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1

Efficiency calibrations of cylindrically bent transmission crystals in the 20 to 80 keV x-ray energy range.  

PubMed

Two quartz (10-11) crystals were cylindrically bent to a 25.4 cm radius of curvature and were mounted in identical Cauchois-type transmission spectrometers, and the crystal diffraction efficiencies were measured to 5% absolute accuracy using narrow bandwidth x-ray source fluences in the 20 to 80 keV energy range. The measured integrated reflectivity values were compared to calculations performed using a computational model that accounts for the diffraction geometry of the bent transmission crystal. These crystal calibrations enable the accurate measurement of absolute hard x-ray emission levels from laser-produced plasmas and other laboratory sources. PMID:21499348

Szabo, Csilla I; Feldman, Uri; Seltzer, Stephen; Hudson, Lawrence T; O'Brien, Michelle; Park, Hye-Sook; Seely, John F

2011-04-15

2

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

SciTech Connect

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.

Wang, Linghua [Department of Geophysics, Peking University, 100871 Beijing (China); Lin, Robert P.; Salem, Chadi; Pulupa, Marc; Larson, Davin E.; Luhmann, Janet G. [Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450 (United States); Yoon, Peter H., E-mail: wanglhwang@gmail.com [School of Space Research, Kyung Hee University, Yongin, Gyeonggi (Korea, Republic of)

2012-07-01

3

The Extragalactic X-ray Background in the 0.2 - 2 keV Range  

NASA Technical Reports Server (NTRS)

We made the first measurement of the extragalactic 0.7 keV background. We detected the X-ray shadow of a neutral gas cloud in the Magellanic Bridge. We further constrained the point-like source contribution based on the mean spectrum of detected sources and on our early autocorrelation function analysis of the background. We find that our measurement extragalactic background intensity is significantly greater than the total point-like source contribution expected if sources are responsible for all the observed background intensity in the 1-2 keV range. For a further confirmation of the theoretical prediction of the hot intergalactic medium, we have conducted a pilot project to search for enhanced X-ray-emitting features near rich clusters of galaxies. We have reported the discovery of an elongated complex of extended X-ray-emitting objects in and around the galaxy cluster A2125, based on an archival deep ROSAT/PSPC observation. Using multicolor optical imaging of galaxies in the field, we find that this complex represents a hierarchical superstructure spanning approx. 11 Mpc at the redshift approx. 0.247. The multiple peak X-ray morphology and large blue galaxy fraction of A2125 indicate that the cluster is undergoing a coalescence of subunits. The superstructure contains two additional clusters, projected at distances of only 3 and 4.3 Mpc from A2125. The most interesting feature is, however, the low-surface-brightness X-ray emission from a moderate galaxy concentration away from individual clusters. The emission likely arises in a hot (approx. 10(exp 7) K) intergalactic medium, as predicted in N-body/hydro simulations of structure formation. These results demonstrate the potential of X-ray observations as a powerful tool to study the large-scale structure of the universe.

Wang, Q. Daniel

1997-01-01

4

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)

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.

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

2013-04-01

5

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

SciTech Connect

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

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

2006-06-14

6

Experimental study of ionization yield of liquid xenon for electron recoils in the energy range 2.8 - 80 keV  

E-print Network

We present the results of the first experimental study of ionization yield of electron recoils with energies below 100 keV produced in liquid xenon by the isotopes: 37Ar, 83mKr, 241Am, 129Xe, 131Xe. It is confirmed by a direct measurement with 37Ar isotope (2.82 keV) that the ionization yield is growing up with the energy decrease in the energy range below ~ 10 keV accordingly to the NEST predictions. Decay time of scintillation at 2.82 keV is measured to be 25 +/- 3 ns at the electric field of 3.75 kV/cm.

D. Yu. Akimov; V. V. Afanasyev; I. S. Alexandrov; V. A. Belov; A. I. Bolozdynya; A. A. Burenkov; Yu. V. Efremenko; D. A. Egorov; A. V. Etenko; M. A. Gulin; S. V. Ivakhin; V. A. Kaplin; A. K. Karelin; A. V. Khromov; M. A. Kirsanov; S. G. Klimanov; A. S. Kobyakin; A. M. Konovalov; A. G. Kovalenko; A. V. Kuchenkov; A. V. Kumpan; Yu. A. Melikyan; R. I. Nikolaev; D. G. Rudik; V. V. Sosnovtsev; V. N. Stekhanov

2014-08-08

7

Experimental study of ionization yield of liquid xenon for electron recoils in the energy range 2.8–80 keV  

NASA Astrophysics Data System (ADS)

We present the results of the first detailed experimental study of ionization yield of electron recoils with energies below 100 keV produced in liquid xenon by the isotopes 37Ar, 83mKr, 241Am, 129Xe, 131Xe. It is confirmed by a direct measurement with 37Ar isotope (2.82 keV) that the ionization yield increases with the energy decrease in the energy range below ~ 10 keV in accord with the NEST predictions. Decay time of scintillation at 2.82 keV is measured to be ? = 25 ± 3 ns at electric field 3.75 kV/cm.

Akimov, D. Yu.; Afanasyev, V. V.; Alexandrov, I. S.; Belov, V. A.; Bolozdynya, A. I.; Burenkov, A. A.; Efremenko, Yu. V.; Egorov, D. A.; Etenko, A. V.; Gulin, M. A.; Ivakhin, S. V.; Kaplin, V. A.; Karelin, A. K.; Khromov, A. V.; Kirsanov, M. A.; Klimanov, S. G.; Kobyakin, A. S.; Konovalov, A. M.; Kovalenko, A. G.; Kuchenkov, A. V.; Kumpan, A. V.; Melikyan, Yu. A.; Nikolaev, R. I.; Rudik, D. G.; Sosnovtsev, V. V.; Stekhanov, V. N.

2014-11-01

8

Experimental study of ionization yield of liquid xenon for electron recoils in the energy range 2.8 - 80 keV  

E-print Network

We present the results of the first experimental study of ionization yield of electron recoils with energies below 100 keV produced in liquid xenon by the isotopes: 37Ar, 83mKr, 241Am, 129Xe, 131Xe. It is confirmed by a direct measurement with 37Ar isotope (2.82 keV) that the ionization yield is growing up with the energy decrease in the energy range below ~ 10 keV accordingly to the NEST predictions. Decay time of scintillation at 2.82 keV is measured to be 25 +/- 3 ns at the electric field of 3.75 kV/cm.

Akimov, D Yu; Alexandrov, I S; Belov, V A; Bolozdynya, A I; Burenkov, A A; Efremenko, Yu V; Egorov, D A; Etenko, A V; Gulin, M A; Ivakhin, S V; Kaplin, V A; Karelin, A K; Khromov, A V; Kirsanov, M A; Klimanov, S G; Kobyakin, A S; Konovalov, A M; Kovalenko, A G; Kuchenkov, A V; Kumpan, A V; Melikyan, Yu A; Nikolaev, R I; Rudik, D G; Sosnovtsev, V V; Stekhanov, V N

2014-01-01

9

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

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.

Derrien, H

2005-12-05

10

Chain-oxygen ordering in twin-free YBa2Cu3O7-single crystals driven by 20-keV electron irradiation  

E-print Network

Chain-oxygen ordering in twin-free YBa2Cu3O7- single crystals driven by 20-keV electron irradiation 2005 We have examined the effects of 20-keV electron irradiation on the -Cu 1 -O 1 - n chain-oxygen arrange- ments in oxygen-deficient but otherwise twin-free YBa2Cu3O7- single crystals. Comparison

Johansen, Tom Henning

11

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

SciTech Connect

When used for the production of an x-ray imaging backlighter source on Sandia National Laboratories' recently upgraded 26 MA Z Accelerator, the terawatt-class, multikilojoule, 526.57 nm Z-Beamlet laser (ZBL) [P. K. Rambo et al., Appl. Opt. 44, 2421 (2005)], in conjunction with the 6.151 keV (1s{sup 2}-1s2p triplet line of He-like Mn) curved-crystal imager [D. B. Sinars et al., Rev. Sci. Instrum. 75, 3672 (2004); G. R. Bennett et al., Rev. Sci. Instrum. 77, 10E322 (2006)], is capable of providing a high quality x radiograph per Z shot for inertial confinement fusion (ICF), complex hydrodynamics, and other high-energy-density physics experiments. For example, this diagnostic has recently afforded microgram-scale mass perturbation measurements on an imploding ignition-scale 1 mg ICF capsule [G. R. Bennett et al., Phys. Rev. Lett. 99, 205003 (2007)], where the perturbation was initiated by a surrogate deuterium-tritium (DT) fuel fill tube. Using an angle-time multiplexing technique, ZBL now has the capability to provide two spatially and temporally separated foci in the Z chamber, allowing 'two-frame' imaging to be performed, with an interframe time range of 2-20 ns. This multiplexing technique allows the full area of the four-pass amplifiers to be used for the two pulses, rather than split the amplifiers effectively into two rectangular sections, with one leg delayed with respect to the other, which would otherwise double the power imposed onto the various optics thereby halving the damage threshold, for the same irradiance on target. The 6.151 keV two frame technique has recently been used to image imploding wire arrays, using a 7.3 ns interframe time. The diagnostic will soon be converted to operate with p-rather than s-polarized laser light for enhanced laser absorption in the Mn foil, plus other changes (e.g., operation at the possibly brighter 6.181 keV Mn 1s{sup 2}-1s2p singlet line), to increase x-ray yields. Also, a highly sensitive inline multiframe ultrafast (1 ns gate time) digital x-ray camera is being developed [G. R. Bennett et al., Rev. Sci. Instrum. 77, 10E322 (2006)] to extend the system to 'four-frame' and markedly improve the signal-to-noise ratio. [At present, time-integrating Fuji BAS-TR2025 image plate (scanned with a Fuji BAS-5000 device) forms the time-integrated image-plane detector.].

Bennett, G. R.; Smith, I. C.; Shores, J. E.; Sinars, D. B.; Robertson, G.; Atherton, B. W.; Jones, M. C.; Porter, J. L. [Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185-1193 (United States)

2008-10-15

12

The development of a super-stable datum point for monitoring the energy scale of electron spectrometers in the energy range up to 20 keV  

Microsoft Academic Search

The long-term energy stability of the 7.5 keV and 17.8 keV conversion electrons of the 9.4 keV and 32 keV neutral transitions\\u000a respectively in 83mKr, emitted by solid 83Rb\\/83mKr sources, prepared by evaporation in a vacuum, is investigated using two different spectrometers. The results obtained indicate\\u000a the principal applicability of these 83Rb sources for monitoring the stability of the energy

D. Vénos; M. Zbo?il; J. Kašpar; O. Dragoun; J. Bonn; A. Kovalík; O. Lebeda; N. A. Lebedev; M. Ryšavý; K. Schlösser; A. Špalek; Ch. Weinheimer

2010-01-01

13

Extremely Small Proximity Effect in 30 keV Electron Beam Drawing with Thin Calixarene Resist for 20×20 nm2 Pitch Dot Arrays  

NASA Astrophysics Data System (ADS)

We studied proximity effect in 30 keV electron beam (EB) drawing with calixarene resist for patterned media and quantum devices. Using about 15-nm-thick calixarene resist on Si substrate in conventional EB drawing system, the proximity effect has been studied by forming and observing 20-, 25-, 30-, and 40-nm-pitch resist dot arrays and measuring exposure dosage intensity distribution (EID) function. As a result, the proximity effect is negligible small due to comparing with some dot sizes in center, side and corner of 2 µm square with 25×25 nm2 pitch dot arrays. In addition, the proximity effect parameter ? in EID function is less than 0.3. It is clear that the EB drawing and calixarene resist system is very suitable for forming ultrahigh packed dot arrays pattern. We demonstrated 20×20 nm2 pitch resist dot arrays (about 1.6 Tb/in.2) with a dot diameter of about 14 nm and the same size as everywhere in the pattern.

Hosaka, Sumio; Mohamad, Zulfakri; Shira, Masumi; Sano, Hirotaka; Yin, You; Miyachi, Akihira; Sone, Hayato

2008-02-01

14

The emission of Cygnus X-1: observations with INTEGRAL SPI from 20 keV to 2 MeV  

E-print Network

We report on Cyg X-1 observations performed by the SPI telescope onboard the INTEGRAL mission and distributed over more than 6 years. We investigate the variability of the intensity and spectral shape of this peculiar source in the hard X-rays domain, and more particularly up to the MeV region. We first study the total averaged spectrum which presents the best signal to noise ratio (4 Ms of data). Then, we refine our results by building mean spectra by periods and gathering those of similar hardness. Several spectral shapes are observed with important changes in the curvature between 20 and 200 keV, even at the same luminosity level. In all cases, the emission decreases sharply above 700 keV, with flux values above 1 MeV (or upper limits) well below the recently reported polarised flux (Laurent et al. 2011), while compatible with the MeV emission detected some years ago by CGRO/COMPTEL (McConnell et al., 2002). Finally, we take advantage of the spectroscopic capability of the instrument to seek for spectral f...

Jourdain, Elisabeth; Malzac, Julien

2011-01-01

15

Hard x-ray spectra from laser-generated plasmas recorded by the HENEX spectrometer in the 1 keV40 keV energy range  

Microsoft Academic Search

Hard x-ray spectra were recorded by the High Energy Electronic X-Ray (HENEX) spectrometer from a variety of targets irradiated by the Omega laser at the Laboratory for Laser Energetics. The HENEX spectrometer utilizes four reflection crystals covering the 1 keV to 20 keV energy range and one quartz(10-11) transmission crystal (Laue geometry) covering the 11 keV to 40 keV range.

J. F. Seely; C. A. Back; C. Constantin; R. W. Lee; H.-K. Chung; L. T. Hudson; C. I. Szabo; A. Henins; G. E. Holland; R. Atkin

2005-01-01

16

Excimer Emission using 20keV Electron Beam Excitation  

NASA Astrophysics Data System (ADS)

A small, continuously emitting rare gas excimer light source has been developed. The gas is excited by a 20keV dc-electron beam. A 300nm thick, 1×1mm^2 SiNx foil sustaining a pressure difference up to 2bar, separates the target volume from the high vacuum part of the electron gun. Spectra of the rare gases Ar, Kr, and Xe have been studied. The monochromator detector system was intensity calibrated in the wavelength range from 115nm to 320nm. Electron beam currents of typically 1?A were used for excitation. When used as a VUV lamp on the second excimer continua, energy conversion efficiencies of 30% were obtained. Emissions originating from the so called left turning points have been clearly observed at 155, 173, and 222nm in Ar_2^*, Kr_2^*, and Xe_2^*, respectively. The so called third continua between 185nm and 240nm (Ar), 220nm and 250nm (Kr), and at 270nm (Xe) have been studied. A new continuum in Xe at 280nm was found. (Funded by the A.v.Humboldt Foundation and NSF (CTS 94-19440). The authors acknowledge support by H. Huggins, A. Liddle and W.L. Brown (Bell Laboratories, Lucent Technologies))

Wieser, J.; Ulrich, A.; Murnick, D. E.

1996-10-01

17

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

NASA Astrophysics Data System (ADS)

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.

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

2005-07-01

18

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

Microsoft Academic Search

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 &etal;, Appl. Opt. 44, 2421 (2005)], in conjunction with the 6.151 keV (1s2-1s2p triplet line of He-like Mn) curved-crystal imager [D. B. Sinars &etal;, Rev. Sci. Instrum. 75,

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

2008-01-01

19

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

Microsoft Academic Search

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 (1s2-1s2p triplet line of He-like Mn) curved-crystal imager [D. B. Sinars et al., Rev. Sci.

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

2008-01-01

20

Energy dependence of photon-induced K? and K? x-ray production cross-sections for some elements with 38?Z?51 in the energy range 20-50 keV  

NASA Astrophysics Data System (ADS)

The energy dependence of photon-induced K? and K? x-ray production (or x-ray fluorescence) cross-sections for Sr, Y, Mo, Ru, Pd, Ag, In and Sb elements has been studied in the energy range of 20-50 keV using Energy Dispersive X-Ray Fluorescence (EDXRF) Spectrometry. The photon energy dependence of K x-ray production cross-sections was measured with secondary excitation method. A radioisotope point source of 241Am was employed to excite the K x-rays of secondary exciter elements. The L x-ray yields from Th and U were measured to determine IoG (the intensity of exciter K x-rays falling on primary target). The measurements have been made by observing the x-ray emissions with the help of HPGe detector coupled with a multichannel analyzer. The areas of the K? and K? spectral peaks, as well as the net peak areas, have been determined by a fitting process. The measured K? and K? x-ray production cross-sections have been compared with calculated theoretical values in this energy regime. The present experimental results for all the elements were in general agreement with the theoretical values calculated using photoionization cross-sections, fractional rates (based on Hartree-Slater potentials) and fluorescence yields.

Seven, Sabriye

2012-05-01

21

PRMI Temperature Scale in the Range from 4,2 K to 20 K  

Microsoft Academic Search

In 1964 the authors published preliminary results of their work on establishing the practical temperature scale in the temperature range from 4.2 K to 20 K. The temperature scale for this range was defined using a germanium resistance thermometer, as its sensitivity and reproducibility of readings are as good as it is required for the most accurate determinations of temperature.

D N Astrov; M P Orlova; G A Kytin

1969-01-01

22

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

PubMed Central

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

2014-01-01

23

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

NASA Astrophysics Data System (ADS)

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

Valalaki, Katerina; Nassiopoulou, Androula Galiouna

2014-06-01

24

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

SciTech Connect

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.

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

1997-11-01

25

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

NASA Astrophysics Data System (ADS)

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

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

26

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

NASA Technical Reports Server (NTRS)

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.

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

2002-01-01

27

Photon Counting Detectors for the 1.0 - 2.0 Micron Wavelength Range  

NASA Technical Reports Server (NTRS)

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.

Krainak, Michael A.

2004-01-01

28

High-resolution spectra of 20-300 keV hard X-rays from electron precipitation over Antarctica  

SciTech Connect

In December 1990, a set of liquid-nitrogen-cooled germanium hard X-ray and gamma-ray spectrometers was flown aboard a high-altitude balloon from McMurdo, Antarctica, for solar, astrophysical, and terrestrial observations. This flight was the first circumnavigation ({approximately}9-day duration) of the Antarctic continent by a large (800,000-cubic-meter) balloon. Bremsstrahlung hard X-ray emission extending up to {approximately}300 keV, from the precipitation of high-energy electrons, was observed on six separate occasions over the auroral zone, all during low geomagnetic activity (K{sub p}{le} 2+). All events were consistent with emission at the trapping boundary; observation over the polar cap showed no precipitation. The authors present the first high-resolution ({Delta}E {approximately}2 keV) full width at half maximum (FWHM) spectra of this hard X-ray emission in the energy range 20-300 keV. The observed count spectra are deconvolved by model-independent techniques to photon spectra and then to the precipitating electron spectra. The spectral hardness shows all inverse relation with L as expected. This result suggests that high-resolution spectroscopy could be extremely effective in characterizing electron precipitation if coupled with imaging capability. 26 refs., 9 figs., 1 tab.

Smith, D.M. [Univ. of Maryland, College Park, MD (United States)] [Univ. of Maryland, College Park, MD (United States); Lin, R.P. [Univ. of California, Berkeley, CA (United States)] [Univ. of California, Berkeley, CA (United States); Hurley, A.K. [Univ. of California, Berkeley, CA (United States)] [and others] [Univ. of California, Berkeley, CA (United States); and others

1995-10-01

29

Crossed molecular beams study of inelastic non-adiabatic processes in gas phase collisions between sodium ions and ZnBr2 molecules in the 0.10-3.50 keV energy range.  

PubMed

Inelastic electronically non-adiabatic reactions between Na(+) ions and neutral ZnBr(2) molecules, both in their electronic ground state, have been studied using crossed beams techniques and measuring the decaying emission radiation of the excited species produced. The fluorescent emission corresponding to Na(3 (2)P) produced by a charge transfer reaction was observed, as well as that corresponding to the decay of Zn(4s 5s (3)S), generated by dissociation of the neutral target molecule, to Zn(4s 4p (3)P). The phosphorescent decaying emission of Zn*(4s 4p (3)P) to the zinc ground state was also observed. For each emission process, the cross section energy dependences have been measured in the 0.10-3.50 keV energy range in the laboratory system. The ground electronic state of the (NaZnBr(2))(+) collision system has been characterized by ab initio chemical structure calculations at the second order Möller-Plesset perturbation level of theory using pseudo-potentials. By performing restricted open shell Hartree-Fock calculations for C(2v) geometries, four singlet and four triplet potential energy surfaces of the system have been calculated and used to interpret qualitatively the observed reactions. A simple two-state dynamical model is presented that allows an estimation of the maximum values for measured cross sections at high collision energies to be made. PMID:23083158

de Andrés, J; Lucas, J M; Albertí, M; Bofill, J M; Belyaev, A; Aguilar, A

2012-10-21

30

Crossed molecular beams study of inelastic non-adiabatic processes in gas phase collisions between sodium ions and ZnBr2 molecules in the 0.10-3.50 keV energy range  

NASA Astrophysics Data System (ADS)

Inelastic electronically non-adiabatic reactions between Na+ ions and neutral ZnBr2 molecules, both in their electronic ground state, have been studied using crossed beams techniques and measuring the decaying emission radiation of the excited species produced. The fluorescent emission corresponding to Na(3 2P) produced by a charge transfer reaction was observed, as well as that corresponding to the decay of Zn(4s 5s 3S), generated by dissociation of the neutral target molecule, to Zn(4s 4p 3P). The phosphorescent decaying emission of Zn*(4s 4p 3P) to the zinc ground state was also observed. For each emission process, the cross section energy dependences have been measured in the 0.10-3.50 keV energy range in the laboratory system. The ground electronic state of the (NaZnBr2)+ collision system has been characterized by ab initio chemical structure calculations at the second order Möller-Plesset perturbation level of theory using pseudo-potentials. By performing restricted open shell Hartree-Fock calculations for C2v geometries, four singlet and four triplet potential energy surfaces of the system have been calculated and used to interpret qualitatively the observed reactions. A simple two-state dynamical model is presented that allows an estimation of the maximum values for measured cross sections at high collision energies to be made.

de Andrés, J.; Lucas, J. M.; Albertí, M.; Bofill, J. M.; Belyaev, A.; Aguilar, A.

2012-10-01

31

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

SciTech Connect

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

Rae, Nicholas A.; Chantler, Christopher T.; Barnea, Zwi; Jonge, Martin D. de; Tran, Chanh Q.; Hester, James R. [School of Physics, University of Melbourne, Victoria 3010 (Australia); Australian Synchrotron, Victoria 3168 (Australia); La Trobe University, Victoria 3086 (Australia); Australian Nuclear Science and Technology Organisation, New South Wales 2234 (Australia)

2010-02-15

32

Range profiles of 600-1200 keV Xe(+) implanted in KTiOPO4  

NASA Astrophysics Data System (ADS)

600-1200 keV Xe(+) were implanted into KTiOPO4 (potassium titany phosphate) in increments of 100 keV. The depth distributions of implanted Xe(+) in KTiOPO4 were measured by Rutherford backscattering. The effects of chanelling, temperature, and dose on the depth distribution were briefly investigated. All range distributions were nearly Gaussian. The mean projected range and range straggling obtained were compared with the TRIM'91 code, projected range algorithm (PRAL) and Wang and Shi's (WS) calculation procedure based on Biersack's angular diffusion model. The results show that TRIM's 91 systematically underestimates the projected range by approximately 25%, PRAL underestimates the range by approximately 28%, and WS underestimates the range by approximately 7%. All calculate the underestimated range straggling by approximately a factor of two.

Wang, Ke-Ming; Ding, Pei-Jun; Wang, Wei; Lanford, W. A.; Shi, Bo-Rong; Yu, Zheng-Gang; Lu, Qing-Ming

1994-08-01

33

Transmission crystal x-ray spectrometer covering the 6 keV-18 keV energy range with E??E = 1800 instrumental resolving power.  

PubMed

A high-resolution x-ray spectrometer utilizing a thin quartz transmission crystal and covering the 6 keV-18 keV energy range has been developed and tested. The spectrometer consists of a cylindrically bent crystal in a vacuum housing. The crystal position and the range of Bragg angles that are incident on the crystal can be adjusted to record an ?4 keV wide spectrum in the 6 keV-18 keV range. The spectrometer is of the Cauchois type and has a compact linear geometry that is convenient for deployment at laser-produced plasma, EBIT, and other x-ray sources. Test spectra of the W L and Mo K lines from laboratory sources have linewidths as small as 11 eV, approaching the natural widths, and instrumental resolving power as high as 1800. Techniques for enhancing the energy resolution are experimentally demonstrated. PMID:23126934

Seely, John; Feldman, Uri; Brown, Charles; Pereira, Nino; Hudson, Lawrence; Glover, Jack; Silver, Eric

2012-10-01

34

Modeling the Chandra High Energy Transmission Gratings below 2 keV  

E-print Network

Modeling the Chandra High Energy Transmission Gratings below 2 keV K.A. Flanagana, T.H. Markerta, J The High Energy Transmission Grating Spectrometer of the Chandra X-Ray Observatory is a high spectral it below 2 keV to complete the coverage over the Chandra energy range. We investigate the carbon, nitrogen

35

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

SciTech Connect

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

Mio, A. M.; D'Arrigo, G.; Rimini, E.; Spinella, C. [IMM-CNR, Strada VIII 5, Zona Industriale, I-95121 Catania (Italy); Milazzo, R. G. [IMM-CNR, Strada VIII 5, Zona Industriale, I-95121 Catania (Italy); Dipartimento di Fisica e Astronomia, Universita di Catania, Via S. Sofia 64, I-95123 Catania (Italy); Peto, L.; Nadzeyka, A.; Bauerdick, S. [Raith GmbH, Konrad-Adenauer-Allee 8, 44263 Dortmund (Germany)

2013-01-28

36

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

PubMed

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. PMID:24519325

Tan, Zhenyu; Liu, Wei

2014-05-01

37

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

NASA Technical Reports Server (NTRS)

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.

Hardin, Jay C.; Pope, D. Stuart

1989-01-01

38

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

PubMed

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. PMID:24144616

Tan, Zhenyu; Liu, Wei

2013-12-01

39

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

NASA Astrophysics Data System (ADS)

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

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

2014-10-01

40

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

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.

Friedman, P.G.

1986-11-25

41

Formation of dot arrays with a pitch of 20 nm × 20 nm for patterned media using 30 keV EB drawing on thin calixarene resist  

NASA Astrophysics Data System (ADS)

We studied the possibility of achieving very fine-pitch dot arrays with a pitch of 20 nm × 20 nm using 30 keV electron beam (EB) drawing on negative calixarene resist. In order to form such patterns, we studied the dependence on resist thickness of the dot size and the packing. We propose EB drawing on an extremely thin film for very highly packed dot-array formation. Our experimental results demonstrate the possibility of forming highly packed dot-array patterns with a pitch of 20 nm × 20 nm and a resist thickness of about 13 nm, which corresponds to about 1.6 Tbits in-2.

Mohamad, Zulfakri bin; Shirai, Masumi; Sone, Hayato; Hosaka, Sumio; Kodera, Masatoshi

2008-01-01

42

SMM observation of a cosmic gamma-ray burst from 20 keV to 100 MeV  

NASA Technical Reports Server (NTRS)

The Solar Maximum Mission gamma-ray spectrometer has detected an intense gamma-ray burst that occurred on August 5, 1984. The burst originated from a source in the constellation Hydra and lasted about 45 s. Its integral fluence at 20 keV was 0.003 erg/sq cm. Spectral evolution similar to other bursts detected by SMM was observed. The overall shape of the spectrum from 20 keV to 100 MeV, on timescales as short as 2 s, is relatively constant. This shape can be fitted by the sum of an exponential-type function and a power law. There is no evidence for narrow or broadened emission lines.

Share, G. H.; Matz, S. M.; Messina, D. C.; Nolan, P. L.; Chupp, E. L.

1986-01-01

43

Study of avalanche photodiodes for soft X-ray detection below 20 keV  

NASA Astrophysics Data System (ADS)

The performance of the large area reach-through avalanche photodiode (APD), manufactured by Hamamatsu Photonics, K.K. as a high resolution X-ray detector is presented. The mentioned APD has an area of 3 mm ?, a fast time response for signal carrier collection and its thick depletion layer of 130 ?m shows a potential to be used as an effective X-ray absorber below 20 keV. Having a capacitance of ˜10 pF and a low dark current of 5 nA for a gain of 15, at room temperature, this APD had demonstrated one of the best energy resolutions within this kind of devices: 6.4% (FWHM) for 5.9 keV photons with a minimum detectable energy of 0.3 keV, measured at -20C. The experiments for the timing property were made in a synchrotron beam facility using an 8 keV X-ray beam; the reached count rate was above 108 counts/s, corresponding to a very short dead time of 4.5 ns/pulse. In order to test the radiation hardness of the APD, the device was irradiated at a Ring Cyclotron Facility with a 53.5 MeV proton beam. The total dose was of 11.3 krad and no fatal damage was found in the APD, although the dark current of the APD had shown an increase of one order of magnitude. Finally, the obtained results allow us to affirm that the reach-through APD has the potential to become an excellent X-ray detector, especially in the space mission application.

Yatsu, Y.; Kuramoto, Y.; Kataoka, J.; Kotoku, J.; Saito, T.; Ikagawa, T.; Sato, R.; Kawai, N.; Kishimoto, S.; Mori, K.; Kamae, T.; Ishikawa, Y.; Kawabata, N.

2006-08-01

44

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

SciTech Connect

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 ? ? ?{sup *} electronic transitions of the bases followed by electron transfer to the C–O ?{sup *} bond in the phosphate group. Occupancy of the ?{sup *} orbital ruptures the C–O bond of the backbone via dissociative electron attachment, producing a SSB. From a comparison of our results with those of other works, including theoretical calculations and electron-energy-loss spectra of the bases, the 4.6 eV peak in the SSB yield function is attributed to the resonance decay into the lowest electronically excited states of the bases; in particular, those resulting from the transitions 1{sup 3}A{sup ?} (?{sub 2} ? ?{sub 3}{sup *}) and 1{sup 3}A{sup ?} (n{sub 2} ? ?{sub 3}{sup *}) of thymine and 1{sup 3}A{sup ?} (? ? ?{sup *}) of cytosine. The strongest peak at 9.6 eV in the SSB yield function is also associated with electron captured by excited states of the bases, resulting mostly from a multitude of higher-energy ? ? ?{sup *} transitions. The DSB yield function exhibits strong maxima at 6.1 and 9.6 eV. The peak at 9.6 eV is probably related to the same resonance manifold as that leading to SSB, but the other at 6.1 eV may be more restricted to decay into the electronic state 1{sup 3}A{sup ?} (? ? ?{sup *}) of cytosine via autoionization. The yield function of crosslinks is dominated by a broad peak extending over the 3.6-11.6 eV range with a sharper one at 17.6 eV. The different line shape of the latter function, compared to that of SSB and DSB, appears to be due to the formation of reactive radical sites in the initial supercoiled configuration of the plasmid, which react with the circular form (i.e., DNA with a SSB) to produce a crosslink.

Luo, Xinglan; Zheng, Yi, E-mail: Yizheng@fzu.edu.cn [Research Institute of Photocatalysis, State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University, Fuzhou 350002 (China)] [Research Institute of Photocatalysis, State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University, Fuzhou 350002 (China); Sanche, Léon [Group in the Radiation Sciences, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4 (Canada)] [Group in the Radiation Sciences, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, Quebec J1H 5N4 (Canada)

2014-04-21

45

100 keV electron backscattered range and coefficient for silicon.  

SciTech Connect

The authors have measured the range and intensity of backscattered electrons in silicon from a 100 keV source using a process independent method. Backscattered electrons contributed to the total dose of features written in a negative tone electron beam resist. Instead of measuring the height of the resist and using a contrast curve to convert the resist height to dose, the heights of the features were made equal by adjusting the backscattered contribution through dose assignments. Creating features of equal height eliminated the need to use a contrast curve to convert from resist height to total dose. Also, it allowed for measurements of the backscattered contribution from larger distances. Using a circularly symmetric torus pattern, the three-dimensional backscatter problem was reduced to a 1-dimensional Gaussian form. The authors measured the range of the backscattered electrons, {beta}, to be 31.08 {+-} 0.06 {micro}m. By varying the writing dose of the pattern, we determined the backscatter coefficient, {eta}, to be 0.63 {+-} 0.03.

Czaplewski, D.A.; Ocola, L.E. (Center for Nanoscale Materials)

2012-01-01

46

Stopping powers and extrapolated ranges for electrons (1-10 keV) in metals  

Microsoft Academic Search

A thin film quasiadiabatic calorimeter has been applied to the measurement of the stopping power for electrons, under conditions of small angle scattering, in Al, Ni, Cu, Ag and Au in the energy region 1 keV to 10 keV. Results are presented with an estimated precision of 15%. Corrections are included for the multiple scattering enhancement of the apparent path

K O Al-Ahmad; D E Watt

1983-01-01

47

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

SciTech Connect

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.

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

1984-10-03

48

Contrasting physics in wire array z pinch sources of 1-20 keV emission on the Z facilitya)  

NASA Astrophysics Data System (ADS)

Imploding wire arrays on the 20 MA Z generator have recently provided some of the most powerful and energetic laboratory sources of multi-keV photons, including ˜375 kJ of Al K-shell emission (h? ˜ 1-2 keV), ˜80 kJ of stainless steel K-shell emission (h? ˜ 5-9 keV) and a kJ-level of Mo K-shell emission (h? ˜ 17 keV). While the global implosion dynamics of these different wire arrays are very similar, the physical process that dominates the emission from these x-ray sources fall into three broad categories. Al wire arrays produce a column of plasma with densities up to ˜3 × 1021 ions/cm3, where opacity inhibits the escape of K-shell photons. Significant structure from instabilities can reduce the density and increase the surface area, therefore increase the K-shell emission. In contrast, stainless steel wire arrays operate in a regime where achieving a high pinch temperature (achieved by thermalizing a high implosion kinetic energy) is critical and, while opacity is present, it has less impact on the pinch emissivity. At higher photon energies, line emission associated with inner shell ionization due to energetic electrons becomes important.

Ampleford, D. J.; Jones, B.; Jennings, C. A.; Hansen, S. B.; Cuneo, M. E.; Harvey-Thompson, A. J.; Rochau, G. A.; Coverdale, C. A.; Laspe, A. R.; Flanagan, T. M.; Moore, N. W.; Sinars, D. B.; Lamppa, D. C.; Harding, E. C.; Thornhill, J. W.; Giuliani, J. L.; Chong, Y.-K.; Apruzese, J. P.; Velikovich, A. L.; Dasgupta, A.; Ouart, N.; Sygar, W. A.; Savage, M. E.; Moore, J. K.; Focia, R.; Wagoner, T. C.; Killebrew, K. L.; Edens, A. D.; Dunham, G. S.; Jones, M. C.; Lake, P. W.; Nielsen, D. S.; Wu, M.; Carlson, A. L.; Kernahan, M. D.; Ball, C. R.; Scharberg, R. D.; Mulville, T. D.; Breden, E. W.; Speas, C. S.; Olivas, G.; Sullivan, M. A.; York, A. J.; Justus, D. W.; Cisneros, J. C.; Strizic, T.; Reneker, J.; Cleveland, M.; Vigil, M. P.; Robertson, G.; Sandoval, D.; Cox, C.; Maurer, A. J.; Graham, D. A.; Huynh, N. B.; Toledo, S.; Molina, L. P.; Lopez, M. R.; Long, F. W.; McKee, G. R.; Porter, J. L.; Herrmann, M. C.

2014-05-01

49

Contrasting physics in wire array z pinch sources of 1-20?keV emission on the Z facility  

SciTech Connect

Imploding wire arrays on the 20 MA Z generator have recently provided some of the most powerful and energetic laboratory sources of multi-keV photons, including ?375?kJ of Al K-shell emission (h????1–2?keV), ?80?kJ of stainless steel K-shell emission (h????5–9?keV) and a kJ-level of Mo K-shell emission (h????17?keV). While the global implosion dynamics of these different wire arrays are very similar, the physical process that dominates the emission from these x-ray sources fall into three broad categories. Al wire arrays produce a column of plasma with densities up to ?3?×?10{sup 21} ions/cm{sup 3}, where opacity inhibits the escape of K-shell photons. Significant structure from instabilities can reduce the density and increase the surface area, therefore increase the K-shell emission. In contrast, stainless steel wire arrays operate in a regime where achieving a high pinch temperature (achieved by thermalizing a high implosion kinetic energy) is critical and, while opacity is present, it has less impact on the pinch emissivity. At higher photon energies, line emission associated with inner shell ionization due to energetic electrons becomes important.

Ampleford, D. J., E-mail: damplef@sandia.gov; Jones, B.; Jennings, C. A.; Hansen, S. B.; Cuneo, M. E.; Harvey-Thompson, A. J.; Rochau, G. A.; Coverdale, C. A.; Laspe, A. R.; Flanagan, T. M.; Moore, N. W.; Sinars, D. B.; Lamppa, D. C.; Harding, E. C.; Sygar, W. A.; Savage, M. E.; Moore, J. K.; Focia, R.; Wagoner, T. C.; Killebrew, K. L. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); and others

2014-05-15

50

Inelastic processes in K+-He collisions in energy range 0.7-10 keV  

NASA Astrophysics Data System (ADS)

Absolute cross sections for charge exchange, ionization, stripping, and excitation in K+-He collisions were measured in the ion energy range 0.7-10 keV. The experimental data and the schematic correlation diagrams are used to analyze and determine the mechanisms for these processes. The increase of the excitation probability of inelastic channels with the angle of scattering is revealed. An exceptionally highly excited state of He is observed and a peculiarity for the excitation function of the resonance line is explained. The intensity ratio for the excitation of the K II ?=60.1 nm and ?=61.2 nm lines is 5:1, which indicates the high probability for excitation of the singlet resonance level 1P1 compared to the triplet level 3P1. The similarity of the population of the 4p state of the potassium ion and atom as well as the anomalously small values of the excitation cross sections are explained.

Lomsadze, R. A.; Gochitashvili, M. R.; Kezerashvili, R. Ya.; Mosulishvili, N. O.; Phaneuf, R.

2013-04-01

51

Performance of LAPEX and its spectroscopic capabilities in the 20--300 keV energy band to observe SN1987a  

SciTech Connect

Recent observations of SN1987a both in the 1--10 keV and in the 10--350 keV energy range detected X-ray emission from the source with a very hard spectrum, a power law with ..cap alpha..approx.1.4, and a flux of approx.10 mCrab at 30 keV. We describe the performances of the LAPEX experiment for observation of SN1987a. In the 20--300 keV operative energy band of LAPEX, the following goals can be achieved: detection of emission lines due to Co/sup 57/ (122 keV) and Ti/sup 44/ (67.9 and 78.4 keV), elements that could be produced in the supernova explosion; measurement of the comptonized spectrum from the expanding ejecta; investigation on possible coherent pulsations due to a newly born pulsar down to timescales of approx.0.1 ms. In the following, a thorough description of the payload and of its performances will be given.

Frontera, F.; Basili, A.; Dal Fiume, D.; Franceschini, T.; Landini, G.; Morelli, E.; Pamini, M.; Poulsen, J.M.; SIlvestri, S.; Costa, E.; and others

1988-09-25

52

Isotopic Mo Neutron Total Cross Section Measurements in the Energy Range 1 to 620 keV  

NASA Astrophysics Data System (ADS)

A series of new total cross section measurements for the stable molybdenum isotopes of 92,94,95,96,98,100Mo covering the energy range between 1 keV and 620 keV was performed at the Gaerttner LINAC Center at Rensselaer Polytechnic Institute. New high-accuracy resonance parameters were extracted from an analysis of the data using the multilevel R-matrix Bayesian code SAMMY. In the unresolved resonance region, average resonance parameters and fits to the total cross sections were obtained using the Bayesian Hauser-Feshbach statistical model code FITACS.

Bahran, R.; Barry, D.; Leinweber, G.; Rapp, M.; Block, R.; Daskalakis, A.; McDermott, B.; Piela, S.; Blain, E.; Danon, Y.

2014-05-01

53

A Study of Longitudinal and Transversal Range Parameters of Ion-Implanted 40 360 keV Molybdenum in Silicon  

NASA Astrophysics Data System (ADS)

This paper presents an experimental and theoretical study of longitudinal and transversal range parameters of molybdenum ions ranging from 40 to 360 keV implanted in silicon. In the experimental part of this study, silicon wafers were tilted by 7° and 55° at the time they were implanted with molybdenum ions. The implanted-ion depth profiles were detected by means of secondary ionmass specfroscopy (SIMS) measurements. The measured range parameters were extracted from fitting the measured implanted-ion depth profiles to a Pearson distribution. In addition, the transversal range straggling measurements were obtained by using the Furukawa and Matsumura formula. Measured range parameters were also compared to the values calculated from the Biersack theory. It was found that the calculated values of projected range, longitudinal range straggling, skewness, kurtosis, and transversal range straggling agreed to the corresponding measured values within (on average) 9%, 7%, 32%, 17%, and 10%, respectively.

Liang, J.

1999-01-01

54

Imaging detectors for 20–100 keV x-ray backlighters in high-energy-density experimental science petawatt experiments  

Microsoft Academic Search

We are developing a petawatt laser for use as a high-energy backlighter source in the 20–100 keV range on the National Ignition Facility (NIF). High-energy x-ray backlighters will be essential for radiographing high-energy-density experimental science (HEDES) targets, especially to probe implosions and high areal density planar samples. For these high energy backlighter imaging experiments, we are developing two types of

J. E. Wickersham; H.-S. Park; P. M. Bell; J. A. Koch; O. L. Landen; J. D. Moody

2004-01-01

55

Imaging detectors for 20-100 keV x-ray backlighters in high-energy-density experimental science petawatt experiments  

Microsoft Academic Search

We are developing a petawatt laser for use as a high-energy backlighter source in the 20-100 keV range on the National Ignition Facility (NIF). High-energy x-ray backlighters will be essential for radiographing high-energy-density experimental science (HEDES) targets, especially to probe implosions and high areal density planar samples. For these high energy backlighter imaging experiments, we are developing two types of

J. E. Wickersham; H.-S. Park; P. M. Bell; J. A. Koch; O. L. Landen; J. D. Moody

2004-01-01

56

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

SciTech Connect

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.

Agueda, N.; Sanahuja, B. [Departament d'Astronomia i Meteorologia, Institut de Ciencies del Cosmos, Universitat de Barcelona, Barcelona (Spain); Vainio, R. [Department of Physics, University of Helsinki, Helsinki (Finland)

2012-10-15

57

Parameterization of X-ray mass attenuation coefficients in the energy range of 1-150 keV  

Microsoft Academic Search

Knowledge of X-ray mass attenuation coefficients is necessary when the thick target PIXE method is applied for quantitative elemental analysis of materials. For this purpose, the X-ray mass attenuation coefficients of Veigele [Atom. Data Tables 5 (1973) 51] ave been parameterized in the photon energy range of 1-150 keV for all elements from hydrogen to plutonium (Z = 1-94), taking

J. Braziewicz; E. Braziewicz; M. Pajek

1993-01-01

58

The prediction of thick target electron bremsstrahlung spectra in the 0.25–50 keV energy range  

Microsoft Academic Search

The importance of electron bremsstrahlung has continuously grown since its early discovery more than one century ago, increasingly being involved in different scientific areas. The present work deals with the prediction of thick-target bremsstrahlung spectrum in the frame of scanning electron microprobe analysis. X-ray energies considered range from 0.25 to 50 keV, whereas the models discussed involve electron incident energies up to

Jorge Trincavelli; Gustavo Castellano

2008-01-01

59

FHBS calculation of ionized electron angular and energy distribution following the p+H collision at 20 keV  

E-print Network

A Finite Hilbert Basis Set (FHBS) method to calculate the angular and energy distribution of ejected electrons in an ion-atom collision is presented. This method has been applied to the p + H collision at 20 keV impact energy. An interference effect...

Fu, Jun

2004-11-15

60

Measurements and assessment of 12C(d,p?)13C reaction cross sections in the deuteron energy range 740-2000 keV for analytical applications  

NASA Astrophysics Data System (ADS)

The total cross sections of the 12C(d,p?1)13C (E? = 3089 keV), 12C(d,p?2)13C (E? = 3684 keV) and 12C(d,p?3)13C (E? = 3854 keV) reactions, as well as differential cross sections for (d,po), (d,p1) reactions and (d,d0) elastic scattering were determined in the 740-2000 keV deuteron energy range using a self-supporting natural carbon foil and detecting the gamma-rays and particles simultaneously. In order to test the validity of the measured gamma-ray producing cross sections, benchmark experiments were performed using kapton foils with two different thicknesses. Both the obtained gamma- and particle production cross section results were compared with data existing in literature, and in the case of (d,po) the experimental differential cross section data were compared also with the theoretical evaluated values.

Csedreki, L.; Uzonyi, I.; Szíki, G. Á.; Szikszai, Z.; Gyürky, Gy.; Kiss, Á. Z.

2014-06-01

61

Experimental evidence for Young's interference effects in autoionization following 30 keV He2++H2 collision  

NASA Astrophysics Data System (ADS)

The emission of electrons from autoionizing He** outgoing projectiles formed in a double capture 30 keV He2+ +H2 collision has been analysed at detection angles ranging from 90° up to 162°. The autoionization cross section differential in the angle is found to oscillate. This result is attributed to a Young interference mechanism produced by the postcollisional interaction of the emitted electron with the two-centre exploding H+ + H+ residual target.

J-Ychesnel; Hajaji, A.; Barrachina, R. O.; Frémont, F.

2007-03-01

62

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

NASA Technical Reports Server (NTRS)

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.

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

63

Airborne 2 color ranging experiment  

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

64

EMISSION LINES BETWEEN 1 AND 2 keV IN COMETARY X-RAY SPECTRA  

SciTech Connect

We present the detection of new cometary X-ray emission lines in the 1.0-2.0 keV range using a sample of comets observed with the Chandra X-Ray Observatory and ACIS spectrometer. We have selected five comets from the Chandra sample with good signal-to-noise spectra. The surveyed comets are C/1999 S4 (LINEAR), C/1999 T1 (McNaught-Hartley), 153P/2002 (Ikeya-Zhang), 2P/2003 (Encke), and C/2008 8P (Tuttle). We modeled the spectra with an extended version of our solar wind charge exchange (SWCX) emission model. Above 1 keV, we find Ikeya-Zhang to have strong emission lines at 1340 and 1850 eV which we identify as being created by SWCX lines of Mg XI and Si XIII, respectively, and weaker emission lines at 1470, 1600, and 1950 eV formed by SWCX of Mg XII, Mg XI, and Si XIV, respectively. The Mg XI and XII and Si XIII and XIV lines are detected at a significant level for the other comets in our sample (LS4, MH, Encke, 8P), and these lines promise additional diagnostics to be included in SWCX models. The silicon lines in the 1700-2000 eV range are detected for all comets, but with the rising background and decreasing cometary emission, we caution that these detections need further confirmation with higher resolution instruments.

Ewing, Ian; Christian, Damian J. [Department of Physics and Astronomy, California State University, 18111 Nordhoff Street, Northridge, CA 91330 (United States)] [Department of Physics and Astronomy, California State University, 18111 Nordhoff Street, Northridge, CA 91330 (United States); Bodewits, Dennis [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States)] [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Dennerl, Konrad [Max-Planck-Institut fuer extraterrestrische Physik, Postfach 1312, D-85741 Garching Germany (Germany)] [Max-Planck-Institut fuer extraterrestrische Physik, Postfach 1312, D-85741 Garching Germany (Germany); Lisse, Carey M. [Planetary Exploration Group, Space Department, Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd, Laurel, MD 20723 (United States)] [Planetary Exploration Group, Space Department, Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd, Laurel, MD 20723 (United States); Wolk, Scott J., E-mail: ian.ewing.794@my.csun.edu, E-mail: daman.christian@csun.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2013-01-20

65

Mechanisms of O2 Sputtering from Water Ice by keV Ions  

NASA Technical Reports Server (NTRS)

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.

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

2005-01-01

66

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

SciTech Connect

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

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

2007-01-01

67

The gyromagnetic ratio of the 589 keV 3\\/2 ? state of 117 In  

Microsoft Academic Search

Theg-factor of the 589 keV state of117In has been determined by a measurement of the rotation of the 1,303–273 keV? —? directional correlation in an external magnetic field of 9.55(1) T. The result,g3\\/2(589 keV)=+0.068(39), contradicts the usual interpretation of the state as the 2p3\\/2 single proton hole configuration for which the Schmidt value isg3\\/2-(Schmidt)=+2.53. It favours the interpretation as the

A. Alzner; E. Bodenstedt; B. Gemünden; H. Reif

1985-01-01

68

Maskless nano-implant of 20 keV Ga+ in bulk Si(1 0 0) substrates  

NASA Astrophysics Data System (ADS)

Multidirectional SPEG (Solid Phase Epitaxial Growth) of silicon has been investigated in micro and nanoamorphous structures generated on a crystalline substrate by a nano-sized ion beam, Gaussian shaped and with a standard deviation of about 5 nm. The 20 keV Ga+ ions were implanted at a fluence of 5 × 1014 ions cm-2 in a bulk Si(1 0 0) single crystal. Two structures were used for the implants: circular regions of 100 nm and 1 ?m diameters respectively and straight lines 10 nm in width and few microns in length along (1 0 0) or (1 1 0) directions. The lateral spread of ions has been taken into account in the damage estimation. Transmission Electron Microscopy indicates that the structures are made of an amorphous core surrounded by a defective and filamentary shell. The recovery of the damaged outer regions promptly occurs during the early stages of the thermal treatment at 500-600 °C for all the structures. By prolonging annealing time, re-crystallization of the amorphous cores is achieved too by the movement of the underneath crystal-amorphous interface. The re-growth is almost defects free when the contribution of the crystalline seed below the structures is present, defective and twin mediated if it misses as in the thinnest regions of the specimen.

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

2014-12-01

69

Creation of 2-5 keV and 5-10 keV sky maps using XMM-Newton data  

NASA Astrophysics Data System (ADS)

Sky maps are powerful visualisation tools for quicklook analysis of extended sources. The latest sky map in soft X-rays (0.1-2.4 keV) has been created in the 1990's using ROSAT data. By analysing publically available data from XMM-Newton X-ray mission we constructed new sky maps in two energy bands - 2-5 keV and 5-10 keV, complementary to ROSAT data, covering approximately 1% of the sky, and included them in our web-based tool http://skyview.virgoua.org.

Savchenko, D. O.; Iakubovskyi, D. A.

2014-12-01

70

Measurement of the F19(p,?)Ne20 reaction and interference terms from Ec.m.=200-760 keV  

NASA Astrophysics Data System (ADS)

The F19(p,?)Ne20 reaction represents the only breakout path for the carbon-nitrogen-oxygen cycle operating at temperatures below T=0.1 GK, an energy regime important for main-sequence hydrogen burning as well as hydrogen burning in asymptotic giant branch stars. Large experimental uncertainties exist due to unknown low energy direct and resonant reaction contributions that have been difficult to study because of the high ?-ray background from the F19(p,?2?) reaction. A new detection technique has been developed at the University of Notre Dame to measure the F19(p,?) and F19(p,?i?) reactions over an energy range of Ec.m.=200-760 keV. The analysis was carried out in a Breit-Wigner framework. This allowed a new determination of the resonance parameters as well as a first measurement of the signs of the interference terms. Partial widths and resonance strengths are reported for the resonances in this region.

Couture, A.; Beard, M.; Couder, M.; Görres, J.; Lamm, L.; Leblanc, P. J.; Lee, H. Y.; O'Brien, S.; Palumbo, A.; Stech, E.; Strandberg, E.; Tan, W.; Uberseder, E.; Ugalde, C.; Wiescher, M.; Azuma, R.

2008-01-01

71

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

PubMed

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. PMID:23192280

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

2012-12-21

72

Investigation of carbon buildup in simulations of multi-impact bombardment of Si with 20 keV C60 projectiles.  

PubMed

Beams of single C(+) ions are used for the incorporation of Si in the synthesis of thin films of SiC, which have a wide range of technological applications. We present a theoretical investigation of the use of C60 cluster beams to produce thin films of SiC on a Si substrate, which demonstrates that there are potential advantages to using C60(+) cluster ion beams over C(+) single ion beams. Molecular dynamics simulations of the multi-impact bombardment of Si with 20 keV normal incident C60 projectiles are performed to study the buildup of carbon and the formation of a region of Si-C mixing up to a fluence of 1.6 impacts/nm(2) (900 impacts). The active region of the Si solid is defined as the portion of target that contains almost all of the C atoms and the height ranges from 3 nm to more than 7 nm below the average surface height. The C fraction in the active region is calculated as a function of fluence, and a simple model is developed to describe the dependence of the C fraction on fluence. An analytic function from this model is fit to the data from the molecular dynamics simulations and extrapolated to predict the fluence necessary to achieve equilibrium conditions in which the C fraction is constant with fluence. The fraction of C atoms at equilibrium is predicted to be 0.19, and the fluence necessary to achieve 90% of this asymptotic maximum value is equal to 4.0 impacts/nm(2). PMID:24527764

Krantzman, Kristin D; Briner, Clarissa A; Garrison, Barbara J

2014-09-18

73

Mu-2 ranging  

NASA Technical Reports Server (NTRS)

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

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

1977-01-01

74

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

PubMed

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

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

2001-06-01

75

Accurate Monte Carlo calculations of the combined attenuation and build-up factors, for energies (20-1500 keV) and distances (0-10 cm) relevant in brachytherapy.  

PubMed

The combined build-up and attenuation factor, B exp (-mu r), of point isotropic photon sources in a water medium has been calculated using the Monte Carlo method, for energies (20-1500 keV) and distances (1-10 cm) relevant in brachytherapy. For the transport of photons and electrons, up-to-date and self-consistent total, partial and differential cross sections were used. The influence of coherent (Rayleigh) and incoherent (Compton) scattering, as well as the effects of the source and medium geometries on the calculations, were investigated in detail and it was found that these effects can lead to significant deviations from published data, especially at low energies and/or large distances from the sources. Our results can be used for any mono- or multi-energetic photon source in the energy range 20-1500 keV with uncertainties of the order of 2-3%, and they may influence treatment planning especially in the case of organs at risk which are usually near the edge of the body. PMID:1871210

Angelopoulos, A; Perris, A; Sakellariou, K; Sakelliou, L; Sarigiannis, K; Zarris, G

1991-06-01

76

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

SciTech Connect

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 could penetrate through ice grains significantly and trigger organic reactions several hundred nanometers deep-bulk chemistry thus competing with surface chemistry of astrophysical ice grains.

Barnett, Irene Li; Lignell, Antti; Gudipati, Murthy S., E-mail: gudipati@jpl.nasa.gov [Jet Propulsion Laboratory, California Institute of Technology, Mail Stop 183-301, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States)

2012-03-01

77

Calibration of Xray CCDs with an ErectField Grating Spectrometer in the 0.2 1.5 keV band.  

E-print Network

Calibration of X­ray CCDs with an Erect­Field Grating Spectrometer in the 0.2 ­ 1.5 keV band. G been calibrated in the 0.25­1.5 keV spectral range using an erect­field grating spectrometer X­ray CCDs developed at MIT Lincoln Laboratories for the AXAF CCD Imaging Spectrometer (ACIS) have

78

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

NASA Astrophysics Data System (ADS)

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 d?/d?, 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.

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

2006-05-01

79

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

NASA Technical Reports Server (NTRS)

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.

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

2007-01-01

80

Teflon impregnated anatase TiO2 nanoparticles irradiated by 80 keV Xe+ ions  

NASA Astrophysics Data System (ADS)

We report the effect of 80 keV Xe+ ion irradiation on the morphological and optical responses of TiO2 nanoparticles spread over commercially available polytetrafluoroethylene (PTFE, Teflon). These nanoparticles were synthesized via a convenient, sol-gel approach with titanium isopropoxide as the main precursor. From X-ray diffraction (XRD) studies we found that, the nanoparticles crystallize in anatase phase and with a preferential orientation of crystallites along (1 0 1) plane. Upon irradiation at a fluence of 1.25 × 1017 ions/cm2, the nanoparticle dimension was found to increase from a value of ˜9 nm to ˜20-30 nm. Essentially, particle growth is predicted as a consequence of swelling behavior accompanied by the formation of Xe van der Waal crystals in isolated regions of nano-titania. Evidence of nanoripples was also witnessed on the surface of the irradiated nano-titania. The morphological evolution was assessed both by atomic force and transmission electron microscopies (AFM and TEM) independently. From the UV-Vis optical absorption studies, the estimated optical band gap was found to drop with increasing fluence, while refractive index exhibited a remarkable improvement. Photoluminescence (PL) studies have revealed that, the band edge emission and those due to the self trapped excitons (STE) and other oxygen vacancy related ones were manifested considerably as a result of Xe ion irradiation.

Khanam, Rizwin; Paul, Nibedita; Kumar, P.; Kanjilal, D.; Ahmed, Gazi A.; Mohanta, Dambarudhar

2014-10-01

81

CUBIC: Measuring the X-ray background from 0.2 - 10 keV  

NASA Astrophysics Data System (ADS)

The CUBIC (Cosmic X-ray Background Instrument using CCDs) will be launched later this year to begin a three-year mission to measure the spectrum of the Diffuse X-ray Background. The instrument incorporates two CCDs for moderate non-dispersive spectral resolution in the bandpass 0.2 - 10.0 keV. The field of view is 5 x 5 degrees below 1 keV and 10 x 10 degrees above 3 keV. Observations will consist of 50,000 - 100,000 second integrations. The instrument was built at Penn State and has been integrated into the Argentine/US SAC-B satellite, which is now awaiting launch on a Pegasus XL vehicle. We describe the instrument design and performance specifications and present pre-flight calibration data.

Burrows, D. N.; Skinner, M. A.; Nousek, J. A.; Garmire, G. P.

1996-05-01

82

Omnibrowser 2.0  

NSDL National Science Digital Library

With a nice set of customizable skins and sounds, Omnibrowser 2.0 is worth taking a look at. This new shell program provides a tabbed browser function, automatic popup blocking, and the internalized ability to consult major search engines. As with most similar programs, visitors can add favorite sites quickly, and also view a complete browser history. OmniBrowser 2.0 is compatible with all systems running Windows XP.

83

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

NASA Astrophysics Data System (ADS)

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

Balta?, H.; Çevik, U.

2008-04-01

84

Gamma-ray burst spectra and time histories from 2 to 400keV  

NASA Astrophysics Data System (ADS)

The Gamma-Ray burst detector on Ginga consisted of a proportional counter to observe the x-rays and a scintillation counter to observe the gamma-rays. It was ideally suited to study the x-rays associated with gamma-ray bursts (GRBs). Ginga detected ~120 GRBs and 22 of them had sufficient statistics to determine spectra from 2 to 400keV. Although the Ginga and BATSE trigger criteria were very similar, the distribution of spectral parameters was different. Ginga observed bend energies in the spectra down to 2keV and had a larger fraction of bursts with low energy power law indexes greater than zero. The average ratio of energy in the x-ray band (2 to 10keV) compared to the gamma-ray band (50 to 300keV) was 24%. Some events had more energy in the x-ray band than in the gamma-ray band. One Ginga event had a period of time preceding the gamma rays that was effectively pure x-ray emission. This x-ray ``preactivity'' might be due to the penchant for the GRB time structure to be broader at lower energy rather than a different physical process. The x-rays tend to rise and fall slower than the gamma rays but they both tend to peak at about the same time. This argues against models involving the injection of relativistic electrons that cool by synchrotron radiation.

Fenimore, E. E.

1999-01-01

85

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

NASA Astrophysics Data System (ADS)

The broad-band X-ray spectra of active galactic nuclei (AGNs) contains information about the nuclear environment from Schwarzschild radii scales (where the primary power law is generated in a corona) to distances of ˜1 pc (where the distant reflector may be located). In addition, the average shape of the X-ray spectrum is an important input into X-ray background synthesis models. Here, local (z ? 0) AGN luminosity functions (LFs) in five energy bands are used as a low-resolution, luminosity-dependent X-ray spectrometer in order to constrain the average AGN X-ray spectrum between 0.5 and 200 keV. The 15-55 keV LF measured by Swift-BAT is assumed to be the best determination of the local LF, and then a spectral model is varied to determine the best fit to the 0.5-2 keV, 2-10 keV, 3-20 keV and 14-195 keV LFs. The spectral model consists of a Gaussian distribution of power laws with a mean photon-index and cutoff energy Ecut, as well as contributions from distant and disc reflection. The reflection strength is parametrized by varying the Fe abundance relative to solar, AFe, and requiring a specific Fe K? equivalent width (EW). In this way, the presence of the X-ray Baldwin effect can be tested. The spectral model that best fits the four LFs has = 1.85 ± 0.15, E_{cut}=270^{+170}_{-80} keV, A_{Fe}=0.3^{+0.3}_{-0.15}. The sub-solar AFe is unlikely to be a true measure of the gas-phase metallicity, but indicates the presence of strong reflection given the assumed Fe K? EW. Indeed, parametrizing the reflection strength with the R parameter gives R=1.7^{+1.7}_{-0.85}. There is moderate evidence for no X-ray Baldwin effect. Accretion disc reflection is included in the best-fitting model, but it is relatively weak (broad iron K? EW < 100 eV) and does not significantly affect any of the conclusions. A critical result of our procedure is that the shape of the local 2-10 keV LF measured by HEAO-1 and MAXI is incompatible with the LFs measured in the hard X-rays by Swift-BAT and RXTE. We therefore present a new determination of the local 2-10 keV LF that is consistent with all other energy bands, as well as the de-evolved 2-10 keV LF estimated from the XMM-Newton Hard Bright Survey. This new LF should be used to revise current measurements of the evolving AGN LF in the 2-10 keV band. Finally, the suggested absence of the X-ray Baldwin effect points to a possible origin for the distant reflector in dusty gas not associated with the AGN obscuring medium. This may be the same material that produces the compact 12 ?m source in local AGNs.

Ballantyne, D. R.

2014-01-01

86

Marketing 2.0  

ERIC Educational Resources Information Center

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)…

Germain, Carol Anne

2008-01-01

87

Inelastic Neutron Scattering Studies of Uranium -238 and THORIUM-232 on States above 300 KEV for Incident Energies above 2.2 Mev.  

NASA Astrophysics Data System (ADS)

Differential cross sections have been measured at incident energies from 2.3 to 3.0 MeV for vibrational states between 600 and 1000 keV in ^{232 } Th and ^{238}U, as well as for the 307.4 keV level in uranium and the 333.2 keV level in thorium which are members of ground state rotational band. Excitation functions for these levels have been obtained over the incident energy range 2.3-3.0 MeV in 100-keV steps. Angular distributions for these states were measured at 2.4 and 2.8 MeV. The data were obtained via the neutron time-of-flight technique using the University of Lowell 5.5 MV pulsed Van-de-Graaff accelerator with Mobley bunching system. Neutrons were generated via the ^7Li(p,n) ^7 Be reaction in a metalic lithium target having a thickness of 15-25 keV. Overall resolution of 25-30 keV was maintained throughout the measurements. The bunched pulse durations were less than 1 ns. Pulse shape discrimination (PSD) was employed to suppress gamma-ray background. Data reduction included, background, tail and fission subtraction; corrections were made for multiple scattering and for finite sample size effects. Studies were developed, employing a user interactive code to generate scattered neutron group response functions from the shape of elastic and inelastic scattering peaks obtained from measurements on elemental iron. The results are compared with theoretical calculations and previous measurements.

Aliyar, Abobakr

88

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)

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.

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

89

Solar wind control of Earth's H+ and O+ outflow rates in the 15eV to 33keV energy range  

Microsoft Academic Search

Earth's high-latitude outflow of H+ and O+ ions has been examined with the Toroidal Imaging Mass-Angle Spectrograph instrument on the Polar satellite in the 15-eV to 33-keV energy range over an almost 3-year period near solar minimum (1996-1998). This outflow is compared with solar wind plasma and interplanetary magnetic field (IMF) data from the Wind spacecraft, the latter having been

O. W. Lennartsson; H. L. Collin; W. K. Peterson

2004-01-01

90

Solar wind control of Earth's H+ and O+ outflow rates in the 15eV to 33keV energy range  

Microsoft Academic Search

Earth's high-latitude outflow of H+ and O+ ions has been examined with the Toroidal Imaging Mass-Angle Spectrograph instrument on the Polar satellite in the 15-eV to 33-keV energy range over an almost 3-year period near solar minimum (1996–1998). This outflow is compared with solar wind plasma and interplanetary magnetic field (IMF) data from the Wind spacecraft, the latter having been

O. W. Lennartsson; H. L. Collin; W. K. Peterson

2004-01-01

91

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

NASA Technical Reports Server (NTRS)

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.

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

2007-01-01

92

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

E-print Network

of relevance to cancer therapy techniques in which beams of accelerated ions are used to deliver localized doses of energy to kill cells within tumors (proton and hadron therapies) [Moretto-Capelle and Le1 20-150 keV proton impact induced ionization of uracil: fragmentation ratios and branching ratios

Paris-Sud XI, Université de

93

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

NASA Technical Reports Server (NTRS)

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

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

1987-01-01

94

Copywrite 2.0  

NSDL National Science Digital Library

In an effort to offer an alternative to various existing word processors and bundled office packages for home use, this new application offers a host of features designed to help writers working in a number of different styles and genres. Copywrite 2.0 features a flexible organization system, including an interface that allows writers to see how much progress they have made so far and, of course, inline spell checking, formatting, and a hyperlink feature as well. Copywrite 2.0 is free for small projects, while for larger projects individuals will have to purchase the product outright. This edition is compatible with all systems running Mac OS X 10.3 and higher.

95

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

NASA Technical Reports Server (NTRS)

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

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

1972-01-01

96

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

NASA Technical Reports Server (NTRS)

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

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

1982-01-01

97

Rovibrational excitation in collisions of He on D2 at energies less than 2 keV  

NASA Astrophysics Data System (ADS)

This work presents a theoretical study of rovibrational excitation in electronically elastic collisions of He on either H2 or D2 in the collision energy range 100 eV<=Einc<=2 keV. Earlier classical trajectory collision calculations, which predicted the rovibrational excitation energy to follow a universal scaling law, are here generalized to (1) encompass vibrational excitation caused by a three-body force representing the He interacting with the H2 covalent bond, and (2) incorporate quantization of vibrational excitation by a semiquantal ansatz imposed on the otherwise classical calculations. Quantization of vibrational excitation is shown to cause a breakdown of the scaling law predicted by the fully classical theory. The collisional excitation calculations utilize straight-line trajectories in the framework of the impulsive approximation, and are based on an improved parametric fit to the ab initio interaction energy surface for the HeH2 triatomic molecular system. In addition to the usual two-body Bohr and Born-Mayer terms describing the He-H interactions, the new interaction potential incorporates a three-body term to describe the contribution arising from the He interacting with the H-H covalent bond. The three-body force gives rise to some vibrational excitation phenomena, which are here explored. Good agreement is obtained with experimental measurements on rovibrational excitation energies produced in quasielastic collisions of He on D2

Muchnick, Paul; Russek, Arnold

1994-03-01

98

Planetary 2.0  

NSDL National Science Digital Library

Could there be a place where artists are stars? Albums are planets? Tracks are moons? Yes, yes, and yes. It is called Planetary 2.0 and it is a beautiful way to explore a music collection. Visitors can use this application with their music collection to create a series of wonderful visuals based on the planets, the stars, and various astronomical phenomena. Albums orbit around their artist star, the planet surface is derived from album cover art and the tracks are moons that orbit at a speed based on the length of the track. This version is compatible with all iPads running i0S 5.

2012-11-01

99

Charge fraction measurements for 2.4-35 keV Arq+ (q=2-13) projectiles  

E-print Network

Charge fraction measurements for 2.4-35 keV Arq+ (q=2-13) projectiles backscattered from Au(110 We report on measurements of absolute scattered projectile charge fractions for Arq+ ions (q=2- 13 separation of all scattered charged states, including neutrals. At fixed projectile energy, the scattered ion

100

The colouration of CaF2 crystals by keV and GeV ions  

NASA Astrophysics Data System (ADS)

CaF2 crystals have been implanted with a variety of ions of widely different energies and mass. Effects have been monitored using optical absorption in the range 120-750 nm. This includes the vacuum UV region. For 100 keV ions (Al, Mg, Kr) we observe extrinsic colloid bands in the case of implanted metal ions at high fluences (10(17) ions cm(2) ) but no colour centres (F, F-2 etc). For GeV ions (U, Ni) we observe prominent absorption bands in the visible region at fluences of 10(12) ions cm(-2) attributed to extrinsic calcium colloids. New optical features are discussed including an absorption band near 185 nm in the VUV and bands at 604 nm and 672 nm in the visible region.

Davidson, A. T.; Kozakiewicz, A. G.; Comins, J. D.; Derry, T. E.; Schwartz, K.; Trautmann, C.

101

Experimental response functions spanning the gamma-ray energy range of 123.6 keV to 11.67 MeV and response matrix generation for bismuth germanate scintillation detectors  

NASA Astrophysics Data System (ADS)

We report experimental response functions at 12 gamma-ray energies over the range of 123.6 keV to 11.67 MeV for a 2.54 cm diameter × 2.54 cm long and a 7.62 cm diameter × 7.62 cm long bismuth germanate scintillation detector. The measurements were made at, or corrected to correspond to, source-to-detector distances of 100 cm. The resolutions of the detectors at a gamma-ray energy of 661.6 keV are 11.6% for the small detector and 13.0% for the large detector. We also present an interpolation method for generating a response function at any gamma-ray energy in the range of 123.6 keV to 11.67 MeV for either scintillator using the experimental response functions. Additionally, this method is used in constructing response matrices for unfolding gamma-ray pulse-height distributions acquired with the detectors. A computer code written in FORTRAN-77 generates the response matrices.

Kiziah, Rex R.; Lowell, John R.

1991-07-01

102

Inferno 2.0  

NSDL National Science Digital Library

Inferno, created at Lucent Technologies' Bell Labs, is a new operating system that could be the "Unix for the next century." Created by the same research lab that invented C++ and Unix, Inferno's primary goal is to operate seamlessly within a heterogeneous network environment. By abstracting resource interfaces to a common format, Inferno provides a general way to access all resources, both local and remote. Beyond that, the operating system is portable across many platforms and networks, and applications written in Limbo, the Inferno programming language, are also portable and lightweight. Impossible to describe in a single paragraph, the Inferno operating system is a fascinating leap ahead in networking and systems technology. Inferno is useful for research, development, learning, and many other possibilities. Freely available, Inferno 2.0 runs on Win95/NT, Solaris, and Linux.

1998-01-01

103

Energy loss and angular dispersion of 2-200 keV protons in amorphous silicon  

NASA Astrophysics Data System (ADS)

The energy loss of 2-200 keV protons in thin amorphous silicon foils has been measured for projectiles transmitted in the forward direction and as a function of the exit angle. At the lowest energies, differences of up to 30% with recently published values are observed. Angular effects in the energy loss, at low and high energies, have been investigated. The low-energy results are reproduced by model calculations and Monte Carlo simulations, which indicate that the inelastic energy loss does not show a dependence upon the impact parameter in the low energy region. A fitting formula for the present energy loss values is provided.

Famá, M.; Lantschner, G. H.; Eckardt, J. C.; Arista, N. R.; Gayone, J. E.; Sanchez, E.; Lovey, F.

2002-06-01

104

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

NASA Astrophysics Data System (ADS)

We have calculated Triply differential cross sections (TDCS) and doubly differential cross sections (DDCS) for single ionization of H2 by 75 keV proton impact using the molecular 3 body distorted wave Eikonal initial state (M3DW-EIS) approach. Previously published measured DDCS-P (differential in the projectile scattering angle and integrated over the ejected electron angles) found pronounced structures at relatively large angles which were interpreted as an interference resulting from the two-centered potential of the molecule.

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

2012-11-01

105

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)

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.

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

1997-01-01

106

Study of natMg(d,d0) reaction at detector angles between 90° and 170°, for the energy range Ed,lab=1660-1990 keV  

NASA Astrophysics Data System (ADS)

In the present work, the study of the natMg(d,d0) is presented for the energy range Ed,lab = 1660-1990 keV (in steps of 5 keV), for detector angles between 90° and 170°. Elastic scattering data for two forward angles (55° and 70°) were also obtained. In order to validate the obtained experimental results a thick Mg sample with Au evaporated on top was fabricated and benchmarking measurements were performed at various deuteron beam energies. The results of the present work are complementary to the recently published 24Mg(d,p0,1,2) reaction cross section data, thus facilitating the simultaneous depth profiling study of magnesium by both the d-NRA and EBS techniques.

Patronis, N.; Aslanoglou, X.; Axiotis, M.; Georgiadou, A.; Kokkoris, M.; Lagoyannis, A.; Misaelides, P.; Paneta, V.

2014-10-01

107

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

NASA Technical Reports Server (NTRS)

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.

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

1996-01-01

108

The production and sputtering of S2 by keV ion bombardment  

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

109

Differential cross sections for single ionization of H2 by 75-keV proton impact  

NASA Astrophysics Data System (ADS)

We have calculated triply differential cross sections (TDCS) and doubly differential cross sections (DDCS) for single ionization of H2 by 75-keV proton impact using the molecular three-body distorted-wave-eikonal initial-state (M3DW-EIS) approach. Previously published measured DDCS (differential in the projectile scattering angle and integrated over the ejected electron angles) found pronounced structures at relatively large angles that were interpreted as an interference resulting from the two-centered potential of the molecule. Theory treating H2 as atomic H multiplied by a molecular interference factor only predicts the observed structure when assumptions are made about the molecular orientation. Here we apply the M3DW-EIS method, which does not rely on such an ad hoc approach, but rather treats the interference from first principles.

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

2011-03-01

110

Xenopatients 2.0  

PubMed Central

In the science-fiction thriller film Minority Report, a specialized police department called “PreCrime” apprehends criminals identified in advance based on foreknowledge provided by 3 genetically altered humans called “PreCogs”. We propose that Yamanaka stem cell technology can be similarly used to (epi)genetically reprogram tumor cells obtained directly from cancer patients and create self-evolving personalized translational platforms to foresee the evolutionary trajectory of individual tumors. This strategy yields a large stem cell population and captures the cancer genome of an affected individual, i.e., the PreCog-induced pluripotent stem (iPS) cancer cells, which are immediately available for experimental manipulation, including pharmacological screening for personalized “stemotoxic” cancer drugs. The PreCog-iPS cancer cells will re-differentiate upon orthotopic injection into the corresponding target tissues of immunodeficient mice (i.e., the PreCrime-iPS mouse avatars), and this in vivo model will run through specific cancer stages to directly explore their biological properties for drug screening, diagnosis, and personalized treatment in individual patients. The PreCog/PreCrime-iPS approach can perform sets of comparisons to directly observe changes in the cancer-iPS cell line vs. a normal iPS cell line derived from the same human genetic background. Genome editing of PreCog-iPS cells could create translational platforms to directly investigate the link between genomic expression changes and cellular malignization that is largely free from genetic and epigenetic noise and provide proof-of-principle evidence for cutting-edge “chromosome therapies” aimed against cancer aneuploidy. We might infer the epigenetic marks that correct the tumorigenic nature of the reprogrammed cancer cell population and normalize the malignant phenotype in vivo. Genetically engineered models of conditionally reprogrammable mice to transiently express the Yamanaka 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

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

2014-01-01

111

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

NASA Astrophysics Data System (ADS)

We have calculated Triply differential cross sections (TDCS) and doubly differential cross sections (DDCS) for single ionization of by 75 KeV proton impact using the molecular 3 body distorted wave Eikonal initial state (M3DW-EIS) approach. Previously published measured DDCS (differential in the projectile scattering angle and integrated over the ejected electron angles) found pronounced structures at relatively large angles which were interpreted as an interference resulting from the two-centered potential of the molecule. Theory treating H2 as atomic H multiplied by a molecular interference factor only predict the observed structure when assumptions are made about the molecular orientation. Here we apply the M3DW-EIS method, which does not rely on such an ad hoc approach, but rather treats the interference from first principles and we find the same structure without assuming any preferential orientations.

Chowdhury, Uttam; Schulz, Michael; Madison, Don

2011-06-01

112

-/20-2-2009 -/20-2-2009  

E-print Network

;-/20-2-2009 µ µ µ Sample Detector Shield Collimated transmission source shieldHPGe Detector 210 240 270 300 10-on limit Recycling limit EASY: First wall neutron spectrum, 5 y irradiation at 1 MW/m2 load Nucl. Instr% Rod Withdrawal k/k Measured Calculated - MCNP . , 2009 #12;-/20-2-2009 µ µ . , 2009 Neutron Energy

113

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

PubMed

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

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

2008-10-10

114

Understanding Web 2.0  

Microsoft Academic Search

Web 2.0, the second phase in the Web's evolution, is attracting the attention of IT professionals, businesses, and Web users. Web 2.0 is also called the wisdom Web, people-centric Web, participative Web, and read\\/write Web. Web 2.0 harnesses the Web in a more interactive and collaborative manner, emphasizing peers' social interaction and collective intelligence, and presents new opportunities for leveraging

San Murugesan

2007-01-01

115

BASINS 2.0  

NSDL National Science Digital Library

The Environmental Protection Agency (EPA) first created BASINS (Better Assessment Science Integrating Point and Nonpoint Sources) in 1996 as an aid to water resource planners concerned with water quality and watershed analyses. The strength of BASINS is its integration of \\"a geographic information system (GIS), national watershed data, and state-of-the-art environmental assessment and modeling tools.\\" The updated version of the program, BASINS 2, can be downloaded from this site.

116

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

SciTech Connect

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.

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

2011-02-08

117

Xenon-neon gas proportional-scintillation counters for X rays below 2 keV: experimental results  

Microsoft Academic Search

The energy spectra of X-rays with energies below 2 keV measured with standard Xe filled gas proportional scintillation counters at atmospheric pressure exhibit a distorted tail towards the low energy region, due to the loss of electrons to the detector entrance window. In this framework, a Monte Carlo simulation study taking into account these losses has previously investigated the use

F. I. G. M. Borges; F. P. Santos; J. M. F. dos Santos; T. H. V. T. Dias; P. J. B. M. Rachinhas; C. A. N. Conde

2002-01-01

118

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)

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) ?i] 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. ?i 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 solutions decreases with pressure. The in situ measurements of electric conductances of the water-rock interaction system at temperature range from 20-435°C, 23-36MPa were performed using the flow system. The in situ measurements of electric conductances combined the kinetic experiments found that the maximum electric conductances are present at 374-390°C, 23-36MPa, and simultaneously the maximum release rates of Si, Al, K are reached at the same temperature range. These results provide useful information for estimating the behavior of crustal fluids and the geophysical nature of the mid-crust. Note: These studies reported here have been supported by the Ministry of Land and Resources and the Ministry of Science and Technology: k[2013]01-062-014, SinoProbe-07-02-03, SinoProbe-03-01-2A, 20010302 and project of Anhui Province (2010G28). Key words: chemical kinetics, critical state, syenite-water interaction, electric conductance, high conductivity zone, high temperature experiment.

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

2013-12-01

119

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

SciTech Connect

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.

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

1996-03-01

120

Augmented Reality 2.0  

NASA Astrophysics Data System (ADS)

Augmented Reality (AR) was first demonstrated in the 1960s, but only recently have technologies emerged that can be used to easily deploy AR applications to many users. Camera-equipped cell phones with significant processing power and graphics abilities provide an inexpensive and versatile platform for AR applications, while the social networking technology of Web 2.0 provides a large-scale infrastructure for collaboratively producing and distributing geo-referenced AR content. This combination of widely used mobile hardware and Web 2.0 software allows the development of a new type of AR platform that can be used on a global scale. In this paper we describe the Augmented Reality 2.0 concept and present existing work on mobile AR and web technologies that could be used to create AR 2.0 applications.

Schmalstieg, Dieter; Langlotz, Tobias; Billinghurst, Mark

121

Possibility of Forming 18-nm-Pitch Ultrahigh Density Fine Dot Arrays for 2 Tbit/in.2 Patterned Media Using 30-keV Electron Beam Lithography  

NASA Astrophysics Data System (ADS)

We studied the possibility of forming ultrahigh-density fine dot arrays using 30-keV electron beam (EB) drawing for 2 Tbit/in.2 patterned media. We investigated the effects of calixarene resist thickness and exposure dosage on the drawing of dot arrays with a minimum pitch. We found that the 13-nm-thick calixarene resist was very suitable for forming resist dot arrays with a pitch of 20 nm. Furthermore, the allowable region of proper exposure dosage became narrow as the pitch decreased. It is clarified that there exists a minimum pitch of 18 nm in drawing ultrahigh density fine dot arrays with a 13-nm-thick resist.

Sumio Hosaka,; Yasunari Tanaka,; Masumi Shirai,; Zulfakri Mohamad,; You Yin,

2010-04-01

122

Web 2.0 dictionary  

Microsoft Academic Search

How might we beneflt from the billions of tagged multime- dia flles (e.g. image, video, audio) available on the Internet? This paper presents a new concept called Web 2.0 Dictio- nary, a dynamic dictionary that takes advantage of, and is in fact built from, the huge database of tags available on the Web. The Web 2.0 Dictionary distinguishes itself from

Qingxiong Yang; Xin Chen; Gang Wang

2008-01-01

123

Developing a Compton Polarimeter to Measure Polarization of Hard X-Rays in the 50-300 keV Energy Range  

E-print Network

This paper discusses the latest progress in the development of GRAPE (Gamma-Ray Polarimeter Experiment), a hard X-ray Compton Polarimeter. The purpose of GRAPE is to measure the polarization of hard X-rays in the 50-300 keV energy range. We are particularly interested in X-rays that are emitted from solar flares and gamma-ray bursts (GRBs). Accurately measuring the polarization of the emitted radiation from these sources will lead, to a better understating of both the emission mechanisms and source geometries. The GRAPE design consists of an array of plastic scintillators surrounding a central high-Z crystal scintillator. We can monitor individual Compton scatters that occur in the plastics and determine whether the photon is photo absorbed by the high-Z crystal or not. A Compton scattered photon that is immediately photo absorbed by the high-Z crystal constitutes a valid event. These valid events provide us with the interaction locations of each incident photon and ultimately produces a modulation pattern for the Compton scattering of the polarized radiation. Comparing with Monte Carlo simulations of a 100% polarized beam, the level of polarization of the measured beam can then be determined. The complete array is mounted on a flat-panel multi-anode photomultiplier tube (MAPMT) that can measure the deposited energies resulting from the photon interactions. The design of the detector allows for a large field-of-view (>pi steradian), at the same time offering the ability to be close-packed with multiple modules in order to reduce deadspace. We plan to present in this paper the latest laboratory results obtained from GRAPE using partially polarized radiation sources.

J. S. Legere; P. Bloser; J. R. Macri; M. L. McConnell; T. Narita; J. M. Ryan

2005-08-14

124

Dependence of spectral shape of bremsstrahlung spectra on atomic number of target materials in the photon energy range of 5-30 keV  

NASA Astrophysics Data System (ADS)

Dependence of spectral shape of total bremsstrahlung spectra i.e. the sum of ordinary bremsstrahlung (OB) and polarization bremsstrahlung (PB), on the atomic number ( Z) of target materials (Al, Ti, Sn and Pb), produced by continuous beta particles of 90Sr and 204Tl, has been investigated in the photon energy region of 5-30 keV. It has been found that the spectral shape of total bremsstrahlung spectra, in terms of S ( k, Z) i.e. the number of photons of energy k per moc2 per beta disintegration, is not linearly dependent on the atomic number ( Z) of the target material and rather it is proportional to Zn. At lower photon energies, the index values ' n' of Z-dependence are much higher than unity, which is due to the larger contribution of PB into OB. The decrease in ' n' values with increase of photon energy is due to the decrease in contribution of PB into OB. It is clear that the index ' n' values obtained from the modified Elwert factor (relativistic) Bethe-Heitler theory, which include the contribution PB into OB, are in agreement with the experimentally measured results using X-PIPS Si(Li) detector. Hence the contribution of PB into the formation of a spectral shape of total bremsstrahlung spectra plays a vital role.

Singh, Tajinder; Kahlon, K. S.; Dhaliwal, A. S.

2012-02-01

125

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

SciTech Connect

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

Mclean, Thomas D [Los Alamos National Laboratory; Justus, Alan L [Los Alamos National Laboratory; Gadd, S Milan [Los Alamos National Laboratory; Olsher, Richard H [RP-2; Devine, Robert T [RP-2

2009-01-01

126

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

PubMed

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. PMID:23415108

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

2014-01-01

127

iPodder 2.0  

NSDL National Science Digital Library

Streaming audio programs on the Web are of great interest to many, and range from those programs sponsored by various policy institutes to popular music programs. Unfortunately, sometimes individuals cannot be present when their favorite programs are broadcast over the Internet. Stepping in to assist users is iPodder 2.0, which allows them to select and download audio files from anywhere on the Internet to their desktops. Also, users can use the application to download various audio files at specific times as well. iPodder 2.0 is compatible with Windows 2000 or XP and Mac OS 10.3 or newer.

128

Shifting of the electron-capture-to-the-continuum peak in proton-helium collisions at 10 and 20 keV  

SciTech Connect

A refined theoretical approach has been developed to study the double-differential cross sections (DDCS's) in proton-helium collisions as a function of the ratio of ionized electron velocity to the incident proton velocity. The refinement is done in the present coupled-channel calculation by introducing a continuum distorted wave in the final state coupled with discrete states including direct as well as charge transfer channels. It is confirmed that the electron-capture-to-the-continuum (ECC) peak is slightly shifted to a lower electron velocity than the equivelocity position. Comparing measurements and classical trajectory Monte Carlo (CTMC) calculations at 10 and 20 keV proton energies, excellent agreement of the ECC peak heights is achieved at both energies. However, a minor disagreement in the peak positions between the present calculation and the CTMC results is noted. A smooth behavior of the DDCS is found in the present calculation on both sides of the peak whereas the CTMC results show some oscillatory behavior particularly to the left of the peak, associated with the statistical nature of CTMC calculations.

Bhattacharya, S. [Department of Physics, Surendranath College, Kolkata 700 009 (India); Deb, N.C.; Roy, K. [Department of Theoretical Physics, Indian Association for the Cultivation of Science, Jadavpur, Calcutta 700 032 (India); Sahoo, S.; Crothers, D.S.F. [Department of Applied Mathematics and Theoretical Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland (United Kingdom)

2005-01-01

129

Indie Toolbar 2.0  

NSDL National Science Digital Library

Developed by Alexander Wilson, this handy little application allows users to create a customizable standalone internet toolbar. This latest version also contains a host of new icons, bringing the total that may be used to over 300. The icons themselves are divided into a number of different themes such as those related to Macs, and those representing the Web sites of different nonprofit organizations. The Web site for Indie Toolbar 2.0 also features several screen shots and an area where users can send bug reports to Mr. Wilson directly. Indie Toolbar 2.0 is compatible with all systems running Mac OS X 10.1 and higher or Windows 95 and higher.

130

Spatially Explicit Regions Of Peak Velocity Are Highly Differentiated At Different Discharges Ranging from 0.2 to 20 Times Bankfull In A Dynamic Gravel/Cobble Bed River  

NASA Astrophysics Data System (ADS)

Previous studies have identified velocity and Shield stress reversals as key mechanisms that maintain riffle-pool morphology. However, those studies have 4 primary limitations: (1) generally small stream size, (2) narrow range of discharge rarely above bankfull, (3) few analyzed cross-sections, and (4) simple binary characterization of channel morphology as riffle or pool. The goal of this study was to develop and assess spatially explicit indicators of velocity reversal and relate them to landform attributes. The four test variables were (1) mean and maximum velocity with increasing discharge for diverse sub-width morphological units (MUs), (2) percent overlap of peak velocity areas (i.e. spatial persistence) between different discharges, (3) distribution of area of peak velocity among MUs with increasing discharge, and (4) percent of total areas of individual MUs that occurs within peak velocity regions with increasing discharge. The testbed for this study was the Lower Yuba River (LYR), a regulated gravel-cobble bed river with an active floodplain that provides anadromous salmonid habitat. Hydraulics were predicted with a validated 2D hydraulic model over 35 km at 1 m resolution for discharges ranging from 0.2-20 times bankfull. Fluvial landforms were classified into 8 reaches, 4 inundation zones, and 31 MUs. This study compared results for a wide meandering reach and a narrow valley-confined reach. At low discharge, high velocities in the wide alluvial reach occurred due to flow constriction imposed by in-channel bars, but with increasing discharge these regions of high velocity shifted to meander bends where vortex flow dominates. The narrower reach exhibited a similar spatial occurrence of the highest velocities at low discharge due to in-channel bars, but upon inundation of these features the valley walls and bedrock outcrops activated as hydraulic controls. In contrast to small streams, these controls activate at flows much greater than bankfull discharge, around ~2x Qb and ~7x Qb for the wide and narrow reaches, respectively. The activation discharges in both reaches produce mean velocity reversals among multiple MU pairs, but these discharges also mark convergence in maximum velocity that is sustained with increased discharge among the majority of the MUs. The discharges at which mean MU velocity reversals occur correspond to approximately 35% (wide reach) and 10% (narrow reach) overlaps in area of peak velocity as compared to the baseflow pattern; in other words, areas of peak velocity are highly differentiated. The two reaches experience mean MU velocity reversals at discharges that correspond well to the discharges at which both of the following occur: reversals in MU composition of the peak velocity areas, and reversals in the fraction of total reach areas of individual MUs that occurs within regions of peak velocity. These results suggest that spatial trends in peak velocities for large gravel-cobble bed rivers may be useful in predicting the occurrence of mean velocity reversals for fluvial landforms.

Strom, M.; Depsky, N. J.; Wyrick, J. R.; Pasternack, G. B.

2012-12-01

131

28 CFR 20.2 - Authority.  

Code of Federal Regulations, 2010 CFR

...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...

2010-07-01

132

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

PubMed

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

Trunova, Valentina; Sidorina, Anna; Kriventsov, Vladimir

2014-10-17

133

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

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

134

POP Peeper 2.0  

NSDL National Science Digital Library

Supported by all Windows operating systems, POP Peeper 2.0 is a small utility that resides in your Windows task bar and informs users when they have new email from any of their POP3, MSN, Yahoo, or Hotmail accounts. Additionally, the POP Peeper supports HTML email. Finally, the utility allows users to be notified of new email from any of these accounts with a visual or audial reminder. The POP Peeper Web site also has a handy FAQ section that addresses problems or questions users might have.

2002-01-01

135

Visible and VUV optical absorption studies of Mg-colloids and colour centres in MgF 2 crystals implanted by 100 keV Mg-ions  

NASA Astrophysics Data System (ADS)

100 keV Mg ions have been implanted into MgF 2 crystals with a fluence of 10 17 ions/cm 2 at liquid nitrogen temperature. After warming to room temperature optical absorption measurements over the range 2.0-11.5 eV revealed F-type centres in the visible spectral region and bands at 7.8 eV and near 6.5 eV in the vacuum ultraviolet region. Analysis of defect annealing at elevated temperatures showed a mutual decay of the latter bands with the F-type centres and thereby their association with complementary fluorine interstitial defects. The growth and decay of a Mg colloid band near 4.43 eV was studied. At the highest annealing temperatures an XPS analysis shows that oxygen diffuses into the crystal forming MgO near the implanted surface, thus substantially modifying the optical absorption spectrum.

Amolo, G. O.; Comins, J. D.; Davidson, A. T.; Kozakiewicz, A. G.; Derry, T. E.; McLachlan, D. S.

2004-06-01

136

The photoabsorption of BF 3 in the energy range 6.5-20 eV  

NASA Astrophysics Data System (ADS)

The absorption spectrum of BF 3 has been measured in the photon energy range 6.5-20 eV using monochromatized synchrotron radiation. Assignments have been made on the basis of term value and symmetry arguments. The ???* (1e??2a? 2) transition is centered at 13.13 eV, whereas a second excitation to ?* (2a'?2a? 2) is located at 17.52 eV. Another valence-type transition (1a' 2?5a' 2) is connected with an excitation energy of 15.64 eV. All final states of the valence-type transitions have term values between 3.5 and 4.0 eV. The first member of an n-type Rydberg series converging to the 2E' ionization energy is assigned to a transition to the Rydberg mixed-valence final orbital 3s+?* (5a' 1). Members of np and nd type Rydberg series converging to the 1A' 2 ionization energy are located in the energy range 13.7? hv ? 15.4 eV. The dense vibrational features centered around 18.5 eV consist of five Rydberg series excited from 2E'. Shape resonance effects in the valence shell spectrum of BF 3 are discussed.

Hagenow, G.; Hottmann, K.; Jochims, H. W.; Baumgärtel, H.

1989-10-01

137

eLearning 2.0 . , . ,,"8, ,, "  

E-print Network

­ eLearning 2.0 . . , -, . , -, . , . - ,, ", . , . ,,"8, ,, " aivanova@ecs.ru.acad.bg , . , - , , , . () , 1981. . . ,,-". , , . ­ . 21 , ,,-" 10 000 -, 200 000 e-, 20 000 Education.au Seminars #12; eLearning 2.0, Stephen Downes, , WEB 2.0. eLearning 2

Borissova, Daniela

138

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

NASA Astrophysics Data System (ADS)

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

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

2012-01-01

139

Art Education 2.0  

NSDL National Science Digital Library

Craig Roland created this site for fellow travelers and art educators in order to help colleagues find out how to use new technologies in their classrooms. First-time visitors will need to start out by signing up for a free account, and after that they are most welcome to participate in forums, groups, blogs, RSS feeds, and photo and video sharing. Some of the groups include "Art Partners", "Students of Art Education 2.0", and "First Year Art Teachers". The forums are quite useful, and recently they have included discussions on summer research opportunities, arts censuses, and the use of streaming video in the classroom. For art educators, this site is quite a find, and others who are interested in art and technology more generally will also find it useful.

Roland, Craig

140

The PLATO 2.0 mission  

NASA Astrophysics Data System (ADS)

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 diversity for low-mass objects, - correlate the planet mean density-orbital distance distribution with predictions from planet formation theories,- constrain the influence of planet migration and scattering on the architecture of multiple systems, and - specify how planet and system parameters change with host star characteristics, such as type, metallicity and age. The catalogue will allow us to study planets and planetary systems at different evolutionary phases. It will further provide a census for small, low-mass planets. This will serve to identify objects which retained their primordial hydrogen atmosphere and in general the typical characteristics of planets in such low-mass, low-density range. Planets detected by PLATO 2.0 will orbit bright stars and many of them will be targets for future atmosphere spectroscopy exploring their atmosphere. Furthermore, the mission has the potential to detect exomoons, planetary rings, binary and Trojan planets. The planetary science possible with PLATO 2.0 is complemented by its impact on stellar and galactic science via asteroseismology as well as light curves of all kinds of variable stars, together with observations of stellar clusters of different ages. This will allow us to improve stellar models and study stellar activity. A large number of well-known ages from red giant stars will probe the structure and evolution of our Galaxy. Asteroseismic ages of bright stars for different phases of stellar evolution allow calibrating stellar age-rotation relationships. Together with the results of ESA's Gaia mission, the results of PLATO 2.0 will provide a huge legacy to planetary, stellar and galactic science.

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, ?.; Smith, A.; Suárez, J.-C.; Szabó, R.; Udry, S.; Adibekyan, V.; Alibert, Y.; Almenara, J.-M.; Amaro-Seoane, P.; Ammer-von Eiff, M.; 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.; Oliveira Fialho, F. de; 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.

2014-09-01

141

The PLATO 2.0 mission  

NASA Astrophysics Data System (ADS)

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 diversity for low-mass objects, - correlate the planet mean density-orbital distance distribution with predictions from planet formation theories,- constrain the influence of planet migration and scattering on the architecture of multiple systems, and - specify how planet and system parameters change with host star characteristics, such as type, metallicity and age. The catalogue will allow us to study planets and planetary systems at different evolutionary phases. It will further provide a census for small, low-mass planets. This will serve to identify objects which retained their primordial hydrogen atmosphere and in general the typical characteristics of planets in such low-mass, low-density range. Planets detected by PLATO 2.0 will orbit bright stars and many of them will be targets for future atmosphere spectroscopy exploring their atmosphere. Furthermore, the mission has the potential to detect exomoons, planetary rings, binary and Trojan planets. The planetary science possible with PLATO 2.0 is complemented by its impact on stellar and galactic science via asteroseismology as well as light curves of all kinds of variable stars, together with observations of stellar clusters of different ages. This will allow us to improve stellar models and study stellar activity. A large number of well-known ages from red giant stars will probe the structure and evolution of our Galaxy. Asteroseismic ages of bright stars for different phases of stellar evolution allow calibrating stellar age-rotation relationships. Together with the results of ESA's Gaia mission, the results of PLATO 2.0 will provide a huge legacy to planetary, stellar and galactic science.

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, ?.; 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

142

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

SciTech Connect

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

Chowdhury, U.; Schulz, M.; Madison, D. H. [Missouri University of Science and Technology, Department of Physics and Laboratory for Atomic, Molecular, and Optical Research, Rolla, Missouri 65401 (United States)

2011-03-15

143

Validation Results for LEWICE 2.0  

NASA Technical Reports Server (NTRS)

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%.

Wright, William B.; Rutkowski, Adam

1999-01-01

144

The solar wind charge-transfer X-ray emission in the 1/4 keV energy range: inferences on Local Bubble hot gas at low Z  

E-print Network

We present calculations of the heliospheric SWCX emission spectra and their contributions in the ROSAT 1/4 keV band. We compare our results with the soft X-ray diffuse background (SXRB) emission detected in front of 378 identified shadowing regions during the ROSAT All-Sky Survey (Snowden et al. 2000). This foreground component is principally attributed to the hot gas of the so-called Local Bubble (LB), an irregularly shaped cavity of ~50-150 pc around the Sun, which is supposed to contain ~10^6 K plasma. Our results suggest that the SWCX emission from the heliosphere is bright enough to account for most of the foreground emission towards the majority of low galactic latitude directions, where the LB is the least extended. In a large part of directions with galactic latitude above 30deg the heliospheric SWCX intensity is significantly smaller than the measured one. However, the SWCX R2/R1 band ratio differs slightly from the data in the galactic center direction, and more significantly in the galactic anti-centre direction where the observed ratio is the smallest. Assuming that both SWCX and hot gas emission are present and their relative contributions vary with direction, we tested a series of thermal plasma spectra for temperatures ranging from 10^5 to 10^6.5 K and searched for a combination of SWCX spectra and thermal emission matching the observed intensities and band ratios, while simultaneously being compatible with O VI emission measurements. In the frame of collisional equilibrium models and for solar abundances, the range we derive for hot gas temperature and emission measure cannot reproduce the Wisconsin C/B band ratio. We emphasize the need for additional atomic data, describing consistently EUV and X-ray photon spectra of the charge-exchange emission of heavier solar wind ions.

D. Koutroumpa; R. Lallement; J. C. Raymond; V. Kharchenko

2008-12-19

145

Introducing ADS 2.0  

NASA Astrophysics Data System (ADS)

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.

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

2014-01-01

146

WMS Server 2.0  

NASA Technical Reports Server (NTRS)

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.

Plesea, Lucian; Wood, James F.

2012-01-01

147

Experimental evidence for the curve crossing mechanism for collisional excitation in keV N2+*/He collisions by emission spectroscopy.  

PubMed

Collision-induced emission (CIE) experiments were carried out by coupling a spectrograph and charge-coupled device detector (CCD) to a commercial analytical mass spectrometer. An Einzel lens and a deceleration-reacceleration lens assembly as described in the current article were installed in the mass spectrometer to allow for the deceleration of the ions before collision. Collision-induced emission spectra of N2+*/He collisions at lab frame collision energies from 2 to 8 keV were obtained from 190-1020 nm. The emissions were assigned to the Deltav=+2, +1, 0, -1, -2 vibrational transition progression in the N2+* B 2Sigmau+-->X 2Sigmag+ electronic transition as well as some atomic lines from the fragments N+, N* and the target gas He. N2+* A 2u-->X 2Sigmag+ emission was also observed but was very weak due to the long lifetime of the A 2u state. The relative intensities of the N2+*, N, and N+ emissions are independent of the ion translational energy within the studied energy range. This observation supports the curve-crossing mechanism for collisional excitation, suggesting that a complicated sequence of curve-crossings takes place upon collisional activation. PMID:17266217

Poon, Clement; Mayer, Paul M

2007-02-01

148

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

PubMed

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

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

2015-02-01

149

Beryllium and Graphite High-Accuracy Total Cross-Section Measurements in the Energy Range from 24 to 900 keV  

E-print Network

Beryllium and Graphite High-Accuracy Total Cross-Section Measurements in the Energy Range from 24 new measurements of the carbon and beryllium neutron total cross section in the energy range of 24. Measurements of three samples of different thicknesses of beryllium resulted in accurate total cross

Danon, Yaron

150

Evaluation of powder/granular Gd2O2S:Pr scintillator screens in single photon counting mode under 140 keV excitation  

NASA Astrophysics Data System (ADS)

The aim of this paper is the evaluation of an alternative, low cost solution for the gamma detector in planar imaging. It is based on a powder scintillator, well established in X-ray imaging, and could be further exploited in simultaneous bimodal imaging systems. For this purpose, we have examined the performance of Gd2O2S:Pr powder scintillator, in the form of thick granular screens easily produced in the laboratory by commercially available Gd2O2S:Pr powder. The screen was coupled to a round position sensitive photomultiplier tube (R3292 PSPMT). The system's evaluation was performed in photon counting mode under 99mTc excitation. In all measurements, a general purpose hexagonal parallel collimator was used. Different samples of screens with coating thickness varying from 0.1 g/cm2 to 1.2 g/cm2 were tested. The 0.6 g/cm2 screen, corresponding to ~ 2 mm actual thickness, was found most efficient under 140 keV irradiation. The system`s performance with the proposed screen is reported with the modulation transfer function. Moreover sensitivity, spatial and energy resolution as well as the uniformity response using phantoms were measured. The performance of the proposed screen was compared with two CsI:Tl pixellated crystal arrays with 2 × 2 × 3 mm3 and 3 × 3 × 5 mm3pixel size. A spatial resolution, of 3 mm FWHM, for a 99mTc line source, was achieved at zero source to collimator distance. In addition, the Gd2O2S:Pr screen showed a slower degradation of the spatial resolution with increasing source to collimator distance e.g at 20 cm, the Gd2O2S:Pr screen showed aq spatial resolution of 8.4 mm while the spatial resolution of the pixellated crystals was 15 mm. Taking into account its easy production, its flexibility due to powder form, the very low cost and the good spatial resolution properties of the proposed alternative detector, powder scintillators could potentially be used for the construction of flexible detector geometries, such as ring type or gamma probes or as a low cost detector solution in educational photon counting imaging applications, complementary to standard X-ray imaging.

David, S.; Georgiou, M.; Loudos, G.; Michail, C.; Fountos, G.; Kandarakis, I.

2013-01-01

151

Using Web 2.0 to Collaborate  

ERIC Educational Resources Information Center

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…

Buechler, Scott

2010-01-01

152

Unique Spectral Features Search In The 20 - 35 Micron Range of Mgs Tes Data  

NASA Astrophysics Data System (ADS)

TES is the Thermal Emission Spectrometer aboard the NASA mission Mars Global Surveyor (MGS) orbiting around Mars since September 1997. It is collecting 6 - 50 micron thermal emission spectra and one of its principal purposes is to determine and map the Mars surface composition. Spectral features directly ascribable to sur- face minerals have been identified in the 20 - 35 micron spectral range: deposits of crystalline gray hematite have been localized in three regions, Sinus Meridiani, Aram Chaos and Valles Marineris [1, 2], and outcrops of olivines have been individuated in Nili Fossae [3]. The crystalline gray hematite areas have been interpreted to be formed by aqueous mineralization, indicating that liquid water was stable near the Mars sur- face for a long period of time in some limited regions. On the other hand there is no evidence in TES data for large scale occurrences (< 10 km) of moderate-grained (> 50 micron) carbonates exposed at the surface at a detection limit of 10 % [2]. Mars thermal emission spectra show, in general, significant variance between 20 and 35 mi- cron. This variance is not directly attributable to surface mineralogical components for the difficulty of discriminating the contribute of atmospheric components: CO2 and water vapour gas, dust and water ice aerosols. Moreover, the dust layer deposited on the soil has a spectral masking effect, obscuring superficial signature related to smaller mineral deposit and making difficult their identification. In this study we report some examples of single TES spectra with typical hematite and olivine bands and spectra with other unique features in the 20 - 35 micron range likely related to superficial components. For some of them we have analysed how the spectral features change in two different Mars seasons. These single TES pixels could be best investigated by instruments with an higher spatial resolution, as THEMIS and OMEGA. References: [1] Christensen P. R., et al., JGR, 105, 9623-9642, 2000. [2] Christensen P. R., et al., JGR,106, 23823-23871, 2001. [3] Hoefen T. M. and Clark R. N., LPS XXXII, 2049, 2001.

Altieri, F.; Bellucci, G.

153

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)

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.

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

1994-01-01

154

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

SciTech Connect

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 EBT3 film prototype with 7.5% Si shows a significant improvement in the energy response at very low energies compared to the commercial EBT3 films with 4% Cl. It shows under response of 15% ± 5% at about 20 keV to 2% ± 5% at about 40?keV. However, according to the manufacturer, the addition of 7.5% Si as SiO{sub 2} adversely affected the viscosity of the active fluid and therefore affected the potential use in commercial machine coating. The latest commercial EBT3 film model with 7% Al as Al{sub 2}O{sub 3} shows an overall improvement in S{sub AD,} {sub W}(Q) compared to previous commercial EBT3 films. It shows under response at all energies <100 keV, varying from 20% ± 4% at 20 keV to 6% ± 4% at 40?keV. Conclusions: The energy response of films in the energy range <100 keV can be improved by adjusting the active layer chemical composition. Removing bromine eliminated the over response at about 40?keV. The under response at energies ?30 keV is improved by adding 7% Al to the active layer in the latest commercial EBT3 film models.

Bekerat, H., E-mail: hamed.bekerat@mail.mcgill.ca; Devic, S.; DeBlois, F. [Medical Physics Unit, McGill University, Montréal, Québec H3G 1A4, Canada and Department of Radiation Oncology, Jewish General Hospital, Montréal, Québec H3T 1E2 (Canada)] [Medical Physics Unit, McGill University, Montréal, Québec H3G 1A4, Canada and Department of Radiation Oncology, Jewish General Hospital, Montréal, Québec H3T 1E2 (Canada); Singh, K.; Sarfehnia, A.; Seuntjens, J. [Medical Physics Unit, McGill University, Montréal, Québec H3G 1A4 (Canada)] [Medical Physics Unit, McGill University, Montréal, Québec H3G 1A4 (Canada); Shih, Shelley; Yu, Xiang; Lewis, D. [Ashland Specialty Ingredients, 1361 Alps Road, Wayne, New Jersey 07470 (United States)] [Ashland Specialty Ingredients, 1361 Alps Road, Wayne, New Jersey 07470 (United States)

2014-02-15

155

Nucl. Instr. Meth. Phys. Res. B., Accepted for publication (1995). Molecular dynamics simulation of ion ranges at keV energies  

E-print Network

Nucl. Instr. Meth. Phys. Res. B., Accepted for publication (1995). Molecular dynamics simulation In molecular dynamics simulations the time evolution of a system of atoms is calculated by solving molecular dynamics method for calculating ion ranges and deposited energies in the recoil energy region 100

Nordlund, Kai

156

The PLATO 2.0 Mission  

E-print Network

PLATO 2.0 is a mission candidate for ESA's M3 launch opportunity (2022/24). It addresses fundamental questions such as: How do planetary systems form and evolve? Are there other systems with planets like ours, able to develop life? The PLATO 2.0 instrument consists of 34 small aperture telescopes providing a wide field-of-view and a large photometric magnitude range. It targets bright 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 stars <=11mag 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 foreseen baseline observing strategy includes two long pointings (2-3 years) to detect and bulk characterize planets reaching into t...

Rauer, H; Aerts, C; Appourchaux, T; Benz, W; Brandeker, A; Christensen-Dalsgaard, J; Deleuil, M; Gizon, L; Güdel, M; Janot-Pacheco, E; Mas-Hesse, M; Pagano, I; Piotto, G; Pollacco, D; Santos, N C; Smith, A; -C., J; Suárez,; Szabó, R; Udry, S; Adibekyan, V; Alibert, Y; Almenara, J -M; Amaro-Seoane, P; Eiff, M Ammler-von; Antonello, E; Ball, W; Barnes, S; Baudin, F; Belkacem, K; Bergemann, M; Birch, A; 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; Csizmadia, Sz; Cunha, M; Damasso, M; Davies, M B; Deeg, H J; Fialho, F de Oliveira; DÍaz, R F; Dreizler, S; Dreyer, C; Eggenberger, P; Ehrenreich, D; Eigmüller, P; Erikson, A; Farmer, R; Feltzing, S; Figueira, P; Forveille, T; Fridlund, M; García, R; Giuffrida, G; Godolt, M; da Silva, J Gomes; Goupil, M -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; 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; 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; Solanki, S K; Salmon, S; Santerne, A; Schneider, J; Schou, J; Schuh, S; Schunker, H; Silva-Valio, A; Silvotti, R; Skillen, I; Snellen, I; Sohl, F; Sousa, A S; Sozzetti, A; Stello, D; Strassmeier, K G; Švanda, M; Szabó, G 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

2013-01-01

157

Correlative multielectron processes in K-shell photoionization of Ca, Ti and V in the energy range of 8-35 keV  

Microsoft Academic Search

The Kalpha satellite spectra arising from the correlative multielectron processes accompanying K-shell photoionization of Ca, Ti and V were measured using a broad range crystal spectrometer. Multiconfiguration Dirac-Fock calculations were performed to interpret the observed x-ray energies and the spectral line shape. The calculations agree fairly well with the experimental results. The variation of the Kalpha L1 satellite and the

Masaki Oura; Hitoshi Yamaoka; Kiyoshi Kawatsura; Katsumi Takahiro; Naoki Takeshima; Yaming Zou; Roger Hutton; Shin Ito; Yohko Awaya; Mititaka Terasawa; Tsuguhisa Sekioka; Takeshi Mukoyama

2002-01-01

158

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

SciTech Connect

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.

Castleton, Karl J.; Meyer, Philip D.

2009-06-17

159

Cross-field Diffusion of Energetic (100 keV to 2 MeV) Protons in Interplanetary Space  

NASA Astrophysics Data System (ADS)

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

da Costa, Edio, Jr.; Tsurutani, Bruce T.; Virgínia Alves, Maria; Echer, Ezequiel; Lakhina, Gurbax S.

2013-12-01

160

Ultra-thin curved transmission crystals for high resolving power (up to E/?E = 6300) x-ray spectroscopy in the 6-13??keV energy range.  

PubMed

Ultra-thin curved transmission crystals operating in the Cauchois spectrometer geometry were evaluated for the purpose of achieving high spectral resolution in the 6-13 keV x-ray energy range. The crystals were silicon (111) and sapphire R-cut wafers, each 18 ?m thick, and a silicon (100) wafer of 50-?m thickness. The W L?1 spectral line at 8.398 keV from a laboratory source was used to evaluate the resolution. The highest crystal resolving power, E/?E=6300, was achieved by diffraction from the (33-1) planes of the Si(100) wafer that was cylindrically bent to a radius of curvature of 254 mm, where the (33-1) planes have an asymmetric angle of 13.26° from the normal of the crystal surface facing the x-ray source. This work demonstrates the ability to measure highly resolved line shapes of the K transitions of the elements Fe through Kr and the L transitions of the elements Gd through Th using a relatively compact spectrometer optical system and readily available thin commercial wafers. The intended application is as a diagnostic of laser-produced plasmas where the presence of multiple charged states and broadenings from high temperature and density requires high-resolution methods that are robust in a noisy source environment. PMID:25503010

Seely, John F; Hudson, Lawrence T; Glover, Jack L; Henins, Albert; Pereira, Nino

2014-12-15

161

DISFRAC Version 2.0 Users Guide  

SciTech Connect

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.

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

2013-01-01

162

Thermal kinetics and short range order parameters of Se80X20 (X = Te, Sb) binary glasses  

NASA Astrophysics Data System (ADS)

Bulk Se80Te20 and Se80Sb20 glasses were prepared using the melt-quench technique. Differential scanning calorimetry (DSC) curves measured at different heating rates (5 K/min? ??50 K/min) and X-ray diffraction (XRD) are used to characterize the as-quenched specimens. Based on the obtained results, the activation energy of glass transition and the activation energy of crystallization ( E g, E c) of the Se80Te20 glass are (137.5, 105.1 kJ/mol) higher than the corresponding values of the Se80Sb20 glass (106.8, 71.2 kJ/mol). An integer n value ( n=2) of the Se80Te20 glass indicates that only one crystallization mechanism is occurring while a non-integer exponent ( n=1.79) in the Se80Sb20 glass means that two mechanisms are working simultaneously during the amorphous-crystalline transformations. The total structure factor, S( K), indicates the presence of the short-range order (SRO) and the absence of the medium-range order (MRO) inside the as-quenched alloys. In an opposite way to the activation energies, the values of the first peak position and the total coordination number ( r 1, ? 1), obtained from a Gaussian fit of the radial distribution function, of the Se80Te20 glass are (2.42 nm, 1.99 atom) lower than the corresponding values (2.55 nm, 2.36 atom) of the Se80Sb20 specimens.

Moharram, A. H.; Abu El-Oyoun, M.; Abdel-Baset, A. M.

2014-06-01

163

THE ORIGIN OF THE 6.4 keV LINE EMISSION AND H{sub 2} IONIZATION IN THE DIFFUSE MOLECULAR GAS OF THE GALACTIC CENTER REGION  

SciTech Connect

We investigate the origin of the diffuse 6.4 keV line emission recently detected by Suzaku and the source of H{sub 2} ionization in the diffuse molecular gas of the Galactic center (GC) region. We show that Fe atoms and H{sub 2} molecules in the diffuse interstellar medium of the GC are not ionized by the same particles. The Fe atoms are most likely ionized by X-ray photons emitted by Sgr A* during a previous period of flaring activity of the supermassive black hole. The measured longitudinal intensity distribution of the diffuse 6.4 keV line emission is best explained if the past activity of Sgr A* lasted at least several hundred years and released a mean 2-100 keV luminosity {approx}> 10{sup 38} erg s{sup -1}. The H{sub 2} molecules of the diffuse gas cannot be ionized by photons from Sgr A*, because soft photons are strongly absorbed in the interstellar gas around the central black hole. The molecular hydrogen in the GC region is most likely ionized by low-energy cosmic rays, probably protons rather than electrons, whose contribution into the diffuse 6.4 keV line emission is negligible.

Dogiel, V. A.; Chernyshov, D. O. [I. E. Tamm Theoretical Physics Division of P. N. Lebedev Institute of Physics, Leninskii pr. 53, 119991 Moscow (Russian Federation); Tatischeff, V. [Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, IN2P3/CNRS and Univ Paris-Sud, F-91405 Orsay Campus (France); Cheng, K.-S. [Department of Physics, University of Hong Kong, Pokfulam Road, Hong Kong (Hong Kong); Terrier, R. [Astroparticule et Cosmologie, Universite Paris7/CNRS/CEA, Batiment Condorcet, F-75013 Paris (France)

2013-07-10

164

Properties of phantom tissuelike polymethylpentene in the frequency range 20-70 MHZ.  

PubMed

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

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

2011-08-01

165

PYRAMID SERVINGS SEARCH VERSION 2.0  

Technology Transfer Automated Retrieval System (TEKTRAN)

This search tool has been updated to display data from the Pyramid Servings Database for USDA Survey Food Codes Version 2.0. Pyramid Servings Search Version 2.0 is a simple, intuitive and an effective instrument for viewing information on the number of Pyramid Servings assigned to foods used to pro...

166

Trust, Voice, and Library 2.0  

ERIC Educational Resources Information Center

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.

Watkins, Candice

2009-01-01

167

Student Inquiry and Web 2.0  

ERIC Educational Resources Information Center

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…

Berger, Pam

2010-01-01

168

Python Reference Manual Release 2.0  

E-print Network

Python Reference Manual Release 2.0 Guido van Rossum Fred L. Drake, Jr., editor October 16, 2000 BeOpen PythonLabs E­mail: python­docs@python.org #12; BEOPEN.COM TERMS AND CONDITIONS FOR PYTHON 2.0 BEOPEN PYTHON OPEN SOURCE LICENSE AGREEMENT VERSION 1 1. This LICENSE AGREEMENT is between BeOpen.com (``Be

Fischer, Charles N.

169

Python Reference Manual Release 2.0  

E-print Network

Python Reference Manual Release 2.0 Guido van Rossum Fred L. Drake, Jr., editor October 16, 2000 BeOpen PythonLabs E-mail: python-docs@python.org #12;BEOPEN.COM TERMS AND CONDITIONS FOR PYTHON 2.0 BEOPEN PYTHON OPEN SOURCE LICENSE AGREEMENT VERSION 1 1. This LICENSE AGREEMENT is between BeOpen.com ("Be

Fischer, Charles N.

170

Python Tutorial Release 2.0  

E-print Network

Python Tutorial Release 2.0 Guido van Rossum Fred L. Drake, Jr., editor October 16, 2000 BeOpen PythonLabs E­mail: python­docs@python.org #12; BEOPEN.COM TERMS AND CONDITIONS FOR PYTHON 2.0 BEOPEN PYTHON OPEN SOURCE LICENSE AGREEMENT VERSION 1 1. This LICENSE AGREEMENT is between BeOpen.com (``Be

Fischer, Charles N.

171

Python Tutorial Release 2.0  

E-print Network

Python Tutorial Release 2.0 Guido van Rossum Fred L. Drake, Jr., editor October 16, 2000 BeOpen PythonLabs E-mail: python-docs@python.org #12;BEOPEN.COM TERMS AND CONDITIONS FOR PYTHON 2.0 BEOPEN PYTHON OPEN SOURCE LICENSE AGREEMENT VERSION 1 1. This LICENSE AGREEMENT is between BeOpen.com ("Be

Fischer, Charles N.

172

The dissociation of 13CH and 12CH 2 molecules in He and N 2 at beam energies of 80-250 keV and possible implications for radiocarbon mass spectrometry  

NASA Astrophysics Data System (ADS)

Isotopic ratios of 14C at natural levels can be efficiently measured with accelerator mass spectrometry (AMS). In compact AMS systems, 13CH and 12CH 2 molecular interferences are destroyed in collisions with the stripper gas, a process which can be described by dissociation cross sections. These dissociation cross sections determine the gas areal density required for sufficient attenuation of the interfering molecular beams, and are therefore key parameters in the effort to further reduce the terminal voltage and thus the size of the AMS system. We measured the dissociation cross sections of 13CH and 12CH 2 in N 2 and He in the energy range of 80-250 keV. In N 2, cross sections were constant for energies above 100 keV with average values per molecule of (8.1 ± 0.4) × 10 -16 cm 2 for 13CH and (9.5 ± 0.5) × 10 -16 cm 2 for 12CH 2. In He, cross sections were constant over the full measured range of 80-150 keV with average values of (4.2 ± 0.3) × 10 - 16 cm 2 and (4.8 ± 0.4) × 10 -16 cm 2, respectively. A considerable reduction of the terminal voltage from the currently used 200 kV while using N 2 for 13CH and 12CH 2 molecule dissociation is not possible: the required N 2 areal densities of ˜1.4 ?g/cm 2, consequential angular straggling and a decreasing 1+ charge state fraction would reduce the ion beam transmission too much. This is not the case for He: sufficient molecule dissociation can be obtained with gas densities of ˜0.4 ?g/cm 2, for which angular straggling is relatively small. In addition, the 1+ charge state fraction still increases at lower stripping energies. Thus, the usage of He for stripping and molecule dissociation might allow the development of even smaller 14C-AMS systems than available today.

Schulze-König, T.; Seiler, M.; Suter, M.; Wacker, L.; Synal, H.-A.

2011-01-01

173

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

NASA Technical Reports Server (NTRS)

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.

Kahler, S.; Lin, R. P.

1994-01-01

174

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)

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.

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

2011-05-01

175

Definition of Health 2.0 and Medicine 2.0: A Systematic Review  

PubMed Central

Background During the last decade, the Internet has become increasingly popular and is now an important part of our daily life. When new “Web 2.0” technologies are used in health care, the terms “Health 2.0" or "Medicine 2.0” may be used. Objective The objective was to identify unique definitions of Health 2.0/Medicine 2.0 and recurrent topics within the definitions. Methods A systematic literature review of electronic databases (PubMed, Scopus, CINAHL) and gray literature on the Internet using the search engines Google, Bing, and Yahoo was performed to find unique definitions of Health 2.0/Medicine 2.0. We assessed all literature, extracted unique definitions, and selected recurrent topics by using the constant comparison method. Results We found a total of 1937 articles, 533 in scientific databases and 1404 in the gray literature. We selected 46 unique definitions for further analysis and identified 7 main topics. Conclusions Health 2.0/Medicine 2.0 are still developing areas. Many articles concerning this subject were found, primarily on the Internet. However, there is still no general consensus regarding the definition of Health 2.0/Medicine 2.0. We hope that this study will contribute to building the concept of Health 2.0/Medicine 2.0 and facilitate discussion and further research. PMID:20542857

Engelen, Lucien JLPG; Berben, Sivera AA; Schoonhoven, Lisette

2010-01-01

176

First X-ray CCD Observations of the Soft X-ray Background from 0.2 to 10 keV  

NASA Astrophysics Data System (ADS)

Preliminary results of the first X-ray CCD observations of the X-ray background between 0.2 and 10 keV are presented. Data were obtained from individual sounding rocket flights on May 22, 1995 from White Sands, New Mexico and on October 25, 1995 from Woomera, Australia. The target for the second flight was a bright region of the soft X-ray background centered at 0 degrees longitude and -15 degrees latitude in galactic coordinates. Covering approximately 1800 square degrees, this feature dominates all-sky surveys below the galactic plane from 0.5 to 1.5 keV. These data will be compared with data from a dim region of the X-ray background in the constellation Draco, obtained on the first flight. The detector for these flights was a thinned gate CCD built by EEV and designed to maximize X-ray response below 0.75 keV without adopting a backside illumination scheme. Improved quantum efficiency over conventional X-ray CCDs above 1 keV was also achieved due to the high resistivity ( 1500 ohm-cm) of this device. This type of CCD will be flown on three sounding rocket flights prior to being launched aboard the CUBIC experiment in November 1996. Similar devices are also scheduled to be launched on Leicester University's Spectrum X/JET-X and XMM/EPIC instruments.

Mendenhall, Jeffrey A.; Burrows, David N.; Cawley, Laura

1996-05-01

177

Vector correlations in dissociative photoionization of O2 in the 20-28 eV range. II. Polar and azimuthal dependence of the molecular frame photoelectron angular distribution  

NASA Astrophysics Data System (ADS)

A combined experimental and theoretical study of the polar and azimuthal dependence of the molecular frame photoelectron angular distributions (MFPADs) for inner-valence-shell photoionization of the O2 molecule into the O2+(B 2Sigmag-,3 2Piu,c 4Sigmau)- states is reported. The measured MFPADs, for each orientation of the molecular axis with respect to the linear polarization of the synchrotron radiation, are derived from the spatial analysis of the (VO+,Ve),P vector correlation, where the nascent ion and electron velocity vectors VO+ and Ve are determined for each dissociative photoionization (DPI) event using imaging and time of flight resolved coincidence technique as described in the companion paper of this series [J. Chem. Phys. 114, 6605 (2001)]. Expressed in the general form of four FLN(thetae) functions which contain all the dynamical information about the photoionization processes, they are compared with the MFPADs computed using the multichannel Schwinger configuration interaction method. A very satisfactory agreement is found. When the lifetime of the O2+ ionic states is a significant fraction of the rotational period, the rotational motion of the molecule is included in the quantal derivation of the MFPADs. Measured MFPADs are also reported for the additional DPI process identified in Paper I, and for DPI involving the excitation of the neutral (3 2Pi]u,4s[sigmag) Rydberg state.

Lafosse, A.; Brenot, J. C.; Guyon, P. M.; Houver, J. C.; Golovin, A. V.; Lebech, M.; Dowek, D.; Lin, P.; Lucchese, R. R.

2002-11-01

178

Carbon Capture (Carbon Cycle 2.0)  

SciTech Connect

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/

Smit, Berend

2010-02-03

179

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

SciTech Connect

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

Raut, U.; Baragiola, R. A. [Laboratory for Atomic and Surface Physics, University of Virginia, Thornton Hall B103, Charlottesville, VA 22904 (United States)

2013-07-20

180

LSST Science Book, Version 2.0  

E-print Network

A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of the exciting science opportunities of the next decade. The Large Synoptic Survey Telescope (LSST) will have an effective aperture of 6.7 meters and an imaging camera with field of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over 20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a total point-source depth of r~27.5. The LSST Science Book describes the basic parameters of the LSST hardware, software, and observing plans. The book discusses educational and outreach opportunities, then goes on to describe a broad range of science that LSST will revolutionize: mapping the inner and outer Solar System, stellar populations in the Milky Way and nearby galaxies, the structure of the Milky Way disk and halo and other objects in the Local Volume, transient and variable object...

Allison, Julius; Andrew, John R; Angel, J Roger P; Armus, Lee; Arnett, David; Asztalos, S J; Axelrod, Tim S; Bailey, Stephen; Ballantyne, D R; Bankert, Justin R; Barkhouse, Wayne A; Barr, Jeffrey D; Barrientos, L Felipe; Barth, Aaron J; Bartlett, James G; Becker, Andrew C; Becla, Jacek; Beers, Timothy C; Bernstein, Joseph P; Biswas, Rahul; Blanton, Michael R; Bloom, Joshua S; Bochanski, John J; Boeshaar, Pat; Borne, Kirk D; Bradac, Marusa; Brandt, W N; Bridge, Carrie R; Brown, Michael E; Brunner, Robert J; Bullock, James S; Burgasser, Adam J; Burge, James H; Burke, David L; Cargile, Phillip A; Chandrasekharan, Srinivasan; Chartas, George; Chesley, Steven R; Chu, You-Hua; Cinabro, David; Claire, Mark W; Claver, Charles F; Clowe, Douglas; Connolly, A J; Cook, Kem H; Cooke, Jeff; Cooray, Asantha; Covey, Kevin R; Culliton, Christopher S; de Jong, Roelof; de Vries, Willem H; Debattista, Victor P; Delgado, Francisco; Dell'Antonio, Ian P; Dhital, Saurav; Di Stefano, Rosanne; Dickinson, Mark; Dilday, Benjamin; Djorgovski, S G; Dobler, Gregory; Donalek, Ciro; Dubois-Felsmann, Gregory; Durech, Josef; Eliasdottir, Ardis; Eracleous, Michael; Eyer, Laurent; Falco, Emilio E; Fan, Xiaohui; Fassnacht, Christopher D; Ferguson, Harry C; Fernandez, Yanga R; Fields, Brian D; Finkbeiner, Douglas; Figueroa, Eduardo E; Fox, Derek B; Francke, Harold; Frank, James S; Frieman, Josh; Fromenteau, Sebastien; Furqan, Muhammad; Galaz, Gaspar; Gal-Yam, A; Garnavich, Peter; Gawiser, Eric; Geary, John; Gee, Perry; Gibson, Robert R; Gilmore, Kirk; Grace, Emily A; Green, Richard F; Gressler, William J; Grillmair, Carl J; Habib, Salman; Haggerty, J S; Hamuy, Mario; Harris, Alan W; Hawley, Suzanne L; Heavens, Alan F; Hebb, Leslie; Henry, Todd J; Hileman, Edward; Hilton, Eric J; Hoadley, Keri; Holberg, J B; Holman, Matt J; Howell, Steve B; Infante, Leopoldo; Ivezic, Zeljko; Jacoby, Suzanne H; Jain, Bhuvnesh; R,; Jedicke,; Jee, M James; Jernigan, J Garrett; Jha, Saurabh W; Johnston, Kathryn V; Jones, R Lynne; Juric, Mario; Kaasalainen, Mikko; Styliani,; Kafka,; Kahn, Steven M; Kaib, Nathan A; Kalirai, Jason; Kantor, Jeff; Kasliwal, Mansi M; Keeton, Charles R; Kessler, Richard; Knezevic, Zoran; Kowalski, Adam; Krabbendam, Victor L; Krughoff, K Simon; Kulkarni, Shrinivas; Kuhlman, Stephen; Lacy, Mark; Lepine, Sebastien; Liang, Ming; Lien, Amy; Lira, Paulina; Long, Knox S; Lorenz, Suzanne; Lotz, Jennifer M; Lupton, R H; Lutz, Julie; Macri, Lucas M; Mahabal, Ashish A; Mandelbaum, Rachel; Marshall, Phil; May, Morgan; McGehee, Peregrine M; Meadows, Brian T; Meert, Alan; Milani, Andrea; Miller, Christopher J; Miller, Michelle; Mills, David; Minniti, Dante; Monet, David; Mukadam, Anjum S; Nakar, Ehud; Neill, Douglas R; Newman, Jeffrey A; Nikolaev, Sergei; Nordby, Martin; O'Connor, Paul; Oguri, Masamune; Oliver, John; Olivier, Scot S; Olsen, Julia K; Olsen, Knut; Olszewski, Edward W; Oluseyi, Hakeem; Padilla, Nelson D; Parker, Alex; Pepper, Joshua; Peterson, John R; Petry, Catherine; Pinto, Philip A; Pizagno, James L; Popescu, Bogdan; Prsa, Andrej; Radcka, Veljko; Raddick, M Jordan; Rasmussen, Andrew; Rau, Arne; Rho, Jeonghee; Rhoads, James E; Richards, Gordon T; Ridgway, Stephen T; Robertson, Brant E; Roskar, Rok; Saha, Abhijit; Sarajedini, Ata; Scannapieco, Evan; Schalk, Terry; Schindler, Rafe; Schmidt, Samuel; Schmidt, Sarah; Schneider, Donald P; Schumacher, German; Scranton, Ryan; Sebag, Jacques; Seppala, Lynn G; Shemmer, Ohad; Simon, Joshua D; Sivertz, M; Smith, Howard A; Smith, J Allyn; Smith, Nathan; Spitz, Anna H; Stanford, Adam; Stassun, Keivan G; Strader, Jay; Strauss, Michael A; Stubbs, Christopher W; Sweeney, Donald W; Szalay, Alex; Szkody, Paula; Takada, Masahiro; Thorman, Paul; Trilling, David E; Trimble, Virginia; Tyson, Anthony; Van Berg, Richard; Berk, Daniel Vanden; VanderPlas, Jake; Verde, Licia; Vrsnak, Bojan; Walkowicz, Lucianne M; Wandelt, Benjamin D; Wang, Sheng; Wang, Yun; Warner, Michael; Wechsler, Risa H; West, Andrew A; Wiecha, Oliver; Williams, Benjamin F; Willman, Beth; Wittman, David; Wolff, Sidney C; Wood-Vasey, W Michael; Wozniak, Przemek; Young, Patrick; Zentner, Andrew; Zhan, Hu

2009-01-01

181

Design and Implementation of Web2.0Based XCU2.0  

Microsoft Academic Search

In this paper, we firstly introduce the emergence, characteristics and the concept of Web2.0. Then we present the concept system's design and construction of the Xuchang University (here we called it XCU2.0). We emphasize on the design idea and the system frame of XCU2.0, and we present how to integrate part of the applications through Web service technology in XCU2.0.

Ling Zhang; Hongchao Xu; Haina Hu

2009-01-01

182

The PLATO 2.0 Mission  

NASA Astrophysics Data System (ADS)

PLATO 2.0 is the M class mission selected by ESA for its M3 launch slot in the framework of the Cosmic Vision 2015-2025 program. The main goals of PLATO 2.0 are the detection of terrestrial exoplanets in the habitable zone of solar-type stars and the characterization of their bulk properties needed to determine their habitability. Moreover, PLATO 2.0 will be key in understanding the formation, architecture, and evolution of planetary systems thanks to a thorough inventory of the physical properties of thousands of rocky, icy, and gaseous giant planets. We will illustrate the PLATO 2.0 science goals, how the instrument is conceived to fulfil the science requirements, and how the project is organized to implement the instrument, plan the observations, and exploit the resulting data.

Pagano, I.; Rauer, H.; Aerts, C.; Appourchaux, T.; Benz, W.; Brandeker, A.; Christensen-Dalsgaard, J.; Deleuil, M.; Gizon, L.; Goupil, M.-J.; Guedel, M.; Heras, A.; Janot-Pacheco, E.; Mas-Hesse, M.; Piotto, G.; Pollaco, D.; Ragazzoni, R.; Santos, N. C.; Smith, A.; Suarez, J. C.; Szabo, R.; Udry, S.

2014-04-01

183

Business 2.0 Web Guide  

NSDL National Science Digital Library

According to one of its own brochures, "Business 2.0 is the essential tool for navigating today's relentlessly changing marketplace, particularly as it's driven by the Internet and other technologies." In both print and electronic versions, Business 2.0 does cover an incredible amount of ground, including day-to-day and month-to-month information and offering extensive subject lists of its material, broken down by general subjects -- from management and marketing to Enron and the Internet. Not only clearly in touch with today's business world, Business 2.0 promises to put its readers in touch with it through company links, as well as through straightforward contact lists. While Business 2.0 is open for anyone's consultation, registered readers are granted greater access privileges to archived and premium content.

2001-01-01

184

Method for semigroups Version 2.0  

E-print Network

Semigroups Method for semigroups Version 2.0 J. D. Mitchell James East Attila Egri-Nagy Julius in improving the efficiency of the package. James East, Attila Egri-Nagy, and Markus Pfeiffer contributed

Mitchell, Janes D.

185

30 CFR 20.2 - Definitions.  

Code of Federal Regulations, 2010 CFR

... TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MINE LAMPS OTHER THAN STANDARD CAP LAMPS § 20.2 Definitions...explosions of methane-air mixtures without damage to itself or discharge of flame and without ignition of surrounding explosive...

2010-07-01

186

The PLATO 2.0 mission  

NASA Astrophysics Data System (ADS)

PLATO 2.0 is the next generation space-based survey for transiting extrasolar planets and is proposed to ESA as a candidate for the M3 slot within the ESA Cosmic Vision 2015-2025 program. Its main objectives are the detection of Earth Analogue systems around bright stars, and to reveal the interior structure of planets and their host stars. We will present here the expected scientific impact of the PLATO 2.0 mission.

Rauer, H.

2013-09-01

187

Web Lectures and Web 2.0  

Microsoft Academic Search

At many universities, web lectures have become an integral part of the e-learning portfolio over the last few years. While many aspects of the technology involved, like automatic recording techniques or innovative interfaces for replay, have evolved at a rapid pace, web lecturing has been independent of other important developments such as Web 2.0. Web 2.0 is an emerging trend

Markus Ketterl; Robert Mertens; Oliver Vornberger

2008-01-01

188

Lost in Web 2.0 Cyberspace?  

ERIC Educational Resources Information Center

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

Fallon, Julia

2008-01-01

189

Frameworks für das Web2.0  

Microsoft Academic Search

Zusammenfassung  Gngige Web-Frameworks sind vielschichtig und erfordern einen hohen Lern- als auch Konfigurationsaufwand. Web2.0-Frameworks\\u000a dagegen erheben den Anspruch der schnelleren und einfacheren Entwicklung. Exemplarisch wird in diesem Schlagwortbeitrag das\\u000a neuartige Web2.0-Framework Ruby on Rails (RoR) vorgestellt. RoR versucht die einfache Unmittelbarkeit von PHP mit der Architektur,\\u000a Reinheit und Qualitt von Java zu verbinden.

Michael Bächle; Paul Kirchberg

2007-01-01

190

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

SciTech Connect

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/

Cheng, Robert K; Meza, Juan

2010-02-03

191

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

ScienceCinema

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/

Cheng, Robert K; Meza, Juan

2011-06-08

192

Quantifying sea surface temperature ranges of the Arabian Sea for the past 20 000 years  

NASA Astrophysics Data System (ADS)

The oxygen isotopic composition of planktonic foraminifera tests is one of the widest used geochemical tools to reconstruct past changes of physical parameters of the upper ocean. It is common practice to analyze multiple individuals from a mono-specific population and assume that the outcome reflects a mean value of the environmental conditions during calcification of the analyzed individuals. Here we present the oxygen isotope composition of individual specimens of the surface dwelling species Globigerinoides ruber and Globigerina bulloides from sediment cores in the Western Arabian Sea off Somalia inferred as indicators of past seasonal ranges in temperature. Combining the ?18O measurements of individual specimens to obtain temperature ranges with Mg/Ca based mean calcification temperatures allows us to reconstruct temperature extrema. Our results indicate that over the past 20 kyrs the seasonal temperature range has fluctuated from its present value of 16 °C (14 to 30 °C), to 11 °C (15 to 26 °C) during the LGM. The range during the LGM suggests that the maximum temperature was lower, whilst minimum temperature remained approximately constant.

Ganssen, G.; Peeters, F.; Metcalfe, B.; Anand, P.; Jung, S.; Kroon, D.; Brummer, G.-J.

2010-12-01

193

Global Impacts (Carbon Cycle 2.0)  

ScienceCinema

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/

Gadgil, Ashok [EETD and UC Berkeley

2011-06-08

194

Global Impacts (Carbon Cycle 2.0)  

SciTech Connect

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/

Gadgil, Ashok [EETD and UC Berkeley] [EETD and UC Berkeley

2010-02-02

195

defstructure for ACL2 Version 2.0 Bishop Brock  

E-print Network

defstructure for ACL2 Version 2.0 Bishop Brock Computational Logic, Inc. brock@cli.com December 1, 1997 Abstract This article documents the defstructure macro, a facility provided by the ACL2 book acl2-sources/books/data-structures/structures.lisp as distributed with Release 2.0 of ACL2. defstructure

Page, Rex L.

196

Quantifying sea surface temperature ranges of the Arabian Sea for the past 20 000 years  

NASA Astrophysics Data System (ADS)

The oxygen isotopic composition of planktonic foraminifera tests is one of the widest used geochemical tools to reconstruct past changes of physical parameters of the upper ocean. It is common practice to analyze multiple individuals from a mono-specific population and assume that the outcome reflects a mean value of the environmental conditions during calcification of the analyzed individuals. Here we present the oxygen isotope composition of individual specimens of the surface-dwelling species Globigerinoides ruber and Globigerina bulloides from sediment cores in the Western Arabian Sea off Somalia, inferred as indicators of past seasonal ranges in temperature. Combining the ?18O measurements of individual specimens to obtain temperature ranges with Mg/Ca based mean calcification temperatures allows us to reconstruct temperature extrema. Our results indicate that over the past 20 kyr the seasonal temperature range has fluctuated from its present value of 16 °C to mean values of 13 °C and 11 °C for the Holocene and LGM, respectively. The data for the LGM suggest that the maximum temperature was lower, whilst minimum temperature remained approximately constant. The rather minor variability in lowest summer temperatures during the LGM suggests roughly constant summer monsoon intensity, while upwelling-induced productivity was lowered.

Ganssen, G. M.; Peeters, F. J. C.; Metcalfe, B.; Anand, P.; Jung, S. J. A.; Kroon, D.; Brummer, G.-J. A.

2011-12-01

197

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

PubMed

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

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

2012-04-01

198

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

NASA Astrophysics Data System (ADS)

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

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

2015-01-01

199

Version 2.0 User's Guide  

E-print Network

Constructors 47 TestBenches 49 CHAPTER 4 Processes 53 Basics 54 Method Process 54 Thread Processes 56 Clocked Thread Process 59 Wait Until 63 Watching 64 Local Watching 67 CHAPTER 5 Ports and Signals 71 Reading 77 Signal Binding 78 #12;SystemC 2.0 User's Guide v Clocks 80 CHAPTER 6 Data Types 83 Type sc_bit 84

Silvano, Cristina

200

Wireshark Lab: DNS Version: 2.0  

E-print Network

Wireshark Lab: DNS Version: 2.0 © 2007 J.F. Kurose, K.W. Ross. All Rights Reserved Computer System (DNS) translates hostnames to IP addresses, fulfilling a critical role in the Internet infrastructure. In this lab, we'll take a closer look at the client side of DNS. Recall that the client's role

Di Mauro, Nicola

201

Information in a 2.0 World  

E-print Network

Information Literacy Assessment in a 2.0 World: Changes & Challenges Megan Oakleaf, MLS, PhD www in Information Literacy Land? #12;© Oakleaf 2010 What are good artifacts of student learning for assessment · blogs · wikis Oakleaf, Megan. "Writing Information Literacy Assessment Plans: A Guide to Best Practice

Oakleaf, Megan

202

Three Challenges of Web 2.0  

ERIC Educational Resources Information Center

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

Reeves, Douglas B.

2009-01-01

203

RAS Pathway v2.0  

Cancer.gov

Posted: January 13, 2015 RAS Pathway v2.0 January 13, 2015 by Frank McCormick Enlarge The diagram shows 227 genes arranged in 65 groups containing one to 29 genes per group.  The proteins represented by gene names in a group are thought to carry

204

COMPONENTVersion 2.0 Tree Comparsion Software  

E-print Network

COMPONENTVersion 2.0 Tree Comparsion Software for Microsoft® WindowsTM User's Guide Roderic D. M NO WARRANTY, EITHER EXPRESSED OR IMPLIED, WITH RESPECT TO THIS SOFTWARE, ITS QUALITY, PERFORMANCE, MERCHANTABILITY, OR FITNESS FOR A PARTICULAR PURPOSE. AS A RESULT, THIS SOFTWARE IS SOLD "AS IS", AND YOU

Page, Roderic

205

Looking for Collection 2.0  

ERIC Educational Resources Information Center

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,…

Buczynski, James A.

2008-01-01

206

Social Participation in Health 2.0  

PubMed Central

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

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

2010-01-01

207

Educational Uses of Web 2.0  

NSDL National Science Digital Library

Educational Uses of Web 2.0 is a presentation that was delivered at the SAME-TEC advanced technological education conference on July 30, 2008 by Mike Qaissaunee and Gordon Synder of NCTT. This presentation covers: blogs, cellphones, webware, mindmapping, video-online meetings, information gathering, ultra-aggregators, bookmarks.

Qaissaunee, Michael; Synder, Gordon

2010-04-14

208

Corso di Formazione Micromedex 2.0  

E-print Network

Pietro Valdoni, Policlinico Umberto I Micromedex 2.0® è un Sistema di Informazione Clinica Computerizzata prescrittori. L'Azienda Umberto I, Policlinico di Roma, in accordo con l'Editore Thomson Reuters di Micromedex V. Erspamer, Sapienza Università di Roma PRGM Tossicologia d'Urgenza e Centro Antiveleni, Umberto I

Di Pillo, Gianni

209

CDM 2.0 (CLIMATOLOGICAL DISPERSION MODEL - VERSION 2.0) USER'S GUIDE  

EPA Science Inventory

CDM-2.0 (Climatological Dispersion Model - Version 2.0) determines longterm (seasonal or annual) quasi-stable pollutant concentrations in rural or urban settings using average emission rates from point and area sources and a joint frequency distribution of wind direction, wind sp...

210

Multipole mixing ratios of the 198 and 177 keV ?-ray transitions in 169Tm  

NASA Astrophysics Data System (ADS)

The multipole mixing ratios for the 198 and 177 keV ?-ray transitions in 169Tm are determined as ?(198)=-6.1+0.4-0.6 and ?(177)=-0.20+0.04-0.03 from new measurements of angular correlation of the 63-198 and 63-177 keV cascades in addition to measurements on the cascades passing through the 118 and 139 keV levels. The present value of ?(198) indicates an almost pure E2 character for the 198 keV ? ray while from earlier measurements an admixture of only 9% E2 was reported for this ? ray. For both the 198 and 177 keV transitions the results do not agree with the conversion electron measurements and indicate that the conversion processes in these transitions are not normal. From time-differential measurement on the 63-198 keV cascade, the relaxation constant ?2=(0.31+/-0.21)×107 sec-1 is obtained using the source in acetic acid solution. The integral attenuation coefficients for the 316 keV level are found to be G2=0.19+/-0.04 in liquid chloride source and G2=0.57+/-0.06 in liquid acetate source.

Dey, C. C.; Sinha, B. K.

1994-01-01

211

MicroSurfer 2.0  

NSDL National Science Digital Library

MicroSurfer 2.0 is Web productivity software that enables faster Internet surfing. This newly release product eliminates backtracking in your browser; allows you to view Web pages without waiting; and allows you to collect, organize, and share links up to 400% faster. The software requiries Windows 95/98/2000/NT/Me/XP, direct or dial-up Internet access, and Microsoft Internet Explorer 4 or higher. MicroSurfer 2.0 edition is free for non-profit organizations and for individual personal use. For businesses, governmental entities, educational institutions, and those interested in a more advanced version of the software, the Plus edition may be purchased from the MicroSurfer online store.

1998-01-01

212

STRANAL-PMC Version 2.0  

NASA Technical Reports Server (NTRS)

Version 2.0 of the Strain Rate Dependent Analysis of Polymer Matrix Composites (STRANAL-PMC) software has been released. A prior version was reported in Analyzing Loads and Strains in Polymer- Matrix Composites (LEW-17227), NASA Tech Briefs, Vol. 26, No. 11 (November 2002), page 36. To recapitulate: Modified versions of constitutive equations of viscoplasticity of metals are used to represent deformation of a polymeric matrix. The equations are applied in a micromechanical approach, proceeding upward from slices of unit cells, through the ply level, to the laminate level. The constitutive equations are integrated in time by a Runge- Kutta technique. To predict the ultimate strength of each composite ply, failure criteria are implemented within the micromechanics. The inputs to STRANAL-PMC are the laminate geometry, properties of the fiber and matrix materials, and applied stress or strain versus time. The outputs are time-dependent stresses and strains at the slice, ply, and laminate levels. The improvements in version 2.0 include more rigorous representation of hydrostatic- stress effects in the matrix, refinement and extension of ply failure models, and capabilities to analyze transverse shear stresses. Version 2.0 can be implemented as a material-model code within transient dynamic finite-element codes.

Goldberg, Robert; Carney, Kelly S.; Binienda, Wieslaw; Chattopadhyay, Aditi

2006-01-01

213

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

SciTech Connect

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/

Bill Collins

2010-02-09

214

Solar Fuels and Carbon Cycle 2.0 (Carbon Cycle 2.0)  

SciTech Connect

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/

Alivisatos, Paul

2010-02-04

215

Solar Fuels and Carbon Cycle 2.0 (Carbon Cycle 2.0)  

ScienceCinema

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/

Alivisatos, Paul

2011-06-03

216

Code Splitting for Network Bound Web 2.0 Applications Benjamin Livshits  

E-print Network

Code Splitting for Network Bound Web 2.0 Applications Benjamin Livshits Microsoft Research Chen Ding, University of Rochester Abstract Modern Web 2.0 applications such as Gmail, Live Maps, My improve the perceived client-side performance for a range of Web 2.0 applications is to per- form

Livshits, Ben

217

The 2-10 keV luminosity function of AGN in the XMM-LSS and XMM-CDFS surveys  

NASA Astrophysics Data System (ADS)

The XMM-Newton LSS and CDFS surveys probe complementary regions of the flux-redshift plane, and together they provide one of the largest samples of AGN available to study their luminosity function (LF), with approx.~2900 objects with 75% redshift completeness. I will present the redshift-dependent 2-10 keV LF, estimated using different methods: a binned LF, a maximum-likelihood fit using the LDDE and LADE models for its evolution, and a Bayesian analysis with the same models. The LDDE model performs better than LADE, but there is space for improvement especially at low-redshift and high-luminosity. For all three methods, the 2-10 keV luminosities have been corrected for absorption taking into account the complete probability distribution of spectral slopes and column densities. Photometric redshifts have been included with their probability distributions. I will show how to include this information in the LF computation. Finally, the LF will be compared to previous determinations and models.

Ranalli, P.; Georgantopoulos, I.; Koulouridis, E.; Comastri, A.

2014-07-01

218

OPAC 2.0: Next generation online library catalogues ride the Web 2.0 wave!  

Microsoft Academic Search

In the fast moving world of technology, we can be sure that things will change, but we can’t predict the next big development. Web 2.0 started as a brainstorming conference on new web applications emerging from the ashes of the internet dot.com collapse in 2001. Web 2.0 includes concepts such as social networking and participation on the internet, user community

Katie Wilson

2007-01-01

219

PHOEBE 2.0 - Where no model has gone before  

NASA Astrophysics Data System (ADS)

phoebe 2.0 is an open source framework bridging the gap between stellar observations and models. It allows to create and fit models simultaneously and consistently to a wide range of observational data such as photometry, spectroscopy, spectrapolarimetry, interferometry and astrometry. To reach the level of precision required by the newest generation of instruments such as Kepler, GAIA and the arrays of large telescopes, the code is set up to handle a wide range of phenomena such as multiplicity, rotation, pulsations and magnetic fields, and to model the involved physics to a new level.

Degroote, P.; Conroy, K.; Hambleton, K.; Bloemen, S.; Pablo, H.; Giammarco, J.; Prša, A.

2013-02-01

220

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

NASA Astrophysics Data System (ADS)

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

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

1981-05-01

221

UQTk version 2.0 user manual.  

SciTech Connect

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.

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

2013-10-01

222

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

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

223

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

NASA Technical Reports Server (NTRS)

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.

Bishop, D. F.

1991-01-01

224

Backside-thinned CCDs for keV electron detection  

NASA Astrophysics Data System (ADS)

This paper presents preliminary results on the performance of n-channel, backside-thinned charge-coupled devices (CCDs) as electron-bombarded-semiconductor (EBS) imagers for the detection of 1-10 keV electrons. The devices exhibit average EBS gains ranging from approximately 50 at 1 keV to >1600 at 10 keV. Device radiation tolerance has been investigated by exposing normally-clocked devices to 6 keV electron doses up to 0.01 Coulombs/cm(superscript 2). Room temperature pre- and post-irradiation results are presented for these key device parameters: full well capacity, dark current, and charge transfer efficiency (CTE). At the maximum dose of 0.01 Coulombs/cm(superscript 2), full well capacity decreases 9% from an initial value of 680,000 e(superscript -), and dark current increases from 2) to approximately 50 nA/cm(superscript 2). There are no measurable changes in large signal CTE up to the maximum dose. Radiation damage at energies other than 6 keV is estimated by measurement of the x-ray generation efficiency of silicon as a function of electron energy. Device stability after temperature cycling has been studied by subjecting packaged devices to vacuum bakes of 24 hours at 300 degree(s)C. Full well, CTE, EBS gain, and output amplifier performance are unchanged after the extended temperature cycle, while dark current decreases slightly by 15%. In summary, these initial results indicate that the CCD can function as both an efficient and robust electron imager.

Ravel, Mihir K.; Reinheimer, Alice L.

1991-07-01

225

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

SciTech Connect

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/

Alivisatos, Paul

2010-02-01

226

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

SciTech Connect

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/

Collins, Bill

2010-02-01

227

Web 2.0 and Critical Information Literacy  

ERIC Educational Resources Information Center

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…

Dunaway, Michelle

2011-01-01

228

Range and longitudinal range straggling with various stopping power formulations for oxygen ions in Si and SiO2  

NASA Astrophysics Data System (ADS)

The results on comparison of different energy-loss formulations as well as calculations of the range and range straggling have been presented for the ion-target system where oxygen ions are incident on amorphous silicon and silicon dioxide targets. Applying stopping-power expressions by Montenegro et al., Öztürk et al., Wang and He, and Gümü and Köksal, we have numerically calculated range and range straggling within a transport-theory formalism. An interesting result is that the Montenegro et al. formula produces results better than its corrected version; the Öztürk et al. relation, despite the range and range straggling calculations indicating that the produced results by using the Öztürk et al. formulation are better than the Montenegro et al. formula when compared with experiment. The results with respect to the range straggling of oxygen ions in silicon dioxide show that the deviation from the experiment for the Öztürk et al. formulation is 42% at 200 keV, being the smallest deviation among the SRIM program and the other techniques.

Kabadayi, Önder; Gümü, Hasan

2005-10-01

229

Range predictions for a CO(2) laser communication system.  

PubMed

Calculations are presented to permit range predictions of a CO(2) laser communication system when attenuation statistics are available. Both TV and digital transmission are considered. In the former case, an AM-FM modulation scheme is used. Direct demodulation is assumed. Examples are given in the use of the results to obtain range probabilities based on reported propagation statistics. PMID:20333019

Waksberg, A

1981-08-01

230

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

PubMed

X-ray absorption spectroscop (XAS) in the intermediate x-ray region (2-6 keV) for dilute biological samples has been limited because of detector/flux limitations and inadequate cryogenic instrumentation. We have designed and constructed a new tailpiece/sample chamber for a commercially available liquid helium cooled cryostat which overcomes difficulties related to low fluorescence signals by using thin window materials and incorporating an internal photodiode detector. With the apparatus, XAS data at the Cl, S, and Ca K edges have been collected on frozen solutions and biological samples at temperatures down to 60 K. A separate chamber has been incorporated for collecting room-temperature spectra of standard compounds (for energy calibration purposes) which prevents contamination of the cryostat chamber and allows the sample to remain undisturbed, both important concerns for studying dilute and radiation-sensitive samples. PMID:25057214

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

2004-01-01

231

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

PubMed Central

X-ray absorption spectroscop (XAS) in the intermediate x-ray region (2–6 keV) for dilute biological samples has been limited because of detector/flux limitations and inadequate cryogenic instrumentation. We have designed and constructed a new tailpiece/sample chamber for a commercially available liquid helium cooled cryostat which overcomes difficulties related to low fluorescence signals by using thin window materials and incorporating an internal photodiode detector. With the apparatus, XAS data at the Cl, S, and Ca K edges have been collected on frozen solutions and biological samples at temperatures down to 60 K. A separate chamber has been incorporated for collecting room-temperature spectra of standard compounds (for energy calibration purposes) which prevents contamination of the cryostat chamber and allows the sample to remain undisturbed, both important concerns for studying dilute and radiation-sensitive samples. PMID:25057214

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

2014-01-01

232

Gordon and Mike's ICT Podcast: Web 2.0 Spawns Office 2.0  

NSDL National Science Digital Library

Gordon and Mike's ICT Podcast offers perspectives on the information and communication technologies (ICT) industries from Gordon Snyder and Mike Qaissaunee. In this podcast, Mike and Gordon discuss how the growing services offered via webware are eliminating the need for locally-installed software, ushering in the era of Office 2.0 with Web 2.0. The running time for the show is 33:08. This podcast is available for direct download in mp3 format from the Libsyn site, or click here to subscribe to the whole series in iTunes.

Qaissaunee, Michael

233

Constraints on 3.55 keV line emission from stacked observations of dwarf spheroidal galaxies  

E-print Network

Several recent works have reported the detection of an unidentified X-ray line at 3.55 keV, which could possibly be attributed to the decay of dark matter (DM) particles in the halos of galaxy clusters and in the M31 galaxy. We analyze all publicly-available XMM-Newton data of dwarf spheroidal galaxies to test the possible DM origin of the line. Dwarf spheroidal galaxies have high mass-to-light ratios and their interstellar medium is not a source of diffuse X-ray emission, thus they are expected to provide the cleanest DM decay line signal. Our analysis shows no evidence for the presence of the line in the stacked spectra of the dwarf galaxies. It excludes the sterile neutrino DM decay origin of the 3.5 keV line reported by Bulbul et al. (2014) at the level of 4.6 sigma under standard assumptions about the Galactic DM column density in the direction of selected dwarf galaxies and at the level of 3.3 sigma assuming minimal Galactic DM column density. As a by-product of our analysis, we provide updated upper limits to the mixing angle of sterile neutrino DM in the mass range between 2 and 20 keV.

D. Malyshev; A. Neronov; D. Eckert

2014-08-15

234

Session 2: Modelling air pollution across a range of scales  

E-print Network

Session 2: Modelling air pollution across a range of scales Ruth Doherty, Massimo Vieno, Ian Mac) EMEP2009 (less complex) Observations Modelling regional air pollution #12;Nested regions: 50 to 5 to 1 km2 O3 concentration (ppb) NO2 concentration (µg m-3) #12;Modelling Urban air pollution Regional

235

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)

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.

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

1986-01-01

236

The r-Java 2.0 code: nuclear physics  

NASA Astrophysics Data System (ADS)

Aims: We present r-Java 2.0, a nucleosynthesis code for open use that performs r-process calculations, along with a suite of other analysis tools. Methods: Equipped with a straightforward graphical user interface, r-Java 2.0 is capable of simulating nuclear statistical equilibrium (NSE), calculating r-process abundances for a wide range of input parameters and astrophysical environments, computing the mass fragmentation from neutron-induced fission and studying individual nucleosynthesis processes. Results: In this paper we discuss enhancements to this version of r-Java, especially the ability to solve the full reaction network. The sophisticated fission methodology incorporated in r-Java 2.0 that includes three fission channels (beta-delayed, neutron-induced, and spontaneous fission), along with computation of the mass fragmentation, is compared to the upper limit on mass fission approximation. The effects of including beta-delayed neutron emission on r-process yield is studied. The role of Coulomb interactions in NSE abundances is shown to be significant, supporting previous findings. A comparative analysis was undertaken during the development of r-Java 2.0 whereby we reproduced the results found in the literature from three other r-process codes. This code is capable of simulating the physical environment of the high-entropy wind around a proto-neutron star, the ejecta from a neutron star merger, or the relativistic ejecta from a quark nova. Likewise the users of r-Java 2.0 are given the freedom to define a custom environment. This software provides a platform for comparing proposed r-process sites.

Kostka, M.; Koning, N.; Shand, Z.; Ouyed, R.; Jaikumar, P.

2014-08-01

237

A system for differential neutron scattering experiments in the energy range from 0.5 to 20 MeV  

E-print Network

A system for differential neutron scattering experiments in the energy range from 0.5 to 20 MeV F scattering cross-section data, scattering experiments were performed using a collimated source of pulsed on a combination of theory and a limited number of experiments. Applications involving particle accelerators

Danon, Yaron

238

Operation Manual for the TA Instruments DSC Q-100 and Q-20: Temperature Range: -90C 400C  

E-print Network

Operation Manual for the TA Instruments DSC Q-100 and Q-20: Temperature Range: -90°C ­ 400°C Sample of the pan and sample and crimp the pan according to instructions from your training. After crimping) if you do not change the sample name with each new sample. Click on the PROCEDURE tab to write your

Alpay, S. Pamir

239

Recent plant studies using Victoria 2.0  

SciTech Connect

VICTORIA 2.0 is a mechanistic computer code designed to analyze fission product behavior within the reactor coolant system (RCS) during a severe nuclear reactor accident. It provides detailed predictions of the release of radioactive and nonradioactive materials from the reactor core and transport and deposition of these materials within the RCS and secondary circuits. These predictions account for the chemical and aerosol processes that affect radionuclide behavior. VICTORIA 2.0 was released in early 1999; a new version VICTORIA 2.1, is now under development. The largest improvements in VICTORIA 2.1 are connected with the thermochemical database, which is being revised and expanded following the recommendations of a peer review. Three risk-significant severe accident sequences have recently been investigated using the VICTORIA 2.0 code. The focus here is on how various chemistry options affect the predictions. Additionally, the VICTORIA predictions are compared with ones made using the MELCOR code. The three sequences are a station blackout in a GE BWR and steam generator tube rupture (SGTR) and pump-seal LOCA sequences in a 3-loop Westinghouse PWR. These sequences cover a range of system pressures, from fully depressurized to full system pressure. The chief results of this study are the fission product fractions that are retained in the core, RCS, secondary, and containment and the fractions that are released into the environment.

BIXLER,NATHAN E.; GASSER,RONALD D.

2000-03-08

240

First observation of ? decay of Pt190 to the first excited level (Eexc=137.2 keV) of Os186  

NASA Astrophysics Data System (ADS)

The ? decays of naturally occurring platinum isotopes, which are accompanied by the emission of ? 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 cm3) during 1815 h. The ? decay of Pt190 to the first excited level of Os186 (J?=2+, Eexc=137.2 keV) has been observed for the first time, with the half-life determined as T1/2=2.6-0.3+0.4(stat.)±0.6(syst.)×1014 yr. The T1/2 limits for the ? decays of other Pt isotopes have been determined at the level of T1/2?1016-1020 yr. These limits have been set for the first time or they are better than those known from earlier experiments.

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

2011-03-01

241

Krox20 hindbrain cis-regulatory landscape: interplay between multiple long-range initiation and autoregulatory elements.  

PubMed

The vertebrate hindbrain is subject to a transient segmentation process leading to the formation of seven or eight metameric territories termed rhombomeres (r). This segmentation provides the basis for the subsequent establishment of hindbrain neuronal organization and participates in the patterning of the neural crest involved in craniofacial development. The zinc-finger gene Krox20 is expressed in r3 and r5, and encodes a transcription factor that plays a key role in hindbrain segmentation, coordinating segment formation, specification of odd- and even-numbered rhombomeres, and cell segregation between adjacent segments, through the regulation of numerous downstream genes. In order to further elucidate the genetic network underlying hindbrain segmentation, we have undertaken the analysis of the cis-regulatory sequences governing Krox20 expression. We have found that the control of Krox20 transcription relies on three very long-range (200 kb) enhancer elements (A, B and C) that are conserved between chick, mouse and human genomes. Elements B and C are activated at the earliest stage of Krox20 expression in r5 and r3-r5, respectively, and do not require the Krox20 protein. These elements are likely to function as initiators of Krox20 expression. Element B contains a binding site for the transcription factor vHNF1, the mutation of which abolishes its activity, suggesting that vHNF1 is a direct initiator of Krox20 expression in r5. Element A contains Krox20-binding sites, which are required, together with the Krox20 protein, for its activity. This element therefore allows the establishment of a direct positive autoregulatory loop, which takes the relay of the initiator elements and maintains Krox20 expression. Together, our studies provide a basis for a model of the molecular mechanisms controlling Krox20 expression in the developing hindbrain and neural crest. PMID:16495311

Chomette, Diane; Frain, Monique; Cereghini, Silvia; Charnay, Patrick; Ghislain, Julien

2006-04-01

242

Solar Advisor Model User Guide for Version 2.0  

SciTech Connect

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.

Gilman, P.; Blair, N.; Mehos, M.; Christensen, C.; Janzou, S.; Cameron, C.

2008-08-01

243

Vacuum-UV fluorescence spectroscopy of PF3 in the range 9-20 eV  

NASA Astrophysics Data System (ADS)

The vacuum-UV and visible spectroscopy of PF3 using fluorescence excitation and dispersed emission techniques is reported. The fluorescence excitation spectrum has been recorded following photoexcitation with monochromatized synchrotron radiation from the Daresbury, UK source in the energy range 9-20 eV with an average resolution of ˜0.015 eV. Transitions to the three lowest-energy bands in the Rydberg spectra show resolved vibrational structure, they are assigned to transitions to the (8a1)-1 4p, 5p, and 6p Rydberg states of PF3, and fluorescence is due to valence transitions in the PF2 radical. From a Franck-Condon analysis of the vibrational structure, it is shown that the FPF bond angle in PF3 increases by ˜14±1° upon photoexcitation. The use of optical filters shows that at least three excited electronic states of PF2 are responsible for the induced emission. Dispersed emission spectra in the UV/visible region have been recorded with an optical resolution of 8 nm at the BESSY 1, Germany synchrotron source at the energies of all the peaks in the excitation spectrum. Four different decay channels are observed: (a) PF2 Ã 2A1-X˜2B1 fluorescence in the wide range 320-550 nm for photon energies around 9.8 eV, (b) PF2 ÖX˜, and B˜ 2B2-X˜ 2B1 fluorescence at ˜300 nm for photon energies around 11.0 eV, (c) PF22A1-X˜ 2B1 and ? 2B1 (2?)-Ã 2A1 fluorescence at ˜222 and 325 nm, respectively, for photon energies around 14.4 eV, and (d) PF A 3?-X 3?- fluorescence between 300-380 nm for photon energies around 16.1 eV. These assignments are confirmed by action spectra in which the excitation energy of the vacuum-UV radiation is scanned with detection of the fluorescence at a fixed, dispersive wavelength. Using the single-bunch mode of the BESSY 1 source, we have attempted to measure the lifetimes of the emitting states, but the timing profile of the source imposes an upper limit on lifetimes that can be measured of ˜500 ns. We have therefore only been able to measure values for the bent C˜ 2A1 and linear ? 2B1 (2?) states of PF2 of 14.7 and 7.9 ns, respectively; the lifetimes of the other emitters are too long to measure by this method. Our assignments in PF2 are heavily dependent on recent ab initio calculations on the geometries and energies of the valence electronic states of this species. Our knowledge on the electronic spectroscopy of this free radical is reviewed.

Biehl, H.; Boyle, K. J.; Seccombe, D. P.; Tuckett, R. P.; Baumgärtel, H.; Jochims, H. W.

1998-01-01

244

Anwendungen und Technologien des Web 2.0: Ein berblick  

E-print Network

Anwendungen und Technologien des Web 2.0: Ein �berblick Alexander Stocker1 und Klaus Tochtermann1 2 formieren. Folglich definiert sich die soziale Komponente des Web 2.0 über ein verändertes Verhalten seiner User. Web-2.0-Plattformen sind jedoch vielmehr sozio-technische Artefakte und basie- ren auf speziellen

Hammerton, James

245

IBM Communications Sector Web 2.0 Meets Telecom  

E-print Network

IBM Communications Sector Web 2.0 Meets Telecom Marty Slatnick, Telecom Solutions Labs IBM Global Technology Analyst IBM Software Group #12;Web 2.0 Meets Telecom Page 2 Executive summary Communications and improving the customer experience. With the emergence of new Web 2.0 companies, service providers now face

246

In-situ Long-range Alpha Particles and X-ray Detection for Thin-film Pd Cathodes During Electrolysis in Li_2SO_4/H_2O  

NASA Astrophysics Data System (ADS)

Measurements of long-range alpha and soft X-ray emissions have been performed using cyclotron calibrated CR-39 plastic track and LiF/Al_2O_3:C-Thermo-Luminescent (TLD) detectors. Application of CR-39 and TLD detectors to the surface of the thin Pd film-cathodes sputtered on the insulator substrate (glass, Al_2O_3, PMMA) allows detection of both alpha and soft X-ray emissions simultaneously with excess heat measurements during electrolysis using 1 Molar Li_2SO_4/H_20 electrolyte. The alpha particles in the range of 8.0 < E< 30.0 MeV (which produced alpha tracks with diameters d, in the range, 7.6> d> 6.0 ?m) were detected upon the electrolysis. Those alpha-tracks are quite unique, never having been observed during CR-39 exposure with trans-uranium alpha -sources (Am^241, Pu^239). The TLD measurement shows generation of the low intensity 5.0-10.0 keV X-ray quanta (?x < 5.0 s -1*cm-2) accompanying the alpha emission.

Lipson, A. G.; Roussetski, A. S.; Castano, C. H.; S-O, Kim; Miley, G. H.

2002-03-01

247

GEM Building Taxonomy (Version 2.0)  

USGS Publications Warehouse

/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 team validated that the GEM Building Taxonomy is highly functional, robust and able to describe different buildings aroun

Brzev, S.; Scawthorn, C.; Charleson, A.W.; Allen, L.; Greene, M.; Jaiswal, Kishor; Silva, V.

2013-01-01

248

Reaction mechanisms in the system Ne20+Ho165: Measurement and analysis of forward recoil range distributions  

NASA Astrophysics Data System (ADS)

Keeping in view the study of complete and incomplete fusion of heavy ions with a target, the forward recoil range distributions of several evaporation residues produced at 164 MeV Ne20-ion beam energy have been measured for the system Ne20+Ho165. The recoil catcher activation technique followed by off-line gamma spectroscopy has been employed. Measured forward recoil range distributions of these evaporation residues show evidence of several incomplete fusion channels in addition to complete fusion. The entire and partial linear momentum transfers inferred from these recoil range distributions were used to identify the evaporation residues formed by complete and incomplete fusion mechanisms. The results indicate the occurrence of incomplete fusion involving the breakup of Ne20 into He4+O16 and/or Be8+C12 followed by fusion of one of the fragments with target nucleus Ho165. Complete and incomplete fusion reaction channels have been identified in the production of various evaporation residues and an attempt has been made to separate out relative contributions of complete and incomplete fusion components from the analysis of the measured recoil range distribution data. The total contribution of complete and incomplete fusion channels has also been estimated.

Singh, D.; Ali, R.; Ansari, M. Afzal; Rashid, M. H.; Guin, R.; Das, S. K.

2009-05-01

249

Dynamic properties of Indiana, Fort Knox and Utah test range limestones and Danby Marble over the stress range 1 to 20 GPa  

SciTech Connect

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.

Furnish, M.D.

1994-12-01

250

TVGuide2.0: applying the Web2.0 fundamentals to IDTV  

Microsoft Academic Search

In this paper we introduce our experiences in applying the Web 2.0 philosophy to build a TV guide system for Interactive Digital\\u000a TV (IDTV) platforms. Subscribers give their opinion about TV content and, informally, a folksonomy is progressively built.\\u000a Based on this shared knowledge, the TV guide obtains personal recommendations and allows users to browse among the multimedia\\u000a content. Additionally,

Rebeca P. Díaz Redondo; Ana Fernández Vilas; Marta Rey-López; José Juan Pazos Arias; Alberto Gil-Solla; Manuel Ramos Cabrer; Jorge García Duque

2011-01-01

251

Removing the barriers to enterprise 2.0  

Microsoft Academic Search

Even before the advent of Web 2.0, enterprises were already looking at ways of creating or enhancing competitive advantage. Enterprise 2.0, however, with its Web 2.0-based technologies offers the opportunity to leverage the skills and knowledge of the entire organization. But despite the apparent attractiveness of this technology, not all employees are equally willing to adopt and use Enterprise 2.0.

M. H. bin Husin; P. M. C. Swatman

2010-01-01

252

Donor Relations 2.0: Using Web 2.0 to Connect with Donors Lynne M. Thomas, Northern Illinois University  

E-print Network

Donor Relations 2.0: Using Web 2.0 to Connect with Donors Lynne M. Thomas, Northern Illinois University Society of American Archivists 2009 Conference Session #401: The Potential of Web 2.0 for Donor that this paper will give you some pragmatic ideas for conducting donor relations virtually in a Web 2

Karonis, Nicholas T.

253

Compete 2.0 Thrive.The Skills Imperative  

E-print Network

Compete 2.0 Thrive.The Skills Imperative #12;The Skills Imperative COMPETE 2.0 TEAM Debra van. To learn more about the Council on Competitiveness, visit www.compete.org. COPYRIGHT © 2008 Council States of America #12;Thrive. Compete 2.0 The Skills Imperative Debra van Opstal Senior Vice President

254

Projected range and range straggling of ion-implanted lead in polystyrene materials  

NASA Astrophysics Data System (ADS)

Polystyrene targets were implanted with 5 ×1014 lead ions/cm2 at energies from 40 to 360 keV at room temperature. Projected ranges and range stragglings were measured using SIMS. Experimental results are compared with calculated values obtained using the modified Biersack theory and TRIM-95 Monte-Carlo calculations. The comparison shows that large discrepancies between TRIM-95 calculations and measured values are significantly reduced by applying the modified Biersack theory along with taking the first four moments of nuclear and electronic energy losses into consideration. The differences between calculated values obtained using the modified Biersack theory and measured values are, on average, 9% and 20% projected ranges and range stragglings, respectively.

Liang, J. H.

255

QuakeSim 2.0  

NASA Technical Reports Server (NTRS)

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 has proved useful for mid-term forecasting of earthquakes, and for detecting subtle changes in crustal deformation. The GPS time series analysis has also proved useful as a data-quality tool, enabling the discovery of station anomalies and data processing and distribution errors. Improved visualization tools enable more efficient data exploration and understanding. Tools provide flexibility to science users for exploring data in new ways through download links, but also facilitate standard, intuitive, and routine uses for science users and end users such as emergency responders.

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

256

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

PubMed

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(?1,2) (3.8 keV) emission peak was 27 eV. This spectrometer was applied to indium tin oxide particles and clearly resolved Sn-L(?) (3444 eV) and In-L(?1) (3487 eV) peaks, which could not be resolved by a widely used energy-dispersive X-ray spectrometer. PMID:23307948

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

257

RangelandsRangelands2 Society for Range Management  

E-print Network

RangelandsRangelands2 Society for Range Management Learning Natural Resource Assessment Protocols. These relationships vary with soils, climate, and vegetation. One of the strengths of qualitative proto- cols, partici- patory workshops are virtually essential to learn how to apply qualitative assessment protocols

258

Discovery of Water Maser Emission in Five AGN and a Possible Correlation Between Water Maser and Nuclear 2-10 keV Luminosities  

E-print Network

We report the discovery of water maser emission in five active galactic nuclei (AGN) with the 100-m Green Bank Telescope (GBT). The positions of the newly discovered masers, measured with the VLA, are consistent with the optical positions of the host nuclei to within 1 sigma (0.3 arcsec radio and 1.3 arcsec optical) and most likely mark the locations of the embedded central engines. The spectra of three sources, 2MASX J08362280+3327383, NGC 6264, and UGC 09618 NED02, display the characteristic spectral signature of emission from an edge-on accretion disk with maximum orbital velocity of ~700, ~800, and ~1300 km s^-1, respectively. We also present a GBT spectrum of a previously known source MRK 0034 and interpret the narrow Doppler components reported here as indirect evidence that the emission originates in an edge-on accretion disk with orbital velocity of ~500 km s^-1. We obtained a detection rate of 12 percent (5 out of 41) among Seyfert 2 and LINER systems with 10000 km s^-1 water masers with available hard X-ray data, we report a possible relationship between unabsorbed X-ray luminosity (2-10 keV) and total isotropic water maser luminosity, L_{2-10} proportional to L_{H2O}^{0.5+-0.1}, consistent with the model proposed by Neufeld and Maloney in which X-ray irradiation and heating of molecular accretion disk gas by the central engine excites the maser emission.

Paul T. Kondratko; Lincoln J. Greenhill; James M. Moran

2006-10-03

259

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

NASA Astrophysics Data System (ADS)

In this work we present differential cross sections for ?-ray emission from the reactions 19F(p,p??)19F (E? = 110, 197, 1236 and 1349 + 1357 keV), 24Mg(p,p??)24Mg (E? = 1369 keV) and 25Mg(p,p??)25Mg (E? = 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 ?g/cm2 of MgF2 deposited on thin Mylar foil with additionally evaporated 4 nm Au layer, was used as a target. The ?-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.

Zamboni, I.; Siketi?, Z.; Jakši?, M.; Bogdanovi? Radovi?, I.

2015-01-01

260

VCSELs Emitting in the 2–3 µm Wavelength Range  

Microsoft Academic Search

In this chapter, we tried to give a precise picture of the current state of the art of VCSEL technology in the 2–3 µm spectral\\u000a range. We described classical microcavities but also structures with external-cavity geometry which allows one to fabricate\\u000a devices with improved output beam properties (single transverse mode TEM00 operation) at high power. The electrically-pumped microcavities with highest

F. Genty; A. Garnache; L. Cerutti

261

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)

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.

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

1985-01-01

262

Vacuum Insulation and Achievement of 980 keV, 185 A/m2 H- Ion Beam Acceleration at JAEA for the ITER Neutral Beam Injector  

NASA Astrophysics Data System (ADS)

Vacuum insulation of -1 MV is a common issue for the HV bushing and the accelerator for the ITER neutral beam injector (NBI). The HV bushing as an insulating feedthrough has a five-stage structure and each stage consists of double-layered insulators. To sustain -1 MV in vacuum, reduction of electric field at several triple points existing around the double-layered insulators is a critical issue. To reduce electric field simultaneously at these points, three types of stress ring have been developed. In a voltage holding test of a full-scale mockup equipped with these stress rings, 120% of rated voltage was sustained and the voltage holding capability required in ITER was verified. In the MeV accelerator, whose target is the acceleration of a H- ion beam of 1 MeV, 200 A/m2, the gap between the grid support was extended to suppress breakdowns triggered by electric field concentration at the edge and corner of the grid support. This modification improved the voltage holding capability in vacuum, and the MeV accelerator succeeded in sustaining -1 MV stably. Furthermore, it appeared that the H- ions beam was deflected and a part of the beam was intercepted at the acceleration grid. This causes high heat load on the grids and breakdowns during beam acceleration. To suppress the direct interception, a new grid was designed with proper aperture displacement based on a three dimensional beam trajectory analysis. As a result, 980 keV, 185 A/m2 H- ion beam acceleration has been demonstrated, which is close to the ITER requirement.

Hiroyuki, Tobari; Masaki, Taniguchi; Mieko, Kashiwagi; Masayuki, Dairaku; Naotaka, Umeda; Haruhiko, Yamanaka; Kazuki, Tsuchida; Jumpei, Takemoto; Kazuhiro, Watanabe; Takashi, Inoue; Keishi, Sakamoto

2013-02-01

263

Cross Correlation of the 2-10 keV X-Ray Background with Radio Sources: Constraining the Large Scale Structure of the X-Ray Background  

NASA Technical Reports Server (NTRS)

We present cross-correlation analyses of the HEAO 2-10 keV diffuse X-ray map with both the combined GB6/Parkes-MIT-NRAO (GB6-PMN) 5 GHz and the FIRST 1.4 GHz radio surveys. The cross-correlation functions (CCFs) of both radio surveys with the unresolved X-ray background were detected at the 5 u level. While the large angular resolution (3 deg) of the X-ray map makes it difficult to separate the contributions of clustering from those of Poisson fluctuations, the amplitude of the CCF provides important constraints on the X-ray emissivity of the radio sources, as well as on the clustering properties of radio and X-ray sources. These constraints are subject to a number of modeling parameters, e.g., X-ray luminosity evolution, clustering evolution, the radio luminosity function, cosmological model, etc. For reasonable choices of parameters the X-ray/FIRST CCF is consistent with a correlation scale length of 6/h Mpc. This is somewhat smaller than the scale length inferred from the autocorrelation function of the FIRST survey and implies that X-ray sources are less strongly clustered than strong radio sources, a result that is consistent with previous constraints on X-ray clustering. The X-ray/GB6-PMN CCF is several times larger and is likely to be dominated by Poisson fluctuations. This implies that approx. 2% of the diffuse X-ray background arises from the GB6-PMN sources.

Boughn, Stephen P.

1998-01-01

264

Lo scenario: Web 2.0 -I Web 2.0 = termine introdotto per la prima volta nel  

E-print Network

1 Lo scenario: Web 2.0 - I · Web 2.0 = termine introdotto per la prima volta nel 2004 come titolo, del.icio.us, Wikipedia, ecc.) possono essere considerati a pieno titolo Web 2.0 Lo scenario: Web 2 a disposizione sulla rete (per es. Google Maps) a.a. 2013/14 Tecnologie Web 2 p (p g p ) · Cambia il modo di

Goy, Anna

265

Prevention 2.0: targeting cyberbullying @ school.  

PubMed

Although cyberbullying is characterized by worrying prevalence rates and associated with a broad range of detrimental consequences, there is a lack of scientifically based and evaluated preventive strategies. Therefore, the present study introduces a theory-based cyberbullying prevention program (Media Heroes; German original: Medienhelden) and evaluates its effectiveness. In a pretest-posttest design (9-month interval), schools were asked to randomly assign their participating classes to either control or intervention group. Longitudinal data were available from 593 middle school students (M Age?=?13.3 years, 53 % girls) out of 35 classes, who provided information on cyberbullying behavior as well as socio-demographic and psychosocial variables. While the present results revealed worrying prevalence rates of cyberbullying in middle school, multilevel analyses clearly demonstrate the program's effectiveness in reducing cyberbullying behavior within intervention classes in contrast to classes of the control group. Hence, this study presents a promising program which evidentially prevents cyberbullying in schools. PMID:24122481

Wölfer, Ralf; Schultze-Krumbholz, Anja; Zagorscak, Pavle; Jäkel, Anne; Göbel, Kristin; Scheithauer, Herbert

2014-12-01

266

An electrically driven terahertz metamaterial diffractive modulator with more than 20 dB of dynamic range  

SciTech Connect

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.

Karl, N.; Reichel, K.; Mendis, R.; Mittleman, D. M. [Department of Electrical and Computer Engineering, Rice University, MS 378, Houston, Texas 77251-1892 (United States); Chen, H.-T.; Taylor, A. J. [Center for Integrated Nanotechnologies, Los Alamos National Laboratory, P. O. Box 1663, MS K771, Los Alamos, New Mexico 87545 (United States); Brener, I.; Benz, A.; Reno, J. L. [Center for Integrated Nanotechnologies, Sandia National Laboratories, P. O. Box 5800, MS 1082, Albuquerque, New Mexico 87185 (United States)

2014-03-03

267

RefWorks 2.0 Fundamentals  

E-print Network

. Search results will now display an Export to RefWorks link 4. Conduct a search on "Parkinson's disease for Parkinson Disease and tremor 2. For each record you want to export, click on the check box to the left window open PubMed and carry out a simple search on "Parkinson's disease" and tremor 2. From your search

University of Technology, Sydney

268

Optical absorption spectra of deoxy- and oxyhemoglobin in the temperature range 300-20 K. Relation with protein dynamics.  

PubMed

We have studied the optical absorption spectra of human deoxy- and oxyhemoglobin in the temperature range 300-20 K and in the wavelength range 350-1350 nm. By lowering the temperature, a narrowing and a shift of all bands were observed together with a sizeable increase of the integrated intensities of the charge-transfer bands of deoxyhemoglobin. At all temperatures the spectra are in full agreement with the band assignment previously suggested in the literature and no new relevant bands have been detected for both deoxy- and oxyhemoglobin. Analysis of the first and second moment of the bands, within the framework of the harmonic Franck-Condon approximation, gave information on the dynamic properties of the heme in the heme pocket. PMID:3768470

Cordone, L; Cupane, A; Leone, M; Vitrano, E

1986-08-01

269

Cross section for induced L X-ray emission by protons of energy <400 keV  

NASA Astrophysics Data System (ADS)

In performing ion beam analysis, cross section for induced L X-ray emission plays a crucial role. There are different approaches by which these can be found experimentally or can be calculated theoretically based on various models. L X-ray production cross sections for Bi with protons in the energy range 260-400 keV at the interval of 20 keV are measured. These are compared with calculations obtained on the basis of current prevailing theories ECPSSR and ECPSSR-UA. Their importance in understanding this phenomenon and existing arguments in this regard will be highlighted.

Mohan, Harsh; Jain, Arvind Kumar; Kaur, Mandeep; Singh, Parjit S.; Sharma, Sunita

2014-08-01

270

The INTEGRAL View Of The 511 keV Annihilation Line In Our Galaxy  

NASA Astrophysics Data System (ADS)

It is well know from theory and laboratory practice that an electron-positron pair can annihilate into a couple of 511 keV (the electron rest mass) gamma ray photons. The first detection of 511 keV photons from the Galactic center region dates back to early seventies. Soon after, a continuum gamma ray emission due to 3 gamma ortho-positronium decay was also measured. A 511 keV line in the Galactic gamma ray emission gives a unique proof that a large number of positrons are injected in the astrophysical environments, but nowadays we still do not know where these particles are generated. Positrons can be generated by a number of processes, in particular beta+ decays of unstable isotopes produced by stars and supernovae and energetic outflows from compact objects, but the few claimed detections of a 511 keV line from compact galactic sources are quite controversial. This fact could be explained by propagation of positrons in the intergalactic medium before they annihilate away from the birth place. The measure made with the spectrometer SPI aboard INTernational Gamma RAy Laboratory (INTEGRAL), launched on October 17 2002, confirms that about 10E43 positrons per second annihilate in the bulge of our Galaxy. Moreover, there is some evidence of an asymmetry of the 511 keV emission along the Galactic longitude, possibly correlated with the spacial distribution of the hard X (E > 20 keV) Low Mass X-ray Binaries detected by the imager IBIS aboard INTEGRAL. With IBIS, using about 5 years of observations, we find no evidence of 511 keV point sources. With an exposure of 10 Ms, in the center of the Galaxy we estimate a 1.6 x 10E-04 ph/cm2/s flux 2 sigma upper limit; a similar limit is given in a wide area in the Galactic center region with similar exposures.

De Cesare, G.

2011-09-01

271

Library managers and information in World 2.0  

Microsoft Academic Search

Purpose – The purpose of this paper is to provide library managers with the ability to recognize and address World 2.0 information issues to enhance their ability to develop management plans for the future. Design\\/methodology\\/approach – This paper explores what World 2.0 means to library managers in three ways. Three information dimensions are identified using models to examine World 2.0

Suzie Allard

2009-01-01

272

Script To Science 2.0 For Scholarly Communication  

Microsoft Academic Search

This article attempts to trace the evolution of scholarly communication from the days of publication of Journal-des-scavans to the era of web 2.0. Explains the Open Access (OA) movement in brief. The views of Harnad (7) on OA are highlighted. The emergence of Open Access 2.0 is put in context. The authors also explain science 2.0 as the emerging practice

Rajendra Babu H; Khaiser Nikam

2009-01-01

273

Web2.0Based Learning Support Service System  

Microsoft Academic Search

The thesis took the fine courses in colleges and universities as the starting point, proposed the architecture and functional module design of Web2.0-based learning Support Service System based on analysis of the characteristics of Web2.0 and concept of learning support services system, explored the achievement process of partial functional modules, provided a new paradigm for the e-learning of Web2.0 era.

Huixia Wang; Pingli Li; Fang He; Chaoyang Zhang; Zhaoxia Dai

2009-01-01

274

Patent Fair Use2.0 Katherine J. Strandburg*  

E-print Network

265 Patent Fair Use2.0 Katherine J. Strandburg* I. Introduction .................................................................................................................266 A. The Noncontextual Focus of Patent Doctrine........................................266 II. Why Patent Fair Use Now

Loudon, Catherine

275

The EUROCALL Review, Volume 20, Number 2  

ERIC Educational Resources Information Center

"The EUROCALL Review" is published online biannually by the European Association for Computer-Assisted Language Learning (EUROCALL). This issue offers regular sections on: (1) up-to-date information on Special Interest Groups; (2) reports on on-going CALL or CALL-related R&D projects in which EUROCALL members participate; (3) reports and reviews…

Gimeno, Ana, Ed.

2012-01-01

276

LSST Science Book, Version 2.0  

Microsoft Academic Search

A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of the exciting science opportunities of the next decade. The Large Synoptic Survey Telescope (LSST) will have an effective aperture of 6.7 meters and an imaging camera with field of view of 9.6 deg^2, and will be

Paul A. Abell; Julius Allison; Scott F. Anderson; John R. Andrew; J. Roger P. Angel; Lee Armus; David Arnett; S. J. Asztalos; Tim S. Axelrod; Stephen Bailey; D. R. Ballantyne; Justin R. Bankert; Wayne A. Barkhouse; Jeffrey D. Barr; L. Felipe Barrientos; Aaron J. Barth; James G. Bartlett; Andrew C. Becker; Jacek Becla; Timothy C. Beers; Joseph P. Bernstein; Rahul Biswas; Michael R. Blanton; Joshua S. Bloom; John J. Bochanski; Pat Boeshaar; Kirk D. Borne; Marusa Bradac; W. N. Brandt; Carrie R. Bridge; Michael E. Brown; Robert J. Brunner; James S. Bullock; Adam J. Burgasser; James H. Burge; David L. Burke; Phillip A. Cargile; Srinivasan Chandrasekharan; George Chartas; Steven R. Chesley; You-Hua Chu; David Cinabro; Mark W. Claire; Charles F. Claver; Douglas Clowe; A. J. Connolly; Kem H. Cook; Jeff Cooke; Asantha Cooray; Kevin R. Covey; Christopher S. Culliton; Roelof de Jong; Willem H. de Vries; Victor P. Debattista; Francisco Delgado; Ian P. Dell'Antonio; Saurav Dhital; Rosanne Di Stefano; Mark Dickinson; Benjamin Dilday; S. G. Djorgovski; Gregory Dobler; Ciro Donalek; Gregory Dubois-Felsmann; Josef Durech; Ardis Eliasdottir; Michael Eracleous; Laurent Eyer; Emilio E. Falco; Xiaohui Fan; Christopher D. Fassnacht; Harry C. Ferguson; Yanga R. Fernandez; Brian D. Fields; Douglas Finkbeiner; Eduardo E. Figueroa; Derek B. Fox; Harold Francke; James S. Frank; Josh Frieman; Sebastien Fromenteau; Muhammad Furqan; Gaspar Galaz; A. Gal-Yam; Peter Garnavich; Eric Gawiser; John Geary; Perry Gee; Robert R. Gibson; Kirk Gilmore; Emily A. Grace; Richard F. Green; William J. Gressler; Carl J. Grillmair; Salman Habib; J. S. Haggerty; Mario Hamuy; Alan W. Harris; Suzanne L. Hawley; Alan F. Heavens; Leslie Hebb; Todd J. Henry; Edward Hileman; Eric J. Hilton; Keri Hoadley; J. B. Holberg; Matt J. Holman; Steve B. Howell; Leopoldo Infante; Zeljko Ivezic; Suzanne H. Jacoby; Bhuvnesh Jain; Jedicke; M. James Jee; J. Garrett Jernigan; Saurabh W. Jha; Kathryn V. Johnston; R. Lynne Jones; Mario Juric; Mikko Kaasalainen; Styliani; Kafka; Steven M. Kahn; Nathan A. Kaib; Jason Kalirai; Jeff Kantor; Mansi M. Kasliwal; Charles R. Keeton; Richard Kessler; Zoran Knezevic; Adam Kowalski; Victor L. Krabbendam; K. Simon Krughoff; Shrinivas Kulkarni; Stephen Kuhlman; Mark Lacy; Sebastien Lepine; Ming Liang; Amy Lien; Paulina Lira; Knox S. Long; Suzanne Lorenz; Jennifer M. Lotz; R. H. Lupton; Julie Lutz; Lucas M. Macri; Ashish A. Mahabal; Rachel Mandelbaum; Phil Marshall; Morgan May; Peregrine M. McGehee; Brian T. Meadows; Alan Meert; Andrea Milani; Christopher J. Miller; Michelle Miller; David Mills; Dante Minniti; David Monet; Anjum S. Mukadam; Ehud Nakar; Douglas R. Neill; Jeffrey A. Newman; Sergei Nikolaev; Martin Nordby; Paul O'Connor; Masamune Oguri; John Oliver; Scot S. Olivier; Julia K. Olsen; Knut Olsen; Edward W. Olszewski; Hakeem Oluseyi; Nelson D. Padilla; Alex Parker; Joshua Pepper; John R. Peterson; Catherine Petry; Philip A. Pinto; James L. Pizagno; Bogdan Popescu; Andrej Prsa; Veljko Radcka; M. Jordan Raddick; Andrew Rasmussen; Arne Rau; Jeonghee Rho; James E. Rhoads; Gordon T. Richards; Stephen T. Ridgway; Brant E. Robertson; Rok Roskar; Abhijit Saha; Ata Sarajedini; Evan Scannapieco; Terry Schalk; Rafe Schindler; Samuel Schmidt; Sarah Schmidt; Donald P. Schneider; German Schumacher; Ryan Scranton; Jacques Sebag; Lynn G. Seppala; Ohad Shemmer; Joshua D. Simon; M. Sivertz; Howard A. Smith; J. Allyn Smith; Nathan Smith; Anna H. Spitz; Adam Stanford; Keivan G. Stassun; Jay Strader; Michael A. Strauss; Christopher W. Stubbs; Donald W. Sweeney; Alex Szalay; Paula Szkody; Masahiro Takada; Paul Thorman; David E. Trilling; Virginia Trimble; Anthony Tyson; Richard Van Berg; Daniel Vanden Berk; Jake VanderPlas; Licia Verde; Bojan Vrsnak; Lucianne M. Walkowicz; Benjamin D. Wandelt; Sheng Wang; Yun Wang; Michael Warner; Risa H. Wechsler; Andrew A. West; Oliver Wiecha; Benjamin F. Williams; Beth Willman; David Wittman; Sidney C. Wolff; W. Michael Wood-Vasey; Przemek Wozniak; Patrick Young; Andrew Zentner; Hu Zhan

2009-01-01

277

Elevation-Dependent Temperature Trends in the Rocky Mountain Front Range: Changes over a 56- and 20-Year Record  

PubMed Central

Determining the magnitude of climate change patterns across elevational gradients is essential for an improved understanding of broader climate change patterns and for predicting hydrologic and ecosystem changes. We present temperature trends from five long-term weather stations along a 2077-meter elevational transect in the Rocky Mountain Front Range of Colorado, USA. These trends were measured over two time periods: a full 56-year record (1953–2008) and a shorter 20-year (1989–2008) record representing a period of widely reported accelerating change. The rate of change of biological indicators, season length and accumulated growing-degree days, were also measured over the 56 and 20-year records. Finally, we compared how well interpolated Parameter-elevation Regression on Independent Slopes Model (PRISM) datasets match the quality controlled and weather data from each station. Our results show that warming signals were strongest at mid-elevations over both temporal scales. Over the 56-year record, most sites show warming occurring largely through increases in maximum temperatures, while the 20-year record documents warming associated with increases in maximum temperatures at lower elevations and increases in minimum temperatures at higher elevations. Recent decades have also shown a shift from warming during springtime to warming in July and November. Warming along the gradient has contributed to increases in growing-degree days, although to differing degrees, over both temporal scales. However, the length of the growing season has remained unchanged. Finally, the actual and the PRISM interpolated yearly rates rarely showed strong correlations and suggest different warming and cooling trends at most sites. Interpretation of climate trends and their seasonal biases in the Rocky Mountain Front Range are dependent on both elevation and the temporal scale of analysis. Given mismatches between interpolated data and the directly measured station data, we caution against an over-reliance on interpolation methods for documenting local patterns of climatic change. PMID:22970205

McGuire, Chris R.; Nufio, César R.; Bowers, M. Deane; Guralnick, Robert P.

2012-01-01

278

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)

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.

Miranda, Felix A.; Gordon, William L.; Heinen, Vernon O.; Ebihara, Ben T.; Bhasin, Kul B.

1990-01-01

279

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)

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.

Miranda, Felix A.; Gordon, William L.; Heinen, Vernon O.; Ebihara, Ben T.; Bhasin, Kul B.

1989-01-01

280

NASA Taxonomy 2.0 Project Overview  

NASA Technical Reports Server (NTRS)

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.

Dutra, Jayne; Busch, Joseph

2004-01-01

281

Constraints on 3.55 keV line emission from stacked observations of dwarf spheroidal galaxies  

NASA Astrophysics Data System (ADS)

Several recent works have reported the detection of an unidentified x-ray line at 3.55 keV, which could possibly be attributed to the decay of dark matter (DM) particles in the halos of galaxy clusters and in the M31 galaxy. We analyze all publicly available XMM-Newton satellite data of dwarf spheroidal galaxies to test the possible DM origin of the line. Dwarf spheroidal galaxies have high mass-to-light ratios, and their interstellar medium is not a source of diffuse x-ray emission; thus, they are expected to provide the cleanest DM decay line signal. Our analysis shows no evidence for the presence of the line in the stacked spectra of the dwarf galaxies. It excludes the sterile neutrino DM decay origin of the 3.5 keV line reported by Bulbul et al. (2014) at the level of 4.1 ? under standard assumptions about the Galactic DM column density in the direction of selected dwarf galaxies and at the level of 3.2 ? assuming minimal Galactic DM column density. Our analysis is still consistent with the estimate of sterile neutrino DM parameters by Boyarsky et al. (2014) because of its larger uncertainty. However, the central value of their estimate of the mixing angle is inconsistent with our dwarf spheroidals data at the 3.4 ? (2.5 ? ) level assuming the mean (minimal) Galactic DM column density. As a byproduct of our analysis, we provide updated upper limits to the mixing angle of sterile neutrino DM in the mass range between 2 and 20 keV.

Malyshev, D.; Neronov, A.; Eckert, D.

2014-11-01

282

Thin disk laser in the 2?m wavelength range  

NASA Astrophysics Data System (ADS)

The thin disk laser is a successful concept for high output power and/or high pulse energy, high efficiency and good beam quality in the 1 ?m range. Holmium-doped materials are a promising approach to transform this success to the 2 ?m range. Ho:YAG is especially interesting for high pulse energies due to the long fluorescence lifetime (~ 8 ms) which provides good energy storage capabilities. We have realized a Ho:YAG thin-disk laser with a cw output power of 15 W at 2.09 ?m and a maximum optical-to-optical efficiency of 37%. The laser was pumped with a Tm-fiber laser. Numerical simulations of the Ho:YAG thin disk laser show the potential for further scaling. As broadly tunable alternative, also a Cr:ZnSe thin disk laser was investigated. A Tm-fiber laser and a fiber coupled diode stack were tested as pump sources. A laser power of 3.5 W was achieved with diode pumping.

Speiser, Jochen; Renz, Günther; Giesen, Adolf

2012-11-01

283

2001 Mercury Computer Systems, Inc. UML 2.0 Redux for HPECUML 2.0 Redux for HPEC  

E-print Network

© 2001 Mercury Computer Systems, Inc. UML 2.0 Redux for HPECUML 2.0 Redux for HPEC Dr. Jeffrey E. Smith Mercury Computer Systems, Inc. Manfred Koethe 88solutions Corp. High Performance Embedded Computing (HPEC) Conference September 25, 2003 #12;2© 2003 Mercury Computer Systems, Inc. UML Overview

Kepner, Jeremy

284

Human Category Learning 2.0  

PubMed Central

During the 1990’s and early 2000’s, 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? PMID:21182535

Ashby, F. Gregory; Maddox, W. Todd

2010-01-01

285

Study of Stimulated Emission in GaN Thin Films in the Temperature Range of 20 K to 700 K  

NASA Astrophysics Data System (ADS)

We report the results of an experimental study of stimulated emission (SE) and band-edge related spontaneous emission in GaN over the temperature range of 20 K to 700 K. The high quality single-crystal GaN films used in this study were grown by MOCVD on 6H-SiC and (0001) sapphire substrates. We have observed edge-emitted SE at 420 nm in GaN at 700 K, which is the highest temperature at which SE has been reported in this material system. The characteristic temperature for the SE threshold was estimated to be 180 K over the temperature range of 200 K to 700 K. The energy difference between the SE and the CW photoluminescence peaks, as well as the SE efficiency, was analyzed for the entire temperature range. This study indicates that GaN has a remarkably low temperature sensitivity compared to other direct-bandgap semiconductors and is suitable for the development of light emitting devices that can operate substantially above room temperature. This work was supported by ONR, AFOSR, BMDO, and DARPA.

Bidnyk, S.; Choi, C.-K.; Schmidt, T. J.; Krasinski, J. K.; Song, J. J.

1998-03-01

286

Information Literacy Instruction in the Web 2.0 Library  

ERIC Educational Resources Information Center

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…

Humrickhouse, Elizabeth

2011-01-01

287

Web 2.0 Strategy in Libraries and Information Services  

ERIC Educational Resources Information Center

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,…

Byrne, Alex

2008-01-01

288

Changing Paradigms Managed Learning Environments and Web 2.0  

ERIC Educational Resources Information Center

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…

Craig, Emory M.

2007-01-01

289

Titanium Language Reference Manual Version 2.20  

E-print Network

Titanium Language Reference Manual Version 2.20 P. N. Hilfinger (editor), Dan Bonachea, Kaushik Berkeley, California 94720 #12;Titanium Language Reference Manual Version 2.20 P. N. Hilfinger (editor, and Katherine Yelick August, 2006 #12;Abstract The Titanium language is a Java dialect for high

California at Irvine, University of

290

A Framework for Web 2.0 Learning Design  

ERIC Educational Resources Information Center

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…

Bower, Matt; Hedberg, John G.; Kuswara, Andreas

2010-01-01

291

Systems Engineering Leading Indicators Guide, Version 2.0  

E-print Network

The Systems Engineering Leading Indicators Guide editorial team is pleased to announce the release of Version 2.0. Version 2.0 supersedes Version 1.0, which was released in July 2007 and was the result of a project initiated ...

Lean Advancement Initiative

2010-06-29

292

What You Need to Know about Web 2.0  

ERIC Educational Resources Information Center

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…

Imperatore, Catherine

2009-01-01

293

Untangling Web 2.0's Influences on Student Learning  

ERIC Educational Resources Information Center

The recent creation of Web 2.0 applications dramatically alters the ways in which universities recruit and educate students. Technology insiders usually attribute the phrase "Web 2.0" to Tim O'Reilly, author and publisher of the ubiquitous O'Reilly series of technology books (http://oreilly.com). Although there is no shortage of definitions of Web…

Magolda, Peter M.; Platt, Glenn J.

2009-01-01

294

Web 2.0: Creating a Classroom without Walls  

ERIC Educational Resources Information Center

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.)

Barlow, Tim

2008-01-01

295

Web 2.0 in the Mathematics Classroom  

ERIC Educational Resources Information Center

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,…

McCoy, Leah P.

2014-01-01

296

Culture, Learning Styles, and Web 2.0  

ERIC Educational Resources Information Center

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…

Olaniran, Bolanle A.

2009-01-01

297

Heliospheric Neutral Atom Spectra Between 0.01 and 6 keV fom IBEX  

NASA Technical Reports Server (NTRS)

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.

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

298

Heliospheric neutral atom spectra between 0.01 and 6 keV from IBEX  

NASA Astrophysics Data System (ADS)

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 ~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 ~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-1.

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.; Möbius, E.; Moore, T. E.; Petrinec, S. M.; Quinn, M.; Reisenfeld, D.; Saul, L. A.; Scheer, J. A.; Schwadron, N.; Trattner, K. J.; Vanderspek, R.; Wurz, P.

2012-07-01

299

20 CFR 212.2 - Military service defined.  

Code of Federal Regulations, 2010 CFR

20 Employees' Benefits 1 2010-04-01 2010-04-01...defined. 212.2 Section 212.2 Employees' Benefits RAILROAD RETIREMENT BOARD...air forces of the United States until resignation or discharge therefrom. The...

2010-04-01

300

Range parameters study of Pb and Au implanted into SiC films  

NASA Astrophysics Data System (ADS)

SiC films were implanted with Pb and Au ions in a 20-250 keV energy range. Range parameters were determined using the Rutherford backscattering technique. The experimental results are 20% higher than the theoretical predictions by Ziegler, Biersack and Littmark. Good agreement is only achieved when inelastic effects are included in the nuclear stopping regime.

Fichtner, P. F. P.; Behar, M.; Fink, D.; Goppelt, P.; Grande, P. L.

1992-02-01

301

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)

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 ? = 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 ? 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.

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

302

Biofuels Science and Facilities (Carbon Cycle 2.0)  

SciTech Connect

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/

Keasling, Jay D

2010-02-04

303

Energy Demand in China (Carbon Cycle 2.0)  

SciTech Connect

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/

Price, Lynn

2010-02-02

304

Carbon Cycle 2.0: Ashok Gadgil: global impact  

SciTech Connect

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/

Ashok Gadgi

2010-02-09

305

Carbon Cycle 2.0: Ashok Gadgil: global impact  

ScienceCinema

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/

Ashok Gadgi

2010-09-01

306

Biofuels Science and Facilities (Carbon Cycle 2.0)  

ScienceCinema

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/

Keasling, Jay D

2011-06-03

307

Neutron scattering and scaling behavior in URu2Zn20 and YbFe2Zn20  

NASA Astrophysics Data System (ADS)

The dynamic susceptibility ??(?E) , measured by inelastic neutron-scattering measurements, shows a broad peak centered at Emax=15meV for the cubic actinide compound URu2Zn20 and 7 meV at zone center and at the (1/2, 1/2, 1/2) zone boundary for the rare-earth counterpart compound YbFe2Zn20 . For URu2Zn20 , the low-temperature susceptibility and magnetic specific-heat coefficient ?=Cmag/T take the values ?=0.011emu/mole and ?=190mJ/moleK2 at T=2K . These values are roughly three times smaller, and Emax is three times larger, than recently reported for the related compound UCo2Zn20 , so that ? and ? scale inversely with the characteristic energy for spin fluctuations, Tsf=Emax/kB . While ?(T) , Cmag(T) , and Emax of the 4f compound YbFe2Zn20 are very well described by the Kondo impurity model, we show that the model works poorly for URu2Zn20 and UCo2Zn20 , suggesting that the scaling behavior of the actinide compounds arises from spin fluctuations of itinerant 5f electrons.

Wang, C. H.; Christianson, A. D.; Lawrence, J. M.; Bauer, E. D.; Goremychkin, E. A.; Kolesnikov, A. I.; Trouw, F.; Ronning, F.; Thompson, J. D.; Lumsden, M. D.; Ni, N.; Mun, E. D.; Jia, S.; Canfield, P. C.; Qiu, Y.; Copley, J. R. D.

2010-11-01

308

Oh! Web 2.0, Virtual Reference Service 2.0, Tools and Techniques (I): A Basic Approach  

ERIC Educational Resources Information Center

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…

Arya, Harsh Bardhan; Mishra, J. K.

2011-01-01

309

The coordinate system ? × ? on L 2([0, 1]) × L 2([0, 1]) for the AKNS operator  

NASA Astrophysics Data System (ADS)

A proof of the following result is given. The map ? × ? for the AKNS operator on the unit interval associated to the separated boundary conditions is one to one on L 2([0, 1]) × L 2([0, 1]). The Schrödinger operators are considered in an appendix.

Amour, Laurent

2014-06-01

310

Ideation2.0 project: web2.0 tools to support brainstorming networks and innovation teams  

Microsoft Academic Search

Ideation2.0 project aims at improving innovation processes with Web2.0 based tools. These tools we have developed enable the participation of many people in idea generation and evaluation sessions forming brainstorming networks. They also allow the formation of innovation development teams based on the affinity among the participants for their creativity and their interest in implementing the ideas.

Oscar Ardaiz-villanueva; Xabier Nicuesa Chacón; Oscar Brene Artazcoz; María Luisa Sanz De Acedo Lizarraga; María Teresa Sanz De Acedo Baquedano

2009-01-01

311

One-sided imaging of large, dense objects using the 511 keV photons from induced pair production  

SciTech Connect

The use of annihilation photons from photon-induced electron-positron pair production as a means of inspecting objects when only one side is accessible is described. The Z2 dependence of the pair production cross section and the high penetration of 511 keV photons suggest that this method should be capable of localizing high Z materials in lower Z matrices. The experimental results for the dependence of the back streaming photon yield on Z indicate that dynamic ranges of the order of 20 may be obtained for materials with 4 < Z < 82. Results for point to point images obtained in line scans of representative geometries are also shown. Simulation studies based on the EGS4 Monte Carlo code were also performed and their results show an agreement with experimental data of the order of 5%.

Tavora, L.M.; Gilboy, W.B.; Morton, E.J. [Univ. of Surrey, Guildford (United Kingdom). Physics Dept.; Morgado, R.E.; Estep, R.J.; Rawool-Sullivan, M. [Los Alamos National Lab., NM (United States)

1998-03-01

312

JUNGFRAU 0.2: prototype characterization of a gain-switching, high dynamic range imaging system for photon science at SwissFEL and synchrotrons  

NASA Astrophysics Data System (ADS)

JUNGFRAU (adJUstiNg Gain detector FoR the Aramis User station) is a two-dimensional pixel detector for photon science applications at free electron lasers and synchrotron light sources. It is developed for the SwissFEL currently under construction at the Paul Scherrer Institute, Switzerland. Characteristics of this application-specific integrating circuit readout chip include single photon sensitivity and low noise over a dynamic range of over four orders of magnitude of photon input signal. These characteristics are achieved by a three-fold gain-switching preamplifier in each pixel, which automatically adjusts its gain to the amount of charge deposited on the pixel. The final JUNGFRAU chip comprises 256 × 256 pixels of 75 × 75 ?m2 each. Arrays of 2 × 4 chips are bump-bonded to monolithic detector modules of about 4 × 8 cm2. Multi-module systems up to 16 Mpixels are planned for the end stations at SwissFEL. A readout rate in excess of 2 kHz is anticipated, which serves the readout requirements of SwissFEL and enables high count rate synchrotron experiments with a linear count rate capability of > 20 MHz/pixel. Promising characterization results from a 3.6 × 3.6 mm2 prototype (JUNGFRAU 0.2) with fluorescence X-ray, infrared laser and synchrotron irradiation are shown. The results include an electronic noise as low as 100 electrons root-mean-square, which enables single photon detection down to X-ray energies of about 2 keV. Noise below the Poisson fluctuation of the photon number and a linearity error of the pixel response of about 1% are demonstrated. First imaging experiments successfully show automatic gain switching. The edge spread function of the imaging system proves to be comparable in quality to single photon counting hybrid pixel detectors.

Jungmann-Smith, J. H.; Bergamaschi, A.; Cartier, S.; Dinapoli, R.; Greiffenberg, D.; Johnson, I.; Maliakal, D.; Mezza, D.; Mozzanica, A.; Ruder, Ch; Schaedler, L.; Schmitt, B.; Shi, X.; Tinti, G.

2014-12-01

313

CDF/TOP/PUBLIC/3317 Version 2.0  

E-print Network

­ nomenology on May 22, is about the CDF observation of top. 1 The topics covered will be the dilepton analysis, the cross section and the mass analysis. The CDF Collaboration consists of 440 physicists (Fig. 1). We haveCDF/TOP/PUBLIC/3317 Version 2.0 September 20, 1995 International Journal of Modern Physics A, f c

Fermilab

314

Environmental Public Health Performance Standards (v 2.0)  

E-print Network

Environmental Public Health Performance Standards (v 2.0) January 7, 2010 #12;Environmental Public.......................................................................................................................................................3 Essential Environmental Public Health Services...................................................................................................................8 Essential Service #1: Monitor Environmental and Health Status to Identify and Solve Community

315

36 CFR 2.20 - Skating, skateboards, and similar devices.  

Code of Federal Regulations, 2010 CFR

...PROTECTION, PUBLIC USE AND RECREATION § 2.20 Skating, skateboards, and similar devices. Using roller skates, skateboards, roller skis, coasting vehicles, or similar devices is prohibited, except in designated...

2010-07-01

316

36 CFR 2.20 - Skating, skateboards, and similar devices.  

Code of Federal Regulations, 2011 CFR

...PROTECTION, PUBLIC USE AND RECREATION § 2.20 Skating, skateboards, and similar devices. Using roller skates, skateboards, roller skis, coasting vehicles, or similar devices is prohibited, except in designated...

2011-07-01

317

42 CFR 2.20 - Relationship to State laws.  

Code of Federal Regulations, 2011 CFR

...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 laws. The statutes authorizing...

2011-10-01

318

42 CFR 2.20 - Relationship to State laws.  

Code of Federal Regulations, 2010 CFR

...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 laws. The statutes authorizing...

2010-10-01

319

42 CFR 2.20 - Relationship to State laws.  

Code of Federal Regulations, 2014 CFR

...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 laws. The statutes authorizing...

2014-10-01

320

50 CFR 20.2 - Relation to other provisions.  

Code of Federal Regulations, 2010 CFR

...WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Introduction § 20.2 Relation to other provisions. (a) Migratory bird permits. The provisions of this part...of this subchapter. (b) Migratory bird hunting stamps. The provisions of...

2010-10-01

321

50 CFR 20.2 - Relation to other provisions.  

Code of Federal Regulations, 2011 CFR

...WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Introduction § 20.2 Relation to other provisions. (a) Migratory bird permits. The provisions of this part...of this subchapter. (b) Migratory bird hunting stamps. The provisions of...

2011-10-01

322

2. Historic American Buildings Survey Photocopy from Harpers, vol. 20 ...  

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

2. Historic American Buildings Survey Photocopy from Harpers, vol. 20 1859 Courtesy of Library of Congress NORTH AND EAST FRONTS - United States General Post Office, Between Seventh, Eighth, E, & F Streets, Northwest, Washington, District of Columbia, DC

323

Information management using Web 2.0 technology  

E-print Network

Web 2.0, the ultimate platform for tacit based knowledge work has finally arrived. User driven, collaborative platform based tools including wikis, web mash-ups, discussion boards, linkage based search engines, and tagging ...

Duffy, Juliet (Juliet Maria)

2009-01-01

324

What Web 2.0 Means to Facilities Professionals  

ERIC Educational Resources Information Center

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…

Allen, Scott

2008-01-01

325

Web 2.0 applications in top Chinese university libraries  

Microsoft Academic Search

Purpose – This paper aims to explore the status and construction pattern of Web 2.0 technologies employed in top Chinese university libraries, their functionalities and features. Design\\/methodology\\/approach – A combination of online survey and content analysis methodology is applied to a sample of 38 top Chinese university libraries' web sites. The Web 2.0 tools are categorized by generally accepted standards

Zhiping Han; Yan Quan Liu

2010-01-01

326

Bringing Web 2.0 to web lectures  

Microsoft Academic Search

At many universities, web lectures have become an integral part of the e-learning portfolio over the last few years. While many aspects of the technology involved, like automatic recording techniques or innovative interfaces for replay, have evolved at a rapid pace, web lecturing has remained independent of other important developments such as Web 2.0. Web 2.0 is an emerging trend

Markus Ketterl; Robert Mertens; Oliver Vornberger

2009-01-01

327

Web2.0-based Enterprise Knowledge Management Model  

Microsoft Academic Search

In the knowledge economy, enterprise knowledge management has become one of the core competitiveness of enterprises. As an important business tool to upgrade and maintain knowledge management, knowledge management system is being more and more attention. In this paper, the characteristics of the Web2.0 were analyzed. For the existing problems in the current Knowledge management system, a Web2.0-based Knowledge Management

Sisi Hu; Liyong Wan; Rui Zeng

2010-01-01

328

Microionization chamber air-kerma calibration coefficients as a function of photon energy for x-ray spectra in the range of 20-250 kVp relative to {sup 60}Co  

SciTech Connect

Purpose: To investigate the applicability of a wide range of microionization chambers for reference dosimetry measurements in low- and medium-energy x-ray beams. Methods: Measurements were performed with six cylindrical microchamber models, as well as one scanning chamber and two Farmer-type chambers for comparison purposes. Air-kerma calibration coefficients were determined at the University of Wisconsin Accredited Dosimetry Calibration Laboratory for each chamber for a range of low- and medium-energy x-ray beams (20-250 kVp), with effective energies ranging from 11.5 keV to 145 keV, and a {sup 60}Co beam. A low-Z proof-of-concept microchamber was developed and calibrated with and without a high-Z silver epoxy on the collecting electrode. Results: All chambers composed of low-Z materials (Z{<=} 13), including the Farmer-type chambers, the scanning chamber, and the PTW TN31014 and the proof-of-concept microchambers, exhibited air-kerma calibration coefficients with little dependence on the quality of the beam. These chambers typically exhibited variations in calibration coefficients of less than 3% with the beam quality, for medium energy beams. However, variations in air-kerma calibration coefficients of greater than 50% were measured over the range of medium-energy x-ray beams for each of the microchambers containing high-Z collecting electrodes (Z > 13). For these high-Z chambers, which include the Exradin A14SL and A16 chambers, the PTW TN31006 chamber, the IBA CC01 chamber, and the proof-of-concept chamber containing silver, the average variation in air-kerma calibration coefficients between any two calibration beams was nearly 25% over the entire range of beam qualities investigated. Conclusions: Due to the strong energy dependence observed with microchambers containing high-Z components, these chambers may not be suitable dosimeters for kilovoltage x-ray applications, as they do not meet the TG-61 requirements. It is recommended that only microchambers containing low-Z materials (Z{<=} 13) be considered for air-kerma calibrations for reference dosimetry in low- and medium-energy x-ray beams.

Snow, J. R.; Micka, J. A.; DeWerd, L. A. [Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States)

2013-04-15

329

Low-power 20-meter 3D ranging SPAD camera based on continuous-wave indirect time-of-flight  

NASA Astrophysics Data System (ADS)

Three dimensional (3D) image acquisitions is the enabling technology of a great number of applications; culture heritage morphology study, industrial robotics, automotive active safety and security access control are example of applications. The most important feature is the high frame-rate, to detect very fast events within the acquired scenes. In order to reduce the computational complexity, Time-of-Flight algorithms for single sensor cameras are used. To achieve high-frame rate and high distance measurement accuracy it is important to collect the most part of the reflected light using sensor with very high sensitivity, allowing the implementation of a low-power light source. We designed and developed a single-photon detection based 3D ranging camera, capable to acquire distance image up to 22.5 m, with a resolution down to one centimeter. The light source used in this prototype employs 8 laser diodes sinusoidally modulated. The imager used in the application is based on Single-Photon Avalanche Diodes (SPADs) fabricated in a standard CMOS 0.35 ?m technology. The sensor has 1024 pixels arranged in a 32x32 squared layout, with overall dimensions of 3.5mm x 3.5mm. The camera acquires 3D images through the continuous-wave indirect Time of Flight (cw-iTOF) technique. The typical frame-rate is 20 fps while the theoretical maximum frame-rate is 5 kfps. The precision is better than 5 cm within 22.5 m range, and can be effectively used in indoor applications, e.g. in industrial environment.

Bellisai, S.; Ferretti, L.; Villa, F.; Ruggeri, A.; Tisa, S.; Tosi, A.; Zappa, F.

2012-06-01

330

Month HDD1/ Precip Snow 2" 4" 8" 20" 40"  

E-print Network

Month HDD1/ GDU2/ Precip Snow 2" 4" 8" 20" 40" Jan 10.0 1703.5 0.36 5.4 26.1 27.1 29.2 32.1 - 4355 temperature, growing degree units (GDU), precipitation, snow, and evaporation. Solar radiation based on 1972

Netoff, Theoden

331

Low Cost Solar Energy Conversion (Carbon Cycle 2.0)  

SciTech Connect

Ramamoorthy Ramesh from LBNL's Materials Science Division 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/

Ramesh, Ramamoorthy

2010-02-04

332

Integrating QR Codes andIntegrating QR Codes and Web 2.0 Technologies toWeb 2.0 Technologies to  

E-print Network

Integrating QR Codes andIntegrating QR Codes and Web 2.0 Technologies toWeb 2.0 Technologies help ? #12;When QR codes meet Web 2.0When QR codes meet Web 2.0...... In a discussion with Mr. Michael of the popular Web 2.0we are well aware of the popular Web 2.0 technologies being continuously evolved and used

Tam, Vincent W. L.

333

Geologic Carbon Sequestration and Biosequestration (Carbon Cycle 2.0)  

SciTech Connect

Don DePaolo, Director of LBNL's Earth Sciences Division, 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/

DePaolo, Don [Director, LBNL Earth Sciences Division] [Director, LBNL Earth Sciences Division

2010-02-03

334

Carbon Cycle 2.0: Paul Alivisatos: Introduction  

SciTech Connect

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/

Paul Alivisatos

2010-02-09

335

GTA P.M. PEAK MODEL Version 2.0  

E-print Network

WORKING DRAFT GTA P.M. PEAK MODEL Version 2.0 And HALTON REGION SUB-MODEL Documentation & Users' Guide Prepared by Peter Dalton July 2001 #12;GTA P.M. Model Page 2 30/05/2002 Contents 1.0 P.M. Peak ................................................................................................ 4 Table 1 - Features of the P.M. Peak Period Model

Toronto, University of

336

20. Elevator no. 2: stairway, doorway and exterior north wall ...  

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

20. Elevator no. 2: stairway, doorway and exterior north wall of control room (floor 5, elevated to right), with control shafts and turnhead distributor, facing east - Washburn Crosby Company Elevators No. 2 & 3, 900 & 1000 Second Avenue, South, Minneapolis, Hennepin County, MN

337

Imaging shocked sapphire in the 20--40 GPa range: The effect of crystal orientation on optical emission  

NASA Astrophysics Data System (ADS)

We have taken short exposure gated images (<= 50ns) of 20--40 GPa shock loaded, single crystal sapphire windows of the c-cut (0001), r-cut (1,-1,0,2), and a-cut (1,1,-2,0) orientations. We find that the c-cut and a-cut windows show evidence of intense emission in randomly distributed localized regions, whereas the r-cut windows were remarkably free of this effect and showed sparse emission. We interpret this effect in terms of slip band heating as previously demonstrated for ?-quartz (Shock-induced luminescence from x-cut quartz and z-cut lithium niobate, P.J. Brannon, R.W. Morris, C.H. Konrad and J.R. Asay, Shock waves in condensed matter - 1983), Asay, Graham, Straub eds., Elsevier Science Publishers 1984 and discuss the potential impact of these results on the usage of sapphire as a window for optical experiments on shock-loaded materials in which the Al_2O3 windows are shocked above the Hugoniot elastic limit.

Hare, David E.; Holmes, N. C.

1999-06-01

338

Web 2.0, Cloud Computing, and Earthquake Forecasting Geoffrey Fox1,2  

E-print Network

Web 2.0, Cloud Computing, and Earthquake Forecasting Geoffrey Fox1,2 and Marlon Pierce1 1 Community of Informatics, Indiana University, Bloomington, IN 47404 We discuss the impact of Web 2.0 and Cloud Computing) introduces several important parallel programming models relevant to data-mining. Web 2.0 provides

339

Integration of Collaborative Information Systems in Web 2.0 Ahmet E. Topcu1,2  

E-print Network

Integration of Collaborative Information Systems in Web 2.0 Ahmet E. Topcu1,2 , Ahmet Fatih a new integration model that uses tools and services for supporting Web 2.0. This integration model defines a structure for a missing feature of Web 2.0. The model integrates a number of existing online

340

Integration of Collaborative Information Systems in Web 2.0 Ahmet E. Topcu1,2  

E-print Network

1 Integration of Collaborative Information Systems in Web 2.0 Ahmet E. Topcu1,2 , Ahmet Fatih a new integration model that uses tools and services for supporting Web 2.0. This integration model defines a structure for a missing feature of Web 2.0. The model integrates a number of existing online

341

Purification, crystallization and preliminary X-ray diffraction analysis of the IL-20-IL-20R1-IL-20R2 complex  

SciTech Connect

Interleukin-20 (IL-20) is an IL-10-family cytokine that regulates innate and adaptive immunity in skin and other tissues. In addition to protecting the host from various external pathogens, dysregulated IL-20 signaling has been shown to contribute to the pathogenesis of human psoriasis. IL-20 signals through two cell-surface receptor heterodimers, IL-20R1-IL-20R2 and IL-22R1-IL-20R2. In this report, crystals of the IL-20-IL-20R1-IL-20R2 ternary complex have been grown from polyethylene glycol solutions. The crystals belonged to space group P4{sub 1}2{sub 1}2 or P4{sub 3}2{sub 1}2, with unit-cell parameters a = 111, c = 135 {angstrom}, and diffracted X-rays to 3 {angstrom} resolution. The crystallographic asymmetric unit contains one IL-20-IL-20R1-IL-20R2 complex, corresponding to a solvent content of approximately 54%.

Logsdon, Naomi J.; Allen, Christopher E.; Rajashankar, Kanagalaghatta R.; Walter, Mark R. (Cornell); (UAB)

2012-02-08

342

Incorporating Web 2.0 Technologies from an Organizational Perspective  

NASA Astrophysics Data System (ADS)

The Arctic Research Consortium of the United States (ARCUS) provides support for the organization, facilitation, and dissemination of online educational and scientific materials and information to a wide range of stakeholders. ARCUS is currently weaving the fabric of Web 2.0 technologies—web development featuring interactive information sharing and user-centered design—into its structure, both as a tool for information management and for educational outreach. The importance of planning, developing, and maintaining a cohesive online platform in order to integrate data storage and dissemination will be discussed in this presentation, as well as some specific open source technologies and tools currently available, including: ? Content Management: Any system set up to manage the content of web sites and services. Drupal is a content management system, built in a modular fashion allowing for a powerful set of features including, but not limited to weblogs, forums, event calendars, polling, and more. ? Faceted Search: Combined with full text indexing, faceted searching allows site visitors to locate information quickly and then provides a set of 'filters' with which to narrow the search results. Apache Solr is a search server with a web-services like API (Application programming interface) that has built in support for faceted searching. ? Semantic Web: The semantic web refers to the ongoing evolution of the World Wide Web as it begins to incorporate semantic components, which aid in processing requests. OpenCalais is a web service that uses natural language processing, along with other methods, in order to extract meaningful 'tags' from your content. This metadata can then be used to connect people, places, and things throughout your website, enriching the surfing experience for the end user. ? Web Widgets: A web widget is a portable 'piece of code' that can be embedded easily into web pages by an end user. Timeline is a widget developed as part of the SIMILE project at MIT (Massachusetts Institute of Technology) for displaying time-based events in a clean, horizontal timeline display. Numerous standards, applications, and 3rd party integration services are also available for use in today's Web 2.0 environment. In addition to a cohesive online platform, the following tools can improve networking, information sharing, and increased scientific and educational collaboration: ? Facebook (Fan pages, social networking, etc) ? Twitter/Twitterfeed (Automatic updates in 3 steps) ? Mobify.me (Mobile web) ? Wimba, Adobe Connect, etc (real time conferencing) Increasingly, the scientific community is being asked to share data and information within and outside disciplines, with K-12 students, and with members of the public and policy-makers. Web 2.0 technologies can easily be set up and utilized to share data and other information to specific audiences in real time, and their simplicity ensures their increasing use by the science community in years to come.

Owens, R.

2009-12-01

343

Collaborative Writing with Web 2.0 Technologies: Education Students' Perceptions  

ERIC Educational Resources Information Center

Web 2.0 technologies are becoming popular in teaching and learning environments. Among them several online collaborative writing tools, like wikis and blogs, have been integrated into educational settings. Research has been carried out on a wide range of subjects related to wikis, while other, comparable tools like Google Docs and EtherPad remain…

Brodahl, Cornelia; Hadjerrouit, Said; Hansen, Nils Kristian

2011-01-01

344

The Open Ed Tech: Never Mind the Edupunks; or, The Great Web 2.0 Swindle  

ERIC Educational Resources Information Center

Has the wave of the open web crested? What does "open educational technology" look like, and does it stand for anything? In this article, the authors discuss the rise of open educational technology. The present range of Web 2.0 service providers offers a self-evident strategic technology framework. Without much effort, online teachers and learners…

Lamb, Brian; Groom, Jim

2010-01-01

345

UCbase 2.0: ultraconserved sequences database (2014 update)  

PubMed Central

UCbase 2.0 (http://ucbase.unimore.it) is an update, extension and evolution of UCbase, a Web tool dedicated to the analysis of ultraconserved sequences (UCRs). UCRs are 481 sequences >200 bases sharing 100% identity among human, mouse and rat genomes. They are frequently located in genomic regions known to be involved in cancer or differentially expressed in human leukemias and carcinomas. UCbase 2.0 is a platform-independent Web resource that includes the updated version of the human genome annotation (hg19), information linking disorders to chromosomal coordinates based on the Systematized Nomenclature of Medicine classification, a query tool to search for Single Nucleotide Polymorphisms (SNPs) and a new text box to directly interrogate the database using a MySQL interface. To facilitate the interactive visual interpretation of UCR chromosomal positioning, UCbase 2.0 now includes a graph visualization interface directly linked to UCSC genome browser. Database URL: http://ucbase.unimore.it PMID:24951797

Lomonaco, Vincenzo; Martoglia, Riccardo; Mandreoli, Federica; Anderlucci, Laura; Emmett, Warren; Bicciato, Silvio; Taccioli, Cristian

2014-01-01

346

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

SciTech Connect

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.

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

347

The (3He,tf) as a surrogate reaction to determine (n,f) cross sections in the 10 to 20 MeV energy range  

SciTech Connect

The surrogate reaction 238U(3He,tf) is used to determine the 237Np(n,f) cross section indirectly over an equivalent neutron energy range from 10 to 20 MeV. A self-supporting ~;;761 mu g/cm2 metallic 238U foil was bombarded with a 42 MeV 3He2+ beam from the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory (LBNL). Outgoing charged particles and fission fragments were identified using the Silicon Telescope Array for Reaction Studies (STARS), consists of two 140 mu m and one 1000 mu m Micron S2 type silicon detectors. The 237Np(n,f) cross sections, determined indirectly, were compared with the 237Np(n,f) cross section data from direct measurements, the Evaluated Nuclear Data File (ENDF/B-VII.0), and the Japanese Evaluated Nuclear Data Library (JENDL 3.3) and found to closely follow those datasets. Use of the (3He,tf) reaction as a surrogate to extract (n,f) cross section in the 10 to 20 MeV equivalent neutron energy is found to be suitable.

Basunia, M. S.; Clark, R. M.; Goldblum, B. L.; Bernstein, L. A.; Phair, L.; Burke, J. T.; Beausang, C. W.; Bleuel, D. L.; Darakchieva, B.; Dietrich, F. S.; Evtimova, M.; Fallon, P.; Gibelin, J.; Hatarik, R.; Jewett, C. C.; Lesher, S. R.; McMahan, M. A.; Rodriguez-Vieitez, E.; Wiedeking, M.

2009-02-25

348

mHealth 2.0: Experiences, Possibilities, and Perspectives  

PubMed Central

With more than 1 billion users having access to mobile broadband Internet and a rapidly growing mobile app market, all stakeholders involved have high hopes that this technology may improve health care. Expectations range from overcoming structural barriers to access in low-income countries to more effective, interactive treatment of chronic conditions. Before medical health practice supported by mobile devices ("mHealth") can scale up, a number of challenges need to be adequately addressed. From a psychological perspective, high attrition rates, digital divide of society, and intellectual capabilities of the users are key issues when implementing such technologies. Furthermore, apps addressing behavior change often lack a comprehensive concept, which is essential for an ongoing impact. From a clinical point of view, there is insufficient evidence to allow scaling up of mHealth interventions. In addition, new concepts are required to assess the efficacy and efficiency of interventions. Regarding technology interoperability, open standards and low-energy wireless protocols appear to be vital for successful implementation. There is an ongoing discussion in how far health care-related apps require a conformity assessment and how to best communicate quality standards to consumers. "Apps Peer-Review" and standard reporting via an "App synopsis" appear to be promising approaches to increase transparency for end users. With respect to development, more emphasis must be placed on context analysis to identify what generic functions of mobile information technology best meet the needs of stakeholders involved. Hence, interdisciplinary alliances and collaborative strategies are vital to achieve sustainable growth for "mHealth 2.0," the next generation mobile technology to support patient care. PMID:25099752

Diamantidis, Clarissa

2014-01-01

349

MULTI-KEV X-RAY YIELDS FROM HIGH-Z GAS TARGETS FIELDED AT OMEGA  

SciTech Connect

The authors report on modeling of x-ray yield from gas-filled targets shot at the OMEGA laser facility. The OMEGA targets were 1.8 mm long, 1.95 mm in diameter Be cans filled with either a 50:50 Ar:Xe mixture, pure Ar, pure Kr or pure Xe at {approx} 1 atm. The OMEGA experiments heated the gas with 20 kJ of 3{omega} ({approx} 350 nm) laser energy delivered in a 1 ns square pulse. the emitted x-ray flux was monitored with the x-ray diode based DANTE instruments in the sub-keV range. Two-dimensional x-ray images (for energies 3-5 keV) of the targets were recorded with gated x-ray detectors. The x-ray spectra were recorded with the HENWAY crystal spectrometer at OMEGA. Predictions are 2D r-z cylindrical with DCA NLTE atomic physics. Models generally: (1) underpredict the Xe L-shell yields; (2) overpredict the Ar K-shell yields; (3) correctly predict the Xe thermal yields; and (4) greatly underpredict the Ar thermal yields. However, there are spreads within the data, e.g. the DMX Ar K-shell yields are correctly predicted. The predicted thermal yields show strong angular dependence.

Kane, J O; Fournier, K B; May, M J; Colvin, J D; Thomas, C A; Marrs, R E; Compton, S M; Moody, J D; Bond, E J; Davis, J F

2010-11-04

350

PEG/Ion -Scoring Sheet 1. 0.2 M Sodium Fluoride, 20% PEG 3350  

E-print Network

Magnesium Chloride, 20% PEG 3350 6. 0.2 M Sodium Chloride, 20% PEG 3350 7. 0.2 M Calcium Chloride, 20% PEG 3350 3. 0.2 M Ammonium Fluoride, 20% PEG 3350 4. 0.2 M Lithium Chloride, 20% PEG 3350 5. 0.2 M 3350 8. 0.2 M Potassium Chloride, 20% PEG 3350 9. 0.2 M Ammonium Chloride, 20% PEG 3350 10. 0.2 M

Hill, Chris

351

DESIGNING HUMAN 2.0 (TRANSHUMAN) – REGENERATIVE EXISTENCE  

Microsoft Academic Search

This paper explores regenerative existence for Human 2.0 – the transhuman. In building this focus, the author addresses the use of emerging technologies as propitious in designing the amended, extended, and suspended human body. Here, a first focus covers emerging biotechnologies for regenerative existence, which play a large role in extreme life extension. A second focus covers the digital technologies

Natasha Vita-More

2008-01-01

352

2013 , 2013 2 20 ()-21 (), Multiple Kernel Deep Network  

E-print Network

PS-32 2013 , 2013 2 20 ()-21 (), Multiple Kernel Deep Network , , , KAIST Juhyeon Lee, Jae Hyun Lim, Dae-Shik Kim 1 Dept. of Electrical Engineering, KAIST E-mail: jhlee89@kaist.ac.kr, lim-0606@kaist.ac.kr, dskim@ee.kaist.ac.kr Abstract: Object recognition is one of the challenging problems

Kim, Dae-Shik

353

VOL 20 NO 2 Predicting the effect of accelerated  

E-print Network

5 VOL 20 NO 2 Predicting the effect of accelerated stability conditions on the intact tablets Using the ASAP 2020 water sorp- tion accessory, one can easily study the effect of accelerated stability- ity in energy of low surface area or non-porous materials, which are common in pharmaceutical

Natelson, Douglas

354

Outcome-Driven Experiential Learning with Web 2.0  

ERIC Educational Resources Information Center

Experiential learning, an effective pedagogical method in MIS and other business courses, has been limited by instructional formats and teaching resources. But with the advent of Web 2.0 and its rich set of social networking and mass authoring tools, a shift in learning structure in content, process, and outcome is emerging. In this paper, we…

Huang, C. Derrick; Behara, Ravi S.

2007-01-01

355

Web 2.0 for R&R  

ERIC Educational Resources Information Center

Are colleges and universities doing enough to take advantage of Web 2.0 and social networking tools in their recruitment and retention efforts? "Not even close," says Sam Richard, a 23-year-old junior in the College of Public Programs at Arizona State University in Phoenix. Richard is one of six students in ASU's Student Ambassadors for…

Raths, David

2009-01-01

356

MULTIPLE PROJECTS SYSTEM (MPS) VERSION 2.0 - USER'S MANUAL  

EPA Science Inventory

The document is a user's manual for Multiple Projections System (MPS) Version 2.0, based on the 3% reasonable further progress (RFP) tracking system that was developed in FY92/FY93. he 3% RFP tracking system is a Windows application, and enhancements to convert the 3% RFP trackin...

357

MULTIPLE PROJECTIONS SYSTEM (MPS): USER'S MANUAL VERSION 2.0  

EPA Science Inventory

The document is a user's manual for Multiple Projections System (MPS) Version 2.0, based on the 3% reasonable further progress (RFP) tracking system that was developed in FY92/FY93. The 3% RFP tracking system is a Windows application, and enhancements to convert the 3% RFP track...

358

Mapping COSA Software Architecture Concepts into UML 2.0  

Microsoft Academic Search

In this article we contribute to the issue of documenting architectural description with UML. Describing the architecture of a software system using UML notations is a tricky task due to the lack of explicit support for architectural description concepts. Thus, we try to define a strategy to map any ADL into UML, particularly UML 2.0. Our strategy is based on

Tahar Khammaci; A. Smeda; M. Oussalah

2006-01-01

359

PRISM 2.0: A Tool for Probabilistic Model Checking  

Microsoft Academic Search

This paper gives a brief overview of version 2.0 of PRISM, a tool for the automatic formal verification of probabilis- tic systems, and some of the case studies to which it has al- ready been applied. The use of probabilistic modelling for the analysis and verification of computer systems is becoming more and more widespread. Probabilistic model checkingis an auto-

Marta Z. Kwiatkowska; Gethin Norman; David Parker

2004-01-01

360

2. VIEW OF RUINS OF FINE ORE MILL (FEATURE 20), ...  

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

2. VIEW OF RUINS OF FINE ORE MILL (FEATURE 20), FACING NORTH-NORTHWEST. PORTION OF HEADFRAME AND STORAGE TANKS (FEATURE 18) VISIBLE IN UPPER RIGHT CORNER OF PHOTOGRAPH. - Copper Canyon Camp of the International Smelting & Refining Company, Ruins of the Fine Ore Mill, Copper Canyon, Battle Mountain, Lander County, NV

361

Web 2.0 Tools for Supporting Teaching  

ERIC Educational Resources Information Center

Web 2.0 tools provide enormous opportunities for teaching and learning, yet their application in education is still underdeveloped. What is more, it is no longer possible for teachers to ignore such a technological advance, while they are expected to provide students with opportunities to take control of their learning. However, teachers are still…

Konstantinidis, Angelos; Theodostadou, Dimitra; Pappos, Christos

2013-01-01

362

Webquest 2.0: An Instructional Model for Digital Learners  

ERIC Educational Resources Information Center

Teaching and learning tools such as Moodle and Web 2.0 tools are appearing in K-12 classrooms; however, there is a lack of scholarly research to guide the implementation of these tools. The WebQuest model, a widely adopted inquiry-based model for online instruction, has instructional inadequacies and does not make the most of emerging…

Dell, Diana F. Abernathy

2012-01-01

363

Conceptualising teachers' professional learning with Web 2.0  

Microsoft Academic Search

Purpose – This paper seeks to identify and develop an exploratory framework for conceptualising how teachers might use the affordances of Web 2.0 technologies to support their own professional learning. Design\\/methodology\\/approach – The paper draws on a large corpus of literature and recent research evidence to identify the principal elements and features of professional learning and the underlying affordances of

Kevin John Burden

2010-01-01

364

Carbon Cycle 2.0: Robert Cheng and Juan Meza  

SciTech Connect

Feb. 4, 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.

Robert Cheng and Juan Meza

2010-02-16

365

Carbon Cycle 2.0: Jay Keasling: Biofuels  

SciTech Connect

Feb. 4, 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.

Jay Keasling

2010-02-16

366

Carbon Cycle 2.0: Nitash Balsara: Energy Storage  

SciTech Connect

Feb. 4, 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.

Nitash Balsara

2010-02-16

367

Ethnography 2.0: Writing with Digital Video  

ERIC Educational Resources Information Center

This article investigates how digital video technology can be used in ethnographic research and considers the implications of digital production, presentation and dissemination of ethnographic educational research knowledge. In this article, I introduce the term Ethnography 2.0 and address some of the issues that emerged from my decision to use…

White, M. L.

2009-01-01

368

Water Resources Development, Vol. 20, No. 2, 193204, June 2004  

E-print Network

Water Resources Development, Vol. 20, No. 2, 193­204, June 2004 Towards a Middle East at Peace, OR, USA ABSTRACT When peace negotiations do one day resume between Israelis and Arabs, shared water hydrologic and political claims, and could threaten the entire approach to water negotiations both between

Wolf, Aaron

369

iPath2.0: interactive pathway explorer  

PubMed Central

iPath2.0 is a web-based tool (http://pathways.embl.de) for the visualization and analysis of cellular pathways. Its primary map summarizes the metabolism in biological systems as annotated to date. Nodes in the map correspond to various chemical compounds and edges represent series of enzymatic reactions. In two other maps, iPath2.0 provides an overview of secondary metabolite biosynthesis and a hand-picked selection of important regulatory pathways and other functional modules, allowing a more general overview of protein functions in a genome or metagenome. iPath2.0?s main interface is an interactive Flash-based viewer, which allows users to easily navigate and explore the complex pathway maps. In addition to the default pre-computed overview maps, iPath offers several data mapping tools. Users can upload various types of data and completely customize all nodes and edges of iPath2.0?s maps. These customized maps give users an intuitive overview of their own data, guiding the analysis of various genomics and metagenomics projects. PMID:21546551

Yamada, Takuji; Letunic, Ivica; Okuda, Shujiro; Kanehisa, Minoru; Bork, Peer

2011-01-01

370

Carbon Cycle 2.0: Nitash Balsara: Energy Storage  

ScienceCinema

Feb. 4, 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.

Nitash Balsara

2010-09-01

371

Journalism Students, Web 2.0 and the Digital Divide  

ERIC Educational Resources Information Center

The purpose of this study was to find out if students were utilizing Web 2.0 applications. Since the applications in question are often employed by the media industry, the study aspired to find out if students majoring in mass communication and journalism utilized the applications more often than other students. The "digital divide" is a term used…

Green, Mary Elizabeth

2009-01-01

372

Supporting productive integration of Web 2.0-mediated collaboration  

E-print Network

original model. The Science learning cycle model being inquiry-based represents an inductive application.tsoi@nie.edu.sg Abstract. This paper describes a research evidence-based practice model, TSOI Hybrid Learning Model as a viable alternative to support productive integration of Web 2.0-mediated collaboration for learning

Boyer, Edmond

373

Teaching Talented Writers with Web 2.0 Tools  

ERIC Educational Resources Information Center

This article is a review of 12 online writing resources and contains suggestions about how such resources might be used in a differentiated classroom with talented writers. Youth with writing talent are defined by distinguishing characteristics and the authors discuss how those characteristics can be supported and enhanced using Web 2.0 tools.…

Olthouse, Jill M.; Miller, Myriah Tasker

2012-01-01

374

Web 2.0 and Emerging Technologies in Online Learning  

ERIC Educational Resources Information Center

As online learning continues to grow, so do the free or nearly free Web 2.0 and emerging online learning technologies available to faculty and students. This chapter explores the implementation process and corresponding considerations of adapting such tools for teaching and learning. Issues addressed include copyright, intellectual property,…

Diaz, Veronica

2010-01-01

375

Changing Academic Teaching with Web 2.0 Technologies  

ERIC Educational Resources Information Center

Academic teaching can change with the use of Web 2.0 technologies, such as blogs and wikis, as these enable a different pedagogical approach through collaborative learning and the social construction of knowledge. Student expectations of their university learning experience have changed as they expect e-learning to be part of the learning…

Newland, Barbara; Byles, Linda

2014-01-01

376

Web 2.0 Technologies: Applications for Community Colleges  

ERIC Educational Resources Information Center

The current generation of new students, referred to as the Millennial Generation, brings a new set of challenges to the community college. The influx of these technologically sophisticated students, who interact through the social phenomenon of Web 2.0 technology, bring expectations that may reshape institutions of higher learning. This chapter…

Bajt, Susanne K.

2011-01-01

377

Social Work Information Center 2.0: A Case Study  

ERIC Educational Resources Information Center

The social work library at USC provides a case study of an academic library's transition to an information center service model. Analysis of the collection, user community, Web 2.0 applications, and Web usage data demonstrates how the changes facilitated library services and information literacy instruction. (Contains 6 tables and 3 figures.)

Xu, F. Grace

2009-01-01

378

Assessing E-Learning 2.0 System Success  

ERIC Educational Resources Information Center

Traditional e-learning systems support "one-way" communication. Teachers provide knowledge for learners, but they are unable to use a student's learning experiences to benefit the class as a whole. To address these problems, this study explores e-learning success factors via the design and evaluation of an e-learning 2.0 system. This study…

Wang, Hei Chia; Chiu, Yi Fang

2011-01-01

379

Special Issue Synthetic Cell Biology Cell Biology 2.0  

E-print Network

Special Issue ­ Synthetic Cell Biology Cell Biology 2.0 Wendell A. Lim1 , Rebecca Alvania3-2200, USA 3 Editor, Trends in Cell Biology `Verum esse ipsum factum', the true is in the made ­ Giambattista Vico Synthetic Cell Biology sounds intriguing, but the name begs the question ­ why should we try

Lim, Wendell

380

Librarians 2.0: Sowing Padi in (the) SEA  

ERIC Educational Resources Information Center

Purpose: The purpose of this paper is to present an exploratory survey as part of a presentation for the Bridging Worlds 2008 conference. It seeks to understand how library institutions in the South East Asia (SEA) region have implemented Web 2.0 technologies--blogs, RSS feeds, wikis, or the use of services like Flickr, YouTube, de.lici.ous.…

Chew, Ivan

2009-01-01

381

Data-Based Decision Making 2.0  

ERIC Educational Resources Information Center

The phrase "data-based decision making" has been used so often in discussions about school improvement efforts that it has become almost a mantra. However, it's "how" data is used that really provides the critical link between practice and school improvement. "Data-Based Decision Making 2.0" is designed to help principals take on the role of…

Protheroe, Nancy

2011-01-01

382

Carbon Cycle 2.0: Jay Keasling: Biofuels  

ScienceCinema

Feb. 4, 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.

Jay Keasling

2010-09-01

383

CDF/PHYS/PUB/CDF6057 Version 2.0  

E-print Network

CDF/PHYS/PUB/CDF6057 Version 2.0 June 29, 2003 Predicted Cross sections for W , W , Z , and Z the total production cross-section and also the `visible' CDF cross- section before and after parton-fragmentation and radiation by the shower Monte Carlos. These are analysis-level cuts. The parameters for the three analysis

384

Conceptualising Teachers' Professional Learning with Web 2.0  

ERIC Educational Resources Information Center

Purpose: This paper seeks to identify and develop an exploratory framework for conceptualising how teachers might use the affordances of Web 2.0 technologies to support their own professional learning. Design/methodology/approach: The paper draws on a large corpus of literature and recent research evidence to identify the principal elements and…

Burden, Kevin John

2010-01-01

385

Social Dimension of Web 2.0 in Engineering Education  

ERIC Educational Resources Information Center

Contemporary engineers need to become more cognizant and more responsive to the emerging needs of the market for engineering and technology services. Social dimension of Web 2.0 which penetrates our society more thoroughly with the availability of broadband services has the potential to contribute decisively to the sustainable development of…

Ahrens, Andreas; Zascerinska, Jelena

2010-01-01

386

Construct Personal Learning Environment Based on Web2.0  

Microsoft Academic Search

This paper explains some of the ideals and characters about PLE (personal learning environment). And introduce web2.0 social software and technology to construct PLE, where there is the difficulty for learners to integrate these dispersive tools and technologies. So it proposes a framework for an open source Personal Learning Environment which is called PLEF. The emphasis is on the process

Feng Wang; Xiayuan Li; Chengling Zhao; Chunyan Xu

2009-01-01

387

Flickr: a case study of Web2.0  

Microsoft Academic Search

Purpose – The “photosharing” site Flickr is one of the most commonly cited examples used to define Web2.0. This paper aims to explore where Flickr's real novelty lies, examining its functionality and its place in the world of amateur photography. Several optimistic views of the impact of Flickr such as its facilitation of citizen journalism, “vernacular creativity” and in learning

Andrew M. Cox

2008-01-01

388

Integrating Web 2.0 across the Curriculum  

ERIC Educational Resources Information Center

For many years, educators have touted the benefits of learning with educational tools such as spreadsheets and databases that allow students to actively process and manipulate information (Jonassen, 1995). Hundreds if not thousands of Web 2.0 tools have been created in the last few years, taking the "technology as tool" metaphor to a new level. In…

Oliver, Kevin

2010-01-01

389

Experience of Integrating Web 2.0 Technologies  

ERIC Educational Resources Information Center

Web users in the 21st century are no longer only passive consumers. On a contrary, they are active contributors willing to obtain, share and evolve information. In this paper we report our experience regarding the implementation of Web 2.0 concept in several Computer Ethics related courses jointly conducted at two Universities. These courses have…

Zdravkova, Katerina; Ivanovic, Mirjana; Putnik, Zoran

2012-01-01

390

RefWorks 2.0 (revised Aug. 2011)  

E-print Network

© RefWorks-COS, A Business Unit of ProQuest LLC Introduction The workbook is designed to guide users Workbook Page 3 © RefWorks-COS, A Business Unit of ProQuest LLC Task 1: Advanced Searching Task 2: Using reference. #12;RefWorks 2.0 Advanced User Workbook Page 4 © RefWorks-COS, A Business Unit of ProQuest LLC

University of Technology, Sydney

391

Short-Range Magnetic Correlations and Parimagnetism in RCo2  

SciTech Connect

X-ray circular magnetic dichroism, polarized neutron diffraction, ac susceptibility, and Seebeck effect have been measured for several members of the RCo2 series (R=Ho, Tm, Er) as a function of temperature and applied magnetic field. The experimental results show robust parimagnetism (a general behaviour along the RCo2 series with R being a heavy rare earth ion) and two reversal temperatures in some systems, which is an unexpected result. Polarised neutron diffraction show differences between results obtained on single crystals or polycrystalline ingots. We propose an interpretation of parimagnetic RCo2 as a Griffiths phase of the high temperature, magnetically ordered, amorphous RCo2 phase. Copyright EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2013

Bartolome, F. [CSIC - Universidad de Zaragoza; Bonilla, C. M. [CSIC - Universidad de Zaragoza; Herrero-Albillos, J. [CSIC - Universidad de Zaragoza; Calvo-Almazan, I. [CSIC - Universidad de Zaragoza; Castan, C. [CSIC - Universidad de Zaragoza; Weschke, E. [Helmholtz-Zentrum Berlin fur Materialien und Energie GmbH; Schmitz, D. [Helmholtz-Zentrum Berlin fur Materialien und Energie GmbH; Paudyal, Durga [Ames Laboratory; Mudryk, Yaroslav [Ames Laboratory; Pecharsky, Vitalij [Ames Laboratory; Gschneidner Jr., Karl A. [Ames Laboratory; Stunault, A. [Institut Laue-Langevin; Garcia, L. M. [CSIC - Universidad de Zaragoza

2013-12-02

392

Developing the World Health Organization Disability Assessment Schedule 2.0  

PubMed Central

Abstract Objective To describe the development of the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) for measuring functioning and disability in accordance with the International Classification of Functioning, Disability and Health. WHODAS 2.0 is a standard metric for ensuring scientific comparability across different populations. Methods A series of studies was carried out globally. Over 65?000 respondents drawn from the general population and from specific patient populations were interviewed by trained interviewers who applied the WHODAS 2.0 (with 36 items in its full version and 12 items in a shortened version). Findings The WHODAS 2.0 was found to have high internal consistency (Cronbach's alpha, ?: 0.86), a stable factor structure; high test-retest reliability (intraclass correlation coefficient:?0.98); good concurrent validity in patient classification when compared with other recognized disability measurement instruments; conformity to Rasch scaling properties across populations, and good responsiveness (i.e. sensitivity to change). Effect sizes ranged from 0.44 to 1.38 for different health interventions targeting various health conditions. Conclusion The WHODAS 2.0 meets the need for a robust instrument that can be easily administered to measure the impact of health conditions, monitor the effectiveness of interventions and estimate the burden of both mental and physical disorders across different populations. PMID:21076562

Chatterji, Somnath; Kostanjsek, Nenad; Rehm, Jürgen; Kennedy, Cille; Epping-Jordan, Joanne; Saxena, Shekhar; von Korff, Michael; Pull, Charles

2010-01-01

393

Active Transport Can Greatly Enhance Cdc20:Mad2 Formation  

PubMed Central

To guarantee genomic integrity and viability, the cell must ensure proper distribution of the replicated chromosomes among the two daughter cells in mitosis. The mitotic spindle assembly checkpoint (SAC) is a central regulatory mechanism to achieve this goal. A dysfunction of this checkpoint may lead to aneuploidy and likely contributes to the development of cancer. Kinetochores of unattached or misaligned chromosomes are thought to generate a diffusible “wait-anaphase” signal, which is the basis for downstream events to inhibit the anaphase promoting complex/cyclosome (APC/C). The rate of Cdc20:C-Mad2 complex formation at the kinetochore is a key regulatory factor in the context of APC/C inhibition. Computer simulations of a quantitative SAC model show that the formation of Cdc20:C-Mad2 is too slow for checkpoint maintenance when cytosolic O-Mad2 has to encounter kinetochores by diffusion alone. Here, we show that an active transport of O-Mad2 towards the spindle mid-zone increases the efficiency of Mad2-activation. Our in-silico data indicate that this mechanism can greatly enhance the formation of Cdc20:Mad2 and furthermore gives an explanation on how the “wait-anaphase” signal can dissolve abruptly within a short time. Our results help to understand parts of the SAC mechanism that remain unclear. PMID:25338047

Ibrahim, Bashar; Henze, Richard

2014-01-01

394

RSA/Legacy Wind Sensor Comparison. Part 2; Eastern Range  

NASA Technical Reports Server (NTRS)

This report describes a comparison of data from ultrasonic and propeller-and-vane anemometers on 5 wind towers at Kennedy Space Center and Cape Canaveral Air Force Station. The ultrasonic sensors are scheduled to replace the Legacy propeller-and-vane sensors under the Range Standardization and Automation (RSA) program. Because previous studies have noted differences between peak wind speeds reported by mechanical and ultrasonic wind sensors, the latter having no moving parts, the 30th and 45th Weather Squadrons wanted to understand possible differences between the two sensor types. The period-of-record was 13-30 May 2005, A total of 357,626 readings of 1-minute average and peak wind speed/direction from each sensor type were used. Statistics of differences in speed and direction were used to identify 15 out of 19 RSA sensors having the most consistent performance, with respect to the Legacy sensors. RSA average wind speed data from these 15 showed a small positive bias of 0.38 kts. A slightly larger positive bias of 0.94 kts was found in the RSA peak wind speed.

Short, David A.; Wheeler, Mark M.

2006-01-01

395

Viscosity, density, and surface tension of binary mixtures of water and N-methyldiethanolamine and water and diethanolamine and tertiary mixtures of these amines with water over the temperature range 20--100[degree]C  

SciTech Connect

Aqueous solutions of N-methyldiethanolamine (MDEA) and diethanolamine (DEA) are widely used in the industrial treatment of acid gas streams containing H[sub 2]S and CO[sub 2]. The density and viscosity of aqueous solutions of N-methyldiethanolamine were measured over the temperature range 60--100 C. The density and viscosity of aqueous solutions of diethanolamine and diethanolamine + N-methyldiethanolamine were measured over the temperature range 20--100 C. The surface tension of aqueous solutions of the above mixtures was measured over the temperature range 20--80 C. The concentration ranges were 10--50 mass % N-methyldiethanolamine, 10--30 mass % diethanolamine, and 50 mass % total amine concentration with mass ratios of 0.0441--0.5883 (diethanolamine to N-methyldiethanolamine). The measured quantities were found to be in agreement with the literature where data were available.

Rinker, E.B.; Oelschlager, D.W.; Colussi, A.T.; Henry, K.R.; Sandall, O.C. (Univ. of California, Santa Barbara, CA (United States). Dept. of Chemical and Nuclear Engineering)

1994-04-01

396

Einfhrung in Web 2.0-Dienste / Voss, Jakob. Workshop Leipzig : MPI, 2007-09-06 Web 2.0-Anwendungen  

E-print Network

Einführung in Web 2.0-Dienste / Voss, Jakob. Workshop ­ Leipzig : MPI, 2007-09-06 Web 2.0-Anwendungen für Bibliothekare #12;Einführung in Web 2.0-Dienste / Voss, Jakob. Workshop ­ Leipzig : MPI, 2007-09-06 Inhalt Web 2.0 Trends und Prinzipien Beispiele #12;Einführung in Web 2.0-Dienste / Voss, Jakob

397

Preparing Teachers to Integrate Web 2.0 in School Practice: Toward a Framework for Pedagogy 2.0  

ERIC Educational Resources Information Center

Web 2.0 has captured the interest and the imagination of both educators and researchers while it is expected to exert a significant impact on instruction and learning, in the context of the 21st century education. Hailed as an open collaborative learning space, many questions remain unanswered regarding the appropriate teacher preparation and the…

Jimoyiannis, Athanassios; Tsiotakis, Panagiotis; Roussinos, Dimitrios; Siorenta, Anastasia

2013-01-01

398

Has Web 2.0 Revitalized Informal Learning? The Relationship between Web 2.0 and Informal Learning  

ERIC Educational Resources Information Center

Learning is becoming increasingly self-directed and often occurs away from schools and other formal educational settings. The development of a myriad of new technologies for learning has enabled people to learn anywhere and anytime. Web 2.0 technology allows researchers to shed a new light on the importance and prevalence of informal learning.…

Song, D.; Lee, J.

2014-01-01

399

Stopping of 5-100 keV helium in molybdenum, chromium, copper and nickel  

NASA Astrophysics Data System (ADS)

The stopping power of Mo, Cr, Cu and Ni for He ions at velocities below the Bohr velocity has been studied. The stopping power values were deduced by comparing ranges of 5-100 keV He(+) -ions determined with the elastic-recoil-detection-analysis (ERDA) method with those obtained in molecular dynamics simulations. The nuclear slowing down was treated through the use of molecular dynamics calculations and a potential obtained from density-functional theory calculations. The comparisons of the range profiles showed that the electronic stopping powers given by J.F. Ziegler, J.P. Biersack and U. Littmark (The Stopping Powers and Ranges of Ions in Matter, vol. 1, Pergamon press, New York, 1985) had to be multiplied with a factor of 1.20 ± 0.07 for Mo and Cr and 1.00 ± 0.06 for Cu and Ni.

Sillanpää, J.; Vainonen-Ahlgren, E.; Haussalo, P.; Keinonen, J.

1998-06-01

400

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

Code of Federal Regulations, 2014 CFR

...ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS...mining range area. (a) The danger zone. Within an area bounded as follows: Beginning at...during test periods to insure that no surface vessels are within the...

2014-07-01

401

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

Code of Federal Regulations, 2010 CFR

...ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS...mining range area. (a) The danger zone. Within an area bounded as follows: Beginning at...during test periods to insure that no surface vessels are within the...

2010-07-01

402

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

Code of Federal Regulations, 2013 CFR

...ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS...mining range area. (a) The danger zone. Within an area bounded as follows: Beginning at...during test periods to insure that no surface vessels are within the...

2013-07-01

403

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

Code of Federal Regulations, 2012 CFR

...ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS...mining range area. (a) The danger zone. Within an area bounded as follows: Beginning at...during test periods to insure that no surface vessels are within the...

2012-07-01

404

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

Code of Federal Regulations, 2011 CFR

...ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS...mining range area. (a) The danger zone. Within an area bounded as follows: Beginning at...during test periods to insure that no surface vessels are within the...

2011-07-01

405

PSEUDOMARKER 2.0: efficient computation of likelihoods using NOMAD  

PubMed Central

Background PSEUDOMARKER is a software package that performs joint linkage and linkage disequilibrium analysis between a marker and a putative disease locus. A key feature of PSEUDOMARKER is that it can combine case-controls and pedigrees of varying structure into a single unified analysis. Thus it maximizes the full likelihood of the data over marker allele frequencies or conditional allele frequencies on disease and recombination fraction. Results The new version 2.0 uses the software package NOMAD to maximize likelihoods, resulting in generally comparable or better optima with many fewer evaluations of the likelihood functions. Conclusions After being modified substantially to use modern optimization methods, PSEUDOMARKER version 2.0 is more robust and substantially faster than version 1.0. NOMAD may be useful in other bioinformatics problems where complex likelihood functions are optimized. PMID:24533837

2014-01-01

406

Tool interoperability in SSE OI 2.0  

NASA Technical Reports Server (NTRS)

This paper presents a review of the concept and implementation of tool interoperability in the Space Station Software Support Environment (SSE) OI 2.0. By first providing a description of SSE, the paper describes the problem at hand, that is; the nature of the SSE that gives rise to the requirement for interoperability--between SSE workstations and hence, between the tools which reside on the workstations. Specifically, word processor and graphic tool interoperability are discussed. The concept for interoperability that is implemented in OI 2.0 is described, as is an overview of the implementation strategy. Some of the significant challenges that the development team had to overcome to bring about interoperability are described, perhaps as a checklist, or warning, to others who would bring about tool interoperability. Lastly, plans to extend tool interoperability to a third class of tools in OI 3.0 are described.

Carmody, C. L.; Shotton, C. T.

1988-01-01

407

HEP Outreach, Inreach, and Web 2.0  

NASA Astrophysics Data System (ADS)

I report on current usage of multimedia and social networking "Web 2.0" tools for Education and Outreach in high-energy physics, and discuss their potential for internal communication within large worldwide collaborations, such as those of the LHC. Following a brief description of the history of Web 2.0 development, I present a survey of the most popular sites and describe their usage in HEP to disseminate information to students and the general public. I then discuss the potential of certain specific tools, such as document and multimedia sharing sites, for boosting the speed and effectiveness of information exchange within the collaborations. I conclude with a brief discussion of the successes and failures of these tools, and make suggestions for improved usage in the future.

Goldfarb, Steven

2011-12-01

408

AFCI-2.0 Library of Neutron Cross Section Covariances  

SciTech Connect

Neutron cross section covariance library has been under development by BNL-LANL collaborative effort over the last three years. The primary purpose of the library is to provide covariances for the Advanced Fuel Cycle Initiative (AFCI) data adjustment project, which is focusing on the needs of fast advanced burner reactors. The covariances refer to central values given in the 2006 release of the U.S. neutron evaluated library ENDF/B-VII. The preliminary version (AFCI-2.0beta) has been completed in October 2010 and made available to the users for comments. In the final 2.0 release, covariances for a few materials were updated, in particular new LANL evaluations for {sup 238,240}Pu and {sup 241}Am were adopted. BNL was responsible for covariances for structural materials and fission products, management of the library and coordination of the work, while LANL was in charge of covariances for light nuclei and for actinides.

Herman, M.; Herman,M.; Oblozinsky,P.; Mattoon,C.; Pigni,M.; Hoblit,S.; Mughabghab,S.F.; Sonzogni,A.; Talou,P.; Chadwick,M.B.; Hale.G.M.; Kahler,A.C.; Kawano,T.; Little,R.C.; Young,P.G.

2011-06-26

409

Ontologies pour le Web 2.0 Alexandre Passant1,2  

E-print Network

Ontologies pour le Web 2.0 Alexandre Passant1,2 , Philippe Laublet1 (1) LaLIC, Universit´e Paris du Web 2.0 et du Web S´emantique, cet article pr´esente en quoi ces deux visions du Web ne sont selon Web 2.0 et celui du peuplement d'on- tologie `a partir de wikis. Nous nous appuierons pour cela sur la

Boyer, Edmond

410

Some User's Insights Into ADIFOR 2.0D  

NASA Technical Reports Server (NTRS)

Some insights are given which were gained by one user through experience with the use of the ADIFOR 2.0D software for automatic differentiation of Fortran code. These insights are generally in the area of the user interface with the generated derivative code - particularly the actual form of the interface and the use of derivative objects, including "seed" matrices. Some remarks are given as to how to iterate application of ADIFOR in order to generate second derivative code.

Giesy, Daniel P.

2002-01-01

411

HoneySpam 2.0: Profiling Web Spambot Behaviour  

Microsoft Academic Search

Internet bots have been widely used for various beneficial and malicious activities on the web. In this paper we provide new\\u000a insights into a new kind of bot termed as web spambot which is primarily used for spreading spam content on the web. To gain insights into web spambots, we developed a tool (HoneySpam\\u000a 2.0) to track their behaviour. This

Pedram Hayati; Kevin Chai; Vidyasagar Potdar; Alex Talevski

2009-01-01

412

Web2.0 Tools to Support the Instructional Method \\  

Microsoft Academic Search

This research aims at improving the instructional method ldquoThinking actively in a creative environmentrdquo TACE with Web2.0 based tools. These tools we have developed enable the participation of many people in idea generation and evaluation sessions forming brainstorming networks. They also allow the formation of innovation development teams based on the affinity among the participants for their creativity and their

Oscar Ardaiz-villanueva; Xabier Nicuesa Chacón; Oscar Brene Artazcoz; María Luisa Sanz De Acedo Lizarraga; María Teresa Sanz De Acedo Baquedano

2009-01-01

413

Web2.0 digital panoramic geological field practice base  

Microsoft Academic Search

Geological field practice is a necessary part of the teaching in geology related. Digital panoramic geological field practice base is designed based on B\\/S model, using Web2.0 technology and panoramic images to archive real geological field environment. Take Xingcheng geological field practice base of Jilin University as the demonstration, established Xingcheng digital panoramic geological field practice base, the system providing

Wang Man; Xue Linfu; Deng Chunyan; Wang Yingwei; Li Wenqing

2010-01-01

414

Towards federated Web2.0 sites: the TAGMAS approach  

Microsoft Academic Search

The success of Web2.0 is draining user's resources from the desk- top to the Web. An increasing number of users are keeping their pictures at ic kr, their bookmarks at del.icio.us, their documents at googleDocs and so on. There are important advantages to be gained, but this dissemination of user's resources should go hand- by-hand with tooling that permits users

Jon Iturrioz

2007-01-01

415

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

NASA Technical Reports Server (NTRS)

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.

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

1978-01-01

416

An overview of MATISSE-v2.0  

NASA Astrophysics Data System (ADS)

MATISSE which acronym means Advanced Modeling of the Earth for Environment and Scenes Simulation is an infrared background scene generator developed by Onera since the mid 1990'. MATISSE main goal is to compute radiance images of natural backgrounds and radiative quantities such as local illumination, spectral transmission, and spectral radiance along lines of sight. The new version MATISSE-v2.0 has been completed during the first quarter of 2010 and the public version is going to be released in few weeks. This latest version uses a multi resolution spatial scheme in order to treat the natural backgrounds with spatial footprint from kilometre sizes (satellite viewing) down to metric sizes. Up to now, this spatial scheme has been used in order to generate infrared images of sea surface. The new sea surface model (water waves and surface optical properties) has been partially validated by using a specific Mediterranean campaign. MATISSE-v2.0 is also accompanied with a new set of GUI (graphical user interface) in order to help the user in defining its computational case. The code is also designed in order to be interfaced with other applications. Our presentation will be devoted to a description of MATISSE-v2.0 new features, with examples of sea surface scenes exemplifying the new code functionalities.

Labarre, Luc; Caillault, Karine; Fauqueux, Sandrine; Malherbe, Claire; Roblin, Antoine; Rosier, Bernard; Simoneau, Pierre

2010-10-01

417

Neutron scattering and scaling behavior in URu2Zn20 and YbFe2Zn20 C. H. Wang1,2  

E-print Network

Neutron scattering and scaling behavior in URu2Zn20 and YbFe2Zn20 C. H. Wang1,2 , A. D susceptibility (E), measured by inelastic neutron scattering measurements, shows a broad peak centered at Emax of the neutron scattering spectra (E) of polycrystalline samples[5]. The theoretical calculations[1­4] show

Lawrence, Jon

418

Cartographic Perspectives, Number 64, Fall 2009 Cartography 2.0: For People Who Make Interactive Maps -Harrower | 41 Cartography 2.0: For people who make interactive maps  

E-print Network

Cartographic Perspectives, Number 64, Fall 2009 Cartography 2.0: For People Who Make Interactive Maps - Harrower | 41 Cartography 2.0: For people who make interactive maps Prof. Mark Harrower 1 Sheesely 2 | ben@axismaps.com Cartography 2.0 (http://Cartography2.org) is a free online knowledge base

Klippel, Alexander

419

Accurate Measurement of Ferrite Garnets to be used for Fast-Tuned loaded cavities in the range of 20-40 MHZ  

E-print Network

For the implementation of ferrite-tuned cavities with orthogonally biased ferrites in the frequency range of 20- 40 MHz, different types of ferrite garnets were evaluated in terms of their electromagnetic properties. This paper describes a precision measurement method applicable to small-sized ferrite samples of 1-square-inch surface and 1.8 mm thickness in the given frequency range by means of a one-port reflection method. The material samples are exposed to a magnetic bias field range with different orientations. We present a detailed description of this technique as well as material results obtained.

Vollinger, C

2012-01-01

420

Research, Collaboration, and Open Science Using Web 2.0  

PubMed Central

There is little doubt that the Internet has transformed the world in which we live. Information that was once archived in bricks and mortar libraries is now only a click away, and people across the globe have become connected in a manner inconceivable only 20 years ago. Although many scientists and educators have embraced the Internet as an invaluable tool for research, education and data sharing, some have been somewhat slower to take full advantage of emerging Web 2.0 technologies. Here we discuss the benefits and challenges of integrating Web 2.0 applications into undergraduate research and education programs, based on our experience utilizing these technologies in a summer undergraduate research program in synthetic biology at Harvard University. We discuss the use of applications including wiki-based documentation, digital brainstorming, and open data sharing via the Web, to facilitate the educational aspects and collaborative progress of undergraduate research projects. We hope to inspire others to integrate these technologies into their own coursework or research projects. PMID:23653712

Shee, Kevin; Strong, Michael; Guido, Nicholas J.; Lue, Robert A.; Church, George M.; Viel, Alain

2010-01-01

421

Measuring and Analyzing the Openness of the Web2.0 Service Network for Improving the Innovation Capacity of the Web2.0 System through Collective Intelligence  

Microsoft Academic Search

\\u000a Web2.0 users can create new services by combining existing Web2.0 services that offer open programming interfaces. This system\\u000a of service composition forms a network, which we call the Web2.0 service network. A node of the Web2.0 service network represents\\u000a a service. A link between two nodes exists, if another Web2.0 service (i.e. mashup) uses the linked services. The Web2.0 service

Kibae Kim; Jörn Altmann; Junseok Hwang

2010-01-01

422

The NERC Vocabulary Server: Version 2.0  

NASA Astrophysics Data System (ADS)

The Natural Environment Research Council (NERC) Vocabulary Server (NVS) has been used to publish controlled vocabularies of terms relevant to marine environmental sciences since 2006 (version 0) with version 1 being introduced in 2007. It has been used for - metadata mark-up with verifiable content - populating dynamic drop down lists - semantic cross-walk between metadata schemata - so-called smart search - and the semantic enablement of Open Geospatial Consortium (OGC) Web Processing Services in the NERC Data Grid and the European Commission SeaDataNet, Geo-Seas, and European Marine Observation and Data Network (EMODnet) projects. The NVS is based on the Simple Knowledge Organization System (SKOS) model. SKOS is based on the "concept", which it defines as a "unit of thought", that is an idea or notion such as "oil spill". Following a version change for SKOS in 2009 there was a desire to upgrade the NVS to incorporate the changes. This version of SKOS introduces the ability to aggregate concepts in both collections and schemes. The design of version 2 of the NVS uses both types of aggregation: schemes for the discovery of content through hierarchical thesauri and collections for the publication and addressing of content. Other desired changes from version 1 of the NVS included: - the removal of the potential for multiple identifiers for the same concept to ensure consistent addressing of concepts - the addition of content and technical governance information in the payload documents to provide an audit trail to users of NVS content - the removal of XML snippets from concept definitions in order to correctly validate XML serializations of the SKOS - the addition of the ability to map into external knowledge organization systems in order to extend the knowledge base - a more truly RESTful approach URL access to the NVS to make the development of applications on top of the NVS easier - and support for multiple human languages to increase the user base of the NVS Version 2 of the NVS (NVS2.0) underpins the semantic layer for the Open Service Network for Marine Environmental Data (NETMAR) project, funded by the European Commission under the Seventh Framework Programme. Within NETMAR, NVS2.0 has been used for: - semantic validation of inputs to chained OGC Web Processing Services - smart discovery of data and services - integration of data from distributed nodes of the International Coastal Atlas Network Since its deployment, NVS2.0 has been adopted within the European SeaDataNet community's software products which has significantly increased the usage of the NVS2.0 Application Programming Interace (API), as illustrated in Table 1. Here we present the results of upgrading the NVS to version 2 and show applications which have been built on top of the NVS2.0 API, including a SPARQL endpoint and a hierarchical catalogue of oceanographic hardware.Table 1. NVS2.0 API usage by month from 467 unique IP addressest;

Leadbetter, A. M.; Lowry, R. K.

2012-12-01

423

Effect of the electropositive elements A = Sc, La, and Ce on the microscopic dynamics of AV2Al20.  

PubMed

We report on the inelastic response of AV2Al20 (with A = Sc, La and Ce) probed by high-resolution inelastic neutron scattering experiments. Intense signals associated with the dynamics of Sc, La and Ce are identified in the low-energy range at 6-14 meV in ScV2Al20 and at 8-16 meV in LaV2Al20 and CeV2Al20. Their response to temperature changes between 2 and 300 K reveals a very weak softening of the modes upon heating in LaV2Al20 and CeV2Al20 and a distinguished blue shift by about 2 meV in ScV2Al20. By means of density functional theory (DFT) and lattice dynamics calculations (LDC) we show that the unusual anharmonicity of the Sc-dominated modes is due to the local potential of Sc featured by a strong quartic term. The vibrational dynamics of ScV2Al20 as well as of LaV2Al20 and CeV2Al20 is reproduced by a set of eigenmodes. To screen the validity of the DFT and LDC results they are confronted with data from X-ray diffraction measurements. The effect of the strong phonon renormalization in ScV2Al20 on thermodynamic observables is computed on grounds of the LDC derived inelastic response. To set the data in a general context of AV2Al20 compounds and their physical properties we report in addition computer and experimental results of the binary V2Al20 compound. PMID:25388502

Koza, Michael Marek; Leithe-Jasper, Andreas; Sischka, Erik; Schnelle, Walter; Borrmann, Horst; Mutka, Hannu; Grin, Yuri

2014-12-28

424

A genetically encoded sensor for H2O2 with expanded dynamic range.  

PubMed

Hydrogen peroxide is an important second messenger controlling intracellular signaling cascades by selective oxidation of redox active thiolates in proteins. Changes in intracellular [H(2)O(2)] can be tracked in real time using HyPer, a ratiometric genetically encoded fluorescent probe. Although HyPer is sensitive and selective for H(2)O(2) due to the properties of its sensing domain derived from the Escherichia coli OxyR protein, many applications may benefit from an improvement of the indicator's dynamic range. We here report HyPer-2, a probe that fills this demand. Upon saturating [H(2)O(2)] exposure, HyPer-2 undergoes an up to sixfold increase of the ratio F500/F420 versus a threefold change in HyPer. HyPer-2 was generated by a single point mutation A406V from HyPer corresponding to A233V in wtOxyR. This mutation was previously shown to destabilize interface between monomers in OxyR dimers. However, in HyPer-2, the A233V mutation stabilizes the dimer and expands the dynamic range of the probe. PMID:20692175

Markvicheva, Kseniya N; Bilan, Dmitry S; Mishina, Natalia M; Gorokhovatsky, Andrey Yu; Vinokurov, Leonid M; Lukyanov, Sergey; Belousov, Vsevolod V

2011-02-01

425

Study of medicine 2.0 due to Web 2.0?! - Risks and opportunities for the curriculum in Leipzig  

PubMed Central

Web 2.0 is changing the study of medicine by opening up totally new ways of learning and teaching in an ongoing process. Global social networking services like Facebook, YouTube, Flickr, Google Drive and Xing already play an important part in communication both among students and between students and teaching staff. Moreover, local portals (such as the platform [http://www.leipzig-medizin.de] established in 2003) have also caught on and in some cases eclipsed the use of the well-known location-independent social media. The many possibilities and rapid changes brought about by social networks need to be publicized within medical faculties. Therefore, an E-learning and New Media Working Group was set up at the Faculty of Medicine of Universität Leipzig in order to harness the opportunities of Web 2.0, analyse the resulting processes of change in the study of medicine, and curb the risks of the Internet. With Web 2.0 and the social web already influencing the study of medicine, the opportunities of the Internet now need to be utilized to improve the teaching of medicine. PMID:23467440

Hempel, Gunther; Neef, Martin; Rotzoll, Daisy; Heinke, Wolfgang

2013-01-01

426

Study of medicine 2.0 due to Web 2.0?! -- risks and opportunities for the curriculum in Leipzig.  

PubMed

Web 2.0 is changing the study of medicine by opening up totally new ways of learning and teaching in an ongoing process. Global social networking services like Facebook, YouTube, Flickr, Google Drive and Xing already play an important part in communication both among students and between students and teaching staff. Moreover, local portals (such as the platform [http://www.leipzig-medizin.de] established in 2003) have also caught on and in some cases eclipsed the use of the well-known location-independent social media. The many possibilities and rapid changes brought about by social networks need to be publicized within medical faculties. Therefore, an E-learning and New Media Working Group was set up at the Faculty of Medicine of Universität Leipzig in order to harness the opportunities of Web 2.0, analyse the resulting processes of change in the study of medicine, and curb the risks of the Internet. With Web 2.0 and the social web already influencing the study of medicine, the opportunities of the Internet now need to be utilized to improve the teaching of medicine. PMID:23467440

Hempel, Gunther; Neef, Martin; Rotzoll, Daisy; Heinke, Wolfgang

2013-01-01

427

Range Resolved CO2 Atmospheric Backscattering Measurements Using Fiber Lasers and RZPN Code Modulation  

NASA Technical Reports Server (NTRS)

We report the use of a return-to- zero (RZPN) pseudo noise modulation technique for making range resolved measurements of CO2 within the planetary boundary layer (PBL) using commercial, off-the-shelf, components. Conventional, range resolved, DIAL measurements require laser pulse widths that are significantly shorter than the desired spatial resolution and necessitate using pulses whose temporal spacing is such that scattered returns from only a single pulse are observed by the receiver at any one time (for the PBL pulse separations must be greater than approximately 20 microseconds). This imposes significant operational limitations when using currently available fiber lasers because of the resulting low duty cycle (less than approximately 0.0005) and consequent low average laser output power. The RZPN modulation technique enables a fiber laser to operate at much higher duty cycles (approaching 0.04) thereby more effectively utilizing the amplifier's output. This increases the counts received by approximately two orders of magnitude. Our approach involves employing two distributed feedback lasers (DFB), each modulated by a different RPZN code, whose outputs are then amplified by a CW fiber amplifier. One laser is tuned to a CO2 absorption line; the other operates offline thereby permitting the simultaneous acquisition of both on and offline signals using independent RZPN codes. This minimizes the impact of atmospheric turbulence on the measurement. The on and offline signals are retrieved by deconvolving the return signal using the appropriate kernels.

Burris, John

2011-01-01

428

Harnessing Learner's Collective Intelligence: A Web2.0 Approach to E-Learning  

Microsoft Academic Search

Today, learners have access to a wide range of sources where they regularly search for, find and use learning resources outside\\u000a the scope of regular course material. Although E-learning systems offer a variety of tools and functionalities, there are\\u000a no specific provisions for learners to easily store and share these valuable resources. In this work we present SHAREK, a\\u000a Web2.0

Hicham Hage; Esma Aïmeur

2008-01-01

429

Measurements of the viscosity of new refrigerants in the temperature range 270 340 K at pressures up to 20 MPa  

NASA Astrophysics Data System (ADS)

A recently modified vibrating-wire instrument was employed to measure the liquid viscosity of a wide selection of new refrigerants under pressure. Calibration of the viscometer with water over the range of measurements confirmed that the estimated uncertainty of the measurements is 0.5%, while the precision is 0.3%. With this instrument, the viscosity of chlorofuorocarbons (CFC's) and alternative refrigerants. R11. R12. R22, R32. R124, R125. 11134a. R 141 b, and R152a, was measured over the temperature range from 270 to 340 K, from just above the saturation pressure up to 211 M Pa. The experimental data, represented by polynomial functions of temperature and pressure, are used in a comparative examination of other recently reported experimental measurements of the viscosity of all these refrigerants. to investigate the uncertainty with which the viscosity is known.

Assael, M. J.; Karagiannidis, L.; Polimatidou, S. K.

1995-01-01

430

SCOR: Structural classification of RNA, Version 2.0  

SciTech Connect

SCOR (http://scor.lbl.gov), the Structural Classification of RNA, is a database designed to provide a comprehensive perspective and understanding of RNA motif three-dimensional structure, function, tertiary interactions, and their relationships. SCOR 2.0 represents a major expansion and introduces a wholly new classification system. The new version represents the classification as a Directed Acyclic Graph (DAG), which allows a classification node to have multiple parents, in contrast to the strictly hierarchical classification used in SCOR 1.2. SCOR 2.0 supports three types of query terms in the updated search engine: PDB or NDB identifier, nucleotide sequence, and keyword. We also provide parseable XML files for all information. This new release contains 511RNA entries from the PDB as of 15 May 2003. A total of 5,880 secondary structural elements are classified; 2,104 hairpin loops and 3,776 internal loops. RNA motifs reported in the literature, such as ''Kinkturn'' and ''GNRA loops,'' are now incorporated into the structural classification along with definitions and descriptions.

Tamura, Makio; Hendrix, Donna K.; Klosterman, Peter

2003-10-03

431

A Summary of Validation Results for LEWICE 2.0  

NASA Technical Reports Server (NTRS)

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 point spacing, and time step criteria across general computing platforms. It also differs in the extensive amount of effort undertaken to compare the results in a quantifiable manner against the database of ice shapes which have been generated in the NASA Lewis Icing, Research Tunnel (IRT), The complete set of data used for this comparison is available in a recent contractor report . The result of this comparison shows that the difference between the predicted ice shape from LEWICE 2.0 and the average of the experimental data is 7.2% while the variability of the experimental data is 2.5%.

Wright, William B.

1998-01-01

432

Rapid Cycle Amine (RCA 2.0) System Development  

NASA Technical Reports Server (NTRS)

The Rapid Cycle Amine (RCA) system is a low-power assembly capable of simultaneously removing carbon dioxide (CO2) and humidity from an influent air steam and subsequent regeneration when exposed to a vacuum source. Two solid amine sorbent beds are alternated between an uptake mode and a regeneration mode. During the uptake mode, the sorbent is exposed to an air steam (ventilation loop) to adsorb CO2 and water (H2O) vapor, whereas during the regeneration mode, the sorbent rejects the adsorbed CO2 and H2O vapor to a vacuum source. The two beds operate such that while one bed is in the uptake mode, the other is in the regeneration mode, thus continuously providing an on-service sorbent bed by which CO2 and humidity may be removed. A novel valve assembly provides a simple means of diverting the process air flow through the uptake bed while simultaneously directing the vacuum source to the regeneration bed. Additionally, the valve assembly is designed to allow for switching between uptake and regeneration modes with only one moving part while minimizing gas volume losses to the vacuum source by means of an internal pressure equalization step during actuation. The process can be controlled by a compact, low-power controller design with several modes of operation available to the user. Together with NASA Johnson Space Center, Hamilton Sundstrand Space Systems International, Inc. has been developing RCA 2.0 based on performance and design feedback on several sorbent bed test articles and valve design concepts. A final design of RCA 2.0 was selected in November 2011 and fabricated and assembled between March and August 2012, with delivery to NASA Johnson Space Center in September 2012. This paper provides an overview of the RCA system design and results of pre-delivery testing.

Papale, William; O'Coin, James; Wichowski, Robert; Chullen, Cinda; Campbell, Colin

2013-01-01

433

Studies regarding the homogeneity range of the zirconium phosphide telluride Zr 2+?PTe 2  

NASA Astrophysics Data System (ADS)

The phosphide tellurides Zr 2+ ?PTe 2 (0 ? ? ? 1) can be synthesized from the elements in a solid state reaction or by thermal decomposition of Z. Zr 2PTe 2 decomposes under release of Te 2(g) + P 4(g) forming the homogeneity range Zr 2+ ?PTe 2. The growth of single crystals of Zr 2+?PTe 2 succeeded by chemical vapour transport using iodine as transport agent from 830 °C in direction of higher temperatures up to 900 °C. Zr 2+ ?PTe 2 crystallizes in the rhombohedral space group R3¯m (no. 166) with lattice parameters a = 383(1)…386(1) pm and c = 2935(4)…2970(4) pm for ? = 0…1, respectively. Single crystal data have been determined for Zr 2.40(2)PTe 2 with lattice parameters a = 385.24(4) pm and c = 2967.8(4) pm. The electronic structure and chemical bonding in Zr 2+ ?PTe 2 was investigated by the linear muffin-tin orbital (LMTO) method. Both Zr 2PTe 2 and Zr 3PTe 2 show non-vanishing DOS values at the Fermi level ( EF) indicating metallic character. According to COHP bonding analyses, mainly the heteroatomic Zr-P and Zr-Te bonds are responsible for the structural stability of Zr 3PTe 2. The new Zr2-Te bond, which is not present in Zr 2PTe 2, is stronger than Zr1-Te and is thought to be responsible for the stability of phases having Zr in excess.

Tschulik, Kristina; Hoffmann, Stefan; Fokwa, Boniface P. T.; Gilleßen, Michael; Schmidt, Peer

2010-12-01

434

20Ne states observed via 16O(alpha,alphai)16O  

Microsoft Academic Search

Surface barrier detectors at 16-18 angles measured simultaneously the differential cross sections for the reactions 16O(alpha,alpha0alpha1alpha2alpha3alpha4alpha5)16O in the bombarding energy range from 14.6 to 20.4 MeV and in steps of 10 keV. For Ealpha>18 MeV peak fitting techniques separated the yields of alpha1 (Q=-6.05 MeV) from alpha2 (Q=-6.13 MeV). The target was a differentially pumped windowless gas target of high

James H. Billen

1979-01-01

435

Off-shell structure of twisted (2,0) theory  

NASA Astrophysics Data System (ADS)

A Q-exact off-shell action is constructed for twisted abelian (2,0) theory on a Lorentzian six-manifold of the form M 1,5 = C × M 4, where C is a flat two-manifold and M 4 is a general Euclidean four-manifold. The properties of this formulation, which is obtained by introducing two auxiliary fields, can be summarised by a commutative diagram where the Lagrangian and its stress-tensor arise from the Q-variation of two fermionic quantities V and ? ?? . This completes and extends the analysis in [1].

Gran, Ulf; Linander, Hampus; Nilsson, Bengt E. W.

2014-11-01

436

IPG Job Manager v2.0 Design Documentation  

NASA Technical Reports Server (NTRS)

This viewgraph presentation provides a high-level design of the IPG Job Manager, and satisfies its Master Requirement Specification v2.0 Revision 1.0, 01/29/2003. The presentation includes a Software Architecture/Functional Overview with the following: Job Model; Job Manager Client/Server Architecture; Job Manager Client (Job Manager Client Class Diagram and Job Manager Client Activity Diagram); Job Manager Server (Job Manager Client Class Diagram and Job Manager Client Activity Diagram); Development Environment; Project Plan; Requirement Traceability.

Hu, Chaumin

2003-01-01

437

Environmental Satellite Resource Center (ESRC) version 2.0  

NSDL National Science Digital Library

COMET is pleased to announce the release of a significant update to the Environmental Satellite Resource Center (ESRC) to better suit our international users' needs. Aside from amassing hundreds of reliable, searchable, user-submitted resources over the last year and a half, we have developed a multi-lingual interface. Having a fully-functional Spanish interface, searching in multiple languages at once, and sorting by language of resources are just a few of the additions users can now take advantage of when using version 2.0 of the ESRC. Try the newest incarnation of the ESRC now.

2014-09-14

438

Fundamentals of Physics, Part 2 (Chapters 12-20)  

NASA Astrophysics Data System (ADS)

Chapter 12 Equilibrium and Elasticity. What injury can occur to a rock climber hanging by a crimp hold? 12-1 What Is Physics? 12-2 Equilibrium. 12-3 The Requirements of Equilibrium. 12-4 The Center of Gravity. 12-5 Some Examples of Static Equilibrium. 12-6 Indeterminate Structures. 12-7 Elasticity. Review & Summary Questions Problems. Chapter 13 Gravitation. What lies at the center of our Milky Way galaxy? 13-1 What Is Physics? 13-2 Newton's Law of Gravitation. 13-3 Gravitation and the Principle of Superposition. 13-4 Gravitation Near Earth's Surface. 13-5 Gravitation Inside Earth. 13-6 Gravitational Potential Energy. 13-7 Planets and Satellites: Kepler's Laws. 13-8 Satellites: Orbits and Energy. 13-9 Einstein and Gravitation. Review & Summary Questions Problems. Chapter 14 Fluids. What causes ground effect in race car driving? 14-1 What Is Physics? 14-2 What Is a Fluid? 14-3 Density and Pressure. 14-4 Fluids at Rest. 14-5 Measuring Pressure. 14-6 Pascal's Principle. 14-7 Archimedes' Principle. 14-8 Ideal Fluids in Motion. 14-9 The Equation of Continuity. 14-10 Bernoulli's Equation. Review & SummaryQuestionsProblems. Chapter 15 Oscillations. What is the "secret" of a skilled diver's high catapult in springboard diving? 15-1 What Is Physics? 15-2 Simple Harmonic Motion. 15-3 The Force Law for Simple Harmonic Motion. 15-4 Energy in Simple Harmonic Motion. 15-5 An Angular Simple Harmonic Oscillator. 15-6 Pendulums. 15-7 Simple Harmonic Motion and Uniform Circular Motion. 15-8 Damped Simple Harmonic Motion. 15-9 Forced Oscillations and Resonance. Review & Summary Questions Problems. Chapter 16 Waves--I. How can a submarine wreck be located by distant seismic stations? 16-1 What Is Physics? 16-2 Types of Waves. 16-3 Transverse and Longitudinal Waves. 16-4 Wavelength and Frequency. 16-5 The Speed of a Traveling Wave. 16-6 Wave Speed on a Stretched String. 16-7 Energy and Power of a Wave Traveling Along a String. 16-8 The Wave Equation. 16-9 The Principle of Superposition for Waves. 16-10 Interference of Waves. 16-11 Phasors. 16-12 Standing Waves. 16-13 Standing Waves and Resonance. Review & Summary Questions Problems. Chapter 17 Waves--II. How can an emperor penguin .nd its mate among thousands of huddled penguins? 17-1 What Is Physics? 17-2 Sound Waves. 17-3 The Speed of Sound. 17-4 Traveling Sound Waves. 17-5 Interference. 17-6 Intensity and Sound Level. 17-7 Sources of Musical Sound. 17-8 Beats. 17-9 The Doppler Effect. 17-10 Supersonic Speeds, Shock Waves. Review & Summary Questions Problems. Chapter 18 Temperature, Heat, and the First Law of Thermodynamics. How can a dead rattlesnake detect and strike a reaching hand? 18-1 What Is Physics?. 18-2 Temperature. 18-3 The Zeroth Law of Thermodynamics. 18-4 Measuring Temperature. 18-5 The Celsius and Fahrenheit Scales. 18-6 Thermal Expansion. 18-7 Temperature and Heat. 18-8 The Absorption of Heat by Solids and Liquids. 18-9 A Closer Look at Heat and Work. 18-10 The First Law of Thermodynamics. 18-11 Some Special Cases of the First Law of Thermodynamics. 18-12 Heat Transfer Mechanisms. Review & Summary Questions Problems. Chapter 19 The Kinetic Theory of Gases. How can cooling steam inside a railroad tank car cause the car to be crushed? 19-1 What Is Physics? 19-2 Avogadro's Number. 19-3 Ideal Gases. 19-4 Pressure, Temperature, and RMS Speed. 19-5 Translational Kinetic Energy. 19-6 Mean Free Path. 19-7 The Distribution of Molecular Speeds. 19-8 The Molar Speci.c Heats of an Ideal Gas. 19-9 Degrees of Freedom and Molar Speci.c Heats. 19-10 A Hint of Quantum Theory. 19-11 The Adiabatic Expansion of an Ideal Gas. Review & Summary Questions Problems. Chapter 20 Entropy and the Second Law of Thermodynamics. Why is the popping of popcorn irreversible? 20-1 What Is Physics? 20-2 Irreversible Processes and Entropy. 20-3 Change in Entropy. 20-4 The Second Law of Thermodynamics. 20-5 Entropy in the Real World: Engines. 20-6 Entropy in the Real World: Refrigerators. 20-7 The Ef.ciencies of Real Engines. 20-8 A Statistical View of Entropy. Review &#

Halliday, David; Resnick, Robert; Walker, Jearl

2003-12-01

439

Structural option design in JZ20-2 offshore project  

SciTech Connect

In the JZ20-2 Project, ice and earthquakes are the main loads which determine the member sizes of offshore structures. UQ and W platforms are located at same field. The vertical loads of an UQ platform are about two times as much as a W platform, but structural steel weight used by two platforms is about the same. This paper describes the results to be acquired and how to determine reasonably the standard of ice load and the resistance to earthquakes with less stiffness and large mass. This paper presents some useful principles and enlightenment for offshore engineering.

Wang Lianqi [COODEC, Beijing (China)

1993-12-31

440

AFCI-2.0 Neutron Cross Section Covariance Library  

SciTech Connect

The cross section covariance library has been under development by BNL-LANL collaborative effort over the last three years. The project builds on two covariance libraries developed earlier, with considerable input from BNL and LANL. In 2006, international effort under WPEC Subgroup 26 produced BOLNA covariance library by putting together data, often preliminary, from various sources for most important materials for nuclear reactor technology. This was followed in 2007 by collaborative effort of four US national laboratories to produce covariances, often of modest quality - hence the name low-fidelity, for virtually complete set of materials included in ENDF/B-VII.0. The present project is focusing on covariances of 4-5 major reaction channels for 110 materials of importance for power reactors. The work started under Global Nuclear Energy Partnership (GNEP) in 2008, which changed to Advanced Fuel Cycle Initiative (AFCI) in 2009. With the 2011 release the name has changed to the Covariance Multigroup Matrix for Advanced Reactor Applications (COMMARA) version 2.0. The primary purpose of the library is to provide covariances for AFCI data adjustment project, which is focusing on the needs of fast advanced burner reactors. Responsibility of BNL was defined as developing covariances for structural materials and fission products, management of the library and coordination of the work; LANL responsibility was defined as covariances for light nuclei and actinides. The COMMARA-2.0 covariance library has been developed by BNL-LANL collaboration for Advanced Fuel Cycle Initiative applications over the period of three years, 2008-2010. It contains covariances for 110 materials relevant to fast reactor R&D. The library is to be used together with the ENDF/B-VII.0 central values of the latest official release of US files of evaluated neutron cross sections. COMMARA-2.0 library contains neutron cross section covariances for 12 light nuclei (coolants and moderators), 78 structural materials and fission products, and 20 actinides. Covariances are given in 33-energy groups, from 10?5 eV to 19.6 MeV, obtained by processing with LANL processing code NJOY using 1/E flux. In addition to these 110 files, the library contains 20 files with nu-bar covariances, 3 files with covariances of prompt fission neutron spectra (238,239,240-Pu), and 2 files with mu-bar covariances (23-Na, 56-Fe). Over the period of three years several working versions of the library have been released and tested by ANL and INL reactor analysts. Useful feedback has been collected allowing gradual improvements of the library. In addition, QA system was developed to check basic properties and features of the whole library, allowing visual inspection of uncertainty and correlations plots, inspection of uncertainties of integral quantities with independent databases, and dispersion of cross sections between major evaluated libraries. The COMMARA-2.0 beta version of the library was released to ANL and INL reactor analysts in October 2010. The final version, described in the present report, was released in March 2011.

Herman, M.; Herman, M; Oblozinsky, P.; Mattoon, C.M.; Pigni, M.; Hoblit, S.; Mughabghab, S.F.; Sonzogni, A.; Talou, P.; Chadwick, M.B.; Hale, G.M.; Kahler, A.C.; Kawano, T.; Little, R.C.; Yount, P.G.

2011-03-01

441

Complex permittivity of lanthanum aluminate in the 20 to 300 K temperature range from 26.5 to 40.0 GHz  

NASA Technical Reports Server (NTRS)

Dielectric constants of microwave substrates are required in the design of superconducting microwave circuits at various temperatures. In this paper, the results are reported of a study of the complex permittivity of the newly developed lanthanum aluminate (LaAlO3) substrate, in the 20 to 300 K temperature range at frequencies from 26.5 to 40.0 GHz. The value of the complex permittivity was obtained by measuring the sample scattering parameters using a microwave waveguide technique. It is observed that, while the dielectric constant did not change appreciably with frequency, its value decreased by approximately 14 percent from room temperature to 20 K.

Miranda, F. A.; Gordon, W. L.; Bhasin, K. B.; Ebihara, B. T.; Heinen, V. O.; Chorey, C. M.

1990-01-01

442

Investigation of radiation patterns in the 8-12 micron range as observed by Tiros III over the Caribbean Sea during the period 20-21 July 1961  

E-print Network

INVESTIGATION OF RADIATION PATTERNS IN THE 8-12 MICRON RANGE AS OBSERVED BY TIROS III OVER THE CARIBBEAN SEA DURING THE PERIOD 20-21 JULY 1961 A Thesis By PAUL IRVIN MOHLER Captain, United States Air Force Submitted to the Graduate School... THE CARIBBEAN SEA DURING THE PERIOD 20-21 JULY 1961 A Thesis By PAUL IRVIN MOHLER Captain, United States Air Force Approved as to style and content by: rman o Comm tt ea o Department August 1963 ACKNOWLEDGEMENTS The writer 's graduate program was made...

Mohler, Paul Irvin

1963-01-01

443

0 2 4 6 8 10 12 14 16 18 20 0 5 10 15 20 25 30  

E-print Network

. The majority of the calls are fin whales, but blue whales were ob- served on at least 9 days (red). In addition 5000 6000 7000 8000 9000 10000 Hour of Day Figure 4. (left) Example of a blue whale vocalization,s Range, km Figure 5. (above) Examples of ray paths between a whale and a seafloor seismometer at 20 km

Wilcock, William

444

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

NASA Astrophysics Data System (ADS)

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 H? 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 H? 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/H?) 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.

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

2009-02-01

445

Accretion Properties of A Sample of Hard X-ray (<60keV) Selected Seyfert 1 Galaxies  

E-print Network

We examine the accretion properties in a sample of 42 hard (3-60keV) X-ray selected nearby broad-line AGNs. The energy range in the sample is harder than that usually used in the similar previous studies. These AGNs are mainly complied from the RXTE All Sky Survey (XSS), 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 H$\\beta$ emission line. The tight correlation between the hard X-ray (3-20keV) and bolometric/line luminosity is well identified in our sample. Also identified is a strong inverse Baldwin relationship of the H$\\beta$ emission line. In addition, all these hard X-ray AGNs are biased toward luminous objects with high Eddington ratio (mostly between 0.01 to 0.1) and low column density ($<10^{22} \\mathrm{cm^{-2}}$), 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 INTEGRAL missions, and by the next advanced missions, such as NuSTAR, Simbol-X, and NeXT. Finally, the correlation between RFe (=optical FeII/H$\\beta$) and disk temperature as assessed by $T\\propto (L/L_{\\mathrm{Edd}})M_{\\mathrm{BH}}^{-1}$ leads us to suggest that the strength of the FeII emission is mainly determined by the shape of the ionizing spectrum.

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

2008-11-20

446

Projet Long 2009-2010 Titre: Evoluption, le transport 2.0  

E-print Network

Projet Long 2009-2010 Titre: Evoluption, le transport 2.0 Mots clés: transport, co-voiturage, web2 déplacements. L'internet 2.0 (ou web 2.0) décrit une 2e génération de sites web, dont les standards projets pour plus d'information Evoluption, transport2.0 Web 2.0 Réseaux sociaux Environnement

Grigoras, .Romulus

447

The Einstein Observatory catalog of IPC x ray sources. Volume 7E: Right ascension range 20h 00m to 23h 59m  

NASA Technical Reports Server (NTRS)

The Einstein Observatory (HEAO-2, launched November 13, 1978) achieved radically improved sensitivity over previous x-ray missions through the use of focusing optics which simultaneously afforded greatly reduced background and produced true images. During its 2.5-yr mission, the Einstein X-Ray Telescope was pointed toward some 5,000 celestial targets, most of which were detected, and discovered several thousand additional 'serendipitous' sources in the observed fields. This catalog contains contour diagrams and source data, obtained with the imaging proportional counter in the 0.16 to 3.5 keV energy band, and describes methods for recovering upper limits for any sky position within the observed images. The main catalog consists of six volumes (numbered 2 through 7) of right ascension ordered pages, each containing data for one observation. Along with the primary documentation describing how the catalog was constructed, volume 1 contains a complete source list, results for merged fields, a reference system to published papers, and data useful for calculating upper limits and fluxes.

Harris, D. E.; Forman, W.; Gioia, I. M.; Hale, J. A.; Harnden, F. R., Jr.; Jones, C.; Karakashian, T.; Maccacaro, T.; Mcsweeney, J. D.; Primini, F. A.

1993-01-01

448

A search for water masers associated with class II methanol masers - I. Longitude range 6 to 20 degrees  

E-print Network

The Australia Telescope Compact Array has been used to search for 22-GHz water masers towards the 119 6.7-GHz methanol masers detected in the Methanol Multi-Beam survey between Galactic longitudes 6 and 20 degrees; we find water masers associated with 55 (~46 per cent). Methanol masers with associated water masers have a higher mean integrated luminosity than those without and there is a general trend for sources with more luminous 6.7-GHz methanol masers to be associated with more luminous water maser emission. We have inspected the GLIMPSE three colour images of the regions surrounding the masers and cross-matched the maser positions with existing catalogues of Extended Green Objects and Infrared Dark Clouds. We find more Extended Green Objects at sites where both methanol and water masers are present than at sites with only methanol masers, but no significant difference in the fraction embedded within Infrared Dark Clouds. Analysis of the 1.1-mm dust emission shows dust clumps associated with masers that h...

Titmarsh, A M; Breen, S L; Caswell, J L; Voronkov, M A

2014-01-01

449

Investigation of magnetic order in SmTr2Zn20 (Tr=Fe ,Co,Ru) and SmTr2Cd20 (Tr=Ni ,Pd)  

NASA Astrophysics Data System (ADS)

Single crystals of the "cage compounds" SmTr2Zn20 (Tr=Fe, Co, Ru) and SmTr2Cd20 (Tr=Ni, Pd) have been investigated by means of electrical resistivity, magnetization, and specific-heat measurements. The compounds SmFe2Zn20,SmRu2Zn20, and SmNi2Cd20 exhibit ferromagnetic order with Curie temperatures of TC=47.4, 7.6, and 7.5 K, respectively, whereas SmPd2Cd20 is an antiferromagnet with a Néel temperature of TN=3.4 K. No evidence for magnetic order is observed in SmCo2Zn20 down to 110 mK. The Sommerfeld coefficients ? are found to be 57 mJ /molK2 for SmFe2Zn20,79.5 mJ /molK2 for SmCo2Zn20,258 mJ /molK2 for SmRu2Zn20,165 mJ /molK2 for SmNi2Cd20, and 208 mJ /molK2 for SmPd2Cd20. Enhanced values of ? and a quadratic temperature dependence of the electrical resistivity at low temperature for SmRu2Zn20 and SmPd2Cd20 suggest an enhancement of the quasiparticle masses due to hybridization between localized 4f and conduction electron states.

Yazici, D.; White, B. D.; Ho, P.-C.; Kanchanavatee, N.; Huang, K.; Friedman, A. J.; Wong, A. S.; Burnett, V. W.; Dilley, N. R.; Maple, M. B.

2014-10-01

450

Study of the conversion electron spectrum of the 2. 1726-keV transition in /sup 99m/Tc located in a matrix of metallic technetium  

SciTech Connect

The spectrum of conversion electrons of the E3 transition is studied in /sup 99m/Tc located in a matrix of metallic technetium. On the basis of comparison of the conversion spectrum measured with high resolution and the x-ray photoelectron and Auger spectra of metallic technetium we have identified the conversion peaks in the N/sub 2,3/ and valence N/sub 4,5/ and O/sub 1/ electrons and have obtained an improved value of the E3 transition energy: 2172.6 +- 0.4 eV. We have determined the relative intensities of the conversion lines M/sub 2//M/sub 3//M/sub 4,5//N/sub 2,3//N/sub 4,5/, O/sub 1/ = 57.0 +- 1.8/100/47.2 +- 1.0/26.1 +- 2.3/4.4 +- 0.5. For a conversion electron source containing /sup 99m/Tc in two chemical states (metallic and technetium dioxide) we have observed chemical shifts of the conversion lines. The results are discussed.

Gerasimov, V.N.; Zelenkov, A.G.; Kulakov, V.M.; Pchelin, V.A.; Soldatov, A.A.; Stepanchikov, V.A.; Chistyakov, L.V.

1981-07-01

451

A search for water masers associated with class II methanol masers - I. Longitude range 6°-20°  

NASA Astrophysics Data System (ADS)

The Australia Telescope Compact Array has been used to search for 22-GHz water masers towards the 119 6.7-GHz methanol masers detected in the Methanol MultiBeam survey between Galactic longitudes 6° and 20°; we find water masers associated with 55 (˜46 per cent). Methanol masers with associated water masers have a higher mean integrated luminosity than those without and there is a general trend for sources with more luminous 6.7-GHz methanol masers to be associated with more luminous water maser emission. We have inspected the GLIMPSE (Galactic Legacy Infrared Mid-plane Survey Extraordinaire) three colour images of the regions surrounding the masers and cross-matched the maser positions with existing catalogues of Extended Green Objects and infrared dark clouds. We find more Extended Green Objects at sites where both methanol and water masers are present than at sites with only methanol masers, but no significant difference in the fraction embedded within infrared dark clouds. Analysis of the 1.1-mm dust emission shows dust clumps associated with masers that have greater flux densities and higher column densities than those without. Dust clumps associated with both water and 6.7-GHz methanol masers are generally the most compact clumps followed by those associated with only methanol then the clumps without associated maser emission. We conclude that protostars with both methanol and water masers are often older than those with only methanol; however, we suggest that the evolutionary phase traced by water masers is not as well defined as for 6.7-GHz methanol masers.

Titmarsh, A. M.; Ellingsen, S. P.; Breen, S. L.; Caswell, J. L.; Voronkov, M. A.

2014-10-01

452

Toward precise QEC values for the superallowed 0+?0+ ? decays of T=2 nuclides: The masses of Na20, Al24, P28, and Cl32  

NASA Astrophysics Data System (ADS)

High-precision measurements of superallowed 0+?0+ ? decays of T=2 nuclides such as Mg20, Si24, S28, and Ar32 can contribute to searches for physics beyond the standard model of particle physics if the QEC values are accurate to a few keV or better. As a step toward providing precise QEC values for these decays, the ground-state masses of the respective daughter nuclei Na20, Al24, P28, and Cl32 have been determined by measuring the (He3,t) reactions leading to them with the Ar36(He3,t)K36 reaction as a calibration. A quadrupole-dipole-dipole-dipole (Q3D) magnetic spectrograph was used together with thin ion-implanted carbon-foil targets of Ne20, Mg24, Si28, S32, and Ar36. The masses of Na20 and Cl32 are found to be in good agreement with the values from the 2003 Atomic Mass Evaluation (AME03) [G. Audi, A. H. Wapstra, and C. Thibault, Nucl. Phys. ANUPABL0375-947410.1016/j.nuclphysa.2003.11.003 729, 337 (2003)], and the precision has been improved by a factor of 6 in both cases. The masses of Al24 and P28 are found to be higher than the values from AME03 by 9.5 keV (3.2?) and 11.5 keV (3.6?), respectively, and the precision has been improved by a factor of 2.5 in both cases. The new Cl32 mass is used together with the excitation energy of its lowest T=2 level and the mass of Ar32 to derive an improved superallowed QEC value of 6087.3(22) keV for this case. The effects on quantities related to standard-model tests including the ?-? correlation coefficient a and the isospin-symmetry-breaking correction ?C are examined for the A=32 case.

Wrede, C.; Clark, J. A.; Deibel, C. M.; Faestermann, T.; Hertenberger, R.; Parikh, A.; Wirth, H.-F.; Bishop, S.; Chen, A. A.; Eppinger, K.; García, A.; Krücken, R.; Lepyoshkina, O.; Rugel, G.; Setoodehnia, K.

2010-05-01

453

Quiet-time convection electric field properties derived from keV electron measurements at the inner edge of the plasma sheet by means of GEOS2  

Microsoft Academic Search

Results are given of an analysis of the electron upper energy limit local time distribution reached by the GEOS-2 satellite, in cutting through the innermost element of the electron plasma sheet during quiet conditions. It is found that an electric field model whose dusk singular point of the forbidden region lies at 1500 rather than 1800 M.L.T. is in agreement

B. Hultqvist; H. Borg; L.-A. Holmgren; H. Reme; A. Bahnsen; M. Jespersen; G. Kremser

1982-01-01

454

ENA (E>5 keV) Images from Cassini and Voyager ``ground truth'': Suprathermal Pressure in the Heliosheath  

NASA Astrophysics Data System (ADS)

Maps of energetic neutral atoms (ENA) of the heliosphere from Cassini [1] have been constructed spanning the energy range ~5<=E<=55 keV, and show a ``Belt'' in the sky of ~100° FWHM. Similarly, maps >6 keV have been obtained by the IBEX mission [2] and show a ``Ribbon'' that is narrower than the Belt and inclined to it in both ecliptic latitude (~25°) and longitude (~30°). The overlap in energy between Voyager ions [3] and Cassini ENA intensities (averaged over the ENA line of sight) enables us to deduce ion fluxes in the heliosheath, thus providing a continuous spectrum 5<=E<=4000 keV. These measurements are then used to estimate the local partial pressure over this energy range (~0.1 pPa), suggesting ?>25 [4] and the thickness of the heliosheath (~50 AU). Using a simulated PUI distribution [5], we estimate the E<6 keV contribution to be ~0.12 pPa. The balance of the non-thermal pickup ion (PUI) pressure against the stagnation pressure of the interstellar plasma and the local interstellar magnetic field (ISMF) at the nose of the heliopause implies an upper bound on the ISMF of ~0.64 nT.

Krimigis, S. M.; Mitchell, D. G.; Roelof, E. C.; Decker, R. B.

2010-12-01

455

Experimental equipment for the evaluation of the strength characteristics of carbon-carbon composite mateials within the temperature range 20–2200°C  

Microsoft Academic Search

We suggest procedures for testing and describe the design of a UKM-2200 specialized experimental installation for tensile\\u000a and bending testing of specimens made of carbon-carbon composite materials in a vaccum or inert media within the temperature\\u000a range 20–2200C. We discuss the results of strength tests for specimens of carbon-carbon composite materials with multidirected\\u000a spatial reinforcement of the structure and with

A. N. Negovskii; A. V. Drozdov; V. V. Kutnyak; Yu. A. Nozhnitskii; A. N. Menshikov; Qiao Shengru; Bai Shihong

1999-01-01

456

Compact, maintainable 80-KeV neutral beam module  

DOEpatents

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.

Fink, Joel H. (Livermore, CA); Molvik, Arthur W. (Livermore, CA)

1980-01-01

457

IBEX Heliospheric neutral atom energy spectra between 0.01 and 6 keV  

NASA Astrophysics Data System (ADS)

Since early 2009, 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 ~0.5 keV. For the globally distributed population, many neutrals in this energy range are produced by pick up (ionization) of interstellar neutrals in the heliosphere, convection across the termination shock, and a second charge exchange in the heliosheath. With more than 2 years of observations, enough low energy neutral atom measurements have been accumulated to extend IBEX observations down to energies below ~0.5 keV. At these energies, contributions from two additional populations of low energy neutral atoms from the heliosheath become significant. The first population is produced by charge exchange of interstellar neutrals in the heliosheath, beyond the termination shock, and a second charge exchange in the same region. The second population is produced by charge exchange between much slower solar wind ions in the heliosheath and interstellar neutrals. Using the energy overlap of the sensors and observations in different regions near the Earth to identify and remove backgrounds, energy spectra over the entire energy range of IBEX are produced. Compared to spectra at higher energies, neutral atom spectra at lower energies do not vary greatly from location to location in the sky, including in the direction of the IBEX ribbon. Implications for these observations on global heliospheric structure and interactions are discussed.

Fuselier, S. A.; Allegrini, F.; Funsten, H. O.; Ghielmetti, A. G.; Gloeckler, G.; Heirtzler, D.; Janzen, P. H.; Kucharek, H.; McComas, D. J.; Moebius, E.; Moore, T. E.; Petrinec, S. M.; Quinn, M.; Reisenfeld, D. B.; Saul, L. A.; Scheer, J.; Schwadron, N. A.; Trattner, K. J.; Vanderspek, R.; Wurz, P.

2011-12-01

458

Web 2.0 and Marketing Education: Explanations and Experiential Applications  

ERIC Educational Resources Information Center

Although both experiential learning and Web 2.0 tools focus on creativity, sharing, and collaboration, sparse research has been published integrating a Web 2.0 paradigm with experiential learning in marketing. In this article, Web 2.0 concepts are explained. Web 2.0 is then positioned as a philosophy that can advance experiential learning through…

Granitz, Neil; Koernig, Stephen K.

2011-01-01

459

Stakeholder-Orientierung als Gestaltungsprinzip fr Corporate Web 2.0: Eine explorative Analyse  

E-print Network

Stakeholder-Orientierung als Gestaltungsprinzip für Corporate Web 2.0: Eine explorative Analyse Potentiale von Corporate Web 2.0 besser zu realisieren. Bisherige Ansätze im Corporate Web 2.0 rückten kaum leisten einen Beitrag zum besseren Verständnis von Corporate Web 2.0 und zeigen in einer explorativen

460

Dual nature of electron spin resonance in YbCo2Zn20 intermetallic compound  

NASA Astrophysics Data System (ADS)

In single crystals of YbCo2Zn20 intermetallic compound, two coexisting types of electron spin resonance signals related to the localized magnetic moments of cobalt and to itinerant electrons have been observed in the 4.2-300 K temperature range. It is shown that the relative contribution of itinerant electrons to the total magnetization does not exceed 9%. We argue that the electron dynamics in YbCo2Zn20 and YbCuAl heavy fermion systems is determined by the effects produced by the magnetic subsystem of the localized 3 d-electrons. We also discuss general aspects of the electron spin resonance spectroscopy in underdoped ytterbium-based intermetallics and the spectral manifestations of the interplay between the efficiency of the hybridization of f-electrons with the electrons filling outer atomic shells, crystal field effects, and the effects related to the proximity to the quantum critical point.

Ivanshin, V. A.; Litvinova, T. O.; Sukhanov, A. A.; Ivanshin, N. A.; Jia, S.; Bud'ko, S. L.; Canfield, P. C.

2014-04-01