• Title/Summary/Keyword: Solar light

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Validation and Development of Artificial Sky Dome Facilities with a Heliodon (인공 천공돔과 헬리오돈의 개발 및 성능실험 사례 연구)

  • Kim, Jeong-Tai;Kim, Gon
    • KIEAE Journal
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    • v.3 no.1
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    • pp.21-29
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    • 2003
  • Scale model measurements should be conducted under an actual sky or in a simulated sky where conditions can be held constant. A number of successful attempts have been made to develop artificial sky domes with man-made sun emulators. With reference to formerly-developed examples, sky simulator facility has recently been activated in oder to provide desirable sky conditions for teaching and studies. The structure is a 6m-diameter dome and promises to set various condition for energy related and lighting research activities. The sky dome is also equipped a heliodon, the tilt table, to facilitate additive direct sun impact under clear skies. Shading studies, using scale models with the heliodon, reveal how a building's design blocks or permits light's passage to the interior; solar access studies, and tests of the reflection and transmittance characteristics of new daylighting technologies. The design and construction specification and the initial operating experience with a building configuration are reported.

MoOx/Si Heterojunction for High-Performing Photodetector (MoOx 기반 실리콘 이종접합 고성능 광검출기)

  • Park, Wang-Hee;Kim, Joondong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.29 no.11
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    • pp.720-724
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    • 2016
  • Transparent n-type metal-oxide semiconductor of $MoO_x$ was applied on a p-type Si substrate for high-performing heterojunction photodetector. The formation of $MoO_x$ on Si spontaneously established a rectifying current flow with a high rectification ratio of 1,252.3%. Under light illumination condition, n-type $MoO_x$/p-type Si heterojunction device provided significantly fast responses (rise time : 61.28 ms, fall time : 66.26 ms). This transparent metal-oxide layer ($MoO_x$) would provide a functional route for various photoelectric devices, including photodetectors and solar cells.

SPECTRAL DIAGNOSTICS OF THE ENERGETIC PARTICLES IN SOLAR FLARES

  • FANG C.;DING M. D.;HENOUX J. C.;GAN W. Q.
    • Journal of The Korean Astronomical Society
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    • v.29 no.spc1
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    • pp.295-298
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    • 1996
  • Non-LTE calculations, with the non-thermal ionization effects included, indicated that for electron bombardment, the H$\alpha$ line is widely broadened and shows a strong central reversal. Significant enhancements at the line wings of Ly$\alpha$ and Ly$\beta$ are also predicted at the beginning of the impulsive phase of flares. For the proton bombardment, no strong broadening and no large central reversal are expected. However, due to proton-hydrogen charge exchange, the enhancements at the red wings of Ly$\alpha$ and Ly$\beta$ lines at the early impulsive phase of flares are significant. Our results show that the electron beam can also in some cases generate visible and UV continuum emission in white-light flares. However, at the onset phase, a negative flare may appear within several seconds, due to the increase of the H- opacity. Another spectroscopic signature of energetic particles, i.e. the impact polarization of atomic lines, is also mentioned.

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A Study on the Design Methods of PV System for Apartment Building Application (공동주택의 태양광발전 시스템 적용을 위한 설계방법에 관한 연구)

  • Yi, So-Mi;Lee, Yong-Ho
    • New & Renewable Energy
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    • v.4 no.4
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    • pp.10-16
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    • 2008
  • Nowaday, The Sustainable Development about global environment is the most important subject. In urban environment, a variety of the nature energy utilization such as the solar energy are the most efficient solution to solve this issue. One of these efficient solutions, a photovoltaic system using sunlight has been introduced to the building with an advantage such as cost-effective, safe for using and good for environment friendly in light with energy utilization. Recently, many of the apartment housings are built in domestic country. The apartment buildings have been constructed since early of 1970's. now apartment is taking over 50% out of entire housing in korea. The apartment housing applying to a photovoltaic system has been extensively studied in the foreign country but our county runs short. So, It was necessary to technical development of PV application which is suitable in Korean house culture. The objective of this study is to develop the building integrated PV application method for apartment building.

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The Development of PV-Batttery Driven LED Security Lighting (태양광 배터리 하이브리드 시스템 기반 LED 보안등 개발)

  • Go, Seok-Il;Ahn, Seon-Ju;Park, Byeong-Ha;Choi, Joon-Ho
    • 한국태양에너지학회:학술대회논문집
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    • 2012.03a
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    • pp.433-438
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    • 2012
  • LED is expected as an environmentally friendly next generation light source with its good reliability and long lifetime. In this paper, we propose the PV-Battery Driven LED Security Lighting using the LabVIEW program. The remote monitoring is a program for monitoring the voltage and current that made from PV-Battery Driven LED security lighting in remote area. The main subject of this paper is about making the more useful monitoring program to get and save the data from LED Security Lighting. We develop a prototype of the proposed system.

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Development of Click Chemistry in Polymerization and Applications of Click Polymer

  • Karim, Md. Anwarul
    • Rubber Technology
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    • v.13 no.1
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    • pp.1-9
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    • 2012
  • Click chemistry had enjoyed a wealthy decade after it was introduced by K.B.Sharpless and his co-worker on 2001. Since there is no optimized method for synthesis of click polymer, therefore, this paper introduced three click reaction methods such as catalyst, non-catalyst and azide-end capping for fluorene-based functional click polymers. The obtained polymers have reasonable molecular weight with narrow PDI. The polymers are thermally stable and almost emitted blue light emission. The synthesized fluorene-based functional click polymers were characterized to compare the effect of click reaction methods on polymer electro-optical properties as well as device performance on quasi-solid-state dye sensitized solar cells (DSSCs) applications. The DSSCs with configuration of $SnO_2:F/TiO_2/N719$ dye/quasi-solid-state electrolyte/Pt devices were fabricated using these click polymers as a solid-state electrolyte components. Among the devices, the catalyzed click polymer composed device exhibited a high power conversion efficiency of 4.62% under AM 1.5G illumination ($100mW/cm^2$).These click polymers are promising materials in device application and $Cu^I$-catalyst 1, 3-dipolar cycloaddition click reaction is an efficient synthetic methodology.

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

  • Lee, Sungwon;Park, Sekwang
    • Journal of Plant Biotechnology
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    • v.41 no.3
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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.

POLARIZATION AND POLARIMETRY: A REVIEW

  • Trippe, Sascha
    • Journal of The Korean Astronomical Society
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    • v.47 no.1
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    • pp.15-39
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    • 2014
  • Polarization is a basic property of light and is fundamentally linked to the internal geometry of a source of radiation. Polarimetry complements photometric, spectroscopic, and imaging analyses of sources of radiation and has made possible multiple astrophysical discoveries. In this article I review (i) the physical basics of polarization: electromagnetic waves, photons, and parameterizations; (ii) astrophysical sources of polarization: scattering, synchrotron radiation, active media, and the Zeeman, Goldreich-Kylafis, and Hanle effects, as well as interactions between polarization and matter (like birefringence, Faraday rotation, or the Chandrasekhar-Fermi effect); (iii) observational methodology: on-sky geometry, influence of atmosphere and instrumental polarization, polarization statistics, and observational techniques for radio, optical, and $X/{\gamma}$ wavelengths; and (iv) science cases for astronomical polarimetry: solar and stellar physics, planetary system bodies, interstellar matter, astrobiology, astronomical masers, pulsars, galactic magnetic fields, gamma-ray bursts, active galactic nuclei, and cosmic microwave background radiation.

Platinum nanocomposites and its applications: A review

  • Sharon, Madhuri;Nandgavkar, Isaac;Sharon, Maheshwar
    • Advances in materials Research
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    • v.6 no.2
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    • pp.129-153
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    • 2017
  • Platinum is a transition metal that is very resistant to corrosion. It is used as catalyst for converting methyl alcohol to formaldehyde, as catalytic converter in cars, for hydrocracking of heavy oils, in Fuel Cell devices etc. Moreover, Platinum compounds are important ingredient for cancer chemotherapy drugs. The nano forms of Platinum due to its unique physico-chemical properties that are not found in its bulk counterpart, has been found to be of great importance in electronics, optoelectronics, enzyme immobilization etc. The stability of Platinum nanoparticles has supported its use for the development of efficient and durable proton exchange membrane Fuel Cells. The present review concentrates on the use of Platinum conjugated with various metal or compounds, to fabricate nanocomposites, to enhance the efficiency of Platinum nanoparticles. The recent advances in the synthesis methods of different Platinum-based nanocomposites and their applications in Fuel Cell, sensors, bioimaging, light emitting diode, dye sensitized solar cell, hydrogen generation and in biosystems has also been discussed.

A Study on Optimal Dye-coating Conditions to Reduce Dye-adsorption Time with Improved DSSC Efficiency

  • Seo, Yeong-Ho;Choe, Eun-Chang;Hong, Byeong-Yu
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.481.1-481.1
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    • 2014
  • Dye-sensitized solar cell (DSSC) has been extensively investigated as the next generation energy source. Despite attractive features of simple fabrication process and its economical efficiency, there are some problems such as low efficiency and low long-term stability. Many groups have attempted the proposed way to improve the cell efficiency and long-term stability such as low recombination rate between $TiO_2$ surface and electrolyte, the development of new dye molecules capable of light adsorption as broadly as possible, the fabrication of a solid-state DSSC by replacing the liquid electrolyte, and protective coating on glass. In this work, we confirmed new dye-coating conditions to maximize the dye adsorption between the dye and $TiO_2$ nanoparticle surface. The experiment results coating conditions with the coating temperature of $70^{\circ}C$, the dye concentration of 10 mM and the coating time of 3 min. Conditions have two times, three times cycle the experiment in progress efficiency rises.

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