• 제목/요약/키워드: material flow

검색결과 3,377건 처리시간 0.032초

77K에서 트랜지스터 특성을 나타내는 링크의 제작 (Fabrication of the weak link with the the Transistor Characteristics in 77 K)

  • 강형곤;임성훈;고석철;주철원;한병성
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2001년도 하계학술대회 논문집
    • /
    • pp.921-926
    • /
    • 2001
  • The link for the Superconducting Flux Flow Transistor (SFFT) which is based on the flux flow has been fabricated by the ICP etching methods. The channel width and the thickness of the SFFT were a 3 ${\mu}$m and about 300 nm, respectively. The superconducting characteristic of the link was measured by the x-ray diffraction and the E.D.S.. The SFFT etched by ICP showed an I-V characteristic like the three terminal transistor.

  • PDF

질소와 아르곤 가스를 이용한 플라즈마의 전기적특성 연구 (The study of Electrical Characteristic of Plasma by Nitrogen and Argon)

  • 김동구;박기배;한상도;한상옥
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 1998년도 추계학술대회 논문집
    • /
    • pp.323-326
    • /
    • 1998
  • The current-voltage characteristic have been measured in a gas stabilized DC arc generated in a non-transferred arc plasma torch operating on a mixture of argon and nitrogen. Relation between voltage and current to these arcs has been examined by plasma power and current under different flow rates and gas mixture ratios. Firstly, the voltage and current of arc plasma used argon was measured and secondly, in argon-nitrogen mixed gas regime, the flow rate of nitrogen was increased slowly. When the flow rate of nitrogen was increased, electrode drop of potential was increased.

  • PDF

와전류식 전자유량계 설계제작에 대한 실험적 특성연구 (A Study on the Characteristics in Design and Made of Eddy Current Flowmeter)

  • 황종선;남호윤;이용범;김용균;김동화
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 1997년도 춘계학술대회 논문집
    • /
    • pp.281-284
    • /
    • 1997
  • In this paper, the eddy current flow meter with 4-coil group is designed and made on the basis of theory, and its characteristics is considered through dry test flow experiments. The biggest output signal varied with wave form and frequency, and 900Hz in rectangular wave, 27.12kHz in sine wave. The conductivity is bigger, the output signal is bigger and has a linearity between both relation, and also The Magnetic Reynolds Number and output characteristics. The flow faster and the output singnal is bigger.

  • PDF

THE EFFECTS OF HEAT INPUT AND GAS FLOW RATE ON WELD INTEGRITY FOR SLEEVE REPAIR WELDING OF IN-SERVICE GAS PIPELINES

  • Kim, Young-pyo;Kim, Woo-sik;Bani, In-wan;Oh, Kyu-Hwan
    • 대한용접접합학회:학술대회논문집
    • /
    • 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
    • /
    • pp.390-395
    • /
    • 2002
  • The experimental and numerical study has been conducted on the sleeve repair welding of API 5L X65 pipeline. SMA W and GTAW were applied to weld the sleeve. The macrostructure and hardness of repair welds have been examined. The [mite element analysis of the multi-pass sleeve-fillet welding has been conducted to validate the experiment and investigate the effects of in-service welding conditions. The effect of gas flow rate on the hydrogen cracking was investigated. The effect of internal pressure on residual stresses and plastic strain was investigated. The allowable heat input was predicted considering the maximum temperature of inner surface of pipe and cooling rate at CGHAZ.

  • PDF

사파이어 기판 위에 증착된 ZnO 박막의 기판온도와 산소 가스량에 따른 특성 (Effect of Variation of Substrate Temperature and Oxygen Gas Flow of the ZnO Thin Films Deposited on Sapphire)

  • 김재홍;이천
    • 한국전기전자재료학회논문지
    • /
    • 제18권7호
    • /
    • pp.652-655
    • /
    • 2005
  • ZnO thin films on (001) $Al_2O_3$ substrates have been deposited by pulsed laser deposition(PLD) technique using an Nd:YAG laser with a wavelength of 266 nm. The influence of the deposition parameters, such as oxygen gas flow, substrate temperature and laser energy density variation on the properties of the grown film, was studied. The experiments were performed for substrate temperatures in the range of $300\~450^{\circ}C$ and oxygen gas flow rate of $100\~900$ sccm. We investigated the structural and optical properties of ZnO thin films using X-ray diffraction(XRD) and photoluminescence(PL).

플라즈마 식각을 이용한 초전도 자속 흐름 트랜지스터 제작 (Fabrication of Superconducting Flux Flow Transistor using Plasma etching)

  • 강형곤;임성훈;고석철;한윤봉;한병성
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2002년도 하계학술대회 논문집
    • /
    • pp.74-77
    • /
    • 2002
  • The channel of the superconducting Flux Flow Transistor has been fabricated with plasma etching method using ICP. The ICP conditions were 700 W of ICP power, 150 W of rf chuck power, 5 mTorr of the pressure in chamber and 1:1 of Ar : Cl$_2$, respectively. The channel etched by plasma gas showed superconducting characteristics of over 77 K and superior surface morphology. The critical current of SFFT was altered by varying the external applied current. As the external applied current increased from 0 to 12 mA, the critical current decreased from 28 to 22 mA. Then the obtained r$\sub$m/ values were smaller than 0.1Ω at a bias current of 40 mA. The current gain was about 0.5. Output resistance was below 0.2 Ω.

  • PDF

가스흐름 제어에 의한 균일한 다결정 3C-SiC 박막 성장 (The uniform polycrystalline 3C-SiC thin film growth by the gas flow control)

  • 윤규형;정귀상
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
    • /
    • pp.92-92
    • /
    • 2008
  • The surface flatness of heteroepitaxially grown 3C-SiC thin films is a key factor affecting electronic and mechanical device applications. This paper describes the surface flatness of polycrystalline 3C-SiC thin films by the gas flow control according to the location change of geometric structure. The polycrystalline 3C-SiC thin film was deposited by APCVD(Atmospheric pressure chemical vapor deposition) at $1200^{\circ}C$ using HMDS(Hexamethyildisilane : $Si_2(CH_3)_6)$ as single precursor, and 5 slm Ar as the main flow gas. According to the location of geometric structure, surface fringes and flatness changed. It shows the distribution of thickness is formed uniformly in the specific location of the geometric structure.

  • PDF

RESPONSES OF THE TRANSITION REGION TO DOWNWARD AND UPWARD FLOWS

  • YUN H. S.;CHAE J.-C.;POLAN A. I.
    • 천문학회지
    • /
    • 제29권spc1호
    • /
    • pp.339-340
    • /
    • 1996
  • In the present study we examine physical characteristics of a thin and rigid magnetic flux tube with a steady flow inside, which is embedded vertically upward in the solar atmosphere. We found from this study that (1) The downward material flow gives rise to a dominant heating in the flux tube which works with the conductive heating in the same direction. However, the upflow flow creates a dominant cooling which works against the conductive heating, resulting in a steeper temperature gradient with a shallower transition region. (2) Since the thickness of the transition region determines the material content in the transition region, a broader transition region of the downflow tube produces a larger differential measure.

  • PDF

Adaptive Moment-of-Fluid Method:a New Volume-Tracking Method for Multiphase Flow Computation

  • Ahn, Hyung-Taek;Shashkov, Mikhail
    • 한국전산유체공학회:학술대회논문집
    • /
    • 한국전산유체공학회 2008년도 학술대회
    • /
    • pp.334-336
    • /
    • 2008
  • A novel adaptive mesh refinement (AMR) strategy based on the Moment-of-Fluid (MOF) method for volume-tracking dynamic interface computation is presented. The Moment-of-Fluid method is a new interface reconstruction and volume advection method using volume fraction as well as material centroid. The mesh refinement is performed based on the error indicator, the deviation of the actual centroid obtained by interface reconstruction from the reference centroid given by moment advection process. Using the AMR-MOF method, the accuracy of volume-tracking computation with evolving interfaces is improved significantly compared to other published results.

  • PDF

Adaptive Moment-of-Fluid Method: a New Volume-Tracking Method for Multiphase Flow Computation

  • Ahn, Hyung-Taek;Shashkov, Mikhail
    • 한국전산유체공학회:학술대회논문집
    • /
    • 한국전산유체공학회 2008년 추계학술대회논문집
    • /
    • pp.334-336
    • /
    • 2008
  • A novel adaptive mesh refinement (AMR) strategy based on the Moment-of-Fluid (MOF) method for volume-tracking dynamic interface computation is presented. The Moment-of-Fluid method is a new interface reconstruction and volume advection method using volume fraction as well as material centroid. The mesh refinement is performed based on the error indicator, the deviation of the actual centroid obtained by interface reconstruction from the reference centroid given by moment advection process. Using the AMR-MOF method, the accuracy of volume-tracking computation with evolving interfaces is improved significantly compared to other published results.

  • PDF