• 제목/요약/키워드: Sam-Jo

검색결과 434건 처리시간 0.026초

PHOTOCATALYTIC DEGRADATION OF 2-CHLOROPHENOL USING TiO₂THIN FILMS PREPARED BY CHEMICAL VAPOR DEPOSITION AND ION BEAM SPUTTERING METHOD

  • Jung, Oh-Jin;Kim, Sam-Hyeok;Jo, Ji-Eun;Hwang, Chul-Ho
    • Environmental Engineering Research
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    • 제7권4호
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    • pp.227-237
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    • 2002
  • Chemical vapor deposition (CVD), ion beam sputtering (IBS) and sol-gel method were used to prepare TiO$_2$ thin films for degradation of hazardous organic compounds exemplified by 2-chlorophenol (2-CP). The influence of supporting materials and coating methods on the photocatalytic activity of the TiO$_2$ thin films were also studied. TiO$_2$ thin films were coated onto various supporting materials including steel cloth (SS), copper cloth, quartz glass tube (QGT), and silica gel (SG). Results indicate that SS (37 μm)- TiO$_2$ thin film prepared by IBS method improves the photodegradation of 2-CP. Among all supporting materials studied, SS(37 μm) is found to be the best support.

쇄파의 유동구조 및 쇄파력에 대한 연구 (Research on Wave Kinematics & Wave Loads in Breaking Wave)

  • 이병성;조효제;구자삼;강병윤
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2004년도 학술대회지
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    • pp.96-101
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    • 2004
  • When the wind blows hard, most waves are breaking in sea. Breaking waves occur, exceeding limitation of wave steepness(wave height/wave length=l/7). Because a wave of single angular frequency couldn't generate the breaking phenomena at two dimensional ocean engineering basin, the breaking wave can be generated by the superposition of waves with various angular frequencies. We research how are the particle kinematics in the breaking wave and the magnitude of the breaking wave exciting force. We compare the force in a regular wave which has same specifications(wave height, period and length) as the breaking wave. Also the experimental results of wave exciting force and particle velocity are investigated by comparison on the analytic results using the potential theory.

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Tetracycline-incorporated Silk Fibroin Films

  • Kim, Jong-Ho;Shin, Bong-Seob;Jeon, Jong-Young;Kweon, Hae-Yong;Jo, You-Young;Lee, Heui-Sam;Lee, Kwang-Gill
    • International Journal of Industrial Entomology and Biomaterials
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    • 제25권1호
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    • pp.129-132
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    • 2012
  • Silk fibroin films incorporated with tetracycline was prepared and characterized by Fourier-transform infrared spectrometer and differential scanning calorimeter and examined antibacterial effect. The conformation of silk fibroin was changed from random coil to $\hat{a}$ sheet structure with incorporation of tetracycline. Antibacterial activity of the materials was evaluated against Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus epidermis, and Staphylococcus aures) using agar plate method showing clear inhibition zone around tetracycline silk film. It is concluded that tetracycline-incorporated SF films are highly effective against bacteria.

틸팅 차량용 차체의 하이브리드 복합재 접합체결부의 내구성 평가 (Fatigue Assessment of Hybrid Composite Joint for the Tilting Car Body)

  • 정달우;최낙삼;김정석;서승일;조세현
    • 한국신뢰성학회:학술대회논문집
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    • 한국신뢰성학회 2006년도 학술발표대회 논문집
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    • pp.357-361
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    • 2006
  • Fatigue fracture behavior of a hybrid joint part with bolting was evaluated in comparison to the case of static fracture. Hybrid joint part specimens for bending test were made with layers of CFRP and aluminum honeycomb. Characteristic fracture behaviors of those specimens were obviously different under static and cyclic loads. Static bending load showed the shear deformation at the honeycomb core, whereas cyclic bending load caused the delamination between CFRP skin layers and honeycomb core. Experimental results obtained by static and fatigue tests were considered in modifications of design parameters of the hybrid joint.

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교번류에 대한 Geotextile의 여과특생과 여과기준 (Filter Characteristics and Filter Criteria of Geotextiles Under Alternating Flow Conditions)

  • 조삼덕;백승철;홍성완
    • 한국지반공학회지:지반
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    • 제6권2호
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    • pp.21-34
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    • 1990
  • 국내에서 여과용도로 폭넓게 사용되고 있는 Geotextile인 단섬유부직포를 대상으로 교번류상태에서의 흙/Geoteztile 시스템에 대한 실내 여과특성실험을 수행하였다. 실험을 통하여 교번주기, 교번동수경사, 수직하중 및 지반흙의 입도와 밀도등 여러 영향인자들이 흙/Geotextile시스템의 여과구조,수직투수성 및 흙 보유성에 미치는 효과를 규명하였으며, 국내생산 단섬유부직포에 대한 교번류 작용시의 보유성 기준과 투수성 기준을 제시하였다.

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임계 전류모드에서의 다상 교호 승압컨버터의 특성 연구 (A Study on the Characteristics of Multi-Phase Interleaved Boost Converter Operating in Boundary Conduction Mode)

  • 이재삼;배철수;손호인;문석조;허동영
    • 전력전자학회논문지
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    • 제13권4호
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    • pp.257-262
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    • 2008
  • 본 논문에서는 임계 인덕터 전류모드로 동작하는 다상 교호 승압컨버터의 평균 상태방정식을 유도하고, 정상상태 해석 및 소 신호 제어특성을 고찰한다. 또한, 유도된 수식 이론을 근거로, 800W급 2상 교호 승압컨버터를 제작하고, 60인치용 PDP 파워모듈의 PFC 블록에 적용함으로서, 제안된 방식의 실효성을 검증한다.

얼굴의 geometry 특징을 이용한 다중해상도 템플릿 매칭 얼굴 특징 추출법

  • 윤성욱;김재민;조성원;최경삼;백성욱
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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    • pp.1002-1005
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    • 2003
  • This paper presents a new template matching method for finding facial feature points. Instead of matching each template to its corresponding feature point separately the present method matches a set of element templates simultaneously. The set of templates can be placed on the space predefined by the geometrical characteristics of human faces. As a result, the search area for template matching is very small compared with a conventional method. This makes the presented method very robust and accurate. Experiment results show that the presented method results in good performance In various illuminance environments and poses.

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Measurement of Zero Dispersion Wavelength in an Optical Fiber Using the Oscillatory Behavior of Four-Wave Mixing Efficiency

  • Kim, Dong-Hwan;Kim, Sang-Hyuck;Jo, Jae-Cheol;Choi, Sang-Sam
    • Journal of the Optical Society of Korea
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    • 제5권1호
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    • pp.20-24
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    • 2001
  • Non-destructive measurement of zero-dispersion wavelength variation in a dispersion shifted fiber by four-wave mixing technique is carried out. The oscillatory behavior of the four-wave mixing efficiency is utilized for the measurement of the linear dispersion slope and zero-dispersion wavelength. A simple formula useful for engineering estimation of the characteristics of fiber four-wave mixing efficiency is presented.

AFM을 이용한 미세 패턴 가공 시 접촉 하중에 따른 선폭 변화에 대한 연구 (Investigation on the Effect of Contact Load on Fine Pattern Fabrication by AFM)

  • 조상범;김대은
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 추계학술대회 논문집
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    • pp.502-505
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    • 2005
  • To overcome some of the limitations in the conventional photolithography technique, MC-SPL which has advantages such as flexibility and high speed was developed in the past. To make a fine pattern using MC-SPL, there are many variables to control, for example, applied load, scribing speed, chemical etching condition, and etc. In this work, the effect of contact load on the width of the pattern was investigated. The load not only influences the width of the pattern but it also affects the wear of the probe tip. It was found that it is beneficial to load the tip in two stages. Futhermore, the experimental results showed that the pattern width was more sensitive to the initial contact force.

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