Für das CsI(Tl)-Kalorimeter des Babar-Detektors wurde ein Verfahren zur Kalibration entwickelt und implementiert. Es ist in der Lage, für alle 6580 Kristalle absolute Kalibrationskonstanten zu bestimmen und die zeitliche Änderung der Kristalleigenschaften zu monitorieren. Der Algorithmus basiert auf dem Vergleich von gemessener Energie und erwarteter deponierter Energie von Teilchen aus Ereignissen der Bhabha-Streuung. Die gemessene Energie wird aus einem Cluster von getroffenen Kristallen bestimmt, wobei die Kalibrierung der Einzelkristallenergien durch Multiplikation mit einer Kalibrationskonstante c erfolgt. Die erwartete Energie wird aus einer Monte-Carlo-Simulation extrahiert. Die Minimierung eines chi^2-Terms - in dem erwartete und gemessene Cluster-Energien verglichen werden - bezüglich der Kalibrationskonstanten c, führt zu einem linearen Gleichungssystem mit einer 6580*6580 Matrix, die numerisch invertiert werden kann. Die Methode kalibriert die Kristalle im Energiebereich von 2,5 bis 8 GeV. Bei einer Luminosität von 3*10^33 Ereignissen pro cm^2 und s erlaubt die hohe Rate an Bhabha-Ereignissen am PEP-II-Beschleuniger eine Kalibration mit einer statistischen Genauigkeit von 0,32 % innerhalb von 12 Stunden. Der Einfluss systematischer Unsicherheiten wurde untersucht und zu +0,81% -0,72% abgeschätzt. Durch die Kalibration konnten Energieauflösungen sigma_E / E von 1,8% bei Elektronen mit einer Energie von 7,5 GeV erreicht werden. Im Jahr 2000 wurde von Mitte Mai bis Ende Oktober ein Absinken der Lichtausbeute der Kristalle der Endkappe von etwa 2,8% beobachtet. / A technique to calibrate the CsI(Tl) calorimeter of the Babar experiment was developed and implemented. The method allows a calculation of absolute calibration constants for all 6580 crystals. With these constants, a monitoring of the change of the light yield of the crystals is possible. The algorithm is based on the comparison of the measured energy and the expected deposited energy of particles in Bhabha scattering events. The measured energy is calculated from a cluster of hit crystals. The individual crystal energies are calibrated by a multiplication with a calibration constant c. The expected energy is extracted from a Monte-Carlo-Simulation. Minimizing a chi^2 term - which compares the expected and the measured cluster energies - with respect to the constants c yields a system of linear equations with a 6580x6580 matrix, that can be inverted numerically. The crystals are calibrated in an energy range of 2.5 to 8 GeV. The large rate of Bhabha scattering events at the PEP-II accelerator allows a calibration with a statistical precision of 0.32% within 12 hours of data taking at a luminosity of 3*10^33 events per square centimeter and second. The influence of systematic uncertainties was studied and estimated to be +0.81% -0.72%. Due to the calibration an energy resolution sigma_E / E of 1.8% could be obtained for electrons with an energy of 7.5 GeV. With the calibration constants a decrease in the lightyield of the endcap crystals of 2.8% could be observed between May and October 2000.

Für das CsI(Tl)-Kalorimeter des Babar-Detektors wurde ein Verfahren zur Kalibration entwickelt und implementiert. Es ist in der Lage, für alle 6580 Kristalle absolute Kalibrationskonstanten zu bestimmen und die zeitliche Änderung der Kristalleigenschaften zu monitorieren. Der Algorithmus basiert auf dem Vergleich von gemessener Energie und erwarteter deponierter Energie von Teilchen aus Ereignissen der Bhabha-Streuung. Die gemessene Energie wird aus einem Cluster von getroffenen Kristallen bestimmt, wobei die Kalibrierung der Einzelkristallenergien durch Multiplikation mit einer Kalibrationskonstante c erfolgt. Die erwartete Energie wird aus einer Monte-Carlo-Simulation extrahiert. Die Minimierung eines chi^2-Terms - in dem erwartete und gemessene Cluster-Energien verglichen werden - bezüglich der Kalibrationskonstanten c, führt zu einem linearen Gleichungssystem mit einer 6580*6580 Matrix, die numerisch invertiert werden kann. Die Methode kalibriert die Kristalle im Energiebereich von 2,5 bis 8 GeV. Bei einer Luminosität von 3*10^33 Ereignissen pro cm^2 und s erlaubt die hohe Rate an Bhabha-Ereignissen am PEP-II-Beschleuniger eine Kalibration mit einer statistischen Genauigkeit von 0,32 % innerhalb von 12 Stunden. Der Einfluss systematischer Unsicherheiten wurde untersucht und zu +0,81% -0,72% abgeschätzt. Durch die Kalibration konnten Energieauflösungen sigma_E / E von 1,8% bei Elektronen mit einer Energie von 7,5 GeV erreicht werden. Im Jahr 2000 wurde von Mitte Mai bis Ende Oktober ein Absinken der Lichtausbeute der Kristalle der Endkappe von etwa 2,8% beobachtet. / A technique to calibrate the CsI(Tl) calorimeter of the Babar experiment was developed and implemented. The method allows a calculation of absolute calibration constants for all 6580 crystals. With these constants, a monitoring of the change of the light yield of the crystals is possible. The algorithm is based on the comparison of the measured energy and the expected deposited energy of particles in Bhabha scattering events. The measured energy is calculated from a cluster of hit crystals. The individual crystal energies are calibrated by a multiplication with a calibration constant c. The expected energy is extracted from a Monte-Carlo-Simulation. Minimizing a chi^2 term - which compares the expected and the measured cluster energies - with respect to the constants c yields a system of linear equations with a 6580x6580 matrix, that can be inverted numerically. The crystals are calibrated in an energy range of 2.5 to 8 GeV. The large rate of Bhabha scattering events at the PEP-II accelerator allows a calibration with a statistical precision of 0.32% within 12 hours of data taking at a luminosity of 3*10^33 events per square centimeter and second. The influence of systematic uncertainties was studied and estimated to be +0.81% -0.72%. Due to the calibration an energy resolution sigma_E / E of 1.8% could be obtained for electrons with an energy of 7.5 GeV. With the calibration constants a decrease in the lightyield of the endcap crystals of 2.8% could be observed between May and October 2000.

The protagonist Martha in Doris Lessing’s Martha Quest is born to white British settler parents and grows up in a British colony in southern Africa in the 1930s. Although officially the coloniser rather than the colonised, Martha tries to reject this role mentally, verbally, and physically. This essay aims to show that a postcolonial reading of Martha in relation to the colonial context helps in understanding her double consciousness and, more specifically, her inability to find a real or lasting sense of home. Using Homi Bhabha’s concept of unhomeliness, the essay argues that Martha does not truly feel at home anywhere, because the “unhomely” always disturbs the “homely.” Through close reading of the text, it shows how Martha tries to find a sense of home in four areas of her life: her physical home, nature, her body, and her mind. This essay finds that despite Martha’s efforts in moving from her family home to rented accommodation, from the bush to the city, from girlhood to womanhood, and from her individual thoughts to the solidarity of others, she still does not feel at home anywhere. Whenever she starts to feel comfortable in a place or situation, unhomely moments, such as reminders of her nationality, race, or class, always disturb the homely feelings of belonging. Ultimately, Martha cannot escape her unhomeliness. / Huvudpersonen Martha i Doris Lessings Martha Quest är dotter till vita brittiska bosättare och växer upp i en brittisk koloni i södra Afrika på 1930-talet. Trots att hon formellt sett är kolonisatören snarare än den koloniserade, försöker Martha att avvisa denna roll mentalt, verbalt och fysiskt. Denna uppsats syftar till att visa att en postkolonial tolkning av Martha i förhållande till det koloniala sammanhanget bidrar till en förståelse av hennes dubbla medvetande och mer specifikt hennes oförmåga att hitta en verklig, eller bestående, känsla av hemma. Med hjälp av Homi Bhabhas koncept gällande o-hemlikhet argumenterar uppsatsen för att Martha inte känner sig riktigt hemma någonstans, eftersom det ”o-hemlika” alltid stör det ”hemlika.” Genom en noggrann läsning av texten visar den hur Martha försöker hitta känslan av ett hem inom fyra områden av sitt liv: sitt fysiska hem, naturen, sin kropp och sitt sinne. Denna uppsats konstaterar att trots Marthas ansträngningar att flytta från sitt familjehem till ett hyresrum, från land till stad, från ung flicka till kvinna och från sina individuella tankar till solidaritet med andra, känner hon sig fortfarande inte hemma någonstans. När hon börjar känna sig bekväm på ett ställe eller i ett läge, stör o-hemlika ögonblick i form av påminnelser om hennes nationalitet, ras eller klass alltid hennes hemlika känslor av tillhörighet. I slutändan kan Martha inte undgå sin o-hemlikhet.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-02-20T12:18:55Z No. of bitstreams: 1 tatianadasilvafalcaocosta.pdf: 666906 bytes, checksum: 4e3c3b9e2476393dca49dc15ee9f2665 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-02-20T17:59:33Z (GMT) No. of bitstreams: 1 tatianadasilvafalcaocosta.pdf: 666906 bytes, checksum: 4e3c3b9e2476393dca49dc15ee9f2665 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-02-20T18:08:19Z (GMT) No. of bitstreams: 1 tatianadasilvafalcaocosta.pdf: 666906 bytes, checksum: 4e3c3b9e2476393dca49dc15ee9f2665 (MD5) / Made available in DSpace on 2017-02-20T18:08:19Z (GMT). No. of bitstreams: 1 tatianadasilvafalcaocosta.pdf: 666906 bytes, checksum: 4e3c3b9e2476393dca49dc15ee9f2665 (MD5) Previous issue date: 2008-12-08 / Esta pesquisa procura compreender como se dá a percepção do mundo sob a perspectiva contemporânea. A via de acesso a esta percepção é a poesia do mineiro de Pirapetinga, Fernando Fábio Fiorese Furtado. Pretendemos i) ampliar nossos questionamentos sobre a atuação da poesia contemporânea na elaboração identitária individual (a priori) e a coletiva (a posteriori), ii) traçar um perfil da percepção contemporânea do mundo através desta poética do enconto. Para nós a construção identitária se dá sempre em relação. / This research looks for getting a better comprehension about a contemporary perception of the world through Fernando Fiorese’s poetry. He is a contemporary Brazilian poet from Pirapetinga, Minas Gerais. We intend i) to enlarge the possibilities of questions related to contemporary poetry performance in working out both individual identity (a priori) and colletive one (a posteriori); ii) to outline a contemporary perception of the world through this meeting poetry. We believe that the identity construction happens always in relation.

SuperKEKB est un collisionneur à très haute luminosité construit pour l’expérience Belle II, constitué d’un anneau de basse énergie (LER) transportant des positrons de 4 GeV et d’un anneau de haute énergie (HER) où circulent des électrons de 7 GeV. Sa mise en service -ou commissioning- se déroulera en trois phases : La phase 1, durant laquelle des faisceaux circulent sans être focalisés au point de collision, a pour but de nettoyer la chambre à vide du gaz résiduel. La seconde phase, où le détecteur Belle II sera en partie installé, permettra le réglage du système de focalisation finale des faisceaux, jusqu’à atteindre une luminosité de 10³⁴ cm⁻² s⁻¹. La troisième phase correspondra au démarrage de l’expérience Belle II avec une luminosité visée de 10³⁵ cm⁻² s⁻¹ à 8×10³⁵ cm⁻² s⁻¹. Dans ce cadre, ma thèse porte sur la conception et la mise en place d’un système permettant le monitorage rapide de la luminosité, système nécessaire pour pouvoir corriger en temps réel les instabilités des faisceaux et ainsi maintenir une luminosité optimale. Afin d’atteindre la haute précision relative souhaitée, de l’ordre de 10⁻³ en 1 ms, la mesure sera basée sur le taux de comptage des particules issues de la diffusion Bhabha radiative à angle nul, processus bien connu et dont la section efficace est importante. Ces particules seront détectées au moyen d’un capteur en diamant, matériau résistant aux radiations et permettant une acquisition très rapide du signal, situé à l’extérieur de la chambre à vide et en aval du point d’interaction. La première partie de cette thèse est consacrée à la recherche des localisations optimales pour le positionnement des capteurs diamants dans chacun des deux anneaux. Au moyen de simulations détaillées, nous avons étudié la dynamique des particules Bhabha lors de leur transport dans les anneaux ainsi que leur interaction avec la matière de la chambre à vide. Ces études ont permis d’ une part d’ identifier un emplacement à 11.9m dans le LER et un autre à 30 m dans le HER, et d’autre part de redéfinir pour l’une d’ entre elle la géométrie locale du tube à vide. La seconde partie, plus expérimentale, s’articule autour de la première phase du commissioning de SuperKEKB et des mesures réalisées au moyen des capteurs diamants que nous avons installés. Dans un premier temps, une étude détaillée des processus de perte single beam (Bremsstrahlung, effet Touschek, diffusion coulombienne) a été réalisée pour le LER en fonction des paramètres du faisceau et du collisionneur (courant, pression, taille transverse des faisceaux). Dans un deuxième temps les résultats de cette étude ont été comparés aux données que nous avons prises de février à juin 2016. Nous avons pu mettre en évidence un bon accord qualitatif et quantitatif entre nos simulations et nos mesures. Cela nous a permis d’estimer que le niveau de bruit de fond attendu dans le cadre des mesures pour le monitorage de la luminosité sera de plus de deux ordres de grandeurs inférieurs au taux du processus Bhabha radiatif à angle nul. / SuperKEKB is a very high luminosity collider dedicated to the Belle II experiment, it consists of a Low Energy Ring (LER) of 4 GeV positrons and a High Energy Ring (HER) of 7 GeV electrons. The commissioning of this machine is split into three phases: phase 1 (single-beam phase) is dedicated to vacuum scrubbing, where beams circulate without focusing at the collision point. Phase 2, for which the major part of the Belle II detector will be installed, will enable the tuning of the final focus system to achieve a luminosity of 10³⁴ cm⁻² s⁻¹. During phase 3, Belle II physics runs will start with an aimed luminosity up to 8×10³⁵ cm⁻² s⁻¹. In this context, the aim of my thesis is to develop and install a fast luminosity monitoring system, which is required for online correction of beam instabilities and maintenance of optimal luminosity. To reach the aimed relative precision of 10⁻³ in 1 ms, the measurement will be based on the radiative Bhabha process at zero photon scattering angle, whose cross-section is large and well-known. These particles will be detected using diamond sensors, resistant to radiation and enabling very fast signal acquisition, to be placed outside of the beam-pipe and downstream of the interaction point. The first part of this work is dedicated to the investigation of the best locations for the diamond sensor positioning in both rings. Using detailed simulations, we studied the dynamics of Bhabha particles during their tracking in the rings and their interaction with the beam pipe material. This led to the identification of two positions, at 11.9 m in LER and at 30 m in HER, and to considering a new geometry for the vacuum pipe in the LER. The second part is related to the phase 1 of the SuperKEKB commissioning and concerns the measurements performed with the diamond sensors that were installed. Single beam loss processes (Bremsstrahlung, Touschek, beam-gas Coulomb scattering) were studied in detail with respect to the LER beam and ring parameters (current, pressure, transverse beam sizes). The results of this study were then compared to the data collected from February to June 2016. We found good qualitative and quantitative agreement between our simulations and measurements. From this we could estimate that the level of background to be expected during luminosity monitoring will be two orders of magnitude smaller than the rate of the radiative Bhabha scattering signal.

Uppsatsen undersöker och jämför den tematiska och språkliga gestaltningen av den instabila identiteten i Johannes Anyurus roman En storm kom från paradiset och Sami Saids roman Väldigt sällan fin. De frågeställningar som behandlas är: Hur gestaltas den postkoloniala identitetens problematik i de båda romanerna? Hur tematiseras den instabila identiteten? Hur kan språket synliggöra en instabil identitet? För att undersöka den tematiska gestaltningen av det instabila subjektet utgår analysen från postkoloniala teorier vars grund finns i den poststrukturalistiska synen på verkligheten som en konstruktion styrd av makt och språk. Flera postkoloniala teoretiker utgår också från psykoanalytikern Jacques Lacans spegelteori i analysen av hur identiteten skapas i ett postkolonialt sammanhang. I diskussionen av det instabila subjektets språkliga gestaltning utgår uppsatsen från psykoanalytikern och litteraturvetaren Julia Kristevas teori om utanförskap som det poetiska språkets grund samt dess uttryck i vår tids skönlitteratur.

This study intends to investigate British artist Anish Kapoor’s stylistic formation in relationship to globalization, positing its history as a multiplicity, comprised of several competing localisms, including: minimalism; the traditions of modern painting; and the artist’s own personal diasporic narrative. It will demonstrate how Kapoor is a transgressive global artist, concerned not only with rethinking the longstanding question of artistic form, but also with the enduring process central to the cultural formation of subjects. Overall, this thesis will propose that Kapoor’s art in particular can be comprehended by the special liminal position it occupies between such polarities as modern and postmodern art, painting and sculpture, East and West, national and trans-national, and local and global. By transgressing the borders that demarcate these discourses, Kapoor’s art enters an in-between state; through both formal and thematic strategies, his sculptural forms orchestrate viewers so they are able to move beyond distinct, fixed, and stabile meanings and view the works as eminently open to the different perspectives and radically diverse discourses they engage, making them truly global works of art.

This essay explores and investigates post-colonial identity in Ireland in Hugo Hamilton’s The Speckled People: A Memoir of a Half-Irish Childhood (2003) and The Sailor in the Wardrobe (2006). Relying primarily on Homi K. Bhabha’s postcolonial criticism, which draws on some ideas from psychoanalysis, this essay argues that the autobiographies resonate well with the ideas of culture as a strategy of survival and of the post-colonial child as an analyst of Western modernity. Thus, three chosen concepts; ‘the Uncanny’, ‘Third Space’ and ‘Hybridity’ work together to reveal a recurring theme of split and duplicity in reference to the colonial past throughout. Furthermore they also reveal that the actual writing of the autobiographies in itself must be regarded as a way of responding to and negotiating that very same split and duplicity in reference to Ireland’s past.

No description available.

No description available.