• 한국지반환경공학회 논문집
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• 제13권2호
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• pp.41-47
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• 2012

본 연구는 담수미세조류의 일종인 클로렐라를 적색 발광다이오드를 이용하여 효율적으로 배양하기 위한 조건을 찾기 위해 수행되었다. 클로렐라 배양에 최적인 광량을 찾기 위해 광량을 조절하여 클로렐라가 포함된 반응기에 각각 조사하여 성장속도 및 셀농도를 측정하였다. 적색파장 사용 시, 광량이 증가할수록 성장속도는 광량에 비례하여 증가하였으나 셀농도는 지속적으로 감소하였다. 공기 공급에 따른 성장특성을 살펴보기 위해 반응기에 미세공기를 연속적으로 주입하였는데, 반응속도 및 셀농도는 공기를 주입하지 않은 경우에 비해 2배와 10배 증가함을 알 수 있었다. 고농도의 이산화탄소 주입의 경우에는 배지의 pH가 3이하로 저하되어 클로렐라의 성장이 감소하는 것을 알 수 있었다. 본 연구를 통해 클로렐라를 효과적으로 배양하기 위해서는 적색파장의 발광다이오드를 광원으로 사용하고 반응기에 공기를 연속적으로 주입하는 것이 효과적임을 알 수 있었다.

• 한국환경농학회지
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• 제31권3호
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• pp.224-228
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• 2012

적색 LED를 이용한 들깨의 개화억제를 위한 일장연장처리 기술을 개발하기 위하여 적색광에 대한 들깨의 개화와 생육반응을 검토하였다. 들깨는 적색광에 의한 일장연장 처리로 개화가 억제되었으나 초적색광 조사로 개화하여 광가역성을 나타냈다. 인공생육실 환경하에서 적색광 $0.177{\mu}mol/m^2/s$ (PAR : $0.62{\mu}mol/m^2/s$)로 일장연장 처리시 들깨의 개화가 억제되었다. 비닐하우스 시험포장에서 적색광 $0.2{\mu}mol/m^2/s$ 처리(PAR : $0.7{\mu}mol/m^2/s$)는 관행의 백열등 30 Lux 처리와 같이 개화하지 않고 영양생장을 지속하였다. 적색 LED장치를 이용한 일장연장 처리는 관행의 백열등 처리보다 들깨의 초장은 3%, 엽수는 7%, 엽생체중은 21%, 엽면적은 19% 증가시키는 경향이었다.

• Korea-Australia Rheology Journal
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• 제16권3호
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• pp.129-134
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• 2004

The aggregation characteristics of red blood cells (RBCs) were measured using a newly developed light-transmission slit rheometer. Conventional methods of RBC disaggregation such as the rotational Couette system were replaced with a pressure-driven slit flow system with a vibrational mechanism. Using a vibration generator, one can disaggregate the RBC aggregates stored in the slit. While shear stress decreases exponentially, instantaneous pressure and the transmitted light intensity were measured over time. Applying an abrupt shearing flow after disaggregation caused a rapid elongation of the RBCs followed by loss of elongation with the decreasing shear stress. While the shear stress is further decreasing, the RBCs start to re-aggregate and the corresponding transmitted intensity increases with time, from which the aggregation indices can be obtained using a curve-fitting program.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1678-1681
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• 2004

The light-transmission technique has been applied to a slit rheometer for measuring red blood cell aggregation as well as blood viscosity over a range of shear rates. For measurement of blood viscosity and aggregation, instantaneous pressure and transmit-light intensity are measured with time. Using a precision pressure measurement, one can determine the shear stress and shear rate. In addition, a transmitted light through a blood sample indicates degree of RBC aggregation. With abruptly flowing with high shear rate, RBCs rapidly disaggregate and the intensity of the transmitted light becomes low. When continuously flowing with decreasing shear rate, RBCs tend to re-aggregate and the corresponding transmit-intensity gradually increases with time. The light intensity as a degree of RBC aggregation is plotted against shear rate and compared with blood viscosity. The advantages of this design are dual measurement at a time, simplicity, i.e., ease of operation and no moving parts, low cost, short operating time, and the disposable kit which is contacted with blood sample.

• KSBB Journal
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• 제28권3호
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• pp.170-176
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• 2013

The purpose of this study was to determine optimum condition of Pavlova lutheri and Phaeodactylum tricornutum. Detailed studies were carried out on the effects of various wavelengths of light-emitting diodes (LEDs), light intensities and air flow rations. For the Pa. lutheri, cell growth rates and maximum cell concentrations were similar regardless of wavelengths and air flow rates. Among the different light intensities, cell concentration increased when light intensity of red LED increased. For Ph. tricornutum, red LED was found to be the most effective light source, and light intensity of 3,100 Lux resulted in the most effective for the cultivation of Ph. tricornutum. Different air flow rates were tested to overcome shading effects due to denser cell concentration in the solution. Aeration of 0.8 vvm was determined to be the optimum aeration rate for the cultivation of Ph. tricornutum. Especially, five and two times greater cell concentrations of Pa. lutheri and Ph. tricornutum, respectively, were observed when air was applied.

• 한국조경학회지
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• 제33권4호
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• pp.119-128
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• 2005

This study was carried out to obtain fundamental information of growth response of interior landscape plants under a fluorescent lighting, a sunlight at indoor. Ficus elastica Roxb. vu. decora Hort, Spathiphyllum 'Clevelandii', Codiaeum variegatum Blume var. pictum Mvell. Arg. 'Exalant' and Cordyline terminalis Kunth var. red edge Hort were examined under 100lux, 500lux, 1,000lux and 2,000lux light intensity consisted of fluorescent lighting and sunlight at indoor condition. Result of experiments are as follows; 1. A Ficus elastica Roxb. var. decora Hort plant growth status was better showed under fluorescent lighting than sunlight. A plant growth status showed the best result under 2,000lux light intensity of fluorescent lighting in cases of all conditions. 2. A Spathiphyllum 'Clevelandii' showed the best effective adaptations under law intensity among experimental plants. A Spathiphyllum 'Clevelandii', plant growth status was better showed under fluorescent lighting than sunlight. A plant growth status showed the best result under 1,000lux light intensity of fluorescent lighting in cases of all conditions. 3. It need the best high establishment of fluorescent lighting among experimental plants for good plant growth. A Codiaeum variegatum Blume var. pictum Mvell. Arg. 'Exalant' plant growth status was better showed under fluorescent lighting than sunlight. A plant growth status was better showed under high light intensity in case of same light source. A plant growth status showed the best result under 2,000lux light intensity of fluorescent lighting. 4. A Cordyline terminalis Kunth var. red edge Hort plant growth status was better showed under fluorescent lighting than sunlight. but, A plant growth status was better showed under $500lux\sim1,000lux$ than 2,000lux in cases of all intensity of fluorescent lighting. while, A plant growth status was better showed under $1,000lux\sim2,000lux$ in cases of all intensity of sunlight.

• 한국환경농학회지
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• 제30권4호
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• pp.382-389
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• 2011

BACKGROUND: Light-emitting diodes (LEDs) with lower electric cost and the specific wavelength have been considering as a novel light source for plant production in greenhouse conditions as well as in a closed culture system. Supplementary lighting for day-length extension was considered as light intensity, light quality, and/or photoperiod control on plant growth and development. Effects of supplementary blue or red LED radiation with lower light intensity on growth of Ageratum (Ageratum houstonianum Mill., cv. Blue Field), African marigold (Tagetes erecta L., cv. Orange Boy), and Salvia (Salvia splendens F. Sello ex Ruem & Schult., cv. Red Vista) were discussed during sunrise and sunset twilight in the experiment. METHODS AND RESULTS: Supplementary lighting by blue and red LEDs for 30 (Treatment B30; R30) or 60 (Treatment B60; R60) min. per day were established in greenhouse conditions. Photosynthetic photon flux for supplementary radiation was kept at $15{\mu}mol\;m^{-2}\;s^{-1}$ on the culture bed. Natural condition without supplementary light was considered as a control. The highest shoot and root dry weights were shown in African marigold exposed by red light for 60 min. per day. Supplementary blue and red lighting regardless of the radiation time significantly stimulated development of lateral branches in African marigold. Stem growth in Ageratum and Salvia seedlings was significantly promoted by red radiation as well as natural light. CONCLUSIONS: Extending of the radiation time at sunrise and sunset twilight using LEDs stimulated reproductive growth of flowering plant species. Different characteristics on growth under supplementary blue or red lighting conditions were also observed in the seedlings during supplementary radiation.

• 한국환경농학회지
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• 제30권4호
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• pp.414-418
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• 2011

우리나라에서 주로 사용되고 있는 흑색 비닐멀칭과 신개발된 적색 비닐멀칭의 표면 반사광 특성을 분석하고 참외와 토마토에 대한 영향을 구명하여 작물생산에 대한 적용 가능성을 검토하였다. 적색 비닐멀칭의 표면에서 반사된 적색광과 초적색광의 일일 누적 강도는 흑색 비닐멀칭보다 2.6배 강했다. 적색광과 초적색광 반사광의 강도는 적색 비닐멀칭의 표면 높이 30 cm에서 가장 강하였다. 일중 태양광 강도가 강한 오후 1시 20분의 흑색 비닐멀칭의 Red/F-Red는 1.14, 적색 비닐멀칭은 0.93, 태양광은 1.16으로 적색 비닐멀칭이 흑색 비닐멀칭보다 초적색광 강도가 높았다. 적색 비닐멀칭의 Red/F-Red는 표면 높이 30 cm에서 가장 낮았으며 표면높이가 높아질수록 초적색광 강도가 감소하여 Red/F-Red는 증가하였다. 적색 비닐멀칭 반사광의 Red/F-Red는 정오부터 오후 4시경까지는 흑색 비닐멀칭보다 낮게 경과하였다. 흑색 비닐멀칭 처리구보다 적색 비닐멀칭 처리구의 참외 과실의 무게가 증가하여 수량이 증가하였고 당도가 높았다. 토마토의 과실 무게와 당도도 적색 비닐멀칭 처리가 흑색 비닐멀칭 처리구보다 높았다. 지중온도는 적색 비닐멀칭 처리가 흑색 비닐멀칭 처리보다 다소 낮은 경향이었다. 따라서 적색 비닐멀칭으로 토양을 피복하면 작물생산에 적색광과 초적색광을 더 많이 이용할 수 있을 것으로 판단된다.

• The Korean Journal of Ecology
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• 제14권1호
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• pp.87-99
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• 1991

Changes of phycobiliproteins(PBP) quantity and ferredoxin-NADP reductase(FNR) activity were investigated in various light illuminated cyanobacteria, Anabaena variabilis. PBP components were increased under blue light illumination, whereas decreased under red light illumination. PBP contents were twofolds in blue light than in red light. In view of the PBP composition, allophycocyanin(APC) in red light was higher 5.5% and phycoerythrocyanin(PEC) in blue light was higher 2.2% than in white light-illuminated PBP. It was suggested that PBP changes in bule light be the results of regulation of photosysthetic efficiency and protection of photosystem, whereas PBP changes in red light be effected by adaptation of adequate harvesting of light energy in photosystem. Changes of FNR activity were highest in red light, and sequenced lower to blue light and green light. It means that light-dependent production rate of NADP is the highest in red light. The difference of values was larger than that of values in comparison of red and blue light. It was suggested that increasing of FNR activity be due not to the function of isozyme, but to the synthesis of enzymes. Because of NAD/NADP regulation-effect to metabolism, it was considered that FNR activity might influence the metabolism indirectly and explain the probability of regulation in pathways of key enzyme activation. FNR activity was directly proportional to intensity of light. Optimum temperature and pH were about 25℃ and 7.5, respectively.

• 한국수산과학회지
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• 제51권1호
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• pp.64-71
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• 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.