• 제목/요약/키워드: intensity of light

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광도(光度)가 내음성(耐陰性)이 서로 다른 3수종(樹種)의 광합성(光合成) 생리(生理)에 미치는 영향(影響) (Effects of Light Intensity on Photosynthetic Activity of Shade Tolerant and Intolerant Tree Species)

  • 김판기;이용섭;정동준;우수영;성주한;이은주
    • 한국산림과학회지
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    • 제90권4호
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    • pp.476-487
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    • 2001
  • 본 연구는 내음수(耐陰樹)가 임상(林床)의 낮은 광도조건에 적응하는 기작을 구명하기 위해서, 양수(陽樹)와 내음수(耐陰樹)의 생육 광도 저하에 대한 광합성계(光合成系)의 적응반응을 서로 비교하였다. 이태리포플러, 음나무, 졸참나무 1년생 묘목을 대상으로 PPFD $920{\mu}mol\;m^{-2}s^{-1}$과 PPFD $80{\mu}mol\;m^{-2}s^{-1}$의 광도조건에서 5개월간 생장한 개체의 엽록소함량, 잎의 분광특성, 광합성특성 등을 조사하였다. 그 결과 양수인 이태리포플러는 생육 광도의 저하로 엽면적, 단위 엽면적 당의 엽록소함량, 빛의 흡수율 및 광합성에 대한 이용효율 등이 감소하고, 광합성의 광화학계 및 탄소고정계의 활성 저하로 낮은 광합성능력을 나타냈다. 그러나 내음성이 이태리포플러보다 강한 음나무와 졸참나무는 엽면적, 엽록소함량, 순양자수율을 증가시켜 빛의 흡수량과 광합성에 대한 이용효율을 높이는 적응반응을 나타냈다. 그리고 이들 수종은 낮은 광도에서도 광합성의 광화학계 및 탄소고정계의 활성이 정상적으로 유지되고 있음을 알 수 있었다.

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실내식물 개발을 위한 광조건이 자생 후추등의 생육과 광합성에 미치는 영향 (Effects of Light Intensity on the Growth Characteristics and Net Photosynthesis of Piper kadzura Native to Korea for Indoor Plants)

  • 방광자;주진희
    • 한국조경학회지
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    • 제32권4호
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    • pp.1-6
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    • 2004
  • This study was carried out to investigate the effects of light intensities on the growth and net photosynthesis of Piper kauzura under different shading levels : 0%, 50%, 70% and 90% of sunlight. Mortality rate was lowest under a 70% shading level but 0% and 90% shading levels were about 46% and 53% each respectively. Plant height was shorter and leaf size was smaller and yellowish under a 0% shading level but increased when light intensity was decreased. However, under a 90% shading level, growth of Piper kauzura was inferior to other treatments. Top fresh weight was about 11.24g under a 50% shading level and about two times higher than that observed in about 6.6g under a 90% shading level. Root fresh weight was about 7.7g under a 0% shading level and was about two times higher than that showed in about 3.84g and 3.64g under 90% and 70% respectively. Total chlorophyll content and chlorophyll a/b rate were increased when light intensity was decreased. Net Photosynthesis achieved the highest under a 70% shading level and maximum photosynthetic photon flux density was 150 molㆍm/sup -2/ㆍs/sup -1/. Therefore, growth of Piper kauzura was good under 50∼70% shading, Meaning that it is an indoor plant that could be highly utilized.

강도다리(Platichthys stellatus) 흑화발현에 미치는 조도의 영향 (Influence of Light Intensity on the Blind-side Hypermelanosis in Starry Flounder Plathchthys stellatus)

  • 김원진;신윤경
    • 수산해양교육연구
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    • 제28권4호
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    • pp.1098-1106
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    • 2016
  • To study the influence of light intensity on blind-side hypermelanosis of starry flounder, Platichthys stellatus, we compared growth, glucose, cortisol, ratio of malpigmented blind-side area, ambicolored fish ratio and expression of mch mRNA for 60 days in 0 lux(darkness) and 20 lux(low light density). The test was done in duplicate at 50 fish/tank with the selected ordinary juvenile flounder. The rearing was performed in FRP aquarium tanks ($H100cm{\times}L100cm{\times}W100cm$). Growth was higher in the 0 lux. The ratio of malpigmented blind-side area and ambicolored fish ratio were significantly higher at the 0 lux than at the 20 lux. The result suggests that 20 lux could inhibit the hypermelanosis. The expression level of MCH 1, 2 mRNA was significantly lower in 0 lux, indicating that MCH 1, 2 and light intensity are related to blind-side hypermelanosis of starry flounder.

Development of Light Transmission Fluctuation for Particle Measurement in Solid-Gas Two Phase Flows

  • YANG, Bin;WANG, Zhan-ping;HE, Yuan;CAI, Xiao-Shu
    • 한국입자에어로졸학회지
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    • 제12권1호
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    • pp.21-26
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    • 2016
  • In order to realize In-line and convenient measurement for solid-gas two phase flows, Light Transmission Fluctuation (LTF) based on the random variation of transmitted light intensity, light scattering theory and cross-correlation method was presented for online measurement of particle size, concentration and velocity. The statistical relationship among transmitted light intensity, particle size and particle number in measurement zone was described by Beer-Lambert Law. Accordingly, the particle size and concentration were determined from the fluctuation signal of transmitted light intensity. Simultaneously, the particle velocity was calculated by cross-correlation analysis of two neighboring light beams. By considering the influence of concentration variation in industrial applications, the improved algorithm based on spectral analysis of transmitted light intensity was proposed to improve measurement accuracy and stability. Therefore, the online measurement system based on LTF was developed and applied to measure pulverized coal in power station and raw material in cement plant. The particle size, concentration and velocity of powder were monitored in real-time. It can provide important references for optimal control, energy saving and emission reduction of energy-intensive industries.

해양미세조류 Dunaliella Salina 최적 배양을 위한 연구: LED 조명, 온도, 광도 및 공기주입 속도에 따른 효과를 중심으로 (Optimum Cultivation Condition of Dunaliella Salina: Effects of Light Emitting Diode as a Lighting Source, Temperature, Light Intensity and Air Flow Rates)

  • 최보람;김동수;이태윤
    • 대한환경공학회지
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    • 제34권9호
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    • pp.630-636
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    • 2012
  • 본 연구는 해양미세조류 Dunaliella salina을 LED 광원을 이용하여 배양한 연구로 배양에 필요한 최적의 파장, 광도, 공기공급속도 및 배양온도를 찾기 위하여 수행되었다. 낮은 배양온도에서보다는 높은 온도에서 성장이 빨랐으나, 본 실험에서는 $22^{\circ}C$에서 가장 잘 성장하는 것으로 확인되었다. LED 파장에 따른 성장실험에서는 백색 LED가 배양에 가장 효과적이었으며, 광도에 따른 실험에서는 실험 시 고려한 3가지 광도 중(3,000, 6,300, 8,000 Lux) 3,000 Lux에서 최대 세포농도인 1.30 g/L를 나타내었다. 공기공급속도의 증가는 Dunaliella salina의 성장속도와 반비례의 관계를 나타내었는데, 공기를 공급하지 않은 경우의 비증식속도 $1.12day^{-1}$와 비교하면 공기공급은 본 미세조류의 성장에 저해요인으로 작용함을 알 수 있었다.

Evaluation of light-emitting diode colors and intensities on slaughter performance, meat quality and serum antioxidant capacity in caged broilers

  • Zichao Tan;Chuanfeng Zhou;Xueping Shi;Lihua Wang;Shubai Wang
    • 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.

가변 광도에 따른 복합레진의 기계적 물성 및 변연누출도 변화 (MECHANICAL PROPERTIES AND MICROLEAKAGE OF COMPOSITE RESIN MATERIALS CURED BY VARIABLE LIGHT INTENSITIES)

  • 한승렬;민경산;신동훈
    • Restorative Dentistry and Endodontics
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    • 제28권2호
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    • pp.134-145
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    • 2003
  • Mechanical properties and microleakage of two composites [conventional hybrid type DenFil (VERICOM Co., Anyang, Korea) / micro matrix hybrid type Esthet X (Dentsply Caulk, Milford, DE, U.S.A.)] were evaluated to assess whether variable light intensity curing is better than conventional curing technique. Curing was done for 40 seconds in two ways of 2 step soft-start technique and 5 step ramping technique. Three kinds of light intensities of 50, 100, $200{\;}mW/\textrm{cm}^2$ were initially used for 10, 20, 30 seconds each and the maximum intensity of $600 {\;}mW/\textrm{cm}^2$ was used for the rest of curing time in a soft-start curing tech nique. In a ramping technique, curing was done with the same initial intensities and the light intensity was increased 5 times with the same rate to the maximum intensity of $600{\;}mW/\textrm{cm}^2$. After determining conditions that showed no different mechanical properties with conventional technique, Esthet X composite was filled in a class V cavity, which dimension was $4{\times}3{\times}1.5{\;}mm$ and cured under those conditions. Microleakage was evaluated in two ways of dye penetration and maximum gap estimation through SEM observation. ANOVA and Spearman's rho test were used to confirm any statistical significance among groups. The results were as follows : 1 Several curing conditions of variable light intensities resulted in the similar mechanical properties with a conventional continuous curing technique, except conditions that start curing with an initial light intensity of $50{\;}mW/\textrm{cm}^2$. 2. Conventional and ramping techniques were better than soft-start technique in mechanical properties of microhardness and compressive strength. 3. Soft-start group that started curing with an initial light intensity of $100{\;}mW/\textrm{cm}^2$ for 10 seconds showed the least dye penetration. Soft-start group that started curing with an initial light intensity of $200{\;}mW/\textrm{cm}^2$ for 10 seconds showed the smallest marginal gap, if there was no difference among groups. 4. Soft-start technique resulted in better dye-proof margin than conventional technique(p=0.014) and ramping technique(p = 0.002). 5. There was a very low relationship(p=0.157) between the methods of dye penetration and marginal gap determination through SEM evaluation. From the results of this study, it was revealed that ramping technique would be better than conventional technique in mechanical properties, however, soft-start technique might be better than conventional one in microleakage. It was concluded that much endeavor should be made to find out the curing conditions, which have advantages of both aspects or to solve these kinds of problems through a novel idea of polymerization.

Effect of Light Intensity on the Polymerization Rate of Composite Resin Using Real-time Measurement of Volumetric Change

  • La, Sung-Ho;Lee, In-Bog;Cho, Byeong-Hoon;Son, Ho-Hyun
    • 대한치과보존학회:학술대회논문집
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    • 대한치과보존학회 2001년도 추계학술대회(제116회) 및 13회 Workshop 제3회 한ㆍ일 치과보존학회 공동학술대회 초록집
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    • pp.589.1-589
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    • 2001
  • The aim of this study is to evaluate the effect of light intensity variation on the polymerization rate of composite resin using IB system(experimental equipment designed by Dr. IB Lee) by which real-time volumetric change of composite can be measured. Methods: Three commercial composites [Z100(Z1), AeliteFil(AF), SureFil(SF)] were photopolymerized with Variable Intensity Polymerizer unit (Bisco, U.S.A.) under the variable light intensity (75/150/225/300/375/450㎽$^2$) during 20sec.(omitted)

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A Study on the Optimized Test Condition of Lock-in IR Thermography by Image Processing

  • Cho, Yong-Jin
    • 비파괴검사학회지
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    • 제32권3호
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    • pp.276-283
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    • 2012
  • In this study, it was studies the utilization of LIT(lock-in infrared thermography) which can detect defects in welded parts of ship and offshore structures. Quantitative analysis was used through methods of filtering and texture measurement of image processing techniques to find the optimized experimental condition. We verified reliability in our methods by applying image processing techniques in order to normalize evaluations of comparative images that show phase difference. In addition, low to mid exposure showed good results whereas high exposure did not provide significant results in regards to intensity of light exposure on surface. Lock-in frequency was satisfactory around 0.1 Hz regardless of intensity of light source we had. In addition, having the integration time of thermography camera inversely proportional to intensity of exposed light source during the experiment allowed good outcome of results.

비음처리에 따른 붓순나무의 광합성, 엽록소 함량 및 엽 특성 (Photosynthesis, Chlorophyll Contents and Leaf Characteristics of Illicium anisatum under Different Shading Treatments)

  • 손석규;한진규;김찬수;황석인;정진현;이성기
    • 한국환경과학회지
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    • 제16권11호
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    • pp.1313-1318
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    • 2007
  • Illicium anisatum was bred under four different light intensity. Those condition were full sunlight(PPFD $1600{\mu} mol\;m^{-2}s^{-1}$), 30% treatment(PPFD $400{\mu} mol\;m^{-2}s^{-1}$), 50% treatment(PPFD $250{\mu} mol\;m^{-2}s^{-1}$) and 70% treatment(PPFD $100{\mu} mol\;m^{-2}s^{-1}$), respectively. Chlorophyll a and b were increased according to decrease of light intensity. Thirty percent and 50% treatment had not significant different in chlorophyll a and b. Thirty percent treatment was shown the best photosynthetic activity through invested photosynthetic rate, intercellular $CO_2$ concentration and water use efficiency. Photosynthetic activity trend of 50% treatment was similar to 30% treatment. Seventy percent treatment was shown the best photosynthetic activity at low light intensity but that was decreased to lower value than 30% and 50% treatment under high intensity. Control, bred full sunlight, was shown the worst photosynthetic activity at measured all light intensity. That result could imply that was caused by photo-inhibition because of long term exposed of shade tolerant plant at high light intensity. Leaf characteristics had not significant different in leaf length, width and area but leaf dry weight had similar trend to photosynthetic activity.