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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

Fluorescence spectra of s-tetrazine

Lowry, John Allen, 1949- January 1973 (has links)
No description available.
32

Laser studies of plasmas

Jacobs, Robert Michael James January 2000 (has links)
Measurement of the intrinsic properties of processing plasmas is critically important in understanding discharges so that the optimum conditions can be achieved. Several different diagnostic methods have been developed and tested. A planar probe has been used to measure the ion flux and electron temperature in both inductively coupled and capacitively coupled plasma systems, at various pressures and applied powers, using the assumption that the electron energy distribution is a Maxwellian.</p> Frequency modulation spectroscopy (FMS) has been used to detect species in a plasma. It has been shown to be very effective, giving a significantly increased S/N ratio compared to both single pass absorption and low frequency mechanical modulation techniques. It has been used to measure excited argon atom concentrations, in both capacitively and inductively produced plasmas. The argon atom 4s[3/2]<sub>1</sub> level concentration was found to be between 2 x 10<sup>8</sup> and 1 x 10<sup>11</sup> atom/cm<sup>3</sup> and to generally increase with increasing applied power and to decrease with increasing total pressure. The temperature of the atoms was also measured and was found to be approximately 323 ± 17 K. A simple compact laser source at 308 nm has been produced from a frequency doubled cooled commercial diode laser. This has been used to detect the OH radical, by absorption, within the afterglow of a microwave discharge, produced either directly or chemically. Simple kinetic models have provided explanations of the variations in OH concentration with discharge conditions. A novel method, cavity laser induced fluorescence (CLIP), that combines the advantages of both laser induced fluorescence (LIF) and cavity ring down spectroscopy CRDS, has been shown to increase the sensitivity of a diagnostic system compared to absorption. This method could be used to follow concentration variations of a reaction in a single laser shot. Although such variation can be observed using LIF, it requires a calibration and a many laser shot experiment with a signal recorded at each time point. Whilst CRDS allows temporal information about the absolute concentrations of the species observed to be obtained, it is not as sensitive as LIF. By combining the two in CLIP, it may be possible to retain the sensitivity of LIF with the advantage of CRDS so that absolute and time varying concentrations can be obtained in a single pulsed laser shot. LIF and CRDS signals have been observed using the A <sup>2</sup>?<sub>u</sub> ? X <sup>2</sup>S<sub>g</sub><sup>+</sup> transition of the N<sub>2</sub><sup>+</sup> ion. The lifetime of the A <sup>2</sup>?<sub>u</sub> state in the discharge was found to be sufficiently long for a time of flight experiment to be contemplated (an ion with a velocity of 10 kms<sup>-1</sup> on average would travel 5 mm before radiating). Although the preliminary tests for the time of flight experiment have shown that this method is not feasible with a pulsed laser, the basic cavity locking procedures required for an analogous continuous wave experiment have been successfully demonstrated. A frequency doubled diode laser source has been constructed and tested, with the eventual aim of detecting N<sub>2</sub><sup>+</sup> via the B <sup>2</sup>S<sub>u</sub> ? X <sup>2</sup>S<sub>g</sub><sup>+</sup> electronic transition. This has been found to be insufficiently intense to be used for a proposed two dimensional velocity mapping experiment, but several strategies to improve its performance are suggested.
33

Photoluminescent properties of bichromophoric perylenemonoimide and 9-amino-perylenemonoimide

Vasquez, Joan Acay. January 2007 (has links)
Thesis (M.S.)--University of Nevada, Reno, 2007. / "August 2007." Includes bibliographical references (leaves 36-38). Online version available on the World Wide Web.
34

The effect of lipid composition on cholesterol-rich domain size in model membranes /

Brown, Angela Carin. Wrenn, Steven Parker. January 2008 (has links)
Thesis (Ph.D.)--Drexel University, 2008. / Includes abstract and vita. Includes bibliographical references (leaves 198).
35

Spectroscopic investigations of acrylodan dye interactions with poly(amidoamine) and poly(propyleneimine) dendrimers

Rippey, Julie M. January 2008 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2008. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed July 13, 2009). Includes bibliographical references.
36

Developing an imaging bi-spectrometer for fluorescent materials /

Mohammadi, Mahnaz. January 2009 (has links)
Thesis (Ph.D.)--Rochester Institute of Technology, 2009. / Typescript. Includes bibliographical references (leaves 276-287).
37

Nanoscale imaging and spectroscopy of membrane organization /

Gould, Travis John, January 2009 (has links)
Thesis (Ph.D.) in Physics--University of Maine, 2009. / Includes vita. Includes bibliographical references (leaves 129-144).
38

Peptide electrophoresis by two-beam fluorescence cross-correlation spectroscopy

Brister, Paul Clifton. Weston, Kenneth D. January 2006 (has links)
Thesis (Ph. D.)--Florida State University, 2006. / Advisor: Kenneth D. Weston, Florida State University, College of Arts and Sciences, Dept. of Chemistry and Biochemistry. Title and description from dissertation home page (viewed Sept. 19, 2006). Document formatted into pages; contains xv, 96 pages. Includes bibliographical references.
39

Characterization of long pathlength capillary waveguides for evanescent fluorescence characterization

Paprocki, Eric Daniel. January 2007 (has links)
Thesis (M.S.)--University of Montana, 2007. / Title from title screen. Description based on contents viewed Sept. 25, 2007. Includes bibliographical references (p. 44-45).
40

Photosynthetic electron transport in purple bacteria: An in vivo spectroscopic study / Photosynthetic electron transport in purple bacteria: An in vivo spectroscopic study

BÍNA, David January 2009 (has links)
Electron transport in purple bacteria was studied using combination of absorption spectroscopy and induced bacteriochlorophyll fluorescence in whole cells in vivo. Focus is placed on relations between fluorescence yield, the state of the electron transport chain and the membrane potential. A laboratory-built absorption spectrophotometer-fluorimeter is described.

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