• 소성∙가공
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• 제6권2호
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• pp.136-144
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• 1997

(Ag-10%Ni)/Cu clad metals for electric contact switch were fabricated by cold-roll bonding process. 2 or 3 passes of cold-rolling was carried out for each process to investigate the effect of the rolling passes on the bonding property. The effect of the annealing temperature of copper before the cold-roll bonding on the bond strength was also studied. The specimen bonded with copper annealed below 30$0^{\circ}C$ before roll bonding showed good bond strength. This is because high stored energy in copper promoted the short range diffusion and the grain refinement of copper by the static recrystallization increased the degree of the interfacial coherency. The maximum peel strength of clad metals bonded with Cu annealed below 30$0^{\circ}C$ was 120N.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.435-437
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• 2002

Polishing of copper, a process called copper chemical mechanical polishing, is a critical, intermediate step in the planarization of silicon wafers. During polishing, the electrodeposited copper films are removed by slurries: and the differential polishing rates between copper and the surrounding silicon dioxide leads to a greater removal of the copper. The differential polishing develops dimples and furrows; and the process is called dishing and erosion. In this work, we present the results of experiments on dishing and erosion of copper-CMP, using patterned silicon wafers. Results are analyzed for the pattern factors and properties of the copper layers. Three types of pads - plain, perforated, and grooved - were used for polishing. The effect of slurry chemistries and pad soaking is also reported.

• Asian-Australasian Journal of Animal Sciences
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• 제12권4호
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• pp.548-553
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• 1999

An experiment was conducted to study the effects of high dietary copper supplementation on the gastrointestinal tract morphology of broiler chickens. Eighty 3-week-old broiler chicks were divided randomly into eight groups of four dietary treatments and over three week were fed isoenergetic and isonitrogenous diets that contained 0, 100, 250, or 500 mg/kg of supplemental copper from cupric sulfate. The copper supplementation in the broiler diet up to 250 mg/kg did not significantly influence broilers' performance. A high dietary copper supplementation of 500 mg/kg did significantly depress growth and feed conversion in the broilers (p<0.05). Copper supplementation more than 250 mg/kg in the broiler diet significantly influenced the morphology of the GI tract, as shown by severe oral lesions and gizzard erosion. It also significantly depressed the villi height and significantly thickened the muscular layer in the duodenum (p<0.05). The severely damaged villi were observed by scanning electronic microscope from the duodenum samples of broilers fed a 500 mg/kg copper supplemented diet. The 500 mg/kg copper supplemented diet also significantly influenced the plasma constituents. Plasma glucose concentration was significantly depressed (p<0.05).

• 식물병연구
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• 제11권2호
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• pp.115-121
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• 2005

본 연구는 2003년부터 2005년까지 감귤원에서 구리제의 효율적인 사용을 위하여 주요 감귤 병에 대한 구리제의 방제 효과, 구리피해 발생시기 및 구리제 종류 별 구리피해 정도, 그리고 기계유유제와의 혼용에 대한 효과를 구명하고자 실시하였다. 결과를 종합하면 감귤더뎅이병에 대한 방제효과는 구리제 종류에 관계없이 방제가가 약 $75\%$, 궤양병에 대해서도 $85\~88\%$, 그리고 검은점무늬병에 대해서는 약 $75\~86\%$이었다. 구리피해는 새순이 어릴수 록 발생이 심하였고 과일의 경우 고온기인 7월부터 8월까지가 가장 심하였다. 또한 구리제에 응애 방제용 기계유유제를 혼용하여 살포할 경우 방제 효과는 그대로 유지하였지만 구리피해는 상당히 감소하였으며 이들 결과들로부터 구리제와 기계유유제를 혼용하여 적기에 사용할 경우 봄철 더뎅이병과 궤양병, 그리고 응애를 동시에 방제할 수 있으며 유기농이나 무농약 재배 과원에서도 효율적으로 사용할 수 있을 것으로 생각된다.

• Progress in Superconductivity
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• 제12권2호
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• pp.93-98
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• 2011

Pinning force is the mechanism between a superconductor and a permanent magnet and it provides a stable levitation. However, when external force greater than the pinning force such as the earthquake exerts, the levitated object may lose the levitating characteristic. In order to achieve more stabilized levitation, the copper plate was inserted in between a superconductor and permanent magnets. And by applying the eddy current effect caused from the relationship between a copper plate and permanent magnets, more stabilized levitation can be established. In this study, an optimized design was found based on various configurations of permanent magnet's polarity, thickness and area of copper plate, and the gap distance between copper plate and permanent magnet. As results, higher eddy current value was obtained at where the change of polarity exists in permanent magnet configuration, and the highest eddy current value was observed at the copper plate thickness of 5 mm and the area of 80 mm ${\times}$ 80 mm. From the resulted optimized conditions above, which are 7 mm gap distance between a superconductor and permanent magnets and 80 mm ${\times}$ 80 mm ${\times}$ 5 mm dimension of a copper plate, the stiffness value was 65 % increased comparing to without any copper plate insertion.

• 분석과학
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• 제8권4호
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• pp.611-615
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• 1995

The design of appropriate chemically modified electrodes should allow development of new voltammetric measurement schemes with enhanced selectivity and sensitivity. Microorganism like algae has high ability to trap toxic and heavy metal ions and different affinities for metal ions. A copper(II) ion-selective carbon paste electrode was constructed by incorporating alga Anabaena into a conventional carbon paste mixture, and then the film of 10% Nafion was coated to avoid the swelling of the electrode surface. Copper ion could be deposited at the 25% algamodified electrode for 15 min without the applied potential while stirring the solution by only immersing the electrode in a buffer (pH 4.0) cot1taining copper(II). Temperature was controlled at $35^{\circ}C$. After preconcentration was carried out the electrode was transferred to a 0.1 M potassium chloride solution and was reduced at -0.6 volt at $25^{\circ}C$. The differential pulse anodic stripping voltammetry was employed. A well-defined oxidation peak could be obtained at -0.1 volt (vs SCE). In five deposition / measurement / regeneration cycles, the responses were reproducible and relative standard deviations were 3.3% for $8.0{\times}10^{-4}M$ copper(II). Calibration curve for copper was linear over the range from $2.0{\times}10^{-4}M$ to $1.0{\times}10^{-3}M$. The detection limit was $7.5{\times}10^{-5}M$. Studies of the effect of diverse ions showed that the coexisting metal ions had little or no effect for the determination of copper. But anions such as cyanide. oxalate and EDTA seriously interfered.

• 한국표면공학회지
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• 제29권4호
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• pp.238-252
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• 1996

In order to study the effect of interface oxides on the adhesion strength of the copper/epoxy system, copper foils were immersed in black oxide or brown oxide forming solutions before lamination with epoxy prepregs, and variation of peel strength with the treatment time were investigated. Results showed that peel strength decreased rapidly up to 1 minute of treatment lime and remained constant in the case of the black oxide treated specimens, which was accompanied by the thickening of $Cu_2O$ at the Copper/Epoxy interface during the period. In contrast, peel strength increased rapidly up to 1 minute of treatment time and remained constant in the case of the brown oxide treated specimens, which could be ascribed to the thickening of CuO. Subsequent heat treatments of the Copper/Epoxy laminations at $120^{\circ}C$ in air showed that peel strength remained constant in the case of the black oxide treated specimens but decreased gradually in the case of the brown oxide treated specimens. Following XPS analyses revealed that the latter was possibly caused by the coalescence of CuO at the Copper/Epoxy interface into $Cu_2O$.

• 한국재료학회지
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• 제17권1호
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• pp.56-59
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• 2007

Recently, requirement for the ultra thin copper foil increases with smaller and miniaturized electronic components. In this study, we evaluated the surface morphology, crystal phase ana surface roughness of the copper film electrodeposited by pulse method without using additives. Homogeneous and dense copper crystals were formed on the titanium substrate, and the optimum condition was 25% duty cycle. Moreover, the surface roughness(Ra), $0.295{\mu}m$, is the smallest value in this condition. It is thought that this copper foil is good for electromigration inhibition due to the preferential crystal growth of Cu (111)

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.71-71
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• 2010

Copper oxide thin films were deposited on the p-type Si(100) by r.f. magnetron sputtering as a function of different substrate temperature. The deposited copper oxide thin films were investigated by atomic force microscopy (AFM), scanning electron microscopy (SEM), spectroscopic ellipsometry (SE), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The SEM and SE data show that the thickness of the copper oxide films was about 170 nm. AFM images show that the surface roughness of copper oxide films was increased with increasing substrate temperature. As the substrate temperature increased, monoclinic CuO (111) peak appeared and the crystal size decreased while the monoclinic CuO (-111) peak was independent on the substrate temperature. The oxidation states of Cu 2p and O 1s resulted from XPS were not affected on the substrate temperature. The contact angle measurement was also studied and indicated that the surface of copper oxide thin films deposited high temperature has more hydrophobic surface than that of deposited at low temperature.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2013년도 춘계학술대회 논문집
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• pp.179-179
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• 2013

Surface resistance of electro-deposited copper with its thickness, current density and surface roughness was determined by using a 4-point probe analyzer. The copper was prepared electrochemically on 316 stainless steel substrate in copper sulfate solution at the condition of $1A/dm^2$, 298 K, and 6.5 cm-electrode distance. The surface resistance of the copper sheet in the range of $0.93-0.97{\Omega}$ increased with the copper thickness in the range of $21-70{\mu}m$. The surface resistance in the range of $0.963-1.009{\Omega}$ also increased with current density in the range of $0.5-2A/dm^2$. The increased surface resistances corresponded to 11% for thickness and 25% for current density, respectively.