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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.
21

Investigation of Inductively Coupled Plasma as an Atomization Source for Analytical and Fundamental Measurements Using Cavity Ringdown Spectroscopy

Mazzotti, Fabio Jerome 11 December 2004 (has links)
Analytical as well as fundamental measurements were performed with an inductively coupled plasma (ICP) using the novel technique of cavity ringdown spectroscopy. A newly designed ICP torch was presented. Limits of detection were measured for elemental mercury, both in an ICP as well as in a cold mercury chemical generator. The efficiency of the technique was compared with laser-induced fluorescence (LIF) in the ICP. Isotopically resolved spectra of uranium were collected with this technique and results were compared to previous studies using LIF. Gas temperature and electron density estimations were done by lineshape measurements on lead atoms in the ICP. Abel inversion technique was used to extract absolute atom densities and ringdown proved to be an excellent candidate for trace detection when coupled with an atomization source. Spectra of hydroxyl radical coming from dissociation of water molecules in air were recorded and OH density was estimated. The plasma was found to be in local thermal equilibrium by comparing simulated and measured OH emission spectra. Future developments of cavity ringdown with ICP using continuous-wave lasers are discussed.
22

ANALYTICAL SPECTROSCOPIC CAPABILITIES OF OPTICAL IMAGING CHARGE TRANSFER DEVICES.

BILHORN, ROBERT BYERS. January 1987 (has links)
The investigations described within this dissertation foretell the imminent revolution in optical analytical spectroscopy and conclusively demonstrate superior qualitative and quantitative analysis performance of a new system for atomic spectroscopy as compared to present, state-of-the-art instrumentation. The advent of a new class of multichannel detectors, the silicon charge transfer devices (CTDs) is shown to significantly impact ultraviolet, visible, and near-infrared analytical spectroscopy. An overview of the operation, characteristics, and performance of CTDs is presented including the results of the characteristics of a CTD detector system developed during these investigations. Theoretical comparisons of the performance obtainable in spectroscopic systems employing CTD detectors versus conventional detectors, including equations identifying the factors limiting sensitivity, demonstrate that CTDs offer superior performance. The second part of this dissertation describes the application of a particular CTD, the charge injection device (CID), to a very challenging spectroscopic problem, as far as light detection is concerned, simultaneous multielement analytical atomic emission spectroscopy. This widely employed technique for qualitative and quantitative elemental analysis requires sensitive and wide dynamic range detection of a large number of spectral resolution elements. This research resulted in the development of a novel echelle spectrometer employing a CID detector which has been demonstrated to be capable of solving many of the problems currently encountered in analytical atomic spectroscopy. The system achieves superior sample throughput rates, flexibility, accuracy and precision as compared to sequential spectrometers employing a single detector and to polychromators employing relatively few fixed detectors. The research included the development of a unique method of operating the CID, which is used to cope with the very wide dynamic range signals encountered in atomic spectroscopy, and has resulted in a spectroscopic instrument able to qualify simultaneously major and trace components of extremely complex samples with greater sensitivity and accuracy than possible with conventional instrumentation. New, very flexible, and extremely rapid methods of qualitative analysis have also been developed which virtually eliminate the possibility of spectral line misassignment. The atomic emission spectroscopic system is applicable in a variety of analytical areas as diversified as high sensitivity detection of near infrared spectral lines and element-specific detection of chromatographic eluents.
23

Espectroscopia atômica em uma armadilha magneto-ótica / Atomic spectroscopy in a magneto-optical trap

Lima, Rodrigo Alves de 18 April 2011 (has links)
Espectroscopia atômica em uma armadilha magneto-ótica / Atomic spectroscopy in a magneto-optical trap
24

Classical and quantum dynamics of atomic systems in the proximity of dielectric waveguides

Modoran, Andrei V., January 2006 (has links)
Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 197-200).
25

Environmental mercury monitoring in the South African Highveld region.

Trüe, Andreas January 2010 (has links)
Thesis (MTech. degree in Chemistry)--Tshwane University of Technology, 2010. / Discusses an accurate and sensitive method for the determination of trace levels of mercury in environmental air samples may be established using cost effective technologies.
26

Determination of copper and zinc at trace levels in human hair using a direct sample insertion technique for inductively coupled plasma atomic emission spectrometry

Monasterios, Clevys Josefina. January 1985 (has links)
No description available.
27

Atomic absorption spectroscopic determination of mercury, selenium and arsenic in biological and environmental materials /

Dhindsa, Harkirat S. January 1900 (has links)
Thesis (Ph.D.)--University of Western Sydney, Nepean, 1998. / Includes bibliographies.
28

Two-photon ionization of the calcium 4s3d 1D2 level in an optical dipole trap /

Daily, Jared Estus, January 2005 (has links) (PDF)
Thesis (M.S.)--Brigham Young University. Dept. of Physics and Astronomy, 2005. / Includes bibliographical references (leaves 20-24).
29

Collisional depolarization of the atomic Cs 6s<sup>2</sup>S<sub>1/2</sub>-10s<sup>2</sup>S<sub>3/2</sub>,9d<sup>2</sup>D<sub>5/2</sub> transition with argon buffer gas

Seda, Kin. January 2005 (has links)
Thesis (Master of Science)--Miami University, Dept. of Physics, 2005. / Title from first page of PDF document. Document formatted into pages; contains [1], ???, ??? p. : ill. Includes bibliographical references (p. Xx-Xx).
30

Espectroscopia atômica em uma armadilha magneto-ótica / Atomic spectroscopy in a magneto-optical trap

Rodrigo Alves de Lima 18 April 2011 (has links)
Espectroscopia atômica em uma armadilha magneto-ótica / Atomic spectroscopy in a magneto-optical trap

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