• Journal of the Korean Magnetics Society
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• v.4 no.1
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• pp.44-47
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• 1994

High $T_{c}$ superconducting $Y_{1}Ba_{2}Cu_{3}O_{7-\delta}$ thin film was grown up for c-axis orientation by epitaxial growth method on $LaAlO_{3}$ single crystal substrate. The crystal structures of this thin film were found to be c-axis orientation by X-ray diffraction patterns. Hall effect and resistivity measurements were made by van der Pauw method. Hall resistivity was calculated from the magnetoresistivity by considering thermomagnetic effect. The relation was $pH=p_{s}tan{\alpha}_{n}-QBT\frac{S_s}{K_s}$ The measured Hall resistivity and the calculated one are in good agreement each other.

• Current Photovoltaic Research
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• v.8 no.2
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• pp.60-65
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• 2020

In perovskite solar cells with planar heterojunction configuration, selection of proper charge-transporting layers is very important to achieve stable and efficient device. Here, we developed solution processible Cu doped NiO_x (Cu:NiO_x) thin film as a hole-transporting layer (HTL) in p-i-n structured methylammonium lead trihalide (MAPbI₃) perovskite solar cell. The transmittance and thickness of NiO_x HTL is optimized by control the spin-coating rate and Cu is additionally doped to improve the surface morphology of undoped NiO_x thin film and hole-extraction properties. Consequently, a perovskite solar cell containing Cu:NiO_x HTL with optimal doping ratio of Cu exhibits a power conversion efficiency of 14.6%.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1114-1115
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• 2006

The preparation of single-phase $CuLaO_2$ with delafossite-type structure by means of the solid-state reaction method was investigated using X-ray diffraction. The results showed that notwhistanding the fact that there was a trace of metallic copper, nearly single-phase $CuLaO_2$ was obtained by using $La(OH)_3$ as a lanthanum source and by firing the mixed powder with nonstoichiometric composition ratio of $La(OH)_3:Cu_2O=1:1.425$ in a vacuum at 1273 K for 10 h. The measurement of electrical conductivity and Seebeck coefficient showed that $CuLaO_2$ thus obtained was a p-type semiconductor and had a Seebeck coefficient of approximately $70{\mu}V/K$.

• Applied Chemistry for Engineering
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• v.7 no.2
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• pp.261-268
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• 1996

Various $Cu/SiO_2$ catalysts with copper concentration ranging from 0 to 50wt% were prepared by kneading method for the steam reforming of methanol. These catalysts were calcined at temperatures in the range of $400^{\circ}C{\sim}900^{\circ}C$ and then reduced in a $H_2$ atmosphere in the range of $150^{\circ}C{\sim}350^{\circ}C$. Steam reforming of methanol was carried out at atmospheric pressure over a temperature range of $200^{\circ}C{\sim}400^{\circ}C$, steam/methanol molar ratio of 0.4~1.6 and W/F of 3~25 g.-cat.hr./mol. Characterization of the catalysts was studied using IR, BET and XRD. Using copper nitrate as a precursor for catalysts, pH in the preparation of catalysts had a great effect on the catalytic activity, but pH in the preparation of catalysts, calcination temperature, and reducing temperature in $H_2$ atmosphere had no effect on the product distribution. Optimum copper concentration, calcination temperature and reducing temperature were 40wt%, $700^{\circ}C$ and $300^{\circ}C$, respective)y. Reaction temperature for maximum $H_2$ production was $275^{\circ}C$, and the formation of methane which lowered quantity and quality of $H_2$ would be inhibited below $275^{\circ}C$. $Cu^{\circ}-Cu_2O$ might be active species in $Cu/SiO_2$ catalyst.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.2
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• pp.116-120
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• 2011

The 0.98 ($Na_{0.44}K_{0.52})Nb_{0.84}O_3-0.02Li_{0.04}$ ($Sb_{0.06}Ta_{0.1})O_3-0.5$ mol%CuO ceramics have been fabircated by ordinary sintering technique and the effect of various calcination method on the electrical propertis and microstructure have been studied. It was observed that the various calcination method influenced the elelctrical properties and structural properties of the 0.98NKN-0.02LST-0.5 mol%CuO ceramics with the optimum piezoelectric constant ($d_{33}$) and electromechanical coupling factor ($k_p$) at room temperature of about $155{\rho}C/N$ and 0.349, respectively, from 0.98NKN-0.02LST-0.5 mol%CuO ceramics sample. The curie temperature ($T_c$) of this ceramic was found at $440^{\circ}C$. The 0.98NKN-0.02LST-0.5 mol%CuO ceramics are a promising lead-free piezoelectric ceramics.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.9
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• pp.1279-1287
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• 2009

Concentrated livestock production has led to soil nutrient accumulation concerns. To reduce the environmental impact, it is necessary to understand current recommended livestock feeding practices. Two experiments were conducted to compare the effects of trace mineral supplementation on performance, carcass composition, and fecal mineral excretion of phase-fed, grow-finish pigs. Crossbred pigs (Experiment 1 (Exp. 1), (n = 528); Experiment 2 (Exp. 2), (n = 560)) were housed in totally-slatted, confinement barns, blocked by weight, penned by sex, and randomly assigned to pens at approximately 18 kg BW. Treatments were allocated in a randomized complete block design (12 replicate pens per treatment) with 9 to 12 pigs per pen throughout the grow-finish period. In Exp. 1, the control diet (Io100) contained Cu as $CuSO_{4}$, Fe as $FeSO_{4}$, and Zn (of which 25% was ZnO and 75% was $ZnO_{4}$) at concentrations of 63 and 378 mg/kg, respectively. Treatment 2 (O100) contained supplemental Cu, Fe, and Zn from organic sources (Bioplex, Alltech Inc., Nicholasville, KY) at concentrations of 19, 131, and 91 mg/kg, respectively, which are the commercially recommended dietary inclusion levels for these organic trace minerals. Organic Cu, Fe, and Zn concentrations from O100 were reduced by 25% and 50% to form treatments 3 (O75) and 4 (O50-1), respectively. In Exp. 2, treatment 5 (Io25) contained 25% of the Cu, Fe, and Zn (inorganic sources) concentrations found in Io100. Treatment 6 (O50-2) was identical to the O50-1 diet from Exp. 1. Treatment 7 (O25) contained the experimental microminerals reduced by 75% from concentrations found in O100. Treatment 8 (O0) contained no trace mineral supplementation and served as a negative control for Exp. 2. In Exp. 1, tenth-rib backfat, loin muscle area and ADG did not differ (p>0.05) between treatments. Pigs fed the control diet (Io100) consumed less feed (p<0.01) compared to pigs fed diets containing organic trace minerals, thus, G:F was greater (p = 0.03). In Exp. 2, there were no differences among treatment means for loin muscle area, but pigs fed the reduced organic trace mineral diets consumed less (p<0.05) feed and tended (p = 0.10) to have less tenth-rib backfat compared to pigs fed the reduced inorganic trace mineral diet. Considering that performance and feed intake of pigs was not affected by lower dietary trace mineral inclusion, mineral excretion could be reduced during the grow-finish phase by reducing dietary trace mineral concentration.

• Korean Journal of Materials Research
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• v.5 no.5
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• pp.583-597
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• 1995

We investigated the effect of the oxygne partial pressure on the phase stability of B $i_{2}$S $r_{2}$Ca C $u_{2}$ $O_{8+x}$ and B $i_{2}$S $r_{2}$C $a_{2}$C $u_{3}$ $O_{10+x}$ at 82$0^{\circ}C$. As the oxygen pressure decreased, B $i_{2}$Sr/sb 2/CaC $u_{2}$ $O_{8+x}$ melted at 2.2$\times$10$^{-3}$ atm $O_{2}$. In the case of the B $i_{1.7}$P $b_{0.4}$S $r_{2}$C $a_{2}$ $O_{10+x}$, it started to decompose into theree phases of B $i_{2}$S $r_{2}$Cu $O_{6+y}$, $Ca_{2}$Cu $O_{3}$ and C $u_{4}$ $O_{3}$ and C $u_{4}$ $O_{3}$ at 8.0$\times$10$^{-3}$ atm $O_{2}$ and was completely decomposed at 4.3$\times$10$^{-3}$ atm $O_{2}$ B $i_{2}$S $r_{2}$C $a_{2}$C $u_{3}$ $O_{10+x}$ phase was not formed by the solid state reaction from the mixutre of $i_{2}$S $r_{2}$CaCu.sub 2/ $O_{8+x}$, $Ca_{2}$Cu $O_{3}$ and CuO down to 2.2$\times$10.sub -3/ atm O.sub 2/ but formed by the solidifciation of the formed from the mixture of the intermediate compounds in the Bi-Sr-Ca-Cu-O system and the fromation temperature of Bi.sub 2/S $r_{2}$C $a_{2}$Cu.$_{3}$ $O_{10+x}$ can be lowered by reducing oxygen partial pressure.e.e.ure.e.e.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.160-161
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• 2009

In this study, in order to develop the lead free piezoelectric ceramics with excellent piezoelectric properties, (Na,K)$NbO_3$ ceramics according to the amount CuO addition were fabricated using a conventional mixed oxide process and their piezoelectric and dielectric characteristics were investigated. At the 0.8mol% CuO added composition, density, electromechanical coupling factor(kp), echanical quality factor(Qm), dielectric constant$(\varepsilon_r$) and piezoelectric constant($d_{33}$) showed the optimum value of $4.459g/cm^3$, 0.469, 540, 410, 69.57pC/N, respectively.

• Journal of the Korean institute of surface engineering
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• v.55 no.2
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• pp.63-69
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• 2022

Preparing various types of thin films of oxide semiconductors is a promising approach to fabricate efficient photoanodes and photocathodes for hydrogen production via photoelectrochemical (PEC) water splitting. In this work, we investigate the feasibility of an efficient photocathode for PEC water reduction of a p-type oxide semiconductor cupric oxide (CuO) thin film prepared via a facile method combined with sputtering Cu metallic film on fluorine-doped thin oxide (FTO) coated glass substrate and subsequent thermal oxidation of the sputtered Cu metallic film in dry air. Characterization of the structural, optical, and PEC properties of the CuO thin film prepared at various Cu sputtering powers reveals that we can obtain an optimum CuO thin film as an efficient PEC photocathode at a Cu sputtering power of 60 W. The photocurrent density and the optimal photocurrent conversion efficiency for the optimum CuO thin film photocathode are found to be -0.3 mA/cm² and 0.09% at 0.35 V vs. RHE, respectively. These results provide a promising route to fabricating earth-abundant copper-oxide-based photoelectrode for sunlight-driven hydrogen generation using a facile method.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.8
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• pp.636-640
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• 2011

The lead-free $0.98(Na_{0.5},K_{0.5})NbO_3-0.02Ba(Zr_{0.52},Ti_{0.48})O_3$-(hereafter NKN-BZT) CuO, ZnO-doped ceramics were prepared using a conventional mixed oxide method. NKN-BZT ceramics doped CuO, ZnO have superior structural and electrical properties than pure NKN-BZT ceramics. For the NKN-BZT-ZnO ceramics sintered at $1,120^{\circ}C$, piezoelectric constant ($d_{33}$) of sample showed the optimum values of 172 pC/N. The $0.98(Na_{0.5},K_{0.5})NbO_3-0.02Ba(Zr_{0.52},Ti_{0.48})O_3$-ZnO ceramics are a promising candidate for lead-free piezoelectric materials.