Influência da aplicação de cargas estáticas axias e não axais em próteses parciais fixas de três elementos, análise pela extensometria

Um bloco de poliuretano recebeu três implantes de hexagono externo, no posicionamento compensado. Para cada implante foi conectado o pilar protético microunit. Foram realizados cinco enceramentos com três coifas plásticas cada um, que foram fundidos em monobloco numa liga de cobalto-cromo. Foram colados quatro extensomêtros tangenciando cada implante, sendo dois extensomêtros para o implante central. Após o acabamento, as estruturas foram fixadas nos respectivos locais com o parafuso de retenção com torque de 10 Ncm, obtidos com um torquímetro. Para aplicação de carga sobre os corpos-de-prova foram selecionados cinco pontos de aplicação de carga. O dispositivo de aplicação de carga–DAC foi utilizado 30 kg de cargas verticais estáticas, empregando uma ponta esférica de 2 mm de diamêtro, durante 10 segundos em cada um dos pontos estabelecidos, sendo, neste instante registradas as micro deformações de cada extensômetro. Foi utilizado o teste de análise de variância T Student e o nível de significância foi o valor convencional de 5%. Para cada implante foi analisada a microdeformação ocorrida. Os resultados obtidos mostraram que houve uma diferença estatisticamente significativa entre os pontos não-axiais D e E (t = 5,21 df = 4, p = 0,006 < 0,05) e não foi estatisticamente significativa para os dados axial entre os pontos B e C (t = 6, 57, df = 4, p = 0,003 < 0,05 / 3). Conclui-se que,a aplicação de carga ao redor de três implantes de hexágono externo no posicionamento compensado,mostra que os pontos não-axiais sofrem maior micro deformação do que os pontos axiais

Projeto de um dispositivo para prensar bobinas polares de pólos salientes para hidrogeradores

The increasing demand for productivity and quality in companies has converged to a common point: reducing costs. In this context the present work aims at the development of a mechanical press which is designed for pressing polar hydrogenerators coils with salient pole in field facilitating the assembly of the poles in the plant, as well as reforms especially in hydrogenerators, reducing significantly the transport costs. With security in mind as well as reduced costs, a study was made of the materials to be used as it was applied a methodology for calculating the correct choice of safety factor to be used in the device. Through mechanical calculations were dimensioned critical items of the device as the diameter of the rods as well as the minimum thickness of the base of the device must have so that it does not break threaded shear in the region by applying the total load of traction on the risers implementation of the pressing. All compression loading device will be through the application of torque on the nuts of bolts in this way was defined by calculations the required torque for each nut so that you can reach the pressure specified in the design specifies. The modeling of the device was made using the INVENTOR™ program in conjunction with the program ANSYS ™. These programs have created designs in three dimensions, assembly and simulation of stress analysis in components of the device

Efeito protetor após sessões de exercício excêntrico: comparação entre membros superiores e inferiores

The objective of the present study was to compare in which part (lower limb or upper limb) the repeated bout effect has the greatest magnitude. Twelve males individuals with no recent (6 months) experience with resisted training participated in this study. The subjects were randomly divided into two groups (legs and arms) and came to the laboratory 5 times. 1st) adaptation to the dynamometer. 2nd) to perform one bout of eccentric exercise (EE) and provide markers such as isometric peak torque (IPT), delayed onset muscle soreness (DOMS) (both collected before and after the bout) and concentration of the creatine kinase (CK) enzyme in the blood (only before the bout). 3rd) 48 after the first bout the same markers were collected again. After 14 days, the methodologies used in the 2nd and 3rd visits to the laboratory were repeated respectively to determine the repeated bout effect. A significant decrease of IPT and a significant increase of CK and DOMS were found immediately after and 48 hours after the first bout of EE for the arms group. The legs group showed a significant increase in CK (48 hours after the EE) and DOMS (immediately after the EE) resulting from the first bout. In the arms group, the second bout did not cause significant increase in CK or DOMS on any of the situations, however, it provoked a decrease in force production immediately after the EE. The legs group showed a significant increase of DOMS immediately after the second bout of EE, which caused no significant increase in CK. The only marker in which the repeated bout effect happened for both groups was CK. No significant difference was found between the protections for both groups. Taking into account the results, it’s been discussed whether there is a relation between the susceptibility to muscle damage and the repeated bout effect, and also...(Complete abstract click electronic access below)

Análise cinemática e dinâmica para conversão de um VW saveiro em veículo elétrico

This work aims to kinematic and dynamic analysis of a VW Saveiro in order to estimate the power requested to the engine with the imposed movement conditions. Thus, the study will be the basis to the specification of the electric engine, on the conversion of the internal combustion vehicle into electric one. First of all, a literature review was done in order to understand the state of the art for this issue and come up with the technical features of the vehicle in question. The next step is the identification and calculation of all forces acting on the prototype in motion, from 0 to 120 km/h, in intervals of 10 km/h, under the defined conditions of path and time. Then, were determined the values of the torque and rotation of the components from the transmission system, as well as the engine power, for each speed range. The results show the most influential forces on the resistence of the movement in each speed range, and the behavior of the torque curve is verified. Finally, it was also analyzed the implementation of pinwheels on the frontal area of the vehicle, in order to convert wind energy into electrical energy to supply the lighting subsystem of the vehicle and the proposal was validated. Limiting the maximum speed of the vehicle to 90 km/h, it was finally concluded that the power of the electric engine should be 40 HP

Efeitos do treinamento isocinético e isométrico sobre a taxa de desenvolvimento de força máxima

The objective of the present study was to compare the effects of a high speed isokinetic training (180°.s-1) and an isometric training (75°) on the maximum rate of force development (RFDmax) measured in the isokinetic and isometric modes. Twenty seven male non active subjects participated of this study (Mean + SD = body mass 78.6 + 14.1 kg; stature 175.1 + 8.9 cm; age 22.6 + 3.8 years). They were randomly divided into three groups: Control (GC); Isokinetic training (GISOC) and; Isometric training (GISOM). The subjects were submitted in different days to the following pre training protocols: 1) Familiarization to the isokinetic dynamometer tests; 2) Five maximum concentric isokinetic contractions of the knee extensors (180°.s-1) to access the maximum concentric torque (TMC) and the concentric RFDmax; 3) Two maximum isometric contractions of the knee extensors (75°) to access the maximum isometric torque (TMI) and the isometric RFDmax. The same tests were repeated after the training period, but without the familiarization session. Eighteen training sessions were performed (3 times per week). The GISOC performed the entire training whit concentric isokinetic contractions whit the speed of 180°.s-1. The GISOM performed the entire training whit isometric contractions whit the angle between the thigh end the leg being 75° (0° = full knee extension). TMI, TMC, concentric RFDmax, isometric RFDmax values of the GC was not different between pre and post training. GISOM increased only the TMI and the GSIOC increased the TMC, concentric RFDmax and isometric RFDmax. Furthermore, the GISOC had a higher percentage increase of the isometric RFDmax than the isokinetic RFDmax. Based on these results, it is possible to conclude that the increase in maximum strength corresponded to the training specificity theory, unlike to the RFDmax. Thus the use of isometric contraction ...(Complete abstract click electronic access below)

Um Estudo de caso sobre a fabricação de engrenagens

Human evolution has always been linked to personal or group needs. This statement is based on observations of the day to day. With time, we can now choose from among many excellent techniques and materials that can be employed in the construction of this part of the machinery so important to the functionality of machines and equipment. When we look at a machine, we see that this is usually designed by combining a set of pre-determined in your project. Among the many pieces that we can highlight one of them is of fundamental importance, the gear. Gears are an example of the mechanical devices used by the older man, and are currently the most important components in the transmission technique. This is responsible for transmitting rotary motion from one shaft to another. Gears are one of the best among the various means available for the transmission of motion. Gears are the most important components of modern technique of transmission. The main purpose of a transmission gear is precisely transmit torque and speed. The requirements have increased significantly due to pollution and energy conservation. Nowadays, gear transmissions are required to transmit high strength through all his life together with the high demand on performance and sound properties. An optimal design for the gear you need a set of the most modern fabrication machines and cutting tools. In the following work is studied on the manufacture of gears, making the monitoring of a case study of the try out the installation of a gear grinding machine

Projeto, desenvolvimento e construção de um redutor/multiplicador de velocidades de baixo custo

This paper aims to present the design, development and construction of a reducer / multiplier speeds low cost, sturdy and easy operation. The beginning of the project was given to research on issues related to mechanisms and machine elements, and these theories of fundamental importance in the development of items of equipment which, together with the aid of AutoCAD software, enabled the construction of it. Parallel to the sizing of equipment, were also investigated and taken into account the costs of materials used in the project. Made to mount the reducer / multiplier speeds it was at the evidence through experiments involving the use of torque wrench, tachometer and weights, getting proven applicability in situations that are small or medium loads required

Treinamento de força unilateral: efeitos sobre a taxa de desenvolvimento de força do membro contralateral

The aim of this study was to analyze the effects of unilateral isokinetic strength training at high speed (180°.s-1) of the dominant leg on the rate of force development (RFD) of the contralateral limb. The study included 18 male individuals, apparently healthy, with an average of 23 years, and without regular practice of physical activities. The subjects were divided randomly into two groups: control group (GC) and isokinetic group (GISOC). Assessments were made of the values of peak isometric torque (PT isom) and RFD of both lower limbs in the pre-training. So, the GISOC underwent an isokinetic strength training with high speed (180°.s-1) for 6 weeks, with the dominant leg only and then reassessed. It was found that there was no significant improvement in value of PT isom (p> 0.05), and the RFD for the dominant limb had a significant improvement (p< 0.05) compared to the pre-training and that there was no transfer of values to the contralateral side (p> 0.05). It can be concluded that the isokinetic training at high speed was not enough for significant cross education

Análise da estabilidade do movimento rotacional de satélites artificiais com quatérnions e sob a influência de torques externos

The aim of this work is to analyze the stability of the rotational motion’s artificial satellite using the Routh Hurwitz Algorithm (CRH) and the quaternions to describe the satellite’s attitude. This algorithm allows the investigation of the stability of the motion using the coefficients of the characteristic equation associated with the equation of the rotational motion in the linear form. The equations of the rotational motion are given by the four cinematic equations for the quaternion and the three equations of Euler for the spin velocity’s components. In the Euler equations are included the components of the gravity gradient torque (TGG) and the solar radiation torque (TRS). The TGG is generated by the difference of the Earth gravity force direction and intensity actuating on each satellite mass element and it depends on the mass distribution and the form of the satellite. The TRS is created by changing of the linear momentum, which happens due to the interactions of solar photons with the satellite surface. The equilibrium points are gotten by the equation of rotational motion and the CRH is applied in the linear form of these equations. Simulations are developed for small and medium satellites, but the gotten equilibrium points are not stable by CRH. However, when some of the eigenvalues of the characteristic equation are analyzed, it is found some equilibrium points which can be pointed out as stables for an interval of the time, due to small magnitude of the real part of these eigenvalue

Extensometria: estudo das microdeformações ao redor de três implantes de hexágono interno, com posicionamento linear, sob a influência da fundição de coifas plásticas e usinadas

The objective of this in vitro study was quantify the micro strain development around the internal hexagon implants, varying the type of prosthetic coping. For This reason, three implants of internal hexagon were inserted into one polyurethane block in line placement. Microunit abutments were screwed onto the implants. Tangentially the implants were bonded the strain gauges, two to the center implant. Ten structures, each one containing three copings were cast in Co-Cr alloy, that were divided into groups in the first group, plastic copings were used, and in the second group machined copings were used. The superstructure’s occlusal screws were tightened onto Microunit abutments with 10 Ncm torque, the magnitude of micro strain was recorded. The mean values of each strain gauge of each plastic copings were 363,37 ± 237,66 and the machined copings were 338,12 ± 223,01. The data were analyzed statistically by t- Student test. No statistically significant difference was found between the prosthetic copings (p= 0,867). It was concluded that to internal hexagon implants in line placement, the type of copings presented similar magnitude of micro strain after prosthetic occlusal screw was tightened

Sobre a dinâmica de rotação de um planeta através de um sistema médio

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação da influência do formato da porca e da pré-carga em juntas aparafusadas em tração

Many structures and mechanical equipment requires a union member, and the screw is one of the most used, the cost is low, it is versatile and easy to find on the market. The resulting pre-load assembly torque associated with the cyclical external load has great influence, so it will be studied carefully. This study analyzed some of these factors, as the format of nuts, and the washer material when they are incompatible with the bolt material can cause a reduction in life of the joint fatigue

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

Avaliação in vitro das microdeformações em implantes curtos, com conexão protética cone morse e diferentes desenhos de roscas, convencionais e platôs

Pós-graduação em Odontologia Restauradora - ICT

Pesquisa de genomas virais em primatas não humanos do novo mundo por metagenômica

Pós-graduação em Medicina Veterinária - FMVZ