Estudo de causas de falhas em selos mecânicos de bombas centrífugas para circulação de óleo térmico

This study is about a heating line that uses thermal oil. It is located in a facility that produces interlayers used in cars windshields. A plastic resin is melted and is sent to a matrix called DIE where the interlayers are produced. The DIE needs to receive heat from the circulation of thermal oil in four different regions of its interior, to ensure the correct thickness of the interlayer. The thermal energy is provided by electric heaters and the flow of thermal oil is impelled by four mechanically sealed centrifugal pumps (one per region). The key point of this study is the fact that these four pumps of the system have reported successive failures in the mechanical seals. Apparently, a poorly designed project has burdened the system intermittently. The pumps operation condition is located in a region of low efficiency, according to the characteristic curves. This fact is the source of the noticeable reduced time between failures. Changes in the configuration of the facility and in the number of pumps will be proposed, aiming to achieve higher operational efficiency. The proposals will be mathematically analyzed according to the Hydraulic Institute criteria. At the same time, we will also keep focus on an in-depth study of a heating system structure, starting with a detailed approach for each component and discussion about its real need and economic viability. At the end of this paper it is shown that the gain in efficiency achieved with the new proposed configuration reflects not only in the reduction of maintenance costs, but also a potential improvement in energy efficiency. It is shown that these two aspects are closely related and together form the basis for the design of a reliable and efficient pumping system

Caracterização e validação de marcadores microssatélites para golfinhos-rotadores (Stenella longirostris)

A utilização de marcadores microssatélites tem auxiliado os programas de conservação, colaborando na definição de estratégias para proteção e manejo de populações de animais silvestres.Alguns microssatélites já foram desenvolvidos para algumas espécies de cetáceos, inclusive para os golfinhos-rotadores (Stenella longisrostris), aos quais recentemente foram publicados oito microssatélites espécie-específicos. A identificação e caracterização de novos SSR se faz necessário para ampliação das possibilidades de uso desses marcadores em estudos da Biologia e conservação dos golfinhos-rotadores. Deste modo, o presente projeto teve como objetivo dar continuidade a um trabalho de desenvolvimento de microssatélites para S. Longirostris iniciado no Departamento de Genética dessa Universidade, realizando a caracterização e validação de seis primers de microssatélites confeccionados para a espécie. O material tecido epidérmico de golfinhos-rotadores foi coletado no Arquipélago de Fernando de Noronha pelo método de raspagem da pele. A extração do DNA das amostras foi realizada com o uso da resina Chelex. Os primers de microssatélite foram avaliados em reação de PCR (Polymerase Chain Reaction) e validados na população natural. Dos seis primers avaliados quatro não apresentaram amplificação de produtos específicos (Slo5, Slo6, Slo7 e Slo12) e dois amplificaram bandas com tamanhos esperados (Slo8 e Slo10). O primer Slo10 foi monomórfico e o Slo8 apresentou-se polimórfico em gel de acrilamida. E, desta forma, os primers de microssatélites caracterizados neste trabalho contribuirão para a melhor compreensão da biologia da espécie, bem como no planejamento e monitoramento da população de Stenella longirostris

Influência do condicionamento ambiental sobre as propriedades viscoelásticas de compósitos aramida/epóxi

The increasing application of structural composites in the aerospace industry is mainly due to its low specific weight coupled with its excellent mechanical properties when in service. As a result of climatic variations that pass the aircraft is of paramount importance to study the influence of weathering on this type of material when subjected to such changes. The purpose of this work is to evaluate the mechanical behavior of specimens of kevlar fiber /epoxy matrix composites, by dynamic mechanical thermal analysis (DMA) and interlaminar shear strength tests (ILSS), after passing through three environmental conditioning: saline fog, hygrothermal and ultraviolet radiation. From the results, we concluded that the laminate was molded supplied homogeneously, not presenting problems such as porosity, delaminations or cracks inside. After a period of 625 hours of exposure to hygrothermal conditioning, we observed a 1,2% maximum of absorption of moisture. Samples subjected to the conditioning by UV irradiation (600 hours) and salt spray showed a reduction of about 24,30% and 32,30%, respectively, on the shear strength (ILSS). In DMA analysis is not observed significant changes on the glass transition temperature. However, when considering the storage modulus of the samples conditioned by UV radiation (1200 hours), salt spray and hygrothermal conditioning there is an increase of 5,34% , 7,19% and 5,57% respectively

Produção e utilização de material didático sobre fisiologia da audição e neurofisiologia

The teaching of hearing physiology requires an knowledge integration of Human Anatomy, Biophysics, more precisely Bioacoustics and Bioelectrogenesis, as well as Neurophysiology. Students present difficulty to build knowledge about functional mechanisms of sound conduction and sensory transduction, especially if the elements are not visible forms, as the middle and inner ear structures. To make the teaching about hearing physiology and sensory perception easier, was produced a set of didactical materials about the subject. At first, a resin model that faithfully describes the anatomical relationship of the ossicles with the tympanic membrane was developed. Subsequently, a second model that, besides illustrates the mechanism of acoustic impedance overcoming, also reveals how acoustic sensorial transduction occurs in inner ear, was designed and produced. In the third didactical model, are visualized, through students interaction, areas of the cerebral cortex that interpret the different sensory modalities. In addition, were created three educational videos about hearing problems and a site on Human Hearing Physiology, available on Institute of Biosciences website. The results of this course conclusion monograph are presented in the form of articles that were submitted to Journal Physics in the School and the Journal of the Nucleus of Teaching

Avaliação da membrana P81 como agente ligante da técnica de difusão em filmes finos por gradiente de concentração (DGT) para determinação de mercúrio em sistemas aquáticos

Worldwide environmental degradation is an undesirable byproduct resulting from the increasing demand for natural resources. Water sources are suffering intense contamination since they usually receive a huge amount of domestic and industrial effluents - which are mostly wasted without proper treatment - inserting a large number of pollutants in the environment, heavy metals included. Mercury holds great toxicological importance because, under some physicochemical conditions in a water environment, Hg (II) ion turns into methylated compounds stemming from this element, such as methylmercury CH3Hg, which is highly toxic for the aquatic community in which bioaccumulation occurs. Nowadays passive sampling techniques are being developed to enable the analytical procedures which are applied in environmental monitoring. Diffusive gradients in thin-films technique (DGT) has been proven an interesting tool for the determination of labile metal species due to its in situ application. The DGT technique consists of a piston-like device on which the following series of agents is disposed: a binding agent (conventionally Chelex 100 resin), a diffusive agent, usually a polyacrylamide gel, and a membrane filter. Nevertheless, the agents conventinally used for this technique don't usually show satisfactory results in mercury sampling. The main goal of this study was to evaluate the phosphate-treated cellulose membrane (Whatman P 81), an alternative material, as binding agent in the DGT to determine labile mercury fractions in aquatic systems. In this context, we conducted a study of the behavior of this material in relation with system variables, pH and ionic strength. Afterwards we performed immersions of the DGT devices in real and enriched samples and in situ aiming the determination of mercury

Estudo das interações entre proteína NS1 do hRSV e flavonóides utilizando métodos biofísicos

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

Inorganic elemental analysis and identification of residual monomers released from different glass ionomer cements in cell culture medium

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Crescimento e desenvolvimento econômico de Cingapura após a independência

This paper analyzes the growth and development of Singapore after its independence. For this, we made a historical analysis of the country, attributing importance in their geographic, economic, demographic, cultural and social. Singapore does not have a representative agricultural sector; its economy is based on manufacturing and the financial sector. The development of such activities was through strong planning policies and stringent regulatory institutions. Singapore economy has evolved from a trading post to a major financial center worldwide. Shows high rates of GDP per capita, which is $ 50,000 in 2011. This country has the world's busiest port for container handling. Thus, industries are based on activities with high added value and attraction of foreign companies was due to the stability of the country, which helped the growth of it

Estudo da superfície de fibras de carbono após tratamento de implantação iônica por imersão em plasma (3IP)

In this work, plasma immersion ion implantation (PIII) treatments of carbon fibers (CFs) were performed in order to induce modifications of chemical and physical properties of the CF surface aimed to improve the performance of thermoplastic composite. The samples to be treated were immersed in nitrogen or air glow discharge plasma and pulsed at −3.0 kV for 2.0, 5.0, 10.0, and 15.0 min. After PIII processing, the specimens were characterized by atomic force microscopy (AFM), scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). After CFs treatments, the CF/Polypropylene (PP) composites were produced by hot pressing method. Surface morphology of as-received CFs exhibited some scratches aligned along the fibers due to the fiber manufacturing process. After both treatments, these features became deeper, and also, a number of small particles nonuniformly distributed on the fiber surface can be observed. These particles are product of CF surface sputtering during the PIII treatment, which removes the epoxy layer that covers as-received samples. AFM analyses of CF samples treated with nitrogen depicted a large increase of the surface roughness (Rrms value approximately six times higher than that of the untreated sample). The increase of the roughness was also observed for samples treated by air PIII. Raman spectra of all samples presented the characteristic D- and G-bands at approximately 1355 and 1582 cm−1, respectively. Analysis of the surface chemical composition provided by the XPS showed that nitrogen and oxygen were incorporated onto the surface. The polar radicals formed on the surface lead to increasing of the CF surface energy. Both the modification of surface roughness and the surface oxidation contributed for the enhancement of CF adhesion to the polymeric matrix. These features were confirmed ... (Complete abstract click electronic access below)

Análise das microdeformações geradas ao redor de implantes de hexágono externo sob a aplicação de cargas verticais em pilares microunit retos e angulados

Pós-graduação em Odontologia Restauradora - ICT

Confecção e avaliação de chapas de madeira aglomerada com aproveitamento de resíduos de marcenaria industrial

Pós-graduação em Engenharia Civil - FEIS

Estudo clínico longitudinal de dentes restaurados com sistemas cerâmicos livres de metal: estudo prospectivo sobre a hipersensibilidade dental pós-operatória

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito de protocolos de cimentação na carga de fratura para uma cerâmica de dissilicato de lítio

Pós-graduação em Odontologia Restauradora - ICT

Análise do processo de fresamento de MDF em centro de usinagem CNC

Pós-graduação em Engenharia Mecânica - FEG

Resistência à tração de coroas de NiCr cimentadas sobre munhões de liga de titânio, com 4 diferentes tipos de cimentos

In this work of tensile strength was evaluated the efficacy of 4 cements (S. S. White zinc phoshate, Ketac Cem Easymix glass ionomer, RelyX Luting 2 composite resin/glass ionomer and Panavia 21 TC special acrylic resin) used to fix NiCr crowns to usinated titanium alloy abutments. Were used 40 abutments distributed in groups of 10 elements, to each material. The mechanical essays were developed at a MTS 810 universal machine, adjusted to a 0.5 mm/m velocity. The ANOVA applied to data pointed out the existence of significant differences between groups; the subsequent Tukey´s test (p<0.05) also detected significant differences, except at comparisons of phosphate versus RelyX and phosphate versus Ketac Cem. The better performance was presented by Panavia 21 (1,127.996 N); RelyX (478.197 N) showed itself similar only to phosphate (430.662 N), wich had a performance similar to that of Ketac Cem (227.705 N).