• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.2
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• pp.68-72
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• 2004

The performance of copper-tungsten for electrodes used in an ultra high voltage interruption system was evaluated by means of an interruption test, which requires a large-scale apparatus and high cost. In this study, prior to the interruption test, the characteristics of a Cu-W electrode were estimated through the DC arc test, which is a simple, low cost procedure. The DC arc characteristics of a 20wt%Cu-80wt%W electrode were investigated with the change of tungsten powder size distribution and the addition of nickel. In specimens containing a high volume fraction of large sized tungsten particles, the relative density and hardness of sintered Cu-W electrodes increased while the electrical conductivity and the DC arc resistance decreased. Furthermore, the relative density became enhanced with the increase of the amount of nickel while the hardness and electrical conductivity diminished and the DC arc resistance worsened.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.434-435
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• 2009

The crystalline silicon solar cell where the solar cell market grows rapidly is occupying of about 85% or more. high-efficiency and low cost endeavors many crystalline silicon solar cells. the fabrication processes of high-efficiency crystalline silicon solar cells necessitate complicated fabrication processes and Ti/Pd/Ag contact, however, this contact formation processed by expensive materials. Ni/Cu contact formation is good alternative. in this paper, according to temperature Ni silicide makes, produced Ni/Cu contact solar cell and measured conversion efficiency.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.370-371
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• 2006

The particulate strengthened $Cu-MoSi_2$ composites were prepared by a PM process to develop novel copper based composites with reasonable strength, high thermal conductivity and low thermal expansion coefficient. Microstructure of the composites was investigated by SEM; the tensile strength, elongation, thermal conductivity and thermal expansion coefficient (CTE) of the composites were examined. A comparative analysis of mechanical and thermal properties of various Cu-matrix composites currently in use was given and the strengthening mechanisms for the $Cu-MoSi_2$ composites were discussed.

• Journal of the Korean Applied Science and Technology
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• v.9 no.2
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• pp.165-174
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• 1992

The standardized activated sludge for the biodegradation test of anion surfactants has been produced from the collected microorganisms in the soil and the wastewaters treatment plant. The activated sludge was kept under control of the pH, dissolved oxygen, microorganisms and inoculated the basal medium flasks with LAS and LAS mixed with heavy metals [Cd(II), Cu(II), Zn(II)]. Based of results, the inhibition effect(%) of heavy metals in LAS biodegradation were 1. All 1% when LAS 30mg/l-Cd(II), Cu(II) and Zn(II) 0.1mg/l, respectively 2. All 1${\sim}$10% when LAS 30mg/l-Cd(II), Cu(II) and Zn(II) 1mg/l, respectively 3. All 10${\sim}$40% when LAS 30mg/l-Cd(II), Cu(II) and Zn(II) 10mg/l, respectively 4. All 30${\sim}$65% when LAS 30mg/l-Cd(II), Cu(II) and Zn(II) 100mg/l, respectively And toxicity order of heavy metals to the microorganisms in LAS biodegradation were Cd>Cu>Zn in low concentration(0.1${\sim}$1mg/l)and Cd>Zn>Cu in high concentration(10${\sim}$100mg/l).

• Journal of Fisheries and Marine Sciences Education
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• v.10 no.1
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• pp.69-78
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• 1998

Thermal sprayed Cu-Ni alloy coating on the carbon steel was carried out impingement erosion-corrosion test and electrochemical corrosion test in the marine environment. The impingement erosion-corrosion behavior and electrochemical corrosion characteristics of substrate(SS400) and thermal sprayed Cu-Ni coating was investigated, and the corrosion control efficiency of Cu-Ni coating to substrate was estimated quantitatively. Main results obtained are as follows : 1) The weight loss rate of Cu-Ni coating layer by the impingement erosion-corrosion compared with substrate was smaller in high specific resistance solution than in low specific resistance solution. 2) The corrosion potential of Cu-Ni coating layer spray coating in the marine environment became more noble than that of substrate. 3) With the lapse of time, corrosion current density of Cu-Ni coating layer became stable, but that of substrate was increased. 4) As the corrosion control efficiency of Cu-Ni coating layer in the marine environment was over 90%, its anti-corrosion characteristics was excellent.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.4
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• pp.345-351
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• 2017

Single stage water-gas shift reaction has been carried out at a gas hourly space velocity of $150,494h^{-1}$ over $Cu-Ce_{0.8}Zr_{0.2}O_2$ catalysts prepared by a co-precipitation method. Cu loading was optimized to obtain highly active co-precipitated $Cu-Ce_{0.8}Zr_{0.2}O_2$ catalysts for single stage water-gas shift reaction. 80 wt.% $Cu-Ce_{0.8}Zr_{0.2}O_2$ exhibited the excellent catalytic performance as well as 100% $CO_2$ selectivity (CO conversion = 27% at $240^{\circ}C$ for 50 h). The high activity and stability of 80 wt.% $Cu-Ce_{0.8}Zr_{0.2}O_2$ are correlated to low activation energy and large amount of surface Cu atoms.

• Korean Chemical Engineering Research
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• v.51 no.4
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• pp.432-437
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• 2013

The CO preferential oxidation reaction (PROX) has been done using Cu catalytic active species supported on some of mesoporous silica materials which can facilitate the diffusion of the reactants in order to prevent the poisoning of anode active materials by CO molecules during driving polymer electrolyte fuel cells (PEMFC) in this study. As a result when SBA-15 with large pore used as a support showed excellent CO oxidation activity, especially the activity increased in proportion to the amount of supported Cu. Ti components which was inserted to increase the degree of dispersion of Cu, contributed to improving the performance for CO oxidation at low-temperature. The degree of dispersion of Cu ingredients was the best in the catalyst inserted 20 mol-% Ti into the framework of SBA-15, and CO oxidation activity was also improved.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.3
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• pp.319-325
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• 2017

Through silicon via (TSV) technology is extensively used in 3D IC integrations. The special structure of the TSV is realized by CMP (Chemically Mechanical Polishing) process with a high Cu removal rate and, low dishing, yielding fine topography without defects. In this study, we investigated the electrochemical behavior of copper slurries with various inhibitors in the Cu CMP process for advanced TSV applications. One of the slurries was carried out for the most promising process with a high removal rate (${\sim}18000{\AA}/Min$ @ 3 psi) and low dishing (${\sim}800{\AA}$), providing good microstructure. The effects of pH value and $H_2O_2$ concentration on the slurry corrosion potential and Cu static etching rate (SER) were also examined. The slurry formula with a pH of 6 and 2% $H_2O_2$, hadthe lowest SER (${\sim}75{\AA}/Min$) and was the best for TSV CMP. A novel Cu TSV CMP process was developed with two CMPs and an additional annealing step after some of the bulk Cu had been removed, effectively improving the condition of the TSV Cu surface and preventing the formation of crack defects by variations in wafer stress during TSV process integration.

• Current Photovoltaic Research
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• v.3 no.1
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• pp.21-26
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• 2015

High efficiency $Cu(In,Ga)Se_2$ solar cells are generally prepared above $500^{\circ}C$. Lowering the process temperature can allow wider selection of substrate material and process window. In this paper, the three-stage co-evaporation process widely used to grow CIGS thin film at high temperature was modified to reduce the maximum substrate temperature. Below $400^{\circ}C$ the CIGS films show poor crystal growth and lower solar cell performance, in spite of external Na doping by NaF. As a new approach, Cu source instead of Cu with Se in the second stage was applied on the $(In,Ga)_2Se_3$ precursor at $400^{\circ}C$ and achieved a better crystal growth. The distribution of Ga in the films produce by new method were investigated and solar cells were fabricated using these films.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.9
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• pp.4250-4256
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• 2011

Mn catalyst promoted with Cu were prepared and tested for selective catalytic reduction of $NO_x$ with $NH_3$. Performance of each catalyst was investigated for $NO_x$ activity while changing temperature, space velocity, water content and $O_2$ concentration. Hydrogen conversion efficiency of catalyst was also measured in the $H_2$-TPR system. The inhibition effect of water on catalyst was investigated with the on-off control of water supply. High activity of Mn-Cu catalyst was observed for $160{\sim}260^{\circ}C$. It is found that increase of oxygen concentration acts as a promotor to the increase of catalyst activity but water content acts as a inhibitor.