• 상하수도학회지
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• 제27권5호
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• pp.561-570
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• 2013

There are two types of rectangular secondary clarifier at biological nutrient removal (BNR) facility to settle MLSS; conventional activated sludge secondary clarifier and Gould Type I clarifier. In this study, the performances of two types at respective biological nutrient removal facility are compared using weekly operational data. Surface Overflow Rate (SOR), Surface Loading Rate (SLR), Sludge Volume Index (SVI), secondary effluent SS concentration are studied. It has found that Gould Type I has 3.5 times less average secondary effluent SS concentration that is 2.4 mg/L than that of conventional activated sludge secondary clarifier. Both SOR and SLR have shown little effect on secondary effluent SS concentrations at Gould Type I clarifier in contrary that SOR affects the secondary effluent SS concentrations at conventional activated sludge rectangular secondary clarifier. From this study, it is recommended that Gould Type I must be considered for secondary clarifier when BNR plant is designed.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2003년도 춘계학술발표논문집
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• pp.328-330
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• 2003

A surface equation of state for globular proteins at air-water interface accounting for the molecular structure, segment-segment, segment-solvent, and electrostatic interactions was proposed and compared to C-14 isotope experiments. This lattice model comprised a simplifying assumption that all adsorbed segments are in the form of trains. The number of segment adsorbed per molecule in case of bovine serum albumin linearly depended on the surface concentration whereas the lysozyme segments adsorbed at the interface were independent of surface concentration. The segment-solvent(water) interaction for both of proteins were found to be unfavorable owing to the proteins unfolding. From comparison of model computation and experimental data, BSA unfolded more than lysozyne because of the larger surface area of contact.

• 한국표면공학회지
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• 제32권3호
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• pp.317-330
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• 1999

The texture of electrodeposits changes from the orientation that places the lowest energy crystal facets parallel to the substrate under a condition of low ion concentration adjacent to the deposit, to the orientation that places the higher energy crystal facets parallel to the substrate as the ion concentration adjacent to the deposit increases. The electrodeposits have peculiar surface morphologies and microstructures depending on their textures, which in turn may affect their mechanical properties even when they are obtained in a similar electrolysis condition. The electrodeposits undergo recrystallization, when annealed. The recrystallization texture may be different from the deposition texture. These phenomena have been discussed.

• 대한화학회지
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• 제66권5호
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• pp.341-348
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• 2022

In this work, radio frequency magnetron sputtering was used to deposit zinc selenide thin films on p-type silicon (100) wafers and glass substrates in a high vacuum chamber. Several surface characterization instruments were implemented to study the thin films. X-ray photoelectron spectroscopy results revealed that oxidized Zn bound to Se (Zn-Se) at 1022.7 ± 0.1 eV becomes the dominant oxidized species when Se concentration exceeds 70%. Scanning electron microscopy coupled with energy dispersive spectroscopy showed that incorporating Se in Zn thin films will lead to formation of ZnSe grains on the surface. Contact angle measurements indicated that ZnSe-60 exhibited the lowest total surface free energy value of 24.94 mN/m. Lastly, ultraviolet-visible spectrophotometry and ultraviolet photoelectron spectroscopy data evinced that the energy band gap gradually increases with increasing Se concentration with ZnSe-70 having the highest work function value of 4.91 eV.

• 한국염색가공학회지
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• 제5권2호
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• pp.144-148
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• 1993

To increase the moisture content and thereby to reduce the static charge of polyacrylonitrile (PAN), thin layer surface photografting of acylamide (AAm) onto PAN fabrics by using benzophenone as a initiator with a mixtured solvent was carried. The effects of reaction conditions such as monomer, initiator concentrations, UV irradiation time and immersion time of fabrics on grafting were investigated. The percent grafting slightly increased with increasing monomer concentration, benzophenone concentration up to limiting value and thereafter decreased or level offed. The percent grafting was significantly increased with increasing irradiation and immersion times. The moisture regain increased with increasing the percent grafting. The static charge decreased with increasing the percent grafting.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2012년도 추계총회 및 학술대회 논문집
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• pp.95-95
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• 2012

In this study, the effect of $PO{_4}^{3-}$ ions on formation of PEO(Plasma Electrolytic Oxidation) films was investigated in aqueous solution. A minimum concentration of $PO{_4}^{3-}$ ions was necessary for the formation of PEO film on pure Mg and arcing voltage of pure Mg decreased with increasing $PO{_4}^{3-}$ ion concentration. Immersion test to evaluate the corrosion resistance of PEO-treated pure Mg and Mg alloys were conducted in 0.5M NaCl solution.

• 한국표면공학회지
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• 제32권3호
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• pp.331-335
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• 1999

Electroless plating nickel has superior mechanical property to electroplated nickel. Furthermore nickel can be coated on nonconducting substrate. In this research, electroless plating of nickel were conducted in different bath condition to find optimum conditions of electroless nickel plating for MEMS applications. The selectivity of activation method on several substrates was investigated. The effects of nickel concentration, reducing agent concentration and inhibitor on deposition rate were investigated. The effect of pH on deposition rate and content of phosphorous in deposited nickel was also investigated.

• 한국표면공학회지
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• 제26권4호
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• pp.175-182
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• 1993

Electroless plating of nickel was studied electrochemically in the presence of complexing agents. Nickel sulfate solution with dimethylamine borance(DMAB) as the reducing agent was used. Effects of temperature pH, concentration and complexing agents-citric acid, EDTA, tartaric acid-were studied.Experimental meas-urements showed that the rate of electroless nickel deposition was closely related to electrochemical parame-ters such as temdperature, pH, concentration and the properties of complexing agets.

• 한국식품과학회지
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• 제35권2호
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• pp.222-228
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• 2003

팽이버섯 추출물의 수율 및 전자공여작용, 총폴리페놀함량, tyrosinase 저해작용, 갈색도, 아질산염 소거작용에 대하여 반응표면분석에 의해 추출조건을 최적화 하였다. 팽이버섯 추출물의 수율변화는 에탄올 농도에 가장 큰 영향을 받았으며, 갈변도는 microwave power 보다는 에탄올 농도에 크게 영향을 받는 것으로 나타났으며, 아질산염 소거작용의 경우 에탄올 농도가 증가할수록, microwave power가 감소할수록 증가하는 경향을 나타내었다. 전자공여작용의 경우 에탄올 농도가 증가할수록 증가폭이 컸고, microwave가 증가할수록 조금씩 증가하는 경향을 보였다. 총 폴리페놀 함량의 경우 에탄올 농도가 증가할수록, microwave power가 클수록 추출물의 생리활성이 우수한 것으로 나타나 에탄올 농도가 추출시 중요한 공정인자임을 확인 할 수 있었다. 한편, tyrosinase 저해 작용의 경우 에탄올 농도보다는 microwave power에 영향을 받았는데 power가 작을수록 그 값은 크게 측정되었다. 따라서 팽이버섯의 최적 추출조건 범위는 microwave power $47.21{\sim}76.05$ watt, ethanol 농도 $10.25{\sim}43.56%$, 추출시간 5.72분으로 예측되었다.

• 한국재료학회지
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• 제12권1호
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• pp.58-67
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• 2002

In this study copper chloride(CuCl$_2$) solution was used as raw material to produce the fine copper oxide powder which has less than 1 $\mu\textrm{m}$ average particle size and has uniform particle size distribution by spray pyrolysis process. In the present study, the effects of reaction temperature, the injection speed of solution and air, the nozzle tip size and the concentration of raw material solution on the properties of produced powder were studied. The structure of the powder became much more compact with increasing the reaction temperature regardless of copper concentration of the raw material solution. The particle size of the powder increased accordingly with increasing the reaction temperature in case of 30 g/$\ell$ copper concentration of the solution. The particle size of the powder increased accordingly, and the surface structure of the powder became more porous with increasing the copper concentration of the raw material solution. When copper concentration in raw material solution was more than 100 g/$\ell$, all produced powder was CuCl regardless of reaction temperatures. When copper concentration in solution was below 30 g/$\ell$ and reaction temperature was higher than 90$0^{\circ}C$, CuO was the main phase. The surface of the powder tended to become porous with increasing the injection speed of solution. Particle size was increased and the surface of the powder showed severely disrupted state with increasing the nozzle tip size. The particle size was decreased and the particle size distribution was more uniform with increasing the air pressure through the nozzle.