1000 resultados para Vibração mecânica


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

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Patients who went through a Stroke may require mechanical ventilation (MV) in the acute phase of the disease and, on MV, they may show alterations in the respiratory mechanic. Physiotherapy techniques are applied in patients on MV to improve their respiratory mechanic. Thus, the purpose of this study was to evaluate the effects of the Respiratory Physiotherapy into the dynamic compliance (Cdyn), static compliance (Cst) and airway resistance (Rwa) in Stroke patients on MV. In order to do that, patients with Stroke diagnostic on MV were evaluated, before and after the use of Physiotherapy techniques (manual rib-cage compression, thoracic decompression, zero end expiratory pressure and suctioning). Cdyn, Cst and Rwa were the researched variables. Statistical Analysis was made using Paired T-Test with statistical significance with p-values no greater than 5%. Eleven patients were part of the study, with an average of 64,6±12,5 years old. Cdyn increased after physiotherapy from 29,3±16,1 ml/cmH2O to 33,8±16,7 ml/cmH2O (p=0,03). Cst also increased from 44,4±20,7 ml/cmH2O to 54,0±26,6 ml/cmH2O (p=0,024). No significant difference was detected for Rwa between the before and after moments (Before – 8,0±3,2 cmH2O/l/s, After – 7,3±2,25 cmH2O/l/s; p=0,45). It was possible to conclude that both dynamic and static compliance increased after physiotherapy, but the airway resistance did not increase in patients with stroke on mechanical ventilation.

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This review is intended to gather together recent studies that explore the effects of different types of noninvasive ventilation (NIV) on the autonomic nervous system, assessed through heart rate variability (HRV). A search for papers was conducted in the PubMed, PEDro, SciELO and Lilacs databases with the following descriptors: noninvasive ventilation, CPAP ventilation, intermittent positive pressure breathing and autonomic nervous system, for the period between 2008 and 2012. After eliminating papers not addressing the topic, we selected six studies, of which five applied NIV in CPAP mode and one used biphasic positive airway pressure. In general, the findings suggest that NIV promotes changes in autonomic modulation that are dependent on the conditions of the subjects analyzed and the time when these rates are assessed, meaning acute or long-term effects.

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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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This paper aims to survey data to analyze the productive capacity of a machining process of rolling bearings by methods-time measurement, in order to identify its bottlenecks and propose improvements in the system. The production times at the company are not known, the method of separation of operations and identification of its activities and the timing of production times and setup become points of departure for this paper. The results from this method of analysis provide clarity in identifying system weaknesses and by them it was possible to carry out the proposals for improvement in some process steps. The implementation of the improvements was not performed, but with the goals of this work was made possible to raise relevant information of the analyzed system

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This work is the production of particleboard of particles reconstituted from MDP (Medium Density Particleboard) adding particles in the inner layer of Mimosa Scarelli, popularly known as bracatinga, the ratios of 0%, 25%, 50%, 75% and 100%. The panel produced is composed of three layers, two external particles with smaller particle size and an inner layer composed of particles of larger particle sizes. Assays were performed based on physical and mechanical NBR 14.810/2006 for the determination of the board density, thickness swelling, water absorption, moisture content, bending strength, shear strength and residual moisture, and testing of particle size not existing in the standard cited. The results were analyzed and compared the results of the commercial boards made from 100% eucalyptus, based on the limits specified by the ABNT NBR 14.810/2006. The values of the tests were close to the normative specifications indicating positively the production of MDP with wood decay.

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Este trabalho propôs uma discussão crítica sobre os conceitos e fenômenos da Mecânica Quântica (MQ) empregados na explicação cientifíca que dá suporte quanto ao princípio de funcionamento de algumas terapias alternativas ou sobre a elaboração de seus respectivos medicamentos, em especial, Homeopatia e Cura Quântica. Essa discussão se faz importante para munir o leitor com argumentos sólidos calcados na teoria quântica e confrontá-los coma as ideias de simpatizantes leigos dessas terapias. Portanto, o trabalho visou descrever fatos históricos que tornaram possível a construção teórica da Mecânica Quântica, elaborou um resumo da loso a dominante que norteava o pensamento imediatamente anterior a MQ e o conflito que se seguiu em decorrência das implicações deste novo ramo da Física. Explorou o paradoxo EPR e o consequente teorema de John Bell sobre as desigualdades até chegar no experimento de Alain Aspect envolvendo laser para responder de forma prática e definitiva o paradoxo EPR. Finalmente, o trabalho apresentou um resumo das abordagens e argumentações defendidas pelos proponentes das terapias alternativas e confrontou com os conceitos da Mecânica Quântica, para enfim apresentar ao público um estudo científico sobre Homeopatia e Cura Quântica, e compreender os limites e equívocos empregados a essas terapias

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This work intends to perform the dimensioning of the Guaratinguetá’s Engineering College Baja SAE vehicle suspension system. To do so, concepts of suspension systems, human comfort limits to vibrations and automotive models for suspension vibration analyses are reviewed. On the development of this work descriptions of considerations specific for the vehicle object of this work are made as well as descriptions of the experiment made to determine the stiffness of the tire used. These concepts are applied through a computational routine that allows the dimensioning of springs and shock absorbers of both front and rear axles of a vehicle in a way to respect all the criteria showed during this work and visualize the system’s behavior when excited on different frequencies

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The adhesives used in the production of engineered boards have been object of study over the years in order to improve the properties of the boards with less energy consumption, lower production costs and reduced environmental impact. In addition to that, process variables may affect the properties of the board. The present study aimed to characterize sheets of plywood, manufactured with two types of adhesives, under two different pressing conditions. The adhesives used for the study were Phenol-formaldehyde and Polyurethane castor oil based. The pressure of pressing was varied in a range from 75 to 160 Bar, in order to verify how they influence the physical and mechanical properties of the board. The tests performed resulted in a conclusion that shows that the moister content of the veneers interferes on the physical and mechanical tests. In general, boards produced with polyurethane resin showed superior physical and mechanical results; although the ones produced with phenol formaldehyde at a pressure of 75 Bar had always equal or higher values, compared to what is found in literature

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Studies on new adhesives and resins for bonding wood and wood products are being conducted with the intention of improving their properties, taking into account a lower environmental impact. For this reason new formulations of polyvinyl acetate (PVA) adhesives have been developed, because they have no chemicals in its composition extremely polluting and harmful to health, as is the case of formaldehyde-based resins, which in turn are the most commonly used today for wood panels production. This study tested three different formulations of PVA adhesives, with different times and temperatures of pressing for the production of Eucalyptus sp. Plywood, coming up in satisfactory results with respect to shear strength at the bondline, which was higher for the PVA adhesives compared with urea-formaldehyde and phenol. The results of MOE and MOR were lower than those values of the panels produced with urea and phenol-formaldehyde, and the results of physical tests showed to be close to the panels produced with these same adhesives

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This study aims to analyze the feasibility of using predictive techniques like thermography, vibration analysis, eddy current, liquid penetrant, visual examination and ultrasound in equipment as batch reactors of the type used in a biodiesel production company. This study is based on: analysis of the practices of corrective and preventive maintenance commonly adopted in the company in question, the cost and time spent for such activities and the potential savings and revenue generation that can be after implementation of these techniques on the analysis of maintenance current

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We present a succinct review of the canonical formalism of classical mechanics, followed by a brief review of the main representations of quantum mechanics. We emphasize the formal similarities between the corresponding equations. We notice that these similarities contributed to the formulation of quantum mechanics. Of course, the driving force behind the search of any new physics is based on experimental evidence