• 센서학회지
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• 제23권4호
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• pp.234-237
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• 2014

In this paper, a copper foil-thick grapheme (thin graphite sheet)-copper foil structure is reported to achieve mechanically strong and high thermal conductive layer suitable for heat spreading components. Since graphene provides much higher thermal conductivity than copper, thick graphene embedded copper layer can achieve higher effective thermal conductivity which is proportional to graphene/copper thickness ratio. Since copper is nonreactive with carbon material which is graphene, chromium is used as adhesion layer to achieve copper-thick graphene-copper bonding for graphene embedded copper layer. Both sides of thick graphene were coated with chromium as an adhesion layer followed by copper by sputtering. The copper foil was bonded to sputtered copper layer on thick graphene. Angstrom's method was used to measure the thermal conductivity of fabricated copper-thick graphene-copper structure. The thermal conductivity of the copper-thick graphene-copper structures is measured as $686W/m{\cdot}K$ which is 1.6 times higher than thermal conductivity of pure copper.

• Journal of Nutrition and Health
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• 제32권3호
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• pp.296-306
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• 1999

This study was carried out to prepare a copper database of Korean foods which can be used in calculating copper intake from dietary data, and to evaluate the copper nutritional status of Koran adults living in rural areas by dietary intake and serum copper concentrations. A copper database for 1,176 Korean foods was constructed (1) by analysing 112 Korean foods which are frequently consumed by Korean adults living in rural areas, (2) by adapting values form food composition databases from other countries-320 items from the University of Minnesota database, 201 items from the USAD database, and 25 items from U.K. database, and (3) by imputing values from similar foods for 518 food items. Copper intake of 2,034 Korean adults over the age of 30 living in Yeonchongun was Kyunggi province, Korea was estimated by 24-hour recall method. Mean daily copper intake of subjects was 0.98mg. Mean daily intake level of males was 1.11mg which was significantly higher than that of females, 0.88mg. There was a significant difference in the distribution of subjects by the level of copper intake and sex(p<0.05). Mean serum copper concentration was 14.8umol/1 and the percentage of subjects with low, adequate, and high levels of copper concentration were 23.9%, 69.4%, and 6.6%, respectively. The two food groups which contributed most to the dietary copper intake of subjects were cereals and grain products, and vegetables, supplying 46.2% and 12.7% of total copper intake, respectively. Individuallym, rice contributed most, suppling 31% of total copper intake, followed by soybean curd, starch vermicle, barley, etc. Plant foods contributed to 82.1% of the total copper intake. In summary, results of this study show that copper intake of Korean adults living in rural areas is low, and that dietary sources of copper are mainly plant foods. Serum levels of copper in the subjects were relatively normal. The copper database for Korean foods constructed in present study will be a valuable tool for the as-yet limited assessment of copper intake of Koreans. Such studies will contribute to the establishment of a dietary of a dietary allowance of copper and the relationship of copper nutriture and chronic diseases in Koreans.

• Journal of Nutrition and Health
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• 제23권6호
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• pp.443-450
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• 1990

임신과 수유 기간 동안 alcohol의 섭취가 어미와 새끼 쥐의 간내 copper 유용에 미치는 영향을 연구하기 위하여 cthanol(0 혹은 30%의 Kcal)과 copper(0.75 혹은 3.75mg/l 식이) 함량에 차이를 둔 식이조성으로 alcohol과 copper의 상호작용을 규명하는 factorial experiment를 수행하였다. 어미 쥐의 열량 섭취와 체중은 식이들에 의해 영향을 받지 않았다. 식이내 copper양이 적을 경우 alcohal을 섭취하지 않은 실험군과 비교하여 alcohol을 섭취한 실험군인 어미 쥐의 간 copper농도가 더욱 감소됨으로써 alcohol과 copper의 상호작용을 보여주었다. 새끼 쥐에게서는 식이내 copper 수준에 관계 없이 어미쥐의 alchol 섭취가 간의 총coppernein의 copper 농도에 반영되었다. Metallothionein의 zinc 함량은 metallothionetin의 copper함량과 반비례적인 관계로 보여주었다. 이상의 결과로 임신과 수유기 동안 식이내 copper함량이 적을 경우 alchol 섭취는 어미와 새끼 모두에게 copper 결핍을 초래할 수 있다는 것을 시사해준다.

• Journal of the Korean Wood Science and Technology
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• 제37권5호
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• pp.421-425
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• 2009

This research investigates the effect of copper retention on copper leaching in wood treated with copper-based preservatives. Radiata pine (Pinus radiata D. Don) sapwood samples were ground in a Wiley mill equipped with a 20-mesh screen. The ground wood was vacuum-treated with various concentrations of alkaline copper quat (ACQ), bis-(N-cyclohexyl-diazeniumdioxy)-copper (CB-HDO), and copper azole (CUAZ). The treated samples were conditioned at $70^{\circ}C$ and 100% RH for 72 hours. The samples were leached by using the distilled water for four weeks, and the copper contents in each sample were measured by X-ray spectroscopy. As expected, the copper leaching was increased with increasing of copper retention. The copper leaching from the ACQ and CB-HDO treated samples were gradually decreased with increasing copper retention: however, the copper losses from the CUAZ treated samples appeared to be proportionally increased with the increase in copper retention in all retention levels tested. The results indicate that at the conditions of the same copper retention ACQ and CB-HDO treated wood have a better leaching resistance compared to CUAZ treated wood.

• 동아시아식생활학회지
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• 제10권3호
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• pp.239-244
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• 2000

Effects of acetic acid, malic acid and citric acid on copper dissolution from new and used copper saucepans at different concentrations (0, 0.02. 0.04, 0.1 0.2, 0.4, 1.0, 2.0, 4.0%), different boiling times (0,10, 20. 30, 40, 50, 60mins.), and different temperatures (5, 20, 40, 60, 80, 10$0^{\circ}C$ ) were investigated. As acetic acid concentration increases, copper content increases. Copper dissolution concentration from copper saucepans at boiling in malic acid increases more than in acetic acid or citric acid. At above 6$0^{\circ}C$, as the temperature increases, the concentration of copper dissolved from copper saucepans also increases. As boiling time increases, the concentration of copper dissolved from copper saucepans also increases. In addition, through repeated use, the concentration of copper increases as well. And copper concentration dissolves in large amounts from used saucepans rather than new saucepans. The dissolution of copper with distilled water by repeated use does not dissolve at all. 1% acetic acid dissolves in large quantities.

• 공업화학
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• 제19권6호
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• pp.629-632
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• 2008

N-Arylation에 대한 경제적이고 실용적인 촉매시스템을 찾기 위하여 indole을 이용한 다양한 반응조건에서 실험이 수행되었으며, 결과적으로 본 연구에서 처음 시도한 copper nitrate와 copper cabonate가 다른 copper계 촉매나 palladium 촉매에 유사하거나 더 우수한 반응성을 보여주었다. Copper nitrate 촉매를 사용하는 경우에는 다양한 리간드 중에서 N,N'-dimethylethylenediamine 리간드가 더 효과적이었으며 copper cabonate 계에서는 ethylenediamine 리간드가 더 적합한 것으로 판명되었다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 1995년도 Proceedings of special lectures on Molecular Biological Approaches to Plant Disease National Agricultural Science and Technology Institute Suwon, Korea
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• pp.97-117
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• 1995

Copper resistance in Pseudomonas syringae pv. tomato is determined by copper-resistance operon (cop) on a highly conserved 35 kilobase plasmid. Copper-resistant strains of Pseudomonas syringae containing the cop operon accumulate copper and develop blue clonies on copper-containing media. The protein products of the copper-resistance operon were characterized to provide an understanding of the copper-resistance mechanism and its relationship to copper accumulation. The Cop proteins CopA (72 kDa), CopB (39 kDa), and CopC (12 kDa) were produced only under copper induction. CopA and CopC were periplasmic proteins and CopB was an outer membrane protein. Leader peptide sequences of CopA, CopB, and CopC were confirmed by amino-terminal peptide sequencing. CopA, CopB, and CopC were purified from strain PT23.2, and their copper contents were determined. One molecule of CopA bound 10.9${\pm}$1.2 atoms of copper and one molecule of CopC bound 0.6${\pm}$0.1 atom of copper. P. syringae cells containing copCD or copBCD cloned behind the lac promoter were hypersensitive to copper. The CopD (32 kDa), a probable inner membrane protein, function in copper uptake with CopC. The Cop proteins apparently mediate sequestration of copper outside of the cytoplasm as a copper-resistance mechanism.

• 식물조직배양학회지
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• 제28권4호
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• pp.205-208
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• 2001

벼의 종자배양에서 식물체 재분화 능력을 향상시키기 위하여 2 mg/L의 2,4-D와 여러 가지 농도의 copper (0~5.0mg/L)가 첨가된 MS배지에 종자배양 한 바 캘러스 생장정도는 copper 농도에 따라 다르게 나타났는데 특히, 2.5 mg/L의 copper가 첨가된 배지에서 가장 양호하였다. 그리고 캘러스 형성률과 copper 농도 간에는 유의성 있는 차이가 인정되지 않았다. 식물체 재분화 배지에 2.5 mg/L의 copper의 첨가는 Indica 품종들의 식물체 재분화 효율을 크게 향상시켰다. Copper가 첨가되지 않은 N$_{6}$배지에서 Indica 6품종의 평균재분화율은 2.4%이었으나, copper가 첨가된 배지에서 27.4%로 높게 나타났다.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제1권2호
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• pp.157-166
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• 1997

The biosorption performances of copper were investigated by the immobilized biomass of nonliving marine brown algae Undaria pinnatifida by each of the Ca-alginate method(Ca-ALG), Ba-alginate method(Ba-ALG), polyethylene glycol method(PEG), and carrageenan method (CARR). The copper removal performance increased but the copper uptake decreased as the biomass amount was increased. However, the copper uptake by the immobilized biomass increased with increasing initial copper concentration. Among the immobilization methods, the copper uptake decreased in the following sequence: Ca-ALG > Ba-ALG > PEG > CARR. The pattern of copper uptake by the immobilized biomass fitted the Langmuir isotherm better than the Freundlich isotherm. Desorption of deposited copper with 0.05 ~0.5M HCI, resulted in no changes of the copper uptake capacity of the immobilized biomass by the immobilization methods except for PEG, through five subsequent biosorption/desorption cycles. There was no damage to the immobilized biomass which retained its macroscopic appearance in repeated copper uptake/elution cycles.

• Tribology and Lubricants
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• 제36권4호
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• pp.207-214
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• 2020

In this study, we investigated the effects of copper and copper-alloy on the frictional and wear properties of low-steel friction material. The proportions of copper and copper-alloy in the brake friction materials used in passenger cars are very high (approximately 5-20% weight), and these materials have significant effects on friction and wear characteristics. In this study, the effects of cupric ingredients, such as the copper fiber and brass fiber, are investigated using the friction materials based on commercial formulations. After the copper and brass fibers from the same formulation were removed, the frictional and wear characteristics were evaluated to determine the influence of the copper and copper-alloy. We evaluated the frictional and wear characteristics by simulating various braking conditions using a 1/5 scale dynamometer. The results show that the friction material containing copper and brass fibers have excellent frictional stability and a low wear rate compared to the friction material that does not contain copper and brass fibers. These results are attributed to the excellent ductility, moderate melting point, high strength, and excellent thermal conductivity of copper and copper-alloy. We analyzed the surfaces of the friction materials before and after the performing the friction tests using a scanning electron microscope-energy dispersive X-ray spectroscope, confocal microscope, and roughness tester to verify the frictional behavior of copper and copper-alloy. In future studies, it will be applied to the development of copper-free friction materials based on the results of this study.