470 research outputs found
Monitoring degradation of single and multilayer organic coatings. I. Absorption and transport of water: Theoretical analysis and methods
No full textThis paper presents a mathematical model describing the change in the capacitance of both single and multilayer organic coatings exposed to a wet environment. The indication is that the capacitance technique can successfully be employed to monitor, in situ, the absorption of water through single-layer organic coatings for values of equilibrium water uptake to a maximum of 5% by volume. In addition, this model indicates a relationship for d(In C)/d√t, where C is the coating capacitance and t is the time of exposure to the environment, that can be used to rank different single-layer coatings. Conversely, no quantitative correlation between mass uptake and coating capacitance was found for a multilayer coating system, even for low values of water uptake. Although, at face value, these findings suggest that this technique may be inappropriate for in situ monitoring of water absorption in such complex systems, a comparison between gravimetric and capacitance data indicates that useful qualitative information may still be generated by the use of the latter technique
Fast 3D reconstruction of the rib cage from biplanar radiographs
No full textE. Jolivet, B. Sandoz, S. Laporte, D. Mitton, W. Skall
The wet corrosion of molybdenum thin film part ll: Behavior at 85 °C
No full textIn the past few years there has been increased interest in molybdenum thin films, which are commonly prepared by magnetron sputtering. There is a variety of novel applications of molybdenum such as, for example, components for soft X-ray optics based on Mo/Si multi-layers, the back contact in thin film solar cells, NO gas detection, and microelectronics. Molybdenum is, also, widely used as an alloying addition in stainless steels to facilitate the formation of the passive film and to improve resistance to pitting attack. Its corrosion behaviour is complex and many aspects still need to be clarified. During this study, the corrosion behaviour of the PVD-Mo thin film immersed in aerated sulfate and chloride solutions at 85°C was investigated with both polarization and electrochemical impedance spectroscopy (EIS) measurements. It is apparent that the Mo thin film exhibits increased susceptibility to corrosion in more alkaline environments
Degradation behaviour of 6013-T6, 2024-T3 alloys and pure aluminium in different aqueous media
No full textThe electrochemical and corrosion behaviour of 6013-T6, 2024-T3 aluminium alloys and pure aluminium in 0.6 M NaCl and 0.3 M Na2SO4 aqueous solutions was investigated using d.c. and a.c. electrochemical techniques. Results show that the 6013-T6 alloy exhibits superior corrosion resistance compared with that exhibited by the 2024-T3 alloy in both environments. These findings were interpreted on the basis of a barrier oxide film model
The Relationship Between Substrate Mass Loss Assessed by Vibrating Sample Magnetometer and Corrosion Rate Measured by Electrochemical Impedance Spectroscopy for a Polymer-Coated Metal
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