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Efficient Execution of Electronic Structure Calculations on SMP Clusters

Description: Applications augmented with adaptive capabilities are becoming common in parallel computing environments. For large-scale scientific applications, dynamic adjustments to a computationally-intensive part may lead to a large pay-off in facilitating efficient execution of the entire application while aiming at avoiding resource contention. Application-specific knowledge, often best revealed during the run-time, is required to initiate and time these adjustments. In particular, General Atomic and M… more
Date: May 1, 2006
Creator: Ustemirov, Nurzhan
Partner: UNT Libraries Government Documents Department
open access

Search for r-parity violating supersymmetry in the multilepton final state

Description: This thesis presents a search for physics beyond the standard model of elementary particles in events containing three or more charged leptons in the final state. The search is based on an R-parity violating supersymmetric model that assumes supersymmetric particles are pair produced at hadron colliders and the R-parity violating coupling is small enough so that these particles ''cascade'' decay into the lightest supersymmetric particle. The lightest supersymmetric particle may only decay into … more
Date: November 1, 2006
Creator: Attal, Alon J.
Partner: UNT Libraries Government Documents Department
open access

Rare-Earth Transition-Metal Intermetallics: Structure-bonding-Property Relationships

Description: Our explorations of rare-earth, transition metal intermetallics have resulted in the synthesis and characterization, and electronic structure investigation, as well as understanding the structure-bonding-property relationships. Our work has presented the following results: (1) Understanding the relationship between compositions and properties in LaFe{sub 13-x}Si{sub x} system: A detailed structural and theoretical investigation provided the understanding of the role of a third element on stabil… more
Date: May 1, 2006
Creator: Han, Mi-Kyung
Partner: UNT Libraries Government Documents Department
open access

Measurement of the inclusive jet cross section using the midpoint algorithm in Run II at CDF

Description: A measurement is presented of the inclusive jet cross section using the Midpoint jet clustering algorithm in five different rapidity regions. This is the first analysis which measures the inclusive jet cross section using the Midpoint algorithm in the forward region of the detector. The measurement is based on more than 1 fb{sup -1} of integrated luminosity of Run II data taken by the CDF experiment at the Fermi National Accelerator Laboratory. The results are consistent with the predictions of… more
Date: December 1, 2006
Creator: Group, Robert Craig
Partner: UNT Libraries Government Documents Department
open access

A search for charge 1/3 third generation leptoquarks in muon channels

Description: Leptoquarks are exotic particles that have color, electric charge, and lepton number and appear in extended gauge theories and composite models. Current theory suggests that leptoquarks would come in three different generations corresponding to the three quark and lepton generations. We are searching for charge 1/3 third generation leptoquarks produced in p{bar p} collisions at {radical}s = 1.96 TeV using data collected by the D0 detector. Such leptoquarks would decay into either a tau-neutrino… more
Date: August 1, 2006
Creator: Uzunyan, Sergey A.
Partner: UNT Libraries Government Documents Department
open access

Computational Fluid Dynamics Simulation of Fluidized Bed Polymerization Reactors

Description: Fluidized beds (FB) reactors are widely used in the polymerization industry due to their superior heat- and mass-transfer characteristics. Nevertheless, problems associated with local overheating of polymer particles and excessive agglomeration leading to FB reactors defluidization still persist and limit the range of operating temperatures that can be safely achieved in plant-scale reactors. Many people have been worked on the modeling of FB polymerization reactors, and quite a few models are … more
Date: August 9, 2006
Creator: Fan, Rong
Partner: UNT Libraries Government Documents Department
open access

Biomimetic Nanocomposites of Calcium Phosphate and Self-Assembling Triblock and Pentablock Copolymers

Description: In an effort to mimic the growth of natural bone, self-assembling, micelle and gel-forming copolymers were used as a template for calcium phosphate precipitation. Because of the cationic characteristics imparted by PDEAEM end group additions to commercially available Pluronic{reg_sign} Fl27, a direct ionic attraction mechanism was utilized and a polymer-brushite nanocomposite spheres were produced. Brushite coated spherical micelles with diameters of {approx}40 nm, and agglomerates of these par… more
Date: August 9, 2006
Creator: Enlow, Drew Lenzen
Partner: UNT Libraries Government Documents Department
open access

A combined muon-neutrino and electron-neutrino oscillation search at MiniBooNE

Description: MiniBooNE seeks to corroborate or refute the unconfirmed oscillation result from the LSND experiment. If correct, the result implies that a new kind of massive neutrino, with no weak interactions, participates in neutrino oscillations. MiniBooNE searches for {nu}{sub {mu}} {yields} {nu}{sub e} oscillations with the Fermi National Accelerator Laboratory 8 GeV beam line, which produces a {nu}{sub {mu}} beam with an average energy of {approx} 0.8 GeV and an intrinsic {nu}{sub e} content of 0.4%. T… more
Date: July 1, 2006
Creator: Monroe, Jocelyn R.
Partner: UNT Libraries Government Documents Department
open access

Developing New Nanoprobes from Semiconductor Nanocrystals

Description: In recent years, semiconductor nanocrystal quantum dots havegarnered the spotlight as an important new class of biological labelingtool. Withoptical properties superior to conventional organicfluorophores from many aspects, such as high photostability andmultiplexing capability, quantum dots have been applied in a variety ofadvanced imaging applications. This dissertation research goes along withlarge amount of research efforts in this field, while focusing on thedesign and development of new n… more
Date: May 29, 2006
Creator: Fu, Aihua
Partner: UNT Libraries Government Documents Department
open access

Electron Transfer Reactivity Patterns at Chemically Modified Electrodes: Fundamentals and Application to the Optimization of Redox Recycling Amplification Systems

Description: Electroanalytical chemistry is often utilized in chemical analysis and Fundamental studies. Important advances have been made in these areas since the advent of chemically modified electrodes: the coating of an electrode with a chemical film in order to impart desirable, and ideally, predictable properties. These procedures enable the exploitation of unique reactivity patterns. This dissertation presents studies that investigate novel reaction mechanisms at self-assembled monolayers on gold. In… more
Date: May 1, 2006
Creator: Bergren, Adam Johan
Partner: UNT Libraries Government Documents Department
open access

Surface-Enhanced Raman Scattering (SERS) for Detection in Immunoassays: applications, fundamentals, and optimization

Description: Immunoassays have been utilized for the detection of biological analytes for several decades. Many formats and detection strategies have been explored, each having unique advantages and disadvantages. More recently, surface-enhanced Raman scattering (SERS) has been introduced as a readout method for immunoassays, and has shown great potential to meet many key analytical figures of merit. This technology is in its infancy and this dissertation explores the diversity of this method as well as the… more
Date: August 9, 2006
Creator: Driskell, Jeremy Daniel
Partner: UNT Libraries Government Documents Department
open access

CPT conservation and atmospheric neutrinos in the MINOS far detector

Description: The MINOS Far Detector is a 5400 ton iron calorimeter located at the Soudan state park in Soudan Minnesota. The MINOS far detector can observe atmospheric neutrinos and separate charge current {nu}{sub {mu}} and {bar {nu}}{sub {mu}} interactions by using a 1.4 T magnetic field to identify the charge of the produced muon. The CPT theorem requires that neutrinos and anti-neutrinos oscillate in the same way. In a fiducial exposure of 5.0 kilo-ton years a total of 41 candidate neutrino events are o… more
Date: February 1, 2006
Creator: Becker, Bernard Raymond
Partner: UNT Libraries Government Documents Department
open access

Improvement of Photon Buildup Factors for Radiological Assessment

Description: Slant-path buildup factors for photons between 1 keV and 10 MeV for nine radiation shielding materials (air, aluminum, concrete, iron, lead, leaded glass, polyethylene, stainless steel, and water) are calculated with the most recent cross-section data available using Monte Carlo and discrete ordinates methods. Discrete ordinates calculations use a 244-group energy structure that is based on previous research at Los Alamos National Laboratory (LANL), but extended with the results of this thesis,… more
Date: July 1, 2006
Creator: Schirmers, F.G.
Partner: UNT Libraries Government Documents Department
open access

Transient Eddy Current Response Due to a Subsurface Crack in a Conductive Plate

Description: Eddy current nondestructive evaluation (NDE) is usually carried out by exciting a time harmonic field using an inductive probe. However, a viable alternative is to use transient eddy current NDE in which a current pulse in a driver coil produces a transient .eld in a conductor that decays at a rate dependent on the conductivity and the permeability of the material and the coil configuration. By using transient eddy current, it is possible to estimate the properties of the conductive medium and … more
Date: August 9, 2006
Creator: Fu, Fangwei
Partner: UNT Libraries Government Documents Department
open access

New Synthetic Methods for Hypericum Natural Products

Description: Organic chemistry has served as a solid foundation for interdisciplinary research areas, such as molecular biology and medicinal chemistry. An understanding of the biological activities and structural elucidations of natural products can lead to the development of clinically valuable therapeutic options. The advancements of modern synthetic methodologies allow for more elaborate and concise natural product syntheses. The theme of this study centers on the synthesis of natural products with part… more
Date: December 12, 2006
Creator: Jeon, Insik
Partner: UNT Libraries Government Documents Department
open access

Search for anomalous production of events with a high energy lepton and photon at the Tevatron

Description: We present results of a search for the anomalous production of events containing a high-transverse momentum charged lepton ({ell}, either e or {mu}) and photon ({gamma}), accompanied by missing transverse energy (E{sub T}), and/or additional leptons and photons, and jets (X). We use the same kinematic selection criteria as in a previous CDF search, but with a substantially larger data set, 305 pb{sup -1}, a p{bar p} collision energy of 1.96 TeV, and the upgraded CDF II detector. We find 42 {ell… more
Date: January 1, 2006
Creator: Loginov, Andrey Borisovich & /Moscow, ITEP
Partner: UNT Libraries Government Documents Department
open access

High-Contrast Imaging using Adaptive Optics for Extrasolar Planet Detection

Description: Direct imaging of extrasolar planets is an important, but challenging, next step in planetary science. Most planets identified to date have been detected indirectly--not by emitted or reflected light but through the effect of the planet on the parent star. For example, radial velocity techniques measure the doppler shift in the spectrum of the star produced by the presence of a planet. Indirect techniques only probe about 15% of the orbital parameter space of our solar system. Direct methods wo… more
Date: August 18, 2006
Creator: Evans, J. W.
Partner: UNT Libraries Government Documents Department
open access

A search for third generation scalar leptoquarks

Description: Leptoquarks (LQ) are particles with both color and lepton number predicted in some gauge theories and composite models. Current theory suggests that leptoquarks would come in three different generations. We report on a search for charge 1/3 third generation leptoquarks produced in p{bar p} collisions at {radical}s = 1.96 TeV using data collected by the D0 detector at Fermilab. Such leptoquarks would decay into a tau-neutrino plus a b-quark with branching fraction B. We present preliminary resul… more
Date: August 1, 2006
Creator: Zatserklyaniy, Andriy
Partner: UNT Libraries Government Documents Department
open access

Phase Transformation in Cast Superaustenitic Stainless Steels

Description: Superaustenitic stainless steels constitute a group of Fe-based alloys that are compositionally balanced to have a purely austenitic matrix and exhibit favorable pitting and crevice corrosion resistant properties and mechanical strength. However, intermetallic precipitates such as sigma and Laves can form during casting or exposure to high-temperature processing, which degrade the corrosion and mechanical properties of the material. The goal of this study was to accurately characterize the soli… more
Date: December 12, 2006
Creator: Phillips, Nathaniel Steven Lee
Partner: UNT Libraries Government Documents Department
open access

Search for techniparticles at D0 Run II

Description: Technicolor theory (TC) accomplishes the necessary electroweak symmetry breaking responsible for the mass of the elementary particles. TC postulates the existence of a new SU(N{sub TC}) gauge theory. Like QCD the exchange of gauge bosons causes the existence of a non-vanishing chiral condensate which dynamically breaks the SU(N{sub TC}){sub L} x SU(N{sub TC}){sub R} symmetry. This gives rise to N{sub TC}{sup 2}-1 Nambu-Goldstone Bosons. Three of these Goldstone Bosons become the longitudinal co… more
Date: January 1, 2006
Creator: Feligioni, Lorenzo & U., /Boston
Partner: UNT Libraries Government Documents Department
open access

A search for the Higgs boson in the zh channel with the D0 detector at the Fermilab Tevatron collider

Description: This analysis describes a search for a standard model Higgs boson produced in association with a Z boson through the decay mode ZH {yields} e{sup +}e{sup -}b{bar b} in p{bar p} collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron Collider. The data sample used in this analysis corresponds to 452 pb{sup -1} of integrated luminosity accumulated with the D{null} detector. Agreement between data and standard model predictions is observed. A 95% confidence level upper exclusion limit for the… more
Date: November 1, 2006
Creator: Heinmiller, James Matthew
Partner: UNT Libraries Government Documents Department
open access

B-tagging and the search for neutral supersymmetric Higgs bosons at D0

Description: A search for neutral supersymmetric Higgs bosons and work relating to the improvement of the b-tagging and trigger capabilities at the D0 detector during Run II of the Fermilab Tevatron collider is presented. The search for evidence of the Higgs sector in the Standard Model (SM) and supersymmetric extensions of the SM are a high priority for the D0 collaboration, and b-tagging and good triggers are a vital component of these searches. The development and commissioning of the first triggers at D… more
Date: October 1, 2006
Creator: Scanlon, Tim
Partner: UNT Libraries Government Documents Department
open access

Search for the single top quarks produced in s-channel via electroweak interactions at s = 1-96 at the Tevatron

Description: The authors present a search for single top quarks produced in the s-channel electroweak production mode. The search is performed in the electron+jets decay channels, with one or more secondary-vertex tagged jets to indicate the presence of a b-jet and hence improving the signal:background ratio. Separation between signal and background is further enhanced by the use of Feed Forward Neural networks. 360 pb{sup -1} of Run II data used for this analysis was delivered by the Tevatron, and collecte… more
Date: January 1, 2006
Creator: Jabeen, Shabnam
Partner: UNT Libraries Government Documents Department
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