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        검색결과 6

        2.
        2023.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        High-pressure sodium (HPS) lamps have been widely used as a useful supplemental light source to emit sufficient photosynthetically active radiation and provide a radiant heat, which contribute the heat requirement in greenhouses. The objective of this study to analyze the thermal characteristics of HPS lamp and thermal behavior in supplemented greenhouse, and evaluate the performance of a horizontal leaf temperature of sweet pepper plants using computational fluid dynamics (CFD) simulation. We simulated horizontal leaf temperature on upper canopy according to three growth stage scenarios, which represented 1.0, 1.6, and 2.2 plant height, respectively. We also measured vertical leaf and air temperature accompanied by heat generation of HPS lamps. There was large leaf to air temperature differential due to non-uniformity in temperature. In our numerical calculation, thermal energy of HPS lamps contributed of 50.1% the total heat requirement on Dec. 2022. The CFD model was validated by comparing measured and simulated data at the same operating condition. Mean absolute error and root mean square error were below 0.5, which means the CFD simulation values were highly accurate. Our result about vertical leaf and air temperature can be used in decision making for efficient thermal energy management and crop growth.
        4,000원
        3.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구의 목적은 겨울철 약광기 보광 시 줄기 유인 수가 온실 파프리카의 생육, 과실의 품질 및 생산량에 미치는 영향을 구명하는 것이다. 파프리카는 2020년 10월 26일에 m 2당 3.2 주를 정식하였고, 2020년 12월 1일부터 고압나트륨등을 작기 종료일인 2021년 5월 25일까지 하루 16시간의 광주기로 조사 하였다. 줄기 유인 처리는 분지 이후의 생장점이 각각 2, 3개로 유지되도록 유인해 주었다. 초장은 2줄기 유인 처리구에 비해 3줄기 유인 처리구에서 유의적으로 짧았고 마디수 및 엽수는 2줄기 유인 처리구에 비해 3줄기 유인 처리구에서 유의적으 로 증가했다. 엽면적 및 기관별 건물중은 통계적으로 유의한 차이를 보이지 않았다. 과실 생체중 및 건물중은 모든 처리구에서 생육단계에 따라 감소하는 경향을 보였으며, 3줄기 유인 처리구가 2줄기 유인 처리구에 비해 낮은 수치를 보였다. 3줄 기 유인 처리구의 상품과율은 95.4%로 2줄기 유인 처리구의 93.6%에 비해 높았다. 총 수확량은 3줄기 유인 처리구에서 30.2% 높게 나타났다. 결론적으로 온실 파프리카의 3줄기 유인 재배는 적정 수준의 영양생장을 유지함으로써 과실 생산량에 긍정적인 영향을 미쳤다고 할 수 있다. 본 연구 결과는 파프 리카의 생산량 증대를 위한 농가 의사결정에 활용될 수 있을 것으로 사료된다.
        4,000원
        4.
        2019.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Plant growth and morphology are affected by light environments. The morphogenesis and growth of the plants growing in plant factories are different from those grown under sunlight due to the effect of far-red light included in sunlight. The objective of this study was to compare the morphogenesis and growth of cucumber plants grown under artificial sunlight, high pressure sodium lamp (HPS), and HPS with additional far-red light (HPS+FR). The artificial solar (AS) with a spectrum similar to sunlight was manufactured using sulfur plasma lamp, incandescent lamp, and green-reducing optical film. HPS was used as a conventional electrical light source and far-red LEDs were added for HPS+FR. The optical properties of each light source was analyzed. The morphogenesis, growth, and photosynthetic rate were compared in each light source. The ratio of red to far-red lights and phytochrome photostationary state were similar in AS and HPS+FR. There were significant differences in morphology and growth between HPS and HPS+FR, but there were no significant differences between AS and HPS+FR. SPAD was highest in HPS, while photosynthetic rate was higher at AS and HPS. Although the photosynthetic rate in HPS+FR was lower than HPS, the growth was similar in AS. It was because canopy light interception was increased by longer petioles and larger leaf areas induced by FR. It is confirmed that the electrical light with additional far-red light induces similar photomorphogenesis and growth in sunlight spectrum. From the results, we expect that similar results will be obtained by adding far-red light to electrical light sources in plant factories.
        4,000원
        5.
        2013.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was performed to estimate the salt content and evaluate the nutritional quality of free lunch meals served by welfare facilities for the elderly. We collected food items from 8 welfare facilities in Gyeonggi-do, and calculated the total salt content from the salinity and weight of individual food items. The average salt content from lunch meals was 5.68 g, which was over the recommended daily salt intake by the WHO. The greatest contributor to the salt content among the menu groups was soup and stew (37.5%). Soup, stew, deep-fried foods, and sauces were major sources of salt, while the most salty dishes were sauces, deep-fried food, salt-fermented food, and kimchi. The nutrient content was sufficient, except for calcium in both men and women, which was equal to approximately 1/3 of the dietary recommended intakes (DRIs) for Korean adults of their mean age. In addition, the index of nutritional quality (INQ) and nutrient adequacy ratios (NAR) of most nutrients were satisfactory, except for those of calcium and sodium. The INQs of calcium and sodium were 0.64 and 4.41, respectively, while the mean adequacy ratio of a meal was 0.95. These results suggest that multilateral efforts to lower sodium intake be considered and calcium sources be added, in order to improve the quality of meals served to the elderly at welfare facilities.
        4,200원
        6.
        2007.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 시험은 겨울철 광원별 보광처리에 따른 장미의 생육장태와 온실내의 온 습도 변화를 조사하기 위하여 수행하였다. 보광재료는 나트륨등과 형광등을 사용하였고, 처리는 야간에 5시간씩 하였고, 2회 수확하였다. 온실 내 온도는 보광시작 후 나트륨 등 보광처리가 높았으며, 슬라브내 온도는 오전 6시에 나트륨등으로 보광한 처리가 높게 나타났으며, 일일 평균습도는 나트륨 등 처리가 낮게 나타났다. 나트륨 등 처리시 장미 줄기의 인산, 칼륨, 칼슘, 마그네슘 함량은 다른 처리보다 많았고, 잎에서는 칼륨과 마그네슘 함량이 다른 처리보다 낮았다. 잎의 엽록소 함량은 처리간 차이가 없었다. 절화장과 줄기 직경은 다른 처리보다 나트륨 등 처리에서 양호하였다. 수량은 2회 모두 나트륨 등 보광에서 더 많이 나와 일조량이 부족한 겨울철에 나트륨 등으로 보광하면 장미 수량과 품질을 높일 것으로 생각된다.
        4,000원