942 resultados para protonic conduction
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Frontonasal dysplasia (FND) is a rare malformative complex affecting the frontal portion of the face, the eyes and the nose; it may occur singly or associated with other clinical signs. No systematic studies describing hearing in this condition were found. AIM: To evaluate hearing sensitivity and sound stimulus conduction from cochlea to brainstem in patients with clinical signs of FND. METHODS: 21 patients with isolated or syndromic FND were submitted to a clinical (otological/vestibular antecedents and otoscopy) and instrumental (pure tone and speech audiometry, tympanometry and brainstem auditory evoked response) hearing evaluation. DESIGN: A clinical, cross-sectional observational prospective study. RESULTS: Hearing thresholds were normal in 15 (70%) patients, abnormal in 5 (25%), mostly with conductive hearing loss; one patient did not cooperate with testing. The tympanometric curve was type A in 30 (72%) ears, type C in 5 (12%), type As in 4 (9%) and type B in 3 (7%). The auditory brainstem response (ABR) showed no abnormalities. CONCLUSION: Patients with FND showed no abnormalities in the auditory system from cochlea to brainstem in this study. Mild conductive hearing loss found in some is probably related to cleft palate. Further evaluation of hearing pathways at higher levels is recommended.
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Studies about structural integrity are very important when it desires to prevent disasters associated with flaws inherent in materials used in structural components. The welded joints in steel pipes used to conduction and distribution of oil and gas correspond to the regions most susceptible to flaw. Aiming to contribute to this research line, the present study was designed to assess experimentally the structural integrity of welded joints in steel pipes API 5L X70 used in pipeline systems. This assessment is given from tests of CTOD, whose aim is simulate in laboratory the real behaviour of crack from of his propagation on the welded joint obtained by high frequency electric resistance welding. In this case, the analyses are performed from specimens SE(B) obtained directly of steel pipe API 5L X70. The proposed methodology involves tests of CTOD at lower temperature, in order to assess the toughness of material in critical operation conditions. From performance of CTOD tests, was possible assess the toughness of welded joints in terms of quantity through CTOD parameter and in terms of quality from behaviour of curve load versus CMOD. In this study, also, sought to compare CTOD’s results obtained through rules ASTM E1820 (2008) and BS 7448 (1991). Although the two standards cited previously have adopted different parameters to calculated the value of CTOD, concluded that the values of CTOD tend to converge for a common value
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In this work, it was studied the thermal and fluid dynamic behavior from theorical and experimental point of view of a blast furnace tuyere. The tuyere is responsible for the hot air insuflation into the blast furnace. The parameter used in the comparison was the difference between the cooling water inlet and outlet temperatures. There were used forced convection correlations inside circular sections with adequations for non circular sections. Based on operations dates of flux and thermal loads it was possible to model numerically the tuyere, and, since it was obtained the wall temperatures, estimate the conduction and convection resistances and the heat flux through the walls in contact with the water. The total heat fluxes from wall to water were applied to the energy conservation equation where could be estimated the theorical temperature variation. Compared to the real value, the theorical value presented a difference of 0,2 °C. Considering that the boundary conditions around the tuyere are transitories and that your channels have some rugosity irregularities we can consider the estimation method for cooling system coherent with the real operational parameters
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This paper aims to study the thermal aspects involved in a liquid cooling system for processors, analyzing their competitiveness and efficiency across the fins and fan system usually used by personal computers, because electronic components become more potent and consequently current methods of cooling are becoming ineffective. The liquid cooling system and air cooling system have different heat transfer mechanisms that involve mainly convection and conduction heat transfer modes, and, furthermore, requires an analysis of fluid dynamics, which can evaluate the losses involved in the closed system, consisting in an exchanger heat pipe and water blocks in liquid cooling system or heat sink and turbo-axial fan in the air cooling system
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Induction heating is a process closely linked to the concepts of heat transfer. It also covers electromagnetic induction and effect of film. Many companies use this technology in their processes due to the high accuracy that can be obtained at temperatures induced. However the dominance of this technology is not common among Brazilian industries. This involves complex systems of equation and heat exchange in transient conduction, and convection and radiation losses. With this work we seek the ability to analyze which parameters influence over this process and the order of magnitude of time required for heating a cylindrical part
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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
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Because the high consumption of welded pipe for exploration and conduction oil and gas, optimization of manufacturing processes is necessary to obtain better productivity, efficiency and cost reduction. The objective of this study is to analyze the forms of heat transfer during the welding of pipes using longitudinal submerged arc process them to propose a model for the temperature distribution in the welded region. For this analysis are addressed as the heat transfer modes operate in the specified welding process and the necessary considerations for the mathematical model were obtained. The calculations were performed and the simulations needed to obtain the temperature distribution in the tube were carried out. Therefore, the practice was satisfactory and the results showed a range of temperatures along the pipe for a particular model and the future suggestions for improvement of this work
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Pós-graduação em Engenharia Elétrica - FEIS
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)