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Biblioteca Digital do IPB (53.442 recursos)

A Biblioteca Digital do IPB, tem por objectivo divulgar e permitir o livre acesso à produção científica produzida pela comunidade académica, promovendo a integração, partilha e a visibilidade da informação científica e garantindo a preservação da memória intelectual do Instituto Politécnico de Bragança.

DTM - Resumos em Proceedings Não Indexados ao ISI

Mostrando recursos 1 - 20 de 24

  1. Estudo da marcha de crianças em idade escolar que transportam mochilas às costas usando cinemática

    Rocha, Daniela; Rocha, João; Barbosa, Tiago M.; Queijo, Luís; San Jun, Manuel
    Este estudo teve como objectivo analisar a cinemática do ciclo da marcha de crianças em idade escolar, transportando mochilas às costas. Foram estudadas 4 crianças (3 do sexo masculino e 1 do sexo feminino) do 3º ano do primeiro ciclo do ensino básico (8 anos idade). Cada criança caminhou num tapete rolante a velocidades incrementais (1.11 m.s-1, 1.38 m.s -1e 1.67 m.s -1) e com diferentes cargas relativas à massa corporal (0 %, 10 % e 20 %) numa mochila escolar. Todos os procedimentos foram filmados no plano sagital e frontal e tratados com software específico para análise cinemática do...

  2. Analysis of the kinematics of gait of young adult female carryng a computer bag with single handle

    Rocha, João; Queijo, Luís
    The aim of this study is to assess postural changes in young female adults carrying a personal computer and some auxiliary material in a shoulder bag. Images have been recorded in the frontal and sagittal planes. After recording, the anatomical landmarks were manually digitized with appropriate software. Analyzing the data and comparing the two situations - with and without carrying a load can be registered significant differences in posture and normal gait.

  3. Manufacturing of lower-limb custom fit prostethics sockets using reverse engineering

    Curralo, Ana; Queijo, Luís; Rocha, João
    The objective of this project is the onstruction of an orthopaedic prosthesis for a person who has been lower limb amputated, above the knee, taking attention to the specifications of the amputation stump. Through this method the actual process of prosthesis design in rehabilitation technology is improved by applying reverse engineering and additive manufacturing technologies. The outcome of this work is a personalized prosthesis building procedure that should allow a stump-socket best fit and avoid the numerous iterations done until a proper fit is obtained with traditional methods.

  4. Desafios e tendências na avaliação do recurso eólico

    Ribeiro, Luís Frölén; Marques, Filipe
    Com o desenvolvimento de aerogeradores cada vez maiores aumenta a necessidade em caracterizar os campos médio e turbulento do escoamento cada vez mais afastados do solo (mais de 100 m). Tal começa a exigir uma alteração da metodologia de caracterização do recurso eólico até então aplicada, nomeadamente através do recurso a anemómetros (de copos ou sónicos) instalados em torres, por técnicas remotas de avaliação do recurso. Comparam-se as vantagens e inconvenientes da adopção dos anemómetros de copos e sónicos contra técnicas remotas como os SODARs e LIDARs. Estes últimos começam a ser identificados pela industria eólica como uma nova e possível tecnologia no apoio sistemático à caracterização do recurso...

  5. PDMS anatomical realistic models for hemodynamic studies using rapid prototyping technology

    Queijo, Luís; Lima, R.
    The main purpose of this work is to investigate a simple way of making polydimensiloxane (PDMS) anatomically artery models such as a carotid arteries with and without aneurysm. By using a human carotid computerized tomography (TC) it was possible to develop 3D anatomical models through the application of a rapid prototyping (RP) technique, known as tridimensional printing (TDP). By combining the TDP with a PDMS casting technique we were able to obtain at the end an anatomically transparent model of a human carotid artery made by a silicon elastomer, i.e. PDMS. We believe that this combination is a promising technique...

  6. Rapid prototyping of 3D anatomical models to hemodynamic studies

    Freitas, Vania; Queijo, Luís; Lima, R.
    The purpose of this work is mainly to manufacture several anatomical models in a polymeric material – polydimensiloxane (PDMS) to study the blood flow through a carotid artery bifurcation. Over the last few decades, research has been shown that the geometry of the carotid artery is closely related to the development of serious cardiovascular diseases. Hence, there is a considerable interest in the development of in vitro experimental techniques able to obtain accurate measurements of the blood flow behavior through a realistic carotid artery. In this study we decide to apply rapid prototyping (RP) technologies combined with a PDMS casting...

  7. Strain fields adjacent to bone-implant interfaces: strain field analysis using digital image correlation techniques

    Ribeiro, J.E.; Monteiro, J.; Lopes, H.; Vaz, M.A.P.; Guedes, R.M.
    When using conventional surface strain measurement techniques (e.g. strain gauges, dial gauges), the measurement of deformations within cancellous bone is frequently hampered by the material’s highly porous structure and poor mechanical properties. Although detailed strain maps derived from actual experimental data have the potential to resolve many questions concerning the mechanics of cancellous bone, the traditional method of producing maps through measurements with optical techniques has been applied infrequently in its study of this material.

  8. Measuring of non-uniform residual stresses in depth with optical techniques

    Ribeiro, J.E.; Monteiro, J.; Vaz, M.A.P.; Lopes, H.
    The goal of this work is the development of optical experimental techniques to measure non-uniform residual stresses in depth, as alternative to the hole-drilling method with strain gages. The proposed hybrid techniques are based on Moiré Interferometry and in-plane Electronic Speckle Pattern Interferometry (ESPI) and used the integral method for stress assement. In this work a shot peening specimen was used to compare the results obtained with different techniques: X ray diffraction, hole drilling with strain gages, finite elements method simulation and the referred optical techniques.

  9. Estudo preliminar da cinemática da locomoção de jovens adultos transportando mochilas com computador pessoal em saco com uma alça ao ombro

    Gonçalves, Nuno; Rocha, João; Queijo, Luís; Barbosa, Tiago M.; San Juan, Manuel
    Este estudo teve como objectivo analisar a cinemática da marcha de jovens adultos, transportando um saco com computador e outros materiais de apoio escolar ao ombro com uma única alça. Verifica-se que um grande número pessoas, por motivos profissionais ou mero lazer, estudantes, empresários, comerciais, etc., transportam cargas significativas. O facto de este tipo de populações tender a transpotar de forma frequente o computador pessoal e outro material informático e/ou didáctico, com pesos relativos não desprezíveis, nas deslocações entre casa e o local de trabalho/estabelecimento de ensino, assim como, no próprio local de trabalho, leva a que a identificação dos factores predisponentes para alterações posturais e consequentes ocorrências de...

  10. Flow visualization of trace particles and red blood cells in a microchannel with a diverging and converging bifurcation

    Leble, Vladimir; Fernandes, Carla S.; Dias, Ricardo P.; Lima, R.; Ishikawa, Takuji; Imai, Yohsuke; Yamaguchi, Takami
    This paper aims to investigate the effect of both diverging and converging bifurcations on the flow behaviour of pure water (PW) and red blood cells (RBCs). A confocal micro-PTV system is used to visualize and measure the flow characteristics of the working fluids. The results show no formation of a cell-free layer (CFL) around the apex of the bifurcation. In contrast, there is a clear formation of a triangular CFL just downstream of the confluence apex. As a result, this triangular CFL seems to play an important role on the in vitro blood flow characteristics at this region.

  11. Planeamento cirúrgico usando técnicas de prototipagem rápida: um estudo prévio

    Queijo, Luís; Rocha, João; Pereira, Paulo
    O uso da prototipagem rápida começou a revelar-se como uma ferramenta de grande valor no suporte à actividade médica. Partindo de imagens bidimensionais provenientes da tomografia computorizada (CT) ou de ressonâncias magnéticas (MRI), é possível obter modelos tridimensionais digitais que podem, posteriormente,ser transformados em modelos físicos (prototipagem rápida). Os modelos produzidos por tecnologias de prototipagem rápida são úteis tanto em ambientes educacional como médico-cirúrgico. Estes podem simplificar a visualização tridimensional de determinadas patologias e o planeamento de procedimentos cirúrgicos complexos, bem como permitir o fabrico de próteses e equipamentos e a visualização de estruturas anatómicas em ambiente educacional ser transformados...

  12. Measuring the cell-free layer in circular microchannels

    Fidalgo, Cátia; Lima, R.; Oliveira, M.; Ishikawa, Takuji; Imai, Yohsuke; Yamaguchi, Takami
    One of the most interesting hemodynamic phenomenon observed both in vivo and in vitro studies is known as Fahraeus-Lindqvist effect, in which the apparent blood viscosity decreases as the tube diameter is reduced, for narrow tubes (< 300 μm). The physical reason behind this phenomenon is the creation of a marginal cell-free layer at regions adjacent to the tube wall. Although intensively studied, the complex formation of the cell-free layer has not yet been convincingly described mainly due to multi-physical and hemorheological factors that affect this phenomenon. The main purpose of this experimental work is to study the effect of...

  13. Blood-on-chips: flow through complex geometries

    Lima, R.; Oliveira, M.; Ishikawa, Takuji; Matsuki, Noriaki; Imai, Yohsuke; Yamaguchi, Takami
    Blood is a complex body fluid, composed of cells and plasma, which holds a massive amount of information about several physiological and pathologic events happening throughout the body. Hence, blood sampling and analysis are used extensively in traditional clinical laboratories for the diagnosis of several diseases. Since the inception of microfluidics, there has been a growing interest, by both microfluidic and biomedical communities, to develop blood-on-chip devices as an alternative tool for the diagnosis of major diseases, such as cancer and cardiovascular diseases. Therefore, it is essential to understand the blood flow behaviour involved in this kind of microfluidic channels...

  14. Micro-flow visualization of in vitro blood through a microchannel with a bifurcation and confluence

    Cidre, Diana; Lima, R.; Fernandes, Carla S.; Dias, Ricardo P.; Ishikawa, Takuji; Imai, Yohsuke; Yamaguchi, Takami
    Micro-visualization techniques have been used to investigate the in vitro blood flow through straight glass capillaries. Although the glass microchannels present certain similarities to in vivo microcirculation, it is also clear that these kind of in vitro experiments differ from microvessels in several respects, such as: elasticity of microvessels, effect of the endothelial surface layer and microvascular networks composed with short irregular vessel segments which are linked by numerous bifurcations and convergences. Thus it was not surprising that several studies on blood flow in glass microtubes and in microvessels have yielded conflicting results with respect to blood viscosity and flow...

  15. Behaviour of piozoelectric devices embedded in bone cement

    Frias, C.; Marques, M.A.; Ribeiro, J.E.; Vaz, M.A.P.; Simões, J.; Marques, A.T.
    Bone cements based on polymethacrylate (PMMA) are essential products in joint arthroplasty. PMMA bone cement function is to locate the implants components in the body skeleton, load transition through the joint into the bone and muscle surrounding for a very for a very long period of time. Its mechanical properties are well established in the literature. Since bone cement fills the void between the prosthesis (polymer or metallic) and bone, it is subjected to high stress and has to operate in a relatively aggressive environment, like human body. Therefore, based on surrounding environment PMMA bone cements application, this material has...

  16. In vitro blood flow in circular PDMS microchannels: effect of the flow rate and hematocrit

    Garcia, Valdemar; Dias, Ricardo P.; Correia, Teresa Montenegro; Lima, R.; Pinheiro, Elisa; Pinho, Diana; Rodrigues, Pedro
    Alocar também a:Teresa Montenegro Correia- ESA

  17. Técnicas de medição de tensões residuais

    Ribeiro, J.E.; Vaz, M.A.P.; Piloto, P.A.G.; Monteiro, J.
    Ao longo das últimas décadas praticamente todas as técnicas de análise experimental de tensões foram utilizadas na caracterização de tensões residuais. Dadas as dificuldades encontradas algumas técnicas foram especialmente desenvolvidas para esta aplicação. Neste texto descreve-se o trabalho já realizado no Laboratório de Óptica e Mecânica Experimental (LOME) para caracterizar campos de tensões residuais utilizando algumas das técnicas disponíveis.

  18. Use of optical techniques in the assment of the displacement field near the crack tip

    Ribeiro, J.E.; Vaz, M.A.P.; Lopes, H.; Melo, F.J.M.Q. de; Monteiro, Jaime
    A crack tip represents a highly singular stress field existing in a structural component. The evaluation of the associate strain gradient is difficult using experimental discrete methods. An efficient alternative relies on optical methods which are non contact and give continuous information about displacements fields and its derivatives for strain evaluation. This paper describes some experimental methods to fully characterize the displacement field near a crack tip existing in flat plates. Three optical field techniques based on image analysis were used in the present work; respectively ESPI (Electronic speckle pattern interferometry), MI (Moiré Interferometry), and DIC (digital image correlation). These methods...

  19. Residual stress assessment using optical techniques

    Ribeiro, J.E.; Vaz, M.A.P.; Piloto, P.A.G.; Monteiro, J.; Lopes, H.
    The goal of this work is the development of different experimental techniques to measure residual stresses, as alternative to the hole-drilling method with strain gages. The proposed experimental techniques are based on the use of Moiré Interferometry and in-plane Electronic Speckle Pattern Interferometry (ESPI). Both are field techniques allowing the assessment of in-plane displacements without contact and high resolution. Grating replication techniques were developed to record high quality diffraction gratings onto the specimen’s surfaces. An optical set-up of laser interferometry was, developed to generate the master grating (virtual). An in-plane ESPI set-up was also designed and implemented to measure displacements in one direction. The stress relaxation was promoted...

  20. Simulação numérica do comportamento de uma mandíbula humana durante actividade mastigatória

    Piloto, P.A.G.; Ribeiro, J.E.; Campos, J.C. Reis; Correia, A.; Vaz, M.A.P.
    A mandíbula humana é um dos ossos, cujo estudo é mais difícil de analisar, pois combina, com uma elevada sofisticação, uma complexa geometria com elementos anatómicos que incluem osso cortical e esponjoso, tecido dentário, ligamentos, nervos e vasos sanguíneos. Neste trabalho pretende-se estudar o seu comportamento, simulando a actividade mastigatória, com elementos finitos tetraédricos, recorrendo aos conhecimentos da anatomia humana, e impondo condições de fronteira que se aproximam do seu comportamento durante este processo [Al-Sukhun (2007)].

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