• Journal of the Korean Vacuum Society
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• v.9 no.3
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• pp.267-272
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• 2000

Electroplating Cu was deposited on Si(100) wafer after seed Cu was deposited by sputtering first. TaN was deposited as a diffusion barrier before depositing the seed Cu. Electroplating Cu thin films show highly (111)-oriented microstructure for both before and after annealing at $450^{\circ}C$ for 30min and no copper silicide was detected in the same samples, which indicates that TaN barrier layer blocks well the Cu diffusion into silicon substrate. After annealing the electroplating Cu film up to $450^{\circ}C$, the Cu film became columnar from non-columnar, its grain size became larger about two times, and also defects density of stacking faults, twins and dislocations decreased greatly. Thus the heat treatment will improve significantly electromigration property caused by the grain boundary in the Cu thin films.

• Korean Journal of Metals and Materials
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• v.50 no.6
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• pp.419-425
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• 2012

The purpose of this research was to develop a low Ni austenitic cast iron through replacing Ni by Cu and Mn because they are cheaper than Ni. The effect of the Cu content (6-12 wt%) on the microstructure characteristics was investigated in Fe-3%C-16%(Ni+Cu+Mn) cast iron. Contrary to general effect of the Cu on cast iron, the result of the microstructure analysis indicated that bainite and cementite were formed in high Cu content (>8 wt%Cu). A crystallized Cu-solution (Cu-Mn) phase and MnS in the Cu-solution were formed. The quantity of those phases increased as the Cu content increased. Consequently, the high Cu content in the composition ratio (Ni+Cu+Mn=16%) caused the formation of Cu-Mn/MnS and those phases decreased the effect of Cu and Mn on austenite formation. For this reason, bainite and cementite were formed in high Cu content.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.8
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• pp.1154-1161
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• 2000

Two experiments were conducted to evaluate the efficacy of cupric citrate (Cu-citrate) relative to cupric sulfate $(CuSO_4)$ as a Cu source for weanling and grow-finish pigs. In addition, the use of liver and bile Cu concentrations as indices of the bioavailability of Cu sources was investigated. Experiment one consisted of a nursery phase (35 d; initial BW=6.4 kg, final BW=21.4 kg) followed by a grow-finish phase (103 d; initial BW=21.5 kg, final BW=111.7 kg). Experiment two only consisted of a nursery phase (35 d; initial BW=6.3 kg, final BW=18.6 kg). Dietary treatments were identical for both experiments and consisted of: control (10 ppm $CuSO_4$); control+66 or 225 ppm $CuSO_4$; control+33, 66, or 100 ppm Cu-citrate. An antibiotic was included in diets for Exp. 1 but not Exp. 2. In both experiments, growth performance variables were similar for pigs receiving Cu-citrate and $CuSO_4$; however, growth performance was not improved by high concentrations of $CuSO_4$. Liver and bile Cu were increased (p<0.05) by 225 ppm $CuSO_4$; however, lower dietary concentrations of Cu from either $CuSO_4$ or Cu-citrate did not affect the Cu concentration of liver or bile relative to that observed in the control pigs. Irrespective of Cu source, there was no linear (p>0.10) increase in plasma Cu with increasing Cu concentrations in the diet for both experiments. However, the plasma Cu concentrations were highest (p<0.10) in pigs receiving diets supplemented with 225 ppm $CuSO_4$. Sixteen randomly chosen pigs per treatment in Exp. 1 were continued through the grow-finish phase. Body weight gain and feed intake were improved (p<0.10) by 66 ppm $CuSO_4$, but other dietary Cu treatments did not alter pig performance compared to the control diet. Plasma Cu concentrations were increased (p<0.10) by 225 ppm $CuSO_4$ in the growing phase and by 225 ppm $CuSO_4$ and 100 ppm Cu-citrate in the finishing phase. These data reveal no consistent effect of $CuSO_4$ on performance; therefore, it is difficult to assess the efficacy of these two Cu sources. In addition, these studies demonstrate that liver and bile Cu are not good indicators of Cu bioavailability in pigs fed adequate to pharmacological concentrations of Cu.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.8
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• pp.1131-1136
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• 2003

Forty-eight individually fed Angus steers (body weight $220kg{\pm}9.1$) were utilized to investigate the effects of copper (Cu) source and concentration on lipid metabolism and carcass quality. Steers were stratified by body weight and initial liver Cu concentration and randomly assigned to one of five groups. Groups were then randomly assigned to treatments. Treatments consisted of: 1) control (no supplemental Cu); 2) 10 mg Cu/kg DM from $CuSO_4$; 3) 10 mg Cu/kg DM from a Cu amino acid complex (Availa Cu) 4) 20 mg Cu/kg DM from $CuSO_4$; and 5) 20 mg Cu/kg DM from Availa Cu. Steers were fed a corn-alfalfa-based growing diet for 56 d. Steers were then switched to a high concentrate finishing diet for 145 d. On day 74 of the finishing phase subcutaneous adipose tissue biopsies were obtained from three steers/treatment to determine basal and stimulated lipolytic rates in vitro. Steers were then slaughtered after receiving the finishing diet for 145 d. Control steers tended (p<0.12) to have lower ceruloplasmin (Cp) activity than Cu supplemented steers. Steers receiving 20 mg Cu/kg DM from Availa Cu had higher (p<0.03) Cp activity than steers receiving 20 mg Cu/kg DM from $CuSO_4$. Plasma non-esterified fatty acids were similar across treatments. Steers receiving 10 mg Cu/kg DM from Availa Cu had higher (p<0.02) total plasma cholesterol concentrations relative to steers receiving 10 mg Cu/kg DM from $CuSO_4$. Steers receiving 20 mg Cu/kg DM from Availa Cu had lower (p<0.03) plasma triglyceride concentrations than steers supplemented with 20 mg Cu/kg DM from $CuSO_4$. Fatty acid profile of longissimus muscle was similar across treatments. Backfat depth tended (p<0.18) to be lower in Cu supplemented steers relative to controls. Steers supplemented with 20 mg Cu/kg DM from Availa Cu had heavier (p<0.03) hot carcass weights and a greater (p<0.02) dressing percentage than steers supplemented with 20 mg Cu/kg DM from $CuSO_4$. Furthermore, in vitro basal (p<0.06) and epinephrine stimulated (p<0.04) lipolytic rates of subcutaneous adipose tissue were higher in Cu supplemented steers relative to controls. The results of this study suggest that Cu supplementation has minimal effects on blood and lean tissue lipid profile. However, it appears that Cu may play a role in lipid metabolism in subcutaneous adipose tissue.

• Bulletin of the Korean Chemical Society
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• v.10 no.6
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• pp.504-509
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• 1989

The effect of oxygen-deficiency on the charge distributions and orbital energies for small copper oxide clusters representing the superconducting materials $YBa_2Cu_3O_x (6{\leq}x{\leq}7)$ were investigated by the extended Huckel molecular orbital (EHMO) method with the tight-binding model. Our calculations show +3 oxidation state of Cu(1) in the $CuO_3$ chain and +2 or +1 of Cu(2) in the $CuO_2$ layers for $YBa_2Cu_3O_7$ with the nominal charge of $Cu_3$ = +7 (or +5), while for $YBa_2Cu_3O_6$ +1 oxidation state of Cu(1) and +3 (or +2) of Cu(2) in the $CuO_2$ layers with the nominal charge of $Cu_3$ = +7 (or +5). For $Cu_3O_{12}$ cluster representing $YBa_2Cu_3O_7$ with the nominal charge of $Cu_3$ = +7 the Cu(2) $d_{{x^2}-{y^2}}$ orbitals in the $CuO_2$ layers is a typical Jahn-Teller $d^9$ system with the partial hole and the Cu(1) $d_{{_z2}-{_y2}}$ orbital in the $CuO_3$ chain contains hole occupancy. For $Cu_3O_{10}$ cluster representing $YBa_2Cu_3O_6$ with the nominal charge of Cu = +5 the orbital character of the highest partially occupied MO (HPOMO) and the lowest completely unoccupied MO (LCUMO) of $Cu_3O_{12}$ representing $YBa_2Cu_3O_7$ with the nominal charge of $Cu_3$ = +7 is reversed, and the character of Cu(1) $d{{x^2}-{y^2}}$ orbital of LCUMO of the $Cu_3O_{12} $cluster is vanished. It is suggested that the local crystal field environment of Cu(1) by the oxygens in the Cu(1) chain may play a vital role in conductivity and superconductivity, either alone or through cooperative electronic coupling with the Cu(2) layers in $YBa_2Cu_3O_7.$.

• Korean Journal of Materials Research
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• v.5 no.6
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• pp.657-666
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• 1995

Chemical vapor deposition of copper from the Cu(hfac)$_2$, Cu(II) hexafluoroacetylacetonate precursor, has been thermodynamically investigated by the minimization of Gibbs free energy of the system. For the Cu(hfac)$_2$-Ar system, carbon incorporation into the deposited films was observed in all the process conditions, which is presumably inherent from the thermal decomposition of the Cu(hfac)$_2$, precursor. For the Cu(hfac)$_2$-H$_2$system, lower temperatures were required than those of the Cu(hfac)$_2$-Ar system for the depositon of the copper films. Furthermore, we identified that the appearances of the condensed phases were sequentially changed from the codeposits of C(s)+CuF(s) to C(s)+CuF(s)+Cu(s), C(s)+Cu(s), Cu(s), and C(s), when the H$_2$input ratio and th reaction temperature were increased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.5
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• pp.1124-1130
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• 1999

The purpose of this study was to investigate the effect of copper supplementation on mineral utilizations in rats. Intakes, excretions, and tissue levels of Fe, Zn, Cu, Ca, Mg, Na, K were compared in rats fed diet with 100, 200, 400% of copper requirement(1Cu, 2Cu and 4Cu, respectively) for 6 weeks. The feed intake was significantly higher in 2Cu compared to 1Cu group, however, body weight gain was not significantly different among the three groups. While the serum level of Fe was significantly decreased, that of Cu was significantly elevated by Cu supplementation. The liver and kidney levels of Mg and Na, intakes of all the minerals, urinary excretions of Fe, Cu, Ca and Mg were significantly higher in 2Cu and/or 4Cu compared to 1Cu. The fecal excretions, retentions and absorptions of all the minerals were not affected by Cu supple mentation. In summary, these results suggest that dietary Cu supplementation has no effect on mineral utilizations, but effect on distribution in tissues of rats.

• Journal of the Korean Chemical Society
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• v.50 no.1
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• pp.60-64
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• 2006

has been synthesized using the layered organic-inorganic hybrids, Cu2(OH)3(CH3COO)·H2O as a precursor. Cubic Cu2O is synthesized by reducing Cu2(OH)3(CH3COO)·H2O with glucose in water at 75oC. The effects of precursor and glucose are investigated. The structure of Cu2(OH)3(CH3COO)·H2O plays an important role in preparing the uniform size of Cu2O.

• Korean Journal of Materials Research
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• v.6 no.4
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• pp.412-420
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• 1996

상업용 자동차 축전지 극판재료로 각형의 초정 Pb 재료에 적은 부피 분율의 Cu상을 가지는 Pb-Cu 합금을 응고시킬 때 각형의 초정 Cu 수지상이 석출되었다. 중요한 응고변수인 냉각속도와 Cu조성의양에 따른 각형의 Cu상의 형태변화를 조사하기 위하여 Pb-1wt%Cu, pb-3wt%Cu, Pb-5wt%Cu, Pb-9wt%Cu, Pb-12wt%Cu, 등의 5가지 합금이 선택되어 노냉, 공냉, 금형냉, 수냉의 4가지 냉각방법을 이용하여 실험하였다. 일반적으로 냉각속도와 Cu성분이 증가함에 따라 Cu상의 각형정도가 감소하였으며 결국 가장 빠른 냉각인 수냉각시에는 수지상 형태가 정출되지 않고 구형의 형태가 정출 되었다.