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open access

The Cosmic Dance of Obama-Raja on Newsweek

Description: Article discussing an image that appears on the front cover of Newsweek magazine depicting President Barack Obama.
Date: November 2010
Creator: Jain, Pankaj
Partner: UNT College of Public Affairs and Community Service
open access

The Use of Genetics for the Management of a Recovering Population: Temporal Assessment of Migratory Peregrine Falcons in North America

Description: Article on the use of genetics for the management of a recovering population and a temporal assessment of migratory peregrine falcons in North America.
Date: November 18, 2010
Creator: Johnson, Jeff A.; Talbot, Sandra Looman; Sage, George K.; Burnham, Kurt K.; Brown, Joseph W.; Maechtle, Tom L. et al.
Partner: UNT College of Arts and Sciences
open access

Production of high brightness H- beam by charge exchange of hydrogen atom beam in sodium jet

Description: Production of H{sup -} beam for accelerators applications by charge exchange of high brightness hydrogen neutral beam in a sodium jet cell is experimentally studied in joint BNL-BINP experiment. In the experiment, a hydrogen-neutral beam with 3-6 keV energy, equivalent current up to 5 A and 200 microsecond pulse duration is used. The atomic beam is produced by charge exchange of a proton beam in a pulsed hydrogen target. Formation of the proton beam is performed in an ion source by four-electro… more
Date: November 16, 2010
Creator: Davydenko, V.; Zelenski, A.; Ivanov, A. & Kolmogorov, A.
Partner: UNT Libraries Government Documents Department
open access

Fighting Fire with Fire: Modeling the Datacenter-Scale Effects of Targeted Superlattice Thermal Management

Description: Local thermal hot-spots in microprocessors lead to worst case provisioning of global cooling resources, especially in large-scale systems. However, efficiency of cooling solutions degrade non-linearly with supply temperature, resulting in high power consumption and cost in cooling - 50 {approx} 100% of IT power. Recent advances in active cooling techniques have shown on-chip thermoelectric coolers (TECs) to be very efficient at selectively eliminating small hot-spots, where applying current to … more
Date: November 11, 2010
Creator: Biswas, S; Tiwari, M; Theogarajan, L; Sherwood, T P & Chong, F T
Partner: UNT Libraries Government Documents Department
open access

StralSV: assessment of sequence variability within similar 3D structures and application to polio RNA-dependent RNA polymerase

Description: Most of the currently used methods for protein function prediction rely on sequence-based comparisons between a query protein and those for which a functional annotation is provided. A serious limitation of sequence similarity-based approaches for identifying residue conservation among proteins is the low confidence in assigning residue-residue correspondences among proteins when the level of sequence identity between the compared proteins is poor. Multiple sequence alignment methods are more s… more
Date: November 29, 2010
Creator: Zemla, A; Lang, D; Kostova, T; Andino, R & Zhou, C
Partner: UNT Libraries Government Documents Department
open access

Correlation between structure and electrical transport in ion-irradiated graphene grown on Cu foils

Description: Graphene grown by chemical vapor deposition and supported on SiO2 and sapphire substrates was studied following controlled introduction of defects induced by 35 keV carbon ion irradiation. Changes in Raman spectra following fluences ranging from 1012 cm-2 to 1015 cm-2 indicate that the structure of graphene evolves from a highly-ordered layer, to a patchwork of disordered domains, to an essentially amorphous film. These structural changes result in a dramatic decrease in the Hall mobility by or… more
Date: November 4, 2010
Creator: Buchowicz, G.; Stone, P. R.; Robinson, J. T.; Cress, C. D.; Beeman, J. W. & Dubon, O. D.
Partner: UNT Libraries Government Documents Department
open access

High Rate Deposition of High Quality ZnO:Al by Filtered Cathodic Arc

Description: High quality ZnO:Al (AZO) thin films were prepared on glass substrates by direct current filtered cathodic arc deposition. Substrate temperature was varied from room temperature to 425oC, and samples were grown with and without the assistance of low power oxygen plasma (75W). For each growth condition, at least 3 samples were grown to give a statistical look at the effect of the growth environment on the film properties and to explore the reproducibility of the technique. Growth rate was in the… more
Date: November 18, 2010
Creator: Mendelsberg, Rueben J.; Lim, S.H.N.; Milliron, D.J. & Anders, Andre
Partner: UNT Libraries Government Documents Department
open access

Ecological outcomes and evaluation of success in passively restored southeastern depressional wetlands.

Description: Abstract: Depressional wetlands may be restored passively by disrupting prior drainage to recover original hydrology and relying on natural revegetation. Restored hydrology selects for wetland vegetation; however, depression geomorphology constrains the achievable hydroperiod, and plant communities are influenced by hydroperiod and available species pools. Such constraints can complicate assessments of restoration success. Sixteen drained depressions in South Carolina, USA, were restored experi… more
Date: November 1, 2010
Creator: De Steven, Diane; Sharitz, Rebecca R. & Barton, Christopher, D.
Partner: UNT Libraries Government Documents Department
open access

Direct Comparison of the X-Ray Emission and Absorption of Cerium Oxide

Description: Bremstrahlung Isochromat Spectroscopy (BIS). The XES spectra were collected using a Specs electron gun for the excitation and the XES 350 grating monochromator and channel plate system from Scienta as the photon detection. Spectra were collected in 'normal mode,' where the electron gun kinetic energy (KE) and the energy position of the center of the channel plate were both fixed and the energy distribution in the photon (hv) spectrum was derived from the intensities distributed across the chann… more
Date: November 24, 2010
Creator: Tobin, J G; Yu, S W; Chung, B W; Waddill, G D & Denlinger, J D
Partner: UNT Libraries Government Documents Department
open access

ESTABLISHING FINAL END STATE FOR A RETIRED NUCLEAR WEAPONS PRODUCTION REACTOR; COLLABORATION BETWEEN STAKEHOLDERS, REGULATORS, AND THE FEDERAL GOVERNMENT - 11052

Description: The Savannah River Site (SRS) is a 310-square-mile United States Department of Energy nuclear facility located along the Savannah River (SRS) near Aiken, South Carolina. Nuclear weapons material production began in the early 1950s, utilizing five production reactors. In the early 1990s all SRS production reactor operations were terminated. The first reactor closure end state declaration was recently institutionalized in a Comprehensive Environmental Response and Compensation and Liability Act (… more
Date: November 17, 2010
Creator: Bergren, C.; Flora, M. & Belencan, H.
Partner: UNT Libraries Government Documents Department
open access

B physics at CDF - the Beauty of hadron collisions

Description: The CDF experiment at the Tevatron p{bar p} collider established that extensive and detailed exploration of the b-quark dynamics is possible in hadron collisions, with results competitive and supplementary to those from e{sup +}e{sup -} colliders. This provides an unique, rich, and highly rewarding program that is currently reaching full maturity. I report a few recent world-leading results on rare decays, CP-violation in B{sub s}{sup 0} mixing, and b {yields} s penguin decays.
Date: November 1, 2010
Creator: Tonelli, Diego
Partner: UNT Libraries Government Documents Department
open access

The Effect of Degraded Digital Instrumentation and Control systems on Human-system Interfaces and Operator Performance

Description: Integrated digital instrumentation and control (I&C) systems in new and advanced nuclear power plants (NPPs) will support operators in monitoring and controlling the plants. Even though digital systems typically are expected to be reliable, their potential for degradation or failure significantly could affect the operators performance and, consequently, jeopardize plant safety. This U.S. Nuclear Regulatory Commission (NRC) research investigated the effects of degraded I&C systems on hum… more
Date: November 7, 2010
Creator: Ohara, J. M.; Gunther, B.; Martinez-Guridi, G. (BNL); Xing, J. & Barnes, V. (NRC)
Partner: UNT Libraries Government Documents Department
open access

Comparative Gamma Spectroscopy with SrI2(Eu), GYGAG(Ce) and Bi-loaded Plastic Scintillators

Description: We are developing new scintillator materials that offer potential for high resolution gamma ray spectroscopy at low cost. Single crystal SrI{sub 2}(Eu) offers {approx}3% resolution at 662 keV, in sizes of {approx}1 in{sup 3}. We have developed ceramics processing technology allowing us to achieve cubic inch scale transparent ceramic scintillators offering gamma spectroscopy performance superior to NaI(Tl). We fabricated a bismuth-loaded plastic scintillator that demonstrates energy resolution o… more
Date: November 19, 2010
Creator: Cherepy, N J
Partner: UNT Libraries Government Documents Department
open access

Bottom Production from Fixed-Target to Large Hadron Collider Energies

Description: We present a state-of-the-art compilation of the existing bottom production cross sections in elementary collisions, from fixed-target to collider experiments. We then discuss the theoretical uncertainties on the total and differential bottom cross sections in the FONLL approach. In particular, we show total cross sections and kinematical distributions of the bottom hadrons and their decays: B {yields} e/{mu}X, B {yields} D {yields} e/{mu}, and B {yields} J/{psi}X. After seeing that the calcula… more
Date: November 30, 2010
Creator: Nelson, R. E.; Vogt, R.; Lourenco, C. & Wohri, H. K.
Partner: UNT Libraries Government Documents Department
open access

On fluid flow in a heterogeneous medium under nonisothermal conditions

Description: An asymptotic technique, valid in the presence of smoothly-varying heterogeneity, provides explicit expressions for the velocity of a propagating pressure and temperature disturbance. The governing equations contain nonlinear terms due to the presence of temperature-dependent coefficients and due to the advection of fluids with differing temperatures. Two cases give well-defined expressions in terms of the parameters of the porous medium: the uncoupled propagation of a pressure disturbance and … more
Date: November 1, 2010
Creator: D.W., Vasco
Partner: UNT Libraries Government Documents Department
open access

Monolithic Active Pixel Matrix with Binary Counters (MAMBO) ASIC

Description: Monolithic Active Matrix with Binary Counters (MAMBO) is a counting ASIC designed for detecting and measuring low energy X-rays from 6-12 keV. Each pixel contains analogue functionality implemented with a charge preamplifier, CR-RC{sup 2} shaper and a baseline restorer. It also contains a window comparator which can be trimmed by 4 bit DACs to remove systematic offsets. The hits are registered by a 12 bit ripple counter which is reconfigured as a shift register to serially output the data from … more
Date: November 1, 2010
Creator: Khalid, Farah F.; Deptuch, Grzegorz; Shenai, Alpana & Yarema, Raymond J.
Partner: UNT Libraries Government Documents Department
open access

Measurement of the W boson helicity in top quark decays using 5.4 fb$^{\boldsymbol{-1}}$ of $\boldsymbol{p\bar{p}}$ collision data

Description: We present a measurement of the helicity of the W boson produced in top quark decays using t{bar t} decays in the {ell}+jets and dilepton final states selected from a sample of 5.4 fb{sup -1} of collisions recorded using the D0 detector at the Fermilab Tevatron p{bar p} collider. We measure the fractions of longitudinal and right-handed W bosons to be f{sub 0} = 0.669 {+-} 0.102 [{+-}0.078 (stat.) {+-} 0.065 (syst.)] and f{sub +} = 0.023 {+-} 0.053 [{+-}0.041 (stat.){+-}0.034 (syst.)], respecti… more
Date: November 1, 2010
Creator: Abazov, Victor Mukhamedovich; Abbott, Braden Keim; Acharya, Bannanje Sripath; Adams, Mark Raymond; Adams, Todd; Alexeev, Guennadi D. et al.
Partner: UNT Libraries Government Documents Department
open access

Probing the eV-Mass Range for Solar Axions with CAST

Description: The CERN Axion Solar Telescope (CAST) is searching for solar axions which could be produced in the core of the Sun via the so-called Primakoff effect. Not only would these hypothetical particles solve the strong CP problem, but they are also one of the favored candidates for dark matter. In order to look for axions originating from the Sun, CAST uses a decommissioned LHC prototype magnet. In its 10 m long magnetic field region of 9 Tesla, axions could be reconverted into X-ray photons. Differen… more
Date: November 11, 2010
Creator: Vogel, J K; Pivovaroff, M J; Soufli, R; van Bibber, K & CAST, C
Partner: UNT Libraries Government Documents Department
open access

Neutron Capture Gamma-Ray Libraries for Nuclear Applications

Description: The neutron capture reaction is useful in identifying and analyzing the gamma-ray spectrum from an unknown assembly as it gives unambiguous information on its composition. this can be done passively or actively where an external neutron source is used to probe an unknown assembly. There are known capture gamma-ray data gaps in the ENDF libraries used by transport codes for various nuclear applications. The Evaluated Gamma-ray Activation file (EGAF) is a new thermal neutron capture database of d… more
Date: November 4, 2010
Creator: Sleaford, B. W.; Firestone, R. B.; Summers, N.; Escher, J.; Hurst, A.; Krticka, M. et al.
Partner: UNT Libraries Government Documents Department
open access

Nanostructured LaF{sub 3}:Ce Quantum Dot Nuclear Radiation Detector

Description: Many radioactive isotopes have low energy X-rays and high energy gamma rays of interest for detection. The goal of the work presented was to demonstrate the possibility of measuring both low-energy X-rays and relatively high-energy gamma rays simultaneously using the nano-structured lanthanum bromide, lanthanum fluoride, or cerium bromide. The key accomplishments of the project was the building and acquisition of the LaF3:Ce nanocomposite detectors. Nanocomposite detectors are sensitive to {gam… more
Date: November 1, 2010
Creator: Guss, P., Guise, R., Reed, M., Mukhopadhyay, S., Yuan, D.
Partner: UNT Libraries Government Documents Department
open access

J/psi production and absorption in p + A and d+Au collisions

Description: The level of 'anomalous' charmonium suppression in high-energy heavy-ion collisions and its interpretation as a signal of quark-gluon plasma formation requires a robust understanding of charmonium production and absorption in proton-nucleus collisions. In a previous study we have shown that, contrary to common belief, the so-called J/{psi} 'absorption cross section', {sigma}{sub abs}{sup J/{psi}}, is not a 'universal constant' but, rather, an effective parameter that depends very significantly … more
Date: November 30, 2010
Creator: Vogt, R; Lourenco, C & Woehri, H
Partner: UNT Libraries Government Documents Department
open access

DESIGN OF THE ITER IN-VESSEL COILS

Description: The ITER project is considering the inclusion of two sets of in-vessel coils, one to mitigate the effect of Edge Localized Modes (ELMs) and another to provide vertical stabilization (VS). The in-vessel location (behind the blanket shield modules, mounted to the vacuum vessel inner wall) presents special challenges in terms of nuclear radiation (~3000 MGy) and temperature (100oC vessel during operations, 200oC during bakeout). Mineral insulated conductors are well suited to this environment but … more
Date: November 27, 2010
Creator: Neumeyer, C; Bryant, L; Chrzanowski, J; Feder, R; Gomez, M; Heitzenroeder, P et al.
Partner: UNT Libraries Government Documents Department
open access

Development of Compton Radiography Diagnostics for Inertial Confinement Fusion Implosions

Description: An important diagnostic tool for inertial confinement fusion will be time-resolved radiographic imaging of the dense cold fuel surrounding the hot spot. The measurement technique is based on point-projection radiography at photon energies from 60-200 keV where the Compton effect is the dominant contributor to the opacity of the fuel or pusher. We have successfully applied this novel Compton Radiography technique to the study of the final compression of directly driven plastic capsules at the OM… more
Date: November 16, 2010
Creator: Tommasini, R.; Hatchett, S. P.; Hey, D. S.; Izumi, N.; Koch, J. A.; Landen, O. L. et al.
Partner: UNT Libraries Government Documents Department
open access

Numerical Tests of the Improved Fermilab Action

Description: Recently, the Fermilab heavy-quark action was extended to include dimension-six and -seven operators in order to reduce the discretization errors. In this talk, we present results of the first numerical simulations with this action (the OK action), where we study the masses of the quarkonium and heavy-light systems. We calculate combinations of masses designed to test improvement and compare results obtained with the OK action to their counterparts obtained with the clover action. Our prelimina… more
Date: November 1, 2010
Creator: Detar, C.; Kronfeld, A.S. & Oktay, M.B.
Partner: UNT Libraries Government Documents Department
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