• 한국수소및신에너지학회논문집
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• 제8권3호
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• pp.137-141
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• 1997

The effects of Ag addition to Zr-based hydrogen storage alloys ($Zr_{0.7}Ti_{0.3}V_{0.4}Ni_{1.2}Mn_{0.4}$, $Zr_{0.7}Ti_{0.3}V_{0.4}Ni_{1.2}Mn_{0.3}Cr_{0.1}$ and $Zr_{0.6}Ti_{0.4}V_{0.4}Ni_{1.2}Mn_{0.3}Fe_{0.1}$) on the electrode properties were examined. Ag-free and Ag-added Ze-based alloys were prepared by arc melting, crushed mechanically, and subjected to the electrochemical measurement. In $Zr_{0.7}Ti_{0.3}V_{0.4}Ni_{1.2}Mn_{0.4}$ alloy, 0.08 wt% Ag addition to the alloy improved the activation rate. Also Ag addition improved both activation property and discharge capacity in $Zr_{0.7}Ti_{0.3}V_{0.4}Ni_{1.2}Mn_{0.3}Cr_{0.1}$. For these Ag-added alloys, discharge capacities with the change of charge-discharge current density(10mA, 15mA and 30mA) are almost constant. Showing very high rate capability, discharge capacity of $Zr_{0.6}Ti_{0.4}V_{0.4}Ni_{1.2}Mn_{0.3}Fe_{0.1}$ alloy increased by Ag addition to the alloy. When the amount of Ag addition in $Zr_{0.7}Ti_{0.3}V_{0.4}Ni_{1.2}Mn_{0.4}$ alloy increased too much, the electrode properties became worse. Unveiling mechanism of effect of Ag addition is now progressing in our laboratory.

• 한국측량학회지
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• 제17권1호
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• pp.69-78
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• 1999

최근 급속한 산업발전으로 환경오염에 대한 인식이 고조되고 있으며 오염방지에 대한 방법 및 기술 또한 다각적으로 연구되고 있다. 과거에는 환경오염에 대한 대응방향이 오염물질의 농도저감과 처리기술 개발등에 국한되어 왔으나 현재는 오염물질의 관리 및 평가와 같은 좀더 고차원적인 연구로 전환되고 있다. 본 연구에서는 환경정보 시스템구축에 대한 개념을 수립하고 그 기법을 제시하였으며 오염원과 오염부하량에 따른 환경정보의 데이터베이스 설계, 질의, 분석 그리고 출력기법을 개발하였다. 또한, LANDSAT TM 영상을 이용하여 토지이용도를 작성하였으며, PC상에서 Excel과 PC ArcView 프로그램간에 동적데이터교환을 이용하여 폐수배출시설허가관리대장 관리를 가능하게 하여 기존 GSIS용 프로그램의 문서관리에 대한 취약성을 극복할 수 있었다.

• 한국표면공학회지
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• 제24권1호
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• pp.24-24
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• 1991

Cr-N films were deposited on low-carbon steel sheets by the reactive arc-induced ion plating (AIIP). The influence of the deposition conditions (nitrogen pressure and substrate bias voltage) on the crystal orientation, morphology and microhardness of the Cr-N films has been investigated using x-ray diffractometer and scanning electron microscope. The impurities and contaminations on the surface and at the interface, and the layer-by-layer compositions of the film have been analyzed using scanning Auger multiprobe (SAM) and glow discharge spectroscope (GDS). The mixed state of Cr and Cr2N turned out to have a fine fibrous structure. The Cr2N films were deposited at a wide range of nitrogen flow rates. The orientations of Cr2N films were mainly (110) and (111), and the intensity of the (111) peak increased as the substrate bias voltage increased. The micorstructure of the Cr2N film was dense and no columnar structure was observed. The films in the mixed state of Cr2N and CrN were also dense without columnar structure. The maximum microhardness of the Cr-N films was 2400 kg/$\textrm{mm}^2$ at 10gf load.

• 한국대기환경학회지
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• 제26권6호
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• pp.624-632
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• 2010

Perfluorocarbons (PFCs) are widely used in semiconductor industry. These gases need to be removed efficiently because of their strong absorption of infrared radiation and long atmospheric lifetimes which cause the global warming effect. To destruct $CF_4$, a waterjet gliding arc plasma was designed and manufactured. The highest $CF_4$ destruction showed at waterjet plasma case, compared to plasma discharge only or water scrubber only, respectively. In addition, it could be known that the $CF_4$ destruction should be associated with the electron and OH radicals. The operating conditions such as waterjet flow rate, initial $CF_4$ concentration, total gas flow rate, specific energy input were investigated experimentally using a plasma waterjet scrubber. Through the parametric studies, the highest $CF_4$ destruction of 94.5% was achieved at 0.2% $CF_4$, 2.1 kJ/L SEI, 20 L/min total gas flow rate and 18.5 mL/min waterjet flow rate.

• 한국표면공학회지
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• 제25권1호
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• pp.24-33
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• 1992

Cr-N films were deposited on low-carbon steel sheets by the reactive arc-induced ion plating (AIIP). The influence of the deposition conditions (nitrogen pressure and substrate bias voltage) on the crystal orientation, morphology and microhardness of the Cr-N films has been investigated using x-ray diffractometer and scanning electron microscope. The impurities and contaminations on the surface and at the interface, and the layer-by-layer compositions of the film have been analyzed using scanning Auger multiprobe (SAM) and glow discharge spectroscope (GDS). The mixed state of Cr and Cr₂N turned out to have a fine fibrous structure. The Cr₂N films were deposited at a wide range of nitrogen flow rates. The orientations of Cr₂N films were mainly (110) and (111), and the intensity of the (111) peak increased as the substrate bias voltage increased. The microstructure of the Cr₂N film was dense and no columnar structure was observed. The films in the mixed state of Cr₂N and CrN were also dense without columnar structure. The maximum microhardness of the Cr-N films was 2400 kg/㎟ at 10 gf load.

• Transactions on Electrical and Electronic Materials
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• 제14권2호
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• pp.71-77
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• 2013

Advanced semiconductor manufacturing technology requires methods to maximize tool efficiency and improve product quality by reducing process variability. Real-time plasma process monitoring and diagnosis have become crucial for fault detection and classification (FDC) and advanced process control (APC). Additional sensors may increase the accuracy of detection of process anomalies, and optical monitoring methods are non-invasive. In this paper, we propose the use of a chromatic data acquisition system for real-time in-situ plasma process monitoring called the Plasma Eyes Chromatic System (PECS). The proposed system was initially tested in a six-inch research tool, and it was then further evaluated for its potential to detect process anomalies in an eight-inch production tool for etching blanket oxide films. Chromatic representation of the PECS output shows a clear correlation with small changes in process parameters, such as RF power, pressure, and gas flow. We also present how the PECS may be adapted as an in-situ plasma arc detector. The proposed system can provide useful indications of a faulty process in a timely and non-invasive manner for successful run-to-run (R2R) control and FDC.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2016년도 학술발표회
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• pp.187-187
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• 2016

High intensity of population distribution in deltaic setting especially in Asia tends to have increased and causes coastal flood risk due to lower elevations and significant subsidence. Maximum or peak discharge of flood always causes numerous deaths and huge economic losses. New technology of spatial satellite image has been applied to analyze flood damage. In this research, the relationship of nightlight intensity associated with flood damages has been determined during 1992-2013 with spatial resolution of 30 arc sec ($0.0083^{\circ}$) which is nearly one kilometer at the equator in whole six countries along the Mekong River (i.e., China, Myanmar, Lao PDR, Thailand, Cambodia and Vietnam). ArcGIS Hydrological Flow Length Tool has been used to determine the distance of each pixel areas from the rivers and streams. Statistical analysis results highlight the significant correlation R = 0.47 between nightlight digital number and economic damages per unit area (US$/km2) and R = 0.62 for number of affected people for unit area ($people/km^2$). The areas near by the Mekong River and its tributaries correspond to high flood damage. This spatial analysis result is going to be prestigious key information to the regions and all related stakeholders for decisions and mitigation strategies.

• 한국기후변화학회지
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• 제8권1호
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• pp.63-71
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• 2017

It is recognized that tetrafluoromethane ($CF_4$) has a great influence on global warming. The $CF_4$ is known to have a large impact on climate change due to its large global warming index. In this study, a waterjet plasma scrubber (WPS) was designed and manufactured for the $CF_4$ decomposition. The WPS is a novel technology which is combined a gliding arc plasma and water injection at the center of the plasma discharge. This can give an innovative way for $CF_4$ decomposition by achieving larger plasma columnand generating OH radicals. A performance analysis was achieved for the design factors such as waterjet flow rate, total gas flow rate, consumption electric power, and electrode gap. The highest $CF_4$ decomposition and energy efficiencies were 64.8% and 6.43 g/kWh, respectively; Optimal operating conditions were 20 mL/min of waterjet flow rate, 200 L/min total gas flow rate, 5.3 kW consumption electric power, and 4.4 mm electrode gap. As for the 2 stage reactor of the WPS, the $CF_4$ decomposition efficiency improved as the 85.3% while the energy efficiency decreased as the 5.57 g/kWh.

• The Korean Journal of Ceramics
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• 제2권4호
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• pp.216-220
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• 1996

In the present paper, a new type of DC arc plasma torch is disclosed. The principles of the new magnetic and fluid dynamic controlled large orifice long discharge tunnel plasma torch is discussed. Two series of DC Plasma Jet diamond film deposition equipment have been developed. The 20kW Jet equipped with a $\Phi$70 mm orifice torch is capable of deposition diamond films at a growth rate as high as 40$\mu\textrm{m}$/h over a substrate area of $\Phi$65 mm. The 100kW high power Jet which is newly developed based on the experience of the low power model is equipped with a $\Phi$120 mm orifice torch, and is capable of depositing diamond films over a substrate area of $\Phi$110 mm at growth rate as high as 40 $\mu\textrm{m}$/h, and can be operated at gas recycling mode, which allows 95% of the gases be recycled. It is demonstrated that the new type DC plasma torch can be easily scaled up to even higher power Jet. It is estimated that even by the 100kW Jet, the cost for tool grade diamond films can be as low as less than ＄4/carat.

• Journal of Welding and Joining
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• 제32권3호
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• pp.27-33
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• 2014

This paper presents a brief summary on a relatively new plasma aided electrolytic surface treatment process for light metals. A brief discussion regarding the advantages, principle, process parameters and applications of this process is discussed. The process owes its origin to Sluginov who discovered an arc discharge phenomenon in electrolysis in 1880. A similar process was studied and developed by Markov and coworkers in 1970s who successfully deposited an oxide film on aluminium. Several investigation thereafter lead to the establishment of suitable process parameters for deposition of a crystalline oxide film of more than $100{\mu}m$ thickness on the surface of light metals such as aluminium, titanium and magnesium. This process nowadays goes by several names such as plasma electrolytic oxidation (PEO), micro-arc oxidation (MOA), anodic spark deposition (ASD) etc. Several startups and surface treatment companies have taken up the process and deployed it successfully in a range of products, from military grade rifles to common off road sprockets. However, there are certain limitations to this technology such as the formation of an outer porous oxide layer, especially in case of magnesium which displays a Piling Bedworth ratio of less than one and thus an inherent non protective oxide. This can be treated further but adds to the cost of the process. Overall, it can be said the PEO process offers a better solution than the conventional coating processes. It offers advantages considering the fact that he electrolyte used in PEO process is environmental friendly and the temperature control is not as strict as in case of other surface treatment processes.