• 제목/요약/키워드: Auger

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A Parametric Study on Secondary Electron Emission from MgO

  • Yoon, Sang-Hoon;Kim, Yong-Seog
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.953-956
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    • 2008
  • Using the theoretical model of Auger electron emission, effects of MgO properties which include band gap energy, escape probability, gas ion, and doping elements on the yield of secondary electron emission were examined. The results indicated that the band gap of MgO must be decreased and escape probability must be enhanced in order to increase the yield of secondary electrons from Xe ions and that may proved to be a critical for achieving high luminance efficacy in ac-PDPs.

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Thickness Measurement of Overlayer Deposited on Single Crystal (금속 단결 정면에 증착된 층의 두께측정)

  • 민항기;변대현
    • Journal of the Korean Vacuum Society
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    • v.1 no.1
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    • pp.73-77
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    • 1992
  • It is not easy to determine the coverage of deposited overlayers on a single crystal. There are several techniques determining the overlayer thickness. We propose, in this study, a new simple method by using Auger spectra only without any sophisticated thickness monitor. An example of iron overlayers on copper single crystals is also showed.

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Dynamics and Bleaching of Ground State in CdSe/ZnS Quantum Dots

  • Kim, J.H.;Kyhm, K.
    • Journal of the Optical Society of Korea
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    • v.10 no.4
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    • pp.184-187
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    • 2006
  • For resonant excitation of the ground state $1s^e-1S^h_{3/2}$, dynamics of 'the electron-hole pair in a CdSe quantum dot was investigated by degenerate pump-probe measurement. At low e-h pair densities, the decay of $1s^e-1S^h_{3/2}$ state is dominated by radiative recombination. As the number of the electron-hole pairs increases, new decay features become significant. Theoretical comparison suggests this is attributed to the bi-molecular and Auger-type scattering.

Development of Chestnut Harvesters for Small Farms (소농을 위한 밤 수확기의 개발)

  • Kang, Whoa-Seug;Guyer, Daniel
    • Journal of Biosystems Engineering
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    • v.33 no.6
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    • pp.384-389
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    • 2008
  • Three prototype chestnut harvesters were constructed and evaluated their chestnut collection ability and field efficiency. Air-lock paddle system successfully picked up all loose material, and pick up efficiency was about 56 kg/h. Power required to operate this system was evaluated to be 8.7 kW with an air flow rate of $32.6\;m^3/min$. A radial blade type blower with 0.41 m impeller diameter was considered to be a minimum size for this system. For the auger system, air was sucked into the cylinder as the hinged flat cover began to be opened by the material pushed by the auger, and the empty burrs flew back to the container through the space between auger flights and collected in the bottom of the container. It was considered to add a device to prevent air from flowing back or to use the back flowing air for separation of burrs and nuts inside the container. The venturi system could not pick up chestnuts, as they only carried part way up to the suction hose. Consideration was given to an idea that the venturi could be used as a cleaning and separation mechanism for containers filled with both empty burrs and good nuts. A minimum vacuum of 129 mm wg was required to pick up chestnuts, and the corresponding inlet air velocity was 19.3 m/s. 104 mm of vacuum, which was about 81 % of that required for nuts, was enough to pick up burrs with nuts inside. Also, empty burrs with higher moisture content recorded the same pressure as for the burrs with nuts.

Technology Trends and Patents Analysis of Auger bit for Deep Cement Mixing (DCM) Method (심층혼합처리 공법용 오거비트의 기술동향 및 특허분석)

  • Min, Kyongnam;Lee, Dongwon;Lee, Jaewon;Kim, Keeseok;Yu, Jihyung;Jung, Chanmuk;Hoang, Truong Xuan;Kwon, Yong Kyu
    • The Journal of Engineering Geology
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    • v.28 no.3
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    • pp.431-441
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    • 2018
  • To set up the future research and development direction for Auger bit, this study analyzed publicized patent trends of Deep Cement Mixing method (DCM) in Korea, USA, Japan, and Europe. DCM method was firstly classified into wing shapes and the number of rods according to the technical scope, and secondly, classified into 8 types according to type of screw and rotation axial. A total of 2,815 patents were searched and 448 validated patents were selected through de-duplication and filtering. As a result of the analysis of the portfolio through the number of patents and growth stages, it was selected as the core technology that auger is deemed to have high growth potential and if there is a patent similar to core technology through a patent barrier analysis, the basic data is suggested to develop the design around and differentiated technologies.

Fabrication and magnetic properties of Co-Zn ferrite thin films prepared by a sol-gel process (Sol-gel 법에 의한 Co-Zn Ferrite 박막의 제호와 자기 특성에 관한 연구)

  • 김철성;안성용;이승화;양계준;류연국
    • Journal of the Korean Magnetics Society
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    • v.11 no.4
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    • pp.168-172
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    • 2001
  • Co-Zn ferrite thin films grown on thermally oxidized silicon wafers were fabricated by a sol-gel method. Magnetic and structural properties of Co-Zn thin films were investigated by using x-ray diffractometer (XRD), atomic force microscopy (AFM), auger electron spectroscopy (AES) and a vibrating sample magnetometer (VSM). Co-Zn ferrite thin films annealed at 400 $^{\circ}C$ presented have only a single phase spinel structure without any preferred crystallite orientation. Their surface roughness of Co-Zn ferrite thin films was shown as less than 3 nm and the grain size was about 40 nm for annealing temperatures over 600 $^{\circ}C$. A moderate saturation magnetization of Co-Zn ferrite thin films for recording media was obtained in this study and there is no significant difference of their magnetic property with those external fields of parallel and perpendicular to planes of the films. The maximum value of the coercivity was obtained as 1,900 Oe for Co-Zn ferrite thin film annealed at 600 $^{\circ}C$.

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EFFICIENT SCREWING : last developments and Korean experience

  • Ines MEYUS;Maurice Bottiau;Myung-Whan Lee;Jong-Bae Park;Yong-Boo Park
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.10a
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    • pp.405-414
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    • 1999
  • The auger and screw piles have known an important evolution during the last decade. Besides the large success of augercast (CFA) piling systems, new systems have been developed combining, to a variable extent, the classical extraction auger with especially designed displacement tools in order to develop screw piles with partial or total lateral soil displacement. These last developments cover the whole range of lateral soil displacement and are more difficult than ever to compare. The authors present the latest evolutions in auger piling systems and compare them with respect to penetration performances, bearing capacities and amount of spoil generated. A special focus is given to a new efficient system: the OMEGA(H) pile in use in Korea since 1997. The results of the Hongcheon site are presented where this R system was applied for a new investment of the Korean National Housing Corporation (KNHC). This first important experience, with the execution of some 1,500 Omega piles with diameter 410 mm, is presented. The piles were installed through loose silty sands down to very dense sands and layers of gravel. The results of full-scale load tests are analysed and show the conformity with requirements of the clients.

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Surface Defects States on a SiO2/Si Observed by REELS

  • Kim, Juhwan;Kim, Beomsik;Park, Soojeong;Park, Chanae;Denny, Yus Rama;Seo, Soonjoo;Chae, Hong Chol;Kang, Hee Jae
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.271-271
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    • 2013
  • The defect states of a Ar-sputtered SiO2 surface on Si (001) were investigated using Auger electron spectroscopy (AES) and reflection electron energy loss spectroscopy (REELS). The REELS spectra at the primary electron energy of 500 eV showedthat three peaks at 2.5, 5.1, and 7.2 eV were found within the band gap after sputtering. These peaks do not appear at the primary electron energies of 1,000 and 1,500 eV, which means that the defect states are located at the extreme surface of a SiO2/Si thin film. According to the calculations, two peaks at 7.2 and 5.1 eV are related to neutral oxygen vacancies. However, the third peak at 2.5 eV has never been previously reported and the theories proposed that this defect state may be due to Si-Si bonding. Our Auger data showed that a peak for Si-Si bonding at 89 eV appears after Ar ion sputtering on the surface of the sample, which is consistent with the theoretical models.

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Surface Phenomena of Deuterized Ethanol Exposed Zircaloy-4 Surfaces

  • Park, Ju-Yun;Jung, Se-Won;Chun, Mi-Sun;Kang, Yong-Cheol
    • Bulletin of the Korean Chemical Society
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    • v.30 no.6
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    • pp.1349-1352
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    • 2009
  • We report the results of the surface chemistry of deuterized ethanol exposed Zircaloy-4 (Zry-4) surfaces with various amount of $C_2D_5$OD exposures at 190 K. This system was examined with Auger electron spectroscopy (AES) and temperature programmed desorption (TPD) techniques. In TPD study, $D_2$ was evolved at two different desorption temperature regions accompanying with broad desorption background. The lower temperature feature at around 520 K showed first-order desorption kinetics. The high temperature desorption peak at around 650 K shifted to lower desorption temperature as the exposure of $C_2D_5$OD increased. The Zr(MNV) Auger peak shifted about 2.5 eV from 147 eV to lower electron energy followed by 300 L of $C_2D_5$OD dosing. This implies metallic zirconium was oxidized by deuterized ethanol adsorption. After stepwise annealing of the oxidized Zry-4 sample up to 843 K, the shifted Zr(MNV) peak was gradually shifted back to metallic zirconium peak position. After the sample was heated to 843 K, the oxygen content near the Zry-4 surface was recovered to clean surface level. The concentration of carbon, however, was not recovered by annealing the sample.

Performance of Organic light-emitting diode by various surface treatments of indium tin oxide (Indium tin oxide 기판의 표면처리에 따른 유기 발광다이오드의 특성)

  • Kim, Sun-Hyuk;Han, Jeong-Whan
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.39 no.9
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    • pp.1-10
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    • 2002
  • We have done various treatments of indium tin oxide (ITO) surface for organic light-emitting diodes (OLEDs), and investigated the surface states by different surface treatments using atomic force microscopy (AFM) and Auger electron spectroscopy (AES). We have fabricated OLEDs deposited by ultra-high vacuum molecular beam deposition system and studied the characteristics of the OLEDs. We have observed the dramatical improvement of the performance of OLEDs fabricated on ITO substrates treated by $O_2$ plasma treatment reduces the carbon comtamination of ITO surfaces and increases the work function of ITO.