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Study of the Ds+ to K+K-e+ nu Decay Channel with the BaBar Experiment

Description: Charm semileptonic decays allow a validation of lattice QCD calculations through the measurement of the hadronic form factors, which characterize the effect of strong interaction in these reactions. The accuracy of such calculations is crucial for the improvement of the test of the standard model in flavor physics. This thesis presents a study of the D{sub s}{sup +} {yields} K{sup +}K{sup -}e{sup +}{nu}{sub e} channel using 214 fb{sup -1} recorded by de BAbar experiment. For events with a K{sup… more
Date: September 9, 2008
Creator: Serrano, Justine & /Orsay, IPN /SLAC
Partner: UNT Libraries Government Documents Department
open access

Physical Studies of Cell Division: Statistical Fluctuations; Effects Due to X-Radiation, Temperature, and Hydrostatic Pressure

Description: Thesis discussing "a technique for determining the generation times of individual yeast cells...the effect of x-radiation on the generation times of individual cells and their progeny..." and "attempts to synchronize cell division in a population of cells."
Date: December 9, 1954
Creator: Burns, Victor Will
Partner: UNT Libraries Government Documents Department
open access

Investigation of the phase equilibria and phase transformations associated with the Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub y} superconductor

Description: The solid solution region and reaction kinetics of the Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub y} (2212) superconductor were examined as a function of temperature and oxygen partial pressure. Crystallization studies from the glassy and molten states were undertaken to determine the phase transformation and kinetics associated with the formation of 2212 and other competing phases. Crystallization of nominal 2212 glasses was found to proceed in two steps with the formation of Bi{sub 2}Sr{sub 2{minus}x… more
Date: December 9, 1993
Creator: Holesinger, T.
Partner: UNT Libraries Government Documents Department
open access

Plasma enhanced chemical vapor deposition of ZrO{sub 2} thin films

Description: Amorphous ZrO{sub 2} thin films were deposited in an inductively coupled PECVD system using a Zr {beta}-diketonate, Zr(C{sub 11}H{sub 19}O{sub 2}){sub 4}, as the precursor. The deposits were air annealed at 900C for 5 min to get pure, single phase, oriented, polycrystalline {alpha}-ZrO{sub 2}. Feasibility of using 2 different types of reactors was investigated. The inductively heated horizontal reactor depositions at 600C had a lower deposition rate and the films were non-uniform in thickness w… more
Date: December 9, 1993
Creator: Saravanan, Kolandaivelu
Partner: UNT Libraries Government Documents Department
open access

Homometallic and Heterometallic Antiferromagnetic Rings: Magnetic Properties Studied by Nuclear Magnetic Resonance

Description: The aim of the present thesis is to investigate the local magnetic properties of homometallic Cr{sub 8} antiferromagnetic (AFM) ring and the changes occurring by replacing one Cr{sup 3+} ion with diamagnetic Cd{sup 2+} (Cr{sub 7}Cd) and with Ni{sup 2+} (Cr{sub 7}Ni). In the heterometallic ring a redistribution of the local magnetic moment is expected in the low temperature ground state. We have investigated those changes by both {sup 53}Cr-NMR and {sup 19}F-NMR. We have determined the order of … more
Date: May 9, 2012
Creator: Casadei, Cecilia
Partner: UNT Libraries Government Documents Department
open access

Quantum groups, non-commutative differential geometry and applications

Description: The topic of this thesis is the development of a versatile and geometrically motivated differential calculus on non-commutative or quantum spaces, providing powerful but easy-to-use mathematical tools for applications in physics and related sciences. A generalization of unitary time evolution is proposed and studied for a simple 2-level system, leading to non-conservation of microscopic entropy, a phenomenon new to quantum mechanics. A Cartan calculus that combines functions, forms, Lie derivat… more
Date: December 9, 1993
Creator: Schupp, P.
Partner: UNT Libraries Government Documents Department
open access

Indium Growth and Island Height Control on Si Submonolayer Phases

Description: Nanotechnology refers any technique that involves about object with nanoscale (10{sup -9} m) or even smaller. It has become more and more important in recently years and has changed our world dramatically. Most of modern electronic devices today should thanks to the miniaturizing driven by development of nanotechnology. Recent years, more and more governments are investing huge amount of money in research related to nanotechnology. There are two major reasons that nanostructure is so fascinate.… more
Date: May 9, 2009
Creator: Chen, Jizhou
Partner: UNT Libraries Government Documents Department
open access

High Resolution Studies of the Origins of Polyatomic Ions in Inductively Coupled Plasma-Mass Spectrometry

Description: The inductively coupled plasma (ICP) is an atmospheric pressure ionization source. Traditionally, the plasma is sampled via a sampler cone. A supersonic jet develops behind the sampler, and this region is pumped down to a pressure of approximately one Torr. A skimmer cone is located inside this zone of silence to transmit ions into the mass spectrometer. The position of the sampler and skimmer cones relative to the initial radiation and normal analytical zones of the plasma is key to optimizing… more
Date: August 9, 2006
Creator: Ferguson, Jill Wisnewski
Partner: UNT Libraries Government Documents Department
open access

Designing of Metallic Photonic Structures and Applications

Description: In this thesis our main interest has been to investigate metallic photonic crystal and its applications. We explained how to solve a periodic photonic structure with transfer matrix method and when and how to use modal expansion method. Two different coating methods were introduced, modifying a photonic structure's intrinsic optical properties and rigorous calculation results are presented. Two applications of metallic photonic structures are introduced. For thermal emitter, we showed how to de… more
Date: August 9, 2006
Creator: Kim, Yong-Sung
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

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

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

The Node Monitoring Component of a Scalable Systems Software Environment

Description: This research describes Fountain, a suite of programs used to monitor the resources of a cluster. A cluster is a collection of individual computers that are connected via a high speed communication network. They are traditionally used by users who desire more resources, such as processing power and memory, than any single computer can provide. A common drawback to effectively utilizing such a large-scale system is the management infrastructure, which often does not often scale well as the syste… more
Date: August 9, 2006
Creator: Miller, Samuel James
Partner: UNT Libraries Government Documents Department
open access

Structural and Magnetothermal Properties of Compounds: Yb5SixGe4-x,Sm5SixGe4-x, EuO, and Eu3O4

Description: The family of R{sub 5}Si{sub x}Ge{sub 4-x} alloys demonstrates a variety of unique physical phenomena related to magneto-structural transitions associated with reversible breaking and reforming of specific bonds that can be controlled by numerous external parameters such as chemical composition, magnetic field, temperature, and pressure. Therefore, R{sub 5}Si{sub x}Ge{sub 4-x} systems have been extensively studied to uncover the mechanism of the extraordinary magneto-responsive properties inclu… more
Date: May 9, 2007
Creator: Ahn, Kyunghan
Partner: UNT Libraries Government Documents Department
open access

Nuclear reactions with 11C and 14O radioactive ion beams

Description: Radioactive ion beams (RIBs) have been shown to be a useful tool for studying proton-rich nuclides near and beyond the proton dripline and for evaluating nuclear models. To take full advantage of RIBs, Elastic Resonance Scattering in Inverse Kinematics with Thick Targets (ERSIKTT), has proven to be a reliable experimental tool for investigations of proton unbound nuclei. Following several years of effort, Berkeley Experiments with Accelerated Radioactive Species (BEARS), a RIBs capability, has … more
Date: December 9, 2004
Creator: Guo, Fanqing
Partner: UNT Libraries Government Documents Department
open access

Plasma channel and Z-pinch dynamics for heavy ion transport

Description: A self stabilized, free standing, z-pinch plasma channel has been proposed to deliver the high intensity heavy ion beam from the end of a driver to the fuel target in a heavy ion inertial fusion power plant. The z-pinch relaxes emittance and energy spread requirements requiring a lower cost driver. A z-pinch transport would reduce the number of beam entry port holes to the target chamber from over a hundred to four as compared to neutralized ballistic focusing thus reducing the driver hardware … more
Date: July 9, 2002
Creator: Ponce-Marquez, David
Partner: UNT Libraries Government Documents Department
open access

[Chemistry Thesis] Part 2: High Intensity Light Sources

Description: A stable carbon arc operated in controlled atmosphere is described. The arc was designed to serve as a light source during lifetime studies of the B/sup 2/ SIGMA state of the CN molecule. The CN radiation from the plasma of the arc was investigated and found to have a brightness temperature of 5500 icient laborato K at lambda 3883 A. This is considerably higher than an estimate of the value required for lifetime measurements. The stability of the carbon arc under various conditions is discussed… more
Date: October 9, 1958
Creator: Worden, Earl Fremont, Jr.
Partner: UNT Libraries Government Documents Department
open access

Characterization of Zns-GaP Naon-composites

Description: It proved possible to produce consistent, high-quality nanocrystalline ZnS powders with grain sizes as small as 8 nm. These powders are nano-porous and are readily impregnated with GaP precursor, although inconsistently. Both crystal structure and small grain size of the ZnS can be maintained through the use of GaP. Heat treatment of the impregnated powders results in a ZnS-GaP composite structure where the grain sizes of the phases are on the order of 10--20 nm. Conventional powder processing … more
Date: December 9, 1993
Creator: Todd, V.
Partner: UNT Libraries Government Documents Department
open access

The effect of spacer ribs on Ledinegg type flow instabilities

Description: An experimental program has been completed which evaluated the effect of a flow obstruction in a heated channel on the onset of flow instability (OBI). The test channel was rectangular (80 {times} 3 mm), heated on one surface, and equipped with view ports. Tests were conducted in a flow controlled mode at heat fluxes of 370 kW/M{sup 2}, and 610 kW/m{sup 2}. Direct comparisons were made between the demand curve minimum for the unobstructed channel and a channel equipped with a 2.07 mm wide rib t… more
Date: September 9, 1993
Creator: Coutts, D. A.
Partner: UNT Libraries Government Documents Department
open access

Multipole Analysis of Circular Cylindircal Magnetic Systems

Description: This thesis deals with an alternate method for computing the external magnetic field from a circular cylindrical magnetic source. The primary objective is to characterize the magnetic source in terms of its equivalent multipole distribution. This multipole distribution must be valid at points close to the cylindrical source and a spherical multipole expansion is ill-equipped to handle this problem; therefore a new method must be introduced. This method, based upon the free-space Green's functio… more
Date: January 9, 2006
Creator: Selvaggi, J
Partner: UNT Libraries Government Documents Department
open access

Structurally Integrated Photoluminescence-Based Lactate Sensor Using Organic Light Emitting Devices (OLEDs) as the Light Source

Description: Multianalyte bio(chemical) sensors are extensively researched for monitoring analytes in complex systems, such as blood serum. As a step towards developing such multianalyte sensors, we studied a novel, structurally integrated, organic light emitting device (OLED)-based sensing platform for detection of lactate. Lactate biosensors have attracted numerous research efforts, due to their wide applications in clinical diagnosis, athletic training and food industry. The OLED-based sensor is based on… more
Date: August 9, 2006
Creator: Qian, Chengliang
Partner: UNT Libraries Government Documents Department
open access

Soft-Lithographical Fabrication of Three-dimensional Photonic Crystals in the Optical Regime

Description: This dissertation describes several projects to realize low-cost and high-quality three-dimensional (3D) microfabrication using non-photolithographic techniques for layer-by-layer photonic crystals. Low-cost, efficient 3D microfabrication is a demanding technique not only for 3D photonic crystals but also for all other scientific areas, since it may create new functionalities beyond the limit of planar structures. However, a novel 3D microfabrication technique for photonic crystals implies the … more
Date: August 9, 2006
Creator: Lee, Jae-Hwang
Partner: UNT Libraries Government Documents Department
open access

Quantum Monte Carlo Calculations Applied to Magnetic Molecules

Description: We have calculated the equilibrium thermodynamic properties of Heisenberg spin systems using a quantum Monte Carlo (QMC) method. We have used some of these systems as models to describe recently synthesized magnetic molecules, and-upon comparing the results of these calculations with experimental data-have obtained accurate estimates for the basic parameters of these models. We have also performed calculations for other systems that are of more general interest, being relevant both for existing… more
Date: August 9, 2006
Creator: Engelhardt, Larry
Partner: UNT Libraries Government Documents Department
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