Physical Sciences and Mathematics Commons^™

Simultaneous Multi-Angle Measurements Of Plasma Turblence At Haarp, Naomi Watanabe

Master's Theses and Doctoral Dissertations

We report the results from a recent series of experiments employing the HAARP HF transmitter to generate and study strong Langmuir turbulence (SLT) in the interaction region of overdense ionospheric plasma. Diagnostics included the Modular UHF Ionospheric Radar (MUIR) sited at HAARP, the Super DARN-Kodiak HF radar, and HF receivers to record stimulated electromagnetic emissions (SEE). Short pulse, low duty cycle experiments demonstrate control and suppression of artificial field-aligned irregularities (AFAI). This allows the isolation of ponderomotive plasma turbulence effects. For the first time, plasma line spectra measured simultaneously in different spots of the interaction region displayed marked but contemporaneous …

Synthesis And 1H-Nmr Characterization Of Amphiphilic Acrylate Block Copolymers To Investigate The Effect Of Chain Rigidity On Micelle Formation In Solution, David Arnold

Master's Theses and Doctoral Dissertations

Amphiphilic block copolymers are composed of distinct segments exhibiting different chemical properties. In solution, block copolymers may self-assemble to form micelles when triggered by a change in the environment. The effect of chain rigidity can be investigated in better detail if the molecular weights are controlled, as the polymer’s ability to aggregate is also influenced by polymer size. Acrylate and methacrylate monomers were chosen for their similar chemical properties but their difference in reported glass transition temperature (T_g) ¹H-NMR methods were developed to measure molecular weight of poly(methyl methacrylate) and poly(t-butyl acrylate) homopolymers to corroborate size-exclusion …

Synthesis, Characterization, And Evaluation Of A Heat Stabilizing Siloxane, Joel D. Kennard

Master's Theses and Doctoral Dissertations

Siloxanes, renowned for their heat resistance and release properties, are prone to oxidize above 200°C. The goal herein is to increase siloxane bath life used in fuser roll applications at temperatures above 200°C, yielding faster production, less waste, and cost savings by keeping the bath viscosity stable through prevention of thermal degradation.

The methods detailed herein react a hydrosiloxane with an amino functional alcohol (4-(phenylamino)-phenol). The alcoholysis (or dehydrogenative coupling) moves forward with the removal of hydrogen and formation of the desired product (Scheme 1). Reactions were conducted on both NMR scale and lab scale.

The results of the synthesis …

Chemiluminescent Reactions Catalyzed By Nanoparticles Of Gold, Silver, And Gold/Silver Alloys, Saqib Ul Abideen

Master's Theses and Doctoral Dissertations

Chemiluminescence (CL) reactions are catalyzed by metals nanoparticles, which display unique catalytic properties due to an increased surface area. The present study describes the catalytic effects of nanoparticles (NP) of silver, gold, and alloys of Au/Ag nanoparticles on the chemiluminescent reaction taking place between luminol and potassium ferricyanide. It was found that silver nanoparticles and alloy nanoparticles enhance the CL process when their sizes remained in the range of 30 nm to 50 nm. The data show that the intensity and rate of chemiluminescence were influenced by the mole fraction of gold and silver in the alloy. Data to this …

Characterization Of Mirco/Nano Mechanical And Tribological Properties Of Polymeric Coatings Deposited On Steel, Dustin Neill

Master's Theses and Doctoral Dissertations

This study aims to characterize the mechanical and tribological properties of three different polymeric coatings—polyurethane, 2K, and melamine—deposited on steel by analyzing the hardness, elastic modulus, and scratch resistance of each coating. This was accomplished by making indentation and scratch tests on each sample with a nano-indenter and analyzing the results with a Scanning Probe Microscope (SPM). Results of indentation tests show that melamine, with a hardness of 0.164 GPa and a modulus of 3.367 GPa, was both the hardest and stiffest of the three coatings, while the 2K coating, with a hardness of .104 GPa and a modulus of …

Development Techniques For Android Platform Mobile Device Application, Ivan Njunjic

Master's Theses and Doctoral Dissertations

This thesis focuses on Android application development techniques needed to implement a mobile application portal that consists of features used at Eastern Michigan University. Since there is not a single source available to developers that explains such techniques, this thesis represents a unique manual for such development. Based on the similarity of features, mainly in terms of data nature and access, five techniques are defined in a step-by-step procedural manner. This is accomplished by outlining the development techniques and presenting them “in action” with coding examples from a fully developed demo application. As a result, the demo application demonstrates functional …

The Synthesis Of Amphiphilic Diblock Copolymers: An Investigation Into The Formation Of Micelles As A Function Of Hydrophobic Block Length, Kevin S. Kawchak

Master's Theses and Doctoral Dissertations

Acrylate-based amphiphilic diblock copolymers show great potential for anti-cancer drug transport due to their ability to aggregate into protective core-shell micelles. Using RAFT polymerization, copolymers containing poly(acrylic acid) and poly(methyl acrylate) blocks were made with high monomer conversion and narrow distributions of molecular weight for eventual use in medicinal applications. Based on previous findings of copolymers with low weight hydrophobic blocks failing to micellize, it was hypothesized that increasing the poly(methyl acrylate) block length would allow for micelle formation. 1H-NMR experiments conducted in the presence of an aqueous solution yielded diminished and broadened resonances of the lengthened hydrophobic block, which …

Synthesis And Purification Of Potential Antimicrobial Peptides, Christopher Ryan Snyder

Master's Theses and Doctoral Dissertations

No abstract provided.

Progress Towards Heterocycles As Inhibitors Of Plasminogen Activator Inhibitor-1, Gregory Alan Abernathy

Master's Theses and Doctoral Dissertations

No abstract provided.

Image Reconstruction Through Polyfiltered Variation Minimization, Michael Hagen

Master's Theses and Doctoral Dissertations

There has been considerable interest in reconstruction of remotely sensed imagery from incomplete frequency measurements for some time now. Given the nature of the collection process, it may be that portions of the spectrum are either missing or corrupted such that one is left with an incomplete representation of the original image. The advances in both the theory and available software for sparse signal reconstruction through function minimization make it an attractive approach for recreating the missing frequency data. It is the aim of this thesis to generalize the reconstruction technique known as Total Variation (TV) minimization from a signal …

Experimental Simulation Of Human Islet Amyloid Polypeptide (Hiapp)-Pancreatic Beta Cell Membrane Interactions: Inferences And Implications In The Etiopathogenesis Of Diabetes Mellitus Type Ii, Sarika Pamarthy

Master's Theses and Doctoral Dissertations

Pancreatic beta cells secrete insulin, an endocrine hormone that regulates blood glucose levels and maintains normal physiological activity in humans and animals. Diabetes mellitus type II is a consequence of the gradual destruction of these important cells, likely by human islet amyloid polypeptide (hIAPP) that is co-secreted with insulin. Increasing health care costs, coupled with the World Health Organization’s prediction of a worldwide diabetic epidemic by year 2030, make experimental diabetes research a crucial prologue to future clinical trials in prevention, diagnosis, and treatment of Diabetes mellitus type II. Our experimental set-up simulates hIAPP peptide fragment and pancreatic beta cell …