872 resultados para Ruído Coerente


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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Estudos Literários - FCLAR

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PURPOSE: to analyze the levels of noise emitted by nationally-sold toys for use by children from 1 to 5 year old; to compare the values among the toys with and without the seal of Inmetro (National Institute of Metrology, Standardization and Industrial Quality) and to analyze the sound spectrum of toys, in order to identify the area of the cochlea that may be more affected by these noises. METHOD: measurements were performed on 20 sound toys (10 with the seal of the Inmetro and 10 without the seal) with the use of digital sound level meter in an acoustically treated room, and the sound analysis was performed using the Praat program. RESULTS: toys placed at 2.5 cm from the equipment with the seal of the Inmetro had an intensity ranging from 61.50 to 91.55 dB (A) and from 69.75 to 95.05 dB (C), positioned at 25 cm ranged from 58.3 to 79.85 dB (A) and from 62.50 to 83.65 dB (C). The results of the toys without warranty stamps placed at 2.5 cm ranged from 67.45 to 94.30 dB (A) and 65.4 to 99.50 dB (C) and the distance of 25 cm recorded from 61. 30 to 87.45 dB (A) and 63.75 to 97.60 dB (C), so that the findings demonstrated that there are noisy toys that go beyond the values recommended by the current legislation in both groups, with and without warranty stamps . CONCLUSION: the toys without the seal of Inmetro showed intensities values significantly higher than the other group, offering more risk to the children s hearing health.

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O presente trabalho realiza um estudo referente à Geometria Tridimensional, no que tange a sua metodologia apresentada nos livros didáticos de Matemática. Esse instrumento tem passado por um processo de avaliação mais rigoroso nas últimas décadas pelos órgãos governamentais para a promoção do livro com qualidade o que é importante, porém uma análise crítica de seus conteúdos é essencial para que esse instrumento torne-se adequado a cada realidade e um aliado no planejamento do educador no processo de ensino e aprendizagem da Geometria. Essa disciplina é considerada por vários autores e especialista da educação como um conhecimento muito pertinente para a formação integral do aluno, ao proporcionar o desenvolvimento do raciocínio visual, espacial e lógico, abrangendo também a formação cultural e profissional. Nesse sentido, considerando a importância da escolha de um livro adequado e coerente para a qualidade desse ensino, objetivouse com esse estudo realizar uma análise e reflexão sobre os conteúdos da Geometria Tridimensional apresentada em dois livros didáticos de matemática do 5º ano do ensino fundamental submetidos aos critérios eliminatórios do Programa Nacional do Livro Didático - PNLD (2013) e aprovado pelo Ministério da Educação. Mediante levantamento bibliográfico da literatura pertinente e análise de documentos oficiais foi possível verificar que os mesmos apresentaram progressos em alguns aspectos atendendo de forma parcial as propostas atuais para esse ensino demonstrando que ainda precisam evoluir

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Pós-graduação em Agronomia (Irrigação e Drenagem) - FCA

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The development of electrocatalysts for the oxidation of methanol and ethanol is very important, because these alcohols may be used in the anode fuel cells which convert chemical energy directly into electrical energy with high efficiency, cleanly and with low noise. Thus, this study reports to the synthesis of nanocatalysts of PtAu supported on carbon by microemulsion method. The physical characterization of these catalysts is performed through the techniques of X-ray diffraction and transmission electron microscopy. The catalytic activity of the prepared materials was studied using conventional electrochemical techniques and also the technique of spectro-electrochemical in situ FTIR, which allows identification of intermediates and products of the reactions. From the x-ray diffraction, it was observed that the thermal treatment applied to catalysts favored incorporation of Au into the crystal lattice of Pt,that is, increased the formation of PtAu alloy. Micrographs indicated particle size about 3 nm to materials not heat treated and 9 nm to materials subjected to thermal treatment (heating at 150 ° C for 1h and 30 min in argon atmosphere). Current density oxidation of methanol on PtAu / C were superior to pure platinum. Spectroscopic results indicated the presence of formate in solution in 50:50 and the composition showed bands for CO2, indicating complete oxidation, in lower potential. During ethanol oxidation on the catalyst PtAu, the main product formed was acetate, product of incomplete oxidation. The good performance for methanol oxidation can be attributed to large amounts of oxygen species adsorbed on the catalyst surface, or an electronic effect.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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During clinical routine, the orthodontist uses several materials, which include metallic alloys in the form of metallic wires. However, it is necessary that the professional has some knowledge of the properties of those wires. Different types of wires are commercially available: stainless steel wires, chrome-cobalt wires, nickel-titanium wires and beta-titanium wires. Among the nickel-titanium wires, there are three subdivisions: a conventional alloy and two superelastic alloys. The superelasticity, associated to the effect of form memory, is a property used in orthodontics to initiate the dental movement in the first phase of the orthodontic treatment. This property is considered to be biologically compatible with the effective dental movement. These wires are available at the market in different transformation temperatures, and they offer the best adaptation in the groove of the bracket, simplicity and a faster treatment. However, they present little formability, and they don’t accept solder. They are also more onerous than other wires. Moreover, the low rigidity of these wires doesn’t allow them to be used for the retraction of the anterior teeth or closing of spaces. Therefore, the coherent use of superelastic orthodontic wires is recommended, accompanied by a detailed diagnosis and planning, so the result will be an efficient orthodontic correction, accomplished in a shorter period of time.

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The lead contamination in children has been the subject of research in the field of public health. This study evaluated the academic performance of 102 children from first to fourth grade. The subjects were divided into two groups. The first group was composed of 34 children without lead poisoning or with poison at levels lower than 5 µg/dl. The second group was composed of 68 children with blood lead levels between 10 and 40 µg/ dl. The instruments used to evaluate the academic performance were anamnesis and a scholarly performance test called Teste de Desempenho Escolar, TDE. The results indicated better academic performances from the second group with significant differences in arithmetic, reading and general scores. In a comparison between genders, the girls had better performances than the boys. These results were consistent with the parents’ perception in anamnesis. Although other variables were present, the data showed great academic damage for children with higher leadpoison. These outcomes require political policies to control contamination and intervention in this population.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Serviço Social - FCHS

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Among the harmful health agents, it is given to the noise, one of the most present in urban and social environments. There are efficient measures to control the noise and the auricular Individual Protection Equipment (IPEa) is the most used. It has been observed the shortage in the comfortable and functional individual auditory protection products, related to durability, face to the efficiency right of the equipment. The main objective of this study was to recognize if there is effectiveness loss toward the used time on the Auditory Equipment, intra-auricular Individual Protection, of foam (3M), model 1110. It has been verified that the equipments suffer efficiency alteration according to the time of use, and the material consuming initiates reliable loss, mainly in audible frequencies going up to 100Hz, and from 16 days for sonorous pressure suffered started in 101dB 20Hz. For sonorous pressure suffered from 107dB to 20Hz, the reliable loss for the usage was of 8 days. The IPEas do not lose effectiveness on important attenuation by the daily use in frequencies from 1KHz until 20KHz. It has been concluded that there is effectiveness loss, according to the daily and frequent use of the IPEa studied.

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This article aims to map the development of the market of digital TV in Brazil, under the aspect of the relation among culture, technology and politics. We start with a history of analog TV, since its inception, showing matrices of Brazilian TV. Then we try to show current conditions of the TV market in the country, its ambiguous relation with the internet and the possible ways for survival of open digital TV: respect for cultural diversity, the observation of the habits acquired from other media, the consistent use of digital language and the modifi cation of public policies in favor of the collective and not protectionism of large private communication companies.