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1

Sputtering yields, range and range straggling in Al following Kr + ions bombardment in the energy range (20-160) keV  

NASA Astrophysics Data System (ADS)

The sputtering of Al metallic films by 84Kr + ions has been studied over the energy range (20-160) keV. Sputtering yield data have been extracted by means of the Rutherford backscattering technique (RBS) using a 2 MeV beam of 4He + ions. They have been compared to values derived by Sigmund's linear cascade theory, Yamamura's semi-empirical formula or by Monte Carlo computer simulation using the TRIM code. A fair agreement was observed between the measured sputtering yields and the predicted ones. The depth profiles of the implanted Kr + ions into Al have also been measured, and then fitted assuming Gaussian shape distributions, which allowed us to extract the projected range, Rp, and the associated range straggling, ? Rp. For the former stopping parameter, a very good agreement is obtained between experiment and the LSS theory predictions while the MC simulation also accounts satisfactorily for the measured data over the whole explored energy range, reflecting an adequate description of the projectile-target interaction by the universal potential of the Thomas-Fermi type assumed in the LSS formalism. In contrast, the ? Rp measured data show to be consistent with the predicted values only at E ? 60 keV but lie to ˜30% above them at lower energies. This discrepancy not caused by the sputtering effect relates to an incomplete evaluation of the range straggling by theory at low bombarding energies.

Mammeri, S.; Ouichaoui, S.; Zemih, R.; Ammi, H.; Abdesselam, M.; Chami, A. C.

2005-10-01

2

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

NASA Technical Reports Server (NTRS)

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

Bleach, R. D.

1972-01-01

3

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

NASA Technical Reports Server (NTRS)

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

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

1983-01-01

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

Range measurement of boron isotopes in silicon from 600 keV to 2 MeV  

NASA Astrophysics Data System (ADS)

Ranges of boron isotopes with masses 10 and 11 were measured in silicon for implantation energies of 600 keV, 1.0, 1.5 and 2.0 MeV by use of high-energy elastic recoil detection analysis (HE-ERDA). The measured ranges were compared with TRIM and PRAL calculations. The experimental data show a deviation to larger depth particularly at higher energies. The ratio of the ranges of the isotopes is always lower than theoretically predicted. The experimental results can be interpreted as follows: the electronic stopping, which dominates this energy regime, increases slower than expected. The maximum of the stopping power is shifted towards lower energies and is lower than calculated. In the lower energy range the stopping power must be larger than predicted leading to smaller ranges for energies up to 1 MeV. Our experiment is in good agreement with former range measurements of Behar et al. [Nucl. Instr. and Meth. B34 (1988) 316] who used the very reliable 10B(n, ?) 6Li nuclear reaction technique (neutron depth profiling: NDP), and of Svensson et al. [J. Appl. Phys. 68 (1990) 73] using secondary ion mass spectroscopy (SIMS), who both found this behavior, too.

Goppelt, P.; Biersack, J. P.; Gebauer, B.; Fink, D.; Bohne, W.; Wilpert, M.; Wilpert, Th.

1993-06-01

6

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

NASA Astrophysics Data System (ADS)

We report on Cyg X-1 observations performed by the SPI telescope on board 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-ray 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 polarized flux, while compatible with the MeV emission detected some years ago by the Compton Gamma-ray Observatory/COMPTEL. Finally, we take advantage of the spectroscopic capability of the instrument to seek for spectral features in the 500 keV region with negative results for any significant annihilation emission on 2 ks and day timescales, as well as in the total data set. Based on observations with INTEGRAL, an ESA project with instruments and science data centre funded by ESA member states (especially the PI countries: Denmark, France, Germany, Italy, Spain, and Switzerland), Czech Republic and Poland with participation of Russia and USA.

Jourdain, E.; Roques, J. P.; Malzac, J.

2012-01-01

7

Extremely Small Proximity Effect in 30keV Electron Beam Drawing with Thin Calixarene Resist for 20× 20nm2 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 ?m 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

8

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

9

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

NASA Astrophysics Data System (ADS)

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. 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 1s2-1s2p 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.

2008-10-01

10

FISM 2.0: Improved Spectral Range, Resolution, and Accuracy  

NASA Technical Reports Server (NTRS)

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

Chamberlin, Phillip C.

2012-01-01

11

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

SciTech Connect

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

Imazono, Takashi; Koike, Masato; Kawachi, Tetsuya; Hasegawa, Noboru; Koeda, Masaru; Nagano, Tetsuya; Sasai, Hiroyuki; Oue, Yuki; Yonezawa, Zeno; Kuramoto, Satoshi; Terauchi, Masami; Takahashi, Hideyuki; Handa, Nobuo; Murano, Takanori [Quantum Beam Science Directorate, Japan Atomic Energy Agency, 8-1-7 Umemidai, Kizugawa, Kyoto 619-0215 (Japan); Device Dept., Shimadzu Corp., 1 Nishinokyo-Kuwabara-cho, Nakagyo-ku, Kyoto 604-8511 (Japan); IMRAM, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); ECBU, JEOL Ltd., 3-1-2 Musashino, Akishima, Tokyo 196-8558 (Japan)

2012-07-11

12

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

NASA Astrophysics Data System (ADS)

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

Lin, Jiunn-Yuan

13

Charge-transfer processes in collisions of H+ ions with H2, D2, CO, and CO2 molecules in the energy range 0.2-4.0 keV  

NASA Astrophysics Data System (ADS)

Charge-transfer processes resulting from collisions of H+ ions with H2, D2, CO, and CO2 molecules have been experimentally investigated in the energy range of 0.2-4.0 keV by using the initial growth-rate method. Theoretical analysis based on a molecular-orbital expansion method for H2 and CO targets was also carried out. The observed cross sections are compared with previous experimental and theoretical data. The present results for H2 are found to be in excellent accord with the recommended data by Barnett [Oak Ridge National Laboratory Report No. ORNL-6086 (1990)], and hence, confirm the accuracy of the recommended data. But, at 0.2 keV, the present data for D2 are found to be smaller than those for H2. For the CO molecule, the present data qualitatively agree well with most previous measurements, but show the stronger energy dependence, while the present theory shows a pronounced structure at around 0.25 keV and ties well with other low-energy measurements below 0.1 keV. For the CO2 molecule, the present results are in excellent accord with other measurements above 1 keV, while they show some differences below this energy where our experimental result displays the stronger energy dependence. These data are useful for various applications.

Kusakabe, Toshio; Asahina, Kensuke; Gu, Jiang P.; Hirsch, Gerhard; Buenker, Robert J.; Kimura, Mineo; Tawara, Hiroyuki; Nakai, Yohta

2000-12-01

14

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

SciTech Connect

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

Mirzoeva, I. K., E-mail: colombo2006@mail.ru [Russian Academy of Sciences, Space Research Institute (Russian Federation)

2013-04-15

15

Systematic Errors in Primary Acoustic Thermometry in the Range 2-20 K  

Microsoft Academic Search

Following a brief review of the fundamental principles of acoustic thermometry in the range 2-20 K, its systematic errors are analysed in depth. It is argued that the ultrasonic technique suffers from certain sources of error which are virtually impossible to assess quantitatively except on the basis of certain conjectures about the excitation of the thermometer's resonant cavity. These are

A. R. Colclough

1973-01-01

16

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

NASA Technical Reports Server (NTRS)

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

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

2006-01-01

17

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

SciTech Connect

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

Vine, D. J. [Australian Research Council Centre of Excellence for Coherent X-ray Science (Australia); School of Physics, University of Melbourne, Victoria 3010 (Australia); Argonne National Laboratory, Argonne, Illinois 60439 (United States); Williams, G. J. [Australian Research Council Centre of Excellence for Coherent X-ray Science (Australia); SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Clark, J. N. [Australian Research Council Centre of Excellence for Coherent X-ray Science (Australia); Department of Physics, La Trobe University, Bundoora, Victoria 3086 (Australia); London Centre for Nanotechnology, University College, London WC1E 6BT (United Kingdom); Putkunz, C. T.; Abbey, B.; Nugent, K. A. [Australian Research Council Centre of Excellence for Coherent X-ray Science (Australia); School of Physics, University of Melbourne, Victoria 3010 (Australia); Pfeifer, M. A. [Australian Research Council Centre of Excellence for Coherent X-ray Science (Australia); Cornell High Energy Synchrotron Source, Cornell University, Ithaca, New York 14850 (United States); Legnini, D.; Roehrig, C.; Wrobel, E.; McNulty, I. [Argonne National Laboratory, Argonne, Illinois 60439 (United States); Huwald, E. [Department of Physics, La Trobe University, Bundoora, Victoria 3086 (Australia); Riessen, G. van; Peele, A. G. [Australian Research Council Centre of Excellence for Coherent X-ray Science (Australia); Department of Physics, La Trobe University, Bundoora, Victoria 3086 (Australia); Beetz, T.; Irwin, J.; Feser, M.; Hornberger, B. [Xradia, Inc., 4385 Hopyard Road, Pleasanton, California 94588 (United States)

2012-03-15

18

The pulse profile of the Crab pulsar in the energy range 45 keV-1.2 MeV  

NASA Technical Reports Server (NTRS)

The Crab Nebula pulsar (PSR 0531+21) is the best studied and most intense of the nontransient X-ray pulsars. However, since its spectrum drops rapidly with energy, a well-resolved pulse profile has not previously been obtained above 200 keV. In the hard X-ray and low-energy gamma-ray region, an accurate pulse profile can be obtained with a balloon-borne detector of sufficient area during a single transit of the source. A new measurement of the pulse profile of PSR 0531+21 in the energy range above 45 keV obtained with a large-area scintillation detector array is reported. The detector array was flown on a balloon launched from Palestine, Texas on 1980 October 6, reaching a float altitude 4.5 g/sq cm at 0230 UTC October 7. The primary objective of the experiment was to detect and study weak gamma-ray bursts.

Wilson, R. B.; Fishman, G. J.

1983-01-01

19

Energy dependence of effective atomic numbers for photon energy absorption and photon interaction: studies of some biological molecules in the energy range 1 keV-20 MeV.  

PubMed

Effective atomic numbers for photon energy absorption, Z(PEA,eff), and for photon interaction, Z(PI,eff), have been calculated by a direct method in the photon-energy region from 1 keV to 20 MeV for biological molecules, such as fatty acids (lauric, myristic, palmitic, stearic, oleic, linoleic, linolenic, arachidonic, and arachidic acids), nucleotide bases (adenine, guanine, cytosine, uracil, and thymine), and carbohydrates (glucose, sucrose, raffinose, and starch). The Z(PEA,eff) and Z(PI,eff) values have been found to change with energy and composition of the biological molecules. The energy dependence of the mass attenuation coefficient, Z(PEA,eff), and the mass energy-absorption coefficient, Z(PI,eff), is shown graphically and in tabular form. Significant differences of 17%-38% between Z(PI,eff) and Z(PEA,eff) occur in the energy region 5-100 keV. The reasons for these differences, and for using Z(PEA,eff) rather than Z(PI,eff) in calculations of the absorbed dose, are discussed. PMID:18293593

Manohara, S R; Hanagodimath, S M; Gerward, L

2008-01-01

20

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

21

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

SciTech Connect

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

Babenko, V. A., E-mail: vladimir@ukr.net; Petrov, N. M., E-mail: pet2@ukr.ne [National Academy of Sciences of Ukraine, Bogolyubov Institute for Theoretical Physics (Ukraine)

2009-04-15

22

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.

23

A 20 keV electron gun system for the electron irradiation experiments  

Microsoft Academic Search

An electron gun consisting of cathode, focusing electrode, control electrode and anode has been designed and fabricated for the electron irradiation experiments. This electron gun can provide electrons of any energy over the range 1–20keV, with current upto 50?A. This electron gun and a Faraday cup are mounted in the cylindrical chamber. The samples are fixed on the Faraday cup

S. K. Mahapatra; S. D. Dhole; V. N. Bhoraskar

2005-01-01

24

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

NASA Technical Reports Server (NTRS)

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

Garmire, G. P.

1974-01-01

25

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

26

Charge-transfer processes in collisions of ground-state C+ ions with H2, D2, CO, and CO2 molecules in the energy range from 0.15 to 4.5 keV  

NASA Astrophysics Data System (ADS)

Charge-transfer processes in collisions of C+ ions with H2, D2, CO, and CO2 molecules have been studied based on joint experimental and theoretical approaches in the collision energy from 0.15 to 4.5 keV. In the present experiment, the ground-state C+(2P) ion projectiles have been produced by carefully energy-controlled electron impact to minimize the influence of the metastable-state ions. The observed cross sections are compared with the present theoretical prediction, and while the theoretical results are somewhat smaller than the measurements, they are found to be in reasonable agreement for H2, D2, and CO above around 1 keV. The present experimental cross sections for CO and CO2 are smaller by a factor of 2 to 3 than those of earlier measurements. We provide some remarks on the effect of the metastable-state ions.

Kusakabe, Toshio; Hosomi, Kenji; Nakanishi, Hiroshi; Tawara, Hiroyuki; Sasao, Mamiko; Nakai, Yohta; Kimura, Mineo

1999-07-01

27

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

NASA Astrophysics Data System (ADS)

A nano-sized ion beam apparatus has been used as maskless lithography to implant 20 keV Ga+ 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 × 1014/cm2. 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 °C temperature range and the interfaces with the surrounding crystalline regions sharpen. A temperature as high as 600 °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 °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.; Milazzo, R. G.; Rimini, E.; Spinella, C.; Peto, L.; Nadzeyka, A.; Bauerdick, S.

2013-01-01

28

Rise time in 20-32 keV impulsive X-radiation  

NASA Technical Reports Server (NTRS)

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

Vorpahl, J. A.; Takakura, T.

1974-01-01

29

Multiple scattering of 5-30 keV electrons in evaporated metal films II: Range-energy relations  

Microsoft Academic Search

The ranges of electrons in evaporated films of aluminium, copper, silver and gold have been measured for incident energies E0 between 5 and 20 keV. From electron transmission measurements the maximum range and the extrapolated range were determined. Energy loss measurements gave the mean range and the Thomson-Whiddington range, corresponding to the mean energy Em and the most probable energy

V. E. Cosslett; R. N. Thomas

1964-01-01

30

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

31

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

32

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

33

The XMM deep survey in the CDF-S. II. A 9-20 keV selection of heavily obscured active galaxies at z > 1.7  

NASA Astrophysics Data System (ADS)

We present results on a search of heavily obscured active galaxies z > 1.7 using the rest-frame 9-20 keV excess for X-ray sources detected in the deep XMM-CDFS survey. Out of 176 sources selected with the conservative detection criteria (>8?) in the first source catalogue of Ranalli et al. (in prep.), 46 objects lie in the redshift range of interest with the median redshift ˜ z? 2.5 ? 2.5. Their typical rest-frame 10-20 keV luminosity is 1044 erg s-1, as observed. Among optically faint objects that lack spectroscopic redshift, four were found to be strongly absorbed X-ray sources, and the enhanced Fe K emission or absorption features in their X-ray spectra were used to obtain X-ray spectroscopic redshifts. Using the X-ray colour-colour diagram based on the rest-frame 3-5 keV, 5-9 keV, and 9-20 keV bands, seven objects were selected for their 9-20 keV excess and were found to be strongly absorbed X-ray sources with column density of NH ? 0.6 × 1024 cm-2, including two possible Compton thick sources. While they are emitting at quasar luminosity, ~3/4 of the sample objects are found to be absorbed by NH > 1022 cm-2. A comparison with local AGN at the matched luminosity suggests an increasing trend of the absorbed source fraction for high-luminosity AGN towards high redshifts.

Iwasawa, K.; Gilli, R.; Vignali, C.; Comastri, A.; Brandt, W. N.; Ranalli, P.; Vito, F.; Cappelluti, N.; Carrera, F. J.; Falocco, S.; Georgantopoulos, I.; Mainieri, V.; Paolillo, M.

2012-10-01

34

Elastic electron scattering and vibrational excitation of isoxazole molecules in the energy range from 2 to 20 eV  

NASA Astrophysics Data System (ADS)

Differential cross sections for elastic electron scattering and the excitation of the C-H vibrational modes of isoxazole molecules were measured in the energy range from 2 to 20 eV and over the scattering angle range from 10° to 180°. The cross sections at the scattering angles of and above 90° were accessible with the use of a magnetic angle changer. The differential cross sections were integrated to yield integral and momentum transfer cross sections. The negative ion resonances in the elastic scattering at 2.7 eV and in the vibrational excitation of isoxazole at 5.5 and 10 eV were observed. The present cross sections for elastic scattering are compared with the corresponding results in furan.

Linert, Ireneusz; Zubek, Mariusz

2012-08-01

35

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

36

Thermodynamic properties of fluid (4)He in the 75 to 300 K and 2- to 20-kbar range  

NASA Astrophysics Data System (ADS)

Pressure, volume, temperature, and sound velocity measurements of He-4 on (4)He in the ranges 75 to 300 (0)K and 2 to 20 kbar are presented. From an equation of state fitted to these data, the thermodynamic quantities: volume, sound velocity, thermal expansivity, heat capacity at constant pressure, the ratio of specific heats, adiabatic compressibility, and molar entropy are calculated and tabulated. Computer-drawn graphs of the isothermal pressure variation of these quantities are presented and the precision of the fits to the data is discussed. Comparison with other measurements is described in the limited region of overlap, that is, at less than 10 kbar and near room temperature.

Liebenberg, D. H.; Mills, R. L.; Bronson, J. C.

1980-10-01

37

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

PubMed

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

Tereshchenko, Evgeny E; Moiseev, Nikolay

2012-09-01

38

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

NASA Astrophysics Data System (ADS)

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

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

2006-06-01

39

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

40

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

NASA Astrophysics Data System (ADS)

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

Midgley, S. M.

2013-02-01

41

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

PubMed

A nonlinear model for the x-ray linear attenuation coefficient ? is employed for dual energy x-ray analysis (DEXA). Nonlinear simultaneous equations formed by ? and energy dependent model parameters are solved for the electron density N(e) and fourth compositional ratio R(4) which has the same 'units' as the atomic number. Computed tomography data was acquired at 20-35 keV using bending magnet synchrotron radiation, a double crystal monochromator, a rotation stage and an area detector. Test objects contained liquid samples as mixtures of ethanol, water and salt solutions with known density and composition. Various noise sources are identified and give ? uncertainties of 1-2%. A fan beam geometry allowed the detection of forward scattered radiation with measured ? being 6% lower than expectations for a narrow beam. Energy dependent model parameters were obtained by solving linear simultaneous equations formed by ? and material parameters based upon N(e) and R(4). DEXA accuracy was studied as a function of photon energy and sample composition. Propagation of errors analysis identifies the importance of the fractional compositional cross-products whose difference at the two beam energies should exceed 0.1, requiring 10 keV or more separation. For a reasonable approximation for the adjustable model parameters, the mean difference between the DEXA solution and true values (?N(e), ?R(4)) are (1.0%, 0.5%) for soft tissue and (1.5%, 0.8%) for bone like samples. PMID:23369847

Midgley, S M

2013-02-21

42

Characterization of Zone Plate Properties using Monochromatic Synchrotron Radiation in the 2 to 20 nm Wavelength Range  

SciTech Connect

A zone plate composed of Mo zones having 4 mm outermost zone diameter, 100 nm outermost zone width, and supported on a silicon nitride membrane was characterized using monochromatic synchrotron radiation in the 2 to 20 nm wavelength range. The zero and first order efficiencies were measured and compared to ab initio calculations that account for the optical properties of the materials, the width and shape of the zones, and multiple-layer thin-film effects. It is shown that the thicknesses of the Mo zones and the membrane and the ratio of the zone width to zone period can be independently determined from the measured diffraction efficiencies in the zero and first orders and that the computational code can be used to reliably design zone plates that are optimized for applications such as solar irradiance monitors in the extreme ultraviolet region.

J Seely; B Kjornrattanawanich; L Goray; Y Feng; J Bremer

2011-12-31

43

Characterization of zone plate properties using monochromatic synchrotron radiation in the 2 to 20 nm wavelength range.  

PubMed

A zone plate composed of Mo zones having 4 mm outermost zone diameter, 100 nm outermost zone width, and supported on a silicon nitride membrane was characterized using monochromatic synchrotron radiation in the 2 to 20 nm wavelength range. The zero and first order efficiencies were measured and compared to ab initio calculations that account for the optical properties of the materials, the width and shape of the zones, and multiple-layer thin-film effects. It is shown that the thicknesses of the Mo zones and the membrane and the ratio of the zone width to zone period can be independently determined from the measured diffraction efficiencies in the zero and first orders and that the computational code can be used to reliably design zone plates that are optimized for applications such as solar irradiance monitors in the extreme ultraviolet region. PMID:21691369

Seely, John; Kjornrattanawanich, Benjawan; Goray, Leonid; Feng, Yan; Bremer, James

2011-06-20

44

Characterization of zone plate properties using monochromatic synchrotron radiation in the 2 to 20 nm wavelength range  

SciTech Connect

A zone plate composed of Mo zones having 4 mm outermost zone diameter, 100 nm outermost zone width, and supported on a silicon nitride membrane was characterized using monochromatic synchrotron radiation in the 2 to 20 nm wavelength range. The zero and first order efficiencies were measured and compared to ab initio calculations that account for the optical properties of the materials, the width and shape of the zones, and multiple-layer thin-film effects. It is shown that the thicknesses of the Mo zones and the membrane and the ratio of the zone width to zone period can be independently determined from the measured diffraction efficiencies in the zero and first orders and that the computational code can be used to reliably design zone plates that are optimized for applications such as solar irradiance monitors in the extreme ultraviolet region.

Seely, John; Kjornrattanawanich, Benjawan; Goray, Leonid; Feng Yan; Bremer, James

2011-06-20

45

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

46

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

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

47

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

Microsoft Academic Search

We are studying the feasibility of utilizing Kα x-ray sources in the range of 20 to 100 keV as a backlighters for imaging various stages of implosions and high areal density planar samples driven by the NIF laser facility. The hard x-ray Kα sources are created by relativistic electron plasma interactions in the target material after a radiation by short

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

2003-01-01

48

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

SciTech Connect

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

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

2005-08-29

49

X-Ray Attenuation of Silicon in the Energy Range 25 - 50 KeV.  

National Technical Information Service (NTIS)

Precise measurements of the X-ray attenuation coefficient of crystalline silicon have been made in the energy range 25 to 50 keV. A systematic discrepancy between theory and experiment is observed. The most likely cause of the disagreement is thought to b...

J. F. Mika Z. Barnea

1984-01-01

50

Thermoluminescent response of TLD-100 irradiated with 20 keV electrons and the use of radiochromic dye films for the fluence determination  

NASA Astrophysics Data System (ADS)

We have measured the LiF:Mg,Ti (TLD-100) fluence response and supralinearity function to 20 keV electrons in the fluence interval between 5 × 10 9 and 4 × 10 12 cm -2. TLD-100 shows linear response up to 2 × 10 10 cm -2, followed by supralinearity and saturation after 10 12 cm -2. Peak 5 is slightly supralinear, f( n) max=1.1±0.1, while high temperature peaks reach up to f( n) max?8. Peak 5 saturates at n?1×10 11 cm -2, fluence smaller than any of the saturating fluences of the high temperature peaks. We have also measured the glow curve shape of TLD-100 irradiated with 40 keV electrons, beta particles from a 90Sr/ 90Y source and 1.3 and 6.0 MeV electrons from accelerators. Results are interesting and unexpected in that, for a given macroscopic dose, electrons show a smaller relative contribution of high-temperature peaks with respect to peak 5 than heavy ions or X- and ?-rays. The 20 and 40 keV electron irradiations were performed with a scanning electron microscope using radiochromic dye film to measure fluence. Since film calibrations were performed using 60Co ?-rays which expose the totality of the film volume, the use of this method with low energy electrons required to develop a formalism that takes into account the sensitive thickness of the film in relation to the range of the incident particles.

Mercado-Uribe, H.; Brandan, M. E.

2004-07-01

51

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

52

An experimental and theoretical study of electronic excitation and charge transfer processes in collisions between Cs( 6 2 S 1\\/2 ) atoms and Na +( 1 S 0) ions in the 0.30–4.00 keV energy range  

Microsoft Academic Search

The collisional system Cs+Na+ with both species in their ground electronic state, has been studied using the crossed molecular beams technique and measuring the resulting fluorescent decay. Emissions from electronically excited Cs(62P3\\/2) and Cs(72P1\\/2,3\\/2) atoms have been detected as well as those from excited Na(32P1\\/2,3\\/2) and Na(42D3\\/2,5\\/2) produced by electron transfer. Cross-section values in the 0.30–4.00 keV energy range have

J. de Andrés; M. Sabidó; M. E. Aricha; M. Albert??; J. M. Lucas; F. X. Gadea; A. Aguilar

2002-01-01

53

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

SciTech Connect

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

Kruschwitz, Craig [NSTec; Wu, M. [SNL; Rochau, G. A. [SNL

2013-06-13

54

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

55

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

NASA Technical Reports Server (NTRS)

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

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

1990-01-01

56

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

NASA Astrophysics Data System (ADS)

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

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

2013-03-01

57

Centaurus A (NGC 5128) at 2 keV--2. 3 MeV: HEAO 1 observations and implications  

SciTech Connect

The nearby active-nucleus galaxy Centaurus A (NGC 5128) has been studied at 2 keV--2.3 MeV using data from both the UCSD/MIT hard X-ray and low energy ..gamma..-ray instrument and from the GSFC/CIT cosmic X-ray experiment on HEAO 1. We find that an E/sup -1.60plus-or-minus0.03/ power law spectrum breaking to E/sup -2.0plus-or-minus0.2/ at 140 keV best describes the 1978 January and July data. The average intensity was 50% higher during the January observations. We have searched our data for faster variations and set limits in several energy ranges over times from fractions of a day to several days. Upper limits to unresolved lines at 511 keV and 1.6 MeV are 6.5 x 10/sup -4/ photons cm/sup -2/ s/sup -1/ and 2.2 x 10/sup -4/ photons cm/sup -2/ s/sup -1/, respectively, at the 90% confidence level. Continuation of the observed power law to higher energies is used to constrain various models of energy generation in the nucleus of NGC 5128.

Baity, W.A.; Rothschild, R.E.; Lingenfelter, R.E.; Stein, W.A.; Nolan, P.L.; Gruber, D.E.; Knight, F.K.; Matteson, J.L.; Peterson, L.E.; Primini, F.A.; Levine, A.M.; Lewin, W.H.G.; Mushotzky, R.F.; Tennant, A.F.

1981-03-01

58

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

SciTech Connect

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

Kinney, J H; Haupt, D L

2002-07-01

59

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

60

Equation-of-state data for molecular hydrogen and deuterium at shock pressures in the range 2--76 GPa (20--760 kbar)  

SciTech Connect

Dynamic equation-of-state data for D/sub 2/ and H/sub 2/ were measured in the pressure range 2--76 GPa (20--760 kbar) using a two-state light-gas gun. Liquid specimens were shocked from initial states near the saturation curve at 20 K. Maximum compression was sixfold over initial liquid density at a calculated temperature of 7000 K for D/sub 2/. The data is discussed in terms of the theory of Ross et al., which includes an effective intermolecular pair potential, molecular vibration, free molecular rotation, and molecular dissociation.

Nellis, W.J.; Mitchell, A.C.; van Thiel, M.; Devine, G.J.; Trainor, R.J.; Brown, N.

1983-08-01

61

2-gamma decay of the 662-keV isomer in ^137Ba  

NASA Astrophysics Data System (ADS)

2-gamma decay of the 662-keV ^137Ba isomer following ^137Cs beta decay has been observed using two 3"x3" NaI detectors, a 20.5-?Ci source, and a Pb shielding geometry designed to minimize direct and sequential Compton scattering backgrounds. In runs totaling 144 days, a 662-keV peak has been observed in the profile across the diagonal connecting 662-keV axis points in a 2-dimensional coincidence pulse-height spectrum. A preliminary value of 2.0(6)x10-6 is derived for the 2-gamma/1-gamma intensity ratio. The distribution of 662-keV events along the 2D diagonal is a continuum centered at 331-331 keV with a shape favoring a double quadrupole E2-M2 or M2-E2 decay sequence. Our result compares with upper limits of < 10-5, our assessment of the Beusch experiment [1], and < 2.2x10-6 by Basenko et al. [2]. It will be compared with theoretical estimates. [4pt] [1] W. Beusch, Helv Phys. Acta 33, 363 (1960)[0pt] [2] V.K. Basenko, A.N. Berlizov, and G.A. Prokopets, Bull. Russ. Acad. Sci. 56, 94 (1992)

Millener, D. J.; Sutter, R. J.; Alburger, D. E.

2011-10-01

62

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

Friedman, P.G.

1986-01-01

63

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

64

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

SciTech Connect

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

Limbachiya, Chetan [P. S. Science College, Kadi 382 715, Gujarat (India); Vinodkumar, Minaxi [V. P. and R. P. T. P. Science College, Vallabh Vidyanagar 388 120, Gujarat (India); Mason, Nigel [Department of Physics and Astronomy, Open University, Milton Keynes, MK7 6AA (United Kingdom)

2011-04-15

65

Channeled and random proton stopping power in the 30-1000 keV energy range  

Microsoft Academic Search

The stopping power of 30- to 1000-keV protons transmitted through silicon in random and channeling (, , and ) directions has been determined. It was found that the stopping power for random and all channeling directions reaches a maximum at about 50 keV. At nearly the same energy the ratio of the channeled-to-random stopping has the maximum value. Present results

A. Carnera; G. Della Mea; A. V. Drigo; S. Lo Russo; P. Mazzoldi; G. G. Bentini

1978-01-01

66

The response of a thermoluminescent dosimeter to low energy protons in the range 30–100 keV  

Microsoft Academic Search

This study demonstrates the thermoluminescence (TL) response of CaF2:Tm (commercial name TLD-300) to 30–100keV protons which were generated by means of a Cockcroft–Walton accelerator. The phenomenon in which the total thermoluminescent output from CaF2:Tm (TLD-300) decreases with proton energy from 30 to 100keV (with increase of LET) can be interpreted by the track structure theory (TST). The analysis of the

Tieh-Chi Chu; Sung-Yen Lin; Chu-Chung Hsu; Jao-Perng Lin

2001-01-01

67

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

68

Calibration of the Galileo micro channel plate with the Xe7+ +Xe43+ ions in the energy range from 2 keV\\/1 up to 154 keV\\/q  

Microsoft Academic Search

The procedure of calibration of the detector assembly consisting of the two Galileo micro channel plates (MCPs) operated in a Chevron configuration is described. The current gains and the analog particle gains of the MCPs for Xe ions with charge states from q=7+ to q=43+ and ion impact energies to charge state ratios from 2 keV\\/q to 154 keV\\/q have

W. Mroz; D. Fry; A. Prokopuik; M. P. Stockli; B. Walch

1998-01-01

69

Spectral Constraints on SEYFERT-2 Galaxies as Major Contributors to the Hard 3-100-KEV X-Ray Background  

NASA Astrophysics Data System (ADS)

It has been suggested that the flat spectrum of the X-ray background (XRB) above 3 keV and below ~15 keV could be explained by the superposition of absorbed sources at different redshifts. To explain the steepening of the XRB spectrum above ~15 keV, the intrinsic source spectrum should cut off at ~50-100 keV, as observed in NGC 4151 and galactic black hole candidates. Here, assuming that Seyfert 2 galaxies are Seyfert 1 galaxies obscured by intervening matter in the line of sight, as postulated by the unified model, and that they provide the major contribution to the XRB in the 3-100 keV energy range, we derive some constraints on their spectrum and evolution, and indicate, in view of future ASCA measurements, the use of iron spectral features as a test of the model.

Matt, G.; Fabian, A. C.

1994-03-01

70

Flow behaviour of autoclaved, 20% cold worked, Zr-2.5Nb alloy pressure tube material in the temperature range of room temperature to 800 °C  

NASA Astrophysics Data System (ADS)

Pressure tube material of Indian Heavy Water Reactors is 20% cold-worked and stress relieved Zr-2.5Nb alloy. Inherent variability in the process parameters during the fabrication stages of pressure tube and also along the length of component have their effect on micro-structural and texture properties of the material, which in turn affect its strength parameters (yield strength and ultimate tensile strength) and flow characteristics. Data of tensile tests carried out in the temperature range from room temperature to 800 °C using the samples taken out from a single pressure tube have been used to develop correlations for characterizing the strength parameters' variation as a function of axial location along length of the tube and the test temperature. Applicability of Ramberg-Osgood, Holloman and Voce's correlations for defining the post yield behaviour of the material has been investigated. Effect of strain rate change on the deformation behaviour has also been studied.

Dureja, A. K.; Sinha, S. K.; Srivastava, Ankit; Sinha, R. K.; Chakravartty, J. K.; Seshu, P.; Pawaskar, D. N.

2011-05-01

71

Full-field microimaging with 8 keV X-rays achieves a spatial resolutions better than 20 nm.  

PubMed

Fresnel zone plates (450 nm thick Au, 25 nm outermost zone width) used as objective lenses in a full field transmission reached a spatial resolution better than 20 nm and 1.5% efficiency with 8 keV photons. Zernike phase contrast was also realized without compromising the resolution. These are very significant achievements in the rapid progress of high-aspect-ratio zone plate fabrication by combined electron beam lithography and electrodeposition. PMID:21997000

Chen, Tsung-Yu; Chen, Yu-Tung; Wang, Cheng-Liang; Kempson, Ivan M; Lee, Wah-Keat; Chu, Yong S; Hwu, Y; Margaritondo, G

2011-10-10

72

Angular Distributions and Total Yields of Bi Sputtered by 20 keV He^+, Ne^+ and Ar^+  

NASA Astrophysics Data System (ADS)

The angular distributions of neutral atoms sputtered from the surface of solid Bi by normally incident 20 keV He^+, Ne^+ and Ar^+ ions have been measured. The sputtered atoms were collected on pure aluminum foils under ultrahigh vacuum conditions, and the collector foils were subsequently analyzed using heavy ion Rutherford backscattering spectroscopy. The angular distributions obtained were integrated to determine the total sputtering yields of Bi for the different incident ions. Details of the measurements and data analysis are presented.

Deoli, Naresh; Phinney, Lucas; Pacheco, Jose; Weathers, Duncan

2011-03-01

73

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

NASA Astrophysics Data System (ADS)

Hind-limb suspension (HLS) of rats is a NASA validated model of simulated weightlessness. This study examines the effects of microgravity on the skeletal system of rats to assess whether or not exposure of rats to HLS for one week will induce alteration of structural features in selected bones. Four groups of rats were used: two unsuspended controls and two suspended groups. Body weight, food, and water intake were monitored daily before and after suspension. X-rays were measured by a liquid nitrogen cooled Si(li) detector on a Scanning Electron Microscope (SEM) that provided the 20 keV electron beam. X-ray data were collected from square cross sections between 100 ?m2 and 104 ?m2. The bones were measured for elemental levels of calcium, phosphorus, oxygen and carbon from both control and HLS rats. The average body weight of all HLS groups decreased compared to their respective unsuspended controls. Food and water intake was also lower in both suspended groups. A correlation among HLS and control samples in terms of the distribution of the primary elements was found in the bone tissue when analyzed as a function of position along the hind-leg and within the cross sections.

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

2010-04-01

74

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

NASA Astrophysics Data System (ADS)

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

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

2004-02-01

75

Web 2.0  

NASA Astrophysics Data System (ADS)

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

Gibson, Becky

76

Charge transfer between alkali cluster ions and atoms in the 1 to 10 keV collisional energy range  

Microsoft Academic Search

:   The cross-sections for collisional charge transfer between singly charged free clusters M\\u000a n\\u000a \\u000a + (M = Li, Na; n=1...50) and atomic targets A (cesium, potassium) have been measured as a function of collisional relative velocity in laboratory\\u000a energy range 1–10 keV. For each cluster size, the experimental values of the charge transfer cross-section are fitted with an universal parametric

C. Bréchignac; Ph. Cahuzac; B. Concina; J. Leygnier; I. Tignères

2000-01-01

77

Monochromatic focusing of subpicosecond x-ray pulses in the keV range  

NASA Astrophysics Data System (ADS)

An effective x-ray optical method to focus keV x-ray pulses shorter than one picosecond by using spherically or toroidally bent crystals is presented. The spectral, spatial, and time-dependent properties of focusing by two-dimensional bent crystals are calculated by considering geometrical effects, physical limitation in high performance crystal optics, and reflectivities obtained by x-ray diffraction theory. These properties are compared with first experimental results of focusing x rays from a plasma created by a laser pulse with 4.5 mJ energy and 100 fs pulse length. The x-ray signals, simultaneously obtained from a von Hámos spectrometer and two-dimensional bent crystals are compared and found in good agreement with theoretical data. The possibilities and aspects of laser pump x-ray probe experiments using this type of x-ray optics system and currently available laser systems are discussed.

Missalla, T.; Uschmann, I.; Förster, E.; Jenke, G.; von der Linde, D.

1999-02-01

78

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

79

Facilities and techniques for x-ray diagnostic calibration in the 100-eV to 100-keV energy range  

SciTech Connect

The Lawrence Livermore National Laboratory (LLNL) has been a pioneer in the field of x-ray diagnostic calibration for more than 20 years. We have built steady state x-ray sources capable of supplying fluorescent lines of high spectral purity in the 100-eV to 100-keV energy range, and these sources have been used in the calibration of x-ray detectors, mirrors, crystals, filters, and film. This paper discusses our calibration philosophy and techniques, and describes some of our x-ray sources. Examples of actual calibration data are presented as well.

Gaines, J.L.; Wittmayer, F.J.

1986-06-01

80

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

NASA Astrophysics Data System (ADS)

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

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

2001-04-01

81

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

82

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.

83

Electron-detachment spectroscopy of 20-100-keV H- projectiles interacting with thin Ar targets  

NASA Astrophysics Data System (ADS)

Energy and transformed-velocity spectra of electrons emitted in the forward direction have been experimentally determined for 20-120-keV H- projectiles traversing thin Ar targets. The spectra from H- are surprisingly cusplike in shape even though single-electron loss is known to dominate. In contrast to the findings of Menendez and Duncan, who performed similar measurements at higher projectile velocities, target-induced structures in the electron loss to the continuum spectra are not pronounced in this velocity regime.

Alton, G. D.; Compton, R. N.; Pegg, D. J.

1985-04-01

84

Zotero 2.0  

NSDL National Science Digital Library

For those trying to complete any lengthy citations (or even brief ones), Zotero will be a most welcome find. The program works as a Firefox 2.0 extension which helps users collect, manage, and cite research sources. As it functions within the browser itself, visitors can automatically capture citation information from web pages, and users can also take notes along the way as they work. The program also comes with complete documentation and is compatible with all computers running on either Windows or Mac operating systems.

2007-01-01

85

Awasu 2.0  

NSDL National Science Digital Library

Many individuals may want to keep in touch with news and website updates without constantly having to check up on each site individually, and this handy application is a good way to do just that. Awasu is a free news-reader that runs in the background and monitors news sites, along with providing updates from all types of sites as well, including weather updates and information about entertainment and other events. The application's homepage also features documentation for the application along with a detailed online help section. Awasu 2.0 is compatible with all systems running Windows 98 and above.

86

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

NASA Astrophysics Data System (ADS)

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

Kabadayi, Önder

87

X-ray attenuation coefficients and photoelectric cross sections of Cu, Fe and Sn for the energy range 3-29 KeV.  

National Technical Information Service (NTIS)

The document contains the following two papers: X-ray attenuation coefficient and photoelectric cross sections of Sn for the Energy Range 3.3 KeV to 29.1 KeV - by Wang Dachun, Yang Hua and Luo Pingan. X-ray attenuation coefficients and photoelectric cross...

Wang Dachun Yang Hua Luo Pingan Ding Xunliang Wang Xinfu

1991-01-01

88

City 2.0  

NSDL National Science Digital Library

TED's City 2.0 is "a gathering place for urban citizens to share innovations and inspire actions." The focus of this rather wonderful series of events was to work on envisioning the cities of the future. Visitors to the site will find archived videos from the devoted day of urban inspiration in 2012 and 2013 and they can click through the Videos area to get started. There are over two dozen talks here, including The Art of Data, Globalizing Home and Emerging from the Ecotone. Moving on to the People section, visitors can look over the stories shared from around the globe via the clickable map of the world. Visitors with a specific interest in a certain type of urban success story might want to use the Themes area to look over talks on art, housing, public space, or other matters.

2012-01-01

89

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

90

Axial and radial coefficients of thermal expansion of carbon fibers in the 20-430 C temperature range as derived from the thermal expansion of 1-D-C-SiO2(B2O3) composites  

Microsoft Academic Search

The axial and radial coefficients of thermal expansion (CTE) of HS (T300), HM (M40), and UHM (P100) carbon fibers have been computed, within the 20-430 C temperature range, from thermal expansion measurements performed on unidirectional composites with the fibers embedded in an isotropic glass SiO2-15 mol pct B2O3 matrix. The various CTE of the carbon fibers were found to be

E. Menessier; J. P. Dumont; A. Geutte; R. Pailler; L. Rabardel

1989-01-01

91

Feasibility study of hard-x-ray nanofocusing above 20 keV using compound photon sieves.  

PubMed

Combining the advantages of photon sieves (PSs) and compound Fresnel zone plates (CZPs), we designed compound photon sieves (CPSs) for hard-x-ray nanofocusing. A CPS consists of an inner PS using the first-order diffraction surrounded by an outer zone plate using the third-order diffraction. A robust digital prolate spheroidal window was used as an apodization window for the inner PS, making CPSs more flexible than CZPs. CPSs can provide not only slightly better resolution compared to CZPs, but also it can significantly suppress the sidelobes, leading to a high signal-to-noise ratio. Further improvement of the high-aspect-ratio metal nanostructure process will allow CPSs to be a promising candidate for hard-x-ray nanofocusing in the high-energy region above 20 keV. PMID:21124608

Xie, Changqing; Zhu, Xiaoli; Li, Hailiang; Shi, Lina; Wang, Yanhua

2010-12-01

92

Web 2.0, Meet Literacy 2.0  

ERIC Educational Resources Information Center

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

Penrod, Diane

2008-01-01

93

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

94

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

95

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

NASA Astrophysics Data System (ADS)

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

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

2006-10-01

96

3 keV to 2 MeV observations of four gamma-ray bursts  

Microsoft Academic Search

Simultaneous X and gamma ray spectra were obtained for four gamma ray burst events using satellite instrumentation. The P78-1 satellite proportional counters recorded X-ray data in the 3-10 keV range, while Pioneer Venus Orbiter and ISEE 3 sensors had a 3 keV lower limit for events. The positively correlated data covered the events GB 790307, 790325, 790504, and 790731. The

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

1984-01-01

97

Search for Anomalous Scattering of keV Neutrons from H2O-D2O Mixtures  

NASA Astrophysics Data System (ADS)

We measured the neutron scattering intensities from pure liquid H2O relative to that of pure D2O and also relative to H2O-D2O mixtures, at room temperature. This study is relevant to the problem of quantum entanglement. The neutrons were generated from an electron Linac and the final energy of the scattered neutrons was fixed at 24.3 keV using a 20 cm thick pure iron filter. The scattering intensity ratios were found to agree with expected values deduced from the tabulated total cross sections within an accuracy of 3%. Thus no anomaly was observed.

Moreh, R.; Block, R. C.; Danon, Y.; Neumann, M.

2005-05-01

98

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

NASA Technical Reports Server (NTRS)

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

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

1981-01-01

99

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

100

A Novel Approach to Measure the Cross Section of the 18O(p, ?)15N Resonant Reaction in the 0-200 keV Energy Range  

NASA Astrophysics Data System (ADS)

The 18O(p, ?)15N reaction is of primary importance to pin down the uncertainties, due to nuclear physics input, affecting present-day models of asymptotic giant branch stars. Its reaction rate can modify both fluorine nucleosynthesis inside such stars and oxygen and nitrogen isotopic ratios, which allow one to constrain the proposed astrophysical scenarios. Thus, an indirect measurement of the low-energy region of the 18O(p, ?)15N reaction has been performed to access, for the first time, the range of relevance for astrophysical application. In particular, a full, high-accuracy spectroscopic study of the 20 and 90 keV resonances has been performed and the strengths deduced to evaluate the reaction rate and the consequences for astrophysics.

La Cognata, M.; Spitaleri, C.; Mukhamedzhanov, A.; Banu, A.; Cherubini, S.; Coc, A.; Crucillà, V.; Goldberg, V.; Gulino, M.; Irgaziev, B.; 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.; Tribble, R. E.; Trzaska, W.; Tumino, A.

2010-01-01

101

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

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

102

Swelling effects in Y2Ti2O7 pyrochlore irradiated with 400 keV Ne2+ ions  

NASA Astrophysics Data System (ADS)

Polycrystalline pyrochlore Y2Ti2O7 compounds were irradiated with 400 keV Ne2+ ions at cryogenic temperature (˜77 K) at fluences ranging from 5 × 1014 to 1 × 1016 ions/cm2, corresponding to a peak ballistic damage dose of ˜0.17-3.4 displacements per atom (dpa). Irradiation-induced structural evolution was examined using grazing incidence X-ray diffraction at X-ray incident angles from 0.25° to 3° and cross-sectional transmission electron microscopy. An apparent swelling effect was observed on the irradiation layer prior to the irradiated layer being amorphized. The swelling effect increased with increasing ion irradiation fluence. At an ion induced damage of 1.7 dpa, the irradiated layer started to be amorphized.

Li, Y. H.; Wang, Y. Q.; Valdez, J. A.; Tang, M.; Sickafus, K. E.

2012-03-01

103

CASPER Version 2.0  

NASA Technical Reports Server (NTRS)

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

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

2007-01-01

104

The colouration of CaF2 crystals by keV and GeV ions  

Microsoft Academic Search

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) )

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

2002-01-01

105

Observations of solar X-ray bursts in the energy range 5-15 keV  

NASA Technical Reports Server (NTRS)

Bursts of solar X-rays in the energy range 5-15 keV are associated with flares and are due to thermal emission from a hot coronal plasma. The results of the first study of a large sample of separate bursts, 197 events associated with subflares, and of a few events of importance 1 are presented. The observations were made by a proportional counter on the satellite OSO-7 from October, 1971 to June, 1972. In most cases, the temperature characterizing the X-ray spectrum rises impulsively at the onset of the burst and then declines slowly throughout the remainder of the burst. The emission measure rises exponentially with a time scale of 30-100 sec and then declines slowly on a time scale of the order of 1,000 sec. It is shown that the growth of the thermal energy in the flare plasma throughout the burst can be due to the heating of new cool material.

Datlowe, D. W.; Hudson, H. S.; Peterson, L. E.

1974-01-01

106

The 2-8 keV cosmic X-ray background spectrum as observed with XMM-Newton  

NASA Astrophysics Data System (ADS)

We have measured the spectrum of the Cosmic X-ray Background (CXB) in the 2-8 keV range with the high throughput EPIC/MOS instrument onboard XMM-Newton. A large sample of high galactic latitude observations was used, covering a total solid angle of 5.5 square degrees. Our study is based on a very careful characterization and subtraction of the instrumental background, which is crucial for a robust measurement of the faintest diffuse source of the X-ray sky. The CXB spectrum is consistent with a power law having a photon index ?=1.41 ± 0.06 and a normalization of 2.46 ± 0.09 photons cm-2 s-1 sr-1 keV-1 at 3 keV (˜11.6 photons cm-2 s-1 sr-1 keV-1 at 1 keV), corresponding to a 2-10 keV flux of (2.24 ± 0.16) × 10-11 erg cm-2 s-1 deg-1 (90% confidence level, including the absolute flux calibration uncertainty). Our results are in excellent agreement with two of the most recent CXB measurements, performed with BeppoSAX LECS/MECS data (Vecchi et al. \\cite{Vec99}) and with an independent analysis of XMM-Newton EPIC/MOS data (Lumb et al. \\cite{Lum02}), providing a very strong constraint to the absolute sky surface brightness in this energy range, so far affected by an ˜40% uncertainty. Our measurement implies that the fraction of CXB resolved by the recent deep X-ray observations in the 2-10 keV band is of 80 ± 7% (1?), suggesting the existence of a new population of faint sources, largely undetected within the current sensitivity limits of the deepest X-ray surveys. Based on observations with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA member states and the USA (NASA). Appendices A and B are only available in electronic form at http://www.edpsciences.org

De Luca, A.; Molendi, S.

2004-06-01

107

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

SciTech Connect

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

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

1981-09-29

108

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

NASA Astrophysics Data System (ADS)

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

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

2014-10-01

109

Range and Stopping Power Energy Relationships for 0.5-30 keV Electron Beams Slowing Down in Solids: Analytical Model  

NASA Astrophysics Data System (ADS)

The development of an analytical model for calculating the electron stopping power (SP) converging with the experimental data at lower energies is still not completed. The purpose of this work is to suggest a mathematical expression of the range and the stopping power of electrons impinging in solid targets in the energy range up to 30 keV based on the spherical geometric model [A. Bentabet, Vacuum86 (2012) 1855]. The results are in good agreement with those of the literature. The slight discrepancy between the obtained and both the theoretical and experimental results regarding the stopping power at very low energy (E<0.5 keV) is discussed.

Bentabet, A.

2014-01-01

110

Depth distribution of 2-keV helium-ion irradiation-induced cavities in nickel  

SciTech Connect

Transmission electron microscopy has been used to study the effect of total dose on the depth distribution of cavities (voids or bubbles) in nickel irradiated at 500/sup 0/C with 20-keV /sup 4/He/sup +/ ions. A transverse sectioning technique allowed us to obtain the entire depth distribution of cavities from a single specimen. The diameter, number density and volume fraction of cavities were measured as a function of depth from micrographs taken from samples sectioned parallel to the direction of the incident beam. Results for the doses at 2.9 x 10/sup 15/ and 2.9 x 10/sup 16/ ions/cm/sup 2/ show an increase in the average cavity diameter, number density and volume fraction with increasing dose. A further increase in dose from 2.9 x 10/sup 16/ to 2.9 x 10/sup 17/ ions/cm/sup 2/ also shows an increase in the average cavity diameter but a decrease in the number density. This observation is interpreted as evidence for the coalescence of cavities. 3 figures, 1 table.

Fenske, G.; Das, S.K.; Kaminsky, M.

1981-01-01

111

Low Background-Rate Detector for Ions in the 5 to 50 KeV Energy Range to Be Used for Radioisotope Dating with a Small Cyclotron.  

National Technical Information Service (NTIS)

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 ...

P. G. Friedman

1986-01-01

112

Spatiotemporal behavior of X-ray emission above 20 keV from a Z-pinch produced by wire-array implosion  

SciTech Connect

Results are presented from experimental studies of hard X-ray (HXR) emission in the photon energy range above 20 keV from dense radiating Z-pinch plasmas. The work is aimed at revealing the nature of fast-electron (electron beam) generation during the implosion of cylindrical and conical wire arrays in the Angara-5-1 facility at currents of up to 3 MA. It is found that the plasma implosion zippering caused by the inclination of wires affects the parameters of the HXR pulse emitted during the implosion of a conical array. It is shown that HXR emission correlates well with the decay of the plasma column near the cathode in the stagnation phase. HXR images of the pinch are produced by the bremsstrahlung of fast electrons generated during plasma column decay and interacting with plasma ions and the anode target. It is found that the use of conical arrays makes it possible to control the direction of plasma implosion zippering and the spatiotemporal and energy parameters of the pinch X-ray emission, in particular the X-ray yield. For wire array with diameters of 12 mm and linear masses of 200-400 {mu}g/cm, the current of the fast electron beam is 20 kA and its energy is 60 J, which is about 1/500 of the energy of the main soft X-ray pulse.

Aleksandrov, V. V.; Grabovski, E. V.; Gribov, A. N.; Gritsuk, A. N.; Medovshchikov, S. F.; Mitrofanov, K. N.; Oleinik, G. M. [Troitsk Institute for Innovation and Fusion Research (Russian Federation)

2009-02-15

113

Spatiotemporal behavior of X-ray emission above 20 keV from a Z-pinch produced by wire-array implosion  

NASA Astrophysics Data System (ADS)

Results are presented from experimental studies of hard X-ray (HXR) emission in the photon energy range above 20 keV from dense radiating Z-pinch plasmas. The work is aimed at revealing the nature of fast-electron (electron beam) generation during the implosion of cylindrical and conical wire arrays in the Angara-5-1 facility at currents of up to 3 MA. It is found that the plasma implosion zippering caused by the inclination of wires affects the parameters of the HXR pulse emitted during the implosion of a conical array. It is shown that HXR emission correlates well with the decay of the plasma column near the cathode in the stagnation phase. HXR images of the pinch are produced by the bremsstrahlung of fast electrons generated during plasma column decay and interacting with plasma ions and the anode target. It is found that the use of conical arrays makes it possible to control the direction of plasma implosion zippering and the spatiotemporal and energy parameters of the pinch X-ray emission, in particular the X-ray yield. For wire array with diameters of 12 mm and linear masses of 200-400 ?g/cm, the current of the fast electron beam is 20 kA and its energy is 60 J, which is about 1/500 of the energy of the main soft X-ray pulse.

Aleksandrov, V. V.; Grabovski, E. V.; Gribov, A. N.; Gritsuk, A. N.; Medovshchikov, S. F.; Mitrofanov, K. N.; Oleinik, G. M.

2009-02-01

114

Neutral dissociation dynamics of O2 in the photon range 14.26-15.20 eV studied by XUV laser pump and UV laser probe method  

NASA Astrophysics Data System (ADS)

An experimental study is presented on the neutral dissociation of O2 by XUV laser pump and UV laser (1+1) REMPI probe method. The dissociation channel for the production of O (5S) +O (3P) is observed for the first time and is much stronger than the dissociation channel O (3S) +O (3P).

Zhou, Yiyong; Meng, Qingnan; Mo, Yuxiang

2014-04-01

115

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

116

Hydrodynamic study of plasma amplifiers for soft-x-ray lasers: a transition in hydrodynamic behavior for plasma columns with widths ranging from 20 ?m to 2 mm.  

PubMed

Plasma-based seeded soft-x-ray lasers have the potential to generate high energy and highly coherent short pulse beams. Due to their high density, plasmas created by the interaction of an intense laser with a solid target should store the highest amount of energy density among all plasma amplifiers. Our previous numerical work with a two-dimensional (2D) adaptive mesh refinement hydrodynamic code demonstrated that careful tailoring of plasma shapes leads to a dramatic enhancement of both soft-x-ray laser output energy and pumping efficiency. Benchmarking of our 2D hydrodynamic code in previous experiments demonstrated a high level of confidence, allowing us to perform a full study with the aim of the way for 10-100 ?J seeded soft-x-ray lasers. In this paper, we describe in detail the mechanisms that drive the hydrodynamics of plasma columns. We observed transitions between narrow plasmas, where very strong bidimensional flow prevents them from storing energy, to large plasmas that store a high amount of energy. Millimeter-sized plasmas are outstanding amplifiers, but they have the limitation of transverse lasing. In this paper, we provide a preliminary solution to this problem. PMID:21230603

Oliva, Eduardo; Zeitoun, Philippe; Velarde, Pedro; Fajardo, Marta; Cassou, Kevin; Ros, David; Sebban, Stephan; Portillo, David; le Pape, Sebastien

2010-11-01

117

The BeppoSAX 2-10 keV Survey (Giommi+, 2000)  

NASA Astrophysics Data System (ADS)

File table contains the name of the sources, their coordinates (J2000.0) and the measured flux detected by the BeppoSAX MECS instrument in the 2-10 keV energy band. Additional information (other designation, class and redshift) if available in literature is also provided. (1 data file).

Giommi, P.; Perri, M.; Fiore, F.

2000-11-01

118

Absolute detection efficiency of a micro-channel plate detector to x-rays in the 1--100 KeV energy range  

SciTech Connect

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

Burginyon, G.A.; Jacoby, B.A.; Wobser, J.K.; Ernst, R.D.; Ancheta, D.S.; Tirsell, K.G.

1992-09-03

119

Experimental thick-target bremsstrahlung spectra from electrons in the range 10 to 30 keV  

Microsoft Academic Search

The x-ray spectra produced by the bombardment of thick targets with monoenergetic electrons between 10 and 30 keV have been determined as a function of the incident and emission angles. Spectra have been obtained for Al, Cu, Mo, and W using a Si(Li) detector. The electron current absorbed in the target was measured and corrected for backscattering, allowing a determination

J. G. Chervenak; A. Liuzzi

1975-01-01

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

The BeppoSAX 2-10 keV survey  

NASA Astrophysics Data System (ADS)

We present the results of a 2-10 keV BeppoSAX survey based on 140 high galactic latitude MECS fields, 12 of which are deep exposures of ``blank'' parts of the sky. The limiting sensitivity is 5*E-14 erg cm -2s-1 where about 25% of the Cosmic X-ray Background (CXB) is resolved into discrete sources. The logN-logS function, built with a statistically complete sample of 177 sources, is steep and in good agreement with the counts derived from ASCA surveys. A CXB fluctuation analysis allowed us to probe the logN-logS down to about 1.5*E-14 erg cm -2s-1 where the contribution of discrete sources to the CXB grows to ~ 40-50%. A hardness ratio analysis reveals the presence of a wide range of spectral shapes and that a fairly large fraction of sources appear to be heavily absorbed, some of which showing soft components. A comparison of the flux distribution of different subsamples confirms the existence of a spectral hardening with decreasing flux. This effect is probably due to an increasing percentage of absorbed sources at faint fluxes, rather than to a gradual flattening of the spectral slope. Nearly all the sources for which adequate ROSAT exposures exist, have been detected in the soft X-rays. This confirms that soft spectral components are present even in strongly absorbed objects, and that a large population of sources undetectable below a few keV does not exist. A Ve/Va test provides evidence for the presence of cosmological evolution of a magnitude similar to that found in soft X-ray extragalactic sources. Evolution is present both in normal and absorbed sources, with the latter population possibly evolving faster, although this effect could also be the result of complex selection effects. Table 1 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html

Giommi, P.; Perri, M.; Fiore, F.

2000-10-01

122

Modeling of synchrotron reflectance calibrations of AXAF iridium-coated witness mirrors over 2 to 12 keV  

NASA Astrophysics Data System (ADS)

As calibrations of AXAF mirrors in the 2-12 keV range are near completion, we can report that the archive is complete for the scheduled number of mirrors over the 5-12 keV range, and also over the 2010-6200 eV range. Analysis of the results for optical constants and coating layer parameters is now proceeding rapidly. To date, we have derived optical constants from 39 mirrors over 5-12 keV using our existing Fresnel Equation model, with uniform layers of Ir, Cr, and Zerodur, and the roughness algorithm of Nevot and Croce. The analysis method has been presented in our earlier papers, but its application has been expanded to all three varieties of witness mirrors use in AXAF's qualification and production coating runs. For the first and most consistent variety, which have 1 angstrom roughness, reflectances are indistinguishable from mirror to mirror save for thickness variations between coating runs. Residuals of the fits for optical constants become large when reflectance values below 18 percent are included in the fits. If such data points are ignored, values of (delta) (E) and (beta) (E) very much like those of Henke et al. over 5-11 keV are obtained. Residuals are at the 0.6-0.8 percent level, which meets calibration requirements but exceeds experimental noise. For the second variety of witness mirror, polished to obtain roughness specification similar to the flight mirrors, fits approximately within the noise level of the measurements may be obtained over 5-11 keV, for reflectance values down to 5 percent. The (delta) (E) is essentially the same as that obtained from the 1 angstrom flats; however (beta) (E) is higher by approximately 3-4 percent systematically, and the mirror-to-mirror variation is larger. The third variety of mirror was obtained with 5-7 angstrom nominal roughness. Residuals to the fits are large for the entire range of angles, in some case exceeding 2 percent with a sinusoidal character through the critical angle. Coating layer depths are similar to those found for the other mirror types, with good precision. We discuss results along with possible improvements to the model and experiments to verify it.

Graessle, Dale E.; Blake, Richard L.; Burek, Anthony J.; Dyson, S. E.; Fitch, Jonathan J.; Schwartz, Daniel A.; Soufli, Regina

1998-11-01

123

Analytic Morse/long-range potential energy surfaces and predicted infrared spectra for CO-H2 dimer and frequency shifts of CO in (para-H2)N N = 1-20 clusters  

NASA Astrophysics Data System (ADS)

A five-dimensional ab initio potential energy surface (PES) for CO-H2 that explicitly incorporates dependence on the stretch coordinate of the CO monomer has been calculated. Analytic four-dimensional PESs are obtained by least-squares fitting vibrationally averaged interaction energies for vCO = 0 and 1 to the Morse/long-range potential function form. These fits to 30 206 points have root-mean-square (RMS) deviations of 0.087 and 0.082 cm-1, and require only 196 parameters. The resulting vibrationally averaged PESs provide good representations of the experimental infrared data: for infrared transitions of para H2-CO and ortho H2-CO, the RMS discrepancies are only 0.007 and 0.023 cm-1, which are almost in the same accuracy as those values of 0.010 and 0.018 cm-1 obtained from full six-dimensional ab initio PESs of V12 [P. Jankowski, A. R. W. McKellar, and K. Szalewicz, Science 336, 1147 (2012)]. The calculated infrared band origin shift associated with the fundamental of CO is -0.179 cm-1 for para H2-CO, which is the same value as that extrapolated experimental value, and slightly better than the value of -0.176 cm-1 obtained from V12 PESs. With these potentials, the path integral Monte Carlo algorithm and a first order perturbation theory estimate are used to simulate the CO vibrational band origin frequency shifts of CO in (para H2)N-CO clusters for N = 1-20. The predicted vibrational frequency shifts are in excellent agreement with available experimental observations. Comparisons are also made between these model potentials.

Li, Hui; Zhang, Xiao-Long; Le Roy, Robert J.; Roy, Pierre-Nicholas

2013-10-01

124

Analytic Morse/long-range potential energy surfaces and predicted infrared spectra for CO-H2 dimer and frequency shifts of CO in (para-H2)N N = 1-20 clusters.  

PubMed

A five-dimensional ab initio potential energy surface (PES) for CO-H2 that explicitly incorporates dependence on the stretch coordinate of the CO monomer has been calculated. Analytic four-dimensional PESs are obtained by least-squares fitting vibrationally averaged interaction energies for ?vCO = 0? and 1 to the Morse/long-range potential function form. These fits to 30,206 points have root-mean-square (RMS) deviations of 0.087 and 0.082 cm(-1), and require only 196 parameters. The resulting vibrationally averaged PESs provide good representations of the experimental infrared data: for infrared transitions of para?H2-CO and ortho?H2-CO, the RMS discrepancies are only 0.007 and 0.023 cm(-1), which are almost in the same accuracy as those values of 0.010 and 0.018 cm(-1) obtained from full six-dimensional ab initio PESs of V12 [P. Jankowski, A. R. W. McKellar, and K. Szalewicz, Science 336, 1147 (2012)]. The calculated infrared band origin shift associated with the fundamental of CO is -0.179 cm(-1) for para?H2-CO, which is the same value as that extrapolated experimental value, and slightly better than the value of -0.176 cm(-1) obtained from V12 PESs. With these potentials, the path integral Monte Carlo algorithm and a first order perturbation theory estimate are used to simulate the CO vibrational band origin frequency shifts of CO in (para?H2)N-CO clusters for N = 1-20. The predicted vibrational frequency shifts are in excellent agreement with available experimental observations. Comparisons are also made between these model potentials. PMID:24182037

Li, Hui; Zhang, Xiao-Long; Le Roy, Robert J; Roy, Pierre-Nicholas

2013-10-28

125

On the vectorial photoelectric effect at 2.69 keV  

Microsoft Academic Search

Recent experiments conducted to study the vectorial photoelectric effect with CsI, Al2O3 and Si photocathodes at 2.69 keV indicate null results. Detailed analysis shows that previously measured modulation can be well explained by geometrical misalignment and a combination of the asymmetric shape of the incident X-ray beam and a small detection area of the photoelectron detector. After the elimination of

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

1991-01-01

126

Critical currents of superconducting BiPbSrCaCuO tapes in the magnetic flux density range 0--19. 75 T at 4. 2, 15, and 20 K  

SciTech Connect

Critical currents of superconducting silver-sheathed tapes of Bi{sub 1.8}Pb{sub 0.4}Sr{sub 2}Ca{sub 2.2}Cu{sub 3}O{sub {ital x}} have been measured in the magnetic flux density range 0--19.75 T at 4.2, 15, and 20 K. One tape achieved a critical current of 60.6 A at 19.75 T and 20 K; the corresponding critical current density is 551 A/mm{sup 2}. In the same field, the tape has critical currents of 72.3 A (657 A/mm{sup 2}) at 15 K and 94.2 A (856 A/mm{sup 2}) at 4.2 K. At 77 K and in zero field, the tape carries 32.9 A (299 A/mm{sup 2}). These results indicate that high {ital T}{sub {ital c}}'' superconducting magnets of engineering interest may soon be feasible.

Sato, K.; Hikata, T. (Osaka Research Laboratories, Sumitomo Electric Industries, Osaka (Japan)); Iwasa, Y. (Francis Bitter National Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, MA (USA))

1990-10-29

127

Absolute detection efficiency of a micro-channel plate detector to x-rays in the 1--100 KeV energy range  

Microsoft Academic Search

There is little information in the literature on the performance of working micro-channel plate (MCP) detectors at high x-ray energies. We have measured the absolute efficiency of a microchannel-plate-intensified, subnanosecond, one dimensional unaging x-ray detector developed at LLNL in the 1 to 100 keV range and at 1.25 MeV. The detector consists of a gold photocathode deposited on the front

G. A. Burginyon; B. A. Jacoby; J. K. Wobser; R. D. Ernst; D. S. Ancheta; K. G. Tirsell

1992-01-01

128

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

Microsoft Academic Search

There is little information in the literature on the performance of working micro-channel plate (MCP) detectors at high x-ray energies. We have measured the absolute efficiency of a microchannel-plate-intensified, subnanosecond, one dimensional imaging x-ray detector developed at LLNL in the 1 to 100 keV range and at 1.25 MeV. The detector consists of a gold photocathode deposited on the front

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

1993-01-01

129

Absolute detection efficiency of a micro-channel plate detector to X-rays in the 1 - 100 keV energy range  

Microsoft Academic Search

There is little information in the literature on the performance of working micro-channel plate (MCP) detectors at high X-ray energies. The authors have measured the absolute efficiency of a microchannel-plate-intensified, subnanosecond, one dimensional imaging X-ray detector in the 1 to 100 keV range and at 1.25 MeV. The detector consists of a gold photocathode deposited on the front surface of

G. A. Burginyon; B. A. Jacoby; J. K. Wobser; R. D. Ernst; D. S. Ancheta; K. G. Tirsell

1993-01-01

130

The 2-10 keV emission properties of PSR B1937+21  

NASA Astrophysics Data System (ADS)

We present the results of a BeppoSAX observation of the fastest pulsar known: PSR B1937+21. The ~ 200 ks observation (78.5 (34) ks MECS (LECS) exposure times) allowed us to investigate with high statistical significance both the spectral properties and the pulse profile shape. The absorbed power law spectral model gave a photon index of ~1.7 and NH ~ 2.3 x 1022 cm-2. These values explain both a.) the ROSAT non-detection and b.) the deviant estimate of a photon index of 0.8 obtained by ASCA. The pulse profile appears, for the first time, clearly double peaked with the main component much stronger than the other. The statistical significance is 10 sigma (main peak) and 5 sigma (secondary peak). The 1.6-10 keV pulsed fraction is consistent with 100%; only in the 1.6-4 keV band there is a ~ 2sigma indication for a DC component. The secondary peak is detected significantly only for energies above 3-4 keV. The unabsorbed (2-10 keV) flux is F2-10 = 3.7 x 10-13 \\fu, implying a luminosity of LX = 4.6 x 1031 Theta (d/3.6 kpc)2 erg s-1 and an X-ray efficiency of ? = 4× 10-5, Theta, where Theta is the solid angle spanned by the emission beam. These results are in agreement with those obtained by ASCA.

Nicastro, L.; Cusumano, G.; Kuiper, L.; Becker, W.; Hermsen, W.; Kramer, M.

131

Measurement of the ^17O(p,?)^18F nuclear reaction cross section in the energy range Elab=360 - 1625 keV  

NASA Astrophysics Data System (ADS)

The ^17O(p,?)^18F reaction influences hydrogen-burning nucleosynthesis in several stellar sites, such as red giants, asymptotic giant branch (AGB) stars, massive stars and classical novae. In the relevant temperature range for these environments (T9=0.01-0.4), the main contributions to the rate of this reaction are the direct capture process, two low lying narrow resonances (ER^lab=70 and 193 keV) and the low energy tails of two broad resonances (ER^lab=587 and 714 keV). Previous measurements and calculations give contradictory results for the direct capture contribution which in turn increases the uncertainty of the reaction rate. In addition, very few published cross section data exist for the high energy region that might affect the interpretation of the direct capture and the broad resonances contributions in the lower energy range. In this work we present a measurement of the reaction at a wide proton energy range (Elab=360 - 1625 keV) and at several angles (?lab=0^o,45^o,90^o,135^o). All detected primary transitions and all angles were fitted simultaneously and extrapolated to lower energies using the multi-level, multi-channel R-matrix code, AZURE.

Kontos, Antonios; Görres, Joachim; Best, Andreas; Li, Qian; Schürmann, Daniel; Stech, Ed; Uberseder, Ethan; Wiescher, Michael; Imbriani, Gianluca; Azuma, Richard

2011-10-01

132

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

133

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

Microsoft Academic Search

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 400 keV. Although the Ginga and

E. E. Fenimore

1999-01-01

134

Academic Leadership 2.0  

ERIC Educational Resources Information Center

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

Buller, Jeffrey L.

2013-01-01

135

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

136

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

137

Introducing Science 2.0!  

ERIC Educational Resources Information Center

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

Brunsell, Eric; Horejsi, Martin

2010-01-01

138

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

139

Preliminary evaluation of the /sup 235/U(n,f) cross-section from 100 keV to 20 MeV  

SciTech Connect

A preliminary evaluation of the fission cross-section of /sup 235/U from 100 keV to 20 MeV is described. Variance-covariance matrices for a number of experimental data sets were constructed and used to evaluate the fission cross-section following a Bayesian procedure. The evaluated fission cross-section is compared with experimental data including the /sup 252/Cf fission neutron spectrum averages and some of the problems encountered in carrying out the fit are discussed.

Bhat, M.R.

1983-01-01

140

On the vectorial photoelectric effect at 2.69 keV  

NASA Technical Reports Server (NTRS)

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

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

1991-01-01

141

On the vectorial photoelectric effect at 2.69 keV  

NASA Astrophysics Data System (ADS)

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

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

1991-11-01

142

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

143

Absolute detection efficiency of a micro-channel plate detector to x-rays in the 1--100 KeV energy range  

SciTech Connect

There is little information in the literature on the performance of working micro-channel plate (MCP) detectors at high x-ray energies. We have measured the absolute efficiency of a microchannel-plate-intensified, subnanosecond, one dimensional unaging x-ray detector developed at LLNL in the 1 to 100 keV range and at 1.25 MeV. The detector consists of a gold photocathode deposited on the front surface of the MCP (optimized for Ni K[sub [alpha

Burginyon, G.A.; Jacoby, B.A.; Wobser, J.K.; Ernst, R.D.; Ancheta, D.S.; Tirsell, K.G.

1992-09-03

144

W values of protons in alkane-based TE gases and dimethylether in the energy range 1-100 keV: measurements and additivity models.  

PubMed

W values of tissue-equivalent gases based on propane and butane were measured for protons in the energy range 1-100 keV and compared with those of dimethylether and water vapour. The experimental values of the tissue-equivalent gas mixtures were compared with data calculated from the W values of the mixture components using five existing additivity models and two new models derived within the scope of the present work. Apart from one model--the simplest one--all models show a good agreement with the experimental data. PMID:15353623

Baek, W Y; Grosswendt, B; Willems, G

2004-01-01

145

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

146

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

NASA Technical Reports Server (NTRS)

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

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

1975-01-01

147

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

148

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

149

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

NASA Astrophysics Data System (ADS)

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

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

2010-07-01

150

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

151

Study of BaF2 with 511 KeV Gamma Rays  

NASA Astrophysics Data System (ADS)

Results will be presented on tests conducted with a 20 Torr ethane 1000 Angstrom cesium-iodide photocathode avalanche chamber [1], with a barium-fluoride scintillator window. Positrons are emitted from a sodium-22 source, which annihilate to produce two 0.511 MeV gamma rays. The barium-fluoride scintillator window converts the 0.511 MeV gamma rays into ultraviolet wavelength photons, which are absorbed in the cesium-iodide photocathode. The detector is sensitive to photon wavelengths between 170 and 220 nanometers, with a peak quantum efficiency of 16% at 170 nanometers. The quantum efficiency falls with increased wavelength [2]. Photoelectrons from the cesium-iodide photocathode are multiplied as they are accelerated through 1.5 mm of ethane at 20 Torr by a potential difference ranging between 450 and 550 Volts. If performance is acceptable, this technique could be used in medical imaging applications, such as in a full-body PET scanner, as a replacement for photomultiplier tubes. A Monte Carlo program has been written to describe the detector and processes and results will be presented. REF. [1] M. Staric, et al., Detection of Fast BaF2 Scintillations With a CsI Photocathode Coupled to a MWPC, IEEE Trans. Nucl. Sci., Vol.41, No.4, p742, August 1994. REF. [2] W. Kononenko and N. S. Lockyer, Substrate Studies of Cesium Iodide Photocathodes, July 1995, to be published in Nucl. Instr. and Meth..

Miller, Jon

1996-05-01

152

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

153

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

154

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

155

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

SciTech Connect

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

Gade, A.; Bowen, M. D.; Brown, B. A.; Campbell, C. M.; Cook, J. M.; Glasmacher, T.; McDaniel, S.; Siwek, K. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States); Adrich, P.; Bazin, D.; Obertelli, A.; Weisshaar, D. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); Hosier, K.; McGlinchery, D.; Riley, L. A. [Department of Physics and Astronomy, Ursinus College, Collegeville, Pennsylvania 19426 (United States)

2007-08-15

156

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

PubMed Central

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

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

2011-01-01

157

Irradiation of Cu(In,Ga)Se\\/sub 2\\/ thin film solar cells with 110-, 210-, and 290- keV protons  

Microsoft Academic Search

This study presents irradiation experiments of Cu(In,Ga)Se\\/sub 2\\/ thin-film solar cells using protons with energies of 110, 210, and 290 keV, i.e., in an energy range that is expected to cause maximum damage in the Cu(In,Ga)Se\\/sub 2\\/ absorber layer. Monte-Carlo simulations predict the average depth of the irradiation induced vacancies as well as the integral number of generated vacancies. From

K. Weinert; M. Schwickert; U. Rau

2003-01-01

158

Calibration of X-ray detectors in the 8 to 115 keV energy range and their application to diagnostics on the National Ignition Facility  

SciTech Connect

The calibration of X-ray diagnostics is of paramount importance to the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL). National Security Technologies LLC (NSTec) fills this need by providing a wide variety of calibration and diagnostic development services in support of the ongoing research efforts at NIF. The X-ray source in the High Energy X-ray lab utilizes induced fluorescence in a variety of metal foils to produce a beam of characteristic X rays ranging from 8 to 111 keV. Presented are the methods used for calibrating a High Purity Germanium detector, which has been absolutely calibrated using radioactive check sources, compared against a silicon photodiode calibrated at Physikalisch Technische Bundesanstalt (PTB). Also included is a limited presentation of results from the recent calibration of the upgraded Filter Fluorescer X ray Spectrometer.

J. J. Lee, M. J. Haugh, G. LaCaille, and P. Torres

2012-10-01

159

Calibrating of x-ray detectors in the 8 to 111 keV energy range and their application to diagnostics on the National Ignition Facility  

NASA Astrophysics Data System (ADS)

The calibration of X-ray diagnostics is of paramount importance to the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL). National Security Technologies LLC (NSTec) fills this need by providing a wide variety of calibration and diagnostic development services in support of the ongoing research efforts at NIF. The Xray source in the High Energy X-ray lab utilizes induced fluorescence in a variety of metal foils to produce a beam of characteristic X-rays ranging from 8 to 111 keV. Presented are the methods used for calibrating a High Purity Germanium detector, using NIST traceable radioactive sources, and compared against a silicon photodiode calibrated at Physikalisch Technische Bundesanstalt (PTB). A limited presentation of results from the recent calibration of the upgraded Filter Fluorescer X-ray Spectrometer is included.

Lee, Joshua J.; Haugh, Michael J.; LaCaille, Greg; Torres, Peter

2012-10-01

160

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

161

Charge transfer of 0.2-5.0 keV protons and hydrogen atoms in sodium-, potassium- and rubidium-vapour targets  

Microsoft Academic Search

Total cross sections sigma +0 and sigma +- for single- and double-electron capture by protons, and total cross sections sigma 0- and sigma 0+ for single-electron capture and single-electron loss by neutral hydrogen atoms in single collisions with atoms of sodium, potassium and rubidium have been measured in the energy range 0.2-5.0 keV. All electron capture cross sections show a

F. Ebel; E. Salzborn

1987-01-01

162

Electron-ion\\/atom coincidence measurements of 3 keV He + interacting with a SiH(1 0 0)-(2 × 1) surface  

Microsoft Academic Search

An electron-scattered ion\\/atom coincidence technique has been developed and applied to the interaction of 3keV He+ ions with a Si(100)–(2×1)-H surface. The technique extends scattering and recoiling imaging spectrometry (SARIS) to include electron-scattered particle coincidence methods. The distributions of the scattered projectiles (He0 and He+) on a position-sensitive detector in the range of large scattering angles and in coincidence with

T. Ito; I. Bolotin; R. Zhang; B. Makarenko; B. Bahrim; J. W. Rabalais

2005-01-01

163

Cross sections for electron capture by Ne2+ in He, Ne, Ar, Kr and Xe between 60 and 200 keV  

Microsoft Academic Search

Measurements of the sigma 21 cross sections for Ne2+ ions in targets of helium, neon, argon, krypton and xenon have been made with an absolute accuracy of about 5% in the energy range between 60 and 200 keV. The two-state theory, in the form given by Rapp and Francis (1962) is able to account for the energy variation of the

H. C. Suk; A. Guilbaud; B. Hird

1978-01-01

164

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

165

ART: Surveying the Local Universe at 2-11 keV  

NASA Technical Reports Server (NTRS)

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

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

2008-01-01

166

Isotope effects in inelastic 1. 5-keV He/sup +hyphen/(H/sub 2/,D/sub 2/) collisions  

SciTech Connect

Linear- and circular-polarization measurements have been made for the 3 /sup 3/P..-->..2 /sup 3/S transitions in helium resulting from the collision processes, He/sup +/+H/sub 2/ /D/sub 2/..-->..He(3 /sup 3/P)+H/sub 2/ /sup +//D/sub 2/ /sup +/. This was carried out at an incident-ion lab energy of 1.5 keV and for laboratory scattering angles ranging from 0.50 to 2.33 deg. The behavior of linear polarization for H/sub 2/ and D/sub 2/ targets as a function of scattering angle was found to be different, contrary to what one would expect from simple models that depend only upon the electronic structure of the system. Some correlation of the circular polarization between the two isotopes was found.

Goldberger, A.L.; Jaecks, D.H.; Natarajan, M.; Fornari, L.

1984-01-01

167

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

168

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

169

BeppoSAX observations in the 2-100 keV band of the nearby Seyfert galaxies: an atlas of spectra  

NASA Astrophysics Data System (ADS)

An atlas of high energy (E?2 keV) spectra of nearby (z?0.1) Seyfert galaxies observed with BeppoSAX is presented. The data have been analyzed in an homogeneous way. The final sample contains BeppoSAX MECS+PDS (LECS data were not used here) pointings of 113 objects. No useful X-ray data were present for eight targets. The catalog of X-ray spectra contains data for 43 type-I Seyfert (including Seyfert 1.0, 1.2, and 1.5) and for 62 type-II objects (including Seyfert 1.8, 1.9, and 2.0). A total of 163 X-ray spectra (84 for type-I and 79 for type-II objects) were analyzed, since some sources were observed several times. 81 sources were detected at high energy (above 10 keV) by the PDS: 39 are Seyfert I and 42 are Seyfert II. The broadband X-ray spectra covering the ~2-100 keV band are 130 in total. In a forthcoming paper, the statistical analysis of these data will be presented.

Dadina, M.

2007-01-01

170

Thermal expansion of ChS-139 steel in temperature range 20-720 °C  

NASA Astrophysics Data System (ADS)

The article presents the results of investigation of thermal expansion of ChS-139 steel in the temperature range 20-720 °C. Measurements were carried out by dilatometric method with DIL-402C unit manufactured by NETZSCH (Germany) with the error (1.5-2)×10-7 K-1. The approximation dependences of thermal coefficient of linear expansion on temperature have been obtained and reference tables have been calculated. The abnormal change of expansion coefficient above 550 °C is shown, and the explanation of the phenomenon is given.

Stankus, S. V.; Kozlovsky, Yu. M.; Yatsuk, O. S.; Verba, O. I.

2013-09-01

171

Extragalactic 2-10 keV source counts from a fluctuation analysis of deep BeppoSAX MECS images  

NASA Astrophysics Data System (ADS)

We present an analysis of the spatial fluctuations of the 2-10 keV Cosmic X-ray Background (CXB) as measured from 22 high galactic latitude (|b| > 25degr ) fields observed with the MECS instrument on-board BeppoSAX. This technique allowed us to probe extragalactic source counts a factor 3-4 fainter than is possible with direct measurements of pointlike sources in MECS deep fields. The slope of the 2-10 keV logN-logS relationship is found to be still close to the ``Euclidean'' one (gamma = 1.5) down to our flux limit of ~ 1.5*E-14 erg cm-2 s-1 , where the contribution of discrete sources to the 2-10 keV CXB amounts to ~ 40-50%. Source counts derived from the analysis presented in this letter are in very good agreement both with those directly measured with ASCA and BeppoSAX deep surveys at bright fluxes and with a first estimation of the 2-10 keV Chandra logN-logS at fainter fluxes.

Perri, M.; Giommi, P.

2000-10-01

172

CO2 laser ranging systems study  

Microsoft Academic Search

The conceptual design and error performance of a CO2 laser ranging system are analyzed. Ranging signal and subsystem processing alternatives are identified, and their comprehensive evaluation yields preferred candidate solutions which are analyzed to derive range and range rate error contributions. The performance results are presented in the form of extensive tables and figures which identify the ranging accuracy compromises

C. A. Filippi

1975-01-01

173

A comparison of the charge transfer and collisional activation processes in collisions between keV He + and CO 2  

Microsoft Academic Search

A commercial mass spectrometer coupled with a spectrograph and charge-coupled device (CCD) was used to obtain the collision-induced emission (CIE) spectra (190–1020nm) from 4 to 8keV collisions between projectile He+ ions and CO2 target gas (He+\\/CO2). The observed emissions were from the A2?u+ and B2?u+ states of CO2+, excited states of He, along with excited fragments. The relative vibrational population

Yawei Lin; Paul M. Mayer

2010-01-01

174

High-accuracy determination of the relative full energy peak efficiency curve of a coaxial HPGe detector in the energy range 700–1300 keV  

Microsoft Academic Search

A method for the high-accuracy determination of the relative full energy peak efficiency is established. Radionuclides that emit at least two gamma-ray lines for which the relative intensity can be found (from the decay scheme) to much better than ±0.1% were used as calibration standards. Specifically, the 889 and 1120 keV lines of 46Sc, the 983 and 1312 keV lines

Ayman Ibrahim Hawari; Ronald F. Fleming; Martin A. Ludington

1997-01-01

175

High-accuracy determination of the relative full energy peak efficiency curve of a coaxial HPGe detector in the energy range 700-1300 keV  

Microsoft Academic Search

A method for the high-accuracy determination of the relative full energy peak efficiency is established. Radionuclides that emit at least two gamma-ray lines for which the relative intensity can be found (from the decay scheme) to much better than +\\/-0.1% were used as calibration standards. Specifically, the 889 and 1120 keV lines of 46Sc, the 983 and 1312 keV lines

Ayman Ibrahim Hawari; Ronald F. Fleming; Martin A. Ludington

1997-01-01

176

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

177

Short and intermediate range order of Ge20Se80-xTex glasses  

NASA Astrophysics Data System (ADS)

The total structure factor, S(K), have been obtained for the chalcogenide Ge20Se80-xTex (where x=0, 10, 20, and 30 at. %) glasses using x-ray diffraction in the wave vector interval 0.28<=K<=6.87 A?-1. The appearance of the first sharp diffraction peak in the structure factor indicates the presence of the intermediate range order. The radii of the first- and second-coordination shells (r1,r2) are increased linearly with Te addition. The large covalent radius of Te atom in compare with that of Se atom was behind the above linear increase. The first coordination number shows insignificant changes with Te content. The obtained values of r1/r2 ratio and the corresponding bond angle (?) indicate that the structural units inside the present alloys are Ge(Se1/2)4 tetrahedra connected by chains of the chalcogen atoms. Raman spectra confirm the above conclusion and in the same time exclude the existence of Ge(Te1/2)4 tetrahedra. Based on the chemical ordered network mode, Te-Te bonds are responsible for the different behavior of Te-rich (30 at. %) glass from others.

Moharram, A. H.; Hefni, M. A.; Abdel-Baset, A. M.

2010-10-01

178

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

179

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 29-60 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.

Jonge, Martin D. de; Tran, Chanh Q.; Chantler, Christopher T.; Barnea, Zwi; Dhal, Bipin B.; Paterson, David; Kanter, Elliot P.; Southworth, Stephen H.; Young, Linda; Beno, Mark A.; Linton, Jennifer A.; Jennings, Guy [X-Ray Operations and Research, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); School of Physics, University of Melbourne, Victoria 3010 (Australia); Australian Synchrotron Project, Major Projects Victoria, 800 Blackburn Road, Clayton, Victoria 3168 (Australia); Chemistry Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); BESSRC-CAT, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States)

2007-03-15

180

30 keV to 2 MeV Boron implantation profiles in solids  

Microsoft Academic Search

Boron was implanted into several solids in the dose regime 10 to 10 ions\\/cm and at energies between some 10 keV and some MeV. Measurements of the corresponding depth distributions were performed by means of the B(n, ?0)Li(gnd) and B(n, ?1)Li*(1st) nuclear reaction techniques with thermal neutrons, and by SIMS. The results are compared to theoretical predictions.

D. Fink; L. Wang; J. P. Biersack; F. Jahnel

1990-01-01

181

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

182

Web 2.0 and Warfighter Training.  

National Technical Information Service (NTIS)

Web 2.0 services refer to web-based applications that allow a user to create and publish their own unique content. They also include services that allow mass collaboration among self-organized communities. Tim O'Reilly defines Web 2.0 as any set of tools ...

R. D. Smith

2008-01-01

183

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

184

Young Adult Literature 2.0  

ERIC Educational Resources Information Center

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

Hamilton, Buffy

2009-01-01

185

Energetic Particle Events (> or =30 keV) of Jovian origin observed by Voyager 1 and 2 in interplanetary space  

Microsoft Academic Search

Short-lived and long-lived ion flux increases (E> or =30 keV) of Jovian origin have been observed by the low energy charged particle (LECP) instrumnet on the Voyager 1 and 2 spacecraft. The short-lived events are observed more than 860 R\\/sub J\\/ upstream and more than 1500 R\\/sub J\\/ downstream of Jupiter. Observations of long-lived events appear to be confined to

R. D. Zwickl; S. M. Krimigis; J. F. Carbary; E. P. Keath; T. P. Armstrong; D. C. Hamilton; G. Gloeckler

1981-01-01

186

A Model for the Geostationary Electron Environment: POLE, From 30 keV to 5.2 MeV  

Microsoft Academic Search

In 2003, a model for the geostationary electron environment: POLE (Particle ONERA-LANL Environment) has been developed at ONERA\\/DESP. This model is based on the full complement of Los Alamos National Laboratory geostationary satellites, covers the period 1976-2001 and is valid from 30 keV up to 2.5 MeV and takes into account the solar cycle variation. Over the period 1976 to

A. Sicard Piet; S. Bourdarie; D. Boscher; R. H. W. Friedel

2006-01-01

187

CO2 laser ranging systems study  

NASA Technical Reports Server (NTRS)

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

Filippi, C. A.

1975-01-01

188

Carbon Capture (Carbon Cycle 2.0)  

ScienceCinema

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

2011-06-08

189

Electrical conduction processes in ZnO in a wide temperature range 20-500 K  

NASA Astrophysics Data System (ADS)

We have investigated the electrical conduction processes in as-grown and thermally cycled ZnO single crystal as well as as-grown ZnO polycrystalline films over the wide temperature range 20-500 K. In the case of ZnO single crystal between 110 and 500 K, two types of thermal activation conduction processes are observed. This is explained in terms of the existence of both shallow donors and intermediately deep donors that are consecutively excited to the conduction band as the temperature increases. By measuring the resistivity ?(T) of a given single crystal after repeated thermal cycling in vacuum, we demonstrate that oxygen vacancies play an important role in governing the shallow donor concentrations but leave the activation energy (~ 27+/-2 meV) largely intact. In the case of polycrystalline films, two types of thermal activation conduction processes are also observed between ~150 and 500 K. Below ~150 K, we found an additional conductionprocess due to the nearest-neighbor-hopping conduction mechanism, which takes place in the shallow impurity band. As the temperature further decreases below ~80 K, a crossover to the Mott variable-range-hopping conduction process is observed. Taken together with our previous measurements on ?(T) of ZnO polycrystalline films in the temperature range 2-100 K [Y. L. Huang et al., J. Appl. Phys. 107, 063715 (2010)], this work establishes a quite complete picture of the overall electrical conduction mechanisms in the ZnO material from liquid-helium temperatures up to 500 K.

Lien, Chien-Chi; Wu, Chih-Yuan; Li, Zhi-Qing; Lin, Juhn-Jong

2011-09-01

190

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

NASA Astrophysics Data System (ADS)

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

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

2014-04-01

191

30 CFR 20.2 - Definitions.  

Code of Federal Regulations, 2013 CFR

...AND APPROVAL OF MINING PRODUCTS ELECTRIC MINE LAMPS OTHER THAN STANDARD CAP LAMPS § 20.2 Definitions. (a) Adequate. ...organization, stating that upon investigation its lamp has been adjudged satisfactory under the...

2013-07-01

192

Web 2.0 and You!  

NSDL National Science Digital Library

Web 2.0 tools, when used in concert with solid constructivist teaching principles, have the potential to engage digital learners in their own education. These tools are more than resources; they are vital elements in meaningful instruction.

Dyck, Brenda A.

2010-08-01

193

Consumer Health Information Services 2.0  

Microsoft Academic Search

Web 2.0 functionality is changing the way consumers search for, evaluate, and use health information. What are some of the new “Consumer Health 2.0” sites and their features? How will this trend toward participatory information processing affect traditional sites such as the National Library of Medicine's MedlinePlus? How should librarians approach this new paradigm of health information-seeking? This article analyzes

Susan Mayer; Kay Hogan Smith; Gabriel Rios

2008-01-01

194

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

195

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

196

A Survey of Thermal (E < 30 keV) Electrons in the Near-Earth (XGSM > -20 RE) Magnetotail Observed by the PEACE instruments on the 4 Cluster Spacecraft.  

NASA Astrophysics Data System (ADS)

Between the beginning of July and the end of October 2001, the apogees of ESAs 4 spacecraft Cluster mission were located at radial distances of ~20 RE in the nightside magnetotail. The near-polar orbit means that the spacecraft cut from north-to-south through the tail region. At apogee, the spacecraft were in a configuration which is close to the nominal tetrahedral formation, with the inter-spacecraft separation of ~2000 km. In this paper, we present observations of electrons in energy range ~1 eV - 26 keV made by the Plasma Electron And Current Experiment (PEACE) on the 4 Cluster spacecraft as they pass through the magnetotail region. We survey the electron populations associated with the nightside magnetopause, the plasma mantle, the tail lobes, the plasma sheet and its boundary layers and the cross-tail current layer. We note the occurrence of high and low energy plasma sheet electron populations and the presence of a very diffuse but relatively energetic tailward-moving population within the tail lobe. We assess how the concurrent levels of geomagnetic activity affect these populations. With Cluster PEACE data, the 3-D configuration and evolution of these electron populations can also be determined for the first time.

Owen, C. J.; Dewhurst, J. P.; Fazakerley, A. N.

2002-05-01

197

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/

198

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

199

X-ray lithography fabrication of a zone plate for X-rays in the range from 15 to 30 keV  

Microsoft Academic Search

Progress on the fabrication of zone plates for hard X-rays is reported. The issue of achieving a high aspect ratio for lithographic structures has been addressed by developing a specific fabrication protocol based on the combined use of electron beam and proximity X-ray lithography. An example of a 1 mm diameter wide zone plate, optimized for a 23 keV X-ray

Matteo Altissimo; Filippo Romanato; Lisa Vaccari; Luca Businaro; Danut Cojoc; Burkhard Kaulich; Stefano Cabrini; Enzo Di Fabrizio

2002-01-01

200

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

Microsoft Academic Search

The effective atomic numbers and electron densities of the amino acids glycine, alanine, serine, valine, threonine, leucine, isoleucine, aspartic acid, lysine, glutamic acid, histidine, phenylalanine, arginine, tyrosine, tryptophane and the sugars arabinose, ribose, glucose, galactose, mannose, fructose, rhamnose, maltose, melibiose, melezitose and raffinose at the energies 30.8, 35.0, 81.0, 145, 276.4, 302.9, 356, 383.9, 661.6, 1173 and 1332.5keV were calculated

Shivalinge Gowda; S. Krishnaveni; Ramakrishna Gowda

2005-01-01

201

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

SciTech Connect

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

Jonge, Martin D. de; Tran, Chanh Q.; Chantler, Christopher T.; Barnea, Zwi; Dhal, Bipin B.; Cookson, David J.; Lee, Wah-Keat; Mashayekhi, Ali [School of Physics, University of Melbourne, Melbourne, Victoria 3010 (Australia); Chem-Mat-CARS, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States); XOR 1-ID, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 (United States)

2005-03-01

202

The solubility of light fullerenes in styrene over the temperature range 20 80°C  

NASA Astrophysics Data System (ADS)

The temperature dependence (over the range 20 80°C) of the solubility of light fullerenes (C60 and C70) and a mixture of fullerenes (60 wt % C60, 39 wt % C70, and 1 wt % C76 90) in styrene was studied. The corresponding solubility polytherms are given and characterized.

Semenov, K. N.; Charykov, N. A.; Arapov, O. V.; Trofimova, M. A.

2008-11-01

203

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/

204

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

205

Measurement of the thermal conductivities of 2-amino-2-methyl-1,3-propanediol (AMP), 2-amino-2-hydroxymethyl-1,3-propanediol (TRIS) and the mixture (AMP+TRIS, mole ratio 50:50) in the temperature range from 20°C to their supermelting temperatures  

Microsoft Academic Search

2-Amino-2-methyl-1,3-propanediol (AMP), 2-amino-2-hydroxymethyl-1,3-propanediol (TRIS) and the mixture (AMP+TRIS, mole ratio 50:50) are being considered as potential candidates for the thermal storage of energy. The thermal conductivities have been measured with an uncertainty of ±3% from 20°C to the supermelting points of these substances by means of a calorimeter equipped with a thermistor. The experimental thermal conductivities of the substances under

Zhi-Ying Zhang; Yu-Peng Xu

2001-01-01

206

20 CFR 903.2 - Definitions.  

Code of Federal Regulations, 2013 CFR

20 Employees' Benefits 4 2013-04-01 2013-04-01...Definitions. 903.2 Section 903.2 Employees' Benefits JOINT BOARD FOR THE ENROLLMENT...to the individual such as a finger or voice print or a photograph; (e) The...

2013-04-01

207

Web 2.0 and Pharmacy Education  

PubMed Central

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

Fox, Brent I.

2009-01-01

208

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

SciTech Connect

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

Imazono, T.; Koike, M.; Koeda, M.; Nagano, T.; Sasai, H.; Oue, Y.; Yonezawa, Z.; Kuramoto, S.; Terauchi, M.; Takahashi, H.; Handa, N.; Murano, T. [QuBS, Japan Atomic Energy Agency (JAEA), 8-1-7 Umemidai, Kizugawa, Kyoto 619-0215 (Japan); Device Dept., Shimadzu Corp., 1 Nishinokyo-Kuwabarcho, Nakagyo-ku, Kyoto 604-8511 (Japan); IMRAM, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); EC Business Unit, JEOL Ltd., 3-1-2 Musashino, Akishima, Tokyo 196-8558 (Japan)

2012-05-17

209

Reaction /sup 2/H(/sup 3/He,. gamma. ) /sup 5/Li at center-of-mass energies between 25 and 60 keV  

SciTech Connect

The gamma ray to proton branching ratio, GAMMA/sub ..gamma..//GAMMA/sub p/, of the /sup 2/H+ /sup 3/He reaction has been measured between center-of-mass energies of 25 and 60 keV. The ratio of the ground-state gamma reaction /sup 2/H(/sup 3/He,..gamma../sub 0/) /sup 5/Li to the dominant reaction /sup 2/H(/sup 3/He,p)/sup 4/He is observed to be roughly constant over this energy range with a best value of (4.5 +- 1.2) x 10/sup -5/. This ratio for the gamma-ray reaction to the /sup 5/Li first excited state is measured to have a value of (8 +- 3) x 10/sup -5/. The excitation energy of the first excited state is estimated to be 3.0 +- 1.0 MeV.

Cecil, F.E.; Cole, D.M.; Philbin, R.; Jarmie, N.; Brown, R.E.

1985-09-01

210

Efficient production of 100 keV deuterons in deuterium gas puff Z-pinches at 2 MA current  

NASA Astrophysics Data System (ADS)

Deuterium gas puff experiments were carried out on the S-300 Z-pinch at the Kurchatov Institute in Moscow. Gas puffs imploded onto the axis before a current peak at about 100 ns. Fusion neutrons were generated after the gas puff implosion during global expansion of a plasma column. Neutron emission lasted on average 35 ± 5 ns (full width half maximum, FWHM). In the downstream direction (on the Z-pinch axis behind the cathode), a mean neutron energy was 2.6 ± 0.1 MeV. Side-on neutron energy spectra peaked at 2.40 ± 0.05 MeV with about 600 ± 150 keV FWHM. A broad width of side-on neutron spectra implied a high radial component of deuteron velocities. An average kinetic energy of fast deuterons, which produced fusion neutrons, was 150 keV. A peak neutron yield reached a value of 6 × 1010 on a current level of 1.5 MA. It was by one order higher in comparison with other deuterated loads used on the same current generator. On the basis of experimental observations, we concluded that a total energy of deuterons accelerated to fusion energies was above 1.5 kJ. It is more than 15% of the energy input into a plasma. Therefore gas puff Z-pinches seem to be not only powerful sources of x-ray radiation but also efficient sources of 100 keV deuterons. Such a result is consistent with high neutron yields observed on the Angara Z-pinch and plasma foci with similar currents.

Klir, D.; Kravarik, J.; Kubes, P.; Rezac, K.; Cikhardt, J.; Litseva, E.; Hyhlik, T.; Ananev, S. S.; Bakshaev, Yu L.; Bryzgunov, V. A.; Chernenko, A. S.; Kalinin, Yu G.; Kazakov, E. D.; Korolev, V. D.; Ustroev, G. I.; Zelenin, A. A.; Juha, L.; Krasa, J.; Velyhan, A.; Vysin, L.; Sonsky, J.; Volobuev, I. V.

2010-06-01

211

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

Microsoft Academic Search

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

Pavel Dryak; Petr Kovar

2006-01-01

212

High-power 1 kHz laser-plasma x-ray source for ultrafast x-ray absorption near-edge spectroscopy in the keV range  

Microsoft Academic Search

A high average power broadband x-ray source is developed in the multi-keV range, based on the thermal emission of plasmas produced with a 1 kHz fs laser focused on high Z element target. This compact ultrafast x-ray source is used to measure the x-ray absorption near-edge spectroscopy of aluminum K-edge (1.559 keV) with noise lower than 1% of the absorption

F. Dorchies; M. Harmand; D. Descamps; C. Fourment; S. Hulin; S. Petit; O. Peyrusse; J. J. Santos

2008-01-01

213

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

214

Implantation-induced nonequilibrium reaction between Zn ions of 60 keV and SiO2 target  

NASA Astrophysics Data System (ADS)

Silica glass (SiO2) was implanted with 60 keV Zn+ ions to a fluence of 1.0×1017 ions/cm2, and the chemical states were investigated along the depth in as-implanted state by x-ray excited Auger electron spectroscopy and x-ray photoelectron spectroscopy. The metallic Zn and Zn2SiO4 phases were found to have, respectively, formed in the shallow and deep regions of the SiO2, whereas thermodynamics predicts the Zn phase only. Oxygen atoms in SiO2 are preferentially displaced to the deeper region because of the lighter mass. The excess oxygen in the deep region and athermal energy from the implantation drive the formation of Zn2SiO4.

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

2007-08-01

215

Science 2.0: Summer Surfing  

NSDL National Science Digital Library

What better way to spend a sunny summer day than surfing--the web, that is! With so many web 2.0 applications out there, it's hard to know what's really useful. In this month's column, the authors share some of their favorite free sites for educat

Brunsell, Eric; Horejsi, Martin

2010-07-01

216

Do Web 2.0 Right  

ERIC Educational Resources Information Center

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

Light, Daniel

2011-01-01

217

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.

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

2010-01-01

218

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

219

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

220

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

221

Change Management Meets Web 2.0  

ERIC Educational Resources Information Center

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

Gale, Doug

2008-01-01

222

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

223

BioSense 2.0  

PubMed Central

Objective To familiarize public health practitioners with the BioSense 2.0 application and its use in all hazard surveillance. Introduction BioSense 2.0 protects the health of the American people by providing timely insight into the health of communities, regions, and the nation by offering a variety of features to improve data collection, standardization, storage, analysis, and collaboration. BioSense 2.0 is the result of a partnership between the Centers for Disease Control and Prevention (CDC) and the public health community to track the health and well-being of communities across the country. In 2010, the BioSense Program began a redesign effort to improve features such as centralized data mining and addressing concerns that the system could not meet its original objective to provide early warning or detect local outbreaks. Methods Using the latest technology, BioSense 2.0 integrates current health data shared by health departments from a variety of sources to provide insight on the health of communities and the country. By getting more information faster, local, state, and federal public health partners can detect and respond to more outbreaks and health events more quickly. From flu outbreaks to car accidents, BioSense 2.0 provides the critical data, information, and tools that public health officials need to better understand and address health problems at the local, state, regional, and national levels. Also, by knowing what is happening across local borders, public health professionals can anticipate potential health problems and respond effectively to protect the health of all people. The demonstration will include a basic overview of the BioSense 2.0 application and the functionality available to public health departments and their data providers. The presenter will also show an example of how BioSense 2.0 can be used in a real-world public health example. Conclusions Over the past two years much has been accomplished during the redesign effort. BioSense 2.0 was launched in November of 2011 and the collaboration between the BioSense program and the public health community has yielded an application based on a user-centered design approach and built on a platform that allows for flexible data sharing across jurisdictions and with partners. The public health community has played a critical role in designing and improving the BioSense 2.0 application and through continued collaboration the system will continue to improve. Innovative features of the BioSense 2.0 application include the use of cloud technology, a novel and flexible data sharing feature, a community driven approach, enhanced algorithms, and no cost statistical analysis tools available in the cloud. Each of these features will be discussed during the presentation.

Chester, Kelley G.

2013-01-01

224

Photon emission from 511 keV gamma rays incident on BaF 2 and LaF 3:Nd 3+ crystals using a cesium iodide photocathode detector  

Microsoft Academic Search

We have studied the possibility of using BaF2 and LaF3 doped with Nd3+, concentrations ranging from 0.1 to 15 mol% as efficient converters of 511 keV gamma rays. We have measured the number of photoelectrons\\/MeV for both crystals using a parallel-plate avalanche chamber operating with a CsI photocathode. The photocathode is sensitive to wavelengths in the range 160–220 nm. The

W. Kononenko; J. G Heinrich; N. S Lockyer; J. M Miller; C. Woody; S. Kwan

1997-01-01

225

Study of BaF2 with 511 KeV Gamma Rays  

Microsoft Academic Search

Results will be presented on tests conducted with a 20 Torr ethane 1000 Angstrom cesium-iodide photocathode avalanche chamber [1], with a barium-fluoride scintillator window. Positrons are emitted from a sodium-22 source, which annihilate to produce two 0.511 MeV gamma rays. The barium-fluoride scintillator window converts the 0.511 MeV gamma rays into ultraviolet wavelength photons, which are absorbed in the cesium-iodide

Jon Miller

1996-01-01

226

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

SciTech Connect

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

Jimenez-Rey, D.; Zurro, B.; McCarthy, K. J.; Baciero, A. [Laboratorio Nacional de Fusion por Confinamiento Magnetico, Asociacion Euratom-CIEMAT, Av. Complutense 22, E-28040, Madrid (Spain); Garcia, G. [Instituto de Matematicas y Fisica Fundamental, Consejo Superior de Investigaciones Cientificas, Serrano 113-bis, 20806, Madrid (Spain)

2008-10-15

227

The response of a radiation resistant ceramic scintillator (Al2O3:Cr) to low energy ions (0-60 keV).  

PubMed

This work extends a previous study on ionoluminescence of a radiation-hard ceramic scintillator, Al(2)O(3):Cr, to ions accelerated to keV energies [K. J. McCarthy et al., J. Nucl. Mater. 321, 78 (2003)]. It is motivated by the identification of this material as a promising candidate for use in the fast-ion-loss detector for ITER [for the range of thermal (low energy) and suprathermal ions]. In the paper we quantify and compare its ionoluminescence with that of some common luminescent materials (YAG:Ce and ruby) when irradiated by H(+) ions accelerated to < or = 60 keV using a purpose built laboratory setup. Next, studies are made on the ceramic to quantify its response as a function of incident ion mass, i.e., to He(+). For this, the absolute luminosities of the material are estimated in terms of the number of photons emitted per incident ion as a function of energy. Moreover, the radiation hardness and postirradiation recovery of the ceramic are investigated. Finally, from the studies it can be concluded that the ceramic ruby is a good candidate for detecting low energy ions as long as its temporal response (approximately several milliseconds) is not a constraint for specific ion measurements. PMID:19044498

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

2008-10-01

228

The log N-log S relationship from the BeppoSAX 2-10 keV survey  

NASA Astrophysics Data System (ADS)

The results of a 2 - 10 keV BeppoSAX X-ray survey based on 140 high galactic latitude MECS fields are presented. About 25% of the Cosmic X-ray Background (CXB) is resolved into discrete sources at the sensitivity limit of the survey (S ~ 5×10-14 erg cm-2 s-1). The log N-log S relationship, built with the 177 X-ray sources of the survey, is steep and in good agreement with that derived from ASCA surveys. The results of a CXB fluctuation analysis, which probes the log N-log S down to about 1×10-14 erg cm-2 s-1, are also presented.

Perri, M.; Giommi, P.; Fiore, F.

229

Inferentie en Besturing in Next 2.0 (Inference and Control in Next 2.0).  

National Technical Information Service (NTIS)

The publication will discuss the inference and control mechanisms of NLR Engineering X-pert system Toolkit (NEXT 2.0). NEXT 2.0 contains a hybrid knowledge representation of frames, production rules and tasks, and an inference and control mechanism based ...

P. J. Kat

1988-01-01

230

A comparison of the charge transfer and collisional activation processes in collisions between keV He + and CO 2  

NASA Astrophysics Data System (ADS)

A commercial mass spectrometer coupled with a spectrograph and charge-coupled device (CCD) was used to obtain the collision-induced emission (CIE) spectra (190-1020 nm) from 4 to 8 keV collisions between projectile He + rad ions and CO 2 target gas (He + rad /CO 2). The observed emissions were from the A2?u+ and B2?u+ states of CO2+rad , excited states of He, along with excited fragments. The relative vibrational population of the A2?u+ state were estimated and compared with our previous CO2+rad /He studies. The results indicate that charge transfer ionization of CO 2 in He + rad /CO 2 collisions is similar to that of photoexcitation, while in the case of CO2+rad /He, the population is more evenly distributed due to intramolecular vibrational redistribution (IVR) after the collision. Adiabatic potential energy surfaces calculated at the CISD/6-311+g(2df) level of theory for CO2+rad /He collisions, show the curve crossing of the CO2+rad A2?u+ and CO2+rad B2?u+ states, in agreement with our observation.

Lin, Yawei; Mayer, Paul M.

2010-12-01

231

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

232

Determination of optical constants of scandium films in the 20-1000 eV range.  

PubMed

The transmittance of thin films of Sc deposited by evaporation in ultrahigh vacuum conditions has been investigated in the 20-1000 eV spectral range. Transmittance measurements were performed in situ on Sc layers that were deposited over grids coated with a C support film. Transmittance measurements were used to obtain the extinction coefficient of Sc films at each individual photon energy investigated. These data, along with the data available in the literature for the rest of the spectrum, were used to obtain the refractive index of Sc by means of the Kramers-Krönig analysis. Sum-rule tests indicated an acceptable consistency of the data. PMID:17047716

Fernández-Perea, Mónica; Larruquert, Juan I; Aznárez, José A; Méndez, José A; Poletto, Luca; Malvezzi, A Marco; Giglia, Angelo; Nannarone, Stefano

2006-11-01

233

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

PubMed Central

Background The term Web 2.0 became popular following the O’Reilly Media Web 2.0 conference in 2004; however, there are difficulties in its application to health and medicine. Principally, the definition published by O’Reilly is criticized for being too amorphous, where other authors claim that Web 2.0 does not really exist. Despite this skepticism, the online community using Web 2.0 tools for health continues to grow, and the term Medicine 2.0 has entered popular nomenclature. Objective This paper aims to establish a clear definition for Medicine 2.0 and delineate literature that is specific to the field. In addition, we propose a framework for categorizing the existing Medicine 2.0 literature and identify key research themes, underdeveloped research areas, as well as the underlying tensions or controversies in Medicine 2.0’s diverse interest groups. Methods In the first phase, we employ a thematic analysis of online definitions, that is, the most important linked papers, websites, or blogs in the Medicine 2.0 community itself. In a second phase, this definition is then applied across a series of academic papers to review Medicine 2.0’s core literature base, delineating it from a wider concept of eHealth. Results The terms Medicine 2.0 and Health 2.0 were found to be very similar and subsume five major salient themes: (1) the participants involved (doctors, patients, etc); (2) its impact on both traditional and collaborative practices in medicine; (3) its ability to provide personalized health care; (4) its ability to promote ongoing medical education; and (5) its associated method- and tool-related issues, such as potential inaccuracy in enduser-generated content. In comparing definitions of Medicine 2.0 to eHealth, key distinctions are made by the collaborative nature of Medicine 2.0 and its emphasis on personalized health care. However, other elements such as health or medical education remain common for both categories. In addition, this emphasis on personalized health care is not a salient theme within the academic literature. Of 2405 papers originally identified as potentially relevant, we found 56 articles that were exclusively focused on Medicine 2.0 as opposed to wider eHealth discussions. Four major tensions or debates between stakeholders were found in this literature, including (1) the lack of clear Medicine 2.0 definitions, (2) tension due to the loss of control over information as perceived by doctors, (3) the safety issues of inaccurate information, and (4) ownership and privacy issues with the growing body of information created by Medicine 2.0. Conclusion This paper is distinguished from previous reviews in that earlier studies mainly introduced specific Medicine 2.0 tools. In addressing the field’s definition via empirical online data, it establishes a literature base and delineates key topics for future research into Medicine 2.0, distinct to that of eHealth.

Joshi, Indra; Wareham, Jonathan

2008-01-01

234

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

ScienceCinema

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/

235

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

236

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

ScienceCinema

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

2010-09-01

237

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

238

Measurements of L X-ray fluorescence cross sections for rare earths at 15.2 keV  

NASA Astrophysics Data System (ADS)

L X-ray fluorescence cross sections for elements with 64? Z?70 at 15.2 keV have been measured using an X-ray tube, a secondary fluorescent target of Y and a germanium detector. Experimental results obtained were grouped considering the transitions scheme and the energy values between level and sublevel, and the detector's resolution. The present experimental setup showed very good performance in discriminating the fluorescence emission lines and in reducing the signal-to-background ratio. The results obtained were compared with theoretical values calculated using two different data tables. Better agreement was found between our experimental values and the theoretical data calculated using Puri's data tables.

Bonzi, Edgardo V.; Barrea, Rau'ul A.

2002-02-01

239

W3C: XHTML 2.0  

NSDL National Science Digital Library

Web developers will be especially interested in this sneak peek at the next incarnation of the Extensible HyperText Markup Language (XHTML). This is the seventh working draft of the XHTML 2.0 specification produced by the World Wide Web Consortium, an organization that creates standards that maintain interoperability. As can be seen from the list of issues, many unresolved points remain in the specification. However, the progress that has already been made is well documented and shows how the language is evolving.

2005-01-01

240

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

241

High-efficiency B?C/Mo?C alternate multilayer grating for monochromators in the photon energy range from 0.7 to 3.4 keV.  

PubMed

An alternate multilayer (AML) grating has been prepared by coating an ion etched lamellar grating with a B4C/Mo2C multilayer (ML) having a layer thickness close to the groove depth. Such a structure behaves as a 2D synthetic crystal and can reach very high efficiencies when the Bragg condition is satisfied. This AML coated grating has been characterized at the SOLEIL Metrology and Tests Beamline between 0.7 and 1.7 keV and at the four-crystal monochromator beamline of Physikalisch-Technische Bundesanstalt (PTB) at BESSY II between 1.75 and 3.4 keV. A peak diffraction efficiency of nearly 27% was measured at 2.2 keV. The measured efficiencies are well reproduced by numerical simulations made with the electromagnetic propagation code CARPEM. Such AML gratings, paired with a matched ML mirror, constitute efficient monochromators for intermediate energy photons. They will extend the accessible energy for many applications as x-ray absorption spectroscopy or x-ray magnetic circular dichroism experiments. PMID:24686695

Choueikani, Fadi; Lagarde, Bruno; Delmotte, Franck; Krumrey, Michael; Bridou, Françoise; Thomasset, Muriel; Meltchakov, Evgueni; Polack, François

2014-04-01

242

3-10 KeV and 0.1- to 2-MeV Observations of Four gamma-Ray Bursts.  

National Technical Information Service (NTIS)

Four catalogued gamma -ray bursts that occurred between 79/3/7 and 79/7/31 have been observed over the 3 to 10 keV range by a joint NRL/Los Alamos experiment on the Air Force P78-1 satellite. The bursts were also well observed by members of the interplane...

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

1983-01-01

243

Sapphire-fiber thermometer ranging from 20 to 1800 degrees C.  

PubMed

A novel, to our knowledge, sapphire-fiber thermometer ranging from 20 degrees to 1800 degrees C is presented that combines the radiance detection and the fluorescent lifetime detection schemes into one system. The thermal probe is a sapphire fiber grown from the laser-heated pedestal growth method. Its end part is doped with Cr(3+) ion and coated with some radiance material to constitute a minifiber cavity. The sapphire fiber is coupled with a Y-shaped silica fiber bundle for signal transmission. Radiance and fluorescence signal processing schemes are also set up within one thermometer system. A sandwich two-band p-i-n detector is used that may respond to both the radiation and the fluorescence. Preliminary experimental results show that the thermometer is suitable for practical application with potential long-term stability and a high-temperature resolution. PMID:18305723

Shen, Y; Tong, L; Wang, Y; Ye, L

1999-03-01

244

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

245

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

SciTech Connect

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

Belli, P. [INFN, Sezione di Roma Tor Vergata, I-00133 Rome (Italy); Bernabei, R. [INFN, Sezione di Roma Tor Vergata, I-00133 Rome (Italy); Dipartimento di Fisica, Universita di Roma Tor Vergata, I-00133 Rome (Italy); Cappella, F. [INFN, Sezione di Roma La Sapienza, I-00185 Rome (Italy); Dipartimento di Fisica, Universita di Roma La Sapienza, I-00185 Rome (Italy); Cerulli, R.; Laubenstein, M.; Nisi, S. [INFN, Laboratori Nazionali del Gran Sasso, 67010 Assergi (AQ) (Italy); Danevich, F. A.; Nagorny, S. S.; Polischuk, O. G.; Tretyak, V. I. [Institute for Nuclear Research, MSP 03680 Kyiv (Ukraine); Incicchitti, A. [INFN, Sezione di Roma La Sapienza, I-00185 Rome (Italy)

2011-03-15

246

GoBox 2.0  

NSDL National Science Digital Library

This application, produced by GoBox Software, allows users to access numerous search engines, find home and business phone numbers, and get stock quotes quickly. Essentially, the application is a small box that resides on the computer screen from which users can type in their search terms, along with selecting which particular search engine they would like to use. Additionally, GoBox checks to make sure users are online and allows for fully customizable searches. Perhaps the best thing about GoBox is the fact that it takes up a relatively small amount of screen space. GoBox 2.0 is fully compatible with the Windows 98, Me, NT, 2000, and XP operating systems.

247

Movable Type Version 2.0  

NSDL National Science Digital Library

Movable Type has recently released version 2.0 (an upgrade from 1.4). Movable Type is a Web-based personal publishing system designed to ease the maintenance of regularly updated news or journal sites. Most importantly, this product runs on your own Web server, allowing complete control over your sites. Some of its many features include allowing the importation of entries and comments from other content management systems (Blogger, GreyMatter, NewsPro); enabling one-click publishing to multiple destinations and formats; permitting visitors to post comments on entries and engage in conversations with its built-in comment system; allowing selective exclusion of commenting on certain posts; and much more. This product is free for personal or non-profit use; however, there is a fee for commercial or for-profit sites.

2001-01-01

248

BSD Portals for LINUX 2.0  

NASA Technical Reports Server (NTRS)

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

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

1999-01-01

249

Electron capture cross-sections between 3He + ion and rubidium vapor in the energy range 1.0–19 keV  

Microsoft Academic Search

Electron capture cross-sections have been measured for 3He+ ions in Rb vapor. The deduced data were used for evaluating the performance of the proposed polarized 3He ion source (SEPIS) based on the spin-exchange collisions. Measurements of the 3He+ beam components after passing through the target were made as a function of the Rb target thickness at energies ranging from 1.0

M. Tanaka; Y. Takahashi; T. Shimoda; T. Furukawa; M. Yosoi; K. Takahisa; N. Shimakura; S. Yasui

2006-01-01

250

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

ScienceCinema

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/

251

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

ScienceCinema

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

2011-06-08

252

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

ScienceCinema

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

2011-06-08

253

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

NASA Astrophysics Data System (ADS)

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

Kyrala, George A.

2006-05-01

254

Sputtering and Molecular Synthesis Induced by 100 keV Protons in Condensed CO2 and Relevance to the Outer Solar System  

NASA Astrophysics Data System (ADS)

We present results on sputtering and radiation chemistry of CO2 films induced by 100 keV H+ at 25 and 50 K. Using a quartz crystal microbalance, we measure a sputtering yield (SY) between ~10 and 20 CO2 equivalent per ion at 25 K. The yield at 50 K is similar to that at 25 K at low fluences, but increases to ~2400 by mid-1014 H+ cm-2 and declines at higher fluence. Irradiation to 1 × 1015 H+ cm-2 depletes ~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 O2, O, and CO2. Using infrared spectroscopy, we monitor the depletion of CO2 and the accumulation of CO and O2 and minor species as O3 and CO3. We determine G(-CO2) = 2.6 ± 0.3, the number of CO2 destroyed per 100 eV at 25 K. A significant fraction of the radiolyzed CO and O2 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 O2 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 CO2 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 CO2 is thermally released from an endogenic source.

Raut, U.; Baragiola, R. A.

2013-07-01

255

Multielectronic close-coupling treatment of atomic and molecular collisions: applications to H+-Li collisions in the keV energy range  

NASA Astrophysics Data System (ADS)

We present a new approach to describe electronic processes occurring in ion-atom and ion-molecule collisions at impact energies ranging from 50 eV.u?1 to 1 MeV.u?1. The treatment is based on the semiclassical approximation in which the time-dependent Schrödinger equation is solved non perturbatively, taking into account all the electrons of the collision system. This allows to describe exactly multielectronic processes and also, at the same footing, processes involving valence and inner shell electrons. We apply this model to describe electron transfer in a genuine three-electron system, H+-Li.

Labaigt, Gabriel; Dubois, Alain

2014-04-01

256

50 CFR 30.2 - Disposition of surplus range animals.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Disposition of surplus range animals. 30.2 Section 30.2 Wildlife and Fisheries...NATIONAL WILDLIFE REFUGE SYSTEM RANGE AND FERAL ANIMAL MANAGEMENT Range Animals § 30.2 Disposition of surplus range...

2013-10-01

257

Comparison of the gamma-ray spectra from 2. 8keV neutron capture and thermal-neutron capture in sodium-23  

Microsoft Academic Search

The gamma-ray spectrum resulting from neutron capture in the 2.8-keV resonance of ²³Na has been measured with the high-resolution annihilation pair spectrometer at the internal-target facility of the CP-5 reactor. The 2.8-keV resonance was populated by using the boron-shielded target technique: A ¹\\/â-in.-thick filter of ¹°B surrounding the sodium sample selectively removes low-energy neutrons from the spectrum; the 1\\/E dependence

W. M. Wilson; H. E. Jackson; G. E. Thomas

1977-01-01

258

ViennaRNA Package 2.0  

PubMed Central

Background Secondary structure forms an important intermediate level of description of nucleic acids that encapsulates the dominating part of the folding energy, is often well conserved in evolution, and is routinely used as a basis to explain experimental findings. Based on carefully measured thermodynamic parameters, exact dynamic programming algorithms can be used to compute ground states, base pairing probabilities, as well as thermodynamic properties. Results The ViennaRNA Package has been a widely used compilation of RNA secondary structure related computer programs for nearly two decades. Major changes in the structure of the standard energy model, the Turner 2004 parameters, the pervasive use of multi-core CPUs, and an increasing number of algorithmic variants prompted a major technical overhaul of both the underlying RNAlib and the interactive user programs. New features include an expanded repertoire of tools to assess RNA-RNA interactions and restricted ensembles of structures, additional output information such as centroid structures and maximum expected accuracy structures derived from base pairing probabilities, or z-scores for locally stable secondary structures, and support for input in fasta format. Updates were implemented without compromising the computational efficiency of the core algorithms and ensuring compatibility with earlier versions. Conclusions The ViennaRNA Package 2.0, supporting concurrent computations via OpenMP, can be downloaded from http://www.tbi.univie.ac.at/RNA.

2011-01-01

259

A study of inclusive photoproduction of hyperons and antihyperons in the range of 20 to 70 GeV  

Microsoft Academic Search

Results are presented on inclusive photoproduction in hydrogen of Sigma0, Sigma1385+\\/-, Xi-0, and their antiparticles for incident energies between 20 and 70 GeV. Hyperons and antihyperons are mainly measured in the kinematical range of central and forward production (xF > -0.3). We find the cross-section ratios sigma(Sigma1385+)\\/sigma(Sigma1385-) = 1.4 +\\/- 0.1, sigma(Sigma1385+)\\/sigma(Sigma1385-) = 1.3 +\\/- 0.2 and an antiparticle\\/particle ratio

D. Aston; M. Atkinson; R. Bailey; A. K. Ball; H. J. Bautsch; B. Bouquet; G. R. Brookes; J. Bröring; Peter J Bussey; D. Clarke; A. B. Clegg; B. D'Almagne; G. de Rosny; B. Diekmann; Alexander Donnachie; M. Draper; B. Drevillon; I. P. Duerdoth; J.-P. Dufey; R. J. Ellison; D. Ezra; P. Feller; A. Ferrer; P. J. Flynn; William Galbraith; R. George; S. D. M. Gill; M. Goldberg; S. Goodman; W. Graves; B. Grossetête; P. G. Hampson; K. Heinloth; R. E. Hughes-Jones; J. S. Hutton; M. Ibbotson; M. Jung; S. Katsanevas; M. A. R. Kemp; F. Kovacs; B. R. Kumar; G. D. Lafferty; J.-M. Lévy; V. Liebenau; John Litt; G W London; D. Mercer; J. V. Morris; K. Müller; D. Newton; E. Paul; P. Petroff; Y. Pons; C. Raine; F. Richard; R H Richter; J. H. C. Roberts; Patrick Roudeau; A. Rougé; M. Rumpf; M. Sené; Ian O Skillicorn; J. C. Sleeman; K. M. Smith; C. Steinhauer; Kenneth Mick Storr; R. J. Thompson; D. Treille; Ch. de La Vaissière; H L Videau; I. Videau; A. P. Waite; A. Wijangco; W. Wojcik; J.-P. Wuthrick; T. P. Yiou

1982-01-01

260

Energy loss, range, and bremsstrahlung yield for 10-keV to 100-MeV electrons in various elements and chemical compounds  

NASA Astrophysics Data System (ADS)

Even though the United States lacks a national climate policy, significant action has occurred at the local and regional levels. Some of the most aggressive climate change policies have occurred at the state and local levels and in interagency cooperation on specific management issues. While there is a long history of partnerships in dealing with a wide variety of policy issues, the uncertainty and the political debate surrounding climate change has generated new challenges to establishing effective policy networks. This paper investigates the formation of climate policy networks in the State of Nevada. It presents a methodology based on social network analysis for assessing the structure and function of local policy networks across a range of substantive climate impacted resources (water, landscape management, conservation, forestry and others). It draws from an emerging literature on federalism and climate policy, public sector innovation, and institutional analysis in socio-ecological systems. Comparisons across different policy issue networks in the state are used to highlight the influence of network structure, connectivity, bridging across vertical and horizontal organizational units, organizational diversity, and flows between organizational nodes.

Pages, Lucien; Bertel, Evelyne; Joffre, Henri; Sklavenitis, Laodamas

2012-12-01

261

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

262

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

National Technical Information Service (NTIS)

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) i...

A. Courcelle H. Derrien L. C. Leal N. M. Larson

2005-01-01

263

Oh! Web 2.0, Virtual Reference Service 2.0, Tools & Techniques (II)  

ERIC Educational Resources Information Center

The paper describes the theory and definition of the practice of librarianship, specifically addressing how Web 2.0 technologies (tools) such as synchronous messaging, collaborative reference service and streaming media, blogs, wikis, social networks, social bookmarking tools, tagging, RSS feeds, and mashups might intimate changes and how…

Arya, Harsh Bardhan; Mishra, J. K.

2012-01-01

264

NATIONAL WATER POLLUTION CONTROL ASSESSMENT MODEL, VERSION 2.0 (NWPCAM 2.0)  

EPA Science Inventory

NWPCAM 2.0 is a national-level water quality modeling system that can be used to simulate the water quality changes and economic benefits that result from various pollution control policies. It builds and significantly improves on an earlier model the Clean Water Act Effects Mode...

265

Extended observations of higher than 7-keV X-rays from Centaurus X-3 by the OSO-7 satellite  

NASA Technical Reports Server (NTRS)

The UCSD X-ray telescope on board OSO-7 provided 43 days of continuous coverage of the variable X-ray source Cen X-3 at energies above 7 keV during December 1971 and January 1972. We detected the 4.8-sec pulsation period, the 2.087-day eclipse cycle, and an apparently nonperiodic, low-intensity state lasting more than 12 days. Spectra obtained over the 7-30 keV range during noneclipsed high-intensity states are steeper than those previously reported. Large changes, which may be characterized by a number spectral index alpha varying between 3.0 plus or minus 0.2 and 2.0 plus or minus 0.3, or by exponential spectra with kT varying from 6 plus or minus 2 to 13 plus or minus 3 keV, occur at different high-intensity states.

Baity, W. A.; Ulmer, M. P.; Wheaton, W. A.; Peterson, L. E.

1974-01-01

266

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

267

Total, Partial, and Electron-Capture Cross Sections for Ionization of Water Vapor by 20-150 keV Protons  

Microsoft Academic Search

We present experimental results for proton ionization of water molecules based on a novel event by event analysis of the different ions produced (and lost). We are able to obtain mass analyzed product ion signals (e.g., H2O+, OH+, O+, O++, H+) in coincidence with the projectile analyzed after the collision, i.e., either being H+, neutral H after single electron capture

F. Gobet; B. Farizon; M. Farizon; M. J. Gaillard; M. Carré; M. Lezius; P. Scheier; T. D. Märk

2001-01-01

268

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

269

Reevaluation of ENDL of sigma(n,f) and anti nu/sub p/ for /sup 235/U and /sup 239/Pu from 100 keV to 20 MeV  

SciTech Connect

Reevaluations of the neutron-induced fission cross sections from 100 keV to 20 MeV and anti nu/sub p/(E) from 0 to 20 MeV for /sup 235/U and /sup 239/Pu have been completed and entered into the Livermore Evaluated Nuclear Data Library (ENDL). For /sup 235/U(n,f) the recent evaluation of W.P. Poenitz of Argonne National Laboratory has been adopted as the /sup 235/U(n,f) ENDL standard. For /sup 239/Pu(n,f) the /sup 239/Pu//sup 235/U fission cross section ratio measurement of Carlson and Behrens of LLNL, which has served as the basis for the /sup 239/Pu(n,f) ENDL evaluation to the present, is compared with several new ratio measurements for the new evaluation. For anti nu/sub p/(E) ratio values of Soleihac, et al. were renormalized to the currently accepted value of /sup 252/Cf anti nu/sub sf/ and used as the basis for the present ENDL evaluation. Experimental anti nu/sub p/(E) values measured by Gwin, et al. in 1978 from 0.5 keV to 10 MeV are reasonably consistent with the values of Soleihac, et al. Results of criticality calculations using the new evaluated cross sections and anti nu/sub p/(E) are compared for various critical mass assemblies. Also, Monte Carlo calculations using these new evaluations are compared with experimental data from the LLNL 14-MeV pulsed sphere measurements.

Howerton, R.J.; White, R.M.

1984-01-01

270

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

271

Production of Positive Ions and Electrons in Collisions of 1-25 KeV Protons and Hydrogen Atoms with Co, CO2, CH4, and NH3.  

National Technical Information Service (NTIS)

Cross sections are reported for the production of slow, positive-ions (sigma(+)) and electrons (sigma(-)) in collisions of 1-25 keV protons and hydrogen atoms with CO, CO2, CH4, and NH3. For H(+) bombardment sigma(-) is the total ionization cross section,...

R. J. McNeal

1970-01-01

272

A System for Measurements on Radio Frequency Discharges in the Frequency Range of 20 TO 80 Mhz.  

National Technical Information Service (NTIS)

A system for measuring the basic electrical properties of radio frequency gas discharges is described. The system provides the capability for investigating discharges in air at atmospheric pressure in the frequency range of 20 to 80 MHz. The discharges ar...

E. L. Price

1968-01-01

273

Power Supply for the Lbl 40 Kev Neutral Beam Source.  

National Technical Information Service (NTIS)

A 20 keV, 50 Amp, 10 millisec pulse D exp 0 Neutral Beam Source at the Lawrence Berkeley Laboratory that serves as the prototype for 12 similar sources now in operation on the 2XIIB Mirror Machine at the Lawrence Livermore Laboratory has been recently upg...

W. R. Baker M. L. Fitzgerald V. J. Honey

1975-01-01

274

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

PubMed

Because of overpopulation of African elephants in South Africa and the consequent threat to biodiversity, the need for a method of population control has become evident. In this regard, the potential use of the porcine zona pellucida (pZP) vaccine as an effective means for population control is explored. While potential effects of pZP treatment on social behavior of African elephants have been investigated, no examination of the influence of pZP vaccination on the endocrine correlates in treated females has been undertaken. In this study, ovarian activity of free-ranging, pZP-treated African elephant females was monitored noninvasively for 1 yr at Thornybush Private Nature Reserve, South Africa, by measuring fecal 5?-pregnan-3?-ol-20-on concentrations via enzyme immunoassay. A total of 719 fecal samples from 19 individuals were collected over the study period, averaging 38 samples collected per individual (minimum, maximum: 16, 52). Simultaneously, behavioral observations were made to record the occurrence of estrous behavior for comparison. Each elephant under study showed 5?-pregnan-3?-ol-20-on concentrations rising above baseline at some period during the study indicating luteal activity. Average 5?-pregnan-3?-ol-20-on concentrations were 1.61 ± 0.46 ?g/g (mean ± SD). Within sampled females, 42.9% exhibited estrous cycles within the range reported for captive African elephants, 14.3% had irregular cycles, and 42.9% did not appear to be cycling. Average estrous cycle duration was 14.72 ± 0.85 wk. Estrous behavior coincided with the onset of the luteal phase and a subsequent rise in 5?-pregnan-3?-ol-20-on concentrations. Average 5?-pregnan-3?-ol-20-on levels positively correlated with rainfall. No association between average individual 5?-pregnan-3?-ol-20-on concentrations or cyclicity status with age or parity were detected. Earlier determination of efficacy was established via fecal hormone analysis with no pregnancies determined 22 mo post-treatment and onward. Results indicate the presence of ovarian activity amongst pZP-treated female African elephants in 2 yr after initial immunization. Further study should now be aimed toward investigating the long-term effects of pZP vaccination on the reproductive function of female African elephants. PMID:22444560

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

2012-07-01

275

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

276

Design of the Experimental Apparatus to Obtain a Thermal Neutron Beam, Intermediate-Energy Neutrons (2-144 KeV) and High-Energy Photons (6 MeV) by Means of the Triga Reactor at the ENEA Casaccia Center.  

National Technical Information Service (NTIS)

Neutron beams in the energy range between 2 and 150 KeV can be obtained by suitably filtering the neutrons in the beam tubes of a nuclear research reactor. This method has been applied at the NBS and PTB reactors. Neutron beams in this energy range are ve...

R. F. Laitano C. Mancini

1987-01-01

277

20-A to 100-A AC-DC Coaxial Current Shunts for 100 kHz Frequency Range  

Microsoft Academic Search

The paper describes a set of four cylindrical, coaxial, ac current shunts used as the new National Research Council (NRC) working standards in the frequency range up to 100 kHz. They were designed for currents from 20 A to 100 A. At the lower current range the shunts were compared to NRC coaxial shunts built from discrete resistors. At the

P. S. Filipski; M. Boecker; M. Garcocz

2007-01-01

278

20-A to 100-A AC-DC Coaxial Current Shunts for 100kHz Frequency Range  

Microsoft Academic Search

The paper describes a set of four cylindrical coaxial ac current shunts used as the new National Research Council of Canada (NRC) working standards in the frequency range up to 100 kHz. They were designed for currents from 20 to 100 A. At the lower current range, the shunts were compared to NRC coaxial shunts built from discrete resistors. At

Piotr S. Filipski; Michael Boecker; Martin Garcocz

2008-01-01

279

SHOCK 2.0 Theory Manual.  

National Technical Information Service (NTIS)

SHOCK is a computer program that implements the method used to generate Figures 2-52 through 2-100 for averaged reflected pressure and Figures 2- 101 through 2-149 for reflected impulse in UFC 3-340-02 Structures to Resist the Effects of Accidental Explos...

C. Stewart J. Abraham

2011-01-01

280

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

PubMed

Systematic calculations of the stopping powers (SP) and inelastic mean free paths (IMFP) for 20-20,000eV electrons in a group of 10 important scintillators have been carried out. The calculations are based on the dielectric model including the Born-Ochkur exchange correction and the optical energy loss functions (OELFs) are empirically evaluated because of the lack of available experimental optical data for the scintillators under consideration. The evaluated OELFs are examined by both the f-sum rule and the calculation of mean ionization potential. The SP and IMFP data presented here are the first results for the 10 scintillators over the energy range of 20-20,000eV, and are of key importance for the investigation of liquid scintillation counting. PMID:21880497

Tan, Zhenyu; Xia, Yueyuan

2012-01-01

281

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

282

Electrophysical properties of ionic alloys of GaAs obtained by implanting Zn + (150 keV) with subsequent annealing at 500–1000°C  

Microsoft Academic Search

A study is made of the electrophysical properties (Ns, µeff) of ionic alloys of GaAs obtained by implanting 150-keV Zn ions at 20 and 300°C. The ion dose D=5·1013–1016 ions\\/cm2; the alloys were subsequently annealed for 10 min in an H2 atmosphere with temperatures in the range 500–1000°C. The optimal parameters of the ionic alloys are obtained for Ti=300°C and

B. S. Azikov; V. N. Brudnyi; I. V. Kamenskaya; M. A. Krivov; L. L. Shirokov

1979-01-01

283

Advances in Measurements of Ultrasound Fields in the Frequency Range 20- 60 MHz.  

National Technical Information Service (NTIS)

A powerful measurement technique suitable for virtually continuous calibration of ultrasonic hydrophone probes in the frequency range 250 kHz - 60 MHz is do scribed and frequency responses of PVDF polymer hydrophones are presented. The validity of the cal...

E. G. Radulescu P. A. Lewin A. Nowicki

2001-01-01

284

Short-range ordering in amorphous Fe20Ni60Si10B10  

Microsoft Academic Search

From 57Fe Mössbauer spectra of the amorphous ferromagnet Fe20Ni60Si10B10, it is inferred that the exchange interactions are determined by local chemical compositions. A variety of compositions throughout the sample leads to a large distribution of hyperfine magnetic fields at 57Fe nuclei. Previously unreported, the phenomenon is discussed with reference to recent x-ray data.

R. J. Pollard; Z. S. Wronski; A. H. Morrish

1985-01-01

285

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

286

50 CFR 30.2 - Disposition of surplus range animals.  

Code of Federal Regulations, 2010 CFR

...Disposition of surplus range animals. 30.2 Section 30.2 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT...CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM RANGE AND FERAL ANIMAL MANAGEMENT Range...

2009-10-01

287

50 CFR 30.2 - Disposition of surplus range animals.  

Code of Federal Regulations, 2010 CFR

...Disposition of surplus range animals. 30.2 Section 30.2 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT...CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM RANGE AND FERAL ANIMAL MANAGEMENT Range...

2010-10-01

288

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

289

Submicron, intense, pulsed x-ray source in the 2.5-10 keV energy range  

Microsoft Academic Search

An X pinch plasma is produced by exploding two 10-50 micron metal wires that cross and touch at a single point (in the form of an X) using a 200-400 kA, 100 ns (fwhm) current pulse. In the region of the original cross point of the wires, a magnetically driven plasma implosion occurs, and one or more <1 ns intense

David A. Hammer

2001-01-01

290

Experimental investigation of ligand effects on the conversion electron spectrum of the 22.5 keV M1 + E2 nuclear transition in 149 Sm  

Microsoft Academic Search

The conversion electron spectrum of the 22.5keV M1 + E2 nuclear transition in 149Sm from the electron capture decay of 149Eu was experimentally studied for the “Eu2O3” and “EuF3” compounds in which 149Eu ions have the same assumed oxidation number +3 . While the energies of the L, M, N, O, and P1 conversion lines for “EuF3” were lower, on

A. Kh. Inoyatov; L. L. Perevoshchikov; A. Kovalík; O. Dragoun; D. V. Filosofov

2011-01-01

291

17 CFR 20.2 - Covered contracts.  

Code of Federal Regulations, 2012 CFR

...Blendstock (RBOB). NYMEX Hot Rolled Coil Steel. NYMEX Natural Gas. NYMEX No. 2 Heating Oil, New York Harbor. NYMEX Palladium. NYMEX Platinum. NYMEX Sugar No. 11. NYMEX Uranium. Diversified Commodity Index (See §...

2012-04-01

292

Medium-Range Oscillatory Network and the 20Hz Sensorimotor Induced Potential  

Microsoft Academic Search

Although synchronously oscillating neuronal assemblies have been the subject of many studies, a clear identification of the spatiotemporal characteristics of a medium-range oscillatory network is still lacking. Herein, we present a method for the extraction of a new waveform, namely the mean induced potential (IP), which allows the identification of the spatiotemporal characteristics of induced EEG responses. The IP calculation

Andrea Brovelli; Piero Paolo Battaglini; Jose Raul Naranjo; Riccardo Budai

2002-01-01

293

Definition of spam 2.0: New spamming boom  

Microsoft Academic Search

The most widely recognized form of spam is e-mail spam, however the term “spam” is used to describe similar abuses in other media and mediums. Spam 2.0 (or Web 2.0 Spam) is refereed to as spam content that is hosted on online Web 2.0 applications. In this paper: we provide a definition of Spam 2.0, identify and explain different entities

Pedram Hayati; Vidyasagar Potdar; Alex Talevski; Nazanin Firoozeh; Saeed Sarenche; Elham A. Yeganeh

2010-01-01

294

26 CFR 20.2014-2 - âFirst limitationâ.  

Code of Federal Regulations, 2010 CFR

...of the ratio stated at § 20.2014-2(a)) ÷ $90,000 (factor D of the ratio stated at § 20.2014-2(a))] Ã$18,000 (factor...of the ratio stated at § 20.2014-2(a))= 12,000. ...12, 1973; 39 FR 2090, Jan. 17,...

2010-04-01

295

26 CFR 20.2014-2 - âFirst limitationâ.  

Code of Federal Regulations, 2010 CFR

...of the ratio stated at § 20.2014-2(a)) ÷ $90,000 (factor D of the ratio stated at § 20.2014-2(a))] Ã$18,000 (factor...of the ratio stated at § 20.2014-2(a))= 12,000. ...12, 1973; 39 FR 2090, Jan. 17,...

2009-04-01

296

Exploring Library 2.0 on the Social Web  

ERIC Educational Resources Information Center

Library 2.0 literature has described many of the possibilities Web 2.0 technologies offer to libraries. Case studies have assessed local use, but no studies have measured the Library 2.0 phenomenon by searching public social networking sites. This study used library-specific terms to search public social networking sites, blog search engines, and…

Brantley, John S.

2010-01-01

297

BSD Portals for LINUX 2.0  

Microsoft Academic Search

Portals, an experimental feature of 4.4BSD, extend the filesystem namespace by exporting certain open(2) requests to a user-space daemon. A portal daemon is mounted into the file namespace as if it were a standard filesystem. When the kernel resolves a pathname and encounters a portal mount point, the remainder of the path is passed to the portal daemon. De- pending

A. David McNab

298

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

299

Icosahedral short-range order in amorphous Cu80Si20 by ab initio molecular dynamics simulation study  

SciTech Connect

Short-range order in liquid and amorphous structures of Cu80Si20 is studied by ab initio molecular dynamics simulations. We performed the simulations at 1140 and 300 K respectively to investigate the local structure change from liquid to amorphous. The result of structure factor in comparison with experimental data indicates that our simulation of amorphous Cu80Si20 is reliable. By using the bond-angle distribution function, Honeycutt–Andersen index, Voronoi tessellation method, and the atomistic cluster alignment method, the icosahedral short-range order in the system is revealed. Strong Cu–Si interaction was also observed.

Wu, S.; Kramer, Matthew J.; Fang, Xiaowei; Wang, Shy-Guey; Wang, Cai-Zhuang; Ho, Kai-Ming; Ding, Z.J.; Chen, L.Y.

2012-04-26

300

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

301

Short-range correlations in carbon-12, oxygen-16, and neon-20: Intrinsic properties  

NASA Technical Reports Server (NTRS)

The Brueckner-Hartree-Fock (BHF) method has been applied to nuclei whose intrinsic structure is nonspherical. Reaction matrix elements were calculated as functions of starting energy for the Hamada-Johnston interaction using the Pauli operator appropriate to O-16 and a shifted oscillator spectrum for virtual excited states. Binding energies, single particle energies, radii, and shape deformations of the intrinsic state, in ordinary as well as renormalized BHF, are discussed and compared with previous HF studies and with experiment when possible. Results are presented for C-12, 0-16 and Ne-20. It is found that the binding energies and radii are too small, but that separation energies are well reproduced when the renormalized theory is used.

Braley, R. C.; Ford, W. F.; Becker, R. L.; Patterson, M. R.

1972-01-01

302

BioCat 2.0  

SciTech Connect

The U.S. Department of Homeland Security (DHS) National Biosurveillance Integration Center (NBIC) was established in 2008 with a primary mission to “(1) enhance the capability of the Federal Government to (A) rapidly identify, characterize, localize, and track a biological event of national concern by integrating and analyzing data relating to human health, animal, plant, food, and environmental monitoring systems (both national and international); and (B) disseminate alerts and other information to Member Agencies and, in coordination with (and where possible through) Member Agencies, to agencies of State, local, and tribal governments, as appropriate, to enhance the ability of such agencies to respond to a biological event of national concern; and (2) oversee development and operation of the National Biosurveillance Integration System (NBIS).” Inherent in its mission then and the broader NBIS, NBIC is concerned with the identification, understanding, and use of a variety of biosurveillance models and systems. The goal of this project is to characterize, evaluate, classify, and catalog existing disease forecast and prediction models that could provide operational decision support for recognizing a biological event having a potentially significant impact. Additionally, gaps should be identified and recommendations made on using disease models in an operational environment to support real-time decision making.

Corley, Courtney D.; Noonan, Christine F.; Bartholomew, Rachel A.; Franklin, Trisha L.; Hutchison, Janine R.; Lancaster, Mary J.; Madison, Michael C.; Piatt, Andrew W.

2013-09-16

303

30 CFR 20.9 - Class 2 lamps.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Class 2 lamps. 20.9 Section 20.9 Mineral Resources...AND APPROVAL OF MINING PRODUCTS ELECTRIC MINE LAMPS OTHER THAN STANDARD CAP LAMPS § 20.9 Class 2 lamps. (a) Safety....

2010-07-01

304

30 CFR 20.9 - Class 2 lamps.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Class 2 lamps. 20.9 Section 20.9 Mineral Resources...AND APPROVAL OF MINING PRODUCTS ELECTRIC MINE LAMPS OTHER THAN STANDARD CAP LAMPS § 20.9 Class 2 lamps. (a) Safety....

2009-07-01

305

Primary standard for the number concentration of liquid-borne particles in the 10 to 20 µm diameter range  

NASA Astrophysics Data System (ADS)

The national primary standard for the number concentration of liquid-borne particles in the 10 to 20 µm diameter range has been developed at the National Institute of Advanced Industrial Science and Technology (AIST), Japan. The standard consists of a total number counting type flow cytometer (T-FCM) and an electronic balance. The T-FCM is a commercial flow cytometer modified so that the total number of particles in an aqueous suspension sampled in a test tube can be counted, and the electronic balance is used to determine the mass of the suspension. This standard is intended to be used for calibrating commercial standard suspensions of monodisperse polystyrene latex (PSL) particles. The measurand in the calibration is the mass-based number concentration (the particle number in a unit mass of a suspension), and the calibration capability covers the concentration range from 5 × 102 to 2 × 106 particles g-1. When the concentration of the suspension is higher than 2 × 103 particles g-1, the suspension is first diluted to about 1 × 103 particles g-1 to suppress the coincidence loss in particle counting by the T-FCM. The validity of the calibration with the T-FCM was examined by comparison with an independent method in which a scanning electron microscope (SEM) was used to determine the number concentration of particles deposited on a silicon wafer. For a suspension of 10 µm PSL particles with a concentration of approximately 1 × 106 particles g-1, the concentration values determined by the T-FCM and SEM methods were 1.042 × 106 and 1.035 × 106 particles g-1, respectively: The difference was less than 0.7%. The relative expanded uncertainty of the measurement by the T-FCM method with the coverage factor k = 2 was 4.4%.

Sakaguchi, T.; Ehara, K.

2011-02-01

306

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

Code of Federal Regulations, 2013 CFR

...ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.20 Gulf of...Maine; naval aircraft practice mining range area. (a) The danger zone. Within an area bounded as follows: Beginning at latitude...

2013-07-01

307

Investigating the Unknown Nuclear Reaction in a Low-Energy (E < 330 keV) p + Ti{sup 2}H{sub x} Experiment  

SciTech Connect

Charged-particle products with {approx}3.9-MeV energy were observed in a low-energy experiment (E{sub p} {<=} 330 keV) with a proton bombarding a Ti{sup 2}H{sub x} target. The features of the charged-particle products were the same as those of an alpha particle. The threshold of the reaction was {approx}150 keV. The maximum reaction rate reached more than 10{sup 5} r/s, while the proton energy and current were 324 keV and 1.2 mA, respectively. The excitation curve of this unknown reaction increased exponentially with the growth of proton energy. There is no known nuclear reaction induced by a proton that can be applied to interpret this experimental phenomenon. Some interpretations, e.g., an indirect secondary reaction and a multibody reaction model, are discussed, but the origin of this unknown nuclear reaction is still a mystery and under study.

Wang Tieshan [Chinese Academy of Sciences (China); Wang Zhiguo [Chinese Academy of Sciences (China); Chen Jingen [Lanzhou University (China); Jin Genming [Chinese Academy of Sciences (China); Piao Yubo [Lanzhou University (China)

2000-03-15

308

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

309

The x-ray calibration facility of the laser integration line in the 0.9-10 keV range: The high energy x-ray source and some applications  

NASA Astrophysics Data System (ADS)

The laser integration line (LIL) located at CEA-CESTA is equipped with x-ray plasma diagnostics using different kinds of x-ray components such as filters, mirrors, crystals, detectors, and cameras. The CEA-DAM of Arpajon is currently developing x-ray calibration methods and carrying out absolute calibration of LIL x-ray photodetectors. To guarantee LIL measurements, detectors such as x-ray cameras must be regularly calibrated close to the facility. A new x-ray facility is currently available to perform these absolute x-ray calibrations. This paper presents the x-ray tube based high energy x-ray source delivering x-ray energies ranging from 0.9 to 10 keV by means of an anode barrel. The purpose of this source is mainly to calibrate LIL x-ray cameras but it can also be used to measure x-ray filter transmission of plasma diagnostics. Different x-ray absolute calibrations such as x-ray streak and framing camera yields, x-ray charge-coupled device quantum efficiencies, and x-ray filter transmissions are presented in this paper. A x-ray flat photocathode detector sensitivity calibration recently performed for a CEA Z-pinch facility is also presented.

Hubert, S.; Dubois, J. L.; Gontier, D.; Lidove, G.; Reverdin, C.; Soullié, G.; Stemmler, P.; Villette, B.

2010-05-01

310

Structural basis for receptor sharing and activation by interleukin-20 receptor-2 (IL-20R2) binding cytokines.  

PubMed

Interleukin 20 (IL-20) is a pleotropic IL-10 family cytokine that protects epithelial surfaces from pathogens. However, dysregulated IL-20 signaling is implicated in several human pathologies including psoriasis, rheumatoid arthritis, atherosclerosis, and osteoporosis. IL-20, and related cytokines IL-19 and IL-24, designated IL-20 subfamily cytokines (IL-20SFCs), induce cellular responses through an IL-20R1/IL-20R2 (type I) receptor heterodimer, whereas IL-20 and IL-24 also signal through the IL-22R1/IL-20R2 (type II) receptor complex. The crystal structure of the IL-20/IL-20R1/IL-20R2 complex reveals how type I and II complexes discriminate cognate from noncognate ligands. The structure also defines how the receptor-cytokine interfaces are affinity tuned to allow distinct signaling through a receptor complex shared by three different ligands. Our results provide unique insights into the complexity of IL-20SFC signaling that may be critical in the design of mechanistic-based inhibitors of IL-20SFC-mediated inflammatory disease. PMID:22802649

Logsdon, Naomi J; Deshpande, Ashlesha; Harris, Bethany D; Rajashankar, Kanagalaghatta R; Walter, Mark R

2012-07-31

311

2-2 PZT-polymer composites for high frequency (>20 MHz) ultrasound transducers  

Microsoft Academic Search

The aim of this research is to produce single element and array transducers with resonance frequencies ranging from 20 to 50 MHz. By using tape-cast PZT with fugitive phase, PZT\\/polymer 2-2 composites can be made for higher sensitivity and bandwidth than existing high frequency technologies. Tape casting methods for fabricating 2-2 PZT\\/polymer composites were developed with specific emphasis placed on

Wesley Hackenberger; Seongtae Kwon; Paul Rehrig; Kevin Snook; Sorah Rhee

2002-01-01

312

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

313

(H2O)20 Water Clusters at Finite Temperatures  

NASA Astrophysics Data System (ADS)

We have performed an exhaustive study of energetics of (H2O)20 clusters. Our goal is to study the role that various free-energy terms play in this popular model system and see their effects on the distribution of the (H2O)20 clusters and in the infrared spectrum at finite temperatures. In more detail, we have studied the electronic ground-state structure energy and its long-range correlation (dispersion) part, vibrational zero-point corrections, vibrational entropy, and proton configurational entropy. Our results indicate a delicate competition between the energy terms; polyhedral water clusters are destabilized by dispersion interaction, while vibrational terms (zero-point and entropic) together with proton disorder entropy favor them against compact structural motifs, such as the pentagonal edge- or face-sharing prisms. Apart from small water clusters, our results can be used to understand the influence of these energy terms in water/ice systems in general. We have also developed energy expressions as a function of both earlier proposed and novel hydrogen-bond connectivity parameters for prismatic water clusters.

Parkkinen, P.; Riikonen, S.; Halonen, L.

2013-10-01

314

(H2O)20 water clusters at finite temperatures.  

PubMed

We have performed an exhaustive study of energetics of (H2O)20 clusters. Our goal is to study the role that various free-energy terms play in this popular model system and see their effects on the distribution of the (H2O)20 clusters and in the infrared spectrum at finite temperatures. In more detail, we have studied the electronic ground-state structure energy and its long-range correlation (dispersion) part, vibrational zero-point corrections, vibrational entropy, and proton configurational entropy. Our results indicate a delicate competition between the energy terms; polyhedral water clusters are destabilized by dispersion interaction, while vibrational terms (zero-point and entropic) together with proton disorder entropy favor them against compact structural motifs, such as the pentagonal edge- or face-sharing prisms. Apart from small water clusters, our results can be used to understand the influence of these energy terms in water/ice systems in general. We have also developed energy expressions as a function of both earlier proposed and novel hydrogen-bond connectivity parameters for prismatic water clusters. PMID:23731161

Parkkinen, P; Riikonen, S; Halonen, L

2013-10-01

315

TLM 2.0 simple sockets synthesis to RTL  

Microsoft Academic Search

Convenience sockets are a family of derived sockets provided in utilities namespace of TLM 2.0 library which add additional functionalities to TLM 2.0 sockets. As one of the goals of high level modeling is to part communication from computation, synthesizing communication mechanisms including sockets can be a primary step to synthesize each TLM 2.0 design on RTL. Synthesizing sockets on

Nadereh Hatami; Amirali Ghofrani; Paolo Prinetto; Zainalabedin Navabi

2009-01-01

316

Purification, crystallization and preliminary X-ray diffraction analysis of the IL20IL20R1IL20R2 complex  

Microsoft Academic Search

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

Naomi J. Logsdon; Christopher E. Allen; Kanagalaghatta R. Rajashankar; Mark R. Walter

2012-01-01

317

The dielectric properties of biological tissues: II. Measurements in the frequency range 10 Hz to 20 GHz.  

PubMed

Three experimental techniques based on automatic swept-frequency network and impedance analysers were used to measure the dielectric properties of tissue in the frequency range 10 Hz to 20 GHz. The technique used in conjunction with the impedance analyser is described. Results are given for a number of human and animal tissues, at body temperature, across the frequency range, demonstrating that good agreement was achieved between measurements using the three pieces of equipment. Moreover, the measured values fall well within the body of corresponding literature data. PMID:8938025

Gabriel, S; Lau, R W; Gabriel, C

1996-11-01

318

X-ray (17 -- 99-keV) diagnostics for the 200-TW Trident Laser  

NASA Astrophysics Data System (ADS)

The sub-ps Trident laser can deliver >100 J on target. The target irradiance is ˜10^20 W/cm^2. X-ray diagnostics include a Laue x-ray spectrograph, a Ross filter pair to measure conversion efficiency of laser light to K-shell emission, and a single-photon-counting x-ray CCD camera. For the Laue instrument, we discuss design features used to limit corruption of the recorded spectra by ˜MeV electrons and bremsstrahlung: a tungsten shield in the front, low-Z, thick-wall construction materials, magnetic traps, light traps, and a special sandwich-style film holder. For the Laue geometry where a LiF 200 crystal has a bandpass of 17 - 70 keV, LiF 220 shifts the bandpass to 24 - 99 keV. The sensitivity of Si p-i-n diodes is adequate to record x-ray emission up to ˜100 keV. With a carefully matched Ross filter pair, we may estimate the signal between the filter edges of two channels through subtraction of signals. The K-shell emission is expected to exceed the continuum contribution to the signal. These instruments will be employed to optimize the efficiency of x-ray backlighters in this energy range. The x-ray CCD is discussed in a parallel poster.

Cobble, James; Workman, Jonathan; Vutisalchavakul, Nalin

2008-11-01

319

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

320

Using web 2.0 for health promotion and social marketing efforts: lessons learned from web 2.0 experts.  

PubMed

Web 2.0 experts working in social marketing participated in qualitative in-depth interviews. The research aimed to document the current state of Web 2.0 practice. Perceived strengths (such as the viral nature of Web 2.0) and weaknesses (such as the time consuming effort it took to learn new Web 2.0 platforms) existed when using Web 2.0 platforms for campaigns. Lessons learned were identified-namely, suggestions for engaging in specific types of content creation strategies (such as plain language and transparent communication practices). Findings present originality and value to practitioners working in social marketing who want to effectively use Web 2.0. PMID:24878406

Dooley, Jennifer Allyson; Jones, Sandra C; Iverson, Don

2014-01-01

321

Research 2.0: A Framework for Qualitative and Quantitative Research in Web 2.0 Environments  

Microsoft Academic Search

The paper explores the potential of the Web 2.0 environment for conducting both qualitative and quantitative research. The paper analyzes the emerging Research 2.0 domain using the theoretical framework of Web 2.0 core principles (e.g., web as a platform, harnessing collective intelligence, etc.). These principles, first proposed by Tim O'Reilly, provide a useful lens through which researchers can examine the

Dinesh Rathi; Lisa M. Given

2010-01-01

322

New and Innovative Library Services: Moving with Web 2.0 / Library 2.0 Technology, a Case Study  

NASA Astrophysics Data System (ADS)

We give an overview and definition of Web 2.0 and Library 2.0 technology, especially addressing how it changes access to collections for users. We also describe its unlimited possibilities. The various components of Library 2.0 viz blogs, wikis, RSS, instant messaging, social networking, podcasting, and tagging are briefly summarized. Initiatives at three special information centers and libraries (IUCAA — Astronomy and Astrophysics; IIT — Science and Technology; and NIV — Viral Diseases) are described. We conclude with a futuristic view of Library 2.0.

Sahu, H. K.; Pathak, S. K.; Singh, S. N.

2010-10-01

323

Power supply for the LBL 40 keV neutral beam source  

SciTech Connect

A 20 keV, 50 Amp, 10 millisec pulse D$sup 0$ Neutral Beam Source at the Lawrence Berkeley Laboratory that serves as the prototype for 12 similar sources now in operation on the 2XIIB Mirror Machine at the Lawrence Livermore Laboratory has been recently upgraded to operate at 40 keV. The system of electronically regulated and controlled power supplies that drive the Source is described. (auth)

Baker, W.R.; Fitzgerald, M.L.; Honey, V.J.

1975-11-01

324

Unleashing the Power of Web 2.0  

ERIC Educational Resources Information Center

As Web 2.0 technologies impact the evolution of online learning, they are certain to blur the definitional lines between electronic portfolios and personal learning environments (PLEs). According to Gary Brown, director of Washington State University's Center for Teaching, Learning, and Technology, the Web 2.0 technologies that are emerging…

Waters, John K.

2008-01-01

325

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

326

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

327

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

328

Scenarios and Strategies for Web 2.0  

ERIC Educational Resources Information Center

Purpose: The aim of this article is to bring together ideas from the authors' review of the Web 2.0 literature, the data and their insights from this and other technology-related projects to produce a framework for strategies on Web 2.0 focusing on the implications for human resource professionals. Design/methodology/approach: The authors discuss…

Martin, Graeme; Reddington, Martin; Kneafsey, Mary Beth; Sloman, Martyn

2009-01-01

329

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

330

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

331

Ubiquitous Complete in a Web 2.0 World  

ERIC Educational Resources Information Center

In the third wave of computing, people will interact with multiple computers in multiple ways in every setting. The value of ubiquitous computing is enhanced and reinforced by another trend: the transition to a Web 2.0 world. In a Web 2.0 world, applications and data reside on the Web itself. Schools are not yet approaching a ratio of one…

Bull, Glen; Ferster, Bill

2006-01-01

332

User's Manual Frac-Explore 2.0.  

National Technical Information Service (NTIS)

FRAC-EXPLORE 2.0, a new computer software package for oi and gas exploration using surface lineament and fracture analysis. FRAC-EXPLORE 2.0 provides a suite of tools for analyzing the characteristics and patterns of surface lineaments and fractures, as w...

S. A. George G. Guo

1999-01-01

333

Information Literacy 2.0: Empowering Students through Personal Engagement  

ERIC Educational Resources Information Center

Web 2.0 technologies such as blogs, wikis, and social networking sites have impacted the Information Literacy (IL) curriculum at The American University in Cairo, where librarians teach LALT 101, a required, semester-long IL course. During fall 2005 and spring 2006, librarians used a Web 2.0 photo sharing tool, Flickr (www.flickr.com), to teach…

Brown, Nicole E.; Bussert, Kaila

2007-01-01

334

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

335

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

336

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

337

Alignment of the 1[ital s]2[ital p] vacancy states of Ne doubly ionized by 700--2000-keV proton impact  

SciTech Connect

The angular distribution of [ital KL][sub 23-][ital LLL][sub 23] Auger electrons emitted from the decay of 1[ital s]2[ital p] vacancy states of Ne doubly ionized by 700--2000-keV protons has been measured. From the measured anisotropy of the Auger lines the alignment of the double-vacancy states has been deduced. Our data compared with different theories indicate that the shake-off plays an important role in the double-ionization process at these energies.

Takacs, E.; Ricz, S.; Vegh, J.; Kadar, I.; Palinkas, J.; Sulik, B.; Toth, L.; Berenyi, D. (Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), POB 51, H-4001 Debrecen (Hungary)); Kabachnik, N.M. (Institute of Nuclear Physics, Moscow State University, Moscow 119899 (Russian Federation))

1994-08-01

338

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

339

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

340

Energy Demand in China (Carbon Cycle 2.0)  

ScienceCinema

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

2011-06-08

341

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

342

Total Electron Stopping Powers and CSDA-Ranges from 20 eV to 10 MeV Electron Energies for Components of DNA and RNA  

NASA Astrophysics Data System (ADS)

An appropriate formula for the total stopping power of electrons of initial kinetic energy from 20 eV to 10 MeV in some biological materials is presented. The continuous slowing down approximation-range (CSDA-range) from the total stopping power is also made. The collisional stopping power formula is evaluated using Generalized Oscillator Strength (GOS) model and exchange correction on the inelastic differential cross section (IDCS) given by [M. Inokuti, Rev. Mod. Phys. 43 (1971) 297-347] and the radiative stopping power formula is calculated from the bremsstrahlung differential cross section (DCS) given by [H.W. Koch, J.W. Motz, Rev. Mod. Phys. 31 (4) (1959) 920-955]. Calculation of the total stopping powers (SPs) and CSDA-range for biological compounds: C5H5N5 (adenine), C5H5N5O (guanine), C4H5N3O (cytosine), C5H6N2O2 (thymine), C4H4N2O2 (uracil), C4H8O (tetrahydrofuran), C4H8O2 (3-hydroxytetrahydrofuran), C5H10O2 ([alpha]-tetrahydrofurfuryl alcohol), H3PO4 (phosphoric acid), C19H26N8O13P2 (thymineadenineDNA) have been introduced for incident electrons in the 20 eV-10 MeV energy range. The calculated results have been compared with experimental data, PENELOPE program results and other theoretical results. The calculated results of total stopping power and CSDA-ranges for electrons in energy range from 20 eV to 10 MeV are found to be in good agreement to within 8% with available data.

Akar, A.; Gümüs, H.; Okumusoglu, N. T.

343

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

344

36 CFR 222.2 - Management of the range environment.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Management of the range environment. 222.2 Section 222.2 Parks, Forests, and Public...National Forest System § 222.2 Management of the range environment. (a) Allotments will be designated on the...

2013-07-01

345

FLIRT - Interest regions for 2D range data  

Microsoft Academic Search

Local image features are used for a wide range of applications in computer vision and range imaging. While there is a great variety of detector-descriptor combinations for image data and 3D point clouds, there is no general method readily available for 2D range data. For this reason, the paper first proposes a set of benchmark experiments on detector repeatability and

Gian Diego Tipaldi; Kai Oliver Arras

2010-01-01

346

Experimental Determination of Sensitivity of DN-A-1 Dosimeter and exp 6 LiJ(Eu) Scintillation Detector in Sphere Polyethylene Moderators in the 30 KeV Neutron Energy Range.  

National Technical Information Service (NTIS)

DH-A-1 dosimeter and exp 6 LiJ(Eu) detector, located in the center of polyethylene spheres with various diameters, were calibrated by means of neutrons with the energy of about 30 keV. The data on the detectors responses enable one to determine the shape ...

V. E. Aleinikov L. G. Beskrovnaya M. M. Komochkov Y. V. Mokrov S. P. Prusachenkov

1979-01-01

347

An accuracy assessment of photo-ionization cross-section datasets for 1-2 keV x-rays in light elements using PIXE  

NASA Astrophysics Data System (ADS)

Proton-induced x-ray emission (PIXE) was used to assess the accuracy of the National Institute of Standards and Technology XCOM and FFAST photo-ionization cross-section databases in the low energy region (1-2 keV) for light elements. Characteristic x-ray yields generated in thick samples of Mg, Al and Si in elemental and oxide form, were compared to fundamental parameters computations of the expected x-ray yields; the database for this computation included XCOM attenuation coefficients. The resultant PIXE instrumental efficiency constant was found to differ by 4-6% between each element and its oxide. This discrepancy was traced to use of the XCOM Hartree-Slater photo-electric cross-sections. Substitution of the FFAST Hartree-Slater cross-sections reduced the effect. This suggests that for 1-2 keV x-rays in light element absorbers, the FFAST predictions of the photo-electric cross-sections are more accurate than the XCOM values.

Heirwegh, C. M.; Pradler, I.; Campbell, J. L.

2013-09-01

348

The Measurements of the Differential Elastic Neutron Cross-Sections of Carbon for Energies from 2 TO 133 keV  

NASA Astrophysics Data System (ADS)

The measurements of the differential elastic neutron cross-sections of carbon have been carried out at the Kyiv Research Reactor (KRR) using the neutron filter beam technique. Experimental set-up for detection of scattered neutrons has been installed at the eighth horizontal channel of the KRR. The quasi-mono-energetic neutron lines with mean energies 2, 59 and 133 keV were formed by composite filters. The measurements of the angle distribution of scattering neutrons on carbon samples were executed at angles 30°, 55°, 90°, 125° and 150° for three neutron energies. To determine the differential elastic neutron cross-section on carbon d?/d?, the relative method of measurement was used. The isotope 208Pb was used as a standard. The normalization factor, which is a function of detector efficiency, thickness of the carbon samples, thickness of the Pb-208 sample, geometry, etc., for each sample and for each filter energy has been obtained through Monte Carlo calculations by means of own codes. The results of measurements of the differential elastic neutron cross sections on carbon samples at reactor neutron filtered beams with energies 2, 59, and 133 keV have been compared with the known experimental data from database EXFOR/CSISRS.

Gritzay, Olena; Kolotyi, Volodymyr; Pshenychnyi, Volodymyr; Klimova, Nataliia; Libman, Volodymyr; Venedyktov, Vitalii; Richardson, Jeffery; Sale, Kenneth

2009-08-01

349

100 Megacycle VHF Re-Entry Radar for Stallion Site, White Sands Missile Range, AN/TPQ-20.  

National Technical Information Service (NTIS)

A 100-megacycle, 1-megawatt, variable pulse width (1, 2.5 and 5 microseconds) radar, the AN/TPQ-20, was installed at the Stallion Site, White Sands, New Mexico, for the purpose of viewing and photographically recording A-scope displays of the Athena test ...

1964-01-01

350

Total detachment cross sections of C-, CH-, C2-, and C2H- incident on N2 at keV energies  

NASA Astrophysics Data System (ADS)

We have measured the total electron detachment cross sections of the negative ions C-, CH-, C2-, and C2H- incident on molecular nitrogen in the velocity range 0.22-0.56 a.u. The data were measured with reliable normalization and, particularly in the critical case of the C- projectile, the absence of beam contamination due to long-lived metastable states. Comparison of all measurements of cross sections with experimental data for other projectiles shows a common velocity dependence with a maximum near 0.4 a.u. This behavior suggests a connection between the anion-N2 electron-loss collision dynamics and that of the shape-resonance process dominant in low-velocity electron-N2 total electron scattering.

Nascimento, R. F.; Mello, S. L. A.; Magnani, B. F.; Sant'Anna, M. M.; Jalbert, Ginette; de Castro Faria, N. V.

2013-06-01

351

Diffusion of chromium and aluminum in Ni-20Cr and TDNiCr /Ni-20Cr-2ThO2/.  

NASA Technical Reports Server (NTRS)

Diffusion coefficients have been measured for Cr51 in fine- and coarse-grained TDNiCr (Ni-20Cr-2ThO2) and in fine-grained Ni-20Cr in the temperature range from 1038 to 1200 C. Selective diffusivities have also been determined for specimens of these alloys which were aluminized to give an initial surface concentration of 5.8 wt % Al. Finally, diffusion coefficients for interdiffusion of aluminum in TDNiCr and Ni-20Cr have been obtained from electron probe microanalysis of the aluminized specimens. For a given grain size and temperature there is no difference in diffusivities for chromium diffusion in TDNiCr or Ni-20Cr. Diffusion coefficients increase with decreasing grain size for both alloys. Comparison of aluminum diffusion data obtained from electron microprobe profiles with radiotracer chromium diffusivities suggests that aluminum diffuses approximately three times faster than chromium in TDNiCr and Ni-20Cr.

Seltzer, M. S.; Wilcox, B. A.

1972-01-01

352

Observations of 10-eV to 25-keV electrons in steady diffuse aurora from Atmosphere Explorer C and D  

NASA Technical Reports Server (NTRS)

Electron energy spectra from 10 eV to 25 keV have been obtained from steady diffuse auroral forms at altitudes above 150 km by the Atmosphere Explorer C and D spacecraft. Overlapping coverage of the energy range was provided by the photoelectron spectrometer experiment (10-500 eV) and the low-energy electron experiment (0.2-25 keV). The spectral shape between 10 and 20 eV is independent of altitude between 150 and 270 km, has variable energy dependence between about 20 and 150 eV, and above approximately 150 eV has energy dependence determined primarily by the details of the energy spectrum of electrons incident on the atmosphere. The observed results are in satisfactory agreement with two recently published model calculations.

Peterson, W. K.; Doering, J. P.; Potemra, T. A.; Mcentire, R. W.; Bostrom, C. O.; Hoffman, R. A.; Janetzke, R. W.; Burch, J. L.

1977-01-01

353

Nickel nanoparticles dispersed in SiO2 fabricated by high-flux negative-ion implantation of 60 keV  

NASA Astrophysics Data System (ADS)

The magnetic nanoparticles are fabricated in silica glass (SiO2) using high-flux implantation of nickel negative-ions of 60 keV. Photo-absorption measurements and the cross-sectional transmission electron microscopy (XTEM) observation confirm formation of metallic Ni nanoparticles in SiO2, and exclude possible formation of Ni silicides (Ni3Si, Ni2Si, NiSi) and oxides (NiO) as major products. The mean diameter of the nanoparticles was in ~2.9 nm, and the depth distribution was similar to the prediction from the TRIDYN code with taking account of the sputtering. Temperature- and field- dependences of magnetization show that the nanoparticles are in the super-paramagnetic state with a blocking temperature of ~27 K.

Amekura, Hiroshi; Kitazawa, Hideaki; Mochiku, Takashi; Umeda, Naoki; Takeda, Yoshihiko; Kishimoto, Naoki

2002-12-01

354

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

Code of Federal Regulations, 2013 CFR

... RESOURCE 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...

2013-07-01

355

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

356

Program Management Challenges of Web 2.0.  

National Technical Information Service (NTIS)

In this Joint Applied Project, the author discusses the various Program Management challenges presented by Web 2.0 (technical and non- technical). The challenges are categorized into eight major areas: cost, schedule, performance, technologies, process, p...

Y. K. Woodall

2010-01-01

357

26 CFR 20.2013-2 - âFirst limitationâ.  

Code of Federal Regulations, 2013 CFR

...INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) ESTATE AND GIFT TAXES ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 Credits Against Tax § 20.2013-2 âFirst limitationâ. (a) The amount of the...

2013-04-01

358

26 CFR 20.2014-2 - âFirst limitationâ.  

Code of Federal Regulations, 2013 CFR

...INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) ESTATE AND GIFT TAXES ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 Credits Against Tax § 20.2014-2 âFirst limitationâ. (a) The amount of a...

2013-04-01

359

26 CFR 20.6091-2 - Exceptional cases.  

Code of Federal Regulations, 2013 CFR

...INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) ESTATE AND GIFT TAXES ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 Procedure and Administration § 20.6091-2 Exceptional cases. Notwithstanding the...

2013-04-01

360

26 CFR 20.7520-2 - Valuation of charitable interests.  

Code of Federal Regulations, 2013 CFR

...INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) ESTATE AND GIFT TAXES ESTATE TAX; ESTATES OF DECEDENTS DYING AFTER AUGUST 16, 1954 General Actuarial Valuations § 20.7520-2 Valuation of charitable interests. (a) In...

2013-04-01

361

Federal Enterprise Architecture Program EA Assessment Framework 2.0.  

National Technical Information Service (NTIS)

Version 2.0 of the Office of Management and Budget (OMB) Enterprise Architecture Assessment Framework is designed to advance the use of enterprise architecture (EA) across the Federal government. This document will serve as the basis for enterprise archit...

2005-01-01

362

2. SANDY RIVER BRIDGE AT TROUTDALE, SOUTH END, LOOKING 20 ...  

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

2. SANDY RIVER BRIDGE AT TROUTDALE, SOUTH END, LOOKING 20 DEGREES NORTH. - Historic Columbia River Highway, Sandy River Bridge at Troutdale, Historic Columbia River Highway spanning Sandy River, Troutdale, Multnomah County, OR

363

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

364

RadCat 2.0 User Guide.  

SciTech Connect

This document provides a detailed discussion and a guide for the use of the RadCat 2.0 Graphical User Interface input file generator for the RADTRAN 5.5 code. The differences between RadCat 2.0 and RadCat 1.0 can be attributed to the differences between RADTRAN 5 and RADTRAN 5.5 as well as clarification for some of the input parameters. 3

Osborn, Douglas.; Weiner, Ruth F.; Mills, George Scott; Hamp, Steve C.; O'Donnell, Brandon, M.; Orcutt, David J.; Heames, Terence J.; Hinojosa, Daniel

2005-01-01

365

WebQuests and Web 2.0 Screen Design  

Microsoft Academic Search

This study compared the designs of a traditional style WebQuest and a Web 2.0 style WebQuest in terms of their effectiveness as a teaching tool. The sample included 104 university sophomore students. Students were randomly assigned to two groups, with one group using the traditional style WebQuest and the other used the Web 2.0 style WebQuest. Data were collected (a)

Serhat Kurt

2010-01-01

366

Web 2.0: blind to an accessible new world  

Microsoft Academic Search

With the advent of Web 2.0 technologies, websites have evolved from static pages to dynamic, interactive Web-based applications with the ability to replicate common desktop functionality. However, for blind and visually impaired individuals who rely upon screen readers, Web 2.0 applications force them to adapt to an inaccessible use model. Many technologies, including WAI- ARIA, AJAX, and improved screen reader

Joshua M. Hailpern; Loretta Guarino Reid; Richard Boardman; Srinivas Annam

2009-01-01

367

Cross section measurements of the 10B(p ,?)11C reaction between 2.0 and 6.0 MeV  

NASA Astrophysics Data System (ADS)

The total cross section of the 10B(p,?)11C reaction has been measured for bombarding proton energies between 2.0 and 6.0 MeV in 500 keV steps for the first time. This reaction is important for potential next-generation boron fueled nuclear reactors. The total cross section was measured by activating a 10B target with protons and, after stopping the beam, detecting the 511 keV ? rays emitted from the ?+ decay of 11C, using two LaBr3:Ce detectors. In addition to the total cross sections, astrophysical S factors were also calculated at each energy.

Kafkarkou, A.; Ahmed, M. W.; Kendellen, D. P.; Mazumdar, I.; Mueller, J. M.; Myers, L. S.; Sikora, M. H.; Weller, H. R.; Zimmerman, W. R.

2014-01-01

368

Energy loss and straggling for 50- and 100-keV H{sup +} ions passing through the Si(001)2{times}1-Sb surface  

SciTech Connect

Surface stopping powers were measured for 50- and 100-keV H{sup +} ions passing through the Si(001)2{times}1-Sb surface. The energy losses as a function of the exit angle are fit successfully by a simple relationship involving the time spent near the surface. The fitting parameter is in agreement with the value expected from the bulk Sb stopping cross section and the areal Sb density. This result suggests continuity of the stopping power from the bulk to the surface. It provides a useful method for determining the distance between the plane of deposited atoms and of a substrate surface and for measuring the composition of the topmost atomic layer. The estimated energy loss by surface-plasmon excitation is negligibly small in the present system. The energy straggling as a function of exit angle was also measured for 50- and 100-keV H{sup +} incidence and the results are compared here with the bulk straggling values. {copyright} {ital 1997} {ital The American Physical Society}

Sumitomo, K.; Nishioka, T. [NTT Basic Research Laboratories, Atsugi, Kanagawa 243-01 (Japan)] [NTT Basic Research Laboratories, Atsugi, Kanagawa 243-01 (Japan); Ikeda, A.; Kido, Y. [Department of Physics, Ritsumeikan University, Kusatsu, Shiga 525-77 (Japan)] [Department of Physics, Ritsumeikan University, Kusatsu, Shiga 525-77 (Japan)

1997-09-01

369

Formation of ?-FeSi2 by ion implantation of 90 keV Fe10+ ions on N-type silicon  

NASA Astrophysics Data System (ADS)

The semiconducting disilicide of the Fe-Si binary system ?-FeSi2 has been synthesized by the Ion Beam Synthesis (IBS) technique. High purity n-type float zone silicon wafers have been irradiated at various fluences from 5×1015 to 1×1017 by Fe10+ beam at 90 keV using a ECR based low energy ion beam implanter. The irradiated samples were annealed in pure argon ambient at 900°C for 1 hour. GIXRD measurements were done at 0.5 degree incidence on the irradiated samples and the beta phase was identified. Raman measurements confirm the existence of ?-FeSi2. In addition to the semiconducting ?-FeSi2 phase, the sample irradiated with the highest dose contains the metallic alpha phase. The transition from beta to alpha phase observed in the sample that is annealed at relatively lower temperature has been assigned to the presence of lattice defects.

Rajesh, P. V.; Pati, S. P.; Krishna, J. B. M.; Ghosh, B.; Das, D.

2012-06-01

370

Absolute total, one-, two-, and three-electron-transfer cross sections for Arq+ (8<=q<=16) on Ar at 2.3q keV  

NASA Astrophysics Data System (ADS)

Absolute values for the total, one-, two-, and three-electron-transfer cross sections for Arq+ ions (8<=q<=16) colliding with argon at 2.3q keV laboratory energy were measured by the growth-rate method. The Arq+ ions were produced by the Cornell superconducting solenoid, cryogenic electron-beam ion source (CEBIS) and extracted at 2.3 kV. Selected charge states traversed a gas cell, after which they were detected and charge-state analyzed by the energy-retardation method and by a ?/ ?2 cylindrical electrostatic analyzer. The target gas pressure in the cell was measured directly by the orifice flow method used for absolute pressure-gauge calibration. The overall error in the Arq+ on Ar cross-section measurements is +/-10%.

Vancura, J.; Perotti, J. J.; Flidr, J.; Kostroun, V. O.

1994-04-01

371

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

SciTech Connect

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

Arjomandy, Bijan; Tailor, Ramesh; Anand, Aman; Sahoo, Narayan; Gillin, Michael; Prado, Karl; Vicic, Milos [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, Texas 77030 (United States)

2010-05-15

372

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.

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

2012-01-01

373

Low Cost Solar Energy Conversion (Carbon Cycle 2.0)  

ScienceCinema

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

2011-06-08

374

YBCO film deposition on very large areas up to 20 × 20 cm2  

NASA Astrophysics Data System (ADS)

In the last decade we have developed thermal reactive co-evaporation as a technique to produce high quality YBCO and other oxide films of very large size up to 9 inches in diameter. This was achieved by intermittent deposition and reaction with oxygen using a heater which rotates the substrate in and out of an oxygen pocket. Even larger substrates, e. g. coated conductors, cannot be rotated. Therefore we have recently developed a new setup where the substrate is held fixed, and the oxygen pocket is set in linear reciprocation. This technique allows simultaneous deposition on a square of 20×20 cm 2. Moreover, we have developed an instant refill mechanism for the thermal boats, and stable rate control by atomic absorption spectroscopy (AAS), in order to obtain a continuous process suitable for small scale mass production.

Kinder, H.; Berberich, P.; Prusseit, W.; Rieder-Zecha, S.; Semerad, R.; Utz, B.

1997-08-01

375

Wine 2.0—The Next Phase of Wine Marketing? Exploring US Winery Adoption of Wine 2.0 Components  

Microsoft Academic Search

The advent of Wine 2.0—which incorporates components such as social networking, blogs, vlogs, and interactive e-commerce—has the potential to change the way wine consumers interact with wineries, wine retailers, and fellow wine consumers. This research study of 208 US wineries investigates to what extent wineries are adopting Wine 2.0 components as part of their marketing strategy, and how well they

Liz Thach

2009-01-01

376

NASA Marshall Engineering Thermosphere Model. 2.0  

NASA Technical Reports Server (NTRS)

This Technical Memorandum describes the NASA Marshall Engineering Thermosphere Model-Version 2.0 (MET-V 2.0) and contains an explanation on the use of the computer program along with an example of the MET-V 2.0 model products. The MET-V 2.0 provides an update to the 1988 version of the model. It provides information on the total mass density, temperature, and individual species number densities for any altitude between 90 and 2,500 km as a function of latitude, longitude, time, and solar and geomagnetic activity. A description is given for use of estimated future 13-mo smoothed solar flux and geomagnetic index values as input to the model. Address technical questions on the MET-V 2.0 and associated computer program to Jerry K. Owens, Spaceflight Experiments Group, Marshall Space Flight Center, Huntsville, AL 35812 (256-961-7576; e-mail Jerry.Owens@msfc.nasa.gov).

Owens, J. K.

2002-01-01

377

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

378

Geologic Carbon Sequestration and Biosequestration (Carbon Cycle 2.0)  

ScienceCinema

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/

379

Carbon Cycle 2.0: Paul Alivisatos: Introduction  

ScienceCinema

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/

380

Carbon Cycle 2.0: Paul Alivisatos: Introduction  

ScienceCinema

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

2010-09-01

381

Geologic Carbon Sequestration and Biosequestration (Carbon Cycle 2.0)  

ScienceCinema

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

2011-06-08

382

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

383

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

384

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

PubMed

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(1)2(1)2 or P4(3)2(1)2, with unit-cell parameters a = 111, c = 135 Å, and diffracted X-rays to 3 Å resolution. The crystallographic asymmetric unit contains one IL-20-IL-20R1-IL-20R2 complex, corresponding to a solvent content of approximately 54%. PMID:22232181

Logsdon, Naomi J; Allen, Christopher E; Rajashankar, Kanagalaghatta R; Walter, Mark R

2012-01-01

385

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

386

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.

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

2014-01-01

387

X-ray detection with Micromegas with background levels below 10-6keV-1cm-2s-1  

NASA Astrophysics Data System (ADS)

Micromegas detectors are an optimum technological choice for the detection of low energy x-rays. The low background techniques applied to these detectors yielded remarkable background reductions over the years, being the CAST experiment beneficiary of these developments. In this document we report on the latest upgrades towards further background reductions and better understanding of the detectors' response. The upgrades encompass the readout electronics, a new detector design and the implementation of a more efficient cosmic muon veto system. Background levels below 10-6keV-1cm-2s-1 have been obtained at sea level for the first time, demonstrating the feasibility of the expectations posed by IAXO, the next generation axion helioscope. Some results obtained with a set of measurements conducted in the x-ray beam of the CAST Detector Laboratory will be also presented and discussed.

Aune, S.; Aznar, F.; Calvet, D.; Dafni, T.; Diago, A.; Druillole, F.; Fanourakis, G.; Ferrer-Ribas, E.; Galán, J.; García, J. A.; Gardikiotis, A.; Garza, J. G.; Geralis, T.; Giomataris, I.; Gómez, H.; González-Díaz, D.; Herrera, D. C.; Iguaz, F. J.; Irastorza, I. G.; Jourde, D.; Luzón, G.; Mirallas, H.; Mols, J. P.; Papaevangelou, T.; Rodríguez, A.; Seguí, L.; Tomás, A.; Vafeiadis, T.; Yildiz, S. C.

2013-12-01

388

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

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

2014-01-01

389

Development and application of GASP 2.0  

NASA Technical Reports Server (NTRS)

GASP 2.0 represents a major new release of the computational fluid dynamics code in wide use by the aerospace community. The authors have spent the last two years analyzing the strengths and weaknesses of the previous version of the finite-rate chemistry, Navier Stokes solution algorithm. What has resulted is a completely redesigned computer code that offers two to four times the performance of previous versions while requiring as little as one quarter of the memory requirements. In addition to the improvements in efficiency over the original code, Version 2.0 contains many new features. A brief discussion of the improvements made to GASP, and an application using GASP 2.0 which demonstrates some of the new features are presented.

Mcgrory, W. D.; Huebner, L. D.; Slack, D. C.; Walters, R. W.

1992-01-01

390

UCbase 2.0: ultraconserved sequences database (2014 update).  

PubMed

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

391

[Adolescents in Web 2.0: risks and chances ].  

PubMed

That almost all adolescents possess an individual access to the internet and that they use it every day, lays the foundation for the improved means of self presentation and participation that are known by the notion of Web 2.0. Social networks and other interactive internet formats give rise to new risks like cyber mobbing which is the topic of three contributions. At the same time, Web 2.0 offers chances in the form of online counseling and online therapy that cater to the preferences of media-friendly target group of adolescents. PMID:24877775

Salisch, Maria von

2014-01-01

392

User's Manual Frac-Explore 2.0  

SciTech Connect

FRAC-EXPLORE 2.0, a new computer software package for oil and gas exploration using surface lineament and fracture analysis. FRAC-EXPLORE 2.0 provides a suite of tools for analyzing the characteristics and patterns of surface lineaments and fractures, as well as other surface geological features. These tools help identify priority areas of potential subsurface oil and gas traps. The package can be used in a frontier basin to initially screen the priority locations for further seismic and/or geochemical surveys. It can also be used in a mature basin to help delineate additional oil and gas reservoirs.

George, S.A.; Guo, Genliang

1999-03-09

393

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

394

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

395

Momentum spectroscopy of fragment ions of a multiply charged N2O molecule under impact of 10-keV electrons  

NASA Astrophysics Data System (ADS)

The dissociative ionization of a N2O molecule is studied at an electron energy of 10 keV using the multiple-ion-coincidence imaging technique. The complete as well as the incomplete Coulomb explosion pathways for N2O2+ and N2O3+ ions are examined and identified. The precursor-specific relative partial ionization cross sections for resulting fragment ions are obtained. It is found that about 81.8% of single ionization, 17.8% of double ionization, and about 0.4% of triple ionization of the parent molecule contribute to the total fragment ion yield. Furthermore, the relative ionic fractions for ion-pair and ion-triple formation are also determined. The kinetic energy release distributions for different coincidence channels are obtained and compared with the available data at lower energies of electron and photon impacts and with that of high-energy ion impact. From the angular correlation studies of fragment ions, it is inferred that states with bent geometries are involved for most of the fragmentation channels of N2O2+ and N2O3+ ions. The concerted and/or sequential nature of the six dissociation pathways is also assigned. No other experimental or theoretical data exist in the literature to compare with the results obtained at the considered impact energy.

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

2012-11-01

396

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

Microsoft Academic Search

Systematic calculations of stopping power (SPs) and inelastic mean free path (IMFP) values for 20–20,000 eV electrons in a group of 15 amino acids and a simple protein have been performed. The calculations are based on the dielectric response model and take into account the exchange effect between the incident electron and target electrons. The optical energy-loss functions for the 15

Zhenyu Tan; Yueyuan Xia; Mingwen Zhao; Xiangdong Liu

2006-01-01

397

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

398

Ethnography 2.0: writing with digital video  

Microsoft Academic Search

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 digital video as part of a research process and consider

M. L. White

2009-01-01

399

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.

400

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

401

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

402

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

403

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

404

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

405

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

406

Carbon Cycle 2.0: Robert Cheng and Juan Meza  

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.

Robert Cheng and Juan Meza

2010-09-01

407

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

408

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

409

20. Interior of assembly building (mold loft #2) used for ...  

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

20. Interior of assembly building (mold loft #2) used for runabout production-woodworking shop. Note counter-weighted vertical sliding doors along wall to left to move materials and boats to other room. - Barbour Boat Works, Tryon Palace Drive, New Bern, Craven County, NC

410

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

411

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

412

20. HANGAR BAY #2 FORWARD LOOKING AFT ON CENTERLINE ...  

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

20. HANGAR BAY #2 - FORWARD LOOKING AFT ON CENTERLINE - STARBOARD SIDE SHOWING CONFLAGRATION STATION, UPTAKE SPACE AND DEHUMIDIFICATION MACHINES - PORT SIDE SHOWING VARIOUS DECK WINCHES, ROLLER DOORS, HANGAR DECK PLANE CONTROL STATION AND AQUEOUS FIRE FIGHTING FOAM HOSE REELS. - U.S.S. HORNET, Puget Sound Naval Shipyard, Sinclair Inlet, Bremerton, Kitsap County, WA

413

Mobile Web 2.0, Microlearning, Intertwingularity, and Mobile Widgets  

ERIC Educational Resources Information Center

Four facets of the unfolding mobile open ecology in which OER will move are described. Web 2.0 is a platform harnessing collective intelligence where participation and pushing content are stimulated. Microlearning is different from e-learning, which replicated the classroom online; microlearning deals with relatively small learning units and…

Jaokar, Ajit

2007-01-01

414

Initial Graphics Exchange Specification (IGES) Version 2.0.  

National Technical Information Service (NTIS)

This document contains Version 2.0 of the Initial Graphics Exchange Specification, a defined format for the creation of a file which enables data found in today's commercially available CAD/CAM systems to be exchanged or archived. IGES, Version 1.0, publi...

B. Smith J. Wellington K. Brauner M. Liewald P. Kennicott

1983-01-01

415

Akeno 20 KM (2) air shower array (Akeno Branch)  

Microsoft Academic Search

As the first stage of the future huge array, the Akeno air shower array was expanded to about 20 sq. km. by adding 19 scintillation detectors of 2.25 sq m area outside the present 1 sq. km. Akeno array with a new data collection system. These detectors are spaced about 1km from each other and connected by two optical fiber

M. Teshima; H. Ohoka; Y. Matsubara; T. Hara; Y. Hatano; N. Hayashida; C. X. He; M. Honda; F. Ishikawa; K. Kamata

1985-01-01

416

Earth Satellite Program (ESP), Version 2.0.  

National Technical Information Service (NTIS)

The Earth Satellite Program (ESP) version 2.0 is a user-friendly, highly graphical, Macintosh-based program that was developed for the Air Force Milstar program to support satellite constellation and ground site terminal design studies. The computer progr...

L. M. Gaffney R. Callwood

1994-01-01

417

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

418

Medical Informatics in the Web 2.0 Era  

Microsoft Academic Search

The main role of medical and healthcare informatics is the manipulation of medical information and the dissemination of knowledge. The advent of the Web increased the pervasiveness of medical information and attracted the interest of both practitioners and patients. Web 2.0 in its turn brings people together in a more dynamic, interactive space. With new services, applications and devices, it

Iraklis Varlamis; Ioannis Apostolakis

2008-01-01

419

Carbon Cycle 2.0: Paul Alivisatos: Solar Fuels  

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.

Paul Alivisatos

2010-09-01

420

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

421

AHA! Version 2.0: More Adaptation Flexibility for Authors.  

ERIC Educational Resources Information Center

AHA! is a simple Web-based adaptive hypermedia system. Because of this simplicity it has been studied and experimented with in several research groups. This paper identifies shortcomings in AHA! and presents AHA! version 2.0 which tries to overcome the known problems with AHA! while maintaining its biggest asset: simplicity. The paper illustrates…

De Bra, Paul; Aerts, Ad; Smits, David; Stash, Natalia

422

Bewertung der Informationsqualität im Enterprise 2.0  

NASA Astrophysics Data System (ADS)

Die Entwicklungen zum Web 2.0 haben das World Wide Web (WWW) grundlegend verändert. Nachdem die meisten Nutzer im WWW zunächst "nur" nach Informationen suchten stellen Nutzer inzwischen sehr ausgiebig Informationen über sich selbst oder ihnen vertraute Themen in Blogs und Communities bereit. Facebook und Wikipedia sind zwei prominente Webseiten. Ihre Attraktivität entstammt allein den Informationen, welche die Nutzer selber zur Verfügung stellen.

Ahlheid, Sven; Graefe, Gernot; Krebs, Alexander; Schuster, Dirk

423

2.0 at AASL 2009 National Conference in Charlotte  

ERIC Educational Resources Information Center

School library media specialists are information and communication specialists who lead and model these roles in schools and at their major professional events making use of the relevant new Web 2.0 tools available to them to network, collaborate, and share. Using these tools effectively helps them become leaders in their buildings and districts.…

Valenza, Joyce Kasman

2009-01-01

424

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

425

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

426

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...

427

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...

428

Carbon Cycle 2.0: Berend Smit: Carbon Capture  

ScienceCinema

Feb. 3, 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.

Berend Smit

2010-09-01

429

ECONOMIC GROWTH ANALYSIS SYSTEM: REFERENCE MANUAL VERSION 2.0  

EPA Science Inventory

The two-volume report describes the development of and provides information needed to operate, the Economic Growth Analysis System (E-GAS) Version 2.0 model. The model will be used to project emissions inventories of volatile organic compounds (VOCs), oxides of nitrogen (NOx), a...

430

ECONOMIC GROWTH ANALYSIS SYSTEM: REFERENCE MANUAL - VERSION 2.0  

EPA Science Inventory

The two-volume report describes the development of and provides information needed to operate, the Economic Growth Analysis System (E-GAS) Version 2.0 model. he model will be used to project emissions inventories of volatile organic compounds (VOCs), oxides of nitrogen (NOx), and...

431

ECONOMIC GROWTH ANALYSIS SYSTEM: USER'S GUIDE - VERSION 2.0  

EPA Science Inventory

The two-volume report describes the development of and provides information needed to operate, the Economic Growth Analysis System (E-GAS) Version 2.0 model. he model will be used to project emissions inventories of volatile organic compounds (VOCs), oxides of nitrogen (NOx), and...

432

ECONOMIC GROWTH ANALYSIS SYSTEM: USER'S GUIDE VERSION 2.0  

EPA Science Inventory

The two-volume report describes the development of and provides information needed to operate, the Economic Growth Analysis System (E-GAS) Version 2.0 model. The model will be used to project emissions inventories of volatile organic compounds (VOCs), oxides of nitrogen (NOx), a...

433

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

434

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

435

Carbon Cycle 2.0: Paul Alivisatos: Solar Fuels  

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.

Paul Alivisatos

2010-02-16

436

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

437

Carbon Cycle 2.0: Berend Smit: Carbon Capture  

SciTech Connect

Feb. 3, 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.

Berend Smit

2010-02-16

438

From Zero to Web 2.0: Part 2  

ERIC Educational Resources Information Center

During the summer semester, the Vise Library at Cumberland University (CU) began working on its "digital makeover." It has six goals: (1) Create a more user-friendly and dynamic website; (2) Activate and maintain accounts on social networking sites such as Facebook, MySpace, and Twitter; (3) Produce a library blog that allows students, staff, and…

Woodard, Amber

2009-01-01

439

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

NASA Astrophysics Data System (ADS)

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

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

2012-10-01

440

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

NASA Astrophysics Data System (ADS)

The PILATUS detector module was characterized in the PTB laboratory at BESSY II comparing modules with 320 ?m thick and newly developed 450 ?m and 1000 ?m thick silicon sensors. Measurements were carried out over a wide energy range, in-vacuum from 1.75 keV to 8.8 keV and in air from 8 keV to 60 keV. The quantum efficiency (QE) was measured as a function of energy and the spatial resolution was measured at several photon energies both in terms of the modulation transfer function (MTF) from edge profile measurements and by directly measuring the point spread function (PSF) of a single pixel in a raster scan with a pinhole beam. Independent of the sensor thickness, the measured MTF and PSF come close to those for an ideal pixel detector with the pixel size of the PILATUS detector (172 × 172 ?m2). The measured QE follows the values predicted by calculation. Thicker sensors significantly enhance the QE of the PILATUS detectors for energies above 10 keV without impairing the spatial resolution and noise-free detection. In-vacuum operation of the PILATUS detector is possible at energies as low as 1.75 keV.

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

2013-03-01

441

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

PubMed

For the first time absolute photon mass energy-absorption coefficients of air in the energy range 3 keV to 10 keV have been measured with relative standard uncertainties less than 1%, significantly smaller than those of up to 5% assumed hitherto for calculated data. Monochromatized synchrotron radiation was used to measure both the total radiant energy by means of silicon photodiodes calibrated against a cryogenic radiometer and the fraction of radiant energy that is deposited in dry air by means of a free air ionization chamber. The measured ionization charge was converted into energy absorbed in air by calculated effective W values of photons as a function of their energy based on new measurements of the W values in dry air for electron kinetic energies between 1 keV and 7 keV, also presented in this work. The measured absorption coefficients were compared with state-of-the art calculations and found to agree within 0.7% with data calculated earlier by Hubbell at energies above 4 keV but were found to differ by values up to 2.1% at 10 keV from more recent calculations of Seltzer. PMID:17019029

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

2006-10-21

442

Mass attenuation coefficients and effective atomic numbers in phosphate glass containing Bi 2O 3, PbO and BaO at 662 keV  

NASA Astrophysics Data System (ADS)

In this work, the mass attenuation coefficients, partial interactions and the effective atomic numbers ( Zeff) of Bi 2O 3, PbO and BaO in xR mO n:(100- x)P 2O 5 (where x=30? x?70 (% by weight)) glass system have been investigated on the basis of the mixture rule at 662 keV. The total and partial interactions were calculated by WinXCom software. It has been found that the total mass attenuation coefficients of glasses increase with increasing Bi 2O 3 and PbO concentrations, due to the increasing photoelectric absorption in glass samples. However, Compton scattering gives dominant contribution to the total mass attenuation coefficients for the studied glass samples. The Zeff increases with increase in Bi 2O 3, PbO and BaO concentrations. For comparison, the Zeff of PbO glasses are comparable to that of Bi 2O 3 glasses and Zeff of both glasses are greater than BaO glasses. These results are very useful for designing radiation shielding glass and reflecting the influence of bismuth, barium, and lead content in radiation shielding phosphate glass. Besides the mentioned usefulness of the new materials, development of lead-free radiation protecting glass also leaves non-toxic impact on our environment.

Kaewkhao, J.; Limsuwan, P.

2010-07-01

443

Photon emission from 511 keV gamma rays incident on BaF 2 and LaF 3:Nd 3+ crystals using a cesium iodide photocathode detector  

NASA Astrophysics Data System (ADS)

We have studied the possibility of using BaF 2 and LaF 3 doped with Nd 3+, concentrations ranging from 0.1 to 15 mol% as efficient converters of 511 keV gamma rays. We have measured the number of photoelectrons/MeV for both crystals using a parallel-plate avalanche chamber operating with a CsI photocathode. The photocathode is sensitive to wavelengths in the range 160-220 nm. The fast component of the BaF 2 emission spectrum has peaks at roughly 175, 195 and 200 nm, and the LaF 3:Nd 3+ emission spectrum peaks at 173 nm. We measure 3.71 ± 0.04 ± 1.11 photoelectrons/MeV for the BaF 2 and 4.81 ± 0.04 ± 1.44 photoelectrons/MeV for the LaF 3:Nd 3-. The results for BaF 2 and LaF 3:Nd 3+ are consistent with measured scintillation properties of these crystals and CsI photocathode quantum efficiencies.

Kononenko, W.; Heinrich, J. G.; Lockyer, N. S.; Miller, J. M.; Woody, C.; Kwan, S.

1997-02-01

444

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

445

A cryogenic electrostatic trap for long-time storage of keV ion beams.  

PubMed

We report on the realization and operation of a fast ion beam trap of the linear electrostatic type employing liquid helium cooling to reach extremely low blackbody radiation temperature and residual gas density and, hence, long storage times of more than 5 min which are unprecedented for keV ion beams. Inside a beam pipe that can be cooled to temperatures <15 K, with 1.8 K reached in some locations, an ion beam pulse can be stored at kinetic energies of 2-20 keV between two electrostatic mirrors. Along with an overview of the cryogenic trap design, we present a measurement of the residual gas density inside the trap resulting in only 2 x 10(3) cm(-3), which for a room temperature environment corresponds to a pressure in the 10(-14) mbar range. The device, called the cryogenic trap for fast ion beams, is now being used to investigate molecules and clusters at low temperatures, but has also served as a design prototype for the cryogenic heavy-ion storage ring currently under construction at the Max-Planck Institute for Nuclear Physics. PMID:20515170

Lange, M; Froese, M; Menk, S; Varju, J; Bastert, R; Blaum, K; López-Urrutia, J R Crespo; Fellenberger, F; Grieser, M; von Hahn, R; Heber, O; Kühnel, K-U; Laux, F; Orlov, D A; Rappaport, M L; Repnow, R; Schröter, C D; Schwalm, D; Shornikov, A; Sieber, T; Toker, Y; Ullrich, J; Wolf, A; Zajfman, D

2010-05-01

446

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

447

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

448

Librarians 2.0: sowing padi in (the) SEA  

Microsoft Academic Search

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. Design\\/methodology\\/approach – Libraries

Ivan Chew

2009-01-01

449

Evaluation and Application of MIDAS v2.0  

Microsoft Academic Search

Version 2.0 of the Man-Machine Design and Analysis System (MIDAS) was released in 2001. It provides tools to describe an operating environment, mission, and equipment. User-defined goals, procedures, and knowledge interact with and are modified by models of perception, memory, situation awareness, and attention and constrained by the environment. Output of simulations that demonstrate or evaluate new capabilities or answer

Sandra G. Hart; K. Michael Dalal; Raytheon STX

450

Evaluation and Application of MIDAS v2.0  

Microsoft Academic Search

ABSTRACT Version 2.0 of the Man-Machine Design and Analysis System (MIDAS) was released in 2001. It provides tools to describe an operating environment, mission, and equipment. User-defined goals, procedures, and knowledge,interact with and are modified by models of perception, memory, situation awareness, and attention and constrained by the environment. Output of simulations that demonstrate,or evaluate new capabilities or answer questions

Sandra G. Hart; David Dahn; Adolph Atencio; K. Michael Dalal

451

MESOI2.0. Puff Dispersion Model W/Deposition  

SciTech Connect

MESOI Version 2.0 is an interactive Lagrangian puff model for estimating the transport, diffusion, deposition, and decay of effluents released to the atmosphere. The model is capable of treating simultaneous releases from as many as four release points, which may be either at elevated locations or at ground-level. The puffs are advected by a horizontal wind field that is defined in three dimensions. The wind field may be adjusted for expected topographic effects. The concentration distribution within the puffs is initially assumed to be Gaussian in the horizontal and vertical directions. However, the vertical concentration distribution is modified by assuming reflection at the ground and the top of the atmospheric mixing layer. Material is deposited on the surface using a source depletion, dry deposition model and a washout coefficient model. The model also treats the decay of a primary effluent species and the ingrowth and decay of a single daughter species using a first-order decay process. MESOI2.0 is based on the earlier MESOI Versions 1.0 and 1.1 and the MESODIF model prepared originally by Start and Wendell for the National Reactor Testing Station. The main reasons for Version 2.0 were to incorporate the processes that alter and deplete effluents and to provide a more realistic treatment of the wind field that transports the effluents. MESOI2.0 uses routines from the proprietary CalComp graphics library to obtain graphic output; these routines are not included and will have to be replaced with suitable local alternatives.

Ramsdell, J.V.; Athey, G. F.; Glantz, C. S. [Pacific Northwest Lab., Richland, WA, (United States)

1992-02-03

452

A CMOS image sensor with 2.0-e  

Microsoft Academic Search

A low noise CMOS image sensor without degradation of saturation performance has been developed by using column amplifiers of the gains of about 1.0 with a lateral overflow integration capacitor technology. The 1\\/4-inch, SVGA CMOS image sensor has achieved 0.98 column readout gain, 100-¿V\\/e- conversion gain, 2.0-e- total random noise, 0.5-e- in readout circuits, 110,000-e- full well capacity and 95-dB

Takahiro Kohara; Woonghee Lee; Koichi Mizobuchi; Shigetoshi Sugawa

2010-01-01

453

Formation, structure, and dissociation dynamics of CO2q+ (q?3) ions due to impact of 12-keV electrons  

NASA Astrophysics Data System (ADS)

The electron-impact multiple ionization and subsequent dissociation of CO2 is studied for 12-keV electron energy using a linear time-of-flight mass spectrometer coupled with a multihit, position-sensitive detector. The complete as well as incomplete Coulomb explosion pathways for CO22+ and CO23+ ions are examined and identified. The kinetic energy release distributions for these precursor ions are obtained. The experimental kinetic energy release values for the complete Coulomb fragmentation channels are found to be overestimated by those calculated from the Coulomb explosion model. From the angular correlation studies, it is inferred that bent geometrical states are involved for most of the fragmentation channels of CO22+ and CO23+ ions. The concerted and/or sequential nature of all the dissociation pathways is also assigned. This study provides the first results on energetics associated with the charge separation in dissociative ionization of CO2 under the impact of electrons at a subrelativistic energy.

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

2012-04-01

454

Comparison of Cervical Range of Motion and Cervical FRR between Computer Users in Their Early and Late 20s in Korea  

PubMed Central

[Purpose] This study compared the cervical range of motion and cervical FRR between computer users in their early and late 20s in Korea. [Subjects] Eleven male and 7 female computer users in their early 20s and 10 male and 6 female computer users in their late 20s participated in this study. [Methods] All cervical ROM measurements were taken with a Cervical Range of Motion Instrument. Electromyographic (EMG) data were obtained for analyzing the FR ratio. [Results] Cervical extension, right and left lateral flexion, and right and left rotation in the late 20s computer users were significantly lower compared with the cervical motions in the early 20s computer users. The cervical FRR in the late 20s computer users was significantly lower compared with the cervical FRR in the early 20s computer users. [Conclusion] This study was conducted to be prepared that the possibility for young computer generations in Korea could easily develop chronic neck pain.

Yoo, Won-gyu

2014-01-01

455

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

456

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.

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

2010-01-01

457

Learning with Web 2.0: Social Technology and Discursive Psychology  

ERIC Educational Resources Information Center

Recent years have seen the rise of Internet technologies which facilitate activities that are, above all, social and participatory, allowing children and adults to create and share their own content, and to communicate in a wide range of forums. Correspondingly, there has been great popular and expert interest in the potential of Web 2.0

Friesen, Norm; Lowe, Shannon

2012-01-01

458

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

459

Effect of ion implantation on fracture stress of Al2O3  

Microsoft Academic Search

Effects of ion implantation and subsequent thermal annealing on the fracture stress of single-crystalline alpha-Al2O3 have been investigated for 400 keV N and 300 keV Ni ions. Upon N or Ni implantation, the flexural strength of a specimen 7 × 25 × 1 mm3 in size increased by 20 to 60% in the ion dose range from 1 × 1015

T. Hioki; A. Itoh; S. Noda; H. Doi; J. Kawamoto; O. Kamigaito

1985-01-01

460

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

NASA Astrophysics Data System (ADS)

We report the discovery of water maser emission in five active galactic nuclei (AGNs) 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 ? (0.3" radio and 1.3" 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% (5 out of 41) among Seyfert 2 and LINER systems with 10,000 km s-12-10 keV) and total isotropic water maser luminosity, L2-10~L0.5+/-0.1H2O, 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.

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

2006-11-01

461

The Isotope Effect to the IR Emissions of CO and CO2 produced by 15 keV H3+ irradiation of H2O (D2O)/ CO, CO2, CH4 or CH3OH icy mixtures.  

NASA Astrophysics Data System (ADS)

Simulation of ices covered astronomical surfaces irradiated by 15 keV H3+. We have measured the particle irradiation of interstellar icy materials such as H2O mixed with CH4, CO, CO2, and CH3OH resulting the synthesis of CO and CO2. The technique used to identify and quantify the synthesized species has been infrared spectroscopy. Irradiation of pure water ice produces OH and no CO and CO2. Irradiation of pure CH4 causes the formation of CH4 and C2H6, but no CO and CO21. On the other hand, irradiation of pure CH3OH ice produces CO and CO22. Tow IR emissions of CO2 (2339 cm-1) and CO (2136 cm-1) produced by ion irradiation of all icy mixtures are compared with H2O abundance. The experimental results are discussed with a view to the relevance they could have in planetary environments such as icy moons in the external solar system.

Lee, C.; Ip, W.; Lin, C.; Chou, C.

2008-12-01

462

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.