• Journal of Pharmaceutical Investigation
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• v.8 no.1
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• pp.27-36
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• 1978

Spherical granules of anti-inflammatory enzyme were prepared by mixer granulation and the recovery rate of enzyme activity by processing was compared with tablet ones. In the enteric granule coating .processing, the effect of the amount of coating solution and the conentration of fatty alcohol on disintegration and stabilities on the accelerated conditions were also studied. Being prepared in non-pressure and non-aqueous condition, spherical granules of enzyme made better recovery of enzme activity than tablet ones by 10 times. Combined processing of both mixer granulation and enteric granule film coating provided the noble enteric coated granules, in the sense of disintegration and stabilities, was obtained from using 0.125% fatty alcohol in coating solution.

• Journal of Power System Engineering
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• v.6 no.1
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• pp.74-81
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• 2002

The characteristics of corrosion resistance for the surface of ductile cast iron(GCD40) by plasma nitriding process have been studied in terms of electrochemical polarization behaviors including corrosion potential($E_{corr}$), anodic polarization trends, polarization resistance($R_p$), and also have been studied microstructures, hardness and specific wear of nitrided layer Nitrided layer showed an enhanced hardness values in all the plasma nitriding condition investigated. In the result of wear test, specific wear of nitrided specimens were much decreased than that of non-treated specimens. In the results of XRD, ${\gamma}'phase\;and\;{\varepsilon}$ phase were detected in nitrided surface. And it was found that ${\varepsilon}$ phase was decreased and ${\gamma}'phase$ was increased respectively, as the nitriding time became longer. In the test of corrosion resistance, natural potentials in all the nitrided specimens were towards noble directions than in the case of non-treated specimens. The measurement of electrode potentials revealed that corrosion resistivity of plasma nitrided specimens were higher than in the case of the non-treated specimens.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.10 s.241
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• pp.1156-1162
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• 2005

In this study, a noble method is proposed to prevent the edge overcoating (EOC) that may develop near the edge of the steel strip in the gas wiping process of continuous hot-dip galvanizing. In our past study (Trans. of the KSME (B), Vol. 27, No. 8, pp. $1105\~1113$), it was found that EOC is caused by the alternating vortices which are generated by the collision of two opposed jets in the region outside the steel strip. When the two opposed jets collide at an angle much less than $180^{o}$, non-alternating stable vortices are established symmetrically outside the steel strip, which lead to nearly uniform pressure on the strip surface. In order to deflect both jets downward by a certain angle, a cylinder with small diameter is installed tangentially to the exit of the lower lip of the two-dimensional jet. In order to find an optimum cylinder diameter, the three dimensional flow field is analysed numerically by using the commercial code, STAR-CD. And the coating thickness is calculated by using an integral analysis method to solve the boundary layer momentum equation. In order to compare the present noble method with the conventional baffle plate method to prevent the EOC, the flow field with a baffle plate is also calculated. The calculation results show that the tangentially installed cylinder at the bottom lip of the jet exit is more effective than the baffle plate to prevent EOC.

• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.28-51
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• 2018

Graphitic carbon nitride ($g-C_3N_4$) as a fascinating visible light active semiconductor photocatalyst has medium band gap, non-toxic nature, stable chemical structure and high thermal stability. Recently, intensive researches are focused on photocatalytic activity of $g-C_3N_4$ for wastewater treatment. This review demonstrates latest progress in fabrication of graphitic carbon nitride $C_3N_4$ incorporated nanocomposite to explore photocatalytic ability for water purification. The $g-C_3N_4$-based nanocomposites were categorized as $g-C_3N_4$ metal-free nanocomposite, noble metals/$g-C_3N_4$ heterojunction, non-metal doped $g-C_3N_4$, transition and post transition metal based $g-C_3N_4$ nanocomposite. Apart from fabrication methods, we emphasized on elaborating the mechanism of activity enhancement during photocatalytic process.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2000.11a
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• pp.1-6
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• 2000

This paper was studied on the crevice corrosion behavior of SS 400 in marine environment. In 0%, 2%, 3.5%, 5% NaCl solution, the aspect of the crevice corrosion and polarization behavior under the crevice corrosion was investigated. And Weight loss rate of SS 400 with crevice and non-crevice was measured according to the NaCl concentration. The main results obtained are as follows : 1) Under crevice corrosion, the corrosion potential become less noble as the concentration of NaCl solution increased. 2) The current density under open circuit potential was high drained as concentration of NaCl solution increased by 3.5% but the concentration increased over 3.5%, the current density was low drained. 3) The weight loss rate of SS400 was increased as concentration of NaCl solution increased by 3.5% but the concentration increased over 3.5%, that of SS400 was decreased.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.68.1-68.1
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• 2017

수소에너지의 무한한 가능성이 주목됨에 따라 과전압이 높은 산소 발생 촉매의 효율 향상 및 제작비용의 절감은 중요한 문제가 되어왔다. 백금계 촉매는 높은 효율과 낮은 과전압을 가지고 있지만 적은 매장량과 비싼 가격으로 수전해의 상용화에 큰 장애물이 되어왔다. 전이 금속 산화물 촉매는 가격이 저렴하고 형상과 크기 등에 따라 백금계 촉매에 비등한 성능을 발휘할 수 있다. 본 발표에서는 산소발생을 위한 촉매로서 Cu와 Co를 co-precipitation법을 이용하여 $Cu_xCo_{(3-x)}O_4$를 제작하고 이를 셀, 스택에 적용한 방법을 소개한다. 본문에서는 용액의 pH를 다르게 합성하여 Cu와 Co의 비율을 변화시켜 형상, 결정성을 조절할 수 있었고, 이러한 다른 조건에서 산소 발생 성능의 변화를 측정하였다. 최종적으로 최적의 성능을 나타내는 산소 발생 촉매를 셀 및 스택에 적용하여 실제적인 성능을 측정하였다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.168.1-168.1
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• 2017

화석연료를 대체하기 위한 에너지원으로서 수소에너지에 대한 연구가 활발히 진행되고 있다. 수전해는 무한 청정한 물을 전기분해하여 수소를 생산하는 기술로써 대표적으로 알칼리 수전해(alkaline water electrolysis, AWE)와 고분자 전해질막 수전해(polymer electrolyte membrane water electrolysis, PEMWE)가 있다. 그 중, AWE는 알칼리 분위기에서 물분해 반응이 진행되어 촉매의 부식 위험성이 비교적 낮기 때문에 상대적으로 저렴한 비귀금속 산화물 촉매를 사용할 수 있다는 장점이 있다. 본 연구에서는 비귀금속인 Cu, Co를 이용하여 $CuCoO_4$를 합성한 후 산소 발생 촉매 물질로 활용하여 산소 발생 반응(Oxygen Evolution Reaction, OER)특성을 고찰하였다.

• Proceedings of the Membrane Society of Korea Conference
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• 1995.10a
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• pp.43-44
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• 1995

The diffusion behavior of liquid into polymer has been described by Fick's law, but the departure from Fickian diffusion is frequently found. In this study, 'noble' expressions for the rates of relaxation and sorption are introduced to eliminate these limitations. The ralaxation-sorption coupled mechanism model are based on the possibility of contacting liquid molecule and the active site which has the numerical concept of free volume. The concept has an analogy of reaction rate expressed by the possibility of collision with molecules and used in adsorption and reactive extraction etc. The new model simulated by Rungc-Kutta method for initial-value problem and Fickian diffusion is caompared with experimental data. The results show that the ralaxation-sorption coupled mechanism is able to account well for Fickian and non-Fickian sorption behavior including sigmoid and two-stage. In addition, this model has a chance of expansion to multi-component sorption with ease.

• Journal of the Korean institute of surface engineering
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• v.12 no.3
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• pp.174-179
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• 1979

The effects of brightness, electrochemical behaviour on the organic additives, such as aldehydes, polymers, amines and condensed product obtained from epichlorohydrin and nicotinamide, in cyanide zinc electrolplating bath have been studied by controlled potential electrolyser. The results were summerized as follows: (1) It was found that the addition of only one compound of these organic compounds in the bath was unsuitable but mixture of anisaldehyde or monoethanolamine and condensed product as suitable as brightener. (2) The cathodic polarization curve of polymers or aldehydes in cyanide zinc electroplating bath was almost the same but the cathodic polarization curve of condensed product remarkable shifted to noble potential more than non-additive curve.

• Journal of the Korean institute of surface engineering
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• v.39 no.5
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• pp.229-234
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• 2006

Diamonds have been widely employed as polishing media for precise machining and noble substrates for microelectronics. The recent development of the split sphere press has led to the enhancement of low quality natural diamonds. Synthesized and treated diamonds are sometimes traded deceptively as high quality natural diamonds because it is hard to distinguish among these diamonds with conventional gemological characterization method. Therefore, we need to develop a new identification method that is non-destructive, fast, and inexpensive. We proposed using new methods of UV fluorescence and X-ray Lang topography for checking the local HPHT stress field to distinguish these diamonds from natural ones. We observe unique differences in the local stress field images in treated diamonds using UV fluorescence and Lang topography characterization. Our result implies that our proposed methods may be appropriate for identification of the treated diamonds.