• 제목/요약/키워드: electron impact

검색결과 344건 처리시간 0.026초

SPECTRAL DIAGNOSTICS OF THE ENERGETIC PARTICLES IN SOLAR FLARES

  • FANG C.;DING M. D.;HENOUX J. C.;GAN W. Q.
    • 천문학회지
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    • 제29권spc1호
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    • pp.295-298
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    • 1996
  • Non-LTE calculations, with the non-thermal ionization effects included, indicated that for electron bombardment, the H$\alpha$ line is widely broadened and shows a strong central reversal. Significant enhancements at the line wings of Ly$\alpha$ and Ly$\beta$ are also predicted at the beginning of the impulsive phase of flares. For the proton bombardment, no strong broadening and no large central reversal are expected. However, due to proton-hydrogen charge exchange, the enhancements at the red wings of Ly$\alpha$ and Ly$\beta$ lines at the early impulsive phase of flares are significant. Our results show that the electron beam can also in some cases generate visible and UV continuum emission in white-light flares. However, at the onset phase, a negative flare may appear within several seconds, due to the increase of the H- opacity. Another spectroscopic signature of energetic particles, i.e. the impact polarization of atomic lines, is also mentioned.

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다구찌 방법을 이용한 AISI 4130재료에서 EBW공정의 용접 변수 영향 (Effect of Welding Variables for EBW Process in AISI 4130 by Taguchi Method)

  • 김원훈
    • Journal of Welding and Joining
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    • 제15권6호
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    • pp.66-77
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    • 1997
  • In the present work, Taguchi method for electron beam welding(EBW) process in AISI 4130 steel plate has been adopted for investigating the contribution of effect of welding variables. $A L_8(2^7)$ orthogonal array is adopted to obtain the effect of adjustment parameters. The adjustment parameters consist of accelerating voltage, beam current, travel speed and focus currrent. And the quality features selected for the EBW process are bead width of weldment, reinforcement, penetration depth, undercut and area of weld metal. Variance analysis is performed in order to check the effect of adjustment parameters on EBW. The mechanical properties of electron beam welded joints for each heat treatment conditions are investigated in comparison with those of base metal, especially from the view point of tensile and impact properties.

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Numerical Modeling of an Inductively Coupled Plasma Sputter Sublimation Deposition System

  • Joo, Junghoon
    • Applied Science and Convergence Technology
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    • 제23권4호
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    • pp.179-186
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    • 2014
  • Fluid model based numerical simulation was carried out for an inductively coupled plasma assisted sputter deposition system. Power absorption, electron temperature and density distribution was modeled with drift diffusion approximation. Effect of an electrically conducting substrate was analyzed and showed confined plasma below the substrate. Part of the plasma was leaked around the substrate edge. Comparison between the quasi-neutrality based compact model and Poisson equation resolved model showed more broadened profile in inductively coupled plasma power absorption than quasi-neutrality case, but very similar Ar ion number density profile. Electric potential was calculated to be in the range of 50 V between a Cr rod source and a conductive substrate. A new model including Cr sputtering by Ar+was developed and used in simulating Cr deposition process. Cr was modeled to be ionized by direct electron impact and showed narrower distribution than Ar ions.

Optimization of MgO secondary electron emission in plasma displays, by the adoption of a suitable getter configuration;Part I: MgO degradation studies

  • Riva, Mauro;Bonucci, Antonio;Carretti, Corrado;Han, Yong-Gyu;Choi, Eun-Ha
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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    • pp.220-223
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    • 2007
  • The key role of MgO is well recognized in PDP's technology. During manufacturing, significant contamination of the oxide occurs. Getters can compete against the impurities sorption speed of the oxide layer. The analysis of the impact of a suitable getter configuration on the operational parameters of PDP's is the final goal of this study.

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Changes in the Optogalvanic Signal Amplitude in a Hollow Cathode Discharge

  • Lee, Jun-Hoi;Koo, Kyung-Wan;Lee, Ki-Sik
    • Transactions on Electrical and Electronic Materials
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    • 제10권6호
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    • pp.212-216
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    • 2009
  • The spatial distribution of the optogalvanic (OG) signal in argon at the 801.489 nm ($1s_5-2p_8$ transition at the metastable level in Paschen notation) was investigated in the radial direction of a hollow cathode discharge tube. The results of this experiment showed that the OG signal amplitude decreases in accordance with the following two conditions; first, the level of discharge current and second, the distance from the cathode dark space. These results can be quantified by analyzing the electron density profile along the discharge regions, which can directly influence the collisional ionization induced by electron impact.

실리콘 스핀트로닉스 (Silicon Spintronics)

  • 민병철
    • 한국자기학회지
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    • 제21권2호
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    • pp.67-76
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    • 2011
  • 반도체 스핀트로닉스는 자성체와 반도체를 결합하여 반도체 내에서의 전자 스핀을 이용하는 새로운 형태의 자성체-반도체 융합기술이며, 스핀 트랜지스터는 반도체 스핀트로닉스의 대표적인 소자이다. 이 소자를 실현하면, 반도체 내에 전자 스핀을 주입, 제어, 검출함으로써, 한 소자 내에서 정보처리와 정보저장을 동시에 수행할 수 있을 것으로 기대된다. 특히, 반도체 산업의 주축 물질인 실리콘을 이용하여 스핀 트랜지스터를 실현한다면, 이는 정보 산업에 중대한 영향을 미칠 것으로 예상된다. 이 글에서는 최근 실리콘 스핀트로닉스 분야에서의 주요한 진전을 소개하고, 앞으로의 기술적 과제에 대하여 간단히 기술하고자 한다.

ELECTRICAL BREAKDOWN INITIATION OF ANODIC FILMS DURING ANODIZING IN MOLTEN BISULPHATE MELT

  • Han, S.H.;Thompson, G.E.
    • 한국표면공학회지
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    • 제32권3호
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    • pp.341-343
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    • 1999
  • The morphology and composition of anodic films, formed on aluminium at various current densities, in the range $1-100{\;}Am^{-2}$, in the molten bisulphate melt at different temperatures (418-498K), have been studied using transmission electron microscopy of ultramicrotomed film sections, and ion beam thinned films. The first sign of incipient breakdown revealed by transmission electron microscopy of stripped films, is always the appearance of dark regions about 1,000 nm in diameter, representing local overgrowth of the film. The breakdown mechanism is closely related to thermal effects, because temperature rises at regions representing local overgrowth in the stripped films were observed at voltages close to the breakdown voltage, likely arising through impact ionization.

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Characterization of Nano-Grained ZnO Piezoelectric Thin Films Deposited under Various Sputtering Conditions

  • Zhang, Ruirui;Lee, Eunju;Yoon, Giwan
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2009년도 추계학술대회
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    • pp.428-430
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    • 2009
  • 본 논문은 RF 마그네트론 스퍼터링 시스템을 이용하여 p-Si (100) 기판위에 증착된 C축 배향을 가지는 ZnO 박막의 특성을 분석하고 있다. 증착 전력, 공정 압력, 반응가스로 사용된 산소 가스의 비율과 같은 증착 조건들을 변화시켰을 때, ZnO 박막의 결정구조의 변화를 분석한다. 증착된 ZnO 박막의 결정 구조는 주사 전자 현미경(scanning electron microscope, SEM)을 이용하여 조사되었다. 분석 결과 증착 파라미터들은 증착된 ZnO 박막의 결정(grain) 크기와 배향 특성에 강한 영향을 미친다는 사실을 알 수 있다.

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Excretory-Secretory Products of Trichomonas vaginalis Cause Apoptosis in Mouse Sperm in Vitro

  • Keum, Jihyun;Roh, Jaesook;Ryu, Jae-Sook;Ryu, Ki-Young
    • Parasites, Hosts and Diseases
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    • 제60권5호
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    • pp.357-360
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    • 2022
  • Excretory-secretory products (ESP) of T. vaginalis have been shown to inhibit sperm motility, viability, and functional integrity, leading to a decreased fertilization rate in vitro. This study investigated whether T. vaginalis induce apoptosis and ultrastructural changes of sperm using flow cytometry and electron microscopy. Incubation of sperm with T. vaginalis ESP increased phosphatidylserine externalization and DNA fragmentation, and decreased mitochondrial membrane potential. Transmission electron microscopy of sperm incubated with ESP revealed abnormal features such as distorted heads, broken necks, and acrosomes exocytosis. This is the first report that demonstrates a direct impact of T. vaginalis ESP on sperm apoptosis and architecture in vitro.

물질전과정평가(MLCA)를 통한 TiN-Zr 수소분리막의 환경성 평가 (Evaluation of TiN-Zr Hydrogen Permeation Membrane by MLCA (Material Life Cycle Assessment))

  • 김민겸;손종태;홍태환
    • 청정기술
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    • 제24권1호
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    • pp.9-14
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    • 2018
  • 본 연구에서는 TiN-Zr 수소분리막의 제조 공정에 대한 환경 영향 특성을 분석하기 위해 물질전과정평가를 수행하였다. Material Life Cycle Assessment (MLCA)의 소프트웨어로는 Gabi를 사용하였다. 이를 통하여 각 공정에서 미치는 영향과 특성화 별 환경영향평가를 수행하였다. 졸겔법에 의해 전구체 TiN을 합성하고 볼밀법을 이용하여 지르코늄을 코팅하였다. 이를 CIP, HPS에 의해 디스크 형으로 제작하였고 주사전자현미경(scanning electron microscopy, SEM), 에너지분산형 분광분석법(energy dispersive X-ray spectroscopy, EDS), X-선 회절분석기(X-ray diffraction, XRD), 열중량분석(thermo gravimetry/differential thermal analysis, TG/DTA), 비표면적분석(Brunauer, Emmett, Teller, BET) 및 가스 크로마토그래프 시스템(gas chromatograph system, GP)을 이용하여 분리막의 야금학적, 물리학적, 열역학적 특성을 분석하였다. 또한, 물질전과정평가를 위해 수행한 특성화와 정규화 결과, 영향범주 별 환경영향은 해양 생태 독성이 94%, 수계 생태 독성 2%, 인간독성 2%의 기여도를 보였다. 아울러, 제조공정 중 전기 사용이 생태계 영향에 큰 영향을 미친다는 것을 알 수 있었다. 물질 전 과정 평가는 Eco-Indicator '99 (EI99)와 CML 2001 방법론을 기반으로 분석하였다.