WorldWideScience

Sample records for spectral hole burning

  1. Laser linewidth narrowing using transient spectral hole burning

    Energy Technology Data Exchange (ETDEWEB)

    Thiel, Charles W.; Cone, Rufus L. [Department of Physics, Montana State University, Bozeman, MT 59715 (United States); Böttger, Thomas, E-mail: tbottger@usfca.edu [Department of Physics and Astronomy, 2130 Fulton Street, University of San Francisco, San Francisco, CA 94117 (United States)

    2014-08-01

    We demonstrate significant narrowing of laser linewidths by high optical density materials with inhomogeneously broadened absorption. As a laser propagates through the material, the nonlinear spectral hole burning process causes a progressive self-filtering of the laser spectrum, potentially reaching values less than the homogeneous linewidth. The transient spectral hole dynamically adjusts itself to the instantaneous frequency of the laser, passively suppressing laser phase noise and side modes over the entire material absorption bandwidth without the need for electronic or optical feedback to the laser. Wide bandwidth laser phase noise suppression was demonstrated using Er{sup 3+} doped Y{sub 2}SiO{sub 5} and LiNbO{sub 3} at 1.5 μm by employing time-delayed self-heterodyne detection of an external cavity diode laser to study the spectral narrowing effect. Our method is not restricted to any particular wavelength or laser system and is attractive for a range of applications where ultra-low phase noise sources are required. - Highlights: • We demonstrate significant laser linewidths narrowing by high optical density materials. • Nonlinear spectral hole burning causes progressive self-filtering of laser spectrum. • Filter dynamically adjusts itself to the instantaneous frequency of the laser. • Demonstrated at 1.5 μm in Er{sup 3+} doped Y{sub 2}SiO{sub 5} and LiNbO{sub 3}. • Linewidth filtering is not restricted to any particular wavelength or laser system.

  2. Photoinduced electron transfer and persistent spectral hole-burning in natural emerald.

    Science.gov (United States)

    Riesen, Hans

    2011-06-02

    Wavelength-selective excited-state lifetime measurements and absorption, luminescence, and hole-burning spectra of a natural African emerald crystal are reported. The (2)E excited-state lifetime displays an extreme wavelength dependence, varying from 190 to 37 μs within 1.8 nm of the R(1)-line. Overall, the excited state is strongly quenched, in comparison to laboratory-created emerald (τ=1.3 ms), with an average quenching rate of ∼6 × 10(3) s(-1) at 2.5 K. This quenching is attributed to photoinduced electron transfer caused by a relatively high concentration of Fe(2+) ions. The forward electron-transfer rate, k(f), from the nearest possible Fe(2+) sites at around 5 Å is estimated to be ∼20 × 10(3) s(-1) at 2.5 K. The photoreductive quenching of the excited Cr(3+) ions by Fe(2+) is followed by rapid electron back-transfer in the ground state upon deactivation. The exchange interaction based quenching can be modeled by assuming a random quencher distribution within the possible Fe(2+) sites with the forward electron-transfer rate, k(f), given as a function of acceptor-donor separation R by exp[(R(f)-R)/a(f)]; R(f) and a(f) values of 13.5 and 2.7 Å are obtained at 2.5 K. The electron transfer/back-transfer reorganizes the local crystal lattice, occasionally leading to a minor variation of the short-range structure around the Cr(3+) ions. This provides a mechanism for spectral hole-burning for which a moderately high quantum efficiency of about ∼0.005% is observed. Spectral holes are subject to spontaneous hole-filling and spectral diffusion, and both effects can be quantified within the standard two-level systems for non-photochemical hole-burning. Importantly, the absorbance increases on both sides of broad spectral holes, and isosbestic points are observed, in accord with the expected distribution of the "photoproduct" in a non-photochemical hole-burning process. © 2011 American Chemical Society

  3. Optical decoherence and persistent spectral hole burning in Tm3+:LiNbO3

    International Nuclear Information System (INIS)

    Thiel, C.W.; Sun, Y.; Boettger, T.; Babbitt, W.R.; Cone, R.L.

    2010-01-01

    We report studies of decoherence and spectral hole burning for the 794 nm optical transition of thulium-doped lithium niobate. In addition to transient spectral holes due to the 3 H 4 and 3 F 4 excited states of Tm 3+ , persistent spectral holes with lifetimes of up to minutes were observed when a magnetic field of a few hundred Gauss was applied. The observed anti-hole structure identified the hole burning mechanism as population storage in the 169 Tm nuclear hyperfine levels. In addition, the magnetic field was effective in suppressing spectral diffusion, increasing the phase memory lifetime from 11 μs at zero field to 23 μs in a field of 320 Gauss applied along the crystal's c-axis. Coupling between Tm 3+ and the 7 Li and 93 Nb spins in the host lattice was also observed and a quadrupole shift of 22 kHz was measured for 7 Li at 1.7 K. A Stark shift of 18 kHz cm/V was measured for the optical transition with the electric field applied parallel to the c-axis.

  4. Spatial hole burning and spectral stability of a quantum-dot laser

    International Nuclear Information System (INIS)

    Savelyev, A. V.; Korenev, V. V.; Maximov, M. V.; Zhukov, A. E.

    2015-01-01

    The inhomogeneous intensity distribution of the optical model along the axis of a semiconductor quantum-dot laser results in spatial hole burning. The influence of this phenomenon on the stability of the multifrequency emission spectrum is studied when the optical transition of the quantum dots is characterized by considerable homogeneous broadening. The results of two models—in which inhomogeneous broadening is disregarded and taken into account—regarding the stability of the radiation spectrum under the influence of slight variation of the spectral loss dependence in the resonator are compared. Inhomogeneous distribution of the charge carriers (spatial hole burning) is found to be a critical factor in determining the form and stability of the spectrum

  5. Spatial hole burning and spectral stability of a quantum-dot laser

    Energy Technology Data Exchange (ETDEWEB)

    Savelyev, A. V., E-mail: savelev@mail.ioffe.ru; Korenev, V. V.; Maximov, M. V.; Zhukov, A. E. [Russian Academy of Sciences, Nanotechnology Center, St. Petersburg Academic University (Russian Federation)

    2015-11-15

    The inhomogeneous intensity distribution of the optical model along the axis of a semiconductor quantum-dot laser results in spatial hole burning. The influence of this phenomenon on the stability of the multifrequency emission spectrum is studied when the optical transition of the quantum dots is characterized by considerable homogeneous broadening. The results of two models—in which inhomogeneous broadening is disregarded and taken into account—regarding the stability of the radiation spectrum under the influence of slight variation of the spectral loss dependence in the resonator are compared. Inhomogeneous distribution of the charge carriers (spatial hole burning) is found to be a critical factor in determining the form and stability of the spectrum.

  6. Transient spectral hole burning observed on the single-molecule level in terrylene-doped biphenyl

    International Nuclear Information System (INIS)

    Pärs, M.; Palm, V.; Kikas, J.

    2014-01-01

    We use the method of fluorescence correlation spectroscopy to analyze the single-molecule (SM) spectroscopy data earlier recorded for a special type of terrylene SM impurity center (referred as “spectrally confined unstable molecule”, SCM) in an incommensurate single crystal of biphenyl. The SCM's SM line seems to be chaotically jumping around within a broad “spectral envelope” and was first considered being subject to a peculiar spectral diffusion behavior. However, our correlation analysis reveals that all the features observed for SCM at 1.8 K are consistent with an assumption that this SM center participates in a process of reversible (transient) spectral hole burning (THB) earlier observed for terrylene-doped polycrystalline biphenyl. No observations of THB processes on SM level have been so far reported for this impurity system, partially due to a low concentration of relevant impurity centers. Another reason making searching for such centers experimentally challenging is an unusual SM line behavior: the photoinduced transition to a metastable “dark state” leads to the SM line saturational broadening, which is much stronger than the triplet broadening. Hence required prolonged observation is often prevented by an SM act of persistent spectral hole burning. - Highlights: • SCM—special type of terrylene single-molecule center in incommensurate biphenyl. • An unusually stable SCM was investigated during several hours at T=1.8 K. • SCM undergoes photoinduced transitions to an unknown metastable “dark state” (DS). • The long DS lifetime causes strong saturational broadening of SCM spectral line. • SCM participates in an earlier observed process of transient hole burning

  7. Optical decoherence and persistent spectral hole burning in Tm{sup 3+}:LiNbO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Thiel, C.W., E-mail: thiel@physics.montana.ed [Department of Physics, Montana State University, EPS 264, Bozeman, MT 59717 (United States); Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Sun, Y. [Department of Physics, University of South Dakota, Vermillion, SD 57069 (United States); Boettger, T. [Department of Physics, University of San Francisco, San Francisco, CA 94117 (United States); Babbitt, W.R. [Department of Physics, Montana State University, EPS 264, Bozeman, MT 59717 (United States); Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Cone, R.L. [Department of Physics, Montana State University, EPS 264, Bozeman, MT 59717 (United States)

    2010-09-15

    We report studies of decoherence and spectral hole burning for the 794 nm optical transition of thulium-doped lithium niobate. In addition to transient spectral holes due to the {sup 3}H{sub 4} and {sup 3}F{sub 4} excited states of Tm{sup 3+}, persistent spectral holes with lifetimes of up to minutes were observed when a magnetic field of a few hundred Gauss was applied. The observed anti-hole structure identified the hole burning mechanism as population storage in the {sup 169}Tm nuclear hyperfine levels. In addition, the magnetic field was effective in suppressing spectral diffusion, increasing the phase memory lifetime from 11 {mu}s at zero field to 23 {mu}s in a field of 320 Gauss applied along the crystal's c-axis. Coupling between Tm{sup 3+} and the {sup 7}Li and {sup 93}Nb spins in the host lattice was also observed and a quadrupole shift of 22 kHz was measured for {sup 7}Li at 1.7 K. A Stark shift of 18 kHz cm/V was measured for the optical transition with the electric field applied parallel to the c-axis.

  8. Saturated multikilovolt x-ray amplification with Xe clusters: single-pulse observation of Xe(L) spectral hole burning

    International Nuclear Information System (INIS)

    Borisov, Alex B; Davis, Jack; Song, Xiangyang; Koshman, Yevgeniya; Dai Yang; Boyer, Keith; Rhodes, Charles K

    2003-01-01

    Single-pulse measurements of spectral hole burning of Xe(L) 3d → 2p hollow atom transition arrays observed from a self-trapped plasma channel provide new information on the dynamics of saturated amplification in the λ ∼ 2.8-2.9 A region. The spectral hole burning on transitions in the Xe 34+ and Xe 35+ arrays reaches full suppression of the spontaneous emission and presents a corresponding width Δ h-bar ω x ∼ = 60 eV, a value adequate for efficient amplification of multikilovolt x-ray pulses down to a limiting length τ x ∼ 30 as. The depth of the suppression at 2.86 A indicates that the gain-to-loss ratio is ≥10. An independent determination of the x-ray pulse energy from damage produced on the surface of a Ti foil in the far field of the source gives a pulse energy of 20-30 μJ, a range that correlates well with the observation of the spectral hole burning and indicates an overall extraction efficiency of ∼10%. (letter to the editor)

  9. Spectral hole-burning and carrier-heating dynamics in InGaAs quantum-dot amplifiers

    DEFF Research Database (Denmark)

    Borri, Paola; Langbein, Wolfgang Werner; Hvam, Jørn Märcher

    2000-01-01

    recovery of the spectral hole within ~100 fs is measured, comparable to bulk and quantum-well amplifiers, which is contradicting a carrier relaxation bottleneck in electrically pumped QD devices. The CH dynamics in the QD is quantitatively compared with results on an InGaAsP bulk amplifier. Reduced CH......The ultrafast gain and index dynamics in a set of InAs-InGaAs-GaAs quantum-dot (QD) amplifiers are measured at room temperature with femtosecond resolution. The role of spectral hole-burning (SHB) and carrier heating (CH) in the recovery of gain compression is investigated in detail. An ultrafast...

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

    Energy Technology Data Exchange (ETDEWEB)

    Milanovich, Nebojsa [Iowa State Univ., Ames, IA (United States)

    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.

  11. Optical decoherence times and spectral diffusion in an Er-doped optical fiber measured by two-pulse echoes, stimulated photon echoes, and spectral hole burning

    International Nuclear Information System (INIS)

    Macfarlane, R.M.; Sun, Y.; Sellin, P.B.; Cone, R.L.

    2007-01-01

    Two-pulse and stimulated photon echoes and spectral hole burning were measured on the transition from the lowest component of the 4 I 15/2 manifold to the lowest component of 4 I 13/2 of Er 3+ in a silicate optical fiber at 1.6 K. The two-pulse echo decays gave decoherence times as long as 230 ns for magnetic fields above 2 T. A large field dependent contribution to the homogeneous line width of >2 MHz was found and interpreted in terms of coupling to magnetic tunneling modes (TLS) in the glass. The stimulated echoes measured at 2 T showed spectral diffusion of 0.8 MHz/decade of time between 0.4 and 500 μs. Spectral diffusion in this high field region is attributed to coupling to elastic TLS modes which have a distribution of flip rates in glasses. Time-resolved spectral hole burning at very low field showed stronger spectral diffusion of 5.7 MHz/decade of time, attributed to coupling to magnetic spin-elastic TLS modes

  12. Spectral hole-burning and carrier-heating dynamics in quantum-dot amplifiers: Comparison with bulk amplifiers

    DEFF Research Database (Denmark)

    Borri, P.; Langbein, W.; Hvam, Jørn Märcher

    2001-01-01

    The ultrafast gain dynamics in an electrically pumped InAs/InGaAs/GaAs quantum-dot amplifier are measured at room temperature with femtosecond resolution, and compared with results on an InGaAsP bulk amplifier. The role of spectral hole burning and carrier heating in the recovery of the gain...

  13. Engineering dissipation with phononic spectral hole burning

    Science.gov (United States)

    Behunin, R. O.; Kharel, P.; Renninger, W. H.; Rakich, P. T.

    2017-03-01

    Optomechanics, nano-electromechanics, and integrated photonics have brought about a renaissance in phononic device physics and technology. Central to this advance are devices and materials supporting ultra-long-lived photonic and phononic excitations that enable novel regimes of classical and quantum dynamics based on tailorable photon-phonon coupling. Silica-based devices have been at the forefront of such innovations for their ability to support optical excitations persisting for nearly 1 billion cycles, and for their low optical nonlinearity. While acoustic phonon modes can persist for a similar number of cycles in crystalline solids at cryogenic temperatures, it has not been possible to achieve such performance in silica, as silica becomes acoustically opaque at low temperatures. We demonstrate that these intrinsic forms of phonon dissipation are greatly reduced (by >90%) by nonlinear saturation using continuous drive fields of disparate frequencies. The result is a form of steady-state phononic spectral hole burning that produces a wideband transparency window with optically generated phonon fields of modest (nW) powers. We developed a simple model that explains both dissipative and dispersive changes produced by phononic saturation. Our studies, conducted in a microscale device, represent an important step towards engineerable phonon dynamics on demand and the use of glasses as low-loss phononic media.

  14. Optical decoherence and persistent spectral hole burning in Er3+:LiNbO3

    International Nuclear Information System (INIS)

    Thiel, C.W.; Macfarlane, R.M.; Boettger, T.; Sun, Y.; Cone, R.L.; Babbitt, W.R.

    2010-01-01

    Developing new resonant optical materials for spatial-spectral holography and quantum information applications requires detailed knowledge of the decoherence and population relaxation dynamics for the quantum states involved in the optical transitions, motivating the need for fundamental material studies. We report recent progress in studying these properties in erbium-doped lithium niobate at liquid helium temperatures. The influence of temperature, applied magnetic fields, measurement timescale, and dopant concentration were probed using photon echo spectroscopy and time-resolved spectral hole burning on the 1532 nm transition of Er 3+ :LiNbO 3 . Effects of spectral diffusion due to interactions between Er 3+ ions and between the Er 3+ ion and 7 Li and 93 Nb nuclear spins in the host lattice were observed. In addition, long-lived persistent spectral storage of seconds to minutes was observed due to non-equilibrium population redistribution among superhyperfine states.

  15. Optical decoherence and persistent spectral hole burning in Er{sup 3+}:LiNbO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Thiel, C.W., E-mail: thiel@physics.montana.ed [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Macfarlane, R.M. [Department of Physics, Montana State University, Bozeman, MT 59717 (United States); IBM Almaden Research Center, San Jose, CA 95120 (United States); Boettger, T. [Department of Physics, University of San Francisco, San Francisco, CA 94117 (United States); Sun, Y. [Department of Physics, University of South Dakota, Vermillion, SD 57069 (United States); Cone, R.L. [Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Babbitt, W.R. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Department of Physics, Montana State University, Bozeman, MT 59717 (United States)

    2010-09-15

    Developing new resonant optical materials for spatial-spectral holography and quantum information applications requires detailed knowledge of the decoherence and population relaxation dynamics for the quantum states involved in the optical transitions, motivating the need for fundamental material studies. We report recent progress in studying these properties in erbium-doped lithium niobate at liquid helium temperatures. The influence of temperature, applied magnetic fields, measurement timescale, and dopant concentration were probed using photon echo spectroscopy and time-resolved spectral hole burning on the 1532 nm transition of Er{sup 3+}:LiNbO{sub 3}. Effects of spectral diffusion due to interactions between Er{sup 3+} ions and between the Er{sup 3+} ion and {sup 7}Li and {sup 93}Nb nuclear spins in the host lattice were observed. In addition, long-lived persistent spectral storage of seconds to minutes was observed due to non-equilibrium population redistribution among superhyperfine states.

  16. Aspects of hole-burning and spectro-temporal holography in molecular doped solids

    International Nuclear Information System (INIS)

    Galap, J.-P.

    2006-01-01

    The persistent spectral hole-burning (PSHB) phenomenon has been known since 1974. It is still an important research area for the study of the intimacy of complex molecular systems in the solid state, revealing high-resolution spectra, photophysics, photochemistry, and dynamics of molecular doped amorphous media, organic as well as inorganic. From another point of view, PSHB allows the engraving of any spectral structures in the inhomogeneous absorption band profile of molecular doped amorphous hosts or ion doped crystals cooled down to liquid helium temperatures. Therefore, a PSHB material is programmable in the spectral domain and consequently it can be transformed in an optical processor capable of achieving user-defined optical functions. Some aspects of both fields are illustrated in the present paper. Concerning the search for efficient PSHB materials, the hole-burning performances and the photophysics of polymer and xerogel based systems are compared. The problem of high-temperature persistent spectral hole-burning materials and the search for new frequency selective photosensitive systems for fast optical pulse processing at 800 nm are considered. Regarding the points treated, inorganic hosts based on silicate xerogels or porous glasses have shown the best results. Moreover, by combining inorganic and organic capabilities or by grafting organic species to the host, hybrid xerogels have not yet revealed all possibilities. Also, the interest of two-photon materials for engraving spectral features with near-infrared or infrared light is developed. As an introduction to possible applications of PSHB material, the basics of spectro-temporal holography are remembered and a demonstrative experiment using a naphthalocyanine-doped polymer film is described, proving that the temporal aberration free recompression of ultrashort light pulses is feasible, therefore opening a way for applications in ultrashort light pulse shaping. Aspects for a comparison between cw hole-burning

  17. Effects of the Distributions of Energy or Charge Transfer Rates on Spectral Hole Burning in Pigment-Protein Complexes at Low Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Herascu, N.; Ahmouda, S.; Picorel, R.; Seibert, M.; Jankowiak, R.; Zazubovich, V.

    2011-12-22

    Effects of the distributions of excitation energy transfer (EET) rates (homogeneous line widths) on the nonphotochemical (resonant) spectral hole burning (SHB) processes in photosynthetic chlorophyll-protein complexes (reaction center [RC] and CP43 antenna of Photosystem II from spinach) are considered. It is demonstrated that inclusion of such a distribution results in somewhat more dispersive hole burning kinetics. More importantly, however, inclusion of the EET rate distributions strongly affects the dependence of the hole width on the fractional hole depth. Different types of line width distributions have been explored, including those resulting from Foerster type EET between weakly interacting pigments as well as Gaussian ones, which may be a reasonable approximation for those resulting, for instance, from so-called extended Foerster models. For Gaussian line width distributions, it is possible to determine the parameters of both line width and tunneling parameter distributions from SHB data without a priori knowledge of any of them. Concerning more realistic asymmetric distributions, we demonstrate, using the simple example of CP43 antenna, that one can use SHB modeling to estimate electrostatic couplings between pigments and support or exclude assignment of certain pigment(s) to a particular state.

  18. Power budget analysis of image-plane storage in spectral hole-burning materials

    International Nuclear Information System (INIS)

    Neifeld, M.A.; Randall Babbitt, W.; Krishna Mohan, R.; Craig, A.E.

    2004-01-01

    We analyze the power requirements of a volumetric storage system based on hole-burning materials. We consider an image-plane architecture that uses ultra-fine wavelength addressing. We perform an optimization study in which hole-depth, material thickness, and spot size are selected to minimize the system power budget. We find that a data rate of 10 Gbps and a latency of 10 μs can be achieved in a read-once system based on Eu-YSO with a total power budget of only 23 mW. The same material system designed to tolerate 1000 read cycles would require only a factor of 15 increase in power

  19. Ninth international conference on hole burning, single molecule and related spectroscopies: science and applications (HBSM 2006)

    International Nuclear Information System (INIS)

    2006-01-01

    This conference was organized around 9 sessions: -) single molecule, -) quantum optics, -) hole-burning materials and mechanisms, -) single nano-particle spectroscopy, -) dephasing and spectral diffusion, -) microwave photonics, -) biological systems, -) rare earth doped materials, -) novel laser sources. This document gathers only the slides of the presentations

  20. Ninth international conference on hole burning, single molecule and related spectroscopies: science and applications (HBSM 2006)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    This conference was organized around 9 sessions: -) single molecule, -) quantum optics, -) hole-burning materials and mechanisms, -) single nano-particle spectroscopy, -) dephasing and spectral diffusion, -) microwave photonics, -) biological systems, -) rare earth doped materials, -) novel laser sources. This document gathers only the slides of the presentations.

  1. Dispersive heterodyne probing method for laser frequency stabilization based on spectral hole burning in rare-earth doped crystals

    DEFF Research Database (Denmark)

    Gobron, Olivier; Jung, K.; Galland, N.

    2017-01-01

    Frequency-locking a laser to a spectral hole in rare-earth doped crystals at cryogenic temperature has been shown to be a promising alternative to the use of high finesse Fabry-Perot cavities when seeking a very high short term stability laser (M. J. Thorpe et al., Nature Photonics 5, 688 (2011......)). We demonstrate here a novel technique for achieving such stabilization, based on generating a heterodyne beat-note between a master laser and a slave laser whose dephasing caused by propagation near a spectral hole generate the error signal of the frequency lock. The master laser is far detuned from...

  2. Optical Hole Burning of Materials for Frequency Domain Optical Storage and Processing

    National Research Council Canada - National Science Library

    Gorokhovsky, Anshel

    2002-01-01

    .... Hole burning parameters were determined for eight materials; in particular, the hole burning kinetics was analyzed and the quantum efficiencies were determined to be between 0.1% and 1%. Holograms (data pages...

  3. Persistent hole-burning of perylene microcrystallites dispersed in PVA

    International Nuclear Information System (INIS)

    Mizuno, K.; Matsubara, T.; Sugahara, K.; Aoki-Matsumoto, T.; Ichida, M.; Ando, H.; Itoh, T.

    2011-01-01

    A persistent hole-burning is observed in β-perylene microcrystallites, which were embedded in poly-vinyl alcohol. By laser light excitation at 22,535 cm -1 and at 10 K, the hole is found at the excitation photon energy. The mechanism of the persistent hole-burning is interpreted in terms of the resolution of microcrystallites into smaller microcrystallites. This is a novel observation of the persistent hole-burning in aromatic microcrystallites. When the specimen, which includes a hole, is annealed at high temperatures, the resolved microcrystallites restore back to the old position as had been. The β-perylene microcrystallite specimen that we have grown was as small as 1.5 nm in average diameter. They are one order smaller in number of molecules included, compared to those that have been reported on aromatic microcrystallites, anthracene for example. Due to this, we were able to observe the 0-0 transition energy, which varied according as the number of molecules involved in the microcrystallites. We also observed the 0-0 absorption (excitation) spectrum, which depends on the molecular arrays in the microcrystallites. The 0-0 transition of a single molecule in poly-vinyl alcohol matrix is anticipated to be located at 22,885 cm -1 .

  4. [Analysis of sensitive spectral bands for burning status detection using hyper-spectral images of Tiangong-01].

    Science.gov (United States)

    Qin, Xian-Lin; Zhu, Xi; Yang, Fei; Zhao, Kai-Rui; Pang, Yong; Li, Zeng-Yuan; Li, Xu-Zhi; Zhang, Jiu-Xing

    2013-07-01

    To obtain the sensitive spectral bands for detection of information on 4 kinds of burning status, i. e. flaming, smoldering, smoke, and fire scar, with satellite data, analysis was conducted to identify suitable satellite spectral bands for detection of information on these 4 kinds of burning status by using hyper-spectrum images of Tiangong-01 (TG-01) and employing a method combining statistics and spectral analysis. The results show that: in the hyper-spectral images of TG-01, the spectral bands differ obviously for detection of these 4 kinds of burning status; in all hyper-spectral short-wave infrared channels, the reflectance of flaming is higher than that of all other 3 kinds of burning status, and the reflectance of smoke is the lowest; the reflectance of smoke is higher than that of all other 3 kinds of burning status in the channels corresponding to hyper-spectral visible near-infrared and panchromatic sensors. For spectral band selection, more suitable spectral bands for flaming detection are 1 000.0-1 956.0 and 2 020.0-2 400.0 nm; the suitable spectral bands for identifying smoldering are 930.0-1 000.0 and 1 084.0-2 400.0 nm; the suitable spectral bands for smoke detection is in 400.0-920.0 nm; for fire scar detection, it is suitable to select bands with central wavelengths of 900.0-930.0 and 1 300.0-2 400.0 nm, and then to combine them to construct a detection model.

  5. Evaluation of burned aspen communities in Jackson Hole, Wyoming

    Science.gov (United States)

    Charles E. Kay

    2001-01-01

    Aspen has been declining in Jackson Hole for many years, a condition generally attributed to the fact that lightning fires have been aggressively suppressed since the early 1900s. It is also believed that burning will successfully regenerate aspen stands despite high elk numbers. To test this hypothesis, I evaluated 467 burned and 495 adjacent, unburned aspen stands at...

  6. Axial profiles of burned and fraction of holes for calculations of criticality with credit for BWR fuel burning

    International Nuclear Information System (INIS)

    Casado Sanchez, C.; Rubio Oviedo, P.

    2014-01-01

    This paper presents a method to define surround profiles of burning and fraction of holes suited for use in applications of credit to burning of BWR fuel from results obtained with the module STARBUCS of SCALE. (Author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Matsuzaki, Satoshi [Iowa State Univ., Ames, IA (United States)

    2001-01-01

    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 bacteriochlorophylla (BChla) 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.

  8. Nonphotochemical Hole-Burning Imaging Studies of in vitro Carcinoma and Normal Cells Utilizing a Mitochondrial Specific Dye

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Richard Joseph [Iowa State Univ., Ames, IA (United States)

    2002-01-01

    Low temperature Nonphotochemical Hole Burning (NPHB) Spectroscopy of the dye rhodamine 800 (MF680) was applied for the purpose of discerning differences between cultured normal and carcinoma ovarian surface epithelial (OSE) cells. Both the cell lines were developed and characterized at the Mayo Clinic (Rochester, MN), with the normal cell line having been transfected with a strain of temperature sensitive Simian Virus 40 Large T Antigen (SV40) for the purpose of extending the life of the cell culture without inducing permanent changes in the characteristics of the cell line. The cationic lipophilic fluorophore rhodamine 800 preferentially locates in in situ mitochondria due to the high lipid composition of mitochondria and the generation of a large negative membrane potential (relative to the cellular cytoplasm) for oxidative phosphorylation. Results presented for NPHB of MF680 located in the cells show significant differences between the two cell lines. The results are interpreted on the basis of the NPHB mechanism and characteristic interactions between the host (cellular mitochondrial) and the guest (MF680) in the burning of spectral holes, thus providing an image of the cellular ultrastructure. Hole growth kinetics (HGK) were found to differ markedly between the two cell lines, with the carcinoma cell line burning at a faster average rate for the same exposure fluence. Theoretical fits to the data suggest a lower degree of structural heterogeneity in the carcinoma cell line relative to the normal cell line. Measurement of changes in the permanent dipole moment (fΔμ) were accomplished by measurement of changes in hole width in response to the application of an external electric field (the Stark effect), and found that Δμ values for the carcinoma line were 1.5x greater than those of the SV40 antigen-free normal analogs. These findings are interpreted in terms of effects from the mitochondrial membrane potential. Results for HGK on the scale of single cells is

  9. Nonphotochemical Hole-Burning Imaging Studies of In Vitro Carcinoma and Normal Cells Utilizing a Mitochondrial Specific Dye

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Richard Joseph [Iowa State Univ., Ames, IA (United States)

    2002-01-01

    Low temperature Nonphotochemical Hole Burning (NPHB) Spectroscopy of the dye rhodamine 800 (MF680) was applied for the purpose of discerning differences between cultured normal and carcinoma ovarian surface epithelial (OSE) cells. Both the cell lines were developed and characterized at the Mayo Clinic (Rochester, MN), with the normal cell line having been transfected with a strain of temperature sensitive Simian Virus 40 Large T Antigen (SV40) for the purpose of extending the life of the cell culture without inducing permanent changes in the characteristics of the cell line. The cationic lipophilic fluorophore rhodamine 800 preferentially locates in in situ mitochondria due to the high lipid composition of mitochondria and the generation of a large negative membrane potential (relative to the cellular cytoplasm) for oxidative phosphorylation. Results presented for NPHB of MF680 located in the cells show significant differences between the two cell lines. The results are interpreted on the basis of the NPHB mechanism and characteristic interactions between the host (cellular mitochondrial) and the guest (MF680) in the burning of spectral holes, thus providing an image of the cellular ultrastructure. Hole growth kinetics (HGK) were found to differ markedly between the two cell lines, with the carcinoma cell line burning at a faster average rate for the same exposure fluence. Theoretical fits to the data suggest a lower degree of structural heterogeneity in the carcinoma cell line relative to the normal cell line. Measurement of changes in the permanent dipole moment (fΔμ)were accomplished by measurement of changes in hole width in response to the application of an external electric field (the Stark effect), and found that Δμ values for the carcinoma line were 1.5x greater than those of the SV40 antigen-free normal analogs. These findings are interpreted in terms of effects from the mitochondrial membrane potential. Results for HGK on the scale of single cells is

  10. Low-temperature protein dynamics of the B800 molecules in the LH2 light-harvesting complex: spectral hole burning study and comparison with single photosynthetic complex spectroscopy.

    Science.gov (United States)

    Grozdanov, Daniel; Herascu, Nicoleta; Reinot, Tõnu; Jankowiak, Ryszard; Zazubovich, Valter

    2010-03-18

    Previously published and new spectral hole burning (SHB) data on the B800 band of LH2 light-harvesting antenna complex of Rps. acidophila are analyzed in light of recent single photosynthetic complex spectroscopy (SPCS) results (for a review, see Berlin et al. Phys. Life Rev. 2007, 4, 64.). It is demonstrated that, in general, SHB-related phenomena observed for the B800 band are in qualitative agreement with the SPCS data and the protein models involving multiwell multitier protein energy landscapes. Regarding the quantitative agreement, we argue that the single-molecule behavior associated with the fastest spectral diffusion (smallest barrier) tier of the protein energy landscape is inconsistent with the SHB data. The latter discrepancy can be attributed to SPCS probing not only the dynamics of of the protein complex per se, but also that of the surrounding amorphous host and/or of the host-protein interface. It is argued that SHB (once improved models are developed) should also be able to provide the average magnitudes and probability distributions of light-induced spectral shifts and could be used to determine whether SPCS probes a set of protein complexes that are both intact and statistically relevant. SHB results are consistent with the B800 --> B850 energy-transfer models including consideration of the whole B850 density of states.

  11. A Black Hole Spectral Signature

    Science.gov (United States)

    Titarchuk, Lev; Laurent, Philippe

    2000-03-01

    An accreting black hole is, by definition, characterized by the drain. Namely, the matter falls into a black hole much the same way as water disappears down a drain matter goes in and nothing comes out. As this can only happen in a black hole, it provides a way to see ``a black hole'', an unique observational signature. The accretion proceeds almost in a free-fall manner close to the black hole horizon, where the strong gravitational field dominates the pressure forces. In this paper we present analytical calculations and Monte-Carlo simulations of the specific features of X-ray spectra formed as a result of upscattering of the soft (disk) photons in the converging inflow (CI) into the black hole. The full relativistic treatment has been implemented to reproduce these spectra. We show that spectra in the soft state of black hole systems (BHS) can be described as the sum of a thermal (disk) component and the convolution of some fraction of this component with the CI upscattering spread (Greens) function. The latter boosted photon component is seen as an extended power-law at energies much higher than the characteristic energy of the soft photons. We demonstrate the stability of the power spectral index over a wide range of the plasma temperature 0 - 10 keV and mass accretion rates (higher than 2 in Eddington units). We also demonstrate that the sharp high energy cutoff occurs at energies of 200-400 keV which are related to the average energy of electrons mec2 impinging upon the event horizon. The spectrum is practically identical to the standard thermal Comptonization spectrum when the CI plasma temperature is getting of order of 50 keV (the typical ones for the hard state of BHS). In this case one can see the effect of the bulk motion only at high energies where there is an excess in the CI spectrum with respect to the pure thermal one. Furthermore we demonstrate that the change of spectral shapes from the soft X-ray state to the hard X-ray state is clearly to be

  12. Hole spectral functions in lightly doped quantum antiferromagnets

    Science.gov (United States)

    Kar, Satyaki; Manousakis, Efstratios

    2011-11-01

    We study the hole and magnon spectral functions as a function of hole doping in the two-dimensional t-J and t-t'-t''-J models working within the limits of spin-wave theory by linearizing the hole-spin-deviation interaction and by adapting the noncrossing approximation. We find that the staggered magnetization decreases rather rapidly with doping and it goes to zero at a few percent of hole concentration in both t-J and t-t'-t''-J models. Furthermore, our results show that the residue of the quasiparticle peak at G⃗=(±π/2,±π/2) decreases very rapidly with doping. We also find pockets centered at G⃗, (i) with an elliptical shape with large eccentricity along the antinodal direction in the case of the t-J model and (ii) with an almost circular shape in the case of the t-t'-t''-J model. Last, we show that the spectral intensity distribution in the doped antiferromagnet has a waterfall-like pattern along the nodal direction of the Brillouin zone, a feature that is also seen in angle-resolved photoemission spectroscopy measurements.

  13. Excitation of photonic atoms (dielectric microspheres) on optical fibers: application to room-temperature persistent spectral hole burning

    Science.gov (United States)

    Serpenguzel, Ali; Arnold, Stephen; Griffel, Giora

    1995-05-01

    Recently, photonic atoms (dielectric microspheres) have enjoyed the attention of the optical spectroscopy community. A variety of linear and nonlinear optical processes have been observed in liquid microdroplets. But solid state photonic devices using these properties are scarce. A first of these applications is the room temperature microparticle hole-burning memory. New applications can be envisioned if microparticle resonances can be coupled to traveling waves in optical fibers. In this paper we demonstrate the excitation of narrow morphology dependent resonances of microparticles placed on an optical fiber. Furthermore we reveal a model for this process which describes the coupling efficiency in terms of the geometrical and material properties of the microparticle-fiber system.

  14. Femtosecond nonlinear spectroscopy at surfaces: Second-harmonic probing of hole burning at the Si(111)7x7 surface and Fourier-transform sum-frequency vibrational spectroscopy

    International Nuclear Information System (INIS)

    McGuire, John Andrew

    2004-01-01

    The high temporal resolution and broad bandwidth of a femtosecond laser system are exploited in a pair of nonlinear optical studies of surfaces. The dephasing dynamics of resonances associated with the adatom dangling bonds of the Si(111)7 x 7 surface are explored by transient second-harmonic hole burning, a process that can be described as a fourth-order nonlinear optical process. Spectral holes produced by a 100 fs pump pulse at about 800 nm are probed by the second harmonic signal of a 100 fs pulse tunable around 800 nm. The measured spectral holes yield homogeneous dephasing times of a few tens of femtoseconds. Fits with a Lorentzian spectral hole centered at zero probe detuning show a linear dependence of the hole width on pump fluence, which suggests that charge carrier-carrier scattering dominates the dephasing dynamics at the measured excitation densities. Extrapolation of the deduced homogeneous dephasing times to zero excitation density yields an intrinsic dephasing time of ∼ 70 fs. The presence of a secondary spectral hole indicates that scattering of the surface electrons with surface optical phonons at 570 cm -1 occurs within the first 200 fs after excitation. The broad bandwidth of femtosecond IR pulses is used to perform IR-visible sum frequency vibrational spectroscopy. By implementing a Fourier-transform technique, we demonstrate the ability to obtain sub-laser-bandwidth spectral resolution. FT-SFG yields a greater signal when implemented with a stretched visible pulse than with a femtosecond visible pulse. However, when compared with multichannel spectroscopy using a femtosecond IR pulse but a narrowband visible pulse, Fourier-transform SFG is found to have an inferior signal-to-noise ratio. A mathematical analysis of the signal-to-noise ratio illustrates the constraints on the Fourier-transform approach

  15. Femtosecond nonlinear spectroscopy at surfaces: Second-harmonic probing of hole burning at the Si(111)7x7 surface and fourier-transform sum-frequency vibrational spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    McGuire, John Andrew [Univ. of California, Berkeley, CA (United States)

    2004-11-24

    The high temporal resolution and broad bandwidth of a femtosecond laser system are exploited in a pair of nonlinear optical studies of surfaces. The dephasing dynamics of resonances associated with the adatom dangling bonds of the Si(111)7 x 7 surface are explored by transient second-harmonic hole burning, a process that can be described as a fourth-order nonlinear optical process. Spectral holes produced by a 100 fs pump pulse at about 800 nm are probed by the second harmonic signal of a 100 fs pulse tunable around 800 nm. The measured spectral holes yield homogeneous dephasing times of a few tens of femtoseconds. Fits with a Lorentzian spectral hole centered at zero probe detuning show a linear dependence of the hole width on pump fluence, which suggests that charge carrier-carrier scattering dominates the dephasing dynamics at the measured excitation densities. Extrapolation of the deduced homogeneous dephasing times to zero excitation density yields an intrinsic dephasing time of {approx} 70 fs. The presence of a secondary spectral hole indicates that scattering of the surface electrons with surface optical phonons at 570 cm-1 occurs within the first 200 fs after excitation. The broad bandwidth of femtosecond IR pulses is used to perform IR-visible sum frequency vibrational spectroscopy. By implementing a Fourier-transform technique, we demonstrate the ability to obtain sub-laser-bandwidth spectral resolution. FT-SFG yields a greater signal when implemented with a stretched visible pulse than with a femtosecond visible pulse. However, when compared with multichannel spectroscopy using a femtosecond IR pulse but a narrowband visible pulse, Fourier-transform SFG is found to have an inferior signal-to-noise ratio. A mathematical analysis of the signal-to-noise ratio illustrates the constraints on the Fourier-transform approach.

  16. Separability Analysis of Sentinel-2A Multi-Spectral Instrument (MSI Data for Burned Area Discrimination

    Directory of Open Access Journals (Sweden)

    Haiyan Huang

    2016-10-01

    Full Text Available Biomass burning is a global phenomenon and systematic burned area mapping is of increasing importance for science and applications. With high spatial resolution and novelty in band design, the recently launched Sentinel-2A satellite provides a new opportunity for moderate spatial resolution burned area mapping. This study examines the performance of the Sentinel-2A Multi Spectral Instrument (MSI bands and derived spectral indices to differentiate between unburned and burned areas. For this purpose, five pairs of pre-fire and post-fire top of atmosphere (TOA reflectance and atmospherically corrected (surface reflectance images were studied. The pixel values of locations that were unburned in the first image and burned in the second image, as well as the values of locations that were unburned in both images which served as a control, were compared and the discrimination of individual bands and spectral indices were evaluated using parametric (transformed divergence and non-parametric (decision tree approaches. Based on the results, the most suitable MSI bands to detect burned areas are the 20 m near-infrared, short wave infrared and red-edge bands, while the performance of the spectral indices varied with location. The atmospheric correction only significantly influenced the separability of the visible wavelength bands. The results provide insights that are useful for developing Sentinel-2 burned area mapping algorithms.

  17. Spectral-Domain Measurement of Strain Sensitivity of a Two-Mode Birefringent Side-Hole Fiber

    Directory of Open Access Journals (Sweden)

    Waclaw Urbanczyk

    2012-09-01

    Full Text Available The strain sensitivity of a two-mode birefringent side-hole fiber is measured in the spectral domain. In a simple experimental setup comprising a broadband source, a polarizer, a two-mode birefringent side-hole fiber under varied elongations, an analyzer and a compact spectrometer, the spectral interferograms are resolved. These are characterized by the equalization wavelength at which spectral interference fringes have the highest visibility (the largest period due to the zero group optical path difference between the fundamental, the LP01 mode and the higher-order, the LP11 mode. The spectral interferograms with the equalization wavelength are processed to retrieve the phase as a function of the wavelength. From the retrieved phase functions corresponding to different elongations of a two-mode birefringent side-hole fiber under test, the spectral strain sensitivity is obtained. Using this approach, the intermodal spectral strain sensitivity was measured for both x and y polarizations. Moreover, the spectral polarimetric sensitivity to strain was measured for the fundamental mode when a birefringent delay line was used in tandem with the fiber. Its spectral dependence was also compared with that obtained from a shift of the spectral interferograms not including the equalization wavelength, and good agreement was confirmed.

  18. Spectrally narrow, long-term stable optical frequency reference based on a Eu3+:Y2SiO5 crystal at cryogenic temperature.

    Science.gov (United States)

    Chen, Qun-Feng; Troshyn, Andrei; Ernsting, Ingo; Kayser, Steffen; Vasilyev, Sergey; Nevsky, Alexander; Schiller, Stephan

    2011-11-25

    Using an ultrastable continuous-wave laser at 580 nm we performed spectral hole burning of Eu(3+):Y(2)SiO(5) at a very high spectral resolution. The essential parameters determining the usefulness as a macroscopic frequency reference, linewidth, temperature sensitivity, and long-term stability, were characterized using a H-maser stabilized frequency comb. Spectral holes with a linewidth as low as 6 kHz were observed and the upper limit of the drift of the hole frequency was determined to be 5±3 mHz/s. We discuss the necessary requirements for achieving ultrahigh stability in laser frequency stabilization to these spectral holes.

  19. Ultrafast signal processing in quantum dot amplifiers through effective spectral holeburning

    DEFF Research Database (Denmark)

    Berg, Tommy Winther; Mørk, Jesper; Uskov, A. V.

    2002-01-01

    suitable for ultrafast signal processing. The basis of this property is that the process of spectral hole burning (SHB) can become very effective. We consider a traveling wave optical amplifier consisting of the dot states, which interact with the optical signal (no inhomogeneous broadening included...

  20. A Global Spectral Study of Stellar-Mass Black Holes with Unprecedented Sensitivity

    Science.gov (United States)

    Garci, Javier

    There are two well established populations of black holes: (i) stellar-mass black holes with masses in the range 5 to 30 solar masses, many millions of which are present in each galaxy in the universe, and (ii) supermassive black holes with masses in the range millions to billions of solar masses, which reside in the nucleus of most galaxies. Supermassive black holes play a leading role in shaping galaxies and are central to cosmology. However, they are hard to study because they are dim and they scarcely vary on a human timescale. Luckily, their variability and full range of behavior can be very effectively studied by observing their stellar-mass cousins, which display in miniature the full repertoire of a black hole over the course of a single year. The archive of data collected by NASA's Rossi X-ray Timing Explorer (RXTE) during its 16 year mission is of first importance for the study of stellar-mass black holes. While our ultimate goal is a complete spectral analysis of all the stellar-mass black hole data in the RXTE archive, the goal of this proposal is the global study of six of these black holes. The two key methodologies we bring to the study are: (1) Our recently developed calibration tool that increases the sensitivity of RXTE's detector by up to an order of magnitude; and (2) the leading X-ray spectral "reflection" models that are arguably the most effective means currently available for probing the effects of strong gravity near the event horizon of a black hole. For each of the six black holes, we will fit our models to all the archived spectral data and determine several key parameters describing the black hole and the 10-million-degree gas that surrounds it. Of special interest will be our measurement of the spin (or rate of rotation) of each black hole, which can be as high as tens of thousands of RPM. Profoundly, all the properties of an astronomical black hole are completely defined by specifying its spin and its mass. The main goal of this

  1. WIDEFIELD SPECTRAL-DOMAIN OPTICAL COHERENCE TOMOGRAPHY IMAGING OF PERIPHERAL ROUND RETINAL HOLES WITH OR WITHOUT RETINAL DETACHMENT.

    Science.gov (United States)

    Casswell, Edward J; Abou Ltaif, Sleiman; Carr, Thomas; Keane, Pearse A; Charteris, David G; Wickham, Louisa

    2018-03-02

    To describe the widefield spectral-domain optical coherence tomography features of peripheral round retinal holes, with or without associated retinal detachment (RD). Retrospective, observational study of 28 eyes with peripheral round retinal holes, with and without RD. Patients underwent imaging with a widefield 50-degree spectral-domain optical coherence tomography (Heidelberg Engineering, Germany) and Optos ultra-widefield imaging systems (Optos, United Kingdom). Vitreous attachment at the site of the retinal hole was detected in 27/28 (96.4%) cases. Cases were split into three groups: RHs with RD (n = 12); RHs with subretinal fluid (n = 5), and flat RHs (n = 11), with minimal or no subretinal fluid. 91.6% retinal holes associated with subretinal fluid or RD had vitreous attachment at the site of the hole. Eighty percent had vitreous attachment at both edges of the retinal hole, in a U-shape configuration, which appeared to exert traction. By contrast, flat retinal holes had visible vitreous attachment only at one edge of the retinal hole in 45.4%. Vitreous attachment was commonly seen at the site of round retinal holes. Vitreous attachment at both edges of the retinal hole in a U-shape configuration was more commonly seen at holes associated with subretinal fluid or RD.

  2. Spectral and Timing States in Black Hole Binaries

    Science.gov (United States)

    Wilms, J.

    Results on the long term variability of galactic black hole candidates are reviewed. I mainly present the results of a > 2 year long campaign with RXTE to monitor the canonical soft state black hole candidates LMC X-1 and LMC X-3 using monthly observations. These observations are presented within the context of the RXTE-ASM long term quasi-periodic variability on timescales of about 150d. For LMC X-3, times of low ASM count rate are correlated with a significant hardening of the X-ray spectrum. The observation with the lowest flux during the whole monitoring campaign can be modeled with a simple γ=1.7 power law -- a hard state spectrum. Since these spectral hardenings occur on the 150 d timescale it is probable that they are associated with periodic changes in the accretion rate. Possible causes for this behavior are discussed, e.g. a wind driven limit-cycle or long-term variability of the donor star.

  3. Analysis of Cross-Seasonal Spectral Response from Kettle Holes: Application of Remote Sensing Techniques for Chlorophyll Estimation

    Directory of Open Access Journals (Sweden)

    Bernd Lennartz

    2012-11-01

    Full Text Available Kettle holes, small inland water bodies usually less than 1 ha in size, are subjected to pollution, drainage, and structural alteration by intensive land use practices. This study presents the analysis of spectral signatures from kettle holes based on in situ water sampling and reflectance measurements in application for chlorophyll estimation. Water samples and surface reflectance from kettle holes were collected from 6 ponds in 15 field campaigns (5 in 2007 and 10 in 2008, resulting in a total of 80 spectral datasets. We assessed the existing semi-empirical algorithms to determine chlorophyll content for different types of kettle holes using seasonal and cross-seasonal volume reflectance and derivative spectra. Based on this analysis and optical properties of water leaving reflectance from kettle holes, the following typology of the remote signal interpretation was proposed: Submerged vegetation, Phytoplankton dominated and Mixed type.

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

    International Nuclear Information System (INIS)

    Satoshi Matsuzaki

    2002-01-01

    Burn wavelength (λ B )-dependent nonphotochemical hole spectra are reported for the lowest energy Q y -absorption band of the Fenna-Matthews-Olson (FMO) trimer complex from Prosthecochloris aestuarii. This band at 825 nm is contributed to by three states that stem from the lowest energy state of the subunit of the trimer. The spectra reveal unusually rich and quite sharp low energy satellite structure that consists of holes at 18, 24, 36, 48, 72, 120 and 165 cm -1 as measured relative to the resonant hole at λ B . The possibility that some of these holes are due to correlated downward energy transfer from the two higher energy states that contribute to the 825 nm band could be rejected. Thus, the FMO complex is yet another example of a photosynthetic complex for which structural heterogeneity results in distributions for the values of the energy gaps between Q y -states. The results of theoretical simulations of the hole spectra are consistent with the above holes being due to intermolecular phonons and low energy intramolecular vibrations of the bacteriochlorophyll a (BChl a) molecule. The 36 cm -1 and higher energy modes are most likely due to the intramolecular BChl a modes. The simulations lead to the determination of the Huang-Rhys (S) factor for all modes

  5. Hole Burning Imaging Studies of Cancerous and Analogous Normal Ovarian Tissues Utilizing Organelle Specific Dyes

    Energy Technology Data Exchange (ETDEWEB)

    Matsuzaki, Satoshi [Iowa State Univ., Ames, IA (United States)

    2004-01-01

    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 σΛ, as well as the standard hole burning parameters (namely, γ 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 (fΔμ) for MF680 in tissue samples when burn laser polarization is parallel to the Stark field. Differences are detected between fΔμs 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

  6. Object-based assessment of burn severity in diseased forests using high-spatial and high-spectral resolution MASTER airborne imagery

    Science.gov (United States)

    Chen, Gang; Metz, Margaret R.; Rizzo, David M.; Dillon, Whalen W.; Meentemeyer, Ross K.

    2015-04-01

    Forest ecosystems are subject to a variety of disturbances with increasing intensities and frequencies, which may permanently change the trajectories of forest recovery and disrupt the ecosystem services provided by trees. Fire and invasive species, especially exotic disease-causing pathogens and insects, are examples of disturbances that together could pose major threats to forest health. This study examines the impacts of fire and exotic disease (sudden oak death) on forests, with an emphasis on the assessment of post-fire burn severity in a forest where trees have experienced three stages of disease progression pre-fire: early-stage (trees retaining dried foliage and fine twigs), middle-stage (trees losing fine crown fuels), and late-stage (trees falling down). The research was conducted by applying Geographic Object-Based Image Analysis (GEOBIA) to MASTER airborne images that were acquired immediately following the fire for rapid assessment and contained both high-spatial (4 m) and high-spectral (50 bands) resolutions. Although GEOBIA has gradually become a standard tool for analyzing high-spatial resolution imagery, high-spectral resolution data (dozens to hundreds of bands) can dramatically reduce computation efficiency in the process of segmentation and object-based variable extraction, leading to complicated variable selection for succeeding modeling. Hence, we also assessed two widely used band reduction algorithms, PCA (principal component analysis) and MNF (minimum noise fraction), for the delineation of image objects and the subsequent performance of burn severity models using either PCA or MNF derived variables. To increase computation efficiency, only the top 5 PCA and MNF and top 10 PCA and MNF components were evaluated, which accounted for 10% and 20% of the total number of the original 50 spectral bands, respectively. Results show that if no band reduction was applied the models developed for the three stages of disease progression had relatively

  7. Hole burning with pressure and electric field: A window on the electronic structure and energy transfer dynamics of bacterial antenna complexes

    Energy Technology Data Exchange (ETDEWEB)

    Wu, H.M.

    1999-02-12

    Light-harvesting (LH) complexes of cyclic (C{sub n}) symmetry from photosynthetic bacteria are studied using absorption and high pressure- and Stark-hole burning spectroscopies. The B800 absorption band of LH2 is inhomogeneously broadened while the B850 band of LH2 and the B875 band of the LH1 complex exhibit significant homogeneous broadening due to ultra-fast inter-exciton level relaxation. The B800{r_arrow}B850 energy transfer rate of ({approximately}2 ps){sup {minus}1} as determined by hole burning and femtosecond pump-probe spectroscopies, is weakly dependent on pressure and temperature, both of which significantly affect the B800-B850 energy gap. The resilience is theoretically explained in terms of a modified Foerster theory with the spectral overlap provided by the B800 fluorescence origin band and weak vibronic absorption bands of B850. Possible explanations for the additional sub-picosecond relaxation channel of B800 observed with excitation on the blue side of B800 are given. Data from pressure and temperature dependent studies show that the B800 and B850 bacteriochlorophyll a (BChl a) molecules are weakly and strongly excitonically coupled, respectively, which is consistent with the X-ray structure of LH2. The B875 BChl a molecules are also strongly coupled. It is concluded that electron-exchange, in addition to electrostatic interactions, is important for understanding the strong coupling of the B850 and B875 rings. The large linear pressure shifts of {approximately}{minus}0.6 cm{sup {minus}1}/MPa associated with B850 and B875 can serve as important benchmarks for electronic structure calculations.

  8. Detecting post-fire burn severity and vegetation recovery using multitemporal remote sensing spectral indices and field-collected composite burn index data in a ponderosa pine forest

    Science.gov (United States)

    Chen, Xuexia; Vogelmann, James E.; Rollins, Matt; Ohlen, Donald; Key, Carl H.; Yang, Limin; Huang, Chengquan; Shi, Hua

    2011-01-01

    It is challenging to detect burn severity and vegetation recovery because of the relatively long time period required to capture the ecosystem characteristics. Multitemporal remote sensing data can providemultitemporal observations before, during and after a wildfire, and can improve the change detection accuracy. The goal of this study is to examine the correlations between multitemporal spectral indices and field-observed burn severity, and to provide a practical method to estimate burn severity and vegetation recovery. The study site is the Jasper Fire area in the Black Hills National Forest, South Dakota, that burned during August and September 2000. Six multitemporal Landsat images acquired from 2000 (pre-fire), 2001 (post-fire), 2002, 2003, 2005 and 2007 were used to assess burn severity. The normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), normalized burn ratio (NBR), integrated forest index (IFI) and the differences of these indices between the pre-fire and post-fire years were computed and analysed with 66 field-based composite burn index (CBI) plots collected in 2002. Results showed that differences of NDVI and differences of EVI between the pre-fire year and the first two years post-fire were highly correlated with the CBI scores. The correlations were low beyond the second year post-fire. Differences of NBR had good correlation with CBI scores in all study years. Differences of IFI had low correlation with CBI in the first year post-fire and had good correlation in later years. A CBI map of the burnt area was produced using regression tree models and the multitemporal images. The dynamics of four spectral indices from 2000 to 2007 indicated that both NBR and IFI are valuable for monitoring long-term vegetation recovery. The high burn severity areas had a much slower recovery than the moderate and low burn areas.

  9. Spectral Mixture Analysis to map burned areas in Brazil's deforestation arc from 1992 to 2011

    Science.gov (United States)

    Antunes Daldegan, G.; Ribeiro, F.; Roberts, D. A.

    2017-12-01

    The two most extensive biomes in South America, the Amazon and the Cerrado, are subject to several fire events every dry season. Both are known for their ecological and environmental importance. However, due to the intensive human occupation over the last four decades, they have been facing high deforestation rates. The Cerrado biome is adapted to fire and is considered a fire-dependent landscape. In contrast, the Amazon as a tropical moist broadleaf forest does not display similar characteristics and is classified as a fire-sensitive landscape. Nonetheless, studies have shown that forest areas that have already been burned become more prone to experience recurrent burns. Remote sensing has been extensively used by a large number of researchers studying fire occurrence at a global scale, as well as in both landscapes aforementioned. Digital image processing aiming to map fire activity has been applied to a number of imagery from sensors of various spatial, temporal, and spectral resolutions. More specifically, several studies have used Landsat data to map fire scars in the Amazon forest and in the Cerrado. An advantage of using Landsat data is the potential to map fire scars at a finer spatial resolution, when compared to products derived from imagery of sensors featuring better temporal resolution but coarser spatial resolution, such as MODIS (Moderate Resolution Imaging Spectrometer) and GOES (Geostationary Operational Environmental Satellite). This study aimed to map burned areas present in the Amazon-Cerrado transition zone by applying Spectral Mixture Analysis on Landsat imagery for a period of 20 years (1992-2011). The study area is a subset of this ecotone, centered at the State of Mato Grosso. By taking advantage of the Landsat 5TM and Landsat 7ETM+ imagery collections available in Google Earth Engine platform and applying Spectral Mixture Analysis (SMA) techniques over them permitted to model fire scar fractions and delimitate burned areas. Overlaying

  10. Excitation energy transfer in natural photosynthetic complexes and chlorophyll trefoils: hole-burning and single complex/trefoil spectroscopic studies

    Energy Technology Data Exchange (ETDEWEB)

    Ryszard Jankowiak, Kansas State University, Department of Chemistry, CBC Bldg., Manhattan KS, 66505; Phone: (785) 532-6785

    2012-09-12

    In this project we studied both natural photosynthetic antenna complexes and various artificial systems (e.g. chlorophyll (Chl) trefoils) using high resolution hole-burning (HB) spectroscopy and excitonic calculations. Results obtained provided more insight into the electronic (excitonic) structure, inhomogeneity, electron-phonon coupling strength, vibrational frequencies, and excitation energy (or electron) transfer (EET) processes in several antennas and reaction centers. For example, our recent work provided important constraints and parameters for more advanced excitonic calculations of CP43, CP47, and PSII core complexes. Improved theoretical description of HB spectra for various model systems offers new insight into the excitonic structure and composition of low-energy absorption traps in very several antenna protein complexes and reaction centers. We anticipate that better understanding of HB spectra obtained for various photosynthetic complexes and their simultaneous fits with other optical spectra (i.e. absorption, emission, and circular dichroism spectra) provides more insight into the underlying electronic structures of these important biological systems. Our recent progress provides a necessary framework for probing the electronic structure of these systems via Hole Burning Spectroscopy. For example, we have shown that the theoretical description of non-resonant holes is more restrictive (in terms of possible site energies) than those of absorption and emission spectra. We have demonstrated that simultaneous description of linear optical spectra along with HB spectra provides more realistic site energies. We have also developed new algorithms to describe both nonresonant and resonant hole-burn spectra using more advanced Redfield theory. Simultaneous description of various optical spectra for complex biological system, e.g. artificial antenna systems, FMO protein complexes, water soluble protein complexes, and various mutants of reaction centers

  11. Axial profiles of burned and fraction of holes for calculations of criticality with credit for BWR fuel burning; Perfiles axiales de quemado y fraccion de huecos para calculos de criticidad con credito al quemado para combustible BWR

    Energy Technology Data Exchange (ETDEWEB)

    Casado Sanchez, C.; Rubio Oviedo, P.

    2014-07-01

    This paper presents a method to define surround profiles of burning and fraction of holes suited for use in applications of credit to burning of BWR fuel from results obtained with the module STARBUCS of SCALE. (Author)

  12. Rare-earth doped transparent ceramics for spectral filtering and quantum information processing

    Science.gov (United States)

    Kunkel, Nathalie; Ferrier, Alban; Thiel, Charles W.; Ramírez, Mariola O.; Bausá, Luisa E.; Cone, Rufus L.; Ikesue, Akio; Goldner, Philippe

    2015-09-01

    Homogeneous linewidths below 10 kHz are reported for the first time in high-quality Eu3+ doped Y 2O3 transparent ceramics. This result is obtained on the 7F0→5D0 transition in Eu3+ doped Y 2O3 ceramics and corresponds to an improvement of nearly one order of magnitude compared to previously reported values in transparent ceramics. Furthermore, we observed spectral hole lifetimes of ˜15 min that are long enough to enable efficient optical pumping of the nuclear hyperfine levels. Additionally, different Eu3+ concentrations (up to 1.0%) were studied, resulting in an increase of up to a factor of three in the peak absorption coefficient. These results suggest that transparent ceramics can be useful in applications where narrow and deep spectral holes can be burned into highly absorbing lines, such as quantum information processing and spectral filtering.

  13. En face spectral domain optical coherence tomography analysis of lamellar macular holes.

    Science.gov (United States)

    Clamp, Michael F; Wilkes, Geoff; Leis, Laura S; McDonald, H Richard; Johnson, Robert N; Jumper, J Michael; Fu, Arthur D; Cunningham, Emmett T; Stewart, Paul J; Haug, Sara J; Lujan, Brandon J

    2014-07-01

    To analyze the anatomical characteristics of lamellar macular holes using cross-sectional and en face spectral domain optical coherence tomography. Forty-two lamellar macular holes were retrospectively identified for analysis. The location, cross-sectional length, and area of lamellar holes were measured using B-scans and en face imaging. The presence of photoreceptor inner segment/outer segment disruption and the presence or absence of epiretinal membrane formation were recorded. Forty-two lamellar macular holes were identified. Intraretinal splitting occurred within the outer plexiform layer in 97.6% of eyes. The area of intraretinal splitting in lamellar holes did not correlate with visual acuity. Eyes with inner segment/outer segment disruption had significantly worse mean logMAR visual acuity (0.363 ± 0.169; Snellen = 20/46) than in eyes without inner segment/outer segment disruption (0.203 ± 0.124; Snellen = 20/32) (analysis of variance, P = 0.004). Epiretinal membrane was present in 34 of 42 eyes (81.0%). En face imaging allowed for consistent detection and quantification of intraretinal splitting within the outer plexiform layer in patients with lamellar macular holes, supporting the notion that an area of anatomical weakness exists within Henle's fiber layer, presumably at the synaptic connection of these fibers within the outer plexiform layer. However, the en face area of intraretinal splitting did not correlate with visual acuity, disruption of the inner segment/outer segment junction was associated with significantly worse visual acuity in patients with lamellar macular holes.

  14. Rare-earth doped transparent ceramics for spectral filtering and quantum information processing

    Energy Technology Data Exchange (ETDEWEB)

    Kunkel, Nathalie, E-mail: nathalie.kunkel@chimie-paristech.fr; Goldner, Philippe, E-mail: philippe.goldner@chimie-paristech.fr [PSL Research University, Chimie ParisTech–CNRS, Institut de Recherche de Chimie Paris, 11 rue Pierre et Marie Curie, 75005 Paris (France); Ferrier, Alban [PSL Research University, Chimie ParisTech–CNRS, Institut de Recherche de Chimie Paris, 11 rue Pierre et Marie Curie, 75005 Paris (France); Sorbonnes Universités, UPMC Univ Paris 06, 75005 Paris (France); Thiel, Charles W.; Cone, Rufus L. [Department of Physics, Montana State University, Bozeman, Montana 59717 (United States); Ramírez, Mariola O.; Bausá, Luisa E. [Departamento Física de Materiales and Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, 28049 Madrid (Spain); Ikesue, Akio [World Laboratory, Mutsuno, Atsuta-ku, Nagoya 456-0023 (Japan)

    2015-09-01

    Homogeneous linewidths below 10 kHz are reported for the first time in high-quality Eu{sup 3+} doped Y {sub 2}O{sub 3} transparent ceramics. This result is obtained on the {sup 7}F{sub 0}→{sup 5}D{sub 0} transition in Eu{sup 3+} doped Y {sub 2}O{sub 3} ceramics and corresponds to an improvement of nearly one order of magnitude compared to previously reported values in transparent ceramics. Furthermore, we observed spectral hole lifetimes of ∼15 min that are long enough to enable efficient optical pumping of the nuclear hyperfine levels. Additionally, different Eu{sup 3+} concentrations (up to 1.0%) were studied, resulting in an increase of up to a factor of three in the peak absorption coefficient. These results suggest that transparent ceramics can be useful in applications where narrow and deep spectral holes can be burned into highly absorbing lines, such as quantum information processing and spectral filtering.

  15. Black Hole Mass Determination In the X-Ray Binary 4U 1630-47: Scaling of Spectral and Variability Characteristics

    Science.gov (United States)

    Seifina, Elena; Titarchuk, Lev; Shaposhnikov, Nikolai

    2014-01-01

    We present the results of a comprehensive investigation on the evolution of spectral and timing properties of the Galactic black hole candidate 4U 1630-47 during its spectral transitions. In particular, we show how a scaling of the correlation of the photon index of the Comptonized spectral component gamma with low-frequency quasi-periodic oscillations (QPOs), ?(sub L), and mass accretion rate, M, can be applied to the black hole mass and the inclination angle estimates.We analyze the transition episodes observed with the Rossi X-Ray Timing Explorer and BeppoSAX satellites.We find that the broadband X-ray energy spectra of 4U 1630-47 during all spectral states can be modeled by a combination of a thermal component, a Comptonized component, and a red-skewed iron-line component. We also establish that gamma monotonically increases during transition from the low-hard state to the high-soft state and then saturates for high mass accretion rates. The index saturation levels vary for different transition episodes. Correlations of gamma versus ?(sub L) also show saturation at gamma (is) approximately 3. Gamma -M and gamma -?(sub L) correlations with their index saturation revealed in 4U 1630-47 are similar to those established in a number of other black hole candidates and can be considered as an observational evidence for the presence of a black hole in these sources. The scaling technique, which relies on XTE J1550-564, GRO 1655-40, and H1743-322 as reference sources, allows us to evaluate a black hole mass in 4U 1630-47 yielding M(sub BH) (is) approximately 10 +/- 0.1 solar masses and to constrain the inclination angle of i (is) approximately less than 70 deg.

  16. Global analysis of the persistence of the spectral signal associated with burned areas

    Science.gov (United States)

    Melchiorre, A.; Boschetti, L.

    2015-12-01

    Systematic global burned area maps at coarse spatial resolution (350 m - 1 km) have been produced in the past two decades from several Earth Observation (EO) systems (including MODIS, Spot-VGT, AVHRR, MERIS), and have been extensively used in a variety of applications related to emissions estimation, fire ecology, and vegetation monitoring (Mouillot et al. 2014). There is however a strong need for moderate to high resolution (10-30 m) global burned area maps, in order to improve emission estimations, in particular on heterogeneous landscapes and for local scale air quality applications, for fire management and environmental restoration, and in support of carbon accounting (Hyer and Reid 2009; Mouillot et al. 2014; Randerson et al. 2012). Fires causes a non-permanent land cover change: the ash and charcoal left by the fire can be visible for a period ranging from a few weeks in savannas and grasslands ecosystems, to over a year in forest ecosystems (Roy et al. 2010). This poses a major challenge for designing a global burned area mapping system from moderate resolution (10-30 m) EO data, due to the low revisit time frequency of the satellites (Boschetti et al. 2015). As a consequence, a quantitative assessment of the permanence of the spectral signature of burned areas at global scale is a necessary step to assess the feasibility of global burned area mapping with moderate resolution sensors. This study presents a global analysis of the post-fire reflectance of burned areas, using the MODIS MCD45A1 global burned area product to identify the location and timing of burning, and the MO(Y)D09 global surface reflectance product to retrieve the time series of reflectance values after the fire. The result is a spatially explicit map of persistence of burned area signal, which is then summarized by landcover type, and by fire zone using the subcontinental regions defined by Giglio et al. (2006).

  17. Spectral Doppler findings in a rare case of acute compartment syndrome following leg burn

    Directory of Open Access Journals (Sweden)

    Omer A. Mahmoud

    2018-04-01

    Full Text Available Acute compartment syndrome (ACS is an orthopedic emergency condition, which is rarely attributed to burns. It occurs when pressure in an enclosed space rises to a point where it reduces blood flow and impairs tissue perfusion. Its consequences often lead to ischemia and possible necrosis within that space. Until now, the use of Doppler assessment to explore different types of compartment syndrome has yielded contradictory findings. Here, we present a significant increase of blood flow velocity in the arteries proximal to the burned area. Thus, the combination of Duplex ultrasound results with clinical findings will help vascular surgeons to make immediate decision to perform fasciotomy. Keywords: Compartment syndrome, Spectral Doppler

  18. PREVALENCE OF FOVEOLAR LUCENCY WITH DIFFERENT GAS TAMPONADES IN SURGICALLY CLOSED MACULAR HOLES ASSESSED BY SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY.

    Science.gov (United States)

    Zarranz-Ventura, Javier; Ellabban, Abdallah A; Sim, Dawn A; Keane, Pearse A; Kirkpatrick, James N; Sallam, Ahmed A B

    2017-07-07

    To evaluate the prevalence of foveolar lucency (FL) in surgically closed macular holes by spectral domain optical coherence tomography. One hundred forty-two eyes of 132 patients underwent pars plana vitrectomy, internal limiting membrane peeling, and gas tamponade in a 60-month time frame. Anatomical success and FL rates assessed by spectral domain optical coherence tomography, mean preoperative, and postoperative best-measured visual acuity and surgical details were retrospectively analyzed. Spectral domain optical coherence tomography confirmed closed holes with FL in 33.7% (34/101) of eyes at 1 month, 7.3% (9/123) at 3 months, 4.6% (6/129) at 6 months, and 3% (4/133) at 12 months. Prevalence of FL in closed holes at Month 1 was lower in C3F8-treated eyes (9.5%, 2/21) compared with C2F6 (40.9%, 18/44, P = 0.03) and SF6-treated eyes (38.9%, 14/36, P = 0.05). No differences were observed at Month 3. No differences in best-measured visual acuity change were observed between closed holes with or without FL at Month 1 (-0.14 ± 0.19 vs. -0.11 ± 0.23, P = 0.48) or any of the other time points. Temporary FL is a highly prevalent feature in successfully closed macular holes. Eyes treated with C3F8 gas had lower rates of FL at Month 1 than C2F6 and SF6-treated eyes. The presence of FL in closed holes does not seem to have any effect on the visual outcomes.

  19. Effect of Injector Nozzle Holes on Diesel Engine Performance

    OpenAIRE

    Semin,; Yusof, Mohd Yuzri Mohd; Arof, Aminuddin Md; Shaharudin, Daneil Tomo; Ismail, Abdul Rahim

    2010-01-01

    All of the injector nozzle holes have examined and the results are shown that the seven holes nozzle have provided the best burning result for the fuel in-cylinder burned in any different engine speeds and the best burning is in low speed engine. In engine performance effect, all of the nozzles have examined and the five holes nozzle provided the best result in indicted power, indicated torque and ISFC in any different engine speeds.

  20. Comments on the optical lineshape function: Application to transient hole-burned spectra of bacterial reaction centers

    Energy Technology Data Exchange (ETDEWEB)

    Reppert, Mike; Kell, Adam; Pruitt, Thomas [Department of Chemistry, Kansas State University, Manhattan, Kansas 66506 (United States); Jankowiak, Ryszard, E-mail: ryszard@ksu.edu [Department of Chemistry, Kansas State University, Manhattan, Kansas 66506 (United States); Department of Physics, Kansas State University, Manhattan, Kansas 66506 (United States)

    2015-03-07

    The vibrational spectral density is an important physical parameter needed to describe both linear and non-linear spectra of multi-chromophore systems such as photosynthetic complexes. Low-temperature techniques such as hole burning (HB) and fluorescence line narrowing are commonly used to extract the spectral density for a given electronic transition from experimental data. We report here that the lineshape function formula reported by Hayes et al. [J. Phys. Chem. 98, 7337 (1994)] in the mean-phonon approximation and frequently applied to analyzing HB data contains inconsistencies in notation, leading to essentially incorrect expressions in cases of moderate and strong electron-phonon (el-ph) coupling strengths. A corrected lineshape function L(ω) is given that retains the computational and intuitive advantages of the expression of Hayes et al. [J. Phys. Chem. 98, 7337 (1994)]. Although the corrected lineshape function could be used in modeling studies of various optical spectra, we suggest that it is better to calculate the lineshape function numerically, without introducing the mean-phonon approximation. New theoretical fits of the P870 and P960 absorption bands and frequency-dependent resonant HB spectra of Rb. sphaeroides and Rps. viridis reaction centers are provided as examples to demonstrate the importance of correct lineshape expressions. Comparison with the previously determined el-ph coupling parameters [Johnson et al., J. Phys. Chem. 94, 5849 (1990); Lyle et al., ibid. 97, 6924 (1993); Reddy et al., ibid. 97, 6934 (1993)] is also provided. The new fits lead to modified el-ph coupling strengths and different frequencies of the special pair marker mode, ω{sub sp}, for Rb. sphaeroides that could be used in the future for more advanced calculations of absorption and HB spectra obtained for various bacterial reaction centers.

  1. Comments on the optical lineshape function: Application to transient hole-burned spectra of bacterial reaction centers

    International Nuclear Information System (INIS)

    Reppert, Mike; Kell, Adam; Pruitt, Thomas; Jankowiak, Ryszard

    2015-01-01

    The vibrational spectral density is an important physical parameter needed to describe both linear and non-linear spectra of multi-chromophore systems such as photosynthetic complexes. Low-temperature techniques such as hole burning (HB) and fluorescence line narrowing are commonly used to extract the spectral density for a given electronic transition from experimental data. We report here that the lineshape function formula reported by Hayes et al. [J. Phys. Chem. 98, 7337 (1994)] in the mean-phonon approximation and frequently applied to analyzing HB data contains inconsistencies in notation, leading to essentially incorrect expressions in cases of moderate and strong electron-phonon (el-ph) coupling strengths. A corrected lineshape function L(ω) is given that retains the computational and intuitive advantages of the expression of Hayes et al. [J. Phys. Chem. 98, 7337 (1994)]. Although the corrected lineshape function could be used in modeling studies of various optical spectra, we suggest that it is better to calculate the lineshape function numerically, without introducing the mean-phonon approximation. New theoretical fits of the P870 and P960 absorption bands and frequency-dependent resonant HB spectra of Rb. sphaeroides and Rps. viridis reaction centers are provided as examples to demonstrate the importance of correct lineshape expressions. Comparison with the previously determined el-ph coupling parameters [Johnson et al., J. Phys. Chem. 94, 5849 (1990); Lyle et al., ibid. 97, 6924 (1993); Reddy et al., ibid. 97, 6934 (1993)] is also provided. The new fits lead to modified el-ph coupling strengths and different frequencies of the special pair marker mode, ω sp , for Rb. sphaeroides that could be used in the future for more advanced calculations of absorption and HB spectra obtained for various bacterial reaction centers

  2. Narrow spectral linewidth in InAs/InP quantum dot distributed feedback lasers

    Science.gov (United States)

    Duan, J.; Huang, H.; Lu, Z. G.; Poole, P. J.; Wang, C.; Grillot, F.

    2018-03-01

    This paper reports on the spectral linewidth of InAs/InP quantum dot distributed feedback lasers. Owing to a low inversion factor and a low linewidth enhancement factor, a narrow spectral linewidth of 160 kHz (80 kHz intrinsic linewidth) with a low sensitivity to temperature is demonstrated. When using anti-reflection coatings on both facets, narrow linewidth operation is extended to high powers, believed to be due to a reduction in the longitudinal spatial hole burning. These results confirm the high potential of quantum dot lasers for increasing transmission capacity in future coherent communication systems.

  3. What is black hole?

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. What is black hole? Possible end phase of a star: A star is a massive, luminous ball of plasma having continuous nuclear burning. Star exhausts nuclear fuel →. White Dwarf, Neutron Star, Black Hole. Black hole's gravitational field is so powerful that even ...

  4. Spectral and spatial resolving of photoelectric property of femtosecond laser drilled holes of GaSb(1-x)Bi(x).

    Science.gov (United States)

    Pan, C B; Zha, F X; Song, Y X; Shao, J; Dai, Y; Chen, X R; Ye, J Y; Wang, S M

    2015-07-15

    Femtosecond laser drilled holes of GaSbBi were characterized by the joint measurements of photoconductivity (PC) spectroscopy and laser-beam-induced current (LBIC) mapping. The excitation light in PC was focused down to 60 μm presenting the spectral information of local electronic property of individual holes. A redshift of energy band edge of about 6-8 meV was observed by the PC measurement when the excitation light irradiated on the laser drilled holes. The spatial resolving of photoelectric property was achieved by the LBIC mapping which shows "pseudo-holes" with much larger dimensions than the geometric sizes of the holes. The reduced LBIC current with the pseudo-holes is associated with the redshift effect indicating that the electronic property of the rim areas of the holes is modified by the femtosecond laser drilling.

  5. Burned Area Detection and Burn Severity Assessment of a Heathland Fire in Belgium Using Airborne Imaging Spectroscopy (APEX

    Directory of Open Access Journals (Sweden)

    Lennert Schepers

    2014-02-01

    Full Text Available Uncontrolled, large fires are a major threat to the biodiversity of protected heath landscapes. The severity of the fire is an important factor influencing vegetation recovery. We used airborne imaging spectroscopy data from the Airborne Prism Experiment (APEX sensor to: (1 investigate which spectral regions and spectral indices perform best in discriminating burned from unburned areas; and (2 assess the burn severity of a recent fire in the Kalmthoutse Heide, a heathland area in Belgium. A separability index was used to estimate the effectiveness of individual bands and spectral indices to discriminate between burned and unburned land. For the burn severity analysis, a modified version of the Geometrically structured Composite Burn Index (GeoCBI was developed for the field data collection. The field data were collected in four different vegetation types: Calluna vulgaris-dominated heath (dry heath, Erica tetralix-dominated heath (wet heath, Molinia caerulea (grass-encroached heath, and coniferous woodland. Discrimination between burned and unburned areas differed among vegetation types. For the pooled dataset, bands in the near infrared (NIR spectral region demonstrated the highest discriminatory power, followed by short wave infrared (SWIR bands. Visible wavelengths performed considerably poorer. The Normalized Burn Ratio (NBR outperformed the other spectral indices and the individual spectral bands in discriminating between burned and unburned areas. For the burn severity assessment, all spectral bands and indices showed low correlations with the field data GeoCBI, when data of all pre-fire vegetation types were pooled (R2 maximum 0.41. Analysis per vegetation type, however, revealed considerably higher correlations (R2 up to 0.78. The Mid Infrared Burn Index (MIRBI had the highest correlations for Molinia and Erica (R2 = 0.78 and 0.42, respectively. In Calluna stands, the Char Soil Index (CSI achieved the highest correlations, with R2 = 0

  6. Silhouette and spectral line profiles in the special modification of the Kerr black hole geometry generated by quintessential fields

    Energy Technology Data Exchange (ETDEWEB)

    Schee, Jan; Stuchlik, Zdenek [Silesian University in Opava, Faculty of Philosophy and Science, Institute of Physics and Research Centre for Theoretical Physics and Astrophysics, Opava (Czech Republic)

    2016-11-15

    We study optical effects in quintessential Kerr black hole spacetimes corresponding to the limiting case of the equation-of-state parameter ω{sub q} = -1/3 of the quintessence. In dependence on the dimensionless quintessential field parameter c, we determine the black hole silhouette and the spectral line profiles of Keplerian disks generated in this special quintessential Kerr geometry, representing an extension of the general modifications of the Kerr geometry introduced recently by Ghasemi-Nodehi and Bambi (Eur. Phys. J. C 56:290, 2016). We demonstrate that due to the influence of the parameter c, the silhouette is almost homogeneously enlarged, and the spectral line profiles are redshifted with almost conserved shape. (orig.)

  7. Determination of the electron-hole pair creation energy for semiconductors from the spectral responsivity of photodiodes

    CERN Document Server

    Scholze, F; Kuschnerus, P; Rabus, H; Richter, M; Ulm, G

    2000-01-01

    Ionizing radiation can be detected by the measurement of the charge carriers produced in a detector. The improved semiconductor technology now allows detectors operating near the physical limits of the detector materials to be designed. The mean energy required for producing an electron-hole pair, W, is a material property of the semiconductor. Here, the determination of W from the spectral responsivity of photodiodes is demonstrated. Using spectrally dispersed synchrotron radiation, different types of semiconductor photodiodes have been examined in the UV-, VUV-, and soft X-ray spectral range. Their spectral responsivity was determined with relative uncertainties between 0.4% and 1% using a cryogenic electrical-substitution radiometer as primary detector standard. Results are presented for silicon n-on-p junction photodiodes and for GaAsP/Au Schottky diodes at room temperature. The investigations for silicon covered the complete spectral range from 3 to 1500 eV, yielding a constant value W=(3.66+-0.03) eV fo...

  8. Fast spectral source integration in black hole perturbation calculations

    Science.gov (United States)

    Hopper, Seth; Forseth, Erik; Osburn, Thomas; Evans, Charles R.

    2015-08-01

    This paper presents a new technique for achieving spectral accuracy and fast computational performance in a class of black hole perturbation and gravitational self-force calculations involving extreme mass ratios and generic orbits. Called spectral source integration (SSI), this method should see widespread future use in problems that entail (i) a point-particle description of the small compact object, (ii) frequency domain decomposition, and (iii) the use of the background eccentric geodesic motion. Frequency domain approaches are widely used in both perturbation theory flux-balance calculations and in local gravitational self-force calculations. Recent self-force calculations in Lorenz gauge, using the frequency domain and method of extended homogeneous solutions, have been able to accurately reach eccentricities as high as e ≃0.7 . We show here SSI successfully applied to Lorenz gauge. In a double precision Lorenz gauge code, SSI enhances the accuracy of results and makes a factor of 3 improvement in the overall speed. The primary initial application of SSI—for us its the raison d'être—is in an arbitrary precision mathematica code that computes perturbations of eccentric orbits in the Regge-Wheeler gauge to extraordinarily high accuracy (e.g., 200 decimal places). These high-accuracy eccentric orbit calculations would not be possible without the exponential convergence of SSI. We believe the method will extend to work for inspirals on Kerr and will be the subject of a later publication. SSI borrows concepts from discrete-time signal processing and is used to calculate the mode normalization coefficients in perturbation theory via sums over modest numbers of points around an orbit. A variant of the idea is used to obtain spectral accuracy in a solution of the geodesic orbital motion.

  9. Resonance Enhanced Multi-Photon Ionization and Uv-Uv Hole-Burning Spectroscopic Studies of Jet-Cooled Acetanilide Derivatives

    Science.gov (United States)

    Moon, Ceol Joo; Min, Ahreum; Ahn, Ahreum; Lee, Seung Jun; Choi, Myong Yong; Kim, Seong Keun

    2013-06-01

    Conformational investigations and photochemistry of jet-cooled methacetine (MA) and phenacetine (PA) using one color resonant two-photon ionization (REMPI), UV-UV hole-burning and IR-dip spectroscopy are presented. MA and PA are derivatives of acetanilide, substituted by methoxyl, ethoxyl group in the para position of acetanilide, respectively. Moreover, we have investigated conformational information of the acetanilide derivatives (AAP, MA and PA)-water. In this work, we will present and discuss the solvent effects of the hydroxyl group of acetanilide derivatives in the excited state.

  10. Evidence for a Very Early Intermediate in Bacterial Photosynthesis. A Photon-Echo and Hole-Burning Study of the Primary Donor Band in Rhodopseudomonas Sphaeroides

    NARCIS (Netherlands)

    Meech, S.R.; Hoff, A.J.

    1985-01-01

    Two coherent spectroscopic methods, accumulated photon echo and population bottleneck hole-burning, have been employed in a study of the decay rate of the primary donor (P) of Rhodopseudomonas sphaeroides at 1.5 K. The decay rate is instrument-limited in the photon-echo experiment, implying a

  11. The Burn Medical Assistant: Developing Machine Learning Algorithms to Aid in the Estimation of Burn Wound Size

    Science.gov (United States)

    2017-10-01

    Produce multi-spectral burn wound images and enhanced burn wound diagrams for automated, multi- spectral feature extraction and image segmentation ...Raytheon will not occur, this in conjunction with ARA, we are in the process of market research with currently available Commercial off the Shelf (COTS...thorough market survey of current COTS technology and after review of the technology offered by RVS. This system offers the necessary resolution

  12. A new metric for quantifying burn severity: The Relativized Burn Ratio

    Science.gov (United States)

    Sean A. Parks; Gregory K. Dillon; Carol Miller

    2014-01-01

    Satellite-inferred burn severity data have become increasingly popular over the last decade for management and research purposes. These data typically quantify spectral change between pre-and post-fire satellite images (usually Landsat). There is an active debate regarding which of the two main equations, the delta normalized burn ratio (dNBR) and its relativized form...

  13. Naphthalocyanine-based time reversal mirror at 800 nm

    International Nuclear Information System (INIS)

    Galaup, Jean-Pierre; Fraigne, Sebastien; Le Goueet, Jean-Louis; Likforman, Jean-Pierre; Joffre, Manuel

    2004-01-01

    We performed pulse shaping and time reversal experiments using spectral holography based on persistent spectral hole burning in free-base naphthalocyanine-doped films. The application of a new pulse re-compression scheme based on a programmable hole burning material acting as a time reversal mirror is considered. In this work, we adapted the Fourier transform spectral interferometry technique for measuring the amplitude and phase of photon echo signals produced by diffraction of femtosecond pulses on a spectral hologram. We therefore demonstrated that we could control the pulses diffracted from the hologram by shaping and then characterizing these pulses in both amplitude and phase by spectral interferometry

  14. Spectrally selective molecular doped solids: spectroscopy, photophysics and their application to ultrafast optical pulse processing

    International Nuclear Information System (INIS)

    Galaup, Jean-Pierre

    2005-01-01

    The persistent spectral hole-burning (PSHB) phenomenon observed in molecular doped polymers cooled down to liquid helium temperatures allows the engraving of spectral structures in the inhomogeneous absorption profile of the material. This phenomenon known since 1974 has became a fruitful field for the study of the intimacy of complex molecular systems in the solid state, revealing high-resolution spectroscopy, photophysics, photochemistry and dynamics of molecular doped amorphous media, organic as well as inorganic. A PSHB molecular doped solid can be programmed in spectral domain and therefore, it can be converted in an optical processor capable to achieve user-defined optical functions. Some aspects of this field are illustrated in the present paper. An application is presented where a naphthalocyanine doped polymer film is used in a demonstrative experiment to prove that temporal aberration free re-compression of ultra-short light pulses is feasible. Perspectives for the coherent control of light fields or photochemical processes are also evoked

  15. Equivalent Black Carbon measurements and spectral analysis of absorption coefficient during a biomass burning episode in the city of Bogotá, Colombia.

    Science.gov (United States)

    Quirama, M.; Morales, R.

    2016-12-01

    Light-absorbing carbonaceous aerosol is recognized as a significant short lived climate pollutant that can contribute to direct and indirect radiative forcing. In urban environments, black carbon is an important contributor to the deterioration of local air quality. In this study, we report measurements of equivalent Black Carbon performed during the months of January, February, and March 2016 in the city of Bogotá, Colombia. During this period, a persistent condition of atmospheric stability lead to high concentrations of particulate matter throughout the city. During the month of February, the city was further impacted by a series of small-scale forest fires that took place on hills neighboring the city center. Equivalent Black Carbon (eBC) concentrations were monitored before, during, and after a mayor forest fire episode with a 7-wavelength Aethalometer. The monitoring instruments were located at a traffic impacted site, 18.3 km from the forest fire. To evaluate the contribution of biomass burning to the light-absorbing aerosol particle concentration, spectral analysis of the absorption coefficient of the sampled aerosol particles was performed. When the biomass burning plume directly impacted the monitoring station during the night of February 4, eBC concentrations of up to 40 µg/m3 were observed at nighttime. This concentration was significantly higher than average nighttime concentrations of eBC, observed to be 4 µg/m3 at the site. However, during the period most intensely affected by the biomass burning plume, the angstrom exponent computed between the 450nm and the 970 nm channel, was found to be close to 1. Angstrom exponent close to 1 is an indication that the contribution from traffic generated black carbon is dominant compared to the contribution of biomass burning. The data set collected during this period suggests that despite the significant contribution of the fresh biomass burning plume to the particulate matter concentration in the city, the

  16. Effect of hole geometry and Electric-Discharge Machining (EDM) on airflow rates through small diameter holes in turbine blade material

    Science.gov (United States)

    Hippensteele, S. A.; Cochran, R. P.

    1980-01-01

    The effects of two design parameters, electrode diameter and hole angle, and two machine parameters, electrode current and current-on time, on air flow rates through small-diameter (0.257 to 0.462 mm) electric-discharge-machined holes were measured. The holes were machined individually in rows of 14 each through 1.6 mm thick IN-100 strips. The data showed linear increase in air flow rate with increases in electrode cross sectional area and current-on time and little change with changes in hole angle and electrode current. The average flow-rate deviation (from the mean flow rate for a given row) decreased linearly with electrode diameter and increased with hole angle. Burn time and finished hole diameter were also measured.

  17. ENERGY-DEPENDENT POWER SPECTRAL STATES AND ORIGIN OF APERIODIC VARIABILITY IN BLACK HOLE BINARIES

    International Nuclear Information System (INIS)

    Yu Wenfei; Zhang Wenda

    2013-01-01

    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.

  18. White Dwarfs, Neutron Stars and Black Holes

    Science.gov (United States)

    Szekeres, P.

    1977-01-01

    The three possible fates of burned-out stars: white dwarfs, neutron stars and black holes, are described in elementary terms. Characteristics of these celestial bodies, as provided by Einstein's work, are described. (CP)

  19. Numerical modeling of optical coherent transient processes with complex configurations-III: Noisy laser source

    International Nuclear Information System (INIS)

    Chang Tiejun; Tian Mingzhen

    2007-01-01

    A previously developed numerical model based on Maxwell-Bloch equations was modified to simulate optical coherent transient and spectral hole burning processes with noisy laser sources. Random walk phase noise was simulated using laser-phase sequences generated numerically according to the normal distribution of the phase shift. The noise model was tested by comparing the simulated spectral hole burning effect with the analytical solution. The noise effects on a few typical optical coherence transient processes were investigated using this numerical tool. Flicker and random walk frequency noises were considered in accumulation process

  20. Coherent hole burning and Mollow absorption effects in the cycling transition Fe=0↔Fg=1 subject to a magnetic field

    International Nuclear Information System (INIS)

    Gu Ying; Sun Qingqing; Gong Qihuang

    2004-01-01

    With saturation and probing by circularly polarized fields, quantum coherence effects are investigated for the cycling transition F e =0↔F g =1, which is subject to a linearly polarized field and a magnetic field. The saturation field is applied to the case of maximum coherence between the drive Rabi frequency and magnetic field, corresponding to the electromagnetically induced absorption (EIA) with negative dispersion found by Gu et al. For a small saturation Rabi frequency, holes are burned in two Autler-Towns peaks outside two symmetric electromagnetically induced transparency windows due to the two-photon resonance. However, when the saturation Rabi frequency is comparable with the drive Rabi frequency, holes caused by the coherent population oscillation appear in the EIA spectrum. Finally, when the saturation Rabi frequency is large enough, several emission peaks are observed due to the Mollow absorption effects. Furthermore, the dispersion at the pump-probe detuning center is kept negative with an increase in saturation field, which is a precursor of superluminal light propagation

  1. High-resolution laser spectroscopy of rare-earth doped insulators: a personal perspective

    International Nuclear Information System (INIS)

    Macfarlane, Roger M.

    2002-01-01

    I offer some reflections on the past three decades of high-resolution spectroscopy of rare-earth ions in solids which was ushered in by the development of tunable lasers in the mid 1970s. A brief review is given of some of the accomplishments in the area of spectral hole-burning and coherent transient spectroscopy, emphasizing work with which the author has been associated. Spectral hole-burning has been characterized by a richness of mechanisms. These include population storage in nuclear-spin and electron-spin Zeeman sub-levels, hyperfine and superhyperfine levels and metastable optical levels with corresponding hole lifetimes from many hours to microseconds. In addition, persistent hole-burning has been seen in disordered materials and in those showing photo-ionization or photo-chemistry following excitation into zero-phonon lines. This has made hole-burning a generally useful technique for the measurement of magnetic and electric dipole moments, hyperfine interactions, spin relaxation and thermally induced line-broadening. Photon-echoes have proven to be the prime source of coherence-time information and coherence times as long as several milliseconds corresponding to optical resonance widths of less than 100 Hz have been reported. Tables summarizing these results and providing references to original work are included

  2. X-Ray Timing and Spectral Observations of Galactic Black Hole Candidate XTE J1550--564 During Outburst

    Energy Technology Data Exchange (ETDEWEB)

    Reilly, Kaice T

    2002-12-11

    Soft X-ray transients (SXTs), a sub-class of low-mass X-ray binaries (LMXBs), provide a unique opportunity to test General Relativity and to probe fundamental physics under conditions terrestrially unattainable. SXT outbursts are of great interest because they allow the study of LMXBs under a wide range of accretion rates. The majority of known SXTs contain black holes, therefore SXT outbursts are key to understanding accretion physics around black holes and in active galactic nuclei, which are thought to contain supermassive, M {approx} 10{sup 6} - 10{sup 10} M{circle_dot}, where M{circle_dot} is one solar mass, central compact objects. These compact objects are most likely black holes, which exhibit, on a much larger scale, accretion physics similar to that around black holes in SXTs. In this work, the timing and spectral properties of the SXT and microquasar XTE J1550-564 during outburst are studied. Observations made by the Unconventional Stellar Aspect (USA) Experiment on board the Advanced Research and Global Observation Satellite (ARGOS) are emphasized. USA data show a low-frequency quasi-periodic oscillation (LFQPO) with a centroid frequency that tends to increase with increasing USA flux and a fractional rms amplitude which is correlated with the USA hardness ratio (4-16 keV/1-4 keV). Several high-frequency quasi-periodic oscillations (HFQPOs) were detected by the Rossi X-ray Timing Explorer (RXTE), during periods where the LFQPO is seen to be weakening or not detectable at all. The evolution of the USA hardness ratio with time and source flux is examined. The hardness-intensity diagram shows counterclockwise cyclical evolution and possibly indicates the presence of two independent accretion flows: a geometrically thin, optically thick accretion disk and a hot sub-Keplerian flow.

  3. Total spectral distributions from Hawking radiation

    Energy Technology Data Exchange (ETDEWEB)

    Broda, Boguslaw [University of Lodz, Department of Theoretical Physics, Faculty of Physics and Applied Informatics, Lodz (Poland)

    2017-11-15

    Taking into account the time dependence of the Hawking temperature and finite evaporation time of the black hole, the total spectral distributions of the radiant energy and of the number of particles have been explicitly calculated and compared to their temporary (initial) blackbody counterparts (spectral exitances). (orig.)

  4. BL Lacertae: X-ray spectral evolution and a black-hole mass estimate

    Science.gov (United States)

    Titarchuk, Lev; Seifina, Elena

    2017-06-01

    We present an analysis of the spectral properties observed in X-rays from active galactic nucleus BL Lacertae using RXTE, Suzaku, ASCA, BeppoSAX, and Swift observations. The total time covered by these observations is approximately 20 yr. We show strong observational evidence that this source undergoes X-ray spectral transitions from the low hard state (LHS) through the intermediate state (IS) to the high soft state (HSS) during these observations. During the RXTE observations (1997-2001, 180 ks, for a total 145 datasets), the source was approximately 75%, 20% and only 5% of the time in the IS, LHS, and HSS, respectively. We also used Swift observations (470 datasets, for a total 800 ks), which occurred during 12 yr (2005-2016), the broadband (0.3-200 keV) data of BeppoSAX (1997-2000, 160 ks), and the low X-ray energy (0.3-10 keV) data of ASCA (1995-1999, 160 ks). Two observations of Suzaku (2006, 2013; 50 ks) in combinations with long-term RXTE and Swift data-sets fortunately allow us to describe all spectral states of BL Lac. The spectra of BL Lac are well fitted by the so-called bulk motion Comptonization (BMC) model for all spectral states. We have established the photon index saturation level, Γsat = 2.2 ± 0.1, in the Γ versus mass accretion rate (Ṁ) correlation. This Γ - Ṁ correlation allows us to estimate the black-hole (BH) mass in BL Lac to be MBH 3 × 107M⊙ for a distance of 300 Mpc. For the BH mass estimate, we use the scaling method taking stellar-mass Galactic BHs 4U 1543-47 and GX 339-4 as reference sources. The Γ - Ṁ correlation revealed in BL Lac is similar to those in a number of stellar-mass Galactic BHs and two recently studied intermediate-mass extragalactic BHs. It clearly shows the correlation along with the very extended Γ saturation at 2.2. This is robust observational evidence for the presence of a BH in BL Lac. We also reveal that the seed (disk) photon temperatures are relatively low, of order of 100 eV, which are consistent

  5. The black hole information paradox and highly squeezed interior quantum fluctuations

    Science.gov (United States)

    Oshita, Naritaka

    2017-10-01

    Almheiri, Marolf, Polchinski, and Sully argued that, for a consistent black hole evaporation process, the horizon of a sufficiently old black hole should be replaced by a ‘firewall’ at which an infalling observer burns up, which obviously leads to the violation of the equivalence principle. We propose that once the infalling partner of an outgoing Hawking particle approaches a black hole singularity, it experiences decoherence and the loss of its entanglement with the outgoing Hawking particle. This implies we would no longer need firewalls to avoid the black hole information paradox.

  6. The black hole information paradox and highly squeezed interior quantum fluctuations

    International Nuclear Information System (INIS)

    Oshita, Naritaka

    2017-01-01

    Almheiri, Marolf, Polchinski, and Sully argued that, for a consistent black hole evaporation process, the horizon of a sufficiently old black hole should be replaced by a ‘firewall’ at which an infalling observer burns up, which obviously leads to the violation of the equivalence principle. We propose that once the infalling partner of an outgoing Hawking particle approaches a black hole singularity, it experiences decoherence and the loss of its entanglement with the outgoing Hawking particle. This implies we would no longer need firewalls to avoid the black hole information paradox. (paper)

  7. Revelations of X-ray spectral analysis of the enigmatic black hole binary GRS 1915+105

    Science.gov (United States)

    Peris, Charith; Remillard, Ronald A.; Steiner, James; Vrtilek, Saeqa Dil; Varniere, Peggy; Rodriguez, Jerome; Pooley, Guy

    2016-01-01

    Of the black hole binaries discovered thus far, GRS 1915+105 stands out as an exceptional source primarily due to its wild X-ray variability, the diversity of which has not been replicated in any other stellar-mass black hole. Although extreme variability is commonplace in its light-curve, about half of the observations of GRS1915+105 show fairly steady X-ray intensity. We report on the X-ray spectral behavior within these steady observations. Our work is based on a vast RXTE/PCA data set obtained on GRS 1915+105 during the course of its entire mission and 10 years of radio data from the Ryle Telescope, which overlap the X-ray data. We find that the steady observations within the X-ray data set naturally separate into two regions in a color-color diagram, which we refer to as steady-soft and steady-hard. GRS 1915+105 displays significant curvature in the Comptonization component within the PCA band pass suggesting significantly heating from a hot disk present in all states. A new Comptonization model 'simplcut' was developed in order to model this curvature to best effect. A majority of the steady-soft observations display a roughly constant inner radius; remarkably reminiscent of canonical soft state black hole binaries. In contrast, the steady-hard observations display a growing disk truncation that is correlated to the mass accretion rate through the disk, which suggests a magnetically truncated disk. A comparison of X-ray model parameters to the canonical state definitions show that almost all steady-soft observations match the criteria of either thermal or steep power law state, while the thermal state observations dominate the constant radius branch. A large portion (80%) of the steady-hard observations matches the hard state criteria when the disk fraction constraint is neglected. These results suggest that within the complexity of this source is a simpler underlying basis of states, which map to those observed in canonical black hole binaries. When

  8. Connections Between Jet Formation and Multiwavelength Spectral Evolution in Black Hole Transients

    Science.gov (United States)

    Kakemci, Emrah; Chun, Yoon-Young; Dincer, Tolga; Buxton, Michelle; Tomsick, John A.; Corbel, Stephane; Kaaret, Philip

    2011-01-01

    Multiwavelength observations are the key to understand conditions of jet formation in Galactic black hole transient (GBHT) systems. By studying radio and optical-infrared evolution of such systems during outburst decays, the compact jet formation can be traced. Comparing this with X-ray spectral and timing evolution we can obtain physical and geometrical conditions for jet formation, and study the contribution of jets to X-ray emission. In this work, first X-ray evolution - jet relation for XTE J1752-223 will be discussed. This source had very good coverage in X-rays, optical, infrared and radio. A long exposure with INTEGRAL also allowed us to study gamma-ray behavior after the jet turns on. We will also show results from the analysis of data from GX 339-4 in the hard state with SUZAKU at low flux levels. The fits to iron line fluorescence emission show that the inner disk radius increases by a factor of greater than 27 with respect to radii in bright states. This result, along with other disk radius measurements in the hard state will be discussed within the context of conditions for launching and sustaining jets.

  9. Incidence and distribution of paravascular lamellar holes and their relationship with macular retinoschisis in highly myopic eyes using spectral-domain oct.

    Science.gov (United States)

    Vela, José I; Sánchez, Fernando; Díaz-Cascajosa, Jesús; Mingorance, Ester; Andreu, David; Buil, José A

    2016-04-01

    The purpose of the study is to determine the incidence and distribution of paravascular lamellar holes (PLH) around retinal vessels in highly myopic eyes and their relationship with macular retinoschisis (MR). We examined 306 eyes of 178 patients with high myopia, performing multiple scans of the posterior pole within the retinal vascular arcades using spectral-domain OCT. Type of staphyloma was determined. PLH were divided into three groups: holes only (group 1), holes extending below vessels (group 2), and holes in an area of paravascular retinoschisis (group 3). OCT showed that 96/306 eyes (31.4 %) had PLH mainly along the infero-temporal arcade (39.9 %). Type V and IX staphylomas had a higher proportion of PLH in the infero-temporal arcade than other staphylomas. Group 3 eyes presented higher rates of myopia and staphyloma. MR was detected in 10/27 eyes (37 %) in Group 3, but only in 2/33 eyes (6.1 %) in Group 1. No MR was found in Group 2. PLH are relatively common in highly myopic eyes and mainly distributed in the inferior temporal arcade. Findings from this descriptive study suggest that distribution of PLH might be related to the type of staphyloma. Further studies are needed to evaluate the relevance of PLH in the pathogenesis of MR.

  10. Pupillometry reveals the physiological underpinnings of the aversion to holes.

    Science.gov (United States)

    Ayzenberg, Vladislav; Hickey, Meghan R; Lourenco, Stella F

    2018-01-01

    An unusual, but common, aversion to images with clusters of holes is known as trypophobia. Recent research suggests that trypophobic reactions are caused by visual spectral properties also present in aversive images of evolutionary threatening animals (e.g., snakes and spiders). However, despite similar spectral properties, it remains unknown whether there is a shared emotional response to holes and threatening animals. Whereas snakes and spiders are known to elicit a fear reaction, associated with the sympathetic nervous system, anecdotal reports from self-described trypophobes suggest reactions more consistent with disgust, which is associated with activation of the parasympathetic nervous system. Here we used pupillometry in a novel attempt to uncover the distinct emotional response associated with a trypophobic response to holes. Across two experiments, images of holes elicited greater constriction compared to images of threatening animals and neutral images. Moreover, this effect held when controlling for level of arousal and accounting for the pupil grating response. This pattern of pupillary response is consistent with involvement of the parasympathetic nervous system and suggests a disgust, not a fear, response to images of holes. Although general aversion may be rooted in shared visual-spectral properties, we propose that the specific emotion is determined by cognitive appraisal of the distinct image content.

  11. Photoinduced electric dipole in CuCl quantum dots

    International Nuclear Information System (INIS)

    Masumoto, Yasuaki; Naruse, Fumitaka; Kanno, Atsushi

    2003-01-01

    Electromodulated absorption spectra of CuCl quantum dots modulated at twice the modulation frequency of electric field, 2f, show prominent structure around persistently burned hole. It grows in proportion to square of the electric field in the same manner as the 2f component of electromodulated absorption spectra of the dots without the laser exposure. Even the f component of electromodulated signal was observed around the burned hole position. These observations are explained by considering electric dipole formed in hole burned and photoionized quantum dots. Photoionization not only produces persistent spectral hole burning but also the local built-in electric field and photoinduced dipole moment in quantum dots. The dipole moment is estimated to be about 5 debye for 3.2-nm-radius quantum dots. The dipole moments are randomly oriented but 1% anisotropy is deduced from the electromodulated signal at f

  12. Evans hole and non linear optical activity in Bis(melaminium) sulphate dihydrate: A vibrational spectral study.

    Science.gov (United States)

    Suresh Kumar, V R; Binoy, J; Dawn Dharma Roy, S; Marchewka, M K; Jayakumar, V S

    2015-01-01

    Bis(melaminium) sulphate dihydrate (BMSD), an interesting melaminium derivative for nonlinear optical activity, has been subjected to vibrational spectral analysis using FT IR and FT Raman spectra. The analysis has been aided by the Potential Energy Distribution (PED) of vibrational spectral bands, derived using density functional theory (DFT) at B3LYP/6-31G(d) level. The geometry is found to correlate well with the XRD structure and the band profiles for certain vibrations in the finger print region have been theoretically explained using Evans hole. The detailed Natural Bond Orbital (NBO) analysis of the hydrogen bonding in BMSD has also been carried out to understand the correlation between the stabilization energy of hyperconjugation of the lone pair of donor with the σ(∗) orbital of hydrogen-acceptor bond and the strength of hydrogen bond. The theoretical calculation shows that BMSD has NLO efficiency, 2.66 times that of urea. The frontier molecular orbital analysis points to a charge transfer, which contributes to NLO activity, through N-H…O intermolecular hydrogen bonding between the melaminium ring and the sulphate. The molecular electrostatic potential (MEP) mapping has also been performed for the detailed analysis of the mutual interactions between melaminium ring and sulphate ion. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Brown dwarfs and black holes

    International Nuclear Information System (INIS)

    Tarter, J.C.

    1978-01-01

    The astronomical missing-mass problem (the discrepancy between the dynamical mass estimate and the sum of individual masses in large groupings) is considered, and possible explanations are advanced. The existence of brown dwarfs (stars not massive enough to shine by nuclear burning) and black holes (extremely high density matter contraction such that gravitation allows no light emission) thus far provides the most plausible solutions

  14. Quantifying spatial variability of depth of peat burn in wetlands in relation to antecedent characteristics using field data, multi-temporal and multi-spectral LiDAR

    Science.gov (United States)

    Chasmer, L.; Flade, L.; Virk, R.; Montgomery, J. S.; Hopkinson, C.; Thompson, D. K.; Petrone, R. M.; Devito, K.

    2017-12-01

    Landscape changes in the hydrological characteristics of wetlands in some parts of the Boreal region of Canada are occurring as a result of climate-induced feedbacks and anthropogenic disturbance. Wetlands are largely resilient to wildfire, however, natural, climatic and anthropogenic disturbances can change surface water regimes and predispose wetlands to greater depth of peat burn. Over broad areas, peat loss contributes to significant pollution emissions, which can affect community health. In this study, we a) quantify depth of peat burn and relationships to antecedent conditions (species type, topography, surficial geology) within three classified wetlands found in the Boreal Plains ecoregion of western Canada; and b) examine the impacts of wildfire on post-fire ground surface energy balance to determine how peat loss might affect local hydro-climatology and surface water feedbacks. High-resolution optical imagery, pre- and post-burn multi-spectral Light Detection And Ranging (LiDAR), airborne thermal infrared imagery, and field validation data products are integrated to identify multiple complex interactions within the study wetlands. LiDAR-derived depth of peat burn is within 1 cm (average) compared with measured (RMSE = 9 cm over the control surface), demonstrating the utility of LiDAR with high point return density. Depth of burn also correlates strongly with variations in Normalised Burn Ratio (NBR) determined for ground surfaces only. Antecedent conditions including topographic position, soil moisture, soil type and wetland species also have complex interactions with depth of peat loss within wetlands observed in other studies. However, while field measurements are important for validation and understanding eco-hydrological processes, results from remote sensing are spatially continuous. Temporal LiDAR data illustrate the full range of variability in depth of burn and wetland characteristics following fire. Finally, measurements of instantaneous surface

  15. Spectral features of radiation from Nordstroem and Kerr-Newman white holes. [Kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Dadhich, N [Poona Univ. (India). Dept. of Mathematics and Statistics

    1977-01-01

    Unlike the Schwarzschild white hole, Nordstroem and Kerr-Newman white holes cannot explode right down from the space time singularity R = 0. For example a charged white hole has to commence explosion (i.e., comes into existence) with a radius Rsub(o)=Rsub(c)(2-Rsub(c)/Rsub(b))sup(-1) where Rsub(c) is the 'classical radius' and Rsub(b) is the final radius attained when the stationary state is reached. That means charged and rotating black holes also cannot hit the singularity R = 0 and perish. Here the explosion is decelerated by the presence of charge and rotation and hence the radiation emitted would be not as energetic as in the Schwarzschild case where its energy is infinitely large for emission from R = 0.

  16. The effect of particle-hole interaction on the XPS core-hole spectrum

    International Nuclear Information System (INIS)

    Ohno, Masahide; Sjoegren, Lennart

    2004-01-01

    How the effective particle-hole interaction energy, U, or the polarization effect on a secondary electron in a final two-hole one-particle (2h1p) state created by the Coster-Kronig (CK) transition can solely affect the density of the CK particle states and consequently the core-hole spectral function, is discussed. The X-ray photoelectron spectroscopy (XPS) core-hole spectrum is predominantly governed by the unperturbed initial core-hole energy relative to the zero-point energy. At the latter energy, the real part of the initial core-hole self-energy becomes zero (no relaxation energy shift) and the imaginary part (the lifetime broadening) approximately maximizes. The zero-point energy relative to the double-ionization threshold energy is governed by the ratio of U relative to the bandwidth of the CK continuum. As an example, we study the 5p XPS spectra of atomic Ra (Z=88), Th (Z=90) and U (Z=92). The spectra are interpreted in terms of the change in the unperturbed initial core-hole energy relative to the zero-point energy. We explain why in general an ab initio atomic many-body calculation can provide an overall good description of solid-state spectra predominantly governed by the atomic-like localized core-hole dynamics. We explain this in terms of the change from free atom to metal in both U and the zero-point energy (self-energy)

  17. Stability of the nonequilibrium states of a superconductor with a finite difference between the populations of the electron- and hole-like spectral branches

    International Nuclear Information System (INIS)

    Gal'perin, Y.M.; Kozub, V.I.; Spivak, B.Z.

    1981-01-01

    The stability of the nonequilibrium states of a superconductor with a finite difference between the populations of the electron- and hole-like spectral branches is investigated. It is shown that an instability similar to the Cooper instability of a normal metal arises at a sufficiently large value of the imbalance. This eliminates the imbalance within quantum-mechanical (nonkinetic) time periods. The consistency of the allowance for the imbalance in the nonequilibrium Ginzburg-Landau equations is discussed

  18. Combined Spectral and Timing Analysis of the Black Hole Candidate MAXI J1659-152 Discovered by MAXI and Swift

    Science.gov (United States)

    Yamaoka, Kazutaka; Allured, Ryan; Kaaret, Philip; Kennea, Jamie A.; Kawaguchi, Toshihiro; Gandhi, Poshak; Shaposhnikov, Nicholai; Ueda, Yoshihiro; Nakahira, Satoshi; Kotani, Taro; hide

    2011-01-01

    We report on X-ray spectral and timing results of the new black hole candidate (BHC) MAXI J1659-152 with the orbital period of 2.41 hours (shortest among BHCs) in the 2010 outburst from 65 Rossi X-ray Timing Explorer (RXTE) observations and 8 simultaneous Swift and RXTE observations. According to the definitions of the spectral states in Remillard & McClintock (2006), most of the observations have been classified into the intermediate state. All the X-ray broadband spectra can be modeled by a multi-color disk plus a power-law with an exponential cutoff or a multi-color disk plus a Comptonization component. During the initial phase of the outburst, a high energy cutoff was visible at 30-40 keV. The innermost radius of the disk gradually decreased by a factor of more than 3 from the onset of the outburst and reached a constant value of 35 d(sub 10)cos(i sup -1/2) km, where d(sub 10) is the distance in units of 10 kpc and i is the inclination. The type-C quasi-periodic oscillation (QPO) frequency varied from 1.6 Hz to 7.3 Hz in association with a change of the innermost radius, while the innermost radius remained constant during the type-B QPO detections at 1.6-4.1 Hz. Hence, we suggest that the origin of the type-B QPOs is different from that of type-C QPOs, the latter of which would originate from the disk truncation radius. Assuming the constant innermost radius in the latter phase of the outburst as the innermost stable circular orbit, the black hole mass in MAXI J1659-152 is estimated to be 3.6-8.0 solar mass for a distance of 5.3-8.6 kpc and an inclination angle of 60-75 degrees.

  19. Standing Shocks around Black Holes and Estimation of Outflow ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Abstract. We self-consistently obtain shock locations in an accretion flow by using an analytical method. One can obtain the spectral properties, quasi-periodic oscillation frequencies and the outflow rates when the inflow parameters are known. Since temperature of the CENBOL decides the spectral states of the black hole, ...

  20. Spectral properties of the accretion discs around rotating black holes

    Indian Academy of Sciences (India)

    Samir Mandal

    2018-02-10

    Feb 10, 2018 ... spectral characteristics due to a free-fall flow and a transonic flow. We notice significant ..... (iii) pressure balance: W+ + + u2. + = W− + − u2. − ... this hot and dense flow controls the high energy spectral characteristic of the ...

  1. Bilateral macular holes in X-linked retinoschisis: Now the spectrum is wider

    Directory of Open Access Journals (Sweden)

    Manoj Gautam

    2011-01-01

    Full Text Available Bilateral occurrence of macular hole in X-linked retinoschisis is an extremely rare event. Spectral domain optical coherence tomography (OCT findings revealed that formation of a macular hole is secondary to the retinoschisis process alone. Bilateral macular holes should be added to the spectrum of X-linked retinoschisis variations and the retinoschisis process alone should be accounted for their formation.

  2. Probing strong-field general relativity near black holes

    CERN Multimedia

    CERN. Geneva; Alvarez-Gaumé, Luís

    2005-01-01

    Nature has sprinkled black holes of various sizes throughout the universe, from stellar mass black holes in X-ray sources to supermassive black holes of billions of solar masses in quasars. Astronomers today are probing the spacetime near black holes using X-rays, and gravitational waves will open a different view in the near future. These tools give us an unprecedented opportunity to test ultra-strong-field general relativity, including the fundamental theorem of the uniqueness of the Kerr metric and Roger Penrose's cosmic censorship conjecture. Already, fascinating studies of spectral lines are showing the extreme gravitational lensing effects near black holes and allowing crude measurements of black hole spin. When the ESA-NASA gravitational wave detector LISA begins its observations in about 10 years, it will make measurements of dynamical spacetimes near black holes with an accuracy greater even than that which theoreticians can reach with their computations today. Most importantly, when gravitational wa...

  3. Cosmic microwave background constraints on primordial black hole dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Aloni, Daniel; Blum, Kfir [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Herzl 234, Rehovot (Israel); Flauger, Raphael, E-mail: daniel.aloni@weizmann.ac.il, E-mail: kfir.blum@weizmann.ac.il, E-mail: flauger@physics.ucsd.edu [University of California, 9500 Gilman Drive 0319, La Jolla, San Diego, CA, 92093 (United States)

    2017-05-01

    We revisit cosmic microwave background (CMB) constraints on primordial black hole dark matter. Spectral distortion limits from COBE/FIRAS do not impose a relevant constraint. Planck CMB anisotropy power spectra imply that primordial black holes with m {sub BH}∼> 5 M {sub ⊙} are disfavored. However, this is susceptible to sizeable uncertainties due to the treatment of the black hole accretion process. These constraints are weaker than those quoted in earlier literature for the same observables.

  4. Unveiling the First Black Holes With JWST:Multi-wavelength Spectral Predictions

    Science.gov (United States)

    Natarajan, Priyamvada; Pacucci, Fabio; Ferrara, Andrea; Agarwal, Bhaskar; Ricarte, Angelo; Zackrisson, Erik; Cappelluti, Nico

    2017-04-01

    Growing supermassive black holes (˜ {10}9 {M}⊙ ) that power luminous z> 6 quasars from light seeds—the remnants of the first stars—within a Gyr of the Big Bang poses a timing challenge. The formation of massive black hole seeds via direct collapse with initial masses ˜ {10}4{--}{10}5 {M}⊙ alleviates this problem. Viable direct-collapse black hole formation sites, the satellite halos of star-forming galaxies, merge and acquire stars to produce a new, transient class of high-redshift objects, obese black hole galaxies (OBGs). The accretion luminosity outshines that of the stars in OBGs. We predict the multi-wavelength energy output of OBGs and growing Pop III remnants at z = 9 for standard and slim disk accretion, as well as high and low metallicities of the associated stellar population. We derive robust selection criteria for OBGs—a pre-selection to eliminate blue sources, followed by color-color cuts ([{F}090W-{F}220W]> 0;-0.3sift out OBGs from other bright, high- and low-redshift contaminants in the infrared. OBGs with predicted {M}{AB}< 25 are unambiguously detectable by the Mid-Infrared Instrument (MIRI), on the upcoming James Webb Space Telescope (JWST). For parameters explored here, growing Pop III remnants with predicted {M}{AB}< 30 will likely be undetectable by JWST. We demonstrate that JWST has the power to discriminate between initial seeding mechanisms.

  5. Foundations of Black Hole Accretion Disk Theory

    Directory of Open Access Journals (Sweden)

    Marek A. Abramowicz

    2013-01-01

    Full Text Available This review covers the main aspects of black hole accretion disk theory. We begin with the view that one of the main goals of the theory is to better understand the nature of black holes themselves. In this light we discuss how accretion disks might reveal some of the unique signatures of strong gravity: the event horizon, the innermost stable circular orbit, and the ergosphere. We then review, from a first-principles perspective, the physical processes at play in accretion disks. This leads us to the four primary accretion disk models that we review: Polish doughnuts (thick disks, Shakura-Sunyaev (thin disks, slim disks, and advection-dominated accretion flows (ADAFs. After presenting the models we discuss issues of stability, oscillations, and jets. Following our review of the analytic work, we take a parallel approach in reviewing numerical studies of black hole accretion disks. We finish with a few select applications that highlight particular astrophysical applications: measurements of black hole mass and spin, black hole vs. neutron star accretion disks, black hole accretion disk spectral states, and quasi-periodic oscillations (QPOs.

  6. Foundations of Black Hole Accretion Disk Theory.

    Science.gov (United States)

    Abramowicz, Marek A; Fragile, P Chris

    2013-01-01

    This review covers the main aspects of black hole accretion disk theory. We begin with the view that one of the main goals of the theory is to better understand the nature of black holes themselves. In this light we discuss how accretion disks might reveal some of the unique signatures of strong gravity: the event horizon, the innermost stable circular orbit, and the ergosphere. We then review, from a first-principles perspective, the physical processes at play in accretion disks. This leads us to the four primary accretion disk models that we review: Polish doughnuts (thick disks), Shakura-Sunyaev (thin) disks, slim disks, and advection-dominated accretion flows (ADAFs). After presenting the models we discuss issues of stability, oscillations, and jets. Following our review of the analytic work, we take a parallel approach in reviewing numerical studies of black hole accretion disks. We finish with a few select applications that highlight particular astrophysical applications: measurements of black hole mass and spin, black hole vs. neutron star accretion disks, black hole accretion disk spectral states, and quasi-periodic oscillations (QPOs).

  7. Rare-earth-doped materials with application to optical signal processing, quantum information science, and medical imaging technology

    Science.gov (United States)

    Cone, R. L.; Thiel, C. W.; Sun, Y.; Böttger, Thomas; Macfarlane, R. M.

    2012-02-01

    Unique spectroscopic properties of isolated rare earth ions in solids offer optical linewidths rivaling those of trapped single atoms and enable a variety of recent applications. We design rare-earth-doped crystals, ceramics, and fibers with persistent or transient "spectral hole" recording properties for applications including high-bandwidth optical signal processing where light and our solids replace the high-bandwidth portion of the electronics; quantum cryptography and information science including the goal of storage and recall of single photons; and medical imaging technology for the 700-900 nm therapeutic window. Ease of optically manipulating rare-earth ions in solids enables capturing complex spectral information in 105 to 108 frequency bins. Combining spatial holography and spectral hole burning provides a capability for processing high-bandwidth RF and optical signals with sub-MHz spectral resolution and bandwidths of tens to hundreds of GHz for applications including range-Doppler radar and high bandwidth RF spectral analysis. Simply stated, one can think of these crystals as holographic recording media capable of distinguishing up to 108 different colors. Ultra-narrow spectral holes also serve as a vibration-insensitive sub-kHz frequency reference for laser frequency stabilization to a part in 1013 over tens of milliseconds. The unusual properties and applications of spectral hole burning of rare earth ions in optical materials are reviewed. Experimental results on the promising Tm3+:LiNbO3 material system are presented and discussed for medical imaging applications. Finally, a new application of these materials as dynamic optical filters for laser noise suppression is discussed along with experimental demonstrations and theoretical modeling of the process.

  8. Temporal resolution requirements of satellite constellations for 30 m global burned area mapping

    Science.gov (United States)

    Melchiorre, A.; Boschetti, L.

    2017-12-01

    Global burned area maps have been generated systematically with daily, coarse resolution satellite data (Giglio et al. 2013). The production of moderate resolution (10 - 30 m) global burned area products would meet the needs of several user communities: improved carbon emission estimations due to heterogeneous landscapes and for local scale air quality and fire management applications (Mouillot et al. 2014; van der Werf et al. 2010). While the increased spatial resolution reduces the influence of mixed burnt/unburnt pixels and it would increase the spectral separation of burned areas, moderate resolution satellites have reduced temporal resolution (10 - 16 days). Fire causes a land-cover change spectrally visible for a period ranging from a few weeks in savannas to over a year in forested ecosystems (Roy et al. 2010); because clouds, smoke, and other optically thick aerosols limit the number of available observations (Roy et al. 2008; Smith and Wooster 2005), burned areas might disappear before they are observed by moderate resolution sensors. Data fusion from a constellation of different sensors has been proposed to overcome these limits (Boschetti et al. 2015; Roy 2015). In this study, we estimated the probability of moderate resolution satellites and virtual constellations (including Landsat-8/9, Sentinel-2A/B) to provide sufficient observations for burned area mapping globally, and by ecosystem. First, we estimated the duration of the persistence of the signal associated with burned areas by combining the MODIS Global Burned Area and the Nadir BRDF-Adjusted Reflectance Product by characterizing the post-fire trends in reflectance to determine the length of the period in which the burn class is spectrally distinct from the unburned and, therefore, detectable. The MODIS-Terra daily cloud data were then used to estimate the probability of cloud cover. The cloud probability was used at each location to estimate the minimum revisit time needed to obtain at least one

  9. Black-hole galactic nuclei: a high-energy perspective

    CERN Document Server

    Boldt, E; Loewenstein, M

    2002-01-01

    The gravitational radiation signals to be anticipated from events involving black-hole galactic nuclei depend on the spin of the underlying object. To obtain evidence about the spin of Seyfert AGN black holes, we can rely on future ultra-high resolution spectral/spatial x-ray studies of iron K line fluorescence from the innermost regions of accreting matter. Normal galaxies present more of a challenge. To account for the highest energy cosmic rays, we propose that ultra-relativistic particle acceleration can occur near the event horizons of spun-up supermassive black-holes at the non-active nuclei of giant elliptical galaxies. This conjecture about the black hole spin associated with such nuclei is subject to verification via the characteristic TeV curvature radiation expected to be detected with upcoming gamma-ray observatories.

  10. BAMS: A Tool for Supervised Burned Area Mapping Using Landsat Data

    Directory of Open Access Journals (Sweden)

    Aitor Bastarrika

    2014-12-01

    Full Text Available A new supervised burned area mapping software named BAMS (Burned Area Mapping Software is presented in this paper. The tool was built from standard ArcGISTM libraries. It computes several of the spectral indexes most commonly used in burned area detection and implements a two-phase supervised strategy to map areas burned between two Landsat multitemporal images. The only input required from the user is the visual delimitation of a few burned areas, from which burned perimeters are extracted. After the discrimination of burned patches, the user can visually assess the results, and iteratively select additional sampling burned areas to improve the extent of the burned patches. The final result of the BAMS program is a polygon vector layer containing three categories: (a burned perimeters, (b unburned areas, and (c non-observed areas. The latter refer to clouds or sensor observation errors. Outputs of the BAMS code meet the requirements of file formats and structure of standard validation protocols. This paper presents the tool’s structure and technical basis. The program has been tested in six areas located in the United States, for various ecosystems and land covers, and then compared against the National Monitoring Trends in Burn Severity (MTBS Burned Area Boundaries Dataset.

  11. Black hole constraints on the running-mass inflation model

    OpenAIRE

    Leach, Samuel M; Grivell, Ian J; Liddle, Andrew R

    2000-01-01

    The running-mass inflation model, which has strong motivation from particle physics, predicts density perturbations whose spectral index is strongly scale-dependent. For a large part of parameter space the spectrum rises sharply to short scales. In this paper we compute the production of primordial black holes, using both analytic and numerical calculation of the density perturbation spectra. Observational constraints from black hole production are shown to exclude a large region of otherwise...

  12. High-accuracy waveforms for binary black hole inspiral, merger, and ringdown

    International Nuclear Information System (INIS)

    Scheel, Mark A.; Boyle, Michael; Chu, Tony; Matthews, Keith D.; Pfeiffer, Harald P.; Kidder, Lawrence E.

    2009-01-01

    The first spectral numerical simulations of 16 orbits, merger, and ringdown of an equal-mass nonspinning binary black hole system are presented. Gravitational waveforms from these simulations have accumulated numerical phase errors through ringdown of f /M=0.951 62±0.000 02, and the final black hole spin is S f /M f 2 =0.686 46±0.000 04.

  13. Inclusion of TCAF model in XSPEC to study accretion flow dynamics around black hole candidates

    Science.gov (United States)

    Debnath, Dipak; Chakrabarti, Sandip Kumar; Mondal, Santanu

    Spectral and Temporal properties of black hole candidates can be well understood with the Chakrabarti-Titarchuk solution of two component advective flow (TCAF). This model requires two accretion rates, namely, the Keplerian disk accretion rate and the sub-Keplerian halo accretion rate, the latter being composed of a low angular momentum flow which may or may not develop a shock. In this solution, the relevant parameter is the relative importance of the halo (which creates the Compton cloud region) rate with respect to the Keplerian disk rate (soft photon source). Though this model has been used earlier to manually fit data of several black hole candidates quite satisfactorily, for the first time we are able to create a user friendly version by implementing additive Table model FITS file into GSFC/NASA's spectral analysis software package XSPEC. This enables any user to extract physical parameters of accretion flows, such as two accretion rates, shock location, shock strength etc. for any black hole candidate. Most importantly, unlike any other theoretical model, we show that TCAF is capable of predicting timing properties from spectral fits, since in TCAF, a shock is responsible for deciding spectral slopes as well as QPO frequencies.

  14. Detection of X-ray spectral state transitions in mini-outbursts of black hole transient GRS 1739-278

    Science.gov (United States)

    Yan, Zhen; Yu, Wenfei

    2017-10-01

    We report the detection of the state transitions and hysteresis effect in the two mini-outbursts of the black hole (BH) transient GRS 1739-278 following its 2014 major outburst. The X-ray spectral evolutions in these two mini-outbursts are similar to the major outburst in spite of their peak luminosities and the outburst durations are one order of magnitude lower. We found L_hard{-to-soft} and Lpeak,soft of the mini-outbursts also follow the correlation previously found in other X-ray binaries. L_hard{-to-soft} of the mini-outbursts is still higher than that of the persistent BH binary Cyg X-1, which supports that there is a link between the maximum luminosity a source can reach in the hard state and the corresponding non-stationary accretion represented by substantial rate of change in the mass accretion rate during flares/outbursts. The detected luminosity range of these two mini-outbursts is roughly in 3.5 × 10-5 to 0.015 (D/7.5 kpc)2(M/8M⊙) LEdd. The X-ray spectra of other BH transients at such low luminosities are usually dominated by a power-law component, and an anti-correlation is observed between the photon index and the X-ray luminosity below 1 per cent LEdd. So, the detection of X-ray spectral state transitions indicates that the accretion flow evolution in these two mini-outbursts of GRS 1739-278 are different from other BH systems at such low-luminosity regime.

  15. Spectral Cauchy Characteristic Extraction: Gravitational Waves and Gauge Free News

    Science.gov (United States)

    Handmer, Casey; Szilagyi, Bela; Winicour, Jeff

    2015-04-01

    We present a fast, accurate spectral algorithm for the characteristic evolution of the full non-linear vacuum Einstein field equations in the Bondi framework. Developed within the Spectral Einstein Code (SpEC), we demonstrate how spectral Cauchy characteristic extraction produces gravitational News without confounding gauge effects. We explain several numerical innovations and demonstrate speed, stability, accuracy, exponential convergence, and consistency with existing methods. We highlight its capability to deliver physical insights in the study of black hole binaries.

  16. INTRASURGICAL MICROSCOPE-INTEGRATED SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY-ASSISTED MEMBRANE PEELING.

    Science.gov (United States)

    Falkner-Radler, Christiane I; Glittenberg, Carl; Gabriel, Max; Binder, Susanne

    2015-10-01

    To evaluate microscope-integrated intrasurgical spectral domain optical coherence tomography during macular surgery in a prospective monocenter study. Before pars plana vitrectomy and before, during, and after membrane peeling, 512 × 128 macular cube scans were performed using a Carl Zeiss Meditec Cirrus high-definition OCT system adapted to the optical pathway of a Zeiss OPMI VISU 200 surgical microscope and compared with retinal staining. The study included 51 patients with epiretinal membranes, with 8 of those having additional lamellar macular holes, 11 patients with vitreomacular traction, and 8 patients with full-thickness macular holes. Intraoperative spectral domain optical coherence tomography allowed performing membrane peeling without using retinal dyes in 40% of cases (28 of 70 patients). No residual membranes were found in 94.3% of patients (66 of 70 patients) in intrasurgical spectral domain optical coherence tomography and subsequent (re)staining. In patients with vitreomacular traction, intrasurgical spectral domain optical coherence tomography scans facilitated decisions on the need for an intraocular tamponade after membrane peeling. Intraoperative spectral domain optical coherence tomography was comparable with retinal dyes in confirming success after membrane peeling. However, the visualization of flat membranes was better after staining.

  17. Bogoliubov Angle, Particle-Hole Mixture and Angular Resolved Photoemission Spectroscopy in Superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Balatsky, A.

    2010-05-04

    Superconducting excitations - Bogoliubov quasiparticles - are the quantum mechanical mixture of negatively charged electron (-e) and positively charged hole (+e). We propose a new observable for Angular Resolved Photoemission Spectroscopy (ARPES) studies that is the manifestation of the particle-hole entanglement of the superconducting quasiparticles. We call this observable a Bogoliubov angle. This angle measures the relative weight of particle and hole amplitude in the superconducting (Bogoliubov) quasiparticle. We show how this quantity can be measured by comparing the ratio of spectral intensities at positive and negative energies.

  18. A Be-type star with a black-hole companion.

    Science.gov (United States)

    Casares, J; Negueruela, I; Ribó, M; Ribas, I; Paredes, J M; Herrero, A; Simón-Díaz, S

    2014-01-16

    Stellar-mass black holes have all been discovered through X-ray emission, which arises from the accretion of gas from their binary companions (this gas is either stripped from low-mass stars or supplied as winds from massive ones). Binary evolution models also predict the existence of black holes accreting from the equatorial envelope of rapidly spinning Be-type stars (stars of the Be type are hot blue irregular variables showing characteristic spectral emission lines of hydrogen). Of the approximately 80 Be X-ray binaries known in the Galaxy, however, only pulsating neutron stars have been found as companions. A black hole was formally allowed as a solution for the companion to the Be star MWC 656 (ref. 5; also known as HD 215227), although that conclusion was based on a single radial velocity curve of the Be star, a mistaken spectral classification and rough estimates of the inclination angle. Here we report observations of an accretion disk line mirroring the orbit of MWC 656. This, together with an improved radial velocity curve of the Be star through fitting sharp Fe II profiles from the equatorial disk, and a refined Be classification (to that of a B1.5-B2 III star), indicates that a black hole of 3.8 to 6.9 solar masses orbits MWC 656, the candidate counterpart of the γ-ray source AGL J2241+4454 (refs 5, 6). The black hole is X-ray quiescent and fed by a radiatively inefficient accretion flow giving a luminosity less than 1.6 × 10(-7) times the Eddington luminosity. This implies that Be binaries with black-hole companions are difficult to detect in conventional X-ray surveys.

  19. Calculating the mass fraction of primordial black holes

    International Nuclear Information System (INIS)

    Young, Sam; Byrnes, Christian T.; Sasaki, Misao

    2014-01-01

    We reinspect the calculation for the mass fraction of primordial black holes (PBHs) which are formed from primordial perturbations, finding that performing the calculation using the comoving curvature perturbation R c in the standard way vastly overestimates the number of PBHs, by many orders of magnitude. This is because PBHs form shortly after horizon entry, meaning modes significantly larger than the PBH are unobservable and should not affect whether a PBH forms or not—this important effect is not taken into account by smoothing the distribution in the standard fashion. We discuss alternative methods and argue that the density contrast, Δ, should be used instead as super-horizon modes are damped by a factor k 2 . We make a comparison between using a Press-Schechter approach and peaks theory, finding that the two are in close agreement in the region of interest. We also investigate the effect of varying the spectral index, and the running of the spectral index, on the abundance of primordial black holes

  20. Dynamical Black Hole Masses of BL Lac Objects from the Sloan Digital Sky Survey

    NARCIS (Netherlands)

    Plotkin, Richard M.; Markoff, Sera; Trager, Scott C.; Anderson, Scott F.

    2012-01-01

    We measure black hole masses for 71 BL Lac objects from the Sloan Digital Sky Survey (SDSS) with redshifts out to z ∼ 0.4. We perform spectral decompositions of their nuclei from their host galaxies and measure their stellar velocity dispersions. Black hole masses are then derived from the black

  1. Hole-Size Increasing PCFs for Blue-Extended Supercontinuum Generation

    DEFF Research Database (Denmark)

    Sørensen, Simon Toft; Larsen, Casper; Jakobsen, C.

    2013-01-01

    into the deep-blue in a single mode PCF with varying hole-size and pitch fabricated directly at the draw-tower. The PCFs in this work are fabricated by increasing the pressure on the air holes during the drawing. However, this process alone will lead to an undesirable structure where both the relative hole......Supercontinuum (SC) sources with spectra extending into the deep-blue region below 400 nm are highly desirable in areas such as fluorescent microscopy [1]. Tapering of photonic crystal fibers (PCFs) with high air-fill fractions has proven an effective way of extending the spectra into the deep...... wavelength spectral edge to wavelengths in the deep-blue or even UV. Previous reports on blue-extended SC generation were typically achieved in tapered PCFs where the air-hole structure was preserved [1-4], i.e. the relative hole-size constant. However, such PCFs with high air-fill fractions are inevitably...

  2. Ultrafast Holographic Image Recording by Single Shot Femtosecond Spectral Hole Burning

    National Research Council Canada - National Science Library

    Rebane, Aleksander

    2001-01-01

    .... This allowed us to record image holograms with 150-fs duration pulses without need to accumulate the SHB effect from many exposures. Results of this research show that it is possible to perform optical recording of data in frequency-domain on ultrafast time scale. These results can be used also as a new diagnostic tool for femtosecond dynamics in various ultrafast optical interactions.

  3. Spectrally accurate initial data in numerical relativity

    Science.gov (United States)

    Battista, Nicholas A.

    Einstein's theory of general relativity has radically altered the way in which we perceive the universe. His breakthrough was to realize that the fabric of space is deformable in the presence of mass, and that space and time are linked into a continuum. Much evidence has been gathered in support of general relativity over the decades. Some of the indirect evidence for GR includes the phenomenon of gravitational lensing, the anomalous perihelion of mercury, and the gravitational redshift. One of the most striking predictions of GR, that has not yet been confirmed, is the existence of gravitational waves. The primary source of gravitational waves in the universe is thought to be produced during the merger of binary black hole systems, or by binary neutron stars. The starting point for computer simulations of black hole mergers requires highly accurate initial data for the space-time metric and for the curvature. The equations describing the initial space-time around the black hole(s) are non-linear, elliptic partial differential equations (PDE). We will discuss how to use a pseudo-spectral (collocation) method to calculate the initial puncture data corresponding to single black hole and binary black hole systems.

  4. Ultrafast Spectroscopy of Semiconductor Devices

    DEFF Research Database (Denmark)

    Borri, Paola; Langbein, Wolfgang; Hvam, Jørn Marcher

    1999-01-01

    In this work we present an experimental technique for investigating ultrafast carrier dynamics in semiconductor optical amplifiers at room temperature. These dynamics, influenced by carrier heating, spectral hole-burning and two-photon absorption, are very important for device applications in inf...

  5. VHTR-fuel irradiation capsules for VT-1 hole of JRR-2

    International Nuclear Information System (INIS)

    Kikuchi, Teruo; Kikuchi, Akira; Tobita, Tsutomu; Kashimura, Satoru; Miyasaka, Yasuhiko

    1977-02-01

    Irradiations of VHTR fuels were made in the VT-1 irradiation hole of JRR-2. Three capsules, VP-1, VP-2 and VP-4, which contained fuel compacts, were irradiated for 300 hr at temperatures of 950 0 , 1370 0 and 1500 0 C up to the estimated burn-ups of 0.74, 0.87 and 0.80%FIMA, respectively. And, to study the amoeba effect of fuel particles, two capsules, VP-3 and VP-5, were irradiated for 300 hr at temperatures of 1650 0 and 1670 0 C up to the estimated burn-ups of 0.38 and 0.33%FIMA, respectively. (auth.)

  6. Constraining Absorption of Organic Aerosol from Biomass Burning with Observations

    Science.gov (United States)

    Feng, Y.; Liu, X.

    2014-12-01

    Biomass burning emissions contribute to a large fraction of global organic aerosol (OA) emissions. In most models, radiative forcing of black carbon (BC) and OA from biomass burning offsets each other to give a small or close to zero total forcing, i.e., an estimate of 0 (-0.2 to +0.2) W m-2 by IPCC-AR5. Recent observational and modeling studies have shown the absorbing part of OA, referred to as "brown" carbon (BrC), to be a significant source of direct absorption of solar radiation thus positive forcing, in particular over regions dominated by biomass burning and biofuel emissions. Here we implement optical treatment for the BrC absorption in the CESM1/CAM5 model, and compare the calculated aerosol spectral absorption with ground-based AERONET and DOE/ARM observations. In this version of CAM5, biomass burning and biofuel OA are treated separately from fossil fuel OA with different imaginary refractive index. Because the absorption of BrC is highly variable and uncertain depending on source, aging, and mixing state, sensitivity studies of BrC refractive index parameterized by fuel type and ratio of BC to OA mass will be examined and the resulting uncertainty in the estimated forcing will be discussed. Preliminary results suggest the simulated wavelength dependence of aerosol absorption, as measured by the absorption Ångström exponent (AAE), increases from 0.9 for non-absorbing OA to 1.2 (or 1.0) for strongly (or moderately) absorbing BrC. The AAE calculated for the strongly absorbing BrC agrees with AERONET spectral observations at 440-870 nm over most regions but overpredicts for the open biomass burning-dominated South America and southern Africa, in which inclusion of moderately absorbing BrC exhibits better agreement.

  7. Combination of Landsat and Sentinel-2 MSI data for initial assessing of burn severity

    Science.gov (United States)

    Quintano, C.; Fernández-Manso, A.; Fernández-Manso, O.

    2018-02-01

    Nowadays Earth observation satellites, in particular Landsat, provide a valuable help to forest managers in post-fire operations; being the base of post-fire damage maps that enable to analyze fire impacts and to develop vegetation recovery plans. Sentinel-2A MultiSpectral Instrument (MSI) records data in similar spectral wavelengths that Landsat 8 Operational Land Imager (OLI), and has higher spatial and temporal resolutions. This work compares two types of satellite-based maps for evaluating fire damage in a large wildfire (around 8000 ha) located in Sierra de Gata (central-western Spain) on 6-11 August 2015. 1) burn severity maps based exclusively on Landsat data; specifically, on differenced Normalized Burn Ratio (dNBR) and on its relative versions (Relative dNBR, RdNBR, and Relativized Burn Ratio, RBR) and 2) burn severity maps based on the same indexes but combining pre-fire data from Landsat 8 OLI with post-fire data from Sentinel-2A MSI data. Combination of both Landsat and Sentinel-2 data might reduce the time elapsed since forest fire to the availability of an initial fire damage map. Interpretation of ortho-photograph Pléiades 1 B data (1:10,000) provided us the ground reference data to measure the accuracy of both burn severity maps. Results showed that Landsat based burn severity maps presented an adequate assessment of the damage grade (κ statistic = 0.80) and its spatial distribution in wildfire emergency response. Further using both Landsat and Sentinel-2 MSI data the accuracy of burn severity maps, though slightly lower (κ statistic = 0.70) showed an adequate level for be used by forest managers.

  8. THE X-RAY POWER SPECTRAL DENSITY FUNCTION AND BLACK HOLE MASS ESTIMATE FOR THE SEYFERT ACTIVE GALACTIC NUCLEUS IC 4329a

    International Nuclear Information System (INIS)

    Markowitz, A.

    2009-01-01

    We present the X-ray broadband power spectral density function (PSD) of the X-ray-luminous Seyfert IC 4329a, constructed from light curves obtained via Rossi X-ray Timing Explorer monitoring and an XMM-Newton observation. Modeling the 3-10 keV PSD using a broken power-law PSD shape, a break in power-law slope is significantly detected at a temporal frequency of 2.5 +2.5 -1.7 x 10 -6 Hz, which corresponds to a PSD break timescale T b of 4.6 +10.1 -2.3 days. Using the relation between T b , black hole mass M BH , and bolometric luminosity as quantified by McHardy and coworkers, we infer a black hole mass estimate of M BH = 1.3 +1.0 -0.3 x 10 8 M sun and an accretion rate relative to Eddington of 0.21 +0.06 -0.10 for this source. Our estimate of M BH is consistent with other estimates, including that derived by the relation between M BH and stellar velocity dispersion. We also present PSDs for the 10-20 and 20-40 keV bands; they lack sufficient temporal frequency coverage to reveal a significant break, but are consistent with the same PSD shape and break frequency as in the 3-10 keV band.

  9. Numerical investigations on the performance of external-cavity mode-locked semiconductor lasers

    DEFF Research Database (Denmark)

    Mulet, Josep; Mørk, Jesper

    2004-01-01

    The performance of an external-cavity mode-locked semiconductor laser is analyzed theoretically and numerically. Passive mode-locking is described using a fully-distributed time-domain model including fast effects, spectral hole burning and carrier heating. We provide optimization rules in order ...

  10. Spectral properties of a V-type three-level atom driven by two bichromatic fields

    International Nuclear Information System (INIS)

    Li Peng; Nakajima, Takashi; Ning Xijing

    2006-01-01

    We theoretically investigate the spectral properties of a V-type three-level atom driven by two bichromatic fields with a common frequency difference. By decomposing the master equation using harmonic expansions and invoking quantum regression theorem, fluorescence and probe absorption spectra of the strong atomic transition are numerically calculated under the steady state condition. We find that both fluorescence and absorption spectra exhibit two interesting features, which are equidistant comblike structures and phase-dependent line splittings. In the comblike structures, each fluorescence peak can be made subnatural by manipulating the relative intensities of the coupling fields, while for the absorption lines only the central peak can be narrowed. Line splittings are induced by the relative phase delay between the envelopes of the amplitudes of the two bichromatic fields. Interestingly, we find that the manipulation of the relative phase delay results in the emergence of sharp subnatural dips in the absorption spectra. As a natural consequence of the subnatural absorption dips, absorption spectra in atomic vapors exhibit striking subnatural burning holes for the counterpropagating probe beam geometry

  11. The Nature of Accreting Black Holes in Nearby Galaxy Nuclei

    Science.gov (United States)

    Colbert, E. J. M.; Mushotzky, R. F.

    1999-05-01

    We have found compact X-ray sources in the center of 21 (54%) of 39 nearby face-on spiral and elliptical galaxies with available ROSAT HRI data. ROSAT X-ray luminosities (0.2 - 2.4 keV) of these compact X-ray sources are ~ 10(37) -10(40) erg s(-1) (with a mean of 3 x 10(39) erg s(-1) ). The mean displacement between the location of the compact X-ray source and the optical photometric center of the galaxy is ~ 390 pc. The fact that compact nuclear sources were found in nearly all (five of six) galaxies with previous evidence for a black hole or an AGN indicates that at least some of the X-ray sources are accreting supermassive black holes. ASCA spectra of six of the 21 galaxies show the presence of a hard component with relatively steep (Gamma ~ 2.5) spectral slope. A multicolor disk blackbody model fits the data from the spiral galaxies well, suggesting that the X-ray object in these galaxies may be similar to a Black Hole Candidate in its soft (high) state. ASCA data from the elliptical galaxies indicate that hot (kT ~ 0.7 keV) gas dominates the emission. The fact that (for both spiral and elliptical galaxies) the spectral slope is steeper than in normal type 1 AGNs and that relatively low absorbing columns (N_H ~ 10(21) cm(-2) ) were found to the power-law component indicates that these objects are somehow geometrically and/or physically different from AGNs in normal active galaxies. The X-ray sources in the spiral and elliptical galaxies may be black hole X-ray binaries, low-luminosity AGNs, or possibly young X-ray luminous supernovae. Assuming the sources in the spiral galaxies are accreting black holes in their soft state, we estimate black hole masses ~ 10(2) -10(4) M_sun.

  12. Modeling Fire Severity in Black Spruce Stands in the Alaskan Boreal Forest Using Spectral and Non-Spectral Geospatial Data

    Science.gov (United States)

    Barrett, K.; Kasischke, E. S.; McGuire, A. D.; Turetsky, M. R.; Kane, E. S.

    2010-01-01

    Biomass burning in the Alaskan interior is already a major disturbance and source of carbon emissions, and is likely to increase in response to the warming and drying predicted for the future climate. In addition to quantifying changes to the spatial and temporal patterns of burned areas, observing variations in severity is the key to studying the impact of changes to the fire regime on carbon cycling, energy budgets, and post-fire succession. Remote sensing indices of fire severity have not consistently been well-correlated with in situ observations of important severity characteristics in Alaskan black spruce stands, including depth of burning of the surface organic layer. The incorporation of ancillary data such as in situ observations and GIS layers with spectral data from Landsat TM/ETM+ greatly improved efforts to map the reduction of the organic layer in burned black spruce stands. Using a regression tree approach, the R2 of the organic layer depth reduction models was 0.60 and 0.55 (pb0.01) for relative and absolute depth reduction, respectively. All of the independent variables used by the regression tree to estimate burn depth can be obtained independently of field observations. Implementation of a gradient boosting algorithm improved the R2 to 0.80 and 0.79 (pb0.01) for absolute and relative organic layer depth reduction, respectively. Independent variables used in the regression tree model of burn depth included topographic position, remote sensing indices related to soil and vegetation characteristics, timing of the fire event, and meteorological data. Post-fire organic layer depth characteristics are determined for a large (N200,000 ha) fire to identify areas that are potentially vulnerable to a shift in post-fire succession. This application showed that 12% of this fire event experienced fire severe enough to support a change in post-fire succession. We conclude that non-parametric models and ancillary data are useful in the modeling of the surface

  13. Exploring Black Hole Accretion in Active Galactic Nuclei with Simbol-X

    Science.gov (United States)

    Goosmann, R. W.; Dovčiak, M.; Mouchet, M.; Czerny, B.; Karas, V.; Gonçalves, A.

    2009-05-01

    A major goal of the Simbol-X mission is to improve our knowledge about black hole accretion. By opening up the X-ray window above 10 keV with unprecedented sensitivity and resolution we obtain new constraints on the X-ray spectral and variability properties of active galactic nuclei. To interpret the future data, detailed X-ray modeling of the dynamics and radiation processes in the black hole vicinity is required. Relativistic effects must be taken into account, which then allow to constrain the fundamental black hole parameters and the emission pattern of the accretion disk from the spectra that will be obtained with Simbol-X.

  14. Improving burn care and preventing burns by establishing a burn database in Ukraine.

    Science.gov (United States)

    Fuzaylov, Gennadiy; Murthy, Sushila; Dunaev, Alexander; Savchyn, Vasyl; Knittel, Justin; Zabolotina, Olga; Dylewski, Maggie L; Driscoll, Daniel N

    2014-08-01

    Burns are a challenge for trauma care and a contribution to the surgical burden. The former Soviet republic of Ukraine has a foundation for burn care; however data concerning burns in Ukraine has historically been scant. The objective of this paper was to compare a new burn database to identify problems and implement improvements in burn care and prevention in this country. Retrospective analyses of demographic and clinical data of burn patients including Tukey's post hoc test, analysis of variance, and chi square analyses, and Fisher's exact test were used. Data were compared to the American Burn Association (ABA) burn repository. This study included 1752 thermally injured patients treated in 20 hospitals including Specialized Burn Unit in Municipal Hospital #8 Lviv, Lviv province in Ukraine. Scald burns were the primary etiology of burns injuries (70%) and burns were more common among children less than five years of age (34%). Length of stay, mechanical ventilation use, infection rates, and morbidity increased with greater burn size. Mortality was significantly related to burn size, inhalation injury, age, and length of stay. Wound infections were associated with burn size and older age. Compared to ABA data, Ukrainian patients had double the length of stay and a higher rate of wound infections (16% vs. 2.4%). We created one of the first burn databases from a region of the former Soviet Union in an effort to bring attention to burn injury and improve burn care. Copyright © 2013 Elsevier Ltd and ISBI. All rights reserved.

  15. Vegetation burn severity mapping using Landsat-8 and WorldView-2

    Science.gov (United States)

    Wu, Zhuoting; Middleton, Barry R.; Hetzler, Robert; Vogel, John M.; Dye, Dennis G.

    2015-01-01

    We used remotely sensed data from the Landsat-8 and WorldView-2 satellites to estimate vegetation burn severity of the Creek Fire on the San Carlos Apache Reservation, where wildfire occurrences affect the Tribe's crucial livestock and logging industries. Accurate pre- and post-fire canopy maps at high (0.5-meter) resolution were created from World- View-2 data to generate canopy loss maps, and multiple indices from pre- and post-fire Landsat-8 images were used to evaluate vegetation burn severity. Normalized difference vegetation index based vegetation burn severity map had the highest correlation coefficients with canopy loss map from WorldView-2. Two distinct approaches - canopy loss mapping from WorldView-2 and spectral index differencing from Landsat-8 - agreed well with the field-based burn severity estimates and are both effective for vegetation burn severity mapping. Canopy loss maps created with WorldView-2 imagery add to a short list of accurate vegetation burn severity mapping techniques that can help guide effective management of forest resources on the San Carlos Apache Reservation, and the broader fire-prone regions of the Southwest.

  16. Histopathological detection of entry and exit holes in human skin wounds caused by firearms.

    Science.gov (United States)

    Baptista, Marcus Vinícius; d'Ávila, Solange C G P; d'Ávila, Antônio Miguel M P

    2014-07-01

    The judiciary needs forensic medicine to determine the difference between an entry hole and an exit hole in human skin caused by firearms for civilian use. This important information would be most useful if a practical and accurate method could be done with low-cost and minimal technological resources. Both macroscopic and microscopic analyses were performed on skin lesions caused by firearm projectiles, to establish histological features of 14 entry holes and 14 exit holes. Microscopically, in the abrasion area macroscopically observed, there were signs of burns (sub-epidermal cracks and keratinocyte necrosis) in the entrance holes in all cases. These signs were not found in three exit holes which showed an abrasion collar, nor in other exit holes. Some other microscopic features not found in every case were limited either to entry holes, such as cotton fibres, grease deposits, or tattooing in the dermis, or to exit holes, such as adipose tissue, bone or muscle tissue in the dermis. Coagulative necrosis of keratinocytes and sub-epidermal cracks are characteristic of entry holes. Despite the small sample size, it can be safely inferred that this is an important microscopic finding, among others less consistently found, to define an entry hole in questionable cases. Copyright © 2014 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  17. Calculating the mass fraction of primordial black holes

    Energy Technology Data Exchange (ETDEWEB)

    Young, Sam; Byrnes, Christian T. [Department of Physics and Astronomy, University of Sussex, North-South Road, Brighton (United Kingdom); Sasaki, Misao, E-mail: sy81@sussex.ac.uk, E-mail: ctb22@sussex.ac.uk, E-mail: misao@yukawa.kyoto-u.ac.jp [Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan)

    2014-07-01

    We reinspect the calculation for the mass fraction of primordial black holes (PBHs) which are formed from primordial perturbations, finding that performing the calculation using the comoving curvature perturbation R{sub c} in the standard way vastly overestimates the number of PBHs, by many orders of magnitude. This is because PBHs form shortly after horizon entry, meaning modes significantly larger than the PBH are unobservable and should not affect whether a PBH forms or not—this important effect is not taken into account by smoothing the distribution in the standard fashion. We discuss alternative methods and argue that the density contrast, Δ, should be used instead as super-horizon modes are damped by a factor k{sup 2}. We make a comparison between using a Press-Schechter approach and peaks theory, finding that the two are in close agreement in the region of interest. We also investigate the effect of varying the spectral index, and the running of the spectral index, on the abundance of primordial black holes.

  18. High-energy observations of the state transition of the X-ray nova and black hole candidate XTE J1720-318

    DEFF Research Database (Denmark)

    Bel, M.C.; Rodriguez, J.; Sizun, P.

    2004-01-01

    We report the results of extensive high-energy observations of the X-ray transient and black hole candidate XTE J1720-318 performed with INTEGRAL, XMM-Newton and RXTE. The source, which underwent an X-ray outburst in 2003 January, was observed in February in a spectral state dominated by a soft......, typical of a black-hole binary in the so-called High/Soft State. We then followed the evolution of the source outburst over several months using the INTEGRAL Galactic Centre survey observations. The source became active again at the end of March: it showed a clear transition towards a much harder state...... of the black hole X-ray novae class which populate our galactic bulge and we discuss its properties in the frame of the spectral models used for transient black hole binaries....

  19. Diffraction of stochastic electromagnetic fields by a hole in a thin film with real optical properties

    Science.gov (United States)

    Dorofeyev, Illarion

    2008-08-01

    The classical Kirchhoff theory of diffraction is extended to the case of real optical properties of a screen and its finite thickness. A spectral power density of diffracted electromagnetic fields by a hole in a thin film with real optical properties was calculated. The problem was solved by use of the vector Green theorems and related Green function of the boundary value problem. A spectral and spatial selectivity of the considered system was demonstrated. Diffracted patterns were calculated for the coherent and incoherent incident fields in case of holes array in a screen of perfect conductivity.

  20. Diffraction of stochastic electromagnetic fields by a hole in a thin film with real optical properties

    International Nuclear Information System (INIS)

    Dorofeyev, Illarion

    2008-01-01

    The classical Kirchhoff theory of diffraction is extended to the case of real optical properties of a screen and its finite thickness. A spectral power density of diffracted electromagnetic fields by a hole in a thin film with real optical properties was calculated. The problem was solved by use of the vector Green theorems and related Green function of the boundary value problem. A spectral and spatial selectivity of the considered system was demonstrated. Diffracted patterns were calculated for the coherent and incoherent incident fields in case of holes array in a screen of perfect conductivity

  1. Black/white hole radiation from dispersive theories

    International Nuclear Information System (INIS)

    Macher, Jean; Parentani, Renaud

    2009-01-01

    We study the fluxes emitted by black holes when using dispersive field theories. We work with stationary one-dimensional backgrounds which are asymptotically flat on both sides of the horizon. The asymptotic fluxes are governed by a 3x3 Bogoliubov transformation. The fluxes emitted by the corresponding white holes are regular and governed by the inverse transformation. We numerically compute the spectral properties of these fluxes for both sub- and superluminal quartic dispersion. The leading deviations with respect to the dispersionless flux are computed and shown to be governed by a critical frequency above which there is no radiation. Unlike the UV scale governing dispersion, its value critically depends on the asymptotic properties of the background. We also study the flux outside the robust regime. In particular we show that its low-frequency part remains almost thermal but with a temperature which significantly differs from the standard one. Applications to four-dimensional black holes and Bose-Einstein condensates are in preparation.

  2. Polarized Gamma-Ray Emission from the Galactic Black Hole Cygnus X-1

    Science.gov (United States)

    Laurent, P.; Rodriquez, J.; Wilms, J.; Bel, M. Cadolle; Pottschmidt, K.; Grinberg, V.

    2011-01-01

    Because of their inherently high flux allowing the detection of clear signals, black hole X-ray binaries are interesting candidates for polarization studies, even if no polarization signals have been observed from them before. Such measurements would provide further detailed insight into these sources' emission mechanisms. We measured the polarization of the gamma-ray emission from the black hole binary system Cygnus X-I with the INTEGRAL/IBIS telescope. Spectral modeling ofthe data reveals two emission mechanisms: The 250-400 keY data are consistent with emission dominated by Compton scattering on thermal electrons and are weakly polarized. The second spectral component seen in the 400keV-2MeV band is by contrast strongly polarized, revealing that the MeV emission is probably related to the jet first detected in the radio band.

  3. RIO: a new computational framework for accurate initial data of binary black holes

    Science.gov (United States)

    Barreto, W.; Clemente, P. C. M.; de Oliveira, H. P.; Rodriguez-Mueller, B.

    2018-06-01

    We present a computational framework ( Rio) in the ADM 3+1 approach for numerical relativity. This work enables us to carry out high resolution calculations for initial data of two arbitrary black holes. We use the transverse conformal treatment, the Bowen-York and the puncture methods. For the numerical solution of the Hamiltonian constraint we use the domain decomposition and the spectral decomposition of Galerkin-Collocation. The nonlinear numerical code solves the set of equations for the spectral modes using the standard Newton-Raphson method, LU decomposition and Gaussian quadratures. We show the convergence of the Rio code. This code allows for easy deployment of large calculations. We show how the spin of one of the black holes is manifest in the conformal factor.

  4. A Method of Mapping Burned Area Using Chinese FengYun-3 MERSI Satellite Data

    Science.gov (United States)

    Shan, T.

    2017-12-01

    Wildfire is a naturally reoccurring global phenomenon which has environmental and ecological consequences such as effects on the global carbon budget, changes to the global carbon cycle and disruption to ecosystem succession. The information of burned area is significant for post disaster assessment, ecosystems protection and restoration. The Medium Resolution Spectral Imager (MERSI) onboard FENGYUN-3C (FY-3C) has shown good ability for fire detection and monitoring but lacks recognition among researchers. In this study, an automated burned area mapping algorithm was proposed based on FY-3C MERSI data. The algorithm is generally divided into two phases: 1) selection of training pixels based on 1000-m resolution MERSI data, which offers more spectral information through the use of more vegetation indices; and 2) classification: first the region growing method is applied to 1000-m MERSI data to calculate the core burned area and then the same classification method is applied to the 250-m MERSI data set by using the core burned area as a seed to obtain results at a finer spatial resolution. An evaluation of the performance of the algorithm was carried out at two study sites in America and Canada. The accuracy assessment and validation were made by comparing our results with reference results derived from Landsat OLI data. The result has a high kappa coefficient and the lower commission error, indicating that this algorithm can improve the burned area mapping accuracy at the two study sites. It may then be possible to use MERSI and other data to fill the gaps in the imaging of burned areas in the future.

  5. Preliminary report on NTS spectral gamma logging and calibration models

    International Nuclear Information System (INIS)

    Mathews, M.A.; Warren, R.G.; Garcia, S.R.; Lavelle, M.J.

    1985-01-01

    Facilities are now available at the Nevada Test Site (NTS) in Building 2201 to calibrate spectral gamma logging equipment in environments of low radioactivity. Such environments are routinely encountered during logging of holes at the NTS. Four calibration models were delivered to Building 2201 in January 1985. Each model, or test pit, consists of a stone block with a 12-inch diameter cored borehole. Preliminary radioelement values from the core for the test pits range from 0.58 to 3.83% potassium (K), 0.48 to 29.11 ppm thorium (Th), and 0.62 to 40.42 ppm uranium (U). Two satellite holes, U19ab number2 and U19ab number3, were logged during the winter of 1984-1985. The response of these logs correlates with contents of the naturally radioactive elements K. Th. and U determined in samples from petrologic zones that occur within these holes. Based on these comparisons, the spectral gamma log aids in the recognition and mapping of subsurface stratigraphic units and alteration features associated with unusual concentration of these radioactive elements, such as clay-rich zones

  6. Use of neutron capture gamma radiation for determining grade of iron ore in blast holes and exploration holes

    International Nuclear Information System (INIS)

    Eisler, P.L.; Huppert, P.; Mathew, P.J.; Wylie, A.W.; Youl, S.F.

    1977-01-01

    Neutron radiative capture and neutron-neutron logging have been applied to determining the grade of ore in dry blast holes and a dry exploration hole drilled into a layered iron deposit. Both thermal and epithermal neutron responses were measured as well as the gamma-ray responses due to neutron capture by iron and by hydrogen present in hydrated minerals. The results were fitted by a stepwise multiple linear regression technique to give expressions for mean grade of ore in the drill hole and 95% confidence intervals for estimation of this mean. For an overall range of ore grades of 20-68% Fe and a mean grade of 63% Fe, the confidence interval for prediction of mean grade for the neutron-gamma technique was 0.3% Fe for pooled data from all five blast holes and 0.8% Fe for a single hole. It was also shown that for this type of layered deposit a simpler neutron-neutron log incorporating simultaneous measurement of both thermal and epithermal neutron responses gave almost as good a grade prediction result for pooled results from five drill holes, namely 63+-0.4% Fe, as that obtained by the neutron-gamma technique. The results of both types of log are compared with those obtained by the spectral gamma-ray backscattering [Psub(z)] technique, or by logging of natural gamma radiations from the shale component of the ore. From this comparison conclusions are drawn regarding the most suitable technique to employ for determining grade of iron ore in various practical logging situations. (author)

  7. Ocriplasmin for treatment of stage 2 macular holes: early clinical results.

    Science.gov (United States)

    Miller, John B; Kim, Leo A; Wu, David M; Vavvas, Demetrios G; Eliott, Dean; Husain, Deeba

    2014-01-01

    To review clinical and structural outcomes of ocriplasmin for treatment of stage 2 macular holes. A retrospective review of the first patients with stage 2 macular holes to be treated with ocriplasmin at Massachusetts Eye and Ear Infirmary. All patients were imaged with spectral-domain optical coherence tomography (SD-OCT). Eight patients with stage 2 macular holes received a single injection of 125 μg of ocriplasmin. One patient (12.5%) demonstrated macular hole closure. The posterior hyaloid separated from the macula in six eyes (75%). All seven holes that remained open showed enlargement in hole diameters (narrowest, apical, and basal) at 1 week and 1 month. All seven were successfully closed with surgery. Ellipsoid zone disruptions were observed by OCT in four eyes (50%) and persisted throughout follow-up (more than 6 months on average). In early clinical results, the authors found a lower macular hole closure rate with ocriplasmin than previously reported. Enlargement was observed in all holes that failed to close with ocriplasmin. The authors found ellipsoid zone disruptions that persisted through 6 months of follow-up after ocriplasmin injection. Further work is needed to investigate the cause for these ellipsoid zone changes. Copyright 2014, SLACK Incorporated.

  8. Impacts of Brown Carbon from Biomass Burning on Surface UV and Ozone Photochemistry in the Amazon Basin

    Science.gov (United States)

    Mok, Jungbin; Krotkov, Nickolay A.; Arola, Antti; Torres, Omar; Jethva, Hiren; Andrade, Marcos; Labow, Gordon; Eck, Thomas F.; Li, Zhangqing; Dickerson, Russell R.; hide

    2016-01-01

    The spectral dependence of light absorption by atmospheric particulate matter has major implications for air quality and climate forcing, but remains uncertain especially in tropical areas with extensive biomass burning. In the September-October 2007 biomass-burning season in Santa Cruz, Bolivia, we studied light absorbing (chromophoric) organic or brown carbon (BrC) with surface and space-based remote sensing. We found that BrC has negligible absorption at visible wavelengths, but significant absorption and strong spectral dependence at UV wavelengths. Using the ground-based inversion of column effective imaginary refractive index in the range 305368nm, we quantified a strong spectral dependence of absorption by BrC in the UV and diminished ultraviolet B (UV-B) radiation reaching the surface. Reduced UV-B means less erythema, plant damage, and slower photolysis rates. We use a photochemical box model to show that relative to black carbon (BC) alone, the combined optical properties of BrC and BC slow the net rate of production of ozone by up to 18 and lead to reduced concentrations of radicals OH, HO2, and RO2 by up to 17, 15, and 14, respectively. The optical properties of BrC aerosol change in subtle ways the generally adverse effects of smoke from biomass burning.

  9. Impacts of brown carbon from biomass burning on surface UV and ozone photochemistry in the Amazon Basin

    KAUST Repository

    Mok, Jungbin

    2016-11-11

    The spectral dependence of light absorption by atmospheric particulate matter has major implications for air quality and climate forcing, but remains uncertain especially in tropical areas with extensive biomass burning. In the September-October 2007 biomass-burning season in Santa Cruz, Bolivia, we studied light absorbing (chromophoric) organic or “brown” carbon (BrC) with surface and space-based remote sensing. We found that BrC has negligible absorption at visible wavelengths, but significant absorption and strong spectral dependence at UV wavelengths. Using the ground-based inversion of column effective imaginary refractive index in the range 305–368 nm, we quantified a strong spectral dependence of absorption by BrC in the UV and diminished ultraviolet B (UV-B) radiation reaching the surface. Reduced UV-B means less erythema, plant damage, and slower photolysis rates. We use a photochemical box model to show that relative to black carbon (BC) alone, the combined optical properties of BrC and BC slow the net rate of production of ozone by up to 18% and lead to reduced concentrations of radicals OH, HO2, and RO2 by up to 17%, 15%, and 14%, respectively. The optical properties of BrC aerosol change in subtle ways the generally adverse effects of smoke from biomass burning.

  10. Spectral properties of doped bilayer cuprates at finite temperatures

    Indian Academy of Sciences (India)

    teresting results. For the overdoped samples, these results show a splitting of electronic states near ... self-consistent perturbation approach is used to calculate the electronic spectral function for differ- ent values of hole .... Council for Scientific and Industrial Research (CSIR), Government of India, for financial support via ...

  11. Different X-ray spectral evolution for black hole X-ray binaries in dual tracks of radio-X-ray correlation

    International Nuclear Information System (INIS)

    Cao, Xiao-Feng; Wu, Qingwen; Dong, Ai-Jun

    2014-01-01

    Recently, an 'outlier' track of radio-X-ray correlation was found, which is much steeper than the former universal correlation, where dual tracks were speculated to be triggered by different accretion processes. In this work, we test this issue by exploring hard X-ray spectral evolution in four black-hole X-ray binaries with multiple, quasi-simultaneous radio and X-ray observations. First, we find that hard X-ray photon indices, Γ, are negatively and positively correlated with X-ray fluxes when the X-ray flux, F 3-9 keV , is below and above a critical flux, F X, crit , which are consistent with predictions of the advection-dominated accretion flow and the disk-corona model, respectively. Second, and most importantly, we find that the radio-X-ray correlations are also clearly different when the X-ray fluxes are higher and lower than the critical flux as defined by X-ray spectral evolution. The data points with F 3-9 keV ≳ F X, crit have a steeper radio-X-ray correlation (F X ∝F R b and b ∼ 1.1-1.4), which roughly forms the ''outlier'' track. However, the data points with anti-correlation of Γ – F 3-9 keV either stay in the universal track with b ∼ 0.61 or stay in the transition track (from the universal to 'outlier' tracks or vice versa). Therefore, our results support that the universal and ''outlier'' tracks of radio-X-ray correlations are regulated by radiatively inefficient and radiatively efficient accretion model, respectively.

  12. Verifying black hole orbits with gravitational spectroscopy

    International Nuclear Information System (INIS)

    Drasco, Steve

    2009-01-01

    Gravitational waves from test masses bound to geodesic orbits of rotating black holes are simulated, using Teukolsky's black hole perturbation formalism, for about ten thousand generic orbital configurations. Each binary radiates power exclusively in modes with frequencies that are integer-linear combinations of the orbit's three fundamental frequencies. General spectral properties are found with a survey of orbits about a black hole taken to be rotating at 80% of the maximal spin. The orbital eccentricity is varied from 0.1 to 0.9. Inclination ranges from 20 deg. to 160 deg. and comes to within 20 deg. of polar. Semilatus rectum is varied from 1.2 to 3 times the value at the innermost stable circular orbits. The following general spectral properties are found: (i) 99% of the radiated power is typically carried by a few hundred modes, and at most by about a thousand modes, (ii) the dominant frequencies can be grouped into a small number of families defined by fixing two of the three integer frequency multipliers, and (iii) the specifics of these trends can be qualitatively inferred from the geometry of the orbit under consideration. Detections using triperiodic analytic templates modeled on these general properties would constitute a verification of radiation from an adiabatic sequence of black hole orbits and would recover the evolution of the fundamental orbital frequencies. In an analogy with ordinary spectroscopy, this would compare to observing the Bohr model's atomic hydrogen spectrum without being able to rule out alternative atomic theories or nuclei. The suitability of such a detection technique is demonstrated using snapshots computed at 12-hour intervals throughout the last three years before merger of a kludged inspiral. The system chosen is typical of those thought to occur in galactic nuclei and to be observable with space-based gravitational wave detectors like LISA. Because of circularization, the number of excited modes decreases as the binary

  13. Comment to: "Particle-hole symmetry breaking in the pseudogap state of Bi2201"

    OpenAIRE

    Panas, Itai

    2010-01-01

    Shen et al. [1] recently reported on ARPES data from Pb-Bi2201 revealing both particle-hole symmetry breaking and pronounced spectral broadening, which they interpret to be indicative of spatial symmetry breaking without long-range order at the opening of the pseudogap. Here is demonstrated how their results could be interpreted to reflect static and dynamic inhomogeneous crystal fields causing inter-band transfer of holes upon cooling below T*. Possible relevance to formation of charge carri...

  14. FIRST LONG-TERM OPTICAL SPECTRAL MONITORING OF A BINARY BLACK HOLE CANDIDATE E1821+643. I. VARIABILITY OF SPECTRAL LINES AND CONTINUUM

    International Nuclear Information System (INIS)

    Shapovalova, A. I.; Burenkov, A. N.; Zhdanova, V. E.; Popović, L. Č.; Chavushyan, V. H.; Valdés, J. R.; Patiño-Álvarez, V.; León-Tavares, J.; Torrealba, J.; Ilić, D.; Kovačević, A.; Kollatschny, W.

    2016-01-01

    We report the results of the first long-term (1990–2014) optical spectrophotometric monitoring of a binary black hole candidate QSO E1821+643, a low-redshift, high-luminosity, radio-quiet quasar. In the monitored period, the continua and Hγ fluxes changed about two times, while the Hβ flux changed about 1.4 times. We found periodical variations in the photometric flux with periods of 1200, 1850, and 4000 days, and 4500-day periodicity in the spectroscopic variations. However, the periodicity of 4000–4500 days covers only one cycle of variation and should be confirmed with a longer monitoring campaign. There is an indication of the period around 1300 days in the spectroscopic light curves, buts with small significance level, while the 1850-day period could not be clearly identified in the spectroscopic light curves. The line profiles have not significantly changed, showing an important red asymmetry and broad line peak redshifted around +1000 km s −1 . However, Hβ shows a broader mean profile and has a larger time lag (τ ∼ 120 days) than Hγ (τ ∼ 60 days). We estimate that the mass of the black hole is ∼2.6 × 10 9 M ⊙ . The obtained results are discussed in the frame of the binary black hole hypothesis. To explain the periodicity in the flux variability and high redshift of the broad lines, we discuss a scenario where dense, gas-rich, cloudy-like structures are orbiting around a recoiling black hole

  15. Making of a burn unit: SOA burn center

    Directory of Open Access Journals (Sweden)

    Jayant Kumar Dash

    2016-01-01

    Full Text Available Each year in India, burn injuries account for more than 6 million hospital emergency department visits; of which many require hospitalization and are referred to specialized burn centers. There are few burn surgeons and very few burn centers in India. In our state, Odisha, there are only two burn centers to cater to more than 5000 burn victims per year. This article is an attempt to share the knowledge that I acquired while setting up a new burn unit in a private medical college of Odisha.

  16. Development of spectral history methods for pin-by-pin core analysis method using three-dimensional direct response matrix

    International Nuclear Information System (INIS)

    Mitsuyasu, T.; Ishii, K.; Hino, T.; Aoyama, M.

    2009-01-01

    Spectral history methods for pin-by-pin core analysis method using the three-dimensional direct response matrix have been developed. The direct response matrix is formalized by four sub-response matrices in order to respond to a core eigenvalue k and thus can be recomposed at each outer iteration in the core analysis. For core analysis, it is necessary to take into account the burn-up effect related to spectral history. One of the methods is to evaluate the nodal burn-up spectrum obtained using the out-going neutron current. The other is to correct the fuel rod neutron production rates obtained the pin-by-pin correction. These spectral history methods were tested in a heterogeneous system. The test results show that the neutron multiplication factor error can be reduced by half during burn-up, the nodal neutron production rates errors can be reduced by 30% or more. The root-mean-square differences between the relative fuel rod neutron production rate distributions can be reduced within 1.1% error. This means that these methods can accurately reflect the effects of intra- and inter-assembly heterogeneities during burn-up and can be used for core analysis. Core analysis with the DRM method was carried out for an ABWR quarter core and it was found that both thermal power and coolant-flow distributions were smoothly converged. (authors)

  17. Long-term Follow-up and Outcomes in Traumatic Macular Holes.

    Science.gov (United States)

    Miller, John B; Yonekawa, Yoshihiro; Eliott, Dean; Kim, Ivana K; Kim, Leo A; Loewenstein, John I; Sobrin, Lucia; Young, Lucy H; Mukai, Shizuo; Vavvas, Demetrios G

    2015-12-01

    To review presenting characteristics, clinical course, and long-term visual and anatomic outcomes of patients with traumatic macular holes at a tertiary referral center. Retrospective case series. Twenty-eight consecutive patients with traumatic macular holes at a single tertiary referral center were reviewed. In addition to visual acuities and treatments throughout the clinical course, specific dimensions of the macular hole, including diameters, height, configuration, shape, and the presence of a cuff of fluid, were examined using spectral-domain optical coherence tomography (OCT). Twenty-eight patients were identified with a mean initial visual acuity (VA) of logMAR 1.3 (20/400) and a mean follow-up of 2.2 years. Eleven holes (39.3%) closed spontaneously in median 5.7 weeks. Eleven underwent vitrectomy with a median time to intervention of 35.1 weeks. Median time to surgery for the 5 eyes with successful hole closure was 11.0 weeks vs 56.3 weeks for the 6 eyes that failed to close (P = .02). VA improved in closed holes (P holes that did not close (P = .22). There was no relation between initial OCT dimensions and final hole closure status, although there was a trend, which did not reach statistical significance, toward small dimensions for those that closed spontaneously. A fairly high spontaneous closure rate was observed, with a trend toward smaller OCT dimensions. We found no relationship between hole closure and the OCT characteristics of the hole. Surgical intervention was less successful at hole closure when elected after 3 months. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Hadronic spectral functions in nuclear matter

    International Nuclear Information System (INIS)

    Post, M.; Leupold, S.; Mosel, U.

    2004-01-01

    We study the in-medium properties of mesons (π,η,ρ) and baryon resonances in cold nuclear matter within a coupled-channel analysis. The meson self energies are generated by particle-hole excitations. Thus multi-peak spectra are obtained for the mesonic spectral functions. In turn this leads to medium-modifications of the baryon resonances. Special care is taken to respect the analyticity of the spectral functions and to take into account effects from short-range correlations both for positive and negative parity states. Our model produces sensible results for pion and Δ dynamics in nuclear matter. We find a strong interplay of the ρ meson and the D 13 (1520), which moves spectral strength of the ρ spectrum to smaller invariant masses and leads to a broadening of the baryon resonance. The optical potential for the η meson resulting from our model is rather attractive whereas the in-medium properties modifications of the S 11 (1535) are found to be quite small

  19. Electroacupuncture improves burn-induced impairment in gastric motility mediated via the vagal mechanism in rats.

    Science.gov (United States)

    Song, J; Yin, J; Sallam, H S; Bai, T; Chen, Y; Chen, J D Z

    2013-10-01

    Delayed gastric emptying (GE) is common in patients with severe burns. This study was designed to investigate effects and mechanisms of electroacupuncture (EA) on gastric motility in rats with burns. Male rats (intact and vagotomized) were implanted with gastric electrodes, chest and abdominal wall electrodes for investigating the effects of EA at ST-36 (stomach-36 or Zusanli) on GE, gastric slow waves, autonomic functions, and plasma interleukin 6 (IL-6) 6 and 24 h post severe burns. (i) Burn delayed GE (P Electroacupuncture improved GE 6 and 24 h post burn (P Electroacupuncture improved burn-induced gastric dysrhythmia. The percentage of normal slow waves was increased with EA 6 and 24 h post burn (P = 0.02). (iii) Electroacupuncture increased vagal activity assessed by the spectral analysis of heart rate variability (HRV). The high-frequency component reflecting vagal component was increased with EA 6 (P = 0.004) and 24 h post burn (P = 0.03, vs sham-EA). (iv) Electroacupuncture attenuated burn-induced increase in plasma IL-6 at both 6 (P = 0.03) and 24 h post burn (P = 0.003). Electroacupuncture at ST-36 improves gastric dysrhythmia and accelerates GE in rats with burns. The improvement seems to be mediated via the vagal pathway involving the inflammatory cytokine IL-6. © 2013 John Wiley & Sons Ltd.

  20. GRS 1758–258: RXTE Monitoring of a Rare Persistent Hard State Black Hole

    Directory of Open Access Journals (Sweden)

    M. Obst

    2011-01-01

    Full Text Available GRS 1758–258 is the least studied of the three persistent black hole X-ray binaries in our Galaxy. It is also one of only two known black hole candidates, including all black hole transients, which shows a decrease of its 3-10 keV flux when entering the thermally dominated soft state, rather than an increase.We present the spectral evolution of GRS 1758–258 from RXTE-PCA observations spanning a time of about 11 years from 1996 to 2007. During this time, seven dim soft states are detected. We also consider INTEGRAL monitoring observations of the source and compare the long-term behavior to that of the bright persistent black hole X-ray binary Cygnus X-1. We discuss the observed state transitions in the light of physical scenarios for black hole transitions.

  1. [Surgical treatment of burns : Special aspects of pediatric burns].

    Science.gov (United States)

    Bührer, G; Beier, J P; Horch, R E; Arkudas, A

    2017-05-01

    Treatment of pediatric burn patients is very important because of the sheer frequency of burn wounds and the possible long-term ramifications. Extensive burns need special care and are treated in specialized burn centers. The goal of this work is to present current standards in burn therapy and important innovations in the treatment of burns in children so that the common and small area burn wounds and scalds in pediatric patients in day-to-day dermatological practice can be adequately treated. Analysis of current literature, discussion of reviews, incorporation of current guidelines. Burns in pediatric patients are common. Improvement of survival can be achieved by treatment in burn centers. The assessment of burn depth and area is an important factor for proper treatment. We give an overview for outpatient treatment of partial thickness burns. New methods may result in better long-term outcome. Adequate treatment of burn injuries considering current literature and guidelines improves patient outcome. Rational implementation of new methods is recommended.

  2. Running-mass inflation model and primordial black holes

    International Nuclear Information System (INIS)

    Drees, Manuel; Erfani, Encieh

    2011-01-01

    We revisit the question whether the running-mass inflation model allows the formation of Primordial Black Holes (PBHs) that are sufficiently long-lived to serve as candidates for Dark Matter. We incorporate recent cosmological data, including the WMAP 7-year results. Moreover, we include ''the running of the running'' of the spectral index of the power spectrum, as well as the renormalization group ''running of the running'' of the inflaton mass term. Our analysis indicates that formation of sufficiently heavy, and hence long-lived, PBHs still remains possible in this scenario. As a by-product, we show that the additional term in the inflaton potential still does not allow significant negative running of the spectral index

  3. THE DISK-WIND-JET CONNECTION IN THE BLACK HOLE H 1743-322

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J. M.; King, A. L. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109-1042 (United States); Raymond, J. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Fabian, A. C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 OHA (United Kingdom); Reynolds, C. S. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Kallman, T. R. [Laboratory for High Energy Astrophysics, NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States); Cackett, E. M. [Department of Physics and Astronomy, Wayne State University, 666 West Hancock Street, Detroit, MI 48201 (United States); Van der Klis, M. [Astronomical Institute ' Anton Pannekoek' , University of Amsterdam, Science Park 904, 1098-XH, Amsterdam (Netherlands); Steeghs, D. T. H., E-mail: jonmm@umich.edu [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom)

    2012-11-01

    X-ray disk winds are detected in spectrally soft, disk-dominated phases of stellar-mass black hole outbursts. In contrast, compact, steady, relativistic jets are detected in spectrally hard states that are dominated by non-thermal X-ray emission. Although these distinctive outflows appear to be almost mutually exclusive, it is possible that a disk wind persists in hard states but cannot be detected via X-ray absorption lines owing to very high ionization. Here, we present an analysis of a deep, 60 ks Chandra/HETGS observation of the black hole candidate H 1743-322 in the low/hard state. The spectrum shows no evidence of a disk wind, with tight limits, and within the range of ionizing flux levels that were measured in prior Chandra observations wherein a wind was clearly detected. In H 1743-322, at least, disk winds are actually diminished in the low/hard state, and disk winds and jets are likely state dependent and anti-correlated. These results suggest that although the launching radii of winds and jets may differ by orders of magnitude, they may both be tied to a fundamental property of the inner accretion flow, such as the mass accretion rate and/or the magnetic field topology of the disk. We discuss these results in the context of disk winds and jets in other stellar-mass black holes, and possible launching mechanisms for black hole outflows.

  4. White holes and eternal black holes

    International Nuclear Information System (INIS)

    Hsu, Stephen D H

    2012-01-01

    We investigate isolated white holes surrounded by vacuum, which correspond to the time reversal of eternal black holes that do not evaporate. We show that isolated white holes produce quasi-thermal Hawking radiation. The time reversal of this radiation, incident on a black hole precursor, constitutes a special preparation that will cause the black hole to become eternal. (paper)

  5. Mapping burned areas using dense time-series of Landsat data

    Science.gov (United States)

    Hawbaker, Todd J.; Vanderhoof, Melanie; Beal, Yen-Ju G.; Takacs, Joshua; Schmidt, Gail L.; Falgout, Jeff T.; Williams, Brad; Brunner, Nicole M.; Caldwell, Megan K.; Picotte, Joshua J.; Howard, Stephen M.; Stitt, Susan; Dwyer, John L.

    2017-01-01

    Complete and accurate burned area data are needed to document patterns of fires, to quantify relationships between the patterns and drivers of fire occurrence, and to assess the impacts of fires on human and natural systems. Unfortunately, in many areas existing fire occurrence datasets are known to be incomplete. Consequently, the need to systematically collect burned area information has been recognized by the United Nations Framework Convention on Climate Change and the Intergovernmental Panel on Climate Change, which have both called for the production of essential climate variables (ECVs), including information about burned area. In this paper, we present an algorithm that identifies burned areas in dense time-series of Landsat data to produce the Landsat Burned Area Essential Climate Variable (BAECV) products. The algorithm uses gradient boosted regression models to generate burn probability surfaces using band values and spectral indices from individual Landsat scenes, lagged reference conditions, and change metrics between the scene and reference predictors. Burn classifications are generated from the burn probability surfaces using pixel-level thresholding in combination with a region growing process. The algorithm can be applied anywhere Landsat and training data are available. For this study, BAECV products were generated for the conterminous United States from 1984 through 2015. These products consist of pixel-level burn probabilities for each Landsat scene, in addition to, annual composites including: the maximum burn probability and a burn classification. We compared the BAECV burn classification products to the existing Global Fire Emissions Database (GFED; 1997–2015) and Monitoring Trends in Burn Severity (MTBS; 1984–2013) data. We found that the BAECV products mapped 36% more burned area than the GFED and 116% more burned area than MTBS. Differences between the BAECV products and the GFED were especially high in the West and East where the

  6. A study of angle dependent surface plasmon polaritons in nano-hole array structures

    Energy Technology Data Exchange (ETDEWEB)

    Balakrishnan, Shankar [Department of Physics and Astronomy, University of Western Ontario, London, Ontario N6A 3K7 (Canada); Lawson Health Research Institute, St. Joseph' s Health Care, London, Ontario N6A 4V2 (Canada); Najiminaini, Mohamadreza; Carson, Jeffrey J. L. [Lawson Health Research Institute, St. Joseph' s Health Care, London, Ontario N6A 4V2 (Canada); Department of Medical Biophysics, University of Western Ontario, London, Ontario N6A 3K7 (Canada); Singh, Mahi R. [Department of Physics and Astronomy, University of Western Ontario, London, Ontario N6A 3K7 (Canada)

    2016-07-21

    We report that the light-matter interaction in metallic nano-hole array structures possess a subwavelength hole radius and periodicity. The transmission coefficient for nano-hole array structures was measured for different angles of incidence of light. Each measured transmission spectrum had several peaks due to surface plasmon polaritons. A theory of the transmission coefficient was developed based on the quantum density matrix method. It was found that the location of the surface plasmon polariton and the heights of the spectral peaks were dependent on the angle of incidence of light. Good agreement was observed between the experimental and theoretical results. This property of these structures has opened up new possibilities for sensing applications.

  7. Photodissociation Spectroscopy of Cold Protonated Synephrine: Surprising Differences between IR-UV Hole-Burning and IR Photodissociation Spectroscopy of the O-H and N-H Modes.

    Science.gov (United States)

    Nieuwjaer, N; Desfrançois, C; Lecomte, F; Manil, B; Soorkia, S; Broquier, M; Grégoire, G

    2018-04-19

    We report the UV and IR photofragmentation spectroscopies of protonated synephrine in a cryogenically cooled Paul trap. Single (UV or IR) and double (UV-UV and IR-UV) resonance spectroscopies have been performed and compared to quantum chemistry calculations, allowing the assignment of the lowest-energy conformer with two rotamers depending on the orientation of the phenol hydroxyl (OH) group. The IR-UV hole burning spectrum exhibits the four expected vibrational modes in the 3 μm region, i.e., the phenol OH, C β -OH, and two NH 2 + stretches. The striking difference is that, among these modes, only the free phenol OH mode is active through IRPD. The protonated amino group acts as a proton donor in the internal hydrogen bond and displays large frequency shifts upon isomerization expected during the multiphoton absorption process, leading to the so-called IRMPD transparency. More interestingly, while the C β -OH is a proton acceptor group with moderate frequency shift for the different conformations, this mode is still inactive through IRPD.

  8. High-speed three-dimensional plasma temperature determination of axially symmetric free-burning arcs

    International Nuclear Information System (INIS)

    Bachmann, B; Ekkert, K; Bachmann, J-P; Marques, J-L; Schein, J; Kozakov, R; Gött, G; Schöpp, H; Uhrlandt, D

    2013-01-01

    In this paper we introduce an experimental technique that allows for high-speed, three-dimensional determination of electron density and temperature in axially symmetric free-burning arcs. Optical filters with narrow spectral bands of 487.5–488.5 nm and 689–699 nm are utilized to gain two-dimensional spectral information of a free-burning argon tungsten inert gas arc. A setup of mirrors allows one to image identical arc sections of the two spectral bands onto a single camera chip. Two-different Abel inversion algorithms have been developed to reconstruct the original radial distribution of emission coefficients detected with each spectral window and to confirm the results. With the assumption of local thermodynamic equilibrium we calculate emission coefficients as a function of temperature by application of the Saha equation, the ideal gas law, the quasineutral gas condition and the NIST compilation of spectral lines. Ratios of calculated emission coefficients are compared with measured ones yielding local plasma temperatures. In the case of axial symmetry the three-dimensional plasma temperature distributions have been determined at dc currents of 100, 125, 150 and 200 A yielding temperatures up to 20000 K in the hot cathode region. These measurements have been validated by four different techniques utilizing a high-resolution spectrometer at different positions in the plasma. Plasma temperatures show good agreement throughout the different methods. Additionally spatially resolved transient plasma temperatures have been measured of a dc pulsed process employing a high-speed frame rate of 33000 frames per second showing the modulation of the arc isothermals with time and providing information about the sensitivity of the experimental approach. (paper)

  9. The gravitational wave background from massive black hole binaries in Illustris: spectral features and time to detection with pulsar timing arrays

    Science.gov (United States)

    Kelley, Luke Zoltan; Blecha, Laura; Hernquist, Lars; Sesana, Alberto; Taylor, Stephen R.

    2017-11-01

    Pulsar timing arrays (PTAs) around the world are using the incredible consistency of millisecond pulsars to measure low-frequency gravitational waves from (super)massive black hole (MBH) binaries. We use comprehensive MBH merger models based on cosmological hydrodynamic simulations to predict the spectrum of the stochastic gravitational wave background (GWB). We use real time-of-arrival specifications from the European, NANOGrav, Parkes, and International PTA (IPTA) to calculate realistic times to detection of the GWB across a wide range of model parameters. In addition to exploring the parameter space of environmental hardening processes (in particular: stellar scattering efficiencies), we have expanded our models to include eccentric binary evolution which can have a strong effect on the GWB spectrum. Our models show that strong stellar scattering and high characteristic eccentricities enhance the GWB strain amplitude near the PTA-sensitive `sweet-spot' (near the frequency f = 1 yr-1), slightly improving detection prospects in these cases. While the GWB amplitude is degenerate between cosmological and environmental parameters, the location of a spectral turnover at low frequencies (f ≲ 0.1 yr-1) is strongly indicative of environmental coupling. At high frequencies (f ≳ 1 yr-1), the GWB spectral index can be used to infer the number density of sources and possibly their eccentricity distribution. Even with merger models that use pessimistic environmental and eccentricity parameters, if the current rate of PTA expansion continues, we find that the IPTA is highly likely to make a detection within about 10 yr.

  10. Activity of the supermassive black hole at the Galactic center

    International Nuclear Information System (INIS)

    Clavel, Maica

    2014-01-01

    Sagittarius A* is the supermassive black hole at the Galactic center. Due to its proximity, this specimen is an excellent laboratory to study the accretion processes occurring around black holes and to constrain the duty cycle of these objects. Sgr A* is currently extremely faint and despite the detection of daily flares, its luminosity remains at least eight orders of magnitude below its Eddington luminosity, making this specimen one of the least luminous known supermassive black holes. The radiative processes responsible for the daily variations of its luminosity have not been clearly identified yet. We present the results of a multi-wavelength campaign observing Sgr A* simultaneously in X-rays and in the near-infrared, using the XMM-Newton observatory and the VLT/NACO instrument. We studied the spectral variability of Sgr A* using the infrared data we obtained through a spectro-imaging technique. Uncertainties linked to the systematic errors are still large but the first tests applied seem to show that the spectral index of Sgr A* could depend on the black hole luminosity. On longer timescales, we demonstrate that Sgr A* experienced a higher level of activity in the recent past. Indeed, echoes of its past activity can be detected in the molecular material surrounding the black hole. They are traced by a strong signal in the iron fluorescence line at 6.4 keV. We achieved a complete and systematic study of this variable emission detected from the central molecular zone, using Chandra and XMM-Newton observatories. Our results confirm that Sgr A* experienced intense flares in the past few centuries, with a luminosity at least six orders of magnitude higher than its current one. In particular, we highlight for the first time the existence of two distinct transient events of relatively short duration, which are probably due to catastrophic events. These results are the first step needed to include Sgr A*'s activity into a broader understanding of the galactic nuclei

  11. Polycyclic aromatic hydrocarbons at selected burning grounds at Los Alamos National Laboratory

    International Nuclear Information System (INIS)

    Harris, B.W.; Minor, L.K.M.; Flucas, B.J.

    1998-02-01

    A commercial immunoassay field test (IFT) was used to rapidly assess the total concentrations of polycyclic aromatic hydrocarbons (PAHs) in the soil at selected burning grounds within the explosives corridor at Los Alamos National Laboratory (LANL). Results were compared with analyses obtained from LANL Analytical Laboratory and from a commercial laboratory. Both used the Environmental Protection Agency's (EPA's) Methods 8270 and 8310. EPA's Method 8270 employs gas chromatography and mass spectral analyses, whereas EPA's Method 8310 uses an ultraviolet detector in a high-performance liquid chromatography procedure. One crude oil sample and one diesel fuel sample, analyzed by EPA Method 8270, were included for references. On an average the IFT results were lower for standard samples and lower than the analytical laboratory results for the unknown samples. Sites were selected to determine whether the PAHs came from the material burned or the fuel used to ignite the burn, or whether they are produced by a high-temperature chemical reaction during the burn. Even though the crude oil and diesel fuel samples did contain measurable quantities of PAHs, there were no significant concentrations of PAHs detected in the ashes and soil at the burning grounds. Tests were made on fresh soil and ashes collected after a large burn and on aged soil and ashes known to have been at the site more than three years. Also analyzed were twelve-year-old samples from an inactive open burn cage

  12. THE DISK-WIND-JET CONNECTION IN THE BLACK HOLE H 1743–322

    International Nuclear Information System (INIS)

    Miller, J. M.; King, A. L.; Raymond, J.; Fabian, A. C.; Reynolds, C. S.; Kallman, T. R.; Cackett, E. M.; Van der Klis, M.; Steeghs, D. T. H.

    2012-01-01

    X-ray disk winds are detected in spectrally soft, disk-dominated phases of stellar-mass black hole outbursts. In contrast, compact, steady, relativistic jets are detected in spectrally hard states that are dominated by non-thermal X-ray emission. Although these distinctive outflows appear to be almost mutually exclusive, it is possible that a disk wind persists in hard states but cannot be detected via X-ray absorption lines owing to very high ionization. Here, we present an analysis of a deep, 60 ks Chandra/HETGS observation of the black hole candidate H 1743–322 in the low/hard state. The spectrum shows no evidence of a disk wind, with tight limits, and within the range of ionizing flux levels that were measured in prior Chandra observations wherein a wind was clearly detected. In H 1743–322, at least, disk winds are actually diminished in the low/hard state, and disk winds and jets are likely state dependent and anti-correlated. These results suggest that although the launching radii of winds and jets may differ by orders of magnitude, they may both be tied to a fundamental property of the inner accretion flow, such as the mass accretion rate and/or the magnetic field topology of the disk. We discuss these results in the context of disk winds and jets in other stellar-mass black holes, and possible launching mechanisms for black hole outflows.

  13. Burning Mouth Syndrome and "Burning Mouth Syndrome".

    Science.gov (United States)

    Rifkind, Jacob Bernard

    2016-03-01

    Burning mouth syndrome is distressing to both the patient and practitioner unable to determine the cause of the patient's symptoms. Burning mouth syndrome is a diagnosis of exclusion, which is used only after nutritional deficiencies, mucosal disease, fungal infections, hormonal disturbances and contact stomatitis have been ruled out. This article will explore the many causes and treatment of patients who present with a chief complaint of "my mouth burns," including symptomatic treatment for those with burning mouth syndrome.

  14. Spectral characteristics of aurorae connected with high-velocity flows of the solar wind from coronal holes

    International Nuclear Information System (INIS)

    Khviyuzova, T.A.; Leont'ev, S.V.

    1997-01-01

    Bright electron aurorae almost always followed by red lower edge occur when the Earth is being passed by high-velocity flows from coronal holes within the auroral range at the night meridian. In contrast to other types of the solar wind the high-velocity flows from coronal holes do not cause the occurrence of A type red polar aurorae, that is, the spectrum of electrons pouring into the Earth atmosphere in these cases is shifted towards higher energies

  15. X-ray time and spectral variability as probes of ultraluminous x-ray sources

    Science.gov (United States)

    Pasham, Dheeraj Ranga Reddy

    A long-standing debate in the field of ultraluminous X-ray sources (ULXs: luminosities > 3x1039 ergs s-1) is whether these objects are powered by stellar-mass black holes (mass range of 3-25 solar masses) undergoing hyper-accretion/emission or if they host the long-sought after class of intermediate-mass black holes (mass range of a few 100-1000 solar masses) accreting material at sub-Eddington rates. We present X-ray time and energy spectral variability studies of ULXs in order to understand their physical environments and accurately weigh their compact objects. A sample of ULXs exhibit quasi-periodic oscillations (QPOs) with centroid frequencies in the range of 10-200 mHz. The nature of the power density spectra (PDS) of these sources is qualitatively similar to stellar-mass black holes when they exhibit the so-called type-C low-frequency QPOs (frequency range of 0.2-15 Hz). However, the crucial difference is that the characteristic frequencies within the PDS of ULXs, viz., the break frequencies and the centroid frequencies of the QPOs, are scaled down by a factor of approximately 10-100 compared to stellar-mass black holes. It has thus been argued that the ULX mHz QPOs are the type-C low-frequency QPO analogs of stellar-mass black holes and that the observed difference in the frequencies (a fewx0.01 Hz compared with a few Hz) is due to the presence of intermediate-mass black holes ( MULX = (QPOstellar-mass black hole }/QPOULX)xM stellar-mass black hole, where M and QPO are the mass and the QPO frequency, respectively) within these ULXs. We analyzed all the archival XMM-Newton X-ray data of ULXs NGC 5408 X-1 and M82 X-1 in order to test the hypothesis that the ULX mHz QPOs are the type-C analogs by searching for a correlation between the mHz QPO frequency and the energy spectral power-law index as type-C QPOs show such a dependence. From our multi-epoch timing and spectral analysis of ULXs NGC 5408 X-1 and M82 X-1, we found that the mHz QPOs of these sources vary

  16. Measuring the Binary Black Hole Mass Spectrum with an Astrophysically Motivated Parameterization

    Science.gov (United States)

    Talbot, Colm; Thrane, Eric

    2018-04-01

    Gravitational-wave detections have revealed a previously unknown population of stellar mass black holes with masses above 20 M ⊙. These observations provide a new way to test models of stellar evolution for massive stars. By considering the astrophysical processes likely to determine the shape of the binary black hole mass spectrum, we construct a parameterized model to capture key spectral features that relate gravitational-wave data to theoretical stellar astrophysics. In particular, we model the signature of pulsational pair-instability supernovae, which are expected to cause all stars with initial mass 100 M ⊙ ≲ M ≲ 150 M ⊙ to form ∼40 M ⊙ black holes. This would cause a cutoff in the black hole mass spectrum along with an excess of black holes near 40 M ⊙. We carry out a simulated data study to illustrate some of the stellar physics that can be inferred using gravitational-wave measurements of binary black holes and demonstrate several such inferences that might be made in the near future. First, we measure the minimum and maximum stellar black hole mass. Second, we infer the presence of a peak due to pair-instability supernovae. Third, we measure the distribution of black hole mass ratios. Finally, we show how inadequate models of the black hole mass spectrum lead to biased estimates of the merger rate and the amplitude of the stochastic gravitational-wave background.

  17. Anatomical and Functional Results of Lamellar Macular Holes Surgery.

    Science.gov (United States)

    Papadopoulou, D; Donati, G; Mangioris, G; Pournaras, C J

    2016-04-01

    To determine the long-term surgical findings and outcomes after vitrectomy for symptomatic lamellar macular holes. We studied 28 patients with lamellar macular holes and central visual loss or distortion. All interventions were standard 25 G vitrectomy with membranectomy of the internal limiting membrane (ILM), peeling and gas tamponade with SF6 20 %. Operations were performed by a single experienced surgeon within the last 3 years. Best corrected visual acuity and optical coherence tomography appearance were determined preoperatively and postoperatively. Following the surgical procedure, all macular holes were closed; however, in 3 eyes, significant foveal thinning was associated with changes in the retinal pigment epithelium changes. The mean best-corrected visual acuity improved postoperatively in the majority of the patients (n: 21, mean 0.3 logMAR), stabilised in 4 patients and decreased in 3 patients (mean 0.4 logMAR). Spectral Domain-Optical coherence tomography (SD-OCT) showed resolution of the lamellar lesion and improved macular contour in all cases. We demonstrated improvement in postoperative vision and the anatomical reconstruction of the anatomical contour of the fovea in most eyes with symptomatic lamellar holes. These findings indicate that vitrectomy, membranectomy and ILM peeling with gas tamponade is a beneficial treatment of symptomatic lamellar macular holes. Georg Thieme Verlag KG Stuttgart · New York.

  18. The source of multi spectral energy of solar energetic electron

    Energy Technology Data Exchange (ETDEWEB)

    Herdiwijaya, Dhani [Astronomy Division and Bosscha Observatory, Faculty Mathematics and Natural Sciences, Intitute Technology of Bandung, Ganesha 10, Bandung, Indonesia 40132 dhani@as.itb.ac.id (Indonesia)

    2015-04-16

    We study the solar energetic electron distribution obtained from ACE and GOES satellites which have different altitudes and electron spectral energy during the year 1997 to 2011. The electron spectral energies were 0.038–0.315 MeV from EPAM instrument onboard ACE satellite and >2 MeV from GOES satellite. We found that the low electron energy has no correlation with high energy. In spite of we have corrected to the altitude differences. It implied that they originated from time dependent events with different sources and physical processes at the solar atmosphere. The sources of multi spectral energetic electron were related to flare and CME phenomena. However, we also found that high energetic electron comes from coronal hole.

  19. Burned area detection based on Landsat time series in savannas of southern Burkina Faso

    Science.gov (United States)

    Liu, Jinxiu; Heiskanen, Janne; Maeda, Eduardo Eiji; Pellikka, Petri K. E.

    2018-02-01

    West African savannas are subject to regular fires, which have impacts on vegetation structure, biodiversity and carbon balance. An efficient and accurate mapping of burned area associated with seasonal fires can greatly benefit decision making in land management. Since coarse resolution burned area products cannot meet the accuracy needed for fire management and climate modelling at local scales, the medium resolution Landsat data is a promising alternative for local scale studies. In this study, we developed an algorithm for continuous monitoring of annual burned areas using Landsat time series. The algorithm is based on burned pixel detection using harmonic model fitting with Landsat time series and breakpoint identification in the time series data. This approach was tested in a savanna area in southern Burkina Faso using 281 images acquired between October 2000 and April 2016. An overall accuracy of 79.2% was obtained with balanced omission and commission errors. This represents a significant improvement in comparison with MODIS burned area product (67.6%), which had more omission errors than commission errors, indicating underestimation of the total burned area. By observing the spatial distribution of burned areas, we found that the Landsat based method misclassified cropland and cloud shadows as burned areas due to the similar spectral response, and MODIS burned area product omitted small and fragmented burned areas. The proposed algorithm is flexible and robust against decreased data availability caused by clouds and Landsat 7 missing lines, therefore having a high potential for being applied in other landscapes in future studies.

  20. To burn or not to burn

    International Nuclear Information System (INIS)

    Busch, L.

    1993-01-01

    While taking a match to an oil slick may sound like the making of a chaotic inferno, emergency response specialists say burning may be the most efficient way to remove large oil spills from the ocean's surface. But tests of this technique are being resisted by environmentalists as well as the Environmental Protection Agency (EPA), which has final authority over the matter. The debate over test burning arose most recently in Alaska when a proposal to spill and then ignite 1,000 barrels of crude on the Arctic Ocean this past summer was rejected by the EPA. The EPA didn't object to the technique or to the notion of burning spilled oil. However, it contends that it's not necessary to spill thousands of gallons of oil to conduct tests, and unnecessarily pollute the environment, when plenty of oil is already available from accidental spills. Researchers disagree, claiming they won't be able to use the burning technique on an actual spill until it has been tested in a controlled experiment. Despite such concerns, the Canadian government is going ahead with a test burn off the coast of Newfoundland next year. Faced with a choice of test burning or the kind of shoreline contamination left in the wake of the Exxon Valdez disaster, Environment Canada opts for testing. Learning valuable lessons about rapid oil-spill cleanup is worth the relatively minor risks to the environment that test burning would pose

  1. Satellite-based evidence of wavelength-dependent aerosol absorption in biomass burning smoke inferred from Ozone Monitoring Instrument

    Directory of Open Access Journals (Sweden)

    H. Jethva

    2011-10-01

    Full Text Available We provide satellite-based evidence of the spectral dependence of absorption in biomass burning aerosols over South America using near-UV measurements made by the Ozone Monitoring Instrument (OMI during 2005–2007. In the current near-UV OMI aerosol algorithm (OMAERUV, it is implicitly assumed that the only absorbing component in carbonaceous aerosols is black carbon whose imaginary component of the refractive index is wavelength independent. With this assumption, OMI-derived aerosol optical depth (AOD is found to be significantly over-estimated compared to that of AERONET at several sites during intense biomass burning events (August-September. Other well-known sources of error affecting the near-UV method of aerosol retrieval do not explain the large observed AOD discrepancies between the satellite and the ground-based observations. A number of studies have revealed strong spectral dependence in carbonaceous aerosol absorption in the near-UV region suggesting the presence of organic carbon in biomass burning generated aerosols. A sensitivity analysis examining the importance of accounting for the presence of wavelength-dependent aerosol absorption in carbonaceous particles in satellite-based remote sensing was carried out in this work. The results convincingly show that the inclusion of spectrally-dependent aerosol absorption in the radiative transfer calculations leads to a more accurate characterization of the atmospheric load of carbonaceous aerosols. The use of a new set of aerosol models assuming wavelength-dependent aerosol absorption in the near-UV region (Absorption Angstrom Exponent λ−2.5 to −3.0 improved the OMAERUV retrieval results by significantly reducing the AOD bias observed when gray aerosols were assumed. In addition, the new retrieval of single-scattering albedo is in better agreement with those of AERONET within the uncertainties (ΔSSA = ±0.03. The new colored carbonaceous aerosol model was also found to

  2. Inflation and dark matter primordial black holes

    International Nuclear Information System (INIS)

    Erfani, Encieh

    2012-09-01

    In this thesis a broad range of single field models of inflation are analyzed in light of all relevant recent cosmological data, checking whether they can lead to the formation of long-lived Primordial Black Holes (PBHs) to serve as candidates for Dark Matter. To that end we calculate the spectral index of the power spectrum of primordial perturbations as well as its first and second derivatives. PBH formation is possible only if the spectral index increases significantly at small scales, i.e. large wave number k. Since current data indicate that the first derivative α S of the spectral index n S (k pivot ) is negative at the pivot scale k pivot , PBH formation is only possible in the presence of a sizable and positive second derivative (''running of the running'') β S . Among the three small-field and five large-field inflation models we analyze, only one small-field model, the ''running-mass'' model, allows PBH formation, for a narrow range of parameters. We also note that none of the models we analyze can accord for a large and negative value of α S , which is weakly preferred by current data. Similarly, proving conclusively that the second derivative of the spectral index is positive would exclude all the large-field models we investigated.

  3. Novel burn device for rapid, reproducible burn wound generation.

    Science.gov (United States)

    Kim, J Y; Dunham, D M; Supp, D M; Sen, C K; Powell, H M

    2016-03-01

    Scarring following full thickness burns leads to significant reductions in range of motion and quality of life for burn patients. To effectively study scar development and the efficacy of anti-scarring treatments in a large animal model (female red Duroc pigs), reproducible, uniform, full-thickness, burn wounds are needed to reduce variability in observed results that occur with burn depth. Prior studies have proposed that initial temperature of the burner, contact time with skin, thermal capacity of burner material, and the amount of pressure applied to the skin need to be strictly controlled to ensure reproducibility. The purpose of this study was to develop a new burner that enables temperature and pressure to be digitally controlled and monitored in real-time throughout burn wound creation and compare it to a standard burn device. A custom burn device was manufactured with an electrically heated burn stylus and a temperature control feedback loop via an electronic microstat. Pressure monitoring was controlled by incorporation of a digital scale into the device, which measured downward force. The standard device was comprised of a heat resistant handle with a long rod connected to the burn stylus, which was heated using a hot plate. To quantify skin surface temperature and internal stylus temperature as a function of contact time, the burners were heated to the target temperature (200±5°C) and pressed into the skin for 40s to create the thermal injuries. Time to reach target temperature and elapsed time between burns were recorded. In addition, each unit was evaluated for reproducibility within and across three independent users by generating burn wounds at contact times spanning from 5 to 40s at a constant pressure and at pressures of 1 or 3lbs with a constant contact time of 40s. Biopsies were collected for histological analysis and burn depth quantification using digital image analysis (ImageJ). The custom burn device maintained both its internal

  4. The Case Mix of Patients Presenting with Full-Thickness Macular Holes and Progression before Surgery: Implications for Optimum Management.

    Science.gov (United States)

    Madi, Haifa A; Dinah, Christiana; Rees, Jon; Steel, David H W

    2015-01-01

    Analysis of pre-operative spectral domain optical coherence tomography (SD-OCT) characteristics of full-thickness macular holes (FTMH) and effect on optimum management. We retrospectively reviewed SD-OCT characteristics of a consecutive cohort of patients waitlisted for FTMH surgery and categorized them by current evidence-based treatments. Out of the 106 holes analysed, 36 were small, 40 medium and 30 large. Initially, 33 holes had vitreomacular adhesion (VMA). 41 holes were analysed for change in characteristics with a median duration of 8 weeks between the scans. The number of small or medium holes decreased from 20 to 6 and that of large holes doubled. The number of holes with VMA halved. Smaller hole size (p = 0.014) and being phakic (p = 0.048) were associated with a larger increase in size. The strongest predictor of hole progression into a different surgical management category was the presence of VMA. FTMH characteristics can change significantly pre-operatively and affect optimal treatment choice.

  5. On the Calculation of the Fe K-alpha Line Emissivity of Black Hole Accretion Disks

    Energy Technology Data Exchange (ETDEWEB)

    Krawczynski, H.; Beheshtipour, B., E-mail: krawcz@wustl.edu [Physics Department and McDonnell Center for the Space Sciences, Washington University in St. Louis, 1 Brookings Drive, CB 1105, St. Louis, MO 63130 (United States)

    2017-11-01

    Observations of the fluorescent Fe K α emission line from the inner accretion flows of stellar mass black holes in X-ray binaries and supermassive black holes in active galactic nuclei have become an important tool to study the magnitude and inclination of the black hole spin, and the structure of the accretion flow close to the event horizon of the black hole. Modeling spectral, timing, and soon also X-ray polarimetric observations of the Fe K α emission requires the calculation of the specific intensity in the rest frame of the emitting plasma. We revisit the derivation of the equation used for calculating the illumination of the accretion disk by the corona. We present an alternative derivation leading to a simpler equation, and discuss the relation to previously published results.

  6. Spectral flow, and the spectrum of multicenter solutions

    International Nuclear Information System (INIS)

    Bena, Iosif; Bobev, Nikolay; Warner, Nicholas P.

    2008-01-01

    We discuss 'spectral-flow' coordinate transformations that take asymptotically four-dimensional solutions into other asymptotically four-dimensional solutions. We find that spectral flow can relate smooth three-charge solutions with a multicenter Taub-NUT base to solutions where one or several Taub-NUT centers are replaced by two-charge supertubes, and vice versa. We further show that multiparameter spectral flows can map such Taub-NUT centers to more singular centers that are either D2-D0 or pure D0-brane sources. Since supertubes can depend on arbitrary functions, we establish that the moduli space of smooth horizonless black-hole microstate solutions is classically of infinite dimension. We also use the physics of supertubes to argue that some multicenter solutions that appear to be bound states from a four-dimensional perspective are in fact not bound states when considered from a five- or six-dimensional perspective

  7. NuSTARand Swift observations of the very high state in GX 339-4: Weighing the black hole with X-rays

    DEFF Research Database (Denmark)

    Parker, M. L.; Tomsick, J. A.; Kennea, J. A.

    2016-01-01

    We present results from spectral fitting of the very high state of GX 339-4 with Nuclear Spectroscopic Telescope Array (NuSTAR) and Swift. We use relativistic reflection modeling to measure the spin of the black hole and inclination of the inner disk and find a spin of a = 0.95(-0.08)(+0.02) and ......We present results from spectral fitting of the very high state of GX 339-4 with Nuclear Spectroscopic Telescope Array (NuSTAR) and Swift. We use relativistic reflection modeling to measure the spin of the black hole and inclination of the inner disk and find a spin of a = 0...

  8. Primordial black holes from passive density fluctuations

    OpenAIRE

    Lin, Chia-Min; Ng, Kin-Wang

    2013-01-01

    In this paper, we show that if passive fluctuations are considered, primordial black holes (PBHs) can be easily produced in the framework of single-field, slow-roll inflation models. The formation of PBHs is due to the blue spectrum of passive fluctuations and an enhancement of the spectral range which exits horizon near the end of inflation. Therefore the PBHs are light with masses $\\lesssim 10^{15}g$ depending on the number of e-folds when the scale of our observable universe leaves horizon...

  9. Burns education for non-burn specialist clinicians in Western Australia.

    Science.gov (United States)

    McWilliams, Tania; Hendricks, Joyce; Twigg, Di; Wood, Fiona

    2015-03-01

    Burn patients often receive their initial care by non-burn specialist clinicians, with increasingly collaborative burn models of care. The provision of relevant and accessible education for these clinicians is therefore vital for optimal patient care. A two phase design was used. A state-wide survey of multidisciplinary non-burn specialist clinicians throughout Western Australia identified learning needs related to paediatric burn care. A targeted education programme was developed and delivered live via videoconference. Pre-post-test analysis evaluated changes in knowledge as a result of attendance at each education session. Non-burn specialist clinicians identified numerous areas of burn care relevant to their practice. Statistically significant differences between perceived relevance of care and confidence in care provision were reported for aspects of acute burn care. Following attendance at the education sessions, statistically significant increases in knowledge were noted for most areas of acute burn care. Identification of learning needs facilitated the development of a targeted education programme for non-burn specialist clinicians. Increased non-burn specialist clinician knowledge following attendance at most education sessions supports the use of videoconferencing as an acceptable and effective method of delivering burns education in Western Australia. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

  10. Is proportion burned severely related to daily area burned?

    International Nuclear Information System (INIS)

    Birch, Donovan S; Morgan, Penelope; Smith, Alistair M S; Kolden, Crystal A; Hudak, Andrew T

    2014-01-01

    The ecological effects of forest fires burning with high severity are long-lived and have the greatest impact on vegetation successional trajectories, as compared to low-to-moderate severity fires. The primary drivers of high severity fire are unclear, but it has been hypothesized that wind-driven, large fire-growth days play a significant role, particularly on large fires in forested ecosystems. Here, we examined the relative proportion of classified burn severity for individual daily areas burned that occurred during 42 large forest fires in central Idaho and western Montana from 2005 to 2007 and 2011. Using infrared perimeter data for wildfires with five or more consecutive days of mapped perimeters, we delineated 2697 individual daily areas burned from which we calculated the proportions of each of three burn severity classes (high, moderate, and low) using the differenced normalized burn ratio as mapped for large fires by the Monitoring Trends in Burn Severity project. We found that the proportion of high burn severity was weakly correlated (Kendall τ = 0.299) with size of daily area burned (DAB). Burn severity was highly variable, even for the largest (95th percentile) in DAB, suggesting that other variables than fire extent influence the ecological effects of fires. We suggest that these results do not support the prioritization of large runs during fire rehabilitation efforts, since the underlying assumption in this prioritization is a positive relationship between severity and area burned in a day. (letters)

  11. GOME-2A retrievals of tropospheric NO2 in different spectral ranges – influence of penetration depth

    Directory of Open Access Journals (Sweden)

    L. K. Behrens

    2018-05-01

    Full Text Available In this study, we present a novel nitrogen dioxide (NO2 differential optical absorption spectroscopy (DOAS retrieval in the ultraviolet (UV spectral range for observations from the Global Ozone Monitoring Instrument 2 on board EUMETSAT's MetOp-A (GOME-2A satellite. We compare the results to those from an established NO2 retrieval in the visible (vis spectral range from the same instrument and investigate how differences between the two are linked to the NO2 vertical profile shape in the troposphere.As expected, radiative transfer calculations for satellite geometries show that the sensitivity close to the ground is higher in the vis than in the UV spectral range. Consequently, NO2 slant column densities (SCDs in the vis are usually higher than in the UV if the NO2 is close to the surface. Therefore, these differences in NO2 SCDs between the two spectral ranges contain information on the vertical distribution of NO2 in the troposphere. We combine these results with radiative transfer calculations and simulated NO2 fields from the TM5-MP chemistry transport model to evaluate the simulated NO2 vertical distribution.We investigate regions representative of both anthropogenic and biomass burning NO2 pollution. Anthropogenic air pollution is mostly located in the boundary layer close to the surface, which is reflected by large differences between UV and vis SCDs of  ∼  60 %. Biomass burning NO2 in contrast is often uplifted into elevated layers above the boundary layer. This is best seen in tropical Africa south of the Equator, where the biomass burning NO2 is well observed in the UV, and the SCD difference between the two spectral ranges is only  ∼  36 %. In tropical Africa north of the Equator, however, the biomass burning NO2 is located closer to the ground, reducing its visibility in the UV.While not enabling a full retrieval of the vertical NO2 profile shape in the troposphere, our results can help to constrain the vertical

  12. AS ABOVE, SO BELOW: EXPLOITING MASS SCALING IN BLACK HOLE ACCRETION TO BREAK DEGENERACIES IN SPECTRAL INTERPRETATION

    International Nuclear Information System (INIS)

    Markoff, Sera; Silva, Catia V.; Nowak, Michael A.; Gallo, Elena; Plotkin, Richard M.; Hynes, Robert; Wilms, Jörn; Maitra, Dipankar; Drappeau, Samia

    2015-01-01

    Over the past decade, evidence has mounted that several aspects of black hole (BH) accretion physics proceed in a mass-invariant way. One of the best examples of this scaling is the empirical “fundamental plane of BH accretion” relation linking mass, radio, and X-ray luminosity over eight orders of magnitude in BH mass. The currently favored theoretical interpretation of this relation is that the physics governing power output in weakly accreting BHs depends more on relative accretion rate than on mass. In order to test this theory, we explore whether a mass-invariant approach can simultaneously explain the broadband spectral energy distributions from two BHs at opposite ends of the mass scale but that are at similar Eddington accretion fractions. We find that the same model, with the same value of several fitted physical parameters expressed in mass-scaling units to enforce self-similarity, can provide a good description of two data sets from V404 Cyg and M81*, a stellar and supermassive BH, respectively. Furthermore, only one of several potential emission scenarios for the X-ray band is successful, suggesting it is the dominant process driving the fundamental plane relation at this accretion rate. This approach thus holds promise for breaking current degeneracies in the interpretation of BH high-energy spectra and for constructing better prescriptions of BH accretion for use in various local and cosmological feedback applications

  13. An assessment of burn care professionals' attitudes to major burn.

    LENUS (Irish Health Repository)

    Murphy, A D

    2008-06-01

    The resuscitation of severe burn remains a controversial area within the burn care profession. There is ongoing debate as to what percentage burn is associated with a sufficient quality of life to support initial resuscitation efforts. We conducted a survey of delegates at the 39th Annual Meeting of the British Burns Association (2005), regarding attitudes towards resuscitation following major burns. Respondents were asked the maximum percentage total body surface area (TBSA) burn beyond which they would not wish to be resuscitated. They were also asked what maximum TBSA they perceived to be commensurate with an acceptable quality of life (QOL). One hundred and forty three of 300 delegates responded to the questionnaire. Thirty three percent of respondents would not wish to be resuscitated with 50-75% TBSA burns or greater. A further 35% would not wish to have life-sustaining intervention with 75-95% TBSA burns or greater. The remaining 32% indicated that they would not want resuscitation with TBSA burns>95%. Regardless of TBSA affected, 16% would not wish resuscitation if they had full thickness facial burns, a further 10% did not want resuscitation if both their hands and faces were affected. Our survey demonstrates the diversity of personal preference amongst burn care professionals. This would suggest that a unifying philosophy regarding the resuscitation of extensive burns will remain elusive.

  14. Air-Freshener Burns: A New Paradigm in Burns Etiology?

    OpenAIRE

    Sarwar, Umran; Nicolaou, M.; Khan, M. S.; Tiernan, E.

    2011-01-01

    Objectives: We report a rare case of burns following the use of automated air-fresheners. Methods: We present a case report with a brief overview of the literature relating to burns associated with air-fresheners. The mechanism and treatment of these types of injuries are also described. Results: A 44 year-old female was admitted under the care of the burns team following burns secondary to an exploding air-freshener canister. The patient sustained burns to the face, thorax and arms re...

  15. Air-freshener burns: a new paradigm in burns etiology?

    Science.gov (United States)

    Sarwar, Umran; Nicolaou, M; Khan, M S; Tiernan, E

    2011-10-01

    We report a rare case of burns following the use of automated air-fresheners. We present a case report with a brief overview of the literature relating to burns associated with air-fresheners. The mechanism and treatment of these types of injuries are also described. A 44 year-old female was admitted under the care of the burns team following burns secondary to an exploding air-freshener canister. The patient sustained burns to the face, thorax and arms resulting in a seven-day hospital admission. The burns were treated conservatively. To our knowledge this is one of the few documented cases of burns as a result of air-fresheners. As they become more ubiquitous, we anticipate the incidence of such cases to increase. As such, they pose a potential public health concern on a massive scale.

  16. Spectral State Evolution of 4U 1820-30: the Stability of the Spectral Index of Comptonization Tail

    Science.gov (United States)

    Titarchuk, Lev G.; Seifina, Elena; Frontera, Filippo

    2013-01-01

    We analyze the X-ray spectra and their timing properties of the compact Xray binary 4U 1820-30. We establish spectral transitions in this source seen with BeppoSAX and the Rossi X-ray Timing Explorer (RXTE). During the RXTE observations (1996 - 2009), the source were approximately approximately 75% of its time in the soft state making the lower banana and upper banana transitions combined with long-term low-high state transitions. We reveal that all of the X-ray spectra of 4U 1820-30 are fit by a composition of a thermal (blackbody) component, a Comptonization component (COMPTB) and a Gaussian-line component. Thus using this spectral analysis we find that the photon power-law index Gamma of the Comptonization component is almost unchangeable (Gamma approximately 2) while the electron temperature kTe changes from 2.9 to 21 keV during these spectral events. We also establish that for these spectral events the normalization of COMPTB component (which is proportional to mass accretion rate ?M) increases by factor 8 when kTe decreases from 21 keV to 2.9 keV. Before this index stability effect was also found analyzing X-ray data for Z-source GX 340+0 and for atolls, 4U 1728-34, GX 3+1. Thus, we can suggest that this spectral stability property is a spectral signature of an accreting neutron star source. On the other hand in a black hole binary G monotonically increases with ?Mand ultimately its value saturates at large ?M.

  17. Neutron Stars and Black Holes New clues from Chandra and XMM-Newton

    CERN Multimedia

    CERN. Geneva. Audiovisual Unit

    2002-01-01

    Neutron stars and black holes, the most compact astrophysical objects, have become observable in many different ways during the last few decades. We will first review the phenomenology and properties of neutron stars and black holes (stellar and supermassive) as derived from multiwavelength observatories. Recently much progress has been made by means of the new powerful X-ray observatories Chandra and XMM-Newton which provide a substantial increase in sensitivity as well as spectral and angular resolution compared with previous satellites like ROSAT and ASCA. We shall discuss in more detail two recent topics: (1) The attempts to use X-ray spectroscopy for measuring the radii of neutron stars which depend on the equation of state at supranuclear densities. Have quark stars been detected? (2) The diagnostics of the strong gravity regions around supermassive black holes using X-ray spectroscopy.

  18. In-situ burning of Orimulsion : small scale burns

    International Nuclear Information System (INIS)

    Fingas, M.F.

    2002-01-01

    This study examined the feasibility of burning Orimulsion. In-situ burning has always been a viable method for cleaning oil spills on water because it can effectively reduce the amount of spilled oil and eliminate the need to collect, store, transport and dispose of recovered oil. Orimulsion, however, behaves very differently from conventional oil when it is spilled because of its composition of 70 per cent bitumen in 30 per cent water. In-situ burning of this surfactant-stablized oil-in-water emulsion has never been seriously considered because of the perception that Orimulsion could not be ignited, and if it could, ignition would not be sustained. In this study, burn tests were conducted on 3 scales in a Cleveland Open Cup apparatus of 5 cm, 10 cm and 50 cm diameters. Larger scale burns were conducted in specially built pans. All tests were conducted on salt water which caused the bitumen to separate from the water. The objective was to determine if sufficient vapours could be generated to ignite the Orimulsion. The study also measured if a sustained flame would result in successful combustion. Both objectives were successfully accomplished. Diesel fuel was used to ignite the Orimulsion in the specially designed pan for large scale combustion. Quantitative removal of Orimulsion was achieved in all cases, but in some burns it was necessary to re-ignite the Orimulsion. It was noted that when Orimulsion burns, some trapped water droplets in the bitumen explode with enough force to extinguish a small flame. This did not occur on large-scale burns. It was concluded that the potential for successful in-situ burning increases with size. It was determined that approximately 1 mm in thickness of diesel fuel is needed to ignite a burn. 5 refs., 3 tabs., 4 figs

  19. Gravitational wave production by Hawking radiation from rotating primordial black holes

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Ruifeng; Kinney, William H.; Stojkovic, Dejan, E-mail: ruifengd@buffalo.edu, E-mail: whkinney@buffalo.edu, E-mail: ds77@buffalo.edu [HEPCOS, Department of Physics, SUNY, University at Buffalo, Buffalo, NY 14260-1500 (United States)

    2016-10-01

    In this paper we analyze in detail a rarely discussed question of gravity wave production from evaporating primordial black holes. These black holes emit gravitons which are, at classical level, registered as gravity waves. We use the latest constraints on their abundance, and calculate the power emitted in gravitons at the time of their evaporation. We then solve the coupled system of equations that gives us the evolution of the frequency and amplitude of gravity waves during the expansion of the universe. The spectrum of gravitational waves that can be detected today depends on multiple factors: fraction of the total energy density which was occupied by primordial black holes, the epoch in which they were formed, and quantities like their mass and angular momentum. We conclude that very small primordial black holes which evaporate before the big-bang nucleosynthesis emit gravitons whose spectral energy fraction today can be as large as 10{sup −7.5}. On the other hand, those which are massive enough so that they still exist now can yield a signal as high as 10{sup −6.5}. However, typical frequencies of the gravity waves from primordial black holes are still too high to be observed with the current and near future gravity wave observations.

  20. EVIDENCE OF LIGHT-BENDING EFFECTS AND ITS IMPLICATION FOR SPECTRAL STATE TRANSITIONS

    International Nuclear Information System (INIS)

    Reis, R. C.; Miller, J. M.; Reynolds, M. T.; Fabian, A. C.; Walton, D. J.; Steiner, J. F.; Cackett, E.

    2013-01-01

    It has long been speculated that the nature of the hard X-ray corona may be an important second driver of black hole state transitions, in addition to the mass accretion rate through the disk. However, a clear physical picture of coronal changes has not yet emerged. We present results from a systematic analysis of Rossi X-Ray Timing Explorer observations of the stellar-mass black hole binary XTE J1650-500. All spectra with significant hard X-ray detections were fit using a self-consistent, relativistically blurred disk reflection model suited to high ionization regimes. Importantly, we find evidence that both the spectral and timing properties of black hole states may be partially driven by the height of the X-ray corona above the disk, and related changes in how gravitational light bending affects the corona-disk interaction. Specifically, the evolution of the power-law, thermal disk, and relativistically convolved reflection components in our spectral analysis indicates that: (1) the disk inner radius remains constant at r in =1.65 ± 0.08 GM/c 2 (consistent with values found for the ISCO of XTE J1650-500 in other works) throughout the transition from the brighter phases of the low-hard state to the intermediate states (both the hard-intermediate and soft-intermediate), through to the soft state and back; (2) the ratio between the observed reflected X-ray flux and power-law continuum (the 'reflection fraction', R) increases sharply at the transition between the hard-intermediate and soft-intermediate states ('ballistic' jets are sometimes launched at this transition); (3) both the frequency and coherence of the high-frequency quasi-periodic oscillations observed in XTE J1650-500 increase with R. We discuss our results in terms of black hole states and the nature of black hole accretion flows across the mass scale.

  1. Constructing binary black hole initial data with high mass ratios and spins

    Science.gov (United States)

    Ossokine, Serguei; Foucart, Francois; Pfeiffer, Harald; Szilagyi, Bela; Simulating Extreme Spacetimes Collaboration

    2015-04-01

    Binary black hole systems have now been successfully modelled in full numerical relativity by many groups. In order to explore high-mass-ratio (larger than 1:10), high-spin systems (above 0.9 of the maximal BH spin), we revisit the initial-data problem for binary black holes. The initial-data solver in the Spectral Einstein Code (SpEC) was not able to solve for such initial data reliably and robustly. I will present recent improvements to this solver, among them adaptive mesh refinement and control of motion of the center of mass of the binary, and will discuss the much larger region of parameter space this code can now address.

  2. The 2015 Indonesian biomass-burning season with extensive peat fires: Remote sensing measurements of biomass burning aerosol optical properties from AERONET and MODIS satellite data

    Science.gov (United States)

    Eck, T. F.; Holben, B. N.; Giles, D. M.; Smirnov, A.; Slutsker, I.; Sinyuk, A.; Schafer, J.; Sorokin, M. G.; Reid, J. S.; Sayer, A. M.; Hsu, N. Y. C.; Levy, R. C.; Lyapustin, A.; Wang, Y.; Rahman, M. A.; Liew, S. C.; Salinas Cortijo, S. V.; Li, T.; Kalbermatter, D.; Keong, K. L.; Elifant, M.; Aditya, F.; Mohamad, M.; Mahmud, M.; Chong, T. K.; Lim, H. S.; Choon, Y. E.; Deranadyan, G.; Kusumaningtyas, S. D. A.

    2016-12-01

    The strong El Nino event in 2015 resulted in below normal rainfall throughout Indonesia, which in turn allowed for exceptionally large numbers of biomass burning fires (including much peat burning) from Aug though Oct 2015. Over the island of Borneo, three AERONET sites measured monthly mean fine mode aerosol optical depth (AOD) at 500 nm from the spectral deconvolution algorithm in Sep and Oct ranging from 1.6 to 3.7, with daily average AOD as high as 6.1. In fact, the AOD was sometimes too high to obtain significant signal at mid-visible, therefore a newly developed algorithm in the AERONET Version 3 database was invoked to retain the measurements in as many of the longer wavelengths as possible. The AOD at longer wavelengths were then utilized to provide estimates of AOD at 550 nm with maximum values of 9 to 11. Additionally, satellite retrievals of AOD at 550 nm from MODIS data and the Dark Target, Deep Blue, and MAIAC algorithms were analyzed and compared to AERONET measured AOD. The AOD was sometimes too high for the satellite algorithms to make retrievals in the densest smoke regions. Since the AOD was often extremely high there was often insufficient AERONET direct sun signal at 440 nm for the larger solar zenith angles (> 50 degrees) required for almucantar retrievals. However, new hybrid sky radiance scans can attain sufficient scattering angle range even at small solar zenith angles when 440 nm direct beam irradiance can be accurately measured, thereby allowing for more retrievals and at higher AOD levels. The retrieved volume median radius of the fine mode increased from 0.18 to 0.25 micron as AOD increased from 1 to 3 (at 440 nm). These are very large size particles for biomass burning aerosol and are similar in size to smoke particles measured in Alaska during the very dry years of 2004 and 2005 (Eck et al. 2009) when peat soil burning also contributed to the fuel burned. The average single scattering albedo over the wavelength range of 440 to 1020 nm

  3. Inflation and dark matter primordial black holes

    Energy Technology Data Exchange (ETDEWEB)

    Erfani, Encieh

    2012-09-15

    In this thesis a broad range of single field models of inflation are analyzed in light of all relevant recent cosmological data, checking whether they can lead to the formation of long-lived Primordial Black Holes (PBHs) to serve as candidates for Dark Matter. To that end we calculate the spectral index of the power spectrum of primordial perturbations as well as its first and second derivatives. PBH formation is possible only if the spectral index increases significantly at small scales, i.e. large wave number k. Since current data indicate that the first derivative {alpha}{sub S} of the spectral index n{sub S}(k{sub pivot}) is negative at the pivot scale k{sub pivot}, PBH formation is only possible in the presence of a sizable and positive second derivative (''running of the running'') {beta}{sub S}. Among the three small-field and five large-field inflation models we analyze, only one small-field model, the ''running-mass'' model, allows PBH formation, for a narrow range of parameters. We also note that none of the models we analyze can accord for a large and negative value of {alpha}{sub S}, which is weakly preferred by current data. Similarly, proving conclusively that the second derivative of the spectral index is positive would exclude all the large-field models we investigated.

  4. Sectors of solutions in three-dimensional gravity and black holes

    International Nuclear Information System (INIS)

    Fjelstad, Jens; Hwang, Stephen

    2002-01-01

    We examine the connection between three-dimensional gravity with negative cosmological constant and two-dimensional CFT via the Chern-Simons formulation. A set of generalized spectral flow transformations are shown to yield new sectors of solutions. One implication is that the microscopic calculation of the entropy of the Banados-Teitelboim-Zanelli (BTZ) black hole is corrected by a multiplicative factor with the result that it saturates the Bekenstein-Hawking expression

  5. Sectors of solutions in three-dimensional gravity and black holes

    Energy Technology Data Exchange (ETDEWEB)

    Fjelstad, Jens E-mail: jens.fjelstad@kau.se; Hwang, Stephen E-mail: stephen.hwang@kau.se

    2002-04-29

    We examine the connection between three-dimensional gravity with negative cosmological constant and two-dimensional CFT via the Chern-Simons formulation. A set of generalized spectral flow transformations are shown to yield new sectors of solutions. One implication is that the microscopic calculation of the entropy of the Banados-Teitelboim-Zanelli (BTZ) black hole is corrected by a multiplicative factor with the result that it saturates the Bekenstein-Hawking expression.

  6. Biomass burning in Africa: As assessment of annually burned biomass

    International Nuclear Information System (INIS)

    Delmas, R.A.; Loudjani, P.; Podaire, A.; Menaut, J.C.

    1991-01-01

    It is now established that biomass burning is the dominant phenomenon that controls the atmospheric chemistry in the tropics. Africa is certainly the continent where biomass burning under various aspects and processes is the greatest. Three different types of burnings have to be considered-bush fires in savanna zones which mainly affect herbaceous flora, forest fires due to forestation for shifting agriculture or colonization of new lands, and the use of wood as fuel. The net release of carbon resulting from deforestation is assumed to be responsible for about 20% of the CO 2 increase in the atmosphere because the burning of forests corresponds to a destorage of carbon from the biospheric reservoir. The amount of reactive of greenhouse gases emitted by biomass burning is directly proportional, through individual emission factors, to the biomass actually burned. This chapter evaluates the biomass annually burned on the African continent as a result of the three main burning processes previously mentioned

  7. Black holes

    International Nuclear Information System (INIS)

    Feast, M.W.

    1981-01-01

    This article deals with two questions, namely whether it is possible for black holes to exist, and if the answer is yes, whether we have found any yet. In deciding whether black holes can exist or not the central role in the shaping of our universe played by the forse of gravity is discussed, and in deciding whether we are likely to find black holes in the universe the author looks at the way stars evolve, as well as white dwarfs and neutron stars. He also discusses the problem how to detect a black hole, possible black holes, a southern black hole, massive black holes, as well as why black holes are studied

  8. Impact of agriculture crop residue burning on atmospheric aerosol loading – a study over Punjab State, India

    Directory of Open Access Journals (Sweden)

    Darshan Singh

    2010-02-01

    Full Text Available The present study deals with the impact of agriculture crop residue burning on aerosol properties during October 2006 and 2007 over Punjab State, India using ground based measurements and multi-satellite data. Spectral aerosol optical depth (AOD and Ångström exponent (α values exhibited larger day to day variation during crop residue burning period. The monthly mean Ångström exponent "α" and turbidity parameter "β" values during October 2007 were 1.31±0.31 and 0.36±0.21, respectively. The higher values of "α" and "β" suggest turbid atmospheric conditions with increase in fine mode aerosols over the region during crop residue burning period. AURA-OMI derived Aerosol Index (AI and Nitrogen dioxide (NO2 showed higher values over the study region during October 2007 compared to October 2006 suggesting enhanced atmospheric pollution associated with agriculture crop residue burning.

  9. Effects of burn location and investigator on burn depth in a porcine model.

    Science.gov (United States)

    Singer, Adam J; Toussaint, Jimmy; Chung, Won Taek; Thode, Henry C; McClain, Steve; Raut, Vivek

    2016-02-01

    In order to be useful, animal models should be reproducible and consistent regardless of sampling bias, investigator creating burn, and burn location. We determined the variability in burn depth based on biopsy location, burn location and investigator in a porcine model of partial thickness burns. 24 partial thickness burns (2.5 cm by 2.5 cm each) were created on the backs of 2 anesthetized pigs by 2 investigators (one experienced, one inexperienced) using a previously validated model. In one of the pigs, the necrotic epidermis covering each burn was removed. Five full thickness 4mm punch biopsies were obtained 1h after injury from the four corners and center of the burns and stained with Hematoxylin and Eosin and Masson's trichrome for determination of burn depth by a board certified dermatopathologist blinded to burn location and investigator. Comparisons of burn depth by biopsy location, burn location and investigator were performed with t-tests and ANOVA as appropriate. The mean (SD) depth of injury to blood vessels (the main determinant of burn progression) in debrided and non-debrided pigs pooled together was 1.8 (0.3)mm, which included 75% of the dermal depth. Non-debrided burns were 0.24 mm deeper than debrided burns (Plocations, in debrided burns. Additionally, there were also no statistical differences in burn depths from midline to lateral in either of these burn types. Burn depth was similar for both investigators and among biopsy locations. Burn depth was greater for caudal locations in non-debrided burns and overall non-debrided burns were deeper than debrided burns. However, burn depth did not differ based on investigator, biopsy site, and medial-lateral location. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

  10. 30 CFR 816.87 - Coal mine waste: Burning and burned waste utilization.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Coal mine waste: Burning and burned waste...-SURFACE MINING ACTIVITIES § 816.87 Coal mine waste: Burning and burned waste utilization. (a) Coal mine... extinguishing operations. (b) No burning or burned coal mine waste shall be removed from a permitted disposal...

  11. A rapidly spinning supermassive black hole at the centre of NGC 1365

    DEFF Research Database (Denmark)

    Risaliti, G.; Harrison, F. A.; Madsen, K. K.

    2013-01-01

    and relativistic effects near the black hole, the line shape being sensitive to its spin. Alternative models in which the distortions result from absorption by intervening structures provide an equally good description of the data, and there has been no general agreement on which is correct. Recent claims...... that the black hole (2 × 10(6) solar masses) at the centre of the galaxy NGC 1365 is rotating at close to its maximum possible speed rest on the assumption of relativistic reflection. Here we report X-ray observations of NGC 1365 that reveal the relativistic disk features through broadened Fe-line emission...... and an associated Compton scattering excess of 10-30 kiloelectronvolts. Using temporal and spectral analyses, we disentangle continuum changes due to time-variable absorption from reflection, which we find arises from a region within 2.5 gravitational radii of the rapidly spinning black hole. Absorption...

  12. Broadband optical properties of biomass-burning aerosol and identification of brown carbon chromophores: OPTICAL AND CHEMICAL PROPERTIES OF BROWN CARBON AEROSOLS

    Energy Technology Data Exchange (ETDEWEB)

    Bluvshtein, Nir [Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot Israel; Lin, Peng [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland Washington USA; Flores, J. Michel [Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot Israel; Segev, Lior [Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot Israel; Mazar, Yinon [Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot Israel; Tas, Eran [The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot Israel; Snider, Graydon [Department of Physics and Atmospheric Science, Dalhousie University, Halifax Nova Scotia Canada; Weagle, Crystal [Department of Chemistry, Dalhousie University, Halifax Nova Scotia Canada; Brown, Steven S. [Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder Colorado USA; Chemical Sciences Division, Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder Colorado USA; Laskin, Alexander [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland Washington USA; Rudich, Yinon [Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot Israel

    2017-05-23

    The radiative effects of biomass burning aerosols on regional and global scale is substantial. Accurate modeling of the radiative effects of smoke aerosols require wavelength-dependent measurements and parameterizations of their optical properties in the UV and visible spectral ranges along with improved description of their chemical composition. To address this issue, we used a recently developed approach to retrieve the time- and spectral-dependent optical properties of ambient biomass burning aerosols between 300 and 650 nm wavelength during a regional bonfire festival in Israel. During the biomass burning event, the overall absorption at 400 nm increased by about two orders of magnitude, changing the size-weighted single scattering albedo from a background level of 0.95 to 0.7. Based on the new retrieval method, we provide parameterizations of the wavelength-dependent effective complex refractive index from 350 to 650 nm for freshly emitted and aged biomass burning aerosols. In addition, PM2.5 filter samples were collected for detailed off-line chemical analysis of the water soluble organics that contribute to light absorption. Nitrophenols were identified as the main organic species responsible for the increased absorption at 400-500 nm. These include species such as 4- nitrocatechol, 4-nitrophenol, nitro-syringol and nitro-guaiacol; oxidation-nitration products of methoxyphenols, known products of lignin pyrolysis. Our findings emphasize the importance of both primary and secondary organic aerosol from biomass burning in absorption of solar radiation and in effective radiative forcing.

  13. σ-holes and π-holes: Similarities and differences.

    Science.gov (United States)

    Politzer, Peter; Murray, Jane S

    2018-04-05

    σ-Holes and π-holes are regions of molecules with electronic densities lower than their surroundings. There are often positive electrostatic potentials associated with them. Through these potentials, the molecule can interact attractively with negative sites, such as lone pairs, π electrons, and anions. Such noncovalent interactions, "σ-hole bonding" and "π-hole bonding," are increasingly recognized as being important in a number of different areas. In this article, we discuss and compare the natures and characteristics of σ-holes and π-holes, and factors that influence the strengths and locations of the resulting electrostatic potentials. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  14. Impact of a Newly Implemented Burn Protocol on Surgically Managed Partial Thickness Burns at a Specialized Burns Center in Singapore.

    Science.gov (United States)

    Tay, Khwee-Soon Vincent; Chong, Si-Jack; Tan, Bien-Keem

    2016-03-01

    This study evaluated the impact of a newly implemented protocol for superficial to mid-dermal partial thickness burns which involves early surgery and rapid coverage with biosynthetic dressing in a specialized national burns center in Singapore. Consecutive patients with 5% or greater total body surface area (TBSA) superficial to mid-dermal partial thickness burns injury admitted to the Burns Centre at the Singapore General Hospital between August and December 2014 for surgery within 48 hours of injury were prospectively recruited into the study to form the protocol group. Comparable historical cases from the year 2013 retrieved from the burns center audit database were used to form the historical control group. Demographics (age, sex), type and depth of burns, %TBSA burnt, number of operative sessions, and length of stay were recorded for each patient of both cohorts. Thirty-nine burns patients managed under the new protocol were compared with historical control (n = 39) comparable in age and extensiveness of burns. A significantly shorter length of stay (P burns was observed in the new protocol group (0.74 day/%TBSA) versus historical control (1.55 day/%TBSA). Fewer operative sessions were needed under the new protocol for burns 10% or greater TBSA burns (P protocol for surgically managed burns patients which involves early surgery and appropriate use of biosynthetic dressing on superficial to mid-dermal partial thickness burns. Clinically, shorter lengths of stay, fewer operative sessions, and decreased need for skin grafting of burns patient were observed.

  15. Burns

    Science.gov (United States)

    A burn is damage to your body's tissues caused by heat, chemicals, electricity, sunlight, or radiation. Scalds from hot ... and gases are the most common causes of burns. Another kind is an inhalation injury, caused by ...

  16. CLOSING MACULAR HOLES WITH "MACULAR PLUG" WITHOUT GAS TAMPONADE AND POSTOPERATIVE POSTURING.

    Science.gov (United States)

    Chakrabarti, Meena; Benjamin, Preethi; Chakrabarti, Keya; Chakrabarti, Arup

    2017-03-01

    To investigate the surgical results of macular hole surgery without gas tamponade or postoperative posturing in patients with Stage 3 and Stage 4 macular holes with ≥500 μm mean base diameter. Retrospective interventional case series. Twenty-six patients with Stage 3 and Stage 4 macular holes. Twenty-six eyes of 26 patients with Stage 3 and Stage 4 macular holes and a mean base diameter of 892.8 ± 349 μm underwent pars plana 23-gauge vitrectomy with broad internal limiting membrane peel (ILM peel), inverted ILM flap repositioning (ILMR), and use of autologous gluconated blood clumps as a macular plug to close the macular hole. No fluid-air exchange, endotamponade, or postoperative posturing was used. The subjects were followed up for 12 months. The anatomical outcome of the procedure was evaluated by fundus examination and optical coherence tomography. Spectral domain optical coherence tomography was used to study the restoration of the outer retinal layer integrity in the postoperative period. The preoperative and postoperative best-corrected visual acuities in logMAR units were compared to evaluate functional outcome. Macular hole closure and best-corrected visual acuity before and after surgery. Twenty-six patients with mean age 62.8 ± 7.3 years, preoperative median best-corrected visual acuity 6/60 (1.0 logMAR units), and a mean base diameter of 892.8 ± 349 μm underwent surgery to close macular holes without gas tamponade or postoperative posturing. Twenty patients (76.9%) were phakic. Twenty eyes (76.92%) had Stage 3 macular holes and 6 eyes (23.10%) had Stage 4 macular holes. After a single surgery, hole closure was achieved in 100% of eyes. The median best-corrected visual acuity improved from 6/60 (1.0 logMAR units) to 6/18 (0.50 logMAR units) (P hole closure with statically significant functional improvement for large Stage 3 and Stage 4 macular holes.

  17. Irradiation performance of PFBR MOX fuel after 112 GWd/t burn-up

    Energy Technology Data Exchange (ETDEWEB)

    Venkiteswaran, C.N., E-mail: cnv@igcar.gov.in; Jayaraj, V.V.; Ojha, B.K.; Anandaraj, V.; Padalakshmi, M.; Vinodkumar, S.; Karthik, V.; Vijaykumar, Ran; Vijayaraghavan, A.; Divakar, R.; Johny, T.; Joseph, Jojo; Thirunavakkarasu, S.; Saravanan, T.; Philip, John; Rao, B.P.C.; Kasiviswanathan, K.V.; Jayakumar, T.

    2014-06-01

    The 500 MWe Prototype Fast Breeder Reactor (PFBR) which is in advanced stage of construction at Kalpakkam, India, will use mixed oxide (MOX) fuel with a target burnup of 100 GWd/t. The fuel pellet is of annular design to enable operation at a peak linear power of 450 W/cm with the requirement of minimum duration of pre-conditioning. The performance of the MOX fuel and the D9 clad and wrapper material was assessed through Post Irradiation Examinations (PIE) after test irradiation of 37 fuel pin subassembly in Fast Breeder Test Reactor (FBTR) to a burn-up of 112 GWd/t. Fission product distribution, swelling and fuel–clad gap evolution, central hole diameter variation, restructuring, fission gas release and clad wastage due to fuel–clad chemical interaction were evaluated through non-destructive and destructive examinations. The examinations have indicated that the MOX fuel can safely attain the desired target burn-up in PFBR.

  18. In-situ burning of heavy oils and Orimulsion : mid-scale burns

    International Nuclear Information System (INIS)

    Fingas, M.F.; Fieldhouse, B.; Brown, C.E.; Gamble, L.

    2004-01-01

    In-situ burning is considered to be a viable means to clean oil spills on water. In-situ burning, when performed under the right conditions, can reduce the volume of spilled oil and eliminate the need to collect, store, transport and dispose of the recovered oil. This paper presented the results of bench-scale in-situ burning tests in which Bunker C, Orimulsion and weathered bitumen were burned outdoors during the winter in burn pans of approximately 1 square metre. Each test was conducted on salt water which caused the separation of the bitumen from the water in the Orimulsion. Small amounts of diesel fuel was used to ignite the heavy oils. Quantitative removal of the fuels was achieved in all cases, but re-ignition was required for the Orimulsion. Maximum efficiency was in the order of 70 per cent. The residue was mostly asphaltenes and resins which cooled to a solid, glass like material that could be readily removed. The study showed that the type of oil burned influences the behaviour of the burns. Bunker C burned quite well and Orimulsion burned efficiently, but re-ignition was necessary. It was concluded that there is potential for burning heavy oils of several types in-situ. 6 refs., 7 tabs., 18 figs

  19. Assessing burn depth in tattooed burn lesions with LASCA Imaging

    Science.gov (United States)

    Krezdorn, N.; Limbourg, A.; Paprottka, F.J.; Könneker; Ipaktchi, R.; Vogt, P.M

    2016-01-01

    Summary Tattoos are on the rise, and so are patients with tattooed burn lesions. A proper assessment with regard to burn depth is often impeded by the tattoo dye. Laser speckle contrast analysis (LASCA) is a technique that evaluates burn lesions via relative perfusion analysis. We assessed the effect of tattoo skin pigmentation on LASCA perfusion imaging in a multicolour tattooed patient. Depth of burn lesions in multi-coloured tattooed and untattooed skin was assessed using LASCA. Relative perfusion was measured in perfusion units (PU) and compared to various pigment colours, then correlated with the clinical evaluation of the lesion. Superficial partial thickness burn (SPTB) lesions showed significantly elevated perfusion units (PU) compared to normal skin; deep partial thickness burns showed decreased PU levels. PU of various tattoo pigments to normal skin showed either significantly lower values (blue, red, pink) or significantly increased values (black) whereas orange and yellow pigment showed values comparable to normal skin. In SPTB, black and blue pigment showed reduced perfusion; yellow pigment was similar to normal SPTB burn. Deep partial thickness burn (DPTB) lesions in tattoos did not show significant differences to normal DPTB lesions for black, green and red. Tattoo pigments alter the results of perfusion patterns assessed with LASCA both in normal and burned skin. Yellow pigments do not seem to interfere with LASCA assessment. However proper determination of burn depth both in SPTB and DPTB by LASCA is limited by the heterogenic alterations of the various pigment colours. PMID:28149254

  20. Satisfaction with life after burn: A Burn Model System National Database Study.

    Science.gov (United States)

    Goverman, J; Mathews, K; Nadler, D; Henderson, E; McMullen, K; Herndon, D; Meyer, W; Fauerbach, J A; Wiechman, S; Carrougher, G; Ryan, C M; Schneider, J C

    2016-08-01

    While mortality rates after burn are low, physical and psychosocial impairments are common. Clinical research is focusing on reducing morbidity and optimizing quality of life. This study examines self-reported Satisfaction With Life Scale scores in a longitudinal, multicenter cohort of survivors of major burns. Risk factors associated with Satisfaction With Life Scale scores are identified. Data from the National Institute on Disability, Independent Living, and Rehabilitation Research (NIDILRR) Burn Model System (BMS) database for burn survivors greater than 9 years of age, from 1994 to 2014, were analyzed. Demographic and medical data were collected on each subject. The primary outcome measures were the individual items and total Satisfaction With Life Scale (SWLS) scores at time of hospital discharge (pre-burn recall period) and 6, 12, and 24 months after burn. The SWLS is a validated 5-item instrument with items rated on a 1-7 Likert scale. The differences in scores over time were determined and scores for burn survivors were also compared to a non-burn, healthy population. Step-wise regression analysis was performed to determine predictors of SWLS scores at different time intervals. The SWLS was completed at time of discharge (1129 patients), 6 months after burn (1231 patients), 12 months after burn (1123 patients), and 24 months after burn (959 patients). There were no statistically significant differences between these groups in terms of medical or injury demographics. The majority of the population was Caucasian (62.9%) and male (72.6%), with a mean TBSA burned of 22.3%. Mean total SWLS scores for burn survivors were unchanged and significantly below that of a non-burn population at all examined time points after burn. Although the mean SWLS score was unchanged over time, a large number of subjects demonstrated improvement or decrement of at least one SWLS category. Gender, TBSA burned, LOS, and school status were associated with SWLS scores at 6 months

  1. Active galactic nucleus black hole mass estimates in the era of time domain astronomy

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Brandon C.; Treu, Tommaso; Pancoast, Anna [Department of Physics, Broida Hall, University of California, Santa Barbara, CA 93106-9530 (United States); Malkan, Matthew [Department of Astronomy, 430 Portola Plaza, Box 951547, University of California, Los Angeles, CA 90095-1547 (United States); Woo, Jong-Hak [Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of)

    2013-12-20

    We investigate the dependence of the normalization of the high-frequency part of the X-ray and optical power spectral densities (PSDs) on black hole mass for a sample of 39 active galactic nuclei (AGNs) with black hole masses estimated from reverberation mapping or dynamical modeling. We obtained new Swift observations of PG 1426+015, which has the largest estimated black hole mass of the AGNs in our sample. We develop a novel statistical method to estimate the PSD from a light curve of photon counts with arbitrary sampling, eliminating the need to bin a light curve to achieve Gaussian statistics, and we use this technique to estimate the X-ray variability parameters for the faint AGNs in our sample. We find that the normalization of the high-frequency X-ray PSD is inversely proportional to black hole mass. We discuss how to use this scaling relationship to obtain black hole mass estimates from the short timescale X-ray variability amplitude with precision ∼0.38 dex. The amplitude of optical variability on timescales of days is also anticorrelated with black hole mass, but with larger scatter. Instead, the optical variability amplitude exhibits the strongest anticorrelation with luminosity. We conclude with a discussion of the implications of our results for estimating black hole mass from the amplitude of AGN variability.

  2. Understanding the build-up of supermassive black holes and galaxies

    Science.gov (United States)

    Carrera, Francisco; Ueda, Yoshihiro; Georgakakis, Antonis

    2016-07-01

    One of the main open questions in modern Astrophysics is understanding the coupled growth of supermassive black holes by accretion and their host galaxies via star formation, from their peak at redshifts z~ 1-4 to the present time. The generic scenario proposed involves an early phase of intense black hole growth that takes place behind large obscuring columns of inflowing dust and gas clouds. It is postulated that this is followed by a blow-out stage during which some form of AGN feedback controls the fate of the interstellar medium and hence, the evolution of the galaxy. X-rays are essential for testing this scenario as they uniquely probe AGN at both the early heavily obscured stage and the later blow-out phase. X-ray spectral analysis can identify the smoking gun evidence of heavily obscured black hole growth (e.g. intense iron Kalpha line). It therefore provides the most robust method for compiling clean samples of deeply shrouded AGN with well-defined selection functions and unbiased determinations of their intrinsic properties (accretion luminosity, obscuring column). X-rays are also the best window for studying in detail AGN feedback. This process ultimately originates in the innermost regions close to the supermassive black hole and is dominated, in terms of energy and mass flux, by highly ionisedmaterial that remains invisible at other wavelengths. The most important epoch for investigating the relation between AGN and galaxies is the redshift range z~1-4, when most black holes and stars we see in the present-day Universe were put in place. Unfortunately, exhaustive efforts with current high-energy telescopes only scrape the tip of the iceberg of the most obscured AGN population. Moreover, Xray studies of the incidence, nature and energetics of AGN feedback are limited to the local Universe. The Athena observatory will provide the technological leap required for a breakthrough in our understanding of AGN and galaxy evolution at the heyday of the Universe

  3. Burning issues

    International Nuclear Information System (INIS)

    Raloff, J.

    1993-01-01

    The idea of burning oil slicks at sea has intrigued oil-cleanup managers for more than a decade, but it wasn't until the advent of fireproof booms in the mid-1980's and a major spill opportunity (the March 1989 Exxon Valdez) that in-situ burning got a real sea trial. The results of this and other burning experiments indicate that, when conditions allow it, nothing can compete with fire's ability to remove oil from water. Burns have the potential to remove as much oil in one day as mechanical devices can in one month, along with minimal equipment, labor and cost. Reluctance to burn in appropriate situations comes primarily from the formation of oily, black smoke. Analysis of the potentially toxic gases have been done, indicating that burning will not increase the levels of polluting aldehydes, ketones, dioxins, furans, and PAHs above those that normally evaporate from spilled oil. This article contains descriptions of planned oil fires and the discussion on the advantages and concerns of such a policy

  4. 30 CFR 817.87 - Coal mine waste: Burning and burned waste utilization.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Coal mine waste: Burning and burned waste...-UNDERGROUND MINING ACTIVITIES § 817.87 Coal mine waste: Burning and burned waste utilization. (a) Coal mine... extinguishing operations. (b) No burning or unburned coal mine waste shall be removed from a permitted disposal...

  5. Black hole astrophysics

    International Nuclear Information System (INIS)

    Blandford, R.D.; Thorne, K.S.

    1979-01-01

    Following an introductory section, the subject is discussed under the headings: on the character of research in black hole astrophysics; isolated holes produced by collapse of normal stars; black holes in binary systems; black holes in globular clusters; black holes in quasars and active galactic nuclei; primordial black holes; concluding remarks on the present state of research in black hole astrophysics. (U.K.)

  6. Beyond the standard model of the disc-line spectral profiles from black hole accretion discs

    Czech Academy of Sciences Publication Activity Database

    Sochora, Vjačeslav; Karas, Vladimír; Svoboda, Jiří; Dovčiak, Michal

    2014-01-01

    Roč. 54, č. 4 (2014), s. 301-304 ISSN 1210-2709 R&D Projects: GA ČR(CZ) GC13-00070J Institutional support: RVO:67985815 Keywords : accretion discs * black hole physics * galactic nuclei Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  7. SHORT-PULSE ELECTROMAGNETIC TRANSPONDER FOR HOLE-TO-HOLE USE.

    Science.gov (United States)

    Wright, David L.; Watts, Raymond D.; Bramsoe, Erik

    1983-01-01

    Hole-to-hole observations were made through nearly 20 m of granite using an electromagnetic transponder (an active reflector) in one borehole and a single-hole short-pulse radar in another. The transponder is inexpensive, operationally simple, and effective in extending the capability of a short-pulse borehole radar system to allow hole-to-hole operation without requiring timing cables. A detector in the transponder senses the arrival of each pulse from the radar. Each pulse detection triggers a kilovolt-amplitude pulse for retransmission. The transponder 'echo' may be stronger than that of a passive reflector by a factor of as much as 120 db. The result is an increase in range capability by a factor which depends on attenuation in the medium and hole-to-hole wavepath geometry.

  8. The slightly-enriched spectral shift control reactor

    International Nuclear Information System (INIS)

    Martin, W.R.; Lee, J.C.; Edlund, M.C.

    1990-06-01

    An advanced converter reactor design utilizing mechanical spectral shift control rods in a conventional pressurized water reactor configuration is under investigation. The design is based on the principle that a harder spectrum during the early part of the fuel cycle will result in larger neutron captures in fertile 238 U, which can then be burned in situ in a softer spectrum later in the cycle. Preliminary design calculations performed during FY 89 show that the slightly-enriched spectral shift reactor design offers the benefit of substantially increased fuel resource utilization with the proven safety characteristics of the pressurized water reactor technology retained. Optimization of the fuel design and development of fuel management strategies have been carried out in FY 90, along with effort to develop and validate neutronic methodology for tight-lattice configurations with hard spectra. During FY 91, the final year of the grant, effort will focus on performing the final design calculations and continuing the research to develop improved methods for tight lattice analysis

  9. Global Burned Area and Biomass Burning Emissions from Small Fires

    Science.gov (United States)

    Randerson, J. T.; Chen, Y.; vanderWerf, G. R.; Rogers, B. M.; Morton, D. C.

    2012-01-01

    In several biomes, including croplands, wooded savannas, and tropical forests, many small fires occur each year that are well below the detection limit of the current generation of global burned area products derived from moderate resolution surface reflectance imagery. Although these fires often generate thermal anomalies that can be detected by satellites, their contributions to burned area and carbon fluxes have not been systematically quantified across different regions and continents. Here we developed a preliminary method for combining 1-km thermal anomalies (active fires) and 500 m burned area observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) to estimate the influence of these fires. In our approach, we calculated the number of active fires inside and outside of 500 m burn scars derived from reflectance data. We estimated small fire burned area by computing the difference normalized burn ratio (dNBR) for these two sets of active fires and then combining these observations with other information. In a final step, we used the Global Fire Emissions Database version 3 (GFED3) biogeochemical model to estimate the impact of these fires on biomass burning emissions. We found that the spatial distribution of active fires and 500 m burned areas were in close agreement in ecosystems that experience large fires, including savannas across southern Africa and Australia and boreal forests in North America and Eurasia. In other areas, however, we observed many active fires outside of burned area perimeters. Fire radiative power was lower for this class of active fires. Small fires substantially increased burned area in several continental-scale regions, including Equatorial Asia (157%), Central America (143%), and Southeast Asia (90%) during 2001-2010. Globally, accounting for small fires increased total burned area by approximately by 35%, from 345 Mha/yr to 464 Mha/yr. A formal quantification of uncertainties was not possible, but sensitivity

  10. Black Hole Paradox Solved By NASA's Chandra

    Science.gov (United States)

    2006-06-01

    . Using Chandra, Miller and his team provided crucial evidence for the role of magnetic forces in the black hole accretion process. The X-ray spectrum, the number of X-rays at different energies, showed that the speed and density of the wind from J1655's disk corresponded to computer simulation predictions for magnetically-driven winds. The spectral fingerprint also ruled out the two other major competing theories to winds driven by magnetic fields. "In 1973, theorists came up with the idea that magnetic fields could drive the generation of light by gas falling onto black holes," said co-author John Raymond of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. "Now, over 30 years later, we finally may have convincing evidence." Evidence for Wind in the GRO J1655-40 Spectrum Evidence for Wind in the GRO J1655-40 Spectrum This deeper understanding of how black holes accrete matter also teaches astronomers about other properties of black holes, including how they grow. "Just as a doctor wants to understand the causes of an illness and not merely the symptoms, astronomers try to understand what causes phenomena they see in the Universe," said co-author Danny Steeghs also of the Harvard-Smithsonian Center for Astrophysics. "By understanding what makes material release energy as it falls onto black holes, we may also learn how matter falls onto other important objects." In addition to accretion disks around black holes, magnetic fields may play an important role in disks detected around young sun-like stars where planets are forming, as well as ultra-dense objects called neutron stars. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center, Cambridge, Mass. Additional information and images can be found at: http://chandra.harvard.edu and http://chandra.nasa.gov

  11. Black holes

    OpenAIRE

    Brügmann, B.; Ghez, A. M.; Greiner, J.

    2001-01-01

    Recent progress in black hole research is illustrated by three examples. We discuss the observational challenges that were met to show that a supermassive black hole exists at the center of our galaxy. Stellar-size black holes have been studied in x-ray binaries and microquasars. Finally, numerical simulations have become possible for the merger of black hole binaries.

  12. Burn mouse models

    DEFF Research Database (Denmark)

    Calum, Henrik; Høiby, Niels; Moser, Claus

    2014-01-01

    Severe thermal injury induces immunosuppression, involving all parts of the immune system, especially when large fractions of the total body surface area are affected. An animal model was established to characterize the burn-induced immunosuppression. In our novel mouse model a 6 % third-degree b......Severe thermal injury induces immunosuppression, involving all parts of the immune system, especially when large fractions of the total body surface area are affected. An animal model was established to characterize the burn-induced immunosuppression. In our novel mouse model a 6 % third...... with infected burn wound compared with the burn wound only group. The burn mouse model resembles the clinical situation and provides an opportunity to examine or develop new strategies like new antibiotics and immune therapy, in handling burn wound victims much....

  13. Intensification process of air-hydrogen mixture burning in the variable cross section channel by means of the air jet

    Science.gov (United States)

    Zamuraev, V. P.; Kalinina, A. P.

    2018-03-01

    The paper presents the results of numerical modeling of a transonic region formation in the flat channel. Hydrogen flows into the channel through the holes in the wall. The jet of compressed air is localized downstream the holes. The transonic region formation is formed by the burning of heterogeneous hydrogen-air mixture. It was considered in the framework of the simplified chemical kinetics. The interesting feature of the regime obtained is the following: the distribution of the Mach numbers is qualitatively similar to the case of pulse-periodic energy sources. This mode is a favorable prerequisite for the effective fuel combustion in the expanding part of the channel when injecting fuel into this part.

  14. Development of continuous energy Monte Carlo burn-up calculation code MVP-BURN

    International Nuclear Information System (INIS)

    Okumura, Keisuke; Nakagawa, Masayuki; Sasaki, Makoto

    2001-01-01

    Burn-up calculations based on the continuous energy Monte Carlo method became possible by development of MVP-BURN. To confirm the reliably of MVP-BURN, it was applied to the two numerical benchmark problems; cell burn-up calculations for High Conversion LWR lattice and BWR lattice with burnable poison rods. Major burn-up parameters have shown good agreements with the results obtained by a deterministic code (SRAC95). Furthermore, spent fuel composition calculated by MVP-BURN was compared with measured one. Atomic number densities of major actinides at 34 GWd/t could be predicted within 10% accuracy. (author)

  15. Bacterial infections in burn patients at a burn hospital in Iran.

    Science.gov (United States)

    Ekrami, Alireza; Kalantar, Enayat

    2007-12-01

    The major challenge for a burn team is nosocomial infection in burn patients, which is known to cause over 50% of burn deaths. Most studies on infection in burn patients focus on burn wound infection, whereas other nosocomial infections in these patients are not well described. We undertook this study to determine three types of nosocomial infections viz., burn wound infection, urinary tract infection, and blood stream infection in burn patients in a burn hospital in Iran. During the one year period (May 2003 to April 2004), 182 patients were included in this study. Blood, urine and wound biopsy samples were taken 7 and 14 days after admission to Taleghani Burn hospital. Isolation and identification of microorganisms was done using the standard procedure. Disk diffusion test were performed for all the isolates for antimicrobial susceptibility. Of the 182 patients, 140 (76.9%) acquired at least one type of infection of the 140, 116 patients (82.8%) were culture positive on day 7 while 24 (17.2%) on 14 days after admission. Primary wound infection was most common (72.5%), followed by blood stream (18.6%) and urinary tract infections (8.9 %). The microorganisms causing infections were Pseudomonas aeruginosa (37.5%), Staphylococcus aureus (20.2%), and Acinetobacter baumanni (10.4%). Among these isolates P. aeruginosa was found to be 100 per cent resistant to amikacin, gentamicin , carbenicillin, ciprofloxacin, tobramycin and ceftazidime; 58 per cent of S. aureus and 60 per cent of coagulase negative Staphylococcus were methicillin resistant. High prevalence of nosocomial infections and the presence of multidrug resistant bacteria, and methicillin resistant S. aureus in patients at Taleghani Burn Hospital suggest continuous surveillance of burn infections and develop strategies for antimicrobial resistance control and treatment of infectious complications.

  16. Comparing the reported burn conditions for different severity burns in porcine models: a systematic review.

    Science.gov (United States)

    Andrews, Christine J; Cuttle, Leila

    2017-12-01

    There are many porcine burn models that create burns using different materials (e.g. metal, water) and different burn conditions (e.g. temperature and duration of exposure). This review aims to determine whether a pooled analysis of these studies can provide insight into the burn materials and conditions required to create burns of a specific severity. A systematic review of 42 porcine burn studies describing the depth of burn injury with histological evaluation is presented. Inclusion criteria included thermal burns, burns created with a novel method or material, histological evaluation within 7 days post-burn and method for depth of injury assessment specified. Conditions causing deep dermal scald burns compared to contact burns of equivalent severity were disparate, with lower temperatures and shorter durations reported for scald burns (83°C for 14 seconds) compared to contact burns (111°C for 23 seconds). A valuable archive of the different mechanisms and materials used for porcine burn models is presented to aid design and optimisation of future models. Significantly, this review demonstrates the effect of the mechanism of injury on burn severity and that caution is recommended when burn conditions established by porcine contact burn models are used by regulators to guide scald burn prevention strategies. © 2017 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  17. Neutrino constraints that transform black holes into grey holes

    International Nuclear Information System (INIS)

    Ruderfer, M.

    1982-01-01

    Existing black hole theory is found to be defective in its neglect of the physical properties of matter and radiation at superhigh densities. Nongravitational neutrino effects are shown to be physically relevant to the evolution of astronomical black holes and their equations of state. Gravitational collapse to supernovae combined with the Davis and Ray vacuum solution for neutrinos limit attainment of a singularity and require black holes to evolve into ''grey holes''. These allow a better justification than do black holes for explaining the unique existence of galactic masses. (Auth.)

  18. X-ray Polarization from Black Holes: GEMS Scientific White Paper

    OpenAIRE

    Schnittman, Jeremy; Angelini, Lorella; Baring, Matthew; Baumgartner, Wayne; Black, Kevin; Dotson, Jessie; Ghosh, Pranab; Harding, Alice; Hill, Joanne; Jahoda, Keith; Kaaret, Phillip; Kallman, Tim; Krawczynski, Henric; Krolik, Julian; Lai, Dong

    2013-01-01

    We present here a summary of the scientific goals behind the Gravity and Extreme Magnetism SMEX (GEMS) X-ray polarimetry mission's black hole (BH) observing program. The primary targets can be divided into two classes: stellar-mass galactic BHs in accreting binaries, and super-massive BHs in the centers of active galactic nuclei (AGN). The stellar-mass BHs can in turn be divided into various X-ray spectral states: thermal-dominant (disk), hard (radio jet), and steep power-law (hot corona). Th...

  19. Primordial black holes from passive density fluctuations

    International Nuclear Information System (INIS)

    Lin, Chia-Min; Ng, Kin-Wang

    2013-01-01

    In this Letter, we show that if passive fluctuations are considered, primordial black holes (PBHs) can be easily produced in the framework of single-field, slow-roll inflation models. The formation of PBHs is due to the blue spectrum of passive fluctuations and an enhancement of the spectral range which exits horizon near the end of inflation. Therefore the PBHs are light with masses ≲10 15 g depending on the number of e-folds when the scale of our observable universe leaves horizon. These PBHs are likely to have evaporated and cannot be a candidate for dark matter but they may still affect the early universe.

  20. THE AKARI 2.5-5.0 μm SPECTRAL ATLAS OF TYPE-1 ACTIVE GALACTIC NUCLEI: BLACK HOLE MASS ESTIMATOR, LINE RATIO, AND HOT DUST TEMPERATURE

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dohyeong; Im, Myungshin; Kim, Ji Hoon; Jun, Hyunsung David; Lee, Seong-Kook [Center for the Exploration of the Origin of the Universe (CEOU), Astronomy Program, Department of Physics and Astronomy, Seoul National University, Shillim-Dong, Kwanak-Gu, Seoul 151-742 (Korea, Republic of); Woo, Jong-Hak; Lee, Hyung Mok; Lee, Myung Gyoon [Astronomy Program, Department of Physics and Astronomy, Seoul National University, Shillim-Dong, Kwanak-Gu, Seoul 151-742 (Korea, Republic of); Nakagawa, Takao; Matsuhara, Hideo; Wada, Takehiko; Takagi, Toshinobu [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Kanagawa 252-5210 (Japan); Oyabu, Shinki [Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602 (Japan); Ohyama, Youichi, E-mail: dohyeong@astro.snu.ac.kr, E-mail: mim@astro.snu.ac.kr [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 106, Taiwan (China)

    2015-01-01

    We present 2.5-5.0 μm spectra of 83 nearby (0.002 < z < 0.48) and bright (K < 14 mag) type-1 active galactic nuclei (AGNs) taken with the Infrared Camera on board AKARI. The 2.5-5.0 μm spectral region contains emission lines such as Brβ (2.63 μm), Brα (4.05 μm), and polycyclic aromatic hydrocarbons (3.3 μm), which can be used for studying the black hole (BH) masses and star formation activity in the host galaxies of AGNs. The spectral region also suffers less dust extinction than in the ultra violet (UV) or optical wavelengths, which may provide an unobscured view of dusty AGNs. Our sample is selected from bright quasar surveys of Palomar-Green and SNUQSO, and AGNs with reverberation-mapped BH masses from Peterson et al. Using 11 AGNs with reliable detection of Brackett lines, we derive the Brackett-line-based BH mass estimators. We also find that the observed Brackett line ratios can be explained with the commonly adopted physical conditions of the broad line region. Moreover, we fit the hot and warm dust components of the dust torus by adding photometric data of SDSS, 2MASS, WISE, and ISO to the AKARI spectra, finding hot and warm dust temperatures of ∼1100 K and ∼220 K, respectively, rather than the commonly cited hot dust temperature of 1500 K.

  1. Burning Mouth Syndrome

    Science.gov (United States)

    ... Care Home Health Info Health Topics Burning Mouth Burning Mouth Syndrome (BMS) is a painful, complex condition often described ... or other symptoms. Read More Publications Cover image Burning Mouth Syndrome Publication files Download Language English PDF — Number of ...

  2. Discovery and Evolution of the New Black Hole Candidate Swift J1539.2-6227 During Its 2008 Outburst

    Science.gov (United States)

    Krimm, H. A.; Tomsick, J. A.; Markwardt, C. B.; Brocksopp, C.; Grise, F.; Kaaret, P.; Romano, P.

    2010-01-01

    We report on the discovery by the Swift Gamma-Ray Burst Explorer of the black hole candidate Swift J1539.2-6227 and the subsequent course of an outburst beginning in November 2008 and lasting at least seven months. The source was discovered during normal observations with the Swift Burst Alert Telescope (BAT) on 2008 November 25. An extended observing campaign with the Rossi X-Ray Timing Explorer (RXTE) and Swift provided near-daily coverage over 176 days, giving us a rare opportunity to track the evolution of spectral and timing parameters with fine temporal resolution through a series of spectral states. The source was first detected in a hard state during which strong low-frequency quasiperiodic oscillations (QPOs) were detected. The QPOs persisted for about 35 days and a signature of the transition from the hard to soft intermediate states was seen in the timing data. The source entered a short-lived thermal state about 40 days after the start of the outburst. There were variations in spectral hardness as the source flux declined and returned to a hard state at the end of the outburst. The progression of spectral states and the nature of the timing features provide strong evidence that Swift J1539.2-6227 is a candidate black hole in a low-mass X-ray binary system.

  3. Nucleon scattering on one-hole nuclei in the framework of the continuum RPA

    International Nuclear Information System (INIS)

    Abdi, S.M.

    1979-01-01

    It is shown that the scattering transition amplitude for nucleon-nucleus scattering on one-hole nuclei can be directly related to so-called linear response function. The theory of the linear response function is formulated in the framework of Greens functions. The linear response function obreys an equation of Bethe-Salpeter-type. From to the spectral decomposition of the response function one can deduce, that the knowledge of the response function in equivalent to the knowledge of the so-called 'particle-hole'- and 'hole-particle'-amplitudes, respectively, and the exitation energies of the compound A-particle system. In this work the binding- and resonance energies for 16 O and 16 N, respectively, have been calculated, which are needed for the scattering processes 15 N(p,n) 15 O and 15 N(n,n') 15 N, respectively. For low energies the agreement with experiment is not statisfactory, probably due to the coupling to 3p-3h-states, which was neglected in the treatment. (orig./HSI) [de

  4. Black-hole Binaries: Life Begins at 40 keV

    Science.gov (United States)

    Belloni, Tomaso M.; Motta, Sara

    2009-05-01

    In the study of black-hole transients, an important problem that still needs to be answered is how the high-energy part of the spectrum evolves from the low-hard to the high-soft state, given that they have very different properties. Recent results obtained with RXTE and INTEGRAL have given inconsistent results. With RXTE, we have found that the high-energy cutoff in GX 339-4 during the transition first decreases (during the low-hard state), then increases again across the Hard-Intermediate state, to become unmeasurable in the soft states (possibly because of statistical limitations). We show Simbol-X will be able to determine the spectral shape with superb accuracy. As the high-energy part of the spectrum is relatively less known than the one below 20 keV, Simbol-X will provide important results that will help out understanding of the extreme physical conditions in the vicinity of a stellar-mass black hole.

  5. Full Core Burn-up Calculation at JRR-3 with MVP-BURN

    International Nuclear Information System (INIS)

    Komeda, Masao; Yamamoto, Kazuyoshi; Kusunoki, Tsuyoshi

    2008-01-01

    Research reactors use a burnable poison to suppress an excess reactivity in the beginning of reactor lifetime. The JRR-3 (Japan Research Reactor No.3) has used cadmium wires of radius 0.02 cm as a burnable poison. This report describes burn-up calculations of plate fuel models and full core models with MVP-BURN, which is a burn-up calculation code using Monte Carlo method and has been developed in JAEA (Japan Atomic Energy Agency). As the results of calculations of plate models, between a model composed of one burn-up region along the radius direction and a model composed of a few burn-up regions along the radius direction, the effective absorption cross section of 113 Cd has had different tendency on reaching approximate 40. day (10000 MWd/t). And as results of calculations of full core model, it has been indicated that k eff is almost same till approximate 80. day (22000 MWd/t) between a model composed of one burn-up region along the vertical direction and a model composed of a few burn-up regions along the vertical direction. However difference of 113 Cd burn-up becomes pronounced and each k eff makes a difference after 80. day. (authors)

  6. Circular geodesic of Bardeen and Ayon-Beato-Garcia regular black-hole and no-horizon spacetimes

    Science.gov (United States)

    Stuchlík, Zdeněk; Schee, Jan

    2015-12-01

    In this paper, we study circular geodesic motion of test particles and photons in the Bardeen and Ayon-Beato-Garcia (ABG) geometry describing spherically symmetric regular black-hole or no-horizon spacetimes. While the Bardeen geometry is not exact solution of Einstein's equations, the ABG spacetime is related to self-gravitating charged sources governed by Einstein's gravity and nonlinear electrodynamics. They both are characterized by the mass parameter m and the charge parameter g. We demonstrate that in similarity to the Reissner-Nordstrom (RN) naked singularity spacetimes an antigravity static sphere should exist in all the no-horizon Bardeen and ABG solutions that can be surrounded by a Keplerian accretion disc. However, contrary to the RN naked singularity spacetimes, the ABG no-horizon spacetimes with parameter g/m > 2 can contain also an additional inner Keplerian disc hidden under the static antigravity sphere. Properties of the geodesic structure are reflected by simple observationally relevant optical phenomena. We give silhouette of the regular black-hole and no-horizon spacetimes, and profiled spectral lines generated by Keplerian rings radiating at a fixed frequency and located in strong gravity region at or nearby the marginally stable circular geodesics. We demonstrate that the profiled spectral lines related to the regular black-holes are qualitatively similar to those of the Schwarzschild black-holes, giving only small quantitative differences. On the other hand, the regular no-horizon spacetimes give clear qualitative signatures of their presence while compared to the Schwarschild spacetimes. Moreover, it is possible to distinguish the Bardeen and ABG no-horizon spacetimes, if the inclination angle to the observer is known.

  7. Educational Materials - Burn Wise

    Science.gov (United States)

    Burn Wise outreach material. Burn Wise is a partnership program of that emphasizes the importance of burning the right wood, the right way, in the right wood-burning appliance to protect your home, health, and the air we breathe.

  8. Spectral composition of shortwave radiation reflected and deep penetrating into snow near the Barentsburg settlement (Svalbard

    Directory of Open Access Journals (Sweden)

    P. N. Svyashchennikov

    2015-01-01

    Full Text Available Data on spectral composition of shortwave radiation that is reflected from snow and penetrates deep into the snow cover obtained near the Barentsburg settlement (Svalbard are discussed in the paper. Measurements were made by the use of the spectral radiometer TriOS Ramses within the wavelength range of 280–950 nm. The results will allow more proper taking account of the anthropogenic pollution effects on the radiative properties of snow cover under conditions of industrial activity related to the coal extraction and burning in Barentsburg.

  9. Analysis and Assessment of the Spatial and Temporal Distribution of Burned Areas in the Amazon Forest

    Directory of Open Access Journals (Sweden)

    Francielle da Silva Cardozo

    2014-08-01

    Full Text Available The objective of this study was to analyze the spatial and temporal distribution of burned areas in Rondônia State, Brazil during the years 2000 to 2011 and evaluate the burned area maps. A Linear Spectral Mixture Model (LSMM was applied to MODIS surface reflectance images to originate the burned areas maps, which were validated with TM/Landsat 5 and ETM+/Landsat 7 images and field data acquired in August 2013. The validation presented a correlation ranging from 67% to 96% with an average value of 86%. The lower correlation values are related to the distinct spatial resolutions of the MODIS and TM/ETM+ sensors because small burn scars are not detected in MODIS images and higher spatial correlations are related to the presence of large fires, which are better identified in MODIS, increasing the accuracy of the mapping methodology. In addition, the 12-year burned area maps of Rondônia indicate that fires, as a general pattern, occur in areas that have already been converted to some land use, such as vegetal extraction, large animal livestock areas or diversified permanent crops. Furthermore, during the analyzed period, land use conversion associated with climatic events significantly influenced the occurrence of fire in Rondônia and amplified its impacts.

  10. Semiconducting Polymer Photodetectors with Electron and Hole Blocking Layers: High Detectivity in the Near-Infrared

    Directory of Open Access Journals (Sweden)

    Xiong Gong

    2010-07-01

    Full Text Available Sensing from the ultraviolet-visible to the infrared is critical for a variety of industrial and scientific applications. Photodetectors with broad spectral response, from 300 nm to 1,100 nm, were fabricated using a narrow-band gap semiconducting polymer blended with a fullerene derivative. By using both an electron-blocking layer and a hole-blocking layer, the polymer photodetectors, operating at room temperature, exhibited calculated detectivities greater than 1013 cm Hz1/2/W over entire spectral range with linear dynamic range approximately 130 dB. The performance is comparable to or even better than Si photodetectors.

  11. Primary black holes

    International Nuclear Information System (INIS)

    Novikov, I.; Polnarev, A.

    1981-01-01

    Proves are searched for of the formation of the so-called primary black holes at the very origin of the universe. The black holes would weigh less than 10 13 kg. The formation of a primary black hole is conditional on strong fluctuations of the gravitational field corresponding roughly to a half of the fluctuation maximally permissible by the general relativity theory. Only big fluctuations of the gravitational field can overcome the forces of the hot gas pressure and compress the originally expanding matter into a black hole. Low-mass black holes have a temperature exceeding that of the black holes formed from stars. A quantum process of particle formation, the so-called evaporation takes place in the strong gravitational field of a black hole. The lower the mass of the black hole, the shorter the evaporation time. The analyses of processes taking place during the evaporation of low-mass primary black holes show that only a very small proportion of the total mass of the matter in the universe could turn into primary black holes. (M.D.)

  12. Monitoring vegetation recovery in fire-affected areas using temporal profiles of spectral signal from time series MODIS and LANDSAT satellite images

    Science.gov (United States)

    Georgopoulou, Danai; Koutsias, Nikos

    2015-04-01

    Vegetation phenology is an important element of vegetation characteristics that can be useful in vegetation monitoring especially when satellite remote sensing observations are used. In that sense temporal profiles extracted from spectral signal of time series MODIS and LANDSAT satellite images can be used to characterize vegetation phenology and thus to be helpful for monitoring vegetation recovery in fire-affected areas. The aim of this study is to explore the vegetation recovery pattern of the catastrophic wildfires that occurred in Peloponnisos, southern Greece, in 2007. These fires caused the loss of 67 lives and were recognized as the most extreme natural disaster in the country's recent history. Satellite remote sensing data from MODIS and LANDSAT satellites in the period from 2000 to 2014 were acquired and processed to extract the temporal profiles of the spectral signal for selected areas within the fire-affected areas. This dataset and time period analyzed together with the time that these fires occurred gave the opportunity to create temporal profiles seven years before and seven years after the fire. The different scale of the data used gave us the chance to understand how vegetation phenology and therefore the recovery patterns are influenced by the spatial resolution of the satellite data used. Different metrics linked to key phenological events have been created and used to assess vegetation recovery in the fire-affected areas. Our analysis was focused in the main land cover types that were mostly affected by the 2007 wildland fires. Based on CORINE land-cover maps these were agricultural lands highly interspersed with large areas of natural vegetation followed by sclerophyllous vegetation, transitional woodland shrubs, complex cultivation patterns and olive groves. Apart of the use of the original spectral data we estimated and used vegetation indices commonly found in vegetation studies as well as in burned area mapping studies. In this study we

  13. From binary black hole simulation to triple black hole simulation

    International Nuclear Information System (INIS)

    Bai Shan; Cao Zhoujian; Han, Wen-Biao; Lin, Chun-Yu; Yo, Hwei-Jang; Yu, Jui-Ping

    2011-01-01

    Black hole systems are among the most promising sources for a gravitational wave detection project. Now, China is planning to construct a space-based laser interferometric detector as a follow-on mission of LISA in the near future. Aiming to provide some theoretical support to this detection project on the numerical relativity side, we focus on black hole systems simulation in this work. Considering the globular galaxy, multiple black hole systems also likely to exist in our universe and play a role as a source for the gravitational wave detector we are considering. We will give a progress report in this paper on our black hole system simulation. More specifically, we will present triple black hole simulation together with binary black hole simulation. On triple black hole simulations, one novel perturbational method is proposed.

  14. Reflection Spectra of the Black Hole Binary Candidate MAXI J1535-571 in the Hard State Observed by NuSTAR

    Science.gov (United States)

    Xu, Yanjun; Harrison, Fiona A.; García, Javier A.; Fabian, Andrew C.; Fürst, Felix; Gandhi, Poshak; Grefenstette, Brian W.; Madsen, Kristin K.; Miller, Jon M.; Parker, Michael L.; Tomsick, John A.; Walton, Dominic J.

    2018-01-01

    We report on a Nuclear Spectroscopic Telescope Array (NuSTAR) observation of the recently discovered bright black hole candidate MAXI J1535-571. NuSTAR observed the source on MJD 58003 (five days after the outburst was reported). The spectrum is characteristic of a black hole binary in the hard state. We observe clear disk reflection features, including a broad Fe Kα line and a Compton hump peaking around 30 keV. Detailed spectral modeling reveals a narrow Fe Kα line complex centered around 6.5 keV on top of the strong relativistically broadened Fe Kα line. The narrow component is consistent with distant reflection from moderately ionized material. The spectral continuum is well described by a combination of cool thermal disk photons and a Comptonized plasma with the electron temperature {{kT}}{{e}}=19.7+/- 0.4 keV. An adequate fit can be achieved for the disk reflection features with a self-consistent relativistic reflection model that assumes a lamp-post geometry for the coronal illuminating source. The spectral fitting measures a black hole spin a> 0.84, inner disk radius {R}{in}lamp-post height h={7.2}-2.0+0.8 {r}{{g}} (statistical errors, 90% confidence), indicating no significant disk truncation and a compact corona. Although the distance and mass of this source are not currently known, this suggests the source was likely in the brighter phases of the hard state during this NuSTAR observation.

  15. Phase transition for black holes with scalar hair and topological black holes

    International Nuclear Information System (INIS)

    Myung, Yun Soo

    2008-01-01

    We study phase transitions between black holes with scalar hair and topological black holes in asymptotically anti-de Sitter spacetimes. As the ground state solutions, we introduce the non-rotating BTZ black hole in three dimensions and topological black hole with hyperbolic horizon in four dimensions. For the temperature matching only, we show that the phase transition between black hole with scalar hair (Martinez-Troncoso-Zanelli black hole) and topological black hole is second-order by using differences between two free energies. However, we do not identify what order of the phase transition between scalar and non-rotating BTZ black holes occurs in three dimensions, although there exists a possible decay of scalar black hole to non-rotating BTZ black hole

  16. Massive Black Hole Implicated in Stellar Destruction

    Science.gov (United States)

    2010-01-01

    of Alabama who led the study. Irwin and his colleagues obtained optical spectra of the object using the Magellan I and II telescopes in Las Campanas, Chile. These data reveal emission from gas rich in oxygen and nitrogen but no hydrogen, a rare set of signals from globular clusters. The physical conditions deduced from the spectra suggest that the gas is orbiting a black hole of at least 1,000 solar masses. The abundant amount of oxygen and absence of hydrogen indicate that the destroyed star was a white dwarf, the end phase of a solar-type star that has burned its hydrogen leaving a high concentration of oxygen. The nitrogen seen in the optical spectrum remains an enigma. "We think these unusual signatures can be explained by a white dwarf that strayed too close to a black hole and was torn apart by the extreme tidal forces," said coauthor Joel Bregman of the University of Michigan. Theoretical work suggests that the tidal disruption-induced X-ray emission could stay bright for more than a century, but it should fade with time. So far, the team has observed there has been a 35% decline in X-ray emission from 2000 to 2008. The ULX in this study is located in NGC 1399, an elliptical galaxy about 65 million light years from Earth. Irwin presented these results at the 215th meeting of the American Astronomical Society in Washington, DC. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass. More information, including images and other multimedia, can be found at: http://chandra.harvard.edu and http://chandra.nasa.gov

  17. Black Holes

    OpenAIRE

    Townsend, P. K.

    1997-01-01

    This paper is concerned with several not-quantum aspects of black holes, with emphasis on theoretical and mathematical issues related to numerical modeling of black hole space-times. Part of the material has a review character, but some new results or proposals are also presented. We review the experimental evidence for existence of black holes. We propose a definition of black hole region for any theory governed by a symmetric hyperbolic system of equations. Our definition reproduces the usu...

  18. Deciding Where to Burn: Stakeholder Priorities for Prescribed Burning of a Fire-Dependent Ecosystem

    Directory of Open Access Journals (Sweden)

    Jennifer K. Costanza

    2011-03-01

    Full Text Available Multiagency partnerships increasingly work cooperatively to plan and implement fire management. The stakeholders that comprise such partnerships differ in their perceptions of the benefits and risks of fire use or nonuse. These differences inform how different stakeholders prioritize sites for burning, constrain prescribed burning, and how they rationalize these priorities and constraints. Using a survey of individuals involved in the planning and implementation of prescribed fire in the Onslow Bight region of North Carolina, we examined how the constraints and priorities for burning in the longleaf pine (Pinus palustris ecosystem differed among three stakeholder groups: prescribed burn practitioners from agencies, practitioners from private companies, and nonpractitioners. Stakeholder groups did not differ in their perceptions of constraints to burning, and development near potentially burned sites was the most important constraint identified. The top criteria used by stakeholders to decide where to burn were the time since a site was last burned, and a site's ecosystem health, with preference given to recently burned sites in good health. Differences among stakeholder groups almost always pertained to perceptions of the nonecological impacts of burning. Prescribed burning priorities of the two groups of practitioners, and particularly practitioners from private companies, tended to be most influenced by nonecological impacts, especially through deprioritization of sites that have not been burned recently or are in the wildland-urban interface (WUI. Our results highlight the difficulty of burning these sites, despite widespread laws in the southeast U.S. that limit liability of prescribed burn practitioners. To avoid ecosystem degradation on sites that are challenging to burn, particularly those in the WUI, conservation partnerships can facilitate demonstration projects involving public and private burn practitioners on those sites. In summary

  19. Lessons on black holes from the elliptic genus

    Energy Technology Data Exchange (ETDEWEB)

    Giveon, Amit [Racah Institute of Physics, The Hebrew University,Jerusalem, 91904 (Israel); Itzhaki, Nissan [Physics Department, Tel-Aviv University,Ramat-Aviv, 69978 (Israel); Troost, Jan [Laboratoire de Physique Théorique, Unité Mixte du CNRS et de l’École Normale Supérieure associée à l’Université Pierre et Marie Curie 6, École Normale Supérieure, Rue Lhomond Paris (France)

    2014-04-28

    We further study the elliptic genus of the cigar SL(2,ℝ){sub k}/U(1) coset superconformal field theory. We find that, even in the small curvature, infinite level limit, there are holomorphic and non-holomorphic parts that are due to the discrete states and a mismatch in the spectral densities of the continuum, respectively. The mismatch in the continuum is universal, in the sense that it is fully determined by the asymptotic cylindrical topology of the cigar’s throat. Since modularity of the elliptic genus requires both the holomorphic and non-holomorphic parts, the holomorphic term is universal as well. The contribution of the discrete states is thus present even for perturbative strings propagating in the background of large Schwarzschild black holes. We argue that the discrete states live at a stringy distance from the tip of the cigar both from the conformal field theory wave-function analysis and from a holonomy space perspective. Thus, the way string theory takes care of its self-consistency seems to have important consequences for the physics near horizons, even for parametrically large black holes.

  20. Epidemiology of burns

    NARCIS (Netherlands)

    Dokter, Jan

    2016-01-01

    The aim of this thesis is to understand the epidemiology, treatment and outcomes of specialized burn care in The Netherlands. This thesis is mainly based on historical data of the burn centre in Rotterdam from 1986, combined with historical data from the burn centres in Groningen and Beverwijk from

  1. Quantum corrections to Bekenstein–Hawking black hole entropy and gravity partition functions

    International Nuclear Information System (INIS)

    Bytsenko, A.A.; Tureanu, A.

    2013-01-01

    Algebraic aspects of the computation of partition functions for quantum gravity and black holes in AdS 3 are discussed. We compute the sub-leading quantum corrections to the Bekenstein–Hawking entropy. It is shown that the quantum corrections to the classical result can be included systematically by making use of the comparison with conformal field theory partition functions, via the AdS 3 /CFT 2 correspondence. This leads to a better understanding of the role of modular and spectral functions, from the point of view of the representation theory of infinite-dimensional Lie algebras. Besides, the sum of known quantum contributions to the partition function can be presented in a closed form, involving the Patterson–Selberg spectral function. These contributions can be reproduced in a holomorphically factorized theory whose partition functions are associated with the formal characters of the Virasoro modules. We propose a spectral function formulation for quantum corrections to the elliptic genus from supergravity states

  2. Comparisons of retinal nerve fiber layer thickness changes after macular hole surgery

    Directory of Open Access Journals (Sweden)

    Nelson Chamma Capelanes

    Full Text Available ABSTRACT Purpose: To compare postoperative changes in retinal nerve fiber layer thickness in patients with macular holes treated with vitrectomy with Brilliant Blue-assisted internal limiting membrane peeling. Methods: Twenty-two eyes of 20 patients with macular holes were studied. Each eye was selected to undergo Brilliant Blue-assisted internal limiting membrane peeling. The circumferential retinal nerve fiber layer thickness was determined using spectral domain optical coherence tomography preoperatively and 2 months postoperatively. Mean overall and sectoral retinal nerve fiber layer thicknesses were obtained for each patient. Results: There was no statistically significant difference (p≥0.05 between the pre- and post-treatment measurements in relation to each CFN variable, i.e., on average, pre-treatment measures were the same as post-treatment measures. Furthermore, despite the differences between the pre- and post-treatment measures always being positive (pre-post >0, they are not statistically significant. Conclusions: This study showed no significant decrease in retinal nerve fiber layer thickness measurements after macular holes surgery, regardless of age or sex.

  3. Burns and military clothing.

    Science.gov (United States)

    McLean, A D

    2001-02-01

    Burn injury is a ubiquitous threat in the military environment. The risks during combat are well recognised, but the handling of fuel, oil, munitions and other hot or flammable materials during peacetime deployment and training also imposes an inherent risk of accidental burn injury. Over the last hundred years, the burn threat in combat has ranged from nuclear weapons to small shoulder-launched missiles. Materials such as napalm and white phosphorus plainly present a risk of burn, but the threat extends to encompass personnel in vehicles attacked by anti-armour weapons, large missiles, fuel-air explosives and detonations/conflagrations on weapons platforms such as ships. Large numbers of burn casualties were caused at Pearl Harbor, in Hiroshima and Nagasaki, Vietnam, during the Arab/Israeli Wars and in the Falkland Islands conflict. The threat from burns is unlikely to diminish, indeed new developments in weapons seek to exploit the vulnerability of the serviceman and servicewoman to burns. Clothing can be a barrier to some types of burn--both inherently in the properties of the material, but also by trapping air between clothing layers. Conversely, ignition of the clothing may exacerbate a burn. There is hearsay that burnt clothing products within a wound may complicate the clinical management, or that materials that melt (thermoplastic materials) should not be worn if there is a burn threat. This paper explores the incidence of burn injury, the mechanisms of heat transfer to bare skin and skin covered by materials, and the published evidence for the complication of wound management by materials. Even light-weight combat clothing can offer significant protection to skin from short duration flash burns; the most vulnerable areas are the parts of the body not covered--face and hands. Multilayered combat clothing can offer significant protection for short periods from engulfment by flames; lightweight tropical wear with few layers offers little protection. Under

  4. Ceruloplasmin and Hypoferremia: Studies in Burn and Non-Burn Trauma Patients

    Science.gov (United States)

    2015-03-06

    ceruloplasmin; ferroxidase; iron status; oxidant stress; burn; trauma 1. Introduction Iron is an essential element for life that facilitates...899–906. 45. Shakespeare , P.G. Studies on the serum levels of iron, copper and zinc and the urinary excretion of zinc after burn injury. Burns Incl

  5. A SYSTEMATIC SEARCH FOR MASSIVE BLACK HOLE BINARIES IN THE SLOAN DIGITAL SKY SURVEY SPECTROSCOPIC SAMPLE

    International Nuclear Information System (INIS)

    Tsalmantza, P.; Decarli, R.; Hogg, David W.; Dotti, M.

    2011-01-01

    We present the results of a systematic search for massive black hole binaries in the Sloan Digital Sky Survey (SDSS) spectroscopic database. We focus on bound binaries, under the assumption that one of the black holes is active. In this framework, the broad lines associated with the accreting black hole are expected to show systematic velocity shifts with respect to the narrow lines, which trace the rest frame of the galaxy. For a sample of 54,586 quasars and 3929 galaxies at redshifts 0.1 < z < 1.5, we brute-force model each spectrum as a mixture of two quasars at two different redshifts. The spectral model is a data-driven dimensionality reduction of the SDSS quasar spectra based on a matrix factorization. We identified 32 objects with peculiar spectra. Nine of them can be interpreted as black hole binaries. This doubles the number of known black hole binary candidates. We also report on the discovery of a new class of extreme double-peaked emitters with exceptionally broad and faint Balmer lines. For all the interesting sources, we present detailed analysis of the spectra and discuss possible interpretations.

  6. Photoreceptor Outer Segment on Internal Limiting Membrane after Macular Hole Surgery: Implications for Pathogenesis.

    Science.gov (United States)

    Grinton, Michael E; Sandinha, Maria T; Steel, David H W

    2015-01-01

    This report presents a case, which highlights key principles in the pathophysiology of macular holes. It has been hypothesized that anteroposterior (AP) and tangential vitreous traction on the fovea are the primary underlying factors causing macular holes [Nischal and Pearson; in Kanski and Bowling: Clinical Ophthalmology: A Systemic Approach, 2011, pp 629-631]. Spectral domain optical coherence tomography (OCT) has subsequently corroborated this theory in part but shown that AP vitreofoveal traction is the more common scenario [Steel and Lotery: Eye 2013;27:1-21]. This study was conducted as a single case report. A 63-year old female presented to her optician with blurred and distorted vision in her left eye. OCT showed a macular hole with a minimum linear diameter of 370 µm, with persistent broad vitreofoveal attachment on both sides of the hole edges. The patient underwent combined left phacoemulsification and pars plana vitrectomy, internal limiting membrane (ILM) peel and gas injection. The ILM was examined by electron microscopy and showed the presence of a cone outer segment on the retinal side. Post-operative OCT at 11 weeks showed a closed hole with recovery of the foveal contour and good vision. Our case shows the presence of a photoreceptor outer segment on the retinal side of the ILM and reinforces the importance of tangential traction in the development of some macula holes. The case highlights the theory of transmission of inner retinal forces to the photoreceptors via Müller cells and how a full thickness macular hole defect can occur in the absence of AP vitreomacular traction.

  7. Brown carbon in fresh and aged biomass burning emissions

    Science.gov (United States)

    Saleh, R.; Robinson, E.; Tkacik, D. S.; Ahern, A.; Liu, S.; Aiken, A. C.; Sullivan, R. C.; Presto, A. A.; Dubey, M.; Donahue, N. M.; Robinson, A. L.

    2013-12-01

    wavelength (lambda) of 550 nm increases linearly with the BC-to-OA ratio, while the spectral-dependence, w, where k¬OA = kOA,550nm*(550/lambda)w, is inversely proportional to the BC-to-OA ratio. These correlations were determined by examining emissions from small scale laboratory burns of six globally relevant fuels (black spruce, ponderosa pine, hay, rice straw, saw grass, and wire grass), assuming that their behavior can be extrapolated to other biomass fuels. Experiments were conducted during the Fire Laboratory at Missoula Campaign (FLAME 4). The BC-to-OA ratios in the experiments were between 0.01 and 0.2. Aging of the emissions (photo-oxidation or dark ozonolysis) was performed in a smog chamber. To determine the dependence of absorptivity on volatility, the SVOCs were stripped from the condensed phase by heating the emissions to 250 C inside a thermodenuder. This allowed for constraining the optical properties of the low-volatility residue. kOA values were retrieved by performing optical closure, which combines Mie theory calculations with measurements of light absorption, and total and BC size distributions.

  8. Preliminary analysis of geophysical logs from drill hole UE-25p No. 1, Yucca Mountain, Nye County, Nevada

    International Nuclear Information System (INIS)

    Muller, D.C.; Kibler, J.E.

    1984-01-01

    Geophysical logs from drill hole UE-25p No. 1 correlate well with logs through the same geologic units from other drill holes at Yucca Mountain, Nevada. The in-situ physical properties of the rocks as determined from well logs are consistent with laboratory-measured physical properties of core from other drill holes. The density, neutron and caliper logs are very spiky through most of the Topopah Spring Member. This spikiness occurs on the same logs in cored holes where the Topopah Spring Member is highly fractured and lithophysal. The uranium channel of the spectral gamma-ray log through the Topopah Spring Member correlates with uranium logs from cored holes where most of the fractures have not been healed or filled with materials that concentrate uranium. Therefore, fracture porosity and permeability of the Topopah Spring Member are expected to be high and consistent with fracture analysis from other drill holes on Yucca Mountain, and hydrologic tests from well J-13. The Paleozoic dolomites which underlie the Tertiary tuffs are intensely brecciated, and the uranium count rate is much higher than normal for dolomites because uranium has been concentrated in the recementing material. 19 references, 1 figure, 2 tables

  9. Low-mass black holes as the remnants of primordial black hole formation.

    Science.gov (United States)

    Greene, Jenny E

    2012-01-01

    Bridging the gap between the approximately ten solar mass 'stellar mass' black holes and the 'supermassive' black holes of millions to billions of solar masses are the elusive 'intermediate-mass' black holes. Their discovery is key to understanding whether supermassive black holes can grow from stellar-mass black holes or whether a more exotic process accelerated their growth soon after the Big Bang. Currently, tentative evidence suggests that the progenitors of supermassive black holes were formed as ∼10(4)-10(5) M(⊙) black holes via the direct collapse of gas. Ongoing searches for intermediate-mass black holes at galaxy centres will help shed light on this formation mechanism.

  10. Burn Wise

    Science.gov (United States)

    Burn Wise is a partnership program of the U.S. Environmental Protection Agency that emphasizes the importance of burning the right wood, the right way, in the right appliance to protect your home, health, and the air we breathe.

  11. Inferring brown carbon content from UV aerosol absorption measurements during biomass burning season

    Science.gov (United States)

    Mok, J.; Krotkov, N. A.; Arola, A. T.; Torres, O.; Jethva, H. T.; Andrade, M.; Labow, G. J.; Eck, T. F.; Li, Z.; Dickerson, R. R.; Stenchikov, G. L.; Osipov, S.

    2015-12-01

    Measuring spectral dependence of light absorption by colored organic or "brown" carbon (BrC) is important, because of its effects on photolysis rates of ozone and surface ultraviolet (UV) radiation. Enhanced UV spectral absorption by BrC can in turn be exploited for simultaneous retrievals of BrC and black carbon (BC) column amounts in field campaigns. We present an innovative ground-based retrieval of BC and BrC volume fractions and their mass absorption efficiencies during the biomass burning season in Santa Cruz, Bolivia in September-October 2007. Our method combines retrieval of BC volume fraction using AERONET inversion in visible wavelengths with the inversion of total BC+BrC absorption (i.e., column effective imaginary refractive index, kmeas) using Diffuse/Direct irradiance measurements in UV wavelengths. First, we retrieve BrC volume fraction by fitting kmeas at 368nm using Maxwell-Garnett (MG) mixing rules assuming: (1) flat spectral dependence of kBC, (2) known value of kBrC at 368nm from laboratory absorption measurements or smoke chamber experiments, and (3) known BC volume fraction from AERONET inversion. Next, we derive kBrC in short UVB wavelengths by fitting kmeas at 305nm, 311nm, 317nm, 325nm, and 332nm using MG mixing rules and fixed volume fractions of BC and BrC. Our retrievals show larger than expected spectral dependence of kBrC in UVB wavelengths, implying reduced surface UVB irradiance and inhibited photolysis rates of surface ozone destruction. We use a one-dimensional chemical box model to show that the observed strong wavelength dependence of BrC absorption leads to inhibited photolysis of ozone to O(1D), a loss mechanism, while having little impact or even accelerating photolysis of NO2, an ozone production mechanism. Although BC only absorption in biomass burning aerosols is important for climate radiative forcing in the visible wavelengths, additional absorption by BrC is important because of its impact on surface UVB radiation

  12. Effects of radiation, burn and combined radiation-burn injury on hemodynamics

    International Nuclear Information System (INIS)

    Ye Benlan; Cheng Tianming; Xiao Jiasi

    1996-01-01

    Changes in hemodynamics after radiation, burn and combined radiation burn injury within eight hours post injury were studied. The results indicate: (1) Shock of rats in the combined injury group is more severe than that in the burn group. One of the reasons is that the blood volume in the combined injury group is less than that in the burn group. Radiation injury plays an important role in this effect, which enhances the increase in vascular permeability and causes the loss of plasma. (2) Decrease in cardiac output and stroke work and increase in vascular resistance in the combined radiation burn group are more drastic than those in the burn group, which may cause and enhance shock. Replenishing fluid is useful for recovery of hemodynamics. (3) Rb uptake is increased in the radiation group which indicates that compensated increase of myocardial nutritional blood flow may take place before the changes of hemodynamics and shock. Changes of Rb uptake in the combined injury group is different from that in the radiation groups and in the burn group. The results also suggest that changes of ion channel activities may occur to a different extent after injury. (4) Verapamil is helpful to the recovery of hemodynamics post injury. It is better to combine verapamil with replenishing fluid

  13. CLINICAL STUDY OF ELECTRICAL BURNS AMONG ALL BURNS CASES- 3 YEARS’ EXPERIENCE

    Directory of Open Access Journals (Sweden)

    Nagabathula Durga Prasad

    2017-08-01

    Full Text Available BACKGROUND With the advances in technology, electrical injuries are becoming more common and are the leading cause of work-related traumatic death. One third of all electrical traumas and most high-voltage injuries are job related and more than 50% of these injuries result from power line contact. The management of the major burn injury represents a significant challenge to every member of the burns team. Most of electrical burns present with gangrene of toes and limbs with eschar over body parts. Their presentation is mostly due to contact with high-voltage electricity at their work places. MATERIALS AND METHODS A retrospective study was made to study the clinico-social profile of patients suffering electric burns admitted into Department of General Surgery. RESULTS 92 cases were evaluated and studied. Majority of patients developed gangrene of limbs and toes. Amputations and skin grafting was done. Most patients who suffered electric burns were males of age group 21 to 40 years. All cases are accidental and mostly occurred at work places. Most electric burns are high-voltage based and caused deep burns. Major complications like acute renal failure and septicaemia were encountered. Most of them suffered 16 to 30% burns. Most commonly isolated organism from wounds is pseudomonas. Most of them suffered a hospital stay of 1 to 2 months. CONCLUSION Electric burns are a burden to the society. Prevention is the best way to deal with them. Electricity-based employees have to be trained properly regarding safety measures to be taken. General education of public regarding safety measures can prevent electrical burn injuries.

  14. Hole dephasing caused by hole-hole interaction in a multilayered black phosphorus.

    Science.gov (United States)

    Li, Lijun; Khan, Muhammad Atif; Lee, Yoontae; Lee, Inyeal; Yun, Sun Jin; Youn, Doo-Hyeb; Kim, Gil-Ho

    2017-11-01

    We study the magnetotransport of holes in a multilayered black phosphorus in a temperature range of 1.9 to 21.5 K. We observed a negative magnetoresistance at magnetic fields up to 1.5 T. This negative magetoresistance was analyzed by weak localization theory in diffusive regime. At the lowest temperature and the highest carrier density we found a phase coherence length of 48 nm. The linear temperature dependence of the dephasing rate shows that the hole-hole scattering processes with small energy transfer are the dominant contribution in breaking the carrier phase coherence.

  15. Outcomes of burns in the elderly: revised estimates from the Birmingham Burn Centre.

    Science.gov (United States)

    Wearn, Christopher; Hardwicke, Joseph; Kitsios, Andreas; Siddons, Victoria; Nightingale, Peter; Moiemen, Naiem

    2015-09-01

    Outcomes after burn have continued to improve over the last 70 years in all age groups including the elderly. However, concerns have been raised that survival gains have not been to the same magnitude in elderly patients compared to younger age groups. The aims of this study were to analyze the recent outcomes of elderly burn injured patients admitted to the Birmingham Burn Centre, compare data with a historical cohort and published data from other burn centres worldwide. A retrospective review was conducted of all patients ≥65 years of age, admitted to our centre with cutaneous burns, between 2004 and 2012. Data was compared to a previously published historical cohort (1999-2003). 228 patients were included. The observed mortality for the study group was 14.9%. The median age of the study group was 79 years, the male to female ratio was 1:1 and median Total Body Surface Area (TBSA) burned was 5%. The incidence of inhalation injury was 13%. Median length of stay per TBSA burned for survivors was 2.4 days/% TBSA. Mortality has improved in all burn size groups, but differences were highly statistically significant in the medium burn size group (10-20% TBSA, p≤0.001). Burn outcomes in the elderly have improved over the last decade. This reduction has been impacted by a reduction in overall injury severity but is also likely due to general improvements in burn care, improved infrastructure, implementation of clinical guidelines and increased multi-disciplinary support, including Geriatric physicians. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

  16. The Hunt for Low-Mass Black Holes in the JWST Era

    Science.gov (United States)

    Cann, Jenna; Satyapal, Shobita; Abel, Nicholas; Ricci, Claudio; Gliozzi, Mario; Blecha, Laura; Secrest, Nathan

    2018-01-01

    Most, if not all, massive galaxies have a central supermassive black hole (SMBH) millions to billions of times the mass of the Sun. While the properties of SMBHs and their host galaxies have been well-studied in massive galaxies, very few SMBHs have been found in galaxies with low masses and those with small bulges. This is a significant deficiency, because the study of this population allows us to gain an understanding of merger-free pathways to black hole growth, and to gain insight into the origin and growth of SMBH ‘seeds’, thought to have formed at high redshift. Most studies aimed at finding SMBHs have been conducted using optical spectroscopic studies, where active SMBHs (active galactic nuclei or AGNs) display distinctive optical emission lines indicative of accreting SMBHs. However, in low mass (dwarf) galaxies, the SMBHs will likely be less massive, and can be energetically weak and possibly deeply embedded in their host galaxies. As a result, the optical emission lines may be dominated by star formation regions, severely limiting the diagnostic power of optical surveys in finding and characterizing the properties of the AGN in dwarf galaxies. In such galaxies, infrared coronal lines provide a robust method of finding AGNs. Furthermore, as the black hole mass decreases, the Schwarzschild radius of the black hole decreases, and in response, the temperature of the surrounding accretion disk increases. The shape of the ionizing radiation spectral energy distribution therefore changes with black hole mass, which will affect the emission line spectrum from the surrounding gas. In this work, we investigate the diagnostic power of infrared coronal lines and the effect of black hole mass on the emission line spectra from AGNs, with a particular focus on the emission lines accessible by JWST.

  17. Wound management and outcome of 595 electrical burns in a major burn center.

    Science.gov (United States)

    Li, Haisheng; Tan, Jianglin; Zhou, Junyi; Yuan, Zhiqiang; Zhang, Jiaping; Peng, Yizhi; Wu, Jun; Luo, Gaoxing

    2017-06-15

    Electrical burns are important causes of trauma worldwide. This study aims to analyze the clinical characteristics, wound management, and outcome of electric burns. This retrospective study was performed at the Institute of Burn Research of the Third Military Medical University during 2013-2015. Data including the demographics, injury patterns, wound treatment, and outcomes were collected and analyzed. A total of 595 electrical burn patients (93.8% males) were included. The average age was 37.3 ± 14.6 y, and most patients (73.5%) were aged 19∼50 years. Most patients (67.2%) were injured in work-related circumstances. The mean total body surface area was 8.8 ± 11.8% and most wounds (63.5%) were full-thickness burns. Operation times of high-voltage burns and current burns were higher than those of low-voltage burns and arc burns, respectively. Of the 375 operated patients, 83.2% (n = 312) underwent skin autografting and 49.3% (n = 185) required skin flap coverage. Common types of skin flaps were adjacent (50.3%), random (42.2%), and pedicle (35.7%). Amputation was performed in 107 cases (18.0%) and concentrated on the hands (43.9%) and upper limbs (39.3%). The mean length of stay was 42.9 ± 46.3 d and only one death occurred (0.2%). Current burns and higher numbers of operations were major risk factors for amputation and length of stay, respectively. Electrical burns mainly affected adult males with occupational exposures in China. Skin autografts and various skin flaps were commonly used for electric burn wound management. More standardized and effective strategies of treatment and prevention are still needed to decrease amputation rates. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. MODIS 250m burned area mapping based on an algorithm using change point detection and Markov random fields.

    Science.gov (United States)

    Mota, Bernardo; Pereira, Jose; Campagnolo, Manuel; Killick, Rebeca

    2013-04-01

    Area burned in tropical savannas of Brazil was mapped using MODIS-AQUA daily 250m resolution imagery by adapting one of the European Space Agency fire_CCI project burned area algorithms, based on change point detection and Markov random fields. The study area covers 1,44 Mkm2 and was performed with data from 2005. The daily 1000 m image quality layer was used for cloud and cloud shadow screening. The algorithm addresses each pixel as a time series and detects changes in the statistical properties of NIR reflectance values, to identify potential burning dates. The first step of the algorithm is robust filtering, to exclude outlier observations, followed by application of the Pruned Exact Linear Time (PELT) change point detection technique. Near-infrared (NIR) spectral reflectance changes between time segments, and post change NIR reflectance values are combined into a fire likelihood score. Change points corresponding to an increase in reflectance are dismissed as potential burn events, as are those occurring outside of a pre-defined fire season. In the last step of the algorithm, monthly burned area probability maps and detection date maps are converted to dichotomous (burned-unburned maps) using Markov random fields, which take into account both spatial and temporal relations in the potential burned area maps. A preliminary assessment of our results is performed by comparison with data from the MODIS 1km active fires and the 500m burned area products, taking into account differences in spatial resolution between the two sensors.

  19. Burning mouth syndrome

    Directory of Open Access Journals (Sweden)

    K A Kamala

    2016-01-01

    Full Text Available Burning mouth syndrome (BMS is multifactorial in origin which is typically characterized by burning and painful sensation in an oral cavity demonstrating clinically normal mucosa. Although the cause of BMS is not known, a complex association of biological and psychological factors has been identified, suggesting the existence of a multifactorial etiology. As the symptom of oral burning is seen in various pathological conditions, it is essential for a clinician to be aware of how to differentiate between symptom of oral burning and BMS. An interdisciplinary and systematic approach is required for better patient management. The purpose of this study was to provide the practitioner with an understanding of the local, systemic, and psychosocial factors which may be responsible for oral burning associated with BMS, and review of treatment modalities, therefore providing a foundation for diagnosis and treatment of BMS.

  20. Assessment of burn-specific health-related quality of life and patient scar status following burn.

    Science.gov (United States)

    Oh, Hyunjin; Boo, Sunjoo

    2017-11-01

    This study assessed patient-perceived levels of scar assessment and burn-specific quality of life (QOL) in Korean burn patients admitted to burn care centers and identified differences in scar assessment and QOL based on various patient characteristics. A cross-sectional descriptive study using anonymous paper-based survey methods was conducted with 100 burn patients from three burn centers specializing in burn care in South Korea. Mean subject age was 44.5 years old, and 69% of the subjects were men. The overall mean QOL was 2.91 out of 5. QOL was lowest for the work subdomain (2.25±1.45) followed by the treatment regimen subdomain (2.32±1.16). The subjects' mean total scar assessment score was 35.51 out of 60, and subjects were most unsatisfied with scar color. Subjects with low income, flame-source burns, severe burns, visible scars, and scars on face or hand reported significantly lower QOL. Subjects with severe burn degree and burn range perceived their burn scar condition to be worse than that of others. The results show that burn subjects experience the most difficulties with their work and the treatment regimen. Subjects with severe burn and visible scarring have a reduced QOL and a poor scar status. Scar management intervention may improve QOL of burn patients especially those with severe burn and visible scars. Further studies are warranted to evaluate the relationship between scar assessment and QOL. Copyright © 2017 Elsevier Ltd and ISBI. All rights reserved.

  1. Epidemiology, etiology and outcomes of burn patients in a Referral Burn Hospital, Tehran

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Soltan Dallal

    2016-08-01

    Full Text Available Background: Burns and its complications are regarded as a major problem in the society. Skin injuries resulted from ultraviolet radiation, radioactivity, electricity or chemicals as well as respiratory damage from smoke inhalation are considered burns. This study aimed to determine the epidemiology and outcome of burn patients admitted to Motahari Hospital, Tehran, Iran. Methods: Two hundred patients with second-degree burns admitted to Motahari Referral Center of Burn in Tehran, Iran. They were studied during a period of 12 months from May 2012 to May 2013. During the first week of treatment swabs were collected from the burn wounds after cleaning the site with sterile normal saline. Samples were inoculated in blood agar and McConkey agar, then incubation at 37 C for 48 hours. Identification was carried out according to standard conventional biochemical tests. Treatment continued up to epithelial formation and wound healing. Results of microbial culture for each patient was recorded. Healing time of the burn wounds in patients was recorded in log books. Chi-square test and SPSS Software v.19 (IBM, NY, USA were used for data analysis. Results: Our findings indicate that the most causes of burns are hot liquids in 57% of cases and flammable liquid in 21% of cases. The most cases of burns were found to be in the range of 21 to 30 percent with 17.5% and 7% in male and female respectively. Gram-negative bacteria were dominated in 85.7% and among them pseudomonas spp. with 37.5% were the most common cause of infected burns, followed by Enterobacter, Escherichia coli, Staphylococcus aureus, Acinetobacter and Klebsiella spp. Conclusion: The results of this study showed that the most cause of burns in both sex is hot liquid. Men were more expose to burn than women and this might be due to the fact that men are involved in more dangerous jobs than female. Pseudomonas aeruginosa was the most common organism encountered in burn infection.

  2. Bifurcation from stable holes to replicating holes in vibrated dense suspensions.

    Science.gov (United States)

    Ebata, H; Sano, M

    2013-11-01

    In vertically vibrated starch suspensions, we observe bifurcations from stable holes to replicating holes. Above a certain acceleration, finite-amplitude deformations of the vibrated surface continue to grow until void penetrates fluid layers, and a hole forms. We studied experimentally and theoretically the parameter dependence of the holes and their stabilities. In suspensions of small dispersed particles, the circular shapes of the holes are stable. However, we find that larger particles or lower surface tension of water destabilize the circular shapes; this indicates the importance of capillary forces acting on the dispersed particles. Around the critical acceleration for bifurcation, holes show intermittent large deformations as a precursor to hole replication. We applied a phenomenological model for deformable domains, which is used in reaction-diffusion systems. The model can explain the basic dynamics of the holes, such as intermittent behavior, probability distribution functions of deformation, and time intervals of replication. Results from the phenomenological model match the linear growth rate below criticality that was estimated from experimental data.

  3. Quantifying soil burn severity for hydrologic modeling to assess post-fire effects on sediment delivery

    Science.gov (United States)

    Dobre, Mariana; Brooks, Erin; Lew, Roger; Kolden, Crystal; Quinn, Dylan; Elliot, William; Robichaud, Pete

    2017-04-01

    . Alternative spectral indices and modeled output approaches may prove better predictors of soil burn severity and hydrologic effects, but these have not yet been assessed in a model framework. In this project we compare field-verified soil burn severity maps to satellite-derived and modeled burn severity maps. We quantify the extent to which there are systematic differences in these mapping products. We then use the Water Erosion Prediction Project (WEPP) hydrologic soil erosion model to assess sediment delivery from these fires using the predicted and observed soil burn severity maps. Finally, we discuss differences in observed and predicted soil burn severity maps and application to watersheds in the Pacific Northwest to estimate post-fire sediment delivery.

  4. The epidemology of burn injuries of children and the importance of modern burn centre

    Directory of Open Access Journals (Sweden)

    Janez Mohar

    2007-01-01

    Full Text Available Background: Burns represent the major percentage of injuries to children. Their incidence level, injury mechanisms and treatment often differ from the burn injuries of adults.Methods: From the medical records of the Department for Plastic and Reconstructive Surgery of the Ljubljana Medical Centre we gathered, analyzed and compared the burn injuries of children up to the age of 15 who were admitted to hospital in the year 2003 to those who were treated as outpatients. Moreover, we compared the burn injuries of hospitalized children at the same department in the years 2003, 1993 and 1983 respectively. We compared their gender, age, the total body surface area of burns, the depth of burns, frequency of the mechanisms of injury, the affected parts of the body and the length and mode of treatment. Finally, we compared our results with the results of similar studies from other burn centres.Results: The number of children treated for burns at the department has declined. In all the years studied, the injured children were younger than 5 and the majority of them were boys. The number of children admitted with substantial total body surface areas of burns was also declining. However, there was an increase in the number of children admitted with burns less than 10 % of their total body surface area. The number of burns treated by surgery slightly increased over the years studied. There was a similar sex and age distribution among the hospitalized children and those treated as outpatients.Conclusions: The number of children hospitalized with burns is in decline. In the years 1983, 1993 and 2003, there was no significant difference in the percentage of children who were treated surgically and those who were treated conservatively (P = 0.247. The Burn Centre at the Department for Plastic and Reconstructive Surgery of the Ljubljana Medical Centre which together with the Burn Department of the Maribor General Hospital covers the population of two million

  5. Mars Reconnaissance Orbiter and Opportunity observations of the Burns formation: crater hopping at Meridiani Planum

    Science.gov (United States)

    R.E. Arvidson,; Bell, J.F.; Catalano, J.G.; Clark, B. C.; Fox, V.K.; Gellert, Ralf; Grotzinger, J.P.; Guinness, E.A.; Herkenhoff, Kenneth E.; Knoll, A.H.; Lapotre, M.G.A.; McLennan, S.M.; Ming, D. W.; Morris, R.V.; Murchie, S.L.; Powell, K. E.; Smith, M.D.; Squyres, S. W.; Wolff, M.J.; J.J. Wray,

    2015-01-01

    Compact Reconnaissance Imaging Spectrometer for Mars hyperspectral (1.0–2.65 µm) along-track oversampled observations covering Victoria, Santa Maria, Endeavour, and Ada craters were processed to 6 m/pixel and used in combination with Opportunity observations to detect and map hydrated Mg and Ca sulfate minerals in the Burns formation. The strongest spectral absorption features were found to be associated with outcrops that are relatively young and fresh (Ada) or preferentially scoured of dust, soil, and coatings by prevailing winds. At Victoria and Santa Maria, the scoured areas are on the southeastern rims and walls, opposite to the sides where wind-blown sands extend out of the craters. At Endeavour, the deepest absorptions are in Botany Bay, a subdued and buried rim segment that exhibits high thermal inertias, extensive outcrops, and is interpreted to be a region of enhanced wind scour extending up and out of the crater. Ada, Victoria, and Santa Maria outcrops expose the upper portion of the preserved Burns formation and show spectral evidence for the presence of kieserite. In contrast, gypsum is pervasive spectrally in the Botany Bay exposures. Gypsum, a relatively insoluble evaporative mineral, is interpreted to have formed close to the contact with the Noachian crust as rising groundwaters brought brines close to and onto the surface, either as a direct precipitate or during later diagenesis. The presence of kieserite at the top of the section is hypothesized to reflect precipitation from evaporatively concentrated brines or dehydration of polyhydrated sulfates

  6. Symposium on Unconventional Photoactive Solids (6th) Held in Leuven on August 15 - 19, 1993. Abstracts

    Science.gov (United States)

    1993-08-19

    analysis of the experimental data on radioluminescence spectra, light yield and fast component pulse shape for organic molecular crystals, plastic and...delayed geminate recombination fluorescence is detected above a threshold energy caracteristic of a new particular mecanism. The decay law of this...in press 157 SPECTRAL HOLE BURNING IN DYE DOPED PLASTIC FIBER H. Suzuiki.2, E. Higurashi1, A. Monnakal, T. Shimadal, K. SukegawaI and D. Haarer2 I NIT

  7. Assessment of Burned Area and Atmospheric Gases from Multi- temporal MODIS Images (2000- 2017) in Nainital District, Uttarakhand

    Science.gov (United States)

    Aggarwal, R.; K V, S. B.; Dhakate, P. M.

    2017-12-01

    Recent times have observed a significant rate of deforestation and forest degradation. One of the major causes of forest degradation is forest fires. Forest fires though have shaped the current forest ecosystem but also have continued to degrade the system by causing loss of flora and fauna. In addition to that, forest fire leads to emission of carbon and other trace gases which contributes to global warming. The hill states in India, particularly Uttarakhand witnesses annual forest fires; which are primarily anthropogenic caused, occurring from March to June. Nainital one of the thirteen districts in Uttarakhand, has been selected as the study site. The region has diverse endemic species of vegetation, ranging from Alpine in North to moist deciduous in South. The increasing forest fire incidents in the region and limited studies on the subject, calls for landscape assessment of the complex Human Environment System (HES). It is in this context, that a greater need for monitoring forest fire incidents has been felt. Remote Sensing and GIS which are robust tool, provides continuous information of an area at various spatial and temporal resolutions. The goal of this study is to map burned area, burned severity and estimate atmospheric gas emissions in forested areas of Nainital by utilizing cloud free MODIS images from 2000- 2017. Multiple spectral indices were generated from pre and post burn dataset of MODIS to conclude the most sensitive band combination. Inter- comparison of results obtained from different spectral indices and the global MODIS MCD45A1 was carried out using linear regression analysis. Additionally, burned area estimation from satellite was compared to figures reported by forest department. There were considerable differences amongst the two which could be primarily due to differences in spatial resolution, and timings of forest fire occurrence and image acquisition. Further, estimation of various atmospheric gases was carried out based on the IPCC

  8. Pediatric burns: Kids' Inpatient Database vs the National Burn Repository.

    Science.gov (United States)

    Soleimani, Tahereh; Evans, Tyler A; Sood, Rajiv; Hartman, Brett C; Hadad, Ivan; Tholpady, Sunil S

    2016-04-01

    Burn injuries are one of the leading causes of morbidity and mortality in young children. The Kids' Inpatient Database (KID) and National Burn Repository (NBR) are two large national databases that can be used to evaluate outcomes and help quality improvement in burn care. Differences in the design of the KID and NBR could lead to differing results affecting resultant conclusions and quality improvement programs. This study was designed to validate the use of KID for burn epidemiologic studies, as an adjunct to the NBR. Using the KID (2003, 2006, and 2009), a total of 17,300 nonelective burn patients younger than 20 y old were identified. Data from 13,828 similar patients were collected from the NBR. Outcome variables were compared between the two databases. Comparisons revealed similar patient distribution by gender, race, and burn size. Inhalation injury was more common among the NBR patients and was associated with increased mortality. The rates of respiratory failure, wound infection, cellulitis, sepsis, and urinary tract infection were higher in the KID. Multiple regression analysis adjusting for potential confounders demonstrated similar mortality rate but significantly longer length of stay for patients in the NBR. Despite differences in the design and sampling of the KID and NBR, the overall demographic and mortality results are similar. The differences in complication rate and length of stay should be explored by further studies to clarify underlying causes. Investigations into these differences should also better inform strategies to improve burn prevention and treatment. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. LNG pool fire spectral data and calculation of emissive power

    International Nuclear Information System (INIS)

    Raj, Phani K.

    2007-01-01

    Spectral description of thermal emission from fires provides a fundamental basis on which the fire thermal radiation hazard assessment models can be developed. Several field experiments were conducted during the 1970s and 1980s to measure the thermal radiation field surrounding LNG fires. Most of these tests involved the measurement of fire thermal radiation to objects outside the fire envelope using either narrow-angle or wide-angle radiometers. Extrapolating the wide-angle radiometer data without understanding the nature of fire emission is prone to errors. Spectral emissions from LNG fires have been recorded in four test series conducted with LNG fires on different substrates and of different diameters. These include the AGA test series of LNG fires on land of diameters 1.8 and 6 m, 35 m diameter fire on an insulated concrete dike in the Montoir tests conducted by Gaz de France, a 1976 test with 13 m diameter and the 1980 tests with 10 m diameter LNG fire on water carried out at China Lake, CA. The spectral data from the Montoir test series have not been published in technical journals; only recently has some data from this series have become available. This paper presents the details of the LNG fire spectral data from, primarily, the China Lake test series, their analysis and results. Available data from other test series are also discussed. China Lake data indicate that the thermal radiation emission from 13 m diameter LNG fire is made up of band emissions of about 50% of energy by water vapor (band emission), about 25% by carbon dioxide and the remainder constituting the continuum emission by luminous soot. The emissions from the H 2 O and CO 2 bands are completely absorbed by the intervening atmosphere in less than about 200 m from the fire, even in the relatively dry desert air. The effective soot radiation constitutes only about 23% during the burning period of methane and increases slightly when other higher hydrocarbon species (ethane, propane, etc.) are

  10. Improved Survival of Patients With Extensive Burns: Trends in Patient Characteristics and Mortality Among Burn Patients in a Tertiary Care Burn Facility, 2004-2013.

    Science.gov (United States)

    Strassle, Paula D; Williams, Felicia N; Napravnik, Sonia; van Duin, David; Weber, David J; Charles, Anthony; Cairns, Bruce A; Jones, Samuel W

    Classic determinants of burn mortality are age, burn size, and the presence of inhalation injury. Our objective was to describe temporal trends in patient and burn characteristics, inpatient mortality, and the relationship between these characteristics and inpatient mortality over time. All patients aged 18 years or older and admitted with burn injury, including inhalation injury only, between 2004 and 2013 were included. Adjusted Cox proportional hazards regression models were used to estimate the relationship between admit year and inpatient mortality. A total of 5540 patients were admitted between 2004 and 2013. Significant differences in sex, race/ethnicity, burn mechanisms, TBSA, inhalation injury, and inpatient mortality were observed across calendar years. Patients admitted between 2011 and 2013 were more likely to be women, non-Hispanic Caucasian, with smaller burn size, and less likely to have an inhalation injury, in comparison with patients admitted from 2004 to 2010. After controlling for patient demographics, burn mechanisms, and differential lengths of stay, no calendar year trends in inpatient mortality were detected. However, a significant decrease in inpatient mortality was observed among patients with extensive burns (≥75% TBSA) in more recent calendar years. This large, tertiary care referral burn center has maintained low inpatient mortality rates among burn patients over the past 10 years. While observed decreases in mortality during this time are largely due to changes in patient and burn characteristics, survival among patients with extensive burns has improved.

  11. The Burning Saints

    DEFF Research Database (Denmark)

    Xygalatas, Dimitris

    . Carrying the sacred icons of the saints, participants dance over hot coals as the saint moves them. The Burning Saints presents an analysis of these rituals and the psychology behind them. Based on long-term fieldwork, The Burning Saints traces the historical development and sociocultural context......, The Burning Saints presents a highly original analysis of how mental processes can shape social and religious behaviour....

  12. Black Holes

    OpenAIRE

    Horowitz, Gary T.; Teukolsky, Saul A.

    1998-01-01

    Black holes are among the most intriguing objects in modern physics. Their influence ranges from powering quasars and other active galactic nuclei, to providing key insights into quantum gravity. We review the observational evidence for black holes, and briefly discuss some of their properties. We also describe some recent developments involving cosmic censorship and the statistical origin of black hole entropy.

  13. Laboratory Studies of Carbon Emission from Biomass Burning for use in Remote Sensing

    Science.gov (United States)

    Wald, Andrew E.; Kaufman, Yoram J.

    1998-01-01

    Biomass burning is a significant source of many trace gases in the atmosphere. Up to 25% of the total anthropogenic carbon dioxide added to the atmosphere annually is from biomass burning. However, this gaseous emission from fires is not directly detectable from satellite. Infrared radiance from the fires is. In order to see if infrared radiance can be used as a tracer for these emitted gases, we made laboratory measurements to determine the correlation of emitted carbon dioxide, carbon monoxide and total burned biomass with emitted infrared radiance. If the measured correlations among these quantities hold in the field, then satellite-observed infrared radiance can be used to estimate gaseous emission and total burned biomass on a global, daily basis. To this end, several types of biomass fuels were burned under controlled conditions in a large-scale combustion laboratory. Simultaneous measurements of emitted spectral infrared radiance, emitted carbon dioxide, carbon monoxide, and total mass loss were made. In addition measurements of fuel moisture content and fuel elemental abundance were made. We found that for a given fire, the quantity of carbon burned can be estimated from 11 (micro)m radiance measurements only within a factor of five. This variation arises from three sources, 1) errors in our measurements, 2) the subpixel nature of the fires, and 3) inherent differences in combustion of different fuel types. Despite this large range, these measurements can still be used for large-scale satellite estimates of biomass burned. This is because of the very large possible spread of fire sizes that will be subpixel as seen by Moderate Resolution Imaging Spectroradiometer (MODIS). Due to this large spread, even relatively low-precision correlations can still be useful for large-scale estimates of emitted carbon. Furthermore, such estimates using the MODIS 3.9 (micro)m channel should be even more accurate than our estimates based on 11 (micro)m radiance.

  14. Black hole levitron

    International Nuclear Information System (INIS)

    Arsiwalla, Xerxes D.; Verlinde, Erik P.

    2010-01-01

    We study the problem of spatially stabilizing four dimensional extremal black holes in background electric/magnetic fields. Whilst looking for stationary stable solutions describing black holes placed in external fields we find that taking a continuum limit of Denef et al.'s multicenter supersymmetric black hole solutions provides a supergravity description of such backgrounds within which a black hole can be trapped within a confined volume. This construction is realized by solving for a levitating black hole over a magnetic dipole base. We comment on how such a construction is akin to a mechanical levitron.

  15. Noncommutative black holes

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-DomInguez, J C [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico); Obregon, O [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico); RamIrez, C [Facultad de Ciencias FIsico Matematicas, Universidad Autonoma de Puebla, PO Box 1364, 72000 Puebla (Mexico); Sabido, M [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico)

    2007-11-15

    We study noncommutative black holes, by using a diffeomorphism between the Schwarzschild black hole and the Kantowski-Sachs cosmological model, which is generalized to noncommutative minisuperspace. Through the use of the Feynman-Hibbs procedure we are able to study the thermodynamics of the black hole, in particular, we calculate Hawking's temperature and entropy for the 'noncommutative' Schwarzschild black hole.

  16. Covering techniques for severe burn treatment: lessons for radiological burn accidents

    International Nuclear Information System (INIS)

    Carsin, H.; Stephanazzi, J.; Lambert, F.; Curet, P.M.; Gourmelon, P.

    2002-01-01

    Covering techniques for severe burn treatment: lessons for radiological burn accidents. After a severe burn, the injured person is weakened by a risk of infection and a general inflammation. The necrotic tissues have to be removed because they are toxic for the organism. The injured person also needs to be covered by a cutaneous envelope, which has to be done by a treatment centre for burned people. The different techniques are the following: - auto grafts on limited burned areas; - cutaneous substitutes to cover temporary extended burned areas. Among them: natural substitutes like xenografts (pork skin, sheep skin,..) or allografts (human skin), - treated natural substitutes which only maintain the extracellular matrix. Artificial skins belong to this category and allow the development of high quality scars, - cell cultures in the laboratory: multiplying the individual cells and grafting them onto the patient. This technique is not common but allows one to heal severely injured patients. X-ray burns are still a problem. Their characteristics are analysed: intensive, permanent, antalgic resistant pain. They are difficult to compare with heat burns. In spite of a small number of known cases, we can give some comments and guidance on radio necrosis cures: the importance of the patients comfort, of ending the pain, of preventing infection, and nutritional balance. At the level of epidermic inflammation and phlyctena (skin blisters), the treatment may be completed by the use of growth factors. At the level of necrosis, after a temporary cover, an auto graft can be considered only if a healthy basis is guaranteed. The use of cellular cultures in order to obtain harmonious growth factors can be argued. (author)

  17. Black hole critical phenomena without black holes

    Indian Academy of Sciences (India)

    large values of Ф, black holes do form and for small values the scalar field ... on the near side of the ridge ultimately evolve to form black holes while those configu- ... The inset shows a bird's eye view looking down on the saddle point.

  18. Search for black holes

    International Nuclear Information System (INIS)

    Cherepashchuk, Anatolii M

    2003-01-01

    Methods and results of searching for stellar mass black holes in binary systems and for supermassive black holes in galactic nuclei of different types are described. As of now (June 2002), a total of 100 black hole candidates are known. All the necessary conditions Einstein's General Relativity imposes on the observational properties of black holes are satisfied for candidate objects available, thus further assuring the existence of black holes in the Universe. Prospects for obtaining sufficient criteria for reliably distinguishing candidate black holes from real black holes are discussed. (reviews of topical problems)

  19. Spectral degeneracy and escape dynamics for intermittent maps with a hole

    International Nuclear Information System (INIS)

    Froyland, Gary; Stancevic, Ognjen; Murray, Rua

    2011-01-01

    We study intermittent maps from the point of view of metastability. Small neighbourhoods of an intermittent fixed point and their complements form pairs of almost-invariant sets. Treating the small neighbourhood as a hole, we first show that the absolutely continuous conditional invariant measures (ACCIMs) converge to the ACIM as the length of the small neighbourhood shrinks to zero. We then quantify how the escape dynamics from these almost-invariant sets are connected with the second eigenfunctions of Perron–Frobenius (transfer) operators when a small perturbation is applied near the intermittent fixed point. In particular, we describe precisely the scaling of the second eigenvalue with the perturbation size, provide upper and lower bounds and demonstrate L 1 convergence of the positive part of the second eigenfunction to the ACIM as the perturbation goes to zero. This perturbation and associated eigenvalue scalings and convergence results are all compatible with Ulam's method and provide a formal explanation for the numerical behaviour of Ulam's method in this nonuniformly hyperbolic setting. The main results of the paper are illustrated with numerical computations

  20. [Combined burn trauma in the array of modern civilian and combat burns].

    Science.gov (United States)

    Ivchenko, E V; Borisov, D N; Golota, A S; Krassiĭ, A B; Rusev, I T

    2015-02-01

    The current article positions the combined burn and non-burn injuries in the general array of civilian and combat burns. For that purpose the official state statistics and scientific medical publications, domestic as well as foreign, have been analyzed. It has been shown that in peace time the combined burn/trauma injuries are infrequent. But the same type of injury becomes routine especially among the civilian population in the conditions of the modern so called "hybrid war". And the medical service should be prepared for it.

  1. Spectral evolution of active galactic nuclei: A unified description of the X-ray and gamma-ray backgrounds

    International Nuclear Information System (INIS)

    Letter, D.; Boldt, E.

    1982-01-01

    A model for spectral evolution is presented whereby active galactic nuclei (AGN) of the type observed individually have emerged from an earlier stage at zroughly-equal4 in which they are the thermal X-ray sources responsible for most of the comic X-ray background (CXB). We pursue the conjecture that these precursor objects are initially supermassive Schwarzschild black holes with accretion disks radiating near the Eddington luminosity limit. It is noted that after approx.10 8 years these central black holes are spun up to a ''canonical'' Kerr equilibriuim state (a/M = 0.998) and shown how they can lead to spectral evolution involving nonthermal emission extending to gamma-rays, at the expense of reduced thermal disk radiation. A superposition of sources in the precursor stage can thereby account for that major portion of the CXB remaining after the contributions of usual AGN are considered, while a superposition of AGN sources at z<1 can account for the gamima-ray background. Extensive X-ray measurements carried out with the HEAO 1 and HEAO 2 missions, as well as gamma-ray and optical data, are shown to compare favorably with principal features of this model. Several further observational tests are suggested for establishing the validity of this scenario for AGN spectral evolution

  2. Burning mouth disorder

    Directory of Open Access Journals (Sweden)

    Anand Bala

    2012-01-01

    Full Text Available Burning mouth disorder (BMD is a burning or stinging sensation affecting the oral mucosa, lips and/or tongue, in the absence of clinically visible mucosal lesions. There is a strong female predilection, with the age of onset being approximately 50 years. Affected patients often present with multiple oral complaints, including burning, dryness and taste alterations. The causes of BMD are multifactorial and remain poorly understood. Recently, there has been a resurgence of interest in this disorder with the discovery that the pain of burning mouth syndrome (BMS may be neuropathic in origin and originate both centrally and peripherally. The most common sites of burning are the anterior tongue, anterior hard palate and lower lip, but the distribution of oral sites affected does not appear to affect the natural history of the disorder or the response to treatment BMS may persist for many years. This article provides updated information on BMS and presents a new model, based on taste dysfunction, for its pathogenesis.

  3. Revisiting the Short-term X-ray Spectral Variability of NGC 4151 with Chandra

    Science.gov (United States)

    Wang, Junfeng; Risaliti, G.; Fabbiano, G.; Elvis, M.; Zezas, A.; Karovska, M.

    2010-05-01

    We present new X-ray spectral data for the Seyfert 1 nucleus in NGC 4151 observed with Chandra for ~200 ks. A significant ACIS pileup is present, resulting in a nonlinear count rate variation during the observation. With pileup corrected spectral fitting, we are able to recover the spectral parameters and find consistency with those derived from unpiled events in the ACIS readout streak and outer region from the bright nucleus. The absorption corrected 2-10 keV flux of the nucleus varied between 6 × 10-11 erg s-1 cm-2 and 10-10 erg s-1 cm-2 (L 2-10 keV ~ 1.3-2.1 × 1042 erg s-1). Similar to earlier Chandra studies of NGC 4151 at a historical low state, the photon indices derived from the same absorbed power-law model are Γ ~ 0.7-0.9. However, we show that Γ is highly dependent on the adopted spectral models. Fitting the power-law continuum with a Compton reflection component gives Γ ~ 1.1. By including passage of non-uniform X-ray obscuring clouds, we can reproduce the apparent flat spectral states with Γ ~ 1.7, typical for Seyfert 1 active galactic nuclei. The same model also fits the hard spectra from previous ASCA "long look" observation of NGC 4151 in the lowest flux state. The spectral variability during our observation can be interpreted as variations in intrinsic soft continuum flux relative to a Compton reflection component that is from distant cold material and constant on short timescale, or variations of partially covering absorber in the line of sight toward the nucleus. An ionized absorber model with ionization parameter log ξ ~ 0.8-1.1 can also fit the low-resolution ACIS spectra. If the partial covering model is correct, adopting a black hole mass M_{BH}˜ 4.6× 10^7 M sun we constrain the distance of the obscuring cloud from the central black hole to be r <~ 9 lt-day, consistent with the size of the broad emission line region of NGC 4151 from optical reverberation mapping.

  4. REVISITING THE SHORT-TERM X-RAY SPECTRAL VARIABILITY OF NGC 4151 WITH CHANDRA

    International Nuclear Information System (INIS)

    Wang Junfeng; Fabbiano, G.; Elvis, M.; Zezas, A.; Karovska, M.; Risaliti, G.

    2010-01-01

    We present new X-ray spectral data for the Seyfert 1 nucleus in NGC 4151 observed with Chandra for ∼200 ks. A significant ACIS pileup is present, resulting in a nonlinear count rate variation during the observation. With pileup corrected spectral fitting, we are able to recover the spectral parameters and find consistency with those derived from unpiled events in the ACIS readout streak and outer region from the bright nucleus. The absorption corrected 2-10 keV flux of the nucleus varied between 6 x 10 -11 erg s -1 cm -2 and 10 -10 erg s -1 cm -2 (L 2-10 k eV ∼ 1.3-2.1 x 10 42 erg s -1 ). Similar to earlier Chandra studies of NGC 4151 at a historical low state, the photon indices derived from the same absorbed power-law model are Γ ∼ 0.7-0.9. However, we show that Γ is highly dependent on the adopted spectral models. Fitting the power-law continuum with a Compton reflection component gives Γ ∼ 1.1. By including passage of non-uniform X-ray obscuring clouds, we can reproduce the apparent flat spectral states with Γ ∼ 1.7, typical for Seyfert 1 active galactic nuclei. The same model also fits the hard spectra from previous ASCA 'long look' observation of NGC 4151 in the lowest flux state. The spectral variability during our observation can be interpreted as variations in intrinsic soft continuum flux relative to a Compton reflection component that is from distant cold material and constant on short timescale, or variations of partially covering absorber in the line of sight toward the nucleus. An ionized absorber model with ionization parameter log ξ ∼ 0.8-1.1 can also fit the low-resolution ACIS spectra. If the partial covering model is correct, adopting a black hole mass M BH ∼4.6x10 7 M sun we constrain the distance of the obscuring cloud from the central black hole to be r ∼< 9 lt-day, consistent with the size of the broad emission line region of NGC 4151 from optical reverberation mapping.

  5. Giant Black Hole Rips Apart Star

    Science.gov (United States)

    2004-02-01

    was equivalent to a supernova. "Now, with all the data in hand, we have the smoking gun proof that this spectacular event has occurred," said coauthor Günther Hasinger, also of MPE. The black hole in the center of RX J1242-11 is estimated to have a mass of about 100 million times Earth's Sun. By contrast, the destroyed star probably had a mass about equal to the Sun, making it a lopsided battle of gravity. "This is the ultimate David versus Goliath battle, but here David loses," said Hasinger. The astronomers estimated about one percent of the star's mass was ultimately consumed, or accreted, by the black hole. This small amount is consistent with predictions that the momentum and energy of the accretion process will cause most of the destroyed star's gas to be flung away from the black hole. XMM-Newton Spectrum &Illustration of RX J1242-11 XMM-Newton Spectrum & Illustration of RX J1242-11 The force that disrupted the star in RX J1242-11 is an extreme example of the tidal force caused by differences in gravity acting on the front and back of an object. The tidal force from the Moon causes tides in Earth's oceans. A tidal force from Jupiter pulled Comet Shoemaker-Levy apart, before it plunged into the giant planet. The odds stellar tidal disruption will happen in a typical galaxy are low, about one in 10,000 annually. If it happened at the center of the Milky Way Galaxy, 26,000 light-years from Earth, the resulting X-ray outburst would be about 50,000 times brighter than the brightest X-ray source in our galaxy, beside the Sun, but it would not pose a threat to Earth. Other dramatic flares have been seen from galaxies, but this is the first studied with the high-spatial resolution of Chandra and the high-spectral resolution of XMM-Newton. Both instruments made a critical advance. Chandra showed the RX J1242-11 event occurred in the center of a galaxy, where the black hole lurks. The XMM-Newton spectrum revealed the fingerprints expected for the surroundings of a black

  6. Survival after burn in a sub-Saharan burn unit: Challenges and opportunities

    Science.gov (United States)

    Tyson, Anna F.; Boschini, Laura P.; Kiser, Michelle M.; Samuel, Jonathan C.; Mjuweni, Steven N.; Cairns, Bruce A.; Charles, Anthony G.

    2013-01-01

    Background Burns are among the most devastating of all injuries and a major global public health crisis, particularly in sub-Saharan Africa. In developed countries, aggressive management of burns continues to lower overall mortality and increase lethal total body surface area (TBSA) at which 50% of patients die (LA50). However, lack of resources and inadequate infrastructure significantly impede such improvements in developing countries. Methods This study is a retrospective analysis of patients admitted to the burn center at Kamuzu Central Hospital in Lilongwe, Malawi between June 2011 and December 2012. We collected information including patient age, gender, date of admission, mechanism of injury, time to presentation to hospital, total body surface area (TBSA) burn, comorbidities, date and type of operative procedures, date of discharge, length of hospital stay, and survival. We then performed bivariate analysis and logistic regression to identify characteristics associated with increased mortality. Results A total of 454 patients were admitted during the study period with a median age of 4 years (range 0.5 months to 79 years). Of these patients, 53% were male. The overall mean TBSA was 18.5%, and average TBSA increased with age—17% for 0–18 year olds, 24% for 19–60 year olds, and 41% for patients over 60 years old. Scald and flame burns were the commonest mechanisms, 52% and 41% respectively, and flame burns were associated with higher mortality. Overall survival in this population was 82%; however survival reduced with increasing age categories (84% in patients 0–18 years old, 79% in patients 19–60 years old, and 36% in patients older than 60 years). TBSA remained the strongest predictor of mortality after adjusting for age and mechanism of burn. The LA50 for this population was 39% TBSA. Discussion Our data reiterate that burn in Malawi is largely a pediatric disease and that the high burn mortality and relatively low LA50 have modestly improved

  7. Study on the Gap Flow Simulation in EDM Small Hole Machining with Ti Alloy

    Directory of Open Access Journals (Sweden)

    Shengfang Zhang

    2017-01-01

    Full Text Available In electrical discharge machining (EDM process, the debris removed from electrode material strongly affects the machining efficiency and accuracy, especially for the deep small hole machining process. In case of Ti alloy, the debris movement and removal process in gap flow between electrodes for small hole EDM process is studied in this paper. Based on the solid-liquid two-phase flow equation, the mathematical model on the gap flow field with flushing and self-adaptive disturbation is developed. In our 3D simulation process, the count of debris increases with number of EDM discharge cycles, and the disturbation generated by the movement of self-adaptive tool in the gap flow is considered. The methods of smoothing and remeshing are also applied in the modeling process to enable a movable tool. Under different depth, flushing velocity, and tool diameter, the distribution of velocity field, pressure field of gap flow, and debris movement are analyzed. The statistical study of debris distribution under different machining conditions is also carried out. Finally, a series of experiments are conducted on a self-made machine to verify the 3D simulation model. The experiment results show the burn mark at hole bottom and the tapered wall, which corresponds well with the simulating conclusion.

  8. Children with burns referred for child abuse evaluation: Burn characteristics and co-existent injuries.

    Science.gov (United States)

    Pawlik, Marie-Christin; Kemp, Alison; Maguire, Sabine; Nuttall, Diane; Feldman, Kenneth W; Lindberg, Daniel M

    2016-05-01

    Intentional burns represent a serious form of physical abuse that must be identified to protect children from further harm. This study is a retrospectively planned secondary analysis of the Examining Siblings To Recognize Abuse (ExSTRA) network data. Our objective was to describe the characteristics of burns injuries in children referred to Child Abuse Pediatricians (CAPs) in relation to the perceived likelihood of abuse. We furthermore compare the extent of diagnostic investigations undertaken in children referred to CAPs for burn injuries with those referred for other reasons. Within this dataset, 7% (215/2890) of children had burns. Children with burns were older than children with other injuries (median age 20 months vs. 10 months). Physical abuse was perceived as likely in 40.9% (88) and unlikely in 59.1% (127). Scalds accounted for 52.6% (113) and contact burns for 27.6% (60). Several characteristics of the history and burn injury were associated with a significantly higher perceived likelihood of abuse, including children with reported inflicted injury, absent or inadequate explanation, hot water as agent, immersion scald, a bilateral/symmetric burn pattern, total body surface area ≥10%, full thickness burns, and co-existent injuries. The rates of diagnostic testing were significantly lower in children with burns than other injuries, yet the yield of skeletal survey and hepatic transaminases testing were comparable between the two groups. This would imply that children referred to CAPs for burns warrant the same level of comprehensive investigations as those referred for other reasons. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. A Dancing Black Hole

    Science.gov (United States)

    Shoemaker, Deirdre; Smith, Kenneth; Schnetter, Erik; Fiske, David; Laguna, Pablo; Pullin, Jorge

    2002-04-01

    Recently, stationary black holes have been successfully simulated for up to times of approximately 600-1000M, where M is the mass of the black hole. Considering that the expected burst of gravitational radiation from a binary black hole merger would last approximately 200-500M, black hole codes are approaching the point where simulations of mergers may be feasible. We will present two types of simulations of single black holes obtained with a code based on the Baumgarte-Shapiro-Shibata-Nakamura formulation of the Einstein evolution equations. One type of simulations addresses the stability properties of stationary black hole evolutions. The second type of simulations demonstrates the ability of our code to move a black hole through the computational domain. This is accomplished by shifting the stationary black hole solution to a coordinate system in which the location of the black hole is time dependent.

  10. Monitoring the Black Hole Binary GRS 1758-258 with INTEGRAL and RXTE

    Science.gov (United States)

    Pottschmidt, Katja; Chernyakova, Masha; Lubinski, Piotr; Migliari, Simone; Smith, David M.; Zdziarski, Andrzej A.; Tomsick, John A.; Bezayiff, N.; Kreykenbohm, Ingo; Kretschmar, Peter; hide

    2008-01-01

    The microquasar GRS 1758-258 is one of only three persistent black hole binaries that spend most of their time in the hard spectral state, the other two being Cyg X-l and 1E 1741.7-2942. It therefore provides the rare opportunity for an extensive long term study of this important black hole state which is associated with strong variability and radio jet emission. INTEGRAL has been monitoring the source since the first Galactic Center Deep Exposure season in spring 2003 during two 2-3 months long Galactic Center viewing epochs each year, amounting to 11 epochs including spring of 2008. With the exception of the last epoch quasi-simultaneous RXTE monitoring observations are available as well. Here we present an analysis of the epoch averaged broad band spectra which display considerable long term variability, most notably the occurrence of two soft/off states, extreme examples for the hysteretic behavior of black hole binaries. The hard source spectrum and long exposures allow us to extend the analysis for several epochs to approximately 800 keV using PICsIT data and address the question of the presence of a non-thermal Comptonization component.

  11. XFEM Modelling of Multi-holes Plate with Single-row and Staggered Holes Configurations

    Directory of Open Access Journals (Sweden)

    Supar Khairi

    2017-01-01

    Full Text Available Joint efficiency is the key to composite structures assembly design, good structures response is dependent upon multi-holes behavior as subjected to remote loading. Current benchmarking work were following experimental testing series taken from literature on multi-holes problem. Eleven multi-hole configurations were investigated with various pitch and gage distance of staggered holes and non-staggered holes (single-row holes. Various failure modes were exhibited, most staggered holes demonstrates staggered crack path but non-staggered holes series displayed crack path along net-section plane. Stress distribution were carried out and good agreement were exhibited in experimental observation as reported in the respective literature. Consequently, strength prediction work were carried out under quasi-static loading, most showed discrepancy between 8% -31%, better prediction were exhibited in thicker and non-staggered holes plate combinations.

  12. Multi-time-scale X-ray reverberation mapping of accreting black holes

    Science.gov (United States)

    Mastroserio, Guglielmo; Ingram, Adam; van der Klis, Michiel

    2018-04-01

    Accreting black holes show characteristic reflection features in their X-ray spectrum, including an iron Kα line, resulting from hard X-ray continuum photons illuminating the accretion disc. The reverberation lag resulting from the path-length difference between direct and reflected emission provides a powerful tool to probe the innermost regions around both stellar-mass and supermassive black holes. Here, we present for the first time a reverberation mapping formalism that enables modelling of energy-dependent time lags and variability amplitude for a wide range of variability time-scales, taking the complete information of the cross-spectrum into account. We use a pivoting power-law model to account for the spectral variability of the continuum that dominates over the reverberation lags for longer time-scale variability. We use an analytic approximation to self-consistently account for the non-linear effects caused by this continuum spectral variability, which have been ignored by all previous reverberation studies. We find that ignoring these non-linear effects can bias measurements of the reverberation lags, particularly at low frequencies. Since our model is analytic, we are able to fit simultaneously for a wide range of Fourier frequencies without prohibitive computational expense. We also introduce a formalism of fitting to real and imaginary parts of our cross-spectrum statistic, which naturally avoids some mistakes/inaccuracies previously common in the literature. We perform proof-of-principle fits to Rossi X-ray Timing Explorer data of Cygnus X-1.

  13. Foot burns: epidemiology and management.

    Science.gov (United States)

    Hemington-Gorse, S; Pellard, S; Wilson-Jones, N; Potokar, T

    2007-12-01

    This is a retrospective study of the epidemiology and management of isolated foot burns presenting to the Welsh Centre for Burns from January 1998 to December 2002. A total of 289 were treated of which 233 were included in this study. Approximately 40% were in the paediatric age group and the gender distribution varied dramatically for adults and children. In the adult group the male:female ratio was 3.5:1, however in the paediatric group the male:female ratio was more equal (1.6:1). Scald burns (65%) formed the largest group in children and scald (35%) and chemical burns (32%) in adults. Foot burns have a complication rate of 18% and prolonged hospital stay. Complications include hypertrophic scarring, graft loss/delayed healing and wound infection. Although isolated foot burns represent a small body surface area, over half require treatment as in patients to allow for initial aggressive conservative management of elevation and regular wound cleansing to avoid complications. This study suggests a protocol for the initial acute management of foot burns. This protocol states immediate referral of all foot burns to a burn centre, admission of these burns for 24-48 h for elevation, regular wound cleansing with change of dressings and prophylactic antibiotics.

  14. Microbiological Monitoring and Proteolytic Study of Clinical Samples From Burned and Burned Wounded Patients

    International Nuclear Information System (INIS)

    Toema, M.A.; El-Bazza, Z.E.; El-Hifnawi, H.N.; Abd-El-Hakim, E.E.

    2013-01-01

    In this study, clinical samples were collected from 100 patients admitted to Burn and Plastic Surgery Department, Faculty of Medicine, Ain Shams University, Egypt, over a period of 12 months. The proteolytic activity of 110 clinical samples taken from surfaces swabs which taken from burned and burned wounded patients with different ages and gender was examined. Screening for the proteolytic activity produced by pathogenic bacteria isolated from burned and burned wounded patients was evaluated as gram positive Bacilli and gram negative bacilli showed high proteolytic activity (46.4%) while 17.9% showed no activity. The isolated bacteria proved to have proteolytic activity were classified into high, moderate and weak. The pathogenic bacteria isolated from burned and burned wounded patients and showing proteolytic activity were identified as Pseudomonas aeruginosa, Proteus mirabilis, Proteus vulgaris, Bacillus megaterium, Bacillus cereus, Staphylococcus aureus, Escherichia coli, Klebsiella ozaeanae, Klebsiella oxytoca, Klebsiella pneumoniae and Pseudomonas fluoresces.

  15. EVENT HORIZON TELESCOPE EVIDENCE FOR ALIGNMENT OF THE BLACK HOLE IN THE CENTER OF THE MILKY WAY WITH THE INNER STELLAR DISK

    International Nuclear Information System (INIS)

    Psaltis, Dimitrios; Narayan, Ramesh; Loeb, Abraham; Doeleman, Sheperd S.; Fish, Vincent L.; Broderick, Avery E.

    2015-01-01

    Observations of the black hole in the center of the Milky Way with the Event Horizon Telescope at 1.3 mm have revealed a size of the emitting region that is smaller than the size of the black-hole shadow. This can be reconciled with the spectral properties of the source, if the accretion flow is seen at a relatively high inclination (50°-60°). Such an inclination makes the angular momentum of the flow, and perhaps of the black hole, nearly aligned with the angular momenta of the orbits of stars that lie within ≅ 3'' from the black hole. We discuss the implications of such an alignment for the properties of the black hole and of its accretion flow. We argue that future Event Horizon Telescope observations will not only refine the inclination of Sgr A* but also measure precisely its orientation on the plane of the sky

  16. EVENT HORIZON TELESCOPE EVIDENCE FOR ALIGNMENT OF THE BLACK HOLE IN THE CENTER OF THE MILKY WAY WITH THE INNER STELLAR DISK

    Energy Technology Data Exchange (ETDEWEB)

    Psaltis, Dimitrios [Astronomy Department, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Narayan, Ramesh; Loeb, Abraham; Doeleman, Sheperd S. [Harvard-Smithsonian CfA, 60 Garden Street, Cambridge, MA 02138 (United States); Fish, Vincent L. [Massachusetts Institute of Technology, Haystack Observatory, Route 40, Westford, MA 01886 (United States); Broderick, Avery E., E-mail: dpsaltis@email.arizona.edu, E-mail: rnarayan@cfa.harvard.edu, E-mail: abroderick@perimeterinstitute.ca [Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo, ON, N2L 2Y5 (Canada)

    2015-01-01

    Observations of the black hole in the center of the Milky Way with the Event Horizon Telescope at 1.3 mm have revealed a size of the emitting region that is smaller than the size of the black-hole shadow. This can be reconciled with the spectral properties of the source, if the accretion flow is seen at a relatively high inclination (50°-60°). Such an inclination makes the angular momentum of the flow, and perhaps of the black hole, nearly aligned with the angular momenta of the orbits of stars that lie within ≅ 3'' from the black hole. We discuss the implications of such an alignment for the properties of the black hole and of its accretion flow. We argue that future Event Horizon Telescope observations will not only refine the inclination of Sgr A* but also measure precisely its orientation on the plane of the sky.

  17. Spatial frequency domain imaging of burn wounds in a preclinical model of graded burn severity

    Science.gov (United States)

    Nguyen, John Quan; Crouzet, Christian; Mai, Tuan; Riola, Kathleen; Uchitel, Daniel; Liaw, Lih-Huei; Bernal, Nicole; Ponticorvo, Adrien; Choi, Bernard; Durkin, Anthony J.

    2013-06-01

    Frequent monitoring of early-stage burns is necessary for deciding optimal treatment and management. Both superficial and full thickness burns are relatively easy to diagnose based on clinical observation. In between these two extremes are superficial-partial thickness and deep-partial thickness burns. These burns, while visually similar, differ dramatically in terms of clinical treatment and are known to progress in severity over time. The objective of this study was to determine the potential of spatial frequency domain imaging (SFDI) for noninvasively mapping quantitative changes in chromophore and optical properties that may be an indicative of burn wound severity. A controlled protocol of graded burn severity was developed and applied to 17 rats. SFDI data was acquired at multiple near-infrared wavelengths over a course of 3 h. Burn severity was verified using hematoxylin and eosin histology. From this study, we found that changes in water concentration (edema), deoxygenated hemoglobin concentration, and optical scattering (tissue denaturation) to be statistically significant at differentiating superficial partial-thickness burns from deep-partial thickness burns.

  18. Epidemiology of burns throughout the World. Part II: intentional burns in adults.

    Science.gov (United States)

    Peck, Michael D

    2012-08-01

    A significant number of burns and deaths from fire are intentionally wrought. Rates of intentional burns are unevenly distributed throughout the world; India has a particularly high rate in young women whereas in Europe rates are higher in men in mid-life. Data from hospitalized burn patients worldwide reveal incidence rates for assault by fire and scalds ranging from 3% to 10%. The average proportion of the body surface area burned in an assault by fire or scalds is approximately 20%. In different parts of the world, attempted burning of others or oneself can be attributed to different motives. Circumstances under which assaults occur fall largely into the categories of interpersonal conflict, including spousal abuse, elder abuse, or interactions over contentious business transactions. Contributing social factors to assaults by burning include drug and alcohol abuse, non-constructive use of leisure time, non-participation in religious and community activities, unstable relationships, and extramarital affairs. Although the incidence of self-mutilation and suicide attempts by burning are relatively low, deliberate self-harm carries a significant risk of death, with an overall mortality rate of 65% worldwide. In those who resort to self-immolation, circumstantial themes reflect domestic discord, family dysfunction, and the social ramifications of unemployment. Preventing injurious burn-related violence requires a multifaceted approach, including legislation and enforcement, education, and advocacy. Better standardized assessment tools are needed to screen for risks of abuse and for psychiatric disorders in perpetrators. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

  19. Burning mouth syndrome

    OpenAIRE

    K A Kamala; S Sankethguddad; S G Sujith; Praveena Tantradi

    2016-01-01

    Burning mouth syndrome (BMS) is multifactorial in origin which is typically characterized by burning and painful sensation in an oral cavity demonstrating clinically normal mucosa. Although the cause of BMS is not known, a complex association of biological and psychological factors has been identified, suggesting the existence of a multifactorial etiology. As the symptom of oral burning is seen in various pathological conditions, it is essential for a clinician to be aware of how to different...

  20. Adult survivors' lived experience of burns and post-burn health: A qualitative analysis.

    Science.gov (United States)

    Abrams, Thereasa E; Ogletree, Roberta J; Ratnapradipa, Dhitinut; Neumeister, Michael W

    2016-02-01

    The individual implications of major burns are likely to affect the full spectrum of patients' physical, emotional, psychological, social, environmental, spiritual and vocational health. Yet, not all of the post-burn health implications are inevitably negative. Utilizing a qualitative approach, this heuristic phenomenological study explores the experiences and perceptions early (ages 18-35) and midlife (ages 36-64) adults providing insight for how participants perceived their burns in relationship to their post-burn health. Participants were interviewed using semi-structured interview questions framed around seven domains of health. Interview recordings were transcribed verbatim then coded line by line, identifying dominant categories related to health. Categories were analyzed identifying shared themes among the study sample. Participants were Caucasian, seven males and one female. Mean age at time of interviews was 54.38 and 42.38 at time of burns. Mean time since burns occurred was 9.38 years with a minimum of (20%) total body surface area (TBSA) burns. Qualitative content analysis rendered three emergent health-related categories and associated themes that represented shared meanings within the participant sample. The category of "Physical Health" reflected the theme physical limitations, pain and sensitivity to temperature. Within the category of "Intellectual Health" were themes of insight, goal setting and self-efficacy, optimism and humor and within "Emotional Health" were the themes empathy and gratitude. By exploring subjective experiences and perceptions of health shared through dialog with experienced burned persons, there are opportunities to develop a more complete picture of how holistic health may be affected by major burns that in turn could support future long-term rehabilitative trajectories of early and midlife adult burn patients. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

  1. Black holes will break up solitons and white holes may destroy them

    International Nuclear Information System (INIS)

    Akbar, Fiki T.; Gunara, Bobby E.; Susanto, Hadi

    2017-01-01

    Highlights: • What happens if a soliton collides with a black or white hole? • Solitons can pass through black hole horizons, but they will break up into several solitons after the collision. • In the interaction with a white hole horizon, solitons either pass through the horizon or will be destroyed by it. - Abstract: We consider a quantum analogue of black holes and white holes using Bose–Einstein condensates. The model is described by the nonlinear Schrödinger equation with a ‘stream flow’ potential, that induces a spatial translation to standing waves. We then mainly consider the dynamics of dark solitons in a black hole or white hole flow analogue and their interactions with the event horizon. A reduced equation describing the position of the dark solitons was obtained using variational method. Through numerical computations and comparisons with the analytical approximation we show that solitons can pass through black hole horizons even though they will break up into several solitons after the collision. In the interaction with a white hole horizon, we show that solitons either pass through the horizon or will be destroyed by it.

  2. Black holes will break up solitons and white holes may destroy them

    Energy Technology Data Exchange (ETDEWEB)

    Akbar, Fiki T., E-mail: ftakbar@fi.itb.ac.id [Theoretical Physics Laboratory, Theoretical High Energy Physics and Instrumentation Research Group, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha no. 10, Bandung, 40132 (Indonesia); Gunara, Bobby E., E-mail: bobby@fi.itb.ac.id [Theoretical Physics Laboratory, Theoretical High Energy Physics and Instrumentation Research Group, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha no. 10, Bandung, 40132 (Indonesia); Susanto, Hadi, E-mail: hsusanto@essex.ac.uk [Department of Mathematical Sciences, University of Essex, Colchester, CO4 3SQ (United Kingdom)

    2017-06-15

    Highlights: • What happens if a soliton collides with a black or white hole? • Solitons can pass through black hole horizons, but they will break up into several solitons after the collision. • In the interaction with a white hole horizon, solitons either pass through the horizon or will be destroyed by it. - Abstract: We consider a quantum analogue of black holes and white holes using Bose–Einstein condensates. The model is described by the nonlinear Schrödinger equation with a ‘stream flow’ potential, that induces a spatial translation to standing waves. We then mainly consider the dynamics of dark solitons in a black hole or white hole flow analogue and their interactions with the event horizon. A reduced equation describing the position of the dark solitons was obtained using variational method. Through numerical computations and comparisons with the analytical approximation we show that solitons can pass through black hole horizons even though they will break up into several solitons after the collision. In the interaction with a white hole horizon, we show that solitons either pass through the horizon or will be destroyed by it.

  3. Burn-related factors affecting anxiety, depression and self-esteem in burn patients: an exploratory study.

    Science.gov (United States)

    Jain, M; Khadilkar, N; De Sousa, A

    2017-03-31

    Burns are physically, psychologically and economically challenging injuries, and the factors leading to them are many and under-studied. The aim of the current study was to assess level of anxiety, depression and self-esteem in burn patients, and look at various burn-related variables that affect them. This cross-sectional study included 100 patients with burn injuries admitted to a tertiary care private hospital in an urban metropolis in India. The patients were assessed for anxiety, depression and self-esteem using the Hamilton anxiety rating scale, Hamilton depression rating scale and Rosenberg self-esteem scale respectively. Assessment was carried out within 2-8 weeks of injury following medical stabilization. The data was tabulated and statistically analyzed. The study sample was predominantly male (54%), married (69%), with a mean age of 34.1 ± 10.8 years. Accidental burns (94%) were the most common modality of injury. The majority (46%) suffered burns involving 20-59% total body surface area (TBSA), and facial burns were present (57%). No significant association was found between TBSA and anxiety, depression or self-esteem, and the same was true for facial burns. Deep burns, however, were significantly associated with anxiety (p=0.03) and depression (p=0.0002). High rates of anxiety and depression are associated with burn injuries and related to burn depth. Adjustment and recovery in these patients depends on various other factors like the patient's psychological status, nature/extent of the injury and ensuing medical care. Further research is warranted to reveal the magnitude and predictors of psychological problems in burn patients.

  4. Caged black holes: Black holes in compactified spacetimes. I. Theory

    International Nuclear Information System (INIS)

    Kol, Barak; Sorkin, Evgeny; Piran, Tsvi

    2004-01-01

    In backgrounds with compact dimensions there may exist several phases of black objects including a black hole and a black string. The phase transition between them raises questions and touches on fundamental issues such as topology change, uniqueness, and cosmic censorship. No analytic solution is known for the black hole, and moreover one can expect approximate solutions only for very small black holes, while phase transition physics happens when the black hole is large. Hence we turn to numerical solutions. Here some theoretical background to the numerical analysis is given, while the results will appear in a subsequent paper. The goals for a numerical analysis are set. The scalar charge and tension along the compact dimension are defined and used as improved order parameters which put both the black hole and the black string at finite values on the phase diagram. The predictions for small black holes are presented. The differential and the integrated forms of the first law are derived, and the latter (Smarr's formula) can be used to estimate the 'overall numerical error'. Field asymptotics and expressions for physical quantities in terms of the numerical values are supplied. The techniques include the 'method of equivalent charges', free energy, dimensional reduction, and analytic perturbation for small black holes

  5. Radiative modeling and characterization of aerosol plumes hyper-spectral imagery

    International Nuclear Information System (INIS)

    Alakian, A.

    2008-03-01

    This thesis aims at characterizing aerosols from plumes (biomass burning, industrial discharges, etc.) with hyper-spectral imagery. We want to estimate the optical properties of emitted particles and also their micro-physical properties such as number, size distribution and composition. To reach our goal, we have built a forward semi-analytical model, named APOM (Aerosol Plume Optical Model), which allows to simulate the radiative effects of aerosol plumes in the spectral range [0,4-2,5 μm] for nadir viewing sensors. Mathematical formulation and model coefficients are obtained from simulations performed with the radiative transfer code COMANCHE. APOM is assessed on simulated data and proves to be accurate with modeling errors between 1% and 3%. Three retrieval methods using APOM have been developed: L-APOM, M-APOM and A-APOM. These methods take advantage of spectral and spatial dimensions in hyper-spectral images. L-APOM and M-APOM assume a priori knowledge on particles but can estimate their optical and micro-physical properties. Their performances on simulated data are quite promising. A-APOM method does not require any a priori knowledge on particles but only estimates their optical properties. However, it still needs improvements before being usable. On real images, inversion provides satisfactory results for plumes above water but meets some difficulties for plumes above vegetation, which underlines some possibilities of improvement for the retrieval algorithm. (author)

  6. Alternate Explosions: Collapse and Accretion Events with Red Holes instead of Black Holes

    OpenAIRE

    Graber, James S.

    1999-01-01

    A red hole is "just like a black hole" except it lacks an event horizon and a singularity. As a result, a red hole emits much more energy than a black hole during a collapse or accretion event. We consider how a red hole solution can solve the "energy crisis" and power extremely energetic gamma ray bursts and hypernovae.

  7. A magnetic model for low/hard state of black hole binaries

    Science.gov (United States)

    Ye, Yong-Chun; Wang, Ding-Xiong; Huang, Chang-Yin; Cao, Xiao-Feng

    2016-03-01

    A magnetic model for the low/hard state (LHS) of two black hole X-ray binaries (BHXBs), H1743-322 and GX 339-4, is proposed based on transport of the magnetic field from a companion into an accretion disk around a black hole (BH). This model consists of a truncated thin disk with an inner advection-dominated accretion flow (ADAF). The spectral profiles of the sources are fitted in agreement with the data observed at four different dates corresponding to the rising phase of the LHS. In addition, the association of the LHS with a quasi-steady jet is modeled based on transport of magnetic field, where the Blandford-Znajek (BZ) and Blandford-Payne (BP) processes are invoked to drive the jets from BH and inner ADAF. It turns out that the steep radio/X-ray correlations observed in H1743-322 and GX 339-4 can be interpreted based on our model.

  8. A high-resolution two-pulse coherent anti-Stokes Raman scattering spectrum using a spectral amplitude modulation

    International Nuclear Information System (INIS)

    Lu, Chenhui; Zhang, Shian; Wu, Meizhen; Jia, Tianqing; Sun, Zhenrong; Qiu, Jianrong

    2013-01-01

    Femtosecond coherent anti-Stokes Raman scattering (CARS) spectra suffer from low spectral resolution because of the broadband laser spectrum. In this paper, we propose a feasible scheme to achieve a high-resolution two-pulse CARS spectrum by shaping both the pump and probe pulses using rectangular amplitude modulation. We show that a narrowband hole in the CARS spectrum can be created by the amplitude-shaped laser pulse, the position of which is correlated with the Raman resonant frequency of the molecule. Thus, by observing holes in the CARS spectrum, we are able to obtain a high-resolution CARS spectrum and the energy-level diagram of the molecule. (paper)

  9. Black and white holes

    International Nuclear Information System (INIS)

    Zeldovich, Ya.; Novikov, I.; Starobinskij, A.

    1978-01-01

    The theory is explained of the origination of white holes as a dual phenomenon with regard to the formation of black holes. Theoretically it is possible to derive the white hole by changing the sign of time in solving the general theory of relativity equation implying the black hole. The white hole represents the amount of particles formed in the vicinity of a singularity. For a distant observer, matter composed of these particles expands and the outer boundaries of this matter approach from the inside the gravitational radius Rsub(r). At t>>Rsub(r)/c all radiation or expulsion of matter terminates. For the outside observer the white hole exists for an unlimited length of time. In fact, however, it acquires the properties of a black hole and all processes in it cease. The qualitative difference between a white hole and a black hole is in that a white hole is formed as the result of an inner quantum explosion from the singularity to the gravitational radius and not as the result of a gravitational collapse, i.e., the shrinkage of diluted matter towards the gravitational radius. (J.B.)

  10. Black and white holes

    Energy Technology Data Exchange (ETDEWEB)

    Zeldovich, Ya; Novikov, I; Starobinskii, A

    1978-07-01

    The theory is explained of the origination of white holes as a dual phenomenon with regard to the formation of black holes. Theoretically it is possible to derive the white hole by changing the sign of time in solving the general theory of relativity equation implying the black hole. The white hole represents the amount of particles formed in the vicinity of a singularity. For a distant observer, matter composed of these particles expands and the outer boundaries of this matter approach from the inside the gravitational radius R/sub r/. At t>>R/sub r//c all radiation or expulsion of matter terminates. For the outside observer the white hole exists for an unlimited length of time. In fact, however, it acquires the properties of a black hole and all processes in it cease. The qualitative difference between a white hole and a black hole is in that a white hole is formed as the result of an inner quantum explosion from the singularity to the gravitational radius and not as the result of a gravitational collapse, i.e., the shrinkage of diluted matter towards the gravitational radius.

  11. Observation of a hole-size-dependent energy shift of the surface-plasmon resonance in Ni antidot thin films

    Energy Technology Data Exchange (ETDEWEB)

    Fang, H.; Akinoglu, E. M.; Fumagalli, P., E-mail: paul.fumagalli@fu-berlin.de [Institut für Experimentalphysik, Freie Universität Berlin, 14195 Berlin (Germany); Caballero, B.; García-Martín, A. [IMM-Instituto de Microelectrónica de Madrid (CNM-CSIC), Isaac Newton 8, PTM, Tres Cantos, E-28760 Madrid (Spain); Papaioannou, E. Th. [Fachbereich Physik and Landesforschungszentrum OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern (Germany); Cuevas, J. C. [Departamento de Física Teórica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Giersig, M. [Institut für Experimentalphysik, Freie Universität Berlin, 14195 Berlin (Germany); Helmholtz Zentrum Berlin, Institute of Nanoarchitectures for Energy Conversion, 14195 Berlin (Germany)

    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.

  12. DIFFERENT TYPES OF ULTRALUMINOUS X-RAY SOURCES IN NGC 4631

    International Nuclear Information System (INIS)

    Soria, Roberto; Ghosh, Kajal K.

    2009-01-01

    We have re-examined the most luminous X-ray sources in the starburst galaxy NGC 4631, using XMM-Newton, Chandra, and ROSAT data. The most interesting source is a highly variable supersoft ultraluminous X-ray source (ULX). We suggest that its bolometric luminosity ∼ a few 10 39 erg s -1 in the high/supersoft state: this is an order of magnitude lower than estimated in previous studies, thus reducing the need for extreme or exotic scenarios. Moreover, we find that this source was in a noncanonical low/soft (kT ∼ 0.1-0.3 keV) state during the Chandra observation. By comparing the high and low state, we argue that the spectral properties may not be consistent with the expected behavior of an accreting intermediate-mass black hole. We suggest that recurrent super-Eddington outbursts with photospheric expansion from a massive white dwarf (M wd ∼> 1.3 M sun ), powered by nonsteady nuclear burning, may be a viable possibility, in alternative to the previously proposed scenario of a super-Eddington outflow from an accreting stellar-mass black hole. The long-term average accretion rate required for nuclear burning to power such white-dwarf outbursts in this source and perhaps in other supersoft ULXs is ∼(5-10) x 10 -6 M sun yr -1 : this is comparable to the thermal-timescale mass transfer rate invoked to explain the most luminous hard-spectrum ULXs (powered by black hole accretion). The other four most luminous X-ray sources in NGC 4631 (three of which can be classified as ULXs) appear to be typical accreting black holes, in four different spectral states: high/soft, convex-spectrum, power-law with soft excess, and simple power-law. None of them require masses ∼>50 M sun .

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

    Energy Technology Data Exchange (ETDEWEB)

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

  14. Interaction of non-equilibrium phonons with electron-hole plasmas in germanium

    International Nuclear Information System (INIS)

    Kirch, S.J.

    1985-01-01

    This thesis presents results of experiments on the interaction of phonons and photo-excited electron-hole plasmas in Ge at low temperature. The first two studies involved the low-temperature fluid phase known as the electron-hole liquid (EHL). The third study involved a wider range of temperatures and includes the higher temperature electron-hole plasma (EHP). In the first experiment, superconducting tunnel junctions are used to produce quasi-monochromatic phonons, which propagate through the EHL. The magnitude of the absorption of these non-equilibrium phonons gives a direct measure of the coupling constant, the deformation potential. In the second experiment, the nonequilibrium phonons are generated by laser excitation of a metal film. An unusual sample geometry allows examination of the EHL-phonon interaction near the EHL excitation surface. This coupling is examined for both cw and pulsed EHL excitation. In the third experiment, the phonons are byproducts of the photo-excited carrier thermalization. The spatial, spectral and temporal dependence of the recombination luminescence is examined. A phonon wind force is observed to dominate the transport properties of the EHL and the EHP. These carriers are never observed to move faster than the phonon velocity even during the laser pulse

  15. Treatment of Palm Burns in Children

    OpenAIRE

    Argirova, M.; Hadzhiyski, O.

    2005-01-01

    The timing and methods of treatment of palm burns in children vary widely. From January 2002 to November 2004, 492 children with burns - 125 of them with hand burns or other body burns - were hospitalized and treated at the N.I. Pirogov Clinic for Burns and Plastic Surgery in Bulgaria. Fifty-four children (for a total of 73 burned hands) presented isolated palm burns.Twenty-two hands were operated on. In this review we present the incidence, causes, treatment methods, functional results, and ...

  16. Etiology of Burn Injuries Among 0-6 Aged Children in One University Hospital Burn Unit, Bursa, Turkey

    Directory of Open Access Journals (Sweden)

    Neriman Akansel

    2013-01-01

    Full Text Available Background; Children whose verbal communications are not fully developed are the ones at risk for burn injuries. Causes of burn injuries vary among different age groups and scald injuries are the common cause of burn injuries among children. The majority of burns result from contact with thermal agents such as flame, hot surfaces, or hot liquids.Aim: The aim of this study was to determine etiologic factors of the burn injured children Methods: Data were collected for burn injured children treated in Uludag University Medical Hospital Burn Unit between January 2001 – December 2008. Patients’ demographic variables, etiology of burn injury, TBSA(total body surface area, degree of the burn injury, duration of hospitalization was detected from medical records of the hospitalized patients.Results: The mean age of the children was 2.5±1.5 (median=2. Although 4.6 % of burned patients were under one year of age, most of the children (67.8% were between 1-3 years. All of the patients were burned as a result of accident and house environment was the place where the burn incident occurred. Burn injuries occurredmostly during summer (29.9% and spring (28.7%. Scald injuries (75.3% were mostly seen burn injury types all among other burn injuries.Conclusions: Lack of supervision and observation are usually the most common causes of burn injuries in children. Statistical differences were found among age groups according to their burn etiology (p<0.05. An effect of TBSA on patient survival was statistically significant (p<0.000 and also statistically significant results were seen among age groups according to their TBSA’s (p<0.005.

  17. Non-Quiescent X-ray Emission from Neutron Stars and Black Holes

    Energy Technology Data Exchange (ETDEWEB)

    Tournear, Derek M

    2003-08-18

    X-ray astronomy began with the detection of the persistent source Scorpius X-1. Shortly afterwards, sources were detected that were variable. Centaurus X-2, was determined to be an X-ray transient, having a quiescent state, and a state that was much brighter. As X-ray astronomy progressed, classifications of transient sources developed. One class of sources, believed to be neutron stars, undergo extreme luminosity transitions lasting a few seconds. These outbursts are believed to be thermonuclear explosions occurring on the surface of neutron stars (type I X-ray bursts). Other sources undergo luminosity changes that cannot be explained by thermonuclear burning and last for days to months. These sources are soft X-ray transients (SXTs) and are believed to be the result of instabilities in the accretion of matter onto either a neutron star or black hole. Type I X-ray bursts provide a tool for probing the surfaces of neutron stars. Requiring a surface for the burning has led authors to use the presence of X-ray bursts to rule out the existence of a black hole (where an event horizon exists not a surface) for systems which exhibit type I X-ray bursts. Distinguishing between neutron stars and black holes has been a problem for decades. Narayan and Heyl have developed a theoretical framework to convert suitable upper limits on type I X-ray bursts from accreting black hole candidates (BHCs) into evidence for an event horizon. We survey 2101.2 ks of data from the USA X-ray timing experiment and 5142 ks of data from the Rossi X-ray Timing Explorer (RXTE) experiment to obtain the first formal constraint of this type. 1122 ks of neutron star data yield a population averaged mean burst rate of 1.7 {+-} 0.4 x 10{sup -5} bursts s{sup -1}, while 6081 ks of BHC data yield a 95% confidence level upper limit of 4.9 x 10{sup -7} bursts s{sup -1}. Applying the framework of Narayan and Heyl we calculate regions of luminosity where the neutron stars are expected to burst and the BHCs

  18. Astrophysical black holes

    CERN Document Server

    Gorini, Vittorio; Moschella, Ugo; Treves, Aldo; Colpi, Monica

    2016-01-01

    Based on graduate school lectures in contemporary relativity and gravitational physics, this book gives a complete and unified picture of the present status of theoretical and observational properties of astrophysical black holes. The chapters are written by internationally recognized specialists. They cover general theoretical aspects of black hole astrophysics, the theory of accretion and ejection of gas and jets, stellar-sized black holes observed in the Milky Way, the formation and evolution of supermassive black holes in galactic centers and quasars as well as their influence on the dynamics in galactic nuclei. The final chapter addresses analytical relativity of black holes supporting theoretical understanding of the coalescence of black holes as well as being of great relevance in identifying gravitational wave signals. With its introductory chapters the book is aimed at advanced graduate and post-graduate students, but it will also be useful for specialists.

  19. Hard X-ray spectral and timing properties of IGR J17454-2919 consistent with a black hole in the hard state

    DEFF Research Database (Denmark)

    Tendulkar, Shriharsh P.; Bachetti, Matteo; Tomsick, J.

    2014-01-01

    frequencies. The Lorentzian has a width of 2 Hz and a fractional rms of 25+/-3%. The hard power-law index, the high energy of the cutoff, and the level of variability all are consistent with properties expected for an accreting black hole in the hard state. While we cannot completely rule out the possibility...... of a low magnetic field neutron star, a black hole is more likely....

  20. Optimization of burn referrals

    DEFF Research Database (Denmark)

    Reiband, Hanna K; Lundin, Kira; Alsbjørn, Bjarne

    2014-01-01

    INTRODUCTION: Correct estimation of the severity of burns is important to obtain the right treatment of the patient and to avoid over- and undertriage. In this study we aimed to assess how often the guidelines for referral of burn injured patients are met at the national burn centre (NBC), Denmar...

  1. Optical and magneto-optical properties of the electron-doped and hole-doped C{sub 82} crystal

    Energy Technology Data Exchange (ETDEWEB)

    Rostampour, E., E-mail: el_rostampour@yahoo.com [Plasma Physics Research Center, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Koohi, A. [Plasma Physics and Nuclear Fusion Research School, Nuclear Science and Technology Research Institute, AEOI, Tehran (Iran, Islamic Republic of)

    2015-01-15

    The optical and magnetic properties of the doped C{sub 82} crystal have been investigated by Su–Schrieffer–Heeger (SSH) model, which is based on the Ewald method. When the C{sub 82} molecule is doped with one electron (or hole), a single electron is remained in the energy level that affects the optical and magnetic properties of the C{sub 82} crystal. The lattice and electronic structures of C{sub 82} changed with doping electron (or hole) in the molecule of C{sub 82}. Therefore, polarons are predicted in doped fullerenes. The obtained results showed that the dielectric tensor of the C{sub 82} crystal increased with doping electron (or hole) in the molecule of C{sub 82}. The spectral shapes of the dielectric tensor, circular dichroism and birefringence coefficient of the C{sub 82} crystal turn out to be determined mainly by the geometrical distributions of the pentagons in the fullerene structures.

  2. Incidence and characteristics of chemical burns.

    Science.gov (United States)

    Koh, Dong-Hee; Lee, Sang-Gil; Kim, Hwan-Cheol

    2017-05-01

    Chemical burns can lead to serious health outcomes. Previous studies about chemical burns have been performed based on burn center data so these studies have provided limited information about the incidence of chemical burns at the national level. The aim of this study was to evaluate the incidence and characteristics of chemical burns using nationwide databases. A cohort representing the Korean population, which was established using a national health insurance database, and a nationwide workers' compensation database were used to evaluate the incidence and characteristics of chemical burns. Characteristics of the affected body region, depth of burns, industry, task, and causative agents were analyzed from two databases. The incidence of chemical burns was calculated according to employment status. The most common regions involving chemical burns with hospital visits were the skin followed by the eyes. For skin lesions, the hands and wrists were the most commonly affected regions. Second degree burns were the most common in terms of depth of skin lesions. The hospital visit incidence was 1.96 per 10,000 person-year in the general population. The compensated chemical burns incidence was 0.17 per 10,000 person-year. Employees and the self-employed showed a significantly increased risk of chemical burns undergoing hospital visits compared to their dependents. Chemical burns on the skin and eyes are almost equally prevalent. The working environment was associated with increased risk of chemical burns. Our results may aid in estimating the size of the problem and prioritizing prevention of chemical burns. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

  3. SPECTRAL INDEX AS A FUNCTION OF MASS ACCRETION RATE IN BLACK HOLE SOURCES: MONTE CARLO SIMULATIONS AND AN ANALYTICAL DESCRIPTION

    International Nuclear Information System (INIS)

    Laurent, Philippe; Titarchuk, Lev

    2011-01-01

    We present herein a theoretical study of correlations between spectral indexes of X-ray emergent spectra and mass accretion rate ( m-dot ) in black hole (BH) sources, which provide a definitive signature for BHs. It has been firmly established, using the Rossi X-ray Timing Explorer (RXTE) in numerous BH observations during hard-soft state spectral evolution, that the photon index of X-ray spectra increases when m-dot increases and, moreover, the index saturates at high values of m-dot . In this paper, we present theoretical arguments that the observationally established index saturation effect versus mass accretion rate is a signature of the bulk (converging) flow onto the BH. Also, we demonstrate that the index saturation value depends on the plasma temperature of converging flow. We self-consistently calculate the Compton cloud (CC) plasma temperature as a function of mass accretion rate using the energy balance between energy dissipation and Compton cooling. We explain the observable phenomenon, index- m-dot correlations using a Monte Carlo simulation of radiative processes in the innermost part (CC) of a BH source and we account for the Comptonization processes in the presence of thermal and bulk motions, as basic types of plasma motion. We show that, when m-dot increases, BH sources evolve to high and very soft states (HSS and VSS, respectively), in which the strong blackbody(BB)-like and steep power-law components are formed in the resulting X-ray spectrum. The simultaneous detections of these two components strongly depends on sensitivity of high-energy instruments, given that the relative contribution of the hard power-law tail in the resulting VSS spectrum can be very low, which is why, to date RXTE observations of the VSS X-ray spectrum have been characterized by the presence of the strong BB-like component only. We also predict specific patterns for high-energy e-fold (cutoff) energy (E fold ) evolution with m-dot for thermal and dynamical (bulk

  4. Radiative properties of optical board embedded with optical black holes

    International Nuclear Information System (INIS)

    Qiu, J.; Liu, L.H.; Hsu, P.-F.

    2011-01-01

    Unique radiative properties, such as wavelength-selective transmission or absorption, have been intensively studied. Historically, geometries for wavelength-selective of light absorption were developed based on metallic periodical structures, which were only applied in the case of TM wave incidence due to the excitation of surface plasmons. In this paper, we develop an alternative approach to selective wavelength of light absorption (both TE and TM waves), based on an optical board periodical embedded with optical black holes. Numerical work was carried out to study such structure's radiative properties within the wavelength range of 1-100 μm. The electromagnetic wave transmission through such a structure is predicted by solving Maxwell's equations using the finite-difference time-domain (FDTD) method. Spectral absorptance varies with the period of optical black holes. When the incidence wavelength is much larger than the inner core radius, most of the light energy will be transmitted through the inner core. Otherwise, the energy will be mainly absorbed. Numerical results of the radiative properties of the optical board with different incidence wavelengths are also obtained. The effect of the oblique incidence wave is investigated. This study helps us gain a better understanding of the radiative properties of an optical board embedded with optical black holes and develop an alternative approach to selective light absorption.

  5. Black holes in binary stars

    NARCIS (Netherlands)

    Wijers, R.A.M.J.

    1996-01-01

    Introduction Distinguishing neutron stars and black holes Optical companions and dynamical masses X-ray signatures of the nature of a compact object Structure and evolution of black-hole binaries High-mass black-hole binaries Low-mass black-hole binaries Low-mass black holes Formation of black holes

  6. Discovery and Monitoring of a New Black Hole Candidate XTE J1752-223 with RXTE: RMS Spectrum Evolution, BH Mass and the Source Distance

    Science.gov (United States)

    Shaposhinikov, Nikolai; Markwardt, Craig; Swank, Jean; Krimm, Hans

    2010-01-01

    We report on the discovery and monitoring observations of a new galactic black hole candidate XTE J1752-223 by Rossi X-ray Timing Explorer (RXTE). The new source appeared on the X-ray sky on October 21 2009 and was active for almost 8 months. Phenomenologically, the source exhibited the low-hard/highsoft spectral state bi-modality and the variability evolution during the state transition that matches standard behavior expected from a stellar mass black hole binary. We model the energy spectrum throughout the outburst using a generic Comptonization model assuming that part of the input soft radiation in the form of a black body spectrum gets reprocessed in the Comptonizing medium. We follow the evolution of fractional root-mean-square (RMS) variability in the RXTE/PCA energy band with the source spectral state and conclude that broad band variability is strongly correlated with the source hardness (or Comptonized fraction). We follow changes in the energy distribution of rms variability during the low-hard state and the state transition and find further evidence that variable emission is strongly concentrated in the power-law spectral component. We discuss the implication of our results to the Comptonization regimes during different spectral states. Correlations of spectral and variability properties provide measurements of the BH mass and distance to the source. The spectral-timing correlation scaling technique applied to the RXTE observations during the hardto- soft state transition indicates a mass of the BH in XTE J1752-223 between 8 and 11 solar masses and a distance to the source about 3.5 kiloparsec.

  7. The stable problem of the black-hole connected region in the Schwarzschild black hole

    OpenAIRE

    Tian, Guihua

    2005-01-01

    The stability of the Schwarzschild black hole is studied. Using the Painlev\\'{e} coordinate, our region can be defined as the black-hole-connected region(r>2m, see text) of the Schwarzschild black hole or the white-hole-connected region(r>2m, see text) of the Schwarzschild black hole. We study the stable problems of the black-hole-connected region. The conclusions are: (1) in the black-hole-connected region, the initially regular perturbation fields must have real frequency or complex frequen...

  8. Rotating black holes at future colliders. III. Determination of black hole evolution

    International Nuclear Information System (INIS)

    Ida, Daisuke; Oda, Kin-ya; Park, Seong Chan

    2006-01-01

    TeV scale gravity scenario predicts that the black hole production dominates over all other interactions above the scale and that the Large Hadron Collider will be a black hole factory. Such higher-dimensional black holes mainly decay into the standard model fields via the Hawking radiation whose spectrum can be computed from the greybody factor. Here we complete the series of our work by showing the greybody factors and the resultant spectra for the brane-localized spinor and vector field emissions for arbitrary frequencies. Combining these results with the previous works, we determine the complete radiation spectra and the subsequent time evolution of the black hole. We find that, for a typical event, well more than half a black hole mass is emitted when the hole is still highly rotating, confirming our previous claim that it is important to take into account the angular momentum of black holes

  9. Black holes. Chapter 6

    International Nuclear Information System (INIS)

    Penrose, R.

    1980-01-01

    Conditions for the formation of a black hole are considered, and the properties of black holes. The possibility of Cygnus X-1 as a black hole is discussed. Einstein's theory of general relativity in relation to the formation of black holes is discussed. (U.K.)

  10. Statistical black-hole thermodynamics

    International Nuclear Information System (INIS)

    Bekenstein, J.D.

    1975-01-01

    Traditional methods from statistical thermodynamics, with appropriate modifications, are used to study several problems in black-hole thermodynamics. Jaynes's maximum-uncertainty method for computing probabilities is used to show that the earlier-formulated generalized second law is respected in statistically averaged form in the process of spontaneous radiation by a Kerr black hole discovered by Hawking, and also in the case of a Schwarzschild hole immersed in a bath of black-body radiation, however cold. The generalized second law is used to motivate a maximum-entropy principle for determining the equilibrium probability distribution for a system containing a black hole. As an application we derive the distribution for the radiation in equilibrium with a Kerr hole (it is found to agree with what would be expected from Hawking's results) and the form of the associated distribution among Kerr black-hole solution states of definite mass. The same results are shown to follow from a statistical interpretation of the concept of black-hole entropy as the natural logarithm of the number of possible interior configurations that are compatible with the given exterior black-hole state. We also formulate a Jaynes-type maximum-uncertainty principle for black holes, and apply it to obtain the probability distribution among Kerr solution states for an isolated radiating Kerr hole

  11. Astronaut observations of global biomass burning

    International Nuclear Information System (INIS)

    Wood, C.A.; Nelson, R.

    1991-01-01

    One of the most fundamental inputs for understanding and modeling possible effects of biomass burning is knowledge of the size of the area burned. Because the burns are often very large and occur on all continents (except Antarctica), observations from space are essential. Information is presented in this chapter on another method for monitoring biomass burning, including immediate and long-term effects. Examples of astronaut photography of burning during one year give a perspective of the widespread occurrence of burning and the variety of biological materials that are consumed. The growth of burning in the Amazon region is presented over 15 years using smoke as a proxy for actual burning. Possible climate effects of smoke palls are also discussed

  12. Car radiator burns: a prevention issue.

    Science.gov (United States)

    Rabbitts, Angela; Alden, Nicole E; Conlin, Tara; Yurt, Roger W

    2004-01-01

    Scald burns continue to be the major cause of injury to patients admitted to the burn center. Scald burns occurring from car radiator fluid comprise a significant subgroup. Although manufacturer warning labels have been placed on car radiators, these burns continue to occur. This retrospective review looks at all patients admitted to our burn center who suffered scald burns from car radiator fluid to assess the extent of this problem. During the study period, 86 patients were identified as having suffered scald burns as a result of contact with car radiator fluid. Seventy-one percent of the burn injuries occurred in the summer months. The areas most commonly burned were the head and upper extremities. Burn prevention efforts have improved greatly over the years; however, this study demonstrates that scald burns from car radiator fluid continue to cause physical, emotional, and financial devastation. The current radiator warning labels alone are not effective. The National Highway Traffic Safety Administration has proposed a new federal motor vehicle safety standard to aid in decreasing the number of scald burns from car radiators. The results of this study were submitted to the United States Department of Transportation for inclusion in a docket for federal legislation supporting these safety measures.

  13. Black hole hair removal

    International Nuclear Information System (INIS)

    Banerjee, Nabamita; Mandal, Ipsita; Sen, Ashoke

    2009-01-01

    Macroscopic entropy of an extremal black hole is expected to be determined completely by its near horizon geometry. Thus two black holes with identical near horizon geometries should have identical macroscopic entropy, and the expected equality between macroscopic and microscopic entropies will then imply that they have identical degeneracies of microstates. An apparent counterexample is provided by the 4D-5D lift relating BMPV black hole to a four dimensional black hole. The two black holes have identical near horizon geometries but different microscopic spectrum. We suggest that this discrepancy can be accounted for by black hole hair - degrees of freedom living outside the horizon and contributing to the degeneracies. We identify these degrees of freedom for both the four and the five dimensional black holes and show that after their contributions are removed from the microscopic degeneracies of the respective systems, the result for the four and five dimensional black holes match exactly.

  14. Oral Rehydration Therapy in Burn Patients

    Science.gov (United States)

    2014-04-24

    Burn Any Degree Involving 20-29 Percent of Body Surface; Burn Any Degree Involving 30-39 Percent of Body Surface; Burn Any Degree Involving 40-49 Percent of Body Surface; Burn Any Degree Involving 50-59 Percent of Body Surface; Burn Any Degree Involving 60-65 Percent of Body Surface

  15. Scaling function, spectral function and nucleon momentum distribution in nuclei

    International Nuclear Information System (INIS)

    Antonov, A.N.; Ivanov, M.V.; Caballero, J.A.; Barbaro, M.B.; Udias, J.M.; Moya de Guerra, E.; Donnelly, T.W.

    2010-01-01

    The aim of the study is to find a good simultaneous description of the spectral function and the momentum distribution in relation to the realistic scaling function obtained from inclusive electron-nuclei scattering experiments. We start with a modified Hartree-Fock spectral function in which the energy dependent part (δ-function) is replaced by the Gaussian distributions with hole state widths as free parameters. We calculate the scaling function and the nucleon momentum distribution on the basis of the spectral function constructed in this way, trying to find a good description of the experimental data. The obtained scaling function has a weak asymmetry and the momentum distribution has not got a high-momentum tail in the case when harmonic-oscillator single-particle wave functions are used. So, to improve the behavior of the momentum distribution we used the basis of natural orbitals (NO) in which short-range correlations are partly incorporated. The results for the scaling function show again a weak asymmetry, but in this case the momentum distribution has a high-momentum tail. As a next step we include final-state interactions (FSI) in the calculations to reproduce the experimentally observed asymmetry of the scaling function. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Mahi R. [Department of Physics and Astronomy, University of Western Ontario, London N6A 3K7 (Canada); Najiminaini, Mohamadreza; Carson, Jeffrey J. L. [Lawson Health Research Institute, St. Joseph' s Health Care, 268 Grosvenor Street, London N6A 4V2 (Canada); Department of Medical Biophysics, University of Western Ontario, London N6A 3K7 (Canada); Balakrishnan, Shankar [Department of Physics and Astronomy, University of Western Ontario, London N6A 3K7 (Canada); Lawson Health Research Institute, St. Joseph' s Health Care, 268 Grosvenor Street, London N6A 4V2 (Canada); Department of Medical Biophysics, University of Western Ontario, London N6A 3K7 (Canada)

    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.

  17. Gain investigation of Perylene-Red-doped PMMA for stimulated luminescent solar concentrators.

    Science.gov (United States)

    Kaysir, Md Rejvi; Fleming, Simon; Argyros, Alexander

    2018-04-01

    Luminescent solar concentrators (LSCs) utilizing stimulated emission by a seed laser are a promising approach to overcome the limitations of conventional LSCs, with a significant reduction of the photovoltaic material. In our previous work, we demonstrated the principle of a stimulated LSC (s-LSC) and correspondingly developed a model for quantifying the output power of such a system, taking into account different important physical parameters. The model suggested Perylene Red (PR) dye as a potential candidate for s-LSCs. Here, we experimentally investigate the gain of PR-doped polymethyl methacrylate (PMMA) required for s-LSCs using a single pump wavelength (instead of the solar spectrum) as a proof of principle. The results found from the experiment are well matched with the previously developed numerical model except for gain saturation, which occurs at a comparatively small seed laser signal power. To investigate the gain saturation, two approaches were taken: investigating (i) spectral hole burning and (ii) triplet state absorption. Experimental investigation of spectral hole burning with PR dyes showed a small effect on the gain saturation. We developed a general state model considering triplet state absorption of the PR dyes for the second approach. The state model suggests that the PR dyes suffer from significant triplet state absorption loss, which obstructs the normal operation of the PR-based s-LSC system.

  18. Composition and Structure of Forest Fire Refugia: What Are the Ecosystem Legacies across Burned Landscapes?

    Directory of Open Access Journals (Sweden)

    Garrett W. Meigs

    2018-05-01

    Full Text Available Locations within forest fires that remain unburned or burn at low severity—known as fire refugia—are important components of contemporary burn mosaics, but their composition and structure at regional scales are poorly understood. Focusing on recent, large wildfires across the US Pacific Northwest (Oregon and Washington, our research objectives are to (1 classify fire refugia and burn severity based on relativized spectral change in Landsat time series; (2 quantify the pre-fire composition and structure of mapped fire refugia; (3 in forested areas, assess the relative abundance of fire refugia and other burn severity classes across forest composition and structure types. We analyzed a random sample of 99 recent fires in forest-dominated landscapes from 2004 to 2015 that collectively encompassed 612,629 ha. Across the region, fire refugia extent was substantial but variable from year to year, with an annual mean of 38% of fire extent and range of 15–60%. Overall, 85% of total fire extent was forested, with the other 15% being non-forest. In comparison, 31% of fire refugia extent was non-forest prior to the most recent fire, highlighting that mapped refugia do not necessarily contain tree-based ecosystem legacies. The most prevalent non-forest cover types in refugia were vegetated: shrub (40%, herbaceous (33%, and crops (18%. In forested areas, the relative abundance of fire refugia varied widely among pre-fire forest types (20–70% and structural conditions (23–55%. Consistent with fire regime theory, fire refugia and high burn severity areas were inversely proportional. Our findings underscore that researchers, managers, and other stakeholders should interpret burn severity maps through the lens of pre-fire land cover, especially given the increasing importance of fire and fire refugia under global change.

  19. Brane holes

    International Nuclear Information System (INIS)

    Frolov, Valeri P.; Mukohyama, Shinji

    2011-01-01

    The aim of this paper is to demonstrate that in models with large extra dimensions under special conditions one can extract information from the interior of 4D black holes. For this purpose we study an induced geometry on a test brane in the background of a higher-dimensional static black string or a black brane. We show that, at the intersection surface of the test brane and the bulk black string or brane, the induced metric has an event horizon, so that the test brane contains a black hole. We call it a brane hole. When the test brane moves with a constant velocity V with respect to the bulk black object, it also has a brane hole, but its gravitational radius r e is greater than the size of the bulk black string or brane r 0 by the factor (1-V 2 ) -1 . We show that bulk ''photon'' emitted in the region between r 0 and r e can meet the test brane again at a point outside r e . From the point of view of observers on the test brane, the events of emission and capture of the bulk photon are connected by a spacelike curve in the induced geometry. This shows an example in which extra dimensions can be used to extract information from the interior of a lower-dimensional black object. Instead of the bulk black string or brane, one can also consider a bulk geometry without a horizon. We show that nevertheless the induced geometry on the moving test brane can include a brane hole. In such a case the extra dimensions can be used to extract information from the complete region of the brane-hole interior. We discuss thermodynamic properties of brane holes and interesting questions which arise when such an extra-dimensional channel for the information mining exists.

  20. A mass of less than 15 solar masses for the black hole in an ultraluminous X-ray source.

    Science.gov (United States)

    Motch, C; Pakull, M W; Soria, R; Grisé, F; Pietrzyński, G

    2014-10-09

    Most ultraluminous X-ray sources have a typical set of properties not seen in Galactic stellar-mass black holes. They have luminosities of more than 3 × 10(39) ergs per second, unusually soft X-ray components (with a typical temperature of less than about 0.3 kiloelectronvolts) and a characteristic downturn in their spectra above about 5 kiloelectronvolts. Such puzzling properties have been interpreted either as evidence of intermediate-mass black holes or as emission from stellar-mass black holes accreting above their Eddington limit, analogous to some Galactic black holes at peak luminosity. Recently, a very soft X-ray spectrum was observed in a rare and transient stellar-mass black hole. Here we report that the X-ray source P13 in the galaxy NGC 7793 is in a binary system with a period of about 64 days and exhibits all three canonical properties of ultraluminous sources. By modelling the strong optical and ultraviolet modulations arising from X-ray heating of the B9Ia donor star, we constrain the black hole mass to be less than 15 solar masses. Our results demonstrate that in P13, soft thermal emission and spectral curvature are indeed signatures of supercritical accretion. By analogy, ultraluminous X-ray sources with similar X-ray spectra and luminosities of up to a few times 10(40) ergs per second can be explained by supercritical accretion onto massive stellar-mass black holes.

  1. Treatment of secondary burn wound progression in contact burns-a systematic review of experimental approaches.

    Science.gov (United States)

    Schmauss, Daniel; Rezaeian, Farid; Finck, Tom; Machens, Hans-Guenther; Wettstein, Reto; Harder, Yves

    2015-01-01

    After a burn injury, superficial partial-thickness burn wounds may progress to deep partial-thickness or full-thickness burn wounds, if kept untreated. This phenomenon is called secondary burn wound progression or conversion. Burn wound depth is an important determinant of patient morbidity and mortality. Therefore, reduction or even the prevention of secondary burn wound progression is one goal of the acute care of burned patients. The objective of this study was to review preclinical approaches evaluating therapies to reduce burn wound progression. A systematic review of experimental approaches in animals that aim at reducing or preventing secondary burn wound progression was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta Analysis (PRISMA) guidelines. The selected references consist of all the peer-reviewed studies performed in vivo in animals and review articles published in English, German, Italian, Spanish, or French language relevant to the topic of secondary burn wound progression. We searched MEDLINE, Cochrane Library, and Google Scholar including all the articles published from the beginning of notations to the present. The search was conducted between May 3, 2012 and December 26, 2013. We included 29 experimental studies in this review, investigating agents that maintain or increase local perfusion conditions, as well as agents that exhibit an anti-coagulatory, an anti-inflammatory, or an anti-apoptotic property. Warm water, simvastatin, EPO, or cerium nitrate may represent particularly promising approaches for the translation into clinical use in the near future. This review demonstrates promising experimental approaches that might reduce secondary burn wound progression. Nevertheless, a translation into clinical application needs to confirm the results compiled in experimental animal studies.

  2. Spectral properties of excitons in the bilayer graphene

    Science.gov (United States)

    Apinyan, V.; Kopeć, T. K.

    2018-01-01

    In this paper, we consider the spectral properties of the bilayer graphene with the local excitonic pairing interaction between the electrons and holes. We consider the generalized Hubbard model, which includes both intralayer and interlayer Coulomb interaction parameters. The solution of the excitonic gap parameter is used to calculate the electronic band structure, single-particle spectral functions, the hybridization gap, and the excitonic coherence length in the bilayer graphene. We show that the local interlayer Coulomb interaction is responsible for the semimetal-semiconductor transition in the double layer system, and we calculate the hybridization gap in the band structure above the critical interaction value. The formation of the excitonic band gap is reported as the threshold process and the momentum distribution functions have been calculated numerically. We show that in the weak coupling limit the system is governed by the Bardeen-Cooper-Schrieffer (BCS)-like pairing state. Contrary, in the strong coupling limit the excitonic condensate states appear in the semiconducting phase, by forming the Dirac's pockets in the reciprocal space.

  3. A Uniformly Selected Sample of Low-mass Black Holes in Seyfert 1 Galaxies. II. The SDSS DR7 Sample

    Science.gov (United States)

    Liu, He-Yang; Yuan, Weimin; Dong, Xiao-Bo; Zhou, Hongyan; Liu, Wen-Juan

    2018-04-01

    A new sample of 204 low-mass black holes (LMBHs) in active galactic nuclei (AGNs) is presented with black hole masses in the range of (1–20) × 105 M ⊙. The AGNs are selected through a systematic search among galaxies in the Seventh Data Release (DR7) of the Sloan Digital Sky Survey (SDSS), and careful analyses of their optical spectra and precise measurement of spectral parameters. Combining them with our previous sample selected from SDSS DR4 makes it the largest LMBH sample so far, totaling over 500 objects. Some of the statistical properties of the combined LMBH AGN sample are briefly discussed in the context of exploring the low-mass end of the AGN population. Their X-ray luminosities follow the extension of the previously known correlation with the [O III] luminosity. The effective optical-to-X-ray spectral indices α OX, albeit with a large scatter, are broadly consistent with the extension of the relation with the near-UV luminosity L 2500 Å. Interestingly, a correlation of α OX with black hole mass is also found, with α OX being statistically flatter (stronger X-ray relative to optical) for lower black hole masses. Only 26 objects, mostly radio loud, were detected in radio at 20 cm in the FIRST survey, giving a radio-loud fraction of 4%. The host galaxies of LMBHs have stellar masses in the range of 108.8–1012.4 M ⊙ and optical colors typical of Sbc spirals. They are dominated by young stellar populations that seem to have undergone continuous star formation history.

  4. In-situ burning: NIST studies

    International Nuclear Information System (INIS)

    Evans, D.D.

    1992-01-01

    In-situ burning of spilled oil has distinct advantages over other countermeasures. It offers the potential to convert rapidly large quantities of oil into its primary combustion products, carbon dioxide and water, with a small percentage of other unburned and residue byproducts. Because the oil is converted to gaseous products of combustion by burning, the need for physical collection, storage, and transport of recovered fluids is reduced to the few percent of the original spill volume that remains as residue after burning. Burning oil spills produces a visible smoke plume containing smoke particulate and other products of combustion which may persist for many kilometers from the burn. This fact gives rise to public health concerns, related to the chemical content of the smoke plume and the downwind deposition of particulate, which need to be answered. In 1985, a joint Minerals Management Service (MMS) and Environment Canada (EC) in-situ burning research program was begun at the National Institute of Standards and Technology (NIST). This research program was designed to study the burning of large crude oil spills on water and how this burning would affect air quality by quantifying the products of combustion and developing methods to predict the downwind smoke particulate deposition. To understand the important features of in-situ burning, it is necessary to perform both laboratory and mesoscale experiments. Finally, actual burns of spilled oil at sea will be necessary to evaluate the method at the anticipated scale of actual response operations. In this research program there is a continuing interaction between findings from measurements on small fire experiments performed in the controlled laboratory environments of NIST and the Fire Research Institute (FRI) in Japan, and large fire experiments at facilities like the USCG Fire Safety and Test Detachment in Mobile, Alabama where outdoor liquid fuel burns in large pans are possible

  5. Reliability enhancement through optimal burn-in

    Science.gov (United States)

    Kuo, W.

    1984-06-01

    A numerical reliability and cost model is defined for production line burn-in tests of electronic components. The necessity of burn-in is governed by upper and lower bounds: burn-in is mandatory for operation-critical or nonreparable component; no burn-in is needed when failure effects are insignificant or easily repairable. The model considers electronic systems in terms of a series of components connected by a single black box. The infant mortality rate is described with a Weibull distribution. Performance reaches a steady state after burn-in, and the cost of burn-in is a linear function for each component. A minimum cost is calculated among the costs and total time of burn-in, shop repair, and field repair, with attention given to possible losses in future sales from inadequate burn-in testing.

  6. Phoenix Society for Burn Survivors

    Science.gov (United States)

    ... in 2018! Learn More For Loved Ones A burn injury doesn't just impact the survivor. Families ... to support longterm recovery, improve the quality of burn care, and prevent burn injury. Explore articles on ...

  7. Black holes are warm

    International Nuclear Information System (INIS)

    Ravndal, F.

    1978-01-01

    Applying Einstein's theory of gravitation to black holes and their interactions with their surroundings leads to the conclusion that the sum of the surface areas of several black holes can never become less. This is shown to be analogous to entropy in thermodynamics, and the term entropy is also thus applied to black holes. Continuing, expressions are found for the temperature of a black hole and its luminosity. Thermal radiation is shown to lead to explosion of the black hole. Numerical examples are discussed involving the temperature, the mass, the luminosity and the lifetime of black mini-holes. It is pointed out that no explosions corresponding to the prediction have been observed. It is also shown that the principle of conservation of leptons and baryons is broken by hot black holes, but that this need not be a problem. The related concept of instantons is cited. It is thought that understanding of thermal radiation from black holes may be important for the development of a quantified gravitation theory. (JIW)

  8. Luminescence of high density electron-hole plasma in CdS and CdSe in a wide temperature range

    International Nuclear Information System (INIS)

    Yoshida, H.; Shionoya, S.

    1983-01-01

    Time-resolved spectra of the spontaneous luminescence of the high density electron-hole plasma (EHP) in CdS and CdSe are observed in a wide range of temperature which is surely higher than the calculated critical temperature for electron-hole liquid formation, in order to carry forward discussion on dynamic nature of the EHP previously observed in 4.2 K experiments. Spectra in the late stage are analyzed, and obtained values of the reduced bandgap energy and chemical potential are compared with those theoretically calculated for higher temperatures. The aspects of the change of the spectral shape in the late stage are hard to understand. Unfortunately no clear conclusion is drawn on the nature of the EHP produced at 4.2 K. The only thing one can say is that the condensed electron-hole liquid state, which is in equilibrium with the exciton state, is not realized. (author)

  9. Ultrasound assessed thickness of burn scars in association with laser Doppler imaging determined depth of burns in paediatric patients.

    Science.gov (United States)

    Wang, Xue-Qing; Mill, Julie; Kravchuk, Olena; Kimble, Roy M

    2010-12-01

    This study describes the ultrasound assessment of burn scars in paediatric patients and the association of these scar thickness with laser Doppler imaging (LDI) determined burn depth. A total of 60 ultrasound scar assessments were conducted on 33 scars from 21 paediatric burn patients at 3, 6 and 9 months after-burn. The mean of peak scar thickness was 0.39±0.032 cm, with the thickest at 6 months (0.40±0.036 cm). There were 17 scald burn scars (0.34±0.045 cm), 4 contact burn scars (0.61±0.092 cm), and 10 flame burn scars (0.42±0.058 cm). Each group of scars followed normal distributions. Twenty-three scars had original burns successfully scanned by LDI and various depths of burns were presented by different colours according to blood perfusion units (PU), with dark blue burns, with the thinnest scars for green coloured burns and the thickest for dark blue coloured burns. Within light blue burns, grafted burns healed with significantly thinner scars than non-grafted burns. This study indicates that LDI can be used for predicting the risk of hypertrophic scarring and for guiding burn care. To our knowledge, this is the first study to correlate the thickness of burns scars by ultrasound scan with burn depth determined by LDI. Copyright © 2010 Elsevier Ltd and ISBI. All rights reserved.

  10. The slightly-enriched spectral shift control reactor

    Energy Technology Data Exchange (ETDEWEB)

    Martin, W.R.; Lee, J.C.; Larsen, E.W. (Michigan Univ., Ann Arbor, MI (United States). Dept. of Nuclear Engineering); Edlund, M.C. (Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Mechanical and Nuclear Engineering)

    1991-11-01

    An advanced converter reactor design utilizing mechanical spectral shift control rods in a conventional pressurized water reactor configuration is under investigation. The design is based on the principle that a harder spectrum during the early part of the fuel cycle will result in large neutron captures in fertile {sup 238}U, which can then be burned in situ in a softer spectrum later in the cycle. Preliminary design calculations performed during FY 89 showed that the slightly-enriched spectral shift reactor design offers the benefit of substantially increased fuel resource utilization with the proven safety characteristics of the pressurized water reactor technology retained. Optimization of the fuel design and development of fuel management strategies were carried out in FY 90, along with effort to develop and validate neutronic methodology for tight-lattice configurations with hard spectra. During FY 91, the final year of the grant, the final Slightly-Enriched Spectral Shift Reactor (SESSR) design was determined, and reference design analyses were performed for the assemblies as well as the global core configuration, both at the beginning of cycle (BOC) and with depletion. The final SESSR design results in approximately a 20% increase in the utilization of uranium resources, based on equilibrium fuel cycle analyses. Acceptable pin power peaking is obtained with the final core design, with assembly peaking factors equal to less than 1.04 for spectral shift control rods both inserted and withdrawn, and global peaking factors at BOC predicted to be 1.4. In addition, a negative Moderation Temperature Coefficient (MTC) is maintained for BOC, which is difficult to achieve with conventional advanced converter designs based on a closed fuel cycle. The SESSR design avoids the need for burnable poison absorber, although they could be added if desired to increase the cycle length while maintaining a negative MTC.

  11. The slightly-enriched spectral shift control reactor

    International Nuclear Information System (INIS)

    Martin, W.R.; Lee, J.C.; Larsen, E.W.; Edlund, M.C.

    1991-11-01

    An advanced converter reactor design utilizing mechanical spectral shift control rods in a conventional pressurized water reactor configuration is under investigation. The design is based on the principle that a harder spectrum during the early part of the fuel cycle will result in large neutron captures in fertile 238 U, which can then be burned in situ in a softer spectrum later in the cycle. Preliminary design calculations performed during FY 89 showed that the slightly-enriched spectral shift reactor design offers the benefit of substantially increased fuel resource utilization with the proven safety characteristics of the pressurized water reactor technology retained. Optimization of the fuel design and development of fuel management strategies were carried out in FY 90, along with effort to develop and validate neutronic methodology for tight-lattice configurations with hard spectra. During FY 91, the final year of the grant, the final Slightly-Enriched Spectral Shift Reactor (SESSR) design was determined, and reference design analyses were performed for the assemblies as well as the global core configuration, both at the beginning of cycle (BOC) and with depletion. The final SESSR design results in approximately a 20% increase in the utilization of uranium resources, based on equilibrium fuel cycle analyses. Acceptable pin power peaking is obtained with the final core design, with assembly peaking factors equal to less than 1.04 for spectral shift control rods both inserted and withdrawn, and global peaking factors at BOC predicted to be 1.4. In addition, a negative Moderation Temperature Coefficient (MTC) is maintained for BOC, which is difficult to achieve with conventional advanced converter designs based on a closed fuel cycle. The SESSR design avoids the need for burnable poison absorber, although they could be added if desired to increase the cycle length while maintaining a negative MTC

  12. Hole history, rotary hole DC-3

    International Nuclear Information System (INIS)

    1977-10-01

    Purpose of hole DC-3 was to drill into the Umtanum basalt flow using both conventional rotary and core drilling methods. The borehole is to be utilized for geophysical logging, future hydrological testing, and the future installation of a borehole laboratory for long-term pressure, seismic, and moisture migration or accumulation recording in the Umtanum basalt flow in support of the Basalt Waste Isolation Program. Hole DC-3 is located east of the 200 West barricaded area on the Hanford reservation

  13. Aerosol optical properties during firework, biomass burning and dust episodes in Beijing

    Science.gov (United States)

    Yu, Xingna; Shi, Chanzhen; Ma, Jia; Zhu, Bin; Li, Mei; Wang, Jing; Yang, Suying; Kang, Na

    2013-12-01

    In order to characterize the aerosol optical properties during different pollution episodes that occurred in Beijing, the aerosol loading, scattering, and size distributions are presented using solar and sky radiance measurements from 2001 to 2010 in this paper. A much higher aerosol loading than the background level was observed during the pollution episodes. The average aerosol optical depth (AOD) is largest during dust episodes coupled with the lowest Ångström exponent (α), while higher AOD and lower α were more correlated with firework and biomass burning days. The total mean AOD at 440, 675, 870 and 1020 nm were 0.24, 0.49, 0.64 and 1.38 in the clean, firework display, biomass burning and dust days, respectively. The mean α for dust days was 0.51 and exceeded 1.1 for the remaining episodes. The size distribution of the dusty periods was dominated by the coarse mode, but the coarse mode was similar magnitude to the fine mode during the firework and biomass burning days. The volume concentration of the coarse mode during the dust days increased by a magnitude of more than 2-8 times that derived in the other three aerosol conditions, suggesting that dust is the major contributor of coarse mode particles in Beijing. The single scattering albedo (SSA) values also increased during the pollution episodes. The overall mean SSA at the four wavelengths were 0.865, 0.911, 0.922 and 0.931 in clean, firework display, biomass burning, and dust days in Beijing, respectively. However, in the blue spectral range, the dust aerosols exhibited pronounced absorption.

  14. Is location of burns related to outcome? A comparison between burns on extremities and burns on head and/or trunk in patients with low to intermediate TBSA in a burn center in The Netherlands.

    Science.gov (United States)

    Menger, Tirsa; Krijnen, Pieta; Tuinebreijer, Willem E; Breederveld, Roelf S

    2014-01-01

    In the literature no study was found about the effect of location of burns on outcome. The objective of this retrospective study was to investigate the effect of location on outcome parameters of 371 patients, admitted to our burn center from January 2009 to December 2011. The patients were included in the study if more than 80% of the burn(s) was localized either on the extremities or on the head and/or trunk. Two groups of TBSA were elaborated, low: 0 to 5% and intermediate: 5 to 15%. Two-hundred ninety-two patients (78.7%) had a low TBSA (burns on the head and/or trunk were more often admitted to the intensive care unit, mostly as a result of suspected inhalation injury (6.2 vs 0.9%; P = .008). More complications were seen in the intermediate TBSA group. In this study no difference in outcome was found between burns on the head and/or trunk or on extremities. The patients with burns on the head and/or trunk group are more frequently admitted to intensive care.

  15. X-RAY SPECTRAL VARIABILITY IN NGC 3783

    International Nuclear Information System (INIS)

    Reis, R. C.; Miller, J. M.; Fabian, A. C.; Walton, D. J.; Reynolds, C. S.; Trippe, M.; Mushotzky, R. F.; Brenneman, L. W.; Nowak, M. A.

    2012-01-01

    NGC 3783 was observed for approximately 210 ks by Suzaku and in this time showed significant spectral and flux variability at both short (20 ks) and long (100 ks) timescales. The full observation is found to consist of approximately six 'spectral periods' where the behavior of the soft (0.3-1.0 keV) and hard (2-10 keV) bands are somewhat distinct. Using a variety of methods we find that the strong warm absorber present in this source does not change on these timescales, confirming that the broadband variability is intrinsic to the central source. The time-resolved difference-spectra are well modeled with an absorbed power law below 10 keV, but show an additional hard excess at ≈20 keV in the latter stages of the observation. This suggests that, in addition to the variable power law, there is a further variable component that varies with time but not monotonically with flux. We show that a likely interpretation is that this further component is associated with variations in the reflection fraction or possibly ionization state of the accretion disk a few gravitational radii from the black hole.

  16. Exploring the Effects of Disk Thickness on the Black Hole Reflection Spectrum

    Science.gov (United States)

    Taylor, Corbin; Reynolds, Christopher S.

    2018-03-01

    The relativistically broadened reflection spectrum, observed in both AGN and X-ray binaries, has proven to be a powerful probe of the properties of black holes and the environments in which they reside. Emitted from the innermost regions of the accretion disk, this X-ray spectral component carries with it information not only about the plasma that resides in these extreme conditions, but also the black hole spin, a marker of the formation and accretion history of these objects. The models currently used to interpret the reflection spectrum are often simplistic, however, approximating the disk as an infinitely thin, optically thick plane of material orbiting in circular Keplerian orbits around the central object. Using a new relativistic ray-tracing suite (Fenrir) that allows for more complex disk approximations, we examine the effects that disk thickness may have on the reflection spectrum. Assuming a lamppost corona, we find that finite disk thickness can have a variety of effects on the reflection spectrum, including a truncation of the blue wing (from self-shadowing of the accretion disk) and an enhancement of the red wing (from the irradiation of the central “eye wall” of the inner disk). We deduce the systematic errors on black hole spin and height that may result from neglecting these effects.

  17. Burn Wise Educational Materials for Businesses

    Science.gov (United States)

    Burn Wise outreach material. Burn Wise is a partnership program of that emphasizes the importance of burning the right wood, the right way, in the right wood-burning appliance to protect your home, health, and the air we breathe.

  18. The treatment of extensively burned patents and β irradiational injury skin burn patients with irradiated pigskin

    International Nuclear Information System (INIS)

    Tang Zhongyi; Lu Xingan; Jing Ling; Qi Qiang

    1994-01-01

    Obvious therapeutic effects achieved by the covering of irradiation sterilized pigskin on burn wounds, escarectomized 3rd degree burn wounds β injured burns are discussed. The article also describes the manufacture processes of irradiated pigskins and the selection of surgical treatments of various burns. 5 refs., 1 tab., 4 figs

  19. Quantum aspects of black holes

    CERN Document Server

    2015-01-01

    Beginning with an overview of the theory of black holes by the editor, this book presents a collection of ten chapters by leading physicists dealing with the variety of quantum mechanical and quantum gravitational effects pertinent to black holes. The contributions address topics such as Hawking radiation, the thermodynamics of black holes, the information paradox and firewalls, Monsters, primordial black holes, self-gravitating Bose-Einstein condensates, the formation of small black holes in high energetic collisions of particles, minimal length effects in black holes and small black holes at the Large Hadron Collider. Viewed as a whole the collection provides stimulating reading for researchers and graduate students seeking a summary of the quantum features of black holes.

  20. Assault by burning in Jordan

    Science.gov (United States)

    Haddadin, W.

    2012-01-01

    Summary Criminal attacks by burns on women in Jordan are highlighted in this retrospective study carried out of all proved cases of criminal burns in female patients treated at the burn unit of the Royal Rehabilitation Center in Jordan between January 2005 and June 2012. Thirteen patients were included in our study, out of a total of 550 patients admitted, all in the age range of 16-45 yr. Of these 13 women, six were burned by acid throwing, five by hot water, and two by direct flames from fuel thrown over them. Burn percentage ranged from 15 to 75% of the total body surface area, with involvement in most cases of the face and upper trunk. The mean hospital stay was 33 days and the mortality rate was 3/13, i.e. 23%. Violence against women exists in Jordanian society, yet burning assaults are rare. Of these, burning by throwing acid is the most common and most disfiguring act, with a higher mortality rate in domestic environments. PMID:23766757

  1. Electron-phonon contribution to the phonon and excited electron (hole) linewidths in bulk Pd

    International Nuclear Information System (INIS)

    Sklyadneva, I Yu; Leonardo, A; Echenique, P M; Eremeev, S V; Chulkov, E V

    2006-01-01

    We present an ab initio study of the electron-phonon (e-ph) coupling and its contribution to the phonon linewidths and to the lifetime broadening of excited electron and hole states in bulk Pd. The calculations, based on density-functional theory, were carried out using a linear-response approach in the plane-wave pseudopotential representation. The obtained results for the Eliashberg spectral function α 2 F(ω), e-ph coupling constant λ, and the contribution to the lifetime broadening, Γ e-ph , show strong dependence on both the energy and momentum of an electron (hole) state. The calculation of phonon linewidths gives, in agreement with experimental observations, an anomalously large broadening for the transverse phonon mode T 1 in the Σ direction. In addition, this mode is found to contribute most strongly to the electron-phonon scattering processes on the Fermi surface

  2. The Northwest Infrared (NWIR) gas-phase spectral database of industrial and environmental chemicals: Recent updates

    Energy Technology Data Exchange (ETDEWEB)

    Brauer, Carolyn S.; Johnson, Timothy J.; Blake, Thomas A.; Sharpe, Steven W.; Sams, Robert L.; Tonkyn, Russell G.

    2014-05-22

    With continuing improvements in both standoff- and point-sensing techniques, there is an ongoing need for high-quality infrared spectral databases. The Northwest Infrared Database (NWIR) contains quantitative, gas-phase infrared spectra of nearly 500 pure chemical species that can be used for a variety of applications such as atmospheric monitoring, biomass burning studies, etc. The data, recorded at 0.1 cm-1 resolution, are pressure broadened to one atmosphere (N2) in order to mimic atmospheric conditions. Each spectrum is a composite composed of multiple individual measurements. Recent updates to the database include over 60 molecules that are known or suspected biomass-burning effluents. Examples from this set of measurements will be presented and experimental details will be discussed in the context of the utility of NWIR for environmental applications.

  3. Silicon Burning. II. Quasi-Equilibrium and Explosive Burning

    International Nuclear Information System (INIS)

    Hix, W.R.; Thielemann, F.

    1999-01-01

    Having examined the application of quasi-equilibrium to hydrostatic silicon burning in Paper I of this series, we now turn our attention to explosive silicon burning. Previous authors have shown that for material that is heated to high temperature by a passing shock and then cooled by adiabatic expansion, the results can be divided into three broad categories, incomplete burning, normal freezeout, and α-rich freezeout, with the outcome depending on the temperature, density, and cooling timescale. In all three cases, we find that the important abundances obey quasi-equilibrium for temperatures greater than approximately 3x10 9 K, with relatively little nucleosynthesis occurring following the breakdown of quasi-equilibrium. We will show that quasi-equilibrium provides better abundance estimates than global nuclear statistical equilibrium, even for normal freezeout, and particularly for α-rich freezeout. We will also examine the accuracy with which the final nuclear abundances can be estimated from quasi-equilibrium. copyright copyright 1999. The American Astronomical Society

  4. Black holes and beyond

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-02-01

    Belief in the existence of black holes is the ultimate act of faith for a physicist. First suggested by the English clergyman John Michell in the year 1784, the gravitational pull of a black hole is so strong that nothing - not even light - can escape. Gravity might be the weakest of the fundamental forces but black-hole physics is not for the faint-hearted. Black holes present obvious problems for would-be observers because they cannot, by definition, be seen with conventional telescopes - although before the end of the decade gravitational-wave detectors should be able to study collisions between black holes. Until then astronomers can only infer the existence of a black hole from its gravitational influence on other matter, or from the X-rays emitted by gas and dust as they are dragged into the black hole. However, once this material passes through the 'event horizon' that surrounds the black hole, we will never see it again - not even with X-ray specs. Despite these observational problems, most physicists and astronomers believe that black holes do exist. Small black holes a few kilometres across are thought to form when stars weighing more than about two solar masses collapse under the weight of their own gravity, while supermassive black holes weighing millions of solar masses appear to be present at the centre of most galaxies. Moreover, some brave physicists have proposed ways to make black holes - or at least event horizons - in the laboratory. The basic idea behind these 'artificial black holes' is not to compress a large amount of mass into a small volume, but to reduce the speed of light in a moving medium to less than the speed of the medium and so create an event horizon. The parallels with real black holes are not exact but the experiments could shed new light on a variety of phenomena. The first challenge, however, is to get money for the research. One year on from a high-profile meeting on artificial black holes in London, for

  5. Methylated spirit burns: an ongoing problem.

    Science.gov (United States)

    Jansbeken, J R H; Vloemans, A F P M; Tempelman, F R H; Breederveld, R S

    2012-09-01

    Despite many educational campaigns we still see burns caused by methylated spirit every year. We undertook a retrospective study to analyse the impact of this problem. We retrospectively collected data of all patients with burns caused by methylated spirit over twelve years from 1996 to 2008. Our main endpoints were: incidence, age, mechanism of injury, total body surface area (TBSA) burned, burn depth, need for surgery and length of hospital stay. Ninety-seven patients with methylated spirit burns were included. During the study period there was no decrease in the number of patients annually admitted to the burn unit with methylated spirit burns. 28% of the patients (n=27) were younger than eighteen years old, 15% (n=15) were ten years old or younger. The most common cause of burns was carelessness in activities involving barbecues, campfires and fondues. Mean TBSA burned was 16% (SD 12.4). 70% (n=68) had full thickness burns. 66% (n=64) needed grafting. Mean length of hospital stay was 23 days (SD 24.7). The use of methylated spirit is an ongoing problem, which continues to cause severe burns in adults and children. Therefore methylated spirit should be banned in households. We suggest sale only in specialised shops, clear labelling and mandatory warnings. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

  6. Burns (For Parents)

    Science.gov (United States)

    ... small, and have sensitive skin that needs extra protection. Although some minor burns aren't cause for concern and can ... burns, the mildest of the three, are limited to the top layer of skin: Signs ... pain, and minor swelling. The skin is dry without blisters. Healing ...

  7. Giant black hole rips star apart

    Science.gov (United States)

    2004-02-01

    amount is consistent with predictions that the momentum and energy of the accretion process will cause most of the destroyed star's gas to be flung away from the black hole. The force that disrupted the star in RXJ1242-11 is an extreme example of the tidal force caused by differences in gravity acting on the front and back of an object. The tidal force from the Moon causes tides in the oceans on Earth, and tidal force from Jupiter pulled Comet Shoemaker-Levy apart before it plunged into the giant planet. The odds that stellar tidal disruption will happen in a typical galaxy are long, about one in ten thousand. If it happened at the centre of the Milky Way, the resulting X-ray source would be about 50 000 times more powerful than the strongest X-ray source in our galaxy. However, such an event would not pose a threat to Earth because of the intervening distance of 25 000 light years. Other dramatic flares have been seen from galaxies, but this is the first to have been studied with the high spectral resolution of XMM-Newton and the high spatial resolution of Chandra. Both instruments have made a critical advance. Chandra showed that the RXJ1242-11 event occurred in the centre of a galaxy, where the black hole lurks. The XMM-Newton spectrum revealed the fingerprints expected for the surroundings of a black hole, and allowed other possible astronomical explanations to be ruled out. Evidence already exists for super-massive black holes in many galaxies, but looking for tidal disruptions represents a completely independent way to search for black holes. Observations like these are urgently needed to determine how quickly black holes can grow by swallowing neighbouring stars. Notes to editors This discovery was announced today at a press conference at NASA Headquarters in Washington DC, USA. A paper describing these results, by Stefanie Komossa and others, will be published in The Astrophysical Journal. ESA’s XMM-Newton can detect more X-ray sources than any previous

  8. Smartphone applications in burns.

    Science.gov (United States)

    Wurzer, Paul; Parvizi, Daryousch; Lumenta, David B; Giretzlehner, Michael; Branski, Ludwik K; Finnerty, Celeste C; Herndon, David N; Tuca, Alexandru; Rappl, Thomas; Smolle, Christian; Kamolz, Lars P

    2015-08-01

    Since the introduction of applications (apps) for smartphones, the popularity of medical apps has been rising. The aim of this review was to demonstrate the current availability of apps related to burns on Google's Android and Apple's iOS store as well as to include a review of their developers, features, and costs. A systematic online review of Google Play Store and Apple's App Store was performed by using the following search terms: "burn," "burns," "thermal," and the German word "Verbrennung." All apps that were programmed for use as medical apps for burns were included. The review was performed from 25 February until 1 March 2014. A closer look at the free and paid calculation apps including a standardized patient was performed. Four types of apps were identified: calculators, information apps, book/journal apps, and games. In Google Play Store, 31 apps were related to burns, of which 20 were calculation apps (eight for estimating the total body surface area (TBSA) and nine for total fluid requirement (TFR)). In Apple's App Store, under the category of medicine, 39 apps were related to burns, of which 21 were calculation apps (19 for estimating the TBSA and 17 for calculating the TFR). In 19 out of 32 available calculation apps, our study showed a correlation of the calculated TFR compared to our standardized patient. The review demonstrated that many apps for medical burns are available in both common app stores. Even free available calculation apps may provide a more objective and reproducible procedure compared to manual/subjective estimations, although there is still a lack of data security especially in personal data entered in calculation apps. Further clinical studies including smartphone apps for burns should be performed. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

  9. Towards more efficient burn care: Identifying factors associated with good quality of life post-burn.

    Science.gov (United States)

    Finlay, V; Phillips, M; Allison, G T; Wood, F M; Ching, D; Wicaksono, D; Plowman, S; Hendrie, D; Edgar, D W

    2015-11-01

    As minor burn patients constitute the vast majority of a developed nation case-mix, streamlining care for this group can promote efficiency from a service-wide perspective. This study tested the hypothesis that a predictive nomogram model that estimates likelihood of good long-term quality of life (QoL) post-burn is a valid way to optimise patient selection and risk management when applying a streamlined model of care. A sample of 224 burn patients managed by the Burn Service of Western Australia who provided both short and long-term outcomes was used to estimate the probability of achieving a good QoL defined as 150 out of a possible 160 points on the Burn Specific Health Scale-Brief (BSHS-B) at least six months from injury. A multivariate logistic regression analysis produced a predictive model provisioned as a nomogram for clinical application. A second, independent cohort of consecutive patients (n=106) was used to validate the predictive merit of the nomogram. Male gender (p=0.02), conservative management (p=0.03), upper limb burn (p=0.04) and high BSHS-B score within one month of burn (pburns were excluded due to loss to follow up. For clinicians managing comparable burn populations, the BSWA burns nomogram is an effective tool to assist the selection of patients to a streamlined care pathway with the aim of improving efficiency of service delivery. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

  10. Investigation of Spiral and Sweeping Holes

    Science.gov (United States)

    Thurman, Douglas; Poinsatte, Philip; Ameri, Ali; Culley, Dennis; Raghu, Surya; Shyam, Vikram

    2015-01-01

    Surface infrared thermography, hotwire anemometry, and thermocouple surveys were performed on two new film cooling hole geometries: spiral/rifled holes and fluidic sweeping holes. The spiral holes attempt to induce large-scale vorticity to the film cooling jet as it exits the hole to prevent the formation of the kidney shaped vortices commonly associated with film cooling jets. The fluidic sweeping hole uses a passive in-hole geometry to induce jet sweeping at frequencies that scale with blowing ratios. The spiral hole performance is compared to that of round holes with and without compound angles. The fluidic hole is of the diffusion class of holes and is therefore compared to a 777 hole and Square holes. A patent-pending spiral hole design showed the highest potential of the non-diffusion type hole configurations. Velocity contours and flow temperature were acquired at discreet cross-sections of the downstream flow field. The passive fluidic sweeping hole shows the most uniform cooling distribution but suffers from low span-averaged effectiveness levels due to enhanced mixing. The data was taken at a Reynolds number of 11,000 based on hole diameter and freestream velocity. Infrared thermography was taken for blowing rations of 1.0, 1.5, 2.0, and 2.5 at a density ration of 1.05. The flow inside the fluidic sweeping hole was studied using 3D unsteady RANS.

  11. Outcome after burns: an observational study on burn scar maturation and predictors for severe scarring.

    Science.gov (United States)

    van der Wal, Martijn B A; Vloemans, Jos F P M; Tuinebreijer, Wim E; van de Ven, Peter; van Unen, Ella; van Zuijlen, Paul P M; Middelkoop, Esther

    2012-01-01

    Long-term outcome of burn scars as well as the relation with clinically relevant parameters has not been studied quantitatively. Therefore, we conducted a detailed analysis on the clinical changes of burn scars in a longitudinal setup. In addition, we focused on the differences in scar quality in relation to the depth, etiology of the burn wound and age of the patient. Burn scars of 474 patients were subjected to a scar assessment protocol 3, 6, and 12 months postburn. Three different age groups were defined (≤5, 5-18, and ≥18 years). The observer part of the patient and observer scar assessment scale revealed a significant (p burned (p  0.230) have no significant influence on scar quality when corrected for sex, total body surface area burned, time, and age or etiology, respectively. © 2012 by the Wound Healing Society.

  12. Lawn mower-related burns.

    Science.gov (United States)

    Still, J; Orlet, H; Law, E; Gertler, C

    2000-01-01

    Lawn mower-related injuries are fairly common and are usually caused by the mower blades. Burns may also be associated with the use of power lawn mowers. We describe 27 lawn mower-related burn injuries of 24 male patients and 3 female patients. Three of the patients with burn injuries were children. Burn sizes ranged from 1% to 99% of the total body surface area (mean, 18.1%). Two of the patients died. The hospital stay ranged from 1 day to 45 days. Twenty-six injuries involved gasoline, which is frequently associated with refueling accidents. Safety measures should involve keeping children away from lawn mowers that are being used. The proper use and storage of gasoline is stressed.

  13. Black Hole Area Quantization rule from Black Hole Mass Fluctuations

    OpenAIRE

    Schiffer, Marcelo

    2016-01-01

    We calculate the black hole mass distribution function that follows from the random emission of quanta by Hawking radiation and with this function we calculate the black hole mass fluctuation. From a complete different perspective we regard the black hole as quantum mechanical system with a quantized event horizon area and transition probabilities among the various energy levels and then calculate the mass dispersion. It turns out that there is a perfect agreement between the statistical and ...

  14. Animal Models in Burn Research

    Science.gov (United States)

    Abdullahi, A.; Amini-Nik, S.; Jeschke, M.G

    2014-01-01

    Burn injury is a severe form of trauma affecting more than two million people in North America each year. Burn trauma is not a single pathophysiological event but a devastating injury that causes structural and functional deficits in numerous organ systems. Due to its complexity and the involvement of multiple organs, in vitro experiments cannot capture this complexity nor address the pathophysiology. In the past two decades, a number of burn animal models have been developed to replicate the various aspects of burn injury; to elucidate the pathophysiology and explore potential treatment interventions. Understanding the advantages and limitations of these animal models is essential for the design and development of treatments that are clinically relevant to humans. This review paper aims to highlight the common animal models of burn injury in order to provide investigators with a better understanding of the benefits and limitations of these models for translational applications. While many animal models of burn exist, we limit our discussion to the skin healing of mouse, rat, and pig. Additionally, we briefly explain hypermetabolic characteristics of burn injury and the animal model utilized to study this phenomena. Finally, we discuss the economic costs associated with each of these models in order to guide decisions of choosing the appropriate animal model for burn research. PMID:24714880

  15. Knowledge of childhood burn risks and burn first aid: Cool Runnings.

    Science.gov (United States)

    Burgess, Jacqueline D; Watt, Kerrianne A; Kimble, Roy M; Cameron, Cate M

    2018-01-31

    The high incidence of hot beverage scalds among young children has not changed in the past 15 years, but preventive campaigns have been scarce. A novel approach was used to engage mothers of young children in an app-based hot beverage scald prevention campaign 'Cool Runnings'. This paper provides baseline data for this randomised controlled trial (RCT). Queensland-based mothers aged 18+ years with at least one child aged 5-12 months were recruited via social media to Cool Runnings, which is a two-group, parallel, single-blinded RCT. In total, 498 participants from across Queensland completed the baseline questionnaire. The most common source of burn first aid information was the internet (79%). One-third (33%) correctly identified hot beverage scalds as the leading cause of childhood burns, 43% knew the age group most at risk. While 94% reported they would cool a burn with water, only 10% reported the recommended 20min duration. After adjusting for all relevant variables, there were two independent predictors of adequate burn first aid knowledge: first aid training in the past year (OR=3.32; 95% CI 1.8 to 6.1) and smoking status (OR=0.17; 95% CI 0.04 to 0.7). In this study, mothers of young children were largely unaware how frequently hot beverage scalds occur and the age group most susceptible to them. Inadequate burn first aid knowledge is prevalent across mothers of young children; there is an urgent and compelling need to improve burn first aid knowledge in this group. Given the high incidence of hot beverages scalds in children aged 6-24 months, it is important to target future burn prevention/first aid campaigns at parents of young children. ACTRN12616000019404; Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  16. Burn-out

    OpenAIRE

    Patricia van Echtelt

    2014-01-01

    Deze publicatie is alleen elektronisch verkrijgbaar (downloaden van deze site) Burn-out (ofwel: emotionele uitputting) komt relatief vaak voor: ongeveer één op de acht werknemers in Nederland heeft er last van. Het wordt dan ook gezien als een serieus maatschappelijk probleem dat beleidsmatig aandacht vergt. Dit rapport presenteert de resultaten van twee specifieke analyses over burn-out. Ten eerste gaan we na wat het effect is van emotionele uitputting op de loopbaan van werknemers. Ten twee...

  17. Monopole Black Hole Skyrmions

    OpenAIRE

    Moss, Ian G; Shiiki, N; Winstanley, E

    2000-01-01

    Charged black hole solutions with pion hair are discussed. These can be\\ud used to study monopole black hole catalysis of proton decay.\\ud There also exist\\ud multi-black hole skyrmion solutions with BPS monopole behaviour.

  18. Spectral properties near the Mott transition in the two-dimensional Hubbard model

    Science.gov (United States)

    Kohno, Masanori

    2013-03-01

    Single-particle excitations near the Mott transition in the two-dimensional (2D) Hubbard model are investigated by using cluster perturbation theory. The Mott transition is characterized by the loss of the spectral weight from the dispersing mode that leads continuously to the spin-wave excitation of the Mott insulator. The origins of the dominant modes of the 2D Hubbard model near the Mott transition can be traced back to those of the one-dimensional Hubbard model. Various anomalous spectral features observed in cuprate high-temperature superconductors, such as the pseudogap, Fermi arc, flat band, doping-induced states, hole pockets, and spinon-like and holon-like branches, as well as giant kink and waterfall in the dispersion relation, are explained in a unified manner as properties near the Mott transition in a 2D system.

  19. Outpatient presentations to burn centers: data from the Burns Registry of Australia and New Zealand outpatient pilot project.

    Science.gov (United States)

    Gabbe, Belinda J; Watterson, Dina M; Singer, Yvonne; Darton, Anne

    2015-05-01

    Most studies about burn injury focus on admitted cases. To compare outpatient and inpatient presentations at burn centers in Australia to inform the establishment of a repository for outpatient burn injury. Data for sequential outpatient presentations were collected at seven burn centers in Australia between December 2010 and May 2011 and compared with inpatient admissions from these centers recorded by the Burns Registry of Australia and New Zealand for the corresponding period. There were 788 outpatient and 360 inpatient presentations. Pediatric outpatients included more children burns (39% vs 24%). Adult outpatients included fewer males (58% vs 73%) and intentional injuries (3.3% vs 10%), and more scald (46% vs 30%) and contact burns (24% vs 13%). All pediatric, and 98% of adult, outpatient presentations involved a %TBSAburns presenting to burn centers differed to inpatient admission data, particularly with respect to etiology and burn severity, highlighting the importance of the need for outpatient data to enhance burn injury surveillance and inform prevention. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

  20. High burn rate solid composite propellants

    Science.gov (United States)

    Manship, Timothy D.

    High burn rate propellants help maintain high levels of thrust without requiring complex, high surface area grain geometries. Utilizing high burn rate propellants allows for simplified grain geometries that not only make production of the grains easier, but the simplified grains tend to have better mechanical strength, which is important in missiles undergoing high-g accelerations. Additionally, high burn rate propellants allow for a higher volumetric loading which reduces the overall missile's size and weight. The purpose of this study is to present methods of achieving a high burn rate propellant and to develop a composite propellant formulation that burns at 1.5 inches per second at 1000 psia. In this study, several means of achieving a high burn rate propellant were presented. In addition, several candidate approaches were evaluated using the Kepner-Tregoe method with hydroxyl terminated polybutadiene (HTPB)-based propellants using burn rate modifiers and dicyclopentadiene (DCPD)-based propellants being selected for further evaluation. Propellants with varying levels of nano-aluminum, nano-iron oxide, FeBTA, and overall solids loading were produced using the HTPB binder and evaluated in order to determine the effect the various ingredients have on the burn rate and to find a formulation that provides the burn rate desired. Experiments were conducted to compare the burn rates of propellants using the binders HTPB and DCPD. The DCPD formulation matched that of the baseline HTPB mix. Finally, GAP-plasticized DCPD gumstock dogbones were attempted to be made for mechanical evaluation. Results from the study show that nano-additives have a substantial effect on propellant burn rate with nano-iron oxide having the largest influence. Of the formulations tested, the highest burn rate was a 84% solids loading mix using nano-aluminum nano-iron oxide, and ammonium perchlorate in a 3:1(20 micron: 200 micron) ratio which achieved a burn rate of 1.2 inches per second at 1000

  1. Skyrmion black hole hair: Conservation of baryon number by black holes and observable manifestations

    Energy Technology Data Exchange (ETDEWEB)

    Dvali, Gia [Arnold Sommerfeld Center, Ludwig-Maximilians-Universität, 80333 München (Germany); Max-Planck-Institut für Physik, Werner-Heisenberg-Institut, 80805 München (Germany); Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Gußmann, Alexander, E-mail: alexander.gussmann@physik.uni-muenchen.de [Arnold Sommerfeld Center, Ludwig-Maximilians-Universität, 80333 München (Germany)

    2016-12-15

    We show that the existence of black holes with classical skyrmion hair invalidates standard proofs that global charges, such as the baryon number, cannot be conserved by a black hole. By carefully analyzing the standard arguments based on a Gedankenexperiment in which a black hole is seemingly-unable to return the baryon number that it swallowed, we identify inconsistencies in this reasoning, which does not take into the account neither the existence of skyrmion black holes nor the baryon/skyrmion correspondence. We then perform a refined Gedankenexperiment by incorporating the new knowledge and show that no contradiction with conservation of baryon number takes place at any stage of black hole evolution. Our analysis also indicates no conflict between semi-classical black holes and the existence of baryonic gauge interaction arbitrarily-weaker than gravity. Next, we study classical cross sections of a minimally-coupled massless probe scalar field scattered by a skyrmion black hole. We investigate how the skyrmion hair manifests itself by comparing this cross section with the analogous cross section caused by a Schwarzschild black hole which has the same ADM mass as the skyrmion black hole. Here we find an order-one difference in the positions of the characteristic peaks in the cross sections. The peaks are shifted to smaller scattering angles when the skyrmion hair is present. This comes from the fact that the skyrmion hair changes the near horizon geometry of the black hole when compared to a Schwarzschild black hole with same ADM mass. We keep the study of this second aspect general so that the qualitative results which we obtain can also be applied to black holes with classical hair of different kind.

  2. Entropy of quasiblack holes

    International Nuclear Information System (INIS)

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

    2010-01-01

    We trace the origin of the black hole entropy S, replacing a black hole by a quasiblack hole. Let the boundary of a static body approach its own gravitational radius, in such a way that a quasihorizon forms. We show that if the body is thermal with the temperature taking the Hawking value at the quasihorizon limit, it follows, in the nonextremal case, from the first law of thermodynamics that the entropy approaches the Bekenstein-Hawking value S=A/4. In this setup, the key role is played by the surface stresses on the quasihorizon and one finds that the entropy comes from the quasihorizon surface. Any distribution of matter inside the surface leads to the same universal value for the entropy in the quasihorizon limit. This can be of some help in the understanding of black hole entropy. Other similarities between black holes and quasiblack holes such as the mass formulas for both objects had been found previously. We also discuss the entropy for extremal quasiblack holes, a more subtle issue.

  3. Community integration after burn injuries.

    Science.gov (United States)

    Esselman, P C; Ptacek, J T; Kowalske, K; Cromes, G F; deLateur, B J; Engrav, L H

    2001-01-01

    Evaluation of community integration is a meaningful outcome criterion after major burn injury. The Community Integration Questionnaire (CIQ) was administered to 463 individuals with major burn injuries. The CIQ results in Total, Home Integration, Social Integration, and Productivity scores. The purposes of this study were to determine change in CIQ scores over time and what burn injury and demographic factors predict CIQ scores. The CIQ scores did not change significantly from 6 to 12 to 24 months postburn injury. Home integration scores were best predicted by sex and living situation; Social Integration scores by marital status; and Productivity scores by functional outcome, burn severity, age, and preburn work factors. The data demonstrate that individuals with burn injuries have significant difficulties with community integration due to burn and nonburn related factors. CIQ scores did not improve over time but improvement may have occurred before the initial 6-month postburn injury follow-up in this study.

  4. Is there a threshold age and burn size associated with poor outcomes in the elderly after burn injury?

    Science.gov (United States)

    Jeschke, Marc G; Pinto, Ruxandra; Costford, Sheila R.; Amini-Nik, Saeid

    2016-01-01

    Elderly burn care represents a vast challenge. The elderly are one of the most susceptible populations to burn injuries, but also one of the fastest growing demographics, indicating a substantial increase in patient numbers in the near future. Despite the need and importance of elderly burn care, survival of elderly burn patients is poor. Additionally, little is known about the responses of elderly patients after burn. One central question that has not been answered is what age defines an elderly patient. The current study was conducted to determine whether there is a cut-off age for elderly burn patients that is correlated with an increased risk for mortality and to determine the burn size in modern burn care that is associated with increased mortality. To answer these questions, we applied appropriate statistical analyses to the Ross Tilley Burn Centre and the Inflammatory and Host Response to Injury databases. We could not find a clear cut-off age that differentiates or predicts between survival and death. Risk of death increased linearly with increasing age. Additionally, we found that the LD50 decreases from 45% total body surface area (TBSA) to 25% TBSA from the age of 55 years to the age of 70 years, indicating that even small burns lead to poor outcome in the elderly. We therefore concluded that age is not an ideal to predictor of burn outcome, but we strongly suggest that burn care providers be aware that if an elderly patient sustains even a 25% TBSA burn, the risk of mortality is 50% despite the implementation of modern protocolized burn care. PMID:26803373

  5. Black holes without firewalls

    Science.gov (United States)

    Larjo, Klaus; Lowe, David A.; Thorlacius, Larus

    2013-05-01

    The postulates of black hole complementarity do not imply a firewall for infalling observers at a black hole horizon. The dynamics of the stretched horizon, that scrambles and reemits information, determines whether infalling observers experience anything out of the ordinary when entering a large black hole. In particular, there is no firewall if the stretched horizon degrees of freedom retain information for a time of the order of the black hole scrambling time.

  6. Crude oil burning mechanisms

    DEFF Research Database (Denmark)

    van Gelderen, Laurens; Malmquist, L.M.V.; Jomaas, Grunde

    2015-01-01

    In order to improve predictions for the burning efficiency and the residue composition of in-situ burning of crude oil, the burning mechanism of crude oil was studied in relation to the composition of its hydrocarbon mixture, before, during and after the burning. The surface temperature, flame...... height, mass loss rate and residues of three hydrocarbon liquids (n-octane, dodecane and hexadecane), two crude oils (DUC and REBCO) and one hydrocarbon liquid mixture of the aforementioned hydrocarbon liquids were studied using the Crude Oil Flammability Apparatus. The experimental results were compared...... on the highest achievable oil slick temperature. Based on this mechanism, predictions can then be made depending on the hydrocarbon composition of the fuel and the measured surface temperature....

  7. [Influence of three-level collaboration network of pediatric burns treatment in Anhui province on treatment effects of burn children].

    Science.gov (United States)

    Xia, Z G; Zhou, X L; Kong, W C; Li, X Z; Song, J H; Fang, L S; Hu, D L; Cai, C; Tang, Y Z; Yu, Y X; Wang, C H; Xu, Q L

    2018-03-20

    Objective: To explore the influence of three-level collaboration network of pediatric burns in Anhui province on treatment effects of burn children. Methods: The data of medical records of pediatric burn children transferred from Lu'an People's Hospital and Fuyang People's Hospital to the First Affiliated Hospital of Anhui Medical University from January 2014 to December 2015 and January 2016 to September 2017 (before and after establishing three-level collaboration network of pediatric burns treatment) were analyzed: percentage of transferred burn children to hospitalized burn children in corresponding period, gender, age, burn degree, treatment method, treatment result, occurrence and treatment result of shock, and operative and non-operative treatment time and cost. Rehabilitation result of burn children transferred back to local hospitals in 2016 and 2017. Data were processed with t test, chi-square test, Mann-Whitney U test, and Fisher's exact test. Results: (1) Percentage of burn children transferred from January 2014 to December 2015 was 34.3% (291/848) of the total number of hospitalized burn children in the same period of time, which was close to 30.4% (210/691) of burn children transferred from January 2016 to September 2017 ( χ (2)=2.672, P >0.05). (2) Gender, age, burn degree, and treatment method of burn children transferred from the two periods of time were close ( χ (2)=3.382, Z =-1.917, -1.911, χ (2)=3.133, P >0.05). (3) Cure rates of children with mild, moderate, and severe burns transferred from January 2016 to September 2017 were significantly higher than those of burn children transferred from January 2014 to December 2015 ( χ (2)=11.777, 6.948, 4.310, P burns transferred from the two periods of time were close ( χ (2)=1.181, P >0.05). (4) Children with mild and moderate burns transferred from the two periods of time were with no shock. The incidence of shock of children with severe burns transferred from January 2014 to December 2015 was 6

  8. Over spinning a black hole?

    Energy Technology Data Exchange (ETDEWEB)

    Bouhmadi-Lopez, Mariam; Cardoso, Vitor; Nerozzi, Andrea; Rocha, Jorge V, E-mail: mariam.bouhmadi@ist.utl.pt, E-mail: vitor.cardoso@ist.utl.pt, E-mail: andrea.nerozzi@ist.utl.pt, E-mail: jorge.v.rocha@ist.utl.pt [CENTRA, Department de Fisica, Instituto Superior Tecnico, Av. Rovisco Pais 1, 1049 Lisboa (Portugal)

    2011-09-22

    A possible process to destroy a black hole consists on throwing point particles with sufficiently large angular momentum into the black hole. In the case of Kerr black holes, it was shown by Wald that particles with dangerously large angular momentum are simply not captured by the hole, and thus the event horizon is not destroyed. Here we reconsider this gedanken experiment for black holes in higher dimensions. We show that this particular way of destroying a black hole does not succeed and that Cosmic Censorship is preserved.

  9. Spectral gamuts and spectral gamut mapping

    Science.gov (United States)

    Rosen, Mitchell R.; Derhak, Maxim W.

    2006-01-01

    All imaging devices have two gamuts: the stimulus gamut and the response gamut. The response gamut of a print engine is typically described in CIE colorimetry units, a system derived to quantify human color response. More fundamental than colorimetric gamuts are spectral gamuts, based on radiance, reflectance or transmittance units. Spectral gamuts depend on the physics of light or on how materials interact with light and do not involve the human's photoreceptor integration or brain processing. Methods for visualizing a spectral gamut raise challenges as do considerations of how to utilize such a data-set for producing superior color reproductions. Recent work has described a transformation of spectra reduced to 6-dimensions called LabPQR. LabPQR was designed as a hybrid space with three explicit colorimetric axes and three additional spectral reconstruction axes. In this paper spectral gamuts are discussed making use of LabPQR. Also, spectral gamut mapping is considered in light of the colorimetric-spectral duality of the LabPQR space.

  10. A rare case of failed healing in previously burned skin after a secondary burns.

    Science.gov (United States)

    Goldie, Stephen J; Parsons, Shaun; Menezes, Hana; Ives, Andrew; Cleland, Heather

    2017-01-01

    Patients presenting with large surface area burns are common in our practice; however, patients with a secondary large burn on pre-existing burn scars and grafts are rare and not reported. We report on an unusual case of a patient sustaining a secondary large burn to areas previously injured by a burn from a different mechanism. We discuss the potential implications when managing a case like this and suggest potential biological reasons why the skin may behave differently. Our patient was a 33-year-old man who presented with a 5% TBSA burn on skin scarred by a previous 40% total body surface area (TBSA) burn and skin grafts. Initially assessed as superficial partial thickness in depth, the wounds were treated conservatively with dressings; however, they failed to heal and became infected requiring surgical management. Burns sustained in areas of previous burn scars and grafts may behave differently to normal patterns of healing, requiring more aggressive management and surgical intervention at an early stage.

  11. A Multiwavelength Study of POX 52, a Dwarf Seyfert Galaxy with an Intermediate Mass Black Hole

    Science.gov (United States)

    Barth, Aaron

    2004-09-01

    POX 52 is a Seyfert 1 galaxy with unprecedented properties: its host galaxy is a dwarf elliptical, and its stellar velocity dispersion is only 36 km/s. The stellar velocity dispersion and the broad emission-line widths both suggest a black hole mass of order 10^5 solar masses. We request HST ACS/HRC imaging to perform a definitive measurement of the host galaxy structure; STIS UV and optical spectroscopy to study the nonstellar continuum and the structure of the broad-line region; and Chandra ACIS imaging to investigate the spectral and variability properties of the X-ray emission. The results of this program will give a detailed understanding of the host galaxy and accretion properties of one of the very few known black holes in the mass range around 10^5 solar masses.

  12. Repeated Prescribed Burning in Aspen

    Science.gov (United States)

    Donald A. Perala

    1974-01-01

    Infrequent burning weather, low flammability of the aspen-hardwood association, and prolific sprouting and seeding of shrubs and hardwoods made repeated dormant season burning a poor tool to convert good site aspen to conifers. Repeat fall burns for wildlife habitat maintenance is workable if species composition changes are not important.

  13. Accreting Black Holes

    OpenAIRE

    Begelman, Mitchell C.

    2014-01-01

    I outline the theory of accretion onto black holes, and its application to observed phenomena such as X-ray binaries, active galactic nuclei, tidal disruption events, and gamma-ray bursts. The dynamics as well as radiative signatures of black hole accretion depend on interactions between the relatively simple black-hole spacetime and complex radiation, plasma and magnetohydrodynamical processes in the surrounding gas. I will show how transient accretion processes could provide clues to these ...

  14. Naked black holes

    International Nuclear Information System (INIS)

    Horowitz, G.T.; Ross, S.F.

    1997-01-01

    It is shown that there are large static black holes for which all curvature invariants are small near the event horizon, yet any object which falls in experiences enormous tidal forces outside the horizon. These black holes are charged and near extremality, and exist in a wide class of theories including string theory. The implications for cosmic censorship and the black hole information puzzle are discussed. copyright 1997 The American Physical Society

  15. Ballistic hole magnetic microscopy

    NARCIS (Netherlands)

    Haq, E.; Banerjee, T.; Siekman, M.H.; Lodder, J.C.; Jansen, R.

    2005-01-01

    A technique to study nanoscale spin transport of holes is presented: ballistic hole magnetic microscopy. The tip of a scanning tunneling microscope is used to inject hot electrons into a ferromagnetic heterostructure, where inelastic decay creates a distribution of electron-hole pairs.

  16. 21 CFR 880.5180 - Burn sheet.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Burn sheet. 880.5180 Section 880.5180 Food and... Burn sheet. (a) Identification. A burn sheet is a device made of a porous material that is wrapped aroung a burn victim to retain body heat, to absorb wound exudate, and to serve as a barrier against...

  17. Black-hole driven winds

    International Nuclear Information System (INIS)

    Punsly, B.M.

    1988-01-01

    This dissertation is a study of the physical mechanism that allows a large scale magnetic field to torque a rapidly rotating, supermassive black hole. This is an interesting problem as it has been conjectured that rapidly rotating black holes are the central engines that power the observed extragalactic double radio sources. Axisymmetric solutions of the curved space-time version of Maxwell's equations in the vacuum do not torque black holes. Plasma must be introduced for the hole to mechanically couple to the field. The dynamical aspect of rotating black holes that couples the magnetic field to the hole is the following. A rotating black hole forces the external geometry of space-time to rotate (the dragging of inertial frames). Inside of the stationary limit surface, the ergosphere, all physical particle trajectories must appear to rotate in the same direction as the black hole as viewed by the stationary observers at asymptotic infinity. In the text, it is demonstrated how plasma that is created on field lines that thread both the ergosphere and the equatorial plane will be pulled by gravity toward the equator. By the aforementioned properties of the ergosphere, the disk must rotate. Consequently, the disk acts like a unipolar generator. It drives a global current system that supports the toroidal magnetic field in an outgoing, magnetically dominated wind. This wind carries energy (mainly in the form of Poynting flux) and angular momentum towards infinity. The spin down of the black hole is the ultimate source of this energy and angular momentum flux

  18. Physical functional outcome assessment of patients with major burns admitted to a UK Burn Intensive Care Unit.

    Science.gov (United States)

    Smailes, Sarah T; Engelsman, Kayleen; Dziewulski, Peter

    2013-02-01

    Determining the discharge outcome of burn patients can be challenging and therefore a validated objective measure of functional independence would assist with this process. We developed the Functional Assessment for Burns (FAB) score to measure burn patients' functional independence. FAB scores were taken on discharge from ICU (FAB 1) and on discharge from inpatient burn care (FAB 2) in 56 patients meeting the American Burn Association criteria for major burn. We retrospectively analysed prospectively collected data to measure the progress of patients' physical functional outcomes and to evaluate the predictive validity of the FAB score for discharge outcome. Mean age was 38.6 years and median burn size 35%. Significant improvements were made in the physical functional outcomes between FAB 1 and FAB 2 scores (pburn patients. Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.

  19. Genital burns in the national burn repository: incidence, etiology, and impact on morbidity and mortality.

    Science.gov (United States)

    Harpole, Bethany G; Wibbenmeyer, Lucy A; Erickson, Bradley A

    2014-02-01

    To better characterize national genital burns (GBs) characteristics using a large burn registry. We hypothesized that mortality and morbidity will be higher in patients with GBs. The National Burn Repository, a large North American registry of hospitalized burn patients, was queried for patients with GB. Burn characteristics and mechanism, demographics, mortality, and surgical interventions were retrieved. Outcomes of interest were mortality, hospital-acquired infection (HAI), and surgical intervention on the genitalia. Adjusted odds ratios (aOR) for outcomes were determined with binomial logistic regression controlling for age, total burn surface area, race, length of stay, gender, and inhalation injury presence. GBs were present in 1245 cases of 71,895 burns (1.7%). Patients with GB had significantly greater average total burn surface area, length of stay, and mortality. In patients with GB, surgery of the genitalia was infrequent (10.4%), with the aOR of receiving surgery higher among men (aOR 2.7, P burns (aOR 3.1, P <.002). Presence of a GB increased the odds of HAI (aOR 3.0, P <.0001) and urinary tract infections (aOR 3.4, P <.0001). GB was also an independent predictor of mortality (aOR 1.54) even after adjusting for the increased HAI risk. GBs are rare but associated with higher HAI rates and higher mortality after adjusting for well-established mortality risk factors. Although a cause and effect relationship cannot be established using these registry data, we believe this study suggests the need for special management considerations in GB cases to improve overall outcomes. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. The Burns Registry of Australia and New Zealand: progressing the evidence base for burn care.

    Science.gov (United States)

    Cleland, Heather; Greenwood, John E; Wood, Fiona M; Read, David J; Wong She, Richard; Maitz, Peter; Castley, Andrew; Vandervord, John G; Simcock, Jeremy; Adams, Christopher D; Gabbe, Belinda J

    2016-03-21

    Analysis of data from the Burns Registry of Australia and New Zealand (BRANZ) to determine the extent of variation between participating units in treatment and in specific outcomes during the first 4 years of its operation. BRANZ, an initiative of the Australian and New Zealand Burn Association, is a clinical quality registry developed in accordance with the Australian Commission on Safety and Quality in Healthcare national operating principles. Patients with burn injury who fulfil pre-defined criteria are transferred to and managed in designated burn units. There are 17 adult and paediatric units in Australia and New Zealand that manage almost all patients with significant burn injury. Twelve of these units treat adult patients. Data on 7184 adult cases were contributed by ten acute adult burn units to the registry between July 2010 and June 2014.Major outcomes: In-hospital mortality, hospital length of stay, skin grafting rates, and rates of admission to intensive care units. Considerable variations in unit profiles (including numbers of patients treated), in treatment and in outcomes were identified. Despite the highly centralised delivery of care to patients with severe or complex burn injury, and the relatively small number of specialist burn units, we found significant variation between units in clinical management and in outcomes. BRANZ data from its first 4 years of operation support its feasibility and the value of further development of the registry. Based on these results, the focus of ongoing research is to improve understanding of the reasons for variations in practice and of their effect on outcomes for patients, and to develop evidence-informed clinical guidelines for burn management in Australia and New Zealand.

  1. Development of the life impact burn recovery evaluation (LIBRE) profile: assessing burn survivors' social participation.

    Science.gov (United States)

    Kazis, Lewis E; Marino, Molly; Ni, Pengsheng; Soley Bori, Marina; Amaya, Flor; Dore, Emily; Ryan, Colleen M; Schneider, Jeff C; Shie, Vivian; Acton, Amy; Jette, Alan M

    2017-10-01

    Measuring the impact burn injuries have on social participation is integral to understanding and improving survivors' quality of life, yet there are no existing instruments that comprehensively measure the social participation of burn survivors. This project aimed to develop the Life Impact Burn Recovery Evaluation Profile (LIBRE), a patient-reported multidimensional assessment for understanding the social participation after burn injuries. 192 questions representing multiple social participation areas were administered to a convenience sample of 601 burn survivors. Exploratory factor analysis and confirmatory factor analysis (CFA) were used to identify the underlying structure of the data. Using item response theory methods, a Graded Response Model was applied for each identified sub-domain. The resultant multidimensional LIBRE Profile can be administered via Computerized Adaptive Testing (CAT) or fixed short forms. The study sample included 54.7% women with a mean age of 44.6 (SD 15.9) years. The average time since burn injury was 15.4 years (0-74 years) and the average total body surface area burned was 40% (1-97%). The CFA indicated acceptable fit statistics (CFI range 0.913-0.977, TLI range 0.904-0.974, RMSEA range 0.06-0.096). The six unidimensional scales were named: relationships with family and friends, social interactions, social activities, work and employment, romantic relationships, and sexual relationships. The marginal reliability of the full item bank and CATs ranged from 0.84 to 0.93, with ceiling effects less than 15% for all scales. The LIBRE Profile is a promising new measure of social participation following a burn injury that enables burn survivors and their care providers to measure social participation.

  2. BurnCase 3D software validation study: Burn size measurement accuracy and inter-rater reliability.

    Science.gov (United States)

    Parvizi, Daryousch; Giretzlehner, Michael; Wurzer, Paul; Klein, Limor Dinur; Shoham, Yaron; Bohanon, Fredrick J; Haller, Herbert L; Tuca, Alexandru; Branski, Ludwik K; Lumenta, David B; Herndon, David N; Kamolz, Lars-P

    2016-03-01

    The aim of this study was to compare the accuracy of burn size estimation using the computer-assisted software BurnCase 3D (RISC Software GmbH, Hagenberg, Austria) with that using a 2D scan, considered to be the actual burn size. Thirty artificial burn areas were pre planned and prepared on three mannequins (one child, one female, and one male). Five trained physicians (raters) were asked to assess the size of all wound areas using BurnCase 3D software. The results were then compared with the real wound areas, as determined by 2D planimetry imaging. To examine inter-rater reliability, we performed an intraclass correlation analysis with a 95% confidence interval. The mean wound area estimations of the five raters using BurnCase 3D were in total 20.7±0.9% for the child, 27.2±1.5% for the female and 16.5±0.1% for the male mannequin. Our analysis showed relative overestimations of 0.4%, 2.8% and 1.5% for the child, female and male mannequins respectively, compared to the 2D scan. The intraclass correlation between the single raters for mean percentage of the artificial burn areas was 98.6%. There was also a high intraclass correlation between the single raters and the 2D Scan visible. BurnCase 3D is a valid and reliable tool for the determination of total body surface area burned in standard models. Further clinical studies including different pediatric and overweight adult mannequins are warranted. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

  3. Accuracy of burn size estimation in patients transferred to adult Burn Units in Sydney, Australia: an audit of 698 patients.

    Science.gov (United States)

    Harish, Varun; Raymond, Andrew P; Issler, Andrea C; Lajevardi, Sepehr S; Chang, Ling-Yun; Maitz, Peter K M; Kennedy, Peter

    2015-02-01

    The purpose of this study was to compare burn size estimation between referring centres and Burn Units in adult patients transferred to Burn Units in Sydney, Australia. A review of all adults transferred to Burn Units in Sydney, Australia between January 2009 and August 2013 was performed. The TBSA estimated by the referring institution was compared with the TBSA measured at the Burns Unit. There were 698 adults transferred to a Burns Unit. Equivalent TBSA estimation between the referring hospital and Burns Unit occurred in 30% of patients. Overestimation occurred at a ratio exceeding 3:1 with respect to underestimation, with the difference between the referring institutions and Burns Unit estimation being statistically significant (Pburn-injured patients as well as in patients transferred more than 48h after the burn (Pburn (Pburns (≥20% TBSA) were found to have more satisfactory burn size estimations compared with less severe injuries (burn size assessment by referring centres. The systemic tendency for overestimation occurs throughout the entire TBSA spectrum, and persists with increasing time after the burn. Underestimation occurs less frequently but rises with increasing time after the burn and with increasing TBSA. Severe burns (≥20% TBSA) are more accurately estimated by the referring hospital. The inaccuracies in burn size assessment have the potential to result in suboptimal treatment and inappropriate referral to specialised Burn Units. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

  4. Burns in sub-Saharan Africa: A review.

    Science.gov (United States)

    Nthumba, Peter M

    2016-03-01

    Burns are important preventable causes of morbidity and mortality, with a disproportionate incidence in sub-Saharan Africa. The management of these injuries in sub-Saharan Africa is a challenge because of multiple other competing problems such as infectious diseases (HIV/AIDS, tuberculosis and malaria), terrorist acts and political instability. There is little investment in preventive measures, pre-hospital, in-hospital and post-discharge care of burns, resulting in high numbers of burns, high morbidity and mortality. Lack of data that can be used in legislation and policy formulation is a major hindrance in highlighting the problem of burns in this sub-region. An online search of publications on burns from sub-Saharan countries was performed. A total of 54 publications with 32,862 patients from 14 countries qualified for inclusion in the study. The average age was 15.3 years. Children aged 10 years and below represented over 80% of the burn patient population. Males constituted 55% of those who suffered burns. Scalds were the commonest cause of thermal injuries, accounting for 59% of all burns, while flame burns accounted for 33%. The burn mortality averaged 17%, or the death of one of every five burn victims. These statistics indicate the need for an urgent review of burn policies and related legislation across the sub-Saharan region to help reduce burns, and provide a safe environment for children. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.

  5. Black holes are hot

    International Nuclear Information System (INIS)

    Gibbons, G.

    1976-01-01

    Recent work, which has been investigating the use of the concept of entropy with respect to gravitating systems, black holes and the universe as a whole, is discussed. The resulting theory of black holes assigns a finite temperature to them -about 10 -7 K for ordinary black holes of stellar mass -which is in complete agreement with thermodynamical concepts. It is also shown that black holes must continuously emit particles just like ordinary bodies which have a certain temperature. (U.K.)

  6. Management of post burn hand deformities

    Directory of Open Access Journals (Sweden)

    Sabapathy S

    2010-10-01

    Full Text Available The hand is ranked among the three most frequent sites of burns scar contracture deformity. One of the major determinants of the quality of life in burns survivors is the functionality of the hands. Burns deformities, although largely preventable, nevertheless do occur when appropriate treatment is not provided in the acute situation or when they are part of a major burns. Reconstructive procedures can greatly improve the function of the hands. Appropriate choice of procedures and timing of surgery followed by supervised physiotherapy can be a boon for a burns survivor.

  7. Global biomass burning. Atmospheric, climatic, and biospheric implications

    International Nuclear Information System (INIS)

    Levine, J.S.

    1991-01-01

    Biomass burning is a significant source of atmospheric gases and, as such, may contribute to global climate changes. Biomass burning includes burning forests and savanna grasslands for land clearing, burning agricultural stubble and waste after harvesting, and burning biomass fuels. The chapters in this volume include the following topics: remote sensing of biomass burning from space;geographical distribution of burning; combustion products of burning in tropical, temperate and boreal ecosystems; burning as a global source of atmospheric gases and particulates; impacts of biomass burning gases and particulates on global climate; and the role of biomass burning on biodiversity and past global extinctions. A total of 1428 references are cited for the 63 chapters. Individual chapters are indexed separately for the data bases

  8. Burn-center quality improvement: are burn outcomes dependent on admitting facilities and is there a volume-outcome "sweet-spot"?

    Science.gov (United States)

    Hranjec, Tjasa; Turrentine, Florence E; Stukenborg, George; Young, Jeffrey S; Sawyer, Robert G; Calland, James F

    2012-05-01

    Risk factors of mortality in burn patients such as inhalation injury, patient age, and percent of total body surface area (%TBSA) burned have been identified in previous publications. However, little is known about the variability of mortality outcomes between burn centers and whether the admitting facilities or facility volumes can be recognized as predictors of mortality. De-identified data from 87,665 acute burn observations obtained from the National Burn Repository between 2003 and 2007 were used to estimate a multivariable logistic regression model that could predict patient mortality with reference to the admitting burn facility/facility volume, adjusted for differences in age, inhalation injury, %TBSA burned, and an additional factor, percent full thickness burn (%FTB). As previously reported, all three covariates (%TBSA burned, inhalation injury, and age) were found to be highly statistically significant risk factors of mortality in burn patients (P value improve the multivariable model. The treatment/admitting facility was found to be an independent mortality predictor, with certain hospitals having increased odds of death and others showing a protective effect (decreased odds ratio). Hospitals with high burn volumes had the highest risk of mortality. Mortality outcomes of patients with similar risk factors (%TBSA burned, inhalation injury, age, and %FTB) are significantly affected by the treating facility and their admission volumes.

  9. Research on mouse model of grade II corneal alkali burn

    Directory of Open Access Journals (Sweden)

    Jun-Qiang Bai

    2016-04-01

    Full Text Available AIM: To choose appropriate concentration of sodium hydroxide (NaOH solution to establish a stable and consistent corneal alkali burn mouse model in grade II. METHODS: The mice (n=60 were randomly divided into four groups and 15 mice each group. Corneal alkali burns were induced by placing circle filter paper soaked with NaOH solutions on the right central cornea for 30s. The concentrations of NaOH solutions of groups A, B, C, and D were 0.1 mol/L, 0.15 mol/L , 0.2 mol/L, and 1.0 mol/L respectively. Then these corneas were irrigated with 20 mL physiological saline (0.9% NaCl. On day 7 postburn, slit lamp microscope was used to observe corneal opacity, corneal epithelial sodium fluorescein staining positive rate, incidence of corneal ulcer and corneal neovascularization, meanwhile pictures of the anterior eyes were taken. Cirrus spectral domain optical coherence tomography was used to scan cornea to observe corneal epithelial defect and corneal ulcer. RESULTS: Corneal opacity scores ( were not significantly different between the group A and group B (P=0.097. Incidence of corneal ulcer in group B was significantly higher than that in group A (P=0.035. Incidence of corneal ulcer and perforation rate in group B was lower than that in group C. Group C and D had corneal neovascularization, and incidence of corneal neovascularization in group D was significantly higher than that in group C (P=0.000. CONCLUSION: Using 0.15 mol/L NaOH can establish grade II mouse model of corneal alkali burns.

  10. Burn-related peripheral neuropathy: A systematic review.

    Science.gov (United States)

    Tu, Yiji; Lineaweaver, William C; Zheng, Xianyou; Chen, Zenggan; Mullins, Fred; Zhang, Feng

    2017-06-01

    Peripheral neuropathy is the most frequent disabling neuromuscular complication of burns. However, the insidious and progressive onset of burn neuropathy makes it often undiagnosed or overlooked. In our study, we reviewed the current studies on the burn-related peripheral neuropathy to summarize the morbidity, mechanism, detecting method and management of peripheral neuropathy in burn patients. Of the 1533 burn patients included in our study, 98 cases (6.39%) were presented with peripheral neuropathy. Thermal and electrical burns were the most common etiologies. Surgical procedures, especially nerve decompression, showed good effect on functional recovery of both acute and delayed peripheral neuropathy in burn patients. It is noteworthy that, for early detection and prevention of peripheral neuropathy, electrodiagnostic examinations should be performed on burn patients independent of symptoms. Still, the underlying mechanisms of burn-related peripheral neuropathy remain to be clarified. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

  11. Evaluating the Effects of Fire on Semi-Arid Savanna Ecosystem Productivity Using Integrated Spectral and Gas Exchange Measurements

    Science.gov (United States)

    Raub, H. D.; Jimenez, J. R.; Gallery, R. E.; Sutter, L., Jr.; Barron-Gafford, G.; Smith, W. K.

    2017-12-01

    Drylands account for 40% of the land surface and have been identified as increasingly important in driving interannual variability of the land carbon sink. Yet, understanding of dryland seasonal ecosystem productivity dynamics - termed Gross Primary Productivity (GPP) - is limited due to complex interactions between vegetation health, seasonal drought dynamics, a paucity of long-term measurements across these under-studied regions, and unanticipated disturbances from varying fire regimes. For instance, fire disturbance has been found to either greatly reduce post-fire GPP through vegetation mortality or enhance post-fire GPP though increased resource availability (e.g., water, light, nutrients, etc.). Here, we explore post-fire ecosystem recovery by evaluating seasonal GPP dynamics for two Ameriflux eddy covariance flux tower sites within the Santa Rita Experimental Range of southeastern Arizona: 1) the US-SRG savanna site dominated by a mix of grass and woody mesquite vegetation that was burned in May 2017, and 2) the US-SRM savanna site dominated by similar vegetation but unburned for the full measurement record. For each site, we collected leaf-level spectral and gas exchange measurements, as well as leaf-level chemistry and soil chemistry to characterize differences in nutrient availability and microbial activity throughout the 2017 growing season. From spectral data, we derived and evaluated multiple common vegetation metrics, including normalized difference vegetation index (NDVI), photochemical reflectivity index (PRI), near-infrared reflectance (NIRv), and MERIS terrestrial chlorophyll index (MTCI). Early results suggest rates of photosynthesis were enhanced at the burned site, with productivity increasing immediately following the onset of monsoonal precipitation; whereas initial photosynthesis at the unburned site remained relatively low following first monsoonal rains. MTCI values for burned vegetation appear to track higher levels of leaf-level nitrogen

  12. Creating a social work link to the burn community: a research team goes to burn camp.

    Science.gov (United States)

    Williams, Nancy R; Reeves, Patricia M; Cox, Ellen R; Call, Serena B

    2004-01-01

    Social work faculty and graduate students conducted focus groups with 52 burn-injured adolescents from three burn camps to explore perceptions of their camp experience. Three themes emerged from data analysis that suggest burn camps play an important role in participants' lives. Camp is a place where burn-injured adolescents: (1) feel "normal" and accepted; (2) acquire insight in regard to self and meaning in life; and (3) gain confidence, increase self-esteem, and develop empathy. This project highlights how the use of qualitative research methods with grassroots organizations such as burn camps can serve as a link to greater social work involvement with this community.

  13. Intermediate-Mass Black Holes

    Science.gov (United States)

    Miller, M. Coleman; Colbert, E. J. M.

    2004-01-01

    The mathematical simplicity of black holes, combined with their links to some of the most energetic events in the universe, means that black holes are key objects for fundamental physics and astrophysics. Until recently, it was generally believed that black holes in nature appear in two broad mass ranges: stellar-mass (M~3 20 M⊙), which are produced by the core collapse of massive stars, and supermassive (M~106 1010 M⊙), which are found in the centers of galaxies and are produced by a still uncertain combination of processes. In the last few years, however, evidence has accumulated for an intermediate-mass class of black holes, with M~102 104 M⊙. If such objects exist they have important implications for the dynamics of stellar clusters, the formation of supermassive black holes, and the production and detection of gravitational waves. We review the evidence for intermediate-mass black holes and discuss future observational and theoretical work that will help clarify numerous outstanding questions about these objects.

  14. Current concepts on burn wound conversion – a review of recent advances in understanding the secondary progressions of burns

    Science.gov (United States)

    Salibian, Ara A.; Del Rosario, Angelica Tan; De Almeida Moura Severo, Lucio; Nguyen, Long; Banyard, Derek A.; Toranto, Jason D.; Evans, Gregory R.D.; Widgerow, Alan D.

    2016-01-01

    Burn wound conversion describes the process by which superficial partial thickness burns convert into deeper burns necessitating surgical intervention. Fully understanding and thus controlling this phenomenon continues to defy burn surgeons. However, potentially guiding burn wound progression so as to obviate the need for surgery while still bringing about healing with limited scarring is the major unmet challenge. Comprehending the pathophysiologic background contributing to deeper progression of these burns is an essential prerequisite to planning any intervention. In this study, a review of articles examining burn wound progression over the last five years was conducted to analyze trends in recent burn progression research, determine changes in understanding of the pathogenesis of burn conversion, and subsequently examine the direction for future research in developing therapies. The majority of recent research focuses on applying therapies from other disease processes to common underlying pathogenic mechanisms in burn conversion. While ischemia, inflammation, and free oxygen radicals continue to demonstrate a critical role in secondary necrosis, novel mechanisms such as autophagy have also been shown to contribute affect significantly burn progression significantly. Further research will have to determine whether multiple mechanisms should be targeted when developing clinical therapies. PMID:26787127

  15. [Burns care following a nuclear incident].

    Science.gov (United States)

    Bargues, L; Donat, N; Jault, P; Leclerc, T

    2010-09-30

    Radiation injuries are usually caused by radioactive isotopes in industry. Detonations of nuclear reactors, the use of military nuclear weapons, and terrorist attacks represent a risk of mass burn casualties. Ionizing radiation creates thermal burns, acute radiation syndrome with pancytopenia, and a delayed cutaneous syndrome. After a latency period, skin symptoms appear and the depth of tissue damages increase with dose exposure. The usual burn resuscitation protocols have to be applied. Care of these victims also requires assessment of the level of radiation, plus decontamination by an experienced team. In nuclear disasters, the priority is to optimize the available resources and reserve treatment to patients with the highest probability of survival. After localized nuclear injury, assessment of burn depth and surgical techniques of skin coverage are the main difficulties in a burn centre. Training in medical facilities and burn centres is necessary in the preparation for management of the different types of burn injuries.

  16. Black hole multiplicity at particle colliders (Do black holes radiate mainly on the brane?)

    International Nuclear Information System (INIS)

    Cavaglia, Marco

    2003-01-01

    If gravity becomes strong at the TeV scale, we may have the chance to produce black holes at particle colliders. In this Letter we revisit some phenomenological signatures of black hole production in TeV-gravity theories. We show that the bulk-to-brane ratio of black hole energy loss during the Hawking evaporation phase depends crucially on the black hole greybody factors and on the particle degrees of freedom. Since the greybody factors have not yet been calculated in the literature, and the particle content at trans-Planckian energies is not known, it is premature to claim that the black hole emits mainly on the brane. We also revisit the decay time and the multiplicity of the decay products of black hole evaporation. We give general formulae for black hole decay time and multiplicity. We find that the number of particles produced during the evaporation phase may be significantly lower than the average multiplicity which has been used in the past literature

  17. Changes in the Spectral Features of Zinc Phthalocyanine Induced by Nitrogen Dioxide Gas in Solution and in Solid Polymer Nanofiber Media.

    Science.gov (United States)

    Zugle, Ruphino; Tetteh, Samuel

    2017-03-01

    The changes in the spectral features of zinc phthalocyanine in the visible domain as a result of its interaction with nitrogen dioxide gas were assessed in this work. This was done both in solution and when the phthalocyanine was incorporated into a solid polystyrene polymer nanofiber matrix. The spectral changes were found to be spontaneous and marked in both cases suggesting a rapid response criterion for the detection of the gas. In particular, the functionalised nano-fabric material could serve as a practical fire alarm system as it rapidly detects the nitrogen dioxide gas generated during burning.

  18. String-Corrected Black Holes

    Energy Technology Data Exchange (ETDEWEB)

    Hubeny, V.

    2005-01-12

    We investigate the geometry of four dimensional black hole solutions in the presence of stringy higher curvature corrections to the low energy effective action. For certain supersymmetric two charge black holes these corrections drastically alter the causal structure of the solution, converting seemingly pathological null singularities into timelike singularities hidden behind a finite area horizon. We establish, analytically and numerically, that the string-corrected two-charge black hole metric has the same Penrose diagram as the extremal four-charge black hole. The higher derivative terms lead to another dramatic effect--the gravitational force exerted by a black hole on an inertial observer is no longer purely attractive. The magnitude of this effect is related to the size of the compactification manifold.

  19. Video studies of passage by Anopheles gambiae mosquitoes through holes in a simulated bed net: effects of hole size, hole orientation and net environment.

    Science.gov (United States)

    Sutcliffe, James; Colborn, Kathryn L

    2015-05-13

    Holes in netting provide potential routes for mosquitoes to enter ITNs. Despite this, there is little information on how mosquitoes respond to holes in bed nets and how their responses are affected by hole size, shape and orientation or by ambient conditions around the net. Female Anopheles gambiae (G3) were recorded in a simulated bed net consisting of two sizes of untreated netting-covered behavioural arenas placed above and beside (to simulate the bed net roof and sides respectively) the experimenter who was a source of host cues from 'inside' the net. A round hole of 9 mm or 13 mm diameter was cut into the centre of the netting of each arena. Videos of unfed female mosquitoes in arenas were analysed for time spent flying, walking and standing still and for exit through the hole. The effects of the experimenter on temperature and relative humidity around the simulated net were also measured. Mosquitoes were significantly more active in overhead arenas than in arenas to the side. Hole passage was significantly more likely in smaller arenas than larger ones and for larger holes than smaller ones. In arenas to the side, hole passage rate through small holes was about 50% less likely than what could be explained by area alone. Passage rate through holes in overhead arenas was consistent with hole area. Temperature in arenas did not strongly reflect the experimenter's presence in the simulated net. Relative humidity and absolute humidity in overhead arenas, but not in arenas to the side, were immediately affected by experimenter presence. Higher levels of activity in overhead arenas than in arenas to the side were likely due to the rising heat and humidity plume from the experimenter. Lower than expected passage rates through smaller vertically oriented holes may have been be due to an edge effect that does not apply to horizontally oriented holes. Results suggest that current methods of assessing the importance of physical damage to ITNs may not accurately reflect

  20. Structural differences between glycosylated, disulfide-linked heterodimeric Knob-into-Hole Fc fragment and its homodimeric Knob-Knob and Hole-Hole side products.

    Science.gov (United States)

    Kuglstatter, A; Stihle, M; Neumann, C; Müller, C; Schaefer, W; Klein, C; Benz, J

    2017-09-01

    An increasing number of bispecific therapeutic antibodies are progressing through clinical development. The Knob-into-Hole (KiH) technology uses complementary mutations in the CH3 region of the antibody Fc fragment to achieve heavy chain heterodimerization. Here we describe the X-ray crystal structures of glycosylated and disulfide-engineered heterodimeric KiH Fc fragment and its homodimeric Knob-Knob and Hole-Hole side products. The heterodimer structure confirms the KiH design principle and supports the hypothesis that glycosylation stabilizes a closed Fc conformation. Both homodimer structures show parallel Fc fragment architectures, in contrast to recently reported crystal structures of the corresponding aglycosylated Fc fragments which in the absence of disulfide mutations show an unexpected antiparallel arrangement. The glycosylated Knob-Knob Fc fragment is destabilized as indicated by variability in the relative orientation of its CH3 domains. The glycosylated Hole-Hole Fc fragment shows an unexpected intermolecular disulfide bond via the introduced Y349C Hole mutation which results in a large CH3 domain shift and a new CH3-CH3 interface. The crystal structures of glycosylated, disulfide-linked KiH Fc fragment and its Knob-Knob and Hole-Hole side products reported here will facilitate further design of highly efficient antibody heterodimerization strategies. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  1. Ice & Fire: the Burning Question

    DEFF Research Database (Denmark)

    van Gelderen, Laurens; Jomaas, Grunde

    2017-01-01

    With the Arctic opening up to new shipping routes and increased oil exploration and production due to climate change, the risk of an Arctic oil spill is increasing. Of the classic oil spill response methods (mechanical recovery, dispersants and in-situ burning), in-situ burning is considered...... to be particularly a suitable response method in the Arctic. In-situ burning aims to remove the oil from the marine environment by burning it from the water surface. A recent Ph.D. thesis from the Technical University of Denmark has provided some new insights with respect to the fire science behind this response...

  2. Tomographic Structural Changes of Retinal Layers after Internal Limiting Membrane Peeling for Macular Hole Surgery.

    Science.gov (United States)

    Faria, Mun Yueh; Ferreira, Nuno P; Cristóvao, Diana M; Mano, Sofia; Sousa, David Cordeiro; Monteiro-Grillo, Manuel

    2018-01-01

    To highlight tomographic structural changes of retinal layers after internal limiting membrane (ILM) peeling in macular hole surgery. Nonrandomized prospective, interventional study in 38 eyes (34 patients) subjected to pars plana vitrectomy and ILM peeling for idiopathic macular hole. Retinal layers were assessed in nasal and temporal regions before and 6 months after surgery using spectral domain optical coherence tomography. Total retinal thickness increased in the nasal region and decreased in the temporal region. The retinal nerve fiber layer (RNFL), ganglion cell layer (GCL), and inner plexiform layer (IPL) showed thinning on both nasal and temporal sides of the fovea. The thickness of the outer plexiform layer (OPL) increased. The outer nuclear layer (ONL) and outer retinal layers (ORL) increased in thickness after surgery in both nasal and temporal regions. ILM peeling is associated with important alterations in the inner retinal layer architecture, with thinning of the RNFL-GCL-IPL complex and thickening of OPL, ONL, and ORL. These structural alterations can help explain functional outcome and could give indications regarding the extent of ILM peeling, even though peeling seems important for higher rate of hole closure. © 2017 S. Karger AG, Basel.

  3. Sedation and Analgesia in Burn

    Directory of Open Access Journals (Sweden)

    Özkan Akıncı

    2011-07-01

    Full Text Available Burn injury is one of the most serious injuries that mankind may face. In addition to serious inflammation, excessive fluid loss, presence of hemodynamic instability due to intercurrent factors such as debridements, infections and organ failure, very different levels and intensities of pain, psychological problems such as traumatic stress disorder, depression, delirium at different levels that occur in patient with severe burn are the factors which make it difficult to provide the patient comfort. In addition to a mild to moderate level of baseline permanent pain in burn patients, which is due to tissue damage, there is procedural pain as well, which occurs by treatments such as grafting and dressings, that are severe, short-term burst style 'breakthrough' pain. Movement and tactile stimuli are also seen in burn injury as an effect to sensitize the peripheral and central nervous system. Even though many burn centers have established protocols to struggle with the pain, studies show that pain relief still inadequate in burn patients. Therefore, the treatment of burn pain and the prevention of possible emergence of future psychiatric problems suc as post-traumatic stress disorder, the sedative and anxiolytic agents should be used as a recommendation according to the needs and hemodynamic status of individual patient. (Journal of the Turkish Society Intensive Care 2011; 9 Suppl: 26-30

  4. Internal structure of black holes

    International Nuclear Information System (INIS)

    Cvetic, Mirjam

    2013-01-01

    Full text: We review recent progress that sheds light on the internal structure of general black holes. We first summarize properties of general multi-charged rotating black holes both in four and five dimensions. We show that the asymptotic boundary conditions of these general asymptotically flat black holes can be modified such that a conformal symmetry emerges. These subtracted geometries preserve the thermodynamic properties of the original black holes and are of the Lifshitz type, thus describing 'a black hole in the asymptotically conical box'. Recent efforts employ solution generating techniques to construct interpolating geometries between the original black hole and their subtracted geometries. Upon lift to one dimension higher, these geometries lift to AdS 3 times a sphere, and thus provide a microscopic interpretation of the black hole entropy in terms of dual two-dimensional conformal field theory. (author)

  5. Survey of the Statewide Impact of Payer Source on Referral of Small Burns to Burn Centers.

    Science.gov (United States)

    Penny, Rachel; Coffey, Rebecca; Jones, Larry; Bailey, J Kevin

    It is generally agreed that patients with large burns will be referred to organized burn centers, however, the referral of patients with smaller burns is less certain. A two-part survey was conducted to identify referral patterns for burn patients that meet American Burn Association referral criteria, and any effect insurance type might have on the referral patterns. The emergency departments of our state hospital association's member hospitals were contacted seeking a referral for a fictitious patient with a third-degree scald of the dominant hand. The referral sites were contacted twice, first stating that the patient had commercial insurance, next stating that the patient had Medicaid. Data collected included wait time for an appointment or reasons for denial of an appointment. Of 218 hospitals, 46 were excluded because they did not offer emergency care, and eight because they were listed as burn centers on the American Burn Association website. Of the remaining 164, 119 (73%) would refer to a burn center, 21 (13%) to a plastic surgeon, 10 (6%) to a hand surgeon, 7 (4%) to a wound center, 7 (4%) to another nonburn physician resource. There was no difference in wait time to the first available appointment with regards to insurance type (6.56 ± 4.68 vs 6.53 ± 5.05 days). Our state's referral pattern gives us insight into the regional referral pattern. This information will be used to guide a focused education and communication program to provide better service for the burn victims of our state.

  6. Pediatric Burns: A Single Institution Retrospective Review of Incidence, Etiology, and Outcomes in 2273 Burn Patients (1995-2013).

    Science.gov (United States)

    Lee, Christina J; Mahendraraj, Krishnaraj; Houng, Abraham; Marano, Michael; Petrone, Sylvia; Lee, Robin; Chamberlain, Ronald S

    Unintentional burn injury is the third most common cause of death in the U.S. for children age 5 to 9, and accounts for major morbidity in the pediatric population. Pediatric burn admission data from U.S. institutions has not been reported recently. This study assesses all pediatric burn admissions to a State wide Certified Burn Treatment Center to evaluate trends in demographics, burn incidence, and cause across different age groups. Demographic and clinical data were collected on 2273 pediatric burn patients during an 18-year period (1995-2013). Pediatric patients were stratified by age into "age 0 to 6," "age 7 to 12," and "age 13 to 18." Data were obtained from National Trauma Registry of the American College of Surgeons and analyzed using standard statistical methodology. A total of 2273 burn patients under age 18 were treated between 1995 and 2013. A total of 1663 (73.2%) patients were ages 0 to 6, 294 (12.9%) were 7 to 12, and 316 (13.9%) were age 13 to 18. A total of 1400 (61.6%) were male and 873 (38.4%) were female (male:female ratio of 1.6:1). Caucasians had the highest burn incidence across all age groups (40.9%), followed by African-Americans (33.6%), P burns occurred at home, P burned was 8.9%, with lower extremity being the most common site (38.5%). Scald burns constituted the majority of cases (71.1%, n = 1617), with 53% attributable to hot liquids related to cooking, including coffee or tea, P burns were the dominant cause (53.8%). Overall mean length of stay was 10.5 ± 10.8 days for all patients, and15.5 ± 12 for those admitted to the intensive care unit, P burn injuries are scald burns that occur at home and primarily affect the lower extremities in Caucasian and African-American males. Among Caucasian teenagers flame burns predominate. Mean length of stay was 10 days, 23% of patients required skin grafting surgery, and mortality was 0.9%. The results of this study highlight the need for primary prevention programs focusing on avoiding

  7. Involving burn survivors in agenda setting on burn research: an added value?

    NARCIS (Netherlands)

    Broerse, J.E.W.; Zweekhorst, M.B.M.; Van Rensen, A.J.M.L.; De Haan, M.J.M.

    2010-01-01

    Background and aim: The role of burn survivors in burn research is usually restricted to being objects of study and beneficiaries of research results, while decision-making on research is traditionally the domain of a small group of experts, mainly scientists. In this article we compare the research

  8. Quantum effects in black holes

    International Nuclear Information System (INIS)

    Frolov, V.P.

    1979-01-01

    A strict definition of black holes is presented and some properties with regard to their mass are enumerated. The Hawking quantum effect - the effect of vacuum instability in the black hole gravitational field, as a result of shich the black hole radiates as a heated body is analyzed. It is shown that in order to obtain results on the black hole radiation it is sufficient to predetermine the in-vacuum state at a time moment in the past, when the collapsing body has a large size, and its gravitational field can be neglected. The causes and the place of particle production by the black hole, and also the space-time inside the black hole, are considered

  9. Echoes of chaos from string theory black holes

    Energy Technology Data Exchange (ETDEWEB)

    Balasubramanian, Vijay [David Rittenhouse Laboratory, University of Pennsylvania,Philadelphia, PA 19104 (United States); Theoretische Natuurkunde, Vrije Universiteit Brussel (VUB),and International Solvay Institutes,Pleinlaan 2, B-1050 Brussels (Belgium); Craps, Ben [Theoretische Natuurkunde, Vrije Universiteit Brussel (VUB),and International Solvay Institutes,Pleinlaan 2, B-1050 Brussels (Belgium); Czech, Bartłomiej [Institute for Advanced Study,Princeton, NJ 08540 (United States); Sárosi, Gábor [David Rittenhouse Laboratory, University of Pennsylvania,Philadelphia, PA 19104 (United States); Theoretische Natuurkunde, Vrije Universiteit Brussel (VUB),and International Solvay Institutes,Pleinlaan 2, B-1050 Brussels (Belgium)

    2017-03-29

    The strongly coupled D1-D5 conformal field theory is a microscopic model of black holes which is expected to have chaotic dynamics. Here, we study the weak coupling limit of the theory where it is integrable rather than chaotic. In this limit, the operators creating microstates of the lowest mass black hole are known exactly. We consider the time-ordered two-point function of light probes in these microstates, normalized by the same two-point function in vacuum. These correlators display a universal early-time decay followed by late-time sporadic behavior. To find a prescription for temporal coarse-graining of these late fluctuations we appeal to random matrix theory, where we show that a progressive time-average smooths the spectral form factor (a proxy for the 2-point function) in a typical draw of a random matrix. This coarse-grained quantity reproduces the matrix ensemble average to a good approximation. Employing this coarse-graining in the D1-D5 system, we find that the early-time decay is followed by a dip, a ramp and a plateau, in remarkable qualitative agreement with recent studies of the Sachdev-Ye-Kitaev (SYK) model. We study the timescales involved, comment on similarities and differences between our integrable model and the chaotic SYK model, and suggest ways to extend our results away from the integrable limit.

  10. Orion Burn Management, Nominal and Response to Failures

    Science.gov (United States)

    Odegard, Ryan; Goodman, John L.; Barrett, Charles P.; Pohlkamp, Kara; Robinson, Shane

    2016-01-01

    An approach for managing Orion on-orbit burn execution is described for nominal and failure response scenarios. The burn management strategy for Orion takes into account per-burn variations in targeting, timing, and execution; crew and ground operator intervention and overrides; defined burn failure triggers and responses; and corresponding on-board software sequencing functionality. Burn-to- burn variations are managed through the identification of specific parameters that may be updated for each progressive burn. Failure triggers and automatic responses during the burn timeframe are defined to provide safety for the crew in the case of vehicle failures, along with override capabilities to ensure operational control of the vehicle. On-board sequencing software provides the timeline coordination for performing the required activities related to targeting, burn execution, and responding to burn failures.

  11. Black hole masses in active galactic nuclei

    Science.gov (United States)

    Denney, Kelly D.

    2010-11-01

    We present the complete results from two, high sampling-rate, multi-month, spectrophotometric reverberation mapping campaigns undertaken to obtain either new or improved Hbeta reverberation lag measurements for several relatively low-luminosity active galactic nuclei (AGNs). We have reliably measured the time delay between variations in the continuum and Hbeta emission line in seven local Seyfert 1 galaxies. These measurements are used to calculate the mass of the supermassive black hole at the center of each of these AGNs. We place our results in context to the most current calibration of the broad-line region (BLR) RBLR-L relationship, where our results remove many outliers and significantly reduce the scatter at the low-luminosity end of this relationship. A detailed analysis of the data from our high sampling rate, multi-month reverberation mapping campaign in 2007 reveals that the Hbeta emission region within the BLRs of several nearby AGNs exhibit a variety of kinematic behaviors. Through a velocity-resolved reverberation analysis of the broad Hbeta emission-line flux variations in our sample, we reconstruct velocity-resolved kinematic signals for our entire sample and clearly see evidence for outflowing, infalling, and virialized BLR gas motions in NGC 3227, NGC 3516, and NGC 5548, respectively. Finally, we explore the nature of systematic errors that can arise in measurements of black hole masses from single-epoch spectra of AGNs by utilizing the many epochs available for NGC 5548 and PG1229+204 from reverberation mapping databases. In particular, we examine systematics due to AGN variability, contamination due to constant spectral components (i.e., narrow lines and host galaxy flux), data quality (i.e., signal-to-noise ratio, S/N), and blending of spectral features. We investigate the effect that each of these systematics has on the precision and accuracy of single-epoch masses calculated from two commonly-used line-width measures by comparing these

  12. STRONGER REFLECTION FROM BLACK HOLE ACCRETION DISKS IN SOFT X-RAY STATES

    International Nuclear Information System (INIS)

    Steiner, James F.; Remillard, Ronald A.; García, Javier A.; McClintock, Jeffrey E.

    2016-01-01

    We analyze 15,000 spectra of 29 stellar-mass black hole (BH) candidates collected over the 16 year mission lifetime of Rossi X-ray Timing Explorer using a simple phenomenological model. As these BHs vary widely in luminosity and progress through a sequence of spectral states, which we broadly refer to as hard and soft, we focus on two spectral components: the Compton power law and the reflection spectrum it generates by illuminating the accretion disk. Our proxy for the strength of reflection is the equivalent width of the Fe–K line as measured with respect to the power law. A key distinction of our work is that for all states we estimate the continuum under the line by excluding the thermal disk component and using only the component that is responsible for fluorescing the Fe–K line, namely, the Compton power law. We find that reflection is several times more pronounced (∼3) in soft compared to hard spectral states. This is most readily caused by the dilution of the Fe line amplitude from Compton scattering in the corona, which has a higher optical depth in hard states. Alternatively, this could be explained by a more compact corona in soft (compared to hard) states, which would result in a higher reflection fraction.

  13. STRONGER REFLECTION FROM BLACK HOLE ACCRETION DISKS IN SOFT X-RAY STATES

    Energy Technology Data Exchange (ETDEWEB)

    Steiner, James F.; Remillard, Ronald A. [MIT Kavli Institute for Astrophysics and Space Research, MIT, 70 Vassar Street, Cambridge, MA 02139 (United States); García, Javier A.; McClintock, Jeffrey E., E-mail: jsteiner@mit.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2016-10-01

    We analyze 15,000 spectra of 29 stellar-mass black hole (BH) candidates collected over the 16 year mission lifetime of Rossi X-ray Timing Explorer using a simple phenomenological model. As these BHs vary widely in luminosity and progress through a sequence of spectral states, which we broadly refer to as hard and soft, we focus on two spectral components: the Compton power law and the reflection spectrum it generates by illuminating the accretion disk. Our proxy for the strength of reflection is the equivalent width of the Fe–K line as measured with respect to the power law. A key distinction of our work is that for all states we estimate the continuum under the line by excluding the thermal disk component and using only the component that is responsible for fluorescing the Fe–K line, namely, the Compton power law. We find that reflection is several times more pronounced (∼3) in soft compared to hard spectral states. This is most readily caused by the dilution of the Fe line amplitude from Compton scattering in the corona, which has a higher optical depth in hard states. Alternatively, this could be explained by a more compact corona in soft (compared to hard) states, which would result in a higher reflection fraction.

  14. Single-pulse characteristics of the Xe(L) amplifier on the Xe35+ (3d→2p) transition array at λ ≅ 2.86 A

    International Nuclear Information System (INIS)

    Borisov, Alex B; Song Xiangyang; Zhang Ping; McCorkindale, John C; Khan, Shahab F; De Jonghe, Richard; Poopalasingam, Sankar; Zhao, Ji; Boyer, Keith; Rhodes, Charles K

    2006-01-01

    The triple comparison of (1) single-pulse spectral data, recorded with a CCD-equipped von Hamos spectrometer both axially and transversely; (2) axially measured time-integrated spectra registered on a film and (3) single-pulse x-ray images of the morphology of the self-trapped plasma channel, recorded simultaneously with the single-pulse spectra, establishes several leading characteristics of the saturated amplification observed on the Xe 35+ transition array at λ ≅ 2.86 A. The chief findings are (α) absolute positive correlation of amplification with the formation of a plasma channel, (β) a perfect spectral match of the amplified transitions in the comparison of axially recorded single-pulse and time-integrated film data and (γ) exact spectral correspondence of both the axially registered single-pulse and time-integrated film data with single-pulse transversely measured spectra exhibiting deep spectral hole burning at the position of the Xe 35+ array. (letter to the editor)

  15. The absorption budget of fresh biomass burning aerosol from realistic laboratory fires

    Science.gov (United States)

    Wagner, N. L.; Adler, G. A.; Franchin, A.; Lamb, K.; Manfred, K.; Middlebrook, A. M.; Selimovic, V.; Schwarz, J. P.; Washenfelder, R. A.; Womack, C.; Yokelson, R. J.

    2017-12-01

    Wildfires are expected to increase globally due to climate change. The smoke from these wildfires has a highly uncertain radiative effect, largely due to the lack of detailed understanding of its optical properties. As part of the NOAA FIREX project, we have measured the optical properties of smoke primarily from laboratory burning of North American fuels at the Missoula Fire Sciences Laboratory. Here, we present a budget of the aerosol absorption from a portion of the laboratory fires. The total aerosol absorption was measured with photoacoustic spectrometers (PAS) at four wavelengths (405 nm, 532 nm, 660 nm, 870 nm) spanning the visible spectral region. The aerosol absorption is attributed to black carbon which absorbs broadly across the visible and ultraviolet (UV) spectral region and brown carbon (BrC) which absorbs in the blue and UV spectral regions. Then aerosol absorption measurements are compared with measurements of refractory black carbon (rBC) concentration by laser induced incandescence (SP2) and measurements of BrC concentration from a particle-into-liquid sampler coupled to a liquid absorption cell (BrC-PILS). Periodically, a thermodenuder was inserted upstream of all of the instruments to constrain the relationship between aerosol volatility and absorption. We synthesize these measurements to constrain the various contributors to total absorption including effects of lensing on rBC absorption, and of BrC that is not volatilized in the thermodenuder.

  16. Comparison of the General Health, Self-Esteem and Social Support in Self-Inflicted Burn Patients and Non Self Inflicted Burn Patients of the Choromy Accidental and Burning Hospital of Ganaveh

    Directory of Open Access Journals (Sweden)

    MS Enayati

    2006-04-01

    Full Text Available ABSTRACT: Introduction & Objective: Self-inflicted burn is a violent method of suicide. Since our society faces lots of psychological, social, personal and economical problems due to self-inflicted burn, more survey for this event can assist us to know its causes and prevent from its occurrence. This research was carried out to compare general health, self- esteem and social support in patient's self-inflicted burn and non-self-inflicted burn of the Choromy accidental and burning hospital in Ganaveh. Materials & Methods: This is a descriptive – analytic study. The sample consisted of 60 inpatients burnt (males & females of the Choromy accidental and burning hospital (Ganaveh. The method of sampling was simple random. Participants completed the General Health Questionnaire (G.H.Q- 28 of Goldberg, Cooper Smith’s questionnaire of self–esteem and Philip’s social support scale. Multivariate analysis of variance (MANOVA and T-test were the major statistical analysis in this research. Results: The mean and standard deviation of the general health were 44.57 ± 14.65 for self-inflicted burn persons and for non - self inflicted burn they were 10.83 ± 6.27. In the self–esteem variable, the mean and the standard deviation were 57.90 ± 4.94 for self-inflicted burn persons and 55.47 ± 6.04 for non-self inflicted burn ones. Mean and standard deviation of whole social supporting were 20.40 ± 4.94 for self-inflicted burn persons and 23.73 ± 1.17 for non-self inflicted burn group. The findings showed significant differences between the two groups from viewpoint of general health and social supporting while there were no significant differences between two groups in case of self–esteem. Conclusion: There are a significant relationship between general health, social supporting and self-inflicted burn.Therefore, in order to prevent self inflicted burn it is suggested that we make a relationship between persons and societies, families, groups and

  17. Global biomass burning: Atmospheric, climatic, and biospheric implications

    International Nuclear Information System (INIS)

    Levine, J.S.

    1991-01-01

    As a significant source of atmospheric gases, biomass burning must be addressed as a major environmental problem. Biomass burning includes burning forests and savanna grasslands for land clearing and conversion, burning agricultural stubble and waste after harvesting, and burning biomass fuels. The editor discusses the history of biomass burning and provides an overview of the individual chapters

  18. 30 CFR 57.7055 - Intersecting holes.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Intersecting holes. 57.7055 Section 57.7055... Jet Piercing Drilling-Surface and Underground § 57.7055 Intersecting holes. Holes shall not be drilled where there is a danger of intersecting a misfired hole or a hole containing explosives, blasting agents...

  19. Fire-fighting burning oil wells

    International Nuclear Information System (INIS)

    Newbury, Herbert; Risk, Stewart.

    1993-01-01

    A method of extinguishing burning oil wells is presented which involves dispensing liquid nitrogen to the burning site to prevent or inhibit oxygen from fuelling the flames. To carry out the method a remotely operated vehicle is described which is provided with a source of liquid nitrogen and an articulated deployment boom capable of supplying the liquid nitrogen to the site of a burning oil well. (Author)

  20. 30 CFR 56.7055 - Intersecting holes.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Intersecting holes. 56.7055 Section 56.7055... Piercing Drilling § 56.7055 Intersecting holes. Holes shall not be drilled where there is a danger of intersecting a misfired hole or a hole containing explosives blasting agents, or detonators. [56 FR 46508, Sept...

  1. UV-Vis-IR spectral complex refractive indices and optical properties of brown carbon aerosol from biomass burning

    Science.gov (United States)

    Sumlin, Benjamin J.; Heinson, Yuli W.; Shetty, Nishit; Pandey, Apoorva; Pattison, Robert S.; Baker, Stephen; Hao, Wei Min; Chakrabarty, Rajan K.

    2018-02-01

    Constraining the complex refractive indices, optical properties and size of brown carbon (BrC) aerosols is a vital endeavor for improving climate models and satellite retrieval algorithms. Smoldering wildfires are the largest source of primary BrC, and fuel parameters such as moisture content, source depth, geographic origin, and fuel packing density could influence the properties of the emitted aerosol. We measured in situ spectral (375-1047 nm) optical properties of BrC aerosols emitted from smoldering combustion of Boreal and Indonesian peatlands across a range of these fuel parameters. Inverse Lorenz-Mie algorithms used these optical measurements along with simultaneously measured particle size distributions to retrieve the aerosol complex refractive indices (m = n + iκ). Our results show that the real part n is constrained between 1.5 and 1.7 with no obvious functionality in wavelength (λ), moisture content, source depth, or geographic origin. With increasing λ from 375 to 532 nm, κ decreased from 0.014 to 0.003, with corresponding increase in single scattering albedo (SSA) from 0.93 to 0.99. The spectral variability of κ follows the Kramers-Kronig dispersion relation for a damped harmonic oscillator. For λ ≥ 532 nm, both κ and SSA showed no spectral dependency. We discuss differences between this study and previous work. The imaginary part κ was sensitive to changes in FPD, and we hypothesize mechanisms that might help explain this observation.

  2. In situ oil burning in the marshland environment : soil temperatures resulting from crude oil and diesel fuel burns

    International Nuclear Information System (INIS)

    Bryner, N.P.; Walton, W.D.; Twilley, W.H.; Roadarmel, G.; Mendelssohn, I.A.; Lin, Q.; Mullin, J.V.

    2001-01-01

    The unique challenge associated with oil spill cleanups in sensitive marsh environments was discussed. Mechanical recovery of crude or refined hydrocarbons in wetlands may cause more damage to the marsh than the oil itself. This study evaluated whether in situ burning of oiled marshlands would provide a less damaging alternative than mechanical recovery. This was done through a series of 6 crude oil and 5 diesel fuel burns conducted in a test tank to examine the impact of intentional burning of oil spilled in a wetlands environment. There are several factors which may influence how well such an environment would recover from an in situ oil burn, such as plant species, fuel type and load, water level, soil type, and burn duration. This paper focused on soil, air and water temperatures, as well as total heat fluxes that resulted when 3 plant species were exposed to full-scale in situ burns that were created by burning diesel fuel and crude oil. The soil temperatures were monitored during the test burn at three different soil/water elevations for 700 second burn exposures. A total of 184 plant sods were harvested from marshlands in southern Louisiana and were subjected to the burning fuel. They were instrumental in characterizing the thermal and chemical stress that occur during an in-situ burn. The plants were inserted into the test tanks at various water and soil depths. The results indicated that diesel fuel and crude oil burns produced similar soil temperature profiles at each of three plant sod elevations. Although in-situ burning did not appear to remediate oil that had penetrated into the soil, it did effectively remove floating oil from the water surface, thereby preventing it from potentially contaminating adjacent habitats and penetrating the soil when the water recedes. The regrowth and recovery of the plants will be described in a separate report. 25 refs., 7 tabs., 15 figs

  3. Lifshitz topological black holes

    International Nuclear Information System (INIS)

    Mann, R.B.

    2009-01-01

    I find a class of black hole solutions to a (3+1) dimensional theory gravity coupled to abelian gauge fields with negative cosmological constant that has been proposed as the dual theory to a Lifshitz theory describing critical phenomena in (2+1) dimensions. These black holes are all asymptotic to a Lifshitz fixed point geometry and depend on a single parameter that determines both their area (or size) and their charge. Most of the solutions are obtained numerically, but an exact solution is also obtained for a particular value of this parameter. The thermodynamic behaviour of large black holes is almost the same regardless of genus, but differs considerably for small black holes. Screening behaviour is exhibited in the dual theory for any genus, but the critical length at which it sets in is genus-dependent for small black holes.

  4. Epidemiology of burns undergoing hospitalization to the National Burns Unit in the Sultanate of Oman: a 25-year review.

    Science.gov (United States)

    Al-Shaqsi, Sultan; Al-Kashmiri, Ammar; Al-Bulushi, Taimoor

    2013-12-01

    The aim of this study was to describe the epidemiology of burns admitted to the National Burns Unit (NBU) in the Sultanate of Oman between 1987 and 2011. This is a retrospective review of burn patients admitted to Oman's National Burns Unit (NBU) between 1987 and 2011. The data extracted from the national burn registry. The study describes the admission rate by gender and age groups, occupation, causes of burns, time-to-admission, length of stay and in-hospital mortality of burns between 1987 and 2011. During a 25-year from 1987 to 2011, there were 3531 burn patients admitted to the National Burns Unit in Oman. The average admission rate to NBU is 7.02 per 100,000 persons per year. On average, males were more likely to be admitted to the NBU than females during the study period (P value Oman. Children are disproportionately over-represented in this study. Prevention programmes are urgently needed to address this "silent and costly epidemic." Copyright © 2013 Elsevier Ltd and ISBI. All rights reserved.

  5. The Parameters Controlling the Burning Efficiency of In-Situ Burning of Crude Oil on Water

    DEFF Research Database (Denmark)

    van Gelderen, Laurens; Jomaas, Grunde

    2017-01-01

    Parameters that control the burning efficiency of in-situ burning of crude oil on water were identified by studying the influence of the initial slick thickness, vaporization order, oil slick diameter, weathering state of the oil, heat losses to the water layer and heat flux to the fuel surface...... on the burning efficiency for light and heavy crude oils. These parameters were studied in several small scale and intermediate scale experimental setups. The results showed that the heat losses to the water layer increase with increasing burning time because the components in a crude oil evaporate from volatile...... to non-volatile. Due to the relatively low heat feedback (reradiation and convection, in kW/m2) to the fuel surface of small scale pool fires, as compared to large scale pool fires, these heat losses were shown to limit the burning efficiency in small scale experiments. By subjecting small scale crude...

  6. Black hole decay as geodesic motion

    International Nuclear Information System (INIS)

    Gupta, Kumar S.; Sen, Siddhartha

    2003-01-01

    We show that a formalism for analyzing the near-horizon conformal symmetry of Schwarzschild black holes using a scalar field probe is capable of describing black hole decay. The equation governing black hole decay can be identified as the geodesic equation in the space of black hole masses. This provides a novel geometric interpretation for the decay of black holes. Moreover, this approach predicts a precise correction term to the usual expression for the decay rate of black holes

  7. Fancy a cup of scald? - The role of hot beverage burns in paediatric burns admissions in Ireland.

    Science.gov (United States)

    McGuire, F; Hegarty, M; Jennings, P; Marsden, P; Smith, L

    2017-06-09

    Burns and scalds are preventable injuries in children that typically occur in the home. This study aimed to examine the role of hot beverage scalds in paediatric burn admissions in order to identify key target audiences for future safety strategies. Using the Hospital Inpatient Enquiry System (HIPE) a retrospective study of paediatric burn admissions in 2014 examined demographics, cause and severity of injury and location of occurrence. There were 233 paediatric discharges (age 0-18 yrs.) with a principal diagnosis of burn injury; 57% of these occurred in children under three years and 95% of these occurred in the home. Scalds caused 74% of burn injuries; hot beverages accounted for least 33% of these of which 77% were partial thickness and 73% were upper body burns. Effective hot beverage scald prevention strategies, targeted towards caregivers in the home, are required.

  8. Drilling miniature holes, Part III

    Energy Technology Data Exchange (ETDEWEB)

    Gillespie, L.K.

    1978-07-01

    Miniature components for precision electromechanical mechanisms such as switches, timers, and actuators typically require a number of small holes. Because of the precision required, the workpiece materials, and the geometry of the parts, most of these holes must be produced by conventional drilling techniques. The use of such techniques is tedious and often requires considerable trial and error to prevent drill breakage, minimize hole mislocation and variations in hole diameter. This study of eight commercial drill designs revealed that printed circuit board drills produced better locational and size repeatability than did other drills when centerdrilling was not used. Boring holes 1 mm in dia, or less, as a general rule did not improve hole location in brass or stainless steel. Hole locations of patterns of 0.66-mm holes can be maintained within 25.4-..mu..m diametral positional tolerance if setup misalignments can be eliminated. Size tolerances of +- 3.8 ..mu..m can be maintained under some conditions when drilling flat plates. While these levels of precision are possible with existing off-the-shelf drills, they may not be practical in many cases.

  9. Burn Injury Arise From Flying Balloon Toys

    Directory of Open Access Journals (Sweden)

    Yalcin Kulahci

    2007-08-01

    Full Text Available Many of peoples are faced minor or major burn injuries in their life. Even the most widespread burn cause is flame injuries, too different burn cause pointed out in literature like Acetylen burns. The cases which imply in literature, mostly causes from explosion of high pressure acetylene tube, metal oxygene patch flame or carbide lamp using from cave explorers. An interesting acetylene burn cause in Turkey was publised by the authors. This cases was to come into being from flying toy balloons flame. 80 person was injured from flying toy ballons flame in a meeting in 2002. Although this potential risks of acetylene, helium have not any of some risk. But helium was provided from other countries and have more price. The injuries which caused from acetylene burns like 1st -2nd degree burns. Consequently that was known helium is more avaliable for using in toy sector, and never cause burn injuries like this. [TAF Prev Med Bull. 2007; 6(4: 291-296

  10. Burn Pit Emissions Exposure and Respiratory and Cardiovascular Conditions Among Airborne Hazards and Open Burn Pit Registry Participants.

    Science.gov (United States)

    Liu, Jason; Lezama, Nicholas; Gasper, Joseph; Kawata, Jennifer; Morley, Sybil; Helmer, Drew; Ciminera, Paul

    2016-07-01

    The aim of this study was to determine how burn pit emissions exposure is associated with the incidence of respiratory and cardiovascular conditions. We examined the associations between assumed geographic and self-reported burn pit emissions exposure and respiratory and cardiovascular outcomes in participants of the Airborne Hazards and Open Burn Pit Registry. We found significant dose-response associations for higher risk of self-reported emphysema, chronic bronchitis, or chronic obstructive pulmonary disease with increased days of deployment within 2 miles of selected burn pits (P-trend = 0.01) and self-reported burn pit smoke exposure (P-trend = 0.0005). We found associations between burn pit emissions exposure and higher incidence of post-deployment self-reported respiratory and cardiovascular conditions, but these findings should be interpreted with caution because the surrogate measurements of burn pit emissions exposure in this analysis may not reflect individual exposure levels.

  11. Okanagan indoor wood burning appliance inventory survey

    International Nuclear Information System (INIS)

    2001-01-01

    A survey was conducted to determine the usage and nature of wood burning appliances used by residents in British Columbia's Okanagan region. The objective was to better understand this source of air quality concern and to facilitate strategic planning, guidelines and legislation. The survey also provides a baseline to track the effectiveness of any reduction strategies. It identifies the different types of wood burning appliances used in the community and presents residential options about potential bylaws to protect air quality. The receptivity of households to switch to more efficient wood burning appliances was also examined. The survey completes a portion of an overall emissions inventory for the Okanagan Valley. Environment Canada uses the particulate loading results to model the air quality in the airshed. Results showed that approximately 21 per cent of the households in the Okanagan use indoor wood burning appliances, and burn an average of 2.3 cords of wood each year. Only 11 per cent of the appliances are considered to have advanced burning technology. It is projected that the use of wood burning appliances in the Okanagan will increase by 5 to 7 per cent in the next 2 years. Most residents have good burning habits, but some improvements can still be made. Many residents are considering exchanging old wood burning appliances for clean burning technology appliances for environmental and health reasons. Most households would support a bylaw to control nuisance amounts of smoke from wood burning appliances. 20 tabs., 5 figs

  12. Burning mouth syndrome

    OpenAIRE

    Zakrzewska, Joanna; Buchanan, John A. G.

    2016-01-01

    Burning mouth syndrome is a debilitating medical condition affecting nearly 1.3 million of Americans. Its common features include a burning painful sensation in the mouth, often associated with dysgeusia and xerostomia, despite normal salivation. Classically, symptoms are better in the morning, worsen during the day and typically subside at night. Its etiology is largely multifactorial, and associated medical conditions may include gastrointestinal, urogenital, psychiatric, neurologic and met...

  13. Acceleration of black hole universe

    Science.gov (United States)

    Zhang, T. X.; Frederick, C.

    2014-01-01

    Recently, Zhang slightly modified the standard big bang theory and developed a new cosmological model called black hole universe, which is consistent with Mach's principle, governed by Einstein's general theory of relativity, and able to explain all observations of the universe. Previous studies accounted for the origin, structure, evolution, expansion, and cosmic microwave background radiation of the black hole universe, which grew from a star-like black hole with several solar masses through a supermassive black hole with billions of solar masses to the present state with hundred billion-trillions of solar masses by accreting ambient matter and merging with other black holes. This paper investigates acceleration of the black hole universe and provides an alternative explanation for the redshift and luminosity distance measurements of type Ia supernovae. The results indicate that the black hole universe accelerates its expansion when it accretes the ambient matter in an increasing rate. In other words, i.e., when the second-order derivative of the mass of the black hole universe with respect to the time is positive . For a constant deceleration parameter , we can perfectly explain the type Ia supernova measurements with the reduced chi-square to be very close to unity, χ red˜1.0012. The expansion and acceleration of black hole universe are driven by external energy.

  14. Super-horizon primordial black holes

    International Nuclear Information System (INIS)

    Harada, Tomohiro; Carr, B.J.

    2005-01-01

    We discuss a new class of solutions to the Einstein equations which describe a primordial black hole (PBH) in a flat Friedmann background. Such solutions arise if a Schwarzschild black hole is patched onto a Friedmann background via a transition region. They are possible providing the black hole event horizon is larger than the cosmological apparent horizon. Such solutions have a number of strange features. In particular, one has to define the black hole and cosmological horizons carefully and one then finds that the mass contained within the black hole event horizon decreases when the black hole is larger than the Friedmann cosmological apparent horizon, although its area always increases. These solutions involve two distinct future null infinities and are interpreted as the conversion of a white hole into a black hole. Although such solutions may not form from gravitational collapse in the same way as standard PBHs, there is nothing unphysical about them, since all energy and causality conditions are satisfied. Their conformal diagram is a natural amalgamation of the Kruskal diagram for the extended Schwarzschild solution and the conformal diagram for a black hole in a flat Friedmann background. In this paper, such solutions are obtained numerically for a spherically symmetric universe containing a massless scalar field, but it is likely that they exist for more general matter fields and less symmetric systems

  15. Burning mouth syndrome: An update

    Directory of Open Access Journals (Sweden)

    Vijay Kumar Ambaldhage

    2015-01-01

    Full Text Available Burning mouth syndrome (BMS is characterized by an oral burning sensation in the absence of any organic disorders of the oral cavity. Although the cause of BMS is not known, a complex association of biological and psychological factors has been identified, suggesting the existence of a multifactorial etiology. It is observed principally in middle-aged patients and postmenopausal women and is characterized by an intense burning type of pain, preferably on the tongue and in other areas of the oral mucosa. As the symptom of oral burning is seen in various pathological conditions, it is essential for a clinician to be aware of how to differentiate between symptom of oral burning and BMS. This article provides an overview of the literature on this syndrome with special reference to the etiological factors, clinical aspects, diagnostic criteria that should be followed and the therapeutic management with reference to the most recent studies.

  16. Maternal burn-out: an exploratory study.

    Science.gov (United States)

    Séjourné, N; Sanchez-Rodriguez, R; Leboullenger, A; Callahan, S

    2018-02-21

    Maternal burn-out is a psychological, emotional and physiological condition resulting from the accumulation of various stressors characterised by a moderate but also a chronic and repetitive dimension. Little research has focused on this syndrome. The current study aims to assess maternal burn-out rate and to identify factors associated with this state of exhaustion. 263 French mothers aged between 20 and 49 years answered five scales quantifying maternal burn-out, perceived social support, parental stress, depression and anxiety symptoms and history of postnatal depression. About 20% of mothers were affected by maternal burn-out. The main factors related to maternal burn-out were having a child perceived as difficult, history of postnatal depression, anxiety, satisfaction of a balance between professional and personal life and parental stress. This research shows the need for further work on maternal burn-out to better understand and prevent this syndrome.

  17. An X-ray view of the very faint black hole X-ray transient Swift J1357.2-0933 during its 2011 outburst

    NARCIS (Netherlands)

    Armas Padilla, M.; Wijnands, R.; Altamirano, D.; Méndez, M.; Miller, J. M.; Degenaar, N.

    We report on the X-ray spectral (using XMM-Newton data) and timing behaviour [using XMM-Newton and Rossi X-ray Timing Explorer (RXTE) data] of the very faint X-ray transient and black hole system Swift J1357.2-0933 during its 2011 outburst. The XMM-Newton X-ray spectrum of this source can be

  18. NASA Observatory Confirms Black Hole Limits

    Science.gov (United States)

    2005-02-01

    The very largest black holes reach a certain point and then grow no more, according to the best survey to date of black holes made with NASA's Chandra X-ray Observatory. Scientists have also discovered many previously hidden black holes that are well below their weight limit. These new results corroborate recent theoretical work about how black holes and galaxies grow. The biggest black holes, those with at least 100 million times the mass of the Sun, ate voraciously during the early Universe. Nearly all of them ran out of 'food' billions of years ago and went onto a forced starvation diet. Focus on Black Holes in the Chandra Deep Field North Focus on Black Holes in the Chandra Deep Field North On the other hand, black holes between about 10 and 100 million solar masses followed a more controlled eating plan. Because they took smaller portions of their meals of gas and dust, they continue growing today. "Our data show that some supermassive black holes seem to binge, while others prefer to graze", said Amy Barger of the University of Wisconsin in Madison and the University of Hawaii, lead author of the paper describing the results in the latest issue of The Astronomical Journal (Feb 2005). "We now understand better than ever before how supermassive black holes grow." One revelation is that there is a strong connection between the growth of black holes and the birth of stars. Previously, astronomers had done careful studies of the birthrate of stars in galaxies, but didn't know as much about the black holes at their centers. DSS Optical Image of Lockman Hole DSS Optical Image of Lockman Hole "These galaxies lose material into their central black holes at the same time that they make their stars," said Barger. "So whatever mechanism governs star formation in galaxies also governs black hole growth." Astronomers have made an accurate census of both the biggest, active black holes in the distance, and the relatively smaller, calmer ones closer by. Now, for the first

  19. Bacteriological profile of burn wound isolates in a burns center of a tertiary hospital

    Directory of Open Access Journals (Sweden)

    Amankwa Richcane

    2017-01-01

    Full Text Available Objective: To determine the bacteriological profile and antimicrobial susceptibility patterns of burn wound isolates.Methods: Swabs were taken from burn wound of patients admitted to Ward D2C and Burns Intensive Care Unit (BICU from December 2014 to November 2015. Samples were processed at the Microbiology Laboratory for identification and sensitivity. Bacteria isolated were identified using their morphological characteristics, Gram staining reaction and biochemical tests. The antimicrobial susceptibility testing was done using Kirby-Bauer disc diffusion method. Questionnaires were also administered to study participants to obtain information on demography, kind of first aid received, antibiotics received prior to culture and sensitivity.Results: A total of 86 patients comprising 45 patients from Ward D2C and 41 from BICU participated in the study. Males were 51(59.3% and females 35 (40.7%. Age of participants ranged from 0–56+ years. Pseudomonas aeruginosa was the commonest pathogen isolated 26(30.2%, followed by Pseudomonas spp. 21(24.4%, Escherichia coli 17(19.8%, Klebsiella spp. 12(14.0%. Coagulase negative Staphylococcus accounted for 2(2.3%. Overall prevalence of infection in the study was 90.7%.Conclusions: Burn wound infection continues to be a major challenge in burn centers. Regular surveillance of commonly identified pathogens in the ward and their antimicrobial susceptibility will guide proper empiric selection of antibiotics for management of burn wounds.

  20. Green's tensor calculations of plasmon resonances of single holes and hole pairs in thin gold films

    International Nuclear Information System (INIS)

    Alegret, Joan; Kaell, Mikael; Johansson, Peter

    2008-01-01

    We present numerical calculations of the plasmon properties of single-hole and hole-pair structures in optically thin gold films obtained with the Green's tensor formalism for stratified media. The method can be used to obtain the optical properties of a given hole system, without problems associated with the truncation of the infinite metal film. The calculations are compared with previously published experimental data and an excellent agreement is found. In particular, the calculations are shown to reproduce the evolution of the hole plasmon resonance spectrum as a function of hole diameter, film thickness and hole separation.

  1. Curvature invariant characterization of event horizons of four-dimensional black holes conformal to stationary black holes

    Science.gov (United States)

    McNutt, David D.

    2017-11-01

    We introduce three approaches to generate curvature invariants that transform covariantly under a conformal transformation of a four-dimensional spacetime. For any black hole conformally related to a stationary black hole, we show how a set of conformally covariant invariants can be combined to produce a conformally covariant invariant that detects the event horizon of the conformally related black hole. As an application we consider the rotating dynamical black holes conformally related to the Kerr-Newman-Unti-Tamburino-(anti)-de Sitter spacetimes and construct an invariant that detects the conformal Killing horizon along with a second invariant that detects the conformal stationary limit surface. In addition, we present necessary conditions for a dynamical black hole to be conformally related to a stationary black hole and apply these conditions to the ingoing Kerr-Vaidya and Vaidya black hole solutions to determine if they are conformally related to stationary black holes for particular choices of the mass function. While two of the three approaches cannot be generalized to higher dimensions, we discuss the existence of a conformally covariant invariant that will detect the event horizon for any higher dimensional black hole conformally related to a stationary black hole which admits at least two conformally covariant invariants, including all vacuum spacetimes.

  2. Pediatric burn rehabilitation: Philosophy and strategies

    Directory of Open Access Journals (Sweden)

    Shohei Ohgi

    2013-09-01

    Full Text Available Burn injuries are a huge public health issue for children throughout the world, with the majority occurring in developing countries. Burn injuries can leave a pediatric patient with severely debilitating and deforming contractures, which can lead to significant disability when left untreated. Rehabilitation is an essential and integral part of pediatric burn treatment. The aim of this article was to review the literature on pediatric burn rehabilitation from the Medline, CINAHL, and Web of Science databases. An attempt has been made to present the basic aspects of burn rehabilitation, provide practical information, and discuss the goals and conceptualization of rehabilitation as well as the development of rehabilitation philosophy and strategies.

  3. Statistical mechanics of black holes

    International Nuclear Information System (INIS)

    Harms, B.; Leblanc, Y.

    1992-01-01

    We analyze the statistical mechanics of a gas of neutral and charged black holes. The microcanonical ensemble is the only possible approach to this system, and the equilibrium configuration is the one for which most of the energy is carried by a single black hole. Schwarzschild black holes are found to obey the statistical bootstrap condition. In all cases, the microcanonical temperature is identical to the Hawking temperature of the most massive black hole in the gas. U(1) charges in general break the bootstrap property. The problems of black-hole decay and of quantum coherence are also addressed

  4. Study of high energy emissions from stellar mass accreting holes

    International Nuclear Information System (INIS)

    Cadolle-Bel, Marion

    2006-01-01

    The present work is dedicated to the study of various X-ray binary Systems harbouring accreting stellar mass black holes (or candidates) associated in X-ray binary Systems mainly through the spectral and timing properties of the high energy 3 keV"-"1 MeV emission, sometimes completed by observations performed in radio, near-infrared and optical. The first part is devoted to accretion physics phenomena and the challenges of understanding the X-ray/gamma emission produced with the modeling of such high energy processes. Then I will define in a second part the instruments on board INTEGRAL and the way coded masked aperture is employed. In a third part, I will develop the standard data reduction analysis and my own contribution in improving the usual software before detailing the specific informatics tools I have developed for my own analysis. In the fourth part I will turn towards the deep analysis and interpretations I have performed on several black hole X-ray binary Systems chosen properly: the persistent black hole source Cygnus X-1 which has been studied since several years and surprised us by a high-energy excess detected; two new transient sources which provide interesting information, XTE J1720-318 located in the galactic bulge and SWIFT J1753.5-0127, probably situated in the halo. I will also detail my work on H 1743-322, recently identified by INTEGRAL as the HEAO source discovered in 1977, and on three (almost) persistent micro-quasars with superluminal jets, 1E 1740.7-2942, GRS 1758-258 and GRS 1915+105. I will analyze for each source spectral parameter evolutions and their links with each other during state transitions. I will then discuss the presence of two different X/gamma-ray emitting media with a relatively changing geometry. While establishing a cyclic order for the different variability classes of GRS 1915+105 observed during ten years, I will propose an interpretation for such behaviour, compatible with the theoretical predictions of the

  5. Room-Temperature Dephasing in InAs Quantum Dots

    DEFF Research Database (Denmark)

    Borri, Paola; Langbein, Wolfgang; Mørk, Jesper

    2000-01-01

    The room temperature dephasing in InAs/InGaAs/GaAs self-assembled quantum dots, embedded in a waveguide for laser applications, is measured using two independent methods: spectral hole burning and four-wave mixing. Without the application of bias current for electrical carrier injection......, a dephasing time of ~260 fs, weakly dependent on the optical excitation density, is found and attributed to phonon interaction. The application of bias current, leading to population inversion in the dot ground state and optical gain, strongly decreases the dephasing time to less than 50 fs, likely due...

  6. Subpicosecond gain dynamics in GaAlAs laser diodes

    Energy Technology Data Exchange (ETDEWEB)

    Kesler, M.P.; Ippen, E.P.

    1987-11-30

    Ultrafast gain dynamics in GaAlAs diode amplifiers have been studied using 100 fs optical pulses. Pulse propagation through the amplifier resulted in temporal broadening and pulse shaping due to both gain saturation and material dispersion. Pump-probe experiments indicate the presence of two processes contributing to the gain dynamics but give no evidence of spectral hole burning. A dynamic carrier heating model is presented to explain all of the observed gain nonlinearities, and the implications of our results on the dynamic response of laser diodes are discussed.

  7. High speed all optical logic gates based on quantum dot semiconductor optical amplifiers.

    Science.gov (United States)

    Ma, Shaozhen; Chen, Zhe; Sun, Hongzhi; Dutta, Niloy K

    2010-03-29

    A scheme to realize all-optical Boolean logic functions AND, XOR and NOT using semiconductor optical amplifiers with quantum-dot active layers is studied. nonlinear dynamics including carrier heating and spectral hole-burning are taken into account together with the rate equations scheme. Results show with QD excited state and wetting layer serving as dual-reservoir of carriers, as well as the ultra fast carrier relaxation of the QD device, this scheme is suitable for high speed Boolean logic operations. Logic operation can be carried out up to speed of 250 Gb/s.

  8. 49 CFR 195.226 - Welding: Arc burns.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Welding: Arc burns. 195.226 Section 195.226 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Construction § 195.226 Welding: Arc burns. (a) Each arc burn must be repaired. (b) An arc burn may...

  9. DIFFERENTIATING PERIMORTEM AND POSTMORTEM BURNING

    Directory of Open Access Journals (Sweden)

    Brahmaji Master

    2015-01-01

    Full Text Available One of the most challenging cases in forensic medicine is ascertaining the cause of death of burnt bodies under suspicious circumstances. The key questions that arise at the time of investigation include: 1  Was the person alive or dead prior to fire accident?  Did the victim die because of burn?  If death was not related to burns, could burns play a role in causing death?  Were the burns sustained accidentally, did the person commit suicide or was the person murdered?  Are the circumstances suggesting an attempt to conceal crime?  How was the fire started?  How was the victim identified?  In case of mass fatalities, who died first? Postmortem burning of corpses is supposed to be one of the ways to hide a crime. Differentiating the actual cause of death in burn patients is therefore important. Medical examiners usually focus on the defining the changes that occur in tissues while forensic anthropologists deal with the changes related to the bone with or without any the influence of other tissues. Under the circumstances of fire, differentiating the perimortem trauma from that of postmortem cause of bone fractures is vital in determining the cause and motive of death

  10. Comparison of heat transfer and soil impacts of air curtain burner burning and slash pile burning

    Science.gov (United States)

    Woongsoon Jang; Deborah S. Page-Dumroese; Han-Sup Han

    2017-01-01

    We measured soil heating and subsequent changes in soil properties between two forest residue disposal methods: slash pile burning (SPB) and air curtain burner (ACB). The ACB consumes fuels more efficiently and safely via blowing air into a burning container. Five burning trials with different fuel sizes were implemented in northern California, USA. Soil temperature...

  11. Pediatric burn wound impetigo after grafting.

    Science.gov (United States)

    Aikins, Kimberly; Prasad, Narayan; Menon, Seema; Harvey, John G; Holland, Andrew J A

    2015-01-01

    Modern burn care techniques have reduced the risk of infection of the acute burn wound, resulting in more rapid healing and a lower incidence of graft loss. Secondary breakdown may still occur. The loss of epithelium in association with multifocal superficial abscesses and ulceration has been termed burns impetigo. This may result in considerable morbidity and require prolonged treatment. The events preceding development, the impact on the patient, and the ideal treatment appear unclear and poorly reported. In 5 years, between 2006 and 2011, 406 pediatric burns were treated with skin grafts, with 7% developing burns impetigo. Time to resolution ranged from 5 to 241 days: the mean time to complete healing was greatest with conservative management (96 days), followed by antibacterial dressings (37 days), oral antibiotics (36 days), topical steroids (16 days), and oral antibiotics in combination with topical steroids (13.5 days). Burns impetigo resulted in significant morbidity, requiring multiple visits to the treatment center and prolonged symptoms. Delay in diagnosis and treatment resulted in worse outcomes. Prompt consideration of burns impetigo should occur when postgraft patients present with suggestive clinical signs and treatment with oral antibiotics plus topical steroids should be considered.

  12. [Burns, new challenges to take on].

    Science.gov (United States)

    Galí-Llàcer, Rosa; Sena-Fernández, Beatriz; Leyva-Moral, Juan Manuel

    2009-04-01

    This article concerns a transversal descriptive study which shows the characteristics of burns treated in a Primary Health Care Center in an urban environment in Barcelona from 19 July 2005 unti 11 August 2007 (N=93). Patients younger than 15 were excluded from this study. 88% (82; CI of 95% 81,47-94,59) of the burns treated were caused by a thermal agent. Kitchen cooking oil ranks first as the cause of burns (24; 27%, CI of 95% 17,99-36,01). 70% of the burns studied had signs of superficial skin damage (65, CI of 95% 60,70-79,30). 61% (57; CI of 95% 51,70-70,30) of these burns were located on upper extremities The average recorded body surface burned was 0.0076% (median = 0,005%, range = 0,0001-0,5000%). The greatest number of wounds were observed among men aged 31 to 45 (17%; 16; CI of 95% 9,38-24,62). Educational health programs which focus on prevention of, and first aid care for, burns are needed. Studies like this one may prove useful when starting preventive or educational strategies.

  13. Burning characteristics of microcellular combustible objects

    Directory of Open Access Journals (Sweden)

    Wei-tao Yang

    2014-06-01

    Full Text Available Microcellular combustible objects for application of combustible case, caseless ammunition or combustible detonator-holding tubes are fabricated through one-step foaming process, in which supercritical CO2 is used as foaming agent. The formulations consist of inert polymer binder and ultra fine RDX. For the inner porous structures of microcellular combustible objects, the cell sizes present a unimodal or bimodal distribution by adjusting the foaming conditions. Closed bomb test is to investigate the influence of both porous structure style and RDX content on burning behavior. The sample with bimodal distribution of cell sizes burns faster than that with unimodal distribution, and the concentration of RDX can influence the burning characteristics in a positive manner. In addition, the translation of laminar burning to convective burning is determined by burning rate versus pressure curves of samples at two different loading densities, and the resulting transition pressure is 30 MPa. Moreover, the samples with bigger sample size present higher burning rate, resulting in providing deeper convective depth. Dynamic vivacity of samples is also studied. The results show that the vivacity increases with RDX content and varies with inner structure.

  14. [Burns in adolescents].

    Science.gov (United States)

    Ortiz Rodríguez, R; Domínguez Amillo, E; Soto Beauregard, C; Díaz González, M; López Gutiérrez, J C; Ros Mar, Z; Tovar Larrucea, J A

    2012-04-01

    The aim of this study was to know the epidemiology of burns in teenagers. Burn patients over 11 years old admitted in our Institution in the last 10 years were included. Etiology, burn size, hospital stay, quirurgical interventions and long term sequelae were registered. One thousand and eight patients were admitted, 89 were over 11 years (8.8%), 70.7% were boys and 29.3% girls. Fire was the principal agent in 58 cases (65.1%), due to fireworks in 13 (22.4%), alcohol in 7 (12%), explosion of flammable containers (spray) in 4 (6.8%) and gasoline in 3 (5.2%). Fireworks injuries and spray explosions affected face and hand in 88% cases. The median hospital stay was 8 days after admission (1 to 90). 83.1% required surgical treatment with mean of 1.8 +/- 1.4 interventions and 21.3% had long-term sequelaes that required at least one surgical intervention. Fire is the main cause of burns in adolescents. Fireworks injuries represented a quarter of that lesions, and highlights paint spray explosions as new causative agents. Considering the high morbidity in this age group, with permanent functional and aesthetic sequelae, prevention campaigns are needed to reduce such accidents.

  15. Regular black hole in three dimensions

    OpenAIRE

    Myung, Yun Soo; Yoon, Myungseok

    2008-01-01

    We find a new black hole in three dimensional anti-de Sitter space by introducing an anisotropic perfect fluid inspired by the noncommutative black hole. This is a regular black hole with two horizons. We compare thermodynamics of this black hole with that of non-rotating BTZ black hole. The first-law of thermodynamics is not compatible with the Bekenstein-Hawking entropy.

  16. Impact of Work-Related Burn Injury on Social Reintegration Outcomes: A Life Impact Burn Recovery Evaluation (LIBRE) Study.

    Science.gov (United States)

    Schneider, Jeffrey C; Shie, Vivian L; Espinoza, Leda F; Shapiro, Gabriel D; Lee, Austin; Acton, Amy; Marino, Molly; Jette, Alan; Kazis, Lewis E; Ryan, Colleen M

    2017-11-26

    To examine differences in long-term social reintegration outcomes for burn survivors with and without work-related injuries. Cross-sectional survey. Community-dwelling burn survivors. Burn survivors (N=601) aged ≥18 years with injuries to ≥5% total body surface area or burns to critical areas (hands, feet, face, or genitals). Not applicable. The Life Impact Burn Recovery Evaluation Profile was used to examine the following previously validated 6 scale scores of social participation: Family and Friends, Social Interactions, Social Activities, Work and Employment, Romantic Relationships, and Sexual Relationships. Older participants, those who were married, and men were more likely to be burned at work (Preintegration outcomes than those without work-related injuries. Identification of those at higher risk for work reintegration challenges after burn injury may enable survivors, providers, employers, and insurers to better use appropriate resources to promote and target optimal employment outcomes. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  17. Burn prevention in Zambia: a targeted epidemiological approach.

    Science.gov (United States)

    Heard, Jason P; Latenser, Barbara A; Liao, Junlin

    2013-01-01

    The aim of this study is to assess primary burn prevention knowledge in a rural Zambian population that is disproportionately burdened by burn injuries. A 10-question survey was completed by youths, and a 15-question survey was completed by adults. The survey was available in both English and Nyanja. The surveys were designed to test their knowledge in common causes, first aid, and emergency measures regarding burn injuries. Logistic regression analysis was used to explore relationships between burn knowledge, age, school, and socioeconomic variables. A burn prevention coloring book, based on previous local epidemiological data, was also distributed to 800 school age youths. Five hundred fifty youths and 39 adults completed the survey. The most significant results show knowledge deficits in common causes of burns, first aid treatment of a burn injury, and what to do in the event of clothing catching fire. Younger children were more likely to do worse than older children. The adults performed better than the youths, but still lack fundamental burn prevention and treatment knowledge. Primary burn prevention data from the youths and adults surveyed demonstrate a clear need for burn prevention and treatment education in this population. In a country where effective and sustainable burn care is lacking, burn prevention may be a better investment to reduce burn injury than large investments in healthcare resources.

  18. Accelerant-related burns and drug abuse: Challenging combination.

    Science.gov (United States)

    Leung, Leslie T F; Papp, Anthony

    2018-05-01

    Accelerants are flammable substances that may cause explosion when added to existing fires. The relationships between drug abuse and accelerant-related burns are not well elucidated in the literature. Of these burns, a portion is related to drug manufacturing, which have been shown to be associated with increased burn complications. 1) To evaluate the demographics and clinical outcomes of accelerant-related burns in a Provincial Burn Centre. 2) To compare the clinical outcomes with a control group of non-accelerant related burns. 3) To analyze a subgroup of patients with history of drug abuse and drug manufacturing. Retrospective case control study. Patient data associated with accelerant-related burns from 2009 to 2014 were obtained from the British Columbia Burn Registry. These patients were compared with a control group of non-accelerant related burns. Clinical outcomes that were evaluated include inhalational injury, ICU length of stay, ventilator support, surgeries needed, and burn complications. Chi-square test was used to evaluate categorical data and Student's t-test was used to evaluate mean quantitative data with the p value set at 0.05. A logistic regression model was used to evaluate factors affecting burn complications. Accelerant-related burns represented 28.2% of all burn admissions (N=532) from 2009 to 2014. The accelerant group had higher percentage of patients with history of drug abuse and was associated with higher TBSA burns, ventilator support, ICU stay and pneumonia rates compared to the non-accelerant group. Within the accelerant group, there was no difference in clinical outcomes amongst people with or without history of drug abuse. Four cases were associated with methamphetamine manufacturing, all of which underwent ICU stay and ventilator support. Accelerant-related burns cause significant burden to the burn center. A significant proportion of these patients have history of drug abuse. Copyright © 2017 Elsevier Ltd and ISBI. All rights

  19. Black hole levitron

    NARCIS (Netherlands)

    Arsiwalla, X.D.; Verlinde, E.P.

    2010-01-01

    We study the problem of spatially stabilizing four dimensional extremal black holes in background electric/magnetic fields. Whilst looking for stationary stable solutions describing black holes placed in external fields we find that taking a continuum limit of Denef et al.’s multicenter

  20. Childhood burns in south eastern Nigeria.

    Science.gov (United States)

    Archibong, A E; Antia, U E; Udosen, J

    1997-06-01

    In a ten year retrospective study of burns in children in University of Calabar Teaching Hospital (UCTH), Calabar, the main causes were hot water, hot soup or oil (56.6%) involving children mostly in the one to three year age group. The relative safety of the home environment seen in other forms of paediatric trauma is not observed in burns in children. A changing pattern of burns in children has emerged within the region with naked flames/bush fire coming second and affecting 22.7% of the children. Chemical burns hitherto a rare occurrence is now frequent because of the storage of caustic soda and acids in living rooms by soap making parents. Burns affecting the perineum, axilla and buttocks are difficult to keep clean and frequently lead to infections, with associated increased morbidity. Causes of childhood burns are largely preventable requiring active social/medical education and public enlightenment campaigns on the various methods of prevention.