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In this study, deposition of MoS_2 thin films by D.C. magnetron sputtering was studied with regard to the micro-structural change of MoS_2 film and mechanical properties. The deposition parameters such as the working pressure, deposition time, bias voltage, etching time were varied to determine how these parameters affected the film morphology and mechanical properties of deposited films. The microstructure of the MoS_2 films is nanostructure and very strongly influenced by the sputtering process conditions. The grain size increased with the increase in the working pressure and decreased with the increase in the bias voltage.

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The formation mechanism of defects including pickle patch, streaky line and under-alloying that frequently observed on the surface of galvannealing sheet steel in continuous galvanizing line have been characterized by scanning electron microscopy, transmission electron microscopy, optical microscopy, electron probe microanalysis and roughness profiler. It is clear that both substrate composition and its surface microstructure immediately before dipping into molten Zn are essentially critical for the formation of optimum coating of the desired microstructure and properties. A appearance of various thin oxidation layers at coating/substrate interface during annealing process was found to be the main factor causing surface defect and appeared to be associated with different rate of Fe-Zn reaction. A microstructural model was proposed to explain the mechanism of defect formation on the surface of galvannealing sheet steel.

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The use of heavy metal-based corrosion inhibitors is increasingly being curtailed by recent environmental restrictions. In many parts of the world, high levels of inorganic phosphates are also restricted by law. In response to these environmental guidelines, this paper presents the results of a "green" chemicals study that was undertaken to investigate the ability of a new inhibitor to inhibit the corrosion, scale and microorganism problems found in open recirculating cooling systems. This study used a new all-organic multi-component inhibitor blend composed of citric acid/ phosphonates/ acrylate copolymer/ isothiazolone. The effects of the inhibitor on carbon steel dissolution in synthetic cooling water were studied through weight loss measurements and electrochemical, scale, and microorganism tests. The results obtained from this study show that the new inhibitor can decrease corrosion, scale build-up and microbial growth under the conditions tested. Potentiodynamic polarization curves indicate that the blended inhibitor acted as an anodic inhibitor, reducing metal dissolution. The nature of protective films formed on the carbon steel was studied by scanning electron microscopy (SEM) and auger electron spectroscopy (AES). The inhibition effects are due to the formation of protective films which might contain calcium phosphonates and iron oxide. The inhibitor used in this study appears to have an excellent crystal modification effect on calcium carbonate scale. The various microorganisms used in this study were inhibited effectively in the planktonic state.

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Numerical Analysis for travelling electromagnetic field, turbulent fluid flow and heat transfer during the electromagnetic direct chill (DC) casting of aluminium alloys were carried out. The influences of coil current, frequency and the travelling direction of electromagnetic field on electromagnetic force, flow velocity, effective viscosity and the shape of the solidification shell were examined. It was found that electromagnetic force, flow rate and effective viscosity become maximum with the frequency at which the penetration depth of electromagnetic field becomes about half of the ingot radius. The liquid sump depth does not change significantly when downwards travelling magnetic field is applied, while it become large when upwards travelling field is applied. The flow velocity and effective viscosity increase more strongly with coil current for downward traveling field than for upward travelling one.

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In order to produce low sulfur steel, an optimum ladle slag composition was investigated as a function of CaO/Al_2O_3 (mass%) ratio and (T.Fe+MnO) content of the ladle slag. The effects of CaF_2 addition and ladle slag recycling on the desulfurization rate were also studied. An optimum value of CaO/Al_2O_3 ratio for desulfurization was 1.6∼1.7 and desulfurization reaction was enhanced when T.Fe + MnO was less than 1 mass%. The desulfurization rate constant (K) increase by the increase in the CaO/Al_2O_3 (mass%/mass%) ratio until 1.7 and it decrease afterward. However, desulfurization rate constant (K) did not show decreasing trend over 1.7 (CaO/Al_2O_3 ratio) when recycled ladle slag or CaF_2 was added.

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Reduction behaviour of iron oxide(Fe_2O_3) in carbon-iron oxide pellets was investigated in the temperature range of 1100-1500℃. The unreacted oxygen and carbon content in the pellet as well as the reduction degree of the iron oxide which depends on the reaction time were evaluated by means of the off-gas analysis. The reduction rate of iron oxide was very fast. The apparent reduction degree of iron oxide above 90% is obtained in about 10 minutes of reaction time. In the initial stage of reaction, up to about 80% of reduction degree of iron oxide, the reaction is controlled by the gasification reaction of carbon. The empirical rate equations for the reduction reaction of iron oxide were derived, and which agreed well with experimental values.

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