Dissertations / Theses on the topic 'Ondo State'

Following the logic of the proximate determinants framework for child survival analysis, the study shows how the main socioeconomic inequalities in neonatal, post-neonatal, and child mortality observed in 1981-86 Ondo State were produced. Unlike most previous studies of early childhood mortality factors in Nigeria, the study explicitly investigates the linking mechanisms between key socio-economic factors and child survival. Local area infrastructural development is shown to be the main socioeconomic factor in neonatal mortality while household disposable income status along with local area infrastructural development showed the strongest impacts upon post-neonatal mortality. Household disposable income status emerged as the main socioeconomic factor affecting mortality during ages 1-4, with maternal education showing no strong effects even in this age segment where its impact may be expected to be most strongly felt. The integrated analysis demonstrates that much of the observed infant mortality advantage of residence in more developed local areas is due to easier physical and real access to modern health services and that most of the child mortality benefits conveyed by high household income status derive primarily from better home sanitary conditions and secondarily from better quality of curative and home care for very ill children.

Decentralization through the political theory of federalism has been at the centre of policy experiments in the last six decades in Nigeria where development and governance institutions have embraced federalism, as a part of the process of political reform, based on the constitutional foundation for its adoption. Federalism is perceived to be the panacea for improvements in efficiencies of the public sector so satisfying the needs of the citizenry, ethnic, religious and political divides notwithstanding. By transferring decision-making powers closer to the grass roots, federalism improves governance, results in an equitable division of the national wealth and encourages critical development. Whilst the structure and process of government is crucial, it is not the sole determinant of what is considered to be good governance. Other factors that impact include the political culture in which subsidiary features such as corruption and civic activism influence the quality of federal governance. Federalism has largely failed to engender political stability and socio-economic development in Nigeria. This research examines the major shortcomings in its implementation and a detailed analysis of such factors may help in laying the foundation for improvements in the system.

This thesis examines the changing role of Nigeria's state system in integrated rural development, the post-war global effort to draw peasant producers irretrievably into commercial agriculture. The thesis analyzes policy and programme interventions by the state, or by international development institutions acting through the state, to promote capital-intensive agriculture as well as expand market-based exchange relations in rural Nigeria. The study's structural context is provided by southwestern Nigeria's experience in state-led agrarian change since the 1940s. Its immediate empirical referents are the Ekiti-Akoko Agricultural Development Project (EAADP) and the Ondo State Agricultural Development Project (ODSADEP), implemented successively in cocoa-growing Ondo State in the 1980s with World Bank assistance. Agriculmral change in southwestern Nigeria since the 19th century has been conceived in terms of the near-total absence of state intervention or its ubiquity; high turnover of multiple, conflicting policies, strategies and implementing agencies; and class-based conflict between state, capital, and peasantry. While these conceptions still capture the essence of state action in rural Western Nigeria, they have occasionally oversimplified reality. Existing analyses have also had a predominantly national and/or regional focus and reinforced established policy biases by emphasising export-crop agriculture to the near-total exclusion of food-cropping. The present study attempts a historical and structural analysis of the state's role since the 1940s, focusing on small-scale food farming at sub-regional and project levels. Quantitative and qualitative methods are applied to a data base comprising archival material; official documents and project reports; interviews with farmers and with officials; as well as a survey of farmers in four villages in north-eastern Ondo State, to analyze policy and socio-technical constraints to commercial agriculture, and to assess EAADP and ODSADEP's operations. The thesis concludes that state activism in rural Ondo State has produced mixed results. The reason, however, is not so much because small farmers have been unremitting opponents of capitalist methods as because local realities have been ignored in the design and implementation of official strategies. One policy implication of this is that the 'blueprint model' of planning must be reconstructed to promote greater local influence on development thinking. Another is the need to redefine the scale of development projects in favour of programmes with more modest objectives and performance targets. Above all, policy and political processes have to be opened up to autonomous farmers' groups.

This is a study of adsorption on three activated carbon substrates using solid- state NMR. The adsorbates used as probe molecules included a range of phosphates, phosphonates and deuterated water. High-resolution (^31)p and (^2)H NMR spectra have been obtained using magic-angle spinning and a single-pulse regime. The deuterium results include the generation of an adsorption isotherm. The traditional gravimetric analysis and NMR experiments were run concurrently. These results showed that the NMR technique was qualitatively and quantitatively accurate, while the proven adsorption isotherm theory could be applied to the NMR results. The additional information given by the (^2)H NMR results showed evidence of two distinct adsorption sites. Initial adsorption in the micropores gives a peak shifted by 6 ppm to low frequency of the liquid (^2)H(_2)O. This peak was broadened due to restricted motion in the micropores. The second peak was observed only at high relative humidities and was attributed to adsorption on the external surface or in macropores. The chemical shift was similar to that of the pure liquid. The (^31)p NMR results were used to directly observe the adsorption of phosphates with a range of molecular sizes. The NMR data were used to calculate the micropore accessibility for each phosphate. Differences in the adsorption mechanism were recorded, and direct comparison for each carbon gave some structural information. It was possible to follow competition reactions over time periods of 1 min to 24 hours. A battlefield simulation was studied, with (^2)H(_2)O and a phosphate competing for the adsorption sites. The NMR results showed that the phosphate was preferentially adsorbed into the micropores, displacing the (^2)H(_2)O However, the addition of (^2)H(_2)O to a carbon saturated with a phosphate enabled more phosphate to be adsorbed into the micropores via a cooperative mechanism. Measurements of the transverse relaxation for adsorbed molecules suggest that the broad micropore signal consists of some overlapping peaks. The peaks width similar chemical shift are attributed to adsorption in pores with differing dimensions. The natural linewidth involves broadening caused by restricted anisotropic motion within the micropores.

This dissertation presents solid-state NMR studies that probe the dynamic and conformational properties of polymers adsorbed on solid surfaces in the dry state. The systems studied include a series of ethylene based random copolymers where the binding group is modified, and two diblock copolymer systems where the blocks have different intrinsic mobilities and surface interactions. The thesis begins by looking at the structures formed by the adsorption of poly (ethylene-co-acrylic acid) (PEA), poly (ethylene- co-vinyl alcohol) (EVOH), poly (ethylene-co-vinyl acetate) (EVA), and polyethylene (PE) on metal oxide powders (zirconia and alumina). NMR spectroscopy, FTIR-PAS, and TGA were used to characterize the surface behaviour of the systems with comparisons made between the bulk and adsorbed copolymers. 13C CPMAS, 1H and T 1 relaxation measurements were all recorded with the aim of correlating the microscopic structure of the surface with changes in NMR data. The chain conformation of adsorbed ethylene copolymers was found to strongly depend on the binding strength of the polar sticker groups with the substrates.
The chain dynamics of adsorbed diblock copolymers in the dry state are reported for the first time. Poly (styrene)-b-poly ( t-butyl acrylate) (PS-PtButA) and poly (styrene)-b-poly (acrylic acid) (PS-PAA) were selected to vary both the block size and the binding strength. Once again the primary surface characterization methods are NMR spectroscopy, FTIR-PAS, and TGA. 13C CPMAS, 1H, T1, and T1rho relaxation measurements were all recorded with the aim of correlating the surface structures with changes in NMR data. For the most part, the observed trends in the chain mobilities of the anchor (PAA) and buoy (PS) blocks with block size can be correlated with the predicted mushroom, intermediate and extended brush structures which collapse upon removal of the solvent. However, the chain mobility of the PS buoys decreases with increasing anchor block size. Although the chain mobility of the PS buoys are moderately enhanced relative to the bulk state, the mobility is sufficiently restricted to comfirm the picture of a thin glassy layer with adhesive properties similar to the surface of bulk polystyrene.
The diblock copolymers poly (2-vinylpyridine), poly (isoprene)- b-poly (2--vinylpyridine), (PI-P2VP) and poly (isoprene)- b-poly (4-vinylpyridine) (PI-P4VP) were selected to complement the PS-PAA system as both systems have been studied by surface force microscopy. The large contrast in chain mobilities of the PI and PVP blocks allowed spectral editing through variation of the 13C cross polarization parameters. The trends in mobility with block size differ from that of PS-PAA in that the segmental mobility of the buoys increases with anchor block size as expected. The chain mobility of the collapsed PI brushes is significantly enhanced as compared to the bulk state, again supporting the interpretation of surface microscopy studies which require an entropically unfavorable flattened, yet rubbery, surface structure.

Despite much progress, the infection of oral biomaterials by bacterial and fungal cells remains an important problem in the clinic, affecting millions of patients worldwide. Although biofilm formation comprises a series of stages, the initial cell-surface interaction is crucial in determining infection of the biomaterial surface. By employing single-cell force spectroscopy (SCFS) and nanoindentation with the atomic force microscope (AFM), the biophysics of the bacteria-biomaterial surface interaction has been characterised for Streptococcus sanguinis, Staphylococcus aureus and Candida albicans. Initially, the development and optimisation of a protocol to harvest and immobilise living bacterial and fungal cells for AFM experimentation is described. In a next step, SCFS was utilised to explore the influence of implant surface nanotopography on the colonisation of S. aureus, utilising an in vitro polycarbonate implant model. Although nanotopography was not found to influence bacterial elasticity, it did increase the adhesion of S. aureus to the surface at early time points. Subsequently, the interaction between clinically relevant titanium (Ti) implant substrates and S. aureus and S. sanguinis cells was studied, which demonstrated strain-dependent differences in the unbinding patterns observed in AFM experiments. Worm-like chain (WLC) modelling of unbinding events was used to predict the length of the bacterial adhesins involved in the Ti-bacteria interaction, which were found to be different for S. aureus and S. sanguinis. Finally, the attachment of C. albicans to acrylic surfaces at the single-cell level was explored with AFM. C. albicans was found to exhibit morphology-dependent adhesion onto acrylic, with adhesion being increased in hyphal tubes compared to yeast cells. Also, experiments suggest a potential correlation between strain virulence and increased adhesion to surfaces. Future work should focus on utilising this in vitro AFM model to explore novel antiadhesive and antimicrobial approaches at the single-cell level.

Orientador: Valeriano Mendes Ferreira Costa
Tese doutorado) - Universidade Estadual de Campinas, Instituto de Filosofia e Ciencias Humanas
Made available in DSpace on 2018-08-14T22:33:03Z (GMT). No. of bitstreams: 1 Acco_MarcoAntoniodeCastilhos_D.pdf: 4219170 bytes, checksum: ecbacbdc973533562eab98fcc2a49ae4 (MD5) Previous issue date: 2009
Resumo: Esta tese busca apresentar e analisar criticamente quatro abordagens da teoria social contemporânea - neoliberais, pluralistas globalistas, neoinstitucionalistas históricos e neomarxistas -, oferecendo um balanço teórico sobre as estratégias metodológicas que mobilizaram, os argumentos que apresentaram e as conclusões a que chegaram sobre as complexas interações entre globalização e os Estados nacionais, em particular sobre as pressões para a transformação dos Estados nacionais induzidas, impulsionadas ou provocadas pela globalização, assim como, as teses que propõem - no sentido inverso dessa equação - os possíveis impactos das ações dos Estados na indução, inibição e/ou regulação dos processos de globalização. Se o que se tem em mente é a construção de uma agenda mais duradoura de reflexão sobre as interações entre Estados e formações sociais no mundo contemporâneo, esta tese argumenta que as abordagens teóricas com maiores possibilidades de perdurar são aquelas que articulam (a) uma economia política sofisticada para a análise das macro-instituições decisivas para a vida social contemporânea, (b) uma adequada economia política das escalas, particularmente aquela sobre os centros decisórios relevantes no mundo contemporâneo, e (c) uma forte determinação em incorporar a agenda democrática como elemento constitutivo dos projetos coletivos para as sociedades humanas
Abstrac: This work aims to critically shows and analysis four approaches of contemporaneous social theory - Neoliberals, Plural Globalists, Historical Neoinstitutionalists, and Neomarxists - on the complex interactions between globalization and national states, offering a theoretical comparison among the methodological strategies deployed, and the arguments and conclusions offered. It focuses in particular on the pressures for the transformations of the states induced, engendered or provoked by the globalization, as well as, in the opposite direction, on the thesis that advocate the role of the States in the induction, inhibition, and/or regulation of the processes of globalization. In this theoretical comparison - if we have in mind the setting of a more enduring agenda for the reflection on the interactions between states and social formations in the contemporary world - it is argumented that the theoretical approaches with more long-lasting possibilities are those that articulate (a) a sophisticated political economy for the analysis of the key macro-institutions of contemporaneous social life, (b) an adequated political economy of the scales, particularly one about the core decision making centres, and (c) a strong determination in considering the democratic agenda as a crucial element for any collective projects of the human societies
Doutorado
Doutor em Ciência Política

Dissertação apresentada à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciência Política e Relações Internacionais
A temática central desta dissertação são as eleições presidenciais dos Estados Unidos, sendo o objecto os chamados battleground states, ou seja, os Estados onde se disputam e decidem as eleições para a chefia de Estado norte-americana. Com uma abordagem inicial ao modo de funcionamento dos sistemas político e eleitoral dos Estados Unidos, desde a génese da fundação do país, até ao estado actual dos dois partidos que dominam o panorama político norte-americano, o presente trabalho apresenta uma visão geral sobre a política dos Estados Unidos para, de seguida, aprofundar a questão dos battleground states. Devido ao sistema singular das eleições presidenciais norte-americanas, apenas uma parte dos Estados são decisivos na escolha do Presidente dos Estados Unidos, o que leva a que os candidatos à Casa Branca concentrem os seus esforços e recursos nesses mesmos Estados, conhecidos como battleground states. Assim, este estudo tenta definir quais são os battleground states, divididos entre Estados toss-up (aqueles em que o vencedor é verdadeiramente uma incerteza) e os leaning (onde o resultado final pode ser disputado, mas nos quais um dos dois partidos parte com uma ligeira vantagem), de forma a procurar aclarar os Estados da União que, afinal de contas, têm o condão de decidir as eleições presidenciais norte-americanas. Depois de definidos os battleground states, o presente trabalho analisa-os, caso a caso, em particular a nível histórico, demográfico e político, de forma a dar a entender as razões e as causas que fazem desse Estado um battleground state em eleições presidenciais.
The main theme of this thesis is the United States of America’s presidential elections and the object of study is the battleground states of those elections, which are the competitive states and where the US presidential elections are decided. First of all, this thesis approaches the functioning of the United States’ political and electoral system, covering issues such as the foundation of the country or the bipartisan model that dominates US politics, presenting a general overview of the United States’ political landscape. After that, this study addresses the issue of the battleground states. Due to the distinctive system of the US presidential elections, some states are key to the choosing of the President of the United States. Therefore, presidential candidates concentrate their efforts and resources in those decisive states, known as battleground states. This thesis tries to define which states are the battleground states, dividing them into two categories: toss up (the ones where the winner is a total uncertainty) and leaning (states that are competitive but where a given party is a slight favorite). Afterwards, it may become clearer which states have the power to decide the US presidential elections. With the battleground states already defined, the study analyses them, one by one, specifically their historical, demographical and political backgrounds, in order to understand the reasons that make a state a battleground state in presidential elections.

La reconstruction d'états quantiques, ou tomographie, joue un rôle central dans les technologies quantiques, afin de caractériser les opérations effectuées et d'extraire de l'information sur les états résultats de traitements d'information quantique. Les méthodes répandues de tomographie reposent généralement sur des mesures idéales, effectuées une seule fois sur chaque préparation de l'état d'intérêt. Dans ce travail, nous utilisons une nouvelle méthode, appelée tomographie par trajectoires, qui consiste à enregistrer, pour chaque réalisation de l'état, la trajectoire quantique suivie par le système à l'aide d'une série de mesures successives du système, en présence d'imperfections expérimentales et de décohérence. On extrait alors plus d'information sur l'état à reconstruire et on est capable, à partir d'un ensemble de mesures accessibles données, de créer des mesures plus générales. À l'aide des techniques de l'électrodynamique quantique en cavité, nous avons préparé des états intriqués de photons micro-onde délocalisés sur deux modes distants. Nous avons ensuite reconstruit ces états par tomographie par trajectoires, dans un espace de Hilbert de grande dimension. Nous montrons que cette méthode permet de reconstruire l'état, de développer des stratégies de mesure adaptées pour accélérer l'extraction d'information sur les cohérences quantiques d'intérêt et qu'elle fournit une estimation de l'incertitude sur les coefficients de la matrice densité reconstruite
Quantum state estimation, or tomography, is a key component of quantum technologies, allowing to characterise quantum operations and to extract information on the results of quantum information processes. The usual tomography techniques rely on ideal, single-shot measurements of the unknown state. In this work, we use a new approach, called trajectory quantum tomography, where the quantum trajectory of each realization of the state is recorded through a series of measurements, including experimental imperfections and decoherence. This strategy increases the extracted amount of information and allows to build new measurements for a set of feasible measurements.Using the tools of cavity quantum eletrodynamics, we have prepared entangled states of microwave photons spread on two separated modes. We have then performed a trajectory tomography of these states, in a large Hilbert space. We have proved that this method allows to estimate the state, to develop faster strategies for extracting information on specific coherences of the state and to compute error bars on the components of the estimated density matrix

A quantum mechanical state may be transferred between locations using quantum teleportation.Specically information encoded in the polarized state of a light pulse maybe teleported onto the collective spin state of an ensemble of atoms. This thesis providesa theoretical framework for achieving such a teleportation protocol experimentally.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Esta Tese aborda a questão do Estado e dos direitos de cidadania, particularmente dos direitos sociais e políticas a eles correspondentes, que constituem o que se convencionou tratar por Estado do bem-estar social, ou welfare state. Nela é analisado o processo recente de contradição entre as idéias e políticas neoliberais e o sistemas de welfare state, procurando verificar o impacto daquelas políticas sobre os sistemas. O objetivo central é mostrar que a ofensiva neoliberal vem sendo mal sucedida em sua tentativa de desarticular as instituições dos direitos e políticas sociais no que diz respeito às sociedades mais complexas e desenvolvidas. A principal razão disto deriva da própria história do welfare state, que corresponde a um longo processo de transformação da relação política entre Estado e sociedade. O estudo do impacto efetivo das políticas neoliberais sobre os sistemas de bem-estar ou proteção social, a que se convencionou tratar por welfare state está centrada no que vem ocorrendo nos países desenvolvidos, fazendo um contraponto com o que se passa no Brasil. Este tema tem sido objeto de preocupação de um grande número de analistas no exterior e no Brasil em função tanto do conteúdo das propostas neoliberais em relação às políticas sociais fortalecimento das soluções de mercado, restrição e das políticas públicas de proteção social nos grupos mais pobres da população quanto do sucesso avassalador que o neoliberalismo alcançou nos campos da economia e do trabalho. A Tese defende a idéia de que a sociedade brasileira e seu welfare state chegaram a um nível tal de complexidade, que não pode mais ser compreendida com base num ferramental analítico que tende a reduzir suas singularidades à configurações muito amplas ora denominadas por periferia do sistema capitalista, ora por realidade latino-americana, as contribuem para simplificar a análise e dificultar o aprofundamento da discussão em relação ao conteúdo, ao rumo e ao alcance do processo político e das políticas sociais.
The object of this thesis is the relation between the State and citizenship rights, specially the social rights and the correspondent social policies that are known as the welfare state. The analysis is concentrated on the impact of neoliberal proposals on the organisation and functioning of the welfare state, with an overview of the Brazilian situation. The main objective of the study is to demonstrate that the pressures based on neoliberal ideology and policies had little impact on the welfare state and that the main reason for this is based on the very history of the welfare state, which corresponds itself to a long process of transformation of the relations that exists between the State and the society. The thesis argues that the strengthening and diversification of the social rights have lead to a transformation of the State and the development of complex relations at the political level, that makes social policies and institutions very resistant to changes directed to the diminishing of social benefits and to replace state actions and policies by market mechanisms in the organisation, financing and deliverance of social services. This thesis supports in addition the idea that the degree of complexity achieved by the Brazilian society and its welfare state demand the use of analytic approaches different than those that predominate in present studies that tend to generalisations such as periphery and Latin-American reality which are insufficient and simplify the debate about the nature, the ways and the reach of social policy in Brazil.

Nanoparticulate drug delivery systems (NDDS) such as nanocrystals, nanosuspensions, solid-lipid nanoparticles often formulated for the bioavailability enhancement of poorly soluble drug candidates are stabilized by a mixture of excipients including surfactants and polymers. Most literature studies have focused on the interaction of excipients with the NDDS surfaces while ignoring the interaction of excipients in solution and the extent to which the solution-state interactions influence the affinity and capacity of adsorption. Mechanisms by which excipients stabilize NDDS and how this information can be utilized by formulators a priori to make a rational selection of excipients is not known. The goals of this dissertation work were (a) to determine the energetics of interactions between HPMC and model surfactants and the extent to which these solution-state interactions modulate the adsorption of these excipients onto solid surfaces, (b) to determine and characterize the structures of various aggregate species formed by the interaction between hydroxypropyl methylcellulose (HPMC) and model surfactants (nonionic and ionic) in solution-state, and (c) to extend these quantitative relationships to interpret probable mechanisms of mixed adsorption of excipients onto the model NDDS surface. A unique approach utilizing fluorescence, solution calorimetry and adsorption isotherms was applied to tease apart the effect of solution state interactions of polymer and surfactant on the extent of simultaneous adsorption of the two excipients on a model surface. The onset of aggregation and changes in aggregate structures were quantified by a fluorescence probe approach with successive addition of surfactant. In the presence of HPMC, the structures of the aggregates formed were much smaller with an aggregation number (Nagg) of 34 as compared to micelles (Nagg ~ 68) formed in the absence of HPMC. The strength of polymer-surfactant interactions was determined to be a function of ionic strength and hydrophobicity of surfactant. The nature of these structures was characterized using their solubilization power for a hydrophobic probe molecule. This was determined to be approximately 35% higher in the polymer-surfactant aggregates as compared to micelles alone and was attributed to a significant increase in the number of aggregates formed and the increased hydrophobic microenvironment within these aggregates at a given concentration of surfactant. The energetics of the adsorption of SDS, HPMC, and SDS-HPMC aggregate onto nanosuspensions of silica, which is the model solid surface were quantified. A strong adsorption enthalpy of 1.25 kJ/mol was determined for SDS adsorption onto silica in the presence of HPMC as compared to the negligible adsorption enthalpy of 0.1 kJ/mol for SDS alone on the silica surface. The solution depletion and HPMC/ELSD methods showed a marked increase in the adsorption of SDS onto silica in the presence of HPMC. However, at high SDS concentrations, a significant decrease in the adsorbed amount of HPMC onto silica was determined. This was further corroborated by the adsorption enthalpy that showed that the silica-HPMC-SDS aggregation process became less endothermic upon addition of SDS. This suggested that the decrease in adsorption of HPMC onto silica at high SDS concentrations was due to competitive adsorption of SDS-HPMC aggregates wherein SDS is displaced/desorbed from silica in the presence of HPMC. At low SDS concentrations, an increase in adsorption of SDS was due to cooperative adsorption wherein SDS is preferentially adsorbed onto silica in the presence of HPMC. This adsorption behavior confirmed the hypothesis that the solution-state interactions between pharmaceutical excipients such as polymers and surfactants would significantly impact the affinity and capacity of adsorption of these excipients on NDDS surfaces.

El trabajo realizado en esta tesis se enmarca dentro de las principales líneas de investigación del grupo de compostaje (GICOM), por una parte, en la valorización de residuos sólidos por medio de la fermentación en estado sólido (FES) para la obtención de productos de valor añadido en consoncia con el nuevo paradigma de considerar los residuos como materias primas y, en segundo lugar, en la utilización de nanomateriales para potenciar el uso de los productos obtenidos mediante FES. La primera parte se centra en el aprovechamiento de residuos sólidos para la producción de enzimas de interés, concretamente proteasas. Las enzimas se produjeron a partir de la FES de la mezcla de residuo de pelo vacuno procedente de la industria de curtidos y lodos procedentes del proceso de digestión anaerobia utilizado como cosubstrato e inóculo. Por una parte se ha demostrado la capacidad de producir proteasas y sus posibles aplicaciones en la propia industria, ya que se han obtenido buenos resultados en el proceso del depilado del cuero. Además, se ha establecido un esquema para el tratamiento posterior a la fermentación, incluida la reutilización de los residuos generados a lo largo del proceso de modo que se aproxime a un sistema de residuo cero. La segunda parte del trabajo consistió en una exploración preliminar para determinar cuáles son los soportes más eficientes para inmovilizar las proteasas producidas por FES de cara a su uso continuado y su mejor preservación. Se utilizaron proteasas obtenidas a partir de la FES de residuos ricos en nitrógeno, pelo vacuno utilizado en la primera parte del trabajo y residuo de soja de una industrial alimentaria. Se evaluó la aplicabilidad, reutilización, reproducibilidad y coste de los soportes para su uso en la inmovilización de dichas proteasas. La evaluación se efectuó con 10 materiales considerando su bio-compatibilidad con las proteasas: nanopartículas de oro (NpAu), perlas de quitosano (húmedas y secas), perlas de quitosano con nanopartículas de oro (Quitosan/Au), zeolitas funcionalizadas, resina aniónica A520, resina aniónica con nanopartículas de oro (A520/Au), nanopartículas de óxido de hierro (Fe3O4) y nanopartículas de óxido de titanio (TiO2). La eficiencia de la inmovilización se determinó a partir del rendimiento de inmovilización y la carga enzimática de cada soporte (U/mg). Las nanopartículas de óxido de hierro resultaron ser un soporte prometedor gracias a su bajo coste y a su fácil separación de forma magnética, aumentado así sus posibilidades de reutilización. En último lugar, tanto las proteasas obtenidas a partir de los residuos de pelo como las de residuo de soja se inmovilizaron para ser evaluadas en la hidrólisis de proteínas, cuya eficiencia se comparó con la de las enzimas libres en el medio. Se utilizaron substratos de diferente origen (animales y vegetales): caseína, albúmina de huevo y proteína de salvado de avena, observado un efecto diferente según el origen de la proteasa utilizada. Estos resultados se corroboraron con los aminoácidos liberados tras la hidrólisis de las proteínas. En términos globales, este estudio representa una investigación multidisciplinaria que abarca, por una parte, la gestión y valorización de residuos orgánicos mediante el proceso de fermentación en estado sólido, con la producción y recuperación del producto de interés, incluyendo la etapa de postratamiento y así como la aplicabilidad del producto. Además, la immbolización de las proteasas sobre nanopartículas de bajo coste se ha demostrado efectiva en la hidrólisis de proteinas tipo, consistuyendo una alternativa de bajo coste (tanto su producción como el soporte) a las técnicas actuales.
In line with the main research lines of Composting research group (GICOM), this thesis focuses on the valorisation of solid organic residues and the utilisation of nanomaterials. Thus the thesis mutually linked the studies by transforming the solid waste using solid state fermentation (SSF) into value-added products and the use of nanoparticles to enhance the use of products obtained from SSF. The first major part covers the valorisation of solid waste and transforms it into valuable product namely protease. The protease was produced through the fermentation of hair waste and anaerobically digested sludge (ADS) acting as co-substrate and inoculum. For industrial application, the protease produced from this work has shown a good result on dehairing of cowhides. This chapter not only demonstrated from the production of protease until application on industrial activity but also exhibited the downstream processing in SSF and reutilisation of the remaining residues after SSF which was a crucial thing to establish a zero discharge. The second major part consisted of a preliminary screening work intending to determine the most suitable support for immobilisation of proteases. Proteases produced from two different protein-rich solid wastes: hair waste and soy fibre residue. The work aimed to find the feasible, reusable, reproducible, and cost-effective supports or carrier to be exploited for protease immobilisation. There were 10 materials were assessed for their biocompatibility with the protein: gold nanoparticles (AuNps), chitosan beads (wet and dry), chitosan beads coupled with gold nanoparticles (chitosan/Au), functionalised zeolite particles, the anionic resin (A520), anionic resin coupled with gold nanoparticles (A520/Au), magnetic iron oxide (Fe3O4) nanoparticles (MNPs), titanium oxide nanoparticles (TiO2_A and TiO2_B). The immobilisation efficiency was monitored based on immobilisation yield (% IY) and enzyme loading per carrier (U/mg). Iron oxide nanoparticles were shown as a promising support thanks to its low-cost and easy separation by a magnetic force, thus increasing their possibilities of reuse. In the last part of the thesis, both of the proteases from hair waste and soy fibre residue were immobilised on the support and were tested for application in protein hydrolysis. The efficiency of immobilised enzymes was compared with the free enzymes during the protein hydrolysis. Not to mention, the use of the different type of proteases (animal and plant origin) also was assessed during the protein hydrolysis of different type of protein (casein, egg white albumin, and oat bran protein isolate), since different protease produce different effect towards certain substrates. The amino acids released after hydrolysis reaction were well balanced with the degree of hydrolysis according to each protein substrates. Overall, the study represented a multidisciplinary research field spanning waste management using solid state fermentation including the downstream processing and its application. In addition, the immobilisation of proteases on low-cost nanoparticles has been shown to be effective in the hydrolysis of proteins, being a low-cost alternative (both production and support) to actual techniques.

Ce travail de thèse a été réalisé au Laboratoire de Physique Subatomique et de Cosmologie (IN2P3) deGrenoble en collaboration avec le groupe Thalès avec pour objectif le développement d’une nouvellegénération de plasmas micro-onde fonctionnant sur une gamme de pression étendue allant de 0,5 mtorrà 10 torr en argon. La travail présenté porte donc en : i) la conception des applicateurs basés sur destronçons de longueur λ/4 faisant office de transformateurs d’impédance entre le générateur et leplasma d’impédance supposée donnée (adaptation d’impédance approchée); ii) la déterminationexpérimentale de l’impédance réelle du plasma (partie réelle et partie imaginaire) par mesure dumodule et de la phase du coefficient de réflexion dans des conditions opératoires définies; iii) leredimensionnement des différents tronçons de l’applicateur par simulation numérique en tenantcompte de l’impédance réelle du plasma; iv) la validation expérimentale de l’adaptation d’impédanceentre générateur et plasma. Les résultats obtenus démontrent clairement qu’il est possible, à fréquencedonnée (2.45 GHz dans le cas présent), de concevoir et de dimensionner une source plasma avec uneefficacité énergétique supérieure à 80% pour des fenêtres en pression (d’au moins une décade)équivalentes à des fenêtres opératoires en termes de paramètres plasma. Ces sources individuelles àabsorption localisée de micro-ondes peuvent être utilisées en nombre pour la réalisation des plasmasuniformes de grandes dimensions par leur distribution selon des réseaux à deux dimensions (sourcesplanes) ou à trois dimensions (volumes de plasma), et donc pour des applications industrielles auxtraitements de surface
This work was done in the « Laboratoire de Physique Subatomique et de Cosmologie (IN2P3,Grenoble) » during a collaboration with Thales. The aim of the project was the development of a newgeneration of microwave plasma with extended operating conditions in the pressure range 0.5 mtorr to10 torr in argon. The presented work consists of: i) designing applicators based on sections of λ/4length serving as impedance transformers between the generator and the plasma with impedance ofgiven assumed value (approximate impedance adaptation); ii) experimentally determine the realplasma impedance (the real part and the imaginary part) for given operating conditions from themeasurement of modulus and phase of the reflection coefficient S11; iii) resize the different sections ofthe applicator by digital simulation taking the real plasma impedance into account; iv) finally, verifyexperimentally that the impedance adaptation between the generator and the plasma is correct. Theobtained results clearly demonstrate that it is possible, at a given frequency (here 2.45 GHz), to designand size a plasma source with an efficiency greater than 80 % for a window in pressure (at least onedecade) equivalent to an operating window in terms of plasma parameters. These individual sourceswith localized absorption of microwaves can be used in numbers to achieve uniform plasmas via theirdistribution over two-dimensional (planar sources) or tri-dimensional (volume plasma) networks, andthus for industrial surface treatments

Neste trabalho foi desenvolvido um estudo sobre a precessão livre de onda contínua (CWFP-continuous wave free precession), uma condição especial da precessão livre no estado estacionário (SSFP), e algumas aplicações. Os resultados experimentais, e de simulações, mostraram que este sinal é atingido após a passagem por dois estágios iniciais. O primeiro é dependente da não homogeneidade do campo magnético, relacionado a razão Tp/T2*. O segundo, o qual é chamado de estado quasi-estacionáio, é dependente ambos os tempos de relaxação do sistema em estudo, T1 e T2. Este segundo estágio é responsável por levar a magnetização do estado de equilíbrio térmico a um estado verdadeiramente estacionário. Tendo como informação a amplitude da magnetização no estado de equilíbrio térmico e no estado verdadeiramente estacionário, e também do decaimento do sinal durante o estado quasi-estacionário, é possível determinar, rápida e simultaneamente, ambos os tempos de relaxação do sistema, fazendo um único experimento. Esse método oferece aplicações interessantes para o estudo de processos dinâmicos, propostas também neste trabalho. Foi possível verificar que o sinal de CWFP pode ser utilizado para acompanhar cinética de reações, e também variações de viscosidade do meio, por exemplo, em reações de polimerização, associadas à mobilidade molecular em função de mudanças estruturais. Um método para avaliar a condutividade térmica de elastômeros foi proposto, com o fornecimento de resultados quantitativos muito próximos daqueles encontrados na literatura, e que utilizam outros métodos. A dependência do sinal de CWFP com a freqüência de offset também permitiu realizar um estudo, com aplicação em RMN de alta resolução, sobre a supressão de sinal de solvente. Os resultados demonstraram que é necessário fazer alguns ajustes na largura de pulsos, juntamente com o ciclo de fases, para minimizar as anomalias de intensidade e de fase dos sinais no espectro transformado. Essa técnica foi aplicada em espectroscopia ‘in vivo’, a qual permite resolver, por exemplo, problemas como a determinação de açúcares em frutas, onde o sinal é bastante próximo do intenso sinal da água.
In this work a study of the continuous wave free precession (CWFP), a special condition of the steady-state free precession (SSFP), and some applications, was developed. The experimental results, together with simulated ones, have shown that the CWFP signal is attained after two previous stages. The first one is dependent on the non-homogeneity of the magnetic field, related to Tp/T2* ratio. The second, which is called quasi-stationary state, is dependent of both relaxation times, T1 and T2. This second stage allows leading the magnetization in the thermal equilibrium to a truly stationary state. The information of the signal amplitude in the thermal equilibrium and in the steady state, and also the signal decaying during the quasistationary state, allows the fast and simultaneous determination of the relaxation times, performed in a single experiment. This method offers interesting applications for studying dynamical processes, also proposed in this work. It was possible to verify that the CWFP signal can be used to monitor kinetics of reactions, which variations of viscosity are involved, for example, in polymerization reactions, always associated to structural changes. A method for evaluating thermal conductivity in elastomers was proposed, with results in accordance to the literature, which uses other methods. The dependence of the CWFP signal with the offset frequency has permitted to study an application to the High-Resolution NMR, about the solvent suppression. The results demonstrated that it is necessary to perform some adjustments in the pulse width, together the phase cycle, to minimize some phase and intensity anomalies of the frequency-domain signal. This technique was applied in ‘in vivo’ spectroscopy, which can solve, for example, problems with the determination of the sugar content in fresh fruits, where the sugar signal is very close to the intense signal of the water.

Thesis of Blood, a one-act, dance-theater meta-commentary, brings conceptual, compositional, and narrative elements from the cinematic horror genre, specifically the classical and post-modern periods of the slasher film sub-genre, to the concert dance stage. The work explores how those elements can generate original choreographic material, translate into live theater through reimplementation via staging and stagecraft, and challenge standardized concert audience expectations. Thesis of Blood examines and combines the different forms of spectacle used in musical theater jazz and cinematic horror, their use of the eroticized female form, and how their different approaches and depictions of violence can reframe and question how and why the contemporary audience consumes violence as a form of entertainment.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Neste trabalho formulamos uma versão histórica sobre a formação de professores de Matemática na região do Médio Araguaia, estado de Mato Grosso, partindo do Projeto Inajá, no período de 1980 a 1990. Para desenvolvermos nossa pesquisa adotamos a História Oral como metodologia. Através dela constituímos narrativas que, juntamente com outras fontes escritas e imagéticas, nos permitiram narrar sobre a formação de professores na região, no referido período. Assim, abordamos um curso ofertado no Médio Araguaia, em uma época em que o fluxo migratório para a região estava em pleno movimento e acontecia um aumento significativo da população, necessitando assim melhorar e qualificar os professores que ali atuavam. Isso se deu por incentivo de pessoas da região que sofriam pela carência e urgência da mudança educacional. O curso ocorreu de modo inovador para atender aos professores leigos, sendo ofertado em etapas no período de férias, bem como adotou uma metodologia diferenciada que foi moldada dia a dia, conforme nossos entrevistados. O Projeto Inajá aconteceu em dois momentos distintos, atendendo mais de 300 professores leigos, ou seja, professores que já atuavam em sala de aula e não possuíam formação alguma para atuar. Por meio dos cursos desse projeto, os professores envolvidos obtiveram a formação em nível de magistério, para atuar nos anos iniciais do ensino fundamental. Cumpre lembrar que esta pesquisa faz parte de um projeto do Grupo História Oral e Educação Matemática (Ghoem), que visa a um mapeamento sobre a História da Educação Matemática Brasileira e especificamente sobre a formação e atuação de professores de Matemática em suas distintas regiões. Dessa maneira, contribui significativamente com este projeto ao mostrar que o Inajá, mesmo sendo um curso em caráter emergencial, implicou mudanças na realidade educacional das localidades envolvidas, trazendo novos elementos para a discussão sobre a formação de professores de Matemática no Brasil.
This research brings a historical version of mathematics teachers training in the region of Médio Araguaia, State of Mato Grosso, Brazil. We concentrated on Inajá Project, which took place during the decades of 1980 and 1990. In order to develop this research, we adopted the Oral History methodology. Through it, we gathered narratives that, associated with other documental sources and images, allowed us to narrate the teachers training process in the considered region and period. We focused on a course offered in Médio Araguaia when the migratory flow towards the region was big and, therefore, caused a significant growth in the population of the area. There was the need to improve and qualify the teachers who worked there. This happened with the incentive of local people, who were suffering with the lack of qualified professionals and the urgent need of educational changes. The course happened in an innovative way to serve the lay teachers, and took place during holidays. It also included an original methodology, which was determined day by day, according to the people we interviewed. Inajá Project was held in two specific periods, helping more than 300 lay teachers, who had already been teaching without appropriate formal training. After attending the courses offered by the Project, the teachers involved received a certificate to teach elementary school. It is also important to point out that this research is part of a project held by the Mathematical Education and Oral History Group (Ghoem, in Portuguese), which aims to produce a map of the history of mathematical education in Brazil. This project concentrates specifically on the training and work of mathematics teachers in different regions of the country. This research also contributes significantly to the Ghoem proposal by showing that Inajá Project, which was an emergency measure, resulted in changes in the educational reality of the region and enlightened with new information the discussion about mathematics teachers training and development in Brazil.

Le phénomène de blocage de photon est observé lorsqu'un système à deux niveaux est fortement couplé à une cavité, limitant ainsi le nombre d'occupation des photons dans le mode de la cavité à zéro ou un. Ce phénomène est analogue au blocage de Coulomb en physique mésoscopique et a été observé en optique en couplant un atome unique ou une boîte quantique à une cavité. L'efficacité du blocage, mesurée par la fonction d'autocorrélation du deuxième ordre g2(0) augmente d'autant plus que la non-linéarité du système est grande devant la largeur de la cavité. Ce travail de thèse présente l'étude théorique et expérimentale d'un nouveau phénomène de blocage appelé "phénomène de blocage anormal de photon", dans le régime micro-onde. Ce phénomène apparaît dans un système photonique comprenant deux modes couplés, où au moins un des modes est non-linéaire. Par contraste avec le blocage de photon standard, le blocage anormal permet d'obtenir un blocage parfait (g2(0)=0) pour une non-linéarité arbitrairement faible. Nous présentons les propriétés théoriques du blocage anormal, et notamment sa formulation en termes d'états gaussiens. Afin de mettre en évidence ce phénomène, nous avons réalisé deux résonateurs supraconducteurs couplés, dont l'un est rendu non-linéaire et ajustable en fréquence par l'ajout d'un SQUID. Nous montrons les techniques de fabrication employées et la caractérisation des paramètres de notre échantillon. Enfin, nous présentons les techniques mises en œuvre pour mesurer g2(t). Cette mesure nous a permis de mettre en évidence le phénomène de blocage anormal et d'en étudier les propriétés en fonction des différents paramètres expérimentaux
Photon blockade is observed when a two level system is strongly coupled to a cavity thus limiting the occupation number of the cavity mode to zero or one photon. This phenomenon is analogous to the Coulomb blockade effect in mesoscopic physics and has been observed in optics by coupling a single atom or a quantum dot to a cavity. The efficiency of the blockade, as measured by the second order auto-correlation function g2(0) increases with the non-linearity of the system in comparison to the cavity width. In this thesis, we present a theoretical and experimental study of a new blockade mechanism, called "anomalous photon blockade effect", in the microwave domain. This effect appears in photonics systems consisting of two coupled modes, where at least one of the mode is non-linear. In contrast to the standard blockade effect, perfect blockade (g2(0)=0) can be achieved with an arbitrary weak non-linearity strength. In the first part, we present a theoretical study of the anomalous blockade, and we use, in particular, a description in terms of gaussian states. To experimentally observe this effect, we have micro-fabricated two coupled superconductive resonators, where one of the resonator is frequency tunable and non-linear thanks to a SQUID. In the second part, we present the fabrication process and the characterization of our sample. Finally, we present the different techniques that we use to measure the auto-correlation function g2(τ). This measurement allowed us to demonstrate the anomalous blockade effect and to study its various properties as a function of the experimental parameters

Le modèle du jellium est l'un des modèles fondamentaux de la matière condensée.Il est constitué d'un ensemble d'électrons et d'un fond uniforme qui assure la neutralité globale.À température nulle et sans champ extérieur, la densité électronique est le seul paramètre du système.Malgré la simplicité de ce modèle, l'état fondamental du jellium en fonction de la densité reste un problème ouvert.Nous avons étudié le modèle du jellium à 2 et 3 dimensions dans l'approximation de Hartree-Fock par une méthode numérique de descente.En utilisant des états périodiques, le nombre d’inconnues est grandement réduit et le nombre d’électrons peut atteindre le million.À type de réseau et polarisation fixés, nous montrons que le système forme un cristal de Wigner à basse densité puis, au dessus d'une densité de transition, occupe des états «métalliques» caractérisés par une structure cristalline avec une maille plus petite que celle du cristal de Wigner.Les états métalliques interpolent entre le cristal de Wigner et le gaz de Fermi, ce dernier n'étant retrouvé qu'à densité infinie.Ce comportement se retrouve à deux et trois dimensions, pour un gaz polarisé et non polarisé, et pour les différents type de réseaux considérés dans nos travaux.Le diagramme de phase à deux ou trois dimensions est alors très riche et comprend à basse densité diverses phases «cristal de Wigner» avec des symétries et polarisations différentes.À haute densité, les états métalliques non-polarisées déstabilisent le cristal de Wigner et le gaz de Fermi. Ces états métalliques s’interprètent comme une superposition d’ondes de densité de spin, prédite par Overhauser en 1962
The jellium model is a fundamental model in condensed matter. It is formed by a set of electrons and a uniform background insuring global neutrality. At zero temperature and without external field, the ground-state depends only on the electronic density. Despite its simplicity, the jellium ground-state is still an open problem. We studied the jellium model in 2 and 3 dimensions within the Hartree-Fock approximation using a numerical descent method. Assuming periodic states, we greatly reduce the number of unknowns and the system may contain up to one million of electrons. At fixed lattice symmetry and polarization, the ground-state is a Wigner crystal at low density, and a «metallic state» above a critical density value. These metallic states are crystals with a lattice constant smaller than in Wigner phase, and interpolate between the latter and the Fermi gas. The metallic states exists in two and three dimensions, for a polarized and unpolarized gas, and for various lattice symmetries. Therefore, the jellium phase diagram at zero temperature is rich : it contains several Wigner crystal phases at low density, polarized and unpolarized, and an unpolarized metallic state at high density. These states are well described by a superposition of spin-density waves, as predicted by Overhauser in 1962

Aquesta tesi doctoral se centra en l’estudi teòric i numèric de sistemes fotònics amb retroacció i múltiples línies de retard, en el límit en el que els temps de retard són molt més grans que les escales de temps intrínseques del sistema. Es consideren dos sistemes òptics amb retroacció: i) dos oscilıladors optoelèctronics (OEOs) acoblats mútuament amb retard i ii) un làser de semiconductor amb retard que depèn de l’estat mitjançant el filtrat freqüencial des de dues cavitats amb diferents longituds i freqüències centrals. Tot i que els dos sistemes tenen en comú la presència de múltiples línies de retard, es tracta de dos sistemes ben diferents. En el primer, intevenen en tot moment dos temps de retard. En el segon, en canvi, la llum pren una única línia de retard a cada moment; en aquest sistema, el valor del retard és seleccionat intrínsicament per l’estat del sistema d’entre dos valors diferents mitjançant el filtrat freqüencial de la llum des de dos filtres de diferents freqüències centrals colılocats en dues cavitats de diferent longitud. D’una banda, es modelitzen aquests sistemes i es desenvolupen mètodes analítics per trobar solucions aproximades. Aquests mètodes es podrien emprar per entendre la dinàmica d’altres sistemes amb retard. D’altra banda, es comparen els resultats analítics o experimentals amb simulacions numèriques. La tesi està dividida en quatre parts. Les parts I, II i IV contenen diversos capítols, mentre que la part III està formada per un únic capítol. La part I, Introducció, objectius, eines i resultats anteriors , està dividida en tres capítols: En el Capítol 1, primer s’introdueixen alguns exemples de sistemes en els quals la presència de retards determina les propietats dinàmiques del sistema i en alguns casos origina un comportament complex. A continuació, s’introdueix el problema genèric d’un sistema amb retard i la seva modelització mitjançant equacions diferencials amb retard. S’expliquen dos exemples en detall, incloent la seva modelització amb equacions diferencials amb retard. Més endavant, s’introdueixen les ones quadrades que es poden obtenir amb sistemes d’OEOs i altres sistemes amb retard, i es presenten algunes aplicacions de les solucions tipus ona quadrada obtingudes amb OEOs, com són el control del període o la codificació d’informació. Finalment es resumeixen els objectius de la tesi. En el Capítol 2, es presenten alguns mètodes analítics i numèrics emprats en aquesta tesi, com són el mètode d’estabilitat lineal, l’estudi de l’estabilitat de solucions periòdiques, i algoritmes per integrar numèricament equacions diferencials amb retard. El Capítol 3 està dedicat a l’estudi de la dinàmica de sistemes senzills en els quals els sistemes d’estudi d’aquesta tesi estan basats: un oscilılador optoelectrònic i un làser de semiconductor amb retroacció òptica. En cada cas, es descriu el sistema en detall, s’introdueix la seva modelització mitjançant equacions diferencials amb retard, i es presenten els diferents tipus de dinàmica i possibles aplicacions. La part II està dedicada a la Sincronització en oscil·ladors optoelectrònics mú- tuament acoblats amb retard i conté quatre capítols: En el Capítol 4, es descriu el sistema de dos OEOs mútuament acoblats i amb dos temps de retard diferents, el de la retroacció i el de l’acoblament. Primer s’obtenen les equacions dinàmiques del sistema. A continuació, s’escriuen les equacions dinàmiques de manera adimensional i es troba l’estat estacionari estàtic (punt fix) del sistema. Per acabar, s’introdueix el cas d’OEOs idèntics, se simplifiquen les equacions dinàmiques i es demostra l’existència de solucions periòdiques sincronitzades en fase i en antifase a partir de l’anàlisi d’estabilitat lineal de la solució zero. El Capítol 5 se centra en la generació de solucions periòdiques quadrades mitjançant el sistema de dos OEOs idèntics mútuament acoblats descrit en el capítol 4, en el cas de retroacció negativa, la qual tendeix a reduir l’efecte de les pertorbacions de l’estat estacionari estàtic. Primer s’aplica el mètode d’estabilitat lineal per trobar el període de les solucions oscilılants en funció de la relació entre els dos temps de retard diferents. Es demostra la coexistència de múltiples solucions periòdiques de tipus ona quadrada sincronitzades en fase quan la raó entre el temps de retard intrínsec i el de l’acoblament satisfà una relació racional entre dos nombres senars. De manera similar, múltiples ones quadrades en antifase i amb diferents períodes poden coexistir quan la raó entre el temps de retard intrínsec i el de l’acoblament és un racional senar/parell. A continuació, s’apliquen mètodes assimptòtics per obtenir mapes per a l’amplada de les solucions. Es demostra que les solucions periòdiques quadrades experimenten una ruta al caos del tipus doblament de període. Després s’analitza l’efecte de canviar lleugerament els paràmetres en la forma de les solucions. Finalment, a partir del càlcul precís del període de les solucions, s’observa un fenomen de divisió del període en diferents valors. El Capítol 6 està dedicat a l’aparició de solucions quadrades estables amb el mateix model que en el Capítol 5, però en el cas de retroacció positiva, la qual tendeix a augmentar l’efecte de les pertorbacions de l’estat estacionari estàtic. Les solucions quadrades que apareixen amb retroacció positiva tenen un cicle asimètric i són més flexibles i robustes que les que s’obtenen amb retroacció negativa; en concret, l’asimetria del seu cicle permet que puguin adaptar la seva forma com a resposta a canvis en els valors dels paràmetres. Primer s’aplica l’anàlisi d’estabilitat lineal de l’estat estacionari estàtic per obtenir el període de les ones quadrades de freqüència més gran en funció de la relació entre els dos temps de retard diferents. Es demostra que el sistema té solucions sincronitzades en fase i en antifase, i que múltiples solucions poden coexistir, de manera similar al cas de retroacció negativa. No obstant això, a diferència del cas de retroacció negativa, aquí les solucions en antifase sempre coexisteixen amb solucions en fase amb diferents períodes. A més, aquest sistema té solucions periòdiques de freqüència més baixa, sincronitzades en fase i que coexisteixen amb les ones quadrades de freqüència alta per als mateixos valors dels paràmetres. A continuació, s’aplica un mètode assimptòtic per caracteritzar l’amplitud i la forma de les ones quadrades. Es demostra que el cicle de les solucions quadrades generades amb retroacció positiva es pot controlar canviant el voltatge constant aplicat als OEOs, sense que canviï el període. També s’analitza l’efecte de canviar lleugerament els valors dels paràmetres en la forma de les solucions. Es demostra que les ones quadrades generades amb retroacció positiva són més robustes a canvis en els valors dels paràmetres. Finalment, a partir del càlcul precís del període de les solucions, s’observa un fenomen de divisió del període en diferents valors. En el Capítol 7, s’estudia el cas de dos oscilıladors no-idèntics, incloent les possibilitats de retroacció negativa, positiva i mixta. Es demostra que aquest sistema pot generar múltiples solucions de tipus ona quadrada, amb diferents tipus de sincronització (en fase, en antifase i a un quart del període) depenent del signe de la retroacció de cada oscilılador. Les ones quadrades amb sincronització a un quart del període apareixen principalment quan la retroacció és negativa per a un oscilılador i positiva per a l’altre. Finalment, s’analitza la robustesa de les solucions sincronitzades a un quart del període a petits canvis en els valors dels paràmetres. La part III se centra en el tema Sistemes fotònics amb retards que depenen de l'estat i està formada per un capítol: En el Capítol 8, es considera un sistema de làser de semiconductor amb filtrat freqüencial des de dues cavitats de longituds i freqüències centrals diferents, com a model per a estudiar la dinàmica d’un sistema amb retard que depèn de l’estat. Primer s’introdueix el disseny experimental, que està basat en un làser de semiconductor i dos filtres de Bragg amb diferents freqüències centrals colılocats en dues cavitats de diferents longituds, i per tant associats a dos temps de retard diferents. Es demostra que la dinàmica d’aquest sistema es caracteritza per salts erràtics entre els dos valors del temps de retard. A continuació, s’introdueix un model teòric amb filtrat lorentzià des de dues cavitats diferents. Es calculen les solucions estacionàries i s’analitza la dinàmica erràtica amb retard que depèn de l’estat per a diferents valors dels paràmetres. Es demostra que els resultats numèrics en el règim erràtic coincideixen qualitativament amb els experiments. També es demostra que aquest sistema té solucions més regulars, similars a les ones quadrades periòdiques, amb retard que depèn de l’estat. Finalment, s’analitza l’estadística dels temps de residència durant els quals el retard pren un valor constant. La part IV, Resum i perspectives de treball, conté dos capítols de conclusions: el Capítol 9, corresponent a la part dels OEOs; i el Capítol 10, referit a la part dels retards depenents de l’estat. En aquests capítols es resumeixen els principals resultats obtinguts i es proposen algunes perspectives per a futures investigacions.
Esta tesis doctoral se centra en el estudio teórico y numérico de sistemas fotónicos con realimentación y múltiples líneas de retardo, en el límite en el que los tiempos de retardo son mucho más grandes que las escalas de tiempo intrínsecas del sistema. Se consideran dos sistemas ópticos con realimentación: i) dos osciladores optoelectrónicos (OEOs) mutuamente acoplados con retardo y ii) un láser de semiconductor con retardo dependiente del estado mediante el filtrado frecuencial desde dos cavidades con diferentes longitudes y frecuencias centrales. Aunque estos dos sistemas tienen en común la presencia de múltiples líneas de retardo, se trata de dos sistemas bastante diferentes. En el primero en todo momento intervienen dos tiempos de retardo. En el segundo, en cambio, la luz toma una única línea de retardo en cada momento; en este sistema, el valor del retardo es seleccionado intrínsicamente por el estado del sistema entre dos valores diferentes mediante el filtrado frecuencial de la luz desde dos filtros con diferentes frecuencias centrales colocados en dos cavidades de diferente longitud. Por un lado, se modelizan estos sistemas y se desarrollan métodos analíticos para encontrar soluciones aproximadas. Estos métodos podrían utilizarse para comprender la dinámica de otros sistemas con retardo. Por otro lado, se contrastan los resultados analíticos o experimentales con simulaciones numéricas. La tesis está dividida en cuatro partes. Las partes I, II y IV contienen varios capítulos, mientras que la parte III está formada por un solo capítulo. La parte I, Introducción, objectivos, herramientas y resultados anteriores , está dividida en tres capítulos: En el Capítulo 1, primero se introducen algunos ejemplos de sistemas en los cuales la presencia de retardos determina las propiedades dinámicas del sistema, en algunos casos dando lugar a comportamiento complejo. A continuación se presenta el problema general de un sistema con retardo y su modelización con ecuaciones diferenciales con retardo. Se explican dos ejemplos en detalle, incluyendo su modelización con ecuaciones diferenciales con retardo. Luego se introduce el régimen dinámico de oscilación periódica de tipo onda cuadrada que se puede obtener con OEOs y otros sistemas con retardo, y se resaltan algunas aplicaciones de estas ondas cuadradas, como el control del período y la codificación de información. El capítulo termina con un resumen de los objetivos de la tesis. En el Capítulo 2, se introducen algunos métodos numéricos y teóricos usados en esta tesis, como el análisis de estabilidad lineal, métodos y herramientas para el estudio de la estabilidad de soluciones periódicas, y algoritmos para integrar numéricamente las ecuaciones diferenciales con retardo. El Capítulo 3 está dedicado al estudio de la dinámica de sistemas sencillos en los que se basan los sistemas estudiados en esta tesis: un único OEO y un láser de semiconductor con realimentación óptica. En cada caso, se describe en detalle el sistema, se introduce su modelización con ecuaciones diferenciales con retardo, y se presentan sus diferentes regímenes dinámicos y posibles aplicaciones. La parte II está dedicada a la Sincronización en osciladores optoelectrónicos mutuamente acoplados con retardo y contiene cuatro capítulos: En el Capítulo 4, se describe el sistema de dos OEOs mutuamente acoplados y con dos tiempos de retardo diferentes, el de la propia realimentación y el del acoplamiento. Primero se derivan las ecuaciones dinámicas del sistema. A continuación se escriben las ecuaciones dinámicas en forma adimensional y se calcula la solución estacionaria estática (punto fijo) del sistema. Finalmente se introduce el caso de OEOs idénticos, se simplifican las ecuaciones dinámicas y se demuestra que el análisis de estabilidad lineal de la solución cero da lugar a soluciones periódicas sincronizadas en fase y en antifase. El Capítulo 5 se centra en la generación de pulsos simétricos de onda cuadrada mediante el sistema de dos OEOs idénticos mutuamente acoplados con retardo descrito en el capítulo 4, en el caso de realimentacion negativa, la cual tiende a reducir el efecto de las perturbaciones del estado etacionario estático. Primero se aplica el método de estabilidad lineal para obtener el período de las soluciones oscilatorias en función de la relación entre los dos tiempos de retardo diferentes. Se demuestra que múltiples soluciones periódicas de tipo onda cuadrada en fase coexisten cuando la razón entre el tiempo de retardo intrínseco y el del acoplamiento satisface una relación racional entre dos números impares. De manera similar, múltiples ondas cuadradas en antifase con diferentes períodos pueden coexistir cuando la razón entre el tiempo de retardo intrínseco y el del acoplamiento es un racional impar/- par. A continuación, se aplican métodos asintóticos para obtener mapas para la amplitud de las soluciones. Se demuestra que las ondas cuadradas periódicas experimentan una ruta al caos del tipo doblamiento de período. Después se analiza el efecto de cambiar ligeramente los valores de los parámetros en la forma de las soluciones. Finalmente, a partir del cálculo preciso del período de las soluciones, se observa un fenómeno de división del período en diferentes valores. El Capítulo 6 está dedicado a la aparición de pulsos de onda cuadrada estables con el mismo modelo que en el Capítulo 5 pero en el caso de realimentación positiva, la cual tiende a aumentar el efecto de las perturbaciones del estado etacionario estático. Las ondas cuadradas que surgen con realimentación positiva tienen un ciclo asimétrico y son más flexibles y robustas que las obtenidas con realimentación negativa; en particular, la asimetría de su ciclo les permite adaptar su forma en respuesta a cambios en los valores de los parámetros en vez de experimentar un doblamiento de período. Primero se aplica el análisis de estabilidad lineal del estado estacionario estático para obtener el período de las ondas cuadradas de mayor frecuencia en función de la relación entre los dos tiempos de retardo diferentes. Se demuestra que el sistema tiene soluciones sincronizadas en fase y en antifase, y que múltiples soluciones pueden coexistir, de manera similar al caso de realimentación negativa. Sin embargo, a diferencia del caso de realimentación negativa, aquí las soluciones en antifase siempre coexisten con soluciones en fase con diferentes períodos. Además, este sistema tiene soluciones periódicas de menor frecuencia, sincronizadas en fase y coexistiendo con las soluciones cuadradas rápidas para los mismos valores de los parámetros. A continuación se aplica un método asintótico para determinar la amplitud y forma de las ondas cuadradas. Se demuestra que el ciclo de las ondas cuadradas generadas con realimentación positiva se puede controlar cambiando el voltaje constante aplicado a los OEOs, manteniendo el período constante. También se analiza el efecto de variar ligeramente los valores de los parámetros en la forma de las soluciones. Se demuestra que las ondas cuadradas generadas con realimentación positiva son más robustas frente a cambios en los valores de los parámetros que las obtenidas con realimentación negativa. Finalmente, a partir del cálculo preciso del período de las soluciones, se demuestra que el período de las soluciones se divide en diferentes valores. En el Capítulo 7, se considera el caso de OEOs no idénticos, incluyendo las posibilidades de realimentación negativa, positiva y mixta. Se demuestra que este sistema puede generar múltiples ondas cuadradas, con diferentes tipos de sincronización (en fase, en antifase y a un cuarto del período) dependiendo del signo de la realimentación de cada oscilador. Las ondas cuadradas con sincronización a un cuarto del período aparecen principalmente cuando la realimentación es negativa para un oscilador y positiva para el otro. Finalmente se analiza la robustez de las soluciones sincronizadas a un cuarto del período frente a pequeños cambios en los valores de los parámetros. La parte III se centra en el tema Sistemas fotónicos con retardos que dependen del estado y está formada per un único capítulo: En el Capítulo 8, se considera un sistema de láser de semiconductor con filtrado frecuencial desde dos cavidades de longitudes y frecuencias centrales diferentes, como prototípico para estudiar la dinámica de un sistema con retardo que depende del estado. Primero se introduce el diseño experimental, basado en un láser de semiconductor con realimentación filtrada desde dos filtros de Bragg con diferentes frecuencias centrales y situados en dos cavidades de diferetes longitudes, y por lo tanto asociados a diferentes tiempos de retardo. Se demuestra que la dinámica de este sistema se caracteriza por saltos erráticos entre los dos valores del tiempo de retardo. A continuación se introduce un modelo teórico con filtrado lorenciano desde dos cavidades diferentes. Se calculan las soluciones estacionarias y se analiza la dinámica errática con retardo que depende del estado para diferentes valores de los parámetros. Se demuestra que los resultados numéricos en el régimen errático concuerdan de forma cualitativa con los resultados experimentales. También se demuestra que este sistema tiene soluciones más regulares, similares a las ondas cuadradas, con retardo dependiente del estado. Finalmente se analiza la estadística de los tiempos de residencia durante los que el retardo toma un valor constante. La parte IV, Resumen y perspectivas de trabajo , contiene dos capítulos de conclusiones: el Capítulo 9, correspondiente a la parte de los OEOs; y el Capítulo 10, referido a la parte de sistemas fotónicos con retardos dependientes del estado. En estos capítulos, se resumen los principales resultados obtenidos y se proponen algunas perspectivas de trabajo para futuras investigaciones.
This PhD thesis focuses on the theoretical and numerical study of photonic systems with feedback from multiple delay lines, in the limit in which the delay times are much longer than the intrinsic time scales of the system. Two optical systems with feedback are considered: i) two mutually delay-coupled optoelectronic oscillators (OEOs) and ii) a semiconductor laser with a delay time that depends on the state of the system via the filtered feedback from two cavities with different length and central frequency. Although these two systems have in common the presence of multiple delay lines, they are indeed quite different. In the former, two different delay times take part at any time. In the latter, in contrast, light takes a single delay line at any time; in this system, the delay time value is intrinsically selected among two different values by the state of the system since the frequency of light is selectively filtered by using two filters of different central frequencies placed in two cavities of different lengths. On the one hand, these systems are modelled and analytical methods are developed to find approximate solutions. These methods could be used to understand the dynamics of other systems with delay. On the other hand, extensive numerical simulations are compared to analytical or experimental results. The thesis is divided into four parts. Parts I, II and IV contain several chapters, whereas part III has a single chapter. Part I, Introduction, objectives, tools and previous results , is divided in three chapters: In Chapter 1, some examples of systems in which the presence of delays determines the dynamical properties of the system, often giving rise to complex behavior, are first introduced. After that, the generic problem of a system with delay and its modelling with delay differential equations is presented. Two examples are explained in detail, including their modelling with delay differential equations. Then, the square-wave periodic regime that can be obtained with OEOs and other systems with delay is introduced, and some applications of the square-wave regime are highlighted, such as the control of the period and information encoding. The chapter ends with a summary of the objectives of the thesis. Chapter 2 introduces some analytical and numerical methods and tools used in this thesis, such as the linear stability analysis, methods and tools for the study of the stability of periodic solutions, and algorithms to integrate numerically delay differential equations. Chapter 3 is devoted to the study of the dynamics of simple systems in which the systems studied in this thesis are based: a single OEO and a semiconductor laser with optical feedback. In each case, the system is described in detail, its modelling with delay-defferential equations is introduced, and its different dynamical regimes and possible applications are presented. Part II is devoted to the Synchronization in mutually delay-coupled optoelec- tronic oscillators and contains four chapters: Chapter 4 describes the system of two mutually delay-coupled OEOs with two different delay times, the self-feedback delay time and the coupling delay time. First, the dynamical equations of the system are derived. After that, the equations are writen in non-dimensional form and the steady state (fixed point) of the system is found. Finally, the case of identical OEOs is introduced, the dynamical equations are simplified and it is shown that the linear stability analysis of the zero solution gives rise to periodic solutions synchronized in phase and out of phase. Chapter 5 focuses on the generation of symmetric square-wave pulses by the system of two identical mutually delay-coupled OEOs described in Chapter 4, in the case of negative feedback, which tends to reduce the effect of the perturbations of the steady state solution. First, linear stability analysis is applied to obtain the period of the solutions as a function of the ratio between the two different delay times. It is shown that multiple in-phase square waves with different periods can coexist when the ratio between the self-feedback and the cross-feedback delay times satisfies a rational relationship involving two odd numbers. Similarly, multiple outof- phase square waves with different periodicity can coexist when the ratio between the self- and the cross-delay times is an odd/even rational. After that, asymptotic methods are applied to obtain maps for the amplitude of the solutions. It is found that the symmetric square-wave periodic solutions undergo a period doubling route to chaos. Then, the effect of the parameter mismatch in the form of the solutions is analyzed. Finally, a splitting of the period in different values is demonstrated by performing a precise calculation of the period of the solutions. Chapter 6 is devoted to the emergence of stable square-wave pulses with the system described in Chapter 4 in the case of positive feedback, which tends to amplify the effect of the perturbations of the steady state solution. The square waves arising with positive feedback have an asymmetric duty cycle and turn out to be more flexible and robust than those obtained with negative feedback; in particular, the asymmetry of their duty cycle allows them to adapt their shape in response to changes in the parameter values instead of undergoing a period doubling. First, the linear stability analysis of the steady state is applied to obtain the period of the oscillatory solutions as a function of the two different delay times. It is shown that the system has stable in- and out-of-phase synchronized solutions, and that several solutions can coexist, similarly to the case of negative feedback. Nevertheless, in contrast to the negative feedback case, here out-of-phase solutions always coexist with in-phase solutions with different periods. Furthermore, this system has limit cycles of lower frequency, synchronized in phase and coexisting with the aforementioned fast square waves for the same values of the parameters. After that, an asymptotic method is applied to determine the amplitude and the shape of the square waves. It is shown that the duty cycle of the square waves generated with positive feedback can be tuned with the constant voltage applied to the OEOs, while the total period remains constant. The effect of the parameter mismatch on the form of the solutions is also analyzed. It is found that the square waves generated with positive feedback are more robust to parameter mismatch than those obtained with negative feedback. Finally, a splitting of the period in different values is demonstrated by performing a precise calculation of the period of the solutions. Chapter 7 addresses the case of two non-identical OEOs, including the possibilities of negative, positive, and mixed feedback. It is shown that this system can generate multiple square-wave solutions, with different kinds of synchronization (in-phase, out-of-phase, or at a quarter of the period) depending on the sign of the feedback on each oscillator. The square waves with synchronization at a quarter of the period mainly appear when the feedback is negative for one oscillator and positive for the other one. Finally, the robustness of the solutions synchronized at a quarter of the period to parameter mismatch is analyzed. Part III focuses on the topic Photonic systems with state-dependent delays and contains a single chapter: In Chapter 8, a semiconductor laser system with frequency filtering from two cavities of different lengths and central frequencies is considered as prototypical to study the dynamics of a system with state-dependent delay. First, the experimental setup is presented. It is based on a semiconductor laser with filtered feedback from two Bragg filters of different central frequencies placed in two cavities of different lengths, and thus associated to different delay times, experiencing erratic jumps between the two delay-time values. Then, a theoretical model with lorentzian filtering from different cavities is introduced. The stationary solutions are calculated and the erratic dynamics with state-dependent delay is analyzed for different parameter values. It is shown that numerical results in the erratic regime are in qualitative agreement with the experiments. It is also shown that this system has more regular solutions, similar to the square waves, with state-dependent delay. Finally, the switching statistics is analyzed from the residence times during which the delay time remains constant. Part IV, Summary and future work , contains two concluding chapters: Chapter 9, corresponding to the part of OEOs; and Chapter 10, associated to the part of photonic systems with state-dependent delays. In these chapters, the main results are summarized and some perspectives of future work are proposed.

Formation of charge density waves (CDW) is a symmetry breaking phenomenon found in electronic systems, which is particularly common in quasi-one-dimensional conductors. It is widely observed from highly anisotropic materials to isotropic ones like the superconducting pnictides. The CDW is seen as a sinusoidal deformation of coupled electronic density and lattice modulation; it can be also viewed as a crystal of singlet electronic pairs. In the CDW state, the elementary units can be readjusted by absorbing or rejecting pairs of electrons. Such a process should go via topologically nontrivial configurations: solitons and dislocations - the CDW vortices. An experimental access to these inhomogeneous CDW states came from studies of nano-fabricated mesa-junctions, from the STM and from the X-ray micro-diffraction. Following these requests, we have performed a program of modeling stationary states and of their transient dynamic for the CDW in restricted geometries under applied voltage or at passing normal currents. The model takes into account multiple fields in mutual nonlinear interactions: the two components of the CDW complex order parameter, and distributions of the electric field, the density and the current of normal carriers. We were using the Ginzburg-Landau type approach and also we have derived its extension based on the property of the chiral invariance. We observed the incremental creation of static dislocations within the junctions. The transient dynamics is very rich showing creation, annihilation and sweeping of multiple vortices. The dislocations cores concentrate the voltage drops thus providing self-tuned microscopic junctions where the tunneling creation of electron-hole pairs can take place. The results obtained from this model agree with experiment observations. The methods can be extended to other types of charge organization known under the general name of the Electronic Crystal. It takes forms of Wigner crystals at hetero-junctions and in nano-wires, CDWs in chain compounds, spin density waves in organic conductors, and stripes in doped oxides. The studied reconstruction in junctions of the CDW may be relevant also to modern efforts of the field-effect transformations in strongly correlated materials with a spontaneous symmetry breaking.

Ce travail traite trois sujets d'etudes structurelles et dynamiques des systemes a onde de densite de charge : premierement, l'origine du comportement non-debye de la chaleur specifique des composes k#o#. #3moo#3 et kcp est etudiee. Dans ces deux composes, ce comportement anormal est observe aux temperatures voisines de 10k. La combinaison de la densite d'etats de phonons, obtenue experimentalement, avec des calculs simples, a base de courbes de dispersion de phonons, permet d'etablir le lien entre les branches acoustiques et optiques de basse energie de ces composes et l'anomalie de leur chaleur specifique. Dans une deuxieme partie, l'influence d'un faible dopage isoelectronique (nb) sur le vecteur de modulation de l'onde de densite de charge (odc) du compose (tase#4)#2i est etudiee. Contrairement aux systemes a odc prototypes comme k#o#. #3moo#3, nbse#3 ou kcp, (ta#1#-#xnb#xse#4)#2i revele un changement de la position des satellites : a partir d'un dopage avec x0. 01 les satellites s'approchent des raies de bragg. Un modele developpe recemment pour la transition de phase de(tase#4)#2i offre un mecanisme expliquant l'effet du dopage en termes d'un reseau perturbe par des defauts. Cependant, le caractere seuil de l'effet du dopage sur la variation de la position des satellites reste inexplique. Troisiemement, la deformation de l'odc depiegee par un champ electrique est etudiee dans le compose nbse#3. Cette deformation se manifeste par un changement q(x) du vecteur d'onde de l'odc le long de l'echantillon. En appliquant un champ electrique continu, la deformation est maximale au contact, suivie par un regime de decroissance exponentielle de q(x) pres du contact. Un deuxieme regime est observe dans la partie centrale de l'echantillon presentant une variation lineaire de q(x). En appliquant un champ electrique pulse, la deformation de l'odc revele dans le regime exponentiel une relaxation avec une forte dependance spatiale, pendant que dans le regime lineaire q(x) ne presente pas de dependance temporelle. Nos resultats ont permis de developper un modele theorique, reliant la deformation de l'odc au desequilibre local des porteurs de charge provoque par l'injection/l'extraction du courant electrique. Ce desequilibre est reduit par le phase slip, menant, dans un cas simple, a une dependance spatiale exponentielle de q(x). Le regime lineaire de la deformation est interprete comme la consequence d'un piegeage collectif du phase slip quand le desequilibre a diminue au-dessous d'une valeur seuil.

Les interactions entre les modes lents et les modes rapides de la circulation atmospherique sont examinees a travers deux problemes. Le premier concerne le couplage entre les ondes de gravite et les ondes de rossby. En raison des erreurs d'observation, les modeles de prevision numerique engendrent des ondes de gravite rapides irrealistes. Ces modes doivent donc etre initialement filtres. Le probleme est aborde de maniere theorique par l'etude de l'existence et des proprietes d'une variete invariante de l'espace des phases, appelee "variete lente", qui est sensee contenir l'attracteur du systeme atmospherique. Nous montrons au moyen d'exemples et de theoremes mathematiques qu'une telle variete peut exister, mais que les algorithmes actuels ne convergent pas vers elle. Le deuxieme probleme concerne la generation de la variabilite basse-frequence de l'atmosphere. Nous montrons que la dynamique lente de grande echelle est largement gouvernee par le forcage qu'induisent les transitoires rapides de petite echelle. L'existence de plusieurs structures de grande echelle associees a des regimes de temps, maintenues par les ondes baroclines rapides venant se superposer, est demontree dans le cadre d'un modele quasi-geostrophique. L'alternance entre ces regimes contribue a l'essentiel de la variabilite basse-frequence aux latitudes temperees. Cette notion de "regime de temps", jusqu'ici definie de maniere vague, est abordee de facon quantitative et objective au moyen d'une methode variationnelle statistico-dynamique. Celle-ci permet la reconnaissance de plusieurs types de circulation persistante dont l'une constitue le phenomene de "blocage". Dans ce phenomene, nous montrons que les transitoires ont un effet positif et important pour le maintien de la structure de l'anomalie

Le contrôle de la différence de fréquence entre deux lasers est un défi transversal à de nombreux domaines de la photonique, que ce soit dans un but de génération hétérodyne d'un battement micro-onde de grande pureté, ou pour des expériences de métrologie ou de télécommunication. L'avancée des connaissances sur la dynamique de lasers soumis à divers couplages a permis le développement de méthodes de stabilisation basées sur l'injection optique. Nous étudions ici théoriquement et expérimentalement un mécanisme appelé réinjection décalée en fréquence (RDF), qui permet dans des situations variées de contrôler précisément la différence de fréquence entre deux lasers. Dans un premier temps, la méthode RDF est appliquée à un laser à état solide bi-polarisation bi-fréquence Nd:YAG afin de verrouiller en phase ses deux modes de polarisation orthogonaux. Le développement d'un modèle type «rate equations» en bonne adéquation avec les expériences a aussi permis de mettre en lumière un certain nombre de régimes de synchronisation partielle dits de phase bornée. De plus, nous montrons que cet état peut subsister en présence d'oscillations chaotiques de l'intensité et de la phase. Le comportement du laser sous RDF est étudié pour différentes valeurs du désaccord de fréquence, du taux d'injection, du retard éventuel, et du couplage inter-modes. Enfin, la nécessité d'inclure un couplage phase-amplitude (facteur de Henry non-nul) dans le modèle a mené au développement d'une méthode pour mesurer ce coefficient habituellement négligé dans les lasers solides. Le mécanisme de stabilisation par RDF est ensuite appliqué à un composant semiconducteur original contenant deux lasers DFB sur InP. Malgré une plus grand complexité du schéma de couplage, et la présence de retards effectifs importants, il reste possible de synchroniser en phase ces lasers. Des bandes d'accrochages liées au retard sont observées, et reproduites à l'aide d'un modèle numérique. Ce dernier permet aussi de déterminer les conditions de fonctionnement minimisant l'influence de paramètres expérimentaux non maîtrisés. Enfin, ce système, permettant de contrôler une phase micro-onde sur porteuse optique, peut être intégré dans une boucle résonante de type oscillateur opto-électronique (OEO) qui ne nécessite pas de référence externe. On réalise un oscillateur micro-onde sur porteuse optique auto-référencé, à bande latérale unique, ayant des performances encourageantes. Dans ce cadre, il semble que la plupart des techniques développées pour les OEO puissent être réinvesties
The control of the frequency difference between two lasers is a cross-cutting challenge in many fields of photonics, either for the generation of high-purity heterodyne microwave beatnotes, or in metrology and telecommunication experiments. The advances of the comprehension of laser dynamics under various couplings has allowed to develop stabilization methods based on optical injection. We study here theoretically and experimentally a mechanism called frequency-shifted feedback (FSF), which allows to precisely control the frequency difference between two lasers in several situations.First, the FSF method is applied to a dual-frequency dual-polarization solid-state Nd:YAG laser, in order to lock the phases of its two orthogonal polarization modes. A model of rate equations is used to precisely describe the experiment, and allows to highlight partial "bounded phase" synchronization regimes. Furthermore, we show that in some cases this synchronization can subsist even with chaotic oscillations of the intensity and phase. The behavior of the laser under FSF is studied for varying values of the frequency detuning, injection rate, possible injection delay, and mode coupling in the active medium. Finally, we find that the inclusion of a phase-amplitude coupling (non-zero linewidth enhancement factor) is needed in the model to account for experimental observation. This leads to the development of an ad-hoc technique to measure the low value of this usually neglected factor in solid-laser lasers.The FSF stabilization mechanism is then applied to a custom semiconductor component embedding two DFB lasers overs InP. In spite of a more complex coupling scheme and the large effective delays into play, phase locking of the two lasers is possible. Due to the delay, locking bands appear when the detuning changes, and this behavior can be replicated using a numerical model. This model also permit to determine working conditions minimizing the influence of uncontrolled experimental optical feedback phases. Finally, as this system allows to control a microwave phase over an optical carrier, it can be integrated in a resonant loop not unlike an opto-electronic oscillator (OEO). We realized an oscillator generating a self-referenced, single sideband microwave signal over an optical carrier, with encouraging phase noise performances. In this case, it seems that most of the techniques that exist for standard OEO can be reused

Description spatiale des structures convectives dans l'instabilite de cisaillement elliptique d'un nematique. Analyse geometrique du desordre par analogie avec la cristallographie bidimensionnelle: etude des defauts dans la structure en rouleaux et de la desorganisation de la structure bidimentionnelle; etude de la propagation des ondes de gravite en eau peu profonde sur des fonds variables

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Fazemos uma revisão detalhada de alguns fundamentos básicos do formalismo de Du n- Kemmer-Petiau (DKP). Analisamos as consequências sobre o potencial matricial V para fornecer uma quadricorrente conservada. Também analisamos o comportamento das intera ções vetoriais mínimas e não mínimas sob as transformações de paridade, conjugação de carga e reversão temporal. A ambiguidade do acoplamento eletromagnético (interação vetorial mínima) também é revisada em detalhe. Algums conceitos errados sobre hermiticidade e valores esperados na teoria de DKP difundidos na literatura são discutidos. Além disso, neste trabalho desenvolvemos uma forma alternativa de procurar soluções analíticas da equação de DKP tridimensional (setor spin-0) para o caso de acoplamentos vetoriais (mínimo e não-mínimo). Considerando potenciais com simetria esférica, o problema pode ser mapeado num problema de Sturm-Liouville (da mecânica quântica não relativística) para um dos componentes do espinor de DKP. Neste processo a quadricorrente, a condição de normalização e valores esperados também podem ser expressos em termos desse componente do espinor de DKP de uma forma simples. Como uma aplicação do método desenvolvido, consideramos uma forma linear para os acoplamentos vetoriais.
A detailed review of some basics fundamentals of the Du n-Kemmer-Petiau (DKP) formalism is made. The consequences on the potential matrix V for furnish a conserved four-current are analyzed. We also analyze the behavior of minimal and nonminimal vector interactions under parity transformation, charge conjugation and time reversal. The ambiguity of the electromagnetic coupling (minimal vector interaction) is also reviewed in detail. Some misconceptions about the hermiticity and expectation values of the DKP theory widespread in the literature are discussed. In addition, an alternative way to search for analytical solutions of the DKP equation in (3+1) dimensions (spin-0 sector) in the case of vector coupling (minimal and nonminimal) is developed. Considering potentials with spherical symmetry, the problem can be mapped into a Sturm-Liouville problem (nonrelativistic quantum mechanics) for one of the components of the DKP spinor. In this process, the four-current, normalization condition and expectation values can also be expressed in terms of that component of the DKP spinor in a simple way. As an application of the developed method, we consider a linear form for the vector couplings.

Um novo procedimento para construir os estados coerentes (CS) e os estados semiclássicos (SS) no campo de um magnético-solenóide é proposto. A idéia principal é baseada sobre o fato de que o AB solenóide quebra a simetria translacional no plano-xy, isto apresenta um efeito topológico tal que surgem dois tipos de trajetórias, aquelas que circundam e aquelas que não circundam o solenóide. Devido a este fato, deve-se construir dois tipos diferentes dos CS/SS, os quais correspondem as referidas trajetórias no limite semiclássico. Seguindo esta idéia, construímos os CS em duas etapas, primeiro os CS instantâneos (ICS) e os CS/SS dependentes do tempo como uma evolução dos ICS. A construção é realizada para partículas não-relativísticas e relativísticas, de spin-zero e com spin ambas em (2 + 1)- e (3 + 1)- dimensões e gera um exemplo não-trivial de SS/CS para sistemas com uma Hamiltoniana não-quadrática. É enfatizado que os CS dependendo dos seus parâmetros (números quânticos), descrevem ambos os estados puramente quânticos e semiclássicos. Uma análise é representada de modo que classifica os parâmetros dos CS em tal relação. Tal classificação é usada para as decomposições semiclásicas de diversas quantidades físicas.
A new approach to constructing coherent states (CS) and semiclassical states (SS) in magnetic-solenoid field is proposed. The main idea is based on the fact that the AB solenoid breaks the translational symmetry in the xy-plane, this has a topological effect such that there appear two types of trajectories which embrace and do not embrace the solenoid. Due to this fact, one has to construct two different kinds of CS/SS, which correspond to such trajectories in the semiclassical limit. Following this idea, we construct CS in two steps, first the instantaneous CS (ICS) and the time dependent CS/SS as an evolution of the ICS. The construction is realized for nonrelativistic and relativistic, spinning and spinless particles both in (2 + 1)- and (3 + 1)- dimensions and gives a non-trivial example of SS/CS for systems with a nonquadratic Hamiltonian. It is stressed that CS depending on their parameters (quantum numbers) describe both pure quantum and semiclassical states. An analysis is presented that classifies parameters of the CS in such respect. Such a classification is used for the semiclassical decompositions of various physical quantities.

Esta tese apresenta uma nova aproximação variacional baseada no Método da Coordenada Geradora e na Teoria do Funcional da Densidade. Nesta nova aproximação, a função de onda de muitos corpos é representada como uma superposição de determinantes de Slater Kohn-Sham não-ortogonais calculados a partir de Hamiltonianos diferentes que carregam uma coordenada geradora atuando como parâmetro de deformação. A discretização integral sobre o conjunto de coordenadas geradoras fornece a energia total variacional do sistema e a contribuição de cada determinante na combinação da respectiva função de onda de muitos corpos. A flexibilidade desta nova metodologia permitiu aplicá-la no estudo das energias totais do estado fundamental e excitado dos átomos da série isoeletrônica do Hélio, utilizando diferentes conjuntos de coordenadas geradoras, diferentes aproximações para o potencial de troca e correlação e diferentes maneiras de implementar a coordenada geradora dentro do Hamiltoniano Kohn-Sham. Em seguida, as bases desta nova metodologia foram estendidas para o caso dependente do tempo, permitindo estudar, por exemplo, processos não-lineares como excitações duplas, conhecidas por sua forte dependência dos efeitos de memória. A nova metodologia foi aplicada no estudo das oscilações paramétricas de um sistema de dois elétron sob um potencial harmônico, o átomo de Hooke. Os resultados demonstram que a escolha adequada das coordenadas geradoras reproduz com precisão os efeitos lineares e não-lineares dos elétrons do sistema que não podem ser descritos pela Teoria do Funcional da Densidade Dependente do Tempo utilizando a aproximação adiabática. Assim, a nova metodologia mostra-se: flexível, pois permite calcular propriedades do estado fundamental e excitado, estáticas e dinâmicas dos sistemas eletrônicos fornecendo ainda uma aproximação variacional para as respectivas funções de onda de muitos corpos em todos os casos; e também viável, pois fornece resultados promissores no caso independente do tempo constituindo uma ferramenta simples e computacionalmente barata de incluir os efeitos de memória em qualquer aproximação adiabática no caso dependente do tempo.
A new variational approach based on the Generator Coordinate Method and Density- Functional Theory is presented. It represents the interacting many-body wave function as a superposition of non-orthogonal Kohn-Sham Slater determinants arising from different Hamiltonians featuring a generator coordinate acting as a deformation parameter. An integral discretization procedure over the set of generator coordinates provides the variational total energy of the system and the weight of each determinant in the approximation of the respective interacting many-body wave functions. The method was used to calculate the ground and excited state total energies of the Helium isoelectronic serie of atoms using different sets of generator coordinates, different approximations to the exchange-correlation potential and different implementations of the generator coordinate whithin the Kohn-Sham Hamiltonian. Next, the time dependent extension of the method is presented allowing its application, for example, on the study of nonlinear processess as double excitations which are known to be strongly dependent of the memory effects. As an illustration, the method is sucessfully applied to driven parametric oscillations of a two interacting electrons in a harmonic potential, the Hooke\'s atom. It is demonstrated that a proper choice of time-dependent generator coordinates in conjunction with the adiabatic local-density approximation reproduces the exact linear and nonlinear twoelectron dynamics quite accurately, including features associated with double excitations that cannot be captured by Time-Dependent Density-Functional Theory in the adiabatic approximation. Therefore, the method is considered, flexible since it allows to calculate ground and excited-states, static and dynamic properties of the electronic systems yeilding a variational approach to the interacting many-body wave functions for all cases, and feasible, since it improves the results for ground and excited-states total energies in the time-independente case, besides to be a conceptually and computationally simple tool to build memory effects into any existing adiabatic exchange-correlation potential in the time-dependent case.

Interpretation de l'abaissement de la pression de fusion lorsque la fusion est plus rapide que le temps de relaxation de la polarisation de **(3)he d'apres l'etude theorique de la morphologie de l'interface liquide-solide lors de la fusion de **(3)he solide polarise. Tendance au metamagnetisme de **(3)he liquide pour une polarisation de equiv. A 20 %, a 0,1 k, et absence d'anomalie dans la vitesse du son mesuree a ce taux de polarisation. Possibilite de refroidir le liquide polarise au-dessus de 0,1 k en un temps tres court compare a celui de la relaxation de polarisation. Etude experimentale des proprietes magnetoelastiques de composes a deux fermions lourds et analyse phenomenologique pour prevoir la magnetostriction, la vitesse du son sous champ magnetique de ces composes pesentant une forte tendance au metamagnetisme, et, aux frequences grandes comparees au taux de relaxation de la polarisation, la vitesse du son

Mesure des coefficients d'attenuation des elements de numero atomique 46 a 54 dans le domaine 15 a 45 kev. Determination des parametres de la loi de variation empirique du coefficient d'attenuation en fonction de la longueur d'onde du rayonnement. Determination des facteurs de diffusion anomale vers l'avant, en utilisant la relation de dispersion

L'epitaxie en phase liquide a permis de realiser des guides planaires emettant a temperature ambiante autour de 2 microns. Les materiaux etudies ont ete le yag (y3al5o12) et le yso (y2sio5) dopes par un ion terre rare tm3+. Ce memoire decrit les conditions necessaires pour l'obtention de couches de bonne qualite. Il met notamment en avant le fait que les conditions de croissance du yso sont beaucoup plus severes que celles du yag (plage de sursaturation plus petite, vitesse de croissance plus faible). Les differentes caracterisations effectuees ont montre la qualite des guides realises, notamment les performances laser qui ont ete obtenues. Les resultats obtenus pour le yag:tm confirment la bonne adaptation des guides a un pompage par diode. Un effet laser a ete obtenu pour les guides de yso:tm en pompant avec un laser saphir:titane. Ce sont les premiers resultats laser obtenus pour des guides planaires de yso:tm. L'epitaxie en phase liquide est une technique qui permet de realiser des guides planaires. Toutefois pour certaines applications l'utilisation de guides de largeur limitee est plus interessante. Nous avons donc developpe des procedes de fabrication de guides de largeur limitee. Deux techniques differentes sont exposees dans ce memoire: l'une faisant appel a des procedes de micro-usinage, que nous avons baptise polisciage, et la seconde basee sur un principe de gravure chimique. Les resultats obtenus sont prometteurs et pourraient etre utilises pour de futures applications (guides d'ondes laser, amplificateurs)

Dans le cadre des recherches sur des dispositifs laser compacts pouvant etre pompes par diodes, ce memoire decrit le developpement d'une nouvelle technique d'elaboration de lasers guides d'onde, l'epitaxie en phase liquide. Cette technique a ete appliquee a la croissance de couches minces monocristallines de yag dope neodyme et ytterbium sur des substrats de yag non dope. Afin d'obtenir des guides de bonne qualite, nous avons defini les conditions de croissance des couches et montre l'interet de la croissance d'une surcouche de confinement. Deux co-dopages ont ete etudies en supplement a l'ion actif: gallium pour controler l'indice optique des couches, lutetium pour controler leur parametre cristallin. La determination du coefficient de segregation des divers dopants a requis le developpement d'un modele qui prend en compte l'evolution des bains au cours du temps. Nous avons mesure l'augmentation d'indice due a chaque dopant et propose un mecanisme expliquant cette augmentation. La caracterisation spectroscopique des couches a indique que les ions actifs ont les memes proprietes que le materiau massif de meme composition. La caracterisation laser a montre des pertes par propagation tres faibles (environ 0,1 db/cm), comparables a celles du materiau massif. Pour la transition laser a 1064 nm du neodyme, nous avons demontre l'effet laser pour une puissance absorbee au seuil de 700 w et mesure un rendement differentiel de 40% en pompage par diode, pour un seuil de 14 mw. Pour des transitions laser quasi-3 niveaux, une diminution significative du seuil par rapport a une configuration non guidee a ete obtenue: a 946 nm dans un guide dope neodyme, a 1029 nm dans un guide dope ytterbium en pompage par barrette de diode 1w. Un rendement differentiel de 80% a egalement ete mesure dans un guide dope ytterbium emettant a 1048 nm

In der vorliegenden Arbeit wird erstmals das QQDS-Magnetspektrometer für die höchstauflösende Ionenstrahlanalytik leichter Elemente am Helmholtz-Zentrum Dresden-Rossendorf umfassend vorgestellt. Zusätzlich werden sowohl alle auf die Analytik Einfluss nehmenden Parameter untersucht als auch Methoden und Modelle vorgestellt, wie deren Einfluss vermieden oder rechnerisch kompensiert werden kann. Die Schwerpunkte dieser Arbeit gliedern sich in fünf Bereiche. Der Erste ist der Aufbau und die Inbetriebnahme des QQDS-Magnetspektrometers, der zugehörige Streukammer mit allen Peripheriegeräten und des eigens für die höchstauflösende elastische Rückstoßanalyse entwickelten Detektors. Sowohl das umgebaute Spektrometer als auch der im Rahmen dieser Arbeit gebaute Detektor wurden speziell an experimentelle Bedingungen für die höchstauflösende Ionenstrahlanalytik leichter Elemente angepasst und erstmalig auf einen routinemäßigen Einsatz hin getestet. Der Detektor besteht aus zwei Komponenten. Zum einen befindet sich am hinteren Ende des Detektors eine Bragg-Ionisationskammer, die zur Teilchenidentifikation genutzt wird. Zum anderen dient ein Proportionalzähler, der eine Hochwiderstandsanode besitzt und direkt hinter dem Eintrittsfenster montiert ist, zur Teilchenpositionsbestimmung im Detektor. Die folgenden zwei Schwerpunkte beinhalten grundlegende Untersuchungen zur Ionen-Festkörper-Wechselwirkung. Durch die Verwendung eines Magnetspektrometers ist die Messung der Ladungszustandsverteilung der herausgestreuten Teilchen direkt nach einem binären Stoß sowohl möglich als auch für die Analyse notwendig. Aus diesem Grund werden zum einen die Ladungszustände gemessen und zum anderen mit existierenden Modellen verglichen. Außerdem wird ein eigens entwickeltes Modell vorgestellt und erstmals im Rahmen dieser Arbeit angewendet, welches den ladungszustandsabhängigen Energieverlust bei der Tiefenprofilierung berücksichtigt. Es wird gezeigt, dass ohne die Anwendung dieses Modells die Tiefenprofile nicht mit den quantitativen Messungen mittels konventioneller Ionenstrahlanalytikmethoden und mit der Dickenmessung mittels Transmissionselektronenmikroskopie übereinstimmen, und damit falsche Werte liefern würden. Der zweite für die Thematik wesentliche Aspekt der Ionen-Festkörper-Wechselwirkung, sind die Probenschäden und -modifikationen, die während einer Schwerionen-bestrahlung auftreten. Dabei wird gezeigt, dass bei den hier verwendeten Energien sowohl elektronisches Sputtern als auch elektronisch verursachtes Grenzflächendurchmischen eintreten. Das elektronische Sputtern kann durch geeignete Strahlparameter für die meisten Proben ausreichend minimiert werden. Dagegen ist der Einfluss der Grenzflächendurchmischung meist signifikant, so dass dieser analysiert und in der Auswertung berücksichtigt werden muss. Schlussfolgernd aus diesen Untersuchungen ergibt sich für die höchstauflösende Ionenstrahlanalytik leichter Elemente am Rossendorfer 5-MV Tandembeschleuniger, dass die geeignetsten Primärionen Chlor mit einer Energie von 20 MeV sind. In Einzelfällen, wie zum Beispiel der Analyse von Bor, muss die Energie jedoch auf 6,5 MeV reduziert werden, um das elektronische Sputtern bei der notwendigen Fluenz unterhalb der Nachweisgrenze zu halten. Der vierte Schwerpunkt ist die Untersuchung von sowohl qualitativen als auch quantitativen Einflüssen bestimmter Probeneigenschaften, wie beispielsweise Oberflächenrauheit, auf die Form des gemessenen Energiespektrums beziehungsweise auf das analysierte Tiefenprofil. Die Kenntnis der Rauheit einer Probe an der Oberfläche und an den Grenzflächen ist für die Analytik unabdingbar. Als Resultat der genannten Betrachtungen werden die Einflüsse von Probeneigenschaften und Ionen-Festkörper-Wechselwirkungen auf die Energie- beziehungsweise Tiefenauflösung des Gesamtsystems beschrieben, berechnet und mit der konventionellen Ionenstrahlanalytik verglichen. Die Möglichkeiten der höchstauflösenden Ionenstrahlanalytik werden zudem mit den von anderen Gruppen veröffentlichten Komplementärmethoden gegenübergestellt. Der fünfte und letzte Schwerpunkt ist die Analytik leichter Elemente in ultradünnen Schichten unter Berücksichtigung aller in dieser Arbeit vorgestellten Modelle, wie die Reduzierung des Einflusses von Strahlschäden oder die Quantifizierung der Elemente im dynamischen Ladungszustandsnichtgleichgewicht. Es wird die Tiefenprofilierung von Mehrschichtsystemen, bestehend aus SiO2-Si3N4Ox-SiO2 auf Silizium, von Ultra-Shallow-Junction Bor-Implantationsprofilen und von ultradünnen Oxidschichten, wie zum Beispiel High-k-Materialien, demonstriert
In this thesis the QQDS magnetic spectrometer that is used for high resolution ion beam analysis (IBA) of light elements at the Helmholtz-Zentrum Dresden-Rossendorf is presented for the first time. In addition all parameters are investigated that influence the analysis. Methods and models are presented with which the effects can be minimised or calculated. There are five focal points of this thesis. The first point is the construction and commissioning of the QQDS magnetic spectrometer, the corresponding scattering chamber with all the peripherals and the detector, which is specially developed for high resolution elastic recoil detection. Both the reconstructed spectrometer and the detector were adapted to the specific experimental conditions needed for high-resolution Ion beam analysis of light elements and tested for routine practice. The detector consists of two compo-nents. At the back end of the detector a Bragg ionization chamber is mounted, which is used for the particle identification. At the front end, directly behind the entrance window a proportional counter is mounted. This proportional counter includes a high-resistance anode. Thus, the position of the particles is determined in the detector. The following two points concern fundamental studies of ion-solid interaction. By using a magnetic spectrometer the charge state distribution of the particles scattered from the sample after a binary collision is both possible and necessary for the analysis. For this reason the charge states are measured and compared with existing models. In addition, a model is developed that takes into account the charge state dependent energy loss. It is shown that without the application of this model the depth profiles do not correspond with the quantitative measurements by conventional IBA methods and with the thickness obtained by transmission electron microscopy. The second fundamental ion-solid interaction is the damage and the modification of the sample that occurs during heavy ion irradiation. It is shown that the used energies occur both electronic sputtering and electronically induced interface mixing. Electronic sputtering is minimised by using optimised beam parameters. For most samples the effect is below the detection limit for a fluence sufficient for the analysis. However, the influence of interface mixing is so strong that it has to be included in the analysis of the layers of the depth profiles. It is concluded from these studies that at the Rossendorf 5 MV tandem accelerator chlorine ions with an energy of 20 MeV deliver the best results. In some cases, such as the analysis of boron, the energy must be reduced to 6.5 MeV in order to retain the electronic sputtering below the detection limit. The fourth focus is the study of the influence of specific sample properties, such as surface roughness, on the shape of a measured energy spectra and respectively on the analysed depth profile. It is shown that knowledge of the roughness of a sample at the surface and at the interfaces for the analysis is needed. In addition, the contribution parameters limiting the depth resolution are calculated and compared with the conventional ion beam analysis. Finally, a comparison is made between the high-resolution ion beam analysis and complementary methods published by other research groups. The fifth and last focus is the analysis of light elements in ultra thin layers. All models presented in this thesis to reduce the influence of beam damage are taken into account. The dynamic non-equilibrium charge state is also included for the quantification of elements. Depth profiling of multilayer systems is demonstrated for systems consisting of SiO2-Si3N4Ox-SiO2 on silicon, boron implantation profiles for ultra shallow junctions and ultra thin oxide layers, such as used as high-k materials

On a étudié la dynamique de réseau associée à la transition de phase de Peierls dans le composé quasi unidimensionnel à onde de densité de charge (odc) (tase4)2i, par diffusion de neutrons. Cette étude nous a permis de distinguer ce qui est caractéristique de l'état odc. En particulier, nous proposons d'interpréter la résonance observée en conductivité ac (45 ghz) comme des modes optiquement actives par l'état odc, plutôt que comme des modes caractéristiques de cet état. De même, la nature isotrope des fluctuations critiques ainsi que le caractère transverse acoustique des déplacements atomiques en phase modulée, amènent à placer cette transition de Peierls dans une catégorie à part. Un modèle phénoménologique qui prend en compte les deux aspects ci-dessus a été également proposé

Les développements de deux spéctromètres de saturation à ultra-haute résolution dans le domaine infrarouge, l'un dans la région spectrale 9-12 mu m et l'autre accordable de 2,3 a 3,2 mu m sont exposés en detail. La stabilisation en fréquence d'un laser à CO(2) conventionnel ou guide d'ondes au niveau de la dizaine de hertz ainsi que l'obtention d'une stabilité meilleure que 1 khz pour le laser à centres colores soulignent le role cle de ces oscillateurs dans la chaine de raccordement de fréquence de l'horloge à cesium vers le domaine visible. L'étude des interactions hyperfines est presentée dans le cas des molécules diatomiques héteronucleaires (hf) et des toupies spheriques du groupe ponctuel O(h) (sf(6)). Grace a l'enregistrement de structures hyperfines tres bien resolues, de nombreux effets ont etes mis en evidence et interpretes à l'aide du formalisme tensoriel (dans le groupe (l)o(3) x O(h)) en particulier : l'interaction de spin-vibration (bande upsilon (3) de sf(6)), les mélanges d'états de types de symétrie differents (sf(6)), les corrections ro-vibrationnelles à l'interaction de spin-rotation (hf et sf(6)), les structures superhyperfines (sf(6))

Abstract in English, Afrikaans and Zulu
This study explored how location and gender influence the performance of students in Physics in Akure South Local Government, Ondo State, Nigeria. The sample consisted of four schools randomly selected from the co-educational schools in the public schools. Data were collected through interviews, classroom observation, focus group interviews of the students and documents obtained from the school principals on students’ academic performance in the West African Senior Secondary Certificate Examination (WASSCE) from 2011-2015. The validity and the reliability of all these instruments were established. The data obtained through interviews were interpreted qualitatively. The documents obtained from the selected schools were also analyzed. The results of the study revealed that the urban students perform better in Physics than the rural students. The study also revealed that the gender of the students affects their performance in Physics with male students performing better than female students. Frantic efforts should be made to ensure conducive learning environment and equivalent learning opportunities to both male and female students.
Hierdie studie ondersoek hoe plek en geslag die prestasie van studente in Fisika in die Akure Suid-plaaslike regering, Ondo-staat, Nigerië, beïnvloed. Die steekproef het bestaan uit vier skole wat lukraak gekies is uit die mede-opvoedkundige skole in die openbare skole. Data is ingesamel deur onderhoude, klaskamerwaarnemings, fokusgroeponderhoude van die studente en dokumente wat van die skoolhoofde verkry is oor studente se akademiese prestasie in die Wes-Afrikaanse Senior Sekondêre Sertifikaat-eksamen (WASSCE) vanaf 2011-2015. Die geldigheid en betroubaarheid van al hierdie instrumente is vasgestel. Die data wat deur onderhoude verkry is, is kwalitatief geïnterpreteer. Die dokumente wat van die geselekteerde skole verkry is, is ook ontleed. Die resultate van die studie het getoon dat die stedelike studente beter in Fisika verrig as die landelike studente. Die studie het ook onthul dat die geslag van die studente hul prestasie in Fisika beïnvloed, met manlike studente wat beter presteer as vroulike studente. Vreemde pogings moet aangewend word om bevorderlike leeromgewing en gelykwaardige leergeleenthede vir beide manlike en vroulike studente te verseker.
Lolu cwaningo luhlolisise ukuthi indawo kanye nobulili bathonya kanjani ukusebenza kwabafundi e-Physics e-Akure South Local Government, e-Ondo State, eNigeria. Isampula lalinabashumayeli izikole ezine ngezikhathi ezikhethiwe kusukela izikole co-ezemfundo ezikoleni zikahulumeni. Idatha abangu eziqoqiwe ngokusebenzisa izingxoxo, ekilasini observation, izingxoxo somnqopho sokufundisa isiqhema lwabafundi futhi imibhalo etholakala othishanhloko esikoleni ekusebenzeni abafundi 'academic eNtshonalanga Afrika Senior Secondary Certificate Examination (WASSCE) kusuka 2011 kuya ku-2015. De geldigheid en de betrouwbaarheid van alle deze instrumenten efen-widegesteldeld. Imibuzo yezintambo ze-data verkregen yesikhala esiphezulu se-geïnterpreteerd. De dokumenter fra de udvalgte skoler blev også analysisret. Imiphumela cwaningo lwembula ukuthi abafundi ezisemadolobheni basebente kancono Physics ngaphandle abafundi basezindaweni zasemakhaya. Lolu cwaningo lwembula nokuthi ubulili abafundi Ithinta hun ukusebenza Physics ne abafundi besilisa kokwenza Ukuze ungcono abafundi besilisa nabesifazane. Imizamo eqondile kufanele kwenziwe ukuze kuqinisekiswe imvelo yokufunda kanye namathuba okufunda okulinganayo kokubili abafundi besilisa nabesifazane
Science and Technology Education
M. Ed. (Specialization in Natural Sciences)

Thesis (Ph. D.)--University of Wisconsin--Madison, 1993.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 192-202).

Yes
It has been proposed that mentalising involves retrodicting as well as predicting behaviour, by inferring previous mental states of a target. This study investigated whether retrodiction is impaired in individuals with Autism Spectrum Disorders (ASD). Participants watched videos of real people reacting to the researcher behaving in one of four possible ways. Their task was to decide which of these four “scenarios” each person responded to. Participants’ eye movements were recorded. Participants with ASD were poorer than comparison participants at identifying the scenario to which people in the videos were responding. There were no group differences in time spent looking at the eyes or mouth. The findings imply those with ASD are impaired in using mentalising skills for retrodiction.

Human cytomegalovirus (HCMV) is a ubiquitous virus of the herpes type that infects a high percentage of some populations. One of the most researched genes expressed by HCMV with close homology to human chemokine receptors is the US28 G protein-coupled receptor. Study design: This study was initiated to elucidate the intracellular signalling pathways of an inflammatory factor (IL-6) and an angiogenic factor (STAT3) triggered by the viral US28 oncogene and the presence of US28 in the HCMV viral particle. These pathways were observed by introducing the US28 gene into two human cell lines by infection with a HCMV strain that expresses the US28 gene (wild type), and two HCMV strains where the US28 gene was deleted (ÄUS28 and ÄUS28/UL33). Special attention was directed at the expression of IL-6 after promotion of the US28 gene and subsequent phosphorolation of STAT3. A new US28 antibody was validated and a method developed in an attempt to determine US28 on the viral particle. The following techniques were applied: Cell culture work, two mammalian cell lines were used, HFF’s and U373 MG. Virus stock titre determination to determine the multiplicity of infection. Protein quantitation to determine very small quantities of protein for Western blot analysis. ELISA for the quantitative determination of IL-6. Western blotting for phospho- STAT3 determination and validation of the US28 antibody. Immunocytochemistry was used for back titrations of virally infected cells. Immunofluorescence assay and use of confocal microscopic techniques was used for the location of the US28 gene in the virion and for tSTAT3 translocation to the nucleus. Conclusion: A clear increase in IL-6 secretion (495% ± 1%) was seen, and this was after only an hour in HCMV WT infected cells. From the increase in IL-6 secretion a subsequent increase in STAT3 phosphorylation was detected in the same samples. A clear link has been established between IL-6 and STAT3. A method to determine whether US28 was present in the HCMV viral particle was designed and preliminary results obtained. The results were inclusive.
Dissertation (MSc)--University of Pretoria, 2011.
Pharmacology
unrestricted

碩士
國立臺灣藝術大學
舞蹈學系
106
" Electronic­Musical­San­Tai­Zi" is Taiwan's emerging performance culture. It is a combination of pop music, dance, and the traditional folk art array " San-Tai-Zi." " Electronic­ Musical­San­Tai­Zi" originated from the " San-Tai-Zi". They used to use traditional gongs and drums as the background music. When the art squad went out in the 1980s, they inadvertently combined the electronic pop music with the " San-Tai-Zi " performances to combine traditional folklore. Modern pop music makes the form of performance very popular. Under the media's amnesty report, it forms a popular symbol of Taiwan's local culture. In 2009, Kaohsiung City of Taiwan won the right to host the "World Games" of the international large-scale comprehensive sports event. In the opening ceremony, " Electronic­ Musical­San­Tai­Zi" was selected as the opening program, which shows that the performance of the " Electronic­Musical­San­Tai­Zi" contains representatives. Taiwan's cultural characteristics. The purpose of this study is to analyze the culture of the Changmin and the stage performance art. In the research method, the application of Croce's aesthetic theory is used as the basis for the analysis of the opening performance of the "Kaohsiung City World Games – The Electronic­Musical­San­Tai­Zi", and the phenomenon of " Electronic­ Musical­San­Tai­Zi" will be on the international stage. Analysis of culture and history. The study found that as time changes, more and more traditional values and ideas are very different from before. Because of the impact of the trend of art culture in the new era, whether the inner spirit or the external image has also changed. This phenomenon is resulted from cultural creativity. From the tradtioion to the creation, the new performance of “Electronic­Musical­San­Tai­Zi” has naturally developed a new style language performing on the stage. It combines with pop music and dance to make young people be able to appreciate the young and lovely side of religion. During the process of integration, it will be a serious topic not only about how to get balance between the creation and the traditional culture value of the folk art parade but also about how to promote it on the world stage to become a specific Taiwan dance art culture.

The theme of the dissertation submitted is the novel Devil Guardian, whose author is a Mexican writer Xavier Velasco. This dissertation is the very first theoretical work in the Czech environment, devoted to the above-mentioned piece of literature published in 2004. In a sense, Devil Guardian represents a characteristic Mexican novel of the early 21st century, combining tradition and novelty in a surprising and original manner. A significant feature of the contemporary Mexican literature is a departure from the theme of Mexicanity, generally from a programmatic indulging in so-called national literature. Velasco's novel is an exemplary, however, not only piece of literature proving that the literary break-up with Mexico is neither an exclusive nor a dominant attribute of the contemporary Mexican fiction. In Devil Guardian Velasco focuses his mind on the theme of personal and national identity, which he treats in a considerably nontraditional manner, giving an ironical turn to speak to a hypermodern girl moving in the globalized world. The dissertation is divided into six parts. The first part "Originality Rooted in Tradition" refers to Devil Guardian ensuing the tradition of Mexican novel and innovating it. The second part "Xavier Velasco" briefly introduces the author's life and work. The issues...