13 Matching Results

Search Results

Results: 1 - 13
open access

Progress with Tevatron Electron Lenses

Description: No Description Available.
Date: September 13, 2007
Creator: Kamerdzhiev, V.; Alexahin, Y.; Kuznetsov, G. F.; Shiltsev, V. D. & Zhang, X.
Partner: UNT Libraries Government Documents Department
open access

New Equalizers for Antiproton Stochastic Cooling at Fermilab

Description: In the continuous effort to improve antiproton stacking rate, a new type of equalizers has been developed and installed in antiproton accumulator. The R&D of these new equalizers is described in this paper. Equalizers are used in Fermilab antiproton stochastic cooling to compensate frequency response of the cooling system. Usually both amplitude and phase compensations are needed. However in most cases it is difficult to achieve a satisfactory compensation for both because of their interdep… more
Date: September 13, 2007
Creator: Lebedev, V. A.; Pasquinelli, R. J. & Sun, D.
Partner: UNT Libraries Government Documents Department
open access

Soft Phonons in (delta)-Phase Plutonium Near the (delta)-(alpha)' Transition

Description: Plutonium and its alloys exhibit complex phase diagrams that imply anomalous lattice dynamics near phase stability boundaries. Specifically, the TA [111] phonon branch in Ga-stabilized {delta}-Pu at room temperature shows a pronounced soft mode at the zone boundary, which suggests a possible connection to the martensitic transformation from the fcc {delta}-phase to the monoclinic {alpha}{prime}-phase at low temperatures. This work is a study of the lattice dynamics of this system by x-ray therm… more
Date: September 13, 2007
Creator: Xu, R; Wong, J; Zshack, P; Hong, H & Chiang, T
Partner: UNT Libraries Government Documents Department
open access

Intrinsic and Extrinsic Chemical and Isotopic Tracers for Characterization Of Groundwater Systems

Description: In many regions, three dimensional characterization of the groundwater regime is limited by coarse well spacing or borehole lithologic logs of low quality. However, regulatory requirements for drinking water or site remediation may require collection of extensive chemical and water quality data from existing wells. Similarly, for wells installed in the distant past, lithologic logs may not be available, but the wells can be sampled for chemical and isotopic constituents. In these situations, a … more
Date: September 13, 2007
Creator: Moran, J E; Singleton, M J; Carle, S F & Esser, B K
Partner: UNT Libraries Government Documents Department
open access

Beam Based Measurements for Stochastic Cooling Systems at Fermilab

Description: Improvement of antiproton stacking rates has been pursued for the last twenty years at Fermilab. The last twelve months have been dedicated to improving the computer model of the Stacktail system. The production of antiprotons encompasses the use of the entire accelerator chain with the exception of the Tevatron. In the Antiproton Source two storage rings, the Debuncher and Accumulator are responsible for the accumulation of antiprotons in quantities that can exceed 2 x 10{sup 12}, but more rou… more
Date: September 13, 2007
Creator: Lebedev, V. A.; Pasquinelli, R. J. & Werkema, S. J.
Partner: UNT Libraries Government Documents Department
open access

Language Classification using N-grams Accelerated by FPGA-based Bloom Filters

Description: N-Gram (n-character sequences in text documents) counting is a well-established technique used in classifying the language of text in a document. In this paper, n-gram processing is accelerated through the use of reconfigurable hardware on the XtremeData XD1000 system. Our design employs parallelism at multiple levels, with parallel Bloom Filters accessing on-chip RAM, parallel language classifiers, and parallel document processing. In contrast to another hardware implementation (HAIL algorithm… more
Date: September 13, 2007
Creator: Jacob, A. & Gokhale, M.
Partner: UNT Libraries Government Documents Department
open access

Closed-String Tachyon Condensation and the Worldsheet Super-Higgs Effect

Description: Alternative gauge choices for worldsheet supersymmetry can elucidate dynamical phenomena obscured in the usual superconformal gauge. In the particular example of the tachyonic E_8 heterotic string, we use a judicious gauge choice to show that the process of closed-string tachyon condensation can be understood in terms of a worldsheet super-Higgs effect. The worldsheet gravitino assimilates the goldstino and becomes a dynamical propagating field. Conformal, but not superconformal, invariance is … more
Date: September 13, 2007
Creator: Horava, Petr; Horava, Petr & Keeler, Cynthia A.
Partner: UNT Libraries Government Documents Department
open access

Self-potential observations during hydraulic fracturing

Description: The self-potential (SP) response during hydraulic fracturing of intact Sierra granite was investigated in the laboratory. Excellent correlation of pressure drop and SP suggests that the SP response is created primarily by electrokinetic coupling. For low pressures, the variation of SP with pressure drop is linear, indicating a constant coupling coefficient (Cc) of -200 mV/MPa. However for pressure drops >2 MPa, the magnitude of the Cc increases by 80% in an exponential trend. This increasing… more
Date: September 13, 2007
Creator: Moore, Jeffrey R. & Glaser, Steven D.
Partner: UNT Libraries Government Documents Department
open access

Magnetism of NiMn2O4-Fe3O4 spinel interfaces

Description: We investigate the magnetic properties of the isostructural spinel-spinel interface of NiMn{sub 2}O{sub 4}(NMO)-Fe{sub 3}O{sub 4}. Although the magnetic transition temperature of the NMO film is preserved, both bulk and interface sensitive measurements demonstrate that the interface exhibits strong interfacial magnetic coupling up to room temperature. While NMO thin films have a ferrimagnetic transition temperature of 60 K, both NiFe{sub 2}O{sub 4} and MnFe{sub 2}O{sub 4} are ferrimagnetic at r… more
Date: September 13, 2007
Creator: Arenholz, Elke; Nelson-Cheeseman, B. B.; Chopdekar, R. V.; Bettinger, J. S.; Arenholz, E. & Suzuki, Y.
Partner: UNT Libraries Government Documents Department
open access

Edge Gyrokinetic Theory and Continuum Simulations

Description: No Description Available.
Date: September 13, 2007
Creator: Xu, X. Q.; Xiong, Z.; Dorr, M. R.; Hittinger, J. A.; Bodi, K.; Candy, J. et al.
Partner: UNT Libraries Government Documents Department
open access

ZEOLITE CHARACTERIZATION TESTING

Description: The Savannah River Site isolates tritium from its process streams for eventual recycling. This is done by catalyzing the formation of tritiated water (from process streams) and then sorbing that water on a 3A zeolite (molsieve) bed. The tritium is recovered by regenerating the saturated bed into a Mg-based water cracking unit. The process described has been in use for about 15 years. Recently chloride stress corrosion cracking (SCC) was noted in the system piping. This has resulted in the need … more
Date: September 13, 2007
Creator: Jacobs, W & Herbert Nigg, H
Partner: UNT Libraries Government Documents Department
open access

The Sloan Digital Sky Survey Quasar Lens Search. Ii. Statistical Lens Sample From Thethird Data Release

Description: We report the first results of our systematic search for strongly lensed quasars using the spectroscopically confirmed quasars in the Sloan Digital Sky Survey (SDSS). Among 46,420 quasars from the SDSS Data Release 3 ({approx}4188 deg{sup 2}), we select a subsample of 22,683 quasars that are located at redshifts between 0.6 and 2.2 and are brighter than the Galactic extinction corrected i-band magnitude of 19.1. We identify 220 lens candidates from the quasar subsample, for which we conduct ext… more
Date: September 13, 2007
Creator: Inada, N.; Oguri, M.; Becker, R. H.; Shin, M.; Richards, G. T.; Hennawi, J. F. et al.
Partner: UNT Libraries Government Documents Department

Experimental Thermochemical Study of 6-Chloro-2,3-dimethylquinoxaline 1,4-dioxide and DFT evaluation of the N-O bond enthalpies in related haloquinoxalines

Description: Article discussing an experimental thermochemical study of 6-chloro-2,3-dimethylquinoxaline 1,4-dioxide and DFT evaluation of the N-O bond enthalpies in related haloquinoxalines.
Access: Restricted to UNT Community Members. Login required if off-campus.
Date: September 13, 2007
Creator: Gomes, José R. B.; Vieira, Mónica A. A.; Stovall, Dawn M.; Acree, William E. (William Eugene) & Silva, Maria D. M. C. Ribeiro da
Partner: UNT College of Arts and Sciences
Back to Top of Screen