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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Spectroscopy of high-Z ions as a way to understanding the nature of Cas A knots and intergalactic shocks

Docenko, Dmitrijs January 2008 (has links)
The goal of the studies comprising this thesis is a survey of prospective spectroscopical methods of highly-charged ion observations from hot astrophysical plasmas that have not been widely studied before. The first main task that one needs to carry out in this case is a review of different types of spectral lines and matching types of astrophysical objects. This review is then followed by the development of the theoretical description and determination of the best observable parameters in the promising direction and application of the method to the specific objects. Two results of such study (combinations of spectral line type and object type) are presented in the thesis. The hyperfine structure lines of highly-ionized metal atoms (primarily the line of 14N VII at 5.652 mm) are shown to be observable with modern radio telescopes.The astrophysical objects responsible for appearance of these lines either in emission or in absorption are hot interstellar medium in the Galaxy and other galaxies, hot intracluster medium in clusters of galaxies, supernova remnants, gas around quasars and the warm-hot intergalactic medium, being the most interesting object for the application of the proposed method. The highly-ionized metal recombination lines in the optical and near-infrared ranges constitute another promising result of our studies. We have shown that the lines of this previously unstudied type should be strong enough to be observable even in moderate time on the modern ground-based optical telescopes from the dense knots of ejecta of the young Galactic supernova remnant Cassiopeia A. Such prospective observations will allow to identify all abundant ions present in the ejecta being crossed by the reverse shock wave of the supernova explosion, thus increasing our knowledge both on the ejecta composition and details of the shock wave interaction with the metal-dominated dense clouds. In the course of the work, it was realized that the physical conditions in the emitting regions of these dense ejecta clouds (so-called fast-moving knots) of Cassiopeia A and other young oxygen-dominated supernova remnants are rather unconstrained with predictions of different models for the line intensities varying by orders of magnitude. To make better estimates of these conditions from the existing data, we have utilized the archival observations of ISO and Spitzer space observatories to determine the diagnostic fine-structure line ratios. Analysis of this observational data set has resulted in understanding of relative importances of various processes proposed in different theoretical models, as well as in determination of physical parameters in some of previously observationally unexplored regions of the fast-moving knots. This study is also included in the thesis. / Disertācija izstrādāta un aizstāvēta Minhenē.
32

Electronic spectroscopy of various molecular systems by low-energy, variable-angle, electron impact

Frueholz, Robert Paul. Kuppermann, Aron. January 1978 (has links)
Thesis (Ph. D.)--California Institute of Technology, 1978. UM #78-15,971. / Advisor names found in the Acknowledgments pages of the thesis. Title from home page. Viewed 01/19/2010. Includes bibliographical references.
33

Studies of alkyl free radicals and reaction mechanisms by photoelectron spectroscopy

Houle, F. A. Goddard, William A., Beauchamp, Jesse L. January 1979 (has links)
Thesis (Ph. D.)--California Institute of Technology, 1979. UM #79-19,851. / Advisor names found in the Acknowledgments pages of the thesis. Title from home page. Viewed 01/20/2010. Includes bibliographical references.
34

Ultra low signals in ballistic electron emission microscopy

Heller, Eric, January 2003 (has links)
Thesis (Ph. D.)--Ohio State University, 2003. / Title from first page of PDF file. Document formatted into pages; contains xvii, 237 p.; also includes graphics. Includes abstract and vita. Advisor: Jonathan P. Pelz, Dept. of Physics. Includes bibliographical references (p. 232-237).
35

High-resolution nonlinear laser wave-mixing spectroscopy for gas-phase environmental and atmospheric studies /

Briggs, Ronald D. January 2004 (has links)
Thesis (Ph. D.)--University of California, San Diego and San Diego State University, 2004. / Vita. Includes bibliographical references (leaves 192-200).
36

USE OF THE INDUCTIVELY-COUPLED PLASMA FOR THE ELEMENTAL ANALYSIS OF ORGANIC COMPOUNDS

Windsor, David Lee, 1945- January 1977 (has links)
No description available.
37

Application of photoacoustic techniques to solid and liquid materials

Aravind, Manju. January 1994 (has links)
published_or_final_version / Physics / Master / Master of Philosophy
38

Investigations into the role of a premixed oxygen-hydrogen flame in flame emission spectrometry

Gutzler, David Eugene, 1949- January 1973 (has links)
No description available.
39

Thermoreflectance of amorphous GeTe

Kottke, Michael Lee, 1947- January 1974 (has links)
No description available.
40

Photoelectron Imaging of Molecular and Cluster Anions

Surber, Sean Eric January 2005 (has links)
Femtosecond negative-ion photoelectron imaging spectroscopy allows the probing of dynamics resulting from solvation and photodissociation in both the time-resolved and solvent domains. First, the basic premise of photoelectron imaging shall be presented, followed by a discussion of qualitative approaches for interpreting photoelectron angular distributions as illustrated by application to the photoelectron images of S₂⁻ and CS₂⁻. The photoelectron images of CS₂⁻ serve as a reference for interpreting the results for homogeneous and heterogeneous solvation in CO₂ and OCS cluster anions. The effects of solvation upon the photoelectron angular distribution and the photoelectron energy spectrum are discussed in relation to (OCS)n⁻, OCS⁻·H₂O, (CO2)n⁻, and (CO₂)n(H₂O)m⁻. The (OCS)₂⁻ cluster anion images show evidence of competition of excited state decay pathways and coexistence of isomers. The evolution of photoelectron images, resulting from I₂Br⁻ dissociation shows the evolving electronic structure of the I⁻ channel as the anion dissociates.

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