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Sample records for 2 20 kev range

  1. A direct comparison of Ge and Si(Li) detectors in the 2--20 keV range

    SciTech Connect

    Rossington, C.S.; Giauque, R.D.; Jaklevic, J.M.

    1991-10-01

    The spectral response of high purity Ge (HPGe) and lithium-drifted Si (Si(Li)) surface barrier detectors of similar geometry has been measured over a range of x-ray energies under identical experimental conditions. Detector characteristics such as spectral background, escape peak intensity, entrance window absorption, and energy resolution are presented and compared. Although these characteristic have been discussed in the literature previously, this paper represents an attempt to consolidate the information by making comparisons under equivalent experimental conditions for the two types of detectors. A primary goal of the study is a comparison of the two types of detectors for use in x-ray fluorescence applications.

  2. Characterisation of a counting imaging detector for electron detection in the energy range 10-20 keV

    NASA Astrophysics Data System (ADS)

    Moldovan, G.; Sikharulidze, I.; Matheson, J.; Derbyshire, G.; Kirkland, A. I.; Abrahams, J. P.

    2012-07-01

    As part of a feasibility study into the use of novel electron detector for X-ray photoelectron emission microscopes (XPEEM) and related methods, we have characterised the imaging performance of a counting Medipix 2 readout chip bump bonded to a Silicon diode array sensor and directly exposed to electrons in the energy range 10-20 keV. Detective Quantum Efficiency (DQE), Modulation Transfer Function (MTF) and Noise Power Spectra (NPS) are presented, demonstrating very good performance for the case of electrons with an energy of 20 keV. Significant reductions in DQE are observed for electrons with energy of 15 keV and less, down to levels of 20% for electrons of 10 keV.

  3. A study of 2-20 KeV X-rays from the Cygnus region

    NASA Technical Reports Server (NTRS)

    Bleach, R. D.

    1972-01-01

    Two rocket-borne proportional counters, each with 650 sq c, met area and 1.8 x 7.1 deg FWHM rectangular mechanical collimation, surveyed the Cygnus region in the 2 to 20 keV energy range on two occasions. X-ray spectral data gathered on 21 September 1970 from discrete sources in Cygnus are presented. The data from Cyg X-1, Cyg X-2, and Cyg X-3 have sufficient statistical significance to indicate mutually exclusive spectral forms for the three. Upper limits are presented for X-ray intensities above 2 keV for Cyg X-4 and Cyg X-5 (Cygnus loop). A search was made on 9 August 1971 for a diffuse component of X-rays 1.5 keV associated with an interarm region of the galaxy at galactic longitudes in the vicinity of 60 degrees. A statistically significant excess associated with a narrow disk component was detected. Several possible emission models are discussed, with the most likely candidate being a population of unresolvable low luminosity discrete sources.

  4. QUIET-TIME INTERPLANETARY {approx}2-20 keV SUPERHALO ELECTRONS AT SOLAR MINIMUM

    SciTech Connect

    Wang, Linghua; Lin, Robert P.; Salem, Chadi; Pulupa, Marc; Larson, Davin E.; Luhmann, Janet G.; Yoon, Peter H.

    2012-07-01

    We present a statistical survey of {approx}2-20 keV superhalo electrons in the solar wind measured by the SupraThermal Electron instrument on board the two STEREO spacecraft during quiet-time periods from 2007 March through 2009 March at solar minimum. The observed superhalo electrons have a nearly isotropic angular distribution and a power-law spectrum, f{proportional_to}v{sup -{gamma}}, with {gamma} ranging from 5 to 8.7, with nearly half between 6.5 and 7.5, and an average index of 6.69 {+-} 0.90. The observed power-law spectrum varies significantly on a spatial scale of {approx}>0.1 AU and a temporal scale of {approx}>several days. The integrated density of quiet-time superhalo electrons at 2-20 keV ranges from {approx}10{sup -8} cm{sup -3} to 10{sup -6} cm{sup -3}, about 10{sup -9}-10{sup -6} of the solar wind density, and, as well as the power-law spectrum, shows no correlation with solar wind proton density, velocity, or temperature. The density of superhalo electrons appears to show a solar-cycle variation at solar minimum, while the power-law spectral index {gamma} has no solar-cycle variation. These quiet-time superhalo electrons are present even in the absence of any solar activity-e.g., active regions, flares or microflares, type III radio bursts, etc.-suggesting that they may be accelerated by processes such as resonant wave-particle interactions in the interplanetary medium, or possibly by nonthermal processes related to the acceleration of the solar wind such as nanoflares, or by acceleration at the CIR forward shocks.

  5. Parameter estimation of magnetospheric particle distributions in the energy range 20 to 500 keV

    NASA Astrophysics Data System (ADS)

    Torkar, K. M.

    1982-04-01

    A computer program which analyzes the energy spectra of energetic magnetospheric particles is described. The instrument characteristics and experimental design of the geostationary satellite GEOS-2 which provided the raw data are indicated. The program is designed to run on a UNIVAC 1100/81 computer and requires a plotter and a terminal with basic display enhancement features. Three dimensional charts showing the spectral distribution of energetic electrons are included.

  6. Studies on effective atomic numbers for photon energy absorption and electron density of some narcotic drugs in the energy range 1 keV-20 MeV

    NASA Astrophysics Data System (ADS)

    Gounhalli, Shivraj G.; Shantappa, Anil; Hanagodimath, S. M.

    2013-04-01

    Effective atomic numbers for photon energy absorption ZPEA,eff, photon interaction ZPI,eff and for electron density Nel, have been calculated by a direct method in the photon-energy region from 1 keV to 20 MeV for narcotic drugs, such as Heroin (H), Cocaine (CO), Caffeine (CA), Tetrahydrocannabinol (THC), Cannabinol (CBD), Tetrahydrocannabivarin (THCV). The ZPEA,eff, ZPI,eff and Nel values have been found to change with energy and composition of the narcotic drugs. The energy dependence ZPEA,eff, ZPI,eff and Nel is shown graphically. The maximum difference between the values of ZPEA,eff, and ZPI,eff occurs at 30 keV and the significant difference of 2 to 33% for the energy region 5-100 keV for all drugs. The reason for these differences is discussed.

  7. A balloon-borne instrument for high-resolution astrophysical spectroscopy in the 20-8000 keV energy range

    NASA Technical Reports Server (NTRS)

    Paciesas, W. S.; Baker, R.; Boclet, D.; Brown, S.; Cline, T.; Costlow, H.; Durouchoux, P.; Ehrmann, C.; Gehrels, N.; Hameury, J. M.

    1983-01-01

    The Low Energy Gamma ray Spectrometer (LEGS) is designed to perform fine energy resolution measurements of astrophysical sources. The instrument is configured for a particular balloon flight with either of two sets of high purity germanium detectors. In one configuration, the instrument uses an array of three coaxial detectors (effective volume equal to or approximately 230 cubic cm) inside an NaI (T1) shield and collimator (field of view equal to or approximately 16 deg FWHM) and operates in the 80 to 8000 keV energy range. In the other configuration, three planar detectors (effective area equal to or approximately square cm) surrounded by a combination of passive Fe and active NaI for shielding and collimation (field of view equal to or approximately 5 deg x 10 deg FWHM) are optimized for the 20 to 200 keV energy range. In a typical one day balloon flight, LEGS sensitivity limit (3 sigma) for narrow line features is less than or approximately .0008 ph/cm/s square (coaxial array: 80 to 2000 keV) and less than or approximately .0003 ph/square cm/s (planar array: 50 to 150 keV).

  8. Neutron Scattering Cross Sections for Natural Carbon in the Energy Range 2-133 keV

    SciTech Connect

    Gritzay, O; Gnidak, M; Kolotyi, V; Korol, O; Razbudey, V; Venedyktov, V; Richardson, J H; Sale, K

    2006-06-14

    Natural carbon is well known as reactor structure material and at the same time as one of the most important neutron scattering standards, especially at energies less than 2 MeV, where the neutron total and neutron scattering cross sections are essentially identical. The best neutron total cross section experimental data for natural carbon in the range 1-500 keV have uncertainties of 1-4%. However, the difference between these data and those based on R-matrix analysis and used in the ENDF libraries is evident, especially in the energy range 1-60 keV. Experimental data for total scattering neutron cross sections for this element in the energy range 1-200 keV are scanty. The use of the technique of neutron filtered beams developed at the Kyiv Research Reactor makes it possible to reduce the uncertainty of the experimental data and to measure the neutron scattering cross sections on natural carbon in the energy range 2-149 keV with accuracies of 3-6%. Investigations of the neutron scattering cross section on carbon were carried out using 5 filters with energies 2, 3.5, 24, 54 and 133 keV. The neutron scattering cross sections were measured using a detector system covering nearly 2{pi}. The detector consisting of {sup 3}He counters (58 units), was located just above the carbon samples. The {sup 3}He counters (CHM-37, 7 atm, diameter =18 mm, L=50 cm) are placed in five layers (12 or 11 in each layer). To determine the neutron scattering cross section on carbon the relative method of measurement was used. The isotope {sup 208}Pb was used as the standard. The normalization factor, which is a function of detector efficiency, thickness of the carbon samples, thickness of the {sup 208}Pb sample, geometry, etc., for each sample and for each filter energy has been obtained through Monte Carlo calculations by means of the MCNP4C code. The results of measurements of the neutron scattering cross sections at reactor neutron filtered beams with energies in the range 2-133 keV on

  9. Neutron Total Cross Sections of {sup 235}U From Transmission Measurements in the Energy Range 2 keV to 300 keV and Statistical Model Analysis of the Data

    SciTech Connect

    Derrien, H.; Harvey, J.A.; Larson, N.M.; Leal, L.C.; Wright, R.Q.

    2000-05-01

    The average {sup 235}U neutron total cross sections were obtained in the energy range 2 keV to 330 keV from high-resolution transmission measurements of a 0.033 atom/b sample.1 The experimental data were corrected for the contribution of isotope impurities and for resonance self-shielding effects in the sample. The results are in very good agreement with the experimental data of Poenitz et al.4 in the energy range 40 keV to 330 keV and are the only available accurate experimental data in the energy range 2 keV to 40 keV. ENDF/B-VI evaluated data are 1.7% larger. The SAMMY/FITACS code 2 was used for a statistical model analysis of the total cross section, selected fission cross sections and data in the energy range 2 keV to 200 keV. SAMMY/FITACS is an extended version of SAMMY which allows consistent analysis of the experimental data in the resolved and unresolved resonance region. The Reich-Moore resonance parameters were obtained 3 from a SAMMY Bayesian fits of high resolution experimental neutron transmission and partial cross section data below 2.25 keV, and the corresponding average parameters and covariance data were used in the present work as input for the statistical model analysis of the high energy range of the experimental data. The result of the analysis shows that the average resonance parameters obtained from the analysis of the unresolved resonance region are consistent with those obtained in the resolved energy region. Another important result is that ENDF/B-VI capture cross section could be too small by more than 10% in the energy range 10 keV to 200 keV.

  10. NEUTRON TOTAL CROSS SECTIONS OF 235U FROM TRANSMISSION MEASUREMENTS IN THE ENERGY RANGE 2 keV to 300 keV AND STATISTICAL MODEL ANALYSIS OF THE DATA

    SciTech Connect

    Derrien, H.

    2000-05-22

    The average {sup 235}U neutron total cross sections were obtained in the energy range 2 keV to 330 keV from high-resolution transmission measurements of a 0.033 atom/b sample. The experimental data were corrected for the contribution of isotope impurities and for resonance self-shielding effects in the sample. The results are in very good agreement with the experimental data of Poenitz et al. in the energy range 40 keV to 330 keV and are the only available accurate experimental data in the energy range 2 keV to 40 keV. ENDF/B-VI evaluated data are 1.7% larger. The SAMMY/FITACS code was used for a statistical model analysis of the total cross section, selected fission cross sections and {alpha} data in the energy range 2 keV to 200 keV. SAMMY/FITACS is an extended version of SAMMY which allows consistent analysis of the experimental data in the resolved and unresolved resonance region. The Reich-Moore resonance parameters were obtained from a SAMMY Bayesian fits of high resolution experimental neutron transmission and partial cross section data below 2.25 keV, and the corresponding average parameters and covariance data were used in the present work as input for the statistical model analysis of the high energy range of the experimental data. The result of the analysis shows that the average resonance parameters obtained from the analysis of the unresolved resonance region are consistent with those obtained in the resolved energy region. Another important result is that ENDF/B-VI capture cross section could be too small by more than 10% in the energy range 10 keV to 200 keV.

  11. First INTEGRAL Observations of V404 Cygni during the 2015 Outburst: Spectral Behavior in the 20–650 keV Energy Range

    NASA Astrophysics Data System (ADS)

    Roques, Jean-Pierre; Jourdain, Elisabeth; Bazzano, Angela; Fiocchi, Mariateresa; Natalucci, Lorenzo; Ubertini, Pietro

    2015-11-01

    In 2015 June, the source V404 Cygni (= GS2023+38) underwent an extraordinary outburst. We present the results obtained during the first revolution dedicated to this target by the INTEGRAL mission and focus on the spectral behavior in the hard X-ray domain, using both SPI and IBIS instruments. The source exhibits extreme variability and reaches fluxes of several tens of Crab. However, the emission between 20 and 650 keV can be understood in terms of two main components, varying on all the observable timescales, similar to what is observed in the persistent black hole system Cyg X-1. The low-energy component (up to ∼200 keV) presents a rather unusual shape, probably due to the intrinsic source variability. Nonetheless, a satisfactory description is obtained with a Comptonization model, if an unusually hot population of seed photons (kT0 ∼ 7 keV) is introduced. Above this first component, a clear excess extending up to 400–600 keV leads us to investigate a scenario where an additional (cutoff) power law could correspond to the contribution of the jet synchrotron emission, as proposed in Cyg X-1. A search for an annihilation feature did not provide any firm detection, with an upper limit of 2 × 10‑4 ph cm‑2 s‑1 (2σ) for a narrow line centered at 511 keV, on the averaged obtained spectrum. Based on observations with INTEGRAL, an ESA project with instruments and science data center funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Spain, and Switzerland), Czech Republic, and Poland with the participation of Russia and USA.

  12. First INTEGRAL Observations of V404 Cygni during the 2015 Outburst: Spectral Behavior in the 20-650 keV Energy Range

    NASA Astrophysics Data System (ADS)

    Roques, Jean-Pierre; Jourdain, Elisabeth; Bazzano, Angela; Fiocchi, Mariateresa; Natalucci, Lorenzo; Ubertini, Pietro

    2015-11-01

    In 2015 June, the source V404 Cygni (= GS2023+38) underwent an extraordinary outburst. We present the results obtained during the first revolution dedicated to this target by the INTEGRAL mission and focus on the spectral behavior in the hard X-ray domain, using both SPI and IBIS instruments. The source exhibits extreme variability and reaches fluxes of several tens of Crab. However, the emission between 20 and 650 keV can be understood in terms of two main components, varying on all the observable timescales, similar to what is observed in the persistent black hole system Cyg X-1. The low-energy component (up to ˜200 keV) presents a rather unusual shape, probably due to the intrinsic source variability. Nonetheless, a satisfactory description is obtained with a Comptonization model, if an unusually hot population of seed photons (kT0 ˜ 7 keV) is introduced. Above this first component, a clear excess extending up to 400-600 keV leads us to investigate a scenario where an additional (cutoff) power law could correspond to the contribution of the jet synchrotron emission, as proposed in Cyg X-1. A search for an annihilation feature did not provide any firm detection, with an upper limit of 2 × 10-4 ph cm-2 s-1 (2σ) for a narrow line centered at 511 keV, on the averaged obtained spectrum. Based on observations with INTEGRAL, an ESA project with instruments and science data center funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Spain, and Switzerland), Czech Republic, and Poland with the participation of Russia and USA.

  13. Observations of the scatter-free solar-flare electrons in the energy range 20-1000 keV

    NASA Technical Reports Server (NTRS)

    Wang, J. R.; Fisk, L. A.; Lin, R. P.

    1971-01-01

    Observations of the scatter-free electron events from solar active region McMath No. 8905 are presented. The measurements were made on Explorer 33 satellite. The data show that more than 80% of the electrons from these events undergo no or little scattering and that these electrons travel only approximately 1.5 a.u. between the sun and the earth. The duration of these events cannot be accounted fully by velocity dispersion alone. It is suggested that these electrons could be continuously injected into interplanetary medium for a time interval of approximately 2 to 3 minutes. Energy spectra of these electrons are discussed.

  14. Angular distribution of bremsstrahlung produced by electrons with initial energies in the range from 10 to 20 keV incident on thick Ag

    NASA Astrophysics Data System (ADS)

    Gonzales, Daniel; Cavness, Brandon; Williams, Scott

    2012-03-01

    Experimental results are presented comparing the intensities of the thick-target bremsstrahlung produced by electrons with initial energies ranging from 10 to 20 keV incident on Ag, measured at forward angles in the range of 0 to 55 degrees. When the data are corrected for attenuation due to photon absorption within the target, the results indicate that the detected radiation is distributed anisotropically only at photon energies k that are approximately equal to the initial energy of the incident electrons E0. The results of our experiments suggest that, as k/E0->0, the detected radiation essentially becomes isotropic due primarily to the scattering of electrons within the target. Comparison to the theory of Kissel et al. [At. Data Nucl. Data Tables 28, 381 (1983)] suggests that the angular distribution of bremsstrahlung emitted by electrons incident on thick targets is similar to the angular distribution of bremsstrahlung emitted by electrons incident on free-atom targets only when k/E0 1. The experimental data also are in approximate agreement with the angular distribution predictions of the Monte Carlo program PENELOPE.

  15. Neutron Resonance Parameters of 238U and the Calculated Cross Sections from the Reich-Moore Analysis of Experimental Data in the Neutron Energy Range from 0 keV to 20 keV

    SciTech Connect

    Derrien, H

    2005-12-05

    The neutron resonance parameters of {sup 238}U were obtained from a SAMMY analysis of high-resolution neutron transmission measurements and high-resolution capture cross section measurements performed at the Oak Ridge Electron Linear Accelerator (ORELA) in the years 1970-1990, and from more recent transmission and capture cross section measurements performed at the Geel Linear Accelerator (GELINA). Compared with previous evaluations, the energy range for this resonance analysis was extended from 10 to 20 keV, taking advantage of the high resolution of the most recent ORELA transmission measurements. The experimental database and the method of analysis are described in this report. The neutron transmissions and the capture cross sections calculated with the resonance parameters are compared with the experimental data. A description is given of the statistical properties of the resonance parameters and of the recommended values of the average parameters. The new evaluation results in a slight decrease of the effective capture resonance integral and improves the prediction of integral thermal benchmarks by 70 pcm to 200 pcm.

  16. 2-20 ns interframe time 2-frame 6.151 keV x-ray imaging on the recently upgraded Z Accelerator: A progress report

    NASA Astrophysics Data System (ADS)

    Bennett, G. R.; Smith, I. C.; Shores, J. E.; Sinars, D. B.; Robertson, G.; Atherton, B. W.; Jones, M. C.; Porter, J. L.

    2008-10-01

    When used for the production of an x-ray imaging backlighter source on Sandia National Laboratories' recently upgraded 26MA Z Accelerator, the terawatt-class, multikilojoule, 526.57nm Z-Beamlet laser (ZBL) [P. K. Rambo et al., Appl. Opt. 44, 2421 (2005)], in conjunction with the 6.151keV (1s2-1s2p triplet line of He-like Mn) curved-crystal imager [D. B. Sinars et al., Rev. Sci. Instrum. 75, 3672 (2004); G. R. Bennett et al., Rev. Sci. Instrum. 77, 10E322 (2006)], is capable of providing a high quality x radiograph per Z shot for inertial confinement fusion (ICF), complex hydrodynamics, and other high-energy-density physics experiments. For example, this diagnostic has recently afforded microgram-scale mass perturbation measurements on an imploding ignition-scale 1mg ICF capsule [G. R. Bennett et al., Phys. Rev. Lett. 99, 205003 (2007)], where the perturbation was initiated by a surrogate deuterium-tritium (DT) fuel fill tube. Using an angle-time multiplexing technique, ZBL now has the capability to provide two spatially and temporally separated foci in the Z chamber, allowing "two-frame" imaging to be performed, with an interframe time range of 2-20ns. This multiplexing technique allows the full area of the four-pass amplifiers to be used for the two pulses, rather than split the amplifiers effectively into two rectangular sections, with one leg delayed with respect to the other, which would otherwise double the power imposed onto the various optics thereby halving the damage threshold, for the same irradiance on target. The 6.151keV two frame technique has recently been used to image imploding wire arrays, using a 7.3ns interframe time. The diagnostic will soon be converted to operate with p-rather than s-polarized laser light for enhanced laser absorption in the Mn foil, plus other changes (e.g., operation at the possibly brighter 6.181keV Mn 1s2-1s2p singlet line), to increase x-ray yields. Also, a highly sensitive inline multiframe ultrafast (1ns gate time

  17. 2-20 ns interframe time 2-frame 6.151 keV x-ray imaging on the recently upgraded Z Accelerator: A progress report

    SciTech Connect

    Bennett, G. R.; Smith, I. C.; Shores, J. E.; Sinars, D. B.; Robertson, G.; Atherton, B. W.; Jones, M. C.; Porter, J. L.

    2008-10-15

    When used for the production of an x-ray imaging backlighter source on Sandia National Laboratories' recently upgraded 26 MA Z Accelerator, the terawatt-class, multikilojoule, 526.57 nm Z-Beamlet laser (ZBL) [P. K. Rambo et al., Appl. Opt. 44, 2421 (2005)], in conjunction with the 6.151 keV (1s{sup 2}-1s2p triplet line of He-like Mn) curved-crystal imager [D. B. Sinars et al., Rev. Sci. Instrum. 75, 3672 (2004); G. R. Bennett et al., Rev. Sci. Instrum. 77, 10E322 (2006)], is capable of providing a high quality x radiograph per Z shot for inertial confinement fusion (ICF), complex hydrodynamics, and other high-energy-density physics experiments. For example, this diagnostic has recently afforded microgram-scale mass perturbation measurements on an imploding ignition-scale 1 mg ICF capsule [G. R. Bennett et al., Phys. Rev. Lett. 99, 205003 (2007)], where the perturbation was initiated by a surrogate deuterium-tritium (DT) fuel fill tube. Using an angle-time multiplexing technique, ZBL now has the capability to provide two spatially and temporally separated foci in the Z chamber, allowing 'two-frame' imaging to be performed, with an interframe time range of 2-20 ns. This multiplexing technique allows the full area of the four-pass amplifiers to be used for the two pulses, rather than split the amplifiers effectively into two rectangular sections, with one leg delayed with respect to the other, which would otherwise double the power imposed onto the various optics thereby halving the damage threshold, for the same irradiance on target. The 6.151 keV two frame technique has recently been used to image imploding wire arrays, using a 7.3 ns interframe time. The diagnostic will soon be converted to operate with p-rather than s-polarized laser light for enhanced laser absorption in the Mn foil, plus other changes (e.g., operation at the possibly brighter 6.181 keV Mn 1s{sup 2}-1s2p singlet line), to increase x-ray yields. Also, a highly sensitive inline multiframe ultrafast

  18. 2-20 ns interframe time 2-frame 6.151 keV x-ray imaging on the recently upgraded Z Accelerator: a progress report.

    PubMed

    Bennett, G R; Smith, I C; Shores, J E; Sinars, D B; Robertson, G; Atherton, B W; Jones, M C; Porter, J L

    2008-10-01

    When used for the production of an x-ray imaging backlighter source on Sandia National Laboratories' recently upgraded 26 MA Z Accelerator, the terawatt-class, multikilojoule, 526.57 nm Z-Beamlet laser (ZBL) [P. K. Rambo et al., Appl. Opt. 44, 2421 (2005)], in conjunction with the 6.151 keV (1s(2)-1s2p triplet line of He-like Mn) curved-crystal imager [D. B. Sinars et al., Rev. Sci. Instrum. 75, 3672 (2004); G. R. Bennett et al., Rev. Sci. Instrum. 77, 10E322 (2006)], is capable of providing a high quality x radiograph per Z shot for inertial confinement fusion (ICF), complex hydrodynamics, and other high-energy-density physics experiments. For example, this diagnostic has recently afforded microgram-scale mass perturbation measurements on an imploding ignition-scale 1 mg ICF capsule [G. R. Bennett et al., Phys. Rev. Lett. 99, 205003 (2007)], where the perturbation was initiated by a surrogate deuterium-tritium (DT) fuel fill tube. Using an angle-time multiplexing technique, ZBL now has the capability to provide two spatially and temporally separated foci in the Z chamber, allowing "two-frame" imaging to be performed, with an interframe time range of 2-20 ns. This multiplexing technique allows the full area of the four-pass amplifiers to be used for the two pulses, rather than split the amplifiers effectively into two rectangular sections, with one leg delayed with respect to the other, which would otherwise double the power imposed onto the various optics thereby halving the damage threshold, for the same irradiance on target. The 6.151 keV two frame technique has recently been used to image imploding wire arrays, using a 7.3 ns interframe time. The diagnostic will soon be converted to operate with p-rather than s-polarized laser light for enhanced laser absorption in the Mn foil, plus other changes (e.g., operation at the possibly brighter 6.181 keV Mn 1s(2)-1s2p singlet line), to increase x-ray yields. Also, a highly sensitive inline multiframe ultrafast (1 ns

  19. Development of a soft x-ray diffractometer for a wideband multilayer grating with a novel layer structure in the 2-4 keV range

    SciTech Connect

    Imazono, Takashi; Koike, Masato; Kawachi, Tetsuya; Hasegawa, Noboru; Koeda, Masaru; Nagano, Tetsuya; Sasai, Hiroyuki; Oue, Yuki; Yonezawa, Zeno; Kuramoto, Satoshi; Terauchi, Masami; Takahashi, Hideyuki; Handa, Nobuo; Murano, Takanori

    2012-07-11

    We have been developing a wavelength-dispersive soft x-ray spectrograph covering an energy region of 50-4000 eV to attach to a conventional electron microscope. Observation of soft x-ray emission in the 2-4 keV range needs a multilayer coated grating. In order to evaluate the performance of the optical component in the energy region, a goniometric apparatus has been newly developed and the preliminary performance has been tested using synchrotron radiation.

  20. Reference neutron fields of the KIGAM for the neutron energy range between 144 keV and 2.5 MeV

    NASA Astrophysics Data System (ADS)

    Kim, G. D.; Woo, H. J.; Choi, H. W.; Park, J. W.; Trinh, T. A.

    2012-08-01

    The Korea Institute of Geoscience and Mineral Resources (KIGAM) is constructing a reference neutron field facility as a national project. Neutron fields consist of mono-energetic sources of 144 keV, 250 keV, 565 keV, and 2.5 MeV have a fluence range from 102 neutrons/cm2/sec to 103 neutrons/cm2/sec. The systems for the reference neutron fields, such as a duo-plasmatron ion source, a 4-MHz beam bunching system, a neutron chamber, an irradiation room, a neutron time-of-flight (n-TOF) system, a long-counter, and a sample moving system, were designed and fabricated. The neutron energies of the reference neutron fields and their spreads were observed by using the n-TOF system. The neutron fluence was measured by using a long-counter for energies below 1 MeV and a proton-recoil counter for 2.5 MeV. The long-counter efficiency was calibrated by the Japan Atomic Energy Agency (JAEA) which had a traceability of mono-energetic neutron sources to both Japanese and international standards. The efficiency of the proton-recoil counter was obtained by using a calculation with detailed construction information.

  1. Soft x-ray (0.22.0 keV) imager for z-pinch plasma radiation sources

    SciTech Connect

    Failor, B.H.; Qi, N.; Levine, J.S.; Sze, H.; Gullickson, E.M.

    2004-10-01

    Z-pinches can produce intense fluxes of argon K-shell (3 keV) radiation, but typically only a fraction of the load mass near the axis of the pinch radiates in this spectral range. The majority of the mass does not get hot or dense enough to radiate efficiently in the K-shell. We have designed, built, and tested an instrument to image pinch emission, specifically the radial emission profile, at energies below the K-shell in order to track the location of the cooler mass. A gold mirror provides a high-energy cut-off at 2 keV while a transmission grating disperses the incoming radiation and provides a low-energy cutoff at 0.1 keV. A vertical slit images the pinch radiation in the radial direction and the emission profile is recorded with either an extreme ultraviolet-sensitive charge-coupled device camera (time-integrated) or a linear photodiode array ({approx}1 ns time resolution). We present results for the mirror, grating, and system characterization obtained at the Advanced Light Source synchrotron located at Lawrence Berkeley National Laboratory (Berkeley, CA)

  2. Reduction in the intensity of solar X-ray emission in the 2- to 15-keV photon energy range and heating of the solar corona

    SciTech Connect

    Mirzoeva, I. K.

    2013-04-15

    The time profiles of the energy spectra of low-intensity flares and the structure of the thermal background of the soft X-ray component of solar corona emission over the period of January-February, 2003, are investigated using the data of the RHESSI project. A reduction in the intensity of X-ray emission of the solar flares and the corona thermal background in the 2- to 15-keV photon energy range is revealed. The RHESSI data are compared with the data from the Interball-Geotail project. A new mechanism of solar corona heating is proposed on the basis of the results obtained.

  3. Investigation of Methanol Formation Mechanisms in H2O+CH4 Ices Subjected to 5 keV Electrons at a 10-100 K Temperature Range

    NASA Astrophysics Data System (ADS)

    Stelmach, K. B.; Cooper, P. D.

    2014-12-01

    Methane (CH4) and water are one of the most common molecules in both planetary bodies and interstellar dust grains. Another common molecule, methanol (CH3OH), is thought to form in CH4+H2O ices. However, the exact formation mechanisms of methanol from cosmic rays are not well known, especially in the temperatures of interest. Experiments were performed using high energy electrons (5 keV) to irradiate mixtures of 1:10, 1:5, and 1:3 CH4+H2O ices under a temperature range of 10-100 Kelvin with Fourier Transform Infrared (FTIR) spectroscopy being used to identify the products. Isotopologues of the two molecules (D2O and CD4) were used to probe for the mechanisms. Other products were formed as well and their potential mechanisms are identified. The implications of the mechanisms for planetary and interstellar chemistry are discussed.

  4. FISM 2.0: Improved Spectral Range, Resolution, and Accuracy

    NASA Technical Reports Server (NTRS)

    Chamberlin, Phillip C.

    2012-01-01

    The Flare Irradiance Spectral Model (FISM) was first released in 2005 to provide accurate estimates of the solar VUV (0.1-190 nm) irradiance to the Space Weather community. This model was based on TIMED SEE as well as UARS and SORCE SOLSTICE measurements, and was the first model to include a 60 second temporal variation to estimate the variations due to solar flares. Along with flares, FISM also estimates the tradition solar cycle and solar rotational variations over months and decades back to 1947. This model has been highly successful in providing driving inputs to study the affect of solar irradiance variations on the Earth's ionosphere and thermosphere, lunar dust charging, as well as the Martian ionosphere. The second version of FISM, FISM2, is currently being updated to be based on the more accurate SDO/EVE data, which will provide much more accurate estimations in the 0.1-105 nm range, as well as extending the 'daily' model variation up to 300 nm based on the SOLSTICE measurements. with the spectral resolution of SDO/EVE along with SOLSTICE and the TIMED and SORCE XPS 'model' products, the entire range from 0.1-300 nm will also be available at 0.1 nm, allowing FISM2 to be improved a similar 0.1nm spectral bins. FISM also will have a TSI component that will estimate the total radiated energy during flares based on the few TSI flares observed to date. Presented here will be initial results of the FISM2 modeling efforts, as well as some challenges that will need to be overcome in order for FISM2 to accurately model the solar variations on time scales of seconds to decades.

  5. Studies of Transport Properties and Critical Temperature Suppression Mechanism in Yttrium BARIUM(2) COPPER(3) Oxygen(x) Thin Films Irradiated with 20 TO 120 KEV Electrons

    NASA Astrophysics Data System (ADS)

    Lin, Jiunn-Yuan

    1995-11-01

    We present comprehensive studies of the effects of 20 to 120 keV electron irradiation on rm YBa_2Cu_3O_{x} thin films. Above 60 keV, T_{c } of irradiated samples is suppressed accompanied by a significant increase in residual resistivity, while the carrier concentration remains relatively unchanged. The plane oxygen defects produced by irradiation are found to be responsible for T_{c} suppression. The II suppression mechanism is discussed within several theoretical frameworks. Though in qualitative agreement with d-wave pairing symmetry, our results show a T_{c} suppression rate three times as slow as predicted by the theory when resistivity data are used to extract the impurity scattering rate. Alternatively, phase fluctuations theory gives a qualitative description as well. The displacement energy of plane oxygen is found to be 8.3 eV, which corresponds to a threshold electron energy 58 keV. Finally, an empirical relation is proposed to describe the temperature dependence of the Hall coefficient.

  6. An in-vacuum x-ray diffraction microscope for use in the 0.7-2.9 keV range

    SciTech Connect

    Vine, D. J.; Williams, G. J.; Clark, J. N.; Putkunz, C. T.; Abbey, B.; Nugent, K. A.; Pfeifer, M. A.; Legnini, D.; Roehrig, C.; Wrobel, E.; McNulty, I.; Huwald, E.; Riessen, G. van; Peele, A. G.; Beetz, T.; Irwin, J.; Feser, M.; Hornberger, B.

    2012-03-15

    A dedicated in-vacuum coherent x-ray diffraction microscope was installed at the 2-ID-B beamline of the Advanced Photon Source for use with 0.7-2.9 keV x-rays. The instrument can accommodate three common implementations of diffractive imaging; plane wave illumination; defocused-probe (Fresnel diffractive imaging) and scanning (ptychography) using either a pinhole, focused or defocused probe. The microscope design includes active feedback to limit motion of the optics with respect to the sample. Upper bounds on the relative optics-to-sample displacement have been measured to be 5.8 nm(v) and 4.4 nm(h) rms/h using capacitance micrometry and 27 nm/h using x-ray point projection imaging. The stability of the measurement platform and in-vacuum operation allows for long exposure times, high signal-to-noise and large dynamic range two-dimensional intensity measurements to be acquired. Finally, we illustrate the microscope's stability with a recent experimental result.

  7. Mutagenic effect of a keV range N + beam on mammalian cells

    NASA Astrophysics Data System (ADS)

    Feng, Huiyun; Wu, Lijun; Yu, Lixiang; Han, Wei; Liu, Xuelan; Yu, Zengliang

    2005-07-01

    The radiobiological effects of a keV (5-20 keV) range nitrogen ion (N +) beam on mammalian cells were studied, particularly with regard to the induction of mutation in the cell genome. The experiment demonstrated that the 20 keV N + beam, which resulted in cell death to a certain extent, induced a 2-3 fold increase in the mutation rates at the CD59 gene locus of the mammalian A L cells as compared to the control. Within certain fluence ranges (0-6 × 10 14 N +/cm 2), the cell survival displayed a down-up-down pattern which is similar to the phenomenon known as 'hyper-radiosensitivity' manifested under low-dose irradiation; the CD59 mutation rate firstly showed a gradual rise up to a 3-fold increment above the background level as the ion fluence went up to 4 × 10 14 N +/cm 2, after this peak point however, a downtrend appeared though the ion fluence increased further. It was also observed that the fraction of CD59 mutation bears no proportional relation to ion energy in further experiments of mutation induction by N + beams with the incident energies of 5, 10, 15 and 20 keV at the same fluence of 3 × 10 14 N +/cm 2. Analyses of the deletion patterns of chromosome 11 in CD59- mutants induced by 5-20 keV N + beams showed that these ions did not result in large-size chromosome deletions in this mammalian cell system. A preliminary discussion, suggesting that the mutagenic effect of such low-energy ion influx on mammalian cells could result from multiple processes involving direct collision of particles with cellular DNA, and cascade atomic and molecular reactions due to plentiful primary and secondary particles, was also presented. The study provided the first glimpse into the roles low-energy ions may play in inducing mutagenesis in mammalian cells, and results will be of much value in helping people to understand the contribution of low-energy ions to radiological effects of various ionising radiations.

  8. Combined ion (Ar+, 20 keV) and light irradiation of the quenched Fe-8.25 at % Mn alloy. Separation between thermal and radiation induced long-range effects

    NASA Astrophysics Data System (ADS)

    Ovchinnikov, V. V.; Gushchina, N. V.; Bedin, S. A.

    2016-02-01

    Mössbauer and X-ray diffraction investigations of the radiation-induced α → γ phase transformation and short-range-order formation processes in the quenched Fe-8.25 at % Mn alloy under combined exposure (simultaneous visible light and Ar+ 20-keV ion beam irradiation) are carried out. Combined exposure made it possible to fix the target stationary temperature, and hence, the intensity of thermally-stimulated processes; an energy and ion current density could independently be varied in a wide range. As a result, an important contribution of a non-thermal constituent of ion beam exposure to the structural state of alloy was proved. Only in the presence of ion beam, an α → γ (bcc → fcc) phase transformation and accelerated intraphase processes preparing this transformation are observed in the deep layers of the target (about 103 Rp). With allowance for the relatively low level of thermally and radiation-stimulated processes, radiation-dynamic effects associated with propagation of intense post-cascade solitary waves, which can rearrange metastable matters, are considered as the cause of the observed transformations.

  9. The energy spectrum of 20 keV-20 MeV electrons accelerated in large solar flares

    NASA Technical Reports Server (NTRS)

    Lin, R. P.; Mewaldt, R. A.; Van Hollebeke, M. A. I.

    1982-01-01

    IMP 6, 7, and 8 measurements of the energy spectrum of 20 keV to 20 MeV electrons observed from large solar flares are presented. To minimize propagation effects, only events from flares at W30 deg to W90 deg solar longitude are considered. The energy spectra are constructed using the maximum flux observed at each energy. It is shown that these spectra are representative of the spectra of the electrons escaping from the sun over this range of energies. It is found that every event shows the same spectral shape: a double power law with a smooth transition around 100-200 keV and power law exponents of 0.6-2.0 below and 2.4-4.3 above. The more intense the event, the harder the observed spectrum; in certain cases, the spectra are observed to steepen above 3 MeV.

  10. The Hard X-ray 20-40 keV AGN Luminosity Function

    NASA Technical Reports Server (NTRS)

    Beckmann, V.; Soldi, S.; Shrader, C. R.; Gehrels, N.; Produit, N.

    2006-01-01

    We have compiled a complete, significance limited extragalactic sample based on approximately 25,000 deg(sup 2) to a limiting flux of 3 x 10(exp -11) ergs per square centimeter per second. (approximately 7,000 deg(sup 2)) to a flux limit of 10(exp -11) ergs per square centimeter per second)) in the 20 - 40 keV band with INTEGRAL. We have constructed a detailed exposure map to compensate for effects of non-uniform exposure. The flux-number relation is best described by a power-law with a slope of alpha = 1.66 plus or minus 0.11. The integration of the cumulative flux per unit area leads to f(sub 20-40 keV) = 2.6 x 10(exp -10) ergs per square centimeter per second per sr(sup -1) which is about 1% of the known 20-40 keV X-ray background. We present the first luminosity function of AGN in the 20-40 keV energy range, based on 68 extragalactic objects detected by the imager IBIS/ISGRI on-board INTEGRAL. The luminosity function shows a smoothly connected two power-law form, with an index of gamma (sub 1) = 0.9 below, and gamma (sub 2) = 2.2 above the turn-over luminosity of L(sub *), = 4.6 x 10(sup 43) ergs per second. The emissivity of all INTEGRAL AGNs per unit volume is W(sub 20-40keV)(greater than 10(sup 41) ergs per second) = 2.8 x 10(sup 38) ergs per second h(sup 3)(sub 70) Mpc(sup -3). These results are consistent with those derived in the 2-20keV energy band and do not show a significant contribution by Compton-thick objects. Because the sample used in this study is truly local (z(raised bar) = 0.022)), only limited conclusions can be drawn for the evolution of AGNs in this energy band. But the objects explaining the peak in the cosmic X-ray background are likely to be either low luminosity AGN (L(sub x) less than 10(sup 41) ergs per second) or of other type, such as intermediate mass black holes, clusters, and star forming regions.

  11. Attosecond quantum entanglement in neutron Compton scattering from water in the keV range

    NASA Astrophysics Data System (ADS)

    Chatzidimitriou-Dreismann, C. A.

    2006-11-01

    Scattering of neutrons in the 24- 150 keV incident energy range from H2O relative to that of D2O and H2O- D2O mixtures was reported very recently. Studying time-of-flight integrated intensities, the applied experimental procedure appears to be transparent and may open up a novel class of neutron experiments regarding the “anomalous” scattering from protons, firstly observed in our experiment at ISIS in the 5- 100 eV range. The keV-results were analyzed within standard theory, also including (1) multiple scattering and (2) the strong incident-energy dependence of the neutron-proton cross-section σH(E0) in this energy range. The analysis reveals a striking anomalous ratio of scattering intensity of H2O relative to that of D2O of about 20%, thus being in surprisingly good agreement with the earlier results of the original experiment at ISIS.

  12. Analysis of experimental data on neutron-proton scattering in the energy range between 0 and 150 keV

    SciTech Connect

    Babenko, V. A. Petrov, N. M.

    2009-04-15

    Experimental data on neutron-proton scattering in the energy range between 0 and 150 keV are analyzed by using various sets of effective-range parameters. It is shown that, in contrast to the parameters corresponding to the phase shifts of a Nijmegen group, the parameters corresponding to the experimental phase shifts reported by a group from George Washington University (GWU group) lead to very good agreement between the calculated cross sections and their experimental counterparts in the energy region under consideration. On the basis of the experimental value of the cross section for neutron-proton scattering at an energy of 2 keV, the total cross section for neutron-proton scattering at zero energy was found to be {sigma}{sub 0} = 20.428(16) b, which is in very good agreement with a value of {sigma}{sub 0} = 20.423(9) b, which was obtained as the weighted mean of the cross sections presented by Houke and Hurst. It is shown that, in the energy region around several tens of keV units, the effective-range parameters matched with Dilg's cross-section value of {sigma}{sub 0} = 20.491(14) b lead to calculated cross sections whose values are in excess of their experimental counterparts.

  13. Analysis of experimental data on neutron-proton scattering in the energy range between 0 and 150 keV

    NASA Astrophysics Data System (ADS)

    Babenko, V. A.; Petrov, N. M.

    2009-04-01

    Experimental data on neutron-proton scattering in the energy range between 0 and 150 keV are analyzed by using various sets of effective-range parameters. It is shown that, in contrast to the parameters corresponding to the phase shifts of a Nijmegen group, the parameters corresponding to the experimental phase shifts reported by a group from George Washington University (GWU group) lead to very good agreement between the calculated cross sections and their experimental counterparts in the energy region under consideration. On the basis of the experimental value of the cross section for neutron—proton scattering at an energy of 2 keV, the total cross section for neutron-proton scattering at zero energy was found to be σ 0 = 20.428(16) b, which is in very good agreement with a value of σ 0 = 20.423(9) b, which was obtained as the weighted mean of the cross sections presented by Houke and Hurst. It is shown that, in the energy region around several tens of keV units, the effective-range parameters matched with Dilg’s cross-section value of σ 0 = 20.491(14) b lead to calculated cross sections whose values are in excess of their experimental counterparts.

  14. High angular resolution cosmic X-ray astronomy observations in the energy range 0.15-2 keV and XUV observations of nearby stars from an attitude controlled rocket

    NASA Technical Reports Server (NTRS)

    Garmire, G. P.

    1974-01-01

    The construction of a two dimensional focusing Wolter Type I mirror system for X-ray and XUV astronomical observations from an Astrobee F sounding rocket is described. The mirror design goal will have a one degree field, a 20-arc seconds resolution, an effective area of about 50 sq cm at 1 keV and 10 sq cm at 0.25 keV on axis. A star camera provides aspect data to about 15-arc seconds. Two detectors are placed at the focus with an interchange mechanism to allow a detector change during flight. The following specific developments are reported: (1) position sensitive proportional counter development; (2) channel plate multiplier development; (3) telescope mirror development and payload structure; (4) Australian rocket flight results; (5) Comet Kohoutek He I observation; and (6) Vela, Puppis A, and Gem-Mon bright patch observations.

  15. Suppression of repetitive surface exfoliation of Inconel 625 implanted sequentially with helium ions of different energies (20 100 keV)

    NASA Astrophysics Data System (ADS)

    Rao, A. S.; Whitton, J. L.; Kaminsky, M.

    Studies were conducted to explore if the surface exfoliation of Inconel 625, typical for 100 keV 4He + irradiations can be reduced by pre-irradiating the surfaces with helium ions sequentially over the energy range 20 to 50 keV. Polished, polycrystalline Inconel 625 samples were irradiated at 298K and 573K with 4He + at six different energies in the range from 20 to 50 keV in an order of decreasing energies. For each energy the dose was 0.13 C/cm 2, resulting in a total dose of 0.89 C/cm 2. Subsequently, these samples were implanted with 100 keV 4He + to a dose of 1.0 C/cm 2 or 2.0 C/cm 2. The results reveal that the low energy 4He + implants prior to the 100 keV 4He + implant reduce significantly the erosion yield typical for 100-keV 4He + irradiations alone. For 573K these reduced yields are still about one order of magnitude greater than physical sputtering yields.

  16. Evaluation of 238U Resonance Parameters from 0 to 20 keV

    NASA Astrophysics Data System (ADS)

    Derrien, H.; Courcelle, A.; Leal, L. C.; Larson, N.; Santamarina, A.

    2005-05-01

    The neutron resonance parameters of 238U were obtained in the energy range 0 to 20 keV from a sequential SAMMY analysis of the most recent high-resolution neutron transmission and neutron capture cross-section measurements. Special care was taken in the analysis of the lowest s-wave resonances leading to resonance parameters slightly different from those of ENDF/B-VI (Moxon-Sowerby resonance parameters). The resolved-resonance range was extended to 20 keV, taking advantage of the high-resolution neutron transmission data of Harvey and neutron capture data of Macklin et al. Preliminary integral tests were performed with the new resonance parameters; thermal low-enriched benchmark calculations show an improvement of the keff prediction, mainly due to a 1.5% decrease of the capture cross section at 0.0253 eV and about a 0.4% decrease of the effective shielded resonance capture integral.

  17. Evaluation of 238U Resonance Parameters from 0 to 20 keV

    SciTech Connect

    Derrien, H.; Leal, L.C.; Larson, N.; Courcelle, A.; Santamarina, A.

    2005-05-24

    The neutron resonance parameters of 238U were obtained in the energy range 0 to 20 keV from a sequential SAMMY analysis of the most recent high-resolution neutron transmission and neutron capture cross-section measurements. Special care was taken in the analysis of the lowest s-wave resonances leading to resonance parameters slightly different from those of ENDF/B-VI (Moxon-Sowerby resonance parameters). The resolved-resonance range was extended to 20 keV, taking advantage of the high-resolution neutron transmission data of Harvey and neutron capture data of Macklin et al. Preliminary integral tests were performed with the new resonance parameters; thermal low-enriched benchmark calculations show an improvement of the keff prediction, mainly due to a 1.5% decrease of the capture cross section at 0.0253 eV and about a 0.4% decrease of the effective shielded resonance capture integral.

  18. Group delay dispersion measurements in the mid-infrared spectral range of 2-20 µm.

    PubMed

    Habel, Florian; Trubetskov, Michael; Pervak, Vladimir

    2016-07-25

    We present two measurement devices which both allow the direct measurement of the group delay (GD) and group delay dispersion (GDD) of laser optics, covering the near- and mid-infrared (MIR) spectral range from 2 to 20 µm (500-5,000 cm-1). Two different kinds of devices were developed to measure the GDD of multilayer interference coatings. One is a resonant scanning interferometer (RSI) and the other is a white light interferometer (WLI). The WLI is also capable of measuring the GDD in transmission, for instance of bulk material. GDD measurements of a high dispersive mirror for wavelengths from 2.0 to 2.15 µm and one of a multilayer mirror from 8.5 to 12.0 µm are presented. A measurement of a zinc selenide (ZnSe) substrate in transmission was made with the WLI demonstrating the full bandwidth of the device from 1.9 to 20 µm. The comparison of all measurements with their related theoretical values shows a remarkable correspondence. PMID:27464124

  19. Evaluation of Silicon Neutron Resonance Parameters in the Energy Range Thermal to 1800 keV

    SciTech Connect

    Derrien, H.

    2002-09-30

    The evaluation of the neutron cross sections of the three stable isotopes of silicon in the energy range thermal to 20 MeV was performed by Hetrick et al. for ENDF/B-VI (Evaluated Nuclear Data File). Resonance parameters were obtained in the energy range thermal to 1500 keV from a SAMMY analysis of the Oak Ridge National Laboratory experimental neutron transmission data. A new measurement of the capture cross section of natural silicon in the energy range 1 to 700 keV has recently been performed at the Oak Ridge Electron Linear Accelerator. Results of this measurement were used in a SAMMY reevaluation of the resonance parameters, allowing determination of the capture width of a large number of resonances. The experimental data base is described; properties of the resonance parameters are given. For the first time the direct neutron capture component has been taken into account from the calculation by Rauscher et al. in the energy range from thermal to 1 MeV. Results of benchmark calculations are also given. The new evaluation is available in the ENDF/B-VI format.

  20. Complex Refractive Index of Ammonium Nitrate in the 2-20 micron Spectral Range

    NASA Technical Reports Server (NTRS)

    Jarzembski, Maurice A.; Norman, Mark L.; Fuller, Kirk A.; Srivastava, Vandana; Cutten, Dean R.

    2002-01-01

    Using high resolution Fourier Transform Infrared Spectroscopy (FTIR) absorbance/transmittance spectral data for ammonium sulfate (AMS), calcium carbonate (CAC) and ammonium nitrate (AMN), comparisons were made with previously published complex refractive indices data for AMS and CAC to infer experimental parameters to determine the imaginary refractive index for AMN in the infrared wavelength range from 2 to 20 microns. Kramers-Kronig mathematical relations were applied to calculate the real refractive index for the three compositions. Excellent agreement for AMS and CAC with the published values was found, validating the complex refractive indices obtained for AMN. Backscatter calculations using a lognormal size distribution for AMS, AMN, and CAC aerosols were performed to show differences in their backscattered spectra.

  1. Measurement of the {sup 237}Np(n,{gamma}) cross section from 20 meV to 500 keV with a high efficiency, highly segmented 4{pi} BaF{sub 2} detector

    SciTech Connect

    Esch, E.-I.; Bond, E. M.; Bredeweg, T. A.; Couture, A.; Glover, S. E.; Haight, R. C.; Jandel, M.; Kawano, T.; Mertz, A.; O'Donnell, J. M.; Rundberg, R. S.; Schwantes, J. M.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Reifarth, R.; Greife, U.; Hatarik, A. M.; Hatarik, R.

    2008-03-15

    The {sup 237}Np(n,{gamma}){sup 238}Np cross section has been measured in the neutron energy range from 20 meV to 500 keV using the DANCE array at the Los Alamos National Laboratory. This new facility allows experiments with submilligram samples and is therefore well suited to investigate isotopes with half-lives as low as a few hundred days. In this benchmark measurement, only 0.42 mg of {sup 237}Np was sufficient to determine differential cross sections relative to the well-known resonance at 0.5 eV. The thermal cross section was measured to {sigma}{sub 2200m/s}=177{+-}5 barn, {sigma}{sub kT=25.3meV}=167{+-}4 barn and the resonance integral to RI=693{+-}6 barn.

  2. Calibration of semiconductor detectors in the 200-8500 keV range at VNIIM.

    PubMed

    Tereshchenko, Evgeny E; Moiseev, Nikolay

    2012-09-01

    At the ionising radiation department of the D.I. Mendeleyev Institute for Metrology, a semiconductor detector was calibrated in the energy range 200-8500 keV using (n,2γ) and (n,γ) reactions. Separate cylindrical targets (77 mm diameter and 10mm height) were made from mercuric sulphate, sodium chloride and metallic titanium. A (252)Cf spontaneous fission neutron source, placed in 150 mm diameter polyethylene ball, was used to generate thermal neutrons. The optimal target dimensions were determined taking into account the thermal neutron cross-sections and gamma-radiation attenuations in the target materials. The influence of the background radiation induced by neutrons from the walls, floors and ceilings was also taken into account. The shapes of the efficiency curves for point and volume sources in the 200-8500 keV range have been investigated. The experimental results are in good agreement with Monte-Carlo calculations. The emission rate of the 6.13 MeV photons from a (238)Pu-(13)C source was determined with an expanded uncertainty, U(c), of 10% (k=2). PMID:22512978

  3. X-ray mass attenuation coefficients and imaginary components of the atomic form factor of zinc over the energy range of 7.2-15.2 keV

    SciTech Connect

    Rae, Nicholas A.; Chantler, Christopher T.; Barnea, Zwi; Jonge, Martin D. de; Tran, Chanh Q.; Hester, James R.

    2010-02-15

    The x-ray mass attenuation coefficients of zinc are measured in a high-accuracy experiment between 7.2 and 15.2 keV with an absolute accuracy of 0.044% and 0.197%. This is the most accurate determination of any attenuation coefficient on a bending-magnet beamline and reduces the absolute uncertainty by a factor of 3 compared to earlier work by advances in integrated column density determination and the full-foil mapping technique described herein. We define a relative accuracy of 0.006%, which is not the same as either the precision or the absolute accuracy. Relative accuracy is the appropriate parameter for standard implementation of analysis of near-edge spectra. Values of the imaginary components f'' of the x-ray form factor of zinc are derived. Observed differences between the measured mass attenuation coefficients and various theoretical calculations reach a maximum of about 5% at the absorption edge and up to 2% further than 1 keV away from the edge. The measurements invite improvements in the theoretical calculations of mass attenuation coefficients of zinc.

  4. Rise time in 20-32 keV impulsive X-radiation

    NASA Technical Reports Server (NTRS)

    Vorpahl, J. A.; Takakura, T.

    1974-01-01

    A new property of the X-ray impulsive component observed in solar flares is discussed, giving attention to the relation between the slope of the electron power spectrum and the rise time in the 20-32 keV X-ray spike. This particular energy range was chosen because it offered the greatest number of impulsive events while being sufficiently high to avoid contamination by soft X radiation. It is found for the thin-target model that the electron spectrum tends to be softer when the acceleration rate is smaller.

  5. Calibration of SIOM-5FW film in the range of 0.1-4 keV

    SciTech Connect

    Chenais-Popovics, C.; Reverdin, C.; Ioannou, I.

    2006-06-15

    The SIOM-5FW film produced for the sub-keV x-ray detection range was calibrated here in a wide energy range (0.1-4 keV). A single set of parameters valid in the whole measured energy range was determined for the calibration of the Shangai 5F (SIOM-5FW) film from a parametric fit of the data. The sensitivity of the SIOM-5FW film was measured to be four times lower than that of the Kodak DEF film at 2.5 keV photon energy. Modeling of the DEF and SIOM-5FW films provides a good comparison of their sensitivity in the 0.1-10 keV range.

  6. Calibration of SIOM-5FW film in the range of 0.1-4 keV

    NASA Astrophysics Data System (ADS)

    Chenais-Popovics, C.; Reverdin, C.; Ioannou, I.

    2006-06-01

    The SIOM-5FW film produced for the sub-keV x-ray detection range was calibrated here in a wide energy range (0.1-4keV). A single set of parameters valid in the whole measured energy range was determined for the calibration of the Shangai 5F (SIOM-5FW) film from a parametric fit of the data. The sensitivity of the SIOM-5FW film was measured to be four times lower than that of the Kodak DEF film at 2.5keV photon energy. Modeling of the DEF and SIOM-5FW films provides a good comparison of their sensitivity in the 0.1-10keV range.

  7. Photon Counting Detectors for the 1.0 - 2.0 Micron Wavelength Range

    NASA Technical Reports Server (NTRS)

    Krainak, Michael A.

    2004-01-01

    We describe results on the development of greater than 200 micron diameter, single-element photon-counting detectors for the 1-2 micron wavelength range. The technical goals include quantum efficiency in the range 10-70%; detector diameter greater than 200 microns; dark count rate below 100 kilo counts-per-second (cps), and maximum count rate above 10 Mcps.

  8. Evaluation of silicon neutron resonance parameters in the thermal to 1800 keV energy range.

    PubMed

    Derrien, H; Leal, L C; Guber, K H; Larson, N M

    2005-01-01

    Because silicon is a major constituent of concrete and soil, neutron and gamma ray information on silicon is important for reactor shielding and criticality safety calculations. Therefore, much effort was put into the ENDF/B-VI evaluation for the three stable isotopes of silicon. The neutron capture cross section of natural silicon was recently measured at the Oak Ridge Electron Linear Accelerator (ORELA) in the energy range 1-700 keV. Using the ENDF/B-VI evaluation for initial values, a new evaluation of the resonance parameters was performed by adding the results of the ORELA capture measurements to the experimental database. The computer code SAMMY was used for the analysis of the experimental data; the new version of SAMMY allows accurate calculations of the self-shielding and multiple scattering effects in the capture measurements. The accuracy of the radiative capture widths of the resonances was improved by this analysis. Accurate values of the s-, p- and d-wave neutron strength functions were also obtained. Although the resonance capture component of the present evaluation is 2-3 times smaller than that in ENDF/B-VI, the total capture cross section is much larger, at least for energies >250 keV, because the direct capture component contributes values of the same order of magnitude as the resonance component. The direct component was not taken into account in the ENDF/B-VI evaluation and was calculated for the first time in the present evaluation. PMID:16381717

  9. Effective atomic numbers and electron densities of bacteriorhodopsin and its comprising amino acids in the energy range 1 keV-100 GeV

    NASA Astrophysics Data System (ADS)

    Ahmadi, Morteza; Lunscher, Nolan; Yeow, John T. W.

    2013-04-01

    Recently, there has been an interest in fabrication of X-ray sensors based on bacteriorhodopsin, a proton pump protein in cell membrane of Halobacterium salinarium. Therefore, a better understanding of interaction of X-ray photons with bacteriorhodopsin is required. We use WinXCom program to calculate the mass attenuation coefficient of bacteriorhodopsin and its comprising amino acids for photon energies from 1 keV to 100 GeV. These amino acids include alanine, arginine, asparagine, aspartic acid, glutamine, glutamic acid, glycine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, Asx1, Asx2, Glx1 and Glx2. We then use that data to calculate effective atomic number and electron densities for the same range of energy. We also emphasize on two ranges of energies (10-200 keV and 1-20 MeV) in which X-ray imaging and radiotherapy machines work.

  10. Maskless implants of 20 keV Ga{sup +} in thin crystalline silicon on insulator

    SciTech Connect

    Mio, A. M.; D'Arrigo, G.; Rimini, E.; Spinella, C.; Milazzo, R. G.; Peto, L.; Nadzeyka, A.; Bauerdick, S.

    2013-01-28

    A nano-sized ion beam apparatus has been used as maskless lithography to implant 20 keV Ga{sup +} ions into a 26 nm thick silicon crystalline film on insulator. The ion beam, with about 5 nm standard deviation, delivered few hundred ions during a single shot. Circular areas with nominal diameter of 20 or 50 nm were irradiated to a fluence of 5 Multiplication-Sign 10{sup 14}/cm{sup 2}. Transmission electron microscopy evidenced that the damaged regions are characterized by an irregular contour with many disordered filaments. Damage extends across the layer thickness and fast Fourier transform analysis indicates that implantation causes the amorphization of a region which extends beyond the nominal diameter. In situ annealing experiments demonstrated that the disordered filamentary regions disappear in the 250-450 Degree-Sign C temperature range and the interfaces with the surrounding crystalline regions sharpen. A temperature as high as 600 Degree-Sign C is required to fully re-crystallize the amorphous core of the implanted dots. Reordering occurs by multi-orientation lateral solid-phase epitaxial growth and the breaking of (111) and (101) interfaces, due to the formation of twins, triggers a fast crystallization kinetics. Rapid thermal annealing (890 Degree-Sign C-10 s) completely crystallizes the amorphous regions, twins are absent and small cluster of defects remains instead. Preliminary scanning capacitance measurements indicate that the implanted atoms, after crystallization, are electrically active. The implant method is then a viable processing step for the doping of non-bulk fully depleted ultra-thin-body MOSFET.

  11. Ionization at the Noble Gases Ion-Atom Collisions in the 1-7 KeV Energy Range

    NASA Astrophysics Data System (ADS)

    Kikiani, Boris; Chitaladze, Marika; Japaridze, Josif; Kavlashvili, Nana

    2002-10-01

    The absolute total cross sections for production of free electrons, all positive show target gas ions and partial cross sections for production of double charged slow target gas ions at these collisions have been measured. The measurements were carried out by improved transfers electric field ("condenser") and magnetic mass-analyzer methods[1]. It was shown that in the investigated energy range practically there are now slow ions with charged state more than two. Control experiments have been shown that process of electron's liberation from fast particles ("stripping" process) is unlikely in the investigated energy range. Therefore, one can to suppose that total cross sections for productions of free electrons are equal to the total cross sections of ionization of the target gas atoms. For symmetrical pairs of colliding particles (He+ _ He, Ne+ _ Ne , etc) and for pairs He+ _ Ne, Ar+ _ Kr and Kr+ _ Xe values of partial cross-sections are negligible. In the cases of He+ _ Kr and He+ _ Xe pairs value of these partial cross sections increases with colliding energy and reaches about three percent at the energy 4kev. However, in the cases of He+ _ Ar, Na+ _ Ar, Kr, Xe the values of relative portion of the double charged ions in the total amount of slow positive ions are significant (for example in He+ _ Ar collision at the energy of 4kev this portion is about 20-25 percent). Analyzes of the correlation diagrams of the diabetics terms of colliding particles system (MS) [2] show that the electron capture processes are accompanying by simultaneous excitation of auto- ionization states of target gas ions. The decay of these states are responsible for realize of double ionization process of the target gas atoms. 1. B. Kikiani, R.Lomsadze, N. Mosulishvili, Proceedings of Tbilisi State University, Physics, 34, 114, 1999; 2 M. Barat, W.Lichten, Phys. Rev, A6, 211, 1972.

  12. Observations of solar flare photon energy spectra from 20 keV to 7 MeV

    NASA Technical Reports Server (NTRS)

    Yoshimori, M.; Watanabe, H.; Nitta, N.

    1985-01-01

    Solar flare photon energy spectra in the 20 keV to 7 MeV range are derived from the Apr. 1, Apr. 4, apr. 27 and May 13, 1981 flares. The flares were observed with a hard X-ray and a gamma-ray spectrometers on board the Hinotori satellite. The results show that the spectral shape varies from flare to flare and the spectra harden in energies above about 400 keV. Effects of nuclear line emission on the continuum and of higher energy electron bremsstrahlung are considered to explain the spectral hardening.

  13. Neutron total cross section measurements in the energy region from 47 keV to 20 MeV

    SciTech Connect

    Poenitz, W.P.; Whalen, J.F.

    1983-05-01

    Neutron total cross sections were measured for 26 elements. Data were obtained in the energy range from 47 keV to 20 MeV for 11 elements in the range of light-mass fission products. Previously reported measurements for eight heavy and actinide isotopes were extended to 20 MeV. Data were also obtained for Cu (47 keV to 1.4 MeV) and for Sc, Zn, Nd, Hf, and Pt (1.8 to 20 MeV). The present work is part of a continuing effort to provide accurate neutron total cross sections for evaluations and for optical-model parameteriztions. The latter are required for the derivation of other nuclear-data information of importance to applied programs. 37 references.

  14. Anomalous scattering of keV neutrons from H2O and D2O : I. Single scattering events

    NASA Astrophysics Data System (ADS)

    Chatzidimitriou-Dreismann, C. A.; Krzystyniak, M.

    2006-05-01

    Scattering of neutrons in the 24-150 keV incident energy range from H2O relative to that of D2O and H2O-D2O mixtures was reported recently by Moreh et al. This work is related to neutron Compton scattering experiments regarding the 'anomalous' scattering from protons, observed earlier at ISIS by Chatzidimitriou-Dreismann et al in the 5-100 eV range. Here we provide the complete data reduction scheme of time-of-flight integrated intensities measured at keV energy transfers, within the impulse approximation of standard theory and for single scattering events. Current investigations of multiple scattering events and the associated preliminary results are mentioned. Direct application of the theoretical results to the new keV scattering data reveals an anomalous ratio of scattering intensity of H2O relative to that of D2O of about 20%, thus being in good agreement with the earlier results of the original experiment at ISIS.

  15. 20-keV undulators for a 6-GeV storage ring

    SciTech Connect

    Kim, S.H.; Cho, Y.

    1985-10-01

    The main goal of the future 6-GeV electron storage ring is to provide 20-keV fundamental harmonic radiations from insertion devices. Parameter restrictions of REC-vanadium permendur hybrid undulators have been examined. The critical factor is the achieveable minimum gap of the undulator. Variations of the spectral brilliance for different beam parameters are also shown.

  16. The 20 keV undulators for a 6-GeV storage ring

    NASA Astrophysics Data System (ADS)

    Kim, S. H.; Cho, Y.

    The main goal of the future 6-GeV electron storage ring is to provide 20-keV fundamental harmonic radiations from insertion devices. Parameter restrictions of REC-Vanadium permendur hybrid undulators were examined. The critical factor is the achievable minimum gap of the undulator. Variations of the spectral brilliance for different beam parameters are also shown.

  17. Structural changes of surfaces of spacecraft solar array protective glasses being irradiated by 20-keV electrons

    NASA Astrophysics Data System (ADS)

    Khasanshin, R. H.; Novikov, L. S.

    2016-05-01

    When irradiating K-208 and CMG glasses by 20-keV electrons with flux densities of 1010 < φe < 2 × 1011 cm-2 s-1 in vacuum 10-4 Pa, electrostatic discharges accompanied by plasma emission and destruction of glass surfaces were observed. Examination of glasses by atomic force microscopy (AFM) showed significant difference in structural changes of surfaces of K-208 and CMG samples irradiated by equal flux densities within the range from 2.0 × 1010 to 9.0 × 1010 cm-2 s-1 that can be explained by different mechanisms of removal of charge accumulated in glasses. Surface discharges generating channels on surfaces of K-208 and CMG glasses appear when φ ⩾ 7.4 × 1010 cm-2 s-1 and φ ⩾ 8.7 × 1010 cm-2 s-1 respectively. In average, if radiation conditions are the same and φ ⩾ 1.4 × 1011 cm-2 s-1, the channels are 1.5 times deeper in K-208 than in CMG.

  18. Prediction of the spectrum of atmospheric microburst noise in the range 2-20 Hz - Preliminary results

    NASA Technical Reports Server (NTRS)

    Hardin, Jay C.; Pope, D. Stuart

    1989-01-01

    An engineering estimate of the spectrum of atmospheric microburst noise radiation in the range 2-20 Hz is developed. This prediction is obtained via a marriage of standard aeroacoustic theory with a numerical computation of the relevant fluid dynamics. The 'computational aeroacoustics' technique applied here to the interpretation of atmospheric noise measurements is illustrative of a methodology that can now be employed in a wide class of problems.

  19. Preparation for B4C/Mo2C multilayer deposition of alternate multilayer gratings with high efficiency in the 0.5-2.5 keV energy range

    NASA Astrophysics Data System (ADS)

    Choueikani, Fadi; Delmotte, Franck; Bridou, Françoise; Lagarde, Bruno; Mercere, Pascal; Otero, Edwige; Ohresser, Philippe; Polack, François

    2013-03-01

    This paper presents a study of B4C/Mo2C multilayers mirrors with the aim of using it in the achievement of Alternate MultiLayer (AML) grating. Such component allows a high efficiency in the 500-2500 eV energy range for the DEIMOS beamline. Multilayers were deposited on silicon substrate. They are characterized by reflectometry under grazing incidence. Numerical adjustments were performed with a model of two layers in the period without any interfacial. A prototype of AML grating was fabricated and characterized. The efficiency of the first order of diffraction was worth 15% at 1700 eV.

  20. K-(alpha) Radiography at 20-100 keV Using Short-Pulse Lasers

    SciTech Connect

    Park, H S; Chambers, D; Clarke, R; Eagleton, R; Giraldez, E; Goldsack, T; Heathcote, R; Izumi, N; Key, M; King, J; Koch, J; Landen, O L; Mackinnon, A; Nikroo, A; Patel, P; Pasley, J; Remington, B; Robey, H; Snavely, R; Steinman, D; Stephenson, R; Stoeckl, C; Storm, M; Tabak, M; Theobald, W; Town, R J

    2005-08-29

    X-ray radiography is an important tool for diagnosing and imaging planar and convergent hydrodynamics phenomena for laser experiments. Until now, hydrodynamics experiments at Omega and NIF utilize E{sub x-ray} < 9 keV backlighter x-rays emitted by thermal plasmas. However, future experiments will need to diagnose larger and denser targets and will require x-ray probes of energies from 20-100 keV and possibly up to 1 MeV. Hard K-{alpha} x-ray photons can be created through high-energy electron interactions in the target material after irradiation by petawatt-class high-intensity-short-pulse lasers with > 10{sup 17} W/cm{sup 2}. We have performed several experiments on the JanUSP, and the Vulcan 100TW, and Vulcan Petawatt lasers to understand K-{alpha} sources and to test radiography concepts. 1-D radiography using an edge-on foil and 2-D radiography using buried wires and cone-fiber targets were tested. We find that 1-D thin edge-on foils can have imaging resolution better than 10 {micro}m. Micro volume targets produce bright sources with measured conversion efficiency from laser energy to x-ray photons of {approx} 1 x 10{sup -5}. This level of conversion may not be enough for 2-D point projection radiography. A comparison of our experimental measurements of small volume sources with the LSP/PIC simulation show similar K-{alpha} creation profiles but discrepancy in absolute yields.

  1. Study of pp interactions in the momentum range 0.9 to 2.0 GeV/c

    NASA Astrophysics Data System (ADS)

    Shimizu, F.; Koiso, H.; Kubota, Y.; Sai, F.; Sakamoto, S.; Yamamoto, S. S.

    1982-11-01

    pp interactions at 11 momenta in the range 0.9 to 2.0 GeV/ c have been studied. The elastic angular distributions, covering the c.m. angular range 22°-90°, agree in general with Hoshizaki's phase-shift analysis which shows the looping 1D in and 3F 3 amplitudes in the Argand diagram. About 80% of pn π+ events come from the n Δ++ state at all momenta above 1.2 GeV/ c. The behavior of the density matrix elements of the Δ++ show no momentum or angular dependence. A large fraction of pp π0 events also come from the p Δ+ state at all momenta above 1.2 GeV/ c. The behavior of the Δ+ density matrix elements is similar to that for the case of Δ++.

  2. Experimental investigation of the multiple scatter peak of gamma rays in portland cement in the energy range 279-1332 keV

    NASA Astrophysics Data System (ADS)

    Singh, Tejbir; Singh, Parjit S.

    2011-12-01

    The pulse height spectra for different thicknesses of portland cement in the reflected geometry has been recorded with the help of a NaI(Tl) scintillator detector and 2 K MCA card using different gamma-ray sources such as Hg203 (279 keV), Cs137 (662 keV) and Co60 (1173 and 1332 keV). It has been observed that the multiple scatter peak for portland cement appears at 110 (±7) keV in all the spectra irrespective of different incident photon energies in the range 279-1332 keV from different gamma-ray sources. Further, the variation in the intensity of the multiple scatter peak with the thickness of portland cement in the backward semi-cylinders has been investigated.

  3. 12.2-GHz methanol maser MMB follow-up catalogue - IV. Longitude range 20°-60°

    NASA Astrophysics Data System (ADS)

    Breen, S. L.; Ellingsen, S. P.; Caswell, J. L.; Green, J. A.; Voronkov, M. A.; Avison, A.; Fuller, G. A.; Quinn, L. J.

    2016-07-01

    This is the fourth and final instalment of a series of catalogues presenting 12.2-GHz methanol maser observations made towards each of the 6.7-GHz methanol masers detected in the Methanol Multibeam (MMB) survey. This final portion of the survey covers the 20°-60° longitude range, increasing the 12.2-GHz follow-up range to the full MMB coverage of 186° ≥ l ≤ 60° and |b| ≤ 2°. Towards a total of 260 6.7-GHz MMB methanol masers (we were unable to observe five of the MMB sources in this longitude range) we detect 116 12.2-GHz masers counterparts, 64 of which were discovered in this survey. Including data from the literature, we find that there are 12.2-GHz methanol masers towards 47.1 per cent of the 6.7-GHz methanol masers in this portion of the Galaxy. Across the entire MMB survey range, we find a detection rate of 45.3 per cent. We find that the detection rate of 12.2-GHz methanol masers as a function of Galactic longitude is not uniform and there is an excess of masers with broad velocity ranges at longitudes near 30° and 330°. Comparing the occurrence of 12.2-GHz methanol masers with MMB-targeted CO observations has shown that those outflows associated with a 12.2-GHz source have a larger average dynamical time-scale than those associated with only 6.7-GHz methanol masers, supporting the notion that the 12.2-GHz masers are associated with a later phase of high-mass star formation.

  4. Thermal conductivity of highly porous Si in the temperature range 4.2 to 20 K

    PubMed Central

    2014-01-01

    We report on experimental results of the thermal conductivity k of highly porous Si in the temperature range 4.2 to 20 K, obtained using the direct current (dc) method combined with thermal finite element simulations. The reported results are the first in the literature for this temperature range. It was found that porous Si thermal conductivity at these temperatures shows a plateau-like temperature dependence similar to that obtained in glasses, with a constant k value as low as 0.04 W/m.K. This behavior is attributed to the presence of a majority of non-propagating vibrational modes, resulting from the nanoscale fractal structure of the material. By examining the fractal geometry of porous Si and its fractal dimensionality, which was smaller than two for the specific porous Si material used, we propose that a band of fractons (the localized vibrational excitations of a fractal lattice) is responsible for the observed plateau. The above results complement previous results by the authors in the temperature range 20 to 350 K. In this temperature range, a monotonic increase of k with temperature is observed, fitted with simplified classical models. The extremely low thermal conductivity of porous Si, especially at cryogenic temperatures, makes this material an excellent substrate for Si-integrated microcooling devices (micro-coldplate). PACS 61.43.-j; 63.22.-m; 65.8.-g PMID:25114631

  5. Sputtering and surface structure modification of gold thin films deposited onto silicon substrates under the impact of 20-160 keV Ar+ ions

    NASA Astrophysics Data System (ADS)

    Mammeri, S.; Ouichaoui, S.; Ammi, H.; Dib, A.

    2014-10-01

    The induced sputtering and surface state modification of Au thin films bombarded by swift Ar+ ions under normal incident angle have been studied over an energy range of (20-160) keV using three complementary techniques: Rutherford backscattering spectroscopy (RBS), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The sputtering yields determined by RBS measurements using a 2 MeV 4He+ ion beam were found to be consistent with previous data measured within the Ar+ ion energy region E ⩽ 50 keV, which are thus extended to higher bombarding energies. Besides, the SEM and XRD measurements clearly point out that the irradiated Au film surfaces undergo drastic modifications with increasing the Ar+ ion energy, giving rise to the formation of increasingly sized grains of preferred (1 1 1) crystalline orientations. The relevance of different sputtering yield models for describing experimental data is discussed with invoking the observed surface effects induced by the Ar+ ion irradiation.

  6. 20 keV undulators for a 6-GeV storage ring

    SciTech Connect

    Kim, S.H.; Cho, Y.

    1985-01-01

    The main goal of the future 6-GeV electron storage ring is to provide 20-keV fundamental harmonic radiations from insertion devices. Parameter restrictions of REC-vanadium permendur hybrid undulators have been examined. The critical factor is the achievable minimum gap of the undulator. Variations of the spectral brilliance for different beam parameters are also shown. 6 refs., 5 figs.

  7. 2-165 keV observations of active galaxies and the diffuse background

    NASA Technical Reports Server (NTRS)

    Rothschild, R. E.; Baity, W. A.; Gruber, D. E.; Matteson, J. L.; Peterson, L. E.; Mushotzky, R. F.

    1983-01-01

    HEAO 1 spectral observations of 12 active galaxies in the 12-165 keV and 2-50 keV ranges are reported. The spectra of these galaxies in the 2-165 keV range are well represented by a single power law model; within experimental uncertainties a narrow dispersion in power law index attributable to the individual galaxies is observed, while the 2-165 keV luminosities of these galaxies ranged from 3 x 10 to the 43rd to 3 x 10 to the 45th ergs/s. An apparent universality of the spectral form is found which can be interpreted as due to a common electron distribution with a temperature of tens of keV in the Compton scattering region or as a common nonthermal power-law distribution generating the observed flux through synchrotron-Compton processes. The data indicate that relativistic particles are likely to be responsible for the X-rays from cores of active galaxies through synchroton-Compton processes. In addition, it is noted that only weak number evolution, if any at all, is present in active galaxies.

  8. A low background-rate detector for ions in the 5 to 50 keV energy range to be used for radioisotope dating with a small cyclotron

    SciTech Connect

    Friedman, P.G.

    1986-11-25

    Accelerator mass spectrometry in tandem Van de Graaff accelerators has proven successful for radioisotope dating small samples. We are developing a 20 cm diameter 30 to 40 keV cyclotron dedicated to high-sensitivity radioisotope dating, initially for /sup 14/C. At this energy, range and dE/dx methods of particle identification are impossible. Thus arises the difficult problem of reliably detecting 30 to 40 keV /sup 14/C at 10/sup -2/ counts/sec in the high background environment of the cyclotron, where lower energy ions, electrons, and photons bombard the detector at much higher rates. We have developed and tested an inexpensive, generally useful ion detector that allows dark-count rates below 10/sup -4/ counts/sec and excellent background suppression. With the cyclotron tuned near the /sup 13/CH background peak, to the frequency for /sup 14/C, the detector suppresses the background to 6 x 10/sup -4/ counts/sec. For each /sup 14/C ion the detectors grazing-incidence Al/sub 2/O/sub 3/ conversion dynode emits about 20 secondary electrons, which are independently multiplied in separate pores of a microchannel plate. The output signal is proportional to the number of secondary electrons, allowing pulse-height discrimination of background. We have successfully tested the detector with positive /sup 12/C, /sup 23/Na, /sup 39/K, /sup 41/K, /sup 85/Rb, /sup 87/Rb, and /sup 133/Cs at 5 to 40 keV, and with 36 keV negative /sup 12/C and /sup 13/CH. It should detect ions and neutrals of all species, at energies above 5 keV, with good efficiency and excellent background discrimination. Counting efficiency and background discrimination improve with higher ion energy. The detector can be operated at least up to 2 x 10/sup -7/ Torr and be repeatedly exposed to air. The maximum rate is 10/sup 6.4/ ions/sec in pulse counting mode and 10/sup 9.7/ ions/sec in current integrating mode.

  9. Simulations of Microchannel Plate Sensitivity to <20 keV X-rays as a Function of Energy and Incident Angle

    SciTech Connect

    Kruschwitz, Craig; Wu, M.; Rochau, G. A.

    2013-06-13

    We present results of Monte Carlo simulations of microchannel plate (MCP) response to x-rays in the 250 eV to 20 keV energy range as a function of both x-ray energy and impact angle. The model is based on the model presented in Rochau et al. (2006). However, while the Rochau et al. (2006) model was two-dimensional, and their results only went to 5 keV, our results have been expanded to 20 keV, and our model has been incorporated into a three-dimensional Monte Carlo MCP model that we have developed over the past several years (Kruschwitz et al. 2011). X-ray penetration through multiple MCP pore walls is increasingly important above 5 keV. The effect of x-ray penetration through multiple pores on MCP performance was studied and is presented.

  10. Low-background-rate detector for ions in the 5- to 50-keV energy range to be used for radioisotope dating with a small cyclotron

    SciTech Connect

    Friedman, P.G.

    1986-01-01

    Accelerator mass spectrometry in tandem Van de Graaff accelerators has proven successful for radioisotope dating small samples. Small, inexpensive cyclotrons serving this purpose would make the technique accessible to more researchers and inexpensive enough to compare many small samples. To this end, VC Berkeley is developing a 20-cm-diameter, 30- to 40-keV cyclotron dedicated to high-sensitivity radioisotope dating, initially for /sup 14/C. At this energy, range and dE/dx methods of particle identification are impossible. Thus arises the difficult problem of reliably detecting 30- to 40-keV /sup 14/C at 10/sup -1/ counts/sec in the high-background environment of the cyclotron, where lower energy ions, electrons, and photons bombard the detector at much higher rates. To meet this challenge, an inexpensive, generally useful ion detector was developed that allows dark-count rates below 10/sup -4/ counts/sec and excellent background suppression. With the cyclotron tuned near the /sup 13/CH background peak, to the frequency for /sup 14/C, the detector suppresses the background to 6 x 10/sup -4/ counts/sec. For each /sup 14/C ion, the detector's grazing-incidence Al/sub 2/O/sub 3/ conversion dynode emits about 20 secondary electrons, which are independently multiplied in separate pores of a microchannel plate. The output signal is proportional to the number of secondary electrons, allowing pulse-height discrimination of background.

  11. Microchannel plate pinhole camera for 20 to 100 keV x-ray imaging

    SciTech Connect

    Wang, C.L.; Leipelt, G.R.; Nilson, D.G.

    1984-10-03

    We present the design and construction of a sensitive pinhole camera for imaging suprathermal x-rays. Our device is a pinhole camera consisting of four filtered pinholes and microchannel plate electron multiplier for x-ray detection and signal amplification. We report successful imaging of 20, 45, 70, and 100 keV x-ray emissions from the fusion targets at our Novette laser facility. Such imaging reveals features of the transport of hot electrons and provides views deep inside the target.

  12. First direct high-precision energy determination for the 8.4 and 20.7 keV nuclear transitions in 169Tm

    NASA Astrophysics Data System (ADS)

    Inoyatov, A. Kh.; Kovalík, A.; Filosofov, D. V.; Ryšavý, M.; Perevoshchikov, L. L.; Gurov, Yu. B.

    2015-06-01

    Energies of 8410.1 ± 0.4, 20743.9 ± 0.3, and 63121.6 ± 1.2 eV were determined for the 8.4 keV M1 + E2, 20.7 keV M1 + E2, and 63.1 keV E1 nuclear transitions in 169Tm (generated in the EC decay of 169Yb, respectively, by means of the internal conversion electron spectroscopy. The 169Yb sources used were prepared by vacuum evaporation deposition on polycrystalline carbon and platinum foils as well as by ion implantation at 30keV into a polycrystalline aluminum foil. The relevant conversion electron spectra were measured by a high-resolution combined electrostatic electron spectrometer at 7 eV instrumental resoluition. Values of 0.0326(14) and 0.0259(17) were derived from our experimental data for the E2 admixture parameter |δ ( E2/ M1)| for the 8.4 and 20.7 keV transitions, respectively. A possible effect of nuclear structure on multipolarity of the 20.7 keV transition was also investigated.

  13. Calculation of electron-impact rotationally elastic total cross sections for NH{sub 3}, H{sub 2}S, and PH{sub 3} over the energy range from 0.01 eV to 2 keV

    SciTech Connect

    Limbachiya, Chetan; Vinodkumar, Minaxi; Mason, Nigel

    2011-04-15

    This paper report results of calculation of the total cross section Q{sub T} for electron impact on NH{sub 3}, H{sub 2}S, and PH{sub 3} over a wide range of incident energies from 0.01 eV to 2 keV. Total cross sections Q{sub T} (elastic plus electronic excitation) for incident energies below the ionization threshold of the target were calculated using the UK molecular R-matrix code through the Quantemol-N software package and cross sections at higher energies were derived using the spherical complex optical potential formalism. The two methods are found to give self-consistent values where they overlap. The present results are, in general, found to be in good agreement with previous experimental and theoretical results.

  14. Planned investigation of energetic particle populations (approximately 20-500 keV) in the close Martian environment

    NASA Astrophysics Data System (ADS)

    McKenna-Lawlor, S.; Rusznyak, P.; Gringauz, K.; Klimenko, I.; Lutsenko, V.; Verigin, M.; Korth, A.; Richter, A.; Fischer, S.; Polasek, C.

    1995-04-01

    Energetic particle observations made by the Irish SLED instrument on the Phobos 2 spacecraft in 1989 have revealed the presence, within the overall energy range less than 30 keV - greater than 3.2 MeV, of variously located energetic particle populations in the close Marian environment. The signatures of characteristic boundaries have also been recorded for the first time in energetic particles in the distant Martian magnetotail. The new SLED-II instrument on the Mars-94 Mission is designed to study in detail, with 4 pi measurement capability, these and other energetic particle phenomena at Mars, while operating, over an extended period, at low altitudes above the planet.

  15. DNA strand breaks and crosslinks induced by transient anions in the range 2-20 eV

    SciTech Connect

    Luo, Xinglan; Zheng, Yi; Sanche, Léon

    2014-04-21

    The energy dependence of the yields of single and double strand breaks (SSB and DSB) and crosslinks induced by electron impact on plasmid DNA films is measured in the 2-20 eV range. The yield functions exhibit two strong maxima, which are interpreted to result from the formation of core-excited resonances (i.e., transient anions) of the bases, and their decay into the autoionization channel, resulting in π → π{sup *} electronic transitions of the bases followed by electron transfer to the C–O σ{sup *} bond in the phosphate group. Occupancy of the σ{sup *} orbital ruptures the C–O bond of the backbone via dissociative electron attachment, producing a SSB. From a comparison of our results with those of other works, including theoretical calculations and electron-energy-loss spectra of the bases, the 4.6 eV peak in the SSB yield function is attributed to the resonance decay into the lowest electronically excited states of the bases; in particular, those resulting from the transitions 1{sup 3}A{sup ′} (π{sub 2} → π{sub 3}{sup *}) and 1{sup 3}A{sup ″} (n{sub 2} → π{sub 3}{sup *}) of thymine and 1{sup 3}A{sup ′} (π → π{sup *}) of cytosine. The strongest peak at 9.6 eV in the SSB yield function is also associated with electron captured by excited states of the bases, resulting mostly from a multitude of higher-energy π → π{sup *} transitions. The DSB yield function exhibits strong maxima at 6.1 and 9.6 eV. The peak at 9.6 eV is probably related to the same resonance manifold as that leading to SSB, but the other at 6.1 eV may be more restricted to decay into the electronic state 1{sup 3}A{sup ′} (π → π{sup *}) of cytosine via autoionization. The yield function of crosslinks is dominated by a broad peak extending over the 3.6-11.6 eV range with a sharper one at 17.6 eV. The different line shape of the latter function, compared to that of SSB and DSB, appears to be due to the formation of reactive radical sites in the initial supercoiled

  16. DNA strand breaks and crosslinks induced by transient anions in the range 2-20 eV

    NASA Astrophysics Data System (ADS)

    Luo, Xinglan; Zheng, Yi; Sanche, Léon

    2014-04-01

    The energy dependence of the yields of single and double strand breaks (SSB and DSB) and crosslinks induced by electron impact on plasmid DNA films is measured in the 2-20 eV range. The yield functions exhibit two strong maxima, which are interpreted to result from the formation of core-excited resonances (i.e., transient anions) of the bases, and their decay into the autoionization channel, resulting in π → π* electronic transitions of the bases followed by electron transfer to the C-O σ* bond in the phosphate group. Occupancy of the σ* orbital ruptures the C-O bond of the backbone via dissociative electron attachment, producing a SSB. From a comparison of our results with those of other works, including theoretical calculations and electron-energy-loss spectra of the bases, the 4.6 eV peak in the SSB yield function is attributed to the resonance decay into the lowest electronically excited states of the bases; in particular, those resulting from the transitions 13A' (π2 → π3*) and 13A″ (n2 → π3*) of thymine and 13A' (π → π*) of cytosine. The strongest peak at 9.6 eV in the SSB yield function is also associated with electron captured by excited states of the bases, resulting mostly from a multitude of higher-energy π → π* transitions. The DSB yield function exhibits strong maxima at 6.1 and 9.6 eV. The peak at 9.6 eV is probably related to the same resonance manifold as that leading to SSB, but the other at 6.1 eV may be more restricted to decay into the electronic state 13A' (π → π*) of cytosine via autoionization. The yield function of crosslinks is dominated by a broad peak extending over the 3.6-11.6 eV range with a sharper one at 17.6 eV. The different line shape of the latter function, compared to that of SSB and DSB, appears to be due to the formation of reactive radical sites in the initial supercoiled configuration of the plasmid, which react with the circular form (i.e., DNA with a SSB) to produce a crosslink.

  17. MOLECULAR DYNAMICS OF CASCADES OVERLAP IN TUNGSTEN WITH 20-KEV PRIMARY KNOCK-ON ATOMS

    SciTech Connect

    Setyawan, Wahyu; Nandipati, Giridhar; Roche, Kenneth J.; Kurtz, Richard J.; Wirth, Brian D.

    2015-04-16

    Molecular dynamics simulations are performed to investigate the mutual influence of two subsequent cascades in tungsten. The influence is studied using 20-keV primary knock-on atoms, to induce one cascade after another separated by 15 ps, in a lattice temperature of 1025 K (i.e. 0.25 of the melting temperature of the interatomic potential). The center of mass of the vacancies at the peak damage during the cascade is taken as the location of the cascade. The distance between this location to that of the next cascade is taken as the overlap parameter. Empirical fits describing the number of surviving vacancies and interstitial atoms as a function of overlap are presented.

  18. Growth of Sn whiskers after low temperature implantation of 20 keV He or H

    SciTech Connect

    Poker, D.B.; Schubert, J.; Alexandrou, A.; Froehlingsdorf, J.; Stritzker, B.

    1986-01-01

    Single crystalline whiskers have been observed to form on thin films (approx.100 nm) of Sn following implantation of 20-keV H or He at temperatures below 15/sup 0/K. Rapid warming prevented the formation of whiskers, indicating that the growth occurs predominatly during the warming, and not during implantation. Samples that had been warmed rapidly did show whisker growth only after several days in air at room temperature. The adhesion of the films to the substrate is remarkably enhanced by the irradiation, as measured by scratch tests. Thicker films produced progressively fewer whiskers, and none were observed on implanted foils, or films of In, Bi, Zn, or Pb. Possible origins of the driving force for whisker growth are discussed. Whiskers grew on Sn films on all of the substrates that were tested: quartz, sapphire, glass, Si, Cu, stainless steel, and NaCl.

  19. 20-100 keV K(alpha) X-Ray Source Generation by Short Pulse High Intensity Lasers

    SciTech Connect

    Park, H-S; Koch, J A; Landen, O L; Phillips, T W; Goldsack, T

    2003-08-22

    We are studying the feasibility of utilizing K{alpha} x-ray sources in the range of 20 to 100 keV as a backlighters for imaging various stages of implosions and high areal density planar samples driven by the NIF laser facility. The hard x-ray K{alpha} sources are created by relativistic electron plasma interactions in the target material after a radiation by short pulse high intensity lasers. In order to understand K{alpha} source characteristics such as production efficiency and brightness as a function of laser parameters, we have performed experiments using the 10 J, 100 fs JanUSP laser. We utilized single-photon counting spectroscopy and x-ray imaging diagnostics to characterize the K{alpha} source. We find that the K{alpha} conversion efficiency from the laser energy is {approx} 3 x 10{sup -4}.

  20. High-resolution integrated germanium Compton polarimeter for the γ-ray energy range 80 keV-1 MeV

    NASA Astrophysics Data System (ADS)

    Sareen, R. A.; Urban, W.; Barnett, A. R.; Varley, B. J.

    1995-06-01

    Parameters which govern the choice of a detection system to measure the linear polarization of γ rays at low energies are discussed. An integrated polarimeter is described which is constructed from a single crystal of germanium. It is a compact planar device with the sectors defined electrically, and which gives an energy resolution in the add-back mode of 1 keV at 300 keV. Its performance is demonstrated in a series of calibration measurements using both unpolarized radiation from radioactive sources and polarized γ rays from the 168Er(α,2n)170Yb reaction at Eα=25 MeV. Polarization measurements at energies as low as 84 keV have been achieved, where the sensitivity was 0.32±0.09. The sensitivity, efficiency, and energy resolution are reported. Our results indicate that energy resolution should be included in the definition of the figure of merit and we relate the new definition to earlier work. The comparisons show the advantages of the present design in the energy range below 300 keV and its competitiveness up to 1500 keV.

  1. Stability of Extraterrestrial Glycine under Energetic Particle Radiation Estimated from 2 keV Electron Bombardment Experiments

    NASA Astrophysics Data System (ADS)

    Maté, B.; Tanarro, I.; Escribano, R.; Moreno, M. A.; Herrero, V. J.

    2015-06-01

    The destruction of solid glycine under irradiation with 2 keV electrons has been investigated by means of IR spectroscopy. Destruction cross sections, radiolysis yields, and half-life doses were determined for samples at 20, 40, 90, and 300 K. The thickness of the irradiated samples was kept below the estimated penetration depth of the electrons. No significant differences were obtained in the experiments below 90 K, but the destruction cross section at 300 K was larger by a factor of 2. The radiolysis yields and half-life doses are in good accordance with recent MeV proton experiments, which confirms that electrons in the keV range can be used to simulate the effects of cosmic rays if the whole sample is effectively irradiated. In the low temperature experiments, electron irradiation leads to the formation of residues. IR absorptions of these residues are assigned to the presence CO2, CO, OCN-, and CN- and possibly to amide bands I to III. The protection of glycine by water ice is also studied. A water ice film of ˜150 nm is found to provide efficient shielding against the bombardment of 2 keV electrons. The results of this study show also that current Monte Carlo predictions provide a good global description of electron penetration depths. The lifetimes estimated in this work for various environments ranging from the diffuse interstellar medium to the inner solar system, show that the survival of hypothetical primeval glycine from the solar nebula in present solar system bodies is not very likely.

  2. Decline of the 2-10 keV Emission from Eta Carinae

    NASA Technical Reports Server (NTRS)

    Liburd, Jamar; Corcoran, Michael F.; Hamaguchi, Kenji; Gull, Theodore R.; Madura, Thomas; Teodoro, Mairan; Moffat, Anthony; Richardson, Noel; Russell, Chris; Pollock, Andrew; Owocki, Stan

    2014-01-01

    Analysis of Eta Car's X-ray spectrum in the 2-10 keV band using processed data from the X-ray Telescope on Swift reveals a peak flux on July 16, 2014 of 0.046 photons s(exp -1) cm(exp -2) (3.37+/-0.15×10(exp -10) ergs s(exp -1) cm(exp -2). This flux is similar to the previous maximum flux seen by the XRT, 3.53+/-0.13×10(exp -10) ergs s(exp -1) cm(exp -2) (0.049 photons s(exp -1) cm(exp -2), ATEL #6298). Since this peak on July 16, the most recent Swift XRT quicklook data show a drop in flux. On July 20, 2014 the XRT flux as seen in the quicklook data was 0.011 photons s(exp -1) cm(exp -2) (8.3+/-0.5×10(exp -11) ergs s(exp -1) cm(exp -2)). This most likely indicates that the 2-10 keV flux is in its declining phase as Eta Car approaches its deep X-ray minimum stage (Hamaguchi et al., 2014, ApJ, 784, 125) associated with periastron passage of the 2024-day binary orbit. The column density derived from analysis of the July 20 XRT quicklook data is 7.2×10(exp 22) cm(exp -2). This is consistent with the column density seen near the same orbital phase in 2003 (7.7×10(exp 22) cm(exp -2), Hamaguchi et al., 2007, ApJ, 663, 522). Eta Car's deep X-ray minimum phase is expected to begin on July 30, 2014. Weekly Swift/XRT observations of Eta Car in the 2-10 keV band are planned throughout the X-ray minimum.

  3. Optical constants for hard x-ray multilayers over the energy range E = 35 - 180 keV

    NASA Astrophysics Data System (ADS)

    Windt, David L.; Donguy, Soizik; Hailey, Charles J.; Koglin, Jason E.; Honkimaki, Veijo; Ziegler, Eric; Christensen, Finn E.; Harrison, Fiona A.

    2004-02-01

    We have determined experimentally optical constants for eight thin film materials that can be used in hard X-ray multilayer coatings. Thin film samples of Ni.97V.03, Mo, W, Pt, C, B4C, Si and SiC were deposited by magnetron sputtering onto superpolished optical flats. Optical constants were determined from fits to reflectance-vs-incidence angle measurements made using synchrotron radiation over the energy range E=35 180 keV. We have also measured the X-ray reflectance of a prototype W/SiC multilayer coating over the energy range E=35 100 keV, and we compare the measured reflectance with a calculation using the newly derived optical constants.

  4. A DATABASE OF >20 keV ELECTRON GREEN'S FUNCTIONS OF INTERPLANETARY TRANSPORT AT 1 AU

    SciTech Connect

    Agueda, N.; Sanahuja, B.; Vainio, R.

    2012-10-15

    We use interplanetary transport simulations to compute a database of electron Green's functions, i.e., differential intensities resulting at the spacecraft position from an impulsive injection of energetic (>20 keV) electrons close to the Sun, for a large number of values of two standard interplanetary transport parameters: the scattering mean free path and the solar wind speed. The nominal energy channels of the ACE, STEREO, and Wind spacecraft have been used in the interplanetary transport simulations to conceive a unique tool for the study of near-relativistic electron events observed at 1 AU. In this paper, we quantify the characteristic times of the Green's functions (onset and peak time, rise and decay phase duration) as a function of the interplanetary transport conditions. We use the database to calculate the FWHM of the pitch-angle distributions at different times of the event and under different scattering conditions. This allows us to provide a first quantitative result that can be compared with observations, and to assess the validity of the frequently used term beam-like pitch-angle distribution.

  5. Electrostatic spectrometer for measurement of internal conversion electrons in the 0.1-20 keV region

    NASA Astrophysics Data System (ADS)

    Varga, Dezsö; Kádár, Imre; Kövér, Ákos; Cserny, István; Mórik, Gyula; Brabec, Vlastislav; Dragoun, Otokar; Kovalík, Alojz; Adam, Jindřich

    A new second order focusing, n = 1.5 cylindrical mirror electron spectrometer has been built. It enables us to measure the electrons emitted from the radioactive sources in the 0.1-20 keV region with an instrumental energy resolution of 0.1-1%. The ring-shaped input slit serving as a virtual electron optical object together with the large dimensions of the analyser (the total focal length equals 525 mm) allow us to utilize sources up to 1.5 cm 2 area. The spectrometer was adjusted using electron guns and tested also by 57Co and 169Yb radioactive sources prepared by vacuum evaporation and mass separation. The instrument operates automatically at oil-free vacuum of 4 × 10 -6 Pa and the electron spectra are scanned in cycles. The background of the channeltron is about 1.5 counts/min.

  6. Ranges of Channelled keV B Ions in Si Crystals with Impact Parameter Dependent Stopping Power

    NASA Astrophysics Data System (ADS)

    Kabadayi, Önder

    In this study we calculated channelled ion ranges of boron ions by using an impact parameter dependent stopping power model. Impact parameter dependent stopping powers for boron ions penetrating into Si <100> are investigated first for energies from 10 to 150 keV. We assumed that impact parameter dependent stopping powers can be expressed by a modified Oen-Robinson formula [1] (Oen et al. Nucl. Instr. Meth. B132, 647 (1976)). The model is implemented by developing a computer code to solve a differential equation numerically for which mean ion ranges can be obtained. The results are compared with experimental data as well as Crystal-TRIM, SRIM and similar procedures calculating ion ranges in solids. We have found an agreement between our results and literature.

  7. Production and Performance of the InFOCmicronS 20-40 keV Graded Multilayer Mirror

    NASA Technical Reports Server (NTRS)

    Berendse, F.; Owens, S. M.; Serlemitsos, P. J.; Tueller, J.; Chan, K.-W.; Soong, Y.; Krimm, H.; Baumgartner, W. H.; Tamura, K.; Okajima, T.; Tawara, Y.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    The International Focusing Optics Collaboration for micron Crab Sensitivity (InFOC micronS) balloon-borne hard x-ray incorporates graded multilayer technology to obtain significant effective area at energies previously inaccessible to x-ray optics. The telescope mirror consists of 2040 segmented thin aluminum foils coated with replicated Pt/C multilayers. A sample of these foils was scanned using a pencil-beam reflectometer to determine, multilayer quality. The results of the reflectometer measurements demonstrate our capability to produce large quantity of foils while maintaining high-quality multilayers with a mean Nevot-Croce interface roughness of 0.5nm. We characterize the performance of the complete InFOC micronS telescope with a pencil beam raster scan to determine the effective area and encircled energy function of the telescope. The effective area of the complete telescope is 78, 42 and 22 square centimeters at 20 30 and 40 keV. respectively. The measured encircled energy fraction of the mirror has a half-power diameter of 2.0 plus or minus 0.5 arcmin (90% confidence). The mirror successfully obtained an image of the accreting black hole Cygnus X-1 during a balloon flight in July, 2001. The successful completion and flight test of this telescope demonstrates that graded-multilayer telescopes can be manufactured with high reliability for future x-ray telescope missions such as Constellation-X.

  8. Mechanisms of O2 Sputtering from Water Ice by keV Ions

    NASA Technical Reports Server (NTRS)

    Teolis, B. D.; Vidal, R. A.; Shi, J.; Baragiola, R. A.

    2005-01-01

    We have conducted experiments on the sputtering of water ice by 100 keV Ar(+) between 20 and 150 K. Our findings indicate that the temperature dependence of the total sputtering yield is heavily influenced by the thermal and irradiation history of the ice, showing a complex dependence on irradiation fluence that is correlated to the ejection of O2 molecules. The results suggest that O2 produced by the ions inside the ice diffuses to the surface where it is trapped and then ejected via sputtering or thermal desorption. A high concentration of O2 can trap in a subsurface layer during bombardment at 130 K, which we relate to the formation of hydrogen and its escape from that region. A simple model allows us to determine the depth profile of the absolute concentration of O2 trapped in the ice.

  9. Centaurus A /NGC 5128/ at 2 keV-2.3 MeV - HEAO 1 observations and implications

    NASA Technical Reports Server (NTRS)

    Baity, W. A.; Rothschild, R. E.; Lingenfelter, R. E.; Stein, W. A.; Nolan, P. L.; Gruber, D. E.; Knight, F. K.; Matteson, J. L.; Peterson, L. E.; Mushotzky, R. F.

    1981-01-01

    The active-nucleus galaxy Centaurus A has been studied at 2 keV-2.3 MeV using data from the UCSD/MIT hard X-ray and low-energy gamma-ray instrument and the GSFC/CIT cosmic X-ray experiment on HEAO-1. It is found that an E exp -1.60 + or - 0.03 power law spectrum breaking to E exp -2.0 + or - 0.2 at 140 keV best describes the January and July 1978 data. The average intensity was 50% higher during the January observations. Upper limits to unresolved lines at 511 keV and 1.6 MeV were found to be 6.5 x 10 to the -4th photons/sq cm-s and 2.2 x 10 to the -4th photons/sq cm-s, respectively, at the 90% confidence level. The present data are consistent with the detailed calculations of the synchrotron self-Compton mechanism; they may also agree, marginally, with the predictions of emission from spherical accretion onto black holes.

  10. K+ charge transfer in H2 at low keV collisions

    NASA Astrophysics Data System (ADS)

    Alarcón, F. B.; Martinez, H.; Fuentes, B. E.; Yousif, F. B.

    2013-08-01

    Absolute electron capture cross sections for the K+-H2 pair, employing beam collision spectroscopy for 0.4-4 keV energy were measured. The capture cross section increased with the increase in collision energy. The results below 2 keV overlap with previously measured data of other investigators and extend down in energy to 400 eV, where no previous data have been reported. Experimental data were compared with calculations employing the Olson model, which were found to agree in behavior as well as with an absolute value above 100 keV.

  11. Measurement of the x-ray mass attenuation coefficient and determination of the imaginary component of the atomic form-factor of tin over the energy range of 29 keV-60 keV.

    SciTech Connect

    de Jonge, M. D.; Tran, C. Q.; Chantler, C. T.; Barnea, Z.; Dhal, B. P.; Paterson, D.; Kanter, E. P.; Southworth, S. H.; Young, L.; Beno, M. A.; Linton, J. A.; Jennings, G.; Univ. of Melbourne; Australian Synchrotron Project

    2007-01-01

    We use the x-ray extended-range technique (XERT) [C. T. Chantler et al., Phys. Rev. A 64, 062506 (2001)] to measure the mass attenuation coefficients of tin in the x-ray energy range of 29-60 keV to 0.04-3 % accuracy, and typically in the range 0.1-0.2 %. Measurements made over an extended range of the measurement parameter space are critically examined to identify, quantify, and correct a number of potential experimental systematic errors. These results represent the most extensive experimental data set for tin and include absolute mass attenuation coefficients in the regions of x-ray absorption fine structure, extended x-ray absorption fine structure, and x-ray absorption near-edge structure. The imaginary component of the atomic form factor f{sub 2} is derived from the photoelectric absorption after subtracting calculated Rayleigh and Compton scattering cross sections from the total attenuation. Comparison of the result with tabulations of calculated photoelectric absorption coefficients indicates that differences of 1-2 % persist between calculated and observed values.

  12. Absolute calibration of Kodak Biomax-MS film response to x rays in the 1.5- to 8-keV energy range

    SciTech Connect

    Marshall, F. J.; Knauer, J. P.; Anderson, D.; Schmitt, B. L

    2006-10-15

    The absolute response of Kodak Biomax-MS film to x rays in the range from 1.5- to 8-keV has been measured using a laboratory electron-beam generated x-ray source. The measurements were taken at specific line energies by using Bragg diffraction to produce monochromatic beams of x rays. Multiple exposures were taken on Biomax MS film up to levels exceeding optical densities of 2 as measured by a microdensitometer. The absolute beam intensity for each exposure was measured with a Si(Li) detector. Additional response measurements were taken with Kodak direct exposure film (DEF) so as to compare the results of this technique to previously published calibrations. The Biomax-MS results have been fitted to a semiempirical mathematical model (Knauer et al., these proceedings). Users of the model can infer absolute fluences from observed exposure levels at either interpolated or extrapolated energies. To summarize the results: Biomax MS has comparable sensitivity to DEF film below 3 keV but has reduced sensitivity above 3 keV ({approx}50%). The lower exposure results from thinner emulsion layers, designed for use with phosphor screens. The ease with which Biomax-MS can be used in place of DEF (same format film, same developing process, and comparable sensitivity) makes it a good replacement.

  13. Absolute calibration of Kodak Biomax-MS film response to x rays in the 1.5- to 8-keV energy range

    NASA Astrophysics Data System (ADS)

    Marshall, F. J.; Knauer, J. P.; Anderson, D.; Schmitt, B. L.

    2006-10-01

    The absolute response of Kodak Biomax-MS film to x rays in the range from 1.5- to 8-keV has been measured using a laboratory electron-beam generated x-ray source. The measurements were taken at specific line energies by using Bragg diffraction to produce monochromatic beams of x rays. Multiple exposures were taken on Biomax MS film up to levels exceeding optical densities of 2 as measured by a microdensitometer. The absolute beam intensity for each exposure was measured with a Si (Li) detector. Additional response measurements were taken with Kodak direct exposure film (DEF) so as to compare the results of this technique to previously published calibrations. The Biomax-MS results have been fitted to a semiempirical mathematical model (Knauer et al., these proceedings). Users of the model can infer absolute fluences from observed exposure levels at either interpolated or extrapolated energies. To summarize the results: Biomax MS has comparable sensitivity to DEF film below 3keV but has reduced sensitivity above 3keV (˜50%). The lower exposure results from thinner emulsion layers, designed for use with phosphor screens. The ease with which Biomax-MS can be used in place of DEF (same format film, same developing process, and comparable sensitivity) makes it a good replacement.

  14. The angular distribution of solar wind ˜20-200 keV superhalo electrons at quiet times

    NASA Astrophysics Data System (ADS)

    Yang, Liu; Wang, Linghua; Li, Gang; He, Jiansen; Salem, Chadi S.; Tu, Chuanyi; Wimmer-Schweingruber, Robert F.; Bale, Stuart D.

    2016-03-01

    We present a comprehensive study of the angular distribution of ˜20-200 keV superhalo electrons measured at 1 AU by the WIND 3DP instrument during quiet times from 1995 January through 2005 December. According to the interplanetary magnetic field, we re-bin the observed electron pitch angle distributions to obtain the differential flux, Jout (Jin), of electrons traveling outward from (inward toward) the Sun, and define the anisotropy of superhalo electrons as A =2/(Jo u t-Ji n) Jo u t+Ji n at a given energy. We found that for out in ˜96% of the selected quiet-time samples, superhalo electrons have isotropic angular distributions, while for ˜3% (˜1%) of quiet-time samples, superhalo electrons are outward-anisotropic (inward-anisotropic). All three groups of angular distributions show no correlation with the local solar wind plasma, interplanetary magnetic field and turbulence. Furthermore, the superhalo electron spectral index shows no correlation with the spectral index of local solar wind turbulence. These quiet-time superhalo electrons may be accelerated by nonthermal processes related to the solar wind source and strongly scattered/ reflected in the interplanetary medium, or could be formed due to the electron acceleration through the interplanetary medium.

  15. Thermal expansion and phase changes of 16Kh12V2FTaR steel in temperature range from 20 to 1000 °C

    NASA Astrophysics Data System (ADS)

    Kozlovskii, Yu. M.; Stankus, S. V.; Yatsuk, O. S.; Agazhanov, A. Sh.; Komarov, S. G.; Anufriyev, I. S.

    2014-01-01

    The article presents the results of investigation of thermal expansion of 16Kh12V2FTaR steel in the temperature range 20-1000 °C. Measurements were carried out by dilatometric method with the error (1.5-2)×10-7 K-1. The temperature dependences of thermal coefficient of linear expansion of steel have been obtained in ferrite-martensite and ferrite-perlite states, and reference tables have been calculated. Influence of samples cooling rate on martensite phase formation is shown.

  16. High Spatial Resolution STXM at 6.2 keV Photon Energy

    NASA Astrophysics Data System (ADS)

    Vila-Comamala, Joan; Dierolf, Martin; Kewish, Cameron M.; Thibault, Pierre; Pilvi, Tero; Färm, Elina; Guzenko, Vitaliy; Gorelick, Sergey; Menzel, Andreas; Bunk, Oliver; Ritala, Mikko; Pfeiffer, Franz; David, Christian

    2010-04-01

    We report on a zone-doubling technique that bypasses the electron-beam lithography limitations for the production of X-ray diffractive optics and enables the fabrication of Fresnel zone plates with smaller outermost zone widths than other well-established approaches. We have applied this method to manufacture hard X-ray Fresnel zone plates with outermost zone widths of 25 and 20 nm. These lenses have been tested in scanning transmission X-ray microscopy (STXM) at energies up to 6.2 keV, producing images of test structures that demonstrate a spatial resolution of 25 nm. High spatial resolution STXM images of several biological specimens have been acquired in transmission, dark-field and differential phase contrast modes.

  17. Comparison of GATE/GEANT4 with EGSnrc and MCNP for electron dose calculations at energies between 15 keV and 20 MeV

    NASA Astrophysics Data System (ADS)

    Maigne, L.; Perrot, Y.; Schaart, D. R.; Donnarieix, D.; Breton, V.

    2011-02-01

    The GATE Monte Carlo simulation platform based on the GEANT4 toolkit has come into widespread use for simulating positron emission tomography (PET) and single photon emission computed tomography (SPECT) imaging devices. Here, we explore its use for calculating electron dose distributions in water. Mono-energetic electron dose point kernels and pencil beam kernels in water are calculated for different energies between 15 keV and 20 MeV by means of GATE 6.0, which makes use of the GEANT4 version 9.2 Standard Electromagnetic Physics Package. The results are compared to the well-validated codes EGSnrc and MCNP4C. It is shown that recent improvements made to the GEANT4/GATE software result in significantly better agreement with the other codes. We furthermore illustrate several issues of general interest to GATE and GEANT4 users who wish to perform accurate simulations involving electrons. Provided that the electron step size is sufficiently restricted, GATE 6.0 and EGSnrc dose point kernels are shown to agree to within less than 3% of the maximum dose between 50 keV and 4 MeV, while pencil beam kernels are found to agree to within less than 4% of the maximum dose between 15 keV and 20 MeV.

  18. Comparison of GATE/GEANT4 with EGSnrc and MCNP for electron dose calculations at energies between 15 keV and 20 MeV.

    PubMed

    Maigne, L; Perrot, Y; Schaart, D R; Donnarieix, D; Breton, V

    2011-02-01

    The GATE Monte Carlo simulation platform based on the GEANT4 toolkit has come into widespread use for simulating positron emission tomography (PET) and single photon emission computed tomography (SPECT) imaging devices. Here, we explore its use for calculating electron dose distributions in water. Mono-energetic electron dose point kernels and pencil beam kernels in water are calculated for different energies between 15 keV and 20 MeV by means of GATE 6.0, which makes use of the GEANT4 version 9.2 Standard Electromagnetic Physics Package. The results are compared to the well-validated codes EGSnrc and MCNP4C. It is shown that recent improvements made to the GEANT4/GATE software result in significantly better agreement with the other codes. We furthermore illustrate several issues of general interest to GATE and GEANT4 users who wish to perform accurate simulations involving electrons. Provided that the electron step size is sufficiently restricted, GATE 6.0 and EGSnrc dose point kernels are shown to agree to within less than 3% of the maximum dose between 50 keV and 4 MeV, while pencil beam kernels are found to agree to within less than 4% of the maximum dose between 15 keV and 20 MeV. PMID:21239846

  19. Attenuation coefficients of soils and some building materials of Bangladesh in the energy range 276-1332 keV.

    PubMed

    Alam, M N; Miah, M M; Chowdhury, M I; Kamal, M; Ghose, S; Rahman, R

    2001-06-01

    The linear and mass attenuation coefficients of different types of soil, sand, building materials and heavy beach mineral samples from the Chittagong and Cox's Bazar area of Bangladesh were measured using a high-resolution HPGe detector and the gamma-ray energies 276.1, 302.8, 356.0, 383.8, 661.6 and 1173.2 and 1332.5 keV emitted from point sources of 133Ba, 137Cs and 60Co, respectively. The linear attenuation coefficients show a linear relationship with the corresponding densities of the samples studied. The variations of the mass attenuation coefficient with gamma-ray energy were exponential in nature. The measured mass attenuation coefficient values were compared with measurements made in other countries for similar kinds of materials. The values are in good agreement with each other in most cases. PMID:11300413

  20. Mu-2 ranging

    NASA Technical Reports Server (NTRS)

    Martin, W. L.; Zygielbaum, A. I.

    1977-01-01

    The Mu-II Dual-Channel Sequential Ranging System designed as a model for future Deep Space Network ranging equipment is described. A list of design objectives is followed by a theoretical explanation of the digital demodulation techniques first employed in this machine. Hardware and software implementation are discussed, together with the details relating to the construction of the device. Two appendixes are included relating to the programming and operation of this equipment to yield the maximum scientific data.

  1. The Morphology of the X-ray Emission above 2 keV from Jupiter's Aurorae

    NASA Technical Reports Server (NTRS)

    Elsner, R.; Branduardi-Raymont, G.; Galand, M.; Grodent, D.; Waite, J. H.; Cravens, T.; Ford, P.

    2007-01-01

    The discovery in XMM-Newton X-ray data of X-ray emission above 2 keV from Jupiter's aurorae has led us to reexamine the Chandra ACIS-S observations taken in Feb 2003. Chandra's superior spatial resolution has revealed that the auroral X-rays with E > 2 keV are emitted from the periphery of the region emitting those with E < 1 keV. We are presently exploring the relationship of this morphology to that of the FUV emission from the main auroral oval and the polar cap. The low energy emission has previously been established as due to charge exchange between energetic precipitating ions of oxygen and either sulfur or carbon. It seems likely to us that the higher energy emission is due to precipitation of energetic electrons, possibly the same population of electrons responsible for the FUV emission. We discuss our analysis and interpretation.

  2. Ionization of water by (20-150)-keV protons: Separation of direct-ionization and electron-capture processes

    SciTech Connect

    Gobet, F.; Eden, S.; Coupier, B.; Tabet, J.; Farizon, B.; Farizon, M.; Gaillard, M.J.; Carre, M.; Ouaskit, S.; Maerk, T. D.; Scheier, P.

    2004-12-01

    Mass analyzed product ions have been detected in coincidence with the projectile following the ionization of water by proton impact. Measurement of the projectile charge state postcollision enables the different ionization processes to be identified: direct ionization, single electron capture, and double electron capture. A complete set of partial and total absolute cross sections is reported for the direct ionization and electron capture processes initiated by proton collisions at 20-150 keV. The cross sections for the direct ionization of H{sub 2}O by proton impact are compared with previous electron impact results [Straub et al., J. Chem. Phys. 108, 109 (1998)].

  3. Fracture behavior of a B2 Ni-30Al-20Fe-0.05Zr intermetallic alloy in the temperature range 300 to 1300 K

    NASA Technical Reports Server (NTRS)

    Raj, S. V.

    1992-01-01

    The fracture behavior of a B2 Ni-30Al-20Fe-0.05Zr (at. pct) alloy was investigated using results of tensile tests conducted in the temperature range 300-1300 K under initial strain rates that varied between 10 exp -6 and 10 exp -3/sec, together with results of deformation measurements reported by Raj et al. (1992). Microstructural observations revealed that the alloy had failed by transgranular cleavage fracture below 873 K and by ductile fracture, power-law cavitation, triple point cracking, and rupture above this temperautre. The fracture map constructed using fracture results is compared with those for other classes of materials, showing that the atomic bonding plays a significant role in the low-temperature ductility of NiAl-based alloys.

  4. Inelastic processes in Na+-Ne, Na+-Ar, Ne+-Na, and Ar+-Na collisions in the energy range 0.5-14 keV

    NASA Astrophysics Data System (ADS)

    Lomsadze, R. A.; Gochitashvili, M. R.; Kezerashvili, R. Ya.

    2015-12-01

    Absolute cross sections for charge-exchange, ionization, and excitation in Na+-Ne and Na+-Ar collisions were measured in the ion energy range 0.5 -10 keV using a refined version of a capacitor method and collision and optical spectroscopy methods simultaneously in the same experimental setup. Ionization cross sections for Ne+-Na and Ar+-Na collisions are measured at energies of 2 -14 keV using a crossed-beam spectroscopy method. The experimental data and the schematic correlation diagrams are used to analyze and determine the mechanisms for these processes. For the charge-exchange process in Na+-Ar collisions two nonadiabatic regions are revealed and mechanisms responsible for these regions are explained. Structural peculiarity on the excitation function for the resonance lines of argon atoms in Na+-Ar collisions are observed and the possible mechanisms of this phenomenon are explored. The measured ionization cross sections for Na+-Ne and Ne+-Na collisions in conjunction with the Landau-Zener formula are used to determine the coupling matrix element and transition probability in a region of pseudocrossing of the potential curves.

  5. Fragmentation of H2O by 1 -- 5 keV He^2+ ions: Experiment and Theory

    NASA Astrophysics Data System (ADS)

    Stolterfoht, N.; Hellhammer, R.; Sobocinski, P.; Cabrera-Trujillo, R.; Ohrn, Y.; Deumens, E.; Sabin, J.

    2006-05-01

    Fragmentation of H2O molecules induced by ^3He^2+ impact was investigated experimentally as a function of the energy in the range from 1-5 keV. Collisions at large impact parameters are found to produce fragment protons with energies centered around peaks at 6 eV and 15 eV. The H^+ fragments were detected in the angular range from 25 to 135 with respect to the incident beam direction. Absolute fragmentation cross sections dσ/dφ, differential in the emission angle are found to be anisotropic, with protons preferentially emitted at angles near 90 . In addition to the experiments, we performed quantum-mechanical calculations to understand the fragmentation mechanisms producing protons at preferred energies and angles. The theoretical results are obtained using the Electron-Nuclear Dynamics formalism (END), which solves the time-dependent Schr"odinger equation.

  6. Absolute Calibration of Kodak Biomax-MS Film Response to X Rays in the 1.5- to 8-keV Energy Range

    SciTech Connect

    Marshall, F.J.; Knauer, J.P.; Anderson, D.; Schmitt, B.L.

    2006-09-28

    The absolute response of Kodak Biomax-MS film to x rays in the range from 1.5- to 8-keV has been measured using a laboratory e-beam generated x-ray source. The measurements were taken at specific line energies by using Bragg diffraction to produce monochromatic beams of x rays. Multiple exposures were taken on Biomax MS film up to levels exceeding optical densities of 2 as measured by a microdensitometer. The absolute beam intensity for each exposure was measured with a Si(Li) detector. Additional response measurements were taken with Kodak direct exposure film (DEF) so as to compare the results of this technique to previously published calibrations.

  7. Neutron-induced fission cross section of Np237 in the keV to MeV range at the CERN n_TOF facility

    DOE PAGESBeta

    Diakaki, M.; Karadimos, D.; Vlastou, R.; Kokkoris, M.; Demetriou, P.; Skordis, E.; Tsinganis, A.; Abbondanno, U.; Aerts, G.; Álvarez, H.; et al

    2016-03-17

    We experimentally determined the neutron-induced fission cross section of Np-237 at the high-resolution and high-intensity facility n_TOF, at CERN, in the energy range 100 keV to 9 MeV, using the U-235(n, f) and U-238(n, f) cross section standards below and above 2 MeV, respectively. Moreover, a fast ionization chamber was used in order to detect the fission fragments from the reactions and the targets were characterized as far as their mass and homogeneity are concerned by means of a spectroscopy and Rutherford backscattering spectroscopy respectively. Finally, theoretical calculations within the Hauser-Feshbach formalism have been performed, employing the EMPIRE code, andmore » the model parameters were tuned in order to successfully reproduce the experimental fission cross-sectional data and simultaneously all the competing reaction channels.« less

  8. Neutron-induced fission cross section of 237Np in the keV to MeV range at the CERN n_TOF facility

    NASA Astrophysics Data System (ADS)

    Diakaki, M.; Karadimos, D.; Vlastou, R.; Kokkoris, M.; Demetriou, P.; Skordis, E.; Tsinganis, A.; Abbondanno, U.; Aerts, G.; Álvarez, H.; Alvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Assimakopoulos, P.; Audouin, L.; Badurek, G.; Baumann, P.; Bečvář, F.; Berthoumieux, E.; Calviani, M.; Calviño, F.; Cano-Ott, D.; Capote, R.; Carrillo de Albornoz, A.; Cennini, P.; Chepel, V.; Chiaveri, E.; Colonna, N.; Cortes, G.; Couture, A.; Cox, J.; David, S.; Dolfini, R.; Domingo-Pardo, C.; Dorochenko, A.; Dridi, W.; Duran, I.; Eleftheriadis, Ch.; Embid-Segura, M.; Ferrant, L.; Ferrari, A.; Ferreira-Marques, R.; Fitzpatrick, L.; Frais-Koelbl, H.; Fuji, K.; Furman, W.; Goncalves, I.; Gallino, R.; Gonzalez-Romero, E.; Goverdovski, A.; Gramegna, F.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Haas, B.; Haight, R.; Heil, M.; Herrera-Martinez, A.; Igashira, M.; Ioannidis, K.; Isaev, S.; Jericha, E.; Kadi, Y.; Käppeler, F.; Karamanis, D.; Kerveno, M.; Ketlerov, V.; Koehler, P.; Kolokolov, D.; Konovalov, V.; Krtička, M.; Lamboudis, C.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, S.; Marganiec, J.; Marques, L.; Marrone, S.; Massimi, C.; Mastinu, P.; Mengoni, A.; Milazzo, P. M.; Moreau, C.; Mosconi, M.; Neves, F.; Oberhummer, H.; O'Brien, S.; Oshima, M.; Pancin, J.; Papadopoulos, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perrot, L.; Plag, R.; Plompen, A.; Plukis, A.; Poch, A.; Pretel, C.; Quesada, J.; Rauscher, T.; Reifarth, R.; Rosetti, M.; Rubbia, C.; Rudolf, G.; Rullhusen, P.; Salgado, J.; Sarchiapone, L.; Savvidis, I.; Sedysheva, M.; Stamoulis, K.; Stephan, C.; Tagliente, G.; Tain, J. L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M. C.; Vlachoudis, V.; Voss, F.; Wendler, H.; Wiescher, M.; Wisshak, K.; n TOF Collaboration

    2016-03-01

    The neutron-induced fission cross section of 237Np was experimentally determined at the high-resolution and high-intensity facility n_TOF, at CERN, in the energy range 100 keV to 9 MeV, using the 235U(n ,f ) and 238U(n ,f ) cross section standards below and above 2 MeV, respectively. A fast ionization chamber was used in order to detect the fission fragments from the reactions and the targets were characterized as far as their mass and homogeneity are concerned by means of α spectroscopy and Rutherford backscattering spectroscopy respectively. Theoretical calculations within the Hauser-Feshbach formalism have been performed, employing the empire code, and the model parameters were tuned in order to successfully reproduce the experimental fission cross-sectional data and simultaneously all the competing reaction channels.

  9. Imager of low energy neutral atoms (ILENA) - Imaging neutrals from the magnetosphere at energies below 20 keV

    NASA Technical Reports Server (NTRS)

    Herrero, Federico A.; Smith, Mark F.

    1992-01-01

    We describe a new imager suitable for measurements of magnetospheric neutrals with energies from about 100 eV to about 10 keV; an energy range adequate for imaging the plasmasheet neutral atoms out to about 10 R(E). The instrument, an outgrowth of a study of atom-surface collisions in support of satellite drag calculations, separates incident photons from neutral atoms by surface scattering and conversion of the neutrals to ions. Subsequently, the ions formed on the first surface are accelerated through a light rejection section which also disperses the ions according to energy. The dispersed ion beam is then allowed to impact a second surface where a start pulse is generated to obtain ion velocity and energy/charge. The second surface is chosen to give large secondary electron emission without regard to charge state of the particles reflected from it. The data supporting the proposed ILENA design is presented in the first part of the paper.

  10. Mass attenuation coefficients of Martian meteorites and Earth composition in the energy range 1 keV-100 GeV

    NASA Astrophysics Data System (ADS)

    Ün, M.; Han, E. Narmanli; Ün, A.

    2016-04-01

    Mass attenuation coefficients for 24 Martian meteorites have been determined in the energy range from 1 keV to 100 GeV. The values of mass attenuation coefficients (µ/ρ) of the samples were calculated the WINXCOM program. The obtained results for Martian meteorites have been compared with the results for Earth composition and similarities or differences also evaluated.

  11. The average 0.5-200 keV spectrum of local active galactic nuclei and a new determination of the 2-10 keV luminosity function at z ≈ 0

    NASA Astrophysics Data System (ADS)

    Ballantyne, D. R.

    2014-01-01

    The broad-band X-ray spectra of active galactic nuclei (AGNs) contains information about the nuclear environment from Schwarzschild radii scales (where the primary power law is generated in a corona) to distances of ˜1 pc (where the distant reflector may be located). In addition, the average shape of the X-ray spectrum is an important input into X-ray background synthesis models. Here, local (z ≈ 0) AGN luminosity functions (LFs) in five energy bands are used as a low-resolution, luminosity-dependent X-ray spectrometer in order to constrain the average AGN X-ray spectrum between 0.5 and 200 keV. The 15-55 keV LF measured by Swift-BAT is assumed to be the best determination of the local LF, and then a spectral model is varied to determine the best fit to the 0.5-2 keV, 2-10 keV, 3-20 keV and 14-195 keV LFs. The spectral model consists of a Gaussian distribution of power laws with a mean photon-index <Γ> and cutoff energy Ecut, as well as contributions from distant and disc reflection. The reflection strength is parametrized by varying the Fe abundance relative to solar, AFe, and requiring a specific Fe Kα equivalent width (EW). In this way, the presence of the X-ray Baldwin effect can be tested. The spectral model that best fits the four LFs has <Γ> = 1.85 ± 0.15, E_{cut}=270^{+170}_{-80} keV, A_{Fe}=0.3^{+0.3}_{-0.15}. The sub-solar AFe is unlikely to be a true measure of the gas-phase metallicity, but indicates the presence of strong reflection given the assumed Fe Kα EW. Indeed, parametrizing the reflection strength with the R parameter gives R=1.7^{+1.7}_{-0.85}. There is moderate evidence for no X-ray Baldwin effect. Accretion disc reflection is included in the best-fitting model, but it is relatively weak (broad iron Kα EW < 100 eV) and does not significantly affect any of the conclusions. A critical result of our procedure is that the shape of the local 2-10 keV LF measured by HEAO-1 and MAXI is incompatible with the LFs measured in the hard X

  12. Absolute Doubly Differential Cross Sections for Ejection of Electrons in - and Five-Body Collisions of 20 TO 114-KEV Protons on Atomic and Molecular Hydrogen.

    NASA Astrophysics Data System (ADS)

    Kerby, George W., III

    A crossed-beam experiment was performed to detect ejected electrons from ground-state atomic and molecular hydrogen after collisions with 20- to 114-keV protons. Because a pure atomic hydrogen target is not readily attainable, a method has been devised which yields atomic to molecular hydrogen doubly differential cross section (DDCS) ratios. Since the molecular hydrogen DDCS's were independently measured, the atomic cross sections could be directly calculated. Absolute cross sections differential in electron energy and angle were measured for electron energies ranging from 1.5 to 400 eV and scattering angles from 15^circ to 165^circ with respect to the fast beam. Electrons and ions were energy analyzed by an electrostatic hemispherical analyzer, which has an energy resolution of 5% and is rotatable in the scattering plane about the collision center. Atomic hydrogen is produced by a radio-frequency discharge of the type devised by J. Slevin. Hydrogen gas effuses from a 1 mm diameter nozzle in a nearly cos theta distribution. The projectile beam intersects the thermal gas targets 4 mm below the tip of the nozzle. Dissociation fractions of 74% and atomic hydrogen densities of 7 times 10 ^{11} cm^ {-3} were typical. The fraction of dissociated hydrogen was measured by detecting the reduced 9-eV ion signal from the molecular target when the RF is on. This characteristic ion signal originates from the coulomb breakup of the molecule and dissociative channels of excited H _sp{2}{+}. An auxiliary experiment was performed to determine the target densities with the aid of a low-resolution magnetic mass spectrometer after the slow recoil ions were extracted from the collision volume by a weak electric field. Comparisons of the atomic cross sections are made with theories such as the classical-trajectory Monte Carlo (CTMC) method, the plane-wave Born approximation (PWBA) and the continuum-distorted-wave eikonal-initial-state (CDW-EIS) approximation.

  13. Determination of the effective atomic numbers and electron densities for YBaCuO superconductor in the range 59.5 136 keV

    NASA Astrophysics Data System (ADS)

    Baltaş, H.; Çevik, U.

    2008-04-01

    The effective atomic numbers and electron densities of YBa 2Cu 3O 7-δ superconductor at 59.5, 65.2, 77.1, 94.6, 122 and 136 keV were calculated by using the measured mass attenuation coefficients. Measurements were made by performing transmission experiments in a well-collimated narrow beam geometry set-up by employing Si(Li) detector with a resolution of 0.16 keV at 5.9 keV. These values are found to be in good agreement with theoretical values calculated based on XCOM data. The observed crystal structure of YBa 2Cu 3O 7-δ superconductor is close to the theoretical structure. Zeff and Nel experimental values showed good agreement with the theoretical values for calcined and sintered YBa 2Cu 3O 7-δ.

  14. Absolute detection efficiency of a microchannel plate detector to X rays in the 1-100 KeV energy range

    NASA Astrophysics Data System (ADS)

    Burginyon, Gary A.; Jacoby, Barry A.; Wobser, James K.; Ernst, Richard; Ancheta, Dione S.; Tirsell, Kenneth G.

    1993-02-01

    There is little information in the literature on the performance of working micro-channel plate (MCP) detectors at high x-ray energies. We have measured the absolute efficiency of a microchannel-plate-intensified, subnanosecond, one dimensional imaging x-ray detector developed at LLNL in the 1 to 100 keV range and at 1.25 MeV. The detector consists of a gold photocathode deposited on the front surface of the MCP (optimized for Ni K(subscript (alpha) ) x rays) to convert x rays to electrons, an MCP to amplify the electrons, and a fast In:CdS phosphor that converts the electron's kinetic energy to light. The phosphor is coated on a fiber-optic faceplate to transmit the light out of the vacuum system. Electrostatic focusing electrodes compress the electron current out of the MCP in one dimension while preserving spatial resolution in the other. The calibration geometry, dictated by a recent experiment, required grazing incidence x rays (15.6 degree(s)) onto the MCP detector in order to maximize deliverable current. The experiment also used a second detector made up of 0.071 in. thick BC422 plastic scintillator material from the Bicron Corporation. We compare the absolute efficiencies of these two detectors in units of optical W/cm(superscript 2) into 4 (pi) per x ray W/cm(superscript 2) incident. At 7.47 keV and 900 volts MCP bias, the MCP detector delivers approximately 1400 times more light than the scintillator detector.

  15. Investigation on ultracold RbCs molecules in (2)0(+) long-range state below the Rb(5S1/2) + Cs(6P1/2) asymptote by high resolution photoassociation spectroscopy.

    PubMed

    Yuan, Jinpeng; Ji, Zhonghua; Li, Zhonghao; Zhao, Yanting; Xiao, Liantuan; Jia, Suotang

    2015-07-28

    We present high resolution photoassociation spectroscopy of RbCs molecules in (2)0(+) long-range state below the Rb(5S1/2) + Cs(6P1/2) asymptote and derive the corresponding C6 coefficient, which is used to revise the potential energy curves. The excited state molecules are produced in a dual-species dark spontaneous force optical trap and detected by ionizing ground state molecules after spontaneous decay, using a high sensitive time-of-flight mass spectrum. With the help of resonance-enhanced two-photon ionization technique, we obtain considerable high resolution photoassociation spectrum with rovibrational states, some of which have never been observed before. By applying the LeRoy-Bernstein method, we assign the vibrational quantum numbers and deduce C6 coefficient, which agrees with the theoretical value of A(1)Σ(+) state correlated to Rb(5S1/2) + Cs(6P1/2) asymptote. The obtained C6 coefficient is used to revise the long-range potential energy curve for (2)0(+) state, which possesses unique A - b mixing characteristic and can be a good candidate for the production of absolutely ground state molecule. PMID:26233133

  16. Investigation on ultracold RbCs molecules in (2)0+ long-range state below the Rb(5S1/2) + Cs(6P1/2) asymptote by high resolution photoassociation spectroscopy

    NASA Astrophysics Data System (ADS)

    Yuan, Jinpeng; Ji, Zhonghua; Li, Zhonghao; Zhao, Yanting; Xiao, Liantuan; Jia, Suotang

    2015-07-01

    We present high resolution photoassociation spectroscopy of RbCs molecules in (2)0+ long-range state below the Rb(5S1/2) + Cs(6P1/2) asymptote and derive the corresponding C6 coefficient, which is used to revise the potential energy curves. The excited state molecules are produced in a dual-species dark spontaneous force optical trap and detected by ionizing ground state molecules after spontaneous decay, using a high sensitive time-of-flight mass spectrum. With the help of resonance-enhanced two-photon ionization technique, we obtain considerable high resolution photoassociation spectrum with rovibrational states, some of which have never been observed before. By applying the LeRoy-Bernstein method, we assign the vibrational quantum numbers and deduce C6 coefficient, which agrees with the theoretical value of A1Σ+ state correlated to Rb(5S1/2) + Cs(6P1/2) asymptote. The obtained C6 coefficient is used to revise the long-range potential energy curve for (2)0+ state, which possesses unique A - b mixing characteristic and can be a good candidate for the production of absolutely ground state molecule.

  17. Investigation on ultracold RbCs molecules in (2)0{sup +} long-range state below the Rb(5S{sub 1/2}) + Cs(6P{sub 1/2}) asymptote by high resolution photoassociation spectroscopy

    SciTech Connect

    Yuan, Jinpeng; Ji, Zhonghua; Li, Zhonghao; Zhao, Yanting Xiao, Liantuan; Jia, Suotang

    2015-07-28

    We present high resolution photoassociation spectroscopy of RbCs molecules in (2)0{sup +} long-range state below the Rb(5S{sub 1/2}) + Cs(6P{sub 1/2}) asymptote and derive the corresponding C{sub 6} coefficient, which is used to revise the potential energy curves. The excited state molecules are produced in a dual-species dark spontaneous force optical trap and detected by ionizing ground state molecules after spontaneous decay, using a high sensitive time-of-flight mass spectrum. With the help of resonance-enhanced two-photon ionization technique, we obtain considerable high resolution photoassociation spectrum with rovibrational states, some of which have never been observed before. By applying the LeRoy-Bernstein method, we assign the vibrational quantum numbers and deduce C{sub 6} coefficient, which agrees with the theoretical value of A{sup 1}Σ{sup +} state correlated to Rb(5S{sub 1/2}) + Cs(6P{sub 1/2}) asymptote. The obtained C{sub 6} coefficient is used to revise the long-range potential energy curve for (2)0{sup +} state, which possesses unique A − b mixing characteristic and can be a good candidate for the production of absolutely ground state molecule.

  18. The Morphology of the X-ray Emission above 2 keV from Jupiter's Aurorae

    NASA Technical Reports Server (NTRS)

    Elsner, R.; Branduardi-Raymont, G.; Galand, M.; Grodent, D.; Gladstone, G. R.; Waite, J. H.; Cravens, T.; Ford, P.

    2007-01-01

    The discovery in XMM-Newton X-ray data of X-ray emission above 2 keY from Jupiter's aurorae has led us to reexamine the Chandra ACIS-S observations taken in Feb 2003. Chandra's superior spatial resolution has revealed that the auroral X-rays with E > 2 keV are emitted from the periphery of the region emitting those with E < 1 keV. We are presently exploring the relationship of this morphology to that of the FUV emission from the main auroral oval and the polar cap. The low energy emission has previously been established as due to charge exchange between energetic precipitating ions of oxygen and either sulfur or carbon. It seems likely to us that the higher energy emission is due to precipitation of energetic electrons, possibly the same population of electrons responsible for the FUV emission. We discuss our analysis and interpretation.

  19. Measurement of the x-ray mass attenuation coefficient of copper using 8.85-20 keV synchrotron radiation

    NASA Astrophysics Data System (ADS)

    Chantler, C. T.; Tran, C. Q.; Barnea, Z.; Paterson, D.; Cookson, D. J.; Balaic, D. X.

    2001-12-01

    This work presents the x-ray extended range technique for measuring x-ray mass attenuation coefficients. This technique includes the use of multiple foil attenuators at each energy investigated, allowing independent tests of detector linearity and of the harmonic contributions to the monochromated synchrotron beam. Measurements over a wide energy range allow the uncertainty of local foil thickness to be minimized by the calibration of thin sample measurements to those of thick samples. The use of an extended criterion for sample thickness selection allows direct determination of dominant systematics, with an improvement of accuracies compared to previous measurements by up to factors of 20. Resulting accuracies for attenuation coefficients of copper (8.84 to 20 keV) are 0.27-0.5 %, with reproducibility of 0.02%. We also extract the imaginary component of the form factor from the data with the same accuracy. Results are compared to theoretical calculations near and away from the absorption edge. The accuracy challenges available theoretical calculations, and observed discrepancies of 10% between current theory and experiments can now be addressed.

  20. Polarization evidence for the isotropy of electrons responsible for the production of 5-20 keV X-rays in solar flares

    NASA Astrophysics Data System (ADS)

    Tramiel, L. J.; Novick, R.; Chanan, G. A.

    1984-05-01

    We have flown a solar flare X-ray polarimeter on the third flight (STS 3) of the Space Shuttle Columbia as part of the OSS-1 pallet of instruments. We observed eight solar flares in the 5-20 keV band on 1982 March 28. The signal-to-background ratio in all cases exceeded 25. A preflight contamination problem invalidated the earlier laboratory calibration, and the instrument had to be calibrated in-flight against two flares near the center of the solar disk, which are expected to be unpolarized on geometric grounds in a variety of models. No statistically significant polarization was then detected in any of the other six flares. Upper limits (99% confidence level) range from 2.5% to 12.7%. For two of the observed flares these results disagree with the predictions of a simple radially beamed, linear bremsstrahlung model at greater than 99% confidence. One of these flares had a hard impulsive burst; the measured upper limit on this burst (10%) also disagrees with the predictions of the beamed hypothesis. If the calibration flares were polarized, then the above upper limits can be interpreted as limits on the changes in polarization from flare to flare. Because the observed flares spanned a large longitude range and because the predictions of the beamed models depend fairly sensitively on viewing angle, the small relative polarizations are still difficult to reconcile with simple beamed models. The results are also compared with recent, more sophisticated models of Leach and Petrosian, which generally predict lower polarizations. We find that the observations are marginally inconsistent with a model in which the electrons are initially strongly beamed, but subsequently become largely isotropic as a result of the effects of a converging magnetic field; they are consistent with a model in which the electrons are injected isotropically, but in which the preference for motion along the magnetic field lines is explicitly taken into account. The results are also consistent

  1. Detection of interplanetary electrons from 18 keV to 1.8 MeV during solar quiet times, 1. On the origin of 200 KeV interplanetary electrons, 2.

    NASA Technical Reports Server (NTRS)

    Lin, R. P.; Anderson, K. A.; Cline, T. L.; Ramaty, R.; Fisk, L. A.

    1972-01-01

    A quiet time component of interplanetary electrons having energies above solar wind energies and below those characterized as cosmic radiation was observed. Its energy spectrum falls with energy from 18 keV to 1.8 MeV, but it shows a feature in the 100 to 300 keV range. The observed temporal variations of the intensity suggest that the 18 to 100 keV portion is solar and the 0.3 to 1.8 MeV portion is galactic in origin. Solar and terrestrial neutron decay electrons appear inadequate to explain the 100 to 300 keV feature.

  2. Differential cross sections for scattering of 0.5-, 1.5-, and 5.0 keV oxygen atoms by He, N2, and O2

    NASA Technical Reports Server (NTRS)

    Schafer, D. A.; Newman, J. H.; Smith, K. A.; Stebbings, R. F.

    1987-01-01

    This paper reports measurements of absolute scattering cross sections, differential in angle, for collisions of ground-state oxygen atoms with He, N2, and O2. Data are presented for scattering of 0.5-, 1.5-, and 5.0-keV oxygen-atom projectiles in the range of laboratory frame angles between 0.06 and 5 deg. These measurements provide information relevant to calculations of the aeronomic consequences of O(+) precipitation in the earth's upper atmosphere.

  3. A large scale height galactic component of the diffuse 2-60 keV background

    NASA Technical Reports Server (NTRS)

    Iwan, D.; Marshall, F. E.; Boldt, E. A.; Mushotzky, R.; Shafer, R. A.; Stottlemyer, A.

    1982-01-01

    The diffuse 2-60 keV X-ray background has a galactic component clearly detectable by its strong variation with both galactic latitude and longitude. This galactic component is typically 10 percent of the extragalactic background toward the galactic center, half that strong toward the anticenter, and extrapolated to a few percent of the extragalactic background toward the galactic poles. It is acceptably modeled by a finite radius emission disk with a scale height of several kiloparsecs. The averaged galactic spectrum is best fitted by a thermal spectrum of kT about 9 keV, a spectrum much softer than the about 40 keV spectrum of the extragalactic component. The most likely source of this emission is low luminosity stars with large scale heights such as subdwarfs. Inverse Compton emission from GeV electrons on the microwave background contributes only a fraction of the galactic component unless the local cosmic ray electron spectrum and intensity are atypical.

  4. Comparison of Martian meteorites with earth composition: Study of effective atomic numbers in the energy range 1 keV-100 GeV

    NASA Astrophysics Data System (ADS)

    Ün, Adem; Han, Ibrahim; Ün, Mümine

    2016-04-01

    Effective atomic (Zeff) and electron numbers (Neff) for 24 Martian meteorites have been determined in the energy range from 1 keV to 100 GeV and also for sixteen significant energies of commonly used radioactive sources. The values of Zeff and Neff for all sample were obtained from the DirectZeff program. The obtained results for Martian meteorites have been compared with the results for Earth composition and similarities or differences also evaluated.

  5. Ionic Liquids as a Reference Material Candidate for the Quick Performance Check of Energy Dispersive X-ray Spectrometers for the Low Energy Range below 1 keV

    PubMed Central

    2016-01-01

    Ionic liquids (ILs) are proposed as simple and efficient test materials to evaluate the performance of energy dispersive X-ray spectrometers (EDS) in the low energy range below 1 keV. By only one measurement, C Kα, N Kα, O Kα, and F Kα X-ray lines can be excited. Additionally, the S Kα line at 2.3 keV and, particularly, the S L series at 149 eV complete the picture with X-ray lines offered by the selected ILs. The well-known (certifiable) elemental composition of the ILs selected in the present study can be used to check the accuracy of results produced with the available EDS quantification routines in the low energy range, simultaneously, for several low atomic number elements. A comparison with other reference materials in use for testing the performance of EDS in the low energy range is included. PMID:27336962

  6. Angular differential cross sections for excitation of atomic hydrogen to its N = 2 level by impact of 15-100 keV He/sup +/ ions

    SciTech Connect

    Aldag, J.E.

    1980-01-01

    Differential cross section for excitation of atomic hydrogen to its n = 2 level by 15-100 keV He/sup +/ ions have been determned for c.m. angles from 0 to 8 mrad. The cross sections were obtained from an analysis of the angular distribution of the scattered ions which had lost an energy corresponding to the excitation of the target to its n = 2 level. The shape of the differential cross section changes rapidly with increasing incident energy. At 15 keV, the cross section changes rapidly with increasing incident energy. At 15 keV, the cross section falls off by a factor of 5 in 6 mrad. At 100 keV, the cross section decreases by nearly six orders or magnitude in the same angular range. The middle and high energy results are in good agreement with a recent Glauber approximation calculation for the scattering. Comparison of the present reduced cross section results with those at lower energy (0.75 to 1.5 keV) indicates that the collision mechanism is not the same. Excitation to n greater than or equal to 3 levels was clearly present in the energy-loss spectra for the process in contradiction to the molecular orbital description of the mechanism. Total cross section results are given for the same scattering process in the 15-200 keV range and are also in good agreement with the Glauber and VPSA theory results. The experimental and Glauber differential results, however, are clearly different at 25 keV.

  7. On the vectorial photoelectric effect at 2.69 keV

    NASA Technical Reports Server (NTRS)

    Shaw, P. S.; Hanany, S.; Liu, Y.; Church, E. D.; Fleischman, J.; Kaaret, P.; Novick, R.; Santangelo, A.

    1991-01-01

    Recent experiments conducted to study the vectorial photoelectric effect with CsI, Al2O3 and Si photocathodes at 2.69 keV indicate null results. Detailed analysis shows that previously measured modulation can be well explained by geometrical misalignment and a combination of the asymmetric shape of the incident X-ray beam and a small detection area of the photoelectron detector. After the elimination of the sources of spurious modulation, we observed a modulation factor of less than 3 percent for a grazing incidence angle as small as 5 deg. There is no observable difference in the pulse height distribution between s and p states.

  8. 5-20 keV laser-induced x-ray generation at 1 kHz from a liquid-jet target

    NASA Astrophysics Data System (ADS)

    Tompkins, R. J.; Mercer, I. P.; Fettweis, M.; Barnett, C. J.; Klug, D. R.; Porter, Lord G.; Clark, I.; Jackson, S.; Matousek, P.; Parker, A. W.; Towrie, M.

    1998-09-01

    We report ultrashort pulse, 1 kHz repetition rate x-ray generation in the 5-20 keV spectral region, induced by the interaction of laser radiation with copper nitrate solution and ethylene glycol liquid-jet targets. The characteristics of the copper nitrate source are relevant for application to time-resolved x-ray diffraction studies as well as for spectroscopic x-ray absorption studies. The x-ray sources were operated uninterrupted for in excess of 5 h with no detectable buildup of debris on the associated optics. The x-ray flux generated by both sources is estimated to be of the order of 106photons s-1 sr-1 in the 5-20 keV region. The spectra have been measured with both a PIN photodiode, and with transmission measurements taken using aluminum filters. We find that the plasma emission has a broadband component attributed to bremsstrahlung emission, with the bulk of the x-ray emission emitted from the chamber lying between 5 and 20 keV for both sources. The copper nitrate emission, however, delivers a dominant emission peak at 9 keV, attributed to the characteristic K emission of copper.

  9. Model study of the mid-latitude atmospheric interaction with energetic O/sup +/ and He/sup +/ (< 20 keV) precipitation during a storm

    SciTech Connect

    Ishimoto, M.

    1986-01-01

    The purpose of this study is to use a model computation to investigate the mid-latitude atmospheric interaction with energetic O/sup +/ and He/sup +/ (<20 keV) precipitation during a storm. The steady-state continuity equations for the fluxes are formulated as a system of first-order ordinary differential equations. The model, consisting of three components, O, N/sub 2/ and He, computes the upward and downward fluxes resulting from energetic ion precipitation by solving sets of this system of equations. The model computes the heating, the ion production, the N/sub 2//sup +/ first negative (O-O) band and N/sub 2/ second-positive (O-O) band emission intensities in the atmosphere, and the escape fluxes to the magnetosphere. Energetic O/sup +/ deposit 80% of their energy for heating and a few percent for ionization below 200 km, and bring 20% of their incident energy back to the magnetosphere together with 30 O and 5 N/sub 2/ particles from the ionospheres for each incident O/sup +/. Energetic He/sup +/ dissipate by ionization (50%) instead of atmospheric heating (10%). He/sup +/ are reflected at an altitude of about 200 km back to the magnetosphere without losing much energy. He/sup +/ precipitation does not bring the ionospheric neutrals back to the magnetosphere.

  10. Marketing 2.0

    ERIC Educational Resources Information Center

    Germain, Carol Anne

    2008-01-01

    There is no doubt that today's student is much more savvy with using computers than the students of years gone by. This tech generation eagerly embraces the Internet, online searching, and the newer Web 2.0 technologies. This latter platform provides users with the ability to interact in a large virtual world, share/take (upload/download)…

  11. Albany 2.0

    Energy Science and Technology Software Center (ESTSC)

    2012-10-29

    New to version 2.0 of Albany is the development of equations sets for specific application areas. These are independent research and development efforts that have chosen to use Albany as their software deployment vehicle. Because of synergies between the projects, they remain in the same code repository and are all releasing together as the Albany software.

  12. Energy response of GR-200A thermoluminescence dosemeters to 60Co and to monoenergetic synchrotron radiation in the energy range 28-40 keV.

    PubMed

    Emiro, F; Di Lillo, F; Mettivier, G; Fedon, C; Longo, R; Tromba, G; Russo, P

    2016-01-01

    The response of LiF:Mg,Cu,P thermoluminescence dosemeters (type GR-200A) to monoenergetic radiation of energy 28, 35, 38 and 40 keV was evaluated with respect to irradiation with a calibrated (60)Co gamma-ray source. High-precision measurements of the relative air kerma response performed at the SYRMEP beamline of the ELETTRA synchrotron radiation facility (Trieste, Italy) showed a significant deviation of the average response to low-energy X-rays from that to (60)Co, with an over-response from 6 % (at 28 keV) to 22 % (at 40 keV). These data are not consistent with literature data for these dosemeters, where model predictions gave deviation from unity of the relative air kerma response of about 10 %. The authors conclude for the need of additional determinations of the low-energy relative response of GR-200A dosemeters, covering a wider range of monoenergetic energies sampled at a fine energy step, as planned in future experiments by their group at the ELETTRA facility. PMID:25737582

  13. 6 x 6-cm fully depleted pn-junction CCD for high-resolution spectroscopy in the 0.1- to 15-keV photon energy range

    NASA Astrophysics Data System (ADS)

    von Zanthier, Christoph; Holl, Peter; Kemmer, Josef; Lechner, Peter; Maier, B.; Soltau, Heike; Stoetter, R.; Braeuninger, Heinrich W.; Dennerl, Konrad; Haberl, Frank; Hartmann, R.; Hartner, Gisela D.; Hippmann, H.; Kastelic, E.; Kink, W.; Krause, N.; Meidinger, Norbert; Metzner, G.; Pfeffermann, Elmar; Popp, M.; Reppin, Claus; Stoetter, Diana; Strueder, Lothar; Truemper, Joachim; Weber, U.; Carathanassis, D.; Engelhard, S.; Gebhart, Th.; Hauff, D.; Lutz, G.; Richter, R. H.; Seitz, H.; Solc, P.; Bihler, Edgar; Boettcher, H.; Kendziorra, Eckhard; Kraemer, J.; Pflueger, Bernhard; Staubert, Ruediger

    1998-04-01

    The concept and performance of the fully depleted pn- junction CCD system, developed for the European XMM- and the German ABRIXAS-satellite missions for soft x-ray imaging and spectroscopy in the 0.1 keV to 15 keV photon range, is presented. The 58 mm X 60 mm large pn-CCD array uses pn- junctions for registers and for the backside instead of MOS registers. This concept naturally allows to fully deplete the detector volume to make it an efficient detector to photons with energies up to 15 keV. For high detection efficiency in the soft x-ray region down to 100 eV, an ultrathin pn-CCD backside deadlayer has been realized. Each pn-CCD-channel is equipped with an on-chip JFET amplifier which, in combination with the CAMEX-amplifier and multiplexing chip, facilitates parallel readout with a pixel read rate of 3 MHz and an electronic noise floor of ENC < e-. With the complete parallel readout, very fast pn-CCD readout modi can be implemented in the system which allow for high resolution photon spectroscopy of even the brightest x-ray sources in the sky.

  14. Subarcsecond x-ray telescope for imaging the solar corona in the 0.25- to 1.2-keV band

    NASA Astrophysics Data System (ADS)

    Gallagher, Dennis J.; Cash, Webster C.; Jelsma, Schuyler; Farmer, Jason

    1996-07-01

    We have developed an x-ray telescope that uses a new technique for focusing x-rays with grazing incidence optics. The telescope was built with spherical optics for all of its components, utilizing the high quality surfaces obtainable when polishing spherical (as opposed to aspherical) optics. We tested the prototype x-ray telescope in the 300 meter vacuum pipe at White Sands Missile Range, NM. The telescope features 2 degree graze angles with tungsten coatings, yielding a bandpass of 0.25-1.5 keV with a peak effective area of 0.8 cm(superscript 2) at 0.83 keV. Results from x-ray testing at energies of 0.25 keV and 0.93 keV (C-K and Cu-L) verify 0.5 arcsecond performance at 0.93 keV. Results from modeling the x-ray telescope's response to the SUn show that the current design would be capable of recording 10 half arcsecond images of a solar active region during a 300 second NASA sounding rocket flight.

  15. Effect of pd and dd reactions enhancement in deuterides TiD2, ZrD2 and Ta2D in the astrophysical energy range

    NASA Astrophysics Data System (ADS)

    Bystritskii, V. M.; Dudkin, G. N.; Filipowicz, M.; Huran, J.; Krylov, A. R.; Nechayev, B. A.; Padalko, V. N.; Pen'kov, F. M.; Philippov, A. V.; Tuleushev, Yu. Zh.

    2016-01-01

    Investigation of the pd-and dd-reactions in the ultralow energy (~keV) range is of great interest in the aspect of nuclear physics and astrophysics for developing of correct models of burning and evolution of stars. This report presents compendium of experimental results obtained at the pulsed plasma Hall accelerator (TPU, Tomsk). Most of those results are new, such as • temperature dependence of the neutron yield in the D( d, n)3He reaction in the ZrD2, Ta2D, TiD2 • potentials of electron screening and respective dependence of astrophysical S-factors in the dd-reaction for the deuteron collision energy in the range of 3-6 keV, with ZrD2, Ta2D temperature in the range of 20-200°C [1] • characteristics of the reaction d( p, γ)3He in the ultralow collision proton-deuterons energy range of 4-13 keV [2, 3] in ZrD2, Ta2D and TiD2 • observation of the neutron yield enhancement in the reaction D( d, n)3He at the ultralow deuteron collision energy due to channeling of deuterons in microscopic TiD2 with a face-centered cubic lattice type TiD1.73, oriented in the [100] direction [4]. The report includes discussion and comparison of the collected experimental results with the global data and calculations.

  16. Atomic, Molecular, and Optical Physics: Optical Excitation Function of H(1s-2p) Produced by electron Impact from Threshold to 1.8 keV

    NASA Technical Reports Server (NTRS)

    James, G. K.; Slevin, J. A.; Shemansky, D. E.; McConkey, J. W.; Bray, I.; Dziczek, D.; Kanik, I.; Ajello, J. M.

    1997-01-01

    The optical excitation function of prompt Lyman-Alpha radiation, produced by electron impact on atomic hydrogen, has been measured over the extended energy range from threshold to 1.8 keV. Measurements were obtained in a crossed-beams experiment using both magnetically confined and electrostatically focused electrons in collision with atomic hydrogen produced by an intense discharge source. A vacuum-ultraviolet mono- chromator system was used to measure the emitted Lyman-Alpha radiation. The absolute H(1s-2p) electron impact excitation cross section was obtained from the experimental optical excitation function by normalizing to the accepted optical oscillator strength, with corrections for polarization and cascade. Statistical and known systematic uncertainties in our data range from +/- 4% near threshold to +/- 2% at 1.8 keV. Multistate coupling affecting the shape of the excitation function up to 1 keV impact energy is apparent in both the present experimental data and present theoretical results obtained with convergent close- coupling (CCC) theory. This shape function effect leads to an uncertainty in absolute cross sections at the 10% level in the analysis of the experimental data. The derived optimized absolute cross sections are within 7% of the CCC calculations over the 14 eV-1.8 keV range. The present CCC calculations converge on the Bethe- Fano profile for H(1s-2p) excitation at high energy. For this reason agreement with the CCC values to within 3% is achieved in a nonoptimal normalization of the experimental data to the Bethe-Fano profile. The fundamental H(1s-2p) electron impact cross section is thereby determined to an unprecedented accuracy over the 14 eV - 1.8 keV energy range.

  17. Sub-arcsec X-Ray Telescope for Imaging The Solar Corona In the 0.25 - 1.2 keV Band

    NASA Technical Reports Server (NTRS)

    Gallagher, Dennis; Cash, Webster; Jelsma, Schuyler; Farmer, Jason

    1996-01-01

    We have developed an X-ray telescope that uses a new technique for focusing X-rays with grazing incidence optics. The telescope was built with spherical optics for all of its components, utilizing the high quality surfaces obtainable when polishing spherical (as opposed to aspherical) optics. We tested the prototype X-ray telescope in the 300 meter vacuum pipe at White Sands Missile Range, NM. The telescope features 2 degee graze angles with tungsten coatings, yielding a bandpass of 0.25-1.5 keV with a peak effective area of 0.8 sq cm at 0.83 keV. Results from X-ray testing at energies of 0.25 keV and 0.93 keV (C-K and Cu-L) verify 0.5 arcsecond performance at 0.93 keV. Results from modeling the X-ray telescope's response to the Sun show that the current design would be capable of recording 10 half arcsecond images of a solar active region during a 300 second NASA sounding rocket flight.

  18. Electron stopping power and inelastic mean free path in amino acids and protein over the energy range of 20-20,000 eV.

    PubMed

    Tan, Zhenyu; Xia, Yueyuan; Zhao, Mingwen; Liu, Xiangdong

    2006-07-01

    Systematic calculations of stopping power (SPs) and inelastic mean free path (IMFP) values for 20-20,000 eV electrons in a group of 15 amino acids and a simple protein have been performed. The calculations are based on the dielectric response model and take into account the exchange effect between the incident electron and target electrons. The optical energy-loss functions for the 15 investigated amino acids and the protein are evaluated by using an empirical approach, because of the lack of experimental optical data. For all the considered materials, the calculated mean ionization potentials are in good agreement with those given by Bragg's rule, and the evaluated SP values at 20 keV converge well to the Bethe-Bloch predictions. The data shown represent the first results of SP and IMFP, for these 15 amino acids and the protein in the energy range below 20 keV, and might be useful for studies of various radiation effects in these materials. In addition, the average energy deposited by inelastic scattering of the electrons on this group of 15 amino acids, on the protein, on Formvar and on DNA, respectively, has been estimated for energies below 20 keV. The dependences of the average energy deposition on the electron energy are given. These results are important for any detailed studies of radiation-induced inactivation of proteins and the DNA. PMID:16733724

  19. A novel flat-response x-ray detector in the photon energy range of 0.1-4 keV

    NASA Astrophysics Data System (ADS)

    Li, Zhichao; Jiang, Xiaohua; Liu, Shenye; Huang, Tianxuan; Zheng, Jian; Yang, Jiamin; Li, Sanwei; Guo, Liang; Zhao, Xuefeng; Du, Huabin; Song, Tianming; Yi, Rongqing; Liu, Yonggang; Jiang, Shaoen; Ding, Yongkun

    2010-07-01

    A novel flat-response x-ray detector has been developed for the measurement of radiation flux from a hohlraum. In order to obtain a flat response in the photon energy range of 0.1-4 keV, it is found that both the cathode and the filter of the detector can be made of gold. A further improvement on the compound filter can then largely relax the requirement of the calibration x-ray beam. The calibration of the detector, which is carried out on Beijing Synchrotron Radiation Facility at Institute of High Energy Physics, shows that the detector has a desired flat response in the photon energy range of 0.1-4 keV, with a response flatness smaller than 13%. The detector has been successfully applied in the hohlraum experiment on Shenguang-III prototype laser facility. The radiation temperatures inferred from the detector agree well with those from the diagnostic instrument Dante installed at the same azimuth angle from the hohlraum axis, demonstrating the feasibility of the detector.

  20. Absolute calibration of a photodiode array with the use of the synchrotron radiation in the range of 1-10 keV

    NASA Astrophysics Data System (ADS)

    Beck, L.; Bizeuil, C.; Soullie, G.

    1995-02-01

    The silicon photodiode array Hamamatsu S3901 series (1024, 25 μm pixel) were primarily developed for the visible-UV spectral range, mainly for photon wavelengths between 200 and 1100 nm. By utilizing it without a quartz window, it is demonstrated that this sensor can be used for x rays, especially in the 1-10 keV range. Experimental measurements of the absolute detection efficiency of the photodiode array between 1.5 and 12 keV are presented. The experiments were performed on an x-ray tube-excited secondary targets and on the SB3 beamline at the Super ACO storage ring (LURE-Orsay). The measured spectral efficiency is compared with the results of a simple model calculation based on the data given in the Hamamatsu note. The simulation is in good agreement with the experimental data for a silicon active depth of 6 μm and a silicon dioxide passivation layer of 5 μm. The linearity is better than 1% and the spatial resolution is estimated to be 120 μm.

  1. A novel flat-response x-ray detector in the photon energy range of 0.1-4 keV.

    PubMed

    Li, Zhichao; Jiang, Xiaohua; Liu, Shenye; Huang, Tianxuan; Zheng, Jian; Yang, Jiamin; Li, Sanwei; Guo, Liang; Zhao, Xuefeng; Du, Huabin; Song, Tianming; Yi, Rongqing; Liu, Yonggang; Jiang, Shaoen; Ding, Yongkun

    2010-07-01

    A novel flat-response x-ray detector has been developed for the measurement of radiation flux from a hohlraum. In order to obtain a flat response in the photon energy range of 0.1-4 keV, it is found that both the cathode and the filter of the detector can be made of gold. A further improvement on the compound filter can then largely relax the requirement of the calibration x-ray beam. The calibration of the detector, which is carried out on Beijing Synchrotron Radiation Facility at Institute of High Energy Physics, shows that the detector has a desired flat response in the photon energy range of 0.1-4 keV, with a response flatness smaller than 13%. The detector has been successfully applied in the hohlraum experiment on Shenguang-III prototype laser facility. The radiation temperatures inferred from the detector agree well with those from the diagnostic instrument Dante installed at the same azimuth angle from the hohlraum axis, demonstrating the feasibility of the detector. PMID:20687719

  2. A novel flat-response x-ray detector in the photon energy range of 0.1-4 keV

    SciTech Connect

    Li Zhichao; Guo Liang; Jiang Xiaohua; Liu Shenye; Huang Tianxuan; Yang Jiamin; Li Sanwei; Zhao Xuefeng; Du Huabin; Song Tianming; Yi Rongqing; Liu Yonggang; Jiang Shaoen; Ding Yongkun; Zheng Jian

    2010-07-15

    A novel flat-response x-ray detector has been developed for the measurement of radiation flux from a hohlraum. In order to obtain a flat response in the photon energy range of 0.1-4 keV, it is found that both the cathode and the filter of the detector can be made of gold. A further improvement on the compound filter can then largely relax the requirement of the calibration x-ray beam. The calibration of the detector, which is carried out on Beijing Synchrotron Radiation Facility at Institute of High Energy Physics, shows that the detector has a desired flat response in the photon energy range of 0.1-4 keV, with a response flatness smaller than 13%. The detector has been successfully applied in the hohlraum experiment on Shenguang-III prototype laser facility. The radiation temperatures inferred from the detector agree well with those from the diagnostic instrument Dante installed at the same azimuth angle from the hohlraum axis, demonstrating the feasibility of the detector.

  3. A Deep 0.3-10 keV Spectrum of the H2O Maser Galaxy IC 2560

    NASA Astrophysics Data System (ADS)

    Tilak, Avanti; Greenhill, Lincoln J.; Done, Chris; Madejski, Grzegorz

    2008-05-01

    We present a new XMM-Newton spectrum of the Seyfert 2 nucleus of IC 2560, which hosts H2O maser emission from an inclined Keplerian accretion disk. The X-ray spectrum shows soft excess due to multitemperature ionized plasma, a hard continuum, and strong emission features, from Mg, Si, S, Ca, Fe, and Ni, mainly due to fluorescence. It is consistent with reflection of the continuum from a mostly neutral medium and obscuration due to a high column density, >1024 cm-2. The amplitude of the reflected component may exceed 10% of the central unobscured luminosity. This is higher than the reflected fraction of a few percent observed in other Seyfert 2 sources such as NGC 4945. We observe an emission line at 6.7 keV, possibly due to Fe XXV, undetected in previous Chandra observations. The absorption column density associated with this line is less than 1023 cm-2, which is lower than the obscuration of the central source. We hypothesize that this highly ionized Fe line emission originates in warm gas, which is also responsible for a scattered component of continuum emission that may dominate the spectrum between 1 and 3 keV. We compare X-ray and maser emission characteristics of IC 2560 and other AGNs that exhibit water maser emission originating in disk structures around central engines. The temperature for the region of the disk associated with maser action is consistent with the expected 400-1000 K range. The clumpiness of disk structures (inferred from the maser distribution) may depend on the unobscured luminosities of the central engines.

  4. Measurement of the x-ray mass attenuation coefficients of gold in the 38-50-keV energy range

    SciTech Connect

    Islam, M T; Rae, N A; Glover, J L; Barnea, Z; de Jonge, M D; Tran, C Q; Wang, J; Chantler, C T

    2010-11-12

    We used synchrotron x rays to measure the x-ray mass attenuation coefficients of gold at nine energies from 38 to 50 keV with accuracies of 0.1%. Our results are much more accurate than previous measurements in this energy range. A comparison of our measurements with calculated mass attenuation coefficients shows that our measurements fall almost exactly midway between the XCOM and FFAST calculated theoretical values, which differ from one another in this energy region by about 4%, even though the range includes no absorption edge. The consistency and accuracy of these measurements open the way to investigations of the x-ray attenuation in the region of the L absorption edge of gold.

  5. Web 2.0, Meet Literacy 2.0

    ERIC Educational Resources Information Center

    Penrod, Diane

    2008-01-01

    In this article, Literacy 2.0 is defined in terms of Web 2.0 influences. Literacy 2.0 encompasses several major characteristics that distinguish it from traditional literacy practices (Literacy 1.0). For educational technology professionals, Literacy 2.0 skills become a critical means for developing lifelong learning.

  6. Linear and nonlinear transmission of Fe{sup 2+}-doped ZnSe crystals at a wavelength of 2940 nm in the temperature range 20–220 °C

    SciTech Connect

    Il'ichev, N N; Pashinin, P P; Gulyamova, E S; Bufetova, G A; Shapkin, P V; Nasibov, A S

    2014-03-28

    The linear and nonlinear transmission of Fe{sup 2+}:ZnSe crystals is measured at a wavelength of 2940 nm in the temperature range 20 – 220 °C. It is found that, with increasing temperature from 20 °C to 150 – 220 °C, the transmission of Fe{sup 2+}:ZnSe crystals decreases in the case of incident radiation with an intensity of ∼5.5 MW cm{sup -2} and increases in the case of radiation with an intensity of 28 kW cm{sup -2}. At a temperature of 220 °C, the linear transmission almost coincides with the nonlinear transmission. The transmission spectra of Fe{sup 2+}:ZnSe crystals at temperatures of 22 and 220 °C in the wavelength range 500 – 7000 nm are presented. (active media)

  7. Ion yields and erosion rates for Si{sub 1-x}Ge{sub x}(0<=x<=1) ultralow energy O{sub 2}{sup +} secondary ion mass spectrometry in the energy range of 0.25-1 keV

    SciTech Connect

    Morris, R. J. H.; Dowsett, M. G.

    2009-06-01

    We report the SIMS parameters required for the quantitative analysis of Si{sub 1-x}Ge{sub x} across the range of 0<=x<=1 when using low energy O{sub 2}{sup +} primary ions at normal incidence. These include the silicon and germanium secondary ion yield [i.e., the measured ion signal (ions/s)] and erosion rate [i.e., the speed at which the material sputters (nm/min)] as a function of x. We show that the ratio R{sub x} of erosion rates, Si{sub 1-x}Ge{sub x}/Si, at a given x is almost independent of beam energy, implying that the properties of the altered layer are dominated by the interaction of oxygen with silicon. R{sub x} shows an exponential dependence on x. Unsurprisingly, the silicon and germanium secondary ion yields are found to depart somewhat from proportionality to (1-x) and x, respectively, although an approximate linear relationship could be used for quantification across around 30% of the range of x (i.e., a reference material containing Ge fraction x would give reasonably accurate quantification across the range of +-0.15x). Direct comparison of the useful (ion) yields [i.e., the ratio of ion yield to the total number of atoms sputtered for a particular species (ions/atom)] and the sputter yields [i.e., the total number of atoms sputtered per incident primary ion (atoms/ions)] reveals a moderate matrix effect where the former decrease monotonically with increasing x except at the lowest beam energy investigated (250 eV). Here, the useful yield of Ge is found to be invariant with x. At 250 eV, the germanium ion and sputter yields are proportional to x for all x.

  8. PARTNERWORKSV2.0

    Energy Science and Technology Software Center (ESTSC)

    2000-04-12

    PartnerWorks Ver. 2.0 uses MAPI and OLE to tightly integrate the information system into the user's desktop. The applications are mail and fax enabled, and data can be linked or exported to and from all popular desktop applications at the push of a button. PartnerWorks converts financial data from Project Year to Fiscal Year. PartnerWorks also makes use of off-the-shelf software (Microsoft NT) encryption. PartnerWorks Ver, 2.0 automates the management of laboratory agreements with industry.more » PartnerWorks is a three-tier client server system. It uses MS SQL server (480 tables) as the central data repository for agreement information and document objects. The front-end applications consist of various MS Access applications. Data in remote systems is queried live or imported on a fixed schedule depending on the data type and volatility. All data is accessed via ODBC. This multi-front end application, multi-back end data source provides the end user with the illusion that all data exists in his or her custom application. PartnerWorks manages: Managing laboratory-partner agreement life cycle including contract and funding details (16 agreement-specific modules); Pending laboratory partnership agreements; Partner details for existing and potential partners; Potential agreement sources and partnership opportunities; Automating and warehousing the agreement documentation (document warehousing module); Automating standardized email communication for agreements; Enforcing business rules and work flow (action tracking module); Automated reporting including demand print, and schedule delivery (reporting module); Marketing intellectual property and past successes (Web module).« less

  9. PARTNERWORKSV2.0

    SciTech Connect

    George Longmire, SNL 4212; David Skousen, SNL 4212.

    2000-04-12

    PartnerWorks Ver. 2.0 uses MAPI and OLE to tightly integrate the information system into the user's desktop. The applications are mail and fax enabled, and data can be linked or exported to and from all popular desktop applications at the push of a button. PartnerWorks converts financial data from Project Year to Fiscal Year. PartnerWorks also makes use of off-the-shelf software (Microsoft NT) encryption. PartnerWorks Ver, 2.0 automates the management of laboratory agreements with industry. PartnerWorks is a three-tier client server system. It uses MS SQL server (480 tables) as the central data repository for agreement information and document objects. The front-end applications consist of various MS Access applications. Data in remote systems is queried live or imported on a fixed schedule depending on the data type and volatility. All data is accessed via ODBC. This multi-front end application, multi-back end data source provides the end user with the illusion that all data exists in his or her custom application. PartnerWorks manages: Managing laboratory-partner agreement life cycle including contract and funding details (16 agreement-specific modules); Pending laboratory partnership agreements; Partner details for existing and potential partners; Potential agreement sources and partnership opportunities; Automating and warehousing the agreement documentation (document warehousing module); Automating standardized email communication for agreements; Enforcing business rules and work flow (action tracking module); Automated reporting including demand print, and schedule delivery (reporting module); Marketing intellectual property and past successes (Web module).

  10. Wide-Band KB Optics for Spectro-Microscopy Imaging Applications in the 6-13 keV X-ray Energy Range

    SciTech Connect

    Ziegler, E.; De Panfilis, S.; Peverini, L.; Vaerenbergh, P. van; Rocca, F.

    2007-01-19

    We present a Kirkpatrick-Baez optics (KB) system specially optimized to operate in the 6-13 keV X-ray range, where valuable characteristic lines are present. The mirrors are coated with aperiodic laterally graded (Ru/B4C)35 multilayers to define a 15% energy bandpass and to gain flux as compared to total reflection mirrors. For any X-ray energy selected the shape of each mirror can be optimized with a dynamical bending system so as to concentrate the X-ray beam into a micrometer-size spot. Once the KB mirrors are aligned at the X-ray energy corresponding to the barycenter of the XAS spectrum to be performed they remain in a steady state during the micro-XAS scans to minimize beam displacements. Results regarding the performance of the wideband KB optics and of the spectro-microscopy setup are presented, including beam stability issues.

  11. ECO2N V2.0

    Energy Science and Technology Software Center (ESTSC)

    2015-02-01

    ECO2N V2.0 is a fluid property module for the TOUGH2 simulator (Version 2.1) that was designed for applications to geologic sequestration of CO2 in saline aquifers and enhanced geothermal reservoirs. ECO2N V2.0 is an enhanced version of the previous ECO2N V1.0 module (Pruess, 2005). It expands the temperature range up to about 300oC whereas V1.0 can only be used for temperatures below about 110oC. V2.0 includes a comprehensive description of the thermodynamic and thermophysical propertiesmore » of H2O - NaCl - CO2 mixtures, that reproduces fluid properties largely within experimental error for the temperature, pressure and salinity conditions 10 °C < T < 300 °C, P < 600 bar, and salinity up to halite saturation. This includes density, viscosity, and specific enthalpy of fluid phases as functions of temperature, pressure, and composition, as well as partitioning of mass components H2O, NaCl and CO2 among the different phases. In particular, V2.0 accounts for the effects of water on the thermophysical properties of the CO2-rich phase, which was ignored in V1.0, using a model consistent with the solubility models developed by Spycher and Pruess (2005, 2010). In terms of solubility models, V2.0 uses the same model for partitioning of mass components among the different phases (Spycher and Pruess, 2005) as V1.0 for the low temperature range (<99oC) but uses a new model (Spycher and Pruess, 2010) for the high temperature range (>109oC). In the transition range (99-109oC), a smooth interpolation is applied to estimate the partitioning as a function of the temperature. Flow processes can be modeled isothermally or non-isothermally, and phase conditions represented may include a single (aqueous or CO2-rich) phase, as well as two-phase (brine-CO2) mixtures. Fluid phases may appear or disappear in the course of a simulation, and solid salt may precipitate or dissolve. Note that the model cannot be applied to subcritical conditions that involves both liquid and gaseous CO2

  12. ECO2N V2.0

    SciTech Connect

    Pan, Lehua; Spycher, Nicolas; Doughty, Christine; Pruess, Karsten

    2015-02-01

    ECO2N V2.0 is a fluid property module for the TOUGH2 simulator (Version 2.1) that was designed for applications to geologic sequestration of CO2 in saline aquifers and enhanced geothermal reservoirs. ECO2N V2.0 is an enhanced version of the previous ECO2N V1.0 module (Pruess, 2005). It expands the temperature range up to about 300oC whereas V1.0 can only be used for temperatures below about 110oC. V2.0 includes a comprehensive description of the thermodynamic and thermophysical properties of H2O - NaCl - CO2 mixtures, that reproduces fluid properties largely within experimental error for the temperature, pressure and salinity conditions 10 °C < T < 300 °C, P < 600 bar, and salinity up to halite saturation. This includes density, viscosity, and specific enthalpy of fluid phases as functions of temperature, pressure, and composition, as well as partitioning of mass components H2O, NaCl and CO2 among the different phases. In particular, V2.0 accounts for the effects of water on the thermophysical properties of the CO2-rich phase, which was ignored in V1.0, using a model consistent with the solubility models developed by Spycher and Pruess (2005, 2010). In terms of solubility models, V2.0 uses the same model for partitioning of mass components among the different phases (Spycher and Pruess, 2005) as V1.0 for the low temperature range (<99oC) but uses a new model (Spycher and Pruess, 2010) for the high temperature range (>109oC). In the transition range (99-109oC), a smooth interpolation is applied to estimate the partitioning as a function of the temperature. Flow processes can be modeled isothermally or non-isothermally, and phase conditions represented may include a single (aqueous or CO2-rich) phase, as well as two-phase (brine-CO2) mixtures. Fluid phases may appear or disappear in the course of a simulation, and solid salt may precipitate or dissolve. Note that the model cannot be applied to subcritical conditions that involves both liquid and gaseous CO2 unless

  13. ART: Surveying the Local Universe at 2-11 keV

    NASA Technical Reports Server (NTRS)

    O'Dell, S. L.; Ramsey, B. D.; Adams, M. L.; Brandt, W. N.; Bubarev, M. V.; Hassinger, G.; Pravlinski, M.; Predehl, P.; Romaine, S. E.; Swartz, D. A.; Urry, C. M.; Vikhlinin, A.; Weisskopf, M. C.

    2008-01-01

    The Astronomical Rontgen Telescope (ART) is a medium-energy x-ray telescope system proposed for the Russian-led mission Spectrum Rontgen-Gamma (SRG). Optimized for performance over the 2-11-keV band, ART complements the softer response of the SRG prime instrument-the German eROSITA x-ray telescope system. The anticipated number of ART detections is 50,000-with 1,000 heavily-obscured (N(sub H)> 3x10(exp 23)/sq cm) AGN-in the SRG 4-year all-sky survey, plus a comparable number in deeper wide-field (500 deg(sup 2) total) surveys. ART's surveys will provide a minimally-biased, nearly-complete census of the local Universe in the medium-energy x-ray band (including Fe-K lines), at CCD spectral resolution. During long (approx.100-ks) pointed observations, ART can obtain statistically significant spectral data up to about 15 keY for bright sources and medium-energy x-ray continuum and Fe-K-line spectra of AGN detected with the contemporaneous NuSTAR hard-x-ray mission.

  14. Comparison of simulated and measured spectra from an X-ray tube for the energies between 20 and 35 keV

    NASA Astrophysics Data System (ADS)

    Yücel, M.; Emirhan, E.; Bayrak, A.; Ozben, C. S.; Yücel, E. Barlas

    2015-11-01

    Design and production of a simple and low cost X-ray imaging system that can be used for light industrial applications was targeted in the Nuclear Physics Laboratory of Istanbul Technical University. In this study, production, transmission and detection of X-rays were simulated for the proposed imaging device. OX/70-P dental tube was used and X-ray spectra simulated by Geant4 were validated by comparison with X-ray spectra measured between 20 and 35 keV. Relative detection efficiency of the detector was also determined to confirm the physics processes used in the simulations. Various time optimization tools were performed to reduce the simulation time.

  15. Measurement of the 20 and 90 keV resonances in the 18O(p,alpha)15N reaction via the Trojan horse method.

    PubMed

    La Cognata, M; Spitaleri, C; Mukhamedzhanov, A M; Irgaziev, B; Tribble, R E; Banu, A; Cherubini, S; Coc, A; Crucillà, V; Goldberg, V Z; Gulino, M; Kiss, G G; Lamia, L; Mrazek, J; Pizzone, R G; Puglia, S M R; Rapisarda, G G; Romano, S; Sergi, M L; Tabacaru, G; Trache, L; Trzaska, W; Tumino, A

    2008-10-10

    The 18O(p,alpha)15N reaction is of primary importance in several astrophysical scenarios, including fluorine nucleosynthesis inside asymptotic giant branch stars as well as oxygen and nitrogen isotopic ratios in meteorite grains. Thus the indirect measurement of the low energy region of the 18O(p,alpha)15N reaction has been performed to reduce the nuclear uncertainty on theoretical predictions. In particular the strength of the 20 and 90 keV resonances has been deduced and the change in the reaction rate evaluated. PMID:18999593

  16. Measurement of the 20 and 90 keV Resonances in the {sup 18}O(p,{alpha}){sup 15}N Reaction via the Trojan Horse Method

    SciTech Connect

    La Cognata, M.; Spitaleri, C.; Cherubini, S.; Crucilla, V.; Gulino, M.; Lamia, L.; Pizzone, R. G.; Puglia, S. M. R.; Rapisarda, G. G.; Romano, S.; Sergi, M. L.; Tumino, A.; Mukhamedzhanov, A. M.; Tribble, R. E.; Banu, A.; Goldberg, V. Z.; Tabacaru, G.; Trache, L.; Irgaziev, B.; Coc, A.

    2008-10-10

    The {sup 18}O(p,{alpha}){sup 15}N reaction is of primary importance in several astrophysical scenarios, including fluorine nucleosynthesis inside asymptotic giant branch stars as well as oxygen and nitrogen isotopic ratios in meteorite grains. Thus the indirect measurement of the low energy region of the {sup 18}O(p,{alpha}){sup 15}N reaction has been performed to reduce the nuclear uncertainty on theoretical predictions. In particular the strength of the 20 and 90 keV resonances has been deduced and the change in the reaction rate evaluated.

  17. Xenopatients 2.0

    PubMed Central

    Menendez, Javier A; Alarcón, Tomás; Corominas-Faja, Bruna; Cuyàs, Elisabet; López-Bonet, Eugeni; Martin, Ángel G; Vellon, Luciano

    2014-01-01

    stemness factors following the activation of phenotypic copies of specific cancer diseases might crucially evaluate a “reprogramming cure” for cancer. A new era of xenopatients 2.0 generated via nuclear reprogramming of the epigenetic landscapes of patient-derived cancer genomes might revolutionize the current personalized translational platforms in cancer research. PMID:24406535

  18. Experimentally determined density matrices for H( n =3) formed in H sup + -He collisions from 20 to 100 keV

    SciTech Connect

    Ashburn, J.R.; Cline, R.A.; van der Burgt, P.J.M.; Westerveld, W.B.; Risley, J.S. )

    1990-03-01

    Density matrices describing H({ital n}=3) atoms produced in collisions of 20- to 100-keV protons with He atoms have been determined experimentally. In the experiment the intensity and polarization of Balmer-{alpha} radiation emitted from a He gas cell are measured as a function of the strength of an externally applied electric field. Electric fields are applied in a direction either axial to or transverse to the proton beam. Density matrices are extracted by detailed analysis of the optical data. Data are obtained for each field direction and then analyzed, separately and in combination, to yield density matrices. Satisfactory agreement is found between density matrices determined from axial and transverse electric field data except at the lowest energies studied. Some nonzero density-matrix elements are determined more accurately using axial electric fields than with transverse fields, while other elements are more accurately determined using transverse electric fields. The combined analysis using data from both field directions gives a better determination of the density matrix than the separate data sets. Results for the H({ital n}=3) electron-transfer cross sections (relative to 3{ital s}), the electric dipole moment of the charge distribution {l angle}{bold d}{r angle}{sub {ital z}}, a first-order moment of the current distribution {l angle}{bold L}{times}{bold A}{r angle}{sub {ital z},{ital s}}, and the average coherence Tr({sigma}{sub 3}{sup 2}) are obtained. The experimental results are compared to two recent calculations using the augmented atomic orbital (AO+) theory and the continuum distorted-wave approximation with post-collision interaction theory, and to one recent experimental measurement of the diagonal density-matrix elements. Both theories show qualitative agreement with the general trends in the data. The AO+ method gives better quantitative agreement.

  19. CASPER Version 2.0

    NASA Technical Reports Server (NTRS)

    Chien, Steve; Rabideau, Gregg; Tran, Daniel; Knight, Russell; Chouinard, Caroline; Estlin, Tara; Gaines, Daniel; Clement, Bradley; Barrett, Anthony

    2007-01-01

    CASPER is designed to perform automated planning of interdependent activities within a system subject to requirements, constraints, and limitations on resources. In contradistinction to the traditional concept of batch planning followed by execution, CASPER implements a concept of continuous planning and replanning in response to unanticipated changes (including failures), integrated with execution. Improvements over other, similar software that have been incorporated into CASPER version 2.0 include an enhanced executable interface to facilitate integration with a wide range of execution software systems and supporting software libraries; features to support execution while reasoning about urgency, importance, and impending deadlines; features that enable accommodation to a wide range of computing environments that include various central processing units and random- access-memory capacities; and improved generic time-server and time-control features.

  20. Mass attenuation coefficient of binderless, pre-treated and tannin-based Rhizophora spp. particleboards using 16.59 - 25.26 keV photon energy range

    NASA Astrophysics Data System (ADS)

    Mohd Yusof, Mohd Fahmi; Hamid, Puteri Nor Khatijah Abdul; Bauk, Sabar; Hashim, Rokiah; Tajuddin, Abdul Aziz

    2015-04-01

    The Rhizophora spp. particleboards were fabricated using ≤ 104 µm particle size at three different fabrication methods; binderless, steam pre-treated and tannin-added. The mass attenuation coefficient of Rhizophora spp. particleboards were measured using x-ray fluorescent (XRF) photon from niobium, molybdenum, palladium, silver and tin metal plates that provided photon energy between 16.59 to 25.26 keV. The results were compared to theoretical values for water calculated using photon cross-section database (XCOM).The results showed that all Rhizophora spp. particleboards having mass attenuation coefficient close to calculated XCOM for water. Tannin-added Rizophora spp. particleboard was nearest to calculated XCOM for water with χ2 value of 13.008 followed by binderless Rizophora spp. (25.859) and pre-treated Rizophora spp. (91.941).

  1. Measurement of mass attenuation coefficients for four mixtures using X-rays from 13 keV up to 40 keV

    NASA Astrophysics Data System (ADS)

    Angelone, M.; Esposito, A.; Chiti, M.; Gentile, A.

    2001-06-01

    The total absorption coefficients for some selected organic compounds relevant to health physics, Triaflol BN (C 3H 4O 2) n, Triaflol TN (C 12H 18O 7) n, Kapton (C 44H 20O 10) n, and Melinex (C 10H 8N 4O 4) n were measured in the X-ray energy range from 13 keV up to about 40 keV using a collimator, high purity germanium detector with thin Be window and variable energy X-ray source. The measured values are compared with the theoretical ones obtained using the XCOM code. The agreement is generally good within a few percent.

  2. Learning to Apply Metrology Principles to the Measurement of X-ray Intensities in the 500 eV to 110 keV Energy Range

    SciTech Connect

    Haugh, M. J.; Pond, T.; Silbernagel, C.; Torres, P.; Marlett, K.; Goldin, F.; Cyr, S.

    2011-02-08

    National Security Technologies, LLC (NSTec), Livermore Operations, has two optical radiation calibration laboratories accredited by “the National Voluntary Laboratories Accreditation Program (NVLAP) which is the accrediting body of” the National Institute of Standards and Technology (NIST), and is now working towards accreditation for its X-ray laboratories. NSTec operates several laboratories with X-ray sources that generate X-rays in the energy range from 50 eV to 115 keV. These X-ray sources are used to characterize and calibrate diagnostics and diagnostic components used by the various national laboratories, particularly for plasma analysis on the Lawrence Livermore National Laboratory (LLNL) National Ignition Facility (NIF). Because X-ray photon flux measurement methods that can be accredited, i.e., traceable to NIST, have not been developed for sources operating in these energy ranges, NSTec, NIST, and the National Voluntary Accreditation Program (NVLAP) together have defined a path toward the development and validation of accredited metrology methods for X-ray energies. The methodology developed for the high energy X-ray (HEX) Laboratory was NSTec’s starting point for X-ray metrology accreditation and will be the basis for the accredited processes in the other X-ray laboratories. This paper will serve as a teaching tool, by way of this example using the NSTec X-ray sources, for the process and methods used in developing an accredited traceable metrology.

  3. High accuracy experimental determination of copper and zinc mass attenuation coefficients in the 100 eV to 30 keV photon energy range

    NASA Astrophysics Data System (ADS)

    Ménesguen, Y.; Gerlach, M.; Pollakowski, B.; Unterumsberger, R.; Haschke, M.; Beckhoff, B.; Lépy, M.-C.

    2016-02-01

    The knowledge of atomic fundamental parameters such as mass attenuation coefficients with low uncertainties, is of decisive importance in elemental quantification using x-ray fluorescence analysis techniques. Several databases are accessible and frequently used within a large community of users. These compilations are most often in good agreement for photon energies in the hard x-ray ranges. However, they significantly differ for low photon energies and around the absorption edges of any element. In a joint cooperation of the metrology institutes of France and Germany, mass attenuation coefficients of copper and zinc were determined experimentally in the photon energy range from 100 eV to 30 keV by independent approaches using monochromatized synchrotron radiation at SOLEIL (France) and BESSY II (Germany), respectively. The application of high-accuracy experimental techniques resulted in mass attenuation coefficient datasets determined with low uncertainties that are directly compared to existing databases. The novel datasets are expected to enhance the reliability of mass attenuation coefficients.

  4. Optical excitation function of H(1s-2p) produced by electron impact from threshold to 1.8 keV

    SciTech Connect

    James, G.K.; Slevin, J.A.; Shemansky, D.E.; McConkey, J.W.; Bray, I.; Dziczek, D.; Kanik, I.; Ajello, J.M.

    1997-02-01

    The optical excitation function of prompt Lyman-{alpha} radiation, produced by electron impact on atomic hydrogen, has been measured over the extended energy range from threshold to 1.8 keV. Measurements were obtained in a crossed-beams experiment using both magnetically confined and electrostatically focused electrons in collision with atomic hydrogen produced by an intense discharge source. A vacuum-ultraviolet monochromator system was used to measure the emitted Lyman-{alpha} radiation. The absolute H(1s-2p) electron impact excitation cross section was obtained from the experimental optical excitation function by normalizing to the accepted optical oscillator strength, with corrections for polarization and cascade. Our data are significantly different from the earlier experimental results and which are limited to energies below 200 eV. Statistical and known systematic uncertainties in our data range from {plus_minus}4{percent} near threshold to {plus_minus}2{percent} at 1.8 keV. Multistate coupling affecting the shape of the excitation function up to 1 keV impact energy is apparent in both the present experimental data and present theoretical results obtained with convergent close-coupling (CCC) theory. This shape function effect leads to an uncertainty in absolute cross sections at the 10{percent} level in the analysis of the experimental data. The derived optimized absolute cross sections are within 7{percent} of the CCC calculations over the 14 eV{endash}1.8 keV range. The present CCC calculations converge on the Bethe-Fano profile for H(1s-2p) excitation at high energy. For this reason agreement with the CCC values to within 3{percent} is achieved in a nonoptimal normalization of the experimental data to the Bethe-Fano profile. The fundamental H(1s-2p) electron impact cross section is thereby determined to an unprecedented accuracy over the 14 eV {endash} 1.8 keV energy range. (Abstract Truncated)

  5. Neutron capture and fission cross section of /sup 243/Am in the energy range from 5 to 250 keV

    SciTech Connect

    Wisshak, K.; Kappeler, F.

    1983-11-01

    The neutron capture and subthreshold fission cross section of /sup 243/Am was measured in the energy range from 5 to 250 keV using /sup 197/Au and /sup 235/U as the respective standards. Neutrons were produced via the /sup 7/Li(p,n) and the T(p,n) reaction with the Karlsruhe 3-MV pulsed Van de Graaff accelerator. Capture events were detected by two Moxon-Rae detectors with graphite and bismuth graphite converters, respectively. Fission events were registered by an Ne-213 liquid scintillator with pulse-shape discriminator equipment. Flight paths as short as 50 to 70 mm were used to obtain an optimum signal-to-background ratio. After correction for the different efficiency of the individual converter materials, the capture cross section could be determined with a total uncertainty of 3 to 6%. The respective values for the fission cross section are 8 to 12%. The results are compared to predictions of recent evaluations, which in some cases are severely discrepant.

  6. Time-resolved analysis of the X-ray emission of femtosecond-laser-produced plasmas in the 1.5-keV range

    NASA Astrophysics Data System (ADS)

    Bastiani-Ceccotti, S.; Audebert, P.; Nagels-Silvert, V.; Geindre, J. P.; Gauthier, J. C.; Adam, J. C.; Héron, A.; Chenais-Popovics, C.

    Recent experimental results on ion beams produced in high-intensity laser-solid interactions indicate the presence of very intense electric fields in the target. This suggests the possibility of efficiently heating a solid material by means of the fast electrons created during the laser-solid interactions and trapped in the target, rather than by the laser photons themselves. We tested this mechanism by irradiating very small cubic aluminum targets with the LULI 100-TW, 300-fs laser at 1.06-μm wavelength. X-ray spectra were measured with an ultra-fast streak camera, coupled to a conical Bragg crystal, providing spectra in the 1.5-keV range with high temporal and spectral resolution. The results indicate the creation of a hot plasma, but a very low coupling between the rapid electrons and the solid. A tentative explanation, in agreement with other experimental results and with preliminary particle-in-cell (PIC) simulations, points out the fatal role of the laser prepulse.

  7. Elastic and inelastic processes in H{sup +}+C{sub 2}H{sub 6} collisions below the 10-keV regime

    SciTech Connect

    Suzuki, Reiko; Rai, Sachchida N.; Liebermann, Heinz-Peter; Buenker, Robert J.; Pichl, Lukas; Kimura, Mineo

    2005-11-15

    Charge-transfer processes in collisions of H{sup +} ions with C{sub 2}H{sub 6} molecules are investigated theoretically below 10-keV collision energies within a molecular representation. Converged total as well as differential cross sections are obtained in this energy range within a discrete basis of electronic states computed by ab inito methods. The present collision system suggests that the combination of the Demkov-type and Landau-Zener-type mechanisms primarily governs the scattering dynamics for the flux exit from the initial channel. The present charge-transfer cross sections determined are found to agree very well with all available experimental data below a few keV, but begin to deviate above 3 keV, in which the present results slowly decrease, while measurements stay nearly constant. From the study of the electronic state calculation, we provide some information on fragmented species, which should help shed some light on the fragmentation mechanism and process of C{sub 2}H{sub 6}{sup +} ions produced after charge transfer. In addition, the vibrational effect of the initial target to charge transfer is examined.

  8. Improved energy of the 21.5 keV M1 + E2 nuclear transition in 151Eu

    NASA Astrophysics Data System (ADS)

    Inoyatov, A. Kh.; Kovalík, A.; Filosofov, D. V.; Ryšavý, M.; Perevoshchikov, L. L.; Baimukhanova, A.

    2016-05-01

    Using internal conversion electron spectroscopy, improved energy 21 541.5±0.5 eV was determined for the 21.5keV M1 + E2 nuclear transition in 151Eu populated in the electron capture decay of 151Gd . This value was found to agree well with the present adopted value but is much more accurate. A value of 0.0305±0.0011 derived for the E2 admixture parameter \\vertδ(E2/M1)\\vert from the measured conversion electron line intensities corresponds to the present adopted value. A possible effect of nuclear structure on the multipolarity of the 21.5 keV transition was also investigated.

  9. Library Instruction 2.0

    ERIC Educational Resources Information Center

    Bridgewater, Rachel; Deitering, Anne-Marie; Munro, Karen

    2009-01-01

    At the 2008 ALA Annual Conference, a wonderful Association of College and Research Libraries (ACRL) preconference was presented entitled "Library Instruction 2.0: Building Your Online Instruction Toolkit". The presentation was enlightening and provided numerous and valuable recommendations for Web 2.0 sites that can facilitate and enliven library…

  10. Ionic fragmentation of CO and H2O under impact of 10 keV electrons: kinetic energy release distributions

    NASA Astrophysics Data System (ADS)

    Singh, Raj; Bhatt, Pragya; Yadav, Namita; Shanker, R.

    2014-04-01

    Dissociative ionization of COq+ (q=2-4) and H2Oq+ (q=2-3) molecular ions produced from the collisions of CO and H2O with 10 keV electrons is studied using time-of-flight mass spectrometer and position sensitive detector with multi-hit ability, respectively. The kinetic energy release distributions for these channels are obtained. We found that a pure Coulomb explosion model is insufficient to explain the observed kinetic release distributions for the Coulomb explosion channels. A detail of this study is given in references [3, 4].

  11. Mid-crust fluid and water-rock interaction kinetic experiments and their geophysical significance: 2. syenite-water interaction in the temperature range from 20 to 435°C

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Zhang, R.; Hu, S.

    2013-12-01

    The kinetics Experiments on syenite-water interactions were carried out in a horizontally-mounted packed bed reactor in the temperature range from 20 to 435°C and at pressures of 23-36 MPa. The net dissolution rates (mol/minute/m2 or mol/s/m2) normalized to their specific surface area (A) are calculated using the following expression: -r = (Ci - C0) / [t (A/V) υi] where Ci is the output concentration of species i, C0 is the initial concentration of species i, A is the total reactive surface area of the mineral (m2), t is the average fluid residence time, and V is the volume of the pressure vessel (mL), i.e., liquid volume. υi is the stoichiometric coefficient of the ith element in the mineral formula (Zhang R.H. et al., 2000). Thus, the dissolution rates of syenite in water and the electric conductance can be measured simultaneously at temperature from 20 to 435°C and at pressure from 23-36MPa. The results indicated that the release rates of Si, Al, K and Na of the syenite increase with increasing temperature, and reached maximum values at 400°C. The release rates of Ca, Mg reached maximum values at 200°C. The release rates of Fe reached maximum values at 374°C. Another important impact factor of the reaction between syenite and water is pressure. The release rates of Si did not vary with pressure, as pressure was changed from 23 to 36 MPa. The release rates of K and Al in syenite increase with increasing pressure. The maximum release rates (rM) of Ni and Cu are reached at 300°C, 23 MPa, and the rM (Zn) is at 374°C, 23MPa. But the rM (Mn) is reached at low temperature (25°C) and 31MPa. The rM (Sr) and rM (Ba) are present at low temperature (20-200°C) and 23 MPa, The rM (Mo) is at 350°C and 23 MPa. The rM of Pb is present at 400°C, 23 MPa. The most metals (Si, Ca and ore-forming elements) easily release into aqueous solutions at 23 MPa. If increasing pressure from 23 to 36 MPa, most molar concentration ratio of metal Mi vs Si, Mi/MSi in the effluent

  12. Do the O2 Schumann-Runge Bands Participate in keV Collision-Induced Dissociation Experiments?

    NASA Astrophysics Data System (ADS)

    Lin, Yawei; Mayer, Paul M.

    2011-01-01

    In high-energy (keV) CID experiments, oxygen has the unique ability to enhance specific ion fragmentation pathways that lie within a relatively narrow band of activation energy. It has been previously proposed that this oxygen-enhanced dissociation phenomenon is due to the participation of the {{O}_{{2}}}{B}{ ^{{3}}}{Σ_{{u}}}^{ + } - {X}{ ^{{3}}}{Σ_{{g}}}^{ - } (Schumann-Runge) system in the collision complex. During the collision, oxygen is first excited to its {B}{ ^{{3}}}{Σ_{{u}}}^{ + } state before it returns this energy to the projectile ion. This energy drives the nonstatistical dissociation of the projectile provided there is an energetically accessible pathway in resonance with the absorbed radiation. To probe the validity of this hypothesis, a modified VG-ZAB mass spectrometer was used to observe the photon emissions from keV collisions of a selection of projectile ions with O2 target gas. By studying the resulting collision-induced emission (CIE) spectra, a second potential mechanism came to light, one that involves the near-isoenergetic O2 +. A 2Πu→X 2 Πg state transition.

  13. Do the O2 Schumann-Runge bands participate in keV collision-induced dissociation experiments?

    PubMed

    Lin, Yawei; Mayer, Paul M

    2011-01-01

    In high-energy (keV) CID experiments, oxygen has the unique ability to enhance specific ion fragmentation pathways that lie within a relatively narrow band of activation energy. It has been previously proposed that this oxygen-enhanced dissociation phenomenon is due to the participation of the O(2) B(3)Σ(u)(+) - X(3)Σ(g)(-) (Schumann-Runge) system in the collision complex. During the collision, oxygen is first excited to its [Formula: see text] state before it returns this energy to the projectile ion. This energy drives the nonstatistical dissociation of the projectile provided there is an energetically accessible pathway in resonance with the absorbed radiation. To probe the validity of this hypothesis, a modified VG-ZAB mass spectrometer was used to observe the photon emissions from keV collisions of a selection of projectile ions with O(2) target gas. By studying the resulting collision-induced emission (CIE) spectra, a second potential mechanism came to light, one that involves the near-isoenergetic O(2) (+.) A (2)Π(u)→X (2) Π(g) state transition. PMID:21472546

  14. Spectral reflectance change and luminescence of selected salts during 2-10 KeV proton bombardment - Implications for Io

    NASA Technical Reports Server (NTRS)

    Nelson, R. M.; Nash, D. B.

    1979-01-01

    Radiation damage and luminescence caused by magnetospheric charged particles have been suggested by several investigators as mechanisms that are capable of explaining some of the peculiar spectral/albedo features of Io. In the present paper, this possibility is pursued by measuring the UV-visual spectral reflectance and luminescent efficiency of several proposed Io surface constituents during 2 to 10 keV proton irradiation at room and low temperatures. The luminescence efficiencies of pure samples, studied in the laboratory, suggest that charged-particle induced luminescence from Io's surface might be observable by spacecraft such as Voyager when viewing Io's dark side.

  15. Measurement of the x-ray mass attenuation coefficient and determination of the imaginary component of the atomic form factor of molybdenum over the 13.5-41.5-keV energy range

    NASA Astrophysics Data System (ADS)

    de Jonge, Martin D.; Tran, Chanh Q.; Chantler, Christopher T.; Barnea, Zwi; Dhal, Bipin B.; Cookson, David J.; Lee, Wah-Keat; Mashayekhi, Ali

    2005-03-01

    We use the x-ray extended-range technique (XERT) [Chantler , Phys. Rev. A 64, 062506 (2001)] to measure the mass attenuation coefficients of molybdenum in the x-ray energy range of 13.5-41.5keV to 0.02-0.15 % accuracy. Measurements made over an extended range of the measurement parameter space are critically examined to identify, quantify, and correct where necessary a number of experimental systematic errors. These results represent the most extensive experimental data set for molybdenum and include absolute mass attenuation coefficients in the regions of the x-ray absorption fine structure (XAFS) and x-ray-absorption near-edge structure (XANES). The imaginary component of the atomic form-factor f2 is derived from the photoelectric absorption after subtracting calculated Rayleigh and Compton scattering cross sections from the total attenuation. Comparison of the result with tabulations of calculated photoelectric absorption coefficients indicates that differences of 1-15 % persist between the calculated and observed values.

  16. A multilayer grating with a novel layer structure for a flat-field spectrograph attached to transmission electron microscopes in energy region of 2-4 keV

    SciTech Connect

    Imazono, T.; Koike, M.; Koeda, M.; Nagano, T.; Sasai, H.; Oue, Y.; Yonezawa, Z.; Kuramoto, S.; Terauchi, M.; Takahashi, H.; Handa, N.; Murano, T.

    2012-05-17

    A multilayer mirror with a novel layer structure to uniformly enhance the reflectivity in a few keV energy range at a fixed angle of incidence is invented and applied to a multilayer grating for use in a flat-field spectrograph attached to a conventional electron microscope. The diffraction efficiency of the fabricated multilayer grating having the new layer structure is evaluated at the angle of incidence of 88.65 deg. in the energy region of 2.1-4.0 keV. It is shown that the multilayer grating is effective to uniformly enhance the diffraction efficiency and able to be practically used in this energy region.

  17. Implantation-induced nonequilibrium reaction between Zn ions of 60 keV and SiO{sub 2} target

    SciTech Connect

    Amekura, H.; Yoshitake, M.; Plaksin, O. A.; Kishimoto, N.; Buchal, Ch.; Mantl, S.

    2007-08-06

    Silica glass (SiO{sub 2}) was implanted with 60 keV Zn{sup +} ions to a fluence of 1.0x10{sup 17} ions/cm{sup 2}, and the chemical states were investigated along the depth in as-implanted state by x-ray excited Auger electron spectroscopy and x-ray photoelectron spectroscopy. The metallic Zn and Zn{sub 2}SiO{sub 4} phases were found to have, respectively, formed in the shallow and deep regions of the SiO{sub 2}, whereas thermodynamics predicts the Zn phase only. Oxygen atoms in SiO{sub 2} are preferentially displaced to the deeper region because of the lighter mass. The excess oxygen in the deep region and athermal energy from the implantation drive the formation of Zn{sub 2}SiO{sub 4}.

  18. Experimental and theoretical studies of the He(2+)-He system - Differential cross sections for direct, single-, and double-charge-transfer scattering at keV energies

    NASA Technical Reports Server (NTRS)

    Gao, R. S.; Dutta, C. M.; Lane, N. F.; Smith, K. A.; Stebbings, R. F.; Kimura, M.

    1992-01-01

    Measurements and calculations of differential cross sections for direct scattering, single-charge transfer, and double-charge transfer in collisions of 1.5-, 2.0-, 6.0-, and 10.0-keV (He-3)2+ with an He-4 target are reported. The measurements cover laboratory scattering angles below 1.5 deg with an angular resolution of about 0.03 deg. A quantum-mechanical molecular-state representation is employed in the calculations; in the case of single-charge transfer a two-state close-coupling calculation is carried out taking into account electron-translation effects. The theoretical calculations agree well with the experimental results for direct scattering and double-charge transfer. The present calculation identifies the origins of oscillatory structures observed in the differential cross sections.

  19. Measurement of X-ray mass attenuation coefficients in biological and geological samples in the energy range of 7-12keV.

    PubMed

    Trunova, Valentina; Sidorina, Anna; Kriventsov, Vladimir

    2014-10-17

    Information about X-ray mass attenuation coefficients in different materials is necessary for accurate X-ray fluorescent analysis. The X-ray mass attenuation coefficients for energy of 7-12keV were measured in biological (Mussel and Oyster tissues, blood, hair, liver, and Cabbage leaves) and geological (Baikal sludge, soil, and Alaskite granite) samples. The measurements were carried out at the EXAFS Station of Siberian Synchrotron Radiation Center (VEPP-3). Obtained experimental mass attenuation coefficients were compared with theoretical values calculated for some samples. PMID:25464176

  20. The Average 0.5-200 keV Spectrum of AGNs at 0

    NASA Astrophysics Data System (ADS)

    Ballantyne, David R.

    2013-04-01

    The X-ray spectra of AGNs span nearly three decades in energy and are comprised of many separate components: a power-law with a high energy cutoff, reflection from the accretion disk as well as distant material, and, in many cases, a soft excess. Aside from a small number of bright sources observed with BeppoSAX, the full energy range of AGN spectra has only been studied in piecemeal by a fleet of X-ray observatories that can only focus on a small part of the entire spectrum. Therefore, while catalogues of the spectral properties of hundreds of AGNs have been published in different energy bands, these results are isolated from one another and a clear picture of the broadband spectral properties of typical AGNs remains elusive. In this work, we make use of the 0 X-ray luminosity functions of AGNs in the 0.5-2 keV, 2-10 keV, 3-20 keV, 15-55 keV and 14-195 keV bands to construct the spectral model of an average AGN that can simultaneously account for all 5 luminosity functions. Enhanced iron abundances, disk reflection, and the presence or absence of the X-ray Baldwin Effect are considered, along with the traditional parameters of photon index and cutoff energy. Applications to X-ray background modelling and AGN physics are discussed.

  1. Analysis of photon emission from 50--350-keV proton impact on H{sub 2}O

    SciTech Connect

    Goldman, Benjamin D.; Timpone, Stephanie A.; Monce, Michael N.; Mitchell, Laurel; Griffin, Brian

    2011-04-15

    We have measured photon emission cross sections from neutral fragments produced by collisions of 50-350 keV protons with H{sub 2}O molecules. Balmer {alpha}-{delta} emissions from both the target and projectile were recorded. We also analyzed A {sup 2}{Sigma}{sup +}-X {sup 2}{Pi} (0,0) and (1,0) emission from the excited OH fragment produced during target dissociation. Trends in the cross sections revealed two key properties of the collision process: (1) The Bethe theory accurately describes target emission from both H and OH fragments and (2) the ratio of any two Balmer emission cross sections for both the target and projectile can be approximated by simple functions of the respective optical oscillator strengths. Finally, we provide the Bethe fit parameters necessary to calculate the target emission cross sections at all nonrelativistic impact energies.

  2. Academic Leadership 2.0

    ERIC Educational Resources Information Center

    Buller, Jeffrey L.

    2013-01-01

    Academic Leadership 2.0 means making an administrative partnership with the faculty the cornerstone of an institution's culture. Administrators have to stop thinking of themselves as operating on a different level from the faculty. The fear many administrators have is that if they demonstrate their willingness to advocate for the faculty, the…

  3. Revisiting the relationship between 6 μm and 2-10 keV continuum luminosities of AGN

    NASA Astrophysics Data System (ADS)

    Mateos, S.; Carrera, F. J.; Alonso-Herrero, A.; Rovilos, E.; Hernán-Caballero, A.; Barcons, X.; Blain, A.; Caccianiga, A.; Della Ceca, R.; Severgnini, P.

    2015-05-01

    We have determined the relation between the AGN luminosities at rest-frame 6 μm associated with the dusty torus emission and at 2-10 keV energies using a complete, X-ray-flux-limited sample of 232 AGN drawn from the Bright Ultra-hard XMM-Newton Survey. The objects have intrinsic X-ray luminosities between 1042 and 1046 erg s-1 and redshifts from 0.05 to 2.8. The rest-frame 6 μm luminosities were computed using data from the Wide-field Infrared Survey Explorer and are based on a spectral energy distribution decomposition into AGN and galaxy emission. The best-fitting relationship for the full sample is consistent with being linear, L6 μm ∝ L_{2-10 keV}^{0.99± 0.03}, with intrinsic scatter, Δ log L6 μm ˜ 0.35 dex. The L_{6 μ m}/L_{2-10 keV} luminosity ratio is largely independent of the line-of-sight X-ray absorption. Assuming a constant X-ray bolometric correction, the fraction of AGN bolometric luminosity reprocessed in the mid-IR decreases weakly, if at all, with the AGN luminosity, a finding at odds with simple receding torus models. Type 2 AGN have redder mid-IR continua at rest-frame wavelengths <12 μm and are overall ˜1.3-2 times fainter at 6 μm than type 1 AGN at a given X-ray luminosity. Regardless of whether type 1 and type 2 AGN have the same or different nuclear dusty toroidal structures, our results imply that the AGN emission at rest-frame 6 μm is not isotropic due to self-absorption in the dusty torus, as predicted by AGN torus models. Thus, AGN surveys at rest-frame ˜6 μm are subject to modest dust obscuration biases.

  4. CO2 laser ranging systems study

    NASA Technical Reports Server (NTRS)

    Filippi, C. A.

    1975-01-01

    The conceptual design and error performance of a CO2 laser ranging system are analyzed. Ranging signal and subsystem processing alternatives are identified, and their comprehensive evaluation yields preferred candidate solutions which are analyzed to derive range and range rate error contributions. The performance results are presented in the form of extensive tables and figures which identify the ranging accuracy compromises as a function of the key system design parameters and subsystem performance indexes. The ranging errors obtained are noted to be within the high accuracy requirements of existing NASA/GSFC missions with a proper system design.

  5. Personal dose equivalent conversion coefficients for neutron fluence over the energy range of 20 to 250 MeV

    SciTech Connect

    Mclean, Thomas D; Justus, Alan L; Gadd, S Milan; Olsher, Richard H; Devine, Robert T

    2009-01-01

    Monte Carlo simulations were performed to extend existing neutron personal dose equivalent fluence-to-dose conversion coefficients to an energy of 250 MeV. Presently, conversion coefficients, H(p,slab)(10,alpha)/Phi, are given by ICRP-74 and ICRU-57 for a range of angles of radiation incidence (alpha = 0, 15, 30, 45, 60 and 75 degrees ) in the energy range from thermal to 20 MeV. Standard practice has been to base operational dose quantity calculations <20 MeV on the kerma approximation, which assumes that charged particle secondaries are locally deposited, or at least that charged particle equilibrium exists within the tally cell volume. However, with increasing neutron energy the kerma approximation may no longer be valid for some energetic secondaries such as protons. The Los Alamos Monte Carlo radiation transport code MCNPX was used for all absorbed dose calculations. Transport models and collision-based energy deposition tallies were used for neutron energies >20 MeV. Both light and heavy ions (HIs) (carbon, nitrogen and oxygen recoil nuclei) were transported down to a lower energy limit (1 keV for light ions and 5 MeV for HIs). Track energy below the limit was assumed to be locally deposited. For neutron tracks <20 MeV, kerma factors were used to obtain absorbed dose. Results are presented for a discrete set of angles of incidence on an ICRU tissue slab phantom.

  6. Personal dose equivalent conversion coefficients for neutron fluence over the energy range of 20-250 MeV.

    PubMed

    Olsher, R H; McLean, T D; Justus, A L; Devine, R T; Gadd, M S

    2010-03-01

    Monte Carlo simulations were performed to extend existing neutron personal dose equivalent fluence-to-dose conversion coefficients to an energy of 250 MeV. Presently, conversion coefficients, H(p,slab)(10,alpha)/Phi, are given by ICRP-74 and ICRU-57 for a range of angles of radiation incidence (alpha = 0, 15, 30, 45, 60 and 75 degrees ) in the energy range from thermal to 20 MeV. Standard practice has been to base operational dose quantity calculations <20 MeV on the kerma approximation, which assumes that charged particle secondaries are locally deposited, or at least that charged particle equilibrium exists within the tally cell volume. However, with increasing neutron energy the kerma approximation may no longer be valid for some energetic secondaries such as protons. The Los Alamos Monte Carlo radiation transport code MCNPX was used for all absorbed dose calculations. Transport models and collision-based energy deposition tallies were used for neutron energies >20 MeV. Both light and heavy ions (HIs) (carbon, nitrogen and oxygen recoil nuclei) were transported down to a lower energy limit (1 keV for light ions and 5 MeV for HIs). Track energy below the limit was assumed to be locally deposited. For neutron tracks <20 MeV, kerma factors were used to obtain absorbed dose. Results are presented for a discrete set of angles of incidence on an ICRU tissue slab phantom. PMID:19887515

  7. The response of a radiation resistant ceramic scintillator (Al{sub 2}O{sub 3}:Cr) to low energy ions (0-60 keV)

    SciTech Connect

    Jimenez-Rey, D.; Zurro, B.; McCarthy, K. J.; Baciero, A.; Garcia, G.

    2008-10-15

    This work extends a previous study on ionoluminescence of a radiation-hard ceramic scintillator, Al{sub 2}O{sub 3}:Cr, to ions accelerated to keV energies [K. J. McCarthy et al., J. Nucl. Mater. 321, 78 (2003)]. It is motivated by the identification of this material as a promising candidate for use in the fast-ion-loss detector for ITER [for the range of thermal (low energy) and suprathermal ions]. In the paper we quantify and compare its ionoluminescence with that of some common luminescent materials (YAG:Ce and ruby) when irradiated by H{sup +} ions accelerated to {<=}60 keV using a purpose built laboratory setup. Next, studies are made on the ceramic to quantify its response as a function of incident ion mass, i.e., to He{sup +}. For this, the absolute luminosities of the material are estimated in terms of the number of photons emitted per incident ion as a function of energy. Moreover, the radiation hardness and postirradiation recovery of the ceramic are investigated. Finally, from the studies it can be concluded that the ceramic ruby is a good candidate for detecting low energy ions as long as its temporal response (approximately several milliseconds) is not a constraint for specific ion measurements.

  8. Channel electron multiplier efficiency for protons of 0.2-10 keV.

    NASA Technical Reports Server (NTRS)

    Iglesias, G. E.; Mcgarity, J. O.

    1971-01-01

    The initial results of absolute proton efficiency measurements made in an auroral particle study by sounding rockets are given. The measurements were made at several counting rates from 1000 to 40,000 counts/sec on rocket-borne equipment. The results agree with those of Egidi et al. (1969) in the high energy range and show a disagreement at low energies.

  9. Differential cross sections for single ionization of H{sub 2} by 75-keV proton impact

    SciTech Connect

    Chowdhury, U.; Schulz, M.; Madison, D. H.

    2011-03-15

    We have calculated triply differential cross sections (TDCS) and doubly differential cross sections (DDCS) for single ionization of H{sub 2} by 75-keV proton impact using the molecular three-body distorted-wave-eikonal initial-state (M3DW-EIS) approach. Previously published measured DDCS (differential in the projectile scattering angle and integrated over the ejected electron angles) found pronounced structures at relatively large angles that were interpreted as an interference resulting from the two-centered potential of the molecule. Theory treating H{sub 2} as atomic H multiplied by a molecular interference factor only predicts the observed structure when assumptions are made about the molecular orientation. Here we apply the M3DW-EIS method, which does not rely on such an ad hoc approach, but rather treats the interference from first principles.

  10. Calculations of electron stopping powers for 41 elemental solids over the 50 eV to 30 keV range with the full Penn algorithm

    NASA Astrophysics Data System (ADS)

    Shinotsuka, H.; Tanuma, S.; Powell, C. J.; Penn, D. R.

    2012-01-01

    We present mass collision electron stopping powers (SPs) for 41 elemental solids (Li, Be, graphite, diamond, glassy C, Na, Mg, Al, Si, K, Sc, Ti, V, Cr, Fe, Co, Ni, Cu, Ge, Y, Nb, Mo, Ru, Rh, Pd, Ag, In, Sn, Cs, Gd, Tb, Dy, Hf, Ta, W, Re, Os, Ir, Pt, Au, and Bi) that were calculated from experimental energy-loss-function data with the full Penn algorithm for electron energies between 50 eV and 30 keV. Improved sets of energy-loss functions were used for 19 solids. Comparisons were made of these SPs with SPs calculated with the single-pole approximation, previous SP calculations, and experimental SPs. Generally satisfactory agreement was found with SPs from the single-pole approximation for energies above 100 eV, with other calculated SPs, and with measured SPs.

  11. Introducing Science 2.0!

    ERIC Educational Resources Information Center

    Brunsell, Eric; Horejsi, Martin

    2010-01-01

    The internet of the mid-to-late 1990s was defined by static web pages created by people with specialized technical skills. Today, that barrier has been all but eliminated with the emergence of easy-to-use online tools for creating and sharing content. "Web 2.0," or the read/write web, has dramatically altered the way we communicate and share…

  12. Autogen Version 2.0

    NASA Technical Reports Server (NTRS)

    Gladden, Roy

    2007-01-01

    Version 2.0 of the autogen software has been released. "Autogen" (automated sequence generation) signifies both a process and software used to implement the process of automated generation of sequences of commands in a standard format for uplink to spacecraft. Autogen requires fewer workers than are needed for older manual sequence-generation processes and reduces sequence-generation times from weeks to minutes.

  13. Double ionization of helium by 2-keV electrons in equal- and unequal-energy configurations

    NASA Astrophysics Data System (ADS)

    Ambrosio, M. J.; Mitnik, D. M.; Dorn, A.; Ancarani, L. U.; Gasaneo, G.

    2016-03-01

    We present theoretical and experimental fully differential cross sections, in coplanar scattering geometry, for the double ionization of helium by electron impacting at 2 keV. The observed structures for both equal and unequal sharing of the excess energy are analyzed. Although the incident energy could, in principle, be regarded as high enough for the applicability of the first Born approximation in the projectile-target interaction, the experimental cross sections, measured with a COLTRIMS apparatus, show that further orders' effects can be appreciated. The theoretical cross sections are calculated with the generalized Sturmian functions method, which exactly solves the three-body problem that stems from a first-order projectile-target perturbative treatment.

  14. Electron Flux Models at GEO: 30 keV - 600 keV

    NASA Astrophysics Data System (ADS)

    Boynton, R.; Balikhin, M. A.; Sibeck, D. G.; Walker, S. N.; Ganushkina, N. Y.

    2015-12-01

    Forecast models are developed for the electron fluxes measured by the Magnetospheric Electron Detector (MagED) onboard the Geostationary Operational Environmental Satellite (GOES) 13. The models employ solar wind and geomagnetic indices as inputs to produce a forecast of the electron flux at Geostationary Earth Orbit (GEO) for five energy ranges from 30 keV - 600 keV. All of these models will be implemented in real time to forecast the electron fluxes on the PROGRESS project website (https://ssg.group.shef.ac.uk/progress2/html/index.phtml).

  15. SMM observations of gamma-ray transients. 2: A search for gamma-ray lines between 400 and 600 keV from the Crab Nebula

    NASA Technical Reports Server (NTRS)

    Harris, Michael J.; Share, Gerald H.; Leising, Mark D.

    1994-01-01

    We have search spectra obtained by the Solar Maximum Mission Gamma-Ray Spectrometer during 1981-1988 for evidence of transient gamma-ray lines from the Crab Nebula which have been reported by previous experiments at energies 400-460 keV and 539 keV. We find no evidence for significant emission in any of these lines on time scales between aproximately 1 day and approximately 1 yr. Our 3 sigma upper limits on the transient flux during 1 d intervals are approximately equal to 2.2 x 10(exp -3) photons/sq cm/s for narrow lines at any energy, and approximately equal to 2.9 x 10(exp -3) photons/sq cm/s for the 539 keV line if it is as broad as 42 keV Full Width at Half Maximum (FWHM). We also searched our data during the approximately 5 hr period on 1981 June 6 during which Owens, Myers, & Thompson (1985) reported a strong line at 405 keV. We detected no line down to a 3 upper sigma limit of 3.3 x 10(exp -3) photons/sq cm/s in disagreement with the flux 7.2 +/- 2.1 x 10(exp -3) photos/sq cm/s measured by Owens et al.

  16. First observation of {alpha} decay of {sup 190}Pt to the first excited level (E{sub exc}=137.2 keV) of {sup 186}Os

    SciTech Connect

    Belli, P.; Bernabei, R.; Cappella, F.; Cerulli, R.; Laubenstein, M.; Nisi, S.; Danevich, F. A.; Nagorny, S. S.; Polischuk, O. G.; Tretyak, V. I.; Incicchitti, A.

    2011-03-15

    The {alpha} decays of naturally occurring platinum isotopes, which are accompanied by the emission of {gamma} quanta, have been searched for deep underground (3600 m water equivalent) at the Gran Sasso National Laboratories of the INFN (Italy). A sample of Pt with a mass of 42.5 g and a natural isotopic composition has been measured with a low background HP Ge detector (468 cm{sup 3}) during 1815 h. The {alpha} decay of {sup 190}Pt to the first excited level of {sup 186}Os (J{sup {pi}}=2{sup +}, E{sub exc}=137.2 keV) has been observed for the first time, with the half-life determined as T{sub 1/2}=2.6{sub -0.3}{sup +0.4}(stat.){+-}0.6(syst.)x10{sup 14} yr. The T{sub 1/2} limits for the {alpha} decays of other Pt isotopes have been determined at the level of T{sub 1/2}{approx_equal}10{sup 16}-10{sup 20} yr. These limits have been set for the first time or they are better than those known from earlier experiments.

  17. A photoluminescence study of CuInSe2 single crystals ion implanted with 5 keV hydrogen

    NASA Astrophysics Data System (ADS)

    Yakushev, M. V.; Krustok, J.; Grossberg, M.; Volkov, V. A.; Mudryi, A. V.; Martin, R. W.

    2016-03-01

    CuInSe2 single crystals ion implanted with 5 keV hydrogen at doses from 3  ×  1014 to 1016 cm-2 are studied by photoluminescence (PL). The PL spectra before and after implantation reveal two bands, a main dominant band centred at 0.96 eV and a lower intensity band centred at 0.93 eV. Detailed analysis of the shape of these bands, their temperature and excitation intensity dependencies allow the recombination mechanisms to be identified as band-to-tail (BT) and band-to-impurity (BI), respectively. The implantation causes gradual red shifts of the bands increasing linearly with the dose. The average depth of potential fluctuations is also estimated to increase with the dose and saturates for doses above 1015 cm-2. A model is proposed which associates the potential fluctuations with the antisite defects copper on indium site and indium on copper site. The saturation is explained by full randomization of copper and indium atoms on the cation sub-lattice.

  18. Experimental and MC determination of HPGe detector efficiency in the 40-2754 keV energy range for measuring point source geometry with the source-to-detector distance of 25 cm.

    PubMed

    Dryak, Pavel; Kovar, Petr

    2006-01-01

    A precise model of a 40% relative efficiency p-type HPGe detector was created for photon detection efficiency calculation using the MCNP code. All detector parameters were determined by different experiments. No experimental calibration points were used for the modification of detector parameters. The model was validated by comparing calculated and experimental full energy peak efficiencies in the 40-2754 keV energy range, for point-source geometry with the source-to-detector distance of 25 cm. PMID:16564693

  19. Neutron capture cross sections of natural Yb, /sup 170/Yb, /sup 175/Lu, and /sup 184/W in the energy range from 5 to 200 keV for the /sup 176/Lu-chronometer

    SciTech Connect

    Beer, H.; Wisshak, K.; Kaeppeler, F.

    1980-09-01

    The neutron capture cross sections of natural Yb, /sup 170/Yb, /sup 175/Lu and /sup 184/W have been measured in the keV neutron energy range with a pulsed Van de Graaff accelerator using the kinematically collimated neutron beam from the /sup 7/Li(p,n) and the T(p,n) reaction. Prompt capture gamma rays were registered by a Moxon-Rae detector. All measurements were performed in a single run relative to the /sup 197/Au cross section as a standard. The cross sections of /sup 175/Lu and /sup 170/Yb were used to investigate the /sup 176/Lu-cosmic clock.

  20. VizieR Online Data Catalog: 2-10keV luminosity function of AGN (Ranalli+, 2016)

    NASA Astrophysics Data System (ADS)

    Ranalli, P.; Koulouridis, E.; Georgantopoulos, I.; Fotopoulou, S.; Hsu, L.-T.; Salvato, M.; Comastri, A.; Pierre, M.; Cappelluti, N.; Carrera, F. J.; Chiappetti, L.; Clerc, N.; Gilli, R.; Iwasawa, K.; Pacaud, F.; Paltani, S.; Plionis, E.; Vignali, C.

    2016-02-01

    The XMM-LSS, XMM-CDFS, and XMM-COSMOS are three surveys with complementary properties in terms of luminosity and redshift coverage. We used these three surveys to derive Bayesian estimates of the unabsorbed luminosity function (LF) of AGN in the 2-10keV band. The LF estimates are presented as a set of samples from the posterior probability distribution of the LF parameters. The LF is parameterised as a double power-law, with either the luminosity and density evolution (LADE) model, or the luminosity-dependent density evolution (LDDE) model. The double power-law is described by Eq.(10) in the paper. The LADE and LDDE models are described by Eqs.(11-14) and Eqs.(15-17), respectively. A Fortran 2008 implementation of these models can be found in file src2/lumf_funcs.f90 of the LFTools package, in the classes doublepowerlaw, ladevol, and lddevol (see the paper). (8 data files).

  1. Cross calibration of AGFA-D7 x-ray film against direct exposure film from 2 to 8.5 keV using laser generated x-rays

    NASA Astrophysics Data System (ADS)

    Kyrala, George A.

    2006-05-01

    Direct exposure film (DEF) is being discontinued. DEF film has been the workhorse in inertial confinement fusion (ICF) research and is used to record x-ray images and spectra. A previous search for a replacement [K. M. Chandler et al., Rev. Sci. Instrum. 76, 113111 (2005)] did not consider AGFA film. We present comparisons using the results of measurements using AGFA-D7 film, XAR, TMG, and Biomax-MS films in the same spectrometer recording a gold spectrum in the 2-4keV range and the iron spectrum in the 5-8.5keV range. AGFA film was found to have some unique properties useful in x-ray spectroscopy and imaging, especially when signal strength is not a concern.

  2. Partial-ionization cross sections of a CO{sub 2} molecule due to impact of 10-26-keV electrons

    SciTech Connect

    Bhatt, Pragya; Singh, Raj; Yadav, Namita; Shanker, R.

    2010-10-15

    Experimental data on total- and partial-ionization cross sections of ionic fragments of CO{sub 2} molecule produced by impact of 10-26-keV electrons are obtained on a crossed-beam apparatus in our laboratory. An ejected electron-produced ion-coincidence technique is employed together with a time-of-flight mass spectrometer for analysis of the ions. The six ionic fragments, CO{sub 2}{sup +}, CO{sup +}, CO{sub 2}{sup 2+}, O{sup +}, C{sup +}, and C{sup 2+}, resulting from dissociative ionization of the CO{sub 2} molecule are observed and identified; their relative ionization cross sections and branching ratios are determined as a function of impact energy. The binary-encounter Bethe model is found to overestimate the experimental data for total-ionization cross sections of the observed ions. No other experimental or theoretical data exist in the investigated energy range to make a direct comparison with the present results.

  3. Cross-field diffusion of energetic (100 keV to 2 MeV) protons in interplanetary space

    SciTech Connect

    Costa Jr, Edio da; Tsurutani, Bruce T.; Alves, Maria Virgínia; Echer, Ezequiel; Lakhina, Gurbax S. E-mail: costajr.e@gmail.com

    2013-12-01

    Magnetic field magnitude decreases (MDs) are observed in several regions of the interplanetary medium. In this paper, we characterize MDs observed by the Ulysses spacecraft instrumentation over the solar south pole by using magnetic field data to obtain the empirical size, magnetic field MD, and frequency of occurrence distribution functions. The interaction of energetic (100 keV to 2 MeV) protons with these MDs is investigated. Charged particle and MD interactions can be described by a geometrical model allowing the calculation of the guiding center shift after each interaction. Using the distribution functions for the MD characteristics, Monte Carlo simulations are used to obtain the cross-field diffusion coefficients as a function of particle kinetic energy. It is found that the protons under consideration cross-field diffuse at a rate of up to ≈11% of the Bohm rate. The same method used in this paper can be applied to other space regions where MDs are observed, once their local features are well known.

  4. WMS Server 2.0

    NASA Technical Reports Server (NTRS)

    Plesea, Lucian; Wood, James F.

    2012-01-01

    This software is a simple, yet flexible server of raster map products, compliant with the Open Geospatial Consortium (OGC) Web Map Service (WMS) 1.1.1 protocol. The server is a full implementation of the OGC WMS 1.1.1 as a fastCGI client and using Geospatial Data Abstraction Library (GDAL) for data access. The server can operate in a proxy mode, where all or part of the WMS requests are done on a back server. The server has explicit support for a colocated tiled WMS, including rapid response of black (no-data) requests. It generates JPEG and PNG images, including 16-bit PNG. The GDAL back-end support allows great flexibility on the data access. The server is a port to a Linux/GDAL platform from the original IRIX/IL platform. It is simpler to configure and use, and depending on the storage format used, it has better performance than other available implementations. The WMS server 2.0 is a high-performance WMS implementation due to the fastCGI architecture. The use of GDAL data back end allows for great flexibility. The configuration is relatively simple, based on a single XML file. It provides scaling and cropping, as well as blending of multiple layers based on layer transparency.

  5. Introducing ADS 2.0

    NASA Astrophysics Data System (ADS)

    Accomazzi, Alberto; Kurtz, M. J.; Henneken, E. A.; Grant, C. S.; Thompson, D.; Luker, J.; Chyla, R.; Murray, S. S.

    2014-01-01

    In the spring of 1993, the Smithsonian/NASA Astrophysics Data System (ADS) first launched its bibliographic search system. It was known then as the ADS Abstract Service, a component of the larger Astrophysics Data System effort which had developed an interoperable data system now seen as a precursor of the Virtual Observatory. As a result of the massive technological and sociological changes in the field of scholarly communication, the ADS is now completing the most ambitious technological upgrade in its twenty-year history. Code-named ADS 2.0, the new system features: an IT platform built on web and digital library standards; a new, extensible, industrial strength search engine; a public API with various access control capabilities; a set of applications supporting search, export, visualization, analysis; a collaborative, open source development model; and enhanced indexing of content which includes the full-text of astronomy and physics publications. The changes in the ADS platform affect all aspects of the system and its operations, including: the process through which data and metadata are harvested, curated and indexed; the interface and paradigm used for searching the database; and the follow-up analysis capabilities available to the users. This poster describes the choices behind the technical overhaul of the system, the technology stack used, and the opportunities which the upgrade is providing us with, namely gains in productivity and enhancements in our system capabilities.

  6. Teaching Web 2.0 technologies using Web 2.0 technologies

    PubMed Central

    Piorun, Mary; Prince, J. Dale

    2009-01-01

    Objectives: The research evaluated participant satisfaction with the content and format of the “Web 2.0 101: Introduction to Second Generation Web Tools” course and measured the impact of the course on participants' self-evaluated knowledge of Web 2.0 tools. Methods: The “Web 2.0 101” online course was based loosely on the Learning 2.0 model. Content was provided through a course blog and covered a wide range of Web 2.0 tools. All Medical Library Association members were invited to participate. Participants were asked to complete a post-course survey. Respondents who completed the entire course or who completed part of the course self-evaluated their knowledge of nine social software tools and concepts prior to and after the course using a Likert scale. Additional qualitative information about course strengths and weaknesses was also gathered. Results: Respondents' self-ratings showed a significant change in perceived knowledge for each tool, using a matched pair Wilcoxon signed rank analysis (P<0.0001 for each tool/concept). Overall satisfaction with the course appeared high. Hands-on exercises were the most frequently identified strength of the course; the length and time-consuming nature of the course were considered weaknesses by some. Conclusion: Learning 2.0-style courses, though demanding time and self-motivation from participants, can increase knowledge of Web 2.0 tools. PMID:19851488

  7. The PLATO 2.0 mission

    NASA Astrophysics Data System (ADS)

    Rauer, H.; Catala, C.; Aerts, C.; Appourchaux, T.; Benz, W.; Brandeker, A.; Christensen-Dalsgaard, J.; Deleuil, M.; Gizon, L.; Goupil, M.-J.; Güdel, M.; Janot-Pacheco, E.; Mas-Hesse, M.; Pagano, I.; Piotto, G.; Pollacco, D.; Santos, Ċ.; Smith, A.; Suárez, J.-C.; Szabó, R.; Udry, S.; Adibekyan, V.; Alibert, Y.; Almenara, J.-M.; Amaro-Seoane, P.; Eiff, M. Ammler-von; Asplund, M.; Antonello, E.; Barnes, S.; Baudin, F.; Belkacem, K.; Bergemann, M.; Bihain, G.; Birch, A. C.; Bonfils, X.; Boisse, I.; Bonomo, A. S.; Borsa, F.; Brandão, I. M.; Brocato, E.; Brun, S.; Burleigh, M.; Burston, R.; Cabrera, J.; Cassisi, S.; Chaplin, W.; Charpinet, S.; Chiappini, C.; Church, R. P.; Csizmadia, Sz.; Cunha, M.; Damasso, M.; Davies, M. B.; Deeg, H. J.; Díaz, R. F.; Dreizler, S.; Dreyer, C.; Eggenberger, P.; Ehrenreich, D.; Eigmüller, P.; Erikson, A.; Farmer, R.; Feltzing, S.; de Oliveira Fialho, F.; Figueira, P.; Forveille, T.; Fridlund, M.; García, R. A.; Giommi, P.; Giuffrida, G.; Godolt, M.; Gomes da Silva, J.; Granzer, T.; Grenfell, J. L.; Grotsch-Noels, A.; Günther, E.; Haswell, C. A.; Hatzes, A. P.; Hébrard, G.; Hekker, S.; Helled, R.; Heng, K.; Jenkins, J. M.; Johansen, A.; Khodachenko, M. L.; Kislyakova, K. G.; Kley, W.; Kolb, U.; Krivova, N.; Kupka, F.; Lammer, H.; Lanza, A. F.; Lebreton, Y.; Magrin, D.; Marcos-Arenal, P.; Marrese, P. M.; Marques, J. P.; Martins, J.; Mathis, S.; Mathur, S.; Messina, S.; Miglio, A.; Montalban, J.; Montalto, M.; Monteiro, M. J. P. F. G.; Moradi, H.; Moravveji, E.; Mordasini, C.; Morel, T.; Mortier, A.; Nascimbeni, V.; Nelson, R. P.; Nielsen, M. B.; Noack, L.; Norton, A. J.; Ofir, A.; Oshagh, M.; Ouazzani, R.-M.; Pápics, P.; Parro, V. C.; Petit, P.; Plez, B.; Poretti, E.; Quirrenbach, A.; Ragazzoni, R.; Raimondo, G.; Rainer, M.; Reese, D. R.; Redmer, R.; Reffert, S.; Rojas-Ayala, B.; Roxburgh, I. W.; Salmon, S.; Santerne, A.; Schneider, J.; Schou, J.; Schuh, S.; Schunker, H.; Silva-Valio, A.; Silvotti, R.; Skillen, I.; Snellen, I.; Sohl, F.; Sousa, S. G.; Sozzetti, A.; Stello, D.; Strassmeier, K. G.; Švanda, M.; Szabó, Gy. M.; Tkachenko, A.; Valencia, D.; Van Grootel, V.; Vauclair, S. D.; Ventura, P.; Wagner, F. W.; Walton, N. A.; Weingrill, J.; Werner, S. C.; Wheatley, P. J.; Zwintz, K.

    2014-11-01

    PLATO 2.0 has recently been selected for ESA's M3 launch opportunity (2022/24). Providing accurate key planet parameters (radius, mass, density and age) in statistical numbers, it addresses fundamental questions such as: How do planetary systems form and evolve? Are there other systems with planets like ours, including potentially habitable planets? The PLATO 2.0 instrument consists of 34 small aperture telescopes (32 with 25 s readout cadence and 2 with 2.5 s candence) providing a wide field-of-view (2232 deg 2) and a large photometric magnitude range (4-16 mag). It focusses on bright (4-11 mag) stars in wide fields to detect and characterize planets down to Earth-size by photometric transits, whose masses can then be determined by ground-based radial-velocity follow-up measurements. Asteroseismology will be performed for these bright stars to obtain highly accurate stellar parameters, including masses and ages. The combination of bright targets and asteroseismology results in high accuracy for the bulk planet parameters: 2 %, 4-10 % and 10 % for planet radii, masses and ages, respectively. The planned baseline observing strategy includes two long pointings (2-3 years) to detect and bulk characterize planets reaching into the habitable zone (HZ) of solar-like stars and an additional step-and-stare phase to cover in total about 50 % of the sky. PLATO 2.0 will observe up to 1,000,000 stars and detect and characterize hundreds of small planets, and thousands of planets in the Neptune to gas giant regime out to the HZ. It will therefore provide the first large-scale catalogue of bulk characterized planets with accurate radii, masses, mean densities and ages. This catalogue will include terrestrial planets at intermediate orbital distances, where surface temperatures are moderate. Coverage of this parameter range with statistical numbers of bulk characterized planets is unique to PLATO 2.0. The PLATO 2.0 catalogue allows us to e.g.: - complete our knowledge of planet

  8. Experimental determination of the real elements of the density matrix of H({ital n}=3) atoms produced in 20--100-keV collisions of H{sup +} on Kr

    SciTech Connect

    Seifert, N.; Gibson, N.D.; Risley, J.S.

    1995-11-01

    In continuation of our previous work, charge transfer processes occurring in protons on rare-gas-atom collisions have been investigated. Diagonal and real off-diagonal coherence elements of the density matrix for H({ital n}=3) atoms produced in 20--100-keV electron-capture collisions with Kr atoms are experimentally determined by analyzing the Balmer-{alpha} light from the decay of H atoms from the ({ital n}=3) state to the ({ital n}=2) state. The intensity and polarization of the emitted light are measured as functions of an axially symmetric electric field in the collision region. These data are fitted to a numerical model of the H atom in an electric field in order to extract density-matrix elements. The results are compared to previous studies of H{sup +} on He and Ar. The collisionally produced dipole moment of the H({ital n}=3) atom decreases for increasing atomic number of the rare-gas target atoms, which indicates that the final phase of the collision process is not essential for the formation of the dipole moment. This physical picture is further supported by our alignment data. Absolute cross sections for charge transfer to the 3{ital s}, 3{ital p}, and 3{ital d} levels are presented as well.

  9. Experimental determination of real elements of the density matrix and the dipole moment of H([ital n]=3) atoms produced from 20--100-keV H[sup +] on Ar

    SciTech Connect

    Renwick, S.P.; Martell, E.C.; Weaver, W.D.; Risley, J.S. )

    1993-10-01

    Diagonal and real off-diagonal coherence elements of the density matrix for H([ital n]=3) atoms produced in 20--100-keV electron-capture collisions of protons with Ar atoms are experimentally determined. Balmer-[alpha] light from the decay of H atoms from the ([ital n]=3) state to the ([ital n]=2) state is observed. The intensity and polarization of the light as a function of an axially symmetric electric field in the collision region are fitted to a numerical model of the H atom in an electric field in order to extract density-matrix elements. A new polarimeter, using a photoelastic modulator in conjunction with photon-counting techniques, is used in the experiment, and its efficacy is analyzed and compared to that of a rotating quarter-wave plate polarimeter previously used in similar experiments. The diagonal elements of the density matrix yield relative capture cross sections for the H(3[ital l]) angular-momentum substates, while the coherence terms are used to determine the dipole moment of the atoms produced. Results are compared to those for protons colliding with a He target and the differences are discussed.

  10. Validation Results for LEWICE 2.0

    NASA Technical Reports Server (NTRS)

    Wright, William B.; Rutkowski, Adam

    1999-01-01

    A research project is underway at NASA Lewis to produce a computer code which can accurately predict ice growth under any meteorological conditions for any aircraft surface. This report will present results from version 2.0 of this code, which is called LEWICE. This version differs from previous releases due to its robustness and its ability to reproduce results accurately for different spacing and time step criteria across computing platform. It also differs in the extensive amount of effort undertaken to compare the results in a quantified manner against the database of ice shapes which have been generated in the NASA Lewis Icing Research Tunnel (IRT). The results of the shape comparisons are analyzed to determine the range of meteorological conditions under which LEWICE 2.0 is within the experimental repeatability. This comparison shows that the average variation of LEWICE 2.0 from the experimental data is 7.2% while the overall variability of the experimental data is 2.5%.

  11. Interferometric phase-contrast X-ray CT imaging of VX2 rabbit cancer at 35keV X-ray energy

    SciTech Connect

    Takeda, Tohoru; Wu Jin; Tsuchiya, Yoshinori; Lwin, Thet-Thet; Itai, Yuji; Yoneyama, Akio; Hyodo, Kazuyuki

    2004-05-12

    Imaging of large objects at 17.7-keV low x-ray energy causes huge x-ray exposure to the objects even using interferometric phase-contrast x-ray CT (PCCT). Thus, we tried to obtain PCCT images at high x-ray energy of 35keV and examined the image quality using a formalin-fixed VX2 rabbit cancer specimen with 15-mm in diameter. The PCCT system consisted of an asymmetrically cut silicon (220) crystal, a monolithic x-ray interferometer, a phase-shifter, an object cell and an x-ray CCD camera. The PCCT at 35 keV clearly visualized various inner structures of VX2 rabbit cancer such as necrosis, cancer, the surrounding tumor vessels, and normal liver tissue. Besides, image-contrast was not degraded significantly. These results suggest that the PCCT at 35 KeV is sufficient to clearly depict the histopathological morphology of VX2 rabbit cancer specimen.

  12. The determination of interplanetary magnetic field polarities around sector boundaries using E greater than 2 keV electrons

    NASA Technical Reports Server (NTRS)

    Kahler, S.; Lin, R. P.

    1994-01-01

    The determination of the polarities of interplanetary magnetic fields (whether the field direction is outward from or inward toward the sun) has been based on a comparison of observed field directions with the nominal Parker spiral angle. These polarities can be mapped back to the solar source field polarities. This technique fails when field directions deviate substantially from the Parker angle or when fields are substantially kinked. We introduce a simple new technique to determine the polarities of interplanetary fields using E greater than 2 keV interplanetary electrons which stream along field lines away from the sun. Those electrons usually show distinct unidirectional pitch-angle anisotropies either parallel or anti-parallel to the field. Since the electron flow direction is known to be outward from the sun, the anisotropies parallel to the field indicate outward-pointing, positive-polarity fields, and those anti-parallel indicate inward-pointing, negative-polarity fields. We use data from the UC Berkeley electron experiment on the International Sun Earth Explorer 3 (ISSE-3) spacecraft to compare the field polarities deduced from the electron data, Pe (outward or inward), with the polarities inferred from field directions, Pd, around two sector boundaries in 1979. We show examples of large (greater than 100 deg) changes in azimuthal field direction Phi over short (less than 1 hr) time scales, some with and some without reversals in Pe. The latter cases indicate that such large directional changes can occur in unipolar structures. On the other hand, we found an example of a change in Pe during which the rotation in Phi was less than 30 deg, indicating polarity changes in nearly unidirectional structures. The field directions are poor guides to the polarities in these cases.

  13. Web 2.0 Applications in China

    NASA Astrophysics Data System (ADS)

    Zhai, Dongsheng; Liu, Chen

    Since 2005, the term Web 2.0 has gradually become a hot topic on the Internet. Web 2.0 lets users create web contents as distinct from webmasters or web coders. Web 2.0 has come to our work, our life and even has become an indispensable part of our web-life. Its applications have already been widespread in many fields on the Internet. So far, China has about 137 million netizens [1], therefore its Web 2.0 market is so attractive that many sources of venture capital flow into the Chinese Web 2.0 market and there are also a lot of new Web 2.0 companies in China. However, the development of Web 2.0 in China is accompanied by some problems and obstacles. In this paper, we will mainly discuss Web 2.0 applications in China, with their current problems and future development trends.

  14. The temperature effect on the glycine decomposition induced by 2 keV electron bombardment in space analog conditions

    NASA Astrophysics Data System (ADS)

    Pilling, Sergio; Nair, Binu G.; Escobar, Antonio; Fraser, Helen; Mason, Nigel

    2014-03-01

    Glycine is the simplest proteinaceous amino acid that has been extensively detected in carbonaceous meteorites and was recently observed in the cometary samples returned to Earth by NASA's Stardust spacecraft. In space, such species is exposed to several radiation fields at different temperatures. In aqueous solutions, this species appears mainly as zwitterionic glycine (+NH3CH2COO-) however, in solid phase, it may be found in amorphous or crystalline forms. Here, we present an experimental study on the destruction of two zwitterionic glycine crystals ( α- and β-form) at two different temperatures (300 K and 14 K) by 2 keV electrons in an attempt to test the behavior and stability of this molecular species in different space environments. The samples were analyzed in situ by Fourier transform infrared spectrometry at electron fluences. The experiments were carried out under ultra-high vacuum conditions at the Molecular Physics Laboratory at the Open University at Milton Keynes, UK. The dissociation cross section of glycine is approximately 5 times higher for the 14 K samples when compared to the 300 K samples. In contrast, no significant differences emerged between the dissociation cross sections of α- and β-forms of glycine for fixed temperature experiments. We therefore conclude that the destruction cross section is more heavily dependent on temperature than the phase of the condensed glycine material. This may be associated with the opening of additional reaction routes in the frozen samples involving the trapped daughter species (e.g. CO2 and CO). The half-life of studied samples extrapolated to space conditions shows that glycine molecules on the surface of interstellar grains has less survivability and they are highly sensitive to ambient radiations, however, they can survive extended period of time in the solar system like environments. Survivability increases by a factor of 5 if the samples are at 300 K when compared to low temperature experiments at 14

  15. Using Web 2.0 to Collaborate

    ERIC Educational Resources Information Center

    Buechler, Scott

    2010-01-01

    Web 2.0 is not only for kids anymore, businesses are using it, too. Businesses are adopting Web 2.0 technology for a variety of purposes. In this article, the author discusses how he incorporates Web 2.0 into his business communications course. He describes a project that has both individual and collaborative elements and requires extensive…

  16. 22 CFR 20.2 - Funding.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Funding. 20.2 Section 20.2 Foreign Relations DEPARTMENT OF STATE PERSONNEL BENEFITS FOR CERTAIN FORMER SPOUSES § 20.2 Funding. Benefits under this part are paid from the Fund maintained by the Secretary of the Treasury pursuant to section 802 of the...

  17. 22 CFR 20.2 - Funding.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Funding. 20.2 Section 20.2 Foreign Relations DEPARTMENT OF STATE PERSONNEL BENEFITS FOR CERTAIN FORMER SPOUSES § 20.2 Funding. Benefits under this part are paid from the Fund maintained by the Secretary of the Treasury pursuant to section 802 of the...

  18. 22 CFR 20.2 - Funding.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Funding. 20.2 Section 20.2 Foreign Relations DEPARTMENT OF STATE PERSONNEL BENEFITS FOR CERTAIN FORMER SPOUSES § 20.2 Funding. Benefits under this part are paid from the Fund maintained by the Secretary of the Treasury pursuant to section 802 of the...

  19. 22 CFR 20.2 - Funding.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Funding. 20.2 Section 20.2 Foreign Relations DEPARTMENT OF STATE PERSONNEL BENEFITS FOR CERTAIN FORMER SPOUSES § 20.2 Funding. Benefits under this part are paid from the Fund maintained by the Secretary of the Treasury pursuant to section 802 of the...

  20. 22 CFR 20.2 - Funding.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Funding. 20.2 Section 20.2 Foreign Relations DEPARTMENT OF STATE PERSONNEL BENEFITS FOR CERTAIN FORMER SPOUSES § 20.2 Funding. Benefits under this part are paid from the Fund maintained by the Secretary of the Treasury pursuant to section 802 of the...

  1. 28 CFR 20.2 - Authority.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 1 2013-07-01 2013-07-01 false Authority. 20.2 Section 20.2 Judicial Administration DEPARTMENT OF JUSTICE CRIMINAL JUSTICE INFORMATION SYSTEMS General Provisions § 20.2 Authority. These regulations are issued pursuant to sections 501 and 524(b) of the Omnibus Crime Control and...

  2. 28 CFR 20.2 - Authority.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Authority. 20.2 Section 20.2 Judicial Administration DEPARTMENT OF JUSTICE CRIMINAL JUSTICE INFORMATION SYSTEMS General Provisions § 20.2 Authority. These regulations are issued pursuant to sections 501 and 524(b) of the Omnibus Crime Control and...

  3. 28 CFR 20.2 - Authority.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 1 2011-07-01 2011-07-01 false Authority. 20.2 Section 20.2 Judicial Administration DEPARTMENT OF JUSTICE CRIMINAL JUSTICE INFORMATION SYSTEMS General Provisions § 20.2 Authority. These regulations are issued pursuant to sections 501 and 524(b) of the Omnibus Crime Control and...

  4. 28 CFR 20.2 - Authority.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 1 2014-07-01 2014-07-01 false Authority. 20.2 Section 20.2 Judicial Administration DEPARTMENT OF JUSTICE CRIMINAL JUSTICE INFORMATION SYSTEMS General Provisions § 20.2 Authority. These regulations are issued pursuant to sections 501 and 524(b) of the Omnibus Crime Control and...

  5. 28 CFR 20.2 - Authority.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 1 2012-07-01 2012-07-01 false Authority. 20.2 Section 20.2 Judicial Administration DEPARTMENT OF JUSTICE CRIMINAL JUSTICE INFORMATION SYSTEMS General Provisions § 20.2 Authority. These regulations are issued pursuant to sections 501 and 524(b) of the Omnibus Crime Control and...

  6. 30 CFR 20.2 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Definitions. 20.2 Section 20.2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MINE LAMPS OTHER THAN STANDARD CAP LAMPS § 20.2 Definitions. (a) Adequate. Appropriate and sufficient as determined by...

  7. 30 CFR 20.2 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Definitions. 20.2 Section 20.2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MINE LAMPS OTHER THAN STANDARD CAP LAMPS § 20.2 Definitions. (a) Adequate. Appropriate and sufficient as determined by...

  8. 30 CFR 20.2 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Definitions. 20.2 Section 20.2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MINE LAMPS OTHER THAN STANDARD CAP LAMPS § 20.2 Definitions. (a) Adequate. Appropriate and sufficient as determined by...

  9. 30 CFR 20.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Definitions. 20.2 Section 20.2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MINE LAMPS OTHER THAN STANDARD CAP LAMPS § 20.2 Definitions. (a) Adequate. Appropriate and sufficient as determined by...

  10. 36 CFR 20.2 - Permits; conditions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Permits; conditions. 20.2 Section 20.2 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR ISLE ROYALE NATIONAL PARK; COMMERCIAL FISHING § 20.2 Permits; conditions. Annual, revocable special...

  11. 36 CFR 20.2 - Permits; conditions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Permits; conditions. 20.2 Section 20.2 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR ISLE ROYALE NATIONAL PARK; COMMERCIAL FISHING § 20.2 Permits; conditions. Annual, revocable special...

  12. Understanding FCAT 2.0 Reports

    ERIC Educational Resources Information Center

    Florida Department of Education, 2011

    2011-01-01

    The Florida Department of Education (FDOE) is transitioning from the Florida Comprehensive Assessment Test (FCAT) to the Florida Comprehensive Assessment Test® 2.0 (FCAT 2.0) to align with new student academic content standards. This booklet has been prepared to help understand the reports for the FCAT 2.0. It includes explanations of the reports,…

  13. 7 CFR 20.2 - Administration.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 1 2013-01-01 2013-01-01 false Administration. 20.2 Section 20.2 Agriculture Office of the Secretary of Agriculture EXPORT SALES REPORTING REQUIREMENTS § 20.2 Administration. The regulations of this part will be administered by the Foreign Agricultural Service (FAS) under the...

  14. 7 CFR 20.2 - Administration.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Administration. 20.2 Section 20.2 Agriculture Office of the Secretary of Agriculture EXPORT SALES REPORTING REQUIREMENTS § 20.2 Administration. The regulations of this part will be administered by the Foreign Agricultural Service (FAS) under the...

  15. 7 CFR 20.2 - Administration.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 1 2012-01-01 2012-01-01 false Administration. 20.2 Section 20.2 Agriculture Office of the Secretary of Agriculture EXPORT SALES REPORTING REQUIREMENTS § 20.2 Administration. The regulations of this part will be administered by the Foreign Agricultural Service (FAS) under the...

  16. 30 CFR 20.2 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Definitions. 20.2 Section 20.2 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MINE LAMPS OTHER THAN STANDARD CAP LAMPS § 20.2 Definitions. (a) Adequate. Appropriate and sufficient as determined by...

  17. What dominates the X-ray emission of Andromeda at E>20 keV? New constraints from NuSTAR and Swift on a very bright, hard X-ray source

    NASA Astrophysics Data System (ADS)

    Yukita, Mihoko; Ptak, Andrew; Maccarone, Thomas J.; Hornschemeier, Ann E.; Wik, Daniel R.; Pottschmidt, Katja; Antoniou, Vallia; Baganoff, Frederick K.; Lehmer, Bret; Zezas, Andreas; Boyd, Patricia T.; Kennea, Jamie; Page, Kim L.

    2016-04-01

    Thanks to its better sensitivity and spatial resolution, NuSTAR allows us to investigate the E>10 keV properties of nearby galaxies. We now know that starburst galaxies, containing very young stellar populations, have X-ray spectra which drop quickly above 10 keV. We extend our investigation of hard X-ray properties to an older stellar population system, the bulge of M31. The NuSTAR and Swift simultaneous observations reveal a bright hard source dominating the M31 bulge above 20 keV, which is likely to be a counterpart of Swift J0042.6+4112 previously detected (but not classified) in the Swift BAT All-sky Hard X-ray Survey. This source had been classified as an XRB candidate in various Chandra and XMM-Newton studies; however, since it was not clear that it is the counterpart to the strong Swift J0042.6+4112 source at higher energies, the previous E < 10 keV observations did not generate much attention. The NuSTAR and Swift spectra of this source drop quickly at harder energies as observed in sources in starburst galaxies. The X-ray spectral properties of this source are very similar to those of an accreting pulsar; yet, we do not find a pulsation in the NuSTAR data. The existing deep HST images indicate no high mass donors at the location of this source, further suggesting that this source has an intermediate or low mass companion. The most likely scenario for the nature of this source is an X-ray pulsar with an intermediate/low mass companion similar to the Galactic Her X-1 system. We will also discuss other possibilities in more detail.

  18. The 2-10 keV unabsorbed luminosity function of AGN from the LSS, CDFS, and COSMOS surveys

    NASA Astrophysics Data System (ADS)

    Ranalli, P.; Koulouridis, E.; Georgantopoulos, I.; Fotopoulou, S.; Hsu, L.-T.; Salvato, M.; Comastri, A.; Pierre, M.; Cappelluti, N.; Carrera, F. J.; Chiappetti, L.; Clerc, N.; Gilli, R.; Iwasawa, K.; Pacaud, F.; Paltani, S.; Plionis, E.; Vignali, C.

    2016-05-01

    The XMM-Large scale structure (XMM-LSS), XMM-Cosmological evolution survey (XMM-COSMOS), and XMM-Chandra deep field south (XMM-CDFS) surveys are complementary in terms of sky coverage and depth. Together, they form a clean sample with the least possible variance in instrument effective areas and point spread function. Therefore this is one of the best samples available to determine the 2-10 keV luminosity function of active galactic nuclei (AGN) and their evolution. The samples and the relevant corrections for incompleteness are described. A total of 2887 AGN is used to build the LF in the luminosity interval 1042-1046 erg s-1 and in the redshift interval 0.001-4. A new method to correct for absorption by considering the probability distribution for the column density conditioned on the hardness ratio is presented. The binned luminosity function and its evolution is determined with a variant of the Page-Carrera method, which is improved to include corrections for absorption and to account for the full probability distribution of photometric redshifts. Parametric models, namely a double power law with luminosity and density evolution (LADE) or luminosity-dependent density evolution (LDDE), are explored using Bayesian inference. We introduce the Watanabe-Akaike information criterion (WAIC) to compare the models and estimate their predictive power. Our data are best described by the LADE model, as hinted by the WAIC indicator. We also explore the recently proposed 15-parameter extended LDDE model and find that this extension is not supported by our data. The strength of our method is that it provides unabsorbed, non-parametric estimates, credible intervals for luminosity function parameters, and a model choice based on predictive power for future data. Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA member states and NASA.Tables with the samples of the posterior probability distributions

  19. Schwinger variational approach for a direct excitation of hydrogen-like (Li2+ (1s)) target to the level n=3 by proton impact energies from 9 keV to 3 MeV

    NASA Astrophysics Data System (ADS)

    Khelfaoui, Friha; Lasri, Boumediene; Abbes, Oukacha

    2012-06-01

    The excitation cross sections for hydrogen-like (Li2+(1s)) to the 3s, 3p and 3d states by proton impact have been calculated in a wide energy range from 9 keV to 3 MeV, using the Schwinger's variational principle within the impact parameter formalism. These cross sections are relevant to controlled nuclear fusion studies [1]. The behaviors of the computed cross sections are in excellent agreement with available theoretical results, obtained by close-coupling method which is those of TCAO of Ermolaev et al [1] and SCE of Hall et al [2].

  20. SPUTTERING AND MOLECULAR SYNTHESIS INDUCED BY 100 keV PROTONS IN CONDENSED CO{sub 2} AND RELEVANCE TO THE OUTER SOLAR SYSTEM

    SciTech Connect

    Raut, U.; Baragiola, R. A.

    2013-07-20

    We present results on sputtering and radiation chemistry of CO{sub 2} films induced by 100 keV H{sup +} at 25 and 50 K. Using a quartz crystal microbalance, we measure a sputtering yield (SY) between {approx}10 and 20 CO{sub 2} equivalent per ion at 25 K. The yield at 50 K is similar to that at 25 K at low fluences, but increases to {approx}2400 by mid-10{sup 14} H{sup +} cm{sup -2} and declines at higher fluence. Irradiation to 1 Multiplication-Sign 10{sup 15} H{sup +} cm{sup -2} depletes {approx}85%-90% of the initial film mass at 50 K, compared to 3% at 25 K. In both cases, mass spectrometry shows that CO is the dominant constituent in the sputtered flux, followed by O{sub 2}, O, and CO{sub 2}. Using infrared spectroscopy, we monitor the depletion of CO{sub 2} and the accumulation of CO and O{sub 2} and minor species as O{sub 3} and CO{sub 3}. We determine G(-CO{sub 2}) = 2.6 {+-} 0.3, the number of CO{sub 2} destroyed per 100 eV at 25 K. A significant fraction of the radiolyzed CO and O{sub 2} are retained in the film at 25 K; only those near the surface are removed during irradiation, contributing to a smaller SY. At 50 K, CO and O{sub 2} are unstable along the 'hot' ion track and are expelled possibly from the entire depth of the film. Our results, and the lack of detection of CO in the exospheres around Rhea and Dione, show that the CO{sub 2} does not originate from sputtering, since otherwise the exosphere would be dominated by CO, the main molecule in the sputtered flux. We suggest that the exospheric CO{sub 2} is thermally released from an endogenic source.

  1. Is 20/20 vision good enough? Visual acuity differences within the normal range predict contour element detection and integration

    PubMed Central

    Keane, Brian P.; Kastner, Sabine; Paterno, Danielle; Silverstein, Steven M.

    2014-01-01

    Contour integration (CI) combines appropriately aligned and oriented elements into continuous boundaries. Collinear facilitation (CF) occurs when a low-contrast oriented element becomes more visible when flanked by collinear high-contrast elements. Both processes rely at least partly on long-range horizontal connections in early visual cortex, and thus both have been extensively studied to understand visual cortical functioning in aging, development, and clinical disorders. Here, we ask: Can acuity differences within the normal range predict CI or CF? To consider this question, we measured binocular visual acuity and compared subjects with 20/20 vision to those with better-than-20/20 vision (SharpPerceivers) on two tasks. In the CI task, subjects located an integrated shape embedded in varying amounts of noise; in the CF task, subjects detected a low-contrast element flanked by collinear or orthogonal high-contrast elements. In each case, displays were scaled in size to modulate element visibility and spatial frequency (4-12 cycles/deg). SharpPerceivers could integrate contours under noisier conditions than the 20/20 group (p=.0002) especially for high spatial frequency displays. Moreover, although the two groups exhibited similar collinear facilitation, SharpPerceivers could detect the central target with lower contrast at high spatial frequencies (p<.05). These results suggest that small acuity differences within the normal range—corresponding to about a one line difference on a vision chart—strongly predict element detection and integration. Furthermore, simply ensuring that subjects have normal or corrected-to-normal vision is not sufficient when comparing groups on contour tasks; visual acuity confounds also need to be ruled out. PMID:24845876

  2. Theoretical electron impact elastic, ionization and total cross sections for silicon hydrides, SiHx (x = 1, 2, 3, 4) and disilane, Si2H6 from threshold to 5 keV

    NASA Astrophysics Data System (ADS)

    Vinodkumar, M.; Limbachiya, C.; Korot, K.; Joshipura, K. N.

    2008-07-01

    In this article we report comprehensive calculations of total elastic (Qel), and total ionization cross sections, (Qion), on silicon hydrides SiHx (x = 1 4) and disilane, Si2H6 on electron impact at energies from circa threshold to 2000 eV and total (complete) cross sections (QT) up to 5 keV. Spherical complex optical potential (SCOP) formalism is employed to evaluate Qel and QT. Total ionization cross sections, Qion, are derived from total inelastic cross sections, Qinel, using our complex spherical potential ionization contribution (CSP-ic) method. Dependence of QT on the dipole polarizability of the target and incident energy is presented for these targets through analytical formula, using which calculation of QT is extended up to 5 keV. Comparison of QT for all these targets is carried out to present a general theoretical picture of collision processes and also to visualize the dependence of QT on the total number of electrons in the target and hence on the geometrical size of the target. Present calculations also provide information on the excitation processes of these targets. Present results are compared with available experimental and other theoretical data wherever available and overall good agreement is observed. There is probably no data for total elastic and total (complete) cross sections for SiHx (x = 2-3) in the present energy range and hence reported for the first time.

  3. FRAMES-2.0 Software System: Frames 2.0 Pest Integration (F2PEST)

    SciTech Connect

    Castleton, Karl J.; Meyer, Philip D.

    2009-06-17

    The implementation of the FRAMES 2.0 F2PEST module is described, including requirements, design, and specifications of the software. This module integrates the PEST parameter estimation software within the FRAMES 2.0 environmental modeling framework. A test case is presented.

  4. Compact range test applications, phase 2

    NASA Astrophysics Data System (ADS)

    Davis, Francis L.

    1992-01-01

    Georgia Tech Research Institute (GTRI) has designed and fabricated a large outdoor Compact Antenna Range for the U.S. Army Electronic Proving Ground (USAEPG). This range enables USAEPG to test antenna systems of large ground vehicles or aircraft that weigh up to 70 tons and are up to 50 feet in size over a frequency range of 6 to 40 GHz. Ongoing investigation and study are being conducted to determine the compatibility and adaptability of this antenna pattern measurement range to measure other system parameters such as target return signals and system responses to specialized electromagnetic environments.

  5. 2 CFR 225.20 - Policy.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Policy. 225.20 Section 225.20 Grants and Agreements OFFICE OF MANAGEMENT AND BUDGET CIRCULARS AND GUIDANCE Reserved COST PRINCIPLES FOR STATE, LOCAL, AND INDIAN TRIBAL GOVERNMENTS (OMB CIRCULAR A-87) § 225.20 Policy. This part establishes...

  6. 2 CFR 200.20 - Computing devices.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 2 Grants and Agreements 1 2014-01-01 2014-01-01 false Computing devices. 200.20 Section 200.20 Grants and Agreements Office of Management and Budget Guidance for Grants and Agreements OFFICE OF... REQUIREMENTS FOR FEDERAL AWARDS Acronyms and Definitions Acronyms § 200.20 Computing devices. Computing...

  7. Experiments: Test range facilities, part 2

    NASA Astrophysics Data System (ADS)

    Dudley, D. G.

    1987-06-01

    A description is given of the electromagnetic transient range facility at the Lawrence Livermore Laboratory. The range design and the instrumentation for both time domain and broadband frequency domain measurements are discussed. Two examples of experiments are given: scattering from a conducting plate and transmission through an aperture in a screen.

  8. The low energy particle detector sled (~30 keV-3.2 MeV) and its performance on the phobos mission to mars and its moons

    NASA Astrophysics Data System (ADS)

    McKenna-Lawlor, S.; Afonin, V. V.; Gringauz, K. I.; Keppler, E.; Kirsch, E.; Richter, A.; Witte, M.; O'Sullivan, D.; Thompson, A.; Somogyi, A. J.; Szabo, L.; Varga, A.

    1990-05-01

    A low energy particle detector system (SLED) is described which was designed to measure the flux densities of electrons and ions in the energy range from ~30 keV to a few MeV in (a) the varying solar aspect angles and temperatures pertaining during the Cruise Phase of the Phobos Mission and (b) in the low temperature environment (reaching -25° C) pertaining during Mars Encounter. Representative data illustrating the excellent functioning of SLED during both phases of the mission are presented.

  9. DISFRAC Version 2.0 Users Guide

    SciTech Connect

    Cochran, Kristine B; Erickson, Marjorie A; Williams, Paul T; Klasky, Hilda B; Bass, Bennett Richard

    2013-01-01

    DISFRAC is the implementation of a theoretical, multi-scale model for the prediction of fracture toughness in the ductile-to-brittle transition temperature (DBTT) region of ferritic steels. Empirically-derived models of the DBTT region cannot legitimately be extrapolated beyond the range of existing fracture toughness data. DISFRAC requires only tensile properties and microstructural information as input, and thus allows for a wider range of application than empirical, toughness data dependent models. DISFRAC is also a framework for investigating the roles of various microstructural and macroscopic effects on fracture behavior, including carbide particle sizes, grain sizes, strain rates, and material condition. DISFRAC s novel approach is to assess the interaction effects of macroscopic conditions (geometry, loading conditions) with variable microstructural features on cleavage crack initiation and propagation. The model addresses all stages of the fracture process, from microcrack initiation within a carbide particle, to propagation of that crack through grains and across grain boundaries, finally to catastrophic failure of the material. The DISFRAC procedure repeatedly performs a deterministic analysis of microcrack initiation and propagation within a macroscopic crack plastic zone to calculate a critical fracture toughness value for each microstructural geometry set. The current version of DISFRAC, version 2.0, is a research code for developing and testing models related to cleavage fracture and transition toughness. The various models and computations have evolved significantly over the course of development and are expected to continue to evolve as testing and data collection continue. This document serves as a guide to the usage and theoretical foundations of DISFRAC v2.0. Feedback is welcomed and encouraged.

  10. Mass attenuation coefficient of binderless, pre-treated and tannin-based Rhizophora spp. particleboards using 16.59 – 25.26 keV photon energy range

    SciTech Connect

    Mohd Yusof, Mohd Fahmi Hamid, Puteri Nor Khatijah Abdul; Tajuddin, Abdul Aziz; Bauk, Sabar; Hashim, Rokiah

    2015-04-29

    The Rhizophora spp. particleboards were fabricated using ≤ 104 µm particle size at three different fabrication methods; binderless, steam pre-treated and tannin-added. The mass attenuation coefficient of Rhizophora spp. particleboards were measured using x-ray fluorescent (XRF) photon from niobium, molybdenum, palladium, silver and tin metal plates that provided photon energy between 16.59 to 25.26 keV. The results were compared to theoretical values for water calculated using photon cross-section database (XCOM).The results showed that all Rhizophora spp. particleboards having mass attenuation coefficient close to calculated XCOM for water. Tannin-added Rizophora spp. particleboard was nearest to calculated XCOM for water with χ2 value of 13.008 followed by binderless Rizophora spp. (25.859) and pre-treated Rizophora spp. (91.941)

  11. Trust, Voice, and Library 2.0

    ERIC Educational Resources Information Center

    Watkins, Candice

    2009-01-01

    Web 2.0 is a constant and growing theme in the library field. This article describes a social networking site based on a Web 2.0 infused course management system (CMS) developed by Clatsop Community College in Astoria, Oregon.

  12. 36 CFR 20.2 - Permits; conditions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Section 20.2 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR ISLE ROYALE NATIONAL PARK; COMMERCIAL FISHING § 20.2 Permits; conditions. Annual, revocable special use... commercial fishing in the waters contiguous to the Park may be granted by the Director of the National...

  13. 36 CFR 20.2 - Permits; conditions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Section 20.2 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR ISLE ROYALE NATIONAL PARK; COMMERCIAL FISHING § 20.2 Permits; conditions. Annual, revocable special use... commercial fishing in the waters contiguous to the Park may be granted by the Director of the National...

  14. Student Inquiry and Web 2.0

    ERIC Educational Resources Information Center

    Berger, Pam

    2010-01-01

    Web 2.0 applications are changing how educators interact both with each other and with their students. Educators can use these new Web tools daily to create, share, socialize, and collaborate with students, colleagues, and newly developed network contacts. School librarians are finding that Web 2.0 tools are bringing them more ways to embrace and…

  15. Young Adult Literature 2.0

    ERIC Educational Resources Information Center

    Hamilton, Buffy

    2009-01-01

    Web 2.0 tools enable today's writers to connect with their audience in unprecedented ways. The advent of social networking and other Web 2.0 tools have changed the rules for how authors and book publishers market and communicate with their audience. Through tools like blogs, Twitter, MySpace, and Facebook, Young Adult (YA) lit authors can choose…

  16. 20 CFR 615.2 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) approved April 20, 1983. (b) Base period means, with respect to an individual, the base period as... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Definitions. 615.2 Section 615.2 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR EXTENDED BENEFITS IN THE...

  17. 20 CFR 615.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) approved April 20, 1983. (b) Base period means, with respect to an individual, the base period as... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Definitions. 615.2 Section 615.2 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR EXTENDED BENEFITS IN THE...

  18. Breathing Fire into Web 2.0

    ERIC Educational Resources Information Center

    Hardman, Justin; Carpenter, David

    2007-01-01

    Today's methods of social networking and the technologies that support them offer powerful examples of how educators can connect to the "real" world of client population. To fully engage with the Web 2.0 world, educators work to include aspects of Web 2.0 into their teaching through the use of wikis, forums, and blogs. Administrators are also…

  19. HEXIT-SAT: a mission concept for x-ray grazing incidence telescopes from 0.5 to 70 keV

    NASA Astrophysics Data System (ADS)

    Fiore, Fabrizio; Perola, Giuseppe C.; Pareschi, Giovanni; Citterio, Oberto; Anselmi, Alberto; Comastri, Andrea

    2004-10-01

    While the energy density of the Cosmic X-ray Background (CXB) provides a statistical estimate of the super massive black hole (SMBH) growth and mass density in the Universe, the lack, so far, of focusing instrument in the 20-60 keV (where the CXB energy density peaks), frustrates our effort to obtain a comprehensive picture of the SMBH evolutionary properties. HEXIT-SAT (High Energy X-ray Imaging Telescope SATellite) is a mission concept capable of exploring the hard X-ray sky with focusing/imaging instrumentation, to obtain an unbiased census of accreting SMBH up to the redshifts where galaxy formation peaks, and on extremely wide luminosity ranges. This will represent a leap forward comparable to that achieved in the soft X-rays by the Einstein Observatory in the late 70'. In addition to accreting SMBH, and very much like the Einstein Observatory, this mission would also have the capabilities of investigating almost any type of the celestial X-ray sources. HEXIT-SAT is based on high throughput (>400 cm2 @ 30 keV; >1200 cm2 @ 1 keV), high quality (15 arcsec Half Power Diameter) multi-layer optics, coupled with focal plane detectors with high efficiency in the full 0.5-70keV range. Building on the BeppoSAX experience, a low-Earth, equatorial orbit, will assure a low and stable particle background, and thus an extremely good sensitivity for faint hard X-ray sources. At the flux limits of 1/10 microCrab (10-30 keV) and 1/3 microCrab (20-40 keV) (reachable in one Msec observation) we should detect ~100 and ~40 sources in the 15 arcmin FWHM Field of View respectively, thus resolving >80% and ~65% of the CXB where its energy density peaks.

  20. New constraints on the 2-10 keV X-ray luminosity function from the Chandra COSMOS Legacy Survey

    NASA Astrophysics Data System (ADS)

    Marchesi, Stefano; Civano, Francesca M.; Elvis, Martin; Urry, C. Megan; Comastri, Andrea; Chandra Cosmos Legacy Team

    2015-01-01

    In this talk, we present new results on number counts and luminosity function in the 0.5-2 and 2-10 keV bands, obtained in the Chandra COSMOS Legacy Survey. The COSMOS field is the largest (2 deg2) field with a complete coverage at any wavelength, and the Chandra COSMOS-Legacy survey uniformly covers the 1.7 deg2 COSMOS/HST field to ~160 ksec depth, with a total of 2.8 Ms exposure time. This triples the area of the earlier deep C-COSMOS survey (limiting flux ~3e-16 ergs/cm2/s in the 0.5-2 keV band), and together these two projects cover a total area of 2.2 deg2, yielding a sample of ~4100 X-ray sources, ~2300 of which have been detected in the new observations. We describe how the survey improves our knowledge in the galaxy-super massive black hole co-evolution.

  1. Pickup ions (E/O+/ greater than 55 keV) measured near Mars by Phobos-2 in February/March 1989

    NASA Astrophysics Data System (ADS)

    Kirsch, E.; Keppler, E.; Witte, M.; Rosenbauer, H.; Livi, S.; Schwingenschuh, K.; Afonin, V. V.; O'Sullivan, D.; Thompson, A.; McKenna-Lawlor, S.

    1991-11-01

    The Soviet spacecraft Phobos 2 reached Mars on January 29, 1989. The onboard SLED recorded particles of solar and planetary origin while in elliptical and circular orbits about the planet. Enhanced fluxes were identified, particularly during periods of spin stabilization, superimposed on the general particle intensity time profile. These latter fluxes are interpreted here, using backup evidence from simultaneous solar wind and magnetic field measurements recorded on the same spacecraft, to have constituted pickup ions (/O+/,/O2+/) with E/O+/ not less than 55 keV.

  2. Measurement of mass attenuation coefficients of Rhizophora spp. binderless particleboards in the 16.59-25.26 keV photon energy range and their density profile using x-ray computed tomography.

    PubMed

    Marashdeh, M W; Bauk, S; Tajuddin, A A; Hashim, R

    2012-04-01

    The mass attenuation coefficients of Rhizophora spp. binderless particleboard with four different particle sizes (samples A, B, C and D) and natural raw Rhizophora spp. wood (sample E) were determined using single-beam photon transmission in the energy range between 16.59 and 25.26 keV. This was done by determining the attenuation of K(α1) X-ray fluorescent (XRF) photons from niobium, molybdenum, palladium, silver and tin targets. The results were compared with theoretical values of young-age breast (Breast 1) and water calculated using a XCOM computer program. It was found that the mass attenuation coefficient of Rhizophora spp. binderless particleboards to be close to the calculated XCOM values in water than natural Rhizophora spp. wood. Computed tomography (CT) scans were then used to determine the density profile of the samples. The CT scan results showed that the Rhizophora spp. binderless particleboard has uniform density compared to natural Rhizophora spp. wood. In general, the differences in the variability of the profile density decrease as the particle size of the pellet samples decreases. PMID:22304963

  3. Energy dependence of photon-induced Kα and Kβ x-ray production cross-sections for some elements with 42≤Z≤68 in the energy range 38-80 keV

    NASA Astrophysics Data System (ADS)

    Seven, Sabriye; Erdoğan, Hasan

    2015-12-01

    The energy dependence of photon-induced Kα and Kβ x-ray production cross-sections for Mo, Ru, Pd, In, Sb, Cs, La, Pr, Sm, Tb and Er elements has been studied in the energy range of 38-80 keV with secondary excitation method. K x-ray intensities were measured using Energy Dispersive X-Ray Fluorescence (EDXRF) Spectrometry. The measurements have been made by observing the x-ray emissions, with the help of HPGe detector coupled with a multichannel analyzer. The areas of the Kα and Kβ spectral peaks, as well as the net peak areas, have been determined by a fitting process. The measured Kα and Kβ x-ray production cross-sections have been compared with calculated theoretical values in this energy regime. The results have been plotted versus excitation energy. The present experimental Kα and Kβ x-ray production cross-section values for all the elements were in general agreement with the theoretical values calculated using photoionization cross-sections, fluorescence yields and fractional rates based on Hartree-Slater potentials.

  4. PROPERTIES OF PHANTOM TISSUE-LIKE POLYMETHYLPENTENE IN THE FREQUENCY RANGE 20–70 MHZ

    PubMed Central

    Madsen, Ernest L; Deaner, Meagan E; Mehi, James

    2011-01-01

    Quantitative ultrasound (QUS) has been employed to characterize soft tissues at ordinary abdominal ultrasound frequencies (2–15 MHz) and is beginning application at high frequencies (20–70 MHz). For example, backscatter and attenuation coefficients can be estimated in vivo using a reference phantom. At high frequencies it is crucial that reverberations do not compromise the measurements. Such reverberations can occur between the phantom's scanning window and transducer components as well as within the scanning window between its surfaces. Transducers are designed to minimize reverberations between the transducer and soft tissue. Thus, the acoustic impedance of a phantom scanning window should be tissue-like; polymethylpentene (TPX) is commonly used because of its tissue-like acoustic impedance. For QUS it is also crucial to correct for the transmission coefficient of the scanning window. Computation of the latter requires knowledge of the ultrasonic properties, viz, density, speed and attenuation coefficients. This work reports values for the ultrasonic properties of two versions of TPX over the high frequency range. One form (TPX film) is used as a scanning window on high frequency phantoms, and at 40 MHz and 22°C was found to have an attenuation coefficient of 120 dB/cm and a propagation speed of 2093 m/s. PMID:21723451

  5. Carbon Capture (Carbon Cycle 2.0)

    ScienceCinema

    Smit, Berend

    2011-06-08

    Berend Smit speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 3, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

  6. Transmission images and evaluation of tomographic imaging based scattered radiation from biological materials using 10, 15, 20 and 25 keV synchrotron X-rays: An analysis in terms of optimum energy

    SciTech Connect

    Rao, Donepudi V.; Akatsuka, Takao; Tromba, Giuliana

    2004-05-12

    Transmission images and tomographic imaging based scattered radiation is evaluated from biological materials, for example, Polyethylene, Poly carbonate, Plexiglas and Nylon using 10, 15, 20 and 25 keV synchrotron X-rays. The SYRMEP facility at Elettra,Trieste, Italy and the associated detection system has been used for the image acquisition. The scattered radiation is detected for each sample at three energies at an angle of 90 deg. using Si-Pin detector coupled to a multi-channel analyzer. The contribution of transmitted, Compton and fluorescence photons are assessed for a test phantom of small dimensions. The optimum analysis is performed with the use of the dimensions of the sample and detected radiation at various energies.

  7. SFA 2.0- Metabolic Potential

    SciTech Connect

    Banfield, Jill; Beller, Harry

    2015-02-17

    Berkeley Lab Earth Scientists Jill Banfield and Harry Beller explain the Sustainable Systems SFA 2.0 project's research on metabolic potential—or how metabolic lifestyles of microbial communities modulate in response to as well as influence environmental change.

  8. Lost in Web 2.0 Cyberspace?

    ERIC Educational Resources Information Center

    Fallon, Julia

    2008-01-01

    Web 1.0 never left. It's just a term that refers to cyberspace before 2002. People mark the shift from Web 1.0 to 2.0 with the dramatic collapse of Web-based companies whose phenomenal growth was based on the profit potential of a new customer: the Internet user. Generally, Web 1.0 sites have a commercial focus. On the other hand, Web 2.0 reverses…

  9. Compact MWIR zoom camera with 20:1 zoom range and automatic athermalization

    NASA Astrophysics Data System (ADS)

    Kim, Hyun S.; Kim, Chang W.; Hong, Seok-Min

    2002-07-01

    A compact mid-wavelength infrared zoom camera with a zoom range of 20:1 and automatic athermalization has been developed. The moving groups for a wide zoom range are only two lens groups and the loci of zoom are very simple, which allows easy access of optomechanical and electromechanical design. In addition, the microscanning technique was introduced to improve resolving power. We acquired increased resolving power of 7.6 cycles/mrad, superior to the original Nyquist frequency of 4.5 cycles/mrad. The temperature range, being -30 to +55 degree(s)C, in which the camera is to operate, is rather wide. The minimum resolvable temperature difference of the zoom camera is 0.3 degree(s)C at 6 cycles/mrad.

  10. Combustion and Carbon Cycle 2.0 and Computation in CC 2.0 (Carbon Cycle 2.0)

    ScienceCinema

    Cheng, Robert K; Meza, Juan

    2011-06-08

    Robert Cheng and Juan Meza provide two presentations in one session at the Carbon Cycle 2.0 kick-off symposium Feb. 3, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

  11. The Context for IMAP: Voyager and INCA Observations of the Heliosheath at E > 5 keV

    NASA Astrophysics Data System (ADS)

    Krimigis, Stamatios M.

    2016-04-01

    The basic premise of the proposed Interstellar Mapping and Acceleration Probe (IMAP) is detailed scientific understanding of the Heliosheath (HS) and beyond, a region of space explored in situ by Voyager 1 (V1) since 2004, Voyager 2 (V2) since 2007, and remotely via energetic neutral atoms (ENA) by the Cassini/INCA (Ion and Neutral CAmera) since 2003 and IBEX since 2009. The IMAP instrumentation proposed for this purpose combines and extends the IBEX and INCA ENA energy ranges (0.3- 20 keV and 3-200 keV, for low and high energy, respectively). All three missions-Voyagers, Cassini/INCA, and IBEX- have made discovery-class measurements in the HS, the Voyagers providing in situ ion intensities at E > 30 keV, while INCA images ENA in the range 5 < E < 55 keV, and IBEX 0.3 < E < 6 keV. The partial overlap in energy coverage between Voyager ions and INCA ENA allows for the possibility of observing the intensity and time evolution of ions in the HS, thought to give rise to the ENAs via charge-exchange, and the resultant ENA images in the inner heliosphere and their spatial and/or temporal variability. Unfortunately, no such "ground truth" ion measurements are possible at Voyager in the ENA energy range imaged by IBEX. Some of the key findings from the Voyager and Cassini/INCA measurements are as follows: (1) The HS contains a hot plasma population that carries a substantial part (30-50 %) of the total pressure at E > 5 keV, the rest residing below that range, resulting in a beta (particle/magnetic pressure) always > 1, typically >10. (2) The width of the HS in the direction of V1 is ~ 30 AU, but is thought to be larger (40-70 AU) in the southern ecliptic where V2 currently travels.. (3) The ENA intensities at E > 5 keV exhibit a correlation with the solar cycle (SC) over the period 2003 to 2015, with minimum intensities in the anti-nose direction observed ~ 1.5 yrs after solar minimum followed by a recovery thereafter. (4) The in situ ion measurements at V2 within the HS

  12. 20 CFR 703.2 - Forms.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Forms. 703.2 Section 703.2 Employees' Benefits EMPLOYMENT STANDARDS ADMINISTRATION, DEPARTMENT OF LABOR LONGSHOREMEN'S AND HARBOR WORKERS' COMPENSATION ACT AND RELATED STATUTES INSURANCE REGULATIONS General § 703.2 Forms. (a) Any information required by the regulations in this part to...

  13. 20 CFR 604.2 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 3 2012-04-01 2012-04-01 false Definitions. 604.2 Section 604.2 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR REGULATIONS FOR ELIGIBILITY FOR UNEMPLOYMENT COMPENSATION § 604.2 Definitions. (a) Department means the United States Department of Labor....

  14. 20 CFR 604.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Definitions. 604.2 Section 604.2 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR REGULATIONS FOR ELIGIBILITY FOR UNEMPLOYMENT COMPENSATION § 604.2 Definitions. (a) Department means the United States Department of Labor....

  15. 20 CFR 602.2 - Scope.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 3 2012-04-01 2012-04-01 false Scope. 602.2 Section 602.2 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR QUALITY CONTROL IN THE FEDERAL-STATE UNEMPLOYMENT INSURANCE SYSTEM General Provisions § 602.2 Scope. This part applies to all State laws approved...

  16. 20 CFR 602.2 - Scope.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Scope. 602.2 Section 602.2 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR QUALITY CONTROL IN THE FEDERAL-STATE UNEMPLOYMENT INSURANCE SYSTEM General Provisions § 602.2 Scope. This part applies to all State laws approved by the Secretary under the...

  17. 20 CFR 229.2 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Definitions. 229.2 Section 229.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT SOCIAL SECURITY OVERALL MINIMUM GUARANTEE General § 229.2 Definitions. The following definitions are used in this part: Annuity means a payment under the...

  18. 20 CFR 703.2 - Forms.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Forms. 703.2 Section 703.2 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR LONGSHOREMEN'S AND HARBOR WORKERS' COMPENSATION ACT AND RELATED STATUTES INSURANCE REGULATIONS General § 703.2 Forms. (a) Any information required by the regulations in this part to...

  19. Global Impacts (Carbon Cycle 2.0)

    ScienceCinema

    Gadgil, Ashok [EETD and UC Berkeley

    2011-06-08

    Ashok Gadgil, Faculty Senior Scientist and Acting Director, EETD, also Professor of Environmental Engineering, UC Berkeley, speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 2, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

  20. Global Impacts (Carbon Cycle 2.0)

    SciTech Connect

    Gadgil, Ashok

    2010-02-02

    Ashok Gadgil, Faculty Senior Scientist and Acting Director, EETD, also Professor of Environmental Engineering, UC Berkeley, speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 2, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

  1. 33 CFR 334.20 - Gulf of Maine off Cape Small, Maine; naval aircraft practice mining range area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., Maine; naval aircraft practice mining range area. 334.20 Section 334.20 Navigation and Navigable Waters... REGULATIONS § 334.20 Gulf of Maine off Cape Small, Maine; naval aircraft practice mining range area. (a) The... the area. (5) The regulations of this section shall be enforced by the Commandant, First...

  2. 33 CFR 334.20 - Gulf of Maine off Cape Small, Maine; naval aircraft practice mining range area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., Maine; naval aircraft practice mining range area. 334.20 Section 334.20 Navigation and Navigable Waters... REGULATIONS § 334.20 Gulf of Maine off Cape Small, Maine; naval aircraft practice mining range area. (a) The... the area. (5) The regulations of this section shall be enforced by the Commandant, First...

  3. 20 CFR 625.2 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 3 2012-04-01 2012-04-01 false Definitions. 625.2 Section 625.2 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR DISASTER UNEMPLOYMENT ASSISTANCE § 625... Unemployment Assistance in the State, pursuant to § 625.17. (d) Compensation means unemployment compensation...

  4. 20 CFR 368.2 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false Definitions. 368.2 Section 368.2 Employees' Benefits RAILROAD RETIREMENT BOARD INTERNAL ADMINISTRATION, POLICY AND PROCEDURES PROHIBITION OF CIGARETTE.... Tobacco product means cigarettes, cigars, little cigars, pipe tobacco, smokeless tobacco, snuff,...

  5. 20 CFR 368.2 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Definitions. 368.2 Section 368.2 Employees' Benefits RAILROAD RETIREMENT BOARD INTERNAL ADMINISTRATION, POLICY AND PROCEDURES PROHIBITION OF CIGARETTE.... Tobacco product means cigarettes, cigars, little cigars, pipe tobacco, smokeless tobacco, snuff,...

  6. 20 CFR 368.2 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 1 2014-04-01 2012-04-01 true Definitions. 368.2 Section 368.2 Employees' Benefits RAILROAD RETIREMENT BOARD INTERNAL ADMINISTRATION, POLICY AND PROCEDURES PROHIBITION OF CIGARETTE.... Tobacco product means cigarettes, cigars, little cigars, pipe tobacco, smokeless tobacco, snuff,...

  7. 20 CFR 368.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Definitions. 368.2 Section 368.2 Employees' Benefits RAILROAD RETIREMENT BOARD INTERNAL ADMINISTRATION, POLICY AND PROCEDURES PROHIBITION OF CIGARETTE.... Tobacco product means cigarettes, cigars, little cigars, pipe tobacco, smokeless tobacco, snuff,...

  8. 20 CFR 368.2 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Definitions. 368.2 Section 368.2 Employees' Benefits RAILROAD RETIREMENT BOARD INTERNAL ADMINISTRATION, POLICY AND PROCEDURES PROHIBITION OF CIGARETTE.... Tobacco product means cigarettes, cigars, little cigars, pipe tobacco, smokeless tobacco, snuff,...

  9. 20 CFR 615.2 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... systematic and sustained effort, for the purposes of section 202(a)(3)(E), means— (i) A high level of job... 20 Employees' Benefits 3 2014-04-01 2014-04-01 false Definitions. 615.2 Section 615.2 Employees...) approved September 3, 1982, and the 1983 amendment in section 522 of Pub. L. 98-21 (97 Stat. 65,...

  10. 20 CFR 615.2 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... systematic and sustained effort, for the purposes of section 202(a)(3)(E), means— (i) A high level of job... 20 Employees' Benefits 3 2013-04-01 2013-04-01 false Definitions. 615.2 Section 615.2 Employees...) approved September 3, 1982, and the 1983 amendment in section 522 of Pub. L. 98-21 (97 Stat. 65,...

  11. 20 CFR 302.2 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Definitions. 302.2 Section 302.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD UNEMPLOYMENT INSURANCE ACT QUALIFIED... period. With respect to unemployment benefits, the term “registration period” has the meaning given...

  12. 20 CFR 302.2 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false Definitions. 302.2 Section 302.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD UNEMPLOYMENT INSURANCE ACT QUALIFIED... period. With respect to unemployment benefits, the term “registration period” has the meaning given...

  13. 20 CFR 302.2 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 1 2014-04-01 2012-04-01 true Definitions. 302.2 Section 302.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD UNEMPLOYMENT INSURANCE ACT QUALIFIED... period. With respect to unemployment benefits, the term “registration period” has the meaning given...

  14. 20 CFR 302.2 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Definitions. 302.2 Section 302.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD UNEMPLOYMENT INSURANCE ACT QUALIFIED... period. With respect to unemployment benefits, the term “registration period” has the meaning given...

  15. Electron inelastic interactions in bioorganic compounds in the energy range of 20 10000 eV

    NASA Astrophysics Data System (ADS)

    Tan, Z.; Xia, Y.; Liu, X.; Zhao, M.; Ji, Y.; Li, F.; Huang, B.

    2005-09-01

    Systematic calculations of stopping powers (SPs) and mean free paths (MFPs) for 10 bioorganic compounds have been performed for electrons with energies lower than 10 keV, based on dielectric response theory and Penn’s statistical approximation. The exchange effect is also taken into account in the calculations. An empirical approach to obtain an optical energy loss function is presented for those organic compounds without available optical data. Using this method, the calculated values of the optical energy loss function are in good agreement with experimental data. Comparisons of SP and MFP values derived in this study with other published values are presented. Using the described model, the calculated mean ionization potentials agree well with the predictions from Bragg’s rule and the calculated SPs have also been compared with the Bethe Bloch results at an energy of 10 keV.

  16. Web 2.0 and Pharmacy Education

    PubMed Central

    Fox, Brent I.

    2009-01-01

    New types of social Internet applications (often referred to as Web 2.0) are becoming increasingly popular within higher education environments. Although developed primarily for entertainment and social communication within the general population, applications such as blogs, social video sites, and virtual worlds are being adopted by higher education institutions. These newer applications differ from standard Web sites in that they involve the users in creating and distributing information, hence effectively changing how the Web is used for knowledge generation and dispersion. Although Web 2.0 applications offer exciting new ways to teach, they should not be the core of instructional planning, but rather selected only after learning objectives and instructional strategies have been identified. This paper provides an overview of prominent Web 2.0 applications, explains how they are being used within education environments, and elaborates on some of the potential opportunities and challenges that these applications present. PMID:19960079

  17. A Review of X-ray Diagnostic Calibrations in the 2 to 100 keV Region Using the High Energy X-ray Calibration Facility (HEX)

    SciTech Connect

    Ali, Zaheer; Pond, T; Buckles, R A; Maddox, B R; Chen, C D; DeWald, E L; Izumi, N; Stewart, R

    2010-05-19

    The precise and accurate measurement of X-rays in the 2 keV to 100 keV region is crucial to the understanding of HED plasmas and warm dense matter in general. With the emergence of inertially confined plasma facilities as the premier platforms for ICF, laboratory astrophysics, and national security related plasma experiments, the need to calibrate diagnostics in the high energy X-ray regime has grown. At National Security Technologies High Energy X-ray Calibration Facility (HEX) in Livermore, California, X-ray imagers, filter-fluorescer spectrometers, crystal spectrometers, image plates, and nuclear diagnostics are calibrated. The HEX can provide measurements of atomic line radiation, X-ray flux (accuracy within 10%), and X-ray energy (accuracy within 1%). The HEX source is comprised of a commercial 160 kV X-ray tube, a fluorescer wheel, a filter wheel, and a lead encasement. The X-ray tube produces a Tungsten bremsstrahlung spectrum which causes a foil to fluoresce line radiation. To minimize bremsstrahlung in the radiation for calibration we also provide various foils as filters. For experimental purposes, a vacuum box capable of 10{sup -7} Torr, as well as HPGe and CdTe radiation detectors, are provided on an optical table. Most geometries and arrangements can be changed to meet experimental needs.

  18. 50 CFR 30.2 - Disposition of surplus range animals.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Disposition of surplus range animals. 30.2... (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM RANGE AND FERAL ANIMAL MANAGEMENT Range Animals § 30.2 Disposition of surplus range animals. Disposition shall be made only during regularly scheduled...

  19. 50 CFR 30.2 - Disposition of surplus range animals.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Disposition of surplus range animals. 30.2... (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM RANGE AND FERAL ANIMAL MANAGEMENT Range Animals § 30.2 Disposition of surplus range animals. Disposition shall be made only during regularly scheduled...

  20. 50 CFR 30.2 - Disposition of surplus range animals.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Disposition of surplus range animals. 30.2... (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM RANGE AND FERAL ANIMAL MANAGEMENT Range Animals § 30.2 Disposition of surplus range animals. Disposition shall be made only during regularly scheduled...

  1. 50 CFR 30.2 - Disposition of surplus range animals.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Disposition of surplus range animals. 30.2... (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM RANGE AND FERAL ANIMAL MANAGEMENT Range Animals § 30.2 Disposition of surplus range animals. Disposition shall be made only during regularly scheduled...

  2. 50 CFR 30.2 - Disposition of surplus range animals.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Disposition of surplus range animals. 30.2... (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM RANGE AND FERAL ANIMAL MANAGEMENT Range Animals § 30.2 Disposition of surplus range animals. Disposition shall be made only during regularly scheduled...

  3. Correlation between multiple ionization and fragmentation of C2H6 in charge-changing collisions with 580 -keV C+

    NASA Astrophysics Data System (ADS)

    Majima, T.; Murai, T.; Kishimoto, T.; Adachi, Y.; Yoshida, S. O.; Tsuchida, H.; Itoh, A.

    2014-12-01

    We investigate correlations between multiple ionization and fragmentation processes of the ethane molecule in collisions with 580 -keV C+ ions under single-electron capture and loss conditions. Employing an electron counting technique, we directly obtain number distributions of ionized electrons, which correspond to distributions of multiple ionization probabilities of ethane. In addition, fragmentation patterns as a function of the charge state r of intermediate parent ions C2H6 r +* are obtained from coincidence measurements between the time of flight of the product ions and the number of electrons emitted. Fragmentation patterns in the different charge-changing conditions reveal a crucial role of the internal excitation in the fragmentation processes. Also, we provide clear evidence of strong selectivity on the parent charge state for formation of the H3 + ion, which is exclusively generated through doubly charged parent ions C2H6 2 +* .

  4. Looking for Collection 2.0

    ERIC Educational Resources Information Center

    Buczynski, James A.

    2008-01-01

    Libraries are integrating Web 2.0 services into work practices, positioning themselves in online social environments, and deploying enhanced search and discovery tools. Collections conversely are not progressing to the same degree. Like many public services today, library budgets are stained. User-pay options are appearing in library systems,…

  5. Three Challenges of Web 2.0

    ERIC Educational Resources Information Center

    Reeves, Douglas B.

    2009-01-01

    There's no doubt that Web 2.0--the social and technological phenomenon that enables users to generate content, interact, and share information across borders--can be a force for good in the world of education. The author's enthusiasm for collaborative Web-based content is tempered, however, by concern about these three challenges: (1) Partners…

  6. Change Management Meets Web 2.0

    ERIC Educational Resources Information Center

    Gale, Doug

    2008-01-01

    Web 2.0 is the term used to describe a group of web-based creativity, information-sharing, and collaboration tools including wikis, blogs, social networks, and folksonomies. The common thread in all of these tools is twofold: They enable collaboration and information sharing, and their impact on higher education has been dramatic. A recent study…

  7. Professional Development and Web 2.0

    ERIC Educational Resources Information Center

    Jakes, David

    2007-01-01

    Professional development in most schools has a predictable look and feel: summer workshops, brown-bag luncheon trainings, and the infamous in-service day. These events can be successful, and there is no doubt they have helped numerous educators become better at what they do. Web 2.0, however, opens up a new world of professional learning. This…

  8. Sustainable Systems SFA 2.0

    SciTech Connect

    Hubbard, Susan

    2015-12-19

    Berkeley Lab Earth Sciences Division Director Susan Hubbard, the Project Lead for the Sustainable Systems Scientific Focus Area (SFA) 2.0, gives an overview of the project and its mission to develop a predictive understanding of terrestrial environments, from the genome to the watershed scales, to enable a new class of solutions for environmental and energy solutions.

  9. Social Participation in Health 2.0

    PubMed Central

    Hesse, Bradford W.; Hansen, Derek; Finholt, Thomas; Munson, Sean; Kellogg, Wendy; Thomas, John C.

    2010-01-01

    Computer scientists are working with biomedical researchers, policy specialists, and medical practitioners to usher in a new era in healthcare. A recently convened panel of experts considered various research opportunities for technology-mediated social participation in Health 2.0. PMID:21379365

  10. Early 20th-century uplift of the northern Peninsular ranges province of southern California

    USGS Publications Warehouse

    Wood, S.H.; Elliott, M.R.

    1979-01-01

    Repeated leveling in the northern Peninsular Ranges province identifies an early 20thcentury episode of crustal upwarping in southern California. The episodic vertical movement is broadly bracketed between 1897 and 1934, and the main deformation is bracketed within 1906-1914 and involved regional up-to-the-northeast tilting of the Santa Ana block of as much as 4 ?? 10-6 rad and elevation changes exceeding 0.4 m in the Perris block and parts of the San Jacinto block, Transverse Ranges, and the Mohave block. Primary tide station records containing occasional entries since 1853 at San Pedro and San Diego show no evidence of episodic crustal movement, suggesting that the uplifted area hinged along coastal fault zones forming the west boundary of the Santa Ana block. Physiographic features and recent studies of Quaternary marine terraces by others show that this episode of regional tilting and uplift is a part of the continuing tectonic process in southern California. A crude, questionable coincidence exists between the uplift episode and a period of increased seismicity (1890-1923) in the northern Peninsular Ranges characterized by a number of moderate-size (M > 6) earthquakes on NW-trending strike-slip faults. However, releveling data are too sparse to associate the uplift development clearly with any one event. ?? 1979.

  11. Lunar Laser Ranging Experiment for Japanese SELENE-2 landing mission

    NASA Astrophysics Data System (ADS)

    Noda, H.; Kunimori, H.; Araki, H.; Fuse, T.; Hanada, H.; Katayama, M.; Otsubo, T.; Sasaki, S.; Tazawa, S.; Tsuruta, S.; Funazaki, K.; Taniguchi, H.; Murata, K.

    2012-04-01

    We present the development status of the Lunar Laser Ranging experiment proposed to Japanese SELENE-2 lunar landing mission. The Lunar Laser Ranging measures the distance between laser link stations on the Earth and retroreflectors on the Moon, by detecting the time of flight of photons of high-powered laser emitted from the ground station. Since the Earth-Moon distance contains information of lunar orbit, lunar solid tides, and lunar orientation and rotation, we can estimate the inner structure of the Moon through orientation, rotation and tide. Retroreflectors put by the Apollo and Luna missions in 1970's are arrays of many small Corner Cube Prisms (CCP). Because of the tilt of these arrays from the Earth direction due to the optical libration, the returned laser pulse is broaden, causing the main range error of more than 1.5 cm ([1]). Therefore retroreflectors with larger single aperture are necessary for more accurate ranging, and we propose a large single retroreflector of hollow-type with 15 cm aperture. Larger aperture up to 20 cm might be favorable if more mass is permitted for payloads. To cancel the velocity aberration, a large, single aperture retroreflector needs small amount of offset angle between the reflecting planes to spoil the return beam pattern. This angle offset, called Dihedral Angle Offset (DAO) must be optimized to be less than 1 second of arc with 0.1 seconds of arc accuracy to accumulate more photons [2, 3]. The realization of such small DAO is challenging with current technology, therefore the development of fabrication method is important. As for the mirror material, some ceramic products (ZPF: Zero-expansion Pore-free ceramics or SiC: silicon carbide) are under consideration in terms of weight, hardness and handling. The thermal quality of the material can be evaluated by both the thermal conductivity and the coefficient of thermal expansion. The method to fasten three planes each other with precise DAO must be developed.

  12. Using Web 2.0 for Learning in the Community

    ERIC Educational Resources Information Center

    Mason, Robin; Rennie, Frank

    2007-01-01

    This paper describes the use of a range of Web 2.0 technologies to support the development of community for a newly formed Land Trust on the Isle of Lewis, in NW Scotland. The application of social networking tools in text, audio and video has several purposes: informal learning about the area to increase tourism, community interaction,…

  13. Weak Solar Flares in 3 -31.5 keV X-rays Detected in the Coronas-F Experiment

    NASA Astrophysics Data System (ADS)

    Gusev, Anatoly; Pugacheva, Galina; Martin, Inácio M.; Spjeldvik, Walther

    The RPS-1 spectrometer on the board of the Coronas-F satellite detecting solar X-rays in the range of 3-31.5 keV using a CdTe detector is described and some results of the observation of weak solar flares are presented. The detector has a high detection efficiency and radiation damage resistance necessary for long time space experiments. It has an active area of 46 mm2, a thickness of 1.4 mm, an operation voltage of 100 V, an energy resolution of 0.88 keV (13.87 keV Am241), a power consumption of 8.5 W, and a mass of 1.8 kg. The width of the first 12 channels (3-9 keV) is 0.5 keV, the width of the next 12 channels is 1 keV, and the width of the last 8 channels (21-31.5 keV) is 1.3 keV. The spectrum accumulation time in 32 channels is 16 s. The spectrometer provides vast experimental data on the spectra of soft X-ray emission of solar flares. The high spectral resolution of the instrument allows an investigation of the dynamics of the temperature in the source using the direct comparison of the spectrum shape with some models, for example, with the CHIANTI 5.2 model. It was noted that hardness of the spectrum in the flare maximum increases with the flare class and solar activity level. The magnetic heating of the corona was confirmed by the spectra of the background solar X ray radiation for various numbers of sunspots: the more sunspots, the harder the spectrum of the X-ray background radiation was registered and, respectively, the stronger was the impact on the Earth's atmosphere. Near the solar activity maximum, the background radiation intensity increased by more than an order of magnitude and the maximum energy increased from 6 to 20 keV. (To the memory of Drs. V.M. Pankov and V.L. Prokhin, colleagues and coworkers in the Coronas-F mission.)

  14. Liquid helium cryostat with internal fluorescence detection for x-ray absorption studies in the 2-6 keV energy region

    NASA Astrophysics Data System (ADS)

    McFarlane Holman, Karen L.; Latimer, Matthew J.; Yachandra, Vittal K.

    2004-06-01

    X-ray absorption spectroscopy (XAS) in the intermediate x-ray region (2-6 keV) for dilute biological samples has been limited because of detector/flux limitations and inadequate cryogenic instrumentation. We have designed and constructed a new tailpiece/sample chamber for a commercially available liquid helium cooled cryostat which overcomes difficulties related to low fluorescence signals by using thin window materials and incorporating an internal photodiode detector. With the apparatus, XAS data at the Cl, S, and Ca K edges have been collected on frozen solutions and biological samples at temperatures down to 60 K. A separate chamber has been incorporated for collecting room-temperature spectra of standard compounds (for energy calibration purposes) which prevents contamination of the cryostat chamber and allows the sample to remain undisturbed, both important concerns for studying dilute and radiation-sensitive samples.

  15. Damage behavior and atomic migration in MgAl2O4 under an 80 keV scanning focused probe in a STEM.

    PubMed

    Zhu, Guo-zhen; Botton, Gianluigi A

    2015-01-01

    With the dramatic improvement in the spatial resolution of scanning transmission electron microscopes over the past few decades, the tolerance of a specimen to the high-energy electron beam becomes the limiting factor for the quality of images and spectra obtained. Therefore, a deep understanding of the beam irradiation processes is crucial to extend the applications of electron microscopy. In this paper, we report the structural evolution of a selected oxide, MgAl2O4, under an 80 keV focused electron probe so that the beam irradiation process is not dominated by the knock-on mechanism. The formation of peroxyl bonds and the assisted atomic migration were studied using imaging and electron energy-loss spectroscopic techniques. PMID:25043440

  16. A comparison of MCNP4C electron transport with ITS 3.0 and experiment at incident energies between 100 keV and 20 MeV: influence of voxel size, substeps and energy indexing algorithm

    NASA Astrophysics Data System (ADS)

    Schaart, Dennis R.; Jansen, Jan Th M.; Zoetelief, Johannes; de Leege, Piet F. A.

    2002-05-01

    The condensed-history electron transport algorithms in the Monte Carlo code MCNP4C are derived from ITS 3.0, which is a well-validated code for coupled electron-photon simulations. This, combined with its user-friendliness and versatility, makes MCNP4C a promising code for medical physics applications. Such applications, however, require a high degree of accuracy. In this work, MCNP4C electron depth-dose distributions in water are compared with published ITS 3.0 results. The influences of voxel size, substeps and choice of electron energy indexing algorithm are investigated at incident energies between 100 keV and 20 MeV. Furthermore, previously published dose measurements for seven beta emitters are simulated. Since MCNP4C does not allow tally segmentation with the *F8 energy deposition tally, even a homogeneous phantom must be subdivided in cells to calculate the distribution of dose. The repeated interruption of the electron tracks at the cell boundaries significantly affects the electron transport. An electron track length estimator of absorbed dose is described which allows tally segmentation. In combination with the ITS electron energy indexing algorithm, this estimator appears to reproduce ITS 3.0 and experimental results well. If, however, cell boundaries are used instead of segments, or if the MCNP indexing algorithm is applied, the agreement is considerably worse.

  17. The Observation of the 3/2(+) State of F-19 at E(X) = 7101 Kev and its Relation to Explosive Stellar Hydrogen Burning

    NASA Astrophysics Data System (ADS)

    Butt, Yousaf Mahmood

    1998-10-01

    In extremely hot and dense astrophysical environments, such as in novae events, the energy generation mechanism may shift from cyclic processes involving hydrogen fusion reactions on only low mass (A < 19) nuclei (the HotCNO cycles), to a violent thermonuclear runaway producing heavier mass nuclei up to 68Se and higher (the rp-process). This shift will determine the power output and the timescale of the explosive event and is, thus, clearly important to understand. One of the pathways for this transition to occur is via the 18F(p,/gamma)19Ne reaction which channels material away from the HotCNO cycles to the rp-process. This reaction competes with the 18F(p,α)15O reaction which returns material back to the HotCNO cycles. To determine the temperatures and densities under which such a transition may occur one must know the locations, widths, and spin-parities of resonant states in the compound nucleus 19Ne just above the 18F + p threshold. The purpose of this work was to check on the existence of the astrophysically important 3/2+ resonant state recently reported in 19Ne at E x~ 7.07 MeV, by searching for its isospin mirror state in 19F. This mirror state was, indeed, observed via the 15N(α,γ)19F reaction to lie at E x = 7101 ± 1 keV, with alpha width, Γα≅ Γ tot = 28 ± 1.1 keV, γ-width, Γgamma = 0.38 ± 0.06 eV, and resonance strength, ωgamma = 0.77 ± 0.11 eV. Under the assumption of equivalent alpha structure of the mirror states, the alpha width of the 19Ne state was determined to be ~30 keV. This is in resonable agreement with two previous studies, but in disagreement, by a factor of ~3, with one. The latest information indicates that the 18F(p,/gamma)19Ne reaction rate under astrophysical conditions is too low for it to be an important pathway for breakout from the HotCNO cycles to the rp-process.

  18. Improving the energy response of external beam therapy (EBT) GafChromic{sup TM} dosimetry films at low energies (≤100 keV)

    SciTech Connect

    Bekerat, H. Devic, S.; DeBlois, F.; Singh, K.; Sarfehnia, A.; Seuntjens, J.; Shih, Shelley; Yu, Xiang; Lewis, D.

    2014-02-15

    Purpose: Purpose of this work is to investigate the effects of varying the active layer composition of external beam therapy (EBT) GafChromic{sup TM} films on the energy dependence of the film, as well as try to develop a new prototype with more uniform energy response at low photon energies (⩽100 keV). Methods: First, the overall energy response (S{sub AD,} {sub W}(Q)) of different commercial EBT type film models that represent the three different generations produced to date, i.e., EBT, EBT2, and EBT3, was investigated. Pieces of each film model were irradiated to a fixed dose of 2 Gy to water for a wide range of beam qualities and the corresponding S{sub AD,} {sub W}(Q) was measured using a flatbed document scanner. Furthermore, the DOSRZnrc Monte Carlo code was used to determine the absorbed dose to water energy dependence of the film, f(Q). Moreover, the intrinsic energy dependence, k{sub bq}(Q), for each film model was evaluated using the corresponding S{sub AD,} {sub W}(Q) and f(Q). In the second part of this study, the authors investigated the effects of changing the chemical composition of the active layer on S{sub AD,} {sub W}(Q). Finally, based on these results, the film manufacturer fabricated several film prototypes and the authors evaluated their S{sub AD,} {sub W}(Q). Results: The commercial EBT film model shows an under response at all energies below 100 keV reaching 39% ± 4% at about 20 keV. The commercial EBT2 and EBT3 film models show an under response of about 27% ± 4% at 20 keV and an over response of about 16% ± 4% at 40 keV.S{sub AD,} {sub W}(Q) of the three commercial film models at low energies show strong correlation with the corresponding f{sup −1}(Q) curves. The commercial EBT3 model with 4% Cl in the active layer shows under response of 22% ± 4% at 20 keV and 6% ± 4% at about 40 keV. However, increasing the mass percent of chlorine makes the film more hygroscopic which may affect the stability of the film's readout. The

  19. The repetitive flaking of inconel 625 by 100 keV helium ion bombardment

    NASA Astrophysics Data System (ADS)

    Whitton, J. L.; Chen, Hao Ming; Littmark, U.; Emmoth, B.

    1981-05-01

    Repetitive flaking of Inconel 625 occurs with ion bombardment doses of than 10 18 100 keV helium ions cm -2, with up to 39 exfoliations being observed after bombardment with 3 × 10 19 ions cm -2. The thickness of the flakes, measured by scanning electron microscopy, is some 30% greater than when measured by Rutherford backscattering (RBS) of 1.8 MeV helium ions. These RBS measurements compare well with the thickness of the remaining layers in the resultant craters and to the most probable range of the 100 keV helium. The area of the flakes is dictated by the grain boundaries, and when one flake is ejected, the adjacent grains are prevented from doing so since there now exists an escape route for the injected helium. A strong dose rate dependence is observed; decreasing the beam current from 640 μA cm -2 to 64 μA cm -2 results in a factor 20 fewer flakes being exfoliated (for the same total dose of 3 × 10 19 ions cm -2). Successive flakes decrease in area, suggesting that eventually a cratered, but stable, surface will result with the only erosion being by the much less effective mechanism of sputtering.

  20. Differential cross sections for scattering of 0.5-, 1.5-, and 5.0-keV hydrogen atoms by He, H2, N2, and O2

    NASA Technical Reports Server (NTRS)

    Newman, J. H.; Chen, Y. S.; Smith, K. A.; Stebbings, R. F.

    1986-01-01

    This paper reports measurements of absolute cross sections, differential in angle, for scattering of 0.5-, 1.5-, and 5.0-keV hydrogen atoms by He, H2, N2, and O2 at laboratory scattering angles between 0.1 and 5 deg. The measured cross sections are the sums of those for elastic and inelastic collisions having a fast H atom product and are needed for calculating energy transfer to the upper atmosphere from precipitating ring current particles.

  1. Magnetic Order in TbCo2Zn20 and TbFe2Zn20

    SciTech Connect

    Tian, W.; Christianson, Andrew D; Zarestky, J. L.; Jia, S.; Bud'ko, S. L.; Canfield, P. C.; Piccoli, P. M. B.; Schultz, A. J.

    2010-01-01

    We report neutron di raction studies of TbCo2Zn20 and TbFe2Zn20, two isostructural compounds which exhibit dramatically di erent magnetic behavior. In the case of TbCo2Zn20, magnetic Bragg peaks corresponding to antiferromagnetic order are observed below TN 2.5 K with a propagation vector of (0.5 0.5 0.5). On the other hand, TbFe2Zn20 undergoes a ferromagnetic transition at temperatures as high as 66 K which shows a high sensitivity to sample-to-sample variations. Two samples of TbFe2Zn20 with the same nominal compositions but with substantially di erent mag- netic ordering temperatures (Tc 51 and 66 K) were measured by single crystal neutron di raction. Structural re nements of the neutron di raction data nd no direct signature of atomic site disorder between the two TbFe2Zn20 samples except for subtle di erences in the anisotropic thermal param- eters. The di erences in the anisotropic thermal parameters between the two samples is likely due to very small amounts of disorder. This provides further evidence for the extreme sensitivity of the magnetic properties of TbFe2Zn20 to small sample variations, even small amounts of disorder.

  2. 700 keV Ni+2 ions induced modification in structural, surface, magneto-optic and optical properties of ZnO thin films

    NASA Astrophysics Data System (ADS)

    Fiaz Khan, M.; Siraj, K.; Anwar, M. S.; Irshad, M.; Hussain, J.; Faiz, H.; Majeed, S.; Dosmailov, M.; Patek, J.; Pedarnig, J. D.; Rafique, M. S.; Naseem, S.

    2016-02-01

    We investigate the effect of 700 keV Ni+2 ions irradiation at different ion fluences (1 × 1013, 1 × 1014, 2 × 1014, 5 × 1014 ions/cm2) on the structural, surface, magneto-optic and optical properties of ZnO thin films. The X-ray diffraction (XRD) results show improved crystallinity when ion fluence is increased to 2 × 1014 ions/cm2, while deterioration is observed at the highest ion fluence of 5 × 1014 ions/cm2. Scanning electron micrographs (SEM) show the formation of small grains at ion fluence 1 × 1013 ions/cm2, micro-rods at fluences 1 × 1014 and 2 × 1014 ions/cm2 and ultimate fracturing of thin film surface at ion fluence 5 × 1014 ions/cm2. Faraday rotation measurements are also performed and show a decrease in Verdet constant from 53 to 31 rad/(T-m) when irradiated at 1 × 1013 ions/cm2, increasing up to 45 rad/(T-m) at 2 × 1014 ions/cm2, and then decreasing again to 36 rad/(T-m) at 5 × 1014 ions/cm2. The optical band gap energy of the films is determined using spectroscopic ellipsometry, which shows an increase in optical band gap energy (Eg) from 3.04 eV to 3.19 eV when the fluence increases to 2 × 1014 ions/cm2 and a decrease to 3 eV at fluence 5 × 1014 ions/cm2. We argue that these properties can be explained using ion heating effect of thin films.

  3. Solar Fuels and Carbon Cycle 2.0 (Carbon Cycle 2.0)

    ScienceCinema

    Alivisatos, Paul

    2011-06-03

    Paul Alivisatos, LBNL Director speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 4, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

  4. Carbon Cycle 2.0: Bill Collins: A future without CC2.0

    SciTech Connect

    Bill Collins

    2010-02-09

    Bill Collins speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 1, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

  5. Carbon Cycle 2.0: Bill Collins: A future without CC2.0

    ScienceCinema

    Bill Collins

    2010-09-01

    Bill Collins speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 1, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

  6. Magnetic moment of the 2083 keV level of 140Ce

    NASA Astrophysics Data System (ADS)

    Ohkubo, Y.; Taniguchi, A.; Xu, Q.; Tanigaki, M.; Shimizu, N.; Otsuka, T.

    2013-04-01

    For the magnetic moment of the 2083 keV level of 140Ce, there are four published data, all obtained by applying an external magnetic field of less than 5 T to a liquid sample containing 140La using the time-differential perturbed angular correlation (TDPAC) technique. Although these four values are consistent within two times their uncertainties (2σ), the range of values in 2σ extends from μ=+3.0 to +5.2 (in units of nuclear magneton, μN). This time, the TDPAC technique was successfully applied to the 2083 keV level of 140Ce implanted in an Fe foil. The magnetic moment of this level was determined to be μ=+4.00(20)μN, employing the known hyperfine field at 141Ce in Fe, -41(2) T, which agrees very well with one of the values, μ=+4.06(15)μN. The present value is compared with two shell-model calculations.

  7. Characterization of the PILATUS photon-counting pixel detector for X-ray energies from 1.75 keV to 60 keV

    NASA Astrophysics Data System (ADS)

    Donath, T.; Brandstetter, S.; Cibik, L.; Commichau, S.; Hofer, P.; Krumrey, M.; Lüthi, B.; Marggraf, S.; Müller, P.; Schneebeli, M.; Schulze-Briese, C.; Wernecke, J.

    2013-03-01

    The PILATUS detector module was characterized in the PTB laboratory at BESSY II comparing modules with 320 μm thick and newly developed 450 μm and 1000 μm thick silicon sensors. Measurements were carried out over a wide energy range, in-vacuum from 1.75 keV to 8.8 keV and in air from 8 keV to 60 keV. The quantum efficiency (QE) was measured as a function of energy and the spatial resolution was measured at several photon energies both in terms of the modulation transfer function (MTF) from edge profile measurements and by directly measuring the point spread function (PSF) of a single pixel in a raster scan with a pinhole beam. Independent of the sensor thickness, the measured MTF and PSF come close to those for an ideal pixel detector with the pixel size of the PILATUS detector (172 × 172 μm2). The measured QE follows the values predicted by calculation. Thicker sensors significantly enhance the QE of the PILATUS detectors for energies above 10 keV without impairing the spatial resolution and noise-free detection. In-vacuum operation of the PILATUS detector is possible at energies as low as 1.75 keV.

  8. Universal MOSFET gate impedance model for 200 MHz-20 GHz frequency range

    NASA Astrophysics Data System (ADS)

    Bandi, Sri Priya R.; Washburn, Clyde; Mukund, P. R.; Kolnik, Jan; Paradis, Ken; Howard, Steve; Burleson, Jeff

    2006-07-01

    The scaling of CMOS technology to 100 nm and below and the endless pursuit of higher operating frequencies drives the need to accurately model effects such as gate leakage and the deterioration of transport characteristics that dominate at those feature sizes and frequencies. Current modeling techniques are frequency limited and require different models for different frequency ranges in order to achieve accuracy goals. In the foundry world, high frequency models are typically empirical in nature and significantly lag their low frequency counterparts in terms of availability. This tends to slow the adoption of new foundry technologies for high performance applications such as extremely high data rate serializer/deserializer (SERDES) transceiver cores. However, design cycle time and time to market while transitioning between technology nodes can be reduced by incorporating a re-usable, industry-standard model. This work proposes such a model for device gate impedance that is simulator-friendly, compact, frequency-independent, and relatively portable across technology nodes. This semi-empirical gate impedance model is based on depletion in the poly-silicon gate electrode. The model performs accurately over 200 MHz-20 GHz at different bias conditions and widths and has been verified by measured data in three technology nodes. The model and model parameter behavior are consistent across technology nodes thereby enabling re-usability and portability.

  9. Measurements of total cross sections of the n = 2 excitation of helium from the impact of 10--25 keV protons

    NASA Astrophysics Data System (ADS)

    Hodges, Gregory Scott

    Absolute, total cross sections of n = 2 excitation of helium by intermediate-energy proton impact are determined using the energy-loss experimental method. The incident proton beam is accelerated to kinetic energies of 10-25 keV, and is focused into a target cell containing helium gas at room temperature. A hemispherical energy analyzer is used to measure energy-loss spectra of the incident and scattered proton beams. The excitation cross sections are determined by the measurement of the energy-loss peaks corresponding to excitation of the n = 2 states of helium. A deconvolution technique is applied to each spectrum to obtain the 21S, 2 1P, and n = 2 excitation cross section values. The present cross sections are compared to theoretical predictions which utilized the First and Second Born Approximation, the Distorted Wave Born Approximation, the Glauber Approximation, the Vainshtein-Presnyakov-Sobelman Approximation (VPSA), and the Multistate Impact Parameter Approximation (MSIPA) methods. The theoretical models that incorporate coupling of many states in the calculation, such as the MSIPA, are in reasonable agreement with the present data, suggesting that strong coupling between states must be considered in intermediate-energy, multi-electron ion-target collision systems.

  10. Electronic Alignment of HYDROGEN(2P) from Oriented Excited State Dihydrogen Cation Produced in 4.0 KEV Dihydrogen Cation Collisions with Helium

    NASA Astrophysics Data System (ADS)

    Calabrese, Dominic

    The electronic alignment of H(2p) from oriented (H{2}{+})^ {*} produced in 4.0 keV H {2}{+} collisions with helium is investigated for a variety of center-of-mass energies of the fragment particles. The experiment is performed by measuring the polarization of L_alpha in coincidence with the charged particle scattered at a specific laboratory scattering angle. The laboratory scattering angle and the laboratory energy of the charged particle not only specifies the instantaneous orientation of the parent molecule relative to the incident beam velocity, but also the center-of-mass energy of the fragment particles. Photon and proton detection systems were specially designed and implemented to increase data collection efficiency. This was important because of the time-consuming nature of the photon-particle coincidence method. In special cases, symmetry arguments for the collision system are employed in order to qualitatively assess and predict the characteristics of the nascent charge cloud. These arguments also help one to qualitatively predict the possible symmetries of the excited states of the parent molecule. The results are discussed in order to determine the efficacy of existing models for the (HeH_2) ^+ complex.

  11. [Gastroenterology 2.0: useful resources for the gastroenterologist available on the Web 2.0].

    PubMed

    Curioso, Walter H; Proaño, Alvaro; Ruiz, Eloy F

    2011-01-01

    The term Web 2.0 refers to the use of Internet applications which enable the users to share, participate and collaborate together on information. The objective of this study is to check different applications that use Web 2.0, which could help the gastroenterologist in his daily practice. The applications that will be checked include: blogs, microblogging, RSS, podcasts, wikis and social networks. "Gastroenterology 2.0" represents the applications, services, and tools based on Web 2.0, which are of easy use and easily accessible - to consumers, patients, gastroenterologists and other health professionals, as well as researchers. Although several studies have shown the benefits these technologies have on the medical practice, it is necessary to conduct further studies to demonstrate the use of these applications on improving health. PMID:22086320

  12. UQTk version 2.0 user manual.

    SciTech Connect

    Debusschere, Bert J.; Sargsyan, Khachik; Safta, Cosmin

    2013-10-01

    The UQ Toolkit (UQTk) is a collection of libraries and tools for the quanti cation of uncer- tainty in numerical model predictions. Version 2.0 o ers intrusive and non-intrusive methods for propagating input uncertainties through computational models, tools for sensitivity anal- ysis, methods for sparse surrogate construction, and Bayesian inference tools for inferring parameters from experimental data. This manual discusses the download and installation process for UQTk, provides pointers to the UQ methods used in the toolkit, and describes some of the examples provided with the toolkit.

  13. Energy dependent response of the Fricke gel dosimeter prepared with 270 Bloom gelatine for photons in the energy range 13.93 keV-6 MeV

    NASA Astrophysics Data System (ADS)

    Cavinato, C. C.; Campos, L. L.

    2010-07-01

    The spectrophotometric energy dependent response to photons with effective energies between 13.93 keV and 6 MeV of the Fricke xylenol gel (FXG) dosimeter developed at IPEN, prepared using 270 Bloom gelatine, was evaluated in order to verify the possible dosimeter application in other medicine areas in addition to radiosurgery, for example, breast radiotherapy and blood bags radiosterilization. Other dosimetric characteristics were also evaluated. The obtained results indicate that the FXG dosimeter can contribute to dosimetry in different medical application areas including magnetic resonance imaging (MRI) evaluation technique that permits three-dimensional (3D) dose distribution evaluation.

  14. Energy dependence and dose response of Gafchromic EBT2 film over a wide range of photon, electron, and proton beam energies

    SciTech Connect

    Arjomandy, Bijan; Tailor, Ramesh; Anand, Aman; Sahoo, Narayan; Gillin, Michael; Prado, Karl; Vicic, Milos

    2010-05-15

    Purpose: Since the Gafchromic film EBT has been recently replaced by the newer model EBT2, its characterization, especially energy dependence, has become critically important. The energy dependence of the dose response of Gafchromic EBT2 film is evaluated for a broad range of energies from different radiation sources used in radiation therapy. Methods: The beams used for this study comprised of kilovoltage x rays (75, 125, and 250 kVp), {sup 137}Cs gamma (662 KeV), {sup 60}Co gamma (1.17-1.33 MeV), megavoltage x rays (6 and 18 MV), electron beams (6 and 20 MeV), and proton beams (100 and 250 MeV). The film's response to each of the above energies was measured over the dose range of 0.4-10 Gy, which corresponds to optical densities ranging from 0.05 to 0.74 for the film reader used. Results: The energy dependence of EBT2 was found to be relatively small within measurement uncertainties (1{sigma}={+-}4.5%) for all energies and modalities. Conclusion: For relative and absolute dosimetry of radiation therapy beams, the weak energy dependence of the EBT2 makes it most suitable for clinical use compared to other films.

  15. The 20 element HgI2 energy dispersive x ray array detector system

    NASA Astrophysics Data System (ADS)

    Iwanczyk, J. A.; Dorri, N.; Wang, M.; Szczebiot, R. W.; Dabrowski, A. J.; Hedman, B.; Hodgson, K. O.; Patt, B. E.

    1991-11-01

    This paper describes recent progress in the development of HgI2 energy dispersive x-ray detector arrays and associated miniaturized processing electronics for synchrotron radiation research applications. The experimental results with a 20 element array detector were obtained under realistic synchrotron beam conditions at SSRL. An energy resolution of 250 eV (FWHM) at 5.9 keV (Mn-K(sub a)) was achieved. Energy resolution and throughput measurements versus input count rate and energy of incoming radiation have been measured. Extended X-ray Absorption Fine Structure (EXAFS) spectra were taken from diluted samples simulating proteins with nickel.

  16. Launch vehicle effluent measurements during the August 20, 1977, Titan 3 launch at Air Force Eastern Test Range

    NASA Technical Reports Server (NTRS)

    Woods, D. C.; Bendura, R. J.; Wornom, D. E.

    1979-01-01

    Airborne effluent measurements within the launch cloud and visible and infrared measurements of cloud physical behavior are discussed. Airborne effluent measurements include concentrations of HCl, Cl2, NO, NOX, and particulates as a function of time during each sampling pass through the exhaust cloud. The particle size distribution was measured for each pass through the cloud. Mass concentration as a function of particle diameter was measured over the size range of 0.05- to 25 micron diameter, and particle number density was measured as a function of diameter over a size range of 0.5 to 7.5 micron. Effluent concentrations in the cloud ranged from about 30 ppm several minutes after launch to about 1 to 2 ppm at 100 minutes. Maximum Cl2 concentrations were about 40 to 55 ppb and by 20 minutes were less than 1.0 ppb. A tabulated listing of the airborne data is given in the appendix. Usable cloud imaging data were limited to the first 16 minutes after launch.

  17. Variable Gap Undulator for 1.5-48 Kev Free Electron Laser at Linac Coherent Light Source

    SciTech Connect

    Pellegrini, C.; Wu, J.; /SLAC

    2011-08-17

    We study the feasibility of generating femtosecond duration Free-Electron Laser with a variable photon energy from 1.5 to 48 keV, using an electron bunch with the same characteristics of the LINAC Coherent Light Source (LCLS) bunch, and a planar undulator with additional focusing. We assume that the electron bunch energy can be changed, and the undulator has a variable gap, allowing a variable undulator parameter. It is assumed to be operated in an ultra-low charge and ultra-short pulse regime. We study the feasibility of a tunable, short pulse, X-ray FEL with photon energy from 1.5 to 48 keV, using an electron beam like the one in the LCLS and a 2:5 cm period, variable gap, planar undulator. The beam energy changes from 4.6 to 13.8 GeV, the electorn charge is kept at 10 pC, and the undulator parameter varies from 1 to 3. The undulator length needed to saturate the 48 keV FEL is about 55 m, with a peak power around 5 GW. At longer wavelength the saturation length is as short as 15 m, and the peak power around 20 GW. The results from the analytical models and the GENESIS simulations show that the system is feasible. The large wavelength range, full tunability and short, few femtosecond pulses, together with the large peak power, would provide a powerful research tool.

  18. A Call to Action: Carbon Cycle 2.0 (Carbon Cycle 2.0)

    ScienceCinema

    Alivisatos, Paul

    2011-06-08

    Berkeley Lab Director Paul Alivisatos speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 1, 2010. Humanity emits more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences.Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

  19. A Call to Action: Carbon Cycle 2.0 (Carbon Cycle 2.0)

    SciTech Connect

    Alivisatos, Paul

    2010-02-01

    Berkeley Lab Director Paul Alivisatos speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 1, 2010. Humanity emits more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences.Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

  20. A Future with (out) Carbon Cycle 2.0 (Carbon Cycle 2.0)

    ScienceCinema

    Collins, Bill

    2011-06-08

    Bill Collins, Head of LBNL's Climate Sciences Department, speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 1, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

  1. FLEXAN (version 2.0) user's guide

    NASA Technical Reports Server (NTRS)

    Stallcup, Scott S.

    1989-01-01

    The FLEXAN (Flexible Animation) computer program, Version 2.0 is described. FLEXAN animates 3-D wireframe structural dynamics on the Evans and Sutherland PS300 graphics workstation with a VAX/VMS host computer. Animation options include: unconstrained vibrational modes, mode time histories (multiple modes), delta time histories (modal and/or nonmodal deformations), color time histories (elements of the structure change colors through time), and rotational time histories (parts of the structure rotate through time). Concurrent color, mode, delta, and rotation, time history animations are supported. FLEXAN does not model structures or calculate the dynamics of structures; it only animates data from other computer programs. FLEXAN was developed to aid in the study of the structural dynamics of spacecraft.

  2. New space research frequency band proposals in the 20- to 40.5-GHz range

    NASA Technical Reports Server (NTRS)

    Bishop, D. F.

    1991-01-01

    Future space research communications systems may require spectra above 20 GHz. Frequency bands above 20 GHz are identified that are suitable for space research. The selection of the proper bands depends on consideration of interference with other radio services, adequate bandwidths, link performance, and technical requirements for practical implementation.

  3. BSD Portals for LINUX 2.0

    NASA Technical Reports Server (NTRS)

    McNab, A. David; woo, Alex (Technical Monitor)

    1999-01-01

    Portals, an experimental feature of 4.4BSD, extend the file system name space by exporting certain open () requests to a user-space daemon. A portal daemon is mounted into the file name space as if it were a standard file system. When the kernel resolves a pathname and encounters a portal mount point, the remainder of the path is passed to the portal daemon. Depending on the portal "pathname" and the daemon's configuration, some type of open (2) is performed. The resulting file descriptor is passed back to the kernel which eventually returns it to the user, to whom it appears that a "normal" open has occurred. A proxy portalfs file system is responsible for kernel interaction with the daemon. The overall effect is that the portal daemon performs an open (2) on behalf of the kernel, possibly hiding substantial complexity from the calling process. One particularly useful application is implementing a connection service that allows simple scripts to open network sockets. This paper describes the implementation of portals for LINUX 2.0.

  4. Width of the 511 keV line from the bulge of the galaxy

    SciTech Connect

    Zhitnitsky, Ariel

    2007-11-15

    In this paper I present the detail estimations for the width of the 511 keV line produced by a mechanism when dark matter is represented by macroscopically large dense nuggets. I argue that the width of 511 keV emission in this mechanism is very narrow (in a few keV range) in agreement with all observations. The dominant mechanism of the annihilation in this case is the positronium formation e{sup +}e{sup -}{yields}{sup 1}S{sub 0}{yields}2{gamma} rather than a direct e{sup +}e{sup -}{yields}2{gamma} annihilation. I also discuss some generic features of the {gamma} rays spectrum (in few MeV range) resulting from this mechanism.

  5. 2. GENERAL VIEW OF BRIDGE FROM ROADBED WITH 4' RANGE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. GENERAL VIEW OF BRIDGE FROM ROADBED WITH 4' RANGE POLE NEAR NORTHWEST CORNER OF BRIDGE, LOOKING SOUTH - North Fork Bridge, Spans North Fork of White River at State Highway 5, Norfork, Baxter County, AR

  6. Web 2.0 and Critical Information Literacy

    ERIC Educational Resources Information Center

    Dunaway, Michelle

    2011-01-01

    The impact of Web 2.0 upon culture, education, and knowledge is obfuscated by the pervasiveness of Web 2.0 applications and technologies. Web 2.0 is commonly conceptualized in terms of the tools that it makes possible, such as Facebook, Twitter, and Wikipedia. In the context of information literacy instruction, Web 2.0 is frequently conceptualized…

  7. 36 CFR 222.2 - Management of the range environment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 2 2013-07-01 2013-07-01 false Management of the range environment. 222.2 Section 222.2 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE... environment. (a) Allotments will be designated on the National Forest System and on other lands under...

  8. 36 CFR 222.2 - Management of the range environment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 2 2014-07-01 2014-07-01 false Management of the range environment. 222.2 Section 222.2 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE... environment. (a) Allotments will be designated on the National Forest System and on other lands under...

  9. 36 CFR 222.2 - Management of the range environment.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 2 2012-07-01 2012-07-01 false Management of the range environment. 222.2 Section 222.2 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE... environment. (a) Allotments will be designated on the National Forest System and on other lands under...

  10. 36 CFR 222.2 - Management of the range environment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Management of the range environment. 222.2 Section 222.2 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE... environment. (a) Allotments will be designated on the National Forest System and on other lands under...

  11. 36 CFR 222.2 - Management of the range environment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 2 2011-07-01 2011-07-01 false Management of the range environment. 222.2 Section 222.2 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE... environment. (a) Allotments will be designated on the National Forest System and on other lands under...

  12. GlidCop® DSC properties in the temperature range of 20-350°C

    NASA Astrophysics Data System (ADS)

    Solomon, Ronald R.; Troxell, Jack D.; Nadkarni, Anil V.

    1996-10-01

    GlidCop® AL-25 LOX-80 grade plates manufactured by processes relevant to ITER first wall copper alloy requirements were tested in the temperature range of 20-350°C. Plate manufacturing methods included hot isotatic pressing (HIP), extrusion (EXT), and extrusion followed by cross-rolling (EXT + XROLL). Tests that were performed included tensile, fracture toughness, impact toughness, and creep. The EXT + XROLL plate was found to have higher total elongation, reduction of area, and fracture toughness values than the EXT and HIP plates. All three processes had similar ultimate tensile and 0.2% yield strengths. The HIP material exhibited a lower creep rate than EXT + XROLL. The EXT and the EXT + XROLL plates had similar impact toughness values, which were higher than the HIP plate. Overall, the EXT + XROLL plate had the best combination of properties of the three processes examined.

  13. NATIONAL WATER POLLUTION CONTROL ASSESSMENT MODEL, VERSION 2.0 (NWPCAM 2.0)

    EPA Science Inventory

    NWPCAM 2.0 is a national-level water quality modeling system that can be used to simulate the water quality changes and economic benefits that result from various pollution control policies. It builds and significantly improves on an earlier model the Clean Water Act Effects Mode...

  14. Enabling Problem Based Learning through Web 2.0 Technologies: PBL 2.0

    ERIC Educational Resources Information Center

    Tambouris, Efthimios; Panopoulou, Eleni; Tarabanis, Konstantinos; Ryberg, Thomas; Buus, Lillian; Peristeras, Vassilios; Lee, Deirdre; Porwol, Lukasz

    2012-01-01

    Advances in Information and Communications Technology (ICT), particularly the so-called Web 2.0, are affecting all aspects of our life: How we communicate, how we shop, how we socialise, how we learn. Facilitating learning through the use of ICT, also known as eLearning, is a vital part of modern educational systems. Established pedagogical…

  15. Oh! Web 2.0, Virtual Reference Service 2.0, Tools & Techniques (II)

    ERIC Educational Resources Information Center

    Arya, Harsh Bardhan; Mishra, J. K.

    2012-01-01

    The paper describes the theory and definition of the practice of librarianship, specifically addressing how Web 2.0 technologies (tools) such as synchronous messaging, collaborative reference service and streaming media, blogs, wikis, social networks, social bookmarking tools, tagging, RSS feeds, and mashups might intimate changes and how…

  16. SOAP 2.0: Spot Oscillation And Planet 2.0

    NASA Astrophysics Data System (ADS)

    Dumusque, Xavier; Boisse, I.; Santos, N. C.

    2015-04-01

    SOAP (Spot Oscillation And Planet) 2.0 simulates the effects of dark spots and bright plages on the surface of a rotating star, computing their expected radial velocity and photometric signatures. It includes the convective blueshift and its inhibition in active regions.

  17. The SISAL 2.0 reference manual

    SciTech Connect

    Boehm, A.P.W.; Oldehoeft, R.R.; Cann, D.C.; Feo, J.T.

    1991-12-10

    In this report we describe the SISAL 2.0 programming language. The project began in 1982 as a cooperative venture by Digital Equipment Corporation, the University of Manchester (England), Lawrence Livermore National Laboratory, and Colorado State University. The project`s goals evolved to become: Define a general-purpose functional language that can run efficiently on conventional and novel parallel architectures; Define a dataflow graph intermediate form independent of language and target architecture; Develop optimization techniques for high-performance applicative computing; Develop a thread management environment to support dataflow-style parallel computing on conventional shared-memory multiprocessors; Achieve sequential and parallel execution performance competitive with program written in conventional languages; and Validate the functional style of programming for large-scale scientific applications. The last three goals set SISAL apart from other efforts. We have shown that the dataflow approach can profitably be applied outside the classic dataflow world, without the use of specialized hardware. SISAL runs on uniprocessors, shared-memory multiprocessors, the Cray-X/MP, the Warp systolic processor as well as Manchester`s dataflow machine. Development continues for the Connection Machine and some experimental systems.

  18. The Immune Epitope Database 2.0

    PubMed Central

    Vita, Randi; Zarebski, Laura; Greenbaum, Jason A.; Emami, Hussein; Hoof, Ilka; Salimi, Nima; Damle, Rohini; Sette, Alessandro; Peters, Bjoern

    2010-01-01

    The Immune Epitope Database (IEDB, www.iedb.org) provides a catalog of experimentally characterized B and T cell epitopes, as well as data on Major Histocompatibility Complex (MHC) binding and MHC ligand elution experiments. The database represents the molecular structures recognized by adaptive immune receptors and the experimental contexts in which these molecules were determined to be immune epitopes. Epitopes recognized in humans, nonhuman primates, rodents, pigs, cats and all other tested species are included. Both positive and negative experimental results are captured. Over the course of 4 years, the data from 180 978 experiments were curated manually from the literature, which covers ∼99% of all publicly available information on peptide epitopes mapped in infectious agents (excluding HIV) and 93% of those mapped in allergens. In addition, data that would otherwise be unavailable to the public from 129 186 experiments were submitted directly by investigators. The curation of epitopes related to autoimmunity is expected to be completed by the end of 2010. The database can be queried by epitope structure, source organism, MHC restriction, assay type or host organism, among other criteria. The database structure, as well as its querying, browsing and reporting interfaces, was completely redesigned for the IEDB 2.0 release, which became publicly available in early 2009. PMID:19906713

  19. 2 CFR 220.20 - Applicability.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... EDUCATIONAL INSTITUTIONS (OMB CIRCULAR A-21) § 220.20 Applicability. (a) All Federal agencies that sponsor research and development, training, and other work at educational institutions shall apply the provisions... CFR part 99....

  20. 2 CFR 225.20 - Policy.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... CIRCULARS AND GUIDANCE Reserved COST PRINCIPLES FOR STATE, LOCAL, AND INDIAN TRIBAL GOVERNMENTS (OMB CIRCULAR A-87) § 225.20 Policy. This part establishes principles and standards to provide a...

  1. GEM Building Taxonomy (Version 2.0)

    USGS Publications Warehouse

    Brzev, S.; Scawthorn, C.; Charleson, A.W.; Allen, L.; Greene, M.; Jaiswal, Kishor; Silva, V.

    2013-01-01

    /7/8/IRRE9/10/RSH3+RWO211/FW12/13/ which can be read as (1) Direction = [DX or DY] (the building has the same lateral load-resisting system in both directions); (2) Material = [Unreinforced Masonry + solid fired clay bricks + cement: lime mortar]; (3) Lateral Load-Resisting System = [Wall]; (4) Date of construction = [pre-1939]; (5) Heaight = [exactly 2 storeys]; (6) Occupancy = [residential, unknown type]; (7) Building Position = [unknown = no entry]; (8) Shape of building plan = [unknown = no entry]; (9) Structural irregularity = [regular]; (10) Exterior walls = [unknown = no entry]; (11) Roof = [Shape: pitched and hipped, Roof covering: clay tiles, Roof system material: wood, Roof system type: wood trusses]; (12) Floor = [Floor system: Wood, unknown]; (13) Foundation = [unknown = no entry]. Mapping of GEM Building Taxonomy to selected taxonomies is included in the report -- for example, the above building would be referenced by previous structural taxonomies as: PAGER-STR as UFB or UFB4, by the World Housing Encyclopedia as 7 or 8 and by the European Macroseismic Scale (98) as M5. The Building Taxonomy data model is highly flexible and has been incorporated within a relational database architecture. Due to its ability to represent building typologies using a shorthand form, it is also possible to use the taxonomy for non-database applications, and we discuss possible application of adaptation for Building Information Modelling (BIM) systems, and for the insurance industry. The GEM Building Taxonomy was independently evaluated and tested by the Earthquake Engineering Research Institute (EERI), which received 217 TaxT reports from 49 countries, representing a wide range of building typologies, including single and multi-storey buildings, reinforced and unreinforced masonry, confined masonry, concrete, steel, wood, and earthern buildings used for residential, commercial, industrial, and educational occupancy. Based on these submissions and other feedback, the EERI

  2. Evaluation of the 1077 keV γ-ray emission probability from 68Ga decay

    NASA Astrophysics Data System (ADS)

    Huang, Xiao-Long; Jiang, Li-Yang; Chen, Xiong-Jun; Chen, Guo-Chang

    2014-04-01

    68Ga decays to the excited states of 68Zn through the electron capture decay mode. New recommended values for the emission probability of 1077 keV γ-ray given by the ENSDF and DDEP databases all use data from absolute measurements. In 2011, JIANG Li-Yang deduced a new value for 1077 keV γ-ray emission probability by measuring the 69Ga(n,2n) 68Ga reaction cross section. The new value is about 20% lower than values obtained from previous absolute measurements and evaluations. In this paper, the discrepancies among the measurements and evaluations are analyzed carefully and the new values are re-recommended. Our recommended value for the emission probability of 1077 keV γ-ray is (2.72±0.16)%.

  3. Icosahedral short-range order in amorphous Cu80Si20 by ab initio molecular dynamics simulation study

    SciTech Connect

    Wu, S.; Kramer, Matthew J.; Fang, Xiaowei; Wang, Shy-Guey; Wang, Cai-Zhuang; Ho, Kai-Ming; Ding, Z.J.; Chen, L.Y.

    2012-04-26

    Short-range order in liquid and amorphous structures of Cu80Si20 is studied by ab initio molecular dynamics simulations. We performed the simulations at 1140 and 300 K respectively to investigate the local structure change from liquid to amorphous. The result of structure factor in comparison with experimental data indicates that our simulation of amorphous Cu80Si20 is reliable. By using the bond-angle distribution function, Honeycutt–Andersen index, Voronoi tessellation method, and the atomistic cluster alignment method, the icosahedral short-range order in the system is revealed. Strong Cu–Si interaction was also observed.

  4. The r-Java 2.0 code: nuclear physics

    NASA Astrophysics Data System (ADS)

    Kostka, M.; Koning, N.; Shand, Z.; Ouyed, R.; Jaikumar, P.

    2014-08-01

    Aims: We present r-Java 2.0, a nucleosynthesis code for open use that performs r-process calculations, along with a suite of other analysis tools. Methods: Equipped with a straightforward graphical user interface, r-Java 2.0 is capable of simulating nuclear statistical equilibrium (NSE), calculating r-process abundances for a wide range of input parameters and astrophysical environments, computing the mass fragmentation from neutron-induced fission and studying individual nucleosynthesis processes. Results: In this paper we discuss enhancements to this version of r-Java, especially the ability to solve the full reaction network. The sophisticated fission methodology incorporated in r-Java 2.0 that includes three fission channels (beta-delayed, neutron-induced, and spontaneous fission), along with computation of the mass fragmentation, is compared to the upper limit on mass fission approximation. The effects of including beta-delayed neutron emission on r-process yield is studied. The role of Coulomb interactions in NSE abundances is shown to be significant, supporting previous findings. A comparative analysis was undertaken during the development of r-Java 2.0 whereby we reproduced the results found in the literature from three other r-process codes. This code is capable of simulating the physical environment of the high-entropy wind around a proto-neutron star, the ejecta from a neutron star merger, or the relativistic ejecta from a quark nova. Likewise the users of r-Java 2.0 are given the freedom to define a custom environment. This software provides a platform for comparing proposed r-process sites.

  5. Efficient focusing of 8 keV X-rays with multilayer Fresnel zone plates fabricated by atomic layer deposition and focused ion beam milling.

    PubMed

    Mayer, Marcel; Keskinbora, Kahraman; Grévent, Corinne; Szeghalmi, Adriana; Knez, Mato; Weigand, Markus; Snigirev, Anatoly; Snigireva, Irina; Schütz, Gisela

    2013-05-01

    Fresnel zone plates (FZPs) recently showed significant improvement by focusing soft X-rays down to ~10 nm. In contrast to soft X-rays, generally a very high aspect ratio FZP is needed for efficient focusing of hard X-rays. Therefore, FZPs had limited success in the hard X-ray range owing to difficulties of manufacturing high-aspect-ratio zone plates using conventional techniques. Here, employing a method of fabrication based on atomic layer deposition (ALD) and focused ion beam (FIB) milling, FZPs with very high aspect ratios were prepared. Such multilayer FZPs with outermost zone widths of 10 and 35 nm and aspect ratios of up to 243 were tested for their focusing properties at 8 keV and shown to focus hard X-rays efficiently. This success was enabled by the outstanding layer quality thanks to ALD. Via the use of FIB for slicing the multilayer structures, desired aspect ratios could be obtained by precisely controlling the thickness. Experimental diffraction efficiencies of multilayer FZPs fabricated via this combination reached up to 15.58% at 8 keV. In addition, scanning transmission X-ray microscopy experiments at 1.5 keV were carried out using one of the multilayer FZPs and resolved a 60 nm feature size. Finally, the prospective of different material combinations with various outermost zone widths at 8 and 17 keV is discussed in the light of the coupled wave theory and the thin-grating approximation. Al2O3/Ir is outlined as a promising future material candidate for extremely high resolution with a theoretical efficiency of more than 20% for as small an outermost zone width as 10 nm at 17 keV. PMID:23592622

  6. Recent plant studies using Victoria 2.0

    SciTech Connect

    BIXLER,NATHAN E.; GASSER,RONALD D.

    2000-03-08

    VICTORIA 2.0 is a mechanistic computer code designed to analyze fission product behavior within the reactor coolant system (RCS) during a severe nuclear reactor accident. It provides detailed predictions of the release of radioactive and nonradioactive materials from the reactor core and transport and deposition of these materials within the RCS and secondary circuits. These predictions account for the chemical and aerosol processes that affect radionuclide behavior. VICTORIA 2.0 was released in early 1999; a new version VICTORIA 2.1, is now under development. The largest improvements in VICTORIA 2.1 are connected with the thermochemical database, which is being revised and expanded following the recommendations of a peer review. Three risk-significant severe accident sequences have recently been investigated using the VICTORIA 2.0 code. The focus here is on how various chemistry options affect the predictions. Additionally, the VICTORIA predictions are compared with ones made using the MELCOR code. The three sequences are a station blackout in a GE BWR and steam generator tube rupture (SGTR) and pump-seal LOCA sequences in a 3-loop Westinghouse PWR. These sequences cover a range of system pressures, from fully depressurized to full system pressure. The chief results of this study are the fission product fractions that are retained in the core, RCS, secondary, and containment and the fractions that are released into the environment.

  7. The Earth Satellite Program (ESP), version 2.0

    NASA Astrophysics Data System (ADS)

    Callwood, R.; Gaffney, L. M.

    1994-02-01

    The Earth Satellite Program (ESP) version 2.0 is a user-friendly, highly graphical, Macintosh-based program that was developed for the Air Force Milstar program to support satellite constellation and ground site terminal design studies. The computer program generates satellite ground tracks; computes elevation angles, ranges, and range rates; determines outage zones for a constellation of satellites; and generates spot beam projections. Any elliptical Earth-orbit may be accommodated. A fourth-order Runge-Kutta integrator is used to propagate satellite orbits. Perturbations due to the Earth's oblateness (J2 effects), atmospheric drag, and solar radiation pressure are included. This paper contains a user's guide to the program, presents the underlying mathematical models, and includes several sample outputs and the software on diskette.

  8. QuakeSim 2.0

    NASA Technical Reports Server (NTRS)

    Donnellan, Andrea; Parker, Jay W.; Lyzenga, Gregory A.; Granat, Robert A.; Norton, Charles D.; Rundle, John B.; Pierce, Marlon E.; Fox, Geoffrey C.; McLeod, Dennis; Ludwig, Lisa Grant

    2012-01-01

    QuakeSim 2.0 improves understanding of earthquake processes by providing modeling tools and integrating model applications and various heterogeneous data sources within a Web services environment. QuakeSim is a multisource, synergistic, data-intensive environment for modeling the behavior of earthquake faults individually, and as part of complex interacting systems. Remotely sensed geodetic data products may be explored, compared with faults and landscape features, mined by pattern analysis applications, and integrated with models and pattern analysis applications in a rich Web-based and visualization environment. Integration of heterogeneous data products with pattern informatics tools enables efficient development of models. Federated database components and visualization tools allow rapid exploration of large datasets, while pattern informatics enables identification of subtle, but important, features in large data sets. QuakeSim is valuable for earthquake investigations and modeling in its current state, and also serves as a prototype and nucleus for broader systems under development. The framework provides access to physics-based simulation tools that model the earthquake cycle and related crustal deformation. Spaceborne GPS and Inter ferometric Synthetic Aperture (InSAR) data provide information on near-term crustal deformation, while paleoseismic geologic data provide longerterm information on earthquake fault processes. These data sources are integrated into QuakeSim's QuakeTables database system, and are accessible by users or various model applications. UAVSAR repeat pass interferometry data products are added to the QuakeTables database, and are available through a browseable map interface or Representational State Transfer (REST) interfaces. Model applications can retrieve data from Quake Tables, or from third-party GPS velocity data services; alternatively, users can manually input parameters into the models. Pattern analysis of GPS and seismicity data

  9. Web 2.0 and health 2.0: are you in?

    PubMed

    Felkey, Bill G

    2008-01-01

    With over 6 billion web pages, over $100 billion in online sales every year in the U.S. alone and the average growth rate of online purchasing exceeding 26% over the last 5 years, the Internet is a powerful business tool. Today's shopper sees your actual pharmacy location and your Internet presence as one and the same. One study showed that 82% of the consumers surveyed who had a single frustrating experience online with a retailer would not return to the site for future dealings. A bad experience online made 28% of those surveyed unlikely to return to the retail location of the business, and over 55% said a bad online experience would have a negative impact on their overall opinion of the retailer. Web 2.0 refers to the social networking applications of the internet, Health 2.0 to its special health applications. Taking your Internet presence to the 2.0 level must be balanced with all of the other demands you are facing-but be aware that it's happening all around you. PMID:23969714

  10. Solar Advisor Model User Guide for Version 2.0

    SciTech Connect

    Gilman, P.; Blair, N.; Mehos, M.; Christensen, C.; Janzou, S.; Cameron, C.

    2008-08-01

    The Solar Advisor Model (SAM) provides a consistent framework for analyzing and comparing power system costs and performance across the range of solar technologies and markets, from photovoltaic systems for residential and commercial markets to concentrating solar power and large photovoltaic systems for utility markets. This manual describes Version 2.0 of the software, which can model photovoltaic and concentrating solar power technologies for electric applications for several markets. The current version of the Solar Advisor Model does not model solar heating and lighting technologies.

  11. SQUIRE 2.0 (Standards for QUality Improvement Reporting Excellence)

    PubMed Central

    Ogrinc, Greg; Davies, Louise; Goodman, Daisy; Batalden, Paul; Davidoff, Frank; Stevens, David

    2015-01-01

    In the past several years, the science of health care improvement has advanced considerably. In this article, we describe the development of SQUIRE 2.0 and its key components. We undertook the revision between 2012 and 2015 using (1) interviews and focus groups to evaluate SQUIRE 1.0 plus feedback from an international steering group, (2) face-to-face consensus meetings to develop interim drafts, and (3) pilot testing with authors and a public comment period. SQUIRE 2.0 emphasizes 3 key components of systematic efforts to improve the quality, value, and safety of health care: formal and informal theory in planning, implementing, and evaluating improvement work; the context in which the work is done; and the study of the intervention(s). SQUIRE 2.0 is intended for reporting the range of methods used to improve health care, recognizing that they can be complex and multidimensional. It provides common ground to share these discoveries in the scholarly literature (www.squire-statement.org). PMID:26497490

  12. Long-range intercellular Ca2+ wave patterns

    NASA Astrophysics Data System (ADS)

    Tabi, C. B.; Maïna, I.; Mohamadou, A.; Ekobena, H. P. F.; Kofané, T. C.

    2015-10-01

    Modulational instability is utilized to investigate intercellular Ca2+ wave propagation in an array of diffusively coupled cells. Cells are supposed to be connected via paracrine signaling, where long-range effects, due to the presence of extracellular messengers, are included. The multiple-scale expansion is used to show that the whole dynamics of Ca2+ waves, from the endoplasmic reticulum to the cytosol, can be reduced to a single differential-difference nonlinear equation whose solutions are assumed to be plane waves. Their linear stability analysis is studied, with emphasis on the impact of long-range coupling, via the range parameter s. It is shown that s, as well as the number of interacting cells, importantly modifies the features of modulational instability, as small values of s imply a strong coupling, and increasing its value rather reduces the problem to a first-neighbor one. Our theoretical findings are numerically tested, as the generic equations are fully integrated, leading to the emergence of nonlinear patterns of Ca2+ waves. Strong long-range coupling is pictured by extended trains of breather-like structures whose frequency decreases with increasing s. We also show numerically that the number of interacting cells plays on the spatio-temporal formation of Ca2+ patterns, whilst the quasi-perfect intercellular communication depends on the paracrine coupling parameter.

  13. Short-range correlations in carbon-12, oxygen-16, and neon-20: Intrinsic properties

    NASA Technical Reports Server (NTRS)

    Braley, R. C.; Ford, W. F.; Becker, R. L.; Patterson, M. R.

    1972-01-01

    The Brueckner-Hartree-Fock (BHF) method has been applied to nuclei whose intrinsic structure is nonspherical. Reaction matrix elements were calculated as functions of starting energy for the Hamada-Johnston interaction using the Pauli operator appropriate to O-16 and a shifted oscillator spectrum for virtual excited states. Binding energies, single particle energies, radii, and shape deformations of the intrinsic state, in ordinary as well as renormalized BHF, are discussed and compared with previous HF studies and with experiment when possible. Results are presented for C-12, 0-16 and Ne-20. It is found that the binding energies and radii are too small, but that separation energies are well reproduced when the renormalized theory is used.

  14. Ion-chain interaction in keV ion-beam-irradiated polystyrene

    SciTech Connect

    Calcagno, L.; Foti, G.; Licciardello, A.; Puglisi, O.

    1987-09-21

    Molecular weight distribution has been measured in monodisperse polystyrene film (MW = 9 000 amu) after ion bombardment, in the ion fluence range 10/sup 11/--10/sup 13/ ions/cm/sup 2/. The chosen beams are 100 keV He, 200 keV Ne, and 400 keV Ar. The experimental data have been interpreted in terms of a simple statistical model for cross-links. The chemical yield is found to be very high and equal to 0.30, about a factor of 10 higher than the values given in the literature for gamma irradiation (M. Dole, in The Radiation Chemistry of Macromolecules (Academic, New York, 1973), Vol. 2, Chap. 5, p. 57).

  15. Spatial distribution of upstream magnetospheric geq50 keV ions

    NASA Astrophysics Data System (ADS)

    Anagnostopoulos, G. C.; Argyropoulos, G.; Kaliabetsos, G.

    2000-01-01

    We present for the first time a statistical study of geq50 keV ion events of a magnetospheric origin upstream from Earth's bow shock. The statistical analysis of the 50-220 keV ion events observed by the IMP-8 spacecraft shows: (1) a dawn-dusk asymmetry in ion distributions, with most events and lower intensities upstream from the quasi-parallel pre-dawn side (4 LT-6 LT) of the bow shock, (2) highest ion fluxes upstream from the nose/dusk side of the bow shock under an almost radial interplanetary magnetic field (IMF) configuration, and (3) a positive correlation of the ion intensities with the solar wind speed and the index of geomagnetic index Kp, with an average solar wind speed as high as 620 km s-1 and values of the index Kp > 2. The statistical results are consistent with (1) preferential leakage of sim50 keV magnetospheric ions from the dusk magnetopause, (2) nearly scatter free motion of sim50 keV ions within the magnetosheath, and (3) final escape of magnetospheric ions from the quasi-parallel dawn side of the bow shock. An additional statistical analysis of higher energy (290-500 keV) upstream ion events also shows a dawn-dusk asymmetry in the occurrence frequency of these events, with the occurrence frequency ranging between sim16%-sim34% in the upstream region.

  16. sup 56 Fe resonance parameters for neutron energies up to 850 keV

    SciTech Connect

    Perey, C.M.; Perey, F.G.; Harvey, J.A.; Hill, N.W.; Larson, N.M.

    1990-12-01

    High-resolution neutron measurements for {sup 56}Fe-enriched iron targets were made at the Oak Ridge Electron Linear Accelerator (ORELA) in transmission below 20 MeV and in differential elastic scattering below 5 MeV. Transmission measurements were also performed with a natural iron target below 160 keV. The transmission data were analyzed from 5 to 850 keV with the multilevel R-matrix code SAMMY which uses Bayes' theorem for the fitting process. This code provides energies and neutron widths of the resonances inside the 5- to 850-keV energy region, as well as possible parameterization for resonances external to the analyzed region to describe the smooth cross section from a few eV to 850 keV. The resulting set of resonance parameters yields the accepted values for the thermal total and capture cross sections. The differential elastic-scattering data at several scattering angles were compared to theoretical calculations from 40 to 850 keV using the R-matrix code RFUNC based on the Blatt-Biedenharn formalism. Various combinations of spin and parity were tried to predict cross sections for the well defined {ell} > 0 resonances; comparison of these predictions with the data allowed us to determine the most likely spin and parity assignments for these resonances. The results of a capture data analysis by Corvi et al. (COR84), from 2 to 350 keV, were combined with our results to obtain the radiation widths of the resonances below 350 keV observed in transmission, capture, and differential elastic-scattering experiments.

  17. 26 CFR 20.2014-2 - “First limitation”.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 14 2014-04-01 2013-04-01 true âFirst limitationâ. 20.2014-2 Section 20.2014-2... respect to inheritance tax of son: ×$18,000 (factor B of the ratio stated at § 20.2014-2(a))= 12,000... ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 Credits Against Tax § 20.2014-2...

  18. 26 CFR 20.2014-2 - “First limitation”.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 14 2011-04-01 2010-04-01 true âFirst limitationâ. 20.2014-2 Section 20.2014-2... respect to inheritance tax of son: ×$18,000 (factor B of the ratio stated at § 20.2014-2(a))= 12,000... ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 Credits Against Tax § 20.2014-2...

  19. 26 CFR 20.2014-2 - “First limitation”.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 14 2013-04-01 2013-04-01 false âFirst limitationâ. 20.2014-2 Section 20.2014-2... respect to inheritance tax of son: ×$18,000 (factor B of the ratio stated at § 20.2014-2(a))= 12,000... ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 Credits Against Tax § 20.2014-2...

  20. 26 CFR 20.2014-2 - “First limitation”.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 14 2012-04-01 2012-04-01 false âFirst limitationâ. 20.2014-2 Section 20.2014-2... respect to inheritance tax of son: ×$18,000 (factor B of the ratio stated at § 20.2014-2(a))= 12,000... ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 Credits Against Tax § 20.2014-2...

  1. 26 CFR 20.2014-2 - “First limitation”.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 14 2010-04-01 2010-04-01 false âFirst limitationâ. 20.2014-2 Section 20.2014-2... respect to inheritance tax of son: ×$18,000 (factor B of the ratio stated at § 20.2014-2(a))= 12,000... ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 Credits Against Tax § 20.2014-2...

  2. Fragmentation of doubly charged HDO, H{sub 2}O, and D{sub 2}O molecules induced by proton and monocharged fluorine beam impact at 3 keV

    SciTech Connect

    Martin, S.; Chen, L.; Brédy, R.; Bernard, J.; Cassimi, A.

    2015-03-07

    Doubly charged ions HDO{sup 2+}, H{sub 2}O{sup 2+}, and D{sub 2}O{sup 2+} were prepared selectively to triplet or singlet excited states in collisions with F{sup +} or H{sup +} projectiles at 3 keV. Excitation energies of dications following two-body or three-body dissociation channels were measured and compared with recent calculations using ab initio multi-reference configuration interaction method [Gervais et al., J. Chem. Phys. 131, 024302 (2009)]. For HDO{sup 2+}, preferential cleavage of O–H rather than O–D bond has been observed and the ratio between the populations of the fragmentation channels OD{sup +}-H{sup +} and OH{sup +}-D{sup +} were measured. The kinetic energy release has been measured and compared with previous experiments.

  3. The 2-79 keV X-ray spectrum of the Circinus galaxy with NuSTAR, XMM-Newton, and Chandra: a fully Compton-thick active galactic nucleus

    SciTech Connect

    Arévalo, P.; Bauer, F. E.; Puccetti, S.; Walton, D. J.; Fuerst, F.; Grefenstette, B. W.; Harrison, F. A.; Madsen, K. K.; Koss, M.; Boggs, S. E.; Craig, W. W.; Brandt, W. N.; Luo, B.; Brightman, M.; Christensen, F. E.; Comastri, A.; Gandhi, P.; Hailey, C. J.; Madejski, G.; and others

    2014-08-20

    The Circinus galaxy is one of the closest obscured active galactic nuclei (AGNs), making it an ideal target for detailed study. Combining archival Chandra and XMM-Newton data with new NuSTAR observations, we model the 2-79 keV spectrum to constrain the primary AGN continuum and to derive physical parameters for the obscuring material. Chandra's high angular resolution allows a separation of nuclear and off-nuclear galactic emission. In the off-nuclear diffuse emission, we find signatures of strong cold reflection, including high equivalent-width neutral Fe lines. This Compton-scattered off-nuclear emission amounts to 18% of the nuclear flux in the Fe line region, but becomes comparable to the nuclear emission above 30 keV. The new analysis no longer supports a prominent transmitted AGN component in the observed band. We find that the nuclear spectrum is consistent with Compton scattering by an optically thick torus, where the intrinsic spectrum is a power law of photon index Γ = 2.2-2.4, the torus has an equatorial column density of N {sub H} = (6-10) × 10{sup 24} cm{sup –2}, and the intrinsic AGN 2-10 keV luminosity is (2.3-5.1) × 10{sup 42} erg s{sup –1}. These values place Circinus along the same relations as unobscured AGNs in accretion rate versus Γ and L{sub X} versus L {sub IR} phase space. NuSTAR's high sensitivity and low background allow us to study the short timescale variability of Circinus at X-ray energies above 10 keV for the first time. The lack of detected variability favors a Compton-thick absorber, in line with the spectral fitting results.

  4. The 2-79 keV X-Ray Spectrum of the Circinus Galaxy with NuSTAR, XMM-Newton, and Chandra: A Fully Compton-thick Active Galactic Nucleus

    NASA Astrophysics Data System (ADS)

    Arévalo, P.; Bauer, F. E.; Puccetti, S.; Walton, D. J.; Koss, M.; Boggs, S. E.; Brandt, W. N.; Brightman, M.; Christensen, F. E.; Comastri, A.; Craig, W. W.; Fuerst, F.; Gandhi, P.; Grefenstette, B. W.; Hailey, C. J.; Harrison, F. A.; Luo, B.; Madejski, G.; Madsen, K. K.; Marinucci, A.; Matt, G.; Saez, C.; Stern, D.; Stuhlinger, M.; Treister, E.; Urry, C. M.; Zhang, W. W.

    2014-08-01

    The Circinus galaxy is one of the closest obscured active galactic nuclei (AGNs), making it an ideal target for detailed study. Combining archival Chandra and XMM-Newton data with new NuSTAR observations, we model the 2-79 keV spectrum to constrain the primary AGN continuum and to derive physical parameters for the obscuring material. Chandra's high angular resolution allows a separation of nuclear and off-nuclear galactic emission. In the off-nuclear diffuse emission, we find signatures of strong cold reflection, including high equivalent-width neutral Fe lines. This Compton-scattered off-nuclear emission amounts to 18% of the nuclear flux in the Fe line region, but becomes comparable to the nuclear emission above 30 keV. The new analysis no longer supports a prominent transmitted AGN component in the observed band. We find that the nuclear spectrum is consistent with Compton scattering by an optically thick torus, where the intrinsic spectrum is a power law of photon index Γ = 2.2-2.4, the torus has an equatorial column density of N H = (6-10) × 1024 cm-2, and the intrinsic AGN 2-10 keV luminosity is (2.3-5.1) × 1042 erg s-1. These values place Circinus along the same relations as unobscured AGNs in accretion rate versus Γ and LX versus L IR phase space. NuSTAR's high sensitivity and low background allow us to study the short timescale variability of Circinus at X-ray energies above 10 keV for the first time. The lack of detected variability favors a Compton-thick absorber, in line with the spectral fitting results.

  5. 42 CFR 2.20 - Relationship to State laws.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Relationship to State laws. 2.20 Section 2.20 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS CONFIDENTIALITY OF ALCOHOL AND DRUG ABUSE PATIENT RECORDS General Provisions § 2.20 Relationship to State...

  6. 42 CFR 2.20 - Relationship to State laws.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Relationship to State laws. 2.20 Section 2.20 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS CONFIDENTIALITY OF ALCOHOL AND DRUG ABUSE PATIENT RECORDS General Provisions § 2.20 Relationship to State...

  7. 42 CFR 2.20 - Relationship to State laws.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Relationship to State laws. 2.20 Section 2.20... CONFIDENTIALITY OF ALCOHOL AND DRUG ABUSE PATIENT RECORDS General Provisions § 2.20 Relationship to State laws... the field of law which they cover to the exclusion of all State laws in that field. If a...

  8. 42 CFR 2.20 - Relationship to State laws.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Relationship to State laws. 2.20 Section 2.20... CONFIDENTIALITY OF ALCOHOL AND DRUG ABUSE PATIENT RECORDS General Provisions § 2.20 Relationship to State laws... the field of law which they cover to the exclusion of all State laws in that field. If a...

  9. 42 CFR 2.20 - Relationship to State laws.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Relationship to State laws. 2.20 Section 2.20... CONFIDENTIALITY OF ALCOHOL AND DRUG ABUSE PATIENT RECORDS General Provisions § 2.20 Relationship to State laws... the field of law which they cover to the exclusion of all State laws in that field. If a...

  10. Deriving a Typology of Web 2.0 Learning Technologies

    ERIC Educational Resources Information Center

    Bower, Matt

    2016-01-01

    This paper presents the methods and outcomes of a typological analysis of Web 2.0 technologies. A comprehensive review incorporating over 2000 links led to identification of over 200 Web 2.0 technologies that were suitable for learning and teaching purposes. The typological analysis involved development of relevant Web 2.0 dimensions, grouping…

  11. 46 CFR 2.20-40 - Chief engineer's reports.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Chief engineer's reports. 2.20-40 Section 2.20-40... INSPECTIONS Reports and Forms § 2.20-40 Chief engineer's reports. (a) Repairs to boilers and pressure vessels. The chief engineer is required to report any repairs to boilers or unfired pressure vessels...

  12. 46 CFR 2.20-40 - Chief engineer's reports.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Chief engineer's reports. 2.20-40 Section 2.20-40... INSPECTIONS Reports and Forms § 2.20-40 Chief engineer's reports. (a) Repairs to boilers and pressure vessels. The chief engineer is required to report any repairs to boilers or unfired pressure vessels...

  13. 46 CFR 2.20-40 - Chief engineer's reports.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Chief engineer's reports. 2.20-40 Section 2.20-40... INSPECTIONS Reports and Forms § 2.20-40 Chief engineer's reports. (a) Repairs to boilers and pressure vessels. The chief engineer is required to report any repairs to boilers or unfired pressure vessels...

  14. 46 CFR 2.20-40 - Chief engineer's reports.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Chief engineer's reports. 2.20-40 Section 2.20-40... INSPECTIONS Reports and Forms § 2.20-40 Chief engineer's reports. (a) Repairs to boilers and pressure vessels. The chief engineer is required to report any repairs to boilers or unfired pressure vessels...

  15. 46 CFR 2.20-40 - Chief engineer's reports.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Chief engineer's reports. 2.20-40 Section 2.20-40... INSPECTIONS Reports and Forms § 2.20-40 Chief engineer's reports. (a) Repairs to boilers and pressure vessels. The chief engineer is required to report any repairs to boilers or unfired pressure vessels...

  16. Exploring Library 2.0 on the Social Web

    ERIC Educational Resources Information Center

    Brantley, John S.

    2010-01-01

    Library 2.0 literature has described many of the possibilities Web 2.0 technologies offer to libraries. Case studies have assessed local use, but no studies have measured the Library 2.0 phenomenon by searching public social networking sites. This study used library-specific terms to search public social networking sites, blog search engines, and…

  17. Dynamic properties of Indiana, Fort Knox and Utah test range limestones and Danby Marble over the stress range 1 to 20 GPa

    SciTech Connect

    Furnish, M.D.

    1994-12-01

    The responses of the following carbonate materials to shock loading and release have been measured: Indiana limestone (18% porosity; saturated and dry), Jeffersonville/Louisville Limestones (Fort Knox limestone) (variable dolomitization, low porosity), Danby Marble (essentially pure calcite; low porosity), and a limestone from the Utah Test and Training Range (low porosity, with 22% silica). Various experimental configurations were used, some optimized to yield detailed waveform information, others to yield a clean combination of Hugoniot states and release paths. All made use of velocity interferometry as a primary diagnostic. The stress range of 0 - 20 GPa was probed (in most cases, emphasizing the stress range 0 -10 GPa). The primary physical processes observed in this stress regime were material strength, porosity, and polymorphic phase transitions between the CaCO{sub 3} phases I, II, III and VI. Hydration was also a significant reaction under certain conditions. The Indiana Limestone studies in particular represent a significant addition to the low-pressure database for porous limestone. Temperature dependence and the effect of freezing were assessed for the Fort Knox limestone. Experimental parameters and detailed results are provided for the 42 impact tests in this series.

  18. Angular dependence of L X-rays emission for Ag by 10 keV electron-impact

    NASA Astrophysics Data System (ADS)

    Wang, Xing; Xu, Zhongfeng; Zhang, Ying; Ma, Chao; Zhu, Chengwei

    2016-08-01

    The characteristic X-ray intensities of Ag-Lα, Lβ1, Lβ2 and Lγ1 are measured in electron-impact ionization at energy of 10 keV. The emission angle in this work ranges from 0° to 20° at interval of 5°. The angular dependence of L X-ray intensity ratios has been investigated for Lα / Lβ1, Lβ2 / Lβ1 and Lγ1 / Lβ1. It is found from the experimental results that the emissions of Lβ1, Lβ2 and Lγ1 X-rays are spatially isotropic, while the Lα X-rays exhibit anisotropic emission. Consequently, the alignment behavior of vacancy states is discussed with thorough analysis of vacancy transfer process.

  19. Cross section for induced L X-ray emission by protons of energy <400 keV

    NASA Astrophysics Data System (ADS)

    Mohan, Harsh; Jain, Arvind Kumar; Kaur, Mandeep; Singh, Parjit S.; Sharma, Sunita

    2014-08-01

    In performing ion beam analysis, cross section for induced L X-ray emission plays a crucial role. There are different approaches by which these can be found experimentally or can be calculated theoretically based on various models. L X-ray production cross sections for Bi with protons in the energy range 260-400 keV at the interval of 20 keV are measured. These are compared with calculations obtained on the basis of current prevailing theories ECPSSR and ECPSSR-UA. Their importance in understanding this phenomenon and existing arguments in this regard will be highlighted.

  20. Reaction mechanisms in the system {sup 20}Ne+{sup 165}Ho: Measurement and analysis of forward recoil range distributions

    SciTech Connect

    Singh, D.; Ali, R.; Ansari, M. Afzal; Rashid, M. H.; Guin, R.; Das, S. K.

    2009-05-15

    Keeping in view the study of complete and incomplete fusion of heavy ions with a target, the forward recoil range distributions of several evaporation residues produced at 164 MeV {sup 20}Ne-ion beam energy have been measured for the system {sup 20}Ne+{sup 165}Ho. The recoil catcher activation technique followed by off-line gamma spectroscopy has been employed. Measured forward recoil range distributions of these evaporation residues show evidence of several incomplete fusion channels in addition to complete fusion. The entire and partial linear momentum transfers inferred from these recoil range distributions were used to identify the evaporation residues formed by complete and incomplete fusion mechanisms. The results indicate the occurrence of incomplete fusion involving the breakup of {sup 20}Ne into {sup 4}He+{sup 16}O and/or {sup 8}Be+{sup 12}C followed by fusion of one of the fragments with target nucleus {sup 165}Ho. Complete and incomplete fusion reaction channels have been identified in the production of various evaporation residues and an attempt has been made to separate out relative contributions of complete and incomplete fusion components from the analysis of the measured recoil range distribution data. The total contribution of complete and incomplete fusion channels has also been estimated.

  1. Heliospheric Neutral Atom Spectra Between 0.01 and 6 keV fom IBEX

    NASA Technical Reports Server (NTRS)

    Fuselier, S. A.; Allegrini, F.; Bzowski, M.; Funsten, H. O.; Ghielmetti, A. G.; Gloeckler, G.; Heirtzler, D.; Janzen, P.; Kubiak, M.; Kucharek, H.; McComas, D. J.; Moebius, E.; Moore, T. E.; Petrinec, S. M.; Quinn, M.; Reisenfeld, D.; Saul, L. A.; Scheer, J. A.; Schwardron, N.; Trattner, K. J.; Vanderspek, R.; Wurz, P.

    2012-01-01

    Since 2008 December, the Interstellar Boundary Explorer (IBEX) has been making detailed observations of neutrals from the boundaries of the heliosphere using two neutral atom cameras with overlapping energy ranges. The unexpected, yet defining feature discovered by IBEX is a Ribbon that extends over the energy range from about 0.2 to 6 keV. This Ribbon is superposed on a more uniform, globally distributed heliospheric neutral population. With some important exceptions, the focus of early IBEX studies has been on neutral atoms with energies greater than approx. 0.5 keV. With nearly three years of science observations, enough low-energy neutral atom measurements have been accumulated to extend IBEX observations to energies less than approx. 0.5 keV. Using the energy overlap of the sensors to identify and remove backgrounds, energy spectra over the entire IBEX energy range are produced. However, contributions by interstellar neutrals to the energy spectrum below 0.2 keV may not be completely removed. Compared with spectra at higher energies, neutral atom spectra at lower energies do not vary much from location to location in the sky, including in the direction of the IBEX Ribbon. Neutral fluxes are used to show that low energy ions contribute approximately the same thermal pressure as higher energy ions in the heliosheath. However, contributions to the dynamic pressure are very high unless there is, for example, turbulence in the heliosheath with fluctuations of the order of 50-100 km/s.

  2. 2 CFR 230.20 - Applicability.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... to a college or university, 2 CFR part 220 shall apply; if a subaward is to a State, local, or federally-recognized Indian tribal government, 2 CFR part 225 shall apply. (c) Exclusion of some non-profit... and Agreements OFFICE OF MANAGEMENT AND BUDGET CIRCULARS AND GUIDANCE Reserved COST PRINCIPLES FOR...

  3. 20 CFR 302.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... tax base under section 3231(e)(2) of the Internal Revenue Code for the calendar year for which the... EMPLOYEE § 302.2 Definitions. Base year. The term “base year” means the completed calendar year immediately... monthly compensation base for that month and also excluding payments of the character described in §...

  4. 2 CFR 230.20 - Applicability.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... principles applicable to commercial concerns shall apply; if a subaward is to a college or university, 2 CFR... government, 2 CFR part 225 shall apply. (c) Exclusion of some non-profit organizations. Some non-profit... AND BUDGET CIRCULARS AND GUIDANCE Reserved COST PRINCIPLES FOR NON-PROFIT ORGANIZATIONS (OMB...

  5. 41 CFR 60-20.2 - Recruitment and advertisement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Recruitment and advertisement. 60-20.2 Section 60-20.2 Public Contracts and Property Management Other Provisions Relating to Public Contracts OFFICE OF FEDERAL CONTRACT COMPLIANCE PROGRAMS, EQUAL EMPLOYMENT OPPORTUNITY, DEPARTMENT OF LABOR 20-SEX DISCRIMINATION GUIDELINES...

  6. 30 CFR 20.9 - Class 2 lamps.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Class 2 lamps. 20.9 Section 20.9 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MINE LAMPS OTHER THAN STANDARD CAP LAMPS § 20.9 Class 2 lamps. (a) Safety. (1) Unless special features of the lamp...

  7. Prevention 2.0: targeting cyberbullying @ school.

    PubMed

    Wölfer, Ralf; Schultze-Krumbholz, Anja; Zagorscak, Pavle; Jäkel, Anne; Göbel, Kristin; Scheithauer, Herbert

    2014-12-01

    Although cyberbullying is characterized by worrying prevalence rates and associated with a broad range of detrimental consequences, there is a lack of scientifically based and evaluated preventive strategies. Therefore, the present study introduces a theory-based cyberbullying prevention program (Media Heroes; German original: Medienhelden) and evaluates its effectiveness. In a pretest-posttest design (9-month interval), schools were asked to randomly assign their participating classes to either control or intervention group. Longitudinal data were available from 593 middle school students (M Age = 13.3 years, 53 % girls) out of 35 classes, who provided information on cyberbullying behavior as well as socio-demographic and psychosocial variables. While the present results revealed worrying prevalence rates of cyberbullying in middle school, multilevel analyses clearly demonstrate the program's effectiveness in reducing cyberbullying behavior within intervention classes in contrast to classes of the control group. Hence, this study presents a promising program which evidentially prevents cyberbullying in schools. PMID:24122481

  8. Ellipsometry and energy characterization of the electron impact polymerization in the range 0-20 eV

    NASA Astrophysics Data System (ADS)

    Zyn, V. I.

    2016-05-01

    The electron impact polymerization of adsorbed vapors of a hydrocarbon vacuum oil with molecular mass 450 Da (C32H66) has been studied in-situ in the range 0-20 eV using ellipsometry and a servo system with the Kelvin's vibrating probe. This allowed registering at the same time the two energy-dependent characteristics (spectra) of the process: the film growth rate and the electrical potential of the irradiated surface. The first spectrum has two resonance maxima near 2.5 and 9.5 eV while the surface potential has only one weak extremum near 9.5 eV. The first growth rate peak at 2.5 eV was connected with a creation of radicals through a resonant process of the dissociative electron attachment and beginning polymerization. The peaks at 9.5 eV in both the spectra mean accelerating polymerization and decreasing surface charge owing to simultaneous birth of highly active radicals and free electrons. The single resonant process controlling both the processes simultaneously is the dissociative attachment of an electron to an anti-bonding molecular orbital, almost the same as at the 2.5 eV but differing by deeper decomposition of the transient anion, among the products of which are now not the radicals only but also free electrons. The kinetic curves obtained in pulsed regimes of the electron bombardment were qualitatively identical for different precursors and were used for calculations of cross sections of these processes.

  9. Spectral and spatial characteristics of x-ray film detectors in the wavelength range 20--150 {angstrom}

    SciTech Connect

    Fedin, D.A.; Fedorchuk, R.V.; Koshevoi, M.O.; Lukjantsev, I.V.; Rupasov, A.A.; Shikanov, A.S.; Gullikson, E.

    1995-12-31

    Investigations of spectral sensitivity, contrast coefficient, and spatial resolution of widely used x-ray films have been undertaken at the P.N. Lebedev Institute. A description of experimental methodologies and results are presented. These studies were carried out using synchrotron radiation in the range of 20--150 {angstrom}. Spectral sensitivity and contrast coefficient dependencies on wavelength for Kodak 10106, DEF, RAR2490, and TPF films and spatial resolution for Kodak 10106 and RAR2490 films are presented and discussed.

  10. 17 CFR 20.2 - Covered contracts.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...”) Cocoa. ICUS Coffee C. ICUS Cotton No. 2. ICUS Frozen Concentrated Orange Juice. ICUS Sugar No. 11. ICUS.... NYMEX Brent Financial. NYMEX Central Appalachian Coal. NYMEX Coffee. NYMEX Cotton. NYMEX Crude...

  11. Effects of the compounds 2-methoxynaphthoquinone, 2-propoxynaphthoquinone, and 2-isopropoxynaphthoquinone on ecdysone 20-monooxygenase activity.

    PubMed

    Mitchell, Martin J; Brescia, Aaron I; Smith, Stan L; Morgan, E David

    2007-09-01

    The effects of the natural compound 2-methoxy-1,4-naphthoquinone, isolated from the leaves of Impatiens glandulifera and the synthetic compounds 2-propoxy-1,4-naphthoquinone and 2-isopropoxy-1,4-naphthoquinone on ecdysone 20-monooxygenase (E-20-M) activity were examined in three insect species. Homogenates of wandering stage third instar larvae of Drosophila melanogaster, or abdomens from adult female Aedes aegypti, or fat body or midgut from fifth instar larvae of Manduca sexta were incubated with radiolabelled ecdysone and increasing concentrations (from 1 x 10(-8) to 1 x 10(-3) M) of the three compounds. All three compounds were found to inhibit in a dose-dependent fashion the E-20-M activity in the three insect species. The concentration of these compounds required to elicit a 50% inhibition of this steroid hydroxylase activity in the three insect species examined ranged from approximately 3 x 10(-5) to 7 x 10(-4) M. PMID:17694563

  12. 20 CFR 902.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... request; or (3) The need for consultation, which shall be conducted with all practicable speed, with... need to search for and collect the requested records from other establishments that are separate from the Joint Board's office processing the request; (2) The need to search for, collect,...

  13. 20 CFR 902.2 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... request; or (3) The need for consultation, which shall be conducted with all practicable speed, with... need to search for and collect the requested records from other establishments that are separate from the Joint Board's office processing the request; (2) The need to search for, collect,...

  14. 20 CFR 902.2 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... request; or (3) The need for consultation, which shall be conducted with all practicable speed, with... need to search for and collect the requested records from other establishments that are separate from the Joint Board's office processing the request; (2) The need to search for, collect,...

  15. The EUROCALL Review, Volume 20, Number 2

    ERIC Educational Resources Information Center

    Gimeno, Ana, Ed.

    2012-01-01

    "The EUROCALL Review" is published online biannually by the European Association for Computer-Assisted Language Learning (EUROCALL). This issue offers regular sections on: (1) up-to-date information on Special Interest Groups; (2) reports on on-going CALL or CALL-related R&D projects in which EUROCALL members participate; (3) reports and reviews…

  16. 20 CFR 604.2 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Social Security Act, 42 U.S.C. 501 et seq. (d) State means a State of the United States of America, the...' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR REGULATIONS FOR ELIGIBILITY FOR UNEMPLOYMENT COMPENSATION § 604.2 Definitions. (a) Department means the United States Department of Labor....

  17. 20 CFR 703.2 - Forms.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR LONGSHOREMEN'S AND HARBOR WORKERS' COMPENSATION ACT AND RELATED STATUTES INSURANCE REGULATIONS General § 703.2 Forms. (a) Any information required... section are available for public inspection at the Office of Workers' Compensation Programs,...

  18. 20 CFR 703.2 - Forms.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR LONGSHOREMEN'S AND HARBOR WORKERS' COMPENSATION ACT AND RELATED STATUTES INSURANCE REGULATIONS General § 703.2 Forms. (a) Any information required... section are available for public inspection at the Office of Workers' Compensation Programs,...

  19. 20 CFR 703.2 - Forms.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR LONGSHOREMEN'S AND HARBOR WORKERS' COMPENSATION ACT AND RELATED STATUTES INSURANCE REGULATIONS General § 703.2 Forms. (a) Any information required... section are available for public inspection at the Office of Workers' Compensation Programs,...

  20. 20 CFR 295.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... DECREE OR COURT-APPROVED PROPERTY SETTLEMENT § 295.2 Definitions. As used in this part— Act means the... court order of such country. Court decree means a final decree of divorce, dissolution, annulment, or legal separation issued by a court (including a final decree or order modifying the terms of...

  1. Home Energy Saver v.2.0

    Energy Science and Technology Software Center (ESTSC)

    2008-09-01

    A web-based residential energy calculator. Provides customized estimates of residential energy use, energy bills, and CO2 emissions, based on building description information provided by the user. Energy use is estimated by end-use and device, using engineering models. Space heating and cooling use is based on the DOE-2.1E building simulation model. Other end-uses (water heating, appliances, lighting, and miscellaneous equipment) are based on engineering models developed by LBNL. Users can estimate their household carbon footprint andmore » compare it to average vaules for their neighborhood and other regions, displayed using the Google Maps API. Energy bills can be calculated using either average energy price data or actual utility tariffs (including time-of-use) contained in the LBNL Tariff Analysis Project (TAP). HES includes a link to the TAP energy bill calculator web service. The HES software also includes extensive default input data for required user inputs.« less

  2. Home Energy Saver v.2.0

    SciTech Connect

    Mills, Evan; Brown, Richard; Pinckard, Maggie; Warner, Jeff

    2008-09-01

    A web-based residential energy calculator. Provides customized estimates of residential energy use, energy bills, and CO2 emissions, based on building description information provided by the user. Energy use is estimated by end-use and device, using engineering models. Space heating and cooling use is based on the DOE-2.1E building simulation model. Other end-uses (water heating, appliances, lighting, and miscellaneous equipment) are based on engineering models developed by LBNL. Users can estimate their household carbon footprint and compare it to average vaules for their neighborhood and other regions, displayed using the Google Maps API. Energy bills can be calculated using either average energy price data or actual utility tariffs (including time-of-use) contained in the LBNL Tariff Analysis Project (TAP). HES includes a link to the TAP energy bill calculator web service. The HES software also includes extensive default input data for required user inputs.

  3. Structural basis for receptor sharing and activation by interleukin-20 receptor-2 (IL-20R2) binding cytokines

    PubMed Central

    Logsdon, Naomi J.; Deshpande, Ashlesha; Harris, Bethany D.; Rajashankar, Kanagalaghatta R.; Walter, Mark R.

    2012-01-01

    Interleukin 20 (IL-20) is a pleotropic IL-10 family cytokine that protects epithelial surfaces from pathogens. However, dysregulated IL-20 signaling is implicated in several human pathologies including psoriasis, rheumatoid arthritis, atherosclerosis, and osteoporosis. IL-20, and related cytokines IL-19 and IL-24, designated IL-20 subfamily cytokines (IL-20SFCs), induce cellular responses through an IL-20R1/IL-20R2 (type I) receptor heterodimer, whereas IL-20 and IL-24 also signal through the IL-22R1/IL-20R2 (type II) receptor complex. The crystal structure of the IL-20/IL-20R1/IL-20R2 complex reveals how type I and II complexes discriminate cognate from noncognate ligands. The structure also defines how the receptor–cytokine interfaces are affinity tuned to allow distinct signaling through a receptor complex shared by three different ligands. Our results provide unique insights into the complexity of IL-20SFC signaling that may be critical in the design of mechanistic-based inhibitors of IL-20SFC–mediated inflammatory disease. PMID:22802649

  4. NASA Taxonomy 2.0 Project Overview

    NASA Technical Reports Server (NTRS)

    Dutra, Jayne; Busch, Joseph

    2004-01-01

    This viewgraph presentation reviews the project to develop a Taxonomy for NASA. The benefits of this project are: Make it easy for various audiences to find relevant information from NASA programs quickly, specifically (1) Provide easy access for NASA Web resources (2) Information integration for unified queries and management reporting ve search results targeted to user interests the ability to move content through the enterprise to where it is needed most (3) Facilitate Records Management and Retention Requirements. In addition the project will assist NASA in complying with E-Government Act of 2002 and prepare NASA to participate in federal projects.

  5. Storing keV negative ions for an hour: the lifetime of the metastable ^(2)P((1/2)^(o)) level in ^(32)S^(-).

    PubMed

    Bäckström, E; Hanstorp, D; Hole, O M; Kaminska, M; Nascimento, R F; Blom, M; Björkhage, M; Källberg, A; Löfgren, P; Reinhed, P; Rosén, S; Simonsson, A; Thomas, R D; Mannervik, S; Schmidt, H T; Cederquist, H

    2015-04-10

    We use a novel electrostatic ion storage ring to measure the radiative lifetime of the upper level in the 3p^{5} ^{2}P_{1/2}^{o}→3p^{5} ^{2}P_{3/2}^{o} spontaneous radiative decay in ^{32}S^{-} to be 503±54  sec. This is by orders of magnitude the longest lifetime ever measured in a negatively charged ion. Cryogenic cooling of the storage ring gives a residual-gas pressure of a few times 10^{-14} mbar at 13 K and storage of 10 keV sulfur anions for more than an hour. Our experimental results differ by 1.3σ from the only available theoretical prediction [P. Andersson et al., Phys. Rev. A 73, 032705 (2006)]. PMID:25910117

  6. BioCat 2.0

    SciTech Connect

    Corley, Courtney D.; Noonan, Christine F.; Bartholomew, Rachel A.; Franklin, Trisha L.; Hutchison, Janine R.; Lancaster, Mary J.; Madison, Michael C.; Piatt, Andrew W.

    2013-09-16

    The U.S. Department of Homeland Security (DHS) National Biosurveillance Integration Center (NBIC) was established in 2008 with a primary mission to “(1) enhance the capability of the Federal Government to (A) rapidly identify, characterize, localize, and track a biological event of national concern by integrating and analyzing data relating to human health, animal, plant, food, and environmental monitoring systems (both national and international); and (B) disseminate alerts and other information to Member Agencies and, in coordination with (and where possible through) Member Agencies, to agencies of State, local, and tribal governments, as appropriate, to enhance the ability of such agencies to respond to a biological event of national concern; and (2) oversee development and operation of the National Biosurveillance Integration System (NBIS).” Inherent in its mission then and the broader NBIS, NBIC is concerned with the identification, understanding, and use of a variety of biosurveillance models and systems. The goal of this project is to characterize, evaluate, classify, and catalog existing disease forecast and prediction models that could provide operational decision support for recognizing a biological event having a potentially significant impact. Additionally, gaps should be identified and recommendations made on using disease models in an operational environment to support real-time decision making.

  7. 26 CFR 20.0-2 - General description of tax.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 14 2014-04-01 2013-04-01 true General description of tax. 20.0-2 Section 20.0-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) ESTATE AND GIFT TAXES ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 Introduction § 20.0-2 General description of tax. (a) Nature of tax. The...

  8. 26 CFR 20.2013-2 - “First limitation”.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 14 2010-04-01 2010-04-01 false âFirst limitationâ. 20.2013-2 Section 20.2013-2... ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 Credits Against Tax § 20.2013-2 “First... transferor's estate is the “first limitation.” Thus, the credit is limited to an amount, A, which bears...

  9. 26 CFR 20.2013-2 - “First limitation”.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 14 2011-04-01 2010-04-01 true âFirst limitationâ. 20.2013-2 Section 20.2013-2... ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 Credits Against Tax § 20.2013-2 “First... transferor's estate is the “first limitation.” Thus, the credit is limited to an amount, A, which bears...

  10. 47 CFR 20.2 - Other applicable rule parts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Other applicable rule parts. 20.2 Section 20.2 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES COMMERCIAL MOBILE SERVICES... mobile radio services include the following: (a) Part 1. This part includes rules of practice...

  11. 47 CFR 20.2 - Other applicable rule parts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Other applicable rule parts. 20.2 Section 20.2 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES COMMERCIAL MOBILE SERVICES... mobile radio services include the following: (a) Part 1. This part includes rules of practice...

  12. Evaluating HDR photos using Web 2.0 technology

    NASA Astrophysics Data System (ADS)

    Qiu, Guoping; Mei, Yujie; Duan, Jiang

    2011-01-01

    High dynamic range (HDR) photography is an emerging technology that has the potential to dramatically enhance the visual quality and realism of digital photos. One of the key technical challenges of HDR photography is displaying HDR photos on conventional devices through tone mapping or dynamic range compression. Although many different tone mapping techniques have been developed in recent years, evaluating tone mapping operators prove to be extremely difficult. Web2.0, social media and crowd-sourcing are emerging Internet technologies which can be harnessed to harvest the brain power of the mass to solve difficult problems in science, engineering and businesses. Paired comparison is used in the scientific study of preferences and attitudes and has been shown to be capable of obtaining an interval-scale ordering of items along a psychometric dimension such as preference or importance. In this paper, we exploit these technologies for evaluating HDR tone mapping algorithms. We have developed a Web2.0 style system that enables Internet users from anywhere to evaluate tone mapped HDR photos at any time. We adopt a simple paired comparison protocol, Internet users are presented a pair of tone mapped images and are simply asked to select the one that they think is better or click a "no difference" button. These user inputs are collected in the web server and analyzed by a rank aggregation algorithm which ranks the tone mapped photos according to the votes they received. We present experimental results which demonstrate that the emerging Internet technologies can be exploited as a new paradigm for evaluating HDR tone mapping algorithms. The advantages of this approach include the potential of collecting large user inputs under a variety of viewing environments rather than limited user participation under controlled laboratory environments thus enabling more robust and reliable quality assessment. We also present data analysis to correlate user generated qualitative

  13. One-sided imaging of large, dense objects using the 511 keV photons from induced pair production

    SciTech Connect

    Tavora, L.M.; Gilboy, W.B.; Morton, E.J.; Morgado, R.E.; Estep, R.J.; Rawool-Sullivan, M.

    1998-03-01

    The use of annihilation photons from photon-induced electron-positron pair production as a means of inspecting objects when only one side is accessible is described. The Z2 dependence of the pair production cross section and the high penetration of 511 keV photons suggest that this method should be capable of localizing high Z materials in lower Z matrices. The experimental results for the dependence of the back streaming photon yield on Z indicate that dynamic ranges of the order of 20 may be obtained for materials with 4 < Z < 82. Results for point to point images obtained in line scans of representative geometries are also shown. Simulation studies based on the EGS4 Monte Carlo code were also performed and their results show an agreement with experimental data of the order of 5%.

  14. An electrically driven terahertz metamaterial diffractive modulator with more than 20 dB of dynamic range

    SciTech Connect

    Karl, N.; Reichel, K.; Mendis, R.; Mittleman, D. M.; Chen, H.-T.; Taylor, A. J.; Brener, I.; Benz, A.; Reno, J. L.

    2014-03-03

    We design and experimentally demonstrate a switchable diffraction grating for terahertz modulation based on planar active metamaterials, where a Schottky gate structure is implemented to tune the metamaterial resonances in real-time via the application of an external voltage bias. The diffraction grating is formed by grouping the active split-ring resonators into an array of independent columns with alternate columns biased. We observe off-axis diffraction over a wide frequency band in contrast to the narrow-band resonances, which permits operation of the device as a relatively high-speed, wide-bandwidth, high-contrast modulator, with more than 20 dB of dynamic range.

  15. Using Web 2.0 for health promotion and social marketing efforts: lessons learned from Web 2.0 experts.

    PubMed

    Dooley, Jennifer Allyson; Jones, Sandra C; Iverson, Don

    2014-01-01

    Web 2.0 experts working in social marketing participated in qualitative in-depth interviews. The research aimed to document the current state of Web 2.0 practice. Perceived strengths (such as the viral nature of Web 2.0) and weaknesses (such as the time consuming effort it took to learn new Web 2.0 platforms) existed when using Web 2.0 platforms for campaigns. Lessons learned were identified--namely, suggestions for engaging in specific types of content creation strategies (such as plain language and transparent communication practices). Findings present originality and value to practitioners working in social marketing who want to effectively use Web 2.0. PMID:24878406

  16. Reference range for uterine artery Doppler pulsatility index using transvaginal ultrasound at 20–24w6d of gestation in a low-risk Brazilian population

    PubMed Central

    Peixoto, Alberto Borges; Da Cunha Caldas, Taciana Mara Rodrigues; Tonni, Gabriele; De Almeida Morelli, Priscilla; Santos, Larissa D’amico; Martins, Wellington P.; Júnior, Edward Araujo

    2016-01-01

    Objective To establish reference range for uterine artery (UtA) Doppler pulsatility index (PI) using transvaginal ultrasound at 20–24w6d of gestation in a Brazilian population. Material and Methods A retrospective cross-sectional study in 847 low-risk pregnant women undergoing routine second trimester ultrasound examination was conducted from February 2012 through March 2015. The mean UtA PI was calculated using color Doppler ultrasound with UtA gated at the level of the internal os. Mean±standard deviation and ranges for UtA Doppler PI in relation to gestational age (GA) are reported. Polynomial regression was used to obtain the best fit using mean UtA Doppler PI and GA (weeks) with adjustments performed using determination coefficient (R2). The 5th, 50th, and 95th percentiles for the mean UtA Doppler PI in relation to GA were determined. Results The mean UtA Doppler PI ranged from 1.14 at 20 weeks to 0.95 at 24 weeks of gestation. The best-fit curve of mean UtA Doppler PI as a function of GA was a first-degree polynomial regression: mean UtA Doppler PI=1.900−0.038×GA (R2=0.01). Conclusion In summary, when the mean UtA PI Doppler values were measured by transvaginal ultrasound at 20–24w6d of gestation, decrease in UtA Doppler PI values with advancing GA was observed. Reference range for the mean UtA Doppler PI at 20–24w6d of gestation using the transvaginal ultrasound in a low-risk Brazilian population was established. We believe that this reference range may be of clinical value in daily obstetric practice. PMID:27026774

  17. New and Innovative Library Services: Moving with Web 2.0 / Library 2.0 Technology, a Case Study

    NASA Astrophysics Data System (ADS)

    Sahu, H. K.; Pathak, S. K.; Singh, S. N.

    2010-10-01

    We give an overview and definition of Web 2.0 and Library 2.0 technology, especially addressing how it changes access to collections for users. We also describe its unlimited possibilities. The various components of Library 2.0 viz blogs, wikis, RSS, instant messaging, social networking, podcasting, and tagging are briefly summarized. Initiatives at three special information centers and libraries (IUCAA — Astronomy and Astrophysics; IIT — Science and Technology; and NIV — Viral Diseases) are described. We conclude with a futuristic view of Library 2.0.

  18. 20 CFR 718.2 - Applicability of this part.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... C of part 727 of this subchapter (see 20 CFR 725.4(d)) cannot be approved under that subpart, such... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false Applicability of this part. 718.2 Section 718... OR DEATH DUE TO PNEUMOCONIOSIS General § 718.2 Applicability of this part. With the exception of...

  19. 20 CFR 718.2 - Applicability of this part.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... version of Part 718 set forth in 20 CFR, parts 500 to end, edition revised as of April 1, 2010, applies to... 20 Employees' Benefits 4 2014-04-01 2014-04-01 false Applicability of this part. 718.2 Section 718... OR DEATH DUE TO PNEUMOCONIOSIS General § 718.2 Applicability of this part. (a) With the exception...

  20. The Next Wave Now: Web 2.0

    ERIC Educational Resources Information Center

    Mills, Lane B.

    2007-01-01

    While many people are just getting comfortable with the Internet and e-mail, Web 2.0 technologies are already changing the playing field for education. Though definitions of Web 2.0 vary, the one constant is that Internet users are now content providers rather than content receivers. The top-down approach of the Web has been replaced with users…

  1. Web 2.0 Strategy in Libraries and Information Services

    ERIC Educational Resources Information Center

    Byrne, Alex

    2008-01-01

    Web 2.0 challenges libraries to change from their predominantly centralised service models with integrated library management systems at the hub. Implementation of Web 2.0 technologies and the accompanying attitudinal shifts will demand reconceptualisation of the nature of library and information service around a dynamic, ever changing, networked,…

  2. Ubiquitous Complete in a Web 2.0 World

    ERIC Educational Resources Information Center

    Bull, Glen; Ferster, Bill

    2006-01-01

    In the third wave of computing, people will interact with multiple computers in multiple ways in every setting. The value of ubiquitous computing is enhanced and reinforced by another trend: the transition to a Web 2.0 world. In a Web 2.0 world, applications and data reside on the Web itself. Schools are not yet approaching a ratio of one…

  3. Information Literacy Instruction in the Web 2.0 Library

    ERIC Educational Resources Information Center

    Humrickhouse, Elizabeth

    2011-01-01

    This paper examines how library educators can implement Web 2.0 tools in their Information Literacy programs to better prepare students for the rigors of academic research. Additionally, this paper looks at transliteracy and constructivism as the most useful teaching methods in a Web 2.0 classroom and attempts to pinpoint specific educational…

  4. Project WET Curriculum and Activity Guide 2.0

    ERIC Educational Resources Information Center

    Project WET Foundation, 2011

    2011-01-01

    The "Project WET Curriculum and Activity Guide 2.0" continues Project WET's dedication to 21st-century, cutting-edge water education. Now in full color, Guide 2.0 offers new activities on topics such as National Parks and storm water, fully revised and updated activities from the original Guide and the very best activities gathered from all of…

  5. Scenarios and Strategies for Web 2.0

    ERIC Educational Resources Information Center

    Martin, Graeme; Reddington, Martin; Kneafsey, Mary Beth; Sloman, Martyn

    2009-01-01

    Purpose: The aim of this article is to bring together ideas from the authors' review of the Web 2.0 literature, the data and their insights from this and other technology-related projects to produce a framework for strategies on Web 2.0 focusing on the implications for human resource professionals. Design/methodology/approach: The authors discuss…

  6. Unleashing the Power of Web 2.0

    ERIC Educational Resources Information Center

    Waters, John K.

    2008-01-01

    As Web 2.0 technologies impact the evolution of online learning, they are certain to blur the definitional lines between electronic portfolios and personal learning environments (PLEs). According to Gary Brown, director of Washington State University's Center for Teaching, Learning, and Technology, the Web 2.0 technologies that are emerging…

  7. 26 CFR 20.2053-2 - Deduction for funeral expenses.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 14 2013-04-01 2013-04-01 false Deduction for funeral expenses. 20.2053-2 Section 20.2053-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) ESTATE AND GIFT TAXES ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 Taxable Estate §...

  8. 26 CFR 20.2053-2 - Deduction for funeral expenses.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 14 2011-04-01 2010-04-01 true Deduction for funeral expenses. 20.2053-2 Section 20.2053-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) ESTATE AND GIFT TAXES ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 Taxable Estate §...

  9. 26 CFR 20.2053-2 - Deduction for funeral expenses.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 14 2012-04-01 2012-04-01 false Deduction for funeral expenses. 20.2053-2 Section 20.2053-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) ESTATE AND GIFT TAXES ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 Taxable Estate §...

  10. 26 CFR 20.2053-2 - Deduction for funeral expenses.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 14 2010-04-01 2010-04-01 false Deduction for funeral expenses. 20.2053-2 Section 20.2053-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) ESTATE AND GIFT TAXES ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 Taxable Estate §...

  11. 26 CFR 20.2053-2 - Deduction for funeral expenses.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 14 2014-04-01 2013-04-01 true Deduction for funeral expenses. 20.2053-2 Section 20.2053-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) ESTATE AND GIFT TAXES ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 Taxable Estate §...

  12. Students as Digital Citizens on Web 2.0

    ERIC Educational Resources Information Center

    Nebel, Michelle; Jamison, Barbara; Bennett, Linda

    2009-01-01

    Internet tools associated with Web 2.0 such as wikis, blogs, and video podcasts are increasingly available in elementary classrooms. ("Web 2.0" is a vaguely defined, folk-tech term that means, roughly, the Internet and all software and devices, constantly improving, that strive to exploit it in creative and useful ways.) Today, elementary students…

  13. A Framework for Web 2.0 Learning Design

    ERIC Educational Resources Information Center

    Bower, Matt; Hedberg, John G.; Kuswara, Andreas

    2010-01-01

    This paper describes an approach to conceptualising and performing Web 2.0-enabled learning design. Based on the Technological, Pedagogical and Content Knowledge model of educational practice, the approach conceptualises Web 2.0 learning design by relating Anderson and Krathwohl's Taxonomy of Learning, Teaching and Assessing, and different types…

  14. What You Need to Know about Web 2.0

    ERIC Educational Resources Information Center

    Imperatore, Catherine

    2009-01-01

    Also known as the read/write or participatory Web, Web 2.0 includes such tools as blogs, podcasts, forums, wikis and social networks. It gives users the ability to take in information and create, organize and connect with others interested in the same topics. Web 2.0 is revolutionizing education because students and educators can easily and…

  15. 26 CFR 20.7520-2 - Valuation of charitable interests.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 14 2010-04-01 2010-04-01 false Valuation of charitable interests. 20.7520-2... Valuations § 20.7520-2 Valuation of charitable interests. (a) In general—(1) Valuation. Except as otherwise... applicable section 7520 interest rate. If the executor elects the alternate valuation date under section...

  16. Changing Paradigms Managed Learning Environments and Web 2.0

    ERIC Educational Resources Information Center

    Craig, Emory M.

    2007-01-01

    Purpose: The purpose of this paper is to understand how emerging technologies and Web 2.0 services are transforming the structure of the web and their potential impact on managed learning environments (MLS) and learning content management systems (LCMS). Design/methodology/approach: Innovative Web 2.0 applications are reviewed in the paper to…

  17. 20 CFR 211.2 - Definition of compensation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Definition of compensation. 211.2 Section 211...: (1) Salary, wages and bonuses; (2) Pay for time lost as an employee; (3) Cash tips of $20 or more... prior to April 1, 1940, shall not be creditable as compensation in a month unless taxes with respect...

  18. 20 CFR 211.2 - Definition of compensation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Definition of compensation. 211.2 Section 211...: (1) Salary, wages and bonuses; (2) Pay for time lost as an employee; (3) Cash tips of $20 or more... prior to April 1, 1940, shall not be creditable as compensation in a month unless taxes with respect...

  19. Leadership 2.0: Social Media in Advocacy

    ERIC Educational Resources Information Center

    Gonzales, Lisa; Vodicka, Devin; White, John

    2011-01-01

    Technology is always changing, always improving, and always pushing the envelope for how one works in education. In this increasingly connected age, people have seen rapid growth in social network tools such as Twitter and Facebook. These sites are representative of Web 2.0 resources where users contribute content. Other examples of Web 2.0 sites…

  20. Web 2.0 in the Mathematics Classroom

    ERIC Educational Resources Information Center

    McCoy, Leah P.

    2014-01-01

    A key characteristic of successful mathematics teachers is that they are able to provide varied activities that promote student learning and assessment. Web 2.0 applications can provide an assortment of tools to help produce creative activities. A Web 2.0 tool enables the student to enter data and create multimedia products using text, graphics,…

  1. Web 2.0: Creating a Classroom without Walls

    ERIC Educational Resources Information Center

    Barlow, Tim

    2008-01-01

    This article is about my year-long journey implementing Web 2.0 tools into my teaching practice. The goal throughout my journey has always been to increase my students' intrinsic motivation to learn about science. The Web 2.0 tools I used along my journey were weblogs (blogs) and podcasts. (Contains 1 figure.)

  2. On Recommending Web 2.0 Tools to Personalise Learning

    ERIC Educational Resources Information Center

    Juškeviciene, Anita; Kurilovas, Eugenijus

    2014-01-01

    The paper aims to present research results on using Web 2.0 tools for learning personalisation. In the work, personalised Web 2.0 tools selection method is presented. This method takes into account student's learning preferences for content and communication modes tailored to the learning activities with a view to help the learner to quickly and…

  3. Raptor: An Enterprise Knowledge Discovery Engine Version 2.0

    Energy Science and Technology Software Center (ESTSC)

    2011-08-31

    The Raptor Version 2.0 computer code uses a set of documents as seed documents to recommend documents of interest from a large, target set of documents. The computer code provides results that show the recommended documents with the highest similarity to the seed documents. Version 2.0 was specifically developed to work with SharePoint 2007 and MS SQL server.

  4. 33 CFR 2.20 - Territorial sea baseline.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Territorial sea baseline. 2.20... JURISDICTION Jurisdictional Terms § 2.20 Territorial sea baseline. Territorial sea baseline means the line defining the shoreward extent of the territorial sea of the United States drawn according to the...

  5. 18 CFR 20.2 - Regulation of issuance of securities.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Regulation of issuance of securities. 20.2 Section 20.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... Regulation of issuance of securities. The licensee or other person issuing or proposing to issue any...

  6. 18 CFR 20.2 - Regulation of issuance of securities.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Regulation of issuance of securities. 20.2 Section 20.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... Regulation of issuance of securities. The licensee or other person issuing or proposing to issue any...

  7. 18 CFR 20.2 - Regulation of issuance of securities.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Regulation of issuance of securities. 20.2 Section 20.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... Regulation of issuance of securities. The licensee or other person issuing or proposing to issue any...

  8. 18 CFR 20.2 - Regulation of issuance of securities.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Regulation of issuance of securities. 20.2 Section 20.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... Regulation of issuance of securities. The licensee or other person issuing or proposing to issue any...

  9. 18 CFR 20.2 - Regulation of issuance of securities.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Regulation of issuance of securities. 20.2 Section 20.2 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE FEDERAL POWER ACT AUTHORIZATION OF THE ISSUANCE OF SECURITIES BY LICENSEES AND...

  10. Culture, Learning Styles, and Web 2.0

    ERIC Educational Resources Information Center

    Olaniran, Bolanle A.

    2009-01-01

    This article explores Web 2.0 in interactive learning environments. Specifically, the article examines Web 2.0 as an interactive learning platform that holds potential, but is also limited by learning styles and cultural value preferences. The article explores the issue of control from both teacher and learner perspectives, and in particular the…

  11. 50 CFR 20.2 - Relation to other provisions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Relation to other provisions. 20.2 Section 20.2 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) TAKING, POSSESSION, TRANSPORTATION, SALE, PURCHASE, BARTER, EXPORTATION, AND IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY...

  12. Untangling Web 2.0's Influences on Student Learning

    ERIC Educational Resources Information Center

    Magolda, Peter M.; Platt, Glenn J.

    2009-01-01

    The recent creation of Web 2.0 applications dramatically alters the ways in which universities recruit and educate students. Technology insiders usually attribute the phrase "Web 2.0" to Tim O'Reilly, author and publisher of the ubiquitous O'Reilly series of technology books (http://oreilly.com). Although there is no shortage of definitions of Web…

  13. Elevation-Dependent Temperature Trends in the Rocky Mountain Front Range: Changes over a 56- and 20-Year Record

    PubMed Central

    McGuire, Chris R.; Nufio, César R.; Bowers, M. Deane; Guralnick, Robert P.

    2012-01-01

    Determining the magnitude of climate change patterns across elevational gradients is essential for an improved understanding of broader climate change patterns and for predicting hydrologic and ecosystem changes. We present temperature trends from five long-term weather stations along a 2077-meter elevational transect in the Rocky Mountain Front Range of Colorado, USA. These trends were measured over two time periods: a full 56-year record (1953–2008) and a shorter 20-year (1989–2008) record representing a period of widely reported accelerating change. The rate of change of biological indicators, season length and accumulated growing-degree days, were also measured over the 56 and 20-year records. Finally, we compared how well interpolated Parameter-elevation Regression on Independent Slopes Model (PRISM) datasets match the quality controlled and weather data from each station. Our results show that warming signals were strongest at mid-elevations over both temporal scales. Over the 56-year record, most sites show warming occurring largely through increases in maximum temperatures, while the 20-year record documents warming associated with increases in maximum temperatures at lower elevations and increases in minimum temperatures at higher elevations. Recent decades have also shown a shift from warming during springtime to warming in July and November. Warming along the gradient has contributed to increases in growing-degree days, although to differing degrees, over both temporal scales. However, the length of the growing season has remained unchanged. Finally, the actual and the PRISM interpolated yearly rates rarely showed strong correlations and suggest different warming and cooling trends at most sites. Interpretation of climate trends and their seasonal biases in the Rocky Mountain Front Range are dependent on both elevation and the temporal scale of analysis. Given mismatches between interpolated data and the directly measured station data, we caution

  14. Carbon Cycle 2.0: Ashok Gadgil: global impact

    ScienceCinema

    Ashok Gadgi

    2010-09-01

    Ashok Gadgil speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 2, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

  15. Biofuels Science and Facilities (Carbon Cycle 2.0)

    ScienceCinema

    Keasling, Jay D

    2011-06-03

    Jay D. Keasling speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 2, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

  16. Carbon Cycle 2.0: Ashok Gadgil: global impact

    SciTech Connect

    Ashok Gadgi

    2010-02-09

    Ashok Gadgil speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 2, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

  17. Energy Demand in China (Carbon Cycle 2.0)

    ScienceCinema

    Price, Lynn

    2011-06-08

    Lynn Price, LBNL scientist, speaks at the Carbon Cycle 2.0 kick-off symposium Feb. 2, 2010. We emit more carbon into the atmosphere than natural processes are able to remove - an imbalance with negative consequences. Carbon Cycle 2.0 is a Berkeley Lab initiative to provide the science needed to restore this balance by integrating the Labs diverse research activities and delivering creative solutions toward a carbon-neutral energy future. http://carboncycle2.lbl.gov/

  18. Precise Determination of the Intensity of 226Ra Alpha Decay to the 186 keV Excited State

    SciTech Connect

    S.P. LaMont; R.J. Gehrke; S.E. Glover; R.H. Filby

    2001-04-01

    There is a significant discrepancy in the reported values for the emission probability of the 186 keV gamma-ray resulting from the alpha decay of 226 Ra to 186 keV excited state of 222 Rn. Published values fall in the range of 3.28 to 3.59 gamma-rays per 100 alpha-decays. An interesting observation is that the lower value, 3.28, is based on measuring the 186 keV gamma-ray intensity relative to the 226 Ra alpha-branch to the 186 keV level. The higher values, which are close to 3.59, are based on measuring the gamma-ray intensity from mass standards of 226 Ra that are traceable to the mass standards prepared by HÓNIGSCHMID in the early 1930''s. This discrepancy was resolved in this work by carefully measuring the 226 Ra alpha-branch intensities, then applying the theoretical E2 multipolarity internal conversion coefficient of 0.692±0.007 to calculate the 186 keV gamma-ray emission probability. The measured value for the alpha branch to the 186 keV excited state was (6.16±0.03)%, which gives a 186 keV gamma-ray emission probability of (3.64±0.04)%. This value is in excellent agreement with the most recently reported 186 keV gamma-ray emission probabilities determined using 226 Ra mass standards.

  19. Effects of combined irradiation of 500 keV protons and atomic oxygen on polyimide films

    NASA Astrophysics Data System (ADS)

    Novikov, Lev; Chernik, Vladimir; Zhilyakov, Lev; Voronina, Ekaterina; Chirskaia, Natalia

    2016-07-01

    Polyimide films are widely used on the spacecraft surface as thermal control coating, films in different constuctions, etc. However, the space ionizing radiation of different types can alter the mechanical, optical and electrical properties of polyimide films. For example, it is well known that 20-100 keV proton irradiation causes breaking of chemical bonds and destruction of the surface layer in polyimide, deterioration of its optical properties, etc. In low-Earth orbits serious danger for polymeric materials is atomic oxygen of the upper atmosphere of the Earth, which is the main component in the range of heights of 200-800 km. Due to the orbital spacecraft velocity, the collision energy of oxygen atoms with the surface ( 5 eV) enhances their reactivity and opens additional pathways of their reaction with near-surface layers of materials. Hyperthermal oxygen atom flow causes erosion of the polyimide surface by breaking chemical bonds and forming of volatiles products (primarily, CO and CO _{2}), which leads to mass losses and degradation of material properties. Combined effect of protons and oxygen plasma is expected to give rise to synergistic effects enhancing the destruction of polyimide surface layers. This paper describes experimental investigation of polyimide films sequential irradiation with protons and oxygen plasma. The samples were irradiated by 500 keV protons at fluences of 10 ^{14}-10 ^{16} cm ^{-2} produced with SINP cascade generator KG-500 and 5-20 eV neutral oxygen atoms at fluence of 10 ^{20} cm ^{-2} generated by SINP magnetoplasmodynamics accelerator. The proton bombardment causes the decrease in optical transmission coefficient of samples, but their transmittance recovers partially after the exposure to oxygen plasma. The results of the comparative analysis of polyimide optical transmission spectra, Raman and XPS spectra obtained at different stages of the irradiation of samples, data on mass loss of samples due to erosion of the surface are

  20. Oh! Web 2.0, Virtual Reference Service 2.0, Tools and Techniques (I): A Basic Approach

    ERIC Educational Resources Information Center

    Arya, Harsh Bardhan; Mishra, J. K.

    2011-01-01

    This study targets librarians and information professionals who use Web 2.0 tools and applications with a view to providing snapshots on how Web 2.0 technologies are used. It also aims to identify values and impact that such tools have exerted on libraries and their services, as well as to detect various issues associated with the implementation…

  1. Enabling the transition towards Earth Observation Science 2.0

    NASA Astrophysics Data System (ADS)

    Mathieu, Pierre-Philippe; Desnos, Yves-Louis

    2015-04-01

    Science 2.0 refers to the rapid and systematic changes in doing Research and organising Science driven by the rapid advances in ICT and digital technologies combined with a growing demand to do Science for Society (actionable research) and in Society (co-design of knowledge). Nowadays, teams of researchers around the world can easily access a wide range of open data across disciplines and remotely process them on the Cloud, combining them with their own data to generate knowledge, develop information products for societal applications, and tackle complex integrative complex problems that could not be addressed a few years ago. Such rapid exchange of digital data is fostering a new world of data-intensive research, characterized by openness, transparency, and scrutiny and traceability of results, access to large volume of complex data, availability of community open tools, unprecedented level of computing power, and new collaboration among researchers and new actors such as citizen scientists. The EO scientific community is now facing the challenge of responding to this new paradigm in science 2.0 in order to make the most of the large volume of complex and diverse data delivered by the new generation of EO missions, and in particular the Sentinels. In this context, ESA - in particular within the framework of the Scientific Exploitation of Operational Missions (SEOM) element - is supporting a variety of activities in partnership with research communities to ease the transition and make the most of the data. These include the generation of new open tools and exploitation platforms, exploring new ways to exploit data on cloud-based platforms, dissiminate data, building new partnership with citizen scientists, and training the new generation of data scientists. The paper will give a brief overview of some of ESA activities aiming to facilitate the exploitation of large amount of data from EO missions in a collaborative, cross-disciplinary, and open way, from science to

  2. Measurements of complex permittivity of microwave substrates in the 20 to 300 K temperature range from 26.5 to 40.0 GHz

    NASA Technical Reports Server (NTRS)

    Miranda, Felix A.; Gordon, William L.; Heinen, Vernon O.; Ebihara, Ben T.; Bhasin, Kul B.

    1989-01-01

    A knowledge of the dielectric properties of microwave substrates at low temperatures is useful in the design of superconducting microwave circuits. Results are reported for a study of the complex permittivity of sapphire (Al2O3), magnesium oxide (MgO), silicon oxide (SiO2), lanthanum aluminate (LaAlO3), and zirconium oxide (ZrO2), in the 20 to 300 Kelvin temperature range, at frequencies from 26.5 to 40.0 GHz. The values of the real and imaginary parts of the complex permittivity were obtained from the scattering parameters, which were measured using a HP-8510 automatic network analyzer. For these measurements, the samples were mounted on the cold head of a helium gas closed cycle refrigerator, in a specially designed vacuum chamber. An arrangement of wave guides, with mica windows, was used to connect the cooling system to the network analyzer. A decrease in the value of the real part of the complex permittivity of these substrates, with decreasing temperature, was observed. For MgO and Al2O3, the decrease from room temperature to 20 K was of 7 and 15 percent, respectively. For LaAlO3, it decreased by 14 percent, for ZrO2 by 15 percent, and for SiO2 by 2 percent, in the above mentioned temperature range.

  3. Measurements of complex permittivity of microwave substrates in the 20 to 300 K temperature range from 26.5 to 40.0 GHz

    NASA Technical Reports Server (NTRS)

    Miranda, Felix A.; Gordon, William L.; Heinen, Vernon O.; Ebihara, Ben T.; Bhasin, Kul B.

    1990-01-01

    A knowledge of the dielectric properties of microwve substrates at low temperatures is useful in the design of superconducting microwave circuits. Results are reported for a study of the complex permittivity of sapphire (Al2O3), magnesium oxide (MgO), silicon oxide (SiO2), lanthanum aluminate (LaAlO3), and zirconium oxide (ZrO2), in the 20 to 300 Kelvin temperature range, at frequencies from 26.5 to 40.0 GHz. The values of the real and imaginary parts of the complex permittivity were obtained from the scattering parameters, which were measured using an HP-8510 automatic network analyzer. For these measurements, the samples were mounted on the cold head of a helium gas closed cycle refrigerator, in a specially designated vacuum chamber. An arrangement of wave guides, with mica windows, was used to connect the cooling system to the network analyzer. A decrease in the value of the real part of the complex permittivity of these substrates, with decreasing temperature, was observed. For MgO and Al2O3, the decrease from room temperature to 20 K was of 7 and 15 percent, respectively. For LaAlO3, it decreased by 14 percent, for ZrO2 by 15 percent, and for SiO2 by 2 percent, in the above mentioned temperature range.

  4. Extreme energetic electron fluxes in low Earth orbit: Analysis of POES E > 30, E > 100, and E > 300 keV electrons

    NASA Astrophysics Data System (ADS)

    Meredith, Nigel P.; Horne, Richard B.; Isles, John D.; Green, Janet C.

    2016-02-01

    Energetic electrons are an important space weather hazard. Electrons with energies less than about 100 keV cause surface charging, while higher-energy electrons can penetrate materials and cause internal charging. In this study we conduct an extreme value analysis of the maximum 3-hourly flux of E > 30 keV, E > 100 keV, and E > 300 keV electrons in low Earth orbit as a function of L∗, for geomagnetic field lines that map to the outer radiation belt, using data from the National Oceanic and Atmospheric Administration Polar Operational Environmental Satellites (POES) from July 1998 to June 2014. The 1 in 10 year flux of E > 30 keV electrons shows a general increasing trend with distance ranging from 1.8 × 107 cm-2 s-1 sr-1 at L∗=3.0 to 6.6 × 107 cm-2 s-1 sr-1 at L∗=8.0. The 1 in 10 year flux of E > 100 keV electrons peaks at L∗=4.5-5.0 at 1.9 × 107 cm-2 s-1 sr-1 decreasing to minima of 7.1 × 106 and 8.7 × 106 cm-2 s-1 sr-1 at L∗=3.0 and 8.0, respectively. In contrast to the E > 30 keV electrons, the 1 in 10 year flux of E > 300 keV electrons shows a general decreasing trend with distance, ranging from 2.4 × 106 cm-2 s-1 sr-1 at L∗=3.0 to 1.2 × 105 cm-2 s-1 sr-1 at L∗=8.0. Our analysis suggests that there is a limit to the E > 30 keV electrons with an upper bound in the range 5.1 × 107 to 8.8 × 107 cm-2 s-1 sr-1. However, the results suggest that there is no upper bound for the E > 100 keV and E > 300 keV electrons.

  5. 21 CFR 556.20 - 2-Acetylamino-5-nitrothiazole.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false 2-Acetylamino-5-nitrothiazole. 556.20 Section 556.20 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs...

  6. Online Reputation Systems in Web 2.0 Era

    NASA Astrophysics Data System (ADS)

    Zheng, Weijun; Jin, Leigh

    Web 2.0 has transformed how reputation systems are designed and used by the Web. Based on a thorough review of the existing online reputation systems and their challenges in use, this paper studied a case of Amazon’s reputation system for the impacts of Web 2.0. Through our case study, several distinguished features of new generation reputation systems are noted including multimedia feedbacks, reviewer centered, folksonomy, community contribution, comprehensive reputation, dynamic and interactive system etc. These new developments move towards a relatively trustworthy and reliable online reputation system in the Web 2.0 era.

  7. Study of the angular-dependence of the L-alpha and L-beta radiation produced by 0-15 kev photons incident on Au targets of various thicknesses

    NASA Astrophysics Data System (ADS)

    Requena, Sebastian; Williams, Scott

    2011-03-01

    We report the results of experiments involving the L-alpha and L-beta x-ray lines produced by 0-15 keV bremsstrahlung incident on gold targets of various thicknesses at forward-scattered angles ranging from 20 to 160 degrees. Previous reports [1, 2] have shown the L-beta peaks to be isotropic and the L-alpha peaks to be anisotropic due to the symmetry/asymmetry associated with the orbital being filled during the transition. The relative intensities are compared to the predictions of the Monte Carlo code, PENELOPE.

  8. 25-Hydroxyvitamin D in the Range of 20 to 100 ng/mL and Incidence of Kidney Stones

    PubMed Central

    Nguyen, Stacie; Baggerly, Leo; French, Christine; Heaney, Robert P.; Gorham, Edward D.

    2014-01-01

    Objectives. Increasing 25-hydroxyvitamin D serum levels can prevent a wide range of diseases. There is a concern about increasing kidney stone risk with vitamin D supplementation. We used GrassrootsHealth data to examine the relationship between vitamin D status and kidney stone incidence. Methods. The study included 2012 participants followed prospectively for a median of 19 months. Thirteen individuals self-reported kidney stones during the study period. Multivariate logistic regression was applied to assess the association between vitamin D status and kidney stones. Results. We found no statistically significant association between serum 25-hydroxyvitamin D and kidney stones (P = .42). Body mass index was significantly associated with kidney stone risk (odds ratio = 3.5; 95% confidence interval = 1.1, 11.3). Conclusions. We concluded that a serum 25-hydroxyvitamin D level of 20 to 100 nanograms per milliliter has no significant association with kidney stone incidence. PMID:24134366

  9. Steady State Sputtering Yields and Surface Compositions of Depleted Uranium and Uranium Carbide bombarded by 30 keV Gallium or 16 keV Cesium Ions.

    SciTech Connect

    Siekhaus, W. J.; Teslich, N. E.; Weber, P. K.

    2014-10-23

    Depleted uranium that included carbide inclusions was sputtered with 30-keV gallium ions or 16-kev cesium ions to depths much greater than the ions’ range, i.e. using steady-state sputtering. The recession of both the uranium’s and uranium carbide’s surfaces and the ion corresponding fluences were used to determine the steady-state target sputtering yields of both uranium and uranium carbide, i.e. 6.3 atoms of uranium and 2.4 units of uranium carbide eroded per gallium ion, and 9.9 uranium atoms and 3.65 units of uranium carbide eroded by cesium ions. The steady state surface composition resulting from the simultaneous gallium or cesium implantation and sputter-erosion of uranium and uranium carbide were calculated to be U₈₆Ga₁₄, (UC)₇₀Ga₃₀ and U₈₁Cs₉, (UC)₇₉Cs₂₁, respectively.

  10. Elastic scattering of electrons from CO2 in the intermediate energy range

    NASA Astrophysics Data System (ADS)

    Iga, I.; Nogueira, J. C.; Mu-Tao, L.

    1984-03-01

    Ratios of elastic differential cross sections of CO2 to those of N2 have been measured at electron impact energies of 500, 800 and 1000 eV in the angular range of 5 deg to 120 deg, using a crossed electron-beam-molecular-beam geometry and the relative flow technique. These ratios have been multiplied by previously known N2 elastic differential cross sections to obtain elastic differential cross sections for CO2. At 500 eV, experimental results agree quite well with the absolute values of Bromberg (1974). Comparison has also been made with the theoretical results obtained in the renormalized multicenter potential model approach of Botelho et al. (1983) and shows an agreement within 20 percent in the entire angular range. The elastic integral and momentum transfer cross sections have also been determined from the differential cross sections.

  11. SFA 2.0- Watershed Structure and Controls

    SciTech Connect

    Williams, Ken

    2015-01-23

    Berkeley Lab Earth Scientist Ken Williams explains the watershed research within the Sustainable Systems SFA 2.0 project—including identification and monitoring of primary factors that control watershed biogeochemical functioning.

  12. 20. DETAILED OBLIQUE VIEW SOUTHWEST FURNACE 2, SHOWING STEEL FRAME ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. DETAILED OBLIQUE VIEW SOUTHWEST FURNACE 2, SHOWING STEEL FRAME BOXES FOR COUNTERWEIGHTS, AND FURNACE HEATING PIPES AT RIGHT. - Vulcan Crucible Steel Company, Building No. 3, 100 First Street, Aliquippa, Beaver County, PA

  13. 20 CFR 718.2 - Applicability of this part.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... of this subchapter (see 20 CFR 725.4(d)) cannot be approved under that subpart, such claim may be... DEATH DUE TO PNEUMOCONIOSIS General § 718.2 Applicability of this part. With the exception of the...

  14. 2. Historic American Buildings Survey Robert Brandeis, Photographer December 20, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Historic American Buildings Survey Robert Brandeis, Photographer December 20, 1978 THREE- QUARTER VIEW OF NORTH (FRONT) ELEVATION AND WEST (SIDE) ELEVATION - 3397-3399 Sacramento Street (House), San Francisco, San Francisco County, CA

  15. 2. Historic American Buildings Survey Photocopy from Harpers, vol. 20 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Historic American Buildings Survey Photocopy from Harpers, vol. 20 1859 Courtesy of Library of Congress NORTH AND EAST FRONTS - United States General Post Office, Between Seventh, Eighth, E, & F Streets, Northwest, Washington, District of Columbia, DC

  16. 2. SANDY RIVER BRIDGE AT TROUTDALE, SOUTH END, LOOKING 20 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. SANDY RIVER BRIDGE AT TROUTDALE, SOUTH END, LOOKING 20 DEGREES NORTH. - Historic Columbia River Highway, Sandy River Bridge at Troutdale, Historic Columbia River Highway spanning Sandy River, Troutdale, Multnomah County, OR

  17. 20. Governor Accumulator Tanks for Units 1 and 2, view ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. Governor Accumulator Tanks for Units 1 and 2, view to the north. - Washington Water Power Clark Fork River Cabinet Gorge Hydroelectric Development, Powerhouse, North Bank of Clark Fork River at Cabinet Gorge, Cabinet, Bonner County, ID

  18. Guidelines for the undergraduate psychology major: Version 2.0.

    PubMed

    2016-01-01

    The APA Guidelines for the Undergraduate Psychology Major: Version 2.0 (henceforth Guidelines 2.0; APA, 2013) represents a national effort to describe and develop high-quality undergraduate programs in psychology. The task force charged with the revision of the original guidelines for the undergraduate major examined the success of the document's implementation and made changes to reflect emerging best practices and to integrate psychology's work with benchmarking scholarship in higher education. Guidelines 2.0 abandoned the original distinction drawn between psychology-focused skills and psychology skills that enhance liberal arts development. Instead, Guidelines 2.0 describes five inclusive goals for the undergraduate psychology major and two developmental levels of student learning outcomes. Suggestions for assessment planning are provided for each of the five learning goals. PMID:26866986

  19. The dynamic range of LZ

    NASA Astrophysics Data System (ADS)

    Yin, J.

    2016-02-01

    The electronics of the LZ experiment, the 7-tonne dark matter detector to be installed at the Sanford Underground Research Facility (SURF), is designed to permit studies of physics where the energies deposited range from 1 keV of nuclear-recoil energy up to 3,000 keV of electron-recoil energy. The system is designed to provide a 70% efficiency for events that produce three photoelectrons in the photomultiplier tubes (PMTs). This corresponds approximately to the lowest energy threshold achievable in multi-tonne time-projection chambers, and drives the noise specifications for the front end. The upper limit of the LZ dynamic range is defined to accommodate the electroluminescence (S2) signals. The low-energy channels of the LZ amplifiers provide the dynamic range required for the tritium and krypton calibrations. The high-energy channels provide the dynamic range required to measure the activated Xe lines.

  20. RadCat 2.0 User Guide.

    SciTech Connect

    Osborn, Douglas.; Weiner, Ruth F.; Mills, George Scott; Hamp, Steve C.; O'Donnell, Brandon, M.; Orcutt, David J.; Heames, Terence J.; Hinojosa, Daniel

    2005-01-01

    This document provides a detailed discussion and a guide for the use of the RadCat 2.0 Graphical User Interface input file generator for the RADTRAN 5.5 code. The differences between RadCat 2.0 and RadCat 1.0 can be attributed to the differences between RADTRAN 5 and RADTRAN 5.5 as well as clarification for some of the input parameters. 3