Desempenho de um painel fotovoltaico de baixa tensão, acoplado ao protótipo de um conversor dc/dc topologia Booster

Low voltage solar panels increase the reliability of solar panels due to reduction of in series associations the configurations of photovoltaic cells. The low voltage generation requires DCDC converters devices with high efficiency, enabling raise and regulate the output voltage. This study analyzes the performance of a photovoltaic panel of Solarex, MSX model 77, configured to generate an open circuit voltage of 10.5 V, with load voltage of 8.5 V, with short circuit current of 9 A and a power of 77 W. The solar panel was assembled in the isolated photovoltaic system configuration, with and without energy storage as an interface with a DCDC converter, Booster topology. The converter was designed and fabricated using SMD (Surface Mounted Devices) technology IC (integrated circuit) that regulates its output voltage at 14.2 V, with an efficiency of 87% and providing the load a maximum power of 20.88 W. The system was installed and instrumented for measurement and acquisition of the following data: luminosities, average global radiation (data of INPE Instituto Nacional de Pesquisas Espaciais), solar panel and environment temperatures, solar panel and DC-DC converter output voltages, panel, inverter, and battery charge output currents. The photovoltaic system was initially tested in the laboratory (simulating its functioning in ideal conditions of operation) and then subjected to testing in real field conditions. The panel inclination angle was set at 5.5°, consistent with the latitude of Natal city. Factors such as climatic conditions (simultaneous variations of temperature, solar luminosities and ra diation on the panel), values of load resistance, lower limit of the maximum power required by the load (20.88 W) were predominant factors that panel does not operate with energy efficiency levels greater than 5 to 6%. The average converter efficiency designed in the field test reached 95%

Análise teórico-experimental do coeficiente de perfomance (COP) de um sistema de refrigeração por jato-compressão

The use of waste heat of energy conversion equipment to produce a cooling effect, consists currently in a very interesting way of efficiency improvement of energy systems. The present research has as intention the theoretical and experimental study of a new intermittent refrigeration system ejector cycle characteristics, with use of waste heat. Initially, was doing a bibliographical survey about the vapor ejector refrigeration system technology. In the following stage was doing a simulation of the corresponding thermodynamic cycle, with preliminarily intention to evaluate the performance of the system for different refrigerants fluids. On the basis of the results of the simulation were selected the refrigerant fluid and developed an experimental group of benches of the refrigeration system considered, where pressure and temperature sensory had been inserted in strategical points of the refrigeration archetype and connected to a computerized data acquisition system for measure the refrigerant fluid properties in the thermodynamic cycle. The test results obtained show good agreement with the literature

Análise de confiabilidade de uma bomba centrífuga: aplicação na injeção de água para recuperação de petróleo

The oil industry`s need to produce with maximum efficiency, not to mention the safety and the environment aspects, encourages the optimization of processes. It makes them look for a level of excellence in acquisition of equipment, ensuring the quality without prejudice security of facilities and peoples. Knowing the reliability of equipment and that this stands for a system is fundamental to the production strategy to seeks the maximum return on investment. The reliability analysis techniques have been increasingly applied in the industry as strategy for predicting failures likelihood ensuring the integrity of processes. Some reliability theories underlie the decisions to use stochastic calculations to estimate equipment failure. This dissertation proposes two techniques associating qualitative (through expertise opinion) and quantitative data (European North Sea oil companies fault database, Ored) applied on centrifugal pump to water injection system for secondary oil recovery on two scenarios. The data were processed in reliability commercial software. As a result of hybridization, it was possible to determine the pump life cycle and what impact on production if it fails. The technique guides the best maintenance policy - important tool for strategic decisions on asset management.

Avaliação de catalisadores a base de carbeto e nitreto de molibdênio na obtenção de lactitol via hidrogenação da lactose

Seeking a greater appreciation of cheese whey was developed to process the hydrogenation of lactose for the production of lactitol, a polyol with high added value, using the catalyst Ni / activated carbon (15% and 20% nickel), the nitride Mo2N, the bimetallic carbide Ni-Mo/ activated carbon and carbide Mo2C. After synthesis, the prepared catalysts were analyzed by MEV, XRD, laser granulometry and B.E.T. The reactor used in catalytic hydrogenation of lactose was the type of bed mud with a pressure (68 atm), temperature (120 oC) and stirring speed (500 rpm) remained constant during the experiments. The system operated in batch mode for the solid and liquid and semi-continuous to gas. Besides the nature of the catalyst, we studied the influence of pH of reaction medium for Mo2C carbide as well as evaluating the character of the protein inhibitor and chloride ions on the activity of catalysts Ni (20%)/Activated Carbon and bimetallic carbide Ni-Mo/Activated Carbon. The decrease in protein levels was performed by coagulation with chitosan and adsorption of chloride ions was performed by ion exchange resins. In the process of protein adsorption and chloride ions, the maximum percentage extracted was about 74% and 79% respectively. The micrographs of the powders of Mo2C and Mo2N presented in the form of homogeneous clusters, whereas for the catalysts supported on activated carbon, microporous structure proved impregnated with small particles indicating the presence of metal. The results showed high conversion of lactose to lactitol 90% for the catalyst Ni (20%)/Activated Carbon at pH 6 and 46% for the carbide Mo2C pH 8 (after addition of NH4OH) using the commercial lactose. Monitoring the evolution of the constituents present in the reaction medium was made by liquid chromatography. A kinetic model of heterogeneous Langmuir Hinshelwood type was developed which showed that the estimated constants based catalysts promoted carbide and nitride with a certain speed the adsorption, desorption and production of lactitol

Bio-óleo e biogás da degradação termoquímica de lodo de esgoto doméstico em cilindro rotativo

The objective of this study was to produce biofuels (bio-oil and gas) from the thermal treatment of sewage sludge in rotating cylinder, aiming industrial applications. The biomass was characterized by immediate and instrumental analysis (elemental analysis, scanning electron microscopy - SEM, X-ray diffraction, infrared spectroscopy and ICP-OES). A kinetic study on non-stationary regime was done to calculate the activation energy by Thermal Gravimetric Analysis evaluating thermochemical and thermocatalytic process of sludge, the latter being in the presence of USY zeolite. As expected, the activation energy evaluated by the mathematical model "Model-free kinetics" applying techniques isoconversionais was lowest for the catalytic tests (57.9 to 108.9 kJ/mol in the range of biomass conversion of 40 to 80%). The pyrolytic plant at a laboratory scale reactor consists of a rotating cylinder whose length is 100 cm with capable of processing up to 1 kg biomass/h. In the process of pyrolysis thermochemical were studied following parameters: temperature of reaction (500 to 600 ° C), flow rate of carrier gas (50 to 200 mL/min), frequency of rotation of centrifugation for condensation of bio-oil (20 to 30 Hz) and flow of biomass (4 and 22 g/min). Products obtained during the process (pyrolytic liquid, coal and gas) were characterized by classical and instrumental analytical techniques. The maximum yield of liquid pyrolytic was approximately 10.5% obtained in the conditions of temperature of 500 °C, centrifugation speed of 20 Hz, an inert gas flow of 200 mL/min and feeding of biomass 22 g/min. The highest yield obtained for the gas phase was 23.3% for the temperature of 600 °C, flow rate of 200 mL/min inert, frequency of rotation of the column of vapor condensation 30 Hz and flow of biomass of 22 g/min. The non-oxygenated aliphatic hydrocarbons were found in greater proportion in the bio-oil (55%) followed by aliphatic oxygenated (27%). The bio-oil had the following characteristics: pH 6.81, density between 1.05 and 1.09 g/mL, viscosity between 2.5 and 3.1 cSt and highest heating value between 16.91 and 17.85 MJ/ kg. The main components in the gas phase were: H2, CO, CO2 and CH4. Hydrogen was the main constituent of the gas mixture, with a yield of about 46.2% for a temperature of 600 ° C. Among the hydrocarbons formed, methane was found in higher yield (16.6%) for the temperature 520 oC. The solid phase obtained showed a high ash content (70%) due to the abundant presence of metals in coal, in particular iron, which was also present in bio-oil with a rate of 0.068% in the test performed at a temperature of 500 oC.

Distribuição de macroalgas lóticas de uma bacia de drenagem no Parque Nacional da Serra da Canastra, Minas Gerais, Brasil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A etnomatemática em uma cerâmica da região do Seridó/RN

This work has as objective to describe mathematical knowledge used as tools in the manufacture and marketing of tiles of red ceramic by potters of the Currais Novos village/ RN, located 250 km from the capital of Rio Grande do Norte. For us to reach our objective, we rely on conceptions ambrosianas of Ethnomatematics, besides of the qualitative research in an ethnographic approach. In the empirical part of the research, that went it accomplishes in the period from 2009 to 2012 in the Currais Novos Village, we support the following tools for data collection, semi-structured interviews, field diary, photographs, audio recordings and participant observations. In the analysis of the collected data, we can conclude that there are mathematical knowledge in the management of manufacture and marketing of tiles, often different from the academic mathematics, mainly in the wood cube, on cube of the clays, in the handler with the measures time, the count method , in the arrangement of tiles, in the preparation of the ceramic mass and sale of tiles. Theses knowledge were described and analyzed in the light of the theoretical Ethnomatematics, also supported in official documents, such as Parameters Nacional Curriculares. The analyzes of these knowledge generated subsidies for elaboration of an educational product - a proposal of didactic sequence destined to the Teaching of Mathematics in Elementary and Middle levels for the community schools and region, this proposal is in the Appendix to this work

Habilidades sociais educativas de mães separadas e sua relação com o comportamento de pré-escolares

Este estudo teve por objetivo: (a) caracterizar uma amostra de mães e filhos, em famílias separadas, quanto às suas habilidades sociais; (b) investigar relações entre as habilidades sociais educativas das mães e o comportamento das crianças; e (c) comparar grupo clínico e não-clínico quanto ao repertório comportamental. Participaram da pesquisa 43 mães de crianças de ambos os sexos, com idade entre quatro e seis anos. As participantes responderam a um Questionário Sociodemográfico, Roteiro de Entrevista de Habilidades Sociais Educativas Parentais, Child Behavior Checklist - CBCL, Questionário de Respostas Socialmente Habilidosas e Escala Infantil A2 de Rutter. Para análise de dados, empregaram-se os testes Spearman e Mann-Whitney. Os resultados mostraram que habilidades sociais educativas das mães estiveram relacionadas a habilidades sociais das crianças, enquanto práticas negativas foram relacionadas a problemas de comportamento. Discutem-se como as habilidades sociais maternas podem influenciar o comportamento dos filhos em famílias separadas.

Vulnerabilidade ao estresse no trabalho e percepção de suporte familiar em porteiros: um estudo correlacional

Este estudo objetivou avaliar e correlacionar os níveis de vulnerabilidade ao estresse no trabalho e percepção de suporte familiar em trabalhadores porteiros. Participaram 100 porteiros de uma empresa prestadora de serviços de médio porte. Utilizou-se o questionário de caracterização, a Escala de Vulnerabilidade ao Estresse no Trabalho (EVENT) e o Inventário de Percepção de Suporte Familiar (IPSF). A idade média dos participantes foi de 37,8 anos; trabalhavam na empresa, em torno de quatro anos e como porteiros, em média, há cinco anos. Os resultados mostraram uma pontuação média na medida de estresse geral da EVENT, sugerindo indicação de poucos estressores nesse grupo de porteiros. O IPSF também apresentou pontuação média, indicando que grande parte dos participantes possui percepção de bom suporte familiar. As análises mostraram correlações negativas fracas, porém estatisticamente significantes, entre a dimensão adaptação familiar do ipsf e as dimensões clima e funcionamento organizacional, pressão no trabalho e total da EVENT.

Avaliação da expressão da BMP -2/4 e BMPR-IA em Carcinoma Epidermóide Oral metastático e não metastático

The expression of bone morphogenetic proteins (BMPs) is altered in a variety of human canceres. The BMP-2/4 and BMPR-IA were recently shown to be overexpressed in high-risk premalignant and malignant lesions of oral epithelium. The present study analysed the expression of BMP-2/4 and BMPR-IA in Oral Squamous Cell Carcinoma (OSCC) such as their implications in disease prognostic using munohistochemistry. Ten cases of Oral Fibroepithelial Hiperplasia were selected as a control group. The experimental group included 16 cases of OSCC without metastases and 7 cases of OSCC metastatic. The presence or absence of nodal metastases was used as parameter to evaluated the disease prognostic. The results demonstrated weak immunoreactivity for BMP-2/4 and BMPR-IA in every case of the control group. In the cases of OSCC with metastases an overexpression of BMP-2/4 (71,4%) was observed while the BMPR-IA showed weak expression (85,7%). In the cases of OSCC without metastases BMP-2/4 (62,5%) and BMPR-IA showed strong immunostaining standing out an overexpression of the receptor in all the specimens. Observed statistical significance for correlation between the oral cancer prognostic and the staining intensity of the BMP-2/4 (p=0,002). There wasn t statistical significance for association between the staining intensity of the BMPR-IA and the disease prognostic (p<0,001). In conclusion, this findings suggest that the overexpression of BMP-2/4 associated with the loss of expression of the BMPR-IA in OSCC metastatic has prognostic relevance, as the loss of sensitivity to BMPs can be an indicative of metastases development in OSCC

Rendimento acadêmico e sua relação com os estilos de personalidade de estudantes universitários

One of the Psychology challenges, especially among the assessment and educational areas, is to understand and predict individual differences. In this context, this research aimed to verify the personality styles of students with high and low academic performance. The study included 236 university students from Petrolina-PE and Juazeiro-BA campus of the UNIVASF (Universidade Federal do Vale do São Francisco). They were uniformly distributed in four disciplines (medicine, psychology, administration and civil engineering), 10 students from each semester (five highest scores average students and five lowest scores average students) took place of the sample. The Millon Index Personality Styles (MIPS) was applied to analyze the personality/behavioral styles of the students. The MIPS is a 180 dichotomous (true/false) item scale. It was also developed and applied a questionnaire about the students characteristics and their academic information. Descriptive and central tendency statistics analysis (mean, standard deviation, frequency and percentage) were done to provide sample information. Then we performed a Mann-Whitney test in the overall sample and in each course and a factorial ANOVA. The results suggest that the university population is heterogeneous and there are significant differences (p <0.05) between the personality styles of students with high and low academic performance, when analyzing the overall sample and in courses of different areas of knowledge. Students of Medicine who have higher performance as personality styles prevalent the conformism and compliance, while students with lower income in this course, the styles are: innovation and discrepancy. Psychology students with higher income are more systematic and lower income students to score significantly on accommodation. The civil engineering students of the two groups differed only in personality style intuition, being such a style more characteristic of higher income students. Students of Management with higher yield stand out more in the style of the doubt and lower yields in these styles: individual, reflection and discrepancy. This study is correlational, but had an exploratory nature because there are no studies about this relationship in Brazil. Therefore, it provided a better understanding of the action characteristics of students with high and low academic performance. Further studies using the Big Five Personality Factors instruments are required because it is the most used model in understanding the influence of personality on students performance. This way, the relation between personality and academic performance will be better discussed. Otherwise, it will be possible to compare with the existing studies in the area

Sistemática integrativa de Cichlasoma orientale Kullander 1983 e Crenicichla menezesi Ploeg 1991 (Teleostei: Cichlidae) das bacias hidrográficas do Nordeste do Brasil

Understanding the historical and ecological relationships which are influent in current biological diversity is one of the most challenging tasks of evolutionary biology. Recent systematics emphasizes the need of integrative approaches to delimit different lineages and species. The northeastern Brazil, mostly placed in Caatinga biome, is characterized by a semi-arid weather, low precipitation and seasonal behavior of rivers. This region is regarded lacking as ichthyological knowledge and one of the most threatened by anthropic activities. Further, will be affected by a massive water diverpsion work that will transfer waters from São Francisco basin, to other major four basins: Jaguaribe, Apodi-Mossoró, Piranhas-Açu and Paraiba do Norte. Loss of diversity and richness, hibridizitation, community interactions changes, population homogenization, changes in water quality and flow regime, are examples of environmental impacts already related with similar works. The present study aims to investigate morphological and molecular variation of Cichlasoma orientale Kullander 1983 and Crenicichla menezesi Ploeg 1991, two cichlid species present in northeastern Brazil basins. Further, the study aims to evaluate the influence of geomorphological and climatic processes in this variation, and point some possible impacts of the artificial connectivity which can be brought by São Francisco interbasin water transfer to their population dynamics. Geometric morphometrics and phylogeographical analysis were used to investigate the populations from three different hydrological regions. Our results showed a significant morphological variation of populations from basins that are involved in the São Franscisco s diversion project, not related to an ancient separation between populations, emphasizing morphological variation which could represent a set of plastic responses to the variable hydrological regime in Northeastern Brazil. The role of plastical responses in naturally variable habitats as well as the potential disturbs that could be brought by the interbasin water transfer works are discussed here. Further, our molecular data allowed us to make inferences about species distribution and their taxonomy, and identification of a potential new species of Crenicichla for São Francisco river basin. Our data also allowed to identify some shared haplotypes for both species, which could be related to lineage sorting scenarios or recent gene flow between populations. However a strong structure in most of the pairwise comparisons between populations for both species was revealed. Climatic events such as Atlantic forest regression during the Pleistocene, sea level fluctuations and dispersion by paleorivers in the mouth of Apodi-Mossoró river, and neotectonic events regulating the connection between drainages are likely to have had a contribution for the actual lineages distribution in northeastern Brazil. Further, analysis of molecular variation (AMOVA and SAMOVA) showed that the actual basin s isolation is an important factor to molecular variation, in spite of the signal of recent contact between some basins. Different genetic diversity patterns between species could be related to multiple historic events of colonization, basins landscapes or biological differences. The present study represents the first effort of integrative systematics involving fish species of northeastern Brazil, and showed important morphological and molecular patterns which could be irrecoverably affected by the artificial connection that might be caused by the São Francisco interbasin water transfer

Estudo teórico-bioclimático da potencialidade de desenvolvimento do Aedes aegypti no estado do Rio Grande do Norte

In the current climate of global public health there is the emergence of urban dengue, a disease regarded as acute infectious fever. The disease annually, has affected millions of people worldwide, mostly in the range of the intertropical globe. The disease's main vector in urban areas, the Aedes aegypti mosquito. Recent studies indicate that the distribution of the insect vector of dengue in the geographical area is directly tied to the behavior of environmental restrictions that area, especially among those, the air temperature and relative humidity. From that context, the work aims to estimate and spatializing, monthly, for each municipality in the state of Rio Grande do Norte, the potential of biophysical conditions conducive to the development of Aedes aegypti. Yet, made use of the following methodology: collection of epidemiological data and climatological, Normal climatological, descriptive statistics (measures of central tendency and scatter), uniform distribution, estimation geostatistics and sufer program, version 8.0. The results flagged for a behavior very heterogeneous, both in space and in time, in the case of the potential of biophysical conditions conducive to the development of Aedes aegypti in the state of Rio Grande do Norte. Still, he noted that there is a tendency for lifting the potential of development for the entire state, from the month of January, ending in the month of April mainly in central and western portions of the state. By contrast, there is the permanence of increased potential for development in the eastern portion of the state. The latter record maximum potential in the month of July, resulting probability of greater than 70% have been favorable conditions for the development of Aedes aegypti in that area. In the period between the months of August to December, it is small potential for development of Aedes aegypti in all parts of the state

Inundações urbanas no semiarido nordestino: o caso da cidade de Pau dos Ferros - RN

The Apodi river basin, particularly within the snippet that crosses Pau dos Ferros - RN city, place anthropogenic actions that interfere in the dynamic environment by modifying the local landscape. The reflection of these actions can be seen in the floods that occur in rainy periods (February to may) virtually every year in the city. It is important to stress that the project of integration of the waters of the San Francisco basin with the northern basin of Northeastern will perennial the main channel of the river basin, and generate greater impacts in the region. This work sought to define a methodology able to delimit areas susceptible to flooding in cities of semiarid Northeast based on the Pau dos Ferros RN city. The dissertation is divided into two chapters and introduction. The introduction presents a theoretical frame based on discussion of the concept of risk, their main characteristics and subdivisions; floods; geotecnologies; Apodi River basin; municipal data Pau dos Ferros RN and design integration of Francisco basin with the northern basins Northeast. The first chapter evaluates the urban expansion process between 1987 and 2008, delimiting the flood areas and analyzes the relationship between urban growth and retention areas. The second chapter identifies the flood risk areas in the Pau dos Ferros city. The methodology used was based on tools of geographic information system GIS from software SPRING/INPE 5.1, as well as bibliographical, satellite images, aerial photographs and field activities. The results obtained enabled view the rapid expansion of the urban area of Pau dos Ferros, which has doubled in a period of 22 years. The population density checks with greater intensity in South-central portion of the city, in flood areas and not flood (Cap. 01). It was noted also that some neighborhoods along the River Apodi are susceptible to more instances of flooding ranging from minimum to maximum, while in neighborhoods near the Riacho Cajazeiras floods occur to a lesser extent because of altimetry higher and lower water volume. (Cap. 02). It is expected that this work will help in the preparation of flood risk municipal map subsidising managers in implementing public policies targeted to the softening of urban flood-related issues in Pau dos Ferros RN and serve as a model for mapping of other cities with similar characteristics analyzed in this work

Festa na escola e a autopoiese do lazer

This study shows the problem of school party and its relations with the perspective of leisure autopoiesis in the lives of students living in student housing. It has aimed to describe and interpret the most meaningful leisure experiences in daily life of a student housing and the ludopoietic processes for the humanescent self-education. From the theoretical assumptions supporting the development of this research have highlighted: Education by Freire (1996); Embodiment by Pierrakos (1990); Leisure by Dumazedier (1999); Party by Duvignaud (1983), Playful by Schiller (2002), Working by Freinet (1998), Autopoiesis by Maturana and Varela (2001), belonging to each day by Certeau (1994). A qualitative study adopts the principles of existential action research, in an ethnofenomenological perspective. As a methodology, we use the metaphor of sowing covering the planting, flowering, harvest and new planting. The scenario was to sow the Escola Agrícola de Jundiaí - RN. Twenty-five students residing in the school participated in research from 2007 to 2008, which involved more actively in the development of an extension project for the implementation of recreational and leisure experiences in that institution. The main instruments used for the construction of data collection were: participant observation, questionnaire, interview, game sand and photographs. The process of data analysis with the ethnofenomenological principles emphasized the following points: experientiality, indexicality, reflexivity, self-organizability, adoptability, archetypal and humanescenciality. New meanings of ludopoietic flowering of seed "party school" were revealed, and you can see the emergence of autopoietic leisure as a big green tree, able to sprout in soil properly fertilized to produce wonderful fruit of joie de vivre