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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Circuit de pilotage intégré pour transistor de puissance / Integrated driving circuit for power transistor

To, Duc Ngoc 02 April 2015 (has links)
Ces travaux de thèse s’inscrivent dans le cadre d’une collaboration entre les laboratoires G2ELAB et IMEP-LAHC en lien avec le projet BQR WiSiTUDe (Grenoble-INP). Le but de cette thèse concerne la conception, modélisation et caractérisation du gate driver intégré pour transistors de puissance à base d’un transformateur sans noyau pour le transfert isolé d'ordres de commutation. La thèse est composée de deux grandes parties : - Une partie de la conception, la modélisation et la caractérisation du transformateur intégré dans deux technologies CMOS 0.35 µm bulk et CMOS 0.18 µm SOI. - Une partie de la conception, la simulation et la mise en œuvre de deux circuits de commande intégrée dans ces deux technologies. Ainsi, l’aspect du système du convertisseur de puissance sera étudié en proposant une nouvelle conception couplée commande/puissance à faible charge. Les résultats de ce travail de thèse ont permis de valider les approches proposées. Deux modèles fiables (électrique 2D et électromagnétique 3D) du transformateur ont été établis et validés via une réalisation CMOS 0.35 µm standard. De plus, un driver CMOS bulk, intégrant l’ensemble du transformateur sans noyau avec plusieurs fonctions de pilotage de la commande rapprochée a été caractérisé et validé. Finalement, un gate driver générique a été conçu en technologie CMOS SOI, intégrant dans une seule puce les étages de commande éloignée, l’isolation galvanique et la commande rapprochée pour transistors de puissance. Ce gate driver présente nombre d’avantages en termes d’interconnexion, de la consommation de la surface de silicium, de la consommation énergétique du driver et de CEM. Les perspectives du travail de thèse sont multiples, à savoir d’une part l’assemblage 3D entre le gate driver et le composant de puissance et d’autre part les convertisseurs de multi-transistors. / This thesis work focuses on the design, modelling and the implementation of integrated gate drivers for power transistors based on CMOS coreless transformer. The main objectives of thesis are the design, modeling and characterization of coreless transformer in two technologies CMOS 0.35 µm bulk and CMOS 0.18 µm SOI, as well as the design and the characterization of two integrated gate drivers in these two technologies. The results of thesis allow us to validate our proposal models for coreless transformer: 2D electrical model and 3D electromagnetic model. Moreover, one CMOS bulk isolated gate driver which monolithically integrates the coreless transformer, the secondary side control circuit for power transistors has been fabricated and validated for both high side and low side configuration in a Buck converter. Finally, a CMOS SOI isolated gate driver is designed; integrates in one single chip the external control, the coreless transformer and the close gate driver circuit for power transistors. This one-chip solution presents a numerous advantages in term of interconnect parasitic, energy consumption, silicon surface consumption, and EMI with a high level of galvanic isolation. The perspectives of this SOI gate driver are multiple, on the one hand, are the 3D assemblies between gate driver/power transistors and on the other hand, are the multiple-switch converter.
122

Design methodology and technology assessment for high-desnity 3D technologies / Méthodologie de conception et de l'évaluation des technologies 3D haute densité

Sarhan, Hossam 23 November 2015 (has links)
L'impact des interconnections d'un circuit intégré sur les performances et la consommation est de plus en plus important à partir du nœud CMOS 28 nm et au-delà, ayant pour effet de minimiser de plus ne plus la loi de Moore. Cela a motivé l'intérêt des technologies d'empilement 3D pour réduire l'effet des interconnections sur les performances des circuits. Les technologies d'empilement 3D varient suivant différents procédés de fabrication d'où l'on mettra en avant la technologie Trough Silicon Via (TSV) – Collage Cuivre-Cuivre (Cu-Cu) et 3D Monolithique. TSV et Cu-Cu présentent des diamètres d'interconnexions 3D de l'ordre de 10 µm tandis que le diamètre d'une interconnexion 3D Monolithique est 0.1 µm, c'est-à-dire cent fois plus petit. Un tel diamètre d'interconnexion créée de nouveaux challenge en terme de conception de circuit intégré numérique. Dans ce contexte, notre objectif est de proposer des méthodologies de conception de circuits 3D innovantes afin d'utiliser au mieux la densité d'intégration possible et d'évaluer efficacement les gains en performance, surface et consommation potentiels de ces différentes technologies d'empilement par rapport à la conception de circuit 2D.Trois contributions principales constituent cette thèse : La densité d'intégration offerte par les technologies d'empilement étudiées laisse le possibilité de revoir la topologie des cellules de bases en les concevant directement en 3D. C'est ce qui a été fait dans l'approche Cellule sur Buffer (Cell-on-Buffer – CoB), en empilant la fonction logique de base d'une cellule sur l'étage d'amplification. Les simulations montrent des gains substantiels par rapport aux circuits 2D. On a imaginé par la suite désaligner les niveaux d'alimentation de chaque tranche afin de créer une technique de Multi-VDD adaptée à l'empilement 3D pour réduire encore plus la consommation des circuits 3D.Dans un deuxième temps, le partitionnement grain fin des cellules a été étudié. En effet au niveau VLSI, quand on conçoit un circuit de plusieurs milliers voir million de cellules standard en 3D, se pose la question de l'attribution de telle ou telle cellule sur la tranche haute ou basse du circuit 3D afin d'accroitre au mieux les performances et consommation du circuit 3D. Une méthodologie de partitionnement physique est introduite pour cela.Enfin un environnement d'évaluation des performances et consommation des technologies 3D est présenté avec pour objectif de rapidement tester les gains possibles de telle ou telle technologie 3D tout en donnant des directives quant à l'impact des certains paramètres technologiques 3D sur les performances et consommation. / Scaling limitations of advanced technology nodes are increasing and the BEOL parasitics are becoming more dominant. This has led to an increasing interest in 3D technologies to overcome such limitations and to continue the scaling predicted by Moore's Law. 3D technologies vary according to the fabrication process which creates a wide spectrum of technologies including Through-Silicon-VIA (TSV), Copper-to-Copper (CuCu) and Monolithic 3D (M3D). TSV and CuCu provide 3D contacts of pitch around 5-10um while M3D scales down 3D via pitch extremely to 0.11um. Such high-density capability of Monolithic 3D technology creates new design paradigms. In this context, our objective is to propose innovative design methodologies to well utilize M3D technology and introduce a technology assessment framework to evaluate different M3D technology parameters from design perspective.This thesis can be divided into three main contributions. As creating 3D standard cells become achievable thanks to M3D technology, a new 3D standard cell approach has been introduced which we call it ‘3D Cell-on-Buffer' (3DCoB). 3DCoB cells are created by splitting 2D cells into functioning gates and driving buffers stacked over each other. The simulation results show gain in timing performances compared to 2D. By applying an additionally Multi-VDD low-power approach, iso-performance power gain has been achieved. Afterwards cell-on-cell design approach has been explored where a partitioning methodology is needed to distribute cells between different tiers, i.e. determine which cell is placed on which tier. A physical-aware partitioning methodology has been introduced which improves power-performance-area results comparing to the state-of-the-art partitioning techniques. Finally a full high-density 3D technology assessment study is presented to explore the trade-offs between different 3D technologies, block complexities and partitioning methodologies.
123

Study Of Belts Acting As A Positioning System For Interconnected Gripping Tools In Tube Filling Machines / Studie av remmar verkande som positioneringssystem till sammanlänkade gripvertyg hos tubfyllingsmaskiner

Hohner, Robin, André, Ekengren January 2018 (has links)
The task performed in this assignment is to improve the reliability of Norden Machinery ABs product family. This is to be done by examining and replacing the belt used to stop the spreading of tubes from ingoing shipping crate to the infeed of the machine. The way that this was approached was by testing different candidates on a spectrum of their rigidity to find if a flexible or more rigid belt would perform better than the current context of the system. The testing was conducted for a period of 4 weeks and results were gathered by examining damages to the belts by the use of microscope. After the damage had been analyzed the conclusion was drawn that flexible alternatives seems to perform the task better than their rigid counterparts however more work is needed in the fields regarding the fastening and operation of the machine to use the best suited candidates derived from this test, the monolithic belt FMT-02TXCT-U1.
124

Novel mechanical alignment and component fabrication for wavelength-selective optical switches

Wilkinson, Peter John January 2018 (has links)
No description available.
125

Mikrotjänst-arkitektur och dess skalbarhet / The Scalability of Microservice Architecture

Larsson, Mattias January 2018 (has links)
Att designa mjukvaruapplikationer med en viss struktur kan ofta framhäva efterfrågade egenskaper. För att välja rätt arkitektur behövs ofta övervägningar, och ibland till och med kompromisser, göras om applikationens planerade karaktär. Det är ofta bra att i detta stadie ha en klar bild om vilka attribut en applikation önskas ha. Ett av de viktigare attributen på sikt är skalbarhet. Kunskapen om olika arkitekturers skalbarhet spelar en definitiv roll i designfasen, vilket avgör hur en applikation senare skalas. På senare år har mikrotjänst-arkitektur blivit ett populärt sätt att bygga mjukvara på där den höga skalbarheten sägs vara en bidragande faktor. Detta arbete har till syfte att undersöka skalbarheten hos mikrotjänst-arkitektur i förhållande till monolitisk arkitektur och visa hur detta kvalitetsattribut påverkas när en transformering från en monolit till en mikrotjänst-arkitektur görs. Arbetet har valt att utgå ifrån en existerande modul i en E-handelsplattform med öppen källkod. Modulen som transformerades till en mikrotjänst, skalades horisontellt för respektive arkitektur och applikations-version. Vid användandet av lämpliga verktyg, såsom Docker, visar resultatet att horisontell skalbarhet finns i högre grad hos mikrotjänst-arkitekturen och fortsätter därefter vara hög. Skalning av mikrotjänster kan göras med en högre precision av det som önskas förändras. Detta står i kontrast till den monolitiska strukturen, där skalning begränsas av prestandan av den miljö där mjukvaruapplikationen körs. Efter transformationen till en mikrotjänst-arkitektur ökade skalbarheten, då skalningsmetoden gjordes med mer finkornighet och isolering av den utvalda modulen. För att individuellt skala den monolitiska modulen horisontellt behövdes förändringen göras virtuellt med hjälp av bakgrundsprocesser. Denna lösning visar sig vara en indirekt skalning av hela den monolitiska strukturen. Utöver horisontell skalbarhet fokuserar utvärderingen av resultatet på kvalitativa attribut i form av simplicitet, autonomi och modularitet. / In designing software applications, a chosen structure can often accentuate desired properties. To choose the correct architecture, one must often do considerations and sometimes even compromises, about the intended characteristics of the application. In that stage it is often well motivated to have a clear picture about which attributes the application shall possess. Over time, one of the most important attributes is scalability. The knowledge about the scalability of different architectures could play a crucial part in the design phase, determining how an application is scaled in the future. In recent years Microservice Architecture has been a popular way of building software and its high scalability is said to be a contributing factor. This work has the purpose of examine the scalability of microservice architecture relative to the monolithic architecture and how this quality attribute is affected after a transformation is done from a monolith to a microservice system. This work is based on an existing module from an open source E-commerce platform. The module was first transformed into a working microservice, then both architectures was horizontally scaled. Using suitable tools such as Docker, the result of this work shows that horizontal scalability exists in a high degree within the microservice architecture and continues being high there after. Scaling of microservices can be done with higher precision of what are to be changed. This stands in relation to the monolithic approach where scaling is limited to the performance of the environment where the software application is running. The transformation to a microservice architecture resulted in an increase of scalability. The scaling method was more fined-grained and isolated to the selected module. In contrast, individual horizontal scaling of the monolithic module was required to be done virtually with background processes. This concluded in an indirect scaling of the whole structure of the monolith. Besides horizontal scalability, the evaluation is focused on the system quality attributes of simplicity, autonomy and modularity.
126

Isolation galvanique intégrée pour nouveaux transitors de puissance / Galvanic isolation integrated for new power transistors

Le, Thanh Long 19 November 2015 (has links)
Ces travaux de thèse proposent une approche de réalisation d'intégration d'isolation galvanique optique plus performante entre la partie de commande éloignée et la partie de puissance d'un convertisseur d'énergie. Ce mémoire de thèse est composé de trois chapitres. Après une étude bibliographique et un positionnement de l'approche dans le premier chapitre, la conception de la puce de commande, les différentes fonctions développées seront vus en détail, et les résultats pratiques et les performances des réalisations effectuées seront présentés, avec plusieurs études de photodétecteurs et circuits de traitement intégrés en technologie CMOS. Dans le dernier chapitre de la thèse, un autre aspect sera abordé, en intégrant une alimentation flottante isolée générée par voie optique. Les avantages résultant de cette approche seront également discutés. Les puces de commande sont fabriquées en technologie CMOS standard C35 AMS pour les premiers prototypes et transférées en technologie CMOS SOI Xfab 018 afin de tester nos fonctions à haute température. La mise en œuvre du circuit de commande par voie optique dans un convertisseur de puissance sera réalisée afin de valider le fonctionnement de notre « gate driver ». / This works proposes an approach of optical galvanic isolation between the control parts on one side and the power transistors and their associated drivers on the other side. This thesis consists of three chapters. After a literature review and the proposition of our approach in the first chapter, the design of the control chip and the different developed functions will be seen in detail in the second chapter. The practical results and performance achievements will be presented with several integrated photodetectors and signal processing circuit in CMOS technology. In the last chapter of the thesis, an integrated optically floating power supply will be investigated. The benefits of this approach will be discussed. These fabricated chips are manufactured in standard CMOS AMS C35 technology for first prototypes and transferred in SOI Xfab 018 CMOS technology to test these functions at high temperature. The implementation of the optically control circuit in a power converter will be presented to validate the operation of our "gate driver".
127

Retenção de coroas de zircônia: estudo de diferentes condições de tratamento interno de coroas em zirconia e do núcleo em resina composta / Retention of zirconia crowns: evaluation of different conditions of y-tzp intaglio surface and the composite core

Wandscher, Vinicius Felipe 12 January 2017 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The present thesis was structured in two scientific articles that investigated the adhesion of zirconium oxide ceramic crowns. The first article aimed to evaluate different methods for silica deposition at the inner surface of Y-TZP crowns by means of a retention test. A hundred simplified full-crown preparations obtained from fiber-reinforced polymer were scanned and 100 zirconium oxide crowns with occlusal retention were machined. The preparation/crown assemblies were randomly divided in 5 groups according to the inner surface treatment: TBS – tribochemical silica coating with silica-coated alumina particles (30 μm); GHF1 – application of a thin glaze layer + hydrofluoric acid for 1 min; GHF5 – glaze application + hydrofluoric acid for 5 min; GHF15 – glaze application + hydrofluoric acid for 15 min; and Nano – silica nanofilm deposition (5 nm) via magnetron sputtering. All groups received silane coupling agent application. The preparations surfaces were etched with 10% hydrofluoric acid for 30 s and silanized. Crowns were cemented with resin cement, thermocycled (12.000 cycles; 5 / 55 °C), stored for 60 days and submitted to retention test (0.5 mm/min until failure). Retention data (MPa) were statistically analyzed by one way– ANOVA and Tukey test, as well as Weibull analysis. Failures were classified as 50C (above 50% of cement in the crown) and 50S (above 50% of cement on the substrate). TBS (5.6 ± 1.7 MPa) and Nano (5.5 ± 1 MPa) groups showed higher retention values than the other groups (p<0.0001), as well as higher characteristic strength (6.18 e 5.91, respectively). There was no difference for Weibull modulus, except for GHF1 group, which showed statistically inferior value. TBS and GHF15 presented, respectively, 60% and 70% of the failures classified as 50C, while the other groups had 50S as most part of the failures. Air-abrasion with silica-coated alumina particles and silica nanofilm deposition on the inner surface of Y-TZP crowns generated higher retention values. The second article evaluated the retention of zirconia crowns cemented to aged composite cores and prepared with burs of different grit sizes. Sixty simplified full-crown preparations were fabricated with composite resin and scanned. Sixty zirconium oxide crowns with occlusal retention were machined. The composite resin cores were stored for 120 days in humid environment at 37 °C and randomly divided in 3 groups (n=20) according to the finishing of the composite resin core: CTRL (control) – no treatment; EFB – extra-fine diamond bur (25 μm); and CB – coarse diamond bur (107 μm). Superficial grinding was performed with an adapted surveyor to standardize speed and pressure. The inner surfaces of the crowns were air-abraded with silica-coated alumina particles (30 μm) and a silane coupling agent was applied. Crowns were cemented with a self-adhesive resin cement (RelyX U200). Then, the assemblies core/crown were thermocycled (12.000 cycles; 5/55°C), stored for 120 days and submitted to retention test (0.5 mm/min until failure). Tesile date (MPa were analyzed by one way- ANOVA and Tukey test (p≤0,05), as well as Weibull analysis. Failures were classified as 50C (above 50% of cement adhered in the crown), 50S (above 50% of cement adhered on the resin substrate) and COE (cohesive failure of the core). No statistical difference was observed for the retention values (p=0.975), but the control group (CTRL) showed higher Weibull modulus. The predominant failure mode was 50S. The occurrence of cohesive failures was higher on the control group. Retention of the zirconium oxide crowns was not affected by the core roughness. It was concluded that air-abrasion followed by silane application and silica nanofilms deposition improve the retention of zircônia crowns, as well as finishing of resin cores with diamond burs does not influence the retention of zirconia crowns. / A presente tese foi estruturada em dois artigos científicos que investigaram a adesão de coroas de cerâmicas à base de óxido de zircônio. O primeiro artigo objetivou avaliar diferentes métodos de deposição de sílica na superfície interna de coroas de Y-TZP por meio de teste de retenção. Para isso, 100 preparos simplificados para coroa total produzidos a partir de polímeros reforçados por fibras com foram escaneados e 100 coroas em óxido de zircônio com retenções oclusais foram usinadas. Os conjuntos preparo/coroa foram divididos de forma randômica em 5 grupos (n=20) de acordo com o tratamento da superfície interna: TBS- jateamento com partícula de alumina revestida por sílica (30 μm); GHF1- aplicação de fina camada de glaze + ácido fluorídrico por 1 min; GHF5- aplicação de glaze + ácido fluorídrico por 5 min; GHF15- aplicação de glaze + ácido fluorídrico por 15 min; e Nano- deposição de nanofilme de sílica (5 nm) via desbastamento iônico. Todos os grupos receberam aplicação de um agente de união silano. As superfícies dos preparos foram condicionadas com ácido fluorídrico 10% por 30 s e silanizadas. As coroas foram cimentadas com um cimento resinoso, termocicladas (12.000 ciclos; 5 / 55 °C), armazenadas por 60 dias e submetidas ao teste de retenção (0.5 mm/min até a falha). Os dados de retenção (MPa) foram analisados estatisticamente utilizando-se ANOVA- um fator e teste de Tukey (p≤0,05), além da análise de Weibull. As falhas foram classificadas em 50C (acima de 50% do cimento aderido na coroa) e 50S (acima de 50% de cimento no substrato). Os grupos TBS (5.6 ± 1.7 MPa) e Nano (5.5 ± 1 MPa) apresentaram maiores valores de retenção do que os demais grupos (p<0.0001), assim como maiores valores de resistência característica (6.18 e 5.91, respectivamente). Não houve diferença no módulo de Weibull exceto para o grupo GHF1, que apresentou valor estatisticamente inferior. Os grupos TBS e GHF15 apresentaram, respectivamente, 60 e 70% de suas falhas classificadas como 50C, enquanto os outros grupos apresentaram a maior parte das falhas 50S. O jateamento com partículas de alumina revestidas por sílica e a deposição de nanofilme de sílica na superfície interna de coroas de Y-TZP promoveram maiores valores de retenção. O segundo artigo avaliou a retenção de coroas de zircônia cimentadas em núcleos protéticos envelhecidos construídos em resina composta e preparados com brocas diamantadas de diferentes granulações. Para isso, 60 preparos simplificados para coroa total foram confeccionados em resina composta e escaneados. Sessenta coroas à base de óxido de zircônio com retenções oclusais foram usinadas. Os preparos em resina composta foram armazenados por 120 dias em ambiente úmido a 37 °C e randomicamente divididos em 3 grupos (n=20) de acordo com o tipo de finalização do núcleo em resina: CTRL (controle) – sem tratamento; EFB – broca diamantada extrafina (25 μm); e CB – broca grossa (107 μm). O desgaste superficial foi realizado por meio de um paralelômetro adaptado com o objetivo de padronizar a velocidade e a pressão de desgaste. As superfícies internas das coroas foram jateadas com partículas de alumina revestidas por sílica (30 μm) e então um agente de união silano foi aplicado. As coroas foram cimentadas com um cimento resinoso autoadesivo (RelyX U200). Então, os conjuntos núcleo/coroa foram termociclados (12.000 ciclos; 5/55°C), armazenados por 120 dias e submetidos ao teste de retenção (0.5 mm/min até a falha). Os dados de tração (MPa) foram analisados por meio de ANOVA- um fator e teste de Tukey (p≤0,05), assim como análise de Weibull. As falhas foram classificadas como 50C (mais que 50% de cimento aderido na coroa), 50S (mais que 50% de cimento aderido ao substrato de resina) e COE (fratura coesiva do núcleo). Nenhuma diferença estatística foi observada nos valores de retenção (p=0.975), porém o grupo controle (CTRL) apresentou o maior módulo de Weibull. O tipo de falha predominante foi 50S. A ocorrência de falhas coesivas foi maior no grupo controle. A retenção das coroas à base de óxido de zircônio não foi afetada pela rugosidade do núcleo. Concluiu-se que jateamento seguido de silano e deposição de nanofilmes de sílica aumentam a retenção de coroas de zircônia, assim como o acabamento de núcleos de resina com pontas diamantadas não influencia a retenção de coroas de zircônia.
128

Construção de dispositivos de pressurização e de aquecimento para a preparação e funcionalização de fases estacionárias monolíticas via processo sol-gel

Ribeiro, Sandro Pereira 06 August 2015 (has links)
Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-01-09T12:20:47Z No. of bitstreams: 1 sandropereiraribeiro.pdf: 1843700 bytes, checksum: 116a82b85c5101d893b55d6830abb954 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-01-23T11:18:44Z (GMT) No. of bitstreams: 1 sandropereiraribeiro.pdf: 1843700 bytes, checksum: 116a82b85c5101d893b55d6830abb954 (MD5) / Made available in DSpace on 2018-01-23T11:18:44Z (GMT). No. of bitstreams: 1 sandropereiraribeiro.pdf: 1843700 bytes, checksum: 116a82b85c5101d893b55d6830abb954 (MD5) Previous issue date: 2015-08-06 / No presente trabalho foi proposto a compreensão das variáveis inerentes à criação de infraestrutura adequada para preparação de fase estacionária monolítica (FEM) utilizando colunas capilares de 100 mm de diâmetro interno para aplicação em electroromatografia capilar (CEC). A fim de alcançar a elucidação do processo de funcionalização do monolíto, as FEM foram produzidas por química de sol-gel. Neste caso, a mistura otimizada de reagentes origina o sol que muda de um estado líquido para o estado de gelificação no interior do tubo capilar, resultando em uma superfície polimérica. Dentro deste contexto, foi desenvolvido um dispositivo manual para alta pressão (DMAP) para a inserção do sol nas colunas capilares. O DMAP à vácuo montado foi desenvolvido no Grupo de Química Analítica e Quimiometria (GQAQ) a fim de tornar possível a produção de colunas monolíticas de maneira otimizada e reprodutível. Este dispositivo tornou possível o preenchimento interno da coluna capilar de forma homogênea através do trabalho forçado em movimento, como capilaridade, na qual o sol é introduzido diretamente do frasco ao capilar, evitando o contato do sol com acessórios e dispositivos, como conexões, seringas e agulhas. Como objetivo secundário, estudos para preparação das FEM modificadas por nanopartículas de ouro- AuNps foram realizadas. As AuNps foram sintetizadas através da reação de redução com o citrato de sódio e a passivação com o uso da quitosana. As nanopartículas foram ancoradas na superficie do monolito para melhorar a funcionalização das FEM e possibilitar testes com diversos analitos. Essa reação foi caracterizada por Microscopia Eletrônica de Transmissão- MET, Microscopia Eletrônica de Varredura- MEV, Ultravioleta Visível- UV-Vis. Nesse mesmo tempo foi montado um segundo dispositivo denominado mini-forno para aquecimento radial homogénea do tubo capilar, a fim de atingir a funcionalização adequada. Finalmente, todas as colunas preparadas e funcionalizadas com sucesso foram submetidas a testes de separação de mistura padrão de HPAs. / In the present work the understanding of the inherent variables to establishment of adequate infrastructure to monolithic stationary phase (MSP) preparation using capillary columns at 100 μm of internal diameter to application in capillary electrocromatography (CEC) was proposed. Thus, in order to achieve the elucidation of the monolithic functionalization process, the MSP were produced by sol-gel chemistry. In this case, the optimized mixture of reagents originates the sol which changes from liquid state to the jellification state inside the capillary tube, resulting in a polymeric surface. Within this context, was developed a manual device to high pressure (MDHP) for sol insertion into the capillaries columns. The vacuum MDHP assembled was developed in the Grupo de Química Analítica e Quimiometria (GQAQ) in order to make possible the optimized and reproducible monolithic columns production. This device made possible the internal fill of the capillary column in homogenous way through of forced moving such as capillarity, in which the sol is introduced direct from the vial to the capillary, avoiding the contact of the sol with accessories and devices such as connections, syringes and needles. This procedure avoids air passage into the capillary tube and the contamination of devices and accessories, providing the operation in presence of any type of solution. Thus, the MDHP became possible a significant advance in the understanding of the MSP preparation mediated by sol-gel chemistry and photopolimerization. As a secondary objective, studies to preparation of MSP modified by gold nanoparticles were carried out. In this same time was assembled a second device called mini oven to homogeneous radial heating of the capillary in order to achieves the adequate functionalization. Finally, all columns prepared and functionalized with success were submitted to tests of HPAs standard mixture separation.
129

Desenvolvimento e avaliação de métodos de extração e separação cromatográfica em colunas monolíticas e superficialmente porosas para determinação de herbicidas triazínicos em solos e águas / Development and evaluation of extraction and chromatographic methods in monolithic and core-shell columns for determination of triazine herbicides in soils and waters

Ricardo De Prá Urio 10 December 2015 (has links)
O uso de pesticidas levou ao aumento da produtividade e qualidade dos produtos agrícolas, porém o seu uso acarreta na intoxicação dos seres vivos pela ingestão gradativa de seus resíduos que contaminam o solo, a água e os alimentos. Dessa forma, há a necessidade do monitoramento constante de suas concentrações nos compartimentos ambientais. Para isto, busca-se o desenvolvimento de métodos de extração e enriquecimento de forma rápida, com baixo custo, gerando um baixo volume de resíduos, contribuindo com a química verde. Dentre estes métodos destacam-se a extração por banho de ultrassom e a extração por ponto nuvem. Após o procedimento de extração, o extrato obtido pode ser analisado por técnicas de Cromatografia a Líquido de Alta Eficiência (HPLC) e a Cromatografia por Injeção Sequencial (SIC), empregando fases estacionárias modernas, tais como as monolíticas e as partículas superficialmente porosas. O emprego de SIC com coluna monolítica (C18, 50 x 4,6 mm) e empacotada com partículas superficialmente porosas (C18, 30 x 4,6 mm, tamanho de partícula 2,7 µm) foi estudado para separação de simazina (SIM) e atrazina (ATR), e seus metabólitos, desetilatrazina (DEA), desisopropilatrazina (DIA) e hidroxiatrazina (HAT). A separação foi obtida por eluição passo-a-passo, com fases móveis compostas de acetonitrila (ACN) e tampão Acetato de Amônio/Ácido acético (NH4Ac/HAc) 2,5 mM pH 4,2. A separação na coluna monolítica foi realizada com duas fases móveis: MP1= 15:85 (v v-1) ACN:NH4Ac/HAc e MP2= 35:65 (v v-1) ACN:NH4Ac/HAc a uma vazão de 35 µL s-1. A separação na coluna com partículas superficialmente porosas foi efetivada com as fases móveis MP1= 13:87 (v v-1) ACN: NH4Ac/HAc e MP2= 35:65 (v v-1) ACN:NH4Ac/HAc à vazão de 8 µL s-1. A extração por banho de ultrassom em solo fortificado com os herbicidas (100 e 1000 µg kg-1) resultou em recuperações entre 42 e 160%. A separação de DEA, DIA, HAT, SIM e ATR empregando HPLC foi obtida por um gradiente linear de 13 a 35% para a coluna monolítica e de 10 a 35% ACN na coluna com partículas superficialmente porosas, sendo a fase aquosa constituída por tampão NH4Ac/HAc 2,5 mM pH 4,2. Em ambas as colunas a vazão foi de 1,5 mL min-1 e o tempo de análise 15 min. A extração por banho de ultrassom das amostras de solo com presença de ATR, fortificadas com concentrações de 250 a 1000 µg kg-1, proporcionou recuperações entre 40 e 86%. A presença de ATR foi confirmada por espectrometria de massas. Foram realizados estudos de fortificação com ATR e SIM em amostras de água empregando a extração por ponto nuvem com o surfactante Triton-X114. A separação empregando HPLC foi obtida por um gradiente linear de 13 a 90% de ACN para a coluna monolítica e de 10 a 90% de ACN para a coluna empacotada, sempre em tampão NH4Ac/HAc 2,5 mM pH 4,2. Em ambas as colunas a vazão foi de 1,5 mL min-1 e o tempo de análise 16 min. Fortificações entre 1 e 50 µg L-1 resultaram em recuperações entre 65 e 132%. / The use of pesticides has led to increased productivity and quality of agricultural products, but its use brings the intoxication of living beings by the gradual intake of their residues that contaminate soil, water and food. Thus, there is the need for constant monitoring of their concentrations in environmental compartments. For this, there is a quest for development of fast extraction and enrichment methods, at low cost, generating a low volume of waste, contributing to green chemistry. These methods include the extraction assisted by ultrasound bath and the cloud point extraction. After the extraction, the extract obtained can be analyzed by techniques such as High Performance Liquid Chromatography (HPLC) and Sequential Injection Chromatography (SIC) employing modern stationary phases, such as monolithic and superficially porous particles. The use of SIC with either monolithic column (C18, 50 x 4.6 mm) or column packed with superficially porous particles (C18, 30 x 4.6 mm, 2.7 µM particle size) was studied for separating simazine (SIM) and atrazine (ATR), and metabolites, deethylatrazine (DEA), deisopropylatrazine (DIA) and hydroxyatrazine (HAT). Separation was obtained by stepwise elution, with a mobile phase consisting of acetonitrile (ACN) and 2.5 mM ammonium acetate / acetic acid (NH4Ac / HAc) pH 4.2 buffer. The separation was performed with two mobile phases: MP1 = 15:85 (v v -1) ACN: NH4Ac / HAc and MP2 = 35:65 (v v-1) ACN: NH4Ac / HAc at a flow rate of 35 µL s-1. The separation in the column with superficially porous particles was carried out with the mobile phases MP1 = 13:87 (v v-1) ACN: NH4Ac / HAc and MP2 = 35:65 (v v-1) ACN: NH4Ac / HAc at 8 µL s-1. The ultrasound bath extraction from a soil fortified with herbicides (100 and 1000 µg kg-1) resulted in recoveries between 42 and 160 %. Separation of DEA, DIA, HAT SIM and ATR was obtained by HPLC employing a linear gradient from 13 to 35% for the monolithic column and from 10 to 35% ACN in the column packed with superficially porous particles, with the aqueous phases consisting of 2.5 mM NH4Ac / HAc buffer pH 4.2. In both columns the flow rate was 1.5 mL min-1 and the analysis time was15 min. Ultrasonic extraction from a soil sample containing ATR, fortified with concentrations from 250 to 1000 µg kg-1, provided recoveries between 40 and 86%. The presence of ATR was confirmed by mass spectrometry. Fortification studies with ATR and SIM were carried out in water samples employing cloud point extraction using Triton-X114 surfactant. The separation was accomplished by HPLC using a linear gradient from 13 to 90 % of ACN for the monolithic column and from 10 to 90 % ACN for the packed column, always in 2.5 mM NH4Ac / HAc pH 4.2 buffer. In both columns the flow rate was 1.5 mL min -1 and the analysis time 16 min. Fortifications between 1 and 50 µg L-1 resulted in recoveries between 65 and 132%.
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Desenvolvimento de suporte catalítico monolítico para fins aeroespaciais empregando a manufatura aditiva / Monolithic catalytic support development for aerospace applications employing additive manufacture

Isaias de Oliveira 20 July 2018 (has links)
No presente trabalho foi desenvolvido um suporte catalítico monolítico para fins aeroespaciais empregando a manufatura aditiva. Para tanto, foi proposta uma geometria que proporcione um escoamento turbulento, permitindo um maior contato entre o reagente e a superfície do catalisador, proporcionando menor perda de carga ao sistema. Esta nova estrutura foi obtida via manufatura aditiva, através da técnica de Sinterização Seletiva a Laser (SLS) indireta. Para utilizar a técnica SLS e material cerâmico, foi necessário desenvolver um revestimento sobre as partículas de alumina para promover a aderência entre as mesmas durante o processo de manufatura aditiva. Em seguida foram definidos, experimentalmente, os parâmetros de aplicação da técnica SLS para o compósito alumina/poliamida. Por fim, foi fabricado, via SLS, o suporte catalítico na forma monolítica. Após a confecção do suporte monolítico, foi desenvolvido um revestimento composto de pseudo-boemita e nitrato de alumínio e aplicado na superfície do monólito, a fim de expandir a área superficial específica do material. Este aumento da área específica favorece a dispersão da fase ativa, composta de óxidos de cobalto e manganês, na superfície do suporte. A caracterização do catalisador monolítico foi realizada a partir das técnicas de Adsorção de Nitrogênio, Análise Termogravimétrica, Microscopia Eletrônica de Varredura e Espectrometria de Emissão Ótica com Fonte de Plasma (ICP-OES). O desempenho do catalisador monolítico na decomposição do H2O2 concentrado foi analisado via teste de gota, monitorado por câmera de alta velocidade. Os bons resultados obtidos nesta reação apontam esta técnica de obtenção de suporte catalítico monolítico através da manufatura aditiva como uma metodologia promissora a ser empregada em sistemas catalíticos com elevada difusão de massa e calor, mas principalmente em sistemas propulsivos a monopropelente. / This work was developed by the additive manufacture monolithic catalytic support to apply aerospace applications. A geometry was proposed to implement a turbulent flow allowing a better contact with catalytic surface and reagent with a low pressure drop in the system. This new structure was obtained by additive manufacture through indirect Selective Laser Sintering (SLS) technique. Firstly, in order to use the SLS for the ceramic material was developed a coating on the alumina particles to promote a melting between them during addictive manufacturing process. Secondly, the printer parameters SLS was configurated into the alumina/polyamide particle. Finally, the monolithic catalytic support was built via SLS. After the monolithic support building, the pseudo-boehmite and aluminum nitrate coating was developed and applied on the monolithic surface to increase the specific superficial area of the material. This increasing of the specific surface area helps the spread of the active phase to made up of cobalt and manganese oxide in the support surface. The characterization of the monolithic catalyst was carried out using the nitrogen adsorption technique, thermogravimetric analysis, scanning electron microscopy and inductive coupled plasma with optical emission spectrometry. The monolithic catalytic performance in the H2O2 concentrated decomposition was analyzed via drop test monitored by the high-speed camera. The good results of this reaction and such a technique of monolithic catalytic support obtainment through the additive manufacture show that a promising methodology can be used in the catalytic system with high diffusion of mass and heat but mainly, in monopropellant propulsive system.

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