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Z' Coupling Information From LHeC

Description: No Description Available.
Date: April 4, 2008
Creator: Rizzo, Thomas G.
Partner: UNT Libraries Government Documents Department
open access

R. Bruce Merrifield and Solid-Phase Peptide Synthesis: A Historical Assessment

Description: Bruce Merrifield, trained as a biochemist, had to address three major challenges related to the development and acceptance of solid-phase peptide synthesis (SPPS). The challenges were (1) to reduce the concept of peptide synthesis on a insoluble support to practice, (2) overcome the resistance of synthetic chemists to this novel approach, and (3) establish that a biochemist had the scientific credentials to effect the proposed revolutionary change in chemical synthesis. How these challenges wer… more
Date: December 4, 2007
Creator: Mitchell, A R
Partner: UNT Libraries Government Documents Department
open access

Resonant Soft X-Ray Contrast Variation Methods as Composition-Specific Probes of Thin Polymer Film Structure

Description: We have developed complementary soft x-ray scattering and reflectometry techniques that allow for the morphological analysis of thin polymer films without resorting to chemical modification or isotopic 2 labeling. With these techniques, we achieve significant, x-ray energy-dependent contrast between carbon atoms in different chemical environments using soft x-ray resonance at the carbon edge. Because carbon-containing samples absorb strongly in this region, the scattering length density depends… more
Date: April 4, 2008
Creator: Welch, Cynthia; Welch, Cynthia F.; Hjelm, Rex P.; Mang, Joseph T.; Hawley, Marilyn E.; Wrobleski, Debra A. et al.
Partner: UNT Libraries Government Documents Department
open access

Breaking the Curse of Cardinality on Bitmap Indexes

Description: Bitmap indexes are known to be efficient for ad-hoc range queries that are common in data warehousing and scientific applications. However, they suffer from the curse of cardinality, that is, their efficiency deteriorates as attribute cardinalities increase. A number of strategies have been proposed, but none of them addresses the problem adequately. In this paper, we propose a novel binned bitmap index that greatly reduces the cost to answer queries, and therefore breaks the curse of cardinali… more
Date: April 4, 2008
Creator: Wu, Kesheng; Wu, Kesheng; Stockinger, Kurt & Shoshani, Arie
Partner: UNT Libraries Government Documents Department
open access

Radioactive Elements in the Standard Atomic Weights Table.

Description: In the 1949 Report of the Atomic Weights Commission, a series of new elements were added to the Atomic Weights Table. Since these elements had been produced in the laboratory and were not discovered in nature, the atomic weight value of these artificial products would depend upon the production method. Since atomic weight is a property of an element as it occurs in nature, it would be incorrect to assign an atomic weight value to that element. As a result of that discussion, the Commission deci… more
Date: August 4, 2007
Creator: Holden, N. E.
Partner: UNT Libraries Government Documents Department
open access

Measurement of D^0-\bar{D^0} Mixing From a Time-Dependent Amplitude Analysis of D^0\ -> K^+\pi^-\pi0 Decays

Description: The authors present evidence of D{sup 0}-{bar D}{sup 0} mixing using a time-dependent amplitude analysis of the decay D{sup 0} {yields} K{sup +}{pi}{sup -}{pi}{sup 0} in a data sample of 384 fb{sup -1} collected with the BABAR detector at the PEP-II e{sup +}e{sup -} collider at SLAC. Assuming CP conservation, they measure the mixing parameters x{prime}{sub K{pi}{pi}{sup 0}} = [2.61{sub -0.68}{sup +0.57}(stat.) {+-} 0.39(syst.)]%, y{prime}{sub K{pi}{pi}{sup 0}} = [-0.06{sub -0.64}{sup +0.55}(sta… more
Date: August 4, 2008
Creator: Aubert, Bernard; Bona, M.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E. et al.
Partner: UNT Libraries Government Documents Department
open access

INVESTIGATION OF THE PRESENCE OF DRUGSTORE BEETLES WITHIN CELOTEX ASSEMBLIES IN RADIOACTIVE MATERIAL PACKAGINGS

Description: During normal operations at the Department of Energy's Hanford Site in Hanford, WA, drugstore beetles, (Stegobium paniceum (L.) Coleoptera: Anobiidae), were found within the fiberboard subassemblies of two 9975 Shipping Packages. Initial indications were that the beetles were feeding on the Celotex{trademark} assemblies within the package. Celotex{trademark} fiberboard is used in numerous radioactive material packages serving as both a thermal insulator and an impact absorber for both normal co… more
Date: June 4, 2008
Creator: Loftin, B & Glenn Abramczyk, G
Partner: UNT Libraries Government Documents Department
open access

Ferromagnetism in GaN: Gd: A density functional theory study

Description: First principle calculations of the electronic structure and magnetic interaction of GaN:Gd have been performed within the Generalized Gradient Approximation (GGA) of the density functional theory (DFT) with the on-site Coulomb energy U taken into account (also referred to as GGA+U). The ferromagnetic p-d coupling is found to be over two orders of magnitude larger than the s-d exchange coupling. The experimental colossal magnetic moments and room temperature ferromagnetism in GaN:Gd reported re… more
Date: February 4, 2008
Creator: Stevenson, Cynthia & Stevenson, Cynthia
Partner: UNT Libraries Government Documents Department
open access

Measurement of the B to Xs gammaBranching Fraction and Photon Energy Spectrum usingthe Recoil Method

Description: We present a measurement of the branching fraction and photon energy spectrum for the decay B {yields} X{sub s}{gamma} using data from the BABAR experiment. The data sample corresponds to an integrated luminosity of 210 fb{sup -1}, from which approximately 680,000 B{bar B} events are tagged by a fully reconstructed hadronic decay of one of the B mesons. In the decay of the second B meson, an isolated high-energy photon is identified. We measure {Beta}(B {yields} X{sub s}{gamma}) = (3.66 {+-} 0.… more
Date: December 4, 2007
Creator: Aubert, B.
Partner: UNT Libraries Government Documents Department
open access

Recovering the Elemental Composition of Comet Wild 2 Dust in Five Stardust Impact Tracks and Terminal Particles in Aerogel

Description: The elemental (non-volatile) composition of five Stardust impact tracks and terminal particles left from capture of Comet 81P/Wild 2 dust were mapped in a synchrotron x-ray scanning microprobe with full fluorescence spectra at each pixel. Because aerogel includes background levels of several elements of interest, we employ a novel 'dual threshold' approach to discriminate against background contaminants: an upper threshold, above which a spectrum contains cometary material plus aerogel and a lo… more
Date: January 4, 2007
Creator: Ishii, H. A.; Brennan, S.; Bradley, J. P.; Luening, K.; Ignatyev, K. & Pianetta, P.
Partner: UNT Libraries Government Documents Department
open access

Electrons in a positive-ion beam with solenoid or quadrupole magnetic transport

Description: The High Current Experiment (HCX) is used to study beam transport and accumulation of electrons in quadrupole magnets and the Neutralized Drift-Compression Experiment (NDCX) to study beam transport through and accumulation of electrons in magnetic solenoids. We find that both clearing and suppressor electrodes perform as intended, enabling electron cloud densities to be minimized. Then, the measured beam envelopes in both quadrupoles and solenoids agree with simulations, indicating that theoret… more
Date: June 4, 2007
Creator: Molvik, A. W.; Kireeff Covo, M.; Cohen, R.; Coleman, J.; Sharp, W.; Bieniosek, F. et al.
Partner: UNT Libraries Government Documents Department
open access

Generalization of the ERIT principle and method.

Description: The paper describes the generalization of the method to produce secondary particles with a low-energy and low-intensity primary beam circulating in a Storage Ring with the Emittance-Recovery by Internal-Target (ERIT).
Date: November 4, 2007
Creator: Ruggiero, A. G.
Partner: UNT Libraries Government Documents Department
open access

Electron-Cloud Build-up in the FNAL Main Injector

Description: We present a summary on ongoing simulation results for the electron-cloud buildup in the context of the proposed FNAL Main Injector (MI) intensity upgrade [1] in a fieldfree region at the location of the RFA electron detector [2]. By combining our simulated results for the electron flux at the vacuum chamber wall with the corresponding measurements obtained with the RFA we infer that the peak secondary electron yield (SEY) {delta}{sub max} is {approx}> 1.4, and the average electron density i… more
Date: June 4, 2007
Creator: Furman, M. A.
Partner: UNT Libraries Government Documents Department
open access

Development of an Immersed Boundary Method to Resolve Complex Terrain in the Weather Research and Forecasting Model

Description: Flow and dispersion processes in urban areas are profoundly influenced by the presence of buildings which divert mean flow, affect surface heating and cooling, and alter the structure of turbulence in the lower atmosphere. Accurate prediction of velocity, temperature, and turbulent kinetic energy fields are necessary for determining the transport and dispersion of scalars. Correct predictions of scalar concentrations are vital in densely populated urban areas where they are used to aid in emerg… more
Date: September 4, 2007
Creator: Lunquist, K A; Chow, F K; Lundquist, J K & Mirocha, J D
Partner: UNT Libraries Government Documents Department
open access

Measurements of {\cal B}(\overline{B}^0 \to \Lambda_{c}^{+} \overline{p}) and {\cal B}(B^- \to \Lambda_{c}^{+} \overline{p} \pi^-) and Studies of \Lambda_{c}^{+}\pi^- Resonances

Description: The authors present an investigation of the decays {bar B}{sup 0} {yields} {Lambda}{sub c}{sup +}{bar p} and B{sup -} {yields} {Lambda}{sub c}{sup +}{bar p}{pi}{sup -} based on 383 x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} decays recorded with the BABAR detector. They measure the branching fractions of these decays; their ratio is {Beta}(B{sup -} {yields} {Lambda}{sub c}{sup +}{bar p}{pi}{sup -})/{Beta}({bar B}{sup 0} {yields} {Lambda}{sub c}{sup +}{bar p}) = 15.4 {+-} 1.8 {+-} 0.3. The B{sup… more
Date: August 4, 2008
Creator: Collaboration, The BABAR & Aubert, B.
Partner: UNT Libraries Government Documents Department
open access

Isochoric Implosions for Fast Ignition

Description: Various gain models have shown the potentially great advantages of Fast Ignition (FI) Inertial Confinement Fusion (ICF) over its conventional hot spot ignition counterpart [e.g., S. Atzeni, Phys. Plasmas 6, 3316 (1999); M. Tabak et al., Fusion Sci. & Technology 49, 254 (2006)]. These gain models, however, all assume nearly uniform-density fuel assemblies. In contrast, conventional ICF implosions yield hollowed fuel assemblies with a high-density shell of fuel surrounding a low-density, high-pre… more
Date: April 4, 2007
Creator: Clark, D S & Tabak, M
Partner: UNT Libraries Government Documents Department
open access

Laser heating of solid matter by light pressure-driven shocks

Description: Heating by irradiation of a solid surface in vacuum with 5 x 10{sup 20} W cm{sup -2}, 0.8 ps, 1.05 {micro}m wavelength laser light is studied by x-ray spectroscopy of the K-shell emission from thin layers of Ni, Mo and V. A surface layer is heated to {approx} 5 keV with an axial temperature gradient of 0.6 {micro}m scale length. Images of Ni Ly{sub {alpha}} show the hot region has a {approx} 25 {micro}m diameter, much smaller than {approx} 70 {micro}m region of K{sub {alpha}} emission. 2D parti… more
Date: May 4, 2007
Creator: Akli, K.; Hansen, S. B.; Kemp, A. J.; Freeman, R. R.; Beg, F. N.; Clark, D. et al.
Partner: UNT Libraries Government Documents Department
open access

FINAL FRONTIER AT HANFORD TACKLING THE CENTRAL PLATEAU

Description: The large land area in the center of the vast Department of Energy (DOE) Hanford Site in southeast Washington State is known as 'the plateau'--aptly named because its surface elevations are 250-300 feet above the groundwater table. By contrast, areas on the 585-square mile Site that border the Columbia River sit just 30-80 feet above the water table. The Central Plateau, which covers an ellipse of approximately 70 square miles, contains Hanford's radiochemical reprocessing areas--the 200 East a… more
Date: March 4, 2008
Creator: MS, GERBER
Partner: UNT Libraries Government Documents Department
open access

Time-Dependent and Time-Integrated Angular Analysis of B -> phi Ks pi0 and B -> phi K+ pi-

Description: We perform a time-dependent and time-integrated angular analysis of the B{sup 0} {yields} {psi}K*(892){sup 0}, {psi}K*{sub 2}(1430{sup 0}), and {psi}(K{pi}){sub S-wave}{sup 0} decays with the final sample of about 465 million B{bar B} pairs recorded with the BABAR detector. Overall, twelve parameters are measured for the vector-vector decay, nine parameters for the vector-tensor decay, and three parameters for the vector-scalar decay, including the branching fractions, CP-violation parameters, … more
Date: August 4, 2008
Creator: Aubert, B.; Bona, M.; Karyotakis, Y; Lees, J.P. & Poireau, V.
Partner: UNT Libraries Government Documents Department
open access

Measuring Regional Changes in the Diastolic Deformation of the Left Ventricle of SHR Rats Using microPET Technology and Hyperelastic Warping

Description: The objective of this research was to assess applicability of a technique known as hyperelastic warping for the measurement of local strains in the left ventricle (LV) directly from microPET image data sets. The technique uses differences in image intensities between template (reference) and target (loaded) image data sets to generate a body force that deforms a finite element (FE) representation of the template so that it registers with the target images. For validation, the template image was… more
Date: April 4, 2008
Creator: Gullberg, Grant T; Veress , Alexander I.; Weiss, Jeffrey A.; Huesman, Ronald H.; Reutter, Bryan W.; Taylor , Scott E. et al.
Partner: UNT Libraries Government Documents Department
open access

Direct Observation of the Kinetically Relevant Site of CO Hydrogenation on Supported Ru Catalyst at 700 K by Time-Resolved FT-IR Spectroscopy

Description: Time-resolved FT-IR spectra of carbon monoxide hydrogenation over alumina-supported ruthenium particles were recorded on themillisecond time scale at 700 K using pulsed release of CO and a continuous flow of H2/N2 (ratio 0.067 or 0.15, 1 atm total pressure). Adsorbed carbon monoxide was detected along with gas phase products methane (3016 and 1306 cm-1), water (1900 +- 1300 cm-1), and carbon dioxide (2348 cm-1). Aside from adsorbed CO, no other surface species were observed. The rate of formati… more
Date: June 4, 2008
Creator: Frei, Heinz; Wasylenko, Walter & Frei, Heinz
Partner: UNT Libraries Government Documents Department
open access

Pyrrole Hydrogenation over Rh(111) and Pt(111) Single-Crystal Surfaces and Hydrogenation Promotion Mediated by 1-Methylpyrrole: A Kinetic and Sum-Frequency Generation Vibrational Spectroscopy Study

Description: Sum-frequency generation (SFG) surface vibrational spectroscopy and kinetic measurements using gas chromatography have been used to study the adsorption and hydrogenation of pyrrole over both Pt(111) and Rh(111) single-crystal surfaces at Torr pressures (3 Torr pyrrole, 30 Torr H{sub 2}) to form pyrrolidine and the minor product butylamine. Over Pt(111) at 298 K it was found that pyrrole adsorbs in an upright geometry cleaving the N-H bond to bind through the nitrogen evidenced by SFG data. Ove… more
Date: March 4, 2008
Creator: Kliewer, Christopher J.; Bieri, Marco & Somorjai, Gabor A.
Partner: UNT Libraries Government Documents Department
open access

Integrated Optical Probes

Description: Optical probes used in velocimetry measurements have typically been individual probes that collect data for a single diagnostic at a single point. These probes have been used in diagnostics such as VISAR, PDV, and radiometry, which measure surface velocity, temperature, and other characteristics. When separate probes are used for these measurements, the different diagnostic points measured must be significantly separated. We have developed integrated probes that collect data for multiple optica… more
Date: September 4, 2008
Creator: Brent Frogget, Douglas DeVore, Vincent Romero, David Esquibel, and David Holtkamp
Partner: UNT Libraries Government Documents Department
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