Efecto de la congelación en rodillas animales. Estudio biomecánico experimental

Se estudia el comportamiento mecánico de rodillas animales que han sido congeladas en 1 o varias ocasiones mediante la aplicación de cargas axiales hasta la fractura o test destructivos. Se analizan el tipo y localización de fracturas aparecidas mediante un estudio radiográfico.We study the mechanical behavior in animal knees who are fresh frozen in one or various times. Axial loading are applied until the final fracture ( destructive test). Also it evaluates the tipe and localization of the fractures with radiological study

Dynamics of flexible fibers in viscous flows and fluids

International audienceThe dynamics and deformations of immersed flexible fibers are at the heart of important industrial and biological processes, induce peculiar mechanical and transport properties in the fluids that contain them, and are the basis for novel methods of flow control. Here we focus on the low Reynolds number regime where advances in studying these fiber-fluid systems have been especially rapid. On the experimental side this is due to new methods of fiber synthesis, microfluidic flow control, and of microscope based tracking measurement techniques. Likewise, there have been continuous improvements in the specialized mathematical modeling and numerical methods needed to capture the interactions of slender flexible fibers with flows, boundaries, and each other

The elements of a computational infrastructure for social simulation

Applications of simulation modelling in social science domains are varied and increasingly widespread. The effective deployment of simulation models depends on access to diverse datasets, the use of analysis capabilities, the ability to visualize model outcomes and to capture, share and re-use simulations as evidence in research and policy-making. We describe three applications of e-social science that promote social simulation modelling, data management and visualization. An example is outlined in which the three components are brought together in a transport planning context. We discuss opportunities and benefits for the combination of these and other components into an e-infrastructure for social simulation and review recent progress towards the establishment of such an infrastructure

Análise de fenômenos de transporte do escoamento de sangue na microcirculação

Monografia (graduação)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Mecânica, 2015.A camada livre de células sanguíneas escoando adjacente à parede de micro-vasos na micro-circulação é de vital importância no transporte de glóbulos vermelhos saturados de oxigênio para tecidos não saturados. O presente projeto propõe-se a examinar esse escoamento considerando o fluido adjacente à parede como plasma sanguíneo e no núcleo do micro-vaso (plasma) um líquido modelado tanto usando modelos Newtonianos de viscosidade conhecida até não-Newtoniano de viscosidades aparente e efetivas. A viscosidade intrínseca ou efetiva pode ser calculada teoricamente como uma função do diâmetro adimensional do vaso em concordância com observações experimentais. O modelo teórico sugere que em suspensões como o sangue, a viscosidade aparente pode ser reduzida pela distribuição não-uniforme de células. Então, a formação da camada de plasma é explicada em termos do balanço de dois mecanismos de transporte: uma convecção devido a interação parede do vaso-célula e o efeito de difusão hidrodinâmica das partículas. De acordo com o modelo proposto, as células podem ser transportadas respectivamente para dentro e para fora do centro da região do microvaso. Uma emulsão em alta razão de viscosidade é usada para calcular a difusividade e a velocidade de migração de partículas. Soluções assintóticas serão usadas para calcular a espessura da camada de plasma adjacente e a distribuição de fração volumétrica como função do tempo, da distância entre a parede do micro-vaso, da fração volumétrica dos glóbulos vermelhos (hematócrito típico), do número de Péclet, do número de capilaridade e da razão de viscosidade das fases dispersacontínua. Os resultados indicam que existe um decréscimo da espessura da camada de plasma adjacente com os números de Péclet e de Capilaridade. Em adição, descreve-se um camada limite associada a gradientes de concentração de partículas que se formam nas vizinhanças da parede do micro-vaso. Uma possível aplicação do trabalho proposto seria usar os resultados do mesmo para diagnosticar doenças com base em mudanças na viscosidade intrínseca fora dos padrões fisiológicos devido possíveis anomalias no sangue como anemia falciforme e câncer de medula. Também foi feito um estudo sobre a relação entre o formato da célula e a sua energia de flexão, com a motivação de verificar que formatos bicôncavos minimizam a energia de flexão para geometrias de mesmos volumes, áreas e propriedades mecânicas.There is a cell-depleted layer adjacent to microvessel walls and it is of vital importance in the transport of oxygen-saturated red cells to the unsaturated tissues. Firstly, we examine the core flow solution with the inner fluid being an non-Newtonian fluid facing a small annular gap of Newtonian plasma. An intrinsic viscosity of the blood is predicted theoretically as a function of the dimensionless vessel diameter, in agreement with previous experimental studies. The theoretical model suggests that in suspension flows like blood the apparent viscosity may be much reduced by the nonuniform distribution of cells. Secondly, the mechanism which leads to the depleted layer formation is explained in terms of a balance between two transport mechanisms: the wall drift velocity and the particle hydrodynamic diffusion. According to our model the cells can be transported respectively inwards and outwards of the core region of the microvessel. A high viscosity ratio emulsion is used to calculate the hydrodynamic diffusivity and the wall drift velocity. A similarity solution is used to calculate the thickness of the cell-depleted layer and the cell volume fraction distribution as a function of time, the distance from the microvessel wall, the volume fraction of red cells (typical hematocrit), Peclet number, capillarity number and viscosity ratio of the disperse-continuous phases. The results indicate a decreasing of the cell-depleted layer thickness with Peclet and Capillarity numbers. We also describe a concentration boundary layer in order to explain the observed phenomenon. A possible application of this work could be in illness diagnosis by evaluating of changes in the intrinsic viscosity due to blood abnormalities

Peering over the shoulders of giants?

‘Open’ is a highly-visible cultural trend of the early twenty-first century. A brief scan of anewspaper or quick Internet search reveals it as a prefix to learning, source, standard, data,knowledge, democracy, access, repository, innovation, government, science and probablymore. The expectations of the broadband generation – young people born around the turn ofthe century – for openness and instant, on‑demand access to information affect research asmuch as any other social activity. As the world’s population of digital residents – those whosee the Web as the place where they express opinions, form relationships, develop an identityand belong to a community – grows, the expectation that the Web will be the place whereinformation is created and communicated will grow alongside them

A Semantic Grid Oriented to E-Tourism

With increasing complexity of tourism business models and tasks, there is a clear need of the next generation e-Tourism infrastructure to support flexible automation, integration, computation, storage, and collaboration. Currently several enabling technologies such as semantic Web, Web service, agent and grid computing have been applied in the different e-Tourism applications, however there is no a unified framework to be able to integrate all of them. So this paper presents a promising e-Tourism framework based on emerging semantic grid, in which a number of key design issues are discussed including architecture, ontologies structure, semantic reconciliation, service and resource discovery, role based authorization and intelligent agent. The paper finally provides the implementation of the framework.Comment: 12 PAGES, 7 Figure

Collaboration in the Semantic Grid: a Basis for e-Learning

The CoAKTinG project aims to advance the state of the art in collaborative mediated spaces for the Semantic Grid. This paper presents an overview of the hypertext and knowledge based tools which have been deployed to augment existing collaborative environments, and the ontology which is used to exchange structure, promote enhanced process tracking, and aid navigation of resources before, after, and while a collaboration occurs. While the primary focus of the project has been supporting e-Science, this paper also explores the similarities and application of CoAKTinG technologies as part of a human-centred design approach to e-Learning