Corona-glow mixed conditions of an atmospheric-pressure barrier discharge in air and nitrogen gases were estimated quantitatively. To quantify the discharge conditions, electrostatic patterns remained on the barrier electrode surface. The patterns, called dust-figures, were produced by a color toner. The complexity of the electrostatic pattern was defined by (outline)2/area. Effective discharge power and discharge emission were estimated using Q-V Lissajous' method and an image intensifier, respectively. The difference between discharge conditions in air and nitrogen could be distinguished using the complexity and the area of the electrostatic pattern on the barrier electrode surface. The difference in discharge conditions with varied discharge gaps was also estimated quantitatively. Further, in the region of complexity from 0 to 20k, it seems that the corona-glow mixed conditions can be defined quantitatively. The quantification method for discharge conditions established in this work is extremely useful in improving the electrode composition, the material for the barrier layer, the frequency and shape of the driving voltage, etc. in an atmospheric-pressure barrier discharge system.
Ion implantation was used to improve the hydrophobicity of a fluorine-polymer (PTFE). The Ar-implanted PTFE is covered with uniform needle-like protuberances that have sharp peaks, separated by a few micrometers. A CF3 structure, which has a very low surface energy, was observed on an ion-implanted surface via X-ray photoelectron spectroscopy (XPS) analysis. The effects of a modification parameter, an accelerated voltage, and a beam current on the roughness, morphology, and structure of the treated surface were analyzed. The resulting optimally-modified surface is strongly hydrophobic. The contact angle with water increased from an initial 103 to 170 degrees. Spectral analysis of the roughness of the modified surface shows that the contact angle with water depends on the spacing and uniformity of the protuberances.
A Ni-P/Al hard disk substrate has been analyzed by Glow Discharge Optical Emission Spectroscopy (GDOES) and by cross-sectional transmission electron microscopy. With GDOES, all of the distributions of impurity species, as they related to disk fabrication processes, have been revealed successfully within the Ni-P layer, at the polished Ni-P surface, and at the Ni-P/Al interface with excellent sensitivity and depth resolution for the first time. Further, the structural details of the disk, such as the structure of Ni-P deposits, the Ni-P/Al interface, and the presence of alumina polishing particles on the surface, have been revealed clearly by cross-sectional transmission electron microscopy.
To obtain an environmentally-compatible corrosion inhibitor similar to tannic acid, three varieties of polyphenol polymers, poly (caffeic acid), poly (caffeic acid-co-sodium styrene sulfonate) and poly (caffeic acid-coacrylic acid), were synthesized. The effects of polyphenol polymers on the corrosion of mild steel in boiler systems under alkaline conditions have been investigated. These polymers are able to inhibit corrosion due to the Schikorr reaction. In particular, two copolymers inhibit the corrosion of mild steel in the same manner as tannic acid.