Rapidity and species dependence of particle production at largetransverse momentum for d+Au collisions at psNN = 200 GeV (open access)

Rapidity and species dependence of particle production at largetransverse momentum for d+Au collisions at psNN = 200 GeV

We determine rapidity asymmetry in the production of charged pions, protons and anti-protons for large transverse momentum (p{sub T}) for d+Au collisions at {radical}s{sub NN} = 200 GeV. The rapidity asymmetry is defined as the ratio of particle yields at backward rapidity (Au beam direction or -ve rapidity) to those at forward rapidity (d beam direction or +ve rapidity). The identified hadrons are measured in the rapidity regions |y| < 0.5 and 0.5 < |y| < 1.0 for the p{sub T} range 2.5 < p{sub T} < 10 GeV/c. We observe significant rapidity asymmetry for charged pion and proton+anti-proton production in both rapidity regions. The asymmetry is larger for 0.5 < |y| < 1.0 than for |y| < 0.5 and is almost independent of particle type. The measurements are compared to various model predictions employing multiple scattering, energy loss, nuclear shadowing, saturation effects, and recombination, and also to a phenomenological parton model. We find that asymmetries are sensitive to model parameters and show model-preference. The rapidity dependence of {pi}{sup -}/{pi}{sup +} and {bar p}/p ratios in peripheral d+Au and forward neutron-tagged events are used to study the contributions of valence quarks and gluons to particle production at high p{sub T}. …
Date: December 19, 2006
Creator: Abelev, B. I.; Adams, J.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D. et al.
Object Type: Report
System: The UNT Digital Library
Final Technical Report ARM DOE Grant #DE-FG02-03ER63520 Parameterizations of Shortwave Radiactive Properties of Broken Clouds from Satellite and Ground-Based Measurements (open access)

Final Technical Report ARM DOE Grant #DE-FG02-03ER63520 Parameterizations of Shortwave Radiactive Properties of Broken Clouds from Satellite and Ground-Based Measurements

This study used DOE ARM data and facilities to: 1) study macroscopic properties of continental stratus clouds at SGP and the factors controlling these properties, 2) develop a scientific basis for understanding the pocesses responsible for the formation of boundary layer clouds using ARM observations in conjunction with simple parametric models and LES, and 3) evaluate cumulus cloud characteristics retrieved retrieved from the MMCR operating at TWP-Nauru. In addition we have used high resolution 94 GHz observations of boundary layer clouds and precipitation to: 1)develop techniques for using high temporal resolution Doppler velocities to study large-eddy circulations and turbulence in boundary layer clouds and estimate the limitations of using current and past MMCR data for boundary layer cloud studies, 2) evaluate the capability and limitation of the current MMCR data for estimating reflectivity, vertical velocities, and spectral under low-signal-to-noise conditions associated with weak non-precipitating clouds, 3) develop possible sampling modes for the new MMCR processors to allow for adequate sampling of boundary layer clouds, and 4) retrieve updraft and downdraft structures under precipitating conditions.
Date: June 19, 2006
Creator: Albrecht, Bruce, A.
Object Type: Report
System: The UNT Digital Library
Promotion of Efficient Use of Energy: Final Report (open access)

Promotion of Efficient Use of Energy: Final Report

The Department of Energy funded the Alliance to Save Energy to promote the efficient use of energy under a multiyear cooperative agreement. This funding allowed the Alliance to be innovative and flexible in its program development, and to initiate and enhance projects it would otherwise not have been able to pursue. The program period was 1999 through 2004. The mission of the Alliance to Save Energy is to promote energy efficiency domestically and worldwide. The Alliance followed this mission by working closely with consumers, government, policy makers, and energy efficient product and service providers. The projects that were initiated by the Alliance included communication and consumer education, policy analysis and research, the promotion of interaction among the energy efficiency industry, and international energy efficiency programs. The funding from the Department of Energy allowed the Alliance to study new issues in energy efficiency, draw public attention to those issues, and create targeted programs, such as the Efficient Windows Collaborative or the Green Schools program, which now function on their own to promote energy efficiency in important areas.
Date: January 19, 2006
Creator: Alliance to Save Energy (U.S.)
Object Type: Report
System: The UNT Digital Library
Geant4 Developments And Applications (open access)

Geant4 Developments And Applications

None
Date: May 19, 2006
Creator: Allison, J.; Amako, K.; Apostolakis, J.; Araujo, H.; Dubois, P.A.; Asai, M. et al.
Object Type: Article
System: The UNT Digital Library
Assessing the Effects of Radiation Damage on Ni-base Alloys for the Prometheus Space Reactor System (open access)

Assessing the Effects of Radiation Damage on Ni-base Alloys for the Prometheus Space Reactor System

Ni-base alloys were considered for the Prometheus space reactor pressure vessel with operational parameters of {approx}900 K for 15 years and fluences up to 160 x 10{sup 20} n/cm{sup 2} (E > 0.1 MeV). This paper reviews the effects of irradiation on the behavior of Ni-base alloys and shows that radiation-induced swelling and creep are minor considerations compared to significant embrittlement with neutron ,exposure. While the mechanism responsible for radiation-induced embrittlement is not fully understood, it is likely a combination of helium embrittlement and solute segregation that can be highly dependent on the alloy composition and exposure conditions. Transmutation calculations show that detrimental helium levels would be expected at the end of life for the inner safety rod vessel (thimble) and possibly the outer pressure vessel, primarily from high energy (E > 1 MeV) n,{alpha} reactions with {sup 58}Ni. Helium from {sup 10}B is significant only for the outer vessel due to the proximity of the outer vessel to the Be0 control elements. Recommendations for further assessments of the material behavior and methods to minimize the effects of radiation damage through alloy design are provided.
Date: January 19, 2006
Creator: Angeliu, T.
Object Type: Report
System: The UNT Digital Library
Seismic Design and Retrofit of Equipment and Piping (open access)

Seismic Design and Retrofit of Equipment and Piping

None
Date: April 19, 2006
Creator: Antaki, George
Object Type: Article
System: The UNT Digital Library
Integrity of Pipes and Vessels Subject to Internal Explosions: an overview (open access)

Integrity of Pipes and Vessels Subject to Internal Explosions: an overview

None
Date: April 19, 2006
Creator: Antaki, George; McKeel, Charles & Pease, Derrick
Object Type: Article
System: The UNT Digital Library
Observation of Decays $B^0\to D_s^{(*)+}\pi^-$ and$B^0\to D_s^{(*)-}K^+$ (open access)

Observation of Decays $B^0\to D_s^{(*)+}\pi^-$ and$B^0\to D_s^{(*)-}K^+$

The authors report the observation of decays B{sup 0} {yields} D{sub s}{sup (*)+} {pi}{sup -} and B{sup 0} {yields} D{sub s}{sup (*)-} K{sup +} in a sample of 230 x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} events recorded with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} storage ring. They measure the branching fractions {Beta}(B{sup 0} {yields} D{sub s}{sup +}{pi}{sup -}) = (1.3 {+-} 0.3(stat) {+-} 0.2(syst)) x 10{sup -5}, {Beta}(B{sup 0} {yields} D{sub s}{sup -}K{sup +}) = (2.5 {+-} 0.4(stat) {+-} 0.4(syst)) x 10{sup -5}, {Beta}(B{sup 0} {yields} D*{sub s}{sup +} {pi}{sup -}) = (2.8 {+-} 0.6(stat) {+-} 0.5 (syst)) x 10{sup -5}, and {Beta}(B{sup 0} {yields} D*{sub s}{sup -} K{sup +}) = (2.0 {+-} 0.5(stat) {+-} 0.4(syst)) x 10{sup -5}. The significance of the measurements to differ from zero are 5, 9, 6, and 5 standard deviations, respectively.
Date: April 19, 2006
Creator: Aubert, B.
Object Type: Report
System: The UNT Digital Library
Observation of $\Upsilon(4S) decays to$\pi^+pi^-\Upsilon(1S)$ and $\pi^+pi^-\Upsilon(1S)$ (open access)

Observation of $\Upsilon(4S) decays to$\pi^+pi^-\Upsilon(1S)$ and $\pi^+pi^-\Upsilon(1S)$

The authors present the first measurement of {Upsilon}(4S) decays to {pi}{sup +}{pi}{sup -} {Upsilon}(1S) and {pi}{sup +}{pi}{sup -} {Upsilon}(2S) based on a sample of 230 x 10{sup 6} {Upsilon}(4S) mesons collected with the BABAR detector. They measure the product branching fractions {Beta}({Upsilon}(4S) {yields} {pi}{sup +}{pi}{sup -} {Upsilon}(1S)) x {Beta}({Upsilon}(1S) {yields} {mu}{sup +}{mu}{sup -}) = (2.23 {+-} 0.25{sub stat} {+-} 0.27{sub sys}) x 10{sup -6} and {Beta}({Upsilon}(4S) {yields} {pi}{sup +}{pi}{sup -}{Upsilon}(2S)) x {Beta}({Upsilon}(2S) {yields} {mu}{sup +}{mu}{sup -}) = (1.69 {+-} 0.26{sub stat} {+-} 0.20{sub sys}) x 10{sup -6}, from which they derive the partial widths {Lambda}({Upsilon}(4S) {yields} {pi}{sup +}{pi}{sup -} {Upsilon}(1S)) = (1.8 {+-} 0.4) keV and {Lambda}({Upsilon}(4S) {yields} {pi}{sup +}{pi}{sup -}{Upsilon}(2S)) = (2.7 {+-} 0.8) keV.
Date: April 19, 2006
Creator: Aubert, B.
Object Type: Report
System: The UNT Digital Library
A Study of the DsJ(2317) and DsJ(2460) Mesons in Inclusive ccbar Production near sqrt(s) = 10.6 GeV (open access)

A Study of the DsJ(2317) and DsJ(2460) Mesons in Inclusive ccbar Production near sqrt(s) = 10.6 GeV

A study of the D*{sub sJ}(2317){sup +} and D{sub sJ}(2460){sup +} mesons in inclusive c{bar c} production is presented using 232 fb{sup -1} of data collected by the BABAR experiment near {radical}s = 10.6 GeV. Final states consisting of a D{sub s}{sup +} meson along with one or more {pi}{sup 0}, {pi}{sup {+-}}, or {gamma} particles are considered. Estimates of the mass and limits on the width are provided for both mesons and for the D{sub s1}(2536){sup +} meson. A search is also performed for neutral and doubly-charged partners of the D*{sub sJ}(2317){sup +} meson.
Date: April 19, 2006
Creator: Aubert, B.
Object Type: Report
System: The UNT Digital Library
On-Line Coolant Chemistry Analysis (open access)

On-Line Coolant Chemistry Analysis

Impurities in the gas coolant of the space nuclear power plant (SNPP) can provide valuable indications of problems in the reactor and an overall view of system health. By monitoring the types and amounts of these impurities, much can be implied regarding the status of the reactor plant. However, a preliminary understanding of the expected impurities is important before evaluating prospective detection and monitoring systems. Currently, a spectroscopy system is judged to hold the greatest promise for monitoring the impurities of interest in the coolant because it minimizes the number of entry and exit points to the plant and provides the ability to detect impurities down to the 1 ppm level.
Date: July 19, 2006
Creator: Bachman, LM
Object Type: Report
System: The UNT Digital Library
Wakefields of Sub-Picosecond Electron Bunches (open access)

Wakefields of Sub-Picosecond Electron Bunches

We discuss wakefields excited by short bunches in accelerators. In particular, we review some of what has been learned in recent years concerning diffraction wakes, roughness impedance, coherent synchrotron radiation wakes, and the resistive wall wake, focusing on analytical solutions where possible. As examples, we apply formulas for these wakes to various parts of the Linac Coherent Light Source (LCLS) project. The longitudinal accelerator structure wake of the SLAC linac is an important ingredient in the LCLS bunch compression process. Of the wakes in the undulator region, the dominant one is the resistive wall wake of the beam pipe.
Date: April 19, 2006
Creator: Bane, Karl L. F.
Object Type: Article
System: The UNT Digital Library
Beam Dynamics in a Spectrometer for the Polarized Positron Production Experiment (open access)

Beam Dynamics in a Spectrometer for the Polarized Positron Production Experiment

The proposed experiment E-166 at SLAC is designed to demonstrate the possibility of producing longitudinally polarized positrons from circularly polarized photons to be used in future Linear Collider. The experimental set-up utilizes a low emittance 50 GeV electron beam passing through a helical undulator in the Final Focus Test Beam line of the SLAC accelerator. Circularly polarized photons generated by the electron beam in the undulator hit a target and produce electron-positron pairs. The purpose of the post-target spectrometer is to select the positron beam and to deliver it to a polarimeter whilst keeping the positron beam polarization as high as possible. This paper analyzes positron transmission and polarization in the E-166 spectrometer experiment. The positron transmission has a maximum value of 7% for a positron beam energy of 5.5 MeV, while positron polarization is approximately 60%.
Date: April 19, 2006
Creator: Batygin, Yuri K.
Object Type: Report
System: The UNT Digital Library
Principal component, varimax rotation and cost analysis of volume effects in rectal bleeding in patients treated with 3D-CRT for prostate cancer (open access)

Principal component, varimax rotation and cost analysis of volume effects in rectal bleeding in patients treated with 3D-CRT for prostate cancer

None
Date: April 19, 2006
Creator: Bauer, J. D.; Jackson, A.; Skwarchuk, M. & Zelefsky, M.
Object Type: Article
System: The UNT Digital Library
VACET: Proposed SciDAC2 Visualization and Analytics Center forEnabling Technologies (open access)

VACET: Proposed SciDAC2 Visualization and Analytics Center forEnabling Technologies

This paper accompanies a poster that is being presented atthe SciDAC 2006 meeting in Denver, CO. This project focuses on leveragingscientific visualization and analytics software technology as an enablingtechnology for increasing scientific productivity and insight. Advancesincomputational technology have resultedin an "information big bang,"which in turn has createda significant data understanding challenge. Thischallenge is widely acknowledged to be one of the primary bottlenecks incontemporary science. The vision for our Center is to respond directly tothat challenge by adapting, extending, creating when necessary anddeploying visualization and data understanding technologies for ourscience stakeholders. Using an organizational model as a Visualizationand Analytics Center for Enabling Technologies (VACET), we are wellpositioned to be responsive to the needs of a diverse set of scientificstakeholders in a coordinated fashion using a range of visualization,mathematics, statistics, computer and computational science and datamanagement technologies.
Date: June 19, 2006
Creator: Bethel, W.; Johnson, Chris; Hansen, Charles; Parker, Steve; Sanderson, Allen; Silva, Claudio et al.
Object Type: Article
System: The UNT Digital Library
Modification of Edge Plasma Turbulence by External Magnetic Pertubations (open access)

Modification of Edge Plasma Turbulence by External Magnetic Pertubations

Magnetostatic perturbations applied to the DIII-D plasma using a n=3 coil set have significant impact on the plasma edge, such as edge localized mode (ELM) suppression [1], but also affect the background turbulence levels. Discharges with parameters R=1.75 m, a=0.56 m, B{sub T} {approx} 1.6 T, I{sub p} {approx} 1 MA and n{sub e} {approx} 3 x 10{sup 13} cm{sup -3}-n{sub e} {approx} 7 x 10{sup 13} cm{sup -3} (low, v*{sub e} {approx} 0.1 and moderate, v*{sub e} {approx} 1 electron pedestal collisionality) were used as a target for the perturbation, [applied at 3 s Fig. 1(a) and 2 s Fig. 1(b)]. The global density and energy content, among many other parameters, are unaffected, raising the issue of what mechanism replaces the particle and heat exhaust otherwise mediated by ELMs. Mixed ELMs (high frequency, low amplitude Type II ELMs interspersed with Type I) in the moderate collisionality regime and Type I ELMs in the low collisionality regime, are replaced by intermittency and broadband turbulence or semiperiodic events. It is important to notice that the coils can be energized in high poloidal mode spectra (upper and lower coils produce fields in the same direction) or odd configuration (upper and lower coils …
Date: June 19, 2006
Creator: Boedo, J.; McKee, G.; Rudakov, D.; Reiser, D.; Evans, T.; Moyer, R. et al.
Object Type: Article
System: The UNT Digital Library
1958-2006 Precipitation Climatology for Lawrence Livermore National Laboratory Livermore Site and Site 300 (open access)

1958-2006 Precipitation Climatology for Lawrence Livermore National Laboratory Livermore Site and Site 300

This report contains rainfall climatology and analyses during the period from 1958 to 2006 for the two sites of Lawrence Livermore National Laboratory: the Livermore site and Site 300. The measurement sites are described, a regional climatology overview is provided, and the effect of topography on regional precipitation is discussed. Rainfall statistics are presented including monthly normals (30-year means) and medians; percentages of time that rainfall is less than or equal to specified amounts for given months, years, and seasons; and mean, median, and maximum numbers of days of precipitation for specified amounts by month, year, and season. The rainfall pattern is demonstrated to be typical of Mediterranean climates, with most rain falling during the cold season. Nearly 80% of seasonal rainfall occurs during November through March, with the average annual rainfall equaling 13.62 and 10.64 inches at the Livermore site and Site 300, respectively. Precipitation frequency and extreme value analyses for durations ranging from 15 minutes to 24 hours, month, and rainfall season are shown in order to estimate rainfall amounts for return periods of two to 100 years at both sites. This analysis determined 100-year return periods for largest 24-hour rainfalls of 2.49 and 2.22 inches at the …
Date: December 19, 2006
Creator: Bowen, B M
Object Type: Report
System: The UNT Digital Library
Formal Specification of the OpenMP Memory Model (open access)

Formal Specification of the OpenMP Memory Model

OpenMP [2] is an important API for shared memory programming, combining shared memory's potential for performance with a simple programming interface. Unfortunately, OpenMP lacks a critical tool for demonstrating whether programs are correct: a formal memory model. Instead, the current official definition of the OpenMP memory model (the OpenMP 2.5 specification [2]) is in terms of informal prose. As a result, it is impossible to verify OpenMP applications formally since the prose does not provide a formal consistency model that precisely describes how reads and writes on different threads interact. We expand on our previous work that focused on the formal verification of OpenMP programs through a formal memory model [?]. As in that work, our formalization, which is derived from the existing prose model [2], provides a two-step process to verify whether an observed OpenMP execution is conformant. This paper extends the model to cover the entire specification. In addition to this formalization, our contributions include a discussion of ambiguities in the current prose-based memory model description. Although our formal model may not capture the current informal memory model perfectly, in part due to these ambiguities, our model reflects our understanding of the informal model's intent. We conclude with …
Date: December 19, 2006
Creator: Bronevetsky, G & de Supinski, B
Object Type: Article
System: The UNT Digital Library
FERRATES: SYNTHESIS, PROPERTIES AND APPLICATIONS IN WATER AND WASTEWATER TREATMENT. (open access)

FERRATES: SYNTHESIS, PROPERTIES AND APPLICATIONS IN WATER AND WASTEWATER TREATMENT.

The higher oxidation states of iron (Fe(VI) and Fe(V) in particular) have been shown to be strongly oxidizing in enzymatic systems, where they can carry out aliphatic hydrogen abstraction. In addition, they have been postulated as intermediates in Fenton-type systems. Fe(VI) itself is relatively stable and has been shown to have potential as an oxidant in the so-called ''green'' treatment of polluted waters. By contrast, Fe(V) is a relatively short-lived transient when produced in aqueous solution in the absence of strongly bonding ligands other than hydroxide, a feature that has limited studies of its reactivity. Fe(VI) has been proposed to be useful in battery design and a very interesting study suggested that ferrate may be able to oxidize insoluble chromium to chromate and thus serve to remove chromium contamination in the Hanford radioactive waste tanks.
Date: May 19, 2006
Creator: CABELLI, D.E. & SHARMA, V.K.
Object Type: Article
System: The UNT Digital Library
Phase II Calderon Process to Produce Direct Reduced Iron Research and Development Project Quarterly Report: January-March 2006 (open access)

Phase II Calderon Process to Produce Direct Reduced Iron Research and Development Project Quarterly Report: January-March 2006

This project was initially targeted to the making of coke for blast furnaces by using proprietary technology of Calderon in a phased approach, and Phase I was successfully completed. The project was then re-directed to the making of iron units. In 2000, U.S. Steel teamed up with Calderon for a joint effort to produce directly reduced iron with the potential of converting it into molten iron or steel consistent with the Roadmap recommendations of 1998 prepared by the Steel Industry in cooperation with the Department of Energy by using iron ore concentrate and coal as raw materials, both materials being appreciably lower in cost than using iron pellets, briquettes, sinter and coke.
Date: April 19, 2006
Creator: Calderon, Albert
Object Type: Report
System: The UNT Digital Library
2005 American Conference on Theoretical Chemistry (open access)

2005 American Conference on Theoretical Chemistry

The materials uploaded are meant to serve as final report on the funds provided by DOE-BES to help sponsor the 2005 American Conference on Theoretical Chemistry.
Date: November 19, 2006
Creator: Carter, Emily A.
Object Type: Report
System: The UNT Digital Library
Synthesis and Manipulation of Semiconductor Nanocrystals in Microfluidic Reactors (open access)

Synthesis and Manipulation of Semiconductor Nanocrystals in Microfluidic Reactors

Microfluidic reactors are investigated as a mechanism tocontrol the growth of semiconductor nanocrystals and characterize thestructural evolution of colloidal quantum dots. Due to their shortdiffusion lengths, low thermal masses, and predictable fluid dynamics,microfluidic devices can be used to quickly and reproducibly alterreaction conditions such as concentration, temperature, and reactiontime, while allowing for rapid reagent mixing and productcharacterization. These features are particularly useful for colloidalnanocrystal reactions, which scale poorly and are difficult to controland characterize in bulk fluids. To demonstrate the capabilities ofnanoparticle microreactors, a size series of spherical CdSe nanocrystalswas synthesized at high temperature in a continuous-flow, microfabricatedglass reactor. Nanocrystal diameters are reproducibly controlled bysystematically altering reaction parameters such as the temperature,concentration, and reaction time. Microreactors with finer control overtemperature and reagent mixing were designed to synthesize nanoparticlesof different shapes, such as rods, tetrapods, and hollow shells. The twomajor challenges observed with continuous flow reactors are thedeposition of particles on channel walls and the broad distribution ofresidence times that result from laminar flow. To alleviate theseproblems, I designed and fabricated liquid-liquid segmented flowmicroreactors in which the reaction precursors are encapsulated inflowing droplets suspended in an immiscible carrier fluid. The synthesisof CdSe nanocrystals in such microreactors exhibited reduced depositionand residence time …
Date: December 19, 2006
Creator: Chan, Emory Ming-Yue
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Orbital HP-Clouds for Solving Schrödinger Equation in Quantum Mechanics (open access)

Orbital HP-Clouds for Solving Schrödinger Equation in Quantum Mechanics

Solving Schroedinger equation in quantum mechanics presents a challenging task in numerical methods due to the high order behavior and high dimension characteristics in the wave functions, in addition to the highly coupled nature between wave functions. This work introduces orbital and polynomial enrichment functions to the partition of unity for solution of Schroedinger equation under the framework of HP-Clouds. An intrinsic enrichment of orbital function and extrinsic enrichment of monomial functions are proposed. Due to the employment of higher order basis functions, a higher order stabilized conforming nodal integration is developed. The proposed methods are implemented using the density functional theory for solution of Schroedinger equation. Analysis of several single and multi-electron/nucleus structures demonstrates the effectiveness of the proposed method.
Date: October 19, 2006
Creator: Chen, J. S.; Hu, W. & Puso, M. A.
Object Type: Article
System: The UNT Digital Library
Measurement of Littlest Higgs Model Parameters (open access)

Measurement of Littlest Higgs Model Parameters

The effects of the extended gauge sector present in the Littlest Higgs model in the reactions e{sup +}e{sup -} {yields} f{bar f} and e{sup +}e{sup -} {yields} Zh are examined. We find that the search reach at the 500 GeV ILC essentially covers the entire region where this model is relevant to the hierarchy proble and extends the reach of the LHC. In addition, we show that the ILC allows for an accurate determination of the model parameters, to the precision of a few percent, provided that the LHC measures the mass of the new heavy neutral gauge field.
Date: April 19, 2006
Creator: Conley, J. A.; Hewett, J. L. & Le, M. P.
Object Type: Article
System: The UNT Digital Library