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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.
241

PERLA Ústí nad Orlicí / PEARL Ústí nad Orlicí

Kuruc, Adam January 2016 (has links)
The theme of the thesis is a study of the project of „brownfield“ conversion of ex used cotton factory hall PERLA, Bavlnářské závody, A.s in Ústí nad Orlicí city. Prepartory work has dealt whole complex. Thesis follows up only study of a elected part. There are demolished, maintained and brand new objects with underground level garages. Urban and mass solution creates a complex of buildings with a city-forming character and allows going follow the area.
242

Návrh a posouzení vybraných částí ŽB nosné konstrukce / Design and Assessment of Selected Parts of Load Bearing Structure

Vitálišová, Barbora January 2019 (has links)
The diploma thesis deals with the design of selected parts of reinforced concrete elements of the exhibition room. Simultaneously, the optimization of selected elements according to valid standards and Eurocodes was carried out and the impact of these changes on the economy of construction was developed.
243

Topological and electronic properties of electron-doped manganite thin films / Propriétés topologiques et électroniques des couches minces de manganite dopées

Vistoli, Lorenzo 28 May 2019 (has links)
Les couches minces d'oxyde présentent un large éventail de phénomènes physiques et riches diagrammes de phase, ajustables par l'ingénierie des déformations et des interfaces. Le CaMnO3, en particulier, est extrêmement sensible au dopage et aux contraintes d’épitaxie et, lorsqu'il est élaboré sous compression, il passe d'un état isolant et antiferromagnétique à un état métallique et faiblement ferromagnétique à seulement 2% de dopage au Ce.Nous avons utilisé une combinaison de spectroscopie de photoémission résolue en angle, de magnétotransport et de théorie de la fonctionnelle de la densité pour étudier les propriétés électroniques de ce matériau. Nous avons observé l'existence de deux porteurs de charge distincts, les électrons légers et les polarons lourds, dont la nature diffère en raison de leur couplage radicalement différent aux phonons. Nous attribuons ces différences à un remplissage relatif différent de la bande en raison des corrélations, qui améliorent considérablement le couplage aux phonons de la bande des polarons lourds. Les expériences de magnétotransport révèlent que la bande polaire domine le transport malgré sa mobilité réduite.La compression épitaxiale donne également lieu à une forte anisotropie magnétique qui stabilise des bulles magnétiques et s’accompagnent d’un effet Hall topologique. Cela suggère que ces bulles ont un caractère topologique. L'effet Hall topologique diverge lorsque la manganite s'approche de la transition métal-isolant à faible dopage. Nous avons utilisé une théorie récemment développée pour interpréter ce comportement, et nous concluons que des corrélations peuvent entrer en jeu, augmentant la masse effective des porteurs et par conséquent l'effet Hall topologique.Comme cette manganite est très sensible aux changements de densités de porteurs, nous avons développé des transistors à effet de champ ferroélectriques BiFeO3/(Ca,Ce)MnO3. Lors de la commutation de la polarisation ferroélectrique de la couche supérieure de BiFeO3, nous n'avons pu observer de changement notable dans les propriétés des couches de manganite sous-jacentes. Nous avons utilisé la microscopie électronique en transmission pour étudier les propriétés de ces bicouches avec une résolution atomique, et nous avons observé que l'épinglage de polarisation à l’interface BiFeO3/(Ca,Ce)MnO3 empêche une commutation complète de la polarisation et réduit ainsi la capacité opérationnelle de ces dispositifs. Néanmoins, nous avons pu détecter l’influence de la polarisation ferroélectrique sur les propriétés électroniques de la manganite à l’échelle atomique. / Oxide thin films feature a wide range of physical phenomena and rich phase diagrams tunable by strain and interface engineering. CaMnO3, in particular, is extremely sensitive to both doping and strain and, when grown with compressive strain, transitions from an insulating and antiferromagnetic state to a metallic and weakly ferromagnetic state at only 2% Ce doping.We used a combination of angle-resolved photoemission spectroscopy, magnetotransport, and density functional theory to study the electronic properties of this material. We observed the existence of two separate charge carriers, light electrons and heavy polarons, whose physical nature differs because of drastically different couplings to phonons. We ascribe these differences to a different relative band filling due to correlations, which enhance greatly the coupling to phonons of the heavy polarons band. Magnetotransport experiments reveal that the polaron band dominates transport despite its lower mobility.Compressive strain also gives rise to a strong magnetic anisotropy which stabilizes magnetic bubbles that accompany a topological Hall effect. This suggests that these bubbles have topological character, i.e. are skyrmion bubbles. The topological Hall effect diverges as the manganite approaches the metal-insulator transition at low dopings. We used a recently developed theory in order to interpret this behavior, and we conclude that correlations may come into play, enhancing the effective mass of the carriers, and in turn the topological Hall effect.As this manganite is highly sensitive to changes in doping and carrier density, we grew BiFeO3/(Ca,Ce)MnO3 ferroelectric field-effect transistors. Upon switching the ferroelectric polarization of the BiFeO3 top layer, we could not observe any sizable changes in the properties of the underlying manganite layers. We used transmission electron microscopy to study the properties of these bilayers with an atomic resolution, and we observed that polarization pinning at the BiFeO3/(Ca,Ce)MnO3 impedes a complete switch of the polarization and so reduces the operational capabilities of these devices. Nevertheless, we could detect modifications of the electronic properties of the manganite induced by polarization reversal at the atomic scale.
244

Stuart Hall and Power

Sedlmayr, Gerold 29 November 2018 (has links)
When thinking about Stuart Hall’s theoretical legacy, ‘power’ is probably not the first term that comes to mind. Concepts like representation, racism, ethnicity, encoding/decoding, articulation, conjunctural analysis etc. more readily suggest themselves and structure our reception of his work. Yet nonetheless, when taking a closer look, his entire oeuvre may be said to be permeated, on different levels, by themes that touch upon the issue of power, not least in connection with the concepts listed above. The latent omnipresence of power in Hall’s thinking is perhaps most readily detectable on the meta-level on which he situates and positions himself as a cultural-studies scholar, and it is this level that hence will be addressed first. In the second section, Hall’s view of power on the economic, social and state levels will be considered, particularly by pointing out his indebtedness to Antonio Gramsci’s conception of hegemonic power. In an attempt to let Hall speak for himself as much as possible, the section will provide quite a few quotes, many of which will be taken from the collaboratively written Policing the Crisis, in order to shed some light on his – and his co-authors’ – ideas about power. The third section attempts a systematisation of the issues raised, particularly by integrating a Foucauldian perspective on power, which was nearly as important for Hall as the Gramscian. The last section will conclude by returning to the beginning, reconsidering Hall’s self-positioning within the power/knowledge nexus that structures the discourse of cultural studies.
245

Dirty, Messy Business: Stuart Hall, Politics and the Political

Cord, Florian 29 November 2018 (has links)
In the past decades, political theory and philosophy have seen the canonization of a new conceptual difference, whose roots have been traced back to a number of thinkers, but whose main theoretical elaboration can be said to have begun with the Centre de recherches philosophiques sur le politique founded by Jean-Luc Nancy and Philippe Lacoue-Labarthe in 1980 and closed in 1984: the difference between la politique and le politique, or between ‘politics’ and ‘the political’. As Chantal Mouffe (2005a: 8f), borrowing Heidegger’s vocabulary, has pointed out, the two terms operate on different levels: whereas ‘politics’ refers to the ‘ontic’ level and designates the empirical ‘facts’ of political organization – practices, institutions, discourses, etc. – ‘the political’ implies a philosophical inquiry at the ‘ontological’ level, asking, as Lacoue-Labarthe and Nancy (1981: 12) put it, about the ‘essence of the political’. While, in theorists as diverse as Alain Badiou, Jacques Rancière, Slavoj Žižek, Claude Lefort, Roberto Esposito, Ernesto Laclau, and many others – most of them located on the political left – this inquiry has yielded very different results, they all agree on the basic necessity to make this distinction between conventional politics, on the one hand, and a more profound dimension concerning the institution of the social itself, on the other. Similarly, virtually all the thinkers mentioned are in agreement as to the state of the political in the contemporary world: they all see it as in danger of being ignored, repressed or neutralized in the context of what they criticize as increasingly ‘post-political’ and ‘post-democratic’ social arrangements. This critique of today’s post-politics is a powerful and important one. In the following, I want to argue that the work of Stuart Hall to some extent shares in – in fact, anticipates, since most of the relevant theories were developed after 1989 – this critical discourse. More specifically, I will 1) bring out and discuss Hall’s critique of post-politics; 2) elaborate upon his own understanding of the political, which is implicit in this critique and elsewhere in his writings – I will argue that Hall’s thought can be considered as belonging to what the sociologist Oliver Marchart (2010) has termed ‘the moment of the political’, insofar as it is a product of and response to our ‘post-foundational condition’, emphasizing as it does conflictuality, contingency and the groundlessness of society; 3) and finally, building on this, I will briefly talk about the conclusions concerning (ontic) politics that the post-foundationalism Hall shares with most of the other theorists I have mentioned leads him to, which are very different from those arrived at by philosophers such as Badiou, Rancière or Žižek and closer – partly via the shared engagement with Gramsci – to those of Mouffe and Laclau or Lefort.
246

Policing the Crisis: A Particular Mode of Analysis, Re-Constructed and Emulated

Kramer, Jürgen 29 November 2018 (has links)
No description available.
247

Stuart Hall, Gramsci, Foucault and Social Struggles: Two Case Studies

Borgstede, Simone 29 November 2018 (has links)
When I first came across Stuart Hall’s engagement with Gramsci in his analysis of Margaret Thatcher’s struggle for power, I was excited by how much his theoretical framework provided new perspectives to reflect on my own experiences of social and political struggles. Here was somebody who analysed social change in its contradictory fluidity as something in the making. Not from ‘out there’, but as someone acting on it. It haunted me how valuable his approach was for understanding the unexpected outcomes and victories of social movements – not only for a better understanding of history and society, but also with a view to actively partaking in these movements and shape them. In this paper, I will demonstrate the strength of Hall’s approach for highlighting the chances of social movements to achieve their alternative goals although they fight from a position of weakness against powerful adversaries. I have been (and still am) an active part of the two movements I want to explore. First, I will discuss the success of the squatters and their allies in defending ‘their’ houses in Hamburg’s St. Pauli Hafenstraße, where I still live, in the 1980s and 90s, and, second, the current2 struggle of the refugee group ‘Lampedusa in Hamburg’ for the right to stay in Germany despite the ‘Dublin’ regulations which force refugees to stay in those countries where they first arrived. Both of these struggles had to engage with and counter stereotypical representations. Both of them, as I will show, started by addressing “immediate troubles” and led to a deeper understanding that another world is not only needed, but also possible – “an entirely new form of civilization” (Hall 1987: 21). Therefore, I think it is worthwhile to engage with them.
248

Studium spintronických jevů v magneticky uspořádaných strukturách pomocí terahertzové spektroskopie / Study of spintronic phenomena in magnetically ordered stuctures using terahertz spectroscopy

Kubaščík, Peter January 2021 (has links)
The main objective of this thesis was to bring the first experimental evidence about the spin-Hall magnetoresistance (SMR) in the Terahertz (THz) spectral range. The time-domain THz spectroscopy (TDTS) was chosen as the main method, and we presented a new experimental scheme, which allows us to observe SMR or magnetoresistive effects with similar symmetry at a wide range of THz frequencies very efficiently. We focused on the study of SMR in the bilayers consisting of either a prototypical ferrimagnetic isolator or of heavy metal (FI/HM) and metallic stacks of ferromagnetic CoFeB and heavy metal Pt layer (FM/HM). While SMR shows a rapid decrease already at the lowest THz frequencies (< 1 THz) in the FI/HM structures, the SMR in FM/HM bilayers persists above 30 THz. These observations are then explained by a different mechanism of SMR. The second part of the thesis is devoted to the construction of the new TDTS setup and an easy-to-use model of the THz setup using the Gaussian description of THz radiation. The simulated results have been compared to corresponding experimental measurements using a spintronic THz emitter (STE). The last part of the thesis describes the emission of intensive THz pulses from large-area STE.
249

Investigation of the Effects of Compressive Uniaxial Stress on the Hole Carriers in P-type InSb

Vaughn, Bobby J. 12 1900 (has links)
The influence of uniaxial compression upon the Hall effect ad resistivity of cadmium-doped samples of InSb at 77 K, 64 K, and 12 K are reported. Unilaxial compressions as high as 6 kbar were applied to samples oriented in the {001} and {110} directions. The net hole concentration of the samples were about 5x10^13 cm^-3 at 77 K as determined from the Hall coefficient at 24 kilogauss. The net concentration of hole carriers decreases and then increases exponentially with stress at 77 k and 64 k, while at 12 k there is only a monotonic increase of carrier concentration with stress. Analysis of the hole concentration as a function of stress shows the presence of a deep acceptor level located about 90 meV above the valence band edge in additionb to the 10 meV vadmium acceptor level. The shallow acceptor level does not split with stress. The hole density data is represented very well by models which describe both the variation in the net density of states and motion of the acceptor levels as a function of stress.
250

Positionsbestämning av en roterande axel i en vinkelgivare / Position determination of a rotating axis in an angle sensor

Frough, Bahman Jahan January 2017 (has links)
This thesis includes a study of a touch-free sensor systems and different principles for measuring a magnetic field. An in-depth study was conducted to describe two important principles in these contexts, i.e. Magnetoresistance principle and the Hall Effect principle. A market evaluation of different sensor chips developed on these principles was conducted. Furthermore, the study should be linked to existing principles to determine the position of a rotating axis. Function tests show that the performance requirement for each component was met. The results based on verification tests show that it is important to have a better mechanical connection between drive and device. Temperature tests show that the system meets the project specification at room temperature, but large angular deviations occur in temperature change, especially when driving with short steps. This thesis can be continued by reprogramming the source code and developing new software that can control more parameters and make it more accurate at positioning. Another recommendation would be to investigate and compare other sensor chips because there are several sensors that can apply to the system. Further improvements can be made by performing more tests on the system. / Examensarbetet innefattar en studie om beröringsfritt givarsystem och olika principer för att mäta ett magnetfält. En fördjupad litteraturstudie utfördes för att förklara två viktiga principer i dessa sammanhang d.v.s. magnetoresistiva principen och hallgivarprincipen. En marknadsutvärdering av olika sensor-chip som utvecklats enligt dessa principer genomfördes. Vidare ska studien kopplas till kända principer för att bestämma positionen för en roterande axel. Funktionstester visar att prestandakravet för varje komponent uppfylldes. Resultaten baserade på verifieringstester visar att det är viktigt att ha en bättre mekanisk koppling mellan drivdon och enhet. Temperaturtester visar att systemet uppfyller projektets kravspecifikation vid rumstemperaturen men det uppkommer stora vinkelavvikelser vid temperaturförändring framför allt vid körning med korta steg. Detta arbete kan fortsättas genom omprogrammering av källkoden och utveckling av ny programvara som kan styra fler parametrar och göra det mer exakt vid positionsbestämning. En annan rekommendation skulle vara att undersöka och jämföra andra sensorchip eftersom det finns flera sensorer som kan tillämpa i systemet. Ytterligare förbättringar kan göras genom att utföra fler tester på systemet.

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