• Korean Journal of Poultry Science
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• v.17 no.1
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• pp.45-52
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• 1990

This study was carried out to establish shelf-life of the chicken product by examining the changes of physico-chemical and microbilogical quality of it during the storage at different temperature and period. Chicken product was stored at $4^{\circ}C$, $10^{\circ}C$, $25^{\circ}C$ and $30^{\circ}C$ for 32 days and its shelf-life was proved to by 2 days at $30^{\circ}C$, 4 days at $25^{\circ}C$ and $30^{\circ}C$ days below $19^{\circ}C$. There was no significant difference in pH and TBA value of the chicken product VBN content and mesophile count were most proper as a quality indicator because they were lower level until 30 days storage. But gas formation rates and sensory evaluation scores were proper as a quality indicator to estimate the shelf-life of the chicken product during the storage at the different temperatures because it was vacuum packaged. Q$_{10}$ value of the chicken product was calculated as 3.99 by examined data of gas formation rates and sensory scores. Estimated shelf-life of chicken product by Q$_{10}$ value was 1 day at $35^{\circ}C$, 4 days at $25^{\circ}C$ 16 days at $15^{\circ}C$ and 64 days at $5^{\circ}C$ respectively.

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.557-561
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• 2005

Effects of natural preservatives on quality and shelf-life of fresh pork were investigated by evaluating changes in physicochemical properties, sensory evaluation, and mcrobial properties during storage. Acidity and VBN values of pork with preservatives were lower than those of control. Total bacterial count of pork with preservatives was significantly lower than that of control during storage. Sensory results showed pork with preservatives had lower sensory color and off-flavor scores than control. Changes in pH, VBN, total bacterial count, coliform group, and sensory evaluation revealed pork with preservatives showed less quality changes than control during storage, regardless of storage temperature. Results indicated that addition of preservatives to pork increased shelf-life by 7 days at $4^{\circ}C$.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2000.06a
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• pp.39-46
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• 2000

타조알의 형성은 배란된 난자가 나팔관과 난백분비부, 협부, 자궁 그리고 총배설강을 통과하면서 완전한 형태의 알로 산란된다. 그리고 1 clutch size가 40$\pm$15개 정도이다. 알의 크기는 1,450g에서 200~400g의 변이가 있는 것으로 본다. 타조의 난질에는 cuticle 층이 없어서 병원균의 침입에 약하다. 그리고 알의 껍질은 2mm 정도로 두꺼우며 그주요 성분은 달걀의 껍질에서와 마찬가지로 calcium carbonate이다 타조알의수거는 수놈의 방해가 없도록 하여야 하며 bacteria나 fungi의 침입이 업도록 하여야 한다. 수거된 알은 저장하였다가 부화기의 수용능력이 되면 부화를 시작한다. 부화 전에 아를 저장할 경우 15~18$^{\circ}C$로 저장실 온도를 유지하면 7일 정도 저장이 가능하지만 7일 이상 저장할 경우 12$^{\circ}C$로 저장온도를 낮추고 이때 상대습도는 75%로 유지하는 것이 이상적이다. 부화기의 온도는 36.0~36.5$^{\circ}C$가 이상적이며 이때 이상적인 습도는 35%이하이어야 한다. 또 부화중 전란을 하여야 하는데 대개 한시간에 한번씩 74~90。로 전란 해주는 것이 바람직하다. 부화에 적당한 알은 기형적으로 크거나 작으면 부화율을 높이지 못한다.

• Journal of Korean Society of Forest Science
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• v.105 no.1
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• pp.93-102
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• 2016

This research was conducted for major cultivated chestnut (Castanea spp.) in Korea to compare chestnut quality characteristics according to storage temperatures ($4^{\circ}C$ vs. $-1^{\circ}C$) and cultivars. Color, hardness, soluble solids content (SSC), rate of decay and sensory evaluation were investigated during 16 weeks storage. Cultivars 'Tsukuba' and 'Ishizuchi' showed the least pericarp color change while cultivars 'Riheiguri' and 'Daebo' showed the most pericarp color change during storage. Chestnut fruits stored at $-1^{\circ}C$ showed less pericarp color change than those stored at $4^{\circ}C$. Cultivars 'Arima' and 'Tanzawa' exhibited the decrease tendency of hardness with lowest hardness during storage at $-1^{\circ}C$. Chestnut fruits stored at $4^{\circ}C$ showed high hardness than those stored at $-1^{\circ}C$. Cultivars 'Riheiguri' showed the highest increase of SSC, while cultivar 'Arima' showed the lowest increase of SSC after 16 weeks of storage. The SSC increased in nuts from all cultivars at both temperatures, but nuts stored at $-1^{\circ}C$ showed higher increases in SSC than nuts stored at $4^{\circ}C$. Cultivars 'Ishizuchi' and 'Riheiguri' showed high rates of decayed nuts in contrast to cultivars 'Daebo', 'Okkwang' and 'Tanzawa' that showed low rates of decayed nuts during storage. The chestnut fruit stored at $-1^{\circ}C$ showed less decay than fruit stored at $4^{\circ}C$. Texture and sweetness were tested for sensory evaluation. Among the tested cultivars, 'Riheiguri', 'Daebo' and 'Tsukuba' showed hard texture and very sweetness, while 'Tanzawa' showed relatively soft texture. 'Arima' and 'Okkwang' showed weak sweetness during storage. Nuts stored at $4^{\circ}C$ exhibited harder texture than nuts stored at $-1^{\circ}C$ while $-1^{\circ}C$ exhibited more sweetness than nuts stored at $4^{\circ}C$. Chestnuts for hard texture and short-term storage (less than one month), $4^{\circ}C$ will be a proper storage temperature, while in order to store long-term (more than 4 month), $-1^{\circ}C$ will be a proper storage temperature. Result from this study provide base-line data of postharvest management for Korean cultivated chestnut as well as contributing increased product value and income for chestnut producers.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2004.04a
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• pp.101-110
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• 2004

지하냉동 저장고 주변의 온도분포를 예측하기 위하여 국내 최초로 건설된 상업적 규모의 지하암반 저장고인 '곤지암 지하암반 저장고'에 대한 약 5년간의 암반 온도 계측 결과와 FLAC을 이용한 2차원 및 3차원 수치해석 결과를 비교하였다. 수치해석 수행 시 지하수, 지하수의 동결잠열, 지표온도의 영향을 고려하였으며, 각각의 요소가 지하암반 온도분포에 미치는 영향을 계측자료와의 비교를 통하여 분석하였다. 각각의 경우에 대한 2차원 수치해석과 계측결과를 비교한 결과 지하수와 동결잠열을 같이 고려한 경우가 지하수의 영향만 고려한 경우에 비해 오차가 적게 나타났으며, 2차원 해석에서는 냉동기 가동 시간이 경과하면서 지표면의 영향으로 오차가 커지는 경향이 나타났다. 3차원 수치해석은 지표까지 거리의 영향을 고려하여 수행하였으며, 해석결과 2차원과 같이 지하수 및 동결잠열의 영향이 고려된 해석이 가장 작은 오차를 나타내었으며, 시간의 경과에 따른 오차의 증가는 없었다.

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.2
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• pp.54-61
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• 2007

Propellant pressurization system in liquid rocket propulsion system plays a role supplying pressurant gas at a controlled pressure into the ullage space of propellant tanks. The most important design parameter for such propellant pressurization system is the temperature of pressurant gas fed from pressurant tank. Such pressurant is gaseous state, of which density is very sensitive to the temperature of pressurant. Generally for the propulsion system, which requires high thrust and is consisted of cryogenic propellant the pressurant is stored at high density and high pressure to reduce the weight of pressurant tanks, which are placed inside of cryogenic propellant tank. That is called cryogenic storage pressurization system. This study investigates the temperature variation of pressurant at the time when the pressurant is coming out of pressurant tank experimentally as well as numerically. Fluids used in this study are air and liquid oxygen as outer fluid and gaseous nitrogen and gaseous helium as pressurant respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.1
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• pp.7-12
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• 1994

The kinetics of browning reaction of dried shrimp powder samples were investigated during storage. The temperature conditions of the ding process were $25^{\circ}C\;and\;45^{\circ}C$, and the samples were stored at water activity ($a_w$) of 0.33, 0.44, 0.52, 0.65 and temperatures of $35^{\circ}C,\;45^{\circ}C,\;55^{\circ}C$ and temperature fluctuations between $33^{\circ}C\;and\;55^{\circ}C$. When the shrimp was dried at $25^{\circ}C$ the activation energies obtained from the Arrhenius plot ranged from 13.57 to 14.33 kcal/mol. From these energies of activation, the $Q_{10}$ values at $25^{\circ}C$ showed 1.93 to 2.00. In the case of drying at $45^{\circ}C$ the activation energies were $13.12{\sim}13.61\;kcal/mol$ and $Q_{10}$ values were $1.89{\sim}1.93$, respectively. In addition, a storage study under square-wave fluctuating temperature conditions was carried out by varying the shrimp sample temperature between $35^{\circ}C\;and\;55^{\circ}C$ within 7 days regular fluctuation cycle. The data obtained from the fluctuating temperature storage study will be used in the prediction of shelf-lives. The shelf-lives assessed at $25^{\circ}C$ from the accelerated shelf-life tests ranged from 4 days at aw 0.65 to 139 days at aw 0.33.

• Tunnel and Underground Space
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• v.14 no.1
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• pp.16-25
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• 2004

As underground caverns have many advantages such as safety and operation, they can also be used for gas storage purpose. When liquefied gas is stored underground, the cryogenic temperature of the gas affects the stability of the storage cavern. In order to store the liquefied gas successfully, it is essential to estimate the exact temperature distribution of the rock mass around the caverns. The main purpose of this study is the development of theoretical solution to be able to estimate the temperature distribution around storage caverns and the assessment of the solution. In this study, a theoretical solution and a conceptual model for estimating two and three dimensional temperature distribution around the storage caverns are suggested. Based on the multi-dimensional transient heat transfer theory, the theoretical solution is successfully derived by assuming the caverns shape as simplified geometry. In order to assess the theoretical solution, by performing numerical experiments with this multi-dimensional model, the temperature distribution of the theoretical solution is compared with that of numerical analysis. Furthermore, the effects of the caverns size are investigated.

• Korean Journal of Food Science and Technology
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• v.22 no.7
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• pp.833-839
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• 1990

To examine the effects of nitrogen flushing on the storage stability of red pepper powders, the color and capsanthin and capsaicin contents were investigated. Capsanthin and capsaicin contents of red pepper powders during their storage decreased as the increase of temperature. Nitrogen flushing packaging was good for the retention of capsanthin and capsaicin than air packaging. Brown color of red pepper powders during their storage differed with storage temperature and packaging condition, thus low temperature and nitrogen reduced the brown color substantially, L and b values by Hunter's color were almost not changed during 10 months storage of red pepper powders, and a value was decreased as the increase of temperature. Therefore, nitrogen flushing packaging for the storage of red pepper powders was good than air packaging.

• Food Science and Preservation
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• v.20 no.6
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• pp.766-774
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• 2013

The effect of storage temperatures ($0^{\circ}C$and $20^{\circ}C$) and packing functional film for fruit quality were examined in 'Fuyu' persimmon. The fresh weight loss was delay more effectively by the inhibition of transpiration when functional film was used. The firmness was effectively maintained in functional film packages at low temperature ($0^{\circ}C$), which might result from the beneficial combination of $CO_2$ and $O_2$. The soluble solid contents was higher with packing of functional film at $0^{\circ}C$ than at room temperature ($20^{\circ}C$). Highest $CO_2$ production in functional film bags was observed in room temperature storage after one week and thereafter declined sharply whereas lowest in 8 weeks. $CO_2$ concentration regardless of packing slowly increased to $5.2{\mu}L{\sim}10.2mL{\cdot}kg^{-1}{\cdot}h^{-1}$ until 8 weeks of low temperature due to persimmon respiration. Hunter 'b' value changed greatly yellowness according to temperature of storage but there were no significant differences among packaging treatments. Effects of functional film and low temperature in slower softening were consistent. This results suggested that the packing functional film at low temperature resulted in the best retention of quality market.