Metallic biomaterials have been used widely for biomedical application. One of them is titanium alloy that has proved having good biocompatibility to human body. In other hand, the materials should preferably posses a low Young’s modulus in order to inhibit the stress shielding effect which would probably cause excessive bone absorption because of decreased mechanical stimulation to that part of bone replaced with metallic medical devices. One such alloy has been developed, TNTZ, is a ß-type titanium alloy and having low Young's modulus (40–60 GPa) similar to that of bone (10–30 GPa), so it is suitable as prosthetic devices especially and other biomedical devices. However, metal is considered as foreign object that may cause negative effects. It is necessary, therefore, to do surface modified with biological materials to reduce those effect. One way is surface coating with collagen, where that is one of human body components and also in human bone. Surface coating with collagen has been done with time and temperature variations. The research method was dip coating method with 5, 15, and 25 minutes for time variations, and 40C and 270C (room temperature) for temperature variations. The result showed that the best result for surface coverage is 5 minute and 40C treatment. Surface coverage is 96% with thickness was 5.2 μm. Temperature variations did not have effect significantly for surface coverage and the thickness. We concluded that the best method to coat titanium, TNTZ surface with collagen with dip coating method is 5 minutes, 40C treatment to acquire the surface coverage orderly.
Department of Biomedical Science, Medicine Faculty, Universitas Andalas, Padang, Indonesia
Department of Mechanical Engineering, Engineering Faculty, Universitas Andalas, Padang, Indonesia
Department of Biology, Mathematic and Science Faculty, Universitas Andalas, Padang, Indonesia
Department of Surgery, Medicine Faculty, Andalas University, Padang, Indonesia
Load-out is one of critical part during construction of an offshore structure and one of the load-out methodology is load-out by using SPMT (Self Propelled Modular Transporter). SPMT can transport to the uneven ground condition by using hydraulic system. Three point suspension set-up and four point suspension set-up are two common levelling hydraulic system on SPMT. There is a significance difference during preparation of SPMT on each levelling system in term of time and cost. This study aims to analyse the structural integrity of offshore structure including barge response during load-out transportation. This study compare load-out transportation arrangement between each levelling system during cross over to the barge by using simulation. Transportation analysis to check offshore structural integrity during cross over to the barge is done by Staad Pro and PIAS software. Three point suspension set-up is more safely used for super heavy weight structure and four point suspension set-up is better for normal and intermediate heavy weight structure with considering cost, time and productivity to setting the suspension set-up and transportation arrangement.
Naval Architecture and Offshore Engineering, School of Mechanical Engineering, Universiti Teknologi Malaysia, Malaysia
Ocean and Aerospace Engineering Research Institute, Indonesia
The analysis of the uncoupled vertical motions of the Bonga FPSO is performed for unrestricted service. The study made use of Airy’s wave model and the strip theory, to determine the excitation forces and moments, hydrodynamic coefficients, and the RAOs. Spectral analysis was done on the basis of the above results with the Pierson-Moskowitz wave energy density spectrum using the 100-year return period storm data of the North Sea to predict the vessel responses in a realistic sea, as well as forecast the number of green water and slamming at the bow per hour. Furthermore, the (HaPMotA) computer programme written in MATLAB on the basis of the above theories was used for the analyses. As a result, the RAO diagrams, the response spectrum, force and moment diagrams, the responses for the modes of motion investigated, and the operability of the vessel in harsh environment were obtained. The result indicates that the freeboard needs to be increased to mitigate the effects of green water in the harsh environments.
Department of Marine Engineering, Rivers State University, Port Harcourt, Nigeria
