• Title/Summary/Keyword: Sunlight reflection properties

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Influence to give to a performance evaluation and sunlight reflection properties of the building crustal material (건물외피 재료의 성능평가와 일사반사 특성에 미치는 영향)

  • Sang, Hie-Sun;Kwak, Sung-Gun;Lee, Jeung-Seok;Yoshida, Atsumada
    • 한국태양에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.177-186
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    • 2011
  • We can expect reduction of the sunlight absorption quantity to a structure and an earth surface, a decline of the surface temperature and a decline of the heat transport volume in what there is a method I give the sunlight reflectance in the aspect to the surface of the building by painting sunlight high reflectance paint, and to reduce the sunlight absorption quantity to a structure and an earth surface and does so, and, in addition, a method high water retentivity of tree planting and the road surface of the city space uses evaporation latent heat of the water by making it, and to restrain a rise in temperature is thought about. and It is thought that I reduce the sunlight absorption quantity to not only the structure but also other structures and attention gathers to the reflexive reflector reflecting in the direction again and it is wide as a marker of a board and the clothing of the traffic sign and is used the incidence energy from a source of light for this reflexive reflector now by there is it and devises surface structure again, and controlling reflection directivity for the sunlight for the purpose of raising night visibility.

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The optical properties of columnar structure according to the growth angles of ZnO thin fims (성장각도에 따른 주상구조 ZnO 박막의 광학적 특성)

  • Ko, Ki-Han;Seo, Jae-Keun;Kim, Jae-Kwang;Kang, Eun-Kyu;Park, Mun-Gi;Ju, Jin-Young;Shin, Yong-Deok;Choi, Won-Seok
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.127-127
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    • 2009
  • The most important part of the fabrication solar cells is the anti-reflection coating when excludes the kinds of silicon substrates (crystalline, polycrystalline, or amorphous), patterns and materials of electrodes. Anti-reflection coatings reduce the reflection of sunlight and at last increase the intensity of radiation to inside of solar cells. So, we can obtain increase of solar cell efficiency about 10% using anti-reflection coating. There are many kinds of anti-reflection film for solar cell, such as SiN, $SiO_2$, a-Si, and so on. And, they have two functions, anti-reflection and passivation. However such materials could not perfectly prevent reflection. So, in this work, we investigated the anti-reflection coating with the columnar structure ZnO thin film. We synthesized columnar structure ZnO film on glass substrates. The ZnO films were synthesized using a RF magnetron sputtering system with a pure (99.95%) ZnO target at room temperature. The anti-reflection coating layer was sputtered by argon and oxygen gases. The angle of target and substrate measures 0, 20, 40, 60 degrees, the working pressure 10 mtorr and the 250 W of RF power during 40 minutes. The confirm the growth mechanism of ZnO on columnar structure, the anti-reflection coating layer was observed by field emission scanning electron microscopy (FE-SEM). The optical trends were observed by UV-vis and Elleso meter.

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SIMULATION OF CLOUD'S VISIBLE REFLECTION USING MODIS CLOUD PRODUCTS

  • Ham, Seung-Hee;Sohn, Byung-Ju
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.668-671
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    • 2006
  • Radiative transfer modeling of ice clouds is developed. Ice clouds located near tropopause reflect most of sunlight, thus atmospheric and surface effects can be minimized. Cloud properties such as cloud optical thickness (COT) and effective radius are important parameters to determine the magnitude of reflectance, while atmospheric and surface parameters rarely affect reflectance value. For selected homogeneous cloud pixels of MODerate Resolution Imaging Spectroradiometer (MODIS) observation, reflectances are calculated using MODIS cloud products as inputs of radiative transfer model (RTM). For three types of phase function (Henyey-Greenstein, Garcia-Siewert, Baum) calculated reflectances are compared with observations for validation. All cases show linear relationship between simulated values and measured values, however each represent different bias and slope. The result shows that phase function determine angular distribution of reflectance.

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A Study on Rheology Characteristics of Ag Paste for Screen Printing Method for Silicon Solar Cells Electrodes Capable of Forming High Aspect Ratio (고온 소결형 실리콘 태양 전지의 High Aspect Ratio 전극 형성이 가능한 Ag 페이스트의 레오로지 특성 연구)

  • Oh, Tae-Hun;Kim, Sung-Bin;Nam, Su-Yong
    • Journal of the Korean Graphic Arts Communication Society
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    • v.28 no.1
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    • pp.15-24
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    • 2010
  • Photovoltaic solar cells are all in the incident because they are not converted into electrical energy, high-efficiency solar cells in order to reduce the loss of elements must be. Significant factor in the loss of solar cells, optical loss and electrical loss can be divided into. Optical losses occur when the sun will be joined on the surface of the reflection, the shadow loss due to electrodes, and the losses are in the solar wavelengths. Commercialization is currently the most common solar cells on the front of the light incident on the electrode is formed. Therefore, the shadow caused by the electrode to cover the dead area of the sun, due to factors that hinder the absorption of sunlight which is shadowing them and conversion efficiency of solar cells is the inhibition factor. These barriers to eliminate the electrode linewidth reduces the shadowing to reduce, but simply of the electrode line width is reduced electrode area by reducing the series resistance elevates this because to improve the electrode Aspect ratio(height/width) to increase Ag development of paste is required. In this study, aspect ratio of screen-printing method to increase the electrode Ag paste composition of the binder for the characterization of rheology in the shadow of the electrode by reducing the optical loss of the photoelectric conversion efficiency of solar cells to boost the performance measures was. Properties and printability of the paste, the binder resin sintered characteristics that affect the thermal properties are excellent with a good screen printability acrylic resin, ethyl cellulose, using a resin were evaluated. Prepared paste rheology properties, was formed to evaluate the electrode conductivity and aspect ratio.

Possibility and Accuracy of Extracting Room Temperature Information from Mid-Infrared Sensor Satellite Images (중적외선 센서 위성 영상의 상온 온도 정보 추출 가능성 및 정확도)

  • Choi, SeokWeon;Seo, DooChun;Lee, DongHan
    • Journal of Space Technology and Applications
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    • v.1 no.3
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    • pp.356-363
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    • 2021
  • It was common knowledge in textbooks that images acquired using mid-infrared ray were not suitable for measuring temperature near room temperature. But a recent satellite image using a mid-infrared sensor show the possibility that the result measured using the mid-infrared sensor can also measure the temperature near room temperature. In this paper, the possibility and accuracy of extraction room temperature information from satellite images with mid-infrared sensors are reviewed. The mid-infrared satellite image reviewed in this paper showed the temperature of room temperature well, and regarding the reliability as an absolute value of the measured temperature, the effect of the heat transfer amount due to the direct reflection of sunlight on the surface and the effect of the infrared absorption amount absorbed in the atmosphere can be seen as a relatively small or constant value. However, the problem of uncertainty in the radiation coefficient due to physical properties, which is the limit of the non-contact thermometer, remained a problem to be solved.