• Title/Summary/Keyword: light effect

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Effect of photoperiod and light intensity on in vitro propagation of Alocasia amazonica

  • Jo, Eun-A.;Tewari, Rajesh Kumar;Hahn, Eun-Joo;Paek, Kee-Yoeup
    • Plant Biotechnology Reports
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    • v.2 no.3
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    • pp.207-212
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    • 2008
  • Plantlets of Alocasia amazonica regenerated under a photon flux density (PFD) of 15 or $30{\mu}mol\;m^{-2}s^{-1}$ showed better growth and development than those grown under higher PFDs. While chlorophyll a and chlorophyll b decreased, the number of stomata increased with increasing PFD. Photoperiods also affected plantlet growth and stomatal development. Highest growth was observed for the short photoperiod (8/16 h) and for equinoctial (12/12 h) light and dark periods. Very few stomata developed in the leaves of plantlets grown under a short photoperiod (8/16 h) and the number of stomata increased with increasing light period. In conclusion, both light intensity and photoperiod independently affect growth of A. amazonica and development of stomata, depending on the intensity and duration of light treatment.

The Study of domestic application for the Guideline of Model Outdoor Lighting Ordinance (MLO 옥외조명 설치지침의 국내 적용성 연구)

  • Jung, Jong-Hwan;Lee, Kyumok;Gu, Jinhoi
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.11
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    • pp.20-29
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    • 2012
  • The outdoor lighting is provided for a variety of purposes, for work or recreation, for safety or security, for amenity and for advertising or display. But the effects of lighting on the natural environment can be difficult to quantify. At present, in many countries, various policies to manage the light trespass from outdoor light have been planned. For example, Model Lighting Ordinance(MLO) will allow communities to drastically reduce light pollution and glare and lower excessive light levels. The recommended practices of the IES can be met using readily available, reasonably priced lighting equipment. So, it this paper, we analyze the effect of road lighting on light trespass using by RELUX program. And then we consider the possibility of practical application of BUG rating in Korea.

Effect of Culture Conditions on Production of Polysaccharides and Growth Rate of Porphyridium cruentum (Porphyridium cruentum의 성장 및 당질 생산에 미치는 배양 조건의 영향)

  • Joo, Dong-Sik;Choi, Soon-Yeong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.41 no.6
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    • pp.446-451
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    • 2008
  • The growth of Porphyridium cruentum and its porphyran polysaccharide production were measured as functions of light intensity, temperature, light quality (fluorescent, blue, red, and green) and nitrate concentration. The optimum light intensity, temperature, and nitrate concentration for the growth of Porphyridium cruentum and for its polysaccharide production were 1,400 lx, $25^{\circ}C$, and 0.03%, respectively. The maximum cell concentration and polysaccharide content under the optimum conditions were 1.95 and 0.23 mg/mL, respectively. Light quality did not influence growth or polysaccharide production. The best results for growth and polysaccharide production were obtained using fluorescent light.

Light-susceptibility of Camptothecin Production from in Vitro Cultures of Camptotheca acuminata Decne

  • Park, Young-Goo;Park, Mee-Hee;Yang, Jae-Kyung;Chung, Young-Gwan;Park, Myung-Suk
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.8 no.1
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    • pp.32-36
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    • 2003
  • Production of camptothecin ((PT) from callus cultures of Camptotheca acuminata Decne was affected by light and culture conditions. Among the culture media tested, modified B5 medium containing 3% (w/v) sucrose, 2 mg/L B,4-D, 2 times of MS medium vitamins, 500 mg/L casein hydrolysate, 250 mg/L myo-inositol, 0.05% (w/v) activated charcoal, and 0.15% (w/v) gelite was used for callus induction . The highest cell growth and CPT production were obtained in dark and green light condition, respectively. Photoperiod has no effect on cell growth and CPT production. Both cell growth and CPT production were also influenced by combination ratio of red and blue light .Cell growth and CPT production were the highest in the ratio of red and blue light,90:10.

A BIOMECHANICAL STUDY ON THE EFFECT OF LIGHT WIRE TORQUING AUXILIARY (Light wire torquing auxiliary의 효용도에 관한 생력학적 연구)

  • Park, Kyung Jin
    • The korean journal of orthodontics
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    • v.2 no.1
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    • pp.29-34
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    • 1971
  • 저자는 교정환자 치료에 흔히 사용되는 Light wire torquing auxiliary의 반경의 크기 및 교합면에 대한 spur 각도의 증감에 따라 Light wire torquing auxiliary 애서 발생되는 힘이 어떻게 변화하는 가를 Dentiform typodont 위에서 측정 관찰하여 아래와 같은 결과를 얻었다. 1) Light wire torquing auxiliary circle의 반경의 크기가 감소할 수록 발생되는 힘의 크기는 증가하였으나, 반경의 크기에 반비례하지는 않았다. 즉, Light wire torquing auxiliary circle의 반경을 20 mm.에서 10mm.로 하였을때 발생되는 force는 2배로 나타나지는 않았다. 2) 교합 평면에 대한 spur의 각도가 감소할 수록 force는 증가하였다. 이때 교합 평면에 대한 spur의 각도를 감소시킨 상태에서 교합 평면과 치아가 이루는 각도를 증가시켜 줌으로써 항속적인 힘의 증가를 나타냈다.

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The Study on Structures and Contents for Flight Information Service of Light Aircraft and Ultra-light Aircraft (경량항공기 및 초경량비행장치 비행정보서비스를 위한 구성체계 연구)

  • Choi, Hyunsik;Moon, Woochoon
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.22 no.3
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    • pp.1-7
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    • 2014
  • The base of leisure air activities are consistently expanding and its demand is expected to increase attributed to GDP growth and people's interest in its activity. Utilizing Visual Flight Rule, light sport aircrafts and ultra-light aircrafts are not under the effect of air traffic control center, which resulted in passenger injury due to emergency landing for adverse weather conditions and technical issues after pulling into mountain area, ocean and even urban area. Such events encouraged safety consciousness toward leisure aircraft activities and developing a measure to prevent a recurrence of the accident. This research focuses on suggesting compositive system for preventive safety management system by providing user based Flight information service and operating effective system, necessary for leisure aircraft activities.

Fabrication of MILC poly-Si TFT using scanning-RTA and light absorption layer

  • Pyo, Yu-Jin;Kim, Min-Sun;Kim, Young-Soo;Song, Nam-Kyu;Joo, Seung-Ki
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.307-309
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    • 2005
  • We investigated light absorption layer effect on metal-induced lateral crystallization (MILC) growth rate and MILC thin films transistors (TFTs). As annealing method, we used scanning-rapid thermal annealing (RTA). MILC growth rate which was crystallized by light absorption layer and using scanning-RTA was 3 times than normal MILC which was without light absorption layer growth rate. Also we compared MILC TFTs characteristics which were combined to light absorption layer with conventional MILC TFTs. After scanning-RTA process, MILC-TFTs which were with light absorption layer were superior to conventional MILC-TFTs. With this new MILC-TFTs structure, we could reduced crystallization time and obtain good electrical properties.

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Modern Coherence Theory of Light (빛의 간섭성 이론)

  • 김기식;이종민
    • Korean Journal of Optics and Photonics
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    • v.2 no.1
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    • pp.36-49
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    • 1991
  • The coherence properties of electromagnetic fields are reviewed, based on both the classical and quantum theories. The elementary concepts, employed frequently in the discussion of interference phenomena, are summarized. The well-known interference phenomena are described in terms of second-order coherences. The coherence theory in space-frequency domain is introduced and the coherent mode representation is presented. The generation and propagation of coherence of light are analysed and it is shown that the coherence of light is developed as light propagates. The quantum theory goes parallel with the classical theory, via the optical equivalence theorem. There are, however, certain nonclassical characteristics of light, which may not be easily understood in classical therms. These nonclassical phenomena are believed to originate from the particle aspects of light. The quantum effect on the interfernce phenomena is analysed and finally the outlook of the future research is briefly mentioned.

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Studies on the Optimum Light Intensity for Growth of Panu ginseng (II) Study on the difference of the optimum light intensity for the growth of ginseng Plant accordingto the root age (인삼생육의 최적광량에 관한 연구 (제2보) 인삼생육에 대한 최적광량의 년생간 차이에 관하여)

  • 이종철;천성기
    • Journal of Ginseng Research
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    • v.6 no.2
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    • pp.149-153
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    • 1982
  • To investigate the effect of light intensity on the growth of shoots and roots, water and chlorophyll contents in the ginseng leaf were determined at 5%, l0%, 20%, 30% light transmittance rate (LTR) with 1,2 and 4 year-old ginseng plants in the field. Stem length, size of the leaf, water and chlorophyll contents were decreased as the increase of the light intensity in all ages of ginseng plants. The degree of decrease was severe in the one year-old ginseng compared to that of 2, or 4 year-old ginseng, while there was no difference between the 2 and 4 year-old plants. Root weight per plant was highest at 5% LTR in the one year-old plants, while it was at 20% LTR in the 2 and 4 year-old plants. Generally, demand of light for the growth of one year-old ginseng was lower than those of 2 or 4 year-old plants there was no difference of it among the ginseng plants older than 2 years.

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Photocatalyst Effect of Polyester Fabrics Treated with Visible-light Responsive Photocatalyst

  • Choi, Sei Young
    • Elastomers and Composites
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    • v.51 no.1
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    • pp.31-37
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    • 2016
  • In this study, we studied the photocatalytic functionality such as deodorant, antibacterial, antistatic of polyester fabrics treated with visible-light responsive photocatalyst. According to UV/visible spectrometry result, the UV-visible peak of visible-light responsive photocatalyst was found to be red shift at 420 nm sensitive in the visible light region. Also, the deodorizing and antimicrobial performance were shown to be retained more than 99% both before washing and even after 25 times washing. According to washing durability of polyester fabrics treated with visible-light responsive photocatalyst, the reduction effects for gas such as ammonia, trimethylamine, formaldehyde and toluene after 25 times washing appeared to be retained as much as before washing. At both before washing and after 25 times washing, antistatic property showed frictional voltage of approximately 250V.