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Nonlinear Optical Studies Of Defects And Domain Structures In Perovskite-Type Dielectric Ceramics, David J. Ascienzo

Dissertations, Theses, and Capstone Projects

In order to improve future generations of dielectric capacitors a deeper understanding of voltage-induced dielectric breakdown and electrical energy storage limitations is required. This dissertation presents the use of far-field optical second harmonic generation (SHG) polarimetry for probing structural defects and polar domains in linear and nonlinear perovskite dielectric ceramics. We investigated the formation of electric field-induced structural distortions at pristine Fe-doped SrTiO₃ (Fe:STO) electrode interfaces, structural defect and strain formation due to oxygen vacancy migration in electrodegraded Fe:STO single crystals, and mixed tetragonal and rhombohedral phase domains in ferroelectric Zr-doped BaTiO₃ (BZT) films exhibiting excellent …

Removal Of Organic Micro-Pollutants From Water Using Sewage Sludge Based Composite Adsorbents, Rui Ding

Dissertations, Theses, and Capstone Projects

Millions of tons of sewage sludge, waste oil sludge and fish waste are produced annually, and improper treatment/disposal of these wastes have resulted in numerous environmental issues. On the other hand, these wastes are rich in organic materials, metals, and inorganic minerals and could be sustainable resources if utilized properly. The main purpose of this dissertation study was, therefore, to convert these wastes into composite adsorbents, and then use these adsorbents to remove various types of organic pollutants, emerging organic contaminants in particular, from wastewater and drinking water sources.

It is hypothesized that a hydrophobic carbon phase in the composite …