• Journal of applied mathematics & informatics
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• 제26권3_4호
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• pp.519-530
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• 2008

This paper studies the multi-domain coupled system of one dimensional Arctic temperature field and establishes identification model about the thermodynamic parameters of sea ice (heat storage capacity, density and conductivity) by the so-called output least-square estimate according to the temperature data acquired by a monitor buoy installed in the Arctic ocean. By the optimal control theory, the existence and dependability of weak solution and the identifiability of identification model have been given. Moreover, necessary optimality condition is proposed. Furthermore, the optimal algorithm for the identification model is constructed. By using the optimal thermodynamic parameters of Arctic sea ice, the numerical simulation is implemented, and the numerical results of temperature distribution of Arctic sea ice are demonstrated.

• Advances in Energy Research
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• 제4권1호
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• pp.47-68
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• 2016

A well designed hybrid power system (HPS) can deliver electrical energy in a cost effective way. In this paper, model for HPS consisting of photo voltaic (PV) module and wind mill as renewable energy sources (RES) and solar lead acid battery as storage device connected to unidirectional grid is developed for peak demand reduction. Life time energy cost of the system is evaluated. One year hourly site condition and load pattern are taken into account for analysing the HPS. The optimal HPS is determined for least life time energy cost subject to the constraints like state of charge of the battery bank, dump load, renewable energy (RE) generation etc. Optimal solutions are also found out individually for PV module and wind mill. These three systems are compared to find out the most feasible combination. The results show that the HPS can deliver energy in an acceptable cost with reduced peak consumption from the grid. The proposed optimization algorithm is suitable for determining optimal HPS for desired location and load with least energy cost.

• Journal of Microbiology
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• 제42권2호
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• pp.99-102
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• 2004

Bacteriophage PM2 has a closed circular form of double stranded DNA as a genome. This DNA from the phage is a useful source for nick-circle endonuclease assay in the fmol range. Due to difficulties in the maintenance of viral infectivity, storage conditions of the phage should be considered for the puri-fication of PM2 DNA. The proper condition for a short-term storage of less than 2 months is to keep the PM2 phage at 4$^{\circ}C$; whereas the proper condition for a long-term storage of the PM2 phage for over 2 months is to keep it under liquid nitrogen in 7.5 ％ glycerol. The optimal conditions for a high yield of phage progeny were also considered with the goal to achieve a successful PM2 DNA preparation. A MOI(Multiplicity Of Infection) of 0.03, in which the OD$\sub$600/ of the host bacteria was between 0.3 and 0.5, turned out to be optimal for the mass production of PM2 phage with a burst size of about 214. Considerations of PM2 genome size, and the concentrations and radiospecific activities of purified PM2 DNA, are required to measure the endonuclease activity in the fmol range. This study reports the proper quantitation of radioactivity and the yield of purified DNA based on these conditions.

• 한국산림과학회지
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• 제99권4호
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• pp.618-624
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• 2010

본 연구는 멸종위기에 처한 꼬리겨우살이 종자로부터 기내배양체계 기반확립을 위해 기내 종자발아 실험을 실시하였다. 꼬리겨우살이 종자는 배지에 치상 1주 후 원기근이 형성되어 발아가 진행되었다. 배지종류와 viscin 유 무에 따른 꼬리겨우살이의 기내 종자발아율은 viscin이 제거된 종자를 SH 배지에 치상하였을 때 가장 높은 발아율(69%)을 나타냈고, 고형지지물 종류와 농도에 따른 발아율은 0.35% gelrite 첨가 시 가장 높은 발아율(75%)을 보였다. 저장 기간과 저장 상태에 따른 발아율은 채집 직후(3일 후) 조건에서 가장 높은 발아율을 나타냈고, 저장기간이 8주, 16주로 길어짐에 따라 발아율은 감소하였다. 흡착판과 흡기근은 White 기본배지에 치상하였을 때 각각 95%, 8%의 형성율을 나타내었다. 꼬리겨우살이의 기내 종자발아과정은 원기근 형성, 흡착판 형성, 흡기근 형성 순으로 진행되었다.

• 한국토양동물학회지
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• 제3권1호
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• pp.9-16
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• 1998

Effects of temperature, pH, and salt concentration on the preservation of the infective juvenile entolopathogenic nematodes, Steinernema carpocapsae, were analyzed. The effects of acclimation to sublethal low temperature and glycerol concentrations on rapid cold hardening of the nematodes were also evaluated to set up the conditions for their cryopreservation. All tested environmental factors could change the storage effectiveness of the nematodes. These analyses indicated that the optinal storage condition for the nematodes consisted of $15^{\circ}C$, pH 8.5, and 0.5-1.0% salt concentration. The nematodes showed a rapid could hardening in response to $5^{\circ}C$ for 2h. Glycerol induced the nematodes to increase the cold hardiness. Its high concentration over 10%, however, gave a harmful effect on the nematode survival.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.403-407
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• 2005

Objective of the research is to demonstrate solar thermal space and ground heating system which is integrated to a greenhouse culture facility for reducing heating cost, increasing the value of product by environment control, and developing advanced culture technology by deploying solar thermal system. Field test for the demonstration was carried out in horticulture complex in Jeju Island. Medium scale solar hot water system was installed in a ground heating culture facility. Reliability and economic aspect of the system which was operated complementary with thermal storage and solar hot water generation were analyzed by investigating collector efficiency, operation performance, and control features. Short term day test on element performance and Long term test of the whole system were carried out. Optimum operating condition and its characteristics were closely investigated by changing the control condition based on the temperature difference which is the most important operating parameter. For establishing more reliable and optimal design data regarding system scale and operation condition, continuous operation and monitoring on the system need to be further carried out. However, it is expected that, in high-insolation areas where large-scale ground storage is adaptable, solar system demonstrated in the research could be economically competitive and promisingly disseminate over various application areas.

• 신재생에너지
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• 제1권2호
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• pp.53-59
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• 2005

Objective of the research is to demonstrate solar thermal space and ground heating system which is integrated to a green-house culture facility for reducing healing cost, Increasing the value of product by environment control, and developing advanced culture technology by deploying solar thermal system. Field test for the demonstration was carried out in horticulture complex In Jeju Island. Medium scale solar hot water system was installed in a ground heating culture facility. Reliability and economic aspect of the system which was operated complementary with thermal storage and solar hot water generation were analyzed by investigating collector efficiency, operation performance, and control features. Short term day test on element performance and Long term test of the whole system were carried out. Optimum operating condition and its characteristics were closely Investigated by changing the control condition based on the temperature difference which Is the most important operating parameter For establishing more reliable and optimal design data regarding system scale and operation condition, continuous operation and monitoring on the system need to be further carried out. However, It is expected that, in high-insolation areas where large-scale ground storage is adaptable, solar system demonstrated in the research could be economically competitive and promisingly disseminate over various application areas.

• 한국지역사회생활과학회지
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• 제17권1호
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• pp.101-108
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• 2006

This study was conducted to develop the regulating methods for the optimal harvest stage of new sprout for woody plants, and to clarify the effects of storage condition and period on the growth of new sprout formed of Aralia elata cv. 'Jeongkwang'. Japanese angelica tree were collected in the Jangheung district of Jeonnam on 20. March, 2005, and those cut branches were stored at $5{\pm}2^{\circ}C$ and 80 to 90% of the relative humidity, and were cut in water. Survival rate of cut branches for Aralia elata cv. 'Jeongkwang' was significantly increased when that was used for the cutting after the collection with no storage. And those survival rate was much more increased when that was stored at 80 to 90% of relative humidity than 40 to 50% of relative humidity. Number of new sprouts formed which were not stored immediately after the collection 3.2 to 3.4, and that were stored at cold storage room before cutting and cut on 1. June and 1. August were 5.1 to 5.3. Leaf growth of cut branches cut in water on 20. March started at ten days after cutting, and that on 1. June and 1. August at one to two days after cutting. Slow and mature sprout growth of Aralia elata cv. 'Jeongkwang' which were cut in water were different by the cold storage periods. Nineteen days were needed for the mature growth of sprout when cut in water on 20. March, and thirteen days on 1. August.

• 한국식품과학회지
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• 제29권4호
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• pp.758-763
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• 1997

당도와 ascorbic acid함량이 높은 우수한 신선 과일인 생대추를 장기간 저장하기 위하여 숙도 및 저장온도에 따른 무등품종 대추의 호흡특성, 저장 중 품질변화를 측정하였다. 녹숙 대추와 적숙 대추의 숙도에 따라서 호흡속도는 차이가 없어서 non-climacteric특성으로 간주될 수 있었고, 호흡의 온도의존성에서도 숙도간에 차이가 없었다. 적숙 대추가 녹숙 대추에 비해서 단위과중이 약간 크며, 가용성 고형분 농도와 ascorbic acid 함량이 약간 높았다. 대추는 저장 중 조직의 연화가 먼저 나타난 후 부패가 진행되었다. 대추의 저장 중 연화 및 부패의 진행은 녹숙대추의 경우가 적숙대추에 비해서 늦어서 장기저장을 위해서는 녹숙대추를 저장하는 것이 유리하였다. 저장 중 녹숙 대추의 표면색택은 붉은 색으로 착색이 진행되고 가용성 고형분은 증가하고, 총산과 ascorbic acid 함량은 감소하였다. $-2^{\circ}C,\;0^{\circ}C,\;5^{\circ}C,\;10^{\circ}C,\;20^{\circ}C$에서의 녹숙 대추의 저장실험에서는 $-2^{\circ}C$에서는 저온장해가 발생하였고, $5^{\circ}C$ 이상의 온도에서는 온도가 높을수록 품질변화와 부패가 빨라서, $0^{\circ}C$가 저장적온으로 판단되었다. 저장적온인 $0^{\circ}C$에서 대추는 40일정도 밖에 신선한 상태로 저장될 수 없어서 보다 장기간의 저장이 가능한 포장 기법의 적용이 필요한 것으로 평가되었다.

• 한국식품영양과학회지
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• 제41권11호
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• pp.1611-1618
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• 2012

깐 도라지와 데친 고사리는 단체급식에서 흔하게 사용되는 전처리 식재료이다. 이 연구는 이들 식재료의 제조공정과 시장에서 유통 중 최적 저장 조건을 확립하기 위해 수행하였다. 이들 식재료를 생산하는 제조업체에 대한 조사를 통해 가장 적합한 제조공정을 개발하였다. 조사한 제조업체 중 한 곳을 선정하여 시료를 채취하였으며 이 시료를 각각 다른 온도(4, 10, $20^{\circ}C$)에서 저장하면서 저장기간(1, 2, 3, 4, 5, 7, 10 days)에 따른 미생물학적, 이화학적, 관능적 품질 변화를 조사하였다. 저장 개시 시점의 도라지의 일반세균수는 5.26 log CFU/g이었고 $4^{\circ}C$ 저장군에서 일반세균수는 3일차까지 별다른 변화를 보이지 않았으나 4일차에 7.63 log CFU/g로 증가하였고 이후 7일차까지 완만하게 증가하였다. 그러나 10, $20^{\circ}C$ 저장군에서는 2일차에 각각 7.42 log CFU/g, 7.86 log CFU/g 수준까지 급격히 증가하였다. 이러한 양상은 데친 고사리에서도 유사하게 나타났다. 이화학적 품질변화의 경우 $20^{\circ}C$ 저장군에서 pH와 경도가 급속히 감소되는 결과를 보였다. 관능품질은 $4^{\circ}C$ 저장군에서 5일차까지 우호적으로 평가(9점 만점에 5~6점)되었으나 나머지 저장 온도군에서는 2일차부터 기호도가 급격히 감소하였다. 따라서 이들 전처리 나물의 최적 저장 조건은 $4^{\circ}C$에서 3일 이내인 것으로 확인되었다.