56 research outputs found

    Abdominal Aortic Aneurysm - From Basic Research to Clinical Practice

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    This book, intended for all physicians who are facing patients with abdominal aortic aneurysms, has been assembled by interested, invited authors and contains important topics from basic research to clinical practice. Experimental studies focus on biomechanical and biochemical factors. In clinical practice, the decision to treat, based on risk-benefit ratio, is very delicate in patients with concomitant malignant diseases. Periprocedural risk is determined by anatomy, while aneurysms causing neck pain are one of the most frequent challenges for both open and endovascular methods. Finally, careful planning is crucial. Postoperative complications are different from post-implantation syndrome, which is still an underestimated problem, toward detection and treatment of endoleaks and eventual conversion

    Thermal Stress Prediction in Divertor Cooling Finger Using the Local Heat Transfer Distribution

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    An approach that combines computational fluid dynamics (CFD) and structural mechanics simulation is used for evaluating stresses in a divertor cooling finger. Local distributions of heat transfer coefficient (HTC) between the helium and inner surface of the thimble are used as a boundary condition for the structural mechanics analysis. Stresses calculated with a realistic non-homogeneous HTC distribution are compared with the results where averaged HTC values in three representative zones of inner thimble surface are used. The obtained maximum stresses are considerably higher in the case of realistic non-homogeneous HTC boundary condition. The highest thermal stresses in the tile-thimble assembly are obtained on the thimble inner surface, in the region where the highest thermal gradients due to jet cooling can be observed. The results also show that tetrahedral based finite element model underestimate the computed stresses, especially when a coarse mesh is used.JRC.F.5-Safety of present nuclear reactor

    Computational Analysis of Blood Flow Characteristics in an Aortic System with Abdominal and Left Common Iliac Aneurysm Pre- and Post-Stent Grafting

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    © 2018 S. Djorovic et al. The aim of this study was to demonstrate how fluid dynamic parameters are affected by aortic geometry and flow condition in two cases. Case A included blood flow analysis in aortic system with abdominal aortic aneurysm and left common iliac aneurysm before stent graft placement, while in case B was included stent graft geometry, at the site of the aneurysms. An individual patient-specific geometry and a 3D finite element meshes were reconstructed, based on Computed tomography (CT) scan images. The analysis was performed using the possibilities of computational fluid dynamics. It uses numeric methods and algorithms for the simulation of blood flow by solving the Navier-Stokes equations on computational meshes. The computational simulations of cardiac cycles were performed for average blood properties and blood flow rate. The velocity field, pressure and shear stress, as main fluid dynamics parameters, were visualized and compared for cases A and B
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