• Journal of the Korean Ceramic Society
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• v.36 no.2
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• pp.220-224
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• 1999

For the process control of silicon nitride gelcasting, the effect of MeOH on the apparent gel induction time of slip, drying rate, and mechanical property of gelcast body were investigated. The apparent gel induction time showed maximum at 10~20 vol% MeOH and the drying rate of gelcast body increased in the ranged of 25~40%. The gelcast body was still machinable in the 40% of MeOH, though the mechanical property and relative density slightly decreased with increasing the amount of MeOH.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.199-199
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• 1999

상용의 PVC가 갖는 소수 특성을 개선하기 위해 산소, 아르곤, 수소 이온의 이온 보조 반응법을 이용하여 표면의 친수성을 증대시키고 이때 친수성 증가의 직접적 원인인 표면에너지 증가를 각각의 이온조사에 따라서 비교하였다. 이온 소스는 직경 5-cm의 cold hollow cathod ion gun을 이용하였으며 산소, 아르곤, 수소이온을 이온 조사량 5$\times$1014~1$\times$1017ions/cm2까지 변화시키고 산소의 유량을 0~8sccm까지 변화시키면서 표면 에너지 변화를 관찰하였다. 표면 에너지는 두 가지의 극성 용매인 물과 포름아마이드의 접촉각을 정적 접촉각 측정기를 이용하여 측정한 후에 이로부터 dispersion force와 polar force를 계산하여 얻었다. 계산된 결과를 보면 처리 전과후의 dispersion force의 변화는 거의 없으나 polar force는 크게 증가하였다. 이때 표면 에너지의 증가는 표면 형상의 변화와 극성을 띠는 친수성기의 증가로 여겨지며 각각의 경우에 대한 분석을 위해 AFM과 XPS 분석을 시행하여 각각의 이온에 따르는 표면 형상의 변화와 친수성기의 형성 및 상대적인 양을 비교하였다.

• Journal of the Korean Applied Science and Technology
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• v.27 no.2
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• pp.99-106
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• 2010

We have investigated the rheological behaviours of emulsions containing polymers. The polymers used in this study were polyacrylamide and carboxy vinyl polymer. The emulsion with polyacrylamide shows better prior preference than that with carboxy vinyl polymer on the skin texture. In the toxicity test, such as, LLNA cell toxicity, skin organ culture and human patch test, polyacrylamide was the appropriate materials for the cosmetics. The viscosity of polyacrylamide shows maximum value in neutral pH and good stability against temperature. The decreasing effect of viscosity against salt was not good enough but showed a better result than that of carboxy vinyl polymer. Two times the amount of polyacrylamide should be used for the formation of a similar viscosity of carboxy vinyl polymer. Yield value of polyacrylamide was low and the effect for the stabilizing emulsions was also low.

• Textile Coloration and Finishing
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• v.15 no.5
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• pp.301-309
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• 2003

Of the various types of dye that can be used to apply polyamide fibers, acid dyes and pre-metallised acid dyes are great in use so far. However, since these acid dyeings suffer from dye loss during laundering, recourse to an aftertreatment is usually necessary to achieve adequate fastness to washing. In the case of reactive dyes, the characteristically high washfastness of dyeings comes with the concomitant advantages of brightness and low environmental impact. Despite the obvious advantages, the commercialization of reactive dyes for polyamide fibers has not gained widespread success. In this context, the rewards for approach are likely to be considerable. Heterobifunctional reactive dyes were applied to polyamide fibers using various conditions. Optimum conditions and fixation were determined. The forms in which the vinylsulphone and hydrolyzed moieties were examined using HPLC-Mass. In addition, it was found that the extent of the washfastness secured, in terms of both change in color and staining of adjacent multifiber was being acceptable.

• Applied Biological Chemistry
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• v.34 no.2
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• pp.86-93
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• 1991

cis-Diamminedichloroplatinum(II)(CDDP), an antitumor drug, did not generate crosslink between bluetongue virus (BTV) capsid protein at moderate concentration. Cesium chloride density gradient centrifugation study revealed that protein-RNA crosslink was not detectable in CDDP treated BTV. CDDP treated BTV ds RNA showed remarkable change in the migration pattern in polyacrylamide gel electrophoresis. These results suggest that the reduction of BTV core associated transcriptase activity is most likely by the CDDP adduction to the genomic ds RNA rather than by the protein-RNA crosslink and/or protein-protein cross-link.

• The Korean Journal of Rheology
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• v.9 no.4
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• pp.183-189
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• 1997

본 연구에서는 고분자용액을 분산매로한 현탁액 내에서 입자의 수력학적확산에 관 한 실험적인 연구를 수행하여다. 입자로는 평균직경 275마이크론의 polymethlmethacrylate (PMMA)구형입자를 사용하였고, 분산매로는 PMMA 입자와 밀도르 맞춘 글리세린과 에틸 렌글리콜의 혼합용액에 고분자를 첨가하여 사용하였다. 고분자로는 분자량 6백만의 시약용 폴리아크릴아마이드를 사용하였다. 입자농도는 50%이었다. 용액의 농도는 0∼700ppm이었으 며 이러한 용액은 전단박화현상을 나타내지 않았다. 확산계수는 쿠엣장치 내에서 입자가 두 원통사이에서 아래쪽의 빈 공간으로 확산할 때 시간에 따른 점도측정결과로부터 예측하여 다. 본 연구의 결과 뉴튼성유체의 경우와는 달리 무차원확산계수(D/2)가 일정하지 않으며 전단율이 증가될수록 점점 감소하는 현상을 나타내었다. 고분자의 농도가 증가하는 경우에 는 무차원 확산계수가 감솨는 것을 볼수있었다. 이러한 무차원 확산계수의 감소는 유동하는 현탁액 내에서 입자간의 상호작용이 뉴튼성유체에 비하여 가역적인 것에 기인하는 것으로 판단된다.

• YAKHAK HOEJI
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• v.55 no.2
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• pp.154-159
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• 2011

During the search for a novel compound that can inhibit NF-${\kappa}B$ activation, 6-hydroxy-7-methoxychroman-2-carboxylic acid phenyl amide (KL-1156) was identified as a good inhibitor of NF-${\kappa}B$ activation. In the present study, we describe the synthesis of methylchroman-2-carboxylic acid N-(disubstituted)phenylamide derivatives (1 and 2 serieses). In addition, their inhibitory effects of NF-${\kappa}B$ are compared with activity of KL-1156 and SAR (structure activity relationship) are explored.

• YAKHAK HOEJI
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• v.57 no.6
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• pp.426-431
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• 2013

In our previous studies, 6-hydroxy-7-methoxychroman-2-carboxylic acid N-phenylamide (KL-1156) was identified as a good inhibitor of nuclear factor-${\kappa}B$ (NF-${\kappa}B$) activation. In continuation of our study, we describe the structure-activity relationship of chroman derivatives containing N-arylalkyl groups and their NF-${\kappa}B$ inhibitory activities. In addition, inhibitory effects of cell proliferation are evaluated against human cancer cell lines (NCI-H23 and PC-3). The most active compounds 3i and 3j contained diphenylethyl and diphenylpropyl side chain on amide nitrogen.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.4 no.1
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• pp.11-16
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• 1997

Sorption studies involving the sorption of n-propanol by an Amorphous Nylon(Nylon 6I/6T) were carried out as a function of sorbate vapor activity at $23^{\circ}C$. Vapor activity levels from 0.035 to 0.91 were investigated to evaluate the concentration dependency of sorption mechanism. Sorption behavior of propanol by Nylon 6I/6T showed distinctive two mode sorption phenomena as a function of Vapor activity. At Vapor activity levels below a=0.11, equilibrium sorption was achieved within a short period of time(less than 20hrs), which can be interpreted as following a Fickian diffusion model. A Langmuir-Flory-Muggins Dual Mode Sorption model can also be applied at these concentration levels. However, for Vapor activities above a=0.11, the sorption process appeared to be non-Fickian and resulted in a lack of equilibrium being attained.

• YAKHAK HOEJI
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• v.59 no.2
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• pp.55-58
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• 2015

A series of N-substitutedaryl-3-phenylpropanamide derivatives were synthesized and their inhibitory activities on LPS-induced NF-$1{\kappa}B$ transcriptional activity on RAW 264.7 cells were evaluated. Cl substituted derivatives (1e, 1f) have shown more potent activities than parent hit compound KL-1156.