Characterization of uranium isotope compositions is of great interest in many nuclear sub-areas for safeguards purposes. Reprocessing facilities utilizing pyroprocessing raised an issue of uranium isotope monitoring due to the difficulty to apply traditional approaches under extreme environments. An rapid and remote method to characterize uranium isotope compositions for such...
The general theme of this dissertation is the development of new analytical sensors to quantitatively study biological and environmental samples in aqueous and non-aqueous environments. A platinum ultramicroelectrode (UME) and a unique carbon-based pH microprobe were used to design a new SECM-based electrochemical bioassay. The Pt UME was used to...
Understanding the impact of inter-molecular orientation on the optical proper-ties of organic semiconductors is important for designing next-generation organic (opto)electronic and photonic devices. However, fundamental aspects of how various features of molecular packing in crystalline systems determine the nature and dynamics of excitons have been a subject of debate. Toward...
This dissertation covers my work relating to the application of strong terahertz (THz) radiation to study the nonlinear properties of nano-scale material. It presents experimental and numerical studies on the optical and electronic properties of various material system including single-layer graphene, multi-walled carbon nanotubes (MWCNTs), nanoantenna-patterned gallium arsenide (GaAs) and...
Time-dependent crack growth mechanisms in Alloy 617 at 800°C in air were studied using compact tension samples machined in the L-T direction, cracked at temperature using an induction furnace and servo-hydraulic load frame. The application of different loading waveforms, including triangular, hold time, and sustained loading, were studied with relation...
Metal organic Frameworks (MOFs) that experience stimuli induced structural transformation could enable a whole new class of materials with remarkable properties. Photoactuating moieties in the structure could effect changes in the pore space or macroscale shape change enabling light driven gas separation and actuators. Here, we present a novel approach...
The spatial distribution and geologic histories of submarine volcanoes provide insight into submarine eruptive behavior, deep earth processes and plate tectonics. This dissertation examines the evolution of individual submarine volcanic edifices as well as linear trails of seamounts at three spatial and temporal scales.
In order to understand constructive and...
In this dissertation, a series of studies in the field of terahertz (THz) science are presented, specifically using nonlinear THz spectroscopy. We exploit huge field enhancement and subwavelength confinement in plasmonic structures. There are three distinct projects which will be discussed: nonlinear THz spectroscopy using plasmonic induced transparency (PIT), THz-triggered...
This dissertation reports on the computational physics research in the area of
inhomogeneous fluids. I first discuss the theory background for this work beginning
with water, which is important for the two published articles that are presented in
this work (Chapters 5 and 6). Next, I give a brief overview...
Weak-wind flow in the nocturnal boundary is one of the most poorly understood problems in the field of meteorology. The understanding of weak-wind flows is essential for the improvement of regulatory dispersion models which are currently rendered invalid under weak-wind conditions and stable stratification. Recently there have been increased efforts...