Physical Sciences and Mathematics Commons^™

Shedding Light On The Coupling Dynamics In Hybrid Nanostructures, Saba Arash

Theses and Dissertations

Here we present all-optical investigations of two hybrid nanostructures. In the first hybrid system, we study Janus-type nanofibers consisting of two hemi-cylinders of ferroelectric barium titanate and ferrimagnetic cobalt ferrite. Using the magnetic field-dependent polarization-resolved second harmonic generation technique, we observe a strong magnetoelectric coupling between the two ferroic constituents at room temperature. Corroborating these results by X-ray diffraction, we can also extract repeatable memory-dependent behaviors in these biphasic nanofibers. In the second hybrid system, we study the interaction between the semiconductor indium/gallium arsenide quantum dots and surface plasmon supporting silver structures in the weak coupling regime. When quantum dots …

Synchrotron X-Ray Characterizations Of Black Phosphorus: Preparation, Doping And Applications In Energy Storage, Minsi Li

Electronic Thesis and Dissertation Repository

Black phosphorus (BP), as a two-dimensional material, has attracted interest in recent decades due to its unique properties—tunable band gap and high carrier mobility. Specifically, BP shows ultra-high theoretical capacity of 2595 mA h g^-1, resulting in high potential practical applications in lithium-ion batteries (LIBs). However, several challenges limit the development of BP in the energy storage field and LIBs: 1) The cost of the current synthesis methods of BP is too high to support extensive research studies and practical applications; 2) The electrical conductivity of BP is insufficient in LIBs; 3) The huge volume change of BP …

Investigation Of Shocked Basalts From Vargeão Dome And Vista Alegre: Implications For The Search For Life On Mars, Nikol Posnov

Electronic Thesis and Dissertation Repository

Impact craters represent excellent astrobiological targets for planetary exploration missions to Mars. The impact of an asteroid or comet into a crystalline, H₂O-bearing target may result in development of a hydrothermal system and increase the habitability of the substrate for the colonization of endolithic microorganisms. Given that Mars’ surface is covered by cratered basaltic rock, this study investigated target rocks and impact breccias from Vargeão Dome and Vista Alegre impact structures that formed in basalt in the Paraná Basin of Brazil.

Utilizing petrography and micro-X-ray diffraction (μXRD), the degree of shock metamorphism in plagioclase was quantitively determined. Measuring …

Characterization And Hydrogenation Activity Of Supported Palladium Particles, Narayan Acharya

Theses and Dissertations

In this project, the hydrogenation activity of palladium (Pd) particles supported on different carbon and oxide supports was investigated. Supported Pd particles were prepared using strong electrostatic adsorption (SEA) technique, which is known to produce metal particles with narrow and uniform distribution. The scanning transmission electron microscopy (STEM), X-ray diffraction (XRD), and chemisorption methods were used to characterize the Pd particle size in this project. The Pd particles on different supports were annealed at a specific temperature, and the particle size was studied as a function of annealing temperature. Propylene hydrogenation to propane was conducted in a flow reactor to …

Telsam-Target Protein Fusions Can Form Diffraction-Quality Crystals Without Direct Inter-Polymer Contacts, Moriah Longhurst

Undergraduate Honors Theses

X-ray diffraction is a robust method for determining the detailed 3D structures of specific proteins. However, this requires the formation of well-ordered protein crystals, a process that is time-consuming, expensive, and only has about a 10-30% success rate. New methods are needed to enable the efficient crystallization of challenging proteins. One such technique is explored here, which utilizes a protein polymer (the sterile alpha motif domain of the human protein translocation Ets leukemia, or TELSAM) as a crystallization chaperone to form a more ordered crystal lattice of target proteins and drive crystallization. This method was successfully used to crystallize, collect …

Novel Vic-Dioximes: Synthesis, Structure Characterization, And Antimicrobial Activity Evaluation, Dumitru Ureche, Ion Bulhac, Alexandru Ciocarlan, Daniel Roshca, Lucian Lupascu, Paulina Bourosh

Turkish Journal of Chemistry

The vic-dioximes are compounds with various industrial uses and scientific applications. Many coordination compounds have been synthesized based on vic-dioximes. This study presents the synthesis and full characterization of two vic-dioximes based on dichloroglyoxime, p-aminobenzoic acid, and p-aminotoluene. Their structures were proved by IR, 1H, 13C and 15N NMR spectral analysis, and single crystal X-ray diffraction. One of the reported vic-dioximes, bis(di-p-aminotoluene)glyoxime mono-p-aminotoluene trihydrate showed good to moderate antimicrobial activity against both nonpathogenic gram-positive and gram-negative bacteria (Bacillus subtilis and Pseudomonas fluorescens), phytopathogenic (Xanthomonas campestris, Erwinia amylovora, E. carotovora) and the fungi (Candida utilis and Saccharomyces cerevisiae) at MIC - …