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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.
71

Development of an electron time of flight spectrometer for ultrafast pulse characterization and ultrafast dynamics studies

Timilsina, Pratap January 1900 (has links)
Master of Science / Department of Physics / Carlos Trallero / This report presents the details of an electron time-of-flight (ETOF) spectrometer to be used for characterizing ultrafast electric field pulses. The pulses will range in pulse-duration from femtosecond to attoseconds and in wavelength from the far infrared (FIR) to the extreme ultra violet (XUV). By measuring the photoelectrons in the presence of two electric fields and their quantum interference we will be able to extract the amplitude and phase of the electric field. For XUV pulses this is the well-known streaking and Reconstruction of Attosecond Beating by Interference of Two-Photon Transition (RABITT) method. The ETOF is based on a set of tunable electrostatic lenses capable of detecting 0-150 eV electrons. In addition, we can selectively increase the photoelectron yield of the spectrum. The precise tuning of the electrostatic lens system is done with a Genetic Algorithm (GA) with an intensity fluctuation discriminator in the fitness.
72

Development of novel oxidation catalysts for carbon isotope ratio analysis

Fomes, Charles William January 2000 (has links)
No description available.
73

Design of a bore sight camera for the lineate image near ultraviolet spectrometer (LINUS)

Cabezas, Rodrigo. 06 1900 (has links)
Approved for public release; distribution is unlimited. / The Lineate Image Near Ultraviolet Spectrometer (LINUS) is a spectral imager that works in the ultraviolet region of the spectrum. This thesis describes the latest of several steps in the development of this instrument. Due to the narrow field of view of the instrument, 2.5 x 0.5 degrees, an accurate pointing method is necessary; also, a scheme of quality evaluation of the post-processed spectral image is desirable. A way to achieve both goals was developed by designing and implementing the layout for two visual cameras, wide and narrow field of view, and a method to capture the images in order to perform the subsequent comparison with the processed spectral image. Since this is the first time the system is working in full-automated mode, a new wavelength calibration with the emission lines from a platinum hollow cathode lamp was performed and a new response curve for sulfur dioxide (SO2) was taken. Finally, laboratory and outdoor field observations were conducted to test the system integration. / Lieutenant, Chilean Navy
74

Spectral response function characterization methodologies for imaging spectrometers

Czapla-Myers, Jeffrey S. January 2000 (has links)
Thesis (M. Sc.)--York University, 2000. Graduate Programme in Earth and Space Science. / Typescript. Includes bibliographical references (leaves 107-111). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pMQ56168.
75

Characterisation of coal slurries for introduction into ICP OES for multi-element determinations

Mujuru, M, McCrindle, RI, Panichev, N 19 February 2009 (has links)
Abstract The characterisation and stability of coal slurries for introduction into an inductively coupled plasma optical emission spectrometer (ICP OES) and the application of slurries in the analysis of coal was investigated. The importance of rheology and the stability of the coal slurries on the analytical results produced by ICP OES was demonstrated. The homogeneity and stability of various coal slurries were characterised by sedimentation tests, scanning electron microscopy (SEM), zeta potential and viscosity measurements. The porosities and surface areas of different South African coals and a mechanism for the adsorption of the dispersants onto the coals were determined using low-temperature nitrogen physisorption studies. The possibility of partially solubulising the coal in N,N-dimethylformamide (DMF) was investigated. SEM indicated that DMF solubulised coal fines and that 0.1% (m/v) Triton X-100 with 10% (v/v) DMFresulted in well dispersed slurries relative to other dispersants (glycerol, PEI and water). Slurry analysis of coarse and ground coal in 0.1% (m/v) Triton X-100, showed that higher emission intensities and better precision was obtained when using ground coal. This was confirmed by lower RSDs (less than 5% for most of the elements analysed) relative to the unground, coarse coal. Glycerol slurries gave higher RSDs (higher than 5% for most of the elements) most of the time, thus negatively influencing the precision of measurement. Physisorption studies indicated that ground coal had up to ten times higher surface areas than coarse coal. The higher surface areas for fine ground coals suggested why they were better dispersed and thus better transported into the plasma, resulting in higher emission signals. Zeta potentials indicated that for all dispersants, the coal particles were well repelled from each other, although SEM pictures indicated better dispersion for 0.1% (m/v) Triton X-100 with 10% (v/v) DMF. It was demonstrated that higher intensities and higher precision could be obtained with well dispersed and stable coal slurries.
76

An electron spectrometer using adiabatic motion in a magnetic field /

Rouleau, Gary. January 1986 (has links)
No description available.
77

Optimization studies of high performance liquid chromatograph/inductively coupled plasma atomic emission spectrometer interface

Whaley, Brenda Elaine Spears 12 1900 (has links)
No description available.
78

Optical studies of thermoluminescent materials / by Phillip James Fox

Fox, Phillip James January 1990 (has links)
Bibliography: leaves 120-127 / iv, 127, [158] leaves : ill., map ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physics and Mathematical Physics, 1990
79

Two facets of the x-ray microanalysis at low voltage the secondary fluorescence x-rays emission and the microcalorimeter energy-dispersive spectrometer /

Demers, Hendrix. January 1900 (has links)
Thesis (Ph.D.). / Written for the Dept. of Mining and Materials Engineering. Title from title page of PDF (viewed 2008/01/12). Includes bibliographical references.
80

Ultra-compact holographic spectrometers for diffuse source spectroscopy

Hsieh, Chaoray. January 2008 (has links)
Thesis (Ph. D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Adibi, Ali; Committee Member: Chang, Gee-Kung; Committee Member: Ralph, Stephen; Committee Member: Trebino, Rick; Committee Member: Verriest, Erik I.

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