Dissertação (mestrado)—Universidade de Brasília, Faculdade de Planaltina, Programa de Pós-Graduação em Ciência de Materiais, 2013. / Submitted by Alaíde Gonçalves dos Santos (alaide@unb.br) on 2013-08-09T12:30:10Z No. of bitstreams: 1 2013_AlineGonçalvesdeSiqueira.pdf: 1697565 bytes, checksum: fa4b3b53e13fcce316062af5fbf416bc (MD5) / Approved for entry into archive by Guimaraes Jacqueline(jacqueline.guimaraes@bce.unb.br) on 2013-08-12T13:42:06Z (GMT) No. of bitstreams: 1 2013_AlineGonçalvesdeSiqueira.pdf: 1697565 bytes, checksum: fa4b3b53e13fcce316062af5fbf416bc (MD5) / Made available in DSpace on 2013-08-12T13:42:06Z (GMT). No. of bitstreams: 1 2013_AlineGonçalvesdeSiqueira.pdf: 1697565 bytes, checksum: fa4b3b53e13fcce316062af5fbf416bc (MD5) / O rio Madeira afluente da margem direita do rio Amazonas, possui extensão total de aproximadamente 3240 Km. Caracteriza por extensos gradientes que podem ser de natureza hidrológica, tectônica/geomorfológica, hidráulica e de transporte de sedimentos. Logo, apresenta características predominantes de rios de planalto e de planície. As suas oscilações fluviais influenciam a coloração da água, predominância de águas claras e escuras o que determinam as características químicas no rio. O objetivo do presente estudo foi avaliar os níveis basais do estoque de mercúrio no sedimento associado às propriedades físicas e químicas dos materiais que compõem este compartimento ambiental da área de influência da Usina Hidrelétrica – Jirau na bacia hidrográfica do rio Madeira – RO. As coletas foram em cinco pontos de amostragem nos tributários e calha do rio Madeira em perfis sedimentológicos (superfície, 10, 20, 40, 60 e 80 cm) nas regiões de águas claras (Abuña, Caiçara e Madeira) e águas escuras (Castanho e Mutum). Os dados indicam predominância granulométrica de sedimentos finos (silte) e partículas maiores (areia). Os espectros na região do infravermelho mostram bandas de absorção na região de 3700 cm-1 e 3621 cm-1 associadas às ligações OH existentes em hidróxidos de alumínio (Al-OH), bandas localizadas em 1100 cm-1 associadas às vibrações do tipo (O-Al-OH) e banda de absorção de 1033 cm-1 associadas à ligação (Si-O) características de argilominerais. Na região do rio Mutum-Paraná, característica de água escura, foi encontrada as maiores porcentagens de matéria orgânica (10,24 + 1,93%), carbono orgânico (3,13 + 0,26%), razão carbono/nitrogênio (67,21) e concentração de mercúrio (241,54 + 124,53 ?g kg-1). Em média as maiores concentrações de matéria orgânica, carbono orgânico, nitrogênio, razão carbono/nitrogênio e concentração de mercúrio total foram apresentados no intervalo entre a superfície e 10 cm de profundidade. A concentração de mercúrio nos perfis de sedimentos da bacia rio Madeira foram de 37 a 219 µg kg-1. As concentrações de mercúrio ficaram abaixo dos níveis preconizados pela Resolução 344/2004, não evidenciando pontos de contaminação na área de influência do aproveitamento hidrelétrico Jirau. A análise estatística de correlação das características do material ambiental com o estoque de mercúrio total indicou que o carbono orgânico total teve a maior correlação (73 %), seguido da razão carbono/nitrogênio (71%). _______________________________________________________________________________________ ABSTRACT / The Madeira River, a tributary on the right bank of the Amazon river, presents along its route (3,240 km) extensive gradients, which can be of a hydrological nature, tectonic / geomorphic, hydraulic and of sediment transport. The river has also predominant characteristics of upland rivers and plains. Fluvial oscillations influence the color of the river water, which may be clear and dark, and which determine the chemical characteristics of the river. The aim of this study was to evaluate baseline levels of mercury in the sediment associated with the physical and chemical properties of the materials that make up this environmental compartment under the influence of the HPP (Hydroelectric Power Plant) Jirau, situated in the hydrographic basin of the Madeira river, Rondônia, Brazil. Samples were collected at five points of tributaries and the riverbed sediment profiles in Madeira river profiles (surface, 10, 20, 40, 60 and 80 cm) encompassing regions of clear water (Abuña, Caiçara e Madeira) and dark water (Castanho e Mutum). The parameters analyzed indicate predominance of fine sediments (silt) and larger particles (sand). The spectra in the infrared region showed absorption bands in the region of 3700 cm-1 and 3621 cm-1 associated with OH bonds in aluminum hydroxides (Al-OH), bands located at 1100 cm-1 associated with vibrations of the type (O-Al-OH) and absorption band of 1033 cm-1 associated with (Si-O) bonds, characteristic of clay minerals. In the region of the Mutum-Paraná river, characteristic of dark water, higher percentages were observed for organic matter (10.24 + 1.93%), organic carbon (3.13 + 0.26%), carbon / nitrogen ratios (67.21) and mercury concentration (241.54 + 124.53 µg.kg-1). In factor profile, on average the highest concentrations of organic matter, organic carbon, nitrogen, carbon / nitrogen and total mercury concentration were observed in the range between the surface and 10 cm depth. Mercury concentrations were below the levels recommended by Resolution 344/2004, not evidencing contamination points in the area of influence of HPP Jirau. The statistical analysis of correlation of characteristics of environmental material with the stock total mercury indicated that total organic carbon had the highest correlation (73%), followed by the ratio of carbon / nitrogen (71%).

Tese (doutorado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Florestal, Programa de Pós-Graduação em Ciências Florestais, 2016. / Submitted by Fernanda Percia França (fernandafranca@bce.unb.br) on 2016-09-21T20:00:44Z No. of bitstreams: 1 2016_ArnoldoMarcílioGonçalvesdosSantos.pdf: 2455780 bytes, checksum: 6d43c13b926dd47d8034462025135333 (MD5) / Approved for entry into archive by Raquel Viana(raquelviana@bce.unb.br) on 2016-12-01T16:39:20Z (GMT) No. of bitstreams: 1 2016_ArnoldoMarcílioGonçalvesdosSantos.pdf: 2455780 bytes, checksum: 6d43c13b926dd47d8034462025135333 (MD5) / Made available in DSpace on 2016-12-01T16:39:20Z (GMT). No. of bitstreams: 1 2016_ArnoldoMarcílioGonçalvesdosSantos.pdf: 2455780 bytes, checksum: 6d43c13b926dd47d8034462025135333 (MD5) / A definição do uso e do manejo sustentável dos solos depende de suas propriedades físicas, químicas e biológicas. O monitoramento de mudanças nessas propriedades permite a avaliação de alterações na qualidade do solo. Este trabalho, realizado no Campo Experimental Confiança - Embrapa - RR, teve por finalidade avaliar o efeito dos diversos sistemas de uso da terra, implantados na região de floresta, no estado de Roraima, nas variáveis físicas, químicas e biológicas do solo, tendo a floresta nativa como testemunha. Foram avaliados solos de oito sistemas de uso da terra, coletados em parcelas de 50 x 50 m em áreas de Floresta nativa (FLO), Capoeira (CAP), Floresta Plantada com Acacia mangium (SFP), Sistema Agroflorestal com Baixo Insumo (SA1), Sistema Agroflorestal com Alto Insumo (SA2), Pastagem Manejada (PA1), Pastagem Alterada (PA2) e Cultivo de Pupunha (PUP). Para coleta das amostras de solo, foi estabelecido, em cada parcela, um transecto na diagonal do terreno onde foram determinados quatro pontos amostrais distante 10 m um do outro ao longo do transecto. Em cada ponto, o solo foi coletado com um trado, nas profundidades de 0 - 5 cm, 5 - 10 cm, 10 - 20 cm, 20 - 30 cm, 30 - 40 cm e 40 - 60 cm, no período de outubro de 2013 a junho de 2014. Determinaram-se, em cada amostra: densidade, porosidade, textura, pH; teores de N, P, K+, Ca2+, Mg2+, Al3+, C, MO e calcularam-se: acidez potencial, capacidade de troca catiônica efetiva, saturação por bases e saturação por alumínio. Outras cinco amostras foram para as análises biológicas nos mesmos transectos, distante oito metros uma da outra, nos meses de janeiro e agosto de 2014, que correspondem às estações seca e chuvosa na região, respectivamente. As amostras para análises biológicas (solo e serapilheira) foram coletadas com o com auxílio de uma sonda de 7 x 7 cm, introduzida no solo a 5 cm de profundidade. A mesofauna foi separada do solo utilizando-se funil de Berlese-Tullgren. Os dados das análises físicas e químicas foram submetidos à análise de variância, e as médias foram comparadas pelo teste de Scott-Knott a 5% de probabilidade. A mesofauna foi separada em grupos taxonômicos e foram calculados os índices de diversidade de Shannon e de uniformidade de Pielou. As principais variáveis foram submetidas à análise de componentes principais, complementada com análise de agrupamento. Para todas as variáveis estudadas, as maiores variações foram observadas na camada superficial do solo. A densidade e a porosidade tiveram comportamento inverso com menores densidades nas camadas superficiais (0 - 5 e 5 – 10 cm), e com aumento da densidade à medida que se aumenta a profundidade dos solos, sob o efeito do teor mais elevado da matéria orgânica. Não se observaram diferenças na textura dos solos nas diferentes profundidades e tratamentos. O solo sob PA2, em decorrência do intenso pisoteio do gado, apresentou a maior densidade entre os solos dos sistemas de uso da terra estudados. Para os sistemas de pastagem na região, a densidade e a porosidade do solo, variáveis diretamente relacionadas, representaram bons indicadores de qualidade. As diferenças nos teores de nutrientes, observadas entre os sistemas de uso da terra, foram decorrentes da incorporação de nutrientes, via adubação mineral, ou à adição de matéria orgânica. O SA1 apresentou baixos teores de nutrientes, que podem ser limitantes para a produção sustentável. O pousio, realizado na PA1, não foi suficiente para diferenciá-lo em relação aos teores de nutrientes no solo da PA2. A mesofauna do solo apresentou alta diversidade de ordens entre os solos dos diferentes sistemas de uso da terra, com destaque ao solo sob PUP, que apresentou a maior diversidade e quantidade. A diversidade da mesofauna é uma variável que pode, potencialmente, diagnosticar a qualidade do solo. A comunidade da mesofauna mostrou-se sensível ao manejo da vegetação, com aumento progressivo da densidade de alguns grupos em relação aos estádios sucessionais. A época da coleta afetou a densidade, a distribuição espacial e a riqueza média da mesofauna tanto na estação seca quanto na chuvosa. A diversidade total da fauna foi similar nos solos sob os sistemas de usos da terra estudados; no entanto, a frequência e a diversidade de Collembola são potenciais bioindicadores da qualidade dos solos pela diversidade de espécie coletadas e suas atividades funcionais. As análises de componentes principais e de agrupamento permitiram formar três grupos de sistemas de uso do solo: sistemas florestais (FLO, CAP e SFP); sistemas agrícolas ou agroflorestais (PUP, SA1 e SA2) e pastagens (PA1 e PA2) com afinidades nas variáveis físicas, químicas e biológicas. A CAP, em estágio avançado de recuperação, assemelha-se a FLO, indicando a importância do pousio para a recuperação do solo em sistemas de produção na região. A SFP, com Acacia mangium, requer cuidados na estrutura ecológica do sistema com indícios de mal manejado com perda da diversidade. Os sistemas agrícolas ou agroflorestais agropecuários não são sustentáveis e necessitam adições regulares de corretivos de acidez e adubação. Os sistemas com pastagens (PA1 e PA2), apesar de serem os mais comuns na região, também não se mostraram sustentáveis, mesmo no sistema manejado, com solos baixo nível nutricional para suporte de pastagem com carga animal. ___________________________________________________________________________________________________ ABSTRACT / Soils use and sustainable management depends on their physical, chemical and biological properties. Monitoring changes in these properties enables the soil quality assessment. The present work conducted at Campo Experimental Confiança - Embrapa - RR, aims to evaluate the effect of the different land use systems, in the state of Roraima, on the physical, chemical and biological soil variables, compared to the natural forest.. We evaluated soils samples collected in 50 x 50 m plots from eight different land use systems: Native Forest area (FLO), Secondary Forest (CAP), Planted Forest (SFP), Low Input Agroforestry System (SA1), High Input Agroforestry System (SA2), Managed Pasture (PA1), Degraded Pasture (PA2) and Pupunha heart cultivation (PUP). A diagonal transect was established in each plot, where four soil samples were collected. An auger was utilized at each site to collect soil samples from 0 - 5 cm, 5 - 10 cm, 10 - 20 cm, 20 - 30 cm, 30 - 40 cm and 40 - 60 cm deep, from October 2013 to June 2014. In each sample we determined: density, porosity, texture, pH, N, P, K+, Ca2+, Mg2+, , Al3+, C, , MO contents and calculated: potential acidity, effective CTC, saturation by bases and saturation by aluminum. Five other samples were for biological analysis in the same transect, eight meters apart from each other, in January and August 2014, which corresponded to the dry and rainy seasons, respectively. The samples for biological analyses (soil and litter) were collected with the aid of a 7 x 7 cm probe, introduced 5 cm deep into the soil. The mesofauna was separated from the soil utilizing a Berlese-Tullgren funnel. Physical and chemical analyses data were submitted to analysis of variance and means were compared by Scott-Knott test at 5 % probability. The mesofauna was separated into taxonomic groups and Shannon diversity and Pielou uniformity indexes calculated. The main variables were submitted to main components analysis, complemented with cluster analysis. The soil surface layer exhibited the highest values of the studied variables. The density and porosity have opposite behavior at lower densities in the surface layer (0 - 5, and a 5 - 10) and increased with increasing depth of the soil, due to its higher organic matter content. Distinct depths and treatments showed no soil texture differences. The soil under PA2, presented the highest density amongst the studied land use systems, due to the intense cattle trampling. The directly related variables, soil density and porosity, showed to be good quality indicators for the region’s grazing systems. The nutrient concentration differences observed among land use systems were due the nutrients incorporation, via mineral fertilizer or the addition of organic matter. The SA1 presented low nutrient concentration which may be limiting for sustainable production. The fallow held in PA1, showed not to be enough to differentiate it from PA2 in regards to the nutrient content in the soil. Soil mesofauna showed high order diversity between different land use systems soils, especially the one under PUP with the highest diversity and quantity. Mesofauna diversity shows to be a variable that can, potentially, diagnose the quality of the soil. The mesofauna community showed to be sensitive to vegetation management, progressively increasing the density of some groups in relation to successional stages. Collecting time affected mesofauna density, distribution and mean richness both in dry and rainy season. Total fauna diversity was similar in soils under the studied land use systems, however, Collembola frequency and diversity are potential soil quality bioindicators on account of the collected species diversity and functional activities. Cluster and key components analyses enabled us to form three groups of land use systems: forestry systems (FLO, CAP and SFP); agricultural or agroforestry systems (PUP, SA1 and SA2) and pastures (PA1 and PA2) with physical, chemical and biological variables affinities. CAP at an advanced stage of recovery resembles forestry systems to FLO indicating the fallow’s importance for the soil recovery in the production systems in the region. SFP, with Acacia mangium, requires cares to be taken with the ecological structure of the system, which exhibits diversity loss due to have evidence of badly management. The systems with agriculture or agroforestry and cattle raising are not sustainable and need limestone and chemical fertilizers additions. Systems with pastures (PA1 and PA2), despite being the most common ones in the region, showed not to be sustainable either, even in the managed system with low nutritional-level soils to raise healthy animals.

Dissertação (mestrado)—Universidade de Brasília, Instituto de Relações Internacionais, Programa de Pós-Graduação em Relações Internacionais, 2015. / Submitted by Albânia Cézar de Melo (albania@bce.unb.br) on 2015-10-28T15:13:17Z No. of bitstreams: 1 2015_MarianaFreitasMontebugnoli.pdf: 1675253 bytes, checksum: 5c09544a130abe30c126ce76bfa047e9 (MD5) / Approved for entry into archive by Raquel Viana(raquelviana@bce.unb.br) on 2016-01-26T20:05:58Z (GMT) No. of bitstreams: 1 2015_MarianaFreitasMontebugnoli.pdf: 1675253 bytes, checksum: 5c09544a130abe30c126ce76bfa047e9 (MD5) / Made available in DSpace on 2016-01-26T20:05:58Z (GMT). No. of bitstreams: 1 2015_MarianaFreitasMontebugnoli.pdf: 1675253 bytes, checksum: 5c09544a130abe30c126ce76bfa047e9 (MD5) / Este trabalho tem por finalidade o estudo do ativismo transnacional e, mais especificadamente, das redes de advocacy formadas em torno dos projetos de desenvolvimento regional em Rondônia, o POLONOROESTE (1981-1989) e o PLANAFLORO (1992-2002). Com a importância crescente atribuída aos atores da sociedade civil no cenário internacional, as redes de advocacy têm tido uma participação cada vez mais ativa nesse espaço, inclusive, operando nos processos de definição das normas internacionais. Devido à complexidade de suas problemáticas, as questões ambientais têm recebido especial atenção desses atores. As campanhas socioambientais que iremos abordar ao longo desse trabalho se inserem no contexto mais abrangente de mobilização global iniciada por organizações não governamentais (ONGs) ambientalistas junto aos Bancos Multilaterais de Desenvolvimentos (BMDs), na década de 1980, com o objetivo primário de promover reformas de cunho social e ambiental nessas instituições. O objetivo central dessa pesquisa consiste em descrever e analisar as dinâmicas e interações das redes de advocacy formadas em torno desses dois projetos, ressaltando como a dimensão transnacional interferiu nessas relações. A principal contribuição desse trabalho consiste em evidenciar, através da análise desses casos, alguns dos processos inerentes a essa via de participação da sociedade civil na governança internacional, apontando os desafios e as possibilidades que envolvem a formação de coalizões transnacionais. Utilizamos a abordagem das Redes Transnacionais como marco analítico e procuramos responder as problemáticas de pesquisa através do processo de inferência descritiva. / This research aims the study of transnational activism, and in particular the advocacy networks formed around the two regional development projects in Rondonia – POLONOROESTE (1981-1989) and PLANAFLORO (1992-2002). Through the increasing importance of civil society actors on the international arena, the advocacy networks participation have become progressively active in this space, including their activities in setting international norms. Because of their complexity, environmental issues have received special attention of these actors. The social-environmental campaigns that we will address in this work are inserted in a broader context of global mobilization, started in the 1980s by environmental non-governmental organizations (NGOs) against the Multilateral Development Banks (MDBs), with the primary purpose to promote social and environmental reforms in these institutions. The central purpose of this research is to describe and analyze the dynamics and interactions of advocacy networks formed around the two projects mentioned above, highlighting the influence of the transnational dimension on these relations. Through the analysis of these cases, the present study emphasizes some of the process involved in civil society participation in international governance, pointing out the inherent challenges and possibilities in the formation of transnational coalitions. We used the Transnational Network approach as analytical framework and tried to answer the research questions by the process of descriptive inference.

No description available.

Forecasting rainfall is of great importance for the farmers in West Africa. However, due too lack of reliable weather observations, rainfall forecats in West Africa are difficult and primarly based on satellite observations. This thesis will study a satellite dataset that could possible work as a substitute for weather balloon soundings and thus improving the rainfall forecasts. A satellite dataset with atmospheric temperature and humidity profiles, obtained from GPS-RO, was compared with radiosondes available from Abidjan, Bamako and Niamey, to study the potential of improving rainfall forecasts over West Africa. Two case studies with simulated weather forecasts with and without assimilated GPS-RO data was also compared. Data assimilation is used to produce an estimate of the atmospheric properties. Temperature profiles obtained from GPS-RO data showed insignificant bias compared to the radiosondes. Probable humidity sensor failure resulted in problem analysing the dew point temperature. From simulations, it was shown that GPS-RO assimilation may have a large impact on the forecasts and could potentially be a substitute for radiosondes in West Africa. / Regnprognoser är något som är viktigt för jordbrukare. I Västafrika saknas pålitliga väderobservationer och regnprognoser är istället baserade på satellit observationer. Denna uppsats riktar sig på att studera ett satellit dataset som har möjligheten att vara ett substitut för väderballongssonderingar och på så vis vara ett steg mot förbättrade regnprognoser. Ett dataset med atmosfäriska temperatur- och fuktighetsprofiler, erhållen från GPS-RO, jämfördes med radiosonderingar från Abidjan, Bamako och Niamey, för att studera dess potential för förbättrade regnprognoser över Västafrika. Två fallstudier med simulerade väderprognoser med och utan assimilerad GPS-RO data jämfördes också. Data assimilering används för att uppskatta de atmosfäriska egenskaperna. Temperaturprofilerna erhållna från GPS-RO data visade ingen signifikant skillnad jämfört med radiosonderingarna. Troligt sensorfel i fuktighetsgivarna från radiosonderingarna ledde till problem med analysen av daggpunktstemperaturen. Simuleringar visade att assimilation med GPS-RO kan ha stor påverkan på prognoserna och har potential att bli ett substitut för radiosonderingar i Västafrika.

According to the Department of Water Affairs (DWAF, 2004 p.15), South Africa’s water resources are scarce and extremely limited and much of this precious resource is utilised and consumed in our industries. Treatment and re-use of effluent generated is, in some cases, preferred over use of alternate water resources (Du Plessis, 2008 p.3). The volume of effluent generated in treatment processes like ultra-filtration (UF) and reverse osmosis (RO) units is determined by the feed water quality, with high water loss through effluent generation at poor feed water quality. Current UF and RO applications require an increased UF production capacity due to the use of UF filtrate for periodic backwashing of the UF membrane units. This results in loss of water and decreases overall recovery. The need therefore exists to increase the overall recovery of product water from the raw water stream by reducing the amount of effluent generated. This would be possible to achieve by using RO brine to backwash the UF unit. The study was conducted to provide a modelling tool, assisting management to optimise the use of RO brine as backwash water on the UF system at the Medupi power station. The secondary objective of this study was the development of a modelling tool that can be used for other projects, new or existing, as a measure and indication of the usability of RO brine as backwash water on UF systems. By successfully applying this newly developed model, the viability of utilising the RO brine as backwash water for the UF was investigated. This modification would lead to utilizing smaller UF units than previously envisioned, which in turn leads to reducing capital cost with 11.07% and operating expenditure with 9.98% at the Medupi power station. This also has a positive environmental impact by reducing the amount of raw water used monthly by 10.34% (108 000 m3/month). / MIng (Development and Management Engineering), North-West University, Potchefstroom Campus, 2014

According to the Department of Water Affairs (DWAF, 2004 p.15), South Africa’s water resources are scarce and extremely limited and much of this precious resource is utilised and consumed in our industries. Treatment and re-use of effluent generated is, in some cases, preferred over use of alternate water resources (Du Plessis, 2008 p.3). The volume of effluent generated in treatment processes like ultra-filtration (UF) and reverse osmosis (RO) units is determined by the feed water quality, with high water loss through effluent generation at poor feed water quality. Current UF and RO applications require an increased UF production capacity due to the use of UF filtrate for periodic backwashing of the UF membrane units. This results in loss of water and decreases overall recovery. The need therefore exists to increase the overall recovery of product water from the raw water stream by reducing the amount of effluent generated. This would be possible to achieve by using RO brine to backwash the UF unit. The study was conducted to provide a modelling tool, assisting management to optimise the use of RO brine as backwash water on the UF system at the Medupi power station. The secondary objective of this study was the development of a modelling tool that can be used for other projects, new or existing, as a measure and indication of the usability of RO brine as backwash water on UF systems. By successfully applying this newly developed model, the viability of utilising the RO brine as backwash water for the UF was investigated. This modification would lead to utilizing smaller UF units than previously envisioned, which in turn leads to reducing capital cost with 11.07% and operating expenditure with 9.98% at the Medupi power station. This also has a positive environmental impact by reducing the amount of raw water used monthly by 10.34% (108 000 m3/month). / MIng (Development and Management Engineering), North-West University, Potchefstroom Campus, 2014

Le déploiement à grande échelle de l’internet des objets nécessite le développement de systèmes de radiocommunication plus économes en énergie, dont le circuit de génération de fréquences est connu pour être particulièrement énergivore. L’objectif de ce travail de thèse est donc d’une part de développer une synthèse de fréquences très faible consommation et d’autre part de démontrer les performances de la technologie FDSOI pour des applications analogiques et radiofréquences. Dans le premier chapitre sont présentées les spécifications du standard choisi -le BLE-, les spécificités de la technologie FDSOI et l'état de l’art des architectures de transmetteurs radiofréquences à faible consommation. Nous avons retenue de cette comparaison l'architecture à division par phases. Le deuxième chapitre présente les résultats de trois types de modélisation système de l’architecture ; 1 - le fonctionnement de ses composants et les points clés à respecter pour son implémentation, 2 - le comportement en bruit de phase pour la définition des spécifications, et 3 - l’impact de l’architecture sur la génération de raies spectrales parasites. Cette étude nous a permis de fixer le cahier des charges du VCRO développé au chapitre suivant. Le troisième chapitre est consacré à la conception, la réalisation et le test de 4 topologies de VCROs en technologie FDSOI 28nm et d'un circuit de test. Les premiers résultats de mesure sont encourageants mais nécessitent d’être complétés par des mesures avec PLL fractionnaire intégrée. En effet, la sensibilité des circuits à la tension d’alimentation (pushing de l’ordre de 5 GHz/V) a rendu les mesures du bruit de phase très délicates. / The large-scale deployment of IoT requires the development of more efficient energy radio systems, within which the frequency generation circuit is known to be particularly energy-consuming. The objective of this thesis is firstly to develop a very low consumption frequency synthesis and secondly to demonstrate the performance of the FDSOI technology for analog and RF applications.In the first chapter are the specifications of the chosen standard -the BLE-, the specifications of the FDSOI technology and state of the art of low power radio frequency synthesizers architecture. We have chosen from this comparison the Fractional Phase Divider architecture. The second chapter presents the results of three types of system simulations of the PLL; 1 - the operation of its components and the key points to be respected for its implementation, 2 - the phase noise behavior for the definition of specifications, and 3 - the impact of architecture on the generation of spurious. This study allowed us to set the specifications of VCROs developed in the next chapter. The third chapter is dedicated to the design, implementation and testing of four topologies of VCROs and a test circuit in FDSOI 28nm technology. The first measurement results are encouraging but they need to be complemented by an integrated fractional PLL measurement. Indeed, the sensitivity of the circuits to the supply voltage (pushing of about 5 GHz/V) made measurements of phase noise very delicate. The measured consumption is less than 0.8 mA and the surface of the circuits is of the order of 600 µm².In the fourth and final chapter we present the implementation at circuit-level of a phase synchronization PLL.

Submitted by Marcia Bacha (marcia.bacha@fgv.br) on 2011-05-20T19:11:06Z No. of bitstreams: 1 000078815.pdf: 2519059 bytes, checksum: b024fb3824e053c0bafbd611b950a14b (MD5) / Approved for entry into archive by Marcia Bacha(marcia.bacha@fgv.br) on 2011-05-20T19:12:17Z (GMT) No. of bitstreams: 1 000078815.pdf: 2519059 bytes, checksum: b024fb3824e053c0bafbd611b950a14b (MD5) / Approved for entry into archive by Marcia Bacha(marcia.bacha@fgv.br) on 2011-05-20T19:13:13Z (GMT) No. of bitstreams: 1 000078815.pdf: 2519059 bytes, checksum: b024fb3824e053c0bafbd611b950a14b (MD5) / Made available in DSpace on 2011-05-20T19:14:14Z (GMT). No. of bitstreams: 1 000078815.pdf: 2519059 bytes, checksum: b024fb3824e053c0bafbd611b950a14b (MD5) Previous issue date: 1996 / This work is the result of a field research carried out during the year of 1990 in Porto Velho - RO, with the assistence of agricultral experts and use secondary sources of information, aiming to get acquainted with Public Policy for agriculture in the state, to identify and to analyse the result of those policies and present suggestions for chenges considering the migration. The study describes and analyses the State Public Policies, presenting a historical vision of its economical farmation by reconstituting its past, fron the extractivistic stages and the present days. The economic evolution of Rondonis was analysed, and fact that the influence of the economic and social facts upon the migratory flows toward Porto Velho has been raising, proportionally from the very beginning of its history until the present days becarnse notorious. Problems resulting from the increasing urbanization of the cities, specially affected by the migration process of the rural population, and population' s troubles caused by the insuitable agricultural Policy has also been approached. I carne to the conclusion that the State Policy for agriculture IS not appropriate due to several reasons, which wiIl be pointed out in this work. Finally, suggestions are given to reformulate the State Policy for agriculture, to overcome some of the great problems concerning this matter which affects mainly the migrating population that come from rural areas to the urban surroundings. / o presente trabalho resulta de uma pesquisa de campo realizada na cidade de Porto Velho / RO, em 1990, junto a técnicos da área agrícola e da utilização de outras fontes de informações (secundárias), com o objetivo de conhecer as Políticas Públicas para o setor agrícola do Estado, identificar e analisar o seu resultado e apresentar sugestões para mudanças, considerando a população migrante. o estudo descreve e analisa as Políticas Públicas do Estado, apresenta uma visão histórica de sua formação econômica, fazendo uma reconstituição de seu passado das Fases do Extrativismo e Moderna. Analisamos a evolução de sua economia, ficando evidente que os fatos econômicos e sociais condicionaram o direcionamento de fluxos migratórios para Porto Velho, desde os seus primórdios, até hoje em proporções crescentes. Evidenciaram-se os problemas decorrentes da crescente urbanização das cidades afetadas pelo processo migratório, principalmente a população rural, as dificuldades encontradas por essa população, motivadas pela falta de políticas agrícolas adequadas. Constatou-se que as políticas agrícolas do Estado não estão sendo viáveis, face a diversos fatores, os quais são apontados no trabalho. Por fim, apontamos sugestões para uma proposta de reformulação da política para o Setor Agrícola, com vistas a superar grandes problemas na área, vividos principalmente pela população rural que migra para aquele Estado.

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia de Produção. / Made available in DSpace on 2012-10-18T22:24:01Z (GMT). No. of bitstreams: 1 226468.pdf: 588487 bytes, checksum: f0e6b91dd44fce1b631a2995bbfc5e6a (MD5)