• 제목/요약/키워드: cell width

검색결과 595건 처리시간 0.029초

培養 鷄胚 筋細胞分化에 미치는 紫外線의 영향 (Effects of Ultraviolet Irradiation on the Differentiation of Cultured Chicken Pectoralis Muscle Cells)

  • Chung, Hae-Moon;Nham, Sang-Uk
    • 한국동물학회지
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    • 제24권4호
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    • pp.189-200
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    • 1981
  • 12일간 배양한 계배에서 떼어낸 근모세포에 자외선을 조사하면 근육 분화에 심한 변화를 유발시킬수 있다. 본 연구에서는 자외선이 세포분열 및 근섬유로의 전환, 근모세포와 근섬유의 형태에 미치는 영향을 조사하였다. 자외선을 받은 세포들은 크기가 작아지고 또 적은 수의 세포들이 근섬유 형성에 참여하기 때문에 근섬유의 직경이 좁아지고 길이 또한 작아진다. 자외선이 세포분열과 세포의 융합에 미치는 영향은 배양을 시작한 후 이른 시기에 조사할수록 그 효과가 크다. 또한 자외선의 양을 증가시키면 그 효과가 커져 지나친 양을 조사하면 세포에 치사작용을 나타낸다. 따라서 자외선에 의한 세포 밀도의 감소가 근섬유 형성의 저하를 초래하는 것으로 사료되어 이에 본 연구와 타 실험실에서 얻은 정보를 바탕으로 세포 융합 능력 감소의 원인에 대하여 토의하였다.

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그라비아 인쇄를 위한 Laser Stream Patterning 개선 (Laser Stream Patterning Improvement for Gravure Printing)

  • 안태용;김한규;이동훈
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2001년도 추계학술대회 논문집
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    • pp.186-189
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    • 2001
  • The main method in micro-etching process, used in manufacturing semiconductors, electronic components, circuits, is Photo Masking method that exposes and develops on the photo-sensitivity solutions or films. This method enables one to process highly precisely, $\pm$0.03 mm in end line location area. But this has limits in a high speed / wide width process, difficulties in endless masking, and the problem of high price. We have developed the direct masking method to make use of Gravure printing, widely used in grocery packing sheet printing. We made cylinder tools to influence the masking quality by laser stream process. We have confirmed that the end line location accuracy in the line width of the product is improved from 0.12 mm to $\pm$0.07 mm level, after etching process.

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CFD에 의한 펌프장 Sump내 유동해석 (Flow Analysis around within Sump in a Pump Station using by the CFD)

  • 노형운;김재수;서상호
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2002년도 유체기계 연구개발 발표회 논문집
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    • pp.89-94
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    • 2002
  • n general, the function of intake structure, whether it be a open channel, a fully wetted tunnel, a sump or a tank, is to supply an evenly distributed flow to a pump station. An even distribution of flow, characterized by strong local flow, can result in formation of surface or submerged vortices, and with certain low values of submergence, may introduce air into pump, causing a reduction of capacity and efficiency, an increase in vibration and additional noise. Uneven flow distribution can also increase or decrease the power consumption with a change in total developed head. To avoid these sump problems pump station designers are considered intake structure dimensions, such as approaching upstream, baffle size, sump width, width of pump cell and so on. From this background, flow characteristics of intake within sump are investigated numerically to obtain the optimal sump design data. The sump model is designed in accordance with HI code.

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AC 플라즈마 디스플레이패널의 방전개시전압에 모델과 실험의 비교에 관한 연구 (Comparision Study Between Modeling and Experiment of the Breakdown Voltage for AC Plasma Display Panel)

  • 박장식
    • 한국전기전자재료학회논문지
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    • 제13권12호
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    • pp.1039-1044
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    • 2000
  • Breakdown voltage model and expertiments are compared for discharge cells of AC plasma display panel. In the model, discharge paths are assumed to be initial electric field lines and the one-dimensional continuity equation is applied to the charged particle transport at each field line. The comparisons are performed in the wide range of gas pressure (50-600torr), Xe partial pressure over total pressure (1-6%), sustain electrode gap(100-1000$\mu\textrm{m}$), wall height(130, 300$\mu\textrm{m}$), and voltage pulse width(2-6${\mu}$s). The presented breakdown voltage model well agree with experiments in the above wide range. The increase of breakdown voltage with the decrease of the width(L) of protruding electrode is also described by the model.

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광 결정의 나노 구조를 갖는 Rugate 다공성 실리콘의 반치폭 값에 대한 특성 분석 (Characteristic Analysis of Band Width Based on Rugate Porous Silicon Containing Photonic Nanocrystal)

  • 권용희
    • 통합자연과학논문집
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    • 제2권1호
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    • pp.41-44
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    • 2009
  • Photonic crystals containing multiple rugate structure are prepared by electrochemical etchings. Typically etched rugate PSi prepared in this study. Etching is carried out in a Teflon cell by using a two-electrode configuration with a Pt mesh counter electrode. They exhibit sharp photonic band gaps in the optical reflectivity spectrum. This reflectivity can be tuned to appear anywhere in the visible to near-infrared spectral range, depending on the programmed etch waveform. We study the method of full width half maxima and reflectivity index control by using amplitude.

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펌프장에서 Sump내 흡입구 주위의 유동해석 (Flow Analyses around Intake within Sump in a Pump Station)

  • 노형운;김재수;서상호
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2002년도 학술대회지
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    • pp.597-600
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    • 2002
  • In general, the function of intake structure, whether it be a open channel, a fully wetted tunnel, a sump or a tank, is to supply an evenly distributed flow to a pump station. An even distribution of flow, characterized by strong local flow, can result in formation of surface or submerged vortices, and with certain low values of submergence, may introduce air into pump, causing a reduction of capacity and efficiency, an increase in vibration and additional noise. Uneven flow distribution can also increase or decrease the power consumption with a change in total developed head. To avoid these sump problems pump station designers are considered intake structure dimensions, such as approaching upstream, baffle size, sump width, width of pump cell and so on. From this background, flow characteristics of intake within sump are Investigated numerically to obtain the optimal sump design data. The sump model is designed in accordance with HI code.

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용설란(Agave deserti Engelm)에 있어서 기공개폐와 공변세포내 K+와 Na+농도변화와의 관계 (The Relationship between Stomatal Behavior and K+, Na+ Fluctuations of Guard Cells in CAM Plant, Agave deserti E.)

  • 오희목;장남기
    • 아시안잔디학회지
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    • 제11권1호
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    • pp.23-31
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    • 1997
  • The K+ and Na+ contents in the guard cells of Agave which had a characteristic of CAM plant were measured by using "Rolling technique". That results were correspond with the change of the stomatal aperture width. That is to say, stomatal movement of Agave is due to the change of K+and Na+ concentration in the guard cells. As Agave which was used in this experiment showed two peaks of which one was at 3 hour and the other was at 24 hour in stomatal aperture width, it was seemed that Agave had both characteristics of CAM and $C_3$pattern.

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채널 단면형상 변화에 따른 PEMFC 성능 수치 연구 (Numerical Study on the Performance of PEMFC with Various Cross Sections of Channel)

  • 최치환;문정은;이규정
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2005년도 동계학술발표대회 논문집
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    • pp.186-192
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    • 2005
  • A numerical study on the performance of a PEMFC was performed by using a CFD-ACE+commercial program. The effects of width, hight and shape of channel cross section and mass flow rate were investigated. In order to check the validity of the simulation, comparisons were carried out between predictions and experimental data available in the literature and shows the reasonable agreement. It is found that only the width of channel is strongly related to the performance of a PEMFC, while other factors have no marked effects.

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Effect of Auxiliary Address Pulse on Face-to-face Sustain Electrode Structure in AC-PDP

  • Kim, Bo-Sung;Tae, Heung-Sik
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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    • pp.605-608
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    • 2007
  • The discharge characteristics of the face-to-face sustain electrode structure employing auxiliary address pulse are investigated under a sustain driving frequency of 20 kHz and various auxiliary address pulse widths (500 ns, $1{\mu}s$, $2\;{\mu}s$) in the 6-in. test panel (42-in. Full HD grade) with a pressure of 450 Torr and a 4 % Xe-content. The luminance and the luminous efficiency at the auxiliary address pulse width of 500 ns are improved more than these of $1\;{\mu}s$ and $2\;{\mu}s$. At the auxiliary address pulse width of 500 ns, the luminous efficiency shows about 0.96 lm/W at the auxiliary pulse of 90 V and the sustain voltage of 260 V.

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Betatron Radiation of an Off-axis Injected Electron in a Laser Wakefield Accelerator

  • Hwang, Seok-Won;Lee, Hae-June
    • Journal of the Optical Society of Korea
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    • 제13권1호
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    • pp.86-91
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    • 2009
  • The electrons injected into a laser wakefield undergo betatron oscillation and give rise to the emission of intense X-ray radiation. To investigate the generation conditions of the X-rays, the relativistic motion of an electron injected in an off-axis position has been simulated with wakefield profiles which are pre-calculated with a two-dimensional particle-in-cell code. The wakefield with a plasma density of $1.78{\times}10^{18}\;cm^{-3}$ is generated by the laser with an intensity of $1.37{\times}10^{18}\;W/cm^2$ and a pulse width of 30 fs. From the calculation of the single particle motion, the characteristics of the betatron radiation are investigated in the time domain. As the transverse injection position increases, the power and the duration time of the radiation increase, but the width of each pulse decreases.