QUANTITATIVE ANALYSES OF THE SEVERITY OF ATTACK ON CREVICE CORROSION SURFACES (open access)

QUANTITATIVE ANALYSES OF THE SEVERITY OF ATTACK ON CREVICE CORROSION SURFACES

None
Date: December 19, 2005
Creator: /a, n
Object Type: Article
System: The UNT Digital Library
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
Education Vouchers: Constitutional Issues and Cases (open access)

Education Vouchers: Constitutional Issues and Cases

This report details the constitutional standards that currently apply to indirect aid programs and summarizes all of the pertinent state and federal court decisions, including the Ohio case that will be heard by the Supreme Court. On September 25, 2001, the Supreme Court agreed to review a case raising the controversial issue of the constitutionality of education vouchers. In Zelman v. Simmons-Harris the Sixth Circuit held Ohio’s Pilot Scholarship Program, which provided up to $2500 to help low-income students in Cleveland’s public schools attend private schools in the city, to violate the establishment of religion clause of the First Amendment.
Date: December 19, 2000
Creator: Ackerman, David M.
Object Type: Report
System: The UNT Digital Library
Solvation! (open access)

Solvation!

This dissertation consists of two closely related parts: theory development and coding of correlation effects in a model potential for solvation, and study of solvent effects on chemical reactions and processes. The effective fragment potential (EFP) method has been re-parameterized, using density functional theory (DFT), more specifically, the B3LYP functional. The DFT based EFP method includes short-range correlation effects; hence it is a first step in incorporating the treatment of correlation in the EFP solvation model. In addition, the gradient of the charge penetration term in the EFP model was derived and coded. The new method has been implemented in the electronic structure code GAMESS and is in use. Formulas for the dynamic dipole polarizability, C{sub 6} dispersion coefficient and dispersion energy were derived and coded as a part of a treatment of the dispersion interactions in the general solvation model, EFP2. Preliminary results are in good agreement with experimental and other theoretical data. The DFT based EFP (EFP1/DFT) method was used in the study of microsolvation effects on the S{sub N}2 substitution reaction, between chloride and methyl bromide. Changes in the central barrier, for several lowest lying isomers of the systems with one, two, three and four waters, were …
Date: December 19, 2004
Creator: Adamovic, Ivana
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Membership of the 107th Congress: A Profile (open access)

Membership of the 107th Congress: A Profile

None
Date: December 19, 2001
Creator: Amer, Mildred L.
Object Type: Report
System: The UNT Digital Library
Polymer OLED White Light Development Program (open access)

Polymer OLED White Light Development Program

OSRAM Opto Semiconductors (OSRAM) successfully completed development, fabrication and characterization of the large area, polymer based white light OLED prototype at their OLED Research and Development (R&D) facility in San Jose, CA. The program, funded by the Department of Energy (DOE), consisted of three key objectives: (1) Develop new polymer materials and device architectures--in order to improve the performance of organic light emitters. (2) Develop processing techniques--in order to demonstrate and enable the manufacturing of large area, white light and color tunable, solid state light sources. (3) Develop new electronics and driving schemes for organic light sources, including color-tunable light sources. The key performance goals are listed. A world record efficiency of 25 lm/W was established for the solution processed white organic device from the significant improvements made during the project. However, the challenges to transfer this technology from an R&D level to a large tile format such as, the robustness of the device and the coating uniformity of large area panels, remain. In this regard, the purity and the blend nature of the materials are two factors that need to be addressed in future work. During the first year, OSRAM's Materials and Device group (M&D) worked closely with the …
Date: December 19, 2005
Creator: Antoniadis, Homer; Choong, Vi-En; Choulis, Stelios; Cumpston, Brian; Gupta, Rahul; Mathai, Mathew et al.
Object Type: Report
System: The UNT Digital Library
Search for Decays of B0 Mesons into e+e-, \mu+\mu-, and e+-\mu+- Final States (open access)

Search for Decays of B0 Mesons into e+e-, \mu+\mu-, and e+-\mu+- Final States

The authors present a search for the decays B{sup 0} {yields} e{sup +}e{sup -}, B{sup 0} {yields} {mu}{sup +}{mu}{sup -} and B{sup 0} {yields} e{sup {+-}}{mu}{sup {-+}} using data collected with the BABAR detector at the PEP-II e{sup +}e{sup -} collider at SLAC. Using a dataset corresponding to 384 x 10{sup 6} B{bar B} pairs, they do not find evidence of any of the three decay modes. They obtain upper limit on the branching fractions, at 90% confidence level, of {Beta}(B{sup 0} {yields} e{sup +}e{sup -}) < 11.3 x 10{sup -8}, {Beta}(B{sup 0} {yields} {mu}{sup +}{mu}{sup -}) < 5.2 x 10{sup -8}, and {Beta}(B{sup 0} {yields} e{sup {+-}}{mu}{sup {-+}}) < 9.2 x 10{sup -8}.
Date: December 19, 2007
Creator: Aubert, B.
Object Type: Article
System: The UNT Digital Library
Search for the Rare Quark-annihilation Decays B->Ds(*)Phi (open access)

Search for the Rare Quark-annihilation Decays B->Ds(*)Phi

We report on searches for B{sup -} {yields} D{sub s}{sup -} {phi} and B{sup -} {yields} D*{sub s}{sup -} {phi}. In the context of the Standard Model, these decays are expected to be highly suppressed since they proceed through annihilation of the b and {bar u} quarks in the B{sup -} meson. Our results are based on 234 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at SLAC. We find no evidence for these decays, and we set Bayesian 90% confidence level upper limits on the branching fractions {Beta}(B{sup -} {yields} D{sub s}{sup -}{phi}) < 1.9 x 10{sup -6} and {Beta}(B{sup -} {yields} D*{sub s}{sup -} {phi}) < 1.2 x 10{sup -5}. These results are consistent with Standard Model expectations.
Date: December 19, 2005
Creator: Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J. P. et al.
Object Type: Article
System: The UNT Digital Library
Gas Sensors Based on Ceramic p-n Heterocontacts (open access)

Gas Sensors Based on Ceramic p-n Heterocontacts

Ceramic p-n heterocontacts based on CuO/ZnO were successfully synthesized and a systematic study of their hydrogen sensitivity was conducted. The sensitivity and response rates of CuO/ZnO sensors were studied utilizing current-voltage, current-time, and impedance spectroscopy measurements. The heterocontacts showed well-defined rectifying characteristics and were observed to detect hydrogen via both dc and ac measurements. Surface coverage data were derived from current-time measurements which were then fit to a two-site Langmuir adsorption model quite satisfactorily. The fit suggested that there should be two energetically different adsorption sites in the system. The heterocontacts were doped in an attempt to increase the sensitivity and the response rate of the sensor. First, the effects of doping the p-type (CuO) on the sensor characteristics were investigated. Doping the p-type CuO with both acceptor and isovalent dopants greatly improved the hydrogen sensitivity. The sensitivity of pure heterocontact observed via I-V measurements was increased from {approx}2.3 to {approx}9.4 with Ni doping. Dopants also enhanced the rectifying characteristics of the heterocontacts. Small amounts of Li addition were shown to decrease the reverse bias (saturation) current to 0.2 mA at a bias level of -5V. No unambiguous trends were observed between the sensitivity, the conductivity, and the density of …
Date: December 19, 2004
Creator: Aygun, Seymen Murat
Object Type: Thesis or Dissertation
System: The UNT Digital Library
The National Forest System Roadless Areas Initiative (open access)

The National Forest System Roadless Areas Initiative

None
Date: December 19, 2002
Creator: Baldwin, Pamela
Object Type: Report
System: The UNT Digital Library
Strategic Petroleum Reserve (open access)

Strategic Petroleum Reserve

This report includes information regarding strategic petroleum reserve. Background and analysis, purchases of crude oil, and drawdown of the reserve are among topics discussed in this report.
Date: December 19, 2003
Creator: Bamberger, Robert
Object Type: Report
System: The UNT Digital Library
Bunch Length Measurements at the ATF Damping Ring in April 2000 (open access)

Bunch Length Measurements at the ATF Damping Ring in April 2000

We want to accurately know the energy spread and bunch length dependence on current in the ATF damping ring. One reason is to know the strength of the impedance: From the energy spread measurements we know whether or not we are above the threshold to the microwave instability, and from the energy spread and bunch length measurements we find out the extent of potential-well bunch lengthening (PWBL). Another reason for these measurements is to help in our understanding of the intra-beam scattering (IBS) effect in the ATF. The ATF as it is now, running below design energy and with the wigglers turned off, is strongly affected by IBS. To check for consistency with IBS theory of, for example, the measured vertical beam size, we need to know all dimensions of the beam, including the longitudinal one. But beyond this practical reason for studying IBS, IBS is currently a hot research topic at many accelerators around the world (see e.g. Ref. [1]), and the effect in actual machines is not well understood. Typically, when comparing theory with measurements fudge factors are needed to get agreement (see e.g. Ref. [1]). With its strong IBS effect, the ATF is an ideal machine for …
Date: December 19, 2005
Creator: Bane, K. L. F.; Naito, T.; Okugi, T. & Urakawa, J.
Object Type: Report
System: The UNT Digital Library
BSE (“Mad Cow Disease”): A Brief Overview (open access)

BSE (“Mad Cow Disease”): A Brief Overview

This report provides background on appearance of BSE(bovine spongiform encephalopathy or "mad cow disease") in North America.
Date: December 19, 2006
Creator: Becker, Geoffrey S.
Object Type: Report
System: The UNT Digital Library
The "Farm Bill" in Brief (open access)

The "Farm Bill" in Brief

Federal farm support, food assistance, agricultural trade, marketing, and rural development policies are governed by a variety of separate laws. Many of these laws periodically have been evaluated, revised, and renewed through an omnibus, multi-year farm bill. This report discusses the "farm bill" and it's components.
Date: December 19, 2005
Creator: Becker, Geoffrey S.
Object Type: Report
System: The UNT Digital Library
Food Safety on the Farm: Federal Programs and Selected Proposals (open access)

Food Safety on the Farm: Federal Programs and Selected Proposals

This report discusses bills introduced into the 110th Congress pertaining to food safety that could affect farmers and ranchers. Several of these bills would expressly have required enforceable on-farm safety standards. Others that focused primarily on post-harvest food safety measures nonetheless might have led to changes in on-farm practices if the regulated sectors (handlers and processors of agricultural products) placed new demands on their suppliers in order to comply. Similar proposals are re-emerging in the 111th Congress, where food safety reform is expected to be on the agenda.
Date: December 19, 2008
Creator: Becker, Geoffrey S.
Object Type: Report
System: The UNT Digital Library
On-chip single-copy real-time reverse-transcription PCR in isolated picoliter droplets (open access)

On-chip single-copy real-time reverse-transcription PCR in isolated picoliter droplets

The first lab-on-chip system for picoliter droplet generation and RNA isolation, followed by reverse transcription, and PCR amplification with real-time fluorescence detection in the trapped droplets has been developed. The system utilized a shearing T-junction in a fused silica device to generate a stream of monodisperse picoliter-scale droplets that were isolated from the microfluidic channel walls and each other by the oil phase carrier. An off-chip valving system stopped the droplets on-chip, allowing thermal cycling for reverse transcription and subsequent PCR amplification without droplet motion. This combination of the established real-time reverse transcription-PCR assay with digital microfluidics is ideal for isolating single-copy RNA and virions from a complex environment, and will be useful in viral discovery and gene-profiling applications.
Date: December 19, 2007
Creator: Beer, N. R.; Wheeler, E.; Lee-Houghton, L.; Watkins, N.; Nasarabadi, S.; Hebert, N. et al.
Object Type: Article
System: The UNT Digital Library
Oxidation Behavior and Chlorination Treatment to Improve Oxidation Resistance of Nb-Mo-Si-B Alloys (open access)

Oxidation Behavior and Chlorination Treatment to Improve Oxidation Resistance of Nb-Mo-Si-B Alloys

This thesis is written in an alternate format. The thesis is composed of a general introduction, two original manuscripts, and a general conclusion. References cited within each chapter are given at the end of each chapter. The general introduction starts with the driving force behind this research, and gives an overview of previous work on boron doped molybdenum silicides, Nb/Nb{sub 5}Si{sub 3} composites, boron modified niobium silicides and molybdenum niobium silicides. Chapter 2 focuses on the oxidation behavior of Nb-Mo-Si-B alloys. Chapter 3 contains studies on a novel chlorination technique to improve the oxidation resistance of Nb-Mo-Si-B alloys. Chapter 4 summarizes the important results in this study.
Date: December 19, 2004
Creator: Behrani, Vikas
Object Type: Thesis or Dissertation
System: The UNT Digital Library
How Long Can the Defense Department Finance FY2008 Operations in Advance of Supplemental Appropriations? (open access)

How Long Can the Defense Department Finance FY2008 Operations in Advance of Supplemental Appropriations?

None
Date: December 19, 2007
Creator: Belasco, Amy; Daggett, Stephen & Towell, Pat
Object Type: Report
System: The UNT Digital Library
General Features of Supersymmetric Signals at the ILC: Solving the LHC Inverse Problem (open access)

General Features of Supersymmetric Signals at the ILC: Solving the LHC Inverse Problem

We examine whether the {radical}s = 500 GeV International Linear Collider with 80% electron beam polarization can be used to solve the LHC Inverse Problem within the framework of the MSSM. We investigate 242 points in the MSSM parameter space, which we term models, that correspond to the 162 pairs of models found by Arkani-Hamed et al. to give indistinguishable signatures at the LHC. We first determine whether the production of the various SUSY particles is visible above the Standard Model background for each of these parameter space points, and then make a detailed comparison of their various signatures. Assuming an integrated luminosity of 500 fb{sup -1}, we find that only 82 out of 242 models lead to visible signatures of some kind with a significance {ge} 5 and that only 57(63) out of the 162 model pairs are distinguishable at 5(3){sigma}. Our analysis includes PYTHIA and CompHEP SUSY signal generation, full matrix element SM backgrounds for all 2 {yields} 2, 2 {yields} 4, and 2 {yields} 6 processes, ISR and beamstrahlung generated via WHIZARD/GuineaPig, and employs the fast SiD detector simulation org.lcsim.
Date: December 19, 2007
Creator: Berger, Carola F.; Gainer, James S.; Hewett, JoAnne L.; Lillie, Ben & Rizzo, Thomas G.
Object Type: Article
System: The UNT Digital Library
Comparison of AEO 2006 Natural Gas Price Forecast to NYMEX FuturesPrices (open access)

Comparison of AEO 2006 Natural Gas Price Forecast to NYMEX FuturesPrices

On December 12, 2005, the reference case projections from ''Annual Energy Outlook 2006'' (AEO 2006) were posted on the Energy Information Administration's (EIA) web site. We at LBNL have in the past compared the EIA's reference case long-term natural gas price forecasts from the AEO series to contemporaneous natural gas prices that can be locked in through the forward market, with the goal of better understanding fuel price risk and the role that renewables play in mitigating such risk (see, for example, http://eetd.lbl.gov/ea/EMS/reports/53587.pdf or http://eetd.lbl.gov/ea/ems/reports/54751.pdf). As such, we were curious to see how the latest AEO gas price forecast compares to the NYMEX natural gas futures strip. This brief memo presents our findings. As a refresher, our past work in this area has found that over the past five years, forward natural gas contracts (with prices that can be locked in--e.g., gas futures, swaps, and physical supply) have traded at a premium relative to contemporaneous long-term reference case gas price forecasts from the EIA. As such, we have concluded that, over the past five years at least, levelized cost comparisons of fixed-price renewable generation with variable price gas-fired generation that have been based on AEO natural gas price forecasts (rather …
Date: December 19, 2005
Creator: Bolinger, Mark & Wiser, Ryan
Object Type: Report
System: The UNT Digital Library
F/A-22 Raptor (open access)

F/A-22 Raptor

This report is categorized into three categories: (I) Introduction, (II) Key Issue and (III) Congressional Action. It also consist a figure for F-22A Weapons Loadout.
Date: December 19, 2008
Creator: Bolkcom, Christopher
Object Type: Report
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
High-Pressure Catalytic Reactions of C6 Hydrocarbons on PlatinumSingle-Crystals and nanoparticles: A Sum Frequency Generation VibrationalSpectroscopic and Kinetic Study (open access)

High-Pressure Catalytic Reactions of C6 Hydrocarbons on PlatinumSingle-Crystals and nanoparticles: A Sum Frequency Generation VibrationalSpectroscopic and Kinetic Study

Catalytic reactions of cyclohexene, benzene, n-hexane, 2-methylpentane, 3-methylpentane, and 1-hexene on platinum catalysts were monitored in situ via sum frequency generation (SFG) vibrational spectroscopy and gas chromatography (GC). SFG is a surface specific vibrational spectroscopic tool capable of monitoring submonolayer coverages under reaction conditions without gas-phase interference. SFG was used to identify the surface intermediates present during catalytic processes on Pt(111) and Pt(100) single-crystals and on cubic and cuboctahedra Pt nanoparticles in the Torr pressure regime and at high temperatures (300K-450K). At low pressures (<10{sup -6} Torr), cyclohexene hydrogenated and dehydrogenates to form cyclohexyl (C{sub 6}H{sub 11}) and {pi}-allyl C{sub 6}H{sub 9}, respectively, on Pt(100). Increasing pressures to 1.5 Torr form cyclohexyl, {pi}-allyl C{sub 6}H{sub 9}, and 1,4-cyclohexadiene, illustrating the necessity to investigate catalytic reactions at high-pressures. Simultaneously, GC was used to acquire turnover rates that were correlated to reactive intermediates observed spectroscopically. Benzene hydrogenation on Pt(111) and Pt(100) illustrated structure sensitivity via both vibrational spectroscopy and kinetics. Both cyclohexane and cyclohexene were produced on Pt(111), while only cyclohexane was formed on Pt(100). Additionally, {pi}-allyl c-C{sub 6}H{sub 9} was found only on Pt(100), indicating that cyclohexene rapidly dehydrogenates on the (100) surface. The structure insensitive production of cyclohexane was found …
Date: December 19, 2007
Creator: Bratlie, Kaitlin
Object Type: Thesis or Dissertation
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