An aim of this work is a research of a deposition process of indium tin oxide by plasma assisted methods. The thesis deals with plasma diagnostics, e.g. Langmuir probe diagnostics and optical emission spectroscopy, as well as describes experiments of film deposition including their diagnostics, e.g. absorption spectroscopy, X-ray diffractometry and atomic force microscopy.

Problemas de resfriamento de circuitos, presentes nas indústrias de eletrônicos e miniaturizados, têm sido amplamente estudados com o propósito de desenvolver mecanismos capazes de reduzirem a taxa de falha nos equipamentos devido às altas temperaturas. O presente trabalho utiliza o método Design Construtal associado com algoritmos de otimização, busca exaustiva e algoritmo genético, para realizar o estudo numérico de corpos sólidos com geração de calor uniforme onde são inseridos caminhos altamente condutivos em forma de “Y”, “Y-Y”, duplo “Y-Y” e “T”. O objetivo principal das otimizações realizadas consiste em minimizar a resistência ao fluxo de calor, quando as áreas ocupadas pelos materiais de alta e baixa condutividades são mantidas constantes, variando-se os comprimentos e espessuras dos caminhos condutivos. Para a solução numérica da equação da difusão do calor com as condições de contorno estabelecidas em cada caso, foi utilizado o PDETool do software MatLab. A formulação para o caminho condutivo em forma de “Y” apresenta a construção de volumes elementares, mantendo a mesma condutividade térmica para todo o caminho condutivo. Na configuração em forma de duplo “Y – Y” foi utilizado o método de busca exaustiva associado ao algoritmo genético (GA). Nas simulações realizadas com o caminho condutivo em forma de “T”, a configuração apresenta combinações de condutividade térmica diferentes para a base e para a parte superior, enfatizando que a geometria depende das condições impostas pelo ambiente. Para o caso com um volume elementar, a configuração em forma de “Y” degenera-se gerando um caminho condutivo em forma de “U” e com dois volumes, a variação ocorre no comprimento dos ramos do caminho condutivo. Para a configuração com quatro volumes, a configuração ótima tem a forma de “X”. No caso do caminho em forma de “T”, a configuração que minimiza a máxima temperatura em excesso tem a forma de um “I”. Como previsto no princípio da ótima distribuição das imperfeições, a geometria ótima para os casos estudados é aquela que melhor distribui as imperfeições do sistema. / Problems that embody cooling of circuits that appears in electronics and miniaturized industries, have been widely studied to develop mechanisms capable of reducing the failure rate of the equipment due to high temperatures. The present work applies the Constructal Design method associated with optimization algorithms, exhaustive search and genetic algorithm, to perform the numerical study of solid bodies with uniform heat generation in which are inserted high-conducting pathways with “Y”, “Y–Y”, double “Y–Y” and “T” shapes. The main goal of the performed optimizations consists in minimizing the resistance to the heat flux when the occupied areas of high and low conductivity materials are maintained constant, varying the lengths and thickness of conductive paths. For the numerical solution of the heat diffusion equation with the boundary conditions established in each case, it was used the PDETool from MatLab software. The formulation for the conductive pathway with "Y" shape presents the construction of elementary volumes, maintaining the same thermal conductivity across the entire conductive pathway. In the configuration in double “Y–Y” form it was used exhaustive search method associated with genetic algorithm (GA). In the simulations performed with the T-shaped conductive pathway, the configuration provides combinations of different thermal conductivity for the base and the top, emphasizing that the geometry depends on the conditions imposed by the environment. For the case with one elementary volume, the Y-shaped configuration degenerates producing a conductive pathway with U-shape; and with two volumes, the variation occurs in the length of branches of the conductive pathway. For the configuration with four volumes, the optimum configuration has the form of “X”. In the case of T-shaped pathway, the configuration that minimizes the maximal excess of temperature is I-shaped. As predicted by the principle of optimal distribution of the imperfections, the optimal geometry for the cases studied is the one that promotes the best distribution of the imperfections of the system.

With the rapid growth and use of wearable devices over the last decade, the advantages of using portable wearable devices are now been utilised for day to day activities. These wearable devices are designed to be flexible, low profile, light-weight and smoothly integrated into daily life. Wearable transmission lines are required to transport RF signals between various pieces of wearable communication equipment and to connect fabric based antennas to transmitters and receivers; the stitched transmission line is one of the hardware solutions developed to enhance the connectivity between these wearable devices. Textile manufacturing techniques that employ the use of sewing machines alongside conductive textile materials can be used to fabricate the stitched transmission line. In this thesis the feasibility of using a sewing machine in fabrication of a novel stitched transmission line for wearable devices using the idea of a braided coaxial cable have been examined. The sewing machine used is capable of a zig-zag stitch with approximate width and length within the range of 0-6 mm and 0-4mm respectively. The inner conductor and the tubular insulated layer of the stitched transmission lines were selected as RG 174, while the stitched shields were made up of copper wires and conductive threads from Light Stiches®. For shielding purpose, the structure is stitched onto a denim material with a conductive thread with the aid of a novel manufacturing technique using a standard hardware. The Scattering Parameters of the stitched transmission line were investigated with three different stitch angles 85°, 65° and 31° through simulation and experiments, with the results demonstrating that the stitched transmission line can work usefully and consistently from 0.04 to 4GHz. The extracted Scattering parameters indicated a decrease in DC loss with increased stitch angle and an increase in radiation loses, which tends to increase with increase in frequency. The proposed stitched transmission line makes a viable transmission line but a short stitch length is associated with larger losses through resistance. The DC losses observed are mainly influenced by the resistance of the conductive threads at lower frequencies while the radiation losses are influenced by the wider apertures related to the stitch angles and increase in frequency along the line. The performances of the stitched transmission line with different stitch patterns, when subjected to washing cycles and when bent through curved angles 90° and 180° were also investigated and results presented. Also, the sensitivity of the design to manufacturing tolerances was also considered. First the behaviour of the stitched transmission line with two different substrates Denim and Felt were investigated with the results indicating an insignificant increase in losses with the Denim material. Secondly, the sensitivity of the design with variations in cross section dimensions was investigated using numerical modelling techniques and the results showed that the impedance of the stitched transmission line increases when the cross sectional dimensions are decreased by 0.40mm and decreases when the cross sectional dimensions are increased by 0.40mm. Equally, repeatability of the stitched transmission line with three different stitch angles 85°, 65° and 31° were carried out. The results were seen to be consistent up to 2.5GHz, with slight deviations above that, which are mainly as a result of multiple reflections along the line resulting in loss ripples. The DC resistance of the stitched transmission line with three different stitch angles 85°, 65° and 31° corresponding to the number of stitches 60,90 and 162 were computed and a mathematical relationship was derived for computing the DC resistance of the stitch transmission line for any given number of stitches. The DC resistance computed results of 25.6Ω, 17.3Ω and 13.1Ω, for 31°, 65° and 85° stitch angles, indicated an increase in DC resistance of the stitch with decrease in stitch angle which gives rise to an increase in number of stitches. The transfer impedance of the stitched transmission line was also computed at low frequency (< 1GHz) to be ZT=(0.24+j1.09)Ω, with the result showing the effectiveness of the shield of the stitched transmission line at low frequency (< 1GHz).

Les travaux réalisés traitent de la caractérisation en fatigue thermique et mécanique d’assemblages collés par colle conductrice isotrope. Issu du domaine des circuits électroniques radio fréquences à applications spatiales, l’empilement type considéré dans l’étude est constitué d’un carré d’alumine reporté de manière automatique sur un support en Kovar.L’adhésif est à base d’époxyde chargé de microparticules d’argent pour la conduction électrique et thermique du report.Les surfaces de collage de l’alumine sont polies-rectifiées et dorées pour favoriser les fonctions RF, au détriment de la tenue du collage. L’objectif principal est l’identification des mécanismes de fatigue de l’assemblage face aux sollicitations thermiques subies pendant des essais de qualification thermiques réalisés au sol, qui se veulent représentatives de celles subies en orbite pendant toute la durée de la mission. Deux axes de recherche sont privilégiés dans cette étude. D’une part, le comportement du matériau adhésif est caractérisé par des essais de fluage et des essais cyclés réalisés sur des éprouvettes de colle. Le modèle viscoplastique Two-Layers est retenu et implémenté dans un modèle éléments finis de l’assemblage. La tenue de la colle aux interfaces constitue une seconde approche de caractérisation. Une faible tenue en mode I est constatée à l’issue d’une campagne DCB. D’autre part, deux plans d’expériences portant sur la géométrie et les conditions de report des assemblages sont réalisés en parallèle d’une étude paramétrique numérique. Ces deux approches complémentaires permettent de proposer des hypothèses relatives aux mécanismes de fatigue prépondérants au sein de l’assemblage dans son environnement thermique. La tenue en fatigue des collages s’avère très dépendante du procédé automatique qui insère de nombreux défauts (porosités) à l’interface du composant. Une caractérisation en fatigue par essai mécanique est proposée comme alternative au cyclage thermique lent en étuve. Bien que l’équivalence ne soit pas complète, les résultats présentent de bonnes perspectives pour aider à la caractérisation en fatigue de l’interface entre des composants céramiques et une colle conductrice. / This subject deals with the fatigue life characterization under thermal and mechanical loads of bonded assemblies with anisotropic conductive adhesive. In the framework of radio frequency electronics for space applications, the stack of study iscomposed of an alumina square bonded onto a Kovar plate following an automatic process. The adhesive is made of anepoxy based matrix loaded with silver flakes for electrical and thermal conduction. Surfaces of adhesion are polished andcoated with gold to improve RF functions despite the reduction of adherence. The main objective is to identify the fatigue mechanisms taking place in the assembly under thermal cycling due to its orbital environment during the mission and some representative on-ground qualification tests. The study is divided into two parts. First of all, the mechanical behavior of the adhesive is completely characterized by creep and recovery tests and cycling tests performed on bulk specimens. The model of material behavior, called Two-Layers, is identified and implemented in a finite elements model of the whole assembly. The adhesive resistance at the bonding interfaces is also studied. A certain weakness in mode I is observed from a DCB campaign. Secondly, two designs of experiments on geometry and thermal conditions are performed in parallel of a numerical parametric study. These two complementary approaches allow proposing some hypothesis upon the fatigue mechanisms occurring in the assembly under thermal cycling. The fatigue resistance of bonded assemblies depends on the automatic bonding process that creates numerous defects at the component interface (as porosities). A fatigue life characterization by the help of a mechanical test is proposed as an alternative to slow thermal cycling in an oven. Although, the equivalence is not entirely proven, results are promising and can help further with the fatigue study of the interface between such ceramic components and a conductive adhesive.

Made available in DSpace on 2015-07-22T20:50:31Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-01-28 / Objetivo: verificar a ocorrência das alterações auditivas em recém nascidos que participaram do Programa de triagem auditiva neonatal de um Hospital Público (UNIFESP- Brasil) no período de 2005 a 2007 e verificar se os recém nascidos que falharam na triagem auditiva por comprometimento condutivo tem mais episódios de perda condutiva durante os primeiros anos de vida do que aqueles que não falharam. Métodos: 0 estudo foi dividido em duas partes. A primeira parte foi retrospectiva analisando-se 0 diagnóstico audiol6gico de 231 (de mil novecentos e noventa e seis) recém nascidos que falharam na triagem auditiva e sua associação com a idade gestacional, 0 peso ao nascimento e as principais intercorrências neonatais. Na segunda parte compararam-se os 62 recém nascidos que falharam na triagem auditiva por comprometimento condutivo com os 221 recém nascidos que passaram na triagem auditiva. Foi feito 0 acompanhamento por meio de EOAT, imitanciometria e avaliação comportamental. Foram utilizados para analise estatística 0 teste Exato de Fisher e modelos de Regressão Logística. Resultados: A incidência de alterações auditivas na população estudada foi de 11,5%, sendo 8,4% de perda condutiva, 1 % de perda neurossensorial, 2% de alteração central. As crianças que falharam na triagem por alteração condutiva tiveram mais episódios de perda condutiva (estatisticamente significante) durante 0 primeiro ano de vida que as crianças que não falharam. Conclusões: Houve maior ocorrência de perda auditiva condutiva dentre as alterações auditivas estudadas. Os neonatos que falharam na triagem auditiva neonatal no primeiro mês de vida por alteração condutiva tem maior chance de terem perda auditiva condutiva ao longo do primeiro ano de vida. / TEDE / BV UNIFESP: Teses e dissertações

Orientador: Prof. Dr. Hugo Barbosa Suffredini / Dissertação (mestrado) - Universidade Federal do ABC. Programa de Pós-Graduação em Ciência e Tecnologia/Química, 2016. / O objetivo deste trabalho foi o de apresentar um novo material com característica condutora, obtido a partir da eletrooxidação do fármaco cloridrato de amiodarona. Foram utilizados o eletrodo de carbono impresso, eletrodo de platina, carbono vítreo e diamante dopado com boro (DDB) e a técnica de voltametria cíclica para a deposição do material. O material depositado foi caracterizado aplicando-se a técnica de Microscopia Eletrônica de Varredura (MEV) que possibilitou a visualização do material depositado nos diferentes materiais dos eletrodos. Com o uso da Espectroscopia de Energia Dispersiva (EDS), obteve-se uma análise química qualitativa do filme aderido ao eletrodo de carbono impresso, que indicou a presença de átomos de iodo, elemento presente na molécula de cloridrato de amiodarona, confirmando a deposição do fármaco estudado. A análise por UV-vis também confirmou a adesão do material, quando dissolvido em N-metil-2-Pirrolidona. Análises de ângulo de contato indicaram o caráter mais hidrofílico do material, quando comparado com o substrato não modificado. Finalmente, pôde-se concluir que ocorreu a formação de um filme condutor oriundo da molécula de cloridrato de amiodarona. / The aim of this work was to synthesize a new conductive material from the drug amiodarone hydrochloride. Several carbonaceous materials were used as substrate, as glassy carbon, boron-doped diamond and screen-printed carbon electrode. Platinum electrodes were also used with the same purpose. All synthesized materials were characterized by Scanning Electron Microscopy (SEM), which enabled the visualization of the modifications for all studied materials. Energy Dispersive Spectroscopy (EDS) were used to promote the qualitative analysis of the samples, indicating the presence of iodine atoms, an element present in the original amiodarone molecule. UV-vis spectroscopy also confirmed the adhesion of the material. Contact angle analysis indicates that the modification has the surface more hydrophobic than the pristine material. Finally, it was possible to conclude that a conductor film from amiodarone hydrochloride was adequately synthesized in all studied substrates.

abstract: Alternative computation based on neural systems on a nanoscale device are of increasing interest because of the massive parallelism and scalability they provide. Neural based computation systems also offer defect finding and self healing capabilities. Traditional Von Neumann based architectures (which separate the memory and computation units) inherently suffer from the Von Neumann bottleneck whereby the processor is limited by the number of instructions it fetches. The clock driven based Von Neumann computer survived because of technology scaling. However as transistor scaling is slowly coming to an end with channel lengths becoming a few nanometers in length, processor speeds are beginning to saturate. This lead to the development of multi-core systems which process data in parallel, with each core being based on the Von Neumann architecture. The human brain has always been a mystery to scientists. Modern day super computers are outperformed by the human brain in certain computations. The brain occupies far less space and consumes a fraction of the power a super computer does with certain processes such as pattern recognition. Neuromorphic computing aims to mimic biological neural systems on silicon to exploit the massive parallelism that neural systems offer. Neuromorphic systems are event driven systems rather than being clock driven. One of the issues faced by neuromorphic computing was the area occupied by these circuits. With recent developments in the field of nanotechnology, memristive devices on a nanoscale have been developed and show a promising solution. Memristor based synapses can be up to three times smaller than Complementary Metal Oxide Semiconductor (CMOS) based synapses. In this thesis, the Programmable Metallization Cell (a memristive device) is used to prove a learning algorithm known as Spike Time Dependant Plasticity (STDP). This learning algorithm is an extension to Hebb’s learning rule in which the synapses weight can be altered by the relative timing of spikes across it. The synaptic weight with the memristor will be its conductance, and CMOS oscillator based circuits will be used to produce spikes that can modulate the memristor conductance by firing with different phases differences. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2015

Orientador: Chang Hung Kiang / Banca: Walter Malagutti Filho / Banca: Vagner Roberto Elis / Resumo: Visando caracterizar assinaturas geoelétricas em áreas contaminadas por hidrocarbonetos de petróleo, foram realizados levantamentos geofísicos utilizando-se os métodos da eletrorresistividade e análises hidroquímicas em área localizada no Pólo Industrial de Cubatão - SP. Foram realizadas 19 sondagens elétricas verticais (SEVs), 4 imageamentos elétricos 2D e 3 imageamentos elétricos 3D, tendo sido identificadas, por meio destas técnicas, 12, 21 e 9 anomalias, respectivamente. Constatou-se que a presença de anomalias condutivas na zona não saturada coincide com a ocorrência de fase livre nos poços de monitoramento. A identificação de NH4 +, subjacente à ocorrência de fase livre, confirmou a atuação de processo de denitrificação. As baixas concentrações dos íons sulfato (SO4 2-) e ferroso (Fe2+) indicam que os mesmos foram reduzidos biologicamente para sulfeto (S2-) e precipitado como sulfeto de ferro (FeS), respectivamente. Esses resultados permitem concluir que as anomalias condutivas estão diretamente associadas à presença de fase residual de hidrocarbonetos, em processo de biodegradação, na zona não saturada. Desta forma, os métodos de investigação geofísica utilizados permitiram identificar áreas sob influência de hidrocarbonetos de petróleo. / Abstract: Geophysical surveys using electroresistivity methods and hydrochemical analyses were applied aiming the characterization of geoelectrical signatures in hydrocarbon contaminated sites located in the Polo Industrial de Cubatão - SP. There have been accomplished nineteen vertical electric soundings (VESs), four 2D and three 3D electrical imaging, which identified 12, 21 and 9 geophysical anomalies respectively. It was verified that the presence of conductive anomalies within the non-saturated zone coincided with the occurrence of free phase on the monitoring wells. Ammonium (NH4 +) identification, underlying the free phase occurrence, reinforced the activity of denitrifying process. Additionally, low concentration values of sulfate (SO4 2-) and ferrous (Fe2+) ions indicated that they were, respectively, biologically reduced to sulfide (S2-) and precipitated as iron sulfide (FeS). Based on those results, it was concluded that the conductive anomalies detected inside the non-saturated zone were directly associated with the presence of hydrocarbon residual phase, with was undergoing a biodegradation process. Therefore, the geophysical methods applied in this study allowed the identification of sites under petroleum hydrocarbons influence. / Mestre

Problemas de resfriamento de circuitos, presentes nas indústrias de eletrônicos e miniaturizados, têm sido amplamente estudados com o propósito de desenvolver mecanismos capazes de reduzirem a taxa de falha nos equipamentos devido às altas temperaturas. O presente trabalho utiliza o método Design Construtal associado com algoritmos de otimização, busca exaustiva e algoritmo genético, para realizar o estudo numérico de corpos sólidos com geração de calor uniforme onde são inseridos caminhos altamente condutivos em forma de “Y”, “Y-Y”, duplo “Y-Y” e “T”. O objetivo principal das otimizações realizadas consiste em minimizar a resistência ao fluxo de calor, quando as áreas ocupadas pelos materiais de alta e baixa condutividades são mantidas constantes, variando-se os comprimentos e espessuras dos caminhos condutivos. Para a solução numérica da equação da difusão do calor com as condições de contorno estabelecidas em cada caso, foi utilizado o PDETool do software MatLab. A formulação para o caminho condutivo em forma de “Y” apresenta a construção de volumes elementares, mantendo a mesma condutividade térmica para todo o caminho condutivo. Na configuração em forma de duplo “Y – Y” foi utilizado o método de busca exaustiva associado ao algoritmo genético (GA). Nas simulações realizadas com o caminho condutivo em forma de “T”, a configuração apresenta combinações de condutividade térmica diferentes para a base e para a parte superior, enfatizando que a geometria depende das condições impostas pelo ambiente. Para o caso com um volume elementar, a configuração em forma de “Y” degenera-se gerando um caminho condutivo em forma de “U” e com dois volumes, a variação ocorre no comprimento dos ramos do caminho condutivo. Para a configuração com quatro volumes, a configuração ótima tem a forma de “X”. No caso do caminho em forma de “T”, a configuração que minimiza a máxima temperatura em excesso tem a forma de um “I”. Como previsto no princípio da ótima distribuição das imperfeições, a geometria ótima para os casos estudados é aquela que melhor distribui as imperfeições do sistema. / Problems that embody cooling of circuits that appears in electronics and miniaturized industries, have been widely studied to develop mechanisms capable of reducing the failure rate of the equipment due to high temperatures. The present work applies the Constructal Design method associated with optimization algorithms, exhaustive search and genetic algorithm, to perform the numerical study of solid bodies with uniform heat generation in which are inserted high-conducting pathways with “Y”, “Y–Y”, double “Y–Y” and “T” shapes. The main goal of the performed optimizations consists in minimizing the resistance to the heat flux when the occupied areas of high and low conductivity materials are maintained constant, varying the lengths and thickness of conductive paths. For the numerical solution of the heat diffusion equation with the boundary conditions established in each case, it was used the PDETool from MatLab software. The formulation for the conductive pathway with "Y" shape presents the construction of elementary volumes, maintaining the same thermal conductivity across the entire conductive pathway. In the configuration in double “Y–Y” form it was used exhaustive search method associated with genetic algorithm (GA). In the simulations performed with the T-shaped conductive pathway, the configuration provides combinations of different thermal conductivity for the base and the top, emphasizing that the geometry depends on the conditions imposed by the environment. For the case with one elementary volume, the Y-shaped configuration degenerates producing a conductive pathway with U-shape; and with two volumes, the variation occurs in the length of branches of the conductive pathway. For the configuration with four volumes, the optimum configuration has the form of “X”. In the case of T-shaped pathway, the configuration that minimizes the maximal excess of temperature is I-shaped. As predicted by the principle of optimal distribution of the imperfections, the optimal geometry for the cases studied is the one that promotes the best distribution of the imperfections of the system.

In this study, bulk conductivity of commercial base paper impregnated with different ionic liquids blends and additives, through bench coating was investigated. Bulk conductivity of base paper, ion conductive paper and surface sized ion conductive papers with and without the influence of calendering were evaluated at different concentrations of ionic liquids using at resistivity cell and four point probe technique. It was shown that bulk conductivity of base paper was increased by increasing the amount of ionic liquids. Nano fibril cellulose also showed positive influence on the bulk conductivity of coated papers. By increasing the line load in the calendering machine, a positive influence on the bulk conductivity was observed. The tensile index of all the coated papers was lower than that of the base paper.