• 한국초전도ㆍ저온공학회논문지
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• 제26권1호
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• pp.20-24
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• 2024

Over the past four years, as the COVID-19 pandemic has struck the world, cold chain of COVID-19 vaccination has become a hot topic. In order to overcome the pandemic situation, it is necessary to establish a cold chain that maintains a low-temperature environment below approximately 203K (-70℃), which is the appropriate storage temperature for vaccines, from vaccine suppliers to local hospitals. Usually, cryocoolers are used to maintain low temperatures, but it is difficult for small-scale local distribution to have cryocooler due to budget and power supply issues. Accordingly, in this paper, a cryogenic TSU (Thermal storage unit) system for vaccination cold chain is designed that can maintain low temperatures below -70℃C for a long time without using a cryocooler. The performance of the TSU system according to the energy storage material for using as TSU is experimentally evaluated. In the experiments, four types of cold storage materials were used: 20% DMSO aqueous solution, 30% DMSO aqueous solution, paraffin wax, and tofu. Prior to the experiment, the specific heat of the cold storage materials at low temperature were measured. Through this, the thermal diffusivity of the materials was calculated, and paraffin wax had the lowest value. As a result of the TSU system's low-temperature maintenance test, paraffin wax showed the best low-temperature maintenance performance. And it recorded a low-temperature maintenance time that was about 24% longer than other materials. As a result of analyzing the temperature trend by location within the TSU system, it was observed that heat intrusion from the outside was not well transmitted to the low temperature area due to the low thermal conductivity of paraffin wax. Therefore, in the TSU system for vaccine storage, it was experimentally verified that the lower the thermal diffusivity of the cold storage material, the better low temperature maintenance performance.

• 한국가금학회지
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• 제14권2호
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• pp.137-143
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• 1987

육계육의 가승근육과 다리근육을 4$^{\circ}C$ 및 -2$0^{\circ}C$에 저장하면서 근원섬유단백질과 actomyosin을 추출하고 그 추출성, 생물활성 및 용해도를 비교한 결과는 다음과 같다. 1. Myofibril의 추출성은 가슴 및 다리근육 모두 냉장기간이 길어지면서 점차 높아지고. 동결저장기간이 경과되면서 다소 낮아졌다. Actomyosin의 추출성은 가슴 및 다리근육 모두 냉장 중에 큰 변화를 보이지 않았으며, 동결저장의 경우 저장기간이 경과하면서 점차 감소하였다. 2. Myofibril의 $Ca^{2+}$-ATPase 활성은 가슴 및 다리근육 모두 냉장 7일까지 큰 변화는 없었으며, 동결저장의 경우 2주째 가장 농은 활성을 보였고 그 이후는 감소하였다. Actomyosin의 $Ca^{2+}$-ATPase 활성은 가슴 및 다리근육 모두 냉장 중에 큰 변화를 보이지 않았으며, 동결저장의 경우 저장기간이 경과하면서 점차 감소하였다. 3 근원섬유단백질은 염농도에 따라 신선육의 경우 가슴 및 다리근육 모두 0.20M KCl, 냉장육은 가슴 및 다리근육이 각각 0.25M KCl. 0.30M KCl, 그리고 동결저장육은 가슴 및 다리근육 모두 0.30M KCl 에서 용해되었다. Actomyosin은 염농도에 따라 신선육의 경우 가슴 및 다리근육 모두 0.20M KCl에서 용go되기 시작하였고, 가슴근육은 냉장 1일에 0.25M KCl. 냉장 3. 5, 7일에 0.30M KCl, 다리근육은 냉장기간에 관계없이 모두 0.25M KCl에서 용해되기 시작하였다. 또한, 동결저장 중 가승근육은 0.30M KCl, 다리근육은 0.25M KCl에서 용해되기 시작하여 모두 0.40M KCl에서 완료되었다.

• 대한설비공학회지:설비저널
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• 제5권2호
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• pp.108-114
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• 1976

• 대한설비공학회지:설비저널
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• 제5권2호
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• pp.115-121
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• 1976

• 농업과학연구
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• 제47권3호
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• pp.625-632
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• 2020

This test was conducted to determine the appropriate conditions of temperature, storage period, and soil moisture content when using cold storage of potted mother plants of as a means of sufficient dormant breaking and safe overwintering of the strawberry (Fragaria × ananassa Duch. cv. Sulhyang) mother plants. In the treatment by temperature for the dormant breaking of strawberry mother plants, the survival rate of natural overwintering was 91%, whereas the survival rate was 100% at 0, - 2, and - 5℃. As the storage temperature was decreased, the plant height of the mother plants became shorter which tended to decrease after planting. Survival of the mother plants was possible at - 5℃, but after planting, the growth and number of daughter plants decreased significantly. The number of daughter plants was highest at 22.8 per plant at - 2℃ storage. The strawberry mother plants could be stored for up to 8 months in cold storage. However, when the mother plants were stored for a long period, the number of daughter plants was small. When they were stored for 4 months, the growth of the mother plants was vigorous, and the number of runners and daughter plants was high. When the water content of the soil was less than 10 percent (%, w/w) in the cold storage of the pot, the survival rate was 85 percent, which was high due to the dryness. The survival rate was 100 percent at 30 and above, and the growth of the mother plants after planting and the number of daughter plants were high at 30 to 50.

• 한국태양에너지학회 논문집
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• 제32권6호
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• pp.22-28
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• 2012

The purpose of this study was to show how tomaintain high efficiency and to use reasonably when being applied the cold-heat storage systems to the showcase. An experimental study was performed to manufacture the showcase system in a laboratory. Comparing the result at general operation condition with that of the new condition using ice storage system, this study showed the effects of the refrigerant sub-cooling, and with using inverter. Using ice storage system, the ice making process was operated during midnight being not needed the cooling of the showcase through the continuous running of the condenser unit. And then, the refrigerant was sub-cooled using the stored cold-heat after being discharged from the air cooling condenser during the day time. Through the experiments, the load transfer rate for the showcase using inverter and ice storage was estimated about 30.0%. And showed that the total power consumption of the showcase with inverter could be reduced about 37% than that of the showcase without inverter.

• 한국수산과학회지
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• 제38권4호
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• pp.239-244
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• 2005

The effects of diluents composition on cold storage for olive flounder (Paralichthys olivaceus) sperm were examined in terms of the swimming speed of sperm, the percentage of mobile sperm, and fertilization rates. The following results indicated that cold storage methods with fresh conditions could be employed in olive flounder milt preservation. The preserved sperm of olive flounder that was diluted I: 10 with artificial seminal plasma II (ASP II) and Stein's solution (SS) at $0^{\circ}C$ remained motile for 30 days. The most effective condition for cold storage was ASP II and SS at 0 $0^{\circ}C$ for the sperm, although there is no significant difference statistically. No difference in the fertilization rate was found between fresh sperm and the preserved ones with ASP I, II and SS at 10 days post-storage.

• 수산해양교육연구
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• 제26권4호
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• pp.760-768
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• 2014

Yet logistics base in China has a refrigerated storage facilities installed areas, the number of those is very limited and is generally insufficient. According to these especial points, a new construction cold chain logistics network design strategy is required from how to use the existing refrigerated warehouses to new issue. For example, however refrigerated storage facility is supplied, can it satisfy all demand of this area? Then does it have optimized location of this area? If future demand expansion, adding that already other refrigerated storage facilities matter? Or, add another refrigerated facilities, optimum cold chain established a network matter? So on. Above problems can be occurred. In order to solve facing many of these issues of distribution network, northeast area in China has been selected as a subject, and we designed a new cold chain distribution network.

• 동아시아식생활학회지
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• 제19권2호
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• pp.224-230
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• 2009

본 연구는 계피, 감초 및 복분자 추출물의 첨가가 냉장 저장 중 쇠고기 분쇄육의 품질에 미치는 영향을 규명하기 위하여 물 10% 첨가한 분쇄육(대조구), 계피 추출물 10% 첨가한T-1구, 감초 추출물 10% 첨가한 T-2구 그리고 복분자 추출물 10% 첨가한 T-3구 등 네 종류의 쇠고기 분쇄육을 제조하였다. 그리고 냉장 저장 중 표면 색도, 보수력, 가열 감량, 두께, 직경, pH, VBN 함량 및 TBARS 값을 실험하였다. 냉장 저장 중 $L^*$ 및 $a^*$값은 유의하게 감소하였으며(p<0.05), $b^*$값은 유의한 변화가 없었다. 그리고 약용 식물 추출물은 색깔에 영향을 미치지 않았다. 보수력은 냉장 저장 중 유의하게 증가하였으며(p<0.05), 약용 식물 추출물은 보수력에 영향을 미치지 않았다. 가열 감량은 T-1구를 제외한 나머지 실험구에서 유의하게 감소하였다(p<0.05) 그리고 두께 및 직경은 냉장 저장 중 유의한 변화가 없었으며, 약용 식물 추출물 첨가에 의한 영향은 없었다. 대조구의 pH는 6일까지 낮아지다가 9일째 높아졌으며, 약용 식물 추출물 첨가구는 저장 기간의 경과와 함께 낮아졌다. VBN 함량은 냉장 저장 중 증가하였으며, 대조구가 약용 식물 첨가구보다 높았다. TBARS 값은 냉장 저장 중 약용 식물 추출물 첨가구가 대조구보다 낮았다.

• 해양환경안전학회지
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• 제21권5호
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• pp.577-582
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• 2015

본 논문은 육해상의 운송장치에 축냉시스템을 적용시키기 위한 기초 연구이다. 또한, 축냉재의 고액상변화에 대한 수치해석을 수행한 연구이다. 수치해석법으로는 유한차분법(Finite-Difference Method)을 이용하였으며, 1차원 비정상의 상태를 가정하여 계산하였다. 또한 용기는 직사각형의 구형용기로 가정하여 대칭의 조건을 이용하였다. 축냉을 목적으로 사용하는 열매체는 염화칼슘 수용액($CaCl_2$) 30wt%의 물성치를 사용하여 계산을 수행하였다. 계산에 영향을 미치는 요소로는 냉동고의 냉기 온도 및 냉기 유속이 있으며, 축냉재를 싸고 있는 용기는 플라스틱으로 가정하였다. 본 수치해석에서 경계층의 두께는 냉기의 속도 증가와 함께 얇게 되고 축열시간도 짧아지는 것을 확인할 수 있었다. 그리고 냉기의 유속이 빨라질수록 열전달이 촉진되어 축냉용기 전면부에서의 온도가 낮아짐을 알았다. 축냉용기의 후면부에서는 경계층이 두꺼워져 열전달이 전면부에 비해 작아짐을 알았다.