• 제목/요약/키워드: light-time effect

검색결과 1,066건 처리시간 0.041초

큰달맞이꽃 종자발아(種子發芽)에 영향하는 요인(要因)과 광간(光間)의 상호작용(相互作用) (Interaction between Light and other Factors Affecting Germination of Oenothera lamarckiana Ser. Seed.)

  • 김진석;황인택;구석진;조광연
    • 한국잡초학회지
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    • 제8권1호
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    • pp.15-22
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    • 1988
  • 본(本) 연구(硏究)는 큰달맞이꽃종자(種子)의 발아(發芽)에 미치는 광(光)의 생리적작용(生理的作用)을 파악(把握)하기 위하여 발아요인(發芽要因)들(광질(光質), 저온(低溫), 변온(變溫), 수분(水分), 산십(酸十), 종피(種皮) 등) 상호작용(相互作用)을 광(光)과 관련(關聯)하여 검토(檢討)하였다. 광(光)은 혐기조건(嫌氣條件) 및 낮은 water potential (-18bars) 하(下)에서도 발아초기(發芽初期) 단계(段階)를 유기(誘起)시키며 종피(種皮)보다는 비(飛)의 활력(活力)에 영향을 미쳐 발아율(發芽率)을 증가(增加)시켰다. 이러한 광(光)의 효과(效果)중 청색광(靑色光)처리에 의해서는 억제(抑制)되었다. 이는 가역적(可逆的) 반응(反應)을 보였으며 그 정도(程度)는 광(光)의 세기가 높고, 조사기간(照射期間)이 길수록 높은 경향(傾向)이었다. 저온(低溫), 변온(變溫), 종피연화처리(種皮軟化處理) 및 광(光) 등은 발아유기(發芽誘起)에 정(正)의 상호작용(相互作用)을 보였으나 단색광(單色光) 처리(處理)에서는 저온(低溫)의 발아유기효과(發芽誘起效果)를 오히려 저해(沮害)하는 경향(傾向)이었다. 기타 pH 용액(溶液) 및 $GA_3$ 용액(溶液)은 광(光) 및 암발아(暗發芽)와는 무관(無關)하였다.

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광중합형 복합레진의 중합시간과 거리에 따른 중합도의 변화 (A STUDY ON THE CHANGES IN POLYMERIZATION OF LIGHT-ACTIVATED COMPOSITE RESIN WITH VARIOUS EXPOSURE TIME AND DISTANCE)

  • 안명기;정태성;김신
    • 대한소아치과학회지
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    • 제28권2호
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    • pp.293-299
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    • 2001
  • 본 연구에서는 광중합형 복합레진을 대상으로 중합거리와 시간의 변화에 따른 중합도와 거리에 따른 적절한 중합시간을 알아보기 위하여 일정 중합 광도하에서 중합거리와 시간을 달리하여 재료의 표면과 2mm 하방의 미세경도를 측정한 후 이를 통하여 간접적으로 중합도를 평가하였다. 광중합형 복합레진으로 Z100과 Z250을 사용하였고 각 재료별로 조사단과의 거리가 0, 2, 4, 6mm인 상태에서 20, 30, 40, 60, 80초간 광조사를 시행하였다. 중합 후 표층과 내층의 경도를 미세경도 측정기로 측정하였다. 측정치를 통계처리하여 다음과 같은 결과를 얻었다. 1. 거리의 증가에 따라 상대광도는 2mm이상에서 급격히 감소하였다(p<0.05). 2. 미세 경도는 상대광도와 조사시간의 증가에 따라 표층 및 내층에서 모두 증가하였다(p<0.05). 3. 내층이 표층에 비해 상대적으로 중합거리와 시간의 영향을 많이 받았다(p<0.05). 4. 조사 시간의 증가에도 불구하고 Z100 시편에서 중합거리가 4mm 이하군과 6mm군에서, Z250 시편에서는 2mm 이하군과 4mm 이상군에서 내층의 미세 경도 차이가 비교적 크게 나타났다(p<0.05).

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미분무수 분사의 제연효과 (Smoke Removal Effect by Water Mist Spraying)

  • 박태성;공하성;김명철
    • 한국화재소방학회논문지
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    • 제29권3호
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    • pp.43-47
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    • 2015
  • 구획된 소규모 공간내부에 각 경우별로 서로 다른 두 종류의 가연물로부터 발생된 연기(smoke)를 채운 후 미분무 헤더를 통해 분사압력과 분사시간을 서로 달리하면서 미분무를 분사하였으며, 이후 시간경과에 따른 광소멸상수의 변화 값을 측정하였다. 미분무가 구획된 공간내부에서 분사될 경우 각각의 실험조건에 따른 연기제거효과의 패턴과 차이점은 감광식 연기농도계를 통해 고찰하였다. 실험에 이용된 감광식 연기농도계를 통해 시간변화에 따른 연기밀도의 변화값을 직류전압(DC voltage)의 변화값으로 확보할 수 있었으며, 이를 통해서 광소멸상수의 변화를 알 수 있었다. 훈소(glowing)에서 발생한 연기가 불꽃연소(flaming combustion)에서 발생한 연기보다 연기의 제거효과가 컸으며, 분사압력이 높을수록, 분사시간이 길수록 연기제거효과는 크게 나타났다.

Effect On Glass Texturing For Enhancement of Light Trapping in Perovskite Solar Cells

  • Kim, Dong In;Nam, Sang-Hun;Hwang, Ki-Hwan;Lee, Yong-Min;Boo, Jin-Hyo
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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    • pp.387.2-387.2
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    • 2016
  • Glass texturing is a sufficient method for changing the surface morphology to enhance the light trapping. In this study, glass texturing was applied to the perovskite solar cell for improving the current density. Glass substrates (back-side glass of FTO coated glass substrate) were textured by randomly structure assisted wet etching process using diluted HF solution at a constant concentration of etchants (HF:H2O=1:1). Then, the light trapping properties of suitable films were controlled over a wide range by varying the etching time (1, 2, 3, 4 and 5 min.). The surface texturing changed the reflected light in an angle that it can be reflected by substrate glass surface. As a result, Current density and cell efficiency were affected by light trapping layer using glass texturing method in perovskite solar cells.

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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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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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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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인접한 동영상 프레임의 차영상을 이용한 디스플레이 주변 조명효과의 제어 (An Ambient Light Control System using The Image Difference between Video Frames)

  • 신수철;한순흥
    • 한국시뮬레이션학회논문지
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    • 제19권3호
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    • pp.7-16
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    • 2010
  • 본 논문은 비디오 및 게임 영상에서 인접한 프레임의 차영상을 이용하여 디스플레이 주변의 조명 장치를 제어하는 방법을 제안한다. 제안된 방법은 현재 프레임의 대표 색상을 추출하는 단계, 이전 프레임과의 차영상으로부터 변화량을 측정하고 변화 색상을 추출하는 단계, 새로운 대표 색상을 생성하는 단계의 세 단계로 구성된다. 변화량을 측정하기 위해 이미지를 사람 지각 시스템에 가까운 YUV 색공간으로 변환하고 차영상을 구한 후, 각 화소별 색차의 합을 변화량으로 사용하였다. 새로운 대표색상은 변화량에 비례하여 변화색상을 반영한다. 제안한 방법의 성능을 평가하기 위해 동일한 동영상에 대하여 시간에 따른 조명 효과의 변화 양상을 비교하였다. 실험 결과 기존 방법보다 더 역동적인 조명효과를 보이는 것을 확인하였다.

디젤입자상물질필터의 기하학적 형상변화가 재생과정 중 활성화 특성 및 비정상 온도거동에 미치는 영향에 관한 수치적 연구 (Numerical Study on the Effect of Changes of Geometric Shape of Diesel Particulate Filter on Light-Off Characteristics and Transient Thermal Behavior during Regeneration)

  • 정수진;이상진;김우승;이춘범
    • 한국자동차공학회논문집
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    • 제14권4호
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    • pp.68-76
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    • 2006
  • The minimization of maximum DPF wall temperature and the fast Light-off during regeneration are the targets for the high durability of the DPF system and the high efficiency of regeneration. In order to predict transient thermal response of DPF, one-channel numerical modeling has been adopted. The effect of the ratio of length to diameter(L/D), cell density, the amount of soot loading on temporal thermal response and regeneration characteristics has been numerically investigated under two different running conditions: city driving mode and high speed mode. The results indicate that the maximum wall temperature of DPF increase with increasing 'L/D' in 'High speed mode'. For 'City driving mode', the maximum wall temperature decreases with increasing 'L/D' in the range of $'L/D{\geq}0.6'$. The maximum temperature decreases with increasing cell density because heat conduction and heat capacity are increased. It is also found that the effect of amount of soot loading on light-off time is negligible.

소각비산재로 제조한 광촉매 흡착제의 벤젠과 톨루엔 제거특성 (Removal of Benzene and Toluene by Photo-catalyst Adsorbent Prepared from MSWI Fly Ash)

  • 최소영;심영숙;이우근
    • 한국대기환경학회지
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    • 제21권4호
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    • pp.431-438
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    • 2005
  • In order to apply the photocatalytic decomposition of aromatic VOCs, adsorbent prepared from MSWI fly ash was coated by $TiO_2$ solution to endow with photo-catalytic function. The effects of coating number, existence of light source and the type of $TiO_2$ solution used for coating were examined. Adsorbent coated with amorphous $TiO_2$ solution showed higher adsorptivity than adsorbent coated with crystal $TiO_2$ solution. Without light source, breakthrough curve of photo -catalyst absorbent for VOCs removal was similar to that of absorbent made from MSWI fly ash. On the other hand, breakthrough time was enlarged with light source and total removal efficiency of benzene and toluene was also increased. It can be explained as photo-decomposition effect of $TiO_2$ photo-catalyst. Total removal efficiency of benzene and toluene was increased according to the increase of coating number with light source. It was due to the effect of adsorption and photo reaction of photo-catalytic adsorbent. But total removal efficiency of benzene was lower than that of toluene. Because benzene was removed more effectively than toluene by adsorption, but photo - decomposition effect oi toluene was more high than benzene.

Growth Characteristics of Ultrahigh-density Microalgal Cultures

  • Richmond, Amos
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제8권6호
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    • pp.349-353
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    • 2003
  • The physiological characteristics of cultures of very high cell mass (e.g. 10g cell mass/L), termed“ultrahigh cell density cultures”is reviewed. A close relationship was found between the length of the optical path (OP) in flat-plate reactors and the optimal cell density of the culture as well as its areal (g m$\^$-2/ day$\^$-1/) productivity. Cell-growth inhibition (GI) unfolds as culture density surpasses a certain threshold. If it is constantly relieved, a 1.0cm OP reactor could produce ca. 50% more than reactors with longer OP, e.g. 5 or 10cm. This unique effect, discovered by Hu et al. [3], is explained in terms of the relationships between the frequency of the light-dark cycle (L-D cycle), cells undergo in their travel between the light and dark volumes in the reactor, and the turnover time of the photosynthetic center (PC). In long OP reactors (5cm and above) the L-D cycle time may be orders of magnitude longer than the PC turnover time, resulting in a light regime in which the cells are exposed along the L-D cycle, to long, wasteful dark periods. In contrast, in reactors with an OP of ca. 1.0 cm, the L-D cycle frequency approaches the PC turnover time resulting in a significant reduction of the wasteful dark exposure time, thereby inducing a surge in photosynthetic efficiency. Presently, the major difficulty in mass cultivation of ultrahigh-density culture (UHDC) concerns cell growth inhibition in the culture, the exact nature of which is awaiting detailed investigation.

Characteristics of Motion-blur Free TFT-LCD using Short Persistent CCFL in Blinking Backlight Driving

  • Han, Jeong-Min;Ok, Chul-Ho;Hwang, Jeoung-Yeon;Seo, Dae-Shik
    • Transactions on Electrical and Electronic Materials
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    • 제8권4호
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    • pp.166-169
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    • 2007
  • In applying LCD to TV application, one of the most significant factors to be improved is image sticking on the moving picture. LCD is different from CRT in the sense that it's continuous passive device, which holds images in entire frame period, while impulse type device generate image in very short time. To reduce image sticking problem related to hold type display mode, we made an experiment to drive TN-LCD like CRT. We made articulate images by turn on-off backlight, and we realized the ratio of Back Light on-off time by counting between on time and off time for video signal input during 1 frame (16.7 ms). Conventional CCFL (cold cathode fluorescent lamp) cannot follow fast on-off speed, so we evaluated new fluorescent substances of light source to improve residual light characteristic of CCFL. We realized articulate image generation similar to CRT by CCFL blinking drive and TN-LCD overdriving. As a result, reduced image sticking phenomenon was validated by naked eye and response time measurement.