Physical Sciences and Mathematics Commons^™

Students' Reasoning With Haptic Technologies: A Qualitative Study In The Electromagnetism Domain, Sadhana Balachandran

Open Access Theses

With abundant applications in the medical training and entertainment industry, haptic technology is slowly making its way into the realm of science education, particularly in conveying abstract and non-visible concepts. Electric field is one such abstract concept. Past studies have shown that learning concepts such as electric fields in a traditional classroom can be quite challenging since students have a hard time visualizing the phenomena and applying its effects to reason. Furthermore, these concepts are the building blocks for more complex concepts such as matter and molecular interactions. Visuo-haptic devices provide a great platform to enable students to visualize and …

Ab Initio Based State Specific Modeling Of N2+O System, Han Luo

Open Access Theses

Nitrogen and atomic oxygen play an important role in high temperature gas systems. Their Zeldovich reaction product nitric oxide not only affects aerothermal loads and emissions of hypersonic vehicles, but also has the possibility to influence the efficiency of hypersonic propulsion. Atomic oxygen induced nitrogen dissociation is another reaction mechanism of the N2+O system. However, due to the difficulty of conducting ground tests, there are no experimental data for this reaction now. Thermo-chemical nonequilibrium could make the problem more difficult since experiments could only track macroscopic gas properties instead of internal energy distribution. On the other hand, current reaction and …

Applications Of The Homotopy Analysis Method To Optimal Control Problems, Shubham Singh

Open Access Theses

Traditionally, trajectory optimization for aerospace applications has been performed using either direct or indirect methods. Indirect methods produce highly accurate solutions but suer from a small convergence region, requiring initial guesses close to the optimal solution. In past two decades, a new series of analytical approximation methods have been used for solving systems of dierential equations and boundary value problems.

The Homotopy Analysis Method (HAM) is one such method which has been used to solve typical boundary value problems in nance, science, and engineering. In this investigation, a methodology is created to solve indirect trajectory optimization problems using the Homotopy …

Model-Free Variable Screening, Sparse Regression Analysis And Other Applications With Optimal Transformations, Qiming Huang

Open Access Dissertations

Variable screening and variable selection methods play important roles in modeling high dimensional data. Variable screening is the process of filtering out irrelevant variables, with the aim to reduce the dimensionality from ultrahigh to high while retaining all important variables. Variable selection is the process of selecting a subset of relevant variables for use in model construction. The main theme of this thesis is to develop variable screening and variable selection methods for high dimensional data analysis. In particular, we will present two relevant methods for variable screening and selection under a unified framework based on optimal transformations.

In the …

Maximum Empirical Likelihood Estimation In U-Statistics Based General Estimating Equations, Lingnan Li

Open Access Dissertations

In the first part of this thesis, we study maximum empirical likelihood estimates (MELE's) in U-statistics based general estimating equations (UGEE's). Our technical maneuver is the jackknife empirical likelihood (JEL) approach. We give the local uniform asymptotic normality condition for the log-JEL for UGEE's. We derive the estimating equations for finding MELE's and provide their asymptotic normality. We obtain easy MELE's which have less computational burden than the usual MELE's and can be easily implemented using existing software. We investigate the use of side information of the data to improve efficiency. We exhibit that the MELE's are fully efficient, and …

Measurement Of The Upsilon(Ns) Cross Section At Cdf, Michael D. Meier

Open Access Dissertations

Since the bound bb¯ system was first discovered, researchers have been trying to explain the production mechanism for quarkonium to learn more about this system. Several different theories try to describe quarkonium production, and while these theories agree with experimental measurements of production rates, theoretical predictions for quarkonium polarization vary. Careful measurement of the ϒ( nS) angular distribution along with the ϒ(nS) cross section can provide insight into the quarkonium production mechanism. This analysis measures the ϒ(nS) cross section and ϒ(1 S) polarization parameters.

Investigation Of Cellular Microenvironments And Heterogeneity With Biodynamic Imaging, Daniel Alexander Merrill

Open Access Dissertations

Imaging of biological tissue in a relevant environment is critical to accurately assessing the effectiveness of chemotherapeutic agents in combatting cancer. Though many three-dimensional (3D) culture models exist, conventional in vitro assays continue to use two-dimensional (2D) cultures because of the difficulty in imaging through deep tissue. 3D tomographic imaging techniques exist and are being used in the development of 3D efficacy assays. However, most of these assays look at therapy endpoint (dead or living cancer cell count) and do not capture the dynamics of tissue response.

Biodynamic imaging (BDI) is a 3D tomographic imaging and assay technique that uses …

Multivariate Statistical Methods That Enable Fast Raman Spectroscopy, Owen G. Rehrauer

Open Access Dissertations

Raman spectroscopy is a useful tool in investigating inter- and intra-molecular interactions as well as classifying and quantifying chemical species in a sample. Many materials of societal interest, such as proteins and pharmaceuticals, have distinctive Raman spectra with sharp features. However, the adoption of Raman spectra has been hindered by the low rate of Raman scattering, interference from fluorescence, and high spectrometer costs. This work demonstrates multivariate stastical methods that enable fast Raman measurements, despite the low rate of Raman scattering. These methods include a novel type of spectrometer, that uses computer-controlled optical filters to efficiently capture Raman photons and …

Localization And Delocalization In Two-Dimensional Quantum Percolation, Brianna S. Dillon Thomas

Open Access Dissertations

Quantum percolation is one of several disorder-only models that address the question of whether conduction, or more generally, delocalization, is possible in two dimensional disordered systems. Whether quantum percolation exhibits a delocalization-localization phase transition in two dimensions is an ongoing debate, but many recent studies point toward there being a delocalized phase at non-zero disorder, in contradiction to the behavior of the Anderson model, another disorder-only model. In this dissertation, I present my research on quantum percolation that shows a delocalized state is possible, both on isotropic lattices and on highly anisotropic lattices, and shows that the essential characteristics of …

Particle Modeling Of Non-Equilibrium Field Emission Driven Rf Microplasmas, Siva Sashank Tholeti

Open Access Dissertations

Non-equilibrium microplasmas at atmospheric pressures have been investigated for active flow control, micropropulsion and electronic display applications to name a few. The operational voltages for these microplasmas are on the order of kilovolts. When the electric field at the electrodes reaches GV/m or tens of GV/m either due to reduced interelectrode spacing and surface irregularities or due to carefully designed nanostructures on the electrodes, quantum processes such as field emission and field ionization come into effect. These can potentially reduce the operational voltages of microplasma devices by an order of magnitude. Due to the rarefied and non-equilibrium nature of these …

Ultracold Quantum Scattering In The Presence Of Synthetic Spin-Orbit Coupling, Su-Ju Wang

Open Access Dissertations

Two-body scattering constitutes one of the most fundamental processes in various physical systems ranging from ultracold dilute quantum gases to energetic quark- gluon plasmas. In this dissertation, we study the low-energy atomic collision physics in the presence of synthetic gauge fields, which are generated by atom-light interaction. One category of synthetic gauge fields is the artificial spin-orbit coupling. We discuss three different aspects in scattering theory: ultracold collision, scattering resonance, and bound state formation from a few-body perspective when the atomic spin states are coupled with their center-of-mass motion. The understanding of the spin-orbit effects on the modification of the …

Quantum Coherence And Entanglement In Open Quantum Systems, Yiteng Zhang

Open Access Dissertations

We humans always want to believe that we can overpower nature. However, the reality is that nature outperforms humans in many aspects. Animals' abilities to navigate/orient and photosynthesis are two excellent examples in these aspects. However, the mechanisms underlying them are still unknown. For decades, scientists and researchers have made a lot of efforts to reveal these mysteries in nature.

Recently, quantum coherence and entanglement are believed to play a crucial role in such biological systems–avian compass and photosynthesis. Thus, nature might know more tricks to utilize quantum mechanics than humans. Studies on the mechanisms underlying avian compass and photosynthesis …

Mathematical Models Of Ebola Virus Disease And Vaccine Preventable Diseases, Yinqiang Zheng

Open Access Dissertations

This thesis focuses on applying mathematical models to studies on the transmission dynamics and control interventions of infectious diseases such as Ebola virus disease and vaccine preventable diseases.

Many models in studies of Ebola transmission are based on the model by Legrand et al. (2007). However, there are potential issues with the Legrand model. First, the model was originally formulated in a complex form, leading to confusion and hindering its uses in practice. To overcome the difficulty, the Legrand model is reformulated in a much simpler but equivalent form in this thesis. The reformulated model also provides an intuitive understanding …

Enhancing Silymarin Fractionation Via Molecular Modeling Using The Conductor-Like Screening Model For Real Solvents, Emma C. Brace

Open Access Theses

The market for bio-based products from plant sources is on the rise. There is a global challenge to implement environmentally clean practices for the production of fuels and pharmaceuticals from sustainable resources. A significant hurdle for discovery of comparable plant-derived products is the extensive volume of trial-and-error experimentation required. To alleviate the experimental burden, a quantum mechanics based molecular modeling approach known as the COnductor-like Screening Model for Real Solvents (COSMO-RS) was used to predict the best biphasic solvent system to purify silymarins from an aqueous mixture. Silymarins are a class of flavonolignans present in milk thistle ( Silybum marianum …

Development Of A Novel Polymer-Garnet Solid State Composite Electrolyte Incorporating Li-La-Zr-Bi-O And Polyethylene Oxide, Muhammed Ramazan Oduncu

Open Access Theses

Current lithium ion batteries are comprised of organic liquid electrolytes - a mixture of lithium salts and binary solvents such as ethylene carbonate (EC) and dimethyl carbonate (DMC). The main drawbacks of this liquid mixture related to safety are flammability of the organic solvents and chemical instability with the electrode materials. To date, various ceramic and polymer materials have been considered which overcome safety issues. However, a common problem of these solid state materials is that they are not able to provide high ionic conductivity at ambient temperatures. Garnet-type cubic Li7La 3Zr2O12 ceramic material has attracted much interest because of …

Polymerizable Lipids For Controlled Functionalization Of Layered Materials, Kortney Kaye Rupp

Open Access Theses

Self-assembled monolayers (SAM’s) offer a straightforward approach to tailoring the interfacial properties of metals, metal oxides and semiconductors. Noncovalent functionalization of single-layer graphene offers the possibility to finely tune surface chemistry for future applications in electronics. Polymerization of photochemically reactive molecules in a lying-down phase has been used to increase the strength of intermolecular interactions between long alkanes and HOPG substrates. Long-chain fatty acid derivatives with internal diyne groups yield a conjugated ene-yne polymer upon UV irradiation. Diyne lipids with phosphocholine (diyne PC) and phosphoethanolamine (diyne PE) groups offer a charged form of the head group that is robust towards …

Metal-Promoted Self-Assembly Of Collagen Mimetic Peptides Into Biofunctional Scaffolds For Stem Cell Delivery With The Aim Of Tissue Regeneration, Kevin Strauss

Open Access Theses

Collagen is a strong, sturdy, but malleable, protein found abundantly in the extracellular matrix. Consequently, it has become an invaluable biomaterial for use in regenerative medicine. However, natural collagen poses difficulties when it comes to customization and structural control, as well as the risk of infectious prions from animal sources. Our approach utilizes shorter, synthetic collagen mimetic peptide sequences. These peptides retain the incredible triple helical stability of natural collagen but can be modified with versatile metal-binding ligands. In the presence of an appropriate metal ion, the peptides self-assemble into diverse, three-dimensional morphologies. The peptide NCoH, functionalized with N-terminal NTA …

Investigation Of The Interaction Of Dimeric Ruthenium Complexes With Cytochrome B5, Christopher Dain Rupar

Graduate Theses and Dissertations

Photoreactive complexes to study the kinetics of electron transfer of proteins have been in use for a long time. It has always been speculated that complexes bind near the heme or the electron transfer reaction would not occur. But it is unkown exactly how the complex interacts with the protein. The structural, thermodynamic, and kinetic properties of rat liver microsomal cytochrome b5 were investigated when bound to ruthenium dimer complexes. Heteronuclear Single Quantum Coherence studies support a dynamic binding model of a dimer Ru complex bound near the protein’s heme involving residues H39, E44, G42, V61, G62, and H63. The …

Studies In The Asymmetric Synthesis Of The C21-C34 Fragment Of The Natural Product, Antascomicin B, Brian Lee Walker

Graduate Theses and Dissertations

This dissertation describes studies in the asymmetric synthesis of the C21 – C34 fragment of the natural product, antascomicin B. Antascomicin B is structurally related to FK506, binds strongly to FKBP12, yet does not shown immunosuppressive activity. Small ligand FKBP12 binding complexes were shown to have potent neuroprotective and neuroregenerative properties in mouse models of Parkinson’s disease. The highlighted chemical reactions include an asymmetric transfer hydrogenation (ATH), Ireland-Claisen rearrangement (ICR), directed hydrogenation and allylic diazene rearrangement.

Photoluminescence Measurement On Low-Temperature Metal Modulation Epitaxy Grown Gan, Yang Wu

Graduate Theses and Dissertations

A low-temperature photoluminescence (PL) study was conducted on low-temperature metal modulation epitaxy (MME) grown GaN. By comparing the PL signal from high temperature grown GaN buffer layers, and MME grown cap layers on top of the buffer layers, it was found that MME grown GaN cap has a significantly greater defect-related emission. The band edge PL from MME grown GaN found to be 3.51eV at low temperature. The binding energy of the exciton in GaN is determined to be 21meV through temperature dependence analysis. A PL peak at 3.29eV was found in the luminescence of the MME grown cap layer, …

On Compactness And Closed-Rangeness Of Composition Operators, Arnab Dutta

Graduate Theses and Dissertations

Let $\phi$ be an analytic self-map of the unit disk $\mathbb{D}:=\{z:\lvert z\rvert

Conformally Invariant Operators In Higher Spin Spaces, Chao Ding

Graduate Theses and Dissertations

In this dissertation, we complete the work of constructing arbitrary order conformally invariant operators in higher spin spaces, where functions take values in irreducible representations of Spin groups. We provide explicit formulas for them.

We first construct the Dirac operator and Rarita-Schwinger operator as Stein Weiss type operators. This motivates us to consider representation theory in higher spin spaces. We provide corrections to the proof of conformal invariance of the Rarita-Schwinger operator in [15]. With the techniques used in the second order case [7, 18], we construct conformally invariant differential operators of arbitrary order with the target space being degree-1 …

Study Of Plasmonic Properties Of The Gold Nanorods In The Visible To Near Infrared Light Regime, Pijush Kanti Ghosh

Graduate Theses and Dissertations

Nanostructures of noble metals show unique plasmonic behavior in the visible to near-infrared light range. Gold nanostructures exhibit a particularly strong plasmonic response for these wavelengths of light. In this study we have investigated optical enhancement and absorption of gold nanorods with different thickness using finite element method simulations. This study reports on the resonance wavelength of the sharp-corner and round-corner rectangles of constant length 100 nm and width 60 nm. The result shows that resonance wavelength depends on the polarization of the incident light; there also exists a strong dependence of the optical enhancement and absorption on the thickness …

Two Studies: Stereoselective C-C Bond Formations Of N-Boc-Piperidines Using Selected Organolithiums And Visible-Light-Mediated Synthesis Of Fused Indolines Using Tethered Styrenes, Scott Alan Morris

Graduate Theses and Dissertations

Chemists worldwide have accepted the challenge of developing methods to access a variety of compounds as single enantiomers, including the use of enzymes, chiral auxiliaries, and resolutions. In particular, dynamic resolutions offer a unique way to access chiral compounds using a few controllable steps, including the variation of both time and temperature. Many groups have implemented this methodology to generate various polysubstituted pyrrolidines and piperidines, which are substructures ranking high on the list of nitrogen–containing pharmaceuticals.

The Gawley group revealed a catalytic dynamic resolution (CDR) of N–Boc–piperidine using a chiral ligand. Impressively, the chemistry was tolerant of a variety of …

Mechanism Of Rapid Electron Transfer Reactions Involving Cytochrome Bc1, Cytochrome C And Cytochrome Oxidase, Jeremy Erik Durchman

Graduate Theses and Dissertations

Electron transfer between mitochondrial proteins complexes represents the primary means by which living things acquire the requisite energy for survival. The coupling of electron transfer to proton translocation creates an electrochemical gradient that drives the synthesis of highly energetic compounds such as ATP. The purpose of these studies is to measure rates of electron transfer and elucidate the important governing factors in the redox events involving cytochrome bc1, cytochrome c and cytochrome oxidase. Using rapid initiation of redox events triggered by laser flash excitation of ruthenium compounds, and strategically monitoring unique spectral properties of these proteins in the visible region …

Sparse Representation For The Isar Image Reconstruction, Mengqi Hu

Theses and Dissertations

In this paper, a sparse representation for the data form a multi-input multi-output based inverse synthetic aperture radar (ISAR) system is derived for two dimensions. The proposed sparse representation motivates the use a of a Convex Optimization directly that recovers the image without the loss information of the image with far less samples that that is required by Nyquist–Shannon sampling theorem, which increases the efficiency and decrease the cost of calculation in radar imaging.

Lie Symmetry To Second-Order Nonlinear Differential Equations And Its First Integrals, Pengfei Gu

Theses and Dissertations

There are many well-known techniques for obtaining exact solutions of differential equations, but most of them are merely special cases of a few powerful symmetry methods. In this paper, we focus our attention on a second-order nonlinear ordinary differential equation of special forms with arbitrary parameters, which is a combination of Liénard-type equation and equation with quadratic friction. With the help of Lie Symmetry methods, we identify several integrable cases of this equation. And for each case, we use the Lie Symmetry method to derive the associated determining system, and apply it further to find infinitesimal generators under …

Does Lowest Order Perturbation Of Λ Affect Ligo Detection?, Shuang Liang

Theses and Dissertations

Gravitational waves under the effect of a positive Cosmological Constant Λ has been a long time puzzle. To date, the full wave solution is still under construction, while attempts have been made to solve the linearized equations. We present a detailed derivative of the linearized Einstein’s Equations in a covariant manner, then solve for a lowest order perturbation in Λ. Results suggest that the Cosmological Constant has a large contribution to the phase of gravitational waves, which might be detectable.

A Comparative Study And Data Analysis For The Ultimate Fighting Championship, Victor Villalpando

Theses and Dissertations

Mixed Martial Arts is the fastest growing sport with many organizations worldwide. The biggest stage or biggest organization for Mixed Martial Arts is the Ultimate Fighting Championship (UFC). There are eight weight classes for men. The website: http://www.foxsports.com/ufc/stats provides data on fighters in all these categories. This data measures Striking Accuracy, Take downs, Reversals, Knockdowns, etc. in each category. It is interesting to understand and interpret all these numbers and study their relationships. Statistical tools like both parametric and nonparametric inference may give rise to such interpretations and provide explanations how the weight classes differ from one another. In this …

[3+2] Annulation Of Cyclopropylanilines With Alkynes Under Photocatalysis, Theresa Ha Nguyen

Graduate Theses and Dissertations

Over the past decade, pharmaceutical industries have prioritized their focus on discovering new innovative drugs, yet the syntheses are often either inefficient or the approach of environmental sustainability presents a great deal of concern. Moreover, the methodology developments for amine syntheses have continued to flourish due to their important role and wide use in pharmaceutics. Yet their syntheses often lack sustainability and efficiency. Synthetic chemists have continued to explore potential innovative avenues for conducting chemical reactions more effectively and efficiently. One of the most abundant, renewable natural resources is solar energy and to harvest, use, and store it directly is …