• 제목/요약/키워드: Photon density

검색결과 228건 처리시간 0.026초

Dye-sensitized solar cells using size dependent SBM binder

  • 박경희;김은미;조홍관;왕교;홍창국;구할본
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 추계학술대회 논문집
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    • pp.116-116
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    • 2009
  • $TiO_2$ pastes was synthesized to obtained of high efficiency dye-sensitized solar cells using size dependent co-polymer. SBM co-polymer binder is consist of styrene, n-butyl acrylate, and methacrylic acid (SBM) monodisperse co-polymer binder materials and this $TiO_2$ pastes were applied of dye-sensitized solar cells (DSSCs). The photoanodes were characterized by ATR-Fourier Transform spectrometer, X-ray diffraction (XRD) and morphology was investigated by field emission scanning electron microscopy (FE-SEM). The photoelectrochemical properties of the thin films and the performance of DSSCs were measured by photovoltaic-current density, AC impedance and monochromatic incident photon-to-current conversion efficiency (IPCE). DSSC based on the 100nm size co-polymer binder was obtained conversion efficiency of 8.1% under irradiation of AM 1.5(100 $mWcm^2$).

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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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    • 제2권3호
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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.

식물공장 각종광원의 방사조건과 LED조명의 활용에 관한 연구 (A Study on the Various Light Source Radiation Conditions and use of LED Illumination for Plant Factory)

  • 윤철구;최홍규
    • 조명전기설비학회논문지
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    • 제25권10호
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    • pp.14-22
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    • 2011
  • The artificial lights to be introduced for the plant factories is requiring the artificial light resources with minimizing the energy consumption to reduce the greenhouse gases which is a major cause of global warming, and maximizing the efficiency in photosynthesis effect light-wave range, in which the plants can be greatly grown and developed, and having the signal light-wave range for forming the light types. the best growing and developing environment for the plants has recently realized with utilizing the LED(Lighting Emitting Diode) lamps, as a environment-friendly green lamps, which can elevating the light efficiency with using only the specific light wave range. In this study, to provide the necessary lights for the full artificial light type of the plant factory, the following research/study and experiments has been conducting. experiments of the spectrum for each light sources, and LED, The intensity of illumination, Irradiance, Photosynthesis Photon Flux Density.

Erbium 도핑된 p-GaSe 단결정의 홀 효과 특성 (Hall-effect properties of single crystal semiconductor P-GaSe dopes with $Er^{3+}$)

  • 이우선;오금곤;정용호;정창수;손경춘;김남오
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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    • pp.726-728
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    • 1998
  • Optical and electrical properties of GaSe:$Er^{3+}$ single crystals grown by the Bridgeman technique was been investigated by using optical absorption and Hall-effect measurements. The Hall coefficients were measured by using a high impedance electrometer in the temperature range from 360K to 150K. The temperature dependence of hole concentration shows the characteristic of a partially compensated p-type semiconductor. carrier density($N_H$) of GaSe doped with Erbium was measured about $3.25{\times}10^{16}\;[cm^{-3}}$ at temperature 300K, which was high than undoped specimen. Photon energy gap ($E_{gd}$) was measured about 1.7geV.

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인삼 엽록체의 미세구조와 Photobleaching (Ultrastructural Feature and Photobleaching of ginseng Chloroplasts)

  • 양덕조;김명원
    • Journal of Ginseng Research
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    • 제14권3호
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    • pp.416-420
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    • 1990
  • Ultrastructural and anatomical features of the leaf were studied in Panax ginseng C.A. Meyer(ginseng). The ginseng leaf poorly developed palisade tissue and the size of mesophyll cell was larger and the chloroplast density was lower than that of Glycine max (soyben). Ginseng chloroplast was filled with highly stacked grana and condensely-arrayed thylakoid, so the stroma space was hardly absorbed. However, ginseng mesophyll tissue and chloroplast array did not reduce light energy entering the mesophyll chloroplast, and the high LHCP/CP ratio of ginseng thylakoid resulted in the absorption of excess photon. It is reasonable to assume that 1O1-photogenearation by excess light energy partially resulted from the anatomical and ultrastructural characteristics of the ginseng leaf.

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방사선조사가 골무기질함량에 미치는 영양에 관한 실험적 연구 (AN EXPERIMENTAL STUDY ON THE CHANGE OF BONE MINERAL METABOLISM AFTER IRRADIATION)

  • 진해윤;이상래
    • 치과방사선
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    • 제18권1호
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    • pp.53-66
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    • 1988
  • Irradiation is widely used for the treatment of malignant diseases, and possibly cause the osteoporosis. The bone densitometry and bone scintigraphy are valuable when used to monitor the patients longitudinally to access the progression of osteoporosis and risk of osteoradionecrosis. To evaluate the osteoporosis after irradiation of cobalt-60 gamma ray on the lumbar spines of New Zealand white rabbits, bone densitometry by dual photon absortiometry and bone scintigraphy were performed weekly. The decrease of bone density began at the first week after irradiation, and were in the nadir at 4-6th week. The osteoblastic activity measured by bone scintigraphy decreased in the first week, and was in the nadir at 4-6th week. The severity of these changes were related to the radiation dose. In conclusion, the osteoporosis before presentation of the osteoradionecrosis can be developed at low dose irradiation and confirmed by bone densitometry, bone scanning, and histopathology.

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식물재배를 위한 최적LED 배열조합설계 (LED array design for optimal combination of plant grown)

  • 이성원;박세광
    • Journal of Plant Biotechnology
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    • 제41권3호
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    • pp.123-126
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    • 2014
  • This paper is suitable for household plant factory by design and using both energy-saving LED and solar technology. Conventional household plant factory only depending on natural sunlight is sensitive for the change of external environment. Another a big problem of conventional common household plant factory is large power consumption. Recently interest in wellbeing food such as chemical-free is increased abruptly. To solve these two problems, this paper describes hybrid type of household plant. In particular, reducing the power photosynthesis photon flux density (PPFD) is kept uniform to enhance the growth of the plant. Ambient light sensor is adopted for the control of proper combination of sunlight and LED to keep PPFD constant.

Erbium 도핑된 p-GaSe 단결성의 홀 효과 특성 (Hall-effect Properties of Single Crystal Semiconductor p-GaSe Dopes with $Er^{3+}$)

  • 이우선;김남오;손경춘
    • 한국전기전자재료학회논문지
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    • 제13권1호
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    • pp.1-5
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    • 2000
  • Optical and electrical properties of GaSe:Er\ulcorner single crystals grown by the Bridgenman technique have been investigated by using optical absorption and h\Hall-effect measurement system. The Hall coefficients were mea-sured by using a high impedance electrometer in the temperature range from 360K to 150K. The temperature dependence of hole concentration show the characteristic of a partially compensated p-type semiconductor. Carrier density(N\ulcorner) of GaSe doped with Erbium was measured about 3.25$\times$10\ulcorner [cm\ulcorner] at temperature 300K, which was higher than undoped specimen. Photon energy gap (E\ulcorner) of GaSe:Er\ulcorner specimen was measured about 1.79eV.

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