• Title/Summary/Keyword: Secondary electron yield

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The study on MgO formation for AC PDP prepared by R.F. reactive magnetron Sputtering (반응성 R.F. 스퍼트링에 의한 AC PDP 용 MgO형성에 관한 연구)

  • Ha, H.J.;Lee, W.G.;Nam, S.O.;Ha, S.C.;Cho, J.S.;Park, C.H.
    • Proceedings of the KIEE Conference
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    • 1996.07c
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    • pp.1576-1578
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    • 1996
  • MgO protection layer in ac PDP prevents the dielectric layer from sputtering of ion in discharge plasma in addition to the contribution to the memory function and also have the additional important roll in lowering the firing Voltage due to a large secondary electron emission yield(${\gamma}$). The methode of Sputtering are easy to apply on mass production and to enlarge the size of the panel and are known to have the superior Adhesion and Uniformity of thin film. MgO protection layer of $1000{\AA}$ on dielectric layer by Reactive R.F magnetron sputtering is formed. Discharge characteristics have done with the formation of protection layer.

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A Study on the Mechanical Properties of Duplex Stainless Steel Weldment According to Mo Contents

  • Bae, Seong Han;Lim, Hee Dae;Jung, Won Jung;Gil, Woong;Jeon, Eon Chan;Lee, Sung Geun;Lee, Hyo Jong;Kim, In Soo;Lee, Hae Woo
    • Korean Journal of Metals and Materials
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    • v.50 no.9
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    • pp.645-651
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    • 2012
  • This study investigated changes in phase fraction caused by the addition of Mo, as well as the subsequent behaviour of N and its effect on the mechanical properties of welded 24Cr-N duplex stainless steel weld metals. Filler metal was produced by fixing the contents of Cr, Ni, N, and Mn while adjusting the Mo content to 1.4, 2.5, 3.5 wt%. The delta ferrite fraction increased as the Mo content increased. In contrast, the ${\gamma}$ fraction decreased and changed from a round to an acicular shape. Secondary austenite (${\gamma}^{\prime}$) was observed in all specimens in a refined form, but it decreased as the Mo content increased to the extent that it was nearly impossible to find any secondary austenite at 3.5 wt% Mo. Both tensile and yield strengths increased with the addition of Mo. In contrast, the highest value of ductility was observed at 1.41 wt% Mo. At all temperatures, impact energy absorption showed the lowest value at 3.5 wt% Mo, at which the amount of ${\delta}$-ferrite was greatest. There was no significant temperature dependence of the impact energy absorption values for any of the specimens. As the fraction of ${\gamma}$ phase decreased, the amount of N stacked in the ${\gamma}$ phase increased. Consequently, the stacking fault energy decreased, while the hardness of ${\gamma}$ increased.

Microstructural and Mechanical Characteristics of Al-Si-Cu Die Casting Alloy for Engine Mount Bracket (엔진 마운트 브라켓용 다이캐스팅 Al-Si-Cu 합금의 미세조직과 기계적 특성)

  • Chyun, In-Bum;Hong, Seung-Pyo;Kim, Chung-Seok
    • Journal of the Korean Society for Heat Treatment
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    • v.27 no.6
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    • pp.281-287
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    • 2014
  • Microstructural and mechanical characteristics of Al-6Si-2Cu alloy for engine mount bracket prepared by gravity casting (as-cast) and die-casting (as-diecast) process have been investigated. For the microstructural characterization, the inductively coupled plasma mass spectrometry (ICP-MS), optical microscope (OM), scanning electron microscope (SEM) and electron probe microanalysis (EPMA) analyses are conducted. For the intermetallic phases, the X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) are also conducted with quantitative and qualitative analysis. Micro Vickers hardness and static tensile test are achieved in order to measure mechanical properties of alloys. Secondary dendrite arm spacing (SDAS) of as-cast and as-diecast show 37um and 18um, respectively. A large amount of coarsen eutectic Si, $Al_2Cu$ intermetallic phase and Fe-rich phases are identified in the Al-6Si-2Cu alloy. Mechanical properties of gravity casting alloy are much higher than those of die-casting alloy. Especially, yield strength and elongation of gravity casting alloy show 2 times higher than die-casting alloy. After shot peening, shot peening refined the surface grains and Si particles of the alloys by plastic deformation. The surface hardness value shows that shot peening alloy has higher value than unpeening alloy.

Effect of temperature on photosynthetic capacity and influence of harvesting time on quality of Salvia miltiorrhiza Bunge (온도에 따른 단삼의 광합성 특성 및 수확시기가 품질에 미치는 영향)

  • Seo, Young-Jin;Kim, Jong-Su;Kim, Sun-Hwa;Kim, Mi-Yeon;Jeong, Yong-Jin;Seong, Gi-Un;Chung, Shin-Kyo
    • Food Science and Preservation
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    • v.22 no.6
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    • pp.804-810
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    • 2015
  • Salvia miltiorrhiza has been used for treating heart and liver disease. In the present study, the influences of temperature on photosynthetical capacity of S. miltiorrhiza under controlled cultivation environment using growth chamber were investigated because of providing information about growth and secondary metabolite synthesis. And effect of harvesting time on growth properties and constituents such as salvianolic acid B, cryptotanshinone, tanshinone I, tanshinone IIA were evaluated. Maximum photosynthesis rate ($5.102{\mu}mol\;CO2/m2/s$) and net apparent quantum yield ($0.147{\mu}mol\;CO2/m2/s$), stomatal conductance (0.035 mmol/m2/s) and water use efficiency ($7.108{\mu}mol\;CO2/mmol\;H2O$) was highest at $20^{\circ}C$. Results of chlorophyll fluorescence showed that elevated temperature had contributed to reduce a quantum yield and electron flux in photosystem. This result demonstrated that favorable temperature condition was determined at $20^{\circ}C$. Contents of salvianolic acid B, cryptotanshinone, tanshinone I and tanshinone IIA was highest in root sample harvested at 20 March, whereas growth and yield of S. miltiorrhiza had no significant differences with harvesting time. Therefore, this study shows that temperature play an important role in photosynthetic activity and harvesting time have influence upon accumulation of constituents in root of S. miltiorrhiza.

Proteomic Analysis and Growth Responses of Rice with Different Levels of Titanium Dioxide and UV-B (이산화티탄과 UV-B 수준에 따른 벼 생육과 프로테옴 해석)

  • Hong, Seung-Chang;Shin, Pyung-Gyun;Chang, An-Cheol;Lee, Ki-Sang;Lee, Chul-Won;Woo, Sun-Hee
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.52 no.1
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    • pp.69-80
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    • 2007
  • Among the photoactive semiconductors such as $TiO_2,\;ZnO,\;Fe_2O_3,\;WO_3,\;and\;CdSe,\;TiO_2$ is the most widely used as photocatalyst in different media, because of its lack of toxicity and stability. In this study, the effects of titanium dioxide were investigated to obtain the information of physiological change in rice plant. Light-adapted Chlorophyll flourescence index decreased and relative electron transport rate of rice leaves was activated by titanium dioxide under $2,400\;{\mu}mol\;m^{-2}\;s^{-1}$ PAR (Photosynthetic active radiation). Relative electron transport rate of rice leaf treated with titanium dioxide 10 ppm was high in order of $2,400\;{\mu}mol\;m^{-2}\;s^{-1}\;PAR,\;2,200\;{\mu}mol\;m^{-2}\;s^{-1}\;PAR,\;450\;{\mu}mol\;m^{-2}\;s^{-1}\;PAR$ and titanium dioxide 10 ppm (45.1%), control (32.4%), diuron 10 ppm (15.3%) under $2,400\;{\mu}mol\;m^{-2}\;s^{-1}\;PAR$. Titanium dioxide increased photosynthesis of the rice leaf under $13.6\;KJ\;m^{-2}\;day^{-1}$ UV-B only. With titanium dioxide 20 ppm, reduced UV-B ($0.15\;KJ\;m^{-2}\;day^{-1}$) intensity changed the induction of proteins and twenty-five proteins were identified. Among them, seventy proteins were up-regulated, four proteins were down-regulated and four proteins were newly synthesized. Function of these proteins was related to photosynthesis (52%), carbohydrate metabolism (4%), stress/defense (8%), secondary metabolism (4%), energy/electron transport (4%), and miscellaneous (28%).