Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 62 for “"full width at half maximum"”.
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An optical study of lithium and lithium-oxygen complexes as donor impurities in single crystal silicon
… the sake of clarity, the results of this investigation are presented in two parts; first we discuss the lithium donor in silicon, and later the lithium-oxygen interaction in silicon. We present here a discussion of information which is common to both aspects of the problem. The data is presented …
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A space focused ion time of flight mass spectrometer, and spectroscopy of hydrogen chloride, deuterium chloride, and hydrogen sulfide at "hard" x-ray energies
… mass spectrometer was used to study the relaxation dynamics of HCl, DCl, and H{dollar}\sb2{dollar}S following the excitation of a K-shell electron using synchrotron radiation. On resonance, fragmentation of the molecule involving neutral dissociation of hydrogen was found to be a significant …
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The Growth and Characterization of GaN Thin Films on SiC Substrates
Optical devices based on III-V nitrides operating in the visible region involve GaN based materials. The development of such devices first requires the optimization of GaN crystal quality. This thesis addresses issues related to substrate cleaning and growth of high quality GaN on C-terminated …
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Single proton transfer on 55Mn
… and ⁵⁵Mn(d,d)⁵⁵Mn(g.s.) reactions at Ed = 45.6 MeV were measured in the 6°-48° angular region (laboratory frame) using a k = 600 MeV magnetic spectrometer with a resolution of ~40 keV (full-width at half maximum). Spectroscopic factors associated with the observed transitions to …
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Haze measurements through image analysis
… fires in Indonesia. Currently, haze concentration is measured by filtering air samples at various stations in Singapore. In this thesis, optical approaches to haze measurements are explored. Images of haze were taken in fifteen minute intervals in June, 2013. These images were analyzed to …
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Efficient light emitting devices utilizing CdSe(ZnS) quantum dots in organic host matrices
We demonstrate efficient electroluminescence from thin film structures containing core-shell CdSe(ZnS) quantum dots dispersed in molecular organic host materials. In the most efficient devices, excitons are created on the quantum dot sites via energy transfer from organic host molecules, and direct …
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Design and evaluation of a laser ion source for TITAN to measure 222Rn daughter product abundances
… and implementing a Laser Ion Source (LIS) at TRIUMF’s Ion Trap for Atomic and Nuclear Science (TITAN) facility to achieve high-precision isotope abundance ratio mea-surements across diverse materials. The project aims to quantify long-lived daughter products of 222Rn, including 210Pb, …
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Fluctuation Electron Microscopy Investigations of Medium Range Order in a-Silicon and a-Silicon:hydrogen Thin Films
… practical version of variable resolution fluctuation electron microscopy has been developed on the JEOL 2010F transmission electron microscope in the Center for Microanalysis of Materials, UIUC. This technique provides information on the spatial extent of the medium range order. Nanodiffraction …
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Controlling structure and composition in double-heterojunction nanorods for high quantum yield and tunable color
Limitations of colloidal semiconductor double-heterojunction nanorods reported thus far are low photoluminescence quantum yield, low color purity owing to wide size distribution, and emission over a narrow range of energies in the visible spectrum. Here we report alterations to the synthetic route …
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Plastic scintillation spectrometry
Plastic scintillators provide homeland security organisations with large area, low cost gamma-ray counters at international borders. Currently these detectors cannot distinguish between the sources they detect, leading to high false alarm rates during primary screening. These alarms must be …
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Machine learning-based non-destructive evaluation of fatigue damage in metals
Non-destructive evaluation (NDE) of fatigue damage in metals is crucial for ensuring high product performance and safety. In remanufacturing, NDE for the incoming recycled metal materials is also essential to maximize the benefits of utilizing such materials. However, critical challenges exist in …
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Study on the photoelectric hot electrons generation and transport with metallic-semiconductor photonic crystals
Photoelectric hot carrier generation in metal-semiconductor junctions allows for optical-to- electrical energy conversion at photon energies below the bandgap of the semiconductor. Which opens new opportunities in optical sensors and energy conversion devices. In this thesis research, the …
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Analyses of electronic asymmetric rotor spectra
… (1,2-diazine) have been analyzed by rotational band contour analysis. The rotational constants, in either the upper or lower state, of each band were adjusted until the simulated contour reproduced the following features of the observed rotational contour: (1) the rotational peak …
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A Novel Neutron Recoil Spectrometer Concept Utilizing Heavy-Ion Recoils and Time- and Spatially-Resolved Sensor
… recoil neutron spectrometer as an alternative to existing magnetic proton recoil neutron spectrometers for inertial confinement fusion experiments. Whereas existing designs elastically scatter neutrons o↵ protons or deuterons, which are then magnetically analyzed to infer energy, this …
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Starbursts in the UV bright interacting galaxies NGC 3395 and NGC 3396
… Space Telescope (HST). The images show many isolated sources of ultraviolet emission which are young star forming regions with ages ≤8 x 107 years. Reddening of the star forming knots ranges from E(B--V) = 0.0 to E(B--V) = 0.3, indicating variable amounts of dust surrounding these regions. The …
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The synthesis of inorganic semiconductor nanocrystalline materials for the purpose of creating hybrid organic/inorganic light-emitting devices
… Their emission is efficient and their spectral full width at half maximum remains highly narrow as their size is synthetically changed to provide desired peak wavelengths of emission to within plus or minus a couple of nanometers. They can be purified and manipulated in solution and their …
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Investigation of Shocked Basalts from Vargeão Dome and Vista Alegre: Implications for the Search for Life on Mars
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 …
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Growth of Single Crystal, Metastable Ge(1-X)sn(x) Alloys and Ge(1-X)sn(x)/ge Strained-Layer Superlattices on Ge(001)2 X 1 by Molecular Beam Epitaxy
… $\rm Ge\sb{1-x}Sn\sb{x}$/Ge strained-layer superlattices (SLS) with x up to 0.24 (the equilibrium solid solubility of Sn in Ge is $<$0.01) were also grown on Ge(001)2x1 substrates using temperature-modulated molecular-beam epitaxy with maximum growth temperatures $\rm T\sb{s}\leq140\sp\circ$C. …
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Aluminum nitride microelectromechanical infrared detectors with integrated metamaterial absorbers
… (IR) detectors based on the seamless integration of metamaterial (MM) structures with microelectromechanical (MEMS) AlN resonators. Historically, uncooled absorbers have been limited in two key metrics: selectivity, the ability to distinguish distinct wavelengths of incident light, and …
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Non-Invasive Flow Measurement Via Distributed Acoustic Sensing Utilizing Frequency Spectra Analysis of Wall Pressure Fluctuations
… to noninvasively measure volumetric flow rate via multiple unique sensor styles. This work modifies previously used methods of flow detection via fiber optic acoustic sensors affixed onto the exterior body of a flow apparatus. Flow rate measurement methods for two unique sensor styles are …
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