• 한국결정성장학회지
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• 제8권1호
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• pp.131-137
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• 1998

구리입자를 코딩한 분말 합성은 Kelex 100 solvent extraction으로부터 silica powder에 수소압력 stripping copper에 의하여 생성하였다. Solvent extraction의 범위내인 일정한 조건에서 loading level과 stripping rate등을 재생하였으며 stripping copper kinetics는 divalent상태에서 metallic 상태로 감소하면서 silica 입자에 침적하였다. Copper들은 seed 입자에 heterogeneous 핵을 형성하면서 이들은 agglomeration 상태로 생성되었고 불균일한 분말로 형성하였다.

• 한국수산과학회지
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• 제30권5호
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• pp.874-881
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• 1997

곤쟁이 Neomysis awatschensis의 치하와 성체에 대한 중금속의 급성독성 수준과 아치사 농도에서 생존, 성장, 탈피 및 산소소비에 미치는 cadmium, copper 및 chromium의 독성을 검토하였다. Cadmium, copper 및 chromium에 대한 곤쟁이 성체의 $96hr-LC_{50}$은 각각 20.2, 11.3, $670.4\;{\mu}g/\ell$, 치하에서는 각각 3.4, 1.9 및 $49.4\;{\mu}g/\ell$이었다. 성체와 치하의 $96hr-LC_{50}$을 기준으로 중금속의 독성은 copper>cadmium>chromium 순이었다. 치하를 각 중금속의 아치사 농도에 40일간 노출시키면서 생존, 성장 및 탈피에 미치는 영향을 조사한 결과, 생존율은 cadmium이 $\geq1.0\;{\mu}g/\ell,\;copper\geq0.6\;{\mu}/\ell$에서 유의한 감소를 보였다. 성장률은 cadmium $2.0\;{\mu}g/\ell$와 copper $\geq1.2\;{\mu}g/\ell$의 농도에서 유의한 감소가 관찰되었으나 탈피기간에는 영향이 없었다. 산소소비량은 중금속 농도가 높을수록 감소하였고, 대조구의 산소소비량을 기준으로 하여 중금속 농도에 따른 산소 소비량은 cadmium과 copper는 $5\;{\mu}g/\ell$ chromium은 $10\;{\mu}g/\ell$ 농도에서 약 $50\%$ 감소하였다. 이상의 결과로부터 하구역에 cadmium이 $\geq1.0\;{\mu}g/\ell$, copper가 $\geq0.6\;{\mu}g/\ell$ 농도가 존재할 경우 곤쟁이의 분포와 개체군의 크기에는 많은 영향을 미칠 것으로 사료된다.

• Journal of Microbiology
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• 제34권2호
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• pp.172-178
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• 1996

Methylobacillus sp. strain SK1, which grows only on methanol, was found to grow in the absence of added copper. The doubling time (t$_{d}$ = 1.3 h) of the bacterium growing at the exponential growth phase at 30.deg.C in the absence of copper was the same as that of the cell growing in the presence of copper. The bacterium growing after the exponential phase in the absence of copper, however, grew faster than the cell growing in the presence of copper. Cells harvested after thee arly stationary phase in the presence of copper were found to exhibit no methanol dehydrogenase (MDH) activity, but the amount and subunit structure of the enzyme in the cells were almost the same as that in cells harboring active MDH. Pellets of the cells harvested after the early stationary phase in the presence of copper were pale green. Cell-free extracts prepared from cells harvested at the early stationary phase in the presence of copper were pink and exhibited MDH activity, but it turned dark-green rapidly from the surface under air. The green-colored portions of the extracts showed no MDH activity and contained c-type cytochromes that were oxidized completely. The inactive MDH activity and contained c-type cytochromes that were oxidized completely. The inactive MDH proteins in the green portions were found to have antigenic sites identical to those of the active one as the inactive MDHs in cells grown in the presence of copper. The bacterium was found to accumulate copper actively during the exponential growth phase. MDH prepared from cells grown in the presence or absence of copper was found to be more stable under nitrogen gas than under air. Methanol at 10 mM was found to enhance the stability of the MDH under air.r.

• 농업과학연구
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• 제48권3호
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• pp.447-454
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• 2021

This study was conducted to evaluate the effects of different copper sources (inorganic and organic) on the growth performance, fecal copper excretion, intestinal morphology, and health in growing pigs. A total of 40 growing pigs (30.22 ± 1.92 kg) were randomly assigned to 5 dietary treatments: a basal control diet (CON), 4 experimental diets supplemented with either copper sulfate (CuSO₄), Cu-glycine complex (CuGly), Cu-amino acid complex (CuAA), or Cu-hydroxy-4-methylthio butanoate chelate complex (CuHMB) at 100 ppm, respectively. At the end of the study (28 days), fecal and blood samples were collected, and the pigs were slaughtered to determine the intestinal morphology. During the 28 days of the experimental period, pigs fed the inorganic and organic copper showed a higher average daily gain (p < 0.01) and gain feed ratio (p < 0.01). There were no differences in mineral concentrations of the serum; however, the copper concentration of the feces was lower (p < 0.01) in the CuAA and CuHMB groups. The intestinal morphology and blood profiles did not significantly differ between the groups. In conclusion, the organic copper sources (CuAA and CuHMB) can be used as a growth promoter to replace the CuSO₄ without any negative effects on health in growing pigs and to reduce fecal copper excretion.

• 전기학회논문지P
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• 제56권1호
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• pp.37-44
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• 2007

This paper describes characteristics for copper oxide growth of polyvinyl chloride(PVC) insulated wires by series arc. In this experiment, 600V IV wires were used, and characteristics of oxide growth and ignition process were analyzed in case load was 300W, 460W and 600W, respectively. In the result of experiment, covering materials were molten, carbonized and ignited, whereas, oxidized materials were grown in conducting material. During copper oxide was growing, contact voltages and power dissipations increased. When there is copper oxide growth, the waveform of current showed sinusoidal waveform, and the waveform of voltage showed modified waveform. Oxidized materials were heated at about $905^{\circ}C$, surface structure showed irregular shapes, and cross-section showed multiple cracks. And, the results of this experiment were applied to the fire cause analysis of fire evidence collected at the fire scene.

• 한국분말재료학회지
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• 제12권6호
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• pp.413-421
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• 2005

Copper is able to work as a current collector under wide range of hydrocarbon fuels without coking in Solid oxide fuel cells (SOFCs). The application of copper in SOFC is limited due to its low melting point, which result in coarsening the copper particle. This work focuses on the sintering of copper powder with ceria coating layer. Ceria-coated powder was prepared by thermal decomposition of urea in $Ce(NO_3)_3\cdot6H_2O$ solution, which containing CuO core particles. The ceria-coated powder was characterized by XRD, ICP, and SEM. The thermal stability of the ceria-coated copper in fuel atmosphere $(H_2)$ was observed by SEM. It was found that the ceria coating layer could effectively hinder the grain growth of the copper particles.

• 한국표면공학회지
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• 제49권3호
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• pp.238-244
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• 2016

Copper electrodeposition on AZ91 Mg alloy was studied in views of preferential deposition on ${\alpha}$- or ${\beta}$- phases and how to achieve uniform deposition over the entire surface on ${\alpha}$- and ${\beta}$-phases in a cyanide solution. The inhomogeneous microstructure of AZ91 Mg alloy, particularly ${\alpha}$- and ${\beta}$-phases, was found to result in non-uniform deposition of zincate layer, preferential deposition of zincate on ${\beta}$-phases, which leads to non-uniform growth of copper layer during the following electrodeposition process. The preferential depositions of zincate can be attributed to higher cathodic polarizations on the ${\beta}$-phases. Pin-hole defects in the copper electrodeposit were observed at the center of large size ${\beta}$-phase particles which is ascribed to gas bubbles formed at the ${\beta}$-phases. The activation of AZ91 Mg alloy in hydrofluoric acid solution was used to obtain uniform growth of zincate layer on both the ${\alpha}$- and ${\beta}$-phases. By choosing an optimum activation time, a uniform zincate layer was obtained on the AZ91 Mg alloy surface and thereby uniform growth of copper was obtained in a cyanide copper electroplating solution.

• Journal of Microbiology and Biotechnology
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• 제11권2호
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• pp.211-216
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• 2001

The growth of Selenastrum capricornutum in culture was investigated as a function of ionic copper concentrations to verify the toxicity and physiological variation. In a $Cu^{++}$ excess culture (E: $Cu^{++}$ of $130{\mu}g/l$), the growth rate (K)(0.32) was lower than that of the control culture (C: $Cu^{++}$ of $0.065{\mu}g/l$) (0.61) after 8 days and the exponential growth rate ($R_E$) was also found to be lower in culture E (1.1) than culture C (2.9). On the contrary, the K of S. capricornutum in trace $Cu^{++}$ culture ($T_1$ and $T_2$, 0.72) after 6 days tended to be more increased than culture C (0.68). From 8 to 14 days of culture, the amounts of chlorophyllls a and b were increased in culture C (chlorophyll a, $106->126{\mu}g/g$ dry wt; chlorophyll b, $158->208{\mu}g/g$ dry wt; chlorophyll b were decreased in culture E (chlorophyll a, $309->235{\mu}g/g$ dry wt; chlorophyll b, $405->352{\mu}g/g$ dry wt). The amounts of chlorophylls in ionic copper trace culture ($T_1$ and $T_2$) [(chl a/b) of $T_1$: $384/620\;{\mu}g/g$ dry wt; (chl a/b) of $T^2$:$320/467{\mu}g/g$ dry wt] were increased more than the culture C($260/387{\mu}g/g$ dry wt). Howeveer, when photosynthetic rates were normalized to the dry weight of algae, the control culture continued to showed higher values than the treated culture ($T_1$). An appropriate amount of ionic copper ($T_1:\;26\;{\mu}g/l$) stimulated the grwoth of S. capricornutum than the ionic copper content of $13\;{\mu}g/l$ ($T_2$), while the excess amount of ionic copper ($130\;{\mu}g/l$) resulted in the highest toxicity to the growth of S. capricornutum.

• Journal of Nutrition and Health
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• 제31권4호
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• pp.756-766
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• 1998

The objectives of this study were to examine the growth pattern and hair trace element contents of healthy infants who were fed breast milk(BF infant) and formula (FF infant) during the first 6 months and its relationship to intake of trace elements. Bimonthyl anthropometric measurements were obtained on 32 infants through 6 months of age. Mean calculated energy, iron, zinc and copper intake from breast milk at 2 months of age were 432.4kcal/d, 0.19mg/d, 1.18mg/d and 0.22mg/d. The values obtained from formular were543.7kcal/d, 6.68mg/d , 2.82mg/d and 0.33mg/d , respectively. In spite of the significantly lower intake of energy and trace elements in BF infants than in FF infants, BF infants showed growth above the average Kroean infant standard growth rate and showed no significant growth rate difference or hair trace element content. Hair iron content in the BF infants at 6 mo. of age was positively related to birth weight and iron intake at 2 mo. of age. In contrast, hair zinc and copper content in the FF infants at 6 mo. of age as negatively related to height increment and weight increment during 6 months, respectively. These results support the suggesting that BF infant's higher iron, zinc and copper intake is attributed to the superior bioabailability of these trace elements from breast milk.

• 한국결정성장학회지
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• 제3권1호
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• pp.75-84
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• 1993

황산동 수용액으로부터 치환법을 이용하여 흑연입자에 동을 코팅시켰다. 흑연입자표면에 연속적이고 균질하게 동이 코팅된 최적조건을 확립하기 위하여 동이온 농도, 교반속도, 반응시간 및 반응온도 등의 영향을 조사하였다. 이때 동 코팅반응의 활성화에너지는 3.59kcal/mole이었다.