• Journal of the Korean Chemical Society
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• v.56 no.2
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• pp.228-235
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• 2012

A $N_2O_2$ Schiff base ligand, N,N'-bis(4-methoxysalicylidene)phenylendiamine (4-$CH_3O$-salphen) was synthesized. Using the 4-$CH_3O$-salphen, the spectrophoto-metric quantitative analysis of Cu(II) ion in aqueous solution was performed. The optimum condition for the quantitative analysis of Cu(II) ion was determined as the following; the concentration of 4-$CH_3O$-salphen is $2.0{\times}10^{-4}\;mol/L$, ratio between solvent DMSO and water is 50/50(v/v), pH is 5.5. After 1 hr water incubation at $55^{\circ}C$ and then the absorbance measurements at 388 nm, a calibration curve (${\varepsilon}=3.6{\times}10^4\;mol^{-1}cm^{-1}$) with a correlation coefficient ($R^2$=0.9963) was obtained in this condition. Using this optimized condition, the quantitative analysis of Cu(II) ion was performed with various samples such as hot spring water, semiconductor factory waste water and treated water from sewage treatment plant. The average value of the measured values agreed well with standard value with a range of 0.6~5.4%. The limit of determination was 31.77 ng/mL ($5.0{\times}10^{-7}\;mol/L$).

• Journal of the Korean Chemical Society
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• v.51 no.1
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• pp.31-35
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• 2007

The tripodal copper(II) complex [Cu(pmea)(H2O)](ClO4)2·H2O (1) (pmea = bis[(2-pyridyl)methyl]-2-(2-pyridyl)ethylamine) has been synthesized and structurally characterized by X-ray diffraction method. It crystallizes in the triclinic system P-1 with a = 9.9362(9), b = 15.7299(17), c = 18.0562(11) A, α = 68.760(8), β = 76.331(6), γ = 77.092(9)°, V = 2526.2(4) A3, Z = 2. Each copper atom reveals a distorted square pyramidal with three nitrogen atoms of the pmea ligand and water molecule occupying the basal plane and one nitrogen atom from the pyridine ring according the axial position. The cyclic voltammogram of 1 undergoes reversible one-electron oxidation to the CuIII and reversible one-electron reduction to the CuI.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.7
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• pp.1067-1075
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• 2007

Twenty eight 3-4 month old castrated Black Bengal kids (Capra hircus) were used to determine the effects of source and level of dietary copper (Cu) concentration on their performance and nutrient utilization. Cu was supplemented (0, 10, 20 and 30 mg/kg diet DM) as copper sulfate ($CuSO_4$, $5H_2O$) or copper proteinate (Cu-P). Kids were fed a basal diet containing maize (19.5%), soybean (17.0%), deoiled rice bran (56.5%), molasses (4.0%), di-calcium phosphate and salt (1.0% each) and mineral and vitamin mixture (0.5% each) supplements at 3.5% of body weight to meet NRC (1981) requirements for protein, energy, macro minerals and micro minerals, excluding Cu. The basal diet contained 5.7 mg Cu/kg, 122.5 mg Fe/kg, 110 mg Zn/kg, 0.26 mg Mo/kg and 0.32% S. $CuSO_4$ or Cu-P was added to the basal diet at the rate of 10, 20 and 30 mg/kg. Kids were housed in a well ventilated shed with facilities for individual feeding in aluminum plated metabolic cages. Blood samples were collected from the jugular vein on d 0, 30, 60 and 90 to determine hemoglobin (Hb), packed cell volume (PCV), total erythrocyte count (TEC), total leukocyte count (TLC) and serum enzymes (alkaline phosphatase, alanine transferase and aspertate transferase). A metabolism trial of 6 days duration was conducted after 90 days of experimental feeding. Statistical analysis revealed that source and level of Cu supplementation improved live weight gain (p<0.04) and average daily gain (p<0.01). No significant contribution of source and level of Cu to alter serum serum enzymes was evident. Goats fed Cu-P tended to have higher Hb, PCV and TEC than with $CuSO_4$ supplementation. Cu-P increased digestibility of ether extract (EE, p<0.02) and crude fiber (p<0.05) and showed an increasing trend (p<0.09) for digested crude protein (CP) and crude fiber (CF). Supplemental dose of Cu linearly improved (p<0.02) digestibilities of dry matter (DM), organic matter (OM), EE and nitrogen free extract (NFE). Though the absorption of nitrogen (N) was not affected (p>0.10) by both source and dose of Cu, N retention was affected (p<0.04) and there was a significant $Source{\times}Dose$ interaction (p<0.05). Final body weight (BW) was not influenced (p>0.10) by the source of Cu but increasing dose of Cu increased (p<0.04) the BW of kids. TDN intake (g/kg $W^{0.75}$) was higher (p<0.05) with the increased dose of Cu and there was a significant $Source{\times}Dose$ interaction. It was concluded that supplementation of Cu from different sources and varying dose level in a concentrate based diet may improve performance, nutrient utilization and plane of nutrition in castrated Black Bengal kids. The effects on performance and nutrient utilization are more pronounced with Cu-P than $CuSO_4$ supplementation. Higher dose of Cu showed better result than lower dose.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.6
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• pp.1021-1026
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• 2000

The removal of cadmium, copper and chromium ions was carried in a phase transfer reactor using W/O(water in oil) microemulsion containing sodium di[2-ethylhexyl] sulfosuccinate(AOT) and isooctane system. Removal efficiencies and mass transfer rate of $Cd^{2+}$, $Cu^{2+}$ and $Cr^{3+}$ were increasing with increasing pH of aqueous solution. However, $Cr^{6+}$ was not extracted by W/O microemulsion with AOT/isooctane system. It was found that removal of heavy metal ions were required an attractive electrostatic interaction between the metal ions and W/O microemulsion. The relationship between mass transfer rate. Jo of $Cd^{2+}$, $Cu^{2+}$ and $Cr^{3+}$ and pH of aqueous solution by W/O microemulsion suggested.

• Journal of Korea Foundry Society
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• v.20 no.4
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• pp.254-259
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• 2000

Metal matrix composites(MMCs) reinforced with hard particles have many potential application in aerospace structures, auto parts, semiconductor package, heat resistant panels, wear resistant materials and so on. In this work, the effect of SiC partioel sizes(50 and 100 ${\mu}m$) and additional elements such as Si, Cu and Ti on the microstructure and the wear property of $Al-5Mg-X(Si,Cu,Ti)/SiC_p$ composites produced by pressureless infiltration method have been investigated using optical microscopy, scanning eletron microcopy(SEM) with EDS(energy dispersive spectrometry), hardness test, X-ray diffractometer(XRD) and wear test. In present study, the sound $Al-5Mg-X(Si,Cu,Ti)/SiC_p$(50 and 100 ${\mu}m$) composites were fabricated by pressureless infiltration method. The $Al-5Mg-0.3Si-O.1Cu-O.1Ti/SiC_p$ composite with $50 {\mu}m$ size of SiC particle has higher hardness and better wear property than any other composite with $100{\mu}m$ size of SiC particle produced by pressureless infiltration method. The hardness and wear property of $Al-5Mg/SiC_p$(50 and 100 ${\mu}m$) composites were enhanced by the addition of Si, Cu and Ti in Al-5%Mg matrix alloy.

• Journal of the Korean Physical Society
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• v.73 no.10
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• pp.1546-1549
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• 2018

We have investigated core-levels of ZnO thin films at the interface with the graphene on Cu foil using in-situ X-ray Photoelectron Spectroscopy (XPS). Spectral evolution of C 1s, Zn 2p, and O 1s are observed in real time during RF sputtering deposition. We found binding energy (BE) shifts of Zn 2p and 'Zn-O' state of O 1s depending on ZnO film thickness. Core-levels BE shifts of ZnO will be discussed on the basis of electron transfer at the interface and it may have an important role in the electronic transport property of the ZnO/graphene-based electronic device.

• Journal of Conservation Science
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• v.36 no.3
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• pp.162-177
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• 2020

Research was conducted to characterize the copper production and smelting process with 11 copper smelting by-products (copper slag and copper crucible) excavated from the NA and LA areas at the Gwanbuk-ri archeological site in Buyeo. Scanning electron microscopy-energy dispersive spectroscopy, wavelength dispersive X-ray fluorescence, X-ray diffraction, and Raman microspectroscopy were employed in the analysis. The research results reveal that the copper slag from Gwanbuk-ri contained silicate oxide, magnetite, fayalite, and delafossite, which are typical characteristics of crucible slag and refined slag. The outward appearance and microstructure of the slag were grouped as follows: 1. glassy matrix + Cu prill, 2. glassy matrix + Cu prill + magnetite, 3. silicate mineral matrix + Cu prill, 4. crystalline (delafossite and magnetite) + amorphous (Cu prill), 5. magnetite + fayalite, and 6. slag from slag. The copper slags from Guanbuk-ri were found to contain residues of impurities such as SiO₂, Al₂O₃, CaO, SO₄, P₂O₅, Ag₂O, and Sb₂O₃ in their microstructure, and, in some cases, it was confirmed that copper, tin and lead are alloys. These results indicate that refining of intermediate copper(including impurities) and refining of alloys of copper(including impurities) - tin and refining of copper(including impurities) - tin - lead took place during the copper production process at Gwanbuk-ri, Buyeo.

• Proceedings of the Materials Research Society of Korea Conference
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• 1994.11a
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• pp.118-118
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• 1994

Processings of the P $b_2$S $r_2$( $Y_{1-x}$ C $a_{x}$) C $u_3$ $O_{8+{\delta}}$ (2213)system for x=0.4-0.6 to control deleterious oxidative decomposition have been studied. Our results show that comounds are stable at both low p $O_2$ and high p $O_2$ if they are suitably oxidized. Various oxidation and deoxidation procedures have been investigated in order tp determine the optimum hole concentration in the Cu $O_2$layers for the maximum $T_{c}$. In cases x=0.5 and x=0.6, the optimum hole concentration in the 2213-phase is achieved, but with accelerated oxidative decomposition. Destite this, the maximum $T_{c}$~80-83K for the 2213-phase can be deduced when x=0.5 to 0.6 to 0.6

• Bulletin of the Korean Chemical Society
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• v.9 no.5
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• pp.298-303
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• 1988

Kinetic studies on cupric ion ($Cu^{2+}$) oxidation of 1-benzyl- and 1-aryl-1,4-dihydronicotinamides (XNAH) in aqueous solution were performed. In the presence of dioxygen ($O_2$), the reaction followed first order kinetics with respect to both XNAH and $Cu^{2+}$. The oxidation reaction was found to be independent and parallel to the acid-catalyzed hydration reaction of XNAH. The catalytic role of $Cu^{2+}$ for the oxidation of XNAH in the presence of $O_2$ was attributed to $Cu^{2+}/Cu^+$ redox cycle by the reactions with XNAH and $O_2$. The second order rate constants of the Cu2+ oxidation reaction kCu, and acid-catalyzed hydration reaction $k_H$ were strongly dependent on the nature of the substituents in 1-aryl moiety. The slopes of log $k_{Cu}$ vs log $K_H$ and log $k_{Cu}$ vs ${\sigma}_p$ of the substituents plots were 1.64 and -2.2, respectively. This revealed the greater sensitivity of the oxidation reaction rate to the electron density on the ring nitrogen than the hydration reaction rate. A concerted two-electron transfer route involving XNAH-$Cu^{2+}$ complex was proposed for mechanism of the oxidation reaction.

• Journal of the Korean Ceramic Society
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• v.38 no.7
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• pp.597-601
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• 2001

The effect of CuO, $B_2$ $O_3$, $V_2$ $O_{5}$ and CuO-B $i_2$ $O_3$additives on microwave dielectric properties of (P $b_{0.45}$C $a_{0.55}$) [(F $e_{0.5}$N $b_{0.5}$)$_{0.9}$S $n_{0.1}$] $O_3$(PCFNS) were investigated. The PCFNS ceramics were sintered at 11$65^{\circ}C$. To decrease the sintering temperature for using as a low-temperature co-firing ceramics (LTCC), CuO, $B_2$ $O_3$, $V_2$ $O_{5}$ and CuO-B $i_2$ $O_3$were added to the PCFNS. As the content of CuO increased, the sintered density and dielectric constant increased and the temperature coefficient of resonance frequency ($\tau$$_{f}$) shifted to the positive value. When the CuO-B $i_2$ $O_3$were added, dielectric properties were $\varepsilon$$_{r}$ of 83, Q. $f_{0}$ of 6085 GHz, and $\tau$$_{f}$ of 8ppm/$^{\circ}C$ at a sintering temperature of 100$0^{\circ}C$. The relationship between the microstructure and properties of ceramics was studied by X-ray diffraction and scanning electron microscopy.icroscopy.y.icroscopy.y.