• 해운
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• no.8 s.41
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• pp.10-14
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• 2007

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.7
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• pp.617-624
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• 2015

The dissolved air flotation (DAF) system is a water treatment process that removes contaminants by attaching micro bubbles to them, causing them to float to the water surface. In the present study, two-phase flow of air-water mixture is simulated to investigate changes in the internal flow analysis of DAF systems caused by using different turbulence models. Internal micro bubble distribution, velocity, and computation time are compared between several turbulence models for a given DAF geometry and condition. As a result, it is observed that the standard ${\kappa}-{\varepsilon}$ model, which has been frequently used in previous research, predicts somewhat different behavior than other turbulence models.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.1
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• pp.56-62
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• 2018

When it comes to treat patient with loss of vestibule, conventional denture impression have limitation which can cause problems of excessive border extension. Suction denture with closed mouth technique which was introduced to solve this problem, forms negative pressure being sealed denture flanges by mobile mucosa when the patient swallows and chews. Also, it can decrease patient's visiting time by taking impression and gothic arch tracing at once. In this case, considering patient's chief complain which is a loose fit of present lower denture, suction dentures with closed mouth technique was planned.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.3
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• pp.384-388
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• 2000

본 연구는 cocoa mass를 마이크로파 roasting하여 그 향기성분의 변화를 pyrazine류를 중심으로 살펴보는 한편 상법으로 roasting한 경우와 비교하고자 하였다. 마이크로파 roasting은 110,120,130,140,15$0^{\circ}C$의 온도에서 20분 및 30분 동안 행하였고 상법의 경우는 14$0^{\circ}C$에서 30분간 roasting하였다. Roasting한 시료를 연속수증기증류추출법으로 추출하고 농축한 후 GC와 GC/MS로 향기 성분을 분석하였다. 마이크로파 roasting의 경우 5분만에 14$0^{\circ}C$에 도달한 후 그 온도를 잘 유지하였으나, 상법의 경우 25분이 경과되어서야 14$0^{\circ}C$에 도달되었다. Roasting 한 시료의 향기성분으로 2,6-dimethyl pyrazine, 2,3,5-trimethyl pyrazine, 2,3,5,6-teramethyl pyrazine, 5-methyl fufural, 2-methyl-6-propyl pyrazine 등이 확인되었다. Roasting 온도가 증가함에 따라 dimethyl-, trimethyl-, tetramethyl pyrazine류가 증가하였고, tetramethyl pyrazine은 15$0^{\circ}C$ 20분 roasting의 경우 현저하게 증가하였으나, 30분 동안 roasting한 경우 14$0^{\circ}C$에서 증가하였다가 15$0^{\circ}C$일 때는 감소하였다. 그러나 적정 roasting 지표인 di/tri, di/tetra pyrazine의 비율은 1 이하를 보임으로써 마이크로파 roasting이 cocoa mass의 향기 발현에는 부족한 것으로 나타났다.

• Journal of Ginseng Research
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• v.12 no.2
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• pp.164-172
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• 1988

The solvent separation step in the conventional method for quantitative analysis of ginsenosides was substituted by purification through a small reverse-phase $C_18$-column resulting in the decrease of analysis time by one fourth. New method showed high recovery of total ginsenosides but low recovery in protopanaxatriol-ginsenosides. Sugars did not affect the recovery by the amount in usual root sample. Coefficient of variation in recovery of ginsenosides was lower in the rapid minicolumn method. Optimum load of ginsenosides to minicolumn was 10 to 15 mg. The rapid minicolumn method showed highly significant correlation with the solvent separation method for dried root and red ginseng. For the rapid minicolumn method a small acryl device was used for the simultaneous extraction of 8 samples. This method appeared to be beneficial in cost and for the health of analyst.

• Korean Journal of Food Science and Technology
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• v.41 no.5
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• pp.528-535
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• 2009

Three domestic varieties of red grapes were utilized for the fermentation of wines, including Campbell, Muscat Bailey A (MBA), and Sheridan. The grapes were treated by four different methods before fermentation, which included conventional fermentation for red wine, fermentation with skin-removed grapes, fermentation with grapes and addition of removed skins, and fermentation with grape juice. Three different grape varieties with four different treatments did not show any differences in terms of $^{\circ}Bx$ and alcohol changes during fermentation. However, the L value of the MBA wine was lower and darker than the L values of wines prepared from Campbell and Sheridan grapes. The wines prepared from grapes with the addition of removed skins were darker and had 30% higher polyphenol concentrations than those of wines made from grapes by the conventional method, regardless of the grape varieties. Sensory evaluations of dry-type wines demonstrated that quality was higher for those made from Campbell and MBA grapes with the addition of removed skins than for wines made by the conventional method. Whereas for sweet-type wines, the wine that was made from the skin-removed grapes (Sheridan) was more favorable than that made by the conventional method.

• Journal of radiological science and technology
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• v.14 no.1
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• pp.73-93
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• 1991

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2006.05a
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• pp.326-329
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• 2006

• The Journal of the Korean dental association
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• v.12 no.12
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• pp.893-895
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• 1974

• Proceedings of the Korea Water Resources Association Conference
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• 2001.05b
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• pp.1173-1176
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• 2001