93 Matching Results

Search Results

Results: 1 - 24 next
open access

Pulse Radiolysis of Aqueous Thiocyanate Solution

Description: The pulse radiolysis of N2O saturated aqueous solutions of KSCN was studied under neutral pH conditions. The observed optical absorption spectrum of the SCN• radical in solution is more complex than previously reported, but it is in good agreement with that measured in the gas phase. Kinetic traces at 330 nm and 472 nm corresponding to SCN• and (SCN)2•¯, respectively, were fit using a Monte Carlo simulation kinetic model. The rate coefficient for the oxidation of SCN¯ ions by OH radicals, an im… more
Date: January 13, 2005
Creator: Milosavljevic, Bratoljub H. & LaVerne, Jay A.
Partner: UNT Libraries Government Documents Department
open access

Ion-Optics Calculations and Preliminary Precision Estimates of the Gas-Capable Ion Source for the 1-MV LLNL BioAMS Spectrometer

Description: Ion-optics calculations were performed for a new ion source and injection beam line. This source, which can accept both solid and gaseous targets, will be installed onto the 1-MV BioAMS spectrometer at the Center for Accelerator Mass Spectrometry, located at Lawrence Livermore National Laboratory and will augment the current LLNL cesium-sputter solid sample ion source. The ion source and its associated injection beam line were designed to allow direct quantification of {sup 14}C/{sup 12}C and {… more
Date: December 13, 2005
Creator: Ognibene, T. J.; Bench, G.; Brown, T. A. & Vogel, J. S.
Partner: UNT Libraries Government Documents Department
open access

Evidence for Groundwater Contamination Vulnerability in California?s Central Valley

Description: The California Water Resources Control Board, in collaboration with the US Geological Survey and Lawrence Livermore National Laboratory, has implemented a program to assess the susceptibility of groundwater resources. Advanced techniques such as groundwater age dating using the tritium-helium method, extensive use of oxygen isotopes of the water molecule ({delta}{sup 18}O) for recharge water provenance, and analysis of common volatile organic compounds (VOCs) at ultra-low levels are applied wit… more
Date: December 13, 2005
Creator: Moran, J. E.; Leif, R.; Esser, B. K. & Singleton, M. J.
Partner: UNT Libraries Government Documents Department
open access

Two Strategies to Speed up Connected Component LabelingAlgorithms

Description: This paper presents two new strategies to speed up connectedcomponent labeling algorithms. The first strategy employs a decisiontreeto minimize the work performed in the scanning phase of connectedcomponent labeling algorithms. The second strategy uses a simplifiedunion-find data structure to represent the equivalence information amongthe labels. For 8-connected components in atwo-dimensional (2D) image,the first strategy reduces the number of neighboring pixels visited from4 to7/3 on average. … more
Date: November 13, 2005
Creator: Wu, Kesheng; Otoo, Ekow & Suzuki, Kenji
Partner: UNT Libraries Government Documents Department
open access

Modeling and Experimental Investigation of Methylcyclohexane Ignition in a Rapid Compression Machine

Description: A new mechanism for the oxidation of methylcyclohexane has been developed. The mechanism combined a newly-developed low temperature mechanism with a previously developed high temperature mechanism. Predictions from the chemical kinetic model have been compared to experimentally measured ignition delay times from a rapid compression machine. Predicted ignition delay times using the initial estimates of the methylcyclohexyl peroxy radical isomerization rate constants were much longer than those m… more
Date: October 13, 2005
Creator: Pitz, W J; Naik, C V; Mhaold?in, T N; Curran, H J; Orme, J P; Simmie, J M et al.
Partner: UNT Libraries Government Documents Department
open access

Volumetric data analysis using Morse-Smale complexes

Description: The 3D Morse-Smale complex is a fundamental topological construct that partitions the domain of a real-valued function into regions having uniform gradient flow behavior. In this paper, we consider the construction and selective presentation of cells of the Morse-Smale complex and their use in the analysis and visualization of scientific datasets. We take advantage of the fact that cells of different dimension often characterize different types of features present in the data. For example, crit… more
Date: October 13, 2005
Creator: Natarajan, V & Pascucci, V
Partner: UNT Libraries Government Documents Department
open access

After-hours Power Status of Office Equipment in the USA

Description: Office equipment is expected to be the fastest-growingsegment of commercial energy use over the next 20 years, yet many aspectsof office equipment energy use are poorly understood. User behavior, suchas turning off devices at night or enabling power management, influencesenergy use to a great extent. The computing environment also plays a roleboth in influencing user behavior and in the success of power management.Information about turn-off rates and power management rates for officeequipment w… more
Date: October 13, 2005
Creator: Webber, Carrie A.; Roberson, Judy A.; McWhinney, Marla C.; Brown,Richard E.; Pinckard, Margaret J. & Busch, John F.
Partner: UNT Libraries Government Documents Department
open access

Accelerator and Ion Beam Tradeoffs for Studies of Warm Dense Matter

Description: One approach for heating a target to ''Warm Dense Matter'' conditions (similar, for example, to the interiors of giant planets or certain stages in Inertial Confinement Fusion targets), is to use intense ion beams as the heating source (see refs.[6] and [7] and references therein for motivation and accelerator concepts). By consideration of ion beam phase space constraints, both at the injector, and at the final focus, and consideration of simple equations of state and relations for ion stoppin… more
Date: May 13, 2005
Creator: Barnard, J. J.; Briggs, R. J.; Callahan, D. A.; Davidson, R. C.; Friedman, A.; Grisham, L. et al.
Partner: UNT Libraries Government Documents Department
open access

Viable Supersymmetry and Leptogenesis with Anomaly Mediation

Description: The seesaw mechanism that explains the small neutrino masses comes naturally with supersymmetric (SUSY) grand unification and leptogenesis. However, the framework suffers from the SUSY flavor and CP problems, and has a severe cosmological gravitino problem. We propose anomaly mediation as a simple solution to all these problems, which is viable once supplemented by the D-terms for U(1)_Y and U(1)_B-L. Even though the right-handed neutrino mass explicitly breaks U(1)_B-L and hence reintroduces t… more
Date: January 13, 2005
Creator: Ibe, Masahiro; Kitano, Ryuichiro; Murayama, Hitoshi & Yanagida, Tsutomu
Partner: UNT Libraries Government Documents Department
open access

Contrasting Supersymmetry and Universal Extra Dimensions at the CLIC Multi-TeV e+e- Collider

Description: Universal extra dimensions and supersymmetry have rather similar experimental signatures at hadron colliders. The proper interpretation of an LHC discovery in either case may therefore require further data from a lepton collider. In this paper we identify methods for discriminating between the two scenarios at the linear collider. We study the processes of Kaluza-Klein muon pair production in universal extra dimensions in parallel to smuon pair production in supersymmetry, accounting for the ef… more
Date: July 13, 2005
Creator: Battaglia, Marco; Datta, AseshKrishna; De Roeck, Albert; Kong, Kyoungchul & Matchev, Konstantin T.
Partner: UNT Libraries Government Documents Department
open access

The New Minimal Standard Model

Description: We construct the New Minimal Standard Model that incorporates the new discoveries of physics beyond the Minimal Standard Model (MSM): Dark Energy, non-baryonic Dark Matter, neutrino masses, as well as baryon asymmetry and cosmic inflation, adopting the principle of minimal particle content and the most general renormalizable Lagrangian. We base the model purely on empirical facts rather than aesthetics. We need only six new degrees of freedom beyond the MSM. It is free from excessive flavor-cha… more
Date: January 13, 2005
Creator: Davoudiasl, Hooman; Kitano, Ryuichiro; Li, Tianjun & Murayama, Hitoshi
Partner: UNT Libraries Government Documents Department
open access

Electrical activation and spin coherence of ultra low doseantimony implants in silicon

Description: We implanted ultra low doses (0.2 to 2 x 10{sup 11} cm{sup -2}) of Sb ions into isotopically enriched {sup 28}Si, and probed electrical activation and electron spin relaxation after rapid thermal annealing. Strong segregation of dopants towards both Si{sub 3}N{sub 4} and SiO{sub 2} interfaces limits electrical activation. Pulsed Electron Spin Resonance shows that spin echo decay is sensitive to the dopant profiles, and the interface quality. A spin decoherence time, T{sub 2}, of 1.5 ms is found… more
Date: July 13, 2005
Creator: Schenkel, T.; Tyryshkin, A. M.; de Sousa, R.; Whaley, K. B.; Bokor, J.; Liddle, J. A. et al.
Partner: UNT Libraries Government Documents Department
open access

ASM Conference on Prokaryotic Development

Description: Support was provided by DOE for the 2nd ASM Conference on Prokaryotic Development. The final conference program and abstracts book is attached. The conference presentations are organized around topics that are central to the current research areas in prokaryotic development. The program starts with topics that involve relatively simple models systems and ends with systems that are more complex. The topics are: i) the cell cycle, ii) the cytoskeleton, iii) morphogenesis, iv) developmental transc… more
Date: July 13, 2005
Creator: Kaplan, H. B.
Partner: UNT Libraries Government Documents Department
open access

Hot Surface Ionic Line Emission and Cold K-Inner Shell Emission From Petawatt-Laser Irradiated Cu Foil Targets

Description: A hot, T{sub e} {approx} 2- to 3-keV surface plasma was observed in the interaction of a 0.7-ps petawatt laser beam with solid copper-foil targets at intensities >10{sup 20} W/cm{sup 2}. Copper K-shell spectra were measured in the range of 8 to 9 keV using a single-photon-counting x-ray CCD camera. In addition to K{sub {alpha}} and K{sub {beta}} inner-shell lines, the emission contained the Cu He{sub {alpha}} and Ly{sub {alpha}} lines, allowing the temperature to be inferred. These lines hav… more
Date: December 13, 2005
Creator: Theobald, W.; Akli, K.; Clarke, R.; Delettrez, J. A.; Freeman, R. R.; Glenzer, S. et al.
Partner: UNT Libraries Government Documents Department
open access

High Harmonic Inverse Free-Electron-Laser Interaction at 800nm

Description: The inverse Free Electron Laser (IFEL) interaction has recently been proposed and used as a short wavelength modulator for micro bunching of beams for laser acceleration experiments [1,2]. These experiments utilized the fundamental of the interaction between the laser field and electron bunch. In the current experiment, we explore the higher order resonances of the IFEL interaction from a 3 period, 1.8 centimeter wavelength undulator with a picosecond, 0.5 mJ/pulse laser at 800nm. The resonance… more
Date: May 13, 2005
Creator: Sears, Christopher M. S.; Colby, Eric; Cowan, Ben; Siemann, Robert H.; Spencer, James; Byer, Robert L. et al.
Partner: UNT Libraries Government Documents Department
open access

Interpreting Velocities from Heat-Based Flow Sensors by NumericalSimulation

Description: We have carried out numerical simulations of three-dimensional non-isothermal flow around an in situ heat-based flow sensor to investigate how formation heterogeneities can affect the interpretation of ground water flow velocities from this instrument. The flow sensor operates by constant heating of a 0.75 m long, 5 cm diameter cylindrical probe, which contains 30 thermistors in contact with the formation. The temperature evolution at each thermistor can be inverted to obtain an estimate of the… more
Date: June 13, 2005
Creator: Su, Grace W.; Freifeld, Barry M.; Oldenburg, Curtis M.; Jordan,Preston D. & Daley, Paul F.
Partner: UNT Libraries Government Documents Department
open access

Proc. of the workshop on pushing the limits of RF superconductivity.

Description: For three days in late September last year, some sixty experts in RF superconductivity from around the world came together at Argonne to discuss how to push the limits of RF superconductivity for particle accelerators. It was an intense workshop with in-depth presentations and ample discussions. There was added excitement due to the fact that, a few days before the workshop, the International Technology Recommendation Panel had decided in favor of superconducting technology for the Internationa… more
Date: April 13, 2005
Creator: Kim, K-J., Eyberger, C., editors
Partner: UNT Libraries Government Documents Department
open access

In-Situ Phase Mapping and Direct Observations of Phase Transformations During Arc Welding of 1045 Steel

Description: In-situ Spatially Resolved X-Ray Diffraction (SRXRD) experiments were performed during gas tungsten arc (GTA) welding of AISI 1045 C-Mn steel. Ferrite ({alpha}) and austenite ({gamma}) phases were identified and quantified in the weld heat-affected zone (HAZ) from the real time x-ray diffraction data. The results were compiled along with weld temperatures calculated using a coupled thermal fluids weld model to create a phase map of the HAZ. This map shows the {alpha} {yields} {gamma} transforma… more
Date: September 13, 2005
Creator: Elmer, J. & Palmer, T.
Partner: UNT Libraries Government Documents Department
open access

Tera-scalable Algorithms for Variable-Density Elliptic Hydrodynamics with Spectral Accuracy

Description: A hybrid spectral/compact solver for variable-density viscous incompressible flow is described. Parallelization strategies for the FFTs and band-diagonal matrices are discussed and compared. Transpose methods are found to be highly competitive with direct block parallel methods when the problem is scaled to tens of thousands of processors. Various mapping strategies for the IBM BlueGene/L torus configuration of processors are explored. By optimizing the communication, we have achieved virtually… more
Date: April 13, 2005
Creator: Cook, A. W.; Cabot, W. H.; Welcome, M. L.; Williams, P. L.; Miller, B. J.; de Supinski, B. R. et al.
Partner: UNT Libraries Government Documents Department
open access

A Study of $e^+e^-\to p\bar{p}$ Using Initial StateRadiation with BaBar

Description: The e{sup +}e{sup -} {yields} p{bar p} cross-section is determined over a range of p{bar p} masses, from threshold to 4.5 GeV/c{sup 2}, by studying the e{sup +}e{sup -} {yields} p{bar p}{gamma} process. The data set corresponds to an integrated luminosity of 232 fb{sup -1}, collected with the BABAR detector at the PEP-II storage ring, at an e{sup +}e{sup -} center-of-mass energy of 10.6 GeV. The mass dependence of the ratio of electric and magnetic form factors, |G{sub E}/G{sub M}|, is measured… more
Date: December 13, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
Partner: UNT Libraries Government Documents Department
open access

LSP Calculations of Cone-Wire Experiments

Description: Recent experiments at the Institute of Laser Engineering (ILE) in Japan [1] and at Rutherford Appleton Laboratory (RAL) in the United Kingdom [2] have shown good coupling of short-pulse high-intensity laser light into high-energy electrons channeled down a narrow fiber. Such target configurations are being considered as backlighter targets on the National Ignition Facility (NIF). We will report on LSP calculations of these cone-wire experiments and other candidate target configurations. These c… more
Date: June 13, 2005
Creator: Town, R. J.; Cottrill, L. A.; Key, M. H.; Kruer, W. L.; Langdon, A. B.; Lasinski, B. F. et al.
Partner: UNT Libraries Government Documents Department
open access

Angularly Adaptive P1-Double P0 Flux-Limited Diffusion Solutions of Non-Equilibrium Grey Radiative Transfer Problems

Description: The double spherical harmonics angular approximation in the lowest order, i.e. double P{sub 0} (DP{sub 0}), is developed for the solution of time-dependent non-equilibrium grey radiative transfer problems in planar geometry. Although the DP{sub 0} diffusion approximation is expected to be less accurate than the P{sub 1} diffusion approximation at and near thermodynamic equilibrium, the DP{sub 0} angular approximation can more accurately capture the complicated angular dependence near a non-equi… more
Date: December 13, 2005
Creator: Brantley, P S
Partner: UNT Libraries Government Documents Department
open access

Laser Safety Inspection Criteria

Description: A responsibility of the Laser Safety Officer (LSO) is to perform laser audits. The American National Standard Z136.1 Safe Use of Lasers references this requirement through several sections. One such reference is Section 1.3.2.8, Safety Features Audits, ''The LSO shall ensure that the safety features of the laser installation facilities and laser equipment are audited periodically to assure proper operation''. The composition, frequency and rigor of that inspection/audit rests in the hands of th… more
Date: June 13, 2005
Creator: Barat, K.
Partner: UNT Libraries Government Documents Department
open access

Multi-century Changes to Global Climate and Carbon Cycle: Results from a Coupled Climate and Carbon Cycle Model

Description: In this paper, we use a coupled climate and carbon cycle model to investigate the global climate and carbon cycle changes out to year 2300 that would occur if CO2 emissions from all the currently estimated fossil fuel resources were released to the atmosphere. By year 2300, the global climate warms by about 8 K and atmospheric CO2 reaches 1423 ppmv. In our simulation, the prescribed cumulative emission since pre-industrial period is about 5400 Gt-C by the end of 23rd century. At year 2300, near… more
Date: June 13, 2005
Creator: Bala, G.; Caldeira, K.; Mirin, A.; Wickett, M. & Delire, C.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen