• Proceedings of the Korea Water Resources Association Conference
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• 1992.07a
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• pp.325-328
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• 1992

The purpose of this research is to develop the technique of heavy metal removal from wastewater. The research is divided into two parts, one part uses complex precipitation and the other uses adsorption. In the first part of the study, humic acid is used as the complex agent, humic acid is a polyelectrolyte with a high complexation affinity. Lead, copper, zinc and cadmium were studied for their complex precipitation efficiencies. In the batch studies, humic acid was effective in removing 100% of the lead and 48.2% of the copper respectively from wastewater without anytreatment. The efficiency of cadmium and zinc, however, was very low. In the second part of the study, wastewater is introduced at the top of a silicagel adsorption column and then bottom effluent concentration is analyzed. The results of the analysis are used to draw a breakthrough curve.

• Journal of the Korean Chemical Society
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• v.7 no.4
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• pp.280-282
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• 1963

Fe (III)-cupferrate composition in chloroform phase was determined by molar ratio method, continuous variation method and slope ratio method spectrophotometrically at 325m$\mu$ and 385m$\mu$ wavelength. At both wavelength, compositions of the complex were Fe$Cupf_3$.

• Journal of the Korean Chemical Society
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• v.35 no.2
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• pp.135-141
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• 1991

The complexation of N,N'-oxalylbis(salicylaldehyde hydrazone) (OBSH) with Zn (II), Cd (II), and Pb(II) ions was studied by polarographic method in DMSO solution. The order of stability constants was Cd(II) < Zn(II) < pb(II), and all heavy metal ions formed stable complex with OBSH ligand. The stability constants of complexation were measured at various temperatures. As the results, enthalpy and entropy changes of the complexation were distributed on the complex stabilities.

• Journal of the Korean Applied Science and Technology
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• v.12 no.2
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• pp.115-120
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• 1995

Diazotization of 2-Amino-5-nitrophenol was Synthesized by the direct diazotization method. The diazonium salts are usually stabilized in the from of double salts. The double salts of zinc chloride are the Commonest, and the double salt method is Specially applicable to the yield-up of coupling. The azo dye(2-naphthol-1-(2'-diazo-5'-nitrophenol)) is Converted into a chromium Complex by heating($100^{\circ}C$) with chromic formate, and DMF. The removal of inorganic salts from dyestuffs was performed in DMF solvent. This effect was more pronounced. From these results, It was obtained to liquid dyestuffs of metal complex with High fastness and high adsorption.

• YAKHAK HOEJI
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• v.53 no.6
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• pp.342-350
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• 2009

The interaction of cadmium (II) ion with quercetin and (+)-catechin was investigated in aqueous solution at various pH. The flavonoid/cadmium stochiometries for cadmium (II) binding to quercetin and (+)-catechin have been determined by UV-vis spectroscopy. 1 : 1 Cd (II)-Flavonoid complex had a maximum absorbance and showed the bathochromic shift of the long-wavelength band of the UV-vis spectra in the alkaline pH, that occurs upon complexation, due to a ligandto-metal charge transfer. These results suggest that Cd (II)-flavonoid complex has the optimal condition of chelation in 0.2 M $NH_3$ - 0.2 M $NH_4Cl$ (pH 8.0) solution.

• Bulletin of the Korean Chemical Society
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• v.25 no.1
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• pp.37-41
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• 2004

A new tridentate ligand incorporating a monoxime and thiosemi-carbozone moieties has been synthesized. Its copper(II), nickel(II) and palladium(II) complexes have been prepared and characteirzed by physical and spectral methods. Elemental analyses and spectroscopic data of the metal complexes are consistent with the formation of a mononuclear copper(II) complex and binuclear complex with both nickel(II) and palladium(II). In the copper(II) complex the fourth coordination site is occupied by nitrate ion. In the binculear complexes the fourth coordination site is occupied by the deprotonated oxime oxygen of the ligand coordinated to the other metal.

• The Korean Journal of Food And Nutrition
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• v.7 no.2
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• pp.128-136
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• 1994

Mackerel muscle protein hydrolysates, which were prepared from defatted mackerel meal by proteases such as complex enzyme, alcalase, bromelain, pancrease, pepsin, w-chymotrypsin, trypsin and papain, were tested for the antioxidative action against linoleic acid. Among proteases tested, the hydrolysates obtained from the treatment of complex enzyme, bromelain and alcalase showed higher antioxidative effects. Also, the hydrolysates showed the synergistic effects with o-tocopherol and the inhibitory effects for peroxidation of metal ions(Fe3+, Cua+) From the profiles of fractionation of the hydrolysates with Bio-gel P-2 column, the most active fractions, part I(complex enzyme-derived) and part e(bromelain-derived), had below MW 1,400 and the antioxidative effects were closely related to the binding capacity with metal ion(Cua+). Amno acid composition of the part I was abundant in histidine, arginine, phenylalanine and lysine, and the part e was abundant in lysine, glutamic acid and leucine.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.2
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• pp.80-85
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• 2021

In the fourth industrial revolution, the demand for metal three-dimensional (3D) printing technology is rapidly increasing. Metal 3D printing is an efficient method for manufacturing products because the method reduces material waste compared to subtractive manufacturing. In addition, products with complex shapes, such as turbine blades, can be easily produced using metal 3D printing because the method offers a high degree of freedom. However, due to the long production time of metal 3D printing, mass production is impossible, and post-processing is necessary due to its low precision. Therefore, it is necessary to develop a new hybrid process that can efficiently process metals and to develop a metal 3D-printing-based hybrid processing system technology to secure high processing precision and manufacture complex shapes. In this study, the structural stability of a metal 3D printer based hybrid machining center was analyzed through structural analysis before its development. In addition, we proposed a design modification that can reduce the weight and increase the stiffness of the hybrid machining center by performing shape lightning based on the structural analysis results.

• Bulletin of the Korean Chemical Society
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• v.7 no.5
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• pp.334-337
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• 1986

The preparation of the metal-metal bonded complex $Cp_2ZrClFeCp(CO)_2$ has been achieved by the reaction of $Cp_2ZrCl_2$ and strong nucleophile $NaFeCp(CO)_2$. The more soluble metal-metal bonded complexes $Cp_2ZrRFeCp(CO)_2(R=CH_3,\;n-C_8H_{17}$) have also been prepared through the reaction of Cp$_{2}$ZrRCl and NaCpFe(CO)$_{2}$. The complexes were characterized by IR, Raman, $^{1}$H NMR and Mass spectra. The complete absorption (100-3800 cm$^{-1}$) spectra for the three metal-metal bonded molecules are reported and the bands of each vibration were assigned.

• Bulletin of the Korean Chemical Society
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• v.31 no.1
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• pp.202-204
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• 2010