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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.
191

Laboratory and modelling studies on the effects of injection gas composition on CO₂-rich flooding in Cooper Basin, South Australia.

Bon, Johannes January 2009 (has links)
This Ph.D. research project targets Cooper Basin oil reservoirs of very low permeability (approximately 1mD) where injectivities required for water flooding are not achievable. However, the use of injection gases such as CO₂ would not have injectivity problems. CO₂ is abundant in the region and available for EOR use. CO₂ was compared to other CO₂-rich injection gases with a hydrocarbon content including pentane plus components. While the effect of hydrocarbon components up to butane have been investigated in the past, the effect of n-pentane has on impure CO₂ gas streams has not. One particular field of the Cooper Basin was investigated in detail (Field A). However, since similar reservoir and fluid characteristics of Field A are common to the region it is expected that the data measured and developed has applications to many other oil reservoirs of the region and similar reservoirs elsewhere. The aim of this Ph.D. project is to determine the applicability of CO₂ as an injection gas for Enhanced Oil Recovery (EOR) in the Cooper Basin oil reservoirs and to compare CO₂ with other possible CO₂-rich injection gases. The summarised goals of this research are to: • Determine the compatibility of Field A reservoir fluid with CO₂ as an injection gas. • Compare CO₂ to other injection gas options for Field A. • Development of a correlation to predict the effect of nC₅ on MMP for a CO₂- rich injection gas stream. These goals were achieved through the following work: • Extensive experimental studies of the reservoir properties and the effects of interaction between CO₂-rich injection gas streams and Field A reservoir fluid measuring properties related to: • Miscibility of the injection gas with Field A reservoir fluid • Solubility and swelling properties of the injection gas with Field A reservoir fluid • Change in viscosity-pressure relationship of Field A reservoir fluid due to addition of injection gas • A reservoir condition core flood experiment • Compositional simulation of the reservoir condition core flood to compare expected recoveries from different injection gases • Development of a set of Minimum Miscibility Pressure (MMP) measurements targeted at correlating the effect of nC₅ on CO₂ MMP. The key findings of this research are as follows: • Miscibility is achievable at practical pressures for Field A and similar reservoir fluids with pure CO₂ or CO₂-rich injection gases. • For Field A reservoir fluid, viscosity of the remaining flashed liquid will increase at pressures below ~2500psi due to mixing the reservoir fluid with a CO₂-rich injection gas stream. • Comparison of injection gases showed that methane rich gases are miscible with Field A so long as a significant quantity of C₃+ components is also present in the gas stream. • There is a defined trend for effect of nC₅ on MMP of impure CO₂. This trend was correlated with an error of less than 4%. • Even though oil composition is taken into account with the base gas MMP, it still affects the trend for effect of nC₅ on MMP of a CO₂-rich gas stream. • An oil characterisation factor was developed to account for this effect, significantly improving the results, reducing the error of the correlation to only 1.6%. The significance of these findings is as follows: • An injection pressure above ~3000psi should be targeted. At these pressures miscibility is achieved and the viscosity of the reservoir fluid injection gas mix is reduced. • CO₂ should be compared to gases such as Tim Gas should after considering the cost of compression, pipeline costs and distance from source to destination will need to be considered. • The addition of nC₅ will reduce the MMP and increase the recovery factor, however the cost of the nC₅ used would be more than the value of increased oil recovered. • The developed correlation for the effect of nC₅ on impure CO₂ MMP can be used broadly within the limits of the correlation. • Further research using more oils is necessary to validate the developed oil characterisation factor and if successful, using the same or similar method used to improve other correlations. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1369016 / Thesis (Ph.D.) -- University of Adelaide, Australian School of Petroleum, 2009.
192

Couplage variable entre un qubit de charge et un qubit de phase

Fay, Aurélien 09 June 2008 (has links) (PDF)
Nous avons étudié la dynamique quantique d'un circuit supraconducteur constitué d'un SQUID dc couplé à un transistor à paires de Cooper fortement asymétrique (ACPT). Le SQUID dc est un qubit de phase contrôlé par un courant de polarisation et un champ magnétique. L'ACPT est un qubit de charge contrôlé par un courant de polarisation, un champ magnétique et une tension de la grille.<br /><br />Nous avons mesuré par spectroscopie micro-onde les premiers niveaux d'énergie du circuit couplé en fonction des paramètres de contrôle. Les mesures des états quantiques des qubits de charge et de phase sont réalisées par une mesure d'échappement du SQUID dc avec une impulsion de flux nanoseconde appliquée dans celui-ci. La mesure de l'ACPT utilise un nouveau processus quantique : l'état excité de l'ACPT est transféré adiabatiquement vers l'état excité du SQUID durant l'impulsion de flux.<br /><br />Notre circuit permet de manipuler indépendamment chaque qubit tout comme il permet d'intriquer les états quantiques des deux circuits. Nous avons observé des anti-croisements des niveaux d'énergie des deux qubits lorsqu'ils sont mis en résonance. Le couplage a été mesuré sur une large gamme de fréquence, pouvant varier de 60 MHz à 1.1 GHz. Nous avons réussi à obtenir un couplage variable entre le qubit de charge et le qubit de phase. Nous avons analysé théoriquement la dynamique quantique de notre circuit. Cette analyse a permis de bien expliquer le couplage variable mesuré par une combinaison entre un couplage Josephson et un couplage capacitif entre les deux qubits.
193

La pompe à paire de Cooper, un read-out pour le Qubit Josephson

Schaeffer, David 07 November 2005 (has links) (PDF)
La double île supraconductrice, composée de trois jonctions Josephson en série, est un circuit pouvant<br />se comporter comme un système à deux niveaux. Les énergies des états quantiques macroscopiques sont<br />contrôlées par deux tensions de grille et par une tension de polarisation VB.<br />Le transfert d'une paire de Cooper à travers le circuit dissipe dans l'environnement électromagnétique<br />une quantité d'énergie 2eVB, correspondant à la polarisation en tension. Les propriétés de transport<br />à travers ce dispositif, en absence de quasiparticules résiduelles, font apparaître la compétition entre le<br />couplage des états dégénérés de la double île et le taux de relaxation en fonction de la tension de<br />polarisation. Tant que la relaxation est le facteur limitant, le courant est uniquement déterminé par la<br />relaxation, conduisant au régime quantique. Par contre, si le couplage devient le facteur limitant (ou<br />si la relaxation domine), la dynamique change et le courant paradoxalement diminue, menant au<br />régime Zéno. Aux tensions suffisamment basses, le supercourant est identifié à travers les trois jonctions<br />en série.<br />Dans ce travail, il s'agit aussi de comprendre l'effet d'un cycle d'évolution adiabatique, réalisé par<br />l'application des deux tensions de grille alternatives de même fréquence et d'amplitude en quadrature de<br />phase, produisant un courant de pompage à travers le circuit. Cette thèse présente dans quelle mesure<br />le pompage adiabatique peut être exploité pour "lire" l'état du système. Le courant de pompage est, en<br />effet, sensible à l'occupation de l'état quantique, la charge pompée dans l'état fondamental et dans le<br />premier état excité étant de signe opposé.
194

Tytoglasses : Ett designförslag på glasögonbågar med implementerad LED-belysning

Carlsson, Pontus January 2009 (has links)
<p>Företaget Multilens tillverkar glasögon med förstoringsoptik för personer med kraftigt nedsatt syn och stort behov av mer ljus när de läser. Det finns hjälpmedel som förstoringsglas, men med dagens LED-teknik vill Multilens undersöka möjligheten att tillverka glasögonbågar med LED-teknik implementerad i bågarna.  Detta projekt har genom designmetoderna Personas, Scenarios och Quality Function Deployment undersökt vilka funktioner ett par glasögonbågar med implementerad LED-teknik ska innehålla för att personer med behov av den sortens hjälpmedel ska kunna använda dem. Resultatet blev ett antal funktioner på Tytoglasses i form av kravspecifikationer. Tytoglasses har sedan visualiserats i form av en tredimensionell modell.  Denna tredimensionella modell illustrerar hur de olika funktionerna implementerats på glasögonbågarna och hur de är tänkta att fungera.</p>
195

The Nation Conceived : Learning, Education, and Nationhood in American Historical Novels of the 1820s

McElwee, Johanna January 2005 (has links)
<p>This study explores the role of learning and education in American historical fiction written in the 1820s. The United States has been, and still is, commonly considered to be hostile to scholarly learning. In novels and short stories of the 1820s, however, learning and education are recurrent themes, and this dissertation shows that the attitudes to these issues are more ambivalent than hitherto acknowledged. The 1820s was a period characterized by a political struggle, expressed as a battle between intellectuals, represented by the sitting president, John Quincy Adams, a Harvard professor, and anti-intellectuals, headed by the war hero Andrew Jackson. The battle over the place of scholarly learning in the U.S. was played out not only on the political scene but also in historical fiction, where the themes of learning and education become vehicles for exploring national identity. In these texts, whose aim is often to establish an impressive national history, scholarly learning carries negative connotations as it is linked to the former colonizer Britain and also symbolizes social stratification. However, it also stands for civilization and progress, qualities felt to be necessary for the nation to come into its own. The conflicting views and anxieties surrounding the issues of learning and education tend to center on a recurrent character in these texts, the learned person. </p><p>After providing an overview of how the themes of learning and education are treated in historical narratives from the 1820s, this dissertation focuses on works of three writers: <i>Hobomok</i> (1824) and <i>The Rebels</i> (1825) by Lydia Maria Child, <i>The Prairie</i> (1827) by James Fenimore Cooper, and <i>Hope Leslie</i> (1827) by Catharine Maria Sedgwick.</p>
196

Isomerism and C-H, C-C, O-O, C-O bond activation studies by transition metals

Poater Teixidor, Albert 24 April 2006 (has links)
Aquesta tesi és el reflex que de la cooperació entre grups experimentals i grups teòrics s'aconsegueix l'assoliment d'objectius inassolibles de forma individual. A partir de la DFT s'expliquen processos inorgànics i organometàl·lics de gran valor biològic i/o industrial. La tesi està enfocada especialment a l'estudi de complexos mononuclears i binuclears de coure, on té lloc l'activació d'enllaços C-H, C-C, i O-O. L'estudi de complexos octaèdrics de ruteni ha permès dur a terme extensos estudis isomèrics i racionalitzar les propietats espectroscòpiques dels mateixos. A més a més, estudis més puntuals respecte clusters de coure, l'estudi de la reacció de Pawson-Khand, l'estudi d'enllaços Pt-Pt en complexos trimèrics de platí, a més a més de l'estudi de la isomeria de complexos de Ni i Pt. / This thesis shows that the cooperation between experimental and theoretical groups gives as a result the achievement of aims impossible working independently. From DFT calculations inorganic and organometallic problems related to great biological and industrial processes can be explained. This thesis is especially focused on the study of mononuclear and binuclear copper complexes, where a C-H, C-C, and O-O bond activation takes place. The study of octahedral ruthenium complexes has allowed carrying out isomeric studies and the rationalization of spectroscopic properties. Furthermore, other little studies related to copper clusters, the Pawson-Khand reaction, Pt-Pt bond interaction in trimer platinum complexes, and isomerism of Ni and Pt complexes.
197

Tytoglasses : Ett designförslag på glasögonbågar med implementerad LED-belysning

Carlsson, Pontus January 2009 (has links)
Företaget Multilens tillverkar glasögon med förstoringsoptik för personer med kraftigt nedsatt syn och stort behov av mer ljus när de läser. Det finns hjälpmedel som förstoringsglas, men med dagens LED-teknik vill Multilens undersöka möjligheten att tillverka glasögonbågar med LED-teknik implementerad i bågarna.  Detta projekt har genom designmetoderna Personas, Scenarios och Quality Function Deployment undersökt vilka funktioner ett par glasögonbågar med implementerad LED-teknik ska innehålla för att personer med behov av den sortens hjälpmedel ska kunna använda dem. Resultatet blev ett antal funktioner på Tytoglasses i form av kravspecifikationer. Tytoglasses har sedan visualiserats i form av en tredimensionell modell.  Denna tredimensionella modell illustrerar hur de olika funktionerna implementerats på glasögonbågarna och hur de är tänkta att fungera.
198

Strongly spin-polarized current generated in a Zeeman-split unconventional superconductor

Linder, Jacob, Yokoyama, Takehito, Tanaka, Yukio, Sudbø, Asle 07 1900 (has links)
No description available.
199

Blackening Character, Imagining Race, and Mapping Morality: Tarring and Feathering in Nineteenth Century American Literature

Trninic, Marina 16 December 2013 (has links)
This study examines the ritual of tarring and feathering within specific American cultural contexts and literary works of the nineteenth-century to show how the discourse surrounding the actual and figurative practice functioned as part of a larger process of discursive and visual racialization. The study illustrates how the practice and discourse of blackening white bodies enforced embodiment, stigmatized imagined interiority, and divorced the victims from inalienable rights. To be tarred and feathered was to be marked as anti-social, duplicitous and even anarchic. The study examines the works of major American authors including John Trumbull, James Fenimore Cooper, Edgar Allan Poe, and Nathaniel Hawthorne, analyzing how their works evidence a larger national conflation of character, race, and morality. Sometimes drawing on racial imagery implicitly, and sometimes engaging in the issues of race and slavery explicitly, their works feature tarring and feathering to portray their anxieties about social coercion and victimization in the context of the “experiment” of democracy. Trumbull’s mock-epic genre satirizes the plight of the Tory and diminishes the forms of the revolution; Cooper’s novel works as a rhetorical vehicle to prevent a perceived downfall of the republic; the short fiction of Poe exaggerates the horror of uneven and racialized power relations; and Hawthorne’s body of work ironizes the original parody of tar and feathers to expose the violent nature of democratic foundation. Relying on an interdisciplinary approach, this first, in-depth study of tarring and feathering in America reveals that the ritual is a fertile ground for understanding the multivalent social constructs of the time. Examining tarring and feathering incidents can tell scholars about the status of racial feeling, moral values (including sexual and gender norms), and economic fissures of the context in which they occur. Abjecting the body of the victim, the act rewrites the individual’s relationship to the body politic, and the performance of the ritual reveals the continuously emergent, publically sanctioned forms of belonging to the community and the nation. Moreover, examining the representation of tarring and feathering can tell scholars about an author’s relationship to the ideology of an American way.
200

Hybridity in Cooper, Mitchell and Randall : erasures, rewritings, and American historical mythology

Thormodsgard, Marie January 2004 (has links)
This thesis starts with an overview of the historical record tied to the birth of a new nation studied by Alexis de Tocqueville and Henry Steele Commager. It singles out the works of Henry Nash Smith and Eugene D. Genovese for an understanding, respectively, of the "myth of the frontier" tied to the conquest of the American West and the "plantation myth" that sustained slavery in the American South. Both myths underlie the concept of hybridity or cross-cultural relations in America. This thesis is concerned with the representation or lack of representation of hybridity and the roles played by female characters in connection with the land in two seminal American novels and their film versions---James Fenimore Cooper's The Last of the Mohicans, and Margaret Mitchell's Gone With the Wind---and Alice Randall's rewriting of Mitchell's novel, The Wind Done Gone , as a point of contrast. Hybridity is represented in the mixed-race bodies of these characters.

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