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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.
1

Vacuum calculations for hydrogen pellet targets at WASA and PANDA

Löfgren, Johan January 2014 (has links)
We have performed calculations in order to evaluate the vacuum conditions for the twohadron physics experiments WASA and PANDA. WASA is an ongoing experiment whereasPANDA is an experiment under construction. There is an interest in improving the vacuumconditions for these experiments in order to reduce background interactions. The experimentswere modelled as longitudinal conductance limited vacuum systems in the molecular flowregime and the calculations were performed with VAKLOOP. The approach was to fit amodel of WASA to measurement data and then extend this model to PANDA in order tomake predictions. The model of WASA was successful in the sense that it reproduced themeasurement data within the measurement uncertainty. The model of PANDA showed somediscrepancies in comparison with calculations from the Target Technical Design Report ofPANDA, but an overall similar pressure profile is obtained. Finally, we have considered a wayof improving the conditions at PANDA by including extra pumping capacity in the system,concluding that lowering the pressure at the interaction point for PANDA is challenging. Anoutlook for further modelling is to make a more detailed comparison between our model andthe one from the Target Technical Design Report.
2

Towards measurement of the ratio BR(η → 3π<sup>0</sup>) / BR(η → π<sup>+</sup> π<sup>- </sup>π<sup>0</sup>)

Heijkenskjöld, Lena January 2010 (has links)
<p>This diploma thesis presents a preliminary study of the ratio of branching ratio r = BR(η → 3π<sup>0</sup>) / BR(η → π<sup>+</sup> π<sup>- </sup>π<sup>0</sup>). The experimental data used is collected by WASA-at-COSY which is a 4π sr detector optimised to detect light mesons and their decay products and is situated in Jülich, Germany.The focus of the work is to see how different reconstruction methods for the detected particles can alter both the measured values of the  branching ratios and the luminosity dependence of these branching ratios. The results show that for some of the methods, the measured branching ratios have a clear luminosity dependence. Depending on method, the extracted branching ratios vary differently. A few different methods have been studied, so the results provides a qualitative understanding of the behaviour of the measured branching ratios for different luminosities.</p>
3

Towards measurement of the ratio BR(η → 3π0) / BR(η → π+ π- π0)

Heijkenskjöld, Lena January 2010 (has links)
This diploma thesis presents a preliminary study of the ratio of branching ratio r = BR(η → 3π0) / BR(η → π+ π- π0). The experimental data used is collected by WASA-at-COSY which is a 4π sr detector optimised to detect light mesons and their decay products and is situated in Jülich, Germany.The focus of the work is to see how different reconstruction methods for the detected particles can alter both the measured values of the  branching ratios and the luminosity dependence of these branching ratios. The results show that for some of the methods, the measured branching ratios have a clear luminosity dependence. Depending on method, the extracted branching ratios vary differently. A few different methods have been studied, so the results provides a qualitative understanding of the behaviour of the measured branching ratios for different luminosities.
4

Structural analysis of the 17th century warship Vasa : Influence of the dowels on the stiffness of the hull

Muñoz García, Marina, Hurtado Sierra, Juan Carlos January 2014 (has links)
After 333 years under depths of the Baltic Sea, the warship Vasa was salvaged and nowadayslies in a dry dock inside the Vasa Museum in Stockholm. Its current support system, which consists on eighteen cradle-stanchions pairs of steel, is not able to handle the present loads in a satisfactory manner. Experimental tests showed that the Vasa's hull is gradually deforming mainly due to creep behavior. Thus, in order to preserve the Vasa for future generations, a new support system has to be implemented in a foreseeable future. There are several factors to take into consideration for its construction, which are: the degradation of the oak, its current mechanical properties and its inhomogeneity in addition to the climatic conditions of the Museum and the impossibility of taking unlimited specimens for its analysis. Hence, it is crucial to investigate the areas where the stresses and deformations are critical in the ship and how affected is the stiffness of the hull, its most important component. In this dissertation work two Finite Element Analyses are accomplished. The first study consists on the creation of a superelement of a section of Vasa's hull with the intention of investigating the influence of the dowels on the stiffness of the hull. In the second analysis a simplied model of the entire warship Vasa is created in order to analyze it and locate possible critical areas on the hull due to its own weight and the stresses originated by the support system. The software selected for these simulations are Abaqus and CreoSimulate 2.0. From the first study it is concluded that that the dowels do not have a signicant influence in the stiffness coeffcients of the hull. The second analysis determines that the maximum stresses are located on the bottom part of the hull. This dissertation work concludes with a suggested future work.
5

Calderón, el cisma sueco de los Vasa y el tropo "Teatro del mundo" : estudios

Vasquez-Lopera, Julian January 1999 (has links)
The ancient concept "The world is a theatre" has been used by poets and philosophers at all times when talking about human conflicts or when describing human society. By focusing on the historical function of this use, the present dissertation examines four plays by Pedro Calderón de la Barca in relation to the schism of the Swedish Wasa dynasty: El sitio de Bredá, La protestación de la fe, La vida es sueño, Afectos de odio y amor. A parallel between Calderon's "auto sacramental" El gran teatro del mundo, Descartes' so called "mask" and the Neoplatonic "Art of Memory" (Giulio Camillo, Giordano Bruno, Robert Fludd) is established in order to explore the ontological and social background of the linguistic term "discourse". The heretic picture created by the European Counter Reformation is studied as the mimetic configuration of a collective fetish. Stephen Greenblatt's notion of "social energy" and Julia Kristeva's account of the fetish in poetical language, are, in this context, discussed with the intention to investigate how Calderón, to the Spanish audience, describes Wladislav Sigismund Vasa visit to Breda's siege and Queen Christina's convertion to the Catholic faith. The political and ideological debate of laws ruling the succession in Catholic and Protestant kingdoms are considered when discussing Diego de Saavedra y Fajardo's (from Catholic Spain) and Schering Rosenhane's (from Lutheran Sweden) political reflections on the issue; this is also compared to the ideological foundations of Calderon's play El gran teatro del mundo. Both King Sigismund Vasa's personal struggle to retain the Swedish crown and Queen Christina's abdication, are considered in the light of Calderon's La protestación de la fe and Rosenhane's political vision in his Hortus Regius. A special investigation is dedicated to the striking contrasts between the original emblems of Hortus Regius and those found today in Rosenhane's palace, having been painted there on the initiative of Rosenhane himself. The Catholic agitation against Machiavelli's definition of "virtue" and the Machiavellian and Catholic interpretation of "reason of state", are related to Calderon's theatre with the intention of evaluating the geopolitical aspects of Calderon's most famous play, La vida es sueño, and also with the purpose to initiate a discussion about the theatrical nature of political behaviour. The dissertation concludes by studying and comparing Calderon's, Bernardino de Rebolledo's (Spanish ambassador to Denmark at the time) and Francisco Bances Candamo's views on Queen Christina's personal aversion to marriage, with special attention paid to the symbolic dimensions of Queen Christina's Amaranta Order.
6

La vision de l'islam par Youssef Haddâd / The vision of Islam by Youssef Haddâd

Zogheib, Maroun 18 May 2012 (has links)
Discerner les différentes composantes de la religion permettra de saisir la portée de l'analyse que mène Haddâd. Quelle dimension porte sa conception de l'Islam ? Père Youssef Dûrra El-Haddad, surnommé le Maître (al-Ustâdh) est né en 1913 à Yabrûd Kalamûn en Syrie. Au Liban, il s'est consacré à la recherche et à l'écriture. Maître Haddad publiera des articles et écrira des livres jusqu'après sa mort en 1979. Sa consécration aux études coraniques et au rapport islamo-chrétien attire sur lui l'attention depuis les années de formation à Jérusalem, et devient à la base d'une œuvre enrichissante en langue arabe. Maître Haddad réfléchit sur l'Islam selon deux axes : 1. d'abord il cherche une nouvelle "définition" de l'Islam autrement dit il l'aborde d'une façon nouvelle et avec de nouveaux critères. 2. En deuxième lieu il pose l'assise d'une nouvelle stratégie du dialogue islamo-chrétien afin de proposer un credo commun. Le point culminant, de sa recherche est: Comment dialoguer entre musulmans et chrétiens et professer un credo unique ? Comment dire le rapprochement et en quels termes ? Comment considérer le dialogue et sur quelle base ? Pour Haddad, la référence commune et le critère ultime sont textuels. Confrontons donc les deux sources d'Ecrits avant d'aborder les points conflictuels. Mais Comment va-t-il faire pour atteindre ce but ? Comment atteindre la foi musulmane primitive ? Selon Maître Haddad, Les textes interrogés peuvent révéler le point de départ d'un dialogue voire d'un rapprochement entre les deux expressions de la foi. Il est donc bénéfique de se rencontrer sur un terrain d'entente. Haddad interroge donc l'ultime référence, le Coran, afin de mettre en relief l'importance de la Bible, Torah et Evangile, selon les écrits musulmans. Comment ramener l’Islam et le mettre avant le christianisme alors qu’il est historiquement après lui ? Ainsi, l'Islam pourrait-il être reconduit à découvrir ses sources chrétiennes. Ce déplacement des bases du dialogue est un des fondements sur lesquels s'appuie l'œuvre de Haddâd. La question qui se pose est la suivante: Comment situer sa théologie de l'Islam et comment classer sa vision ? Comment considère-t-il l'Islam, et qu'est ce qui différencie sa vision des autres approches de cette religion ? Cette étude analyse sa vision sur l’Islam et sur le dialogue islamo-chrétien telle qu’elle est présentée dans son œuvre. / By distinguishing the different components of Religion, one may be able to better understand the meaning behind Haddad’s analysis. Which dimension does the islamic conception take? Father Haddad, nicknamed the Master, was born in 1913 in Yabrud Kalamun, Syria. In Lebanon, he devoted his life to research and writing. He continued publishing articles and writing books until his death in 1979. His consecration to the Qur'anic studies and the christian-muslim relation attracted his attention since the years of training in Jerusalem; and it becomes at the base of a work rewarding in Arabic language. Master Haddad thinks of Islam from two perspectives: First, he sought a new 'definition' of Islam—addressed in a new way and with new criteria. Secondly, he laid the foundation of a new strategy of the Christian-Muslim dialogue in order to propose a common creed. The essential point of his research: how do we communicate between Muslims and Christians and profess a single creed? How do we define the approximation and in what terms? How do we consider the dialogue and on what basis? According to Haddad, the common reference and the ultimate criterion are textual. Therefore, let’s confront the two written sources before addressing the conflicting points. But how is he going to achieve this goal? How is he going to reach the primitive Muslim faith? According to Master Haddad, the texts surveyed can reveal the starting point of a dialogue or even of a rapprochement between the two expressions of faith. It is therefore beneficial to meet on common ground. Haddad interrogated the ultimate reference, the Qur'an, in order to highlight the importance of the Bible, Torah and Gospel, according to the Muslim writings. How do we bring the Islam and place it before the Christianity when it is historically after it? Thus, could Islam be extended to discover its Christian sources? This movement of the databases of the dialogue is one of the foundations on which Haddâd based his work. The question arises: How does he specify his theology of Islam and how does he classify his vision? How does he consider Islam, and what differentiates his vision from other approaches to this religion? This study analyzes its vision on Islam and on the christian-muslim dialogue as it is presented in his work.
7

Mesonic fusion - pion and eta meson production in light ion nuclear fusion reactions

Zartova, Irina January 2010 (has links)
The present thesis describes two experiments performed in the storage ring CELSIUS at The Svedberg Laboratory in Uppsala. In the first experiment the importance of three - nucleon clustering in the six - nucelon system was investigated. The total cross section for the production of the ground state and the 3.56 MeV second excited state of 6Li in the 3He(3He,6Li)π+ reaction has been measured at two beam energies, 261.1 and 262.5 MeV, corresponding to center - of - mass energies 1.2 and 1.9 MeV above the production threshold for the 3.56 MeV state. For the ground state the result was 347 ± 84 ± 42 and 92 ± 84 ± 11 nb respectively. The result for the 3.56 MeV state, 104 ± 23 ± 12 and 56 ± 35 ± 7 nb respectively, is compared to the result of a previous study where the 3.56 MeV state was populated in the d(4He,6Li)π0 reaction. In the second experiment a clean sample of 5×105 eta mesons was prepared by means of the d(p,3He)η reaction. Eta production was tagged by the precise determination of the kinetic energy of the associated 3He ions. In the subsequent decay of eta mesons, channels with lepton - anti - lepton pairs were studied in the WASA detector. In a separate study properties of the WASA deuterium pellet target were investigated and in particular the effects on the beam of the beam - target interactions. In both sets of experiments the fused nuclear system was detected by means of a zero - degree spectrometer with a semiconductor detector telescope. Choosing the detectors to match the rather different requirements, precise information regarding the identity and the momentum of the detected ions could be obtained in both cases.
8

Corporatizing Dhaka Water Supply And Sewerage Authority, Bangladesh

Mannan, IFFAT 06 January 2009 (has links)
Efforts to commercialize water supply and sanitation in Dhaka, Bangladesh, have been pushed vigorously by internal and external proponents of neo-liberalism. The thesis takes a critical look at these developments and analyzes the role of multinational finance institutions in this process. In particular, it looks into the role of these finance institutions in funding reform projects to corporatize Dhaka Water Supply and Sewerage Authority (WASA), examining the impacts on end users, especially marginalized sections of society. The thesis describes how, in the process of corporatization, Dhaka WASA is and will continue to be more assertive in its commercial orientation than it was previously. The paper also studies a highly touted ‘successful’ co-operative model for revenue management called Program for Performance Improvement (PPI), seen by some as an alternative to privatization. I argue that the model in fact emerged as a consequence of the commercialization efforts of neoliberal reforms and that the revenue management model has created an isolated business unit with a reclusive management that undermines the egalitarian objectives of the water utility as a public service entity. / Thesis (Master, Environmental Studies) -- Queen's University, 2009-01-06 12:06:45.901
9

Franska och italienska formtyper i den svenska nationaloperan Gustaf Wasa : Examensarbete i musikvetenskap vid Institutionen för Kultur och Estetik på Stockholms Universitet under höst-terminen 2016.

Wållberg, Per Emil January 2016 (has links)
Examensarbete på kandidatnivå om den svenska nationaloperan Gustaf Wasa. Arbetet går igenom operans olika formtyper och kategoriserar dessa, såsom rent fransyska, italienska, eller allahanda kombinationsformer deremellan.
10

Measurements of 2π<sup>0</sup> and 3π<sup>0</sup> Production in Proton-Proton Collisions at a Center of Mass Energy of 2.465 GeV

Koch, Inken January 2004 (has links)
<p>Neutral two- and three-pion productions in proton-proton collisions at a center of mass energy of 2.465 GeV have been studied using the WASA detector and an internal pellet target at the CELSIUS storage ring in Uppsala. An important part of the detector for the measurments was a central electromagnetic calorimeter composed of 1012 CsI crystals, which measured the photons originating from neutral pion decays. Test measurements and calibration procedures for this detector part were carried out. An important part of the analysis was the identification of the neutral pions from the invariant mass of the decay gammas and the use of Monte Carlo simulations to understand the detector responds.</p><p>Total cross sections for the pp→ppπ<sup>0</sup>π<sup>0</sup> and pp→ppπ<sup>0</sup>π<sup>0</sup>π<sup>0</sup> reactions are presented as well as distributions of relevant kinematical variables for the pp→ppπ<sup>0</sup>π<sup>0</sup> reaction.</p><p>The distributions show significant deviations from phase space predictions. These deviations are typical for resonance production. The excitation of two simultaneous Δ resonances seems to be the main reaction mechanism. </p>

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