• Title/Summary/Keyword: Connected surface

검색결과 625건 처리시간 0.052초

갱도(坑道)를 이용(利用)한 인공분극법(人工分極法) 모형(模型) 연구(硏究) (Scaled Model Study on the Underground Mise-à-la-masse Method)

  • 서백수;송영수
    • 산업기술연구
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    • 제5권
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    • pp.81-89
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    • 1985
  • A Mise-$\grave{a}$-la-masse method is to use a subsurface conductive mass itself as one current electrode of a pair by connecting it directly to one pole of a voltage source, the second current electrode being placed on the ground surface at a great distance and connected to the other pole. This paper is to study the modified Mise-$\grave{a}$-la-masse method using a water tank, that is, the second current electrode is placed on the underground level instead of being placed at a great distance, to find the geometry and the continuity of ore bodies.

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Si웨이퍼의 이방성 식각 특성 및 Si carrier를 이용한 플립칩 솔더 범프제작에 관한 연구 (The characterization of anisotropic Si wafer etching and fabrication of flip chip solder bump using transferred Si carrier)

  • 문원철;김대곤;서창재;신영의;정승부
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2006년도 춘계 학술대회 개요집
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    • pp.16-17
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    • 2006
  • We researched by the characteristic of a anisotropic etching of Si wafer and the Si career concerning the flip chip solder bump. Connectors and Anisotropic Conductive Film (ACF) method was already applied to board-to-board interconnection. In place of them, we have focused on board to board interconnection with solder bump by Si carrier, which has been used as Flip chip bonding technology. A major advantage of this technology is that the Flexible Printed Circuit (FPC) is connected in the same solder reflow process with other surface mount devices. This technology can be applied to semiconductors and electronic devices for higher functionality, integration and reliability.

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백금족 전력 계면에서 전기화학적 Impulse 발진 (Electrochemical Impulse Oscillations at the Platinum Group Electrode Interfaces)

  • 전장호;손광철;라극환
    • 전자공학회논문지A
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    • 제32A권3호
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    • pp.143-151
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    • 1995
  • The electrochemical impulse oscillations of the cathodic currents at the platinum group (Pt, Pd) electrode/(0.05M KHC$_{8}H_{4}O_{4}$) buffer solution interfaces have been studied using voltammetric, chronoamperometric, and electrochemical impedance methods. The periodic impulses of the cathodic currents are the activation controlled currents due to the hydrogen evolution reaction, and depend on the fractional surface coverage of the adsorbed hydrogen intermediate and potential. The oscillatory mechanism of the cathodic current impulses is connected with the unstable steady state of negative differential resistance. The widths and periods of the cathodic current impulses are 4ms or 5ms and 152.5ms or 305ms, respectively. The H$^{+}$ discharge reaction step is 38 or 61 times faster thatn the recombination reaction steps and the H$^{+}$ mass transport processes. The atom-atom recombination reaction step is twice faster thatn the atom-ion recombination reaction step. The two kinds of active sites corresponding to the atom-atom and atom-ion recombination reaction steps exist on the platinum group electrode surfaces.

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Yarned CNT Fiber 저항체의 전기적 특성 (Electrical Properties of Yarned Carbon Nanotube Fiber Resistors)

  • 임영택;이선우
    • 한국전기전자재료학회논문지
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    • 제30권1호
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    • pp.59-62
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    • 2017
  • CNT (carbon nanotube) resistors with low resistance and negative TCR (temperature coefficient of resistance) were fabricated with yarned CNT (carbon nanotube) fibers. The CNT fibers were prepared by yarning CNTs grown on the silicone substrate by CVD (chemical vapor deposition) method. The CNT resistors were fabricated by winding CNT fibers on the surface of ceramic rod. Both metal terminals were connected with the CNT fiber wound on the ceramic rod. We measured electrical resistance and thermal stability with the number of CNT fibers wound. The CNT resistor system shows linearly decreased resistance with the number of CNTs wound on the ceramic rod and saturated at 20 strands. The CNT resistor system has negative TCR between $-1,000{\sim}-2,000ppm/^{\circ}C$ and stable frequency properties under 100 kHz.

CSP용 시소타입 로딩장치의 개발 (Development of Seesaw-Type CSP Solder Ball Loader)

  • 이준환;구흥모;우영환;이종원;신영의
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 춘계학술대회논문집A
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    • pp.873-878
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    • 2000
  • Semiconductor packaging technology is changed rapidly according to the trends of the micro miniaturization of multimedia and information equipment. For I/O limitation and fine pitch limitation, DIP and SOP/QFP are replaced by BGA/CSP. This is one of the surface mount technology(SMT). Solder ball is bumped n the die pad and connected onto mounting board. In ball bump formation, vacuum suction type ball alignment process is widely used, However this type has some problems such as ionization, static electricity and difficulty of fifo(first-input first-out) of solder balls. Seesaw type is reducing these problems and has a structural simplicity and economic efficiency. Ball cartridge velocity and ball aligned plate angle are Important variables to improve the ball alignment Process. In this paper, seesaw-type CSP solder ball loader is developed and the optimal velocity and plate angle are proposed.

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열교환장치의 냉각수 계통에서 세라믹 볼의 파울링 저감효과 (Effect of Fouling Mitigation for Ceramic Ball in Cooling Water System of Heat Exchanger)

  • 서상호;성순경
    • 대한기계학회논문집B
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    • 제31권4호
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    • pp.330-334
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    • 2007
  • The objective of this study was to investigate the effecs of fouling mitigation for ceramic ball in cooling water system experimentally. The devices filled with ceramic balls were connected to the bypass line of the heat exchanging system. Cooling water in the heat exchanging system was artificial water. To visualize the formation of fouling on the heat transfer surface a number of images were obtained using a CCD camera with real-time microscopy. Fouling resistances and overall heat transfer coefficients were measured in order to analyze fouling mitigation effects. We found that the ceramic ball devices for artificial water reduced the formation of fouling compared to the no-mitigation devices.

Metal-assisted grown Si films and semiconducting nanowires for solar cells

  • 김준동
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2010년도 춘계학술발표대회
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    • pp.13-13
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    • 2010
  • The solar energy conversion will take 10 % global energy need by 2033. A thin film type solar cell has been considered as one of the promising candidates for a large area applicable solar cell fabrication at a low cost. The metal-assisted growth of microcrystalline Si (mc-Si) films has been reported for a quality Si film synthesis at a low temperature. It discusses the spontaneous growth of a Si film above a metal-layer for a thin film solar cell. Quite recently, a substantial demand of nanomaterials has been addressed for cost-effective solar cells. The nanostructure provides a large photoactive surface at a fixed volume, which is an advantage in the effective use of solar power. But the promising of nanostructure active solar cell has not been much fulfilled due mainly to the difficulty in architecture of nanostructures. We present here the Si nanowire (SiNW)-embedded Schottky solar cell. Multiple SiNWs were connected to two different metals to form a Schottky or an ohmic contact according to the metal work function values. It discusses the scheme of rectifying contact between metals and SiNWs and the SiNW-embedded Schottky solar cell performances.

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패션감성과 의복조형성의 관계 연구 (A Study of the relationship between Fashion Sensibility and Formative Properties in Clothing)

  • 이경희;김유진
    • 한국의류학회지
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    • 제25권5호
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    • pp.845-855
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    • 2001
  • Now the most important thing in fashion industry is find out the fashion sensibility and preference of customers exactly. Thus it is needed that fashion sensibility is connected with formative properties in clothing. The purpose of this study is to clarify the relationship between the fashion sensibility and the formative properties in clothing. 91 kinds of costume samples have been selected from photographs in fashion magazines under color combination, inside form, texture, pattern type in clothing. I have measured fashion sensibility by using Semantic Differential method. The obtained data were analyzed by GLM, discriminant analysis. The results of analysis are as follow; 1. The discriminative images were significant difference in formative properties - color combination was related to attractiveness, inner form to decorativeness, pattern to harmony and texture to surface of soft and hard in clothing. 2. fashion sensibility was significant relationship with formative properties especially inner form in clothing. And the trimming was identified as gorgeous and feminine. 3. Preference, Buying needs, Riches and Pleasant were significant relationship with formative properties in clothing especially color combination and texture.

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Morphological Variation of Enterobacter sp. BL-2 in Acetate-mediated pH Environment for Excretive Production of Cationic Microbial Polyglucosamine Biopolymer

  • Son, Mi-Kyung;Hong, Soo-Jung;SaGong, Kuk-Hwa;Lee, Yong-Hyun
    • Journal of Microbiology and Biotechnology
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    • 제18권1호
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    • pp.104-106
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    • 2008
  • Enterobacter sp. BL-2 excretively produced a unique cationic polyglucosamine biopolymer PGB-1 comprised of more than 95% D-glucosamine in an acetate-mediated culture condition. The excretion of the biopolymer PGB-1 was closely associated with the cellular morphology of Enterobacter sp. BL-2, a feature highly dependable on the pH of the medium. The initially formed uneven and irregular surface cells were aggregated into the cell-biopolymer network structure connected by the adhesion modules of the cell-bound biopolymer. The excretive production of the biopolymer PGB-1 coincided with the disruption of the cell-biopolymer network, most actively at the medium pH of 8.0.

장 족무지 굴곡건의 감입시 발생되는 비정복 종골 골절 -1예 보고- (Irreducible Fracture of Calcaneus due to Flexor Hallucis Longus Tendon Interposition -A Case Report-)

  • 김광희;박홍기
    • 대한족부족관절학회지
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    • 제10권2호
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    • pp.271-273
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    • 2006
  • In closed calcaneus fractures, the occurrence of FHL interposition in subtalar joint is relatively rare and difficult to diagnosis preoperatively. But careful physical examination and significant radiologic findings could be useful tools to diagnosis preoperatively. This findings is shearing off a superior medial fragment made up of the sustentaculum talus connected to a significant portion of the medial wall and medial aticular surface of the posterior facet.

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