• Title/Summary/Keyword: secondary emission

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Teliospore mucilage of Puccinia miscanthi revealed through the axial imaging of secondary electrons

  • Ki Woo Kim
    • Applied Microscopy
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    • v.51
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    • pp.15.1-15.2
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    • 2021
  • Puccinia miscanthi teliospores were observed on the leaf surface of Miscanthus sinensis using a field emission scanning electron microscope. Details of teliospore mucilage could be visualized through the axial imaging of secondary electrons for a better understanding of pathogen behavior in rust diseases.

The characteristics of AC-PDPs According to binary and ternary gas mixtures of He-Ne-Xe_

  • Lee, H.J.;Son, C.G.;Lee, S.B.;Han, Y.K.;Jeoung, S.H.;You, N.L.;Lim, J.E.;Lee, J.H.;Moon, M.W.;Oh, P.Y.;Jeoung, J.M.;Choi, E.H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1195-1198
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    • 2005
  • The improvement of efficiency is the one of the most important part in AC PDPs . To achieve high efficiency, high VUV emission efficiency and High ion induces secondary electron emission coefficient are needed. We have measured the emission spectra of vacuum ultraviolet rays and ion induced secondary electron emission coefficient of MgO protective layer in surface discharge AC-PDP with binary and ternary gas mixtures. We have investigated electro-optical characteristics of AC-PDPs to optimum gas mixture for high efficient.

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Thermo-Acoustic Emission Behavior of Composites (복합재료의 열-음향방출거동)

  • 김영복;우성충;최낙삼
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2001.10a
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    • pp.111-115
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    • 2001
  • Thermo-acoustic emission (AE) from composite laminates under the repetitive thermal cyclic loads have been quantitatively analyzed in consideration of AE source mechanisms. The repetitive thermal load brought about a large reduction, i.e. an exponential decrease in AE total ringdown counts and AE amplitudes. It was thought that generation of thermo-AE during the first thermal cycle was not caused by crack propagation but by secondary microfracturing due to abrasive contact between crack surfaces.

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Study on Operating Characteristics for NOx Reduction in Ultra Low NOx Burner Combustion Using 80 kW Furnace (80 kW 초 저 NOx 단일 버너 연소로에서 NOx 감소를 위한 운전특성 연구)

  • Chae, Taeyoung
    • Clean Technology
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    • v.26 no.3
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    • pp.211-220
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    • 2020
  • This experimental study investigates the design parameters to achieve ultra low NOx combustion of coal using a 80 kW capacity single-burner furnace. The influence of key design parameters such as SN, overall and burner-zone equivalence ratios, primary/secondary air ratio, overfire air (OFA) ratio were tested for a total of 81 cases. The results showed that weak swirl intensity of the burner leads to higher NOx emission whereas strong swirl intensity accompanies increased CO concentration desipte lower NOx emission. Therefore, finding an appropirate swirl intensity is essential for the burner design. Larger flow rate of secondary air increased NOx emission, whereas smaller flow rate stretches the flame and increased CO emission. The lowest NOx emission of 82 ppm (6% O2) was achieved at the optimal condition of the present burner deisgn. It is expected to furrther lower the NOx emission by introducing splitting the burner secondary air into three or four streams.

Fabrication of high-performance carbon nanotube field emitter using Thermal Chemical Vapor Deposition

  • Yu, Wan-Jun;Cho, You-suk;Park, Gyuseok;Kim, D.J.
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2003.03a
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    • pp.43-43
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    • 2003
  • Carbon nanotubes(CNTs) have many application points, which are field emission devices, composites, hydrogen storage, nanodevices, supercapacitor and secondary battery. The most promising application point is emitter tip mays of field emission devices. Furthermore, it may be also useful as a vacuum device for high frequency and high power. But, there are some obstacles to fabricate carbon nanotube field emission device. One is that CNTs grown by CVD method has weak adhesion with substrate and the other is non-uniform length of them. These problems are very crucial in aging property and reliability of device in the field emission.

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A Study on the Characteristics of Gasoline Engine Performance Equipped with Perforated Throttle Valve (다공 스로틀밸브 장착 가솔린기관의 성능 특성에 관한 연구)

  • Cho, B.O.;Lee, C.S.
    • Journal of ILASS-Korea
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    • v.1 no.2
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    • pp.50-56
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    • 1996
  • In an fuel injection type gasoline engine, atomization of fuel droplet and mixture formation process are very important to understand engine combustion efficiency, and also has influence directly on the decision of engine performance and pollutant emission. In this study, perforated throttle valve instead of solid type throttle valve was developed and equipped to an SPI engine to promote secondary atomization and good droplet-air mixture formation. From the engine performance lest. it was verified that the case of perforated valve kas more advantages in each experimental parameters such as in cylinder gas pressure, mass burnt ratio, fuel consumption rate, and pollutant emission characteristics than that of solid one equipped. No matter what the same perforated valve, there are some distinct results in engine performance characteristics according to the perforate ratio.

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Characteristics of Electron Beam Extraction in Large Area Electron Beam Generator

  • Woo, Sung-Hun;Lee, Hong-Sik
    • KIEE International Transactions on Electrophysics and Applications
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    • v.4C no.1
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    • pp.10-14
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    • 2004
  • A large area electron beam generator has been developed for industrial applications, for example, waste water cleaning, flue gas treatment, and food pasteurization. The operational principle is based on the emission of secondary electrons from the cathode when ions in the plasma contact the cathode, which are accelerated toward the exit window by the gradient of the electric potential. Conventional electron beam generators require an electron beam scanning mechanism because a small area thermal electron emitter is used. The electron beam of the large area electron beam generator does not need to be scanned over target material because the beam area is considerable. We have fabricated a large area electron beam generator with peak energy of 200keV, and a beam diameter of 200mm. The electron beam current has been investigated as a function of accelerating voltage and distance from the extracting window while its radial distribution in front of the extracting window has been also measured.

Influence of sintering temperature of MgO pellet on the electro-optical characteristics of alternating current plasma display panel (AC-PDP)

  • Hong, Sung-Hee;Son, Chang-Gil;Jung, Seok;Kim, Jung-Seok;Paik, Jong-Hoo;Choi, Eun-Ha
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.400-403
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    • 2008
  • We have investigated the electro-optical characteristics of AC-PDP with different MgO protective layers, which have been deposited by electron beam evaporation from various sintered pellets with different temperatures. We have measured the secondary electron emission coefficient ($\gamma$) by using the Gamma Focused Ion Beam ($\gamma$-FIB) system, the static margin, and the address delay time. Also, we have investigated photoluminescence (PL) characteristics for understanding the energy levels of MgO pellets and protective layers.

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