Introdução:As adaptações neurais ao treinamento físico vêm sendo amplamente estudadas e a medula espinhal é um dos locais de possível adaptação. No entanto nenhuma avaliação longitudinal havia sido feita diretamente sobre as circuitarias inibitórias medulares. Até o presente momento as alterações eram somente suposições. O presente trabalho verificou as circuitarias medulares responsáveis pela inibição recíproca (IR) e inibição pré-sináptica (IPS) em sujeitos submetidos a diferentes treinamentos. Materiais e Métodos: Para o treino aeróbico (resistência) foram avaliados 25 soldados submetidos ao treinamento militar do Exército Militar Brasileiro. Foram feitas 3 avaliações uma pré-treino e outras duas com 3 e 9 meses após o inicio das atividades no ano de 2006. Outros 29 sujeitos foram divididos em 3 grupos: controle (permaneceram 8 semanas sem atividades de reinamento), grupo de treino de força máxima e treino de potência. Eles foram submetidos a 8 semanas de treino, realizado com séries de agachamento livre com peso. Para avaliação das circuitarias medulares foi utilizado o reflexo H do sóleus condicionado com estímulos no nervo fibular comum (NFC) - que inerva o músculo tibial anterior (TA). O intervalo entre o estímulo condicionante e o estímulo teste determinou a avaliação da IR, da inibição D1 e da inibição D2 (IPS). Outras variáveis também foram calculadas como: contração voluntária máxima isométrica (CVM) do sóleus e TA e seus respectivos eletromiogramas (EMG), relação elétrica e mecânica entre Hmax/Mmax e condicionamento do EMG do sóleus por estímulos no NFC. Foram feitas análises pareadas com teste t-student para o grupo militar e ANOVA two-way para comparação dos grupos de força máxima e potência com o grupo controle. Principais Resultados: O grupo do exército apresentou aumento na força do sóleus e do TA, juntamente com aumento no RMS do EMG do sóleus e do torque gerado pela onda Mmax, sem alterações nos relações Hmax/Mmax. O treinamento militar reduziu significativamente a inibição D1 e mostrou tendências a aumento da IPS. O grupo de força máxima não mostrou aumento de força isométrica, no entanto apresentou aumento na relação elétrica Hmax/Mmax, com concomitante redução da IR e aumento da IPS. O grupo de potência mostrou ganho na força máxima isométrica somente do sóleus. A capacidade de gerar torque reflexamente também aumentou neste grupo, com aumento significativo na relação mecânica Hmax/Mmax. Esta melhora na utilização do arco reflexo também foi verificada com redução da IPS e aumento da IR neste grupo.Conclusões: Estes resultados mostraram que a medula espinal sofre plasticidade nas vias inibitórias IR, inibição D1 e D2, e que esta plasticidade é dependente do tipo de tarefa realizada. / Introduction: Neural adaptations with physical training have been widely studied. The spinal cord is a possible locus of adaptation. However, longitudinal studies that evaluate directly the spinal cord pathways have not been found in the literature. Therefore, all reports from the literature justify changes found in measured responses to exercise by hypotheses on spinal cord mechanisms. This study had the objective of measuring features of specific spinal cord pathways to check if they change according to the type of physical training. The pathways related to reciprocal inhibition (RI) and pre-synaptic inhibition (PSI) were investigated in subjects undergoing different trainings. Materials and Methods: For endurance training 25 soldiers were subjected to military training of the Brazilian Army. Evaluations were made three times, one previous to the beginning of the activity and twice post-training (within 3 and 9 months). Other 29 subjects were divided into: control group (with no training), maximal strength group and power group. They were subjected to 8 weeks of training with series of squat movements. The soleus H reflex conditioning with stimuli in the common peroneal nerve (CPN) was used to evaluate the spinal cord pathways. The interval between the conditioning and the test stimulus determine the assessment of RI, D1 inhibition and D2 inhibition (PSI). Other variables were also calculated: maximum voluntary isometric contraction from soleus and tibialis anterior and their electromyograms (EMG), electrical and mechanical Hmax/Mmax ratio and 3 inhibitions over the soleus EMG conditioned by stimuli to the CPN. The results were analyzed with paired t-student test for the military group and with two-way ANOVA to compare the maximal strength and power groups with the control group. Main Results: The military group had increased strength of the soleus and the TA muscles, with an increase in the RMS of the soleus EMG. This group also increased the torque generated by the Mmax-wave, without changes in Hmax/Mmax ratio. The military training significantly reduced D1 inhibition and showed tendencies to increase the PSI. The maximal strength group showed no differences in isometric strength, but had increased Hmax/Mmax ratio with concomitant reduction of RI and increased PSI. The power group increased isometric strength only for the soleus muscle. This group also improved the ability to generate torque by reflex pathways, with significant increase in the mechanical Hmax/Mmax ratio, with a reduction of PSI and increase of RI. Conclusions: These results show that spinal cord plasticity occurs in the inhibitory pathways of reciprocal inhibition, D1 inhibition and D2 inhibition (pre-synaptic inhibition), and that plasticity is dependent on the type of trained movement.

Nanotecnologia é o conjunto de conhecimentos acumulados pelo homem que permite controlar a produção de estruturas com uma ou mais dimensões nanométricas. Desde seus primórdios na década de 70, a nanotecnologia tem estado em constante ascensão, encontrando uma diversidade enorme de aplicações, como por exemplo em medicina e na indústria optoeletrônica. Por consequência, a demanda por equipamentos tanto de preparo como de caracterização/controle tem crescido exponencialmente. O uso da radiação X no estudo de dispositivos nanoestruturados tem sido, em grande parte, possível gra- ças as fontes síncrotrons com feixes intensos. Mas a disponibilidade desses laboratórios de alta tecnologia está aquém da crescente demanda das pesquisas em nanotecnologia, as quais precisam de técnicas de análise estrutural rápidas e de fácil acesso para otimização e controle da produção de dispositivos nanoestruturados. Com foco nessa falta por técnicas de análise estrutural, esta dissertação tem como objetivo avaliar quais parâmetros básicos de nanodispositivos, com substratos monocristalinos, podem ser investigados por meio de técnicas de difração de raios X utilizando fontes compactas de radiação, bem como avaliar as limitações instrumentais. / X-ray radiation has provided a powerful tool for analyzing the structure of materials at atomic scale. While many are fascinated with the perspectives oered by advanced X-ray sources, the practical aspects of these perspectives in the actual and future scenery of nanotechnology needs to be discussed. Nanotechnology, i.e. the capacity of controlling matter at atomic-molecular scales and manufacturing structures with dimensions of a few tens of nanometers, has provided a constant challenge for structural analysis via X-ray techniques. The great diversity of materials and methods derived from nanotechnology is generating a huge demand for time of analysis, much beyond of that can be supplied by synchrotron facilities worldwide. In optimizing nanostructured materials and devices processing methods, fast and easy-access techniques to control and characterization are required. Microscopy and spectroscopy techniques are very important in this scenery, but they have intrinsic limitations that have justied the search for high-resolution techniques of structural analysis, such as those obtained by diraction of X-rays. The use of Xradiation in the study of nanostructured device has been possible by synchrotron sources due to the high intense beams. But the availability of these high tech laboratories falls short of the growing demand for nanotechnology research. In this context, this dissertation intend evaluate which basic parameters of nanodevices with single crystal substrates can be investigated by techniques of X-ray diraction using compact radiation sources as well how to evaluate the instrumental limitations .

Human sensorimotor control is remarkably adept at utilising contextual information to learn and recall systematic sensorimotor transformations. Here, we investigate the motor representations that underlie such learning, and examine how motor memories acquired based on different contextual information interact. Using a novel three-dimensional robotic manipulandum, the 3BOT, we examined the spatial transfer of learning across various movement directions in a 3D environment, while human subjects performed reaching movements under velocity-dependent force field. The obtained pattern of generalisation suggested that the representation of dynamic learning was most likely defined in a target-based, rather than an extrinsic, coordinate system. We further examined how motor memories interact when subjects adapt to force fields applied in orthogonal dimensions. We found that, unlike opposing fields, learning two spatially orthogonal force fields led to the formation of separate motor memories, which neither interfered with nor facilitated each other. Moreover, we demonstrated a novel, more general aspect of the spontaneous recovery phenomenon using a two-dimensional force field task: when subjects learned two orthogonal force fields consecutively, in the following phase of clamped error feedback, the expression of adaptation spontaneously rotated from the direction of the second force field, towards the direction of the first force field. Finally, we examined the interaction of sensorimotor memories formed based on separate contextual information. Subjects performed reciprocating reaching and object manipulation tasks under two alternating contexts (movement directions), while we manipulated the dynamics of the task in each context separately. The results suggested that separate motor memories were formed for the dynamics of the task in different contexts, and that these motor memories interacted by sharing error signals to enhance learning. Importantly, the extent of interaction was not fixed between the context-dependent motor memories, but adaptively changed according to the task dynamics to potentially improve overall performance. Together, our experimental and theoretical results add to the understanding of mechanisms that underlie sensorimotor learning, and the way these mechanisms interact under various tasks and different dynamics.

Doctor of Philosophy / Department of Human Ecology-Personal Financial Planning / D. Elizabeth Kiss / Maurice M. MacDonald / The purpose of this study was to investigate the determinants that explain and predict an individual’s propensity to perform responsible financial actions and make on-time mortgage payments. The research was guided by Social Cognitive Theory (SCT) (Bandura, 1986) and explored personal factors, environmental influences, and attributes of behavior as co-factors within a combined causal framework. Data for this study came from the publicly available, 2009, 2012, and 2015 National Financial Capability Study (NFCS) datasets. These datasets were selected for the specific questions, timeframe, and richness of the financial information provided by the respondents. Responses for each survey were weighted to be representative of Census distributions according to the American Community Survey (FINRA Investor Education Foundation, 2017). The data are weighted to be representative of each state based on age, gender, ethnicity, and education. The two variables of interest were the responsible financial actions index and mortgage payment history. To isolate the determinants of these two variables more accurately, this research adopted a multi-step approach to the analytical procedure. The analyses began with the construction of the responsible financial actions index – unifying the most fundamental responsible financial actions recommended by financial professionals into a single value. Once confirmed as a valid and reliable measure, the responsible financial actions index was explored empirically as both a dependent variable and a target variable. Further analyses involved the application of the SCT Triadic Model to develop OLS and Multinomial Logistic regression models. Utilizing a series of regression models, this study explored empirically the hypothesized relationships among variables categorized as personal factors, environmental influences, attributes of behavior, and on-time mortgage payment history. When exploring variables to predict the responsible financial actions index, the OLS regression models provided consistent findings when analyzing data from the 2009, 2012, and 2015 surveys. As predicted by the SCT Triadic Model, the following personal factors, age, subjective and objective financial knowledge, financial self-efficacy, and financial risk tolerance were significant across all three survey years. The following environmental influences were significant: income, educational attainment, and marital status. To estimate the odds of paying a mortgage on-time, a series of Multinomial Logistic regression analyses were conducted. When evaluating these results, key findings were identified across all three years of data in two models. Model 1, never late vs. late once, and Model 2, never late vs. late more than once. In Model 1, for all three years, self-efficacy was found to be predictive of on-time mortgage payment history. In Model 2, for all three years, both financial self-efficacy and the financial actions index were found to be predictive of on-time mortgage payment history. These findings contribute to the body of empirical literature related to consumer economics and personal financial planning providing insight and understanding for how financial outcomes can be improved through basic responsible financial actions. This has important implications for financial professionals, counselors, and educators given the applicable value for the responsible financial actions index. For example, these results should encourage educators to work towards identifying new pedagogical approaches for improving financial self-efficacy among students.

Introdução:As adaptações neurais ao treinamento físico vêm sendo amplamente estudadas e a medula espinhal é um dos locais de possível adaptação. No entanto nenhuma avaliação longitudinal havia sido feita diretamente sobre as circuitarias inibitórias medulares. Até o presente momento as alterações eram somente suposições. O presente trabalho verificou as circuitarias medulares responsáveis pela inibição recíproca (IR) e inibição pré-sináptica (IPS) em sujeitos submetidos a diferentes treinamentos. Materiais e Métodos: Para o treino aeróbico (resistência) foram avaliados 25 soldados submetidos ao treinamento militar do Exército Militar Brasileiro. Foram feitas 3 avaliações uma pré-treino e outras duas com 3 e 9 meses após o inicio das atividades no ano de 2006. Outros 29 sujeitos foram divididos em 3 grupos: controle (permaneceram 8 semanas sem atividades de reinamento), grupo de treino de força máxima e treino de potência. Eles foram submetidos a 8 semanas de treino, realizado com séries de agachamento livre com peso. Para avaliação das circuitarias medulares foi utilizado o reflexo H do sóleus condicionado com estímulos no nervo fibular comum (NFC) - que inerva o músculo tibial anterior (TA). O intervalo entre o estímulo condicionante e o estímulo teste determinou a avaliação da IR, da inibição D1 e da inibição D2 (IPS). Outras variáveis também foram calculadas como: contração voluntária máxima isométrica (CVM) do sóleus e TA e seus respectivos eletromiogramas (EMG), relação elétrica e mecânica entre Hmax/Mmax e condicionamento do EMG do sóleus por estímulos no NFC. Foram feitas análises pareadas com teste t-student para o grupo militar e ANOVA two-way para comparação dos grupos de força máxima e potência com o grupo controle. Principais Resultados: O grupo do exército apresentou aumento na força do sóleus e do TA, juntamente com aumento no RMS do EMG do sóleus e do torque gerado pela onda Mmax, sem alterações nos relações Hmax/Mmax. O treinamento militar reduziu significativamente a inibição D1 e mostrou tendências a aumento da IPS. O grupo de força máxima não mostrou aumento de força isométrica, no entanto apresentou aumento na relação elétrica Hmax/Mmax, com concomitante redução da IR e aumento da IPS. O grupo de potência mostrou ganho na força máxima isométrica somente do sóleus. A capacidade de gerar torque reflexamente também aumentou neste grupo, com aumento significativo na relação mecânica Hmax/Mmax. Esta melhora na utilização do arco reflexo também foi verificada com redução da IPS e aumento da IR neste grupo.Conclusões: Estes resultados mostraram que a medula espinal sofre plasticidade nas vias inibitórias IR, inibição D1 e D2, e que esta plasticidade é dependente do tipo de tarefa realizada. / Introduction: Neural adaptations with physical training have been widely studied. The spinal cord is a possible locus of adaptation. However, longitudinal studies that evaluate directly the spinal cord pathways have not been found in the literature. Therefore, all reports from the literature justify changes found in measured responses to exercise by hypotheses on spinal cord mechanisms. This study had the objective of measuring features of specific spinal cord pathways to check if they change according to the type of physical training. The pathways related to reciprocal inhibition (RI) and pre-synaptic inhibition (PSI) were investigated in subjects undergoing different trainings. Materials and Methods: For endurance training 25 soldiers were subjected to military training of the Brazilian Army. Evaluations were made three times, one previous to the beginning of the activity and twice post-training (within 3 and 9 months). Other 29 subjects were divided into: control group (with no training), maximal strength group and power group. They were subjected to 8 weeks of training with series of squat movements. The soleus H reflex conditioning with stimuli in the common peroneal nerve (CPN) was used to evaluate the spinal cord pathways. The interval between the conditioning and the test stimulus determine the assessment of RI, D1 inhibition and D2 inhibition (PSI). Other variables were also calculated: maximum voluntary isometric contraction from soleus and tibialis anterior and their electromyograms (EMG), electrical and mechanical Hmax/Mmax ratio and 3 inhibitions over the soleus EMG conditioned by stimuli to the CPN. The results were analyzed with paired t-student test for the military group and with two-way ANOVA to compare the maximal strength and power groups with the control group. Main Results: The military group had increased strength of the soleus and the TA muscles, with an increase in the RMS of the soleus EMG. This group also increased the torque generated by the Mmax-wave, without changes in Hmax/Mmax ratio. The military training significantly reduced D1 inhibition and showed tendencies to increase the PSI. The maximal strength group showed no differences in isometric strength, but had increased Hmax/Mmax ratio with concomitant reduction of RI and increased PSI. The power group increased isometric strength only for the soleus muscle. This group also improved the ability to generate torque by reflex pathways, with significant increase in the mechanical Hmax/Mmax ratio, with a reduction of PSI and increase of RI. Conclusions: These results show that spinal cord plasticity occurs in the inhibitory pathways of reciprocal inhibition, D1 inhibition and D2 inhibition (pre-synaptic inhibition), and that plasticity is dependent on the type of trained movement.

Um megaevento esportivo pode modificar o cenário de um país e influenciar na sua imagem como destino turístico, bem como na imagem da cidade que o sedia. Megaeventos, como os Jogos Olímpicos, envolvem mudanças: sociais, investimentos financeiros e de infraestrutura, e maior visibilidade internacional. A avaliação da imagem da cidade-sede pode impactar na imagem do destino ao qual ela faz parte (efeito recíproco). Partindo desse pressuposto, da importância do turismo na economia mundial/brasileira e da relação entre megaeventos esportivos e o aquecimento dessa atividade, o objetivo desta tese foi verificar os efeitos recíprocos de imagem entre a cidade-sede de um megaevento esportivo e o destino turístico ao qual ela faz parte (destino-mãe). O foco foram os Jogos Olímpicos de 2016 no Rio de Janeiro-Brasil. Foi realizada pesquisa descritiva/ quantitativa por meio de questionários fechados, com estrangeiros de 48 países (n=340), utilizando escala Likert de sete pontos. A escala foi baseada nas dimensões de imagem de destino: cognitiva e afetiva, tendo como variáveis moderadoras: a familiaridade e a animosidade com o destino-mãe e o envolvimento com os jogos. Para a análise dos dados foi utilizada a modelagem de equações estruturais VB-SEM por meio do software SmartPLS 3. Os resultados apontaram para avaliações positivas da imagem de destino, do Rio e do Brasil, identificando a dimensão cognitiva como a mais relevante. Foi confirmado efeito recíproco positivo e forte entre as imagens do Rio como sede da Olímpiadas de 2016 e Brasil como seu destino-mãe e também o contrário, contudo não foram encontrados efeitos de moderação. No caso especfício da animosidade não houve presença dessa variável em relação ao Brasil, o que é um resultado positivo. Este trabalho traz contribuições teóricas por estudar os efeitos recíprocos de imagem em destinos, especialmente considerando um contexto de megaevento esportivo e contribuições práticas para o desenvolvimento de políticas de turismo mais integrativas entre destino-mãe e cidade/ regiões do seu território e até mesmo para a captação e realização de novos grandes eventos. / A sport mega event can modify a country\'s scenery and influence its image as a tourist destination, as well as the host city image. Sports mega events such as the Olympic Games involve a series of changes: social, financial and infrastructure investments and a greater international visibility. The host city image evaluation can have an impact on the destination image to which it belongs (reciprocal effect). Based on this assumption and the importance of tourism activity in the world and Brazilian economies and the relationship between sport mega events and the warming of this activity, the objective of this thesis was to verify the image reciprocal effects between a sport mega event host city and the national tourist destination (mother-destination). The focus was the 2016 Olympic Games held in Rio de Janeiro- Brazil. Descriptive/quantitative research was performed with foreigners from 48 countries (n = 340) using structured questionnaires and a Likert seven-point scale. The scale was adapted based on the cognitive and affective destination image dimensions, having as moderating variables: familiarity and the animosity with the mother-destination and games involvement. For data analysis, PLS structural equations modeling was performed using the software SmartPLS 3. The results pointed to positive evaluations of Rio and Brazil destination images, identifying the cognitive dimension as the most relevant. A positive and strong reciprocal effect was confirmed between the images of Rio as the 2016 Olympics host city and Brazil as the mother-destination. However, no moderation effects were found and in the specific case of animosity, there was no presence of this variable related to Brazil, which was a good result. This work brings theoretical contributions because it studies the reciprocal effects in destination images, considering the context of a sport mega event, as well as practical contributions for the development of more integrative tourism policies between mother-destination, cities / regions and for the hosting of new major events.

Um megaevento esportivo pode modificar o cenário de um país e influenciar na sua imagem como destino turístico, bem como na imagem da cidade que o sedia. Megaeventos, como os Jogos Olímpicos, envolvem mudanças: sociais, investimentos financeiros e de infraestrutura, e maior visibilidade internacional. A avaliação da imagem da cidade-sede pode impactar na imagem do destino ao qual ela faz parte (efeito recíproco). Partindo desse pressuposto, da importância do turismo na economia mundial/brasileira e da relação entre megaeventos esportivos e o aquecimento dessa atividade, o objetivo desta tese foi verificar os efeitos recíprocos de imagem entre a cidade-sede de um megaevento esportivo e o destino turístico ao qual ela faz parte (destino-mãe). O foco foram os Jogos Olímpicos de 2016 no Rio de Janeiro-Brasil. Foi realizada pesquisa descritiva/ quantitativa por meio de questionários fechados, com estrangeiros de 48 países (n=340), utilizando escala Likert de sete pontos. A escala foi baseada nas dimensões de imagem de destino: cognitiva e afetiva, tendo como variáveis moderadoras: a familiaridade e a animosidade com o destino-mãe e o envolvimento com os jogos. Para a análise dos dados foi utilizada a modelagem de equações estruturais VB-SEM por meio do software SmartPLS 3. Os resultados apontaram para avaliações positivas da imagem de destino, do Rio e do Brasil, identificando a dimensão cognitiva como a mais relevante. Foi confirmado efeito recíproco positivo e forte entre as imagens do Rio como sede da Olímpiadas de 2016 e Brasil como seu destino-mãe e também o contrário, contudo não foram encontrados efeitos de moderação. No caso especfício da animosidade não houve presença dessa variável em relação ao Brasil, o que é um resultado positivo. Este trabalho traz contribuições teóricas por estudar os efeitos recíprocos de imagem em destinos, especialmente considerando um contexto de megaevento esportivo e contribuições práticas para o desenvolvimento de políticas de turismo mais integrativas entre destino-mãe e cidade/ regiões do seu território e até mesmo para a captação e realização de novos grandes eventos. / A sport mega event can modify a country\'s scenery and influence its image as a tourist destination, as well as the host city image. Sports mega events such as the Olympic Games involve a series of changes: social, financial and infrastructure investments and a greater international visibility. The host city image evaluation can have an impact on the destination image to which it belongs (reciprocal effect). Based on this assumption and the importance of tourism activity in the world and Brazilian economies and the relationship between sport mega events and the warming of this activity, the objective of this thesis was to verify the image reciprocal effects between a sport mega event host city and the national tourist destination (mother-destination). The focus was the 2016 Olympic Games held in Rio de Janeiro- Brazil. Descriptive/quantitative research was performed with foreigners from 48 countries (n = 340) using structured questionnaires and a Likert seven-point scale. The scale was adapted based on the cognitive and affective destination image dimensions, having as moderating variables: familiarity and the animosity with the mother-destination and games involvement. For data analysis, PLS structural equations modeling was performed using the software SmartPLS 3. The results pointed to positive evaluations of Rio and Brazil destination images, identifying the cognitive dimension as the most relevant. A positive and strong reciprocal effect was confirmed between the images of Rio as the 2016 Olympics host city and Brazil as the mother-destination. However, no moderation effects were found and in the specific case of animosity, there was no presence of this variable related to Brazil, which was a good result. This work brings theoretical contributions because it studies the reciprocal effects in destination images, considering the context of a sport mega event, as well as practical contributions for the development of more integrative tourism policies between mother-destination, cities / regions and for the hosting of new major events.

Markov processes have been widely studied and used for modeling problems. A Markov process has two main components (i.e., an evolution law and an initial distribution). Markov processes are not suitable for modeling some problems, for example, the problem of predicting a trajectory with a known destination. Such a problem has three main components: an origin, an evolution law, and a destination. The conditionally Markov (CM) process is a powerful mathematical tool for generalizing the Markov process. One class of CM processes, called $CM_L$, fits the above components of trajectories with a destination. The CM process combines the Markov property and conditioning. The CM process has various classes that are more general and powerful than the Markov process, are useful for modeling various problems, and possess many Markov-like attractive properties. Reciprocal processes were introduced in connection to a problem in quantum mechanics and have been studied for years. But the existing viewpoint for studying reciprocal processes is not revealing and may lead to complicated results which are not necessarily easy to apply. We define and study various classes of Gaussian CM sequences, obtain their models and characterizations, study their relationships, demonstrate their applications, and provide general guidelines for applying Gaussian CM sequences. We develop various results about Gaussian CM sequences to provide a foundation and tools for general application of Gaussian CM sequences including trajectory modeling and prediction. We initiate the CM viewpoint to study reciprocal processes, demonstrate its significance, obtain simple and easy to apply results for Gaussian reciprocal sequences, and recommend studying reciprocal processes from the CM viewpoint. For example, we present a relationship between CM and reciprocal processes that provides a foundation for studying reciprocal processes from the CM viewpoint. Then, we obtain a model for nonsingular Gaussian reciprocal sequences with white dynamic noise, which is easy to apply. Also, this model is extended to the case of singular sequences and its application is demonstrated. A model for singular sequences has not been possible for years based on the existing viewpoint for studying reciprocal processes. This demonstrates the significance of studying reciprocal processes from the CM viewpoint.

L’objectif de ces travaux est pour d’apporter des solutions innovantes à la réalisation de dispositifs passifs performants et compacts, susceptibles d’intéresser les concepteurs de circuits RF et millimétriques. Ces dispositifs sont basés notamment sur des lignes microrubans à ondes lentes sur substrat structuré, que cela soit sur PCB avec des vias borgnes pour la RF, ou nanostructurés sur membranes à nanofils pour le millimétrique. Les travaux complets comprennent (i) une analyse de la topologie, (ii) un développement du modèle équivalent validée par des simulations électromagnétiques (HFSSTM) et des mesures sur PCB et sur des membranes brésiliennes en millimétrique, (iii) des abaques de conceptions et (iv) des applications à la conception des nouveaux dispositifs passifs miniaturisés. Notre lignes offrent une grande souplesse de conception et peuvent être placées indifféremment sur le substrat structuré sans modification de leurs paramètres électriques. Un nouveau coupleur hybride miniaturisé par l’utilisation de cette ligne est présenté comme une preuve de concept. Pour aller plus loin, une étude comparable des structures de lignes microrubans couplées à ondes lentes est développée. Le principe du couplage sur substrat structuré est d’abord exposé avec une présentation de ses avantages et inconvénients, puis un modèle est également proposé dans le but de réaliser un coupleur co-directif 0-dB miniaturisé par l’utilisation de ces lignes. De plus, un des parties essentielles de ces travaux concerne l’utilisation de la structure microruban à onde lente pour la miniaturisation de dispositifs passifs non-réciproques : un nouvel isolateur microruban compact avec l’introduction de vias dans le ferrite et une nouvelle conception de circulateur miniaturisé sur le substrat ferrite-diélectrique avec un réseau de vias borgnes. / This work focuses on providing innovate solutions into the realization of high-quality and compact passive devices for designer on RF and millimeter-wave bands. These devices are based on slow-wave microstrip lines on structured substrate, either on PCB with blind vias for RF applications, or on metallic nanowire membrane. The complete works include (i) an analysis of topology, (ii) a development of equivalent model validated by the electromagnetic simulations (HFSSTM) and the measurements, (iii) design charts and (iv) applications on design of novel miniaturized passive devices. These transmission lines give the flexibility for designers and capability to be indifferently placed on structured substrate without any impact on their electrical parameters. A novel miniaturized hybrid coupler using this line is proposed, as a proof of concept. In the other hand, a comparable study on the structure of slow-wave coupled microstrip lines is developed. The principal of coupling on structured substrate is shown for their advantages and drawbacks and then an electrical model is also proposed in order to realize a miniaturized 0-dB forward-wave directional coupler using these lines. Moreover, an essential part of this thesis concerns the utilization of the slow-wave microstrip structure to miniaturize the non-reciprocal passive devices: a novel microstrip isolator with the introduction of vias inside the ferrite and a novel design of the miniaturized circulator on a ferrite-dielectric substrate with blind vias.

L’objectif de cette thèse est d’explorer de nouvelles technologies permettant de faciliter l’intégration des isolateurs dans les chaînes radiofréquences de satellites. Ces composants sont utilisés pour contrôler l’adaptation des amplificateurs dans les sections d’entrée et de sortie des équipements RF bas niveaux. Nous proposons deux voies de réalisation de ces isolateurs. Une première voie basée sur l’utilisation de matériaux ferricomposites est étudiée pour concevoir des composants en bande Ku. Une deuxième voie, basée sur l’utilisation d’hexaferrites de strontium et de baryum préorientés, a été étudiée pour concevoir des composants auto-polarisés (sans aimants) en bandes Q et Ka. / The goal of this PhD thesis is to explore new technologies that make possible to improve the integration of isolators in radiofrequency chain of satellites. These components are especially used to control matching of amplifiers.We propose two ways of producing these isolators. At first, ferricomposite materials are studied to design low-cost isolators at Kuband.Then, we studied pre-oriented strontium or barium hexaferrites to design self-biased components (without magnets) for Q and Ka band frequencies.