Physical Sciences and Mathematics Commons^™

Open Heavy Flavor Measurement At Forward Angles For Cu+Cu Collisions At Center Of Mass Nn Collision Energy 200 Gev, Irakli Garishvili

Doctoral Dissertations

The main purpose of Relativistic Heavy Ion Collider (RHIC) program is to study the Quark-Gluon Plasma (QGP), a deconfined state of matter believed to be created in ultra-relativistic heavy ion collisions. Heavy quarks, expected to be produced during the earlier stages of heavy ion collisions, serve as an important probe of the QGP.‎

‎The following dissertation presents measurements of single muons resulting from the semileptonic decay of heavy flavor quarks in the rapidity range of $1.4 < \vert\eta\vert < 1.9$ for Cu+Cu nuclei collisions at $\sqrt{s_{NN}}=200$ GeV measured by the PHENIX experiment. Single muon spectra were measured for three different centrality classes (0 - 20 \% , 20 - 40 \%, 40 - 94 \%) within the $p_{T}$ range of 1.0 - 4.0 GeV/c.‎

‎To calculate single muon spectra, a full background estimate was statistically subtracted from inclusive spectra of muon candidate tracks reconstructed in the PHENIX muon …

Beta-Decay, Beta-Delayed Neutron Emission And Isomer Studies Around 78Ni, Mustafa Moiz Rajabali

Doctoral Dissertations

A study of nuclei with few nucleons outside the closed shell provides benchmarks for the nuclear shell model especially in this modern era of physics where exotic doubly magic nuclei can be tested. The subject of this thesis is to experimentally investigate the properties of nuclei near ⁷⁸Ni and to confront them with the predictions of modern large scale shell model calculations. In this regard, an experiment was performed at the National Superconducting Cyclotron Laboratory (NSCL) to measure excited states in ^71-73Ni populated via the beta-decay of ^71-73Co. Data collected from this experiment lead to partial level …

Controlled Self-Organization And Tunable Collective Phenomena In Surface-Based Nanostructures, Eun Ju Moon

Doctoral Dissertations

Nanostructure systems possessing certain desirable features can arise from the self-organization of fundamental building blocks. In this thesis we explore two types of controlled self-assembly mechanisms in hetero-epitaxy: (a) classical assembly of atom vacancies into quasi one-dimensional line structures and (b) quantum-driven assembly of atoms into atomically-smooth two-dimensional thin films. In the classical assembly phenomenon, adatom vacancies, created via elastic strain-relaxation in compressively strained atom chains on a silicon substrate, self-organize into meandering vacancy lines. The average spacing between these line defects can be varied by adjusting the chemical potential μ of the adsorbed atoms. We implemented a lattice model …

Development And Implementation Of A New Technique To Study (P,Α) Reactions Relevant To Nucleosynthesis In Binary Systems, Brian Hossain Moazen

Doctoral Dissertations

The accurate determination of the strengths and energies of resonances in (p,alpha) reactions is important for understanding the influence of reaction cycles to element synthesis in many astrophysical environments. Thus far, (p,alpha) studies in inverse kinematics have employed solid polypropylene targets. These are not always advantageous, especially when the energy loss of the incoming beam in the solid target is significantly larger than the resonance width. At the Holifield Radioactive Ion Beam Facility, a new technique has been developed for measuring the strengths and energies of (p,alpha) reactions. In this technique, a large differentially-pumped scattering chamber is filled with hydrogen …

Wide-Range Characterization Of Current Conduction In Superconductors-Tuning Their Properties By Nanoscale Modification Of Materials, Özgür Polat

Doctoral Dissertations

Significant progress has been made in the development of YBa₂Cu₃O_7-x (YBCO)-based coated conductors (CCs) since the discovery of YBCO in 1987. Nowadays, high temperature superconductor (HTS) materials are advancing toward wide application areas in medical physics, industry, and science. The successful applications of these materials require clear understanding of the mechanisms controlling the current carrying capacity. It has been demonstrated the maximum current that a HTS can support is strongly affected by the vortex dynamics within the HTS materials. In this dissertation, we employed a combination of methods: conventional transport, magnetometry in a swept magnetic …

Polarimetry Studies For The Npdgamma Experiment At The Sns, Mostafa Jon Dadras

Masters Theses

The NPDGamma collaboration aims to measure a parity{violating directional gamma-ray asymmetry from the capture of polarized cold neutrons on protons. The asymmetry, predicted to be on the order of 50 ppb, is a result of the weak interaction between mesons and nucleons during the neutron capture reaction. The experiment is designed to make a statistics limited measurement of the asymmetry at the level of about 20%. The experiment will be carried out at the Fundamental neutron Physics Beamline (FnPB) at the Spallation Neutron Source (SNS). The neutron beam is polarized by a super{mirror polarizer. A 9.5 G magnetic field guides …

Cross Sections Fall 2009, Department Of Physics And Astronomy

Cross Sections

No abstract provided.

Experimental Studies Of Exotic Negative Ions, Shaun Gerald Ard

Doctoral Dissertations

Although negative ions have been studied extensively for quite some time, their study continues to offer insight into developing and refining quantum chemical modeling techniques. Negative ion states remain difficult to treat ab initio due to the significant electron-electron correlation, thus putting a premium on experimental results to guide the way. Experimental techniques such as Electrospray Ionization (ESI) and Rydberg Electron Transfer (RET) have made study of some exotic negative ions in the gas phase possible for the first time. Multiply Charged Anions (MCAs) of several families of molecules were studied using Collision Induced Dissociation (CID) and Infrared Multi Photon …

Single Walled Carbon Nanotube Networks As Transparent Conductors, Matthew Patrick Garrett

Doctoral Dissertations

A variety of technological applications depend on transparent conducting films, and carbon nanotubes have the properties required to serve in that role. Single-walled carbon nanotube networks have been studied as transparent conductors in order to understand and optimize their electrical and optical properties. Nanotube films are complex networks of semiconducting and metallic nanotubes, bundled and branched in multifarious directions, with different strength connections between bundles. Chemical modification of nanotubes and inclusion of non-nanotube material can further alter network properties. Separating the contributions of all aspects of the network is a necessary but daunting task in order to optimize nanotube films. …

Optical Modeling Of Schematic Eyes And The Ophthalmic Applications, Bo Tan

Doctoral Dissertations

The objectives of this dissertation are to advance and broaden the traditional average eye modeling technique by two extensions: 1) population-based and personalized eye modeling for both normal and diseased conditions, and 2) demonstration of applications of this pioneering eye modeling.The first type of representative eye modeling can be established using traditional eye modeling techniques with statistical biometric information of the targeted population. Ocular biometry parameters can be mathematically assigned according to the distribution functions and correlations between parameters. For example, the axial dimension of the eye relates to age, gender, and body height factors. With the investigation results from …

Multiscale Modeling Of The Electronic, Optical, And Magnetic Properties Of Low-Dimensional Metal Systems, Ke Zhao

Doctoral Dissertations

This thesis presents a study of the electronic, optical and magnetic properties of low-dimensional metal systems across multiple scales, using a variety of theoretical techniques including microscopic phenomenological model, ab initio density functional theory (DFT) and classical electromagnetics.

In the study of the interaction between a molecule and metal substrate, a new mechanism of the chemical enhancement for surface-enhanced Raman scattering (SERS) was discovered. Through a microscopic phenomenological model, it has been demonstrated that 102-104 chemical enhancement may originate from the coupling between an electric field parallel to the surface of a metal substrate and the perpendicular vibration mode of …

Search For Electron Antineutrinos From The Sun With Kamland Detector, Oleg Victorovic Perevozchikov

Doctoral Dissertations

In this dissertation I present the results of the search for the electron antineutrinos from the Sun with Kamioka Liquid scintillator Anti-Neutrino Detector (KamLAND). There is no known direct production of the electron antineutrinos in the Sun. However, in the some theoretical models with the large neutrino magnetic moment antineutrinos from the Sun can be produced e.g. via Spin Flavor Precession mechanism (SFP). Search for solar antineutrinos potentially can provide new information about fundamental properties of neutrinos. The most sensitive one-kiloton antineutrino detector KamLAND gives the possibility to search for such antineutrinos.

The analysis described in this dissertation is based …

Studies On A Polarized Proton Target For Reactions With Radioactive Ion Beams, Juan Pablo Urrego-Blanco

Doctoral Dissertations

Over the last few years, much progress has been made towards the understanding of basic properties of nuclei with extreme neutron to proton ratios. However, the study of phenomena involving spin polarized nuclei near the drip lines remains practically unexplored. The importance of such studies lies in the fact that the most complete knowledge of the scattering matrix is obtained in reactions with polarized particles. The purpose of this dissertation was to explore the feasibility of using polarized probes in reactions with exotic nuclei. We identified areas where reactions between Radioactive Ion Beams (RIBs) and light polarized targets open a …

Geometrical Effects On Electromagnetic Enhancement To Sers From Metal Nanoparticle Dimer Arrays, Abigail Laurel Gaddis

Masters Theses

Much recent effort has been devoted to the study of the optical properties of metal nanoparticle substrates. In such finely ordered structures, surface plasmons can be induced by incident light. These collective excitations of the electrons in the nanoparticle create localized areas of high electromagnetic field intensity. The intense local fields generated are of interest for various applications, including Surface-enhanced Raman Scattering (SERS) for molecular detection and sensing. In this thesis, the optical properties of various nanoparticle dimer and array geometries are considered, including gold triangular prism dimers and silver spherical dimers. The effect of SERS due to electromagnetic interaction …

High-Sensitivity Spectral Fluorescence Lifetime Imaging For Resolving Spectroscopically Overlapping Species, Justin Lee Crawford

Masters Theses

The capability to resolve the contributions from spectroscopically overlapping fluorophores has enabled significant breakthroughs in cellular imaging. However, commercial microscopes for this purpose use analog light detection with least squares curve-fitting analysis and improvements in sensitivity are needed. To this end, a microscope has been constructed with high throughput and single-photon detection capability. The fluorescence is separated through use of a prism spectrometer or a series of dichroic mirrors into four spectral bands and detected using four single-photon avalanche diode (SPAD) detectors, which provide high-quantum efficiency in the red spectral region. The detectors are connected to a time-correlated single photon …

An Automated Approach To The Study And Classification Of Colliding And Interacting Galaxies, Steven Alvaro Boada

Masters Theses

Colliding galaxies are perhaps the greatest events changing and evolving our Universe. Consequently, the need for an understanding of how that interaction originated is very important. This thesis presents a framework in which the study of these events can be conducted in a timely and efficient manner. A genetic algorithm coupled with an initial conditions generator, a physics engine and an analysis package performs an automated search to visually match an unknown galactic interaction with a known event, thus providing the starting conditions that created such an interaction.

Microfluidic Device For The Electrokinetic Manipulation Of Single Molecules, Jason Keith King

Masters Theses

Manipulation and trapping of single molecules in solution is a useful tool for studies of biological molecules and molecular dynamics, but has to date been implemented in only one or two dimensions. The goal of the research in this thesis is to develop a microfluidic device to address the need for three-dimensional manipulation of single fluorescent molecules in solution. The device consists of two pairs of platinum electrodes deposited onto two standard borosilicate glass coverslips via ultraviolet microlithography and ionic sputtering. The two coverslips are sandwiched together such that the electrode tips form a tetrahedral configuration, and by applying appropriate, …

Single Molecule Detection Of Near-Infrared Phthalocyanine Dyes, You Li

Masters Theses

The major advantage associated with near-infrared monitoring is the fact that few compounds show intrinsic fluorescence in this region of the spectrum and hence background from other molecules is reduced. Phthalocyanine dyes provide emission at deep red and near infrared wavelengths but have excellent photostability and hence are an attractive candidate for near-infrared fluorescence bioassay applications. However, because of their small Stokes shifts, non-standard methods are needed for optimum separation of fluorescence from scattered laser light. This thesis reports the development of a custom confocal microscope that uses a lowcost laser diode operating at 667 nm for sample excitation and …

High Energy Particle Physics At The University Of Tennessee, Stefan M Spanier

Physics and Astronomy Publications and Other Works

Talk given at the Governor's school in 2009. It is an introduction to particle physics.

Novel Approach To Ocular Photoscreening, Kevin Charles Baker

Doctoral Dissertations

Photoscreening is a technique that is typically applied in mass pediatric vision screening due to advantage of its objective, binocular, and cost-effective nature. Through the retinal reflex image, ocular alignment and refractive status are evaluated. In the USA, this method has screened millions of preschool children in the past years. Nevertheless, the efficiency of the screening has been contentious. In this dissertation, the technique is reviewed and reexamined. Revisions of photoscreening technique are developed to detect and quantify strabismus, refractive errors, and high-order ocular aberrations. These new optical designs overcome traditional design deficiencies in three areas:

First, a Dynamic Hirschberg …

Cross Sections Spring 2009, Department Of Physics And Astronomy

Cross Sections

No abstract provided.

A Trip To The Beginning Of The Universe With The Large Hadron Collider, Stefan M Spanier

Physics and Astronomy Publications and Other Works

Slides from a presentation given at the Science Forum of the University of Tennessee. It discusses the physics program of the Large Hadron Collider in general terms. Serves as introductory material to the field.