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Measurement of CP Content and Time-Dependent CP Violation in B0 --> D*+D*- Decays

Description: This dissertation presents the measurement of the Cp-odd fraction and time-dependent CP violation parameters for the B{sup 0} {yields} D*{sup +} D*{sup -} decay. These results are based on the full BABAR dataset of (467 {+-} 5) x 10{sup 6} B{bar B} pairs collected at the PEP-II B Factory at the Stanford Linear Accelerator Center. An angular analysis finds that the CP-odd fraction of the B{sup 0} {yields} D*{sup +} D*{sup -} decay is R{sub {perpendicular}} = 0.158 {+-} 0.028 {+-} 0.006, where th… more
Date: January 5, 2009
Creator: Anderson, Jacob M.
Partner: UNT Libraries Government Documents Department
open access

Intermittent Turbulence in the Very Stable Ekman Layer

Description: INTERMITTENT TURBULENCE IN THE VERY STABLE EKMAN LAYER This study describes a Direct Numerical Simulation (DNS) of a very stable Ekman layer in which a constant downward heat flux is applied at the lower boundary, thus cooling the fluid above. Numerical experiments were performed in which the strength of the imposed heat flux was varied. For downward heat fluxes above a certain critical value the turbulence becomes intermittent and, as the heat flux increases beyond this value, the flow tends t… more
Date: January 5, 2001
Creator: Barnard, James C.
Partner: UNT Libraries Government Documents Department
open access

Magnetic Tools for Lab-on-a-chip Technologies

Description: This study establishes a set of magnetics-based tools that have been integrated with microfluidic systems. The overall impact of the work begins to enable the rapid and efficient manipulation and detection of magnetic entities such as particles, picoliter-sized droplets, or bacterial cells. Details of design, fabrication, and theoretical and experimental assessments are presented. The manipulation strategy has been demonstrated in the format of a particle diverter, whereby micron-sized particle… more
Date: August 5, 2006
Creator: Pekas, Nikola Slobodan
Partner: UNT Libraries Government Documents Department
open access

Local chromatin structure of heterochromatin regulates repeatedDNA stability, nucleolus structure, and genome integrity

Description: Heterochromatin constitutes a significant portion of the genome in higher eukaryotes; approximately 30% in Drosophila and human. Heterochromatin contains a high repeat DNA content and a low density of protein-encoding genes. In contrast, euchromatin is composed mostly of unique sequences and contains the majority of single-copy genes. Genetic and cytological studies demonstrated that heterochromatin exhibits regulatory roles in chromosome organization, centromere function and telomere protectio… more
Date: May 5, 2007
Creator: Peng, Jamy C.
Partner: UNT Libraries Government Documents Department
open access

Viscosity of aqueous and cyanate ester suspensions containing alumina nanoparticles

Description: The viscosities of both aqueous and cyanate ester monomer (BECy) based suspensions of alumina nanoparticle were studied. The applications for these suspensions are different: aqueous suspensions of alumina nanoparticles are used in the production of technical ceramics made by slip casting or tape casting, and the BECy based suspensions are being developed for use in an injection-type composite repair resin. In the case of aqueous suspensions, it is advantageous to achieve a high solids content … more
Date: August 5, 2009
Creator: Lawler, Katherine
Partner: UNT Libraries Government Documents Department
open access

A texture-based framework for improving CFD data visualization in a virtual environment

Description: In the field of computational fluid dynamics (CFD) accurate representations of fluid phenomena can be simulated hut require large amounts of data to represent the flow domain. Most datasets generated from a CFD simulation can be coarse, {approx}10,000 nodes or cells, or very fine with node counts on the order of 1,000,000. A typical dataset solution can also contain multiple solutions for each node, pertaining to various properties of the flow at a particular node. Scalar properties such as den… more
Date: May 5, 2005
Creator: Bivins, Gerrick O'Ron
Partner: UNT Libraries Government Documents Department
open access

Mechanistic Study of Oxygen Atom Transfer Catalyzed by Rhenium Compounds

Description: Two ionic and one neutral methyl(oxo)rhenium(V) compounds were synthesized and structurally characterized. They were compared in reactivity towards the ligands triphenylphosphane, pyridines, pyridine N-oxides. Assistance from Broensted bases was found on ligand displacement of ionic rhenium compounds as well as nucleophile assistance on oxidation of all compounds. From the kinetic data, crystal structures, and an analysis of the intermediates, a structural formula of PicH{sup +}3{sup -} and mec… more
Date: August 5, 2003
Creator: Shan, Xiaopeng
Partner: UNT Libraries Government Documents Department
open access

Development of high Sensitivity Materials for Applications in Magneto-Mechanical Torque Sensor

Description: The Matteucci effect, which mainly manifests itself as the change of magnetization of a material with torsional stress, is currently of great technological interest because of the search for magnetic torque sensors. Magnetic torque sensors are important to future improvements of automobiles and industrial robots. It is well known that the magnetic state of a material depends on both the external magnetic field and external stress which causes strain and change in magnetization of the material. … more
Date: August 5, 2003
Creator: Shen, Yuping
Partner: UNT Libraries Government Documents Department
open access

Generalized Portable SHMEM Library for High Performance Computing

Description: This dissertation describes the efforts to design and implement the Generalized Portable SHMEM library, GPSHMEM, as well as supplementary tools. There are two major components of the GPSHMEM project: the GPSHMEM library itself and the Fortran 77 source-to-source translator. The rest of this thesis is divided into two parts. Part I introduces the shared memory model and the distributed shared memory model. It explains the motivation behind GPSHMEM and presents its functionality and performance r… more
Date: August 5, 2003
Creator: Parzyszek, Krzysztof
Partner: UNT Libraries Government Documents Department
open access

Device Optimization and Transient Electroluminescence Studies of Organic light Emitting Devices

Description: Organic light emitting devices (OLEDs) are among the most promising for flat panel display technologies. They are light, bright, flexible, and cost effective. And while they are emerging in commercial product, their low power efficiency and long-term degradation are still challenging. The aim of this work was to investigate their device physics and improve their performance. Violet and blue OLEDs were studied. The devices were prepared by thermal vapor deposition in high vacuum. The combinatori… more
Date: August 5, 2003
Creator: Zou, Lijuan
Partner: UNT Libraries Government Documents Department
open access

Investigations of the Electronic Properties and Surface Structures of Aluminium-Rich Quasicrystalline Alloys

Description: The work presented in this dissertation has investigated three distinct areas of interest in the field of quasicrystals: bulk structure, transport properties, and electronic structure. First, they have described the results of a study which explored the fundamental interactions between the atomic species of the icosahedral Al-Pd-Mn quasicrystal. The goal of this work was to determine whether the pseudo-MacKay or Bergman type clusters have a special stability or are merely a geometric coincidenc… more
Date: August 5, 2003
Creator: Barrow, Jason A.
Partner: UNT Libraries Government Documents Department
open access

A Model for the Behavior of Magnetic Tunnel Junctions

Description: A magnetic tunnel junction is a device that changes its electrical resistance with a change in an applied magnetic field. A typical junction consists of two magnetic electrodes separated by a nonmagnetic insulating layer. The magnetizations of the two electrodes can have two possible extreme configurations, parallel and antiparallel. The antiparallel configuration is observed to have the higher measured resistance and the parallel configuration has the lower resistance. To switch between these … more
Date: August 5, 2003
Creator: Baker, Bryan John
Partner: UNT Libraries Government Documents Department
open access

High-Throughput Genetic Analysis and Combinatorial Chiral Separations Based on Capillary Electrophoresis

Description: Capillary electrophoresis (CE) offers many advantages over conventional analytical methods, such as speed, simplicity, high resolution, low cost, and small sample consumption, especially for the separation of enantiomers. However, chiral method developments still can be time consuming and tedious. They designed a comprehensive enantioseparation protocol employing neutral and sulfated cyclodextrins as chiral selectors for common basic, neutral, and acidic compounds with a 96-capillary array syst… more
Date: August 5, 2003
Creator: Zhong, Wenwan
Partner: UNT Libraries Government Documents Department
open access

VE-Suite: Coupling Visualization and Computational Environments to Support on-the-fly Engineering Design

Description: CFD (Computational Fluid Dynamics) is a widely used technique in engineering design field. It uses mathematical methods to simulate and predict flow characteristics in a certain physical space. Since the numerical result of CFD computation is very hard to understand, VR (virtual reality) and data visualization techniques are introduced into CFD post-processing to improve the understandability and functionality of CFD computation. In many cases CFD datasets are very large (multi-gigabytes), and … more
Date: August 5, 2003
Creator: Li, Song
Partner: UNT Libraries Government Documents Department
open access

Long-Term Cyclic Oxidation Behavior of Wrought Commercial Alloys at High Temperatures

Description: The oxidation resistance of a high-temperature alloy is dependent upon sustaining the formation of a protective scale, which is strongly related to the alloying composition and the oxidation condition. The protective oxide scale only provides a finite period of oxidation resistance owing to its eventual breakdown, which is especially accelerated under thermal cycling conditions. This current study focuses on the long-term cyclic oxidation behavior of a number of commercial wrought alloys. The a… more
Date: August 5, 2003
Creator: Li, Bingtao
Partner: UNT Libraries Government Documents Department
open access

Miniaturized Analytical Platforms From Nanoparticle Components: Studies in the Construction, Characterization, and High-Throughput Usage of These Novel Architectures

Description: The scientific community has recently experienced an overall effort to reduce the physical size of many experimental components to the nanometer size range. This size is unique as the characteristics of this regime involve aspects of pure physics, biology, and chemistry. One extensively studied example of a nanometer sized experimental component, which acts as a junction between these three principle scientific theologies, is deoxyribonucleic acid (DNA) or ribonucleic acid (RNA). These biopolym… more
Date: August 5, 2003
Creator: Pris, Andrew David
Partner: UNT Libraries Government Documents Department
open access

Focus on NIF September 2001

Description: As of the end of August, the National Ignition Facility (NIF) is satisfactorily meeting its technical performance, cost and schedule milestones. Hensel Phelps Construction Company (HPCC) turned over the Laser Building to the Beampath Infrastructure System (BIS) Commissioning and Operations team for beneficial occupancy.
Date: September 5, 2001
Creator: Warner, B
Partner: UNT Libraries Government Documents Department
open access

Bio-Aerosol Detection Using Mass Spectrometry: Public Health Applications

Description: I recently spent a summer as an intern at the Lawrence Livermore National Laboratory. I worked on a project involving the real-time, reagentless, single cell detection of aerosolized pathogens using a novel mass spectrometry approach called Bio-Aerosol Mass Spectrometry (BAMS). Based upon preliminary results showing the differentiation capabilities of BAMS, I would like to explore the development and use of this novel detection system in the context of both environmental and clinical sample pat… more
Date: March 5, 2004
Creator: Ludvigson, L D
Partner: UNT Libraries Government Documents Department
open access

The Electric and Optical Properties of Doped Small Molecular Organic Light-Emitting Devices

Description: Organic light-emitting devices (OLEDs) constitute a new and exciting emissive display technology. In general, the basic OLED structure consists of a stack of fluorescent organic layers sandwiched between a transparent conducting-anode and metallic cathode. When an appropriate bias is applied to the device, holes are injected from the anode and electrons from the cathode; some of the recombination events between the holes and electrons result in electroluminescence (EL). Until now, most of the e… more
Date: August 5, 2003
Creator: Cheon, Kwang-Ohk
Partner: UNT Libraries Government Documents Department
open access

Electron-capture delayed fission properties of neutron-deficient einsteinium nuclei

Description: Electron-capture delayed fission (ECDF) properties of neutron-deficient einsteinium isotopes were investigated using a combination of chemical separations and on-line radiation detection methods. {sup 242}Es was produced via the {sup 233}U({sup 14}N,5n){sup 242}Es reaction at a beam energy of 87 MeV (on target) in the lab system, and was found to decay with a half-life of 11 {+-} 3 seconds. The ECDF of {sup 242}Es showed a highly asymmetric mass distribution with an average pre-neutron emission… more
Date: January 5, 2000
Creator: Shaughnessy, Dawn A.
Partner: UNT Libraries Government Documents Department
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