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Full-Text Articles in Engineering
Co-Occurrence Of Microplastics, Uranium And Arsenic In Heavy Metal-Contaminated Freshwaters And Their Potential Interaction, Jasmine Anne Quiambao
Co-Occurrence Of Microplastics, Uranium And Arsenic In Heavy Metal-Contaminated Freshwaters And Their Potential Interaction, Jasmine Anne Quiambao
Civil Engineering ETDs
This study identified microplastics and heavy metals in fields sites of freshwater systems in New Mexico and evaluated the interactions of arsenic (As) and uranium (U) with commercial microplastics for acidic and neutral pH in laboratory-controlled conditions. The potential interaction of microplastics with other contaminants is not well-established. Microplastics could interact with heavy metals in ecosystems with naturally elevated background concentrations of metals or affected by anthropogenic activities. Previous studies have found heavy metal contamination in freshwater systems in New Mexico near abandoned mine sites. The objective of this study is (1) to identify and characterize microplastics from metal contaminated …
Ultrafast Spectroscopy Of Air Lasing In Filaments, Brian Robert Kamer
Ultrafast Spectroscopy Of Air Lasing In Filaments, Brian Robert Kamer
Optical Science and Engineering ETDs
Filamentation in air is a phenomenon that has been extensively investigated for the last two decades. At sufficiently high intensity, even air is a nonlinear medium. These intensities are reached with ultrashort pulses (50 to 100 fs) of more than 1 J energy, which self-focus in air, reach ionizing intensities of oxygen and nitrogen, creating a plasma that defocuses the beam. The air filament is a self-induced waveguide resulting from a balance of focusing and defocusing. In this work new techniques were developed to visualize and analyze this phenomenon through its emission, in particu- lar the UV emission of the …
The Profound Photophysical Effects Of Organic Chromophore Connectivity And Coupling, David J. Walwark Jr
The Profound Photophysical Effects Of Organic Chromophore Connectivity And Coupling, David J. Walwark Jr
Nanoscience and Microsystems ETDs
Through-bond and through-space interactions between chromophores are shown to have wide-ranging effects on photophysical outcomes upon light absorption in organic molecules. In collapsed poly(3-hexylthiophene), through-space coupling creates hybrid chromophores that act as energy sinks for nearby excitons and favorable sites for molecular oxygen to dock. Upon excitation with visible light the highly-coupled chromophores react with the docked oxygen and subsequently do not quench nearby excitons as efficiently. In tetramer arrays of perylene diimide chromophores the central moiety through-bond connectivity is synthesized in two variants which exhibit vastly different single-molecule blinking behavior and theoretically-predicted electronic transition character. In the more-connected tetramer …
Organic/Inorganic Interfacial Interactions Affecting Metal Reactivity: Water Treatment And Sensor Applications, Mohamed Nabil Shaikh
Organic/Inorganic Interfacial Interactions Affecting Metal Reactivity: Water Treatment And Sensor Applications, Mohamed Nabil Shaikh
Civil Engineering ETDs
The aim of this dissertation was to investigate the interactions occurring at the organic – inorganic interface between solid media and aqueous contaminants for water treatment and sensor applications. The gaps in current literature on these interfacial organic-inorganic interactions must be bridged in order to develop advanced water treatment and monitoring technologies for improving water quality and thus, restore and protect the contaminated water resources. As a part of this dissertation, manganese oxides-based composites and electrospun polymer mats were developed and investigated for gaining mechanistic insights of organic (bisphenol A and acetaminophen) and inorganic (uranium) contaminants removal, respectively. These reactions …