• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.943-951
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• 2004

As storing ginger roots under optimum conditions takes high cost, ginger roots are commonly stored in underground tunnels where the maintenance of optimum temperature and humidity is difficult. One of the methods fur long term storage of ginger roots is freezing. The objective of this research was to evaluate effect of storage temperatures and packaging methods on the quality of minced ginger prepared with frozen stored ginger. The minced ginger prepared with frozen stored ginger at $-20^{\circ}C$ was packed in bags, glass bottles and tubes, and then stored at 5 and $-20^{\circ}C$ for quality evaluation at 4 and 15 week-intervals. The changes of surface color, total free sugars, free amino acids and volatile compounds were less in the combined treatment samples than in control during storage, regardless of the storage temperature. The tube packing was the best for maintaining quality of minced ginger during storage among tested packaging methods. Sensory results showed that the minced ginger with the combined treatment and packed in tubes could be stored at 5 and $-20^{\circ}C$ for 12 and 45 weeks, respectively, without a significant drop in palatability.

• The Korean Journal of Food And Nutrition
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• v.11 no.3
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• pp.329-333
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• 1998

The effects of 0.5%(v/v) acetic acid (AA), 0.5%(v/v) lactic acid(LA), or 0.5%(v/w) citric acid(CA) on gram-negative bacterial counts (GNC) and aerobic plate counts (APC) in flatfish strips stored at 4$^{\circ}C$ or 1$0^{\circ}C$ were assessed. Treatments of 0.5% AA were completely (P<0.05) inhibited GNC compared to the initial controls for 12 days at 4$^{\circ}C$. Treatments of either LA or CA rapidly increased GNC compared to those of AA after 9 days at 4$^{\circ}C$. Treatments of AA were microbiological acceptable for 6 days at 1$0^{\circ}C$, but those of LA and CA did not lasted. AA treatments were completely (P<0.05) inhibited aerobic spoilage bacteria (APC) compared to the initial controls for 6 days at 4$^{\circ}C$. Treatments containing either 0.5% LA or 0.5% CA were ineffective after 9 days at 4$^{\circ}C$ and 3 days at 1$0^{\circ}C$, respectively. Based on these results, AA treatment was the most effective for suppressing the growth of aerobic spoilage bacteria during storage at both 4 and 1$0^{\circ}C$. Flatfish strips treated with 0.5% AA extended microbiological shelf-life for 12 days at 4$^{\circ}C$.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04a
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• pp.94-96
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• 2001

본 논문은 Tertiary 저장장치에 기반한 대용량 비디오 서버를 위한 미디어 캐슁 시스템의 설계와 구현에 대해서 기술한다. 대용량 비디오 서버를 위한 미디어 캐쉬는 디스크 저장 장치를 캐쉬 장치로 사용한다. 캐쉬 관리는 서비스의 안정성을 위해 고정 크기의 캐쉬 블록 단위로 관리되며 캐쉬 교체 정책 또는 연속 미디어의 특성을 고려하여 서비스의 안정성과 연속성을 보장 할 수 있도록 하여야 한다. 제시된 캐쉬 관리 정책과 캐쉬 교체 정책을 실제 구현된 서버를 바탕으로 성능 분석한다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.10
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• pp.1543-1549
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• 2015

Black rice bran, a by-product from rice milling process, is a good natural source of anthocyanin pigment. The purpose of this study was to determine the optimum conditions for anthocyanin extraction from black rice bran as well as the stability of anthocyanin extract according to different storage temperatures. The main anthocyanin in 'Heugkwang' rice bran was identified as cyanidine-3-glucoside (C3G) by HPLC and LC-MS/MS. The yield and C3G content of black rice bran extract were investigated with various extraction solvents, temperatures, and times. The results indicate that the optimum extraction solvent, temperature, and time were 50% ethanol, $70^{\circ}C$, and 2 h, respectively. The stability of anthocyanin extract was studied during a storage period of 168 days at various temperatures ($-20^{\circ}C$, $4^{\circ}C$, and room temperature). Hunter's values (L, a, and b) of anthocyanin extract increased, whereas C3G content continuously decreased up to 168 days. Variations in Hunter's values and C3G content become larger as storage temperature increased. Anthocyanin extract from black rice bran was very stable, as C3G content after storage at all temperatures was maintained at more than 90% of initial content. These results suggest that anthocyanin extract from black rice bran may be useful as a natural food colorant.

• Tunnel and Underground Space
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• v.26 no.1
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• pp.12-23
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• 2016

For a successful accomplishment of Carbon Capture Sequestration (CCS) projects, appropriate injection conditions should be designed and optimized for site specific geological conditions. In this study, we evaluated the effect of injection conditions such as injection temperature and injection rate on the geomechanical stability of CCS system in terms of TOUGH-FLAC simulator, which is one of the well-known T-H-M coupled analysis methods. The stability of the storage system was assessed by a shear slip potential of the pre-existing fractures both in a reservoir and caprock, expressed by mobilized friction angle and Mohr stress circle. We demonstrated that no tensile fracturing was induced even in the cold CO2 injection, where the injected CO2 temperature is much lower than that of the reservoir and tensile thermal stress is generated, but shear slip of the fractures in the reservoir may occur. We also conducted a scenario analysis by varying injected CO2 volume per unit time, and found out that it was when the injection rate was decreasing in a step-wise that showed the least potential of a shear slip.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.78-78
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• 2023

기후변화 위기는 유사 이래 인류가 직면한 가장 큰 도전으로 범정부적 글로벌 문제로서 이를 해결하기 위한 다양한 정책들이 범국가 차원 혹은 세계적 기업들에 의해 발표 혹은 시행되고 있다. 이러한 기후변화위기와 탄소배출 저감을 위한 대표적인 대응 방안 중 하나가 바로 재생에너지의 확대·보급 노력이다. 그러나 재생에너지는 날씨와 계절 등 자연환경의 영향을 받는 에너지원으로써 간헐성, 변동성을 가지므로, 시간대별 발전량 예측과 전력공급 안정성에 어려움이 있다. 이러한 문제를 해결하기 위하여 재생에너지 발전은 석탄화력 발전과 달리 전력의 수요와 공급의 균형을 위한 에너지저장장치(Energy Storage System, 이하 ESS)가 있어야 한다. ESS는 전력공급 안정성 향상과 전력 수급의 유연성을 제공하는 장점이 있지만, 초기 설치비용이 높은 단점이 있다. 특히, 배터리 기반 ESS의 경우 높은 구축 비용과 한정적인 충. 방전수명으로 인하여 대용량 ESS로써의 역할 수행에는 분명한 한계가 있다. 하지만 재생에너지와 연계한 ESS로 양수발전댐을 활용할 경우 장주기, 장수명, 대용량 에너지 저장에 매우 합리적인 수단으로 판단되었다. 다만, 양수발전 댐 구축에는 토목공사로 인한 환경 훼손이라는 문제점도 존재한다. 본 고에서는 지역 분산형 소규모 양수발전(Pumped Storage Hydropower, 이하 PSH)댐 구축 및 운영기술 개발을 통해 지역 전력공급과 전력 수급을 조절하면서 변동성 재생에너지를 안정적으로 사용할 수 있는 방안을 소개하고자 한다. 특히, 해당 기술은 지역별 특성에 맞춰 유연하게 설치할 수 있으며, 대규모 토목공사로 의한 환경적 부작용을 최소화할 수 있다. 또한 소규모 PSH는 지역의 저수지 및 수자원을 이용하여 에너지를 저장함으로써 변동성 큰 재생에너지의 유연화 대응과 동시에 안정적인 에너지 공급이 가능하다. 본 고에서는 재생에너지의 확대·보급에 따른 문제점과 대표적 ESS 기술들을 분석·소개한다. 지역분산형 소규모 PSH 기술개발 연구기획 내용 소개를 통하여 전력 생산 및 공급의 탈중앙화를 달성하고, 지역별 변동성 재생에너지의 안정적 활용과 지역 전력공급 특성 및 전력 수급에 대응할 수 있는 방안을 제안하고자 한다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.6
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• pp.520-528
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• 1987

Quality stability of roasted lavers during heat treatment and storage was investigated measuring the changes in pigments including chlorophyll a, carotenoids and biliproteins, fatty acids and free amino acids as the major quality factors. In roasting of fried lavers, carotenoids were found to lie more stable than chlorophyll a, and biliproteins were most heat labile. The overall heat stability of the pigments depended upon heating time and temperature. Chlorophyll a and carotenoids were retained more than $90\%$ in the casts of roasting for 90 min. at $60^{\circ}C;\;60min.\;at\;80^{\circ}C;\;10\;min.\;at\;100^{\circ}C;\;or\;5min.\;at\;150^{\circ}C$ while biliproteins remained about $70\%$. The lipids of dried lavers including polyunsaturated fatty acids appeared rather heat stable when compared to the stability of pigments under the same conditions of roasting. Spray of sesame oil or seasoning solutions on the surface of lavers after roasting seemed desirable for stabilizing pigments and free amino acids during storage particularly at low water activity. And that was also benefit for the protection of polyenoic fatty acids from rapid progress of oxidation during storage. Free amino acids were reduced fast during roasting, especially most of threonine and glycine while glutamic acid was rapidly lost during the storage.

• Tunnel and Underground Space
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• v.19 no.6
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• pp.498-506
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• 2009

The stability assessment of a concrete liner of a compressed air storage tunnel should be performed by an approach which is different from that commonly used for the liners of road tunnels, since the liner is exposed to high air pressure. In this study, the stability analysis method for the liner of compressed air storage tunnel is proposed based on the elastic and elasto-plastic solutions of the thick-walled cylinder problem. In case of elastic analysis, the yield initiation condition at the inner boundary is considered as the failure condition of the liner, while the condition which results in the extension of yielding zone to a certain depth is taken as a failure indicator of the liner in the elasto-plastic analysis taking Mohr-Coulomb criterion. The application of the proposed method revealed that the influence of the relative magnitude of boundary loads on the stability of liner is considerable. In particular, noting that the estimation of the outer boundary load may be relatively difficult, it is thought that the precise prediction of outer boundary load is very important in the analysis. Accordingly, the emphasis is put on the selection of the liner installation time, which may govern the magnitude of outer boundary load.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.4
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• pp.348-355
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• 2023

Biodiesel is known as an environmentally friendly neutral fuel, and a policy of obligatory mixing of a certain ratio is implemented on land. In this study, to verify the feasibility of using biodiesel as a ship fuel, component analysis, metal corrosion test, and storage stability test were performed on the mixing ratios of 0 %, 5 %, 10 %, and 20 % of marine diesel and biodiesel. Component analysis evaluated a total of eight factors including density, kinematic viscosity and flash point according to ISO 8217:2017 standards and the reliability of biodiesel through metal corrosion tests and storage stability tests under atmosphere temperature and harsh conditions (60 ℃) for 180 days. Results demonstrate that component analysis satisfied the ISO 8217:2017 standard in all biodiesel mixing ratios. Furthermore, as the biodiesel mixing ratio increased, the kinematic viscosity, density, and acid value increased and the sulfur content decreased. Metal corrosion rarely occurred in the case of carbon steel, iron, aluminum, and nickel, whereas in the case of copper, corrosion occurred under the influence of oxygen-rich biodiesel under the harsh conditions (60 ℃) of 20 % biodiesel mixture. As for storage stability, discoloration, sludge formation, and fuel separation were not visually confirmed.

• Korean Journal of Food Science and Technology
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• v.20 no.6
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• pp.868-872
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• 1988

The oxidation behaviour of Pinenut(Pinus Koraiensis S & Z) oil during storage were studied. And the oxidative stability of different oil samples by refining stage were also measured. The oil in whole pinenut or mashed pinenut was very stable during the storage at $35^{\circ}C$ for 10 weeks however, the oxidation rate was enhanced when pinenut oil was extracted and isolated from nut cake. On the other hand, crude oil was most stable and the highly purified pinenut oil was least stable, with other samples being intermediate in stability. The changes of fatty acid composition of various pinenut oil samples during storage were also discussed.