• 제목/요약/키워드: Light response

검색결과 1,441건 처리시간 0.036초

광반응 변위전류의 체인길이에 따른 영향 (The Effect According to Chain Length of Light Response Displacement Current)

  • 김성진;강용철;정헌상;구할본;최영일;백순기;이경섭
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 하계학술대회 논문집
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    • pp.495-498
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    • 2000
  • In this paper, generation form of displacement current was compared and measured with air-water interfacing induce monolayers which 8A5H with azobenzene and arac.acid mixed. Light response of two monolayers which chain length are different was compared and measured though they are the same isomer. The experimental results are as following; In the displacement current form of mixed monolayers and 8A5H, mixed monolayers which chain length is longer than that of 8A5H caused the displacement current about 40[fA] mole. This is the reason chain length of hydrophobicity in mixed monolayers is longer than that of 8A5H In the case of light stimulus mixed monolayers reacted less than 8A5H about 9[fA]. This is the reason molecule dynamic behaviour in cia and trans was net activated due to its very long chain length.

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가시광 무선인식장치에서 비트간 잡음검출에 의한 잡음광의 영향 감소 (Reducing the Effects of Noise Light Using Inter-Bit Noise Detection in a Visible Light Identification System)

  • 황다현;이성호
    • 센서학회지
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    • 제20권6호
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    • pp.412-419
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    • 2011
  • In this paper, we used the inter-bit noise detection method in order to reduce the effects of noise light in a visible light identification system that uses a visible LED as a carrier source. A visible light identification system consists of a reader and a transponder. When the enable signal from the reader is detected, the transponder encodes the response data in RZ(Return-to-Zero) bit stream and sends response signal by modulating a visible LED. The reader detects the response signal mixed with noise light, samples the noise voltage in each blank low time between data bits of the RZ signal, and recovers the original data by subtracting the sampled noise from the received signal. In experiments, we improved the signal-to-noise ratio by 20dB using the inter-bit noise detection method.

Arabidopsis phytochrome mutant에서 빛이 뿌리 생장과 굴중성 반응에 미치는 영향 (Effect of Light on Root Growth and Gravitropic Response of Phytochrome Mutants of Arabidopsis)

  • 박지혜;이상승;우순화;김순영
    • 생명과학회지
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    • 제22권5호
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    • pp.681-686
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    • 2012
  • 빛이 굴중성과 뿌리 생장에 미치는 영향을 알아보기 위해 Arabidopsis phytochrome mutant를 이용하여 뿌리 생장과 굴중성 반응을 측정하였다. $PhyA$의 뿌리 생장은 white light를 제외한 모든 빛 조건에서 WT와 비교하여 촉진되었다. 특히 red light에서 키웠을 때 다른 mutant와는 달리 뿌리 생장이 촉진되었다. 반면에 phyB는 모든 빛 조건에서 키웠을 때 뿌리 생장이 억제되었으며, 특히 double mutant인 $phyAB$는 white light와 red light에서 키웠을 때 뿌리 생장이 가장 많이 억제되었다. $PhyA$의 굴중성 반응은 far-red light에서 키웠을 때를 제외하고 모든 빛 조건에서 키웠을 때 WT와 비교하여 촉진되었다. 한편 $phyAB$는 모든 조건에서 모두 굴중성 반응이 억제되었다. Ethylene 생합성을 조절하는 효소인 ACS transcript 수준은 white light와 red light에서 키웠을 때 $phyA$가 높게 나타났으며, far-red light에서 키웠을 때는 $phyA$의 transcript 수준이 억제되었다. 결론적으로 뿌리 생장과 굴중성 반응은 $phyB$$P_{fr}$에 의해 조절된다.

Competition Responses of Populus alba Clone ‘Bolleana’ to red:far-red light

  • Bae, Han-hong;Kang, Ho-duck;Richard B. Hall
    • Plant Resources
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    • 제7권1호
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    • pp.77-86
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    • 2004
  • The reduced ratio of red:far-red (R:FR) light acts as a measure of the proximity of competitors and plants can detect the potentially competing neighbor plants by perceiving reflected R:FR signals and initiate the response of “shade avoidance” before actual shading occurs. The phytochrome system is responsible for monitoring the changes in the R:FR and initiating the shade avoidance response. The response to low R:FR ratio was studied in a white aspen Populus alba clone ‘Bolleana’ using two filter systems: a clear plastic filter system that allows a R:FR ratio less than 1.0 to pass from adjacent border plant reflection; and a special commercial plastic that blocks FR light and creates a R:FR ratio above 3.0. The reduced R:FR signals enhanced the stem elongation in response to competition at the expense of relative stem diameter growth. Trees grown inside clear chambers were 27 % taller than trees grown inside the FR-blocking filter chambers. Stem taper of clear chamber trees was 16% less than the FR-blocking filter trees. Low R:FR also induced 22% more stem dry weight and 13% greater petiole length per leaf compared to the FR-blocking filter trees. There were no statistically significant differences in leaf area, leaf number increment, and total dry weight between the two light filter treatments.

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LED Light Quality Protects Iron Deficiency and Improves Photosynthesis and Biomass Yield in Alfalfa (Medicago sativa L.)

  • Ki-Won Lee;Sang-Hoon Lee;Yowook Song;Yowook Song;Jae Hoon Woo;Bo Ram Choi;Md Atikur Rahman
    • 한국초지조사료학회지
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    • 제43권3호
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    • pp.177-182
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    • 2023
  • Iron (Fe) is a vital element for plants and other organisms, involving in several physiological processes including respiration, chlorophyll biosynthesis, and photosynthesis. Unfortunately, how Fe accumulation regulates in response to light quality has not been well established in plants. Therefore, the aim of the study was to explore the mechanism of Fe homeostasis by light quality. In this study, we found morpho-physiological attributes were significantly improved in response to blue (λmax: 450) compared to white (λmax: 500) and red (λmax: 660) light. The root-shoot length, plant biomass, photosynthesis efficiency (Fv/Fm) and leafgreen (SPAD) significantly declined in response to white and red light. However, these parameters were improved and iron deficiency was substantially alleviated by blue light exposure in alfalfa seedlings. This study might be useful to the forage breeders and farmers for improving alfalfa yield and nutritional benefits.

Preliminary study on the visual sensitivity of Oreochromis niloticus using LED light source for the aquaculture development in Uganda

  • Esther Kagoya;Kyoungmi Kang
    • Fisheries and Aquatic Sciences
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    • 제26권8호
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    • pp.514-523
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    • 2023
  • The visible threshold of Oreochromis niloticus responded to high light intensity under short wavelengths, whereas the response to low light intensity under long wavelengths was low, with a minimum visual threshold of 574 nm of LED lights. Movement distance of O. niloticus was dropped at 31℃ and increased abnormally at 37℃ under natural light. Comparing movement distance under red (622 nm) and green (518 nm) lights of LED, movement distance and swimming speed under red and green lights were higher than under natural light. However, the movement distance decreased rapidly at 31℃ under red light and lowest at 33℃ under green light. After that, there was a tendency to adapt to high water temperatures gradually. Consequently, red and green lights may be recommended for O. niloticus's aquaculture because the red and green lights have a positive effect on growth performance, survival rate, and metabolism, as shown in previous studies. It is necessary to control the water temperature below 32℃ because abnormal behavior above 32℃ revealed under red and green LED lights and natural light.

Mitogen-Activated Protein Kinase Kinase 3 Is Required for Regulation during Dark-Light Transition

  • Lee, Horim
    • Molecules and Cells
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    • 제38권7호
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    • pp.651-656
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    • 2015
  • Plant growth and development are coordinately orchestrated by environmental cues and phytohormones. Light acts as a key environmental factor for fundamental plant growth and physiology through photosensory phytochromes and underlying molecular mechanisms. Although phytochromes are known to possess serine/threonine protein kinase activities, whether they trigger a signal transduction pathway via an intracellular protein kinase network remains unknown. In analyses of mitogen-activated protein kinase kinase (MAPKK, also called MKK) mutants, the mkk3 mutant has shown both a hypersensitive response in plant hormone gibberellin (GA) and a less sensitive response in red light signaling. Surprisingly, light-induced MAPK activation in wild-type (WT) seedlings and constitutive MAPK phosphorylation in dark-grown mkk3 mutant seedlings have also been found, respectively. Therefore, this study suggests that MKK3 acts in negative regulation in darkness and in light-induced MAPK activation during dark-light transition.

화재 사고에 대비한 무인 경전철의 비상대응절차에 관한 연구 (A Study on the Emergency Response Procedure of Unmanned Light Rail Transit (LRT) against Fire Accident)

  • 김연규
    • 대한토목학회논문집
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    • 제32권2D호
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    • pp.183-187
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    • 2012
  • 본 논문은 최근 상업 운전을 시작한 무인 경전철의 안정적인 운영을 위한 열차 화재사고 비상대응절차를 마련하기 위한 것이다. 기존 비상대응절차와 관련하여 무인 경전철이 갖는 하드웨어적, 소프트웨어적 특성을 분석하고, 특히 무인이 갖는 중요한 의미를 반영한 절차서를 제시하였다. 비상대응절차는 우선 비상대응계획의 목적 등에 부합해야하는데 이를 위해서 다음의 절차를 제시하였다. 첫째, 비상대응을 지원하기 위한 기능별 비상대응체계 구축, 둘째, 비상대응직원 및 기관간의 신속한 대응조치를 위한 표준운영절차(SOP) 구축, 셋째 일상 상황에서 비상대응직원에 대한 비상대응훈련 등의 체계를 반영한 상세 항목이다. 아울러 향후 이러한 비상대응계획에 따라 효율적인 관리를 위해 직원을 대상으로 한 훈련프로그램이 제시되어야 한다.

Involvement of lncRNA-HOTTIP in the Repair of Ultraviolet Light-Induced DNA Damage in Spermatogenic Cells

  • Liang, Meng;Hu, Ke
    • Molecules and Cells
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    • 제42권11호
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    • pp.794-803
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    • 2019
  • Ultraviolet light (UV)-induced cellular response has been studied by numerous investigators for many years. Long noncoding RNAs (lncRNAs) are emerging as new regulators of diverse cellular process; however, little is known about the role of lncRNAs in the cellular response to UV treatment. Here, we demonstrate that levels of lncRNA-HOTTIP significantly increases after UV stimulation and regulates the UV-mediated cellular response to UV through the coordinate activation of its neighboring gene Hoxa13 in GC-1 cells (spermatogonia germ cell line). UV-induced, G2/M-phase arrest and early apoptosis can be regulated by lncRNA-HOTTIP and Hoxa13. Furthermore, lncRNA-HOTTIP can up-regulate ${\gamma}-H_2AX$ and p53 expression via Hoxa13 in UV-irradiated GC-1 cells. In addition, p53 has the ability to regulate the expression of both lncRNA-HOTTIP and Hoxa13 in vitro and in vivo. Our results provide new data regarding the role lncRNAs play in the UV response in spermatogenic cells.

아조벤젠 유기단분자의 광제어에 관한 연구 (A Study on the Light Control of Azobenzene Organic Monolayers)

  • 김성진;정헌상;이경섭
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 춘계학술대회 논문집 전자세라믹스 센서 및 박막재료 반도체재료 일렉트렛트 및 응용기술
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    • pp.139-142
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    • 2000
  • Displacement current was generated in the light stimulus. Solution of azobenzene molecules (8A5H) have to character trans-to-cis. The Maxwell displacement current measuring technique has been applied for the investigation of azobenzene organic thin films under alternating photoirradiation with ultraviolet($\lambda_1$) and visible($\lambda_2$) light. also, As laser beam(630~670nm) investigate light response. As result, ultraviolet($\lambda_1$) and visible($\lambda_2$) light see photoisomerization response, but laser beam not appear photoisomerization in current that differ wave range reagent.

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