Energia eólica em alto mar: distribuição dos recursos e complementaridade hídrica

The stabilization of energy supply in Brazil has been a challenge for the operation of the National Interconnected System in face of hydrological and climatic variations. Thermoelectric plants have been used as an emergency source for periods of water scarcity. The utilization of fossil fuels, however, has elevated the cost of electricity. On the other hand, offshore wind energy has gained importance in the international context and is competitive enough to become a possibility for future generation in Brazil. In this scenario, the main goal of this thesis was to investigate the magnitude and distribution of offshore wind resources, and also verify the possibilities of complementing hydropower. A data series of precipitation from the Climatic Research Unit (CRU) Blended Sea Winds from the National Climatic Data Center (NCDC/NOAA) were used. According to statistical criteria, three types of complementarity were found in the Brazilian territory: hydro × hydro, wind × wind and hydro × wind. It was noted a significant complementarity between wind and hydro resources (r = -0.65), mainly for the hydrographical basins of the southeast and central regions with Northeastern Brazil winds. To refine the extrapolation of winds over the ocean, a method based on the Monin-Obukhov theory was used to model the stability of the atmospheric boundary layer. Objectively Analyzed Air-Sea Flux (OAFLUX) datasets for heat flux, temperature and humidity, and also sea level pressure data from NCEP/NCAR were used. The ETOPO1 from the National Geophysical Data Center (NGDC/NOAA) provided bathymetric data. It was found that shallow waters, between 0-20 meters, have a resource estimated at 559 GW. The contribution of wind resources to hydroelectric reservoir operation was investigated with a simplified hybrid wind-hydraulic model, and reservoir level, inflow, outflow and turbine production data. It was found that the hybrid system avoids drought periods, continuously saving water from reservoirs through wind production. Therefore, from the results obtained, it is possible to state that the good winds from the Brazilian coast can, besides diversifying the electric matrix, stabilize the hydrological fluctuations avoiding rationing and blackouts, reducing the use of thermal power plants, increasing the production cost and emission of greenhouse gases. Public policies targeted to offshore wind energy will be necessary for its full development.

Saberes e perspectivas dos docentes em torno do currículo de uma escola pública rural do RN

Este trabajo tiene como objetivo analizar los saberes y las perspectivas docentes en torno al currículum de una escuela pública rural de Enseñanza Fundamental del Río Grande do Norte considerando, sobre todo, los debates sobre la Educación en el Campo en Souza (2006, 2007), Arroyo, Caldart y Molina (2004) y Fernandes (2002, 2004). La propuesta surge como alternativa para la elaboración de proposiciones curriculares para mejorar la calidad de la enseñanza en esas escuelas, según las características específicas de la educación escolar en contexto rural, en la expectativa de que esta sea un elemento para el desarrollo local y global de las comunidades rurales. La fundamentación teórica para responder a la investigación, se respalda en las consideraciones sobre los saberes docentes teniendo en cuenta las lecturas de Gauthier (1998), Tardif (2011), Pimenta (2009), Paulo Freire (1996), Nóvoa (2007, 2008) y las referencias sobre el currículum crítico y postcrítico discutidas en Giroux (1997), Silva (1999), Moreira (2008), Moreira y Candau (2003, 2010), Sacristán (2000) e Sacristán e Gómez (1998). La referencia empírica se constituye de una escuela pública de una comunidad rural en el municipio de São José de Mipibu-RN. Los sujetos sociales de la investigación son cuatro profesores(as) que trabajan en los años iniciales de la Enseñanza Fundamental. Se recurrió a la investigación etnográfica fundamentada en los estudios de Lüdke y André (1986), Sandín Estebán (2010) y Gil (2007), una vez que el análisis del cotidiano escolar, bajo el mirar etnográfico, a través de los procedimientos de la observación participante y de la entrevista semiestructurada, permite el contacto directo del investigador con el ambiente en estudio, registra el no documentado, y percibe la institución escolar como espacio cultural, caracterizando varios grados de acomodación, contestación y resistencia inmersos en una pluralidad de lenguajes y objetivos conflictivos. Las observaciones hechas en la clase y las enseñanzas de los profesores y profesoras permiten comprender que los saberes y perspectivas docentes, a partir de las experiencias del profesorado, lanzan expectativas socioprofesionales sobre la docencia e intensifican el papel fundamental del docente en la construcción de los saberes, de las prácticas y concepciones del mundo rural, de la escuela rural y de la función social de esta. Los hallazgos de la investigación con los profesores sobre el contexto rural apuntan para la necesidad en problematizar verdades socialmente construidas, bajo la orientación de una racionalidad que reconozca el espacio rural como productor de la existencia. A partir de los análisis construidos, se pudo reconocer la necesidad de una política de formación conceptual específica para el profesorado de las escuelas rurales, anclada en el concepto históricocultural del rural. También se reitera la urgencia permanente y continuada en revisar los procesos de formación, vividos en la escuela, que contemplen las peculiaridades de la enseñanza rural, en una visión contrahegemónica del urbanocentrismo, a partir de un análisis crítico sobre el marco legal de la Educación del Campo.

Processo identitário e saberes docentes: um estudo a partir da prática de ensino no estágio do curso de pedagogia da UFRN

Esta investigación parte del interés en la comprensión de la cuestión de los conocimientos enseñanza, precisamente el conocimiento necesario para el profesor profesional relacionada enseñanza, es decir, cuáles son los conocimientos, los profesores a construir en su contexto de trabajo. Somos conscientes de que el escenario es un momento de importancia fundamental para el desarrollo del conocimiento inicial de la profesión docente y la construcción de la identidad profesional. Tratando de entender estos aspectos nos preguntamos: ¿Qué conocimientos de los futuros profesores construyen o se movilizan durante la práctica docente desarrollado en el escenario? Nuestro objetivo es entender el proceso de identidad de estudiantes Pedagogía UFRN e identificar el conocimiento construido sobre la práctica docente desarrollada durante el entrenamiento supervisado de dicho curso. Se trata de una investigación cualitativa, y tenía como instrumento de recolección de datos, entrevistas semi-estructuradas con diez (10) en 2014.1 académicos que habían ocupado la práctica docente en el entrenamiento supervisado. Las entrevistas fueron sometidas a análisis de contenido propuesto por Bardin (2011). Como marco teórico, los autores también apoyan en tan Tardif (2012), Pimenta (2012), Nóvoa (1995), Perrenoud (2002), entre otros, se trata de la enseñanza de conocimientos dentro de la profesionalización docente, estableciendo relación con el proceso de identidad. Los resultados indican que, en lo que respecta a la identidad profesional, estudios teóricos en el curso de formación inicial, junto con las experiencias vividas en su mayoría en el escenario, contribuyeron a cambiar lo que los estudiantes sabían acerca de ser un maestro. Por lo tanto, algunos han fortalecido la identidad con la profesión, mientras que otros han renunciado a invertir en la carrera docente. En cuanto a conocimiento construido, se puede decir que los alumnos se dan cuenta de la pluralidad de conocimientos necesarios para una profesión tan compleja como la enseñanza. Sin embargo, a modo de síntesis, este conocimiento a su vez a aprender a planificar lecciones considerando las necesidades de los estudiantes y su contexto social. Los participantes declaran saber cómo llevar a cabo la mediación del aprendizaje a través del diálogo y actividades bien estructuradas y afecto contribuye al aprendizaje. En este sentido, se entiende que las construcciones de conocimiento en el escenario se articularon a reflexionar sobre su propia práctica e indican lo que era más importante en términos de aprendizaje de la percepción de los estudiantes. Sobre la base de este entendimiento, creemos que los momentos de observación (primero paso en el escenario) y el muy regencia podrían considerarse en el proceso de formación, para que los estudiantes se registre el aprendizaje proporcionado por la práctica. Es necesario, por tanto, que los estudiantes investiguen su propia actividad pedagógica, convirtiendo sus conocimientos en una continua construcción y reconstrucción de sus identidades a partir de la importancia social que conceden a la enseñanza.

Análise experimental do consumo de um veículo flex operando com diferentes misturas de gasolina/etanol em tráfego urbano

This study is an analysis, on a trial basis, the fuel consumption of a Flex vehicle, operating with different mixtures of gasoline and ethanol in urban traffic, allowing more consistent results with the reality of the driver. Considering that most owners unaware of the possibility of mixing the fuel at the time of supply, thus enabling the choice of the most economically viable mixing gasoline / ethanol, resulting in lower costs and possibly a decrease in pollutant emission rates. Currently, there is a myth created by the people that supply ethanol only becomes viable if the value of not more than 70% of regular gasoline. However vehicles with this technology make it possible to operate with any percentage of mixture in the fuel tank, but today many of the owners of these vehicles do not use this feature effectively, because they ignore the possibility of mixing or the reason there is a deeper study regarding the optimal percentage of the mixture to provide a higher yield with a lower cost than proposed by the manufacturers.

Análise experimental do consumo de um veículo flex operando com diferentes misturas de gasolina/etanol em tráfego urbano

This study is an analysis, on a trial basis, the fuel consumption of a Flex vehicle, operating with different mixtures of gasoline and ethanol in urban traffic, allowing more consistent results with the reality of the driver. Considering that most owners unaware of the possibility of mixing the fuel at the time of supply, thus enabling the choice of the most economically viable mixing gasoline / ethanol, resulting in lower costs and possibly a decrease in pollutant emission rates. Currently, there is a myth created by the people that supply ethanol only becomes viable if the value of not more than 70% of regular gasoline. However vehicles with this technology make it possible to operate with any percentage of mixture in the fuel tank, but today many of the owners of these vehicles do not use this feature effectively, because they ignore the possibility of mixing or the reason there is a deeper study regarding the optimal percentage of the mixture to provide a higher yield with a lower cost than proposed by the manufacturers.

Prevalência de alterações fundoscópicas em estudantes na cidade de Natal/Brasil

Objetivo: Determinar a prevalência de alterações fundoscópicas em estudantes de escolas das redes pública e privada de Natal-RN. Métodos: Avaliação oftalmológica foi realizada em 990 alunos, de 5 a 21 anos, matriculados nas escolas das redes públicas e privada do município de Natal- RN, que estiveram cursando alguma série do ensino fundamental ou médio, no período de 03 a 06 de 2001. Resultados: Alterações fundoscópicas foram observadas em 5,3% dos estudantes. As anormalidades encontradas, por ordem de freqüência, foram: branco sem pressão, 1,0%; cicatriz de retinocoroidite sugestiva de toxoplasmose, 1,0%; atrofia do epitélio pigmentado da retina, 0,8%; nevos da coróide, 0,4%; escavação da cabeça do nervo óptico aumentada, 0,4%; degeneração em treliça, 0,3%; buraco operculado, 0,2%; fundus miópico, 0,2%; tortuosidade vascular aumentada, 0,2%; granuloma sugestivo de toxocaríase, 0,2%; hipoplasia da cabeça do nervo óptico, 0,1%; persistência da artéria hialoidea, 0,1%; persistência de fibras de mielina, 0,1%; retina sal e pimenta, 0,1%; retinosquise, 0,1%. Conclusão: Houve uma baixa prevalência de alterações fundoscópicas na população estudada

Prevalência de alterações fundoscópicas em estudantes na cidade de Natal-Brasil

Objetivo: Determinar a prevalência de alterações fundoscópicas em estudantes de escolas das redes pública e privada de Natal-RN. Métodos: Avaliação oftalmológica foi realizada em 990 alunos, de 5 a 21 anos, matriculados nas escolas das redes públicas e privada do município de Natal-RN, que estiveram cursando alguma série do ensino fundamental ou médio, no período de 03 a 06 de 2001. Resultados: Alterações fundoscópicas foram observadas em 5,3% dos estudantes. As anormalidades encontradas, por ordem de freqüência, foram: branco sem pressão, 1,0%; cicatriz de retinocoroidite sugestiva de toxoplasmose, 1,0%; atrofia do epitélio pigmentado da retina, 0,8%; nevos da coróide, 0,4%; escavação da cabeça do nervo óptico aumentada, 0,4%; degeneração em treliça, 0,3%; buraco operculado, 0,2%; fundus miópico, 0,2%; tortuosidade vascular aumentada, 0,2%; granuloma sugestivo de toxocaríase, 0,2%; hipoplasia da cabeça do nervo óptico, 0,1%; persistência da artéria hialoidea, 0,1%; persistência de fibras de mielina, 0,1%; retina sal e pimenta, 0,1%; retinosquise, 0,1%. Conclusão: Houve uma baixa prevalência de alterações fundoscópicas na população estudada

Gestão da informação: um estudo de caso em um instituto de pesquisa tecnológica

Each two years the amount of available information in the world double. This is the Information Age, where the success depends on what one knows, not on what one has. A new economy appears with the capacity to generate, to store, to process and to apply effectively the knowledge, based on information, determining the companies productivity and competitiveness.The objective of this work is to understand the information management model of a technological research institute - CTGÁS (Gas Technology Center). The research has been done focused on the 5 main processes and the 15 support processes of the organization value chain , aiming to understand the information management in the organization based on Davenport´s Information Management model (1998). Therefore, it was necessary to identify how the necessary information for the organizational processes accomplishment are determined, obtained, distributed and used by the organization. The research can be classified as descriptive, regarding to its aims, and as a case study, related to the research ways. Interviews with the managers of the organization value chain processes have been carried through, with the objective to identify how they perceive the Information Management process that circulates in the organizational processes. Complementarily, a documentary research has been carried through, associated to the direct observation and procedures and actions follow up, involving the Information Management. The data treatment and analysis have been done from the authors theoretical support and from the managers interviews analysis, documents and processes observed by the researcher in the organization. It was noticed that the organization has raised its level of information needs that are not difficult to be determined and are satisfactorily obtained and distributed, although the majority of them are not structuralized, automatized or even classified regarding to its confidence. These peaces of information have good quality and are important, however they reflect a medium dependence on external and informal information, besides being used only in its great majority for people to know what and how to do something

Utilização de um ambiente virtual de aprendizagem: um estudo na perspectiva da prática docente

Advances related to information technology are visible and inherent to the management of contemporary organizations, regardless of industrial action. Synchronized with this dynamic, educational institutions are incorporating technological tools that assist its management and academic support to teachers in teaching and interaction with the students. Given that technological innovations are not always taken homogeneously and with the same degree of coverage, remain current and relevant studies on how these technologies are being used in academia. The objective of this research is to identify the usage profile of the functionality of a virtual learning environment related to teaching (undergraduate or postgraduate), demographic variables (age and gender) and institutional (time of admission and academic center of origin.) The methodology applied to the study is descriptive and quantitative. The research is characterized as census, covering all 2152 teachers of undergraduate and graduate students of the Federal University of Rio Grande do Norte, Brazil, who accessed the virtual classes of the Integrated Management of Academic Activities. The study findings revealed that there is a statistically significant difference regarding the use of these tools to teachers who work with undergraduate (49.3%) compared to graduate (6.6%). Regarding gender, women (40.1%) use the system more than men (38.5%). It was also observed that the younger teachers, aged 37 years, are the most active users (42.5%) of the Virtual Class with respect to their elders. For teachers with up to three years time of admission to the UFRN, the pattern of use is more advanced than those with more seniority, as well as the faculty of the Center for Science and Technology are the least likely to use the tools available in relation to other academic centers. It is hoped that with this study managers can direct actions to improve and expand the use of this environment by teachers

Precificação da energia eólica offshore no Brasil

Offshore wind power emits low amounts of gases, is renewable and has better performance than onshore due to its greater stability and higher wind power density, less visual and noise impact, among others. Brazil has a high capacity of generation, but has not yet developed any offshore projects. High costs are a strong impediment. This study is an effort towards pricing offshore resources through Livelized Cost of Energy - LCOE, which represents the minimum return to cover the costs of development, production and maintenance of a wind project. Initially LCOE was calculated for all Brazilian onshore wind farms listed at Bloomberg New Energy Finance R○, accounting for 71 farms. Then hypothetical offshore wind farms were created from the onshore farms, tripling the cost of generation, which is consistent with the literature, and estimating the offshore energy for two locations off the Brazilian coast using satellite data extracted from National Oceanic and Atmospheric Administration. The results demonstrate that offshore resources have the potential to significantly reduce the energy price due to the better performance of the wind at sea

Teoria de carteiras e a alocação de parques eólicos offshore

The consumption of energy on the planet is currently based on fossil fuels. They are responsible for adverse effects on the environment. Renewables propose solutions for this scenario, but must face issues related to the capacity of the power supply. Wind energy offshore emerging as a promising alternative. The speed and stability are greater winds over oceans, but the variability of these may cause inconvenience to the generation of electric power fluctuations. To reduce this, a combination of wind farms geographically distributed was proposed. The greater the distance between them, the lower the correlation between the wind velocity, increasing the likelihood that together achieve more stable power system with less fluctuations in power generation. The efficient use of production capacity of the wind park however, depends on their distribution in marine environments. The objective of this research was to analyze the optimal allocation of wind farms offshore on the east coast of the U.S. by Modern Portfolio Theory. The Modern Portfolio Theory was used so that the process of building portfolios of wind energy offshore contemplate the particularity of intermittency of wind, through calculations of return and risk of the production of wind farms. The research was conducted with 25.934 observations of energy produced by wind farms 11 hypothetical offshore, from the installation of 01 simulated ocean turbine with a capacity of 5 MW. The data show hourly time resolution and covers the period between January 1, 1998 until December 31, 2002. Through the Matlab R software, six were calculated minimum variance portfolios, each for a period of time distinct. Given the inequality of the variability of wind over time, set up four strategies rebalancing to evaluate the performance of the related portfolios, which enabled us to identify the most beneficial to the stability of the wind energy production offshore. The results showed that the production of wind energy for 1998, 1999, 2000 and 2001 should be considered by the portfolio weights calculated for the same periods, respectively. Energy data for 2002 should use the weights derived from the portfolio calculated in the previous time period. Finally, the production of wind energy in the period 1998-2002 should also be weighted by 1/11. It follows therefore that the portfolios found failed to show reduced levels of variability when compared to the individual production of wind farms hypothetical offshore

Análise do transcriptoma das glândulas venenosas do escorpião Tityus stigmurus

In Brazil, accidents with scorpions are considered of medical importance, not only by the high incidence, but also for the potentiality of the venom from some species in determining severe clinical conditions. Tityus stigmurus is a widely distributed scorpion species in Northeastern Brazil and known to cause severe human envenomations, inducing pain, hyposthesia, edema, erythema, paresthesia, headaches and vomiting. The present study uses a transcriptomic approach to characterize the molecular repertoire from the non-stimulated venom gland of Tityus stigmurus scorpion. A cDNA library was constructed and 540 clones were sequenced and grouped into 37 clusters, with more than one EST (expressed sequence tag) and 116 singlets. Forty-one percent of ESTs belong to recognized toxin-coding sequences, with antimicrobial toxins (AMP-like) the most abundant transcripts, followed by alfa KTx- like, beta KTx-like, beta NaTx-like and alfa NaTx-like. Our analysis indicated that 34% include other possible venom molecules , whose transcripts correspond to anionic peptides, hypothetical secreted peptides, metalloproteinases, cystein-rich peptides and lectins. Fifteen percent of ESTs are similar to cellular transcripts. Sequences without good matches corresponded to 11%. This investigation provides the first global view of cDNAs from Tityus stigmurus. This approach enables characterization of a large number of venom gland component molecules, which belong either to known or atypical types of venom peptides and proteins from the Buthidae family

Estudo da influência da temperatura de brasagem nas uniões zircônia/aço inox 304 utilizando metalização mecânica

Metal-Ceramic (M/C) Zirconia-stainless steel interfaces have been processed through brazing techniques due to the excellent combination of properties such as high temperature stability, high corrosion resistance and good mechanical properties. However, some M/C interfaces show some defects, like porosity and cracks results in the degradation of the interfaces, leading even to its total rupture. Most of time, those defects are associated with an improper brazing parameters selection to the M/C system. In this work, ZrO2 Y-TZP and ZrO2 Mg - PSZ were joint with the stainless steel grade 304 by brazing using a eutectic silver-copper (Ag28Cu) interlayer alloy with different thermal cycles. Ceramic surfaces were previous mechanically metallized with titanium to improve adhesion of the system. The effect of temperature on the M/C interface was studied. SEM-EDS and 3 point flexural bend test were performed to evaluate morphology, chemical composition and mechanical resistance of the M/C interfaces. Lower thermal cycle temperatures produced better results of mechanical resistance, and more regular/ homogeneous reaction layers between braze alloy and metal-ceramic surfaces. Also was proved the AgCu braze alloy activation in situ by titanium