• Title, Summary, Keyword: Copper

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Effect of Copper on the Plant Regeneration from Seed Derived Callus of Orchardgrass (Dactylis glomerata L.) (오차드그래스의 종자유래의 캘러스로부터 식물체 재분화율에 미치는 Copper의 영향)

  • 이효신;이병현;원성혜;이상현;조진기
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.20 no.4
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    • pp.259-264
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    • 2000
  • This study was conducted to investigate the effects of copper in the efficiencies of callus formation and plant regeneration of orchardgrass (Dactylis glomarata L.). Seeds were cultured on MS medium containing $2\;mg/{\ell}$ 2,4-D and different concentrations ($0.1-100\;{\mu}mol$) of copper sulfate. Plant regeneration was achieved on N6 medium containing $1\;mg/{\ell}$ NAA, $5\;mg/{\ell}$ kinetin and $0.1-100\;{\mu}mol$ of copper sulfate. Callus formation was not affected by copper incorporation into MS medium. However, the efficiency of plant regeneration was promoted by copper and the maximum efficiency was obtained when $70\;{\mu}mol$ copper was incorporated in the culture medium. The average number of regenerated plants from the seed-derived callus was also increased by copper.

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Effects of Copper and Copper-Alloy on Friction and Wear Characteristics of Low-Steel Friction Material (로우스틸 마찰재의 마찰 및 마모특성에 미치는 구리계 재료의 영향)

  • Jung, Kwangki;Lee, Sang Woo;Kwon, Sungwook;Choi, Sungwoo;Lee, Heeok
    • Tribology and Lubricants
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    • v.36 no.4
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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.

Feasibility of Copper Powder Fabrication by Ball Milling of Copper Chip Scrap Occurred During Cutting Process of Copper Pipe (구리 관(管)의 절단(切斷) 공정(工程)중 발생한 구리칩 스크랩의 볼밀링에 의한 구리 분말(粉末) 제조(製造) 가능성(可能性))

  • Hong, Seong-Hyeon
    • Journal of the Korean Institute of Resources Recycling
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    • v.20 no.6
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    • pp.37-42
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    • 2011
  • Copper chip scrape has been occurred by cutting of copper pipe. The feasibility of copper chip scrape into the copper powder by milling was studied. Two milling type such as rod milling and horizontal balling milling were applied in this research. Copper chip can not fragmented into powder by using rod milling. In contrast to rod milling, copper chip can be changed into powder by horizontal ball milling for above 36 hours. It was found that recycling of copper chip scraps into copper powder by horizontal ball milling is possible and powder fraction percent ($75{\sim}150{\mu}m$) of milled copper chip for 48 hours is 25.3%.

Electroless Copper Plating For Metallization of Electronic Devices

  • Lee Jae-Ho
    • Journal of the Microelectronics and Packaging Society
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    • v.11 no.4
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    • pp.75-80
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    • 2004
  • In copper metallization, resistivity of copper seed layer is very important. Conventionally MOCVD has been used for this purpose however electroless copper plating is simple process and the resistivity of copper deposit is less than that of copper prepared by MOCVD. In this study electroless copper plating was conducted on different substrate to find optimum conditions of electroless copper plating for electronic applications. To find optimum conditions, the effects and selectivity of activation method on several substrates were investigated. The effects of copper bath composition on morphology were investigated. The effects of pH and stabilizer on deposition rate were also investigated. The optimum pH of the bath was 12 with addition of stabilizer. The resistivity of copper was decreased with addition of stabilizer and alter heat treatment.

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Investigation on Causes of Pitting Corrosion in Sprinkler Copper Tubes (스프링클러 동배관의 공식부식 발생원인)

  • Lee, Jae-Bong;Jung, Hoseok
    • Corrosion Science and Technology
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    • v.13 no.1
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    • pp.6-14
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    • 2014
  • Copper metal is widely used in tubes installed in sprinkler water services because of its excellent corrosion resistance. Copper corrosion is considered to be insignificant in water system and the incident of copper pipeline failure is relatively low. However, pitting corrosion is a major problem with all copper tubes. In this study, leaked sprinkler copper tubes were collected from three different locations and examined on the causes of pitting corrosion of copper tubes in sprinkler water plumbing systems. Electrochemical tests such as potentiodynamic polarization, as well as surface and chemical analyses were performed. Results show that pitting corrosion of copper tubes were found as Type I pitting that the carbon film formed on the copper tubes have a harmful effects, causing the pinhole failure in the pipe and resulting in leakage of water. The contermeasures on Type I pitting corrosion of copper tubes were proposed.

The Analysis of Voltage Waveform and Oxidation Growth of Conductor with Series Arc (직렬 아크에 따른 도체의 산화물 증식 및 전압 파형 분석)

  • Choi, Chung-Seog;Kim, Hyang-Kon;Kim, Dong-Ook;Kim, Dong-Woo
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.55 no.3
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    • pp.146-152
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    • 2006
  • In order to analyze the characteristics of series arcs that could happen in poor connections of electrical facilities, we made an apparatus which is similar to actual situation. series arcs are generated between copper and copper, copper and bronze, copper and brass, bronze and bronze, and then oxidation growth and voltage waveform were measured. A very small vibration with constant movement is needed to grow oxidation initially, whereas oxidation growth proceeded without a vibration after a certain amount of time. At first, blue white flame was generated initially between copper and copper, and then yellow flame was generated. In case of contact between copper and copper, the length of oxidation growth was about 7.1[mm] in 90[min]. In case of contact between copper and brass, the length of oxidation growth was about 4.3[mm] in 90[min], When bronze is contacted with copper, the lengths of oxidation growth were about 1.4[mm] in 20[min] and 2.7[mm] in 40[min] respectively, and no more oxidation growth was shown after that. In case of contact between brass and brass, the length of oxidation growth was about 1.2[mm] in 90[min], so it was the smallest compared to other cases. When copper is contacted with copper, the current through the load was about 1.6[A] and the power dissipation increased from 19[W] to 31[W]. In case of oxidation growth between copper and brass, the voltage changed from 8.4[V] to 11[V]. However, the voltage drop and the power dissipation between copper and brass were small compared to oxidation growth between copper and copper. When series arcs were generated between bronze and copper, a peak was shown at the beginning of voltage increase, and 40[min] later, oxidation material was not grown any longer. When oxidation growth occurred, voltage waveform showed irregular waveforms with tiny ripples.

Adhesion between Rubber Compound and Copper-Film-Coated Steel Plate Prepared by Vacuum Sputtering and Substitution Plating Methods (진공증착법과 치환도금법으로 제조한 구리박막 피복철판과 배합고무의 접착)

  • Moon, Kyung-Ho;Han, Min-Hyun;Seo, Gon
    • Journal of Adhesion and Interface
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    • v.4 no.3
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    • pp.1-8
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    • 2003
  • Adhesion between rubber compound and copper-film-coated steel plate (abbreviated hereafter as copper film plate) with different thicknesses of copper film was investigated. Two different methods were employed for the preparation of the copper film plates: a substitution plating of preelectroplated zinc with copper ion and a vacuum sputtering of copper on steel plate. Adhesion strength of the copper film plates with rubber compounds was largely dependent upon the thickness of copper film, regardless of their preparation methods. The copper film plates with thinner thickness than 75 nm showed high adhesion comparable to brass, while those with thicker copper film showed poor adhesion due to excessive growth of copper sulfide at adhesion interface.

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The Usage of Copper Slag as The Drainage Materials (동 수매 슬래그의 배수용 재료로써의 이용)

  • 민덕기;황광모;이경준;김현도
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.453-458
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    • 2001
  • Copper slag is produced about 700,000 tons annually though copper refining process in Korea. In the paper, a laboratory investigation was carried out to estimate the geotechnical properties of copper slag and examine the feasibility of using the copper slag as a substitute for conventional construction materials and the improvement of the soft clay deposit. The specific gravity of copper slag is 3.45, and pH is 7.83. And the size distribution of the copper slag is well graded, so usage of copper slag will be extended in Geotechnical engineering fields. Copper slag has the permeability of 3.502${\times}$10 ̄$^2$cm/sec, which is satisfied with the criterion of sand drainage materials.. At the same time, it is thought to be suitable material for sand mat since it meets JIS of grain size distribution. The content of CaO from steel slag is about 40 percent while that of CaO from copper slag is about 5 percent. Based on this fact, copper slag has less hardening property compared to steel slag. Therefore, copper slag can be used as vertical drains, filters, and sand mats for improving the soft deposit.

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Recovery of Copper from Spent Copper Solution of Printed Circuit Board Process by Solvent Extraction Method (인쇄회로기판 제조과정에서 발생되는 동폐액의 용매추출에 의한 재활용)

  • Moon, Young-Hwan
    • Clean Technology
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    • v.2 no.1
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    • pp.47-52
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    • 1996
  • The solvent extraction method was applied on a spent solution containing copper, which was produced in a printed circuit board process, to recover copper and to reuse the etching solution. Lix 64 N ($\alpha$-Hydroxyoxime + $\beta$-Hydroxybenzophenone Oxime) was used as a solvent. The acidic spent copper solution was mixed with and alkaline copper solution to pH=2. The solvent including 30 volume% of Lix 64 N extracted 17.1gr/l of copper from the mixed spent copper solution. In the continuous bench scale experiment, 4 stages for extraction, 2 stages for stripping and 4 stages for washing were used. Recovered copper was recycled as copper sulfate and the raffinate was reused as copper etchant. The percentage of copper recovery and the purity of copper sulfate were higher than 99.9%, respectively.

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Recovery of Copper Powder from MoO3 Leaching Solution (MoO3 침출공정 폐액으로부터 동분말의 회수기술)

  • Hong, Hyun-Seon;Jung, Hang-Chul;Kim, Geun-Hong;Kong, Man-Sik
    • Journal of Korean Powder Metallurgy Institute
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    • v.16 no.5
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    • pp.351-357
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    • 2009
  • A two-step recovery method was developed to produce copper powders from copper chloride waste solution as byproducts of MoO$_3$ leaching process. The first step consisted of replacing noble copper ions with external Fe$^{3+}$ ions which were formed by dissolving iron scraps in the copper chloride waste solution. The replaced copper ions were subsequently precipitated as copper powders. The second step was cementation of entire solution mixture to separate (pure) copper powders from aqueous solution of iron chloride. Cementation process variables of temperature, time, and added amount of iron scraps were optimized by using design of experiment method and individual effects on yield and efficiency of copper powder recovery were investigated. Copper powders thus obtained from cementation process were further characterized using various analytical tools such as XRD, SEM-EDS and laser diffraction and scattering methods.Cementation process necessitated further purification of recovered copper powders and centrifugal separation method was employed, which successfully yielded copper powders of more than 99% purity and average 1$\sim$2$\mu$m in size.