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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.
101

Cultural Sociology – starkes Programm oder breiter Zugang?: The Oxford Handbook of Cultural Sociology (Rezension)

Wohlrab-Sahr, Monika 24 May 2024 (has links)
Mit diesen beiden Handbüchern zur Cultural Sociology liegen wichtige Dokumentationen eines neueren Forschungs- und Theorieprogramms vor, zu dem Jeffrey Alexander, damals noch an der University of California at Los Angeles, in den 1990er Jahren den Aufschlag gemacht hat (Alexander, 1996).
102

The physics of higher-spin theories

Kessel, Pan 07 December 2016 (has links)
Höhere Spin Theorien haben in den letzten Jahren große Aufmerksamkeit gefunden. Ein Grund dafür ist, dass diese Theorien dual zu besonders einfachen konformen Feldtheorien sind. Die einzigen bekannten wechselwirkenden höheren Spin Theorien wurden von Vasiliev in einem sehr ungewöhnlichen Formalismus und mit unendlich vielen Hilfsfeldern konstruiert. Die vorliegende Arbeit extrahiert die Physik, die durch diese Gleichungen beschrieben wird. Wir untersuchen im Detail die Wechselwirkungen, das Spektrum sowie die Lokalitätseigenschaften der Vasiliev Theorie. Diese Arbeit ist die erste systematische Untersuchung der Vasiliev Theorie auf wechselwirkender Ebene (nur ausgedrückt durch physikalische Felder). / Higher-spin theories have received significant attention over the last years. This is because they arise as the bulk duals of comparatively tractable conformal field theories. The only known interacting higher-spin theories were constructed by Vasiliev and are formulated in a highly non-standard way in terms of an infinite number of auxiliary fields. This thesis extracts physics out of Vasiliev theory. We study in detail its interactions, spectrum and locality properties. We consider both the three- and four-dimensional case. Our work represents the first systematic study of Vasiliev theory at the interacting level (in terms of physical fields only).
103

Measurements of local electric fields by doppler-free laser spectroscopy of hydrogen resonance lines

Adamov, Minja Gemisic 04 January 2007 (has links)
In dieser Arbeit wurde eine einfache laserspektroskopische Messmethode für lokale elektrische Feldstärken im Hinblick auf ihre Messmöglichkeiten und -grenzen untersucht. Als empfindliche optische Feldsensoren dienen dabei Wasserstoffatome, für die die Stark-Aufspaltung der Spektrallinien im elektrischen Feld wohl bekannt und exakt berechenbar ist. Die experimentellen Untersuchungen wurden an einer Niederdruck-Gaszelle durchgeführt, in der ein elektrisch geheizter Wolframdraht für thermische Dissoziation von Wasserstoffmolekülen sorgte. Die Wasserstoffatome wurden durch zwei gegenläufige Laserstrahlen Doppler-frei angeregt. Die Durchstimmung der schmalbandigen Laserstrahlung über den Wellenlängenbereich der Zwei-Photonen-Resonanz lieferte direkt das vom elektrischen Feld hervorgerufene Stark-Spektrum des angeregten Zustands. Weil die Methode im Gegensatz zu ähnlichen, erheblich aufwendigeren Verfahren nur die niedrigsten Wasserstoff-Energieniveaus benutzt, die mit Zwei-Photonen-Anregung direkt aus dem Grundzustand erreichbar sind, kommt sie mit einem einzigen Laser aus. Für das erste angeregte Niveau mit n = 2 wird Strahlung bei 243 nm benötigt, das nächsthöhere Niveau mit n = 3 erfordert 205 nm. Für n = 2 wurden Untersuchungen an Wasserstoff und Deuterium durchgeführt und Stark-Spektren mittels optogalvanischer Detektion gemessen. Schwerpunkt der Arbeit waren aber die Messungen an Wasserstoff für n = 3, bei denen zusätzlich Balmer-alpha-Fluoreszenz im Sichtbaren zur Detektion eingesetzt werden konnte. Bei elektrischen Feldern bis 200 V/cm wurden Stark-Spektren für drei verschiedene Polarisationszustände der Laserstrahlung aufgenommen. Als Ergebnis konnte jeweils ein Paar isolierter Stark-Komponenten in den Spektren identifiziert werden, dessen gut messbarer Frequenzabstand durch Vergleich mit theoretischen Werten die Bestimmung der elektrischen Feldstärke ermöglicht. / A method for electric field measurements that observes the Stark spectra of the low excited levels n = 2 and n = 3 of atomic hydrogen has been explored in this work. As advantage these levels can be excited Doppler-free from the ground state by a single laser and the highly resolved Stark spectra are easy to understand and to be calculated. Good sensitivity of electric field measurements is achieved with specially designed solid state laser systems, which provide tuneable pulsed UV radiation with a high pulse peak-power and a narrow bandwidth needed for Doppler-free two-photon excitation. Using hydrogen and deuterium the Stark spectra of the n = 2 level are detected as optogalvanic signal. For three different cases of laser polarization the n = 3 spectra of hydrogen are measured simultaneously with optogalvanic and laser induced Balmer alpha fluorescence detection. Electric fields down to 200 V/cm can be determined from the Stark spectra of n = 2 level, while the spectra of n = 3 level enable measurements of electric fields as small as 50 V/cm in each of the three cases of laser polarization.
104

Stability of polarization in organic ferroelectric metal-insulator-semiconductor structures

Kalbitz, René January 2011 (has links)
Organic thin film transistors (TFT) are an attractive option for low cost electronic applications and may be used for active matrix displays and for RFID applications. To extend the range of applications there is a need to develop and optimise the performance of non-volatile memory devices that are compatible with the solution-processing fabrication procedures used in plastic electronics. A possible candidate is an organic TFT incorporating the ferroelectric co-polymer poly(vinylidenefluoride-trifluoroethylene)(P(VDF-TrFE)) as the gate insulator. Dielectric measurements have been carried out on all-organic metal-insulator-semiconductor structures with the ferroelectric polymer poly(vinylidenefluoride-trifluoroethylene) (P(VDF-TrFE)) as the gate insu-lator. The capacitance spectra of MIS devices, were measured under different biases, showing the effect of charge accumulation and depletion on the Maxwell-Wagner peak. The position and height of this peak clearly indicates the lack of stable depletion behavior and the decrease of mobility when increasing the depletion zone width, i.e. upon moving into the P3HT bulk. The lack of stable depletion was further investigated with capacitance-voltage (C-V) measurements. When the structure was driven into depletion, C-V plots showed a positive flat-band voltage shift, arising from the change in polarization state of the ferroelectric insulator. When biased into accumulation, the polarization was reversed. It is shown that the two polarization states are stable i.e. no depolarization occurs below the coercive field. However, negative charge trapped at the semiconductor-insulator interface during the depletion cycle masks the negative shift in flat-band voltage expected during the sweep to accumulation voltages. The measured output characteristics of the studied ferroelectric-field-effect transistors confirmed the results of the C-V plots. Furthermore, the results indicated a trapping of electrons at the positively charged surfaces of the ferroelectrically polarized P(VDF-TrFE) crystallites near the insulator/semiconductor in-terface during the first poling cycles. The study of the MIS structure by means of thermally stimulated current (TSC) revealed further evidence for the stability of the polarization under depletion voltages. It was shown, that the lack of stable depletion behavior is caused by the compensation of the orientational polarization by fixed electrons at the interface and not by the depolarization of the insulator, as proposed in several publications. The above results suggest a performance improvement of non-volatile memory devices by the optimization of the interface. / Organische Transistoren sind besonders geeignet für die Herstellung verschiedener preisgünstiger, elektronischer Anwendungen, wie zum Beispiel Radio-Frequenz-Identifikations-Anhänger (RFID). Für die Erweiterung dieser Anwendung ist es notwendig die Funktion von organischen Speicherelementen weiter zu verbessern. Das ferroelektrische Polymer Poly(vinylidene-Fluoride-Trifluoroethylene) (P(VDF-TrFE)) eignet sich besonders gut als remanent polarisierbarer Isolator in Dünnschich-Speicherelementen. Um Schalt- und Polarisationsverhalten solcher Speicherelemente zu untersuchen, wurden P(VDF-TrFE)-Kondensatoren und Metall-Halbleiter-Isolator-Proben sowie ferroelektrische Feld-Effekt-Transistoren (Fe-FET) aus dem Halbleiter Poly(3-Hexylthiophene) (P3HT) und P(VDF-TrFE) hergestellt und dielektrisch untersucht. Die Charakterisierung der MIS-Strukturen mittels spannungsabhängiger Kapazitätsspektren machte deutlich, dass es nicht möglich ist, einen stabilen Verarmungzustand (Aus-Zustand) zu realisieren. Kapazität-Spannungs-Messungen (C-V) an MIS-Proben mit uni/bi-polaren Spannungszyklen zeigten eine stabile ferroelektrische Polarisation des P(VDF-TrFE)-Films. Eine Depolarisation des Isolators durch den Mangel an Minoritäts-Ladungsträgern konnte als Grund für die Instabilität des Verarmungs-Zustandes ausgeschlossen werden. Die C-V-Kurven wiesen vielmehr auf die Existenz fixierter, negativer Ladungsträger an der Grenzfläche hin. Zusammenfassend kann festgestellt werden: die Ursache der Ladungsträgerinstabilitäten in organischen ferroelektrischen Speicherelementen ist auf die Kompensation der ferroelektrischen Orientierungspolarisation durch "getrappte"(fixierte) negative Ladungsträger zurückzuführen. Dieses Ergebnis liefert nun eine Grundlage für die Optimierung der Isolator/Halbleiter-Grenzfläche mit dem Ziel, die Zahl der Fallenzustände zu minimieren. Auf diesem Wege könnte die Stabilität des Speicherzustandes in organischen Dünnschichtspeicherelementen deutlich verbessert werden.
105

Electrochemical Phase Formation of Ni and Ni-Fe Alloys in a Magnetic Field

Ispas, Adriana 02 November 2007 (has links) (PDF)
The aim of this work was to investigate the effects that a magnetic field can induce during the electrodeposition of Ni and Ni-Fe alloys. Special regard was given to mass transport controlled effects. Magnetic field effects on the nucleation and growth of ferromagnetic layers and on the properties of electrodeposited layers (like grain size, texture, morphology or roughness) were investigated. The influence of a magnetic field on the magnetic properties of Ni layers and on the composition of Ni-Fe alloys was also studied. Nucleation and growth of thin Ni layers on gold electrodes under a superimposed magnetic field were analysed in-situ with the Electrochemical Quartz Crystal Microbalance technique. Three theoretical models were chosen for characterizing the Ni nucleation: Scharifker-Hills (SH), Scharifker-Mostany (SM) and Heerman-Tarallo (HT). The AFM images proved that more nuclei appear in a magnetic field in the case that the Lorentz force and the natural convection act in the same direction. From all the models, the HT model gave the best agreement with the AFM results. When the Lorentz force and the natural convection act in the same direction, an increase of the Ni partial current with the magnetic field was obtained. When they act in opposite directions, the Ni current was influenced just at the beginning of deposition (first 10 seconds). At longer times, the magnetic field has no effect on the Ni current. However, the total current (jNi+jHER) decreases with the magnetic field. In the absence of a macroscopic MHD convection, the Ni current decreases with the magnetic field the first 10-15 seconds of deposition. On longer time scales no influence of the magnetic field could be noticed for this configuration. When the magnetic field was applied perpendicular to the electric current, an increase of the hydrogen evolution reaction (HER) with the magnetic flux density was noticed. Hydrogen reduction is mass transport controlled. Therefore, the magnetic field will increase the limiting current of the HER. Optical microscopy images showed that the hydrogen bubbles were circular in the absence of the MHD convection and that they presented a tail when a Lorentz force was present. The direction of the tail depends on the net force induced by the natural and MHD convections. The interplay between the natural and MHD convections proved to be important during Ni-Fe alloy deposition, too. When the Lorentz force and the natural convection act in the same direction, an increase of the Fe content of the alloys with the magnetic field was observed. When the Lorentz force was perpendicular to the natural convection, no significant changes were observed in the composition of the layers. The alloy composition did not change with the magnetic field when the electric current was parallel to the magnetic field lines. Two surfactants were used in the case that Ni was electrodeposited from a sulfamate bath: SDS and sulfirol 8. The Ni layers obtained from a sulfamate bath with sulfirol 8 presented larger grains compared to the layers deposited from a bath free of surfactants. This increase of the grain size was attributed to the incorporation of the surfactant in the deposit. Coarser layers were obtained in a magnetic field (applied perpendicular to the electric current) when the electrodeposition was done from an electrolyte with surfactants. The number of grains increased with the magnetic field for the Ni layers electrodeposited from a bath free of surfactants and for a bath with SDS. As a consequence, the grain size decreased. In the case of the electrolyte with sulfirol 8, the number of grains decreased with the magnetic field, and their size increased. For the Ni-Fe alloys, which contained less than 10 at% Fe, the preferred crystalline orientation changes from (220), in the absence of a magnetic field, to (111), (when the magnetic field was applied perpendicular to the electric current). When the magnetic field lines were parallel to the electric current, both the (111) and (220) textures were preferred in almost the same proportion. As a general conclusion of this work it can be said that by choosing the right experimental condition, one can improve the morphology and the properties of the deposited layers by applying a magnetic field. At the same time, the mass transport processes can be influenced by a magnetic field.
106

Solution strategies for stochastic finite element discretizations

Ullmann, Elisabeth 16 December 2009 (has links) (PDF)
The discretization of the stationary diffusion equation with random parameters by the Stochastic Finite Element Method requires the solution of a highly structured but very large linear system of equations. Depending on the stochastic properties of the diffusion coefficient together with the stochastic discretization we consider three solver cases. If the diffusion coefficient is given by a stochastically linear expansion, e.g. a truncated Karhunen-Loeve expansion, and tensor product polynomial stochastic shape functions are employed, the Galerkin matrix can be transformed to a block-diagonal matrix. For the solution of the resulting sequence of linear systems we study Krylov subspace recycling methods whose success depends on the ordering and grouping of the linear systems as well as the preconditioner. If we use complete polynomials for the stochastic discretization instead, we show that decoupling of the Galerkin matrix with respect to the stochastic degrees of freedom is impossible. For a stochastically nonlinear diffusion coefficient, e.g. a lognormal random field, together with complete polynomials serving as stochastic shape functions, we introduce and test the performance of a new Kronecker product preconditioner, which is not exclusively based on the mean value of the diffusion coefficient.
107

Diffusion on Fractals

Prehl, geb. Balg, Janett 15 June 2007 (has links) (PDF)
We study anomalous diffusion on fractals with a static external field applied. We utilise the master equation to calculate particle distributions and from that important quantities as for example the mean square displacement <r^2(t)>. Applying different bias amplitudes on several regular Sierpinski carpets we obtain maximal drift velocities for weak field strengths. According to <r^2(t)>~t^(2/d_w), we determine random walk dimensions of d_w<2 for applied external fields. These d_w corresponds to superdiffusion, although diffusion is hindered by the structure of the carpet, containing dangling ends. This seems to result from two competing effects arising within an external field. Though the particles prefer to move along the biased direction, some particles get trapped by dangling ends. To escape from there they have to move against the field direction. Due to the by the bias accelerated particles and the trapped ones the probability distribution gets wider and thus d_w<2. / In dieser Arbeit untersuchen wir anomale Diffusion auf Fraktalen unter Einwirkung eines statisches äußeres Feldes. Wir benutzen die Mastergleichung, um die Wahrscheinlichkeitsverteilung der Teilchen zu berechnen, um daraus wichtige Größen wie das mittlere Abstandsquadrat <r^2(t)> zu bestimmen. Wir wenden unterschiedliche Feldstärken bei verschiedenen regelmäßigen Sierpinski-Teppichen an und erhalten maximale Driftgeschwindigkeiten für schwache Feldstärken. Über <r^2(t)>~t^{2/d_w} bestimmen wir die Random-Walk-Dimension d_w als d_w<2. Dieser Wert für d_w entspricht der Superdiffusion, obwohl der Diffusionsprozess durch Strukturen des Teppichs, wie Sackgassen, behindert wird. Es schient, dass dies das Ergebnis zweier konkurrierender Effekte ist, die durch das Anlegen eines äußeren Feldes entstehen. Einerseits bewegen sich die Teilchen bevorzugt entlang der Feldrichtung. Andererseits gelangen einige Teilchen in Sackgassen. Um die Sackgassen, die in Feldrichtung liegen, zu verlassen, müssen sich die Teilchen entgegen der Feldrichtung bewegen. Somit sind die Teilchen eine gewisse Zeit in der Sackgasse gefangen. Infolge der durch das äußere Feld beschleunigten und der gefangenen Teilchen, verbreitert sich die Wahrscheinlichkeitsverteilung der Teilchen und somit ist d_w<2.
108

Musik in der Prosa von Günter Grass : Intermediale Bezüge  —Transmediale Perspektiven / The Role of Music in Günter Grass’s Fiction : Intermedial References —Transmedial Perspectives

Schirrmacher, Beate January 2012 (has links)
The thesis explores the role of music in Günter Grass’s novels. In pointing out the vital role of intermediality for Grass’s narrative strategies, the thesis opens up for a new, intermedial perspective on his work. It shows how references to music are used to realise Grass’s poetological concept “paspresenture” – the simultaneous presence of past, present and future – as well as his constant strive towards concreteness. The study draws on theories of intermediality, with a special focus on the role of transmedial media characteristics. It develops a transmedial methodology for analysing intermedial references, stressing how the notion of “musicality” within the text is created by media characteristics shared by both music and literature. Intermedial references are conceived as highlighting structures that are inherent in literature. The textual analyses of The Tin Drum (1959), Too Far Afield (1995) and Crabwalk (2002) are divided into three steps. First, explicit musical references in the narratives are interpreted as indexes pointing towards transmedial structures relevant to this specific context. Second, the examination demonstrates the prominent role of transmedial characteristics such as repetitivity, contrast, simultaneity and performativity within the texts. Third and last, the function of musical reference is discussed: in all three narratives, the focus on transmedial structures supplies a more consistent interpretation of passages which otherwise prove difficult to decipher. In Grass’s fiction, issues appear not to be discussed but performatively reenacted and thus remind more of musical than literary development. What is more, music – as handled by Grass – does not appear absolute or transcendent; rather, its manipulative potential is always prominent. However, the way musical references are used to realise Grass’s poetological aims stresses the bodily presence of musical performance, thus making music appear as the performative realisation of time.
109

High Magnetic Field Properties of Fe-pnictide Thin Films

Kurth, Fritz 08 December 2015 (has links) (PDF)
The recent discovery of high-temperature superconductivity in Fe-based materials triggered worldwide efforts to investigate their fundamental properties. Despite a lot of similarities to cuprates and MgB2, important differences like near isotropic behaviour in contrast to cuprates and the peculiar pairing symmetry of the order parameter (OP) have been reported. The OP symmetry of Fe-based superconductors (FBS) was theoretically predicted to be of so-called s± state prior to various experimental works. Still, most of the experimental results favour the s± scenario; however, definitive evidence has not yet been reported. Although no clear understanding of the superconducting mechanisms yet exists, potential applications such as high-field magnets and Josephson devices have been explored. Indeed, a lot of reports about FBS tapes, wires, and even SQUIDs have been published to this date. In this thesis, the feasibility of high-field magnet applications of FBS is addressed by studying their transport properties, involving doped BaFe2As2 (Ba-122) and LnFeAs(O,F) [Ln=Sm and Nd]. Particularly, it is important to study physical properties in a sample form (i.e. thin films) that is close to the conditions found in applications. However, the realisation of epitaxial FBS thin films is not an easy undertaking. Recent success in growing epitaxial FBS thin films opens a new avenue to delve into transport critical current measurements. The information obtained through this research will be useful for exploring high-field magnet applications. This thesis consists of 7 chapters: Chapter 1 describes the motivation of this study, the basic background of superconductivity, and a brief summary of the thin film growth of FBS. Chapter 2 describes experimental methods employed in this study. Chapter 3 reports on the fabrication of Co-doped Ba-122 thin films on various substrates. Particular emphasis lies on the discovery of fluoride substrates to be beneficial for epitaxy without compromising superconducting properties. It is worth mentioning, that a world record Tc of 28 K for Co-doped Ba-122 thin films is reported here. Chapter 4 describes high-field transport properties (up to dc 35 T) of epitaxial P-doped Ba-122 thin films prepared by MBE. Among the FBS, P-doped Ba-122 shows very high transport critical current densities, although the Tc is lower than for LnFeAs(O,F)[Ln=Sm and Nd]. Additionally, the film is microstructurally clean. These high Jc values are due to a high vortex line energy. Chapter 5 deals with transport properties of epitaxial SmFeAs(O,F) thin films. In the course of this work, a dc 45 T magnet has been used within collaboration with the National High Magnetic Field Laboratory at Tallahassee, FL, USA. SmFeAs(O,F) thin films have been prepared by molecular beam epitaxy (MBE). The investigated film shows a very high transport critical current density (Jc) of over 105 A/cm2 at 45T and 4.2K for both main crystallographic directions, which features favourable for high-field magnet applications. Additionally, by investigating the pinning properties, a dimensional crossover between the superconducting coherence length and the FeAs interlayer distance at 30-40K was observed. Chapter 6 reports on high-field transport properties of NdFeAs(O,F) thin films prepared by MBE. In this case, the transition from Abrikosov to Josephson vortices was observed around 20-30K. Additionally, the angular Jc data were scaled with the anisotropic GinzburgLandau approach. The obtained parameters at given temperature are observed to increase with decreasing temperature, which is different from Co-doped Ba-122. Chapter 7 summarises this work. / Die kürzliche Entdeckung von Hochtemperatur-Supraleitung in Fe-basierten Materialien löste weltweite Bemühungen aus, deren grundlegende Eigenschaften zu untersuchen. Neben vielen Gemeinsamkeiten mit den Kupraten und MgB2 sind wichtige Unterschiede wie nahezu isotropes Verhalten (im Gegensatz zu den Kupraten) und eine auffällige Paarungssymmetrie des Ordnungsparameters (OP) berichtet worden. Die OP-Symmetrie der Fe-basierten Supraleiter (FBS) wurde theoretisch als s± berechnet, noch bevor experimentelle Versuche unternommen wurden. Derzeit favorisieren experimentelle Ergebnisse das s±-Szenario, dennoch gibt es noch keine definitiven Nachweise. Obwohl noch kein komplettes Verständnis des supraleitenden Mechanismus existiert, wurden schon potentielle Anwendungen wie Josephson-Elemente und Hochfeldmagnete erforscht. In der Tat erschienen zahlreiche Veröffentlichungen über supraleitende Kabel, Bänder und auch SQUIDs. Diese Arbeit befasst sich mit der Durchführbarkeit von Hochfeld-Anwendungen durch die Untersuchung der Transporteigenschaften von FBS, namentlich Ba-122 und LnFeAs(O,F)[Ln=Sm und Nd]. Es ist von großer Wichtigkeit, die physikalischen Eigenschaften in einer Probenform zu untersuchen, die der Form in Anwendungen nahekommt (z.B. Dünnschichten), um dieselben Rahmenbedingungen vorgeben zu können. Es ist jedoch nicht einfach, epitaktische FBS Dünnschichten zu realisieren. Kürzlich gewonnene Erkenntnisse in der Herstellung von epitaktischen FBS-Dünnschichten ermöglichen nun ein tieferes Eindringen in die Transporteigenschaften. Die in diesen Untersuchungen gewonnenen Informationen stellen somit wichtige Argumente in der Diskussion um Hochfeld Anwendungen dar. Diese Arbeit besteht aus sieben Kapiteln: Kapitel 1 beinhaltet die Motivation dieser Arbeit, die Grundlagen der Supraleitung und eine kurze Zusammenstellung der bisherigen Arbeiten zur Dünnschichtherstellung von FBS. Kapitel 2 beschreibt experimentelle Methoden, die im Zuge dieser Arbeit verwendet wurden. Kapitel 3 berichtet von der Herstellung Co-dotierter Ba-122 Dünnschichten (Co-Ba-122) auf verschiedenen Fluoridsubstraten. Dabei wurde Augenmerk darauf gelegt, neben einem verbesserten epitaktischen Wachstum der Dünnschichten die supraleitenden Eigenschaften nicht zu beeinträchtigen. Anzumerken ist, dass in diesem Rahmen Tc-Rekord-Werte von 28 K in Co-Ba-122 erzielt werden konnten. Kapitel 4 beschreibt die Hochfeld-Transporteigenschaften epitaktisch gewachsener P-dotierter Ba-122 Dünnschichten, die durch MBE hergestellt wurden. Unter den FBS zeigt P-dotiertes Ba-122 enorm hohe kritische Transport-Stromdichten, obwohl das Tc niedriger ist als bei LnFeAs(O,F)[Ln=Sm und Nd]. Der Grund dafür konnte in der hohen Flusslinienkern-Energie des P-dotierten Ba-122 ermittelt werden. Kapitel 5 behandelt Transporteigenschaften von epitaktisch gewachsenen SmFeAs(O,F)-Dünnschichten. In diesem Zusammenhang wurde ein dc-45 T-Hochfeldmagnet in Zusammenarbeit mit dem National High Magnetic Field Laboratory in Tallahassee, Florida, USA, genutzt. SmFeAs(O,F)-Dünnschichten wurden mit dem Molekularstrahl-Verfahren (MBE) hergestellt. Die Schichten zeigen sehr hohe kritische Transport-Stromdichten (Jc) von über 105 A/cm2 bei 45 T und 4.2 K für beide kristallographische Hauptrichtungen, parallel zur c-Achse und in der ab-Ebene. Diese Ergebnisse sehen sehr verheißungsvoll für eine Verwendung in Hochfeld-Anwendungen aus. Zusätzlich konnte durch die Untersuchung der Pinning-Eigenschaften ein Dimensionsübergang zwischen supraleitender Kohärenzlänge und FeAs-Ebenenabstand im Bereich 30-40 K beobachtet werden. Kapitel 6 berichtet über die Hochfeld-Transporteigenschaften von NdFeAs(O,F)-Dünnschichten, die mithilfe des MBE-Verfahrens hergestellt wurden. In diesem Falle konnte ein Ubergang von Abrikosov- zu Josephson-Flusslinien im Temperaturbereich 20-30 K beobachtet werden. Zusätzlich konnte die winkelabhängige kritische Stromdichte mit dem anisotropen Ginzburg-Landau-Ansatz skaliert werden. Die erhaltenen Parameter für verschiedene Temperaturen steigen mit fallender Temperatur. Dieses Verhalten ist gegensätzlich zu dem in Co-dotiertem Ba-122 gefundenen. Kapitel 7 gibt eine Zusammenfassung dieser Arbeit.
110

Musik in der Prosa von Günter Grass : Intermediale Bezüge  —Transmediale Perspektiven / The Role of Music in Günter Grass’s Fiction : Intermedial References —Transmedial Perspectives

Schirrmacher, Beate January 2012 (has links)
The thesis explores the role of music in Günter Grass’s novels. In pointing out the vital role of intermediality for Grass’s narrative strategies, the thesis opens up for a new, intermedial perspective on his work. It shows how references to music are used to realise Grass’s poetological concept “paspresenture” – the simultaneous presence of past, present and future – as well as his constant strive towards concreteness. The study draws on theories of intermediality, with a special focus on the role of transmedial media characteristics. It develops a transmedial methodology for analysing intermedial references, stressing how the notion of “musicality” within the text is created by media characteristics shared by both music and literature. Intermedial references are conceived as highlighting structures that are inherent in literature. The textual analyses of The Tin Drum (1959), Too Far Afield (1995) and Crabwalk (2002) are divided into three steps. First, explicit musical references in the narratives are interpreted as indexes pointing towards transmedial structures relevant to this specific context. Second, the examination demonstrates the prominent role of transmedial characteristics such as repetitivity, contrast, simultaneity and performativity within the texts. Third and last, the function of musical reference is discussed: in all three narratives, the focus on transmedial structures supplies a more consistent interpretation of passages which otherwise prove difficult to decipher. In Grass’s fiction, issues appear not to be discussed but performatively reenacted and thus remind more of musical than literary development. What is more, music – as handled by Grass – does not appear absolute or transcendent; rather, its manipulative potential is always prominent. However, the way musical references are used to realise Grass’s poetological aims stresses the bodily presence of musical performance, thus making music appear as the performative realisation of time.

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