Science.gov

Sample records for 2 20 kev range

  1. 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.

  2. 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.

  3. R-Matrix Analysis of 238U High Resolution Neutron Transmissions and Capture Cross Sections in the Energy Range 0 keV to 20 keV

    SciTech Connect

    Derrien, Herve; Leal, Luiz C; Larson, Nancy M

    2009-01-01

    The neutron resonance parameters of 238U 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 to 200 pcm.

  4. SOLEX: a tunable monochromatic X-ray source in the 1-20 keV energy range for metrology

    NASA Astrophysics Data System (ADS)

    Bonnelle, C.; Jonnard, P.; André, J.-M.; Avila, A.; Laporte, D.; Ringuenet, H.; Lépy, M. C.; Plagnard, J.; Ferreux, L.; Protas, J. C.

    2004-01-01

    A tunable monochromatic X-ray source covering the 1-20 keV energy range is described. The initial X-ray beam is obtained from a dedicated windowless X-ray tube. The energy selection is performed through a cylindrically bent crystal, used either in the reflection (Johann geometry) or in the transmission (Cauchois geometry) mode, by rotating the crystal holder by a 90° angle. Contrary to conventional geometries where the X-ray tube is fixed, here the direction of the exit beam impinging the X-ray detector is fixed. This setup is shown to be useful for various studies: high-resolution spectrometry, characterization of the response function and the efficiency of detectors and optical components, determination of transmission characteristics of different materials. Observations of the Lα line and Kα doublet from a copper anode are presented, that demonstrate the performance of this new setup.

  5. FIRST INTEGRAL OBSERVATIONS OF V404 CYGNI DURING THE 2015 OUTBURST: SPECTRAL BEHAVIOR IN THE 20–650 KeV ENERGY RANGE

    SciTech Connect

    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 (kT{sub 0} ∼ 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{sup −4} ph cm{sup −2} s{sup −1} (2σ) for a narrow line centered at 511 keV, on the averaged obtained spectrum.

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

    NASA Astrophysics Data System (ADS)

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

    1983-04-01

    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).

  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. 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.

  13. Neutron scattering measurements in {sup 197}Au from 850 keV to 2.0 MeV

    SciTech Connect

    O`Connor, M.; Chen, J.; Egan, J.J.

    1995-10-01

    Differential elastic and inelastic neutron scattering cross-sections for low lying levels in {sup 197}Au have been measured for incident neutron energies of 1.0 MeV, 1.5 MeV and 2.0 MeV. In addition, the total neutron cross sections in {sup 197}Au was measured from 850 keV to 1.5 MeV. For both experiments the UML 5.5 MV Van-de-Graaff accelerator with a Mobley post acceleration compression system, produced subnanosecond proton pulses which generated neutrons via the {sup 7}Li(p,n) {sup 7}Be reaction.

  14. Observation of lithium pick-up ions in the 5- to 20-keV energy range following the AMPTE solar wind releases

    SciTech Connect

    Moebius, E.; Hovestadt, D.; Klecker, B.; Scholer, M.; Gloeckler, G.; Ipavich, F.M.; Luehr, H.

    1986-02-01

    Newly created 5- to 20-keV lithium ions were observed for limited time periods following the first Active Magnetospheric Particle Tracer Explorers (AMPTE) lithium release in the solar wind on September 11, 1984. The detection of these so-called ''pick-up'' ions by the time-of-flight spectrometer SULEICA (suprathermal energy ionic charge analyzer) on the AMPTE/IRM satellite depends critically on the orientation of the interplanetary magnetic field with respect to the directions of the solar wind and the spin axis of the IRM spacecraft, which was favorable only during the short time when these ions were seen. Our observations are compatible with a shell-like expansion of the Li cloud with velocities of about 2.5 km/s. The signatures by which the artificial pick-up ions are identified can also be used to detect and investigate natural pick-up ions.

  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. Angular distribution of thick-target bremsstrahlung produced by electrons with initial energies ranging from 10 to 20 keV incident on Ag

    SciTech Connect

    Gonzales, D.; Cavness, B.; Williams, S.

    2011-11-15

    Experimental results are presented comparing the intensities of the bremsstrahlung produced by electrons with initial energies ranging from 10 to 20 keV incident on a thick Ag target, measured at forward angles in the range of 0 degree sign to 55 degree sign . 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 E{sub 0}. The results of our experiments suggest that, as k/E{sub 0}{yields} 0, the detected radiation essentially becomes isotropic due primarily to the scattering of electrons within the target. A 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/E{sub 0}{approx_equal} 1. The experimental data also are in approximate agreement with the angular distribution predictions of the Monte Carlo program penelope.

  17. AMANDE: a new facility for monoenergetic neutron fields production between 2 keV and 20 MeV.

    PubMed

    Gressier, V; Guerre-Chaley, J F; Lacoste, V; Lebreton, L; Pelcot, G; Pochat, J L; Bolognese-Milstajn, T; Champion, D

    2004-01-01

    The variation of the response of the instruments with the neutron energy has to be determined in well-characterized monoenergetic neutron fields. The AMANDE facility will deliver such neutron fields between 2 keV and 20 MeV in an experimental hall designed with metallic walls for neutron scattering minimisation. The neutrons will be produced by nuclear interaction of accelerated protons or deuterons on thin targets of selected materials. The measuring devices to be characterised will be accurately placed with a fully automated detector transport system. The energy of the neutron field will be validated by time-of-flight experiments and a large set of standard detectors and fluence monitors will be used to determine the neutron fluence references. The scattered neutron fluence and dose equivalent were calculated by the MCNP Monte Carlo code at several measuring points in order to determine their contribution to the neutron field.

  18. (239)Pu neutron resonance parameters revisited and covariance matrix in the neutron energy range from thermal to 2.5 keV

    SciTech Connect

    Derrien, Herve; Leal, Luiz C; Larson, Nancy M

    2008-01-01

    To obtain the resonance parameters in a single energy range up to 2.5 keV neutron energy and the corresponding covariance matrix, a reevaluation of 239Pu was performed with the analysis code SAMMY. The most recent experimental data were analyzed in the energy range thermal to 2.5 keV. The experimental data were renormalized, aligned on a common energy scale, and corrected for residual background. Average neutron transmission and cross sections calculated with the new resonance parameters were compared to the corresponding experimental data and to ENDF/B-VI.

  19. 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

  20. 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

  1. 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.

  2. Single-crystal CVD diamond detector for low-energy charged particles with energies ranging from 100 keV to 2 MeV

    SciTech Connect

    Yuki Sato; Hiroyuki Murakami; Takehiro Shimaoka; Masakatsu Tsubota; Junichi, H. Kaneko

    2015-07-01

    The performance of a diamond detector made of a single-crystal diamond grown by chemical vapor deposition was studied for charged particles, having energies ranging from 100 keV to 2 MeV. Energy peaks of these low-energy ions were clearly observed. However, we observed that the pulse height for individual incident ion decreases with increasing atomic number of the ions. We estimated the charge collection efficiency of the generated charge carriers by charged particle incident. The charge collection above ∼95% is achieved for helium (He{sup +}) with the energy above 1.5 MeV. On the other hand, the charge collection efficiency for heavy-ions shows wrong values compared with that of He{sup +}, ∼70% for silicon (Si{sup +}) and 35 to 40% for gold (Au{sup 3+}), at the same incident energy range, respectively. (authors)

  3. 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.

  4. 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.

  5. Total electron scattering cross sections of molecules containing H, C, N, O and F in the energy range 0.2-6.0 keV

    NASA Astrophysics Data System (ADS)

    Gurung, Meera Devi; Ariyasinghe, W. M.

    2017-03-01

    Based on the effective atomic total electron scattering cross sections (EATCS) of atoms in a molecular environment, a simple model is proposed to predict the total electron scattering cross sections (TCS) of H, C, N, O, and F containing molecules. The EATCS for these five atoms are reported for 0.2-6.0 keV energies. The predicted TCS by this model are compared with experimental TCS in the literature. The experimental TCS of CHF3, C2F4, C2F2H2, C4F6, and c-C4F8 have been obtained for 0.2-4.5 keV electrons by measuring the attenuation of the electron beam through a gas cell.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. R-matrix analysis of {sup 235}U neutron transmission and cross sections in the energy range 0 to 2.25 keV

    SciTech Connect

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

    1997-11-01

    This document describes a new R-matrix analysis of {sup 235}U cross section data in the energy range from 0 to 2,250 eV. The analysis was performed with the computer code SAMMY, that has recently been updated to permit, for the first time, inclusion of both differential and integral data within the analysis process. Fourteen differential data sets and six integral quantities were used in this evaluation: two measurements of fission plus capture, one of fission plus absorption, six of fission alone, two of transmission, and one of eta, plus standard values of thermal cross sections for fission, capture, and scattering, and of K1 and the Westcott g-factors for both fission and absorption. An excellent representation was obtained for the high-resolution transmission, fission, and capture cross-section data as well as for the integral quantities. The result is a single set of resonance parameters spanning the entire range up to 2,250 eV, a decided improvement over the present ENDF/VI evaluation, in which eleven discrete resonance parameter sets are required to cover that same energy range. This new evaluation is expected to greatly improve predictability of the criticality safety margins for nuclear systems in which {sup 235}U is present.

  11. 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.

  12. Spectroscopy from 2 to 200 keV

    NASA Technical Reports Server (NTRS)

    Helfand, D. J.; Chanan, G. A.; Novick, R.; Maccallum, C. J.; Leventhal, M.

    1981-01-01

    The astrophysical processes responsible for line and continuum emission in the spectra range 2 keV to 200 keV are examined from the viewpoint of designing a spectrometer which would operate in this regime. Phenomena considered include fluorescent line radiation in X-ray binaries, magnetically shifted iron lines and cyclotron emission from neutron star surfaces, line emission from cosmically abundant elements in thermal plasmas, and nuclear deexcitation lines in fresh nucleosynthetically produced matter. An instrument consisting of a approximately 10 sq cm array of planar germanium detectors surrounded by a large sodium-iodide anticoincidence shield is described and projected background rates and sensitivities are considered. A sample observing program for a two-day shuttle-based mission is included as an example of the wide range of scientific questions which could be addressed by such an instrument.

  13. 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.

  14. Measurement of the Np237(n,γ) cross section from 20 meV to 500 keV with a high efficiency, highly segmented 4π BaF2 detector

    NASA Astrophysics Data System (ADS)

    Esch, E.-I.; Reifarth, R.; Bond, E. M.; Bredeweg, T. A.; Couture, A.; Glover, S. E.; Greife, U.; Haight, R. C.; Hatarik, A. M.; Hatarik, R.; 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.

    2008-03-01

    The Np237(n,γ)Np238 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 Np237 was sufficient to determine differential cross sections relative to the well-known resonance at 0.5 eV. The thermal cross section was measured to σ2200m/s=177±5 barn, σkT=25.3meV=167±4 barn and the resonance integral to RI=693±6 barn.

  15. 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.

  16. 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).

  17. 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.

  18. High resolution spectrometer for extended x-ray absorption fine structure measurements in the 6 keV to 15 keV energy range

    NASA Astrophysics Data System (ADS)

    Seely, J. F.; Hudson, L. T.; Henins, Albert; Feldman, U.

    2016-11-01

    A Cauchois transmission-crystal spectrometer has been developed with high crystal resolving power in the 6 keV-15 keV energy range and sufficient sensitivity to record single-shot spectra from the Lawrence Livermore National Laboratory (LLNL) Titan laser and other comparable or more energetic lasers. The spectrometer capabilities were tested by recording the W L transitions from a laboratory source and the extended x-ray absorption fine structure (EXAFS) spectrum through a Cu foil.

  19. 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.

  20. Luminescent collisions of He+ and He++ ions with H2 molecules at energies below 2 keV

    NASA Astrophysics Data System (ADS)

    Pranszke, B.; Werbowy, S.; Miotk, R.; Borkowski, K. J.; Kowalski, A.

    2013-10-01

    Spectroscopic studies of collisions between He+ and He++ ions with H2 gas target have been performed in the 200-600 nm wavelength range. Atomic lines of hydrogen Balmer series and several helium lines were identified and their excitation functions between 50 eV and 1 keV (2 keV for He++) were determined.

  1. Monte Carlo calculations of energy deposition distributions of electrons below 20 keV in protein.

    PubMed

    Tan, Zhenyu; Liu, Wei

    2014-05-01

    The distributions of energy depositions of electrons in semi-infinite bulk protein and the radial dose distributions of point-isotropic mono-energetic electron sources [i.e., the so-called dose point kernel (DPK)] in protein have been systematically calculated in the energy range below 20 keV, based on Monte Carlo methods. The ranges of electrons have been evaluated by extrapolating two calculated distributions, respectively, and the evaluated ranges of electrons are compared with the electron mean path length in protein which has been calculated by using electron inelastic cross sections described in this work in the continuous-slowing-down approximation. It has been found that for a given energy, the electron mean path length is smaller than the electron range evaluated from DPK, but it is large compared to the electron range obtained from the energy deposition distributions of electrons in semi-infinite bulk protein. The energy dependences of the extrapolated electron ranges based on the two investigated distributions are given, respectively, in a power-law form. In addition, the DPK in protein has also been compared with that in liquid water. An evident difference between the two DPKs is observed. The calculations presented in this work may be useful in studies of radiation effects on proteins.

  2. 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.

  3. Feasibility study for DEXA using synchrotron CT at 20-35 keV

    NASA Astrophysics Data System (ADS)

    Midgley, S. M.

    2013-02-01

    A nonlinear model for the x-ray linear attenuation coefficient μ is employed for dual energy x-ray analysis (DEXA). Nonlinear simultaneous equations formed by μ and energy dependent model parameters are solved for the electron density Ne and fourth compositional ratio R4 which has the same ‘units’ as the atomic number. Computed tomography data was acquired at 20-35 keV using bending magnet synchrotron radiation, a double crystal monochromator, a rotation stage and an area detector. Test objects contained liquid samples as mixtures of ethanol, water and salt solutions with known density and composition. Various noise sources are identified and give μ uncertainties of 1-2%. A fan beam geometry allowed the detection of forward scattered radiation with measured μ being 6% lower than expectations for a narrow beam. Energy dependent model parameters were obtained by solving linear simultaneous equations formed by μ and material parameters based upon Ne and R4. DEXA accuracy was studied as a function of photon energy and sample composition. Propagation of errors analysis identifies the importance of the fractional compositional cross-products whose difference at the two beam energies should exceed 0.1, requiring 10 keV or more separation. For a reasonable approximation for the adjustable model parameters, the mean difference between the DEXA solution and true values (ΔNe, ΔR4) are (1.0%, 0.5%) for soft tissue and (1.5%, 0.8%) for bone like samples.

  4. 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.

  5. 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.

  6. Calculations of stopping powers and inelastic mean free paths for 20 eV-20 keV electrons in 11 types of human tissue.

    PubMed

    Tan, Zhenyu; Liu, Wei

    2013-12-01

    Systematic calculations are performed for determining the stopping powers (SP) and inelastic mean free paths (IMFP) for 20 eV-20 keV electrons in 11 types of human tissue. The calculations are based on a dielectric model, including the Born-Ochkur exchange correction. The optical energy loss functions (OELF) are empirically evaluated, because of the lack of available experimental optical data for the 11 tissues under consideration. The evaluated OELFs are examined by the f-sum rule expected from the dielectric response theory, and by calculation of the mean excitation energy. The calculated SPs are compared with those for PMMA (polymethylmethacrylate, a tissue equivalent material) and liquid water. The SP and IMFP data presented here are the results for the 11 human tissues over the energy range of 20 eV-20 keV, and are of importance in radiotherapy planning and for studies of various radiation effects on human tissues.

  7. Efficiency of Scintillator Materials in the Energy Range 8.0-32.0 keV

    SciTech Connect

    Kinney, J H; Haupt, D L

    2002-07-01

    X-ray microtomography requires the measurement of x-ray attenuation along ray paths through a specimen, and on the inversion of these data to obtain a spatially resolved mapping of the microstructure of the specimen. To do this efficiently, two-dimensional array detectors are often used to measure the transmitted x-rays by capturing and recording each x-ray incident on the detector. The highest resolution CT instruments perform this by converting the incident x-rays to visible light, and then focusing this light onto a charge-coupled-device (CCD) detector. The light output of the scintillator (photons per incident x-ray), the numerical aperture of the optical lens system, and the quantum efficiency of the CCD govern the efficiency of the detection process. Several years earlier, our group performed an investigation aimed at determining the best scintillator material for high-resolution synchrotron CT. The selection criteria included light output in the 8-32 keV energy range, the spatial resolution of the scintillator, the wavelength of the scintillation radiation, and the stability and ease of polishing of the scintillator. A list of the scintillators that we considered, with the exceptions of the more recently developed glass scintillators, is provided in Table 1. Among these scintillators, we concluded that single crystal cadmium tungstate was optimum; we have used this material in all subsequent synchrotron CT systems. Since this original study, several doped-glass scintillators have become available. The LSO (Lu orthosilicates) scintillators, developed for PET scanning, show considerable light output at high energy (energies above 500 keV). Theoretically, the light output of these scintillators should be twice that of the cadmium tungstate. The purpose of this study was to determine the efficiency of two such scintillators (LSO:Yt and IQI-401 high density terbium activated glass) in the energy range from 8-32 keV.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Injection and diffusive transport of suprathermal through energetic solar flare protons (35 keV to 20 MeV)

    NASA Technical Reports Server (NTRS)

    Beeck, J.; Mason, G. M.; Hamilton, D. C.; Marsden, R. G.; Sanderson, T. R.

    1990-01-01

    Consideration is given to the injection and interplanetary propagation of low-energy protons caused by the solar particle event of July 20, 1981, in which flare protons in the range from 35 keV to 20 MeV were observed by instruments on ISEE 3. The observed time-intensity and time-anisotropy profiles were fitted over the entire energy range using a model based on the spherically symmetric Fokker-Plank equation, including convection, diffusion, and adiabatic deceleration. The results are used to discuss the behavior of the radial interplanetary diffusion coefficient and the scattering mean free path for protons. Also, evidence is found for diffusive coronal shock acceleration of protons during the event.

  14. 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.

  15. 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.

  16. 20-150-keV proton-impact-induced ionization of uracil: Fragmentation ratios and branching ratios for electron capture and direct ionization

    SciTech Connect

    Tabet, J.; Eden, S.; Feil, S.; Abdoul-Carime, H.; Farizon, B.; Farizon, M.; Ouaskit, S.; Maerk, T. D.

    2010-01-15

    Fragmentation ratios and branching ratios are measured for ionization and dissociative ionization for 20-150 keV (0.9-2.4v{sub 0}) proton collisions with gas-phase uracil molecules. Through event-by-event determination of the postcollision projectile charge, it is possible for such a key biomolecule to distinguish between electron capture (EC) by the incident proton and direct ionization (DI) without projectile neutralization. While the same fragment ion groups are observed in the mass spectra for both processes, EC induces dissociation with greater efficiency than DI in the impact energy range of 35-150 keV (1.2-2.4v{sub 0}). In this range EC is also less abundant than DI with a branching ratio for EC/total ionization of <50%. Moreover, whereas fragmentation ratios do not change with energy in the case of EC, DI mass spectra show a tendency for increased fragmentation at lower impact energies.

  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. Characterizations of MCP performance in the hard x-ray range (6–25 keV)

    SciTech Connect

    Wu, Ming Rochau, Greg; Moy, Ken; Kruschwitz, Craig

    2014-11-15

    MCP detector performance at hard x-ray energies from 6 to 25 keV was recently investigated using NSLS beamline X15A at BNL. Measurements were made with an NSTec Gen-II (H-CA-65) framing camera, based on a Photonis MCP with ∼10 μm in diameter pores, ∼12 μm center-center spacing, an L/D ratio of 46, and a bias angle of 8°. The MCP characterizations were focused on (1) energy and angle dependent sensitivity, (2) energy and angle dependent spatial resolution, (3) energy dependent gain performance, and (4) energy dependent dynamic range. These measurement corroborated simulation results using a Monte Carlo model that included hard x-ray interactions and the subsequent electron cascade in the MCP.

  19. Comparison between MCNP and PENELOPE for the simulation of X-ray spectra in electron microscopy in the keV range

    NASA Astrophysics Data System (ADS)

    Roet, D.; Ceballos, C.; Van Espen, P.

    2006-10-01

    In this paper two Monte Carlo codes, MCNP (version 4C2) and PENELOPE (version 2001), were used in a cluster environment to simulate the X-ray spectra emerging from bombarding pure element bulk targets with mono energetic electrons in the keV range (30 keV). The simulation results were compared to experimental data measured on a JEOL-6300 electron microscope with energy dispersive X-ray detector. The results from both codes were compared amongst each other as to find the best in terms of accuracy, ease of use and speed of the calculations.

  20. Effective atomic numbers and electron densities of some biologically important compounds containing H, C, N and O in the energy range 145 1330 keV

    NASA Astrophysics Data System (ADS)

    Manjunathaguru, V.; Umesh, T. K.

    2006-09-01

    A semi-empirical relation which can be used to determine the total attenuation cross sections of samples containing H, C, N and O in the energy range 145-1332 keV has been derived based on the total attenuation cross sections of several sugars, amino acids and fatty acids. The cross sections have been measured by performing transmission experiments in a narrow beam good geometry set-up by employing a high-resolution hyperpure germanium detector at seven energies of biological importance such as 145.4 keV, 279.2 keV, 514 keV, 661.6 keV, 1115.5 keV, 1173.2 keV and 1332.1 keV. The semi-empirical relation can reproduce the experimental values within 1-2%. The total attenuation cross sections of five elements carbon, aluminium, titanium, copper and zirconium measured in the same experimental set-up at the energies mentioned above have been used in a new matrix method to evaluate the effective atomic numbers and the effective electron densities of samples such as cholesterol, fatty acids, sugars and amino acids containing H, C, N and O atoms from their effective atomic cross sections. The effective atomic cross sections are the total attenuation cross sections divided by the total number of atoms of all types in a particular sample. Further, a quantity called the effective atomic weight was defined as the ratio of the molecular weight of a sample to the total number of atoms of all types in it. The variation of the effective atomic number was systematically studied with respect to the effective atomic weight and a new semi-empirical relation for Zeff has been evolved. It is felt that this relation can be very useful to determine the effective atomic number of any sample having H, C, N and O atoms in the energy range 145-1332 keV irrespective of its chemical structure.

  1. High Resolution, 20-100 keV X-ray Backlighters for ICF and HEDS Experiments

    NASA Astrophysics Data System (ADS)

    Park, Hye-Sook; Koch, J. A.; Landen, O. L.; Phillips, T. W.; Schmid, G. J.

    2002-11-01

    We are studying the feasibility of high resolution radiography using short pulse high intensity lasers. Specifically we wish to better characterize and optimize the Kalpha X-ray production and brightness created by relativistic electron plasma interactions in the target material. We plan to utilize this Kalpha source as a backlighter to image various stages of implosions and planar driven high Z materials. Particularly interesting are the production of Kalpha's in the range 20 100 keV. In order to assess in detail the characteristics of such high energy X-ray backlighters, we are performing experiments using the 10 J, 100 fs JanUSP laser at LLNL. We will measure Kalpha source generation efficiency as function of laser beam parameters such as pulse duration, spot size and laser beam energy. We are also developing a high resolution hard X-ray imaging detector system. This paper will present initial results from the JanUSP experiments. Reference:D.K. Bradley, O.L. Landen, A.B. Bullock, S.G. Glendinning, and R.E. Turner, "Efficient, High Spatial-Temporal Resolution, 1-100 keV X-ray Radiography," Opt. Lett. 27(2002) 134.

  2. 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}.

  3. STABILITY OF EXTRATERRESTRIAL GLYCINE UNDER ENERGETIC PARTICLE RADIATION ESTIMATED FROM 2 keV ELECTRON BOMBARDMENT EXPERIMENTS

    SciTech Connect

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

    2015-06-20

    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 CO{sub 2}, CO, OCN{sup −}, and CN{sup −} 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.

  4. 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.

  5. 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.

  6. A comparative study of inelastic scattering models at energy levels ranging from 0.5 keV to 10 keV

    NASA Astrophysics Data System (ADS)

    Hu, Chia-Yu; Lin, Chun-Hung

    2017-03-01

    Six models, including a single-scattering model, four hybrid models, and one dielectric function model, were evaluated using Monte Carlo simulations for aluminum and copper at incident beam energies ranging from 0.5 keV to 10 keV. The inelastic mean free path, mean energy loss per unit path length, and backscattering coefficients obtained by these models are compared and discussed to understand the merits of the various models. ANOVA (analysis of variance) statistical models were used to quantify the effects of inelastic cross section and energy loss models on the basis of the simulated results deviation from the experimental data for the inelastic mean free path, the mean energy loss per unit path length, and the backscattering coefficient, as well as their correlations. This work in this study is believed to be the first application of ANOVA models towards evaluating inelastic electron beam scattering models. This approach is an improvement over the traditional approach which involves only visual estimation of the difference between the experimental data and simulated results. The data suggests that the optimization of the effective electron number per atom, binding energy, and cut-off energy of an inelastic model for different materials at different beam energies is more important than the selection of inelastic models for Monte Carlo electron scattering simulation. During the simulations, parameters in the equations should be tuned according to different materials for different beam energies rather than merely employing default parameters for an arbitrary material. Energy loss models and cross-section formulas are not the main factors influencing energy loss. Comparison of the deviation of the simulated results from the experimental data shows a significant correlation (p < 0.05) between the backscattering coefficient and energy loss per unit path length. The inclusion of backscattering electrons generated by both primary and secondary electrons for

  7. 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.

  8. Comparison between an event-by-event Monte Carlo code, NOREC, and ETRAN for electron scaled point kernels between 20 keV and 1 MeV.

    PubMed

    Cho, Sang Hyun; Vassiliev, Oleg N; Horton, John L

    2007-03-01

    An event-by-event Monte Carlo code called NOREC, a substantially improved version of the Oak Ridge electron transport code (OREC), was released in 2003, after a number of modifications to OREC. In spite of some earlier work, the characteristics of the code have not been clearly shown so far, especially for a wide range of electron energies. Therefore, NOREC was used in this study to generate one of the popular dosimetric quantities, the scaled point kernel, for a number of electron energies between 0.02 and 1.0 MeV. Calculated kernels were compared with the most well-known published kernels based on a condensed history Monte Carlo code, ETRAN, to show not only general agreement between the codes for the electron energy range considered but also possible differences between an event-by-event code and a condensed history code. There was general agreement between the kernels within about 5% up to 0.7 r/r (0) for 100 keV and 1 MeV electrons. Note that r/r (0) denotes the scaled distance, where r is the radial distance from the source to the dose point and r (0) is the continuous slowing down approximation (CSDA) range of a mono-energetic electron. For the same range of scaled distances, the discrepancies for 20 and 500 keV electrons were up to 6 and 12%, respectively. Especially, there was more pronounced disagreement for 500 keV electrons than for 20 keV electrons. The degree of disagreement for 500 keV electrons decreased when NOREC results were compared with published EGS4/PRESTA results, producing similar agreement to other electron energies.

  9. Performance of a medical imaging system for photons in the 60-140 keV energy range

    NASA Astrophysics Data System (ADS)

    Amendolia, S. R.; Bisogni, M. G.; Bottigli, U.; Ceccopieri, A.; Delogu, P.; Dipasquale, G.; Fantacci, M. E.; Maestro, P.; Marchi, A.; Marzulli, V. M.; Oliva, P.; Palmiero, R.; Pernigotti, E.; Rosso, V.; Stefanini, A.; Stumbo, S.

    2001-04-01

    We report the status of the art of a prototype based on a GaAs pixel detector bump-bonded to a dedicated VLSI chip to be possibly used for imaging in the nuclear medicine field. This device, with a 200 μm thick pixel matrix (64×64 square pixels, 170 μm side), has already been tested with very good results for digital mammography applications (mean energy 20 keV). For more energetic photons, as in nuclear medicine, a 600 μm thick detector has been chosen. Using radioactive sources ( 241Am, 60 keV and 99 mTc, 140 keV photons) we have measured the performance of our prototype in terms of charge collection and detection efficiency of the detector, discrimination capability of the electronics and imaging properties of the whole system. In particular, we have evaluated the spatial resolution properties measuring the Point Spread Function and the imaging capabilities using a home made thyroid phantom. We present also the comparison between these results and those obtained with a traditional gamma camera and the evaluation, made by both experimental measurements and software simulations, of the geometry related to the use of a collimator.

  10. The Angular Distribution of Quiet-time ~20-300 keV Superhalo Electrons in the Solar Wind

    NASA Astrophysics Data System (ADS)

    Yang, L.; Wang, L.; He, J.; Tu, C. Y.; Pei, Z.

    2014-12-01

    The angular distribution of solar wind superhalo electrons carries important information on the electron acceleration location and scattering in the interplanetary medium. Here we present a comprehensive study of the angular distribution of ~20-300 keV superhalo electrons measured at 1 AU by the WIND 3DP instrument during quiet-time periods from 1995 January through 2013 December. For quiet-time intervals, we re-bin the observed electron pitch angle distributions into the outward-traveling and inward-traveling bins, according the direction of interplanetary magnetic field (IMF). The inward-outward anisotropy of superhalo electrons at energy E is defined as A = 2(fout - fin)/(fout + fin), where fout (fin) is the average flux of outward-traveling (inward-traveling) electrons. We find that among all the ~640 quiet-time intervals, ~5% have an A > 0.1 (referred to as "outward events"), ~5% have an A < -0.1 (referred to as "inward events"), and ~90% have an |A| ≤ 0.1 (referred to as "isotropic events"). Isotropic events show no clear correlation with solar wind parameters (nSW, Vsw and Tp), IMF and solar wind turbulence spectrum. Inward and outward events also have no association with the IMF and nSW. But the occurrence ratio of outward (inward) events over all the events, α, roughly decreases (increases) with increasing VSW. Moreover, for outward (inward) events, α roughly increases with ρe/ρTp, where ρTp is the solar wind thermal proton gyroradius that is related to the separation between the turbulence inertial and dissipation ranges. These results suggest that quite-time superhalo electrons are generally isotropic due to the wave-particle interaction in the interplanetary medium; outward-traveling (inward-traveling) superhalo electrons may come from the acceleration occurring beyond (within) 1 AU, probably by CIRs or turbulence. We will also present a case study of several quiet-time electron events with the anisotropy A increasing with the electron energy E.

  11. 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.

  12. An X-ray Raman spectrometer for EXAFS studies on minerals: bent Laue spectrometer with 20 keV X-rays.

    PubMed

    Hiraoka, N; Fukui, H; Tanida, H; Toyokawa, H; Cai, Y Q; Tsuei, K D

    2013-03-01

    An X-ray Raman spectrometer for studies of local structures in minerals is discussed. Contrary to widely adopted back-scattering spectrometers using ≤10 keV X-rays, a spectrometer utilizing ~20 keV X-rays and a bent Laue analyzer is proposed. The 20 keV photons penetrate mineral samples much more deeply than 10 keV photons, so that high intensity is obtained owing to an enhancement of the scattering volume. Furthermore, a bent Laue analyzer provides a wide band-pass and a high reflectivity, leading to a much enhanced integrated intensity. A prototype spectrometer has been constructed and performance tests carried out. The oxygen K-edge in SiO(2) glass and crystal (α-quartz) has been measured with energy resolutions of 4 eV (EXAFS mode) and 1.3 eV (XANES mode). Unlike methods previously adopted, it is proposed to determine the pre-edge curve based on a theoretical Compton profile and a Monte Carlo multiple-scattering simulation before extracting EXAFS features. It is shown that the obtained EXAFS features are reproduced fairly well by a cluster model with a minimal set of fitting parameters. The spectrometer and the data processing proposed here are readily applicable to high-pressure studies.

  13. 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.

  14. Two-photon above-threshold ionization of hydrogen over the photon energy range from 15 eV to 50 keV

    SciTech Connect

    Florescu, Viorica; Budriga, Olimpia; Bachau, Henri

    2011-09-15

    We investigate the absorption of two identical photons from the ground state of hydrogen-like atoms over an energy range that extends beyond that explored up to now. Our approach is based on a hybrid formula, valid in second-order perturbation theory, in which the A{sup 2} contribution from the nonrelativistic Hamiltonian is treated exactly, while the A{center_dot}P contribution is calculated in dipole approximation. We find that, at least up to 50 keV, the nonrelativistic dipole approximation, based only on the A{center_dot}P contribution, determines the values of the total cross section. Our numerical results, covering photon energies from 90 nm (13.7 eV) to 0.0248 nm (50 keV) are in very good agreement with most previous theoretical works. Differences with recent results are discussed.

  15. 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.

  16. Multilayer Fresnel zone plates for high energy radiation resolve 21 nm features at 1.2 keV.

    PubMed

    Keskinbora, Kahraman; Robisch, Anna-Lena; Mayer, Marcel; Sanli, Umut T; Grévent, Corinne; Wolter, Christian; Weigand, Markus; Szeghalmi, Adriana; Knez, Mato; Salditt, Tim; Schütz, Gisela

    2014-07-28

    X-ray microscopy is a successful technique with applications in several key fields. Fresnel zone plates (FZPs) have been the optical elements driving its success, especially in the soft X-ray range. However, focusing of hard X-rays via FZPs remains a challenge. It is demonstrated here, that two multilayer type FZPs, delivered from the same multilayer deposit, focus both hard and soft X-rays with high fidelity. The results prove that these lenses can achieve at least 21 nm half-pitch resolution at 1.2 keV demonstrated by direct imaging, and sub-30 nm FWHM (full-pitch) resolution at 7.9 keV, deduced from autocorrelation analysis. Reported FZPs had more than 10% diffraction efficiency near 1.5 keV.

  17. Analysis of 20 KEV Electron Induced X-Ray Production in Skull, Femur/tibia Bones of Rats

    NASA Astrophysics Data System (ADS)

    Mehta, Rahul; Watson, Alec; Ali, Nawab; Soulsby, Michael; Chowdhury, Parimal

    2010-04-01

    Hind-limb suspension (HLS) of rats is a NASA validated model of simulated weightlessness. This study examines the effects of microgravity on the skeletal system of rats to assess whether or not exposure of rats to HLS for one week will induce alteration of structural features in selected bones. Four groups of rats were used: two unsuspended controls and two suspended groups. Body weight, food, and water intake were monitored daily before and after suspension. X-rays were measured by a liquid nitrogen cooled Si(li) detector on a Scanning Electron Microscope (SEM) that provided the 20 keV electron beam. X-ray data were collected from square cross sections between 100 μm2 and 104 μm2. The bones were measured for elemental levels of calcium, phosphorus, oxygen and carbon from both control and HLS rats. The average body weight of all HLS groups decreased compared to their respective unsuspended controls. Food and water intake was also lower in both suspended groups. A correlation among HLS and control samples in terms of the distribution of the primary elements was found in the bone tissue when analyzed as a function of position along the hind-leg and within the cross sections.

  18. High Spatial Resolution STXM at 6.2 keV Photon Energy

    SciTech Connect

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

    2010-04-06

    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.

  19. 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.

  20. Gamma ray interaction studies of organic nonlinear optical materials in the energy range 122 keV-1330 keV

    NASA Astrophysics Data System (ADS)

    Awasarmol, V. V.; Gaikwad, D. K.; Raut, S. D.; Pawar, P. P.

    The mass attenuation coefficients (μm) for organic nonlinear optical materials measured at 122-1330 keV photon energies were investigated on the basis of mixture rule and compared with obtained values of WinXCOM program. It is observed that there is a good agreement between theoretical and experimental values of the samples. All samples were irradiated with six radioactive sources such as 57Co, 133Ba, 22Na, 137Cs, 54Mn and 60Co using transmission arrangement. Effective atomic and electron numbers or electron densities (Zeff and Neff), molar extinction coefficient (ε), mass energy absorption coefficient (μen/ρ) and effective atomic energy absorption cross section (σa,en) were determined experimentally and theoretically using the obtained μm values for investigated samples and graphs have been plotted. The graph shows that the variation of all samples decreases with increasing photon energy.

  1. Mass attenuation coefficient of the Earth, Moon and Mars samples over 1keV-100GeV energy range.

    PubMed

    Camargo Moreira, Anderson; Roberto Appoloni, Carlos

    2006-09-01

    This work presents the calculation of the mass attenuation coefficient (micro) of lunar, Martian and terrestrial samples in function of the energy. WinXCOM software was employed to determine the micro values for the samples in the range from 1 keV to 100 GeV. The obtained values were practically the same for energies larger than 100 keV, but marked differences among the samples were observed for energies below 25 keV, which is the energy range of interest for the XRF system used in space probes.

  2. Measurement of 2-5 keV x-ray emission from laser-target interactions by using fluor-MCP and CsI-XRD detectors

    SciTech Connect

    Lee, P.H.Y.; Tirsell, K.G.; Leipelt, G.R.; Laird, W.B.

    1981-09-29

    For inertial confinement fusion plasma diagnostics, x-ray diode (XRD) detectors using conventional cathodes are not sensitive enough to measure x-rays above approx. 1.5 keV. However, for laser driver fusion targets, x-rays in the range of 2 to 5 keV are important because of their mobility in the target. We have successfully used fluor-microchannel plate (MCP) detectors to obtain absolute x-ray measurements in the 2 to 5 keV range. Recent data obtained from experiments on the Shiva laser system are presented. In addition, designs for a variety of channels in the range using fluor-MCP and CsI-XRD's above 1.5 keV will be discussed.

  3. 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.

  4. 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

    2011-02-07

    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.

  5. SURVIVAL DEPTH OF ORGANICS IN ICES UNDER LOW-ENERGY ELECTRON RADIATION ({<=}2 keV)

    SciTech Connect

    Barnett, Irene Li; Lignell, Antti; Gudipati, Murthy S.

    2012-03-01

    Icy surfaces in our solar system are continually modified and sputtered with electrons, ions, and photons from solar wind, cosmic rays, and local magnetospheres in the cases of Jovian and Saturnian satellites. In addition to their prevalence, electrons specifically are expected to be a principal radiolytic agent on these satellites. Among energetic particles (electrons and ions), electrons penetrate by far the deepest into the ice and could cause damage to organic material of possible prebiotic and even biological importance. To determine if organic matter could survive and be detected through remote sensing or in situ explorations on these surfaces, such as water ice-rich Europa, it is important to obtain accurate data quantifying electron-induced chemistry and damage depths of organics at varying incident electron energies. Experiments reported here address the quantification issue at lower electron energies (100 eV-2 keV) through rigorous laboratory data analysis obtained using a novel methodology. A polycyclic aromatic hydrocarbon molecule, pyrene, embedded in amorphous water ice films of controlled thicknesses served as an organic probe. UV-VIS spectroscopic measurements enabled quantitative assessment of organic matter survival depths in water ice. Eight ices of various thicknesses were studied to determine damage depths more accurately. The electron damage depths were found to be linear, approximately 110 nm keV{sup -1}, in the tested range which is noticeably higher than predictions by Monte Carlo simulations by up to 100%. We conclude that computational simulations underestimate electron damage depths in the energy region {<=}2 keV. If this trend holds at higher electron energies as well, present models utilizing radiation-induced organic chemistry in icy solar system bodies need to be revisited. For interstellar ices of a few micron thicknesses, we conclude that low-energy electrons generated through photoionization processes in the interstellar medium

  6. 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.

  7. Measurement of the mass energy-absorption coefficient of air for x-rays in the range from 3 to 60 keV.

    PubMed

    Buhr, H; Büermann, L; Gerlach, M; Krumrey, M; Rabus, H

    2012-12-21

    For the first time the absolute photon mass energy-absorption coefficient of air in the energy range of 10 to 60 keV has been measured with relative standard uncertainties below 1%, considerably smaller than those of up to 2% assumed for calculated data. For monochromatized synchrotron radiation from the electron storage ring BESSY II both the radiant power and the fraction of power deposited in dry air were measured using a cryogenic electrical substitution radiometer and a free air ionization chamber, respectively. The measured absorption coefficients were compared with state-of-the art calculations and showed an average deviation of 2% from calculations by Seltzer. However, they agree within 1% with data calculated earlier by Hubbell. In the course of this work, an improvement of the data analysis of a previous experimental determination of the mass energy-absorption coefficient of air in the range of 3 to 10 keV was found to be possible and corrected values of this preceding study are given.

  8. Strength of the Ec.m.=1113 keV resonance in 20Ne(p,γ)21Na

    NASA Astrophysics Data System (ADS)

    Christian, G.; Hutcheon, D.; Akers, C.; Connolly, D.; Fallis, J.; Ruiz, C.

    2013-09-01

    The 20Ne(p,γ)21Na reaction is the starting point of the NeNa cycle, which is an important process for the production of intermediate mass elements. The Ec.m.=1113 keV resonance plays an important role in the determination of stellar rates for this reaction since it is used to normalize experimental direct capture yields at lower energies. The commonly accepted strength of this resonance, ωγ=1.13±0.07 eV, has been misinterpreted as the strength in the center-of-mass frame when it is actually the strength in the laboratory frame. This has motivated a new measurement of the Ec.m.=1113 keV resonance strength in 20Ne(p,γ)21Na using the DRAGON recoil mass spectrometer. The DRAGON result, 0.972±0.11 eV, is in good agreement with the accepted value when both are calculated in the same frame of reference.

  9. 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.

  10. Demonstration of Airborne Wide Area Assessment Technologies at Pueblo Precision Bombing Ranges, Colorado. Hyperspectral Imaging, Version 2.0

    DTIC Science & Technology

    2007-09-27

    NDVI ) is calculated as [NIR – RED]/[NIR + RED] and the Water Indices are simple ratios of reflectance within key water absorption spectral ranges...Normalized Difference Vegetation Index ( NDVI ) is calculated as [NIR – RED]/[NIR + RED] and the Water Indices are simple ratios of reflectance within key

  11. Photon interaction study of organic nonlinear optical materials in the energy range 122-1330 keV

    NASA Astrophysics Data System (ADS)

    Awasarmol, Vishal V.; Gaikwad, Dhammajyot K.; Raut, Siddheshwar D.; Pawar, Pravina P.

    2017-01-01

    In the present study, the mass attenuation coefficient (μm) of six organic nonlinear optical materials has been calculated in the energy range 122-1330 keV and compared with the obtained values from the WinXCOM program. It is found that there is a good agreement between theoretical and experimental values (<3%). The linear attenuation coefficients (μ) total atomic cross section (σt, a), and total electronic cross section (σt, el) have also been calculated from the obtained μm values and their variations with photon energy have been plotted. From the present work, it is observed that the variation of obtained values of μm, μ, σt, a, and σt, el strongly depends on the photon energy and decreases or increases due to chemical composition and density of the sample. All the samples have been studied extensively using transmission method with a view to utilize the material for radiation dosimetry. Investigated samples are good material for radiation dosimetry due their low effective atomic number. The mass attenuation coefficient (μm), linear attenuation coefficients (μ), total atomic cross section (σt, a), total electronic cross section (σt, el), effective atomic numbers (Zeff), molar extinction coefficient (ε), mass energy absorption coefficient (μen/ρ) and effective atomic energy absorption cross section (σa, en) of all sample materials have been carried out and transmission curves have been plotted. The transmission curve shows that the variation of all sample materials decreases with increasing photon energy.

  12. 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.

  13. 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.

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

    DOE PAGES

    Diakaki, M.; Karadimos, D.; Vlastou, R.; ...

    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

  15. 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.

  16. Low-temperature volume radiation annealing of cold-worked bands of Al-Li-Cu-Mg alloy by 20-40 keV Ar+ ion

    NASA Astrophysics Data System (ADS)

    Ovchinnikov, V. V.; Gushchina, N. V.; Mozharovsky, S. M.; Kaigorodova, L. I.

    2017-01-01

    The processes of radiation-dynamic nature (in contrast to the thermally-activated processes) in the course of short-term irradiation of 1 mm thick bands of cold-worked aluminum alloy 1441 (of system Al-Li-Cu-Mg) with Ar+ 20-40 keV were studied. An effect of in-the-bulk (throughout the whole of metal bands thickness) low-temperature radiation annealing of the named alloy, multiply accelerated as compared with common thermal annealing processes was registered (with projected ranges of ions of considered energies definitely not exceeding 0.1 μm). The processes of recrystallization and intermetallic structure changes (occurring within a few seconds of Ar+ irradiation) have the common features as well as the differences in comparison with the results of two hour standard thermal annealing.

  17. Measurement of mass attenuation coefficients of Eremurus-Rhizophora spp. particleboards for X-ray in the 16.63-25.30 keV energy range

    NASA Astrophysics Data System (ADS)

    Tousi, E. T.; Bauk, S.; Hashim, R.; Jaafar, M. S.; Abuarra, A.; Aldroobi, K. S. A.; Al-Jarrah, A. M.

    2014-10-01

    The roots of Eremurus spp. were used as a bio-adhesive in the fabrication of Rhizophora spp. particleboards. The mass attenuation coefficients of Eremurus-Rhizophora spp. particleboard of six samples with two different weight percentages of the Eremurus spp. root (6% and 12%) and three various Rhizophora spp. particle sizes (≤149 μm, 149-500 μm and 500-1000 μm) were determined by using X-ray fluorescence (XRF) photons in 16.63 keV and 25.30 keV of the photon energy range. The results were compared with theoretically calculated mass attenuations using the XCOM computer program for younger-age (breast 1: 75% muscle+25% fat), middle-age (breast 2: 50% muscle+50% fat), and old-age (breast 3: 25% muscle+75% fat) breasts. The results indicated that Eremurus-Rhizophora spp. particleboard is the appropriate suitable phantom in the diagnostic energy region. The mass attenuation coefficient in the low weight percentage of the bio-adhesive and the large Rhizophora spp. particle size were found very close to breast 1. Moreover the mass attenuation coefficient of the sample with high weight percentage of the bio-adhesive and small Rhizophora spp. particle size was found very close to water as a standard material phantom. In addition, the viscosity of dissolved Eremurus spp. root in water could be considerably higher than that of formaldehyde-based adhesives, which affects on some properties such as high strength and high binding.

  18. Gamma-ray bursts investigations: perspectives for the GAMMA-400 space experiment in the energy range of 100 keV-3 TeV

    NASA Astrophysics Data System (ADS)

    Arkhangelskaja, Irene; Yurkin, Yuri T.; Arkhangelsky, Andrey; Topchiev, Nikolay; Kheymits, Maxim; Runtso, Mikhail; Suchkov, Sergey; Galper, Arkady

    Several thousands of gamma-ray bursts were observed by various experiments, but their sources origin still remains unclear up to now. During several GRBs very high-energy photons were detected both in space and ground-based experiments (up to some tens of GeV and up to some TeV, respectively). The GAMMA-400 future space experiment consists of the GAMMA-400 gamma-ray telescope to detect gammas in the energy range of 100 MeV - 3 TeV and the KONUS-FG system to detect gamma-ray bursts in the range of 100 keV - 10 MeV similar to the KONUS/WIND instrument. The GAMMA-400 gamma-ray telescope will have the angular resolution of 0.02 deg for E > 100 GeV, the energy resolution of 2% for E > 10 GeV, time resolution of ˜ 0.1 ms and allow us together with KONUS-FG to investigate GRBs spectra and temporal profiles in details in the wide energy range.

  19. 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.

  20. The 2-10 keV X-Ray Background Dipole and Its Cosmological Implications

    NASA Astrophysics Data System (ADS)

    Scharf, C. A.; Jahoda, K.; Treyer, M.; Lahav, O.; Boldt, E.; Piran, T.

    2000-11-01

    The hard X-ray (>2 keV) emission of the local and distant universe as observed with the HEAO 1 A-2 experiment is reconsidered in the context of large-scale cosmic structure. Using all-sky X-ray samples of active galactic nuclei (AGNs) and galaxy clusters, we remove the dominant local X-ray flux from within a redshift of ~0.02. We evaluate the dipolar and higher order harmonic structure in four X-ray colors. The estimated dipole anisotropy of the unresolved flux appears to be consistent with a combination of the Compton-Getting effect due to the Local Group motion (dipole amplitude Δ=0.0042) and remaining large-scale structure (0.0023<~Δ<~0.0085), in good agreement with the expectations of cold dark matter models. The observed anisotropy does, however, also suggest a nonnegligible Galactic contribution that is more complex than current, simple models of >2 keV Galactic X-ray emission. Comparison of the soft and hard color maps with a harmonic analysis of the 1.5 keV ROSAT all-sky data qualitatively suggests that at least a third of the faint, unresolved ~18° scale structure in the HEAO 1 A-2 data may be Galactic in origin. However, the effect on measured flux dipoles is small (<~3%). We derive an expression for dipole anisotropy and acceleration and demonstrate how the dipole anisotropy of the distant X-ray frame can constrain the amplitude of bulk motions of the universe. From observed bulk motions over a local ~50 h-1 Mpc radius volume, we determine 0.14<~Ω0.60/bX(0)<~0.59, where Ω0 is the universal density parameter and bX(0) is the present-epoch bias parameter, defined as the ratio of fluctuations in the X-ray source density and the mass density.

  1. An improved long counter for neutron fluence measurement with a flat response over a wide energy range from 1 keV to 15 MeV

    NASA Astrophysics Data System (ADS)

    Hu, Q. Y.; Zhang, J. H.; Zhang, D.; Guo, H. S.; Yang, G. Z.; Li, B. J.; Ye, F.; Si, F. N.; Liu, J.; Fu, Y. C.; Ning, J. M.; Yang, J.; Yang, H. H.; Wang, W. C.

    2014-12-01

    A new long counter has been developed with a flat energy response over a wide range from 1 keV to 15 MeV. It consists of five 3He proportional counter tubes and a number of carefully designed polyethylene moderators. The structure of this detector was determined by careful Monte Carlo simulations. The calculated results show that the efficiency of this counter is uniform from 1 keV neutron energy to 15 MeV. Calibration was performed on an Am-Be source and the accelerator-produced monoenergetic D-D and D-T neutron sources. Fluctuation of the response curve is less than 10% over this energy range.

  2. 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

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

    NASA Astrophysics Data System (ADS)

    O'Dell, Stephen L.; Ramsey, B. D.; Adams, M. L.; Areviev, V.; Brandt, W. N.; Buntov, M.; Elsner, R. F.; Grigorovich, S.; Gubarev, M. V.; Hasinger, G.; Lapshov, I.; Litvin, D.; Meidinger, N.; Pavlinsky, M.; Predehl, P.; Revnivtsev, M.; Romaine, S. E.; Sazonov, S.; Semena, N.; Swartz, D. A.; Tkachenko, A.; Urry, C. M.; Vikhlinin, A.; Weisskopf, M. C.

    2008-03-01

    The Astronomical Röntgen Telescope (ART) is a medium-energy x-ray telescope system proposed for the Russian-led mission Spectrum Röntgen-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 about 1,000 heavily-obscured (NH > 3×1023 cm-2) active galactic nuclei (AGN) - in the SRG 4-year all-sky survey, plus a comparable number in deeper wide-field (500 deg2 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 (�-ks) pointed observations, ART can obtain statistically significant spectral data up to about 15 keV 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.

  4. Airborne 2 color ranging experiment

    NASA Technical Reports Server (NTRS)

    Millar, Pamela S.; Abshire, James B.; Mcgarry, Jan F.; Zagwodzki, Thomas W.; Pacini, Linda K.

    1993-01-01

    Horizontal variations in the atmospheric refractivity are a limiting error source for many precise laser and radio space geodetic techniques. This experiment was designed to directly measure horizontal variations in atmospheric refractivity, for the first time, by using 2 color laser ranging measurements to an aircraft. The 2 color laser system at the Goddard Optical Research Facility (GORF) ranged to a cooperative laser target package on a T-39 aircraft. Circular patterns which extended from the southern edge of the Washington D.C. Beltway to the southern edge of Baltimore, MD were flown counter clockwise around Greenbelt, MD. Successful acquisition, tracking, and ranging for 21 circular paths were achieved on three flights in August 1992, resulting in over 20,000 two color ranging measurements.

  5. 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.

  6. Echo 2 - Observations at Fort Churchill of a 4-keV peak in low-level electron precipitation

    NASA Technical Reports Server (NTRS)

    Arnoldy, R. L.; Hendrickson, R. A.; Winckler, J. R.

    1975-01-01

    The Echo 2 rocket flight launched from Fort Churchill, Manitoba, offered the opportunity to observe high-latitude low-level electron precipitation during quiet magnetic conditions. Although no visual aurora was evident at the time of the flight, an auroral spectrum sharply peaked at a few keV was observed to have intensities from 1 to 2 orders of magnitude lower than peaked spectra typically associated with bright auroral forms. There is a growing body of evidence that relates peaked electron spectra to discrete aurora. The Echo 2 observations show that whatever the mechanism for peaking the electron spectrum in and above discrete forms, it operates over a range of precipitation intensities covering nearly 3 orders of magnitude down to subvisual or near subvisual events.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. The production and sputtering of S2 by keV ion bombardment

    NASA Technical Reports Server (NTRS)

    Boring, J. W.; Chrisey, D. B.; Oshaughnessy, D. J.; Phipps, J. A.; Zhao, N.

    1986-01-01

    The ion bombardment of S-containing molecules in comets is simulated experimentally. Mass-analyzed 30-keV beams of Ar(+) and He(+) are directed at solid S, H2S, and CS2 targets at temperatures 15 K, and the neutral molecular species produced are ionized and analyzed using a quadrupole mass spectrometer. The dominant species detected are S1 and S2 for the S target, H2S and S2 for the H2S target, and S, CS, S2, and CS2 for the CS2 target. In the latter case, it is found that after about 10 to the 14th He(+) ions/sq cm have struck the target, further sputtering is prevented by formation of a dark brown deposit which is stable at room temperature; the residue forms more slowly when Ar(+) ions are used. These results, indicating relatively efficient S2 production by ion bombardment, are applied to theoretical models of S2 production and/or ejection by solar-wind, solar-flare, or cosmic-ray ions striking comets. It is found that direct solar-wind production of S2 by sputtering is unlikely at realistic bombardment rates, but that H2S-S2 conversion by energetic ions could be significant, with less stringent ice-temperature and irradiation-flux constraints than in the case of S2 production by photons.

  12. Study of effective atomic number and electron density for tissues from human organs in the energy range of 1 keV-100 GeV.

    PubMed

    Manjunatha, H C; Rudraswamy, B

    2013-02-01

    Effective atomic numbers' (Z(eff)) effective electron density (N(el)) for human organs and tissues have been computed in the energy region of 1 keV to 100 GeV using WinXCOM. The computed data of Z(eff) and N(el) are tabulated. The computed values are compared with previous results. The computed data of Z(eff)and N(el)for almost all tissues (34 tissues of different human organs) in the given energy range are not available in literature and find application in radiotherapy and dosimetry.

  13. Electron capture in Ar++H2 collisions in the keV energy regime

    NASA Astrophysics Data System (ADS)

    Kimura, M.; Chapman, S.; Lane, N. F.

    1986-03-01

    Electron capture in Ar+( 2P)+H2(X 1Σg) collisions in the keV energy regime has been studied theoretically. The molecular-orbital expansion method was used within a semiclassical formalism and an electron translation factor correction was incorporated to the first order in the magnitude of the relative velocity V. The molecular wave function and eigenenergy were obtained using the diatoms-in-molecules (DIM) method. We have examined the effect of the orientation of the target H2 molecule on the electron-capture mechanism within the sudden adiabatic approximation. Since π symmetry arising from the p orbital of the Ar+ ion is involved in this system, a strong influence on the probability of the molecular orientation was found in all energies studied. As the collision energy increases, the Π-symmetry state in the initial channel becomes more important through the rotational coupling to the electron-capture mechanism, while at lower energies the Σ-symmetry state in the initial channel is the dominant source for the electron capture through strong radial coupling. Agreement of the present theory with measurements is good, but marked disagreement is seen with the atomic-orbital calculation.

  14. Synthetic multilayer x-ray dispersion elements for 200 A (62 eV) to 0. 62 A (20 keV) radiation. Final report

    SciTech Connect

    Barbee, T.W. Jr.

    1983-11-01

    This final report concerns research performed at Stanford University on a program sponsored by the Department of Energy through Lawrence Livermore National Laboratory and the Regents of the University of California (Subcontract No. 2695501) entitled Synthetic Multilayer X-ray Dispersion Elements for 200 A (62 eV) to 0.62 A (20 keV) Radiation. The thrust of the research was to investigate the synthesis process parameter dependence of the nature of the interfaces between constituent adjacent layers, the uniformity of layers, and the reflectivity for light of wavelengths 0.62 A to 200 A of synthetic multilayer crystals. Additionally, device development was to be undertaken with emphasis on spectrum analyzing dispersion elements, high energy Kirkpatrick-Baez X-ray microscope mirrors, multi-keV (1 to 5 keV) X-ray applications, X-ray beam splitters and synthetic multilayers fabricated from adjoining elements in the periodic table.

  15. A satellite-borne ion mass spectrometer for the energy range 0 to 16 keV

    NASA Technical Reports Server (NTRS)

    Balsiger, H.; Eberhardt, P.; Geiss, J.; Ghielmetti, A.; Walker, H. P.; Young, D. T.; Loidl, H.; Rosenbauer, H.

    1976-01-01

    The Ion Composition Experiment (ICE) on GEOS represents the first comprehensive attempt to measure the positive ion composition at high altitudes in the magnetosphere. Due to the heterogeneous nature of the magnetospheric plasma a novel mass spectrometer has been developed to cover the mass per charge range from H-1(+) to beyond Ba-138(+) and the energy per charge range from 0 to 16 keV/e. The ICE consists primarily of a cylindrical electrostatic analyzer followed by a curved analyzer incorporating crossed magnetic and electric fields. This combination has limited angular and energy focusing properties, but it maintains a mass resolution of about 4 over a wide range in energy and mass, sufficient for the objectives of measuring plasmas of both solar and terrestrial origin. High sensitivity and low background should allow measurements of rarer ion constituents down to flux levels of 0.01 ions/sq cm sec ster eV. A sophisticated electronics combined with powerful ground computer and telecommand systems allow for very efficient scanning of the mass-energy space.

  16. Anomalous X-ray galactic signal from 7.1 keV spin-3/2 dark matter decay

    SciTech Connect

    Dutta, Sukanta; Goyal, Ashok; Kumar, Sanjeev E-mail: agoyal45@yahoo.com

    2016-02-01

    In order to explain the recently reported peak at 3.55 keV in the galactic X-ray spectrum, we propose a simple model. In this model, the Standard Model is extended by including a neutral spin-3/2 vector-like fermion that transforms like a singlet under SM gauge group. This 7.1 keV spin-3/2 fermion is considered to comprise a portion of the observed dark matter. Its decay into a neutrino and a photon with decay life commensurate with the observed data, fits the relic dark matter density and obeys the astrophysical constraints from the supernova cooling.

  17. 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.

  18. 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.

  19. 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.

  20. A 7.2 keV spherical crystal backlighter system for Sandia's Z Pulsed Power Facility

    NASA Astrophysics Data System (ADS)

    Schollmeier, M.; Knapp, P. F.; Ampleford, D. J.; Loisel, G. P.; Robertson, G.; Shores, J. E.; Smith, I. C.; Speas, C. S.; Porter, J. L.; McBride, R. D.

    2016-10-01

    Many experiments on Sandia's Z facility, a 30 MA, 100 ns rise-time, pulsed-power driver, use a monochromatic Quartz crystal imaging backlighter system at 1.865 keV (Si Heα) or 6.151 keV (Mn Heα) x-ray energy to radiograph an imploding liner (cylindrical tube) or wire array. The x-ray source is generated by the Z-Beamlet Laser (ZBL), which provides up to 4.5 kJ at 527 nm during a 6 ns window. Radiographs of an imploding thick-walled Beryllium liner at a convergence ratio of about 20 [CR =Rin . (0) /Rin . (t) ] were too opaque to identify the inner surface of the liner with high confidence, demonstrating the need for a higher-energy x-ray backlighter between 6 and 10 keV. We present the design, test and first application of a Ge (335) spherical crystal x-ray backlighter system using the 7.242 keV Co Heα resonance line. The system operates at an almost identical Bragg angle as the existing 1.865 and 6.151 keV backlighters, enhancing our capabilities such as two-color, two-frame radiography, without changing detector shielding hardware. SAND No: SAND2016-6724 A. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corp., a wholly owned subsidiary of Lockheed Martin Corp., for the U.S. DoE NNSA under contract DE-AC04-94AL85000.

  1. 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.

  2. 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.

  3. 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.

  4. Experimental binding energies for the metal complexes [Mg(CH3OH)n](2+), [Ca(CH3OH)n](2+), and [Sr(CH3OH)n](2+) for n in the range 4-20.

    PubMed

    Bruzzi, E; Stace, A J

    2014-10-09

    A supersonic source of clusters has been used to prepare neutral complexes of methanol in association with an alkaline earth metal atom. From these complexes the following metal-containing dications have been generated through electron ionization: [Mg(CH3OH)n](2+), [Ca(CH3OH)n](2+), and [Sr(CH3OH)n](2+), and for n in the range 4-20, kinetic energy release measurements following the evaporation of a single molecule have been undertaken using a high resolution mass spectrometer. Using finite heat bath theory, these data have been transformed into binding energies for individual methanol molecules attached to each of the three cluster systems. In the larger complexes (n > 6) the results exhibit a consistent trend, whereby the experimental binding energy data for all three metal ions are similar, suggesting that the magnitude of the charge rather than charge density influences the strength of the interaction. From a comparison with data recorded previously for (CH3OH)nH(+) it is found that the 2+ charge on a metal ion has an effect on the binding energy of molecules in complexes containing up to 20 solvent molecules. The results recorded for [Ca(CH3OH)n](2+) show evidence of a very marked transition between n = 6 and 7, which is thought to coincide with the completion of a primary solvation shell and the onset of molecules starting to occupy a second and most probably a third shell.

  5. Web 2.0

    NASA Astrophysics Data System (ADS)

    Gibson, Becky

    The Web is growing and changing from a paradigm of static publishing to one of participation and interaction. This change has implications for people with disabilities who rely on access to the Web for employment, information, entertainment, and increased independence. The interactive and collaborative nature of Web 2.0 can present access problems for some users. There are some best practices which can be put in place today to improve access. New specifications such as Accessible Rich Internet Applications (ARIA) and IAccessible2 are opening the doors to increasing the accessibility of Web 2.0 and beyond.

  6. New XAFS spectroscopic investigations in the 1-2 keV region. Final report on LDRD program

    SciTech Connect

    Wong, J.; Froba, M.; Tamura, E.

    1996-03-01

    Until recently x-ray absorption fine structure (XAFS) measurements in the 1-2 keV region remained a challenging experimental task. This was primarily due to the lack of an adequate monochromator crystal that possessed both the required x-ray properties (large d-spacing, high resolution and reflectivity) and materials properties (ultra-high vacuum (UHV) capability, damage resistance in a synchrotron radiation beam, absence of constituent element absorption edges and stability, both thermal and mechanical). Traditionally, XAFS spectra in this photon energy range have been measured in a piece-wise fashion using a combination of monochromator crystals. Very recently, we have an experimental breakthrough in XAFS spectroscopy in this soft x-ray region. This energy region is of great importance for materials and basic research since the K-edges of Na (1070 eV), Mg (1303 eV), Al (1557 eV) and Si (1839 eV), the L-edges of some 4p elements from Ga to Sr and the M-edges of the rare-earth elements fall within this energy window of the electromagnetic spectrum. YB{sub 66}, a complex binary semiconducting yttrium boride having a cubic crystal structure with a lattice constant of 23.44 {angstrom} has been singled out as a candidate monochromator material for synchrotron radiation in the 1-2 keV region. There is no intrinsic absorption by the constituent elements in this region, which can adequately be dispersed by the (400) reflection having a 2d value of 11.76 {angstrom}. In terms of vacuum compatibility, resistance to radiation damage, thermal and mechanical stability, YB{sub 66} satisfies all the material requirements for use as a monochromator in a synchrotron beam. In the past few years, LLNL in collaboration with a number of other research institutes has pioneered the development of this unique man-made crystal for use as soft x-ray monochromator with synchrotron light sources for materials science studies. 23 refs., 4 figs.

  7. 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.

  8. Measurement of the e+e-→K+K- cross section in the energy range √{s }=1.05 -2.0 GeV

    NASA Astrophysics Data System (ADS)

    Achasov, M. N.; Aulchenko, V. M.; Barnyakov, A. Yu.; Barnyakov, M. Yu.; Beloborodov, K. I.; Berdyugin, A. V.; Berkaev, D. E.; Bogdanchikov, A. G.; Botov, A. A.; Buzykaev, A. R.; Dimova, T. V.; Druzhinin, V. P.; Golubev, V. B.; Kardapoltsev, L. V.; Kharlamov, A. G.; Kononov, S. A.; Koop, I. A.; Korol, A. A.; Koshuba, S. V.; Kovrizhin, D. P.; Kravchenko, E. A.; Kupich, A. S.; Lysenko, A. P.; Martin, K. A.; Obrazovsky, A. E.; Onuchin, A. P.; Otboyev, A. V.; Pakhtusova, E. V.; Perevedentsev, E. A.; Rogovsky, Yu. A.; Serednyakov, S. I.; Shatunov, Yu. M.; Shatunov, P. Yu.; Shtol, D. A.; Silagadze, Z. K.; Skrinsky, A. N.; Surin, I. K.; Tikhonov, Yu. A.; Usov, Yu. V.; Vasiljev, A. V.; Zemlyansky, I. M.

    2016-12-01

    The e+e-→K+K- cross section is measured in the center-of-mass energy range 1.05-2.00 GeV at the SND detector. The measurement is based on data with an integrated luminosity of 35 pb-1 collected at the VEPP-2000 e+e--collider. The obtained results are consistent with the previous most accurate data obtained in the BABAR experiment and have a comparable accuracy.

  9. 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)…

  10. 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).

  11. 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.

  12. 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.

  13. 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).

  14. COCO, a Compton coincidence experiment to study liquid scintillator response in the 1-20 keV energy range

    NASA Astrophysics Data System (ADS)

    Péron, M. N.; Cassette, P.

    1994-12-01

    The use of Liquid Scintillation Counting (LSC) as a fundamental radionuclide standardisation method requires a correct description of the physical phenomena occurring during the LSC process. In that framework, a special point of interest is the description of the liquid scintillator response, especially for low-energy electrons, in a region where this response is known to be non-linear. As there is no simple way to produce monoenergetic electrons in the liquid scintillator, we have simulated these electrons using a Compton interaction coincidence method. Due to the energy conservation law, the selection of the energy of the scattered Compton X-ray photon is equivalent to the selection of the energy of a monoenergetic electron. This paper describes the experimental system and the methods used to analyse the experimental results in order to deduce the statistical distribution of the photons emitted by the scintillator. The effects of some artefacts are discussed, including the accidental coincidences and the influence of cascade Compton interactions.

  15. Albedo factors of some elements in the atomic number range 26≤Z≤79 for 59.54keV.

    PubMed

    Yılmaz, Demet; Uzunoğlu, Zeynep; Demir, Celalettin

    2017-04-01

    In this study, we aimed to determine the albedo factors for Fe, Co, Ni, Cu, Zr, Mo, Ag, Dy, Yb, and Au. Albedo factors were investigated experimentally for 59.54keV photon energy by using an HPGe detector with a resolution of 182eV at 5.9keV. Albedo number (AN), albedo energy (AE), and albedo dose (AD) were plotted as a function of atomic number of the target. It was observed that albedo factors decreased with increasing atomic number. In addition, there was a good third-order polynomial relationship between the albedo factors and atomic number.

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

    SciTech Connect

    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.

    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, and the model parameters were tuned in order to successfully reproduce the experimental fission cross-sectional data and simultaneously all the competing reaction channels.

  17. 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 29-60keV

    NASA Astrophysics Data System (ADS)

    de Jonge, Martin D.; Tran, Chanh Q.; Chantler, Christopher T.; Barnea, Zwi; Dhal, Bipin B.; Paterson, David; Kanter, Elliot P.; Southworth, Stephen H.; Young, Linda; Beno, Mark A.; Linton, Jennifer A.; Jennings, Guy

    2007-03-01

    We use the x-ray extended-range technique (XERT) [C. T. Chantler , Phys. Rev. A 64, 062506 (2001)] to measure the mass attenuation coefficients of tin in the x-ray energy range of 29-60keV 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 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 1-2% persist between calculated and observed values.

  18. 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.

  19. 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

  20. 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

  1. Interaction of 18-keV O{sup -} ions with Al{sub 2}O{sub 3} nanocapillaries

    SciTech Connect

    Sun Guangzhi; Chen Ximeng; Wang Jun; Chen Yifeng; Xu Junkui; Zhou Chunlin; Shao Jianxiong; Cui Ying; Ding Baowei; Yin Yongzhi; Wang Xinan; Lou Fengjun; Lv Xueyang; Qiu Xiyu; Jia Juanjuan; Chen Lin; Xi Fayuan; Chen Zichun; Li Lanting; Liu Zhaoyuan

    2009-05-15

    The transmission of 18-keV O{sup -} ions through Al{sub 2}O{sub 3} nanocapillaries with 50 nm in diameter and 12 {mu}m in length is studied in this work. By measuring angular distribution of transmitted particles when capillaries were tilted with respect to incident ion beam, two peaks were observed. It is distinguished that one of them is composed by direct transmitted ions and another one is composed by scattered ions. A phenomenon referred to as guiding effect, as found for highly charged ions and low-energy electrons, was observed. When negative ions (18-keV O{sup -}) are transmitted through nanocapillaries, most of them were ionized to neutral atoms and even positive ions. The intensity of transmitted particles (O{sup -}, O{sup 0}, and O{sup +}) decreased when the tilt angle increased. In transmitted particles, the fraction of O{sup -} declined but that of O{sup 0} and O{sup +} ions grew when the tilt angle grew. Both elastic collision and electrostatic scattering were found in scattered ions.

  2. Analysis of photon emission from 50--350-keV proton impact on H2O

    NASA Astrophysics Data System (ADS)

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

    2011-04-01

    We have measured photon emission cross sections from neutral fragments produced by collisions of 50-350 keV protons with H2O molecules. Balmer α-δ emissions from both the target and projectile were recorded. We also analyzed A2Σ+-X2Π (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.

  3. CO2 synthesis in solid CO by Lyman-α photons and 200 keV protons

    NASA Astrophysics Data System (ADS)

    Loeffler, M. J.; Baratta, G. A.; Palumbo, M. E.; Strazzulla, G.; Baragiola, R. A.

    2005-05-01

    We have studied the synthesis of carbon dioxide from solid carbon monoxide at 16 K induced by photolysis with Lyman-α photons and by irradiation with 200 keV protons to quantitatively compare the effects of photolysis and ion irradiation on CO ice and to determine the importance of these processes in interstellar ice grains. The CO and CO{2} concentrations during irradiation of an initially pure CO film evolve with fluence to a saturation value, a behaviour that is explained by a two-state model. Our results indicate that the initial CO{2} production rates for both radiation processes are similar when normalized to the absorbed energy and that the solid CO{2} abundance observed in the interstellar ices cannot be explained only by radiolysis and photolysis of pure solid CO.

  4. 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.

  5. Predictive value of [-2]propsa (p2psa) and its derivatives for the prostate cancer detection in the 2.0 to 10.0ng/mL PSA range

    PubMed Central

    Vukovic, I.; Djordjevic, D.; Bojanic, N.; Babic, U.; Soldatovic, I.

    2017-01-01

    ABSTRACT Introduction To assess predictive value of new tumor markers, precursor of prostate specific antigen (p2PSA) and its derivates-%p2PSA and prostate health index (PHI) in detection of patients with indolent and aggressive prostate cancer (PC) in a subcohort of man whose total PSA ranged from 2 to 10ng/mL. Materials and Methods This cross-sectional study included 129 consecutive male patients aged over 50 years, with no previous history of PC and with normal digital rectal examination findings, but with serum PSA in interval between 2 and 10ng/mL. All patients underwent standard transrectal ultrasonography guided prostate biopsy for the first time. For all patients, serum PSA, free PSA (fPSA) and p2PSA were measured and PHI and %p2PSA were calculated. Results PHI and %p2PSA levels were significanlty higher in patients with PC compared to those without this malignancy. The same findings have been observed in group of patients with Gleason score ≥7 compared to those with Gleason score <7. ROC analysis reveled the highest area under the curve with these two markers. Multivariate logistic regression showed significant improvement in PC detection and its agressive form (assumed as Gleason score ≥7). Conclusions New markers, derivates of p2PSA (especially %p2PSA and PHI), represente potentially very important clinical tool for predicting presence of PC, and even more important, to discriminate patients with Gleason score <7 from those with Gleason score ≥7 with total PSA in range from 2 to 10ng/mL. PMID:28124526

  6. Differential cross sections for the single ionization of H2 by 75 keV proton impact

    NASA Astrophysics Data System (ADS)

    Igarashi, A.; Gulyás, L.

    2017-02-01

    We have calculated the double and triple differential cross sections for electron ejection with energy of 14.6 eV in single ionization of H2 by 75 keV proton impact. A molecular version of the continuum distorted wave-eikonal initial state approach is applied, where the interaction between the projectile and the residual molecular ion is considered more properly than in previous applications of the method. For triple differential cross sections, the present results are in better agreement with the experimental data than those of other descriptions when large momentum transfer values are considered. For double differential cross sections the experimental data are reproduced quite well for both coherent and incoherent proton beams.

  7. Nighttime observations of 0.2- to 26-keV electrons in the South Atlantic anomaly made by Atmosphere Explorer C

    NASA Technical Reports Server (NTRS)

    Gledhill, J. A.; Hoffman, R. A.

    1981-01-01

    Atmosphere Explorer C satellite observations have determined that the flux of low energy ions in the South Atlantic Anomaly is much smaller than that of electrons, allowing the satellite's low-energy ion detector to monitor the high-energy background and correct the low-energy electron detector accordingly. It is shown that the electron spectra can be represented by a power law in the range 0.2-26.0 keV, with the spectral index close to -1.0, and that the mean energy flux carried by electrons in the middle of the anomaly is about 0.003 erg/sq cm/sec and may reach 5 times this value. Maps of the downward energy flux are included.

  8. Studies on effective atomic numbers and electron densities in amino acids and sugars in the energy range 30 1333 keV

    NASA Astrophysics Data System (ADS)

    Gowda, Shivalinge; Krishnaveni, S.; Gowda, Ramakrishna

    2005-10-01

    The effective atomic numbers and electron densities of the amino acids glycine, alanine, serine, valine, threonine, leucine, isoleucine, aspartic acid, lysine, glutamic acid, histidine, phenylalanine, arginine, tyrosine, tryptophane and the sugars arabinose, ribose, glucose, galactose, mannose, fructose, rhamnose, maltose, melibiose, melezitose and raffinose at the energies 30.8, 35.0, 81.0, 145, 276.4, 302.9, 356, 383.9, 661.6, 1173 and 1332.5 keV were calculated by using the measured total attenuation cross-sections. The interpolations of total attenuation cross-sections for photons of energy E in elements of atomic number Z was performed using the logarithmic regression analysis of the XCOM data in the photon energy region 30-1500 keV. The best-fit coefficients obtained by a piece wise interpolation method were used to find the effective atomic number and electron density of the compounds. These values are found to be in good agreement with the theoretical values calculated based on XCOM data.

  9. Calculations of photo-induced X-ray production cross-sections in the energy range 1-150 keV and average fluorescence yields for Zn, Cd and Hg

    NASA Astrophysics Data System (ADS)

    Sampaio, J. M.; Guerra, M.; Parente, F.; Madeira, T. I.; Indelicato, P.; Santos, J. P.; Marques, J. P.

    2016-09-01

    In this paper, we calculate the K-, L- and M-shells X-ray production, and X-ray fluorescence cross-sections after photo-induced ionization, for Zn, Cd, and Hg, and for incident photon energy range from 1 to 150 keV. For this purpose, the corresponding average fluorescence yields for Zn, Cd, and Hg as well as the photoionization cross-sections were calculated using the Dirac-Fock method. Subshell fluorescence, intrashell and intershell yields are obtained consistently from radiative and radiationless transitions calculated in the exact same method. A comprehensive account of the relations between the X-ray production, X-ray fluorescence cross-sections and the photoionization cross-sections and these yields is presented. Comparisons are made with results from other authors. The obtained values for the photoionization cross-sections are in good agreement with the widely used data of Scofield in the studied energy range. However our results for the X-ray fluorescence cross sections seem to favor some data relatively to others. The energy dependence of the average fluorescence yields is discussed, in particular, the reliability of extrapolated data for lighter elements from measurements and calculations in heavier elements above the inner shell absorption edges is questioned. Tabulated data on photoionization and X-ray production cross-sections are presented for the incident photon energy range 1-150 keV in steps of 1 keV.

  10. 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.

  11. The 3-10 keV and 0.1- to 2-MeV observations of 4 gamma-ray bursts

    NASA Astrophysics Data System (ADS)

    Laros, J. G.; Evans, W. D.; Fenimore, E. E.; Klebesadel, R. W.; Shulman, S.; Fritz, G.

    Four catalogued (BETA) ray bursts that occurred between 79/3/7 and 79/7/31 were observed over the 3 to 10 keV range. The bursts were also well observed by members of the interplanetary network. Hardness ratios, X-ray/(BETA)-ray luminosity ratios, and are presented. The results are summarized as follows: (1) gamma ray bursters can emit fairly strongly at X-ray energies near the time of the (BETA) burst with L/sub x//L/sub (BETA)/approx. .02 (L/sub x/ approx. 10(37) ergs s(+1), 3 to 10 keV, assuming a distance of 1 kpc); (2) the centroid of the X-ray emission generally lags the (BETA)-ray centroid, but there is also evidence for one or more types of X-ray precursor activity; (3) the (BETA)-ray hardness ratios were not highly variable for these particular events; (4) the X-ray/(BETA)-ray power law number index during times of the strongest (BETA)-ray emission ranged from 0.8 to approx. 1.1 for the four bursts; (5) the X-ray tail of GB790307 probably can be modeled as the cooling of hot plasma generated during the (BETA)-ray burst. Simple versions of this model can be used to estimate various source parameters. These estimates imply a distance of a few hundred to a few thousand pc; (6) gamma-ray bursters probably do not produce events similar to classical X-ray bursts independently of the (BETA)-ray emission.

  12. Image information transfer properties of x-ray intensifying screens in the energy range from 17 to 320 keV.

    PubMed

    Ginzburg, A; Dick, C E

    1993-01-01

    The image information transfer properties of a number of x-ray fluorescent screens have been measured for x-ray energies from 17 to 320 keV. The detective quantum efficiency of the screens at each x-ray energy has been determined by separate measurements of the x-ray absorption efficiency and the statistical factor associated with the emission of optical photons upon absorption of an incident x-ray. Data have been recorded for both rare-earth phosphor screens and calcium tungstate screens. The value of the statistical factor for optical photon emission tends toward a constant value as the incident energy increases. Comparisons of the image information transfer properties are presented for several screens, which have been measured over a ten year interval. The utility of the screens for high-energy radiography is discussed.

  13. 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.

  14. 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…

  15. Variation in the calibrated response of LiF, Al2O3, and silicon dosimeters when used for in-phantom measurements of source photons with energies between 30 KeV AND 300 KeV.

    PubMed

    Poudel, Sashi; Currier, Blake; Medich, David C

    2015-04-01

    The MCNP5 radiation transport code was used to quantify changes in the absorbed dose conversion factor for LiF, Al2O3, and silicon-based electronic dosimeters calibrated in-air using standard techniques and summarily used to measure absorbed dose to water when placed in a water phantom. A mono-energetic photon source was modeled at energies between 30 keV and 300 keV for a point-source placed at the center of a water phantom, a point-source placed at the surface of the phantom, and for a 10-cm radial field geometry. Dosimetric calculations were obtained for water, LiF, Al2O3, and silicon at depths of 0.2 cm and 10 cm from the source. These results were achieved using the MCNP5 *FMESH photon energy-fluence tally, which was coupled with the appropriate DE/DF card for each dosimetric material studied to convert energy-fluence into the absorbed dose. The dosimeter's absorbed dose conversion factor was calculated as a ratio of the absorbed dose to water to that of the dosimeter measured at a specified phantom depth. The dosimeter's calibration value also was obtained. Based on these results, the absorbed dose conversion factor for a LiF dosimeter was found to deviate from its calibration value by up to 9%, an Al2O3 dosimeter by 43%, and a silicon dosimeter by 61%. These data therefore can be used to obtain LiF, Al2O3, and silicon dosimeter correction factors for mono-energetic and poly-energetic sources at measurement depths up to 10 cm under the irradiation geometries investigated herein.

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

    SciTech Connect

    Kyrala, George A.

    2006-05-15

    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 2-4 keV range and the iron spectrum in the 5-8.5 keV 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.

  18. 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.

  19. A new international geostationary electron model: IGE-2006, from 1 keV to 5.2 MeV

    NASA Astrophysics Data System (ADS)

    Sicard-Piet, A.; Bourdarie, S.; Boscher, D.; Friedel, R. H. W.; Thomsen, M.; Goka, T.; Matsumoto, H.; Koshiishi, H.

    2008-07-01

    Département Environnement Spatial, Office National d'Etudes et de Recherches Aérospatiales (ONERA) has been developing a model for the geostationary electron environment since 2003. Until now, this model was called Particle ONERA-LANL Environment (POLE), and it is valid from 30 keV up to 5.2 MeV. POLE is based on the full complement of Los Alamos National Laboratory geostationary satellites, covers the period 1976-2005, and takes into account the solar cycle variation. Over the period 1976 to present, four different detectors were flown: charged particle analyzer (CPA), synchronous orbit particle analyzer (SOPA), energetic spectra for particles (ESP), and magnetospheric plasma analyzer (MPA). Only the first three were used to develop the POLE model. Here we extend the energy coverage of the model to low energies using MPA measurements. We further include the data from the Japanese geostationary spacecraft, Data Relay Test Satellite (DRTS). These data are now combined into an extended geostationary electron model which we call IGE-2006.

  20. Spectroscopy of {sup 20}Mg: The isobaric mass multiplet equation for the 2{sup +} states of the A=20, T=2 quintet and distant mirror nuclei

    SciTech Connect

    Gade, A.; Bowen, M. D.; Brown, B. A.; Campbell, C. M.; Cook, J. M.; Glasmacher, T.; McDaniel, S.; Siwek, K.; Adrich, P.; Bazin, D.; Obertelli, A.; Weisshaar, D.; Hosier, K.; McGlinchery, D.; Riley, L. A.

    2007-08-15

    We report on the first determination of the 2{sub 1}{sup +} energy of {sup 20}Mg, the most neutron-deficient Mg isotope known to exist. The result, E(2{sub 1}{sup +})=1598(10) keV, obtained from in-beam {gamma}-ray spectroscopy following the two-neutron removal from a {sup 22}Mg secondary beam, is discussed in the framework of the isobaric mass multiplet equation (IMME). Resulting predictions for the excitation energies of the T=2,2{sup +} states in the {sup 20}F and {sup 20}Na isobars are presented. The mirror energy difference, E(2{sub 1}{sup +},{sup 20}Mg)-E(2{sub 1}{sup +},{sup 20}O)=-77(10) keV, is compared to a recent prediction within the nuclear shell model based on the 'USD'm - gap Z14<'' modification of the universal sd (USD) effective interaction.

  1. a New Method for the Growth of CdTe Crystals for RT X-Ray Photon Detectors in the 1-100 keV Range

    NASA Astrophysics Data System (ADS)

    Lovergine, N.; Mancini, A. M.; Cola, A.; Prete, P.; Mazzer, M.; Quaranta, F.; Tapfer, L.

    2000-12-01

    We report on the growth of thick CdTe layers on ZnTe/(100)GaAs hybrid substrates by the novel H2 transport vapour phase epitaxy (H2T-VPE) method. High crystalline quality (100)-oriented CdTe single crystal epilayers can be fabricated under atmospheric pressure and at growth temperatures (TD) in the 600-800°C interval. Double crystal X-ray diffraction measurements performed on epilayers thicker than 30 μm show CdTe (400) peaks with FWHM<59 arcsec. CdTe samples grown under optimised conditions have mirror-like surfaces. Epilayers grown below 650°C are p-type and low resistive, but they turn n-type above 650°C, likely as a result of donor diffusion from the substrate. RT resistivities (ρ) ~ 106 Ω·cm are obtained for 675°C < TD < 700°C, but ρ decreases for higher temperatures and thinner samples. Layers grown under these conditions show RT electron concentrations in the 1014-1011 cm-3 range. The detection capability of H2T-VPE grown CdTe is demonstrated by the results of time-of-flight measurements performed at RT on Au/n-CdTe/n+-GaAs diode structures under reverse bias conditions.

  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. Determination of natural line widths of Kα X-ray lines for some elements in the atomic range 50≤Z≤65 at 59.5 keV

    NASA Astrophysics Data System (ADS)

    Kündeyi, Kadriye; Aylıkcı, Nuray Küp; Tıraşoǧlu, Engin; Kahoul, Abdelhalim; Aylıkcı, Volkan

    2017-02-01

    The semi-empirical determination of natural widths of Kα X-ray lines (Kα1 and Kα2) were performed for Sn, Sb, Te, I, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd and Tb. For the semi-empirical determination of the line widths, K shell fluorescence yields of elements were measured. The samples were excited by 59.5 keV γ rays from a 241Am annular radioactive source in order to measure the K shell fluorescence yields. The emitted K X-rays from the samples were counted by an Ultra-LEGe detector with a resolution of 150 eV at 5.9 keV. The measured K shell fluorescence yields were used for the calculation of K shell level widths. Finally, the natural widths of K X-ray lines were determined as the sums of levels which involved in the transition. The obtained values were compared with earlier studies.

  4. Comparative Effects of 10.2 eV Photon and 200 keV Proton Irradiation on Condensed CO

    NASA Astrophysics Data System (ADS)

    Loeffler, M. J.; Baratta, G. A.; Palumbo, M. E.; Strazzulla, G.; Baragiola, R. A.

    2004-03-01

    We present results from experiments that use infrared spectroscopy to compare production rates of carbon dioxide formed by UV photolysis and 200 keV proton irradiation of carbon monoxide ice at 16 K. We find production rates to be similar for both types of irradiation.

  5. 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.

  6. An Examination of Directional Discontinuities and Magnetic Polarity Changes around Interplanetary Sector Boundaries Using E > 2 keV Electrons

    NASA Astrophysics Data System (ADS)

    Kahler, S. W.; Lin, R. P.

    1995-10-01

    Past studies of interplanetary magnetic sector boundaries have been based on the assumption that one can determine the field polarities by comparing the field directions with those of the nominal Parker spiral angles. Previous investigators have found evidence for decreases of ∣B∣, the magnitude of the magnetic fieldB, and increases of Θ, the angle betweenB and the ecliptic plane, at sector boundaries. Others have argued that the characteristic thickness of sector boundaries exceeds that of tangential discontinuities, making sector boundaries a separate class of structures. We use a simple technique for inferring the polarities of interplanetary magnetic fields based on the assumption thatE > 2 keV electrons are always flowing along the magnetic field away from the Sun. Electron data from the UC Berkeley experiment on the ISEE-3 spacecraft are used to examine periods around several apparent sector boundaries in 1978 and 1979. We compare properties of (a) boundaries with field polarity changes and (b) large-angle (ω > 60°) directional discontinuities with no field polarity changes. We find no significant differences between the sector boundaries and the directional discontinuities in terms of associated decreases in ∣B∣ or of values of Θ. These results suggest no significant difference between sector boundaries and directional discontinuities other than the change in field polarities. Within limited statistics we find that about half the polarity changes would not have been identified using a requirement thatω > 90° and that half of theω > 120° discontinuities would have been misidentified as polarity changes.

  7. 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.

  8. 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

  9. Ion survival probabilities for 3 keV Ar + scattering from La, Yb, and chemisorbed H 2, O 2, and H 2O on La surfaces

    NASA Astrophysics Data System (ADS)

    Kumar, Ranjit; Mintz, Moshe H.; Rabalais, J. Wayne

    1984-11-01

    TOF spectra of scattered primary and surface recoiled neutrals and ions for 3 keV Ar + bombardment of clean La and Yb and H 2, O 2, and H 2O saturated La surfaces are presented. The spectra are analyzed in terms of single (SS) and multiple (MS) scattering of the primary ions and surface recoiling (SR) of adsorbate atoms. Measurement of spectra of neutrals + ions and neutrals alone allows determination of scattered ion fractions Y. The Y values for the SS event are high for clean La (37%) and lower for adsorbate covered La (32% for H 2, 13% for O 2, and 8% for H 2O); Yb exhibits a similar behavior, i.e. 16% for clean Yb and 5% for O 2 + H 2O covered Yb. Photon emission accompanying the scattering collision has been observed from clean La and Yb and adsorbate covered La. A preferential inelastic energy loss of 15 ± 3 eV for the SS event has been observed for scattered neutrals as opposed to ions for La and H 2 saturated La at 135°. These results are interpreted within the models for Auger and resonant electronic charge exchange transitions during approach or departure of an ion with a surface and the electron promotions occuring during close atomic encounters where the electron shells are interpenetrating.

  10. 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

  11. FDEM v. 2.0

    SciTech Connect

    Aldridge, David F.; Schramm, Kimberly A.

    2016-08-08

    Program FDEM_v2.0 is designed to simulate three-dimensional (3D) electromagnetic (EM) wave propagation within an isotropic and heterogeneous body. The medium is characterized by the three isotropic (but spatially-variable) parameters electric permittivity, magnetic permeability, and current conductivity. The numerical solution methodology is explicit, time-domain, finite-differencing of the EH (i.e., electric vector – magnetic vector) coupled partial differential system on uniform, but staggered, spatial and temporal grids. FDEM_v2.0 incorporates “perfectly matched layer” (PML) absorbing boundary conditions on all flanks of the 3D spatial grid that effectively suppress grid boundary reflections.

  12. A Multi-Center Study of [−2]Pro-Prostate-Specific Antigen (PSA) in Combination with PSA and Free PSA for Prostate Cancer Detection in the 2.0 to 10.0 ng/mL PSA Range

    PubMed Central

    Catalona, William J.; Partin, Alan W.; Sanda, Martin G.; Wei, John T.; Klee, George G.; Bangma, Chris H.; Slawin, Kevin M.; Marks, Leonard S.; Loeb, Stacy; Broyles, Dennis L.; Shin, Sanghyuk S.; Cruz, Amabelle B.; Chan, Daniel W.; Sokoll, Lori J.; Roberts, William L.; van Schaik, Ron H.N.; Mizrahi, Isaac A.

    2011-01-01

    Purpose PSA and free PSA (fPSA) have limited specificity for detecting clinically significant, curable prostate cancer (PCa), leading to unnecessary biopsies and detection and treatment of some indolent tumors. [−2]proPSA (p2PSA) may improve specificity for detecting clinically significant PCa. Our objective was to evaluate p2PSA, fPSA, and PSA in a mathematical formula (prostate health index [phi] = [−2]proPSA / fPSA) × PSA1/2) to enhance specificity for detecting overall and high-grade PCa. Materials and Methods We enrolled 892 men in a prospective multi-institutional trial with no history of PCa, normal rectal examination, a PSA of 2–10 ng/mL, and ≥6- core prostate biopsy. We examined the relationship of serum PSA, %fPSA and phi with biopsy results. The primary endpoints were the specificity and AUC using phi to detect overall and Gleason ≥7 prostate cancer on biopsy compared with %fPSA. Results For the 2–10 ng/mL PSA range, at 80–95% sensitivity, the specificity and AUC (0.703) of phi exceeded those of PSA and %fPSA. Increasing phi was associated with a 4.7-fold increased risk of PCa and 1.61-fold increased risk of Gleason ≥7 disease on biopsy. The AUC for phi (0.724) exceeded that of %fPSA (0.670) in discriminating between PCa with Gleason ≥ 4+3 vs. lower grade disease or negative biopsies. Phi results were not associated with age and prostate volume. Conclusions Phi may be useful in PCa screening to reduce unnecessary biopsies in men age ≥50 years with PSA 2–10 ng/mL and negative DRE, with minimal loss in sensitivity. PMID:21419439

  13. 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…

  14. 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

  15. 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.

  16. Absolute calibration of the Agfa Structurix series films at energies between 2.7 and 6.2 keV.

    PubMed

    Lanier, N E; Cowan, J S

    2014-11-01

    Although photo-emulsion technology is many decades old, x-ray film still remains a key asset for diagnosing hydrodynamic features in High-Energy Density (HED) experiments. For decades, the preferred option had been Kodak's direct exposure film. After its discontinuance in 2004, the push to find alternatives began. In many situations, the Agfa Structurix series offers the most favorable substitute, but being new to the HED community, its characterization was lacking. To remedy this, recent experiments, conducted at Brookhaven's National Synchrotron Light Source, provide absolute, monochromatic calibration data for the Agfa Structurix series films at K-shell backlighter energies between 2.7 and 6.2 keV. Absolute response curves are presented for Agfa D8, D7, D4, D4sc, D3, and D2. Moreover, the transmission of each film type is also measured.

  17. 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.

  18. Stopping power for electrons in pyrimidine in the energy range 20-3000 eV.

    PubMed

    Colmenares, R; Sanz, A G; Fuss, M C; Blanco, F; García, G

    2014-01-01

    In this work, we present new experimental electron energy loss distribution functions for pyrimidine (C4H4N2) measured for the incident energy range 30-2000 eV. Theoretical total and elastic cross sections for electron scattering from pyrimidine were calculated using the screening-corrected additivity rule (IAM-SCAR) method. Based on the mean energy loss observed in the experiment and the theoretical integral inelastic cross section, the stopping power for electrons in pyrimidine is calculated in the energy range 20-3000 eV.

  19. Neutron fluence and energy reconstruction with the IRSN recoil detector μ-TPC at 27 keV, 144 keV and 565 keV

    SciTech Connect

    Maire, D.; Lebreton, L.; Richer, J.P.; Bosson, G.; Bourrion, O.; Guillaudin, O.; Riffard, Q.; Santos, D.

    2015-07-01

    The French Institute for Radioprotection and Nuclear Safety (IRSN), associated to the French Metrology Institute (LNE), is developing a time projection chamber using a Micromegas anode: μ-TPC. This work is carried out in collaboration with the Laboratory of Subatomic Physics and Cosmology (LPSC). The aim is to characterize with a primary procedure the energy distribution of neutron fluence in the energy range 8 keV - 1 MeV. The time projection chambers are gaseous detectors, which are able to measure charged particles energy and to reconstruct their track if a pixelated anode is used. In our case, the gas is used as a (n, p) converter in order to detect neutrons down to few keV. Coming from elastic collisions with neutrons, recoil protons lose a part of their kinetic energy by ionizing the gas. The ionization electrons are drifted toward a pixelated anode (2D projection), read at 50 MHz by a self-triggered electronic system to obtain the third track dimension. The neutron energy is reconstructed event by event thanks to proton scattering angle and proton energy measurements. The scattering angle is deduced from the 3D track. The proton energy is obtained by charge collection measurements, knowing the ionization quenching factor (i.e. the part of proton kinetic energy lost by ionizing the gas). The fluence is calculated thanks to the detected events number and the simulated detector response. The μ-TPC is a new reliable detector which enables to measure energy distribution of the neutron fluence without deconvolution or neutron calibration contrary to usual gaseous counters. The μ-TPC is still being developed and measurements have been carried out at the AMANDE facility, with neutrons energies going from 8 keV to 565 keV. After the context and the μ-TPC working principle presentation, measurements of the neutron energy and fluence at 27.2 keV, 144 keV and 565 keV are shown and compared to the complete detector simulation. This work shows the first direct

  20. 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)

  1. Relative dissociation fractions of N2O under 15 -30 -keV H-,C- , and O- negative-ion impact

    NASA Astrophysics Data System (ADS)

    Wang, Dedong; Guo, Guannan; Min, Guangxin; Zhang, Xuemei

    2017-01-01

    The relative dissociation fractions of N2O are studied under 15-30-keV negative ions H-,C- , and O- impact. The recoil ions and ion pairs originating from the target molecule N2O are detected and identified in coincidence with scattered ions in single electron loss (SL) and double electron loss (DL) channels using a time-of-flight mass spectrometer. The dissociation fractions for the production of the fragment ions are obtained. We find that the relative dissociation fractions in SL are smaller than those in DL, and the degree of fragmentation will become greater with the impact energy increasing. We also analyze the coincident TOF spectra of two fragment ions which are produced from dissociation of N2O2 + and give the possible dissociation pathways of N2O2 + with 15 -30 -keV H-,C- , and O- impact. There are many studies on N2O with positive-ion, photon, and electron impact, and we compare our results under negative-ion impact with those works.

  2. 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

  3. Biocellion Version 2.0

    SciTech Connect

    Seunghwa Kang, PNNL

    2015-01-09

    This work extends Biocellion 1.0 to solve advection-reaction-diffusion and incompressible Navier-Stokes partial differential equations to model water/blood flow. Biocellion is a software framework to simulate a large number of cells using high-performance parallel computers. The version 1.0 allows software users to describe biological system behaviors as a set of rules describing how individual cells behave and how cells locally interact with neighboring cells or the surrounding micro-environment. However, the version 1.0 does not support users to incorporate water/blood flow into the model, which is important to properly capture long distance communications between distant cells. This extension (version 2.0) integrates two partial differential equation solvers to the Biocellion framework to solve this limitation. Navier-Stokes equation solvers (for incompressible flow) are added to compute flow rate, and advection-reaction-diffusion equation solvers are added to update molecular concentrations considering both advection (due to flow) and local diffusion.

  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. Performance of a Supersonic Ramp-type Side Inlet with Ram-scoop Throat Bleed and Varying Fuselage Boundary-layer Removal : Mach Number Range 1.5 to 2.0 / Glenn A. Mitchell and Robert C. Campbell

    NASA Technical Reports Server (NTRS)

    Mitchell, Glenn A; Campbell, Robert C

    1957-01-01

    Provided sufficient throat bleed was employed, maximum pressure recoveries of 0.87 to 0.88 at Mach number 2.0 were obtained for a fuselage-mounted 14 degrees ramp inlet regardless of the amount of fuselage boundary layer ingested. The addition of inlet side fairings yielded further increases in pressure recovery to 0.90 to 0.91, decreased critical drag coefficients, and increased critical mass-flow ratios. With throat bleed, peak pressure recoveries and calculated thrust-minus-drag values were comparable at two axial positions of the scoop and were highest with the greatest amount of fuselage boundary layer ingested.

  7. Charge transfer in collisions of B{sup 2+}({sup 2}{ital S},{sup 2}{ital P}) and B{sup 3+}({sup 1}{ital S}) ions with He atoms below 200 keV

    SciTech Connect

    Kimura, M. |; Suzuki, S.; Shimakura, N.; Gu, J.P.; Hirsch, G.; Buenker, R.J.; Shimamura, I.

    1996-10-01

    Charge transfer in B{sup 2+}({sup 2}{ital S},{sup 2}{ital P})+He and in B{sup 3+}({sup 1}{ital S})+He collisions is studied theoretically by using a semiclassical molecular representation with 8 and 12 molecular channels for B{sup 2+} and B{sup 3+} on He systems, respectively, at collision energies between 200 eV and 200 keV for the former and between 600 eV and 50 keV for the latter. The {ital ab} {ital initio} potential curves and nonadiabatic coupling matrix elements are obtained from the multireference single- and double-excitation configuration-interaction (MRD-CI) calculations for the B{sup 2+}-He system and a pseudopotential-modified configuration-interaction method for the B{sup 3+}-He system. The present cross sections for charge transfer by the ground state B{sup 2+} ions are found to have a broad maximum with a magnitude as large as 2{times}10{sup {minus}15} cm{sup 2} at 100 keV and those by an excited B{sup 2+}({sup 2}{ital P}) state are found to be larger by a factor of 6 than those by the ground state in the same energy regime. B{sup 2+}-excitation cross sections are smaller than those for charge transfer below 1 keV, while they increasingly dominate above this energy. The present total charge-transfer cross section for B{sup 3+} in collisions with He is similar to that obtained in earlier work by Gargaud {ital et} {ital al}. [J. Phys. B {bold 27}, 3985 (1994)] both in magnitude and energy dependence, but is found to show slightly different B{sup 2+}(2{ital s}) and B{sup 2+}(2{ital p}) production ratio. {copyright} {ital 1996 The American Physical Society.}

  8. 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

  9. 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%.

  10. 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.

  11. Elastic and inelastic processes in H{sup +}+CH{sub 2} collisions between 0.5 and 1.5 keV

    SciTech Connect

    Suno, Hiroya; Rai, Sachchida N.; Liebermann, Heinz-Peter; Buenker, Robert J.; Kimura, Mineo; Janev, R.K.

    2004-09-01

    Electron capture and direct elastic scattering in collisions of H{sup +} ions with CH{sub 2} molecules between 0.5 and 1.5 keV are theoretically investigated. A molecular representation is adopted within a fully quantum-mechanical approach. We consider the following four different molecular configurations for collision dynamics: (I) the proton approaches the C atom along the bisector of the H--C--H bond angle, passing the midpoint of the H-H line (II) it comes along the same line as in (I), but in the opposite direction (III) the proton approaches the C atom in the H-C-H plane and perpendicularly to the bisector of the H-C-H bond angle, and (IV) the proton approaches the C atom perpendicularly to the H-C-H plane. Differential cross sections for elastic scattering and electron capture are calculated at 1.5 and 0.5 keV for these different molecular orientations. Total cross sections for these four orientations as well as orientation-averaged total cross sections are also calculated. Our results indicate that electron capture dynamics and corresponding electron-capture cross sections depend substantially on the molecular configuration, thus revealing a strong steric effect.

  12. Elastic and inelastic processes in H{sup +}+NH{sub 2} collisions between 0.5 and 1.5 keV

    SciTech Connect

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

    2006-07-15

    Electron capture and direct elastic scattering in collisions of H{sup +} ions with NH{sub 2} molecules between 0.5 and 1.5 keV are theoretically investigated. A molecular representation is adopted within a fully quantum-mechanical approach. We consider the following four different molecular configurations for collision dynamics: (I) the proton approaches the N atom along the bisector of the H-N-H bond angle, passing the midpoint of the H-H line (II) it comes along the same line as in (I), but in the opposite direction (III) the proton approaches the N atom in the H-N-H plane and perpendicularly to the bisector of the H-N-H bond angle, and (IV) the proton approaches the N atom perpendicularly to the H-N-H plane. Differential cross sections for elastic scattering and electron capture are calculated at 1.5 and 0.5 keV for these different molecular orientations. Total cross sections for these four orientations as well as orientation-averaged total cross sections are also calculated. Our results indicate that electron-capture dynamics and corresponding electron-capture cross sections depend substantially on the molecular configuration, thus revealing a strong steric effect.

  13. Energy-discrimination X-ray computed tomography system utilizing a silicon-PIN detector and its application to 2.0-keV-width K-edge imaging

    NASA Astrophysics Data System (ADS)

    Hagiwara, Osahiko; Watanabe, Manabu; Sato, Eiichi; Matsukiyo, Hiroshi; Osawa, Akihiro; Enomoto, Toshiyuki; Nagao, Jiro; Sato, Shigehiro; Ogawa, Akira; Onagawa, Jun

    2011-05-01

    Demonstration of narrow-energy-width computed tomography (CT) was carried out by means of energy-discrimination. An X-ray CT system is of a first-generation type and consists of an X-ray generator, a turntable, a translation stage, a two-stage controller, a silicon-PIN detector system with amplifiers, a multi-channel analyzer (MCA), a counter card (CC), and a personal computer (PC). CT is accomplished by repeating the translation and the rotation of an object, and projection curves of the object are obtained by the translation of the moving object. Both photon-energy level and energy width are determined by the MCA, and the pulses of the discriminated event signal from the MCA are counted by CC in conjunction with PC. The maximum count rate was approximately 300 cps (counts per second) with energy widths of 2.0 keV, and energy-discrimination CT was carried out with a photon-energy resolution of 0.15 keV. To perform iodine K-edge CT, X-ray photons with an energy range from 33.2 to 35.2 keV were used. Next, to carry out cerium K-edge CT, an energy range from 40.3 to 42.3 keV was selected.

  14. Colliding the hydrocarbon building blocks of astrochemical polycyclic aromatic hydrocarbons with 8 keV He+* and H2+* ions: Luminescence from methane, acetylene, benzene and naphthalene

    NASA Astrophysics Data System (ADS)

    Rashid, Shaan; Sit, Alicia; West, Brandi; Mayer, Paul M.

    2017-01-01

    Emission spectra from collisions of 8 keV He+ and H2+rad with neutral naphthalene, benzene, acetylene and methane were acquired over 190-1020 nm on a modified double-focusing mass spectrometer. The bands, emission intensities and the minimum excitation energy to produce the observed transitions (Emin) were compared for the two projectile ions. Emin values were the same for both projectiles but the emission intensity is greater in the case of He+ . This is consistent with calculations at the CISD/6-311+G(2df) level on the excited states of the respective collision complexes which exhibited two distinct state-crossing points for He+ collisions but none for H2+rad collisions.

  15. A Compton camera for spectroscopic imaging from 100keV to 1MeV

    NASA Astrophysics Data System (ADS)

    Earnhart, Jonathan Raby Dewitt

    The objective of this work is to investigate Compton camera technology for spectroscopic imaging of gamma rays in the 100keV to 1MeV range. An efficient, specific purpose Monte Carlo code was developed to investigate the image formation process in Compton cameras. The code is based on a pathway sampling technique with extensive use of variance reduction techniques. The code includes detailed Compton scattering physics, including incoherent scattering functions, Doppler broadening, and multiple scattering. Experiments were performed with two different camera configurations for a scene containing a 75Se source and a 137Cs source. The first camera was based on a fixed silicon detector in the front plane and a CdZnTe detector mounted in the stage. The second camera configuration was based on two CdZnTe detectors. Both systems were able to reconstruct images of 75Se, using the 265keV line, and 137Cs, using the 662keV line. Only the silicon-CdZnTe camera was able to resolve the low intensity 400keV line of 75Se. Neither camera was able to reconstruct the 75Se source location using the 136keV line. The energy resolution of the silicon-CdZnTe camera system was 4% at 662keV. This camera reproduced the location of the 137Cs source by event circle image reconstruction with angular resolutions of 10° for a source on the camera axis and 14° for a source 30° off axis. Typical detector pair efficiencies were measured as 3 x 10-11 at 662keV. The dual CdZnTe camera had an energy resolution of 3.2% at 662keV. This camera reproduced the location of the 137Cs source by event circle image reconstruction with angular resolutions of 8° for a source on the camera axis and 12° for a source 20° off axis. Typical detector pair efficiencies were measured as 7 x 10-11 at 662keV. Of the two prototype camera configurations tested, the silicon-CdZnTe configuration had superior imaging characteristics. This configuration is less sensitive to effects caused by source decay cascades and random

  16. Storing keV Negative Ions for an Hour: The Lifetime of the Metastable P21/2 o level in S32-

    NASA Astrophysics Data System (ADS)

    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.

    2015-04-01

    We use a novel electrostatic ion storage ring to measure the radiative lifetime of the upper level in the 3 p5 P21/2 o→3 p5 P23/2 o spontaneous radiative decay in S- 32 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 1.3 σ from the only available theoretical prediction [P. Andersson et al., Phys. Rev. A 73, 032705 (2006)].

  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, 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...

  19. 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...

  20. 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...

  1. 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...

  2. 29 CFR 20.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Definitions. 20.2 Section 20.2 Labor Office of the Secretary of Labor FEDERAL CLAIMS COLLECTION Disclosure of Information to Credit Reporting Agencies § 20.2... excess of $100, arising from loans, loan guarantees, overpayments, fines, penalties or other causes....

  3. 27 CFR 20.2 - Territorial extent.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Territorial extent. 20.2 Section 20.2 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS DISTRIBUTION AND USE OF DENATURED ALCOHOL AND RUM Scope § 20.2...

  4. 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…

  5. 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...

  6. 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,…

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

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

    PubMed

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

    2015-02-01

    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.

  13. Measurement of the x-ray mass energy-absorption coefficient of air using 3 keV to 10 keV synchrotron radiation.

    PubMed

    Büermann, L; Grosswendt, B; Kramer, H-M; Selbach, H-J; Gerlach, M; Hoffmann, M; Krumrey, M

    2006-10-21

    For the first time absolute photon mass energy-absorption coefficients of air in the energy range 3 keV to 10 keV have been measured with relative standard uncertainties less than 1%, significantly smaller than those of up to 5% assumed hitherto for calculated data. Monochromatized synchrotron radiation was used to measure both the total radiant energy by means of silicon photodiodes calibrated against a cryogenic radiometer and the fraction of radiant energy that is deposited in dry air by means of a free air ionization chamber. The measured ionization charge was converted into energy absorbed in air by calculated effective W values of photons as a function of their energy based on new measurements of the W values in dry air for electron kinetic energies between 1 keV and 7 keV, also presented in this work. The measured absorption coefficients were compared with state-of-the art calculations and found to agree within 0.7% with data calculated earlier by Hubbell at energies above 4 keV but were found to differ by values up to 2.1% at 10 keV from more recent calculations of Seltzer.

  14. 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

  15. Robotic Range Clearance Competition (R2C2)

    DTIC Science & Technology

    2011-10-01

    was only done for the “subsurface real ” test range. After mapping the surface contour, the Rover was used to mark the locations of notable...8 Figure 6. Map of Wyoming Showing General Location of R2C2 Ranges...Figure 48. Team Sky Research Geophysical Coverage Map ........................................................49 Figure 49. Anomaly Location Accuracy

  16. Investigation of complete and incomplete fusion in 20Ne + 51V system using recoil range measurement

    NASA Astrophysics Data System (ADS)

    Ali, Sabir; Ahmad, Tauseeef; Kumar, Kamal; Rizvi, I. A.; Agarwal, Avinash; Ghugre, S. S.; Sinha, A. K.; Chaubey, A. K.

    2015-01-01

    Recoil range distributions of evaporation residues, populated in 20Ne + 51V reaction at Elab ≈ 145 MeV, have been studied to determine the degree of momentum transferred through the complete and incomplete fusion reactions. Evaporation residues (ERs) populated through the complete and incomplete fusion reactions have been identified on the basis of their recoil range in the Al catcher medium. Measured recoil range of evaporation residues have been compared with the theoretical value calculated using the code SRIM. Range integrated cross section of observed ERs have been compared with the value predicted by statistical model code PACE4.

  17. 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.

  18. A search for 2-photon emission from the 662 keV state in ^137Ba using Gammasphere

    NASA Astrophysics Data System (ADS)

    Lister, C. J.; McCutchan, E. A.; Moran, K.; Zhu, S.; Carpenter, M. P.; Greene, J. P.; Millener, J. D.; Sutter, R. J.; Alburger, D. E.

    2012-10-01

    Two photon decays from excited nuclear states provide an interesting test both of QED and nuclear structure. It has been extensively studied for cases where one photon decay is forbidden [1]. Two photon decay in direct competition with the first order process has never been convincingly demonstrated. Nonetheless, observation of this decay will provide additional challenging tests for experiment and theory. The ^137Ba case is particularly interesting as the decay has high multipolarity, M4, so the 2-photon process can have contributions from both quadrupole-quadrupole and dipole-octupole multipolarities. Gammasphere is the perfect tool for this investigation, having good energy resolution, good efficiency, good coverage of angles, and sufficient granularity to minimize pile-up and count-rate difficulties. A short test experiment showed the power of Gammasphere and the dauntingly high Compton scattering background that need suppression. However, new calculations and new measurements from Brookhaven suggest that the two photon branch is ˜2 x 10-6 and should be measurable. This work was supported by DOE contracts, DE-FG02-94ER40848, DE-AC02-06CH11357 and DE-AC02-98CH10946.[4pt] [1] J. Kramp, et. al, Nucl. Phys. A474 (1987) 412

  19. DIVA V2.0

    SciTech Connect

    CHEN, JOANNA; SIMIRENKO, LISA; TAPASWI, MANJIRI; PLAHAR, HECTOR

    2016-08-22

    and reaction conditions), completely independent DNA construction tasks can be aggregated into the same multi-well plates and pursued in parallel. The resulting sets of cloned constructs can then be screened by high-throughput next-gen sequencing platforms for sequence correctness. A combination of long read-length (e.g., PacBio) and paired-end read platforms (e.g., Illumina) would be exploited depending the particular task at hand (e.g., PacBio might be sufficient to screen a set of pooled constructs with significant gene divergence). Post sequence verification, designs for which at least one correct clone was identified will progress to a "complete" status, while designs for which no correct clones wereidentified will progress to a "failure" status. Depending on the failure mode (e.g., no transformants), and how many prior attempts/variations of assembly protocol have been already made for a given design, subsequent attempts may be made or the design can progress to a "permanent failure" state. All success and failure rate information will be captured during the process, including at which stage a given clonal construction procedure failed (e.g., no PCR product) and what the exact failure was (e.g. assembly piece 2 missing). This success/failure rate data can be leveraged to refine the DNA assembly design process.

  20. Effect of projectile coherence on multiple differential cross sections for 75 keV proton impact on H2

    NASA Astrophysics Data System (ADS)

    Sharma, S.; Egodapitiya, K.; Madison, D.; Schulz, M.; Hasan, A.; Laforge, A.; Moshammer, R.

    2011-10-01

    Recent results in ion-atom collision experiments suggest that discrepancies between theory and experiment are at least partly due to the representation of incoming projectile by a delocalized wave (coherent treatment). Recently we reported an experiment designed to investigate this. There, DDCS were measured for two different positions of the collimating slit. In one case the width of the proton wave packet was larger than the inter-nuclear separation of a H2 molecule (coherent case), while in the other it was much smaller than that (incoherent case). The two data sets were clearly different where in the coherent case a Young type interference structure was present and in the incoherent case it was not. Our next effort was to see the effects of projectile coherence on other processes such as single electron capture. Here we discuss the details of such an experiment and the observed results. Recent results in ion-atom collision experiments suggest that discrepancies between theory and experiment are at least partly due to the representation of incoming projectile by a delocalized wave (coherent treatment). Recently we reported an experiment designed to investigate this. There, DDCS were measured for two different positions of the collimating slit. In one case the width of the proton wave packet was larger than the inter-nuclear separation of a H2 molecule (coherent case), while in the other it was much smaller than that (incoherent case). The two data sets were clearly different where in the coherent case a Young type interference structure was present and in the incoherent case it was not. Our next effort was to see the effects of projectile coherence on other processes such as single electron capture. Here we discuss the details of such an experiment and the observed results. Funded by NSF.

  1. 2 CFR 175.20 - Referral.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Referral. 175.20 Section 175.20 Grants and Agreements OFFICE OF MANAGEMENT AND BUDGET GOVERNMENTWIDE GUIDANCE FOR GRANTS AND AGREEMENTS Reserved AWARD TERM FOR TRAFFICKING IN PERSONS § 175.20 Referral. An agency official should inform the...

  2. 2 CFR 175.20 - Referral.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 2 Grants and Agreements 1 2011-01-01 2011-01-01 false Referral. 175.20 Section 175.20 Grants and Agreements Office of Management and Budget Guidance for Grants and Agreements OFFICE OF MANAGEMENT AND BUDGET GOVERNMENTWIDE GUIDANCE FOR GRANTS AND AGREEMENTS AWARD TERM FOR TRAFFICKING IN PERSONS § 175.20 Referral....

  3. 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.

  4. Measurement of the instantaneous 200-MHz bunch currents at 750 keV for the CERN Linac 2

    SciTech Connect

    Knott, J.

    1983-08-01

    The efficiency of the longitudinal matching of the low energy proton beam with a double drift harmonic buncher (DDHB) depends on the correct setting of RF levels of the first and second harmonic buncher cavities and their respective phase. The adjustment is done by means of a retractable destructive broadband probe situated in front of the Linac input. It is essentially a piece of a well matched 50 ..cap omega.. line intercepting the beam perpendicular to its axis. At the beam side it is an asymmetric double strip line, forming a 1 mm gap between a highly transparent grid (90%) and a tantalum insert stopping the incoming beam on the inner conductor. One side of the line is open ended, the other smoothly tapered over a length of 30 mm into a coaxial line, continued outside the vacuum with a flexible low loss cable to observe the bunch signal on a 1.2 GHz real time oscilloscope. This signal should give the longitudinal proton density distribution and permits to optimize the bunching efficiency and to adjust the phase between the two buncher cavities to about 1/sup 0/ at 200 MHz. For high intensity beams the interpretation of the bunch shape requires some precaution as secondary and thermal electrons modify considerably the form of the expected signals.

  5. 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.

  6. Linear attenuation coefficients of tissues from 1 keV to 150 keV

    NASA Astrophysics Data System (ADS)

    Böke, Aysun

    2014-09-01

    The linear attenuation coefficients and three interaction processes have been computed for liver, kidney, muscle, fat and for a range of x-ray energies from 1 keV to 150 keV. Molecular photoelectric absorption cross sections were calculated from atomic cross section data. Total coherent (Rayleigh) and incoherent (Compton) scattering cross sections were obtained by numerical integration over combinations of F2m(x) with the Thomson formula and Sm(x) with the Klein-Nishina formula, respectively. For the coherent (Rayleigh) scattering cross section calculations, molecular form factors were obtained from recent experimental data in the literature for values of x<1 Å-1 and from the relativistic modified atomic form factors for values of x≥1 Å-1. With the inclusion of molecular interference effects in the coherent (Rayleigh) scattering, more accurate knowledge of the scatter from these tissues will be provided. The number of elements involved in tissue composition is 5 for liver, 47 for kidney, 44 for muscle and 3 for fat. The results are compared with previously published experimental and theoretical linear attenuation coefficients. In general, good agreement is obtained. The molecular form factors and scattering functions and cross sections are incorporated into a Monte Carlo program. The energy distributions of x-ray photons scattered from tissues have been simulated and the results are presented.

  7. A new grating X-ray spectrometer for 2-4 keV enabling a separate observation of In-Lβ and Sn-Lα emissions of indium tin oxide.

    PubMed

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

    2013-06-01

    A new multilayer-coated varied line-spaced grating, JS4000, was fabricated and tested for extending the upper limit of a grating X-ray spectrometer for electron microscopy. This grating was designed for 2-3.8 keV at a grazing incidence angle of 1.35°. It was revealed that this new multilayer structure enables us to take soft-X-ray emission spectra continuously from 1.5 to 4.3 keV at the same optical setting. The full-width at half maximum of Te-L(α1,2) (3.8 keV) emission peak was 27 eV. This spectrometer was applied to indium tin oxide particles and clearly resolved Sn-L(α) (3444 eV) and In-L(β1) (3487 eV) peaks, which could not be resolved by a widely used energy-dispersive X-ray spectrometer.

  8. 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…

  9. 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…

  10. 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.

  11. 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…

  12. Public health and Web 2.0.

    PubMed

    Hardey, Michael

    2008-07-01

    This article examines the nature and role of Web 2.0 resources and their impact on health information made available though the Internet. The transition of the Web from version one to Web 2.0 is described and the main features of the new Web examined. Two characteristic Web 2.0 resources are explored and the implications for the public and practitioners examined. First, what are known as 'user reviews' or 'user testimonials', which allow people to comment on the health services delivered to them, are described. Second, new mapping applications that take advantage of the interactive potential of Web 2.0 and provide tools to visualize complex data are examined. Following a discussion of the potential of Web 2.0, it is concluded that it offers considerable opportunities for disseminating health information and creating new sources of data, as well as generating new questions and dilemmas.

  13. Elastic and electron-capture processes in H{sup +}+C{sub 2}H{sub 4} collisions below the 10-keV regime

    SciTech Connect

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

    2005-03-01

    Electron capture and direct elastic scattering in collisions of H{sup +} ions with C{sub 2}H{sub 4} molecules are studied by using a molecular representation within a semiclassical as well as a fully quantum-mechanical approaches below 10 keV. Calculations are carried out at three different molecular configurations, in which H{sup +} approaches (i) parallel and (ii) perpendicular to the C=C axis in the molecular plane, and (iii) perpendicular to this plane. We find that electron capture in the (iii) configuration takes place preferentially over that in the (i) and (ii) configurations at scattering angles above 15 deg., while the results for (i) and (ii) are comparable in magnitude below 10 deg., although (ii) dominates slightly at still smaller angles. Total capture cross sections for the (iii) and (ii) configurations differ by a factor of 4 above 500 eV, while those for (i) lie between these values. Below 500 eV, the results for (i) and (iii) are similar in magnitude, while that for the (ii) configuration sharply decreases.

  14. Carbon Capture (Carbon Cycle 2.0)

    ScienceCinema

    Smit, Berend

    2016-07-12

    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/

  15. ROMUSE 2.0 User Manual

    SciTech Connect

    Khuwaileh, Bassam; Turinsky, Paul; Williams, Brian J.

    2016-10-04

    ROMUSE (Reduced Order Modeling Based Uncertainty/Sensitivity Estimator) is an effort within the Consortium for Advanced Simulation of Light water reactors (CASL) to provide an analysis tool to be used in conjunction with reactor core simulators, especially the Virtual Environment for Reactor Applications (VERA). ROMUSE is written in C++ and is currently capable of performing various types of parameters perturbations, uncertainty quantification, surrogate models construction and subspace analysis. Version 2.0 has the capability to interface with DAKOTA which gives ROMUSE access to the various algorithms implemented within DAKOTA. ROMUSE is mainly designed to interface with VERA and the Comprehensive Modeling and Simulation Suite for Nuclear Safety Analysis and Design (SCALE) [1,2,3], however, ROMUSE can interface with any general model (e.g. python and matlab) with Input/Output (I/O) format that follows the Hierarchical Data Format 5 (HDF5). In this brief user manual, the use of ROMUSE will be overviewed and example problems will be presented and briefly discussed. The algorithms provided here range from algorithms inspired by those discussed in Ref.[4] to nuclear-specific algorithms discussed in Ref. [3].

  16. 2 CFR 175.20 - Referral.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 2 Grants and Agreements 1 2014-01-01 2014-01-01 false Referral. 175.20 Section 175.20 Grants and Agreements Office of Management and Budget Guidance for Grants and Agreements OFFICE OF MANAGEMENT AND BUDGET GOVERNMENTWIDE GUIDANCE FOR GRANTS AND AGREEMENTS Reserved AWARD TERM FOR TRAFFICKING IN PERSONS §...

  17. 2 CFR 175.20 - Referral.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 2 Grants and Agreements 1 2012-01-01 2012-01-01 false Referral. 175.20 Section 175.20 Grants and Agreements Office of Management and Budget Guidance for Grants and Agreements OFFICE OF MANAGEMENT AND BUDGET GOVERNMENTWIDE GUIDANCE FOR GRANTS AND AGREEMENTS NATIONAL POLICY REQUIREMENTS AWARD TERM FOR TRAFFICKING...

  18. 2 CFR 175.20 - Referral.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 2 Grants and Agreements 1 2013-01-01 2013-01-01 false Referral. 175.20 Section 175.20 Grants and Agreements Office of Management and Budget Guidance for Grants and Agreements OFFICE OF MANAGEMENT AND BUDGET GOVERNMENTWIDE GUIDANCE FOR GRANTS AND AGREEMENTS NATIONAL POLICY REQUIREMENTS AWARD TERM FOR TRAFFICKING...

  19. 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.

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

    ScienceCinema

    Cheng, Robert K; Meza, Juan

    2016-07-12

    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/

  1. 20 CFR 355.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Definitions. 355.2 Section 355.2 Employees... UNDER THE PROGRAM FRAUD CIVIL REMEDIES ACT OF 1986 § 355.2 Definitions. ALJ means an Administrative Law... or statement is false, fictitious, or fraudulent; (b) Acts in deliberate ignorance of the truth...

  2. 20 CFR 435.2 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Definitions. 435.2 Section 435.2 Employees' Benefits SOCIAL SECURITY ADMINISTRATION UNIFORM ADMINISTRATIVE REQUIREMENTS FOR GRANTS AND AGREEMENTS WITH... cost rate. Working capital advance means a procedure in which funds are advanced to the recipient...

  3. 20 CFR 435.2 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Definitions. 435.2 Section 435.2 Employees' Benefits SOCIAL SECURITY ADMINISTRATION UNIFORM ADMINISTRATIVE REQUIREMENTS FOR GRANTS AND AGREEMENTS WITH... cost rate. Working capital advance means a procedure in which funds are advanced to the recipient...

  4. 20 CFR 900.2 - Establishment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Establishment. 900.2 Section 900.2 Employees' Benefits JOINT BOARD FOR THE ENROLLMENT OF ACTUARIES STATEMENT OF ORGANIZATION § 900.2 Establishment. The Joint Board has been established by the Secretary of Labor and the Secretary of the Treasury pursuant...

  5. 20 CFR 902.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Definitions. 902.2 Section 902.2 Employees' Benefits JOINT BOARD FOR THE ENROLLMENT OF ACTUARIES RULES REGARDING AVAILABILITY OF INFORMATION § 902.2 Definitions. (a) Records of the Joint Board. For purposes of this part, the term “records of the Joint...

  6. 20 CFR 903.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Definitions. 903.2 Section 903.2 Employees' Benefits JOINT BOARD FOR THE ENROLLMENT OF ACTUARIES ACCESS TO RECORDS Records Pertaining to Individuals § 903.2 Definitions. (a) The term agency includes any executive department, military...

  7. 20 CFR 435.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Definitions. 435.2 Section 435.2 Employees' Benefits SOCIAL SECURITY ADMINISTRATION UNIFORM ADMINISTRATIVE REQUIREMENTS FOR GRANTS AND AGREEMENTS WITH..., colleges, and other non-profit institutions. “Research” is defined as a systematic study directed...

  8. 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)%.

  9. Global Impacts (Carbon Cycle 2.0)

    ScienceCinema

    Gadgil, Ashok [EETD and UC Berkeley

    2016-07-12

    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/

  10. Differential scattering cross sections for collisions of 0.5-, 1.5-, and 5.0-keV helium atoms with He, H2, N2, and O2. [for atmospheric processes modeling

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    This paper reports the first results of an experimental program established to provide cross section data for use in modeling various atmospheric processes. Absolute cross sections, differential in the scattering angle, have been measured for collisions of 0.5-, 1.5-, and 5.0-keV helium atoms with He, H2, N2, and O2 at laboratory scattering angles between 0.1 deg and 5 deg. The results are the sums of cross sections for elastic and inelastic scattering of helium atoms; charged collision products are not detected. Integration of the differential cross section data yields integral cross sections consistent with measurements by other workers. The apparatus employs a position-sensitive detector for both primary and scattered particles and uses a short target cell with a large exit aperture to ensure a simple and well-defined apparatus geometry.

  11. 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.

  12. 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...

  13. 20 CFR 302.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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,...

  18. 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,...

  19. 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,...

  20. 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,...

  1. 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,...

  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

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Gulf of Maine off Cape Small, 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)...

  3. 33 CFR 334.20 - Gulf of Maine off Cape Small, Maine; naval aircraft practice mining range area.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Gulf of Maine off Cape Small, 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)...

  4. 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

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Gulf of Maine off Cape Small, 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)...

  5. 33 CFR 334.20 - Gulf of Maine off Cape Small, Maine; naval aircraft practice mining range area.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Gulf of Maine off Cape Small, 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)...

  6. 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

  7. Web 2.0 and pharmacy education.

    PubMed

    Cain, Jeff; Fox, Brent I

    2009-11-12

    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.

  8. World Wide Web Astronomy 2.0

    NASA Astrophysics Data System (ADS)

    Koppelman, M.; Gay, P. L.

    2008-11-01

    The Internet has changed astronomy. It's changed research, outreach and education and it's changed how people consume astronomy as enthusiasts. People have new ways to talk to each other and new ways to participate. Coined ``Web 2.0,'' technologies such as blogs, social networks, wikis, photo and video sharing sites, podcasts and micro-blogging have been adopted by the astronomy community and exciting things are happening as a result. The International Year of Astronomy's New Media Task Force has been working to harness the excitement of ``Web 2.0'' to make the International Year of Astronomy (IYA2009) highly visible on the Internet around the world.

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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.

  15. Sustainable Systems SFA 2.0

    ScienceCinema

    Hubbard, Susan

    2016-07-12

    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.

  16. 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…

  17. 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,…

  18. Do Web 2.0 Right

    ERIC Educational Resources Information Center

    Light, Daniel

    2011-01-01

    The author and his colleague, Deborah Polin, traveled around the United States to get a first-hand look at how teachers are developing successful Web 2.0 activities for their classrooms. With funding from Intel, they interviewed 39 educators in 22 schools throughout the country about how they employed these tools in their classrooms in innovative…

  19. 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…

  20. SFA 2.0- Metabolic Potential

    ScienceCinema

    Banfield, Jill; Beller, Harry

    2016-07-12

    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.

  1. Internet2 and the K20 Initiative.

    ERIC Educational Resources Information Center

    Van Horn, Royal

    2002-01-01

    Describes the status of the K20 initiative, efforts to extend the advantages of the high-speed Internet2 (largely for research universities) to K-12 schools, state education networks, and teaching-oriented universities. Includes cost and requirements to join the initiative. (PKP)

  2. 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

  3. 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.

  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

    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.

  5. 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.

  6. 20-element HgI[sub 2] energy dispersive x-ray array detector system

    SciTech Connect

    Iwanczyk, J.S.; Dorri, N.; Wang, M.; Szczebiot, R.W.; Dabrowski, A.J. ); Hedman, B.; Hodgson, K.O. . Stanford Synchrotron Radiation Lab.); Patt, B.E. )

    1992-10-01

    This paper describes recent progress in the development of HgI[sub 2] energy dispersive x-ray 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 alpha]) 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 form diluted samples simulating proteins with nickel.

  7. 20 element HgI sub 2 energy dispersive x-ray array detector system

    SciTech Connect

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

    1991-01-01

    This paper describes recent progress in the development of HgI{sub 2} 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.

  8. 20 element HgI{sub 2} energy dispersive x-ray array detector system

    SciTech Connect

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

    1991-12-31

    This paper describes recent progress in the development of HgI{sub 2} 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.

  9. 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,…

  10. 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.

  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. 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.

  13. 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.

  14. Detection of 1 - 100 keV x-rays from high intensity, 500 fs laser- produced plasmas using charge-coupled devices

    SciTech Connect

    Dunn, J.; Young, B.K.F.; Conder, A.D.; Stewart, R.E.

    1996-01-01

    We describe a compact, vacuum compatible, large format, charge- coupled device (CCD) camera for scientific imaging and detection of 1- 100 keV x rays in experiments at LLNL JANUS-1ps laser. A standard, front-illuminated, multi-pin phase device with 250 k electron full well capacity, low dark current (10 pA/cm{sup 2} at 20 C) and low read noise (5 electron rms) is cooled to -35 C to give the camera excellent 15-bit dynamic range and signal-to-noise response. Intensity and x-ray energy linear response were determined for optical and x-ray (<65 keV) photons and are in excellent agreement. Departure from linearity was less than 0.7%. Inherent linearity and energy dispersive characteristics of CCD cameras are well suited for hard x-ray photon counting. X-rays absorbed within the depletion and field-free regions can be distinguished by studying the pulse height spectrum. Results are presented for the detection of 1-100 keV Bremsstrahlung continuum, K-shell and L-shell fluorescence spectra emitted from high intensity (10{sup 18}W cm{sup -2}), 500 fs laser- produced plasmas.

  15. Short- and medium-range order in Zr[subscript 80]Pt[subscript 20] liquids

    SciTech Connect

    Mauro, N.A.; Wessels, V.; Bendert, J.C.; Klein, S.; Gangopadhyay, A.K.; Kramer, M.J.; Hao, S.G.; Rustan, G.E.; Kreyssig, A.; Goldman, A.I.; Kelton, K.F.

    2011-12-09

    The atomic structures in equilibrium and supercooled liquids of Zr{sub 80}Pt{sub 20} were determined as a function of temperature by in situ high-energy synchrotron diffraction studies of the levitated liquids (containerless processing) using the beamline electrostatic levitation (BESL) technique. The presence of a pronounced pre-peak at q - 1.7 {angstrom}{sup -1} in the static structure factor indicates medium-range order (MRO) in the liquid. The position and intensity of the pre-peak remain constant with cooling, indicating that the MRO is already present in the liquid above its melting temperature. An analysis of the liquid atomic structures obtained using the Reverse Monte Carlo method utilizing both the structure factor S(q) from x-ray diffraction experiments and the partial pair-correlation functions from ab initio molecular dynamics simulations show that the pre-peak arises from a Pt-Pt correlation that can be identified with icosahedral short-range order around the Pt atoms. The local atomic ordering is dominated by icosahedral-like structures, raising the nucleation barrier between the liquid and these phases, thus assisting glass formation.

  16. Health 2.0 and Medicine 2.0: Tensions and Controversies in the Field

    PubMed Central

    Joshi, Indra; Wareham, Jonathan

    2008-01-01

    Background The term Web 2.0 became popular following the O’Reilly Media Web 2.0 conference in 2004; however, there are difficulties in its application to health and medicine. Principally, the definition published by O’Reilly is criticized for being too amorphous, where other authors claim that Web 2.0 does not really exist. Despite this skepticism, the online community using Web 2.0 tools for health continues to grow, and the term Medicine 2.0 has entered popular nomenclature. Objective This paper aims to establish a clear definition for Medicine 2.0 and delineate literature that is specific to the field. In addition, we propose a framework for categorizing the existing Medicine 2.0 literature and identify key research themes, underdeveloped research areas, as well as the underlying tensions or controversies in Medicine 2.0’s diverse interest groups. Methods In the first phase, we employ a thematic analysis of online definitions, that is, the most important linked papers, websites, or blogs in the Medicine 2.0 community itself. In a second phase, this definition is then applied across a series of academic papers to review Medicine 2.0’s core literature base, delineating it from a wider concept of eHealth. Results The terms Medicine 2.0 and Health 2.0 were found to be very similar and subsume five major salient themes: (1) the participants involved (doctors, patients, etc); (2) its impact on both traditional and collaborative practices in medicine; (3) its ability to provide personalized health care; (4) its ability to promote ongoing medical education; and (5) its associated method- and tool-related issues, such as potential inaccuracy in enduser-generated content. In comparing definitions of Medicine 2.0 to eHealth, key distinctions are made by the collaborative nature of Medicine 2.0 and its emphasis on personalized health care. However, other elements such as health or medical education remain common for both categories. In addition, this emphasis on

  17. 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

  18. 43 CFR 4120.3-2 - Cooperative range improvement agreements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Cooperative range improvement agreements...) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR RANGE MANAGEMENT (4000) GRAZING ADMINISTRATION-EXCLUSIVE OF ALASKA Grazing Management § 4120.3-2 Cooperative range improvement agreements. (a) The...

  19. 43 CFR 4120.3-2 - Cooperative range improvement agreements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Cooperative range improvement agreements...) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR RANGE MANAGEMENT (4000) GRAZING ADMINISTRATION-EXCLUSIVE OF ALASKA Grazing Management § 4120.3-2 Cooperative range improvement agreements. (a) The...

  20. 43 CFR 4120.3-2 - Cooperative range improvement agreements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Cooperative range improvement agreements...) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR RANGE MANAGEMENT (4000) GRAZING ADMINISTRATION-EXCLUSIVE OF ALASKA Grazing Management § 4120.3-2 Cooperative range improvement agreements. (a) The...

  1. 43 CFR 4120.3-2 - Cooperative range improvement agreements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Cooperative range improvement agreements...-EXCLUSIVE OF ALASKA Grazing Management § 4120.3-2 Cooperative range improvement agreements. (a) The Bureau of Land Management may enter into a cooperative range improvement agreement with a...

  2. The Search for 17-KEV Neutrino Emission in the Beta-Decay Spectrum of SULFUR-35.

    NASA Astrophysics Data System (ADS)

    Berman, Gregg Evan

    For this work, the electron momentum spectrum resulting from the beta-decay of ^{35}S, ^{35}{rm S} to ^ {35}{rm Cl} + {rm e }^- + |nu_{rm e}quad (E_0 - m_{e} = 167 {rm keV, T}_{1/2 } = 87.4 {rm days}), has been measured in order to search for the presence of 17-keV electron neutrino emission. Originally observed by J. Simpson in 1985, evidence supporting a 1% 17-keV neutrino branch in the decay spectra of ^3 H, ^{35}S, ^{63}Ni, ^{55 }Fe, ^{14}C and ^{71}Ge has since been reported. However, other groups observing these nuclei have not seen any evidence of 17-keV neutrino emission, and very stringent limits ruling out a 1% branch have been published. Therefore, an important goal of this work is to reduce and/or understand experimental systematic errors that can mask or mimic the effects of a 17-keV neutrino. This ^{35}S spectrum measurement was performed using Princeton's extensively renovated, iron-free, intermediate-image, magnetic spectrometer. To ensure radio-chemical purity, the ^{35 }S source was prepared by ion-implantation using an isotope separator. To accurately determine the overall response of the spectrometer, electron data was accumulated over the very wide energy range of 40-167 keV. In addition, a detailed study of the spectrometer response using various ^{111}In calibration sources was undertaken, and the effects of source positioning and background magnetic fields have been explored. Furthermore, new computer codes for electron orbit raytracing and Monte-Carlo simulations have been developed to help further study the response of the spectrometer as well as to predict the effects of electron backscattering in both the source and detector substrates. To analyze the experimental data for the presence of a 17-keV neutrino branch, the measured ^ {35}S spectrum was convolved with the overall response of the spectrometer, and then fit by least -squares reduction to a theoretical beta -decay shape that allows heavy-neutrino mixing. The results show that the

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

    ScienceCinema

    Bill Collins

    2016-07-12

    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/

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

    ScienceCinema

    Alivisatos, Paul

    2016-07-12

    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/

  5. Compton polarimetry detection of small circularly and linearly polarized impurities in Mössbauer 8.4 keV (3/2-1/2) M1 γ-transition of 169Tm

    NASA Astrophysics Data System (ADS)

    Tsinoev, V.; Cherepanov, V.; Shuvalov, V.; Balysh, A.; Gabbasov, R.

    2016-12-01

    The arrangement of an experiment to detect the P-odd and P, T-odd polarized part of the Mössbauer (+3/2- +1/2) gamma transition of a deformed 169Tm nucleus with an energy of 8.4 keV by Compton polarimetry is discussed. Tm 2O3 single crystal with a quadrupolarly split Mössbauer spectrum is proposed as a resonance polarizer. A Be-scatterer-based Compton polarimeter and a synchronously detecting system will be used to measure the P-odd circular polarization P C and P, T-odd linear polarization P L .The expected accuracy of measuring the relative magnitude of the P, T-odd contribution is about 1% of the magnitude of usual weak nucleon-nucleon interaction.

  6. 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.

  7. [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.

  8. Bringing Web 2.0 to bioinformatics.

    PubMed

    Zhang, Zhang; Cheung, Kei-Hoi; Townsend, Jeffrey P

    2009-01-01

    Enabling deft data integration from numerous, voluminous and heterogeneous data sources is a major bioinformatic challenge. Several approaches have been proposed to address this challenge, including data warehousing and federated databasing. Yet despite the rise of these approaches, integration of data from multiple sources remains problematic and toilsome. These two approaches follow a user-to-computer communication model for data exchange, and do not facilitate a broader concept of data sharing or collaboration among users. In this report, we discuss the potential of Web 2.0 technologies to transcend this model and enhance bioinformatics research. We propose a Web 2.0-based Scientific Social Community (SSC) model for the implementation of these technologies. By establishing a social, collective and collaborative platform for data creation, sharing and integration, we promote a web services-based pipeline featuring web services for computer-to-computer data exchange as users add value. This pipeline aims to simplify data integration and creation, to realize automatic analysis, and to facilitate reuse and sharing of data. SSC can foster collaboration and harness collective intelligence to create and discover new knowledge. In addition to its research potential, we also describe its potential role as an e-learning platform in education. We discuss lessons from information technology, predict the next generation of Web (Web 3.0), and describe its potential impact on the future of bioinformatics studies.

  9. Clusterix 2.0 for Gaia

    NASA Astrophysics Data System (ADS)

    Balaguer-Núez, L.; Galadí-Enríquez, D.; López del Fresno, M.; Solano, E.; Jordi, C.; Sézima, T.; Paunzen, E.

    2017-03-01

    We present an advanced, VO-compliant version of Clusterix, a tool for the determination of membership probabilities in stellar clusters from proper motion data. Clusterix is a web-based, interactive application that allows the computation of membership probabilities from proper motions through a fully non-parametric method. Version 1.0 (http://clusterix.cerit-sc.cz/) was developed as a collaboration between the Masaryk University (Czech Republic) and the Universitat de Barcelona (Spain), as a complement to the WEBDA (http://webda.physics.muni.cz) database of observational data on stars in open clusters. Clusterix 2.0 (http://clusterix.cab.inta-csic.es/clusterix/) is oriented towards the exploitation of Gaia data products. With the participation of the Spanish Virtual Observatory, Clusterix now features an improved user interface for a faster, easier and more accurate interactive definition of the cluster and field proper motion distributions. The system provides fast feedback between membership probability determinations and the distribution of observables for the most probable members and field stars, with graphic tools to display, for instance, photometric diagrams on the fly. Furthermore, Clusterix 2.0 is fully VO-compatible, what opens interesting prospects for the astrophysical exploitation of the improved membership probabilities that will be capable to provide for many open clusters observed by Gaia.

  10. X-ray spectroscopy for chemistry in the 2-4 keV energy regime at the XMaS beamline: ionic liquids, Rh and Pd catalysts in gas and liquid environments, and Cl contamination in γ-Al2O3.

    PubMed

    Thompson, Paul B J; Nguyen, Bao N; Nicholls, Rachel; Bourne, Richard A; Brazier, John B; Lovelock, Kevin R J; Brown, Simon D; Wermeille, Didier; Bikondoa, Oier; Lucas, Christopher A; Hase, Thomas P A; Newton, Mark A

    2015-11-01

    The 2-4 keV energy range provides a rich window into many facets of materials science and chemistry. Within this window, P, S, Cl, K and Ca K-edges may be found along with the L-edges of industrially important elements from Y through to Sn. Yet, compared with those that cater for energies above ca. 4-5 keV, there are relatively few resources available for X-ray spectroscopy below these energies. In addition, in situ or operando studies become to varying degrees more challenging than at higher X-ray energies due to restrictions imposed by the lower energies of the X-rays upon the design and construction of appropriate sample environments. The XMaS beamline at the ESRF has recently made efforts to extend its operational energy range to include this softer end of the X-ray spectrum. In this report the resulting performance of this resource for X-ray spectroscopy is detailed with specific attention drawn to: understanding electrostatic and charge transfer effects at the S K-edge in ionic liquids; quantification of dilution limits at the Cl K- and Rh L3-edges and structural equilibria in solution; in vacuum deposition and reduction of [Rh(I)(CO)2Cl]2 to γ-Al2O3; contamination of γ-Al2O3 by Cl and its potential role in determining the chemical character of supported Rh catalysts; and the development of chlorinated Pd catalysts in `green' solvent systems. Sample environments thus far developed are also presented, characterized and their overall performance evaluated.

  11. Mass spectrometry and Web 2.0.

    PubMed

    Murray, Kermit K

    2007-10-01

    The term Web 2.0 is a convenient shorthand for a new era in the Internet in which users themselves are both generating and modifying existing web content. Several types of tools can be used. With social bookmarking, users assign a keyword to a web resource and the collection of the keyword 'tags' from multiple users form the classification of these resources. Blogs are a form of diary or news report published on the web in reverse chronological order and are a popular form of information sharing. A wiki is a website that can be edited using a web browser and can be used for collaborative creation of information on the site. This article is a tutorial that describes how these new ways of creating, modifying, and sharing information on the Web are being used for on-line mass spectrometry resources.

  12. 20 CFR 418.2115 - What are the modified adjusted gross income ranges?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... ranges? 418.2115 Section 418.2115 Employees' Benefits SOCIAL SECURITY ADMINISTRATION MEDICARE SUBSIDIES... Income-Related Monthly Adjustment Amount § 418.2115 What are the modified adjusted gross income ranges? (a) We list the modified adjusted gross income ranges for the calendar years 2011 through...

  13. 20 CFR 418.2115 - What are the modified adjusted gross income ranges?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... ranges? 418.2115 Section 418.2115 Employees' Benefits SOCIAL SECURITY ADMINISTRATION MEDICARE SUBSIDIES... Income-Related Monthly Adjustment Amount § 418.2115 What are the modified adjusted gross income ranges? (a) We list the modified adjusted gross income ranges for the calendar years 2011 through...

  14. 20 CFR 418.1115 - What are the modified adjusted gross income ranges?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... ranges? 418.1115 Section 418.1115 Employees' Benefits SOCIAL SECURITY ADMINISTRATION MEDICARE SUBSIDIES... Adjustment Amount § 418.1115 What are the modified adjusted gross income ranges? (a) We list the modified adjusted gross income ranges for the calendar years 2011 through and including 2019 for each Federal...

  15. 20 CFR 418.1115 - What are the modified adjusted gross income ranges?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... ranges? 418.1115 Section 418.1115 Employees' Benefits SOCIAL SECURITY ADMINISTRATION MEDICARE SUBSIDIES... Adjustment Amount § 418.1115 What are the modified adjusted gross income ranges? (a) The 2007 modified adjusted gross income ranges for each Federal tax filing category are listed in paragraphs (b), (c) and...

  16. 20 CFR 418.1115 - What are the modified adjusted gross income ranges?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... ranges? 418.1115 Section 418.1115 Employees' Benefits SOCIAL SECURITY ADMINISTRATION MEDICARE SUBSIDIES... Adjustment Amount § 418.1115 What are the modified adjusted gross income ranges? (a) The 2007 modified adjusted gross income ranges for each Federal tax filing category are listed in paragraphs (b), (c) and...

  17. 20 CFR 418.1115 - What are the modified adjusted gross income ranges?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... ranges? 418.1115 Section 418.1115 Employees' Benefits SOCIAL SECURITY ADMINISTRATION MEDICARE SUBSIDIES... Adjustment Amount § 418.1115 What are the modified adjusted gross income ranges? (a) The 2007 modified adjusted gross income ranges for each Federal tax filing category are listed in paragraphs (b), (c) and...

  18. 20 CFR 418.1115 - What are the modified adjusted gross income ranges?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... ranges? 418.1115 Section 418.1115 Employees' Benefits SOCIAL SECURITY ADMINISTRATION MEDICARE SUBSIDIES... Adjustment Amount § 418.1115 What are the modified adjusted gross income ranges? (a) The 2007 modified adjusted gross income ranges for each Federal tax filing category are listed in paragraphs (b), (c) and...

  19. 20 CFR 418.2115 - What are the modified adjusted gross income ranges?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... ranges? 418.2115 Section 418.2115 Employees' Benefits SOCIAL SECURITY ADMINISTRATION MEDICARE SUBSIDIES... Income-Related Monthly Adjustment Amount § 418.2115 What are the modified adjusted gross income ranges? (a) We list the modified adjusted gross income ranges for the calendar years 2011 through...

  20. 20 CFR 418.2115 - What are the modified adjusted gross income ranges?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... ranges? 418.2115 Section 418.2115 Employees' Benefits SOCIAL SECURITY ADMINISTRATION MEDICARE SUBSIDIES... Income-Related Monthly Adjustment Amount § 418.2115 What are the modified adjusted gross income ranges? (a) We list the modified adjusted gross income ranges for the calendar years 2011 through...

  1. Measurements of proton induced γ-ray emission cross sections on MgF2 target in the energy range 1.95-3.05 MeV

    NASA Astrophysics Data System (ADS)

    Zamboni, I.; Siketić, Z.; Jakšić, M.; Bogdanović Radović, I.

    2015-01-01

    In this work we present differential cross sections for γ-ray emission from the reactions 19F(p,p‧γ)19F (Eγ = 110, 197, 1236 and 1349 + 1357 keV), 24Mg(p,p‧γ)24Mg (Eγ = 1369 keV) and 25Mg(p,p‧γ)25Mg (Eγ = 390, 585 and 975 keV). Differential cross sections were measured for proton energies from 1.95 to 3.05 MeV with a 15 keV step and beam energy resolution of 0.06%. Thin reference standard, 54.1 μg/cm2 of MgF2 deposited on thin Mylar foil with additionally evaporated 4 nm Au layer, was used as a target. The γ-rays were detected by a 20% relative efficiency HPGe detector placed at an angle of 135° with respect to the beam direction, while the backscattered protons were collected using silicon surface barrier detector placed at the scattering angle of 165°. Obtained cross sections were compared with the previously measured data available from the literature.

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

    ScienceCinema

    Alivisatos, Paul

    2016-07-12

    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/

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

    ScienceCinema

    Collins, Bill

    2016-07-12

    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/

  4. 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.

  5. Fecal 20-oxo-pregnane concentrations in free-ranging African elephants (Loxodonta africana) treated with porcine zona pellucida vaccine.

    PubMed

    Ahlers, M J; Ganswindt, A; Münscher, S; Bertschinger, H J

    2012-07-01

    Because of overpopulation of African elephants in South Africa and the consequent threat to biodiversity, the need for a method of population control has become evident. In this regard, the potential use of the porcine zona pellucida (pZP) vaccine as an effective means for population control is explored. While potential effects of pZP treatment on social behavior of African elephants have been investigated, no examination of the influence of pZP vaccination on the endocrine correlates in treated females has been undertaken. In this study, ovarian activity of free-ranging, pZP-treated African elephant females was monitored noninvasively for 1 yr at Thornybush Private Nature Reserve, South Africa, by measuring fecal 5α-pregnan-3β-ol-20-on concentrations via enzyme immunoassay. A total of 719 fecal samples from 19 individuals were collected over the study period, averaging 38 samples collected per individual (minimum, maximum: 16, 52). Simultaneously, behavioral observations were made to record the occurrence of estrous behavior for comparison. Each elephant under study showed 5α-pregnan-3β-ol-20-on concentrations rising above baseline at some period during the study indicating luteal activity. Average 5α-pregnan-3β-ol-20-on concentrations were 1.61 ± 0.46 μg/g (mean ± SD). Within sampled females, 42.9% exhibited estrous cycles within the range reported for captive African elephants, 14.3% had irregular cycles, and 42.9% did not appear to be cycling. Average estrous cycle duration was 14.72 ± 0.85 wk. Estrous behavior coincided with the onset of the luteal phase and a subsequent rise in 5α-pregnan-3β-ol-20-on concentrations. Average 5α-pregnan-3β-ol-20-on levels positively correlated with rainfall. No association between average individual 5α-pregnan-3β-ol-20-on concentrations or cyclicity status with age or parity were detected. Earlier determination of efficacy was established via fecal hormone analysis with no pregnancies determined 22 mo post

  6. 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.

  7. Extensional Lower Cretaceous volcanism in the Coastal Range (29°20'-30°S), Chile: geochemistry and petrogenesis

    NASA Astrophysics Data System (ADS)

    Morata, D.; Aguirre, L.

    2003-12-01

    Lower Cretaceous volcanism in the Coastal Range (29°20'-30°S) of Chile is mainly represented by highly porphyritic (20-30% phenocrysts) lavas with unzoned Ca-rich plagioclase (An 57-54Ab 40-42Or 3-4), clinopyroxene (Wo 40En 43Fs 17), magnetite, and minor idiomorphic, altered olivines. Geochemically, these lavas are characterized by a relative homogeneity with high Al 2O 3 and low MgO contents, and classified as high-K to shoshonitic basaltic andesites to andesites generated in an intra-arc extensional setting due to oblique subduction. Their isotopic geochemistry is characterized by highly homogeneous low initial Sr ratios (( 87Sr/ 86Sr) 0˜0.7036) and positive ɛNd values ( ɛNd=+2.9 to +4.7 ( 143Nd/ 144Nd) 0˜0.5127) that are very different from those proposed as representative of 'Andean-type' magmatism. A non-Andean modern setting dominated by subduction associated with intra-arc extension is proposed. On a ( 87Sr/ 86Sr) 0 versus ɛNd diagram, these lavas fit a model mixing curve for which the end members are Pacific MORB and Jurassic plutonic rocks from the Coastal Range. Coeval granitoids from the Coastal Range and lavas from the High Andes plot on the same field. Isotopically depleted mafic magmas could be metasomatized by the subducted sediments, which would increase their LILE content, and then partially contaminated by Jurassic plutonic rocks. The genesis of this magmatism may be related to a global low-spreading rate of 5 cm yr -1 in the southeast Pacific during 125-110 Ma.

  8. 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.

  9. High-dynamic-range linear analog data links (1-20 GHz) using room temperature DFB laser diodes

    NASA Astrophysics Data System (ADS)

    White, Ian H.; Hartmann, Peter; Ingham, Jonathan D.; Webster, Matthew; Wake, David; Wonfor, Adrian; Penty, Richard V.; Seeds, Alwyn J.; White, J. Kenton

    2004-02-01

    We report the analysis and application of uncooled, directly-modulated high-speed DFB lasers with emphasis on their analogue transmission performance. Fibre-optic links employing such lasers are shown to meet the most stringent requirements of analogue systems at both high carrier frequencies and high temperatures. Spurious-free dynamic ranges (SFDR) exceeding 100dB×Hz2/3 and 90dB×Hz2/3 and input third-order intercept points (IIP3) above 20dBm and 18dBm are reported for carrier frequencies up to 20GHz at 25°C and up to 10GHz at 85°C, respectively. The error-vector magnitude (EVM) for a 256-QAM modulated signal transmitted over 15km of SMF remains below 1.9% for carrier frequencies of both 2GHz and 5GHz for all measured temperatures. The link performance is assessed by using 3GPP W-CDMA, IEEE 802.11a and IEEE 802.11b signals. In all cases the EVM remains within the standard specification, for fibre-optic link lengths of up to 10km and laser operating temperatures of up to 70°C. Finally, an IEEE 802.11b WLAN demonstrator is presented, allowing antenna remoting over up to 1000m of 62.5/125μm MMF.

  10. Merged Sounding VAP Version 2.0

    SciTech Connect

    Troyan, D.; Jensen, M.; Turner, D.; Miloshevich, L.

    2010-03-15

    The Merged Sounding Value-Added Product (VAP) has been in the ARM and ASR pipeline since 2001. Output data streams have been added to the Evaluation Products section of the ARM website for the past five years. Currently, there are data for all of the ACRF fixed sites and all deployments of the Mobile Facility. Fifty-three years of Merged Sounding data is available as an evaluation product. The process of moving all to the ARM Data Archive has been started and will be completed shortly. A second version of the Merged Sounding VAP was developed to address several concerns: (1) Vaisala radiosondes have inherent problems obtaining an accurate measurement of relative humidity, (2) the profile can be extended from 20 km to 60 km above ground level based upon the height achieved by ECMWF profiles, and (3) ECMWF temperatures require adjustments at high altitude (between 1mb and 100 mb). Solutions to these issues have been incorporated in the new version of this VAP. Along with producing that second version of Merged Sounding, a secondary data stream - Sonde Adjust - was created. This VAP incorporates any humidity corrections to the Vaisala RS-80, RS-90, and RS-92 radiosondes. The algorithms used to perform these corrections are documented by Wang et. al. (2002), Turner et. al. (2003), and Miloshevich et. al. (2004, 2009).

  11. 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

  12. 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…

  13. 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

  14. 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…

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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.

  1. 20 CFR 631.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... apply to programs under Title III of the Act and this part: Substantial layoff (for participant... (excluding employees regularly working less than 20 hours per week). Substantial layoff (for rapid...

  2. Diode-laser-based high-precision absolute distance interferometer of 20 m range.

    PubMed

    Pollinger, Florian; Meiners-Hagen, Karl; Wedde, Martin; Abou-Zeid, Ahmed

    2009-11-10

    We present a hybrid absolute distance measurement method that is based on a combination of frequency sweeping, variable synthetic, and two-wavelength, fixed synthetic wavelength interferometry. Both experiments were realized by two external cavity diode lasers. The measurement uncertainty was experimentally and theoretically demonstrated to be smaller than 12 microm at a measurement distance of 20 m.

  3. Microbeam of 100 keV x ray with a sputtered-sliced Fresnel zone plate

    NASA Astrophysics Data System (ADS)

    Kamijo, Nagao; Suzuki, Yoshio; Takano, Hidekazu; Tamura, Shigeharu; Yasumoto, Masato; Takeuchi, Akihisa; Awaji, Mitsuhiro

    2003-12-01

    Microfocusing of 100 keV x ray with a sputtered-sliced Fresnel zone plate (ss-FZP) has been performed at the 250-m-long beamline (20XU) of SPring-8. The ss-FZP with an outermost zone width 0.16 μm which is composed of 70 layers of alternating Cu and Al layers and having thickness ˜180 μm was fabricated and characterized. The minimum focal spot size attained for the first order focal beam was 0.5 μm with a focal distance 900 mm at a photon energy 100 keV. The total flux of the microprobe was ˜2×106 photons s-1 μm-2.

  4. 41 CFR 60-20.2 - Recruitment and advertisement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... advertisement. 60-20.2 Section 60-20.2 Public Contracts and Property Management Other Provisions Relating to... OF LABOR 20-SEX DISCRIMINATION GUIDELINES § 60-20.2 Recruitment and advertisement. (a) Employers... occupation qualification. (b) Advertisement in newspapers and other media for employment must not express...

  5. Observational consistency and future predictions for a 3.5 keV ALP to photon line

    SciTech Connect

    Alvarez, Pedro D.; Conlon, Joseph P.; Day, Francesca V.; Marsh, M.C. David; Rummel, Markus

    2015-04-09

    Motivated by the possibility of explaining the 3.5 keV line through dark matter decaying to axion-like particles that subsequently convert to photons, we study ALP-photon conversion for sightlines passing within 50 pc of the galactic centre. Conversion depends on the galactic centre magnetic field which is highly uncertain. For fields at low or mid-range of observational estimates (10–100 μG), no observable signal is possible. For fields at the high range of observational estimates (a pervasive poloidal mG field over the central 150 pc) it is possible to generate sufficient signal to explain recent observations of a 3.5 keV line in the galactic centre. In this scenario, the galactic centre line signal comes predominantly from the region with z>20pc, reconciling the results from the Chandra and XMM-Newton X-ray telescopes. The dark matter to ALP to photon scenario also naturally predicts the non-observation of the 3.5 keV line in stacked galaxy spectra. We further explore predictions for the line flux in galaxies and suggest a set of galaxies that is optimised for observing the 3.5 keV line in this model.

  6. Stopping power and mean free path for low-energy electrons in ten scintillators over energy range of 20-20,000 eV.

    PubMed

    Tan, Zhenyu; Xia, Yueyuan

    2012-01-01

    Systematic calculations of the stopping powers (SP) and inelastic mean free paths (IMFP) for 20-20,000eV electrons in a group of 10 important scintillators have been carried out. The calculations are based on the dielectric model including the Born-Ochkur exchange correction and the optical energy loss functions (OELFs) are empirically evaluated because of the lack of available experimental optical data for the scintillators under consideration. The evaluated OELFs are examined by both the f-sum rule and the calculation of mean ionization potential. The SP and IMFP data presented here are the first results for the 10 scintillators over the energy range of 20-20,000eV, and are of key importance for the investigation of liquid scintillation counting.

  7. New x-ray parallel beam facility XPBF 2.0 for the characterization of silicon pore optics

    NASA Astrophysics Data System (ADS)

    Krumrey, Michael; Müller, Peter; Cibik, Levent; Collon, Max; Barrière, Nicolas; Vacanti, Giuseppe; Bavdaz, Marcos; Wille, Eric

    2016-07-01

    A new X-ray parallel beam facility (XPBF 2.0) has been installed in the laboratory of the Physikalisch-Technische Bundesanstalt at the synchrotron radiation facility BESSY II in Berlin to characterize silicon pore optics (SPOs) for the future X-ray observatory ATHENA. As the existing XPBF which is operated since 2005, the new beamline provides a pencil beam of very low divergence, a vacuum chamber with a hexapod system for accurate positioning of the SPO to be investigated, and a vertically movable CCD-based camera system to register the direct and the reflected beam. In contrast to the existing beamline, a multilayer-coated toroidal mirror is used for beam monochromatization at 1.6 keV and collimation, enabling the use of beam sizes between about 100 μm and at least 5 mm. Thus the quality of individual pores as well as the focusing properties of large groups of pores can be investigated. The new beamline also features increased travel ranges for the hexapod to cope with larger SPOs and a sample to detector distance of 12 m corresponding to the envisaged focal length of ATHENA.

  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.

  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. Spectrometry of the Rutherford backscattering of ions and the Raman scattering of light in GaS single crystals irradiated with 140-keV H{sub 2}{sup +} ions

    SciTech Connect

    Garibov, A. A.; Madatov, R. S.; Komarov, F. F.; Pilko, V. V.; Mustafayev, Yu. M.; Akhmedov, F. I.; Jakhangirov, M. M.

    2015-05-15

    The methods of the Raman scattering of light and Rutherford backscattering are used to study the degree of structural disorder in layered GaS crystals before and after irradiation with 140-keV H{sub 2}{sup +} ions. It is shown that the distribution of the crystal’s components over depth is homogeneous; for doses as high as 5 × 10{sup 15} cm{sup −2}, the stoichiometric composition of the compound’s components is retained. The experimental value of the critical dose for the beginning of amorphization amounts to about 5 × 10{sup 15} cm{sup −2} and is in accordance with the calculated value. The results obtained by the method of the Raman scattering of light confirm conservation of crystalline structure and the start of the amorphization process.

  13. The effectiveness of monoenergetic neutrons at 565 keV in producing dicentric chromosomes in human lymphocytes at low doses.

    PubMed

    Schmid, E; Regulla, D; Guldbakke, S; Schlegel, D; Bauchinger, M

    2000-09-01

    The induction of dicentric chromosomes in human lymphocytes from one individual irradiated in vitro with monoenergetic neutrons at 565 keV was examined to provide additional data for an improved evaluation of neutrons with respect to radiation risk in radioprotection. The resulting linear dose-response relationship obtained (0.813 +/- 0.052 dicentrics per cell per gray) over the dose range of 0.0213-0.167 Gy is consistent with published results obtained for irradiation with neutrons from different sources and with different spectra at energies lower than 1000 keV. Comparing this value to previously published "average" dose-response curves obtained by different laboratories for (60)Co gamma rays and orthovoltage X rays resulted in maximum RBEs (RBE(m)) of about 37 +/- 8 and 16 +/- 4, respectively. However, when our neutron data were matched to low-LET dose responses that were constructed several years earlier for lymphocytes from the same individual, higher values of RBE(m) resulted: 76.0 +/- 29.5 for (60)Co gamma rays and 54.2 +/- 18.4 for (137)Cs gamma rays; differentially filtered 220 kV X rays produced values of RBE(m) between 20.3 +/- 2.0 or 37.0 +/- 7. 1. The results highlight the dependence of RBE(m) on the choice of low-LET reference radiation and raise the possibility that differential individual response to low-LET radiations may need to be examined more fully in this context.

  14. Origins of Anisotropic 40 300 keV Electron Events Observed at Low and High Latitudes

    NASA Astrophysics Data System (ADS)

    Hawkins, S. E., III; Gold, R. E.; Pick, M.; Maia, D.

    2001-05-01

    Using a survey of anisotropic electron events in the energy range of ˜40 300 keV observed by HI-SCALE on Ulysses, we have selected several time intervals during 1999 when Ulysses traveled from about 20° S at 5.2 AU (January 1999) to 42° S at 4.2 AU (January 2000). We compare these events with observations at ˜1 AU using the nearly identical instrument, EPAM on ACE. In order to study the solar origins of these electrons using the imaging Nançay Radioheliograph, we further restricted the list of events to those in which interplanetary magnetic field lines with origins on the visible solar disk, intersected Ulysses. We find that not all the anisotropic electron events are observed by both spacecraft and there exists a strong dependence on the spacecraft's magnetic connection back to the Sun. We have identified the solar origin for five electron events using radio observations, and correlate these with interplanetary type-III radio emissions using the WIND/WAVES experiment.

  15. 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.

  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. 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...

  18. 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...

  19. 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…

  20. 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 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC VESSEL INSPECTIONS Reports and Forms § 2.20-40 Chief engineer's reports. (a) Repairs to boilers and pressure...

  1. 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.

  2. 1-to 10-keV x-ray backlighting of annular wire arrays on the Sandia Z-machine using bent-crystal imaging techniques.

    SciTech Connect

    Rambo, Patrick K.; Wenger, David Franklin; Bennett, Guy R.; Sinars, Daniel Brian; Smith, Ian Craig; Porter, John Larry, Jr.; Cuneo, Michael Edward; Rovang, Dean Curtis; Anderson, Jessica E.

    2003-07-01

    Annular wire array implosions on the Sandia Z-machine can produce >200 TW and 1-2 MJ of soft x rays in the 0.1-10 keV range. The x-ray flux and debris in this environment present significant challenges for radiographic diagnostics. X-ray backlighting diagnostics at 1865 and 6181 eV using spherically-bent crystals have been fielded on the Z-machine, each with a {approx}0.6 eVspectral bandpass, 10 {micro}m spatial resolution, and a 4 mm by 20mm field of view. The Z-Beamlet laser, a 2-TW, 2-kJ Nd:glass laser({lambda} = 527 nm), is used to produce 0.1-1 J x-ray sources for radiography. The design, calibration, and performance of these diagnostics is presented.

  3. Compact, maintainable 80-KeV neutral beam module

    DOEpatents

    Fink, Joel H.; Molvik, Arthur W.

    1980-01-01

    A compact, maintainable 80-keV arc chamber, extractor module for a neutral beam system immersed in a vacuum of <10.sup.-2 Torr, incorporating a nested 60-keV gradient shield located midway between the high voltage ion source and surrounding grounded frame. The shield reduces breakdown or arcing path length without increasing the voltage gradient, tends to keep electric fields normal to conducting surfaces rather than skewed and reduces the peak electric field around irregularities on the 80-keV electrodes. The arc chamber or ion source is mounted separately from the extractor or ion accelerator to reduce misalignment of the accelerator and to permit separate maintenance to be performed on these systems. The separate mounting of the ion source provides for maintaining same without removing the ion accelerator.

  4. 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.

  5. A high-accuracy dilatometer for the range -20 to 700°C

    NASA Astrophysics Data System (ADS)

    Edsinger, R. E.; Schooley, J. F.

    1991-07-01

    We have constructed a linear-thermal expansion apparatus that employs a potassium-loaded heat pipe to provide a homogeneous temperature environment for the sample and utilizes the Merritt-Saunders (optical interferometric) method of observing its expansion. The apparatus is similar in many respects to one described previously. Temperature regulation and measurement are accomplished through the use of a dedicated laboratory microcomputer operating with a simple program. Two platinum resistance thermometers, read automatically by a digital resistance bridge, provide, on command, both the temperature of the heat pipe and that of the sample chamber. Changes in sample length are determined from measurements of the corresponding changes of optical fringes from a Fizeau interferometer as recorded on film. The coefficients of thermal expansion of two Pt-Rh alloy samples determined using the present apparatus agree at the±2 ppm level with those determined for a similar sample using the previous apparatus.

  6. 1 CFR 20.2 - Preparation of agency statements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 1 General Provisions 1 2012-01-01 2012-01-01 false Preparation of agency statements. 20.2 Section 20.2 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER PREPARATION, TRANSMITTAL... Preparation of agency statements. In accordance with schedules established under § 20.7 each agency...

  7. 1 CFR 20.2 - Preparation of agency statements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 1 General Provisions 1 2011-01-01 2011-01-01 false Preparation of agency statements. 20.2 Section 20.2 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER PREPARATION, TRANSMITTAL... Preparation of agency statements. In accordance with schedules established under § 20.7 each agency...

  8. 1 CFR 20.2 - Preparation of agency statements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 1 General Provisions 1 2014-01-01 2012-01-01 true Preparation of agency statements. 20.2 Section 20.2 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER PREPARATION, TRANSMITTAL... Preparation of agency statements. In accordance with schedules established under § 20.7 each agency...

  9. 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.

  10. 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,...

  11. 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,...

  12. 20 CFR 703.2 - Forms.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...' 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,...

  13. 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,...

  14. 20 CFR 363.2 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... REMUNERATION OF BOARD PERSONNEL § 363.2 Definitions. (a) Child support means periodic payments of funds for the..., order, or judgment issued in accordance with applicable state law by a court of competent jurisdiction. (b) Alimony means periodic payments of funds for the support and maintenance of a spouse or...

  15. 20 CFR 350.2 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... § 350.2 Definitions. (a) Child support means periodic payments of funds for the support and maintenance... issued in accordance with applicable state law by a court of competent jurisdiction. (b) Alimony means periodic payments of funds for the support and maintenance of a spouse or former spouse and, subject to...

  16. 20 CFR 350.2 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... § 350.2 Definitions. (a) Child support means periodic payments of funds for the support and maintenance... issued in accordance with applicable state law by a court of competent jurisdiction. (b) Alimony means periodic payments of funds for the support and maintenance of a spouse or former spouse and, subject to...

  17. 20 CFR 363.2 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... REMUNERATION OF BOARD PERSONNEL § 363.2 Definitions. (a) Child support means periodic payments of funds for the..., order, or judgment issued in accordance with applicable state law by a court of competent jurisdiction. (b) Alimony means periodic payments of funds for the support and maintenance of a spouse or...

  18. 20 CFR 350.2 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... § 350.2 Definitions. (a) Child support means periodic payments of funds for the support and maintenance... issued in accordance with applicable state law by a court of competent jurisdiction. (b) Alimony means periodic payments of funds for the support and maintenance of a spouse or former spouse and, subject to...

  19. 20 CFR 363.2 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... REMUNERATION OF BOARD PERSONNEL § 363.2 Definitions. (a) Child support means periodic payments of funds for the..., order, or judgment issued in accordance with applicable state law by a court of competent jurisdiction. (b) Alimony means periodic payments of funds for the support and maintenance of a spouse or...

  20. 40 CFR 20.2 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Act, as amended (33 U.S.C. 1251 et seq.) or, when used in connection with air pollution control... of the Act. (2) For air pollution control facilities, the air pollution control agency designated pursuant to section 302(b)(1) of the Act; or (3) For both air and water pollution control facilities,...

  1. 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…

  2. 20 CFR 332.2 - General considerations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... MILEAGE OR WORK RESTRICTIONS AND STAND-BY OR LAY-OVER RULES § 332.2 General considerations. (a) Classes of... to an employee solely because of the application to him of a mileage or work restriction exist in train-and-engine service, yard service, dining-car service, sleeping-car service, and other...

  3. 20 CFR 332.2 - General considerations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... MILEAGE OR WORK RESTRICTIONS AND STAND-BY OR LAY-OVER RULES § 332.2 General considerations. (a) Classes of... to an employee solely because of the application to him of a mileage or work restriction exist in train-and-engine service, yard service, dining-car service, sleeping-car service, and other...

  4. 20 CFR 332.2 - General considerations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... MILEAGE OR WORK RESTRICTIONS AND STAND-BY OR LAY-OVER RULES § 332.2 General considerations. (a) Classes of... to an employee solely because of the application to him of a mileage or work restriction exist in train-and-engine service, yard service, dining-car service, sleeping-car service, and other...

  5. 20 CFR 206.2 - Computation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT ACCOUNT BENEFITS RATIO... the account benefits ratios for each of the most recent 10 preceding fiscal years; and (2) Certify the account benefits ratio for each such fiscal year to the Secretary of the Treasury. (b) On or...

  6. 20 CFR 206.2 - Computation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT ACCOUNT BENEFITS RATIO... the account benefits ratios for each of the most recent 10 preceding fiscal years; and (2) Certify the account benefits ratio for each such fiscal year to the Secretary of the Treasury. (b) On or...

  7. 20 CFR 206.2 - Computation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT ACCOUNT BENEFITS RATIO... the account benefits ratios for each of the most recent 10 preceding fiscal years; and (2) Certify the account benefits ratio for each such fiscal year to the Secretary of the Treasury. (b) On or...

  8. 20 CFR 206.2 - Computation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT ACCOUNT BENEFITS RATIO... the account benefits ratios for each of the most recent 10 preceding fiscal years; and (2) Certify the account benefits ratio for each such fiscal year to the Secretary of the Treasury. (b) On or...

  9. 20 CFR 206.2 - Computation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT ACCOUNT BENEFITS RATIO... the account benefits ratios for each of the most recent 10 preceding fiscal years; and (2) Certify the account benefits ratio for each such fiscal year to the Secretary of the Treasury. (b) On or...

  10. Department of Defense Joint Technical Architecture Version 2.0

    DTIC Science & Technology

    1998-05-26

    Transmission Format (Version 2.0) for the National Imagery Transmission Format Standard, 12 October 1994, Revised 7 February 1997. • MIL-STD-188...Mandates 2.1-5 2.1.4.1 Year 2000 (Y2K) Compliance 2.1-5 2.1.4.2 Defense Information Infrastructure Common Operating Environment (DU COE) 2.1-5 2.1.5...2.2.2.2.1.6 Communications Services 2.2-11 2.2.2.2.1.7 Operating System Services 2.2-11 2.2.2.2.2 Application Platform Cross-Area Services 2.2- 12

  11. 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.

  12. High Optical Access Trap 2.0.

    SciTech Connect

    Maunz, Peter Lukas Wilhelm

    2016-01-26

    The High Optical Access (HOA) trap was designed in collaboration with the Modular Universal Scalable Ion-trap Quantum Computer (MUSIQC) team, funded along with Sandia National Laboratories through IARPA's Multi Qubit Coherent Operations (MQCO) program. The design of version 1 of the HOA trap was completed in September 2012 and initial devices were completed and packaged in February 2013. The second version of the High Optical Access Trap (HOA-2) was completed in September 2014 and is available at IARPA's disposal.

  13. 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.

  14. Human category learning 2.0.

    PubMed

    Ashby, F Gregory; Maddox, W Todd

    2011-04-01

    During the 1990s and early 2000s, cognitive neuroscience investigations of human category learning focused on the primary goal of showing that humans have multiple category-learning systems and on the secondary goals of identifying key qualitative properties of each system and of roughly mapping out the neural networks that mediate each system. Many researchers now accept the strength of the evidence supporting multiple systems, and as a result, during the past few years, work has begun on the second generation of research questions-that is, on questions that begin with the assumption that humans have multiple category-learning systems. This article reviews much of this second generation of research. Topics covered include (1) How do the various systems interact? (2) Are there different neural systems for categorization and category representation? (3) How does automaticity develop in each system? and (4) Exactly how does each system learn?

  15. Registration characteristics of neutral particles with power 0.6 - 2.0 keV channel electron multiplier with funnel

    NASA Technical Reports Server (NTRS)

    Gruntman, M. A.; Kalinin, A. P.

    1978-01-01

    Operating a channel electron multiplier with a VEU-6 funnel shaped opening is studied. Different procedures were used when recording neutral particles. The results obtained make it possible to optimally use the multiplier in actual physical studies.

  16. UVIS 2.0: Ultraviolet Flats

    NASA Astrophysics Data System (ADS)

    Mack, J.

    2017-03-01

    Improved UV flat fields were delivered on February 23, 2016 for the four bluest WFC3 filters. These new reference files correct for sensitivity residuals in a crosshatch pattern on spatial scales of 50-100 pixels. The residuals are a result of in-flight temperature differences affecting the detector's spatial response, which was derived from ground test data at a warmer operating temperature. Photometry of white dwarf standards stepped across the UVIS detector shows a linear correlation between the flat field response and the measured flux residual, which is used to model the correction. With the 2016 flats, the photometric repeatability is now 3.0% peak-to-peak (0.7% rms) compared to 6.7% peak-to-peak (1.8% rms) with the original 2011 flats, excluding the left edge of the detector (x<300 pixels) in F275W where photometry is 1% higher than the rest of the frame. The UV filters have color terms of several percent, and the new chip-dependent calibration is intended to produce uniform count rate across the two chips for blue sources. When using the inverse sensitivity values delivered in February 2016, offsets in the UV count rate between chips of up to 2% are found for hot stars, and even more for cool stars. A revised calibration delivered in November 2016 corrects the offset for blue sources, allowing for more accurate drizzled data products when combining pixels from different UVIS chips.

  17. 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.

  18. 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.

  19. Magnetism in GdFe2Zn20

    NASA Astrophysics Data System (ADS)

    Antropov, Vladimir

    2007-03-01

    The magnetic structure formation and the origin of the exchange couplings in GdFe2Zn20 have been studied using the standard band-structure methods at T=0K and the ab-initio spin dynamics in the paramagnetic case. At low temperatures the relative importance of the different channels of the magnetic coupling have been analyzed. At high temperatures the soft spin deviation modes responsible for the observed high temperature of the magnetic phase transition [1] have been identified. Several strong magnetic short range order parameters have been found in this material. [1] S. Jia, S.L. Bud'ko, G.D. Samolyuk, P.C. Canfield. cond-mat/0606615

  20. 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

  1. SNR 1E 0102.2-7219 as an X-ray calibration standard in the 0.5-1.0 keV bandpass and its application to the CCD instruments aboard Chandra, Suzaku, Swift and XMM-Newton

    NASA Astrophysics Data System (ADS)

    Plucinsky, Paul P.; Beardmore, Andrew P.; Foster, Adam; Haberl, Frank; Miller, Eric D.; Pollock, Andrew M. T.; Sembay, Steve

    2017-01-01

    Context. The flight calibration of the spectral response of charge-coupled device (CCD) instruments below 1.5 keV is difficult in general because of the lack of strong lines in the on-board calibration sources typically available. This calibration is also a function of time due to the effects of radiation damage on the CCDs and/or the accumulation of a contamination layer on the filters or CCDs. Aims: We desire a simple comparison of the absolute effective areas of the current generation of CCD instruments onboard the following observatories: Chandra ACIS-S3, XMM-Newton (EPIC-MOS and EPIC-pn), Suzaku XIS, and Swift XRT and a straightforward comparison of the time-dependent response of these instruments across their respective mission lifetimes. Methods: We have been using 1E 0102.2-7219, the brightest supernova remnant in the Small Magellanic Cloud, to evaluate and modify the response models of these instruments. 1E 0102.2-7219 has strong lines of O, Ne, and Mg below 1.5 keV and little or no Fe emission to complicate the spectrum. The spectrum of 1E 0102.2-7219 has been well-characterized using the RGS gratings instrument on XMM-Newton and the HETG gratings instrument on Chandra. As part of the activities of the International Astronomical Consortium for High Energy Calibration (IACHEC), we have developed a standard spectral model for 1E 0102.2-7219 and fit this model to the spectra extracted from the CCD instruments. The model is empirical in that it includes Gaussians for the identified lines, an absorption component in the Galaxy, another absorption component in the SMC, and two thermal continuum components with different temperatures. In our fits, the model is highly constrained in that only the normalizations of the four brightest lines/line complexes (the O vii Heα triplet, O viii Lyα line, the Ne ix Heα triplet, and the Ne x Lyα line) and an overall normalization are allowed to vary, while all other components are fixed. We adopted this approach to

  2. Pathology in the era of Web 2.0.

    PubMed

    Schreiber, William E; Giustini, Dean M

    2009-12-01

    In the past few years, the term Web 2.0 has become a descriptor for the increased functionality of Web sites, including those with medical content. Most physicians do not know what Web 2.0 means or how it can impact their work lives. This review provides some background on the evolution of Web 2.0 and describes how its features are being incorporated into medical Web sites. Some potential applications of Web 2.0 in pathology and laboratory medicine are discussed, as are the issues that must be considered when adopting this new technology.

  3. Analysis of the TMI-2 source range detector response

    SciTech Connect

    Carew, J.F.; Diamond, D.J.; Eridon, J.M.

    1980-01-01

    In the first few hours following the TMI-2 accident large variations (factors of 10-100) in the source range (SR) detector response were observed. The purpose of this analysis was to quantify the various effects which could contribute to these large variations. The effects evaluated included the transmission of neutrons and photons from the core to detector and the reduction in the multiplication of the Am-Be startup sources, and subsequent reduction in SR detector response, due to core voiding. A one-dimensional ANISN slab model of the TMI-2 core, core externals, pressure vessel and containment has been constructed for calculation of the SR detector response and is presented.

  4. Fort Greely Missile Range Reference Atmosphere. Part 2

    DTIC Science & Technology

    1971-07-10

    Space Administration, United States Air Force, and United States Weather Bureau, G. P. O ., December 1962. 6. Smith, 0. E., and D. K . Weidner, "A...GEOPOTENTIAL SOUND meters meters doroee K mb gm-3 m sc-I 41250 O057.8 236t1 1.6250964 2.3896474 30A.557 435rC a3305. O 237.32 1.5632349 2.30 050" 308.823...MISSILE *I RANGE LAUNCH SiTE ST-F-TOGIELYA 392 163-5914 141343s W1 IMTS’ SEE COLUMN HEADffGS ALT rf P O metr, metr, doore K .3 n- a *c’ -r -- 5;e~z

  5. Measurement of high-energy (10–60 keV) x-ray spectral line widths with eV accuracy

    SciTech Connect

    Seely, J. F. Feldman, U.; Glover, J. L.; Hudson, L. T.; Ralchenko, Y.; Henins, Albert; Pereira, N.; Di Stefano, C. A.; Kuranz, C. C.; Drake, R. P.; Chen, Hui; Williams, G. J.; Park, J.

    2014-11-15

    A high resolution crystal spectrometer utilizing a crystal in transmission geometry has been developed and experimentally optimized to measure the widths of emission lines in the 10–60 keV energy range with eV accuracy. The spectrometer achieves high spectral resolution by utilizing crystal planes with small lattice spacings (down to 2d = 0.099 nm), a large crystal bending radius and Rowland circle diameter (965 mm), and an image plate detector with high spatial resolution (60 μm in the case of the Fuji TR image plate). High resolution W L-shell and K-shell laboratory test spectra in the 10–60 keV range and Ho K-shell spectra near 47 keV recorded at the LLNL Titan laser facility are presented. The Ho K-shell spectra are the highest resolution hard x-ray spectra recorded from a solid target irradiated by a high-intensity laser.

  6. Accretion Properties of a Sample of Hard X-Ray (<60 keV) Selected Seyfert 1 Galaxies

    NASA Astrophysics Data System (ADS)

    Wang, J.; Mao, Y. F.; Wei, J. Y.

    2009-02-01

    We examine the accretion properties in a sample of 42 hard (3-60 keV) X-ray selected nearby broad-line active galactic nuclei (AGNs). The energy range in the sample is harder than that usually used in similar previous studies. These AGNs are mainly complied from the RXTE All Sky Survey, and complemented by the released INTEGRAL AGN catalog. The black hole masses, bolometric luminosities of AGN, and Eddington ratios are derived from their optical spectra in terms of the broad Hβ emission line. The tight correlation between the hard X-ray (3-20 keV) and bolometric/line luminosity is well identified in our sample. Also identified is a strong inverse Baldwin relationship of the Hβ emission line. In addition, all of these hard X-ray AGNs are biased toward luminous objects with a high Eddington ratio (mostly between 0.01 and 0.1) and a low column density (<1022 cm-2), which is most likely due to the selection effect of the surveys. The hard X-ray luminosity is consequently found to be strongly correlated with the black hole mass. We believe the sample completeness will be improved in the next few years by the ongoing Swift and the International Gamma-Ray Astrophysics Laboratory missions, and by the next advanced missions, such as NuSTAR, Simbol-X, and NeXT. Finally, the correlation between RFe (= optical Fe II/Hβ) and disk temperature as assessed by T vprop (L/L Edd)M -1 BH leads us to suggest that the strength of the Fe II emission is mainly determined by the shape of the ionizing spectrum.

  7. Design and operational experience of a microwave cavity axion detector for the 20–100μeV range

    DOE PAGES

    Al Kenany, S.; Anil, M. A.; Backes, K. M.; ...

    2017-02-09

    We describe a dark matter axion detector designed, constructed, and operated both as an innovation platform for new cavity and amplifier technologies and as a data pathfinder in the 5-25 GHz range (~20-100 eV). The platform is small but flexible to facilitate the development of new microwave cavity and amplifier concepts in an operational environment. The experiment has recently completed its first data production; it is the first microwave cavity axion search to deploy a Josephson parametric amplifier and a dilution refrigerator to achieve near-quantum limited performance.

  8. 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.

  9. 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.

  10. OSSE observations of galactic 511 keV annihilation radiation

    NASA Technical Reports Server (NTRS)

    Purcell, W. R.; Grabelsky, D. A.; Johnson, W. N.; Jung, G. V.; Kinzer, R. L.; Kurfess, J. D.; Strickman, M. S.; Ulmer, M. P.

    1992-01-01

    The Oriented Scintillation Spectrometer Experiment (OSSE) on the Compton Gamma-Ray Observatory has performed several observations of the galactic plane and galactic center region to measure the distribution of galactic 511 keV positron annihilation radiation. Preliminary analysis of data collected during the observation of the galactic center region over the period 13-24 Jun. 1991, indicates the presence of a 511 keV line and positronium continuum superimposed on a power-law continuum. The line of flux was found to be (2.7 +/- 0.5) x 10(exp -4) gamma/sq cm sec, with a positronium fraction of (0.9 +/- 0.2). The 3(sigma) upper limit to daily variations in the 511 keV line flux from the mean during the observation interval is 3 x 10(exp -4) gamma/sq cm sec. If all of the observed annihilation radiation is assumed to originate from the x-ray source 1E 1740.7-2942, the corresponding 511 keV line flux would be (3.0 +/- 0.6) x 10(exp -4) gamma/sq cm sec. The 3(sigma) upper limit for 511 keV line emission from the x-ray binary GX1+4 is 6 x 10(exp -4) gamma/sq cm sec. Results from the galactic plane observations at galactic longitudes of 25 degrees (16-21 Aug. 1991) and 339 degrees (6-11 Sep. 1991) suggest that the emission is concentrated near the galactic center. The observations and the preliminary results are described.

  11. Development of multilayer laminar-type diffraction gratings to achieve high diffraction efficiencies in the 1-8 keV energy region

    NASA Astrophysics Data System (ADS)

    Ishino, Masahiko; Heimann, Philip A.; Sasai, Hiroyuki; Hatayama, Masatoshi; Takenaka, Hisataka; Sano, Kazuo; Gullikson, Eric M.; Koike, Masato

    2006-09-01

    W/C and Co/SiO2 multilayer gratings have been fabricated by depositing a multilayer coating on the surface of laminar-type holographic master gratings. The diffraction efficiency was measured by reflectometers in the energy region of 0.6-8.0 keV at synchrotron radiation facilities as well as with an x-ray diffractometer at 8.05 keV. The Co/SiO2 and W/C multilayer gratings showed peak diffraction efficiencies of 0.47 and 0.38 at 6.0 and 8.0 keV, respectively. To our knowledge, the peak efficiency of the W/C multilayer grating is the highest measured with hard x rays. The diffraction efficiency of the Co/SiO2 multilayer gratings was higher than that of the W/C multilayer grating in the energy range of 2.5-6.0 keV. However, it decreased significantly in the energy above the K absorption edge of Co (7.71 keV). For the Co/SiO2 multilayer grating, the measured diffraction efficiencies agreed with the calculated curves assuming a rms roughness of ˜1 nm.

  12. Search for 511 keV emission in satellite galaxies of the Milky Way with INTEGRAL/SPI

    NASA Astrophysics Data System (ADS)

    Siegert, Thomas; Diehl, Roland; Vincent, Aaron C.; Guglielmetti, Fabrizia; Krause, Martin G. H.; Boehm, Celine

    2016-10-01

    Context. The positron (e+) annihilation γ-ray signal in the Milky Way (MW) shows a puzzling morphology: a very bright bulge and a very low surface-brightness disk. A coherent explanation of the e+ origin, propagation through the Galaxy and subsequent annihilation in the interstellar medium has not yet been found. Tentative explanations involve e+s from radioactivity, X-ray binaries, and dark matter (DM). Aims: Dwarf satellite galaxies (DSGs) are believed to be dominated by DM and hence are promising candidates in the search for 511 keV emission as a result of DM annihilation into e+e--pairs. The goal of this study is to constrain possible 511 keV γ-ray signals from 39 DSGs of the MW and to test the annihilating DM scenario. Methods: We used the spectrometer SPI on INTEGRAL to extract individual spectra for the studied objects in the range 490-530 keV. As the diffuse galactic 511 keV emission dominates the overall signal, we modelled the large-scale morphology of the MW accordingly and included this in a maximum likelihood analysis. Alternatively, a distance-weighted stacked spectrum was determined, representing an average DSG seen in 511 keV. Results: Only Reticulum II (Ret II) shows a 3.1σ signal. Five other sources show tentative 2σ signals. The ratio of mass to 511 keV luminosity, Υ511, shows a marginal trend towards higher values for intrinsically brighter objects in contrast to the mass-to-light ratio, ΥV in the V band, which is generally used to uncover DM in DSGs. Conclusions: All derived 511 keV flux values or upper limits are above the flux level implied by a DM interpretation of the MW bulge signal. The signal detected from Ret II is unlikely to be related to a DM origin alone, otherwise, the MW bulge would be ~100 times brighter in 511 keV than what is seen with SPI. Ret II is exceptional considering the DSG sample and rather points to enhanced recent star formation activity if its origins are similar to processes in the MW. Understanding this

  13. 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.

  14. 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,…

  15. 2 CFR 176.20 - Agency responsibilities (general).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 2 Grants and Agreements 1 2014-01-01 2014-01-01 false Agency responsibilities (general). 176.20 Section 176.20 Grants and Agreements Office of Management and Budget Guidance for Grants and Agreements... enforcement or termination action in accordance with 2 CFR 215.62 or the agency's implementation of the...

  16. 2 CFR 176.20 - Agency responsibilities (general).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 2 Grants and Agreements 1 2012-01-01 2012-01-01 false Agency responsibilities (general). 176.20 Section 176.20 Grants and Agreements Office of Management and Budget Guidance for Grants and Agreements... enforcement or termination action in accordance with 2 CFR 215.62 or the agency's implementation of the...

  17. 2 CFR 176.20 - Agency responsibilities (general).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 2 Grants and Agreements 1 2013-01-01 2013-01-01 false Agency responsibilities (general). 176.20 Section 176.20 Grants and Agreements Office of Management and Budget Guidance for Grants and Agreements... enforcement or termination action in accordance with 2 CFR 215.62 or the agency's implementation of the...

  18. 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…

  19. 37 CFR 2.20 - Declarations in lieu of oaths.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Declarations in lieu of oaths. 2.20 Section 2.20 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE... therefrom, declares that all statements made of his/her own knowledge are true; and all statements made...

  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. 2 CFR 176.20 - Agency responsibilities (general).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 2 Grants and Agreements 1 2011-01-01 2011-01-01 false Agency responsibilities (general). 176.20 Section 176.20 Grants and Agreements Office of Management and Budget Guidance for Grants and Agreements... with 2 CFR 215.62 or the agency's implementation of the OMB Circular A-102 grants management...

  2. 2 CFR 176.20 - Agency responsibilities (general).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Agency responsibilities (general). 176.20 Section 176.20 Grants and Agreements OFFICE OF MANAGEMENT AND BUDGET GOVERNMENTWIDE GUIDANCE FOR GRANTS... appropriate enforcement or termination action in accordance with 2 CFR 215.62 or the agency's...

  3. 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,…

  4. 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…

  5. 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…

  6. The use of Web 2.0 technologies.

    PubMed

    Kohtz, Cindy; Gowda, Connie; Stockert, Patricia; White, Jane; Kennel, Lynn

    2012-01-01

    Although many publications laud the potential benefits of using Web 2.0 technologies in nursing education, little has been published on the extent of their use. This descriptive study examined the personal and academic use of Web 2.0 technologies among nursing students enrolled in 3 different baccalaureate programs.

  7. 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…

  8. 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…

  9. 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…

  10. 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…

  11. 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…

  12. 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.)

  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. 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...

  15. 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,…

  16. 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…

  17. Recommended Therapeutic INR Range for Patients with Antiphospholipid Syndrome on Warfarin Anticoagulation: Is Moderate-Intensity (INR 2.0 - 3.0) or High-Intensity (INR 3.1 - 4.0) Better for Reducing Risk of Recurrent Thromboembolic Events?

    PubMed Central

    Do, Tiffanie; Peacock, Katie; Takundwa, Prisca T

    2016-01-01

    Patients with antiphospholipid syndrome (APS) are at increased risk of recurrent thromboembolic events due to the pathology of the disease. While prolonged anticoagulation is the treatment of choice for patients with thrombosis, much debate remains about the optimum intensity of anticoagulation. Anticoagulation with warfarin has been shown to decrease rates of thrombosis recurrence, but definitive evidence regarding targeted therapy to an INR of moderate (2.0 - 3.0) or high (3.1 - 4.0) intensity is lacking.  PMID:27725921

  18. Simultaneous ejection of two molecular ions from keV gold atomic and polyatomic projectile impacts.

    PubMed

    Rickman, R D; Verkhoturov, S V; Parilis, E S; Schweikert, E A

    2004-01-30

    We present the first experimental data on the simultaneous ejection of two molecular ions from the impact of Au(+)(n) (1< or =n< or =4) with energies ranging between 17 and 56 keV. The yields from single phenylalanine (Ph) emission, coemission of two Ph ions, and emission of the Ph dimer were measured. Large increases (1 to 2 orders of magnitude) in coemitted ion yields were observed with increasing projectile energy and complexity. Correlation coefficients were calculated for the coemission of two Ph ions; their behavior suggests differences in emission pathways for bombardment by atomic and polyatomic projectiles.

  19. 47 CFR 20.2 - Other applicable rule parts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... § 20.2 Other applicable rule parts. Other FCC rule parts applicable to licensees in the commercial... filing electronically via the ULS. (b) Part 2. This part contains the Table of Frequency Allocations...

  20. 47 CFR 20.2 - Other applicable rule parts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... § 20.2 Other applicable rule parts. Other FCC rule parts applicable to licensees in the commercial... filing electronically via the ULS. (b) Part 2. This part contains the Table of Frequency Allocations...

  1. Biofuels Science and Facilities (Carbon Cycle 2.0)

    ScienceCinema

    Keasling, Jay D

    2016-07-12

    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/

  2. Carbon Cycle 2.0: Ashok Gadgil: global impact

    ScienceCinema

    Ashok Gadgi

    2016-07-12

    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/

  3. Energy Demand in China (Carbon Cycle 2.0)

    ScienceCinema

    Price, Lynn

    2016-07-12

    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/

  4. Measuring the 511 keV emission in the direction of 1E1740.7-2942 with BATSE

    NASA Technical Reports Server (NTRS)

    Wallyn, P.; Ling, J. C.; Mahoney, W. A.; Wheaton, W. A.; Durouchoux, P.; Corbel, S.; Astier-Perret, L.; Poirot, L.

    1997-01-01

    Observations of the 511 keV emission in the direction of 1E 1740.7-2942 (1E) using the earth burst and transient source experiment (BATSE) onboard the Compton Gamma Ray Observatory (CGRO), are presented. The CGRO phase 1 average spectrum of 1E is calculated using a method which assumes that a given source spectrum is the sum of the flux coming directly from the object and the contribution from the surrounding diffuse emission. The 1E light curve is calculated in the 40 to 150 keV range. It presents a constant flux excess of 70 mCrab in comparison with observations from the SIGMA gamma ray telescope onboard the GRANAT observatory. By removing this contribution, the 1E spectral transition from the low state to the high standard state observed by SIGMA is confirmed, and it is shown that the 511 keV flux is independent of the 1E long term evolution from low state to high standard state. It is concluded that the 511 keV emission of (4.2 +/- 1.3) x 140(exp -4) photons/sq cm s observed in the direction of 1E is mainly diffuse and spatially extended.

  5. 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

  6. 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…

  7. Usage Analysis of Web 2.0 and Library 2.0 Tools by Librarians in Kwara State Academic Libraries

    ERIC Educational Resources Information Center

    Tella, Adeyinka; Soluoku, Taofeeqat

    2016-01-01

    This study analysed the usage of Web 2.0 and Library 2.0 tools by librarians in Kwara State academic libraries. A sample of 40 librarians was surveyed through total enumeration sampling technique from four different tertiary education institutions libraries in Kwara State, Nigeria. Questionnaire was used for the collection of data. The collected…

  8. New heavy-fermion antiferromagnet UPd2Cd20.

    PubMed

    Hirose, Yusuke; Doto, Hiroshi; Honda, Fuminori; Li, Dexin; Aoki, Dai; Haga, Yoshinori; Settai, Rikio

    2016-10-26

    We succeeded in growing a new high quality single crystal of a ternary uranium compound UPd2Cd20. From the electrical resistivity, magnetization, magnetic susceptibility, and specific heat experiments, UPd2Cd20 is found to be an antiferromagnetic heavy-fermion compound with the Néel temperature [Formula: see text]  =  5 K and exhibits the large electronic specific heat coefficient γ exceeding 500 mJ (K(2)· mol)(-1). This compound is the first one that exhibits the magnetic ordering with the magnetic moments of the U atom in a series of UT2X20 (T: transition metal, X  =  Al, Zn, Cd). UPd2Cd20 shows typical characteristic features in heavy-fermion systems such as a broad maximum in the magnetic susceptibility at [Formula: see text] and a large coefficient A of T (2) term in the resistivity.

  9. UTM TCL 2.0 Software Version Description (SVD) Document

    NASA Technical Reports Server (NTRS)

    Mcguirk, Patrick

    2017-01-01

    This is the Unmanned Aircraft Systems (UAS) Traffic Management (UTM) Technical Capability Level(TCL) 2.0 Software Version Description (SVD) document. This UTM TCL 2.0 SVD describes the following four topics: 1. Software Release Contents: A listing of the files comprising this release 2. Installation Instructions: How to install the release and get it running 3. Changes Since Previous Release: General updates since the previous UTM release 4. Known Issues: Known issues and limitations in this release

  10. Search for a 17 keV neutrino in the internal bremsstrahlung spectrum of 125I

    NASA Astrophysics Data System (ADS)

    Hindi, M. M.; Kozub, R. L.; Robinson, S. J.

    1994-06-01

    We have searched for evidence of the emission of a 17 keV neutrino in the internal bremsstrahlung (IB) spectrum accompanying the electron capture decay of 125I. The IB spectrum, recorded in a planar Ge detector, has 1.2×106 counts per keV at 17 keV below the 2p end point. We set an upper limit of 0.4% for the admixture of a 17 keV neutrino, at the 90% confidence level, and exclude a 0.8% admixture at the 99.6% confidence level. The QEC value is found to be 185.77+/-0.06 keV. We also find that the recent calculations of Surić et al., which employ relativistic self-consistent-field atomic wave functions, reproduce the shape and relative intensity of IB partial spectra within a few percent.

  11. Monte Carlo study of correction factors for Spencer-Attix cavity theory at photon energies at or above 100 keV.

    PubMed

    Borg, J; Kawrakow, I; Rogers, D W; Seuntjens, J P

    2000-08-01

    To develop a primary standard for 192Ir sources, the basic science on which this standard is based, i.e., Spencer-Attix cavity theory, must be established. In the present study Monte Carlo techniques are used to investigate the accuracy of this cavity theory for photons in the energy range from 20 to 1300 keV, since it is usually not applied at energies below that of 137Cs. Ma and Nahum [Phys. Med. Biol. 36, 413-428 (1991)] found that in low-energy photon beams the contribution from electrons caused by photons interacting in the cavity is substantial. For the average energy of the 192Ir spectrum they found a departure from Bragg-Gray conditions of up to 3% caused by photon interactions in the cavity. When Monte Carlo is used to calculate the response of a graphite ion chamber to an encapsulated 192Ir source it is found that it differs by less than 0.3% from the value predicted by Spencer-Attix cavity theory. Based on these Monte Carlo calculations, for cavities in graphite it is concluded that the Spencer-Attix cavity theory with delta = 10 keV is applicable within 0.5% for photon energies at 300 keV or above despite the breakdown of the assumption that there is no interaction of photons within the cavity. This means that it is possible to use a graphite ion chamber and Spencer-Attix cavity theory to calibrate an 192Ir source. It is also found that the use of delta related to the mean chord length instead of delta = 10 keV improves the agreement with Spencer-Attix cavity theory at 60Co from 0.2% to within 0.1% of unity. This is at the level of accuracy of which the Monte Carlo code EGSnrc calculates ion chamber responses. In addition, it is shown that the effects of other materials, e.g., insulators and holders, have a substantial effect on the ion chamber response and should be included in the correction factors for a primary standard of air kerma.

  12. 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.

  13. 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.

  14. Incommensurate short-range multipolar order parameter of phase II in Ce3Pd20Si6

    NASA Astrophysics Data System (ADS)

    Portnichenko, P. Y.; Paschen, S.; Prokofiev, A.; Vojta, M.; Cameron, A. S.; Mignot, J.-M.; Ivanov, A.; Inosov, D. S.

    2016-12-01

    The clathrate compound Ce3Pd20Si6 is a heavy-fermion metal that exhibits magnetically hidden order at low temperatures. Reputedly, this exotic type of magnetic ground state, known as "phase II", could be associated with the ordering of Ce 4 f quadrupolar moments. In contrast to conventional (dipolar) order, it has vanishing Bragg intensity in zero magnetic field and, as a result, has escaped direct observation by neutron scattering until now. Here we report the observation of diffuse magnetic neutron scattering induced by an application of magnetic field along either the [1 1 ¯0 ] or the [001 ] direction within phase II. The broad elastic magnetic signal that surrounds the (111) structural Bragg peak can be attributed to a short-range G -type antiferromagnetic arrangement of field-induced dipoles modulated by the underlying multipolar order on the simple-cubic sublattice of Ce ions occupying the 8 c Wyckoff site. In addition, for magnetic fields applied along the [001 ] direction, the diffuse magnetic peaks in Ce3Pd20Si6 become incommensurate, suggesting a more complex modulated structure of the underlying multipolar order that can be continuously tuned by a magnetic field.

  15. 20. BUILDING I, BAYS 3, 2 AND 1, AND BUILDING ...

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

    20. BUILDING I, BAYS 3, 2 AND 1, AND BUILDING K, VIEW SOUTHEAST, NORTHWEST ELEVATIONS - Public Service Railway Company, Newton Avenue Car Shops, Bounded by Tenth, Mount Ephraim, Border & Newton Avenue, Camden, Camden County, NJ

  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. Photocopy of photograph #20 dated February 2, 1916, photographer Chas. ...

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

    Photocopy of photograph #20 dated February 2, 1916, photographer Chas. McCaul Co. Perspective view southwest of completed exterior of Stamford Post Office - Stamford Post Office, 421 Atlantic Street, Stamford, Fairfield County, CT

  18. 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

  19. 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.

  20. 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.

  1. SFA 2.0- Watershed Structure and Controls

    ScienceCinema

    Williams, Ken

    2016-07-12

    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.

  2. A New Observation of the Quiet Sun Soft X-ray (0.5-5 keV) Spectrum

    NASA Astrophysics Data System (ADS)

    Caspi, A.; Woods, T. N.; Stone, J.

    2012-12-01

    The solar corona is the brightest source of X-rays in the solar system, and the X-ray emission is highly variable with solar activity. While this is particularly true during solar flares, when emission can be enhanced by many orders of magnitude up to gamma-ray energies, even the so-called "quiet Sun" is bright in soft X-rays (SXRs), as the ~1-2 MK ambient plasma of the corona emits significant thermal bremsstrahlung up to ~5 keV. However, the actual solar SXR (0.5-5 keV) spectrum is not well known, particularly during quiet periods, as, with few exceptions, this energy range has not been systematically studied in many years. Previous observations include ultra-high-resolution but very narrow-band spectra from crystral spectrometers (e.g. Yohkoh/BCS), or integrated broadband irradiances from photometers (e.g. GOES/XRS, TIMED/XPS, etc.) that lack detailed spectral information. In recent years, broadband measurements with fair energy resolution (~0.5-0.7 keV FWHM) were made by SphinX on CORONAS-Photon and XRS on MESSENGER, although they did not extend below ~1 keV. We present observations of the quiet Sun SXR emission obtained using a new SXR spectrometer flown on the third SDO/EVE underflight calibration rocket (NASA 36.286). The commercial off-the-shelf Amptek X123 silicon drift detector, with an 8-micron Be window and custom aperture, measured the solar SXR emission from ~0.5 to >10 keV with ~0.15 keV FWHM resolution (though, due to hardware limitations, with only ~0.12 keV binning) and 2-sec cadence over ~5 minutes on 23 June 2012. Despite the rising solar cycle, activity on 23 June 2012 was abnormally low, with no visible active regions and GOES XRS emission near 2010 levels; we measured no solar counts above ~4 keV during the observation period. We compare our X123 measurements with spectra and broadband irradiances from other instruments, including the SphinX observations during the deep solar minimum of 2009, and with upper limits of >3 keV quiet Sun emission

  3. 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

  4. Happiness and the Family 2.0 Paradigm

    NASA Astrophysics Data System (ADS)

    Mocan, Rodica; Racorean, Stefana

    Does new media technology have the potential to make us happier? This paper explores the influence of new information communication technologies on family life satisfaction while analyzing some of the factors that determine changes in the way we live our lives in the information age. Family 2.0 is the new paradigm of family life and the emergence of Web 2.0 type of applications is at the very core of its existence.

  5. What Web 2.0 Means to Facilities Professionals

    ERIC Educational Resources Information Center

    Allen, Scott

    2008-01-01

    It's official--the Web is now social. Actually, it has always been social to a degree, but now it's "mostly" social. A lot of terms have been coined or adopted to describe various aspects of this phenomenon--social media, social networking, consumer-generated media (CGM) and Web 2.0. While it is hard to define "exactly" what Web 2.0 is, or when…

  6. Maskirovka 2.0: Hybrid Threat, Hybrid Response

    DTIC Science & Technology

    2015-12-01

    and psychological operations. Maskirovka 2.0 is a continuation of the old military approach, to which we must add new whole- of-government tools...Moscow. Each of these has aspirations to join Western structures , including the European Union and NATO. In fact, it was largely at U.S. insistence that...weaknesses as essential considerations of the Maskirovka 2.0 game plan. We need to take this into consideration as we design the structure of the

  7. Continuous Tamper-proof Logging using TPM2.0

    DTIC Science & Technology

    2014-06-16

    Continuous Tamper-proof Logging using TPM2.0 Paul England, Limin Jia, James Lorch, and Arunesh Sinha July 9, 2013 (Revised June 16...00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Continuous Tamper-proof Logging using TPM2.0 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM...unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Auditing system logs is an important means of ensuring systems’ security in situations where run-time

  8. SPHY v2.0: Spatial Processes in HYdrology

    NASA Astrophysics Data System (ADS)

    Terink, W.; Lutz, A. F.; Simons, G. W. H.; Immerzeel, W. W.; Droogers, P.

    2015-07-01

    This paper introduces and presents the Spatial Processes in HYdrology (SPHY) model (v2.0), its development background, its underlying concepts, and some example applications. SPHY has been developed with the explicit aim of simulating terrestrial hydrology on flexible scales, under various physiographical and hydroclimatic conditions, by integrating key components from existing and well-tested models. SPHY is a spatially distributed leaky bucket type of model, and is applied on a cell-by-cell basis. The model is written in the Python programming language using the PCRaster dynamic modeling framework. SPHY (i) integrates most hydrologic processes, (ii) has the flexibility to be applied in a wide range of hydrologic applications, and (iii) on various scales, and (iv) can easily be implemented. The most relevant hydrological processes that are integrated into the SPHY model are rainfall-runoff processes, cryosphere processes, evapotranspiration processes, the dynamic evolution of vegetation cover, lake/reservoir outflow, and the simulation of root-zone moisture contents. Studies in which the SPHY model was successfully applied and tested are described in this paper, including (i) real-time soil moisture predictions to support irrigation management in lowland areas, (ii) climate change impact studies in snow- and glacier-fed river basins, and (iii) operational flow forecasting in mountainous catchments.

  9. SPHY v2.0: Spatial Processes in HYdrology

    NASA Astrophysics Data System (ADS)

    Terink, W.; Lutz, A. F.; Simons, G. W. H.; Immerzeel, W. W.; Droogers, P.

    2015-02-01

    This paper introduces and presents the Spatial Processes in HYdrology (SPHY) model (v2.0), its development background, its underlying concepts, and some typical applications. The SPHY model is developed using the best components of existing and well-tested simulation models, and is developed with the explicit aim to simulate terrestrial hydrology at flexible scales, under various land use and climate conditions. SPHY is a spatially distributed leaky bucket type of model, and is applied on a cell-by-cell basis. The model is written in the Python programming language using the PCRaster dynamic modelling framework. Compared to other hydrological models, that typically focus on the simulation of streamflow only, the SPHY model has several advantages: it (i) integrates most relevant hydrological processes, (ii) is setup modular, (iii) is easy adjustable and applicable, (iii) can easily be linked to remote sensing data, and (iv) can be applied for operational as well as strategic decision support. The most relevant hydrological processes that are integrated in the SPHY model are rainfall-runoff processes, cryosphere processes, evapotranspiration processes, the simulation of dynamic vegetational cover, lake/reservoir outflow, and the simulation of rootzone moisture contents. Studies in which the SPHY model was successfully applied and tested are described in this paper, and range from (i) real-time soil moisture predictions to support irrigation management in lowland areas, to (ii) detailed climate change impact studies in snow and glacier-fed river basins, to (iii) operational flow forecasting in mountainous catchments.

  10. On-line range prediction system, part 2

    NASA Technical Reports Server (NTRS)

    Levan, Nhan

    1988-01-01

    The on-line range prediction system is designed for providing a prediction of the target range in the case of a laser data dropout. It consists of real time implementation of a Kalman filter on an IBM PC/AT equipped with necessary hardware. The system was set up and tested at Crows Landing in the Fall of 1987. The improvements made on the on-line range prediction system during 1988 are examined. Solutions are proposed and discussed to the several problems encountered during system tests. Then, the improvements made on the filter software are explained, namely, accounting for the time lag and providing data continously. Finally, the ideas are mentioned that can be considered in the future.

  11. The LAGRANTO Lagrangian analysis tool - version 2.0

    NASA Astrophysics Data System (ADS)

    Sprenger, M.; Wernli, H.

    2015-08-01

    Lagrangian trajectories are widely used in the atmospheric sciences, for instance to identify flow structures in extratropical cyclones (e.g., warm conveyor belts) and long-range transport pathways of moisture and trace substances. Here a new version of the Lagrangian analysis tool LAGRANTO (Wernli and Davies, 1997) is introduced, which offers considerably enhanced functionalities. Trajectory starting positions can be defined easily and flexibly based on different geometrical and/or meteorological conditions, e.g., equidistantly spaced within a prescribed region and on a stack of pressure (or isentropic) levels. After the computation of the trajectories, a versatile selection of trajectories is offered based on single or combined criteria. These criteria are passed to LAGRANTO with a simple command language (e.g., "GT:PV:2" readily translates into a selection of all trajectories with potential vorticity, PV, greater than 2 PVU; 1 PVU = 10-6 K m2 kg-1 s-1). Full versions of this new version of LAGRANTO are available for global ECMWF and regional COSMO data, and core functionality is provided for the regional WRF and MetUM models and the global 20th Century Reanalysis data set. The paper first presents the intuitive application of LAGRANTO for the identification of a warm conveyor belt in the North Atlantic. A further case study then shows how LAGRANTO can be used to quasi-operationally diagnose stratosphere-troposphere exchange events. Whereas these examples rely on the ECMWF version, the COSMO version and input fields with 7 km horizontal resolution serve to resolve the rather complex flow structure associated with orographic blocking due to the Alps, as shown in a third example. A final example illustrates the tool's application in source-receptor analysis studies. The new distribution of LAGRANTO is publicly available and includes auxiliary tools, e.g., to visualize trajectories. A detailed user guide describes all LAGRANTO capabilities.

  12. 20 CFR 210.2 - Definition of service.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Definition of service. 210.2 Section 210.2... RAILROAD SERVICE § 210.2 Definition of service. Service means a period of time for which an employee... an employee for creditable military service as defined in part 212 of this chapter. Service...

  13. 20 CFR 335.2 - Manner of claiming sickness benefits.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false Manner of claiming sickness benefits. 335.2 Section 335.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD UNEMPLOYMENT INSURANCE ACT SICKNESS BENEFITS § 335.2 Manner of claiming sickness benefits. (a) Forms required...

  14. 20 CFR 349.2 - Conditions for reopening.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Conditions for reopening. 349.2 Section 349.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD UNEMPLOYMENT INSURANCE ACT FINALITY OF DECISIONS REGARDING UNEMPLOYMENT AND SICKNESS INSURANCE BENEFITS § 349.2 Conditions...

  15. 20 CFR 335.2 - Manner of claiming sickness benefits.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Manner of claiming sickness benefits. 335.2 Section 335.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD UNEMPLOYMENT INSURANCE ACT SICKNESS BENEFITS § 335.2 Manner of claiming sickness benefits. (a) Forms required...

  16. 20 CFR 349.2 - Conditions for reopening.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false Conditions for reopening. 349.2 Section 349.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD UNEMPLOYMENT INSURANCE ACT FINALITY OF DECISIONS REGARDING UNEMPLOYMENT AND SICKNESS INSURANCE BENEFITS § 349.2 Conditions...

  17. 20 CFR 349.2 - Conditions for reopening.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Conditions for reopening. 349.2 Section 349.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD UNEMPLOYMENT INSURANCE ACT FINALITY OF DECISIONS REGARDING UNEMPLOYMENT AND SICKNESS INSURANCE BENEFITS § 349.2 Conditions...

  18. 20 CFR 349.2 - Conditions for reopening.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Conditions for reopening. 349.2 Section 349.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD UNEMPLOYMENT INSURANCE ACT FINALITY OF DECISIONS REGARDING UNEMPLOYMENT AND SICKNESS INSURANCE BENEFITS § 349.2 Conditions...

  19. 20 CFR 349.2 - Conditions for reopening.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 1 2014-04-01 2012-04-01 true Conditions for reopening. 349.2 Section 349.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD UNEMPLOYMENT INSURANCE ACT FINALITY OF DECISIONS REGARDING UNEMPLOYMENT AND SICKNESS INSURANCE BENEFITS § 349.2 Conditions...

  20. 20 CFR 335.2 - Manner of claiming sickness benefits.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Manner of claiming sickness benefits. 335.2 Section 335.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD UNEMPLOYMENT INSURANCE ACT SICKNESS BENEFITS § 335.2 Manner of claiming sickness benefits. (a) Forms required...

  1. 20 CFR 335.2 - Manner of claiming sickness benefits.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 1 2014-04-01 2012-04-01 true Manner of claiming sickness benefits. 335.2 Section 335.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD UNEMPLOYMENT INSURANCE ACT SICKNESS BENEFITS § 335.2 Manner of claiming sickness benefits. (a) Forms required...

  2. 20 CFR 212.2 - Military service defined.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Military service defined. 212.2 Section 212.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT MILITARY SERVICE § 212.2 Military service defined. Military service is the performance of active service by an...

  3. 20 CFR 221.2 - Railroad Retirement Board jurisdiction.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 1 2014-04-01 2012-04-01 true Railroad Retirement Board jurisdiction. 221.2 Section 221.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT JURISDICTION DETERMINATIONS § 221.2 Railroad Retirement Board jurisdiction. (a) Life cases. The Board...

  4. 20 CFR 221.2 - Railroad Retirement Board jurisdiction.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Railroad Retirement Board jurisdiction. 221.2 Section 221.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT JURISDICTION DETERMINATIONS § 221.2 Railroad Retirement Board jurisdiction. (a) Life cases. The Board...

  5. 20 CFR 221.2 - Railroad Retirement Board jurisdiction.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false Railroad Retirement Board jurisdiction. 221.2 Section 221.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT JURISDICTION DETERMINATIONS § 221.2 Railroad Retirement Board jurisdiction. (a) Life cases. The Board...

  6. 20 CFR 330.2 - Computation of daily benefit rate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Computation of daily benefit rate. 330.2 Section 330.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD UNEMPLOYMENT INSURANCE ACT DETERMINATION OF DAILY BENEFIT RATES § 330.2 Computation of daily benefit rate. (a)...

  7. 20 CFR 655.2 - Territory of Guam.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Territory of Guam. 655.2 Section 655.2... Territory of Guam, and the Department of Labor (Department or DOL) does not certify to the USCIS of DHS the... provisions of the H-2B visa program provisions in the Territory of Guam. Pursuant to DHS regulations, 8...

  8. 20 CFR 221.2 - Railroad Retirement Board jurisdiction.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Railroad Retirement Board jurisdiction. 221.2 Section 221.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT JURISDICTION DETERMINATIONS § 221.2 Railroad Retirement Board jurisdiction. (a) Life cases. The Board...

  9. 20 CFR 221.2 - Railroad Retirement Board jurisdiction.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Railroad Retirement Board jurisdiction. 221.2 Section 221.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT JURISDICTION DETERMINATIONS § 221.2 Railroad Retirement Board jurisdiction. (a) Life cases. The Board...

  10. 20 CFR 632.2 - Scope and purpose.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Scope and purpose. 632.2 Section 632.2 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR INDIAN AND NATIVE AMERICAN EMPLOYMENT AND TRAINING PROGRAMS Introduction § 632.2 Scope and purpose. It is the purpose of Native...

  11. 20 CFR 632.2 - Scope and purpose.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 3 2012-04-01 2012-04-01 false Scope and purpose. 632.2 Section 632.2 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR INDIAN AND NATIVE AMERICAN EMPLOYMENT AND TRAINING PROGRAMS Introduction § 632.2 Scope and purpose. It is the purpose of Native...

  12. 20 CFR 212.2 - Military service defined.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 1 2014-04-01 2012-04-01 true Military service defined. 212.2 Section 212.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT MILITARY SERVICE § 212.2 Military service defined. Military service is the performance of active service by an...

  13. 20 CFR 212.2 - Military service defined.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Military service defined. 212.2 Section 212.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT MILITARY SERVICE § 212.2 Military service defined. Military service is the performance of active service by an...

  14. 20 CFR 212.2 - Military service defined.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Military service defined. 212.2 Section 212.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT MILITARY SERVICE § 212.2 Military service defined. Military service is the performance of active service by an...

  15. 20 CFR 212.2 - Military service defined.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false Military service defined. 212.2 Section 212.2 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT MILITARY SERVICE § 212.2 Military service defined. Military service is the performance of active service by an...

  16. 20 CFR 640.2 - Federal law requirements.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 3 2012-04-01 2012-04-01 false Federal law requirements. 640.2 Section 640.2... PROMPTNESS-UNEMPLOYMENT COMPENSATION § 640.2 Federal law requirements. (a) Conformity. Section 303(a)(1) of the Social Security Act, 42 U.S.C. 503(a)(1), requires that a State law include provision for:...

  17. 20 CFR 650.2 - Federal law requirements.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Federal law requirements. 650.2 Section 650.2... PROMPTNESS-UNEMPLOYMENT COMPENSATION § 650.2 Federal law requirements. (a) Section 303(a)(1) of the Social Security Act requires that a State law include provision for: Such methods of administration * * * as...

  18. 20 CFR 650.2 - Federal law requirements.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 3 2012-04-01 2012-04-01 false Federal law requirements. 650.2 Section 650.2... PROMPTNESS-UNEMPLOYMENT COMPENSATION § 650.2 Federal law requirements. (a) Section 303(a)(1) of the Social Security Act requires that a State law include provision for: Such methods of administration * * * as...

  19. 20 CFR 640.2 - Federal law requirements.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Federal law requirements. 640.2 Section 640.2... PROMPTNESS-UNEMPLOYMENT COMPENSATION § 640.2 Federal law requirements. (a) Conformity. Section 303(a)(1) of the Social Security Act, 42 U.S.C. 503(a)(1), requires that a State law include provision for:...

  20. 20 CFR 609.2 - Definitions of terms.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 3 2012-04-01 2012-04-01 false Definitions of terms. 609.2 Section 609.2 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR UNEMPLOYMENT COMPENSATION FOR FEDERAL CIVILIAN EMPLOYEES General Provisions § 609.2 Definitions of terms. For the purposes of the Act and this part: (a) Act means...