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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.
71

João Kopke e a escola republicana: criador de Lleituras, escritor da modernidade / João Köpke and the republican school: creator of lectures, writer of modernity

Silva, Claudia Panizzolo Batista da 31 July 2006 (has links)
Made available in DSpace on 2016-04-27T16:33:11Z (GMT). No. of bitstreams: 1 Tese CLAUDIA PANIZZOLO.pdf: 7808983 bytes, checksum: 3dcfd2b62d272785045bb9dfd4c87bbd (MD5) Previous issue date: 2006-07-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This work in a historiographic study of the intellectual and professional trajectory of João Kopke [ 1852 1926 ] educator involved in the republican cause, marked by an innovative and creative restlessness, by a coherence of principles and by the pioneerism in the divulgation of modern ideas and pedagogical practices. A multifaceted intellectual and one of the most significant educators of his generation to put in circulation, in the press and in the schools where he worked, a modern and republican pedagogy defined by an updated curriculum, practical, concrete and scientific teaching; an intuitive methodology through lessons of things; serial, graduated and simultaneous classes; extra-class activities ; popular and pedagogical lectures and by the analytical teaching of reading from a long time deserved a more detailed study that would consider him inside the frame pictures of the History of Education . To take him from forgetfulness, to study the educator, to focus the singularities of Joao Köpke as an intelectual of Education and at the same time, to examine his preoccupation and challenges , the polemics assumed by him and by his co-workers is what this research aims for. The investigation about his intellectual trajectory, the study of the schools where he worked, the analysis of his first reader books , of his lectures and of his reading books, destined to elementary and high school teaching, as well as the exam of the pieces of news published about his multiple activities in São Paulo and Rio de Janeiro show that João Köpke was moved by a political and intellectual project well characteristical , an assurance of a unity of sense, present in his attitudes and in the writings that he developed for more than fifty years / Este trabalho é um estudo historiográfico da trajetória intelectual e profissional de João Köpke (1852-1926), educador envolvido com a causa republicana, marcado pela inquietação criadora e renovadora, pela coerência de princípios e pelo pioneirismo na divulgação das modernas idéias e práticas pedagógicas. Intelectual de múltiplas faces e um dos mais significativos educadores de sua geração a pôr em circulação, na imprensa e nas escolas por onde passou, uma pedagogia moderna e republicana - definida por um currículo atualizado, ensino prático, concreto e científico; metodologia intuitiva, através de lições de coisas; aulas seriadas, graduadas e simultâneas; atividades extraclasse; conferências populares e pedagógicas e pelo ensino analítico da leitura -, há muito merecia um estudo mais detalhado que o considerasse dentro dos quadros da História da Educação. Retirar do esquecimento, estudar o educador, evidenciar a singularidade de João Köpke como intelectual da educação e, ao mesmo tempo, examinar as preocupações, os desafios, as polêmicas assumidas por ele e sua rede de relações é o que pretende esta pesquisa. A investigação a respeito de sua trajetória intelectual, o estudo dos estabelecimentos escolares onde trabalhou, a análise de suas cartilhas, de suas conferências e de seus livros de leitura, destinados ao ensino primário e secundário, bem como o exame das notícias dos jornais veiculadas a respeito de suas múltiplas atividades, em São Paulo e no Rio de Janeiro, mostram que João Köpke era movido por um projeto político-intelectual bastante característico, garantia de uma unidade de sentido presente em suas atitudes e nos escritos que desenvolveu por mais de cinqüenta anos
72

Transducteurs ultrasonores capacitifs multiéléments à couplage air pour un contrôle non destructif à focalisation dynamique de matériaux : modélisation, simulations numériques et expériences / Multi-element air-coupled capacitive ultrasonic transducer with dynamic focusing for non-destructive testing of materials : modelling, numerical simulations and experiments

Zhang, Di 20 November 2013 (has links)
Cette thèse porte sur le développement d'un traducteur ultrasonore multi-élément capacitif à couplage air (MEACUT) et son utilisation dans le domaine du contrôle non destructif (CND) de matériaux. Un modèle est employé pour simuler numériquement ce traducteur, et pour optimiser sa conception. Un prototype est ensuite fabriqué, puis caractérisé expérimentalement pour quantifier ses performances. Son originalité réside dans le fait qu'il possède une large bande passante en fréquence, tout en offrant la possibilité d'une focalisation variable. Ce prototype est alors employé pour la détection d'un endommagement causé par impact, dans une plaque composite. Il est clairement constaté que la résolution spatiale du procédé d'inspection employé (C-scan) est fortement améliorée grâce aux performances techniques du MEACUT. Enfin, un modèle hybride 3D est développé pour simuler, rapidement et intégralement, ce procédé de CND. Le très bon accord obtenu entre prédictions numériques et mesures expérimentales laisse présager que cet outil de simulation pourra servir à mettre au point d'autres expérimentations de CND, qui pourront à leur tour exploiter les performances du MEACUT. / This thesis focuses on the development of a Multi-Element Air-coupled Capacitive Ultrasonic Transducer (MEACUT) and its use in the field of non-destructive testing (NDT) of materials. A numerical model is used to simulate the translator, and to optimize its design. A prototype is then built and experimentally characterized to quantify its performance. Its originality lies in the fact that it has a broad frequency bandwidth while offering the possibility of a dynamic focusing. This prototype is then used for the detection of damage caused by impact, in a composite plate. It is clearly found that the spatial resolution of the inspection process employed (C-scan) is greatly improved thanks to the technical performance MEACUT. Finally, a 3D hybrid model is developed to simulate quickly and fully, the process of NDT. The good agreement obtained between numerical predictions and experimental measurements suggests that this simulation tool can be used to develop other NDT experiments, which may in turn exploit the performance of MEACUT.
73

Determining Performance of Channel Decoders / Одређивање перформанси декодера заштитних кодова / Određivanje performansi dekodera zaštitnih kodova

Minja Aleksandar 23 January 2019 (has links)
<p>This thesis contains some of the results obtained by the author in the course of his<br />postgraduate research in the fields of Communication system modeling and<br />Information and coding theory. The results are presented in mathematical form and are<br />verified by numerical simulations. Most of them are motivated by challenges arising in<br />the design and standardization of 5G communication systems and are of practical and<br />scientific relevance. Main contributions of the thesis are divided into two parts. In the<br />first part of this thesis we introduce a novel SNR-invariant quasi-analytical technique<br />for estimating the error rate of a communication link over the geodesic channel. We<br />compared this technique to the Monte Carlo and Importance Sampling methods and it<br />has been found out that it outperforms other methods in both accuracy and speed. In<br />the second part of the thesis we introduce an optimization procedure, based on the<br />variable force repulsion method, for the design of spherical codes that are tailored to<br />the TCM and achieve lower error rates at high SNR, then their counterparts that are<br />optimized for minimum distance. The performance of these codes is verified using the<br />method developed in part I of this thesis which is suitable for simulating error rates at<br />high SNR.</p> / <p>Ова дисертација садржи неке од резултата аутора добијених током његовог<br />постдипломског истраживања у областима моделовања комуникационих система<br />и теорије информација и заштитног кодовања. Резултати су представљени у<br />математичком формату и верификовани су нумеричким симулацијама. Већина<br />њих је мотивисана проблемима који се појављују приликом развоја и<br />стандрадизације 5G комуникационих система и имају велики научни и практични<br />значај. Дисертација је подељена у два дела. Први део уводи нови<br />квазианалитички поступак за естимацију вероватноће грешке декодера<br />заштитних кодова. Математички је показано и експериментално потврђено да је<br />нови симулациони поступак значајно брзи од постојећих симулационих<br />постпупака (монте карло и поступак узорковања по значајности) који се користе у<br />пракси. У другом делу тезе представљен је проблем конструкције<br />вишедимензионалне трелис кодоване модулације (енг. Trellis Coded<br />Modulation - TCM) помоћу сферичних кодова. Развијен је нови алгоритам за<br />конструкцију сферичних кодова који су прилагођени структури TCM кода и<br />показано је да такви TCM кодови имају знатно боље перформансе од постојећих.<br />Вероватноћа грешке ових нових TCM кодова је естимирана применом<br />симулационог поступка који је дат у првом делу дисертације.</p> / <p>Ova disertacija sadrži neke od rezultata autora dobijenih tokom njegovog<br />postdiplomskog istraživanja u oblastima modelovanja komunikacionih sistema<br />i teorije informacija i zaštitnog kodovanja. Rezultati su predstavljeni u<br />matematičkom formatu i verifikovani su numeričkim simulacijama. Većina<br />njih je motivisana problemima koji se pojavljuju prilikom razvoja i<br />standradizacije 5G komunikacionih sistema i imaju veliki naučni i praktični<br />značaj. Disertacija je podeljena u dva dela. Prvi deo uvodi novi<br />kvazianalitički postupak za estimaciju verovatnoće greške dekodera<br />zaštitnih kodova. Matematički je pokazano i eksperimentalno potvrđeno da je<br />novi simulacioni postupak značajno brzi od postojećih simulacionih<br />postpupaka (monte karlo i postupak uzorkovanja po značajnosti) koji se koriste u<br />praksi. U drugom delu teze predstavljen je problem konstrukcije<br />višedimenzionalne trelis kodovane modulacije (eng. Trellis Coded<br />Modulation - TCM) pomoću sferičnih kodova. Razvijen je novi algoritam za<br />konstrukciju sferičnih kodova koji su prilagođeni strukturi TCM koda i<br />pokazano je da takvi TCM kodovi imaju znatno bolje performanse od postojećih.<br />Verovatnoća greške ovih novih TCM kodova je estimirana primenom<br />simulacionog postupka koji je dat u prvom delu disertacije.</p>
74

Modélisation avancée du contact pneu-chaussée pour l'étude des dégradations des chaussées en surface / Advanced Modeling of Tire-Pavement Contact to Investigate Pavement Surface Degradation

Manyo, Edem Yawo 14 February 2019 (has links)
L'apparition récente de nouveaux matériaux dans les structures de chaussée associée à une diminution de l'épaisseur des couches de surface et une augmentation du chargement des poids lourds et de leur fréquence de passage a entrainé de nouvelles pathologies de dégradation. Outre les problèmes d'orniérage bien connus, apparaissent désormais des fissures descendantes (top down cracking) ainsi que des problèmes de décohésion aux interfaces. Ces nouvelles pathologies entrainent des dépenses considérables sur l'ensemble du réseau (environ 15 milliards d'euros par an), particulièrement en zones urbanisées plus sujettes aux dégradations de surface et ne permettent pas d'estimer convenablement les durées de vie de la chaussée, le plus souvent surestimée dans les méthodes de dimensionnement actuelles. Ce travail de doctorat propose une nouvelle approche du contact pneu-chaussée permettant de mieux appréhender les contraintes principales et résiduelles dans une structure de chaussée bitumineuse. A l'aide d'un outil numérique rapide de calcul basé sur une approche semi-analytique (« Semi-Analytical Methods » (SAM)), la géométrie précise du pneumatique est intégrée afin d'obtenir une répartition de pression de contact ainsi qu'un cisaillement surfacique réelle sur la chaussée. Dans un premier temps, un modèle de contact roulant tractif élastique est implémenté pour des cas théoriques simples et validé par des résultats analytiques et numériques de la littérature. Ensuite, ce modèle est étendu pour prendre en compte le comportement élasto-plastique des corps en contact. Ce dernier est comparé à un résultat numérique basé sur la méthode des éléments finis issu de la littérature. Les résultats, pour une application contact pneu-chaussée, montrent une répartition non homogène des contraintes dans la structure et principalement dans les premiers centimètres sous la surface avec des niveaux beaucoup plus importants que peuvent le prédire les modèles actuels qui utilisent une charge uniformément répartie. La pression de contact est comparée aux mesures effectuées par un système nommé TekScan et les champs mécaniques en sous couches sont comparés à ceux d'Alizé-LCPC dans le cas d'une structure simple. Les cisaillements surfaciques sont déterminés dans le cas du roulement tractif. Une application est effectuée sur la modélisation des dégradations des chaussées en surface. Dans un premier temps, des analyses sur le comportement de la chaussée en surface sont effectuées pour une couche de béton bitumineux semi grenu (BBSG) semi-infinie supposée élastique, homogène sous conditions d'accélération, de freinage et de virage. Pour des études sur le top down cracking, des déformations et directions principales sont déterminées et analysées. Ensuite, le modèle de contact élasto-plastique est appliqué sur une couche semi-infinie de grave bitume GB3. Des déformations et contraintes résiduelles générées dans la structure sont déterminées en vue d'une analyse sur les ornières d'instabilité. Une fois validés, ces résultats permettront d'estimer plus fidèlement la durée de vie résiduelle des chaussées mais également de comprendre et d'éviter les mécanismes de dégradation en surface ou proche de la surface. / The recent appearance of new materials in road structures associated with surface layers thickness decreasing and the increasing of trucks loading and their passage frequency has led to new pathologies of degradation. In addition to the well-known rutting problems, top down cracking is now appearing as well as problems of decohesion at the interfaces. These new pathologies led to considerable expenditure on the entire network (around 15 billion euros per year), particularly in urbanized areas that are more prone to surface damage and do not make it possible to adequately estimate the lifetimes of the roadway, most often overestimated in current design methods. This doctoral work proposes a new approach of the tire-road contact allowing for better apprehend of the main and residual stresses in a bituminous pavement structure. Using a fast numerical tool based on a semi-analytical approach ("Semi-Analytical Methods" (SAM)), the precise geometry of the tire is integrated in order to obtain a real contact pressure distribution as well as surface shear on the pavement surface. Initially, an elastic tractive rolling contact model is implemented for simple theoretical cases and validated by analytical and numerical results from the literature.Then, this model is extended to take into account the elastoplastic behavior of the bodies in contact. This is compared to a numerical result based on the nite element method from the literature. The application for tire-pavement contact results, show a non-uniform distribution of stresses in the structure and mainly in the rst centimeters below the surface with much higher levels than can be predicted by current models that use a uniformly distributed load. The contact pressure is compared to the measurements made by a system called TekScan and the mechanical elds in sublayers are compared to those of Alizé-LCPC in the case of a simple structure. The surface shears are determined in the case of tractive rolling. An application is carried out on the modeling of surface pavement damage. Firstly, analyzes of the behavior of the surface pavement are carried out for a semi-innite semi-grit asphalt concrete layer supposed to be elastic, homogeneous under conditions of acceleration, braking and turning. For studies on top down cracking, principals deformations and directions are determined and analyzed. Then, the elastoplastic contact model is applied on a semi-innite asphalt agragate layer. Deformations and residuals stresses generated in the structure are determined for an analysis on the instability ruts. Once validated, these results will make it possible to more accurately estimate the residual life of pavements but also to understand and avoid surface or near surfacedegradation mechanisms.
75

Caractérisation de la toxicocinétique de l’octylphénol chez le rat en vue d’une meilleure analyse de risque toxicologique des perturbateurs endocriniens

Hamelin, Geneviève 04 1900 (has links)
Le p-tert-octylphénol est un produit présent dans l’environnement et issu de la dégradation des alkylphénols éthoxylés. Ce composé a la capacité de se lier au récepteur œstrogénique et d’exercer ainsi un léger effet œstrogénique. Les objectifs de cette étude étaient de 1) développer une méthode d'identification de l'octylphénol dans le sang et les tissus à l'aide de la chromatographie en phase gazeuse jumelée à la spectrométrie de masse, 2) caractériser la toxicocinétique sanguine et tissulaire de l’octylphénol chez le rat Sprague-Dawley mâle et femelle et 3) développer un modèle toxicocinétique à base physiologique permettant de décrire la cinétique sanguine et tissulaire de l’octylphénol inchangé. Pour ce faire, des rats mâle et femelle Sprague-Dawley ont reçu des doses uniques d’octylphénol par les voies intraveineuse, orale et sous-cutanée. Deux autres groupes ont reçu des doses répétées d'octylphénol par voie orale pour une durée de 35 jours consécutifs pour les femelles ou 60 jours pour les mâles. Les concentrations sanguines et tissulaires d’octylphénol ont été mesurées à différents moments après administration à partir d’une méthode d’analyse développée dans nos laboratoires dans le cadre de ce projet. Les expériences impliquant des administrations uniques ont montré que les concentrations sanguines et tissulaires d'octylphénol étaient en général plus élevées chez les femelles que chez les mâles. Des expériences réalisées avec des microsomes hépatiques ont confirmé que ces différences étaient vraisemblablement reliées au métabolisme de l'octylphénol. Les expériences impliquant des administrations répétées ont montré qu'il n'y avait pas d'accumulation d'octylphénol dans l'organisme aux doses étudiées. Les résultats obtenus expérimentalement ont servi à développer et valider un modèle toxicocinétique à base physiologique. Ce modèle a permis de simuler adéquatement les concentrations sanguines et tissulaires d'octylphénol suite à des expositions intraveineuses, orales et sous-cutanées. En conclusion, cette étude a fourni des données essentielles sur la toxicocinétique de l'octylphénol. Ces données sont nécessaires pour établir la relation entre la dose externe et la dose interne et vont contribuer à une meilleure évaluation des risques liés à l'octylphénol. / p-tert-Octylphenol is a degradation product of alkylphenol ethoxylates that can be found in the environment. It has been reported to act as a weak estrogenic compound by binding to the estrogen receptor. This study was undertaken to 1) develop a sensitive method for the determination of octylphenol in blood and various tissues using gas chromatography coupled with detection by mass spectrometry, 2) characterize the blood and tissues toxicokinetics of octylphenol in male and female Sprague-Dawley rats and 3) develop a physiologically-based toxicokinetic model for octylphenol that can describe/predict unchanged blood and tissues octylphenol concentrations in rats. Male and female Sprague-Dawley rats were given a single dose of octylphenol either by oral gavage, intravenous injection or subcutaneous injection. In a repeated dosing experiment, rats were given octylphenol (oral) daily for 35 days (female) or 60 days (male). Blood and tissue samples were collected at various time following the onset of exposure and analyzed for octylphenol content using a method developed in our laboratory. These results showed that blood and tissues octylphenol concentrations were generally higher in female than male rats. Experiments done with rat liver microsomes confirmed that these differences were related to octylphenol metabolism. The results of the repeated exposure study indicate that there is no bioaccumulation of octylphenol at these exposure levels. A physiologically-based pharmacokinetic model for octylphenol was developed and validated using the data obtained in female and male rats. The model simulates adequately blood and tissues octylphenol concentrations following oral, intravenous or subcutaneous exposure. In conclusion, this study provided essential data on the toxicokinetics of octylphenol. These data are essential to predict the relationship between the internal and the external dose of octylphenol and will facilitate the risk assessment of octylphenol in humans.
76

Modelling and improvement of complex nonlinear plasmonic waveguides / Modélisation et amélioration des guides d'onde plasmoniques non-linéaires complexes

Elsawy, Mahmoud Mohamed Reda Ahmed 28 September 2017 (has links)
Le but de cette thèse est de développer les outils numériques et semi-analytiques qui nous permettent d’étudier des guides non-linéaires complexes et réalistes qui pourraient être fabriqués et caractérisés expérimentalement.Nous présentons une étude complète d’une version améliorée du guide d’onde plasmonique non-linéaire à une dimension, en ajoutant deux couches tampons de diélectrique linéaire entre le cœur non-linéaire isotrope et les deux gaines métalliques. Ses couches réduisent les pertes et permettent leur diminution avec la puissance contrairement aux guides simples. De plus, les principaux modes plasmoniques non-linéaires peuvent présenter une transition spatiale vers des modes de types différents, qui peut être contrôlée par la puissance.Par la suite, nous étudions un nouveau guide plasmonique non-linéaire à fente utilisant un métamatériau, soit dans le cœur non-linéaire soit dans les gaines linéaires. Nous avons mis au point une méthode semi-analytique et une méthode numérique afin d’étudier les solutions stationnaires non-linéaires dans ce nouveau guide non-linéaire anisotrope. Nous avons montré analytiquement et numériquement que le cœur non-linéaire anisotrope peut être conçu afin d’atteindre de forts effets non-linéaires à faible puissance. Pour certains métamatériaux dans les gaines linéaires, la figure de mérite de ce guide d’onde augmente de plus de 50 fois par rapport aux guides isotropes.Pour conclure, nous présentons une nouvelle méthode basée sur la méthode des éléments finis de type vectoriel couplée à l’algorithme à puissance fixée pouvant calculer rigoureusement les effets non-linéaires dans des guides d’onde plasmoniques 2D. / The main goal of this PhD is to develop the semi-analytical and the numerical tools that allow us to study complicated and realistic nonlinear plasmonic waveguides which can be fabricated and characterized experimentally.First, we present a full study of an improved version of the one-dimensional nonlinear plasmonic slot waveguide, by adding two linear dielectric buffer layers between the isotropic nonlinear core and the two metal claddings. These additional layers reduce the overall losses and allow the losses to decrease with the power for some configurations unlike the usual slot. Furthermore, the main plasmonic modes can exhibit nonlinear spatial modal transitions towards new families of modes that can be controlled with the power.Second, we propose and study new one-dimensional nonlinear plasmonic slot waveguides with metamaterial regions either in the nonlinear core or in the linear claddings. For the metamaterial nonlinear core, we developed semi-analytical and fully numerical methods in order to study the nonlinear stationary solutions propagating in this anisotropic nonlinear waveguide. We have demonstrated both analytically and numerically that the anisotropic nonlinear core can be designed in order to achieve strong nonlinear effects at low power.For the structures with metamaterial linear claddings, the figure of merit can be extremely enhanced by more than 50 times compared with the simple one. Finally, we present the full derivation of a new nonlinear full vectorial finite element method based on the fixed power algorithm in order to quantify rigorously the nonlinear characteristics of realistic two-dimensional nonlinear plasmonic structures.
77

Desenvolvimento e validação de metodologia cromatográfica para determinação de bisfenol A em simulantes de alimentos de ensaios de migração / Development and validation of chromatographic method for the determination of bisphenol A in food simulants of migration tests.

Linhares Junior, Gilberto Ferreira January 2012 (has links)
LINHARES JUNIOR, Gilberto Ferreira. Desenvolvimento e validação de metodologia cromatográfica para determinação de bisfenol A em simulantes de alimentos de ensaios de migração. 2012. 101 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Tecnologia de Alimentos, Fortaleza-CE, 2012 / Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-06-08T15:09:14Z No. of bitstreams: 1 2012_dis_gflinharesjunior.pdf: 1691103 bytes, checksum: 0abb8d914beb4b36dee06bc962679c7b (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-06-08T15:09:30Z (GMT) No. of bitstreams: 1 2012_dis_gflinharesjunior.pdf: 1691103 bytes, checksum: 0abb8d914beb4b36dee06bc962679c7b (MD5) / Made available in DSpace on 2016-06-08T15:09:30Z (GMT). No. of bitstreams: 1 2012_dis_gflinharesjunior.pdf: 1691103 bytes, checksum: 0abb8d914beb4b36dee06bc962679c7b (MD5) Previous issue date: 2012 / This study aimed to develop and chromatographic method for the determination of bisphenol A in four different food simulants using high performance liquid chromatography and diode array detector (PDA) to support in enasios migration. The simulating used were A (purified water), B (solution aquosade 3% acetic acid), C (aqueous 10% ethanol) and D (aqueous 95% ethanol). Preliminary assessment of the analytical conditions was conducted in order to establish those that confer the best results, which were the system of mobile phase acetonitrile-water in the ratio 70:30 by volume, 40 ° C oven and length of the column wavelength of 201 nm. The retention time of the bisphenol A was found to be 3.25 minutes. For simulating the method of treatment consists of evaporation of sample 1 ml of sample at 60 ° C with duration of 1 hour and 45 minutes (A and C), 2 hours (B) and 1 hour (D). In sequence, the method was evaluated with respect to the parameters of analytical validation, including linearity, limit of detection and quantification, repeatability, intermediate precision between different analysts and between different days, recovery, selectivity and robustness. The method for simulating the coefficient for determining (r ²) or greater than 0.9988 in the range tested (50 to 2000 ppb); detection limit and quantitation, respectively, 14.7 ppb and 48.9 ppb; coefficient variation in repeatability of 2.07% for the inter-day precision of 1.05% and the accuracy of inter-Analyst 1.76%, recovery of 97.9% (CV = 1.3%) (50 ppb ), 99.2% (CV = 0.7%) (1000 ppb) and 103.6% (CV = 0.4%). The results for the simulant B includes coefficient of determination (r ²) 0.9972 or higher; limit of detection and quantification, respectively, 7.8 ppb and 26.0 ppb; coefficients of variation for repeatability of 3.74%, inter day precision, accuracy and 0.14% cross-Analyst 0.2%, 94.8% recovery (CV = 4.8%) (50 ppb) and 99.8% (CV = 0.2% ) (1000 ppb) and 92.3% (CV = 1.2%) (2000 ppb). For the simulant C results include a coefficient of determination (r ²) 0.9988 or higher; limit of detection and quantification, respectively, 4.8 ppb and 16.1 ppb, coefficient of variation for repeatability of 2.84%, accuracy inter-day precision of 1.37% and inter-analysts of 0.14%; de104 recovery, 6% (CV = 2.5%) (50 ppb), 99.8% (CV = 1.3%) ( 1000 ppb) to 102.5% (CV = 2.9%) (2000 ppb). The results for simulating D was 0.9984 r ² or more, detection limit and quantitation, respectively, 13.7 ppb and 45.6 ppb; coefficient of variation of 2.0% to repeatability, accuracy of an inter-day 9% and accurate inter-de1 analysts, 2%; recuperção 92.6% (CV = 1.76%) (50 ppb) and 99.9% (CV = 0.9%) (1000 ppb) and 104 8% (CV = 2.7%) (2000 ppb). There were no significant interferences to the method tested and proved to be robust. / Este trabalho teve como objetivo o desenvolvimento e metodologia cromatográfica para a determinação de bisfenol A em quatro diferentes simulantes de alimentos utilizando cromatografia líquida de alta eficiência e detector de arranjo de diodo (PDA) para suporte em enasios de migração. Os simulantes utilizados foram A (água purificada), B (solução aquosade ácido acético a 3%), C (solução aquosa de etanol a 10%) e D (solução aquosa de etanol a 95%). A avaliação preliminar das condições de análise foi conduzida com a finalidade de estabelecer aquelas que conferem os melhores resultados, os quais foram o sistema de fase móvel acetonitrila-água na proporção volumétrica 70:30, temperatura de 40°C do forno da coluna e comprimento de onda em 201 nm. O tempo de retenção do bisfenol A encontrado foi de 3,25 minutos. Para os simulantes, o método de tratamento consistiu da evaporação de 1 ml de amostra amostra a 60°C com duração de 1 hora e 45 minutos (A e C), 2 horas (B) e 1 hora (D). Em sequência, o método foi avaliado com relação aos parâmetros de validação analítica, incluindo linearidade, limite de detecção e de quantificação, repetibilidade, precisão intermediária entre analistas diferentes e entre dias diferentes, recuperação,seletividade e robustez. O método desenvolvido para o simulante A apresentou coeficiente de determinação (r²) 0,9988 ou superior no intervalo testado (50 a 2000 ppb); limite de detecção e de quantificação , respectivamente, 14,7 ppb e 48,9 ppb; coeficiente de variação para repetibilidade de 2,07%, para a precisão inter-dias de 1,05% e para a precisão inter-analistas de 1,76%; recuperação de 97,9% (CV= 1,3%) (50 ppb), 99,2% (CV= 0,7%) (1000 ppb) e 103,6% (CV= 0,4%). Os resultados obtidos para o simulante B incluem coeficiente de determinação (r²) 0,9972 ou superior; limite de detecção e de quantificação, respectivamente, 7,8 ppb e 26,0 ppb; coeficientes de variação para repetibilidade de 3,74%, precisão inter-dias de 0,14% e precisão inter-analistas de 0,2%; recuperação de 94,8% (CV= 4,8%) (50 ppb), 99,8% (CV= 0,2%) (1000 ppb) e 92,3% (CV= 1,2%) (2000 ppb). Para o simulante C os resultados incluem coeficiente de determinação (r²) 0,9988 ou superior; limite de detecção e de quantificação, respectivamente, 4,8 ppb e 16,1 ppb; coeficiente de variação para repetibilidade de 2,84%, precisão inter-dias de 1,37%e precisão inter-analistas de 0,14%; recuperação de104,6% (CV= 2,5%) (50 ppb), 99,8% (CV= 1,3%) (1000 ppb) e 102,5% (CV= 2,9%) (2000 ppb). Os resultados para o simulante D foram r² 0,9984 ou superior; limite de detecção e de quantificação,respectivamente, 13,7 ppb e 45,6 ppb; coeficiente de variação para repetibilidade de 2,0%, precisão inter-dias de 1,9% e precisão inter-analistas de1,2%; recuperção de 92,6% (CV= 1,76%) (50 ppb), 99,9% (CV= 0,9%) (1000 ppb) e 104,8% (CV= 2,7%) (2000 ppb). Não foram observados interferentes importantes para o método testado, mostrando-se robusto.
78

Série leituras infantis (1908-1919), de Francisco Vianna e a história do ensino da leitura no Brasil

Oriani, Angélica Pall [UNESP] 14 December 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-12-14Bitstream added on 2014-06-13T20:17:50Z : No. of bitstreams: 1 oriani_ap_me_mar.pdf: 1888448 bytes, checksum: c5af3389ad16a7c27cea3678e32d3d64 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Nesta dissertação, apresentam-se resultados de pesquisa de Mestrado em Educação (Bolsa CNPq – abril de 2009 a fevereiro de 2010; Bolsa Fapesp – março a dezembro de 2010), vinculada às linhas Alfabetização e Ensino de língua portuguesa do Grupo de Pesquisa e Projeto Integrado de Pesquisa História do Ensino de Língua e Literatura no Brasil, ambos coordenados por Maria do Rosário Longo Mortatti. Com o objetivo de contribuir para a produção de uma história do ensino de língua e literatura no Brasil, focalizou-se a proposta para o ensino de leitura apresentada pelo professor Francisco Furtado Mendes Vianna (1876-1935) nos livros didáticos que integram a Série Leituras Infantis, a saber: Cartilha: leituras infantis [1912?]; Primeiros passos na leitura (1915); Leitura preparatória (1908); Primeiro livro de leituras infantis; Segundo livro de leituras infantis; Terceiro livro de leituras infantis; e Quarto livro de leituras infantis (Apanhados e factos hitóricos) (1919). Os livros que integram essa série foram publicados pela Livraria Francisco Alves (RJ), com sucessivas edições até pelo menos a década de 1960, tendo circulado em diferentes estados brasileiros: São Paulo, Rio de Janeiro, Mato Grosso, Espírito Santo, Paraná, Pará, Amazonas, Ceará, Minas Gerais, Santa Catarina e Rio Grande do Sul. Mediante abordagem histórica centrada em pesquisa documental e bibliográfica, desenvolvida por meio dos procedimentos de localização, recuperação, reunião, seleção e ordenação de fontes documentais e de leitura da bibliografia especializada sobre o tema, elaborou-se um instrumento de pesquisa contendo a bibliografia de e sobre Francisco Vianna e analisou-se a configuração textual dos livros que integram essa série, que consiste em enfocar os diferentes aspectos constitutivos de seu sentido. Concluiu-se que nos livros que integram essa série é apresentada... / This work deals with the results of a Master degree dissertation research (CNPq schoolarship – april 2009 to february 2010; Fapesp schoolarship – march to december 2010), related to “Literacy” and “Portuguese Language” of Research Group and Research Integrated Project “History of Language and Literature Teaching in Brazil” both under the leadership of Maria do Rosário Longo Mortatti. Aiming contributing to understand an important moment of the history of reading teaching in Brazil, it focus on the proposal concerning reading teaching presented by professor Francisco Furtado Mendes Vianna (1876-1935), in the didactic books called Série Leituras Infantis, that are: Cartilha: leituras infantis [1912?]; Primeiros passos na leitura (1915); Leitura preparatória (1908); Primeiro livro de leituras infantis; Segundo livro de leituras infantis; Terceiro livro de leituras infantis; e Quarto livro de leituras infantis (Apanhados e factos hitóricos) (1919). All those books were published by Livraria Francisco Alves (RJ) with successive edition until at least the 1960 and had circulated in different Brazilian state: São Paulo, Rio de Janeiro, Mato Grosso, Espírito Santo, Paraná, Pará, Amazonas, Ceará, Minas Gerais, Santa Catarina e Rio Grande do Sul. Through historical approach centred on documentary and bibliographical investigation, and by means of localizing, retrieving, assembling, selecting and ordering proceedings and reading of relevant literature, it was elaborated an instrument of research containing the bibliography of an about Francisco Vianna and those books textual configuration was analysed, that is to say, to focus on different constitutive aspects of their meanings. The conclusion is that in those books, a proposal to make concrete the analytical method for reading teaching is presented, which is related to other proposal concerning reading teaching and their... (Complete abstract click electronic access below)
79

Modélisation numérique du contact pour matériaux composites / Elastic contact modeling of woven composites

Leroux, Julien 04 July 2013 (has links)
Les aubes de turboréacteurs sont aujourd’hui sujets à de nouvelles technologiques novatrices : les matériaux composites tissées 3D. Ces modifications matériaux permettent des réductions de masse significatives, et conduisent à des performances énergétiques et environnementales accrues. Ces structures tissées possèdent généralement des architectures complexes et requièrent une bonne caractérisation mécanique. Des outils de modélisation textile et d’homogénéisation ont été développés, la géométrie et les propriétés physiques de l’architecture tissée y sont analysées. Toutefois, il est important de prévoir les endommagements engendrés dans ces matériaux au niveau des zones de contact soumises à du fretting. En effet, les pieds d’aubes de turboréacteurs font face à des sollicitations de type fretting. Il en résulte deux types d’endommagements : l’amorçage et propagation de fissures et l’usure des surfaces en contact. Quantifier ces endommagements requiert une analyse fine du contact à partir d’un outil de calcul à la fois robuste et rapide. Pour mener à bien cet objectif, un code semi-analytique permettant aujourd’hui de traiter des problèmes hétérogènes de contacts élasto-plastiques est développé. La méthode d’inclusion équivalente proposée au sens d’Eshelby est utilisée dans le solveur de contact pour décrire l’effet des hétérogénéités (cavités, inclusions, fibres ou torons). L’un des corps en contact peut contenir de multiples hétérogénéités de formes parallélépipédiques, ellipsoïdales, et ses formes dégénérées (ellipsoïde oblate, ellipsoïde prolate, sphère, cylindre, disque plat,...). Cette méthode est modifiée et améliorée afin de prendre en compte les influences mutuelles entre les inclusions hétérogènes voisines, et la décohésion à l’interface hétérogénéité/matrice. Un premier couplage avec un modèle de contact aube/disque Eléments Finis permet de prendre en compte les effets de structures. Cette méthode est analogue à un zoom structural lorsqu’un maillage fin est nécessaire dans des zones de contact à fort gradient de contraintes soumises à un endommagement de type fretting. Un second couplage avec le logiciel WiseTex permet de décrire la géométrie réelle du tissage du composite, les propriétés matériaux des fibres et de la matrice. Une segmentation fine du modèle permet de discrétiser les mèches en de multiples hétérogénéités ellipsoïdales équivalentes et d’appliquer la méthode d’inclusion équivalente modifiée. A partir de cette mise en donnée d’un matériau composite tissé revêtu, des calculs de contact tridimensionnel multiéchelle en situation de fretting sont réalisés avec succès. / New baseline turbofan engines feature advanced blade technology made of 3D woven composites for a significant reduction in weight and an increase in energy and environmental performance. Woven structures generally have complex architectures wich require high level of mechanical model. Modeling textile and homogenization tools have been developed to provide precisely the geometry and physical properties of the woven architecture. However, it is important to predict the damage mode under contact zone which are subjected to fretting. Indeed, the blade roots of turbofan engines are damaged by fretting phenomenon. Fretting modes generate two kinds of damage : (i) the initiation and propagation cracks, (ii) wear on contact surfaces. Quantify these two kinds of damage requires a detailed contact analysis from a robust and fast contact solver. In order to reach this goal, a semi-analytical solver allows to solve heterogeneous elasto-plastic contact problems. Equivalent inclusion method in the sense of Eshelby allows to describe accurately the effect of inhomogeneities (cavities, inclusions, fibers or strands). Only one of contact bodies contains multiple heterogeneous of cuboïdal and ellipsoidal shapes, and their degenerated forms (oblate spheroid, prolate ellipsoid, sphere, cylinder, flat disk,...). This method is modified and improved in order to take into account the mutual influence between neighboring heterogeneous inclusions and decohesion at the interface heterogeneity/matrix. A first coupling with a finite element model of blade/disk contact allows to take into account the effects of structure. This method is analogous to a structural zoom when structural fine mesh is necessary within areas of high contact stress gradient subjected to fretting. A second coupling with the software WiseTex allows to describe the geometry of the actual weaving of the composite, the material properties of the fibers and the matrix. A fine segmentation of the numerical model allows to discretize reinforcements to multiple equivalent ellipsoidal heterogeneities and to apply the modified equivalent inclusion method. Three-dimensional simulation of frictional contact model are successfully completed from these data of a coating woven composite.
80

Modélisation et simulation des procédés de mise en compression des surfaces à très grandes vitesses de déformation par méthode semi-analytique / Modeling and simulation of the processes of compressing of surfaces at high strain rate by using semi-analytical method

Taro, Mandikizinoyou 30 November 2015 (has links)
La défaillance des pièces mécaniques est très souvent initiée par un défaut de surface. Par conséquent, la génération de contraintes résiduelles compressives sur des pièces mécaniques via une déformation plastique hétérogène améliore la tenue en fatigue et augmente la durée de vie des pièces. Parmi les procédés permettant d'introduire des contraintes résiduelles dans les pièces, le traitement par choc laser est plus intéressant à plusieurs titres. D'une part, il permet de produire des pressions en surface du matériau de l'ordre de 1 à 6 GPa sur de courtes durées d'impulsion allant de 3 à 30 nanosecondes. D'autre part, il offre la possibilité d'introduire des contraintes résiduelles de compression sur une certaine profondeur tout en conservant l'état initial de la pièce traitée. Ainsi, les simulations numériques par réalisation de modèles simples permettent de cerner les physiques mises en jeux. Dans cette perspective, la méthode semi-analytique offre d'énormes avantages, notamment la simplicité des modèles et la réduction des temps de calcul. Cependant, cette méthode n’a jamais été étendue aux problème dynamiques. Dans cette thèse la méthode semi-analytique a été étendue aux problèmes dynamiques et le modèle mis en place été appliqué pour la simulation du procédé de choc Laser / The failure of the mechanical parts is very often initiated by a surface defects. Consequently, the generation of compressive residual stresses on mechanical parts by introducing a heterogeneous plastic strain improves the resistance to fatigue and increases the lifetime of the parts. Among the processes making it possible to introduce residual stresses into the parts, the laser shock peening is more interesting for several reasons. On the one hand, it makes it possible to produce pressures on the surface of material of about 1 to 6 going GPa over short pulse times from 3 to 30 nanoseconds. In addition, he gives the opportunity of introducing residual stresses of compression on a certain depth while preserving the initial state of the treated part. The numerical simulation becomes necessary to determine the best physical phenomena involved. Thus, the semi-analytical method offers a lot of advantages, in particular the simplicity of the models and the computation times saving. This method was never extended to the dynamic problems. In this thesis the semi-analytical method was extended to the dynamic problems and the model implemented is applied for the simulation of the Laser process of shock.

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