• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2001.11a
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• pp.170-175
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• 2001

• Bulletin of Food Technology
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• v.15 no.2
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• pp.107-111
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• 2002

초고압 가공처리는 별동의 화학 보존제를 사용하지 않고도 저온에서 식품유래 미생물을 사멸시킬 수 있기 때문에 식품분야에서 주목받는 새로운 가공기술이다. 이러한 초고압 처리의 장점 덕분에 관능적 특성이 우수하고 영양성분이 그대로 보존되는 고품질 식품의 제조도 가능하다. 고압 조건에서의 미생물 사멸정도를 측정하기 위해서는 흔히 실험실 규모의 장비(그림 1)을 사용하여 소량의 미생물 접종액을 처리함으로서 대량 처리시(그림 2)의 양상을 예측할 수 있다. 초기에 개발된 실험실 귬의 초고압 처리장비에는 일반적으로 고압용기 내부에 온도감지 장치가 부착되어 있지 않아, 압력 조건 하에서의 압축발열 및 순간 감압냉각 효과가 제대로 보고되지 않았다. 그러나 가열효과를 고려하지 않으면 초고압 처리기 특유의 가압 특성 대문에 실험 결과의 재현성을 얻기가 힘들고, 특히 대용량 생산설비의 경우 더욱 그러하다. 이론적으로 초고압 처리는 매우 예측 가능한 공정이다. 즉 고압요기 내부에서는 어느 지점이던 간에 압력이 고르게 분포되고, 가열 확산에 근거한 처리공정과는 달리 압력이 모든 지점에 순간적으로 공정상 불균일이 야기될 소지가 있는 부분은 오직 압축에 다른 발열과 열 전달에 의한 온도 편차에 기인한다. 실제로 처리 대상 제품과 압력 전달매체의 압축시 발열정도 차이와 시료, 매체, 고압용기 간의 열 손실 또는 열 흡수 대문에 고압처리 공정에서 온도가 일정하지 않을 수 있다.

• Food Science and Preservation
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• v.19 no.1
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• pp.31-36
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• 2012

Fresh-cut burdock roots were processed at 4 and $25^{\circ}C$, respectively. The fresh-cut burdock roots were treated with different browning inhibitors (3% citric acid, 3% sodium chloride, 0.3% cystein, and 3% sodium acetate solutions), and the changes in their quality and browning characteristics were investigated. The respiration rate and browning index of the cut roots prepared at $4^{\circ}C$ were lower than those of the cut roots prepared at $25^{\circ}C$. The soluble solid content was higher in the cut roots prepared at $4^{\circ}C$ than in those prepared at $25^{\circ}C$. The weight loss and flesh firmness were not affected by the processing temperatures. Among the browning inhibitors, 0.3% cystein showed the best browning-retarding effect. There was no difference in phenolic compound content between the browning-inhibitor-treated roots and the nontreated roots, but the PPO activity was higher in the latter than in the former. Therefore, the processing temperatures of fresh-cut burdock roots affected their quality and browning development, and the combination of a low processing temperature and the use of the proper browning inhibitor should be applied for the higher quality of the produce.

• Proceedings of the Korean Fiber Society Conference
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• 1996.10a
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• pp.1-5
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• 1996

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.3
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• pp.205-211
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• 2011

This study was carried out to find optimum roasting condition of sesame seeds for making seed season and oil treated with different temperatures and time intervals. Sesame seeds with 17~18% of moisture content were treated under fixed and changed roasting temperature conditions. The fixed temperatures are ranged from 160 to $240^{\circ}C$ with $20^{\circ}C$ intervals. The changed temperatures were treated at low(160 and $180^{\circ}C$) and medium(200 and $220^{\circ}C$) for 10 minutes, and at high(220 and $240^{\circ}C$) for 3 minutes. Meanwhile, roasting times were 20-30 minutes longer under low temperature condition and 3-5 minutes shorter under high temperature condition. The optimum roasting temperature and time were determined as $220^{\circ}C$ and 3 minutes for producing seed season, and as $220^{\circ}C$ and 5 minutes for sesame oil, respectively, in roasting with small quantity of sesame seeds. On the other hand, in the large scale roasting condition, those showed $240^{\circ}C$ and 15 minutes in for producing seed season, and $280^{\circ}C$ and 10 minutes and $260^{\circ}C$ and 15 minute for producing seed season in white-colored sesame variety and black-colored sesame variety, respectively.

• Journal of the Korea Organic Resources Recycling Association
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• v.15 no.1
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• pp.143-148
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• 2007

The objective of this study was to investigate the proper conditions of calcination and calcium extraction from powdered oyster shell. The physical characteristics such as particle size distribution, surface morphology, and thermal gravity were examined. The following result were obtained. As the powdered oyster shell was ignited in high temperature of $650^{\circ}C$ to $950^{\circ}C$, the calcination reactions was effectively progressed. The amount of weight loss during calcination would be matched with the generation of carbon dioxide gas. In the calcination of powdered oyster shell, the amount of weight loss increased according to the increased of calcination temperature and the decrease of mean particle size. It was founded that the proper temperature and retention time of calcination was $850^{\circ}C$ and 40 minute. In the extraction of calcium into liquid form using acid addition, the calcination oyster shell was more effective than the non-calcinated shell. The liquid calcium extraction technique using the calcinated oyster shell needed more researches considering cost evaluation.

• Nuclear Engineering and Technology
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• v.8 no.4
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• pp.203-207
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• 1976

Strain rate dependence of the flow stress of cold-worked and annealed Zircaloy-4 was studied by stress relaxation test in temperature range of 20$0^{\circ}C$ to 45$0^{\circ}C$. The In $\sigma$-ln i curves for various temperatures were straight in the eirange of 10$^{-5}$ to 10$^{-3}$ sec$^{-1}$ . From the slope of a curve strain rate sensitivity m was obtained. The m in cold-worked Zircaloy-4 had a minimum value at 30$0^{\circ}C$, while m in annealed Zircaloy-4 had two minimum values, one at 30$0^{\circ}C$ and the other at 45$0^{\circ}C$. It was found that the temperatures of the minimum m are consistent with the temperatures of strain ageing peaks. The minimum m at 30$0^{\circ}C$ is considered to be due to strain ageing owing to the pinning of glide dislocations by oxygen atoms, while the minimum m at 45$0^{\circ}C$ for annealed specimen is attributed to iron atoms.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.343-347
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• 1994

최근의 기계 가공시스템은 가공기능이 고밀도로 압축되어, 작업자가 진행중인 가공상태를 단시간 내에 파악하기 어려울정도로 복잡하다.그러나 단위 기계별로 공정의 복합화와 자동화가 꾸준히 추진되어 가공기당 투입 작업인원 을 감소시키으로써 생산성을 증가시키고 있다. 이와 함께 작업자의 관리 영역은 오히여 증가해서 여러 대의 기계를 동시에 관리하게 되어, 그 중에 한 기계가 갑자기 이상동작을 일읠 경우 즉각적인 원인파악과 조치를 취하기가 매 우 어렵다. 그래서 요사이 작업자의 이상상태 파악을 위해 감시시스템을 설치하여 즉시 원인을 파악할수 있도록 하고 더 나아가서 자동제어 기능을 추가해서 실시간으로 이상상태를 보완,보정하도록 시도하고 있다. 본 연구에서는 공작기계의 신뢰성있는 열변형 예측을 위해 온도센서의 부착 위치를 최적으로 결정하는 방법을 일점센서와 다점 센서일 경우로 나누어 제시하였다.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2000.10a
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• pp.177-182
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• 2000

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.04a
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• pp.75-75
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• 2006