• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.2
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• pp.215-223
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• 1987

This experiment was carried out to determine the effect of nitrogen application on the cold tolerance of rice plant, with treatment of three levels of nitrogen and three times of application under the low temperature at tillering and panicle initiation stages. The higher cold tolerance variety was increased in plant height and number of tillers on high nitrogen level during the low temperature treatment. Nitrogen content of leaf blade was increased, but carbohydrate content was decreased during the low temperature treatment at tillering stage. Ethylene evolution from leaf was remark-ably increased just after low temperature treatment. Highly significant negative correlation was observed bet-ween the nitrogen content of leaf blade and percentage of filled grain under low temperature condition at reproductive growth stage.

• Superconductivity and Cryogenics
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• v.9 no.2
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• pp.27-31
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• 2007

• Superconductivity and Cryogenics
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• v.13 no.2
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• pp.17-20
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• 2011

• Korean Journal of Food Science and Technology
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• v.32 no.3
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• pp.513-518
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• 2000

Volatile flavor components of Angelica gigas Nakai affected by different storage time and temperature were investigated. The aroma compounds was extracted by a simultaneous distillation and extraction method using a Likens and Nickerson's apparatus. The concentrated extract was analyzed and identified by GC and GC-MS equipped polar and nonpolar column. The yields of volatile concentrates of Angelica gigas Nakai by low temperature storage were larger than those by room temperature storage. The GC patterns of the flavor components of both resembled but the peak area of each flavor compounds was little different. Main volatile flavor components of Angelica gigas Nakai by using polar column were ${\alpha}-pinene$, ${\beta}-pinene$, terpineol, farnesol, cadinene, guaiol, isolongifolene and eudesmol etc. Main volatile flavor components of Angelica gigas Nakai by using nonpolar column were camphene, ${\beta}-pinene$, elemol, eudesmol etc.

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.303-308
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• 2007

An accumulation levels of osmolytes in chilling-tolerant and chilling-sensitive cultivar of Cucurbits against chilling stress were determined during chilling stress. Total soluble sugar contents in tolerant cultivar did not changes fur 10 days after chilling stress, but then slightly increased 20 days after chilling stress. In sensitive cultivar, it was increased rapidly in the beginning of chilling stress, and increased 3.4 times as much 20 days after chilling stress as compared with unstressed plants. Proline contents in tolerant cultivar was rapidly increased by the beginning of chilling stress, and then increased 26.6 times 20 days after chilling stress as compared with unstressed plants. In sensitive cultivar, it was increased 22.0 times 20 days after chilling stress as compared with unstressed plants. A levels of glycine betaine (GB) in tolerant cultivar increased 1.9 times as much during the 20 days of chilling stress. However, concentration of GB in sensitive cultivar did not change during the chilling stress. When plants were treated exogenous GB as a foliar spray, chilling tolerance was significantly enhanced in both cultivars. The foliar application of exogenous GB was induced chilling tolerance by accumulation of GB in the plant organs. However, it does not accumulate endogenous proline.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.07a
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• pp.310-315
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• 2002

겨울철 저온기에 온실의 작물재배는 많은 에너지가 소요되어 저온기의 에너지비용을 최소화하는 것이 온실의 운전비용의 절감과 이용효율이 증대되어 농가소득을 높일 수 있다. 저온기에는 작물의 수확량이 적정 온도조건의 80%수준으로 최소 에너지 투입방법 기술을 개발하여 수확량을 증대시킬 필요가 있다. 기존의 난방방법인 온수보일러는 온도유지 안정성은 좋으나 시설비용이 많이 들고 온풍난방은 설치비용은 저렴하나 온도 유지안정성이 다소 떨어지는 단점이 있다. (중략)

• Journal of Energy Engineering
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• v.24 no.2
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• pp.144-153
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• 2015

At low temperature, Wax build-up and settling can affect adversely the cold weather performance of the diesel vehicle. In this study, we test the cold properties of diesel by blending ratio of biodiesel, kerosene and WAFI. Also, we test the cold weather performance for diesel vehicle by fuel cold properties. Cold properties of diesel are improved by adding the WAFI, kerosene and get worse by adding the biodiesel. WAFI is effective to improve a cold filter plugging point(CFPP) and Kerosene is effective to improve a cloud point(CP). CFPP and pour point(PP) are related to cold weather performance of diesel vehicle but CP is unrelated. CFPP indicate a limit temperature of vehicle driving possibility.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.04a
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• pp.132-132
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• 2003

포도 중 캠벨얼리 품종은 색이 검붉고 당도가 높아 우리나라 대표적인 품종 중에 하나로 알려져있다. 그러나 수확 후 저장 유통 중 품질이 저하되기 쉽다. 따라서 예냉 조건 및 수송, 저장, 유통조건에 따른 품질조사를 비교실험하여 가장 안전한 저장 유통 방법을 개발하고자 하였다. 실험재료는 2003년 8월20일경에 포도 주산지인 영천 농가에서 수화 한 후 바로 예냉처리를 하였다. 이때 사용한 예냉기는 원예연구소에서 개발한 시제작품을 사용하였다. 대조구로 무예냉을 두었으며 예냉 후 수송온도도 관행적인 상온과 저온(2$^{\circ}C$)로 구분 처리하였으며 저온온도별로도 함께 실험하였다. 포장단위도 2kg 와 5kg로 각각 처리하여 수행하였다. 예냉이 품질에 미치는 영향을 조사하기 위하여 예냉처리에 따른 호흡패턴 변화와 이화학적 특성변화를 조사하였다. 또한 저장 중 중량감소율, 부패율 및 탈립율을 조사하였다. 포도 ‘켐벨얼리’의 수확 시 품온 29.5$^{\circ}C$를 적정 저장 온도인 2$^{\circ}C$로 저하시키는데 일반 저온 저장고에서 10시간 정도 걸리는 데 반하여 차압예냉기 이용시 3시간으로 단축시킬 수 있었으며 예냉 포도의 처리구별 호흡량은 초기 6.65$m\ell$/kg/hr 였으나 상온무예냉 및 예냉 처리구의 경우에는 저장해가면서 급격히 증가되었고 저온에서는 무예냉의 경우에는 계속 증가되는 반면 예냉 처리구의 경우에는 포장 규격과는 상관없이 다른 처리구 보다 호흡억제 효과가 있었다. Ethylene 발생량 역시 호흡과 비슷한 경향을 보여 주어 예냉 시 과실의 품질 저하 요인 발생량을 억제시킬 수 있었다. 경도는 저장 기간이 경과됨에 감소되나 저온 예냉 처리구의 경우가 초기 1.26N을 높게 유지하였고 자연중량 감모율은 상온저장 2주째 무예냉처리구 8.40%로 감소된데 비하여 예냉 저온 수송 구의 경우에는 0.25%로 매우 낮았다. 포도 ‘켐벨얼리’의 저온 저장중 부패율은 저장 2주째 상온 무예냉 처리구의 경우 19.8%이었으나 저온 예냉 처리구의 경우는 부패과가 발생하지 않았고 탈립율 역시 상온무예냉처리구의 경우 53.5%인데 반하여 저온 예냉 처리구는 저장 4주경과 시까지 탈림과가 없었다. 당도 및 pH변화 역시 차압 예냉 후 저온 수송 처리구가 초기당도(12.0Bx)$^{\circ}$값과 초기 pH(3.8)를 저장 25일 경과시까지 유지하였다. 수확 시 높은 품온을 갖고 있는 과일을 산지에서 예냉 처리를 한 후 저온 냉장차를 이용하여 유통한다면 관행 유통 구조보다 고품질의 포도를 유통시킬 수 있는 것으로 사료되며 앞으로는 완숙된 고 당도(12.0~15.0Bx)$^{\circ}$ 포도를 수확 한 즉시 예냉 처리하고 저온 유통한다면 보다 신선한 과일을 소비자에게 전달 할 수 있을 것이다.

• Korean Journal of Environmental Agriculture
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• v.20 no.2
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• pp.93-98
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• 2001

A chilling-tolerant japonica-type and a chilling-susceptible indica-type of rice (Oryza sativa L.) plants were compared with respect to various physiological parameters during chilling and subsequent recovery. The japonica-type and the indica-type of rice cultivars used were Ilpumbyeo and Taebaekbyeo, respectively. The two rice cultivars exhibited little or no differences in the changes of leaf fresh weight and chlorophyll content during chilling at $5^{\circ}C$ for 3 days. During subsequent recovery at $25^{\circ}C$, however, Ilpumbyeo restored its growth more rapidly than Taebaekbyeo. Since the changes of relative water content, malondialdehyde production, an estimate of lipid peroxidation, and chlorophyll fluorescence were significantly different in the two rice cultivars during the chilling and subsequent recovery, they were found to be more sensitive physiological parameters than fresh weight and chlorophyll content. However, the differences in relation to water content, malondialdehyde production, and chlorophyll fluorescence between the two rice cultivars were smaller during chilling than those during subsequent recovery. These results suggest that relative water content, malondialdehyde production, and chlorophyll fluorescence could widely be used as important physiological parameters for screening chilling-tolerant plants.

• Superconductivity and Cryogenics
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• v.14 no.1
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• pp.15-20
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• 2012