Devant l'intérêt croissant pour l'environnement et la conservation de la biodiversité, comprendre les principaux mécanismes des cycles biogéochimiques ayant lieu dans les écosystèmes coralliens et lagonaires est une priorité. Un modèle 3D couplé physique-biochéochimique a été mis en place sur le lagon de Nouvelle-Calédonie (NC) : un 'hot spot' de biodiversité sous l'influence de divers forçages d'origines naturelles et anthropiques.Les interactions terre-lagon ont été abordées à travers l'étude d'un événement extrême La Nina (2008) qui cause de fortes précipitations, amenant d'importants apports dans le lagon.Les résultats du modèle fournissent une vue synoptique de la réponse biogéochimique-physique du lagon, mettant en évidence que la totalité du lagon fût impacté par les apports des rivières et un hydrodynamisme plus actif, où les concentrations en chlorophylle-a ont été doublées.L'interaction complexe océan-lagon a été abordée à travers la modélisation des processus d'upwelling du Sud Ouest (SO) de la NC. Quatre étés australs ont été simulés, mettant en évidence l'importance des processus d'upwelling qui représentent un important forçage de la production primaire au SO de la NC. Une analyse lagrangienne du transport a montré que les eaux issues de l'upwelling peuvent atteindre le lagon SO sous certaines conditions, un phénomène pouvant avoir des conséquences sur le recrutement larvaire et l'enrichissement du lagon. Le modèle 3D couplé est un outil robuste pour l'étude de cet environnement très variable et complexe. Il peut représenter une aide à la décision des managers ainsi qu'un support d'analyse et de planification d'échantillonnage aux scientifiques. / In view of increasing environmental awareness and biodiversity conservation, understanding the main forcing mechanism driving biogeochemical cycles in coral reefs and lagoon coastal areas is a priority. We used a 3D coupled 'on-line' physical-biogeochemical model on the New Caledonia lagoon : a hot spot of biodiversity under several forcing from climate to human origin.Interactions between land and lagoon were investigated through the study of an extreme event La Niña (2008) that caused heavy rainfalls and large organic and inorganic inputs in the lagoon.Model results provided a synoptic view of the lagoon biogeochemical-physical response, highlighting that the whole lagoon was impacted by river inputs and stronger hydrodynamics were the chlorophyll-a concentration was almost double.The complex interaction between the ocean and the lagoon was investigated through the modeling of the South Western (SW) wind-driven upwelling. Four austral summers (2005-2008) were simulated and results were found to be in good agreement with measured data reported in previous publications, highlighting that upwelling processes represent strong drivers of the primary production in the SW of NC. A Lagrangian transport analysis showed that oceanic upwelled waters were able to reach the South West lagoon under certain conditions, representing an important issue for larvae recruitment and lagoon enrichment. The 3D coupled on-line biogeochemical-physical model was a robust tool to study such complex and highly variable environment. It could represent a support for decision makers to manage coastal areas as well as for scientists to plan sampling strategy or to analyse cruise data.

[pt] Neste trabalho, métodos baseados em diferentes abordagens em eletroforese capilar (CE) foram propostos. No caso da determinação de compostos organoestanhos ou OTs (difenilestanho e monofenilestanho) em fluidos biológicos, foi usada abordagem de eletroforese capilar por zona (CZE) hifenada com a espectrometria de massas (do tipo quadrupolo) com fonte de plasma indutivamente acoplado (CE-ICP-MS). As condições de análise foram estudadas no modo univariado visando otimizar a composição da solução eletrolítica (tampão acetato 5,0 mmol L(-1), pH 2,8) e obter os parâmetros instrumentais (45 graus Celsius, mais 30 kV e 30 s de tempo de introdução hidrodinâmica de amostra). A solução de complementação foi uma solução aquosa 5,0 mmol L(-1) de NH4NO3 contendo 10 por cento metanol em volume e 1,0 Mg L(-1) de Cspositivo, com pH ajustado para 2,8 com tampão acetato. A vazão dessa solução foi mantida em 40 ML min(-1). Os OTs foram diluídos em solução de metanol:tampão acetato de sódio 50:50 por cento v/v ou apenas em tampão acetato de sódio pH 2,8. As condições de detecção do ICP-MS foram ajustadas em 1200 W, 15 L min(-1) de vazão de argônio para formação do plasma, 1 L min(-1) de vazão de argônio auxiliar. A vazão de argônio do nebulizador foi ajustada diariamente. Os isótopos de estanho 120Sn e 118Sn foram monitorados, assim como o 133Cspositivo para controlar a eficiência e estabilidade do processo de nebulização. A resposta linear do método ficou entre 0,050 a 2,0 mg L(-1) de Sn (0,42 a 17 Mmol L-(1)). Os limites de detecção (LOD) e de quantificação (LOQ) em termos de Sn foram de 15 Mg L(-1) (0,13 Mmol L(-1)) e 50 Mg L-1 (0,42 Mmol L(-1)), calculados utilizando a menor concentração dos picos dos analitos que podem ser diferenciados do sinal de fundo. A repetibilidade para o tempo de migração e área dos picos ficou próximo a 5 por cento. O método foi aplicado na análise de urina, sangue total e plasma fortificados com os OTs. Recuperações entre 75 e 95 por cento foram obtidas. No caso da determinação de sete pesticidas da classe das estrobilurinas (azoxistrobina, 9 dimoxistrobina, fluoxastrobina, picoxistrobina, piraclostrobina, trifloxistrobina e kresoxim-metil) em sopas infantis, foi usada a cromatografia eletrocinética capilar micelar (MEKC) com detecção fotométrica (no UV) com capilar de caminho óptico estendido. Um estudo multivariado, usando um planejamento 33 Box Behnken, indicou que a melhor separação para os pesticidas foi com solução aquosa de eletrólito composto por tampão tetraborato de sódio (5,1 mmol L(-1), pH 9,0) contendo 51 mmol L(-1) de dodecil sulfato de sódio (SDS) e 24 por cento acetonitrila (ACN) em volume. As condições instrumentais foram 25 C e mais 30 kV de diferença de potencial aplicada, 45 s de tempo de introdução hidrodinâmica de amostra e detecção em 210 nm. Para aumentar o poder de detecção, foi usada a concentração dos analitos no capilar. Para tal, as soluções de padrões e amostras foram dissolvidas em solução tampão tetraborato de sódio 45 mmol L(-1): acetonitrila 80:20 por cento v/v. As curvas analíticas apresentaram comportamento linear e os valores de LOD ficaram entre 7,0 Mg L(-1) ou 18 nmol L(-1) (piraclostrobina) a 15 Mg L-1 ou 33 nmol L(-1) (fluoxastrobina). Os valores de LOQ ficaram entre 21 Mg L(-1) ou 54 nmol L(-1) (piraclostrobina) a 45 Mg L(-1) ou 98 nmol L(-1) (fluoxastrobina). A repetibilidade ficou entre 1,7 a 7,9 por cento para a área de pico e entre 0,25 a 0,71 por cento para o tempo de migração. A precisão intermediária, avaliada com análises realizadas em diferentes dias, apresentou valores entre 1,3 a 5,3 por cento para a área de pico e entre 0,06 a 0,90 por cento para o tempo de migração. O método foi aplicado na análise de sopas prontas infantis fortificadas com as estrobilurinas. Os pesticidas foram extraídos aplicando o método QuEChERS com ajuste de pH com tampão acetato e limpeza com extração em fase sólida dispersiva. Os resultados das análises obtidos com um método cromatográfico adaptado da literatura foram estatisticamente iguais aos alcançados com o método proposto. A CZE foi o modo de separação escolhido para mostrar o potencial da determinação indireta de aminoglicosídeos com medição de fluorescência de pontos quânticos (excitação com laser de diodo em 410 nm) amplificada na presença dos analitos. A fotoluminescência dos pontos quânticos (nanopartículas de CdTe modificados com ácido tioglicólico monodispersas em solução) foi mais intensa em solução tampão (pH 8,0) contendo entre 5 e 10 mmol L(-1) de tetraborato de sódio. A interação no capilar entre aminoglicosídeos (neomicina e canamicina) e os pontos quânticos provocou aumento de fotoluminescência dependente do pH do meio (indício de interação de natureza 10 eletrostática). Alguns parâmetros de mérito foram avaliados com uma faixa linear curta (0,1 a 1,0 mol L(-1) para canamicina e 0,03 a 0,5 mol L(-1) para neomicina). Os valores mínimos detectados de 0,1 Mmol L(-1) ou 58 Mg L(-1) (canamicina) e 0,03 Mmol L(-1) ou 27 Mg L(-1) (neomicina) mostram que essa é uma abordagem interessante para a determinação sensível de aminoglicosídeos. / [en] In this work, analytical methods based on different approaches using capillary electrophoresis (CE) have been proposed. For the determination of organotins or OTs (diphenyltin and monophenyltin) in biological fluids, the separation using capillary zone electrophoresis (CZE) was applied using tandem with inductively coupled plasma mass spectrometry (CE-ICP-MS). The conditions for the analysis were optimized in an unvaried way aiming to find the conditions for the electrolyte solution (acetate buffer, 5.0 mmol L (-1), pH 2.8) and the employed instrumental parameters (45C, 30 kV and 30 s of the time for hydrodynamic introduction of the sample). A complementary solution was composed by NH4NO3 5.0 mmol L(-1), 10 por cento v/v of methanol and 1.0 g L(-1) of Cspositive in acetate buffer with pH adjusted to 2.8. The flow of this solution was set to 40 ML min(-1). The OTs were diluted either in a methanol: acetate buffer 50:50 por cento v/v solution or only in sodium acetate buffer pH 2.8. The conditions for detection by ICP-MS were set to 1200 W, 15 L min(-1) for the Ar plasma flow and 1,0 L min(-1) for the auxiliary Ar. The nebulizer Ar flow was adjusted daily. The monitored tin isotopes were 120Sn 118Sn. The isotope 133Cs was also monitored in order to control the efficiency and stability of the nebulization. The method presented a linear response between 0.05 and 2.0 mg L(-1) (0.42 a 17 Mmol L(-1)) for Sn. The value for the limits of detection (LOD) and for the limits of quantification (LOQ) for Sn were 15 Mg L(-1) (0.13 Mmol L-1) e 50 Mg L(-1) (0.42 Mmol L(-1)), calculated based on the lowest concentration of the analyte peaks that can be differentiated from the background signal. The repeatability for migration time and peak area was approximately 5 per cent. The method was applied in the analysis of organotin fortified blood and urine samples with recoveries between 75 and 95 per cent. In the case of the determination of seven strobilurin class pesticides (azoxystrobin, dimoxystrobin, fluoxastrobin, picoxystrobin, pyraclostrobin, trifloxystrobin and kresoxim-methyl) in baby food (vegetable and fruit soups), 12 the micellar electrokinetic capillary chromatography (MEKC) was used using photometric detection (UV) in a capillary with extended optical path. A multivariate study, with 33 Box Behnken design, indicated the best composition for the electrolytic solution to separate the seven pesticides: a sodium tetraborate buffer (5.1 mmol L(-1), pH 9.0) solution containing 51 mmol L(-1) sodium dodecyl sulfate and acetonitrile (24 por cento in volume). The instrumental conditions were 25C, 30 kV of applied voltage, 45 s for hydrodynamic introduction of the sample and detection at 210 nm. To increase the detection power, the concentration of the analytes into the capillary was used by using the Normal Stacking Mode. For this purpose, the solutions of standards and samples were prepared in 45 mmol L(-1) sodium tetraborate buffer solution: acetonitrile 80:20 por cento v/v. The analytical curves presented a linear behavior and the LOD values were between 7.0 Mg L (-1) or 18 nmol L(-1) (pyraclostrobin) to 15 Mg L(-1) or 33 nmol L(-1) (fluoxastrobin). The LOQ values were between 21 Mg L(-1) or 54 nmol L(-1) (pyraclostrobin) a 45 Mg L(-1) ou 98 nmol L(-1) (fluoxastrobin). The repeatability was between 1.7 to 7.9 por cento for the peak area and between 0.25 to 0.71 por cento for the migration time. The intermediate precision, evaluated by the analysis performed in different days were between 1.3 to 5.3 por cento for the peak area and between 0.06 and 0.90 per cent for the migration time. The method was applied in the analysis of baby food spiked with strobilurin. Pesticides were extracted using the QuEChERS method with pH adjustment with acetate buffer and clean-up using the dispersive solid phase extraction. The analysis results were statistically identical to those obtained with a chromatographic method adapted from the literature. The CZE separation mode was chosen to evaluate the potential of the indirect determination of aminoglycosides through the amplified photoluminescence from quantum dots (excitation laser diode 410 nm) in the presence of the analytes. The photoluminescence from quantum dots (monodispersed CdTe nanoparticles modified with thioglycolic acid) was more intense in buffer solution (pH 8.0) containing between 5 and 10 mmol L(-1) sodium tetraborate. The interaction between aminoglycosides (kanamycin and neomycin) and quantum dots inside the capillary caused the increasing of fluorescence in a pH-dependent way (indicating the electrostatic nature for the interaction). A few figures of merit were evaluated with a short linear range (0.1) to 1.0 Mmol L(-1) for kanamycin and 0.03 to 0.5 Mmol L(-1) for neomycin). The 13 minimum values detected were 0.1 nmol L(-1) or 58 Mg L(-1) (kanamycin) and 0.03 nmol L(-1) or 27 Mg L(-1) (neomycin) showing that the proposed approach can be used to detect aminoglycosides in a relatively sensitive way.

Cette thèse aborde la problématique de la modélisation multiphysique en génie électrique, avec une application à l’étude des vibrations d’origine électromagnétique des cages de développantes. Cette étude comporte quatre parties : la construction de la densité de courant, le calcul des forces locales, le transfert de solutions entre maillages et la résolution des problèmes couplés. Un premier enjeu est de correctement représenter les courants, cette opération est effectuée en deux étapes : la construction de la densité de courant et l’annulation de la divergence. Si des structures complexes sont utilisées, l’imposition du courant ne peut pas toujours être réalisée à l’aide de méthodes analytiques. Une méthode basée sur une résolution électrocinétique ainsi qu’une méthode purement géométrique sont testées. Cette dernière donne des résultats plus proches de la densité de courant réelle. Parmi les nombreuses méthodes de calcul de forces, les méthodes des travaux virtuels et des forces de Laplace, considérées par la littérature comme les plus adaptées au calcul des forces locales, ont été étudiées. Nos travaux ont montré que bien que les forces de Laplace sont particulièrement précises, elles ne sont pas valables si la perméabilité n’est plus homogène. Ainsi, la méthode des travaux virtuels, applicable de manière universelle, est préférée. Afin de modéliser des problèmes multi-physiques complexes à l’aide de plusieurs codes de calculs dédiés, des méthodes de transferts entre maillages non conformes ont été développées. Les procédures d’interpolations, les méthodes localement conservatives et les projections orthogonales sont comparées. Les méthodes d’interpolations sont réputées rapides mais très diffusives tandis que les méthodes de projections sont considérées comme les plus précises. La méthode localement conservative peut être vue comme produisant des résultats comparables aux méthodes de projections, mais évite l’assemblage et la résolution de systèmes linéaires. La modélisation des problèmes multi-physiques est abordée à l’aide des méthodes de transferts de solutions. Pour une classe de problème donnée, l’assemblage d’un schéma de couplage n’est pas unique. Des tests sur des cas analytiques sont réalisés afin de déterminer, pour plusieurs types de couplages, les stratégies les plus appropriées.Ces travaux ont permis une application à la modélisation magnéto-mécanique des cages de développantes est présentée. / The modeling of multi-phycics problems in electrical engineering is presented, with an application to the numerical computation of vibrations within the end windings of large turbo-generators. This study is divided into four parts: the impositions of current density, the computation of local forces, the transfer of data between disconnected meshes, and the computation of multi-physics problems using weak coupling, Firstly, the representation of current density within numerical models is presented. The process is decomposed into two stages: the construction of the initial current density, and the determination of a divergence-free field. The representation of complex geometries makes the use of analytical methods impossible. A method based on an electrokinetical problem is used and a fully geometrical method are tested. The geometrical method produces results closer to the real current density than the electrokinetical problem. Methods to compute forces are numerous, and this study focuses on the virtual work principle and the Laplace force considering the recommendations of the literature. Laplace force is highly accurate but is applicable only if the permeability is uniform. The virtual work principle is finally preferred as it appears as the most general way to compute local forces. Mesh-to-mesh data transfer methods are developed to compute multi-physics models using multiples meshes adapted to the subproblems and multiple computational software. The interpolation method, a locally conservative projection, and an orthogonal projection are compared. Interpolation method is said to be fast but highly diffusive, and the orthogonal projections are highly accurate. The locally conservative method produces results similar to the orthogonal projection but avoid the assembly of linear systems. The numerical computation of multi-physical problems using multiple meshes and projections is then presented. However for a given class of problems, there is not an unique coupling scheme possible. Analytical tests are used to determine, for different class of problems, the most accurate scheme. Finally, numerical computations applied to the structure of end-windings is presented.

Ce mémoire de thèse présente le développement de la méthode «statistical modal energy distribution analysis (SmEdA)» pour des systèmes vibro-acoustiques couplés. Cette méthode de calcul est basée sur le bilan énergétique dans des sous-systèmes fermés couplés, comme une structure ou une cavité. L’interaction entre de tels systèmes est décrite par des couplages entre les modes. La version initiale de SmEdA prend en compte seulement les modes qui ont une fréquence propre dans le bande d’excitation. Le travail présenté ici étudie l’effet des modes non résonants sur la réponse et identifie les cas dans lesquels un tel effet devient important. L’introduction des modes non résonants permet d’utiliser la méthode SmEdA dans des cas d’applications plus larges. En outre, une nouvelle méthode de post-traitement a été développée pour calculer des distributions d'énergie dans les sous-systèmes. Finalement, une nouvelle méthode d'approximation pour la prise en compte des modes de systèmes de grandes dimensions ou mal définis a été formulée. Toutes ces méthodes ont été comparées avec d’autres méthodes de calcul via des exemples académiques et industriels. Ainsi, la nouvelle version de SmEdA incluant le post-traitement pour obtenir des distributions d'énergie a été validé et les avantages et possibilités d'applications sont montrés. / This dissertation presents the further development of the statistical modal energy distribution analysis (SmEdA) for vibro-acoustic coupled problems. This prediction method is based on the energy balance in bounded coupled subsystems, like a structure or a cavity. The interaction between such subsystems is described by mode-to-mode coupling. The original SmEdA formulation takes into account only the modes having the eigenfrequencies within the excitation band. The present work investigates the effect of non resonant modes to the response and identifies cases in which such an effect becomes important. The inclusion of non resonant modes has thus resulted in a new SmEdA formulation which can be used in extended applications. Furthermore, a new post-processing method has been developed to predict energy distribution within subsystems. Finally a novel approximation method for handling modes of huge or ill-defined systems has been formulated. All these methods have been compared to other prediction methods via academic and industrial examples. In this way, the extended SmEdA approach including the post-processing for energy distribution has been validated and its advantages and application possibilities have been demonstrated.

Depuis deux décennies, la révolution technologique est avant tout numérique entrainant une forte croissance de la quantité de données à stocker. Le rythme de cette croissance est trop importante pour les solutions de stockage matérielles, provoquant une augmentation du coût de l'octet. Il est donc nécessaire d'apporter une amélioration des solutions de stockage ce qui passera par une augmentation de la taille des réseaux et par la diminution des copies de sauvegarde dans les centres de stockage de données. L'objet de cette thèse est d'étudier l'utilisation des codes en graphe dans les réseaux de stockage de donnée. Nous proposons un nouvel algorithme combinant construction de codes en graphe et allocation des noeuds de ce code sur le réseau. Cet algorithme permet d'atteindre les hautes performances des codes MDS en termes de rapport entre le nombre de disques de parité et le nombre de défaillances simultanées pouvant être corrigées sans pertes (noté R). Il bénéficie également des propriétés de faible complexité des codes en graphe pour l'encodage et la reconstruction des données. De plus, nous présentons une étude des codes LDPC Spatiallement-Couplés permettant d'anticiper le comportement de leur décodage pour les applications de stockage de données.Il est généralement nécessaire de faire des compromis entre différents paramètres lors du choix du code correcteur d'effacement. Afin que ce choix se fasse avec un maximum de connaissances, nous avons réalisé deux études théoriques comparatives pour compléter l'état de l'art. La première étude s'intéresse à la complexité de la mise à jour des données dans un réseau dynamique établi et déterminons si les codes linéaires utilisés ont une complexité de mise à jour optimale. Dans notre seconde étude, nous nous sommes intéressés à l'impact sur la charge du réseau de la modification des paramètres du code correcteur utilisé. Cette opération peut être réalisée lors d'un changement du statut du fichier (passage d'un caractère hot à cold par exemple) ou lors de la modification de la taille du réseau. L'ensemble de ces études, associé au nouvel algorithme de construction et d'allocation des codes en graphe, pourrait mener à la construction de réseaux de stockage dynamiques, flexibles avec des algorithmes d'encodage et de décodage peu complexes. / For two decades, the numerical revolution has been amplified. The spread of digital solutions associated with the improvement of the quality of these products tends to create a growth of the amount of data stored. The cost per Byte reveals that the evolution of hardware storage solutions cannot follow this expansion. Therefore, data storage solutions need deep improvement. This is feasible by increasing the storage network size and by reducing data duplication in the data center. In this thesis, we introduce a new algorithm that combines sparse graph code construction and node allocation. This algorithm may achieve the highest performance of MDS codes in terms of the ratio R between the number of parity disks and the number of failures that can be simultaneously reconstructed. In addition, encoding and decoding with sparse graph codes helps lower the complexity. By this algorithm, we allow to generalize coding in the data center, in order to reduce the amount of copies of original data. We also study Spatially-Coupled LDPC (SC-LDPC) codes which are known to have optimal asymptotic performance over the binary erasure channel, to anticipate the behavior of these codes decoding for distributed storage applications. It is usually necessary to compromise between different parameters for a distributed storage system. To complete the state of the art, we include two theoretical studies. The first study deals with the computation complexity of data update and we determine whether linear code used for data storage are update efficient or not. In the second study, we examine the impact on the network load when the code parameters are changed. This can be done when the file status changes (from a hot status to a cold status for example) or when the size of the network is modified by adding disks. All these studies, combined with the new algorithm for sparse graph codes, could lead to the construction of new flexible and dynamical networks with low encoding and decoding complexities.

Este trabalho visa o projeto, modelagem e fabricação de estruturas multicamadas baseadas em polímeros para aplicações como sensores ópticos integrados. A grande motivação para este trabalho está no fato de que estas estruturas, diferente da geometria Mach-Zehnder, dispensam o uso de litografia pois são completamente planares. Isto permite uma diminuição no custo de fabricação dos dispositivos além de permitir que estruturas mais curtas sejam utilizadas. Em se tratando de óptica integrada, as dimensões reduzidas da estrutura impõem severas penalidades no processo de lançamento de potência óptica na mesma. Por isso, será considerada neste estudo a utilização de prismas para o acoplamento de entrada do acoplador. Esta técnica, além de reduzir drasticamente os problemas de alinhamento decorrentes de acoplamento convencional do tipo \"End Fire\", permite uma transferência de potência óptica superior a 80% entre a fibra e o guia retangular. As variações na transferência de potência entre os guias de ondas da estrutura multicamada serão medidas através de um fotodetetor MSM integrado ao sensor. Este detetor, além de sua extrema facilidade de fabricação e baixos custos, torna o conjunto sensor mais robusto. Em se tratando de uma proposta de plataforma para sensores, serão também investigadas possíveis aplicações para esta estrutura, como por exemplo: refratômetro integrado, sensor de glicose, sensor de adulteração de combustível, etc. A análise das estruturas será efetuada por meio de técnicas de modelagem analíticas (Técnica da Matriz de Transferência - TMT e Teoria de Modos Acoplados - TMA), e numéricas (Método da Propagação de Feixe de Ângulo Largo formulado em Diferenças Finitas - WA-FD-BPM). Esta última permite que a estrutura do fotodetetor seja levada em consideração simultaneamente nas simulações. / This work concerns with design, modeling and fabrication of polymer based planar multilayer structures for integrated optic sensor applications. The motivation for this work is that planar multilayer structures, differently from the Mach-Zehnder geometry, do not require a lithographic process. As a consequence, significantly cheaper and shorter structures can be realized. The reduced dimensions of the structure, by its turn, pose a severe penalty in terms of optical power coupling. Therefore, this investigation will focus primarily on input (and output) prism coupling configuration. This technique, besides reducing the alignment requirements observed for conventional end-fire coupling, allows optical power coupling efficiency as high as 80% from fiber to rectangular waveguide. Any optical power transfer between the waveguides of the multilayer structure will be detected by an MSM photodetector integrated with the sensor. This low cost photodetector, besides improving the structure robustness, is quite ease to fabricate. Since the idea of this work is to develop a platform for integrated optic sensors, it will also be investigated possible applications for this structure, such as: integrated optic refractometer, glucose sensor and fuel adulteration sensor. The analysis of such structures will be carried out by means of analythical (Transfer Matrix Technique-TMT and Coupled Mode Theory-CMT) and numerical (Wide-Angle Finite Difference Beam Propagation Method-WA-FD-BPM) modeling techniques. The WA-FD-BPM technique allows one to simulate the multilayer waveguide and the MSM photodetector simultaneously.

Neste projeto foram abordados procedimentos analíticos para extração, separação e identificação de espécies de arsênio encontradas normalmente em quantidades de traços e ultra-traços em amostras biológicas e ambientais. Entre as amostras alvo deste estudo, teve-se alimentos de origem marinha como por exemplo camarão. Foi avaliada a estabilidade das espécies de arsênio nas soluções geradas pelos processos de extração. Para separação das espécies inorgânicas (arsenito e arsenato), metiladas (ácidos mono e dimetil arsênio) e orgânicas (arsenobetaina) empregaram-se as técnicas eletroforese capilar (CE) e cromatografia líquida (LC). Os sistemas de separação para a determinação das espécies de arsênio foram acoplados com os espectrômetros massas (ICP-MS), e de fluorescência atômica (AFS). Os sistemas acoplados apresentaram resolução e sensibilidade na determinação das espécies de arsênio nas amostras estudadas neste trabalho. A extração com água de espécies de As utilizando-se banho de ultra-som apresentou eficiência acima de 78%. A estabilidade das espécies nas soluções padrão e nos extratos das amostras foi mantida por um período de até uma semana quando armazenadas em geladeira (+4°C). Visando uma política de química limpa, foi desenvolvida uma metodologia para evitar desperdiço preparando micro-volumes de amostras e soluções padrão, para especiação de arsênio por eletroforese capilar. Para tal se empregou um injetor seqüencial, também foi desenvolvido um dispositivo de injeção hidrodinâmica para eletroforese capilar. Além disto, as soluções residuais geradas durante a pesquisa analítica foram tratadas para a recuperação de arsênio e boro. A extração no ponto nuvem foi empregada para recuperar As entanto que a precipitação por mineralização hidrotérmica foi aplicada para a recuperação de B . A aplicação deste procedimento resultou na extração de 80% de arsênio e 75% de boro. Isto, permitiu converter grandes volumes de resíduos líquidos perigosos em um pequeno volume de resíduos sólidos / Analytical procedures for extraction, separation and identification of arsenic species at ultra-trace levels in biological and environmental samples were investigated. Stability studies of arsenic species in sample extracts and standard solutions were carried out. Separation of arsenite, arsenate, monomethylarsonic and dimethylarsinic acids and also arsenobetaine were carried out by capillary electrophoresis or liquid chromatography. Determination of the separated arsenic species was accomplished by coupling the separation techniques to inductively coupled plasma mass spectrometry (ICP-MS) or atomic fluorescence spectrometry (AFS). Satisfactory resolution and sensibility were achieved by the coupled systems described. Extraction efficiency better than78% were achieved with water in an ultrasonic bath at the laboratory temperature (23-27°C). Whereas, stability of species in solutions stored in refrigerator at +4°C was efficient for aperiod up to one week. Micro-volumes of standards and sample solutions mixed in a sequential injector were prepared for arsenic speciation by capillary electrophoresis, aiming green chemistry. A time controlled micro-volume injector device for hydrodinamic injections was also developed. Finally, waste solutions from arsenic speciation analysis in a system with hydride generation were treated for arsenic and boron removal. Cloud point extraction for recovery of arsenic and hydrothermal mineralization of boron by calcium hydroxide were employed. Satisfactory removal of 80% of arsenic and 75% of boron from waste solution was achieved. These procedures allowed to reduce volumes of hazardous waste solutions

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Pregnenolona (PREG) e 17-alfa-hidroxipregnenolona (17OHPREG) são dois esteroides produzidos pela glândula adrenal e precursores de vários hormônios esteroidais. A dosagem desses compostos tem aplicações clínicas, como o diagnóstico de doenças relacionadas aos corticoesteroides e mineralocorticóides e especialmente na avaliação da atividade da enzima 3-β-hidroxidesidrogenase que é decisiva no diagnóstico de um dos tipos de hiperplasia da glândula adrenal que causa defeitos severos na síntese de esteroides. Métodos cromatográficos associados à espectrometria de massas superaram a especificidade reduzida dos imunoensaios e tem sido crescentemente utilizados na quantificação de esteroides. Os últimos anos tem sido marcados pela hegemonia da cromatografia líquida acoplada à espectrometria de massas em tandem (LC-MS/MS) em grande parte devido à velocidade e possibilidade da análise direta de vários analitos. Porém, no caso específico dos esteroides de tipo 3-hidroxi-5-eno, que apresentam baixa afinidade protônica e, portanto, baixa eficiência de ionização, são necessárias muitas etapas para a conversão em derivados mais detectáveis. Embora desfavorecida em relação ao LC-MS/MS nos últimos anos, a cromatografia gasosa acoplada à espectrometria de massas (CG-MS) apresenta várias características favoráveis para a análise de esteroides como a eficiência cromatográfica ainda insuperável. Adicionalmente, a incorporação da espectrometria de massas em tandem ao CG (CG-MS/MS) torna a técnica tão seletiva quanto LC-MS/MS. No presente trabalho, foi desenvolvido um novo método que permite a extração e derivatização simultâneas da PREG e 17OHPREG de amostras de soro tornando o método de preparo da amostra tão simples quanto os descritos para LC-MS/MS. O método de detecção desenvolvido baseado em ionização química no modo negativo obteve a sensibilidade necessária para o diagnóstico da deficiência da enzima 3-beta-hidroxidesidrogenase utilizando apenas 250 &#181:L de amostra. / Pregnenolone (PREG) and 17α-hydroxypregnenolone (17OHPREG) are two steroid precursors produced by the adrenal gland. The quantification of these compounds is essential for the evaluation of 3-β-hidroxidesidrogenase enzyme activity, which promotes the conversion of PREG in 17OHPREG. The 3-&#946:-hidroxidesidrogenase deficiency is a rare but severe type of adrenal hyperplasia that causes serious defects in steroid synthesis. Chromatographic methods coupled to mass spectrometry overcame immunoassays limitations such as reduced specificity, and have been widely used for steroids quantification. Recent years have been marked by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) hegemony due to the speed and possibility to analyze directly several analytes. However, in the case of type 3-hydroxy-5-ene steroids, which have low affinity for protons and, therefore, low ionization efficiency, many steps are required for conversion to detectable products. Notwithstanding, gas chromatography coupled to mass spectrometry (GC-MS) has some favorable features for steroid analysis such as unbeatable chromatographic efficiency. In addition, the incorporation of tandem mass spectrometry (GC-MS/MS) makes it as selective as LC-MS/MS. In this study, a new method for simultaneous extraction and derivatization of PREG and 17OHPREG from serum was developed. This procedure makes sample preparation for GC-MS/MS as simples as those described for LC-MS/MS. The detection method based on negative mode chemical ionization achieved the sensitivity required for the diagnosis of 3-β-hidroxidesidrogenase defficiency using only 250 µL of sample.