• 제목/요약/키워드: Light conditions

검색결과 3,325건 처리시간 0.037초

광강도에 따른 음나무 유묘의 생장 및 광합성 특성 (Effects of Light Intensity on Photosynthesis and Growth in Seedling of Kalopanax pictus Nakai)

  • 이철호;신창호;김규식;최명석
    • 한국약용작물학회지
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    • 제14권4호
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    • pp.244-249
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    • 2006
  • 다양한 광환경에 대한 음나무 유묘의 생장특성과 엽록소 함량, 파장별 흡광도, 광합성 속도 등 광합성 특성을 조사하였다. 엽면적, 엽병길이 , RGR은 낮은 광조건에서 생장시킨 개체에서 크게 나타났고, SLW는 강한 광조건에서 각각 생장한 개체에서 높았다. 엽록소 함량은 염록소 a, 엽록소 b, 엽록소 a+b 함량 등은 낮은 광조건에서 생장시킨 개체에서 높았고, 엽록소 a/b 율은 강한 광조건에서 각각 생장한 개체에서 높았다. 광합성 유효파장역에서 평균 흡광값은 음엽이 0.75로 양엽의 0.70보다 높았다. 광합성 속도는 강한 광조건에서 생장한 개체가 높은 광합성 속도를 나타내었다. 광포화점은 전광조건 하에서 생육시킨 유묘에서 $700\;{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, 임내광 조건에서 생육시킨 조건에서 $300\;{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$이었고, 생장상의 강광조건에서는 $500{\;}{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, 약광조건에서는 $300{\;}{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$이었다.

산소와 색채 조명 자극의 조합이 스트레스 완화에 미치는 효과: 심리 및 자율신경계 반응을 중심으로 (Effects of the Combination of Oxygen and Color Light on Stress Relaxation: Psychological and Autonomic Responses)

  • 장은혜;김아영;장용원;김보성;최용복;김승철;이상곤;김승환
    • 감성과학
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    • 제22권1호
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    • pp.55-64
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    • 2019
  • 스트레스는 자율신경계 반응의 변화를 수반하며, 특히 심박변이도 지표는 스트레스에 의한 자율신경계의 활동을 반영하는 양적 지표로 사용된다. 본 연구에서는 스트레스 완화를 위한 산소와 색채 조명의 복합 자극이 제시되는 동안 자율신경계 반응의 변화를 확인하였다. 42명의 실험참가자는 지난 2주 동안 경험한 스트레스에 대한 증상들을 스트레스 반응 척도에 평가하였다. 스트레스 평가 후, 실험참가자는 복합 자극을 제시받았고, 자극 제시 전과 후, 그리고 자극이 제시되는 동안 심전도 신호가 기록되었다. 자극 조건은 30% 농도의 산소와 백색 조명, 산소와 주황색 조명과 산소와 파란색 조명의 조합의 세 가지로 구성되었다. 심박률(HR), R-R간격의 표준편차(SDNN), 연속한 R-R 간격 차이 값의 평균제곱근(RMSSD)과 심박변이도의 저주파 성분(LF), 고주파 성분(HF), 그리고 LF와 HF의 비율을 심박변이도 지표로 추출하였다. 이들 지표는 자극 제시 전과 후의 평균을 비교하는데 활용되었다. 결과는 자극 조건이 제시되고 난 후, HR과 LF/HF ratio의 유의한 감소를 보여주었다. 특히, 산소와 파란색 조명이 제시된 조건에서 다른 두 조건보다 유의하게 큰 RMSSD와 HF의 증가 및 LF/HF ratio의 감소가 나타났다. 이는 30% 농도의 산소와 파란색 조명의 조건이 부교감신경의 활성화에 의한 자율신경의 균형을 유발하여 스트레스 이완에 가장 효과적임을 보여주었다.

Identification and Quantification of Glucosinolates in Rapeseed (Brassica napus L.) Sprouts Cultivated under Dark and Light Conditions

  • Lee, Min-Ki;Arasu, Mariadhas Valan;Chun, Jin-Hyuk;Seo, Jeong Min;Lee, Ki-Teak;Hong, Soon-Taek;Kim, In Ho;Lee, Yong-Hwa;Jang, Young-Seok;Kim, Sun-Ju
    • 한국환경농학회지
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    • 제32권4호
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    • pp.315-322
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    • 2013
  • BACKGROUND: This study was performed for the identification and quantification of glucosinolate (GSL) contents in seven varieties of rapeseed (Brassica napus L.) sprouts cultivated under dark and light conditions. METHODS AND RESULTS: Crude glucosinolates (GSLs) were desulfated by treating with aryl sulfatase and purified using diethylaminoethyl sepharose (DEAE) anion exchange column. Individual GSLs were quantified using high-performance liquid chromatography (HPLC) with electrospray ionization-tandem mass spectrometry (ESI-MS/MS). Eleven GSLs including six aliphatic (progoitrin, sinigrin, glucoalyssin, gluconapoleiferin, gluconapin, and glucobrassicanapin), four indolyl (4-hydroxyglucobrassicin, glucobrassicin, 4-methoxyglucobrassicin, and neoglucobrassicin) and one aromatic (gluconasturtiin) were identified based on the fragmentation patterns of MS spectrum. Aliphatic GSLs were noted as the predominant group with average 85.2% of the total contents. The most abundant GSLs were progoitrin which was ranged at $8.14-118.68{\mu}mol/g$ dry weight (DW). The highest total GSL amounts were documented in 'Hanra' ($146.02{\mu}mol/g$ DW) under light condition and 'Mokpo No. 68' ($86.67{\mu}mol/g$ DW) in dark condition, whereas the lowest was in 'Tamra' (30.13 and $14.50{\mu}mol/g$ DW) in both conditions. The sum of aliphatic GSLs attributed > 80% in all varieties, except 'Tamra' (67.7% and 64.9% in dark and light conditions, respectively) in the total GSL accumulation. Indolyl GSLs were ranged $2.41-15.73{\mu}mol/g$ DW, accounted 2.78-33.6% of the total GSLs in rapeseed varieties. CONCLUSION(S): These results provide valuable information regarding potential beneficial GSL contents individually. This study attempts to contribute to knowledge of the nutritional properties of the different varieties of rapeseed plants. These results may be useful for the evaluation of dietary information.

휴게실 공간의 조명환경에 대한 시각적 감지 및 심리적 반응에 따른 공간 인지도 변화 (Variation of Spatial Cognition According to Visual Perception and Psychological Responses for Lighting Environments in Rest Space)

  • 김재상;이지현;김수영
    • 설비공학논문집
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    • 제24권5호
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    • pp.443-453
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    • 2012
  • This study examines visual perception and spatial satisfaction according to lighting conditions. Field measurements and surveys were performed in three rest space of university buildings where various lighting conditions were employed. Results indicate that overall impression of space improved when low color temperature, such as 3,000 K governed overall lighting environment and accent lighting was used for wall surfaces. Lighting conditions that kept uniform illuminance levels using area light sources containing fluorescent lamps with 6,500 K failed to keep favorable spatial satisfaction for space. High color temperature was not recommended for lighting in rest space. Asymmetrical illuminance levels formed by low color temperature such as 3000 K is recommended to keep positive mood and improve spatial satisfaction in rest space. Overall impression of the space was influenced by visual comfort, color temperature, spatial satisfaction and brightness. Spatial satisfaction for space was effectively impacted by psychological comfort, color temperature and overall impression for lighting conditions. Psychological comfort in space was influenced by color temperature, spatial satisfaction and visual annoyance from reflected light.

Roasting and Cryogenic Grinding Enhance the Antioxidant Property of Sword Beans (Canavalia gladiata)

  • Jung, Ju-Yeong;Rhee, Jin-Kyu
    • Journal of Microbiology and Biotechnology
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    • 제30권11호
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    • pp.1706-1719
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    • 2020
  • The objective of this study was to optimize the conditions for enhancing the antioxidant properties of sword bean (Canavalia gladiata) as a coffee substitute in two processing methods, roasting and grinding. The optimum conditions for removing off-flavor of the bean and maximizing functionality and efficiency were light roasting and cryogenic grinding (< 53 ㎛). In these conditions, extraction yield was 16.75%, total phenolic content (TPC) was 69.82 ± 0.35 mg gallic acid equivalents/g, and total flavonoid content (TFC) was 168.81 ± 1.64 mg quercetin equivalents/100 g. The antioxidant properties were 77.58 ± 0.27% for DPPH radical scavenging activity and 58.02 ± 0.76 mg Trolox equivalents/g for ABTS radical scavenging activity. The values for TFC and ABTS radical scavenging activity were significantly higher (p < 0.05) than in other conditions, and TPC and DPPH radical scavenging activity were second highest in lightly roasted beans, following raw beans. HS-SPME/GC-MS analysis confirmed that the amino acids and carbohydrates, which are the main components of sword bean, were condensed into other volatile flavor compounds, such as derivatives of furan, pyrazine, and pyrrole during roasting. Roasted and cryogenically ground (cryo-ground) sword beans showed higher functionality in terms of TFC, DPPH, and ABTS radical scavenging activities compared to those of coffee. Overall results showed that light roasting and cryogenic grinding are the most suitable processing conditions for enhancing the bioactivity of sword beans.

Overexpression of N -terminal lacking mutant HFR1 confers light-independence in a subset of photo-responses

  • Yang Ki-Young;Kim Young-Mi;Song Pill-Soon;Soh Moon-Soo
    • 한국광과학회:학술대회논문집
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    • 한국광과학회 2003년도 학술대회지
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    • pp.97-103
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    • 2003
  • Phytochrome controls diverse aspects of plant development in response to the ambient light conditions. HFRl, a basic helix-loop-helix protein, is required for a subset of phytochrome A (phy A)-mediated photo-responses in Arabidopsis. Here, we show that overexpression of HFR1-N105, but not the one of the full-length HFR1, confers exaggerated photo-responses. The transgenic plants overexpressing HFR1- N105 exhibited light-independence in a subset of photo-responses, including germination, de-etiolation, gravitropic hypocotyl growth, and blocking of greening. Overexpression of HFR1-N105 also caused constitutive light-responses in the expression of some light-regulated genes. In addition, the HFR1-N105 overexpressor showed hypersensitive responses under R and FR light, dependently on phyB and phyA, respectively. End-of-day far-red light response and petiole elongation were suppressed in the HFR1-N105 overexpressor plants. Together these results imply that overexpression of HFR1-N105 activated a branch of light signaling, supporting the hypothesis that transcriptional regulation in the nucleus would be the primary mechanism of light signaling in Arabidopsis. We discuss the biotechnological potential of the mutant bHLH protein, HFR1-N105 in regard to suppressed shade avoidance syndrome.

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Phenolic Compounds Production, Enhancement and Its Antioxidant Activity of Blue Berry Powder with Bacillus subtilis Light Mediated Fermentation Compounds

  • Elumalai, Punniyakotti;Lim, Jeong-Muk;Mohan, Harshavardhan;Lee, Jeong-Ho;Oh, Byung-Taek
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2018년도 춘계학술발표회
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    • pp.66-66
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    • 2018
  • Light fermentation has been conducted under different light conditions such as normal dark light, white light, and light emitting diodes (LEDs) various color (blue, green, red, white on blueberry powder with fermenting bacteria Bacillus subtilis (B2). The bacteria B2 was isolated and identified by 16S rRNA sequencing method. RYRP biologically converted to secondary metabolites through light fermentation in the presence of Bacillus subtilis, the bacteria actively involved in bioconversion process. LEDs fermentation to enhance the production of phenolic content while comparing to normal dark and white light. Among the different color LEDs, blue LEDs mediated fermentation showed higher amount of total phenolic and flavonoid content. Then blue LEDs mediated fermented compound were characterized by FTIR and GC-MS, subsequently the compound was analyzed antioxidant activity tests and the antioxidant activity exhibited higher. This is the first study to demonstrate that B. subtilis-LEDs mediated fermentation is useful for facilitating phenolic compound production and enhancing antioxidant activity, which may have greater application fermentation fields.

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Modeling Green-light Fiber Amplifiers for Visible-light Communication Systems

  • Khushik, Muhammad Hanif Ahmed Khan;Jiang, Chun
    • Current Optics and Photonics
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    • 제3권2호
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    • pp.105-110
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    • 2019
  • The visible-light communication (VLC) system is a promising candidate to fulfill the present and future demands for a high-speed, cost-effective, and larger-bandwidth communication system. VLC modulates the visible-light signals from solid-state LEDs to transmit data between transmitter and receiver, but the broadcasting and the line-of-sight propagation nature of visible-light signals make VLC a communication system with a limited operating range. We present a novel architecture to increase the operating range of VLC. In our proposed architecture, we guide the visible-light signals through the fiber and amplify the dissipated signals using visible-light fiber amplifiers (VLFAs), which are the most important and the novel devices needed for the proposed architecture of the VLC. Therefore, we design, analyze, and apply a VLFA to VLC, to overcome the inherent drawbacks of VLC. Numerical results show that under given constant conditions, the VLFA can amplify the signal up to 35.0 dB. We have analyzed the effects of fiber length, active ion concentration, pump power, and input signal power on the gain and the noise figure (NF).

Through-field Investigation of Stray Light for the Fore-optics of an Airborne Hyperspectral Imager

  • Cha, Jae Deok;Lee, Jun Ho;Kim, Seo Hyun;Jung, Do Hwan;Kim, Young Soo;Jeong, Yumee
    • Current Optics and Photonics
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    • 제6권3호
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    • pp.313-322
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    • 2022
  • Remote-sensing optical payloads, especially hyperspectral imagers, have particular issues with stray light because they often encounter high-contrast target/background conditions, such as sun glint. While developing an optical payload, we usually apply several stray-light analysis methods, including forward and backward analyses, separately or in combination, to support lens design and optomechanical design. In addition, we often characterize the stray-light response over a full field to support calibration, or when developing an algorithm to correct stray-light errors. For this purpose, we usually use forward analysis across the entire field, but this requires a tremendous amount of computational time. In this paper, we propose a sequence of forward-backward-forward analyses to more effectively investigate the through-field response of stray light, utilizing the combined advantages of the individual methods. The application is an airborne hyperspectral imager for creating hyperspectral maps from 900 to 1700 nm in a 5-nm-continuous band. With the proposed method, we have investigated the through-field response of stray light to an effective accuracy of 0.1°, while reducing computation time to 1/17th of that for a conventional, forward-only stray-light analysis.

미세조류 Dunaliella bardawil의 고농도 세포배양 (High Cell Density Culture of Micro-algal Dunaliella bardawil)

  • 정욱진;왕만식;최승인;정병철;김주곤
    • KSBB Journal
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    • 제14권2호
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    • pp.160-166
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    • 1999
  • 본 연구에서는 ($\beta$-carotene 생산균주인 미세조류 Dunaliella bardawil을 사용하여 batch flask에서 미세조류의 고농도세포에 관한 최적배양조건(미량원소, pH, agitation speed, nitrate, phosphate, carbon source)을 확립하고자 하였다. 미량원소는 5X 배지에서 교반하였을 때 비생장속도는 $0.0l3hr^{-l}$와 세포농도는 $4.9{\times}10^6$ cells/mL로서 IX. 3X, lOX 배지에서 배양한 것보다. 약 46%, 18%, 69% 높은 세포수율을 얻었으며 세포배양시 교반한 경우, pH는 80에서 최대 세포농도를 얻었다. 초기 nitrate ($KNO_3$)와 phosphate($KH_2PO_4$)의 영향을 조사한 결과 미세조류 생장에 중요한 영양분으로서 질소원의 주입은 매우 효과적임을 확인하였다. 또힌 탄소원으로서 250mM의 $NaHCO_3$$CO_2$ 가스를 동시에 사용한 배양조건이 500mM $NaHCO_3$만을 탄소원으로 사용한 실험에 비하여 32% 증가된 세포농도를 나타내었다. light는 white light의 경우 blue light보다 세포생장에 적합하였다. 질소원을 이용한 유기배양시 2회의 nitrate주입만으로써 배양 198hr에 $8.955{\times}10^6$cell/mL의 고농도의 세포를 얻었다.

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