Propriedades físicas e mecânicas de cimentos de ionômero de vidro encapsulados e não encapsulados

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência da miliamperagem sobre a qualidade do diagnóstico das fraturas radiculares por meio de tomografia computadorizada de feixe cônico: estudo in vitro

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação de lubrificantes para aplicação em componentes mecânicos pelo método de compressão do anel

The current lubricants are getting better with advancing technology and more specific to each case of application. Its use is directly linked to the level of waste by friction generated between objects in direct contact and it is essential to promote greater durability of mechanical components. This study refers to behavioral assessment of some types of lubricants and rank among them which one presents the lowest friction between metal components. For this work, will be used the method of ring compression test (RCT), after performed tests and analyzed the results, will be possible to report which lubricant will bring the best reduction in friction. The need for this work was given initially by the observation that some mechanical projects developed at FEG does not conduct in-depth studies the lubricants used. Therefore this study aims to provide better support to these projects. In this work were used five different lubricants, three oils and two greases.

Retorque de parafusos de pilares protéticos com recobrimento de carbono tipo diamante: uma análise da manutenção do torque após fadiga mecânica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise de integridade física de barragens de terra a partir da integração do método geofísico da eletrorresistividade com ensaios geotécnicos

Pós-graduação em Geociências e Meio Ambiente - IGCE

Colunas de Winogradsky com águas contaminadas por petróleo e derivados monitoradas por ensaios ecotoxicológicos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo da resistência à corrosão de ligas Ni-Cr-Mo-Ta E Ni-Cr-Mo-W em solução NaF 0,08 mol/L, pH 4,7 para aplicações odontológicas

A large number of metal alloys are used in Dentistry for the manufacture of fixed and removable dentures. In the oral cavity, these structures are exposed to a chemically aggressive medium, like saliva and mechanical efforts, like mastication. In addition, acidic solutions containing fluoride ions are also frequently used in dental treatments to prevent dental plates and decays development. In this context, it was considered important to investigate the influence that a fourth element could exert when added to the ternary alloy Ni-Cr-Mo, largely used in Brazil. Therefore, electrochemical tests were done to evaluate the resistance to corrosion of quaternary alloy 65Ni-25Cr-5Mo-5Ta and 65Ni-25Cr-5Mo-5W in NaF solution 0,08mol / L, pH = 4.7. For greater understanding the microstructure and morphology of alloys were studied, through metallographic analysis, using optics microscopy and electron microscopy scanning. For the electrochemical tests were applied techniques traditionally used in corrosion researches, such as: potential measures in open circuit (OCP) and cyclic polarization (CP). It was found that both quaternary alloys showed very similar results. Comparing these quaternary alloys with the ternary 65Ni-25Cr-10Mo, it was found that the quaternary alloys exhibit greater resistance to corrosion, in other words, less passivation current density than the ternary alloy, showing that it is advantageous to add a fourth element in the alloy

Concepção detalhada de uma bancada para simular esforços mecânicos em colunas de perfuração

In this work we study the construction of a test rig made to simulate the Mechanical efforts in wich a drillstring is submitted. The model is based on the rig built at IDS, Germany. There are some fault liabilities while doing the project of the axis. Therefore it's important to analyze and take knowledge of this efforts in order to predict failures like rupture or fatigue collapse. The main objective of this theis is to show the operating principle of the test rig and it's construction. The accomplished study allow us to predict the drillstring behavior and from the economic point of view that is very important because failures results in equipments maintenance that requires time and money causing prejudice to the company. Using SolidWorks, a simulation software, the thesis approaches all the mechanical parts required for it's construction as well as it's working principle. Acquisition sensors like strain gauges, accelerometer, and torque transductor were also used in this model. The objective of this thesis is to create a simulation model to be eventually at FEG(UNESP). During the development of the study, it was possible to learn more about the drilling process and the mechanical efforts in which the drill pipe is submitted. The accomplished contributed with knowledge for the student in the drilling process area. Also during the development of the study it was possible to have contact with different areas of engineering but the study is specifically directed to the construction of the test rig. Therefore the main theme of this thesis is to show the operating principle of the test rig and it's construction

Projeto de adaptação do sistema de injeção do túnel transônico para ensaios em bocais de foguete

In this work, the project of a new experimental facility to be installed at the Aerodynamics Division of the Institute of Aeronautics and Space is presented. This new facility will provide means to perform experimental campaigns to analyze the flow behavior at different rocket nozzle concepts using cold gas that will be obtained from a modification of the Pilot Transonic Wind Tunnel air system. The new installation will enable less expensive experiments in a more secure environment, since the cold gas experimental procedures do not demand fuel storage and burn and security procedures are much less severe. Furthermore, experiments can be carried with different types of sensors, commonly used in wind tunnel tests. Also, the optical access is facilitated enabling the use of optical techniques for the characterization of flow properties inside the nozzles, such as pressure and temperature sensitive painting. The full project design and the operation conditions will be showed, as also some technical considerations about the flor behavior in the facility

Verificação de pilares metálicos compostos constituídos por perfis formados a frio por meio de programa computacional

In this work, we discuss the procedures adopted for the design of built-up columns (laced and battened columns). Built-up columns are widely used in steel construction generally when the compression forces are relatively low and the column buckling lengths are large. They are commonly used in industrial buildings, for example, as posts for cladding, or as columns supporting a crane girder. Unlike columns with full section, in the case of built-up columns, it is necessary to evaluate the shear stiffness. In fact, the shear strength leads to a significant reduction of the critical load. In the context of this work, the components of the columns (chords, diagonals, posts, etc.) are formed by cold-formed members. In order to systematize and rationalize the verification of the built-up columns, this work aim to develop a computer program based on the standards NBR 14762, NBR 6355 and Eurocode 3, basically the considerations of the part EN 1993-1-1

Considerações sobre a armadura transversal de pilares de concreto armado

There are regulations that establish conditions and enable the design of armor columns. The NBR 6118 features statements relating to the transverse reinforcement as spacing, reinforcement diameters provision in structural elements and others. However, the norm in force does not provide an explicit methodology for the design of stirrups in different situations. We do not propose even a calculation model for this equipment and provides normative considerations for maximum or minimum values of spacings and armor in diameter. It is noteworthy that the classical references also do not provide a calculation routine sizing of transverse reinforcement and only makes the checks as the normative conditions for the given data. Based on this assumption and the problems that may occur in sizing error, both for spacing and for the proposal of the stirrup diameter, this study demonstrates that armor calculation method already established in the literature and then through an intuitive tool and available develops a spreadsheet based on this calculation routine. It takes as reference the one developed by Emil Moersch (1902) and the calculation model proposed by BUFFONI E SILVA (2006). Finally the paper presents a rational design of shear reinforcement and confronts these values with some numerical examples to show its truth