• 제목/요약/키워드: non-thermal emission

검색결과 111건 처리시간 0.024초

SPECTRAL DIAGNOSTICS OF NON-THERMAL PARTICLES IN THE SOLAR CHROMOSPHERE

  • FANG C.;XU Z.;DING M. D.
    • 천문학회지
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    • 제36권spc1호
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    • pp.55-61
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    • 2003
  • There are at least three effects of the non-thermal particle bombardment on the solar atmosphere: (1) non-thermal ionization and excitation; (2) proton-hydrogen charge exchange; (3) impact line polarization. Due to the non-thermal ionization and excitation effects of electron bombardments in flares, 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. In the case of proton bombardment, less 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 especially of Ly$\beta$ lines at the early impulsive phase of flares are significant. Electron beam can also in some cases generates visible and UV continuum emission in white-light flares. However, at the onset phase, a negative 'black' flare may appear in several seconds, due to the increase of the $H^-$ opacity. The impact polarization of atomic lines can provide complementary information on the energetic particles, the energy transport and deposit in the solar chromosphere. New results of spectropolarimetric analysis for the major flare on July 23, 2002 are also given in the paper.

Non-thermal plasma technology for abatement of pollutant emission from marine diesel engine

  • Panomsuwan, Gasidit;Rujiravanit, Ratana;Ueno, Tomonaga;Saito, Nagahiro
    • Journal of Advanced Marine Engineering and Technology
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    • 제40권10호
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    • pp.929-934
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    • 2016
  • Plasma technology has long been regarded as a key essential tool in many industrial and technological sectors. However, the advancement of plasma technology in marine applications has not been fully realized yet. Herein, we present a short overview on the recent trends in utilization of plasma technology for air-pollution treatment in marine diesel exhaust. Four non-thermal plasma system, including electron beam dry scrubber (EBDS), dielectric barrier discharge (DBD), electron beam-microwave (EB-MW) plasma hybrid system, and plasma-catalytic hybrid system, are described with emphasis on their efficiency in removals of $NO_x$ and $SO_x$ gases. Non-thermal plasma has the great potential to be an efficient and environmentally compatible technique in simultaneous removals of $NO_x$ and $SO_x$ gases from the exhaust of marine diesel engine in the future.

THE CONTRIBUTION TO THE EXTRAGALACTIC γ-RAY BACKGROUND BY HADRONIC INTERACTIONS OF COSMIC RAYS PRODUCING EUV EMISSION IN CLUSTERS OF GALAXIES

  • KUO PING-HUNG;BOWYER STUART;HWANG CHORNG- YUAN
    • 천문학회지
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    • 제37권5호
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    • pp.597-600
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    • 2004
  • A substantial number of processes have been suggested as possible contributors to the extragalactic $\gamma$-ray background (EGRB). Yet another contribution to this background will be emission produced in hadronic interactions of cosmic-ray protons with the cluster thermal gas; this class of cosmic rays (CRs) has been shown to be responsible for the EUV emission in the Coma Cluster of galaxies. In this paper we assume the CRs in the Coma Cluster is prototypic of all clusters and derive the contribution to the EGRB from all clusters over time. We examine two different possibilities for the scaling of the CR flux with cluster size: the number density of the CRs scale with the number density of the thermal plasma, and alternatively, the energy density of the CRs scale with the energy density of the plasma. We find that in all scenarios the EGRB produced by this process is sufficiently low that it will not be observable in comparison with other mechanisms that are likely to produce an EGRB.

소나무류 수관층 및 지표층의 CO2/non-CO2 배출량 분석 연구 (A Study on the Emissions of CO2/non-CO2 for the Crown Layer and Surface Layer of Pine Trees)

  • 박영주;이해평;백창선
    • 한국안전학회지
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    • 제30권1호
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    • pp.111-118
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    • 2015
  • In this study, we carried out the emissions analysis of CO and $non-CO_2$ for the age-classes of various pine trees(Pinus koraiensis, Pinus densiflora, Pinus rigida Mill., Pinus thunbergii Parl.) to estimate of emission factors of the crown layer and surface layer in the forest fire. We used the thermal characteristic analyzer cone heater and NDIR analyzer in order to measure amount of emission. As a result, the major emissions of Pinus koraiensis were $CO_2$ and $CH_4$ and that of Pinus thunbergii Parl. was only CO. The major emissions of the most of pine trees were NO and $N_2O$. The $CO_2$ emission of Pinus thunbergii Parl. was the highest about as $7.26{\times}10^{-2}{\sim}1.63{\times}10^{-1}g$ and next came Pinus densiflora, Pinus koraiensis, Pinus rigida Mill.. And the CO emission of Pinus thunbergii Parl. was about $5.14{\times}10^{-3}{\sim}6.58{\times}10^{-3}g$ and followed by Pinus densiflora, Pinus koraiensis, Pinus rigida Mill.. The emissions of $CH_4$, NO, and $N_2O$ showed small differences between species and the emission of $CH_4$ was $8.37{\times}10^{-5}{\sim}2.55{\times}10^{-4}g$, and NO was $6.65{\times}10^{-5}{\sim}2.0{\times}10^{-4}g$ and $N_2O$ was $1.42{\times}10^{-4}{\sim}2.09{\times}10^{-3}g$ in all species. Particularly, the emission of Pinus thunbergii Parl. was the highest in all pine trees except $CH_4$.

욕실 타일 하자에 대한 비파괴 조사 방법에 관한 연구 (A Study on the Non-Destructive Investigation Method of Tile Defect in the Bathroom)

  • 정기태;김범수;이정훈;송제영;오상근
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2017년도 추계 학술논문 발표대회
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    • pp.209-210
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    • 2017
  • Recently, bathroom tile defects in households are occurring more frequently. Until now, the destructive investigation method has been required to analyze tile defects. This study proposes a non-destructive using a thermal emission camera imaging as a possibly more precise method of investigating tile failure compared to previous existing methods.

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Fabrication of high-performance carbon nanotube field emitter using Thermal Chemical Vapor Deposition

  • Yu, Wan-Jun;Cho, You-suk;Park, Gyuseok;Kim, D.J.
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2003년도 춘계학술발표강연 및 논문개요집
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    • pp.43-43
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    • 2003
  • Carbon nanotubes(CNTs) have many application points, which are field emission devices, composites, hydrogen storage, nanodevices, supercapacitor and secondary battery. The most promising application point is emitter tip mays of field emission devices. Furthermore, it may be also useful as a vacuum device for high frequency and high power. But, there are some obstacles to fabricate carbon nanotube field emission device. One is that CNTs grown by CVD method has weak adhesion with substrate and the other is non-uniform length of them. These problems are very crucial in aging property and reliability of device in the field emission.

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열교환기 관사이의 거리변화에 대한 열효율 특성 (Characteristics of Thermal Efficiency with Changing Distances Between Tubes for Heat Exchanger)

  • 김종민;이재박;이승로;이창언;금성민
    • 에너지공학
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    • 제19권3호
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    • pp.177-181
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    • 2010
  • 열교환기는 용도에 따라 여러가지 형태가 존재하지만 중요한 것은 열교환기의 성능을 향상시킴으로서 열교환기의 크기를 소형화하는 것이라 할 수 있다. 그러나 보일러처럼 열교환기가 버너 앞에 위치할 경우 열교환기의 효율도 중요하지만 환경오염물질의 배출특성도 고려되어야 한다. 따라서 본 연구에서는 비예혼합화염보다 화염길이가 짧고 당량비 조절을 통해 $NO_x$ 및 CO 배출을 제어할 수 있는 예혼합방식의 버너 앞에 원형관 열교환기를 설치한 후 열교환기 관사이의 거리 및 당량비를 변화시킬 때 $NO_x$와 CO의 배출특성과 열교환기의 열효율을 실험적으로 구하였다.

DC 저온플라즈마를 이용한 디젤엔진 유해 배기가스 저감에 관한 실험적 연구 (The Experimental Study on the Removal of Diesel Engine Pollutant Emissions Using DC Non-Thermal-Plasma(NTP))

  • 채재우;황재원;정지용;한정희;황화자;김석
    • 한국자동차공학회논문집
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    • 제9권2호
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    • pp.35-42
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    • 2001
  • The diesel engine exhaust gas is know as one of the causes to produce photochemical smog, which causes damage on environmental. However, due to the high thermal efficiency and low carbon dioxide emission, the usage of a diesel engine is prevailed. In this study, the DC non-thermal plasma technology used to the particulate matter (PM) aftertreatment. The exhaust gas characteristics and energy density were investigated on the dynamometer test bed and chassis dynamometer with CVS-75 mode in a passenger diesel car. It was reported that the smoke removal efficiency has around the 70% in the dynamometer test with 80W energy consumption and the PM removal efficiency has the 68% in the real car test. The NOx also reduced the 20% according to electrode type respectively. Considering these results, plasma technology is one of the ways to simultaneously removing method the particulate matter (PM) and NOx.

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SPATE에 의한 직교이방성체의 응력확대계수 측정 (Measurement of Stress Intensity Factor of Orthotropic Material Using SPATE)

  • 황재석;서재국;이효재;남정환
    • 대한기계학회논문집A
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    • 제20권10호
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    • pp.3224-3233
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    • 1996
  • SPATE(Stress Pattern Analysis by Thermal Emission) can be effectively used to analyze the stress distribution of the orthotropic structure under the repeated load by non-contact. In this research, the measuring conception and method of stress intensity factor of orthotropic material using SPATE are suggested. The relationships between the maximum values of SPATE signal and $1/\sqrt{X'}$ (or $1/\sqrt{y'}$) are theoretically established in the vicinity of crack tip of the orthotropic material. It is certified through SPATE experiment that their linear quality is very excellent.

Dust Radiative Transfer Model of Spectral Energy Distributions in Clumpy, Galactic Environments

  • 선광일
    • 천문학회보
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    • 제43권2호
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    • pp.52.2-52.2
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    • 2018
  • The shape of a galaxy's spectral energy distribution ranging from ultraviolet (UV) to infrared (IR) wavelengths provides crucial information about the underlying stellar populations, metal contents, and star-formation history. Therefore, analysis of the SED is the main means through which astronomers study distant galaxies. However, interstellar dust absorbs and scatters UV and optical light, re-emitting the absorbed energy in the mid-IR and Far-IR. I present the updated 3D Monte-Carlo radaitive transfer code MoCafe to compute the radiative transfer of stellar, dust emission through a dusty medium. The code calculates the emission expected from dust not only in pure thermal equilibrium state but also in non-thermal equilibrium state. The stochastic heating of very small dust grains and/or PAHs is calculated by solving the transition probability matrix equation between different vibrational, internal energy states. The calculation of stochastic heating is computationally expensive. A pilot study of radiative transfer models of SEDs in clumpy (turbulent), galactic environments, which has been successfully used to understand the Calzetti attenuation curves in Seon & Draine (2016), is also presented.

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