Algoritmos recursivos e não-recursivos aplicados à estimação fasorial em sistemas elétricos de potência

Este trabalho apresenta uma análise de algoritmos computacionais aplicados à estimação de fasores elétricos em SEPs. A medição dos fasores é realizada por meio da alocação de Unidades de Medição Fasorial nestes sistemas e encontra diversas aplicações nas áreas de operação, controle, proteção e planejamento. Para que os fasores possam ser aplicados, são definidos padrões de medição, sincronização e comunicação, por meio da norma IEEE C37.118.1. A norma apresenta os padrões de mensagens, timetag, fasores, sistema de sincronização, e define testes para avaliar a estimação. Apesar de abranger todos esses critérios, a diretriz não define um algoritmo de estimação padrão, abrindo espaço para uso de diversos métodos, desde que a precisão seja atendida. Nesse contexto, o presente trabalho analisa alguns algoritmos de estimação de fasores definidos na literatura, avaliando o comportamento deles em determinados casos. Foram considerados, dessa forma, os métodos: Transformada Discreta de Fourier, Método dos Mínimos Quadrados e Transformada Wavelet Discreta, nas versões recursivas e não-recursivas. Esses métodos foram submetidos a sinais sintéticos, a fim de verificar o comportamento diante dos testes propostos pela norma, avaliando o Total Vector Error, tempo de resposta e atraso e overshoot. Os algoritmos também foram embarcados em um hardware, denominado PC104, e avaliados de acordo com os sinais medidos pelo equipamento na saída analógica de um simulador em tempo real (Real Time Digital Simulator).

Ligantes de miócitos cardíacos para a glicoproteína de 85kda. (tc-85) de Trypanosoma cruzi

O Trypanosoma cruzi expressa um grupo de glicoprotcinas de superfície, denominadas Tc-85, que pertencem à superfumília gêmca das gp85/traus-sialidases. Nosso laboratório clonou e caracterizou um membro da fumília Tc85 (Tc85-11), cuja região carboxila tenninal (clone Tc85-1) adere em laminina e em células de mamífero. Usando peptídeos sintéticos, correspondendo em seqüência à Tc85-1, caracterizou-se o motivo mais conservado da superfamilia gênica das gp85/trans-sialidases (VTVxNVFLYNR), o qual não adere em laminina. Esse motivo foi chamado peptídeo J. Por cromatografia de extratos de membrana de cardiomiócitos em coluna de afmidade contendo peptídeo J, foi isolada uma molécula de 30kDa identificada como sendo a subunidade β3 da Na+, K+ ATPase. A porção extracelular da subunidade β3 da Na+, K+ ATPase foi clonada e a interação in vitro desta proteína com peptídeo J foi observada. Deste modo, é sugerido aqui que a subunidade β3 da Na+, K+ ATPase pode ter um papel importante na interação do parasita com a célula hospedeira.

Extração, determinação da composição fenólica e avaliação do potencial de desativação de espécies reativas de oxigênio e da atividade anti-inflamatória de resíduos de amendoim, pimenta-rosa e pimenta-do-reino

O setor agroindustrial tem se expandido muito nos últimos anos, levando o país a um aumento na geração de resíduos agroindustriais, sendo que a maior parte deles ainda é descartada no meio ambiente, sem tratamento adequado, ou utilizada na alimentação animal, destinos que a priori, não geram ganhos econômicos para a agroindústria além de representarem gargalos logísticos e ambientais na sua disposição. Nesse sentido, o presente trabalho teve como objetivos otimizar o processo de extração de compostos bioativos, avaliar in vitro as atividades antioxidante, por meio da desativação de espécies reativas de oxigênio, e anti-inflamatória, bem como determinar a composição fenólica dos resíduos agroindustriais a saber: película de amendoim (Arachis hypogaea) (cultivares IAC886 e IAC505), pimenta-rosa (Schinus terebinthifolius Raddi) e pimenta-do-reino (Piper Nigrum L). O processo de otimização da extração de compostos antioxidantes foi realizado utilizando dois processos de extração, extração convencional e subcrítica, em delineamento composto central rotacional, utilizando como variáveis a temperatura e tempo e a pressão e temperatura, respectivamente, com os solventes etanol 80%, água e propilenoglicol 80%. Durante o processo de otimização a atividade antioxidante foi avaliada pelo método de sequestro do radical ABTS. Os melhores resultados foram obtidos para a extração convencional com os solventes etanol 80%, água e propilenoglicol 80%. A película de amendoim (IAC505) apresentou as maiores atividades antioxidantes (1.396,67, 580,44 e 859,89 μmol.g-1 em equivalentes de trolox, para os solventes etanol 80%, água e propilenoglicol 80%, respectivamente). A partir dos resultados obtidos para os solventes testados, utilizando a extração convencional, foram feitas outras análises de atividade antioxidante considerando o tempo e temperatura ideal de extração. Foram realizadas análises de avaliação da capacidade de redução de Folin-Ciocalteau e potencial de desativação dos radicais livres sintéticos (DPPH e ABTS) e espécies reativas de oxigênio (radicais peroxila, superóxido e ácido hipocloroso). O solvente de extração que apresentou melhores resultados em todos os ensaios foi o etanol 80%, sendo, portanto o solvente utilizado nas análises subsequentes. A partir da definição do melhor sistema extrator foram realizadas análises da composição fenólica, por meio das técnicas de cromatografia líquida de alta eficiência em modo analítico (HPLC-RP), cromatografia gasosa acoplada com espectrometria de massas (GC-MS), e avaliação in vitro da atividade anti-inflamatória. Foram identificados nos resíduos estudados procianidinas B1 e B2, ácido p-cumárico, miricetina, ácido ferúlico, ácido siríngico, ácido sinápico, epicatequina e catequina. A pimenta-do-reino diminui significativamente os níveis de TNF-α e nitritos, reduzindo assim o processo inflamatório gerado. Os resultados obtidos neste trabalho demonstram que estes resíduos agroindústrias possuem grande potencial biológico, podendo assim ser melhores aproveitados tanto pela indústria de alimentos quanto pela indústria farmacêutica.

Estudio mediante dinámica molecular del efecto de la radiación e isótopos de H en diamante para su aplicación en fusión

Las recientes mejoras en la síntesis de Diamante artificial han logrado cristales de mayor tamaño, propiedades optimizadas y en muchos casos superiores a sus variantes naturales. Con ello, los cristales sintéticos de Diamante, pasan a ser una alternativa seria en aplicaciones de Fusión Nuclear. Algunas de las propiedades deseables para dichas aplicaciones son especialmente notables en Diamante, entre otras su conductividad térmica o su amplio rango de transparencia electromagnética. Sin embargo, el conocimiento acumulado acerca de su comportamiento bajo radiación, o más concretamente bajo las condiciones radiactivas de Fusión, es todavía limitado. En aplicaciones de Fusión nuclear, es imprescindible conocer el efecto de la radiación neutrónica y la interacción del material con Hidrógeno, sus isótopos y otros elementos ligeros propios de los plasmas de Fusión. No nos consta una bibliografía extensa acerca del daño por radiación en Diamante, existen estudios poco concluyentes acerca de la energía umbral de desplazamiento, se ha estudiado la grafitización o amorfización y tópicos tales como la implantación o el daño por bombardeo electrónico, iónico o gamma, pero no se han encontrado trabajos previos a esta tesis en cascadas de desplazamientos 1 y, como veremos, apenas unos pocos trabajos utilizan la técnica de la Dinámica Molecular en estudios de daño por radiación en este material. La interacción del Hidrógeno en la red de Diamante sí ha sido extensamente estudiada, se conocen multitud de líneas de absorción relacionadas con su presencia, se ha estudiado su difusión mediante técnicas experimentales y existen descripciones atomísticas de los sitios de equilibrio en la red de Diamante, aislado o formando parte de agregados...

Formação de ligação carbono-carbono através de compostos orgânicos de telúrio

Diversas classes de compostos orgânicos de telúrio foram exploradas neste trabalho. Inicialmente foi estudada a transmetalação entre teluretos alílicos e dibutil cianocupratos de lítio de ordem superior, levando aos respectivos cianocupratos alílicos de lítio. Estes, por sua vez, foram acoplados com triflatos vinílicos, importantes intermediários sintéticos preparados previamente a partir de teluretos vinílicos, levando a sistemas altamente insaturados em ótimos rendimentos (Esquema 1). (Ver no arquivo em PDF) Em seguida, foi explorada a reatividade de teluretos aromáticos frente a reagentes organometálicos. Cianocupratos arílicos, gerados a partir da transmetalação entre teluretos aromáticos com cianocupratos de lítio de ordem superior, foram adicionados a cetonas α,β -insaturadas, levando aos produtos de adição 1,4 em bons rendimentos (Esquema 2). (Ver no arquivo em PDF) Teluretos vinílicos funcionalizados de configuração Z também foram alvo de estudo visando a formação de ligação carbono-carbono. Reações de substituição entre estes teluretos e cianocupratos de lítio de ordem inferior levaram a cetonas e ésteres α,β- insaturados com estereoquímica defInida em ótimos rendimentos (Esquema 3). (Ver no arquivo em PDF) De agosto/20OJ a março/2004, a aluna realizou um estágio sanduíche na University of California, Santa Barbara, sob a orientação do Prof. Bruce H. Lipshutz, onde realizou estudos sobre a ciclização de Bergman, visando a síntese do fragmentobiarílico A-B da vancornicina. Diversas condições para a ciclização foram estudadas com um composto modelo (Esquema 4) (Ver no arquivo em PDF) e parte da síntese total do fragmento da vancomlcma, onde a ciclização seria a etapa-chave, foi realizada com sucesso (Esquema 5). (Ver no arquivo em PDF)

Características dos materiais de regeneração óssea existentes em Portugal

Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz

Substâncias de abuso emergentes: "legal highs": toxicidade e risco

Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz

Substâncias psicoativas de venda legal em smart shops: princípios ativos e formas de deteção

Dissertação para obtenção do grau de Mestre no Instituto Superior de Ciências da Saúde Egas Moniz

Estudo da participação das espécies fortemente oxidantes produzidas durante a oxidação eletroquímica de corantes usando eletrodo de diamante dopado com boro: função das propriedades eletroquímicas do eletrodo e condições experimentais

The textile industry is one of the most polluting in the world (AHMEDCHEKKAT et al. 2011), generating wastewater with high organic loading. Among the pollutants present in these effluents are dyes, substances with complex structures, toxic and carcinogenic characteristics, besides having a strong staining. Improper disposal of these substances to the environment, without performing a pre-treatment can cause major environmental impacts. The objective this thesis to use a technique of electrochemical oxidation of boron doped diamond anode, BDD, for the treatment of a synthetic dye and a textile real effluent. In addition to studying the behavior of different electrolytes (HClO4, H3PO4, NaCl and Na2SO4) and current densities (15, 60, 90 and 120 mA.cm-2 ), and compare the methods with Rhodamine B (RhB) photolysis, electrolysis and photoelectrocatalytic using H3PO4 and Na2SO4. Electrochemical oxidation studies were performed in different ratio sp3 /sp2 of BDD with solution of RhB. To achieve these objectives, analysis of pH, conductivity, UV-visible, TOC, HPLC and GC-MS were developed. Based on the results with the Rhodamine B, it was observed that in all cases occurred at mineralization, independent of electrolyte and current density, but these parameters affect the speed and efficiency of mineralization. The radiation of light was favorable during the electrolysis of RhB with phosphate and sulfate. Regarding the oxidation in BDD anode with different ratio sp3 /sp2 (165, 176, 206, 220, 262 e 329), with lower carbon-sp3 had a longer favoring the electrochemical conversion of RhB, instead of combustion. The greater the carbon content on the anodes BDD took the biggest favor of direct electrochemical oxidation

Segmentação fuzzy de objetos tridimensionais com propriedades texturais

Digital image segmentation is the process of assigning distinct labels to different objects in a digital image, and the fuzzy segmentation algorithm has been used successfully in the segmentation of images from several modalities. However, the traditional fuzzy segmentation algorithm fails to segment objects that are characterized by textures whose patterns cannot be successfully described by simple statistics computed over a very restricted area. In this paper we present an extension of the fuzzy segmentation algorithm that achieves the segmentation of textures by employing adaptive affinity functions as long as we extend the algorithm to tridimensional images. The adaptive affinity functions change the size of the area where they compute the texture descriptors, according to the characteristics of the texture being processed, while three dimensional images can be described as a finite set of two-dimensional images. The algorithm then segments the volume image with an appropriate calculation area for each texture, making it possible to produce good estimates of actual volumes of the target structures of the segmentation process. We will perform experiments with synthetic and real data in applications such as segmentation of medical imaging obtained from magnetic rosonance

Aplicação da tecnologia eletroquímica para a remoção e monitoramento de metais pesados em efluentes aquosos

Heavy metals are present in industrial waste. These metals can generate a large environmental impact contaminating water, soil and plants. The chemical action of heavy metals has attracted environmental interest. In this context, this study aimed to test t he performance of electrochemical technologies for removing and quantifying heavy metals. First ly , the electroanalytical technique of stripping voltammetry with glassy carbon electrode (GC) was standardized in order to use this method for the quantificatio n of metals during their removal by electrocoagulation process (EC). A nalytical curves were evaluated to obtain reliability of the determin ation and quantification of Cd 2+ and Pb 2+ separately or in a mixture. Meanwhile , EC process was developed using an el ectrochemical cell in a continuous flow (EFC) for removing Pb 2+ and Cd 2+ . The se experiments were performed using Al parallel plates with 10 cm of diameter (  63.5 cm 2 ) . The optimization of conditions for removing Pb 2+ and Cd 2+ , dissolved in 2 L of solution at 151 L h - 1 , were studied by applying different values of current for 30 min. Cd 2+ and Pb 2+ concentrations were monitored during electrolysis using stripping voltammetry. The results showed that the removal of Pb 2 + was effective when the EC pro cess is used, obtaining removals of 98% in 30 min. This behavior is dependent on the applied current, which implies an increase in power consumption. From the results also verified that the stripping voltammetry technique is quite reliable deter mining Pb 2+ concentration , when compared with the measurements obtained by atomic absorption method (AA). In view of this, t he second objective of this study was to evaluate the removal of Cd 2+ and Pb 2+ (mixture solution) by EC . Removal efficiency increasing current was confirmed when 93% and 100% of Cd 2+ and Pb 2+ was removed after 30 min . The increase in the current promotes the oxidation of sacrificial electrodes, and consequently increased amount of coagulant, which influences the removal of heavy metals in solution. Adsortive voltammetry is a fast, reliable, economical and simple way to determine Cd 2+ and Pb 2+ during their removal. I t is more economical than those normally used, which require the use of toxic and expensive reagents. Our results demonstrated the potential use of electroanalytical techniques to monitor the course of environmental interventions. Thus, the application of the two techniques associated can be a reliable way to monitor environmental impacts due to the pollution of aquatic ecosystems by heavy metals.

Transformações químicas, caracterizações e estudo de modelagem molecular do clerodano bioativo trans-desidrocrotonina

In this work it were developed synthetic and theoretical studies for clerodane-type diterpenes obtained from Croton cajucara Benth which represents one of the most important medicinal plant of the Brazil amazon region. Specifically, the majoritary biocompound 19-nor-clerodane trans-dehydrocrotonin (t-DCTN) isolated from the bark of this Croton, was used as target molecule. Semi-synthetic derivatives were obtained from t-DCTN by using the followed synthetic procedures: 1) catalytic reduction with H2, 2) reduction using NaBH4 and 3) reduction using NaBH4/CeCl3. The semi-synthetic 19-nor-furan-clerodane alcohol-type derivatives were denominated such as t-CTN, tCTN-OL, t-CTN-OL, t-DCTN-OL, t-DCTN-OL, being all of them characterized by NMR. The furan-clerodane alcohol derivatives t-CTN-OL and tCTN-OL were obtained form the semi-synthetic t-CTN, which can be isolated from the bark of C. cajucara. A theoretical protocol (DFT/B3LYP) involving the prevision of geometric and magnetic properties such as bond length and angles, as well as chemical shifts and coupling constants, were developed for the target t-DCTN in which was correlated NMR theoretical data with structural data, with satisfactory correlation with NMR experimental data (coefficients ranging from 0.97 and 0.99) and X-ray diffraction data. This theoretical methodology was also validated for all semi-synthetic derivatives described in this work. In addition, topological data from the Quantum Theory of Atoms in Molecules (QTAIM) showed the presence of H-H and (C)O--H(C) intramolecular stabilized interactions types for t-DCTN e t-CTN, contributing to the understanding of the different reactivity of this clerodanes in the presence of NaBH4.

Um algoritmo paralelo eficiente de migração reversa no tempo (rtm) 3d com granularidade fina

The reverse time migration algorithm (RTM) has been widely used in the seismic industry to generate images of the underground and thus reduce the risk of oil and gas exploration. Its widespread use is due to its high quality in underground imaging. The RTM is also known for its high computational cost. Therefore, parallel computing techniques have been used in their implementations. In general, parallel approaches for RTM use a coarse granularity by distributing the processing of a subset of seismic shots among nodes of distributed systems. Parallel approaches with coarse granularity for RTM have been shown to be very efficient since the processing of each seismic shot can be performed independently. For this reason, RTM algorithm performance can be considerably improved by using a parallel approach with finer granularity for the processing assigned to each node. This work presents an efficient parallel algorithm for 3D reverse time migration with fine granularity using OpenMP. The propagation algorithm of 3D acoustic wave makes up much of the RTM. Different load balancing were analyzed in order to minimize possible losses parallel performance at this stage. The results served as a basis for the implementation of other phases RTM: backpropagation and imaging condition. The proposed algorithm was tested with synthetic data representing some of the possible underground structures. Metrics such as speedup and efficiency were used to analyze its parallel performance. The migrated sections show that the algorithm obtained satisfactory performance in identifying subsurface structures. As for the parallel performance, the analysis clearly demonstrate the scalability of the algorithm achieving a speedup of 22.46 for the propagation of the wave and 16.95 for the RTM, both with 24 threads.

Tecnologia eletroquímica como tratamento alternativo de efluentes derivados da indústria têxtil e petroquímica

In this work, the treatment of wastewater from the textile industry, containing dyes as Yellow Novacron (YN), Red Remazol BR (RRB) and Blue Novacron CD (NB), and also, the treatment of wastewater from petrochemical industry (produced water) were investigated by anodic oxidation (OA) with platinum anodes supported on titanium (Ti/Pt) and boron-doped diamond (DDB). Definitely, one of the main parameters of this kind of treatment is the type of electrocatalytic material used, since the mechanisms and products of some anodic reactions depend on it. The OA of synthetic effluents containing with RRB, NB and YN were investigated in order to find the best conditions for the removal of color and organic content of the dye. According to the experimental results, the process of OA is suitable for decolorization of wastewaters containing these textile dyes due to electrocatalytic properties of DDB and Pt anodes. Removal of the organic load was more efficient at DDB, in all cases; where the dyes were degraded to aliphatic carboxylic acids at the end of the electrolysis. Energy requirements for the removal of color during OA of solutions of RRB, NB and YN depends mainly on the operating conditions, for example, RRB passes of 3.30 kWh m-3 at 20 mA cm-2 for 4.28 kWh m-3 at 60 mA cm-2 (pH = 1); 15.23 kWh m-3 at 20 mA cm-2 to 24.75 kWh m-3 at 60 mA cm-2 (pH 4.5); 10.80 kWh m-3 at 20 mA cm-2 to 31.5 kWh m-3 at 60 mA cm-2 (pH = 8) (estimated data for volume of treated effluent). On the other hand, in the study of OA of produced water effluent generated by petrochemical industry, galvanostatic electrolysis using DDB led to the complete removal of COD (98%), due to large amounts of hydroxyl radicals and peroxodisulphates generated from the oxidation of water and sulfates in solution, respectively. Thus, the rate of COD removal increases with increasing applied current density (15-60 mAcm-2 ). Moreover, at Pt electrode, approximately 50% removal of the organic load was achieved by applying from 15 to 30 mAcm-2 while 80% of COD removal was achieved for 60 mAcm-2 . Thus, the results obtained in the application of this technology were satisfactory depending on the electrocatalytic materials and operating conditions used for removal of organic load (petrochemical and textile effluents) as well as for the removal of color (in the case of textile effluents). Therefore, the applicability of electrochemical treatment can be considered as a new alternative like pretreatment or treatment of effluents derived from textiles and petrochemical industries.

Escrita colaborativa com google docs: flash fiction, noticing e aprendizagem de inglês como L2

Google Docs (GD) is an online word processor with which multiple authors can work on the same document, in a synchronous or asynchronous manner, which can help develop the ability of writing in English (WEISSHEIMER; SOARES, 2012). As they write collaboratively, learners find more opportunities to notice the gaps in their written production, since they are exposed to more input from the fellow co-authors (WEISSHEIMER; BERGSLEITHNER; LEANDRO, 2012) and prioritize the process of text (re)construction instead of the concern with the final product, i.e., the final version of the text (LEANDRO; WEISSHEIMER; COOPER, 2013). Moreover, when it comes to second language (L2) learning, producing language enables the consolidation of existing knowledge as well as the internalization of new knowledge (SWAIN, 1985; 1993). Taking this into consideration, this mixed-method (DÖRNYEI, 2007) quasi-experimental (NUNAN, 1999) study aims at investigating the impact of collaborative writing through GD on the development of the writing skill in English and on the noticing of syntactic structures (SCHMIDT, 1990). Thirtyfour university students of English integrated the cohort of the study: twenty-five were assigned to the experimental group and nine were assigned to the control group. All learners went through a pre-test and a post-test so that we could measure their noticing of syntactic structures. Learners in the experimental group were exposed to a blended learning experience, in which they took reading and writing classes at the university and collaboratively wrote three pieces of flash fiction (a complete story told in a hundred words), outside the classroom, online through GD, during eleven weeks. Learners in the control group took reading and writing classes at the university but did not practice collaborative writing. The first and last stories produced by the learners in the experimental group were analysed in terms of grammatical accuracy, operationalized as the number of grammar errors per hundred words (SOUSA, 2014), and lexical density, which refers to the relationship between the number of words produced with lexical properties and the number of words produced with grammatical properties (WEISSHEIMER, 2007; MEHNERT, 1998). Additionally, learners in the experimental group answered an online questionnaire on the blended learning experience they were exposed to. The quantitative results showed that the collaborative task led to the production of more lexically dense texts over the 11 weeks. The noticing and grammatical accuracy results were different from what we expected; however, they provide us with insights on measurement issues, in the case of noticing, and on the participants‟ positive attitude towards collaborative writing with flash fiction. The qualitative results also shed light on the usefulness of computer-mediated collaborative writing in L2 learning.