• Title/Summary/Keyword: 전도대

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Development of a Bracing System Preventing Falling Down of Movable Scaffoldings in Temporary works (가설공사의 이동식 비계 전도방지 버팀대 개발)

  • Jang, Myung-Houn
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.05a
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    • pp.31-33
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    • 2012
  • Movable scaffolding has been used to work in high places. The scaffolding is economical and convenient to move to other places, but it has the risk of falling down. This paper proposes a fixed bracing system to prevent the falling down of a movable scaffolding, and evaluates its usability by making a small-sized model. Further studies of structural stability, safety, and economical efficiency is necessary to use the system practically.

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The Electrical Insulation Design of 600kJ Conduction Cooled HTS SMES (600kJ 전도냉각 고온초전도 SMES의 전기절연 설계)

  • Choi, Jae-Hyeong;Kwag, Dong-Soon;Cheon, Hyeon-Gweon;Min, Chi-Hyun;Kim, Hae-Jong;Seong, Ki-Chul;Kim, Sang-Hyun
    • Progress in Superconductivity and Cryogenics
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    • v.9 no.3
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    • pp.67-71
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    • 2007
  • The electrical insulation design of 600 kJ conduction cooled high-Tc superconducting magnetic energy storage (SMES) have been studied in this paper. The high voltage is applied to both ends of magnet of high-Tc SMES by quench or energy discharge. Therefore. the insulation design of the high voltage needs for commercialization. stability. reliability and so on. In this study. we analyzed the insulation composition of a high-Tc SMES. and investigated about the insulation characteristics of the materials such as Kapton. AIN. $Al_2O_3$. GFRP and vacuum in cryogenic temperature. Base on these results. the insulation design for 600 kJ conduction cooled high-Tc SMES was performed.

Integrated Interpretation of ERT Data from the Mineralized Zone in Geumpung Mine (금풍광산 광화대에 대한 전기비저항 토모그래피탐사 자료의 복합해석)

  • Jung, Yeon-Ho;Byun, Joong-Moo
    • Geophysics and Geophysical Exploration
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    • v.10 no.4
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    • pp.322-331
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    • 2007
  • In this study, electrical resistivity tomography (ERT) were conducted to find the mineralized zone at the Geumpung mine in Dojeon-ri, Susan-myeon, Jecheon-si, Chungcheongbuk-do. The deviation of the inclined borehole was measured to obtain the exact positions of the electrodes for correcting apparent resistivity values from ERT. Geophysical loggings such as resistivity and natural gamma were conducted to obtain the properties of the material near the borehole. Measurements of the physical properties of the cores, such as porosity, water content, density, susceptibility, resistivity were performed to analyze the correlation between physical properties and resistivity. Grade analysis for core sample was also conducted to identify relationship between grade and resistivity. Rock property analysis shows that the resistivity is more dominated by susceptibility and grade than by porosity and water content in the mineralized zone. The results of ERT are well consistent with geophysical logging data and geologic column. So ERT is powerful method to identify conductive mineralized zone.

Band alignments in Al-doped GaInAsSb/GaSb heterojunctions (Al이 도핑된 GaInAsSb/GaSb의 경계면에서의 밴드정렬)

  • Shim, Kyurhee
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.26 no.6
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    • pp.225-231
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    • 2016
  • The valence band maximum (VBM) and conduction band minimum (CBM) of Al-doped GaInAsSb alloys substrated on GaSb are calculated by using an analytic approximation based on the tight binding method. The relative positions of the VBM and CBM between Al-GaInASSb and GaSb determine band alignement type, valence band offset (VBO) and conductin band offset (CBO) for the heterojunctions. In this study, aluminium doping is assumed to be substituted in the cation site and limited up to 20 % because it can easily oxidize and degrade materials. It is found that the Al-doped alloys exhibit type-II band alignments over the entire composition range and make the band gaps increase, whereas the VBO and CBO decrease. The decreasing rate of VBO is higher than that of CBO, which implies the Al components play a decisive role in controlling electrons at the interface. The Al-dopled GaInAsSb alloy has a direct band gap induced by $E({\Gamma})$ with a considerable distance from the E(L) and E(X), however, $E({\Gamma})$ approaches to E(L) and E(X) in the high Sb concentration (Sb > 0.7-0.8) which might affect the electron mobility and degrade the optical quality.

Insulation test of Mini model for the Development of the conduction cooled HTS SMES (전도냉각형 HTS SMES 개발을 위한 미니모델의 절연성능평가)

  • Choi, Jae-Hyeong;Kwag, Dong-Soon;Cheon, Hyeon-Gweon;Kim, Hae-Jong;Seong, Ki-Chul;Kim, Sang-Hyun
    • Progress in Superconductivity and Cryogenics
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    • v.9 no.1
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    • pp.32-36
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    • 2007
  • The 600 kJ calss high-temperature superconducting(HTS) SMES(superconducting magnetic energy storage) system is being developed by Korean Electrotechnology Research Institute(KERI). The system is operated in cryogenic temperature and high vacuum condition. The SMES magnet was cooled by conduction cooling method using a Gifford-McMahon cycle cryocooler. Thus the electric insulation design at cryogenic temperature and high vacuum is a key and an important element. Because it accomplish compact design that is a big advantage of HTS SMES. This paper describes the electric insulation design, fabrication and experimental results for a mini model of conduction cooled HTS SMES.

Study and Fabrication of Transparent Electrode Film by using Thermal-Roll Imprinted Ag Mesh Pattern and Coated Conductive Polymer (열형-롤 각인으로 형성한 Ag 격자 패턴과 전도성 고분자 코팅을 이용한 투명전극 필름 제작에 관한 연구)

  • Yu, Jong-Su;Jo, Jeong-Dai;Yoon, Seong-Man;Kim, Do-Jin
    • Journal of the Korean Society for Precision Engineering
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    • v.27 no.9
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    • pp.11-15
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    • 2010
  • In this study, to fabricate a low-resistance and high optical transparency electrode film, the following steps were performed: the design and manufacture of electroforming stamp, the fabrication of a thermal roll-imprinted polycarbonate (PC) patterned films, the filled low-resistance Ag paste using doctor blade process on patterned PC films and spin coating by conductive polymers. As a result of PC films imprinted line width of $26.69{\pm}2\;{\mu}m$, channel length of $247.57{\pm}2\;{\mu}m$, and pattern depth of $7.54{\pm}0.2\;{\mu}m$. Ag paste to fill part of the patterned film with conductive polymer coating and then the following parameters were obtained: a sheet resistance of $11.1\;{\Omega}/sq$ optical transparency values at a wavelength of 550 nm was 80.31 %.

Relation between Groundwater Inflow into the Waterway Tunnel and Hydrogeological Characteristics in Hyeonseo-myeon, Cheongsong-gun, Korea (청송군 현서면 일대 도수로터널내 지하수 유입량과 수리지질 특성의 관련성)

  • 박재현;함세영;성익환;이병대;정재열
    • The Journal of Engineering Geology
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    • v.11 no.2
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    • pp.141-152
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    • 2001
  • The waterway tunnel zone (length 1,484m) in the Hyeonseo-myeon area that is a part of Yeongcheon dam waterway tunnel has been studied to characterize the relationship between groundwater inflow into the waterway tunnel and hydrogeologic characteristics. The effects of sandstone thickness in the tunnel section. fracture density, fracture aperture and spacing, fault zone width and hydraulic conductivity on the early inflow (inflow prior to the lining and grouting) are investigated. The relationship between fracture density and hydraulic conductivity is also considered. The result of the study suggests that fault zone width has the greatest effect on groundwater inflow into the tunnel, and sandstone thickness, hydraulic conductivity and fracture density in order shows an influence on the inflow.

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The Significance and Management of Hyporheic Zone (지표수-지하수 혼합대 의의와 관리 필요성)

  • Ko, Dongwoo;Lee, Namjoo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2021.06a
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    • pp.283-283
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    • 2021
  • 혼합대는 지표수와 지하수의 수리적 교환이 일어나는 경계부로써 1) 수문학적 관점에서는 하도와 하상간의 물교환이 이루어지는 공간으로 다양한 물리적·화학적 작용이 발생, 2) 생지화학적인 관점에서는 하상 간극수 흐름에 의한 전이대(ecotone)를 형성하여 용존산소·영양물질·용존유기탄소의 이동뿐만이 아니라 지하수로부터 열에너지·무기염류의 공급을 유도하면서 높은 생지화학적 활동과 변환을 야기하는 산화·환원 반응구역, 3) 생태적인 관점에서는 저서생물과 지하 유기체종을 특징으로 하는 서식지이나 잠재적인 레퓨지움(refugium) 등의 관점에서 해석될 수 있다. 국내 하천환경의 생태학적 지속가능성을 위한 지표수-지하수 혼합대 관리에 대한 중요성이 점차 증대되고 있지만 우리나라는 여전히 지하수의 이용 및 보전과 지하수의 안정적인 수량·수질 확보를 목표로 관리를 추진하고 있다. 따라서, 실질적인 지표수-지하수 혼합대에서 발생하는 다양한 현상의 이해나 관리방안에 관한 연구는 아직 미비한 상황이다. 지표수-지하수 혼합대에 관한 보고서, 논문 등을 종합하여 혼합대의 영향인자를 살펴보면 1) 수리수문 특성에는 수리전도도·하천 수위·하천 유속·하천수 수온, 2) 수질 특성에는 유기오염물질·영양염류, 3) 수생태 특성에는 대형무척추동물 등으로 분류할 수 있다. 지금까지 단일 연구분야의 접근방법으로 다양한 현장측정기법 및 모델링을 통한 혼합대 연구가 수행되고 있지만, 혼합대가 가지는 환경적 중요성에 대한 이해와 인식이 부족하고, 혼합대 내부에서 발생하는 복합적인 프로세스로 인해 전문가들조차 연구에 어려움을 가질 것이다. 지표수-지하수 혼합대의 효율적인 관리를 위해서는 수리수문·수질·수생태 등 다양한 시각에서 접근하여 학제간 융합연구를 통해 기초 데이터를 상호교환하고, 기존의 혼합대 조사에 부족한 부분을 해결할 필요가 있다. 향후 하천 기저유출 및 혼합대 기초자료 구축, 혼합대 흐름 정량화, 하천복원사업에 의한 혼합대 영향 규명 등의 연구를 수행함으로써 혼합대를 체계적으로 관리할 수 있는 기술 방안을 제시할 필요가 있다.

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