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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.
251

Influence of aerosol properties on signals and interferences in optical atomic spectrometry

Farino, John 12 1900 (has links)
No description available.
252

Single molecule mechanical testing

Lillehei, Peter Thomas 05 1900 (has links)
No description available.
253

Fundamental studies of aerosol sample introduction in optical atomic spectrometry

Smith, David Dean 12 1900 (has links)
No description available.
254

Intelligent autonomous inductively coupled plasma instrumental operation

Webb, Douglas P. January 1996 (has links)
The development of a framework for the automated analysis of inductively couple plasma atomic emission spectroscopy is present. Some of the research that lead to current state of this framework is presented. A small expert system that uses information about the current sample to generate a line search strategy which minimizes the number of emission lines which need to be measured, and avoids spectral overlaps when possible. A program is presented that evaluates the minimum number of spectral windows required to perform elemental analysis by ICP-AES, given a certain spectral window width. A method with the potential for rapidly ascertaining the physical properties of the sample matrix is presented. This system has the potential to help reduce sample introduction related system failures. Finally, three optimization algorithms are compared in their ability to optimize ICP-AES performance, from this an optimization module was developed for inclusion in the automated analysis framework.
255

Collinear fast-beam laser spectroscopy at ISAC

Cocolios, Thomas Elias January 2005 (has links)
Collinear fast-beam laser spectroscopy is a method of studying atomic and ionic hyperfine structure where a particle beam and a laser beam are superposed along the same line. Such a facility exists at ISAC, TRIUMF, Vancouver, BC, and was designed especially for polarising radioactive beams of alkali metals. / In order to produce polarised fluorine for the use in NMR, the hyperfine structure of the 3s 4P 5/2 and 3p 4D 7/2 states has to be known. The hyperfine coefficients for those two levels are measured for the first time to be A = 2645.6(6) MHz and A = 1565.6(4)MHz respectively. The 3p 4D5/2 state is also studied to measure the metastable atom fraction and its hyperfine constant is measured to be A = 1148(5)MHz. / A study of lanthanum ions is also carried out. Spectra for the 6 s2 1S0 to 5 d6p Do13 transition are measured with stable 139La to evaluate the sensitivity of the equipment and with radioactive 139La for preliminary commissioning of the isotope shift study.
256

Quantum Trajectories of a Superconducting Qubit

Weber, Steven Joseph 27 March 2015 (has links)
<p> In quantum mechanics, the process of measurement is intrinsically probabilistic. As a result, continuously monitoring a quantum system will randomly perturb its natural unitary evolution. An accurate measurement record documents this stochastic evolution and can be used to reconstruct the quantum trajectory of the system state in a single experimental iteration. We use weak measurements to track the individual quantum trajectories of a superconducting qubit that evolves under the competing influences of continuous weak measurement and Rabi drive. We analyze large ensembles of such trajectories to examine their characteristics and determine their statistical properties. For example, by considering only the subset of trajectories that evolve between any chosen initial and final states, we can deduce the most probable path through quantum state space. Our investigation reveals the rich interplay between measurement dynamics, typically associated with wavefunction collapse, and unitary evolution. Our results provide insight into the dynamics of open quantum systems and may enable new methods of quantum state tomography, quantum state steering through measurement, and active quantum control.</p>
257

Convergence in large R-matrix calculations

Stafford, Ronald Philip January 1991 (has links)
No description available.
258

Background correction procedures and developments in spectrometer design for ICP-AES

Hall, D. H. January 1986 (has links)
No description available.
259

An experimental analysis of the transverse Zeeman intensity pattern of the 6647 A forbidden line of Hg II

Stienecker, Craig A., 1947- January 1974 (has links)
This thesis project has involved a study of forbidden radiation: a phenomenon studied in the discipline of Atomic Spectroscopy. Specifically, the forbidden spectral line 6647 A of Hg II was examined. This line is of mixed multipolarity in that it is composed of magnetic-dipole and electric-quadrupole radiation. Emission of these two multipolarities gives rise to an interference effect which is quite useful in determining the degree to which each multipolarity contributes to this forbidden line.The results of the study carried out here agree with the theoretical predictions made for this line. They indicate that less than two percent electric-quadrupole radiation is present in the line. This study of the interference effect demonstrates the importance of obtaining both the transverse and longitudinal views of the line relative to the direction of the magnetic field. Both views, it is felt, are necessary for experimental verification of the line's structure.
260

L-squared approximations in atomic scattering theory

Plummer, Martin January 1987 (has links)
This thesis is concerned with the use of L-squared or square integrable functions in electron atom scattering at intermediate energies, and tests the success of various L-squared approximations in model problems of electron hydrogen atom scattering. The representation of part or all of the wave and Green's functions by a set of L-squared pseudostates, and the associated occurrence of unphysical pseudoresonances at the pseudostate thresholds is discussed. The original work of this thesis is in two parts. In the first, a model coupled channel problem is considered in which an L-squared optical potential is used to represent the effect of additional (Q space) channels on the first (P space) channel. A method of Bransden and Stelbovics used successfully for a two channel problem is extended to the case of several channels. Numerical results are presented for the cases of two and three channels and the success of the procedure is assessed. The rest of the research presented here concerns the use of the Schwinger variational method in a restricted model of electron hydrogen atom scattering in which all states are assumed to be spherically symmetric. The method is used successfully to solve coupled channel problems using L-squared pseudostates to represent the s-wave continuum. The origins of the pseudoresonances that occur in these problems are investigated and a method of removing pseudoresonances before T matrix elements are calculated is considered. The limitations and instabilities of the Schwinger method when applied to the full model problem with different representations of hydrogen states in the trial and Green’s functions are investigated, and various modifications are considered in attempts to stabilise results where necessary in these more general cases.

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