• Journal of Powder Materials
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• v.17 no.4
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• pp.276-280
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• 2010

In the present work, ethylene glycol-based (EG) copper oxide nanofluids were synthesized by pulsed wire evaporation method. In order to explode the pure copper wire, high voltage of 23 kV was applied to the both ends of wire and argon/oxygen gas mixture was used as reactant gas. EG-based copper oxide nanofluids with different volume fraction were prepared by controlling explosion number of copper wire. From the transmission electron microscope (TEM) image, it was found that the copper oxide nanoparticles exhibited an average diameter about 100 nm with the oxide layer of 2~3 nm. The synthesized copper oxide consists of CuO/$Cu_2O$ phases and the Brunauer Emmett Teller (BET) surface area was estimated to be $6.86\;m^2\;g^{-1}$. From the analyses of thermal properties, it is suggested that viscosity and thermal conductivity of EG-based copper oxide nanofluids do not show temperature-dependent behavior over the range of 20 to $90^{\circ}C$. On the other hand, the viscosity and thermal conductivity of EG-based copper oxide nanofluids increase with volume fraction due to the active Brownian motion of the nanoparticles, i.e., nanoconvection.

• Electrical & Electronic Materials
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• v.9 no.8
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• pp.806-812
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• 1996

I-V characteristics of ground electrode fabricated using an aluminium scrap are presented. We fabricated several shapes of aluminium scraps and aluminium electrodes. The results show that the current of aluminium electrode increased linearly by the voltage increase. AC breakdown voltage of copper plate electrode was higher than that of aluminium electrode. AC breakdown current of aluminium electrode was higher than that of copper plate electrode. As applied voltage increased, grounding resistance of aluminum electrode decreased linearly.

• Journal of Powder Materials
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• v.11 no.5
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• pp.383-390
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• 2004

In order to investigate behavior of abnormal expansion of the iron-copper compacts, we compared the dilatometric curves of the compacts which mixed the copper powder to the iron powder with those of compacts which mixed the copper powder to the iron-copper alloy powder. The dilatometric curves were obtained below the sintering conditions, which heated up to 115$0^{\circ}C$ by a heating rate of 1$0^{\circ}C$/min, held for 60min at 115$0^{\circ}C$ and cooled down at a rate of 2$0^{\circ}C$/min to room temperature. The dilatometric curves of the compacts showed the different expansion behavior at temperatures above the copper melting point in spite of same chemical composition. All of the compacts of former case showed large expansion, but all of the compacts in latter case showed large contraction. The microstructures of sintered compacts also showed the different progress in alloying of the copper into the iron powder. Namely we could observe the segregation at alloy part of copper into iron powder in case of the sintered compacts, which mixed the copper powder to the iron powder, but could not observe the segregation in compacts which mixed the copper powder to the iron-copper alloy powder. But the penetration of liquid copper into the interstices between solid particles was occurred at both cases. Therefore, the showing of the different dimensional changes in the compacts in spite of same chemical composition is due to more the alloying of copper into iron powder than the penetration of liquid copper into the interstices between solid particles.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.11a
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• pp.228-231
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• 1995

Phthalocyanine have a good sensitivity to the toxic gases like NO$_2$. Also its properties of good chemical and thermal suability give a potential to superiors gas sensing system. Depositioni of Octa(2-ethyhexyloxy) Copper Phthalocyanine is confirmed by transfers ratio, UB/visible spectra and current-voltage (I-V) characteristics.

• YAKHAK HOEJI
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• v.26 no.3
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• pp.181-184
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• 1982

The iron and copper chelates of 4-dimethylamino-2-formylpyridine thiosemicarbazone, one of the amine substituted derivatives at 4-C of 2-formylpyridine thiosemicarbazones which are known as the more improved potential antitumor agents, have been synthesized to make them more effective than the ligand (denoted as HL) itself. Their ligand-to-metal ratios were 2:1 and 1:1 for the iron and copper chelates, and the data along with those of elemental analysis and IR spectroscopy showed that. the compositions are [$FeI_{2}{\times}2H_{2}SO_{4}$ and [CuL($H_{2}Cl$O)], respectively.

• Applied Chemistry for Engineering
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• v.32 no.2
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• pp.224-227
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• 2021

A rapid and selective copper-catalyzed amination of aryl halides with sodium azide was established by using 10 mol % of CuI, and 20 mol % of N,N'-dimethylethylenediamine in DMSO under microwave irradiation for 10 min. The catalytic system with 4-substituted aryl iodides was found to be the most effective leading to a nearly complete conversion.

• Economic and Environmental Geology
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• v.6 no.3
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• pp.133-170
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• 1973

The metamorphosed belt on cherty and andesitic rocks of the Gyeongnam province area has been well known as the most important copper matallogenetic province in Korea and locally has been investigated by several geologists. This report is summarized about geology, occurrence of ore deposits, the study of the present status of mine developments and exploitations and the suggestions of future proposed of copper mine developments and harmoniously and reseonably planning of demands and supply of copper ore. For convenience of study the writer divided the survey region as 4 areas, according to the conditions of mine location. They are (1) Goseong copper area (2) Gunbuk-Haman copper area (3) Masan-Changwon copper area (4) Tongrae-Ilgwang copper area. The geology of the above 4 areas consits of Cretaceous Gyongsang System, which is divided into Silla series, Nakdong Series and Bulguksa Series. The former has intrusive and extrusive andesite and sedimentary formation, and the latter has dioritic and hornblende granite. Ore deposits which is mostly vein types are confined mostly in the andesite and cherty rocks of Silla and Nakdong Series. It is observed slight hydrothermal alteration, i. e. propylitization, chloritization, saussuritization and silicification. It seems that the ore was formed by hydrothermal solution and secondary enrichement. The ore minerals are mainly chalcopyrite and pyrite, with small amounts of malachite, azurite, chalcocite, cuprite, galena, and sphalerite, magnetite, tetrahedrite and etc.. The efficient plan of copper mine developments in surveyed region are as following; (a) Gyeongnam Copper districts are divided in 4 area as mentioned above. (b) Each area would be likely developed as group-working as one unit. For the sufficiently supplying a demand of electric copper, the importations of high grade copper ore in foreign country are invitable at present status of copper mine developments and exploitations.

• Journal of the Korean Society of Safety
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• v.1 no.1
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• pp.27-32
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• 1986

To remove sulfur dioxide from flue gas by the method of metal oxide, copper powder of average diameter $2.4\mu\textrm{m}$and $51\mu\textrm{m}$ were used in a fixed bed reactor over a, temperature range of $300^{\circ}C-500^{\circ}C$. Copper oxide reacts with sulfur dioxide producing cupric sulfate and it can be regenerated from the latter by using hydrogen or methane. Experimental results showed that the reaction rate was increased by the increase of reaction temperature in the range of $300^{\circ}C-422^{\circ}C$ and the removal efficiency of sulfur dioxide was high in case of small size copper particle. However the removal efficiency was decreased at higher temperature due to decomposition of cupric sulfate. The rate controlling step of this reaction was chemical reaction and deactivating catalysts model can be applied to this reaction. The rate constants for this reaction and deactivation are as follows ： k＝8,367exp(-10,298/RT) Kd＝2.23exp(-8,485/RT)

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2008.11a
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• pp.13-14
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• 2008

A high rate magnetron sputtering source (HRMSS) was employed to deposit thick copper films. The HRMSS was manufactured by changing the magnet size, arrangement, and field intensity. For the preparation of thick copper films, the copper sputtering conditions using HRMSS were characterized based on the deposition parameters such as discharge characteristics, I-V characteristics of the source, and change of deposition rate. The deposition rate of copper turned out to be more than 5 times than that of conventional magnetron sputtering source. Thick copper films having thickness of more than $20{\mu}m$ were prepared by using HRMSS. The morphology and orientation of the films were investigated by scanning electron microscopy and x-ray diffraction.

• Bulletin of the Korean Chemical Society
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• v.15 no.12
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• pp.1112-1118
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• 1994

Epoxidation of olefins has been studied using iodosylbenzene (PhIO) as the terminal oxidant and binuclear and mononuclear complexes of $Mn^{2+}$, $Co^{2+}$, and $Cu^{2+}$ as catalysts. Epoxides were the predominant products with trace amounts of allylic oxidation products, and the metal complexes were found to be effective catalysts in the epoxidation reactions. The reactivity of binuclear copper complexes was greater than that of the mononuclear copper complexes, whereas the binuclear and mononuclear complexes of $Mn^{2+}$ and $Co^{2+}$ showed similar reactivities. The nature of the ligands bound to copper did not influence the reactivity of the binuclear copper complexes so long as copper ions were held in close proximity. A metal-iodosylbenzene complex, such as suggested previously for Lewis acidic metal complex-catalyzed epoxidation by iodosylbenzene, is proposed as the active epoxidizing species. Some mechanistic aspects are discussed as well.