896 resultados para Continuous synthesis by solution combustion


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ABSTRACT: In Guajará bay, mouth of the Amazon River, is located the capital of Pará state (Belém) and its metropolitan area. Exists in this area an intense boat traffic, as well as transportation and sale of fuels in floating docks and activities related to the storage and transportation of oil in Miramar Petrochemical Terminal (TEMIR). Small spills and discharges of oil in water can serve as sources of pollution by polycyclic aromatic hydrocarbons (PAHs). PAHs are organic compounds generated by incomplete combustion of organic matter (OM) and are among the contaminants of most interest in environmental studies due to their mutagenic and carcinogenic potential. One way to detect and evaluate the impact of PAHs in an environment is using biomonitors, however the qualitative and quantitative analysis in sediments are most widely used. This study aimed to evaluate, by Gas Chromatography/Mass Spectrometry (GC/MS), the 16 PAHs considered as priority by the Environmental Protection Agency of the United States in sediments and benthic organisms (Namalicastys abiuma) of TEMIR. Field expeditions were carried out in December 2012, March, May and June 2013 representing the dried, wet (two samples) and dried seasons successively. Fine sediments levels dominated in both sampling periods and the %Fines in Guajará bays has a direct relationship to the %OM. In relation to the 16 PAHs studied, 10 of them were detected in the wet season sediments samples and 8 in the dried season. Even with a low diversity of aromatic compounds, sediment samples of the dried season presented greater ΣHPAs (1.351,43 ng g-1) than the sediments of the wet season (263,99 ng g-1), which can be related to the increased hydrodynamic in Guajará bay this last period. Correlation analysis indicated that ΣHPAs not seem to be influenced by %Fine and %OM. Benzo(a)pyrene accounted for 87% of ΣHPAs during the wet season, the other PAHs showed percentage ≤ 3%. During the other period stood out: pyrene (18% of ΣHPAs) fluoranthene (16%), the chrysene, benzo(b)fluoranthene (15%) and benzo(a)pyrene (11%). The use of the geochemical reason to interpret likely sources of PAHs indicated that there is a predominance of aromatics from pyrolytic origin in TEMIR. The activities that may be responsible for the PAHs levels observed in sediments and benthic organisms in TEMIR are the discharge of untreated domestic sewage and the emissions of particulates from cars and small/medium boats. The ΣHPAs seems to influence the density of polychaetes because a reduction of about 50% in the number of organisms was observed during the dry season when there was the greater amount of ΣHPAs in their body structure. Among the 16 PAHs studied, 11 were detected in the polychaetes during the dry season (ΣHPAsMED = 848,71 ng g-1) and 10 in the wet season (ΣHPAsMED = 141,85 ng g-1). Were highlighted during the dried season: indeno(1,2,3-c,d)pyrene (47%) and pyrene (23%). While in the wet season: pyrene (23%), chrysene (17%), fluorene (17%) and fluoranthene (13%). The %Rec obtained was >>100% indicating a matrix effect and reducing the quantitative accuracy of results. The use of the polychaete N. abiuma as biomonitor of pollution by PAHs in estuaries not seem to be effective when the sample period is limited, because collecting it requires a great effort to obtain a small amount of mass and it still results in a matrix effect in the chromatographic analysis (method %Rec >> 100%) that may not be corrected due to the restricted availability of sample mass. Studies with a larger number of samples, enabling depth statistical analysis, and covering other collection points in Guajará bay are required to prove mathematically that has been stated in this dissertation.

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Pós-graduação em Química - IQ

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Pós-graduação em Ginecologia, Obstetrícia e Mastologia - FMB

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Aim: Injury of tendons contained within a synovial environment, such as joint, bursa or tendon sheath, frequently fails to heal and releases matrix proteins into the synovial fluid, driving inflammation. This study investigated the effectiveness of cells to seal tendon surfaces and provoke matrix synthesis as a possible effective injectable therapy. Materials & methods: Equine flexor tendon explants were cultured overnight in suspensions of bone marrow and synovium-derived mesenchymal stems cells and, as controls, two sources of fibroblasts, derived from tendon and skin, which adhered to the explants. Release of the most abundant tendon extracellular matrix proteins into the media was assayed, along with specific matrix proteins synthesis by real-time PCR. Results: Release of extracellular matrix proteins was influenced by the coating cell type. Fibroblasts from skin and tendon appeared less capable of preventing the release of matrix proteins than mesenchymal stems cells. Conclusion: The source of cell is an important consideration for cell therapy.

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Lithium ion conducting polymer electrolytes based on polyvinyl Alcohol (PVA-OH) complexed with salt Li2SO4 and different weight percent ratios of PEG(400) plasticizer have been prepared by solution cast technique using deionized water as solvent. The thermogravimetric analysis (TGA) showed that the thermal stability of the materials depended on the plasticizer content. The FTIR study confirmed the polymer salt complex formation. The modulus spectra indicated the non-Debye nature of the material; a dominant relaxation process is visible being associated with the dynamic glass transition, relaxation-a. The maximum of each peak is shifted to higher frequencies as the plasticizer increases due to an enhancement of dipolar mobility in the origin of cooperative motions. A power law frequency dependence of the real part of the electrical conductivity is observed, which is characteristic of the effects of ion-ion and/or ion-chain correlations in ion motion. This variation is well fitted to a Jonscher's expression.

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Introduction: The neuropsicomotor development could be negatively affected by several factors occurred in the pre, peri and pos natal period. The early stimulation is implemented by a set of dynamic activities which aim the child development according to the child’s phase. Objective: The purpose of this study was to analyze the functional skills acquisition in the self care area in children with development delay. Participated of this study 9 caregiver of children aged of 0 to 3 years with delay neuropsicomotor. Method: For the data collect was used the self-care area of the Pediatric Evaluation of Disability Inventory (PEDI) in the version adapted for Brazil. The data collect was performed in two different stages, with an interval of 6 months between the collects. The raw score were transformed in continuous score by the Rasch statistics, then was applied the Shapiro-Wilk and t-student test. Results: The participants obtained a signifi cant higher score in the second stage than in the fi rst (p<0,01). Conclusion: The results of the present study suggests that the early stimulation could be an important intervention in the process of self-care skills acquisition in children with neuropsicomotor delay.

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Modificações na composição química e no processamento termomecânico têm sido algumas das várias alternativas estudadas, para melhorar o desempenho de ligas de alumínio tradicionais. Neste trabalho foi modificada a composição de uma liga Al-Mn-Mg do tipo AA 3104, endurecível por deformação, adicionando-se diversos teores de zinco, transformando-a numa liga Al-Mn-Mg(Zn), endurecível por precipitação. O objetivo foi estudar e quantificar os efeitos do zinco sobre o processamento termomecânico e as propriedades mecânicas da liga modificada. Ligas com teores de zinco entre 0,03 a 1,52% foram fundidas e processadas obtendo-se um encruamento semelhante a condição H-19 industrial, denominada rota R. Ligas com teores de zinco entre 1,14 a 2,17% foram fundidas e processadas segundo três diferentes rotas: na rota S, o recozimento da rota R foi substituído por solubilização antes da laminação a frio; nas rotas E3H e E6H, as tiras laminadas a frio foram envelhecidas em dois estágios: 121°C por três horas para as duas rotas, mais três horas para a rota E3H e seis para a rota EH a 163°. A tensão de escoamento (SIGMA IND E) e a resistência à tração (SIGMA IND T) para a rota R aumentaram da ordem de 18% e 19% respectivamente, com o aumento do teor de zinco, enquanto o alongamento (E) permaneceu em torno de 4,5%. As propriedades mecânicas (SIGMA IND E SIGMA T E ) AUMENTARAM EM TORNO DE 25%, 31% E 27%, respectivamente, para a rota S. Considerando concentrações aproximadamente iguais de zinco, não foram verificadas diferenças significativas para (SIGMA E SIGMA T), entre as rotas R E S, no entanto, a rota S apresentou alongamento médio maior que a rota R da ordem 44%. Os menores valores de (SIGMA IND E SIGMA IND T) e os maiores valores de E foram obtidos para a rota E6H.

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The discussions about the energy rationalization are gaining more and more space on the everyday of engineers and other professionals in the field of energy. A greater focus is being tied to commercial buildings, because they are one of the biggest responsible for the high energetic expenditure according to the National Energetic Balance, especially by the use of air conditioners for the people’s thermal comfort. Such finding made INMETRO to develop a building labeling procedure through th National Program of Electric Energy Conservation in Buildings; by means of this systematic, the built areas are classified by levels that go from A(the best) to E(the worst), taking into account envelopment, illumination system and air conditioning. A bonus process based on water rationalization, use of renewable energy sources, cogeneration systems or technical innovations, allows the classification to be changed up to one level. A study made exactly on a commercial building, the building of Foundation for Technological and Scientific Development located inside of the College of Engineering of Guaratinguetá, sought to identify technical/economic alternatives for the building certification and appealed to the bonus based on water rationalization. The present study is based on analysis of deploying a cogeneration system formed by internal combustion engine and an absorption refrigeration system as bonus alternative, so that the costs are analyzed regarding energy consumption and use of the motor. With the calculations and results, the viability of the building to receive a bonus from INMETRO through its National Program for Energy Conservation in Buildings is studied and concluded from this study whether or not you can get a better level of energy efficiency for the building in question... (Complete abstract click electronic access below)

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The study of ceramic materials is constantly evolving, especially in research related to advanced ceramics. Once these have many applications, this paper relates to synthesis by solid state reaction of calcium copper titanate (CCTO) ceramic material means doping with strontium. The powders were characterized using thermal analysis techniques such as TG (thermogravimetry), DTA (differencial thermal analysis), dilatometry, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The compositions have submitted weight loss at around 6% with respect to carbonates used, and was attributed a temperature of 950° C to perform the calcination according to thermogravimetric analysis. After the process of calcination and milling, the particles presented approximately spherical shapes and high percentages of substitution Ca2+ with Sr2+ was evident by the presence of necks between to particles due to the milling calcination. Analyses with Energy Dispersive Spectroscopy (EDS) showed stoichiometries in different samples very similar to the theoretical stoichiometry

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Pós-graduação em Letras - IBILCE

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Pós-graduação em Ciência dos Materiais - FEIS

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This work intends to know the most types of ignition systems, studying its history, the way it works, applications and some examples. The assembly of a distributor less ignition system is also required. All vehicles powered by internal combustion engines need an ignition system that allows this engine to ignite the air-fuel mixture using its ignition system in the best possible manner. The main goal of an ignition system is to obtain a spark having enough energy to start the chemical reaction of the oxygen and the fuel. It took a study dealing with the various types of ignition systems since their creation at the beginning of the last century until 2015. The work starts studying the high tension magneto ignition system and later together with the low tension ignition system, going on with the conventional ignition system and finally accomplishing with the various types of electronic ignition systems. It was studied and implemented an electronic circuit to power a double spark ignition system also known as wasted spark ignition system. This circuit was assembled with an electric pulse generator and powered mechanically by a dc electric motor of the variable rpm type