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Studies in astronomical interference spectroscopy in the balloon ultravioletMcQuoid, J. A. January 1980 (has links)
No description available.
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Development and Application of 19F NMR of ProteinsKitevski-LeBlanc, Julianne 18 February 2011 (has links)
19F NMR studies of proteins provide unique insight into biologically relevant phenomena such as conformational fluctuations, folding and unfolding, binding and catalysis. While there are many advantages to the use of 19F NMR, experimental challenges limit its widespread application. The focus of this thesis has been to address some of these limitations, including resonance assignment and perturbations arising from fluorine probes, and to develop more robust methods of studying protein topology by 19F NMR.
19F NMR experiments designed to measure local hydrophobicity and exposure were developed and evaluated in two systems, Fyn SH3 and calmodulin, labeled with 3-fluorotyrosine. Paramagnetic effects from dissolved oxygen, solvent isotope shifts from deuterium oxide, and 1H-19F NOEs were each sufficient in establishing relative solvent exposure, while the combination of effects from oxygen and deuterium oxide were able to delineate local hydrophobicity and solvent accessibility of 19F probes.
Two NMR based resonance assignment protocols were developed using 13C, 15N-enriched 3-fluorotyrosine and 3-fluorophenylalanine, separately biosynthetically incorporated into calmodulin. In the first approach, isotopic enrichment facilitated two-dimensional heteronuclear experiments based on INEPT and COSY magnetization transfer schemes to correlate the fluorine nucleus to sidechain and backbone 1H, 13C, and 15N atoms, providing complete spectral assignment. The assignment of 3-fluorophenylalanine resonances was achieved using 19F-, and 15N-edited homonuclear NOE experiments to connect the fluorine nucleus to intraresidue and neighboring 1H and 15N resonances. While both strategies were successful, the NOE-based method was vulnerable to alternate relaxation mechanisms, including chemical shift anisotropy and chemical exchange.
Structural perturbations arising from uniform incorporation of 3-fluorophenylalanine in calmodulin was thoroughly investigated using 19F and 1H-15N NMR spectroscopy, 15N spin relaxation and thermal denaturation via circular dichroism spectroscopy. While stability was unaffected, NMR experiments revealed increased protein plasticity, minor conformers and line broadening. The merit of fractional fluorine labeling in reducing such disruptions was demonstrated, and labeling levels of 60-75% provided an optimal balance between native-likeness and the usual advantages of 19F NMR in our system.
The 19F NMR techniques developed here are broadly applicable and will expand the utility of 19F NMR in studies of protein systems.
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A Broadband Miniaturized Microwave Dielectric Spectroscopy System Based on Impedance SensingKabiri, Saman 1988- 02 October 2013 (has links)
The main purpose of this thesis is to propose a broadband miniaturized spectroscopy system to detect dielectric constant and loss tangent of lossy organic materials at RF/Microwave frequencies. Complex permittivities of lossy liquids are measured using voltage variations across a sensing element embedded in a capacitive divider circuit. The methodology for characterization of complex permittivity of materials is explained in detail.
The proposed method provides a unique detection algorithm to extract the dielectric constant and loss tangent of an unknown material exposed to the sensor. The complex permittivity of binary organic mixtures have been extracted to an accuracy better than 5% using sample volumes of 200-300 μL within the frequency range of 1-2 GHz. The results obtained from the measurements are compared to the reported values, and their agreements are presented in this work. To the best of the authors’ knowledge, this is the first work presented for broadband miniaturized self-sustained complex permittivity spectroscopy at microwave frequencies.
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Phosphorescence anisotropy studies of the protein moiety in human serum lipoproteinsKim, Heiryun January 1977 (has links)
No description available.
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Nuclear level density with interactionsChoudhury, Fatima N. January 1977 (has links)
No description available.
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Spectroscopical Analysis of Mechano-chemically Activated SurfacesCooper, Rodrigo 2011 August 1900 (has links)
Mechano-chemical activation is fundamentally different than chemical activation
in that energy is added to alter the state of bond energy instead of exciting electrons to
produce a chemical reaction. Mechano-chemical activation has demonstrated to alter the
chemical reaction and rates. There remains no development of a model to quantify the
changes in reactions due to mechano-chemical activation.
This research aims in expanding our understanding of the influence of mechanochemical
activation methods. The dynamics and kinetics of mechano-chemically
activated surfaces will be studied using x-ray spectroscopy methods. Mechano-chemical
interactions can be quantified through the study of electron energies.
X-ray spectroscopy is a useful method of analyzing and quantifying electron
energy states. X-ray absorbance is used to study the valence state electron shells of iron
undergone activation through sliding friction of naturally produced wax. In-situ x-ray
photoemission spectroscopy is employed to instantaneously characterize single crystal
tantalum samples of each principal crystallographic orientation during oxidation.
Sliding friction of the naturally produced wax resulted in a reduction in the
binding energy of the iron 2p electrons by approximately one electron-volt. This
reduction in binding energy is attributed to ferrocene which is an organo-metallic alloy,
Fe(C5H5)2.
Mechanical strain of the crystal lattices of tantalum resulted in altered activation
energies. Activation energy increased with the application of lattice strain. At increasing
strain, oxide properties become more dependent on the lattice strain than the crystal
orientation and temperature. A model system is developed incorporating mechanical
strain into the prediction of activation energy and rates.
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Vitamin assay by means of ultraviolet reflectance spectroscopyLieu, Van Tune January 1966 (has links)
Typescript. / Thesis (Ph. D.)--University of Hawaii, 1966. / Bibliography: leaves [92]-94. / ix, 94 l illus., tables
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Infrared spectroscopy and coordination chemistryGhosh, Surendra Nath January 1968 (has links)
Typescript. / Thesis (Ph. D.)--University of Hawaii, 1968. / Bibliography: leaves [83]-85. / viii, 85 l graphs, tables
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Far infrared optical properties of polycrystalline alkali halogenates / Optical properties of polycrystalline alkali halogenatesNeufeld, Jerry Don January 1972 (has links)
Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1972. / Bibliography: leaves [195]-199. / xiii, 199 l illus., tables
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Angular-dependent x-ray photoelectron spectroscopy of solidsBaird, Ronald J January 1977 (has links)
Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1977. / Bibliography: leaves 229-230. / Microfiche. / xii, 236 leaves ill
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