• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.359-360
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• 2002

A methodology was developed for evaluation of oxidation stability of base stocks and engine oils. Analytical procedures for both classes of lubricants were based on the ASTM standards D 6186 and/or E 2009. The procedures were applied to a set of engine oils of the SAE 5W-30 specification, and to a set of several hydrocracked and solvent neutral base oils, both with and without addition of antioxidant. A potential of a pressure DSC for diagnostic purposed was also demonstrated by monitoring the engine oil ageing during its operation in heavy-duty engine.

• 에너지공학
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• 제20권1호
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• pp.36-43
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• 2011

식물계 바이오매스는 석유로부터 얻어지는 화학물질들을 대체할 수 있는 물질로 제안되고 있다. 특히 식물계 바이오매스의 15-30%를 이루고 있는 리그닌은 복잡한 방향족 중합체로 이루어져 있어, 리그닌의 저분자화 공정에 의해 다양한 방향족 화합물을 얻을 수 있다. 본 연구에서는 국내에서 가장 많이 배출되는 크래프트 리그닌을 출발 물질로 선정하고, $^{13}C$-Muclear Magnetic Resonance($^{13}C$-NMR), Fourier Transform Infrared Spectroscopy (FT-IR), Elemental Analysis(EA)을 통해 원료물질의 화학적 구조를 분석하였다. 크래프트 리그닌의 저분자화 는 물-페놀 혼합 용매의 근임계 영역에서 수행되었으며, tube bomb reactor를 사용하였다. 최적의 반응조건을 찾기 위해 물-페놀의 비율, 반응온도($300-400^{\circ}C$)를 변화시키며 실험을 수행하였다. 또한 기체상 수소를 대신하여 수소발생 용매인 formic acid 사용에 따른 영향을 조사하였다. 액상 생성물의 화학 종류 및 양은 GC-MS를 통해 분석하였고, 고체 잔류물(char)은 FT-IR을 통해 분석하였다. GC-MS 분석 결과 페놀이 첨가된 경우 anisole, o-cresol(2-methylphenol), p-cresol(4-methylphenol), 2-ethylphenol, 4-ethylphenol, dibenzofuran, 3-methyl cabazole, xanthene이 생성되는 것을 확인하였다.

• 청정기술
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• 제22권4호
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• pp.250-257
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• 2016

As an attempt to replacing petroleum-based chemicals with bio-based ones, synthesis of furfural from biomass-derived xylose attracts much attention in recent days. Conventionally, furfural from xylose has been produced via the utilization of highly corrosive, toxic, and environmentally unfriendly mineral acids such as sulfuric acid or hydrochloric acid. In this study, microwave-assisted biphasic reaction process in the presence of novel bio-based heterogeneous acid catalysts was developed for the eco-benign and effective synthesis of furfural from xylose. The microwave was irradiated for reaction acceleration and a biphasic system consisting of $H_2O$ : MIBK (1 : 2) was designed for continuous extraction of furfural into the organic phase in order to reduce the undesired side products formed by decomposition/condensation/oligomerization in the acidic aqueous phase. Moreover, sulfonated amorphous carbonaceous materials were prepared from wood powder, the most abundant lignocellulosic biomass. The prepared catalysts were characterized by FT-IR, XPS, BET, elemental analysis and they were used as bio-based heterogeneous acid catalysts for the dehydration of xylose into furfural more effectively. For further optimization, the effect of temperature, reaction time, water/organic solvent ratio, and substrate/catalyst ratio on the xylose conversion and furfural yield were investigated and 100% conversion of xylose and 74% yield of furfural was achieved within 5 h at $180^{\circ}C$. The bio-based heterogeneous acid catalysts could be used three times without any significant loss of activity. This greener protocol provides highly selective conversion of xylose to furfural as well as facile isolation of product and bio-based heterogeneous acid catalysts can alternate the environmentally-burdened mineral acids.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.251.2-251.2
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• 2010

Plant biomass has been proposed to be an alternative source for petroleum-based chemical compounds. Especially, phenolic chemical compounds can be obtained from lignin by chemical depolymerization processes because lignin consists of complex aromatic polymer such as trans-p-coumaryl, coniferyl and sinapyl alcohols, etc. Phenolic chemical compounds from lignin were usually produced in super critical water. However, we applied Near-critical water (NCW) system because NCW is known as a good solvent for lignin depolymerization. Organic matter like lignin can be solved in NCW system and the system has a unique acid-base property without conventional non-eco-friendly chemicals such as sulfuric acid and sodium hydroxide. In this work, we tried to optimize the NCW depolymerization system by adjusting the processing variables such as reaction time, temperature and pressure. Moreover, the amount of additional phenol was optimized by changing the molar ratio between water and phenol. Phenol was used as capping agent to prevent re-polymerization of active fragment such as formaldehyde. Alkali-lignin was used as a starting material and characterized by a Solid State 13C-NMR, FT-IR and EA (Elemental Analysis). GC-MS analysis confirmed that o-cresol, p-cresol, anisole and 4-hydroxyphathalic acid were the main product and they were quantitatively analyzed by HPLC.

• 한국의상디자인학회지
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• 제21권4호
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• pp.213-220
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• 2019

The dry cleaning effect related to the type of soil and fiber was analyzed using silicone and alcohol-based solvents(ethyl alcohol, isopropyl alcohol, acetone) that are relatively safe for the human body and environment to improve the detergency of hydrophilic soils in dry cleaning system. Based on this analysis, an effective dry cleaning method to be carried out for improving the detergency according to the type of hydrophilic soils. After dry cleaning was performed using 20 types of artificial soiled fabrics consisting of 7 types of fibers and 4 types of hydrophilic soils, the detergency was measured and the results were compared and analyzed by solvents and fiber types. The results are presented as follows; first, the detergency of hydrophilic soils using silicone solvents showed a low rate of detergency. In particular, the tannin soil showed a lower level of detergency compared to the protein soil. Second, the detergency of hydrophilic soils using silicon solvents with dry soap differed in some detergency according to the soil and fiber types. Especially, the detergency of curry soil on cotton fabric showed significant improvement. Third, the protein soil was not removed from dry cleaning using alcohol-based solvents, but the effect of dry cleaning of curry soil on both cotton and polyester fabric was substantially improved. As a result, the elimination of blood soil is more effective in silicon solvents than in alcohol-based solvents. The removal of tannin soils may improve detergency by adding dry soap to silicon solvents or by using alcohol-based solvents as alternative solvents. The use of alternative solvents such as silicon and alcohol solvents can contribute to the environmental improvement of the dry cleaning industry, which uses petroleum-based solvents. It is also expected to provide consumers with the opportunity to choose eco-friendly and efficient dry cleaning methods.

• Journal of the Korean Wood Science and Technology
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• 제52권3호
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• pp.221-233
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• 2024

Lignin, a prominent constituent of woody biomass, is abundant in nature, cost-effective, and contains various functional groups, including hydroxyl groups. Owing to these characteristics, they have the potential to replace petroleum-based polyols in the polyurethane industry, offering a solution to environmental problems linked to resource depletion and CO₂ emissions. However, the structural complexity and low reactivity of lignin present challenges for its direct application in polyurethane materials. In this study, Kraft lignin (KL), a representative technical lignin, was fractionated with ethanol, an eco-friendly solvent, and mixed with conventional polyols in varying proportions to produce polyurethane films. The results of ethanol fractionation showed that the polydispersity of ethanol-soluble lignin (ESL) decreased from 3.71 to 2.72 and the hydroxyl content of ESL increased from 4.20 mmol/g to 5.49 mmol/g. Consequently, the polyurethane prepared by adding ESL was superior to the KL-based film, exhibiting improved miscibility with petrochemical-based polyols and reactivity with isocyanate groups. Consequently, the films using ESL as the polyol exhibited reduced shrinkage and a more uniform structure. Optical microscope and scanning electron microscope observations confirmed that lignin aggregation was lower in polyurethane with ESL than in that with KL. When the hydrophobicity of the samples was measured using the water contact angle, the addition of ESL resulted in higher hydrophobicity. In addition, as the amount of ESL added increased, an increase of 7.4% in the residual char was observed, and a 4.04% increase in Tmax the thermal stability of the produced polyurethane was effectively improved.

• 한국재난정보학회 논문집
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• 제16권4호
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• pp.701-711
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• 2020

연구목적: 본 연구에서는 두 물질의 혼합물(가연물+가연물)에서의 인화 위험성의 증가 또는 감소를 실험적으로 확인하고, 혼합물의 위험성을 제시하는 목적이 있기에 액체 혼합물의 인화 위험성을 실험적으로 확인하였다. 연구방법:인화점 실험방법 및 결과처리는 원유 및 석유 제품 인화점 시험 방법으로 사용되고 있는 테그밀폐식 시험방법인 KS M 2010-2008을 기준으로 실험하였다. 본 실험에 사용한 장비의 제조사는 일본의 TANAKA사에서 생산한 장비로 KS M 2010의 시험규격을 만족하는 시험장비로 인화점을 측정하였고, 점화원으로는 LP가스를, 냉각수로는 물을 사용하였다. 또한 인화점 측정시 냉각수의 온도는 약 2℃의 냉각수를 사용하여 실험을 진행하였다. 연구결과:실험결과로는 먼저 가연성+가연성 혼합물의 경우 두 물질의 인화점 차이가 크지 않으면 인화점의 변화가 거의 없었고, 두 물질의 인화점 차이가 낮으면 인화점이 높은 물질의 증가에 따라 인화점이 증가하는 경향을 보였으나, 톨루엔과 메탄올의 경우, 혼합물에서 인화점이 낮은 물질보다 더 낮은 인화점을 보였다. 또한 도료용 희석제의 경우, 혼합물로 이루어져서 그 물질의 인화점을 예상하기가 쉽지 않았지만 실험적으로 측정해 본 결과 -24℃~7℃사이로 측정되었다. 결론: 본 연구에서의 결과는 기존의 위험물안전관리법에서의 위험물 판정 기준에 대한 세부 내용의 실효성 확보 및 위험물 판정의 신뢰성 및 재현성 확보를 목적으로 인화성 혼합물에 대한 실험적 연구를 통해서 혼합물에 대한 위험성 판단 기준을 제시하였고, 향후 소방현장에서 단속되는 인화성 액체 대한 실험적 판정 기준에 대한 참고적인 자료를 제공할 수 있을 것이다. 또한 본 연구로 시험방법별 차이 실험에 대한 노하우를 축적한다면 위험물의 위험성 평가 연구에 있어 기초 자료이자 위험물 판정 관한 연구의 기반으로 활용될 수 있기를 기대한다.