Tesis sobre el tema "Parasitic component"

A two-wire, low component count soil temperature sensor was developed. The sensor uses one wire for ground and the other wire is used for both power and communication. Pulse width modulation is used to send temperature measurements to the master, where the duty cycle is proportional to the temperature. The sensor parasitically powers itself from the bidirectional data line. In order to reduce the number of components necessary, a microcontroller with an internal temperature sensor is used. Finally, the sensor can receive data from the master on the bidirectional communication line, which is used for calibrating the sensor.

In this thesis, the design of passive networks with the aid of full-wave simulation software and geometry-based models of lumped elements is investigated. This is done by examining the results of a number of simulation examples, as well as measured data from manufactured designs to compare against simulated equivalents. One such example is a chip antenna evaluation board design, in which the PCB, antenna, matching components and connector are all modeled. When measured, the simulation agreed with the board’s best matched frequency of 5.5 GHz to within 20 MHz. In another, a new antenna layout is generated from an existing evaluation design which, produced a match of about -15 dB at the design frequency with a similar bandwidth to that shown on the antenna datasheet on the first attempt at manufacture. Additionally, a statistical experiment was conducted in order to provide insight into the phenomenon of coupling between lumped components, and to define clearly when it starts to become an important effect to consider. For both chip capacitors and inductors, a behavioral model of how much crosstalk is present in a prospective circuit was developed which takes into account angle and distance between components, as well as case size. Finally, a simple discrete gradient descent was implemented in a commercial full-wave simulation software in order to assist in the refinement of designs containing 3-D geometry-defined component models.

Les progrès technologiques réalisés en matière d'interrupteurs semiconducteurs de puissance, ont conduit au début des années 80, à l'apparition du transistor bipolaire à grille isolée, plus couramment désigné sous l'abréviation IGBT. Etant donnés les niveaux de puissance que ces composants sont aujourd'hui aptes à commuter, une protection contre les défauts devient nécessaire. Un fusible rapide associé au composant permet d'éviter l'explosion du boîtier en cas de court-circuit, et ainsi de garantir la sécurité des personnes et des divers composants à proximité. Une étude du comportement de l'IGBT en régime de court-circuit a été entreprise afin d'évaluer une valeur caractéristique de l'explosion, et de dimensionner précisément le calibre du fusible. L'intégration d'un fusible dans un convertisseur à IGBT passe en premier lieu par l'étude des perturbations générées par le convertisseur sur le fusible. Ces perturbations, associées aux effets de proximité, se traduisent par une répartition déséquilibrée des courants entre des fusibles en parallèle ou même entre les éléments fusibles. Ainsi, nous nous sommes attachés à élaborer un modèle électrothermique du fusible permettant de calculer la répartition des courants et la température des éléments fusibles. Ce modèle permet de définir des abaques, en liaison avec un critère thermique de bon fonctionnement des fusibles. En second lieu, nous avons analysé les perturbations engendrées par le fusible sur le convertisseur. Celles-ci se traduisent principalement par l'introduction d'une inductance supplémentaire dans le circuit, laquelle pouvant être néfaste au fonctionnement du convertisseur. Nous avons proposé quelques règles de conception permettant de réduire l'inductance rajoutée
Technology advancement in power semiconductor devices has led to the achievement of the insulated gate bipolar transistor (IGBT). Considering the power switched by these components, protection against fauIts is necessary. A fast fuse in series with the device can prevent the explosion of the case if a short circuit occurs, and consequently ensures people and equipment safety. An investigation on the short circuit behaviour ofIGBT has been carried out to select the ideal fuse rating. KEYWORDS Disturbances created by converters on the fuse have to be taken into account when integrating the fuse in the converter. These disturbances can be attributed to proximity effects, a consequence of which is an unbalance between fuses in parallel or even between fuse elements inside a fuselink. Consequently, an electrothermal model of the fuse is elaborated for the calculation of the distribution of current and temperature of fuse elements. This model helps us to obtain abacus associated to a thermal criterion ensuring the good working conditions of fuses. Perturbation created by the fuse on the converter is mainly characterised by an inductance added in the circuit. This inductance can be harmful to the working of the converter. Sorne rules of conception are proposed to reduce this supplementary inductance

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Diversas características ecológicas do hospedeiro e a sua distribuição geográfica são fatores que influenciam na composição e estrutura das comunidades de parasitas. O inventário da diversidade parasitária é considerado de grande importância para o conhecimento da relação parasita-hospedeiro e também da conservação e preservação de ecossistemas. No entanto, poucos estudos sobre comunidade de parasitas associadas a comunidades de hospedeiros tem sido realizados. Assim, os objetivos deste estudo foram: descrever e caracterizar a composição e estrutura das comunidades componentes de helmintos associados aos anuros hospedeiros do Peru; avaliar a riqueza e diversidade das comunidades componentes de helmintos para a comunidade de hospedeiros para cada área estudada; avaliar a similaridade das comunidades componentes de parasitas entre os ambientes estudados; avaliar a influência dos fatores bióticos dos hospedeiros sobre a fauna parasitária; e em que extensão as estratégias de vida dos hospedeiros podem influenciar esta especificidade. Um total de 279 espécimes de 12 espécies de anuros foi analisado quanto a presença de parasitas: Allobates ornatus, Rhinella marina, Rhinella spinulosa, Ameerega trivittata, Dendropsophus rhodopeplus, Hypsiboas lanciformis, Hypsiboas punctatus, Scinax garbei, Adenomera andreae, Leptodactylus discodactylus, Leptodactylus pentadactylus e Leptodactylus wagneri. Foram registrados 36 taxa de helmintos: 23 nematoides, 7 trematódeos, 3 acantocéfalos, 2 cestoides e 1 monogenético. Rhinella marina apresentou a maior abundância média (184,3 ± 670,9) e a maior riqueza (S = 19). Rhinella marina de Tarapoto, apresentou riqueza e diversidade parasitária similares entre as áreas antropizada e preservada (p > 0,05), porém algumas espécies de parasitas apresentaram diferenças nos valores de prevalência, abundância e importância relativa entre as duas infracomunidades. Assim, a composição e estrutura da comunidade de helmintos de Tarapoto pode esta sofrendo influência das características dos habitats nesta espécie de anuro. Está influência também é observada quando comparamos as comunidades de helmintos das quatro localidades do Peru: Huanuco, Iquitos, Tarapoto e Tingo Maria. O acantocéfalo, Pseudoacanthocephalus lutzi,foi encontrado com alta prevalência parasitária em R. marina de Huanuco. No entanto, o tamanho do hospedeiro e do parasita não tiveram correlação significativa com a abundância parasitária (p > 0,05), então, a comunidade deste acantocéfalo em Huanuco não esta sofrendo influência das características do hospedeiro. Este estudo também registrou vários novos registros de hospedeiros e localidade para espécies de helmintos, contribuindo para o conhecimento da fauna de parasitas de anfíbios na região Neotropical.
Several ecological characteristics of the host and its geographical distribution are factors that influence the composition and structure of the parasite communities. The inventory of parasite diversity is considered of great importance for the knowledge of the parasite-host relationship and also for the conservation and preservation of ecosystems. However, few studies on parasite community associated with host communities have been conducted. Thus, the objectives of this study were: to describe and to characterize the composition and structure of the helminth component communities associated with the anurans of Peru; to evaluate the richness and diversity of the helminth component communities for the host community for each studied area; to evaluate the similarity of the parasite component communities among the studied environments; to evaluate the influence of host biotic factors on parasitic fauna; and to what extent host life strategies can influence the specificity. A total of 279 specimens of 12 species of anurans was analyzed for the presence of parasites: Allobates ornatus, Rhinella marina, Rhinella spinulosa, Ameerega trivittata, Dendropsophus rhodopeplus, Hypsiboas lanciformis, Hypsiboas punctatus, Scinax garbei, Adenomera andreae, Leptodactylus discodactylus, Leptodactylus pentadactylus, and Leptodactylus wagneri. Thirty-six helminth taxa were recorded, as follow: 23 nematodes, seven trematodes, three acanthocephals, two cestodes, and one monogenean. Rhinella marina showed the highest mean abundance (184.3 ± 670.9) and the highest richness (S = 19). Rhinella marina of Tarapoto, presented parasitic richness and diversity similar between anthropic and preserved areas (p > 0.05), but some parasite species showed differences in prevalence, abundance, and relative importance between the two infracommunities. Thus, the composition and structure of the helminth community of Tarapoto may be influenced by the characteristics of the habitats in this anuran species. This influence is also observed when we compare the helminth communities of the four locations of Peru: Huanuco, Iquitos, Tarapoto, and Tingo Maria. The acanthocephalus, Pseudoacanthocephalus lutzi, was found with high parasitic prevalence in R. marina of Huanuco. However, host and parasite size did not correlate significantly with abundance of parasites (p > 0,05), then, the community this acanthocephalan in Huanuco is not influenced by characteristics of the host. This study also recorded several new host and local records for species of helminths, contributing to the knowledge of the fauna of amphibian parasites in the Neotropical region.
CNPq: 140301/2013-5

Orientador: Reinaldo José da Silva
Resumo: Diversas características ecológicas do hospedeiro e a sua distribuição geográfica são fatores que influenciam na composição e estrutura das comunidades de parasitas. O inventário da diversidade parasitária é considerado de grande importância para o conhecimento da relação parasita-hospedeiro e também da conservação e preservação de ecossistemas. No entanto, poucos estudos sobre comunidade de parasitas associadas a comunidades de hospedeiros tem sido realizados. Assim, os objetivos deste estudo foram: descrever e caracterizar a composição e estrutura das comunidades componentes de helmintos associados aos anuros hospedeiros do Peru; avaliar a riqueza e diversidade das comunidades componentes de helmintos para a comunidade de hospedeiros para cada área estudada; avaliar a similaridade das comunidades componentes de parasitas entre os ambientes estudados; avaliar a influência dos fatores bióticos dos hospedeiros sobre a fauna parasitária; e em que extensão as estratégias de vida dos hospedeiros podem influenciar esta especificidade. Um total de 279 espécimes de 12 espécies de anuros foi analisado quanto a presença de parasitas: Allobates ornatus, Rhinella marina, Rhinella spinulosa, Ameerega trivittata, Dendropsophus rhodopeplus, Hypsiboas lanciformis, Hypsiboas punctatus, Scinax garbei, Adenomera andreae, Leptodactylus discodactylus, Leptodactylus pentadactylus e Leptodactylus wagneri. Foram registrados 36 taxa de helmintos: 23 nematoides, 7 trematódeos, 3 acan... (Resumo completo, clicar acesso eletrônico abaixo)
Doutor

Among the predicted impacts associated with global climate change, warming is of special interest because the rates of physiological processes are temperature-dependent. Insects and other ectotherms are likely to be affected due to their limited ability to control body temperature. In this study, I measured the tolerance to extreme high temperatures, i.e., critical thermal maximum (CTmax), of component species in a tri-trophic system, including an herbivore (Manduca sexta), a primary larval parasitoid (Cotesia congregata) and a hyperparasitoid (genus Silochalcis). For wild insects, the parasitoid had the lowest CTmax, the hyperparasitoid had the highest, and the herbivore was intermediate. For laboratory insects, the parasitoid had a lower CTmax than the herbivore. Results suggest that laboratory colonies can be used to predict relative thermal performance of interacting species in the field. Variations in tolerance to high temperature among component species could disrupt the outcome of interactions in multi-trophic systems.

Les composants magnétiques en technologie planar répondent aux exigences actuelles de l'Electronique de Puissance (EP), à savoir la montée en fréquence de commutation des structures d'EP et la réduction du volume des convertisseurs. La première tendance impose des contraintes fortes en termes de compatibilité électromagnétique (CEM) des équipements. Ces dernières doivent être prises en compte par les ingénieurs dès la phase conception des convertisseurs en se basant sur des modèles fiables, peu développés pour les composants planar dans la littérature scientifique. Ce travail de thèse porte ainsi sur la modélisation des composants planar pour applications aux filtres CEM. Différentes méthodes sont développées au cours de cette thèse pour arriver à évaluer de manière fine les éléments parasites des inductances planar de mode commun : capacités parasites et inductances de fuite. Une partie du travail a porté sur la modélisation par circuits équivalents du comportement fréquentiel des inductances de MC. Une approche automatisée, basée sur un algorithme de fitting a ainsi été développée pour élaborer des circuits équivalents fiables et robustes. Des approches analytiques (Décomposition du Champ Electrique) et semi-analytiques (Fonctions de Green) ont aussi été proposées pour évaluer les valeurs des éléments parasites. La dernière partie de la thèse est plus orientée conception, avec la réalisation de deux structures de composants innovantes, la première se basant sur une technique de compensation des capacités parasites à l'aide d'éléments parasites structuraux et la seconde sur l'association de deux noyaux magnétiques, possédant matériaux et géométries différentes

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Pontoporia blainvillei is a cetacean popularly know in Brasil as toninha. Its distribution is restrict for estuarine and coastal waters of south-west of Atlantic. Studies of gastrintestinalparasitology of toninhas indicate a component community formed for less species, including nematodes, trematodes and acantocephalans. However, despite knowing that the course of infection is the ingestion of infected prey, intermediate hosts are unknown. The toninhas s diet is composed mainly for fishes, squids and shrimps. Many of these fishes in various areas of distribution of the cetacean have been reported with parasites that attack the species in some stage of development. However, larval forms of the trematode Synthesium pontoporiae and the acantocephalan Bolbosoma turbinella were not identified in any of the food items of P. blainvillei. The present study aimed to evaluate three components of the diet of P. blainvillei as possible sources transmission of parasitiasis. Fifty specimens of Doryteuthis sanpaulensis; forty-three specimens of Paralonchurus brasiliensis and fifty specimens of Trachurus lathami were necropsied. The organs were individually, washed in tamis (150μm) and examined under a stereomicroscope. Helminths were collected, counted, fixed in AFA, stained with Delafield s hematoxylin or Gomori s trichrome, clarified in Amman s lactophenol or Beech creosote and mounted on slides. Parasitological indices were calculated. None of the food items analyzed showed infection by metacercariae of S. pontoporiae. Helminths found in D. sanpaulensis did not have records of infection of P. blainvillei. Cistacanths of C. australe were found in the coelomic cavity and mesentery of P. brasiliensis (P=53,49%; IMI=6,74) and of T. lathami (P=4%; IMI=1,50). Cistacanths of B. turbinella were on same sites of T. lathami (P=14%; IMI=2,14). Paralonchurus brasiliensis and T. lathami are recorded in this study as new paratenics hosts for C. australe, as well as T. lathami is to B. turbinella. In addition to the parasites that infect P. blainvillei, the nematodes Hysterothylacium sp., Dichelyne (D.) spinicaudatus and Procamallanus pereirai, and trematodes Diphterostomum brusinae, Opecoeloides catarinensis, O. stenosomae, Pachycreadium gastrocotylum, Aponurus laguncula, A. pyriformis and Lecithochirum sp. are registered as members of the component community of P. brasiliensis and five new records of parasitism on fish and a new record of parasite species to brazilian waters. The use of nematodes as biomarkers for distinguishing the populations of P. brasiliensis is discussed. Through the present study more about the ecology and parasitology of final and paratenic hosts were revealed, as well as aspects of the biology of parasites, contributing to the knowledge about the marine biology of the south Atlantic.
Pontoporia blainvillei é um cetáceo conhecido popularmente no Brasil como toninha, cuja distribuição é restrita às águas estuarinas e costeiras do sudoeste do Atlântico. Estudos sobre parasitologia gastrintestinalde toninhas indicam uma comunidade componente formada por poucas espécies, incluindo nematódeos, trematódeos e acantocéfalos. Entretanto, apesar de se saber que a forma de infecção é a ingestão de presas infectadas, os hospedeiros intermediários são pouco conhecidos. A dieta da toninha é composta principalmente por peixes, lulas e camarões. Muitos desses peixes em várias áreas da distribuição do cetáceo já foram reportados com parasitos que acometem a espécie em algum estágio de desenvolvimento. Contudo, formas larvais do trematódeo Synthesium pontoporiae e do acantocéfalo Bolbosoma turbinella não foram identificadas em nenhum dos itens alimentares de P. blainvillei. O presente estudo teve como objetivo avaliar três espécies componentes da dieta de P. blainvillei como possíveis fontes transmissoras de parasitíases. Cinquenta espécimes de Doryteuthis sanpaulensis; quarenta e três espécimes de Paralonchurus brasiliensis e cinquenta espécimes de Trachurus lathami foram necropsiados. Os órgãos foram individualizados, lavados em tamis (150μm) e examinados sob estereomicroscópio. Os helmintos coletados foram contados, fixados em AFA, corados com hematoxilina de Delafield ou tricrômico de Gomori, clarificados em lactofenol de Amman ou creosoto de Faia e montados em lâminas. Índices parasitológicos foram calculados. Nenhum dos itens alimentares analisados apresentou infecção por metacercárias de S. pontoporiae. Helmintos encontrados em D. sanpaulensis não têm registros de infecção em P. blainvillei. Acantocistos de C. australe foram encontrados na cavidade celômica e mesentério de P. brasiliensis (P=53,49%; IMI=6,74) e de T. lathami (P=4%; IMI=1,50). Acantocistos de B. turbinella estiveram nos mesmos sítios de T. lathami (P=14%; IMI=2,14). Paralonchurus brasiliensis e T. lathami são registrados no presente estudo como novos hospedeiros paratênicos para C. australe, assim como T. lathami é para B. turbinella. Além dos parasitos que infectam P. blainvillei, os nematódeos Hysterothylacium sp., Dichelyne (D.) spinicaudatus e Procamallanus (S.) pereirai, e os trematódeos Diphterostomum brusinae, Opecoeloides catarinensis, O. stenosomae, Pachycreadium gastrocotylum, Aponurus laguncula, A. pyriformis e Lecithochirum sp. são registrados como membros da comunidade componente de P. brasiliensis sendo cinco novos registros de parasitismo para o peixe e um novo registro de espécie parasita para águas brasileiras. A utilização de nematódeos como biomarcadores para a distinção de populações de P. brasiliensis é abordada. Através do presente estudo mais informações sobre a ecologia e parasitologia dos hospedeiros definitivo e paratênicos foram reveladas, assim como aspectos da biologia dos parasitos, contribuindo para o conhecimento sobre a biologia marinha do Atlântico sul.

Na área de Ensaios Não Destrutivos, o ensaio por eddy current (correntes parasitas) é uma técnica eletromagnética largamente utilizada nas indústrias aeroespacial, nuclear e petroquímica. Esse ensaio detecta descontinuidades superficiais e subsuperficiais, prevenindo acidentes. A técnica phased array surgiu para suprir carências, como o enorme tempo gasto para execução do ensaio em materiais de geometria complexa e falta de registro do ensaio. Essa técnica, já bastante utilizada em outros países, ainda é pouco utilizada no Brasil, por não haver estudos que comprovem a viabilidade econômica, os níveis de detectabilidade de descontinuidades e a confiabilidade dos resultados. Este trabalho tem como objetivo comparar as técnicas do ensaio por Correntes Parasitas convencional com a técnica por phased array, em materiais e peças especificamente utilizados no setor aeronáutico e espacial. Foram selecionadas amostras de materiais e peças, para que pudessem ser aplicadas ambas as técnicas e comparados os resultados. Foi realizado um levantamento bibliográfico das principais normas e especificações utilizadas neste segmento, para verificar a compatibilidade dos métodos. Para atender ao objetivo deste trabalho, foram realizados sete experimentos, variando o material e as técnicas. Após a realização dos ensaios, observou-se uma grande redução de tempo na execução do ensaio, com consequente redução de custos e maior detectabilidade das descontinuidades, com o uso da técnica por phased array. Portanto, baseado nos resultados encontrados, pode-se afirmar que a técnica por phased array pode ser utilizada neste segmento, com vantagens sobre a técnica convencional.
In the area of nondestructive testing, eddy current testing is an electromagnetic technique widely used in aerospace, nuclear and petrochemical industries. This test detects surface and subsurface discontinuities, preventing accidents. Phased array technique has emerged to fill in the gaps, as the enormous time spent implementing the test of large parts or complex geometry and lack of trial registration. This technique, already widely used in others countries, is not used in Brazil, there is no studies proving the economic viability, levels of detectability of discontinuities and reliability of the results. This study aims to compare the conventional technique by eddy current testing with phased array technique, in particular materials and parts used in aeronautics and space sector. Samples of materials and parts were prepared, so that could be applied both techniques and compared the results. A literature survey of the main standards and specifications for this segment was conducted to verify the compatibility of the methods. To meet the objective of this work, seven experiments were performed, varying the material and techniques. After the tests, there was a significant time reduction with the use of phased array technique, costs reduction and increased detectability of discontinuities. Based on the results, it can be said that phased array technique can be used in this segment, with advantages over the conventional technique.

La minimalisation architecturale des dispositifs entraine une augmentation du champ electrique dans les transistors, qui est a l'origine de la generation de porteurs chauds reduisant la fiabilite des composants. L'objectif de cette these est d'analyser les phenomenes et les mecanismes physiques des effets de porteurs chauds relatifs aux transistors mos silicium sur isolant (soi) ultracourts. La structure et le fonctionnement des transistors mos/soi sont d'abord decrits en detail. Puis, differentes technologies pour la realisation du materiau soi et l'interet de tels composants sont rappeles. Le deuxieme chapitre presente une analyse des effets de porteurs chauds dans les composants soi fortement submicroniques. Ces resultats etudies par differentes methodes et dans une large gamme de polarisation permettent d'indiquer avec precision le pire cas de degradation et souligner l'importance de l'action du transistor bipolaire parasite (tbp). Afin de determiner precisement la tension d'alimentation maximale, une technique d'extrapolation de la duree de vie des dispositifs tenant compte de la degradation en deux etapes est proposee dans le chapitre iii. Le quatrieme chapitre est consacre a l'etude de la degradation induite par l'action du tbp a l'etat off, l'influence de cet effet indesirable sur le vieillissement des composants etant identifiee. Le but du dernier chapitre est de comparer de maniere approfondie la fiabilite des nmos/soi et pmos/soi avec differentes epaisseurs du film de silicium et fabriques sur divers materiaux soi (simox et unibond). Enfin, d'autre aspects tels que les effets de porteurs chauds a basse temperature ont egalement ete etudies au cours de ce travail.

Este trabalho apresenta o estudo de um sistema genérico de medição que utiliza o princípio das correntes de Foucault, comumente conhecidas como correntes parasitas. O modelo do sistema é representado como um circuito elétrico equivalente composto por R1 e L1, respectivamente caracterizando a resistência e a indutância do circuito primário, as quais são conhecidas por uma bobina de excitação. Já no secundário, R2 e L2, estão representando a perda ôhmica e a indutância da amostra no qual as correntes parasitas são induzidas, além de outros dois componentes, M indutância mútua dos indutores acoplados e k, coeficiente relacionado ao acoplamento magnético entre os circuitos primário e secundário. A análise tradicionalmente utilizada para este tipo de medição é a avaliação da reflexão da impedância equivalente do circuito secundário representando a amostra no circuito primário. O trabalho analisa as equações de malha do circuito equivalente no domínio da frequência e identifica os parâmetros do modelo. A partir da identificação do sistema realizada com os ensaios experimentais, foi possível descobrir a constante de tempo indutiva τL do sistema. A partir dessa constante, observou-se a variação acentuada da mesma em relação a variação da impedância equivalente. Ainda é apresentada uma estimativa dos valores de R2 e L2 realizada por meio da unificação das informações obtidas com a identificação, aliada com as informações de campo magnético obtidas a partir de um sensor do tipo GMR e pela simulação em um software de elementos finitos COMSOL Multiphysics.
This work presents the study of a generic measurement system that uses the prin- ciple of eddy currents. The system model is represented as an equivalent electric circuit composed of R1 and L1 respectively characterizing the resistance and induc- tance of primary circuit, which are known by an excitation coil. In the secondary, R2 and L2 are representing the ohmic loss and the inductance of the sample in which the eddy currents are induced, in addition two other components, the mutual induc- tance of the coupled inductors and k, coefficient related to the magnetic coupling between the primary and secondary circuits. The analysis traditionally used for this type of measurement is the reflection evaluation of the equivalent impedance of the secondary circuit representing the sample in the primary circuit. The work analyzes the mesh equations of the equivalent circuit in the frequency domain and identifies the parameters of the model. From the identification of the system performed with the experimental tests, it was possible to discover the inductive time constant τL of the system. From this constant, it was observed the sharp variation of the same in relation to the variation of equivalent impedance. An estimate values, R2 and L2 performed by unification of the information obtained with the identification, to- gether with the magnetic field information obtained from a GMR type sensor and by simulation in a finite element software COMSOL Multiphysics.

Dans les applications, on rencontre fréquemment des structures minces de géométrie complexe qui nécessitent l'utilisation de maillages surfaciques comportant des éléments triangulaires. Il faut donc trouver des éléments finis triangulaires de coque qui soient robustes vis-à-vis du verrouillage numérique, mais aussi au défaut de consistance. Nous avons formulé un test numérique qui permet de détecter le verrouillage membranaire, et également l'existence de modes parasites de membrane. L'élément MITC6a (Bathe et Lee) apparaît comme le meilleur élément à six noeuds, mais il exhibe des modes parasites de membrane qui peuvent considérablement détériorer la solution numérique. Nous proposons une technique de filtrage qui consiste à ajouter un terme de stabilisation de cisaillement non réduit et nous avons défini l'élément MITC6rs avec une interpolation plus riche pour le cisaillement. Après une évaluation numérique détaillée, nous recommandons l'usage de l'élément MITC6a stabilisé.

Trypanosoma brucei, un parasite flagellé unicellulaire, est responsable de la trypanosomiase humaine africaine aussi connue comme la maladie du sommeil.Les microtubules (MTs) sous-pelliculaires, le quartet de MTs (MTQ), le flagelle (F) et le collier de la poche flagellaire (CPF) sont les principaux composants du cytosquelette dutrypanosome. À ce jour, une seule protéine du CPF, BILBO1, a été identifiée et caractérisée.Dans cette étude, nous montrons in vivo que BILBO1 forme des polymères capables deconstruire un échafaudage qui permet l’ancrage de protéines partenaires. Ainsi, un crible en double hybride chez la levure a identifié plusieurs protéines partenaires de BILBO1,notamment une nouvelle protéine appelée FPC4. Nous démontrons que FPC4 est une protéine spécifique des kinétoplastides, localisée au CPF mais aussi au hook-complex, une structure proche du CPF. L’interaction FPC4 – BILBO1 est démontrée in vitro et in vivo, etles domaines d'interaction identifiés. En outre, nous démontrons in vivo et in vitro que FPC4est une protéine associée aux microtubules. Nos données suggèrent fortement que FPC4est impliquée dans le processus de séparation des CPFs au cours du cycle cellulaire. Nos résultats mettent en évidence un lien étroit entre le MtQ et le CPF et l'implication probable duhook-complex. Enfin, nous mettons en évidence une structure analogue au hook-complex chez les Leishmanies. L’interaction BILBO1 – FPC4 représente une nouvelle cible thérapeutique et sera caractérisée plus avant
Trypanosoma brucei, a unicellular flagellated parasite, is responsible for the human African trypanosomiasis also known as sleeping sickness. Sub-pellicular microtubules (MT), the MT quartet (MtQ), the flagellum (F) and the Flagellar Pocket Collar (FPC) are the main components of the T. brucei cytoskeleton. To date, only a single FPC protein, BILBO1, has been identified and characterized. In this study we demonstrate in vivo that BILBO1 forms polymers able to build a scaffold structure that anchors partner proteins. As such, a yeast-2-hybrid screen identified several BILBO1 interacting protein partners. We demonstrate that FPC4 is a kinetoplastid-specific protein, which is localized at the FPC and at the hook complex. Its specific interaction with BILBO1 has been demonstrated in vitro and in vivo, and the interacting domains identified. Furthermore, we demonstrate that FPC4 is a microtubule binding protein. Our data strongly suggest that FPC4 is involved in the separation of the old and the newly formed FPC during the cell cycle. Altogether, our results demonstrate a tight connection and interplay between the MtQ and the FPC and the likely involvement of an adjacent third structure, the hook complex. Finally, we highlight a structure similar to the hook-complex in Leishmania. The BILBO1 – FPC4 interaction represents a new therapeutic target and will be characterized further

The following studies were done to identify factors that influence the virulence of Xenorhabdus nematophilus and the interactions of the bacterium with the nonself defence systems of nonimmune Galleria mellonella. Isolates of X. nematophilus that are qualitatively similar in biochemical properties differed significantly in virulence for G. mellonella larvae. The production of enzymes such as proteases could not account for differences in the virulence of the isolates.
Growth conditions, influenced the growth rate and the interactions of the bacterium with nonimmune G. mellonella larvae. In general, X. nematophilus cells grown under aerobic conditions were more susceptible to the nonself defences of G. mellonella larvae than those grown under less than ideal conditions, resulting in increased clearance of the bacteria from the hemolymph (blood) of the insects. Clearance of the bacteria from the hemolymph of the insect was positively correlated with culture condition, culture age, and attachment to insect hemocytes in vitro.
Isolates of X. nematophilus produced flagella and fimbriae when grown under microaerobic and aerobic conditions. The type of fimbriae produced was influenced by culture conditions. The injection of both flagella and fimbriae in picogram quantities into nonimmune G. mellonella caused an increase in total hemocyte counts within these insect larvae. The injection of fimbrial and flagellar antigens into G. mellonella larvae caused changes in the hemocyte types found in circulation in the insect's hemolymph. (Abstract shortened by UMI.)

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This study verified helminth parasites infection in gastrointestinal tract, lungs, heart, and kidneys of southern sea lions, Otaria flavescens, from south coast of Rio Grande do Sul State, Brazil. Twenty-nine sea-lions were found dead on the beaches, whose carcasses had mild state of decomposition, were necropsied. The organs were collected during field necropsies for laboratory analyses were 24 small and large intestines, 24 livers including parenchyma and gall bladder, 29 stomachs, 24 hearts, and 24 pairs of kidneys. The organs were maintained frozen at -20°C until their processing. A sieve with 150µm mesh was used for screening the parasites. All content retained was analyzed under stereomicroscope. The helminthes were collected, counted, fixed in AFA, stained with carmine, and clarified in beechwood creosote. The small intestines were divided into three segments that were separately analyzed to record the distribution of helminthes by preference sites. Kolmorogov-Smirnov test was used to verify the type of data distribution. Comparison of mean abundance of infection between age classes was performed through Wilcoxon test at significant level of 0.05. Correlations between infection intensity, sex, total length of the individual, and length of small and large intestines were determined using Pearson s Correlation. Action® software version 1.1 was applied for statistical analyses. Among 29 specimens of O. flavescens 23 were males, three females, and three individuals whose sex could not be determined. The average length of the animals was 2.14±0.31m (1.58 to 2.64m) including 13 sub-adults and 16 adults. A total of 996 specimens of Contracaecum ogmorhini were recorded, especially in the stomach (10.34% of prevalence), 42,145 specimens of Corynosoma australe (100% of prevalence) and 512 of Bolbosoma turbinella (50% of prevalence) were found. Two species of trematodes were found: Stephanophrora uruguayense (Prev. 4.17%) and Ascocotyle (Phagicola) longa (Prev. 33.33% ), a estimated total of 1,988.202 specimens. Cestodes were found in only one of the hosts (4.16% of prevalence) which presented four scoleces. Macroscopically, liver, gall bladder, heart, lungs, and kidneys did not contain parasites. No significant correlation was observed between infection intensity, mean abundance, sex, total length of the host, or length of intestines. Infections levels were similar between sub-adults and adults sea lions. This is the first record of Diphyllobothrium sp., Bolbosoma turbinella, Contracaecum ogmorhini, Ascocotyle (Phagicola) longa, and Stephanoprora uruguayense in O. flavescens in Brazilian waters. As regards parasite fauna of O. flavescens, our data are different from those previously reported for specimens from Pacific coast of South America.
Este estudo analisou os helmintos parasitos gastrointestinais, pulmonares, cardíacos e renais do O. flavescens no litoral sul do Rio Grande do Sul, Brasil. Foram necropsiados 29 leões-marinhos, cujas carcaças apresentavam baixo estado de decomposição. Os órgãos coletados mediante necropsia a campo para análise em laboratório foram 24 intestinos delgado e grosso, 24 fígados incluindo parênquima e vesícula biliar e 29 estômagos, 24 corações e 24 pares de rins. Os órgãos foram congelados a 20oC até o seu processamento. Para a triagem dos parasitos foi usada peneira com malha de 150 µm e todo o conteúdo retido foi analisado sob microscópio estereoscópico. Os helmintos foram fixados em AFA, corados com Carmin e clarificados com creosoto de Faia. Os intestinos delgados foram divididos em três segmentos que foram analisados separadamente para registrar a distribuição dos helmintos por sítios de preferência. Teste de Kolmorogov-Smirnov foi utilizado para verificar tipo de distribuição dos dados. A comparação da abundância média de infecção entre classes etárias foi realizada através do teste de Teste de Wilcoxon usando nível de significância de 0.05. As correlações entre intensidade de infecção, sexo, comprimento total do individuo e comprimento dos intestinos delgado e grosso foram verificadas usando a Correlação de Pearson. Para as análises estatísticas usou-se o software Action® versão 1.1. De 29 espécimes de O. flavescens 23 eram machos, três fêmeas e em três indivíduos o sexo não pode ser determinado. A média do comprimento total dos animais foi 2,14±0,31m (1,58 - 2,64m), sendo 13 subadultos e 16 adultos. Foram registrados 996 espécimes de Contracaecum ogmorhini presentes principalmente no estômago, (prevalência 10%). Registrou-se 42.145 espécimes de Corynosoma australe (Prev. 100%) e 512 de Bolbosoma turbinella (Prev. 50%). Duas espécies de trematódeos foram coletados: Stephanophrora uruguayense (Prev. 4.17% ) e Ascocotyle (Phagicola) longa (Prev. 33.33% ) totalizando 1.988.202 espécimes. Cestódeos foram encontrados em apenas um hospedeiro (Prev. 4,16%) que apresentou 4 escóleces. Macroscopicamente, fígado, vesícula biliar, coração, pulmões e rins examinados não estavam parasitados. Nenhuma correlação significativa foi observada entre a intensidade de infecção, sexo, comprimento total ou comprimento dos intestinos. Este é primeiro registro de Diphyllobothrium sp., Bolbosoma turbinella e Contracaecum ogmorhini em O. flavescens em águas brasileiras. No que se diz respeito à fauna parasitária de O. flavescens, as espécies encontradas no presente estudo não são as mesmas previamente citadas para leãomarinho-do-sul da costa pacífica da América do Sul.

Investigou-se a existência de relação entre células normais de triatomíneos, formas evolutivas do T.cruzi e hospedeiros mamíferos. Hemócitos do vetor de espécies hematófagas não infectadas (Triatoma infestans, T. palidipennis, Dipetalogaster maximus, Rhodnius prolixus e Panstrongylus megistus) foram reconhecidos por soros de pacientes e camundongos infectados com Trypanosoma cruzi, por meio da técnica de imunofluorescência, enquanto que os hemócitos de um inseto fitófago, Diactor billineatus (ninfas e adultos) não foram reconhecidos pelos mesmos soros. Uma parcial reação cruzada foi observada entre hemócitos de T. infestans e soros de portadores de leishmaniose , o que não ocorreu com as amostras de portadores de doenças autoimunes, infecção com HIV e indivíduos normais. O tratamento de hemócitos com metaperiodato de sódio aboliu a fluorescência, mostrando que antígenos carboidratos estão envolvidos. O uso de lectinas marcadas revelou que N acetil-d-glicosamina, manose, glicose e βgal fazem parte da estrutura celular. O immunoblotting com extrato de hemócitos foi realizado com soros de pacientes chagásicos crônicos antes e depois do tratamento específico. Estes soros de ambos casos foram absorvidos com tripomastigotas e epimastigotas. Um número considerável de bandas desapareceu nos soros tratados com tripomastigotas, mas não com epimastigotas. Proteínas de 61-70, 41-50, 31-40 e 21-30 kDa foram as envolvidas no processo de absorção. Após a quimioterapia, as bandas de 121-130, 91-100, 81-90 e 61-60 kDa desapareceram nos soros não absorvidos. Um grupo de camundongos fêmeas A/Sn foi imunizado com hemolinfa livre de hemócitos (HL) e outro grupo com hemócitos (Hc) e desafiados com 5x102 tripomastigotas sangüícolas.(cepa Y). Picos de parasitemia dos camundongos HL e Hc foram observados um ou dois dias após o grupo controle. Apesar da parasitemia de ambos os grupos ter sido baixa, o grupo HL apresentou 43% de mortalidade, enquanto que o grupo Hc mostrou apenas 14 % de mortalidade. As citocinas IFNγ e TNFα estão envolvidas no processo de proteção,\' assim como óxido nítrico e anticorpos líticos. Os hemócitos induziram uma redução de IL-10, inibindo a resposta Th2. Desde que os hemócitos e tripomastigotas compartilham epítopos comuns, epítopos de hemócitos devem ser melhor estudados em virtude de seu potencial uso no imunodiagnóstico, imunoproteção e avaliação terapêutica.
Immunological relationship between normal triatomine cells, developmental life-cycle stages of T. cruzi and infected mammal hosts was investigated. Hemocytes from uninfected hematophagous vector species of triatomines (Triatoma infestans, T. palidipennis, Dipetalogaster maximus, Rhodnius prolixus and Panstrongylus megistus) were recognized by sera from patients and mice infected with Trypanosoma cruzi, by means of immunofluorescence assay (IFA), whereas hemocytes from a phytophagous bug, Diactor billineatus (nymphs and adults) were not recognized by the same sera. Hemocytes from T. infestans were partially recognized by leishmaniasis sera, but, not by samples from patients with autoimmune diseases, HIV positive sera. The treatment of hemocytes with sodium metaperiodate practically abolished the fluorescence staining, indicating the presence of carbohydrate antigens. These antigens were revealed be comprised of N acetyl-D-glucosamine, mannose and glucose and βgal, by means of fluorescent labelled lectins. Sera from chronic chagasic patients before and after the chemotherapy were reactive with hemocytes of P. megistus on immunoblotting, and the same sera previously absorbed with formaldehyde fixed cultured epimastigotes as well trypomastigotes. On immunoblotting a substantial number of bands diminished with sera absortion with trypomastigotes, but not with epimastigotes. Proteins of 61-70, 41-50, 31-40 and 21-30 kDa were the major proteins involved in the process of serum absorptions. After chemotherapy, protein bands of 121-130, 91-100, 81-90 and 51-60 kDa disappeared in unabsorbed sera. A group of female A/Sn mice were immunized with hemolymph free of hemocytes (MHL) and other group with hemocytes (MHC). Animais were challenged with 5x102 bloodstream trypomastigotes (Y strain). Parasitemia peaks of MHL and MHC groups were observed one or two days after the control group. In spite of the parasitemia for both groups was about 63% lower than the control group, the mortality for the MHL was 43%, differing from the MHC, which was 14% only. The Cytokines, IFNγ and TNFα, were shown to be involved in the protection of immunized mice, and also the nitric oxide and complement dependent lytic antibodies. Hemocytes showed to play a role in the reduction of the IL-10 production, inhibiting Th2 response. Thus, hemocytes and trypomastigotes share common epitopes, and these epitopes are potentially useful for immunodiagnosis, immunopratection, and evaluation of chemotherapic efficiency in Chagas\' disease control.

L'augmentation du niveau technologique des convertisseurs statiques d'Electronique de Puissance inhérente aux perfonnances foequentielles accrue. . . . Des semi-oenducteurs et au besoin de compacité lui aussi grandissant rend leur coaception de plus en plus délicate. L'utilisation de composants modem. Es,à fort pouvoir de commutation ne permet plus de négliger lel\. CaractériMiquel\ électrique~ de~ connexionl\ tant vi~-à-vis del\ surten~ions inadmil\sibles lors de )'ouvenure del\ semi-conducteur!\ que pour leur mise en parallèle dans le~ !\tructures de forte pui~sance. La caraetéri~ation des impédances de câblage avant la réalisation du prototype reste la voie privilégiée dans la conception des structures qui permettra de diminuer les coûts et les délais. Pour ce faire. La modélisation des connexions passe par la simulation. _ InCa. Logiciel destiné à la prédétermination des inductances de câblage en utilisant la méthode PEEC. A été développé pour ~c;urer cette étape de la conception. Une méthodologie de modélisation a été mise au point. Elle consiste à rechercher le schéma électrique équivalent des connexions en prenant en compte aussi bien l'effet de la fréquence, des connexions voisines que la présence d'un plan de masse. Le couplage automatique de InCa avec un simulateur électrique, SPICE par exemple. Permet d'intégrer les résultats de la simulation sur Inca et d'obtenir les formes en courant et tension du convertisseur. InCa. Dont la base de données, orientée objets. Est adaptée à la méthode de résolution. A pennis, de caractériser différentes technologies de câblage. Allant du circuit intégré. De la technologie hybride jusqu'à la technologie bus barn: de plus en plus utilisée dans les structures d'Electronique de Puissance
The augmentation of technological level of power static converters due to increasing frequency performances of semi-conductors and due to the need of redueing the sizes of the structures makes their design more and more tricky. The use of up-to-date components with high power of commutation does not allow to negleet the electrical characteristies of connections not only face to inadmissible overvoltages when semiconductors turn on but also when for their a. ~sociation in parallel in high power structures. The characterization of cabling impedances before the realization of the prototype remains the privileged way in the design of structures which allows to reduce costs and delays. For this, the simulation is necessary to model connections. InCa. Simulation 1001 dedicated 10 the characterization of cabling inductances using PEEC method' has been developped to ensure this stage of design. A method for modelling has been established. It consists in looking for the equivalent electrical circuit of connections considering not only the skin and proximity em~Cb but al~o the presence of a ground plane. The automatÎc coupling of InCa with an clectrical simulation tool such as SPICE atlows to use the results given by InCa in order to obtain the cuurent and voltage wave fonn. ~ of the converter. InCa whose database is adapted to the solving method has a110wed to characterize varioul\ cabling technologies from integrclted circuit. Hybrid technology to bus bar technology more and more used in the power electronics structures

碩士
國立交通大學
電機學院電機與控制學程
100
In recent years, with the increasing demand of portable products, used to provide system power of portable products with small size and high performance voltage regulator becomes more and more important. Constant on-time control regulators are preferred in practice for several important advantages, such as simple system structure, fast response time and high efficiency for light load. In general, constant on-time control regulators regulate their output voltage based on the ripple component in the output signal. Basically, requires the use of large equivalent series resistance (ESR) of the output capacitance can be effectively controlled system. As a low-cost advantage, multilayer ceramic capacitors (MLCC) are widely used in consumer power management chip, but its equivalent series resistance is very small. In conventional constant on-time control with small ESR value on the output capacitor, the regulator is easily affected by the noise due to small output ripple, which is dominated by the ripple on the output capacitor. Therefore, this paper proposes new constant on-time control regulator structure can improve the noise margin, to eliminate the equivalent in series inductance (ESL) and the small equivalent series resistance (ESR) effect. Furthermore, since the on-time period is set simply by input and output voltages, the switching frequency in continuous conduction mode (CCM) operation is relatively constant over a wide input voltage range. Simulation results show that the output ripple keeps around 2mV, when load current step is 600mA and ESR is smaller than 5mΩ.

碩士
國立雲林科技大學
電子與光電工程研究所碩士班
100
This work presents the method to enhance the linearity of current integration. Through utilizing the parasitic model of capacitance and low pass filter with negative impedance converter, we develop an extraction method to estimate parasitic components of capacitor concerning with linearity of integration. The further use of negative impedance converter provides adjustable negative impedance for compensating redundant parasitic components. The resulted impedance is almost ideal current source and pure capacitance enabling the possibility of very linear current integration. The simulation results show that the proposed method is able to generate very linear ramp signal for constant current source. The differential and integral nonlinearity of integration is reduced to 11.25 and 23 times respectively as compared with the situation without compensating.

碩士
國立雲林科技大學
電子工程系
102
This work present a method to enhance linearity of triangle wave generator and calibration of negative impedance converter(NIC). Through developing the extraction method to estimate parasitic components, using negative impedance converter(NIC) to compensate the triangle wave generator. However, the negative impedance converter(NIC) offset cause a problem, which inhabit the effect of improving the linearity of triangle signal. The further, we use an impedance sensor to estimate the offset value of negative impedance converter(NIC), and we calculate the new value of impedance senor to replace estimated value generated by the negative impedance converter(NIC). Therefore, we can use the calibration method to eliminate the offset error and prepare for the second calibration which we can achieve a highly linear triangle wave generator. The simulation result shows that the proposed method is able to generate very linear triangle wave signal for constant current source. The differential and integral nonlinearity of triangle wave generator can be reduced one-second times by the calibration. Finally, we can achieve a 13 bits linear triangle wave generator. Keywords: Triangle Wave Generator, Parasitic Component, Negative Impedance Converter(NIC), Impedance Sensor, Differential Nonlinearity(DNL), Integral Nonlinearity(INL).

碩士
國立清華大學
電子工程研究所
106
Since dimensions of device channel shrink, several Short Channel Effects (SCEs) appear. The FinFET which provides excellent gate control over short channel effects is considered one of the major solutions. However, the three-dimension device provides a lot of parasitic components which reduce the performance. The parasitic components of FinFET become one of the key limiting factors in achieving the target device performance beyond the 10 nm technology node. The object of this thesis is to establish the effects of FinFET model on its parasitic capacitances, parasitic resistances, and RC time constant with 3D device simulations. The gate to spacer capacitance is the most dominant parasitic capacitance. It ramps up from a negligible weight of 19.8% to 25.5%. The Source/Drain contact resistance is the most dominant resistance. It ramps up from a negligible weight of 10.7% to 33.1%. Moreover, the RC time constant is an upward trend beyond the 10nm technology node. At last, by adjusting the fin height and the fin width, the parasitic capacitances and resistances with respect to fin geometry of FinFET are analyzed. In order to improve the performance of the device, the device geometry has to be optimized.

Magnetic components, such as inductors and transformers, have important effects on the efficiency and performance of switching power supplies; their parasitic properties directly impact the high frequency properties which can cause lot-to-lot variation or unanticipated and non-ideal operation. They are also amongst the most problematic components to design, often requiring numerous design-prototype-test interactions. The electrostatic and electromagnetic analysis of wound components has become more important recently to predict their performance and frequency behavior. Accurate prediction and design of winding parasitic parameters of leakage inductance and winding capacitance for high frequency inductors and transformers in switching power supplies is fundamental to improve performance, lower cost, and speed time to market. This thesis presents a methodology and process to obtain accurate prediction of the inter- and intra-winding capacitances of high frequency magnetic components. Application examples considered are a single-winding choke, a coupled inductor filter, and a multi-winding transformer. Analytical approach for determination of parasitic capacitances in high frequency magnetic components will be covered also. Comparison of the FEA results using JMAG with experimental and empirical formula results show good agreement, supporting the method as a model-based design tool with the potential to significantly reduce the design-prototype-test cycle commonly needed with sophisticated magnetic designs.