• Title/Summary/Keyword: 저장기

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전력사업에서의 초전도 응용

  • 임주일;홍원표
    • 전기의세계
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    • v.37 no.2
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    • pp.13-23
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    • 1988
  • 본고는 전력계통 관점에서 현재 적용이 고려되고 있는 초전도응용 기술중 가장 중요한 초전도 발전기 에너지 저장장치, 케이블송전, 변압기의 적용가능성과 기대효과 기본구조, 특징 등에 대하여 기술하고자 한다.

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Partial Freezing as a Means of Keeping Quality of Sea Foods 1. Keeping Quality of Baked Mackerel Muscle during Partially Frozen Storage (빙결점동결에 의한 수산식품의 품질보존에 관한 연구 1. 빙결점동결 저장 중의 구운 고등어의 품질변화)

  • Lee, Eung Ho;Kim, Jeong Gyun;Ha, Jae Ho;Oh, Kwang Soo;Cha, Yong-Jun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.12 no.2
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    • pp.62-65
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    • 1983
  • As a new practical method for preserving freshness of fish, partially frozen storage has been reported to be useful in terms of K-value, TBA value, sensory evaluation etc. In order to develop a storage procedure to be used in place of cooled or frozen storage for the preservation of precooked fish food, partial freezing for up to two to three weeks was examined using baked mackerel. The criteria for evaluation were made according to the changes in volatile basic nitrogen (VBN), thiobarbituric acid (TBA) value, viable bacterial number, pH, color difference and sensory evaluation in fish muscle. The changes in TBA value of baked muscle during storage at $-3^{\circ}C$ differed slightly from those obserbed during cooled ($5^{\circ}C$) and frozen storage ($-20^{\circ}C$). Partial frozen storage ($-3^{\circ}C$) was effective in prolong an induction period of lipid oxidation during early storage. VBN of baked muscle tends to increase slowly while pH value was decrease during storage and there was no observed significant differences among three different storage condition. Viable bacterial number of the baked mackerel muscle stored at $-3^{\circ}C$ showed significantly less than that stored at $5^{\circ}C$, and similar to that stored at $-20^{\circ}C$ (the levels of $10^2/g$). Judging from the results of sensory evaluation and experimental data, partial frozen storage at $-3^{\circ}C$ seems to be effective as means of short-period preserving baked mackerel.

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Change of fungi and mycotoxin in hulled barley under different conditions and period (저장 중 겉보리에 발생하는 곰팡이와 곰팡이독소 변화)

  • Ham, Hyeonheui;Baek, Jiseon;Lee, Mijeong;Lee, Theresa;Hong, Sung-Kee;Lee, Seungdon
    • Food Science and Preservation
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    • v.24 no.6
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    • pp.857-864
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    • 2017
  • To establish good storage practices for hulled barley against mycotoxin contamination, we measured occurrence of fungi and mycotoxin in hulled barley grains under various storage conditions. Hulled barley grains collected from two places were stored in five different warehouses: 1) two without temperature control, 2) one with temperature controlled at $12^{\circ}C$, 3) a chamber set at $15^{\circ}C/65%$ relative humidity, and 4) one seed storage set at $10^{\circ}C$. The samples were stored for six month with temperature and relative humidity monitored regularly. Every stored samples were retrieved after 0, 1, 3, and 6 month to investigate fungal and mycotoxin contamination. From the stored grains, Fusarium, Epicoccum, Alternaria, and Drechslera spp. were frequently detected. In the warehouses without temperature control, Fusarium and Alternaria spp. constantly decreased, whereas Drechslera spp. increased along with storage period. In the other warehouses with temperature controlled, Fusarium spp. decreased slowly and more than 2.5 log CFU/g of Fusarium spp. were detected after 6 month storage. The level of nivalenol was maintained during 0-3 month but increased after 6 month storage. There was no difference in the nivalenol levels between the warehouses. Therefore reducing storage period less than 6 months could be more effective to control nivalenol contamination in hulled barley grains.

Extended Integral based Governor Control for Power System Stabilization (확장된 PI 제어를 이용한 전력계통 안정도 향상에 관한 연구)

  • Kim, Hyun-Sung;Min, Kyoung-Il;Ryu, Heon-Su;Moon, Young-Hyun
    • Proceedings of the KIEE Conference
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    • 2002.11b
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    • pp.268-270
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    • 2002
  • 본 논문에서는 댐핑이 고려된 전력계통에서 동요시 안정도를 향상시킬 수 있는 확장된 PI제어를 이용한 조속기 제어기를 제안하였다. 전력계통에서의 동요는 대부분 고장기간 동안에 발전기에 저장된 과잉운동에너지에 의해 발생한다. 계통이 안정하도록 하기 위해서 과잉에너지를 효과적으로 다루려면 보통 직접법을 사용된다. 과잉에너지를 제어하기 위한 직접적인 방법으로는 LFC(Load Frequency Control)의 궤한이 활용된다. 확장된 PI제어 방식이 적용된 제어기는 지역내에서와 지역사이에서의 동요를 감쇄시키기 위한 조속기에 적용될 수 있다 또한 제안된 제어기는 조속기에 스팀밸브 제한 조건이나 발전율 제약조건(Generation Rate Constraint; GRC)과 같은 특이점이 존재할 때에도 우수한 성능을 보여주었다. 시뮬레이션은 두지역의 다기계통에서 부하를 변화시켜가며 실시하였다. 시뮬레이션 결과는 제안된 PI 제어기를 기존의 PI 제어기와 비교하여 매우 향상된 성능을 보여주었다.

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Effects of harvest times with polyethylene (PE) film liner, 1-methylcyclopropene (1-MCP) and aminoethoxyvinylglycine (AVG) treatments on fruit quality in 'Sangjudungsi' persimmon during cold storage (수확시기에 따른 수확 후 PE필름, 1-MCP 및 AVG 처리가 '상주둥시' 감과실의 저온저장동안 과실품질에 미치는 영향)

  • Win, Nay Myo;Yoo, Jingi;Ryu, Seulgi;Lee, Jinwook;Jung, Hee-Young;Choung, Myoung-Gun;Park, Kyeung-il;Cho, Young-Je;Kang, Sang-Jae;Kang, In-Kyu
    • Food Science and Preservation
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    • v.24 no.7
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    • pp.898-907
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    • 2017
  • This study was aimed to test harvest time effect with polyethylene (PE) film liner, 1-methylcyclopropene (1-MCP) and aminoethoxyvinylglycine (AVG) treatments on fruit quality attributes in 'Sangjudungsi' persimmon fruit during cold storage. The fruits were harvested 10 days earlier in 2016 than the mature harvest time in 2015. The ethylene production was significantly lower in early harvested fruits than in mature harvested ones. Flesh firmness was maintained higher in 1-MCP treated fruit than in other treatments during cold storage. The rate of fruit weight loss was significantly inhibited by PE film liner treatment during storage, regardless of harvest time. 1-MCP treatment showed less change in fruit peel color variables ($L^*$ and $b^*$) from the calyx-end and equatorial regions during cold storage, compared with those from the control and PE film treatments. The incidence rate of fruit decay and softening was higher in PE film treated fruits than in the other treatments. However, there was no decay detected in AVG treated fruit. The early harvested fruits were maintained higher flesh firmness, compared with mature harvested fruits. Nevertheless, the mature harvested fruits showed much higher soluble solids content, the redness (Hunter a value) of the fruit peel and respiration rate, compared with early harvested fruits. Furthermore, the rate of weight loss in the fruit was remarkably inhibited in the PE film treatment.