• Applied Biological Chemistry
• /
• v.42 no.3
• /
• pp.205-209
• /
• 1999

Cholesterol plays an important role in various physiological responses and membrane stability. To investigate the effect of cholesterol in liposome on the stability of encapsulated ascorbic acid, the physico-chemical experiments using various amounts of cholesterol-containing liposomes were performed. The encapsulation efficiency of ascorbic acid was decreased with increasing cholesterol content in liposome, whereas size of liposome was increased. Furthermore, the stability of encapsulated ascorbic acid was increased with increasing the content of cholesterol. The stability was not affected by pH. Encapsulated ascorbic acid in liposome stored at $37^{\circ}C$ was rapidly oxidized compared to those stored at $4^{\circ}C$. These results suggest that cholesterol in liposome affects largely to the stability of encapsulated ascorbic acid.

• Applied Biological Chemistry
• /
• v.37 no.3
• /
• pp.168-174
• /
• 1994

Effects of filtration and centrifugation on the oxidative stabilities of sesame oils during storage at $70^{\circ}C$ were studied by combination of determining peroxide values and conjugated dienoic acid values of oils and measuring the hexanal formation using headspace gas chromatography. Crude sesame oil from roasted seeds contained more free fatty acids, conjugated dienes, and metals (Fe, Cu, Mg and Zn); on the other hand, higher contents of moisture and ${\gamma}-tocopherol$ were found in the filtered or centrifuged oil. Only filtered oil contained more peroxides than the crude oil in spite of the color advantage of the highest L and b values among three oils. All the oils showed the tendency of increasing in total color difference during storage at $70^{\circ}C$, fatty acid compositions were relatively constant except for decreasing tendency of linoleic acid in filtered oil. No significant difference at 1% in the oxidative stabilities was observed between centrifuged oil and crude oil with higher susceptibility to the oxidation in the filtered oil. Centrifuged sesame oil was the best in the aspect of both oxidative stability and the oil color.

• Tunnel and Underground Space
• /
• v.20 no.6
• /
• pp.446-454
• /
• 2010

CAES-G/T (Compressed Air Energy Storage - Gas Turbine) power generation is a likely option for the buffer facility stabilizing the fluctuation of the renewable powers, such as wind and solar powers. Considering the geological conditions, the underground CAES facility is most probable if the CAES-G/T generation is planed in Korea. In this kind of facility, a concrete plug is installed to seal the compressed air in the container, so that the selection of the shape and dimension of concrete plug could be a critical design factor. The stability evaluation of two types of plug was carried out by investigating the distribution of the factor of safety in the plugs and the distribution of contact pressure over the contact surface. The analysis result shows that the taper-shaped plug is more structurally stable than the wedge-shaped plug for the given geological condition. Possible separation of the rock-concrete interface around the spring line of the wedge-shaped plug is anticipated, which means the possible leakage of compressed air through the side wall and also means the poor mobilization of frictional resistance on that area.

• Korean Journal of Food Science and Technology
• /
• v.26 no.5
• /
• pp.520-525
• /
• 1994

This study was carried on the garlic-seasoning oil production by autoclaving method and evaporating method in order to research a developed method. The raw, flake, extract states of garlic was added 40%(w/w) of total amounts to corn salad oil. All samples treated with various conditions analyzed the volatile flavor components(VFC) during incubating ($40{\pm}2^{\circ}C$) and heating ($185{\pm}2^{\circ}C$). In the garlicseasoning oils, the contents of propane, pentane, methyl allyl trisulfide and diallyl trisulfide as the major VFC were decreased while the contents of propenal and hexanal increased according to the storage and heat treatment. The order of flavor contents among garlic states were raw>extract>flake, but flavor stability were raw>flake>extract states during storage, while flake>raw>extract states in heat treatment. VFC in garlic-seasoning oil made by evaporating method were about 66.1% level of those made by autoclaving method, but the changing tendency of their content during storage and heat treatment were shown to be similar. According to those results, autoclaving method and evaporating method were thought to the rational method in preparation of garlic-seasoning oil.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.38 no.7
• /
• pp.885-891
• /
• 2009

To examine stability of a violet red pigment in a Salicornia herbacea L., several tests for pH, sugar, organic acid, ascorbic acid, amino acid, salt and temperature effect were carried out. A violet red pigment in Salicornia herbacea L. was the most stable in the range of pH 4 to 6. Each of the violet red pigments in Salicornia herbacea L. added with different amounts of sugar showed higher retention rate according to storage time than those of the control group. After 10 days of storage, especially the retention rate of the experimentals with 0.5 M sucrose was higher than the controls by about 11.1% while fructose, maltose, glucose and galactose were less higher in order. Also, adding organic acid reduced retention rate of the experimentals over the controls irrespective of sort and concentration of organic acid; also, the retention rate of the experiment with 0.5 M organic acid, the highest amount of all, reduced radically to 13.1 to 15.9% after 10 days storage. The retention rate of the experimentals added 1,000 ppm ascorbic acid and thio urea respectively after 10 days was 48.4%, which is higher than the controls by around 23.1%. As to amino acid, treatment on the pigment with aspartic acid 50 mM marked the highest retention rate of 41.5% and treatment with 2.0 M NaCl showed 31.6% retention rate, which was higher than the controls. While low temperature like $5^{\circ}C$ and $25^{\circ}C$ kept the stability of the pigment in storage, as temperature increased the stability of the pigment dropped rapidly.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.13 no.2
• /
• pp.121-125
• /
• 2010

Carbon Capture and Storage (CCS) technology mitigates the emission amount of carbon dioxide into the atmosphere and can reduce green house effect which causes the climate change. Deep saline aquifer or obsolete oil/gas storage etc. in the marine geological structure are considered as the candidates for the storage. The injection and storage relating technology have been interested in the global society, however the adverse effect caused by leakage from the system failure. Even the safety level of the CCS is very high and there is almost no possibility to leak but, still the risk to marine ecosystem of the high concentrated carbon dioxide exposure is not verified. The present study introduces the system and environmental risk assessment methods. The feature, event and process approach can be a good starting point and we found the some possibility from the fault tree analysis for evaluation. From the FEP analysis, we drove the possible scenario which we need to concentrate on the construction and operation stages.

• Tunnel and Underground Space
• /
• v.18 no.3
• /
• pp.175-184
• /
• 2008

In this study, state-of-the-art of $CO_2$ geological sequestration as a method of greenhouse gas reduction was reviewed. Thermal-Hydraulic-Mechanically(THM) coupled simulation technology and its application to a stability analysis of geological formation due to $CO_2$ injection as well as a leakage path analysis were investigated and introduced.

• Proceedings of the Optical Society of Korea Conference
• /
• 2003.02a
• /
• pp.76-77
• /
• 2003

차세대 정보저장 기술중의 하나인 홀로그래픽 데이터 저장 기술은 빠른 데이터 접근속도와 기록 매질의 동일 위치에 수 천 페이지의 광정보를 중첩 기록할 수 있기 때문에 높은 저장용량을 갖는다. 이러한 홀로그래픽 데이터 저장을 위한 주요 구성으로 SLM(spatial light modulation)과 홀로그래픽 기록 매질을 들 수 있다. SLM은 전기적 신호를 광신호로 변조하기 위한 입력장치로 사용되며, 홀로그래픽 시스템에 사용되는 기록 매질은 고감도, 간단한 실시간 처리, 고회절효율, 기록 후 긴 안정성이 요구된다. (중략)

• Proceedings of the Korean Information Science Society Conference
• /
• 2001.04a
• /
• pp.124-126
• /
• 2001

본 논문은 Tertiary 저장장치에 기반한 대용량 비디오 서버를 위한 스테이징 스케쥴링의 설계와 구현에 대해서 기술한다. 많은 저장 공간을 제공하지만 입출력 대역폭이 낮은 Tertiary 저장장치를 효과적으로 활용하기 위하여 Tertiary 저장장치에서 디스크 캐쉬로의 스테이징 작업을 위한 효과적인 스케쥴링 방법이 필요하다. 스테이징 스케쥴링은 주기 모델을 적용하며 서비스의 안정성을 위해 위급도가 높은 스테이징 작업이 먼저 수행될 수 있도록 EDF 방법에 의해 작업의 순서를 결정한다. 서비스 중인 비디오의 요구 스테이징 대역폭을 정형화된 몇 개의 패턴에 대응시켜 스테이징 작업의 예측이 가능하도록 하며 여유 스테이징 대역폭의 효과적인 관리가 가능하도록 한다. 또한 스테이징 압축 기법을 사용하여 스테이징 대역폭을 최대한 활용한다. 제시된 스테이징 스케쥴링 기법을 실제 구현된 서버의 성능 분석을 통해 검증한다.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
• /
• 2003.04a
• /
• pp.99.2-99
• /
• 2003

미강은 미곡처리장에서 발생하는 도정부산물이지만 비타민 E, 식이섬유, 오리자놀, 불포화지방산 등 다양한 유효성분들이 함유되어 있고, 콜레스테롤 상승억제효과를 비롯한 여러 가지 생리적 효과를 지니고 있는 것으로 알려지고 있으며, 미국에서는 오래 전부터 미강을 빵, 쿠키, 스낵 등의 baked product에 적용시켜 건강식품을 제조하고 있으나 국내에서는 극히 일부가 미강유 제조에 이용되고 있을 뿐 대부분이 사료로 이용되고 있는 실정이다. 본 연구에서는 쌀의 도정에 의해 영양학적으로 손실된 쌀밥의 영양을 강화하고 쌀밥의 저장성을 향상시킬 목적으로 밥물에 미강 ethanol 추출물을 첨가하여 취반하고 쌀밥의 품질특성 및 저장성을 측정하였다. 미강 5~15g 상당량의 추출물과 지방산에스테르 혼합물의 첨가에 의한 쌀밥의 관능적 특성은 전체적으로 기호도, 맛, 향기 면에서 우수한 평점을 얻었으며 조직감에서도 상당히 높은 평점을 얻었다. 색도, 산도, 총세균수의 측정의 결과에 의한 쌀밥의 저장안정성은 3$0^{\circ}C$에서 저장 중, 대조구에서는 3일만에 변질이 되었으나 미강추출물 첨가구에서.는 4~수일간 변질이 지연되어 첨가 농도에 따라 미강추출물의 쌀밥 저장성이 증가되는 것으로 나타났다. 미강추출물을 표준 토코페놀과 비교하여 DPPH 라디컬 소거능에 의한 항산화 활성은 상당한 수준의 값을 나타냈다. 본 연구를 통해 미강추출물의 기능성 검토와 함께 쌀밥의 풍미개선을 위한 제품개발과 쌀 소비 촉진 효과가 기대된다.