• 제목/요약/키워드: light elements

검색결과 838건 처리시간 0.035초

무인 이동체를 이용한 폐광산 갱도 및 수몰 갱도의 3차원 형상화 위한 적용성 평가 (Evaluation of Applicability for 3D Scanning of Abandoned or Flooded Mine Sites Using Unmanned Mobility)

  • 김수로;박관인;김상욱;백승한
    • 터널과지하공간
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    • 제34권1호
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    • pp.1-14
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    • 2024
  • 폐광산의 갱도 입구를 통해 고속 라이다(Light Detection And Ranging, LiDAR) 장비가 탑재된 무인이동체를 투입하여 폐광의 갱도를 형상화하기 위한 기술이 제안되었다. 직경이 1.5 m 이상인 좁은 갱도에 바닥이 슬러지 형태로 미끄럽고 장애물이 있는 환경에서 무인 이동체를 운영할 때 고려할 사항을 검토하였다. 육상환경 이동을 위해 4족 보행 로봇을 활용하였으며 항공 환경 이동을 위해 쿼드콥터 드론이 활용되었다. 수중환경의 갱도에 투입하기 위해서 수중 드론이 사용되었다. 무인 이동체를 실제 광산 현장에 투입하여 폐광 현장용 이동체가 고려해야 할 변수들을 도출하였다. 폐광산 갱도 형상화용 센서로서 2차원 영상 기반의 solid-state 라이다가 사용되었다. 방사형으로 측정되는 라이다의 특성을 고려하여 고정 경사각을 두어 회전시켜 운영하여 갱도 형상화를 위한 효율성을 높이고 동시에 장애물 감지도 같이 수행할 수 있도록 제안하였다. Solid-state 라이다를 이용하여 측정데이터로부터 센서의 자세와 로봇의 자세를 반영하여 현실 좌표계 데이터로 변환하기 위한 계산기법이 도출되었다. 라이다 센서와 무인 비행체가 결합하여 실제 현장에 투입하여 갱도 형상을 추출하였다. 마지막으로 실제 현장에서 효용성을 높이기 위한 요소를 도출하였다.

Analysis of Wide-gap Semiconductors with Superconducting XAFS Apparatus

  • Shiki, S.;Zen, N.;Matsubayashi, N.;Koike, M.;Ukibe, M.;Kitajima, Y.;Nagamachi, S.;Ohkubo, M.
    • Progress in Superconductivity
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    • 제14권2호
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    • pp.99-101
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    • 2012
  • Fluorescent yield X-ray absorption fine structure (XAFS) spectroscopy is useful for analyzing local structure of specific elements in matrices. We developed an XAFS apparatus with a 100-pixel superconducting tunnel junction (STJ) detector array with a high sensitivity and a high resolution for light-element dopants in wide-gap semiconductors. An STJ detector has a pixel size of $100{\mu}m$ square, and an asymmetric layer structure of Nb(300 nm)-Al(70 nm)/AlOx/Al(70 nm)-Nb(50 nm). The 100-pixel STJ array has an effective area of $1mm^2$. The XAFS apparatus with the STJ array detector was installed in BL-11A of High Energy Accelerator Research Organization, Photon Factory (KEK PF). Fluorescent X-ray spectrum for boron nitride showed that the average energy resolution of the 100-pixels is 12 eV in full width half maximum for the N-K line, and The C-K and N-K lines are separated without peak tail overlap. We analyzed the N dopant atoms implanted into 4H-SiC substrates at a dose of 300 ppm in a 200 nm-thick surface layer. From a comparison between measured X-ray Absorption Near Edge Structure (XANES) spectra and ab initio FEFF calculations, it has been revealed that the N atoms substitute for the C site of the SiC lattice.

수소저장합금을 이용한 SMH 액추에이터 시스템 개발 (Development of SMH Actuator System Using Hydrogen-Absorbing Alloy)

  • 권대규;홍경주;김경;전원석;방두열;이성철;김남균
    • 제어로봇시스템학회논문지
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    • 제13권11호
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    • pp.1067-1073
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    • 2007
  • This paper presents development of an special metal hydride(SMH) actuator system using a peltier module. The newly developed simple SMH actuator, consisting of the plated hydrogen-absorbing alloy as a power source, Peltier elements as a heat source and a cylinder with metal bellows as a functioning part, has been developed. The SMH actuator is characterized by its small size, low weight, noiseless operation and a compliance similar to that of human body. A new SMH actuator that uses reversible reactions between the heat energy and mechanical energy of a hydrogen absorbing alloy. It is well known that hydrogen-absorbing alloys can reversibly absorb and desorb a large amount of hydrogen, more than about 1000 times of their own volume. To improve the thermal conductivity of the hydrogen-absorbing alloy, an electro-less copper plating has been carried out. For this purpose, the effects of the electro-less copper plating and the dynamic characteristics of the SMH actuator have been studied. The hydrogen equilibrium pressure increases and hydrogen is desorbed by heating the hydrogen-absorbing alloys, whereas by cooling the alloys, the hydrogen equilibrium pressure decreases and hydrogen is absorbed. The SMH actuator has the characteristic of being light and easy to use. Therefore, it is suitable for medical and rehabilitation applications.

제주의 지역주의 건축 -1950년대 이후의 흐름과 표현양상에 대한 비평적 고찰 - (Regionalism Architecture in Jeju Island - A Critical Review of its Trends and Characteristics, since 1950's -)

  • 양상호;박순관
    • 건축역사연구
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    • 제18권6호
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    • pp.7-22
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    • 2009
  • This writing is to understand some trends and its meaning of Regionalism Architecture in Jeju Island since 1950's. This thesis began with an interest in the identity crisis implicit in the simultaneous striving for modernism and the so-called regional values in Jeju Island. Regionalism is a response in architectural terms to re-establish continuity in a given place between past and present forms, and also a unique result related to particular places, cultures and climates in region. This is one way of looking at the issues of regional identity. The study began by observing the general characteristics of contemporary ideas on Regionalism in Jeju architecture. This means that tracing the history of development of Regionalism architecture in research area is not the focus of this thesis. The thesis demonstrates that Regionalism architectures in Jeju shows some trends related to the local cultural elements (or ideas) such like traditional architectural forms, natural environment, local construction-materials, etc. In summation, in the perspective of Regionalism architecture,mostofbuildingsin Jeju bring out them only as vernacular architecture as it was once produced, by the simple combination and imitation without any creative interaction of the regional culture. I stress the point in this paper that, in over the last fifty years, there have been very narrowed attempts to design the regional values in the main, and also point out that there are problems in the manner in which local architects have gone about trying to define the regional themes. So, a grate depth is required to understand the phenomenon that Jeju area is with its various nuances of traditions, art, culture, climate and light and then to reinterpret it into the modern building type with all the high sense. In addition to that, some conclusions are reached on future directions and the significance of the study.

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Electrode formation using Light induced electroless plating in the crystalline silicon solar cells

  • 정명상;강민구;이정인;김동환;송희은
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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    • pp.347.1-347.1
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    • 2016
  • Screen printing is commonly used to form the electrode for crystalline silicon solar cells. However, it has caused high resistance and low aspect ratio, resulting in decrease of conversion efficiency. Accordingly, Ni/Cu/Ag plating method could be applied for crystalline silicon solar cells to reduce contact resistance. For Ni/Cu/Ag plating, laser ablation process is required to remove anti-reflection layers prior to the plating process, but laser ablation results in surface damage and then decrease of open-circuit voltage and cell efficiency. Another issue with plating process is ghost plating. Ghost plating occurred in the non-metallized region, resulting from pin-hole in anti-reflection layer. In this paper, we investigated the effect of Ni/Cu/Ag plating on the electrical properties, compared to screen printing method. In addition, phosphoric acid layer was spin-coated prior to laser ablation to minimize emitter damage by the laser. Phosphorous elements in phosphoric acid generated selective emitter throughout emitter layer during laser process. Then, KOH treatment was applied to remove surface damage by laser. At this step, amorphous silicon formed by laser ablation was recrystallized during firing process and remaining of amorphous silicon was removed by KOH treatment. As a result, electrical properties as Jsc, FF and efficiency were improved, but Voc was lower than screen printed solar cells because Voc was decreased due to surface damage by laser process. Accordingly, we expect that efficiency of solar cells could be improved by optimization of the process to remove surface damage.

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유아(幼兒)의 놀이복 디자인 개발 연구 (Design Development for Toddler's Playwear)

  • 이연희;박혜원
    • 한국의류학회지
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    • 제33권8호
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    • pp.1227-1240
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    • 2009
  • This study examines the actual conditions of toddler playwear preference survey for design and function. The study develops proper indoor and outdoor playwear for toddlers based on the analysis. A survey of 200 parents with toddlers between 2 and 6 years old and 120 teachers was conducted to find the conditions and needs for playwear along with the necessary design elements. Second, 6 designs including 3 designs for indoor playwear and 3 designs for outdoor playwear were made. These designs emphasized on soil contamination part, color, pattern, form, material, detail, and fasteners. Art play and cooking play are considered for indoor playwear and ways to decrease contamination on sleeve hem, elbow, chest, and knee were determined through the use of yellow, green, and blue colors. Applying a character and separate top with sleeves were determined. Light with breathable and waterproof fabric was determined. The correct amount of Velcro fasteners or buttons was determined for front fastening in addition a pocket was considered necessary as a detail part. The common design for both boys and girls along with a proper design for diverse play were determined. For outdoor playwear, water play, sand play, movement play, and ecology experience are considered and ways to decease contamination on hip, sleeve hem, and knee should be applied to the design as determined through the use of yellow, green, blue, and red colors. The demands for pattern, form, material, and details were similar to indoor playwear. Zipper and buttons for front fastening were determined. These final 6 playwear designs are presented using CAD WALK DESIGNWARE.

면역증강성 다당 생산을 위한 참당귀 세포배양의 최적조건 (Optimal Conditions for the Production of Immunostimulating Polysaccharides from the Suspension Culture of Angelica gigas Cells.)

  • 안경섭;서원택;심웅섭;김익환
    • 한국미생물·생명공학회지
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    • 제26권2호
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    • pp.130-136
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    • 1998
  • 참당귀 세포(Angelica gigas H4)를 현탁배양하여 면역 증강성 다당을 생산하기 위한 최적배지 설계 및 생산조건 최적화 연구를 수행하였다. 우선 세포의 성장에 가장 좋은 배지로서 Schenk and Hildebrandt(SH) 배지를 선택하여 배양한 결과 $25^{\circ}C$, 암배양조건에서 각각 15.8g DCW/l와 0.85 g/l의 세포 및 다당을 얻을 수 있었다. 한편 다당 생산용 배지의 개발을 위하여 여러 가지 식물세포배양용 배지 중에서 다당 생산능이 가장 높은 배지로서 Gamborg B5 배지를 선정하였으며 B5 배지를 변형하여 면역증강성 다당생산을 위한 최적배지(PPM)를 개발하였다. 그리고 최적배지를 이용한 당귀 세포증식과 다당 생산을 위한 최적 pH는 6.0-6.5, 배양온도는 $20^{\circ}C$, 그리 고 광조건보다는 암조건이 좋은 것으로 밝혀졌다. 상기 최적조건에서의 최대 세포증식과 다당생산은 각각 14.8 g/l, 1.5 g/l 이었다.

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조선소 시설물의 강풍 위험 평가 (Risk Assessment of Strong Wind over Industrial Facilities in Shipyards)

  • 이승수;김학선;이영규;심규철
    • 한국방재학회 논문집
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    • 제9권4호
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    • pp.21-28
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    • 2009
  • 국내 조선소는 빈번하게 태풍에 의해 영향을 받는 해안에 위치하며, 풍하중에 취약한 많은 경량 구조의 시설물들로 이루어져 있다. 본 연구에서는 주변 지형과 조선소내부 건물의 영향까지 고려하여 시설물의 강풍에 대한 위험 분석을 수행하였다. 몬테카를로 시뮬레이션에 의해 대상 지역의 극한 풍속을 추정하여 전산유체역학 해석을 위한 입사풍속으로 설정하였으며, 난류 유동을 고려한 전산 유체 해석을 이용하여 시설물 표면에 발생하는 풍압과 조선소 사업장 내의 풍속 분포를 추정하였다. 결과로서 일부 시설물에는 설계 하중보다 높은 풍하중이 작용하여 보강이 요구되는 것으로 판단되며, 향후 설계 풍하중을 고려하는 경우 주변의 국부적 지형 변화와 건물 배치를 고려해야 할 것으로 나타났다.

SMH 액추에이터 시스템 설계 및 개발 (Design and Development of SMH Actuator System)

  • 권대규;최광훈;방두열;이성철;김남균
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.551-555
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    • 2005
  • This paper presents the temperature-pressure characteristics of SMH actuator using a peltier module. The simple SMH actuator, consisting of the plated hydrogen-absorbing alloy as a power source, Peltier elements as a heat source and a cylinder with metal bellows a functioning part has been developed. The SMH actuator is characterized by its small size, low weight, noiseless operation and a compliance similar to that of the human body. A new special metal hydride(SMH) actuator that uses the reversible reaction between the heat energy and mechanical energy of a hydrogen absorbing ally. It is well known that hydrogen-absorbing alloys can reversibly absorb and desorb a large amount of hydrogen, more than about 1000 times as their own volume. To improve the thermal conductivity of the hydrogen-absorbing alloy, an electro-less copper plating has been carried out. The effects of the electro-less copper plating and the dynamic characteristics of the SMH actuator have been studied. The hydrogen equilibrium pressure increases and hydrogen is desorbed by heating the hydrogen-absorbing alloys, whereas by cooling the alloys, the hydrogen equilibrium pressure decreases and hydrogen is absorbed. Therefor, the SMH actuator has the characteristic of being light and easy to use and so is suitable for use in medical and rehabilitation applications.

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한국산 잎담배 중의 몇가지 무기성분에 관한 조사 연구 (A Study on Several Mineral Elements in Korea Tobacco Leaves)

  • 김찬호;김정옥
    • 한국연초학회지
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    • 제1권2호
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    • pp.103-110
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    • 1979
  • 1978년 국내산 잎담배에 대하여 Ha,Mg,Fe,Ui, Cu, Mn, Zn의 함량을 조사연구하였다. 그 결과 Mg은 5370$\mu{g}/g-7640\mu{g}/g$으로 Burley>Flue-cured>Native의 순이었다. Mn과 Fe는 210$\mu{g}/g-1290\mu{g}/g$, 330$\mu{g}/g-590\mu{g}/g$으로 Burley >Flue -cured >Native의 순이었다.Zn는 50$\mu{g}/g-100\mu{g}/g$으로서 Native>Burley>Flue -cured의 순이었으며 Na, Ni, Cu는 세품종이 비슷하였으며, Na는 200~300$\mu{g}/g$,Ni는 $10\mu{g}/g$, Cu는 7~9$\mu{g}/g$이었다. 이들 무기성분의 함량과 등급과는 Na, Mg, Mn, Ni, Cu는 후옅 5, 3,1등의 순으로 감소하는 경향을 보이다가 박엽 1,3,5등의 순으로 점차로 증가하는 상향곡선으로 나타났다. 등급과 무기성분과의 상관관계는 Hicks, SC-72, Va 115세품종이 Mg와 0.l%수준에서 고도의 유의성이 있었다.

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