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open access

Developments and Applications of Electrophoresis and Small Molecule Laser Desorption Ionization Mass Spectrometry

Description: Ultra-sensitive native fluorescence detection of proteins with miniaturized one- and two-dimensional polyacrylamide gel electrophoresis was achieved with laser side-entry excitation, which provides both high excitation power and low background level. The detection limit for R-phycoerythrin protein spots in 1-D SDS-PAGE was as low as 15 fg, which corresponds to 40 thousand molecules only. The average detection limit of six standard native proteins was 5 pg per band and the dynamic range spanned … more
Date: December 1, 2007
Creator: Zhang, Hui
Partner: UNT Libraries Government Documents Department
open access

Determination of W boson helicity fractions in top quark decays in p anti-p collisions at CDF Run II and production of endcap modules for the ATLAS Silicon Tracker

Description: The thesis presented here includes two parts. The first part discusses the production of endcap modules for the ATLAS SemiConductor Tracker at the University of Geneva. The ATLAS experiment is one of the two multi-purpose experiments being built at the LHC at CERN. The University of Geneva invested extensive efforts to create an excellent and efficient module production site, in which 655 endcap outer modules were constructed. The complexity and extreme requirements for 10 years of LHC operatio… more
Date: January 1, 2007
Creator: Moed, Shulamit & U., /Geneva
Partner: UNT Libraries Government Documents Department
open access

Measurement of the Top Quark Mass using Dilepton Events and a Neutrino Weighting Algorithm with the D0 Experiment at the Tevatron (Run II)

Description: Elementary particle physics raises questions that are several thousand years old. What are the fundamental components of matter and how do they interact? These questions are linked to the question of what happened in the very first moments after the creation of the universe. Modern physics systematically tests nature to find answers to these and other fundamental questions. Precise theories are developed that describe various phenomena and at the same time are reduced to a few basic principals … more
Date: January 1, 2007
Creator: Meyer, Joerg
Partner: UNT Libraries Government Documents Department
open access

Diffractive J/Psi Production

Description: This work presents measurements of two diffractive production ratio for heavy flavour physics with the use of a reconstructed J/{psi} {yields} {mu}{sup +}{mu}{sup -} sample in p{bar p} collisions at {radical}s = 1.96 TeV using the D0 detector at Fermilab Tevatron. These events were selected using the Luminosity Monitor detectors, the calorimeter system and the muon system in a pseudo-rapidity region with range 2.7 {le} |{eta}| {le} 4.4. The measured ratio were estimated to be N{sub diff}{sup J/… more
Date: July 1, 2007
Creator: Assis Jesus, Ana Carolina & U., /Rio de Janeiro Federal
Partner: UNT Libraries Government Documents Department
open access

The Study of WGamma production at D0: Anomalous Coupling Limits and the Radiation Amplitude Zero

Description: W{gamma} production is analyzed in the electron and muon decay channels with approximately 1 fb{sup -1} of data from p{bar p} collisions that were produced at a center-of-mass energy of {radical}s = 1.96 TeV and that were collected by the D0 detector at the Fermilab Tevatron collider. The inclusive p{bar p} {yields} {ell}{nu}{gamma} cross section is measured in both channels and is found to be consistent with the Standard Model expectation of 2.08 {+-} 0.05{sub PDF} pb for events with a photon … more
Date: June 1, 2007
Creator: Pawloski, Gregory J. & U., /Rice
Partner: UNT Libraries Government Documents Department
open access

A measurement of the top quark's charge

Description: The top quark was discovered in 1995 at the Fermilab National Accelerator Laboratory (Fermilab). One way to confirm if the observed top quark is really the top quark posited in the Standard Model (SM) is to measure its electric charge. In the Standard Model the top quark is the isospin partner of the bottom quark and is expected to have a charge of +2/3. However, an alternative 'exotic' model has been proposed with a fourth generation exotic quark that has the same characteristics, such as mass… more
Date: November 1, 2007
Creator: Unalan, Zeynep Gunay
Partner: UNT Libraries Government Documents Department
open access

The Development and Optimization of Techniques for Monitoring Water Quality on-Board Spacecraft Using Colorimetric Solid-Phase Extraction (C-SPE)

Description: The main focus of this dissertation is the design, development, and ground and microgravity validation of methods for monitoring drinking water quality on-board NASA spacecraft using clorimetric-solid phase extraction (C-SPE). The Introduction will overview the need for in-flight water quality analysis and will detail some of the challenges associated with operations in the absence of gravity. The ability of C-SPE methods to meet these challenges will then be discussed, followed by a literature… more
Date: December 1, 2007
Creator: Hill, April
Partner: UNT Libraries Government Documents Department
open access

Search for electroweak single top-quark production with the CDF II experiment

Description: Understanding the world -- This aim drives humankind since the beginning of conscious thinking. Especially the nature of matter has been of major interest. Nowadays, we have a complex image of the constitution of matter. Atoms consist of electrons and nucleons. But even nucleons are not elementary. Their basic constituents are called quarks. Physicists developed a model describing the elementary components of matter as well as the forces between them: the standard model of elementary particle p… more
Date: November 1, 2007
Creator: Richter, Svenja
Partner: UNT Libraries Government Documents Department
open access

Evidence for WZ Production and a Measurement of the WZ Production Cross Section

Description: This dissertation describes a test of the Standard Model (SM) of particle physics by measuring the probability, or cross section, of simultaneously producing a W boson and a Z boson from proton-antiproton collisions. The SM predicts the cross section of WZ production to be 3.68 {+-} 0.25 pb. The SM and physics of WZ production are described in Chapter 2 of this dissertation. The 1.96 TeV center-of-mass energy proton-antiproton collisions are provided by the Fermi National Accelerator Laboratory… more
Date: May 1, 2007
Creator: Degenhardt, James D.
Partner: UNT Libraries Government Documents Department
open access

A Measurement of the Branching Ratio of the pi0 Dalitz Decay using K(L) ---> 3 pi0 Decays from KTeV

Description: The authors present a measurement of B({pi}{sup 0} {yields} e{sup +}e{sup -}{gamma})/B({pi}{sup 0} {yields} {gamma}{gamma}) using data taken in 1999 by the E832 KTeV experiment at Fermilab. The {pi}{sup 0}s were produced by K{sub L} decays in flight that are fully reconstructed. They find 63,693 K{sub L} {yields} 3{pi}{sup 0} {yields} {gamma}{gamma} {gamma}{gamma} e{sup +}e{sup -}{gamma} decays in KTeV data (an increase of a factor of {approx} 20 in event statistics over previous experiments), … more
Date: August 1, 2007
Creator: Abouzaid, Erin E.
Partner: UNT Libraries Government Documents Department
open access

Development and Integration of Hardware and Software for Active-Sensors in Structural Monitoring

Description: Structural Health Monitoring (SHM) promises to deliver great benefits to many industries. Primarily among them is a potential for large cost savings in maintenance of complex structures such as aircraft and civil infrastructure. However, several large obstacles remain before widespread use on structures can be accomplished. The development of three components would address many of these obstacles: a robust sensor validation procedure, a low-cost active-sensing hardware and an integrated softwar… more
Date: October 15, 2007
Creator: Overly, Timothy G.S.
Partner: UNT Libraries Government Documents Department
open access

M5Si3(M=Ti, Nb, Mo) Based Transition-Metal Silicides for High Temperature Applications

Description: Transition metal silicides are being considered for future engine turbine components at temperatures up to 1600 C. Although significant improvement in high temperature strength, room temperature fracture toughness has been realized in the past decade, further improvement in oxidation resistance is needed. Oxidation mechanism of Ti{sub 5}Si{sub 3}-based alloys was investigated. Oxidation behavior of Ti{sub 5}Si{sub 3}-based alloy strongly depends on the atmosphere. Presence of Nitrogen alters th… more
Date: December 1, 2007
Creator: Tang, Zhihong
Partner: UNT Libraries Government Documents Department
open access

A search for sterile neutrinos in MINOS

Description: MINOS, the Main Injector Neutrino Oscillation Search, is a long baseline neutrino oscillation experiment based at Fermilab National Accelerator Laboratory. The experiment uses a neutrino beam, which is measured 1 km downstream from its origin in the Near detector at Fermilab and then 735 km later in the Far detector at the Soudan mine. By comparing these two measurements, MINOS can attain a very high precision for parameters in the atmospheric sector of neutrino oscillations. In addition to pre… more
Date: December 1, 2007
Creator: Osiecki, Thomas Henry
Partner: UNT Libraries Government Documents Department
open access

Measurements of Branching Fraction and CP Violation inB Meson Rare Decays to Final States containing eta or eta' Mesons in the BaBar Experiment at SLAC

Description: Note that the main goal of this thesis work is the measurement of the branching fractions, charge asymmetry, and Time-Dependent CP Violation in {eta}'K{sup 0} mode. All other measurements are reported here for completion because they are connected by similar physics arguments. They are part of the Milan analysis activity, done by undergraduate students. They should not be considered as done in this thesis work. The measurements of the two body-modes {eta}{eta}, {eta}{phi}, and {eta}'{phi} are u… more
Date: July 17, 2007
Creator: Lazzaro, Alfio & U., /Milan
Partner: UNT Libraries Government Documents Department
open access

Processing and Protection of Rare Earth Permanent Magnet Particulate for Bonded Magnet Applications

Description: Rapid solidification of novel mixed rare earth-iron-boron, MRE{sub 2}Fe{sub 14}B (MRE = Nd, Y, Dy; currently), magnet alloys via high pressure gas atomization (HPGA) have produced similar properties and structures as closely related alloys produced by melt spinning (MS) at low wheel speeds. Recent additions of titanium carbide and zirconium to the permanent magnet (PM) alloy design in HPGA powder (using He atomization gas) have made it possible to achieve highly refined microstructures with mag… more
Date: December 1, 2007
Creator: Sokolowski, Peter Kelly
Partner: UNT Libraries Government Documents Department
open access

Nanostructured Solid Oxide Fuel Cell Electrodes

Description: The ability of Solid Oxide Fuel Cells (SOFC) to directly and efficiently convert the chemical energy in hydrocarbon fuels to electricity places the technology in a unique and exciting position to play a significant role in the clean energy revolution. In order to make SOFC technology cost competitive with existing technologies, the operating temperatures have been decreased to the range where costly ceramic components may be substituted with inexpensive metal components within the cell and stac… more
Date: December 15, 2007
Creator: Sholklapper, Tal Zvi
Partner: UNT Libraries Government Documents Department
open access

High-Throughput Analysis of Enzyme Activities

Description: High-throughput screening (HTS) techniques have been applied to many research fields nowadays. Robot microarray printing technique and automation microtiter handling technique allows HTS performing in both heterogeneous and homogeneous formats, with minimal sample required for each assay element. In this dissertation, new HTS techniques for enzyme activity analysis were developed. First, patterns of immobilized enzyme on nylon screen were detected by multiplexed capillary system. The imaging re… more
Date: December 1, 2007
Creator: Lu, Guoxin
Partner: UNT Libraries Government Documents Department
open access

First Observation of An Excited Charm Baryon Decaying to Omega Charm Baryon at the BaBar Experiment

Description: We have carried out a search for a charmed baryon {Omega}{sup *}{sub c} decaying to {Omega}{sup 0}{sub c} and a {gamma} where {Omega}{sub c} candidates are reconstructed using decay modes {Omega}{sup -}{pi}{sup +}(c1), {Omega}{sup -}{pi}{sup +}{pi}{sup 0}(c2), {Omega}{sup -}{pi}{sup +}{pi}{sup -}{pi}{sup +}(c3) and {Xi}{sup -}K{sup -}{pi}{sup +}{pi}{sup +}(c4). This search is performed by analyzing integrated luminosity of 230.7 fb{sup -1} data collected by the BABAR detector at the Stanford Li… more
Date: November 26, 2007
Creator: Bula, Rahmi & /SUNY, Albany
Partner: UNT Libraries Government Documents Department
open access

Dalitz Analysis of D0 to K0(S) Pi+ Pi- and Measurement of the CKM Angle Gamma in Charged B+- Decays to D(*) K+- Decays

Description: Despite more than thirty years having elapsed since the discovery of CP violation, our understanding about the source and the nature of this phenomenon is still very limited. In the standard model of particle physics, CP violation is due to the presence of an non-irreducible weak phase in the Cabibbo-Kabayashi-Maskawa(CKM) matrix. Up to now, all the experimental results are in good agreement with the standard model. However, it is important for us to over-constrain the CKM quark-mixing matrix a… more
Date: July 10, 2007
Creator: Lau, Yan-Pan
Partner: UNT Libraries Government Documents Department
open access

A measurement of the top quark mass in 1.96 TeV proton-antiproton collisions using a novel matrix element method

Description: A measurement of the top quark mass in t{bar t} {yields} l + jets candidate events, obtained from p{bar p} collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector, is presented. The measurement approach is that of a matrix element method. For each candidate event, a two dimensional likelihood is calculated in the top pole mass and a constant scale factor, 'JES', where JES multiplies the input particle jet momenta and is designed to account for the systematic uncer… more
Date: December 1, 2007
Creator: Freeman, John C.
Partner: UNT Libraries Government Documents Department
open access

Performance-Driven Interface Contract Enforcement for Scientific Components

Description: Performance-driven interface contract enforcement research aims to improve the quality of programs built from plug-and-play scientific components. Interface contracts make the obligations on the caller and all implementations of the specified methods explicit. Runtime contract enforcement is a well-known technique for enhancing testing and debugging. However, checking all of the associated constraints during deployment is generally considered too costly from a performance stand point. Previous … more
Date: October 1, 2007
Creator: Dahlgren, T L
Partner: UNT Libraries Government Documents Department
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