• Title, Summary, Keyword: Copper

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Thick Graphene Embedded Metal Heat Spreader with Enhanced Thermal Conductivity

  • Park, Minsoo;Chun, Kukjin
    • Journal of Sensor Science and Technology
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    • v.23 no.4
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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.

Influence of Alcohol and Low Dietary Copper on Copper Utilization of Maternal and Offspring Liver (임신과 수유기간 동안 Alcohol과 저 Copper 식이가 어미와 새끼 쥐 간의 Copper 수준에 미치는 영향)

  • Lee, Jong Ho
    • Journal of Nutrition and Health
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    • v.23 no.6
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    • pp.443-450
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    • 1990
  • Pregnant rats were fed liquid diet to determine the influence of maternal ethanol intake on maternal and pup liver copper when dietary copper was low. The diets, which contained either 0.75(low) or 3.75(control)mg copper/1 with or without 30% of kcal from ethanol, were fed throughout gestation and the first 15 days of lactation. maternal calorie intake and body weight were unaffected by dietary treatment. Ethanol intake depressed maternal liver copper concentration only when diet copper was low(interactive effect P<0.05). Although ethanol intake depressed total pup liver copper concentration regardless of dietary copper level, the interactive effect observed in maternal liver was reflected incopper content of the pup liver metallothionein fraction eluted from a Sephadex G-75 column. The zinc content of metallothionein was inversely related to copper content of metallothionein. Results suggest that pregnancy and lactation is a special period to develop a copper deficiency when low copper intake and ethanol ingestion are combined not only in mothers but also in their offspring.

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Effect of Copper Retention on Copper Leaching in Wood Treated with Copper-based Preservatives

  • Ra, Jong-Bum;Kang, Sung-Mo;Kang, Shin-Kwon
    • Journal of the Korean Wood Science and Technology
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    • v.37 no.5
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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.

A Study on N-Arylation of Indole Using Copper Nitrate or Copper Carbonate as a Catalyst (Copper Nitrate와 Copper Carbonate를 촉매로 이용한 Indole의 N-Arylation 연구)

  • Lee, Jun Young;Yang, Min Ho;Paik, Seung Uk
    • Applied Chemistry for Engineering
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    • v.19 no.6
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    • pp.629-632
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    • 2008
  • N-Arylation of indole with aryl iodides has been achieved by employing copper nitrate or copper cabonate as a catalyst, which might be more practical and economical over any other copper- or palladium-based catalysts for industrial applications. N,N'-dimethylethylenediamine was found to be the most effective with copper nitrate catalyst systems, while ethylenediamine was the most active with copper carbonate.

Effect of Copper on Callus Formation and Plant Regeneration in Seed Culture of Rice (벼 종자배양에서 Copper가 캘러스 형성 및 식물체 재분화에 미치는 영향)

  • 권용삼;손재근
    • Korean Journal of Plant Tissue Culture
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    • v.28 no.4
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    • pp.205-208
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    • 2001
  • This study was conducted to improve the regeneration efficiency from seed-derived calli of rice by optimizing the copper concentrations in the media. Mature seeds were cultured on MS medium supplemented with copper sulphate (0 to 5.0 mg/L) and 2 mg/L 2,4-D. Callus growth was influenced by the levels of copper sulphate containing with medium, The addition of copper sulphate (2.5 mg/L) in regeneration medium enhanced dramatically the ability of plant regeneration from seed-derived calli. The mean frequency of plant regeneration of 6 indica rices was 27.4% on medium containing copper sulphate, whereas that of the cultivars on copper-free medium was 2.4%. These results suggest that copper sulphate may have an important role in improving regeneration ability of indica rices.

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Molecular Mechanism of Copper Resistance in Pseudomonas syringae pv. tomato.

  • Cha, Jae-Soon;Donald A. Cooksey
    • Proceedings of the Korean Society of Plant Pathology Conference
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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.

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The Effect on Copper Dissolution from Copper Cookware by Acid Condiments (구리냄비의 구리용출에 미치는 산성조미료의 영향)

  • ;;;;南出隆久
    • Journal of the East Asian Society of Dietary Life
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    • v.10 no.3
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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.

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Preparation of Copper Database of Korean Foods and Copper Nutritional Status of Korean Adults Living in Rural Area Assessed by Dietary Intake and Serum Analysis (한국인 상용 식품의 구리영양가표작성과 식이섭취 및 혈청분석에 의한 한국농촌성인의 구리영양상태 평가)

  • 정효지
    • Journal of Nutrition and Health
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    • v.32 no.3
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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.

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Biosorption of Heavy Metal Sons by Biomass of Marine Brown Algae in Cheju using Their immobilization Techniques: Biosorption of Copper by Undaria pinnatifida

  • Sang-Kyu Kam;Min-Gyu Lee
    • Journal of Environmental Science International
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    • v.1 no.2
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    • pp.157-166
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    • 1992
  • The biosorptlon 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 biosorptioydesorption cycles. There was no damage to the immobilized biomass which retained its macroscopic appearance in repeated copper uptake/elution cycles.

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Biosorption of Heavy Metal lons by Biomass of Marine Brown Algae in Cheju using Their Immobilization Techniques: Biosorption of Copper by Undaria pinnatifida

  • Kam Sang-Kyu;Lee Min-Gyu
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • v.1 no.2
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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.

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