite thread forming fasteners, (a widely used thread forming fastener suitable for aluminum applications), were driven into the various cored, as-cast nuts at a constant input torque and resulting clamp loads were recorded continuously. The clamp load data was used to determine the range of clamp loads to be expected. The bolts were driven to failure. The clamp load corresponding to the target input of 18.5 Nm was recorded for each fastener. In a like fashion, a second set of experiments were run with cast magnesium nuts and ALtracs thread forming fasteners, (a widely used thread forming fastener suitable for magnesium applications). Again all clamp loads were recorded and analyzed similarly to the Taptites in aluminum cast nuts. Results from previous work performed on the same test cell for a Battelle project using standard M8 bolts into standard M8 nuts were included as a comparator for a standard bolt and nut application. The results for the thread forming fasteners in aluminum cast holes were well within industry expectations of +/- 30% for out of the box and robustness range te

  8. Ultra low injection angle fuel holes in a combustor fuel nozzle

    DOE Patents [OSTI]

    York, William David

    2012-10-23

    A fuel nozzle for a combustor includes a mixing passage through which fluid is directed toward a combustion area and a plurality of swirler vanes disposed in the mixing passage. Each swirler vane of the plurality of swirler vanes includes at least one fuel hole through which fuel enters the mixing passage in an injection direction substantially parallel to an outer surface of the plurality of swirler vanes thereby decreasing a flameholding tendency of the fuel nozzle. A method of operating a fuel nozzle for a combustor includes flowing a fluid through a mixing passage past a plurality of swirler vanes and injecting a fuel into the mixing passage in an injection direction substantially parallel to an outer surface of the plurality of swirler vanes.

  9. High-performance ternary blend polymer solar cells involving both energy transfer and hole relay processes

    SciTech Connect (OSTI)

    Lu, Luyao; Chen, Wei; Xu, Tao; Yu, Luping

    2015-06-04

    The integration of multiple materials with complementary absorptions into a single junction device is regarded as an efficient way to enhance the power conversion efficiency (PCE) of organic solar cells (OSCs). However, because of increased complexity with one more component, only limited high-performance ternary systems have been demonstrated previously. Here we report an efficient ternary blend OSC with a PCE of 9.2%. We show that the third component can reduce surface trap densities in the ternary blend. Detailed studies unravel that the improved performance results from synergistic effects of enlarged open circuit voltage, suppressed trap-assisted recombination, enhanced light absorption, increased hole extraction, efficient energy transfer and better morphology. The working mechanism and high device performance demonstrate new insights and design guidelines for high-performance ternary blend solar cells and suggest that ternary structure is a promising platform to boost the efficiency of OSCs.

  10. Terahertz magneto-optical spectroscopy of a two-dimensional hole gas

    SciTech Connect (OSTI)

    Kamaraju, N. Taylor, A. J.; Prasankumar, R. P.; Pan, W.; Reno, J.; Ekenberg, U.; Gvozdić, D. M.; Boubanga-Tombet, S.; Upadhya, P. C.

    2015-01-19

    Two-dimensional hole gases (2DHGs) have attracted recent attention for their unique quantum physics and potential applications in areas including spintronics and quantum computing. However, their properties remain relatively unexplored, motivating the use of different techniques to study them. We used terahertz magneto-optical spectroscopy to investigate the cyclotron resonance frequency in a high mobility 2DHG, revealing a nonlinear dependence on the applied magnetic field. This is shown to be due to the complex non-parabolic valence band structure of the 2DHG, as verified by multiband Landau level calculations. We also find that impurity scattering dominates cyclotron resonance decay in the 2DHG, in contrast with the dominance of superradiant damping in two-dimensional electron gases. Our results shed light on the properties of 2DHGs, motivating further studies of these unique 2D nanosystems.

  11. Terahertz magneto-optical spectroscopy of a two-dimensional hole gas

    SciTech Connect (OSTI)

    Kamaraju, N.; Pan, W.; Ekenberg, U.; Gvozdić, D. M.; Boubanga-Tombet, S.; Upadhya, P. C.; Reno, J.; Taylor, A. J.; Prasankumar, R. P.

    2015-01-21

    Two-dimensional hole gases (2DHGs) have attracted recent attention for their unique quantum physics and potential applications in areas including spintronics and quantum computing. However, their properties remain relatively unexplored, motivating the use of different techniques to study them. We then used terahertz magneto-optical spectroscopy to investigate the cyclotron resonance frequency in a high mobility 2DHG, revealing a nonlinear dependence on the applied magnetic field. This is shown to be due to the complex non-parabolic valence band structure of the 2DHG, as verified by multiband Landau level calculations. We also found that impurity scattering dominates cyclotron resonance decay in the 2DHG, in contrast with the dominance of superradiant damping in two-dimensional electron gases. Our results shed light on the properties of 2DHGs, motivating further studies of these unique 2D nanosystems.

  12. Terahertz magneto-optical spectroscopy of a two-dimensional hole gas

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kamaraju, N.; Pan, W.; Ekenberg, U.; Gvozdić, D. M.; Boubanga-Tombet, S.; Upadhya, P. C.; Reno, J.; Taylor, A. J.; Prasankumar, R. P.

    2015-01-21

    Two-dimensional hole gases (2DHGs) have attracted recent attention for their unique quantum physics and potential applications in areas including spintronics and quantum computing. However, their properties remain relatively unexplored, motivating the use of different techniques to study them. We then used terahertz magneto-optical spectroscopy to investigate the cyclotron resonance frequency in a high mobility 2DHG, revealing a nonlinear dependence on the applied magnetic field. This is shown to be due to the complex non-parabolic valence band structure of the 2DHG, as verified by multiband Landau level calculations. We also found that impurity scattering dominates cyclotron resonance decay in the 2DHG,more » in contrast with the dominance of superradiant damping in two-dimensional electron gases. Our results shed light on the properties of 2DHGs, motivating further studies of these unique 2D nanosystems.« less

  13. EXTREME CORONAL LINE EMITTERS: TIDAL DISRUPTION OF STARS BY MASSIVE BLACK HOLES IN GALACTIC NUCLEI?

    SciTech Connect (OSTI)

    Wang Tinggui; Zhou Hongyan; Wang Huiyuan; Yang Chenwei; Komossa, S.

    2012-04-20

    Tidal disruption of stars by supermassive black holes at the centers of galaxies is expected to produce unique emission-line signatures, which have not yet been explored adequately. Here we report the discovery of extremely strong coronal lines from [Fe X] up to [Fe XIV] in a sample of seven galaxies (including two recently reported cases), which we interpret as such signatures. This is the first systematic search for objects of this kind, by making use of the immense database of the Sloan Digital Sky Survey. The galaxies, which are non-active as evidenced by the narrow line ratios, show broad emission lines of complex profiles in more than half of the sample. Both the high-ionization coronal lines and the broad lines are fading on timescales of years in objects observed with spectroscopic follow-ups, suggesting their transient nature. Variations of inferred non-stellar continua, which have absolute magnitudes of at least -16 to -18 mag in the g band, are also detected in more than half of the sample. The coronal line emitters reside in sub-L{sub *} disk galaxies (-21.3 < M{sub i} < -18.5) with small stellar velocity dispersions. The sample seems to form two distinct types based on the presence or absence of the [Fe VII] lines, with the latter having relatively low luminosities of [O III], [Fe XI], and the host galaxies. These characteristics can most naturally be understood in the context of transient accretion onto intermediate-mass black holes at galactic centers following tidal disruption of stars in a gas-rich environment. We estimate the incidence of such events to be around 10{sup -5} yr{sup -1} for a galaxy with -21.3 < M{sub i} < -18.5.

  14. Role of chemical reactions of arylamine hole transport materials in operational degradation of organic light-emitting diodes

    SciTech Connect (OSTI)

    Kondakov, Denis Y.

    2008-10-15

    We report that the representative arylamine hole transport materials undergo chemical transformations in operating organic light-emitting diode (OLED) devices. Although the underlying chemical mechanisms are too complex to be completely elucidated, structures of several identified degradation products point at dissociations of relatively weak carbon-nitrogen and carbon-carbon bonds in arylamine molecules as the initiating step. Considering the photochemical reactivities, the bond dissociation reactions of arylamines occur by the homolysis of the lowest singlet excited states formed by recombining charge carriers in the operating OLED device. The subsequent chemical reactions are likely to yield long-lived, stabilized free radicals capable of acting as deep traps--nonradiative recombination centers and fluorescence quenchers. Their presence in the hole transport layer results in irreversible hole trapping and manifests as a positive fixed charge. The extent and localization of chemical transformations in several exemplary devices suggest that the free radical reactions of hole transporting materials, arylamines, can be sufficient to account for the observed luminance efficiency loss and voltage rise in operating OLEDs. The relative bond strengths and excited state energies of OLED materials appear to have a determining effect on the operational stability of OLED devices.

  15. Mineralogy of drill holes J-13, UE-25A No. 1, and USW G-1 at Yucca Mountain, Nevada

    SciTech Connect (OSTI)

    Bish, D.L.; Chipera, S.J.

    1986-09-01

    The mineralogy of drill holes J-13, UE-25A No. 1, and USW G-1 was previously determined using qualitative and semiquantitative techniques, and most of the available data were neither complete nor accurate. New quantitative x-ray diffraction data were obtained for rocks from all three of these drill holes at Yucca Mountain, Nevada. These quantitative analyses employed both external and internal standard x-ray powder diffraction methods and permitted the precise determination of all phases commonly found in the tuffs at Yucca Mountain, including glass and opal-CT. These new data supplant previous analyses and include numerous additional phases. New findings of particular importance include better constraints on the distribution of the more soluble silica polymorphs, cristobalite and opal-CT. Opal-CT was associated solely with clinoptilolite-bearing horizons, and cristobalite disappearance coincided with the appearance of analcime in USW G-1. Unlike previous analyses, we identified significant amounts of smectite in drill hole J-13. We found no evidence to support previous reports of the occurrence of erionite or phillipsite in these drill holes.

  16. Geometry of a naked singularity created by standing waves near a Schwarzschild horizon, and its application to the binary black hole problem

    SciTech Connect (OSTI)

    Mandel, Ilya

    2005-10-15

    The most promising way to compute the gravitational waves emitted by binary black holes (BBHs) in their last dozen orbits, where post-Newtonian techniques fail, is a quasistationary approximation introduced by Detweiler and being pursued by Price and others. In this approximation the outgoing gravitational waves at infinity and downgoing gravitational waves at the holes' horizons are replaced by standing waves so as to guarantee that the spacetime has a helical Killing vector field. Because the horizon generators will not, in general, be tidally locked to the holes' orbital motion, the standing waves will destroy the horizons, converting the black holes into naked singularities that resemble black holes down to near the horizon radius. This paper uses a spherically symmetric, scalar-field model problem to explore in detail the following BBH issues: (i) The destruction of a horizon by the standing waves. (ii) The accuracy with which the resulting naked singularity resembles a black hole. (iii) The conversion of the standing-wave spacetime (with a destroyed horizon) into a spacetime with downgoing waves by the addition of a 'radiation-reaction field'. (iv) The accuracy with which the resulting downgoing waves agree with the downgoing waves of a true black-hole spacetime (with horizon). The model problem used to study these issues consists of a Schwarzschild black hole endowed with spherical standing waves of a scalar field, whose wave frequency and near-horizon energy density are chosen to match those of the standing gravitational waves of the BBH quasistationary approximation. It is found that the spacetime metric of the singular, standing-wave spacetime, and its radiation-reaction-field-constructed downgoing waves are quite close to those for a Schwarzschild black hole with downgoing waves--sufficiently close to make the BBH quasistationary approximation look promising for non-tidally-locked black holes.

  17. PSTD Simulations of Multiple Light Scattering in 3-D Macrocsopic Random

    Office of Scientific and Technical Information (OSTI)

    Media (Journal Article) | SciTech Connect PSTD Simulations of Multiple Light Scattering in 3-D Macrocsopic Random Media Citation Details In-Document Search Title: PSTD Simulations of Multiple Light Scattering in 3-D Macrocsopic Random Media We report a full-vector, three-dimensional, numerical solution of Maxwell's equations for optical propagation within, and scattering by, a random medium of macroscopic dimensions. The total scattering cross-section is determined using the pseudospectral

  18. Modeling and optimizing of the random atomic spin gyroscope drift based on the atomic spin gyroscope

    SciTech Connect (OSTI)

    Quan, Wei; Lv, Lin Liu, Baiqi

    2014-11-15

    In order to improve the atom spin gyroscope's operational accuracy and compensate the random error caused by the nonlinear and weak-stability characteristic of the random atomic spin gyroscope (ASG) drift, the hybrid random drift error model based on autoregressive (AR) and genetic programming (GP) + genetic algorithm (GA) technique is established. The time series of random ASG drift is taken as the study object. The time series of random ASG drift is acquired by analyzing and preprocessing the measured data of ASG. The linear section model is established based on AR technique. After that, the nonlinear section model is built based on GP technique and GA is used to optimize the coefficients of the mathematic expression acquired by GP in order to obtain a more accurate model. The simulation result indicates that this hybrid model can effectively reflect the characteristics of the ASG's random drift. The square error of the ASG's random drift is reduced by 92.40%. Comparing with the AR technique and the GP + GA technique, the random drift is reduced by 9.34% and 5.06%, respectively. The hybrid modeling method can effectively compensate the ASG's random drift and improve the stability of the system.

  19. Bad Estimates as a Function of Exceeding the MCNP Random Number Stride

    SciTech Connect (OSTI)

    Booth, Thomas E.

    2014-05-05

    Examples of bad MCNP estimates resulting from exceeding the MCNP random number stride are given for a simple infinite medium problem.

  20. Application of Random Vibration Theory Methodology for Seismic Soil-Structure Interaction Analysis

    Broader source: Energy.gov [DOE]

    Application of Random Vibration Theory Methodology for Seismic Soil-Structure Interaction Analysis Farhang Ostadan Nan Deng Lisa Anderson Bechtel National, Inc. USDOE NPH Workshop October 2014

  1. A comparison of methods for representing sparsely sampled random quantities.

    SciTech Connect (OSTI)

    Romero, Vicente Jose; Swiler, Laura Painton; Urbina, Angel; Mullins, Joshua

    2013-09-01

    This report discusses the treatment of uncertainties stemming from relatively few samples of random quantities. The importance of this topic extends beyond experimental data uncertainty to situations involving uncertainty in model calibration, validation, and prediction. With very sparse data samples it is not practical to have a goal of accurately estimating the underlying probability density function (PDF). Rather, a pragmatic goal is that the uncertainty representation should be conservative so as to bound a specified percentile range of the actual PDF, say the range between 0.025 and .975 percentiles, with reasonable reliability. A second, opposing objective is that the representation not be overly conservative; that it minimally over-estimate the desired percentile range of the actual PDF. The presence of the two opposing objectives makes the sparse-data uncertainty representation problem interesting and difficult. In this report, five uncertainty representation techniques are characterized for their performance on twenty-one test problems (over thousands of trials for each problem) according to these two opposing objectives and other performance measures. Two of the methods, statistical Tolerance Intervals and a kernel density approach specifically developed for handling sparse data, exhibit significantly better overall performance than the others.

  2. Conditional random fields for pattern recognition applied to structured data

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Burr, Tom; Skurikhin, Alexei

    2015-07-14

    Pattern recognition uses measurements from an input domain, X, to predict their labels from an output domain, Y. Image analysis is one setting where one might want to infer whether a pixel patch contains an object that is “manmade” (such as a building) or “natural” (such as a tree). Suppose the label for a pixel patch is “manmade”; if the label for a nearby pixel patch is then more likely to be “manmade” there is structure in the output domain that can be exploited to improve pattern recognition performance. Modeling P(X) is difficult because features between parts of the modelmore » are often correlated. Therefore, conditional random fields (CRFs) model structured data using the conditional distribution P(Y|X = x), without specifying a model for P(X), and are well suited for applications with dependent features. This paper has two parts. First, we overview CRFs and their application to pattern recognition in structured problems. Our primary examples are image analysis applications in which there is dependence among samples (pixel patches) in the output domain. Second, we identify research topics and present numerical examples.« less

  3. GAUSSIAN RANDOM FIELD: PHYSICAL ORIGIN OF SERSIC PROFILES

    SciTech Connect (OSTI)

    Cen, Renyue

    2014-08-01

    While the Sersic profile family provides adequate fits for the surface brightness profiles of observed galaxies, its physical origin is unknown. We show that if the cosmological density field is seeded by random Gaussian fluctuations, as in the standard cold dark matter model, galaxies with steep central profiles have simultaneously extended envelopes of shallow profiles in the outskirts, whereas galaxies with shallow central profiles are accompanied by steep density profiles in the outskirts. These properties are in accord with those of the Sersic profile family. Moreover, galaxies with steep central profiles form their central regions in smaller denser subunits that possibly merge subsequently, which naturally leads to the formation of bulges. In contrast, galaxies with shallow central profiles form their central regions in a coherent fashion without significant substructure, a necessary condition for disk galaxy formation. Thus, the scenario is self-consistent with respect to the correlation between observed galaxy morphology and the Sersic index. We further predict that clusters of galaxies should display a similar trend, which should be verifiable observationally.

  4. Acceptance sampling using judgmental and randomly selected samples

    SciTech Connect (OSTI)

    Sego, Landon H.; Shulman, Stanley A.; Anderson, Kevin K.; Wilson, John E.; Pulsipher, Brent A.; Sieber, W. Karl

    2010-09-01

    We present a Bayesian model for acceptance sampling where the population consists of two groups, each with different levels of risk of containing unacceptable items. Expert opinion, or judgment, may be required to distinguish between the high and low-risk groups. Hence, high-risk items are likely to be identifed (and sampled) using expert judgment, while the remaining low-risk items are sampled randomly. We focus on the situation where all observed samples must be acceptable. Consequently, the objective of the statistical inference is to quantify the probability that a large percentage of the unsampled items in the population are also acceptable. We demonstrate that traditional (frequentist) acceptance sampling and simpler Bayesian formulations of the problem are essentially special cases of the proposed model. We explore the properties of the model in detail, and discuss the conditions necessary to ensure that required samples sizes are non-decreasing function of the population size. The method is applicable to a variety of acceptance sampling problems, and, in particular, to environmental sampling where the objective is to demonstrate the safety of reoccupying a remediated facility that has been contaminated with a lethal agent.

  5. Conditional random fields for pattern recognition applied to structured data

    SciTech Connect (OSTI)

    Burr, Tom; Skurikhin, Alexei

    2015-07-14

    Pattern recognition uses measurements from an input domain, X, to predict their labels from an output domain, Y. Image analysis is one setting where one might want to infer whether a pixel patch contains an object that is manmade (such as a building) or natural (such as a tree). Suppose the label for a pixel patch is manmade; if the label for a nearby pixel patch is then more likely to be manmade there is structure in the output domain that can be exploited to improve pattern recognition performance. Modeling P(X) is difficult because features between parts of the model are often correlated. Therefore, conditional random fields (CRFs) model structured data using the conditional distribution P(Y|X = x), without specifying a model for P(X), and are well suited for applications with dependent features. This paper has two parts. First, we overview CRFs and their application to pattern recognition in structured problems. Our primary examples are image analysis applications in which there is dependence among samples (pixel patches) in the output domain. Second, we identify research topics and present numerical examples.

  6. What happens to Petrov classification, on horizons of axisymmetric dirty black holes

    SciTech Connect (OSTI)

    Tanatarov, I. V.; Zaslavskii, O. B.

    2014-02-15

    We consider axisymmetric stationary dirty black holes with regular non-extremal or extremal horizons, and compute their on-horizon Petrov types. The Petrov type (PT) in the frame of the observer crossing the horizon can be different from that formally obtained in the usual (but singular in the horizon limit) frame of an observer on a circular orbit. We call this entity the boosted Petrov type (BPT), as the corresponding frame is obtained by a singular boost from the regular one. The PT off-horizon can be more general than PT on-horizon and that can be more general than the BPT on horizon. This is valid for all regular metrics, irrespective of the extremality of the horizon. We analyze and classify the possible relations between the three characteristics and discuss the nature and features of the underlying singular boost. The three Petrov types can be the same only for space-times of PT D and O off-horizon. The mutual alignment of principal null directions and the generator in the vicinity of the horizon is studied in detail. As an example, we also analyze a special class of metrics with utra-extremal horizons (for which the regularity conditions look different from the general case) and compare their off-horizon and on-horizon algebraic structure in both frames.

  7. Numerical simulations of optically thick accretion onto a black hole. II. Rotating flow

    SciTech Connect (OSTI)

    Fragile, P. Chris; Olejar, Ally; Anninos, Peter

    2014-11-20

    In this paper, we report on recent upgrades to our general relativistic radiation magnetohydrodynamics code, Cosmos++, including the development of a new primitive inversion scheme and a hybrid implicit-explicit solver with a more general M {sub 1} closure relation for the radiation equations. The new hybrid solver helps stabilize the treatment of the radiation source terms, while the new closure allows for a much broader range of optical depths to be considered. These changes allow us to expand by orders of magnitude the range of temperatures, opacities, and mass accretion rates, and move a step closer toward our goal of performing global simulations of radiation-pressure-dominated black hole accretion disks. In this work, we test and validate the new method against an array of problems. We also demonstrate its ability to handle super-Eddington, quasi-spherical accretion. Even with just a single proof-of-principle simulation, we already see tantalizing hints of the interesting phenomenology associated with the coupling of radiation and gas in super-Eddington accretion flows.

  8. A large-scale structure at redshift 1.71 in the Lockman Hole

    SciTech Connect (OSTI)

    Henry, J. Patrick; Hasinger, Gnther; Suh, Hyewon; Aoki, Kentaro; Finoguenov, Alexis; Fotopoulou, Sotiria; Salvato, Mara; Tanaka, Masayuki

    2014-01-01

    We previously identified LH146, a diffuse X-ray source in the Lockman Hole, as a galaxy cluster at redshift 1.753. The redshift was based on one spectroscopic value, buttressed by seven additional photometric redshifts. We confirm here the previous spectroscopic redshift and present concordant spectroscopic redshifts for an additional eight galaxies. The average of these nine redshifts is 1.714 0.012 (error on the mean). Scrutiny of the galaxy distribution in redshift space and the plane of the sky shows that there are two concentrations of galaxies near the X-ray source. In addition, there are three diffuse X-ray sources spread along the axis connecting the galaxy concentrations. LH146 is one of these three and lies approximately at the center of the two galaxy concentrations and the outer two diffuse X-ray sources. We thus conclude that LH146 is at the redshift initially reported but it is not a single virialized galaxy cluster, as previously assumed. Rather, it appears to mark the approximate center of a larger region containing more objects. For brevity, we refer to all these objects and their alignments as a large-scale structure. The exact nature of LH146 itself remains unclear.

  9. Quantum singularities in (2+1) dimensional matter coupled black hole spacetimes

    SciTech Connect (OSTI)

    Unver, O.; Gurtug, O.

    2010-10-15

    Quantum singularities considered in the 3D Banados-Teitelboim-Zanelli (BTZ) spacetime by Pitelli and Letelier [Phys. Rev. D 77, 124030 (2008)] is extended to charged BTZ and 3D Einstein-Maxwell-dilaton gravity spacetimes. The occurrence of naked singularities in the Einstein-Maxwell extension of the BTZ spacetime both in linear and nonlinear electrodynamics as well as in the Einstein-Maxwell-dilaton gravity spacetimes are analyzed with the quantum test fields obeying the Klein-Gordon and Dirac equations. We show that with the inclusion of the matter fields, the conical geometry near r=0 is removed and restricted classes of solutions are admitted for the Klein-Gordon and Dirac equations. Hence, the classical central singularity at r=0 turns out to be quantum mechanically singular for quantum particles obeying the Klein-Gordon equation but nonsingular for fermions obeying the Dirac equation. Explicit calculations reveal that the occurrence of the timelike naked singularities in the considered spacetimes does not violate the cosmic censorship hypothesis as far as the Dirac fields are concerned. The role of horizons that clothes the singularity in the black hole cases is replaced by repulsive potential barrier against the propagation of Dirac fields.

  10. Low impedance z-pinch drivers without post-hole convolute current adders.

    SciTech Connect (OSTI)

    Savage, Mark Edward; Seidel, David Bruce; Mendel, Clifford Will, Jr.

    2009-09-01

    Present-day pulsed-power systems operating in the terawatt regime typically use post-hole convolute current adders to operate at sufficiently low impedance. These adders necessarily involve magnetic nulls that connect the positive and negative electrodes. The resultant loss of magnetic insulation results in electron losses in the vicinity of the nulls that can severely limit the efficiency of the delivery of the system's energy to a load. In this report, we describe an alternate transformer-based approach to obtaining low impedance. The transformer consists of coils whose windings are in parallel rather than in series, and does not suffer from the presence of magnetic nulls. By varying the pitch of the coils windings, the current multiplication ratio can be varied, leading to a more versatile driver. The coupling efficiency of the transformer, its behavior in the presence of electron flow, and its mechanical strength are issues that need to be addressed to evaluate the potential of transformer-based current multiplication as a viable alternative to conventional current adder technology.

  11. NUCLEOSYNTHESIS CONSTRAINTS ON THE NEUTRON STAR-BLACK HOLE MERGER RATE

    SciTech Connect (OSTI)

    Bauswein, A. [Department of Physics, Aristotle University of Thessaloniki, GR-54124 Thessaloniki (Greece); Ardevol Pulpillo, R.; Janka, H.-T. [Max Planck Institute for Astrophysics, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany); Goriely, S., E-mail: bauswein@MPA-Garching.MPG.DE [Institut d'Astronomie et d'Astrophysique, Universit Libre de Bruxelles, C.P. 226, B-1050 Brussels (Belgium)

    2014-11-01

    We derive constraints on the time-averaged event rate of neutron star-black hole (NS-BH) mergers by using estimates of the population-integrated production of heavy rapid neutron-capture (r-process) elements with nuclear mass numbers A > 140 by such events in comparison to the Galactic repository of these chemical species. Our estimates are based on relativistic hydrodynamical simulations convolved with theoretical predictions of the binary population. This allows us to determine a strict upper limit of the average NS-BH merger rate of ?6 10{sup 5} per year. We quantify the uncertainties of this estimate to be within factors of a few mostly because of the unknown BH spin distribution of such systems, the uncertain equation of state of NS matter, and possible errors in the Galactic content of r-process material. Our approach implies a correlation between the merger rates of NS-BH binaries and of double NS systems. Predictions of the detection rate of gravitational-wave signals from such compact object binaries by Advanced LIGO and Advanced Virgo on the optimistic side are incompatible with the constraints set by our analysis.

  12. Luminescence of non-bridging oxygen hole centers in crystalline SiO{sub 2}

    SciTech Connect (OSTI)

    Skuja, Linards, E-mail: skuja@latnet.lv; Grube, Jurgis [Institute of Solid-State Physics, University of Latvia. Kengaraga iela 8, LV1063 Riga (Latvia); Kajihara, Koichi, E-mail: kkaji@tmu.ac.jp [Department of Applied Chemistry, Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397 (Japan); Hosono, Hideo [Materials and Structures Laboratory and Frontier Research Center, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503 (Japan)

    2014-10-21

    Oxygen dangling bonds (nonbridging oxygen hole centers, NBOHCs), which are characteristic to amorphous SiO{sub 2}, were studied in amorphized regions of neutron-irradiated ?-quartz crystal and on their boundaries by time-resolved site-selective photoluminescence (PL) at 20K. Along with the usual disorder-broadened PL band of NBOHCs, sharp, 'crystal-like' zero-phonon lines (ZPLs), whose positions do not shift with the excitation wavelength, are observed. In addition to the previously reported NBOHCs with ZPL at 1.933 eV, a second sub-type of NBOHCs with ZPL at 1.883 eV is confirmed by observation of its vibrational sideband due to Si-(dangling O) stretching mode (897cm{sup ?1}) under resonance 1.883eV excitation. A third sub-type of NBOHCs with an excitation energy at 1.879 eV, distinguished by a strong coupling to low-energy (66 cm{sup ?1}) vibrational mode is found. This mode is weakly coupled also to the other two sub-types of NBOHCs.

  13. A tidal disruption event in a nearby galaxy hosting an intermediate mass black hole

    SciTech Connect (OSTI)

    Donato, D.; Troja, E.; Pursimo, T.; Cheung, C. C.; Kutyrev, A.; Landt, H.; Butler, N. R.

    2014-02-01

    We report the serendipitous discovery of a bright point source flare in the Abell cluster A1795 with archival EUVE and Chandra observations. Assuming the EUVE emission is associated with the Chandra source, the X-ray 0.5-7 keV flux declined by a factor of ?2300 over a time span of 6 yr, following a power-law decay with index ?2.44 0.40. The Chandra data alone vary by a factor of ?20. The spectrum is well fit by a blackbody with a constant temperature of kT ? 0.09 keV (?10{sup 6} K). The flare is spatially coincident with the nuclear region of a faint, inactive galaxy with a photometric redshift consistent at the 1? level with the cluster (z = 0.062476). We argue that these properties are indicative of a tidal disruption of a star by a black hole (BH) with log (M {sub BH}/M {sub ?}) ? 5.5 0.5. If so, such a discovery indicates that tidal disruption flares may be used to probe BHs in the intermediate mass range, which are very difficult to study by other means.

  14. Spatially separated charge densities of electrons and holes in organic-inorganic halide perovskites

    SciTech Connect (OSTI)

    Li, Dan; Liang, Chunjun E-mail: zhqhe@bjtu.edu.cn; Zhang, Huimin; You, Fangtian; He, Zhiqun E-mail: zhqhe@bjtu.edu.cn; Zhang, Chunxiu

    2015-02-21

    Solution-processable methylammonium lead trihalide perovskites exhibit remarkable high-absorption and low-loss properties for solar energy conversion. Calculation from density functional theory indicates the presence of non-equivalent halogen atoms in the unit cell because of the specific orientation of the organic cation. Considering the ?100? orientation as an example, I{sub 1}, one of the halogen atoms, differs from the other iodine atoms (I{sub 2} and I{sub 3}) in terms of its interaction with the organic cation. The valance-band-maximum (VBM) and conduction-band-minimum (CBM) states are derived mainly from 5p orbital of I{sub 1} atom and 6p orbital of Pb atom, respectively. The spatially separated charge densities of the electrons and holes justify the low recombination rate of the pure iodide perovskite. Chlorine substitution further strengthens the unique position of the I{sub 1} atom, leading to more localized charge density around the I{sub 1} atom and less charge density around the other atoms at the VBM state. The less overlap of charge densities between the VBM and CBM states explains the relatively lower carrier recombination rate of the iodine-chlorine mixed perovskite. Chlorine substitution significantly reduces the effective mass at a direction perpendicular to the Pb-Cl bond and organic axis, enhancing the carrier transport property of the mixed perovskite in this direction.

  15. A Built for Purpose Micro-Hole Coiled Tubing Rig (MCTR)

    SciTech Connect (OSTI)

    Bart Patton

    2007-09-30

    This report will serve as the final report on the work performed from the contract period October 2005 thru April 2007. The project 'A Built for Purpose Microhole Coiled Tubing Rig (MCTR)' purpose was to upgrade an existing state-of-the-art Coiled Tubing Drilling Rig to a Microhole Coiled Tubing Rig (MCTR) capable of meeting the specifications and tasks of the Department of Energy. The individual tasks outlined to meet the Department of Energy's specifications are: (1) Concept and development of lubricator and tool deployment system; (2) Concept and development of process control and data acquisition; (3) Concept and development of safety and efficiency improvements; and (4) Final unit integration and testing. The end result of the MCTR upgrade has produced a unit capable of meeting the following requirements: (1) Capable of handling 1-inch through 2-3/8-inch coiled tubing (Currently dressed for 2-3/8-inch coiled tubing and capable of running up to 3-1/2-inch coiled tubing); (2) Capable of drilling and casing surface, intermediate, production and liner hole intervals; (3) Capable of drilling with coiled tubing and has all controls and installation piping for a top drive; (4) Rig is capable of running 7-5/8-inch range 2 casing; and (5) Capable of drilling 5,000 ft true vertical depth (TVD) and 6,000 ft true measured depth (TMD).

  16. TIME EVOLUTION OF FLARES IN GRB 130925A: JET PRECESSION IN A BLACK HOLE ACCRETION SYSTEM

    SciTech Connect (OSTI)

    Hou, Shu-Jin; Liu, Tong; Gu, Wei-Min; Sun, Mou-Yuan; Lu, Ju-Fu [Department of Astronomy and Institute of Theoretical Physics and Astrophysics, Xiamen University, Xiamen, Fujian 361005 (China); Lin, Da-Bin [Department of Physics and GXU-NAOC Center for Astrophysics and Space Sciences, Guangxi University, Nanning, Guangxi 530004 (China); Wu, Xue-Feng, E-mail: tongliu@xmu.edu.cn [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

    2014-01-20

    GRB 130925A, composed of three gamma-ray emission episodes and a series of orderly flares, has been detected by Swift, Fermi, Konus-Wind, and INTEGRAL. If the third weakest gamma-ray episode can be considered a giant flare, we find that after the second gamma-ray episode observed by INTEGRAL located at about 2000s, a positive relation exists between the time intervals of the adjacent flares and the time since the episode. We suggest that the second gamma-ray episode and its flares originate from the resumption of the accretion process due to the fragments from the collapsar falling back; such a relation may be related to a hyperaccretion disk around a precessed black hole (BH). We propose that the origin and time evolution of the flares, and the approximately symmetrical temporal structure and spectral evolution of the single flare can be explained well by a jet precession model. In addition, the mass and spin of the BH can be constrained, which indicates a stellar-mass, fast-rotating BH located in the center of GRB 130925A.

  17. Cable Effects Study. Tangents, Rabbit Holes, Dead Ends, and Valuable Results

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ardelean, Emil V.; Babuška, Vít; Goodding, James C.; Coombs, Douglas M.; Robertson, Lawrence M.; Lane, Steven A.

    2014-08-04

    Lessons learned during a study on the effects that electrical power and signal wiring harness cables introduce on the dynamic response of precision spacecraft is presented, along with the most significant results. Our study was a three year effort to discover a set of practical approaches for updating well-defined dynamic models of harness-free structures where knowledge of the cable type, position, and tie-down method are known. Although cables are found on every satellite, the focus was on precision, low damping, and very flexible structures. Obstacles encountered, classified as tangents, rabbit holes, and dead ends, offer practical lessons for structural dynamicsmore » research. The paper traces the historical, experiential progression of the project, describing how the obstacles affected the project. Methods were developed to estimate cable properties. Problems were encountered because of the flexible, highly damped nature of cables. A beam was used as a test article to validate experimentally derived cable properties and to refine the assumptions regarding boundary conditions. Furthermore, a spacecraft bus-like panel with cables attached was designed, and finite element models were developed and validated through experiment. Various paths were investigated at each stage before a consistent test and analysis methodology was developed« less

  18. Understanding the role of electron and hole trions on current transport in aluminium tris(8-hydroxyquinoline) using organic magnetoresistance

    SciTech Connect (OSTI)

    Zhang, Sijie; Gillin, W. P., E-mail: w.gillin@qmul.ac.uk [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Materials Research Institute and School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Willis, M. [College of Physical Science and Technology, Sichuan University, Chengdu 610064 (China); Gotto, R.; Roy, K. A.; Kreouzis, T. [Materials Research Institute and School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Rolfe, N. J. [Materials Research Institute and School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); University of Surrey, Guildford, Surrey GU2 5XH (United Kingdom)

    2014-01-27

    The change in current through an organic light emitting diode (OLED) when it is placed in a magnetic field has been dubbed organic magnetoresistance and provides a means to understand the spin interactions that are occurring in working devices. Whilst there are a wide range of interactions that have been proposed to be the cause of the measured effects, there is still a need to identify their individual roles and in particular how they respond to an applied magnetic field. In this work, we investigate the effect of changing the balance of electron and hole injection in a simple aluminium tris(8-hydroxyqinoline) based OLED and demonstrate that the triplet polaron interaction appears to be much stronger for electrons than for holes in this material.

  19. Schottky barrier height reduction for holes by Fermi level depinning using metal/nickel oxide/silicon contacts

    SciTech Connect (OSTI)

    Islam, Raisul, E-mail: raisul@stanford.edu; Shine, Gautam; Saraswat, Krishna C. [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States)

    2014-11-03

    We report the experimental demonstration of Fermi level depinning using nickel oxide (NiO) as the insulator material in metal-insulator-semiconductor (M-I-S) contacts. Using this contact, we show less than 0.1?eV barrier height for holes in platinum/NiO/silicon (Pt/NiO/p-Si) contact. Overall, the pinning factor was improved from 0.08 (metal/Si) to 0.26 (metal/NiO/Si). The experimental results show good agreement with that obtained from theoretical calculation. NiO offers high conduction band offset and low valence band offset with Si. By reducing Schottky barrier height, this contact can be used as a carrier selective contact allowing hole transport but blocking electron transport, which is important for high efficiency in photonic applications such as photovoltaics and optical detectors.

  20. CONSTRAINTS ON COMPTON-THICK WINDS FROM BLACK HOLE ACCRETION DISKS: CAN WE SEE THE INNER DISK?

    SciTech Connect (OSTI)

    Reynolds, Christopher S.

    2012-11-01

    Strong evidence is emerging that winds can be driven from the central regions of accretion disks in both active galactic nuclei and Galactic black hole binaries. Direct evidence for highly ionized, Compton-thin inner-disk winds comes from observations of blueshifted (v {approx} 0.05-0.1c) iron-K X-ray absorption lines. However, it has been suggested that the inner regions of black hole accretion disks can also drive Compton-thick winds-such winds would enshroud the inner disk, preventing us from seeing direct signatures of the accretion disk (i.e., the photospheric thermal emission, or the Doppler/gravitationally broadened iron K{alpha} line). Here, we show that, provided the source is sub-Eddington, the well-established wind-driving mechanisms fail to launch a Compton-thick wind from the inner disk. For the accelerated region of the wind to be Compton-thick, the momentum carried in the wind must exceed the available photon momentum by a factor of at least 2/{lambda}, where {lambda} is the Eddington ratio of the source, ruling out radiative acceleration unless the source is very close to the Eddington limit. Compton-thick winds also carry large mass fluxes, and a consideration of the connections between the wind and the disk shows this to be incompatible with magneto-centrifugal driving. Finally, thermal driving of the wind is ruled out on the basis of the large Compton radii that typify black hole systems. In the absence of some new acceleration mechanisms, we conclude that the inner regions of sub-Eddington accretion disks around black holes are indeed naked.

  1. Fracture-coating minerals in the Topopah Spring Member and upper tuff of Calico Hills from drill hole J-13

    SciTech Connect (OSTI)

    Carlos, B.

    1989-02-01

    Fracture-lining minerals from drill core in the Topopah Spring Member of the Paintbrush Tuff and the tuff of Calico Hills from water well J-13 were studied to identify the differences between these minerals and those seen in drill core USW G-4. In USW G-4 the static water level (SWL) occurs below the tuff of Calico Hills, but in J-13 the water table is fairly high in the Topopah Spring Member. There are some significant differences in fracture minerals between these two holes. In USW G-4 mordenite is a common fracture-lining mineral in the Topopah Spring Member, increasing in abundance with depth. Euhedral heulandite >0.1 mm in length occurs in fractures for about 20 m above the lower vitrophyre. In J-13, where the same stratigraphic intervals are below the water table, mordenite is uncommon and euhedral heulandite is not seen. The most abundant fracture coating in the Topopah Spring Member in J-13 is drusy quartz, which is totally absent in this interval in USW G-4. Though similar in appearance, the coatings in the vitrophyre have different mineralogy in the two holes. In USW G-4 the coatings are extremely fine grained heulandite and smectite. In J-13 the coatings are fine-grained heulandite, chabazite, and alkali feldspar. Chabazite has not been identified from any other hole in the Yucca Mountain area. Fractures in the tuff of Calico Hills have similar coatings in core from both holes. In J-13, as in USW G-4, the tuff matrix of the Topopah Spring Member is welded and devitrified and that of the tuff of Calico Hills is zeolitic. 11 refs., 10 figs., 5 tabs.

  2. In what sense a neutron star-black hole binary is the holy grail for testing gravity?

    SciTech Connect (OSTI)

    Bagchi, Manjari; Torres, Diego F. E-mail: dtorres@ieec.uab.es

    2014-08-01

    Pulsars in binary systems have been very successful to test the validity of general relativity in the strong field regime [1-4]. So far, such binaries include neutron star-white dwarf (NS-WD) and neutron star-neutron star (NS-NS) systems. It is commonly believed that a neutron star-black hole (NS-BH) binary will be much superior for this purpose. But in what sense is this true? Does it apply to all possible deviations?.

  3. Weak-coupling of the neutron hole in {sup 207}Pb to dipole excitations of {sup 208}Pb

    SciTech Connect (OSTI)

    Fritzsche, M.; Pietralla, N.; Savran, D.; Zweidinger, M.; Ahmed, M. W.; Rusev, G.; Tonchev, A. P.; Weller, H. R.

    2009-01-28

    With the nearly monochromatic, linearly polarized photon beam at the High Intensity {gamma}-ray source (HI{gamma}S) at DFELL photon scattering experiments on {sup 206,207,208}pb have been performed. With these experiments Pb({yields}{gamma},{gamma}') photon scattering reactions could be used to determine spin and parity quantum numbers and therefore study the v(3p{sub 1/2}{sup -1}-hole coupling of {sup 207}Pb to dipole excitations in {sup 208}Pb.

  4. Imaging the supermassive black hole shadow and jet base of M87 with the event horizon telescope

    SciTech Connect (OSTI)

    Lu, Ru-Sen; Fish, Vincent L.; Doeleman, Sheperd S.; Pankratius, Victor; Broderick, Avery E.; Baron, Fabien; Monnier, John D.

    2014-06-20

    The Event Horizon Telescope (EHT) is a project to assemble a Very Long Baseline Interferometry (VLBI) network of millimeter wavelength dishes that can resolve strong field general relativistic signatures near a supermassive black hole. As planned, the EHT will include enough dishes to enable imaging of the predicted black hole 'shadow', a feature caused by severe light bending at the black hole boundary. The center of M87, a giant elliptical galaxy, presents one of the most interesting EHT targets as it exhibits a relativistic jet, offering the additional possibility of studying jet genesis on Schwarzschild radius scales. Fully relativistic models of the M87 jet that fit all existing observational constraints now allow horizon-scale images to be generated. We perform realistic VLBI simulations of M87 model images to examine the detectability of the black shadow with the EHT, focusing on a sequence of model images with a changing jet mass load radius. When the jet is launched close to the black hole, the shadow is clearly visible both at 230 and 345 GHz. The EHT array with a resolution of 20-30 ?as resolution (?2-4 Schwarzschild radii) is able to image this feature independent of any theoretical models and we show that imaging methods used to process data from optical interferometers are applicable and effective for EHT data sets. We demonstrate that the EHT is also capable of tracing real-time structural changes on a few Schwarzschild radii scales, such as those implicated by very high-energy flaring activity of M87. While inclusion of ALMA in the EHT is critical for shadow imaging, the array is generally robust against loss of a station.

  5. Complete multiwavelength evolution of Galactic black hole transients during outburst decay. I. Conditions for 'compact' jet formation

    SciTech Connect (OSTI)

    Kalemci, E.; Diner, T.; Chun, Y. Y.; Tomsick, J. A.; Buxton, M. M.; Bailyn, C. D.

    2013-12-20

    Compact, steady jets are observed in the near infrared and radio bands in the hard state of Galactic black hole transients as their luminosity decreases and the source moves toward a quiescent state. Recent radio observations indicate that the jets turn off completely in the soft state; therefore, multiwavelength monitoring of black hole transients is essential to probe the formation of jets. In this work, we conducted a systematic study of all black hole transients with near infrared and radio coverage during their outburst decays. We characterized the timescales of changes in X-ray spectral and temporal properties and also in near infrared and/or in radio emission. We confirmed that state transitions occur in black hole transients at a very similar fraction of their respective Eddington luminosities. We also found that the near infrared flux increase that could be due to the formation of a compact jet is delayed by a time period of days with respect to the formation of a corona. Finally, we found a threshold disk Eddington luminosity fraction for the compact jets to form. We explain these results with a model such that the increase in the near infrared flux corresponds to a transition from a patchy, small-scale height corona along with an optically thin outflow to a large-scale height corona that allows for collimation of a steady compact jet. We discuss the timescale of jet formation in terms of transport of magnetic fields from the outer parts of the disk, and we also consider two alternative explanations for the multiwavelength emission: hot inner accretion flows and irradiation.

  6. Response I-1: The "holes" in the Long-Term Stewardship (LTS) Plan referred t

    Office of Legacy Management (LM)

    Response I-1: The "holes" in the Long-Term Stewardship (LTS) Plan referred to details of stewardship activities that have not been resolved, such as institutional controls for the Ground Water Operable Unit at the site and the restrictive easements and other legal instruments associated with institutional controls. Radioactive materials and other wastes (e.g. asbestos) have been remediated and encapsulated in the disposal cell in accordance with approved Records of Decision that were

  7. Geologic Characterization of Young Alluvial Basin-Fill Deposits from Drill Hole Data in Yucca Flat, Nye County, Nevada.

    SciTech Connect (OSTI)

    Donald S. Sweetkind; Ronald M. Drake II

    2007-01-22

    Yucca Flat is a topographic and structural basin in the northeastern part of the Nevada Test Site (NTS) in Nye County, Nevada, that has been the site of numerous underground nuclear tests; many of these tests occurred within the young alluvial basin-fill deposits. The migration of radionuclides to the Paleozoic carbonate aquifer involves passage through this thick, heterogeneous section of Tertiary and Quaternary rock. An understanding of the lateral and vertical changes in the material properties of young alluvial basin-fill deposits will aid in the further development of the hydrogeologic framework and the delineation of hydrostratigraphic units and hydraulic properties required for simulating ground-water flow in the Yucca Flat area. This report by the U.S. Geological Survey, in cooperation with the U.S. Department of Energy, presents data and interpretation regarding the three-dimensional variability of the shallow alluvial aquifers in areas of testing at Yucca Flat, data that are potentially useful in the understanding of the subsurface flow system. This report includes a summary and interpretation of alluvial basin-fill stratigraphy in the Yucca Flat area based on drill hole data from 285 selected drill holes. Spatial variations in lithology and grain size of the Neogene basin-fill sediments can be established when data from numerous drill holes are considered together. Lithologic variations are related to different depositional environments within the basin including alluvial fan, channel, basin axis, and playa deposits.

  8. Hole-induced insulator-to-metal transition in La1-xSrxCrO3 epitaxial films

    SciTech Connect (OSTI)

    Zhang, Hongliang; Du, Yingge; Sushko, Petr; Bowden, Mark E.; Shutthanandan, V.; Sallis, Shawn; Piper, Louis F. J.; Chambers, Scott A.

    2015-04-01

    We have investigated the evolution of the structural and electronic properties of La1-xSrxCrO3 (0 ? x ? 1) epitaxial films deposited by molecular beam epitaxy (MBE) using x-ray diffraction, x-ray photoemission spectroscopy, x-ray absorption spectroscopy, electrical transport, and ab initio modeling. LaCrO3 is an antiferromagnetic Mott insulator whereas stoichiometric SrCrO3 is a metal. Substituting Sr2+ for La3+ in LaCrO3 effectively dopes holes into the top of valence band, leading to Cr4+ (3d2) local electron configurations. Core-level and valence-band features monotonically shift to lower binding energy with increasing x, indicating downward movement of the Fermi level toward the valence band maximum. An insulator-to-metal like transition is observed at x ? 0. 65 even as the material becomes a p-type semiconductor at lower doping level and eventually becomes degenerately doped. Valence band x-ray photoemission spectroscopy reveals diminution of electronic state density at the top of the valence band while O K-edge x-ray absorption spectroscopy shows the development of a new unoccupied state above the Fermi level as holes are doped into LaCrO3. These results indicate a pronounced redistribution of electronic state density of states upon hole doping, a result that is also obtained by density functional theory with a Hubbard U correction.

  9. IS THERE AN INTERMEDIATE MASSIVE BLACK HOLE IN THE GALACTIC CENTER: IMPRINTS ON THE STELLAR TIDAL-DISRUPTION RATE

    SciTech Connect (OSTI)

    Chen, Xian; Liu, F. K. E-mail: fkliu@pku.edu.cn

    2013-01-10

    It has been suggested that an intermediate-massive black hole (IMBH) with mass 10{sup 3-5} M {sub Sun} could fall into the galactic center (GC) and form a massive black hole binary (MBHB) with the central supermassive black hole, but current observations are not sensitive to constrain all mass and distance ranges. Motivated by the recent discovery that MBHBs could enhance the rate of tidal-disruption events (TDEs) of stellar objects, we investigate the prospect of using stellar-disruption rate to probe IMBHs in the GC. We incorporated the perturbation by an IMBH into the loss-cone theory and calculated the stellar-disruption rates in the GC. We found that an IMBH heavier than 2000 M {sub Sun} could distinguishably enhance the stellar-disruption rate. By comparing observations of Sgr A* with the fall-back model for stellar debris, we suggested that the TDE rate in our Galaxy should not significantly exceed 0.002 yr{sup -1}, therefore a fraction of the parameter space for the IMBH, concentrating at the high-mass end, can already be excluded. To derive constraint in the remaining parameter space, it is crucial to observationally confirm or reject the stellar-disruption rate between 10{sup -4} and 10{sup -2} yr{sup -1}, and we discussed possible strategies to make such measurements.

  10. Low-Cost Nano-Patterning Process Makes Millions of Holes in Silver Film, Boosting Light-Capturing Qualities of Solar Cells (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2011-02-01

    NREL researchers have demonstrated a simple, low-cost way to pattern nano-sized holes in thin silver films in order to trap light waves and boost the transmission of photons into usable energy.

  11. Offset active galactic nuclei as tracers of galaxy mergers and supermassive black hole growth

    SciTech Connect (OSTI)

    Comerford, Julia M.; Greene, Jenny E.

    2014-07-10

    Offset active galactic nuclei (AGNs) are AGNs that are in ongoing galaxy mergers, which produce kinematic offsets in the AGNs relative to their host galaxies. Offset AGNs are also close relatives of dual AGNs. We conduct a systematic search for offset AGNs in the Sloan Digital Sky Survey by selecting AGN emission lines that exhibit statistically significant line-of-sight velocity offsets relative to systemic. From a parent sample of 18,314 Type 2 AGNs at z < 0.21, we identify 351 offset AGN candidates with velocity offsets of 50 km s{sup 1} < |?v| < 410 km s{sup 1}. When we account for projection effects in the observed velocities, we estimate that 4%-8% of AGNs are offset AGNs. We designed our selection criteria to bypass velocity offsets produced by rotating gas disks, AGN outflows, and gravitational recoil of supermassive black holes, but follow-up observations are still required to confirm our candidates as offset AGNs. We find that the fraction of AGNs that are offset candidates increases with AGN bolometric luminosity, from 0.7% to 6% over the luminosity range 43 < log (L{sub bol}) [erg s{sup 1}] <46. If these candidates are shown to be bona fide offset AGNs, then this would be direct observational evidence that galaxy mergers preferentially trigger high-luminosity AGNs. Finally, we find that the fraction of AGNs that are offset AGN candidates increases from 1.9% at z = 0.1 to 32% at z = 0.7, in step with the growth in the galaxy merger fraction over the same redshift range.

  12. ENHANCED OFF-CENTER STELLAR TIDAL DISRUPTIONS BY SUPERMASSIVE BLACK HOLES IN MERGING GALAXIES

    SciTech Connect (OSTI)

    Liu, F. K.; Chen, Xian E-mail: chenxian@pku.edu.cn

    2013-04-10

    Off-center stellar tidal disruption flares have been suggested to be a powerful probe of recoiling supermassive black holes (SMBHs) out of galactic centers due to anisotropic gravitational wave radiations. However, off-center tidal flares can also be produced by SMBHs in merging galaxies. In this paper, we computed the tidal flare rates by dual SMBHs in two merging galaxies before the SMBHs become self-gravitationally bounded. We employ an analytical model to calculate the tidal loss-cone feeding rates for both SMBHs, taking into account two-body relaxation of stars, tidal perturbations by the companion galaxy, and chaotic stellar orbits in triaxial gravitational potential. We show that for typical SMBHs with masses 10{sup 7} M{sub Sun }, the loss-cone feeding rates are enhanced by mergers up to {Gamma} {approx} 10{sup -2} yr{sup -1}, about two orders of magnitude higher than those by single SMBHs in isolated galaxies and about four orders of magnitude higher than those by recoiling SMBHs. The enhancements are mainly due to tidal perturbations by the companion galaxy. We suggest that off-center tidal flares are overwhelmed by those from merging galaxies, making the identification of recoiling SMBHs challenging. Based on the calculated rates, we estimate the relative contributions of tidal flare events by single, binary, and dual SMBH systems during cosmic time. Our calculations show that the off-center tidal disruption flares by un-bound SMBHs in merging galaxies contribute a fraction comparable to that by single SMBHs in isolated galaxies. We conclude that off-center tidal disruptions are powerful tracers of the merging history of galaxies and SMBHs.

  13. Doping against the native propensity of MoS₂: Degenerate hole doping by cation substitution

    SciTech Connect (OSTI)

    Suh, Joonki; Park, Tae-Eon; Lin, Der-Yuh; Fu, Deyi; Park, Joonsuk; Jung, Hee Joon; Chen, Yabin; Ko, Changhyun; Jang, Chaun; Sun, Yinghui; Sinclair, Robert; Chang, Joonyeon; Tongay, Sefaattin; Wu, Junqiao

    2014-12-10

    Layered transition metal dichalcogenides (TMDs) draw much attention as the key semiconducting material for two-dimensional electrical, optoelectronic, and spintronic devices. For most of these applications, both n- and p-type materials are needed to form junctions and support bipolar carrier conduction. However, typically only one type of doping is stable for a particular TMD. For example, molybdenum disulfide (MoS₂) is natively an n-type presumably due to omnipresent electron-donating sulfur vacancies, and stable/controllable p-type doping has not been achieved. The lack of p-type doping hampers the development of charge-splitting p–n junctions of MoS₂, as well as limits carrier conduction to spin-degenerate conduction bands instead of the more interesting, spin-polarized valence bands. Traditionally, extrinsic p-type doping in TMDs has been approached with surface adsorption or intercalation of electron-accepting molecules. However, practically stable doping requires substitution of host atoms with dopants where the doping is secured by covalent bonding. In this work, we demonstrate stable p-type conduction in MoS₂ by substitutional niobium (Nb) doping, leading to a degenerate hole density of ~3 × 10¹⁹ cm⁻³. Structural and X-ray techniques reveal that the Nb atoms are indeed substitutionally incorporated into MoS₂ by replacing the Mo cations in the host lattice. van der Waals p–n homojunctions based on vertically stacked MoS₂ layers are fabricated, which enable gate-tunable current rectification. A wide range of microelectronic, optoelectronic, and spintronic devices can be envisioned from the demonstrated substitutional bipolar doping of MoS₂. From the miscibility of dopants with the host, it is also expected that the synthesis technique demonstrated here can be generally extended to other TMDs for doping against their native unipolar propensity.

  14. CHARACTERISTIC LENGTH OF ENERGY-CONTAINING STRUCTURES AT THE BASE OF A CORONAL HOLE

    SciTech Connect (OSTI)

    Abramenko, V. I.; Yurchyshyn, V. B.; Goode, P. R.; Ahn, K.; Cao, W.; Zank, G. P.; Dosch, A.

    2013-08-20

    An essential parameter for models of coronal heating and fast solar wind acceleration that rely on the dissipation of MHD turbulence is the characteristic energy-containing length {lambda} of the squared velocity and magnetic field fluctuations (u{sup 2} and b{sup 2}) transverse to the mean magnetic field inside a coronal hole (CH) at the base of the corona. The characteristic length scale directly defines the heating rate. We use a time series analysis of solar granulation and magnetic field measurements inside two CHs obtained with the New Solar Telescope at Big Bear Solar Observatory. A data set for transverse magnetic fields obtained with the Solar Optical Telescope/Spectro-Polarimeter on board the Hinode spacecraft was utilized to analyze the squared transverse magnetic field fluctuations b{sub t}{sup 2}. Local correlation tracking was applied to derive the squared transverse velocity fluctuations u {sup 2}. We find that for u {sup 2} structures, the Batchelor integral scale {lambda} varies in a range of 1800-2100 km, whereas the correlation length sigmav and the e-folding length L vary between 660 and 1460 km. Structures for b{sub t}{sup 2} yield {lambda} Almost-Equal-To 1600 km, sigmav Almost-Equal-To 640 km, and L Almost-Equal-To 620 km. An averaged (over {lambda}, sigmav, and L) value of the characteristic length of u {sup 2} fluctuations is 1260 {+-} 500 km, and that of b{sub t}{sup 2} is 950 {+-} 560 km. The characteristic length scale in the photosphere is approximately 1.5-50 times smaller than that adopted in previous models (3-30 Multiplication-Sign 10{sup 3} km). Our results provide a critical input parameter for current models of coronal heating and should yield an improved understanding of fast solar wind acceleration.

  15. Characterization of the liquid sodium spray generated by a pipework hole

    SciTech Connect (OSTI)

    Torsello, G.; Parozzi, F.; Nericcio, L.; Araneo, L.; Cozzi, F.; Carcassi, M.; Mattei, N.

    2012-07-01

    Due to its advantageous thermodynamic characteristics at high temperature (550 deg. C), liquid sodium is the main candidate to be the cooling fluid for Generation TV nuclear reactors SFR (Sodium-cooled Fast Reactors). Now, sodium reacts very violently, both with the water and the oxygen of the air. Only few data were known about the liquid sodium behaviour when spread in the environment through micro defects. These are often present in a cooling circuit in welded or sealed joints and more rarely in the pipes. Micro defects, on the other hand, can be also generated in a cooling circuit because of the vibrations always present in a circuit into which a fluid runs. A new set-up, named LISOF, was built for testing high temperature liquid sodium when passing through micro defects and generating sprays or jets. Sprays and jets were generated by means of nozzles embedding sub milli-metric holes the diameter of which was: 0.2 mm, 0.4 mm, 0.5 mm. Tests were performed by pressurizing liquid sodium (550 deg. C) at: 3, 6 and 9 barg. Normal and high speed cinematography were used for the direct observation of the liquid sodium sprays while Phase Doppler Interferometry was used for the measurement of the droplets characteristics and velocity. Tests concerning the behaviour of the high temperature liquid sodium firing in air or in contact with the cement cover applied to a scaled down core catcher simulacrum were also performed. The paper presents the built set-up and the collected results. (authors)

  16. ENERGY-DEPENDENT POWER SPECTRAL STATES AND ORIGIN OF APERIODIC VARIABILITY IN BLACK HOLE BINARIES

    SciTech Connect (OSTI)

    Yu Wenfei; Zhang Wenda, E-mail: wenfei@shao.ac.cn [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China)

    2013-06-20

    We found that the black hole candidate MAXI J1659-152 showed distinct power spectra, i.e., power-law noise (PLN) versus band-limited noise (BLN) plus quasi-periodic oscillations (QPOs) below and above about 2 keV, respectively, in observations with Swift and the Rossi X-ray Timing Explorer during the 2010 outburst, indicating a high energy cutoff of the PLN and a low energy cutoff of the BLN and QPOs around 2 keV. The emergence of the PLN and the fading of the BLN and QPOs initially took place below 2 keV when the source entered the hard intermediate state and settled in the soft state three weeks later. The evolution was accompanied by the emergence of the disk spectral component and decreases in the amplitudes of variability in the soft and hard X-ray bands. Our results indicate that the PLN is associated with an optically thick disk in both hard and intermediate states, and the power spectral state is independent of the X-ray energy spectral state in a broadband view. We suggest that in the hard or intermediate state, the BLN and QPOs emerge from the innermost hot flow subjected to Comptonization, while the PLN originates from the optically thick disk farther out. The energy cutoffs of the PLN and the BLN or QPOs then follow the temperature of the seed photons from the inner edge of the optically thick disk, while the high frequency cutoff of the PLN follows the orbital frequency of the inner edge of the optically thick disk as well.

  17. The black hole binary V4641 Sagitarii: Activity in quiescence and improved mass determinations

    SciTech Connect (OSTI)

    MacDonald, Rachel K. D.; Bailyn, Charles D.; Buxton, Michelle; Cantrell, Andrew G.; Chatterjee, Ritaban; Kennedy-Shaffer, Ross; Orosz, Jerome A.; Markwardt, Craig B.; Swank, Jean H.

    2014-03-20

    We examine ?10 yr of photometric data and find that the black hole X-ray binary V4641 Sgr has two optical states, passive and active, during X-ray quiescence. The passive state is dominated by ellipsoidal variations and is stable in the shape and variability of the light curve. The active state is brighter and more variable. Emission during the active state varies over the course of the orbital period and is redder than the companion star. These optical/infrared states last for weeks or months. V4641 Sgr spends approximately 85% of X-ray quiescence in the passive state and 15% in the active. We analyze passive colors and spectroscopy of V4641 Sgr and show that they are consistent with a reddened B9III star (with E(B V) = 0.37 0.19) with little or no contribution from the accretion disk. We use X-ray observations with an updated ephemeris to place an upper limit on the duration of an X-ray eclipse of <8.3 in phase (?1.6 hr). High-resolution spectroscopy yields a greatly improved measurement of the rotational velocity of the companion star of V {sub rot}sin i = 100.9 0.8 km s{sup 1}. We fit ellipsoidal models to the passive state data and find an inclination angle of i = 72.3 4.1, a mass ratio of Q = 2.2 0.2, and component masses for the system of M {sub BH} = 6.4 0.6 M {sub ?} and M {sub 2} = 2.9 0.4 M {sub ?}. Using these values we calculate an updated distance to V4641 Sgr of 6.2 0.7 kpc.

  18. A NEW DYNAMICAL MODEL FOR THE BLACK HOLE BINARY LMC X-1

    SciTech Connect (OSTI)

    Orosz, Jerome A.; Steeghs, Danny; McClintock, Jeffrey E. E-mail: D.T.H.Steeghs@warwick.ac.uk

    2009-05-20

    We present a dynamical model of the high mass X-ray binary LMC X-1 based on high-resolution optical spectroscopy and extensive optical and near-infrared photometry. From our new optical data we find an orbital period of P = 3.90917 {+-} 0.00005 days. We present a refined analysis of the All Sky Monitor data from RXTE and find an X-ray period of P = 3.9094 {+-} 0.0008 days, which is consistent with the optical period. A simple model of Thomson scattering in the stellar wind can account for the modulation seen in the X-ray light curves. The V - K color of the star (1.17 {+-} 0.05) implies A{sub V} = 2.28 {+-} 0.06, which is much larger than previously assumed. For the secondary star, we measure a radius of R {sub 2} = 17.0 {+-} 0.8 R {sub sun} and a projected rotational velocity of V {sub rot}sin i = 129.9 {+-} 2.2 km s{sup -1}. Using these measured properties to constrain the dynamical model, we find an inclination of i = 36.{sup 0}38 {+-} 1.{sup 0}92, a secondary star mass of M {sub 2} = 31.79 {+-} 3.48 M {sub sun}, and a black hole mass of 10.91 {+-} 1.41 M {sub sun}. The present location of the secondary star in a temperature-luminosity diagram is consistent with that of a star with an initial mass of 35 M {sub sun} that is 5 Myr past the zero-age main sequence. The star nearly fills its Roche lobe ({approx}90% or more), and owing to the rapid change in radius with time in its present evolutionary state, it will encounter its Roche lobe and begin rapid and possibly unstable mass transfer on a timescale of a few hundred thousand years.

  19. PLASMA JETS AND ERUPTIONS IN SOLAR CORONAL HOLES: A THREE-DIMENSIONAL FLUX EMERGENCE EXPERIMENT

    SciTech Connect (OSTI)

    Moreno-Insertis, F.

    2013-07-01

    A three-dimensional (3D) numerical experiment of the launching of a hot and fast coronal jet followed by several violent eruptions is analyzed in detail. These events are initiated through the emergence of a magnetic flux rope from the solar interior into a coronal hole. We explore the evolution of the emerging magnetically dominated plasma dome surmounted by a current sheet and the ensuing pattern of reconnection. A hot and fast coronal jet with inverted-Y shape is produced that shows properties comparable to those frequently observed with EUV and X-ray detectors. We analyze its 3D shape, its inhomogeneous internal structure, and its rise and decay phases, lasting for some 15-20 minutes each. Particular attention is devoted to the field line connectivities and the reconnection pattern. We also study the cool and high-density volume that appears to encircle the emerged dome. The decay of the jet is followed by a violent phase with a total of five eruptions. The first of them seems to follow the general pattern of tether-cutting reconnection in a sheared arcade, although modified by the field topology created by the preceding reconnection evolution. The two following eruptions take place near and above the strong-field concentrations at the surface. They show a twisted, {Omega}-loop-like rope expanding in height, with twist being turned into writhe, thus hinting at a kink instability (perhaps combined with a torus instability) as the cause of the eruption. The succession of a main jet ejection and a number of violent eruptions that resemble mini-CMEs and their physical properties suggest that this experiment may provide a model for the blowout jets recently proposed in the literature.

  20. Development of Radar Navigation and Radio Data Transmission for Microhole Coiled Tubing Bottom Hole Assemblies

    SciTech Connect (OSTI)

    Larry G. Stolarczyk; Gerald L. Stolarczyk; Larry Icerman; John Howard; Hooman Tehrani

    2007-03-25

    This Final Technical Report summarizes the research and development (R&D) work performed by Stolar Research Corporation (Stolar) under U.S. Department of Energy (DOE) Contract Number DE-FC26-04NT15477. This work involved the development of radar navigation and radio data transmission systems for integration with microhole coiled tubing bottom hole assemblies. Under this contract, Stolar designed, fabricated, and laboratory and field tested two advanced technologies of importance to the future growth of the U.S. oil and gas industry: (1) real-time measurement-while-drilling (MWD) for guidance and navigation of coiled tubing drilling in hydrocarbon reservoirs and (2) two-way inductive radio data transmission on coiled tubing for real-time, subsurface-to-surface data transmission. The operating specifications for these technologies are compatible with 3.5-inch boreholes drilled to a true vertical depth (TVD) of 5,000 feet, which is typical of coiled tubing drilling applications. These two technologies (i.e., the Stolar Data Transmission System and Drill String Radar) were developed into pre-commercial prototypes and tested successfully in simulated coiled tubing drilling conditions. Integration of these two technologies provides a real-time geosteering capability with extremely quick response times. Stolar is conducting additional work required to transition the Drill String Radar into a true commercial product. The results of this advanced development work should be an important step in the expanded commercialization of advanced coiled tubing microhole drilling equipment for use in U.S. hydrocarbon reservoirs.

  1. Random matrix theory for mixed regular-chaotic dynamics in the super-extensive regime

    SciTech Connect (OSTI)

    El-Hady, A. Abd; Abul-Magd, A. Y.

    2011-10-27

    We apply Tsallis's q-indexed nonextensive entropy to formulate a random matrix theory (RMT), which may be suitable for systems with mixed regular-chaotic dynamics. We consider the super-extensive regime of q<1. We obtain analytical expressions for the level-spacing distributions, which are strictly valid for 2 X2 random-matrix ensembles, as usually done in the standard RMT. We compare the results with spacing distributions, numerically calculated for random matrix ensembles describing a harmonic oscillator perturbed by Gaussian orthogonal and unitary ensembles.

  2. Robust random number generation using steady-state emission of gain-switched laser diodes

    SciTech Connect (OSTI)

    Yuan, Z. L. Lucamarini, M.; Dynes, J. F.; Frhlich, B.; Plews, A.; Shields, A. J.

    2014-06-30

    We demonstrate robust, high-speed random number generation using interference of the steady-state emission of guaranteed random phases, obtained through gain-switching a semiconductor laser diode. Steady-state emission tolerates large temporal pulse misalignments and therefore significantly improves the interference quality. Using an 8-bit digitizer followed by a finite-impulse-response unbiasing algorithm, we achieve random number generation rates of 8 and 20?Gb/s, for laser repetition rates of 1 and 2.5?GHz, respectively, with a 20% tolerance in the interferometer differential delay. We also report a generation rate of 80?Gb/s using partially phase-correlated short pulses. In relation to the field of quantum key distribution, our results confirm the gain-switched laser diode as a suitable light source, capable of providing phase-randomized coherent pulses at a clock rate of up to 2.5?GHz.

  3. Search for Stripes in Antiferromagnetic Lightly Hole-Doped YBa2Cu3O6: An Electron Spin Resonance and Infrared Tranmission Study

    SciTech Connect (OSTI)

    Janossy,A.; Nagy, K.; Feher, T.; Mihaly, L.; Erb, A.

    2007-01-01

    We present a series of electron spin resonance (ESR) and infrared transmission experiments in antiferromagnetic (AF), lightly hole-doped YBa{sub 2}Cu{sub 3}O{sub 6} in search for the effect of a spatially inhomogeneous ground state on the magnetic and electric properties. Crystal compositions were Ca{sub x}Gd{sub y}Y{sub 1-x-y}Ba{sub 2}Cu{sub 3}O{sub 6} with x=0 , 0.008, 0.02, and 0.03 and y{approx}0.01 . Gd{sup 3+} ESR satellites from sites with first-neighbor Ca atoms show that holes are not preferentially localized at low temperatures in the vicinity of Ca dopants. We mapped by multifrequency Gd{sup 3+} ESR the AF domain structure as a function of hole concentration, temperature, and magnetic fields up to 8T . We attribute the hole-doping-induced rotation of the magnetic easy axis from collateral to diagonal (with respect to the tetragonal CuO{sub 2} lattice) to the pinning of the AF magnetization to a static modulation or a phase-separated network of the hole density. The dominantly fourfold symmetry of pinning suggests that the hole density network has this symmetry also and is not an array of stripes. At higher temperatures the pinning to the diagonal direction becomes weak and the possibility of domain wall fluctuations is discussed. There is no magnetic field dependence and no in-plane anisotropy of the infrared transmission polarized in the CuO{sub 2} planes in an x=0.02 crystal placed in magnetic fields up to 12T . Thus, the network of holes is rigid and is not affected by magnetic fields that are, however, strong enough to rotate the AF magnetization into a single domain.

  4. BPA-2013-01495-FOIA Request

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    on this form. Name Chuck Johnson Email chuck@oregonpsr.org Organization Physicians for Social Responsibility Mailing Address 812 SW Washington Street, Suite 1050 City Portland...

  5. BPA-2014-00207-FOIA Request

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    on this form. Name Chuck Johnson Email chuck@oregonpsr.org Orga nizati Physicians for Social Responsibility on Mailin Addre 812 SW Washington Street, Suite 1050 Ss City...

  6. BPA-2013-01739-FOIA Request

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    on this form. Name Chuck Johnson Email chuck@oregonpsr.org Orga nizati Physicians for Social Responsibility on Mailin Addre 812 SW Washington Street, Suite 1050 ss City...

  7. BPA-2014-00434-FOIA Request

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    on this form. Name Chuck Johnson Email chuck@oregonpsr.org Orga nizati Physicians for Social Responsibility on Mailn Addre 812 SW Washington Street, Suite 1050 ss City...

  8. Random-matrix approach to the statistical compound nuclear reaction at low

    Office of Scientific and Technical Information (OSTI)

    energies using the Monte-Carlo technique (Conference) | SciTech Connect Conference: Random-matrix approach to the statistical compound nuclear reaction at low energies using the Monte-Carlo technique Citation Details In-Document Search Title: Random-matrix approach to the statistical compound nuclear reaction at low energies using the Monte-Carlo technique Authors: Kawano, Toshihiko [1] + Show Author Affiliations Los Alamos National Laboratory Publication Date: 2015-11-10 OSTI Identifier:

  9. Fundamental studies of energy-and hole/electron- transfer in hydroporphyrin architectures

    SciTech Connect (OSTI)

    Bocian, David F.

    2014-08-20

    The long-term objective of the Bocian/Holten/Lindsey research program is to design, synthesize, and characterize tetrapyrrole-based molecular architectures that absorb sunlight, funnel energy, and separate charge with high efficiency and in a manner compatible with current and future solar-energy conversion schemes. The synthetic tetrapyrroles include porphyrins and hydroporphyrins; the latter classes of molecules encompass analogues of the naturally occurring chlorophylls and bacteriochlorophylls (e.g., chlorins, bacteriochlorins, and their derivatives). The attainment of the goals of the research program requires the close interplay of molecular design and synthesis (Lindsey group), static and time-resolved optical spectroscopic measurements (Holten group), and electrochemical, electron paramagnetic resonance, and resonance Raman studies, as well as density functional theory calculations (Bocian Group). The proposed research encompasses four interrelated themes: (1) Determination of the rates of ground-state hole/electron transfer between (hydro)porphyrins in multipigment arrays as a function of array size, distance between components, linker type, site of linker connection, and frontier molecular orbital composition. (2) Examination of excited-state energy transfer among hydroporphyrins in multipigment arrrays, including both pairwise and non-adjacent transfer, with a chief aim to identify the relative contributions of through-space (Förster) and through-bond (Dexter) mechanisms of energy transfer, including the roles of site of linker connection and frontier molecular orbital composition. (3) Elucidation of the role of substituents in tuning the spectral and electronic properties of bacteriochlorins, with a primary aim of learning how to shift the long-wavelength absorption band deeper into the near-infrared region. (4) Continued development of the software package PhotochemCAD for spectral manipulations and calculations through the compilation of a database of spectra for naturally occurring and synthetic hydroporphyrins. The availability of such data should augment efforts in the design of light-harvesting systems where spectral coverage in the red and near-infrared regions is desired. Collectively, the proposed studies will provide fundamental insights into molecular properties, interactions, and processes relevant to the design of molecular architectures for solar-energy conversion. The accomplishment of these goals is only possible through a highly synergistic program that encompasses molecular design, synthesis, and characterization.

  10. DUAL SUPERMASSIVE BLACK HOLE CANDIDATES IN THE AGN AND GALAXY EVOLUTION SURVEY

    SciTech Connect (OSTI)

    Comerford, Julia M.; Schluns, Kyle; Greene, Jenny E.; Cool, Richard J.

    2013-11-01

    Dual supermassive black holes (SMBHs) with kiloparsec-scale separations in merger-remnant galaxies are informative tracers of galaxy evolution, but the avenue for identifying them in large numbers for such studies is not yet clear. One promising approach is to target spectroscopic signatures of systems where both SMBHs are fueled as dual active galactic nuclei (AGNs), or where one SMBH is fueled as an offset AGN. Dual AGNs may produce double-peaked narrow AGN emission lines, while offset AGNs may produce single-peaked narrow AGN emission lines with line-of-sight velocity offsets relative to the host galaxy. We search for such dual and offset systems among 173 Type 2 AGNs at z < 0.37 in the AGN and Galaxy Evolution Survey (AGES), and we find two double-peaked AGNs and five offset AGN candidates. When we compare these results to a similar search of the DEEP2 Galaxy Redshift Survey and match the two samples in color, absolute magnitude, and minimum velocity offset, we find that the fraction of AGNs that are dual SMBH candidates increases from z = 0.25 to z = 0.7 by a factor of ?6 (from 2/70 to 16/91, or 2.9{sup +3.6}{sub -1.9}% to 18{sup +5}{sub -5}%). This may be associated with the rise in the galaxy merger fraction over the same cosmic time. As further evidence for a link with galaxy mergers, the AGES offset and dual AGN candidates are tentatively ?3 times more likely than the overall AGN population to reside in a host galaxy that has a companion galaxy (from 16/173 to 2/7, or 9{sup +3}{sub -2}% to 29{sub -19}{sup +26}%). Follow-up observations of the seven offset and dual AGN candidates in AGES will definitively distinguish velocity offsets produced by dual SMBHs from those produced by narrow-line region kinematics, and will help sharpen our observational approach to detecting dual SMBHs.

  11. Star formation and black hole growth at z ? 4.8

    SciTech Connect (OSTI)

    Netzer, Hagai; Mor, Rivay; Trakhtenbrot, Benny; Shemmer, Ohad; Lira, Paulina

    2014-08-10

    We report Herschel/SPIRE, Spitzer and Wide-field Infrared Survey Explorer observations of 44 z ? 4.8 optically selected active galactic nuclei (AGNs). This flux-limited sample contains the highest mass black holes (BHs) at this redshift. Ten of the objects were detected by Herschel and five show emission that is not clearly associated with the AGNs. The star formation (SF) luminosity (L{sub SF}) obtained by fitting the spectral energy distribution (SED) with standard SF templates, taking into account AGN contribution, is in the range 10{sup 46.62}-10{sup 47.21} erg s{sup 1} corresponding to SF rates of 1090-4240 M{sub ?} yr{sup 1}. Fitting with very luminous submillimeter galaxy SEDs gives SF rates that are smaller by 0.05 dex when using all bands and 0.1 dex when ignoring the 250 ?m band. A 40 K graybody fits to only the 500 ?m fluxes reduce L{sub SF} by about a factor of two. A stacking analysis of 29 undetected sources gives significant signals in all three bands. A SF template fit indicates L{sub SF} = 10{sup 46.19-46.23} erg s{sup 1} depending on the assumed AGN contribution. A 40 K fit to the stacked 500 ?m flux gives L{sub SF} = 10{sup 45.95} erg s{sup 1}. The mean BH mass (M{sub BH}) and AGN luminosity (L{sub AGN}) of the detected sources are significantly higher than those of the undetected ones. The spectral differences are seen all the way from UV to far infrared wavelengths. The mean optical-UV spectra are similar to those predicted for thin accretion disks around BHs with similar masses and accretion rates. We suggest two alternative explanations to the correlation of L{sub SF}, L{sub AGN} and M{sub BH}, one involving no AGN feedback and the second involving moderate feedback that affects, but does not totally quench, SF in three-quarters of the sources. We compare our L{sub SF} and L{sub AGN} to lower redshift samples and show a new correlation between L{sub SF} and M{sub BH}. We also examine several rather speculative ideas about the host galaxy properties including the possibility that the detected sources are above the SF mass sequence (MS) at z ? 4.8, perhaps in mergers, and most of the undetected sources are on the MS.

  12. General Relativistic Magnetohydrodynamic Simulations of Magnetically Choked Accretion Flows around Black Holes

    SciTech Connect (OSTI)

    McKinney, Jonathan C.; Tchekhovskoy, Alexander; Blandford, Roger D.

    2012-04-26

    Black hole (BH) accretion flows and jets are qualitatively affected by the presence of ordered magnetic fields. We study fully three-dimensional global general relativistic magnetohydrodynamic (MHD) simulations of radially extended and thick (height H to cylindrical radius R ratio of |H/R| {approx} 0.2-1) accretion flows around BHs with various dimensionless spins (a/M, with BH mass M) and with initially toroidally-dominated ({phi}-directed) and poloidally-dominated (R-z directed) magnetic fields. Firstly, for toroidal field models and BHs with high enough |a/M|, coherent large-scale (i.e. >> H) dipolar poloidal magnetic flux patches emerge, thread the BH, and generate transient relativistic jets. Secondly, for poloidal field models, poloidal magnetic flux readily accretes through the disk from large radii and builds-up to a natural saturation point near the BH. While models with |H/R| {approx} 1 and |a/M| {le} 0.5 do not launch jets due to quenching by mass infall, for sufficiently high |a/M| or low |H/R| the polar magnetic field compresses the inflow into a geometrically thin highly non-axisymmetric 'magnetically choked accretion flow' (MCAF) within which the standard linear magneto-rotational instability is suppressed. The condition of a highly-magnetized state over most of the horizon is optimal for the Blandford-Znajek mechanism that generates persistent relativistic jets with and 100% efficiency for |a/M| {approx}> 0.9. A magnetic Rayleigh-Taylor and Kelvin-Helmholtz unstable magnetospheric interface forms between the compressed inflow and bulging jet magnetosphere, which drives a new jet-disk oscillation (JDO) type of quasi-periodic oscillation (QPO) mechanism. The high-frequency QPO has spherical harmonic |m| = 1 mode period of {tau} {approx} 70GM/c{sup 3} for a/M {approx} 0.9 with coherence quality factors Q {approx}> 10. Overall, our models are qualitatively distinct from most prior MHD simulations (typically, |H/R| << 1 and poloidal flux is limited by initial conditions), so they should prove useful for testing accretion-jet theories and measuring a/M in systems such as SgrA* and M87.

  13. ULTRAVIOLET EMISSION-LINE CORRELATIONS IN HST/COS SPECTRA OF ACTIVE GALACTIC NUCLEI: SINGLE-EPOCH BLACK HOLE MASSES

    SciTech Connect (OSTI)

    Tilton, Evan M.; Shull, J. Michael, E-mail: evan.tilton@colorado.edu, E-mail: michael.shull@colorado.edu [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309 (United States)

    2013-09-01

    Effective methods of measuring supermassive black hole masses in active galactic nuclei (AGNs) are of critical importance to studies of galaxy evolution. While there has been much success in obtaining masses through reverberation mapping, the extensive observing time required by this method has limited the practicality of applying it to large samples at a variety of redshifts. This limitation highlights the need to estimate these masses using single-epoch spectroscopy of ultraviolet (UV) emission lines. We use UV spectra of 44 AGNs from HST/COS, the International Ultraviolet Explorer, and the Far Ultraviolet Spectroscopic Explorer of the C IV {lambda}1549, O VI {lambda}1035, O III] {lambda}1664, He II {lambda}1640, C II {lambda}1335, and Mg II {lambda}2800 emission lines and explore their potential as tracers of the broad-line region and supermassive black hole mass. The higher signal-to-noise ratio and better spectral resolution of the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST) resolve AGN intrinsic absorption and produce more accurate line widths. From these, we test the viability of mass-scaling relationships based on line widths and luminosities and carry out a principal component analysis based on line luminosities, widths, skewness, and kurtosis. At L{sub 1450} {<=} 10{sup 45} erg s{sup -1}, the UV line luminosities correlate well with H{beta}, as does the 1450 A continuum luminosity. We find that C IV, O VI, and Mg II can be used as reasonably accurate estimators of AGN black hole masses, while He II and C II are uncorrelated.

  14. MoO3 as combined hole injection layer and tapered spacer in combinatorial multicolor microcavity organic light emitting diodes

    SciTech Connect (OSTI)

    Liu, R.; Xu, Chun; Biswas, Rana; Shinar, Joseph; Shinar, Ruth

    2011-09-01

    Multicolor microcavity ({mu}C) organic light-emitting diode (OLED) arrays were fabricated simply by controlling the hole injection and spacer MoO{sub 3} layer thickness. The normal emission was tunable from {approx}490 to 640 nm and can be further expanded. A compact, integrated spectrometer with two-dimensional combinatorial arrays of {mu}C OLEDs was realized. The MoO{sub 3} yields more efficient and stable devices, revealing a new breakdown mechanism. The pixel current density reaches {approx}4 A/cm{sup 2} and a maximal normal brightness {approx}140 000 Cd/m{sup 2}, which improves photoluminescence-based sensing and absorption measurements.

  15. THE QUASAR SDSS J153636.22+044127.0: A DOUBLE-PEAKED EMITTER IN A CANDIDATE BINARY BLACK HOLE SYSTEM

    SciTech Connect (OSTI)

    Tang Sumin; Grindlay, Jonathan

    2009-10-20

    Double-peaked emission lines are believed to be originated from accretion disks around supermassive black holes (SMBHs), and about 3% of z < 0.33 active galactic nuclei (AGNs) are found to be double-peaked emitters. The quasar SDSS J153636.22+044127.0 has recently been identified with peculiar broad-line emission systems exhibiting multiple redshifts. We decompose the Halpha and Hbeta profiles into a circular Keplerian disk-line component and other Gaussian components. We propose that the system is both a double-peaked emitter and a binary SMBH system, where the extra flux in the blue peaks of the broad lines comes from the region around the secondary black hole. We suggest that such black hole binary systems might also exist in many known double-peaked emitters, where the tidal torques from the secondary black hole clear the outer region of the disk around the primary black hole, similar to the gap in a protostellar disk due to the process of planetary migration, and might also stimulate the formation of a vertical extended source in the inner region around the primary which illuminates the disk. However, most secondary SMBHs in such systems might be too small to maintain a detectable broad-line region (BLR), so that the disk line from the primary dominates.

  16. Low power zinc-oxide based charge trapping memory with embedded silicon nanoparticles via poole-frenkel hole emission

    SciTech Connect (OSTI)

    El-Atab, Nazek; Nayfeh, Ammar; Ozcan, Ayse; Alkis, Sabri; Okyay, Ali K.; Department of Electrical and Electronics Engineering, Bilkent University, 06800 Ankara

    2014-01-06

    A low power zinc-oxide (ZnO) charge trapping memory with embedded silicon (Si) nanoparticles is demonstrated. The charge trapping layer is formed by spin coating 2?nm silicon nanoparticles between Atomic Layer Deposited ZnO steps. The threshold voltage shift (?V{sub t}) vs. programming voltage is studied with and without the silicon nanoparticles. Applying ?1?V for 5?s at the gate of the memory with nanoparticles results in a ?V{sub t} of 3.4?V, and the memory window can be up to 8?V with an excellent retention characteristic (>10 yr). Without nanoparticles, at ?1?V programming voltage, the ?V{sub t} is negligible. In order to get ?V{sub t} of 3.4?V without nanoparticles, programming voltage in excess of 10?V is required. The negative voltage on the gate programs the memory indicating that holes are being trapped in the charge trapping layer. In addition, at 1?V the electric field across the 3.6?nm tunnel oxide is calculated to be 0.36 MV/cm, which is too small for significant tunneling. Moreover, the ?V{sub t} vs. electric field across the tunnel oxide shows square root dependence at low fields (E??2.7 MV/cm). This indicates that Poole-Frenkel Effect is the main mechanism for holes emission at low fields and Phonon Assisted Tunneling at higher fields.

  17. The inversion layer of electric fields and electron phase-space-hole structure during two-dimensional collisionless magnetic reconnection

    SciTech Connect (OSTI)

    Chen Lijen; Lefebvre, Bertrand; Torbert, Roy B.; Daughton, William S.

    2011-01-15

    Based on two-dimensional fully kinetic simulations that resolve the electron diffusion layer in undriven collisionless magnetic reconnection with zero guide field, this paper reports the existence and evolution of an inversion layer of bipolar electric fields, its corresponding phase-space structure (an electron-hole layer), and the implication to collisionless dissipation. The inversion electric field layer is embedded in the layer of bipolar Hall electric field and extends throughout the entire length of the electron diffusion layer. The electron phase-space hole structure spontaneously arises during the explosive growth phase when there exist significant inflows into the reconnection layer, and electrons perform meandering orbits across the layer while being cyclotron-turned toward the outflow directions. The cyclotron turning of meandering electrons by the magnetic field normal to the reconnection layer is shown to be a primary factor limiting the current density in the region where the reconnection electric field is balanced by the gradient (along the current sheet normal) of the off-diagonal electron pressure-tensor.

  18. TIDAL DISRUPTIONS OF WHITE DWARFS FROM ULTRA-CLOSE ENCOUNTERS WITH INTERMEDIATE-MASS SPINNING BLACK HOLES

    SciTech Connect (OSTI)

    Haas, Roland; Bode, Tanja; Laguna, Pablo; Shcherbakov, Roman V.

    2012-04-20

    We present numerical relativity results of tidal disruptions of white dwarfs from ultra-close encounters with a spinning, intermediate-mass black hole (IMBH). These encounters require a full general relativistic treatment of gravity. We show that the disruption process and prompt accretion of the debris strongly depend on the magnitude and orientation of the black hole (BH) spin. However, the late-time accretion onto the BH follows the same decay, M-dot {proportional_to} t{sup -5/3}, estimated from Newtonian gravity disruption studies. We compute the spectrum of the disk formed from the fallback material using a slim disk model. The disk spectrum peaks in the soft X-rays and sustains Eddington luminosity for 1-3 yr after the disruption. For arbitrary BH spin orientations, the disrupted material is scattered away from the orbital plane by relativistic frame dragging, which often leads to obscuration of the inner fallback disk by the outflowing debris. The disruption events also yield bursts of gravitational radiation with characteristic frequencies of {approx}3.2 Hz and strain amplitudes of {approx}10{sup -18} for galactic IMBHs. The optimistic rate of considered ultra-close disruptions is consistent with no sources found in the ROSAT all-sky survey. Future missions like Wide-Field X-ray Telescope could observe dozens of events.

  19. Supermassive black holes with high accretion rates in active galactic nuclei. II. The most luminous standard candles in the universe

    SciTech Connect (OSTI)

    Wang, Jian-Min; Du, Pu; Hu, Chen; Qiu, Jie; Li, Yan-Rong [Key Laboratory for Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, 19B Yuquan Road, Beijing 100049 (China); Netzer, Hagai; Kaspi, Shai [Wise Observatory, School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv 69978 (Israel); Bai, Jin-Ming; Wang, Fang [Yunnan Observatory, Chinese Academy of Sciences, Kunming 650011, Yunnan (China); Lu, Kai-Xing [Astronomy Department, Beijing Normal University, Beijing 100875 (China); Collaboration: SEAMBH collaboration

    2014-10-01

    This is the second in a series of papers reporting on a large reverberation mapping (RM) campaign to measure black hole (BH) mass in high accretion rate active galactic nuclei (AGNs). The goal is to identify super-Eddington accreting massive black holes (SEAMBHs) and to use their unique properties to construct a new method for measuring cosmological distances. Based on theoretical models, the saturated bolometric luminosity of such sources is proportional to the BH mass, which can be used to obtain their distance. Here we report on five new RM measurements and show that in four of the cases, we can measure the BH mass and three of these sources are SEAMBHs. Together with the three sources from our earlier work, we now have six new sources of this type. We use a novel method based on a minimal radiation efficiency to identify nine additional SEAMBHs from earlier RM-based mass measurements. We use a Bayesian analysis to determine the parameters of the new distance expression and the method uncertainties from the observed properties of the objects in the sample. The ratio of the newly measured distances to the standard cosmological ones has a mean scatter of 0.14 dex, indicating that SEAMBHs can be use as cosmological distance probes. With their high luminosity, long period of activity, and large numbers at high redshifts, SEAMBHs have a potential to extend the cosmic distance ladder beyond the range now explored by Type Ia supernovae.

  20. Disruption of a red giant star by a supermassive black hole and the case of PS1-10jh

    SciTech Connect (OSTI)

    Bogdanovi?, Tamara; Cheng, Roseanne M.; Amaro-Seoane, Pau E-mail: rcheng@gatech.edu

    2014-06-20

    The development of a new generation of theoretical models for tidal disruptions is timely, as increasingly diverse events are being captured in surveys of the transient sky. Recently, Gezari et al. reported a discovery of a new class of tidal disruption events: the disruption of a helium-rich stellar core, thought to be a remnant of a red giant (RG) star. Motivated by this discovery and in anticipation of others, we consider tidal interaction of an RG star with a supermassive black hole (SMBH) which leads to the stripping of the stellar envelope and subsequent inspiral of the compact core toward the black hole. Once the stellar envelope is removed the inspiral of the core is driven by tidal heating as well as the emission of gravitational radiation until the core either falls into the SMBH or is tidally disrupted. In the case of the tidal disruption candidate PS1-10jh, we find that there is a set of orbital solutions at high eccentricities in which the tidally stripped hydrogen envelope is accreted by the SMBH before the helium core is disrupted. This places the RG core in a portion of parameter space where strong tidal heating can lift the degeneracy of the compact remnant and disrupt it before it reaches the tidal radius. We consider how this sequence of events explains the puzzling absence of the hydrogen emission lines from the spectrum of PS1-10jh and gives rise to its other observational features.

  1. HYPERACCRETING BLACK HOLE AS GAMMA-RAY BURST CENTRAL ENGINE. I. BARYON LOADING IN GAMMA-RAY BURST JETS

    SciTech Connect (OSTI)

    Lei Weihua; Zhang Bing; Liang Enwei E-mail: zhang@physics.unlv.edu

    2013-03-10

    A hyperaccreting stellar-mass black hole has been long speculated as the best candidate for the central engine of gamma-ray bursts (GRBs). Recent rich observations of GRBs by space missions such as Swift and Fermi pose new constraints on GRB central engine models. In this paper, we study the baryon-loading processes of a GRB jet launched from a black hole central engine. We consider a relativistic jet powered by {nu} {nu}-bar -annihilation or by the Blandford-Znajek (BZ) mechanism. We consider baryon loading from a neutrino-driven wind launched from a neutrino-cooling-dominated accretion flow. For a magnetically dominated BZ jet, we consider neutron drifting from the magnetic wall surrounding the jet and subsequent positron capture and proton-neutron inelastic collisions. The minimum baryon loads in both types of jet are calculated. We find that in both cases a more luminous jet tends to be more baryon poor. A neutrino-driven ''fireball'' is typically ''dirtier'' than a magnetically dominated jet, while a magnetically dominated jet can be much cleaner. Both models have the right scaling to interpret the empirical {Gamma}-L{sub iso} relation discovered recently. Since some neutrino-driven jets have too much baryon loading as compared with the data, we suggest that at least a good fraction of GRBs should have a magnetically dominated central engine.

  2. p-doping-free InGaN/GaN light-emitting diode driven by three-dimensional hole gas

    SciTech Connect (OSTI)

    Zhang, Zi-Hui; Tiam Tan, Swee; Kyaw, Zabu; Liu, Wei; Ji, Yun; Ju, Zhengang; Zhang, Xueliang [LUMINOUS Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore) [LUMINOUS Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore); LUMINOUS Centre of Excellence for Semiconductor Lighting and Displays, School of Physical and Mathematical Sciences, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore); Wei Sun, Xiao, E-mail: EXWSUN@ntu.edu.sg [LUMINOUS Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore); LUMINOUS Centre of Excellence for Semiconductor Lighting and Displays, School of Physical and Mathematical Sciences, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore); Department of Electronics and Electrical Engineering, South University of Science and Technology of China, Shenzhen, Guangdong 518055 (China); Volkan Demir, Hilmi, E-mail: VOLKAN@stanfordalumni.org [LUMINOUS Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore); LUMINOUS Centre of Excellence for Semiconductor Lighting and Displays, School of Physical and Mathematical Sciences, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore); Department of Electrical and Electronics, UNAM-Institute of Material Science and Nanotechnology, Bilkent University, Ankara TR-06800 (Turkey); Department of Physics, UNAM-Institute of Material Science and Nanotechnology, Bilkent University, Ankara TR-06800 (Turkey)

    2013-12-23

    Here, GaN/Al{sub x}Ga{sub 1-x}N heterostructures with a graded AlN composition, completely lacking external p-doping, are designed and grown using metal-organic-chemical-vapour deposition (MOCVD) system to realize three-dimensional hole gas (3DHG). The existence of the 3DHG is confirmed by capacitance-voltage measurements. Based on this design, a p-doping-free InGaN/GaN light-emitting diode (LED) driven by the 3DHG is proposed and grown using MOCVD. The electroluminescence, which is attributed to the radiative recombination of injected electrons and holes in InGaN/GaN quantum wells, is observed from the fabricated p-doping-free devices. These results suggest that the 3DHG can be an alternative hole source for InGaN/GaN LEDs besides common Mg dopants.

  3. Convergence properties of polynomial chaos approximations for L2 random variables.

    SciTech Connect (OSTI)

    Field, Richard V., Jr. (.,; .); Grigoriu, Mircea (Cornell University, Ithaca, NY)

    2007-03-01

    Polynomial chaos (PC) representations for non-Gaussian random variables are infinite series of Hermite polynomials of standard Gaussian random variables with deterministic coefficients. For calculations, the PC representations are truncated, creating what are herein referred to as PC approximations. We study some convergence properties of PC approximations for L{sub 2} random variables. The well-known property of mean-square convergence is reviewed. Mathematical proof is then provided to show that higher-order moments (i.e., greater than two) of PC approximations may or may not converge as the number of terms retained in the series, denoted by n, grows large. In particular, it is shown that the third absolute moment of the PC approximation for a lognormal random variable does converge, while moments of order four and higher of PC approximations for uniform random variables do not converge. It has been previously demonstrated through numerical study that this lack of convergence in the higher-order moments can have a profound effect on the rate of convergence of the tails of the distribution of the PC approximation. As a result, reliability estimates based on PC approximations can exhibit large errors, even when n is large. The purpose of this report is not to criticize the use of polynomial chaos for probabilistic analysis but, rather, to motivate the need for further study of the efficacy of the method.

  4. Long-run growth rate in a random multiplicative model (Journal Article) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Long-run growth rate in a random multiplicative model Citation Details In-Document Search Title: Long-run growth rate in a random multiplicative model We consider the long-run growth rate of the average value of a random multiplicative process x{sub i+1} = a{sub i}x{sub i} where the multipliers a{sub i}=1+ρexp(σW{sub i}-1/2 σ²t{sub i}) have Markovian dependence given by the exponential of a standard Brownian motion W{sub i}. The average value (x{sub n}) is given by the

  5. The Golden-Thompson inequality: Historical aspects and random matrix applications

    SciTech Connect (OSTI)

    Forrester, Peter J. Thompson, Colin J.

    2014-02-15

    The Golden-Thompson inequality, Tr?(e{sup A+B}) ? Tr?(e{sup A}e{sup B}) for A, B Hermitian matrices, appeared in independent works by Golden and Thompson published in 1965. Both of these were motivated by considerations in statistical mechanics. In recent years the Golden-Thompson inequality has found applications to random matrix theory. In this article, we detail some historical aspects relating to Thompson's work, giving in particular a hitherto unpublished proof due to Dyson, and correspondence with Plya. We show too how the 2 2 case relates to hyperbolic geometry, and how the original inequality holds true with the trace operation replaced by any unitarily invariant norm. In relation to the random matrix applications, we review its use in the derivation of concentration type lemmas for sums of random matrices due to Ahlswede-Winter, and Oliveira, generalizing various classical results.

  6. Averaged Description of Flow (Steady and Transient) and Nonreactive Solute Transport in Random Porous Media

    SciTech Connect (OSTI)

    Schvidler, M.; Karasaki, K.

    2011-06-15

    In previous papers (Shvidler and Karasaki, 1999, 2001, 2005, and 2008) we presented and analyzed an approach for finding the general forms of exactly averaged equations of flow and transport in porous media. We studied systems of basic equations for steady flow with sources in unbounded domains with stochastically homogeneous conductivity fields. A brief analysis of exactly averaged equations of nonsteady flow and nonreactive solute transport was also presented. At the core of this approach is the existence of appropriate random Green's functions. For example, we showed that in the case of a 3-dimensional unbounded domain the existence of appropriate random Green's functions is sufficient for finding the exact nonlocal averaged equations for flow velocity using the operator with a unique kernel-vector. Examination of random fields with global symmetry (isotropy, transversal isotropy and orthotropy) makes it possible to describe significantly different types of averaged equations with nonlocal unique operators. It is evident that the existence of random Green's functions for physical linear processes is equivalent to assuming the existence of some linear random operators for appropriate stochastic equations. If we restricted ourselves to this assumption only, as we have done in this paper, we can study the processes in any dimensional bounded or unbounded fields and in addition, cases in which the random fields of conductivity and porosity are stochastically nonhomogeneous, nonglobally symmetrical, etc.. It is clear that examining more general cases involves significant difficulty and constricts the analysis of structural types for the processes being studied. Nevertheless, we show that we obtain the essential information regarding averaged equations for steady and transient flow, as well as for solute transport.

  7. Full Coverage Shaped Hole Film Cooling in an Accelerating Boundary Layer with High Free-Stream Turbulence

    SciTech Connect (OSTI)

    Ames, Forrest E.; Kingery, Joseph E.

    2015-06-17

    Full coverage shaped-hole film cooling and downstream heat transfer measurements have been acquired in the accelerating flows over a large cylindrical leading edge test surface. The shaped holes had an 8° lateral expansion angled at 30° to the surface with spanwise and streamwise spacings of 3 diameters. Measurements were conducted at four blowing ratios, two Reynolds numbers and six well documented turbulence conditions. Film cooling measurements were acquired over a four to one range in blowing ratio at the lower Reynolds number and at the two lower blowing ratios for the higher Reynolds number. The film cooling measurements were acquired at a coolant to free-stream density ratio of approximately 1.04. The flows were subjected to a low turbulence condition (Tu = 0.7%), two levels of turbulence for a smaller sized grid (Tu = 3.5%, and 7.9%), one turbulence level for a larger grid (8.1%), and two levels of turbulence generated using a mock aero-combustor (Tu = 9.3% and 13.7%). Turbulence level is shown to have a significant influence in mixing away film cooling coverage progressively as the flow develops in the streamwise direction. Effectiveness levels for the aero-combustor turbulence condition are reduced to as low as 20% of low turbulence values by the furthest downstream region. The film cooling discharge is located close to the leading edge with very thin and accelerating upstream boundary layers. Film cooling data at the lower Reynolds number, show that transitional flows have significantly improved effectiveness levels compared with turbulent flows. Downstream effectiveness levels are very similar to slot film cooling data taken at the same coolant flow rates over the same cylindrical test surface. However, slots perform significantly better in the near discharge region. These data are expected to be very useful in grounding computational predictions of full coverage shaped hole film cooling with elevated turbulence levels and acceleration. IR measurements were performed for the two lowest turbulence levels to document the spanwise variation in film cooling effectiveness and heat transfer.

  8. ENHANCED ACCRETION RATES OF STARS ON SUPERMASSIVE BLACK HOLES BY STAR-DISK INTERACTIONS IN GALACTIC NUCLEI

    SciTech Connect (OSTI)

    Just, Andreas; Yurin, Denis; Makukov, Maxim; Berczik, Peter; Omarov, Chingis; Spurzem, Rainer; Vilkoviskij, Emmanuil Y.

    2012-10-10

    We investigate the dynamical interaction of a central star cluster surrounding a supermassive black hole (SMBH) and a central accretion disk (AD). The dissipative force acting on stars in the disk leads to an enhanced mass flow toward the SMBH and to an asymmetry in the phase space distribution due to the rotating AD. The AD is considered as a stationary Keplerian rotating disk, which is vertically extended in order to employ a fully self-consistent treatment of stellar dynamics including the dissipative force originating from star-gas ram pressure effects. The stellar system is treated with a direct high-accuracy N-body integration code. A star-by-star representation, desirable in N-body simulations, cannot be extended to real particle numbers yet. Hence, we carefully discuss the scaling behavior of our model with regard to particle number and tidal accretion radius. The main idea is to find a family of models for which the ratio of two-body relaxation time and dissipation time (for kinetic energy of stellar orbits) is constant, which then allows us to extrapolate our results to real parameters of galactic nuclei. Our model is derived from basic physical principles and as such it provides insight into the role of physical processes in galactic nuclei, but it should be regarded as a first step toward more realistic and more comprehensive simulations. Nevertheless, the following conclusions appear to be robust: the star accretion rate onto the AD and subsequently onto the SMBH is enhanced by a significant factor compared to purely stellar dynamical systems neglecting the disk. This process leads to enhanced fueling of central disks in active galactic nuclei (AGNs) and to an enhanced rate of tidal stellar disruptions. Such disruptions may produce electromagnetic counterparts in the form of observable X-ray flares. Our models improve predictions for their rates in quiescent galactic nuclei. We do not yet model direct stellar collisions in the gravitational potential well of the black hole, which could further enhance the growth rate of the black hole. Our models are relevant for quiescent galactic nuclei, because all our mass accretion rates would give rise to luminosities much smaller than the Eddington luminosity. To reach Eddington luminosities, outflows, and feedback as in the most active QSOs, other scenarios are needed, such as gas accretion after galaxy mergers. However, for AGNs close to the Eddington limit, this process may not serve as the dominant accretion process due to the long timescale.

  9. Using histograms to introduce randomization in the generation of ensembles of decision trees

    DOE Patents [OSTI]

    Kamath, Chandrika; Cantu-Paz, Erick; Littau, David

    2005-02-22

    A system for decision tree ensembles that includes a module to read the data, a module to create a histogram, a module to evaluate a potential split according to some criterion using the histogram, a module to select a split point randomly in an interval around the best split, a module to split the data, and a module to combine multiple decision trees in ensembles. The decision tree method includes the steps of reading the data; creating a histogram; evaluating a potential split according to some criterion using the histogram, selecting a split point randomly in an interval around the best split, splitting the data, and combining multiple decision trees in ensembles.

  10. A random access memory immune to single event upset using a T-Resistor

    DOE Patents [OSTI]

    Ochoa, A. Jr.

    1987-10-28

    In a random access memory cell, a resistance ''T'' decoupling network in each leg of the cell reduces random errors caused by the interaction of energetic ions with the semiconductor material forming the cell. The cell comprises two parallel legs each containing a series pair of complementary MOS transistors having a common gate connected to the node between the transistors of the opposite leg. The decoupling network in each leg is formed by a series pair of resistors between the transistors together with a third resistor interconnecting the junction between the pair of resistors and the gate of the transistor pair forming the opposite leg of the cell. 4 figs.

  11. Random access memory immune to single event upset using a T-resistor

    DOE Patents [OSTI]

    Ochoa, Jr., Agustin

    1989-01-01

    In a random access memory cell, a resistance "T" decoupling network in each leg of the cell reduces random errors caused by the interaction of energetic ions with the semiconductor material forming the cell. The cell comprises two parallel legs each containing a series pair of complementary MOS transistors having a common gate connected to the node between the transistors of the opposite leg. The decoupling network in each leg is formed by a series pair of resistors between the transistors together with a third resistor interconnecting the junction between the pair of resistors and the gate of the transistor pair forming the opposite leg of the cell.

  12. Methods and optical fibers that decrease pulse degradation resulting from random chromatic dispersion

    DOE Patents [OSTI]

    Chertkov, Michael; Gabitov, Ildar

    2004-03-02

    The present invention provides methods and optical fibers for periodically pinning an actual (random) accumulated chromatic dispersion of an optical fiber to a predicted accumulated dispersion of the fiber through relatively simple modifications of fiber-optic manufacturing methods or retrofitting of existing fibers. If the pinning occurs with sufficient frequency (at a distance less than or are equal to a correlation scale), pulse degradation resulting from random chromatic dispersion is minimized. Alternatively, pinning may occur quasi-periodically, i.e., the pinning distance is distributed between approximately zero and approximately two to three times the correlation scale.

  13. Acceleration of relativistic electrons by magnetohydrodynamic turbulence: Implications for non-thermal emission from black hole accretion disks

    SciTech Connect (OSTI)

    Lynn, Jacob W.; Quataert, Eliot; Chandran, Benjamin D. G.; Parrish, Ian J.

    2014-08-10

    We use analytic estimates and numerical simulations of test particles interacting with magnetohydrodynamic (MHD) turbulence to show that subsonic MHD turbulence produces efficient second-order Fermi acceleration of relativistic particles. This acceleration is not well described by standard quasi-linear theory but is a consequence of resonance broadening of wave-particle interactions in MHD turbulence. We provide momentum diffusion coefficients that can be used for astrophysical and heliospheric applications and discuss the implications of our results for accretion flows onto black holes. In particular, we show that particle acceleration by subsonic turbulence in radiatively inefficient accretion flows can produce a non-thermal tail in the electron distribution function that is likely important for modeling and interpreting the emission from low-luminosity systems such as Sgr A* and M87.

  14. Kondo hole behavior in Ce{sub 0.97} La{sub 0.03}Pd{sub 3}

    SciTech Connect (OSTI)

    Lawrence, J.M.; Graf, T.; Hundley, M.F.; Mandrus, D.; Thompson, J.D. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Lacerda, A.; Torikachvili, M.S. [National High Magnetic Field Laboratory, Pulse Facility, Los Alamos, New Mexico 87545 (United States)] [National High Magnetic Field Laboratory, Pulse Facility, Los Alamos, New Mexico 87545 (United States); Sarrao, J.L.; Fisk, Z. [National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306 (United States)] [National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306 (United States)

    1996-05-01

    We present results for the resistivity, the magnetoresistance, and the specific heat of Ce{sub 0.97}La{sub 0.03}Pd{sub 3} and CePd{sub 3}. The impurity contributions to these measurements follow the predictions of the single-impurity Kondo model for a Kondo temperature {ital T}{sub {ital L}}{approx_equal}65 K, assuming that the impurity behaves as a crystal-field split ({Gamma}{sub 7}) doublet. Assuming a {ital J}=5/2 impurity, the value of {ital T}{sub {ital L}} needed to fit these experiments varies from 65 to 125 K. The contribution to the susceptibility may be too small to be explained by the model. These results address whether the nonmagnetic impurity behaves as a Kondo hole. {copyright} {ital 1996 The American Physical Society.}

  15. THE DYNAMICS, APPEARANCE, AND DEMOGRAPHICS OF RELATIVISTIC JETS TRIGGERED BY TIDAL DISRUPTION OF STARS IN QUIESCENT SUPERMASSIVE BLACK HOLES

    SciTech Connect (OSTI)

    De Colle, Fabio; Guillochon, James; Naiman, Jill; Ramirez-Ruiz, Enrico E-mail: jfg@ucolick.org E-mail: enrico@ucolick.org

    2012-12-01

    We examine the consequences of a model in which relativistic jets can be triggered in quiescent massive black holes when a geometrically thick and hot accretion disk forms as a result of the tidal disruption of a star. To estimate the power, thrust, and lifetime of the jet, we use the mass accretion history onto the black hole as calculated by detailed hydrodynamic simulations of the tidal disruption of stars. We go on to determine the states of the interstellar medium in various types of quiescent galactic nuclei, and describe how this external matter can affect jets propagating through it. We use this information, together with a two-dimensional hydrodynamic model of the structure of the relativistic flow, to study the dynamics of the jet, the propagation of which is regulated by the density stratification of the environment and by its injection history. The breaking of symmetry involved in transitioning from one to two dimensions is crucial and leads to qualitatively new phenomena. At early times, as the jet power increases, the high pressure of the cocoon collimates the jet, increasing its shock velocity as compared to that of spherical models. We show that small velocity gradients, induced near or at the source, steepen into internal shocks and provide a source of free energy for particle acceleration and radiation along the jet's channel. The jets terminate at a working surface where they interact strongly with the surrounding medium through a combination of shock waves and instabilities; a continuous flow of relativistic fluid emanating from the nucleus supplies this region with mass, momentum, and energy. Information about the t {sup -5/3} decrease in power supply propagates within the jet at the internal sound speed. As a result, the internal energy at the jet head continues to accumulate until long after the peak feeding rate is reached. An appreciable time delay is thus expected between peaks in the short-wavelength radiation emanating near the jet's origin and the long-wavelength emission produced at the head of the jet. Many of the observed properties of the Swift 1644+57/GRB 110328A event can be understood as resulting from accretion onto and jets driven by a 10{sup 6} M {sub Sun} central mass black hole following the disruption of a sun-like star. With the inclusion of a stochastic contribution to the luminosity due to variations in the feeding rate driven by instabilities near the tidal radius, we find that our model can explain the X-ray light curve without invoking a rarely occurring deep encounter. In conjunction with the number density of black holes in the local universe, we hypothesize that the conditions required to produce the Swift event are not anomalous, but are in fact representative of the jet-driven flare population arising from tidal disruptions.

  16. Primordial black holes with mass 10{sup 16}?10{sup 17} g and reionization of the Universe

    SciTech Connect (OSTI)

    Belotsky, K.M.; Kirillov, A.A. E-mail: kirillov-aa@yandex.ru

    2015-01-01

    Primordial black holes (PBHs) with mass 10{sup 16}?10{sup 17} g almost escape constraints from observations so could essentially contribute to dark matter density. Hawking evaporation of such PBHs produces with a steady rate ?- and e{sup }-radiations in MeV energy range, which can be absorbed by ordinary matter. Simplified estimates show that a small fraction of evaporated energy had to be absorbed by baryonic matter what can turn out to be enough to heat the matter so it is fully ionized at the redshift z?5...10. The result is found to be close to a borderline case where the effect appears, what makes it sensitive to the approximation used. In our approximation, degree of gas ionization reaches 50-100% by z?5 for PBH mass (3...7)נ10{sup 16} g with their abundance corresponding to the upper limit.

  17. Pseudopotential calculations of electron and hole addition spectra of InAs, InP, and Si quantum dots

    SciTech Connect (OSTI)

    Franceschetti, Alberto; Zunger, Alex

    2000-07-15

    The electron and hole addition energies, the quasiparticle gap, and the optical gap of InAs, InP, and Si quantum dots are calculated using microscopic pseudopotential wave functions. The effects of the dielectric mismatch between the quantum dot and the surrounding material are included using a realistic profile for the dielectric constant {epsilon}(r). We find that the addition energies and the quasiparticle gap depend strongly on the dielectric constant of the environment {epsilon}{sub out}, while the optical gap is rather insensitive to {epsilon}{sub out}. We compare our results with recent tunneling spectroscopy measurements for InAs nanocrystals, finding excellent agreement. Our calculations for the addition energies and the quasiparticle gap of InP and Si nanocrystals serve as predictions for future experiments. (c) 2000 The American Physical Society.

  18. Formation of BaSi{sub 2} heterojunction solar cells using transparent MoO{sub x} hole transport layers

    SciTech Connect (OSTI)

    Du, W.; Takabe, R.; Baba, M.; Takeuchi, H.; Toko, K.; Hara, K. O.; Usami, N.; Suemasu, T.

    2015-03-23

    Heterojunction solar cells that consist of 15?nm thick molybdenum trioxide (MoO{sub x}, x?hole transport layer and 600?nm thick unpassivated or passivated n-BaSi{sub 2} layers were demonstrated. Rectifying current-voltage characteristics were observed when the surface of BaSi{sub 2} was exposed to air. When the exposure time was decreased to 1?min, an open circuit voltage of 200?mV and a short circuit current density of 0.5?mA/cm{sup 2} were obtained under AM1.5 illumination. The photocurrent density under a reverse bias voltage of ?1 V reached 25?mA/cm{sup 2}, which demonstrates the significant potential of BaSi{sub 2} for solar cell applications.

  19. GRB060218 AS A TIDAL DISRUPTION OF A WHITE DWARF BY AN INTERMEDIATE-MASS BLACK HOLE

    SciTech Connect (OSTI)

    Shcherbakov, Roman V.; Reynolds, Christopher S.; Pe'er, Asaf; Haas, Roland; Bode, Tanja; Laguna, Pablo

    2013-06-01

    The highly unusual pair of a gamma-ray burst (GRB) GRB060218 and an associated supernova, SN2006aj, has puzzled theorists for years. A supernova shock breakout and a jet from a newborn stellar mass compact object have been proposed to explain this pair's multiwavelength signature. Alternatively, we propose that the source is naturally explained by another channel: the tidal disruption of a white dwarf (WD) by an intermediate-mass black hole (IMBH). This tidal disruption is accompanied by a tidal pinching, which leads to the ignition of a WD and a supernova. Some debris falls back onto the IMBH, forms a disk, which quickly amplifies the magnetic field, and launches a jet. We successfully fit soft X-ray spectra with the Comptonized blackbody emission from a jet photosphere. The optical/UV emission is consistent with self-absorbed synchrotron emission from the expanding jet front. The temporal dependence of the accretion rate M-dot (t) in a tidal disruption provides a good fit to the soft X-ray light curve. The IMBH mass is found to be about 10{sup 4} M{sub Sun} in three independent estimates: (1) fitting the tidal disruption M-dot (t) to the soft X-ray light curve, (2) computing the jet base radius in a jet photospheric emission model, and (3) inferring the mass of the central black hole based on the host dwarf galaxy's stellar mass. The position of the supernova is consistent with the center of the host galaxy, while the low supernova ejecta mass is consistent with that of a WD. The high expected rate of tidal disruptions in dwarf galaxies is consistent with one source observed by the Swift satellite over several years at a distance of 150 Mpc measured for GRB060218. Encounters with WDs provide much fuel for the growth of IMBHs.

  20. Electron and hole gas in modulation-doped GaAs/Al{sub 1-x}Ga{sub x}As radial heterojunctions

    SciTech Connect (OSTI)

    Bertoni, Andrea; Royo, Miquel; Mahawish, Farah; Goldoni, Guido

    2011-11-15

    We perform self-consistent Schroedinger-Poisson calculations with exchange and correlation corrections to determine the electron and hole gas in a radial heterojunction formed in a GaAs/AlGaAs core-multi-shell nanowire, which is either n- or p-doped. We show that the electron and hole gases can be tuned to different localizations and symmetries inside the core as a function of the doping density/gate potential. Contrary to planar heterojunctions, conduction electrons do not form a uniform 2D electron gas (2DEG) localized at the GaAs/AlGaAs interface, but rather show a transition between an isotropic, cylindrical distribution deep in the GaAs core (low doping) and a set of six tunnel-coupled quasi-1D channels at the edges of the interface (high doping). Holes, on the other hand, are much more localized at the GaAs/AlGaAs interface. At low doping, they present an additional localization pattern with six separated 2DEGs strips. The field generated by a back-gate may easily deform the electron or hole gas, breaking the sixfold symmetry. Single 2DEGs at one interface or multiple quasi-1D channels are shown to form as a function of voltage intensity, polarity, and carrier type.