• 한국미생물·생명공학회지
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• 제6권1호
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• pp.33-40
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• 1978

Immobilization of alkaline protease was investigated by absorbing the enzyme on adsorbents. Alkaline protease was adsorbed on silica gel selected as a carrier to immobilize the enzyme. In this study, properties of the immobilized enzyme were compared with those of the soluble enzyme. 1) The optimum pH (10.0) of the enzyme was not changed, but the activity was increased at alkaline pH by immobilization. 2) The optimum temperature of the immobilized enzyme was shifted from 50$^{\circ}C$ to 45$^{\circ}C$, while the temperature-activity Profile became broader than those of the soluble enzyme. 3) The pH stability of the immobilized enzyme was significantely increased at pH 4.0, althouth it did not change in the neutral and alkaline pH region. 4) The heat stability of the enzyme was enhanced in the temperature range of 55$^{\circ}C$∼65$^{\circ}C$ by the immobilization. 5) The immobilized enzyme retained 40％ of its original activity after repetitive use for 6 times. 6) The enzyme stability was greately improved for a prolonged storage at 4$^{\circ}C$.

• 한국가스학회:학술대회논문집
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• 한국가스학회 2002년도 추계학술발표회 논문집
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• pp.111-118
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• 2002

• 한국식생활문화학회지
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• 제33권2호
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• pp.125-132
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• 2018

This study was carried out to determine the optimal storage conditions by examining the effects of the storage conditions on the quality of red pepper powder during storage in households. Red pepper powder was stored at room temperature ($20^{\circ}C$), refrigeration (2 and $-1^{\circ}C$) and frozen (-5 and $-20^{\circ}C$) for 3, 6, 9 and 12 months. The ASTA color value, capsanthin content and redness ($a^{\ast}$) of the red pepper powders stored at -5 and $-20^{\circ}C$ were not decreased significantly depending on the storage temperatures until 9 months. The pH of red pepper powder stored at $20^{\circ}C$ decreased significantly until 9 months and increased at 12 months. The microbiological quality of the red pepper powder stored at -5 and $-20^{\circ}C$ was more stable during long-term storage. In the sensory evaluation of red pepper powder stored under all conditions, the overall freshness, redness, hot flavor, moisture release, and edibility decreased with increasing storage period from the control to 12 months. Moisture release increased from 3 months to 12 months. Overall, red pepper should be stored at low temperatures (2, $-1^{\circ}C$) for up to 6 months, and frozen (${\geq} -5^{\circ}C$) for 6 to 9 months. The optimal temperature for long-term storage (${\geq}9$ months) was $-20^{\circ}C$.

• 한국태양에너지학회 논문집
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• 제21권1호
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• pp.61-69
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• 2001

The heat transfer characteristics of horizontal and vertical mantle heat storage tanks are studied in order to replace the tank-coil heat exchanger for application in thermosyphon solar water heaters. In this study, 5 mantle storage tanks with different geometric shape are manufactured into stainless steel and each tank is tested. For the test, The inlet flow rate of the heat transfer fluid is maintained 1.2 lpm consistently. The heat transfer fluid temperature through the mantle is $70{\pm}1^{\circ}C$. The temperatures of 26 points included the ambient temperature are measured at every one minute. The measured data are used to calculate the overall heat transfer coefficient(UA) using the LMTD(Log Mean Temperature Difference) method and it is used on the analysis of the heat transfer characteristics to search for optimum arrangement.

• 한국식품저장유통학회지
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• 제5권2호
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• pp.138-143
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• 1998

The stowage effects of Satsuma mandarin(Citrus unshiu Marc. var. miyagawa) were investigated by selecting various pretreatmnents; non-tested, wax-coating, paper packaging, 0.02mm cryovac film packaging. Weight loss of film packaging was the lowest among that of others, but decay radio was increased highly at late stages of storage. Soluble solids, moisture content of peel and total sugar were maintained almost constant, but acid content, vitamin C and firmness were reduced gradually during storage at room temperature. For 100 days storage, losses from weight and decay of ton-treated, paper packaging, wax-coating and film packaging were 15.9%, 18.5%, 17.4% and 12.9%, respectively. Acid content was decreased loom 1.28% to 0.81∼0.91% after 100 days storage. Ethylene evolution was increased in a degree after 65 days storage, and the amount was increased repidly afer 115 days. it seemed to be derived from decayed fruits and physiological activities. CO2 content of inner part of fruits was increased between 40∼100 days after storage. Optimum storage period of early variety of Satuma mandarin was regarded for 100days on the basis of appeareance and taste.

• 원예과학기술지
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• 제31권3호
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• pp.289-298
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• 2013

마의 수확 후 관리기술 최적화 일환으로 3년에 걸쳐 단계적으로 치유 처리 및 저장온도에 따른 품질변화를 분석하였다. 마 괴근은 11월 초 중순에 수확하였고 수확후처리로서 상온과 $29^{\circ}C$ 열풍 조건에 따라 기간을 달리하는 치유과정을 거쳤다. 치유처리 후 저장온도는 저온장해 발생여부 판단과 저장 기간 최적화를 위해 $0.5-7.5^{\circ}C$ 범위에서 검증과정을 거쳤고 저장기간은 4개월에서 7개월까지 점진적으로 연장하였다. 저장 후 유통품질 유지를 위한 처리로는 단시간 $60^{\circ}C$ 열풍처리 후 $20^{\circ}C$ 상온유통과 $7^{\circ}C$ 저온유통 효과를 비교하였다. 수확 후 치유처리는 마의 호흡속도를 감소시켰고 상온치유보다는 3-5일 열풍치유가 장기저장 후 경도를 유지하고 중량감소를 낮춤으로써 품질유지에 보다 효과적이었다. 다양한 저장온도를 설정한 장기 저장 실험결과, $0.5^{\circ}C$에 저장된 마는 유통과정에서 저온장해 현상으로 판단되는 호흡속도의 증가와 조직붕괴 및 연화현상으로 인한 상품성의 저하가 빠르게 진행되었다. 적정 저장온도로는 저온장해 현상을 보이지 않으면서 품질 저하를 최소화하는 $3-4^{\circ}C$ 범위인 것으로 조사되었다. 장기저장 후 유통과정에서는 발근과 부패 억제 등 품질유지를 위해 저온유통이 필요한 것으로 나타났다. 연구결과를 종합해 볼 때, 마는 수확 후 열풍치유와 $3-4^{\circ}C$ 저장 및 저장 후 저온유통 과정으로 구성되는 최적화 프로그램 적용을 통해 7개월 이상 저장 후까지 품질유지가 가능한 것으로 판단되었다.

• 설비공학논문집
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• 제26권7호
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• pp.322-328
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• 2014

Return piping is used in a solar combi-system for heating and hot water supply. When the temperature of the lower side of a storage tank is low due to hot water usage, the returned hot water after heating is mixed with the lower side cold water of the tank, and the useful energy is reduced. We studied the degree of thermal stratification in the tank, using either a diffuser or a manifold to prevent mixing. Using the diffuser, mixing starts from the bottom of the storage tank. On the other hand, the manifold has the marked effect of preventing mixing. As a result of experiments with changing the diameter and number of holes in the manifold, the optimum condition is 8.5 mm diameter and 96 holes, under the condition of 0.3 lpm.

• 한국수소및신에너지학회논문집
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• 제11권4호
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• pp.171-177
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• 2000

Metal hydride used as hydrogen storage material usually needs the activating process to store the hydrogen at high temperature or high pressure. In general as the particle size of metal hydride becomes smaller, approached to the micro, furthermore, nano scale, storage ability and reaction kinetics are reported to be increased, because the specific surface is extremely increased. But the experimental results demonstrated that the optimum particle size is existed for the best absorbing performance, opposite to the usual expectation. This results from the particles to be come amorphous with their approaching to micro and nano scale, in the storage site within the metal hydride lattice is decreased, which is proved by XRD and SEM.

• 한국작물학회지
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• 제46권4호
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• pp.317-320
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• 2001

Sweet com seeds deteriorate faster due to low starch content than field com seeds when stored for a long tenn. This study had been conducted to observe the seed deterioration of four different sweet corns in a long tenn storage conditions in room temperature. Four kinds of sweet com genes (sh2, bt, su, and se) were harvested from 15 days to 50 days after silking with 5-day intervals. These seeds were stored in the room temperature and tested for germination percentages from 3 months to 18 months period with 3-month interval. su seeds germinated better than other types of gene. Hybrid Mecca which is sh2 gene germinated better when stored for 3 months to 18 months. For all genes, mean regression equations in relation to storage periods showed linear responses. For regression equation, the slope of sh2 gene was lower than that of su gene. The highest slope value was observed in bt gene showing faster deterioration rate. The rate at which seed deteriorates seems to be affected by the date at which it was harvested. The seeds that were harvested at the optimum time deteriorated more slowly than those which were not.

• Journal of Dairy Science and Biotechnology
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• 제41권1호
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• pp.1-8
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• 2023

Response surface methodology (RSM) is a statistical approach widely used in food processing to optimize the formulation, processing conditions, and quality of food products. The homogenization process is achieved by subjecting milk to high pressure, which breaks down fat globules and disperses fat more evenly throughout milk. This study focuses on an application of RSM including the logit transformation to predict the efficiency of milk homogenization, which can be maximized by minimizing the relative difference in fat percentage between the top part and the remainder of milk. To avoid a negative predicted value of the minimum of this proportion, the logit transformation is used to turn the proportion into the logit, whose possible values are real numbers. Then, the logit values are modeled and optimized. Subsequently, the logistic transformation is used to turn the predicted logit into the predicted proportion. From our model, the optimum condition for the maximized efficiency of milk homogenization was predicted as the combination of a homogenizer pressure of 30 MPa, a storage temperature of 10℃, and a storage period of 10 days. Additionally, with a combination of a homogenizer pressure of 30 MPa, a storage temperature of 10℃, and a storage period of 50 days, the level of milk homogenization was predicted to be acceptable, even with the problem of extrapolation taken into account.