• Title/Summary/Keyword: synthetic solution

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A STUDY ON AMIDI HYDROLYSIS CATALYZED BY MITAL COMPlEXES (금속착물로 아미드 가수분해 촉매화에 관한 연구)

  • 김병순;오영희
    • Journal of Environmental Science International
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    • v.5 no.5
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    • pp.579-583
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    • 1996
  • This study is involved to develop new catalysts to decompose plastics, detergents and surfactants containing synthetic peptide bonds. As the first year research, the catalytic-hydrolysis of amide bond in copper complex was accomplished. The hydrolysis reaction in aqueous solution was monitored by UV/VIS spectroscopy. As the pH of the solution Is increased and the temperature is raised, the reaction rate increases. The reaction rate is observed as the first order kinetic behavior for the copper complex. The metal catalyzed hydrolysis mechanism is proposed cia metal-hydroxide in the pH region of 5.5 to 6.3. The results of characterization of the catalytic reaction mechanism can be applied to develop new catalysts for peptide bond degradation in further research.

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Detection of a Magnetic Dipole by Means of Magnetic Gradient Tensor (자력 변화율 텐서를 이용한 자기 쌍극자 위치 결정)

  • Rim, Hyoung-Rea
    • Journal of the Korean earth science society
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    • v.32 no.6
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    • pp.595-601
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    • 2011
  • In this paper, I propose the algorithm that the location of a magnetic dipole can be detected from the magnetic gradient tensor. I induce the location vector of a vertically magnetizated dipole from the magnetic gradient tensor. Deficit of magnetic moment of magnetic dipole makes the induced location information incomplete. However, if the observation of magnetic gradient tensor would be collected on more points, the algorithm is able to catch the location of the magnetic dipole by clustering the solution of the proposed algorithm. For example, I show that the synthetic case of borehole observation of magnetic gradient tensor can find the source location successively by picking common solution area.

Removal Characteristics of Sr Ion by Na-A Zeolite Synthesized using Coal Fly Ash Generated from a Thermal Power Plant (화력발전소에서 발생하는 석탄비산재로부터 합성한 Na-A 제올라이트의 Sr 이온 제거 특성)

  • Lee, Chang-Han;Kam, Sang-Kyu;Lee, Min-Gyu
    • Journal of Environmental Science International
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    • v.26 no.3
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    • pp.363-371
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    • 2017
  • This study evaluates the adsorption properties of Sr ions in an aqueous solution of the synthetic zeolite (Z-Y1) prepared using coal fly ash generated from a thermal power plant. In order to investigate the adsorption characteristics, the effects of various parameters such as the initial concentrations of Sr ion, contact time, and solution pH were investigated in a batch mode. The Langmuir and Redlich-Peterson model fitted the adsorption isotherm data better than the Freundlich model. The maximum adsorption capacity of Sr ions, as determined the Langmuir model, was 181.68 mg/g. It was found that by varying the Sr ion concentration, pH, and temperature, the pseudo-second-order kinetic model describes the adsorption kinetics of the Sr ion better than the pseudo-first-order kinetic model. The calculated thermodynamic parameters of ${\Delta}H^0$ and ${\Delta}G^0$ showed that the adsorption of Sr ions on Z-Y1 was occurred through a spontaneous and an endothermic reaction. We found that the adsorption of Sr ions by Z-Y1 was more affected by pH than by temperature and Sr ion concentration.

Single Crystal Growth of Synthetic Emerald by Reflux Method of Temperature Gradient used Natural Beryl (천연베릴을 이용한 온도구배 환류법에 의한 합성 Emerald 단결정 육성)

  • 최의석;김무경;이종민;안영필;서청교;안찬준
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1996.06a
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    • pp.519-521
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    • 1996
  • Emerald (3BeO.Al2O3.6SiO2 : Cr3+) single crystals were crystals were grown by reflux method of temperature gradient in the flux solution of Li2O-MoO3-V2O5 system. The composition of flux materials were 3 mole ratio of MoO3-V2O5/Li2O, subtituted 0.2 mole% of K2O, Na2O, Nb2O5 etc to Li2O content, solved 10-15% of beryl to flux quantity and doped 1% of Cr2O3 to emerald amount. Those of mixing were melted at 110$0^{\circ}C$ in Pt containers of the 3 zone furnace of melt-growth-return to circulate continniously, specially it has been grown large emerald single crystal when thermal fluctuation was treated for 2hrs of once time a day at 1050-95$0^{\circ}C$ in growth zone, substitutional solid solution effect of Cr+3 ion for Al+3 to the growth of emerald single crystal was good. Emerald single crystals were c(0001) hexagonal crystal face of preferencial growth direction and m(1010) post side. When it had been durated for 5 months emerald single crystals of the firet size of 0.6mm thickness of seed crystal were grown 32$\times$65mm(c x m) of maximum size and 6.2mm thickness.

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Improvement on Enzyme Immobilization in Polypyrrole-Glucose Oxidase Enzyme Electrode using Organic Solvent Additive I. Ultraviolet Spectroscopic Analyses (유기용매 첨가에 따른 Polypyrrole-Glucose Oxidase 효소전극의 효소고정화 향상 I. 자외선 분광분석)

  • 김현철;구할본
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.7
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    • pp.615-620
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    • 2002
  • In the case of immobilizing of glucose oxidase into polypyrrole (PPy) using electrosynthesis, the glucose oxidise (GOx) forms a coordinate bond with the polymers backbone. However, because of intrinsic insulation and net-chain of the enzyme, the charge transfer and mass transport are obstructed during the film growth. Therefore, the film growth is dull. We synthesized enzyme electrodes by electropolymerization added some organic solvent, such as ethanol and tetrahydrofuran (THF). The formative seeds of film growth was delayed by adding ethanol. The delay was induced by radical transfer between ethanol and pyrrole monomer. The radical transfer reactions shared the contribution of dopants between electrolyte anion and GOx polyanion. This led to increase amount of immobilized the enzyme in PPy. For the UV absorption spectra of synthetic solution before synthesis and after, in the case of ethanol added, the optical density was slightly decreased for the GOx peaks. It suggests amount of GOx in the solution was decreased and amount of GOx in the film was increased.

Synthesis of $BaTiO_3$ nanoparticle by a solvothermal method (Solvothermal 방법에 의한 $BaTiO_3$ 나노입자의 합성)

  • Yeo, Ki-Ho;Moon, Byung-Kee;Son, Se-Mo;Chung, Su-Tae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07b
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    • pp.732-734
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    • 2003
  • A solvothermal synthetic method to $BaTiO_3$ nanoparticle has been investigated in toluene solution with $BaTi(OR)_6$ as precursor. A precursor prepared from barium metal with toluene, isopropanol and titanium isopropoxide was used as a starting material. Weight ratio of precursor to solvent prepared in the mixture are 5/100, 10/100, 20/100 and 50/100wt%. At the weight ratio of 50/100wt%, $BaTiO_3$ butterfly twin crystalline(${\fallingdotseq}100nm$) was obtained after synthesis at $250^{\circ}C$ for 20hrs in an autoclave. X-ray diffraction and transmission electron microscopy showed that the product of 50/100wt% has crystallization. At 5/100, 10/100, and 20/100wt%, however, red colloidal solution was obtained after synthesis and crystalline phase of $BaTiO_3$ was not produced.

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Adsorption Kinetics of Cupper and Zinc Ion with Na-A Zeolite Synthesized by Coal Fly Ash (석탄 비산재로 합성한 Na-A형 제올라이트에 의한 구리와 아연 이온의 동역학적 흡착 특성)

  • Lee, Chang-Han
    • Journal of Environmental Science International
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    • v.20 no.12
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    • pp.1607-1615
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    • 2011
  • The adsorption performance of cupper and zinc ions($Cu^{2+}$ and $Zn^{2+}$) in aqueous solution was investigated by an adsorption process on reagent grade Na-A zeolite(Z-WK) and Na-A zeolite (Z-C1) prepared from coal fly ash. Z-C1 was synthesized by a fusion method with coal fly ash from a thermal power plant. Batch adsorption experiment with Z-C1 was employed to study the kinetics and equilibrium parameters such as initial metal ions concentration and adsorption time of the solution on the adsorption process. Adsorption rate of metal ions occurred rapidly and adsorption equilibrium reached at less than 120 minutes. The kinetics data of $Cu^{2+}$ and $Zn^{2+}$ ions were well fitted by a pseudo-second-order kinetics model more than a pseudo-first-order kinetics model. The equilibrium data were well fitted by a Langmuir model and this result showed $Cu^{2+}$ and $Zn^{2+}$ adsorption on Z-C1 would be occupied by a monolayer adsorption. The maximum adsorption capacity($q_{max}$) by the Langmuir model was determined as $Cu^{2+}$ 99.8 mg/g and $Zn^{2+}$ 108.3 mg/g, respectively. It appeared that the synthetic zeolite, Z-C1, has potential application as absorbents in metal ion recovery and mining wastewater.

Albumin Release from Biodegradable Hydrogels Composed of Dextran and Poly(Ethylene Glycol) Macromer

  • Kim, In-Sook;Jeong, Young-Il;Kim, Do-Hoon;Lee, Yun-Ho;Kim, Sung-Ho
    • Archives of Pharmacal Research
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    • v.24 no.1
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    • pp.69-73
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    • 2001
  • Biodegradable hydrogels based on glycidyl methacrylate dextran (CMD) and dimethacrylate poly(ethylene glycol) (DMP) were proposed for colon-specific drug delivery. GMD was synthesized by coupling of glycidyl methacylate with dextran in the presence of 4-(N, N-dimethylamino)pyridine (DMAP) using dimethylsulfoxide as a solvent. Methacrylate-terminated poly (ethylene glycol) (PEG) macromer was prepared by the reaction of PEG with methacryloyl chloride. CMD/DMP hydrogels were prepared by radical polymerization of phosphate buffer solution (0.1 M, pH 7.4) of GMD and DMP using ammonium peroxydisulfate (APS) and UV as initiating system. The synthetic GMD, DMP and GMD/DMP hydrogels were characterized by fourier transform infrared (FT-lR) spectroscopy. The FITC-albumin loaded hydrogels were prepared by adding FITC-albumin solution before UV irradiation. Swelling capacity of GMD/DMP hydrogels was controlled not only by molecular weight of dextran, but also by incorporation ratio of DMP Degradation of the hydrogels has been studied in vitro with dextranase. FITC-albumin release from the GMD/DMP hydrogels was affected by molecular weight of nextran and the presence of dextranase in the release medium.

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A Study on the Korean Traditional Dyeing Procedure of Carthamus Flower (고대 홍화(Carthamus tinctorius L.) 염색의 실험적 고찰)

  • Koh Kyong-shin;Bae Woo-shik
    • Journal of the Korean Society of Clothing and Textiles
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    • v.8 no.3
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    • pp.1-7
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    • 1984
  • Traditionally dyeing fabrics with pigment extracted from carthamus flower was a popular method of obtaining red color in Korea. Such a method existed in several countries throughout the world before the synthetic dyestuff was developed. However, the traditional procedures of using natural products in obtaining colored materials are completely forgotten in modern Korea. The details of dyeing procedures fare not well documented in literature, either. In this study the method of extracting and dyeing with carthamus flower is reconstructed from Korean literature and actually carried out in laboratorf. The reconstructed method is compared with those of Japan, China, France, and Egypt, and the scientific basis of such an ancient tradition is discussed. Carthamus contains two kinds of coloring components : yellow carthamin and red carthamone. Water-soluble carthamin is first extracted by repeated washing and is usually used for the initial soaking procedure. Then carthamone is extracted in alkali solution by adding ashes of dried plants such as carthamus stalks and bean hull. Finally the solution of carthamone is made acidic by adding schizandra juice for dyeing on fabrics.

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Application of nanofiltration membrane in the recovery of aluminum from alkaline sludge solutions

  • Cheng, Wen Po;Chi, Fung Hwa;Yu, Ruey Fang;Tian, Dun Ren
    • Advances in environmental research
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    • v.5 no.2
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    • pp.141-151
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    • 2016
  • Large amounts of aluminum hydroxide ($Al(OH)_3$) exist in water purification sludge (WPS) because of the added aluminum coagulant in water treatment process. Notably, $Al(OH)_3$ is an amphoteric compound, can be dissolved in its basic condition using sodium hydroxide to form aluminate ions ($Al(OH)_4{^-}$). However, in a process in which pH is increasing, the humid acid can be dissolved easily from WPS and will inhibit the recovery and reuse of the dissolved aluminate ions. This study attempts to fix this problem by a novel approach to separate $Al(OH)_4{^-}$ ions using nanofiltration (NF) technology. Sludge impurity in a alkaline solution is retained by the NF membrane, such that the process recovers $Al(OH)_4{^-}$ ions, and significantly decreases the organic matter or heavy metal impurities in the permeate solution. The $Al(OH)_4{^-}$ ion is an alkaline substance. Experimental results confirm that a recovered coagulant of $Al(OH)_4{^-}$ ion can effectively remove kaolin particles from slightly acidic synthetic raw water.