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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.
151

Botswana & Zimbabwe : En komparativ demokratiseringsstudie

Kungberg, Marcus January 2017 (has links)
Abstract The purpose of this essay is to shed light on why the democratic developments in Botswana and Zimbabwe, despite their many similarities, have gone in very different directions. By the time of their respective independence, both countries proclaimed themselves democratic states. However, only Botswana succeeded in the transition, while Zimbabwe soon fell back into an autocratic regime. The method used is a comparative case study. By comparing the cases Botswana and Zimbabwe in according to five selected democratic variables, this method makes it possible to explain why only Botswana succeeded. The research questions are: How have Botswana’s and Zimbabwe’s respective democratic transitions happened? What factors have influenced and guided the direction of the democratic development in Botswana and Zimbabwe? The following democratic variables will guide the comparison: “Economic development”, “Market economy”, “Strong middleclass”, “External influences” and “Political leaders dedicated to democracy”.                 The results show considerable differences between the democratic transitions of Botswana and Zimbabwe as regards all the selected democratic variables. The comparative method thus proved to be an effective tool to explain the democratic development in the two countries investigated in this case study. However, these factors potentially just scratch the surface and, in a theory-developing spirit, more democratic factors can broaden the explanation even more.
152

OBSERVATION AND CONFIRMATION OF SIX STRONG-LENSING SYSTEMS IN THE DARK ENERGY SURVEY SCIENCE VERIFICATION DATA

Nord, B., Buckley-Geer, E., Lin, H., Diehl, H. T., Helsby, J., Kuropatkin, N., Amara, A., Collett, T., Allam, S., Caminha, G. B., De Bom, C., Desai, S., Dúmet-Montoya, H., da S. Pereira, M. Elidaiana, Finley, D. A., Flaugher, B., Furlanetto, C., Gaitsch, H., Gill, M., Merritt, K. W., More, A., Tucker, D., Saro, A., Rykoff, E. S., Rozo, E., Birrer, S., Abdalla, F. B., Agnello, A., Auger, M., Brunner, R. J., Kind, M. Carrasco, Castander, F. J., Cunha, C. E., da Costa, L. N., Foley, R. J., Gerdes, D. W., Glazebrook, K., Gschwend, J., Hartley, W., Kessler, R., Lagattuta, D., Lewis, G., Maia, M. A. G., Makler, M., Menanteau, F., Niernberg, A., Scolnic, D., Vieira, J. D., Gramillano, R., Abbott, T. M. C., Banerji, M., Benoit-Lévy, A., Brooks, D., Burke, D. L., Capozzi, D., Rosell, A. Carnero, Carretero, J., D’Andrea, C. B., Dietrich, J. P., Doel, P., Evrard, A. E., Frieman, J., Gaztanaga, E., Gruen, D., Honscheid, K., James, D. J., Kuehn, K., Li, T. S., Lima, M., Marshall, J. L., Martini, P., Melchior, P., Miquel, R., Neilsen, E., Nichol, R. C., Ogando, R., Plazas, A. A., Romer, A. K., Sako, M., Sanchez, E., Scarpine, V., Schubnell, M., Sevilla-Noarbe, I., Smith, R. C., Soares-Santos, M., Sobreira, F., Suchyta, E., Swanson, M. E. C., Tarle, G., Thaler, J., Walker, A. R., Wester, W., Zhang, Y. 05 August 2016 (has links)
We report the observation and confirmation of the first group-and cluster-scale strong gravitational lensing systems found in Dark Energy Survey data. Through visual inspection of data from the Science Verification season, we identified 53 candidate systems. We then obtained spectroscopic follow-up of 21 candidates using the Gemini Multi-object Spectrograph at the Gemini South telescope and the Inamori-Magellan Areal Camera and Spectrograph at the Magellan/Baade telescope. With this follow-up, we confirmed six candidates as gravitational lenses: three of the systems are newly discovered, and the remaining three were previously known. Of the 21 observed candidates, the remaining 15 either were not detected in spectroscopic observations, were observed and did not exhibit continuum emission (or spectral features), or were ruled out as lensing systems. The confirmed sample consists of one group-scale and five galaxy-cluster-scale lenses. The lensed sources range in redshift z similar to 0.80-3.2 and in i-band surface brightness i(SB) similar to 23-25 mag arcsec(-2) (2 '' aperture). For each of the six systems, we estimate the Einstein radius theta(E) and the enclosed mass M-enc, which have ranges theta(E) similar to 5 ''-9 '' and M-enc similar to 8 x 10(12) to 6 x 10(13)M(circle dot), respectively.
153

The extraordinary amount of substructure in the Hubble Frontier Fields cluster Abell 2744

Jauzac, M., Eckert, D., Schwinn, J., Harvey, D., Baugh, C. M., Robertson, A., Bose, S., Massey, R., Owers, M., Ebeling, H., Shan, H. Y., Jullo, E., Kneib, J.-P., Richard, J., Atek, H., Clément, B., Egami, E., Israel, H., Knowles, K., Limousin, M., Natarajan, P., Rexroth, M., Taylor, P., Tchernin, C. 21 December 2016 (has links)
We present a joint optical/X-ray analysis of the massive galaxy cluster Abell 2744 (z = 0.308). Our strong- and weak-lensing analysis within the central region of the cluster, i.e. at R < 1 Mpc from the brightest cluster galaxy, reveals eight substructures, including the main core. All of these dark matter haloes are detected with a significance of at least 5 sigma and feature masses ranging from 0.5 to 1.4 x 10(14) M-circle dot within R < 150 kpc. Merten et al. and Medezinski et al. substructures are also detected by us. We measure a slightly higher mass for the main core component than reported previously and attribute the discrepancy to the inclusion of our tightly constrained strong-lensing mass model built on Hubble Frontier Fields data. X-ray data obtained by XMM-Newton reveal four remnant cores, one of them a new detection, and three shocks. Unlike Merten et al., we find all cores to have both dark and luminous counterparts. A comparison with clusters of similar mass in the Millennium XXL simulations yields no objects with as many massive substructures as observed in Abell 2744, confirming that Abell 2744 is an extreme system. We stress that these properties still do not constitute a challenge to Lambda cold dark matter, as caveats apply to both the simulation and the observations: for instance, the projected mass measurements from gravitational lensing and the limited resolution of the subhaloes finders. We discuss implications of Abell 2744 for the plausibility of different dark matter candidates and, finally, measure a new upper limit on the self-interaction cross-section of dark matter of sigma(DM) < 1.28 cm(2) g(-1) (68 per cent CL), in good agreement with previous results from Harvey et al.
154

Retrospective Perceptions of Early Parent-Child Relations and Occupational Orientation

Smith, Richard E. 12 1900 (has links)
The purpose of the present study was to examine the relationship between early perceptions of parent-child relations, as measured by the Roe and Siegelman Parent-Child Relations Questionnaire (PCR), and the occupational orientation of the child, as measured by the Strong Vocational Interest Blank (SVIB).
155

High Lyman Continuum Escape Fraction in a Lensed Young Compact Dwarf Galaxy at z=2.5

Bian, Fuyan, Fan, Xiaohui, McGreer, Ian, Cai, Zheng, Jiang, Linhua 02 March 2017 (has links)
We present the HST WFC3/F275W UV imaging observations of A2218-Flanking, a lensed compact dwarf galaxy at redshift z approximate to 2.5. The stellar mass of A2218-Flanking is log(M-*/M-circle dot) = 9.14(-0.04)(+0.07) and SFR is 12.5(-7.4)(+3.8) M-circle dot yr(-1) after correcting the magnification. This galaxy has a young galaxy age of 127. Myr and a compact galaxy size of r(1/2) = 2.4 kpc. The HST UV imaging observations cover the rest-frame Lyman continuum (LyC) emission (similar to 800 angstrom) from A2218-Flanking. We firmly detect (14s) the LyC emission in A2218-Flanking in the F275W image. Together with the HST F606W images, we find that the absolute escape fraction of LyC is f(abs,esc) > 28%-57% based on the flux density ratio between 1700 and 800 angstrom (f(1700)/f(800)). The morphology of the LyC emission in the F275W images is extended and follows the morphology of the UV continuum morphology in the F606W images, suggesting that the f(800) is not from foreground contaminants. We find that the region with a high star formation rate surface density has a lower f(1700)/f(800) (higher f(800)/f(1700)) ratio than the diffused regions, suggesting that LyC photons are more likely to escape from the region with the intensive star-forming process. We compare the properties of galaxies with and without LyC detections and find that LyC photons are easier to escape in low-mass galaxies.
156

Structure Determination and Prediction of Zeolites : A Combined Study by Electron Diffraction, Powder X-Ray Diffraction and Database Mining

Guo, Peng January 2016 (has links)
Zeolites are crystalline microporous aluminosilicates with well-defined cavities or channels of molecular dimensions. They are widely used for applications such as gas adsorption, gas storage, ion exchange and catalysis. The size of the pore opening allows zeolites to be categorized into small, medium, large and extra-large pore zeolites. A typical zeolite is the small pore silicoaluminophosphate SAPO-34, which is an important catalyst in the MTO (methanol-to-olefin) process. The properties of zeolite catalysts are determined mainly by their structures, and it is therefore important to know the structures of these materials in order to understand their properties and explore new applications. Single crystal X-ray diffraction has been the main technique used to determine the structures of unknown crystalline materials such as zeolites. This technique, however, can be used only if crystals larger than several micrometres are available. Powder X-ray diffraction (PXRD) is an alternative technique to determine the structures if only small crystals are available. However, peak overlap, poor crystallinity and the presence of impurities hinder the solution of structures from PXRD data. Electron crystallography can overcome these problems. We have developed a new method, which we have called “rotation electron diffraction” (RED), for the automated collection and processing of three-dimensional electron diffraction data. This thesis describes how the RED method has been applied to determine the structures of several zeolites and zeolite-related materials. These include two interlayer expanded silicates (COE-3 and COE-4), a new layered zeolitic fluoroaluminophosphate (EMM-9), a new borosilicate (EMM-26), and an aluminosilicate (ZSM-25). We have developed a new approach based on strong reflections, and used it to determine the structure of ZSM-25, and to predict the structures of a series of complex zeolites in the RHO family. We propose a new structural principle that describes a series of structurally related zeolites known as “embedded isoreticular zeolite structures”, which have expanding unit cells. The thesis also summarizes several common structural features of zeolites in the Database of Zeolite Structures. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 3: Manuscript.</p>
157

Does a pint a day affect your child’s pay? : Prenatal alcohol exposure and child outcomes, Evidence from a policy experiment

Olsson, Thomas January 2007 (has links)
In this thesis I evaluate the impact of an experiment with free sales of strong beer in two Swedish counties that took place in the 1960s. I do this by studying adult earnings of persons in utero during the experiment. My data includes date and place of birth and allows me to evaluate the impact of the experiment using a difference-in differences methodology, comparing earnings across cohorts and counties. Since the availability of alcohol increased most heavily for persons under the age of 21, and male fetuses are less physiologically robust than female fetuses, I choose to study persons born by mothers younger than 21 separately and also estimate the impact of the experiment separately for men and women. I find that persons born by mothers under the age of 21 during the experiment have lower average earnings than persons born before the experiment, and that the impact is larger on men. My results indicate that the experiment has led to adverse effects on adult earnings, probably caused by the prenatal alcohol exposure’s negative impact on fetal development. This means that alcohol consumption have long-term consequences that represent large costs to society. Since these costs are generally disregarded when evaluating the cost of alcohol consumption, society’s cost of alcohol is probably higher than usually estimated.
158

Modélisation des pales d'éoliennes ou d'hydroliennes en environnement naturel à l'aide d'un code fluide-structure / Fluid-structure interaction on wind turbine blades

Lothodé, Corentin 24 September 2018 (has links)
Ce travail porte sur la mise en œuvre de simulations sur des pales de machines tournantes. Une première partie de la thèse porte sur l’amélioration des performances du couplage fluide-structure. Des nouveaux algorithmes sont présentés. Une nouvelle méthode de déformation de maillage est évaluée. Les développements sont validés à partir de plusieurs cas tests. La deuxième partie porte sur l’application des avancées à des machines tournantes. Une première validation est faite sur une hydrolienne. La vibration d’une pale au passage du mat est étudiée. Enfin, des résultats sur une hydrolienne industrielle sont exposés. / A methodology to simulate blades of turbines is developed. A first part is dedicated to improving the performance of the fluid-structure coupling. New algorithms are presented. A new mesh morphing solution is shown. Developments are validated on many test cases. A second part is dedicated to applying the developments on turbines. A first validation is made on a water turbine. The vibration of a blade interacting with a mast is studied. Finally, some results of an industrial water turbine are shown.
159

More Than Artifacts: The Surprising Importance of Census Designated Places

Dhavale, Dawn Maya 20 August 2004 (has links)
CDPs are an overlooked component of the metropolitan region, and add to the understanding of the region as a whole. Large CDPs that remain unincorporated have other forms of governance, either public or private. CDPs are equivalent to incorporated places in many ways, but have distinctive differences based on state and region. Large CDPs have reasons for not incorporating. A subset of these CDPs that are similar to Boomburbs are examined. Implications for planners regarding CDP existence are discussed. / Master of Urban and Regional Planning
160

Phases désordonnées dans des gaz d'atomes froids de basse dimensionnalité / Disordered phases in low dimensional ultra-cold atomic gases.

Crépin, François 28 September 2011 (has links)
Cette thèse aborde deux problèmes ayant trait à la physique des gaz quantiques de basse dimensionnalité. Le premier système étudié est un mélange unidimensionnel de bosons et de fermions sans spin soumis à un potentiel aléatoire. Nous commençons par écrire un Hamiltonien de basse énergie et abordons la question de la localisation du point de vue de l'accrochage des ondes de densité par un désordre faible. En utilisant le Groupe de Renormalisation et une méthode variationnelle dans l'espace des répliques, le diagramme de phase peut être tracé en fonctions de deux paramètres : la force des interactions Bose-Bose et Bose-Fermi. La position et les propriétés des phases dépendent d'un paramètre additionnel, le rapport des vitesses du son de chaque composante du gaz. Quelque soit la valeur de ce rapport nous trouvons trois phases, (i) une phase totalement délocalisée, le liquide de Luttinger à deux composantes, (ii) une phase totalement localisée où les deux composantes sont accrochées par le désordre et (iii) une phase intermédiaire où seuls les fermions sont localisés. Le deuxième système est un gaz de bosons de cœur dur sur un réseau en échelle. Trois paramètres en contrôlent la physique : les amplitudes de saut transverse et longitudinale, et le remplissage. En utilisant plusieurs méthodes analytiques (théorie des perturbations, bosonisation et RG) nous proposons une interprétation de résultats numériques nouveaux obtenus par nos collaborateurs, notamment sur le paramètre de Luttinger du mode symétrique. Nous en déduisons un diagramme de phase en présence de désordre faible. / In this thesis we study two distinct problems related to the physics of quantum gases in one dimension. After writing a low-energy Hamiltonian, we address the question of localization by considering the pinning of density waves by weak disorder. Using the Renormalization Group and a variationnal method in replica space, we find that the phase diagram is adequately plotted as a function of two parameters: the strength of Bose-Bose and Bose-Fermi interactions. The position and properties of the various phases depend on an additional third parameter, the ratio of the phonon velocities of each component of the gas. Whatever the value of this ratio, we identify -- using the Renormalization Group and a variational calculation -- three types of phases, (i) a fully delocalized phase, that is a two-component Luttinger, (ii) a fully localized phase where both components are pinned by disorder and (iii) an intermediate phase where fermions are localized and bosons are superfluid. The second system is a two-leg ladder lattice of hardcore bosons. Three parameters control the physics: transverse and longitudinal tunneling and the filling. Using several analytical methods (perturbation theory, bosonization, RG) we give an interpretation of new numerical results obtained by our collaborators, namely on the Luttinger parameter of the symmetric mode. We deduce a phase diagram for weak disorder.

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