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Com o surgimento dos métodos de controle sensorless, houve a necessidade da utilização de estimadores e/ou observadores de estados que lhe conferissem a robustez e precisão necessária no acionamento de motores de indução. Este trabalho trata da aplicação do Filtro de Kalman Estendido (EKF) na estimativa da velocidade e posição do rotor, visando a implementação da técnica de controle vetorial indireto em um sistema de controle de velocidade sensorless para motores de indução trifásicos. O desenvolvimento matemático das variáveis de estado do sistema associado ao processo estocástico do EKF é apresentado neste estudo, e apontam a sua aplicação em condições de velocidade e carga variáveis, as quais são impostas a estes motores no cotidiano. A estratégia de controle sensorless foi testada através de linhas de rotina no software Matlab®, simulando condições de operação deste tipo de motor, sendo comprovada a sua performance, assim como os tempos de convergência consistentes com os requisitos usuais dos sistemas de alto desempenho. As principais contribuições deste trabalho são o uso de um EKF de ordem reduzida (ROEKF) e o pré-ajuste das matrizes de covariância para agilizar a convergência nas estimativas de velocidade e posição para as futuras implementações em processadores de sinais digitais atualmente acessíveis.

With the emergence of sensorless control methods, there was a need for the use of estimators and/or state observers to give it the robustness and precision required in the drive of induction motors. This work deals with the application of the Extended Kalman Filter (EKF) in the estimation of rotor speed and position, aiming at the implementation of the indirect vector control technique in a sensorless speed control system for three-phase induction motors. The mathematical development of the system state variables associated with the EKF stochastic process is presented in this study, and point out its application under variable speed and load conditions, which are imposed on these motors in everyday life. The sensorless control strategy was tested through routine lines in the Matlab® software, simulating operating conditions of this type of engine, being proven its performance, as well as the convergence times consistent with the usual requirements of high performance systems. The main contributions of this work are the use of a reduced-order EKF (ROEKF) and the preset of covariance matrices to accelerate convergence in speed and position estimates for future implementations in currently accessible digital signal processors.

The CSEM method, which is frequently used as a risk-reduction tool in hydrocarbon exploration, is finally moving to a new frontier: reservoir monitoring and surveillance. In the present work, we present a CSEM time-lapse interpretation workflow. One essential aspect of our workflow is the demonstration of the linear relationship between the anomalous transverse resistance, an attribute extracted from CSEM data inversion, and the SoPhiH attribute, which is estimated from fluid-flow simulators. Consequently, it is possible to reliably estimate SoPhiH maps from CSEM time-lapse surveys using such a relationship. We demonstrate our workflow’s effectiveness in the mature Marlim oilfield by simulating the CSEM time-lapse response after 30 and 40 years of seawater injection and detecting the remaining sweet spots in the reservoir. The Marlim reservoirs are analogous to several turbidite reservoirs worldwide, which can also be appraised with the proposed workflow. The prediction of SoPhiH maps by using CSEM data inversion can significantly improve reservoir time-lapse characterization.

The release of phosphorus (P) stored in the sediment may cause long-term delay in the recovery of lakes, ponds, and lagoons from eutrophication. In this paper, we tested on a laboratory scale the efficacy of the flocculant polyaluminium chloride (PAC) and a strong P-binding agent (lanthanum-modified bentonite, LMB) on their ability to flocculate a cyanobacterial bloom and hamper P release from a hypertrophic, brackish lagoon sediment. In addition, critical P loading was estimated through PCLake. We showed that cyanobacteria could be effectively settled using a PAC dose of 2 mg Al L−1 combined with 400-mg L−1 LMB; PAC 8 mg Al L−1 alone could also remove cyanobacteria, although its performance was improved adding low concentrations of LMB. The efficacy of LMB to bind P released from the sediment was tested based on potentially available sediment P. A dose of 400 g LMB m−2 significantly reduced the P release from sediment to over-standing water (either deionized water or water from the lagoon with and without cyanobacteria). In sediment cores, LMB + PAC reduced sediment P flux from 9.9 (± 3.3) to − 4.6 (± 0.3) mg P m−2 day−1 for the experimental period of 3 months. The internal P load was 14 times higher than the estimated P critical load (0.7 mg P m−2 day−1), thus even if all the external P sources would be ceased, the water quality will not improve promptly. Hence, the combined LMB + PAC treatment seems a promising in-lake intervention to diminish internal P load bellow the critical load. Such intervention is able to speed up recovery in the brackish lagoon once external loading has been tackled and at a cost of less than 5% of the estimated dredging costs.

One of the main symptoms of eutrophication is the proliferation of phytoplankton biomass, including nuisance cyanobacteria. Reduction of the external nutrient load is essential to control eutrophication, and in-lake interventions are suggested for mitigating cyanobacterial blooms to accelerate ecosystem recovery. Floc & Sink (F&S) is one such intervention technique that consists of applying a low dose of coagulants in combination with ballasts for removing cyanobacteria biomass. It is especially suitable for deep lakes with an external nutrient load that is higher than the internal load and suffers from perennial cyanobacterial bloom events. Studies showing the efficacy of the F&S technique have been published, but those testing its variation in efficacy with changes in the environmental conditions are still scarce. Therefore, we evaluated the efficiency of the F&S technique to remove cyanobacteria from water samples collected monthly from two different sites in a deep tropical reservoir (Funil Reservoir, Brazil) in the laboratory. We tested the efficacy of two coagulants, chitosan (CHI) and poly-aluminum chloride (PAC), alone and in combination with lanthanum-modified bentonite (LMB) in settling phytoplankton biomass. We hypothesized that: ⅰ) the combined treatments are more effective in removing the algal biomass and ⅱ) the efficiency of F&S treatments varies spatially and monthly due to changes in environmental conditions. The combined treatments (PAC + LMB or CHI + LMB) removed up to seven times more biomass than single treatments (PAC, CHI, or LMB). Only the treatments CHI and LMB + CHI differed in efficiency between the sites, although all treatments showed significant variation in efficiency over the months at both the sampling sites. The combined treatments exhibited lower removal efficacy during the warm-rainy months (October–March) than during the mild-cold dry months (April–September). At high pH (pH > 10), the efficiency of the CHI and LMB + CHI treatments decreased. CHI had lower removal efficiency when single-cell cyanobacteria were abundant, while the combined treatments were equally efficient regardless of the morphology of the cyanobacteria. Hence, the combination of PAC as a coagulant with a ballast LMB is the most effective technique to precipitate cyanobacteria under the conditions that are encountered around the year in this tropical reservoir.

Combining coagulants with ballast (natural soil or modified clay) to remove cyanobacteria from the water column is a promising tool to mitigate nuisance blooms. Nevertheless, the possible effects of this technique on different toxin-producing cyanobacteria species have not been thoroughly investigated. This laboratory study evaluated the potential effects of the “Floc and Sink” technique on releasing microcystins (MC) from the precipitated biomass. A combined treatment of polyaluminium chloride (PAC) with lanthanum modified bentonite (LMB) and/or local red soil (LRS) was applied to the bloom material (mainly Dolichospermum circinalis and Microcystis aeruginosa) of a tropical reservoir. Intra and extracellular MC and biomass removal were evaluated. PAC alone was not efficient to remove the biomass, while PAC + LMB + LRS was the most efficient and removed 4.3–7.5 times more biomass than other treatments. Intracellular MC concentrations ranged between 12 and 2.180 µg L−1 independent from the biomass. PAC treatment increased extracellular MC concentrations from 3.5 to 6 times. However, when combined with ballast, extracellular MC was up to 4.2 times lower in the top of the test tubes. Nevertheless, PAC + LRS and PAC + LMB + LRS treatments showed extracellular MC concentration eight times higher than controls in the bottom. Our results showed that Floc and Sink appears to be more promising in removing cyanobacteria and extracellular MC from the water column than a sole coagulant (PAC).

Sensorless control methods stand out as an alternative for cost reduction and maintenance in AC electric drive systems. This work deals with the application of the Extended Kalman Filter (EKF) to the estimation of the speed and position of the rotor aiming at the implementation of the indirect vector control technique in a speed control system for three- phase induction motors. The Kalman lter, despite its mathematical and computational complexity, performs well under variable speed and load conditions as well as convergence times consistent with the usual requirements of high performance systems. The main contributions of this work are the use of a reduced-order EKF (ROEKF) and the co-variance matrix pretuning in order to accelerate the convergence in the velocity and position estimates for futureimplementations in digital signal processors currently accessible.

The responses of phytoplankton to the spatial variation of 2 tropical reservoirs with long water-residence times was studied by means of morphology-based functional groups (MBFGs). The groups were compared among the pelagic, tributary, and downstream zones to determine the spatial distribution and its main drivers. Based on the zonation concept, we hypothesized that phytoplankton tolerant to nutrient depletion would be more important in the pelagic zones, and phytoplankton resistant to light limitation and turbulence would be more important in the lotic zones. We also expected nutrients and/or light availability (bottom-up control) to be the main drivers of MBFGs spatiality in tropical systems. Our results indicated the importance of this control for phytoplankton spatial distribution. The phytoplankton biovolume was more homogeneous in Serra da Mesa Reservoir (SER), while in Três Marias Reservoir (TRM) biovolume was higher in the pelagic zone. MBFG III dominated in the pelagic zone of TRM while MBFG V dominated in its tributary. The higher biovolume of MBFG III was associated with low dissolved phosphate and high water temperature and pH in SER, and lower dissolved inorganic nitrogen and high pH in the pelagic zone of TRM, as shown by RDA analyses. The dominance of MBFG V in the tributary is probably a response to higher turbidity and dissolved organic carbon availability. We conclude that within zones, resources (nutrients and light availability), temperature, and pH were the main drivers of the phytoplankton in these reservoirs. Furthermore, the MBFG scheme can be used to monitor phytoplankton spatial distribution.

Dissertação (Mestrado) - Pontifícia Universidade Católica de Minas Gerais, Programa de Pós-Graduação em Engenharia Elétrica. Bibliografia: f. 74-77 Sistemas de controle de velocidade e/ou posição usando motores de indução trifásico sem sensores eletromecânicos (técnicas sensorless) proporcionam uma considerável redução de custos e manutenção, aumento da confiabilidade, da robustez e da imunidade a ruídos em relação ao controle de motores convencionais com sensores. Nesse contexto, pesquisas envolvendo estimadores e observadores de estados aplicados à estimação da velocidade e posição do motor, considerando as técnicas de controle vetorial sensorless e técnicas de estimação como o Filtro de Kalman Estendido e suas variantes encontram-se disponíveis na literatura técnico-científica, reforçando a importância das aplicações atuais. Este trabalho apresenta os estudos, desenvolvimento e resultados de uma simulação computacional, feita através de rotinas em ambiente MatLab, com a finalidade de avaliar o desempenho do Filtro de Kalman Estendido de 5ª ordem, com sintonia das matrizes de covariância pré-ajustadas de modo offline aplicado ao controle vetorial sensorless de um motor de indução. A rotina de simulação para estimação da velocidade e posição do rotor deste motor é testada sob condições de velocidade e carga mecânica variável. A partir das simulações realizadas, pôde-se demonstrar que as matrizes pré-ajustadas de modo offline auxiliam na sintonia do EKF e proporcionam melhoria de desempenho ao sistemas de controle de velocidade. Assim, concluiu-se sobre a viabilidade para futuras implementações práticas em dispositivos de Processamento Digital de Sinais existentes no mercado. Palavras-chave: Filtro de Kalman Estendido, Motor de indução, Acionamentos CA, Controle de Velocidade Sensorless. Speed and position control systems using three-phase induction motors without electromechanical sensors (sensorless techniques) provide considerable cost savings and maintenance, increased reliability, robustness and noise immunity over noise conventional sensor motor control. In this context, research involving state estimators and observers applied to motor speed and position estimation, considering sensorless vector control techniques and estimation techniques such as Extended Kalman Filter and its variants are available in the technical-scientific literature, reinforcing the importance of current applications. This work presents the studies, development and results of a computational simulation, performed through MatLab environment routines, with the purpose of evaluating the performance of the 5th order Extended Kalman Filter, with tuning of the matrices offline preset covariance matrices applied to the sensorless vector control of an induction motor. The simulation routine for estimating the rotor speed and position of this motor is tested under conditions of variable mechanical load and speed. From the simulations performed, it could be demonstrated that the offline preset matrices assist in tuning the EKF and provide performance improvement to the speed control systems. Thus, it was concluded about the feasibility for future practical implementations in existing Digital Signal Processing devices in the market. Keysords: Extend Kalman Filter, Three-Phase Induction Motor, Speed Control sensorless, Electric Drives CA.

Eutrophication is considered the most important water quality problem in freshwaters and coastal waters worldwide promoting frequent occurrence of blooms of potentially toxic cyanobacteria. Removal of cyanobacteria from the water column using a combination of coagulant and ballast is a promising technique for mitigation and an alternative to the use of algaecides. In laboratory, we tested experimentally the efficiency of two coagulants, polyaluminium chloride (PAC) and chitosan (made of shrimp shells), alone and combined with two ballasts: red soil (RS) and the own lagoon sediment, to remove natural populations of cyanobacteria, from an urban brackish coastal lagoon. PAC was a very effective coagulant when applied at low doses (≤8 mg Al L−1) and settled the cyanobacteria, while at high doses (≥16 mg Al L−1) large flocks aggregated in the top of test tubes. In contrast, chitosan was not able to form flocks, even in high doses (>16 mg L−1) and did not efficiently settle down cyanobacteria when combined with ballast. The RS itself removed 33--47 % of the cyanobacteria. This removal was strongly enhanced when combined with PAC in a dose-dependent matter; 8 mg Al L−1 was considered the best dose to be applied. The lagoon sediment alone did not promote any settling of cyanobacteria but removal was high when combined with PAC. Combined coagulant and ballast seems a very efficient, cheap, fast and safe curative measure to lessen the harmful cyanobacteria bloom nuisance in periods when particularly needed, such as around the 2016 Olympics in Jacarepaguá Lagoon.

We tested the hypothesis that a combination of coagulant and ballast could be efficient for removal of positively buoyant harmful cyanobacteria in shallow tropical waterbodies, and will not promote the release of cyanotoxins. This laboratory study examined the efficacy of coagulants [polyaluminium chloride (PAC) and chitosan (made of shrimp shells)] alone, and combined with ballast (lanthanum modified bentonite, red soil or gravel) to remove the natural populations of cyanobacteria collected from a shallow eutrophic urban reservoir with alternating blooms of Cylindrospermopsis and Microcystis. PAC combined with ballast was effective in settling blooms dominated by Microcystis or Cylindrospermopsis. Contrary to our expectation, chitosan combined with ballast was only effective in settling Cylindrospermopsis-dominated blooms at low pH, whereas at pH ≥ 8 no effective flocculation and settling could be evoked. Chitosan also had a detrimental effect on Cylindrospermopsis causing the release of saxitoxins. In contrast, no detrimental effect on Microcystis was observed and all coagulant-ballast treatments were effective in not only settling the Microcystis dominated bloom, but also lowering dissolved microcystin concentrations. Our data show that the best procedure for biomass reduction also depends on the dominant species.

Element cycling in aquatic systems is driven chiefly by planktonic processes, and the structure of the planktonic food web determines the efficiency of carbon transfer through trophic levels. However, few studies have comprehensively evaluated all planktonic food-web components in tropical regions. The aim of this study was to unravel the top-down controls (metazooplankton community structure), bottom-up controls (resource availability), and hydrologic (water residence time) and physical (temperature) variables that affect different components of the microbial food web (MFW) carbon stock in tropical reservoirs, through structural equation models (SEM). We conducted a field study in four deep Brazilian reservoirs (Balbina, Tucuruí, Três Marias, and Funil) with different trophic states (oligo-, meso-, and eutrophic). We found evidence of a high contribution of the MFW (up to 50% of total planktonic carbon), especially in the less-eutrophic reservoirs (Balbina and Tucuruí). Bottom-up and top-down effects assessed through SEM indicated negative interactions between soluble reactive phosphorus and phototrophic picoplankton (PPP), dissolved inorganic nitrogen, and heterotrophic nanoflagellates (HNF). Copepods positively affected ciliates, and cladocerans positively affected heterotrophic bacteria (HB) and PPP. Higher copepod/cladoceran ratios and an indirect positive effect of copepods on HB might strengthen HB-HNF coupling. We also found low values for the degree of uncoupling (D) and a low HNF/HB ratio compared with literature data (mostly from temperate regions). This study demonstrates the importance of evaluating the whole size spectrum (including microbial compartments) of the different planktonic compartments, in order to capture the complex carbon dynamics of tropical aquatic ecosystems.

Eutrophication often results in blooms of toxic cyanobacteria that hamper the use of lakes and reservoirs. In this paper, we experimentally evaluated the efficacy of a metal salt (poly-aluminium chloride, PAC) and chitosan, alone and combined with different doses of the lanthanum modified bentonite Phoslock® (LMB) or local red soil (LRS) to sediment positively buoyant cyanobacteria from Funil Reservoir, Brazil, (22°30′S, 44°45′W). We also tested the effect of calcium peroxide (CaO2) on suspended and settled cyanobacterial photosystem efficiency, and evaluated the soluble reactive P (SRP) adsorbing capacity of both LMB and LRS under oxic and anoxic conditions. Our data showed that buoyant cyanobacteria could be flocked and effectively precipitated using a combination of PAC or chitosan with LMB or LRS. The SRP sorption capacity of LMB was higher than that of LRS. The maximum P adsorption was lowered under anoxic conditions especially for LRS ballast. CaO2 addition impaired photosystem efficiency at 1 mg L−1 or higher and killed precipitated cyanobacteria at 4 mg L−1 or higher. A drawback was that oxygen production from the peroxide gave positive buoyancy again to the settled flocs. Therefore, further experimentations with slow release pellets are recommended.

Brazilian carbonate reservoirs contain huge oil-in-place volumes and are likely to have an important economic impact in global oil industry. Such carbonate reservoirs, both Albian and Aptian, are located offshore in deep water, which has an important role in development costs. In siliciclastic plays it is standard practice to use time-lapse (4D) seismic to locate wells in unswept areas, maximizing the recovery factor. However, in carbonate plays, time-lapse seismic monitoring remains challenging, with few cases of success published around the world. Carbonates differ from siliciclastic rocks in many aspects. With a varied chemical composition and complex pore connectivity, carbonates bring on a large diversity of facies, each one showing a specific seismic response. Moreover, the usually high incompressibility of the carbonate matrix reduces sensitivity to pressure and saturation changes, which are the main effects expected on a hydrocarbon field undergoing production. Considering both the economic relevance and the difficulties of using time-lapse seismic to monitor carbonate reservoirs, Petrobras created a strategic program to face this challenge, a time-lapse seismic (S4D) study of an Albian carbonate reservoir located in the Campos Basin offshore Brazil. Three legacy data were available: streamer–1987, streamer–2002, and ocean-bottom cable–2010. Extensive feasibility studies are performed as well as a meticulous prestack 4D simultaneous inversion based on the seismic data, preliminary cross-equalized to partially overcome the initial low repeatability. A multidisciplinary interpretation conducted by a team of geophysicists, geologists, and reservoir engineers finally lead to results overcoming expectations. Saturation and pressure changes are detected using P- and S-impedance attributes, consistent with production data. Results are opening perspectives for further monitoring other carbonate reservoirs, especially with new presalt Brazilian discoveries in the Campos and Santos Basins, which might have a huge economic impact.

Removal of cyanobacteria from the water column using a coagulant and a ballast compound is a promising technique to mitigate nuisance. As coagulant the organic, biodegradable polymer chitosan has been promoted. Results in this study show that elevated pH, as may be common during cyanobacterial blooms, as well as high alkalinity may hamper the coagulation of chitosan and thus impair its ability to effectively remove positively buoyant cyanobacteria from the water column. The underlying mechanism is likely a shielding of the protonated groups by anions. Inasmuch as there are many chitosan formulations, thorough testing of each chitosan prior to its application is essential. Results obtained in glass tubes were similar to those from standard jar tests demonstrating that glass tube tests can be used for testing effects of coagulants and ballasts in cyanobacteria removal whilst allowing far more replicates. There was no relation between zeta potential and precipitated cyanobacteria. Given the well-known antibacterial activity of chitosan and recent findings of anti-cyanobacterial effects, pre-application tests are needed to decipher if chitosan may cause cell leakage of cyanotoxins. Efficiency- and side-effect testing are crucial for water managers to determine if the selected approach can be used in tailor-made interventions to control cyanobacterial blooms and to mitigate eutrophication.

Combining coagulant and ballast to remove cyanobacteria from the water column is a promising restoration technique to mitigate cyanobacterial nuisance in surface waters. The organic, biodegradable polymer chitosan has been promoted as a coagulant and is viewed as non-toxic. In this study, we show that chitosan may rapidly compromise membrane integrity and kill certain cyanobacteria leading to release of cell contents in the water. A strain of Cylindrospermopsis raciborskii and one strain of Planktothrix agardhii were most sensitive. A 1.3 h exposure to a low dose of 0.5 mg l−1 chitosan already almost completely killed these cultures resulting in release of cell contents. After 24 h, reductions in PSII efficiencies of all cyanobacteria tested were observed. EC50 values varied from around 0.5 mg l−1 chitosan for the two sensitive strains, via about 5 mg l−1 chitosan for an Aphanizomenon flos-aquae strain, a toxic P. agardhii strain and two Anabaena cylindrica cultures, to more than 8 mg l−1 chitosan for a Microcystis aeruginosa strain and another A. flos-aquae strain. Differences in sensitivity to chitosan might be related to polymeric substances that surround cyanobacteria. Rapid lysis of toxic strains is likely and when chitosan flocking and sinking of cyanobacteria is considered in lake restoration, flocculation efficacy studies should be complemented with investigation on the effects of chitosan on the cyanobacteria assemblage being targeted.

Cyanobacteria blooms are a risk to environmental health and public safety due to the potent toxins certain cyanobacteria can produce. These nuisance organisms can be removed from water bodies by biomass flocculation and sedimentation. Here, we studied the efficacy of combinations of a low dose coagulant (poly-aluminium chloride-PAC-or chitosan) with different ballast compounds (red soil, bauxite, gravel, aluminium modified zeolite and lanthanum modified bentonite) to remove cyanobacterial biomass from water collected in Funil Reservoir (Brazil). We tested the effect of different cyanobacterial biomass concentrations on removal efficiency. We also examined if zeta potential was altered by treatments. Addition of low doses of PAC and chitosan (1±8 mg Al L-1) to the cyanobacterial suspensions caused flock formation, but did not settle the cyanobacteria. When those low dose coagulants were combined with ballast, effective settling in a dose-dependent way up to 99.7% removal of the flocks could be achieved without any effect on the zeta potential and thus without potential membrane damage. Removal efficacy was influenced by the cyanobacterial biomass and at higher biomass more ballast was needed to achieve good removal. The combined coagulant-ballast technique provides a promising alternative to algaecides in lakes, ponds and reservoirs.

A polemica entre imperialismo e ultraimperialismo marcou o debate marxista no comeco do seculo XX, sendo polarizada por Lenin e Kautski. Aparentemente, os acontecimentos do capitalismo contemporâneo demonstrariam que a tese ultraimperialista seria a vencedora, ja que as rivalidades entre as principais potencias nao seriam observadas no campo militar. Argumenta-se que esse aparente ultraimperialismo seria uma fase particular dentro do imperialismo, cuja manifestacao foi possivel devido a existencia de um lider indiscutivel. Resultados empiricos contribuem com esta hipotese.

O presente trabalho tem como objetivo identificar padroes espaciais de crescimento economico dos municipios do estado do Espirito Santo. Para tanto, utiliza-se uma base de dados referentes ao PIB per capita desses municipios, englobando o periodo 1999-2007. Do mesmo modo, sao empregados metodos de Analise Estatistica Descritiva Espacial (AEDE), procurando-se verificar a formacao de clusters de municipios com caracteristicas economicas semelhantes. Os resultados obtidos demonstram que: (i) ha evidencias de ocorrencia de transbordamentos espaciais entre os municipios analisados; (ii) ocorrem nitidas diferencas entre municipios localizados no norte ou sul do estado; (iii) ao longo do periodo 1999-2007, vem ocorrendo um padrao de crescimento onde municipios na porcao noroeste do estado tendem, em media, a crescer mais do que municipios localizados na porcao sudoeste. Esses resultados sao importantes no sentido de fornecerem primeiras evidencias relacionadas a importância de fatores geograficos no processo de crescimento dos municipios do Espirito Santo, podendo ser uteis para a formulacao e implementacao de politicas regionais que visem a promover o desenvolvimento dessas localidades. Intrastate inequalities in the Espirito Santo: an exploratory spatial approach Abstract: This paper aims to identify spatial growth patterns in the state of Espirito Santo’s municipalities. In doing so, it is used a database containing per capita GDP measures of these municipalities. We also employ methods related to Descriptive Spatial Statistical Analysis, trying to check for the formation of clusters of similar municipalities. Results obtained show that: (i) there are evidences of spatial spillovers among the state’s municipalities; (ii) there are remarkable differences between municipalities located in the northern and southern parts of the state; (iii) during the 1999-2007 period, there has been an empirical pattern where northwest area’s municipalities tend to grow faster than southwest area’s. These results are important in the sense of providing first empirical evidences related to the importance of geographical factors for the growth process of Espirito Santo’s municipalities, being useful for the formulation and implementation of regional policies aimed to promote these localities’ development. Key-words: regional economics, spatial spillovers, State of Espirito Santo. JEL: O18, R12, R58.

Resumo: A utilização do conceito imperialismo pela tradição marxista sempre esteve relacionado à tentativas de interpretação e caracterização da realidade corrente do modo de produção capitalista. As metamorfoses pelas quais o capitalismo passava na transição entre os séculos XIX e XX ensejou a contribuição da teoria marxista no que se refere ao desnudamento destas transformações. A teoria marxista registrara que o modo de produção havia ingressado em seu segundo estágio de desenvolvimento: o imperialismo. Assim, as leituras que se fizeram acerca deste novo momento passaram a ser referenciadas em termos de uma teoria clássica do imperialismo, já que forneceram o arcabouço teórico de interpretação do novo estágio do capitalismo. Atualmente existem diversas análises do capitalismo contemporâneo que, utilizando como referencial teórico o imperialismo, buscam interpretar as transformações pelas quais o capitalismo atravessa, constituindo-se como teorias contemporâneas do imperialismo. Este trabalho, então, tem como objetivo interpretar estas teorias, identificando lacunas, limites e potencialidades, à luz da teoria marxista clássica do imperialismo. Para tanto, buscou-se resgatar as contribuições teóricas dos clássicos, como Hilferding, Luxemburg, Kautski, Bukharin e Lenin. Na sequência, realizou-se a exposição e discussão entre alguns autores da atualidade para, comparando-os aos autores clássicos, chegar à conclusão de que ainda não é possível estabelecer uma teoria do imperialismo, isto é, existem várias teorias. De fato, dentro das teorias contemporâneas existe o consenso de que o capitalismo ingressou em uma nova fase, na transição entre as décadas de 1970 e 1980. Entretanto, a natureza e a forma desta nova fase ainda constituem-se pontos de forte dissenso. Palavras chave: Imperialismo. Capitalismo contemporâneo. Economia marxista.

Through for spatial econometrics – an exploratory analysis of spatial data and spatial econometric modeling - this work intend to analyze the spatial interactions present in the Municipal Development Index of Micro and Small Enterprise of Paraná (IDMPE/PR). The results suggest the presence of spatial autocorrelation, indicating some clusters.

The promotion of public policy development, focusing on results, needs indicators for monitoring its effectiveness. The indices of municipal development, synthetic indices that capture certain aspects of local development, serve as reference for the diagnosis and monitoring of the results of the action of public management, such as important tools for planning. The ID-MPE - Municipal Development Index of Micro and Small Enterprise has as propose to guide the strategies and local policies of economic promotion, aiming to capture the favorable conditions for the establishment and growth of small local businesses. Applying the methodology of the ID-MPE for Rio Grande do Sul State shows the municipalities with the best business environments for the flourishing of MPE's, and serves as a benchmark for the promotion of local development policies based on the General Law of Micro and Small Enterprise.

A Homologia de Contato Cilíndrica é uma ferramenta essencial no estudo das órbitas de Reeb periódicas. No entanto, pode não estar bem definida devido a alguns problemas de transversalidade envolvendo recobrimento múltiplos de curvas e órbitas com baixo índice. Por exemplo, Hutchings e Nelson provaram que a homologia de contato cilíndrico está bem definida sob a suposição de convexidade dinâmica, ou seja, quando os índices de todas as órbitas de Reeb são de pelo menos 3. Consideramos fluxos de Reeb de formas de contato fracamente convexas, ou seja, formas de contato cujas órbitas Reeb têm um índice de pelo menos 2. O principal obstáculo na definição do operador de fronteira é a presença de alguns buildings indesejáveis que surgem como SFT-limites de uma família de cilindros pseudo-holomorfos de índice de Fredholm 2. Concentramo-nos em buildings com dois níveis. O primeiro nível contém uma curva com um índice de Fredholm negativo e o segundo nível contém um número finito de planos rígidos assintóticos a mesma órbita de Reeb de índice $2$. Usamos a Teoria de Gluing de Hutchings e Taubes para encontrar a continuação da família de cilindros após uma colagem adequada da curva multi-coberta com planos rígidos opostos assintóticos à órbita índice 2. Então a construção do operador diferencial se resume ao caso dinamicamente convexo e a homologia de contato cilíndrico está bem definida. Assumimos que a variedade de contato admite um preenchimento simplético asférico. Esta suposição implica a existência dos planos rígidos opostos requeridos, assintóticos às órbitas de índice 2. Cylindrical Contact Homology is an essential tool in studying closed Reeb orbits. However, it may not be well-defined due to some transversality problems involving multi-covered curves and low index orbits. For instance, Hutchings and Nelson proved that cylindrical contact homology is well-defined under the dynamical convexity assumption, i.e., when the indices of all Reeb orbits are at least 3. Here, we consider Reeb flows of weakly convex contact forms, i.e., contact forms all whose Reeb orbits have an index of at least 2. The main obstacle in the definition of the boundary operator is the presence of some undesirable buildings that arise as SFT-limits of a family of Fredholm index-2 pseudo-holomorphic cylinders. We focus on buildings with two levels. The first level contains a multi-covered curve with a negative Fredholm index, and the second level contains finitely many rigid planes asymptotic to the same index-2 Reeb orbit. We use Hutchings and Taubes\' Gluing Theory to find the continuation of the family of cylinders after a suitable gluing of the multi-covered curve with opposite rigid planes asymptotic to the index-2 orbit. Then the construction of the differential operator boils down to the dynamical convex case, and the cylindrical contact homology is well-defined. We assume that the contact manifold admits an aspherical symplectic filling. This assumption implies the existence of the required opposite rigid planes asymptotic to the index-2 orbits.

Orientador: Marco Antonio Martins da Rocha Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Economia Resumo: Este trabalho aborda a categoria marxista transferência de valor de um ponto de vista teórico e empírico, em seus dois desdobramentos gerais: o intercâmbio desigual e a transferência devido à propriedade do capital. O resgate e atualização deste debate tem como objetivo investigar o funcionamento do capitalismo dependente contemporâneo, que na América Latina se desenvolve sob o signo do padrão de reprodução exportador de especialização produtiva. Nesse padrão, os mecanismos de produção e apropriação de mais-valor tendem a exacerbar a drenagem do valor produzido na região aos países do centro do sistema mundial capitalista, devido à maior estrangeirização da economia e a uma perda da complexidade produtiva, ambos os processos que tiveram lugar a partir das décadas de 1970 e 1980, e cujas políticas tornaram-se conhecidas como neoliberais. A investigação específica do caso brasileiro entre 2000 e 2014 se justifica por esse período ser qualificado por alguns autores como um momento de diminuição da vulnerabilidade externa e, consequentemente, de maior capacidade de utilização do valor produzido internamente. Na investigação empírica, foram utilizados os dados da matriz insumo-produto mundial da WIOD e os dados do balanço de pagamentos brasileiro. Os resultados mostram que durante 2003 e 2010 houve uma diminuição da transferência via intercâmbio desigual, ao mesmo tempo que aumentaram as formas de transferência via propriedade do capital. Na comparação com o PIB, houve de fato uma diminuição relativa da transferência, mas os patamares elevados de transferência negativa se mantiveram por todo o período, com tendência de elevação após o ano de 2010 Abstract: This work discusses the marxist category of value transfer from a theoretical and empirical point of view, in its two general developments: unequal exchange and transfer due to the property of capital. The updating of this debate aims to investigate the operation of contemporary dependent capitalism, which in Latin America is developing itself under the sign of the export reproduction pattern of productive specialization. In this pattern, the mechanisms of production and appropriation of surplus value tend to exacerbate the draining of the value produced in the region to the countries at the core of the capitalist world system, due to the greater foreignization of the economy and a loss of productive complexity, both processes that took place from the 1970s and 1980s onwards, and whose policies became known as neo-liberal. The specific investigation of the Brazilian case between 2000 and 2014 is justified because this period is qualified by some authors as a moment of decrease of external vulnerability and, consequently, of greater capacity of utilization of the internally produced value, especially from 2003 on. In the empirical investigation, data from WIOD's global input-output matrix and Brazilian balance of payments data were used. The specific investigation of the Brazilian case between 2000 and 2014 is justified because this period is qualified by some authors as a moment of decrease of external vulnerability and, consequently, of greater capacity of utilization of the internally produced value, especially from 2003 on. In the empirical investigation, data from WIOD's global input-output matrix and Brazilian balance of payments data were used. The results show that during 2003 and 2010 there was a decrease in the transfer through unequal exchange, at the same time that the forms of transfer via capital ownership increased. In comparison with the GDP, there was in fact a relative decrease of the transfer, but the high levels of negative transfer were maintained throughout the period, with an upward trend after 2010 Doutorado Desenvolvimento Regional e Urbano Doutor em Desenvolvimento Econômico CAPES 001

Consideramos o fluxo de Reeb associado a uma forma de contato em S¹ x S² que induz a estrutura de contato tight. Assumimos que o fluxo admite um par de órbitas periódicas L0 e L1 cujo link L = L0 L1 é transversalmente isotópico a ( S¹ x )( S¹ x ), em que n = (0,0,1) e s = (0,0,1) são os pólos norte e sul de S², respectivamente. O objetivo é provar que, nestas condições, existem infinitas órbitas periódicas no complementar desse link cujas classes de homotopia no complementar do link são prescritas de acordo com os números de rotação de L0 e L1. We consider the Reeb flow associated to a contact form on S¹ x S² which induces a tight contact structure. We assume that the flow admits a pair of closed orbits L0 and L1 whose link L = L0 L1 is transversely isotopic to (S¹ x)(S¹ x), where n = (0,0,1) and s =(0,0,1) are the north and south poles of S², respectively. The main goal is to prove that, under these conditions, there exit infinitely many closed orbits in the complement of this link whose homotopy classes in the complement of this link are prescribed according to the rotation numbers of L0 and L1.

Neste trabalho, estudamos a dinâmica de Reeb associada a uma forma de contato $\\lambda$ definida numa 3-variedade compacta e conexa M. Assumimos que $\\lambda$ é tight e a primeira classe de Chern da estrutura de contato $\\xi=\\ker\\lambda$ se anula sobre $\\pi_2(M)$. No nosso primeiro resultado, supomos que M é fechada e existe uma órbita fechada L do fluxo de Reeb que é um p-nó trivial com número de auto-enlaçamento $-1/p$. Supomos, além disso, que o número de rotação transversal da p-ésima iterada de L é estritamente menor do que 1. Nestas condições, provamos que existe uma órbita fechada (de Reeb) contrátil geometricamente distinta de L e não-enlaçada em L cujo número de rotação transversal é 1. Apresentamos também uma versão deste resultado para o caso em que M é uma 3-variedade cujo bordo é difeomorfo a um toro e invariante pelo fluxo de Reeb e não existem órbitas fechadas contidas no bordo. Nosso segundo resultado é uma caracterização dinâmica do toro sólido. Seja $\\lambda$ uma forma de contato não-degenerada definida em uma 3-variedade M cujo bordo é difeomorfo a um toro e invariante pelo fluxo de Reeb. Se o fluxo de Reeb satisfaz certas hipóteses de torção sobre o bordo, então ou existe uma órbita fechada contrátil com índice de Conley-Zehnder 2 ou M é folheada por discos transversais ao campo de Reeb. Neste último caso, M é difeomorfa a um toro sólido e existe uma órbita fechada não-contrátil em M que é ponto fixo da aplicação de retorno induzida pela folheação. In this work, we study the Reeb dynamics associated to a tight contact form $\\lambda$ defined on a compact, connected 3-manifold M. Suppose that the first Chern class of $\\xi=\\ker\\lambda$ vanish on $\\pi_2(M)$. In our first result, we assume that M is closed and there exists a closed Reeb orbit L which is a p-unknotted, has self-linking number $-1/p$ and the transverse rotation number of the p-th iterate of L is less than 1. Under these conditions, we verify that there exists a contractible closed Reeb orbit which is geometrically distinct from L and not linked to L with transverse rotation number 1. We also prove a version of this result when M is a compact 3-manifold M whose boundary is diffeomorphic to a torus and invariant by the flow and, moreover, there does not exist closed Reeb orbits on the boundary. Our second result is a dynamical characterization of the solid torus. We assume that $\\lambda$ is a contact form on a compact 3-manifold M whose boundary is diffeomorphic to a torus. Under the hypothesis of $\\lambda$ being non-degenerate, if the flow is tangent to $\\partial M$ and satisfies some twist conditions on the boundary, then either there exists a contractible closed Reeb orbit which has Conley-Zehnder index 2 or M is foliated by disks transverse to the Reeb flow. In this last case, we see that M is diffeomorphic to a solid torus and there exists a non-contractible closed Reeb orbit M which is a fixed point of the return map induced by the foliation.

Neste trabalho estudamos dinâmica Hamiltoniana em $\\mathbb{R}^4$ restrita a níveis de energia próximos a níveis críticos. Mais precisamente, consideramos uma função Hamiltoniana $H: \\mathbb{R}^4 \\to \\mathbb{R}$ que possui um ponto de equilíbrio do tipo sela-centro $p_c \\in H^{-1}(0)$ e assumimos que $p_c$ pertence a um conjunto singular estritamente convexo $S_0 \\subset H^{-1}(0)$. Então, mostramos que os níveis de energia $H^{-1}(E)$, com $E>0$ suficientemente pequeno, contêm uma $3$-bola fechada $S_E$ próxima a $S_0$ que admite um sistema de seções transversais $F_E$, chamado folheação $2-3$. $F_E$ é uma folheação singular de $S_E$ com conjunto singular formado por duas órbitas periódicas $P_{2,E}\\subset \\partial S_E$ e $P_{3,E}\\subset S_E\\setminus \\partial S_E$. A órbita $P_{2,E}$ é hiperbólica dentro do nível de energia $H^{-1}(E)$, pertence à variedade central do sela-centro $p_c$, tem índice de Conley-Zehnder $2$ e é o limite assintótico de dois planos rígidos de $F_E$ que, unidos com $P_{2,E}$, constituem a $2$-esfera $\\partial S_E$. A órbita $P_{3,E}$ tem índice de Conley-Zehnder $3$ e é o limite assintótico de uma família a um parâmetro de planos de $F_E$ contida em $S_E\\setminus \\partial S_E$. Um cilindro rígido conectando as órbitas $P_{3,E}$ e $P_{2,E}$ completa a folheação $F_E$. Uma vez que $F_E$ é um sistema de seções transversais, todas as suas folhas regulares são transversais ao fluxo Hamiltoniano de $H$. Como consequência da existência de uma tal folheação em $S_E$, concluímos que a órbita hiperbólica $P_{2,E}$ admite pelo menos uma órbita homoclínica contida em $S_E \\setminus \\partial S_E$. In this work we study Hamiltonian dynamics in $\\mathbb R ^4$ restricted to energy levels close to critical levels. More precisely, we consider a Hamiltonian function $H:\\mathbb R ^4 \\to \\mathbb R$ containing a saddle-center equilibrium point $p_c \\in H^ -1 (0)$ and we assume that $p_c$ lies on a strictly convex singular set $S_0 \\subset H^ -1 (0)$. Then we prove that the energy levels $H^ -1 (E)$, with $E>0$ sufficiently small, contain a closed $3$-ball $S_E$ near $S_0$ admitting a system of transverse sections $F_E$, called a $2-3$ foliation. $F_E$ is a singular foliation of $S_E$ and its singular set consists of two periodic orbits $P_{2,E}\\subset \\partial S_E$ and $P_{3,E}\\subset S_E\\setminus \\partial S_E$. The orbit $P_{2,E}$ is hyperbolic inside the energy level $H^ -1 (E)$, lies on the center manifold of the saddle-center $p_c$, has Conley-Zehnder index $2$ and is the asymptotic limit of two rigid planes of $F_E$, which compose the $2$-sphere $S_E$ together with $P_{2,E}$. The orbit $P_{3,E}$ has Conley-Zehnder index $3$ and is the asymptotic limit of a one parameter family of planes of $F_E$ contained in $S_E \\setminus \\partial S_E$. A rigid cylinder connecting the orbits $P_{3,E}$ and $P_{2,E}$ completes the foliation $F_E$. Since $F_E$ is a system of transverse sections, all its regular leaves are transverse to the Hamiltonian flow of $H$. As a consequence of the existence of such foliation in $S_E$, we conclude that the hyperbolic orbit $P_{2,E}$ admits at least one homoclinic orbit contained in $S_E\\setminus \\partial S_E$.