• Journal of the East Asian Society of Dietary Life
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• v.18 no.5
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• pp.812-821
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• 2008

The characteristics of cold-pressed sesame oil (CPSO), virgin sesame oil (VSO), commercial heat-press extracted sesame oil (CHPESO) and commercial supercritical fluid extracted sesame oil (CSFESO) were investigated. The total phenolics of CPSO, VSO, CHPESO and CSFESO were 31.27, 68.33, 60.65 and 31.44 mg/100 g, respectively. Their $\gamma$-tocopherol contents were 32.82, 31.66, 29.26 and 26.87 mg/100g, respectively. The sesamol, sesamin, and sesamolin contents of VSO were the highest. The oxidation induction period (4.53 hr) of CPSO was lower than that of VSO, CHPESO and CSFESO (19.90, 16.50, and 12.23 hr, respectively). CPSO was rapidly oxidized during storage at $60^{\circ}C$ in the dark, and its peroxide value (POV) was increased about 14 times. Although there were few differences in electron-donating abilities at low concentrations (below 100 mg%), VSO showed the highest electron-donating abilities at higher concentrations (77.76% at 10,000 mg%). Contents of linolenic acid and oleic acid were $40.35{\sim}43.98$ and $31.59{\sim}33.46\;g$/100 g, respectively. CPSO contained the highest amount of oleic and linoleic acid among the variously extracted sesame oil.

• Journal of Marine Bioscience and Biotechnology
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• v.1 no.2
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• pp.105-118
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• 2006

Isolation and Identification of fatty acid and volatile compounds in tuna fish oil were successfully carried out using supercritical carbon dioxide. Samples of the oil were extracted in a 56 ml semi-batch stainless steel vessel under conditions which ranged from 80 to 200 bar and 40 to $60^{\circ}C$ with carbon dioxide flows from 10 ml/min. Volatiles in the oil extracted from the samples with supercritical carbon dioxide were analyzed by gas chromatography, mass detector with canister system. The extracts were contained with various fatty acids, 57.0% of unsaturated fatty acids such as docosahexaenoic acid(DHA) and eicosapentaenoic acid(EPA), and 43.0% of saturated fatty acids. The aroma compounds in the oil showed over 129 peaks, of which 100 compounds were identified. Volatile components included 2,4-hepatadienal(fishy), dimethyldisulfide (unpleasant), dimethyltrisulfide (unpleasant) and 2-nonenal(fatty). The isolation efficiency of the volatile compounds from the samples was 99.4% at $50^{\circ}C$ and 200 bar.

• Applied Chemistry for Engineering
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• v.21 no.2
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• pp.174-177
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• 2010

In this study, non-catalytic transesterification from rapeseed oil using supercritical methanol was carried out by varying the operation parameters such as temperature ($320{\sim}365{^{\circ}C}$), time (0~20 min), pressure (10~35 MPa), molar ratio of oil to methanol (1 : 15~60) and agitation speed (0~500 rpm). In order to evaluate the effects of reaction parameters on the content of fatty acid methyl esters (FAMEs), we carried out the study using a batch reactor. The content of FAMEs increased when the temperature increased. However, the content of FAMEs decreased with temperature above $335^{\circ}C$ and time above 5 min. The content of FAMEs increased with increasing the molar ratio of methanol to oil but the content of FAMEs was slightly affected by molar ratio of oil to methanol above 1 : 45 and pressure above 20 MPa. It was found that the agitation speed above 100 rpm slightly affected the content of FAMEs. The highest content of FAMEs in biodiesel (95%) was obtained under the reaction conditions: temperature of 335 ${^{\circ}C}$, time of 10 min, pressure of 20 MPa, molar ratio of 1 : 45 (oil to methanol) and agitation speed of 250 rpm.

• Korean Chemical Engineering Research
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• v.47 no.5
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• pp.651-654
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• 2009

In this study, non-catalytic transesterification using supercritical methanol was performed for preparation of biodiesel from palm oil. In order to investigate the effects of reaction parameters such as molar ratio of methanol to oil(30:1~60:1), pressure(8~25 MPa), temperature($320{\sim}350^{\circ}C$), agitation speed(0~1,000 rpm) and time(0~20 min) on the content of fatty acid methyl esters(FAMEs), we carried out the study using a batch reactor. With increasing molar ratio of methanol to oil, the content of FAMEs increased. However, the content of FAMEs was little affected by molar ratio above 45 and pressure above 20 MPa. The content of FAMEs increased when the temperature increased. However, the content of FAMEs decreased with temperature above at $350^{\circ}C$ and with time above 5 min. It was found that the agitation speed above 500 rpm scarcely affected the content of FAMEs. The highest content of FAMEs in biodiesel(95%) was obtained under the reaction conditions: temperature of $335^{\circ}C$, pressure of 20 MPa, molar ratio of 45:1(methanol to palm oil), agitation speed of 500 rpm and time of 10 min.

• Journal of the Korean Vacuum Society
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• v.16 no.2
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• pp.153-159
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• 2007

In-cryostat helium lines are under installation to transfer a cryogenic helium into cold components in KSTAR device. In KSTAR, three kinds of helium should be supplied into the cold components, which are supercritical helium Into superconduction(SC) magnet system, liquid helium into current lead system, and gas helium into thermal shields. Cryogenic helium lines consist of transfer lines outside the cryostat, in-cryostat helium lines, and electrical breaks. In-cryostat helium lines should be guaranteed of leak tightness for tong time operation at high internal helium pressure of 20 bar. We wrapped the helium line with multi-layer insulator(MLI) to reduce radiation heat and insulated the surface of the high potential part with prepreg tape. The electrical break was fabricated by brazing ceramic tube with stainless steel tube. To ensure the operation reliability at operation temperature, all the electrical break have been examined by the thermal cycle test at liquid nitrogen and by the hydraulic test at 30 bar. And additional surface insulation was prepared with prepreg tape to give structural safety. At present most of the in-cryostat helium lines have been installed and the final inspection test is progressing.

• Journal of Applied Biological Chemistry
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• v.61 no.1
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• pp.47-50
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• 2018

Ricania shantungensis is a pest causiong problems in many crops. We tested the possibility of controling Ricania shantungensis using essential oil of Valeriana fauriei which were extracted by three different methods (steam distillation, solvent and supercritical extraction). Steam distillation were showed the most high mortality to adult ($1,040{\mu}L/mL$) and nymph ($2,370{\mu}L/mL$) of R. shantungensis. The yield of steam distillation extraction was 0.67%, which was lower than other methods. However, it is determined that steam extraction was showed higher efficiency by considering time and cost. The result of this study showed the possibility of control R. shantungensis by essential oil of V. fauriei.

• Journal of the Korean Wood Science and Technology
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• v.43 no.3
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• pp.355-363
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• 2015

Asian lignin was efficiently depolymerized with supercritical ethanol and Ru/C catalyst at various reaction temperature (250, 300, and $350^{\circ}C$). Lignin-oil was subjected to several physicochemical analyses such as GC/MS, GPC, and elemental analysis. With increasing reaction temperature, the yield of lignin-oil decreased from 89.5 wt% to 32.1 wt%. The average molecular weight (Mw) and polydispersity index (Mw/Mn) of lignin-oil obtained from $350^{\circ}C$ (547Da, 1.49) dramatically decreased compare to those of original asian lignin (3698Da, 2.68). This is a clear evidence of lignin depolymerization. GC/MS analysis revealed that the yield of monomeric phenols involving guaiacol, 4-ethyl-phenol, 4-methylguaiacol, syringol, and 4-methysyringol increased with increasing reaction temperature, and these were mostly produced with applying hydrogen gas and Ru/C catalyst (76.1 mg/g of lignin). Meanwhile, the carbon content of lignin-oil increased whereas the oxygen content decreased with increasing reaction temperature, suggesting that hydrodeoxygenation was significantly enhanced at higher temperature.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1104-1109
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• 2003

Response surface methodology (RSM) was used to investigate the effects of the processing parameters on supercritical $CO_2\;(SC-CO_2)$. extraction of total carotenoids and ${\beta}$-cyptoxanthin from Citrus unshiu press cake. The parameters tested were $SC-CO_2$ pressure, dynamic extraction time, and concentration of ethanol added as the modifier to $CO_2$. Experimental data correlated well with the processing parameters (p<0.01), and there was a high statistically significant multiple regression relationship for the extraction of total carotenoids and ${\beta}-cyrptoxanthin$ ($R^2=0.9789$ and 0.9796, respectively). The optimal processing conditions were extraction pressure 33.4 and 37.3 MPa, extraction time 39.6 and 41.0 min, ethanol concentration 18.6 and 17.0% for total carotenoids and ${\beta}-cryptozanthin$, respectively. Maximum extraction yields predicted by RSM were 61.1 and 95.8% ppm, respectively. The extraction yield of total carotenoids increased asymptotically with the increase of the extraction pressure. It increased in proportion to extraction time and concentration of the cosolvent. The extraction yield of ${\beta}-cryptoxanthin$ increased with extraction pressure, extraction time, and concentration of the cosolvent. The extraction time and the concentration of the cosolvent, and the interaction between extraction time and the concentration of the cosolvent significantly affected the extraction yields of carotenoids from C. unshiu press cake.

• Economic and Environmental Geology
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• v.51 no.3
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• pp.223-232
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• 2018

The viscous force of fluids and the capillary force acting on the pore network of the porous media are important factors determining the immiscible displacement during geological $CO_2$ sequestration, these were directly affected by geological formation conditions and injection conditions. This study aimed to observe the migration and distribution of injected fluid and pore water, and quantitatively investigate displacement efficiency on various injection temperatures. This study aimed to perform micromodel experiments by applying n-hexane used as a proxy fluid for supercritical $CO_2$. In this study, immiscible displacement process from beginning of n-hexane injection to equilibrium of the distribution of the n-hexane and pore water was observed. The images from experiment were used to observe the displacement pattern and estimate the areal displacment efficiency of the n-hexane. For investigate the affects of the injection temperatures on the migration in macroscopic, migration of n-hexane in single pore was analyzed. The measurement revealed that the displacement efficiency at equilibrium state decreases as the temperature increases. The result from experiments indicate that the temperatures can affect the displacement pattern by changing the viscous forces and the capillary forces. The experimental results could provide important fundamental information on reservoir conditions and fluid injection conditions during geological $CO_2$ sequestration.

• Applied Chemistry for Engineering
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• v.18 no.6
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• pp.643-649
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• 2007

Lipase-catalyzed esterification of structural butanol isomers and n-butyric acid was investigated in supercritical carbon dioxide. The experiments were performed in a high pressure cell for 5 hrs with a stirring rate of 150 rpm at 323.15 K and 130 bar. The Candida Antarctica lipase B (CALB) was used in whole system as a catalyst. The experimental results were analyzed by GC-FID using a INNOWax capillary column. The conversion yield and the tendency of the esterification in supercritical carbon dioxide were compared with estimated results by molecular dynamics simulation. Based on the Ping-Pong Bi-Bi mechanism with competitive inhibition, each step of the reaction was optimized; using this result the transition state was predicted. Conformational preference of isomers was also analyzed using molecular dynamics simulations. This kind of approach will be further extended to the prediction of enzyme-catalyzed reactions using computers.