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  • dissertations  (96)
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  • dissertations  (96)
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  • 1
    Language: English
    Description: A theoretical background is developed to explain in detail the link between the modular tensor category Z(Vec!G) and the representation category of a quasitriangular quasi Hopf algebra D! G. Using this link, a classification of the simple objects in Z(Vec!G) and formulas for the modular data of Z(Vec!G) are carefully derived. Then, code is written in GAP to produce the modular data of Z(Vec!G), given ! and G. This is used to create a database of modular data for the Drinfeld doubles of pointed fusion categories with dimension less than 47. This database as well as GAP code accompanying it can be found at https://tqft.net/web/research/ students/AngusGruen. For a basic example of how this database might be used, we briefly analyse patterns in the ranks of Z(Vec!G) as jGj varies and produce lower bounds for the number of Morita equivalence classes of pointed fusion categories of a given dimension less than 47. For dimensions below 32, these lower bounds agree with the lower bounds published by Mignard and Schauenburg in [1]. At dimension 32 we improve upon the published lower bound and for dimensions 33 through 47 we present the first set of lower bounds on the number of Morita equivalence classes of pointed fusion categories at each dimension.
    Source: National Library of Australia (Trove)〈img src=https://exlibris-pub.s3.amazonaws.com/Trove_reload.gif style="vertical-align:middle;margin-left:7px"〉
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  • 2
    Language: Swedish
    Description: The purpose of the work was to investigate and compare how two different theater-techniques can function in the preparatory work before two concerts. I chose to do two short concerts as the artistic part of the study, each with three songs. The first concert was prepared with Michael Chekhov's technique and the second one with Konstantin Stanislavski's Method.In the description of the musical and theatrical material I have explained the parts of Chekhov's and Stanislavski's techniques that I have been working wih - exercises and ways of thinking - as well as the six songs included in the study. I the process description I have outlined how I worked with the songs and what the outcome was, which exercises that turned out to work well and which didn't, and also reflected upon what the reasons for this might be.The conclusion is that one can gain a lot from working with both Chekhov and Stanislavski and that what works best is dependent on the situation and character of the song.
    Keywords: Fine Art ; Konstnärligt Arbete ; Scenisk Gestaltning ; Konserförberedelse ; Stanislavskij ; Tjechov ; Music, Bachelor'S Level ; Musik, Konstnärlig Kandidat ; Student Thesis, At Least 15 Credits ; Examensarbete, Minst 15 Hp
    Source: Uppsala University Library
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  • 3
    Dissertation
    Dissertation
    Ludwig-Maximilians-Universität München ; Fakultät für Physik
    Description: Der Ursprung und die Entwicklung unseres Universums zeigt sich gleichermaßen in der Raumzeit selbst wie in den Strukturen, die in ihr entstehen. Galaxienhaufen sind das Ergebnis hierarchischer Strukturbildung. Sie sind die massivsten Objekte, die sich im heutigen Universum bilden konnten. Aufgrund dieser Eigenschaft ist ihre Anzahl und Struktur hochgradig abhängig von der Zusammensetzung und Evolution des Universums. Die Messung der Anzahldichte von Galaxienhaufen beruht auf Katalogen, die nach einer beobachtbaren Größe ausgewählt werden. Die Anwendung einer Massen-Observablen-Relation (MOR) erlaubt es, die beobachtete Anzahl als Funktion der Observablen und der Rotverschiebung mit Vorhersagen zu vergleichen und so kosmologische Parameter zu bestimmen. Man kann jedoch zu Recht behaupten, dass diese Messungen noch nicht präzise im Prozentbereich sind. Hauptgrund hierfür ist das unvollständige Verständnis der MOR. Ihre Normalisierung, die Skalierung der Observablen mit Masse und Rotverschiebung und die Größe und Korrelation von intrinsischen Streuungen muss bekannt sein, um Anzahldichten korrekt interpretieren zu können. Die Massenbestimmung von Galaxienhaufen durch die differenzielle Lichtablenkung in ihrem Gravitationsfeld, i.e. durch den so genannten schwachen Gravitationslinseneffekt (weak lensing), kann erheblich hierzu beitragen. In dieser Arbeit werden neue Methoden und Ergebnisse solcher Untersuchungen vorgestellt. Zu ersteren gehören, als Teil der Datenaufbereitung, (i) die Korrektur von CCD-Bildern für nichtlineare Effekte durch die elektrischen Felder der angesammelten Ladungen (Kapitel 2) und (ii) eine Methode zur Maskierung von Artefakten in überlappenden Aufnahmen eines Himmelsbereichs durch Vergleich mit dem Median-Bild (Kapitel 3). Schließlich ist (iii) eine Methode zur Selektion von Hintergrundgalaxien, basierend auf deren Farbe und scheinbarer Magnitude, die eine neue Korrektur für die Kontamination durch Mitglieder des Galaxienhaufens einschließt, im Abschnitt 5.3.1 beschrieben. Die wissenschaftlichen Hauptergebnisse sind die folgenden. (i) Für den Hubble Frontier Field-Haufen RXC J2248.7-4431 bestimmen wir Masse und Konzentration mittels weak lensing und bestätigen die durch Röntgen- und Sunyaev-Zel'dovich-Beobachtungen (SZ) vorhergesagte große Masse. Die Untersuchung von Haufengalaxien zeigt die Abhängigkeit von Morphologie und Leuchtkraft sowie Umgebung (Kapitel 4). (ii) Unsere Massenbestimmung für 12 Galaxienhaufen ist konsistent mit Röntgenmassen, die unter Annahme hydrostatischen Gleichgewichts des heißen Gases gemacht wurden. Wir bestätigen die MOR, die für die Signifikanz der Detektion mit dem South Pole Telescope bestimmt wurde. Wir finden jedoch Diskrepanzen zur Planck-SZ MOR. Unsere Vermutung ist, dass diese mit einer flacheren Steigung der MOR oder einem größen-, rotverschiebungs- oder rauschabhängigen Problem in der Signalextraktion zusammenhängt (Kapitel 5). (iii) Schließlich zeigen wir, durch die Verbindung von Simulationen und theoretischer Modellierung, dass die Variation von Dichteprofilen bei fester Masse signifikant zur Ungenauigkeit von Massenbestimmungen von Galaxienhaufen mittels weak lensing beiträgt. Ein Modell für diese Variationen, wie das hier entwickelte, ist daher wichtig für die genaue Bestimmung der MOR, wie sie für kommende Untersuchungen nötig sein wird (Kapitel 6).
    Description: The story of the origin and evolution of our Universe is told, equivalently, by space-time itself and by the structures that grow inside of it. Clusters of galaxies are the frontier of bottom-up structure formation. They are the most massive objects to have collapsed at the present epoch. By that virtue, their abundance and structural parameters are highly sensitive to the composition and evolution of the Universe. The most common probe of cluster cosmology, abundance, uses samples of clusters selected by some observable. Applying a mass-observable relation (MOR), cosmological parameters can be constrained by comparing the sample to predicted cluster abundances as a function of observable and redshift. Arguably, however, cluster probes have not yet entered the era of per cent level precision cosmology. The primary reason for this is our imperfect understanding of the MORs. The overall normalization, the slope of mass vs. observable, the redshift evolution, and the degree and correlation of intrinsic scatters of observables at fixed mass have to be constrained for interpreting abundances correctly. Mass measurement of clusters by means of the differential deflection of light from background sources in their gravitational field, i.e. weak lensing, is a powerful approach for achieving this. This thesis presents new methods for and scientific results of weak lensing measurements of clusters of galaxies. The former include, on the data reduction side, (i) the correction of CCD images for non-linear effects due to the electric fields of accumulated charges (Chapter 2) and (ii) a method for masking artifact features in sets of overlapping images of the sky by comparison to the median image (Chapter 3). Also, (iii) I develop a method for the selection of background galaxy samples based on their color and apparent magnitude that includes a new correction for contamination with cluster member galaxies (Section 5.3.1). The main scientific results are the following. (i) For the Hubble Frontier Field cluster RXC J2248.7--4431 our lensing analysis constrains mass and concentration of the cluster halo and we confirm the large mass predicted by X-ray and Sunyaev-Zel'dovich (SZ) observations. The study of cluster members shows the relation of galaxy morphology to luminosity and environment (Chapter 4). (ii) Our lensing mass measurements for 12 clusters are consistent with X-ray masses derived under the assumption of hydrostatic equilibrium of the intra-cluster gas. We confirm the MORs derived by the South Pole Telescope collaboration for the detection significance of the cluster SZ signal in their survey. We find discrepancies, however, with the Planck SZ MOR. We hypothesize that these are related either to a shallower slope of the MOR or a size, redshift or noise dependent bias in SZ signal extraction (Chapter 5). (iii) Finally, using a combination of simulations and theoretical models for the variation of cluster profiles at fixed mass, we find that the latter is a significant contribution to the uncertainty of cluster lensing mass measurements. A cosmic variance model, such as the one we develop, is necessary for MOR constraints to be accurate at the level required for future surveys (Chapter 6).
    Keywords: Fakultät für Physik ; Natural sciences and mathematics ; Physics
    Source: Universitätsbibliothek der LMU Muenchen
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  • 4
    Dissertation
    Dissertation
    University of Nottingham
    Description: Economic, political and environmental factors have prioritized the need for research on phosphate (Pi) acquisition efficiency (PAE), Pi use efficiency (PUE) and Pi fertilizer uptake efficiency in crops. However, the coordination of molecular responses to Pi starvation and the mechanisms of Pi starvation tolerance have been investigated predominantly in model plants but remain elusive in grain crops, especially in wheat. This project investigates transcriptional profiles in wheat, particularly in the roots, as a response to nutrient availability focusing on phosphate (Pi). Furthermore, appropriate screening approaches and the difficulties in crop improvement, particularly for wheat, are discussed. Pi acquisition by plants is mediated by members of Pi transporter families. The roles of these Pi transporters in Pi partitioning and re-translocation is complex and the knowledge about their functioning in wheat still limited. Here, members of the Pht1 family in wheat were identified, their expression profiles determined when exposed to different nutrient regimes in roots and ear tissues at various developmental stages and their potential role as targets for genetic improvement discussed. In addition to Pi transporters, regulatory genes including transcription factors, signalling pathways and apparently other Pi-responsive genes with unknown function are also of critical importance. Therefore, the genome-wide responses to limited nutrient availability were investigated for the first time in roots of field-grown wheat exposed to limited nutrient availability resulting in the identification of several candidate genes for PAE/PUE improvement on the molecular level. These data were validated against other studies and across a wider wheat germplasm. Furthermore, the correlation of candidate gene expression to the nutritional status, Pi availability and PAE/PUE properties revealed four potential target genes which may be major contributors to genotypic diversity of this trait. However, there are still some agronomic bottlenecks which impede implementing Pi efficient crops and the application of molecular tools and marker genes.
    Keywords: 633.1 ; S Agriculture (General) ; Sb Plant Culture
    Source: Networked Digital Library of Theses and Dissertations
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  • 5
    Keywords: Geodynamics ; Marine Sciences
    Source: AGRIS (Food and Agriculture Organization of the United Nations)
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  • 6
    Dissertation
    Dissertation
    University of Cambridge
    Language: English
    Keywords: 301 ; Online Journalism
    Source: The British Library
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  • 7
    Keywords: Medizinische Fakultät ; Technology, Medicine ; Medical sciences and medicine
    Source: Universitätsbibliothek der LMU Muenchen
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  • 8
    Language: Norwegian (Bokmal)
    Source: BIBSYS Brage
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  • 9
    Dissertation
    Dissertation
    University of Nottingham
    Language: English
    Description: Economic, political and environmental factors have prioritized the need for research on phosphate (Pi) acquisition efficiency (PAE), Pi use efficiency (PUE) and Pi fertilizer uptake efficiency in crops. However, the coordination of molecular responses to Pi starvation and the mechanisms of Pi starvation tolerance have been investigated predominantly in model plants but remain elusive in grain crops, especially in wheat. This project investigates transcriptional profiles in wheat, particularly in the roots, as a response to nutrient availability focusing on phosphate (Pi). Furthermore, appropriate screening approaches and the difficulties in crop improvement, particularly for wheat, are discussed. Pi acquisition by plants is mediated by members of Pi transporter families. The roles of these Pi transporters in Pi partitioning and re-translocation is complex and the knowledge about their functioning in wheat still limited. Here, members of the Pht1 family in wheat were identified, their expression profiles determined when exposed to different nutrient regimes in roots and ear tissues at various developmental stages and their potential role as targets for genetic improvement discussed. In addition to Pi transporters, regulatory genes including transcription factors, signalling pathways and apparently other Pi-responsive genes with unknown function are also of critical importance. Therefore, the genome-wide responses to limited nutrient availability were investigated for the first time in roots of field-grown wheat exposed to limited nutrient availability resulting in the identification of several candidate genes for PAE/PUE improvement on the molecular level. These data were validated against other studies and across a wider wheat germplasm. Furthermore, the correlation of candidate gene expression to the nutritional status, Pi availability and PAE/PUE properties revealed four potential target genes which may be major contributors to genotypic diversity of this trait. However, there are still some agronomic bottlenecks which impede implementing Pi efficient crops and the application of molecular tools and marker genes.
    Keywords: 633.1 ; S Agriculture (General) ; Sb Plant Culture
    Source: The British Library
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  • 10
    Language: Norwegian
    Source: Norwegian Open Research Archives (NORA)
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