• Title/Summary/Keyword: 광억제

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Effect of Light Quality on Growth of Cucumber Plug Seedlings (광질이 오이 플러그 묘의 생육에 미치는 영향)

  • 용영록;황세진;김일섭
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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    • 2000.10b
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    • pp.89-93
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    • 2000
  • 광파장 및 조사시기에 따른 오이묘의 생육 반응을 검토하였다. 광원에 따른 오이 묘의 생육상태를 조사해본 결과 청색광, 적색광을 처리한 것이 생체중, 하배축 무게, 근중이 증가하면서 하배축의 신장이 억제되었고, 청색광과 적색광을 혼합하여 야간 12시간씩 조사하여 30일간 육묘해 본 결과 뿌리의 발육도 우수하고, 줄기와 잎의 생육 정도에서도 우량묘의 소질을 보였다. 청색광과 적색광을 혼합하여 야간 6시간과 12시간씩을 조사하여 30일간 육묘한 결과 하배축의 길이는 각각 60.0mm와 44.9mm였고, 하배축의 무게는 0.59g, 0.62g으로 나타나 12시간 조사구가 하배축의 신장억제효과가 큰 것으로 나타났다. 하배축의 엽록소 함량은 청색광과 적색광의 조사시간이 길어질수록 뚜렷이 증가하였고, 식물체도 진한 녹색을 나타냈다. 광처리구와 무처리구의 오이묘 하배축의 횡단면과 종단면을 검경하여 세포구조를 비교해 본 결과 광처리구의 횡단면 표피조직은 단층의 밀착된 세포로 되어 있으며, 바깥쪽 세포는 현저하게 두꺼웠다. 후각조직의 세포는 작고 부정형이며, 세포간극이 조밀하였으며, 세포구조도 치밀한 특성을 보였다. 종단면은 광처리구에서 세포가 짧고 세포간에 간극이 없는 반면 무처리구는 세포가 길고 뚜렷이 구분되지 않은 것이 관찰되어 대체로 광처리구는 무처리구에 비해 세포신장이 억제되는 대신 세포구조가 치밀하여 식물체의 도장이 억제된다는 것을 알 수 있었다.

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Control of the Photo-induced Discoloration of the Handmade Korean Paper with Polyethylene Glycol (Polyethylene Glycol에 의한 수록한지(手漉韓紙)의 광(光) 변색(變色) 억제(抑制))

  • Cheon, Cheol;Park, Soo-Ahn
    • Journal of Korean Society of Forest Science
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    • v.89 no.2
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    • pp.161-166
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    • 2000
  • Classified handmade Korean paper which has been commonly used as the material for the paper cultural assets divide into four classes. We irradiated xenon arc lamp, which has almost the same spectrum distribution as natural sunlight, to test photo-induced of discoloration according to PEG molecular weight and concentration. So, we reach the followings. 1) Unbleached handmade Korean paper with PEG showed rapid decrease of brightness for 10 hours after photo-irradiation, regardless of molecular weight of PEG, but, after 10 hours, it showed gradual increase of brightness. From this, it proved that there was an effect of preventing discoloration of photo-irradiation. 2) Chemical bleached handmade Korean paper showed increase of brightness after 20 hours. Though time was delayed in increase of brightness, there was also an effect of preventing discoloration of photo-irradiation in chemical bleached paper. 3) Handmade Korean paper made with abet-mosk showed the lowest of brightness when it was tested on 400-20% PEG. Before photo-irradiation, the brightness of paper, applied it, was the lowest, but it showed the least difference of brightness after photo-irradiation. From this, it proved that there was the greatest effect of preventing discoloration in this paper. 4) Preventing yellowish, the first phenomena by photo-irradiation ageing with applying PEG was proved that there was the decrease of value of $b^*$ +, and increase value of $L^*$, which could fairly prevent decrease of brightness.

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In vitro Screening of Natural Product Inhibitors on the UVB Phototoxicity (In vitro 실험법에 의한 천연물 중의 UVB 광독성 억제제 검색)

  • 김현진;이경아;김봉희
    • Journal of Food Hygiene and Safety
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    • v.17 no.4
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    • pp.188-192
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    • 2002
  • The phototoxicity inhibitory activity of 15 natural products having antiinflammatory effect was screened by three in vitro methods : yeast growth inhibition test with Candida albicans, RBC photohemolysis and MTT assay. We induced phototoxic reaction by irradiating UVB (312 nm) on chlorpromazine (CPZ) that has been widely documented as phototoxic agent in clinical and experimental studies and then observed the effects of the natural products after treating them with CPZ. In yeast growth Inhibition test, P. persica and E. officinalis showed the inhibitory effect on the UVB phototoxicity and E. officinalis, yeast, P. suffruticosa showed phototoxicity inhibitory effect in that their % hemolysis compared with control were 45.76 $\pm$ 0.91, 34.42$\pm$1.01, 35.30 $\pm$4.76 on UVB. In MTT assay, all tested natural products increased cell viability compared with the contort.

Transmission of 200-Gb/s 2-channel OTDM-PAM4 Signal Based on CSRZ Pulse Generated by Mach-Zehnder Modulator (마하 젠더 변조기로 생성된 CSRZ 펄스 기반의 200 Gb/s OTDM-PAM4 신호의 전송)

  • Sunghyun Bae
    • Korean Journal of Optics and Photonics
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    • v.34 no.4
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    • pp.151-156
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    • 2023
  • We propose to implement cost-effectively a high-speed short-haul interconnect by transmitting a 200-Gb/s/λ two-channel optical time-division-multiplexed signal generated by a carrier-suppressed optical pulse, which improves the robustness of the multiplexed signal to chromatic dispersion. The multiplexed 200-Gb/s signal is generated in the transmitter by combining two 100-Gb/s 4-level pulse-amplitude-modulated signals (generated using the optical pulse and two Mach-Zehnder modulators). After the signal is transmitted over a fiber, it is amplified by a semiconductor optical amplifier and detected by a photodiode. The amplified spontaneous emission noise is eliminated by an optical band-pass filter. The transmitted signal is reconstructed by a 2 × 2 multiple-input multiple-output equalizer, which compensates for crosstalk. Due to the use of the carrier-suppressed optical pulse, the 200-Gb/s signal can be transmitted over fiber with a chromatic dispersion of 40 ps/nm.

광통신 케이블 설계에 관한 연구

  • 송관호;마영찬;이원승
    • Proceedings of the Korean Institute of Communication Sciences Conference
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    • 1982.10a
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    • pp.29-32
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    • 1982
  • 본 논문은 광섬유 케이블의 설계에 있어, 케이블 공정에 따른 광손실의 증가를 최소로하는 케이블의 구조 및 광케이블의 포설에 따른 잔류 응력의 억제 등, 장기간 동안 케이블의 전송특성을 유지하며, 광섬유의 파단 방지를 목표로 고려해야할 사항을 논하였다. 광섬유의 특성을 유지하기 위해서는 광섬유 제조시 사용되는 재질 및 적정 Dimension 설정이 필요하며 광섬유 파단 방지를 위해 CABLE내에 TENSION MEMBER를 수용하는 구조를 검토, 광섬유 CABLE 포설시 광섬유의 파단 확률을 감소시키며, 광섬유의 잔류응력을 억제하는 관점에서 케이블 구조를 설계하였다.

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Effects of different shading levels in summer on the growth and flowering of Doritaenopsis hybrida (하절기 차광 정도가 Doritaenopsis의 생육과 개화에 미치는 영향)

  • 이동수;박삼기;이용범;유기문
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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    • 2003.04a
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    • pp.123-127
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    • 2003
  • 호접란 생산에 있어서 광환경은 제어하기 어려운 환경요인중 하나이다. 현재 호접란을 생산하는 농가에서는 고정형태의 차광 시설을 이용하여 과도한 차광환경 아래에서 생산하는 경향이 두드러진다. 이러한 과도한 광 차단은 호접란의 생육을 억제 할 수 있으며 그 결과 생산시기가 길어짐에 따라 노동력과 생산비의 상승을 가져온다. 호접란에 있어 광환경이 개화에 미치는 영향은 매우 크며, 개화촉진이나 억제에 영향을 미치는 것으로 알려져 있다. (중략)

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Development of Light-Treatment Technology for Producing Tomato Transplants of High Quality -Effects of End-of-day Light Treatment Affecting on the Quality of Tomato Transplants- (고품질의 토마토묘 생산을 위한 광처리 기술개발 -일몰 후 광처리가 토마토묘 소질에 미치는 영향-)

  • 이귀현
    • Journal of Bio-Environment Control
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    • v.10 no.1
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    • pp.55-60
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    • 2001
  • To investigate the effect of red light (R) and far-red light(FR) on controlling the growth of tomato transplants, height, length of 1st internode, and stem diameter of plant were measured every 12 days during 24 days of light treatment. At the end of experiment, fresh and dry weights of roots and shoots were measured. Generally, it was shown that the height of plant was suppressed by the treatment of FR. However, the effect of light-treatment time (10 or 20 min) on plant height was not significant. Stem diameter of the plant treated with R was greater than that of the plant treated with FR or the control. Dry weight ratio of shoot to root of the plant treated with R was smaller that of the plant treated with FR. R was more effective than the control, which was more effective than FR, in making the transplant compact.

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Effects of Light on Activities of Antioxidative Enzymes in Hairy Root Cultures of phytolacca esculenta Houtte (자리공(Phytolacca esculenta van Houtte) 모상근배양에서 항산화효소의 활성에 미치는 광의 영향)

  • 양덕조;김용해;권진이;최철희;양덕춘
    • Korean Journal of Plant Tissue Culture
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    • v.22 no.2
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    • pp.71-76
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    • 1995
  • The effects of light on the activities of several antioxidative enzymes, catalase (CAT), superoxide dismutase(SOD), ascorbate oxidase(AO), and peroxidase(POD) were examined in the hairy root cultures of Phytolacca esculenta van Houtte induced by Agrobacterium tumefaciens $A_4$T. Activities of CAT, SOD, and AO were significantly decreased with incresing light intensity (500-2,000 lx). The activity of AO under high light condition (2,000 lx)was decreased by 92% compared to the dark condition. The activities of glutathoine peroxidase (GPO), ascorbate peroxidase (APO) and general POD were increased under lower light intensify below 500 lx. The activity of GPO under 2,000 lx was decreased by 85% compared to the dark condition. The activities of antioxidative enzymes were more decreased in blue light (400-500nm). The activities of antioxidative enzymes in blue light intensity were increased in lower light intensity below 30 lx, but decreased 21-70% under 200 lx. The activity of AO was decreased by 70% under 200 lx with increasing blue light intensity. Our results suggest that the activities of antioxidative enzymes in hairy roots might be inhibited by endogenous oxidants generated under the high blue light conditions.

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Photo-aging regulation effects of newly bred Green ball apple (신품종 그린볼 사과의 광노화인자 조절효과)

  • Lee, Eun-Ho;Lee, Seung-Yeol;Jung, Hee-Young;Kang, In-Kyu;Ahn, Dong-Hyun;Cho, Young-Je
    • Journal of Applied Biological Chemistry
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    • v.63 no.1
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    • pp.75-82
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    • 2020
  • In this study, extracts from the Green ball apple peel (GBE) and the newly bred green ball apple from Korea showed inhibition effects on photo-aging factor regulation associated with skin aging. To investigate the inhibition effect on photo-aging factor regulation in skin, GBE was treated with UVB to induce photo-aging related factors in CCD986sk fibroblast cells. Photo-aging factor regulation effects showed that GBE inhibited UVB-stimulated matrix metalloproteinase (MMP)-1 and MMP-9 protein synthesis in collagen type I alpha 2 chain (COL1A2), MMP-1, MMP-9, and tissue inhibitors of metalloproteinase (TIMP)-1 protein expression. The expression of COL1A2 and TIMP-1 protein was significantly increased. The mRNA expression levels of COL1A2, MMP-1, MMP-9, hyaluronan synthase (HAS)2, transforming growth factor (TGF)-β, and TIMP-1 were decreased by GBE. The expression of TIMP-1 and TGF-β, which are regulators involved in matrix metalloproteinase and type I procollagen expression, was found to increase with increasing expression of COL1A2. The expression of HAS2, which is involved in the production of hyaluronic acid, one of the structural proteins constituting the skin, was also confirmed. Therefore, GBE showed excellent efficacy against photo-aging factor regulation and could be used as functional material to prevent and treat skin aging.

Effect of Light and Long-day Interruption during Short-day Period on Heading of Rice Plant (단일기간중 암기중간의 광처리 및 장일에 의한 간섭이 수도 출수에 미치는 영향)

  • Mun-Hue Heu;Kwang-Ho Kim
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.21 no.2
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    • pp.211-217
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    • 1976
  • Experiments were conducted to test the effect of light and long-day interruption on the elimination of short-day effect. The effects of both the short-day treatments and the light interruption treatments were cumulative.

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