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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.
81

Kuder-Strong discrepancy in relation to conflict and congruence of vocational preference.

Margolis, Victor Herbert. January 1967 (has links)
Thesis (Ed.D.)--Teachers College, Columbia University, 1967. / Typescript; issued also on microfilm. Sponsor: Roger A. Myers. Dissertation Committee: Donald E. Super. Includes bibliographical references.
82

Beyond antebellum sectionalism New York City's local scene during the 1850s as reflected in the New York Times /

Parkinson, Jacquelyn Ruth, January 2008 (has links) (PDF)
Thesis (M.A. in history)--Washington State University, December 2008. / Title from PDF title page (viewed on Mar. 9, 2009). "Department of History." Includes bibliographical references (p. 126-134).
83

An investigation of some experimental consequences of analytic continuation in energy for strong-interaction partial-wave amplitudes

Balázs, L. A. P. January 1962 (has links)
Thesis (Ph.D.)--University of California, Berkeley, 1962. / "UC-34 Physics" -t.p. "TID-4500 (17th Ed.)" -t.p. Includes bibliographical references (p. 57-59).
84

Hemispherical optical microcavity for cavity-QED strong coupling

Hannigan, Justin Michio, 1977- 12 1900 (has links)
xv, 204 p. : ill. (some col.) A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / This thesis reports on progress made toward realizing strong cavity quantum electrodynamics coupling in a novel micro-cavity operating close to the hemispherical limit. Micro-cavities are ubiquitous wherever the aim is observing strong interactions in the low-energy limit. The cavity used in this work boasts a novel combination of properties. It utilizes a curved mirror with radius in the range of 40-60 µm that exhibits high reflectivity over a large solid angle and is capable of producing a diffraction limited mode waist in the approach to the hemispherical limit. This small waist implies a correspondingly small effective mode volume due to concentration of the field into a small transverse distance. The cavity assembled for this investigation possesses suitably low loss (suitably low linewidth) to observe vacuum Rabi splitting under suitable conditions. According to best estimates for the relevant system parameters, this system should be capable of displaying strong coupling. The dipole coupling strength, cavity loss and quantum dot dephasing rates are estimated to be, respectively, g = 35µeV, κ = 30µeV, and γ = 15µeV. A survey of two different distributed Bragg reflector (DBR) samples was carried out. Four different probe lasers were used to measure transmission spectra for the coupled cavity-QED system. The system initially failed to display strong coupling due to the available lasers being too far from the design wavelength of the spacer layer, corresponding to a loss of field strength at the location of the quantum dots. Unfortunately, the only available lasers capable of probing the design wavelength of the spacer layer had technical problems that prevented us from obtaining clean spectra. Both a Ti:Al 2 O 3 and a diode laser were used to measure transmission over the design wavelength range. The cavity used here has many promising features and should be capable of displaying strong coupling. It is believed that with a laser system centered at the design wavelength and possessing low enough linewidth and single-mode operation across a wide wavelength range strong coupling should be observable in this system. / Committee in charge: Hailin Wang, Chairperson, Physics; Michael Raymer, Advisor, Physics; Jens Noeckel, Member, Physics; Richard Taylor, Member, Physics; Andrew Marcus, Outside Member, Chemistry
85

Properties of Sequent-Calculus-Based Languages

Johnson-Freyd, Philip 10 April 2018 (has links)
Programmers don't just have to write programs, they are have to reason about them. Programming languages aren't just tools for instructing computers what to do, they are tools for reasoning. And, it isn't just programmers who reason about programs: compilers and other tools reason similarly as they transform from one language into another one, or as they optimize an inefficient program into a better one. Languages, both surface languages and intermediate ones, need therefore to be both efficiently implementable and to support effective logical reasoning. However, these goals often seem to be in conflict. This dissertation studies programming language calculi inspired by the Curry-Howard correspondence, relating programming languages to proof systems. Our focus is on calculi corresponding logically to classical sequent calculus and connected computationally to abstract machines. We prove that these calculi have desirable properties to help bridge the gap between reasoning and implementation. Firstly, we explore a persistent conflict between extensionality and effects for lazy functional programs that manifests in a loss of confluence. Building on prior work, we develop a new rewriting theory for lazy functions and control which we first prove corresponds to the desired equational theory and then prove, by way of reductions into a smaller system, to be confluent. Next, we turn to the inconsistency between weak-head normalization and extensionality. Using ideas from our study of confluence, we develop a new operational semantics and series of abstract machines for head reduction which show us how to retain weak-head reduction's ease of implementation. After demonstrating the limitations of the above approach for call-by-value or types other than functions, we turn to typed calculi, showing how a type system can be used not only for mixing different kinds of data, but also different evaluation strategies in a single program. Building on variations of the reducibility candidates method such as biorthogonality and symmetric candidates, we present a uniform proof of strong normalization for our mixed-strategy system which works so long as all the strategies used satisfy criteria we isolate. This dissertation includes previously published co-authored material.
86

Strong-field driven dynamics of metal and dielectric nanoparticles

Powell, Jeffrey January 1900 (has links)
Doctor of Philosophy / Department of Physics / Artem Rudenko / Christopher M. Sorensen / The motion of electrons in atoms, molecules, and solids in the presence of intense electromagnetic radiation is an important research topic in physics and physical chemistry because of its fundamental nature and numerous practical applications, ranging from precise machining of materials to optical control of chemical reactions and light-driven electronic devices. Mechanisms of light-matter interactions critically depend on the dimensions of the irradiated system and evolve significantly from single atoms or molecules to the macroscopic bulk. Nanoparticles provide the link between these two extremes. In this thesis, I take advantage of this bridge to study light-matter interactions as a function of nanoparticle size, shape, and composition. I present here three discrete, but interconnected, experiments contributing to our knowledge of nanoparticle properties and their response to intense, short-pulsed light fields. First, I investigate how individual nanoparticles interact with each other in solution, studying their temperature-dependent solubility. The interaction potential between 5.5nm gold nanoparticles, ligated by an alkanethiol was found to be -0.165eV, in reasonable agreement with a phenomenological model. The other two experiments explore ultrafast dynamics driven by intense femtosecond lasers in isolated, gas-phase metallic and dielectric nanoparticles. Photoelectron momentum imaging is applied to study the response of gold, silica, and gold-shell/silica-core nanoparticles (ranging from single to several hundred nanometers in size) with near-infrared (NIR), 25 fs laser pulses in the intensity range of 10¹¹ - 10¹⁴ W/cm². These measurements, which constitute the bulk of my graduate work, reveal the complex interplay between the external optical field and the induced near-field of the nanoparticle, resulting in the emission of very energetic electrons that are much faster than those emitted from isolated atoms or molecules exposed to the same light pulses. The highest photoelectron energies (“cutoffs”) were measured as a function of laser intensity, nanoparticle material and size. We found that the energy cutoffs increase monotonically with laser intensity and nanoparticle size, except for the gold/silica hybrid where the plasmon resonance response modifies this behavior at low intensities. The measured photoelectron spectra for metallic nanoparticles display a large energy enhancement over silica. Finally, the last part of this thesis explores the possibility to apply time-resolved x-ray scattering as a probe of the ultrafast dynamics in isolated nanoparticles driven by very intense (~10¹⁵ W/cm²) NIR laser radiation. To do this, I developed and built a nanoparticle source capable of injecting single, gas-phase nanoparticles with a narrow size distribution into the laser focus. We used femtosecond x-ray pulses from an x-ray free electron laser (XFEL) to map the evolution of the laser-irradiated nanoparticle. The ultrafast dynamics were observed in the single-shot x-ray diffraction patterns measured as a function of delay between the NIR and x-ray pulses, which allows for femtosecond temporal and nanometer spatial resolution. We found that the intense IR laser pulse rapidly ionizes the nanoparticle, effectively turning it into a nanoplasma within less than a picosecond, and observed signatures of the nanoparticle surface softening on a few hundred-femtosecond time scale.
87

Um algoritmo para a construção de superfícies potenciais de falha em sólidos tridimensionais

Claro, Gláucia Kelly Silvestre [UNESP] 19 August 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-08-19Bitstream added on 2014-06-13T19:58:06Z : No. of bitstreams: 1 claro_gks_me_bauru.pdf: 1638801 bytes, checksum: 64af55b7016b44956f54e04a50b76b3c (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho tem o propósito de contribuir para a generalização tridimensional de problemas de análise numérica da propagação de fissura, mediante a formulação de elementos finitos com descontinuidade incorporada. Em problemas planos as descontinuidades correspondem a linhas que podem ser elaboradas de uma forma relativamente simples, através da construção sequencial de segmentos retos, orientados conforme a direção de falha no interior de cada elemento finito do sólido. Na análise tridimensional a construção do caminho de descontinuidade é mais complexa, pois devem ser construídas superficiais planas no interior de cada elemento e essas superfícies planas devem ser contínuas entre os elementos. É apresentada, nesse trabalho, uma técnica alternativa de construção do caminho de descontinuidade em análises tridimensionais baseado na solução de um problema análogo ao problema de condução de calor, estabelecido a partir de orientações locais de falha, baseado no estado de tensão do problema mecânico. A solução do problema equivalente é obtida utilizando a mesma malha e interpolações do problema mecânico. Para minimizar o esforço computacional, é proposta uma estratégia na qual a análise para mapear o caminho da descontinuidade é restrita ao domínio formado por alguns elementos próximos à superfície de fissura, que se desenvolve ao longo do processo de carregamento. Para validar a metodologia proposta foram realizadas análises tridimensionais de problemas básicos de fratura experimentais e seus resultados foram contrastados com os resultados encontrados na bibliografia. Realizou-se também a comparação do tempo de processamento entre o algoritmo proposto e o algaritmo global para as mesmas análises mencionadas acima. Como resultado, constatou-se que o algoritmo proposto conseguiu descrever satisfatoriamente as trajetórias de descontinuidade, consumindo menor tempo de processamento / This work contributes to the generalization to 3D problems of numerical analysis of crack propagation, through finite elements formulation with embedded discontinuity. In plane problems the discontinuities correspond to lines that can be tracked in a relatively simple way, by sequentially constructing straight segments, following the crack orientation inside each solid finite elements. In tree-dimensional analysis the tracking scheme is more complex since planar surfaces must be constructed inside each element and these planar surfaces must be continuous between elements. It is show in this work, an alternative version of discontinuity path construction technique in three-dimensional analysis based on the solution of an analogous heat conduction problem, established from the local failure orientation based on the stress state of the mechanical problem. The solution of the equivalent problem is obtained using the same mesh and interpolations of the mechanical problem. To minimize computational effort, a strategy is proposed in which the analysis to track the discontinuity path is restricted to the domain formed by few elements near the crack surface front, which develops along the loading process. To validate the poposed methodology three-dimensional analysis of experimental fracture test were performed and the results were contrasted with those obtained from the literature. The comparison between the process time of the proposed algorithm and the global algorithm was performed too. It was found that the proposed algorithm was able to describe the discontinuity path satisfactorily with reduced computational time
88

The Dynamically Assisted Schwinger Process:

Otto, Andreas 17 January 2018 (has links) (PDF)
The dynamical Schwinger effect refers to the creation of electron-positron pairs by a time dependent, spatially homogeneous electric field. It probes the fundamentals of quantum electrodynamics and is sought to be verified with upcoming high-intensity laser installations. In the dynamically assisted Schwinger effect, the pair yield is increased by orders of magnitude through the combination of fields of different field strength and frequency scales. In this thesis we, investigate both processes in the framework of a quantum kinetic equation. We are especially interested in what amplification factors can be achieved by the assisting field and whether intermediately large mode occupation numbers have a physical significance and could serve as a verification of the Schwinger effect. For the latter goal, we couple our system to a quantized radiation field that serves as a secondary (photon) probe and study its spectrum, as the afterglow of the dynamical Schwinger effect. / Als dynamischen Schwingereffekt bezeichnet man die Erzeugung von Elektron-Positron-Paaren durch ein zeitabhängiges, räumlich homogenes elektrisches Feld. Er dient zur Untersuchung der Grundlagen der Quantenelektrodynamik und es wird versucht, ihn an zukünftigen Hochintensitäts-Laseranlagen zu verifizieren. Bei dem dynamisch assistierten Schwingereffekt wird die Paarausbeute durch eine Kombination von Feldern mit unterschiedlichen Feldstärken- und Frequenzskalen um mehrere Größenordnungen erhöht. In dieser Dissertation untersuchen wir beide Prozesse im Rahmen einer quantenkinetischen Gleichung. Wir interessieren uns besonders dafür, welche Verstärkungsfaktoren durch das assistierende Feld erreicht werden können und ob intermediär große Modenbesetzungszahlen physikalische Signifikanz haben und als Verifizierung des Schwingereffekts dienen können. Für zweiteres Ziel koppeln wir unser System an ein quantisiertes Strahlungsfeld, das als sekundäres (Photonen-) Signal dient, und untersuchen dessen Spektrum, das Nachglühen des dynamischen Schwingereffekts.
89

Investigating the interrelationships among various measures of family strengths

Wheeler, Tony January 1900 (has links)
Doctor of Philosophy / Department of Family Studies and Human Services / Walter R. Schumm / The study of family strengths, as opposed to family dysfunction, has increased over the past few decades. Six interrelated components of family strength were identified that may affect the degree of marital satisfaction of husbands and wives. The six components - worth, commitment to relationship stability, commitment to relationship growth, communication, positive interaction, and time spent together - are characteristics within a family that may have substantial connections. Identical surveys were administered to couples in three major metropolitan areas. The data for the study were a sub-sample of data collected as a mail survey as part of a larger survey of membership retention within a mainline Protestant denomination. The main mail survey contained 10 pages. For about one-third of the sample, an additional two-page survey was given concerning premarital counseling and marital satisfaction. Another third of the sample was given an additional 2-page survey on family strengths and marital satisfaction. In addition to 20 family strengths items, those surveyed were asked to respond to the three questions of the Kansas Marital Satisfaction Scale. Data from these couples were used to test a hypothesized model of the interrelationships between the various measures of family strength using a detailed path analysis model with marital satisfaction as the dependent variable. The variables worth, commitment, communication, positive interaction, and time together functioned as intervening variables in the model with age, gender, various measures of religiosity, income, education, and age of children functioning as independent variables. The data were then analyzed by ordinary least squares regression techniques to test the model using marital satisfaction as the dependent variable. The results of testing the model indicated that strength in certain characteristics predicted strength in other characteristics at statistically significant levels (p < .05). Intrinsic religiosity predicted worth. Worth predicted commitment to stability and commitment to growth. The two areas of commitment predicted communication. Communication predicted positive interaction. Positive interaction predicted time together, and strengths in most of the characteristics predicted marital satisfaction. It is important for researchers, educators, therapists, and other professionals who work with families to gain an understanding and awareness of the current breakdown of marriage and family in our Western society. A greater understanding of family strengths and how they work together is crucial to providing families and family professionals with information useful for supporting family systems.
90

Inference in inhomogeneous hidden Markov models with application to ion channel data

Diehn, Manuel 01 November 2017 (has links)
No description available.

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