Browsing by Author "Snyman, M F"

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    Numerical modelling of an offshore pipeline laid from a barge
    (1989) Snyman, M F; Mercer, Colin
    This thesis addresses some of the issues involved in using numerical methods to simulate the laying of an offshore pipeline, the objective being to contribute to the expertise of the South African offshore technology. Of particular interest is the prediction of the stresses in the pipe during such an event. The thesis concentrates on the use and suitability of the finite element method to simulate the important aspects of the pipelaying problem. ABAQUS, a nonlinear general purpose finite element code, was chosen as numerical tool, and nonlinear effects such as geometry and drag, as well as contact and lift-off at the boundaries, are included in the models. The analysis is performed in two parts: in the static analysis the displaced equilibrium position of the pipeline under self weight, buoyancy and barge tension is sought, whilst the response due to wave action and barge motion is of interest in the dynamic analysis. Numerical experiments show the suitability of ABAQUS to model the behaviour of slender structures under both static loads and dynamic excitations.
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    Numerical modelling of dilatant rock joints
    (1991) Snyman, M F; Jackson, Graham Ellis
    Aluminium forms a highly neurotoxic complex with maltol (3-hydroxy-2-methyl-4H-pyran-one). The stability of this complex has been determined using glass-electrode potentiometry. Owing to the effect on nuclear relaxation behaviour, paramagnetic contrast agents have immense diagnostic potential and have recently received a great deal of attention in the literature. The gadoliniummaltol complex was studied with the view to developing a potential tissue-specific magnetic resonance imaging contrast agent. Because of the interest in medical applications of radioactive isotopes of group 1118 elements, the indium-maltol complex was studied in order to assess its radiopharmaceutical usefulness. The major analytical techniques used in this study are potentiometry and high resolution nuclear magnetic resonance spectroscopy.