대류열전달은 겨울철 온실 열손실의 중요한 원인이 되며, 일반적으로 복사열에 의한 손실보다 더 크다. 스크린의 대류열전달계수를 자연상태에서 측정한 연구가 수행된 바는 있지만 상하면의 재질이 동일하고 공극이 없는 스크린에 대해서는 적용을 할 수 없는 방법이다. 이러한 재질의 스크린은 한국에서 많이 사용되고 있으나 대류열전달 특성을 파악하는데 많은 어려움이 있는 실정이다. 본 연구에서는 공극이 없는 3가지 종류의 스크린에 대해 대류열전달계수를 구하였으며, 계수를 산정하기 위하여 복사열수지 이론에 근거하여 산정방법을 개발하였다. 실험장치에 스크린을 설치하고 일사량, 장파복사량, 대기온도, 스크린 및 흑색천의 표면온도, 풍속 등을 측정하였다. 스크린의 표면온도와 주변온도의 차이에 따른 대류열전달계수를 산정하였다. 풍속이 거의 없는 상태에서 온도의 차이가 증가함에 따라 계수는 감소하는 것으로 나타났다.

온실에서 겨울철 야간에는 열손실을 줄이기 위한 목적으로, 여름철 주간에는 차광을 위한 목적으로 스크린을 사용하고 있다. 온실의 냉난방 에너지 절감효과에 큰 영향을 미치는 스크린의 장파복사 방사율과 흡수 율은 온실에 설치할 적절한 스크린을 선택하는데 있어서 중요한 요소가 되며 이러한 특성값들을 정확하게 측 정할 수 있는 방법이 필요하다. 외부 환경조건에서 스크린의 장파복사 특성의 측정과 관련된 연구가 일부 수 행된 바 있지만 모든 종류의 스크린에 적용할 수 있는 방법은 아니고 공극이 있는 스크린 자재에만 적용이 가능한 방법이다. 본 연구에서는 순복사계 및 야간복사계를 사용하여 온실 스크린의 장파복사 흡수량과 방사량을 측정하고, 방사율, 흡수율 및 투과율을 결정하는 새로운 방법을 제시하였다. 특성값의 측정은 공극이 0인 4가 지 종류의 스크린 자재에 대하여 수행하였다. 모든 자재가 장파복사 방사량이 흡수량보다 높게 나타났다. PE, LD-13, LD-15 and PH-2의 장파복사 방사율은 각각 0.439±0.020, 0.460±0.010, 0.454±0.004, and 0.499±0.006 범위로 나타났다.

In the summer season, natural ventilation is commonly used to reduce the inside air temperature of greenhouse when it rises above the optimal level. The greenhouse shape, vent design, and position play a critical role in the effectiveness of natural ventilation. In this study, computational fluid dynamics (CFD) was employed to investigate the effect of different roof vent designs along with side vents on the buoyancy-driven natural ventilation. The boussinesq hypothesis was used to simulate the buoyancy effect to the whole computational domain. RNG K-epsilon turbulence model was utilized, and a discrete originates (DO) radiation model was used with solar ray tracing to simulate the effect of solar radiation. The CFD model was validated using the experimentally obtained greenhouse internal temperature, and the experimental and computed results agreed well. Furthermore, this model was adopted to compare the internal greenhouse air temperature and ventilation rate for seven different roof vent designs. The results revealed that the inside-to-outside air temperature differences of the greenhouse varied from 3.2 to 9.6oC depending on the different studied roof vent types. Moreover, the ventilation rate was within the range from 0.33 to 0.49 min-1. Our findings show that the conical type roof ventilation has minimum inside-to-outside air temperature difference of 3.2oC and a maximum ventilation rate of 0.49 min-1.

Background : The minor saponins produced by the hydrolysis of a major saponins sugar. The minor saponins has high absorption and efficacy compared to major saponin. The acid treatment, heat treatment and fermentation with minor saponin research has been actively conducted. This study was performed in order to investigate the bioconversion of ginsenoside Rg5 of fermented wild ginseng adventitious roots by using lactic acid bacteria. Methods and Results : 20g adventitious roots of ginseng was added to water (10-fold v/w). 10% (v/v) of lactic acid bacteria (Pediococcus pentosaceus HLJG0702[KACC 81017BP]) were inoculated with wild ginseng adventitious roots. For the fermentation process the inoculated samples were transferred to culture room for 1, 3 and 5 days. The fermented samples were dried at room temperature and extracted with 70% ethanol. Extract was concentrated completely at 50 ℃ and Rg5 was analysed by using HPLC. Results showed no significant difference the dry weight of non-fermented and fermented wild ginseng adventitious roots. During the fermentation process, the pH changed from 5.7 to 4.2. HPLC analysis showed higher ginsenoside Rg5 (39.588 mg/g) at 3 days. Conclusion : The fermentation of ginseng root can increase the Rg5 contents and minor saponin composition. This process may be used to enhance the minor saponin thereby increasing in fermented property of wild ginseng adventitious roots.

Background : The study about ginseng cultured roots have been reported mainly ginsenosides in saponins family. Other phytochemical such as non-saponins of fatty acid has been revealed its bioactive activity including anti-oxidation, whitening, anti-cancer. Supercritical extraction (SE) process mainly refer to the extraction with CO2, is usually from a solid matrix, is a sample preparation step for analytical purposes. SE produce no residual solvent and possess high stability of the extract component, which is advantageous for fatty acid analysis. Methods and Results : Fermented ginseng cultured roots used in the experiment were used for fermentation using Pediococcus pentosaceus. SE performed at different temperature, pressure and extraction time using non-fermented and fermented ginseng roots. Further we fractionated from fermented ginseng using Methanol, Hexane, Ethanol, Ethyl acetate and Butanol. We compared fatty acids contents ginseng extractions by GC analysis. Methyl linoleate contents was 44% of fatty acids supercritical extraction contained. The contents of Methyl linoleate was the most dominant component among 37 types of fatty acids by SE and other extractions solvent. Total fatty acids contents obtained by SE process from fermented ginseng (1325.61ppm) was twice than from non-fermented ginseng (618.47ppm). Conclusion : Fatty acids contents by SE was increased at high pressure. The best condition for fatty acids contents extraction was 60℃, 350bar and 3h.

A new standard rose cultivar 'White Christmas' was bred from the cross between red standard cultivar 'Red Queen' and pink standard cultivar 'Vivaldi' at the National Horticulture Research Institute. The cross was made in 2001 and `White Christmas' was finally selected in 2006 after investigating characteristics for three years from 2003 to 2006. 'White Christmas', a white standard cultivar grows vigorously and has good flower shape. The major characteristics of this cultivar are 123.8 stems/m2/year in yield, 82.3 cm in length of cut flower, 11.0 cm in flower diameter, 60.1 in petal number, and 12.2 days in vase life. This cultivar can be propagated by both cutting and grafting. The consumer's preference of this cultivar is relatively higher than that of control cultivar, 'Tineke'.

A new standard rose cultivar 'Magic Pink' was bred from the cross between light yellow standard cultivar 'Medeo' and pink standard cultivar 'Veronica' at the National Horticulture Research Institute. The cross was made in 2001 and 'Magic Pink' was finally selected in 2006 after investigating characteristics for three years from 2003 to 2006. 'Magic Pink', a pink standard cultivar grows vigorously and has fashionable flower color. The major characteristics of this cultivar are 184.8 stems/m2/year in yield, 63.0cm in length of cut flower, 7.2 cm in flower diameter, 28.5 in petal number, and 10.4 days in vase life. This cultivar can be propagated by both cutting and grafting. The consumer's preference of this cultivar is relatively higher than that of control cultivar, 'Noblesse'.

Danok3, a sweet corn hybrid that matures early was developed by the corn breeding team at the National Crop Experiment Station (NCES), RDA in 2001. Inbred KSS2 derived from Golden Bantam was used as the seed parent of Danok3, and inbred KSS22 derived from