• Progress in Superconductivity
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• v.13 no.1
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• pp.12-17
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• 2011

We investigated the effects of Ba and Cu co-substitution on the structural and superconducting properties of ($Ru_{1-y}Cu_y$)($Sr_{1.67-x}Ba_xEu_{0.33}$)($Eu_{1.34}Ce_{0.66}$)$Cu_2O_z$ samples. X-ray diffraction(XRD) reveals that single-phase samples can be obtained in the range from x = 0.1 to 0.2 for ($Ru_{0.5}Cu_{0.5}$)($Sr_{1.67-x}Ba_xEu_{0.33}$)($Eu_{1.34}Ce_{0.66}$)$Cu_2O_z$ and from y = 0.25 to 0.5 for ($Ru_{1-y}Cu_y$)($Sr_{1.47}Ba_{0.2}Eu_{0.33}$)($Eu_{1.34}Ce_{0.66}$)$Cu_2O_z$, respectively. All samples with compositions of ($Ru_{0.5}Cu_{0.5}$)($Sr_{1.67-x}Ba_xEu_{0.33}$) ($Eu_{1.34}Ce_{0.66}$)$Cu_2O_z$ (x = 0 - 0.33) show superconducting transition behavior and the onset transition temperature decreases slightly with increasing x in consistent with the change of hole concentration estimated from room temperature thermoelectric power measurements. The XRD and resistivity measurements for the ($Ru_{1-y}Cu_y$)($Sr_{1.47}Ba_{0.2}Eu_{0.33}$)($Eu_{1.34}Ce_{0.66}$) $Cu_2O_z$ system indicate that the partial substitution of Cu for Ru is necessary to form phase pure samples, but result in a small change in transition temperature in the single-phase region from x = 0.25 to 0.5.

• Carbon letters
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• v.5 no.4
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• pp.180-185
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• 2004

Thermolysis of $Cu(NO_3)_2{\cdot}3H_2O$ impregnated activated carbon fiber (ACF) was studied by means of XRD analysis to obtain Cu-impregnated ACF. $Cu(NO_3)_2{\cdot}3H_2O$ was converted into $Cu_2O$ around $230^{\circ}C$. The $Cu_2O$ was reduced to Cu at $400^{\circ}C$, resulting in ACF-C(Cu). Some Cu particles have a tendency to aggregate through the heat treatment, resulting in the ununiform distribution in ACF. Catalytic decomposition of NO gas has been performed by Cu-impregnated ACF in a column reactor at $400^{\circ}C$. Initial NO concentration was 1300 ppm diluted in helium gas. NO gas was effectively decomposed by 5~10 wt% Cu-impregnated ACF at $400^{\circ}C$. The concentration of NO was maintained less than 200 ppm for 6 hours in this system. The ACF-C(Cu) deoxidized NO to $N_2$ and was reduced to ACF-$C(Cu_2O)$ in the initial stage. The ACF-$C(Cu_2O)$ also deoxidized NO to $N_2$ and reduced to ACF-C(CuO). This ACF-C(CuO) was converted again into ACF-C(Cu) by heating. There was no consumption of ACF in mass during thermolysis and catalytic decomposition of NO to $N_2$ by copper. The catalytic decomposition was accelerated with increase of the reaction temperature.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.141-141
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• 2018

Copper is one of the most abundant metals on earth. Its oxide (CuO) is an intrinsically p-type metal-oxide semiconductor with a bandgap ($E_g$) of 1.2-2.0 eV 1. Copper oxide nanomaterials are considered as promising materials for a wide range of applications e.g., lithium ion batteries, dye-sensitized solar cells, photocatalytic hydrogen production, photodetectors, and biogas sensors 2-7. Recently, high-density and uniform CuO nanostructures have been grown on Cu foils in alkaline solutions 3. In 2011, T. Soejima et al. proposed a facile process for the oxidation synthesis of CuO nanobelt arrays using $NH_3-H_2O_2$ aqueous solution 8. In 2017, G. Kaur et al. synthesized CuO nanostructures by treating Cu foils in $NH_4OH$ at room temperature for different treatment times 9. The surface treatment of Cu in alkaline aqueous solutions is a potential method for the mass fabrication of CuO nanostructures with high uniformity and density. It is interesting to compare the gas sensing properties among CuO nanomaterials synthesized by this approach and by others. Nevertheless, none of above studies investigated the gas sensing properties of as-synthesized CuO nanomaterials. In this study, CuO nanowalls versus nanoparticles were synthesized via the oxidation process of Cu foil in NH4OH solution at $50-70^{\circ}C$. The gas sensing properties of the as-prepared CuO nanoplates were examined with $C_2H_5OH$, $CH_3COCH_3$, and $NH_3$ at $200-360^{\circ}C$.

• Nuclear Engineering and Technology
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• v.54 no.12
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• pp.4491-4498
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• 2022

The thermal stress between W plasma-facing material (PFM) and Cu heat sink in fusion reactors can be significantly reduced by using a W-Cu functionally graded material (W-Cu FGM) interlayer. However, there is still considerable stress at the joining interface between W and W-Cu FGM in the W/W-Cu FGM/Cu portions. In this work, we fabricate W skeletons with continuous gradients in porosity by a modified sedimentation method. Sintering densification behavior and pore characteristics of the sedimented W skeletons at different sintering temperatures were investigated. After Cu infiltration, the final W-Cu FGM was obtained. The results indicate that the pore size and porosity in the W skeleton decrease gradually with the increase of sintering temperature, but the increase of skeleton sintering temperature does not reduce the gradient range of composition distribution of the final prepared W-Cu FGM. And W-Cu FGM with composition distribution from pure W to W-20.5wt.% Cu layer across the section was successfully obtained. The thickness of the pure W layer is about one-fifth of the whole sample thickness. In addition, the prepared W-Cu FGM has a relative density of 94.5 % and thermal conductivity of 185 W/(m·K). The W-Cu FGM prepared in this work may provide a good solution to alleviate the thermal stress between W PFM and Cu heat sink in the fusion reactors.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.7
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• pp.965-973
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• 2014

Three studies were conducted to investigate whether a chelated Cu can replace $CuSO_4$ as a growth promoter in pigs. In Exp. 1, a total of 240 piglets (Large White${\times}$Landrace, $7.36{\pm}0.10kg$) were randomly allocated to 1 of 3 treatments with 8 replicates and 10 piglets per pen. Treatments included a NRC control ($CuSO_4$, 6 mg/kg), two Cu supplementations from either $CuSO_4$ or $Cu(HMTBa)_2$ at 170 mg/kg. Pigs fed $Cu(HMTBa)_2$ were 6.0% heavier than pigs fed either the NRC control or 170 mg/kg $CuSO_4$ (p = 0.03) at the end of the experiment. During the 42 days of experimental period, pigs fed $Cu(HMTBa)_2$ gained 9.0% more (p = 0.01), tended to eat more feed (p = 0.09), and had better feed efficiency (p = 0.06) than those fed $CuSO_4$. Compared with the 6 mg/kg $CuSO_4$ NRC control, liver Cu was increased 2.7 times with 170 mg/kg $CuSO_4$ supplementation, and was further increased with $Cu(HMTBa)_2$ (4.5 times, p<0.05). In Exp. 2, a total of 616 crossbred piglets (PIC, $5.01{\pm}0.25kg$) were randomly allocated to 1 of 4 treatments with 7 replicates and 22 piglets per pen. Treatments included a NRC control (from $CuSO_4$), and three pharmaceutical levels of Cu (150 mg/kg) supplemented either from C$CuSO_4$, tri-basic copper chloride ($Cu_2[OH]_3C1$), or $Cu(HMTBa)_2$. Pigs fed $CuSO_4$ or $Cu(HMTBa)_2$ had better feed efficiency (p = 0.01) and tended to gain more (p = 0.08) compared with those fed the NRC control. Pigs fed $Cu_2[OH]_2C1$ were intermediate. Pigs fed $Cu(HMTBa)_2$ had the highest liver Cu, which was significantly higher than those fed ($Cu_2[OH]_3C1$) or the negative control (p = 0.01). In Exp. 3, a total of 1,048 pigs (PIC, $32.36{\pm}0.29kg$) were allotted to 6 treatments with 8 replicates per treatment and 20 to 22 pigs per pen. The treatments included a NRC control with 4 mg/kg Cu from $CuSO_4$, a positive control with 160 mg/kg Cu from $CuSO_4$, and incremental levels of $Cu(HMTBa)_2$ at 20, 40, 80, and 160 mg/kg. During the overall experimental period of 100 days, no benefit from 160 mg/kg $CuSO_4$ was observed. Pigs fed $Cu(HMTBa)_2$ had increased ADG (linear and quadratic, $p{\leq}0.05$) and feed efficiency (linear and quadratic, $p{\leq}0.05$) up to 80 mg/kg and no further improvement was observed at 160 mg/kg for the whole experimental period. Pigs fed 80 mg/kg $Cu(HMTBa)_2$ weighed 1.8 kg more (p = 0.07) and were 2.3 kg heavier in carcass (p<0.01) compared with pigs fed 160 mg/kg $CuSO_4$. In addition, loin depth was increased with increased $Cu(HMTBa)_2$ supplementation with pigs fed 80 mg/kg $Cu(HMTBa)_2$ had the greatest loin depth (p<0.05). In summary, $Cu(HMTBa)_2$ can be used to replace high $CuSO_4$ as a growth promoter in nursery and grower-finisher pigs.

• Journal of Nutrition and Health
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• v.39 no.4
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• pp.381-391
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• 2006

This study is performed to compare the dietary intakes and food sources of copper (Cu) using the database of Cu content developed in this study between the elementary schoolchildren in remote rural areas (RA, n=58, $9.9{\pm}1.7$ yrs) and those in urban area (UA, n=60, $9.4{\pm}1.8$ yrs), and to analyze the relationship between serum Cu concentration and serum antioxidant status in the RA. The results obtained in this study were as followings: 1) Dietary intakes of calorie, calcium and iron in the RA were in the 3/5-4/5 of the Korean RDA while the UA were similar to or more than the Korean RDA, 7th ed. except iron. 2) More than 273 kinds of food consumed by the subjects were analyzed the content of Cu and database of Cu content were developed in the present study. The mean dietary intake of Cu per day in the RA was $0.99{\pm}0.07mg/d$ ($170.0{\pm}13.2%$ of the USA RDA) while it was $1.22{\pm}0.07mg/d$ ($203.4{\pm}13.1%$ of the RDA) in the UA. The percentage of dietary intakes of Cu less than 213 of the RDA was 8.6% in the RA in comparison to 0% in the UA. 3) The RA and the UA consumed more than 80% of total dietary intakes of Cu from plant foods. Thus, the RA and the UA consumed Cu from cooked rice, vegetables and fruits as a major source. However the RA had less Cu from meat and their products than did the UA (p<0.05) .4) Crab stew including crab and juice was the highest food source of Cu for the total subjects, followed by seasoned bud of aralia, cooked; beef rib meat, roasted; soybean paste soup w/mallow; and soybean paste soup w/mallow & beef. Major food source of Cu was similar for the RA and the UA such as cooked rice, vegetables and fruits. 5) Mean concentration of serum Cu in the RA was $18.1{\pm}0.7{\mu}M/L$ that was in the normal value, and all subjects in this group were in more than normal value. In the RA serum Cu concentration related positively with serum ceruloplasmin concentration, serum vitamin C concentration and EC SOD activity, respectively. However, serum Cu concentration did not relate with serum TBARS concentration in the RA. Above results showed that the RA had good status of Cu nutrition based upon dietary intake and serum concentration, however some of the RA had lower intake of Cu than the RDA. The overall children in the UA had good Cu nutrition. Therefore, the subgroup of the RA should be supported to improve their Cu nutrition, and this support could give them better antioxidant status based upon positive relationship between serum Cu concentration and serum antioxidant status in the RA.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.2
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• pp.63-68
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• 1987

The effects of various levels of copper(Cu) intake on the concentrations of copper, iron (Fe) and 3inc(Zn) in rat tissues were studied in growing rats. For different groups the drinking water was supplemented with 0(control), 25, 50, 100 and 200ppm Cu(as copper sulphate) for 1 day respectively. All animal groups were fed with the control diet (Cu contents, 12.8%mg/kg diet) during the experiment. At the end of the 4 week experiment, body weight gain was slightly lower in the Cu supply groups than in control group. Liver and serum Cu were significantly higher in 50, 100 and 200ppm Cu of male and in 200ppm Cu of female than in control groups. Spleen Cu was significantly increased by the supplementation of Cu. Liver and heart Fe of male and heart Fe of female were increased by incresing supplementary Cu levels. In 50ppm Cu group, liver, spleen and kidney Fe of female increased but the others did not. Fe of tissues was different in male and female rats according to Cu levels supplied. Serum Zn of male and female was significantly lower in 50, 100 and 200ppm Cu groups than in control and 25ppm Cu groups. When supplemented with Cu levels there were no significant differences among groups for liver, kidney, spleen and heart Zn as well as heart and kidney Cu.

• Mass Spectrometry Letters
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• v.14 no.4
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• pp.153-159
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• 2023

The copper ion, Cu(II), binding sites for amyloid fragment Aβ1-16 (=Aβ16 ) were investigated to explain the biological activity difference in the Aβ16 aggregation process. The [M+Cu+(z-2)H]^z+ (z = 2, 3 and 4, M = Aβ16 monomer) and [D+Cu+(z-2)H]^z+ (z = 3 and 5, D = Aβ16 dimer) structures were investigated using electrospray ionization (ESI) mass spectrometry (MS) and tandem mass spectrometry (MS/MS). Fragment ions of the [M+Cu+(z-2)H]^z+ and [D+Cu+(z-2)H]^z+ complexes were observed using collision-induced dissociation MS/MS. Three different fragmentation patterns (fragment "a", "b", and "y" ion series) were observed in the MS/MS spectrum of the (Aβ16 monomer or dimer-Cu) complex, with the "b" and "y" ion series regularly observed. The "a" ion series was not observed in the MS/MS spectrum of the [M+Cu+2H]⁴⁺ complex. In the non-covalent bond dissociation process, the [D+Cu+3H]⁵⁺ complex separated into three components ([M+Cu+H]³⁺, M³⁺, and M²⁺), and the [M+Cu]²⁺ subunit was not observed. The {M + fragment ion of [M+Cu+H]³⁺} fragmentation pattern was observed during the covalent bond dissociation of the [D+Cu +3H]⁵⁺ complex. The {M + [M+Cu+H]³⁺} complex geometry was assumed to be stable in the [D+Cu+3H]⁵⁺ complex. The {M + fragment ion of [M+Cu]²⁺} fragmentation pattern was also observed in the MS/MS spectrum of the [D+Cu+H]³⁺ complex. The {M + [y₉+Cu]¹⁺} fragment ion was the characteristic fragment ion. The [D+Cu+H]³⁺ and [D+Cu+3H]⁵⁺ complexes were likely to form a monomer-monomer-Cu (M-M-Cu) structure instead of a monomer-Cu-monomer (M-Cu-M) structure.

• Journal of the Microelectronics and Packaging Society
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• v.15 no.4
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• pp.17-24
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• 2008

Thermal annealing and electromigration test were performed at $150^{\circ}C$ and $150^{\circ}C,\;5{\times}10^4\;A/cm^2$ conditions, respectively, in order to compare the growth kinetics of intermetallic compound(IMC) in Cu pillar bump. The quantitative interfacial adhesion energy with annealing was measured by using four-point bending strength test in order to assess the effect of IMC growth on the mechanical reliability of Cu pillar bump. Only $Cu_6Sn_5$ was observed in the Cu pillar/Sn interface after reflow. However, $Cu_3Sn$ formed and grew at Cu pillar/$Cu_6Sn_5$ interface with increasing annealing and stressing time. The growth kinetics of total($Cu_6Sn_5+Cu_3Sn$) IMC changed when all Sn phases in Cu pillar bump were exhausted. The complete consumption time of Sn phase in electromigration condition was faster than that in annealing condition. The quantitative interfacial adhesion energy after 24h at $180^{\circ}C$ was $0.28J/m^2$ while it was $3.37J/m^2$ before annealing. Therefore, the growth of IMC seem to strongly affect the mechanical reliability of Cu pillar bump.

• Journal of Powder Materials
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• v.8 no.4
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• pp.245-252
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• 2001

Recent remarkable progress in the semiconductor industry has promoted smaller size of semiconductor chips and increased amounts of heat generation. So, the demand for a substrate material to meet both the characteristics of thermal expansion coefficient and heat radiation has been on the increase. Under such conditions, tungsten(W)-copper(Cu) has been proposed as materials to meet both of the above characteristics. In the present study, the W-10wt.%Cu powders were synthesised by the mixing and hydrogen reduction of the starting mixture materials such as W-Cu, $W-CuCl_2$and $WO_3-CuCl_2$ in order to obtain the full densification. The W-10wt.%Cu produced by hydrogen reduction showed the higher interparticle friction than the simple mixed W-10wt%Cu because of the W agglomerates. In the dilatometric analysis the W-10wt.%Cu prepared from the $W-CuCl_2$was largely shrank by heating up $1400^{\circ}C$ at the constant heating rate of $5^{\circ}C$/min. The possibility of application of metal injection molding (MIM) was also investigated for mass production of the complex shaped W-Cu parts in semiconductor devices. The relationship between the temperature of molding die and the pressure of injection molding was analyzed and the heating up stage of 120-$290^{\circ}C$ in the debinding process was controlled for the most suitable MIM condition.