• 한국환경복원기술학회지
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• 제7권1호
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• pp.110-115
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• 2004

This experiment was conducted to investigate the effect of light intensities on the growth responses, carbohydrate contents and the characteristics of leaf gas exchange in Miscanthus sinensis and Pennisetum purpurascens. The plant height and leaf length were increased to about 30% in the sun. However, those were reduced severely in the shade, and leaf necrosis was also observed. The representative growth index and the dry weight of 2 species were 50% higher than shade and the rate was reduced according to the decrease of light intensities. Total carbohydrate contents showed very similar changes to that of dry weight. However, any notable influences were observed at above the light intensities of 250~500${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ in the half shade. The size of spikes and the earliest spiking appeared in the sun and the spike color was decolorized as decreased in light intensities, irrespective of species. Photosynthetic rate of 2 species was 2 times higher in the sun than those in the shade, and it showed the typical photoresponses of sun plant. Stomatal conductances and intercelluar $CO_2$ concetration showed similar changes to that of photosynthetic rate. On the contrary, vapor pressure deficit was increased more in the shade than in the sun.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2020년도 춘계학술대회
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• pp.63-63
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• 2020

This study investigated the growth of native ferns under indoor light intensities to identify the introduction possibility as in-door ornamental plants. Three evergreen perennial fern species used in this experiment were Coniogramme japonica (Thunb.) Diels, Woodwardia japonica (L. f.) Sm., and Cyclosorus acuminatus (Houtt.) Nakai ex H. Itô. The light intensities were adjusted to 10, 50, 100 and 200 PPFD (µmol·m^-2·s^-1) based on the measurement of the various indoor light quantities. The experiment was conducted for a total of 8 weeks, and the light period (12/12h), temperature (25±1℃), and humidity (55±3%) were maintained during the experiment. The control plant group was grown in glass greenhouse for the same period. As the result of the study, in door C. japonica showed better growth under light intensities of 100, 200 PPFD. However, withering of the plants were observed under all light intensities except the control, which causes an ornamental value decrease. This seems to be related to the increase of DIo/RC value in chlorophyll fluorescence parameters. In the W. japonica growth data, the plant height was not significantly different from the control but, the leaf number decreased more than a two-fold. Also, the formed leaves turned brown and showed a poor growth and SPAD value at 200 PPFD had decreased significantly. Growth data of C. acuminatus was not significantly different with the control at all light intensities however, withering was observed at 100 and 200 PPFD. In chlorophyll fluorescence parameters, significant decrease in Pi_Abs and increase in DIo/RC value at 200 PPFD impose that stress caused by the intense light might be the reason of the withering of the plants.

• Journal of Photoscience
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• 제9권2호
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• pp.364-366
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• 2002

Photoadaptation of Chlorobium (Cb.) phaeobacteroides was investigated under dim and strong light intensity. Absorption spectra of these whole cellIs were different each other. The Soret band intensity and the Qy bandwidth of BChl e in c디l grown under dim light intensity were smaller and more broadened than those under strong light intensity. From HPLC analysis of the pigments, total carotenoid (Car) / bacterochorolphyll (BChl) e ratio of cell increased wi1h increase of light intensities. But camposition of BChl e hamologs almost unchanged. Cb. phaeobacteroides contains 11 kinds of Car including isorenieratene and beta-isorenieratene as major Car. The campositions of Car were different for cells grown under dim and strong light intensities. In conclusion, Cb. phaeobacteroides changes total amount and canposition of Car to adapt various light intensities, while homolog canposition of BChle unchange.

• Journal of Microbiology and Biotechnology
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• 제11권6호
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• pp.1024-1030
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• 2001

The key factors for high-density Haematococcus pluvialis cultures and conditions for astaxanthin induction were examined to maximize astaxanthin production. Light intensity was found to be the most important factor, and thus experiments were found to be the most important factor, and thus experiments were carried out using different light sources and intensities. A high cell density of over 2.7 g/l was obtained at $75{\mu}E/m^2/s$, whereas a much lower cell concentration (<1.0 g/ 1) was obtained with lower light intensities $(15-30{\mu}E/m^2/s$. A high light intensity and the supplement of 470 nm photons had a more dramatic effect on the final astaxanthin concentration and per cell astaxanthin content. A maximum astaxanthin concentration of 6.5 mg/l was obtained at a light intensity of $160{\mu}E/m^2/s$, whereas only 1.3 and 0.7 mg/l were obtained at 30 and $15{\mu}E/m^2/s$, respectively. A supplement of 470 nm photons enhanced the carotenoid and chlorophyll formation.

• 한국초지조사료학회지
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• 제8권1호
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• pp.61-65
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• 1988

To examine the effects of light intensity on photosynthesis, corn and sorghum species were grown under shade cloths, which reduced light intensity by 25,50 and 75%. Photosynthetic rates were measured between 10 a.m. to noon on a clear day in early and mid - summer. 1. The degree of shading had a little effect on microenvironment. Air, soil and leaf temperatures were reduced as shade increased. 2. The degree of shading in early summer had relatively a little effect on photosynthesis of corn. However, the rates of photosynthesis in mid-summer decreased by 36%, 55% with relative light intensities of 50% and 25%, respectively. 3. The rate of photosynthesis was highly correlated with light intensity. The rates of photosynthesis with relative light intensities of 75,50 and 25% were decreased by 20, 40 and 5 4% in early summer, and by 17-53%, 36-64% and 5570% in mid-summer, respectively. 4. The 75% of light intensity had relatively little effect on dry matter yield of corn and sorghum species, however dry matter yield with 50 and 25% relative light intensities was decreased 17 and 36% in corn, 13-3 1 and 50-68% in sorghum species, respectively.

• 융복합기술연구소 논문집
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• 제1권1호
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• pp.29-33
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• 2011

This study is performed to investigate the effect of the artificial light for room lightening. To do that, the experiments were done using the black room with 1m3 and performed to show the effect of the length between the room and light source and light intensities as LUX. The LUX of 18 sites in the room was measured using LUX meter. The length between the room and the light source was chosen as 500mm, 1000mm, and 1500mm and the light intensities was 3 levels. The results were shown the distinct difference between the part directly projected through the light path and non-directly projected. So, the light delivery path have to be modified for next step research. The results were very sensitive for the part directly projected through the light path. This study showed the basic results for room lightening using light source to simulate the solar lightening and was worth in a strict sense as fundamental study.

• 한국환경복원기술학회지
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• 제11권6호
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• pp.73-80
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• 2008

본 연구는 남부상록수종 중 내음성과 내한성이 강하고 자생 송악(Hedera rhombea)에 대한 적정 실내광원과 광도를 알아보고자 가로 1m${\times}$세로 1m${\times}$높이 1m 크기의 목제프레임에서 실험을 실시하였다. 광원의 선정기준은 현재 지하철에 가장 많이 활용되는 인공광인 형광등, 삼파장형광등, 할로겐등으로 하고, 광도는 200Lux, 700Lux, 1,000Lux로 설정하여 실험을 실시한 결과는 다음과 같다. 1.송악(Hedera rhombea) 초장은 광원과 광도별 뚜렷한 통계적 유의성이 나타나지 않았으나, 할로겐등>형광등>삼파장형광등 순으로 광도별로는 1,000Lux>700Lux>200Lux 순으로 길었다. 분지수는 형광등이 삼파장형광등이나 할로겐등보다, 광도가 높을수록 많아지는 경향을 보였다. 엽수는 삼파장형광등 1,000Lux>형광등 1,000Lux>할로겐등 1,000Lux 순으로 나타났다. 엽장과 엽폭은 광원에 관계없이 광도가 낮을수록 넓어지는 경향을 나타났다. 엽록소함량은, 삼파장형광등과 할로겐등은 광도에 따른 차이를 볼 수 없었으나, 형광등에서는 200Lux>700Lux>1,000Lux 순으로 증가되었다. 송악의 전체적인 생육은 인공광원보다는 광도에 의해 확연한 차이를 보여, 지하철 실내식물로 200Lux라는 낮은 광도에서도 도입이 가능하나 원활한 생육을 위해서는 700Lux 이상으로 광도를 조절하는 것이 바람직하다. 2. 바위취(Saxifraga stolonifera)형광등이 광원인 경우, 광도와 무관하게 80% 이상이 고사하거나 생육 상태가 좋지 않았다. 광도가 200Lux에서는 광원에 무관하게 생육 상태가 매우 불량하였다. 초장, 엽수, 분지수, 엽장, 엽폭 등 생육은 할로겐 1,000Lux>삼파장형광등 1,000Lux>삼파장형광등 700Lux순으로 증가하였다. 엽록소함량은 삼파장형광등 700Lux>삼파장형광등 1,000Lux>할로겐등 1,000Lux순으로 높았다. 따라서, 본 실험에서 바위취는 할로겐등에서 가장 좋은 생육을 나타내었으며, 형광등의 광원과 700Lux 이하 광도에서는 현장적용이 불가능한 수종임이 확인되었다.

• 센서학회지
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• 제20권4호
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• pp.221-225
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• 2011

Intensity-based optical fiber sensors are devised using a blocker which is located between two polymer optical fibers(POFs), one fiber is light-in and the other is light-out. This blocker is moved by an external displacement. Therefore, finding a general formulation of the relation between this displacement and transmission light intensity of various blockers is important to help develop intensity-based optical fiber sensors. In this paper, we consider blockers with arbitrary shapes from circular holes to inclined angled blockers. The transmission light intensities of such blockers should be determined by this generalized equation. In order to verify this equation, the calculated intensities of the blockers are compared with the values acquired from experiment. In the comparison, it is shown that the analytic equation can give the exact values of the transmitted light intensities for the assorted blockers. The range of the displacement measurement is also shown to be about 6 times of the radius of the hole in the case of a 9 degree inclined angle blocker.

• Animal Bioscience
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• 제36권5호
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• pp.731-739
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• 2023

Objective: This study was to evaluate the interaction of three different light-emitting diode (LED) light colors (white, green, and blue) and three intensities (5, 10, and 15 lx) on slaughter performance, meat quality and serum antioxidant capacity of broilers raised in three-layer cages. Methods: A total of 648 (8-days-old) male broiler chicks (Cobb-500) were randomly assigned in 3×3 factorially arranged treatments: three light colors (specifically, white, blue, and green) and three light intensities (namely, 5, 10, and 15 lx) for 35 days. Each treatment consisted of 6 replicates of 12 chicks. The test lasted for 35 days. Results: The semi-eviscerated weight percentage (SEWP) in 5 lx white was higher than that in 15 lx (p<0.01). The eviscerated weight percentage (EWP) (p<0.05) and water-loss percentage (WLP) (p<0.01) decreased in 10 lx white light than those in green light. Under blue light, the content of hypoxanthine (Hx) in muscle was lower than that under white and green light (p<0.01). The content of malondialdehyde (MDA) in 15 lx blue light was higher than that in 10 lx green light (p<0.05). Light color had an extremely significant effect on thigh muscle percentage, WLP, Hx, and crude protein content (p<0.01). Light intensity had a significant effect on SEWP (p<0.05), EWP (p<0.05), lightness (L^*) value (p<0.05), WLP (p<0.01), and the contents of superoxide dismutase (p<0.05), MDA (p<0.01), glutathione peroxidase (p<0.01). Conclusion: Using white LED light with 10 lx light intensity can significantly improve the chicken quality of caged Cobb broilers, improve the content of inosine acid in chicken breast and enhance the antioxidant capacity of the body. We suggest that the broiler farm can use 10 lx white LED light source for lighting in 8 to 42 days.

• 임산에너지
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• 제22권3호
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• pp.20-28
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• 2003

참나무류 주요 수종을 대상으로 다양한 광선 조건에 식재된 실생묘의 활착 및 상대생장량과 광선에 대하여 민감하게 작용하는 엽록소 함량의 계절적인 변화를 조사하기 위하여 상수리나무 1-1묘, 1-0묘, 신갈나무 1-0묘, 졸참나무 1-0묘, 굴찬나무 1-0묘를 상수리나무 임분내에 상층임분 밀도를 자연광의 81%, 34%, 21% 등 3가지로 조절하였다. 조사대상 수종의 묘목을 20m x l0m 크기의 시험구에 100본씩 식재하여 활착율, 상대생장량, 엽록소 함량을 비교하였다. 상수리나무 1-1묘가 평균 73%로 다른 수i종에 비해 높은 활착율을 보였고, 상수리나무 1-0묘가 66%, 신갈나무와 졸참나무가 각각 56%, 45%였으며, 굴참나무는 41%로 이식후 활착율이 가장 낮게 나타났다. 또한 자연광의 81% 실험구에서 대부분의 주요 참나무류 수고, 근원경 생장이 가장 좋은 경향을 보여 주고 있었으며 자연광의 21% 실험구에서는 오히려 광도가 낮아지면서 생장이 상대적으로 저해되는 경향을 보여 주고 있다. 엽록소 함령(a, b, 총엽록소 함향)은 광도가 낮아지면서 엽록소 함량도 낮아지는 것을 알 수 있었다. 그러나 주요 참나무류 수종의 피음 효과에 대한 생장반응은 지속적으로 관찰해야 하며, 엽록소 함량과 생장에 밀접한 관련이 있는 생리적 특성에 대한 연구도 필요할 것으로 생각된다.