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Filtering by: Creator Fredricks, Gregory Alan Remove constraint Creator: Fredricks, Gregory Alan Degree Name Doctor of Philosophy (Ph.D.) Remove constraint Degree Name: Doctor of Philosophy (Ph.D.) License All rights reserved Remove constraint License: All rights reserved

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  • Hydrogen isotopic composition of C₃₇ alkenones and the ecology and physiology of coccolithophores

    Creator:
    Wolhowe, Matthew D.
    Abstract:
    A three-part study was conducted into the impact of physiological and ecological variables on the net isotopic fractionation of hydrogen, α[subscript K₃₇], expressed in C₃₇ alkenones. First, alkenone-producer production, abundance, and export were characterized in the summertime Gulf of California and Eastern Tropical North Pacific using compound-specific, labeled in situ...
    Resource Type:
    Dissertation
    Full Text:
    Fredrick G. Prahl A three-part study was conducted into the impact of physiological and ecological

  • Development of Cu-based Thin Films for Optoelectronic Applications

    Creator:
    Angelos, Gregory S.
    Abstract:
    CIGS and CdTe based commercial thin-film solar cells (TFSCs) require an absorber thickness greater than 2 µm and 4 µm, respectively, to adequately absorb the solar spectrum. To efficiently extract photoexcited electrons, these TFSCs require relatively defect-free absorbers with high-minority carrier mobility (> 100 cm2V−1s−1) and long lifetime (> 10...
    Resource Type:
    Dissertation
    Full Text:
    AN ABSTRACT OF THE THESIS OF Gregory S. Angelos for the

  • Optical Sensors using Biological Photonic Crystals

    Creator:
    Squire, Kenneth James
    Abstract:
    This dissertation focuses on the application of diatom frustules, the biosilica shell of an algae possessing physical and photonic properties capable of enhancing optical signals, for the enhancement of optical sensing. In this work, we incorporate diatom frustules into biosensors for signal enhancement and improved target molecule detection. The potential...
    Resource Type:
    Dissertation
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    biosilica Kenneth Squire, Xianming Kong, Paul LeDuff, Gregory L. Rorrer, and Alan X. Wang

  • Nutrient Addition Strategies for the Marine Diatom Cyclotella sp to Control Cell, Lipid, and Chitin Formation.

    Creator:
    Chiriboga Novillo, Omar Guillermo
    Abstract:
    Marine diatoms are unicellular photosynthetic organisms that produce unique nanomaterials, energy dense lipid-molecules, and specialty carbohydrate molecules that can be all extracted from a single microorganism. The centric marine diatom Cyclotella sp. was used as a model organism for cultivation in a biorefinery system, where multiple co-products can be harvested...
    Resource Type:
    Dissertation
    Full Text:
    Gregory L. Rorrer Marine diatoms are unicellular photosynthetic organisms that produce unique

  • Functional materials for advanced energy and electronic devices

    Creator:
    Flynn, Brendan T.
    Abstract:
    Advances in energy technologies and electronics have typically occurred through either heightened performance or cost reduction. This dissertation explores both routes through a series of fundamental material studies that may contribute to the enabling of next generation devices. Solution based syntheses and deposition of chemical products offer a low cost...
    Resource Type:
    Dissertation
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    Devices. Abstract approved: ______________________________________________________ Gregory S

  • Biological insertion of nanostructured germanium and titanium oxides into diatom biosilica

    Creator:
    Jeffryes, Clayton S.
    Abstract:
    There is significant interest in titanium oxide and germanium-silicon oxide nanocomposites for optoelectronic, photocatalytic, and solar cell applications. The ability of the marine diatom Pinnularia sp. to uptake soluble metal oxides from cell culture medium, and incorporate them into the micro- and nano-structure of their amorphous silica cell walls, called...
    Resource Type:
    Dissertation
    Full Text:
    Gregory L. Rorrer There is significant interest in titanium oxide and germanium-silicon oxide

  • Solution-based nanomaterials and thin films for next generation electronics

    Creator:
    Oleksak, Richard P.
    Abstract:
    Nanomaterials are expected to enable significant advances in several technological fields in coming years. Among them, electronics has emerged as one of the most likely benefactors from the ability to control matter on the nanometer-scale. For many electronic devices synthesized nanomaterials must be integrated into thin film structures. Vapor-based deposition...
    Resource Type:
    Dissertation
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    : ______________________________________________________ Gregory S. Herman Nanomaterials are expected to enable significant advances in

  • Investigating Latent State and Uncertainty Representations in Reinforcement Learning

    Creator:
    Koul, Anurag
    Abstract:
    Learning latent space representations of high-dimensional world states has been at the core of recent rapid growth in reinforcement learning(RL). At the same time, RL algo- rithms have suffered from ignored uncertainties in the predicted estimates of model-free or model-based methods. In our work, we investigate both of these aspects...
    Resource Type:
    Dissertation
    Full Text:
    approved: Alan Fern Learning latent space representations of high-dimensional world states has been at

  • Chronobiology of garter snakes : environmental and hormonal mechanisms mediating hibernation and reproduction

    Creator:
    Lutterschmidt, Deborah I.
    Abstract:
    Most vertebrates exhibit seasonality in many life history traits. Such seasonal rhythms are temporally organized via the transduction of environmental cues (e.g., photoperiod, temperature) into appropriate endocrine signals. However, among ectothermic vertebrates that undergo continuous winter dormancy, temperature is the only environmental cue available for synchronizing seasonal rhythms. Most intriguing...
    Resource Type:
    Dissertation
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    designs. In addition, I would like to thank my committee members – Frank L. Moore, Fredrick Stormshak

  • (Opto)electronic Properties of Xylindein and Organic (Opto)electronic Devices

    Creator:
    Giesbers, Gregory J.
    Abstract:
    Organic semiconductors are of interest for (opto)electronic applications due to their low cost, solution processability, and tunable properties. Natural product-derived organic pigments have attracted attention due to their extraordinary environmental stability and unexpectedly good optoelectronic performance, in spite of only partially conjugated molecular structures. Fungi-derived pigments are a naturally sourced,...
    Resource Type:
    Dissertation
    Full Text:
    ABSTRACT OF THE DISSERTATION OF Gregory J. Giesbers for the degree of Doctor of Philosophy in Physics