• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.188-192
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• 2001

Magnetic separation and sulphidization-flotation for recovery of nickel and copper from two types of scraped condenser wastes, containing 8- l4% nickel and 2-4% copper, were studied. The effects of magnetic field intensities, classification, and grinding on the recovery of nickel and copper were investigated. According to the characteristics of nickel and copper in the scraps, classification-magnetic separation, different magnetic field intensities, and stages-grinding-cleaning of rough concentrate were investigated. The nickel concentrates containing 38-65% nickel with 84-97% recoveries and the copper concentrates containing 25-43% nickel with 35-60% recoveries were obtained by classification-magnetic separation. In addition, copper concentrates containing 26-45% copper with 76-88% recoveries were obtained by sulphidization-flotation from magnetic tailings and middling products.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1995.06b
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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.

• Resources Recycling
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• v.12 no.2
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• pp.3-10
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• 2003

Copper oxychloride used as an agricultural fungicide has been recovered from copper-containing waste etchant by the neutralization with alkali hydroxides. Large amount of copper-containing waste etchant is generated from Printed Circuit Board industry. In an environmental and economic point of view, retrieve of the valuable natural resource from the waste is important. Recycling process of copper oxychloride from the waste etchant is discovered through the our study. In the range of reaction temp. 2$0^{\circ}C$-4$0^{\circ}C$, pH 5-7, pure copper oxychloride was able to prepare and the yield of copper oxychloride was higher than 95%. Physical properties of the sample have been characterized using SEM, XRD, TGA, ICP and Atomic absorption spectroscopy.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.243-248
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• 2001

The objective of this study is to investigate the thermal conductivity of cement mortar for apartment housing floor using expansive admixture, copper fiber, cower lathe, hollowed aluminum plate. According to test results, temperature at point (a) located above heating pipe does not show significant variation with age, and temperature at (b), which is located at the finishing surface above heating pipe, and temperature at (c), which is located at center surface between heating pipe has remarkable change. Temperature distribution sat (b) are in order for, structure containing copper fiber>plain structure>structure containing hollowed aluminum plate>structure containing expansive admixture. Temperature distribution, shows high tendency in order for, structure containing copper fiber>structure containing copper lathe>structure containing hollowed aluminum plate>plain structure>structure containing expansive admixture. (a) estimation of temperature distribution is determined with the variation of temperature between (b) point and (c) point during 60 minutes heating.

• Bulletin of the Korean Chemical Society
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• v.17 no.9
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• pp.836-839
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• 1996

A new copper complex containing 2,2'-dipyridylbenzamide(dpba), Cu(dpba)(NO3)2(CH3CN), has been synthesized and characterized. The crystal structure has been determined. Crystal data: space group P212121, Z=8, a=13.911(3) Å, b=16.813(3) Å, c=18.932(3) Å, V=4427.9(1) Å3 and R=0.0674 for 1716 reflections. The copper environment is square pyramidal containing acetonitrile in axial site. Spectroscopic properties has been characterized in solution state. The redox property of the Cu(dpba)(NO3)2 complex is different from that of corresponding copper-dpa complex.

• Journal of the Korean institute of surface engineering
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• v.39 no.5
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• pp.215-222
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• 2006

The passivity behavior of copper anode containing impurities in copper sulfate solution for electrorefining process was studied at several different levels of impurities such as As, Sb, Bi and Pb. The passivity behavior was investigated by electrochemical techniques (galvanostatic, potentiodynamic and cyclic voltammetry tests) and surface analysis (optical microscopy, electron probe microanalysis, scanning electron microscopy). The results were that arsenic, antimony inhibited passivation and bismuth accelerated it and lead containing anode showed different passivity behavior from above anodes. The improved passivity characteristics could be explained by decrease in oxygen content in passivity film which resulted from a reaction among the impurities, oxygen and copper in the anode. The SEM image revealed that arsenic or antimony containing anode exhibited a porous passivity film and bismuth containing anode showed the compact passivity film and lead containing anode had loose passivity film on anode.

• Resources Recycling
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• v.10 no.6
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• pp.15-21
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• 2001

Shape-controlled copper oxides have been recovered from copper-containing waste etchant by neutralization with alkalihydroxide. Large amount of copper-containing waste etchant is generated from Printed Circuit Board industry. In an environmental and economic point of view, retrieve of the valuable natural resource from the waste is important. In recycling process of copper oxide from the waste etchant, reaction temperature controls shapes and sizes of the products. Copper oxide recovered below reaction temperature $40^{\circ}C$ was of a needle shape, while copper oxide comes in a platy shape above $40 ^{\circ}C$ . Physical properties of samples have been characterized using SEM, XRD, TGA and Atomic absorption spectroscopy.

• Bulletin of the Korean Chemical Society
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• v.22 no.4
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• pp.379-382
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• 2001

A new ligand containing the long aliphatic hydrocarbon chain, dipyridylstearylamine (dps) and its copper(Ⅱ) complex, Cu(dps)(NO3)2 have been prepared. The copper complex was characterized structurally and spectroscopically. The XRD crystal structure of the copper complex reveals that copper is octahedrally coordinated by dps and two nitrato ligands. The nitrato groups ligate asymmetrically to the copper. Crystal data are P1bar, a=8.249(2), b=10.416(3), $c=20.915(4)\AA$, $\alpha=86.54(2)$, $\beta=84.026(2)$, $\gamma=72.32(2)^{\circ}$, V=1702.7(7) $\AA3$ , Z=2, ${\lambda}$(Mo $K\alpha)=0.71073\AA$, $\mu=0.689$ mm-1 , T=293(2) K, R=0.0560 for 3529 reflections. The dps and the copper complex are stable in the air and the copper complex exhibits features of typical of other copper(Ⅱ) complexes containing dipyridylamine-based ligand.

• 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.

• Corrosion Science and Technology
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• v.4 no.1
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• pp.19-22
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• 2005

Two Au-Ag-Cu-Pd dental casting alloys (Au:12% and 20%) used. The test solutions used 0.9 % NaCl solution (isotonic sodium chloride solution), 0.9 % NaCl solution containing 1 % lactic acid, and 0.9 % NaCl solution containing 1 % lactic acid and 0.1 mol $dm^{-3}$ $Na_2S$. The surface of two samples in three sample solutions was not natural discoloration during one year. The alloy containing 12 % gold was easily alloyed and the composition was uniform comparing with the alloy containing 20 % gold. The rest potentials have not a little effect after three months. The kinds of metals could not definitely from the oxidation and reduction waves of metal on the cyclic voltammograms. The dissolutions of gold and palladium were 12 % Au sample in the 0.9 % NaCl solution containing 1 % lactic acid and 0.1 mol $dm^{-3}$ $Na_{2}S$. The pH of solution had an affect on dissolution of copper, and sulfur ion had an affect on dissolution of silver. The copper dissolved amount from 20 % gold sample was about 26 times comparing with that of 12 % gold sample in the 0.9 % solution containing 1 % lactic acid. Corrosion products were silver chloride and copper chloride in NaCl solution, and silver sulfide and copper sulfide in NaCl solution containing $Na_{2}S$.