• Journal of Korean Vacuum Science & Technology
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• v.6 no.1
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• pp.16-21
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• 2002

Ti-0 film is a kind of biocompatible surface materials. In this paper, a new method, glow discharge plasma oxidizing, has been used in synthesizing Ti-O gradient films on Ti6A14V substrates. The effects of ion bombardment and process parameters on the structures of titanium oxide layers have been investigated. The results demonstrate that DC glow plasma oxidizing is more efficient in preparation of dense, hard, and high adhesive Ti-O biomedical films on titanium and its alloys. Samples treated by this method show higher hardness values than by others. Especially, in the condition of hollow cathode discharge, the ion bombardment enhances ionization of oxygen, promotes the oxygen permeation and facilitates the formation of the oxide of low valence states of titanium.

• Journal of the Korean Vacuum Society
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• v.8 no.4A
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• pp.438-444
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• 1999

The characterization of the reactively sputtered ITO layer on the PET film has been studied. The PEM device has been used to determine the optimum stoichimetry through control of the amount of oxygen incorporated into the alloy target and the optimum operation conditions to produce films with the highest electrical conductivity and visible transparency. The PEP film was pre-treated under the plasma discharge condition to remove the adsorbed gases and to modify the surface morphology. The results revealed that by adjusting the flow rate of oxygen with the spectral intensity of indium target, the composition of plasma gas can be kept constant during the entire deposition period. The resistivity of ITO film obtained was fond to be about 37$\Omega\Box$, and the transmittance of visual range was about 86%.

• Vacuum Magazine
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• v.1 no.1
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• pp.21-26
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• 2014

The new materials such as graphene and other nano scale structured materials are attracting great attention due to its expandability for the future electronic devices. In this presentation, a variety of analysis techniques will be introduced for the latest new material applications such as graphene and organic materials with number of metals. The basic properties of next generation device should be carefully analyzed without being exposed to ambient surrounding since the physical and chemical properties of new material or interface states are easily and drastically changed by ambient condition. With the combination of the fabrication process and precise analysis instruments, it is expected to set the facilities supporting the nanotechnology industry and other research groups. This system will give strong support nanotechnology and other complex science with qualified data and information on basic knowledge on the new-forthcoming materials for the future.

• Plant Resources
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• v.6 no.1
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• pp.53-56
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• 2003

To develop optimal storage method of root of Anemarrhena Rhizome, which has been grown as major cultural herbal medicine material, root of Anemarrhena Rhizome was stored for 10 months with different packing materials and sealing methods. The loss in dry weight as influenced by packing materials and sealing methods was the lowest at vacuum packing and followed by complete sealing methods with transparent polyethylene film. The rot ratio of root during the storage period was not significantly different among packing materials but was significantly different among sealing conditions. Conclusively vacuum packing and complete sealing with polyethylene film appears to be optimal for storage of Anemarrhena Rhizome.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1400-1407
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• 2005

There are a number of approaches to in situ remediation that are used at contaminated sites for removing contaminants from the contaminated zone without excavating the soil. These include soil flushing, dual phase extraction, and soil vapor extraction. Of these techniques, soil flushing is the focus of the investigation in this paper. The concept of using prefabricated vertical drains(PVDs) for remediation of contaminated sites with fine-grained soils is examined. The PVD system is used to shorten the drainage path or the groundwater flow and promote subsurface liquid movement expediting the soil flushing process. The use of PVDs in the current state of practice has been limited to soil improvement. The use of PVDs under vacuum conditions is investigated using sample soil consisting of silty sand.

• Carbon letters
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• v.10 no.3
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• pp.234-238
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• 2009

The field emitters were fabricated by screen-printing of carbon nanotube paste, and their emission stabilities were evaluated. It was found that the emission stability measured in a sealed device is much higher than that measured in a vacuum chamber in spite of similar pressure. This was because oxygen gas was scarcely remained in the sealed device, while the gas is continuously supplied into the vacuum chamber during the stability measurement. It was found that the plasma treatment etched the protruded CNTs, resulting in the uniform height of CNT tips. As a result, the stability was increased remarkably. It was also found that the stability of CNT paste emitter was improved by electrical aging and that the optimum condition for the aging was varied with the size of emitter.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.10a
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• pp.39-42
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• 2004

Carbon nanofiber/Cu composite powder has been fabricated by electroless plating process. Microstructural evolution of the composite powder after heat treatment under vacuum, hydrogen and air environment was investigated. A dispersed carbon nanofiber coated by copper was produced at the as-plated condition. Carbon nanofiber is coated uniformly and densely with the plate shaped copper particles. The copper plates on the carbon nanofiber aggregate during the thermal exposure at elevated temperature in vacuum and hydrogen in order to reduce surface energy. The thermal exposure of the composite powder in air at $400^{\circ}C$ for 3 hours leads to the spherodization of the composite powder owing to oxidation of copper.

• Journal of Power System Engineering
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• v.15 no.6
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• pp.16-21
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• 2011

Over the past years, many research works have been carried out to investigate the factors which govern the performance of diesel engine. The air pollutant emission from the diesel engine is still a significant environmental concern in many countries. In the present study, new system of smoke filtration of diesel engine is proposed. This new system is using vacuum equipment and filter for capture smoke. To verification new system experiments are performed at diesel vehicle and engine dynamometer. As a result it is founded that smoke is decreased of 67% at vehicle test and decrease of 45.2% at full load condition of engine dynamometer test.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.249-251
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• 2001

A novel technology for recycling valuable metals contained in waste dry-battery by vacuum metallurgy was devised by theoretical analysis. On the condition of the total chamber pressure of 1.013$\upsilon$10$^1$Pa, Hg, Cd and Zn are distilled in the temperature range of 773~973K, Pb is volatilized in the range of 1173~1273K while Mn, Cu, Fe and C are remained in residual. MnO$_2$and ZnO are reduced by carbon in waste dry-battery in 773~1273K. Pure metals including Zn, Cd, Hg and Pb can be recovered respectively from their mixed vapor by fractional condensation. Metal Cu and MnO$_2$can be obtained from the residual by hydrometallguical method. The technology can eliminate the pollution of Cd, Hg and Pb to environment.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.2
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• pp.196-203
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• 2012

When manufacturing die casting mold, generally, the casting layout design should be considered based on the relation between injection system, casting condition, gate system, and cooling system. Also, the extent or the location of product defects were differentiated according to the various relations of the above conditions. High-qualified products can be manufactured as those defects are controled by the proper modifications or the changes of die casting mold with the conditions. In this research, the proper manufacturing method was derived intensively for reducing the defect of the internal porosity of steering wheel housing which is very complicated to achieve a good mold design. The method was also derived for minimizing and for guaranteeing the product quality through the analysis of the casting problem and the deduction of alternative plans.