Sökning: "vessel wall"
Visar resultat 21 - 25 av 196 avhandlingar innehållade orden vessel wall.
21. Measurements and Prediction of Friction Drag of Rough Surfaces
Sammanfattning : Owing to the increased sea transportation of goods, the environmental impacts of this activity are becoming more and more important, since a ship experiences resistance that directly affects its performance and fuel consumption. The growth of marine organisms (fouling) on ship hulls increases the roughness of the hull surface, which in turn causes a rise in ship resistance with a consequent increase in fuel consumption and greenhouse emissions of up to 40%. LÄS MER
22. Anaesthetics and the blood vessel wall. Actions of propofol and sevoflurane on sympathetic and endothelial control of smooth muscle function
Sammanfattning : The anaesthetics we use today dose-dependently decrease the mean arterial pressure partly due to direct or indirect effects on the blood vessels. In the present thesis human omental arteries and veins and rat femoral arteries were investigated in vitro concerning the effects of the intravenous anaesthetic propofol and the volatile anaesthetic sevoflurane on the function of the perivascular sympathetic nerves and the endothelial cells. LÄS MER
23. Modelling and Simulation of Reactor Pressure Vessel Failure during Severe Accidents
Sammanfattning : This thesis aims at the development of new coupling approaches and new models for the thermo-fluid-structure coupling problem of reactor pressure vessel (RPV) failure during severe accidents and related physical phenomena. The thesis work consists of five parts: (i) development of a three-stage creep model for RPV steel 16MND5, (ii) development of a thermo-fluid-structure coupling approach for RPV failure analysis, (iii) performance comparison of the new approach that uses volume loads mapping (VLM) for data transfer with the previous approach that uses surface loads mapping (SLM), (iv) development of a lumped-parameter code for quick estimate of transient melt pool heat transfer, and (v) development of a hybrid coupling approach for efficient analysis of RPV failure. LÄS MER
24. Abdominal Aortic Wall Mechanics - Stress, Strain and Stiffness in A Medical Perspective : An Experimental Study in Man
Sammanfattning : Background: The stiffness of the abdominal aorta is considered a significant factor affecting the morbidity and mortality of cardiovascular disease. Estimating vascular stiffness is an integral part in cardiovascular risk assessment. LÄS MER
25. CFD Study of Molten Pool Convection in a Reactor Vessel during a Severe Accident
Sammanfattning : During severe accidents in nuclear reactors, the core and internal structures can melt down and relocate into the reactor pressure vessel (RPV) lower head (LH) forming there a stratified molten corium pool. The pool generally consists of superheated oxidic and metallic liquid layers imposing thermo-mechanical loads on the RPV wall. LÄS MER
