• Title/Summary/Keyword: ultra-light

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Photon-counting digital holography

  • Hayasaki, Yoshio
    • Proceedings of the Optical Society of Korea Conference
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    • 2009.10a
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    • pp.165-166
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    • 2009
  • A hologram was recorded with two-dimensional scanning of an optical fiber connected to a single-photon counting detector under ultra-weak illumination. The object image was clearly reconstructed in a computer from the hologram. The dependence of hologram quality on the illumination light intensity was estimated.

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The High Strength Steels for Light Car Body and its Welding Technology (승용차 차체 경량화를 위한 고강도강재 및 용접기술)

  • 이목영;김기철;권영각
    • Journal of Welding and Joining
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    • v.22 no.3
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    • pp.18-22
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    • 2004
  • 1990년대에 접어들면서 미국 유럽 등 선진국을 중심으로 환경유해물질 배출 및 안전에 대한 규제가 강화되었다. 미국 캘리포니아주에서는 2005년부터 저공해차 (SULEV; Super Ultra Low Emission Vehicle)의 판매비중을 10%로 의무화하고 있다.(중략)

Response of Growth and Development of Young Tomato Plants to End-of-day Monochromatic Light from Various LEDs

  • Khoshimkhujaev, Bekhzod;Kwon, Joon Kook;Lee, Jae Han;Choi, Hyo Gil;Park, Kyoung Sub;Kang, Nam Jun
    • Journal of agriculture & life science
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    • v.50 no.5
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    • pp.1-9
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    • 2016
  • Plant growth and development strongly influenced by light quantity and its spectral composition. Young tomato plants were cultivated in growth cabinets under artificial light provided by red and blue light emitting diodes(LEDs) during 12 hours, then plants were exposed to monochromatic ultraviolet, blue, green and red lights as an end-of-day(EOD) treatment during 4 hours to study their effect on plant growth parameters. EOD lighting from various LEDs increased total fresh and dry weights as well as assimilation area compared to those in control. Blue light increased stem height, internode length and stem diameter. Monochromatic UV-A light reduced stem elongation, highly increased stomatal conductance. Compactness and health index of young tomato plants were increased in UV-A and red light treatments.

Synthesis of Super Hydrophobic Disazo Red Dyes using Alkylanilines as Diazo Components (알킬아닐린을 디아조성분으로 활용한 디스아조계 초소수성 적색염료의 합성)

  • Kim, Taekyeong;Ryu, Myeonghwa;Jang, Youngjae
    • Textile Coloration and Finishing
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    • v.27 no.1
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    • pp.27-34
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    • 2015
  • Novel super hydrophobic disazo red dyes were synthesized to improve light fastness of the primary monoazo red dye of previous study on polyolefin fibers such as polypropylene and ultra high molecular weight polyethylene fibers. 4-Alkylanilines were diazotized and then coupled to 2,5-dimethylaniline to produce dye intermediates which were then further used to synthesize final disazo red dyes by diazoization and coupling to ${\beta}$-naphthol. Considering both affinity of the dyes toward both polyolefin fibers and color fastnesses, the decyl-substituted dye was determined as the optimum dye. The decyl-substituted disazo red dye exhibited good dyeability on both polyolefin fibes and almost the same color values as the previous primary monoazo red dye. Light fastness on ultra high molecular weight polyethylene fibers was improved up to rating 3~4 compared to rating 2~3 of the previous primary monoazo red dye.

Microstructural behavior on weld fusion zone of Al-Ti and Ti-Al dissimilar lap welding using single-mode fiber laser

  • Lee, Su-Jin;Kawahito, Yousuke;Kim, Jong-Do;Katayama, Seiji
    • Journal of Advanced Marine Engineering and Technology
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    • v.37 no.7
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    • pp.711-717
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    • 2013
  • Titanium (Ti) metal and its alloys are desirable materials for ship hulls and other structures because of their high strength, light weight and corrosion-resistance. And light weight and corrosion-resistant aluminum (Al) is the ideal metal for shipbuilding. The joining of Ti and Al dissimilar metals is one of the effective measures to reduce weight of the structures or to save rare metals. Ti and Al have great differences in materials properties, and intermetallic compounds such as Ti3Al, TiAl, TiAl3 are easily formed at the contacting surface between Ti and Al. Thus, welding or joining of Ti and Al is considered to be extremely difficult. However, it was clarified that ultra-high speed welding could suppress the formation of intermetallic compounds in the previous study. Results of tensile shear strength increases with an increase in the welding speed, and therefore extremely high welding speed (50m/min in this study) is good to dissimilar weldability for Ti and Al. In this study, therefore, full penetration dissimilar lap welding of Ti (upper) - Al (lower) and Al (upper) - Ti (lower) with single-mode fiber laser was tried at ultra-high welding speed, and the microstructure of the interface zones in the dissimilar Al and Ti weld beads was investigated.

Improving performance of deep-blue OLED by inserting ultra-thin LiF between hole-blocking and electron-transporting layers

  • Sun, J.X.;Zhu, X.L.;Yu, X.M.;Wong, M.;Kwok, H.S.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.956-960
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    • 2006
  • Deep-blue organic light-emitting diodes (OLEDs) with/without ultra-thin LiF layer inserted at the interface between hole-blocking and electron-transporting layers have been fabricated and investigated. The fundamental structures of the OLEDs are ITO/m-MTDATA/NPB/BCP/LiF (with/ without)/ $Alq_3/LiF/Al.Deep$ blue light emission with CIE coordinate of (0.15, 0.11) has been achieved for all devices. Further, by inserting LiF with thickness of 1nm at the interface between BCP and $Alq_3$ layer, the luminous efficiency as well as the power efficiency is much improved compared to that without. The enhancement of electron injection due to insertion of LiF may account for this improvement.

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Microstructural behavior on weld fusion zone of Al-Ti and Ti-Al dissimilar lap welding using single-mode fiber laser

  • Lee, Su-Jin;Katayama, Seiji;Kim, Jong-Do
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.2
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    • pp.133-139
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    • 2014
  • Titanium (Ti) metal and its alloys are desirable materials for ship hulls and other ocean structures because of their high strength, corrosion-resistance and light weight properties. And light weight and corrosion-resistant aluminum (Al) is the ideal metal for shipbuilding. The joining of Ti and Al dissimilar metals is one of the effective methode to reduce weight of the structures. Ti and Al have great differences in materials properties, and intermetallic compounds such as $Ti_3Al$, TiAl, $TiAl_3$ are easily formed at the contacting surface between Ti and Al. Thus, dissimilar welding and joining of Ti and Al are considered to be very difficult. However, it was clarified that ultra-high speed welding could suppress the formation of intermetallic compounds in the previous study. Results of tensile shear strength increases with an increase in the welding speed, and therefore extremely high welding speed (50 m/min) is good to dissimilar weldability for Ti and Al. In this study, therefore, full penetration dissimilar lap welding of Ti (upper) - Al (lower) and Al (upper) - Ti (lower) with single-mode fiber laser was tried at ultra-high welding speed, and the microstructure of the interface zones in the dissimilar Al and Ti weld beads was investigated.