• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 45
  • 21
  • 11
  • 10
  • 4
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 116
  • 116
  • 21
  • 21
  • 20
  • 17
  • 15
  • 13
  • 13
  • 12
  • 11
  • 10
  • 10
  • 9
  • 8
  • 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.
81

Síntese da zeólita Beta usando planejamento experimental e emprego na isomerização do n-hexano / Synthesis of Beta zeolite using experimental design and application in isomerization of n-hexane

Oliveira, Kátia Dionísio de 14 September 2012 (has links)
Submitted by Kátia Oliveira (katiadionisio@yahoo.com.br) on 2017-10-11T14:01:46Z No. of bitstreams: 1 Tese (Oliveira, KD).pdf: 7712617 bytes, checksum: c39a9ee83f33d05d99d354f6a524019f (MD5) / Rejected by Ronildo Prado (producaointelectual.bco@ufscar.br), reason: Faltou inserir a carta de aprovação on 2017-10-11T18:32:06Z (GMT) / Submitted by Kátia Oliveira (katiadionisio@yahoo.com.br) on 2017-10-11T18:41:31Z No. of bitstreams: 2 Tese (Oliveira, KD).pdf: 7712617 bytes, checksum: c39a9ee83f33d05d99d354f6a524019f (MD5) Carta comprovante.pdf: 149973 bytes, checksum: 67927f9413f2368fa8bac2ceb19f248d (MD5) / Approved for entry into archive by Ronildo Prado (bco.producao.intelectual@gmail.com) on 2018-01-18T18:52:09Z (GMT) No. of bitstreams: 2 Tese (Oliveira, KD).pdf: 7712617 bytes, checksum: c39a9ee83f33d05d99d354f6a524019f (MD5) Carta comprovante.pdf: 149973 bytes, checksum: 67927f9413f2368fa8bac2ceb19f248d (MD5) / Approved for entry into archive by Ronildo Prado (bco.producao.intelectual@gmail.com) on 2018-01-18T18:52:44Z (GMT) No. of bitstreams: 2 Tese (Oliveira, KD).pdf: 7712617 bytes, checksum: c39a9ee83f33d05d99d354f6a524019f (MD5) Carta comprovante.pdf: 149973 bytes, checksum: 67927f9413f2368fa8bac2ceb19f248d (MD5) / Made available in DSpace on 2018-01-18T19:04:18Z (GMT). No. of bitstreams: 2 Tese (Oliveira, KD).pdf: 7712617 bytes, checksum: c39a9ee83f33d05d99d354f6a524019f (MD5) Carta comprovante.pdf: 149973 bytes, checksum: 67927f9413f2368fa8bac2ceb19f248d (MD5) Previous issue date: 2012-09-14 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / This work aimed to apply the Design Of Experiment (DOE) methodology as an auxiliary tool to evaluate the conditions of synthesis of the aluminum-rich zeolite Beta. Bimetallic catalysts with 50% platinum and 50% nickel (50Pt50Ni) supported on zeolites with various Si/Al ratios were synthesized, characterized and evaluated in the isomerization of n-hexane. In the first part of this work, five variables related to the synthesis of zeolite Beta were evaluated by a series of statistical designs, in which the response variables were the relative intensities of the X-ray patterns and the yield of phase BEA. The results of the t-test showed that the ratio TEAOH/SiO2 is not significant for the formation and crystallization of zeolite Beta. However, the interaction of this variable with the Si/Al ratio was statistically significant. In order to obtain the aluminum-rich zeolite Beta, the samples were synthesized with partial substitution of cations TEA+ by cations Na+. The XRD patterns of these samples showed that BEA phase was formed using a Si/Al ratio of 5,0 and 7.5. These low values of Si/Al ratio were confirmed by inductively coupled plasma atomic emission spectroscopy (ICP-AES) and energy-dispersive X-ray spectroscopy (EDS). Information about the main properties of the 50Pt50Ni catalysts such as activity, conversion and selectivity to di-branched isomers in the isomerization of n-hexane were obtained by performing catalytic tests. Concerning these properties, the catalysts supported on the synthesized zeolite Beta (Si/Al = 7.5) showed better catalytic performance compared with catalysts supported on commercial zeolite Beta (Si/Al = 9.0). Additionally to these tests, a study on the kinetics of reduction of ions Pt2+ and Ni2+ on these catalysts was conducted using X-ray absorption spectroscopy (XAS). The combination of XAS analysis and catalytic tests showed the importance of maintaining a bimetallic platinum and nickel system in order to obtain satisfactory performance of catalysts applied to the isomerization of n-hexane. The XAS results suggested that Pt2+ ions are reduced in lower temperatures compared to Ni2+ ions, and that the addition of platinum to the nickel-based samples promoted the reduction of Ni2+ ions. The catalytic results suggested that equilibrium between acid and metal sites exists during the isomerization of n-hexane. The understanding of this equilibrium is of major importance to increase the yield and selectivity to di-branched isomers. / Este trabalho teve como objetivo a utilização da metodologia de planejamento experimental como uma ferramenta auxiliar para avaliar as condições de síntese da zeólita Beta rica em alumínio. Catalisadores bimetálicos com 50% de platina e 50% de níquel (50Pt50Ni) com teor de metal total de 130 μmol gcat-1 e suportados em zeólitas com diferentes razões Si/Al foram sintetizados, caracterizados e avaliados na reação de isomerização do n-hexano. Na primeira parte do trabalho, cinco variáveis da síntese da zeólita Beta foram avaliadas por uma série de planejamentos estatísticos, nos quais as variáveis respostas analisadas foram a intensidade de difração relativa dos difratogramas de raios X e o rendimento à fase BEA obtida. Os resultados obtidos a partir do teste t demonstraram que a razão TEAOH/SiO2 não foi significativa para o processo de cristalização e formação da zeólita Beta. No entanto, a interação desta variável com a razão Si/Al apresentou significância estatística. Para a obtenção da zeólita Beta rica em alumínio, amostras foram sintetizadas com a substituição parcial dos cátions TEA+ por cátions Na+. Nos difratogramas de raios X destas amostras foi possível identificar a fase BEA para valores de Si/Al de 5,0 e 7,5. Estes baixos valores de Si/Al nas amostras sintetizadas foram confirmados pelas técnicas de espectroscopia por emissão de plasma indutivo (ICP) e análise dispersiva de raios X (EDS). Informações a respeito das principais propriedades dos catalisadores bimetálicos 50Pt50Ni tais como atividade, conversão e seletividade a isômeros birramificados na isomerização do n-hexano, foram obtidas através da realização de testes catalíticos. Com relação a estas propriedades, os catalisadores suportados na zeólita Beta sintetizada (Si/Al = 7,5) apresentaram melhores desempenhos catalíticos quando comparados aos catalisadores suportados na zeólita Beta comercial (Si/Al = 9,0). Paralelamente, um estudo sobre a cinética de redução dos cátions metálicos Pt2+ e Ni2+ destes catalisadores foi realizado através da técnica de espectroscopia de absorção de raios X (XAS). As análises de XAS aliadas aos resultados dos testes catalíticos sugeriram a importância de se manter um sistema bimetálico de platina e níquel de maneira a se obter um desempenho satisfatório dos catalisadores aplicados à isomerização do n-hexano. Os resultados de XAS sugeriram que temperaturas menores são necessárias para reduzir os cátions metálicos Pt2+ quando comparados aos cátions Ni2+, e que a adição de cátions Pt2+ contribui consideravelmente para a redução dos cátions Ni2+, diminuindo a temperatura de redução deste último. Os resultados apresentados neste trabalho sugeriram a existência de um equilíbrio entre a proporção de sítios ácidos e metálicos durante a isomerização do n-hexano e que o entendimento deste equilíbrio é de fundamental importância para se tentar aumentar o rendimento e a seletividade a isômeros birramificados. / CNPq: 141042/2008-7
82

Síntese e caracterização de polímero híbrido acrílico-alquídico produzido por polimerização em miniemulsão. / Synthesis and characterization of alkyd-acrylic hybrid polymer produced by miniemulsion polymerization.

Caroline Badin 06 February 2015 (has links)
Polímeros híbridos são caracterizados por conter numa mesma partícula dois tipos diferentes de polímero, normalmente incompatíveis e ligados por ligações covalentes. Neste trabalho, a síntese de um polímero híbrido acrílico-alquídico pelo processo de miniemulsão foi investigada. Com o objetivo de compreender como diferentes variáveis na fórmula afetam as características físico-químicas finais do látex, um planejamento experimental foi desenhado com o auxílio do software DX9 e os resultados analisados por modelos empíricos de superfície de resposta. Os fatores variados (variáveis independentes) foram: quantidade de co-estabilizante, surfactante e iniciador. Cada um dos fatores contribuiu para a alteração de pelo menos uma característica avaliada, e a sinergia entre eles afeta diretamente o teor de RDG, resposta indicativa do grau de grafitização entre as espécies. O coestabilizante contribuiu para o aumento do diâmetro médio de gotas e da polidispersidade de tamanho de partículas, enquanto reduziu a dureza do filme. A concentração de surfactante alterou o número de partículas por litro, reduzindo o diâmetro médio de partículas e aumentando a polidispersidade. O iniciador aumentou a conversão monomérica. Todas as dispersões de polímero híbrido produzidas apresentaram redução do tamanho médio de gotas para partículas, indicando evidência de nucleação secundária. As avaliações por microscopia eletrônica de transmissão (TEM) e microscopia de força atômica (AFM) mostraram que a morfologia obtida é do tipo núcleo-casca. / Hybrid polymers are defined by the presence of two or more different kinds of polymers in the same particle, typically incompatible and linked by covalent bonds. In this work, the synthesis of an alkyd-acrylic hybrid polymer produced by miniemulsion polymerization has been investigated. With the goal of understanding how different variables in the recipe affect the final characteristics of the latex, a design of experiment was planned using DX9 software and the results were analyzed by response surface methodology. The factors studied (independent variables) were: amount of co-stabilizer, surfactant and initiator. Each of these factors contributed to change at least one of the evaluated characteristics, and the synergy between them directly affects the RDG content, response of the polymer degree of grafting. Costabilizer contributed to increase the average droplets diameter and polydispersity of particle size, while reducing the film hardness. The amount of surfactant changed the number of particles, reducing the average particle size and increasing polydispersity. Initiator increased the monomer conversion. All hybrids dispersions presented a decrease in the droplet size to particle size, indicating evidence of secondary nucleation. Core-shell morphology was observed through transmission electron microscopy (TEM) and atomic force microscopy (AFM).
83

Otimização de um processo de classificação de couros no estágio wet blue : um caso em uma indústria curtidora

Arriba, Gustavo de January 2005 (has links)
A melhoria de qualidade e redução de custos para produtos e processos industriais pode ser realizada utilizando-se métodos de otimização experimental. Esta dissertação apresenta um método estruturado para a otimização do processo de classificação de couro wet blue usando em forma integrada as ferramentas de Análise de Sistemas de Medição e Projeto de Experimentos aplicado a variáveis discretas. O couro sofre vários processos químicos e mecânicos até chegar no estágio final de couro acabado sendo os principais estágios; os de wet blue, semi-acabado e acabado. O primeiro deles consiste na preparação da derme para o curtimento com o objetivo de tornar o couro imputrescível. O segundo processo, que transforma o couro em um produto semi-acabado, confere as características de maciez, resistência, cor e espessura e por último no processo de acabamento se obtêm as características finais de textura, brilho, toque superficial e valores técnicos exigidos pelos clientes como resistências a fricção, flexão, solidez a luz e adesão. O principal objetivo do trabalho é otimizar o processo de classificação no estágio wet blue a fim de reduzir o índice de refugos por classificação errada no produto acabado, sem aumentar o desperdício por refugar matéria-prima na origem. O método é ilustrado com um caso em uma Indústria Curtidora da região do Vale do Sinos em Rio Grande do Sul. Historicamente, existiam refugos no produto acabado que constituíam o principal problema de qualidade da indústria e um dos fatores de maior peso no custo da não qualidade. O estudo do Sistema de Medição permitiu modelar um treinamento aplicado aos classificadores de couro e estabelecer um sistema de indicadores que permitiu acompanhar a evolução ao longo do estudo. A aplicação do Projeto de Experimentos serviu para definir a melhor prática de classificação que conduziu à diminuição de erros por classificação errada. Os dados coletados ao longo da implantação permitiram apresentar conclusões comparando a situação antes e depois. Assim, verificou-se, com a implantação das medidas sugeridas com este estudo, uma redução de 60 % no índice de refugos por classificação errada no produto acabado e semi-acabado que traduzido a valores financeiros representou 420.000 reais por ano. / Quality improvement and cost reduction for manufacturing process and products can be executed using experimental optimization methodology. This Dissertation shows a structured method to optimize the sorting process of wet blue leather using at the same time the Measure Analysis System and Design of Experiment tools, both of them applied to discrete variables. Chemical and mechanical process, are applied to the hides to get a finish leather product, being the main steps; wet blue, crust and finish. The first consists in the preparation of the skin for the tanning to avoid the rottenness of the leather. The second process, which transforms the wet blue in a crust, gives to the leather the softness, resistance, color and substance and finally, the finishing process gives the final characteristic of texture, shine, touch and technical values required by the customers, like rubbing, bending, color fastness and adhesion. The main objective of the work is to optimize the sorting process in wet blue in order to reduce the rejects due sorting errors on the finished leather without increase the waste of good material at the origin. The method is illustrated with a case in a Tannery Industry located in Vale do Sinos area in Rio Grande do Sul. Historically, there were rejects in finished leather which created the main problems of Quality and one of the causes of greater importance of non-quality cost. The Measure Analysis System allowed to model a training applied to the leather sorters and establish a group of index to follow up the evolution of the study. The application of the Design of Experiments served to define the best practice of sorting which led to the reduction of sorting errors. Conclusions were shown during the implementation obtained by the collected data, comparing the previous situation with the present. In this way it was possible to verify, with the implementation of the suggested rules, a reduction of 60 % of the rejects index caused by sorting errors which means 180.000 u$s per year.
84

Modélisation du processus de polissage : identification des effets et des phénoménologies induits par l'usinage abrasif / Modelling of the polishing process : identification of the induced effects and the phenomenology of the abrasive material removal

Goossens, François 30 November 2015 (has links)
Le polissage est un procédé d’usinage par abrasion qui vise à établir une micro-géométrieprécise sur les surfaces de solides. Pour introduire les spécificités de ce procédé, un tourd’horizon sur l’usinage par abrasion est proposé. Il en découle les paramètres pouvantcaractériser une opération de polissage. Les études scientifiques existantes sont synthétisées etanalysés au regard des objectifs poursuivis. De manière à faire émerger une méthodologiepour établir des modèles et des bases de données dédiées au polissage, un banc expérimental aété mis en place et des essais ont été menés sur une tôle en inox 316L avec un abrasifstructuré de forme pyramidale. Une méthode de mesure de l’usure des pyramides abrasives aété mise au point. Les premiers essais ont mis en évidence la nécessité pour les grains abrasifsd’exercer sur la matière une pression supérieure à une valeur minimale. Un modèle deconsommation matière issu de la loi de Preston a été présenté et validé par des essais. L’étudepar des plans d’expériences factoriels complets des efforts induits, de la rugosité au traversdes critères proposés par la norme ISO et de la mouillabilité a permis de mettre en évidencel’influence prépondérante de la taille des grains abrasifs. Par contre, la pression exercée parles grains, leur vitesse de défilement et le taux d’usure des pyramides abrasives n’ont qu’unrôle secondaire sur ces critères. Ces résultats constituent de précieuses indications pour lesbureaux des méthodes devant établir des gammes de polissage. / The polishing is a process of manufacturing by abrasion which aims at establishing a precisemicro-geometry on the surfaces of solids. To introduce the specificities of this process, anoverview on the manufacturing by abrasion is proposed. As a result, the parameters which cancharacterize an operation of polishing are identified. The existing scientific studies aresynthesized and analysed with regard to the pursued objectives. For the testing, an experimenttest bench was developed. The proposed methodology is applied on the polishing process ofthe AISI 316L using pyramidal abrasive belts. A measurement method of the abrasivepyramids wear is finalized. A method of measuring the abrasive pyramids wear is provided. Aremoving material rate model based on the Preston's law is presented and experimentallyvalidated. A study based on the design of experiment is conducted using as output the cuttingforces, the roughness and the wettability criteria. The results point out the dominatinginfluence of the size of the abrasive grains. On the other hand, the study indicates the fact thatthe applied pressure on the abrasive grains, the belt speed and the abrasive level do not playan important role on the previously cited characteristics. On the other hand, the studyhighlights that the applied pressure on the abrasive grains, the belt speed and the abrasivelevel do not have a significant effect on the previously cited characteristics. These resultsconstitute valuable indications for the industrial polishing process optimization.
85

Design et développement d'un capteur acoustique imprimé. / Design and development of printed acoustic sensor

Haque, Rubaiyet Iftekharul 20 October 2015 (has links)
L’objectif de ce travail était de concevoir et réaliser par impression un capteur acoustique capacitif résonant bas coût. Il s’inscrit dans le cadre d’un projet collaboratif de recherche intitulé « Spinnaker », défini par la société Tagsys RFID qui souhaite intégrer ce capteur afin d’améliorer la géolocalisation des étiquettes RFID. Ce travail a débuté par la conception et l’optimisation du design en utilisant la simulation par éléments finis (COMSOL) ainsi que des plans d’expériences (DOE : Design of Experiment). Cette première étape a permis de déterminer les paramètres optimaux et démontrer que les performances obtenues étaient conformes aux spécifications. Nous avons ensuite développé les différentes briques technologiques nécessaires à la réalisation des prototypes en utilisant conjointement l’impression 2D par inkjet et l’impression 3D. Nous avons vérifié la fonctionnalité de ces capteurs à l’aide de mesures électriques capacitives et acoustiques par vibrométrie laser. Nous avons démontré la sélectivité en fréquence des capteurs réalisés et comparé les résultats expérimentaux à ceux obtenus par simulation. Enfin, nous avons enfin exploré la « voie piezoélectrique » qui nous semble être une alternative intéressante au principe capacitif. En l’absence d’encre piézoélectrique commerciale imprimable par jet de matière, nous avons formulé une encre imprimable à base du co-polymère PVDF-TrFE et démontré le caractère piézoélectrique des couches imprimées. Les résultats sont prometteurs mais des améliorations doivent encore être apportées à cette encre et au procédé d’impression avant de pouvoir fabriquer des premiers prototypes. / The objective of this work was to design and fabricate a low cost resonant capacitive acoustic sensor using printing techniques. It falls within the frame of a collaborative research project named “Spinnaker”, set up by TAGSYS RFID, a French company, which has planned to integrate this sensor to improve the geolocalization of their RFID tags. This work started with the design and optimization of the sensor using finite element modeling (COMSOL) and design of experiments (DOE). This first step has enabled the identification of the optimum set of parameters and demonstrated that the output responses were in accordance with the specifications. Then, we have developed the different technological building blocks required for the fabrication of the prototypes using jointly the 2D inkjet printing technique and 3D printing method. The functionality of the sensors has been characterized using both capacitive and acoustic measurements using laser Doppler vibrometer. Experimental results showed that sensitivity and selectivity were within the specifications and in good agreement with the modeling results. Finally, we investigated the piezoelectric approach which could be an interesting option to the capacitive one. Since no inkjet printable piezoelectric ink is commercially available, stable inkjet printable polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) ink has been developed. PVDF-TrFE layers were then successfully printed and characterized. The results were quite promising, however further improvements of the ink and printing process are required before stepping towards piezoelectric based device fabrication.
86

The Effect of Microcrystalline Cellulose as cushioning excipient during controlled release

Jansson, Felisa January 2017 (has links)
In the pharmaceutical industry, it is always important to have reproducible processes and raw materials of high quality to ensure good quality products. AstraZeneca, that is a leading manufacturer of different pharmaceuticals, works according to GMP to make sure that their processes deliver products of the same quality every time. A problem that has occurred at AstraZeneca is when a raw material is not properly understood and variations in the raw material affects the final product. Variations in drug release in one of AstraZeneca´s products, Product X, has been linked to the cushioning excipient Microcrystalline cellulose (MCC). Variations in drug release has been noticed during change from one batch of MCC to another. The aim of this study was to investigate which material attributes of MCC that contributes to variations in the final product. Particle size and moisture content were identified as critical material attributes (CMA´s) and were therefore chosen to be investigated more thoroughly. By variating particle size and moisture content during manufacturing of Product X, the influence of these attributes could be investigated using Design of Experiment (DoE). An additional experiment that compared two MCC batches from different suppliers was also performed during this study. The results from these experiments showed that the particle size and moisture content of MCC does affect the drug release. Large particles and high moisture content gave rise to a faster drug release compared to small particles and low moisture content that gave rise to a slower drug release. It is however hard to draw conclusions regarding how small differences in particle size and moisture content could affect the drug release.
87

Relations composition – structure – propriétés des verres peralumineux pour le conditionnement des déchets nucléaires / Composition – structure – properties relationships of peraluminous glasses for nuclear waste containment

Piovesan, Victor 03 November 2016 (has links)
Dans le cadre de la recherche sur le conditionnement des déchets nucléaires issus des combustibles usés, de nouvelles formulations vitreuses sont à l’étude. Ces nouvelles matrices doivent être capables d’incorporer une importante teneur en produits de fission et actinides mineurs (PFA) tout en présentant d’excellentes propriétés en termes d’homogénéité, stabilité thermique, comportement à long terme et faisabilité technologique. Cette étude s’intéresse aux verres dits « peralumineux », c’est-à-dire à des verres présentant un excès d’ions aluminium vis-à-vis des ions compensateurs de charges (Na⁺, Li⁺ et Ca²⁺). Une approche par plan d’expériences a été réalisée afin de déterminer les relations entre la composition de systèmes peralumineux simplifiés à sept oxydes (SiO2 – B2O3 – Al2O3 – Na2O – Li2O – CaO – La2O3) et leurs propriétés physico-chimiques : viscosité, température de transition vitreuse et microstructure. Une étude structurale réalisée par spectroscopie RMN a également permis de mieux définir les rôles structuraux de Na⁺, Li⁺ et Ca²⁺ au sein des verres peralumineux ainsi que l’organisation structurale de ces matrices. Par la suite, des verres peralumineux complexes ont été élaborés et caractérisés afin d’une part, de valider la transposition des résultats entre verres simplifiés et verres complexes et d’autre part, de souligner la potentialité des verres peralumineux comme matrice de conditionnement. / Part of the Research and Development program concerning high level nuclear waste conditioning aims to assess new glass formulations able to incorporate a high waste content with enhanced properties in terms of homogeneity, thermal stability, long term behavior and process ability. This study focuses on peraluminous glasses, defined by an excess of aluminum ions Al³⁺ in comparison with modifier elements such as Na⁺, Li⁺ or Ca²⁺. A Design of Experiment approach has been employed to determine relationships between composition of simplified peraluminous glasses (SiO2 – B2O3 – Al2O3 – Na2O – Li2O – CaO – La2O3) and their physical properties such as viscosity, glass transition temperature and glass homogeneity. Moreover, some structural investigation (NMR) was performed in order to better understand the structural role of Na⁺, Li⁺ and Ca²⁺ and the structural organization of peraluminous glasses. Then, physical and chemical properties of fully simulated peraluminous glasses were characterized to evaluate transposition between simplified and fully simulated glasses and also to put forward the potential of peraluminous glasses for nuclear waste containment.
88

Optimalizace řídicích parametrů EDM stroje / Optimization of EDM process control parameters

Prokeš, Tomáš January 2021 (has links)
The dissertation thesis is focused on the optimization of control parameters of an EDM machine; the subject of optimization is cutting speed and surface topography. The first part of the thesis contains a research study on the technology of electrical discharge machining with the attention paid to the optimization methods use for control parameters of this process. The second part of the thesis is focused on real application of knowledge gained from studied sources. Here, a design of experiment aim at optimizing the parameters of the EDM machine is designed and carried on to maximize the cutting speed with the highest possible surface quallity. The result of the work is to build adequate regression models and find the optimal setting of machine control parameters.
89

Optimalizace procesu lakování / Optimization of painting process

Siegl, Pavel January 2008 (has links)
The diploma is focused on optimizing of rating during the process of painting by means of experimental methods and statistic analysis. Description of the study of the present state of painting process, result analysis and the project of optimal pre-set in practice.
90

Analýza teplotního pole vysokonapěťového rozvaděče / High Voltage Switchgear Thermal Distribution Analysis

Bílek, Tomáš January 2015 (has links)
Cílem této práce je analýza teplotního pole vysokonapěťového rozvaděče. Tato analýza je založena na kombinaci experimentálního měření a CFD simulace proudění vzduchu v prostoru rozvaděče. Na základě výsledků pro referenční geometrii jsou předloženy návrhy na úpravu topologie rozvaděče, které mají za cíl snížení teploty kritických komponent rozvaděče během jeho provozu. Druhá část práce je spojena s problematikou oteplení plošných spojů, jakožto hlavních zdrojů tepla v prostoru rozvaděče. Pro popis závislosti oteplení plošného spoje na jeho charakteru byla použita statistická metoda design experimentu. Výsledky z experimentálního měření jsou podpořeny konečně prvkovým modelem kontaktu spoje.

Page generated in 0.0331 seconds