• 농업과학연구
• /
• 제40권4호
• /
• pp.297-303
• /
• 2013

This study was carried out to examine the effect of Red LED (660 nm) and fluorescent lamp for night break (NB) treatments of each 3 hours (22:30-01:30), 4 hours (22:00-02:00) and 5 hours (21:30-:02:30) per day for 53 days on flower bud initiation and growth in Chrysanthemum cv. 'Baekma' and cv. 'Jinba'. The days to flower budding after short-day treatment in 'Baekma' was longer at fluorescent lamp 4 hr (21.0 days) and 5 hr (20.5 days) NB, and it was shorter at Red LED 3 hr (14.2 days). The days to flowering after short-day treatment in 'Baekma' was longer at fluorescent lamp 4 hr (54.0 days), 5 hr (53.5 days) NB, and Red LED 5 hr (53.3 days), and it was shortest at Red LED 3 hr (50.2 days) NB treatment among all treatments. The days to flower budding after short-day treatment of 'Jinba' was longer at fluorescent lamp 4 hr (20.6 days) and was shorter at Red LED 3 hr (14.1 days) among all treatments. Similarly, the days to flowering after short-day treatment of 'Jinba' was longer at fluorescent lamp 4 hr (55.3 days) and was shortest at Red LED 3 hr (50.2 days) among all treatments. Therefore, inhibition of flower bud initiation was the most effective under fluorescent lamp 4 hr treatment. The length of cut flower of 'Baekma' was increased by fluorescent lamp 4 hr, 5 hr, and Red LED 5 hr, but of 'Jinba' was longer at LED 4 hr and 5 hr treatment. The weight of cut flower of 'Baekma' was heaviest at fluorescent lamp 5 hr treatment and was at Red LED 5hr treatment for 'Jinba' even though there was not statistically significant difference between 'Baekma' and 'Jinba'. Consequently, under fluorescent lamp 4 hr for night break was the most effective on flower bud initiation, flowering inhibition and cut-flower characteristics in 'Baekma' and 'Jinba'.

• Journal of Animal Science and Technology
• /
• 제64권3호
• /
• pp.432-442
• /
• 2022

The purpose of this study was to analyse the effects of light colour on rabbit reproductive performance and the expression of key follicular development genes. Rabbits (n = 1,068, 5 months old, 3.6-4.4 kg live body weight) were divided randomly into four groups, housed individually in wire mesh cages and exposed to red, green, blue, and white light-emitting diode (LED) light (control). The lighting schedule was 16 L : 8 D-15 d / 150 lx / 6:00 am-22:00 pm (3 d preartificial insemination to 12 d postartificial insemination). Red light and white light affected the conception rate and kindling rate and increased the total litter size at birth (p < 0.05). The effects of red light on litter size at weaning, litter weight at weaning, and individual weight at weaning increased compared with the green and blue groups. The effects of red light on live litter size at birth were increased compared with those in the blue group (p < 0.05). Compared to white light, green and blue light reduced the number of secondary follicles (p < 0.05). Compared to red light, green and blue light reduced the number of tertiary follicles (p < 0.05). Compared with white light, red LED light resulted in greater ovarian follicle stimulating hormone receptor and luteinizing hormone receptor mRNA expression (p < 0.05). Compared with green and blue LED light, red LED light resulted in greater B-cell lymphom-2 mRNA expression (p < 0.05). Compared with green LED light, red LED light inhibited FOXO1 mRNA expression in rabbit ovaries (p < 0.05). Red light can affect the reproductive performance of female rabbits and the expression of key genes for follicular development.

• 한국수산과학회지
• /
• 제51권1호
• /
• pp.64-71
• /
• 2018

This study was conducted to investigate the effects of light intensity and wavelength on the growth of Tetraselmis suecica and Tetraselmis tetrathele. These species were exposed to a blue light-emitting diode (LED; max=450 nm), a yellow LED (max=590 nm), a red LED (max=630 nm) and a fluorescent lamp (three wavelengths). The maximum growth rates (${\mu}_{max}$) of T. suecica and T. tetrathele under a red LED were 1.12/day and 0.95/day, respectively. Under a yellow LED, growth rates were 70% of the values for red wavelength, with low half-saturation constants (Ks). The optimum light source to ensure economically effective and productive growth in a Tetraselmis culture system (Photo-Bioreactor) would thus appear to be a three-phase culture, wherein a yellow LED is used during the lag phase and initial exponential phase to increase growth rate, followed by a red LED during the middle exponential phase to maximize growth rate, and finally a yellow LED again during the late exponential phase and stationary phase to achieve increased yield of useful bioactive substances.

• 식물조직배양학회지
• /
• 제27권1호
• /
• pp.71-75
• /
• 2000

발광다이오우드 (Light emitting diode)를 사용한 적색, 녹색 및 청색광에서 식물생산의 가능성을 조사하기 위하여 도라지 유묘의 생장과 형태형성에 미치는 광질의 효과와 광질에 따른 엽록소함량을 형광등과 비교하여 조사하였다. 식물체의 초장은 형광등에서 3.8 cm로 가장 짧았고 LEDs 에서 생장한 것은 적색광에서 13.4cm로 가장 길었다. 반면에 적색/청색의 혼합광은 5.6cm로 적색 단색광에서 식물체가 도장된 것에 비해 정상적인 식물체의 생장양상을 보여 적색과 청색의 혼합광이 식물체의 생장에 적당하였다. 엽면적은 녹색광에서 24.1 $\textrm{cm}^2$로서 적색광에서 10.1 $\textrm{cm}^2$인 것에 비하여 약 2.4 배가 더 넓어 다른 처리구에 비하여 가장 양호하였다. 건물률은 적색/청색의 혼합광에서 15.3%를 나타내어 다른 광질처리보다 함수율이 적었다. 엽록소함량은 청색 단색광과 적색/청색의 혼합광에서 형광등보다 각각 20%, 10% 적었으나 적색과 녹색의 경우 각각 2%, 7% 적었는데 적색 단색광에서 형광등과 비슷한 엽록소 함량을 보였다.

• 전자공학회논문지 IE
• /
• 제46권3호
• /
• pp.12-18
• /
• 2009

본 논문은 LED 디스플레이 시스템에서 균일하고 부드러운 영상표출을 위하여 각각의 Red, Green, Blue LED의 휘도를 조절하여 흰색보정을 유지할 수 있는 프로세서를 설계하였다. 이 프로세서는 일반적인 LED소자의 특성곡선을 근거로 "a"를 고유특성 값, "b"를 사용시간에 따른 휘도보정 값, "X"를 구동전류 값, "Y"를 휘도 값이라 할 때, "Y=aX+b"로 설정되는 휘도 특성함수에 의하여 각 픽셀의 휘도에 따른 구동 전류 값을 산출하여 휘도를 보정하고, 또한 장시간 사용 시 LED소자의 휘도 저하 문제를 해결하기 위하여 "b"값을 조절하여 LED 디스플레이 시스템의 전체 평균 휘도 값을 상향시킬 수 있도록 구현하였다.

• 생물환경조절학회지
• /
• 제18권4호
• /
• pp.370-376
• /
• 2009

폐쇄형 육묘시설 내에서 균일한 품질의 플러그묘를 주년으로 생산함에 있어서 LED 광원의 이용 가능성을 검토하기 위하여, 토마토와 오이의 육묘기간 동안에 광원을 달리하여 묘소질을 비교하였다. 적색, 청색, 혼합(적색 2 + 청색 1) LED 및 형광등을 $40{\sim}60{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$로 광도(PPF)를 조사하여 30일간 온도조절이 가능한 폐쇄형 육묘시스템에서 육묘하였다. 토마토와 오이 모두 형광등에 비해 적색 LED와 혼합 LED 처리에서 배축의 신장이 작으면서 튼튼한 묘을 생산할 수 있었다. 토마토와 오이의 생체중은 적색 LED에서 가장 무거웠는데 형광등에 비하여 각각 74% 증가하였다. 토마토의 1화방 착과절위에서는 처리간에 차이가 없었으나, 2화방의 착과절위는 혼합광 처리에서 낮았다. 화방별 착화수는 처리간에 차이가 없었다. 오이의 20절까지의 암꽃 착생률은 적색 LED 처리에서 52%로 가장 높았고, 다음이 혼합광 처리로서 44%였다. 과실 착과수와 수량은 처리간에 차이가 없었다. 이상의 결과로부터 폐쇄형 육묘시설 내에서 토마토와 오이의 묘생산에는 적색 및 적색 2 +청색 1의 혼합 LED가 이용 가능성이 높은 것으로 판단하였다.

• 한국산림과학회지
• /
• 제95권6호
• /
• pp.716-722
• /
• 2006

Eucalyptus pellita 기내줄기를 재료로 광질에 따른 생육 특성을 조사하였다. 전반적으로 줄기의 생장은 광질보다는 환기처리가 더 주요한 요인으로 나타났다. 특히 환기처리 한 청색광(blue LED) 하에서 묘고, 잎수, 절간수 및 액아수가 양호하였고, 잎에 캘러스가 형성되지 않았다. 식물체의 충실정도를 나타내는 건물율 역시 환기처리 하에서 높게 나타났으며, 청색광 하에서 가장 높은 건물율을 나타냈다. 광질별 총엽록소 함량은 형광등과 혼합광 R5B5(50% red LED + 50% blue LED)에서 $24.5{\mu}g/g$ 및 $20.1{\mu}g/g$으로 가장 높게 나타났다. 광합성에 관여하는 카로티노이드 함량 역시 적색광(red LED)을 제외한 모든 광질에서 환기 처리 시 양호하게 나타났다. 결론적으로 E. pellita의 기내 줄기생장은 환기처리가 중요하고, 총 카로티노이드 함량을 기준으로 볼 때 혼합광 R5B5에서 건전한 줄기생장이 가능한 것으로 나타났다.

• Journal of Biosystems Engineering
• /
• 제39권2호
• /
• pp.87-95
• /
• 2014

Purpose: The purpose of this study was to design a variable frequency LED light system for plant factory which combined red, blue, green, white, and UV lights and controlled the ratio of the light wavelength. In addition, this study evaluated the performance of each combination of LED to verify the applicability. Methods: Four combinations of LED (i.e. Red+Blue, Red+Blue+Green, Red+Blue+White, Red+Blue+UV) were designed using five types of LED. The system was designed to control the duty ratio of each wavelength of LED by 1% interval from 0~100%, the pulse by 1Hz interval from 1~20kHz. Response characteristics of the control system, spectral distribution of each combination, light uniformity and uniformity ratio were measured to test the performance of the system. Results: Clean waveforms were measured from 10Hz to 10kHz regardless of duty ratio. Frequency distortion was observed within 5% of inflection point at frequencies above 10kHz regardless of duty ratio, but it was judged negligible. Spectra showed a normal distribution, and maximum PPF with duty ratio of 100% was $271.4{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ for the Red+Blue combination. PPF of the Red+Blue+Green combination was $258.9{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, and that of the Red+Blue+White combination was $273.9{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. PPF of the Red+Blue+UV combination was $267.7{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Uniformity ratio for the area excepting border showed 0.90 for the Red+Blue and Red+Blue+White combinations, 0.87 for the Red+Blue+Green combination, and 0.88 for the Red+Blue+UV combination. The light was irradiated evenly at the area excepting border, so it was suitable for plant growing. Conclusions: From the results of this study, response characteristics of the control system, spectral distribution of each combination, light uniformity and uniformity ratio were suitable for applying into the plant factory.

• 한국잠사곤충학회지
• /
• 제52권1호
• /
• pp.59-63
• /
• 2014

최근 다양한 파장의 LED를 이용한 작물의 생장과 기능성 물질의 변화에 대한 연구가 활발히 진행되고 있다. 본 연구에서는 LED 조사가 눈꽃동충하초 생산에 미치는 영향을 알아보고자, 청색LED, 적색LED, 형광등 아래에서 눈꽃동충하초를 재배하여, 자실체 형성율, 자실체 개수, 자실체 길이 등을 관찰하였다. 그 결과, 적색 LED 광에서 재배한 눈꽃동충하초의 자실체 발생율은 100%에 달하였으며, 뿐만 아니라 형성된 자실체의 개수가 37%까지 증가하는 등 자실체 무게, 자실체 길이 등 모든 항목에서 우수한 결과를 보여주었다. 하지만 청색 LED광에서는 오히려 생육을 저해하는 결과를 나타내었다. 따라서, 눈꽃동충하초 재배 시, 적색 LED를 조사한다면 농가의 소득 향상에 도움을 줄 것으로 여겨진다.

• 한국환경과학회지
• /
• 제33권5호
• /
• pp.305-322
• /
• 2024

The aim of this study was to investigate the effects of artificial light sources on the germination and seedling vigor of lettuce, aiming to identify the optimal artificial light source for producing high-quality seedlings. Lettuce cultivar of 'Tomalin' and 'Seonpunggold' exhibited the highest seed emergence in the Metal halide(MH) lamp and High-pressure sodium(HPS) lamp treatment group, while the emergence rate parameter, T50, was the fastest in the HPS lamp treatment group. Both cultivars showed good growth characteristics such as number of leaves, root length, and stem diameter under RGB-LED, and their seedling vigor was excellent as well. The plant height was smallest in the Red + Green + Blue LED treatment, but the leaves were round and thick, resulting in higher biomass and dry weight. Single light sources of Red LED and Blue LED led to reduced growth compared with that under the mixed light treatments. Chlorophyll content in lettuce varied with the type of artificial light, with both cultivars exhibiting the highest chlorophyll content in the Red + Green + Blue LED treatment. The most suitable artificial light for lettuce seedling growth was the Red + Green + Blue LED treatment.