Degree Department

Degree Discipline

Degree Level

52 Matching Results

Results open in a new window/tab.

Constraints on rhobar, etabar from B to K*pi (open access)

Constraints on rhobar, etabar from B to K*pi

A linear CKM relation, {bar {eta}} = tan {Phi}{sub 3/2}({bar p} - 0.24 {+-} 0.03), involving a 1{sigma} range for {Phi}{sub 3/2}, 20{sup o} < {Phi}{sub 3/2} < 115{sup o}, is obtained from B{sup 0} {yields} K*{pi} amplitudes measured recently in Dalitz plot analyses of B{sup 0} {yields} K{sup +}{pi}{sup -}{pi}{sup 0} and B{sup 0}(t) {yields} K{sub S}{pi}{sup +}{pi}{sup -}. This relation is consistent within the large error on {Phi}{sub 3/2} with other CKM constraints which are unaffected by new b {yields} s{bar q}q operators. Sensitivity of the method to a new physics contribution in the {Delta}S = {Delta}I = 1 amplitude is discussed.
Date: January 14, 2008
Creator: Gronau, Michael; Pirjol, Dan; Soni, Amarjit & Zupan, Jure
Object Type: Report
System: The UNT Digital Library

Fuel Cell Bus Evaluation Results

Presentation on the results from the DOE fuel cell bus evaluation given at the Transportation Research Board's 87th annual meeting, January 14, 2008.
Date: January 14, 2008
Creator: Eudy, L.
Object Type: Presentation
System: The UNT Digital Library
Development of Improved Iron-Aluminide Filter Tubes and Elements (open access)

Development of Improved Iron-Aluminide Filter Tubes and Elements

The purpose of this Cooperative Research and Development Agreement (CRADA) was to explore and develop advanced manufacturing techniques to fabricate sintered iron-aluminide intermetallic porous bodies used for gas filtration so as to reduce production costs while maintaining or improving performance in advanced coal gasification and combustion systems. The use of a power turbine fired with coal-derived synthesis gas requires some form of gas cleaning in order to protect turbine and downstream components from degradation by erosion, corrosion, and/or deposition. Hot-gas filtration is one form of cleaning that offers the ability to remove particles from the gases produced by gasification processes without having to substantially cool and, possibly, reheat them before their introduction into the turbine. This technology depends critically on materials durability and reliability, which have been the subject of study for a number of years.
Date: January 14, 2008
Creator: Judkins, R. R.; Sutton, T. G.; Miller, C. J. & Tortorelli, P. F.
Object Type: Report
System: The UNT Digital Library
Final Scientific Report (open access)

Final Scientific Report

NanoDynamics Inc. has undertaken a study to develop and demonstrate an anode-supported solid oxide fuel cell capable of generating a minimum of 20 W per cell on hydrogen. The cell technology will also be assed for operation on renewable hydrocarbon-based fuels such as biomass gas, as well its applicability for larger-scale power production. The project was divided into five sub-tasks, the first of which was the development and refinement of the cell manufacturing processes of gel-casting and paste extrusion for the fabrication of planar and tubular anode supports. These methods exhibited high production yields with excellent reproducibility. Using a conventional YSZ-based cell as a performance benchmark, new materials-sets and cell configurations were developed. Three prototype configurations were implemented, the best generating an average of 10 W per cell, and exhibiting excellent potential for further development and scale-up. Using a variety of techniques such as modifying the materials-set, microstructure, and cell configuration, cells with an average power output of 22.7 W were demonstrated, 13.5% in excess of the 20 W project goal. Thermal cycling was performed on such cells, and it was found that over a regime of 150 cycles (approximately 300 h), the cell power increased by 1.8%. So-called “short-stacks” …
Date: January 14, 2008
Creator: Finnerty, Caine
Object Type: Report
System: The UNT Digital Library
Simulating atmosphere flow for wind energy applications with WRF-LES (open access)

Simulating atmosphere flow for wind energy applications with WRF-LES

Forecasts of available wind energy resources at high spatial resolution enable users to site wind turbines in optimal locations, to forecast available resources for integration into power grids, to schedule maintenance on wind energy facilities, and to define design criteria for next-generation turbines. This array of research needs implies that an appropriate forecasting tool must be able to account for mesoscale processes like frontal passages, surface-atmosphere interactions inducing local-scale circulations, and the microscale effects of atmospheric stability such as breaking Kelvin-Helmholtz billows. This range of scales and processes demands a mesoscale model with large-eddy simulation (LES) capabilities which can also account for varying atmospheric stability. Numerical weather prediction models, such as the Weather and Research Forecasting model (WRF), excel at predicting synoptic and mesoscale phenomena. With grid spacings of less than 1 km (as is often required for wind energy applications), however, the limits of WRF's subfilter scale (SFS) turbulence parameterizations are exposed, and fundamental problems arise, associated with modeling the scales of motion between those which LES can represent and those for which large-scale PBL parameterizations apply. To address these issues, we have implemented significant modifications to the ARW core of the Weather Research and Forecasting model, including the …
Date: January 14, 2008
Creator: Lundquist, J K; Mirocha, J D; Chow, F K; Kosovic, B & Lundquist, K A
Object Type: Article
System: The UNT Digital Library
Cost-Effective Integration of Efficient Low-Lift Base Load Cooling Equipment (open access)

Cost-Effective Integration of Efficient Low-Lift Base Load Cooling Equipment

The long-term goal of DOE’s Commercial Buildings Integration subprogram is to develop cost-effective technologies and building practices that will enable the design and construction of net Zero Energy Buildings — commercial buildings that produce as much energy as they use on an annual basis — by 2025. To support this long-term goal, DOE further called for — as part of its FY07 Statement of Needs — the development by 2010 of “five cost-effective design technology option sets using highly efficient component technologies, integrated controls, improved construction practices, streamlined commissioning, maintenance and operating procedures that will make new and existing commercial buildings durable, healthy and safe for occupants.” In response, PNNL proposed and DOE funded a scoping study investigation of one such technology option set, low-lift cooling, that offers potentially exemplary HVAC energy performance relative to ASHRAE Standard 90.1-2004. The primary purpose of the scoping study was to estimate the national technical energy savings potential of this TOS.
Date: January 14, 2008
Creator: Jiang, Wei; Winiarski, David W.; Katipamula, Srinivas & Armstrong, Peter R.
Object Type: Report
System: The UNT Digital Library
NEW METHOD FOR REMOVAL OF SPECTRAL INTERFERENCES FOR BERYLLIUM ASSAY USING INDUCTIVELY COUPLED PLASMA ATOMIC EMISSION SPECTROMETRY (open access)

NEW METHOD FOR REMOVAL OF SPECTRAL INTERFERENCES FOR BERYLLIUM ASSAY USING INDUCTIVELY COUPLED PLASMA ATOMIC EMISSION SPECTROMETRY

Beryllium has been used widely in specific areas of nuclear technology. Frequent monitoring of air and possible contaminated surfaces in U.S Department of Energy (DOE) facilities is required to identify potential health risks and to protect DOE workers from beryllium-contaminated dust. A new method has been developed to rapidly remove spectral interferences prior to beryllium (Be) measurement by inductively-coupled plasma atomic emission spectrometry (ICP-AES). The ion exchange separation removes uranium (U), thorium (Th), niobium (Nb), vanadium (V), molybdenum (Mo), zirconium (Zr), tungsten (W), iron (Fe), chromium (Cr), cerium (Ce), erbium (Er) and titanium (Ti). A stacked column consisting of Diphonix Resin{reg_sign} and TEVA Resin{reg_sign} reduces the levels of the spectral interferences so that low level Be measurements can be performed accurately. If necessary, an additional anion exchange separation can be used for further removal of interferences, particularly chromium. The method has been tested using spiked filters, spiked wipe samples and certified reference material standards with high levels of interferences added. The method provides very efficient removal of spectral interferences with very good accuracy and precision for beryllium on filters or wipes. A vacuum box system is employed to reduce analytical time and reduce labor costs.
Date: January 14, 2008
Creator: Maxwell, S; Matthew Nelson, M; Linda Youmans, L & Maureen Bernard, M
Object Type: Article
System: The UNT Digital Library
A Linear RFQ Ion Trap for the Enriched Xenon Observatory (open access)

A Linear RFQ Ion Trap for the Enriched Xenon Observatory

The design, construction, and performance of a linear radio-frequency ion trap (RFQ) intended for use in the Enriched Xenon Observatory (EXO) are described. EXO aims to detect the neutrinoless double-beta decay of {sup 136}Xe to {sup 136}Ba. To suppress possible backgrounds EXO will complement the measurement of decay energy and, to some extent, topology of candidate events in a Xe filled detector with the identification of the daughter nucleus ({sup 136}Ba). The ion trap described here is capable of accepting, cooling, and confining individual Ba ions extracted from the site of the candidate double-beta decay event. A single trapped ion can then be identified, with a large signal-to-noise ratio, via laser spectroscopy.
Date: January 14, 2008
Creator: Flatt, B.; Green, M.; Wodin, J.; DeVoe, R.; Fierlinger, P.; Gratta, G. et al.
Object Type: Article
System: The UNT Digital Library
Comment on ``Experimental Free Energy Reconstruction From Single-Molecule Force Spectroscopy Using Jarzynski's Equality'' (open access)

Comment on ``Experimental Free Energy Reconstruction From Single-Molecule Force Spectroscopy Using Jarzynski's Equality''

Harris, Song and Kiang [1] (HSK) describe their results on reconstructing the free energy profiles for both the stretch of the titin polymer, and the unfolding of an individual I27 domain. The new finding reported in [1] is the measurement of the free energy barrier (or activation energy) to unfolding the I27 domain. Due to a misinterpretation of the mechanics involved, the free energy surface (and thus the energy barrier) to unfolding the I27 domain was not measured.
Date: January 14, 2008
Creator: Friddle, R. W.
Object Type: Article
System: The UNT Digital Library
Chamonium Spectroscopy at BaBar (open access)

Chamonium Spectroscopy at BaBar

The charmonium-like states, Y(4260), Y(4350), produced via initial state radiation, as well as the X(3872), and Y(3940), produced in B meson decays from the BABAR B-factory are reviewed. These mesons do not seem consistent with conventional charmonium models, and several alternate hypotheses have been proposed to explain these new discoveries.
Date: January 14, 2008
Creator: Mokhtar, Arafat Gabareen & U., /Colorado State
Object Type: Article
System: The UNT Digital Library
Investigation of Radar Propagation in Buildings: A 10 Billion Element Cartesian-Mesh FETD Simulation (open access)

Investigation of Radar Propagation in Buildings: A 10 Billion Element Cartesian-Mesh FETD Simulation

In this paper large scale full-wave simulations are performed to investigate radar wave propagation inside buildings. In principle, a radar system combined with sophisticated numerical methods for inverse problems can be used to determine the internal structure of a building. The composition of the walls (cinder block, re-bar) may effect the propagation of the radar waves in a complicated manner. In order to provide a benchmark solution of radar propagation in buildings, including the effects of typical cinder block and re-bar, we performed large scale full wave simulations using a Finite Element Time Domain (FETD) method. This particular FETD implementation is tuned for the special case of an orthogonal Cartesian mesh and hence resembles FDTD in accuracy and efficiency. The method was implemented on a general-purpose massively parallel computer. In this paper we briefly describe the radar propagation problem, the FETD implementation, and we present results of simulations that used over 10 billion elements.
Date: January 14, 2008
Creator: Stowell, M. L.; Fasenfest, B. J. & White, D. A.
Object Type: Article
System: The UNT Digital Library
A Time Projection Chamber for precision 239Pu(n,f) cross section measurement (open access)

A Time Projection Chamber for precision 239Pu(n,f) cross section measurement

High precision measurements of the {sup 239}Pu(n,f) cross section have been identified as important for the Global Nuclear Energy Partnership (GNEP) and other programs. Currently the uncertainty on this cross section is of the order 2-3% for neutron energies below 14 MeV and the goal is to reduce this to less than 1%. The Time Projection Chamber (TPC) has been identified as a possible tool to make this high precision measurement.
Date: January 14, 2008
Creator: Heffner, M
Object Type: Article
System: The UNT Digital Library
Discrimination Report: A Multisensor system for detection andcharacterization of UXO, ESTCP Project MM-0437, (open access)

Discrimination Report: A Multisensor system for detection andcharacterization of UXO, ESTCP Project MM-0437,

The Berkeley UXO Discriminator (BUD) is an optimally designed active electromagnetic system that not only detects but also characterizes UXO. The performance of the system is governed by a target size-depth curve. BUD was designed to detect UXO in the 20 mm to 155 mm size range for depths between 0 and 1.5 m, and to characterize them in a depth range from 0 to 1.1 m. The system incorporates three orthogonal transmitters and eight pairs of differenced receivers. Eight receiver coils are placed horizontally along the two diagonals of the upper and lower planes of the two horizontal transmitter loops. These receiver coil pairs are located on symmetry lines through the center of the system and each pair sees identical fields during the on-time of the pulse in all of the transmitter coils. They are wired in opposition to produce zero output during the on-time of the pulses in three orthogonal transmitters. Moreover, this configuration dramatically reduces noise in the measurements by canceling the background electromagnetic fields (these fields are uniform over the scale of the receiver array and are consequently nulled by the differencing operation), and by canceling the noise contributed by the tilt motion of the receivers …
Date: January 14, 2008
Creator: Gasperikova, Erika; Smith, J. Torquil; Morrison, H.Frank & Becker,Alex
Object Type: Report
System: The UNT Digital Library
Neutralizing Carbonic Acid in Deep Carbonate Strata below the North Atlantic (open access)

Neutralizing Carbonic Acid in Deep Carbonate Strata below the North Atlantic

Carbon dioxide injection into deep sea sediments below 2700 m water depth and a few hundred meters to fifteen hundred meters deep in the sediment column may provide permanent geologic storage by gravitational trapping. At high pressures and low temperatures common in deep sea sediments a few hundred meters below sea floor, CO{sub 2} will be in its liquid phase and will be denser than the overlying pore fluid. The lower density of the pore fluid provides a cap to the denser CO{sub 2} and ensures gravitational trapping in the short term. The overall storage capacity for CO{sub 2} in such deep sea formations below the ocean floor is primarily determined by the permeability, and will vary with seafloor depth, geothermal gradient, porosity, and pore water salinity. Furthermore, the dissemination of the injected CO{sub 2} in the sediments and potential chemical reactions between CO{sub 2}, pore fluid and sediments will define its fate in the storage reservoir. The main objectives of our research was to evaluate the potential for sub-seabed CO{sub 2} storage in deep sea sediments using a range of approaches including experiments, permeability analysis, and modeling. Over the course of the three-year award, our results support an important …
Date: January 14, 2008
Creator: Lackner, Klaus; Harvey, Charles & Watson, Bruce
Object Type: Report
System: The UNT Digital Library
The Wild and Scenic Rivers Act and Federal Water Rights (open access)

The Wild and Scenic Rivers Act and Federal Water Rights

This report discusses federal authority over water, and federal “reserved” and non-reserved water rights. It discusses water rights under the Wild and Scenic Rivers Act and water rights provisions within specific designations.
Date: January 14, 2008
Creator: Brougher, Cynthia
Object Type: Report
System: The UNT Digital Library
The Endangered Species Act and Claims of Property Rights “Takings (open access)

The Endangered Species Act and Claims of Property Rights “Takings

This report discusses Endangered Species Act (ESA) that has long been one of the major flash points in the “property rights” debate. This report first outlines the ESA provisions most relevant to the act's impacts on private property, then surveys the major ESA-relevant principles of Fifth Amendment takings law, and finally discusses the court decisions adjudicating whether government measures based on the ESA effect a taking of property under the Fifth Amendment.
Date: January 14, 2008
Creator: Meltz, Robert
Object Type: Report
System: The UNT Digital Library
Arms Sales: Congressional Review Process (open access)

Arms Sales: Congressional Review Process

This report reviews the process and procedures that currently apply to congressional consideration of foreign arms sales proposed by the President.
Date: January 14, 2008
Creator: Grimmett, Richard F.
Object Type: Report
System: The UNT Digital Library
North Korea: Terrorism List Removal? (open access)

North Korea: Terrorism List Removal?

None
Date: January 14, 2008
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Social Security: The Windfall Elimination Provision (WEP) (open access)

Social Security: The Windfall Elimination Provision (WEP)

This report discusses the windfall elimination provision (WEP), which reduces the Social Security benefits of workers who also have pension benefits from employment not covered by Social Security. Its purpose is to remove an advantage these workers would otherwise receive because of Social Security’s benefit formula that favors workers with smaller amounts of Social Security-covered career earnings. Opponents contend that the provision is basically imprecise and often unfair.
Date: January 14, 2008
Creator: Haltzel, Laura
Object Type: Report
System: The UNT Digital Library
Instances of Use of United States Armed Forces Abroad, 1798-2007 (open access)

Instances of Use of United States Armed Forces Abroad, 1798-2007

None
Date: January 14, 2008
Creator: unknown
Object Type: Report
System: The UNT Digital Library
The Gulf Security Dialogue and Related Arms Sale Proposals (open access)

The Gulf Security Dialogue and Related Arms Sale Proposals

This report describes the structure and objectives of the Gulf Security Dialogue; briefly assesses its regional implications; summarizes related proposed arms sales; provides an overview of congressional notification and review procedures; and analyzes recent related activity in the Administration and Congress.
Date: January 14, 2008
Creator: Blanchard, Christopher M. & Grimmett, Richard R.
Object Type: Report
System: The UNT Digital Library
Court Security Improvement Act of 2007: A Legal Analysis of Public Law 110-177 (H.R. 660 and S. 378) (open access)

Court Security Improvement Act of 2007: A Legal Analysis of Public Law 110-177 (H.R. 660 and S. 378)

This report discusses the proposals of the Court Security Improvement Act of 2007. It consists of amendments to existing federal criminal law.
Date: January 14, 2008
Creator: Doyle, Charles
Object Type: Report
System: The UNT Digital Library
[Deadline Extended for TDNA Award Contest] (open access)

[Deadline Extended for TDNA Award Contest]

A notice from the Texas Daily Newspaper Associations, which states that they have extended the deadline for the award contest to January 25, 2008. The document requests that TDNA members pass the notice along to publishers, editors, copy editors, sportswriters, marketing and promotion staff who have worked hard to promote their newspapers to the community that the deadline has extended. The document also details the type of awards that are available. Winners will receive awards at the 2008 TDNA Annual Meeting on Monday, March 10, 2008 at the Westin Riverwalk Hotel in San Antonio.
Date: January 14, 2008
Creator: Texas Daily Newspaper Association
Object Type: Text
System: The UNT Digital Library
The Theory of Variances in Equilibrium Reconstruction (open access)

The Theory of Variances in Equilibrium Reconstruction

The theory of variances of equilibrium reconstruction is presented. It complements existing practices with information regarding what kind of plasma profiles can be reconstructed, how accurately, and what remains beyond the abilities of diagnostic systems. The #27;σ-curves, introduced by the present theory, give a quantitative assessment of quality of effectiveness of diagnostic systems in constraining equilibrium reconstructions. The theory also suggests a method for aligning the accuracy of measurements of different physical nature.
Date: January 14, 2008
Creator: Leonid E. Zakharov, Jerome Lewandowski, Elizabeth L. Foley, Fred M. Levinton, Howard Y. Yuh, Vladimir Drozdov, and Darren McDonald
Object Type: Report
System: The UNT Digital Library