• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1996년도 춘계학술발표회 논문집
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• pp.217-219
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• 1996

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1996년도 추계 학술발표회
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• pp.534-538
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• 1996

• 미생물학회지
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• 제24권3호
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• pp.323-328
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• 1986

To clarify the effects of several carbohydrates on the biodegradation of lignin by Pleurotus ostreatus. The strain was cultured on the media formulated with lignin and carbohydrates such as cellulose, xylan, collobiose, glucose and xylose, which was added individually. The culture mixtures grown 36 days were filtered and then estimated the degree of lignin biodegradation. It was found that the growth of P. ostreatus was stimulated and the depoly-merization was also increased by the addition of carbohydrates. When the carbohydrates were not added, polymerization was apparent in stead of depolymerization. In the case of glucose as an added carbohydrate, the content of lignin by the nitrosolignin method was greatly (about 7.4 times) decreased than control which contains lignin as a carbon source. The peak of lignin at 280nm in UV spectra was decreased about 27% after 27 days of culture. As results, it was assumed that lignin biodegradation was correlated to the carbohydrates and especially glucose was very significant role in lignin degradation.

• 한국전기전자재료학회논문지
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• 제11권6호
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• pp.481-485
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• 1998

We investigated the generation of high pretilt angle for nematic liquid crystal (NLC) in a cell with obilique non-polarized ultraviolet (UV) light irradiation on mixtured polyimide surface. It was found that the monodomain alignment of NLC is obtained with an angle of incidence of 75∼85 degrees on PI surface. We consider that the monodomain alignment of NLC is attributed to anisotropic dispersion force effect to photo-depolymerization of polymer. We successfully observed that the pretilt angle of NLC is generated above 5 degree with an angle of incidence of 75∼85 degrees. It is considered that the pretilt angle generation NLC is attributed to interaction between the LC molecules and the polymer surfaces.

• 펄프종이기술
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• 제29권4호
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• pp.64-72
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• 1997

백색부후균에 의한 리그닌의 분해양상을 검토하기 위해 리그닌 분해능이 우수하고 laccase활성이 높은 LKY-7 및 C. versicolor-13 균주와 manganese peroxidase 활성은 비교적 높으나 laccase활성이 전혀 나타나지 않는 LSK-27 균주로 lignosulfonate를 처리하였다. LKY-7 과 C. versicolor-13 균주에서는 lignosulfonate의 중합화 현상이 관찰되었으며 중합화는 laccase 활성 과 비례하는 것으로 나타났다. LSK-27 균주에서는 lignosulfonate의 고분자 영역이 분해되면서 탈중합화가 일어났으며 리그닌 분해 효소로는 manganese peroxidase만 검출되었다. 보조기질로 glucose를 첨가한 결과, LKY-7 균주에서는 laccase 활정이 각소하면서 중합화 현상이 어느 정도 감소하였으나 C. versicolor-13 균주는 laccase 활성의 증가와 함께 중합화도 촉진되는 것으로 나타났다. 또한 LSK-27 균주에서도 glucose 첨가에 의해 manganese peroxidase 활성이 증가되면서 lignosulfonate의 중합화가 관찰되었다. lignosulfonate 중합화에는 laccase 뿐만 아니라 manganese peroxidase도 관여하며 보조기질로서 탄소원의 종류도 영향을 미칠것으로 검토되었다.

• Archives of Pharmacal Research
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• 제17권3호
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• pp.199-203
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• 1994

Several lines evidence indicate that microtubule depolymerization initiates DNA synthesis or enhances the effects of serum or purified growth factors in many types of fibroblasts. Yet little is known about the intracellular events responsible for the mitogenic effect of microtubule disrupting agents. The effects of antitubulin agents on DNA synthesis in sparse and dense cultures in the presence or absence of serum and possible involvement of G-proteins in their mitotic action were examined. In these studies, colchicine by itself appeared to be mitogenic only for confluent quiesecent human lung fibroblasts. In sparse culture, however, colchicine inhibited serum-stimulated DNA synthesis. Colcemid, another antitubulin agent, showed similar effects of growth inhibition and stimulation in sparse and confluent cultures while lumicolhicine, inactive colchicine, did not. The mitogenic effect of two antitubulin agents, colchicine and colcemid, was partially inhibited by pertussis toxin. These data suggest that microtubular integrity is associated with the expression of either negative or positive control on DNA synthesis and mitogenic effect of antitubulin agents may be partially mediated by pertussis toxin-sensitive G protein.

• 한국식품영양과학회지
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• 제26권6호
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• pp.1122-1127
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• 1997

Melanoidins, which were higher polymers with intense brown color, were investigated on their decolorization and degradation by ozonolysis. Amino acids linked up with melanoidins were readily separated by depolymerization of melanoidins with ozonolysis. The IR spectra of ozone-untreated MRPs showed a higher peak at $1665cm^{-1}$ (C=N) and $1600cm^{-1}$ (C=C) than the corresponding peaks of ozone-treated MRPs. Ozone-treated melanoidins with molecular weight of above 900 showed the highest nitrogen composition of all melanoidins tested. Ozone-treated melanoidins with molecular weight of 900 to 1000 were separated into five peaks on recycling preparative HPLC chromatogram. Major functional groups in ozone-treated melanoidins with molecular weight of 900 to 1, 000 were -CH$_2$-CO-, -CH$_2$-O- and CH$_2$-.

• Korean Journal of Chemical Engineering
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• 제35권11호
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• pp.2303-2312
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• 2018

Pretreatment process of silica-coated PET fabrics, a major low-grade PET waste, was developed using the reaction with NaOH solution. By destroying the structure of silica coating layer, impurities such as silica and pigment dyes could be removed. The removal of impurity was confirmed by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX). The pretreated PET fabric samples were used for depolymerization into its monomer, bis(2-hydroxylethyl) terephthalate (BHET), by glycolysis with ethylene glycol (EG), and zinc acetate (ZnAc) catalyst. The quality of BHET was confirmed by DSC, TGA, HPLC and NMR analyses. The highest BHET yield of 89.23% was obtained from pretreated PET fabrics, while glycolysis with raw PET fabric yielded 85.43%. The BHET yield from untreated silica-coated PET fabrics was 60.39%. The pretreatment process enhances the monomer yield by the removal of impurity and also improves the quality of the monomer.

• 청정기술
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• 제13권4호
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• pp.251-256
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• 2007

폴리카보네이트(PC)의 해중합 방법에는 여러 가지방법이 보고되어 있으나, 기존의 해중합 방범에는 페놀, 톨루엔, 다이옥신 등의 독성물질 사용으로 인한 환경적인 안전문제, 알칼리의 사용으로 인한 2차 분리 문제 등이 있다. 따라서 본 연구에서는 독성물질 및 촉매를 사용하지 않고 에틸렌글리콜(EG)과 메탄올(MeOH)을 사용한 글리콜첨가분해(glycolysis)/메탄올첨가분해(methanolysis) 혼성공정에 의하여 폐PC로부터 비스페놀 A (BPA)를 회수하였다. 글리콜첨가분해는 반응온도 473.15K에서 180분에 반응평형에 도달하였고, PC의 용해과정이 이 반응의 율속단계로 나타났다. 글리콜첨가분해 이후 메탄올첨가분해를 시행함으로써 BPA수율을 높일 수 있었으며, HeOH/PC 몰비 1에서 BPA수율은 최대점을 가지고, 반응 온도가 증가할수록 수율이 증가하였다.

• 한국식품과학회지
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• 제43권3호
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• pp.321-328
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• 2011

본 연구에서는 대추를 필름 형태의 식품 소재로 개발하였다. 대추 필름 제작에 고분자 분쇄 방법으로 사용된 HPH는 대추 필름의 인장 강도와 수분 투과도를 향상시켰다. 기존에 개발된 많은 다른 생고분자 필름보다 높은 인장 강도와 낮은 수분 투과도는 열접합강도와 함께 식품에 있어 HPH 대추 필름의 상업적 적용 가능성을 보여주었다. 대추 필름은 대추 고유의 형태와 크기에 제한 없이 여러 식품에 코팅 또는 롤 형태로 사용될 수 있을 것으로 기대된다.