• 한국환경농학회지
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• 제37권2호
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• pp.79-86
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• 2018

BACKGROUND: Chinese cabbage biosynthesizes various phytochemicals including carotenoids and glucosinolates. Environmental stress has a major effect on the growth and yields of vegetables, and can significantly affect nutritionally important phytochemicals. Phytochemicals of plants are influenced by light, temperature, carbon dioxide, and growing conditions. The aim of this study was to investigate the effect of various light sources on carotenoid and glucosinolate contents in Chinese cabbage. METHODS AND RESULTS: [Experiment I] Set the control (field control, FC) on the ground. Using acrylic sunlight, experiments were set up transparency box (field transparency, FT), red box (field red, FR) and blue box (field blue, FB). [Experiment II] Set the control (chamber control, CC) in the greenhouse. Using plant growth chamber with artificial light, experiments were set up LED red (chamber red, CR), LED blue (chamber blue, CB), LED mixed red+blue (chamber red+blue, CRB) and fluorescent (chamber fluorescent, CF). After plant growth, Chinese cabbage was harvested at 110 days after sowing (DAS). The status of plants growth (leaf length, width, fresh weight etc.) was immediately investigated. Carotenoid and GSL contents were analyzed by HPLC. [Experiment I] Results documented that the ranges of total carotenoid contents were 25.39 ~ 58.80 mg/kg dry wt for lutein, 0.84~ 4.22 mg/kg dry wt for zeaxanthin, and 3.85~18.71 mg/kg dry wt for ${\beta}$-carotene. Lutein was the highest for the content and the largest for the variation as well. [Experiment II] Results documented that the ranges of total carotenoid contents were 24.66~137.96 for lutein, 2.51~20.65 for zeaxanthin, and 8.40~49.80 mg/kg dry wt for ${\beta}$-carotene. The total carotenoid contents of CR (156.62) and CB (115.90) were 1.6~2.3 times larger than the other treatments, and ${\beta}$-carotene content was about twice as high as that of the other treatments on the CR (38.74 mg/kg dry wt.). [Experiment I] Total GSL content was the highest in FT (19.76) that was higher 1.7 times than the lowest treatment ($11.39{\mu}mol/g\;dry\;wt$.). [Experiment II] The total content of GSL was highest in CRB (4.19) and lowest in CF ($2.88{\mu}mol/g\;dry\;wt$.). In the CRB, total GSL contents ($4.19{\mu}mol/g\;dry\;wt$.) was the highest. CONCLUSION: Total and individual carotenoid and GSL contents in Chinese cabbage show significant differences under different light sources. Red and blue lights contribute to significant carotenoids expression and antioxidant activity for nutrition and health benefits. These results concluded that the introduction of varying lights affected the synthesis of important nutrient compounds in Chinese cabbage. It is predicted that the application of good light source enhances the accumulation of functional compounds.

• 한국식품과학회지
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• 제47권6호
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• pp.785-788
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• 2015

식품 저장 중 효소적 갈변을 일으키는 타이로시네이스의 활성을 저해시킬 수 있는 LED의 파장을 구명하기 위하여 파란색, 초록색, 빨간색 LED와 형광등을 이용하여 타이로시네이스에 7일동안 조사하였다. 또한 강도에 따른 타이로시네이스의 활성을 조사하기 위하여 파란색, 초록색, 빨간색 LED를 선택하여 빛의 강도를 3단계로 구분하여 사용하였다. 파장에 따른 타이로시네이스의 활성 저해율은 형광등에서 가장 컸으며 그 다음으로 파란색 LED에서 높은 저해율을 보였다. 빨간색 LED에서는 대조구와 유사한 저해율을 보였으며 초록색 LED에서 저해율이 가장 낮았다. 상대적 빛의 강도에 따른 타이로시네이스 활성은 초록색과 빨간색 LED 조사 시 효소활성의 변화가 크지 않았고, 반면 파란색 LED에서 강도가 증가할수록 큰 저해효과를 보였다. 이러한 결과를 토대로 볼 때 여러 가지 파장의 LED 중 고강도의 파란색 LED에서 타이로시네이스에 의한 식품의 갈변을 최소화 할 수 있을 것으로 판단되며 이는 갈변 억제를 유도함으로써 과일 및 채소의 저장 중 품질을 향상시킬 수 있을 것이다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.773-776
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• 2002

Efficient organic white light-emitting diodes are fabricated by doping [bis(2-methyl-8-quinolinolato) (tripheny-siloxy)aluminium (III)] (SAlq), a blue-emitting layer, with a red fluorescent dye of 4-dicyanomethylene-2-methyl-6-{2-(2,3,6,7-tetrahydro-1H,5H-benzo[i,j]quinolizin-8-yl)vinyl}-4H-pyran (DCM2). The incomplete energy transfer from blue-emitting SAlq to red-emitting DCM2 enables to obtain a balanced white light-emission. A device with the structure of ITO/TPD (50 nm)/SAlq:DCM2 (30 nm, 0.5 %)/$Alq_3$ (20 nm)/LiF (0.5 nm)/AI shows emission peaks at 456 nm and 482 nm from SAlq and at 570 nm from DCM2. The white light-emitting device shows an external quantum efficiency of about 2.3 %, a luminous efficiency of about 2.4 lm/W, and the CIE chromaticity coordinates of (0.32, 0.37) at 100 cd/m^2. A maximum luminance of about 23,800 cd/m^2. is obtained at 15 V and the current density of 782 mA/cm^2.

• 수산해양기술연구
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• 제21권1호
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• pp.35-40
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• 1985

색망지에 대한 돌돔과 능성어의 선택반응을 조사하기 위하여 적색, 황색, 녹색, 청색 및 흑색의 다섯가지 색망지를 사용하여 시어의 반응을 조사한 결과는 다음과 같다. 1. 수조내에 색망지를 설치하지 않고 백색 배경 하에서 조사하였을 때, 돌돔과 능성어는 양 가쪽 구간중 어느 한 쪽으로 편중하여 분포하는 경향은 나타나지 않았다. 2. 돌돔은 수조의 양 가쪽 구간에 색망지를 설치한 경우가 설치하지 아니한 때보다 중간 구간에 많이 모였으나, 능성어에서는 반대로 나타났다. 3. 돌돔이 많이 선택한 색망지의 순위는 황색, 흑색, 청색, 녹색, 적색의 순으로 나타났다. 4. 능성어가 많이 선택한 색망지의 순위는 녹색, 흑색, 적색, 청색, 황색의 순으로 나타났다.

• 한국전기전자재료학회논문지
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• 제37권5호
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• pp.486-493
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• 2024

Lighting has been used for a long time as a medium to convey brightness from darkness, and through incandescent lamps and fluorescent lamps, LED light sources have now become the standard in the lighting industry. Recently, the lighting equipment industry has been undergoing rapid digital transformation, starting with smart lighting, and is evolving into smart lighting customized for individuals and spaces through the development of IoT technology, cloud-based services, and data analysis. However, the blue light emitted from digital devices (computers, smartphones, tablets, etc.) or LED lights stimulates the melanopsin in the optic ganglion cells in the retina of the eye, which in turn stimulates the secretion of melatonin through the pineal gland, which regulates the secretion of melatonin. This can reduce sleep quality or disrupt biological rhythms. This interaction between blue light and melatonin has such a significant impact on human sleep patterns and overall health that it is essential to reduce exposure to blue light, especially in the evening. Human-centered lighting refers to lighting that takes into account the effects of light on the physical and mental areas, such as human activity and awakening, improvement of sleep quality, and health management. Many research institutes study the effects in the visible area and the non-visible area. By studying the impact, it is expected to improve the quality of human life. In this study, we plan to study ways to implement human-centered lighting by collecting sunrise and sunset data and linking commercialized LED packages and control devices with open-source hardware.

• Journal of Plant Biotechnology
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• 제35권3호
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• pp.215-221
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• 2008

소멸위기 식물인 덩굴용담을 재료로 기내 생장 및 발근에 미치는 광질 및 환기효과를 조사하였다. 무처리 혹은 환기가 가능한 2종의 배양용기에 신초를 배양한 다음 5가지의 서로 다른 광질 1) 형광등, 2) 100% 적색광(R), 3) 70% 적색광+30% 청색광(R7B3), 4) 50% 적색광+50% 청색광(R5B5), 및 5) 100% 청색광 하에서 4주간 배양하였다. 실험을 통해 얻은 주요 결과는 다음과 같다. 1. 발근율은 형광등과 적색광에서 $80{\sim}100%$로 높았고, 특히 환기 처리시 100%의 발근율을 보였다. 광질별로는 적색광이 절간신장을 촉진시키고 청색광은 억제하는 경향이었다. 전반적으로 환기처리 시 진녹색의 큰 잎으로 자랐고, 액아의 발달을 억제하여 1-2개의 우세줄기로 생장하였다. 2. 식물체의 총 생체중은 적색광과 청색광이 7:3의 비율로 혼합된 혼합광 R7B3에서 가장 높았고, 특히 환기처리 시 식물체 당 257.7 mg으로 가장 높았다. 식물체의 충실을 나타내는 건물율(dry matter)은 적색광에서 가장 낮았고, 청색광에서 15%로 가장 높았으며, 청색광의 비율이 높아짐에 따라 건물율이 높아지는 경향을 보였다. 3. 광질별 총 엽록소 함량은 환기처리 하의 혼합광 R7:B3 및 R5:B5에서 29.5 ${\mu}g/g$ FW와 31.2 ${\mu}g/g$ FW으로 각각 가장 높게 나타났다. 광합성에 관여하는 carotenoid 함량에 있어서도 모든 광질에서 환기 처리 시 높게 나타났다. 이상의 결과는 덩굴용담의 기내배양은 배양목적에 따른 광질의 선택이 중요한 요소이며, 발근을 위해서는 적색광을 처리함이 좋고, 건전한 식물체의 생장은 혼합광 R7:B3에서 양호한 것으로 나타났다. 특히 모든 광질 하에서 환기처리가 건전한 줄기생장 및 발근을 촉진하는 것으로 나타나 이 식물의 효율적인 기내생장을 위해서 반드시 고려해야 할 내용으로 관찰되었다.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2020년도 추계국제학술대회
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• pp.61-61
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• 2020

This experiment was carried out using artificial bed soil and LED in the plastic film house(irradiation time: 07:00-17:00/day). Seedlings(n=63 per 3.3 m²) of ginseng was planted on May 17, 2018. LED was combined with red and blue light in a 3:1 ratio and irradiated with different light intensity(40-160 µmol/m²/s). Average air temperature from April to September according to the light intensity test was 20.4℃-20.9℃. Average artificial bed soil temperature was 20.1℃-21.7℃. The test area where fluorescent lamp was irradiated tended to be somewhat lower than the LED irradiation area. The chemical properties of the test soil was as follows. pH levels was 6.6-6.7, EC levels 0.9-1.3 dS/m and OM levels 30.6-32.0%. The available P₂O₅ contents was 73.3-302.3 mg/kg. Exchangeable cations K and Ca contents were higher than the allowable ranges and mg content was high in the fluorescent lamp treatment. The photometric characteristics of LED light intensity are as follows. The greater the light intensity, the higher the PPFD(Photosynthetic Photon Flux Density) value, illuminance and solar irradiation. Fluorescent lamp treatment had high illuminance value, but PPFD and solar irradiation were lower than LED intensity 40 µmol/m²/s treatment. The photosynthetic rate increased(2.0-3.8 µmolCO²/m²/s) as the amount of light intensity increased, peaking at 120 µmol/m²/s, and then decreasing. The SPAD (chlorophyll content) value decreased as the amount of light intensity increased, and was the highest at 36.1 in fluorescent lamp treatment. Ginseng germination started on April 5 and took 14-17 days to germinate. The overall germination rate was 68.8-73.6%. The growth of aerial parts(plant height etc.) were generally excellent in the treatment of light intensity of 120-160 µmol/m²/s. The plant height was 41.9 cm, stem length was 24.1 cm, leaf length was 9.8 cm and stem diameter was 5.6 mm. The growth of underground part (root length etc.) was the best in the treatment with 120 µmol/m²/s of light intensity. Due to the root length was long(24.8 cm) and diameter of taproot was thick(18.7 mm), the fresh root weight was the heaviest at 24.8 g. There were no disease incidence such as Alternaria blight, Gray mold and Anthracnose. Disease of Damping-off caused by Rhizoctonia solani occurred 0.6-1.5% and incidence ratio of rusty root ginseng was 30.8-62.3%. It is believed that the reason for the high incidence of rusty root ginseng is that the amount of field moisture capacity of artificial bed soil is larger than the soil. Leaf discoloration rate was 13.7-32.3%.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1540-1545
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• 2004

Measurement of concentration fields in a micro-channel is the crucial technology in the area of Lab-on-a-chip to be used for various bio-chemical applications. It is wel-known that the only possible way to measure the concentration field in the micro-channel is using micro-LIF(Laser Induced Fluorescence) method. However, an accurate concentration field at a given cross plane in a micro-channel has not been made so far due to the limit of light illumination. The present study demonstrates a novel method to provide an ultra thin laser sheet beam having 5 microns thickness by a micro focus laser line generator. Nile Blue A was used as fluorescent dye for LIF measurement. The laser sheet beam illuminates an exact plane of concentration measurement in the micro-channel to increase the signal to noise ratio and reduce the depth uncertainty considerably.

• 센서학회지
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• 제21권6호
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• pp.429-433
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• 2012

In this paper, we reduced the optical noise interference in a visible light communication system using two color LEDs. In the transmitter, the original and the inverted signals of the transmitted data modulated a red LED and a blue LED, respectively. In the receiver, a differential detector which is composed of two photodetectors and an optical red filter detected the mixed signal radiated from the two LEDs. In an environment that the optical noise from a fluorescent lamp exists, the signal-to-noise ratio in this system was improved by about 20dB compared to that in the conventional system which uses a single LED and a single photodetector.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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• pp.23-23
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• 2003

GaN-related semiconductors are of great technological importance for the fabrication of optoelectronic devices, such as blue and ultra violet light emitting diodes (LEDs), laser diodes, and photo-detectors. One of the most important applications of GaN-based LEDs is solid-state lighting, which could replace incandescent bulbs and ultimately fluorescent lamps. For solid-state lighting applications, the achievement of high extraction efficiency in LED structures is essential. For flip-chip LEDs (FCLEDS), the formation of low resistance and high reflective p-GaN contact is crucial. So far, a wide variety of different methods have been employed to improve the ohmic properties of p-type contacts to GaN. For example, surface treatments using different chemical solutions have been successfully used to produce high-quality ohmic contacts, Metallization schemes, such as Ta/Ti contacts to p-GaN, were also investigated. For these contacts, the removal of hydrogen atoms from the Mg atoms doped n the GaN was argued to be responsible for low contact resistances.