• Food Science and Biotechnology
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• 제17권3호
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• pp.470-474
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• 2008

The whole berry, pulp, and seed of sea buckthorn fruit were extracted with supercritical $CO_2$ to produce edible oils. The effects of extraction pressure, temperature, and $CO_2$ flow rate on the oil yield and extraction rate were investigated, and the fatty acid composition, tocopherol, and carotenoid contents of the oils were compared. The results showed that the extraction rate was affected by pressure, temperature, and $CO_2$ flow rate and, in general, the yield increased with a rise in any of the 3 variables. Fatty acids in the whole berry and pulp oil were dominated by monounsaturated fatty acids (>64%), followed by saturated fatty acids (about 30%). In contrast, fatty acids in the seed oil consisted mainly of polyunsaturated (>60%) and monounsaturated fatty acids (>24%). The seed oil had a slightly higher content of tocopherols, but a much lower content of carotenoids, compared with the whole berry or pulp oil.

• 동아시아식생활학회지
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• 제4권3호
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• pp.97-102
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• 1994

The oxidative stability of perilla oil were examined by measuring peroxide value. The induction period of perilla oil for each storage temperature was measured by POV and indicated that it was 80 days for 45$^{\circ}C$, 22.5 days for 65$^{\circ}C$, 9.5 days for 85$^{\circ}C$ and 5 days for 105$^{\circ}C$ respectively. Also, the induction period of the perilla oil with different concentration of ginger powder at 85$^{\circ}C$was studied and has been found that 9.4 days for 6% ginger powder, 11.9 days for 4% and 11days for 2% ginger power. The relative antioxidant effectiveness of ginger power was 99% for 6% ginger power, 125% for 4% ginger power, 122% for 2% ginger power. The induction period of perilla oil with gingerol at 85$^{\circ}C$ was 13.5days for 2% crude gingerol, 11.7days for 0.2% crude gingerol and 12.0 days for 0.02% BHT. The elativi antroxidant effectiveness of perilla oil gingerol at 85$^{\circ}C$was 142% for 2% crude gingerol, 123% for 0.2% crude gingerol, 126% for 0.02% BHT.

• 한국환경과학회지
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• 제18권2호
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• pp.231-238
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• 2009

Characteristics of the transesterification reaction between triglycerides in soy bean oil and methanol were investigated in the presence of acid catalysts. such as sulfuric acid and PTS (p-toluene sulfonic acid). Concentrations of diglyceride and monoglyceride which were intermediates in the reaction mixtures, were far below 10% of triglyceride under any reaction conditions. Thus, conversion of the reaction could be determined from the concentration of triglyceride. Dried PTS had more superior catalytic power than sulfuric acid for transesterification reaction between soy bean oil and methanol. When transesterification reaction of soy bean oil was catalyzed by 1 wt% of PTS at methanol stoichiometric mole ratio of 2 and $65^{\circ}C$, final conversion reached 95% within 48 hours. If FAME (fatty acid methyl ester) was added into reaction mixture of soy bean oil, methanol and PTS catalyst, it converted reaction mixture into homogeneous phase, and substantially increased reaction rate. When reaction mixture was freely boiling which had equal volumetric amount of FAME to soy bean oil, methanol stoichiometric mole ratio of 2 and 1 wt% of PTS, final conversion achieved value of 94% and temperature approached to $110^{\circ}C$ within 2 hours.

• Transactions on Electrical and Electronic Materials
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• 제11권6호
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• pp.288-291
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• 2010

Accidents can occur as a result of streaming electrification when transformer oil is used as an insulating oil in large ultra-high voltage transformers. Methods for adding a streaming electrification inhibitor to reduce the streaming electrification has been studied extensively. In this paper, in order to develop a method for reducing streaming electrification effectively, 4 different specimens were prepared by the addition of benzotriazole (BTA) to a virgin specimen with constant stirring. The specimens were examined to determine the appropriate amount of BTA addition that would suppress the streaming electrification most effectively. The results showed that the streaming electrification characteristics of the specimen in the streaming transformer oil were best when the amount of BTA addition was about 10 ppm. The streaming electrification current was reduced by adding 30 ppm BTA until the temperature reached $65^{\circ}C$. The polarity of the streaming electrification current was negative when the temperature exceeded $65^{\circ}C$. Therefore, the streaming electrification current, which can be a cause of transformer accidents, can be suppressed in large ultra high voltage transformer oil. This paper reports on the optimal amount of BTA addition and the best conditions for controlling the streaming velocity of transformer oil.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.321-324
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• 2009

Upgrading of pyrolysis wax oil has been conducted in a continuous fixed bed reactor at $450^{\circ}C$, 1hour, LHSV 3.5/h. The catalytic degradation using HZSM-5 catalyst are compared with the thermal degradation and also was studied with a function of experimental variables. The raw pyrolysis wax oil shows relatively high boiling point distribution ranging from around $300^{\circ}C$ to $550^{\circ}C$, which has considerably higher boiling point distribution than that of commercial diesel. The product characteristic from thermal degradation shows a similar trend with that of raw pyrolysis wax oil. This means the thermal degradation of pyrolysis wax oil at high degradation temperature is not sufficiently occurred. On the other hand, the catalytic degradation using HZSM-5 catalyst relative to the thermal degradation shows the high conversion of pyrolysis wax oil to light hydrocarbons. This liquid product shows high gasoline range fraction as around 90% fraction and considerably high aromatic fraction in liquid product. Also, in the catalytic degradation the experimental variable such as catalyst amount and reaction temperature was studied.

• Food Science and Biotechnology
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• 제18권1호
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• pp.79-83
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• 2009

Acidolysis of olive oil with omega-3 (n-3) polyunsaturated fatty acids (PUFAs) was carried out to produce a structured lipid. Novozym $435^{(R)}$ from Candida antarctica was used as the biocatalyst. Response surface methodology (RSM) was used to determine optimum conditions for lipase-catalyzed enrichment of olive oil. Three factors, 5 levels, central composite design was used. The effects of incubation time, temperature, and substrate mole ratio on incorporation ratio (n-3 fatty acids/total fatty acids, %) were investigated. From the evaluation of response surface graphs, the optimal conditions for incorporation of long chain n-3 PUFAs into olive oil were $40-60^{\circ}C$ for temperature, 30-45 hr for reaction time, and 3:1-5:1 (n-3 fatty acids/olive oil) for substrate mole ratio. Experiments conducted under optimized conditions predicted by the model equation obtained from RSM yielded structured lipids with 50.8% n-3 PUFAs. This value agreed well with that predicted by the model. Oxidative stability tests showed that the product was more susceptible to oxidation than unmodified olive oil. Antioxidant addition improved the oxidative stability of the product.

• 한국염색가공학회지
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• 제24권4호
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• pp.313-320
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• 2012

For the preparation of hardened films which can be applied as a binder for flame-resistant materials such as silica, linseed oil was subjected to a low temperature plasma treatment with argon, or oxygen gas. The film was produced much faster than so-called drying of oil in air. The SEM analysis for silica particles embedded in the hardened film after plasma treatment showed that the silica particles were immobilized on substrate and were evenly dispersed. The FT-IR spectral analysis for the plasma-treated linseed oil films demonstrated that the radicals which were formed during the plasma treatments caused the linseed oil to be cross-linked, and the plasmas attacked carbon chains of the oil randomly without focusing on specific vulnerable bonds such carbon double and carbonyl bonds intensively unless exposure times of the plasmas were prolonged too much, while the cross-linking of the air-dried film was considered to occur at the well-known typical sites, i.e., carbon-carbon double bond and ${\alpha}$-methylene carbon. Burning times, as a measure of flame/fire resistance, of silica-filled cellulose substrates, increased with increasing contents of silica.

• 한국자동차공학회논문집
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• 제24권1호
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• pp.90-98
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• 2016

Currently government certified test method for an automobile remanufactured products is insufficient. Thus many automotive parts in the remanufacturing market are lacking proper evaluation criteria and production of defective products are causing customer dissatisfaction. In this paper a power steering oil pump, which requires stringent manufacturing standards, is studied by the failure mode and effect analysis approach. The research suggested that the test criteria such as discharge flow characteristic test, tightness test, pulley run-out test, pressure switch operation test, low temperature test and rotation pressure durability test should be performed to evaluate the reliability of remanufactured power steering oil pumps. As a result of tests, the performance of remanufactured power steering oil pump satisfied the evaluation criteria of pressure switch operation test and low temperature test. However, the remanufactured power steering oil pump failed to satisfy the evaluation criteria on discharge performance test, tightness test and pulley run-out test. These performance evaluation tests proved the necessity of standard process for the remanufactured power steering oil pump.

• 한국식품과학회지
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• 제30권1호
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• pp.77-81
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• 1998

쌀눈 및 쌀겨에 함유된 유지를 추출, 온도별 저장 안정성과 지방산조성을 비교하였다. 쌀눈 및 쌀겨유지를 $40^{\circ}C$ 및 $60^{\circ}C$에 31일간 저장 중 유지의 산가는 큰 차이가 없었고 과산화물가는 저장 온도가 높아짐에 따라 크게 상승하였는데, $40^{\circ}C$저장 31일에는 건조처리한 쌀눈의 유지가 가장 높아 146.2 meq/kg이었고 정제유는 15.1 meq/kg 이었으며, $60^{\circ}C$저장 24일에는 정제유는 219.6 meq/kg, 건조쌀눈유지는 151.7meq/kg 이었다. 쌀눈과 쌀겨유지 중 주 지방산은 쌀눈은 linoleic acid (39.0%)와 oleic acid (34.7%)이었고 쌀겨는 oleic acid (40.1%)와 linoleic acid (38.1%)였으며, 저장 중 주 지방산의 조성은 쌀눈의 건조처리나 저장온도에 큰 영향을 받지 않았으나 linolenic acid의 함량은 모든 처리에서 감소하는 경향이었다.

• 대한토목학회논문집
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• 제44권3호
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• pp.271-276
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• 2024

고갈되고 있는 자원인 전통 석유는 전세계 석유매장량의 3분의 1에 불과하여 비전통 오일을 자원으로 활용하고자 하는 연구와 사례가 지속적으로 증가하고 있다. 하지만 비전통 오일에는 모래와 같은 고체입자가 포함된 역청이 함유되어 있으며 고온 고압의 환경에 노출되기 때문에 송유관에 변형이 빈번히 발생할 수 있다. 따라서 송유관의 변형에 영향을 끼칠 수 있는 재료, 두께, 각도 등의 변수를 도출하여 송유관에 적용하고 Ansys 프로그램을 통해 유한요소해석을 진행하였다. 유한요소해석의 결과로 변형, 최대하중 용량을 도출하였다. 이후 변형 저항과 최대하중 용량이 가장 우수한 인자를 조합하여 최적화된 송유관을 모델링하여 동일한 해석을 진행하였다. 해석 결과 변형을 감소시키며 30 % 가량 최대하중 용량을 증진시키는 효과를 확인하였고 송유관 해석 시 변형억제를 위한 인자들을 도출하였다.