Digital Commons Network^™

An Experimental And Computational Evaluation Of The Importance Of Molecular Diffusion In Gas Gravity Currents, Jeremy Jac Herman

Graduate Theses and Dissertations

The accidental release of hazardous, denser-than-air gases during their transport or manufacture is a vital area of study for process safety researchers. This project examines the importance of molecular diffusion on the developing concentration field of a gas gravity current released into a calm environment. Questions which arose from the unexpectedly severe explosion in 2005 at Buncefield, England were of particular interest. The accidental overfilling of a large tank with gasoline on a completely calm morning led to a massive open air explosion. Forensic evidence showed that at the time of ignition, a vapor cloud, most of which now appears …

Developing A Presumptive Test For Select Synthetic Cannabinoids, Carrie Snyder

Graduate Theses and Dissertations

Synthetic cannabinoids (SC's) began to gain popularity around the world in 2009. Since then, many of the compounds have been outlawed and methods developed to detect them and their metabolites using mass spectrometry. Our work investigated the possibility of developing a colorimetric presumptive test. The SC JWH-019 was synthesized and its ketone targeted as a possible reaction site. Many SC's contain ketones and thus a reaction at this site would be applicable to many of the compounds. Since JWH-019 is costly and time consuming to synthesize, much of the experimental work was done using benzophenone (BP). BP contains a diaryl …

Microfluidics Guided By Redox-Magnetohydrodynamics (Mhd) For Lab-On-A-Chip Applications, Vishal Sahore

Graduate Theses and Dissertations

Unique microfluidic control actuated by simply turning off and on microfabricated electrodes in a small-volume system was investigated for lab-on-a-chip applications. This was accomplished using a relatively new pumping technique of redox-magnetohydrodynamics (MHD), which as shown in this dissertation generated the important microfluidic features of flat flow profile and fluid circulation. MHD is driven by the body force, FB = j × B, which is the magnetic part of the Lorentz force equation, and its direction is given by the right hand rule. The ionic current density, j, was generated in an equimolar solution of potassium ferri/ferro cyanide by applying …

Towards The Total Synthesis Of Antascomicin B. Efforts To Construct The C1-C21 Fragment, Juliette Rivero-Castro

Graduate Theses and Dissertations

Antascomicin B is a macrolide isolated from a strain of Micromonospora. It possesses structural similarities to FK506 and rapamycin and exhibits potent binding ability to FKBP12. Recent reports suggest that small molecule ligands of FKBP12 possess potent neuroprotective and neurodegenerative properties in mouse models of Parkinson's disease. Our approach to the C1-21 fragment of antascomicin B involves an asymmetric amino-Claisen rearrangement originally developed by Tsunoda et al.35 report the scalability of the preparation and rearrangement of an allylic amide possessing a silyloxy group at the terminal position of the alkene. The Tsunoda-Claisen rearrangement uses inexpensive (S)-α-methylbenzylamine as the chiral …

Biochemical And Biophysical Studies Of Novel Features Of Ras-Related Protein Interactions, Kyla Marie Morinini Morris

Graduate Theses and Dissertations

The Ras superfamily of G-proteins are of great research interest for structure-function relationships among proteins as they act as molecular switches in the regulation of various biochemical reactions in the cell. They are regulated by protein-protein interactions targeted to the highly flexible switch regions. Mutations in G-proteins or their effectors may cause alterations in structure and/or function that can lead to overactivity.

The Ras-related protein Cell division cycle 42 (Cdc42) is important in regulating cell-signaling processes. The T35A mutation in Cdc42 leads to a decrease in flexibility of the Switch I region responsible for effector binding. The kinetics of the …

The Development Of An In Vivo Microdialysis Collection Method Of Cytokines From Brain Tissue, Anthony W. Herbaugh

Graduate Theses and Dissertations

In this thesis, different methods to improve the microdialysis collection procedure for cytokines from brain tissue are presented. The first method was based on stopped flow and results indicating that no significant difference in relative recovery between stopped flow and continuous flow are shown. The second method is an antibody bead-based enhancement method. With the antibody bead-based method, a 3.5 fold increase in the collected concentrations of Chemokine (C-C motif) Ligand 2 (CCL2) were observed. However, there was no significant increase in the in vivo collection efficiency of Interleukin-6 (IL-6) using the antibody enhancement. Finally the development of an in-house …

Steady-State Switching And Dispersion/Absorption Spectroscopy Of Multistate Atoms Inside An Optical Ring Cavity, Jiteng Sheng

Graduate Theses and Dissertations

This thesis mainly focuses on the experimental investigations of electromagnetically induced transparency (EIT) related phenomena in various systems involving multilevel atoms inside an optical ring cavity. Semiclassical methods, e.g. density-matrix equations, are used through out this thesis to simulate the experimental results. First, the cavity transmission spectrum can be significantly modified when multilevel atoms are placed inside an optical ring cavity. Such coupled atom-cavity systems are well explained by the intracavity dispersion/absorption properties. Specifically, three-level lambda-type, four-level N-type and double-lambda-type atoms inside an optical ring cavity are investigated by examining their cavity transmission spectra. Second, optical multistability (OM) has been …

Monodentate, Bidentate And Photocrosslinkable Thiol Ligands For Improving Aqueous Biocompatible Quantum Dots, Hiroko Takeuchi

Graduate Theses and Dissertations

Water-soluble Quantum Dots (QDs) are highly sensitive fluorescent probes that are often used to study biological species. One of the most common ways to render QDs water-soluble for such applications is to apply hydrophilic thiolated ligands to the QD surface. However, these ligands are labile and can be easily exchanged on the QD surface, which can severely limit their application. As one way to overcome this limitation while maintaining a small colloidal size of QDs, we developed a method to stabilize hydrophilic thiolated ligands on the surface of QDs through the formation of a crosslinked shell using a photocrosslinking approach. …

Excretion Of Phenolic Compounds After Consumption Of Fresh Versus Aged Chokeberry Juice In Rats, Sarah Elizabeth Graves

Graduate Theses and Dissertations

Flavonoids, such as anthocyanins, may be responsible for the health benefits of chokeberries, as they are present in large quantities in chokeberries and are potent antioxidant and anti-inflammatory agents. Despite these health properties, previous investigations on the bioavailability of flavonoids illustrate that little of the ingested amount reaches the bloodstream. This study investigated two factors that may help to explain these inconsistencies. First, storage of berry fruits and berry fruit products leads to extensive polymerization of their anthocyanins with procyanidins. Additionally, after consumption flavonoids may undergo metabolism into phenolic acids and subsequent conjugation to an extent that may explain their …

Structural Properties Of Ferroelectric Lead (Zirconium0.5,Titanium0.5)Oxygen3 Nanotube Array And Electronic Structure Of Lao Delta-Doped Strontium Titanate, Rajendra Prasad Adhikari

Graduate Theses and Dissertations

In this Dissertation we begin with two introductions on: 1) ferroelectricity and related phenomena, and 2) novel properties of Oxide electronics and the generation of two dimensional electron gas. We then give theoretical background of density functional theory (including LDA+U) and pseudopotentials. The first part of research work is about structural, polarization, and dielectric properties of ferroelectric Lead Zirconate Titanate (PZT) solid solution in the form of a nanotube array, embedded in a matrix medium of different ferroelectric strengths. We use the effective Hamiltonian derived from first-principles and finite-temperature Monte Carlo methods to determine the various properties. We revealed different …

Design And Evaluation Of A Fiber Optic Probe As A Means Of Subsurface Planetary Exploration, Robert Paul Pilgrim

Graduate Theses and Dissertations

The Optical Probe for Regolith Analysis (OPRA) is an instrumentation concept designed to provide spectroscopic analysis of the near subsurface of unconsolidated regolith on bodies such as moons, asteroids and planets. Below a chemically altered surface may lay the geological history in the form of stratigraphy that is shielded from degradation due to harsh external environments. Most of what we know about our solar system comes from remote platforms, such as satellites that are deployed into orbit around the target body. In the case of Mars, we have had several successful landers and rovers however, with the exception of the …

The Word Problem For The Automorphism Groups Of Right-Angled Artin Groups Is In P, Carrie Anne Whittle

Graduate Theses and Dissertations

We provide an algorithm which takes any given automorphism f of any given right-angled Artin group G and determines whether or not f is the identity automorphism, thereby solving the word problem for the automorphism groups of right-angled Artin groups. We do this by solving the compressed word problem for right-angled Artin groups, a more general result. A key piece of this solution is the use of Plandowski's algorithm. We also demonstrate that our algorithm runs in polynomial time in the size of the given automorphism, written as a word in Laurence's generators of the automorphism group of the given …

Design, Development, And Characterization Of Novel Antimicrobial Peptides For Pharmaceutical Applications, Yazan H. Akkam

Graduate Theses and Dissertations

Candida species are the fourth leading cause of nosocomial infection. The increased incidence of drug-resistant Candida species has emphasized the need for new antifungal drugs. Histatin 5 is a naturally occurring human salivary antifungal peptide and the first line of defense against infections of the oral cavity. This research has focused on understanding the activity of histatin 5, and subsequently designing novel peptides that may serve as models for the further development of therapeutics to treat fungal infection.

This objective has been achieved in three steps: studying the structural requirement of histatin 5 involved in antifungal activity, the identification of …

Fabrication Of Tungsten Tips Suitable For Scanning Probe Microscopy By Electrochemical Etching Methods, Gobind Basnet

Graduate Theses and Dissertations

The fabrication of metal tips is becoming an interesting field for scientists who are working in spectroscopy measurements. A significant amount of work has already been done in the tips fabrication process. Metal tips used to analyze the surface of materials play a key role in the scanning tunneling microscope (STM) technique. It's remarkable quality that it is used to study the surface of material at the atomic level.

There are various methods used in the tips fabrication process. Of diverse methods, three different electrochemical etching methods: submerged method, single lamella drop-off method, and double lamella drop-off method are commonly …

Modeling Chemical Reactions In Aqueous Solutions, Osman Uner

Graduate Theses and Dissertations

The energy barriers for SN2 ligand exchange reactions between the chloride anion and para-substituted benzyl chlorides were investigated both in water solution and in the gas phase by using quantum chemical simulations at the DFT and Hartree-Fock levels. The question addressed was the effect of the solvent (water) and of the substituent on the barrier height. The para substitutient groups included NH2, OH, OCH3, CH3, C(CH3)3, H, F, Cl, Br, I, CF3, CN, NO2, and SO3- . The calculations in aqueous solution were carried out with the recently developed Ultrafast Monte Carlo method using the TIP3P explicit water model. The …

Synthesis Of Platinum And Platinum-Copper Branched Nanoparticles For Electrooxidation Of Methanol, Eric Courtland Taylor

Graduate Theses and Dissertations

Platinum and Pt alloys are among the most important heterogeneous catalysts for many organic reactions and electrochemical reactions associated with the fuel cell technologies. How to reduce Pt usage while maintaining the performance of the catalysts becomes a subject for intensive research in materials chemistry. For heterogeneous catalysis, the catalytic reactivity and selectivity are strongly correlated with different crystallographic facets exposed on the surface. The facets with high-index planes whose Miller indices with at one is larger than unity are generally more active than those with low-index planes (e.g., {100}, {111}, and {110}). Tuning the morphology of the nanoparticles to …

Structure-Function Relationship Of The Ligand-Binding Domain Of The Fibroblast Growth Factor Receptor, Ryan Thurman

Graduate Theses and Dissertations

The interactions between FGF and fibroblast growth factor receptors are responsible for the regulation of key cellular processes. FGF is important in both germ cell and embryonic developments. FGF continues to play important roles during adulthood by regulating embryogenesis, cell differentiation, and wound healing (1-7). The regulations of these cellular events are initiated through FGF binding to the fibroblast growth factor receptors. The complex formed by FGF and the receptor involves a key interaction with heparin. Through interactions with heparin, the FGF, FGFR and Heparin form a 2:2:2 complex (8). This complex formation results in autophosphorylation in the tyrosine kinase …

Multiscale Study Of Batio3 Nanostructures And Nanocomposites, Lydie Louis Louis

Graduate Theses and Dissertations

Advancements in integrated nanoelectronics will continue to require the use of unique materials or systems of materials with diverse functionalities in increasingly confined spaces.

Hence, research on finite-dimensional systems strive to unearth and expand the knowledge of fundamental physical properties in certain key materials which exhibit numerous concurrent and exploitable functions.

Correspondingly, ferroelectric nanostructures, which particularly display a plethora of complex phenomena, prevalent in countless fields of research, are noteworthy candidates. Presently, however, the assimilation of zero-(0D) and one-dimensional (1D) ferroelectric into micro- or nano-electronics has been lagging, in part due to a lack of applied and fundamental studies but …

The Confounding Effects Of Ability, Item Difficulty, And Content Balance Within Multiple Dimensions On The Estimation Of Unidimensional Thetas, Ki Lynn Matlock

Graduate Theses and Dissertations

When test forms that have equal total test difficulty and number of items vary in difficulty and length within sub-content areas, an examinee's estimated score may vary across equivalent forms, depending on how well his or her true ability in each sub-content area aligns with the difficulty of items and number of items within these areas. Estimating ability using unidimensional methods for multidimensional data has been studied for decades, focusing primarily on subgroups of the population based on the estimated ability for a single set of data (Ackerman, 1987a, 1989; Ansley & Forsyth, 1985; Kroopnick, 2010; Reckase, Ackerman, & Spray, …

Algae To Propellants: Biosynthesis Of 1,2-Propanediol From Algal Derived Sugars, Lauren Rachelle Merriman

Graduate Theses and Dissertations

Propylene glycol dinitrate (PGDN) is an important component used in the formulation of energetic materials. A renewable, environmentally-friendly and effective production technique for the production of 1,2-propanediol, an important precursor to PGDN, is desired. While fermentation of 1,2-propanediol has been achieved, it suffers from major limitations such as expensive feed sugars and relatively low yields. It is hypothesized that algae sugars could serve as a feedstock for the microbial synthesis of 1,2-propanediol, thereby reducing production costs and enhancing sustainability.

Algal biomass produced from an Algal Turf Scrubber® has proven to have significant potential as a source of fermentable materials. However, …

Optimization Of Sample Preparation In Matrix-Assisted Laser Desorption/Ionization (Maldi) Mass Spectrometry Of Macromolecules, Evgenia Akhmetova

Graduate Theses and Dissertations

New method for the matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) and Fourier transform mass spectrometry (MALDI-FTMS) analysis of low molecular weight polyvinyl acetate (PVAc) was developed and then applied to the characterization of commercially available chewing gum. The optimization of MALDI analysis of PVAc was achieved by investigating the influence of sample preparation variables such as the choice of solvent and choice of matrix-analyte ratio. It was demonstrated that the use of ethyl acetate as a solvent and 2,5-Dihydroxybenzoic acid as a matrix yielded the highest signal intensity for the pure polymer sample. The application of TOF technique did not …

Biodiesel Transesterification Byproducts As Soil Amendments, Solomon Parker

Graduate Theses and Dissertations

For every ten kilograms of biodiesel that is produced from the transesterification of vegetable oil, approximately 1 kg of glycerol is produced as a byproduct. Also known as glycerin, it is a chemical used in many products including cosmetics, foods, and desiccants. However, the crude glycerol created during biodiesel production is tainted with potassium hydroxide and methanol making it unsuitable for commercial use without costly refinement. With increase in production of biodiesel driven by rising fuel prices, the market has become glutted with glycerol and it is on the threshold of becoming a waste product. Common methods for disposing glycerol …

Creep, Fatigue And Creep-Fatigue Interactions In Modified 9% Cr - 1% Mo (P91) Steels, Valliappa Kalyanasundaram

Graduate Theses and Dissertations

Grade P91 steel, from the class of advanced high-chrome ferritic steels, is one of the preferred materials for many elevated temperature structural components. Creep-fatigue (C-F) interactions, along with oxidation, can accelerate the kinetics of damage accumulation and consequently reduce such components' life. Hence, reliable C-F test data is required for meticulous consideration of C-F interactions and oxidation, which in turn is vital for sound design practices. It is also imperative to develop analytical constitutive models that can simulate and predict material response under various long-term in-service conditions using experimental data from short-term laboratory experiments. Consequently, the major objectives of the …

Active Galactic Nuclei Mergers And Outflows: Observations From Optical And Ultraviolet Emission Lines, Robert Scott Barrows

Graduate Theses and Dissertations

I have investigated the nature of a subset of active galactic nuclei (AGN) which show double peaks in their characteristic optical and ultraviolet emission lines. I have performed this investigation through studies of the broad emission line regions (BLRs), which are produced less than 1 pc from the central supermassive black hole (SMBH), and the narrow emission line regions (NLRs), which originate at larger (kpc) distances. The BLR studies consist of detailed line modeling of two individual quasars with double-peaked broad emission line profiles. The modeling suggests there are two primary interpretations of the complex broad line profiles. The first …

Oxidation Of Thrombomodulin Methionine 388 In Cigarette Smokers, Samrat B. Thapa

Graduate Theses and Dissertations

This work tested the hypothesis that oxidation of methionine 388 in thrombomodulin is higher in cigarette smokers, and thus a likely contributor towards the hypercoagulable state in smokers. Thrombomodulin, a protein cofactor found on endothelial cell surfaces, regulates the activity of thrombin. Thrombin bound to thrombomodulin no longer converts fibrinogen to fibrin, but instead activates Protein C which, in turn, stops the coagulation cascade by inactivation of clotting factors. The oxidation of methionine 388 of thrombomodulin has been shown in vitro to dramatically decrease the anticoagulant cofactor activity of thrombomodulin. The blood of cigarette smokers is more prone to clot …

Hardy Space Properties Of The Cauchy Kernel Function For A Strictly Convex Planar Domain, Belen Espinosa Lucio

Graduate Theses and Dissertations

This work is based on a paper by Edgar Lee Stout, where it is shown that for every strictly pseudoconvex domain $D$ of class $C^2$ in $\mathbb{C}^N$, the Henkin-Ram\'irez Kernel Function belongs to the Smirnov class, $E^q(D)$, for every $q\in(0,N)$.

The main objective of this dissertation is to show an analogous result for the Cauchy Kernel Function and for any strictly convex bounded domain in the complex plane. Namely, we show that for any strictly convex bounded $D\subset\mathbb{C}$ of class $C^2$ if we fix $\zeta$ in the boundary of $D$ and consider the Cauchy Kernel Function

\mathcal{K}(\zeta,z)=\frac{1}{2\pi i}\frac{1}{\zeta-z}

as a …

Interactions Between Ions And Lysenin Nanochannels And Their Potential Applications As Biosensors, Radwan Awwad Al Faouri

Graduate Theses and Dissertations

Lysenin is classified as a pore-forming toxin protein that is isolated from the earthworm Eisenia fetida and consists of 297 amino acids [1]. Lysenin inserts large conducting pores (3.0-4.7 nm in diameter) into artificial membranes (BLM) which include sphingomyelin. These pores (channels) are open and oriented upon insertion into the bilayer lipid membrane. Lysenin channels gate at positive voltages (voltage-induced gating), but not at negative voltages. Lysenin pores also exhibit activity modulation in response to changes in ionic strength and pH, indicating that electrostatic interaction is responsible for Lysenin conductance activities. In this line of inquiries, and by modulating Lysenin …

Improvements In Microdialysis Sampling Extraction Efficiency Using Recycled Flow, Justin Cole Deaton

Graduate Theses and Dissertations

Incomplete recovery during microdialysis sampling is hindering important research in neurology, proteomics, and immunology. Although the current generalized solution, decreasing volumetric flow rates (Q), has been and will remain to be a useful strategy it has reached it's a physical limitation due to evaporation at the collection site. Consequently, many important signaling molecules, such as signaling proteins, remain difficult to study. It is more fundamental to consider relative recovery as a function of the interaction time between the perfusate and the environment surrounding the probe.

In this work an increase in relative recovery was predicted by a mathematical model. Using …

Quantum Resonant Beats And Revivals In The Morse Oscillators And Rotors, Zhenhua Li

Graduate Theses and Dissertations

Analytical eigenfunctions and eigenvalues for the Morse oscillator were applied to investigate the quantum resonant beats and revivals of wave packet propagation. A concise way for exact prediction of the complete revival period of the Morse oscillator was given for the first time. It was suggested that any complete period was made of integer numbers of the minimum or fundamental period. Within the fundamental period, the anharmonicity of this oscillator appeared to cause interesting space-time phenomena that include relatively simple Farey-sum revival structures. In addition, a simple sum of two Morse oscillators led to a double-Morse well whose geometric symmetry …

Effects Of Ergot Alkaloids And Bovine Bodily Fluids On Cytochrome P450 Activity, Nicholas Scott Ezell

Graduate Theses and Dissertations

This thesis evaluates the Promega^TM P450-Glo assay (Promega^TM V9800) as a tool for quantifying ergot alkaloid concentration. Current techniques used for detection of ergot alkaloids are slow and expensive, do not detect all ergot alkaloids, or are not effective on bovine bodily fluids. The first study was conducted to determine effects of commercial ergot alkaloids (n = 6; 0 - 400 μM) on the Promega^TM P450-Glo assay. Cytochrome P450 (CYP450) activity in assay had a differential response to each ergot alkaloid and concentration. As concentrations of ergotamine, dihydroergotamine, ergocornine, and ergocryptine increased CYP450 activity was inhibited (P …