WorldWideScience

Sample records for narrow single peak

  1. Generation of 130 W narrow-linewidth high-peak-power picosecond pulses directly from a compact Yb-doped single-stage fiber amplifier

    Science.gov (United States)

    Qi, Yaoyao; Yu, Haijuan; Zhang, Jingyuan; Wang, Lei; Zhang, Ling; Lin, Xuechun

    2015-09-01

    We report a compact, 130-W single-stage master oscillator power amplifier with a high peak power of 51.3 kW and a narrow spectral linewidth of 0.1 nm. The seed source is a single-mode, passively mode-locked solid-state laser at 1064 nm with an average power of 2 W. At a repetition rate of 73.5 MHz, the pulse duration is 30 ps. After amplification, it stretches to 34.5 ps. The experiment enables the optical-to-optical conversion efficiency to reach 75%. To the best of our knowledge, this is the first report of such a high-power, narrow spectral linewidth, high peak power picosecond-pulse fiber amplifier based on a continuous-wave, mode-locked solid-state seeding laser. No amplified spontaneous emission and stimulated Raman scattering were observed when the pump was increased.

  2. Generation of narrow peaks in spectroscopy of charged particles

    Science.gov (United States)

    Dubbers, Dirk; Schmidt, Ulrich

    2016-11-01

    In spectroscopy of charged particles, narrow peaks may appear in continuous spectra if magnetic transport of the particles is involved. These artefacts, which so far have escaped the attention of investigators, can develop whenever geometric detection efficiency is less than 100%. As such peaks may be misinterpreted as new physics, their generation is investigated, both analytically and experimentally, for various detector configurations, including those used in searches for the spontaneous decay of the vacuum in heavy-ion collisions.

  3. Narrow linewidth picosecond UV pulsed laser with mega-watt peak power.

    Science.gov (United States)

    Huang, Chunning; Deibele, Craig; Liu, Yun

    2013-04-08

    We demonstrate a master oscillator power amplifier (MOPA) burst mode laser system that generates 66 ps/402.5 MHz pulses with mega-watt peak power at 355 nm. The seed laser consists of a single frequency fiber laser (linewidth picosecond pulse generator, and a fiber based preamplifier. A very high extinction ratio (45 dB) has been achieved by using an adaptive bias control of the EOM. The multi-stage Nd:YAG amplifier system allows a uniformly temporal shaping of the macropulse with a tunable pulse duration. The light output from the amplifier is converted to 355 nm, and over 1 MW peak power is obtained when the laser is operating in a 5-μs/10-Hz macropulse mode. The laser output has a transform-limited spectrum with a very narrow linewidth of individual longitudinal modes. The immediate application of the laser system is the laser-assisted hydrogen ion beam stripping for the Spallation Neutron Source (SNS).

  4. Social learning solves the problem of narrow-peaked search landscapes: experimental evidence in humans.

    Science.gov (United States)

    Acerbi, Alberto; Tennie, Claudio; Mesoudi, Alex

    2016-09-01

    The extensive use of social learning is considered a major reason for the ecological success of humans. Theoretical considerations, models and experiments have explored the evolutionary basis of social learning, showing the conditions under which learning from others is more adaptive than individual learning. Here we present an extension of a previous experimental set-up, in which individuals go on simulated 'hunts' and their success depends on the features of a 'virtual arrowhead' they design. Individuals can modify their arrowhead either by individual trial and error or by copying others. We study how, in a multimodal adaptive landscape, the smoothness of the peaks influences learning. We compare narrow peaks, in which solutions close to optima do not provide useful feedback to individuals, to wide peaks, where smooth landscapes allow an effective hill-climbing individual learning strategy. We show that individual learning is more difficult in narrow-peaked landscapes, but that social learners perform almost equally well in both narrow- and wide-peaked search spaces. There was a weak trend for more copying in the narrow than wide condition, although as in previous experiments social information was generally underutilized. Our results highlight the importance of tasks' design space when studying the adaptiveness of high-fidelity social learning.

  5. A High Fraction of Double-peaked Narrow Emission Lines in Powerful Active Galactic Nuclei

    CERN Document Server

    Lyu, Yang

    2016-01-01

    One percent of redshift z~0.1 Active Galactic Nuclei (AGNs) show velocity splitting of a few hundred km/s in the narrow emission lines in spatially integrated spectra. Such line profiles have been found to arise from the bulk motion of ionized gas clouds associated with galactic-scale outflows, merging pairs of galaxies each harboring a supermassive black hole (SMBH), and/or galactic-scale disk rotation. It remains unclear, however, how the frequency of narrow-line velocity splitting may depend on AGN luminosity. Here we study the correlation between the fraction of Type 2 AGNs with double-peaked narrow emission lines and AGN luminosity as indicated by [O III]5007 emission-line luminosity L_[O III]. We combine the sample of Liu et al. (2010) at z~0.1 with a new sample of 178 Type 2 AGNs with double-peaked [O III] emission lines at z~0.5. We select the new sample from a parent sample of 2089 Type 2 AGNs from the SDSS-III/Baryon Oscillation Spectroscopic Survey. We find a statistically significant (~4.2\\sigma) ...

  6. The host galaxies and narrow-line regions of four double-peaked [OIII] AGNs

    Energy Technology Data Exchange (ETDEWEB)

    Villforth, Carolin; Hamann, Fred [Department of Astronomy, University of Florida, 32611 Gainesville, FL (United States)

    2015-03-01

    Major gas-rich mergers of galaxies are expected to play an important role in triggering and fueling luminous active galactic nuclei (AGNs). The mechanism of AGN fueling during mergers, however, remains poorly understood. We present deep multi-band (u/r/z) imaging and long-slit spectroscopy of four double-peaked [OIII] emitting AGNs. This class of object is likely associated with either kiloparsec-separated binary AGNs or final stage major mergers, although AGNs with complex narrow-line regions (NLRs) are known contaminants. Such objects are of interest since they represent the onset of AGN activity during the merger process. Three of the four double-peaked [OIII] emitters studied have been confirmed as major mergers using near-infrared imaging and one is a confirmed X-ray binary AGN. All AGNs are luminous, radio-quiet to radio-intermediate, and have redshifts of 0.1

  7. Single Frequency Narrow Linewidth 2 Micron Laser Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA needs narrow linewidth lasers in the 1.5 or 2 micron wavelength regime for coherent Lidar applications. The laser should be tunable by several nm and frequency...

  8. Error Thresholds in Single-Peak Gaussian Distributed Fitness Landscapes

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on the Eigen and Crow-Kimura models with a single-peak fitness landscape, we propose the fitness values of all sequence types to be Gaussian distributed random variables to incorporate the effects of the fluctuations of the fitness landscapes (noise of environments) and investigate the concentration distribution and error threshold of quasispecies by performing an ensemble average within this theoretical framework. We find that a small fluctuation of the fitness landscape causes only a slight change in the concentration distribution and error threshold, which implies that the error threshold is stable against small perturbations. However, for a sizable fluctuation, quite different from the previous deterministic models, our statistical results show that the transition from quasispecies to error catastrophe is not so sharp, indicating that the error threshold is located within a certain range and has a shift toward a larger value. Our results are qualitatively in agreement with the experimental data and provide a new implication for antiviral strategies.

  9. Tunable Narrow Linewidth, Low Noise 2.05 Micron Single Frequency Seeder Laser Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose an all-fiber based 2.05-micron single frequency, narrow linewidth seeder laser with 10 nm tuning range and 5GHz frequency modulation for next generation...

  10. Tunable Narrow Linewidth, Low Noise 2.05 Micron Single Frequency Seeder Laser Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose an all-fiber based 2.05-micron single frequency, narrow linewidth seeder laser with 10 nm tuning range and 5GHz frequency modulation for next generation...

  11. Error Thresholds in Single-Peak Gaussian Distributed Fitness Landscapes

    Science.gov (United States)

    Feng, Xiao-Li; Gu, Jian-Zhong; Li, Yu-Xiao; Zhuo, Yi-Zhong

    2007-10-01

    Based on the Eigen and Crow-Kimura models with a single-peak fitness landscape, we propose the fitness values of all sequence types to be Gaussian distributed random variables to incorporate the effects of the fluctuations of the fitness landscapes (noise of environments) and investigate the concentration distribution and error threshold of quasispecies by performing an ensemble average within this theoretical framework. We find that a small fluctuation of the fitness landscape causes only a slight change in the concentration distribution and error threshold, which implies that the error threshold is stable against small perturbations. However, for a sizable fluctuation, quite different from the previous deterministic models, our statistical results show that the transition from quasi-species to error catastrophe is not so sharp, indicating that the error threshold is located within a certain range and has a shift toward a larger value. Our results are qualitatively in agreement with the experimental data and provide a new implication for antiviral strategies.

  12. Variable Depth Bragg Peak Method for Single Event Effects Testing

    Science.gov (United States)

    Buchner, S.; Kanyogoro, N.; Foster, C.; O'Neill, P.

    2011-01-01

    Traditionally, accelerator SEE testing is accomplished by removing the tops of packages so that the IC chips are accessible to heavy ions. However, ICs in some advanced packages cannot be de-lidded so a different approach is used that involves grinding and/or chemically etching away part of the package and the chip from the back side. The parts are then tested from the back side with ions having sufficient range to reach the sensitive volume. More recently, the entire silicon substrate in an SOI/SRAM was removed, making it possible to use low-energy ions with shorter ranges. Where removal of part of the package is not possible, facilities at Michigan State, NASA Space Radiation Laboratory, GANIL (France) and GSI (Germany) offer high-energy heavy ions with long ranges so that the ions can reach the devices' sensitive volumes without much change in the LET. Unfortunately, a run will typically involve only one ion species having a single energy and LET due to the long time it takes to tune a new energy. The Variable Depth Bragg Peak (VDBP) method is similar to the above method in that it involves the use of high-energy heavy ions that are able to pass through the packaging material and reach the device, obviating the need to remove the package. However, the method provides a broad range of LETs from a single ion by inserting degraders in the beam that modify the ion energy and, therefore, the LET. The crux of the method involves establishing a fiduciary point for degrader thickness, i.e., where the Bragg peak is located precisely at the sensitive volume in the device, for which the measured SEU cross-section and the ion LET are both also maxima and can be calculated using a Monte-Carlo program, TRIM. Once the fiduciary point has been established, calibrated high density polyethylene (HDPE) degraders are inserted into or removed from the beam to vary the ion LET at the device in a known manner. After each change of degrader thickness, the SEU cross-section is measured

  13. Narrow linewidth single laser source system for onboard atom interferometry

    CERN Document Server

    Theron, Fabien; Renon, Geoffrey; Bidel, Yannick; Zahzam, Nassim; Cadoret, Malo; Bresson, Alexandre

    2014-01-01

    We present an original compact and robust laser system for atom interferometry based on a frequency-doubled telecom laser. Thanks to an original stabilization architecture on a saturated absorption, we obtain a frequency agile laser system allowing fast tuning of the laser frequency over 1 GHz in few ms using only a single laser source. The different laser frequencies used for atom interferometry are created by changing dynamically the frequency of the laser and by creating sidebands using a phase modulator. We take advantage of the maturity of fiber telecom technology to reduce the number of free-space optical components, which are intrinsically less stable, and to make the setup compact, much less sensitive to vibrations and thermal fluctuations. This source provides spectral linewidth below 2.5 kHz required for precision atom interferometry, and particularly for an high performance atomic inertial sensor.

  14. Narrow linewidth single laser source system for onboard atom interferometry

    Science.gov (United States)

    Theron, Fabien; Carraz, Olivier; Renon, Geoffrey; Zahzam, Nassim; Bidel, Yannick; Cadoret, Malo; Bresson, Alexandre

    2015-01-01

    A compact and robust laser system for atom interferometry based on a frequency-doubled telecom laser is presented. Thanks to the original stabilization architecture on a saturated absorption setup, we obtain a frequency agile laser system allowing fast tuning of the laser frequency over 1 GHz in few ms using a single laser source. The different laser frequencies used for atom interferometry are generated by changing dynamically the frequency of the laser and by creating sidebands using a phase modulator. A laser system for Rubidium 87 atom interferometry using only one laser source based on a frequency-doubled telecom fiber bench is then built. We take advantage of the maturity of fiber telecom technology to reduce the number of free-space optical components (which are intrinsically less stable) and to make the setup compact and much less sensitive to vibrations and thermal fluctuations. This source provides spectral linewidth below 2.5 kHz, which is required for precision atom interferometry and particularly for a high performance atomic inertial sensor.

  15. THE ORIGIN OF DOUBLE-PEAKED NARROW LINES IN ACTIVE GALACTIC NUCLEI. I. VERY LARGE ARRAY DETECTIONS OF DUAL AGNs AND AGN OUTFLOWS

    Energy Technology Data Exchange (ETDEWEB)

    Müller-Sánchez, F.; Comerford, J. M.; Nevin, R.; Barrows, R. S. [Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 (United States); Cooper, M. C. [Center for Cosmology, Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States); Greene, J. E. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

    2015-11-10

    We have examined a subset of 18 active galactic nuclei (AGNs) drawn from a sample of 81 galaxies that possess double-peaked narrow optical emission line spectra in the Sloan Digital Sky Survey, have 2 optical AGN emission components separated by >0.″2, and are detected in the Faint Images of the Radio Sky at Twenty-centimeters survey. Without follow-up observations, the sources of the double-peaked narrow emission lines are uncertain, and may be produced by kiloparsec-scale separation dual active supermassive black holes, AGN outflows, or disk rotation. In this work, we propose a new methodology to characterize double-peaked narrow emission line galaxies based on optical long-slit spectroscopy and high-resolution multi-band Very Large Array observations. The nature of the radio emission in the sample galaxies is varied. Of the 18 galaxies, we detect 2 compact flat-spectrum radio cores with projected spatial separations on the sky between 0.6 and 1.6 kpc in 3 galaxies: J1023+3243, J1158+3231, and J1623+0808. The two radio sources are spatially coincident with the two optical components of ionized gas with AGN-like line ratios, which confirms the presence of dual AGNs in these three galaxies. Dual AGNs account for only ∼15% (3/18) of the double-peaked AGNs in our sample. Gas kinematics produce ∼75% (13/18) of the double-peaked narrow emission lines, distributed in the following way: seven AGN wind-driven outflows, five radio-jet driven outflows, and one rotating narrow-line region. The remaining 10% (2/18) are ambiguous cases. Our method demonstrates the power of spatially resolved spectroscopy and high-resolution radio observations for the identification of AGN outflows and AGN pairs with angular separations as small as 0.″18.

  16. Differential-phase-shift quantum key distribution using heralded narrow-band single photons.

    Science.gov (United States)

    Liu, Chang; Zhang, Shanchao; Zhao, Luwei; Chen, Peng; Fung, C-H F; Chau, H F; Loy, M M T; Du, Shengwang

    2013-04-22

    We demonstrate the first proof of principle differential phase shift (DPS) quantum key distribution (QKD) using narrow-band heralded single photons with amplitude-phase modulations. In the 3-pulse case, we obtain a quantum bit error rate (QBER) as low as 3.06% which meets the unconditional security requirement. As we increase the pulse number up to 15, the key creation efficiency approaches 93.4%, but with a cost of increasing the QBER. Our result suggests that narrow-band single photons maybe a promising source for the DPS-QKD protocol.

  17. Self Q-switched characteristic based on single longitudinal DBR erbium-doped fiber laser with narrow linewidth pulse output

    Science.gov (United States)

    Lyu, Chengang; Zhang, Shuai; Zhang, Xugeng; Gao, Jiale; Jie, Jin

    2017-09-01

    The self Q-switched characteristic of the single longitudinal-mode distributed Bragg reflector (DBR) erbium-doped fiber laser (EDFL) with narrow linewidth pulse output is demonstrated without any extra saturable absorber or electro-optic and acoustic-optic modulator, and it is provided with a simpler structure and lower cost. The proposed pulse laser operates at approximately 1550.33 nm with a 20 dB bandwidth of 0.56 nm and signal-to-noise ratio of about 55 dB. By increasing the 980 nm pump power from 80-330 mW, the repetition rate of the output pulse increases from 73.53-147.1 kHz while the pulse width decreases from 1.4-0.2 µs, which shows the feature of the narrow linewidth ideally. The maximum pulse energy of 0.379 nJ and peak power of 1897.2 µW are generated with a repetition rate and pulse width of 147.1 kHz and 0.2 µs, respectively. The result shows that the self Q-switched pulse of the DBR EDFL is obviously dependent on the applied pump power and possesses the characteristic of the single longitudinal mode and the narrow linewidth, offering potential utilization in industrial processing and scientific research.

  18. The Origin of Double-Peaked Narrow Lines in Active Galactic Nuclei I: Very Large Array Detections of Dual AGNs and AGN Outflows

    CERN Document Server

    Müller-Sanchez, Francisco; Nevin, Rebecca; Barrows, R Scott; Cooper, Michael C; Greene, Jenny E

    2015-01-01

    We have examined a subset of 18 active galactic nuclei (AGNs) drawn from a sample of 81 galaxies that possess double-peaked narrow optical emission line spectra in the Sloan Digital Sky Survey, have two optical AGN emission components separated by >0.2", and are detected in the Faint Images of the Radio Sky at Twenty-centimeters survey. Without follow-up observations, the sources of the double-peaked narrow emission lines are uncertain, and may be produced by kpc-scale separation dual active supermassive black holes, AGN outflows, or disk rotation. In this work, we propose a new methodology to characterize double-peaked narrow emission-line galaxies based on optical long-slit spectroscopy and high resolution multi-band Very Large Array observations. The nature of the radio emission in the sample galaxies is varied. Of the 18 galaxies, we detect two compact flat-spectrum radio cores with projected spatial separations on the sky between 0.6-1.6 kpc in three galaxies: J1023+3243, J1158+3231, and J1623+0808. The ...

  19. Narrow-band single-photon emission in the near infrared for quantum key distribution.

    Science.gov (United States)

    Wu, E; Jacques, Vincent; Zeng, Heping; Grangier, Philippe; Treussart, François; Roch, Jean-François

    2006-02-06

    We present a detailed study of photophysical properties of single color centers in natural diamond samples emitting in the near infrared under optical excitation. Photoluminescence of these single emitters has several striking features, including narrow-band (FWHM 2 nm) fully polarized emission around 780 nm, a short excited-state lifetime of about 2 ns, and perfect photostability at room temperature under our excitation conditions. Development of a triggered single-photon source relying on this single color center is discussed for application to quantum key distribution.

  20. Narrow-band single-photon emission in the near infrared for quantum key distribution

    CERN Document Server

    Wu, E; Jacques, V; Zeng, H; Grangier, Philippe; Jacques, Vincent; Zeng, Heping

    2005-01-01

    We report on the observation of single colour centers in natural diamond samples emitting in the near infrared region when optically excited. Photoluminescence of these single emitters have several striking features, such as a narrow-band fully polarized emission (FWHM 2 nm) around 780 nm, a short excited-state lifetime of about 2 ns, and perfect photostability at room temperature under our excitation conditions. We present a detailed study of their photophysical properties. Development of a triggered single-photon source relying on this single colour centre is discussed in the prospect of its application to quantum key distribution.

  1. Narrow linewidth single-mode semiconductor laser development for coherent detection lidar

    Science.gov (United States)

    Mansour, Kamjou; Ksendzov, Alexander; Menzies, Robert T.; Maker, Paul D.; Muller, Richard E.; Manfra, M. J.; Turner, George W.

    2003-01-01

    High power, tunable, single mode, narrow linewidth semiconductor lasers in the 2.05-(micro)m wavelength region are needed to develop semiconductor laser reference oscillators for optical remote sensing from Earth orbit. 2.05-I1/4m narrow linewidth monolithic distributed feedback (DFB) and distributed Bragg reflector (DBR) with the external grating ridge waveguide lasers fabricated from epitaxially grown InGaAs/InGaAsP/InP and in InGaAsSb/AlGaAsSb/GaSb heterostructures are reported.

  2. Narrow linewidth single-mode semiconductor laser development for coherent detection lidar

    Science.gov (United States)

    Mansour, Kamjou; Ksendzov, Alexander; Menzies, Robert T.; Maker, Paul D.; Muller, Richard E.; Manfra, M. J.; Turner, George W.

    2003-01-01

    High power, tunable, single mode, narrow linewidth semiconductor lasers in the 2.05-(micro)m wavelength region are needed to develop semiconductor laser reference oscillators for optical remote sensing from Earth orbit. 2.05-I1/4m narrow linewidth monolithic distributed feedback (DFB) and distributed Bragg reflector (DBR) with the external grating ridge waveguide lasers fabricated from epitaxially grown InGaAs/InGaAsP/InP and in InGaAsSb/AlGaAsSb/GaSb heterostructures are reported.

  3. The Origin of Double-peaked Narrow Lines in Active Galactic Nuclei II: Kinematic Classifications for the Population at z < 0.1

    CERN Document Server

    Nevin, Rebecca; Müller-Sánchez, Francisco; Barrows, R Scott; Cooper, Michael

    2016-01-01

    We present optical longslit observations of the complete sample of 71 Type 2 active galactic nuclei (AGNs) with double-peaked narrow emission lines at $z < 0.1$ in the Sloan Digital Sky Survey. Double-peaked emission lines are produced by a variety of mechanisms including disk rotation, kpc-scale dual AGNs, and NLR kinematics (outflows or inflows). We develop a novel kinematic classification technique to determine the nature of these objects using longslit spectroscopy alone. We determine that 86% of the double-peaked profiles are produced by moderate luminosity AGN outflows, 6% are produced by rotation, and 8% are ambiguous. While we are unable to directly identify dual AGNs with longslit data alone, we explore their potential kinematic classifications with this method. We also find a positive correlation between the narrow-line region (NLR) size and luminosity of the AGN NLRs (R$_{\\mathrm{NLR}}\\propto \\; {\\mathrm{L}_{\\mathrm{[OIII]}}}^{0.21 \\pm 0.05}$), indicating a clumpy two-zone ionization model for t...

  4. The Origin of Double-peaked Narrow Lines in Active Galactic Nuclei. II. Kinematic Classifications for the Population at z < 0.1

    Science.gov (United States)

    Nevin, R.; Comerford, J.; Müller-Sánchez, F.; Barrows, R.; Cooper, M.

    2016-11-01

    We present optical long-slit observations of the complete sample of 71 Type 2 active galactic nuclei (AGNs) with double-peaked narrow emission lines at z < 0.1 in the Sloan Digital Sky Survey. Double-peaked emission lines are produced by a variety of mechanisms including disk rotation, kiloparsec-scale dual AGNs, and narrow-line region (NLR) kinematics (outflows or inflows). We develop a novel kinematic classification technique to determine the nature of these objects using long-slit spectroscopy alone. We determine that 86% of the double-peaked profiles are produced by moderate-luminosity AGN outflows, 6% are produced by rotation, and 8% are ambiguous. While we are unable to directly identify dual AGNs with long-slit data alone, we explore their potential kinematic classifications with this method. We also find a positive correlation between the NLR size and luminosity of the AGN NLRs (R {}{NLR}\\propto {L}[{{O} {{III}}]}0.21+/- 0.05), indicating a clumpy two-zone ionization model for the NLR.

  5. Kiloparsec-scale Spatial Offsets in Double-peaked Narrow-line AGNs. I. Markers for Selection of Compelling Dual AGN Candidates

    CERN Document Server

    Comerford, Julia M; Stern, Daniel; Cooper, Michael C; Weiner, Benjamin J; Newman, Jeffrey A; Harrison, Fiona; Madsen, Kristin; Barrows, R Scott

    2011-01-01

    Merger-remnant galaxies with kpc-scale separation dual active galactic nuclei (AGNs) should be widespread as a consequence of galaxy mergers and triggered gas accretion onto supermassive black holes, yet very few dual AGNs have been observed. Galaxies with double-peaked narrow AGN emission lines in the Sloan Digital Sky Survey are plausible dual AGN candidates, but their double-peaked profiles could also be the result of gas kinematics or AGN-driven outflows and jets on small or large scales. To help distinguish between these scenarios, we have obtained spatial profiles of the AGN emission via follow-up longslit spectroscopy of 81 double-peaked narrow-line AGNs in SDSS at 0.03 < z < 0.36 using Lick, Palomar, and MMT Observatories. We find that all 81 systems exhibit double AGN emission components with ~kpc projected spatial separations on the sky, which suggests that they are produced by kpc-scale dual AGNs or kpc-scale outflows, jets, or rotating gaseous disks. In addition, we find that the subsample (...

  6. KILOPARSEC-SCALE SPATIAL OFFSETS IN DOUBLE-PEAKED NARROW-LINE ACTIVE GALACTIC NUCLEI. I. MARKERS FOR SELECTION OF COMPELLING DUAL ACTIVE GALACTIC NUCLEUS CANDIDATES

    Energy Technology Data Exchange (ETDEWEB)

    Comerford, Julia M. [Astronomy Department, University of Texas at Austin, Austin, TX 78712 (United States); Gerke, Brian F. [Kavli Institute for Particle Astrophysics and Cosmology, M/S 29, Stanford Linear Accelerator Center, 2575 Sand Hill Road, Menlo Park, CA 94725 (United States); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, MS 169-221, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Cooper, Michael C. [Center for Galaxy Evolution, Department of Physics and Astronomy, University of California, Irvine, 4129 Frederick Reines Hall, Irvine, CA 92697 (United States); Weiner, Benjamin J. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Newman, Jeffrey A. [Department of Physics and Astronomy, Pittsburgh Particle Physics, Astrophysics, and Cosmology Center, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Madsen, Kristin [Space Radiation Laboratory, California Institute of Technology, MS 105-24, Pasadena, CA 91125 (United States); Barrows, R. Scott [Arkansas Center for Space and Planetary Sciences, University of Arkansas, Fayetteville, AR 72701 (United States)

    2012-07-01

    Merger-remnant galaxies with kiloparsec (kpc) scale separation dual active galactic nuclei (AGNs) should be widespread as a consequence of galaxy mergers and triggered gas accretion onto supermassive black holes, yet very few dual AGNs have been observed. Galaxies with double-peaked narrow AGN emission lines in the Sloan Digital Sky Survey (SDSS) are plausible dual AGN candidates, but their double-peaked profiles could also be the result of gas kinematics or AGN-driven outflows and jets on small or large scales. To help distinguish between these scenarios, we have obtained spatial profiles of the AGN emission via follow-up long-slit spectroscopy of 81 double-peaked narrow-line AGNs in SDSS at 0.03 {<=} z {<=} 0.36 using Lick, Palomar, and MMT Observatories. We find that all 81 systems exhibit double AGN emission components with {approx}kpc projected spatial separations on the sky (0.2 h{sup -1}{sub 70} kpc <{Delta}x < 5.5 h{sup -1}{sub 70} kpc; median {Delta}x = 1.1 h{sup -1}{sub 70} kpc), which suggests that they are produced by kiloparsec-scale dual AGNs or kiloparsec-scale outflows, jets, or rotating gaseous disks. Further, the objects split into two subpopulations based on the spatial extent of the double emission components and the correlation between projected spatial separations and line-of-sight velocity separations. These results suggest that the subsample (58{sup +5}{sub -6}%) of the objects with spatially compact emission components may be preferentially produced by dual AGNs, while the subsample (42{sup +6}{sub -5}%) with spatially extended emission components may be preferentially produced by AGN outflows. We also find that for 32{sup +8}{sub -6}% of the sample the two AGN emission components are preferentially aligned with the host galaxy major axis, as expected for dual AGNs orbiting in the host galaxy potential. Our results both narrow the list of possible physical mechanisms producing the double AGN components, and suggest several observational

  7. Investigation of spectral shifts in a white light interferometer with a single interference peak

    Science.gov (United States)

    Xu, Chunhui; Yi, Yingyan; Shu, Zhuo; Li, Min

    2015-04-01

    When the optical path difference between the two arms of an interferometer is so small that only one peak exists within the measurable interference spectrum, traditional white light interference demodulation techniques based on two adjacent interference peaks are not a suitable choice. We report an experimental approach to measure the peak wavelength shifts with only a single interference peak in a fiber white light interferometer. The temperature measurement experiments prove a linear relationship between the peak wavelength and the temperature. The temperature resolution is 0.1°C in theory.

  8. Single-Crystal Semiconductors with Narrow Band Gaps for Solar Water Splitting.

    Science.gov (United States)

    Wang, Tuo; Gong, Jinlong

    2015-09-07

    Solar water splitting provides a clean and renewable approach to produce hydrogen energy. In recent years, single-crystal semiconductors such as Si and InP with narrow band gaps have demonstrated excellent performance to drive the half reactions of water splitting through visible light due to their suitable band gaps and low bulk recombination. This Minireview describes recent research advances that successfully overcome the primary obstacles in using these semiconductors as photoelectrodes, including photocorrosion, sluggish reaction kinetics, low photovoltage, and unfavorable planar substrate surface. Surface modification strategies, such as surface protection, cocatalyst loading, surface energetics tuning, and surface texturization are highlighted as the solutions.

  9. Single-peak distribution model of particulate size for welding aerosols

    Institute of Scientific and Technical Information of China (English)

    施雨湘; 李爱农

    2003-01-01

    A large number of particulate size distributions of welding aerosols are measured by means of DMPS method, several distribution types are presented. Among them the single-peak distribution is the basic composing unit of particulate size. The research on the mathematic models and distributions functions shows that the single-peak distribution features the log-normal distribution. The diagram-estimating method (DEM) is a concise approach to dealing with distribution types, obtaining distribution functions for the particulate sizes of welding aerosols. It proves that the distribution function of particulate size possesses the extending property, being from quantity distribution to volume, as well as high-order moment distributions, with K-S method verifying the application of single-peak distribution and of DEM.

  10. A center frequency adjustable narrow band filter for the detection of weak single frequency signal.

    Science.gov (United States)

    Xin, Yunhong; Xiang, ZhenMing; Dong, LeMing; Zhu, Bing; Cao, Hui; Fang, Yu

    2014-04-01

    We describe and implement a center frequency adjustable narrow band filter based on the crystal filter for the detection of weak single frequency signal. It is formed by a multiplier, a direct digital frequency synthesizer, a multi-stage crystal bandpass filter, and a micro control unit which is used to set the center frequency of the filter. A theoretical study is proposed and experimentally validated. The test results show that the 3 db and 20 db bandwidths are 0.84 Hz and 2.73 Hz, respectively, and the filter system can effectively detect the signal with amplitude below 1 μV and a frequency which ranges from 10 Hz to the frequency that is mainly limited by the components applied.

  11. SEMICONDUCTOR DEVICES Negative bias temperature instability induced single event transient pulse narrowing and broadening

    Science.gov (United States)

    Jianjun, Chen; Shuming, Chen; Bin, Liang; Biwei, Liu

    2010-12-01

    The effect of negative bias temperature instability (NBTI) on a single event transient (SET) has been studied in a 130 nm bulk silicon CMOS process based on 3D TCAD device simulations. The investigation shows that NBTI can result in the pulse width and amplitude of SET narrowing when the heavy ion hits the PMOS in the high-input inverter; but NBTI can result in the pulse width and amplitude of SET broadening when the heavy ion hits the NMOS in the low-input inverter. Based on this study, for the first time we propose that the impact of NBTI on a SET produced by the heavy ion hitting the NMOS has already been a significant reliability issue and should be of wide concern, and the radiation hardened design must consider the impact of NBTI on a SET.

  12. Locating narrow bipolar events with single-station measurement of low-frequency magnetic fields

    Science.gov (United States)

    Zhang, Hongbo; Lu, Gaopeng; Qie, Xiushu; Jiang, Rubin; Fan, Yanfeng; Tian, Ye; Sun, Zhuling; Liu, Mingyuan; Wang, Zhichao; Liu, Dongxia; Feng, Guili

    2016-06-01

    We developed a method to locate the narrow bipolar events (NBEs) based on the single-station measurement of low-frequency (LF, 40-500 kHz) magnetic fields. The direction finding of a two-axis magnetic sensor provides the azimuth of NBEs relative to the measurement site; the ionospheric reflection pairs in the lightning sferics are used to determine the range and height. We applied this method to determine the three-dimensional (3D) locations of 1475 NBEs with magnetic signals recorded during the SHandong Artificially Triggered Lightning Experiment (SHATLE) in summer of 2013. The NBE detections are evaluated on a storm basis by comparing with radar observations of reflectivity and lightning data from the World Wide Lightning Location Network (WWLLN) for two mesoscale convective systems (MCSs) of different sizes. As revealed by previous studies, NBEs are predominately produced in the convective regions with relatively strong radar echo (with composite reflectivity ≥30 dBZ), although not all the convections with high reflectivity and active lightning production are in favor of NBE production. The NBEs located by the single-station magnetic method also exhibit the distinct segregation in altitude for positive and negative NBEs, namely positive NBEs are mainly produced between 7 km and 15 km, while negative NBEs are predominantly produced above 14 km. In summary, the results of comparison generally show that the single-station magnetic method can locate NBEs with good reliability, although the accuracy of 3D location remains to be evaluated with the traditional multi-station method based on the time-of-arrival technique. This method can be applied to track the motion of storm convection within 800 km, especially when they move out to ocean beyond the detection range (typically <400 km) of meteorological radars, making it possible to study NBEs in oceanic thunderstorms for which the location with multiple ground-based stations is usually not feasible.

  13. Method for predicting economic peak yield for a single well of coalbed methane

    Institute of Scientific and Technical Information of China (English)

    YANG Shen; KANG Yong-shang; ZHAO Qun; WANG Hong-yan; LI Jing-ming

    2008-01-01

    The development of coalbed methane (CBM) in China poses great difficulties because of high investments, low production and high risks. So a study of the economic effect of a single well at its preliminary stage is helpful for commercial exploitation of CBM. Affected by wellbore flow pressure, initial reservoir pressure, relative permeability, Langmuir pressure and other factors,the trend of declining production of a single CBM well agrees, by and large, with a hyperbolic pattern of decline. Based on Arps'sequation, nearly 200 wells production with different peak yields and initial rates of were simulated. Given the present cost of drilling, gas production and engineering on the ground, the gross investment for the development of a single coalbed methane well was estimated for the Fanzhuang block in central China. Considering the current industrial policies for CBM, we established an economic assessment model and analyzed economic peaks. The results show the economic benefits with or without government subsidies at different peak yields of a single CBM well. The results of the evaluation can be directly applied in the Fanzhuang block. The evaluation method, formulated in our study, can be used to other areas with similar conditions.

  14. Single gain peak from modulation instability in As2Se3 chalcogenide glass photonic crystal fiber

    Science.gov (United States)

    Wang, Helin; Yang, Aijun

    2016-09-01

    With the As2Se3 photonic crystal fiber (PCF), the effect of pump power and wavelength on modulation instability (MI) gain is studied in detail. Due to high Raman scattering effect and high nonlinearity of As2Se3 PCF, ultra-broadband MI gain is obtained when appropriate pump power and wavelength is chosen, and the optimal MI gain bandwidth reaches 2812 nm. More importantly, competing between Raman scattering and four-wave mixing results in a single gain peak observed in the anti-Stokes region of As2Se3 PCF when pump power is higher than about 3000 W, while there is no gain spectrum in the fiber Stokes region. The phenomenon is found for the first time, and the obtained single gain peak mainly results from Raman scattering effect.

  15. The acute effects of static stretching on peak force, peak rate of force development and muscle activity during single- and multiple-joint actions in older women.

    Science.gov (United States)

    Gonçalves, Raquel; Gurjão, André Luiz Demantova; Jambassi Filho, José Claudio; Farinatti, Paulo De Tarso Veras; Gobbi, Lilian Teresa Bucken; Gobbi, Sebastião

    2013-01-01

    The present study investigated the acute effects of static stretching on peak force, peak rate of force development and integrated electromyography (iEMG) in 27 older women (65 ± 4 years; 69 ± 9 kg; 157 ± 1 cm; 28 ± 4 kg · m(-2)). The participants were tested during two exercises (leg press and knee extension) after two conditions: stretching and control. The data were collected on four days (counterbalanced with a 24-hour rest period). In the stretching condition, the quadriceps muscle was stretched (knee flexion) for three sets of 30 s with 30 s rest intervals. No significant difference was detected for peak force and peak rate of force development during the single- and multiple-joint exercises, regardless of the following interactions: condition (stretching and control) vs. time (pre x post x 10 x 20 x 30 minutes post; P > 0.05) and exercise vs. time (P > 0.05). Additionally, no significant interaction was found for the iEMG activity (condition vs. time; P > 0.05) in the single- and multiple-joint exercises. In conclusion, a small amount of stretching of an agonist muscle (quadriceps) did not affect the peak force, peak rate of force development and EMG activity in older women during single- and multiple-joint exercises.

  16. Kondo peak splitting and Kondo dip in single molecular magnet junctions

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Pengbin, E-mail: 120233951@qq.com [Institute of Solid State Physics, Shanxi Datong University, Datong 037009 (China); Shi, Yunlong; Sun, Zhu [Institute of Solid State Physics, Shanxi Datong University, Datong 037009 (China); Nie, Yi-Hang [Institute of Theoretical Physics, Shanxi University, Taiyuan 030006 (China); Luo, Hong-Gang [Center for Interdisciplinary Studies & Key Laboratory for Magnetism and Magnetic Materials of the MoE, Lanzhou University, Lanzhou 730000 (China); Beijing Computational Science Research Center, Beijing 100084 (China)

    2016-01-15

    Many factors containing bias, spin–orbit coupling, magnetic fields applied, and so on can strongly influence the Kondo effect, and one of the consequences is Kondo peak splitting (KPS). It is natural that KPS should also appear when another spin degree of freedom is involved. In this work we study the KPS effects of single molecular magnets (SMM) coupled with two metallic leads in low-temperature regime. It is found that the Kondo transport properties are strongly influenced by the exchange coupling and anisotropy of the magnetic core. By employing Green's function method in Hubbard operator representation, we give an analytical expression for local retarded Green's function of SMM and discussed its low-temperature transport properties. We find that the anisotropy term behaves as a magnetic field and the splitting behavior of exchange coupling is quite similar to the spin–orbit coupling. These splitting behaviors are explained by introducing inter-level or intra-level transitions, which account for the seven-peak splitting structure. Moreover, we find a Kondo dip at Fermi level under proper parameters. These Kondo peak splitting behaviors in SMM deepen our understanding to Kondo physics and should be observed in the future experiments. - Highlights: • We study Kondo peak splitting in single molecular magnets. • We study Kondo effect by Hubbard operator Green's function method. • We find Kondo peak splitting structures and a Kondo dip at Fermi level. • The exchange coupling and magnetic anisotropy induce fine splitting structure. • The splitting structures are explained by inter-level or intra-level transitions.

  17. Study of the peak effect phenomenon in single crystals of 2H-NbSe2

    Indian Academy of Sciences (India)

    C V Tomy; D Pal; S S Banerjee; S Ramakrishnan; A K Grover; S Bhattacharya; M Higgins; G Balakrishnan; McK Paul

    2002-05-01

    The weakly pinned single crystals of the hexagonal 2H-NbSe2 compound have emerged as prototypes for determining and characterizing the phase boundaries of the possible order–disorder transformations in the vortex matter. We present here a status report based on the ac and dc magnetization measurements of the peak effect phenomenon in three crystals of 2H-NbSe2, in which the critical current densities vary over two orders of magnitude. We sketch the generic vortex phase diagram of a weakly pinned superconductor, which also utilizes theoretical proposals. We also establish the connection between the metastability effects and pinning.

  18. Single-cycle multiterahertz transients with peak fields above 10 MV/cm.

    Science.gov (United States)

    Junginger, F; Sell, A; Schubert, O; Mayer, B; Brida, D; Marangoni, M; Cerullo, G; Leitenstorfer, A; Huber, R

    2010-08-01

    Phase-locked single-cycle transients with frequency components between 1 and 60THz and peak fields of up to 12MV/cm are generated as the idler wave of a parametric amplifier. To achieve broadband conversion in GaSe nonlinear crystals, we match the group velocities of signal and idler components. The influence of group-velocity dispersion is minimized by long-wavelength pumping at 1.18mum. Free-space electro-optic sampling monitors the multiterahertz waveforms with direct field resolution.

  19. Finite population size effects in quasispecies models with single-peak fitness landscape

    Science.gov (United States)

    Saakian, David B.; Deem, Michael W.; Hu, Chin-Kun

    2012-04-01

    We consider finite population size effects for Crow-Kimura and Eigen quasispecies models with single-peak fitness landscape. We formulate accurately the iteration procedure for the finite population models, then derive the Hamilton-Jacobi equation (HJE) to describe the dynamic of the probability distribution. The steady-state solution of HJE gives the variance of the mean fitness. Our results are useful for understanding the population sizes of viruses in which the infinite population models can give reliable results for biological evolution problems.

  20. A Mathematical Model for Singly-Peaked Population Processes from Breeding to Extinction

    CERN Document Server

    Huzimura, R; Huzimura, Ryoitiro; Matsuyama, Toyoki

    1999-01-01

    When a small number of individuals of organism of single species is confined in a closed space with limited amount of indispensable resources, their breading may start initially under suitable conditions, and after peaking, the population should go extinct as the resources are exhausted. Assuming that the carrying capacity of the environment is a function of resource amount, a mathematical model describing such pattern of population change is obtained. An application of this model to typical population records, that of deer herds by Scheffer (1951) and O'Roke and Hamerstrome (1948), yields estimations of the initial amount of indispensable food and its availability or nutritional efficiency which were previously unspecified.

  1. Peak Effect Evolution In Successive Proton Irradiated YBa2Cu3O7-d Single Crystals

    Science.gov (United States)

    Tobos, Valentina; Paulius, L. M.; Petrean, A. M.; Olsson, R. J.; Kwok, W.-K.; Ferguson, S.; Crabtree, G. W.

    2000-03-01

    We report on the effects of point-like disorder on the pinning properties of an untwinned, single crystal of YBa2Cu3O7-d. We use magnetic hysteresis measurements in order to determine the critical current density for temperatures ranging from 10 K to 80 K in fields up to 7 T. Measurements were performed on a high quality, detwinned, single crystal of YBa2Cu3O7-d that displays a first order vortex melting transition. The sample was cleaved in two parts. One half was used for electrical transport measurements, and the other for magnetization measurements, making it possible to compare between the effects of irradiation induced defects on the critical current density in two different ranges of temperatures. We discuss the effects of the irradiation on the magnetization, critical current density, the peak effect, and vortex phase diagram. This work was supported by National Scince Foundation grant DMR-97-03732 and DMR-96-24047.

  2. Visualized study on specific points on demand curves and flow patterns in a single-side heated narrow rectangular channel

    Energy Technology Data Exchange (ETDEWEB)

    Wang Junfeng [CNNC Key Laboratory on Reactor Thermo-Hydraulics Technology, Nuclear Power Institute of China, Chengdu, Sichuan (China); Huang Yanping, E-mail: hypgroup@163.com [CNNC Key Laboratory on Reactor Thermo-Hydraulics Technology, Nuclear Power Institute of China, Chengdu, Sichuan (China); Wang Yanlin [CNNC Key Laboratory on Reactor Thermo-Hydraulics Technology, Nuclear Power Institute of China, Chengdu, Sichuan (China)

    2011-10-15

    Highlights: > Specific points on the demand curve and flow patterns are visually studied. > Bubbly, churn, and annular flows were observed. > Onset of flow instability and bubbly-churn transition occurs at the same time. > The evolution of specific points and flow pattern transitions were examined. - Abstract: A simultaneous visualization and measurement study on some specific points on demand curves, such as onset of nucleate boiling (ONB), onset of significant void (OSV), onset of flow instability (OFI), and two-phase flow patterns in a single-side heated narrow rectangular channel, having a width of 40 mm and a gap of 3 mm, was carried out. New experimental approaches were adopted to identify OSV and OFI in a narrow rectangular channel. Under experimental conditions, the ONB could be predicted well by the Sato and Matsumura model. The OSV model of Bowring can reasonably predict the OSV if the single-side heated condition is considered. The OFI was close to the saturated boiling point and could be described accurately by Kennedy's correlation. The two-phase flow patterns observed in this experiment could be classified into bubbly, churn, and annular flow. Slug flow was never observed. The OFI always occurred when the bubbles at the channel exit began to coalesce, which corresponded to the beginning of the bubbly-churn transition in flow patterns. Finally, the evolution of specific points and flow pattern transitions were examined in a single-side heated narrow rectangular channel.

  3. Multicomponent ballistic transport in narrow single wall carbon nanotubes: Analytic model and molecular dynamics simulations

    Science.gov (United States)

    Mutat, T.; Adler, J.; Sheintuch, M.

    2011-01-01

    The transport of gas mixtures through molecular-sieve membranes such as narrow nanotubes has many potential applications, but there remain open questions and a paucity of quantitative predictions. Our model, based on extensive molecular dynamics simulations, proposes that ballistic motion, hindered by counter diffusion, is the dominant mechanism. Our simulations of transport of mixtures of molecules between control volumes at both ends of nanotubes give quantitative support to the model's predictions. The combination of simulation and model enable extrapolation to longer tubes and pore networks.

  4. Resonance response of a single-degree-of-freedom nonlinear vibro-impact system to a narrow-band random parametric excitation

    Institute of Scientific and Technical Information of China (English)

    Su Min-Bang; Rong Hai-Wu

    2011-01-01

    The resonant response of a single-degree-of-freedom nonlinear vibro-impact oscillator with a one-sided barrier to a narrow-band random parametric excitation is investigated. The narrow-band random excitation used here is a bounded random noise. The analysis is based on a special Zhuravlev transformation, which reduces the system to one without impacts, thereby permitting the applications of random averaging over "fast" variables. The averaged equations are solved exactly and an algebraic equation of the amplitude of the response is obtained for the case without random disorder. The methods of linearization and moment are used to obtain the formula of the mean-square amplitude approximately for the case with random disorder. The effects of damping, detuning, restitution factor, nonlinear intensity, frequency and magnitude of random excitations are analysed. The theoretical analyses are verified by numerical results. Theoretical analyses and numerical simulations show that the peak response amplitudes will reduce at large damping or large nonlinear intensity and will increase with large amplitude or frequency of the random excitations. The phenomenon of stochastic jump is observed, that is, the steady-state response of the system will jump from a trivial solution to a large non-trivial one when the amplitude of the random excitation exceeds some threshold value,or will jump from a large non-trivial solution to a trivial one when the intensity of the random disorder of the random excitation exceeds some threshold value.

  5. Subharmonic response of a single-degree-of-freedom nonlinear vibro-impact system to a narrow-band random excitation.

    Science.gov (United States)

    Haiwu, Rong; Wang, Xiangdong; Xu, Wei; Fang, Tong

    2009-08-01

    The subharmonic response of single-degree-of-freedom nonlinear vibro-impact oscillator with a one-sided barrier to narrow-band random excitation is investigated. The narrow-band random excitation used here is a filtered Gaussian white noise. The analysis is based on a special Zhuravlev transformation, which reduces the system to one without impacts, or velocity jumps, thereby permitting the applications of asymptotic averaging over the "fast" variables. The averaged stochastic equations are solved exactly by the method of moments for the mean-square response amplitude for the case of linear system with zero offset. A perturbation-based moment closure scheme is proposed and the formula of the mean-square amplitude is obtained approximately for the case of linear system with nonzero offset. The perturbation-based moment closure scheme is used once again to obtain the algebra equation of the mean-square amplitude of the response for the case of nonlinear system. The effects of damping, detuning, nonlinear intensity, bandwidth, and magnitudes of random excitations are analyzed. The theoretical analyses are verified by numerical results. Theoretical analyses and numerical simulations show that the peak amplitudes may be strongly reduced at large detunings or large nonlinear intensity.

  6. Single motherhood and low birthweight in Spain: Narrowing social inequalities in health?

    Directory of Open Access Journals (Sweden)

    Teresa Castro-Martin

    2010-05-01

    Full Text Available Nonmarital childbearing is becoming an increasingly common path to family formation in Spain. The proportion of births to unmarried mothers has increased from 2Š in 1975 to 30.2Š in 2007. Along with this marked increase, there has been an important shift in the sociodemographic profile of unmarried mothers. This study focuses on the impact of mothers' marital status on the health status of their newborns, using low birthweight as an indicator. We are interested in examining how the impact of mothers' unmarried status on birth outcomes changes as nonmarital childbearing shifts from a marginal to a relatively common behaviour. The results of the analysis reveal that the health disadvantage gap between marital and nonmarital births has narrowed significantly over the past decade in Spain. We argue that diminishing selection processes and increasing social acceptance could explain the declining significance of marital status as a risk factor for low birthweight.

  7. Influence of photo- and thermal bleaching on pre-irradiation low water peak single mode fibers

    Science.gov (United States)

    Yin, Jianchong; Wen, Jianxiang; Luo, Wenyun; Xiao, Zhongyin; Chen, Zhenyi; Wang, Tingyun

    2011-12-01

    Reducing the radiation-induced transmission loss in low water peak single mode fiber (LWP SMF) has been investigated by using photo-bleaching method with 980nm pump light source and using thermal-bleaching method with temperature control system. The results show that the radiation-induced loss of pre-irradiation optical fiber can be reduced effectively with the help of photo-bleaching or thermal-bleaching. Although the effort of photo-bleaching is not as significant as thermal-bleaching, by using photo-bleaching method, the loss of fiber caused by radiation-induced defects can be reduced best up to 49% at 1310nm and 28% at 1550nm in low pre-irradiation condition, the coating of the fiber are not destroyed, and the rehabilitating time is just several hours, while self-annealing usually costs months' time. What's more, the typical high power LASER for photo-bleaching can be 980nm pump Laser Diode, which is very accessible.

  8. Statistical properties and error threshold of quasispecies on single-peak Gaussian-distributed fitness landscapes.

    Science.gov (United States)

    Li, Duo-Fang; Cao, Tian-Guang; Geng, Jin-Peng; Gu, Jian-Zhong; An, Hai-Long; Zhan, Yong

    2015-09-07

    The stochastic Eigen model proposed by Feng et al. (2007) (Journal of Theoretical Biology, 246, 28) showed that error threshold is no longer a phase transition point but a crossover region whose width depends on the strength of the random fluctuation in an environment. The underlying cause of this phenomenon has not yet been well examined. In this article, we adopt a single peak Gaussian distributed fitness landscape instead of a constant one to investigate and analyze the change of the error threshold and the statistical property of the quasi-species population. We find a roughly linear relation between the width of the error threshold and the fitness fluctuation strength. For a given quasi-species, the fluctuation of the relative concentration has a minimum with a normal distribution of the relative concentration at the maximum of the averaged relative concentration, it has however a largest value with a bimodal distribution of the relative concentration near the error threshold. The above results deepen our understanding of the quasispecies and error threshold and are heuristic for exploring practicable antiviral strategies.

  9. High ionic strength narrows the population of sites participating in protein ion-exchange adsorption: a single-molecule study.

    Science.gov (United States)

    Kisley, Lydia; Chen, Jixin; Mansur, Andrea P; Dominguez-Medina, Sergio; Kulla, Eliona; Kang, Marci K; Shuang, Bo; Kourentzi, Katerina; Poongavanam, Mohan-Vivekanandan; Dhamane, Sagar; Willson, Richard C; Landes, Christy F

    2014-05-23

    The retention and elution of proteins in ion-exchange chromatography is routinely controlled by adjusting the mobile phase salt concentration. It has repeatedly been observed, as judged from adsorption isotherms, that the apparent heterogeneity of adsorption is lower at more-eluting, higher ionic strength. Here, we present an investigation into the mechanism of this phenomenon using a single-molecule, super-resolution imaging technique called motion-blur Points Accumulation for Imaging in Nanoscale Topography (mbPAINT). We observed that the number of functional adsorption sites was smaller at high ionic strength and that these sites had reduced desorption kinetic heterogeneity, and thus narrower predicted elution profiles, for the anion-exchange adsorption of α-lactalbumin on an agarose-supported, clustered-charge ligand stationary phase. Explanations for the narrowing of the functional population such as inter-protein interactions and protein or support structural changes were investigated through kinetic analysis, circular dichroism spectroscopy, and microscopy of agarose microbeads, respectively. The results suggest the reduction of heterogeneity is due to both electrostatic screening between the protein and ligand and tuning the steric availability within the agarose support. Overall, we have shown that single molecule spectroscopy can aid in understanding the influence of ionic strength on the population of functional adsorbent sites participating in the ion-exchange chromatographic separation of proteins.

  10. Fast calcium and voltage-sensitive dye imaging in enteric neurones reveal calcium peaks associated with single action potential discharge.

    Science.gov (United States)

    Michel, K; Michaelis, M; Mazzuoli, G; Mueller, K; Vanden Berghe, P; Schemann, M

    2011-12-15

    Slow changes in [Ca(2+)](i) reflect increased neuronal activity. Our study demonstrates that single-trial fast [Ca(2+)](i) imaging (≥200 Hz sampling rate) revealed peaks each of which are associated with single spike discharge recorded by consecutive voltage-sensitive dye (VSD) imaging in enteric neurones and nerve fibres. Fast [Ca(2+)](i) imaging also revealed subthreshold fast excitatory postsynaptic potentials. Nicotine-evoked [Ca(2+)](i) peaks were reduced by -conotoxin and blocked by ruthenium red or tetrodotoxin. Fast [Ca(2+)](i) imaging can be used to directly record single action potentials in enteric neurones. [Ca(2+)](i) peaks required opening of voltage-gated sodium and calcium channels as well as Ca(2+) release from intracellular stores.

  11. Investigation of Line Width Narrowing and Spectral Jumps of Single Stable Defect Centers in ZnO at Cryogenic Temperature.

    Science.gov (United States)

    Neitzke, Oliver; Morfa, Anthony; Wolters, Janik; Schell, Andreas W; Kewes, Günter; Benson, Oliver

    2015-05-13

    Finding new solid state defect centers in novel host materials is crucial for realizing integrated hybrid quantum photonic devices. We present a preparation method for defect centers with photostable bright single photon emission in zinc oxide, a material with promising properties in terms of processability, availability, and applications. A detailed optical study reveals a complex dynamic of intensity fluctuations at room temperature. Measurements at cryogenic temperatures show very sharp (<60 GHz) zero phonon lines (ZPLs) at 580 nm to  620 nm (≈ 2.0 eV) with frozen out fast fluctuations. Remaining discrete jumps of the ZPL, which depend on the excitation power, are observed. The low temperature results will narrow down speculations on the origin of visible-near-infrared (NIR) wavelength defect emission in zinc oxide and provide a basis for improved theoretical models.

  12. Correlation between pulse-width and peak luminosity of single-pulse long gamma-ray bursts

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    With a sample of 21 single-pulse GRBs with redshift measurement and a sample of 65 single-pulse GRBs with pseudo redshift estimated by the luminosity-spectral lag relation,we show that the peak luminosities of GRB pulses are anti-correlated with pulse width,indicating that longer-pulses tend to be dimmer in the gamma-ray band.The anti-correlation is accessible with an internal shock scenario.

  13. Narrow line-width single-longitudinal-mode fiber laser using silicon-on-insulator based micro-ring-resonator

    Science.gov (United States)

    Liu, Yang; Hsu, Yung; Hsu, Chin-Wei; Yang, Ling-Gang; Chow, Chi-Wai; Yeh, Chien-Hung; Lai, Yin-Chieh; Tsang, Hon-Ki

    2016-02-01

    In this work, we propose and demonstrate a stable single-longitudinal-mode (SLM) fiber laser with narrow line-width by using an integrated silicon-on-insulator micro-ring resonator (SOI MRR) and two subsidiary fiber rings for the first time, to the best of our knowledge. The laser is tunable over the wavelength range from 1546 to 1570 nm, with only step tuning of 2 nm steps. A maximum 49 dB side mode suppression ratio (SMSR) can be achieved. The compact SOI MRR provides a large free-spectral-range (FSR), while the subsidiary rings provide Vernier effect producing a single lasing mode. The FSR of the SOI MRR can be very large and controllable (since it is easy to fabricate small SOI MRR when compared with making small fiber-rings) using the complementary-metal-oxide-semiconductor (CMOS) compactable SOI fabrication processes. In our proposed laser, the measured single sideband (SSB) spectrum shows that the densely spaced longitudinal modes can be significantly suppressed to achieve SLM. The laser linewidth is only 3.5 kHz measured by using the self-heterodyne method. 30 min stability evaluation in terms of lasing wavelength and optical power is performed; showing the optical wavelength and power are both very stable, with fluctuations of only 0.02 nm and 0.8 dB, respectively.

  14. Prediction of Single-Peak Flow Stress Curves at High Temperatures Using a New Logarithmic-Power Function

    Science.gov (United States)

    Shafiei, Ehsan; Dehghani, Kamran

    2016-09-01

    In this study, using a nonlinear estimation of strain hardening rate versus strain, a new phenomenological constitutive equation is developed. Utilizing the presented model, three new equations were presented to determine the peak strain, critical strain for initiation of dynamic recrystallization (DRX), and transition strain associated with the maximum softening rate of DRX. Also, two temperature and strain rate-sensitive parameters were introduced to generate flow stress curve at any desired deformation conditions. The predicted results were found to be in a good agreement with the ones measured experimentally. Maximum errors in prediction of peak strain, critical strain, and transition strain were about 8, 11, and 4%, respectively. In addition, evaluation of maximum errors in prediction of flow stress indicates that the presented constitutive equation gives a more precise estimation of flow stress curves in comparison with the previous models pertaining modeling of single-peak flow stress curves.

  15. Observation of narrow (3$\\pi$)$\\pm$ peaks in the $\\delta$ and A$\\_{1}$ regions in $\\overline{p}p$ annihilations at 5.7 GeV/c

    CERN Document Server

    Atherton, Henry W; French, Bernard R; Ghidini, B; Hilpert, H G; Kinson, J B; Mandelli, L; Moebes, J P; Myklebost, K; Nellen, B; Quercigh, Emanuele; Simák, V

    1973-01-01

    In the pi /sup +/ pi /sup -/ pi /sup +or-/ systems of the reactions pp to KKm pi (m=4,5) two narrow peaks are observed at the positions of the delta and A/sub 1/ mesons. The measured masses and widths are: M= (956+or-7)MeV, Gamma =(46+or-22)MeV for the delta and M=(1076+or-5)Me V, Gamma =(36/sup +20//sub -15/)MeV, for the A/sub 1/. Their decay modes and spin-parities are shown to be mainly 3 pi , J/sup P/=0/sup - / and rho pi , J/sup P/=1/sup +/(D-wave) respectively. (8 refs).

  16. How to use your peak flow meter

    Science.gov (United States)

    Peak flow meter - how to use; Asthma - peak flow meter; Reactive airway disease - peak flow meter; Bronchial asthma - peak flow meter ... If your airways are narrowed and blocked due to asthma, your peak flow values drop. You can ...

  17. Peak effect studies in single crystals CeRu2 and 2H-NbS2

    Indian Academy of Sciences (India)

    A A Tulapurkar; A K Grover; S Ramakrishnan; A Niazi; A K Rastogi

    2002-05-01

    We have studied the peak effect (PE) phenomenon in single crystals of weakly pinned superconductors CeRu2 and 2H-NbS2. 2H-NbS2 is iso-structural and iso-electronic to 2H-NbSe2, whose similarity with CeRu2 as regards the PE representing the order-to-disorder transformation of the flux line lattice was claimed some time ago. We report on the step change in equilibrium magnetization across the peak effect in CeRu2. We also present the vortex phase diagram of 2H-NbS2 obtained from the magnetization data, and compare the PE phenomenon in 2H-NbS2 and 2H-NbSe2.

  18. A 3D profile function suitable for integration of neutron time-of-flight single crystal diffraction peaks

    Science.gov (United States)

    Gutmann, Matthias J.

    2017-03-01

    A 3D profile function is presented suitable to integrate reflections arising in time-of-flight (TOF) single crystal neutron diffraction experiments. In order to account for the large asymmetry of the peak shape in the TOF direction, a 3D Gaussian ellipsoid in the pixel (x, z) and time-of-flight coordinates is convoluted with a rising and falling exponential along the time-of-flight direction. An analytic expression is derived, making it suitable for least-squares fitting. The application of this function in detector space or reciprocal space is straightforward.

  19. Dicke-Narrowing Spectroscopy of Doubly Dressed Electromagnetically Induced Transparency and Singly Dressed Four-Wave-Mixing in a Confined Atomic System

    Institute of Scientific and Technical Information of China (English)

    LI Yuan-Yuan; BAI Jin-Wao; LI-Li; ZHANG Wei-Feng; LI Chang-Biao; NIE Zhi-Qiang; GAN Chen-Li; ZHANG Yan-Peng

    2008-01-01

    Dicke-narrowing effect appears both in doubly dressed electromagnetically induced transparency and singly dressed four-wave-mixing lines due to the contribution of slow atoms resulting from de-excited effects of atom-wall collision and transient behaviour of atoms in a confined system. A robust recipe for high resolution spectroscopy of electromagnetically induced transparency dressed by two fields and four-wave-mixing lines comparable with the cold atoms is achievable in a thin vapour cell in experiments.

  20. Multi-tap complex-coefficient incoherent microwave photonic filters based on optical single-sideband modulation and narrow band optical filtering.

    Science.gov (United States)

    Sagues, Mikel; García Olcina, Raimundo; Loayssa, Alayn; Sales, Salvador; Capmany, José

    2008-01-07

    We propose a novel scheme to implement tunable multi-tap complex coefficient filters based on optical single sideband modulation and narrow band optical filtering. A four tap filter is experimentally demonstrated to highlight the enhanced tuning performance provided by complex coefficients. Optical processing is performed by the use of a cascade of four phase-shifted fiber Bragg gratings specifically fabricated for this purpose.

  1. Characteristics of Extra Narrow Gap Weld of HSLA Steel Welded by Single-Seam per Layer Pulse Current GMA Weld Deposition

    Science.gov (United States)

    Agrawal, B. P.; Ghosh, P. K.

    2017-03-01

    Butt weld joints are produced using pulse current gas metal arc welding process by employing the technique of centrally laid multi-pass single-seam per layer weld deposition in extra narrow groove of thick HSLA steel plates. The weld joints are prepared by using different combination of pulse parameters. The selection of parameter of pulse current gas metal arc welding is done considering a summarized influence of simultaneously interacting pulse parameters defined by a dimensionless hypothetical factor ϕ. The effect of diverse pulse parameters on the characteristics of weld has been studied. Weld joint is also prepared by using commonly used multi-pass multi-seam per layer weld deposition in conventional groove. The extra narrow gap weld joints have been found much superior to the weld joint prepared by multi-pass multi-seam per layer deposition in conventional groove with respect to its metallurgical characteristics and mechanical properties.

  2. Constraining viewing geometries of pulsars with single-peaked gamma-ray profiles using a multiwavelength approach

    CERN Document Server

    Seyffert, A S; Johnson, T J; Harding, A K

    2012-01-01

    Since the launch of the Large Area Telescope (LAT) on board the Fermi spacecraft in June 2008, the number of observed gamma-ray pulsars has increased dramatically. A large number of these are also observed at radio frequencies. Constraints on the viewing geometries of 5 of 6 gamma-ray pulsars exhibiting single-peaked gamma-ray profiles were derived using high-quality radio polarization data (Weltevrede et al., 2010). We obtain independent constraints on the viewing geometries of 6 by using a geometric emission code to model the Fermi LAT and radio light curves (LCs). We find fits for the magnetic inclination and observer angles by searching the solution space by eye. Our results are generally consistent with those previously obtained (Weltevrede et al., 2010), although we do find small differences in some cases. We will indicate how the gamma-ray and radio pulse shapes as well as their relative phase lags lead to constraints in the solution space. Values for the flux correction factor corresponding to the fit...

  3. Neurobehavioral and neurophysiological effects after acute exposure to a single peak of 200 ppm toluene in healthy volunteers.

    Science.gov (United States)

    Kobald, S Oliver; Wascher, Edmund; Blaszkewicz, Meinolf; Golka, Klaus; van Thriel, Christoph

    2015-05-01

    The solvent toluene has neurotoxic properties that are especially relevant in the working environment. Short-term exposure limits (STELs) vary from 50 ppm up to 300 ppm across countries but their acute effects remain elusive in humans. Several in vitro and in vivo studies elucidated that toluene acutely acts by perturbations of different neurotransmitter systems. More specifically visual evoked potentials (VEPs) of rats are decreased after acute toluene exposure, leading to the assumption that particularly visual attention processes might be a target of toluene in humans. Therefore a visual change detection task was applied to measure both neurobehavioral and neurophysiological effects by using electroencephalography (EEG) after a single peak exposure to 200 ppm toluene. Performance and event-related components of the EEG were examined before and after exposure in a toluene-exposed and a control group. Thirty-three young healthy volunteers participated in this study. The behavioral results of the experiment indicate that toluene impairs the rate of correct responses especially in task conditions in which an irrelevant distractor is given, while the response times did not differ between both groups. The neurophysiological findings hint toward a less efficient visual processing of behaviorally relevant stimuli and an increased distractibility by irrelevant distractors. Thus the present results are a promising starting point for further research specifically targeting visual attention after toluene exposure and the reconsideration of the presently very heterogeneous STELs.

  4. Tunable and switchable dual-wavelength single polarization narrow linewidth SLM erbium-doped fiber laser based on a PM-CMFBG filter.

    Science.gov (United States)

    Yin, Bin; Feng, Suchun; Liu, Zhibo; Bai, Yunlong; Jian, Shuisheng

    2014-09-22

    A tunable and switchable dual-wavelength single polarization narrow linewidth single-longitudinal-mode (SLM) erbium-doped fiber (EDF) ring laser based on polarization-maintaining chirped moiré fiber Bragg grating (PM-CMFBG) filter is proposed and demonstrated. For the first time as we know, the CMFBG inscribed on the PM fiber is applied for the wavelength-tunable and-switchable dual-wavelength laser. The PM-CMFBG filter with ultra-narrow transmission band (0.1 pm) and a uniform polarization-maintaining fiber Bragg grating (PM-FBG) are used to select the laser longitudinal mode. The stable single polarization SLM operation is guaranteed by the PM-CMFBG filter and polarization controller. A tuning range of about 0.25 nm with about 0.075 nm step is achieved by stretching the uniform PM-FBG. Meanwhile, the linewidth of the fiber laser for each wavelength is approximate 6.5 and 7.1 kHz with a 20 dB linewidth, which indicates the laser linewidth is approximate 325 Hz and 355 Hz FWHM.

  5. Development of a Single-Frequency Narrow Linewidth 1.5mm Semiconductor Laser Suitable for Spaceflight Operation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Many space applications rely on the utilization of Light Detection and Raging (LIDAR) techniques. A key component of any LIDAR system is the laser source. Single...

  6. Development of a Single-Frequency Narrow Linewidth 1.5mm Semiconductor Laser Suitable for Spaceflight Operation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this Phase II proposal we plan to design and develop a semiconductor, low phase/frequency noise, single-frequency, external cavity semiconductor laser (ECL)...

  7. The Application of Multiobjective Genetic Algorithm to the Parameter Optimization of Single-Well Potential Stochastic Resonance Algorithm Aimed at Simultaneous Determination of Multiple Weak Chromatographic Peaks

    Directory of Open Access Journals (Sweden)

    Haishan Deng

    2014-01-01

    Full Text Available Simultaneous determination of multiple weak chromatographic peaks via stochastic resonance algorithm attracts much attention in recent years. However, the optimization of the parameters is complicated and time consuming, although the single-well potential stochastic resonance algorithm (SSRA has already reduced the number of parameters to only one and simplified the process significantly. Even worse, it is often difficult to keep amplified peaks with beautiful peak shape. Therefore, multiobjective genetic algorithm was employed to optimize the parameter of SSRA for multiple optimization objectives (i.e., S/N and peak shape and multiple chromatographic peaks. The applicability of the proposed method was evaluated with an experimental data set of Sudan dyes, and the results showed an excellent quantitative relationship between different concentrations and responses.

  8. Narrow conductive structures with high aspect ratios through single-pass inkjet printing and evaporation-induced dewetting

    NARCIS (Netherlands)

    Abbel, R.; Teunissen, P.; Michels, J.; Groen, W.A.

    2015-01-01

    Inkjet printed silver lines contract to widths below 20-μm during drying on an organic planarization coating. Aspect ratios previously unprecedented with single pass inkjet printing on isotropic homogeneous substrates are obtained. This effect is caused by the subsequent evaporation of solvents from

  9. Narrow-linewidth chirped frequency comb from a frequency-shifted feedback Ti:sapphire laser seeded by a phase-modulated single-frequency fiber laser.

    Science.gov (United States)

    Brandl, Matthias F; Mücke, Oliver D

    2010-12-15

    Frequency-shifted feedback (FSF) lasers have emerged as powerful tools for precision distance metrology. At the output of a Michelson interferometer, the detected rf spectra of the FSF laser light contain a length-dependent heterodyne beat signal whose linewidth ultimately limits the achievable accuracy of length measurements. Here, we demonstrate a narrow-linewidth chirped frequency comb from an FSF Ti:sapphire ring laser seeded by a phase-modulated, ultra-low-phase-noise, single-frequency fiber laser. We experimentally investigate the influence of the seed laser linewidth on the resulting width and shape of the length-dependent rf beat signal. An ultranarrow heterodyne beat linewidth of <20 Hz is observed.

  10. Optimal focusing for maximal collection of entangled narrow-band photon pairs into single-mode fibers

    CERN Document Server

    Ljunggren, D; Ljunggren, Daniel; Tengner, Maria

    2005-01-01

    We present a theoretical and experimental investigation of the emission characteristics and the flux of photon pairs generated by spontaneous parametric downconversion in quasi-phase matched bulk crystals for the use in quantum communication sources. We show that, by careful design, one can attain well defined modes close to the fundamental mode of optical fibers and obtain high coupling efficiencies also for bulk crystals, these being more easily aligned than crystal waveguides. We distinguish between singles coupling, conditional coincidence, and pair coupling, and show how each of these parameters can be maximized by varying the focusing of the pump mode and the fiber-matched modes using standard optical elements. Specifically we analyze a periodically poled KTP-crystal pumped by a 532 nm laser creating photon pairs at 810 nm and 1550 nm. Numerical calculations lead to coupling efficiencies above 94% at optimal focusing, which is found by the geometrical relation L/z_R to be ~ 1 to 2 for the pump mode and ...

  11. Impaired exercise-related myocardial uptake of technetium-99m-tetrofosmin in relation to coronary narrowing and diabetic state: assessment with quantitative single photon emission computed tomography.

    Science.gov (United States)

    Sasao, H; Nakata, T; Tsuchihashi, K; Wakabayashi, T; Nakaihara, N; Doi, A; Hashimoto, A; Kobayashi, H; Shimamoto, K

    2001-01-01

    Despite the diagnostic efficacy of stress myocardial perfusion imaging, the correlation between the actual perfusion tracer activity and diseased state of a coronary artery has not been studied in detail. We estimated exercise-related perfusion augmentation in relation to disease states of a coronary artery in diabetic and non-diabetic patients by a newly developed quantitative technetium (Tc)-99m-tetrofosmin myocardial imaging technique. Tc-99m-tetrofosmin tomographic imaging with an exercise-rest protocol was performed in 26 stable coronary patients and in 8 age-matched controls. Percent increase (%IR) in myocardial count during symptom-limited submaximal exercise-stress was calculated in 16 non-infarcted polar map segments and in each coronary territory by a subtraction technique with corrections for physical decay and injected tracer doses, and the results were compared with those of angiographically quantified coronary diameter stenosis (%DS). Percent IR and peak heart rate during exercise showed a positive linear correlation both in coronary territories with significant stenosis (%DS > or = 75%) and in control or nonstenotic (%DS more was identified by a %IR cutoff value of 40% with 77% sensitivity, 70% specificity, and an accuracy of 72%. In coronary territories with a %DS of less than 75%, %IR in diabetic patients was significantly lower (46+/-15%) than that in nondiabetic patients (61+/-25%). Thus, blunted exercise-related augmentation of myocardial uptake of Tc-99m-tetrofosmin correlates with the severity of coronary narrowing and diabetic state.

  12. Narrow-band single photon emission at room temperature based on a single Nitrogen-vacancy center coupled to an all-fiber-cavity

    CERN Document Server

    Albrecht, Roland; Pauly, Christoph; Mücklich, Frank; Schell, Andreas W; Engel, Philip; Schröder, Tim; Benson, Oliver; Reichel, Jakob; Becher, Christoph

    2014-01-01

    We report the realization of a device based on a single Nitrogen-vacancy (NV) center in diamond coupled to a fiber-cavity for use as single photon source (SPS). The device consists of two concave mirrors each directly fabricated on the facets of two optical fibers and a preselected nanodiamond containing a single NV center deposited onto one of these mirrors. Both, cavity in- and output are directly fiber-coupled and the emission wavelength is easily tunable by variation of the separation of the two mirrors with a piezo-electric crystal. By coupling to the cavity we achieve an increase of the spectral photon rate density by two orders of magnitude compared to free-space emission of the NV center. With this work we establish a simple all-fiber based SPS with promising prospects for the integration into photonic quantum networks.

  13. From a single encapsulated detector to the spectrometer for INTEGRAL satellite: predicting the peak-to-total ratio at high gamma-energies

    CERN Document Server

    Kshetri, Ritesh

    2012-01-01

    In two recent papers (R. Kshetri, JINST 2012 7 P04008; ibid., P07006), a probabilistic formalism was introduced to predict the response of encapsulated type composite germanium detectors like the SPI (spectrometer for INTEGRAL satellite). Predictions for the peak-to-total and peak-to-background ratios are given at 1.3 MeV for the addback mode of operation. The application of the formalism to clover germanium detector is discussed in two separate papers (R. Kshetri, JINST 2012 7 P07008; ibid., P08015). Using the basic approach developed in those papers, for the first time we present a procedure for calculating the peak-to-total ratio of the cluster detector for gamma-energies up to 8 MeV. Results are shown for both bare and suppressed detectors as well as for the single crystal and addback modes of operation. We have considered the experimental data of (i) peak-to-total ratio at 1.3 MeV, and (ii) single detector efficiency and addback factor for other energies up to 8 MeV. Using this data, an approximate metho...

  14. Angular correlation of annihilation photons in ice single crystals

    DEFF Research Database (Denmark)

    Mogensen, O. E.; Kvajic, G.; Eldrup, Morten Mostgaard

    1971-01-01

    Linear-slit angular-correlation curves were obtained at - 148 °C for the [0001], [10¯10], and [11¯20] directions in single crystals of ice. Besides the narrow central peak, pronounced narrow side peaks were also observed. They occurred at angles θ=2πℏgz/mc, where gz is the projection of reciproca...

  15. On-line spectrophotometric method for monitoring weak residual absorption of CaMoO{sub 4} single crystals near the intrinsic luminescence peak

    Energy Technology Data Exchange (ETDEWEB)

    Buzanov, O. A., E-mail: fedorov-metrology@yandex.ru [OAO Fomos-Materials (Russian Federation); Kanevskii, V. M. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Kornoukhov, V. N. [OAO Fomos-Materials (Russian Federation); Nabatov, B. V.; Nabatov, V. V.; Fedorov, V. A. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2013-11-15

    The optical and spectral characteristics of isotopically enriched Czochralski-grown {sup 40}Ca{sup 100}MoO{sub 4} single crystals have been investigated. This material is promising for detecting double neutrinoless {beta} decay. The possibility and the technique of spectrophotometric monitoring of weak residual absorption near the intrinsic luminescence peak of this scintillation material, which is designed for developing new-generation detectors of elementary particles, are considered.

  16. On-line spectrophotometric method for monitoring weak residual absorption of CaMoO4 single crystals near the intrinsic luminescence peak

    Science.gov (United States)

    Buzanov, O. A.; Kanevskii, V. M.; Kornoukhov, V. N.; Nabatov, B. V.; Nabatov, V. V.; Fedorov, V. A.

    2013-11-01

    The optical and spectral characteristics of isotopically enriched Czochralski-grown 40Ca100MoO4 single crystals have been investigated. This material is promising for detecting double neutrinoless β decay. The possibility and the technique of spectrophotometric monitoring of weak residual absorption near the intrinsic luminescence peak of this scintillation material, which is designed for developing new-generation detectors of elementary particles, are considered.

  17. Narrow ridge waveguide high power single mode 1.3-μm InAs/InGaAs ten-layer quantum dot lasers

    Directory of Open Access Journals (Sweden)

    Cao Q

    2007-01-01

    Full Text Available AbstractTen-layer InAs/In0.15Ga0.85As quantum dot (QD laser structures have been grown using molecular beam epitaxy (MBE on GaAs (001 substrate. Using the pulsed anodic oxidation technique, narrow (2 μm ridge waveguide (RWG InAs QD lasers have been fabricated. Under continuous wave operation, the InAs QD laser (2 × 2,000 μm2 delivered total output power of up to 272.6 mW at 10 °C at 1.3 μm. Under pulsed operation, where the device heating is greatly minimized, the InAs QD laser (2 × 2,000 μm2 delivered extremely high output power (both facets of up to 1.22 W at 20 °C, at high external differential quantum efficiency of 96%. Far field pattern measurement of the 2-μm RWG InAs QD lasers showed single lateral mode operation.

  18. Origin of a Raman scattering peak generated in single-walled carbon nanotubes by X-ray irradiation and subsequent thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Toshiya; Matsuda, Mitsuaki; Itoh, Chihiro, E-mail: citoh@sys.wakayama-u.ac.jp [Department of Materials Science, Wakayama University, 930 Sakaedani, Wakayama 640-8510 (Japan); Kisoda, Kenji [Department of Physics, Wakayama University, 930 Sakaedani, Wakayama 640-8510 (Japan)

    2016-08-15

    We have found that a Raman scattering (RS) peak around 1870 cm{sup −1} was produced by the annealing of the X-ray irradiated film of single-walled carbon nanotubes (SWNTs) at 450 {sup o}C. The intensity of 1870-cm{sup −1} peak showed a maximum at the probe energy of 2.3 eV for the RS spectroscopy with various probe lasers. Both the peak position and the probe-energy dependence were almost identical to those of the one-dimensional carbon chains previously reported in multi-walled carbon nanotubes. Consequently, we concluded that the 1870-cm{sup −1} peak found in the present study is attributed to carbon chains. The formation of carbon chains by the annealing at temperature lower than 500 {sup o}C is firstly reported by the present study. The carbon chains would be formed by aggregation of the interstitial carbons, which are formed as a counterpart of carbon vacancies by X-ray irradiation diffused on SWNT walls. The result indicates that the combination of X-ray irradiation and subsequent thermal annealing is a feasible tool for generating new nanostructures in SWNT.

  19. The Method of Single Peak Fourier Analysis of Measuring the Size of Mosaic Block and Microstrain by X-ray Diffraction

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The values of mosaic block size and microstrain measured by the method of Voigt function are sometimes largely erroneous and difficult to be revised. In this paper, the causes of the “hook effect” which inevitably exists in the method of Fourier analysis are explained; then the method for resolving this effect is put forward; and finally the method of hypothetical function is used to simplify the method of the Fourier analysis from multi-peak to single-peak. By introducing the parameter m, this method can not only indicate the degree of errors, but also revise them as well. It is simple, clear and able to accomplish the intricate pattern calculation quickly by the aid of computer. In the end, we argue the identity between method of the approximate function and the Fourier analysis, and give a more accurate proportional coefficient k.

  20. Are Bragg Peaks Gaussian?

    Science.gov (United States)

    Hammouda, Boualem

    2014-01-01

    It is common practice to assume that Bragg scattering peaks have Gaussian shape. The Gaussian shape function is used to perform most instrumental smearing corrections. Using Monte Carlo ray tracing simulation, the resolution of a realistic small-angle neutron scattering (SANS) instrument is generated reliably. Including a single-crystal sample with large d-spacing, Bragg peaks are produced. Bragg peaks contain contributions from the resolution function and from spread in the sample structure. Results show that Bragg peaks are Gaussian in the resolution-limited condition (with negligible sample spread) while this is not the case when spread in the sample structure is non-negligible. When sample spread contributes, the exponentially modified Gaussian function is a better account of the Bragg peak shape. This function is characterized by a non-zero third moment (skewness) which makes Bragg peaks asymmetric for broad neutron wavelength spreads. PMID:26601025

  1. Computation with narrow CTCs

    CERN Document Server

    Say, A C Cem

    2011-01-01

    We examine some variants of computation with closed timelike curves (CTCs), where various restrictions are imposed on the memory of the computer, and the information carrying capacity and range of the CTC. We give full characterizations of the classes of languages recognized by polynomial time probabilistic and quantum computers that can send a single classical bit to their own past. Such narrow CTCs are demonstrated to add the power of limited nondeterminism to deterministic computers, and lead to exponential speedup in constant-space probabilistic and quantum computation. We show that, given a time machine with constant negative delay, one can implement CTC-based computations without the need to know about the runtime beforehand.

  2. 1.2 MW peak power, all-solid-state picosecond laser with a microchip laser seed and a high gain single-passing bounce geometry amplifier

    Science.gov (United States)

    Wang, Chunhua; Shen, Lifeng; Zhao, Zhiliang; Liu, Bin; Jiang, Hongbo; Chen, Jun; Liu, Chong

    2016-11-01

    A semiconductor saturable absorber mirror (SESAM) based passively Q-switched microchip Nd:YVO4 seed laser with pulse duration of 90 ps at repetition rate of 100 kHz is amplified by single-passing a Nd:YVO4 bounce amplifier with varying seed input power from 20 μW to 10 mW. The liquid pure metal greasy thermally conductive material is used to replace the traditional thin indium foil as the thermal contact material for better heat load transfer of the Nd:YVO4 bounce amplifier. Temperature distribution at the pump surface is measured by an infrared imager to compare with the numerically simulated results. A highest single-passing output power of 11.3 W is obtained for 10 mW averaged seed power, achieving a pulse peak power of ~1.25 MW and pulse energy of ~113 μJ. The beam quality is well preserved with M2 ≤1.25. The simple configuration of this bounce laser amplifier made the system flexible, robust and cost-effective, showing attractive potential for further applications.

  3. Imperfect DNA lesion repair in the semiconservative quasispecies model: Derivation of the Hamming class equations and solution of the single-fitness peak landscape

    Science.gov (United States)

    Tannenbaum, Emmanuel; Sherley, James L.; Shakhnovich, Eugene I.

    2004-12-01

    This paper develops a Hamming class formalism for the semiconservative quasispecies equations with imperfect lesion repair, first presented and analytically solved in Y. Brumer and E.I. Shakhnovich (q-bio.GN/0403018, 2004). Starting from the quasispecies dynamics over the space of genomes, we derive an equivalent dynamics over the space of ordered sequence pairs. From this set of equations, we are able to derive the infinite sequence length form of the dynamics for a class of fitness landscapes defined by a master genome. We use these equations to solve for a generalized single-fitness-peak landscape, where the master genome can sustain a maximum number of lesions and remain viable. We determine the mean equilibrium fitness and error threshold for this class of landscapes, and show that when lesion repair is imperfect, semiconservative replication displays characteristics from both conservative replication and semiconservative replication with perfect lesion repair. The work presented here provides a formulation of the model which greatly facilitates the analysis of a relatively broad class of fitness landscapes, and thus serves as a convenient springboard into biological applications of imperfect lesion repair.

  4. Acute and chronic response to CRT in narrow QRS patients.

    Science.gov (United States)

    Donahue, Tim; Niazi, Imran; Leon, Angel; Stucky, Michael; Herrmann, Keith

    2012-04-01

    Previous studies suggest that CRT may benefit narrow QRS patients with mechanical dyssynchrony (MD). We conducted an acute and chronic study, evaluating the response of heart failure patients with a narrow QRS to cardiac resynchronization therapy (CRT). ESTEEM-CRT was a multi-center, single-arm, feasibility study that evaluated ICD-indicated, medically-optimized patients with EF ≤ 35%, NYHA class III heart failure, QRS duration <120 ms, and MD as defined by the standard deviation of time to peak systolic velocity of 12 segments (Ts-SD). Sixty-eight patients received a CRT defibrillator, exercise testing, and echo exams, and 47 of these patients underwent invasive hemodynamic testing at implant. Follow-up was at 6 and 12 months. The average maximal improvement in LV dP/dt(max) was minor (2 ± 2%). NYHA and quality of life scores were substantially improved at 6 and 12 months (P < 0.001), while exercise capacity and LV volumes were unchanged. The echo indices of MD were difficult to collect, discordant, and failed to predict clinical outcomes. ESTEEM-CRT patients with a narrow QRS and MD as defined in this study did not improve as measured by acute hemodynamics, chronic exercise performance, or reverse remodeling. These multi-center results support the notion that dyssynchrony indices are ineffective or at least require greater refinement for the selection of narrow QRS patients for CRT.

  5. Theoretical study on the ultra-narrow bandwidth tunable atomic filter with electromagnetically induced transparency

    Science.gov (United States)

    Liu, Yang; Li, Shu-qing; Feng, Zhong-ying; Liu, Xiao-fei; Gao, Jin-yue

    2016-12-01

    To obtain the weak signal light detection from the high background noise, we present a theoretical study on the ultra-narrow bandwidth tunable atomic filter with electromagnetically induced transparency. In a three-level Λ -type atomic system in the rubidium D1 line, the bandwidth of the EIT atomic filter is narrowed to ~6.5 \\text{MHz} . And the single peak transmission of the filter can be up to 86% . Moreover, the transmission wavelength can be tuned by changing the coupling light frequency. This theoretical scheme can also be applied to other alkali atomic systems.

  6. The use of NH3 to promote the production of large-diameter single-walled carbon nanotubes with a narrow (n,m) distribution.

    Science.gov (United States)

    Zhu, Zhen; Jiang, Hua; Susi, Toma; Nasibulin, Albert G; Kauppinen, Esko I

    2011-02-09

    We demonstrate here a simple and effective (n,m)-selective growth of single-walled carbon nanotubes (SWCNTs) in an aerosol floating catalyst chemical vapor deposition (CVD) process by introducing a certain amount of ammonia (NH(3)). Chiralities of carbon nanotubes produced in the presence of 500 ppm NH(3) at 880 °C are narrowly distributed around the major semiconducting (13,12) nanotube with over 90% of SWCNTs having large chiral angles in the range 20°-30°, and nearly 50% in the range 27°-29°. The developed synthesis process enables chiral-selective growth at high temperature for structurally stable carbon nanotubes with large diameters.

  7. Pre-transitional evolution of central peaks and transverse acoustic phonon branch in single crystal lead zirconate titanate with Ti concentration 0.7%

    Science.gov (United States)

    Andronikova, D. A.; Bronwald, I. A.; Burkovsky, R. G.; Leontiev, I. N.; Leontiev, N. G.; Bosak, A. A.; Filimonov, A. V.; Vakhrushev, S. B.

    2016-11-01

    Inelastic X-ray scattering measurements have been done to study the lattice dynamics in lead zirconate titanate solid solution with 0.7% of PbTiO3. The temperature evolution of central peak and low-energy transverse phonon branches has been traced. Temperature dependent in-plane transverse polarized acoustic phonon branch in direction has been revealed. The central peaks of two types have been found. The central peak at small wave vectors can be attributed to the relaxational-type soft ferroelectric mode, while the latter at Q = (1.5 -0.5 0) could be linked to the formation of M-superstructure in the intermediate ferroelectric phase.

  8. Measurements of a low temperature mechanical dissipation peak in a single layer of Ta2O5 doped with TiO2

    CERN Document Server

    Martin, I; Comtet, C; Fejer, M M; Gretarsson, A; Harry, G; Hough, J; Mackowski, J-M M; MacLaren, I; Michel, C; Montorio, J-L; Morgado, N; Nawrodt, R; Penn, S; Reid, S; Remillieux, A; Route, R; Rowan, S; Schwarz, C; Seidel, P; Vodel, W; Zimmer, A

    2008-01-01

    Thermal noise arising from mechanical dissipation in oxide coatings is a major limitation to many precision measurement systems, including optical frequency standards, high resolution optical spectroscopy and interferometric gravity wave detectors. Presented here are measurements of dissipation as a function of temperature between 7 K and 290 K in ion-beam sputtered Ta2O5 doped with TiO2, showing a loss peak at 20 K. Analysis of the peak provides the first evidence of the source of dissipation in doped Ta2O5 coatings, leading to possibilities for the reduction of thermal noise effects.

  9. Conversion factors for determining organ doses received by paediatric patients in high-resolution single slice computed tomography with narrow collimation

    Energy Technology Data Exchange (ETDEWEB)

    Seidenbusch, Michael C.; Schneider, Karl [Muenchen Univ. (Germany). Paediatric Radiology; Harder, Dietrich [Goettingen Univ. (Germany). Medical Physics and Biophysics; Regulla, Dieter F. [Helmholtz Zentrum Muenchen German Research Center for Environmental Health, Neuherberg (Germany). Research Unit Medical Radiation Physics and Diagnostics

    2014-09-01

    Estimations of organ doses D{sub T} received during computed tomographic examinations are usually performed by applying conversion factors to basic dose indicators like the computed tomography dose index (CTDI) or the dose-length-product (DLP). In addition to the existing conversion factors for beam apertures of 5 mm or 10 mm, we present new DLP-D{sub T} conversion factors adapted to high-resolution CT (HRCT) examinations of infants and young children with beam apertures of the order of 1 mm and under consideration of bow tie filtration. Calculations are performed on mathematical MIRD phantoms for an age range from 0, 1, 5, 10, 15 up to (for comparison) 30 years by adapting PCXMC, a Monte Carlo algorithm originally developed by STUK (Helsinki, Finland) for dose reconstructions in projection radiography. For this purpose, each single slice CT examination is approximated by a series of corresponding virtual planar radiographies comprising all focus positions. The transformation of CT exposure parameters into exposure parameters of the series of corresponding planar radiographies is performed by a specially developed algorithm called XCT. The DLP values are evaluated using the EGSRay code. The new method is verified at a beam aperture of 10 mm by comparison with formerly published conversion factors. We show that the higher spatial resolution leads to an enhanced DLP-D{sub T} conversion factor if a small organ (e.g. thyroid gland, mammae, uterus, ovaries, testes) is exactly met by the chosen CT slice, while the conversion factor is drastically reduced if the chosen CT slice is positioned above or below the organ. This effect is utilized for dose-saving examinations with only a few single slices instead a full scan, which technique is applied in about 10% of all paediatric chest CT examinations. (orig.)

  10. Narrow linewidth pulsed optical parametric oscillator

    Indian Academy of Sciences (India)

    S Das

    2010-11-01

    Tunable narrow linewidth radiation by optical parametric oscillation has many applications, particularly in spectroscopic investigation. In this paper, different techniques such as injection seeding, use of spectral selecting element like grating, grating and etalon in combination, grazing angle of incidence, entangled cavity configuration and type-II phase matching have been discussed for generating tunable narrow linewidth radiation by singly resonant optical parametric oscillation process.

  11. Facility Location with Double-peaked Preferences

    DEFF Research Database (Denmark)

    Filos-Ratsikas, Aris; Li, Minming; Zhang, Jie

    2015-01-01

    We study the problem of locating a single facility on a real line based on the reports of self-interested agents, when agents have double-peaked preferences, with the peaks being on opposite sides of their locations. We observe that double-peaked preferences capture real-life scenarios and thus...... complement the well-studied notion of single-peaked preferences. We mainly focus on the case where peaks are equidistant from the agents’ locations and discuss how our results extend to more general settings. We show that most of the results for single-peaked preferences do not directly apply to this setting...

  12. Jihadism, Narrow and Wide

    DEFF Research Database (Denmark)

    Sedgwick, Mark

    2015-01-01

    The term “jihadism” is popular, but difficult. It has narrow senses, which are generally valuable, and wide senses, which may be misleading. This article looks at the derivation and use of “jihadism” and of related terms, at definitions provided by a number of leading scholars, and at media usage....... It distinguishes two main groups of scholarly definitions, some careful and narrow, and some appearing to match loose media usage. However, it shows that even these scholarly definitions actually make important distinctions between jihadism and associated political and theological ideology. The article closes...

  13. Broad Diphotons from Narrow States

    CERN Document Server

    An, Haipeng; Zhang, Yue

    2015-01-01

    ATLAS and CMS have each reported a modest diphoton excess consistent with the decay of a broad resonance at ~ 750 GeV. We show how this signal can arise in a weakly coupled theory comprised solely of narrow width particles. In particular, if the decaying particle is produced off-shell, then the associated diphoton resonance will have a broad, adjustable width. We present simplified models which explain the diphoton excess through the three-body decay of a scalar or fermion. Our minimal ultraviolet completion is a weakly coupled and renormalizable theory of a singlet scalar plus a heavy vector-like quark and lepton. The smoking gun of this mechanism is an asymmetric diphoton peak recoiling against missing transverse energy, jets, or leptons.

  14. Correlates of Narrow Bracketing

    DEFF Research Database (Denmark)

    Koch, Alexander; Nafziger, Julia

    We examine whether different phenomena of narrow bracketing can be traced back to some common characteristic and whether and how different phenomena are related. We find that making dominated lottery choices or ignoring the endowment when making risky choices are related phenomena and are both as...

  15. Impact Crater with Peak

    Science.gov (United States)

    2002-01-01

    (Released 14 June 2002) The Science This THEMIS visible image shows a classic example of a martian impact crater with a central peak. Central peaks are common in large, fresh craters on both Mars and the Moon. This peak formed during the extremely high-energy impact cratering event. In many martian craters the central peak has been either eroded or buried by later sedimentary processes, so the presence of a peak in this crater indicates that the crater is relatively young and has experienced little degradation. Observations of large craters on the Earth and the Moon, as well as computer modeling of the impact process, show that the central peak contains material brought from deep beneath the surface. The material exposed in these peaks will provide an excellent opportunity to study the composition of the martian interior using THEMIS multi-spectral infrared observations. The ejecta material around the crater can is well preserved, again indicating relatively little modification of this landform since its initial creation. The inner walls of this approximately 18 km diameter crater show complex slumping that likely occurred during the impact event. Since that time there has been some downslope movement of material to form the small chutes and gullies that can be seen on the inner crater wall. Small (50-100 m) mega-ripples composed of mobile material can be seen on the floor of the crater. Much of this material may have come from the walls of the crater itself, or may have been blown into the crater by the wind. The Story When a meteor smacked into the surface of Mars with extremely high energy, pow! Not only did it punch an 11-mile-wide crater in the smoother terrain, it created a central peak in the middle of the crater. This peak forms kind of on the 'rebound.' You can see this same effect if you drop a single drop of milk into a glass of milk. With craters, in the heat and fury of the impact, some of the land material can even liquefy. Central peaks like the one

  16. Ultrabroadband single-cycle terahertz pulses with peak fields of 300 kV cm-1 from a metallic spintronic emitter

    Science.gov (United States)

    Seifert, T.; Jaiswal, S.; Sajadi, M.; Jakob, G.; Winnerl, S.; Wolf, M.; Kläui, M.; Kampfrath, T.

    2017-06-01

    We explore the capabilities of metallic spintronic thin-film stacks as a source of intense and broadband terahertz electromagnetic fields. For this purpose, we excite a W/CoFeB/Pt trilayer (thickness of 5.6 nm) on a large-area glass substrate (diameter of 7.5 cm) by a femtosecond laser pulse (energy 5.5 mJ, duration 40 fs, and wavelength 800 nm). After focusing, the emitted terahertz pulse is measured to have a duration of 230 fs, a peak field of 300 kV cm-1, and an energy of 5 nJ. In particular, the waveform exhibits a gapless spectrum extending from 1 to 10 THz at 10% of its amplitude maximum, thereby facilitating nonlinear control over matter in this difficult-to-reach frequency range on the sub-picosecond time scale.

  17. PeakWorks

    Energy Technology Data Exchange (ETDEWEB)

    2016-11-30

    The PeakWorks software is designed to assist in the quantitative analysis of atom probe tomography (APT) generated mass spectra. Specifically, through an interactive user interface, mass peaks can be identified automatically (defined by a threshold) and/or identified manually. The software then provides a means to assign specific elemental isotopes (including more than one) to each peak. The software also provides a means for the user to choose background subtraction of each peak based on background fitting functions, the choice of which is left to the users discretion. Peak ranging (the mass range over which peaks are integrated) is also automated allowing the user to chose a quantitative range (e.g. full-widthhalf- maximum). The software then integrates all identified peaks, providing a background-subtracted composition, which also includes the deconvolution of peaks (i.e. those peaks that happen to have overlapping isotopic masses). The software is also able to output a 'range file' that can be used in other software packages, such as within IVAS. A range file lists the peak identities, the mass range of each identified peak, and a color code for the peak. The software is also able to generate 'dummy' peak ranges within an outputted range file that can be used within IVAS to provide a means for background subtracted proximity histogram analysis.

  18. Magneto-transport through single-molecule magnets: Kondo-peaks, zero-bias dips, molecular symmetry and Berry's phase

    Energy Technology Data Exchange (ETDEWEB)

    Wegewijs, Maarten R [Institut fuer Theoretische Physik-Lehrstuhl A, RWTH Aachen, 52056 Aachen (Germany); Romeike, Christian [Institut fuer Theoretische Physik-Lehrstuhl A, RWTH Aachen, 52056 Aachen (Germany); Schoeller, Herbert [Institut fuer Theoretische Physik-Lehrstuhl A, RWTH Aachen, 52056 Aachen (Germany); Hofstetter, Walter [Institut fuer Theoretische Physik, J W Goethe-Universitaet Frankfurt, 60438 Frankfurt (Germany)

    2007-09-15

    We theoretically analyse coherent electron transport through a single-molecule magnet (SMM) in the regime where charge fluctuations are suppressed. Using the numerical renormalization group (NRG) technique, we calculate the low-temperature conductance as a function of the SMMs magnetic anisotropy parameters and the strength and orientation of an external magnetic field. We show how the microscopic magnetic symmetry of the molecule affects the transport via a Kondo effect with non-trivial dependence on a longitudinal field. In addition, we show how Berry's phase and the Kondo effect, both associated with reversal of the SMMs spin, appear when both the magnetic field amplitude and direction are varied. It is shown that both effects involve the magnetic excitations of the SMM in an essential way.

  19. Paniek over Peak Food

    NARCIS (Netherlands)

    Koning, N.B.J.

    2015-01-01

    Het kon niet uitblijven. De groei van de voedselproductie stagneert en na Peak Oil dreigt nu Peak Food. Onzin, vindt Niek Koning, die zogenaamde peak is een van de toppen in een langjarige golfbeweging op de landbouwmarkten. Toch zijn er genoeg redenen om je zorgen te maken over de wereldvoedselvoor

  20. Cryogenic Detectors (Narrow Field Instruments)

    Science.gov (United States)

    Hoevers, H.; Verhoeve, P.

    Two cryogenic imaging spectrometer arrays are currently considered as focal plane instruments for XEUS. The narrow field imager 1 (NFI 1) will cover the energy range from 0.05 to 3 keV with an energy resolution of 2 eV, or better, at 500 eV. A second narrow field imager (NFI 2) covers the energy range from 1 to 15 keV with an energy resolution of 2 eV (at 1 keV) and 5 eV (at 7 keV), creating some overlap with part of the NFI 1 energy window. Both narrow field imagers have a 0.5 arcmin field of view. Their imaging capabilities are matched to the XEUS optics of 2 to 5 arcsec leading to 1 arcsec pixels. The detector arrays will be cooled by a closed cycle system comprising a mechanical cooler with a base temperature of 2.5 K and either a low temperature 3He sorption pump providing the very low temperature stage and/or an Adiabatic Demagnetization Refrigerator (ADR). The ADR cooler is explicitly needed to cool the NFI 2 array. The narrow field imager 1} Currently a 48 times 48 element array of superconducting tunnel junctions (STJ) is envisaged. Its operating temperature is in the range between 30 and 350 mK. Small, single Ta STJs (20-50 mum on a side) have shown 3.5 eV (FWHM) resolution at E = 525 eV and small arrays have been successfully demonstrated (6 times 6 pixels), or are currently tested (10 times 12 pixels). Alternatively, a prototype Distributed Read-Out Imaging Device (DROID), consisting of a linear superconducting Ta absorber of 20 times 100 mum2, including a 20 times 20 mum STJ for readout at either end, has shown a measured energy resolution of 2.4 eV (FWHM) at E = 500 eV. Simulations involving the diffusion properties as well as loss and tunnel rates have shown that the performance can be further improved by slight modifications in the geometry, and that the size of the DROIDS can be increased to 0.5-1.0 mm without loss in energy resolution. The relatively large areas and good energy resolution compared to single STJs make DROIDS good candidates for the

  1. Narrow Sigma -hypernuclear states

    CERN Document Server

    Gal, A

    1980-01-01

    It is shown that the spin-isospin dependence of low-energy Sigma N to Lambda N conversion leads to substantial quenching of nuclear-matter estimates of the widths of some Sigma -hypernuclear states produced in (K/sup -/, pi ) reactions, to a level below 10 MeV. The estimated widths compare favorably with those of the Sigma -hypernuclear peaks recently observed at CERN for /sup 7/Li, /sup 9/Be, and /sup 12/C. Tentative quantum number assignments are suggested for these states. (10 refs).

  2. Unusual double-peaked emission in the SDSS quasar J093201.60 + 031858.7

    Science.gov (United States)

    Barrows, R. S.; Lacy, C. H. S.; Kennefick, D.; Kennefick, J.; Seigar, M. S.

    2011-02-01

    We examine spectral properties of the SDSS quasar J093201.60 + 031858.7, in particular the presence of strong blue peaks in the Balmer emission lines offset from the narrow lines by approximately 4200 km s -1. Asymmetry in the broad central component of the H β line indicates the presence of a double-peaked emitter. However, the strength and sharpness of the blue H β and blue H γ peaks make this quasar spectrum unique among double-peaked emitters identified from SDSS spectra. We fit a disk model to the H β line and compare this object with other unusual double-peaked quasar spectra, particularly candidate binary supermassive black holes (SMBHs). Under the binary SMBH scenario, we test the applicability of a model in which a second SMBH may produce the strong blue peak in the Balmer lines of a double-peaked emitter. If there were only one SMBH, a circular, Keplerian disk model fit would be insufficient, indicating some sort of asymmetry is required to produce the strength of the blue peak. In either case, understanding the nature of the complex line emission in this object will aid in further discrimination between a single SMBH with a complex accretion disk and the actual case of a binary SMBH.

  3. Exciton absorption in narrow armchair graphene nanoribbons

    Science.gov (United States)

    Monozon, B. S.; Schmelcher, P.

    2016-11-01

    We develop an analytical approach to the exciton optical absorption for narrow gap armchair graphene nanoribbons (AGNR). We focus on the regime of dominant size quantization in combination with the attractive electron-hole interaction. An adiabatic separation of slow and fast motions leads via the two-body Dirac equation to the isolated and coupled subband approximations. Discrete and continuous exciton states are in general coupled and form quasi-Rydberg series of purely discrete and resonance type character. The corresponding oscillator strengths and widths are derived. We show that the exciton peaks are blue-shifted, become broader and increase in magnitude upon narrowing the ribbon. At the edge of a subband the singularity related to the 1D density of states is transformed into finite absorption via the presence of the exciton. Our analytical results are in good agreement with those obtained by other methods including numerical approaches. Estimates of the expected experimental values are provided for realistic AGNR.

  4. Narrow, duplicated internal auditory canal

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, T. [Servico de Neurorradiologia, Hospital Garcia de Orta, Avenida Torrado da Silva, 2801-951, Almada (Portugal); Shayestehfar, B. [Department of Radiology, UCLA Oliveview School of Medicine, Los Angeles, California (United States); Lufkin, R. [Department of Radiology, UCLA School of Medicine, Los Angeles, California (United States)

    2003-05-01

    A narrow internal auditory canal (IAC) constitutes a relative contraindication to cochlear implantation because it is associated with aplasia or hypoplasia of the vestibulocochlear nerve or its cochlear branch. We report an unusual case of a narrow, duplicated IAC, divided by a bony septum into a superior relatively large portion and an inferior stenotic portion, in which we could identify only the facial nerve. This case adds support to the association between a narrow IAC and aplasia or hypoplasia of the vestibulocochlear nerve. The normal facial nerve argues against the hypothesis that the narrow IAC is the result of a primary bony defect which inhibits the growth of the vestibulocochlear nerve. (orig.)

  5. Are narrow mesons, baryons and dibaryons evidence for multiquark states?

    Energy Technology Data Exchange (ETDEWEB)

    Tatischeff, B.; Yonnet, J. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire

    2000-07-01

    Several narrow structures have been progressively observed since the last fifteen years, in di-baryonic invariant mass spectra or in missing mass spectra. More recently, narrow structures were observed in baryonic and now in mesonic mass spectra. Since these small peaks appear at fixed masses, independently of the experiment, they are associated with real states. There is no room to explain these states within classical nuclear physics taking into account baryonic and mesonic degrees of freedom. An interpretation is proposed, which associate these narrow structures with two coloured quark clusters. (authors)

  6. Peak Experience Project

    Science.gov (United States)

    Scott, Daniel G.; Evans, Jessica

    2010-01-01

    This paper emerges from the continued analysis of data collected in a series of international studies concerning Childhood Peak Experiences (CPEs) based on developments in understanding peak experiences in Maslow's hierarchy of needs initiated by Dr Edward Hoffman. Bridging from the series of studies, Canadian researchers explore collected…

  7. Peak Experience Project

    Science.gov (United States)

    Scott, Daniel G.; Evans, Jessica

    2010-01-01

    This paper emerges from the continued analysis of data collected in a series of international studies concerning Childhood Peak Experiences (CPEs) based on developments in understanding peak experiences in Maslow's hierarchy of needs initiated by Dr Edward Hoffman. Bridging from the series of studies, Canadian researchers explore collected…

  8. The central peak revisited

    Energy Technology Data Exchange (ETDEWEB)

    Shirane, G.

    1995-10-27

    The central peak in SrTiO{sub 3} was first observed by Riste and his collaborators in 1971. This was one of the key discoveries leading to an understanding of the dynamics of phase transitions. The most recent discovery of two length scales in SrTiO{sub 3} motivated a reinvestigation of the soft phonon and associated central peak by neutron scattering. These recent experiments shed new light on the nature of the central peak. It is now well established to be strongly sample dependent and it originates from defects in bulk crystals.

  9. Pikes Peak, Colorado

    Science.gov (United States)

    Brunstein, Craig; Quesenberry, Carol; Davis, John; Jackson, Gene; Scott, Glenn R.; D'Erchia, Terry D.; Swibas, Ed; Carter, Lorna; McKinney, Kevin; Cole, Jim

    2006-01-01

    For 200 years, Pikes Peak has been a symbol of America's Western Frontier--a beacon that drew prospectors during the great 1859-60 Gold Rush to the 'Pikes Peak country,' the scenic destination for hundreds of thousands of visitors each year, and an enduring source of pride for cities in the region, the State of Colorado, and the Nation. November 2006 marks the 200th anniversary of the Zebulon M. Pike expedition's first sighting of what has become one of the world's most famous mountains--Pikes Peak. In the decades following that sighting, Pikes Peak became symbolic of America's Western Frontier, embodying the spirit of Native Americans, early explorers, trappers, and traders who traversed the vast uncharted wilderness of the Western Great Plains and the Southern Rocky Mountains. High-quality printed paper copies of this poster are available at no cost from Information Services, U.S. Geological Survey (1-888-ASK-USGS).

  10. Peak Oil, Peak Coal and Climate Change

    Science.gov (United States)

    Murray, J. W.

    2009-05-01

    Research on future climate change is driven by the family of scenarios developed for the IPCC assessment reports. These scenarios create projections of future energy demand using different story lines consisting of government policies, population projections, and economic models. None of these scenarios consider resources to be limiting. In many of these scenarios oil production is still increasing to 2100. Resource limitation (in a geological sense) is a real possibility that needs more serious consideration. The concept of 'Peak Oil' has been discussed since M. King Hubbert proposed in 1956 that US oil production would peak in 1970. His prediction was accurate. This concept is about production rate not reserves. For many oil producing countries (and all OPEC countries) reserves are closely guarded state secrets and appear to be overstated. Claims that the reserves are 'proven' cannot be independently verified. Hubbert's Linearization Model can be used to predict when half the ultimate oil will be produced and what the ultimate total cumulative production (Qt) will be. US oil production can be used as an example. This conceptual model shows that 90% of the ultimate US oil production (Qt = 225 billion barrels) will have occurred by 2011. This approach can then be used to suggest that total global production will be about 2200 billion barrels and that the half way point will be reached by about 2010. This amount is about 5 to 7 times less than assumed by the IPCC scenarios. The decline of Non-OPEC oil production appears to have started in 2004. Of the OPEC countries, only Saudi Arabia may have spare capacity, but even that is uncertain, because of lack of data transparency. The concept of 'Peak Coal' is more controversial, but even the US National Academy Report in 2007 concluded only a small fraction of previously estimated reserves in the US are actually minable reserves and that US reserves should be reassessed using modern methods. British coal production can be

  11. Peak of Achievement

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    China’s first inland research station on the highest peak of Antarctic progresses smoothly China will complete the construction of its first inland Antarctic research station at Dome A,the highest polar icecap peak at 4,093 meters above sea level,next year,according to a south pole scientist involved in the project. "The preparatory work for the new sta-

  12. Narrowing the field

    DEFF Research Database (Denmark)

    Knudsen, Bo Nissen

    .danmarksstednavne.dk and obviously draws heavily on the printed edition. But the century-long effort of publishing in printed form has spawned a series of challenges to a strict database integration; first of all variations in microstructure making the parsing into information categories (i.e. database fields) quite difficult....... As of now, no less than 45 different database fields have been found necessary to structure the information found in a single place-name entry – some fields mandatory, some nonmandatory. And using a relational database structure, some fields have multiple occurrences within one entry (i.e. multiple source...... forms for one entry a.s.f.). Having made the conscious decision to split up the information into so many categories (i.e. fields) – instead of employing a broad 'other information' field – sophisticated algorithms have been developed in order to identify information category from typographical...

  13. C/NOFS Satellite Electric Field and Plasma Density Observations of Plasma Instabilities Below the Equatorial F-Peak -- Evidence for Approximately 500 km-Scale Spread-F "Precursor" Waves Driven by Zonal Shear Flow and km-Scale, Narrow-Banded Irregularities

    Science.gov (United States)

    Pfaff, R.; Freudenreich, H.; Klenzing, J.; Liebrecht, C.; Valladares, C.

    2011-01-01

    As solar activity has increased, the ionosphere F-peak has been elevated on numerous occasions above the C/NOFS satellite perigee of 400km. In particular, during the month of April, 2011, the satellite consistently journeyed below the F-peak whenever the orbit was in the region of the South Atlantic anomaly after sunset. During these passes, data from the electric field and plasma density probes on the satellite have revealed two types of instabilities which had not previously been observed in the C/NOFS data set (to our knowledge): The first is evidence for 400-500km-scale bottomside "undulations" that appear in the density and electric field data. In one case, these large scale waves are associated with a strong shear in the zonal E x B flow, as evidenced by variations in the meridional (outward) electric fields observed above and below the F-peak. These undulations are devoid of smaller scale structures in the early evening, yet appear at later local times along the same orbit associated with fully-developed spread-F with smaller scale structures. This suggests that they may be precursor waves for spread-F, driven by a collisional shear instability, following ideas advanced previously by researchers using data from the Jicamarca radar. A second new result (for C/NOFS) is the appearance of km-scale irregularities that are a common feature in the electric field and plasma density data that also appear when the satellite is below the F -peak at night. The vector electric field instrument on C/NOFS clearly shows that the electric field component of these waves is strongest in the zonal direction. These waves are strongly correlated with simultaneous observations of plasma density oscillations and appear both with, and without, evidence of larger-scale spread-F depletions. These km-scale, quasi-coherent waves strongly resemble the bottomside, sinusoidal irregularities reported in the Atmosphere Explorer satellite data set by Valladares et al. [JGR, 88, 8025, 1983

  14. C/NOFS Satellite Electric Field and Plasma Density Observations of Plasma Instabilities Below the Equatorial F-Peak -- Evidence for ~500 km-scale Spread-F "Precursor" Waves Driven by Zonal Shear Flow and km-Scale, Narrow-Banded Irregularities

    Science.gov (United States)

    Pfaff, R. F.; Freudenreich, H. T.; Klenzing, J. H.; Liebrecht, M. C.; Valladares, C. E.

    2011-12-01

    As solar activity has increased, the ionosphere F-peak has been elevated on numerous occasions above the C/NOFS satellite perigee of 400km. In particular, during the month of April, 2011, the satellite consistently journeyed below the F-peak whenever the orbit was in the region of the South Atlantic anomaly after sunset. During these passes, data from the electric field and plasma density probes on the satellite have revealed two types of instabilities which had not previously been observed in the C/NOFS data set (to our knowledge): The first is evidence for 400-500km-scale bottomside "undulations" that appear in the density and electric field data. In one case, these large scale waves are associated with a strong shear in the zonal E x B flow, as evidenced by variations in the meridional (outward) electric fields observed above and below the F-peak. These undulations are devoid of smaller scale structures in the early evening, yet appear at later local times along the same orbit associated with fully-developed spread-F with smaller scale structures. This suggests that they may be precursor waves for spread-F, driven by a collisional shear instability, following ideas advanced previously by researchers using data from the Jicamarca radar. A second new result (for C/NOFS) is the appearance of km-scale irregularities that are a common feature in the electric field and plasma density data that also appear when the satellite is below the F-peak at night. The vector electric field insrument on C/NOFS clearly shows that the electric field component of these waves is strongest in the zonal direction. These waves are strongly correlated with simultaneous observations of plasma density oscillations and appear both with, and without, evidence of larger-scale spread-F depletions. These km-scale, quasi-coherent waves strongly resemble the bottomside, sinusoidal irregularities reported in the Atmosphere Explorer satellite data set by Valladares et al. [JGR, 88, 8025, 1983]. We

  15. 人眼安全高重频窄脉宽单模全光纤激光器特性研究%Characteristics of eye-safe high repetition frequency narrow pulse width single mode all fiber laser

    Institute of Scientific and Technical Information of China (English)

    张鑫; 刘源; 贺岩; 杨燕; 侯霞; 陈卫标

    2015-01-01

    介绍了基于主振荡功率放大结构的人眼安全全光纤激光器。首先对比了电光调制及直接调制产生的种子激光在百kHz重复频率、纳秒级脉冲宽度的激光放大器中优缺点,综合系统需求选择直接调制方式;之后对窄脉冲单模放大中出现的脉冲分裂现象进行了研究,选用10μm纤芯的双包层铒镱共掺光纤,仅通过两级放大即获得了1550 nm,重复频率为200 kHz,脉冲宽度为4.07 ns,峰值功率为1.02 kW的单模激光输出。具有结构紧凑、稳定可靠的特点,可用于三维视频激光雷达。%An eye-safe, all fiber, single mode, fiber laser based on master oscillator power amplifier configuration was presented. The advantages and disadvantages were compared between using a directly modulated diode laser and an electro-optical modulated continuous-wave diode as seed laser in sub-Mega Hertz, nanosecond fiber amplifier. The main restriction of power scaling in nanosecond fiber laser was pulse split. 10μm core double cladding erbium ytterbium co-doped fiber was employed as gain fiber of power amplifier. The directly modulated seed laser was then amplified by only two stage amplifiers. Finally, a peak power of 1.02 kW with 4.07 ns pulse duration at 200 kHz pulse repetition frequency with single-mode output was obtained and it is applicable in three dimensional video imaging lidar system.

  16. Correlation-Peak Imaging

    Science.gov (United States)

    Ziegler, A.; Metzler, A.; Köckenberger, W.; Izquierdo, M.; Komor, E.; Haase, A.; Décorps, M.; von Kienlin, M.

    1996-08-01

    Identification and quantitation in conventional1H spectroscopic imagingin vivois often hampered by the small chemical-shift range. To improve the spectral resolution of spectroscopic imaging, homonuclear two-dimensional correlation spectroscopy has been combined with phase encoding of the spatial dimensions. From the theoretical description of the coherence-transfer signal in the Fourier-transform domain, a comprehensive acquisition and processing strategy is presented that includes optimization of the width and the position of the acquisition windows, matched filtering of the signal envelope, and graphical presentation of the cross peak of interest. The procedure has been applied to image the spatial distribution of the correlation peaks from specific spin systems in the hypocotyl of castor bean (Ricinus communis) seedlings. Despite the overlap of many resonances, correlation-peak imaging made it possible to observe a number of proton resonances, such as those of sucrose, β-glucose, glutamine/glutamate, lysine, and arginine.

  17. Powerful narrow linewidth random fiber laser

    Science.gov (United States)

    Ye, Jun; Xu, Jiangming; Zhang, Hanwei; Zhou, Pu

    2017-03-01

    In this paper, we demonstrate a narrow linewidth random fiber laser, which employs a tunable pump laser to select the operating wavelength for efficiency optimization, a narrow-band fiber Bragg grating (FBG) and a section of single mode fiber to construct a half-open cavity, and a circulator to separate pump light input and random lasing output. Spectral linewidth down to 42.31 GHz is achieved through filtering by the FBG. When 8.97 W pump light centered at the optimized wavelength 1036.5 nm is launched into the half-open cavity, 1081.4 nm random lasing with the maximum output power of 2.15 W is achieved, which is more powerful than the previous reported results.

  18. Peak-interviewet

    DEFF Research Database (Denmark)

    Raalskov, Jesper; Warming-Rasmussen, Bent

    Peak-interviewet er en særlig effektiv metode til at gøre ubevidste menneskelige ressourcer bevidste. Fokuspersonen (den interviewede) interviewes om en selvvalgt, personlig succesoplevelse. Terapeuten/coachen (intervieweren) spørger ind til processen, som ledte hen til denne succes. Herved afdæk...

  19. Peak-interviewet

    DEFF Research Database (Denmark)

    Raalskov, Jesper; Warming-Rasmussen, Bent

    Peak-interviewet er en særlig effektiv metode til at gøre ubevidste menneskelige ressourcer bevidste. Fokuspersonen (den interviewede) interviewes om en selvvalgt, personlig succesoplevelse. Terapeuten/coachen (intervieweren) spørger ind til processen, som ledte hen til denne succes. Herved afdæk...

  20. PULSED KGd(WO42 RAMAN LASER: TOWARDS EMISSION LINEWIDTH NARROWING

    Directory of Open Access Journals (Sweden)

    V. G. Savitski

    2015-01-01

    Full Text Available The linewidth of a KGd(WO42 pulsed Raman laser is analysed experimentally for different configurations of the Raman and pump resonators: with narrow and broadband pump emission profiles, with and without linewidth narrowing elements in the Raman laser resonator, with and without injection seeding into the Raman cavity. The benefits of a narrow linewidth pump source in combination with linewidth narrowing elements in the Raman laser cavity for the efficient linewidth narrowing of the Raman emission are explained. 20 kW peak-power pulses at 1156 nm with 0,43 cm -1 emission linewidth are demonstrated from an injection seeded KGW Raman laser. 

  1. On the trail of double peak hydrographs

    Science.gov (United States)

    Martínez-Carreras, Núria; Hissler, Christophe; Gourdol, Laurent; Klaus, Julian; Juilleret, Jérôme; François Iffly, Jean; McDonnell, Jeffrey J.; Pfister, Laurent

    2016-04-01

    A double peak hydrograph features two peaks as a response to a unique rainfall pulse. The first peak occurs at the same time or shortly after the precipitation has started and it corresponds to a fast catchment response to precipitation. The delayed peak normally starts during the recession of the first peak, when the precipitation has already ceased. Double peak hydrographs may occur for various reasons. They can occur (i) in large catchments when lag times in tributary responses are large, (ii) in urban catchments where the first peak is often caused by direct surface runoff on impervious land cover, and the delayed peak to slower subsurface flow, and (iii) in non-urban catchments, where the first and the delayed discharge peaks are explained by different runoff mechanisms (e.g. overland flow, subsurface flow and/or deep groundwater flow) that have different response times. Here we focus on the third case, as a formal description of the different hydrological mechanisms explaining these complex hydrological dynamics across catchments with diverse physiographic characteristics is still needed. Based on a review of studies documenting double peak events we have established a formal classification of catchments presenting double peak events based on their regolith structure (geological substratum and/or its weathered products). We describe the different hydrological mechanisms that trigger these complex hydrological dynamics across each catchment type. We then use hydrometric time series of precipitation, runoff, soil moisture and groundwater levels collected in the Weierbach (0.46 km2) headwater catchment (Luxembourg) to better understand double peak hydrograph generation. Specifically, we aim to find out (1) if the generation of a double peak hydrograph is a threshold process, (2) if the hysteretic relationships between storage and discharge are consistent during single and double peak hydrographs, and (3) if different functional landscape units (the hillslopes

  2. Temperature Dependence of Photoluminescence from Single and Ensemble InAs/GaAs Quantum Dots

    Institute of Scientific and Technical Information of China (English)

    DOU Xiu-Ming; SUN Bao-Quan; XIONG Yong-Hua; HUANG She-Song; NI Hai-Qiao; NIU Zhi-Chuan

    2008-01-01

    We investigate the temperature dependence of photoluminescence from single and ensemble InAs/GaAs quantum dots systematically. As temperature increases, the exciton emission peak for single quantum dot shows broadening and redshift. For ensemble quantum dots, however, the exciton emission peak shows narrowing and fast redshift.We use a simple steady-state rate equation model to simulate the experimental data of photoluminescence spectra.It is confirmed that carrier-phonon scattering gives the broadening of the exciton emission peak in single quantum dots while the effects of carrier thermal escape and retrapping play an important role in the narrowing and fast redshift of the exciton emission peak in ensemble quantum dots.

  3. Temperature evolution of central peaks and effect of electric field in relaxor ferroelectric 0.83Pb(Mg1/3Nb2/3)O3–0.17PbTiO3 single crystals

    Science.gov (United States)

    Helal, Md Al; Aftabuzzaman, Md; Svirskas, Sarunas; Banys, Juras; Kojima, Seiji

    2017-10-01

    Relaxor ferroelectric 0.83Pb(Mg1/3Nb2/3)O3–0.17PbTiO3 (PMN–17PT) single crystals were studied by Brillouin scattering to investigate the role of polar nanoregions (PNRs) with intermediate random fields (RFs). Upon cooling, the central peak began to appear at the Burns temperature (T B) of ∼600 K, indicating the existence of polarization relaxations induced by PNRs. The fitting performed using the equation of stretched slowing down at the inverse relaxation time revealed that the slowing down of PNRs was suppressed in PMN–17PT compared with that in PMN–56PT owing to the increase in the strength of RFs. At room temperature, the splitting of the longitudinal acoustic mode at 1.6 kV/cm was observed owing to the coexistence of the macrodomain formed by the external electric field along the [100] axis and the nanodomains formed by RFs. The appearance of the transverse acoustic mode at 3.2 kV/cm indicates the field-induced rhombohedral-to-tetragonal phase.

  4. Narrow linewidth emissions from organic crystals with diffraction gratings engraved directly on their surface (Conference Presentation)

    Science.gov (United States)

    Yamamoto, Hiroyuki; Yamao, Takeshi; Hotta, Shu

    2016-10-01

    grating period on the P6T crystal by engraving 400 grooves, and succeeded in observing strong single peak at 629 nm. Using the present method, we can design the diffraction grating periods for the optical devices of organic oligomer crystals that show the narrow linewidth emissions.

  5. 矩形窄缝通道内单相水流动特性研究%Research on Characteristics of Single-Phase Water Flow in Narrow Rectangular Channel

    Institute of Scientific and Technical Information of China (English)

    幸奠川; 阎昌琪; 曹夏昕; 刘宇生; 谢清清

    2011-01-01

    A calculation formulation for laminar friction coefficient in narrow rectangular channel was obtained by theoretical analysis. Experiments have been made on flow characteristics in narrow rectangular channels with low aspect ratios, and the results show that the curve of friction coefficients in rectangular channel varying with Reynolds number is similar to that in round pipe. The conventional frictional correlations based on circular pipes are not available for rectangular channels, which depend on Reynolds numbers and aspect ratios, and the friction coefficient increases as the aspect ratio decreases. The experimental results agree well with the theoretical analysis. The effects of aspect ratios on frictional characteristics in laminar flow were explained by taking into account wetting perimeter and shear stress.%通过理论分析,得到了计算矩形窄缝通道单相层流摩阻系数的公式.对小高宽比矩形窄缝通道内的流动特性进行了实验研究,结果表明:矩形窄缝通道内单相摩阻系数随Re变化的曲线和圆管有相同的趋势,但圆管流动摩阻公式不适用于矩形窄缝通道.矩形通道内摩阻系数与Re和通道截面高宽比有关,通道高宽比越小,摩阻系数越大.实验结果和理论推导结论一致.从截面湿周和切向应力两方面解释了高宽比对矩形窄缝通道内单相水层流摩阻特性的影响机理.

  6. Kinetic narrowing of size distribution

    Science.gov (United States)

    Dubrovskii, V. G.

    2016-05-01

    We present a model that reveals an interesting possibility for narrowing the size distribution of nanostructures when the deterministic growth rate changes its sign from positive to negative at a certain stationary size. Such a behavior occurs in self-catalyzed one-dimensional III-V nanowires and more generally whenever a negative "adsorption-desorption" term in the growth rate is compensated by a positive "diffusion flux." By asymptotically solving the Fokker-Planck equation, we derive an explicit representation for the size distribution that describes either Poissonian broadening or self-regulated narrowing depending on the parameters. We show how the fluctuation-induced spreading of the size distribution can be completely suppressed in systems with size self-stabilization. These results can be used for obtaining size-uniform ensembles of different nanostructures.

  7. Focal F0 peak shape and sentence mode in Swedish

    DEFF Research Database (Denmark)

    Ambrazaitis, Gilbert; Buanzur, Tuarik C.; Niebuhr, Oliver

    2015-01-01

    Shape characteristics of rising-falling accentual F0 peaks of Stockholm Swedish Accent I words in narrow focus are studied in a corpus of 287 read sentences. The corpus includes statements and three types of polar questions. Results reveal a clear effect of sentence mode on the shape of the accen...

  8. "Credit Markets and Narrow Banking"

    OpenAIRE

    Ronnie Phillips

    1992-01-01

    Maurice Allais's view that the credit created by fractional reserve banking is equivalent to counterfeiting has led him to recommend the separation of the depository and lending functions of banks. This proposal has recently been reintroduced by James Tobin and others under the term "narrow banking." Proponents cite the potential for enhanced safety of the payments mechanism and the elimination of costs associated with the preses system of Federal deposit insurance. This plan resembles the "1...

  9. Geyser Peak Cabernet Sauvignon

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    <正>年份:2000产地:美国加州Sonoma County售价:$196 Geyser Peak(盖世峰)成立于1880年,是美国军有的过百岁葡萄酒庄。可惜美国酿制葡萄酒的技术在近三四十年才有突破,历史再悠久也没有太多帮助近二十年Geyser Peak就努力改进,希望迎头赶上其它加州新秀的水平,1989年,他们就聘请了澳洲Penfolds酒庄的酿酒师Daryl Groom,让旗下出品多了一份澳洲式的"霎眼娇"风格。2003年,Geyser Peak更在International Wine & Spirit Competition赢得"最佳美国葡萄酒生产商"大奖。

  10. Nasal base narrowing: the alar flap advancement technique.

    Science.gov (United States)

    Ismail, Ahmed Soliman

    2011-01-01

    To evaluate the role of creating an alar-based advancement flap in narrowing the nasal base and correcting excessive alar flare. Case series with chart review. This is a retrospective record review study. The study included 35 cases presenting with a wide nasal base and excessive alar flaring. The surgical procedure combined the alar base reduction with alar flare excision by creating a single laterally based alar flap. Any caudal septal deformities and any nasal tip modification procedures were corrected before the nasal base narrowing. The mean follow-up period was 23 months. The mean alar flap narrowing was 6.3 mm, whereas the mean width of sill narrowing was 2.9 mm. This single laterally based advancement alar flap resulted in a more conservative external resection, thus avoiding alar wedge overresection or blunting of the alar-facial crease. No cases of postoperative bleeding, infection, or keloid were encountered, and the external alar wedge excision healed with no apparent scar that was hidden in the depth of the alar-facial crease. The risk of notching of the alar rim at the sill incision is reduced by adopting a 2-layer closure of the vestibular floor. The alar base advancement flap is an effective technique in narrowing both the nasal base and excessive alar flare. It adopts a single skin excision to correct the 2 deformities while commonly feared complications were avoided.

  11. Photoluminescence from narrow InAs-AlSb quantum wells

    Science.gov (United States)

    Brar, Berinder; Kroemer, Herbert; Ibbetson, James; English, John H.

    1993-01-01

    We report on photoluminescence spectra from narrow InAs-AlSb quantum wells. Strong, clearly resolved peaks for well widths from 2 to 8 monolayers were observed. Transmission electron micrographs show direct evidence for the structural quality of the quantum well structures. The transition energies of the narrowest wells suggest a strong influence of the AlSb X-barrier on the electronic states in the conduction band.

  12. 单面与双面加热时窄缝流道内过冷沸腾气泡行为的比较%COMPARISON OF BUBBLE BEHAVIOR FOR DOUBLE-SIDE AND SINGLE-SIDE HEATING OF SUBCOOLED FLOW BOILING IN NARROW CHANNELS

    Institute of Scientific and Technical Information of China (English)

    潘良明; 何川; 辛明道; 吴小航

    2004-01-01

    The bubble behavior of subcooled R-12 flow boiling in the narrow channels with both doubleside and single-side heating was studied experimentally. Experimental settings are: a test-section heating length of 400 ram, a cross-section of 35 mm in width and 2ram in gap size, a mass flux of 700-1500 kg ·m-2·s-1 , a heat flux of 25-70 kW · m-2 and a pressure of 1.3-2. 0 MPa. A comparison was made in terms of the onset of nucleate boiling (ONB) point and bubble characters with other flow pattern. The study found that with some appropriate modifications, the characteristics of double-side heating and single-side heating showed a better similarity.

  13. Kilowatt high average power narrow-linewidth nanosecond all-fiber laser

    Institute of Scientific and Technical Information of China (English)

    Rongtao; Su; Pu; Zhou; Xiaolin; Wang; Rumao; Tao; Xiaojun; Xu

    2014-01-01

    A high power narrow-linewidth nanosecond all-fiber laser based on the master oscillator power amplifier(MOPA)configuration is demonstrated. A pulsed seed with high repetition rate of 10 MHz was generated by modulating a continuous-wave(CW) single-frequency fiber laser at ~1064 nm by using an electro-optic intensity modulator(EOIM).After multi-stage cascaded power amplification, the average power was boosted to be kilowatt level. The pulses from the main amplifier had a pulse width of ~3 ns and an average/peak power of 913 W/28.6 kW. Further power scaling of the pulses was limited by stimulated Raman scattering(SRS) for the moment, method for SRS suppression and further power scaling was briefly discussed.

  14. The Origin of Weak Lensing Convergence Peaks

    CERN Document Server

    Liu, Jia

    2016-01-01

    Weak lensing convergence peaks are a promising tool to probe nonlinear structure evolution at late times, providing additional cosmological information beyond second-order statistics. Previous theoretical and observational studies have shown that the cosmological constraints on $\\Omega_m$ and $\\sigma_8$ are improved by a factor of up to ~ 2 when peak counts and second-order statistics are combined, compared to using the latter alone. We study the origin of lensing peaks using observational data from the 154 deg$^2$ Canada-France-Hawaii Telescope Lensing Survey. We found that while high peaks (with height $\\kappa$ >3.5 $\\sigma_\\kappa$, where $\\sigma_\\kappa$ is the r.m.s. of the convergence $\\kappa$) are typically due to one single massive halo of ~$10^{15}M_\\odot$, low peaks ($\\kappa$ ~ their virial radii), compared with ~0.25 virial radii for halos linked with high peaks, hinting that low peaks are more immune to baryonic processes whose impact is confined to the inner regions of the dark matter halos. Our fi...

  15. ASSESSING PEAK AEROBIC CAPACITY IN DUTCH LAW ENFORCEMENT OFFICERS

    NARCIS (Netherlands)

    Wittink, Harriet; Takken, Tim; de Groot, Janke; Reneman, Michiel; Peters, Roelof; Vanhees, Luc

    2015-01-01

    Objectives: To cross-validate the existing peak rate of oxygen consumption (VO2peak) prediction equations in Dutch law enforcement officers and to determine whether these prediction equations can be used to predict VO2peak for groups and in a single individual. A further objective was to report norm

  16. Driven tracers in narrow channels

    Science.gov (United States)

    Cividini, J.; Mukamel, D.; Posch, H. A.

    2017-01-01

    Steady-state properties of a driven tracer moving in a narrow two-dimensional (2D) channel of quiescent medium are studied. The tracer drives the system out of equilibrium, perturbs the density and pressure fields, and gives the bath particles a nonzero average velocity, creating a current in the channel. Three models in which the confining effect of the channel is probed are analyzed and compared in this study: the first is the simple symmetric exclusion process (SSEP), for which the stationary density profile and the pressure on the walls in the frame of the tracer are computed. We show that the tracer acts like a dipolar source in an average velocity field. The spatial structure of this 2D strip is then simplified to a one-dimensional (1D) SSEP, in which exchanges of position between the tracer and the bath particles are allowed. Using a combination of mean-field theory and exact solution in the limit where no exchange is allowed gives good predictions of the velocity of the tracer and the density field. Finally, we show that results obtained for the 1D SSEP with exchanges also apply to a gas of overdamped hard disks in a narrow channel. The correspondence between the parameters of the SSEP and of the gas of hard disks is systematic and follows from simple intuitive arguments. Our analytical results are checked numerically.

  17. Spectral Narrowing in Semiconductor Microcavities

    Science.gov (United States)

    La Rocca, G. C.; Bassani, F.; Agranovich, V. M.

    1998-03-01

    The notion of in-plane motional narrowing of cavity polariton (CP) lines has been recently considered ( D.M. Whittaker et al.), Phys. Rev. Lett. 77, 4792 (1996); V. Savona et al.. Phys. Rev. Lett. 78, 4470 (1997). We point out that, in the presence of N>1 resonating quantum wells (QWs), the exciton component in a CP is coherently delocalized over all the individual QWs. Besides the two CP branches, also a dark exciton branch is present given by N-1 states similarly delocalized, but orthogonal to the cavity photon mode. If the QW disorder potential is weak compared to the Rabi splitting, it is seen by a CP as reduced by a factor 1/√N because of averaging along the cavity axis (G.C. La Rocca, F. Bassani, V.M. Agranovich, JOSA B 15), (1998). As for the in-plane motional narrowing, a simple scaling procedure shows that it would imply that the inhomogeneous linewidth of a CP be reduced by about four orders of magnitude compared to a QW exciton, which is incompatible with the experimental observations. The physical reason of such a shortcoming is that the disorder introduces localized exciton states which can resonantly scatter CPs, mixing them with states having a large k vector as well as with dark exciton states.

  18. Peak mass and dynamical friction

    CERN Document Server

    Del Popolo, A

    1995-01-01

    We show how the results given by several authors relatively to the mass of a density peak are changed when small scale substructure induced by dynamical friction are taken into account. The peak mass obtained is compared to the result of Peacock \\& Heavens (1990) and to the peak mass when dynamical friction is absent to show how these effects conspire to reduce the mass accreted by the peak.

  19. Peak capacity in unidimensional chromatography.

    Science.gov (United States)

    Neue, Uwe Dieter

    2008-03-14

    The currently existing knowledge about peak capacity in unidimensional separations is reviewed. The majority of the paper is dedicated to reversed-phase gradient chromatography, covering specific techniques as well as the subject of peak compression. Other sections deal with peak capacity in isocratic chromatography, size-exclusion chromatography and ion-exchange chromatography. An important topic is the limitation of the separation power and the meaning of the concept of peak capacity for real applications.

  20. Measurements of a low-temperature mechanical dissipation peak in a single layer of Ta{sub 2}O{sub 5} doped with TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Martin, I; Hough, J; MacLaren, I; Reid, S; Rowan, S [SUPA, University of Glasgow, Glasgow G12 8QQ, Scotland (United Kingdom); Armandula, H [LIGO Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Comtet, C; Mackowski, J-M M; Michel, C; Montorio, J-L; Morgado, N; Remillieux, A [Laboratoire des Materiaux Avances, LMA, CNRS-IN2P3 (France); Fejer, M M; Route, R [Edward L Ginzton Laboratory, Stanford University, Stanford, CA 94305-4088 (United States); Gretarsson, A [Embry-Riddle Aeronautical University, Prescott, AZ 86301 (United States); Harry, G [LIGO Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Nawrodt, R; Schwarz, C; Seidel, P [Friedrich-Schiller University, Jena, PF 07737 Jena (Germany); Penn, S [Department of Physics, Hobart and William Smith Colleges, Geneva, New York, 14456 (United States)], E-mail: i.martin@physics.gla.ac.uk (and others)

    2008-03-07

    Thermal noise arising from mechanical dissipation in oxide coatings is a major limitation to many precision measurement systems, including optical frequency standards, high-resolution optical spectroscopy and interferometric gravity wave detectors. Presented here are measurements of dissipation as a function of temperature between 7 K and 290 K in ion-beam-sputtered Ta{sub 2}O{sub 5} doped with TiO{sub 2}, showing a loss peak at 20 K. Analysis of the peak provides the first evidence of the source of dissipation in doped Ta{sub 2}O{sub 5} coatings, leading to possibilities for the reduction of thermal noise effects.

  1. Temporal intensity interferometry for characterization of very narrow spectral lines

    Science.gov (United States)

    Tan, P. K.; Kurtsiefer, C.

    2017-08-01

    Some stellar objects exhibit very narrow spectral lines in the visible range additional to their blackbody radiation. Natural lasing has been suggested as a mechanism to explain narrow lines in Wolf-Rayet stars. However, the spectral resolution of conventional astronomical spectrographs is still about two orders of magnitude too low to test this hypothesis. We want to resolve the linewidth of narrow spectral emissions in starlight. A combination of spectral filtering with single-photon-level temporal correlation measurements breaks the resolution limit of wavelength-dispersing spectrographs by moving the linewidth measurement into the time domain. We demonstrate in a laboratory experiment that temporal intensity interferometry can determine a 20-MHz-wide linewidth of Doppler-broadened laser light and identify a coherent laser light contribution in a blackbody radiation background.

  2. CT demonstration of pharyngeal narrowing in adult obstructive sleep apnea

    Energy Technology Data Exchange (ETDEWEB)

    Bohlman, M.E. (Johns Hopkins Univ. School of Medicine, Baltimore, MD); Haponik, E.F.; Smith, P.L.; Allen, R.P.; Bleecker, E.R.; Goldman, S.M.

    1983-03-01

    Sleep apnea is a major cause of daytime hypersomnolence. Among the proposed etiologies, focal obstruction of the airways at the level of the pharynx has been suggested but not proven. Using computed tomography, the cross-sectional area of the airway can be readily assessed. Thirty-three adults with clinically proven sleep apnea and 12 normal adults underwent systematic computed tomography of the neck. Significant airway narrowing was demonstrated in all the patients with obstructive sleep apnea, whereas no such narrowing was seen in the controls. In 11, the narrowing was at a single level, whereas in 22 patients two or more levels were affected. This study has shown that a structurally abnormal airway may serve as an anatomic substrate for the development of sleep apnea. On the basis of this evidence, uvulopalatopharyngoplasty has been performed in two patients with relief of symptoms in one.

  3. Simulating the dual-peak excitation pattern produced by bipolar stimulation of a cochlear implant: effects on speech intelligibility.

    Science.gov (United States)

    Mesnildrey, Quentin; Macherey, Olivier

    2015-01-01

    Several electrophysiological and psychophysical studies have shown that the spatial excitation pattern produced by bipolar stimulation of a cochlear implant (CI) can have a dual-peak shape. The perceptual effects of this dual-peak shape were investigated using noise-vocoded CI simulations in which synthesis filters were designed to simulate the spread of neural activity produced by various electrode configurations, as predicted by a simple cochlear model. Experiments 1 and 2 tested speech recognition in the presence of a concurrent speech masker for various sets of single-peak and dual-peak synthesis filters and different numbers of channels. Similarly as results obtained in real CIs, both monopolar (MP, single-peak) and bipolar (BP + 1, dual-peak) simulations showed a plateau of performance above 8 channels. The benefit of increasing the number of channels was also lower for BP + 1 than for MP. This shows that channel interactions in BP + 1 become especially deleterious for speech intelligibility when a simulated electrode acts both as an active and as a return electrode for different channels because envelope information from two different analysis bands are being conveyed to the same spectral location. Experiment 3 shows that these channel interactions are even stronger in wide BP configuration (BP + 5), likely because the interfering speech envelopes are less correlated than in narrow BP + 1. Although the exact effects of dual- or multi-peak excitation in real CIs remain to be determined, this series of experiments suggest that multipolar stimulation strategies, such as bipolar or tripolar, should be controlled to avoid neural excitation in the vicinity of the return electrodes. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Sensor based on Fano resonances of plane metamaterial with narrow slits

    Science.gov (United States)

    Huang, Wan-Xia; Guo, Juan-Juan; Wang, Mao-Sheng; Zhao, Guo-Ren

    2017-03-01

    The optical properties of a composite metamaterial composed of narrow slits and nano hole pairs have been investigated experimentally and numerically. The strength of the transmission peak originating from the interference between the coupled surface plasmon polaritons (SPP) of the narrow slit and the SPP modes of the hole array is modulated by the degree of symmetry breaking. Some SPP modes can be inhibited by controlling the spacer layer thickness. Our metamaterial has potential applications in sensing and weak signal detection.

  5. PEAK SHAVING CONSIDERING STREAMFLOW UNCERTAINTIES

    African Journals Online (AJOL)

    user

    The main thrust of this paper is peak shaving with a Stochastic hydro model. In peak sharing, the amount of ... Fuel cost at a conventional hydro plant is nil. On the other hand, the ... s(k) = spill at the hydro plant in period k. I(k) = loss due to ...

  6. High power, picosecond green laser based on a frequency-doubled, all-fiber, narrow-bandwidth, linearly polarized, Yb-doped fiber laser

    Science.gov (United States)

    Tian, Wenyan; Isyanova, Yelena; Stegeman, Robert; Huang, Ye; Chieffo, Logan R.; Moulton, Peter F.

    2016-03-01

    We report on the development of an all-fiber, 68-kW-peak-power, 16-ps-pulse-width, narrow-bandwidth, linearly polarized, 1064-nm fiber laser suitable for high-power, picosecond-pulse-width, green-light generation. Our 1064-nm fiber laser delivered an average power of up to 110 W at a repetition of 100- MHz in a narrow bandwidth, with minimal nonlinear distortion. We developed a high-power, picosecond green source at 532 nm through use of single-pass frequency-doubling of our 1064-nm fiber laser in lithium triborate (LBO). Using a 15-mm long LBO crystal, we have generated 30 W of average power in the second harmonic with 73-W of fundamental average power, for a conversion efficiency of 41%.

  7. Anger perceptually and conceptually narrows cognitive scope.

    Science.gov (United States)

    Gable, Philip A; Poole, Bryan D; Harmon-Jones, Eddie

    2015-07-01

    For the last 50 years, research investigating the effect of emotions on scope of cognitive processing was based on models proposing that affective valence determined cognitive scope. More recently, our motivational intensity model suggests that this past work had confounded valence with motivational intensity. Research derived from this model supports the idea that motivational intensity, rather than affective valence, explains much of the variance emotions have on cognitive scope. However, the motivational intensity model is limited in that the empirical work has examined only positive affects high in approach and negative affects high in avoidance motivation. Thus, perhaps only approach-positive and avoidance-negative states narrow cognitive scope. The present research was designed to clarify these conceptual issues by examining the effect of anger, a negatively valenced approach-motivated state, on cognitive scope. Results revealed that anger narrowed attentional scope relative to a neutral state and that attentional narrowing to anger was similar to the attentional narrowing caused by high approach-motivated positive affects (Study 1). This narrowing of attention was related to trait approach motivation (Studies 2 and Study 3). Anger also narrowed conceptual cognitive categorization (Study 4). Narrowing of categorization related to participants' approach motivation toward anger stimuli. Together, these results suggest that anger, an approach-motivated negative affect, narrows perceptual and conceptual cognitive scope. More broadly, these results support the conceptual model that motivational intensity per se, rather than approach-positive and avoidance-negative states, causes a narrowing of cognitive scope.

  8. Tunable narrow band source via the strong coupling between optical emitter and nanowire surface plasmons

    CERN Document Server

    Yang, J; Niu, Y P; Qi, Y H; Zhou, F X; Gong, S Q

    2014-01-01

    The spectrum width can be narrowed to a certain degree by decreasing the coupling strength for the two-level emitter coupled to the propagating surface plasmon. But the width can not be narrowed any further because of the loss of the photon out of system by spontaneous emission from the emitter. Here we propose a new scheme to construct a narrow-band source via a one-dimensional waveguide coupling with a three-level emitter. It is shown that the reflective spectrum width can be narrowed avoiding the impact of the loss. This approach opens up the possibility of plasmonic ultranarrow single-photon source.

  9. Doppler peaks from active perturbations

    CERN Document Server

    Magueijo, J; Coulson, D; Ferreira, P; Magueijo, Joao; Albrecht, Andreas; Coulson, David; Ferreira, Pedro

    1995-01-01

    We examine how the qualitative structure of the Doppler peaks in the angular power spectrum of the cosmic microwave anisotropy depends on the fundamental nature of the perturbations which produced them. The formalism of Hu and Sugiyama is extended to treat models with cosmic defects. We discuss how perturbations can be ``active'' or ``passive'' and ``incoherent'' or ``coherent'', and show how causality and scale invariance play rather different roles in these various cases. We find that the existence of secondary Doppler peaks and the rough placing of the primary peak unambiguously reflect these basic properties.

  10. Make peak flow a habit!

    Science.gov (United States)

    ... asthma - peak flow References Durrani SR, Busse WW. Management of asthma in adolescents and adults. In: Adkinson NF Jr, Bochner BS, Burks AW, et al, eds. Middleton's Allergy Principles and Practice . 8th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap ...

  11. Ultra-narrow linewidth optical filter based on Faraday effect at isotope 87Rb 420 nm transitions

    Science.gov (United States)

    Bi, Gang; Kang, Jia; Fu, Jun; Ling, Li; Chen, Jingbiao

    2016-12-01

    An ultra-narrow linewidth optical filter with isotope 87Rb vapor at 420 nm, within the best waveband 400-500 nm for deep sea communication is achieved for the first time. The Faraday effect, circular dichroism, and nonlinear saturation techniques are utilized to narrow the bandwidth from previous 2.5 GHz to about 15 MHz level on the energy transition 5S1/2 → 6P3/2. By changing the temperature and magnetic field, the maximum transmission is obtained when the temperature and the magnetic field of the 87Rb cell are at 100 °C and 12 G. We discuss the varying influences of temperature, magnetic field, and pump power on the transmission of the atomic filter. The maximum single peak transmission at 5S1/2, F = 2 → 6P3/2, F‧ = 3 transition is 2.1% with a bandwidth of 17.8 MHz, and 1.9% at the 5S1/2, F = 2 → 6P3/2, F‧ = 2 , 3 (cross-over) transition with that of 14.2 MHz. The calculated equivalent noise bandwidth of this system is 32.5 MHz. Compared with the conventional Faraday anomalous dispersion optical filter, the bandwidth of our system is narrowed at least two orders of magnitude and is closer to the natural linewidth. This ultra-narrow linewidth filter has the potential to be applied to submarine communication or the pump laser in a four-level Rb-based active optical clock.

  12. Bright optical centre in diamond with narrow, highly polarised and nearly phonon-free fluorescence at room temperature

    Science.gov (United States)

    John, Roger; Lehnert, Jan; Mensing, Michael; Spemann, Daniel; Pezzagna, Sébastien; Meijer, Jan

    2017-05-01

    Using shallow implantation of ions and molecules with masses centred at 27 atomic mass units (amu) in diamond, a new artificial optical centre with unique properties has been created. The centre shows a linearly polarised fluorescence with a main narrow emission line mostly found at 582 nm, together with a weak vibronic sideband at room temperature. The fluorescence lifetime is ∼2 ns and the brightest centres are more than three times brighter than the nitrogen-vacancy centres. A majority of the centres shows stable fluorescence whereas some others present a blinking behaviour, at faster or slower rates. Furthermore, a second kind of optical centre has been simultaneously created in the same diamond sample, within the same ion implantation run. This centre has a narrow zero-phonon line (ZPL) at ∼546 nm and a broad phonon sideband at room temperature. Interestingly, optically detected magnetic resonance (ODMR) has been measured on several single 546 nm centres and two resonance peaks are found at 0.99 and 1.27 GHz. In view of their very similar ODMR and optical spectra, the 546 nm centre is likely to coincide with the ST1 centre, reported once (with a ZPL at 550 nm), but of still unknown nature. These new kinds of centres are promising for quantum information processing, sub-diffraction optical imaging or use as single-photon sources.

  13. Peak Oil and other threatening peaks-Chimeras without substance

    Energy Technology Data Exchange (ETDEWEB)

    Radetzki, Marian, E-mail: marian@radetzki.bi [Lulea University of Technology (Sweden)

    2010-11-15

    The Peak Oil movement has widely spread its message about an impending peak in global oil production, caused by an inadequate resource base. On closer scrutiny, the underlying analysis is inconsistent, void of a theoretical foundation and without support in empirical observations. Global oil resources are huge and expanding, and pose no threat to continuing output growth within an extended time horizon. In contrast, temporary or prolonged supply crunches are indeed plausible, even likely, on account of growing resource nationalism denying access to efficient exploitation of the existing resource wealth.

  14. Peak Oil and other threatening peaks. Chimeras without substance

    Energy Technology Data Exchange (ETDEWEB)

    Radetzki, Marian [Luleaa University of Technology (Sweden)

    2010-11-15

    The Peak Oil movement has widely spread its message about an impending peak in global oil production, caused by an inadequate resource base. On closer scrutiny, the underlying analysis is inconsistent, void of a theoretical foundation and without support in empirical observations. Global oil resources are huge and expanding, and pose no threat to continuing output growth within an extended time horizon. In contrast, temporary or prolonged supply crunches are indeed plausible, even likely, on account of growing resource nationalism denying access to efficient exploitation of the existing resource wealth. (author)

  15. Ultrasonic Transducer Peak-to-Peak Optical Measurement

    Directory of Open Access Journals (Sweden)

    Pavel Skarvada

    2012-01-01

    Full Text Available Possible optical setups for measurement of the peak-to-peak value of an ultrasonic transducer are described in this work. The Michelson interferometer with the calibrated nanopositioner in reference path and laser Doppler vibrometer were used for the basic measurement of vibration displacement. Langevin type of ultrasonic transducer is used for the purposes of Electro-Ultrasonic Nonlinear Spectroscopy (EUNS. Parameters of produced mechanical vibration have to been well known for EUNS. Moreover, a monitoring of mechanical vibration frequency shift with a mass load and sample-transducer coupling is important for EUNS measurement.

  16. 1.55 Micron High Peak Power Fiber Amplifier Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this proposal, we propose to demonstrate and build a 1.55 micron single frequency high energy and high peak power fiber amplifier by developing an innovative...

  17. 1.55 Micron High Peak Power Fiber Amplifier Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this proposal, we propose to demonstrate and build a 1.55 micron single frequency high energy and high peak power fiber amplifier by developing an innovative...

  18. Preparation and Photoemission Spectra of Rb3C60 Single-Crystal Thin Films

    Institute of Scientific and Technical Information of China (English)

    李宏年; 吴太权; 陈晓; 李海洋; 鲍世宁; 徐亚伯; 钱海杰; 易卜拉欣奎热西; 刘风琴

    2002-01-01

    Rb3 C60 single-crystal thin films were prepared on the cleaved (111) surface of C60 single crystal. The photoemission spectrum line shapes of the lowest unoccupied molecular orbital (LUMO) derived band at room temperature and 150K were established by synchrotron radiation photoemission spectrum measurements. The density of states near the Fermi level was distinctly affected by temperature. No less than six sub-peaks of the LUMOband were observed even at room temperature. The existence of so many sub-peaks offered the opportunities to analyse in more detail the orientational structure and the electron-Boson interactions of the narrow-band metallic Rb3 C60 .

  19. Significance Tests for Periodogram Peaks

    CERN Document Server

    Frescura, F A M; Frank, B S

    2007-01-01

    We discuss methods currently in use for determining the significance of peaks in the periodograms of time series. We discuss some general methods for constructing significance tests, false alarm probability functions, and the role played in these by independent random variables and by empirical and theoretical cumulative distribution functions. We also discuss the concept of "independent frequencies" in periodogram analysis. We propose a practical method for estimating the significance of periodogram peaks, applicable to all time series irrespective of the spacing of the data. This method, based on Monte Carlo simulations, produces significance tests that are tailor-made for any given astronomical time series.

  20. Integrated high-speed DFB light source and narrow-bandwidth RCE photodetector for WDM fiber communication network application

    Science.gov (United States)

    Wang, Qiming; Li, Cheng; Pan, Zhong; Luo, Yi

    2000-10-01

    Electroabsorption (EA) modulator integrated with partially gain coupling distributed feedback (DFB) lasers have been fabricated and shown high single mode yield and wavelength stability. The small signal bandwidth is about 7.5 GHz. Strained Si1-xGex/Si multiple quantum well (MQW) resonant-cavity enhanced (RCE) photodetectors with SiO2/Si distributed Bragg reflector (DBR) as the mirrors have been fabricated and shown a clear narrow bandwidth response. The external quantum efficiency at 1.3 micrometer is measured to be about 3.5% under reverse bias of 16 V. A novel GaInNAs/GaAs MQW RCE p-i-n photodetector with high reflectance GaAs/AlAs DBR mirrors has also been demonstrated and shown the selectively detecting function with the FWHM of peak response of 12 nm.

  1. A Narrow-Linewidth Atomic Line Filter for Free Space Quantum Key Distribution under Daytime Atmospheric Conditions

    Science.gov (United States)

    Brown, Justin; Woolf, David; Hensley, Joel

    2016-05-01

    Quantum key distribution can provide secure optical data links using the established BB84 protocol, though solar backgrounds severely limit the performance through free space. Several approaches to reduce the solar background include time-gating the photon signal, limiting the field of view through geometrical design of the optical system, and spectral rejection using interference filters. Despite optimization of these parameters, the solar background continues to dominate under daytime atmospheric conditions. We demonstrate an improved spectral filter by replacing the interference filter (Δν ~ 50 GHz) with an atomic line filter (Δν ~ 1 GHz) based on optical rotation of linearly polarized light through a warm Rb vapor. By controlling the magnetic field and the optical depth of the vapor, a spectrally narrow region can be transmitted between crossed polarizers. We find that the transmission is more complex than a single peak and evaluate peak transmission as well as a ratio of peak transmission to average transmission of the local spectrum. We compare filters containing a natural abundance of Rb with those containing isotopically pure 87 Rb and 85 Rb. A filter providing > 95 % transmission and Δν ~ 1.1 GHz is achieved.

  2. Hubbert's Peak -- A Physicist's View

    Science.gov (United States)

    McDonald, Richard

    2011-04-01

    Oil, as used in agriculture and transportation, is the lifeblood of modern society. It is finite in quantity and will someday be exhausted. In 1956, Hubbert proposed a theory of resource production and applied it successfully to predict peak U.S. oil production in 1970. Bartlett extended this work in publications and lectures on the finite nature of oil and its production peak and depletion. Both Hubbert and Bartlett place peak world oil production at a similar time, essentially now. Central to these analyses are estimates of total ``oil in place'' obtained from engineering studies of oil reservoirs as this quantity determines the area under the Hubbert's Peak. Knowing the production history and the total oil in place allows us to make estimates of reserves, and therefore future oil availability. We will then examine reserves data for various countries, in particular OPEC countries, and see if these data tell us anything about the future availability of oil. Finally, we will comment on synthetic oil and the possibility of carbon-neutral synthetic oil for a sustainable future.

  3. A Narrow View of Reading Promotes Comprehension

    National Research Council Canada - National Science Library

    Alan G Kamhi

    2007-01-01

      In sum, embracing the narrow view of reading will promote differentiated assessment of reading and content-specific knowledge that will not only eliminate the reading crisis, but also focus attention...

  4. Device Physics of Narrow Gap Semiconductors

    CERN Document Server

    Chu, Junhao

    2010-01-01

    Narrow gap semiconductors obey the general rules of semiconductor science, but often exhibit extreme features of these rules because of the same properties that produce their narrow gaps. Consequently these materials provide sensitive tests of theory, and the opportunity for the design of innovative devices. Narrow gap semiconductors are the most important materials for the preparation of advanced modern infrared systems. Device Physics of Narrow Gap Semiconductors offers descriptions of the materials science and device physics of these unique materials. Topics covered include impurities and defects, recombination mechanisms, surface and interface properties, and the properties of low dimensional systems for infrared applications. This book will help readers to understand not only the semiconductor physics and materials science, but also how they relate to advanced opto-electronic devices. The last chapter applies the understanding of device physics to photoconductive detectors, photovoltaic infrared detector...

  5. Narrow deeply bound K- atomic states

    Science.gov (United States)

    Friedman, E.; Gal, A.

    1999-07-01

    Using optical potentials fitted to a comprehensive set of strong interaction level shifts and widths in K- atoms, we predict that the K- atomic levels which are inaccessible in the atomic cascade process are generally narrow, spanning a range of widths about 50-1500 keV over the entire periodic table. The mechanism for this narrowing is different from the mechanism for narrowing of pionic atom levels. Examples of such `deeply bound' K- atomic states are given, showing that in many cases these states should be reasonably well resolved. Several reactions which could be used to form these `deeply bound' states are mentioned. Narrow deeply bound states are expected also in overlinep atoms.

  6. Discriminate Modelling of Peak and Off-Peak Motorway Capacity

    Directory of Open Access Journals (Sweden)

    Hashim Mohammed Alhassan

    2013-02-01

    Full Text Available Traffic theory is concerned with the movement of discrete objects in real time over a finite network in 2 Dimensions. It is compatible with or dependent on fundamental diagram of traffic. Without question traffic flow is an essential quantitative parameter that is used in planning, designs and roadway improvements.  Road capacity is significant because it is an important indicator of road performance and can point road managers in the right road maintenance and traffic management direction. In this paper four direct empirical capacity measurement methods have been considered. To test the efficacy of each method, data for peak period, off-peak and transition to peak have been used. The headway and the volume methods lack predictive capability and are suitable only for current assessment of flow rates.  The product limit method is weak in its predictive capability in view of the arbitrariness in the selection of the capacity value. It is also an extreme value method; hence not all volume data can be used with this method. The fundamental diagram method has good predictive capability and furnishes capacity values consistent with the standard of the facility. Unlike other methods, it does not rely on bottleneck conditions to deliver the capacity value.  The paper concluded that each method is uniquely suited to prevailing conditions and can be so employed.

  7. Longitudinal peak detected Schottky spectrum

    CERN Document Server

    Shaposhnikova, E

    2009-01-01

    The "peak detected Schottky" spectrum is a diagnostic used since the late seventies for beam observation in the SPS and now already applied to the LHC. This tool was always believed, however without proof, to give a good picture of the particle distribution in synchrotron frequencies similar to the longitudinal Schottky spectrum of unbunched beam for revolution frequencies.In this paper an analysis of this measurement technique is presented both in a general form and for the particular realisation in the SPS. In addition the limitations of the present experimental set-up are discussed together with possible improvements. The analysis shows that for an optimised experimental set-up the spectrum of the peak detected signal is very close to the synchrotron frequency distribution inside the bunch - much closer than that given by the traditional longitudinal bunched-beam Schottky spectrum.

  8. Narrow line diode laser stacks for DPAL pumping

    Science.gov (United States)

    Koenning, Tobias; Irwin, David; Stapleton, Dean; Pandey, Rajiv; Guiney, Tina; Patterson, Steve

    2014-02-01

    Diode pumped alkali metal vapor lasers (DPALs) offer the promise of scalability to very high average power levels while maintaining excellent beam quality, making them an attractive candidate for future defense applications. A variety of gain media are used and each requires a different pump wavelength: near 852nm for cesium, 780nm for rubidium, 766nm for potassium, and 670nm for lithium atoms. The biggest challenge in pumping these materials efficiently is the narrow gain media absorption band of approximately 0.01nm. Typical high power diode lasers achieve spectral widths around 3nm (FWHM) in the near infrared spectrum. With state of the art locking techniques, either internal to the cavity or externally mounted gratings, the spectral width can typically be reduced to 0.5nm to 1nm for kW-class, high power stacks. More narrow spectral width has been achieved at lower power levels. The diode's inherent wavelength drift over operating temperature and output power is largely, but not completely, eliminated. However, standard locking techniques cannot achieve the required accuracy on the location of the spectral output or the spectral width for efficient DPAL pumping. Actively cooled diode laser stacks with continuous wave output power of up to 100W per 10mm bar at 780nm optimized for rubidium pumping will be presented. Custom designed external volume holographic gratings (VHGs) in conjunction with optimized chip material are used to narrow and stabilize the optical spectrum. Temperature tuning on a per-bar-level is used to overlap up to fifteen individual bar spectra into one narrow peak. At the same time, this tuning capability can be used to adjust the pump wavelength to match the absorption band of the active medium. A spectral width of <0.1nm for the entire stack is achieved at <1kW optical output power. Tuning of the peak wavelength is demonstrated for up to 0.15nm. The technology can easily be adapted to other diode laser wavelengths to pump different materials.

  9. Drivers of peak sales for pharmaceutical brands

    NARCIS (Netherlands)

    Fischer, Marc; Leeflang, Peter S. H.; Verhoef, Peter C.

    2010-01-01

    Peak sales are an important metric in the pharmaceutical industry. Specifically, managers are focused on the height-of-peak-sales and the time required achieving peak sales. We analyze how order of entry and quality affect the level of peak sales and the time-to-peak-sales of pharmaceutical brands.

  10. Nonlinear generalization of Den Hartog's equal-peak method

    Science.gov (United States)

    Habib, G.; Detroux, T.; Viguié, R.; Kerschen, G.

    2015-02-01

    This study addresses the mitigation of a nonlinear resonance of a mechanical system. In view of the narrow bandwidth of the classical linear tuned vibration absorber, a nonlinear absorber, termed the nonlinear tuned vibration absorber (NLTVA), is introduced in this paper. An unconventional aspect of the NLTVA is that the mathematical form of its restoring force is tailored according to the nonlinear restoring force of the primary system. The NLTVA parameters are then determined using a nonlinear generalization of Den Hartog's equal-peak method. The mitigation of the resonant vibrations of a Duffing oscillator is considered to illustrate the proposed developments.

  11. Photonic bandgap narrowing in conical hollow core Bragg fibers

    Energy Technology Data Exchange (ETDEWEB)

    Ozturk, Fahri Emre; Yildirim, Adem; Kanik, Mehmet [UNAM-National Nanotechnology Research Center, Bilkent University, 06800 Ankara (Turkey); Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara (Turkey); Bayindir, Mehmet, E-mail: bayindir@nano.org.tr [UNAM-National Nanotechnology Research Center, Bilkent University, 06800 Ankara (Turkey); Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara (Turkey); Department of Physics, Bilkent University, 06800 Ankara (Turkey)

    2014-08-18

    We report the photonic bandgap engineering of Bragg fibers by controlling the thickness profile of the fiber during the thermal drawing. Conical hollow core Bragg fibers were produced by thermal drawing under a rapidly alternating load, which was applied by introducing steep changes to the fiber drawing speed. In conventional cylindrical Bragg fibers, light is guided by omnidirectional reflections from interior dielectric mirrors with a single quarter wave stack period. In conical fibers, the diameter reduction introduced a gradient of the quarter wave stack period along the length of the fiber. Therefore, the light guided within the fiber encountered slightly smaller dielectric layer thicknesses at each reflection, resulting in a progressive blueshift of the reflectance spectrum. As the reflectance spectrum shifts, longer wavelengths of the initial bandgap cease to be omnidirectionally reflected and exit through the cladding, which narrows the photonic bandgap. A narrow transmission bandwidth is particularly desirable in hollow waveguide mid-infrared sensing schemes, where broadband light is coupled to the fiber and the analyte vapor is introduced into the hollow core to measure infrared absorption. We carried out sensing simulations using the absorption spectrum of isopropyl alcohol vapor to demonstrate the importance of narrow bandgap fibers in chemical sensing applications.

  12. Microlayer during boiling in narrow slot channels

    Science.gov (United States)

    Diev, Mikhail D.; Leontiev, Alexander I.

    1997-01-01

    An international space station Alpha will have a two-phase thermal control system. Boiling of a liquid ammonia will be a process of heat collection in evaporative heat exchangers. Unfortunately, only little data is available for boiling heat transfer in microgravity. Geometries of boiling channels working good in normal gravity are not appropriate in microgravity, and special means should be worked out to avoid some undesired events. From this point of view, the narrow slot channels may be assumed as a promising geometry for microgravity operation. During boiling in narrow slots, the vapor bubbles are flattened between the channel walls. The vapor phase and the channel wall are separated by a thin liquid film which is known as a microlayer. The paper presents the experimental results compared to the theoretical analysis, the paper also shows the narrow slot channels as a perspective configuration for microgravity applications.

  13. Narrow linewidth Brillouin laser based on chalcogenide photonic chip

    CERN Document Server

    Kabakova, Irina V; Choi, Duk-Yong; Debbarma, Sukhanta; Luther-Davies, Barry; Madden, Stephen J; Eggleton, Benjamin J

    2013-01-01

    We present the first demonstration of a narrow linewidth, waveguide-based Brillouin laser which is enabled by large Brillouin gain of a chalcogenide chip. The waveguides are equipped with vertical tapers for low loss coupling. Due to optical feedback for the Stokes wave, the lasing threshold is reduced to 360 mW, which is 5 times lower than the calculated single-pass Brillouin threshold for the same waveguide. The slope efficiency of the laser is found to be 30% and the linewidth of 100 kHz is measured using a self-heterodyne method.

  14. Is there an ADAF in Radio Galaxies with Double-Peaked Balmer Lines?

    Science.gov (United States)

    Nagao, T.; Murayama, T.; Shioya, Y.; Taniguchi, Y.

    In order to examine the prediction that the broad-line radio galaxies (BLRGs) with double-peaked Balmer lines harbor an accretion disk characterized by an advection-dominated accretion flow (ADAF) in their nuclei, we investigate narrow emission line flux ratios of the narrow-line regions which are photoionized by nuclear continuum radiation. By carrying out intensive photoionization model calculations, we find that the data of the BLRGs with the double-peaked Balmer lines are consistent with the models adopting the SED without a strong big blue bump, while the data of the BLRGs without the double-peaked emission lines are well described by the models adopting the SED with a strong big blue bump. This result supports the idea that the double-peaked Balmer lines arise at an outer region of an accretion disk which is illuminated by an inner, geometrically thick ADAF.

  15. Efficient, Narrow-Pass-Band Optical Filters

    Science.gov (United States)

    Sandford, Stephen P.

    1996-01-01

    Optical filters with both narrow pass bands and high efficiencies fabricated to design specifications. Offer tremendous improvements in performance for number of optical (including infrared) systems. In fiber-optic and free-space communication systems, precise frequency discrimination afforded by narrow pass bands of filters provide higher channel capacities. In active and passive remote sensors like lidar and gas-filter-correlation radiometers, increased efficiencies afforded by filters enhance detection of small signals against large background noise. In addition, sizes, weights, and power requirements of many optical and infrared systems reduced by taking advantage of gains in signal-to-noise ratios delivered by filters.

  16. On Narrow Nucleon Excitation N*(1685)

    CERN Document Server

    Kuznetsov, V; Thuermann, M

    2011-01-01

    We collected notes and simple estimates about putative narrow nucleon N*(1685) - the candidate for the non-strange member of the exotic anti-decuplet of baryons. In particular, we consider the recent high precision data on eta photoproduction off free proton obtained by the Crystal Ball Collaboration at MAMI. We show that it is difficult to describe peculiarities of these new data in the invariant energy interval of W ~ 1650-1750 MeV in terms of known wide resonances. Using very simple estimates, we show that the data may indicate an existence of a narrow N*(1685) with small photocoupling to the proton.

  17. Large static tuning of narrow-beam terahertz plasmonic lasers operating at 78K

    Science.gov (United States)

    Wu, Chongzhao; Jin, Yuan; Reno, John L.; Kumar, Sushil

    2017-02-01

    A new tuning mechanism is demonstrated for single-mode metal-clad plasmonic lasers, in which the refractive-index of the laser's surrounding medium affects the resonant-cavity mode in the same vein as the refractive-index of gain medium inside the cavity. Reversible, continuous, and mode-hop-free tuning of ˜57 GHz is realized for single-mode narrow-beam terahertz plasmonic quantum-cascade lasers (QCLs), which is demonstrated at a much more practical temperature of 78 K . The tuning is based on post-process deposition/etching of a dielectric (silicon-dioxide) on a QCL chip that has already been soldered and wire-bonded onto a copper mount. This is a considerably larger tuning range compared to previously reported results for terahertz QCLs with directional far-field radiation patterns. The key enabling mechanism for tuning is a recently developed antenna-feedback scheme for plasmonic lasers, which leads to the generation of hybrid surface-plasmon-polaritons propagating outside the cavity of the laser with a large spatial extent. The effect of dielectric deposition on QCL's characteristics is investigated in detail including that on maximum operating temperature, peak output power, and far-field radiation patterns. Single-lobed beam with low divergence (<7° ) is maintained through the tuning range. The antenna-feedback scheme is ideally suited for modulation of plasmonic lasers and their sensing applications due to the sensitive dependence of spectral and radiative properties of the laser on its surrounding medium.

  18. Narrow-Band Applications of Communications Satellites.

    Science.gov (United States)

    Cowlan, Bert; Horowitz, Andrew

    This paper attempts to describe the advantages of "narrow-band" applications of communications satellites for education. It begins by discussing the general controversy surrounding the use of satellites in education, by placing the concern within the larger context of the general debate over the uses of new technologies in education, and by…

  19. Narrow vision after view-broadening travel.

    Science.gov (United States)

    Melo, Mariana de Mendonça; Ciriano, Jose P Martinez; van Genderen, Perry J J

    2008-01-01

    Loss of vision is a threatening presentation of disease. We describe a case of acute idiopathic blind spot enlargement in a 26-year-old male traveler who presented with narrow vision after a journey to Indonesia. Although the patient used mefloquine at time of presentation, we were unable to retrieve sound data incriminating mefloquine in this rare eye disorder.

  20. Application of direct peak analysis to energy dispersive x-ray fluorescence spectra

    Energy Technology Data Exchange (ETDEWEB)

    Nielson, K.K.

    1977-07-01

    A modified Covell method for direct peak analysis has been applied to energy dispersive x-ray fluorescence spectra. The method is background independent and is well-suited to computerized data reduction. It provides acceptable precision, minimizes errors from instrumental gain shift, and permits peak overlap correction. Peak overlap errors exhibit both positive and negative nodes as a function of peak separation distance, and are corrected using concentration ratios determined from thin, single-element standards. Peak precisions and overlaps are evaluated as a function of window width to aid in width selection. Least-square polynomial smoothing prior to peak analysis significantly improves peak area precisions without significantly affecting their accuracies.

  1. Identification of photoelectron energy peaks in Saturn's inner neutral torus

    Science.gov (United States)

    Schippers, P.; André, N.; Johnson, R. E.; Blanc, M.; Dandouras, I.; Coates, A. J.; Krimigis, S. M.; Young, D. T.

    2009-12-01

    We present observations from the Cassini Plasma Electron Spectrometer (CAPS/ELS) of characteristic peaks in the electron energy spectrum that are identified in the innermost regions of the Saturnian magnetosphere during low-latitude orbits of the Cassini spacecraft around Saturn. We show how a narrow electron energy peak at about 20 eV and a possible peak at about 42 eV can be extracted from the background in CAPS observations after the contamination from high-energy particles has been removed from the measurements. We estimate the density of the newly discovered electron population to be a small fraction (10%) of the electron density measured in the CAPS/ELS energy range, and a much smaller fraction (about 1%) of the total electron density measured by Radio and Plasma Wave Science since our measurements are affected by spacecraft negative potential. We suggest that this population corresponds to photoelectrons generated by the solar EUV photoionization of the extended cloud of neutral gas observed in these regions. We use pitch angle information to assess the near-equatorial source of these photoelectrons and a simple model of chemistry in order to further support our interpretation. Therefore, photoionization seems to be an additional process for plasma production in the innermost Saturnian magnetosphere. Finally, we mention that the comparison of the modeled and the observed photoelectron peak energies could be used to estimate the spacecraft potential in this region which is measured independently by the Langmuir Probe.

  2. Assessing peak aerobic capacity in Dutch law enforcement officers

    Directory of Open Access Journals (Sweden)

    Harriet Wittink

    2015-06-01

    Full Text Available Objectives: To cross-validate the existing peak rate of oxygen consumption (VO2peak prediction equations in Dutch law enforcement officers and to determine whether these prediction equations can be used to predict VO2peak for groups and in a single individual. A further objective was to report normative absolute and relative VO2peak values of a sample of law enforcement officers in the Netherlands. Material and Methods: The peak rate of oxygen consumption (ml×kg–1×min–1 was measured using a maximal incremental bicycle test in 1530 subjects, including 1068 male and 461 female police officers. Validity of the prediction equations for groups was assessed by comparing predicted VO2peak with measured VO2peak using paired t-tests. For individual differences limits of agreement (LoA were calculated. Equations were considered valid for individuals when the difference between measured and predicted VO2peak did not exceed ±1 metabolic equivalent (MET in 95% of individuals. Results: None of the equations met the validity criterion of 95% of individuals having ±1 MET difference or less than the measured value. Limits of agreement (LoAs were large in all predictions. At the individual level, none of the equations were valid predictors of VO2peak (ml×kg–1×min–1. Normative values for Dutch law enforcement officers were presented. Conclusions: Substantial differences between measured and predicted VO2peak (ml×kg–1×min–1 were found. Most tested equations were invalid predictors of VO2peak at group level and all were invalid at individual levels.

  3. Assessing peak aerobic capacity in Dutch law enforcement officers.

    Science.gov (United States)

    Wittink, Harriet; Takken, Tim; de Groot, Janke; Reneman, Michiel; Peters, Roelof; Vanhees, Luc

    2015-01-01

    To cross-validate the existing peak rate of oxygen consumption (VO2peak) prediction equations in Dutch law enforcement officers and to determine whether these prediction equations can be used to predict VO2peak for groups and in a single individual. A further objective was to report normative absolute and relative VO2peak values of a sample of law enforcement officers in the Netherlands. The peak rate of oxygen consumption (ml×kg-1×min-1) was measured using a maximal incremental bicycle test in 1530 subjects, including 1068 male and 461 female police officers. Validity of the prediction equations for groups was assessed by comparing predicted VO2peak with measured VO2peak using paired t-tests. For individual differences limits of agreement (LoA) were calculated. Equations were considered valid for individuals when the difference between measured and predicted VO2peak did not exceed ±1 metabolic equivalent (MET) in 95% of individuals. None of the equations met the validity criterion of 95% of individuals having ±1 MET difference or less than the measured value. Limits of agreement (LoAs) were large in all predictions. At the individual level, none of the equations were valid predictors of VO2peak (ml×kg-1×min-1). Normative values for Dutch law enforcement officers were presented. Substantial differences between measured and predicted VO2peak (ml×kg-1×min-1) were found. Most tested equations were invalid predictors of VO2peak at group level and all were invalid at individual levels. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  4. Neurofeedback training for peak performance

    Directory of Open Access Journals (Sweden)

    Marek Graczyk

    2014-11-01

    Full Text Available [b]aim[/b]. One of the applications of the Neurofeedback methodology is peak performance in sport. The protocols of the neurofeedback are usually based on an assessment of the spectral parameters of spontaneous EEG in resting state conditions. The aim of the paper was to study whether the intensive neurofeedback training of a well-functioning Olympic athlete who has lost his performance confidence after injury in sport, could change the brain functioning reflected in changes in spontaneous EEG and event related potentials (ERPs. [b]case study[/b]. The case is presented of an Olympic athlete who has lost his performance confidence after injury in sport. He wanted to resume his activities by means of neurofeedback training. His QEEG/ERP parameters were assessed before and after 4 intensive sessions of neurotherapy. Dramatic and statistically significant changes that could not be explained by error measurement were observed in the patient. [b]conclusion[/b]. Neurofeedback training in the subject under study increased the amplitude of the monitoring component of ERPs generated in the anterior cingulate cortex, accompanied by an increase in beta activity over the medial prefrontal cortex. Taking these changes together, it can be concluded that that even a few sessions of neurofeedback in a high performance brain can significantly activate the prefrontal cortical areas associated with increasing confidence in sport performance.

  5. Peak Detection Using Wavelet Transform

    Directory of Open Access Journals (Sweden)

    Omar Daoud

    2014-07-01

    Full Text Available A new work based-wavelet transform is designed to o vercome one of the main drawbacks that found in the present new technologies. Orthogonal Frequency Divi sion Multiplexing (OFDMis proposed in the literature to enhance the multimedia resolution. Ho wever, the high peak power (PAPR values will obstr uct such achievements. Therefore, a new proposition is found in this work, making use of the wavelet transforms methods, and it is divided into three ma in stages; de-noising stage, thresholding stage and then the replacement stage. In order to check the system stages validity; a mat hematical model has been built and its checked afte r using a MATLAB simulation. A simulated bit error ra te (BER achievement will be compared with our previously published work, where an enhancement fro m 8×10 -1 to be 5×10 -1 is achieved. Moreover, these results will be compared to the work found in the l iterature, where we have accomplished around 27% PAPR extra reduction. As a result, the BER performance has been improved for the same bandwidth occupancy. Moreover and due to the de-noise stage, the verification rate ha s been improved to reach 81%. This is in addition t o the noise immunity enhancement.

  6. Sensor based on Fano resonances of plane metamaterial with narrow slits

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Wan-Xia, E-mail: kate@mail.ahnu.edu.cn [State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education) and Physics Department, Fudan University, Shanghai 200433 (China); The College of Physics and Electronic Information, Anhui Normal University, Wuhu, Anhui 241000 (China); Guo, Juan-Juan; Wang, Mao-Sheng; Zhao, Guo-Ren [The College of Physics and Electronic Information, Anhui Normal University, Wuhu, Anhui 241000 (China)

    2017-03-11

    The optical properties of a composite metamaterial composed of narrow slits and nano hole pairs have been investigated experimentally and numerically. The strength of the transmission peak originating from the interference between the coupled surface plasmon polaritons (SPP) of the narrow slit and the SPP modes of the hole array is modulated by the degree of symmetry breaking. Some SPP modes can be inhibited by controlling the spacer layer thickness. Our metamaterial has potential applications in sensing and weak signal detection. - Highlights: • The plasmonic nanostructure composed of narrow slits and nano hole pairs were designed. • The optical properties were investigated experimentally and numerically. • The Fano resonances were found on the compound nanostructure. • The results have potential applications in sensing and weak signal detection.

  7. Tunable plasmonic filter with circular metal–insulator– metal ring resonator containing double narrow gaps

    Indian Academy of Sciences (India)

    ZHENG GAIGE; XU LINHUA; LIU YUZHU

    2016-05-01

    Tunable filter based on two metal–insulator–metal (MIM) waveguides coupled to each other by a ring resonator with double narrow gaps is designed and numerically investigated by finitedifference time-domain (FDTD) simulations. The propagating modes of surface plasmon polaritons (SPPs) are studied. By introducing narrow gaps in ring resonators, the transmission in differentresonance modes can be effectively adjusted by changing the gap width (g), and the transmitted peak wavelength has a nonlinear relationship with g. Another structure consisting two cascading ring resonators and regular MIM waveguide have also been proposed. The mechanism based on circular ring resonators with narrow gaps may provide a novel method for designing all-opticalintegrated components in optical communication and computing.

  8. Narrow optical filtering with plasmonic nanoshells

    CERN Document Server

    Martynov, Y B; Tanachev, I A; Gladyshev, P P

    2011-01-01

    Narrow optical band pass filters are widely used in systems with optical processing of information, color displays development and optical computers. We show that such ultra filters can be created by means of nanoparticles which consist of a dielectric sphere and a metallic shell. The components can be adjusted such that there is a remarkable transparency at the desired wavelength range, while a strong absorption takes place outside of this region.

  9. Code optimizations for narrow bitwidth architectures

    OpenAIRE

    Bhagat, Indu

    2012-01-01

    This thesis takes a HW/SW collaborative approach to tackle the problem of computational inefficiency in a holistic manner. The hardware is redesigned by restraining the datapath to merely 16-bit datawidth (integer datapath only) to provide an extremely simple, low-cost, low-complexity execution core which is best at executing the most common case efficiently. This redesign, referred to as the Narrow Bitwidth Architecture, is unique in that although the datapath is squeezed to 16-bits...

  10. Band Gap Narrowing in Heavily Doped Silicon.

    Science.gov (United States)

    Gupta, Tapan Kumar

    Two analytic models for transport and band gap narrowing in heavily doped (N_{rm D} > 10^{20} cm^ {-3}) silicon have been set up and verified through measurements on n^{+} -p junction devices. The first model is based on calculation of the ratio of the charge present in the emitter of the n^{+} region of the junction to that of the charge present in the absence of band gap shrinkage. Fermi-Dirac statistics are employed and are found to have a significant effect at this doping level. The second model is based on current transport of minority carriers in the n^{+} region. In this model only two parameters need to be known, the diffusion coefficient and the diffusion length for minority carriers, to calculate the band gap narrowing. An empirical relation between band gap narrowing and donor concentration has also been established based on experimental values of diffusion coefficient and mobility. These models have been verified by several different experimental techniques including surface photovoltage, open circuit voltage decay, photoconductivity decay and modulation reflection spectroscopy. The results indicate that, in the impurity range above about 10^{20} cm^{-3}, Fermi-Dirac statistics must be invoked in order to achieve a satisfactory fit with experimental data.

  11. Effects of equipment and technique on peak flow measurements

    Directory of Open Access Journals (Sweden)

    O'Driscoll B Ronan

    2006-06-01

    Full Text Available Abstract Background Different lung function equipment and different respiratory manoeuvres may produce different Peak Expiratory Flow (PEF results. Although the PEF is the most common lung function test, there have been few studies of these effects and no previous study has evaluated both factors in a single group of patients. Methods We studied 36 subjects (PEF range 80–570 l/min. All patients recorded PEF measurements using a short rapid expiration following maximal inspiration (PEF technique or a forced maximal expiration to residual volume (FVC technique. Measurements were made using a Wright's peak flow meter, a turbine spirometer and a Fleisch pneumotachograph spirometer. Results The mean PEF was 8.7% higher when the PEF technique was used (compared with FVC technique, p Conclusion Peak flow measurements are affected by the instruction given and by the device and Peak Flow scale used. Patient management decisions should not be based on PEF measurement made on different instruments.

  12. Packaged, High-Power, Narrow-Linewidth Slab-Coupled Optical Waveguide External Cavity Laser (SCOWECL)

    Science.gov (United States)

    2010-12-01

    efficiency. With the 20% reflecli vity FBG, the laser ex hibi ts a threshold of 0.9 A and reaches a CW peak power of 0.37 W aI 4 A. The peak effic ...twice the photon energy . The SCOWECL is expected to find applications in free space coherent optical communications and in microwave photollic...Dai , " High effic ient and narrow linewidlh fiber laser based on fiber grat ing Fabry- Perot cavity," Frolltiers of Oploeieclrollics il/ Chinll, vol

  13. Search for narrow. mu. (. pi. ( mass enhancements in a neutrino bubble-chamber experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ballagh, H.C.; Bingham, H.H.; Lawry, T.J.; Lynch, G.R.; Lys, J.; Stevenson, M.L.; Huson, F.R.; Schmidt, E.; Smart, W.; Sokoloff, M.D.

    1984-04-01

    In a Fermilab 15-foot bubble-chamber experiment, ..mu../sup - +/..pi../sup + -/ mass spectra were studied in 8444 neutrino interactions and 1367 antineutrino interactions. No significant narrow mass enhancements were found. A peak near 430 MeV/c/sup 2/ was observed, but when resolution is taken into account its significance is only roughly-equal1sigma and its angular distributions do not show the characteristics expected for a resonance.

  14. The bias of weighted dark matter halos from peak theory

    CERN Document Server

    Verde, Licia; Simpson, Fergus; Alvarez-Gaume, Luis; Heavens, Alan; Matarrese, Sabino

    2014-01-01

    We give an analytical form for the weighted correlation function of peaks in a Gaussian random field. In a cosmological context, this approach strictly describes the formation bias and is the main result here. Nevertheless, we show its validity and applicability to the evolved cosmological density field and halo field, using Gaussian random field realisations and dark matter N-body numerical simulations. Using this result from peak theory we compute the bias of peaks (and dark matter halos) and show that it reproduces results from the simulations at the ${\\mathcal O}(10\\%)$ level. Our analytical formula for the bias predicts a scale-dependent bias with two characteristics: a broad band shape which, however, is most affected by the choice of weighting scheme and evolution bias, and a more robust, narrow feature localised at the BAO scale, an effect that is confirmed in simulations. This scale-dependent bias smooths the BAO feature but, conveniently, does not move it. We provide a simple analytic formula to des...

  15. 27 CFR 9.140 - Atlas Peak.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Atlas Peak. 9.140 Section... THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.140 Atlas Peak. (a) Name. The name of the viticultural area described in this section is “Atlas Peak.”...

  16. Thermally assisted photo transfer OSL from deep traps in Al2O3:C grains exhibiting different TL peak shapes.

    Science.gov (United States)

    Polymeris, George S; Kitis, George

    2012-10-01

    The present work studies the thermally assisted photo transfer OSL (TAPT OSL) signal in the case of Al(2)O(3):C samples showing double-structured main dosimetric TL peaks. The measurement signal provides indirect experimental evidence regarding the presence of deep traps along with one transfer mechanism extremely powerful and efficient. The experimental features of this signal are presented along with those yielded for samples with narrow TL peaks for the sake of comparison. In the framework of a dosimetric characterization, the straightforward relation observed between the TAPT OSL integrated intensity and the dose, even if non-linear, implies that this signal could be effectively used towards dosimetry purposes in the high dose region up to 250 Gy. Furthermore, the study on the influence of the annealing temperature on the TL glow curve shape on Al(2)O(3):C grains is attempted. The variety of glow curve shapes reported especially in the case of single grains is not affected by high temperature annealing, since its effect is dominant even after heating at 1085°C. Thus, this variety should not be correlated to the different deep trap occupancies, but rather be attributed to a possible structural defect. The main dosimetric TL peak af all grains is considered to be a composite of two unambiguously different traps of non-first-order kinetics. The low temperature part of these traps, reaching a maximum at ~190°C is an electron trap and the high temperature part with maximum at ~250°C is a hole trap. TL dose response of Al(2)O(3):C grains presenting double peak structures is presented for the first time in literature, suggesting the usefulness on the applicability of Al(2)O(3):C in the dose regime up to 100 Gy. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Cervical spinal canal narrowing in idiopathic syringomyelia

    Energy Technology Data Exchange (ETDEWEB)

    Struck, Aaron F. [Massachusetts General Hospital, Department of Neurology, Boston, MA (United States); Carr, Carrie M. [Mayo Clinic, Department of Radiology, Rochester, MN (United States); Shah, Vinil [University of California San Francisco, Department of Radiology, San Francisco, CA (United States); Hesselink, John R. [University of California San Diego, Department of Radiology, San Diego, CA (United States); Haughton, Victor M. [University of Wisconsin, Department of Radiology, Madison, WI (United States)

    2016-08-15

    The cervical spine in Chiari I patient with syringomyelia has significantly different anteroposterior diameters than it does in Chiari I patients without syringomyelia. We tested the hypothesis that patients with idiopathic syringomyelia (IS) also have abnormal cervical spinal canal diameters. The finding in both groups may relate to the pathogenesis of syringomyelia. Local institutional review boards approved this retrospective study. Patients with IS were compared to age-matched controls with normal sagittal spine MR. All subjects had T1-weighted spin-echo (500/20) and T2-weighted fast spin-echo (2000/90) sagittal cervical spine images at 1.5 T. Readers blinded to demographic data and study hypothesis measured anteroposterior diameters at each cervical level. The spinal canal diameters were compared with a Mann-Whitney U test. The overall difference was assessed with a Friedman test. Seventeen subjects were read by two reviewers to assess inter-rater reliability. Fifty IS patients with 50 age-matched controls were studied. IS subjects had one or more syrinxes varying from 1 to 19 spinal segments. Spinal canal diameters narrowed from C1 to C3 and then enlarged from C5 to C7 in both groups. Diameters from C2 to C4 were narrower in the IS group (p < 0.005) than in controls. The ratio of the C3 to the C7 diameters was also smaller (p = 0.004) in IS than controls. Collectively, the spinal canal diameters in the IS were significantly different from controls (Friedman test p < 0.0001). Patients with IS have abnormally narrow upper and mid cervical spinal canal diameters and greater positive tapering between C3 and C7. (orig.)

  18. Global viscous overstabilities in narrow rings

    Science.gov (United States)

    Longaretti, Pierre-Yves; French, Richard G.; Nicholson, Philip D.

    2016-10-01

    Local viscous overstabilities have been the focus of a number of theoretical analyses in the last decades due to the rôle they are believed to play in the creation of the small scale structure of broad ring systems (Saturn, Uranus). Global viscous overstabilities have also been investigated in the 1980s and 1990s as a potential source of narrow ring eccentricities (Longaretti and Rappaport, 1995, Icarus, 116, 376).An important feature of global viscous overstabilities is that they produce slow relative librating or circulating motions of narrow ring edges; they may also produce slowly librating or circulating components of edge modes. This process is potentially relevant to explain the occurrence of unusually large apsidal shifts observed in some saturnian ringlets and may also explain the existence of the free m=2 B ring edge mode that is slowly circulating with respect to the component forced by Mimas.The time-scale of such motions is primarily controlled by the ring self-gravity and can be analytically quantified in a two-streamline analysis which yields a characteristic libration/circulation frequency Ωl = (n/π)(Mr/Mp)(a/δa)2H(q2) where n is the mean motion, Mr the ringlet or pertubed region mass, Mp the planet mass, a the semi-major axis, δa the narrow ringlet or pertubed region width and H(q2) a dimensionless factor of order unity that depends on the streamline compression parameter q. The related time-scale is of the order of a few years to a few tens of years depending on the surface density and ringlet/perturbed region geometry. Preliminary data analyzes indicate that the Maxwell and Huyghens ringlets are probably librating with periods consistent with this two-streamline estimate.The talk will briefly present the physics of global viscous overstabilities as well as more detailed applications to narrow rings, and if time permits, to edge modes.

  19. A method of searching for peaks and multiplets in {gamma}-ray spectra

    Energy Technology Data Exchange (ETDEWEB)

    Loska, L.; Janczyszyn, J. [Akademia Gorniczo-Hutnicza, Cracow (Poland). Inst. Wiertniczo-Naftowy

    1997-01-01

    A new method of searching peaks in gamma spectra is proposed. The method makes use of the well known Sterlinski`s algorithm. The number proportional to peak area and the variance of this number (from the Sterlinski`s method) are used in the criterion selecting ``true`` peaks. A comparison of performance in searching single and multiple peaks of the proposed method and others frequently used in practice shows a better quality of our method. (Author).

  20. Narrow Bandwidth Faraday Anomalous Dispersion Optical Filter%窄带 Faraday 反常色散光学滤波器

    Institute of Scientific and Technical Information of China (English)

    刘阳; 王健; 王海华; 康智慧; 王磊; 罗梦希; 闫西章; 王潇潇; 高锦岳

    2014-01-01

    研究 Faraday 反常色散光学滤波器,给出其理论计算过程和模拟结果。结果表明, Faraday反常色散光学滤波器有线翼和线芯透过两种工作方式,其中线翼透过单峰谱线线宽约为600 MHz,透过率约为25%,线芯透过谱线线宽约为700 MHz,透过率约为100%。实验结果与理论结果相符。%To obtain the weak signal light from the high background light,a narrow bandwidth Faraday anomalous dispersion optical filter (FADOF)was studied.The theoretical model for the filter was reported.The Faraday anomalous dispersion optical filters have two working modes:two side peak transmission and center peak transmission.The former work mode can get single peak transmission of 25% with a bandwidth of about 600 MHz.The other work mode can get a spectra with a transmission rate of almost 100% and a bandwith of about 700 MHz.The experimental measurements are consistent with theoretical results.

  1. Long-pulse-width narrow-bandwidth solid state laser

    Science.gov (United States)

    Dane, C.B.; Hackel, L.A.

    1997-11-18

    A long pulse laser system emits 500-1000 ns quasi-rectangular pulses at 527 nm with near diffraction-limited divergence and near transform-limited bandwidth. The system consists of one or more flashlamp-pumped Nd:glass zig-zag amplifiers, a very low threshold stimulated-Brillouin-scattering (SBS) phase conjugator system, and a free-running single frequency Nd:YLF master oscillator. Completely passive polarization switching provides eight amplifier gain passes. Multiple frequency output can be generated by using SBS cells having different pressures of a gaseous SBS medium or different SBS materials. This long pulse, low divergence, narrow-bandwidth, multi-frequency output laser system is ideally suited for use as an illuminator for long range speckle imaging applications. Because of its high average power and high beam quality, this system has application in any process which would benefit from a long pulse format, including material processing and medical applications. 5 figs.

  2. Statistics of narrow-band partially polarized light

    Science.gov (United States)

    Charnotskii, Mikhail

    2017-09-01

    A complete single-point statistical description of a narrow-band partially polarized optical field is developed in terms of the 2D period-averaged probability density function (PA-PDF) of the electrical field vector. This statistic can be measured using the coherent (heterodyne) detection. PA-PDF carries more information about the partially polarized light than the traditional Stokes vector. For a simple Gaussian partially polarized field the PA-PDF depends on 13 real parameters in contrast to the four parameters of the Stokes vector or coherence tensor. We show on several examples that the polarization state of the wave, as described by PA-PDF can vary significantly even while Stokes vector remains fixed.

  3. The Narrow Ridge Balance Test : A measure for one-leg lateral balance control

    NARCIS (Netherlands)

    Curtze, C.; Postema, K.; Akkermans, H.W.; Otten, B.; Hof, A.L.

    2010-01-01

    The assessment of balance capacity for people with widely different balance abilities is an important issue in clinical practice. We propose the narrow ridge balance test as a sensitive tool to assess one-leg balance capacity. In this test, participants are asked to perform single-leg stance on ridg

  4. A methodology to enlarge narrow stability windows

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Ewerton M.P.; Pastor, Jorge A.S.C.; Fontoura, Sergio A.B. [Pontificia Univ. Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil). Dept. de Engenharia Civil. Grupo de Tecnologia e Engenharia de Petroleo

    2004-07-01

    The stability window in a wellbore design is defined by the difference between fracture pressure and collapse pressure. Deep water environments typically present narrow stability windows, because rocks have low strength due to under-compaction process. Often also, horizontal wells are drilled to obtain a better development of reservoirs placed in thin layers of sandstone. In this scenario, several challenges are faced when drilling in deep water. The traditional approach for predicting instabilities is to determine collapses and fractures at borehole wall. However, the initiation of rupture does not indicate that the borehole fails to perform its function as a wellbore. Thus, a methodology in which the stability window may be enlarged is desirable. This paper presents one practical analytical methodology that consists in allowing wellbore pressures smaller than the conventional collapse pressure, i.e., based upon failure on the borehole wall. This means that a collapse region (shear failure) will be developed around the borehole wall. This collapse region is pre-defined and to estimate its size is used a failure criterion. The aforementioned methodology is implemented in a user-friendly software, which can perform analyses of stress, pore pressure, formation failure, mud weight and mud salinity design for drilling in shale formations. Simulations of a wellbore drilling in a narrow stability window environment are performed to demonstrate the improvements of using the methodology. (author)

  5. Cluster headache or narrow angle glaucoma?

    Directory of Open Access Journals (Sweden)

    Prasad Palimar

    1991-01-01

    Full Text Available A 47 year old man with episodes of attacks of pain, redness and mild blurring of vision was investigated for narrow angle glaucoma in view of shallow anterior chambers and a cupped optic disc. The history was reviewed following a spontaneous attack in hospital, which had features other than acute glaucoma. A diagnosis of cluster headache was made on the basis of tests. Cluster headache has been defined as unilateral intense pain, involving the eye and head on one side, usually associated with flushing, nasal congestion and lacrimation; the attacks recurring one or more times daily and lasting 20 - 120 minutes. Such attacks commonly continue for weeks or months and are separated by an asymptomatic period of months to years. This episodic nature, together with unilaterality and tendency to occur at night, closely mimics narrow angle glaucoma. Further, if patients have shallow anterior chambers and disc cupping, the differentiation becomes more difficult yet critical. Resource to provocative tests is often the only answer as the following case report demonstrates.

  6. The Narrow Line Region of Ark 564

    CERN Document Server

    Contini, M; Viegas, S M M; Contini, Marcella; Rodriguez-Ardila, Alberto; Viegas, Sueli

    2003-01-01

    The continuum and emission-line spectrum of the narrow-line Seyfert 1 galaxy Ark 564 is used to investigate, for the first time, the physical conditions and structure of its narrow line region (NLR). For this purpose, composite models, accounting for the coupled effect of photoionization and shocks, are employed. The emission-line spectrum of Ark 564, which ranges from the ultraviolet to the near-infrared, shows a rich forbidden line spectrum. Strong emphasis is given to the study of the coronal line region. The diversity of physical conditions deduced from the observations requires multi-cloud models to reproduce the observed lines and continuum. We find that a combination of high velocity (Vs = 1500 km/s) shock-dominated clouds as well as low velocity (Vs = 150 km/s) radiation-dominated clouds explains the coronal lines, while the optical low-ionization lines are mainly explained by shock-dominated clouds. The results for Ark 564 are compared with those obtained for other Seyfert galaxies previously analyze...

  7. Asymmetry parameter of peaked Fano line shapes

    Science.gov (United States)

    Meierott, S.; Hotz, T.; Néel, N.; Kröger, J.

    2016-10-01

    The spectroscopic line shape of electronic and vibrational excitations is ubiquitously described by a Fano profile. In the case of nearly symmetric and peaked Fano line shapes, the fit of the conventional Fano function to experimental data leads to difficulties in unambiguously extracting the asymmetry parameter, which may vary over orders of magnitude without degrading the quality of the fit. Moreover, the extracted asymmetry parameter depends on initially guessed values. Using the spectroscopic signature of the single-Co Kondo effect on Au(110) the ambiguity of the extracted asymmetry parameter is traced to the highly symmetric resonance profile combined with the inevitable scattering of experimental data. An improved parameterization of the conventional Fano function is suggested that enables the nonlinear optimization in a reduced parameter space. In addition, the presence of a global minimum in the sum of squared residuals and thus the independence of start parameters may conveniently be identified in a two-dimensional plot. An angular representation of the asymmetry parameter is suggested in order to reliably determine uncertainty margins via linear error propagation.

  8. Development of narrow gap welding technology for extremely thick steel

    Science.gov (United States)

    Imai, K.; Saito, T.; Okumura, M.

    In the field of extremely thick steel, various narrow gap welding methods were developed on the basis of former welding methods and are used in practice. It is important to develop and improve automatic narrow gap welding, J edge preparation by gas cutting, the prevention of welding defects, wires for narrow gap welding and so on in order to expand the scope of application of the method. Narrow gap welding technologies are described, based on new concepts developed by Nippon Steel Corporation.

  9. Quasispecies evolution on a fitness landscape with a fluctuating peak

    Science.gov (United States)

    Nilsson, Martin; Snoad, Nigel

    2002-03-01

    A quasispecies evolving on a fitness landscape with a single peak of fluctuating height is studied. In the approximation that back mutations can be ignored, the rate equations can be solved analytically. It is shown that the error threshold on this class of dynamic landscapes is defined by the time average of the selection pressure. In the case of a periodically fluctuating fitness peak, we also study the phase shift and response amplitude of the previously documented low-pass filter effect. The special case of a small harmonic fluctuation is treated analytically.

  10. Optogenetic Excitation of Central Amygdala Amplifies and Narrows Incentive Motivation to Pursue One Reward Above Another

    OpenAIRE

    Robinson, Mike J. F.; Warlow, Shelley M.; Berridge, Kent C

    2014-01-01

    Choosing one reward above another is important for achieving adaptive life goals. Yet hijacked into excessive intensity in disorders such as addiction, single-minded pursuit becomes maladaptive. Here, we report that optogenetic channelrhodopsin stimulation of neurons in central nucleus of amygdala (CeA), paired with earning a particular sucrose reward in rats, amplified and narrowed incentive motivation to that single reward target. Therefore, CeA rats chose and intensely pursued only the las...

  11. Promoting L2 Vocabulary Learning through Narrow Reading

    Science.gov (United States)

    Kang, Eun Young

    2015-01-01

    Krashen (2004) has advocated that narrow reading, i.e., reading a series of texts addressing one specific topic, is an effective method to grow vocabulary. While narrow reading has been championed to have many advantages for L2 vocabulary learning, there remains a relative dearth of empirical studies that test the impact of narrow reading on L2…

  12. The Narrow Line Region of Narrow-Line Seyfert 1 Galaxies

    CERN Document Server

    Rodríguez-Ardila, A; Pastoriza, M G; Donzelli, C J

    2000-01-01

    This work studies the optical emission line properties and physical conditions of the narrow line region (NLR) of seven narrow-line Seyfert 1 galaxies (NLS1). Our results show that the flux carried out by the narrow component of H-beta is, on average, 50% of the total line flux. As a result, the [OIII] 5007/H-beta ratio emitted in the NLR varies from 1 to 5, instead of the universally adopted value of 10. This has strong implications for the required spectral energy distribution that ionizes the NLR gas. Photoionization models that consider a NLR composed of a combination of matter-bounded and ionization-bounded clouds are successful at explaining the low [OIII] 5007/H-beta ratio and the weakness of low-ionization lines of NLS1s. Variation of the relative proportion of these two type of clouds nicely reproduce the dispersion of narrow line ratios found among the NLS1 sample. Assuming similar physical model parameters of both NLS1s and the normal Seyfert 1 galaxy NGC 5548, we show that the observed differences...

  13. Narrow-Bicliques: Cryptanalysis of Full IDEA

    DEFF Research Database (Denmark)

    Khovratovich, D.; Leurent, G.; Rechberger, C.

    2012-01-01

    We apply and extend the recently introduced biclique framework to IDEA and for the first time describe an approach to noticeably speed-up key-recovery for the full 8.5 round IDEA.We also show that the biclique approach to block cipher cryptanalysis not only obtains results on more rounds, but also...... improves time and data complexities over existing attacks. We consider the first 7.5 rounds of IDEA and demonstrate a variant of the approach that works with practical data complexity. The conceptual contribution is the narrow-bicliques technique: the recently introduced independent-biclique approach...... the practical use of IDEA in any way, yet the techniques are practically verified to a large extent....

  14. Robotic chair at steep and narrow stairways

    Science.gov (United States)

    Imazato, Masahiro; Yamaguchi, Masahiro; Moromugi, Shunji; Ishimatsu, Takakazu

    2007-12-01

    A robotic chair is developed to support mobility of elderly and disabled people living in the house where steep and narrow stairways are installed. In order to deal with such mobility problem the developed robotic chair has a compact original configuration. The robotic chair vertically moves by actuation of electric cylinders and horizontally moves by push-pull operation given by a care-giver. In order to navigate safely every action of the chair is checked by the operator. Up-and-down motions of the robotic chair on the stairway are executed through combinations of motor and cylinder actuations. Performance of the robotic chair was evaluated through two kinds of experiments. The excellent ability of the robotic chair could be confirmed through these experiments.

  15. Narrow-angle astrometry with PRIMA

    CERN Document Server

    Sahlmann, J; Mérand, A; Zimmerman, N; Abuter, R; Chazelas, B; Delplancke, F; Henning, T; Kaminski, A; Köhler, R; Launhardt, R; Mohler, M; Pepe, F; Queloz, D; Quirrenbach, A; Reffert, S; Schmid, C; Schuhler, N; Schulze-Hartung, T

    2012-01-01

    The Extrasolar Planet Search with PRIMA project (ESPRI) aims at characterising and detecting extrasolar planets by measuring the host star's reflex motion using the narrow-angle astrometry capability of the PRIMA facility at the Very Large Telescope Interferometer. A first functional demonstration of the astrometric mode was achieved in early 2011. This marked the start of the astrometric commissioning phase with the purpose of characterising the instrument's performance, which ultimately has to be sufficient for exoplanet detection. We show results obtained from the observation of bright visual binary stars, which serve as test objects to determine the instrument's astrometric precision, its accuracy, and the plate scale. Finally, we report on the current status of the ESPRI project, in view of starting its scientific programme.

  16. Diluted magnetic semiconductors with narrow band gaps

    Science.gov (United States)

    Gu, Bo; Maekawa, Sadamichi

    2016-10-01

    We propose a method to realize diluted magnetic semiconductors (DMSs) with p - and n -type carriers by choosing host semiconductors with a narrow band gap. By employing a combination of the density function theory and quantum Monte Carlo simulation, we demonstrate such semiconductors using Mn-doped BaZn2As2 , which has a band gap of 0.2 eV. In addition, we found a nontoxic DMS Mn-doped BaZn2Sb2 , of which the Curie temperature Tc is predicted to be higher than that of Mn-doped BaZn2As2 , the Tc of which was up to 230 K in a recent experiment.

  17. Tissue characterization by using narrow band imaging

    Science.gov (United States)

    Gono, Kazuhiro

    2010-02-01

    NBI (Narrow Band Imaging) was first introduced in the market in 2005 as a technique enabling to enhance image contrast of capillaries on a mucosal surface(1). It is classified as an Optical-Digital Method for Image-Enhanced Endoscopy(2). To date, the application has widely spread not only to gastrointestinal fields such as esophagus, stomach and colon but also the organs such as bronchus and bladder. The main target tissue of NBI enhancement is capillaries. However, findings of many clinical studies conducted by endoscopy physicians have revealed that NBI observation enables to enhance more other structures in addition to capillaries. There is a close relationship between those enhanced structures and histological microstructure of a tissue. This report introduces the tissue microstructures enhanced by NBI and discusses the possibility of optimized illumination wavelength in observing living tissues.

  18. Properties of the narrow line Seyfert 1 galaxies revisited

    CERN Document Server

    Liu, Xiang; Su, Renzhi; Zhang, Zhen

    2016-01-01

    There is growing evidence to suggest that the black hole mass has been previously underestimated with the H$\\beta$ line width for certain active galactic nuclei (AGN). With the assumption of the flatter rather than isotropic velocity distribution of gases in the broad-line region of AGN, we investigated the properties of narrow line Seyfert 1 (NLS1) galaxies, like the black hole mass and the Eddington ratio, and compared with broad line Seyfert 1 (BLS1) galaxies. Since gamma-rays detected in a few NLS1s which favor a smaller viewing angle in NLS1s than BLS1s, with the projection effect we estimated the relative black hole mass and Eddington ratio for NLS1s and BLS1s. The result implies that the NLS1s and BLS1s have similar black hole masses and Eddington ratios, peaked at a larger black hole mass and lower Eddington ratio for the NLS1s than thought before. Furthermore, with applying the correction factor 6 of average black hole mass as derived from the modelling of both optical and UV data in radio loud NLS1s...

  19. Narrow-band Imagery of the ISM using the RCT

    Science.gov (United States)

    Walter, D. K.; Gelderman, R.; Guinan, E.; Howell, S.; Mattox, J. R.; McGruder, C. H., III; Davis, D.; Everett, M.

    2003-05-01

    We present the first results of imaging the Interstellar Medium (ISM) using narrow-band filters with the Robotically Controlled Telescope (RCT). The RCT is the recently refurbished 1.3-meter telescope at the Kitt Peak National Observatory. Details regarding the RCT can be found elsewhere at this meeting (Gelderman, R. et al.). Our filters are centered on diagnostic, nebular emission lines of the ions H+, He+, S+, N+ and O++. Objects of interest in the galactic and extragalactic ISM were observed including the starburst galaxy NGC 4449. Ionization ratio maps include [OIII]/Hβ, [NII]/Hα and the C(Hβ) extinction map from the ratio of Hα/Hβ. Electron densities are derived from the ratio of images taken through filters centered on the sulfur lines at 671.7 and 673.1 nm. Refurbishment of the RCT has been made possible by NASA NAG 58-762. Funding for filters and additional equipment has been made possible by NASA OSS NAG 5-10145 and NASA MU-SPIN NCC 5-534.

  20. The Meteorology of Storms that Produce Narrow Bipolar Events

    Science.gov (United States)

    Lang, Timothy J.; McCaul, Eugene W.; Cummer, Steven A.

    2013-01-01

    Narrow Bipolar Events (NBEs) are compact intracloud discharges that produce the most powerful lightning-related radio frequency signals that have been observed. However, their luminosity is below the threshold for detectability from current and past spaceborne optical sensors. NBEs have been loosely associated with convective intensity, but their occurrence tends to be highly localized in time and space within a thunderstorm, and there remain many questions about whether and to what extent they are significantly related to meteorological processes within thunderstorms. Using the North Alabama Lightning Mapping Array (NALMA), the National Lightning Detection Network, and available Doppler and polarimetric radar data, case studies will be presented for storm events that produced large numbers of NBEs (10s-100s) during their lifetimes. NBEs are documented via a method that identifies high peak power (>40-50 dBW) initial VHF sources within a specific altitude band in the upper levels of thunderstorms. The production of NBEs, including spatial and temporal variability, will be compared to the radar-inferred kinematic and microphysical structure and evolution of thunderstorms, as well as their NALMA- and NLDN-inferred electrical characteristics. The results should provide new insights into the relationships between NBEs and thunderstorm processes.

  1. Graphene-based tunable terahertz filter with rectangular ring resonator containing double narrow gaps

    Science.gov (United States)

    Su, Wei; Chen, Bingyan

    2017-09-01

    A plasmonic band-pass filter based on graphene rectangular ring resonator with double narrow gaps is proposed and numerically investigated by finite-difference time-domain (FDTD) simulations. For the filter with or without gaps, the resonant frequencies can be effectively adjusted by changing the width of the graphene nanoribbon, the coupling distance and chemical potential of graphene. In addition, by introducing narrow gaps in the rectangular ring resonators, it shows the single frequency filtering effect. Moreover, the structure also shows high sensitivity for different surrounding mediums. This work provides a novel method for designing all-optical integrated components in optical communication.

  2. Graphene-based tunable terahertz filter with rectangular ring resonator containing double narrow gaps

    Indian Academy of Sciences (India)

    WEI SU; BINGYAN CHEN

    2017-09-01

    A plasmonic band-pass filter based on graphene rectangular ring resonator with double narrow gaps is proposed and numerically investigated by finite-difference time-domain (FDTD) simulations. For the filter with or without gaps, the resonant frequencies can be effectively adjusted by changing the width of the graphene nanoribbon, the coupling distance and chemical potential of graphene. In addition, by introducing narrow gaps in the rectangular ring resonators, it shows the single frequency filtering effect. Moreover, the structure also shows high sensitivity fordifferent surrounding mediums. This work provides a novel method for designing all-optical integrated components in optical communication.

  3. The geomorphic structure of the runoff peak

    Directory of Open Access Journals (Sweden)

    R. Rigon

    2011-06-01

    Full Text Available This paper develops a theoretical framework to investigate the core dependence of peak flows on the geomorphic properties of river basins. Based on the theory of transport by travel times, and simple hydrodynamic characterization of floods, this new framework invokes the linearity and invariance of the hydrologic response to provide analytical and semi-analytical expressions for peak flow, time to peak, and area contributing to the peak runoff. These results are obtained for the case of constant-intensity hyetograph using the Intensity-Duration-Frequency (IDF curves to estimate extreme flow values as a function of the rainfall return period. Results show that, with constant-intensity hyetographs, the time-to-peak is greater than rainfall duration and usually shorter than the basin concentration time. Moreover, the critical storm duration is shown to be independent of rainfall return period as well as the area contributing to the flow peak. The same results are found when the effects of hydrodynamic dispersion are accounted for. Further, it is shown that, when the effects of hydrodynamic dispersion are negligible, the basin area contributing to the peak discharge does not depend on the channel velocity, but is a geomorphic propriety of the basin. As an example this framework is applied to three watersheds. In particular, the runoff peak, the critical rainfall durations and the time to peak are calculated for all links within a network to assess how they increase with basin area.

  4. [A peak recognition algorithm designed for chromatographic peaks of transformer oil].

    Science.gov (United States)

    Ou, Linjun; Cao, Jian

    2014-09-01

    In the field of the chromatographic peak identification of the transformer oil, the traditional first-order derivative requires slope threshold to achieve peak identification. In terms of its shortcomings of low automation and easy distortion, the first-order derivative method was improved by applying the moving average iterative method and the normalized analysis techniques to identify the peaks. Accurate identification of the chromatographic peaks was realized through using multiple iterations of the moving average of signal curves and square wave curves to determine the optimal value of the normalized peak identification parameters, combined with the absolute peak retention times and peak window. The experimental results show that this algorithm can accurately identify the peaks and is not sensitive to the noise, the chromatographic peak width or the peak shape changes. It has strong adaptability to meet the on-site requirements of online monitoring devices of dissolved gases in transformer oil.

  5. Automatic Narrow-Deep Feature Recognition for Mould Manufacturing

    Institute of Scientific and Technical Information of China (English)

    Zheng-Ming Chen; Kun-Jin He; Jing Liu

    2011-01-01

    There usually exist narrow-long-deep areas in mould needed to be machined in special machining. To identify the narrow-deep areas automatically, an automatic narrow-deep feature (NF) recognition method is put forward accordingly. First, the narrow-deep feature is defined innovatively in this field and then feature hint is extracted from the mould by the characteristics of narrow-deep feature. Second, the elementary constituent faces (ECF) of a feature are found on the basis of the feature hint. By means of extending and clipping the ECF, the feature faces are obtained incrementally by geometric reasoning. As a result, basic narrow-deep features (BNF) related are combined heuristically. The proposed NF recognition method provides an intelligent connection between CAD and CAPP for machining narrow-deep areas in mould.

  6. Experimental study on convective boiling heat transfer in narrow-gap annulus tubes

    Institute of Scientific and Technical Information of China (English)

    LI Bin; ZHAO Jian-Fu; ZHOU Fang-De; TANG Ze-Mei; HU Wen-Rui

    2004-01-01

    Since convective boiling or highly subcooled single-phase forced convection in micro-channels is an effective cooling mechanism with a wide range of applications, more experimental and theoretical studies are required to explain and verify the forced convection heat transfer phenomenon in narrow channels. In this experimental study, we model the convective boiling behavior of water with low latent heat substance Freon 113 (R-113), with the purpose of saving power consumption and visualizing experiments. Both heat transfer and pressure drop characteristics were measured in subcooled and saturated concentric narrow gap forced convection boiling. Data were obtained to qualitatively identify the effects of gap size, pressure, flow rate and wall superheat on boiling regimes and the transition between various regimes. Some significant differences from unconfined forced convection boiling were found,and also, the flow patterns in narrow vertical annulus tubes have been studied quantitatively.

  7. Artificial ground motion compatible with specified peak velocity and target spectrum

    Institute of Scientific and Technical Information of China (English)

    ZHAO Feng-xin; ZHANG Yu-shan

    2006-01-01

    In this paper, a method, which synthesizes the artificial ground motion compatible with the specified peak velocity as well as the target acceleration response spectrum, was proposed. In this method, firstly, an initial acceleration time history a(0)g (t), which satisfies the prescribed peak ground acceleration, the target spectral acceleration ST(ω,ζ ), and the specified intensity envelope, is generated by the traditional method that generates the response-spectrum-compatible artificial ground motion by modifying the Fourier amplitude spectrum in the frequency domain; secondly, a(0)g (t) is further modulated by superimposing narrow-band time histories upon it in the time domain to make its peak velocity, approach the target peak ground velocity, and at the same time to improve its fitting precision to the target spectrum. Numerical examples show that this algorithm boasts high calculation precisions.

  8. Do dark matter halos explain lensing peaks?

    Science.gov (United States)

    Zorrilla Matilla, José Manuel; Haiman, Zoltán; Hsu, Daniel; Gupta, Arushi; Petri, Andrea

    2016-10-01

    We have investigated a recently proposed halo-based model, Camelus, for predicting weak-lensing peak counts, and compared its results over a collection of 162 cosmologies with those from N-body simulations. While counts from both models agree for peaks with S /N >1 (where S /N is the ratio of the peak height to the r.m.s. shape noise), we find ≈50 % fewer counts for peaks near S /N =0 and significantly higher counts in the negative S /N tail. Adding shape noise reduces the differences to within 20% for all cosmologies. We also found larger covariances that are more sensitive to cosmological parameters. As a result, credibility regions in the {Ωm,σ8} are ≈30 % larger. Even though the credible contours are commensurate, each model draws its predictive power from different types of peaks. Low peaks, especially those with 2 important cosmological information in N-body data, as shown in previous studies, but Camelus constrains cosmology almost exclusively from high significance peaks (S /N >3 ). Our results confirm the importance of using a cosmology-dependent covariance with at least a 14% improvement in parameter constraints. We identified the covariance estimation as the main driver behind differences in inference, and suggest possible ways to make Camelus even more useful as a highly accurate peak count emulator.

  9. Electrocapillary instability of magnetic fluid peak

    CERN Document Server

    Mkrtchyan, Levon; Dikansky, Yuri

    2013-01-01

    The paper presents an experimental study of the capillary electrostatic instability occurring under effect of a constant electric field on a magnetic fluid individual peak. The peaks under study occur at disintegration of a magnetic fluid layer applied on a flat electrode surface under effect of a perpendicular magnetic field. The electrocapillary instability shows itself as an emission of charged drops jets from the peak point in direction of the opposing electrode. The charged drops emission repeats periodically and results in the peak shape pulsations. It is shown that a magnetic field affects the electrocapillary instability occurrence regularities and can stimulate its development. The critical electric and magnetic field strengths at which the instability occurs have been measured; their dependence on the peak size is shown. The hysteresis in the system has been studied; it consists in that the charged drops emission stops at a lesser electric (or magnetic) field strength than that of the initial occurr...

  10. Modular design of long narrow scintillating cells for ILC detector

    Energy Technology Data Exchange (ETDEWEB)

    Beznosko, D.; Blazey, G.; Dyshkant, A.; Maloney, J.; Rykalin, V.; /Northern Illinois U.; Schellpfeffer, J.; /Fermilab

    2005-09-01

    The experimental results for the narrow scintillating elements with effective area about 20 cm{sup 2} are reported. The elements were formed from the single piece of scintillator and were read out via wavelength shifting fibers with the MRS (Metal/Resistor/Semiconductor) photodiodes on both ends of each fiber. The formation of the cells from the piece of scintillator by using grooves is discussed. The cell performance was tested using the radioactive source by measuring the PMT current and a single rate after amplifier and discrimination with threshold at about three photo electrons in each channel and quad coincidences (double coincidences between sensors on each fiber and double coincidences between two neighboring fibers). This result is of high importance for large multi-channel systems, i.e. module may be used as an active element for calorimeter or muon system for the design of the future electron-positron linear collider detector because cell effective area can be smoothly enlarged or reduced (to 4 cm{sup 2} definitely).

  11. J peak extraction from non-standard ballistocardiography data: a preliminary study.

    Science.gov (United States)

    Xin Li; Ye Li

    2016-08-01

    In recent years, several advanced algorithms based on clustering, multi-method or data fusion approaches have been proposed to estimate heartbeat intervals from non-standard ballistocardiography (BCG) data. These advanced algorithms generally have higher computational complexity than J-peak based algorithms. This fact motivated us to study the problem of extracting J peaks from non-standard BCG data, because if this extraction can be realized, then a low-complexity J-peak based algorithm can be used to fast estimate heartbeat intervals from non-standard BCG data. We found that most of the energy in J peaks is contained in a relatively narrow frequency band, called J-peak band, and that the heartbeat harmonics outside the J-peak band can cause the non-standard BCG waveform. According to these findings, a FIR linear phase filter with the J-peak band as its pass-band is proposed. The experimental result demonstrates the ability of the proposed filter to extract J peaks from non-standard BCG data.

  12. Improved thermal stability and narrowed line width of photoluminescence from InGaN nanorod by ytterbium doping

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jingzhou; Wright, Jason; Kaya, S.; Jadwisienczak, W.M. [School of Electrical Engineering and Computer Science, Ohio University, Stocker Center, Athens OH 45701 (United States); Dasari, Kiran; Palai, Ratnakar [Department of Physics, University of Puerto Rico, San Juan, PR 00936 (United States); Cooper, Kevin; Thota, Venkata R.; Ingram, David C.; Stinaff, Eric A. [Department of Physics and Astronomy, Ohio University, Athens, OH 45701 (United States)

    2015-03-18

    Nanorod of in situ Yb-doped InGaN and undoped InGaN have been grown on (0001) sapphire substrates by plasma assisted molecular beam epitaxy (MBE). Selected regions on Yb-doped InGaN sample show single dominant near band edge emission (NBE) in green, yellow or orange color due to the variation of In content. Temperature dependent PL peak energy of InGaN nanorod shows the characteristic S -shaped behavior indicating the presents of strong exciton localization energy in undoped InGaN nanorod. The exciton localization energy reduced significantly after incorporating Yb into InGaN, giving rise to damping of the S-shape profile amplitude and narrowing of the PL line width from ∝20 meV to ∝12 meV at 11 K. It is proposed that the improved PL thermal stability and the PL line width in Yb-doped InGaN nanorod is affected by the Yb gettering effect. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Diging simulation of a narrow trench

    Science.gov (United States)

    Anghelache, D. G.; Goanta, A. M.

    2016-08-01

    In this paper, we realized digging process simulation for a narrow trench using special equipment located at a mini excavator. These types of machines digging perform the longitudinal direction to the direction of travel, making trenches with widths of 0.4 m and depths of 3.5 -7.0 m. These are necessary for the location of underground cables or draining water in agriculture. For Parametric modelling of parts included in ensemble has used software from Siemens NX 7.5, we produce sketches of each piece, using following commands: Sketch, Profile (Line), Arc, Circle, Quick Trim Quick Extend, Constraints. Depending on the layout of each piece can also use other commands such as: Chamfer, Rotate, Mirror Curve, Offset Curve, etc. After completion of sketch and dimensioning commands was: Extrude, Revolve, and at this stage the play may various modifications such as drilling, removal of certain volumes of piece showing various forms or change the appearance of surfaces (thread cutting, bevelling). This paper was realized with this parametric modelling software because presents major advantages including: control over the design, making design speed and increasing productivity; increasing product quality, reducing design risk recovery and time work, less human effort and reduced financial resources throughout the process.

  14. Narrow and broad senses on salinity scale

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The narrow sense and applicable limit of Practical Salinity Scale 1978 (PSS78) and volumetric titration using silver nitrate to measure the salinity of non-conservative oceanwater are discussed.The salinity obtained by electrical conductivity method and chlorinity salinity method obviously deviates from the absolute salinity (SA). The Density Salinity Scale (DSS98) proposed by the writers can be extensively used in conservative and non-conservative water samples.The merits of the density salinity scale are as follows,(1) The Density Salinity Scale is only related to seawater mass and its buoyant effect, and is not influenced by the variation in seawater composition, and therefore, has high reliability, and repeatability for salinity determination.(2) The salinity values measured by the DSS98 have a conservative property. For oceanwater samples the salinity values are the same as those determined by the PSS78; for non-conservative water samples (e.g. samples from industrial sources), the salinity values are close to the absolute salinity values in comparison with those measured by the PSS78 and the Knudsen method.(3)For a solution with given solute mass, the solution concentration can be converted into the corresponding salinity by the Density Salinity Scale using the expansion coefficient of the solution and the calibration coefficient of the partial molar volume of the solute.

  15. A wide-angle metamaterial narrow-band-stop filter for 532 nm wavelength green light

    CERN Document Server

    Yue, Liyang; Yan, Bing; Tung, Nguyen Thanh; Lam, Vu Dinh; Wang, Zengbo

    2016-01-01

    Traditional optical interference narrow-band-stop filters do not possess wide-angle property, because peaks and troughs of filter spectrum would be moved at a non-normal angle of incidence (AOI), which could result in functional failure in particular cases, e.g. blocking of laser for pilot in cockpit during premeditated laser pointer direct. For this reason, we designed a wide-angle metamaterial narrow-band-stop filter assembled by cross shaped units to block 532 nm green light, which is firstly reported in the world. Unnecessary shift of spectrum caused by AOI change is effectively inhibited, and angular tolerance of wide-angle capability achieves to 35 degrees non-normal AOIs.

  16. Negative and Superluminal Group Velocity Propagation with Narrow Pulse in a Coaxial Photonic Crystal

    Institute of Scientific and Technical Information of China (English)

    OU Xiao-Juan; ZHOU Wei; LI Lin; TENG Li-Hu; FENG Bao-Ying; ZHENG Sheng-Feng; WANG Feng-Wei

    2007-01-01

    We investigate the propagation of electric signal along a spatially periodic impedance mismatched transmission line group. Anomalous dispersion is caused by the periodically mismatched impedance structure and a forbidden band appears near 8 MHz in transmission. The group velocity of the amplitude-modulated signal is augmented up to infinity, even -3.89c (c the speed of light in vacuum) in the forbidden region with the amplitude of the modulated signal increasing. When the carrier sinusoid signal is modulated in amplitude by the modulating sinusoid signal, of which the peak is superimposed with a narrow pulse at fivefold frequency, the superluminal group velocity also occurs. The experiment failed to show whether the propagation velocity of narrow pulse exceeds c or not.

  17. Peak Dose Assessment for Proposed DOE-PPPO Authorized Limits

    Energy Technology Data Exchange (ETDEWEB)

    Maldonado, Delis [Oak Ridge Institute for Science and Education, Oak Ridge, TN (United States). Independent Environmental Assessment and Verification Program

    2012-06-01

    The Oak Ridge Institute for Science and Education (ORISE), a U.S. Department of Energy (DOE) prime contractor, was contracted by the DOE Portsmouth/Paducah Project Office (DOE-PPPO) to conduct a peak dose assessment in support of the Authorized Limits Request for Solid Waste Disposal at Landfill C-746-U at the Paducah Gaseous Diffusion Plant (DOE-PPPO 2011a). The peak doses were calculated based on the DOE-PPPO Proposed Single Radionuclides Soil Guidelines and the DOE-PPPO Proposed Authorized Limits (AL) Volumetric Concentrations available in DOE-PPPO 2011a. This work is provided as an appendix to the Dose Modeling Evaluations and Technical Support Document for the Authorized Limits Request for the C-746-U Landfill at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky (ORISE 2012). The receptors evaluated in ORISE 2012 were selected by the DOE-PPPO for the additional peak dose evaluations. These receptors included a Landfill Worker, Trespasser, Resident Farmer (onsite), Resident Gardener, Recreational User, Outdoor Worker and an Offsite Resident Farmer. The RESRAD (Version 6.5) and RESRAD-OFFSITE (Version 2.5) computer codes were used for the peak dose assessments. Deterministic peak dose assessments were performed for all the receptors and a probabilistic dose assessment was performed only for the Offsite Resident Farmer at the request of the DOE-PPPO. In a deterministic analysis, a single input value results in a single output value. In other words, a deterministic analysis uses single parameter values for every variable in the code. By contrast, a probabilistic approach assigns parameter ranges to certain variables, and the code randomly selects the values for each variable from the parameter range each time it calculates the dose (NRC 2006). The receptor scenarios, computer codes and parameter input files were previously used in ORISE 2012. A few modifications were made to the parameter input files as appropriate for this effort. Some of these changes

  18. Narrowing of the ITCZ in a warming climate: Physical mechanisms

    Science.gov (United States)

    Byrne, Michael P.; Schneider, Tapio

    2016-11-01

    The Intertropical Convergence Zone (ITCZ) narrows in response to global warming in both observations and climate models. However, a physical understanding of this narrowing is lacking. Here we show that the narrowing of the ITCZ in simulations of future climate is related to changes in the moist static energy (MSE) budget. MSE advection by the mean circulation and MSE divergence by transient eddies tend to narrow the ITCZ, while changes in net energy input to the atmosphere and the gross moist stability tend to widen the ITCZ. The narrowing tendency arises because the meridional MSE gradient strengthens with warming, whereas the largest widening tendency is due to increasing shortwave heating of the atmosphere. The magnitude of the ITCZ narrowing depends strongly on the gross moist stability and clouds, emphasizing the need to better understand these fundamental processes in the tropical atmosphere.

  19. Peak load arrangements : Assessment of Nordel guidelines

    Energy Technology Data Exchange (ETDEWEB)

    2009-07-01

    Two Nordic countries, Sweden and Finland, have legislation that empowers the TSO to acquire designated peak load resources to mitigate the risk for shortage situations during the winter. In Denmark, the system operator procures resources to maintain a satisfactory level of security of supply. In Norway the TSO has set up a Regulation Power Option Market (RKOM) to secure a satisfactory level of operational reserves at all times, also in winter with high load demand. Only the arrangements in Finland and Sweden fall under the heading of Peak Load Arrangements defined in Nordel Guidelines. NordREG has been invited by the Electricity Market Group (EMG) to evaluate Nordel's proposal for 'Guidelines for transitional Peak Load Arrangements'. The EMG has also financed a study made by EC Group to support NordREG in the evaluation of the proposal. The study has been taken into account in NordREG's evaluation. In parallel to the EMG task, the Swedish regulator, the Energy Markets Inspectorate, has been given the task by the Swedish government to investigate a long term solution of the peak load issue. The Swedish and Finnish TSOs have together with Nord Pool Spot worked on finding a harmonized solution for activation of the peak load reserves in the market. An agreement accepted by the relevant authorities was reached in early January 2009, and the arrangement has been implemented since 19th January 2009. NordREG views that the proposed Nordel guidelines have served as a starting point for the presently agreed procedure. However, NordREG does not see any need to further develop the Nordel guidelines for peak load arrangements. NordREG agrees with Nordel that the market should be designed to solve peak load problems through proper incentives to market players. NordREG presumes that the relevant authorities in each country will take decisions on the need for any peak load arrangement to ensure security of supply. NordREG proposes that such decisions should be

  20. Fixed region of nondistensibility after coarctation repair : In vitro validation of its influence on Doppler peak velocities

    NARCIS (Netherlands)

    Verhaaren, H; De Mey, S; Coomans, [No Value; Segers, P; De Wolf, D; Matthys, D; Verdonck, P

    2001-01-01

    After coarctectomy, local loss of distensibility is noted in addition to mild anatomic narrowing. We hypothesize that the increased Doppler peak velocities measured at the aortic isthmus in these patients partly reflect obstruction secondary to the stiff surgical scar. The hypothesis was studied in

  1. Laser frequency bandwidth narrowing by photorefractive two-beam coupling.

    Science.gov (United States)

    Chomsky, D; Sternklar, S; Zigler, A; Jackel, S

    1992-04-01

    We present a theoretical analysis and experimental demonstration of a new method for spectral narrowing of laser radiation. The bandwidth narrowing is experienced by a laser beam subjected to a photorefractive two-beam coupling process. Contrary to the conventional method of frequency filtering by a Fabry-Perot étalon, this technique has no intrinsic finesse limitation on its resolution. A factor of 2 in frequency bandwidth narrowing is achieved with an argon-ion laser.

  2. Constitutive spectral EEG peaks in the gamma range: suppressed by sleep, reduced by mental activity and resistant to sensory stimulation

    Directory of Open Access Journals (Sweden)

    Tyler Samuel Grummett

    2014-11-01

    Full Text Available Objective: In a systematic study of gamma activity in neuro-psychiatric disease, we unexpectedly observed distinctive, apparently persistent, electroencephalogram (EEG spectral peaks in the gamma range (25-100 Hz. Our objective, therefore, was to examine the incidence, distribution and some of the characteristics of these peaks.Methods: High sample-rate, 128-channel, EEG was recorded in 603 volunteers (510 with neuropsychiatric disorders, 93 controls, whilst performing cognitive tasks, and converted to power spectra. Peaks of spectral power, including in the gamma range, were determined algorithmically for all electrodes. To determine if peaks were stable, 24-hour ambulatory recordings were obtained from 16 subjects with peaks. In 10 subjects, steady-state responses to stimuli at peak frequency were compared with off-peak-frequency stimulation to determine if peaks were a feature of underlying network resonances and peaks were evaluated with easy and hard versions of oddball tasks to determine if peaks might be influenced by mental effort.Results: 57 % of subjects exhibited peaks > 2 dB above trough power at or above 25 Hz. Larger peaks (> 5 dB were present in 13 % of subjects. Peaks were distributed widely over the scalp, more frequent centrally. Peaks were present through the day and were suppressed by slow-wave-sleep. Steady-state responses were the same with on- or off-peak sensory stimulation. In contrast, mental effort resulted in reductions in power and frequency of gamma peaks, although the suppression did not correlate with level of effort.Conclusions: Gamma EEG can be expressed constitutively as concentrations of power in narrow or wide frequency bands that play an, as yet, unknown role in cognitive activity.Significance: These findings expand the described range of rhythmic EEG phenomena. In particular, in addition to evoked, induced and sustained gamma band activity, gamma activity can be present constitutively in spectral peaks.

  3. Bayesian peak picking for NMR spectra.

    Science.gov (United States)

    Cheng, Yichen; Gao, Xin; Liang, Faming

    2014-02-01

    Protein structure determination is a very important topic in structural genomics, which helps people to understand varieties of biological functions such as protein-protein interactions, protein-DNA interactions and so on. Nowadays, nuclear magnetic resonance (NMR) has often been used to determine the three-dimensional structures of protein in vivo. This study aims to automate the peak picking step, the most important and tricky step in NMR structure determination. We propose to model the NMR spectrum by a mixture of bivariate Gaussian densities and use the stochastic approximation Monte Carlo algorithm as the computational tool to solve the problem. Under the Bayesian framework, the peak picking problem is casted as a variable selection problem. The proposed method can automatically distinguish true peaks from false ones without preprocessing the data. To the best of our knowledge, this is the first effort in the literature that tackles the peak picking problem for NMR spectrum data using Bayesian method.

  4. Osteoporosis: Peak Bone Mass in Women

    Science.gov (United States)

    ... not supported by your browser. Home Osteoporosis Women Osteoporosis: Peak Bone Mass in Women Publication available in: ... drug products. NIH Pub. No. 15-7891 NIH Osteoporosis and Related Bone Diseases ~ National Resource Center 2 ...

  5. Bayesian Peak Picking for NMR Spectra

    KAUST Repository

    Cheng, Yichen

    2014-02-01

    Protein structure determination is a very important topic in structural genomics, which helps people to understand varieties of biological functions such as protein-protein interactions, protein–DNA interactions and so on. Nowadays, nuclear magnetic resonance (NMR) has often been used to determine the three-dimensional structures of protein in vivo. This study aims to automate the peak picking step, the most important and tricky step in NMR structure determination. We propose to model the NMR spectrum by a mixture of bivariate Gaussian densities and use the stochastic approximation Monte Carlo algorithm as the computational tool to solve the problem. Under the Bayesian framework, the peak picking problem is casted as a variable selection problem. The proposed method can automatically distinguish true peaks from false ones without preprocessing the data. To the best of our knowledge, this is the first effort in the literature that tackles the peak picking problem for NMR spectrum data using Bayesian method.

  6. Amplification of postwildfire peak flow by debris

    Science.gov (United States)

    Kean, J. W.; McGuire, L. A.; Rengers, F. K.; Smith, J. B.; Staley, D. M.

    2016-08-01

    In burned steeplands, the peak depth and discharge of postwildfire runoff can substantially increase from the addition of debris. Yet methods to estimate the increase over water flow are lacking. We quantified the potential amplification of peak stage and discharge using video observations of postwildfire runoff, compiled data on postwildfire peak flow (Qp), and a physically based model. Comparison of flood and debris flow data with similar distributions in drainage area (A) and rainfall intensity (I) showed that the median runoff coefficient (C = Qp/AI) of debris flows is 50 times greater than that of floods. The striking increase in Qp can be explained using a fully predictive model that describes the additional flow resistance caused by the emergence of coarse-grained surge fronts. The model provides estimates of the amplification of peak depth, discharge, and shear stress needed for assessing postwildfire hazards and constraining models of bedrock incision.

  7. Peak Vegetation Growth 2000 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2000 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  8. Peak Vegetation Growth 2004 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2004 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  9. Peak Vegetation Growth 1999 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1999 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  10. Peak Vegetation Growth 1993 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1993 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  11. Peak Vegetation Growth 1994 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1994 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  12. Peak Vegetation Growth 1995 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1995 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  13. Peak Vegetation Growth 1998 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1998 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  14. Peak Vegetation Growth 2001 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2001 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  15. Peak Vegetation Growth 2003 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2003 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  16. Peak Vegetation Growth 1997 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1997 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  17. Peak Vegetation Growth 1990 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1990 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  18. Peak Vegetation Growth 1996 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 1996 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  19. Peak Vegetation Growth 2005 - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of 2005 peak vegetation growth for Alaska and the conterminous United States. The nominal spatial resolution is 1 kilometer and the map...

  20. Tectonics, Climate and Earth's highest peaks

    Science.gov (United States)

    Robl, Jörg; Prasicek, Günther; Hergarten, Stefan

    2016-04-01

    Prominent peaks characterized by high relief and steep slopes are among the most spectacular morphological features on Earth. In collisional orogens they result from the interplay of tectonically driven crustal thickening and climatically induced destruction of overthickened crust by erosional surface processes. The glacial buzz-saw hypothesis proposes a superior status of climate in limiting mountain relief and peak altitude due to glacial erosion. It implies that peak altitude declines with duration of glacial occupation, i.e., towards high latitudes. This is in strong contrast with high peaks existing in high latitude mountain ranges (e.g. Mt. St. Elias range) and the idea of peak uplift due to isostatic compensation of spatially variable erosional unloading an over-thickened orogenic crust. In this study we investigate landscape dissection, crustal thickness and vertical strain rates in tectonically active mountain ranges to evaluate the influence of erosion on (latitudinal) variations in peak altitude. We analyze the spatial distribution of serval thousand prominent peaks on Earth extracted from the global ETOPO1 digital elevation model with a novel numerical tool. We compare this dataset to crustal thickness, thickening rate (vertical strain rate) and mean elevation. We use the ratios of mean elevation to peak elevation (landscape dissection) and peak elevation to crustal thickness (long-term impact of erosion on crustal thickness) as indicators for the influence of erosional surface processes on peak uplift and the vertical strain rate as a proxy for the mechanical state of the orogen. Our analysis reveals that crustal thickness and peak elevation correlate well in orogens that have reached a mechanically limited state (vertical strain rate near zero) where plate convergence is already balanced by lateral extrusion and gravitational collapse and plateaus are formed. On the Tibetan Plateau crustal thickness serves to predict peak elevation up to an altitude

  1. Cosmic Microwave Background Acoustic Peak Locations

    CERN Document Server

    Pan, Zhen; Mulroe, Brigid; Narimani, Ali

    2016-01-01

    The Planck collaboration has measured the temperature and polarization of the cosmic microwave background well enough to determine the locations of eight peaks in the temperature (TT) power spectrum, five peaks in the polarization (EE) power spectrum and twelve extrema in the cross (TE) power spectrum. The relative locations of these extrema give a striking, and beautiful, demonstration of what we expect from acoustic oscillations in the plasma; e.g., that EE peaks fall half way between TT peaks. We expect this because the temperature map is predominantly sourced by temperature variations in the last scattering surface, while the polarization map is predominantly sourced by gradients in the velocity field, and the harmonic oscillations have temperature and velocity 90 degrees out of phase. However, there are large differences in expectations for extrema locations from simple analytic models vs. numerical calculations. Here we quantitatively explore the origin of these differences in gravitational potential tr...

  2. Do dark matter halos explain lensing peaks?

    CERN Document Server

    Matilla, José Manuel Zorrilla; Hsu, Daniel; Gupta, Arushi; Petri, Andrea

    2016-01-01

    We have investigated a recently proposed halo-based model, Camelus, for predicting weak-lensing peak counts, and compared its results over a collection of 162 cosmologies with those from N-body simulations. While counts from both models agree for peaks with $\\mathcal{S/N}>1$ (where $\\mathcal{S/N}$ is the ratio of the peak height to the r.m.s. shape noise), we find $\\approx 50\\%$ fewer counts for peaks near $\\mathcal{S/N}=0$ and significantly higher counts in the negative $\\mathcal{S/N}$ tail. Adding shape noise reduces the differences to within $20\\%$ for all cosmologies. We also found larger covariances that are more sensitive to cosmological parameters. As a result, credibility regions in the $\\{\\Omega_m, \\sigma_8\\}$ are $\\approx 30\\%$ larger. Even though the credible contours are commensurate, each model draws its predictive power from different types of peaks. Low peaks, especially those with $23)$. Our results confirm the importance of using a cosmology-dependent covariance with at least a 14\\% improveme...

  3. The Nature of Double-Peaked [O III] Active Galactic Nuclei

    CERN Document Server

    Fu, Hai; Myers, Adam D; Stockton, Alan; Djorgovski, S G; Aldering, G; Rich, Jeffrey A

    2011-01-01

    Active galactic nuclei (AGNs) with double-peaked [O III] lines are suspected to be sub-kpc or kpc-scale binary AGNs. However, pure gas kinematics can produce the same double-peaked line profile in spatially integrated spectra. Here we combine integral-field spectroscopy and high-resolution imaging of 42 double-peaked [O III] AGNs from Sloan Digital Sky Survey to investigate the constituents of the population. We find two binary AGNs where the line-splitting is driven by the orbital motion of the merging nuclei. Such objects account for only ~2% of the double-peaked AGNs. Almost all (~98%) of the double-peaked AGNs were selected because of gas kinematics; and half of those show spatially resolved narrow-line regions that extend 4-20 kpc from the nuclei. Serendipitously, we find two spectrally unresolved binary AGNs where gas kinematics produced the double-peaked [O III] lines. The relatively frequent serendipitous discoveries indicate that only ~1% of binary AGNs would appear double-peaked in Sloan spectra and...

  4. Unusual Double-peaked Emission in the SDSS Quasar J093201.60+031858.7

    CERN Document Server

    Barrows, R Scott; Kennefick, Daniel; Kennefick, Julia

    2010-01-01

    We examine spectral properties of the SDSS quasar J093201.60+031858.7, in particular the presence of strong blue peaks in the Balmer emission lines offset from the narrow lines by approximately 4200 km s$^{-1}$. Asymmetry in the broad central component of the H$\\beta$ line indicates the presence of a double-peaked emitter. However, the strength and sharpness of the blue H$\\beta$ and blue H$\\gamma$ peaks make this quasar spectrum unique amongst double-peaked emitters identified from SDSS spectra. We fit a disk model to the H$\\beta$ line and compare this object with other unusual double-peaked quasar spectra, particularly candidate binary supermassive black holes (SMBHs). Under the binary SMBH scenario, we test the applicability of a model in which a second SMBH may produce the strong blue peak in the Balmer lines of a double-peaked emitter. If there were only one SMBH, a circular, Keplerian disk model fit would be insufficient, indicating some sort of asymmetry is required to produce the strength of the blue p...

  5. Observation of linewidth narrowing due to a spontaneously generated coherence effect

    Institute of Scientific and Technical Information of China (English)

    Tian Si-Cong; Gao Jin-Yue; Wang Chun-Liang; Kang Zhi-Hui; Yang Xiu-Bin; Wan Ren-Gang; Zhang Xiao-Jun; Zhang Hang; Jiang Yun; Cui Hai-Ning

    2012-01-01

    We investigate the resonance fluorescence spectrum of an atomic three-level ladder system driven by two laser fields.We show that such a system emulates to a large degree a V-type atom with parallel dipole moments—the latter being a system that exhibits spontaneously generated coherence and can display ultrasharp spectral lines.We find a suitable energy scheme in a 85Rb atom and experimentally observe the narrowing of the central peak in a rubidium atomic beam.The corresponding spectrum can convincingly demonstrate the existence of spontaneously generated coherence.

  6. Simultaneous estimation of noise variance and number of peaks in Bayesian spectral deconvolution

    CERN Document Server

    Tokuda, Satoru; Okada, Masato

    2016-01-01

    Heuristic identification of peaks from noisy complex spectra often leads to misunderstanding physical and chemical properties of matter. In this paper, we propose a framework based on Bayesian inference, which enables us to separate multi-peak spectra into single peaks statistically and is constructed in two steps. The first step is estimating both noise variance and number of peaks as hyperparameters based on Bayes free energy, which generally is not analytically tractable. The second step is fitting the parameters of each peak function to the given spectrum by calculating the posterior density, which has a problem of local minima and saddles since multi-peak models are nonlinear and hierarchical. Our framework enables escaping from local minima or saddles by using the exchange Monte Carlo method and calculates Bayes free energy. We discuss a simulation demonstrating how efficient our framework is and show that estimating both noise variance and number of peaks prevents overfitting, overpenalizing, and misun...

  7. A method for the separation of overlapping peaks in cyclic voltammetry by means of semidifferential transformation

    NARCIS (Netherlands)

    Palys, M.J.; Palys, Marcin; Korba, Tomas; Bos, M.; van der Linden, W.E.

    1991-01-01

    A method for extracting single peaks from complex linear sweep and cyclic voltamperograms is presented. Voltamperograms are transformed by means of semidifferentiation, then all undesired peaks are removed from the semiderivative curve and replaced by calculated baselines. The resulting curve is

  8. Vortex formation in magnetic narrow rings

    Science.gov (United States)

    Bland, J. A. C.

    2002-03-01

    Underlying the current interest in magnetic elements is the possibility such systems provide both for the study of fundamental phenomena in magnetism (such as domain wall trapping and spin switching) and for technological applications, such as high density magnetic storage or magnetic random access memories (MRAM). One key issue is to control the magnetic switching precisely. To achieve this one needs first to have a well defined and reproducible remanent state, and second the switching process itself must be simple and reproducible. Among the many studied geometries, rings are shown to exhibit several advantages over other geometries, in that they show relatively simple stable magnetic states at remanence, with fast and simple magnetisation switching mechanisms. This is borne out of our systematic investigation of the magnetic properties of epitaxial and polycrystalline Co rings, where both the static, dynamic and transport properties have been studied. Magnetic measurements and micromagnetic simulations show that for appropriate ring structures a two step switching process occurs at high fields, indicating the existence of two different stable states. In addition to the vortex state, which occurs at intermediate fields, we have identified a new bi-domain state, which we term the `onion state', corresponding to opposite circulation of the magnetisation in each half of the ring. The magnetic elements were fabricated using a new technique based on the pre-patterning of Si ring structures and subsequent epitaxial growth of Cu/Co/Cu sandwich films on top of the Si elements. This technique has allowed the growth of epitaxial fcc Co(001) structures and in contrast to conventional lithographic methods, no damage to the magnetic layer structure is introduced by the patterning process [1,2]. We have studied the magnetic switching properties of arrays of narrow Co(100) epitaxial ring magnets, with outer diameters between 1 μm and 2 μm, varying inner diameters and varying

  9. Narrow-K-Band Observations of the GJ 1214 System

    CERN Document Server

    Colon, Knicole D

    2013-01-01

    GJ 1214 is a nearby M dwarf star that hosts a transiting super-Earth-size planet, making this system an excellent target for atmospheric studies. Most studies find that the transmission spectrum of GJ 1214b is flat, which favors either a high mean molecular weight or cloudy/hazy hydrogen (H) rich atmosphere model. Photometry at short wavelengths (< 0.7 micron) and in the K-band can discriminate the most between these different atmosphere models for GJ 1214b, but current observations do not have sufficiently high precision. We present photometry of seven transits of GJ 1214b through a narrow K-band (2.141 micron) filter with the Wide Field Camera on the 3.8 m United Kingdom Infrared Telescope. Our photometric precision is typically 1.7x10^-3 (for a single transit), comparable with other ground-based observations of GJ 1214b. We measure a planet-star radius ratio of 0.1158+/-0.0013, which, along with other studies, also supports a flat transmission spectrum for GJ 1214b. Since this does not exclude a scenari...

  10. Mechanical filtering for narrow-band hearing in the weta.

    Science.gov (United States)

    Lomas, Kathryn; Montealegre-Z, Fernando; Parsons, Stuart; Field, Larry H; Robert, Daniel

    2011-03-01

    This paper constitutes a major attempt to associate tympanic deflections with the mechanoreceptor organ location in an acoustic insect. The New Zealand tree weta (Hemideina thoracica) has tympanal ears located on each of the prothoracic tibiae. The tympana exhibit a sclerotized oval plate, membranous processes bulging out from the tibial cuticle and many loosely suspended ripples. We used microscanning laser Doppler vibrometry to determine how such a tympanal membrane vibrates in response to sound and whether the sclerotized region plays a role in hearing. The tympanum displays a single resonance at the calling frequency of the male, an unusual example of an insect tympana acting as a narrow bandpass filter. Both tympana resonate in phase with the stimulus and with each other. Histological sections show that the tympanal area is divided into two distinct regions, as in other ensiferans. An oval plate lies in the middle of a thickened region and is surrounded by a transparent and uniformly thin region. It is hinged dorsally to the tympanal rim and thus resembles the model of a 'hinged flap'. The thickened region appears to act as a damping mass on the oscillation of the thin region, and vibration displacement is reduced in this area. The thinner area vibrates with higher amplitude, inducing mechanical pressure on the dorsal area adjacent to the crista acustica. We present a new model showing how the thickened region might confer a mechanical gain onto the activation of the crista acustica sensory neurons during the sound-induced oscillations.

  11. Laser-induced damage of 1064-nm narrow-band interference filters under different laser modes

    Institute of Scientific and Technical Information of China (English)

    Weidong Gao(高卫东); Hongbo He(贺洪波); Jianda Shao(邵建达); Zhengxiu Fan(范正修)

    2004-01-01

    The laser-induced damage behavior of narrow-band interference filters was investigated with a Nd:YAG laser at 1064 nm under single-pulse mode and free-running laser mode.The absorption measurement of such coatings has been performed by surface thermal lensing(STL)technique.The relationship between damage morphology and absorption under the two different laser modes was studied in detail.The explanation was given by the standing-wave distribution theory.

  12. Correlation in narrow nanorods: a variational potential-configuration interaction scheme

    Energy Technology Data Exchange (ETDEWEB)

    Planelles, J; Climente, J I; Royo, M; Movilla, J L [Departament de Quimica-Fisica i AnalItica, UJI, Box 224, E-12080 Castello (Spain)], E-mail: josep.planelles@qfa.uji.es

    2009-05-27

    Full configuration interaction calculations for two electrons in narrow semiconductor nanorods are carried out employing different orbital basis sets. It is shown that the usual configurations built from single-particle states cannot yield a correct singlet-triplet energetic order regardless of the basis size, as they miss the correlation energy. Mean-field optimized orbitals partially correct this drawback. A new approach is introduced, based on a simple variational procedure, which yields robust results.

  13. Uniqueness plots: A simple graphical tool for identifying poor peak fits in X-ray photoelectron spectroscopy

    Science.gov (United States)

    Singh, Bhupinder; Diwan, Anubhav; Jain, Varun; Herrera-Gomez, Alberto; Terry, Jeff; Linford, Matthew R.

    2016-11-01

    Peak fitting is an essential part of X-ray photoelectron spectroscopy (XPS) narrow scan analysis, and the Literature contains both good and bad examples of peak fitting. A common cause of poor peak fitting is the inclusion of too many fit parameters, often without a sound chemical and/or physical basis for them, and/or the failure to reasonably constrain them. Under these conditions, fit parameters are often correlated, and therefore lacking in statistical meaning. Here we introduce the uniqueness plot as a simple graphical tool for identifying bad peak fits in XPS, i.e., fit parameter correlation. These plots are widely used in spectroscopic ellipsometry. We illustrate uniqueness plots with two data sets: a C 1s narrow scan from ozone-treated carbon nanotube forests and an Si 2p narrow scan from an air-oxidized silicon wafer. For each fit, we consider different numbers of parameters and constraints on them. As expected, the uniqueness plots are parabolic when fewer fit parameters and/or more constraints are applied. However, they fan out and eventually become horizontal lines as more unconstrained parameters are included in the fits. Uniqueness plots are generated by plotting the chi squared (χ2) value for a fit vs. a systematically varied value of a parameter in the fit. The Abbe criterion is also considered as a figure of merit for uniqueness plots in the Supporting Information. We recommend that uniqueness plots be used by XPS practitioners for identifying inappropriate peak fits.

  14. The Case for the Narrow View of Reading

    Science.gov (United States)

    Kamhi, Alan G.

    2009-01-01

    Purpose: This prologue reiterates the case for the narrow view of reading as a solution to the persistently high levels of reading failure that occurs in our schools and provides a brief summary of the 5 response articles. Method: The arguments that support the narrow view of reading are presented and the respondents are introduced. Conclusion:…

  15. Narrow band tuning with small long pulse excimer lasers

    Energy Technology Data Exchange (ETDEWEB)

    Sze, R.C.; Kurnit, N.; Watkins, D.; Bigio, I.

    1985-12-01

    We discuss frequency narrowing and tuning with simple dispersion elements with small long-pulse excimer lasers. The improved performance over short-pulse lasers is discussed and attributed to the increased number of round trips. A physical model of the dynamics of line narrowing is presented.

  16. Bayesian Face Recognition and Perceptual Narrowing in Face-Space

    Science.gov (United States)

    Balas, Benjamin

    2012-01-01

    During the first year of life, infants' face recognition abilities are subject to "perceptual narrowing", the end result of which is that observers lose the ability to distinguish previously discriminable faces (e.g. other-race faces) from one another. Perceptual narrowing has been reported for faces of different species and different races, in…

  17. Channel Narrowing and Channel Reset: Effects of a Large Flood on the Vegetated, Narrowing Rio Grande

    Science.gov (United States)

    Dean, D. J.; Schmidt, J. C.

    2009-12-01

    In September 2008, heavy precipitation from a tropical storm in the Sierra Madre Occidental, MX, produced large amounts of stream flow to the Rio Conchos and lower Rio Grande. This flood was well publicized in the media due to the widespread flooding in Ojinaga, Chih., and Presidio, TX. Gage records indicate that this flood had an approximate recurrence of 15 years as measured on the Rio Grande near Presidio. Nevertheless, flood stages were the highest ever recorded and resulted from a significant loss of channel capacity due to channel narrowing that had occurred during the previous 18 years. Measurements from aerial photographs indicate that channel width had decreased between 35 and 50% between 1990 and 2008 during regional drought. During this period of low stream flow, invasion by non-native riparian vegetation (Tamarix spp., Arundo donax) helped trap sediment and promote floodplain accretion. Our resurveys of the channel indicate that the 2008 flood was a reset event and that the channel was re-widened by 32 to 48%. Repeated, oblique photographs showed significant channel migration and large scale floodplain stripping during this flood. These results show that although riparian vegetation may actively promote channel narrowing and floodplain accretion, moderately large floods may cause large scale bank erosion, floodplain stripping, and vegetation removal in alluvial valleys subject to large-scale invasion by nonnative plants.

  18. Identification and separation of DNA mixtures using peak area information

    DEFF Research Database (Denmark)

    Cowell, R.G.; Lauritzen, Steffen Lilholt; Mortera, J.

    , whose profiles have been measured, have contributed to the mixture, but also to predict DNA profiles of unknown contributors by separating the mixture into its individual components. The potential of our methodology is illustrated on case data examples and compared with alternative approaces......We show how probabilistic expert systems can be used to analyse forensic identification problems involving DNA mixture traces using quantitative peak area information. Peak area is modelled with conditional Gaussian distributions. The expert system can be used for scertaining whether individuals....... The advantages are that identification and separation issues can be handled in a unified way within a single network model and the uncertainty associated with the analysis is quantified....

  19. Structural and Optical Properties of Single Crystalline Bismuth Nanoparticles in Polymer

    Science.gov (United States)

    Kabir, Lutful; Mandal, Swapan K.

    We report here the structural and optical properties of Bi nanoparticles in polymer (polypyrrole) matrix. The nanoparticles are synthesized following a wet chemical route. The X-ray diffraction data clearly shows the growth of single crystalline Bi nanoparticles within the host polymer. The microstructure of the Bi nanoparticles obtained by transmission electron microscopy (TEM) reveals clearly the formation of spherical shaped nanoparticles of average size˜27 nm with a narrow size distribution. The optical absorption spectrum exhibits a distinct peak at 278 nm which is attributed to the surface plasmon band of Bi nanoparticles. The absorption spectrum is found to be described well following Mie theory.

  20. The PEAK experience in South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-11-01

    The PEAK Institute was developed to provide a linkage for formal (schoolteachers) and nonformal educators (extension agents) with agricultural scientists of Clemson University`s South Carolina Agricultural Experiment Station System. The goal of the Institute was to enable teams of educators and researchers to develop and provide PEAK science and math learning experiences related to relevant agricultural and environmental issues of local communities for both classroom and 4-H Club experiences. The Peak Institute was conducted through a twenty day residential Institute held in June for middle school and high school teachers who were teamed with an Extension agent from their community. These educators participated in hands-on, minds-on sessions conducted by agricultural researchers and Clemson University Cooperative Extension specialists. Participants were given the opportunity to see frontier science being conducted by scientists from a variety of agricultural laboratories.

  1. Detecting and accounting for multiple sources of positional variance in peak list registration analysis and spin system grouping.

    Science.gov (United States)

    Smelter, Andrey; Rouchka, Eric C; Moseley, Hunter N B

    2017-08-16

    Peak lists derived from nuclear magnetic resonance (NMR) spectra are commonly used as input data for a variety of computer assisted and automated analyses. These include automated protein resonance assignment and protein structure calculation software tools. Prior to these analyses, peak lists must be aligned to each other and sets of related peaks must be grouped based on common chemical shift dimensions. Even when programs can perform peak grouping, they require the user to provide uniform match tolerances or use default values. However, peak grouping is further complicated by multiple sources of variance in peak position limiting the effectiveness of grouping methods that utilize uniform match tolerances. In addition, no method currently exists for deriving peak positional variances from single peak lists for grouping peaks into spin systems, i.e. spin system grouping within a single peak list. Therefore, we developed a complementary pair of peak list registration analysis and spin system grouping algorithms designed to overcome these limitations. We have implemented these algorithms into an approach that can identify multiple dimension-specific positional variances that exist in a single peak list and group peaks from a single peak list into spin systems. The resulting software tools generate a variety of useful statistics on both a single peak list and pairwise peak list alignment, especially for quality assessment of peak list datasets. We used a range of low and high quality experimental solution NMR and solid-state NMR peak lists to assess performance of our registration analysis and grouping algorithms. Analyses show that an algorithm using a single iteration and uniform match tolerances approach is only able to recover from 50 to 80% of the spin systems due to the presence of multiple sources of variance. Our algorithm recovers additional spin systems by reevaluating match tolerances in multiple iterations. To facilitate evaluation of the

  2. Intrinsic advantages of packed capillaries over narrow-bore columns in very high-pressure gradient liquid chromatography.

    Science.gov (United States)

    Gritti, Fabrice; McDonald, Thomas; Gilar, Martin

    2016-06-17

    250μm×100mm fused silica glass capillaries were packed with 1.8μm high-strength silica (HSS) fully porous particles. They were prepared without bulky stainless steel endfittings and metal frits, which both generate significant sample dispersion. The isocratic efficiencies and gradient peak capacities of these prototype capillary columns were measured for small molecules (n-alkanophenones) using a home-made ultra-low dispersive micro-HPLC instrument. Their resolution power was compared to that of standard 2.1mm×100mm very high-pressure liquid chromatography (vHPLC) narrow-bore columns packed with the same particles. The results show that, for the same column efficiency (25000 plates) and gradient steepness (0.04min(-1)), the peak capacity of the 250μm i.d. capillary columns is systematically 15-20% higher than that of the 2.1mm i.d. narrow-bore columns. A validated model of gradient chromatography enabled one to predict accurately the observed peak capacities of the capillary columns for non-linear solvation strength retention behavior and under isothermal conditions. Thermodynamics applied to the eluent quantified the temperature difference for the thermal gradients in both capillary and narrow-bore columns. Experimental data revealed that the gradient peak capacity is more affected by viscous heating than the column efficiency. Unlike across 2.1mm i.d. columns, the changes in eluent composition across the 250μm i.d. columns during the gradient is rapidly relaxed by transverse dispersion. The combination of (1) the absence of viscous heating and (2) the high uniformity of the eluent composition across the diameter of capillary columns explains the intrinsic advantage of capillary over narrow-bore columns in gradient vHPLC.

  3. Search for Narrow Nucleon Resonance in $\\gamma p\\to \\eta p$

    CERN Document Server

    Anisovich, A V; Kuznetsov, V; Nikonov, V A; Polyakov, M V; Sarantsev, A V; Thoma, U

    2011-01-01

    Results of a partial wave analysis of new high-statistics data on $\\gamma p\\to p\\eta$ from MAMI are presented. A fit using known broad resonances and only standard background amplitudes can not describe the relatively narrow peaking structure in the cross section in the mass region of 1660-1750 MeV which follows a minimum. An improved description of the data can be reached by either assuming the existence of a narrow resonance at a mass of about 1700 MeV with small photo-coupling or by a threshold effect. In the latter case the observed structure is explained by a strong (resonant or non-resonant) $\\gamma p\\to\\omega p$ coupling in the $S_{11}$ partial wave. When the beam asymmetry data, published by part of the GRAAL collaboration, are included in the fit, the solution with a narrow $P_{11}$ state is slightly preferred. In that fit, mass and width of the hypothetical resonance are determined to $M\\sim$1694 MeV and $\\Gamma\\sim 40$ MeV, respectively, and the photo-coupling to $\\sqrt{{\\rm Br}_{\\eta N}} A_{1/2}^p...

  4. Single-Plane Magnetically Focused Elongated Small Field Proton Beams.

    Science.gov (United States)

    McAuley, Grant A; Slater, James M; Wroe, Andrew J

    2015-08-01

    We previously performed Monte Carlo simulations of magnetically focused proton beams shaped by a single quadrapole magnet and thereby created narrow elongated beams with superior dose delivery characteristics (compared to collimated beams) suitable for targets of similar geometry. The present study seeks to experimentally validate these simulations using a focusing magnet consisting of 24 segments of samarium cobalt permanent magnetic material adhered into a hollow cylinder. Proton beams with properties relevant to clinical radiosurgery applications were delivered through the magnet to a water tank containing a diode detector or radiochromic film. Dose profiles were analyzed and compared with analogous Monte Carlo simulations. The focused beams produced elongated beam spots with high elliptical symmetry, indicative of magnet quality. Experimental data showed good agreement with simulations, affirming the utility of Monte Carlo simulations as a tool to model the inherent complexity of a magnetic focusing system. Compared to target-matched unfocused simulations, focused beams showed larger peak to entrance ratios (26% to 38%) and focused simulations showed a two-fold increase in beam delivery efficiency. These advantages can be attributed to the magnetic acceleration of protons in the transverse plane that tends to counteract the particle outscatter that leads to degradation of peak to entrance performance in small field proton beams. Our results have important clinical implications and suggest rare earth focusing magnet assemblies are feasible and could reduce skin dose and beam number while delivering enhanced dose to narrow elongated targets (eg, in and around the spinal cord) in less time compared to collimated beams.

  5. Band Gap Narrowing and Widening of ZnO Nanostructures and Doped Materials

    OpenAIRE

    2015-01-01

    Band gap change in doped ZnO is an observed phenomenon that is very interesting from the fundamental point of view. This work is focused on the preparation of pure and single phase nanostructured ZnO and Cu as well as Mn-doped ZnO for the purpose of understanding the mechanisms of band gap narrowing in the materials. ZnO, Zn0.99Cu0.01O and Zn0.99Mn0.01O materials were prepared using a wet chemistry method, and X-ray diffraction (XRD) results showed that all samples were pure and single phase....

  6. Hydrogen in insulating oxide Y3Al5O12 strongly narrows the band gap

    Science.gov (United States)

    Winarski, D.; Persson, C.; Selim, F. A.

    2014-12-01

    We report an unusual band gap narrowing in Y3Al5O12 (YAG) insulating oxide after growing YAG single crystals in hydrogen atmosphere. Theory confirms that hydrogen interstitials as well as oxygen vacancies strongly shift the absorption spectrum towards lower energies. Furthermore, hydrogen eliminated all deep and shallow traps in the YAG structure and dramatically modified the optical and scintillation properties of YAG single crystals. We conclude that hydrogen plays a significant role in insulating oxides similar to its role in semiconductors and it may be used to passivate defects and improve exciton dynamics in oxides for optical and scintillation applications.

  7. Experimental Study on Convective Boiling Heat Transfer in Vertical Narrow Gap Annular Tube

    Institute of Scientific and Technical Information of China (English)

    Li Bin; He Anding; Wang Yueshe; Zhou Fangde

    2001-01-01

    Experiments are conducted to investigate the characteristics of single-phase forced-flow convection and boiling heat transfer of R113 flowing through annular tube with gap of 1, 1.5 and 2.5 mm, and also the visualization test are carried out to get two-phase flow regime. The data show that the Nusselt numbers for the narrow-gap are higher than those predicted by traditional large channel correlation and boiling heat transfer is enhanced. Based on the data obtained in this investigation, correlations for single-phase, forced convection and flow boiling in annular tube of different gap size has been developed.

  8. Some Phenomenological Aspects of the Peak Experience

    Science.gov (United States)

    Rosenblatt, Howard S.; Bartlett, Iris

    1976-01-01

    This article relates the psychological dynamics of "peak experiences" to two concepts, intentionality and paradoxical intention, within the philosophical orientation of phenomenology. A review of early philosophical theories of self (Kant and Hume) is presented and compared with the experiential emphasis found in the phenomenology of Husserl.…

  9. Some Phenomenological Aspects of the Peak Experience

    Science.gov (United States)

    Rosenblatt, Howard S.; Bartlett, Iris

    1976-01-01

    This article relates the psychological dynamics of "peak experiences" to two concepts, intentionality and paradoxical intention, within the philosophical orientation of phenomenology. A review of early philosophical theories of self (Kant and Hume) is presented and compared with the experiential emphasis found in the phenomenology of Husserl.…

  10. Real estate price peaks: a comparative overview

    CERN Document Server

    Röhner, B M

    2006-01-01

    First, we emphasize that the real estate price peaks which are currently under way in many industrialized countries (one important exception is Japan) share many of the characteristics of previous historical price peaks. In particular, we show that: (i) In the present episode real price increases are, at least for now, of the same order of magnitude as in previous episodes, typically of the order of 80 percent to 100 percent. (ii) Historically, price peaks turned out to be symmetrical with respect to the peak; soft landing, i.e. an upgoing phase followed by a plateau, has rarely (if ever) been observed. (iii) The inflated demand is mainly boosted by investors and high-income buyers. (iv) In the present as well as in previous episodes, the main engines in the upgoing phase have been the hot markets which developed in major cities such as London, Los Angeles, New York, Paris, San Francisco or Sydney. In our conclusion, we propose a prediction for real estate prices in the West of the United States over the peri...

  11. Spanish Peaks, Sangre de Cristo Range, Colorado

    Science.gov (United States)

    2002-01-01

    The Spanish Peaks, on the eastern flank of the Sangre de Cristo range, abruptly rise 7,000 feet above the western Great Plains. Settlers, treasure hunters, trappers, gold and silver miners have long sighted on these prominent landmarks along the Taos branch of the Santa Fe trail. Well before the westward migration, the mountains figured in the legends and history of the Ute, Apache, Comanche, and earlier tribes. 'Las Cumbres Espanolas' are also mentioned in chronicles of exploration by Spaniards including Ulibarri in 1706 and later by de Anza, who eventually founded San Francisco (California). This exceptional view (STS108-720-32), captured by the crew of Space Shuttle mission STS108, portrays the Spanish Peaks in the context of the southern Rocky Mountains. Uplift of the Sangre de Cristo began about 75 million years ago and produced the long north-trending ridges of faulted and folded rock to the west of the paired peaks. After uplift had ceased (26 to 22 million years ago), the large masses of igneous rock (granite, granodiorite, syenodiorite) that form the Peaks were emplaced (Penn, 1995-2001). East and West Spanish Peaks are 'stocks'-bodies of molten rock that intruded sedimentary layers, cooled and solidified, and were later exposed by erosion. East Peak (E), at 12,708 ft is almost circular and is about 5 1/2 miles long by 3 miles wide, while West Peak (W), at 13,623 ft is roughly 2 3/4 miles long by 1 3/4 miles wide. Great dikes-long stone walls-radiate outward from the mountains like spokes of a wheel, a prominent one forms a broad arc northeast of East Spanish Peak. As the molten rock rose, it forced its way into vertical cracks and joints in the sedimentary strata; the less resistant material was then eroded away, leaving walls of hard rock from 1 foot to 100 feet wide, up to 100 feet high, and as long as 14 miles. Dikes trending almost east-west are also common in the region. For more information visit: Sangres.com: The Spanish Peaks (accessed January 16

  12. Peaked and Smooth Solitons for K*(4,1 Equation

    Directory of Open Access Journals (Sweden)

    Yongan Xie

    2013-01-01

    Full Text Available This paper is contributed to explore all possible single peak solutions for the K*(4,1 equation ut=uxu2+2α(uuxxx+2uxuxx. Our procedure shows that the K*(4,1 equation either has peakon, cuspon, and smooth soliton solutions when sitting on a nonzero constant pedestal limξ→±∞u=A≠0 or possesses compacton solutions only when limξ→±∞u=A=0. We present a new smooth soliton solution in an explicit form. Mathematical analysis and numeric graphs are provided for those soliton solutions of the K*(4,1 equation.

  13. Double passing the Kitt Peak 1-m Fourier transform spectrometer

    Science.gov (United States)

    Jennings, D. E.; Hubbard, R.; Brault, J. W.

    1985-01-01

    Attention is given to a simple technique for performing the conversion of the Kitt Peak 1-m Fourier transform spectrometer's dual input/output optical configuration to a double pass configuration that improves spectral resolution by a factor of 2. The modification is made by placing a flat mirror in the output beam from each cat's eye, retroreflecting the beams back through the cat's eyes to the first beam splitter. A single detector is placed at the second input port, which then becomes the instrument's output.

  14. Narrowing of Terrace-width Distributions During Growth on Vicinals

    Science.gov (United States)

    Hamouda, Ajmi Bh.; Pimpinelli, A.; Einstein, T. L.

    2009-03-01

    Using kinetic Monte Carlo simulations for a generic minimal SOS model of vicinal surfaces, we compute the terrace-width distributions (TWDs) as a function of incident flux during homoepitaxial growth. We show that the distribution narrows markedly, U.B.P.-Clermont 2 as though there were a flux-dependent repulsion between steps, until the step picture fails at high flux. Using a Fokker-Planck approach, we analyze the evolution and saturation of this narrowing. We compare with a 1D model and with our simulations for narrowing due to an Ehrlich-Schwoebel barrier.

  15. Study of the narrow structure at 1685 MeV in γp→ηp

    Energy Technology Data Exchange (ETDEWEB)

    Anisovich, A.V. [Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg 188300 (Russian Federation); Helmholtz-Institut fur Strahlen- u. Kernphysik, Universität Bonn (Germany); Klempt, E. [Helmholtz-Institut fur Strahlen- u. Kernphysik, Universität Bonn (Germany); Kuznetsov, V. [Institute for Nuclear Research, 117312 Moscow (Russian Federation); Institut für Theoretische Physik II, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Nikonov, V.A. [Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg 188300 (Russian Federation); Helmholtz-Institut fur Strahlen- u. Kernphysik, Universität Bonn (Germany); Polyakov, M.V., E-mail: maxim.polyakov@tp2.rub.de [Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg 188300 (Russian Federation); Institut für Theoretische Physik II, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Sarantsev, A.V., E-mail: andsar@hiskp.uni-bonn.de [Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg 188300 (Russian Federation); Helmholtz-Institut fur Strahlen- u. Kernphysik, Universität Bonn (Germany); Thoma, U. [Helmholtz-Institut fur Strahlen- u. Kernphysik, Universität Bonn (Germany)

    2013-02-12

    Results of a coupled channel isobar analysis of new high-statistics data on γp→pη from MAMI are presented. A fit using known broad resonances and only standard background amplitudes cannot describe the relatively narrow peaking structure in the cross section in the mass region of 1660–1750 MeV which follows a minimum. An improved description of the data can be reached by either assuming the existence of a narrow resonance at a mass of about 1700 MeV with small photo-coupling or by a threshold effect. In the latter case the observed structure is explained by a strong (resonant or non-resonant) γp→ωp coupling in the S{sub 11} partial wave. When the beam asymmetry data, published by part of the GRAAL Collaboration, are included in the fit, the solution with a narrow P{sub 11} state is slightly preferred. In that fit, mass and width of the hypothetical resonance are determined to M∼1694 MeV and Γ∼40 MeV, respectively, and the photo-coupling to √(Br{sub ηN})A{sub 1/2}{sup p}∼2.6⋅10{sup −3} GeV{sup −1/2}. High-precision measurements of the target asymmetry and F-observable are mandatory to establish the possible existence of such a narrow state and to provide the necessary information to define which partial wave is responsible for the structure observed in the data.

  16. Predictors of the peak width for networks with exponential links

    Science.gov (United States)

    Troutman, B.M.; Karlinger, M.R.

    1989-01-01

    We investigate optimal predictors of the peak (S) and distance to peak (T) of the width function of drainage networks under the assumption that the networks are topologically random with independent and exponentially distributed link lengths. Analytical results are derived using the fact that, under these assumptions, the width function is a homogeneous Markov birth-death process. In particular, exact expressions are derived for the asymptotic conditional expectations of S and T given network magnitude N and given mainstream length H. In addition, a simulation study is performed to examine various predictors of S and T, including N, H, and basin morphometric properties; non-asymptotic conditional expectations and variances are estimated. The best single predictor of S is N, of T is H, and of the scaled peak (S divided by the area under the width function) is H. Finally, expressions tested on a set of drainage basins from the state of Wyoming perform reasonably well in predicting S and T despite probable violations of the original assumptions. ?? 1989 Springer-Verlag.

  17. Optimized aperiodic multilayer structures for use as narrow-angular absorbers

    Energy Technology Data Exchange (ETDEWEB)

    Granier, Christopher H., E-mail: cgrani1@lsu.edu; Dowling, Jonathan P. [Department of Physics and Astronomy, Hearne Institute of Theoretical Physics, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Afzal, Francis O. [Center for Computation and Technology, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Department of Physics, Truman State University, Kirksville, Missouri 63501,USA (United States); Lorenzo, Simón G. [Department of Physics and Astronomy, Hearne Institute of Theoretical Physics, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Center for Computation and Technology, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Reyes, Mario [Center for Computation and Technology, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Department of Physics, California State University, San Bernardino, California 92407 (United States); Department of Physics and Astronomy, Hearne Institute of Theoretical Physics, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Veronis, Georgios [Center for Computation and Technology, Louisiana State University, Baton Rouge, Louisiana 70803 (United States); School of Electrical Engineering and Computer Science, Louisiana State University, Baton Rouge, Louisiana 70803 (United States)

    2014-12-28

    In this paper, we investigate aperiodic multilayer structures for use as narrow-angular absorbers. The layer thicknesses and materials are optimized using a genetic global optimization algorithm coupled to a transfer matrix code to maximize the angular selectivity in the absorptance at a single or multiple wavelengths. We first consider structures composed of alternating layers of tungsten and silicon or silica, and find that it is not possible to achieve angular selectivity in the absorptance with such structures. We next consider structures composed of alternating layers of silicon and silica, and show that when optimized they exhibit high angular selectivity in absorptance. In addition, as the angular selectivity in absorptance increases, the wavelength range of high angular selectivity also decreases. Optimizing the material composition of the multilayer structures, in addition to optimizing the layer thicknesses, leads to marginal improvement in angular selectivity. Finally, we show that by optimizing the absorptance of the multilayer structures at multiple wavelengths, we can obtain structures exhibiting almost perfect absorptance at normal incidence and narrow angular width in absorptance at these wavelengths. Similar to the structures optimized at a single wavelength, the wavelength range of high angularly selective absorptance is narrow.

  18. Band Gap Narrowing and Widening of ZnO Nanostructures and Doped Materials.

    Science.gov (United States)

    Kamarulzaman, Norlida; Kasim, Muhd Firdaus; Rusdi, Roshidah

    2015-12-01

    Band gap change in doped ZnO is an observed phenomenon that is very interesting from the fundamental point of view. This work is focused on the preparation of pure and single phase nanostructured ZnO and Cu as well as Mn-doped ZnO for the purpose of understanding the mechanisms of band gap narrowing in the materials. ZnO, Zn0.99Cu0.01O and Zn0.99Mn0.01O materials were prepared using a wet chemistry method, and X-ray diffraction (XRD) results showed that all samples were pure and single phase. UV-visible spectroscopy showed that materials in the nanostructured state exhibit band gap widening with respect to their micron state while for the doped compounds exhibited band gap narrowing both in the nano and micron states with respect to the pure ZnO materials. The degree of band gap change was dependent on the doped elements and crystallite size. X-ray photoelectron spectroscopy (XPS) revealed that there were shifts in the valence bands. From both UV-visible and XPS spectroscopy, it was found that the mechanism for band gap narrowing was due to the shifting of the valance band maximum and conduction band minimum of the materials. The mechanisms were different for different samples depending on the type of dopant and dimensional length scales of the crystallites.

  19. Predicting VO2peak from Submaximal- and Peak Exercise Models: The HUNT 3 Fitness Study, Norway.

    Directory of Open Access Journals (Sweden)

    Henrik Loe

    Full Text Available Peak oxygen uptake (VO2peak is seldom assessed in health care settings although being inversely linked to cardiovascular risk and all-cause mortality. The aim of this study was to develop VO2peak prediction models for men and women based on directly measured VO2peak from a large healthy population.VO2peak prediction models based on submaximal- and peak performance treadmill work were derived from multiple regression analysis. 4637 healthy men and women aged 20-90 years were included. Data splitting was used to generate validation and cross-validation samples.The accuracy for the peak performance models were 10.5% (SEE = 4.63 mL⋅kg(-1⋅min(-1 and 11.5% (SEE = 4.11 mL⋅kg(-1⋅min(-1 for men and women, respectively, with 75% and 72% of the variance explained. For the submaximal performance models accuracy were 14.1% (SEE = 6.24 mL⋅kg(-1⋅min(-1 and 14.4% (SEE = 5.17 mL⋅kg(-1⋅min(-1 for men and women, respectively, with 55% and 56% of the variance explained. The validation and cross-validation samples displayed SEE and variance explained in agreement with the total sample. Cross-classification between measured and predicted VO2peak accurately classified 91% of the participants within the correct or nearest quintile of measured VO2peak.Judicious use of the exercise prediction models presented in this study offers valuable information in providing a fairly accurate assessment of VO2peak, which may be beneficial for risk stratification in health care settings.

  20. Effect of gear ratio on peak power and time to peak power in BMX cyclists.

    Science.gov (United States)

    Rylands, Lee P; Roberts, Simon J; Hurst, Howard T

    2017-03-01

    The aim of this study was to ascertain if gear ratio selection would have an effect on peak power and time to peak power production in elite Bicycle Motocross (BMX) cyclists. Eight male elite BMX riders volunteered for the study. Each rider performed three, 10-s maximal sprints on an Olympic standard indoor BMX track. The riders' bicycles were fitted with a portable SRM power meter. Each rider performed the three sprints using gear ratios of 41/16, 43/16 and 45/16 tooth. The results from the 41/16 and 45/16 gear ratios were compared to the current standard 43/16 gear ratio. Statistically, significant differences were found between the gear ratios for peak power (F(2,14) = 6.448; p = .010) and peak torque (F(2,14) = 4.777; p = .026), but no significant difference was found for time to peak power (F(2,14) = 0.200; p = .821). When comparing gear ratios, the results showed a 45/16 gear ratio elicited the highest peak power,1658 ± 221 W, compared to 1436 ± 129 W and 1380 ± 56 W, for the 43/16 and 41/16 ratios, respectively. The time to peak power showed a 41/16 tooth gear ratio attained peak power in -0.01 s and a 45/16 in 0.22 s compared to the 43/16. The findings of this study suggest that gear ratio choice has a significant effect on peak power production, though time to peak power output is not significantly affected. Therefore, selecting a higher gear ratio results in riders attaining higher power outputs without reducing their start time.

  1. Integrating narrow therapeutic index drug formulations in transplantation

    NARCIS (Netherlands)

    A. Johnston (Andrew); L. Schick (Liz); T. van Gelder (Teun)

    2012-01-01

    textabstractThere is considerable debate regarding generic drug substitution in solid organ transplant recipients, and various European transplant associations and societies have expressed caution about the potential adverse consequences from uncontrolled switching between the different narrow

  2. A Compact Narrow-Band Tunable Optical Transversal Filter

    Institute of Scientific and Technical Information of China (English)

    Zhigang Wu; Katsuyuki Utaka

    2003-01-01

    We present a compact narrow-band tunable optical transversal filter with phase-variable taps. A transmission bandwidth of the comb filter is less than 0.2nm and can be continuously tuned in the entire FSR.

  3. Comment on the narrow structure reported by Amaryan et al

    CERN Document Server

    Anghinolfi, M; Baltzell, N A; Battaglieri, M; Bedlinskiy, I; Bellis, M; Biselli, A S; Bookwalter, C; Boiarinov, S; Bosted, P; Burkert, V D; Carman, D S; Celentano, A; Chandavar, S; Cole, P L; Crede, V; De Vita, R; De Sanctis, E; Dey, B; Dickson, R; Doughty, D; Dugger, M; Dupre, R; Egiyan, H; Alaoui, A El; Fassi, L El; Elouadrhiri, L; Eugenio, P; Fedotov, G; Gabrielyan, M Y; Garcon, M; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Goetz, J T; Golovatch, E; Guidal, M; Guo, L; Hafidi, K; Hakobyan, H; Heddle, D; Hicks, K; Holtrop, M; Ireland, D G; Ishkhanov, B S; Isupov, E L; Jo, H S; Joo, K; Khetarpal, P; Kim, A; Kim, W; Kubarovsky, V; Kuleshov, S V; Lu, H Y; MacGregor, L J D; Markov, N; McCracken, M E; McKinnon, B; Mestayer, M D; Meyer, C A; Mirazita, M; Mokeev, V; Moriya, K; Morrison, B; Ni, A; Niccolai, S; Niculescu, G; Niculescu, I; Osipenko, M; Ostrovidov, A I; Park, K; Park, S; Pereira, S Anefalos; Pisano, S; Pogorelko, O; Pozdniakov, S; Price, J W; Ricco, G; Ripani, M; Ritchie, B G; Rossi, P; Schott, D; Schumacher, R A; Seder, E; Sharabian, Y G; Smith, E S; Sober, D I; Stepanyan, S S; Stoler, P; Tang, W; Ungaro, M; Vernarsky, B; Vineyard, M F; Weygand, D P; Wood, M H; Zachariou, N; Zhao, B

    2012-01-01

    The CLAS Collaboration provides a comment on the physics interpretation of the results presented in a paper published by M. Amaryan et al. regarding the possible observation of a narrow structure in the mass spectrum of a photoproduction experiment.

  4. Novel bioequivalence approach for narrow therapeutic index drugs.

    Science.gov (United States)

    Yu, L X; Jiang, W; Zhang, X; Lionberger, R; Makhlouf, F; Schuirmann, D J; Muldowney, L; Chen, M-L; Davit, B; Conner, D; Woodcock, J

    2015-03-01

    Narrow therapeutic index drugs are defined as those drugs where small differences in dose or blood concentration may lead to serious therapeutic failures and/or adverse drug reactions that are life-threatening or result in persistent or significant disability or incapacity. The US Food and Drug Administration proposes that the bioequivalence of narrow therapeutic index drugs be determined using a scaling approach with a four-way, fully replicated, crossover design study in healthy subjects that permits the simultaneous equivalence comparison of the mean and within-subject variability of the test and reference products. The proposed bioequivalence limits for narrow therapeutic index drugs of 90.00%-111.11% would be scaled based on the within-subject variability of the reference product. The proposed study design and data analysis should provide greater assurance of therapeutic equivalence of narrow therapeutic index drug products.

  5. The Doppler peaks from a generic defect

    CERN Document Server

    Magueijo, J

    1996-01-01

    We investigate which of the exotic Doppler peak features found for textures and cosmic strings are generic novelties pertaining to defects. We find that the ``out of phase'' texture signature is an accident. Generic defects, when they generate a secondary peak structure similar to inflation, apply to it an additive shift. It is not necessary for this shift to be ``out of phase''. We also show which factors are responsible for the absence of secondary oscillations found for cosmic strings. Within this general analysis we finally consider the conditions under which topological defects and inflation can be confused. It is argued that only \\Omega=1 inflation and a defect with a horizon size coherence length have a chance to be confused. Any other inflationary or defect model always differ distinctly. (To appear in the proceedings of the XXXIth Moriond meeting, ``Microwave Background Anisotropies'')

  6. Solar Cycle 24: is the peak coming?

    CERN Document Server

    Sello, Stefano

    2012-01-01

    Solar cycle activity forecasting, mainly its magnitude and timing, is an essential issue for numerous scientific and technological applications: in fact, during an active solar period, many strong eruptions occur on the Sun with increasing frequency, such as flares, coronal mass ejections, high velocity solar wind photons and particles, which can severely affect the Earth's ionosphere and the geomagnetic field, with impacts on the low atmosphere. Thus it is very important to develop reliable solar cycle prediction methods for the incoming solar activity. The current solar cycle 24 appeared unusual from many points of view: an unusually extended minimum period, and a global low activity compared to those of the previous three or four cycles. Currently, there are many different evidences that the peak in the northern hemisphere already occurred at 2011.6 but not yet in the southern hemisphere. In this brief note we update the peak prediction and its timing, based on the most recent observations.

  7. Peak oil, food systems, and public health.

    Science.gov (United States)

    Neff, Roni A; Parker, Cindy L; Kirschenmann, Frederick L; Tinch, Jennifer; Lawrence, Robert S

    2011-09-01

    Peak oil is the phenomenon whereby global oil supplies will peak, then decline, with extraction growing increasingly costly. Today's globalized industrial food system depends on oil for fueling farm machinery, producing pesticides, and transporting goods. Biofuels production links oil prices to food prices. We examined food system vulnerability to rising oil prices and the public health consequences. In the short term, high food prices harm food security and equity. Over time, high prices will force the entire food system to adapt. Strong preparation and advance investment may mitigate the extent of dislocation and hunger. Certain social and policy changes could smooth adaptation; public health has an essential role in promoting a proactive, smart, and equitable transition that increases resilience and enables adequate food for all.

  8. Excursion set peaks: the role of shear

    CERN Document Server

    Castorina, Emanuele; Hahn, Oliver; Sheth, Ravi K

    2016-01-01

    Recent analytical work on the modelling of dark halo abundances and clustering has demonstrated the advantages of combining the excursion set approach with peaks theory. We extend these ideas and introduce a model of excursion set peaks that incorporates the role of initial tidal effects or shear in determining the gravitational collapse of dark haloes. The model -- in which the critical density threshold for collapse depends on the tidal influences acting on protohaloes -- is well motivated from ellipsoidal collapse arguments and is also simple enough to be analytically tractable. We show that the predictions of this model are in very good agreement with measurements of the halo mass function and traditional scale dependent halo bias in N-body simulations across a wide range of masses and redshift. The presence of shear in the collapse threshold means that halo bias is naturally predicted to be nonlocal, and that protohalo densities at fixed mass are naturally predicted to have Lognormal-like distributions. ...

  9. WISE J233237.05-505643.5: A Double-Peaked Broad-Lined AGN with Spiral-Shaped Radio Morphology

    Science.gov (United States)

    Tsai, Chao Wei; Jarrett, Thomas H.; Stern, Daniel; Emonts, Bjorn; Barrows, R. Scott; Assef, Roberto J.; Norris, Ray P.; Eisenhardt, Peter R. M.; Lonsdale, Carol; Blain, Andrew W.; Benford, Dominic J.; Wu, Jingwen; Stalder, Brian; Stubbs, Christopher W.; High, F. William; Li, K. L.; Kong, Albert K. H.

    2013-01-01

    We present radio continuum mapping, optical imaging and spectroscopy of the newly discovered double-peaked broad-lined AGN WISE J233237.05-505643.5 at redshift z = 0.3447. This source exhibits an FR-I and FR-II hybrid-morphology, characterized by bright core, jet, and Doppler-boosted lobe structures in ATCA continuum maps at 1.5, 5.6, and 9 GHz. Unlike most FR-II objects, W2332-5056 is hosted by a disk-like galaxy. The core has a projected 5" linear radio feature that is perpendicular to the curved primary jet, hinting at unusual and complex activity within the inner 25 kpc. The multi-epoch optical-near-IR photometric measurements indicate significant variability over a 3-20 year baseline from the AGN component. Gemini-South optical data shows an unusual double-peaked emission-line features: the centroids of the broad-lined components of H-alpha and H-beta are blueshifted with respect to the narrow lines and host galaxy by approximately 3800 km/s. We examine possible cases which involve single or double supermassive black holes in the system, and discuss required future investigations to disentangle the mystery nature of this system.

  10. WISE J233237.05–505643.5: A double-peaked, broad-lined active galactic nucleus with a spiral-shaped radio morphology

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Chao-Wei [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Jarrett, T. H. [Astronomy Department, University of Cape Town, Private Bag X3, Rondebosch 7701 (South Africa); Stern, Daniel; Assef, Roberto J.; Eisenhardt, Peter R. M.; Wu, Jingwen [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109 (United States); Emonts, Bjorn [Centro de Astrobiología (INTA-CSIC), Ctra de Torrejón a Ajalvir, km 4, E-28850 Torrejón de Ardoz, Madrid (Spain); Barrows, R. Scott [Arkansas Center for Space and Planetary Sciences, University of Arkansas, Fayetteville, AR 72701 (United States); Norris, Ray P. [Australia Telescope National Facility, CSIRO Astronomy and Space Science, P.O. Box 76, Epping NSW 1710 (Australia); Lonsdale, Carol [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903 (United States); Blain, Andrew W. [Department of Physics and Astronomy, University of Leicester, 1 University Road, Leicester LE1 7RH (United Kingdom); Benford, Dominic J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Stalder, Brian; Stubbs, Christopher W. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); High, F. William [Kavli Institute for Cosmological Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States); Li, K. L.; Kong, Albert K. H., E-mail: Chao-Wei.Tsai@jpl.nasa.gov [Institute of Astronomy and Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

    2013-12-10

    We present radio continuum mapping, optical imaging, and spectroscopy of the newly discovered double-peaked, broad-lined active galactic nucleus (AGN) WISE J233237.05–505643.5 at redshift z = 0.3447. This source exhibits an FR-I and FR-II hybrid morphology, characterized by a bright core, jet, and Doppler-boosted lobe structures in Australian Telescope Compact Array continuum maps at 1.5, 5.6, and 9 GHz. Unlike most FR-II objects, W2332–5056 is hosted by a disk-like galaxy. The core has a projected 5'' linear radio feature that is perpendicular to the curved primary jet, hinting at unusual and complex activity within the inner 25 kpc. The multi-epoch, optical-near-IR photometric measurements indicate significant variability over a 3-20 yr baseline from the AGN component. Gemini South optical data show unusual double-peaked emission-line features: the centroids of the broad-lined components of Hα and Hβ are blueshifted with respect to the narrow lines and host galaxy by ∼3800 km s{sup –1}. We examine possible cases that involve single or double supermassive black holes in the system and discuss the required future investigations to disentangle the mysterious nature of this system.

  11. WISE J233237.05-505643.5: a Double-Peaked Broad-Lined AGN with Spiral-Shaped Radio Morphology

    CERN Document Server

    Tsai, Chao-Wei; Stern, Daniel; Bjorn, Emonts; Barrows, R Scott; Assef, Roberto J; Norris, Ray P; Eisenhardt, Peter R M; Lonsdale, Carol J; Blain, Andrew W; Benford, Dominic J; Wu, Jingwen; Stalder, Brian; Stubbs, Christopher W; High, F William; Li, K L; Kong, Albert K H

    2013-01-01

    We present radio continuum mapping, optical imaging and spectroscopy of the newly discovered double-peaked broad-lined AGN WISE J233237.05-505643.5 at redshift z = 0.3447. This source exhibits an FR-I and FR-II hybrid-morphology, characterized by bright core, jet, and Doppler-boosted lobe structures in ATCA continuum maps at 1.5, 5.6, and 9 GHz. Unlike most FR-II objects, W2332-5056 is hosted by a disk-like galaxy. The core has a projected 5" linear radio feature that is perpendicular to the curved primary jet, hinting at unusual and complex activity within the inner 25 kpc. The multi-epoch optical-near-IR photometric measurements indicate significant variability over a 3-20 year baseline from the AGN component. Gemini-South optical data shows an unusual double-peaked emission-line features: the centroids of the broad-lined components of H-alpha and H-beta are blueshifted with respect to the narrow lines and host galaxy by ~ 3800 km/s. We examine possible cases which involve single or double supermassive blac...

  12. Reducing Peak Power in Automated Weapon Laying

    Science.gov (United States)

    2016-02-01

    The values used are determined based on a number of factors including available power, maximum motor speed , maximum safe slewing speeds , peak...METHODS, ASSUMPTIONS, AND PROCEDURES Conventions and Variable Definitions Before describing the formulas to solve the aforementioned problems, it is...These two formulas are set equal to each other in equation 9 and then solved for t2 in equation 10. Note that the negative value of α2 results in a

  13. Hanford Site peak gust wind speeds

    Energy Technology Data Exchange (ETDEWEB)

    Ramsdell, J.V.

    1998-09-29

    Peak gust wind data collected at the Hanford Site since 1945 are analyzed to estimate maximum wind speeds for use in structural design. The results are compared with design wind speeds proposed for the Hanford Site. These comparisons indicate that design wind speeds contained in a January 1998 advisory changing DOE-STD-1020-94 are excessive for the Hanford Site and that the design wind speeds in effect prior to the changes are still appropriate for the Hanford Site.

  14. STUDY OF HYDRODYNAMIC FORCES OF SHIPS IN NARROW WATERWAY

    Institute of Scientific and Technical Information of China (English)

    Zhang Xie-dong; Wu Xiu-heng

    2003-01-01

    The collision of ships in narrow waterway may occur for a variety of reasons. The hydrodynamic forces between two ships change the maneuvering characteristics of ships greatly. So based on the boundary element method, this paper proposes a calculation method for hydrodynamic interaction forces between ships under meeting and passing conditions in narrow waterway. The results from this method are compared with the existing results obtained from other theoretical approaches, and they are in good agreement.

  15. METing SUSY on the Z peak

    Energy Technology Data Exchange (ETDEWEB)

    Barenboim, G.; Bernabeu, J.; Vives, O. [Universitat de Valencia, Departament de Fisica Teorica, Burjassot (Spain); Universitat de Valencia-CSIC, Parc Cientific U.V., IFIC, Paterna (Spain); Mitsou, V.A.; Romero, E. [Universitat de Valencia-CSIC, Parc Cientific U.V., IFIC, Paterna (Spain)

    2016-02-15

    Recently the ATLAS experiment announced a 3 σ excess at the Z-peak consisting of 29 pairs of leptons together with two or more jets, E{sub T}{sup miss} > 225 GeV and HT > 600 GeV, to be compared with 10.6 ± 3.2 expected lepton pairs in the Standard Model. No excess outside the Z-peak was observed. By trying to explain this signal with SUSY we find that only relatively light gluinos, m{sub g} or similar 400 GeV decaying predominantly to Z-boson plus a light gravitino, such that nearly every gluino produces at least one Z-boson in its decay chain, could reproduce the excess. We construct an explicit general gauge mediation model able to reproduce the observed signal overcoming all the experimental limits. Needless to say, more sophisticated models could also reproduce the signal, however, any model would have to exhibit the following features: light gluinos, or heavy particles with a strong production cross section, producing at least one Z-boson in its decay chain. The implications of our findings for the Run II at LHC with the scaling on the Z peak, as well as for the direct search of gluinos and other SUSY particles, are pointed out. (orig.)

  16. Ionoacoustic characterization of the proton Bragg peak with submillimeter accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Assmann, W., E-mail: walter.assmann@lmu.de; Reinhardt, S.; Lehrack, S.; Edlich, A.; Thirolf, P. G.; Parodi, K. [Department for Medical Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, Garching 85748 (Germany); Kellnberger, S.; Omar, M.; Ntziachristos, V. [Institute for Biological and Medical Imaging, Technische Universität München and Helmholtz Zentrum München, Ingolstädter Landstrasse 1, Neuherberg 85764 (Germany); Moser, M.; Dollinger, G. [Institute for Applied Physics and Measurement Technology, Universität der Bundeswehr, Werner-Heisenberg-Weg 39, Neubiberg 85577 (Germany)

    2015-02-15

    Purpose: Range verification in ion beam therapy relies to date on nuclear imaging techniques which require complex and costly detector systems. A different approach is the detection of thermoacoustic signals that are generated due to localized energy loss of ion beams in tissue (ionoacoustics). Aim of this work was to study experimentally the achievable position resolution of ionoacoustics under idealized conditions using high frequency ultrasonic transducers and a specifically selected probing beam. Methods: A water phantom was irradiated by a pulsed 20 MeV proton beam with varying pulse intensity and length. The acoustic signal of single proton pulses was measured by different PZT-based ultrasound detectors (3.5 and 10 MHz central frequencies). The proton dose distribution in water was calculated by Geant4 and used as input for simulation of the generated acoustic wave by the matlab toolbox k-WAVE. Results: In measurements from this study, a clear signal of the Bragg peak was observed for an energy deposition as low as 10{sup 12} eV. The signal amplitude showed a linear increase with particle number per pulse and thus, dose. Bragg peak position measurements were reproducible within ±30 μm and agreed with Geant4 simulations to better than 100 μm. The ionoacoustic signal pattern allowed for a detailed analysis of the Bragg peak and could be well reproduced by k-WAVE simulations. Conclusions: The authors have studied the ionoacoustic signal of the Bragg peak in experiments using a 20 MeV proton beam with its correspondingly localized energy deposition, demonstrating submillimeter position resolution and providing a deep insight in the correlation between the acoustic signal and Bragg peak shape. These results, together with earlier experiments and new simulations (including the results in this study) at higher energies, suggest ionoacoustics as a technique for range verification in particle therapy at locations, where the tumor can be localized by ultrasound

  17. Saccadic peak velocity and EEG as end-points for a serotonergic challenge test.

    NARCIS (Netherlands)

    Gijsman, H.J.; Gerven, J.M.A. van; Verkes, R.J.; Schoemaker, R.C.; Pieters, M.; Pennings, E.J.; Hessing, T.J.; Cohen, A.

    2002-01-01

    We previously reported that a single dose of the serotonin receptor agonist meta-chlorophenylpiperazine increased the peak velocity of saccadic eye movements and decreased low-frequency electroencephalographic activity. METHODS: We administered a single dose of the serotonin releaser dexfenfluramine

  18. Will peak oil accelerate carbon dioxide emissions?

    Science.gov (United States)

    Caldeira, K.; Davis, S. J.; Cao, L.

    2008-12-01

    The relative scarcity of oil suggests that oil production is peaking and will decline thereafter. Some have suggested that this represents an opportunity to reduce carbon dioxide emissions. However, in the absence of constraints on carbon dioxide emission, "peak oil" may drive a shift towards increased reliance on coal as a primary energy source. Because coal per unit energy, in the absence of carbon capture and disposal, releases more carbon dioxide to the atmosphere than oil, "peak oil" may lead to an acceleration of carbon dioxide emissions. We will never run out of oil. As oil becomes increasingly scarce, prices will rise and therefore consumption will diminish. As prices rise, other primary energy sources will become increasingly competitive with oil. The developed world uses oil primarily as a source of transportation fuels. The developing world uses oil primarily for heat and power, but the trend is towards increasing reliance on oil for transportation. Liquid fuels, including petroleum derivatives such as gasoline and diesel fuel, are attractive as transportation fuels because of their relative abundance of energy per unit mass and volume. Such considerations are especially important for the air transport industry. Today, there is little that can compete with petroleum-derived transportation fuels. Future CO2 emissions from the transportation sector largely depend on what replaces oil as a source of fuel. Some have suggested that biomass-derived ethanol, hydrogen, or electricity could play this role. Each of these potential substitutes has its own drawbacks (e.g., low power density per unit area in the case of biomass, low power density per unit volume in the case of hydrogen, and low power density per unit mass in the case of battery storage). Thus, it is entirely likely that liquefaction of coal could become the primary means by which transportation fuels are produced. Since the burning of coal produces more CO2 per unit energy than does the burning of

  19. Effect of Rainfall on Traffic Stream Characteristics during Peak and Non-Peak Periods

    Directory of Open Access Journals (Sweden)

    Hashim Mohammed Alhassan

    2012-01-01

    Full Text Available This paper examined the effect of rainfall on traffic stream behaviour during  peak and non-peak periods on a basic highway section. Data on this section which is located on the J5 was collected for four months during which 99 rainfall events occurred. The traffic consisted of 75.80% cars, 10.23% motorcycles, 3.51% trucks and 10.46%  of other vehicles. Traffic was observed for both rain and no-rain conditions and the data was analysed to see the effect of the rain. The results showed decreases in the speed as the rain intensity increased. Similarly, the traffic flow rates decreased as the rain intensity increased. This trend was observed for both peak and non-peak periods and for both directions. It is concluded that the effect of rain during peak period could have more serious consequences on the traffic flow than during non-peak periods because of the higher flow rates and the constrained nature of the flow. Consequently, capacity degradations up to 30% during peak periods would require resources to be employed to manage the traffic.

  20. Sharpening of the 6.8 nm peak in an Nd:YAG laser produced Gd plasma by using a pre-formed plasma

    Directory of Open Access Journals (Sweden)

    Yong Tian

    2016-03-01

    Full Text Available For effective use of a laser-produced-plasma (LPP light source, an LPP is desired to emit a narrow spectral peak because the reflection spectrum of multilayer mirrors for guiding emission from the source is very narrow. While a Gd plasma has been studied extensively as an extreme ultraviolet (EUV light source at around 6.8 nm, where La/B4C multilayer is reported to have a high reflectivity with a bandwidth of about 0.6 %, all previous works using an Nd:YAG laser reported very broad spectra. This paper reports the first narrowing of the 6.8 nm peak in the case of using an Nd:YAG laser to generate a Gd plasma by using a pre-pulse. The best peak narrowing is observed when a pre-formed plasma is heated by a 1064 nm main laser pulse with a duration of 10 ns at the irradiation density of 4x 1011 W/cm2 at a delay time of 50 ns after the pre-pulse irradiation. The observed spectral width of about 0.3 nm is about one fifth of the value for no pre-formed plasma. The peak wavelength of the 6.8 nm band shifted to a longer wavelength side and the peak was broadened both for lower and higher laser irradiation density. It is discussed that this robustness of the peak position of the 6.8 nm Gd peak against temperature change is suitable to achieve a narrow bandwidth from an LPP generated on solid. The observed spectra are compared with those previously reported in various conditions.

  1. The Quasar SDSS J105041.35+345631.3: Black Hole Recoil or Extreme Double-Peaked Emitter?

    CERN Document Server

    Shields, G A; Smith, K L; Bonning, E W; Salviander, S; Singh-Kalirai, J; Strickler, R; Ramirez-Ruiz, E; Dutton, A A; Treu, T; Marshall, P J

    2009-01-01

    The quasar SDSS J105041.35+345631.3 (z = 0.272) has broad emission lines blueshifted by 3500 km/s relative to the narrow lines and the host galaxy. Such an object may be a candidate for a recoiling supermassive black hole, a binary black hole, a superposition of two objects, or an unusual geometry for the broad emission-line region (BLR). The absence of narrow lines at the broad line redshift argues against superposition. New Keck spectra of J1050+3456 place tight constraints on the binary model. The combination of large velocity shift and symmetrical H-beta profile, as well as aspects of the narrow line spectrum, make J1050+3456 an interesting candidate for black hole recoil. Other aspects of the spectrum suggest an extreme case of a double-peaked emitter. We discuss possible observational tests to determine the true nature of this exceptional object.

  2. Electromechanical Peak Devices of Distributed Power Generation

    Directory of Open Access Journals (Sweden)

    S. V. Konstantinova

    2011-01-01

    Full Text Available The power world crises (1973, 1979 have demonstrated that mankind entered the expensive energy epoch. More and more attitude is given to power saving problem by including renewable power sources in energy balance of the countries. The paper analyzes a power system inBelarusand a typical chart of the active load is cited in the paper. Equalization of load chart is considered as one of measures directed on provision of higher operational efficiency of power system and power saving.  This purpose can be obtained while including electromechanical peak devices of the distributed generation in the energy balance.

  3. LARAMIE PEAK WILDERNESS STUDY AREA, WYOMING.

    Science.gov (United States)

    Segerstrom, Kenneth; Weisner, R.C.

    1984-01-01

    On the basis of a mineral survey, most of the Laramie Peak Wilderness study area in Wyoming was concluded to have little promise for the occurrence of mineral or energy resources. Only three small areas in the northern part, one extending outside the study area to Esterbrook, were found to have probable mineral-resource potential for copper and lead. The geologic setting precludes the presence of fossil-fuel resources in the study area. There are no surface indications that geothermal energy could be developed within or near the study area.

  4. Forecasting peaks of seasonal influenza epidemics.

    Science.gov (United States)

    Nsoesie, Elaine; Mararthe, Madhav; Brownstein, John

    2013-06-21

    We present a framework for near real-time forecast of influenza epidemics using a simulation optimization approach. The method combines an individual-based model and a simple root finding optimization method for parameter estimation and forecasting. In this study, retrospective forecasts were generated for seasonal influenza epidemics using web-based estimates of influenza activity from Google Flu Trends for 2004-2005, 2007-2008 and 2012-2013 flu seasons. In some cases, the peak could be forecasted 5-6 weeks ahead. This study adds to existing resources for influenza forecasting and the proposed method can be used in conjunction with other approaches in an ensemble framework.

  5. Peak oil, economic growth, and wildlife conservation

    CERN Document Server

    Gates, J Edward; Czech, Brian

    2014-01-01

    The proposed book focuses on one of the most important issues affecting humankind in this century - Peak Oil or the declining availability of abundant, cheap energy-and its effects on our industrialized economy and wildlife conservation. Energy will be one of the defining issues of the 21st Century directly affecting wildlife conservation wherever energy extraction is a primary economic activity and indirectly through deepening economic recessions. Since cheap, abundant energy has been at the core of our industrial society, and has resulted in the technological advancements we enjoy today, the

  6. Particle creation by peak electric field

    CERN Document Server

    Adorno, T C; Gitman, D M

    2016-01-01

    The particle creation by the so-called peak electric field is considered. The latter field is a combination of two exponential parts, one exponentially-increasing and another exponentially-decreasing. We find exact solutions of the Dirac equation with the field under consideration with appropriate asymptotic conditions and calculate all the characteristics of particle creation effect, in particular, differential mean numbers of created particle, total number of created particles, and the probability for a vacuum to remain a vacuum. Characteristic asymptotic regimes are discussed in detail and a comparison with the pure asymptotically decaying field is considered.

  7. Particle creation by peak electric field

    Energy Technology Data Exchange (ETDEWEB)

    Adorno, T.C. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); Gavrilov, S.P. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); Herzen State Pedagogical University of Russia, Department of General and Experimental Physics, St. Petersburg (Russian Federation); Gitman, D.M. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); P. N. Lebedev Physical Institute, Moscow (Russian Federation); University of Sao Paulo, Institute of Physics, CP 66318, Sao Paulo, SP (Brazil)

    2016-08-15

    The particle creation by the so-called peak electric field is considered. The latter field is a combination of two exponential parts, one exponentially increasing and another exponentially decreasing. We find exact solutions of the Dirac equation with the field under consideration with appropriate asymptotic conditions and calculate all the characteristics of particle creation effect, in particular, differential mean numbers of created particle, total number of created particles, and the probability for a vacuum to remain a vacuum. Characteristic asymptotic regimes are discussed in detail and a comparison with the pure asymptotically decaying field is considered. (orig.)

  8. Beyond the Peak - Tactile Temporal Discrimination Does Not Correlate with Individual Peak Frequencies in Somatosensory Cortex.

    Science.gov (United States)

    Baumgarten, Thomas J; Schnitzler, Alfons; Lange, Joachim

    2017-01-01

    The human sensory systems constantly receive input from different stimuli. Whether these stimuli are integrated into a coherent percept or segregated and perceived as separate events, is critically determined by the temporal distance of the stimuli. This temporal distance has prompted the concept of temporal integration windows or perceptual cycles. Although this concept has gained considerable support, the neuronal correlates are still discussed. Studies suggested that neuronal oscillations might provide a neuronal basis for such perceptual cycles, i.e., the cycle lengths of alpha oscillations in visual cortex and beta oscillations in somatosensory cortex might determine the length of perceptual cycles. Specifically, recent studies reported that the peak frequency (the frequency with the highest spectral power) of alpha oscillations in visual cortex correlates with subjects' ability to discriminate two visual stimuli. In the present study, we investigated whether peak frequencies in somatosensory cortex might serve as the correlate of perceptual cycles in tactile discrimination. Despite several different approaches, we were unable to find a significant correlation between individual peak frequencies in the alpha- and beta-band and individual discrimination abilities. In addition, analysis of Bayes factor provided evidence that peak frequencies and discrimination thresholds are unrelated. The results suggest that perceptual cycles in the somatosensory domain are not necessarily to be found in the peak frequency, but in other frequencies. We argue that studies based solely on analysis of peak frequencies might thus miss relevant information.

  9. PeakVizor: Visual Analytics of Peaks in Video Clickstreams from Massive Open Online Courses.

    Science.gov (United States)

    Chen, Qing; Chen, Yuanzhe; Liu, Dongyu; Shi, Conglei; Wu, Yingcai; Qu, Huamin

    2016-10-01

    Massive open online courses (MOOCs) aim to facilitate open-access and massive-participation education. These courses have attracted millions of learners recently. At present, most MOOC platforms record the web log data of learner interactions with course videos. Such large amounts of multivariate data pose a new challenge in terms of analyzing online learning behaviors. Previous studies have mainly focused on the aggregate behaviors of learners from a summative view; however, few attempts have been made to conduct a detailed analysis of such behaviors. To determine complex learning patterns in MOOC video interactions, this paper introduces a comprehensive visualization system called PeakVizor. This system enables course instructors and education experts to analyze the "peaks" or the video segments that generate numerous clickstreams. The system features three views at different levels: the overview with glyphs to display valuable statistics regarding the peaks detected; the flow view to present spatio-temporal information regarding the peaks; and the correlation view to show the correlation between different learner groups and the peaks. Case studies and interviews conducted with domain experts have demonstrated the usefulness and effectiveness of PeakVizor, and new findings about learning behaviors in MOOC platforms have been reported.

  10. A template-free approach for determining the latency of single events of auditory evoked M100

    Energy Technology Data Exchange (ETDEWEB)

    Burghoff, M [Physikalisch-Technische Bundesanstalt (PTB), Berlin (Germany); Link, A [Physikalisch-Technische Bundesanstalt (PTB), Berlin (Germany); Salajegheh, A [Cognitive Neuroscience of Language Laboratory, University of Maryland College Park, MD (United States); Elster, C [Physikalisch-Technische Bundesanstalt (PTB), Berlin (Germany); Poeppel, D [Cognitive Neuroscience of Language Laboratory, University of Maryland College Park, MD (United States); Trahms, L [Physikalisch-Technische Bundesanstalt (PTB), Berlin (Germany)

    2005-02-07

    The phase of the complex output of a narrow band Gaussian filter is taken to define the latency of the auditory evoked response M100 recorded by magnetoencephalography. It is demonstrated that this definition is consistent with the conventional peak latency. Moreover, it provides a tool for reducing the number of averages needed for a reliable estimation of the latency. Single-event latencies obtained by this procedure can be used to improve the signal quality of the conventional average by latency adjusted averaging. (note)

  11. Uniqueness plots: A simple graphical tool for identifying poor peak fits in X-ray photoelectron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Bhupinder; Diwan, Anubhav; Jain, Varun [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, 84606 (United States); Herrera-Gomez, Alberto [CINVESTAV-Unidad Queretaro, Queretaro, 76230 (Mexico); Terry, Jeff [Department of Physics, Illinois Institute of Technology, Chicago, IL, 60616 (United States); Linford, Matthew R., E-mail: mrlinford@chem.byu.edu [Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT, 84606 (United States)

    2016-11-30

    Highlights: • Uniqueness plots are introduced as a new tool for identifying poor XPS peak fits. • Uniqueness plots are demonstrated on real XPS data sets. • A horizontal line in a uniqueness plot indicates a poor fit, i.e., fit parameter correlation. • A parabolic shape in a uniqueness plot indicates that a fit may be appropriate. - Abstract: Peak fitting is an essential part of X-ray photoelectron spectroscopy (XPS) narrow scan analysis, and the Literature contains both good and bad examples of peak fitting. A common cause of poor peak fitting is the inclusion of too many fit parameters, often without a sound chemical and/or physical basis for them, and/or the failure to reasonably constrain them. Under these conditions, fit parameters are often correlated, and therefore lacking in statistical meaning. Here we introduce the uniqueness plot as a simple graphical tool for identifying bad peak fits in XPS, i.e., fit parameter correlation. These plots are widely used in spectroscopic ellipsometry. We illustrate uniqueness plots with two data sets: a C 1s narrow scan from ozone-treated carbon nanotube forests and an Si 2p narrow scan from an air-oxidized silicon wafer. For each fit, we consider different numbers of parameters and constraints on them. As expected, the uniqueness plots are parabolic when fewer fit parameters and/or more constraints are applied. However, they fan out and eventually become horizontal lines as more unconstrained parameters are included in the fits. Uniqueness plots are generated by plotting the chi squared (χ{sup 2}) value for a fit vs. a systematically varied value of a parameter in the fit. The Abbe criterion is also considered as a figure of merit for uniqueness plots in the Supporting Information. We recommend that uniqueness plots be used by XPS practitioners for identifying inappropriate peak fits.

  12. Line-narrowing in proton-detected nitrogen-14 NMR.

    Science.gov (United States)

    Cavadini, Simone; Vitzthum, Veronika; Ulzega, Simone; Abraham, Anuji; Bodenhausen, Geoffrey

    2010-01-01

    In solids spinning at the magic angle, the indirect detection of single-quantum (SQ) and double-quantum (DQ) (14)N spectra (I=1) via spy nuclei S=1/2 such as protons can be achieved in the manner of heteronuclear single- or multiple-quantum correlation (HSQC or HMQC) spectroscopy. The HMQC method relies on the excitation of two-spin coherences of the type T(11)(I)T(11)(S) and T(21)(I)T(11)(S) at the beginning of the evolution interval t(1). The spectra obtained by Fourier transformation from t(1) to omega(1) may be broadened by the homogenous decay of the transverse terms of the spy nuclei S. This broadening is mostly due to homonuclear dipolar S-S' interactions between the proton spy nuclei. In this work we have investigated the possibility of inserting rotor-synchronized symmetry-based C or R sequences and decoupling schemes such as Phase-Modulated Lee-Goldburg (PMLG) sequences in the evolution period. These schemes reduce the homonuclear proton-proton interactions and lead to an enhancement of the resolution of both SQ and DQ proton-detected (14)N HMQC spectra. In addition, we have investigated the combination of HSQC with symmetry-based sequences and PMLG and shown that the highest resolution in the (14)N dimension is achieved by using HSQC in combination with symmetry-based sequences of the R-type. We show improvements in resolution in samples of l-alanine and the tripeptide ala-ala-gly (AAG). In particular, for l-alanine the width of the (14)N SQ peak is reduced from 2 to 1.2 kHz, in agreement with simulations. We report accurate measurements of quadrupolar coupling constants and asymmetry parameters for amide (14)N in AAG peptide bonds.

  13. Peak heart rates at extreme altitudes

    DEFF Research Database (Denmark)

    Lundby, C; Van Hall, Gerrit

    2001-01-01

    We have measured maximal heart rate during a graded maximal bicycle exercise test to exhaustion in five healthy climbers before and during an expedition to Mt. Everest. Maximal heart rates at sea level were 186 (177-204) beats/min(-1) at sea level and 170 (169-182) beats/min(-1) with acute hypoxia....... After 1, 4 and 6 weeks of acclimatization to 5400 m, maximal heart rates were 155 (135-182), 158 (144-182), and 155 (140-183) beats/min(-1), respectively. Heart rates of two of the climbers were measured during their attempt to reach the summit of Mt. Everest without the use of supplemental oxygen....... The peak heart rates at 8,750 m for the two climbers were 142 and 144 beats/min(-1), which were similar to their maximal heart rates during exhaustive bicycle exercise at 5,400 m, the values being 144 and 148 beats/min(-1), respectively. The peak heart rates at 8,750 m are in agreement with other field...

  14. Equivalence Principle and the Baryon Acoustic Peak

    CERN Document Server

    Baldauf, Tobias; Simonović, Marko; Zaldarriaga, Matias

    2015-01-01

    We study the dominant effect of a long wavelength density perturbation $\\delta(\\lambda_L)$ on short distance physics. In the non-relativistic limit, the result is a uniform acceleration, fixed by the equivalence principle, and typically has no effect on statistical averages due to translational invariance. This same reasoning has been formalized to obtain a "consistency condition" on the cosmological correlation functions. In the presence of a feature, such as the acoustic peak at $l_{\\rm BAO}$, this naive expectation breaks down for $\\lambda_Lpeak, and is calculable to all orders in the long modes. This can be used to improve the result of perturbative calculations - a technique known as "infra-red resummation"- and is explicitly applied to the one-loop calculation of power spectrum. Finally, the success of BAO reconstruction schemes is argue...

  15. Microwave peak absorption frequency of liquid

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Microwave-assisted extraction is a new effective method which has practical ap-plications in many fields. Microwave heating is one of its physical mechanisms,and it also has the characteristic of selectivity. When the applied microwave fre-quency equals a certain absorption frequency of the material (or specific compo-nent),the material will intensively absorb microwave energy. This is also known as resonant absorption,and the frequency is called the peak absorption frequency which depends on the physical structure of the material. In this work,dynamic hy-drogen bond energy was included in molecular activation energy; with the liquid cell model,the expression of interaction energy between dipolar molecules was derived. The rotational relaxation time was gotten from the Eyring viscosity formula. Then based on the relationship between dielectric dissipation coefficient and re-laxation time,the expression of microwave peak absorption frequency as a func-tion of the material physical structure,rotational inertia and electrical dipole mo-ment of molecules was established. These theoretical formulas were applied to water and benzene,and the calculated results agree fairly well with the experi-mental data. This work can not only deepen the study of the interaction between microwave and material,but also provide a possible guide for the experiment of microwave-assisted extraction.

  16. Microwave peak absorption frequency of liquid

    Institute of Scientific and Technical Information of China (English)

    HAN GuangZe; CHEN MingDong

    2008-01-01

    Microwave-assisted extraction is a new effective method which has practical ap-plications in many fields. Microwave heating is one of its physical mechanisms, and it also has the characteristic of selectivity. When the applied microwave fre-quency equals a certain absorption frequency of the material (or specific compo-nent), the material will intensively absorb microwave energy. This is also known as resonant absorption, and the frequency is called the peak absorption frequency which depends on the physical structure of the material. In this work, dynamic hy-drogen bond energy was included in molecular activation energy; with the liquid cell model, the expression of interaction energy between dipolar molecules was derived. The rotational relaxation time was gotten from the Eyring viscosity formula. Then based on the relationship between dielectric dissipation coefficient and re-laxation time, the expression of microwave peak absorption frequency as a func-tion of the material physical structure, rotational inertia and electrical dipole mo-ment of molecules was established. These theoretical formulas were applied to water and benzene, and the calculated results agree fairly well with the experi-mental data. This work can not only deepen the study of the interaction between microwave and material, but also provide a possible guide for the experiment of microwave-assisted extraction.

  17. Method and apparatus for current-output peak detection

    Energy Technology Data Exchange (ETDEWEB)

    De Geronimo, Gianluigi

    2017-01-24

    A method and apparatus for a current-output peak detector. A current-output peak detector circuit is disclosed and works in two phases. The peak detector circuit includes switches to switch the peak detector circuit from the first phase to the second phase upon detection of the peak voltage of an input voltage signal. The peak detector generates a current output with a high degree of accuracy in the second phase.

  18. Two-dimensional double-quantum spectroscopy: peak shapes as a sensitive probe of carrier interactions in quantum wells

    CERN Document Server

    Tollerud, Jonathan O

    2016-01-01

    We identify carrier scattering at densities below which it has previously been observed in semiconductor quantum wells. These effects are evident in the peakshapes of 2D double-quantum spectra, which change as a function of excitation density. At high excitation densities ($\\geq 10^{9}$ carriers/,cm$^{-2}$) we observe untilted peaks similar to those reported in previous experiments. At low excitation densities (<$10^{8}$ carriers cm$^{-2}$) we observe narrower, tilted peaks. Using a simple simulation, we show that tilted peak-shapes are expected in double-quantum spectra when inhomogeneous broadening is much larger than homogeneous broadening, and that fast pure-decoherence of the double-quantum coherence can obscure this peak tilt. These results show that carrier interactions are important at lower densities than previously expected, and that the `natural' double-quantum peakshapes are hidden by carrier interactions at the excitation densities typically used. Furthermore, these results demonstrate that an...

  19. , Recorded at Ladron Peak, Central New Mexico

    Science.gov (United States)

    Ricketts, J. W.; Kelley, S.; Read, A. S.; Karlstrom, K. E.

    2010-12-01

    Ladron Peak, situated on the western flank of the Rio Grande rift ~30 miles NW of Socorro, NM, is composed of Precambrian granitic and metamorphic assemblages that have been faulted and uplifted during the late Tertiary formation of the rift. The area is bounded on three sides by normal faults, including the anomalously low-angle (~26°) Jeter fault to the east, which places Precambrian rocks in the footwall against Paleozoic and Mesozoic fault slivers, and mainly Cenozoic Santa Fe Group basin fill in the hanging wall. New apatite fission track (AFT) thermochronological data collected at 22 locations along the NE and SE margins of Ladron Peak give a range of ages from 10.9 ± 1.9 to 20.4 ± 8.6 Ma. Samples within the footwall include granitic and metasedimentary rocks that have mean track lengths of 13.1 to 14.1 μm; one quartzite sample has a mean track length of 12.5 μm, suggesting time in the partial annealing zone. Within the hanging wall block, new AFT ages from the Permian Bursum and Abo Formations give cooling ages of 23.1 ± 3.3 Ma. and 59.9 ± 12.4 Ma., respectively. The Bursum Formation sample, with a track length of 13.7 μm, cooled below the 110°C isotherm during the Miocene, while the Abo Formation sample, with a track length of 11.2 μm, was only partially reset prior to rift-related deformation. Mylonitized granitic and metamorphic rocks in the immediate footwall preserve dip-slip lineations that are parallel to slip on the Jeter fault. This suggests that strain associated with exhumation was recorded by both brittle and ductile deformation. Although this type of deformation is common within metamorphic core complexes in highly extended terranes, ductile normal faulting has not been recognized within the Rio Grande rift in New Mexico, though there is some suggestion of ductile deformation around Blanca Peak in the San Luis Valley in Colorado. These observations imply one or both of the following: (1) Ductile deformation at Ladron Peak was

  20. Validity of a trunk-mounted accelerometer to assess peak accelerations during walking, jogging and running.

    Science.gov (United States)

    Wundersitz, Daniel W T; Gastin, Paul B; Richter, Chris; Robertson, Samuel J; Netto, Kevin J

    2015-01-01

    The purpose of this study was to validate peak acceleration data from an accelerometer contained within a wearable tracking device while walking, jogging and running. Thirty-nine participants walked, jogged and ran on a treadmill while 10 peak accelerations per movement were obtained (n = 390). A single triaxial accelerometer measured resultant acceleration during all movements. To provide a criterion measure of acceleration, a 12-camera motion analysis (MA) system tracked the position of a retro-reflective marker affixed to the wearable tracking device. Peak raw acceleration recorded by the accelerometer significantly overestimated peak MA acceleration (P jog compared with walk and for run compared to both other movements. As the magnitude of acceleration increased, the strength of the relationship between the accelerometer and the criterion measure decreased. These results indicate that filtered accelerometer data provide an acceptable means of assessing peak accelerations, in particular for walking and jogging.

  1. Peak effect of flux pinning in Sc5Ir4Si10 superconductors

    Science.gov (United States)

    Sun, Y.; Shi, Z. X.; Gu, D. M.; Miura, M.; Tamegai, T.

    2010-10-01

    Magnetic hysteresis loops (MHLs) have been comparatively measured on both textured and single crystalline Sc5Ir4Si10 superconductors. Critical current densities and flux pinning forces are calculated from MHLs by Bean model. Three kinds of peaks of the flux pinning force are found at low fields near zero, intermediated fields, and high fields near the upper critical field, respectively. The characters and origins of these peaks are studied in detail.

  2. Peak Wind Tool for General Forecasting

    Science.gov (United States)

    Barrett, Joe H., III

    2010-01-01

    The expected peak wind speed of the day is an important forecast element in the 45th Weather Squadron's (45 WS) daily 24-Hour and Weekly Planning Forecasts. The forecasts are used for ground and space launch operations at the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS). The 45 WS also issues wind advisories for KSC/CCAFS when they expect wind gusts to meet or exceed 25 kt, 35 kt and 50 kt thresholds at any level from the surface to 300 ft. The 45 WS forecasters have indicated peak wind speeds are challenging to forecast, particularly in the cool season months of October - April. In Phase I of this task, the Applied Meteorology Unit (AMU) developed a tool to help the 45 WS forecast non-convective winds at KSC/CCAFS for the 24-hour period of 0800 to 0800 local time. The tool was delivered as a Microsoft Excel graphical user interface (GUI). The GUI displayed the forecast of peak wind speed, 5-minute average wind speed at the time of the peak wind, timing of the peak wind and probability the peak speed would meet or exceed 25 kt, 35 kt and 50 kt. For the current task (Phase II ), the 45 WS requested additional observations be used for the creation of the forecast equations by expanding the period of record (POR). Additional parameters were evaluated as predictors, including wind speeds between 500 ft and 3000 ft, static stability classification, Bulk Richardson Number, mixing depth, vertical wind shear, temperature inversion strength and depth and wind direction. Using a verification data set, the AMU compared the performance of the Phase I and II prediction methods. Just as in Phase I, the tool was delivered as a Microsoft Excel GUI. The 45 WS requested the tool also be available in the Meteorological Interactive Data Display System (MIDDS). The AMU first expanded the POR by two years by adding tower observations, surface observations and CCAFS (XMR) soundings for the cool season months of March 2007 to April 2009. The POR was expanded

  3. Sharp and Bright Photoluminescence Emission of Single Crystalline Diacetylene Nanoparticles

    CERN Document Server

    Kima, Seokho; Kima, Hyeong Tae; Cuic, Chunzhi; Park, Dong Hyuk

    2016-01-01

    Amorphous nanoparticles (NPs) of diacetylene (DA) molecules were prepared by using a reprecipitation method. After crystallization through solvent-vapor annealing process, the highly crystalline DA NPs show different structural and optical characteristics compared with the amorphous DA NPs. The single crystal structure of DA NPs was confirmed by high-resolution transmission electron microscopy (HR-TEM) and wide angle X-ray scattering (WAXS). The luminescence color and photoluminescence (PL) characteristics of the DA NPs were measured using color charge-coupled device (CCD) images and high-resolution laser confocal microscope (LCM). The crystalline DA NPs emit bright green light emission compared with amorphous DA NPs and the main PL peak of the crystalline DA NPs exhibits relative narrow and blue shift phenomena due to enhanced interaction between DA molecular in the nano-size crystal structure.

  4. Prospects for a Narrow Line MOT in YO

    CERN Document Server

    Collopy, Alejandra L; Yeo, Mark; Yan, Bo; Ye, Jun

    2015-01-01

    In addition to being suitable for laser cooling and trapping in a magneto-optical trap (MOT) using a relatively broad ($\\sim$5 MHz) transition, the molecule YO possesses a narrow-line transition. This forbidden transition between the $X^{2}\\Sigma$ and $A'^{2}\\Delta_{3/2}$ states has linewidth $\\sim$2$\\pi\\times$160 kHz. After cooling in a MOT on the $X^{2}\\Sigma$ to $A^{2}\\Pi_{1/2}$ (orange) transition, the narrow (red) transition can be used to further cool the sample, requiring only minimal additions to the first stage system. The narrow line cooling stage will bring the temperature from $\\sim$1 mK to $\\sim$10 $\\mu$K, significantly advancing the frontier on direct cooling achievable for molecules.

  5. Prospects for a narrow line MOT in YO

    Science.gov (United States)

    Collopy, Alejandra L.; Hummon, Matthew T.; Yeo, Mark; Yan, Bo; Ye, Jun

    2015-05-01

    In addition to being suitable for laser cooling and trapping in a magneto-optical trap (MOT) using a relatively broad (∼ 5 MHz) transition, the molecule YO possesses a narrow-line transition. This forbidden transition between the {{X}2}Σ and A{{\\prime }2}{{Δ }3/2} states has linewidth ∼ 2π × 160 kHz. After cooling in a MOT on the 614 nm {{X}2}Σ to {{A}2}{{\\Pi }1/2} (orange) transition, the narrow 690 nm (red) transition can be used to further cool the sample, requiring only minimal additions to the first stage system. We estimate that the narrow line cooling stage will bring the temperature from ∼1 mK to ∼10 μK, significantly advancing the frontier on direct cooling achievable for molecules.

  6. Multilayer Photonic Crystal for Spectral Narrowing of Emission

    Directory of Open Access Journals (Sweden)

    Zhanfang LIU

    2017-08-01

    Full Text Available Multilayer colloidal crystal has been prepared by the layer-by-layer deposition of silica microspheres on a glass slide. Each layer is a slab consisting of a fcc close-packed colloidal arrays. By properly choosing the sizes of spheres, the whole spectral feature of multilayer colloidal crystal can be tuned. Here, we engineered a multilayer superlattice structure with an effective passband between two stop bands. This gives a strong narrowing effect on emission spectrum. With the stop bands at the shortwave and longwave edges of emission spectrum, the passband in the central wavelength region can be regarded as a strong decrease of suppression effect and enhancement of a narrow wavelength region of emission. The spectral narrowing modification effect of suitably engineered colloidal crystals shows up their importance in potential application as optical filters and lasing devices.DOI: http://dx.doi.org/10.5755/j01.ms.23.3.16320

  7. Thermoviscoelastic dynamic response for a composite material thin narrow strip

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Hong Liang; Qi, Li-Li; Liu, Hai-Bo [Hunan University, Changsha (China)

    2015-02-15

    Based on von Karman nonlinear strain-displacement relationships and classical thin plate theory, a list of nonlinear dynamic equilibrium equations for a viscoelastic composite material thin narrow strip under thermal and mechanic loads are deduced. According to the material constitutive relationship and the relaxation modulus in the form of the Prony series, combing with the Newmark method and the Newton-cotes integration method, a new numerical algorithm for direct solving the whole problem in the time domain is established. By applying this numerical algorithm, the viscoelastic composite material thin narrow strip as the research subject is analyzed systematically, and its rich dynamical behaviors are revealed comprehensively. To verify the accuracy of the present work, a comparison is made with previously published results. Finally, the viscoelastic composite material thin narrow strip under harmonic excitation load and impact load are discussed in detail, and many valuable thermoviscoelastic dynamic characteristics are revealed.

  8. Finding Multiple Peaks Signal in Fast Beam Conditions Monitor (BCM1F)

    CERN Document Server

    Bin Ab Maalek, Abu Ubaidah Amir; CERN. Geneva. EP Department

    2017-01-01

    Fast Beam Conditions Monitor (BCM1F) is diamond and silicon sensors based luminometer of CMS detector. The methods of finding multiple peaks signal in BCM1F is shown. Multiple peaks signal found at signal with width between 60 ns - 300 ns. Double peaks are counted as single hit in the constant threshold analysis and leads to underestimation in the luminosity. Therefore it should be estimated for different filling schemes and sensor types. The percentage of long width pulse in different sensor for different fill are calculated. About 30 \\% long width pulse found in sCVD sensor, 12 \\% in pCVD and no more than 1 \\% for silicon sensor.

  9. Dominant Laplace DLTS peaks E280 and E290 in melt-grown ZnO

    Energy Technology Data Exchange (ETDEWEB)

    Scheffler, Leopold; Kolkovsky, Vladimir; Weber, Joerg [Technische Universitaet Dresden, 01062 Dresden (Germany)

    2011-07-01

    In the present study single-crystal ZnO grown from the melt was investigated by electrical measurements such as DLTS and high-resolution Laplace DLTS. A peak E280 dominates the DLTS spectrum in the wide temperature range of 20-450 K. Using high-resolution Laplace DLTS this peak was found to consist of two levels with activation energies of 280 meV and 290 meV below the conduction band, respectively. The relative intensities of these peaks depend on the measurement temperature. The thermal stability of the defects in oxygen and oxygen-lean atmosphere is analyzed. The origin of these defects is discussed.

  10. Peak Electric Load Relief in Northern Manhattan

    Directory of Open Access Journals (Sweden)

    Hildegaard D. Link

    2014-08-01

    Full Text Available The aphorism “Think globally, act locally,” attributed to René Dubos, reflects the vision that the solution to global environmental problems must begin with efforts within our communities. PlaNYC 2030, the New York City sustainability plan, is the starting point for this study. Results include (a a case study based on the City College of New York (CCNY energy audit, in which we model the impacts of green roofs on campus energy demand and (b a case study of energy use at the neighborhood scale. We find that reducing the urban heat island effect can reduce building cooling requirements, peak electricity loads stress on the local electricity grid and improve urban livability.

  11. Tim Peake and Britain's road to space

    CERN Document Server

    Seedhouse, Erik

    2017-01-01

    This book puts the reader in the flight suit of Britain’s first male astronaut, Tim Peake. It chronicles his life, along with the Principia mission and the down-to-the-last-bolt descriptions of life aboard the ISS, by way of the hurdles placed by the British government and the rigors of training at Russia’s Star City military base. In addition, this book discusses the learning curves required in astronaut and mission training and the complexity of the technologies required to launch an astronaut and keep them alive for months on end. This book underscores the fact that technology and training, unlike space, do not exist in a vacuum; complex technical systems, like the ISS, interact with the variables of human personality, and the cultural background of the astronauts. .

  12. Optogenetic Central Amygdala Stimulation Intensifies and Narrows Motivation for Cocaine.

    Science.gov (United States)

    Warlow, Shelley M; Robinson, Mike J F; Berridge, Kent C

    2017-08-30

    Addiction is often characterized by intense motivation for a drug, which may be narrowly focused at the expense of other rewards. Here, we examined the role of amygdala-related circuitry in the amplification and narrowing of motivation focus for intravenous cocaine. We paired optogenetic channelrhodopsin (ChR2) stimulation in either central nucleus of amygdala (CeA) or basolateral amygdala (BLA) of female rats with one particular nose-poke porthole option for earning cocaine infusions (0.3 mg/kg, i.v.). A second alternative porthole earned identical cocaine but without ChR2 stimulation. Consequently, CeA rats quickly came to pursue their CeA ChR2-paired cocaine option intensely and exclusively, elevating cocaine intake while ignoring their alternative cocaine alone option. By comparison, BLA ChR2 pairing failed to enhance cocaine motivation. CeA rats also emitted consummatory bites toward their laser-paired porthole, suggesting that higher incentive salience made that cue more attractive. A separate progressive ratio test of incentive motivation confirmed that CeA ChR2 amplified rats' motivation, raising their breakpoint effort price for cocaine by 10-fold. However, CeA ChR2 laser on its own lacked any reinforcement value: laser by itself was never self-stimulated, not even by the same rats in which it amplified motivation for cocaine. Conversely, CeA inhibition by muscimol/baclofen microinjections prevented acquisition of cocaine self-administration and laser preference, whereas CeA inhibition by optogenetic halorhodopsin suppressed cocaine intake, indicating that CeA circuitry is needed for ordinary cocaine motivation. We conclude that CeA ChR2 excitation paired with a cocaine option specifically focuses and amplifies motivation to produce intense pursuit and consumption focused on that single target.SIGNIFICANCE STATEMENT In addiction, intense incentive motivation often becomes narrowly focused on a particular drug of abuse. Here we show that pairing central

  13. Search for narrow resonances lighter than Upsilon mesons

    Energy Technology Data Exchange (ETDEWEB)

    Aaltonen, T.; /Helsinki Inst. of Phys.; Adelman, Jahred A.; /Chicago U., EFI; Akimoto, T.; /Tsukuba U.; Alvarez Gonzalez, B.; /Cantabria Inst. of Phys.; Amerio, S.; /INFN, Padua; Amidei, Dante E.; /Michigan U.; Anastassov, A.; /Northwestern U.; Annovi, Alberto; /Frascati; Antos, Jaroslav; /Comenius U.; Apollinari, G.; /Fermilab; Apresyan, A.; /Purdue U. /Waseda U.

    2009-03-01

    We report a search for narrow resonances, produced in p{bar p} collisions at {radical}s = 1.96 TeV, that decay into muon pairs with invariant mass between 6.3 and 9.0 GeV/c{sup 2}. The data, collected with the CDF II detector at the Fermilab Tevatron collider, correspond to an integrated luminosity of 630 pb{sup -1}. We use the dimuon invariant mass distribution to set 90% upper credible limits of about 1% to the ratio of the production cross section times muonic branching fraction of possible narrow resonances to that of the {Upsilon}(1S) meson.

  14. Infrared Perfect Ultra-narrow Band Absorber as Plasmonic Sensor

    OpenAIRE

    Wu, Dong; Liu, Yumin; Li, Ruifang; Chen, Lei; Ma, Rui; Liu, Chang; Ye, Han

    2016-01-01

    We propose and numerically investigate a novel perfect ultra-narrow band absorber based on a metal-dielectric-metal-dielectric-metal periodic structure working at near-infrared region, which consists of a dielectric layer sandwiched by a metallic nanobar array and a thin gold film over a dielectric layer supported by a metallic film. The absorption efficiency and ultra-narrow band of the absorber are about 98 % and 0.5 nm, respectively. The high absorption is contributed to localized surface ...

  15. High power diode laser array development using completely indium free packaging technology with narrow spectrum

    Science.gov (United States)

    Hou, Dong; Wang, Jingwei; Gao, Lijun; Liang, Xuejie; Li, Xiaoning; Liu, Xingsheng

    2016-03-01

    The high power diode lasers have been widely used in many fields. In this work, a sophisticated high power and high performance horizontal array of diode laser stacks have been developed and fabricated with high duty cycle using hard solder bonding technology. CTE-matched submount and Gold Tin (AuSn) hard solder are used for bonding the diode laser bar to achieve the performances of anti-thermal fatigue, higher reliability and longer lifetime. This array consists of 30 bars with the expected optical output peak power of 6000W. By means of numerical simulation and analytical results, the diode laser bars are aligned on suitable positions along the water cooled cooler in order to achieve the uniform wavelength with narrow spectrum and accurate central wavelength. The performance of the horizontal array, such as output power, spectrum, thermal resistance, life time, etc., is characterized and analyzed.

  16. High resolution electron energy loss spectroscopy of narrow gap III-V semiconductor surfaces and interfaces

    CERN Document Server

    Veal, T D

    2002-01-01

    The electronic properties of n-type narrow gap III-V semiconductor surfaces and interfaces are investigated using high-resolution electron-energy-loss spectroscopy (HREELS). Changing the incident electron energy, alters the wave-vector transfer parallel to the surface, allowing the probing depth to be varied over typical space-charge layer widths (100 - 2000 A). Semi-classical dielectric theory simulations of the HREEL spectra are performed to extract quantitative information from the probing energy-dependence of the surface plasmon and phonon peaks. The plasma frequency used in the simulations is related to the electron concentration and effective mass using the Kane model of the non-parabolic conduction band. Space-charge layer parameters are obtained by comparing calculated smooth charge profiles with the histogram profiles that are used in the simulations. Complementary experimental techniques are employed to correlate the reconstruction, chemical composition and morphology of the surface with the electro...

  17. Compact Narrow Linewidth Actively Q-Switched Er–Yb Double-Clad Fiber Laser

    Directory of Open Access Journals (Sweden)

    Berenice Posada-Ramírez

    2017-06-01

    Full Text Available Actively Q-switched laser operation of a narrow linewidth compact fiber laser based on an Er–Yb double-clad fiber is presented. The laser linewidth as a function of the repetition rate and the Q-switched pulses characteristics for different pump powers are experimentally analyzed. Stable Q-switched laser operation with spectral laser linewidth of 73 pm in a repetition rate range from 90 to 270 kHz is obtained. The minimum pulse duration of 178 ns, maximum peak power of 30.5 W, and maximum pulse energy of 5.4 µJ are observed. The maximum average power reached is 1.1 W.

  18. Searches for narrow resonances decaying to pairs of boosted HH bosons

    CERN Document Server

    De Souza Santos, Angelo

    2016-01-01

    We present a search for narrow resonances production in gluon-gluon fusion followed by a decay into two Higgs bosons at 8 and 13 TeV. Decays of Higgs bosons into bottom quark pairs are considered for resonance massesabove 1 TeV, where each Higgs boson is produced with large momentum, and thehadronization products of the pair of bottom quarks can usually be reconstructed assingle large jets. The background from multijet and its events is significantly reducedby applying requirements related to the flavor of the jet, its mass, and its substructure.The signal is identified as a peak in the dijet invariant mass spectrum of the remain-ing background events.

  19. Search for narrow resonances in pp. -->. p. pi. /sup +/n at 2 GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Sauer, J.R.; Wicklund, A.B.; Arenton, M.W.

    1980-07-01

    A preliminary analysis of an experiment designed as a sensitive dibaryon resonance search in the reaction pp..-->..p..pi../sup +/n is presented. At 2 GeV/c incident momentum, 440,000 unambiguously reconstructed events were obtained. In this preliminary analysis, the results are reported of a search of the pn mass spectrum for evidence of chain decays of possible dibaryon resonances, i.e. pp..-->..d/sup **/, d/sup **/..-->..d/sup **/..pi../sup +/, d/sup */..-->..pn. No evidence of narrow peaks (less than or equal to 7 MeV) is seen in the data for cross-section-times-branching-ratio greater than 50 ..mu..b.

  20. MINUTE-SCALE RAPID VARIABILITY OF THE OPTICAL POLARIZATION IN THE NARROW-LINE SEYFERT 1 GALAXY PMN J0948+0022

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Ryosuke; Tanaka, Yasuyuki T.; Fukazawa, Yasushi; Kawaguchi, Kenji; Takaki, Katsutoshi; Ueno, Issei [Department of Physical Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Kawabata, Koji S.; Moritani, Yuki; Uemura, Makoto; Akitaya, Hiroshi; Yoshida, Michitoshi; Ohsugi, Takashi [Hiroshima Astrophysical Science Center, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Hanayama, Hidekazu; Miyaji, Takeshi [Ishigakijima Astronomical Observatory, National Astronomical Observatory of Japan, 1024-1 Arakawa, Ishigaki, Okinawa 907-0024 (Japan); Kawai, Nobuyuki, E-mail: itoh@hep01.hepl.hiroshima-u.ac.jp [Department of Physics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan)

    2013-09-20

    We report on optical photopolarimetric results of the radio-loud narrow-line Seyfert 1 (RL-NLSy1) galaxy PMN J0948+0022 on 2012 December to 2013 February triggered by flux enhancements in the near infrared and γ-ray bands. With the one-shot polarimetry of the Hiroshima One-shot Wide field Polarimeter installed on the Kanata Telescope, we detected very rapid variability in the polarized-flux (PF) light curve on MJD 56281 (2012 December 20). The rise and decay times were about 140 s and 180 s, respectively. The polarization degree (PD) reached 36% ± 3% at the peak of the short-duration pulse, while the polarization angle remained almost constant. In addition, temporal profiles of the total flux and PD showed highly variable but well correlated behavior and discrete correlation function analysis revealed that no significant time lag of more than 10 minutes was present. The high PD and minute-scale variability in PF provides clear evidence of synchrotron radiation from a very compact emission region of ∼10{sup 14} cm size with a highly ordered magnetic field. Such micro-variability of polarization is also observed in several blazar jets, but its complex relation between total flux and PD are explained by a multi-zone model in several blazars. The implied single emission region in PMN J0948+0022 might reflect a difference of jets between RL-NLSy1s and blazars.

  1. Nature of the narrow optical band in H*-aggregates: Dozy-chaos-exciton coupling

    Science.gov (United States)

    Egorov, Vladimir V.

    2014-07-01

    Dozy chaos emerges as a combined effect of the collective chaotic motion of electrons and nuclei, and their chaotic electromagnetic interactions in the transient state of molecules experiencing quantum transitions. Following earlier discussions of the well-known Brönsted relations for proton-transfer reactions; the temperature-dependent electron transfer in Langmuir-Blodgett films; the shape of the optical bands of polymethine dye monomers, their dimers, and J-aggregates, this paper reports one more application of the dozy-chaos theory of molecular quantum transitions. The qualitative and quantitative explanations for shape of a narrow and blue-shifted optical absorption band in H*-aggregates is given on the basis of the dozy-chaos theory by taking into account the dozy-chaos-exciton coupling effect. It is emphasized that in the H*-aggregate chromophore (dimer of cyclic bis-thiacarbocyanines) there is a competition between two Frenkel exciton transitions through the chaotic reorganization motion of nuclear environment. As a result, the highly organized quantum transition to the upper exciton state becomes an exciton-induced source of dozy chaos for the low organized transition to the lower exciton state. This manifests itself in appearing the narrow peak and broad wing in the optical spectrum pattern of H*-aggregates. A similar enhancement in the H*-effect caused by the strengthening of the exciton coupling in H*-dimers, which could be achieved by synthesizing tertiary and quarternary thiacarbocyanine monomers, is predicted.

  2. Synthesis and characterization of mesoporous ZnS with narrow size distribution of small pores

    Science.gov (United States)

    Nistor, L. C.; Mateescu, C. D.; Birjega, R.; Nistor, S. V.

    2008-08-01

    Pure, nanocrystalline cubic ZnS forming a stable mesoporous structure was synthesized at room temperature by a non-toxic surfactant-assisted liquid liquid reaction, in the 9.5 10.5 pH range of values. The appearance of an X-ray diffraction (XRD) peak in the region of very small angles (˜ 2°) reveals the presence of a porous material with a narrow pore size distribution, but with an irregular arrangement of the pores, a so-called worm hole or sponge-like material. The analysis of the wide angle XRD diffractograms shows the building blocks to be ZnS nanocrystals with cubic structure and average diameter of 2 nm. Transmission electron microscopy (TEM) investigations confirm the XRD results; ZnS crystallites of 2.5 nm with cubic (blende) structure are the building blocks of the pore walls with pore sizes from 1.9 to 2.5 nm, and a broader size distribution for samples with smaller pores. Textural measurements (N2 adsorption desorption isotherms) confirm the presence of mesoporous ZnS with a narrow range of small pore sizes. The relatively lower surface area of around 100 m2/g is attributed to some remaining organic molecules, which are filling the smallest pores. Their presence, confirmed by IR spectroscopy, seems to be responsible for the high stability of the resulting mesoporous ZnS as well.

  3. Nanophotonic hybridization of narrow atomic cesium resonances and photonic stop gaps of opaline nanostructures

    CERN Document Server

    Harding, Philip J; Mosk, Allard P; Vos, Willem L

    2014-01-01

    We study a hybrid system consisting of a narrowband atomic optical resonance and the long-range periodic order of an opaline photonic nanostructure. To this end, we have infiltrated atomic cesium vapor in a thin silica opal photonic crystal. With increasing temperature, the frequencies of the opal's reflectivity peaks shift down by >20% due to chemical reduction of the silica. Simultaneously, the photonic bands and gaps shift relative to the fixed near-infrared cesium D1 transitions. As a result the narrow atomic resonances with high finesse (f/df=8E5) dramatically change shape from a usual dispersive shape at the blue edge of a stop gap, to an inverted dispersion lineshape at the red edge of a stop gap. The lineshape, amplitude, and off-resonance reflectivity are well modeled with a transfer-matrix model that includes the dispersion and absorption of Cs hyperfine transitions and the chemically-reduced opal. An ensemble of atoms in a photonic crystal is an intriguing hybrid system that features narrow defect-...

  4. A narrow-band, variable energy ion source derived from a wire plasma source

    Energy Technology Data Exchange (ETDEWEB)

    Gueroult, R; Elias, P Q; Packan, D [ONERA Palaiseau, 91761 Palaiseau (France); Rax, J M, E-mail: renaud.gueroult@polytechnique.edu [LPP, Ecole Polytechnique, 91128 Palaiseau Cedex (France)

    2011-08-15

    A low pressure wire-induced plasma source (WIPS) operated in its high-pressure mode ({approx}10{sup -2} mbar) exhibits a narrow ion energy distribution function peaked at an energy corresponding to the discharge voltage. In order to take advantage of this peculiar feature, we design an electrode geometry enabling the acceleration of ions extracted from a WIPS. Probing of the obtained ion plume by means of a retarding potential analyser (RPA) demonstrates the capability of such an ion source to generate narrow-band (full width at half maximum of about 20 eV), variable energy (1 to 5 keV) ion beams. Comparison with particle-in-cell simulations of the WIPS shows that the energy spread of these ion beams is actually about 10 eV, the slight broadening being mainly the effect of the limited planar RPA energy resolution. The ion beam spot size measured at 6 cm of the ion source exit is about 3 mm for a 10 {mu}A He{sup +} beam at 2 keV, with a divergence of about one degree. Operating the WIPS in argon and xenon leads to similar properties for Ar{sup +} and Xe{sup +} beams, and in principle other species could also be used.

  5. Nature of the narrow optical band in H*-aggregates: Dozy-chaos–exciton coupling

    Directory of Open Access Journals (Sweden)

    Vladimir V. Egorov

    2014-07-01

    Full Text Available Dozy chaos emerges as a combined effect of the collective chaotic motion of electrons and nuclei, and their chaotic electromagnetic interactions in the transient state of molecules experiencing quantum transitions. Following earlier discussions of the well-known Brönsted relations for proton-transfer reactions; the temperature-dependent electron transfer in Langmuir–Blodgett films; the shape of the optical bands of polymethine dye monomers, their dimers, and J-aggregates, this paper reports one more application of the dozy-chaos theory of molecular quantum transitions. The qualitative and quantitative explanations for shape of a narrow and blue-shifted optical absorption band in H*-aggregates is given on the basis of the dozy-chaos theory by taking into account the dozy-chaos–exciton coupling effect. It is emphasized that in the H*-aggregate chromophore (dimer of cyclic bis-thiacarbocyanines there is a competition between two Frenkel exciton transitions through the chaotic reorganization motion of nuclear environment. As a result, the highly organized quantum transition to the upper exciton state becomes an exciton-induced source of dozy chaos for the low organized transition to the lower exciton state. This manifests itself in appearing the narrow peak and broad wing in the optical spectrum pattern of H*-aggregates. A similar enhancement in the H*-effect caused by the strengthening of the exciton coupling in H*-dimers, which could be achieved by synthesizing tertiary and quarternary thiacarbocyanine monomers, is predicted.

  6. Synthesis of iron oxide nanoparticles of narrow size distribution on polysaccharide templates

    Indian Academy of Sciences (India)

    M Nidhin; R Indumathy; K J Sreeram; Balachandran Unni Nair

    2008-02-01

    We report here the preparation of nanoparticles of iron oxide in the presence of polysaccharide templates. Interaction between iron (II) sulfate and template has been carried out in aqueous phase, followed by the selective and controlled removal of the template to achieve narrow distribution of particle size. Particles of iron oxide obtained have been characterized for their stability in solvent media, size, size distribution and crystallinity and found that when the negative value of the zeta potential increases, particle size decreases. A narrow particle size distribution with 100 = 275 nm was obtained with chitosan and starch templates. SEM measurements further confirm the particle size measurement. Diffuse reflectance UV–vis spectra values show that the template is completely removed from the final iron oxide particles and powder XRD measurements show that the peaks of the diffractogram are in agreement with the theoretical data of hematite. The salient observations of our study shows that there occurs a direct correlation between zeta potential, polydispersity index, bandgap energy and particle size. The crystallite size of the particles was found to be 30–35 nm. A large negative zeta potential was found to be advantageous for achieving lower particle sizes, owing to the particles remaining discrete without agglomeration.

  7. Peak, multi-peak and broadband absorption in graphene-based one-dimensional photonic crystal

    Science.gov (United States)

    Miloua, R.; Kebbab, Z.; Chiker, F.; Khadraoui, M.; Sahraoui, K.; Bouzidi, A.; Medles, M.; Mathieu, C.; Benramdane, N.

    2014-11-01

    We theoretically investigate the possibility of enhancing light absorption in graphene-based one dimensional photonic crystal. We demonstrate that it is possible to achieve total light absorption at technologically important wavelengths using one-dimensional graphene-based photonic crystals. By means of the transfer matrix method, we investigate the effect of refractive indices and layer numbers on the optical response of the structure. We found that it is possible to achieve one peak, multi-peak or broadband, and complete optical absorption. As a result, the proposed photonic structures enable myriad potential applications such as photodetection, shielding and optical sensing.

  8. Narrow multibeam satellite ground station antenna employing a linear array with a geosynchronous arc coverage of 60 deg. I - Theory

    Science.gov (United States)

    Amitay, N.; Gans, M. J.

    1982-11-01

    The feasibility of using an appropriately squinted linear scan in narrow multibeam satellite ground station antennas employing phased arrays is demonstrated. This linear scan has the potential of reducing the complexity of a narrow-beam planar array to that of a linear array. Calculations for such antennas placed at cities throughout the U.S. show that the peak beam pointing error in covering the 70 deg W to 130 deg W geosynchronous equatorial arc (GEA) is under 5/1000th of a degree. Communication at a 300 MBd rate in the 12/14 GHz band can be made feasible, for a grating lobe-free scan and 0.5 deg beamwidth antenna, by using a relatively simple time equalization.

  9. Lower extremity injury in female basketball players is related to a large difference in peak eversion torque between barefoot and shod conditions

    Directory of Open Access Journals (Sweden)

    Jennifer M. Yentes

    2014-09-01

    Conclusion: It is possible that a large discrepancy between strength in barefoot and shod conditions can predispose an athlete to injury. Narrowing the difference in peak eversion torque between barefoot and shod could decrease propensity to injury. Future work should investigate the effect of restoration of muscular strength during barefoot and shod exercise on injury rates.

  10. VLBI IMAGING OF THE DOUBLE PEAKED EMISSION LINE SEYFERT KISSR 1494

    Energy Technology Data Exchange (ETDEWEB)

    Kharb, P.; Das, M.; Subramanian, S.; Chitta, L. P. [Indian Institute of Astrophysics, II Block, Koramangala, Bangalore 560034 (India); Paragi, Z., E-mail: kharb@iiap.res.in [Joint Institute for VLBI in Europe, Postbus 2, 7990 AA Dwingeloo (Netherlands)

    2015-02-01

    We present here the results from dual-frequency phase-referenced Very Long Baseline Interferometry observations of the Seyfert galaxy KISSR 1494, which exhibits double peaked emission lines in its Sloan Digital Sky Survey spectrum. We detect a single radio component at 1.6 GHz, but not at 5 GHz, implying a spectral index steeper than –1.5 ± 0.5 (S {sub ν}∝ν{sup α}). The high brightness temperature of the radio component (∼1.4 × 10{sup 7} K) and the steep radio spectrum support a non-thermal synchrotron origin. A crude estimate of the black hole mass derived from the M {sub BH}-σ{sub *} relation is ∼1.4 ± 1.0 × 10{sup 8} M {sub ☉}; it is accreting at an Eddington rate of ∼0.02. The radio data are consistent with either the radio emission coming from the parsec-scale base of a synchrotron wind originating in the magnetized corona above the accretion disk, or from the inner ionized edge of the accretion disk or torus. In the former case, the narrow line region (NLR) clouds may form a part of the broad outflow, while in the latter, the NLR clouds may form a part of an extended disk beyond the torus. The radio and NLR emission may also be decoupled so that the radio emission originates in an outflow while the NLR is in a disk and vice versa. While with the present data it is not possible to clearly distinguish between these scenarios, there appears to be greater circumstantial evidence supporting the coronal wind picture in KISSR 1494. From the kiloparsec-scale radio emission, the time-averaged kinetic power of this outflow is estimated to be Q ≈ 1.5 × 10{sup 42} erg s{sup –1}, which is typical of radio outflows in low-luminosity active galactic nuclei. This supports the idea that radio ''jets'' and outflowing coronal winds are indistinguishable in Seyfert galaxies.

  11. Norwegian hydropower a valuable peak power source

    Energy Technology Data Exchange (ETDEWEB)

    Brekke, Hermod

    2010-07-01

    given on a possible increase of the Norwegian hydropower peak power production to meet the growing the European demand for peak power caused by the growing non stationary production from wind mills and ocean energy from waves and sea current. Also building of reversible pump turbine power plants will be discussed even if approximately 10% power will be consumed by loss in the pumping phase compared to direct use of the water from reservoirs. (Author)

  12. Narrow-Band WGM Optical Filters With Tunable FSRs

    Science.gov (United States)

    Mohageg, Makan; Matsko, Andrey; Savchenkov, Anatoliy; Maleki, Lute; Iltchenko, Vladimir; Strekalov, Dmitry

    2007-01-01

    Optical resonators of the whispering-gallery-mode (WGM) type featuring DC-tunable free spectral ranges (FSRs) have been demonstrated. By making the FSR tunable, one makes it possible to adjust, during operation, the frequency of a microwave signal generated by an optoelectronic oscillator in which an WGM optical resonator is utilized as a narrow-band filter.

  13. Elongational viscosity of narrow molar mass distribution polystyrene

    DEFF Research Database (Denmark)

    Bach, Anders; Almdal, Kristoffer; Rasmussen, Henrik Koblitz

    2003-01-01

    Transient and steady elongational viscosity has been measured for two narrow molar mass distribution polystyrene melts of molar masses 200 000 and 390 000 by means of a filament stretching rheometer. Total Hencky strains of about five have been obtained. The transient elongational viscosity rises...

  14. Nonstationary Narrow-Band Response and First-Passage Probability

    DEFF Research Database (Denmark)

    Krenk, Steen

    1979-01-01

    The notion of a nonstationary narrow-band stochastic process is introduced without reference to a frequency spectrum, and the joint distribution function of two consecutive maxima is approximated by use of an envelope. Based on these definitions the first passage problem is treated as a Markov po...

  15. Molecular targets of Narrow-Band UVB Phototherapy in Psoriasis

    NARCIS (Netherlands)

    E. Rácz (Emőke)

    2009-01-01

    textabstractPsoriasis is a chronic inflammatory skin disease that affects 2-3% of the Western population. The aim of this thesis was to illuminate the molecular effects of narrow-band (NB-) UVB phototherapy, a highly effective systemic treatment modality in psoriasis, in order to clarify the mechani

  16. 33 CFR 162.240 - Tongass Narrows, Alaska; navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Tongass Narrows, Alaska; navigation. 162.240 Section 162.240 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY INLAND WATERWAYS NAVIGATION REGULATIONS § 162.240...

  17. Mechanical properties of Indonesian-made narrow dynamic compression plate.

    Science.gov (United States)

    Dewo, P; van der Houwen, E B; Sharma, P K; Magetsari, R; Bor, T C; Vargas-Llona, L D; van Horn, J R; Busscher, H J; Verkerke, G J

    2012-09-01

    Osteosynthesis plates are clinically used to fixate and position a fractured bone. They should have the ability to withstand cyclic loads produced by muscle contractions and total body weight. The very high demand for osteosynthesis plates in developing countries in general and in Indonesia in particular necessitates the utilisation of local products. In this paper, we investigated the mechanical properties, i.e. proportional limit and fatigue strength of Indonesian-made Narrow Dynamic Compression Plates (Narrow DCP) as one of the most frequently used osteosynthesis plates, in comparison to the European AO standard plate, and its relationship to geometry, micro structural features and surface defects of the plates. All Indonesian-made plates appeared to be weaker than the standard Narrow DCP because they consistently failed at lower stresses. Surface defects did not play a major role in this, although the polishing of the Indonesian Narrow DCP was found to be poor. The standard plate showed indications of cold deformation from the production process in contrast to the Indonesian plates, which might be the first reason for the differences in strength. This is confirmed by hardness measurements. A second reason could be the use of an inferior version of stainless steel. The Indonesian plates showed lower mechanical behaviour compared to the AO-plates. These findings could initiate the development of improved Indonesian manufactured DCP-plates with properties comparable to commonly used plates, such as the standard European AO-plates.

  18. Gain-switched all-fiber laser with narrow bandwidth

    DEFF Research Database (Denmark)

    Larsen, Casper; Giesberts, M.; Nyga, S.;

    2013-01-01

    Gain-switching of a CW fiber laser is a simple and cost-effective approach to generate pulses using an all-fiber system. We report on the construction of a narrow bandwidth (below 0.1 nm) gain-switched fiber laser and optimize the pulse energy and pulse duration under this constraint. The extracted...

  19. Electronic structure of heavy fermions: narrow temperature-independent bands

    Energy Technology Data Exchange (ETDEWEB)

    Arko, A.J.; Joyce, J.J.; Andrews, A.B.; Thompson, J.D.; Smith, J.L. [Los Alamos National Lab., NM (United States); Moshopoulou, E.; Fisk, Z. [NHMFL, Florida State Univ., Tallahassee, FL (United States); Menovsky, A.A. [Amsterdam Univ. (Netherlands). Natuurkundig Lab.; Canfield, P.C.; Olson, C.G. [Iowa State Univ., Ames, IA (United States). Ames Lab.

    1997-02-01

    The electronic structure of both Ce and U heavy fermions appears to consist of extremely narrow temperature independent bands. There is no evidence from ARPES data reported here for a collective phenomenon normally referred to as the Kondo resonance. In uranium compounds a small dispersion of the bands is easily measurable. (orig.).

  20. The electronic structure of heavy fermions: Narrow temperature independent bands

    Energy Technology Data Exchange (ETDEWEB)

    Arko, A.J.; Joyce, J.J.; Smith, J.L.; Andrews, A.B. [and others

    1996-08-01

    The electronic structure of both Ce and U heavy fermions appears to consist of extremely narrow temperature independent bands. There is no evidence from photoemission for a collective phenomenon normally referred to as the Kondo resonance. In uranium compounds a small dispersion of the bands is easily measurable.

  1. A "Narrowing of Inquiry" in American Moral Psychology and Education

    Science.gov (United States)

    Richardson, Michael J.; Slife, Brent D.

    2013-01-01

    We explore the possibility that a priori philosophical commitments continue to result in a narrowing of inquiry in moral psychology and education where theistic worldviews are concerned. Drawing from the theories of Edward L. Thorndike and John Dewey, we examine naturalistic philosophical commitments that influenced the study of moral psychology…

  2. Jakob Müller-Systems and Solutions for Narrow Fabrics

    Institute of Scientific and Technical Information of China (English)

    Wang Ting

    2010-01-01

    @@ Founded in Switzerland in 1887,Jakob Müller AG is one of the world leaders in technology for the manufacture of woven and knitted tapes and webbing,woven labels,technical textiles,woven ropes,printed narrow fabrics,dyeing,make-up and winding machinery.

  3. Reduced dosages of atrazine and narrow rows can provide ...

    African Journals Online (AJOL)

    hope&shola

    2010-11-08

    Nov 8, 2010 ... weeding to keep the crop weed-free and avert yield losses (Mashingaidze and ..... (1998) who reported little benefit in maize to narrow row spacings as a .... analysis of crop rotation effects on weed seed banks. Am. J. Bot. 82:.

  4. The Baldwin effect in the narrow emission lines of AGNs

    CERN Document Server

    Zhang, Kai; Gaskell, C Martin; Dong, Xiao-Bo

    2012-01-01

    The anti-correlations between the equivalent widths of emission lines and the continuum luminosity in AGNs, known as the Baldwin effect are well established for broad lines, but are less well studied for narrow lines. In this paper we explore the Baldwin effect of narrow emission lines over a wide range of ionization levels and critical densities using a large sample of broad-line, radio-quiet AGNs taken from Sloan Digital Sky Survey (SDSS) Data Release 4. These type1 AGNs span three orders of magnitude in continuum luminosity. We show that most narrow lines show a similar Baldwin effect slope of about -0.2 while the significant deviations of the slopes for [NII] 6583, [OII] 3727, [NeV] 3425, and the narrow component of Ha can be explained by the influence of metallicity, star-formation contamination and possibly by difference in the shape of the UV-optical continuum. The slopes do not show any correlation with either the ionization potential or the critical density. We show that a combination of 50% variatio...

  5. QCD Signatures of Narrow Graviton Resonances in Hadron Colliders

    CERN Document Server

    Bijnens, J; Maul, M; Mansson, A; Sjöstrand, Torbjörn

    2001-01-01

    We show that the characteristic p_\\perp spectrum yields valuable information for the test of models for the production of narrow graviton resonances in the TeV range at LHC. Furthermore, it is demonstrated that in those scenarios the parton showering formalism agrees with the prediction of NLO matrix element calculations.

  6. Narrow Near-Threshold Resonance in e+-He+ Scattering

    Institute of Scientific and Technical Information of China (English)

    LIU Min-Min; HAN Hui-Li; GU Si-Hong; SHI Ting-Yun

    2012-01-01

    An independent alternative calculation is performed for narrow near-threshold resonances in the e+-He+ system using the stabilization method in the framework of hyperspherical coordinates (HSSM).A narrow resonance at Er =-0.249995 with width T =1.9 × 10-5,associated with the He2+-Ps(n =1) threshold is confirmed.The resonances around the energies -0.365 and -0.195,predicted by Bhatia and Drachman [Phys.Rev.A 42 (1990)5117] and confirmed by Ho [Phys.Rev.A 53 (1996)3165],do not appear in our calculations.%An independent alternative calculation is performed for narrow near-threshold resonances in the e+-He+ system using the stabilization method in the framework of hyperspherical coordinates (HSSM). A narrow resonance at Er = -0.249995 with width r = 1.9 x 10-5, associated with the He2+-Ps(n = 1) threshold is confirmed. The resonances around the energies -0.365 and -0.195, predicted by Bhatia and Drachman [Phys. Rev. A 42(1990)5117] and confirmed by Ho [Phys. Rev. A 53 (1996) 3165], do not appear in our calculations.

  7. Narrow deeply bound K- and p atomic states

    Science.gov (United States)

    Friedman, E.; Gal, A.

    2000-01-01

    Examples of recently predicted narrow `deeply bound' K- and p atomic states are shown. The saturation of widths for strong absorptive potentials due to the induced repulsion, and the resulting suppression of atomic wave functions within the nucleus, are demonstrated. Production reactions for K- atomic states using φ(1020) decay, and the (p,p) reaction for p atomic states, are discussed.

  8. Characterization and mapping of LanrBo: a locus conferring anthracnose resistance in narrow-leafed lupin (Lupinus angustifolius L.).

    Science.gov (United States)

    Fischer, Kristin; Dieterich, Regine; Nelson, Matthew N; Kamphuis, Lars G; Singh, Karam B; Rotter, Björn; Krezdorn, Nicolas; Winter, Peter; Wehling, Peter; Ruge-Wehling, Brigitte

    2015-10-01

    A novel and highly effective source of anthracnose resistance in narrow-leafed lupin was identified. Resistance was shown to be governed by a single dominant locus. Molecular markers have been developed, which can be used for selecting resistant genotypes in lupin breeding. A screening for anthracnose resistance of a set of plant genetic resources of narrow-leafed lupin (Lupinus angustifolius L.) identified the breeding line Bo7212 as being highly resistant to anthracnose (Colletotrichum lupini). Segregation analysis indicated that the resistance of Bo7212 is inherited by a single dominant locus. The corresponding resistance gene was given the designation LanrBo. Previously published molecular anchor markers allowed us to locate LanrBo on linkage group NLL-11 of narrow-leafed lupin. Using information from RNAseq data obtained with inoculated resistant vs. susceptible lupin entries as well as EST-sequence information from the model genome Lotus japonicus, additional SNP and EST markers linked to LanrBo were derived. A bracket of two LanrBo-flanking markers allows for precise marker-assisted selection of the novel resistance gene in narrow-leafed lupin breeding programs.

  9. Peak-valley-peak pattern of histone modifications delineates active regulatory elements and their directionality

    DEFF Research Database (Denmark)

    Pundhir, Sachin; Bagger, Frederik Otzen; Lauridsen, Felicia Kathrine Bratt

    2016-01-01

    Formation of nucleosome free region (NFR) accompanied by specific histone modifications at flanking nucleosomes is an important prerequisite for enhancer and promoter activity. Due to this process, active regulatory elements often exhibit a distinct shape of histone signal in the form of a peak...

  10. Peak phosphorus - peak food? The need to close the phosphorus cycle.

    Science.gov (United States)

    Rhodes, Christopher J

    2013-01-01

    The peak in the world production of phosphorus has been predicted to occur in 2033, based on world reserves of rock phosphate (URR) reckoned at around 24,000 million tonnes (Mt), with around 18,000 Mt remaining. This figure was reckoned-up to 71,000 Mt, by the USGS, in 2012, but a production maximum during the present century is still highly probable. There are complex issues over what the demand will be for phosphorus in the future, as measured against a rising population (from 7 billion to over 9 billion in 2050), and a greater per capita demand for fertiliser to grow more grain, in part to feed animals and meet a rising demand for meat by a human species that is not merely more populous but more affluent. As a counterweight to this, we may expect that greater efficiencies in the use of phosphorus - including recycling from farms and of human and animal waste - will reduce the per capita demand for phosphate rock. The unseen game changer is peak oil, since phosphate is mined and recovered using machinery powered by liquid fuels refined from crude oil. Hence, peak oil and peak phosphorus might appear as conjoined twins. There is no unequivocal case that we can afford to ignore the likelihood of a supply-demand gap for phosphorus occurring sometime this century, and it would be perilous to do so.

  11. Analysis of the Peak Resistance Frequency Method.

    Science.gov (United States)

    Wang, Boshuo; Weiland, James D

    2016-10-01

    This study analyzes the peak resistance frequency (PRF) method described by Mercanzini et al., a method that can easily extract the tissue resistance from impedance spectroscopy for many neural engineering applications but has no analytical description thus far. Mathematical analyses and computer simulations were used to explore underlying principles, accuracy, and limitations of the PRF method. The mathematical analyses demonstrated that the PRF method has an inherent but correctable deviation dependent on the idealness of the electrode-tissue interface, which is validated by simulations. Further simulations show that both frequency sampling and noise affect the accuracy of the PRF method, and in general, it performs less accurately than least squares methods. However, the PRF method achieves simplicity and reduced measurement and computation time at the expense of accuracy. From the qualitative results, the PRF method can work with reasonable precision and simplicity, although its limitation and the idealness of the electrode-tissue interface involved should be taken into consideration. This paper provides a mathematical foundation for the PRF method and its practical implementation.

  12. Z-peaked excess in goldstini scenarios

    CERN Document Server

    Liew, Seng Pei; Mawatari, Kentarou; Sakurai, Kazuki; Vereecken, Matthias

    2015-01-01

    We study a possible explanation of a 3.0 $\\sigma$ excess recently reported by the ATLAS Collaboration in events with Z-peaked same-flavour opposite-sign lepton pair, jets and large missing transverse momentum in the context of gauge-mediated SUSY breaking with more than one hidden sector, the so-called goldstini scenario. In a certain parameter space, the gluino two-body decay chain $\\tilde g\\to g\\tilde\\chi^0_{1,2}\\to gZ\\tilde G'$ becomes dominant, where $\\tilde\\chi^0_{1,2}$ and $\\tilde G'$ are the Higgsino-like neutralino and the massive pseudo-goldstino, respectively, and gluino pair production can contribute to the signal. We find that a mass spectrum such as $m_{\\tilde g}\\sim 900$ GeV, $m_{\\tilde\\chi^0_{1,2}}\\sim 700$ GeV and $m_{\\tilde G'}\\sim 600$ GeV demonstrates the rate and the distributions of the excess, without conflicting with the stringent constraints from jets plus missing energy analyses and with the CMS constraint on the identical final state.

  13. Z-peaked excess in goldstini scenarios

    Directory of Open Access Journals (Sweden)

    Seng Pei Liew

    2015-11-01

    Full Text Available We study a possible explanation of a 3.0 σ excess recently reported by the ATLAS Collaboration in events with Z-peaked same-flavour opposite-sign lepton pair, jets and large missing transverse momentum in the context of gauge-mediated SUSY breaking with more than one hidden sector, the so-called goldstini scenario. In a certain parameter space, the gluino two-body decay chain g˜→gχ˜1,20→gZG˜′ becomes dominant, where χ˜1,20 and G˜′ are the Higgsino-like neutralino and the massive pseudo-goldstino, respectively, and gluino pair production can contribute to the signal. We find that a mass spectrum such as mg˜∼1000 GeV, mχ˜1,20∼800 GeV and mG˜′∼600 GeV demonstrates the rate and the distributions of the excess, without conflicting with the stringent constraints from jets plus missing energy analyses and with the CMS constraint on the identical final state.

  14. Is There an Advection-dominated Accretion Flow in Radio Galaxies with Double-peaked Balmer Lines?

    Science.gov (United States)

    Nagao, Tohru; Murayama, Takashi; Shioya, Yasuhiro; Taniguchi, Yoshiaki

    2002-03-01

    In order to examine the prediction that the broad-line radio galaxies (BLRGs) with double-peaked Balmer lines harbor an accretion disk characterized by an advection-dominated accretion flow (ADAF) in their nuclei, we investigate narrow emission line flux ratios of the narrow-line regions (NLRs) which are photoionized by nuclear continuum radiation. We compile data from the literature and confirm the pioneering work of Eracleous & Halpern that the BLRGs with the double-peaked Balmer emission exhibit larger flux ratios of both [O I] λ6300/[O III] λ5007 and [O II] λ3727/[O III] λ5007 than the BLRGs without the double-peaked Balmer emission. To examine whether or not these properties are attributed to the difference in the spectral energy distribution (SED) of the ionizing radiation between the BLRGs with and without the double-peaked Balmer emission, we perform photoionization model calculations using two types of input continuum radiation; one has the strong big blue bump which is expected for standard optically thick accretion disks and the other does not exhibit a strong big blue bump as expected for optically thin ADAFs. We find that the data of the BLRGs with the double-peaked Balmer lines are consistent with the models adopting the SED without a strong big blue bump, while the data of the BLRGs without the double-peaked emission lines are well described by the models adopting the SED with a strong big blue bump. On the other hand, the observed differences in the NLR emission are hard to explain by the difference in the contribution of shocks. These results support the idea that the double-peaked Balmer lines arise at an outer region of an accretion disk which is illuminated by an inner, geometrically thick ADAF.

  15. k.p theory of freestanding narrow band gap semiconductor nanowires

    Science.gov (United States)

    Luo, Ning; Liao, Gaohua; Xu, H. Q.

    2016-12-01

    We report on a theoretical study of the electronic structures of freestanding nanowires made from narrow band gap semiconductors GaSb, InSb and InAs. The nanowires are described by the eight-band k.p Hamiltonians and the band structures are computed by means of the finite element method in a mixture basis consisting of linear triangular elements inside the nanowires and constrained Hermite triangular elements near the boundaries. The nanowires with two crystallographic orientations, namely the [001] and [111] orientations, and with different cross-sectional shapes are considered. For each orientation, the nanowires of the three narrow band gap semiconductors are found to show qualitatively similar characteristics in the band structures. However, the nanowires oriented along the two different crystallographic directions are found to show different characteristics in the valence bands. In particular, it is found that all the conduction bands show simple, good parabolic dispersions in both the [001]- and [111]-oriented nanowires, while the top valence bands show double-maximum structures in the [001]-oriented nanowires, but single-maximum structures in the [111]-oriented nanowires. The wave functions and spinor distributions of the band states in these nanowires are also calculated. It is found that significant mixtures of electron and hole states appear in the bands of these narrow band gap semiconductor nanowires. The wave functions exhibit very different distribution patterns in the nanowires oriented along the [001] direction and the nanowires oriented along the [111] direction. It is also shown that single-band effective mass theory could not reproduce all the band state wave functions presented in this work.

  16. Optogenetic excitation of central amygdala amplifies and narrows incentive motivation to pursue one reward above another.

    Science.gov (United States)

    Robinson, Mike J F; Warlow, Shelley M; Berridge, Kent C

    2014-12-10

    Choosing one reward above another is important for achieving adaptive life goals. Yet hijacked into excessive intensity in disorders such as addiction, single-minded pursuit becomes maladaptive. Here, we report that optogenetic channelrhodopsin stimulation of neurons in central nucleus of amygdala (CeA), paired with earning a particular sucrose reward in rats, amplified and narrowed incentive motivation to that single reward target. Therefore, CeA rats chose and intensely pursued only the laser-paired sucrose reward while ignoring an equally good sucrose alternative. In contrast, reward-paired stimulation of basolateral amygdala did not hijack choice. In a separate measure of incentive motivation, CeA stimulation also increased the progressive ratio breakpoint or level of effort exerted to obtain sucrose reward. However, CeA stimulation by itself failed to support behavioral self-stimulation in the absence of any paired external food reward, suggesting that CeA photo-excitation specifically transformed the value of its external reward (rather than adding an internal reinforcement state). Nor did CeA stimulation by itself induce any aversive state that motivated escape. Finally, CeA stimulation also failed to enhance 'liking' reactions elicited by sucrose taste and did not simply increase the general motivation to eat. This pattern suggests that CeA photo-excitation specifically enhances and narrows incentive motivation to pursue an associated external reward at the expense of another comparable reward. Copyright © 2014 the authors 0270-6474/14/3416567-14$15.00/0.

  17. Remote laser generation of narrow-band surface waves through optical fibers.

    Science.gov (United States)

    Di Scalea, F L; Berndt, T P; Spicer, J B; Djordjevic, B B

    1999-01-01

    This paper demonstrates the use of a fiberoptic bundle for flexible, compact, remote, and noncontact laser generation of surface ultrasonic waves in materials. The bundle is able to deliver Nd:YAG pulsed light with a 60% delivery efficiency up to an average energy of 55 mJ/pulse for a pulse duration on the order of 10 ns and a pulse repetition rate of 20 Hz without signs of fiber damage. Details of the bundle construction and surface preparation are given, and pulsed light delivery tests performed with single tapered fibers are discussed. The high-power light delivery capabilities of the bundle are demonstrated for the generation of narrow-band surface waves in a Carbon/PEEK composite laminate by a spatial modulation technique that employs a periodic transmission mask. Single laser pulse ultrasonic tonebursts are clearly detectable using a small aperture piezoelectric transducer while ensuring thermoelastic generation conditions. The theory of narrow-band generation of surface acoustic waves is improved by accounting for the strength nonuniformity of the illumination sources. In addition, the effect of the number of illumination sources on the bandwidth of the generated surface wave is assessed experimentally, and excellent agreement is shown with the theoretical results predicted by the improved model.

  18. Is There an Advection-Dominated Accretion Flow in Radio Galaxies with Double-Peaked Balmer Lines?

    CERN Document Server

    Nagao, T; Shioya, Y; Taniguchi, Y; Nagao, Tohru; Murayama, Takashi; Shioya, Yasuhiro; Taniguchi, Yoshiaki

    2002-01-01

    In order to examine the prediction that the broad-line radio galaxies (BLRGs) with double-peaked Balmer lines harbor an accretion disk characterized by an advection-dominated accretion flow (ADAF) in their nuclei, we investigate narrow emission-line flux ratios of the narrow-line regions which are photoionized by the nuclear continuum radiation. We compile data from the literature and confirm the pioneering work of Eracleous & Halpern that the BLRGs with the double-peaked Balmer emission exhibit larger flux ratios of both [O I]6300/[O III]5007 and [O II]3727/[O III]5007 than the BLRGs without the double-peaked Balmer emission. To examine whether or not these properties are attributed to the difference in the spectral energy distribution (SED) of the ionizing radiation between the BLRGs with and without the double-peaked Balmer emission, we perform photoionization model calculations using two types of input continuum radiation; one has the strong big blue bump which is expected for standard optically-thick...

  19. Clinical and radiographic evaluation of early loaded narrow-diameter implants

    DEFF Research Database (Denmark)

    Maiorana, Carlo; King, Paul; Quaas, Sebastian

    2015-01-01

    OBJECTIVE: To evaluate the clinical reliability of narrow implants placed in a one-stage procedure and early loaded in the upper and lower incisor region. MATERIAL AND METHODS: This is a prospective, single-arm, multicenter study in which patients with missing natural dentition in upper lateral...... and lower incisor positions were enrolled. Eligible implants (OsseoSpeed™ TX 3.0S, DENTSPLY Implants) were of three different lengths and of 3.0 mm in diameter. One-stage surgery was performed and healing abutment connection took place. Placement of the permanent single crown took place after a 6-10 weeks...... healing period. Clinical and radiographic checks were performed at implant placement, loading, and at the 6, 12, 24, and 36 months follow-up visits. RESULTS: A total of 69 subjects with 97 implants have been included in this study. From surgery to 36 months follow-up, 5.6% of the implants showed bone loss...

  20. Increasing 13C CP-MAS NMR resolution using single crystals: application to model octaethyl porphyrins.

    Science.gov (United States)

    Dugar, Sneha; Fu, Riqiang; Dalal, Naresh S

    2012-08-02

    Octaethyl porphyrin (OEP) and its Ni and Zn derivatives are considered as model compounds in biochemical, photophysical, and fossil fuel chemistry. They have thus been investigated by high-resolution solid-state (13)C NMR using powders, but peak assignment has been difficult because of large line widths. Arguing that a significant cause of broadening might be the anisotropic bulk magnetic susceptibility, we utilized single crystals in our (13)C cross-polarization magic angle spinning (CP-MAS) measurements and observed a nearly 2-fold line narrowing. This enhanced resolution enabled us to assign chemical shifts to each carbon for all the three compounds. The new assignments are now in agreement with X-ray structural data and allowed us to probe the motional dynamics of the methyl and methylene carbons of the OEP side chains. It is apparent that the use of single crystals in (13)C CP-MAS measurements has a significantly wider impact than previously thought.

  1. Oscillatory Survival Probability: Analytical, Numerical Study for oscillatory narrow escape and applications to neural network dynamics

    CERN Document Server

    Duc, K Dao; Holcman, D

    2014-01-01

    We study the escape of Brownian motion from the domain of attraction $\\Omega$ of a stable focus with a strong drift. The boundary $\\partial \\Omega$ of $\\Omega$ is an unstable limit cycle of the drift and the focus is very close to the limit cycle. We find a new phenomenon of oscillatory decay of the peaks of the survival probability of the Brownian motion in $\\Omega$. We compute explicitly the complex-valued second eigenvalue $\\lambda_2(\\Omega$) of the Fokker-Planck operator with Dirichlet boundary conditions and show that it is responsible for the peaks. Specifically, we demonstrate that the dominant oscillation frequency equals $1/{\\mathfrak{I}}m\\{\\lambda_2(\\Omega)\\}$ and is independent of the relative noise strength. We apply the analysis to a canonical system and compare the density of exit points on $\\partial \\Omega$ to that obtained from stochastic simulations. We find that this density is concentrated in a small portion of the boundary, thus rendering the exit a narrow escape problem. Unlike the case i...

  2. Persistent Optical Nuclear Spin Narrowing in a Singly Charged InAs Quantum Dot

    Science.gov (United States)

    2012-02-01

    Danon and Y. V. Nazarov, “Nuclear tuning and detuning of the electron spin resonance in a quantum dot: theoretical considera- tion,” Phys. Rev. Lett. 100...nuclear state preparation,” Science 321, 817–821 (2008). 16. I. T. Vink, K. C. Nowack, F. H. L. Koppens, J. Danon , Y. V. Nazarov, and L. M. K. Vandersypen

  3. Selecting Semiconducting Single-Walled Carbon Nanotubes with Narrow Bandgap Naphthalene Diimide-Based Polymers

    NARCIS (Netherlands)

    Salazar-Rios, Jorge Mario; Gomulya, Widianta; Derenskyi, Vladimir; Yang, Jie; Bisri, Satria Zulkarnaen; Chen, Zhihua; Facchetti, Antonio; Loi, Maria Antonietta

    2015-01-01

    Noncovalent functionalization of carbon nanotubes by wrapping them using pi-conjugated polymers is one of the most promising techniques to sort, separate, and purify semiconducting nanotube species for applications in optoelectronic devices. However, wide energy bandgap polymers commonly used in thi

  4. Double peaks reveal rare diplomonad sex.

    Science.gov (United States)

    Andersson, Jan O

    2012-02-01

    Diplomonads, single-celled eukaryotes, are unusual in having two nuclei. Each nucleus contains two copies of the genome and is transcriptionally active. It has long been assumed that diplomonads in general and Giardia intestinalis in particular are asexual. Genomic and population genetic data now challenge that assumption and extensive allelic sequence heterogeneity has been reported in some but not all examined diplomonad lineages. Here it is argued, in contrast to common assumptions, that allelic differences indicate recent sexual events, and isolates that have divided asexually for many generations have lost their allelic variation owing to within-cell recombination. Consequently, directed studies of the allelic sequence heterogeneity in diverse diplomonad lineages are likely to reveal details about the enigmatic diplomonad sexual life cycle.

  5. Decarbonization and the time-delay between peak CO2 emissions and concentrations

    CERN Document Server

    Seshadri, Ashwin K

    2015-01-01

    Carbon-dioxide (CO2) is the main contributor to anthropogenic global warming, and the timing of its peak concentration in the atmosphere is likely to govern the timing of maximum radiative forcing. While dynamics of atmospheric CO2 is governed by multiple time-constants, we idealize this by a single time-constant to consider some of the factors describing the time-delay between peaks in CO2 emissions and concentrations. This time-delay can be understood as the time required to bring CO2 emissions down from its peak to a small value, and is governed by the rate of decarbonizaton of economic activity. This decarbonization rate affects how rapidly emissions decline after having achieved their peak, and a rapid decline in emissions is essential for limiting peak radiative forcing. Long-term mitigation goals for CO2 should therefore consider not only the timing of peak emissions, but also the rate of decarbonization. We discuss implications for mitigation of the fact that the emissions peak corresponds to small bu...

  6. Period effects, cohort effects, and the narrowing gender wage gap.

    Science.gov (United States)

    Campbell, Colin; Pearlman, Jessica

    2013-11-01

    Despite the abundance of sociological research on the gender wage gap, questions remain. In particular, the role of cohorts is under investigated. Using data from the Current Population Survey, we use age-period-cohort analysis to uniquely estimate age, period, and cohort effects on the gender wage gap. The narrowing of the gender wage gap that occurred between 1975 and 2009 is largely due to cohort effects. Since the mid-1990s, the gender wage gap has continued to close absent of period effects. While gains in female wages contributed to declines in the gender wage gap for cohorts born before 1950, for later cohorts the narrowing of the gender wage gap is primarily a result of declines in male wages.

  7. Model of Layered Weld Formation Under Narrow Gap Pulse Welding

    Science.gov (United States)

    Krampit, A. G.

    2016-04-01

    The model parameters of narrow gap pulse welding can be divided into input, internal and output ones. The breadth of gap, that is, clearance breadth between upright edges is one of key parameters securing high quality of a weld joint. The paper presents theoretical outcomes for the model of layered weld formation under narrow gap pulse welding. Based on these studies is developed model of processes, which occur in the weld pool under pulse grove welding. It comprises the scheme of liquid metal motion in the weld pool, scheme of fusion with the side edge and in the bottom part, and the scheme of welding current impulse effect on the structure of a weld joint.

  8. Subwavelength-Sized Narrow-Band Anechoic Waveguide Terminations

    Science.gov (United States)

    Santillán, Arturo; Ćrenlund, Emil; Bozhevolnyi, Sergey I.

    2016-11-01

    We propose and demonstrate the use of a pair of detuned acoustic resonators to efficiently absorb narrow-band sound waves in a terminated waveguide. The suggested configuration is relatively simple and advantageous for usage at low frequencies, since the dimensions of the resonators are very small compared to the wavelength. We present a theoretical description based on lumped parameters to calculate the absorption coefficient, which agrees very well with experimental data. The experimental results verify that the anechoic (reflection approximately -38 dB ) narrow-band (Δ f /f ˜0.1 ) termination with deeply subwavelength (sound absorption in a room, we demonstrate by use of numerical simulations that a given axial resonant excitation in a room can be practically eliminated. Thus, a reduction of approximately 24 dB in the average acoustic energy is achieved in the room when using only four Helmholtz resonators. We also discuss various scenarios of noise control in rooms.

  9. Motional narrowing of broadband absorption of solvatochromic indicator Betaine 30

    Energy Technology Data Exchange (ETDEWEB)

    Renge, Indrek [Institute of Physics, University of Tartu, Riia Street 142, EE51014 Tartu (Estonia)], E-mail: indrek.renge@ut.ee

    2009-05-15

    Temperature dependence of the absorption spectra of Betaine 30 (2,6-diphenyl-4-(2,4,6-triphenylpyridinio)-phenolate, widely known as Reichardt's dye) is compared with that of the broadband spectra of other dyes. The double value of the half-width (2 hwhm) of Betaine 30 absorption band between 10 and 293 K in a polymer decreases by 130{+-}20 cm{sup -1}, from 4220 to 4090 cm{sup -1}. This unprecedented narrowing with increasing temperature is ascribed to hydrogen bond symmetrization due to thermally activated proton tunneling in a pigment-solvent complex. The averaging of charge distribution along the proton coordinate causes motional narrowing of inhomogeneous width.

  10. Bandgap narrowing in moderately to heavily doped silicon

    Science.gov (United States)

    Lanyon, H. P. D.; Tuft, R. A.

    1979-01-01

    A theoretical model of bandgap narrowing in silicon at high doping levels has been developed. The model takes into account the electrostatic energy of interaction between a minority carrier and the majority carriers surrounding it, which reduces the thermal energy necessary for creation of an electron-hole pair. A pair energy similar to the excitonic binding energy of bound electron-hole pairs in insulators is obtained. Theoretical results are in excellent agreement with experimental results in the doping range from 3 times 10 to the 17th to 1.5 times 10 to the 20th/cu cm at room temperature. These results indicate that at high injection levels such as a transistor biased into the conductivity-modulation regime or a solar cell whose surface is established by ion implantation into an oxide layer, the bandgap narrowing is determined by the injected carrier concentration rather than by the doping level.

  11. Coulomb and nuclear excitations of narrow resonances in 17Ne

    Directory of Open Access Journals (Sweden)

    J. Marganiec

    2016-08-01

    Full Text Available New experimental data for dissociation of relativistic 17Ne projectiles incident on targets of lead, carbon, and polyethylene targets at GSI are presented. Special attention is paid to the excitation and decay of narrow resonant states in 17Ne. Distributions of internal energy in the O15+p+p three-body system have been determined together with angular and partial-energy correlations between the decay products in different energy regions. The analysis was done using existing experimental data on 17Ne and its mirror nucleus 17N. The isobaric multiplet mass equation is used for assignment of observed resonances and their spins and parities. A combination of data from the heavy and light targets yielded cross sections and transition probabilities for the Coulomb excitations of the narrow resonant states. The resulting transition probabilities provide information relevant for a better understanding of the 17Ne structure.

  12. Experimental research on flow instability in vertical narrow annuli

    Institute of Scientific and Technical Information of China (English)

    WU Geping; QIU Suizheng; SU Guanghui; JIA Dounan

    2007-01-01

    A narrow annular test section of 1.5mm gap and 1800mm length was designed and manufactured, with good tightness and insulation. Experiments were carried out to investigate characteristics of flow instability of forced-convection in vertical narrow annuli. Using distilled water as work fluid, the experiments were conducted at pressures of 1.0~3.0 MPa, mass flow rates of 3.0~25 kg/h, heating power of 3.0~ 6.5kW and inlet fluid temperature of 20 ℃, 40 ℃ or 60℃. It was found that flow instability occured with fixed inlet condition and heating power when mass flow rate was below a special value. Effects of inlet subcooling, system pressure and mass flow rate on the system behavior were studied and the instability region was given.

  13. A single-solenoid pulsed-magnet system for single-crystal scattering studies.

    Science.gov (United States)

    Islam, Zahirul; Capatina, Dana; Ruff, Jacob P C; Das, Ritesh K; Trakhtenberg, Emil; Nojiri, Hiroyuki; Narumi, Yasuo; Welp, Ulrich; Canfield, Paul C

    2012-03-01

    We present a pulsed-magnet system that enables x-ray single-crystal diffraction in addition to powder and spectroscopic studies with the magnetic field applied on or close to the scattering plane. The apparatus consists of a single large-bore solenoid, cooled by liquid nitrogen. A second independent closed-cycle cryostat is used for cooling samples near liquid helium temperatures. Pulsed magnetic fields close to ~30 T with a zero-to-peak-field rise time of ~2.9 ms are generated by discharging a 40 kJ capacitor bank into the magnet coil. The unique characteristic of this instrument is the preservation of maximum scattering angle (~23.6°) on the entrance and exit sides of the magnet bore by virtue of a novel double-funnel insert. This instrument will facilitate x-ray diffraction and spectroscopic studies that are impractical, if not impossible, to perform using split-pair and narrow-opening solenoid magnets. Furthermore, it offers a practical solution for preserving optical access in future higher-field pulsed magnets.

  14. Impact of peak electricity demand in distribution grids: a stress test

    NARCIS (Netherlands)

    Hoogsteen, Gerwin; Molderink, Albert; Hurink, Johann L.; Smit, Gerardus Johannes Maria; Schuring, Friso; Kootstra, Ben

    2015-01-01

    The number of (hybrid) electric vehicles is growing, leading to a higher demand for electricity in distribution grids. To investigate the effects of the expected peak demand on distribution grids, a stress test with 15 electric vehicles in a single street is conducted and described in this paper.

  15. Search for narrow vector resonances in the Z mass range

    Science.gov (United States)

    Adriani, O.; Aguilar-Benitez, M.; Ahlen, S.; Alcaraz, J.; Aloisio, A.; Alverson, G.; Alviggi, M. G.; Ambrosi, G.; An, Q.; Anderhub, H.; Anderson, A. L.; Andreev, V. P.; Antonov, L.; Antreasyan, D.; Arce, P.; Arefiev, A.; Atamanchuk, A.; Azemoon, T.; Aziz, T.; Baba, P. V. K. S.; Bachmann, S.; Bagnaia, P.; Bakken, J. A.; Baksay, L.; Ball, R. C.; Banerjee, S.; Bao, J.; Barillère, R.; Barone, L.; Baschirotto, A.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Behrens, J.; Bencze, Gy. L.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B. L.; Biasini, M.; Biland, A.; Bilei, G. M.; Bizzarri, R.; Blaising, J. J.; Bobbink, G. J.; Bock, R.; Böhm, A.; Borgia, B.; Bosetti, M.; Bourilkov, D.; Bourquin, M.; Boutigny, D.; Bouwens, B.; Brambilla, E.; Branson, J. G.; Brock, I. C.; Brooks, M.; Bujak, A.; Burger, J. D.; Burger, W. J.; Busenitz, J.; Buytenhuijs, A.; Cai, X. D.; Capell, M.; Caria, M.; Carlino, G.; Cartacci, A. M.; Castello, R.; Cerrada, M.; Cesaroni, F.; Chang, Y. H.; Chaturvedi, U. K.; Chemarin, M.; Chen, A.; Chen, C.; Chen, G. M.; Chen, H. F.; Chen, H. S.; Chen, M.; Chen, W. Y.; Chiefari, G.; Chien, C. Y.; Choi, M. T.; Chung, S.; Civinini, C.; Clare, I.; Clare, R.; Coan, T. E.; Cohn, H. O.; Coignet, G.; Colino, N.; Contin, A.; Cui, X. T.; Cui, X. Y.; Dai, T. S.; D'Alessandro, R.; de Asmundis, R.; Degré, A.; Deiters, K.; Dénes, E.; Denes, P.; DeNotaristefani, F.; Dhina, M.; DiBitonto, D.; Diemoz, M.; Dimitrov, H. R.; Dionisi, C.; Djambazov, L.; Dova, M. T.; Drago, E.; Duchesneau, D.; Duinker, P.; Duran, I.; Easo, S.; El Mamouni, H.; Engler, A.; Eppling, F. J.; Erné, F. C.; Extermann, P.; Fabbretti, R.; Fabre, M.; Falciano, S.; Fan, S. J.; Fackler, O.; Fay, J.; Felcini, M.; Ferguson, T.; Fernandez, D.; Fernandez, G.; Ferroni, F.; Fesefeldt, H.; Fiandrini, E.; Field, J.; Filthaut, F.; Finocchiaro, G.; Fisher, P. H.; Forconi, G.; Foreman, T.; Freudenreich, K.; Friebel, W.; Fukushima, M.; Gailloud, M.; Galaktionov, Yu.; Gallo, E.; Ganguli, S. N.; Garcia-Abia, P.; Gele, D.; Gentile, S.; Goldfarb, S.; Gong, Z. F.; Gonzalez, E.; Gougas, A.; Goujon, D.; Gratta, G.; Gruenewald, M.; Gu, C.; Guanziroli, M.; Guo, J. K.; Gupta, V. K.; Gurtu, A.; Gustafson, H. R.; Gutay, L. J.; Hangarter, K.; Hasan, A.; Hauschildt, D.; He, C. F.; He, J. T.; Hebbeker, T.; Hebert, M.; Herten, G.; Hervé, A.; Hilgers, K.; Hofer, H.; Hoorani, H.; Hu, G.; Hu, G. Q.; Ille, B.; Ilyas, M. M.; Innocente, V.; Janssen, H.; Jezequel, S.; Jin, B. N.; Jones, L. W.; Kasser, A.; Khan, R. A.; Kamyshkov, Yu.; Kapinos, P.; Kapustinsky, J. S.; Karyotakis, Y.; Kaur, M.; Khokhar, S.; Kienzle-Focacci, M. N.; Kim, J. K.; Kim, S. C.; Kim, Y. G.; Kinnison, W. W.; Kirkby, D.; Kirsch, S.; Kittel, W.; Klimentov, A.; König, A. C.; Koffeman, E.; Kornadt, O.; Koutsenko, V.; Koulbardis, A.; Kraemer, R. W.; Kramer, T.; Krastev, V. R.; Krenz, W.; Krivshich, A.; Kuijten, H.; Kumar, K. S.; Kunin, A.; Landi, G.; Lanske, D.; Lanzano, S.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Lee, D. M.; Leedom, I.; Leggett, C.; Le Goff, J. M.; Leiste, R.; Lenti, M.; Leonardi, E.; Leytens, X.; Li, C.; Li, H. T.; Li, P. J.; Liao, J. Y.; Lin, W. T.; Lin, Z. Y.; Linde, F. L.; Lindemann, B.; Lista, L.; Liu, Y.; Lohmann, W.; Longo, E.; Lu, Y. S.; Lubbers, J. M.; Lübelsmeyer, K.; Luci, C.; Luckey, D.; Ludovici, L.; Luminari, L.; Lustermann, W.; Ma, J. M.; Ma, W. G.; MacDermott, M.; Malhotra, P. K.; Malik, R.; Malinin, A.; Maña, C.; Maolinbay, M.; Marchesini, P.; Marion, F.; Marin, A.; Martin, J. P.; Martinez-Laso, L.; Marzano, F.; Massaro, G. G. G.; Mazumdar, K.; McBride, P.; McMahon, T.; McNally, D.; Merk, M.; Merola, L.; Meschini, M.; Metzger, W. J.; Mi, Y.; Mills, G. B.; Mir, Y.; Mirabelli, G.; Mnich, J.; Möller, M.; Monteleoni, B.; Morand, R.; Morganti, S.; Moulai, N. E.; Mount, R.; Müller, S.; Nadtochy, A.; Nagy, E.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Neyer, C.; Niaz, M. A.; Nippe, A.; Nowak, H.; Organtini, G.; Pandoulas, D.; Paoletti, S.; Paolucci, P.; Pascala, G.; Passaleva, G.; Patricelli, S.; Paul, T.; Pauluzzi, M.; Paus, C.; Pauss, F.; Pei, Y. J.; Pensotti, S.; Perret-Gallix, D.; Perrier, J.; Pevsner, A.; Piccolo, D.; Pieri, M.; Piroué, P. A.; Plasil, F.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Postema, H.; Qi, Z. D.; Qian, J. M.; Qureshi, K. N.; Raghavan, R.; Rahal-Callot, G.; Rancoita, P. G.; Rattaggi, M.; Raven, G.; Razis, P.; Read, K.; Ren, D.; Ren, Z.; Rescigno, M.; Reucroft, S.; Ricker, A.; Riemann, S.; Riemers, B. C.; Riles, K.; Rind, O.; Rizvi, H. A.; Rodriguez, F. J.; Roe, B. P.; Röhner, M.; Röhner, S.; Romero, L.; Rose, J.; Rosier-Lees, S.; Rosmalen, R.; Rosselet, Ph.; van Rossum, W.; Roth, S.; Rubbia, A.; Rubio, J. A.; Rykaczewski, H.; Sachwitz, M.; Salicio, J.; Salicio, J. M.; Sanders, G. S.; Santocchia, A.; Sarakinos, M. S.; Sartorelli, G.; Sassowsky, M.; Sauvage, G.; Schäfer, C.; Schegelsky, V.; Schmitz, D.; Schmitz, P.; Schneegans, M.; Schopper, H.; Schotanus, D. J.; Shotkin, S.; Schreiber, H. J.; Shukla, J.; Schulte, R.; Schulte, S.; Schultze, K.; Schwenke, J.; Schwering, G.; Sciacca, C.; Scott, I.; Sehgal, R.; Seiler, P. G.; Sens, J. C.; Servoli, L.; Sheer, I.; Shen, D. Z.; Shevchenko, S.; Shi, X. R.; Shumilov, E.; Shoutko, V.; Son, D.; Sopczak, A.; Spartiotis, C.; Spickermann, T.; Spillantini, P.; Starosta, R.; Steuer, M.; Stickland, D. P.; Sticozzi, F.; Stone, H.; Strauch, K.; Stringfellow, B. C.; Sudhakar, K.; Sultanov, G.; Sun, L. Z.; Suter, H.; Swain, J. D.; Syed, A. A.; Tang, X. W.; Taylor, L.; Terzi, G.; Ting, Samuel C. C.; Ting, S. M.; Tonutti, M.; Tonwar, S. C.; Tóth, J.; Tsaregorodtsev, A.; Tsipolitis, G.; Tully, C.; Tung, K. L.; Ulbricht, J.; Urbán, L.; Uwer, U.; Valente, E.; Van de Walle, R. T.; Vetlitsky, I.; Viertel, G.; Vikas, P.; Vikas, U.; Vivargent, M.; Vogel, H.; Vogt, H.; Vorobiev, I.; Vorobyov, A. A.; Vuilleumier, L.; Wadhwa, M.; Wallraff, W.; Wang, C.; Wang, C. R.; Wang, G. H.; Wang, X. L.; Wang, Y. F.; Wang, Z. M.; Weber, A.; Weber, J.; Weill, R.; Wenaus, T. J.; Wenninger, J.; White, M.; Willmott, C.; Wittgenstein, F.; Wright, D.; Wu, S. X.; Wynhoff, S.; Wysłouch, B.; Xie, Y. Y.; Xu, J. G.; Xu, Z. Z.; Xue, Z. L.; Yan, D. S.; Yang, B. Z.; Yang, C. G.; Yang, G.; Ye, C. H.; Ye, J. B.; Ye, Q.; Yeh, S. C.; Yin, Z. W.; You, J. M.; Yunus, N.; Yzerman, M.; Zaccardelli, C.; Zemp, P.; Zeng, M.; Zeng, Y.; Zhang, D. H.; Zhang, Z. P.; Zhou, B.; Zhou, G. J.; Zhou, J. F.; Zhu, R. Y.; Zichichi, A.; van der Zwaan, B. C. C.; L3 Collaboration

    1993-08-01

    The hadronic lineshape of the Z has been analyzed for evidence of signals of new, narrow vector resonances in the Z-mass range. The production rate of such resonances would be enhanced due to mixing with the Z. No evidence for new states is found, and it is thus possible to exclude, at the 95% confidence level, a quarkonium state in the mass range from 87.7 to 94.7 GeV.

  16. Whispering Gallery Mode Resonator Stabilized Narrow Linewidth Fiber Loop Laser

    CERN Document Server

    Sprenger, B; Wang, L J; 10.1364/OL.34.003370

    2012-01-01

    We demonstrate a narrow line, fiber loop laser using Erbium-doped fiber as the gain material, stabilized by using a microsphere as a transmissive frequency selective element. Stable lasing with a linewidth of 170 kHz is observed, limited by the experimental spectral resolution. A linear increase in output power and a red-shift of the lasing mode were also observed with increasing pump power. Its potential application is also discussed.

  17. Analysis of ultra-narrow ferromagnetic domain walls

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, Catherine; Paul, David

    2012-01-10

    New materials with high magnetic anisotropy will have domains separated by ultra-narrow ferromagnetic walls with widths on the order of a few unit cells, approaching the limit where the elastic continuum approximation often used in micromagnetic simulations is accurate. The limits of this approximation are explored, and the static and dynamic interactions with intrinsic crystalline defects and external driving elds are modeled. The results developed here will be important when considering the stability of ultra-high-density storage media.

  18. Three-Prong Distribution of Massive Narrow QCD Jets

    CERN Document Server

    Field, Matan; Kosower, David A; Mannelli, Lorenzo; Perez, Gilad

    2013-01-01

    We study the planar-flow distributions of narrow, highly boosted, massive QCD jets. Using the factorization properties of QCD in the collinear limit, we compute the planar-flow jet function from the one-to-three splitting function at tree-level. We derive the leading-log behavior of the jet function analytically. We also compare our semi-analytic jet function with parton-shower predictions using various generators.

  19. Cervical spinal canal narrowing and cervical neurologi-cal injuries

    Directory of Open Access Journals (Sweden)

    ZHANG Ling

    2012-04-01

    Full Text Available 【Abstract】Cervical spinal canal narrowing can lead to injury of the spinal cord and neurological symptoms in-cluding neck pain, headache, weakness and parasthesisas. According to previous and recent clinical researches, we investigated the geometric parameters of normal cervical spinal canal including the sagittal and transverse diameters as well as Torg ratio. The mean sagittal diameter of cervical spinal canal at C 1 to C 7 ranges from 15.33 mm to 20.46 mm, the mean transverse diameter at the same levels ranges from 24.45 mm to 27.00 mm and the mean value of Torg ratio is 0.96. With respect to narrow cervical spinal canal, the following charaterstics are found: firstly, extension of the cervical spine results in statistically significant stenosis as compared with the flexed or neutral positions; secondly, females sustain cervical spinal canal narrowing more easily than males; finally, the consistent narrowest cervical canal level is at C 4 for all ethnicity, but there is a slight variation in the sagittal diameter of cervical spinal stenosis (≤14 mm in Whites, ≤ 12 mm in Japanese, ≤13.7 mm in Chinese. Narrow sagittal cervical canal diameter brings about an increased risk of neurological injuries in traumatic, degenerative and inflam-matory conditions and is related with extension of cervical spine, gender, as well as ethnicity. It is hoped that this re-view will be helpful in diagnosing spinal cord and neuro-logical injuries with the geometric parameters of cervical spine in the future. Key words: Spinal cord injuries; Spinal stenosis; Trauma, nervous system

  20. Cervical spinal canal narrowing and cervical neurological injuries

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ling; CHEN Hai-bin; WANG Yi; ZHANG Li-ying; LIU Jing-cheng; WANG Zheng-guo

    2012-01-01

    Cervical spinal canal narrowing can lead to injury of the spinal cord and neurological symptoms including neck pain,headache,weakness and parasthesisas.According to previous and recent clinical researches,we investigated the geometric parameters of normal cervical spinal canal including the sagittal and transverse diameters as well as Torg ratio.The mean sagittal diameter of cervical spinal canal at C1 to C7 ranges from 15.33 mm to 20.46 mm,the mean transverse diameter at the same levels ranges from 24.45 mm to 27.00 mm and the mean value of Torg ratio is 0.96.With respect to narrow cervical spinal canal,the following charaterstics are found:firstly,extension of the cervical spine results in statistically significant stenosis as compared with the flexed or neutral positions; secondly,females sustain cervical spinal canal narrowing more easily than males;finally,the consistent narrowest cervical canal level is at C4 for all ethnicity,but there is a slight variation in the sagittal diameter of cervical spinal stenosis(≤ 14 mm in Whites,≤12 mm in Japanese,≤ 13.7 mm in Chinese).Narrow sagittal cervical canal diameter brings about an increased risk of neurological injuries in traumatic,degenerative and inflammatory conditions and is related with extension of cervical spine,gender,as well as ethnicity.It is hoped that this review will be helpful in diagnosing spinal cord and neurological injuries with the geometric parameters of cervical spine in the future.

  1. A numerical study of natural convection in a narrow annulus

    Energy Technology Data Exchange (ETDEWEB)

    Sahai, V.

    1991-12-01

    Various numerical models were used to predict the natural convection of a solidifying liquid metal in a narrow annulus. Previous work in this area do not consider the temperature variation that exists in the fluid and the resulting heat conduction in the solid mold material. The finite element fluid dynamics code FIDAP was sued to solve these models. The results indicate that the natural convective effects are small. 6 refs.

  2. A numerical study of natural convection in a narrow annulus

    Science.gov (United States)

    Sahai, V.

    1991-12-01

    Various numerical models were used to predict the natural convection of a solidifying liquid metal in a narrow annulus. Previous work in this area does not consider the temperature variation that exists in the fluid and the resulting heat conduction in the solid mold material. The finite element fluid dynamics code FIDAP was used to solve these models. The results indicate that the natural convective effects are small.

  3. Critical Heat Flux in Inclined Rectangular Narrow Gaps

    Energy Technology Data Exchange (ETDEWEB)

    Jeong J. Kim; Yong H. Kim; Seong J. Kim; Sang W. Noh; Kune Y. Suh; Joy L. Rempe; Fan-Bill Cheung; Sang B. Kim

    2004-06-01

    In light of the TMI-2 accident, in which the reactor vessel lower head survived the attack by molten core material, the in-vessel retention strategy was suggested to benefit from cooling the debris through a gap between the lower head and the core material. The GAMMA 1D (Gap Apparatus Mitigating Melt Attack One Dimensional) tests were conducted to investigate the critical heat flux (CHF) in narrow gaps with varying surface orientations. The CHF in an inclined gap, especially in case of the downward-facing narrow gap, is dictated by bubble behavior because the departing bubbles are squeezed. The orientation angle affects the bubble layer and escape of the bubbles from the narrow gap. The test parameters include gap sizes of 1, 2, 5 and 10 mm and the open periphery, and the orientation angles range from the fully downward-facing (180o) to the vertical (90o) position. The 15 ×35 mm copper test section was electrically heated by the thin film resistor on the back. The heater assembly was installed to the tip of the rotating arm in the heated water pool at the atmospheric pressure. The bubble behavior was photographed utilizing a high-speed camera through the Pyrex glass spacer. It was observed that the CHF decreased as the surface inclination angle increased and as the gap size decreased in most of the cases. However, the opposing results were obtained at certain surface orientations and gap sizes. Transition angles, at which the CHF changed in a rapid slope, were also detected, which is consistent with the existing literature. A semi-empirical CHF correlation was developed for the inclined narrow rectangular channels through dimensional analysis. The correlation provides with best-estimate CHF values for realistically assessing the thermal margin to failure of the lower head during a severe accident involving relocation of the core material.

  4. [Ventricular tachycardia with narrow QRS complex after cardiac surgery].

    Science.gov (United States)

    Nagajewski, Adam; Morskaya, Marina; Zembala, Marian

    2010-04-01

    We present new-onset sustained monomorphic ventricular tachycardia with relatively narrow QRS (width of QRS feminine 120 ms) in the recovery period after aortic valve replacement and surgical revascularisation in a patient with a prior inferior wall myocardial infarction. Ventricular tachycardia probably originating from the left-side His-Purkinje system and mimicking idiopathic posterior fascicular tachycardia was diagnosed. Placement of a bypass graft across occluded artery supplying an infarct zone was a potential trigger of this arrhythmia.

  5. Voicing Strategies Employed in Narrow Listening Among Iranian Female Freshmen

    OpenAIRE

    Mohsen Shahrokhi; Farinaz Shirani Bidabadi; Hamidah Yamat

    2013-01-01

    This study discusses the findings of a qualitative study on the strategies used by Iranian female freshmen in narrow listening. The data collected through semi-structured interview with 12 female freshmen (four learners as  advanced, four as intermediate and four as low) chosen purposefully based on their scores in the Oxford Placement Test administered. Six out of 12 freshmen were identified for the think-aloud protocol to draw out the strategies they used. The data collected were analyzed u...

  6. The Argument for a Narrow Conception of 'Religious Autonomy'

    DEFF Research Database (Denmark)

    Christoffersen, Lisbet

    2015-01-01

    This article argues for a both horizontal and vertical narrow concept of collective freedom of Religion. The most recent ECtHR judgments as well as the US Supreme Court Hosanna-Tabor case leads theory to establish religious autonomy based on parallel legal roders. Nordic theory has been based...... on lack of acknowledgement of Canon Law, which is no longer possible. A future path might be to accept overlapping normative orders, however with secular courts as the final institutions....

  7. Whittier Narrows Flood Control Basin Historic Resources Survey,

    Science.gov (United States)

    1976-10-15

    MAKING SURVEY 2.0 General In making this survey of the Whittier Narrows and Los Angeles River-Rio Hondo historic re- sources , the investigators have...various protective facilities. Washington provided the funds with the stipulation that the work be done unqr the direction of the United States Army Corps...testIfying to southern California’s historic penchant for unique town building ("Venice of America") and amusement park operation ( Disneyland ). Finally

  8. Multi-chromatic narrow-energy-spread electron bunches from laser wakefield acceleration with dual color lasers

    CERN Document Server

    Zeng, Ming; Yu, Lu-Le; Mori, Warren B; Sheng, Zheng-Ming; Hidding, Bernhard; Jaroszynski, Dino; Zhang, Jie

    2014-01-01

    A method based on laser wakefield acceleration is proposed that can generate electron bunches with an energy spectrum containing multiple spikes each with very narrow energy spread. The method is demonstrated through multi-dimensional particle-in-cell simulations. The beating of bichromatic short pulse laser fields allows controlled ionization injection of electrons into an accelerating bucket. Due to the different dispersion of the two color pulses co-propagating in the background plasma, the peak amplitude of the combined laser field oscillates during the propagation. Ionization injection occurs when the peak amplitude exceeds an ionization threshold. The threshold is exceeded for limited durations at different propagation distances. Electrons from each injection duration produce separate electron bunches. This combined with an oscillating bubble in multi-dimensions produces an energy spectrum with multi-chromatic spikes, where each spike has an energy spread less than 1%. Such electron bunches could be use...

  9. Joint Space Narrowing in Patients With Pisotriquetral Osteoarthritis.

    Science.gov (United States)

    Ten Berg, Paul W L; Heeg, Erik; Strackee, Simon D; Streekstra, Geert J

    2017-09-01

    Patients with suspected pisotriquetral osteoarthritis may show joint space narrowing. However, the extent of joint space narrowing and its deviation from the joint space width (JSW) in normal anatomy is unknown. In this pathoanatomic study, we therefore compared the JSW in the pisotriquetral joint between osteoarthritic patient wrists and healthy wrists. We reviewed preoperative computed tomography (CT) scans of 8 wrists of patients with ulnar-sided wrist pain who underwent a pisiformectomy with confirmed pisotriquetral osteoarthritis at surgery. We also reviewed CT scans of 20 normal wrists from healthy volunteers serving as control group. Three-dimensional CT models of the pisiform and triquetrum were obtained from both affected and normal wrists, after which the minimum JSW was calculated in an automated fashion. In the patient group, the median (interquartile range) of the minimum JSW was 0.1 mm (0.0-0.2), and in the control group, 0.8 mm (0.3-0.9) ( P = .007). We showed that the pisotriquetral joint space in osteoarthritic patient wrists was significantly narrowed compared with healthy wrists. These results suggest that JSW evaluation has a potential diagnostic value in the work-up of patients with suspected pisotriquetral osteoarthritis. This is an interesting area for future clinical research, especially because no gold standard for diagnosing pisotriquetral osteoarthritis has been established yet.

  10. The Structure of Narrow-Line Region in LINERs

    Institute of Scientific and Technical Information of China (English)

    Hai-Feng Dai; Ting-Gui Wang

    2008-01-01

    Low-ionization nuclear emission regions (LINERs) are present in a large fraction of local galaxies, while their connection to the more luminous active galactic nuclei (AGN) remains elusive. We analyze the narrow band images obtained by the Hubble Space Telescope (HST) in Hα+[NⅡ] and/or [OⅢ] band for 23 LINERs and low luminosity Seyfert galaxies in the sample of the Palomar Optical Spectroscopic Survey of nearby galaxies in an attempt to resolve the structure of Narrow Emission Line Regions (NLRs) of these objects. In all cases, NLRs are well resolved and their morphology differs from object to object. Clumps, linear structure, spiral arms or a ring are detected in a large fraction of the objects, while there is no significant difference between Seyfert galaxies and LINERs. We find that the NLR size and the narrow line luminosity are strongly correlated for both LINERs and low luminosity Seyfert galaxies, and that the size of Hα+[NⅡ] emission line region scales with Hα luminosity as RNLR∞L0.4±0.06Hα, consistent with an extension of the NLR size-luminosity relation defined for luminous Seyfert galaxies and quasars, to two orders of magnitude lower in luminosity and to lower activity levels. Our results suggest that NLRs in LINERs are similar to those of Seyfert galaxies, and they are powered by the central active galactic nucleus.

  11. Study on dryout point in vertical narrow annuli

    Institute of Scientific and Technical Information of China (English)

    TIAN Wen-Xi; AYE Myint; QIU Sui-Zheng; JIA Dou-Nan

    2005-01-01

    Prediction of dryout point is experimentally investigated with deionized water upflowing through narrow annular channel with 1.0 mm and 1.5 mm gap respectively. The annulus with narrow gap is bilaterally heated by AC current power supply. The experimental conditions covered a range of pressure from 0.8 to 3.5 MPa, mass flux of 26.6 to 68.8 kg·m-2·s-1 and wall heat flux of 5 to 50 kW·m-2. The location of dryout is obtained by observing a sudden rise in surface temperature. Kutateladze correlation is cited and modified to predict the location of dryout and proved to be not a proper one. Considering in detail the effects of geometry of annuli, pressure, mass flux and heat flux on dryout, an empirical correction is finally developed to predict dryout point in narrow annular gap under low flow condition, which has a good agreement with experimental data.

  12. A line-broadening analysis model for the microstructural characterization of nanocrystalline materials from asymmetric x-ray diffraction peaks.

    Science.gov (United States)

    Pantoja-Cortés, Juan; Sánchez-Bajo, Florentino; Ortiz, Angel L

    2012-05-30

    Nanograin sizes and crystal lattice microstrains in nanocrystalline materials are typically evaluated from the broadening of their x-ray diffraction (XRD) peaks under the assumption of symmetrical diffraction profiles. Since this assumption is not entirely satisfactory, we formulate a line-broadening analysis model of a single peak that considers explicitly the XRD peak asymmetry. The model is a generalization of the variance method in which the shape of the XRD peaks is idealized through asymmetrical split pseudo-Voigt functions. The model is validated on two nanocrystalline powders.

  13. An Examination of the Multi-Peaked Analytically Extended Function for Approximation of Lightning Channel-Base Currents

    CERN Document Server

    Lundengård, Karl; Javor, Vesna; Silvestrov, Sergei

    2016-01-01

    A multi-peaked version of the analytically extended function (AEF) intended for approximation of multi-peaked lightning current wave-forms will be presented along with some of its basic properties. A general framework for estimating the parameters of the AEF using the Marquardt least-squares method (MLSM) for a waveform with an arbitrary (finite) number of peaks as well as a given charge trans-fer and specific energy will also be described. This framework is used to find parameters for some common single-peak wave-forms and some advantages and disadvantages of the approach will be discussed.

  14. SINGLE-PULSE RADIO OBSERVATIONS OF THE GALACTIC CENTER MAGNETAR PSR J1745–2900

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Zhen; Shen, Zhi-Qiang; Wu, Ya-Jun; Zhao, Rong-Bing; Fan, Qing-Yuan; Hong, Xiao-Yu; Jiang, Dong-Rong; Li, Bin; Liang, Shi-Guang; Ling, Quan-Bao; Liu, Qing-Hui; Qian, Zhi-Han; Zhang, Xiu-Zhong; Zhong, Wei-Ye; Ye, Shu-Hua [Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030 (China); Wu, Xin-Ji [Department of Astronomy, Peking University, Beijing 100871 (China); Manchester, R. N. [CSIRO Astronomy and Space Science, P.O. Box 76, Epping, NSW 1710 (Australia); Weltevrede, P. [Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); Yuan, Jian-Ping [Key Laboratory of Radio Astronomy, Chinese Academy of Sciences (China); Lee, Ke-Jia, E-mail: yanzhen@shao.ac.cn [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China)

    2015-11-20

    In this paper, we report radio observations of the Galactic Center magnetar PSR J1745–2900 at six epochs between 2014 June and October. These observations were carried out using the new Shanghai Tian Ma Radio Telescope at a frequency of 8.6 GHz. Both the flux density and integrated profile of PSR J1745–2900 show dramatic changes from epoch to epoch, showing that the pulsar was in its “erratic” phase. On MJD 56836, the flux density of this magnetar was about 8.7 mJy, which was 10 times larger than that reported at the time of discovery, enabling a single-pulse analysis. The emission is dominated by narrow “spiky” pulses that follow a log-normal distribution in peak flux density. From 1913 pulses, we detected 53 pulses whose peak flux densities are 10 times greater than that of the integrated profile. They are concentrated in pulse phase at the peaks of the integrated profile. The pulse widths at the 50% level of these bright pulses were between 0.°2 and 0.°9, much narrower than that of the integrated profile (∼12°). The observed pulse widths may be limited by interstellar scattering. No clear correlation was found between the widths and peak flux density of these pulses and no evidence was found for subpulse drifting. Relatively strong spiky pulses are also detected in the other five epochs of observation, showing the same properties as those detected in MJD 56836. These strong spiky pulses cannot be classified as “giant” pulses but are more closely related to normal pulse emission.

  15. Estimation of peak discharges of historical floods

    Directory of Open Access Journals (Sweden)

    J. Herget

    2014-05-01

    Full Text Available There is no doubt, that the hazard assessment of future floods especially under consideration of the recent environmental change can be significantly improved by the consideration of historic flood events. While flood frequency inventories on local, regional and even European scale are already developed and published, the estimation of their magnitudes indicated by discharges is still challenging. Such data are required due to significant human impact on river channels and floodplains though historic flood levels cannot be related to recent ones or recent discharges. Based on own experiences from single local key studies the general outline of an approach to estimate the discharge of the previous flood based on handed down flood level and topographic data is presented. The model for one-dimensional steady flow is based on the empirical Manning equation for the mean flow velocity. Background and potential sources of information, acceptable simplifications and data transformation for each element of the model-equation are explained and discussed. Preliminary experiences on the accuracy of ±10% are documented and potential approaches for the validation of individual estimations given. A brief discussion on benefits and limitations including a generalized statement on alternative approaches closes the review presentation of the approach.

  16. Astrometric and Photometric Accuracy of the 1.3 m Robotically Controlled Telescope on Kitt Peak

    Science.gov (United States)

    McGruder, Charles H.; Carini, M. T.; Engle, S. G.; Gelderman, R.; Guinan, E. F.; Laney, D.; Strolger, L.; Treffers, R. R.; Walter, D. K.

    2014-01-01

    The 1.3 m (50 inch) telescope on Kitt Peak has been refurbished and provided with an autonomous scheduler. It is operated by The Robotically Controlled Telescope (RCT) consortium whose members are: South Carolina State, Villanova and Western Kentucky Universities. The facility possesses 5 board (UBVRI) and 11 narrow-band filters. Attached to the RCT camera is a 2048 x 2048 SITe SI-424A back-illuminated CCD with 24 micrometer pixels. We used over 7,000 star measurements from 37, 198s R-images to compute the astrometric and photometric accuracy. The difference of the J2000 coordinates computed from the RCT images and the J2000 Nomad catalog coordinate values in right ascension peaks at 0.058”, while the declination peaks at -0.125”. We obtained these astrometric results using the simplest assumptions: linear relationship between standard coordinates and measured coordinates, no color or magnitude dependency and no differential refraction (all images taken in the zenith). We express the photometric accuracy in the following manner: The Signal-to-Noise-Ratio as a function of apparent magnitude shows that the RCT is not noise dominated at m < 20 magnitude.

  17. Peak-power-point monitor for solar panel

    Science.gov (United States)

    Schloss, A. I.

    1972-01-01

    Attempt was made to determine solar cell panel peak power capability without disrupting power flow from panel. Separate solar cell strings were switched from panel circuits, and increasingly larger loads were added rapidly until peak power points were transversed. String wattage output was recorded and all stored string measurements summed together indicate peak power point in panel.

  18. LSQ14bdq: A Type Ic super-luminous supernova with a double-peaked light curve

    CERN Document Server

    Nicholl, M; Jerkstrand, A; Sim, S A; Inserra, C; Anderson, J P; Baltay, C; Benetti, S; Chambers, K; Chen, T -W; Elias-Rosa, N; Feindt, U; Flewelling, H A; Fraser, M; Gal-Yam, A; Galbany, L; Huber, M E; Kangas, T; Kankare, E; Kotak, R; Krühler, T; Maguire, K; McKinnon, R; Rabinowitz, D; Rostami, S; Schulze, S; Smith, K W; Sullivan, M; Tonry, J L; Valenti, S; Young, D R

    2015-01-01

    We present data for LSQ14bdq, a hydrogen-poor super-luminous supernova (SLSN) discovered by the La Silla QUEST survey and classified by the Public ESO Spectroscopic Survey of Transient Objects. The spectrum and light curve are very similar to slow-declining SLSNe such as PTF12dam. However, detections within $\\sim1$ day after explosion show a bright and relatively fast initial peak, lasting for $\\sim15$ days, prior to the usual slow rise to maximum light. The broader, main peak can be fit with either central engine or circumstellar interaction models. We discuss the implications of the precursor peak in the context of these models. It is too bright and narrow to be explained as a normal \\Ni-powered SN, and we suggest that interaction models may struggle to fit the precursor and main peak simultaneously. We propose that the initial peak is from the post-shock cooling of an extended stellar envelope, and reheating by a central engine drives the second peak. In this picture, we show that an explosion energy of $\\...

  19. Detection and quantitative characterization of artificial extra peaks following polymerase chain reaction amplification of 14 short tandem repeat systems used in forensic investigations

    DEFF Research Database (Denmark)

    Meldgaard, Michael; Morling, N

    1997-01-01

    Detection on automated DNA sequencers of polymerase chain reaction (PCR) products of tetra- and penta-nucleotide short tandem repeat (STR) loci frequently reveals one or more extra peaks along with the true, major allele peak. The most frequent extra peak pattern is a single smaller peak which......, while Hum-TH01, HumCD4, and D12S391 were virtually unaffected by low-stringency conditions. Replacement of the Taq DNA polymerase with DNA polymerases with lower processivity resulted in higher levels of extra peaks. Our results support the hypothesis that extra peaks are produced due to slipped...

  20. Characterization and Fine Mapping of a Novel Rice Narrow Leaf Mutant nal9

    Institute of Scientific and Technical Information of China (English)

    Wei Li; Wenzhen Liu; Chao Wu; Guocheng Hu; Li Xing; Wenjing Qian; Huamin Si; Zongxiu Sun; Xingchun Wang; Yaping Fu

    2013-01-01

    A narrow leaf mutant was isolated from transgenic rice (Oryza sativa L.) lines carrying a T-DNA insertion. The mutant is characterized by narrow leaves during its whole growth period, and was named nal9 (narrow leaf 9). The mutant also has other phenotypes, such as light green leaves at the seedling stage, reduced plant height, a small panicle and increased tillering. Genetic analysis revealed that the mutation is controlled by a single recessive gene. A hygromycin resistance assay showed that the mutation was not caused by T-DNA insertion, so a map-based cloning strategy was employed to isolate the nal9 gene. The mutant individuals from the F2 generations of a cross between the nal9 mutant and Longtepu were used for mapping. With 24 F2 mutants, the nal9 gene was preliminarily mapped near the marker RM156 on the chromosome 3. New INDEL markers were then designed based on the sequence differences between japonica and indica at the region near RM156. The nal9 gene was finally located in a 69.3 kb region between the markers V239B and V239G within BAC OJ1212_C05 by chromosome walking. Sequence and expression analysis showed that an ATP-dependent Clp protease proteolytic subunit gene (ClpP) was most likely to be the nal9 gene. Furthermore, the nal9 mutation was rescued by transformation of the ClpP cDNA driven by the 35S promoter. Accordingly, the ClpP gene was identified as the NAL9 gene. Our results provide a basis for functional studies of NAL9 in future work.

  1. Economic and safety analysis of unconventional peak regulation on power unit of peak shifting start-stop

    Science.gov (United States)

    Cao, X.; Zhao, J. F.; Duan, X. Q.; Jin, Y. A.

    2017-01-01

    Tthe capacity difference of peak regulation between the power gird and the actual demand has become a serious problem considering the growth in the difference between electricity supply and demand. Therefore, peak regulation of power grid needs to be deeply studied. Unconventional peak regulation on unit of peak shifting start-stop is a way that can broaden the range of power regulation, as well as benefit safe operation of the power grid. However, it requires frequent and fast unit start-stop, complex operation, and more staff labor. By carrying out unconventional thermal power unit load test, the start-stop mode of peak auxiliary equipment is studied in this paper, indicating that it has a positive effect on safety and economic of load-peaking operation. The best working conditions of the peak units is found by analysing consumption cost, safety specifications, and life lost of the start-stop peak regulation mode.

  2. New Insights on the Burstein-Moss Shift and Band Gap Narrowing in Indium-Doped Zinc Oxide Thin Films.

    Directory of Open Access Journals (Sweden)

    K G Saw

    Full Text Available The Burstein-Moss shift and band gap narrowing of sputtered indium-doped zinc oxide (IZO thin films are investigated as a function of carrier concentrations. The optical band gap shifts below the carrier concentration of 5.61 × 1019 cm-3 are well-described by the Burstein-Moss model. For carrier concentrations higher than 8.71 × 1019 cm-3 the shift decreases, indicating that band gap narrowing mechanisms are increasingly significant and are competing with the Burstein-Moss effect. The incorporation of In causes the resistivity to decrease three orders of magnitude. As the mean-free path of carriers is less than the crystallite size, the resistivity is probably affected by ionized impurities as well as defect scattering mechanisms, but not grain boundary scattering. The c lattice constant as well as film stress is observed to increase in stages with increasing carrier concentration. The asymmetric XPS Zn 2p3/2 peak in the film with the highest carrier concentration of 7.02 × 1020 cm-3 suggests the presence of stacking defects in the ZnO lattice. The Raman peak at 274 cm-1 is attributed to lattice defects introduced by In dopants.

  3. New Insights on the Burstein-Moss Shift and Band Gap Narrowing in Indium-Doped Zinc Oxide Thin Films.

    Science.gov (United States)

    Saw, K G; Aznan, N M; Yam, F K; Ng, S S; Pung, S Y

    2015-01-01

    The Burstein-Moss shift and band gap narrowing of sputtered indium-doped zinc oxide (IZO) thin films are investigated as a function of carrier concentrations. The optical band gap shifts below the carrier concentration of 5.61 × 1019 cm-3 are well-described by the Burstein-Moss model. For carrier concentrations higher than 8.71 × 1019 cm-3 the shift decreases, indicating that band gap narrowing mechanisms are increasingly significant and are competing with the Burstein-Moss effect. The incorporation of In causes the resistivity to decrease three orders of magnitude. As the mean-free path of carriers is less than the crystallite size, the resistivity is probably affected by ionized impurities as well as defect scattering mechanisms, but not grain boundary scattering. The c lattice constant as well as film stress is observed to increase in stages with increasing carrier concentration. The asymmetric XPS Zn 2p3/2 peak in the film with the highest carrier concentration of 7.02 × 1020 cm-3 suggests the presence of stacking defects in the ZnO lattice. The Raman peak at 274 cm-1 is attributed to lattice defects introduced by In dopants.

  4. The formation of peak rings in large impact craters.

    Science.gov (United States)

    Morgan, Joanna V; Gulick, Sean P S; Bralower, Timothy; Chenot, Elise; Christeson, Gail; Claeys, Philippe; Cockell, Charles; Collins, Gareth S; Coolen, Marco J L; Ferrière, Ludovic; Gebhardt, Catalina; Goto, Kazuhisa; Jones, Heather; Kring, David A; Le Ber, Erwan; Lofi, Johanna; Long, Xiao; Lowery, Christopher; Mellett, Claire; Ocampo-Torres, Rubén; Osinski, Gordon R; Perez-Cruz, Ligia; Pickersgill, Annemarie; Poelchau, Michael; Rae, Auriol; Rasmussen, Cornelia; Rebolledo-Vieyra, Mario; Riller, Ulrich; Sato, Honami; Schmitt, Douglas R; Smit, Jan; Tikoo, Sonia; Tomioka, Naotaka; Urrutia-Fucugauchi, Jaime; Whalen, Michael; Wittmann, Axel; Yamaguchi, Kosei E; Zylberman, William

    2016-11-18

    Large impacts provide a mechanism for resurfacing planets through mixing near-surface rocks with deeper material. Central peaks are formed from the dynamic uplift of rocks during crater formation. As crater size increases, central peaks transition to peak rings. Without samples, debate surrounds the mechanics of peak-ring formation and their depth of origin. Chicxulub is the only known impact structure on Earth with an unequivocal peak ring, but it is buried and only accessible through drilling. Expedition 364 sampled the Chicxulub peak ring, which we found was formed from uplifted, fractured, shocked, felsic basement rocks. The peak-ring rocks are cross-cut by dikes and shear zones and have an unusually low density and seismic velocity. Large impacts therefore generate vertical fluxes and increase porosity in planetary crust. Copyright © 2016, American Association for the Advancement of Science.

  5. The formation of peak rings in large impact craters

    Science.gov (United States)

    Morgan, Joanna V.; Gulick, Sean P. S.; Bralower, Timothy; Chenot, Elise; Christeson, Gail; Claeys, Philippe; Cockell, Charles; Collins, Gareth S.; Coolen, Marco J. L.; Ferrière, Ludovic; Gebhardt, Catalina; Goto, Kazuhisa; Jones, Heather; Kring, David A.; Le Ber, Erwan; Lofi, Johanna; Long, Xiao; Lowery, Christopher; Mellett, Claire; Ocampo-Torres, Rubén; Osinski, Gordon R.; Perez-Cruz, Ligia; Pickersgill, Annemarie; Poelchau, Michael; Rae, Auriol; Rasmussen, Cornelia; Rebolledo-Vieyra, Mario; Riller, Ulrich; Sato, Honami; Schmitt, Douglas R.; Smit, Jan; Tikoo, Sonia; Tomioka, Naotaka; Urrutia-Fucugauchi, Jaime; Whalen, Michael; Wittmann, Axel; Yamaguchi, Kosei E.; Zylberman, William

    2016-11-01

    Large impacts provide a mechanism for resurfacing planets through mixing near-surface rocks with deeper material. Central peaks are formed from the dynamic uplift of rocks during crater formation. As crater size increases, central peaks transition to peak rings. Without samples, debate surrounds the mechanics of peak-ring formation and their depth of origin. Chicxulub is the only known impact structure on Earth with an unequivocal peak ring, but it is buried and only accessible through drilling. Expedition 364 sampled the Chicxulub peak ring, which we found was formed from uplifted, fractured, shocked, felsic basement rocks. The peak-ring rocks are cross-cut by dikes and shear zones and have an unusually low density and seismic velocity. Large impacts therefore generate vertical fluxes and increase porosity in planetary crust.

  6. Axial length estimation error caused by hidden double-peak on partial coherence interferometry in an eye with epiretinal membrane: a case report

    Directory of Open Access Journals (Sweden)

    Kitaguchi Y

    2014-03-01

    Full Text Available Yoshiyuki Kitaguchi, Shinsaku Yano, Fumi Gomi Department of Ophthalmology, Sumitomo Hospital, Osaka, Japan Abstract: Here we report a patient in whom there was a myopic shift after combined cataract surgery and pars plana vitrectomy against the epiretinal membrane, related to axial measurement estimation error caused by a hidden double-peak appearance on partial coherence interferometry measurement. A 52-year-old female presented with epiretinal membrane and underwent combined cataract surgery and pars plana vitrectomy. Axial length was measured with partial coherence interferometry. Although the signal curve in the summary display showed a single peak, a 1.6 diopter myopic shift occurred. Viewed retrospectively, six of 20 individual signal curves showed a double peak. Most of them showed a higher anterior peak, with only one having a higher posterior peak. The other 14 curves showed a single peak at a similar distance to an anterior peak. The anterior peak appeared to be derived from the epiretinal membrane. The possibility of a double peak should always be considered in patients with epiretinal membrane even if the summary display of the partial coherence interferometry measurement shows a single peak. Checking all signal curves would reduce the risk of missing a hidden double peak. Keywords: intraocular lens, master, double peak, epiretinal membrane

  7. Nature of the narrow optical band in H*-aggregates: Dozy-chaos–exciton coupling

    Energy Technology Data Exchange (ETDEWEB)

    Egorov, Vladimir V., E-mail: egorov@photonics.ru [Photochemistry Center, Russian Academy of Sciences, Moscow, 119421 (Russian Federation)

    2014-07-15

    Dozy chaos emerges as a combined effect of the collective chaotic motion of electrons and nuclei, and their chaotic electromagnetic interactions in the transient state of molecules experiencing quantum transitions. Following earlier discussions of the well-known Brönsted relations for proton-transfer reactions; the temperature-dependent electron transfer in Langmuir–Blodgett films; the shape of the optical bands of polymethine dye monomers, their dimers, and J-aggregates, this paper reports one more application of the dozy-chaos theory of molecular quantum transitions. The qualitative and quantitative explanations for shape of a narrow and blue-shifted optical absorption band in H{sup *}-aggregates is given on the basis of the dozy-chaos theory by taking into account the dozy-chaos–exciton coupling effect. It is emphasized that in the H{sup *}-aggregate chromophore (dimer of cyclic bis-thiacarbocyanines) there is a competition between two Frenkel exciton transitions through the chaotic reorganization motion of nuclear environment. As a result, the highly organized quantum transition to the upper exciton state becomes an exciton-induced source of dozy chaos for the low organized transition to the lower exciton state. This manifests itself in appearing the narrow peak and broad wing in the optical spectrum pattern of H{sup *}-aggregates. A similar enhancement in the H{sup *}-effect caused by the strengthening of the exciton coupling in H{sup *}-dimers, which could be achieved by synthesizing tertiary and quarternary thiacarbocyanine monomers, is predicted.

  8. Accretion/jet activity and narrow [O III] kinematics in young radio galaxies

    Institute of Scientific and Technical Information of China (English)

    Andrew; HUMPHREY

    2010-01-01

    We estimate black hole masses and Edenton ratios for a sample of 81 young radio galaxies,which includes 42 compact steep-spectrum(CSS) and 39 gigahertz-peaked spectrum(GPS) sources.We find that the average black hole(BH) mass of these young radio galaxies is〈log Mbh〉-8.3,which is less than that of radio loud QSOs and low redshift radio galaxies(〈 log Mbh〉-9.0).The CSS/GPS sources have relatively high Eddington ratios,with an average value of〈log Lbol/LEdd〉=-0.75,which are similar to those of narrow line Seyfert 1 galaxies(NLS1s).This suggests that young radio galaxies may not only be in the early stages of their radio activity,but also in the early stage of their accretion activity.We find that the young radio galaxies,as a class,systematically deviate from the Mbh-σ relation defined by nearby inactive galaxies,when using σ[O III] as a surrogate for stellar velocity dispersion σ.We also find that the deviation of the [O III] line width,Δσ =σ[O III]-σ[pred],is correlated with the Eddington ratio;sources with Lbol/LEdd-1 have the largest deviations,which are similar to those of radio quiet QSOs/NLS1s(i.e.,sources in which the radio jets are absent or weak),and where σ[pred] is calculated from the Tremaine et al.relation using our estimated BH masses.A similar result has been obtained for 9 linear radio Seyfert galaxies.On the basis of these results,we suggest that,in addition to the possible jet-gas interactions,accretion activities may also play an important role in shaping the kinematics of the narrow [O III] line in young radio galaxies.

  9. Automatic Peak Selection by a Benjamini-Hochberg-Based Algorithm

    KAUST Repository

    Abbas, Ahmed

    2013-01-07

    A common issue in bioinformatics is that computational methods often generate a large number of predictions sorted according to certain confidence scores. A key problem is then determining how many predictions must be selected to include most of the true predictions while maintaining reasonably high precision. In nuclear magnetic resonance (NMR)-based protein structure determination, for instance, computational peak picking methods are becoming more and more common, although expert-knowledge remains the method of choice to determine how many peaks among thousands of candidate peaks should be taken into consideration to capture the true peaks. Here, we propose a Benjamini-Hochberg (B-H)-based approach that automatically selects the number of peaks. We formulate the peak selection problem as a multiple testing problem. Given a candidate peak list sorted by either volumes or intensities, we first convert the peaks into p-values and then apply the B-H-based algorithm to automatically select the number of peaks. The proposed approach is tested on the state-of-the-art peak picking methods, including WaVPeak [1] and PICKY [2]. Compared with the traditional fixed number-based approach, our approach returns significantly more true peaks. For instance, by combining WaVPeak or PICKY with the proposed method, the missing peak rates are on average reduced by 20% and 26%, respectively, in a benchmark set of 32 spectra extracted from eight proteins. The consensus of the B-H-selected peaks from both WaVPeak and PICKY achieves 88% recall and 83% precision, which significantly outperforms each individual method and the consensus method without using the B-H algorithm. The proposed method can be used as a standard procedure for any peak picking method and straightforwardly applied to some other prediction selection problems in bioinformatics. The source code, documentation and example data of the proposed method is available at http://sfb.kaust.edu.sa/pages/software.aspx. © 2013

  10. Automatic peak selection by a Benjamini-Hochberg-based algorithm.

    Directory of Open Access Journals (Sweden)

    Ahmed Abbas

    Full Text Available A common issue in bioinformatics is that computational methods often generate a large number of predictions sorted according to certain confidence scores. A key problem is then determining how many predictions must be selected to include most of the true predictions while maintaining reasonably high precision. In nuclear magnetic resonance (NMR-based protein structure determination, for instance, computational peak picking methods are becoming more and more common, although expert-knowledge remains the method of choice to determine how many peaks among thousands of candidate peaks should be taken into consideration to capture the true peaks. Here, we propose a Benjamini-Hochberg (B-H-based approach that automatically selects the number of peaks. We formulate the peak selection problem as a multiple testing problem. Given a candidate peak list sorted by either volumes or intensities, we first convert the peaks into [Formula: see text]-values and then apply the B-H-based algorithm to automatically select the number of peaks. The proposed approach is tested on the state-of-the-art peak picking methods, including WaVPeak [1] and PICKY [2]. Compared with the traditional fixed number-based approach, our approach returns significantly more true peaks. For instance, by combining WaVPeak or PICKY with the proposed method, the missing peak rates are on average reduced by 20% and 26%, respectively, in a benchmark set of 32 spectra extracted from eight proteins. The consensus of the B-H-selected peaks from both WaVPeak and PICKY achieves 88% recall and 83% precision, which significantly outperforms each individual method and the consensus method without using the B-H algorithm. The proposed method can be used as a standard procedure for any peak picking method and straightforwardly applied to some other prediction selection problems in bioinformatics. The source code, documentation and example data of the proposed method is available at http://sfb.kaust.edu.sa/pages/software.aspx.

  11. Hydroclimatology of Dual-Peak Annual Cholera Incidence: Insights from a Spatially Explicit Model

    Science.gov (United States)

    Bertuzzo, E.; Mari, L.; Righetto, L.; Gatto, M.; Casagrandi, R.; Rodriguez-Iturbe, I.; Rinaldo, A.

    2012-12-01

    Cholera incidence in some regions of the Indian subcontinent may exhibit two annual peaks although the main environmental drivers that have been linked to the disease (e.g. sea surface temperature, zooplankton abundance, river discharge) peak once per year during the summer. An empirical hydroclimatological explanation relating cholera transmission to river flows and to the disease spatial spreading has been recently proposed. We specifically support and substantiate mechanistically such hypothesis by means of a spatially explicit model of cholera transmission. Our framework directly accounts for the role of the river network in transporting and redistributing cholera bacteria among human communities as well as for spatial and temporal annual fluctuations of precipitation and river flows. To single out the single out the hydroclimatologic controls on the prevalence patterns in a non-specific geographical context, we first apply the model to Optimal Channel Networks as a general model of hydrological networks. Moreover, we impose a uniform distribution of population. The model is forced by seasonal environmental drivers, namely precipitation, temperature and chlorophyll concentration in the coastal environment, a proxy for Vibrio cholerae concentration. Our results show that these drivers may suffice to generate dual-peak cholera prevalence patterns for proper combinations of timescales involved in pathogen transport, hydrologic variability and disease unfolding. The model explains the possible occurrence of spatial patterns of cholera incidence characterized by a spring peak confined to coastal areas and a fall peak involving inland regions. We then proceed applying the model to the specific settings of Bay of Bengal accounting for the actual river networks (derived from digital terrain map manipulations), the proper distribution of population (estimated from downscaling of census data based on remotely sensed features) and precipitation patterns. Overall our

  12. Gas-filled cell as a narrow bandwidth bandpass filter in the VUV wavelength range

    CERN Document Server

    Geloni, Gianluca; Saldin, Evgeni

    2011-01-01

    We propose a method for spectrally filtering radiation in the VUV wavelength range by means of a monochromator constituted by a cell filled with a resonantly absorbing rare gas. Around particular wavelengths, the gas exhibits narrow-bandwidth absorbing resonances following the Fano profile. In particular, within the photon energy range 60 eV - 65 eV, the correlation index of the Fano profiles for the photo-ionization spectra in Helium is equal to unity, meaning that the minimum of the cross-section is exactly zero. For sufficiently large column density in the gas cell, the spectrum of the incoming radiation will be attenuated by the background cross-section of many orders of magnitude, except for those wavelengths close to the point where the cross-section is zero. Remarkable advantages of a gas monochromator based on this principle are simplicity, efficiency and narrow-bandwidth. A gas monochromator installed in the experimental hall of a VUV SASE FEL facility would enable the delivery of a single-mode VUV l...

  13. A Search for Narrow Vertical Structures in the Canadian Galactic Plane Survey

    CERN Document Server

    Asgekar, A; Safi-Harb, S; Kothes, R; Asgekar, Ashish; English, Jayanne; Safi-Harb, Samar; Kothes, Roland

    2004-01-01

    Worms are defined to be dusty, atomic hydrogen (HI) structures which are observed in low resolution data to rise perpendicular to the Galactic plane. Data from the 1'-resolution Canadian Galactic Plane Survey (CGPS) were systematically searched for narrow vertical HI structures which could be resolved worms. Another motivation for the search was to explore the scenario that mushroom-shaped worms like GW123.4-1.5, studied by English and collaborators, could be generated by a single supernova. However no other vertical structures of mushroom-shape morphology were found. We also examined objects previously classified as worm candidates by Koo and collaborators; only 7 have a significant portion of their structure falling in the CGPS range of l=74 deg to 147 deg, -3.5 deg ~ 500 pc tall, thus extending from the Galactic plane into the halo. We provide details about these narrow vertical structures, including comparisons between HI, radio continuum, IR, and CO observations. Our search was conducted by visual inspec...

  14. Narrowing SWNT diameter distribution using size-separated ferritin-based Fe catalysts.

    Science.gov (United States)

    Durrer, Lukas; Greenwald, Jason; Helbling, Thomas; Muoth, Matthias; Riek, Roland; Hierold, Christofer

    2009-09-02

    Sensors and devices made from single-walled carbon nanotubes (SWNTs) are most often electrically probed through metal leads contacting the semiconducting SWNTs (s-SWNTs). Contact barriers in general and Schottky barriers (SBs) in particular are usually obtained at a metal-semiconductor interface. The unique one-dimensional structure (1D) of SWNTs allows tailoring of the SB heights through the contact metal type and the size of the s-SWNT bandgap. A large workfunction reduces the SB height (e.g. using Pd as the metal contact material). The bandgap of an SWNT is inversely proportional to its diameter. Ohmic contacts--the preferable choice--are achieved for s-SWNTs with diameters greater than 2 nm on Pd metal leads. SWNT device reproducibility, on the other hand, requires a narrow distribution of the SWNT diameters. Here, we present a method to fabricate SWNTs with a large and adjustable mean diameter (1.9-2.4 nm) and very narrow diameter distribution (+/- 0.27 nm at mean diameter 1.9 nm). The results are achieved through a size separation of the ferritin catalyst particles by sedimentation velocity centrifugation prior to their use in the chemical vapor deposition (CVD) formation of SWNTs.

  15. Narrowing SWNT diameter distribution using size-separated ferritin-based Fe catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Durrer, Lukas; Helbling, Thomas; Muoth, Matthias; Hierold, Christofer [Micro and Nanosystems, Department of Mechanical and Process Engineering, ETH Zuerich, CH-8092 Zurich (Switzerland); Greenwald, Jason; Riek, Roland, E-mail: lukas.durrer@micro.mavt.ethz.c [Laboratory of Physical Chemistry, ETH Zurich, CH-8093 Zuerich (Switzerland)

    2009-09-02

    Sensors and devices made from single-walled carbon nanotubes (SWNTs) are most often electrically probed through metal leads contacting the semiconducting SWNTs (s-SWNTs). Contact barriers in general and Schottky barriers (SBs) in particular are usually obtained at a metal-semiconductor interface. The unique one-dimensional structure (1D) of SWNTs allows tailoring of the SB heights through the contact metal type and the size of the s-SWNT bandgap. A large workfunction reduces the SB height (e.g. using Pd as the metal contact material). The bandgap of an SWNT is inversely proportional to its diameter. Ohmic contacts-the preferable choice-are achieved for s-SWNTs with diameters greater than 2 nm on Pd metal leads. SWNT device reproducibility, on the other hand, requires a narrow distribution of the SWNT diameters. Here, we present a method to fabricate SWNTs with a large and adjustable mean diameter (1.9-2.4 nm) and very narrow diameter distribution ({+-} 0.27 nm at mean diameter 1.9 nm). The results are achieved through a size separation of the ferritin catalyst particles by sedimentation velocity centrifugation prior to their use in the chemical vapor deposition (CVD) formation of SWNTs.

  16. Genetic analysis and gene mapping of a narrow leaf mutant in rice (Oryza sativa L.)

    Institute of Scientific and Technical Information of China (English)

    WANG DeKai; LIU HeQin; LI KeLei; LI SuJuan; TAO YueZhi

    2009-01-01

    A narrow leaf mutant was obtained after T-DNA transformation conducted on a rice variety Zhonghua 11. Several abnormal morphological characteristics, including semi-dwarf, delayed flowering time, narrow and inward rolling leaves, and lower seed-setting, were observed. The rate of net photosynthesis (un-der saturate light) of flag leaves in the mutant was significantly lower than that of the wild type. More-over, the leaf transpiration rate and stomatal conductance in the mutant flag leaf were lower than those of the wild type at the grain filling stage. It was found that the mutant phenotype was not caused by the T-DNA insertion. Genetic analysis showed that the mutant was controlled by a single recessive gene,designated as nal3(t). A genetic linkage map was constructed using a large F2 mapping population de-rived from a cross between nal3(t) and an indica variety Longtefu B with 6 polymorphic markers on chromosome 12 identified from 366 SSR markers by the BAS method. Gene nal3(t) was mapped be-tween the markers RM7018 and RM3331. Fine mapping of nal3(t) locus was conducted with 22 newly developed STS markers based on the sequence diversity around the region harboring nal3(t) between Nipponbare and 93-11, and nal3(f) was finally mapped to a 136-kb region between the STS markers NS10 and RH12-8.

  17. Numerical modeling and verification of gas flow through a network of crossed narrow v-grooves

    Science.gov (United States)

    Bejhed, Johan; Nguyen, Hugo; Åstrand, Peter; Eriksson, Anders; Köhler, Johan

    2006-10-01

    The gas flow through a network of crossing thin micro-machined channels has been successfully modeled and simulated. The crossings are formed by two sets of v-grooves that intersect as two silicon wafers are bonded together. The gas is distributed from inlets via a manifold of channels to the narrow v-grooves. The narrow v-grooves could work as a particle filter. The fluidic model is derived from the Navier-Stokes equation and assumes laminar isothermal flow and incorporates small Knudsen number corrections and Poiseuille number calculations. The simulations use the finite element method. Several elements of the full crossing network model are treated separately before lumping them together: the straight v-grooves, a single crossing in an infinite set and a set of exactly four crossings along the flow path. The introduction of a crossing effectively corresponds to a virtual reduction of the length of the flow path, thereby defining a new effective length. The first and last crossings of each flow path together contribute to a pressure drop equal to that from three ordinary crossings. The derived full network model has been compared to previous experimental results on several differently shaped crossed v-groove networks. Within the experimental errors, the model corresponds to the mass flow and pressure drop measurements. The main error source is the uncertainty in v-groove width which has a profound impact on the fluidic behavior.

  18. MULTI-PEAK MATCH INTENSITY RATIO METHOD OF QUANTITATIVE X-RAY DIFFRACTION PHASE ANALYSIS

    Institute of Scientific and Technical Information of China (English)

    G. Chu; Y.F. Cong; H.J. You

    2003-01-01

    A new method for quantitative phase analysis is proposed by using X-ray diffraction multi-peak match intensity ratio. This method can obtain the multi-peak match intensity ratio among each phase in the mixture sample by using all diffraction peak data in the mixture sample X-ray diffraction spectrum and combining the relative intensity distribution data of each phase standard peak in JCPDS card to carry on the least square method regression analysis. It is benefit to improve the precision of quantitative phase analysis that the given single line ratio which is usually adopted is taken the place of the multi-peak match intensity ratio and is used in X-ray diffraction quantitative phase analysis of the mixture sample. By analyzing four-group mixture sample, adopting multi-peak match intensity ratio and X-ray diffraction quantitative phase analysis principle of combining the adiabatic and matrix flushing method, it is tested that the experimental results are identical with theory.

  19. Nasal base narrowing: the combined alar base excision technique.

    Science.gov (United States)

    Foda, Hossam M T

    2007-01-01

    To evaluate the role of the combined alar base excision technique in narrowing the nasal base and correcting excessive alar flare. The study included 60 cases presenting with a wide nasal base and excessive alar flaring. The surgical procedure combined an external alar wedge resection with an internal vestibular floor excision. All cases were followed up for a mean of 32 (range, 12-144) months. Nasal tip modification and correction of any preexisting caudal septal deformities were always completed before the nasal base narrowing. The mean width of the external alar wedge excised was 7.2 (range, 4-11) mm, whereas the mean width of the sill excision was 3.1 (range, 2-7) mm. Completing the internal excision first resulted in a more conservative external resection, thus avoiding any blunting of the alar-facial crease. No cases of postoperative bleeding, infection, or keloid formation were encountered, and the external alar wedge excision healed with an inconspicuous scar that was well hidden in the depth of the alar-facial crease. Finally, the risk of notching of the alar rim, which can occur at the junction of the external and internal excisions, was significantly reduced by adopting a 2-layered closure of the vestibular floor (P = .01). The combined alar base excision resulted in effective narrowing of the nasal base with elimination of excessive alar flare. Commonly feared complications, such as blunting of the alar-facial crease or notching of the alar rim, were avoided by using simple modifications in the technique of excision and closure.

  20. Woodruff Narrows low head hydroelectric power plant feasibility determination

    Energy Technology Data Exchange (ETDEWEB)

    1979-03-01

    Woodruff Narrows Reservoir, owned by the State of Utah, was built in 1961 as an irrigation reservoir. The reservoir outlet works and spillway are in need of repair, and plans have been made to enlarge the reservoir from its present capacity of 28,000 acre-feet to 53,200 acre-feet when these repairs are made. The purpose of this study was to determine if it is feasible to add hydropower facilities when the reservoir is repaired and enlarged. A computer simulation model based on mean monthly values, utilizing 26 years of recorded streamflow into the reservoir, was used to determine the mean annual energy potential for the following configurations: (1) present dam, (2) the proposed enlarged dam, (3) a new dam at the lower site with a maximum head of 65 feet, and (4) a new dam at the lower site which would store water to the same elevation as the proposed enlarged dam. Results of the simulation study show that maximum power capacities are respectively 2.1, 3.0, 3.9, and 4.5 megawatts. The marketing potential for this electric power, cost estimates and financial analysis, and environmental, social, and regulatory aspects of the proposed hydropower facilities were evaluated. The results showed the addition of hydroelectric power development at the Woodruff Narrows site would have minimal social and environmental effects on the area, would result in little or no changes in the present patterns of water and land use, income, population, and employment and would not result in any significant changes of the social structure or characteristics of the area. However, hydroelectric power development at the Woodruff Narrows site is not economically feasible at the present time. (LCL)

  1. Theta Brain Rhythms Index Perceptual Narrowing in Infant Speech Perception

    Directory of Open Access Journals (Sweden)

    Alexis eBosseler

    2013-10-01

    Full Text Available The development of speech perception shows a dramatic transition between infancy and adulthood. Between 6 and 12 months, infants’ initial ability to discriminate all phonetic units across the worlds’ languages narrows—native discrimination increases while nonnative discrimination shows a steep decline. We used magnetoencephalography (MEG to examine whether brain oscillations in the theta band (4-8Hz, reflecting increases in attention and cognitive effort, would provide a neural measure of the perceptual narrowing phenomenon in speech. Using an oddball paradigm, we varied speech stimuli in two dimensions, stimulus frequency (frequent vs. infrequent and language (native vs. nonnative speech syllables and tested 6-month-old infants, 12-month-old infants, and adults. We hypothesized that 6-month-old infants would show increased relative theta power (RTP for frequent syllables, regardless of their status as native or nonnative syllables, reflecting young infants’ attention and cognitive effort in response to highly frequent stimuli (statistical learning. In adults, we hypothesized increased RTP for nonnative stimuli, regardless of their presentation frequency, reflecting increased cognitive effort for nonnative phonetic categories. The 12-month-old infants were expected to show a pattern in transition, but one more similar to adults than to 6-month-old infants. The MEG brain rhythm results supported these hypotheses. We suggest that perceptual narrowing in speech perception is governed by an implicit learning process. This learning process involves an implicit shift in attention from frequent events (infants to learned categories (adults. Theta brain oscillatory activity may provide an index of perceptual narrowing beyond speech, and would offer a test of whether the early speech learning process is governed by domain-general or domain-specific processes.

  2. Perceptual training narrows the temporal window of multisensory binding

    Science.gov (United States)

    Powers, Albert R.; Hillock, Andrea R.; Wallace, Mark T.

    2009-01-01

    The brain’s ability to bind incoming auditory and visual stimuli depends critically on the temporal structure of this information. Specifically, there exists a temporal window of audiovisual integration within which stimuli are highly likely to be bound together and perceived as part of the same environmental event. Several studies have described the temporal bounds of this window, but few have investigated its malleability. Here, the plasticity in the size of this temporal window was investigated using a perceptual learning paradigm in which participants were given feedback during a two-alternative forced-choice (2-AFC) audiovisual simultaneity judgment task. Training resulted in a marked (i.e., approximately 40%) narrowing in the size of the window. To rule out the possibility that this narrowing was the result of changes in cognitive biases, a second experiment employing a two-interval forced choice (2-IFC) paradigm was undertaken during which participants were instructed to identify a simultaneously-presented audiovisual pair presented within one of two intervals. The 2-IFC paradigm resulted in a narrowing that was similar in both degree and dynamics to that using the 2-AFC approach. Together, these results illustrate that different methods of multisensory perceptual training can result in substantial alterations in the circuits underlying the perception of audiovisual simultaneity. These findings suggest a high degree of flexibility in multisensory temporal processing and have important implications for interventional strategies that may be used to ameliorate clinical conditions (e.g., autism, dyslexia) in which multisensory temporal function may be impaired. PMID:19793985

  3. Torsional instability in suspension bridges: The Tacoma Narrows Bridge case

    Science.gov (United States)

    Arioli, Gianni; Gazzola, Filippo

    2017-01-01

    All attempts of aeroelastic explanations for the torsional instability of suspension bridges have been somehow criticised and none of them is unanimously accepted by the scientific community. We suggest a new nonlinear model for a suspension bridge and we perform numerical experiments with the parameters corresponding to the collapsed Tacoma Narrows Bridge. We show that the thresholds of instability are in line with those observed the day of the collapse. Our analysis enables us to give a new explanation for the torsional instability, only based on the nonlinear behavior of the structure.

  4. Emerging role of narrow band imaging in duodenum

    Institute of Scientific and Technical Information of China (English)

    Amit; Kumar; Dutta; Ashok; Chacko

    2015-01-01

    Endoscopy using magnification narrow band imaging(m NBI) allows detailed assessment of mucosal surface and vascular pattern. This may help in better identification and prediction of the nature of the lesion. The role of this technology in duodenum is still evolving. Studies have shown that m NBI has high accuracy in predicting villous atrophy in the duodenum. Limited data suggests that this technique can provide additional information on duodenal polyps,nodules and ampullary tumour which can help guide their management. In this paper we describe the technique for duodenal assessment using NBI and review the existing literature evaluating its role in diagnosis of various duodenal pathologies.

  5. Internalization of Calcium Oxalate Calculi Developed in Narrow Cavities

    Directory of Open Access Journals (Sweden)

    Fèlix Grases

    2014-03-01

    Full Text Available We describe the case of a patient with calcium oxalate monohydrate and calcium oxalate dihydrate calculi occluded in cavities. All those calculi were located inside narrow cavities covered with a thin epithelium that permits their visualization. Urinary biochemical analysis showed high calciuria, not hypercalciuria, hypocitraturia, and a ratio [calcium]/[citrate] >0.33. The existence of cavities of very low urodynamic efficacy was decisive in the formation of such calculi. It is important to emphasize that we observed a thin epithelium covering such cavities, demonstrating that this epithelium may be formed after the development of the calculi through a re-epithelialization process.

  6. Tunable polarization plasma channel undulator for narrow bandwidth photon emission

    Science.gov (United States)

    Rykovanov, S. G.; Wang, J. W.; Kharin, V. Yu.; Lei, B.; Schroeder, C. B.; Geddes, C. G. R.; Esarey, E.; Leemans, W. P.

    2016-09-01

    The theory of a plasma undulator excited by a short intense laser pulse in a parabolic plasma channel is presented. The undulator fields are generated either by the laser pulse incident off-axis and/or under the angle with respect to the channel axis. Linear plasma theory is used to derive the wakefield structure. It is shown that the electrons injected into the plasma wakefields experience betatron motion and undulator oscillations. Optimal electron beam injection conditions are derived for minimizing the amplitude of the betatron motion, producing narrow-bandwidth undulator radiation. Polarization control is readily achieved by varying the laser pulse injection conditions.

  7. Masas de agujeros negros en Narrow Line Seyfert 1

    Science.gov (United States)

    Schmidt, E.; Ferreiro, D.; Oio, G.; Vega, L.; Donoso, L.

    We describe two of the ways to estimate black hole masses in AGN, and then we estimate the black hole masses of 13 Narrow Line Seyfert 1 galaxies with the two methods: virial masses, using the correlation found by Greene & Ho (2005, ApJ, 630, 122); and the correlation found by Tremaine et al. (2002, ApJ, 574, 740). For this work we analyzed the optical spectroscopy data we obtained from CASLEO (San Juan). We compare the results obtained through both methods. FULL TEXT IN SPANISH

  8. Narrow beam dosimetry for high-energy hadrons and electrons

    CERN Document Server

    Pelliccioni, M; Ulrici, Luisa

    2001-01-01

    Organ doses and effective dose were calculated with the latest version of the Monte Carlo transport code FLUKA in the case of an anthropomorphic mathematical model exposed to monoenergetic narrow beams of protons, pions and electrons in the energy range 10°— 400 GeV. The target organs considered were right eye, thyroid, thymus, lung and breast. Simple scaling laws to the calculated values are given. The present data and formula should prove useful for dosimetric estimations in case of accidental exposures to high-energy beams.

  9. Narrow beam dosimetry for high energy hadrons and electrons.

    Science.gov (United States)

    Pelliccioni, M; Silari, M; Ulrici, L

    2001-01-01

    Organ doses and effective dose were calculated with the latest version of the Monte Carlo transport code FLUKA in the case of an anthropomorphic mathematical model exposed to monoenergetic narrow beams of protons, pions and electrons in the energy range 10-400 GeV. The target organs considered were right eye, thyroid, thymus, lung and breast. Simple scaling laws to the calculated values are given. The present data and formulae should prove useful for dosimetric estimations in the case of accidental exposures to high energy beams.

  10. The Narrow-Field Telescope Science Case: A Proposal

    Science.gov (United States)

    Richer, M. G.

    2007-06-01

    Based upon the capabilities that are likely to be available from space and terrestrial observatories around 2015-2020 and the traditional interests of the Mexican astronomical community, I propose that the narrow-field telescope (NFT) be dedicated to high resolution spectroscopy covering wavelengths from the optical to the mid-infrared and adaptive optics imaging and spectroscopy (medium to high spectral resolution) in the near-infrared. These capabilities would permit studying the processes responsible for galaxy evolution after the epoch of mass assembly: the development of galactic structure, star formation, stellar structure and mass distributions, the kinematics and chemical composition of stars and the interstellar medium (ISM).

  11. Bayesian-Augmented Identification of Stars in a Narrow View

    Science.gov (United States)

    Clouse, Daniel; Padgett, Curtis

    2004-01-01

    An algorithm for the identification of stars from a charge-coupled-device (CCD) image of a star field has been extended for use with narrower field-of-view images. Previously, the algorithm had been shown to be effective at a field of view of 8 degrees. This work augments the earlier algorithm using Bayesian decision theory. The new algorithm is shown to be capable of effective star identification down to a field of view of 2 degrees. The algorithm was developed for use in estimating the attitude of a spacecraft and could be used on Earth to help in the identification of stars and other celestial objects for astronomical observations.

  12. Evidence for a Narrow Anti-Charmed Baryon State

    CERN Document Server

    Aktas, A; Anthonis, T; Asmone, A; Babaev, A; Backovic, S; Bähr, J; Baranov, P; Barrelet, E; Bartel, Wulfrin; Baumgartner, S; Becker, J; Beckingham, M; Behnke, O; Behrendt, O; Belousov, A; Berger, C; Berger, N; Berndt, T; Bizot, J C; Böhme, J; Boenig, M O; Boudry, V; Bracinik, J; Brisson, V; Broker, H B; Brown, D P; Bruncko, Dusan; Büsser, F W; Bunyatyan, A; Buschhorn, G; Bystritskaya, L; Campbell, A J; Caron, S; Cassol-Brunner, F; Cerny, K; Chekelian, V; Collard, Caroline; Contreras, J G; Coppens, Y R; Coughlan, J A; Cox, B E; Cozzika, G; Cvach, J; Dainton, J B; Dau, W D; Daum, K; Delcourt, B; Demirchyan, R; de Roeck, A; Desch, Klaus; De Wolf, E A; Diaconu, C; Dingfelder, J; Dodonov, V; Dubak, A; Duprel, C; Eckerlin, G; Efremenko, V; Egli, S; Eichler, R; Eisele, F; Ellerbrock, M; Elsen, E; Erdmann, M; Erdmann, W; Faulkner, P J W; Favart, L; Fedotov, A; Felst, R; Ferencei, J; Fleischer, M; Fleischmann, P; Fleming, Y H; Flucke, G; Flügge, G; Fomenko, A; Foresti, I; Formánek, J; Franke, G; Frising, G; Gabathuler, Erwin; Gabathuler, K; Garutti, E; Garvey, J; Gayler, J; Gerhards, R; Gerlich, C; Ghazaryan, S; Glazov, A; Görlich, L; Gogitidze, N; Gorbounov, S; Grab, C; Grässler, Herbert; Greenshaw, T; Gregori, M; Grindhammer, G; Gwilliam, C; Haidt, D; Hajduk, L; Haller, J; Hansson, M; Heinzelmann, G; Henderson, R C W; Henschel, H; Henshaw, O; Heremans, R; Herrera-Corral, G; Herynek, I; Heuer, R D; Hildebrandt, M; Hiller, K H; Hoting, P; Hoffmann, D; Horisberger, R P; Hovhannisyan, A; Ibbotson, M; Ismail, M; Jacquet, M; Janauschek, L; Janssen, X; Jemanov, V; Jönsson, L B; Johnson, D P; Jung, H; Kant, D; Kapichine, M; Karlsson, M; Katzy, J; Keller, N; Kennedy, J; Kenyon, I R; Kiesling, C; Klein, M; Kleinwort, C; Klimkovich, T; Kluge, T; Knies, G; Knutsson, A; Koblitz, B; Korbel, V; Kostka, P; Koutouev, R; Kropivnitskaya, A; Kroseberg, J; Kuckens, J; Kuhr, T; Landon, M P J; Lange, W; Lastoviicka, T; Laycock, P; Lebedev, A; Leiner, B; Lemrani, R; Lendermann, V; Levonian, S; Lindfeld, L; Lipka, K; List, B; Lobodzinska, E; Loktionova, N A; López-Fernandez, R; Lubimov, V; Lüders, H; Lüke, D; Lux, T; Lytkin, L; Makankine, A; Malden, N; Malinovskii, E I; Mangano, S; Marage, P; Marks, J; Marshall, R; Martisikova, M; Martyn, H U; Maxfield, S J; Meer, D; Mehta, A; Meier, K; Meyer, A B; Meyer, H; Meyer, J; Michine, S; Mikocki, S; Milcewicz, I; Milstead, D; Mohamed, A; Moreau, F; Morozov, A; Morozov, I; Morris, J V; Mozer, M U; Müller, K; Murn, P; Nagovizin, V; Naroska, Beate; Naumann, J; Naumann, T; Newman, P R; Niebuhr, C B; Nikiforov, A; Nikitin, D K; Nowak, G; Nozicka, M; Oganezov, R; Olivier, B; Olsson, J E; Ossoskov, G; Ozerov, D; Pascaud, C; Patel, G D; Peez, M; Pérez, E; Perieanu, A; Petrukhin, A; Pitzl, D; Placakyte, R; Pöschl, R; Portheault, B; Povh, B; Raicevic, N; Ratiani, Z; Reimer, P; Reisert, B; Rimmer, A; Risler, C; Rizvi, E; Robmann, P; Roland, B; Roosen, R; Rostovtsev, A A; Rurikova, Z; Rusakov, S V; Rybicki, K; Sankey, D P C; Sauvan, E; Schatzel, S; Scheins, J; Schilling, F P; Schleper, P; Schmidt, S; Schmitt, S; Schneider, M; Schoeffel, L; Schöning, A; Schröder, V; Schultz-Coulon, H C; Schwanenberger, C; Sedlak, K; Sefkow, F; Shevyakov, I; Shtarkov, L N; Sirois, Y; Sloan, T; Smirnov, P; Soloviev, Yu; South, D; Spaskov, V; Specka, A; Spitzer, H; Stamen, R; Stella, B; Stiewe, J; Strauch, I; Straumann, U; Tchoulakov, V; Thompson, G; Thompson, P D; Tomasz, F; Traynor, D; Truöl, P; Tsipolitis, G; Tsurin, I; Turnau, J; Tzamariudaki, E; Uraev, A; Urban, M; Usik, A; Utkin, D; Valkár, S; Valkárová, A; Vallée, C; Van Mechelen, P; Van, N; Remortel; Vargas-Trevino, A; Vazdik, Ya A; Veelken, C; Vest, A; Vinokurova, S; Volchinski, V; Wacker, K; Wagner, J; Weber, G; Weber, R; Wegener, D; Werner, C; Werner, N; Wessels, M; Wessling, B; Winter, G G; Wissing, C; Woerling, E E; Wolf, R; Wünsch, E; Xella, S M; Yan, W; Yeganov, V; Zaicek, J; Zaleisak, J; Zhang, Z; Zhokin, A; Zohrabyan, H G; Zomer, F

    2004-01-01

    A narrow resonance in D*- p and D*+ pbar invariant mass combinations is observed in inelastic electron-proton collisions at centre-of-mass energies of 300 GeV and 320 GeV at HERA. The resonance has a mass of 3099 \\pm 3 (stat.) \\pm 5 (syst.) MeV and a measured Gaussian width of 12 \\pm 3 (stat.) MeV, compatible with the experimental resolution. The resonance is interpreted as an anti-charmed baryon with a minimal constituent quark composition of uuddcbar, together with the charge conjugate.

  13. China Hikes Refined Products Price to Narrow Gap

    Institute of Scientific and Technical Information of China (English)

    Dai Yanling

    2006-01-01

    @@ Rising international prices and China's increasing demand for oil, fueled by the country's fast economic growth, prompted it to hike the price of processed petroleum fuels several times in recent months. The price of gasoline, diesel and aviation kerosene jumped 500 yuan(62.4 U.S. dollars) per ton in late-May. The price increase,the second in the last two months, aims to narrow the gap between international oil prices and domestic prices, a spokesperson with the National Development and Reform Commission (NDRC), the industry watchdog, recently told news media.

  14. The Meteorology of Storms that Produce Narrow Bipolar Events

    Science.gov (United States)

    Lang, Timothy; McCaul, Bill; Fuchs, Brody; Cummer, Steve

    2013-01-01

    Narrow Bipolar Event's (NBE) are compact ( 10 kW in VHF), and impulsive (approx 10 micro s) electrical discharges in thunderstorms, also known as compact intracloud discharges (CIDs). Can be either positive or negative polarity and have distinctive broadband waveform signatures sometimes confused for +CGs in the past by NLDN and other networks. NBEs are related to lightning but are likely optically "dark". As revealed by VHF sensors (both satellite and ground): (1) The most powerful lightning-­-related VHF sources observed (2) Tend to occur at the beginning of intracloud discharges (3) Difficult to estimate altitude properly due to receiver saturation.

  15. The Dolichoarteriopathia of Common Carotid Artery Narrowing the Airway

    Directory of Open Access Journals (Sweden)

    Erkan Eski

    2013-01-01

    Full Text Available Tortuousity of the common carotid artery is rarely seen in otorinolaryngologic  practice. In this report, a case of tortuous common carotid artery narrowing the airway and indenting the epiglottis is presented. In endoscopic examination, pulsating bulge at the level of right lateral farengeal wall, pyriform sinus and larynx was found in a 73 year-old female. Computerized tomographic scan showed tortuous  right common carotid artery bulging the submucosal area of the oropharynx and pyriform sinus. Awareness of the tortuous common carotid artery before any  laryngologic surgical intervention is very important to prevent serious complications.

  16. Are Narrow Line Seyfert 1 Galaxies Viewed Pole-on?

    Science.gov (United States)

    2011-04-01

    0.2’’ respectively. Figure 1 displays the position of each slit over a Barbosa et al. (2009) GMOS IFU image of the [S III] flux (which originates...C. Winge, H. Schmitt: Gemini/ GMOS IFU gas velocity ’tomography’ of the narrow line region of nearby active galaxies, MNRAS, 396 (2009) 2. [2] D...1995) 81. 4 P o S ( N L S 1 ) 0 5 0 Are NLS1s Pole-on? Travis C. Fischer 5 Figure 1: NGC 4051 GMOS IFU image showing integrated [SIII] flux

  17. RESPONSE OF NONLINEAR OSCILLATOR UNDER NARROW-BAND RANDOM EXCITATION

    Institute of Scientific and Technical Information of China (English)

    戎海武; 王向东; 孟光; 徐伟; 方同

    2003-01-01

    The principal resonance of Duffing oscillator to narrow-band random parametricexcitation was investigated. The method of multiple scales was used to determine theequations of modulation of amplitude and phase. The behavior, stability and bifurcation ofsteady state response were studied by means of qualitative analyses. The effects of damping,detuning, bandwidth and magnitudes of deterministic and random excitations wereanalyzed. The theoretical analyses were verified by numerical results. Theoretical analysesand numerical simulations show that when the intensity of the random excitation increases,the nontrivial steady state solution may change from a limit cycle to a diffused limit cycle.Under some conditions the system may have two ,steady state solutions.

  18. Theory of polaron bandwidth narrowing in organic molecular crystals

    Science.gov (United States)

    Hannewald, K.; Stojanović, V. M.; Schellekens, J. M.; Bobbert, P. A.; Kresse, G.; Hafner, J.

    2004-02-01

    We present a theoretical description of polaron bandwidth narrowing in organic molecular crystals. Based on a solution of a Holstein-Peierls model for tightly bound electrons interacting with phonons, an explicit expression for the temperature dependence of the electronic bandwidths is found. This formula generalizes the result of Holstein polaron theory by treating local and nonlocal electron-phonon coupling on equal footing. The usefulness of the method is demonstrated by model studies for oligo-acene crystals from which microscopic insight into the relevance of the different coupling mechanisms is obtained.

  19. Oscillatory quantum interference effects in narrow-gap semiconductor heterostructures

    Science.gov (United States)

    Lillianfeld, R. B.; Kallaher, R. L.; Heremans, J. J.; Chen, Hong; Goel, N.; Chung, S. J.; Santos, M. B.; Van Roy, W.; Borghs, G.

    2010-01-01

    We investigate quantum interference phenomena in narrow bandgap semiconductors under strong spin-orbit interaction, by measuring the magnetoresistance across mesoscopic closed-path structures fabricated in two-dimensional electron systems. We discuss our results in terms of four quantum interference effects brought about by geometric phases acquired by the electron wave functions: the Aharonov-Bohm phase, the Altshuler-Aronov-Spivak effect, the Berry's phase due to the evolution of the spin degree of freedom, and the Aharonov-Casher phase.

  20. Forced motion of an elastic filament through a narrow tube

    Science.gov (United States)

    Freund, L. B.

    2015-12-01

    A polymer filament consisting of many similar molecules linked in a one-dimensional array is very flexible. As a result, shapes with a relatively large curvature can be accommodated elastically. When loosely confined in a thermal environment, such a flexible strand may become tangled owing to its flexibility. When confined within a narrow "tube" over its full length, a flexible molecule may behave quite differently. Here, we consider the qualitative nature of deformation of an individual filament when confined within a tube. Commonly the tube is formed within the cluster by a large number of surrounding filaments of the same type.

  1. Reference Values for Peak Exercise Cardiac Output in Healthy Individuals.

    Science.gov (United States)

    Agostoni, Piergiuseppe; Vignati, Carlo; Gentile, Piero; Boiti, Costanza; Farina, Stefania; Salvioni, Elisabetta; Mapelli, Massimo; Magrì, Damiano; Paolillo, Stefania; Corrieri, Nicoletta; Sinagra, Gianfranco; Cattadori, Gaia

    2017-06-01

    Cardiac output (Q˙) is a key parameter in the assessment of cardiac function, its measurement being crucial for the diagnosis, treatment, and prognostic evaluation of all heart diseases. Until recently, Q˙ determination at peak exercise has been possible through invasive methods, so that normal values were obtained in studies based on small populations. Nowadays, peak Q˙ can be measured noninvasively by means of the inert gas rebreathing (IGR) technique. The present study was undertaken to provide reference values for peak Q˙ in the normal general population and to obtain a formula able to estimate peak exercise Q˙ from measured peak oxygen uptake (V˙o2). We studied 500 normal subjects (age, 44.9 ± 1.5 years; range, 18-77 years; 260 men, 240 women) who underwent a maximal cardiopulmonary exercise test with peak Q˙ measurement by IGR. In the overall study sample, peak Q˙ was 13.2 ± 3.5 L/min (men, 15.3 ± 3.3 L/min; women, 11.0 ± 2.0 L/min; P exercise was (4.4 × peak V˙o2) + 4.3 in the overall study cohort, (4.3 × peak V˙o2) + 4.5 in men, and (4.9 × peak V˙o2) + 3.6 in women. The simultaneous measurement of Q˙ and V˙o2 at peak exercise in a large sample of healthy subjects provided an equation to predict peak Q˙ from peak V˙o2 values. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  2. Statistical connection of peak counts to power spectrum and moments in weak-lensing field

    Science.gov (United States)

    Shirasaki, Masato

    2017-02-01

    The number density of local maxima of weak-lensing field, referred to as weak-lensing peak counts, can be used as a cosmological probe. However, its relevant cosmological information is still unclear. We study the relationship between the peak counts and other statistics in weak-lensing field by using 1000 ray-tracing simulations. We construct a local transformation of lensing field K to a new Gaussian field y, named local-Gaussianized transformation. We calibrate the transformation with numerical simulations so that the one-point distribution and the power spectrum of K can be reproduced from a single Gaussian field y and monotonic relation between y and K. Therefore, the correct information of two-point clustering and any order of moments in weak-lensing field should be preserved under local-Gaussianized transformation. We then examine if local-Gaussianized transformation can predict weak-lensing peak counts in simulations. The local-Gaussianized transformation is insufficient to explain weak-lensing peak counts in the absence of shape noise. The prediction by local-Gaussianized transformation underestimates the simulated peak counts with a level of ˜20-30 per cent over a wide range of peak heights. Local-Gaussianized transformation can predict the weak-lensing peak counts with an ˜10 per cent accuracy in the presence of shape noise. Our analyses suggest that the cosmological information beyond power spectrum and its moments would be necessary to predict the weak-lensing peak counts with a percent-level accuracy, which is an expected statistical uncertainty in upcoming wide-field galaxy surveys.

  3. Defect-controlled vortex generation in current-carrying narrow superconducting strips

    Science.gov (United States)

    Vodolazov, D. Yu; Ilin, K.; Merker, M.; Siegel, M.

    2016-02-01

    We experimentally study the effect of a single circular hole on the critical current I c of narrow superconducting strip with width W much smaller than Pearl penetration depth Λ. We found non-monotonous dependence of I c on the location of a hole across the strip and a weak dependence of I c on the radius of a hole in the case of a hole with ξ \\ll R\\ll W (ξ is a superconducting coherence length) which is placed in the center of strip. The observed effects are caused by competition of two mechanisms of destruction of superconductivity—the entrance of vortex via the edge of the strip and the nucleation of the vortex-antivortex pair near the hole. The mechanisms are clearly distinguishable by a difference in dependence of I c on weak magnetic field.

  4. Are the Narrow Line Regions in Active Galaxies Dusty and Radiation Pressure Dominated?

    CERN Document Server

    Dopita, M A; Sutherland, R S; Binette, L; Cecil, G N

    2002-01-01

    The remarkable similarity between emission spectra of narrow line regions (NLR) in Seyfert Galaxies has long presented a mystery. In photoionization models, this similarity implies that the ionization parameter is nearly always the same, about U ~ 0.01. Here we present dusty, radiation-pressure dominated photoionization models that can provide natural physical insight into this problem. In these models, dust and the radiation pressure acting on it provide the controlling factor in moderating the density, excitation and surface brightness of photoionized NLR structures. Additionally, photoelectric heating by the dust is important in determining the temperature structure of the models. These models can also explain the coexistence of the low-, intermediate- and coronal ionization zones within a single self-consistent physical structure. The radiation pressure acting on dust may also be capable of driving the fast (~3000 km/s) outflows such as are seen in the HST observations of NGC 1068.

  5. Rotating arc horizontal narrow gap welding of high strength quenched and tempered steel

    Institute of Scientific and Technical Information of China (English)

    Guo Ning; Yang Chunli; Han Yanfei; Jia Chuanbao; Du Yongpeng; Zhang Linlin

    2010-01-01

    Rotating arc horizontal narrow gap welding of quenched & tempered ( Q&T) steel was innovatively performed for solving the bottleneck that the molten pool sagged due to the gravity. The shapely multilayer single pass horizontal joint could be obtained by using the rotating arc welding process. The cold crack was not observed in the joint without controlling the heat input and selecting the consumables intentionally. Mkrostructure of the joint could be divided into three zones:base metal zone ( BMZ) , heat-affected zone (HAZ) and weld zone ( WZ). Because of the characteristic of the rotating arc horizontal welding process, the defects in the joints were slag inclusion formed at the inUrlayer of lower side wall. The tensile strength and hardness of HAZ and WZ were larger than those of BMZ. The impact toughness in WZ, HAZ and BM at 0℃ is equal to 115, 212 and 236 J, respectively.

  6. Fluorescence line-narrowing studies of rare earths in disordered solids

    Energy Technology Data Exchange (ETDEWEB)

    Hall, D.W.

    1982-08-10

    This dissertation is made up of two experimental studies dealing with apparently diverse topics within the subject of rare earths (RE) in solids. The first study, described in Part II, concerns the vibrations of a disordered host material about an optically active rare-earth ion as manifested by vibrationally-assisted-electronic, or vibronic transitions. Part III of the dissertation describes an investigation of the influence of site anisotropy on the purely electronic, laser transition of Nd/sup 3 +/ in glass. These two studies are bound together by the common experimental technique of laser-induced fluorescence line narrowing (FLN). By exciting fluorescence with monochromatic light of well-characterized polarization, one may select and observe the response of a single subset of the optically active ions and obtain information that is usually masked by the inhomogeneous nature of disordered solids.

  7. Extremely narrow spectrum of GRB110920A: further evidence for localised, subphotospheric dissipation

    CERN Document Server

    Iyyani, S; Ahlgren, B; Burgess, J M; Larsson, J; Pe'er, A; Lundman, C; Axelsson, M; McGlynn, S

    2015-01-01

    Much evidence points towards that the photosphere in the relativistic outflow in GRBs plays an important role in shaping the observed MeV spectrum. However, it is unclear whether the spectrum is fully produced by the photosphere or whether a substantial part of the spectrum is added by processes far above the photosphere. Here we make a detailed study of the $\\gamma-$ray emission from single pulse GRB110920A which has a spectrum that becomes extremely narrow towards the end of the burst. We show that the emission can be interpreted as Comptonisation of thermal photons by cold electrons in an unmagnetised outflow at an optical depth of $\\tau \\sim 20$. The electrons receive their energy by a local dissipation occurring close to the saturation radius. The main spectral component of GRB110920A and its evolution is thus, in this interpretation, fully explained by the emission from the photosphere including localised dissipation at high optical depths.

  8. High-power narrow-vertical-divergence photonic band crystal laser diodes with optimized epitaxial structure

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Lei; Qu, Hongwei; Liu, Yun; Zhang, Yejin; Zheng, Wanhua, E-mail: whzheng@red.semi.ac.cn [State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, CAS, Beijing 100083 (China); Laboratory of Solid State Optoelectronics Information Technology, Institute of Semiconductors, CAS, Beijing 100083 (China); Wang, Yufei; Qi, Aiyi [Laboratory of Solid State Optoelectronics Information Technology, Institute of Semiconductors, CAS, Beijing 100083 (China)

    2014-12-08

    900 nm longitudinal photonic band crystal (PBC) laser diodes with optimized epitaxial structure are fabricated. With a same calculated fundamental-mode divergence, stronger mode discrimination is achieved by a quasi-periodic index modulation in the PBC waveguide than a periodic one. Experiments show that the introduction of over 5.5 μm-thick PBC waveguide contributes to only 10% increment of the internal loss for the laser diodes. For broad area PBC lasers, output powers of 5.75 W under continuous wave test and over 10 W under quasi-continuous wave test are reported. The vertical divergence angles are 10.5° at full width at half maximum and 21.3° with 95% power content, in conformity with the simulated angles. Such device shows a prospect for high-power narrow-vertical-divergence laser emission from single diode laser and laser bar.

  9. Boundary-Layer Effects on Acoustic Transmission Through Narrow Slit Cavities

    Science.gov (United States)

    Ward, G. P.; Lovelock, R. K.; Murray, A. R. J.; Hibbins, A. P.; Sambles, J. R.; Smith, J. D.

    2015-07-01

    We explore the slit-width dependence of the resonant transmission of sound in air through both a slit array formed of aluminum slats and a single open-ended slit cavity in an aluminum plate. Our experimental results accord well with Lord Rayleigh's theory concerning how thin viscous and thermal boundary layers at a slit's walls affect the acoustic wave across the whole slit cavity. By measuring accurately the frequencies of the Fabry-Perot-like cavity resonances, we find a significant 5% reduction in the effective speed of sound through the slits when an individual viscous boundary layer occupies only 5% of the total slit width. Importantly, this effect is true for any airborne slit cavity, with the reduction being achieved despite the slit width being on a far larger scale than an individual boundary layer's thickness. This work demonstrates that the recent prevalent loss-free treatment of narrow slit cavities within acoustic metamaterials is unrealistic.

  10. Narrow-gap semiconducting properties of KMgBi with multiband feature

    Science.gov (United States)

    Zhang, Xiao; Sun, Shanshan; Lei, Hechang

    2017-01-01

    KMgBi single crystals have been grown successfully by using the Bi flux method. KMgBi shows a semiconducting behavior with a metal-semiconductor transition in high temperature regions. Moreover, both electron- and hole-type carriers exist in KMgBi with a strong temperature dependence of carrier concentrations and mobilities. These results suggest that KMgBi is a narrow-band semiconductor with multiband features in the bulk rather than a semimetal as predicted theoretically. On the other hand, KMgBi exhibits a resistivity plateau in low temperature regions, similar to other topological insulators. It implies that there might be a nontrivial topological surface state in KMgBi.

  11. Fast-tuning narrow-linewidth all polarization-maintaining fiber ring laser

    Science.gov (United States)

    Meng, Zhou; Hu, Zhengliang; Hu, Yongming; Xiong, Shuidong; Cao, Chunyan

    2007-04-01

    This paper describes the structure and operation of a stable, fast-tuning, narrow-linewidth, all polarization-maintaining fibre ring laser using erbium-doped fibre as a saturable absorber. The optimum pump power for single-mode operation in the laser is identified. Laser output power is ~4.0mW at 1536nm for a pump power of 80mW, the polarization extinction ratio is 25.0dB, the SNR is larger than 60dB, the relative intensity noise is below -118dB/Hz at frequencies above 90kHz. The phase noise achieves -107dB at 1kHz while the modulation frequency of lasing optical frequency is 12.5kHz.

  12. Narrow-bandwidth solar upconversion: design principles, efficiency limits, and case studies

    CERN Document Server

    Briggs, Justin A; Dionne, Jennifer A

    2013-01-01

    We employ a detailed balance approach to model a single-junction solar cell with a realistic narrow-band, non-unity-quantum-yield upconverter. As upconverter bandwidths are increased from 0 to 0.5 eV, maximum cell efficiencies increase from the Shockley-Queisser limit of 30.58% to over 43%. Such efficiency enhancements are calculated for upconverters with near-infrared spectral absorption bands, readily accessible with existing upconverters. While our model shows that current bimolecular and lanthanide-based upconverting materials will improve cell efficiencies by <1%, cell efficiencies can increase by several absolute percent with increased upconverter quantum yield - even without an increased absorption bandwidth. By examining the efficiency limits of a highly realistic solar cell-upconverter system, our model provides a platform for optimizing future solar upconverter designs.

  13. Frontal Plane Modelling of Human Dynamics during Standing in Narrow-Stance

    Science.gov (United States)

    Sonobe, M.; Yamaguchi, H.; Hino, J.

    2016-09-01

    Standing ride type vehicles like electric skateboards have been developed in recent years. Although these vehicles have advantages as being compact and low cost due to their simple structure, it is necessary to improve the riding quality. Therefore, the system aiding riders to keep their balance on a skateboard by feedback control or feedforward control has been required. To achieve it, a human balance model should be built as simple as possible. In this study, we focus on the human balance modelling during standing when the support surface moves largely. We restricted the model on frontal plane and narrow stance because the restrictions allow us to assume single-degree-of-freedom model. The balance control system is generally assumed as a delayed feedback control system. The model was identified through impulse response test and frequency response test. As a result, we found the phase between acceleration of the skateboard and posture angle become opposite phase in low frequency range.

  14. Usefulness of Chromoendoscopy and Narrow Band Imaging in Barrett's Esophagus

    Directory of Open Access Journals (Sweden)

    Engy Yousry El Sayed

    2014-12-01

    Full Text Available Barrett's esophagus (BE is the most important risk factor for esophageal adenocarcinoma. High resolution magnification endoscopy with Narrow band imaging (NBI facilitates mucosal surface evaluation and may improve the endoscopic diagnosis of Barrett’s esophagus. The aim of this work was to study the diagnostic value of chromo endoscopy versus NBI in detection of Barrett’s esophagus. Patients and methods: Forty patients their conventional white light endoscopy revealed the diagnosis of GERD and showed findings suggestive of Barrett’s esophagus, they were divided into 20 patients underwent chromo endoscopy and 20 patients underwent Narrow band imaging (NBI, The endoscopic results of both groups were compared with the final histo pathological diagnosis. Results: NBI showed higher accuracy than chromo endoscopy 75 % which vs. 70 % P< 0.05 in detection of BE. NBI had an accuracy of 70 and 75 % in type A pattern (round pits with regular microvasculature to predict columnar mucosa without intestinal metaplasia and type B pattern (villous pits with regular microvasculature to predict specialized intestinal metaplasia respectively. Conclusion: NBI is not only helpful in detecting metaplasia but also in differentiating cardiac from intestinal metaplasia, as it allows clear visualization of micro structural and micro vascular patterns.

  15. Superscattering-enhanced narrow band forward scattering antenna

    Science.gov (United States)

    Hu, De-Jiao; Zhang, Zhi-You; Du, Jing-Lei

    2015-10-01

    We present a narrow band forward scattering optical antenna which is based on the excitation of distinctive whispering gallery modes (WGMs). The antenna is composed of three coaxial cylinder layers: a dielectric layer is sandwiched between a metallic core and cladding. Owing to the destructive interference between the scattering of the outer metallic cladding and the WGM in the backward direction, the power flow in the forward direction is increased. Simulation and analysis show that in proper geometry conditions, the cavity can be tuned into a superscattering state. At this state, both the zeroth and the first order of WGM are excited and contribute to the total scattering. It is shown that the power ratio (power towards backward divided by power towards forward) can be enhanced to about 27 times larger than that for a non-resonant position by the superscattering. Owing to the confinement of the cladding to WGMs, the wavelength range of effective forward scattering is considerably narrow (about 15 nm). Project supported by the National Natural Science Foundation of China (Grant No. 61377054), the Collaborative Innovation Foundation of Sichuan University, China (Grant No. XTCX 2013002), and the International Cooperation and Exchange of Science and Technology Project in Sichuan Province, China (Grant No. 2013HH0010).

  16. Superscattering-enhanced narrow band forward scattering antenna

    Institute of Scientific and Technical Information of China (English)

    胡德骄; 张志友; 杜惊雷

    2015-01-01

    We present a narrow band forward scattering optical antenna which is based on the excitation of distinctive whispering gallery modes (WGMs). The antenna is composed of three coaxial cylinder layers:a dielectric layer is sandwiched between a metallic core and cladding. Owing to the destructive interference between the scattering of the outer metallic cladding and the WGM in the backward direction, the power fl ow in the forward direction is increased. Simulation and analysis show that in proper geometry conditions, the cavity can be tuned into a superscattering state. At this state, both the zeroth and the first order of WGM are excited and contribute to the total scattering. It is shown that the power ratio (power towards backward divided by power towards forward ) can be enhanced to about 27 times larger than that for a non-resonant position by the superscattering. Owing to the confinement of the cladding to WGMs, the wavelength range of effective forward scattering is considerably narrow (about 15 nm).

  17. Critical Heat Flux In Inclined Rectangular Narrow Long Channel

    Energy Technology Data Exchange (ETDEWEB)

    J. L. Rempe; S. W. Noh; Y. H. Kim; K. Y. Suh; F.B.Cheung; S. B. Kim

    2005-05-01

    In the TMI-2 accident, the lower part of the reactor pressure vessel had been overheated and then rather rapidly cooled down, as was later identified in a vessel investigation project. This accounted for the possibility of gap cooling feasibility. For this reason, several investigations were performed to determine the critical heat flux (CHF) from the standpoint of invessel retention. The experiments are conducted to investigate the general boiling phenomena, and the triggering mechanism for the CHF in a narrow gap using a 5 x 105 mm2 crevice type heater assembly and de-mineralized water. The test parameters include the gap size of 5 mm, and the surface orientation angles from the downward facing position (180o) to the vertical position (90o). The orientation angle affects the bubble layer and escape from the narrow gap. The CHF is less than that in a shorter channel, compared with the previous experiments having a heated length of 35 mmin the copper test section.

  18. Narrow-band imaging optical chromocolonoscopy: Advantages and limitations

    Institute of Scientific and Technical Information of China (English)

    Fabian Emura; Yutaka Saito; Hiroaki Ikematsu

    2008-01-01

    Narrow-band imaging(NBI)is an innovative optical technology that modifies the center wavelength and bandwidth of an endoscope's light into narrow-band illumination of 415±30 nm.NBI markedly improves capillary pattern contrast and is an in vivo method for visualizing microvessel morphological changes in superficial neoplastic lesions.The scientific basis for NBI is that short wavelength light falls within the hemoglobin absorption band,thereby facilitating clearer visualization of vascular structures.Severalstudies have reported advantages and limitations of NBI colonoscopy in the colorectum.One difficulty in evaluating results,however,has been non-standardization of NBI systems(Sequential and non-sequential).Utilization of NBI technology has been increasing worldwide,but accurate pit pattern analysis and sufficient skill in magnifying colonoscopy are basic fundamentals required for proficiency in NBI diagnosis of colorectal lesions.Modern optical technology without proper image interpretation wastes resources,confuses untrained endoscopists and delays inter institutional validation studies.Training in the principles of"optical image-enhanced endoscopy"is needed to close the gap between technological advancements and their clinical usefulness.Currently available evidence indicates that NBI constitutes an effective and reliable alternative to chromocolonoscopy for in vivo visualization of vascular structures,but further study assessing reproducibility and effectiveness in the colorectum is ongoing at various medical centers.

  19. Defect-induced bandgap narrowing in low-k dielectrics

    Energy Technology Data Exchange (ETDEWEB)

    Guo, X.; Zheng, H.; Shohet, J. L. [Plasma Processing & Technology Laboratory and Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); King, S. W. [Logic Technology Development, Intel Corporation, Hillsboro, Oregon 97124 (United States); Afanas' ev, V. V. [Department of Physics, University of Leuven, B-3001 Leuven (Belgium); Baklanov, M. R.; Marneffe, J.-F. de [IMEC, Kapeldreef 75, B-3001 Leuven (Belgium); Nishi, Y. [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States)

    2015-08-24

    In this work, core-level X-ray photoelectron spectroscopy was utilized to determine the surface bandgap for various porous and non-porous low-k a-SiCOH dielectrics before and after ion sputtering. By examining the onset of inelastic energy loss in O 1s core-level spectra, the gap narrowing was universally found in Ar{sup +} ion sputtered low-k dielectrics. The reduction of the bandgap ranges from 1.3 to 2.2 eV depending on the film composition. We show that the bandgap narrowing in these low-k dielectrics is caused by development of the valence-band tail as evidenced by the presence of additional electronic states above the valence-band maximum. Electron-spin-resonance measurements were made on a-SiCOH films to gain atomic insight into the nature of the sputtering-induced defects and reveal formation of carbon-related defects as the most probable origin of the gap states.

  20. Narrow band imaging of tumors using gold nanoshells

    Science.gov (United States)

    Puvanakrishnan, Priyaveena; Park, Jaesook; Diagaradjane, Parameshwaran; Schwartz, Jon A.; Coleman, Chris L.; Gill-Sharp, Kelly L.; Sang, Kristina L.; Payne, J. Donald; Krishnan, Sunil; Tunnell, James W.

    2009-02-01

    Gold nanoshells (GNS) are a new class of nanoparticles that can be optically tuned to scatter or absorb light from the near-ultraviolet to near-infrared (NIR) region by varying the core (dielectric silica) /shell (gold) ratio. In addition to spectral tunability, GNS are inert and bioconjugatable making them potential labels for in vivo imaging and therapy of tumors. We report the use of GNS as exogenous contrast agents for enhanced visualization of tumors using narrow band imaging (NBI). NBI takes advantage of the strong NIR absorption of GNS to distinguish between blood and nanoshells in the tumor by imaging in narrow wavelength bands in the visible and NIR, respectively. Using tissue-simulating phantoms, we determined the optimum wavelengths to enhance contrast between blood and GNS. We then used the optimum wavelengths for ex-vivo imaging of tumors extracted from human colon cancer xenograft bearing mice injected with GNS. Systemically delivered GNS accumulated passively in tumor xenografts by the enhanced permeability and retention (EPR) effect. Ex-vivo NBI of tumor xenografts demonstrated tumor specific heterogeneous distribution of GNS with a clear distinction from the tumor vasculature. The results of this study demonstrate the feasibility of using GNS as contrast agents to visualize tumors using NBI.