Physical Sciences and Mathematics Commons^™

Depth-Resolved Multispectral Sub-Surface Imaging Using Multifunctional Upconversion Phosphors With Paramagnetic Properties, Zaven Ovanesyan, L. Christopher Mimun, Gangadharan Ajith Kumar, Brian G. Yust, Chamath Dannongoda, Karen S. Martirosyan, Dhiraj K. Sardar

Physics and Astronomy Faculty Publications and Presentations

Molecular imaging is very promising technique used for surgical guidance, which requires advancements related to properties of imaging agents and subsequent data retrieval methods from measured multispectral images. In this article, an upconversion material is introduced for subsurface near-infrared imaging and for the depth recovery of the material embedded below the biological tissue. The results confirm significant correlation between the analytical depth estimate of the material under the tissue and the measured ratio of emitted light from the material at two different wavelengths. Experiments with biological tissue samples demonstrate depth resolved imaging using the rare earth doped multifunctional phosphors. In …

Effects Of Aerosol On Cloud Water Path: Statistical Method A Potential Source For Divergence In Observation-Based Correlative Studies, Ousmane Sy Savane

Dissertations, Theses, and Capstone Projects

Divergence between correlative studies involving aerosol and cloud proxies has been thought of in the past as the results of varying physical mechanisms. Although models have supported the existence of variable correlations, from an observational standpoint it is difficult to attribute with confidence the correlations to specific physical mechanisms. We explore a methodology to assess the correlation between cloud water path (CWP) and aerosol optical depth (AOD) using MODIS Aqua retrieved aerosol and cloud properties for regions dominated by different types of aerosol: Non Absorbing Aerosol Dominated Region over land (NAADR_Land), Non Absorbing Aerosol Dominated Region over Ocean (NAADR_Marine), Absorbing …

The Moduli Space Of Rational Maps, Lloyd William West

Dissertations, Theses, and Capstone Projects

We construct the moduli space, M_d, of degree d rational maps on ℙ¹ in terms of invariants of binary forms. We apply this construction to give explicit invariants and equations for M₃.

Using this construction, we give a method for solving the following problems: (1) explicitly construct, from a moduli point P ∈ M_d(k), a rational map ∅ with the given moduli; (2) find the field of definition of a rational map ∅. We work out the method in detail for the case d = 3.

Optimal Measurements Tasks And Their Physical Realizations, Vadim Yerokhin

Dissertations, Theses, and Capstone Projects

This thesis reflects works previously published by the author and materials hitherto unpublished on the subject of quantum information theory. Particularly, results in optimal discrimination, cloning, and separation of quantum states, and their relationships, are discussed.

Our interest lies in the scenario where we are given one of two quantum states prepared with a known a-priori probability. We are given full information about the states and are assigned the task of performing an optimal measurement on the incoming state. Given that none of these tasks is in general possible to perform perfectly we must choose a figure of merit to …

Accurate Deterministic Solutions For The Classic Boltzmann Shock Profile, Yubei Yue

Dissertations, Theses, and Capstone Projects

The Boltzmann equation or Boltzmann transport equation is a classical kinetic equation devised by Ludwig Boltzmann in 1872. It is regarded as a fundamental law in rarefied gas dynamics. Rather than using macroscopic quantities such as density, temperature, and pressure to describe the underlying physics, the Boltzmann equation uses a distribution function in phase space to describe the physical system, and all the macroscopic quantities are weighted averages of the distribution function. The information contained in the Boltzmann equation is surprisingly rich, and the Euler and Navier-Stokes equations of fluid dynamics can be derived from it using series expansions. Moreover, …

Friction, Avalanches And Phase Transitions In Granular Media., Aline Hubard

Dissertations, Theses, and Capstone Projects

We explore the microscopic interactions and properties of dry granular materials in the plane using experiments and simulations. We use statistics of this microscopic information to better understand and predict the bulk behavior and evolution of granular materials.

In the first part, we study the geometric structure of mechanically stable packings of frictional disks in configuration space. Our experimental setup contains frictional disks confined in a vertical plane and subject to a series of small amplitude vibrations that compact the system by reducing the friction between contacts during each vibration step. We find that the evolution of the packings forms …

Another One Busts The Dust, Keiko Hiranaka

Dissertations, Theses, and Capstone Projects

Brown dwarfs are substellar objects with core temperatures insufficient for sustained hydrogen fusion. Their physical properties such as mass, temperature, and radius are similar to those of gas giant planets, so studying brown dwarfs may also benefit exoplanet studies.

There is a population of 'red' L dwarfs, which have redder J - K colors in the near-infrared than normal objects. Red L dwarfs include young, low-gravity objects, which are systematically red, and red field-gravity objects. The observed reddening in L dwarfs is not well explained by current atmosphere models.

We present an analysis of red L dwarfs using our model …

Eastern Tropical Pacific Climate And El Niño Variability During The Past Millennium, Gerald Thomas Rustic

Dissertations, Theses, and Capstone Projects

The El Niño Southern Oscillation (ENSO) has been implicated in large-scale climate shifts of the past millennia, but paleoclimate records from the dynamically vital eastern equatorial Pacific Ocean (EEP) spanning the past millennium are sparse. This has limited our understanding of tropical Pacific dynamics, leaving questions regarding the source of ENSO variability unanswered. Here I seek to address some of these questions regarding relationship between ENSO and tropical Pacific mean state, and the relationship between the tropical Pacific and large-scale climate. Mean EEP sea surface temperature (SST) for the past millennium was reconstructed using Mg/Ca ratios in Globigerinoides ruber from …

Zirconium-89: Radiochemistry And Ligand Development Toward Improved Pet Applications, Melissa Ann Deri

Dissertations, Theses, and Capstone Projects

Antibodies are attractive targeting vectors for positron emission tomography (PET) based imaging agents due to their high affinity and selectivity to a variety of biological targets. Creating such imaging agents requires a radionuclide with suitable decay characteristics. This role has been filled by zirconium-89 which has a 78.41 h half-life that ideally matches the multi-day biological half-life of IgG antibodies.

However, the use of a radiometal necessitates the use of a bifunctional chelator to bind the metal and conjugate to the antibody. For ⁸⁹Zr this has been the purview of various derivatives of desferrioxamine B (DFO); however, the observed …

Growth And Characterization Of Type-Ii Submonolayer Zncdte/Zncdse Quantum Dot Superlattices For Efficient Intermediate Band Solar Cells, Siddharth Dhomkar

Dissertations, Theses, and Capstone Projects

In this thesis, we discuss the growth procedure and the characterization results obtained for epitaxially grown submonolayer type-II quantum dot superlattices made of II-VI semiconductors. The goal behind this study is to show the feasibility of this novel material system in fabricating an efficient intermediate band solar cell.

Intermediate band solar cells can potentially have an efficiency of 63.2% under full solar concentration, but the material systems investigated until now are far from optimum and are fraught with growth related issues including low quantum dot densities, presence of wetting layers, strain driven dislocations etc. Here, we have investigated a novel …

Metasurfaces For Photon Sorting And Selective Absorption, Isroel Moshe Mandel

Dissertations, Theses, and Capstone Projects

Metamaterials are a recent discovery gaining much interest due to their promising applications to multiple devices in sensing, imaging, photovoltaics, nonlinear optics, heat conversion, sorters, and multitudes of other devices. These metamaterials are made of subunits called meta-atoms which take a role similar to that of atoms in bulk crystals. However, unlike their atom counterparts, these meta-atoms are macroscopic and can be engineered to respond to a driving field in a desired way. Metasurfaces, the 2-dimensional analog of metamaterials, have been shown to possess the ability to control light in novel ways. In this work, we investigate a particular type …

Studies Toward A General Synthesis Of Poly-Substituted Alpha-Hydroxytropolones, Christine Marie Meck

Dissertations, Theses, and Capstone Projects

Chapter 1: This chapter gives a brief history of α-hydroxytropolones, how they were discovered and unique properties of these substrates. Included is a background on the bioactivity of these substrates in cellular targets such as bacteria, fungi, parasites, tumors and toxicity, as well as their ability to inhibit various metallo-based enzymes. Structure activity relationships studies are reviewed on important metalloenzymes HIV-Reverse Transcriptase (RT) and Inositol monophosphatase (IMPase). Finally the chapter finishes with a synthetic overview of α-hydroxytropolones including natural product targets such as puberulic acid, puberulonic acid, β-thujaplicinol, and β-hydroxytropolone.

Chapter 2: A brief review on β-hydroxy-γ-pyrone based oxidopyrylium cycloadditions …

On String Topology Operations And Algebraic Structures On Hochschild Complexes, Manuel Rivera

Dissertations, Theses, and Capstone Projects

The field of string topology is concerned with the algebraic structure of spaces of paths and loops on a manifold. It was born with Chas and Sullivan's observation of the fact that the intersection product on the homology of a smooth manifold $M$ can be combined with the concatenation product on the homology of the based loop space on $M$ to obtain a new product on the homology of $LM$, the space of free loops on $M$. Since then, a vast family of operations on the homology of $LM$ have been discovered.

In this thesis we focus our attention on …

Some Bernstein Type Results Of Graphical Self-Shrinkers With High Codimension In Euclidean Space, Hengyu Zhou

Dissertations, Theses, and Capstone Projects

A self-shrinker characterizes the type I singularity of the mean curvature flow. In this thesis we concern about some Bernstein type results of graphical self-shrinkers with high codimension in Euclidean space.

There are two main tools in our work. The first one is structure equations of graphical self-shriners in terms of parallel forms (Theorem 2.3.6). This is motivated by M.T.Wang's work ([Wan02]) on graphical mean curvature flows with arbitrary codimension in product manifolds. The second one is an integration technique (Lemma 2.4.5) based on the fact that every graphical graphical self-shrinker has the polynomial volume growth (Corollary 2.4.4). Because of …

Order And Asymmetry In Jammed Systems, Zhusong Li

Dissertations, Theses, and Capstone Projects

Granular matter is composed of particles that are big enough that thermal effects may be neglected. We studied both granular flow and granular statics using numerical simulation. In granular flow, we simulated 2D granular flow in a hopper. A hopper is a container with an opening at the bottom. Simulated disks are placed in the hopper with the bottom closed and then released. We developed a new tangential force model to simulate hopper flow, that matches experiments and shows that the output flux is proportional to the bottom opening size to the 3/2 power. We also see clogging or jamming …

The Geometry And Combinatorics Of Closed Geodesics On Hyperbolic Surfaces, Chris Arettines

Dissertations, Theses, and Capstone Projects

In this thesis, we obtain combinatorial algorithms that determine the minimal number of self-intersections necessary for a free homotopy class $[\gamma]$ on an orientable surface, using algebraic input. Using this same input, we describe another algorithm which determines whether or not a minimally intersecting curve in $[\gamma]$ is \textit{filling}, that is, whether or not the complement is a disjoint union of disks or punctured disks. Next, we use these algorithms as inspiration for proving the existence of filling curves which self-intersect $2g-1$ times, which is the minimal number of intersections possible. The combinatorial viewpoint that is developed can then be …

Counting Restricted Integer Partitions, David Dakota Blair

Dissertations, Theses, and Capstone Projects

The first chapter examines $p_b(n)$, the number of partitions of $n$ into powers of $b$, along with a family of identities which can be deduced by iterating a recurrence satisfied by $p_b(n)$ in a suitable way. These identities can then be used to calculate $p_b(n)$ for large values of $n$.

The second chapter restricts these types of partitions even further, limiting the multiplicity of each part. Its object of study is $p_{b,d}(n)$, that is, the number of partitions of $n$ into powers of $b$ repeating each power at most $d$ times. The methods of the first chapter are applied, and …

Equations Over Hyperbolic Groups, Alexander Kai-Chi Taam

Dissertations, Theses, and Capstone Projects

We show that the Diophantine problem, for quadratic equations over a non-elementary torsion-free hyperbolic group, is NP-complete. Furthermore, given a finite system of equations over a torsion-free hyperbolic group $\Gamma$, there is an algorithm which constructs a canonical $Hom$-diagram and a complete set of induced $\Gamma$-NTQ systems, for $\Gamma_{R(S)}$. Finally, the class of $\Gamma$-limit groups is the same as that of iterated generalized doubles over $\Gamma$.

Biophysical Characterization Of A De Novo Elastin, Kelly Nicole Greenland

Dissertations, Theses, and Capstone Projects

Natural human elastin is found in tissue such as the lungs, arteries, and skin. This protein is formed at birth with no mechanism present to repair or supplement the initial quantity formed. As a result, the functionality and durability of elastin's elasticity is critically important. To date, the mechanics of this ability to stretch and recoil is not fully understood. This study utilizes de novo protein design to create a small library of simplistic versions of elastin-like proteins, demonstrate the elastin-like proteins, maintain elastin's functionality, and inquire into its structure using solution nuclear magnetic resonance (NMR).

Elastin is formed from …

Density Functional Theory For The Investigation Of Transition Metal Complexes: Structure, Binding, And Spectroscopy Of Metal-Siderophores And The Catalase-Peroxidase Enzyme, Bonnie I. Kruft

Dissertations, Theses, and Capstone Projects

Since the development of quantum mechanics in the 1920's and with the introduction of the Schrödinger equation in 1926, various methods to solve the Schrödinger equation have evolved. With advances in these computational methods, we are now able to solve the Schrödinger equation for systems that did not seem possible less than a century ago. Density functional theory (DFT) is a valuable tool for the exploration of the molecular properties of biological systems, and is based upon the theory that the exact energy could be determined from the knowledge of the electron density. The purpose of this dissertation is to …

Algorithmic Properties Of Poly-Z Groups And Secret Sharing Using Non-Commutative Groups, Bren Cavallo

Dissertations, Theses, and Capstone Projects

Computational aspects of polycyclic groups have been used to study cryptography since 2004 when Eick and Kahrobaei proposed polycyclic groups as a platform for conjugacy based cryptographic protocols.

In the first chapter we study the conjugacy problem in polycyclic groups and construct a family of torsion-free polycyclic groups where the uniform conjugacy problem over the entire family is at least as hard as the subset sum problem. We further show that the conjugacy problem in these groups is in NP, implying that the uniform conjugacy problem is NP-complete over these groups. This is joint work with Delaram Kahrobaei. We also …

Using Fish Population Metrics To Compare The Effects Of Artificial Reef Density, Catheline Y. M. Froehlich, Richard Kline

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Artificial reefs continue to be added as habitat throughout the world, yet questions remain about how reef design affects fish diversity and abundance. In the present study, the effects of reef density were assessed for fish communities and sizes of economically valuable Lutjanus campechanus 13 km off Port Mansfield, Texas, at a reef composed of more than 4000 concrete culverts. The study spanned from May to June in 2013 and 2014, and sites sampled included natural reefs, bare areas, and varying culvert patch density categories, ranging from 1–190 culverts. Abundances of adults and species evenness of juvenile populations differed between …

Applying A Novel Combination Of Techniques To Develop A Predictive Model For Diabetes Complications, Mohsen Sangi, Khin Than Win, Farid Shirvani, Mohammad-Reza Namazi-Rad, Nagesh Shukla

Nagesh Shukla

No abstract provided.

Population Accessibility To Radiotherapy Services In New South Wales Region Of Australia: A Methodological Contribution, Nagesh Shukla, Rohan Wickramasuriya, Andrew Miller, Pascal Perez

Nagesh Shukla

No abstract provided.

U.S. Drought Monitor, September 29, 2015, Eric Luebehusen

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for September 29, 2015 (9/29/15) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.

Mass Spectrometric Analyses Of Surface Proteins From Candida Albicans After Treatment With Histatin 5, Shirley Fan

Electronic Thesis and Dissertation Repository

Current drug therapies have lost their effectiveness in controlling the fungal species known as C. albicans; therefore, the need for newer drugs becomes crucial. Histatin 5 (Hst 5), a naturally occurring peptide found in the oral cavity, has demonstrated strong effects on controlling candidiasis. Here, we have proposed that the adhesion of cells through surface proteins is an important process. To allow the analysis of surface proteins, the concept of on-whole cell tryptic digestions were developed. This on-target approach allows for isolation of the peptides of interest, while greatly reducing digestion times.

To study the effects of Histatin 5 …

Carbon And Nitrogen Isotopic Investigations Of The Late Pleistocene Paleoecology Of Eastern Beringia, Yukon Territory, Using Soils, Plants And Rodent Bones, Farnoush Tahmasebi

Electronic Thesis and Dissertation Repository

During the late Pleistocene (130-12 ka), Beringia, a largely ice-free land located in the Mammoth Steppe Ecosystem, was home to a large grazing community of megafauna. Many of these animals, including the woolly mammoth, became extinct at the terminal Pleistocene. Assessment of the paleoenvironment, nutrient cycling and foraging ecology in Beringia should help to understand the role of climate change in their extirpation. Such information might also help to explain the curiously higher δ¹⁵N of woolly mammoths relative to other coeval herbivores.

This study assessed eastern Beringian paleoecology using stable nitrogen (N) and carbon (C) isotopic analyses of …

Geology & Geography News, Georgia Southern University

School of Earth, Environment, and Sustainability News (2013-2021)

• Researchers Rescue Sea Turtle

Don't Just Blindly Follow All 'Green' Trends -- Do Your Research First, Michael Bass

UCF Forum

Nowadays it is politically correct to be “green” – to say and do things that seem to minimize one’s impact on the environment and to preach to others to do the same.

Cosm News, Georgia Southern University

College of Science and Mathematics News (2012-2019)

• Researchers Rescue Sea Turtle