• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.669-670
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• 2010

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.2
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• pp.194-199
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• 2012

Liver and pulmonary artery tissue from 5 Angus cross bred steers, 6 goats, and 6 pigs were collected at a commercial abattoir to examine the relationship of pulmonary artery copper (Cu) concentrations and genes involved in copper homeostasis. Liver and pulmonary artery samples were collected at the time of harvest and snap frozen. Liver and pulmonary artery Cu concentrations were determined via flame atomic absorption spectrophotometry and gene expression was determined via real time PCR. Liver Cu concentrations (mg Cu/kg DM${\pm}$SE) were higher (p<0.01) in cows ($396.4{\pm}109.1$) and goats ($181.4{\pm}37.0$) than in pigs ($19.2{\pm}3.5$). All liver Cu concentrations were within normal ranges and considered adequate for each species. Liver Cu concentration was more variable in cows and goats compared to pig liver Cu concentrations. Pulmonary artery ${\beta}$-hydroxylproline was higher (p<0.01) in cow and pig than goat. Real Time PCR revealed that goat liver atp7a was positively correlated ($r^2$ = 0.92; p<0.01) to liver Cu concentrations while cow and pig atp7a was not correlated to liver Cu concentration. In the pig, liver atp7a concentration was positively correlated to atp7b ($r^2$ = 0.66; p<0.05). Pulmonary artery Cu concentration was highest in cows ($14.9{\pm}4.7$), intermediate in pigs ($8.9{\pm}3.3$), and lowest in goats ($3.9{\pm}1.1$). Goat pulmonary artery Cu concentration was not correlated to ctr1 concentration, however, atp7a concentration was positively correlated with ctr1 ($r^2$ = 0.90; p<0.01). In cow pulmonary artery, loxl1 concentration was positively correlated to eln mRNA concentration ($r^2$ = 0.91; p<0.02). Pulmonary artery CTR1 protein concentration was positively correlated to pulmonary artery Cu ($r^2$ = 0.85; p = 0.03) concentration while negatively correlated to liver Cu ($r^2$ = -0.79; p<0.04). Pulmonary artery Cu concentration was not correlated to concentration of Cu homeostatic genes in the pig. These data indicate that genes involved in Cu homeostasis (ctr1, atp7A, atp7B, loxl1 and eln) are differently regulated in different species.

• Journal of Powder Materials
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• v.10 no.4
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• pp.270-274
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• 2003

Recently, the fabrication process of W-Cu nanocomposite powders has been researched to improve the sinterability by mechanochemical process (MCP), which consists of ball milling and hydrogen-reduction with W- and Cu-oxide mixture. However, there are many control variables in this process because the W oxides are hydrogen-reduced via several reduction stages at high temperature over 80$0^{\circ}C$ with susceptive reduction conditions. In this experiment, the W-15 wt%Cu nanocomposite powder was fabricated with the ball-milling and hydrogen-reduction process using W and CuO powder. The microstructure of the fabricated W-Cu nanocomposite powder was homogeneously composed of the fine W particles embedded in the Cu matrix. In the sintering process, the solid state sintering was certainly observed around 85$0^{\circ}C$ at the heating rate of 1$0^{\circ}C$/min. It is considered that the solid state sintering at low temperature range should occur as a result of the sintering of Cu phase between aggregates. The specimen was fully densified over 98% for theoretical density at 120$0^{\circ}C$ for 1 h with the heating rate of 1$0^{\circ}C$/min.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.252-255
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• 2004

반도체는 high integrated, high speed, low power를 위하여 design 뿐만 아니라 재료 측면에서도 많은 변화를 가져오고 있으며, RC delay time을 줄이기 위하여 Al 배선보다 비저항이 낮은 Cu와 low-k material 적용이 그 대표적인 예이다. 그러나, Cu 배선의 경우 dry etching이 어려우므로, 기존의 공정으로는 그 한계를 가지므로 damascene 또는 dual damascene 공정이 소개, 적용되고 있다. Damascene 공정은 절연막에 photo와 RIE 공정을 이용하여 trench를 형성시킨 후 electrochemical plating 공정을 이용하여 trench에 Cu를 filling 시킨다. 이후 CMP 공정을 이용하여 절연막 위의 Cu와 barrier material을 제거함으로서 Cu 배선을 형성하게 된다. Dual damascene 공정은 trench와 via를 동시에 형성시키는 기술로 현재 대부분의 Cu 배선 공정에 적용되고 있다. Cu CMP는 기존의 metal CMP와 마찬가지로 oxidizer를 이용한 Cu film의 화학반응과 연마 입자의 기계가공이 기본 메커니즘이다. Cu CMP에서 backside pressure 영향이 uniformity에 미치는 영향을 살펴보았으며, electrochemical plating 공정에서 발생하는 hump가 CMP 결과에 미치는 영향과 dishing 결과를 통하여 그 영향을 평가하였다.

• Journal of Electrochemical Science and Technology
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• v.10 no.3
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• pp.329-334
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• 2019

Sn-Cu alloy powders were prepared via a simple chemical reduction method for the negative electrode materials in lithiumion batteries. The addition of Cu can suppress the growth of Sn particles during synthetic process. Furthermore, the Cu also acts as a matrix phase against the volume change during cycling. With increasing amount of the Cu, a stable $Cu_6Sn_5$ phase formed in the Sn-Cu alloy and its cycle performance greatly enhanced depending on the Cu content. To promote the generation of the $Cu_6Sn_5$ phase, the synthesis temperature is raised to $60-100^{\circ}C$ from the ambient temperature. The Sn-Cu alloy powders prepared at elevated temperatures showed remarkable cycle performances. The Sn-Cu alloy powder obtained at $60^{\circ}C$ exhibited a significantly high volumetric capacity of over 2,000 mAh/cc at the 50th cycle.

• Journal of Electrochemical Science and Technology
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• v.11 no.1
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• pp.60-67
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• 2020

In this study, copper (II) oxide powder for electroplating was prepared by recovering CuCl₂ from NaClO₃ type etching wastes via recovered non-sintering two step chemical reaction. In case of alkali copper carbonate [mCuCo₃·nCu(OH)₂], first reaction product, CuCo₃ is produced more than Cu(OH)₂ when the reaction molar ratio of sodium carbonate is low, since m is larger than n. As the reaction molar ratio of sodium carbonate increased, m is larger than n and Cu(OH)₂ was produced more than CuCO₃. In the case of m has same values as n, the optimum reaction mole ratio was 1.44 at the reaction temperature of 80℃ based on the theoretical copper content of 57.5 wt. %. The optimum amount of sodium hydroxide was 120 g at 80℃ for production of copper (II) oxide prepared by using basic copper carbonate product of first reaction. At this time, the yield of copper (II) oxide was 96.6 wt.%. Also, the chloride ion concentration was 9.7 mg/L. The properties of produced copper (II) oxide such as mean particle size, dissolution time for sulfuric acid, and repose angle were 19.5 mm, 64 second, and 34.8°, respectively. As a result of the hole filling test, it was found that the copper oxide (II) prepared with 120 g of sodium hydroxide, the optimum amount of basic hydroxide for copper carbonate, has a hole filling of 11.0 mm, which satisfies the general hole filling management range of 15 mm or less.

• Journal of the Korean Chemical Society
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• v.32 no.2
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• pp.122-129
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• 1988

The rates of aquation of sparteine cobalt(II) halide and sparteine copper(II) halide were investigated in the citrate buffer solutions. The aquation of cobalt(II) complexes proceeds via D-mechanism and the catalytic effect of halide ions is not observed. The aquation of copper(II) complexes proceeds via $I_d$-mechanism and is catalyzed by the presence of cyanide and halide ions, and the aquation rate is pH dependent. The different mechanistic behavior of cobalt(II) complexes from corresponding copper(II) complexes seems to be attributed to the weakness of Co-N bond in the coordination sphere.

• Journal of Pharmaceutical Investigation
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• v.36 no.6
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• pp.371-375
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• 2006

Neomycin coupled to a polymer matrix via a metal linker was prepared and evaluated for prolonging antibacterial activity. Microcrystallized cellulose was chemically modified to cellulose xanthate(MCX) to afford metal binding sites. MCX was treated with Cu(II), Fe(III) or Zn(II) followed by reaction with neomycin (Ne). The release of Ne from MCX-Zn(II)-Ne was investigated and its activity duration was measured by ditch plate method. The amount of metal bound to MCX was 0.36 mmol/g matrix, 0.26 mmol/g matrix and 0.56 mmol/g matrix for Cu(II), Zn(II) and Fe(III), respectively. Ne bound to MCX-metal chelates was 0.006 mmol, 0.07 mmol and 0.01 mmol per g MCX for Cu(II), Zn(II) and Fe(III), respectively. The Ne release from MCX-Zn(II)-Ne was sustained even after seven washes, whereas Ne from MC/Zn(II)/Ne mixture was almost completely released in two washes. Antibacterial activity was prolonged with MCX-Zn(II)-Ne and MCX-Fe(III)-Ne, but not with MCX-Cu(II)-Ne when compared with that of free Ne. Taken together, these results suggest that neomycin coupled to MCX via a proper metal linker has a potential as a polymeric antibacterial agent with sustained activity.

• Bulletin of the Korean Chemical Society
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• v.34 no.3
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• pp.777-782
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• 2013

In order to further reduce the sulfur content in liquid hydrocarbon fuels, a desulfurization process by adsorption for removing dimethyl sulfide (DMS) and propylmercaptan (PM) was investigated. Bentonite adsorbents modified by $CuCl_2$ for the desulfurization of model oil was investigated. The results indicated that the modified bentonite adsorbents were effective for adsorption of DMS and PM. The bentonite adsorbents were characterized by X-ray diffraction (XRD) and thermal analysis (TGA). The acidity was measured by FT-IR spectroscopy. Several factors that influence the desulfurization capability, including loading and calcination temperature, were studied. The maximum sulfur adsorption capacity was obtained at a Cu(II) loading of 15 wt %, and the optimum calcination temperature was $150^{\circ}C$. Spectral shifts of the ${\nu}$(C-S) and ${\nu}$(Cu-S) vibrations of the complex compound obtained by the reaction of $CuCl_2$ and DMS were measured with the Raman spectrum. On the basis of complex adsorption reaction and hybrid orbital theory, the adsorption on modified bentonite occurred via multilayer intermolecular forces and S-M (${\sigma}$) bonds.

• Korean Journal of Materials Research
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• v.27 no.4
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• pp.221-228
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• 2017

Various morphologies of copper oxide (CuO) have been considered to be of both fundamental and practical importance in the field of electronic materials. In this study, using Cu ($0.1{\mu}m$ and $7{\mu}m$) particles, flake-type CuO particles were grown via a wet oxidation method for 5min and 60min at $75^{\circ}C$. Using the prepared CuO, AlN, and silicone base as reagents, thermal interface material (TIM) compounds were synthesized using a high speed paste mixer. The properties of the thermal compounds prepared using the CuO particles were observed by thermal conductivity and breakdown voltage measurement. Most importantly, the volume of thermal compounds created using CuO particles grown from $0.1{\mu}m$ Cu particles increased by 192.5 % and 125 % depending on the growth time. The composition of CuO was confirmed by X-ray diffraction (XRD) analysis; cross sections of the grown CuO particles were observed using focused ion beam (FIB), field emission scanning electron microscopy (FE-SEM), and energy dispersive analysis by X-ray (EDAX). In addition, the thermal compound dispersion of the Cu and Al elements were observed by X-ray elemental mapping.