• 한국재료학회지
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• 제4권4호
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• pp.393-400
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• 1994

1$\mu \textrm{m}$이하의 텅스텐 분말에 구리를 균일하게 코팅하는 공정을 새로이 개발했다. 구리가 코팅된 $\mu \textrm{m}$이하의 텅스텐 분말을 이용하여 액상소결하였으며, 구리가 균일하게 분포된 W-Cu합금을 얻을 수있었다. 본 연구에서 개발된 방법에 의해 구리의 함유량을 10wt.%이하로 낮추면서도 균일한 W-Cu합금을 얻을 수 있었으며, 특히 코발트를 같은 방식에 의해 첨가하면 구리액상이 형성된 후 급격히 치밀화하여 96% 이상의 상대밀도를 갖는 W-Cu 합금을 제작하는데 성공하였다. 코발트 첨가에 의한 급격한 치밀화의 증가는 텅스텐과 구리액상 사이의 접착성 향상에 기인하는 것으로 밝혀졌다.

• 한국세라믹학회지
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• 제54권1호
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• pp.61-65
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• 2017

Examined in this study were the effects of copper oxide (II) addition and sintering conditions on the chromatic characteristics of copper glaze. Oxidatively sintered samples exhibited the negative increase of $CIEa^*$ and the positive increase of $CIEb^*$ with the increase of CuO concentration, leading to Green and Green-Yellow coloration. On the other hand, $CIEa^*$ and $CIEb^*$ of reductively sintered samples were positively increased in direct proportion. The green color of oxidatively sintered samples was originated from the $Cu^{2+}$ ions formed by the dissolution of CuO. The reductively sintered samples resulted in dull tone red color with low chroma. Such behavior seems to be influenced by the interplay of metal Cu aggregation, metal Cu globule, and $Cu_2O$ formed in the glaze layer through the redox interaction of CuO during the sintering process.

• Corrosion Science and Technology
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• 제18권2호
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• pp.39-48
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• 2019

The feasibility of using benzotriazole (BTAH) to inhibit pitting corrosion in the sprinkler copper tubes was investigated by filling the tubes with BTAH-water solution in 829 households at an eight-year-old apartment complex. The water leakage rate was reduced by approximately 90% following BTAH treatment during 161 days from the previous year. The leakage of one of the two sprinkler copper tubes was investigated with optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction analysis to determine the formation of Cu-BTA film inside the corrosion pits. All the inner components of the corrosion pits were coated with Cu-BTA films suggesting that BTAH molecules penetrated the corrosion products. The Cu-BTA film was about 2 nm in thickness at the bottom of a corrosion pit. A layer of CuCl and $Cu_2O$ phases lies under the Cu-BTA film. This complex structure effectively prevented the propagation of corrosion pits in the sprinkler copper tubes and reduced the water leakage.

• Bulletin of the Korean Chemical Society
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• 제23권3호
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• pp.404-412
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• 2002

Nine copper(Ⅱ) oxyanion, and mixed oxyanion complexes that have four- or five-coordinate geometries around copper(Ⅱ) centers were derived from sparteine copper(Ⅱ) dinitrate precursor [Cu($C_{15}$$H_{26}$N2)(NO3)2]. The precursor complex undergoes an anion exchange with various oxyanions, and an interchange reaction with other sparteine copper(Ⅱ) complexes. The [Cu($C_{15}$$H_{26}$N2)(CH3CO2)2] also undergoes "halogen atom abstraction" reaction with CCl4 to produce the mixed anion complex [Cu($C_{15}$$H_{26}$N2)(CH3CO2)Cl]. The whole set of prepared complexes has been used for the comparative electrochemical and spectroscopic studies.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.812-813
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• 2006

Dimensional change of compact made from (Fe-Cu) prealloyed powder and copper powder compared to that of compact made from iron-copper elemental powder. The compact made from the prealloyed powder with a copper content of 7.18mass% which is nearly equal to its solution limit and copper powder showed only the large contraction in spite of penetration of liquid copper into grain boundary of the prealloyed powder. But the compact made from iron-copper elemental powder showed the large expansion in spite of same chemical composition with former case.

• Asian-Australasian Journal of Animal Sciences
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• 제23권5호
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• pp.573-579
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• 2010

This study was conducted to determine the effects of different copper (inorganic and organic) and energy (tallow and glycerol) sources on growth performance, nutrient digestibility, gas emission, diarrhea incidence, and fecal copper concentration in growing pigs by using a 2${\times}$2 factorial design. In this trial, 96 pigs (63 d of age) were employed, with an average initial weight of 28.36${\pm}$1.14 kg. The dietary treatments were i) basal diet with 134 ppm copper (Korea recommendation) as $CuSO_4$+tallow; ii) basal diet with 134 ppm Cu as $CuSO_4$+glycerol; iii) basal diet with 134 ppm copper as CuMet+tallow; and iv) basal diet with 134 ppm copper as CuMet+ glycerol. Throughout the entire experimental period, no differences were noted among treatment groups with regard to the magnitude of improvement in ADG (average daily gain), ADFI (average daily feed intake) and G/F (gain:feed) ratios. The nitrogen (N) digestibility of pigs fed on diets containing organic copper was improved as compared with that observed in pigs fed on diets containing inorganic copper (p<0.05). An interaction of copper${\times}$energy was observed in the context of both nitrogen (p<0.05) and energy (p<0.01) digestibility. Ammonia emissions were significantly lower in the organic copper-added treatment groups than in the inorganic copperadded treatment groups (p<0.05). Mercaptan and hydrogen sulfide emissions were reduced via the addition of glycerol (p<0.05). No significant effects of copper or energy source, or their interaction, were observed in reference to diarrhea appearance and incidence throughout the entirety of the experimental period. The copper concentration in the feces was significantly lower in the organic copper source treatment group than was observed in the inorganic copper source treatment group (p<0.05). The results of this experiment show that organic copper substituted for inorganic copper in the diet results in a decreased fecal copper excretion, but exerts no effect on performance. The different energy (tallow and glycerol) sources interact with different copper sources and thus influence nutrient digestibility. Glycerol supplementation may reduce the concentrations of odorous sulfuric compounds with different Cu sources.

• 열처리공학회지
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• 제33권4호
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• pp.185-192
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• 2020

In this study, materials characterization of pure copper and copper based carbon nano-tube composite prepared by powder metallurgy method were investigated. Prior to evaluate materials characterization, spark plasma sintering processing variables such as sintering temperature, pressure, thickness and diameter of compacts was optimized to ensure the microstructure and materials property of pure Cu and Cu-CNT composite. In addition, corrosion behavior of Cu-based CNT composite produced by powder sintering method was investigated. It was confirmed from this study that the corroded surfaces of the composite shows less dissolution compared with pure copper in 3.5 wt% NaCl solution. The measured corrosion current density (I_corr) indicates improved corrosion property of Cu based composite containing small additions of CNTs in chloride containing media. Micro-galvanic activity between Cu and CNT was not observed in given sintering condition.

• 한국광물학회지
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• 제23권3호
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• pp.243-250
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• 2010

인도네시아 잠비산 복합 동광석을 대상으로 고품위 동 정광생산을 위한 부유선별 연구를 수행하였다. 본 연구에 사용된 시료는 대부분 탄산염인 공작석으로 이루어져 있으나, 일부 황화동이 존재하여 자연부유도가 높은 황화동을 먼저 부유선별에 의해 회수한 다음, 침강산물로부터 산화동 회수를 위한 공정을 적용하였다. 먼저 황화동 부유선별에서는 잔세이트(xanthate) 계열의 포수제인 AP-211과 AP-242를 1 : 1의 비율로 300 g/t 첨가하고, 광액 pH 6인 조건에서 Cu 품위와 회수율이 각각 57.7%와 9.5%인 동 정광을 얻었다. 그리고 침전된 산물을 대상으로 지방산 포수제인 올레인산을 300 g/t, 기포제 첨가량 50 g/t, 광액 pH 8.0, 그리고 정선횟수 2회인 조건에서 Cu의 품위와 회수율이 각각 30.8%와 92.1%인 결과를 얻었다. 회수된 황화동 및 산화동 정광을 합산한 결과 최종적으로 Cu의 품위와 회수율이 36.1%와 92.7%인 결과를 얻었다.

• Asian-Australasian Journal of Animal Sciences
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• 제24권7호
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• pp.1001-1006
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• 2011

To determine the efficiency of copper (Cu) supplementation, a feeding experiment was carried out with 240 day old broiler chicks (vencobb-100). Birds were divided into four dietary treatments: i) C - no additives, ii) $T_1$-75 mg inclusion of Cu/kg diet, iii) $T_2$-150 mg inclusion of Cu/kg diet, iv) $T_3$-250 mg inclusion of Cu/kg diet. The present study was carried out in the Department of Animal Physiology, West Bengal University of Animal and Fishery Sciences, Kolkata, India for a period of 42 days (6 weeks). Growth performance was measured in terms of live weight gain, cumulative feed intake and feed conversion ratio at the end of $21^{st}$ and $42^{nd}$ day of the experiment and the result was found to be encouraging for commercial enterprises when the chickens were fed at 150 mg Cu/kg ($T_2$) of their diet. Excess dietary copper more than 150 mg/kg reduced the haemoglobin (Hb) concentration in blood and resulted in the accumulation of copper in the liver with decreased blood Hb concentration and packed cell volumes (PCV). Copper supplementation increased the total erythrocyte count (TEC) as copper is involved in erythropoiesis. But, from the result it is indicated that the dietary copper concentration could not alter the total leukocyte count (TLC). In case of different leucocytes count (DLC), there were no significant differences observed among the different treated groups. Statistical analysis showed significant (p<0.01) difference in plasma concentration of copper, zinc, ferrous and cholesterol among the different copper treated groups. The result indicates that supplementation of copper is an effective way of improving the production performance and haematological parameters in broiler chicken.

• 약학회지
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• 제9권1_2호
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• pp.8-13
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• 1965

The sensitivity on microorganisms of ten sulfa-drugs and their Cu-complexes was observed. Ericsson's disc method and modified tube dilution method were applied. Dimethylformamide was used for solvent of sulfa drugs. In general, original sulfa-drugs showed more sensitive patterns than its Cu-complexes except sulfadimethoxine-Cu complex which showed more sensitive patterns than its original drug with disc method.