• Title/Summary/Keyword: Counter-method

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A Study on Measurement for Earth Resistance of Steel Structure (철탑접지저항 측정에 관한 연구)

  • 박석탁;김시영
    • 전기의세계
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    • v.22 no.6
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    • pp.33-51
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    • 1973
  • To lower the earth resistance shall be one of the most effective method for the prevention of lightening damage on power transmission line. In this report, in order to investigate various characteristic necessary to lowering the earth resistance, the following experiments have been made at 154KV U1San-PoHang T/L, 154KV YoSu-SoonChun T/L and so on. 1. Measurement of Earth specific resistance, 2. Efficiency of Earthing of concrete foundation for steel structure., 3. Efficiency of Earthing with counter poise., 4. Compound impulse test with foundation of steel structure and counter poise. With the above investigate a guidance have been prepared for the effective work-performance of steel structure.

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Counter-Current Gas-Liquid Two-Phase Flow in Narrow Rectangular Channels with Offset Strip Fins (휜이 있는 협소 사각 유로에서 대향류 기/액 2상 유동)

  • Sohn, B.H.;Kim, B.J.;Jeong, S.
    • Proceedings of the KSME Conference
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    • 2001.06e
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    • pp.229-234
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    • 2001
  • An adiabatic counter-current vertical two-phase flow of air and water in narrow rectangular channels with offset strip fm was investigated experimentally. Tests were systematically performed with downward liquid superficial velocities and upward gas velocities covering 0 to 0.06 m/s and 0 to 2.5 m/s ranges, respectively. Two-phase flow regimes were classified by examining the video images of flow patterns in transparent test sections of 760 mm long and 100 mm wide channel with gaps of 3.0 and 5.0 mm. The channel average void fraction was measured by the quick-closing valve method. Unlike the flow regimes in the channels without fin, where bubbly, slug, chum, and annular flow were identified, only bubbly and chum flow regimes were found for the channels with offset strip fin. However the existence of fin in the channels showed negligible effects on the void fraction. Instead counter-current flow limitations were found to happen at lower air superficial velocity once offset strip fin was introduced in narrow rectangular channels.

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Development of form rolling technology for high precision worm using the rack dies of counter flow type (Counter Flow 방식의 랙 다이를 이용한 고정밀도 Worm 전조기술 개발)

  • 고대철;박준모;김병민
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1861-1864
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    • 2003
  • The objective of this study is to suggest the form rolling technology to produce high precision worm. Rack dies and roll dies are usually used to roll parts with worm teeth. The form roiling processes of worm shaft used as automotive part using the rack dies of counter flow type and the roll dies are considered and simulated by the commercial finite element code, DEFORM-3D. It is also important to determine the initial blank diameter in form rolling because it affects the quality of thread. The calculation method of the initial blank diameter in form rolling is suggested and it is verified by FE-simulation. The experiments using rack dies and roll dies are performed under the same conditions as those of simulation. The results of simulation and experiment in this study show that the from rolling process of worm shaft using the rack dies is decidedly superior to that using rolling dies from the aspect of the surface roughness and the profile of worm.

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Development of Gas Production Measurement System by Bubble Counting during Fermentation (기포계수식 발효가스 발생량 계측시스템의 개발)

  • Lee, Young-Jin;Chun, Jae-Kun
    • Korean Journal of Food Science and Technology
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    • v.26 no.3
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    • pp.195-198
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    • 1994
  • A bubble counter was designed and fabricated for the measurement of gas production rate on the basis of number of bubbles produced from yeast fermentor. The sensor was consisted of bubble forming device and electronic signal processing circuitry. The bubble forming device was built with bubble collector and liquid cell to form uniform size of bubble. Bubbles were counted by pulses formed by photo-interrupter circuitry having 8-bit binary latch counter. The gas production rate curves on the basis of bubble counted showed a good agreement to that of growth curves obtained by the optical measurement method. The sensor was succesfully applied to monitoring of the nutrient utilization test with glucose and galactose media.

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Distance measurement using pulsed eye-safe laser (펄스형 eye-safe 레이저를 이용한 거리측정)

  • 유병헌;조성학;장원석;김재구;황경현;이동주
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.106-109
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    • 2004
  • In this project, we have developed the eye-safe LRF system of 1.54 ${\mu}{\textrm}{m}$ wavelength using OPO. The maximum measured distance was 3.7km in outdoor experiment. We used Nd:YAG (1064nm) as a laser medium. It was applied BBO to construct the system. We also developed a time-counter for the range finder using a method of TOF (time of flight). The counter-clock used at the time counter was 320MHz making resolution within $\pm$1m. Start and stop signals were detected by two channel systems using PIN and APD. The LRF's repetition rate was 4 times per minute. The energy was measured to be over 9mJ. And, pulse-duration was 23ns. Resolution was $\pm$2m at the distance measurement using a target.

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Synthesis and Characterization of Graphene Counter Electrode By Electrophoretic Deposition for Dye-Sensitized Solar Cells

  • Choe, Yun-Su;Gong, Jae-Seok;Choe, Hyeon-Gwang;Jeon, Min-Hyeon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.160-160
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    • 2013
  • Dye-sensitized solar cells (DSSCs) have attracted much attention because of their moderate light-to-electricity conversion efficiency, easy fabrication, and low cost. At present, platinum (Pt) is used as a counter electrode in DSSCs. However, it is found that Pt dissolves in iodide electrolyte solutions and creates chemical compound such as PtI4 and H2PtI6. Carbon based materials are one of candidates for a counter electrode of DSSCs. We prepare two types of graphite oxides by different chemical treatments; original graphite oxide, hydrazine treated graphite oxide. Each graphite oxide and magnesium nitrate dispersed in deionized water are prepared as solutions for electrophoretic deposition (EPD). Each graphite oxide electrode is deposited on fluorine-doped tin oxide (FTO) substrate by EPD method. Structural and electrochemical properties of each electrode are investigated by field-emission scanning electron microscopy and electrochemical impedance spectroscopy, respectively.

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A study on the mine artillery striking method using agent based modeling & simulation (에이전트 기반모의를 통한 갱도포병 타격방안 연구)

  • Kim, Se-Yong
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2008.10a
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    • pp.359-363
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    • 2008
  • In recent warfare, importance of counter-fire is increased. New weapon system and counter-fire have critical impact on defeating of the enemy. At an initial battle counter-fire, we need to study about striking plan against the enemy mine artillery. In this paper, we studied, using MANA(agent based model), how much cannon's hit probability and UAV-based target acquisition have influence on striking the mine artillery. We constructed MANA model based on the characteristics of a regional database of Korean peninsula. If we develop detail database of the ROK Army, the proposed MANA model can be used as a war-game model for the regimental level of the Army.

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COMBINED FORWARD-BACKWARD EXTRUSION WITH REVERSE RAM MOTION -APPLICATION TO FORMING OF GEAR-

  • Otsu M.;Hayashida D.;Osakada K.;Hanami S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.10b
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    • pp.158-161
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    • 2003
  • Extrusion of forward-gear and backward-rod by combined extrusion with controlling the extrusion velocity using a counter tool is studied. In the combined forward-backward extrusion with controlling extrusion velocity, only parts with short gear can be formed. To obtain longer gear parts, extrusion with reverse ram motion is carried out after the combined forward-backward extrusion process. In this method, combined forward-backward extrusion is carried out until excessive extrusion length is attained and then, the motion of the punch is stopped and the counter tool is moved in the inverse direction and returned to the position for obtaining the desired extrusion length. The experiment is carried out by using lead for billets as a model material. With reverse ram motion, longer gear teeth without under-filling defect can be formed than that by only combined extrusion with controlling extrusion velocity.

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APPLICATION OF WHOLE BODY COUNTER TO NEUTRON DOSE ASSESSMENT IN CRITICALITY ACCIDENTS

  • Kurihara, O.;Tsujimura, N.;Takasaki, K.;Momose, T.;Maruo, Y.
    • Journal of Radiation Protection and Research
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    • v.26 no.3
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    • pp.249-253
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    • 2001
  • Neutron dose assessment in criticality accidents using Whole Body Counter (WBC) was proved to be an effective method as rapid neutron dose estimation at the JCO criticality accident in Tokai-mura. The 1.36MeV gamma-ray of $^{24}Na$ in a body can be detected easily by a germanium detector. The Minimum Detectable Activity (MDA) of $^{24}Na$ is approximately 50Bq for 10miniute measurement by the germanium-type whole body counter at JNC Tokai Works. Neutron energy spectra at the typical shielding conditions in criticality accidents were calculated and the conversion factor, whole body activity-to-organ mass weighted neutron absorbed dose, corresponding to each condition were determined. The conversion factor for uncollied fission spectrum is 7.7 $[(Bq^{24}Na/g^{23}Na)/mGy]$.

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Fast Protein Staining in Sodium Dodecyl Sulfate Polyacrylamide Gel using Counter ion-Dyes, Coomassie Brilliant Blue R-250 and Neutral Red

  • Choi, Jung-Kap;Yoo, Gyurng-Soo
    • Archives of Pharmacal Research
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    • v.25 no.5
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    • pp.704-708
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    • 2002
  • A fast and sensitive protein staining method in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) using both an acidic dye, Coomassie Brilliant Blue R-250 (CBBR) and a basic dye, Neutral Red (NR) is described. It is based on a counter ion-dye staining technique that employs oppositely charged two dyes to form an ion-pair complex. The selective binding of the free dye molecules to proteins in an acidic solution enhances the staining effect of CBBR on protein bands, and also reduces gel background. It is a rapid staining procedure, involving fixing and staining steps with short destaining that are completed in about 1 h. As the result, it showed two to fourfold increase in sensitivity comparing with CBBR staining. The stained protein bands can be visualized at the same time of staining.